Number 1/2012

PAIRING FOR ELLIPTIC CURVES WITH EMBEDDING DEGREE 1 DEFINED OVER PRIME ORDER FIELDS

Bogdan TUDOR

Abstract: In the last years, prime order pairing-based cryptography has received much attention. The embedding degree 1 is very appealing because the computations can be performed without any extension fields, but the efficiency parameter and this particular value of the embedding degree imposes some limits about the possible curves. This paper presents an analysis of the existing algorithms for constructing such curves and how they are related to the concept of pairing friendly. The original contribution of this paper consists in the proposal of two new algorithms. Their results are analyzed from the efficiency and computational point of view. In addition, it is presented the results of pairing implementation in Java language for the curves generated with the successful algorithm.

Keywords: : computer software, polynomial methods, data privacy, algorithms, elliptic curves

WAVE ITERATIVE PROCESS STUDY OF DOUBLE DIPOLE SCATTERING

Nicolae LUCANU Irinel Valentin PLETEA Ion BOGDAN Henri BAUDRAND

Abstract: The paper presents an application of the Wave Iterative Process (WIP) in the case of the study of the scattering of an electromagnetic plane wave by a system composed of two arbitrary placed metallic dipoles. The case of one dipole is studied at first, a second one being introduced into the scattering system later. Mutual influence is also taken into account, current density results are presented, and the possibilities of enlarging the number of dipoles in the scattering structure are also examined.

Keywords: Wave Concept, Iterative Process, metallic dipole, scattering

CHARACTERISATION OF SMALL CELLS NETWORKS DEPLOYMENT OPTIONS AND THEIR IMPACT UPON MACRO-CELULLAR NETWORKS

Cristian ANDRONE Tudor PALADE

Abstract: This paper investigates the effect of small cells networks deployment in a typical traditional macro-cellular mobile communications network. The main deployment options are presented and their impact is shown for the case of a typical residential environment. Through simulation and modeling the effect of small cells deployment is studied mainly at the macrocell users site, considering different options for the characteristic radio parameters and deployment density of the small cells. The results show which are the feasible implementation options for the small cells within macrocells, and give essential guidelines for operators when deciding to introduce small cells

Keywords: Small Cells, Femtocells, Interference, Open Access, Closed Access, Coverage

ILLUSTRATION OF AUTOMATIC DIGITAL SYNTHESIS FOR CAMELLIA-128 CIPHER ALGORITHM

Paul FARAGÓ, Thomas JACKUM, Christoph BÖHM, Maximilian HOFER

Abstract: Advances in the integrated circuit (IC) industry have enabled the integration of millions of transistors on a single chip. In these circumstances the task of the circuit designer is ever more demanding. Recent trends in CAD tools target the complete automation of the digital design flow. This article illustrates the automatic synthesis of a digital system which implements a cipher algorithm. The Camellia-128 cipher was chosen for implementation due to its potential performance in terms of IC area, processing speed and power consumption. The digital IC is automatically synthesized up to layout level with no human intervention.

Keywords: digital design automation, CAD, cipher, Camellia

HUMAN VISUAL PERCEPTION CONCEPTS AS MECHANISMS FOR SALIENCY DETECTION

Oana Loredana BUZATU

Abstract: : Predicting human eye fixations is a difficult task that usually involves complex knowledge about the human visual perception pathways. This paper proposes a method to detect salient locations using a psycho visual space based on color perception, perceptual decomposition of visual information in multiple processing channels and contrast sensitivity as basic concepts. Using a linear support vector machine to train a saliency detector directly from human eye fixation data, salient locations were predicted as a linear combination of features. Testing results have proved that the proposed method performs better than other state-of-the-art methods with certain common concepts.

Keywords: visual attention, saliency, color opponency, steerable pyramids, contrast sensitivity, support vector machine

INTEGRATION OF NETWORK CODING TECHNIQUES IN FUTURE INTERNET ARCHITECTURES

Zsuzsanna Ilona KISS, Zsolt Alfred POLGAR, Gavril Ionel MEDAN, Mircea GIURGIU

Abstract: The paper introduces several new methods and experimental results on the integration of Network Coding techniques into the architectures proposed for the future Internet. Also, there are shortly presented some of the main research initiatives proposing the design of future Internet architectures and the concepts developed. Particularly, the paper analyzes how Network Coding can be integrated into service centric and role based architectures and proposes a solution for integration of XOR based coding into the Generic Path framework. It is shown that the coded transmissions are not always beneficial and therefore adaptive activation of Network Coding is required according to the communication context and network parameters

Keywords: Future Internet, Generic Path framework, integration, network architecture, Network Coding

INVESTIGATING METHODS TO SIMULATE AND EVALUATE SIGNAL DISTRIBUTION IN ANALOG AND DIGITAL TV CABLE NETWORKS

Radu ARSINTE, Alexandru Florin ANTONE

Abstract: The paper contains a theoretical and experimental study of transmission in analog and digital TV cable networks. The first part presents an overview of the most important concepts used in modeling of the most important components from cable network, and establish the models used in this specific research. The study is proposing in the first part to simulate, using Matlab models a TV cable network. This model is compared with different approaches, like electrical model simulation using Microcap environment. Finally, in experimental results section, the results of simulations are presented and compared with the evaluations realized by previous methods of simulation. The final goal of the research will be to validate, through cross-checking, the models written in Matlab (for theoretical study of DVB-C propagation in local -home – network) or practical purposes (CATV based data network design).

Keywords: CATV network, Matlab simulation, Microcap , Headend

IMPROVED SPATIAL SCALABILITY FOR VIDEO COMPRESSION

Vipan KAKKAR

Abstract: Spatial scalability (layering) in MPEG is not often used due to the lack of coding efficiency and available ICs. This work presents an alternative spatial scalability schemes that have better coding efficiency, and yet are relatively easy to implement with existing building blocks. Furthermore it presents experiments that have been conducted in order to improve the coding efficiency, and enable a backwards compatible HDTV DVD system. Attempts have been made to improve the spatial scalability of MPEG-2/MPEG-4.

Keywords: Video Compression, MPEG, Motion Estimation, Spatial Scalability

LOW-COST PROTOTYPE EQUIPMENT FOR VLF RADIO WAVE MONITORING

Paul DOLEA, Vlad DASCAL, Tudor PALADE, Octavian CRISTEA

Abstract: The paper presents a short overview of the natural phenomena that generates VLF, ELF and SLF electromagnetic waves. In order to emphasize the importance of studying these waves, the paper presents a prototype equipment used for receiving and monitoring very low frequency electromagnetic waves generated by natural and artificial sources. The functionality of the equipment is proved by monitoring, during several days, different VLF radio transmitters located at distances over 1000 km from the reception point. The data collected revealed the diurnal variations of the VLF radio wave propagation and the induced disturbances in propagation conditions during January 4th 2011 partial solar eclipse.

Keywords: radio wave propagation, ionosphere, VLF, low noise amplifier

Number 4/2011

AN OVERVIEW OF TODAY’S MULTIPATH ROUTING

Georgeta BOANEA Melinda BARABAS Virgil DOBROTA

Abstract: The increased number of applications with strict demands regarding throughput and delay (e.g. video streaming, VoIP, video conferencing) determines the need for more efficient routing procedures in the Internet. Multipath routing is one solution that can assure a more reliable and robust transmission. This approach provides flexible load balancing and congestion avoidance by offering multiple alternative paths to a destination. This paper presents an overview of the design details of today’s multipath routing solutions, with their advantages and disadvantages.

Keywords: fast rerouting, load balancing, multipath routing, path diversity, split granularity

RESOLUTION IMPROVEMENT OF ULTRASOUND IMAGES USING DECONVOLUTION AND SUPER-RESOLUTION ALGORITHMS

Liviu-Teodor CHIRA

Abstract: Ultrasound imaging is a wide spread technique used to view body soft tissues, like tendons, muscle or internal organs for possible problems. These images are achieved by capturing the returned acoustic waves using an ultrasonic transducer. Due to the propagation in imperfect environment, the resolution of these images has a poor quality. This is caused by different problems like waves refraction, attenuations in tissues, destructive waves, bad contacts, and so on. This paper intends to achieve a preliminary synthesis of the most important directions of study for the resolution improvement. We present two important methods for ultrasound image processing: deconvolution based and super-resolution algorithms. Some simulation results are also delivered.

Keywords: ultrasound, medical image, super-resolution, deconvolution, digital image processing.

FPGA IMPLEMENTATION OF LMS AND NLMS ADAPTIVE FILTERS FOR ACOUSTIC ECHO CANCELLATION

Ioana HOMANA, Irina MURESAN, Marina TOPA, Cristian CONTAN

Abstract: The paper proposes a register transfer level (RTL) description of two well-known adaptive algorithms used in acoustic echo cancellation: the Least Mean Square (LMS) and Normalized Least Mean Square (NLMS). The RTL descriptions of both algorithms are based on their finite state machine (FSM) diagrams and were created in the popular VHDL language. ModelSim simulation results altogether whit plots obtained in Matlab prove the good behavior. As it was expected, the performance of the NLMS algorithm is superior, compared to the LMS algorithm, in term of Mean Square Error (MSE).

Keywords: VHDL description, adaptive filters, LMS algorithm, NLMS algorithm

FINGERPRINT IMAGE ENHANCEMENT USING WAVELET TRANSFORM AND GABOR FILTERING

Vipan KAKKAR, Abhishek SHARMA, T.K. MANGALAM, Pallavi KAR

Abstract: Automatic Fingerprint Identification System (AFIS) have become the most widely and popular technology in rapidly growing bio-identification applications. Fingerprint identification consists of various stages viz. image acquisition, enhancement, feature extraction and matching. The performance of a fingerprint recognition system highly relies on the quality of the fingerprint images. The enhancement is an essential step required to improve the quality of the fingerprint image. In this paper, we propose a enhancement method based on gabor filtering in wavelet domain. Gabor filter is so chosen because it has both frequency-selective and orientation-selective properties and has optimal resolution in both spatial and frequency domain. Filtering is done on the images results from wavelet decomposition and finally, the image is reconstructed to get the enhanced image. Experiments are conducted on 500dpi resolution fingerprint images commercially available from FVC2002 fingerprint database

Keywords: Fingerprint Identification, Image Enhancement, Gabor Filter, Wavelet Transform

STUDY OF EFFECTS OF THE SHORT TIME FOURIER TRANSFORM CONFIGURATION ON EEG SPECTRAL ESTIMATES

Nicolae Cristian PAMPU

Abstract: EEG signals recorded from scalp contain useful information about the activity of a large number of neurons. Signal processing is needed to extract this information from the EEG signal. Here we study the effects of configurations of Short Time Fourier Transform (STFT) to determine how the parameters of STFT affect spectral estimations of the mean and relative power in beta and gamma frequency bands of the EEG signal. A statistic analysis was performed showing the effects of several window types and window lengths. The estimation of power in a specific frequency band is affected by the configuration of the STFT.

Keywords: Electroencephalogram (EEG), Short Time Fourier Transform (STFT), EEG signal processing

STUDY OF THE DECODING COMPLEXITY FOR RATELESS ERASURE CODES

Anghel BOTOŞ, Vasile BOTA, Aurel VLAICU

Abstract: Over the Internet, bit errors within the data packets translate into packet losses at the higher layers of the OSI model, yielding a packet erasure channel. Modern erasure correcting codes promise to offer a very simple and efficient solution to data transfers over these channels, opening up also other interesting applications. Amongst them one can enumerate reliable large scale content distribution, high quality real-time data transfers, distributed storage and others. These considerations make the study of such codes an actual and interesting topic. Most of the analyses presented in literature focus on the evaluation of the performances ensured by these codes. This paper presents an evaluation of the decoding complexity of some rateless erasure codes, which is another relevant issue that affects the applicability of these codes. The complexities of several decoding methods are evaluated using several metrics which reflect different operations performed during the decoding. All results used in the evaluation are based on simulations

Keywords: rateless erasure codes, computational complexity

ASPECTS OF A LOW-COST GROUND STATION DEVELOPMENT FOR GENSO NETWORK

Vlad DASCAL, Paul DOLEA, Tudor PALADE, Octavian CRISTEA

Abstract: This paper presents the development and setup of a GENSO ground station at the Technical University of Cluj-Napoca. The ground station will be capable of automatic tracking of selected LEO satellites by using steerable high gain antennas. The ground station will be equipped with a full-duplex VHF/UHF transceiver with SSB, CW and FM modulation capabilities and with a TNC AX.25 protocol compatible, that offers data rates of 9600 bps FSK and 1200 bps AFSK for digital satellite communication. The architecture is based on the design heritage of the ground station built in support of the future Romanian Goliat mission. Tests were completed with good results and demonstrate the technical feasibility of the platform based on link budget calculations. The ground station will represent the Romanian contribution into the worldwide GENSO network and it will also act as a test-bed for the GEOID/HumSAT system.

Keywords: Nanosatellite, Low Earth Orbit, GENSO network, ground station, Cubesat

A MODEL OF A DIPOLE ANTENNA IN A 3-D FDTD SPACE

Ioana SĂRĂCUŢ, Victor POPESCU

Abstract: In this paper a dipole antenna with a gap is modeled in a 3-D Finite–Difference Time-Domain coordinate space surrounded by Perfectly Matched Layer (PML). Unlike the analytical study, where the sinusoidal distribution of the current is imposed, here the propagation of direct and reflected waves of current and potential was modeled, so distribution along the antenna resulted from simulations. The simulation results include the radiation pattern, the transitory state of the field and the effect of the conductor losses

Keywords: dipole antenna, Finite-Difference Time-Domain, Perfectly Matched Layer, Matlab model

DEFECT DETECTION AND RESTORATION OF CULTURAL HERITAGE IMAGES

Mihaela CISLARIU, Mihaela GORDAN, Aurel VLAICU, Camelia FLOREA, Silvia CIUNGU SUTEU

Abstract: One of the major problems of the old artworks is their degradation due to aging. As a result, the digitized artworks images exhibit a series of defects. Whereas scientific methods were applied to the analysis and restoration of the priceless artworks for many decades, over recent years there has been an encouragement for the development of virtual artworks restoration tools, many of them using image processing techniques. In this paper we present a series of tools for defect detection and virtual restoration of digitized artwork images, and illustrate their application of digitized wood paintings. These tools are integrated in user-friendly semi-automatic software applications. The novel algorithms proposed and integrated in our virtual artwork restoration application include: a machine learning based small defect detection, combined with the vector median filter for the small defects removal; a fuzzy image inpainting method for large defect removal (assuming the defect area was manually selected). The results achieved with the proposed software application are presented, for some wood painted icons, showing the good performance of the proposed solution and its suitability for virtual restoration of some digitized artworks

Keywords: defect detection, SVM, RGB color space

THE IMPLEMENTATION OF SCHROEDER REVERBERATOR ON AN FPGA PLATFORM USING XILINX SYSTEM GENERATOR

Corina BOTA, Botond Sandor KIREI, Albert FAZAKAS, Marina TOPA

Abstract: The paper presents a Simulink model based FPGA implementation method of the Schroeder reverberator. The Simulink model was created with a Xilinx System Generator toolbox, which aids digital circuit synthesis for FPGA platforms. The artificial reverberator can be configured to simulate the acoustics of different enclosures (ordinary room or concert hall), while device utilization on the target FPGA is low and less than 3% of a XC5VLX110T FPGA device slices are occupied by the designed system. The reverberator can model up to 2s reverberation time, which is a typical value of a concert hall

Keywords: reverberations, audio signal processing, real-time processing, FPGA, Schroeder reverberator

Number 3/2011

FEASIBILITY OF ULTRA LOW ENERGY DEVICES AND APPLICATIONS

Vipan KAKKAR

Abstract: In this paper the results of an extensive literature study on Ultra-Low-Power (ULP) electronics is presented. It discusses an emerging application area, which is characterised by very strong power requirements, called ULP electronics. It aims to evaluate possible applications to derive the requirements that emerging trend in circuits must meet and to recognise as far as possible the challenges, which have to be faced. At first few selected applications which would at most benefit from an ULP design approach, are presented as example. Finally few examples of realized circuits in the market as well as in the literature are given.

Keywords: Ultra-low-power electronics, low-power electronics, biomedical electronics, wireless sensor network

DISTRIBUTED BENDING MEASUREMENT SENSOR

Ramona V. GALATUS, Lorant SZOLGA, Emil VOICULESCU

Abstract: The paper introduces an improved bendable distributed optical fiber used into an all-optical power-up system. The contribution highlights the high sensibility of the large mode area (LMA) fiber, designed with the most powerful higher-order mode rejection. The considered LMA were used in conjunction with MOFA power-up configuration scheme. Setup has a master oscillator fiber amplifier (MOFA) configuration for large scaling of the output power, meant for a linear sensing accuracy of the order of microns. A power variation of the fundamental mode was measured in order to discern the proportional rate for bending radius. The signal was 1550nm, typical to assure compatibility with telecommunication links. The performance is optimized by varying the bending radius, index/ doping profile, the LMA fiber custom profile and core diameter

Keywords: Fiber Optic Sensor, Bending Measurement, EDFA(Erbium Doped Fiber Amplifier), LMA, Highly Doped Fiber, MOFA

GENETIC ALGORITHM FOR TRANSITIONS SCHEDULING GUIDANCE OF TRAINS

Maria-Magdalena SANTA Octavian CUIBUS Tiberiu LETIA

Abstract: The railway traffic system is characterized as large and dynamic with uncertain properties related to resource loading, train arrivals and failures. The purpose of this paper is to control system online in order to guarantee that all the trains behave according to their timelines. The solutions are found with distributed expert systems. The control signals are implemented and verified using temporal Rule Nets. Due to the large number of variants involved, extensive check of all possible durations and waiting times on a resource is impossible, therefore an evolutionary approach (genetic algorithm) must be used. The results obtained through simulations show that the proposed distributed controllers solve the control problems and can be used for large scale implementation.

Keywords: distributed expert systems, genetic algorithm, temporal rule nets and railway applications

3D RECONSTRUCTION AND VOLUME COMPUTING IN MEDICAL IMAGING

Ligia-Domnica CHIOREAN, Teodora SZASZ, Mircea-Florin VAIDA, Alin VOINA

Abstract: Medical imaging domain is a field of interest which concentrates great efforts to offer software tools for the assisted diagnosis. Segmentation, 3D reconstruction and visualization are techniques that allow physicians to observe possible pathological structure inside of the human body. Computing the volume of such a structure offers critical information in the evaluation of the disease gravity. In this paper we present a method for 3D reconstruction of the pathological zone and propose a method for volume computing. We consider this as a start for developing a complex software tool for Deep Brain Stimulation procedure in the neurosurgery domain.

Keywords: volume/ surface rendering, multi-planar reformatting, DICOM files, segmentation

DIGITAL TECHNOLOGY IMPLEMENTATION OF PEAK CURRENT CONTROL METHOD WITH PID COMPENSATOR APPLIED TO BUCK CONVERTER

Octavian BOTEZ Mihai LUCANU Ovidiu URSARU Cristian AGHION

Abstract: Lately, digital control technology has advanced greatly in the field of power electronics[14], enabling implementation of more and more common method to control electronic converters. This paper presents the modeling and the simulation of peak current control method with PID compensator, applied to a synchronous buck converter with digital control, and its practical implementation. For simulation, the C language source code was designed for the perturbations compensating function, the duty cycle calculation applied to PWM generator, and variable current reference.

Keywords: : peak current, PID compensator, synchronous buck, digital technology

SIMULATION OF STOCHASTIC PROCESSES IN FINANCIAL MODELING

Mircea Cristian GHERMAN, Monica BORDA

Abstract: This paper discusses theoretical properties, shows the performance and presents some extensions of techniques used for simulation of stochastic differential equation applied on the financial data modeling. There are realized comparisons of different approaches for discretization schemes and their performances from the simulation convergence point of view. This study shows that, depending on the applicability of stochastic modeling to various financial data, the evolution of asset price over the time can be characterized by different processes accordingly with their dynamics.

Keywords: stochastic differential equations, simulations schemes, jump diffusion, convergence schemes

GENDER AND AGE ESTIMATION BASED ON FACIAL IMAGES

Hlaing Htake Khaung TIN

Abstract: In this paper, a fast and efficient gender and age estimation system based on facial images is developed. There are many methods have been proposed in the literature for the age estimation and gender classification. However, all of them have still disadvantage such as not complete reflection about face structure, face texture. This technique applies to both face alignment and recognition and significantly improves three aspects. First, we introduce shape description for face model. Second, the feature extraction phase, two geometric features are evaluated as the ratios of the distances between eyes, noses, and mouths. Finally, we classified the gender and age based on the association of two methods: geometric feature based method and Principal Component Analysis (PCA) method for improving the efficiency of facial feature extraction stage. The face database contains the 13 individual groups. Within a given database, all weight vectors of the persons within the same age group are averaged together. A range of an age estimation result is 15 to 70 years old, and divided into 13 classes with 5 years old range. Experimental results show that better gender classification and age estimation

Keywords: gender classification, age estimation, principal component analysis, face recognition, feature extraction

Number 2/2011

SPECTROGRAM BASED MUSICAL INSTRUMENT IDENTIFICATION USING HIDDEN MARKOV MODEL (HMM) FOR POLYPHONIC SOUND SIGNALS

Daulappa G. BHALKE, C. B. RAMA RAO, D. S. BORMANE, Manisha VIBHUTE

Abstract: Spectrogram is generated from the instrumental music, which is used to calculate the spectral, temporal & modulation features. To detect musical instruments from polyphonic music, 23 features are selected. The feature vector is generated using 12 specific features. Hidden Markov model (HMM) is used to calculate the conditional instrument existence probability. In this work, ten musical instruments from wind and string categories are used for identification. The musical instrument is recognized using HMM algorithms: Forward, Backward, Posterior decoding & Viterbi algorithm. Identification result is 91% for monophonic & 87% for polyphonic musical notes.

Keywords: Spectrogram, Feature vector, HMM, Musical Instrument Identification result

SHARING THE KNOWLEDGE: SEMANTIC MEDIAWIKI

Cornelia Flavia M. VEJA, Mircea – Florin VAIDA, Gregor HAGEDORN

Abstract: The information with the purpose of documentation, media sharing, learning, and entertainment accumulated in wikis is huge. The main problem in wikis is that the information is produced from humans to humans, not for machines. Wiki’s information is a semi-closed world and the use and re-use of wiki’s information by external non-humans agents are cumbersome tasks. Stepping further, to unstructured data but strongly connected information to structured data and annotated information is brought by adopting Semantic technologies into wikis. This paper presents a survey art and comparative study of Semantic Wikis, with the emphasis on Semantic Media Wiki model

Keywords: MediaWiki, Semantic MediaWiki, Semantic Web, Semantic wiki, Social Software, Semantic Social Software, wiki system.

REMOTE MONITORING OF THE INTELLIGENT BUILDINGS PARAMETERS

Nicolae MURESAN, Bogdan ORZA, Aurel VLAICU

Abstract: Remote monitoring of the parameters of a building requires reading/writing the values of the variables provided by networks of smart devices (sensors, actuators and controllers), that control these parameters. A solution may be the creation and optimization of a web interface that can be accessed from the Internet via a web server, providing IP connectivity and other web capabilities. Networks can also be monitored through the 220V AC network by using transceivers. Various services required in buildings can be remotely monitored, the energy management can be improved by making a more efficient use of the electricity and of the heat consumption with the aim of reducing the maintenance cost. Utilities companies (water, gas, electricity, etc.) are also becoming more interested in remote monitoring of customers' consumption and are trying to integrate some of the so called "advanced metering systems” (which contain smart meters networks). Remote monitoring of utilities, as well as monitoring building parameters, requires read/write of the network variables values of smart meters that operate with customer utility values [15], [16], [26]. Our paper presents the principles of remotely monitoring the parameters of the buildings, together with the most commonly used norms in the field and also an example of an application for remote monitoring several LonWork control networks.

Keywords: LonWorks, RNI, Router IP-852, IP Training Center, drawing LonMaker, server i.LON, X-10, PLC

HARDWARE IMPLEMENTATION OF DIVERSITY SCHEME FOR MIMO COMMUNICATION

Angela DARIE, Ion BOGDAN

Abstract: Because of the tremendous growth of wireless communication and the demand for faster communication, new applications have developed such as broadband wireless Internet access. To cope this demand for increased capacity, multiple antennas can be used for improving the performance of wireless communication systems. The aim of this paper is to implement a simple multi-antenna scheme, a 2x1 Alamouti code, on a Xilinx FPGA connected via UART to an Iris mote. Our focus is to make a practical testing for MIMO system within indoor environment using external peripherals of Iris mote and communication protocols. To accomplish this, the Iris platform has to be configured to run over I2C to the class Spartan 3E board, and the Spartan’s UART port is utilized to issue Iris radio communication stack.

Keywords: FPGA, MIMO, Iris mote, radio communication.

AN ADAPTIVE DIGITAL COMPENSATION DESIGN FOR BUCK CONVERTER TOPOLOGY

Radu ETZ, Dorin PETREUS

Abstract: This paper presents a digital type III compensator that needs no calculation made by a designer. First an analog type III compensator is designed for a buck converter and based on it the digital model is obtained. Both the analog and digital approaches are simulated in PSIM and the digital compensator is written in a Microchip dsPIC for experimental results. The dynamic response of these controllers under input voltage change and load current variations are presented.

Keywords: digital control, buck converter, type III analog compensator, type III digital compensator

ACTIVITY RECOGNITION FROM ACCELERATION DATA COLLECTED WITH A TRI-AXIAL ACCELEROMETER

Ioana FARKAS, Elena DORAN

Abstract: This paper developed a high accuracy for human activity from data collected with a single tri-axial accelerometer mounted on the right part of the hip. The accuracy of this detection is very important for classifying the postures and because of this we use acceleration magnitude and neural network method for detection and compare them to find the best solution.

Keywords: Tri-axial accelerometer, activity recognition, acceleration magnitude, neural networks

FPGA IMPLEMENTATION OF AN ACOUSTIC ECHO CANCELLER

Ioana HOMANA, Irina MURESAN, Marina TOPA, Cristian CONTAN

Abstract: Acoustic echo cancellation (AEC) is an occurrence in today communication systems. The interferences caused by acoustic echo are distracting the users and reduce the quality of the voice. In order to attenuate the effects created by the echo, a Least Mean Square algorithm is used. In this paper, we present the implementation of an LMS adaptive filter, designed on a Xilinx Virtex-5 FPGA and implemented using VHDL. ModelSIM simulation results altogether with plots obtained in Matlab prove the behavior of the chosen adaptation algorithm for the specific application.

Keywords: acoustic echo cancellation, LMS, FPGA

NONLINEAR ACOUSTIC SYSTEM IDENTIFICATION USING ADAPTIVE COMBINATIONS OF VOLTERRA FILTERS

Cristian CONTAN, Marina TOPA, Ioana HOMANA, Irina MURESAN

Abstract: The paper proposes two nonlinear system identification methods in order to reduce the compromise between convergence speed and steady-state that occurs when using third order adaptive Volterra filters. Combination of filters and combination of kernels schemes are outlined. Adaptation of the kernels is achieved using a Normalized Least Mean Square algorithm. The tradeoff between speed and stability is emphasized by selecting different step-size parameters for each kernel. Both nonlinear approaches are applied in acoustic Loudspeaker-Enclosure-Microphone setups where several sources of nonlinearities exist: the overdriven amplifier’s or small loudspeakers’ operated at high volume. A third order polynomial with distinct Linear-to-Nonlinear Ratios is chosen to model these distortions. The evaluation is made in terms of Echo Return Loss Enhancement in experiments conducted for various input signals. Results show that the overall adaptive combinations perform each time better or at least as well as the best component filter

Keywords: Nonlinear system identification, Volterra filters, adaptive combination, adaptive algorithms

A FUZZY SET GENERALIZATION OF THE EXEMPLAR-BASED IMAGE INPAINTING

Mihaela CISLARIU, Mihaela GORDAN, Aurel VLAICU

Abstract: Inpainting is a technique of modifying an image in an undetectable way, by removing large objects or damaged areas and replacing them with plausible background. In this paper we have approached the exemplar-based image inpainting method proposed by Criminisi. This method uses patches from the image to fill the damaged region. Here we propose a new fuzzy set generalization of the exemplar-based image inpainting by using a fuzzy window. We use the fuzzy window to try to improve the finding of the most similar patch for filling. Experimental results show that the proposed method yields improvements compared to other methods

Keywords: Image restoration, inpainting, fuzzy logic, RGB color space

Number 1/2011

Finger Detection in Video Sequences Using a New Sparse Representation

Vasile GUI, Gheorghe POPA, Pekka NISULA, Veijo KORHONEN

Abstract: In this paper we propose a new method for finger detection in video sequences. The method is robust and has a low computational cost. From a background subtracted image, we generate a sparse image representation, based on line strip features. We use a robust and adaptive clustering method, related to the mean shift (MS) to detect fingers and extract finger pose parameters from validated clusters. We applied the proposed method in a HCI designed to control very large public displays.

Keywords: Mean shift, sparse, robust estimation, finger detection, tracking, HCI

Programmable Control System with Applications in Direct Current Motors Control

Andrei COZMA, Dan PITICA

Abstract: This paper presents a programmable control system with applications in Direct Current (DC) motors speed control. The system consists of a signal acquisition module, a programmable high speed Digital Signal Processor (DSP), a Microcontroller Unit (MCU), an output module and a communication module. A speed and position sensor integrated in the data acquisition module provides through an I2C bus data related to the motor’s shaft speed, position and rotation direction. The DSP can perform basic arithmetic operations, finite and infinite impulse response filtering and fuzzy logic operations at high speed and with a high degree of parallelism on the data received from the signal acquisition module. The MCU is a soft processor core with a RISC instruction set and it is used for controlling the operation of all the other modules and for implementing more complicated control algorithms that cannot be performed by the DSP. The output module contains a Pulse Width Modulated (PWM) block for generating the DC motor’s control signal. The communication module transfers data to/from a PC through a USB connection. By integrating all the above mentioned modules into one single chip a complete real time control core is provided.

Keywords: automatic control, direct current motor, digital signal controller

A survey of Augmented Reality in Health Care

Marius DANCIU, Mihaela GORDAN, Aurel VLAICU, Alexandru ANTONE

Abstract: Although Augmented Reality technology was first developed over forty years ago, there are no recent studies that give an overview of the research in the field of medicine. This paper surveys the state of the art in applications of virtual environments and related technologies in the Health Care domain. Virtual Reality (VR) and Augmented Reality (AR) have the potential to assist us in fields as education, maintenance, design and reconnaissance to name only a few, but also in Health Care, improving surgical interventions and image-guided therapy by providing clinicians with interactive three-dimensional visualizations in all stages of treatment. Tools that respond to the needs of the present virtual environments systems are continuously refined and developed. Applications of these technologies improved the quality of Health Care and as we move forward into the second decade of VR, we may see more and more adopters of this technology as the cost came down. It also discuss the remaining challenges that need to be further studied and solved in order to make these systems attractive and efficient. This survey provides a starting point for anyone who work in researching or use Augmented Reality.

Keywords: Augmented reality, virtual reality, human-machine interaction, segmentation, development suite.

COMPLEX MODEL OF A SERIES LOAD INDUCTION HEATING INVERTER

T. SZELITZKY, I. INOAN, M. TULBURE, A. O. NEAGA

Abstract: The design of robust controllers require a special type of system model, called augmented plant (system) model, which includes as uncertainties the plant parameter variations. In this article accuracy of the classic describing function based model will be analyzed and updated to include the parameter uncertainties. Additive and multiplicative type parameter uncertainties will be introduced and analyzed the effect over the system model.

Keywords: Robust control, Induction heating, series load inverter

DOUBLY ITERATIVE DECODING OF SPACE-TIME TURBO CODES USING LOG-APP ALGORITHM

Ana-Mirela ROTOPANESCU, Lucian TRIFINA

Abstract: In this paper are examined the performances of a low complexity doubly iterative decoder for space-time turbo codes on a quasi-static fading channel, using a Log-APP (logarithmic a posteriori probability) compared to a Max-Log-APP (maximum Log-APP) algorithm decoding algorithm for turbo codes. The decoder uses preliminary soft values of the coded symbols, obtained after a limited number of turbo iterations, in order to reduce the spatial interference of the received signal. In the coding scheme, the core of the iterative decoding structure is a soft-input soft-output APP module. The obtained frame error rate (FER) and bit error rate (BER) performances are compared to those achieved by applying a simple scaling coefficient to the extrinsic information, when a Max-Log-APP algorithm is used.

Keywords: space-time turbo codes, doubly iterative decoder, Log-APP algorithm, Max-Log-APP algorithm, BER/FER performances

SUB-1V BANDGAP VOLTAGE REFERENCE OPTIMIZATION WITH GENETIC ALGORITHMS

Paul FARAGO, Lelia FESTILA

Abstract: This paper proposes an evolutionary approach to Bandgap Voltage Reference (BVR) design. The efficiency and feasibility of this method for solving the circuit design task are investigated. For demonstration purpose, two sub-1V BVR circuits are chosen. Circuit optimization is performed for various algorithm options. We have compared the design results obtained for purely random and deterministic initial conditions.

Keywords: Sub-1V bandgap voltage reference, evolutionary circuit design, genetic algorithm (GA), GA parameters

EFFICIENT STRATEGIES TO OPTIMIZE A POWER DISTRIBUTION NETWORK

Raul FIZESAN, Dan PITICA

Abstract: One of the biggest design challenges for today is to properly design, manufacture, simulate and validate a power distribution network (PDN) in systems with increasing speed, power dissipation and density. Power distribution networks are typically comprised of capacitors networks that have several types of capacitors and values to obtain target impedance over the required frequency range for the power/ground planes on PCBs. Capacitors provide a temporary source of localized energy for instantaneous current demands from an IC, and a low-impedance return path for high frequency noise.

Keywords: Power distribution network, target impedance, decoupling capacitor, dielectric constant, plane separation

Inertial Indoor Navigation System

Lucian Ioan IOZAN, Jussi COLLIN, Jarmo TAKALA, Corneliu RUSU

Abstract: This paper represents a first step in developing an indoor navigation system based only on Micro-Electro-Mechanical Systems (MEMS) accelerometer and gyroscope sensors. The major advantage of the proposed inertial navigation system consists on the fact that it does not require any complex infrastructure to be able to operate. For determining the distance it uses three axis accelerometer sensors, while the direction of the user is determined from the gyroscope angular rate data. As no infrastructure is used, the cost of such a system is low, but at the same time the lack of infrastructure represents its highest limitation. More exactly, for long periods of time the errors are cumulating in the navigation solution determining the deterioration of its accuracy. This limitation can be suppressed by using robust algorithms that can estimate and compensate these errors from the accelerometer and gyroscope signals.

Keywords: inertial navigation, gyroscope sensors, MEMS technology, PDR algorithm

EXPERIMENTAL MEASUREMENTS OF THE POWER CONSUMPTION FOR HARDWARE PLATFORM eZ430-RF2480

Rodica-Elena DORAN, Ioana-Iuliana FARKAS

Abstract: One of the most important characteristics that defines the fields of Wireless Sensor Networks is the focus on energy consumption. Understanding energy consumption is an essential factor for sensors networks operating on limited power reserves, since many sensors nodes are powered by batteries. Once the battery of a node has depleted the node fail making the network useless. This paper describes a series of experiments which obtained detailed measurements of the power consumption on eZ430-RF2480. The data is presented as a collection of equations for calculating the power consumption and battery lifetime in transmitting, receiving, and requesting data packets.

Keywords: sensor networks, eZ430-RF2480 platform, power consumption, periodic transmission

Number 4/2010

New pseudo-random interleaver with increased parameters

Georgian Alexandru LAZAR, Nicoleta Roxana BUZATU, Elena COJOCARIU, Lucian TRIFINA, Razvan VIERU

Abstract: This paper presents a new algorithm of obtaining a pseudo-random code-matched interleaver leading both to very good interleaver parameters and performance. The difference between the proposed permutation and other code matching techniques is that not only the distance spectrum is improved but also the parameters of the interleaver. The design procedure is described in depth, and the benchmarking is done against the High Spread-Random and the deterministic Long Term Evolution (LTE) standard interleavers.

Keywords: Interleaved coding, modulation coding, code matched, turbo codes, error correcting codes

AN EXPERIMENTAL STUDY OF QUALITY ANALYSIS METHODS IN DVB-S/S2 SYSTEMS

Alexandru-Florin ANTONE, Radu ARSINTE

Abstract: The paper is proposing a study and practical experiments of testing methods in digital television, transmitted in Digital Video Broadcasting standard. The main objective of the research presented in this paper was to establish if the testing tools designed and validated for DVB-S, are useable to evaluate DVB-S2. This is important in educational environments and small enterprises, to find new applications for the existing equipment. Testing methods follows three directions: transmitted services (data link layer), RF (Radio Frequency) interface and reception (physical layer). We pursued the following objectives: DVB-S2 model study (from Simulink Matlab), to establish the key measurement points in this evaluation, analysis of DVB-S/S2 streams, RF parameters measurements in terms of C/N (Carrier to Noise Ratio) and spectrum.

Keywords: : Digital Video Broadcasting Satellite, Test bed, Multiplex stream

SINGLE WALL NANOTUBES BEHAVIOUR IN RF FIELD

Dan PANTIS, Sorin SPINEAN, Alexandra EFIMOV, Rodica ION, Monica BORDA

Abstract: Nanomedicine represents a new discipline which combines nanoscience and nanotechnology. It opens new areas of development, like drug delivery by nanoparticles, nanotubes or fullerenes, nanostructures to be used in medical diagnostics, prevention, labeling and imaging. Our study will certificate that the temperature doesn’t have any influence above Carbon Nanotubes in our interest range (40-43º) – obtained and controlled using RF field.RF can be used in their delivery into the cell. Current radiofrequency ablation (RFA) techniques are limited by accuracy of targeting and are used for thermoablation of specific pathologies. The aim of our research was to demonstrate and to use further the fact that SWNT are ideal transporters, due to immunity at thermal variations. The biological and medical aim of the study is to evaluate this process in cancer cells. Our experiments where done into the ICECHIM Laboratory for Analysis and Testing - Laboratory testing for hazardous substances, waste and wastewater . Our results presents the mass loss correlated with degree of temperature in order to be used in the future studies as background into the cancer treatment by nanotubes delivery.

Keywords: : RF, nanotubes, cancer cell, nanobiotechnology

A MULTIMODAL AUTHENTICATION SYSTEM

Marius DAVID, Monica BORDA

Abstract: In this paper, we propose a secure fingerprint matching technique, which was combined with conventional authentication methods to achieve more secure communications. We describe in detail all the steps needed for preprocessing and fingerprint image classification. Also an algorithm based on the local structure of the minutiae is presented to match the fingerprints.

Keywords: Fingerprint, identification, authentication, normalization, filtering, binarization, skeletonization, fingerprint matching unimodal biometric system, multimodal biometric system

A CONCEPTUAL FRAMEWORK AND IMPLEMENTATION FOR DEVELOPING WS - QoS AWARE ARCHITECTURES

Cosmina IVAN, Vasile DADARLAT

Abstract: Web Services and SOA are becoming more and more popular these days and more and more businesses are planning to build their future solutions on Web Services technology. By now, SOAP and WSDL have become reliable standards in the field of Web Services execution. While the concept of UDDI allows for automatic discovery of services implementing a common public tModel interface, there have been only few attempts to find a standardized form to describe the Quality of service (QoS) with which the service is performed. Nevertheless, the QoS a provider delivers will become a decisive feature when it comes to selecting one from many availably services providing the same functionality. Today, we have sophisticated technology to actively differentiate between various QoS levels both on transport level (DiffServ, IPQoS, CoS for UMTS/ATM/RCL) and server level (load balancing, transaction differentiation, HTTP request differentiation), yet there are only few means to describe the desired QoS on application layer. To tackle this, we propose a conceptual framework based on a Xml schema to declare both clients’ QoS requirements and the QoS level service providers, and we have designed and implemented a framework for C# / .NET application developers to assign QoS requirements to a client application’s service proxy which can then be used to inquire a QoS service broker for the best QoS offer fulfilling the requirements from all offers available for services that implement the specified interface.

Keywords: Framework, QoS – Quality of Service , WS-Web Services, SOAP/WSDL/UDDI

DESIGN OF A T-SHAPED SLOT ANTENNA FOR UWB COMMUNICATIONS

Satya Kumar VANKAYALA, Saida REDDY

Abstract: This paper presents a design of T-shaped slot antenna for ultrawideband (UWB) communications. Multiple resonances are generated and unified to form a large bandwidth from 2.5 to 10.5 GHz for S11 < −10dB by constructing open ended modified T-shaped slot antenna and by extending a small section of the microstrip feed line. The simulated result shows that it has good radiation patterns and pulse handling capabilities within the band of interest.

Keywords: Ultrawideband, Microstrip feed, Group delay

NONLINEAR SYSTEM IDENTIFICATION USING ADAPTIVE VOLTERRA FILTERS FOR ECHO CANCELLING

Cristian CONTAN, Marina TOPA, Ioana HOMANA, Botond Sandor KIREI

Abstract: Adaptive nonlinear filtering plays an important role in audio signal processing and echo control. In this contribution a nonlinear system identification method is proposed. The setup is built using adaptive Volterra filters of second and third order with the same memory length. The adaptation is achieved using a Normalized Least Mean Square algorithm with a proper selected step-size parameter for convergence and stability. Functions with nonlinear characteristics are chosen to test the method. Performances are evaluated in terms of Echo Return Loss Enhancement and Mean Square Error. Results show that Volterra filters perform better than linear filters in weakly nonlinear structures.

Keywords: Adaptive algorithms, Volterra filters, nonlinear identification, error reduction

FIR SYNTHESIS OF THE HUMAN HEARING MECHANISM RESPONSE

Erwin SZOPOS, Marina TOPA, Lelia FESTILA, Horia HEDESIU

Abstract: The paper deals with the synthesis of a model for the nonlinear human hearing mechanism response. The non-uniform frequency sampling is combined with the interpolation methods to design a FIR filter to approximate the psychophysical data (audiogram). The analysis of the designed filters is achieved in LabVIEW. To evaluate the FIR synthesis the magnitude characteristic and the impulse response for different interpolation methods are compared.

Keywords: Audiogram, psychophysical, approximate FIR filter, GCD, interpolation, relative error

32x32 Parallel Analog Architecture For Image Processing Using Log Domain Active Pixel

Ion VORNICU, Liviu GORAS

Abstract: In this paper the transistor level simulation of a 32x32 analog parallel architecture of Cellular Neural Network (CNN) type able to perform spatial filtering operations is reported. The circuit level implementation is obtained by the log-domain mapping of the linear equations describing the CNN by using MOS transistors biased in weak inversion. The spatial filter is simulated in a 340nm CMOS technology. In the last part of the paper several examples of image processing operations like smoothing and edge detection using a chessboard type input image are presented.

Keywords: spatial filtering, log-domain, image processing, smoothing, edge detection

GENETIC ALGORITHMS FOR NETWORK CODING OPTIMIZATION

Zsuzsanna KISS, Zsolt POLGAR, Mircea GIURGIU

Abstract: The optimization of networks which implement Network Coding techniques is necessary for efficient resource utilization. If the data is encoded only in a subset of nodes, selected in the appropriate way, the complexity of the coding operations could be decreased, while ensuring the imposed performances. Finding the minimum number of encoding nodes is a NP-hard problem, but genetic algorithms could offer a good solution to this problem. In this paper we investigate by computer simulations the performances of a genetic algorithm adapted to the network optimization problem and we try to find the combination of parameters which ensures low optimization time.

Keywords: Network Coding, genetic algorithms, network optimization, node selection

COMMUNICATION BETWEEN INTELLIGENT DEVICES IN LONWORKS CONTROL NETWORKS

Nicolae MURESAN, Bogdan ORZA, Aurel VLAICU

Abstract. A modern control network consists of a number of intelligent devices that communicate on one or more channels, using a common protocol. The network’s intelligent devices, called nodes, may each include more microprocessors running the application, and the protocol. Also, each device includes a component called transceiver, that provide the electrical interface with the communication channel. In the LonWorks networks, most of the devices (intelligent sensors, controllers, actuators), exploit the advantages of the Neuron Chip, the default LonWorks node, which includes three processors, two of which execute the LonTalk protocol, and the third the device’s application-programme. The Neuron Chip supplies the functions of the first six OSI stack layers, the user needing to provide only the configuration and the programming of the application layer. The goal of this paper is to present the comunication mode between intelligent devices, in LonWorks networks, at the MAC and Application levels, based on LonTalk protocol. This analysis is useful in order to know the conditions to be fulfilled for an optimal design of the network, optimal setup and configuration of the devices, and to provide multivendor interoperability. The paper also presents an example of effective design of a lighting control network.

Keywords: LonWorks, LonTalk, LonMaker Basic Shape, LonMaker design, predictive p-persistent CSMA.

Number 3/2010

Speech and Signature Based Multi-Modal Biometrics Verification

Mohamed SOLTANE

Abstract—This paper describes a combined behavioral techniques based on speech and signature biometrics modalities. Fusion of multiple biometric modalities for human verification performance improvement has received considerable attention. Multi-biometric systems, which consolidate information from multiple biometric sources, are gaining popularity because they are able to overcome limitations such as non-universality, noisy sensor data, large intra-user variations and susceptibility to spoof attacks that are commonly encountered in mono modal biometric systems. Soft decision level fusion based Gaussian mixture models (GMM), in which the (EM), (GEM) and (FJ) algorithms for estimating the parameters of the mixture model and the number of mixture components have been compared. The test performance of the fusion, EER=0.0 % for "EM" and "FJ", EER=0.02 % for "GEM", show that the combined behavioral information scheme is more robust and have a discriminating power, which can be explored for identity authentication.

Keywords: Biometric authentication, behavioral biometrics, speech analysis, signature verification, soft decision fusion, Gaussian Mixture Modal, EM, GEM and FJ.

BANDGAP VOLTAGE REFERENCES BASED ON F-F-1 FUNCTIONS

Lelia FESTILA, Mihaela CIRLUGEA, Lorand SZOLGA

Abstract: We propose in this paper a bandgap voltage reference (BVR) structure based on a class of circuits belonging to ELIN design [5]. F-F^-1 amplifiers[6] were used for this purpose. They have the advantage of simplicity, a natural nonlinearity compensation and offer possibility to be current controlled or tuned so they do not need resistors as usually bandgap references do. One of the two BVR schematics resulted from the general structure is a simplified variant of a reconfigurable BVR proposed in literature [4]. The second resulted and proposed variant is a new one. Simulations proved the functionality and validity of this general structure and BVR unconventional variants.

Keywords: Bandgap voltage references, ELIN design, F-F^-1 functions

A Review of Current Strained Silicon nanoscale MOSFET Structures

Amit CHAUDHRY, Garima JOSHI, J. N. ROY, D. N. SINGH

Abstract: Improvement in performance of Si- Metal Oxide Semiconductor Field Effect Transistors (MOSFET) through scaling is very difficult due to the several physical phenomenon mainly non classical in nature at nanometer scales. In this paper, an attempt has been made to give a detailed review of strained silicon technology so far developed since its inception. Various biaxial and uniaxial strained (MOSFET) structures have been studied. The advantages, disadvantages, physics and fabrication process of these structures have also been outlined and reviewed critically. The review indicates that this technology is very much required in nanoscale MOSFETs due to its several potential benefits over the conventional bulk technology. The paper also provides the insight of how the use of various techniques such as relaxed SiGe, graded SiGe, strained silicon on insulator (SSOI), silicon germanium on insulator (SGOI) and various other hetero-structures help in providing improved performance.

Keywords: Uniaxial strain, Biaxial strain, Mobility, SiGe, strained silicon technology, strained silicon on insulator, Hetero-structures.

USING SOFTWARE DEFINED RADIO AND COGNITIVE RADIO TECHNOLOGIES IN SMART HOME ENVIRONMENTS

Levente SZALONTAI, Lelia FESTILA

Abstract: Nowadays there’s a big need for intelligent smart home environments to reach a cost effective energy management and in the same time to provide a high level of comfort and security for smart home inhabitants. In smart home environments there are many different wireless sensor, home appliance and multimedia networks working on different airinterfaces, protocols and standards that have a contribution to this cost effective energy management. The biggest problem is the lack of flexibility regarding the communication between these networks and smart home network devices control. The solution which seems to be the best one is using Software Defined Radio (SDR) and Cognitive Radio (CR) technologies which could provide higher flexibility in controlling and monitoring these networks as well as much faster implementation of new standards and protocols. We analyze in this paper the possibilities for using these two technologies in modern smart home wireless networks. Starting from predefined tasks a modern smart home should fulfill, we made a critical analysis of SDR technology’s current state of the art and finalized this analysis with conclusions regarding the possibility of using one of the best solutions to implement this technology in smart home networks.

Keywords: software defined radio, smart home, cognitive radio

On Hand Gestures Recognition Using Hidden Markov Models

Vasilica TATARU, Laurentiu Radu VIERIU, Liviu GORAS

Abstract: : In this paper several results concerning static hand gesture recognition using an algorithm based on left-right Hidden Markov Models (HMM) are presented. The features used as observables in the training as well as in the recognition phases are based either on the 2D Discrete Cosine Transform (DCT) or on the Principal Component Analysis (PCA). The left-right topology of the HMM together with the Baum-Welch algorithm for training and Viterbi algorithm for testing led to the best results. Simulation results show that the system has a recognition rate of 97.5% for DCT and 95% for PCA.

Keywords: Human-Computer Interaction, Hand Gestures Recognition, Hidden Markov Models

ITERATIVE REWARDS GENERATOR FOR MOBILE TELECOMMUNICATIONS OPERATORS

Marius Cristian URECHE, Mircea VAIDA, Alin VOINA

Abstract: Dealing with large amounts of data always was a delicate operation. Mobile telecommunications operators need high quality management systems to provide top-class services for their customers. The challenge is to assure data processing in a real-time or nearly real-time manner while facing the dynamic changes that are the heart of this field of engineering. We propose one targeted software architecture for iterative rewards generator enabling mobile telecommunications operators to grow their revenue by implementing iterative rewarding campaigns.

Keywords: mobile telecommunications, rewards generator, intelligent network platforms, reward-based loyalty campaigns

LABVIEW FPGA IMPLEMENTATION OF DIGITAL REVERBERATORS

Ioan CATUNA, Erwin SZOPOS, Marina TOPA

Abstract: : The goal of this paper is to present a way in which digital reverberation algorithms can be implemented on FPGA. Schroeder’s late reverberator was chosen to be analyzed, implemented as an online algorithm in LabVIEW FPGA and then deployed on a National Instruments CompactRIO system. The hardware implementation is tested with three different voice sequences, and its parameters are adjusted so that the reverberation effect improves the quality of the sound, without inserting distortions or unwanted noise.

Keywords: : Comb and all-pass filters, Schroeder’s reverberator, loop and reverberation times, LabVIEW FPGA

An Approach on Bimodal Biometric Systems

Eugen LUPU, Simina EMERICH

Abstract: : Although unimodal biometric systems have an edge over traditional security methods they have their limits and raise a variety

of problems. In order to overcome some inconveniencies and limitations of these systems and in order to realize reliable and robust authentication systems, the use of multimodal biometric systems is recommended. The information contained in multiple biometrics can be integrated by using various methods at distinct levels (rank, decision, match-score levels, feature and sensor) and in different contexts. A short presentation of the different fusion techniques has been made to highlight their advantages and disadvantages. The experiments were made on a bimodal biometric system employing speech and dynamic signature as biometric features. The results show that the score fusion of the two biometric improves the system overall performance.

Keywords: : biometric, bimodal, speech, dynamic-signature, score level fusion, normalization

A THREE LEVEL VOLTAGE INVERTER USED FOR AN INDUCTION MOTOR CONTROL

Nicoleta Roxana BUZATU, Dimitrie ALEXA, Georgian Alexandru LAZAR

Abstract: : Advances in power electronics technology allowed the wide investigation of multilevel converters that provide higher power with less harmonic components compared to the two - level structure. Among this family of converters, the three - level neutral – point - clamped (NPC) converter is widely used in medium voltage applications. This paper presents a 3 - level Neutral – Point - Clamped inverter using space vector pulse width modulation (SVPWM) for an induction motor control.

Keywords: : Three - level voltage inverter, neutral-point-clamped (NPC), induction motor, speed control

PERFORMANCE ANALYSIS OF ASYMMETRIC TURBO CODED MODULATION WITH TRANSMIT ANTENNA DIVERSITY

Lucian TRIFINA, Daniela TARNICERIU, Ana-Mirela ROTOPANESCU

Abstract: The performances of turbo coded modulation using asymmetric turbo codes with transmit antenna diversity are analyzed. The component convolutional codes are considered to have memory 2 and 3, respectively, and their generator polynomials are both primitive and nonprimitive. The performances of asymmetric turbo coded modulation were evaluated performing simulations to obtain the bit error rate (BER) and the frame error rate (FER). Primitive polynomials lead to better performances for FER, whereas the nonprimitive ones lead to slightly improvements in low SNR range.

Keywords: turbo coded modulation, antenna diversity, asymmetric turbo codes

CAPACITY ANALYSES FOR IEEE 802.11N NARROWBAND AND WIDEBAND CHANNEL MODELING

Irina I VERMESAN, Tudor PALADE, Rebeca M COLDA

Abstract: : In this paper we investigate the channel capacity when MIMO (Multiple Input Multiple Output) technology is employed for wireless communication systems that are designed under IEEE 802.11n conditions. First, we emphasis the methods of modeling the NLOS (Non Line of Sight) narrowband and wideband communication channel. Afterwards, the channel capacity behavior is analyzed as a function of ray propagation physical parameters given in the standard, such as: AoA/AoD (Angle of Arrival/ Angle of Departure), AS (Angle Spread), number of clusters, number of antennas and inter – element distance. The spatial correlation properties are also incorporated in our investigation.

Keywords: : narrowband channel modeling, wideband, capacity, spatial correlation

FILTER BANK SYNTHESIS FOR ADAPTED WAVELET ANALYSIS

Zoltan German SALLO

Abstract: : The multiresolution theory of orthogonal wavelets proves that any conjugate mirror filter characterizes a wavelet that generates an orthonormal basis of L2R. This paper presents a method to obtain a discrete wavelet function, through FIR filter synthesis starting from a random discrete sequence. This sequence is used as a FIR filter which generates the four conjugate mirror filters to implement the discrete wavelet transform. The refinement of this sequence is carried out by a learning structure which follows to minimize the error between the signal and its reconstructed form from first order decomposition.

Keywords: : wavelet analysis, filter banks, perfect reconstruction

DEVELOPMENT FRAMEWORK FOR CONGESTION AVOIDANCE MECHANISMS

Vasile Teodor DADARLAT, Raluca JELER, Adrian PECULEA, Bogdan IANCU, Emil CEBUC, Cosmin ARDELEAN

Abstract: The paper is presenting a novel approach for the design and implementation of a development framework for congestion avoidance mechanisms. A method for dynamically adjustment of the queues length function of their average queue size is also proposed. The developed algorithm, called improved WRED, uses this method which allows for a better use of the bandwidth of the link. Both the proposed algorithm and the traditional WRED were tested using the framework for the development of congestion avoidance mechanisms. The experiments showed that the improved WRED has better performance than the traditional.

Keywords: framework, WRED, QoS, congestion avoidance, algorithm.

MODIFIED DIJKSTRA'S ALGORITHM WITH CROSS-LAYER QOS

Andrei Bogdan RUS, Virgil DOBROTA, Adrian VEDINAS, Georgeta BOANEA, Melinda BARABAS

Abstract: This paper presents a modified Dijkstra’s algorithm that calculates the distance between multiple sources and a single destination. It corrects the deficiencies of the classical approach by taking into account the dynamicity of the QoS parameters at the Physical Layer and MAC Sub-layer. The proposed composite metric is based on the available transfer rate, one-way delay and bit error rate, all of them measured or calculated in real time due to a Cross-Layer QoS software module. The proof-of- concept was obtained by simulations in OMNET++.

Keywords: Cross-layer, modified Dijkstra, QoS parameters

Number 2/2010

ACTIVE BALANCING METHOD FOR BATTERY CELL EQUALIZATION

Dorin CADAR, Dorin PETREUŞ, Toma PĂTĂRĂU, Niculaie PALAGHIŢĂ

Technical University of Cluj-Napoca, Faculty of Electronics, Telecommunications and Information Technology,

26-28 G. Bariţiu Street, 400027 Cluj-Napoca, Romania, Phone +40264401415, E-mail: Dorin.Cadar@ael.utcluj.ro

Abstract: The emerging need for more power has led to the development of series-parallel connected battery cells. Having a more complex system also brought with it new challenges. One of these is the problem of cell imbalance. Balancing algorithms are based on extracting or adding charge in order to have balanced cells. Their goal is to protect the battery from damage and to help prolong the battery’s life. Without a balancing system the individual cell voltage will drift away, the total capacity of the pack will decrease more rapidly during operation and also the estimation of the state of charge will be unreal. This paper presents the theory behind the most important balancing algorithms developed so far and also proposes another method of cell balancing, method tested both through simulation and implementation.

Keywords: battery cell, balancing algorithm, charge

BATTERY AND SUPERCAPACITOR CHARGER BASED ON LLC CONVERTER

Dorin PETREUŞ, Toma PĂTĂRĂU, Ionuţ CIOCAN

Technical University of Cluj-Napoca, Faculty of Electronics, Telecommunications and Information Technology,

26-28 G. Bariţiu Street, 400027 Cluj-Napoca, Romania, Phone +40264401415, E-mail: Dorin.Cadar@ael.utcluj.ro

Abstract: The need for a small economical power supply for battery chargers has increased in the last couple of years. A LLC converter is used as a battery charger due to its low EMI noise, high power integration and high efficiency. The paper presents a more accurate approach for the design and analysis of the LLC converter. A comparison between the calculations, the simulations and the practical results is also presented. A new analysis and design method which enables the use of the LLC converter as a battery charger and super capacitor charger is presented.

Keywords: resonant converters, battery charger, ZVT, ZCT.

Acoustic Analysis of A Room

Norbert TOMA, Marina Dana ŢOPA, Botond Sandor KIREI, Ioana HOMĂNĂ

Faculty of Electronics, Telecommunications and Information Technology, Technical University of Cluj-Napoca

Str. G. Bariţiu nr. 26-28, 400027 Cluj-Napoca, Romania, Tel: +40264401243, Fax: +40264591689, Marina.Topa@bel.utcluj.ro

Abstract: The paper presents the acoustic analysis of a room using both software and hardware tools. First several methods for acoustic parameters estimation were tested. The most accurate measurements were used for building 3D images of the room’s impulse response. Next the room was analyzed in realistic conditions and maps of acoustic parameters were plotted. Conclusions regarding the acoustics of the room were drawn.

Keywords: room acoustics, impulse response, acoustic parameters, plenacoustic function, acoustic sources

A SIMULATION OF THE PERFECTLY MATCHED LAYER IN THE 3-D CASE

Ioana SĂRĂCUŢ, Victor POPESCU, Dan Ovidiu MICU

Technical University of Cluj-Napoca, G.Baritiu Street 26-28, Cluj-Napoca, phone 0264-401803

E-mails: Ioana.Saracut@bel.utcluj.ro , Victor.Popescu@bel.utcluj.ro , DanO.Micu@et.utcluj.ro

Abstract: The Perfectly Matched Layer (PML) technique, introduced by J. P. Berenger in 1994, is used for solving unbounded space problems. In this paper we implemented in Matlab a three dimensional Finite-Difference Time-Domain coordinate space surrounded by PML. First we evaluated the performances of the PML when a plane wave having a Gaussian pulse profile propagates. Then a dipole antenna is simulated in the same computational space and some simulation results, including the radiation pattern, are presented.

Keywords: Finite-Difference Time-Domain, Perfectly Matched Layer, electromagnetic field, dipole antenna

WORKFLOW BASED SERVICE COMPOSITION USING GENETIC ALGORITHMS

Florin-Claudiu POP, Marcel CREMENE, Mircea-Florin VAIDA

The Technical University of Cluj-Napoca, Faculty of Electronics, Telecommunications and Information Technology

Department of Communications, 26 – 28 Baritiu, 400027 Cluj-Napoca, Romania, Phone: (+40) 264 401810

Email: { Florin.Pop, Cremene, Mircea.Vaida }@com.utcluj.ro

Abstract: One common direction in service oriented computing is to use predefined workflows to compose new services that combine the functionality of existing services. But the problem with this approach is that services can’t be composed for which workflows are not available. We propose a genetic algorithm that combines workflows in order to find the best solution that satisfies a set of objectives formulated using imperative natural language requests. The function that measures how close a solution is to what the user expects from the composed service is a semantic similarity function, called the conceptual distance.

Keywords: web services, service composition, semantic similarity, genetic algorithms

A NOVEL END-TO-END QOS FRAMEWORK OVER HETEROGENEOUS NETWORKS - AN ARCHITECTURAL APPROACH

Bogdan IANCU, Vasile DADARLAT, Adrian PECULEA

Technical University of Cluj-Napoca, Faculty of Automation and Computer Science, Computer Science Department

26-28 G. Baritiu street, Cluj-Napoca, Romania, Tel: +40264202369, {Bogdan.Iancu, Vasile.Dadarlat, Adrian.Peculea}@cs.utcluj.ro

Abstract: End-to-end QoS (Quality of Service) provisioning over heterogeneous networks is a major challenge. The poor communication between Service Providers, the increasing complexity of the supported services, the need for fulfillment of end-to-end requirements represent the main problems to be solved by the new QoS frameworks. This paper presents a novel system architecture for an end-to-end QoS framework over heterogeneous networks, that aims to guarantee network performances and to provision end-to-end QoS over multiple autonomous systems.

Keywords: end-to-end QoS, heterogeneous networks, architecture, autonomous systems.

TLS PROTOCOL: SECURE PROTOCOL WITH CLIENT PUZZLES

Raluca CATARGIU, Monica BORDA

Faculty of Electronics,Telecommunications and Information Technology , Cluj-Napoca

Technical University of Cluj-Napoca, 26-28 Bariţiu Street, 400027, ralu_catargiu@yahoo.com

Abstract: Client puzzles are commonly proposed as a solution to denial-of-service attacks. We analyzed the TLS protocol and implement Client Puzzles algorithm. We pursued the following objectives: analyze TLS handshake protocol and implement Client Puzzles algorithm using Hash Functions, Diffie-Hellman Base Puzzle Scheme and Threshold Puzzles. The originality of the paper is due to a comparative study of methods used to create the Client Puzzle solution. We also present measurements of execution time when our modified protocol is under attack.

Keywords: client puzzles, attack, threshold client puzzles.

USING DYNAMIC TIME WARPING ALGORITHM OPTIMIZATION FOR FAST HUMAN ACTION RECOGNITION

Tamás VAJDA

Sapientia Hungarian University of Transylvania, Tîrgu Mures, Romania

Abstract: In this paper, we present an approach based on dynamic programming and neural network for recognition and matching human action. Each human action is represented by the angular motion of the body parts. Each body part angular motion is represented by an one-dimensional time series. These time series are then compared separately for every body part with templates using dynamic programming (DTW). The results of the comparisons are used as input for a neural network that classifies the human action.

Keywords: Dynamic Time Warping, action recognition.

ANALYSING THE STABILITY OF CIRCUITS BASED ON OPERATIONAL AMPLIFIERS BY USING FREQUENCY-DOMAIN SIMULATIONS

Marius NEAG, Raul ONEŢ, Marina ŢOPA

Technical University of Cluj-Napoca, Faculty of Electronics, Telecommunications and Information Technology

26, G. Baritiu St, Cluj-Napoca, Romania, Phone: +40264 401470, Fax:+40264 591689, Marius.Neag@bel.utcluj.ro

Abstract: This paper analyzes in detail two of the most popular methods of determining the loop gain of OpAmp-based feedback circuits through frequency-domain Spice simulations. The limitations of the simpler method – that involves breaking the feedback loop by inserting an independent voltage source with DC=0 and AC=1 – are highlighted in comparison with a more precise method, based on the Rosenstark theorem. The discussion encompasses all types of amplifiers: the traditional (V-V) OpAmp, the Current-Feedback OpAmp (CFB-OA), the transconductance OpAmp (OTA) and the Current – Current OpAmp with asymmetric inputs (such as a second-generation current conveyor). Recommendations are made based on analytical analysis and simulation results.

Keywords: OpAmp based feedback circuits, stability, small-signal loop gain, module and phase margin, Spice simulations

Number 1/2010

POLYMORPHIC AND METAMORPHIC CODE APPLICATIONS IN PORTABLE EXECUTABLE FILES PROTECTION

Liviu PETREAN

“Emil Racoviţă” High School Baia Mare, 56 V. Alecsandri

Abstract: Assembly code obfuscation is one of the most popular ways used by software developers to protect their intellectual property. This paper is reviewing the methods of software security employing metamorphic and polymorphic code transformations used mostly by computer viruses.

Key words: code, polymorphic, portable

DESIGN OF A PROGRAMMABLE CONTROL SYSTEM

Andrei COZMA Dan PITICA

Applied Electronics Department, Technical University of Cluj Napoca, Romania

E-mail: andrei.cozma@ael.utcluj.ro, dan.pitica@ael.utcluj.ro

Abstract: This paper presents the design of a system intended to be used for automatic control applications. The system consists of a signal acquisition module, a programmable high speed Digital Signal Processing (DSP) core, a Microcontroller Unit (MCU), an output module and a communication module. Both analog and digital signals can be given as input to the system. The analog signals are digitized by a high speed analog to digital converter, while the digital signals are read through an I2C bus. The programmable DSP core can perform basic arithmetic operations, finite and infinite impulse response filtering and fuzzy logic operations at high speed and with a high degree of parallelism on the data received from the signal acquisition module. The MCU is a soft processor core with a RISC instruction set and it is used for controlling the operation of all the other modules and for implementing more complicated control algorithms that cannot be performed by the DSP core. The output module contains multiple Pulse Width Modulated (PWM) signal generators and high speed Digital to Analog Converters (DAC) for analog control signals generation from the digital control signals received from the MCU or DSP core. The communication module transfers data to/from a PC through a USB connection. By integrating all the above mentioned modules into one single chip a complete real time control core is provided.

Keywords: automatic control, microcontroller, digital signal processor

TEXT-INDEPENDENT SPEAKER VERIFICATION: A COMPARATIVE ANALYSIS STUDY

Mohamed SOLTANE, Noureddine DOGHMANE and Noureddine GUERSI

Electronics Department, Faculty of engineering science

Badji Mokhtar University of Annaba, 23000 Annaba - Algeria

soltane@lri-annaba.net & xor99@hotmail.com , ndoghmane@univ-annaba.org, guersi54@yahoo.fr

Abstract: Gaussian mixture models (GMMs) remain the state of the art technique for modeling spectral envelope features for speech recognition systems. This paper presents a comparative analysis of the performance of three estimation algorithms Expectation Maximization (EM), Greedy EM Algorithm (GEM) and Figueiredo-Jain Algorithm (FJ) based Gaussian mixture models (GMMs) for text-independent speech biometrics verification. The simulation results are showed significant performance achievements. The test performance of, EER=0.26 % for "EM", EER=0.21 % for "GEM" and EER=0.16 % for "FJ", show that the behavioral information scheme of speech biometrics is more robust and have a discriminating power, which can be explored for identity authentication.

Keywords: Biometric authentication, behavioral, speech, soft decision and Gaussian Mixture Modal, EM, GEM and FJ.

ASYMMETRIC DIFFUSION AND FUSION TECHNIQUES FOR IMAGE RESTORATION

Romulus TEREBES¹ Monica BORDA¹ Sorin POP¹ Cosmin LUDUSAN^1,2 Olivier LAVIALLE²

¹Technical University of Cluj-Napoca, ²CNRS, IMS, UMR 5218

¹15,C.Daicoviciu Street, +40-264-401564, ²351 Cours de la libération, 33405 Talence, France

Romulus.Terebes@com.utcluj.ro

Abstract: We propose a novel method for restoring and enhancing images. The method is based on the Partial Differential Equations (PDE) framework and image fusion techniques. The degraded image is processed independently with two PDE based diffusion filters with different theoretical properties, an asymmetric forward diffusion equation and an evolved shock filter, and then fusion is performed at an intermediate results level. The procedure is iterated for a predefined number of steps and the restored or enhanced image is obtained as the output of the last fusion step. Through application samples we show that the method can be successfully applied for restoring images composed of oriented patterns and degraded by additive Gaussian noise and Gaussian blur.

Keywords: Diffusion, partial differential equations, shock filters, image fusion

DNA PATTERNS LOCALISATION USING SPECTROGRAMS

Alin VOINA, Petre G. POP

Comm. Dept., Technical University of Cluj-Napoca

26-28 Baritiu str. 400027, Cluj-Napoca, ROMANIA, e-mail: alin.voina@com.utcluj.ro

Abstract. This paper presents the possibilities for processing and analysis of genomic sequences which are converted into a numerical representation. There were used two types of symbol mapping: indicator sequences and quartic mapping. The resulted sequences were analyzed using a spectral analysis, completed with the obtaining of BW spectrogram, technique which offers the possibility for a unique and innovative visualization of periodical properties of genomic sequence. The advantages of this kind of representation are that offers an overview of the whole genomic sequence without using any a priori data. Once we have the spectrogram, we can obtain approximate information about positions and length of the repeated sequences.

Keywords: DNA repeats,spectral analysis, Fourier transform, spectrogram, genomic sequence

A STRUCTURE FOR HARD HANDOVER ANALYSIS USING AGENTS TECHNOLOGY

Gabriel SIRBU¹, Ion BOGDAN²

¹ Dunarea de Jos University of Galati, Electronics and Telecommunications Dept., Domneasca-47 Str., Galati-800008, Romania, email gabriel.sirbu@ugal.ro

² Gheorghe Asachi Technical University of Iasi, Telecommunications Dept., Blvd. Carol I - 11, Iasi-700506, Romania, email bogdani@etc.tuiasi.ro

Abstract: The mobility of the users in a cellular mobile environment is involving the use of the radio resources. The main aspect, which characterizes this attribute, is the hard handover and this must be carried out without blocking the existing calls of the static positioned users. Combining the two sets of users, namely static positioned users and mobile users, the resulting system must be able to manage the conflict situations, resulting in a minimum blocking probability, achieved with a centralized structure, or a distributed structure. Our work is introducing a minimal distributed structure that can be used to analyze the behavior of a cellular mobile system, based on the agents technology. The structure includes two agents and each of them implements the entire operations specific to a dynamic channel allocation scheme, into a cell. The third agent is added in order to manage the eventual hard handovers requests. This three agent minimal structure can be then multiplied in order to extend to, to simulate and to analyze various real conditions.

Keywords: cellular communications, hard handover, user mobility, channel management, Dynamic Channel Allocation Scheme, cost function, MASE technology, fixed agents, blocked call probability, forced call probability.

Number 4/2009

MEDICAL DIAGNOSIS SYSTEM BASED ON IRIS ANALYSIS

Adrian LODIN¹ Sorina DEMEA²

¹Technical University of Cluj-Napoca, Faculty of Electronics, Telecommunications and Information Technology,

26-28 G. Baritiu Street, Tel. +40 264 401804, Fax. +40 264 591340, E-mail: Adrian.Lodin@bel.utcluj.ro

²Oftalmological Center of Investigation REVIEW, 9 Motilor Street, Tel/fax +40 364 107206 Cluj-Napoca, Romania

Abstract: The goal of this study is to present a system which is used to process iris images for medical purposes. Such a system should assist a diagnosis based on correlation between medical pathology and different sectors from the surface of the iris. Iris surface texture regions, which offer useful information, can be revealed using computerized texture and color analysis. Iridologists work showed that locations of those regions upon segmented iridology charts point out an interrelation between map sectors and internal body system medical pathology. Our goal is to automatically identify those regions and established an assist diagnosis. The final automatically generated diagnosis needs user approval, thus making the system semi-automatic.

Key words: iris recognition, medical pathology, texture regions, diagnosis, Hough Transform.

LABVIEW FPGA BASED NOISE CANCELLING USING THE LMS ADAPTIVE ALGORITHM

Erwin SZOPOS¹ Horia HEDESIU²

¹Bases of Electronics Department, ²Electrical Machines, Marketing and Management Department,

Technical University of Cluj-Napoca, Romania

26-28 G. Baritiu str., Cluj-Napoca, Romania, Tel: +40264401803; Fax: +40264591340 Erwin.Szopos@bel.utcluj.ro, Horia.Hedesiu@mae.utcluj.ro

Abstract: This paper proposes an architecture for implementing the Least Mean Square (LMS) adaptive algorithm, using a 20 bit fixed-point arithmetic representation. The architecture length was established to 16, but it can be easily modified. This is an advantage for large filter orders. The method can also be applied to other LMS versions. This architecture is implemented using the NI cRIO-9104 FPGA chassis. The NI cRIO-9012 is a real-time module used for signal control and storage. Experiments were done regarding signal to noise ratio (SNR), filter length and type of input signals. The obtained results indicate the implemented algorithm as having high performance, while still incurring some limitations. The design is evaluated in terms of SNR, filter length and FPGA resources.

Keywords: LMS, FPGA, SNR, real-time module, noise cancelling, filter length, step-size.

A NOVEL APPROACH FOR EFFICIENCY ENHANCEMENT AND SIZE MINIATURIZATION OF UWB PRINTED ANTENNAS

Ramu PILLALAMARI ¹⁾, Sasibhushana Rao GOTTAPU² S. Srinivasa KUMAR¹

¹⁾Reliance Technology and Innovation Centre, Reliance Communications Ltd. India

¹⁾Radio Frequency and Microwave Laboratory, Dept. of Electronics and Communication Engineering, Jawaharlal Nehru Technological University Kakinada, Andhra Pradesh, India

²Andhra University, Visakhapatnam, Andhra Pradesh, India, Corresponding Author: ramu06410230@gmail.com

Abstract: The printed antenna is one of the most preferred antenna structures for low cost and compact design of wireless communication systems. In this paper we have investigated a new approach for improving the radiation efficiency and performance of the antennas with the size miniaturization, in particular we have simulated two types of UWB printed monopole antennas for proving this approach with results: circular patch and Compact Miniaturized Semi-Circular patch UWB monopole antennas and in detail investigation was presented on size miniaturization in order to achieve very compactness and high radiation efficiency with out degradation of the functional parameters and overall performance. Simple rectangular microstrip lines are used for feeding the printed monopole antennas. This UWB monopole antenna designed works well for the whole UWB frequency band 3.1-10.6GHz.

Key words: UWB, Semicircular, Miniaturization printed monopole antennas, Microstrip lines.

FORECASTING BY NEURAL NETWORKS IN THE WAVELET DOMAIN

Ion RĂILEAN, Sorin MOGA, Monica BORDA

Technical University of Cluj-Napoca, 15 Constantin Daicoviciu Street,Cluj Napoca,400020,Romania

Telecom Bretagne, Technopôle Brest-Iroise - CS 83818 - 29238 Brest Cedex 3 – France

Email : raileanion@yahoo.com

Abstract: This paper presents a forecasting method for time series. This method combines the wavelet analysis and several forecasting techniques such as Artificial Neural Networks (ANN), linear regression and random walk. The proposed method is tested using three real time series: the first contains historical data recorded during eight weeks from a WiMAX network and the other two are based on financial series. It is shown that AI with wavelet analysis can be an efficient and versatile approach in time series prediction for small periods time interval (up to 1 month). For long time interval, the best method used is Linear Regression technique. Also we compared the results obtained using various types of wavelets. The results show that Daubechies 1 (db1) and Reverse biorthogonal 1 (rbio1.1) give the best results.

Key words: Time series, Wavelet transform, forecasting, Neural Networks

A PSPICE MODEL FOR T MATCHING CIRCUITS

Ioana SĂRĂCUŢ Victor POPESCU

Technical University of Cluj-Napoca,

G.Baritiu Street 26-28, Cluj-Napoca, phone 0264-401803

E-mail: Ioana.Saracut@bel.utcluj.ro, Victor.Popescu@bel.utcluj.roIoana.Saracut@bel.utcluj.roVictor.Popescu@bel.utcluj.ro

Abstract: In electronics, impedance matching is an engineering technique employed in circuit design for matching unequal source and load impedances. This can be done by inserting a matching circuit between the source and a load. For given values of the source resistance, load resistance, the modulus of the coupling factor and the frequency at which the matching is achieved, four different circuit result. In this paper, we simplified the calculation of the reactances of the elements and presented a PSpice model that can be used to model any of the four matching circuits. Hence the model can be used as an impedance matching circuit without the need to calculate the nature and the values of its elements. Then we compared the time and frequency behaviors of a circuit that uses this PSpice model to the case when the same circuit doesn’t use it.

Key words: propagation, matching circuit, working frequency, reflected wave.

EVALUATING THE PERFORMANCES OF THE CASTGATE TUNNEL SERVER OVER TCP AND UDP LINKS IN MULTI-CLIENT CONFIGURATION

Melinda BARABAS Georgeta L. BOANEA Kris STEENHAUT* Virgil DOBROTA

Technical University of Cluj-Napoca, Communications Department

26-28 George Baritiu Street, 400027 Cluj-Napoca, Romania, Tel: +40-264-401226

E-mails: {Melinda.Barabas, Georgeta.Boanea, Virgil.Dobrota}@com.utcluj.ro

* Vrije Universiteit Brussel, ETRO Department, Pleinlaan 2, B-1050 Brussels, Belgium

E-mail: Kris.Steenhaut@vub.ac.be

Abstract: The CastGate architecture defines a transitory tunneling solution, offering access to native multicast. This paper describes the implementation of a testing application (CastGate Tester - CT) for the CastGate Tunnel Server (TS), using TCP and UDP links. The goal is to evaluate the performance of the TS in a controlled environment, by emulating a variable number of clients that connect to the server. Two scenarios were defined: load test and stress test. Based on these, the limitations of the CastGate Tunnel Server were identified. The obtained results can be used in the optimization stages of the TS.

Key words: multicast, CastGate project, UMTP*, Tunnel Server, Tunnel Client, load test, stress test.

ASPECTS OF ALGORITHM DEVELOPMENT FOR SYSTEMS WITH ONLINE DETECTION AND RECOGNITION OF TV COMMERCIALS

Radu ARSINTE

Technical University of Cluj-Napoca, Faculty of Electronics, Telecommunications and Information Technology, Communications Department, Tel: +40-264-595699, Str. Baritiu 26-28, Radu.Arsinte@com.utcluj.ro

Abstract: The paper describes a series of research stages in the development process for an automated system, able to detect commercial brakes in TV signals, and recognize a basic set of logos form the TV commercials. First, the conceptual diagram of the system is presented. Theoretical aspects of the recognition process are presented, and there are based on image matching algorithms. The paper presents also the test bench implemented to verify the correctness of the algorithm. The test bench is based on EasyAccess environment from eVision. Using the described test bench it is possible to tune the main parameters of the algorithm and realize extensive tests for different conditions and images. Using this test bench made possible to realize over 600 matching experiments using 20 logos of the most important international brands and 30 images captured in real conditions using different TV tuners.

Key words: Video acquisition, Commercial brake, Logo Detection, Video Streaming

COMPARISON OF LMS ALGORITHM DERIVATIVES USING LABVIEW FPGA

Erwin SZOPOS¹ Horia HEDESIU² Victor POPESCU¹ Lelia FESTILA¹

¹Bases of Electronics Department, ²Electrical Machines, Marketing and Management Department, Technical University of Cluj-Napoca, Romania

26-28 G. Baritiu str., Cluj-Napoca, Romania, Tel: +40264401803; Fax: +40264591340 Erwin.Szopos@bel.utcluj.ro, Horia.Hedesiu@mae.utcluj.ro, Victor.Popescu@bel.utcluj.ro, Lelia.Festila@bel.utcluj.ro

Abstract: The LMS algorithm derivatives have found wide application in many areas of adaptive signal processing and control. In this paper we study the tracking performance of the LMS derivatives in adaptive noise cancellation for a speech signal corrupted by white noise. The experiments were done for 16–tap filter lengths and as for the hardware platform the NI cRIO-9104 FPGA chassis and the NI cRIO-9014 real-time module were used. The obtained results were compared to highlight the performances of each of the LMS derivatives. The results of the experiments confirm that the NLMS variant provides the most enhanced SNR and the better tracking ability is offered by the LLMS in a 16-tap adaptive filter. The performances of the algorithms are evaluated in terms of signal-to-noise ratio (SNR) at the output of the adaptive system, tracking ability and hardware usage.

Keywords: LMS derivatives, FPGA, SNR, pipeline, tracking, hardware usage.

Number 3/2009

STUDY ON THE EFFECTS OF PRECIPITATION ON EARTH-to-SATELLITE LINKS IN THE Ka BAND

Alexandru Luigi RICOBON¹ Ramona Maria TRESTIAN²

(¹) Technical University of Cluj-Napoca, Romania; (²) Dublin City University, Ireland

Abstract: The use of higher frequency bands, above 10 GHz, for satellite communication provides a number of important benefits. It relieves congestion in the lower frequencies which are sheared with terrestrial links, in the same time providing larger bandwidths and cheaper implementation of terrestrial equipment. However, the severity of atmospheric influence on the radiowave propagation (especially due to rain) increases markedly with frequency. It is therefore necessary to identify and predict the effects of hydrometeors on wireless links.

Key words: Satellite links, Ka Band, Precipitation effects, Radar maps

A VLSI IMPLEMENTATION OF A NEW LOW VOLTAGE 4^th ORDER DIFFERENTIAL G_m-C BAND-PASS FILTERS FOR DIFFERENT APPROXIMATION IN CMOS TECHNOLOGY

Radu Gabriel BOZOMITU Vlad CEHAN

Faculty of Electronics, Telecommunications and Information Technology, “Gh. Asachi” Technical University,

Carol I No. 11 Av., 700506, Iaşi, Romania, Phone: +40-232-213737, bozomitu@etc.tuiasi.ro, vlcehan@etc.tuiasi.ro

Abstract: In this paper we present a new low voltage 4^th order differential G_m-C band-pass filter (BPF) for different approximations (Butterworth or Chebyshev), which has been designed in CMOS technology. This differential BPF is composed of two G_m-C biquad structures in cascade connection. The type of band-pass filter approximation (Butterworth or Chebyshev) can be set by an adequate choice of grounded capacitors, using digital command logic. The proposed G_m-C filter architecture is attractive for VLSI implementation and offers the possibility of tuning the centre frequency and the selectivity, using external biasing currents or modifying the grounded capacitor values. The proposed structure provides a ±15% corners variation of the centre frequency, a dynamic range of 200mV_pp(diff), distortion THD<1%, and a 10mA current consumption from a 1.8V voltage supply. The simulations performed in 65nm CMOS technology confirm the theoretical results.

Key words: Gm-C filter, biquad, transconductor, OTA, dynamic range, Butterworth, Chebyshev, CMOS, VLSI.

ON-LINE SIGNATURE RECOGNITION USING A GLOBAL FEATURES FUSION APPROACH

Eugen LUPU¹ Simina EMERICH¹ Francois Beaufort²

¹Technical University of Cluj-Napoca, Communications Dept.

26-28 Baritiu str.,Cluj-Napoca, Romania, Phone: +40-264-401266, Eugen.Lupu@com.utcluj.ro

²Ecole Supérieure d'Electronique de l'Ouest, Angers, France

Abstract: The paper presents a feature-based approach regarding on-line signature recognition, by employing the TESPAR - DZ matrices extracted from every signature. These matrices describe the different signature features shapes, such as x, y -coordinates, x, y - velocity, pressure etc. For better results, the fusion of different features was studied. Three signature databases have been employed in our experiments: DB1, DB2, our own signature databases and the Task2 database available for research purposes from the SVC2004 contest. In our work, two types of experiments were made: verification and identification (surveillance). These results are very promising taking into account the simplicity of template generation and the fact that we employed only five features in our experiments.

Key words: on-line signature, verification, identification, TESPAR, fusion, forgery, SVM.

NOVEL VOLTAGE-CONTROLLED AMPLIFIERS FOR MULTISTANDARD INTEGRATED RADIO RECEIVERS

Marius NEAG István KOVÁCS Raul ONEŢ Marina ŢOPA

Technical University of Cluj-Napoca, Faculty of Electronics, Telecommunications and Information Technology

26, G. Baritiu St, Cluj-Napoca, Romania, Phone: +40264 401470, Fax:+40264 591689, Marius.Neag@bel.utcluj.ro

Abstract: This paper proposes a new architecture for transconductance (Gm)-based variable-gain amplifiers (VGA) that

is better suited for multi-standard radio receivers than the classical two-Gm structure: its bandwidth and linearity are largely independent of the gain setting and both the gain range and the bandwidth can be programmed through digital controls. Unlike the classical structure - that uses two Gm cells and modifies the gain by changing the transconductance of at least one of them, usually by varying the biasing conditions - the new VGA employs three Gm cells with constant biasing; the gain variation is achieved through a differential current steering scheme. Two transistor-level implementations of the proposed VGA structure are presented, one using simple differential pairs and the other based on a more complex, highly linear Gm cell. New circuits for controlling the output common-mode voltage are proposed for both cases; these circuits do no require the placement of additional circuitry in the differential signal path. The VGAs were designed in a standard 0.18um CMOS technology to same specifications: to cover the gain range of 0dB-18dB while handling signals with amplitudes up to 800mVpkpkdiff without significant distortions; maximum bandwidth above 30MHz while driving 1pF; power consumption bellow 6mW. Simulation results show that both VGAs meet the requirements, thus validating the circuit implementations and proving the potential of the proposed architecture.

Key words: variable-gain amplifier; transconductor; differential current steering; multi-standard radio receivers.

image enhancement using a new shock filter formalism

Cosmin LUDUŞAN^{1, 2}, Olivier LAVIALLE², Sorin POP¹, Romulus TEREBE޹, Monica BORDA¹

¹Technical University of Cluj-Napoca, 26-28 Bariţiu Street, 400027, Cluj-Napoca, Romania

²Université de Bordeaux, UMR IMS 5218, 351 cours de la Libération, 33405, Talence Cedex, France

Abstract: We present a new approach based on Partial Differential Equations (PDEs) and shock filter theory for deblurring 2D Gaussian blurred images. The inherent problems of stability posed by the reverse heat equation and the discretization of shock filters are overcome by the use of only the initial conditions. This approach is not well suited for diffusion-oriented techniques since in this case the problem is ill-posed, but when dealing with multiple inputs (the case of fusion methods), it proves to provide sound results. The proposed deblurring model takes into account only the blur problem without having a noise removal component, this being a future step of our work.

Key words: partial differential equation, image fusion, shock filter, deblurring, image enhancement

A MEDICAL IMAGE FUSION METHOD FOR WEB DISTRIBUTED APPLICATIONS

Ligia CHIOREAN, Mircea F. VAIDA, Loreta SUTA

Department of Communications, Technical University of Cluj-Napoca, Cluj-Napoca, Romania

Chiorean.Ligia@com.utcluj.ro, Mircea.Vaida@com.utcluj.ro, suta_loreta@yahoo.com

Abstract: Medical images acquired with different medical modalities contain important diagnostic information. The combination of complementary data from these images can lead to more important information for diagnosis process. The fusion process allows combination of salient feature of these images. In this paper we present a method for medical image fusion, based on discrete wavelet transform. This method is implemented in a web distributed application, using Java technology. The web dedicated application allows physicians to realize a fusion from a remote place. We have also calculated some quantitative parameters for fusion process evaluation.

Key words: image fusion, wavelet transform, distributed application, multi-resolution decomposition.

Retrieving Call Detail Records from ASTERISK using SNMP

Cristian Mihai VANCEA Virgil DOBROTA

Technical University of Cluj-Napoca, Communications Department

26-28 George Baritiu Street, 400027 Cluj-Napoca, Tel: +40-264-401226, Fax: +40-264-597083

E-mails: {Mihai.Vancea,Virgil.Dobrota}@com.utcluj.ro

Abstract: Several SNMP agents could be integrated by IETF’s AgentX protocol which separates the communication with SNMP manager in two parts: AgentX between sub-agents and master agent, and SNMP between master agent and manager. The paper extends the SNMP software agent of the IP-based PBX Asterisk. The management information related to Application Layer (calls and charging) are collected in .log files, parsered and then stored into .xml files. Being an alternative to legacy commercial implementations, this solution has the advantage of using the SNMP, a generalized non-proprietary management protocol. This could be a step forward towards an integrated management where the access, distribution and core networks, together with applications are using the same mechanism which will not be external anymore as it is nowadays.

Key words: agent, Asterisk, management information base, manager, SNMP

A VLSI IMPLEMENTATION OF A NEW LOW VOLTAGE 5^th ORDER DIFFERENTIAL G_m-C BESSEL TYPE LOW-PASS FILTER WITH CONSTANT-G_m BIASING IN CMOS TECHNOLOGY

Radu Gabriel BOZOMITU, Vlad CEHAN

Faculty of Electronics, Telecommunications and Information Technology, “Gh. Asachi” Technical University,

Carol I No. 11 Av., 700506, Iaşi, Romania, Phone: +40-232-213737, bozomitu@etc.tuiasi.ro, vlcehan@etc.tuiasi.ro

Abstract: In this paper a new low voltage 5^th order G_m-C Bessel type low-pass filter (LPF) with constant-G_m biasing, designed using CMOS technology, is presented. The differential LPF is composed of two biquad structures and a first order low-pass filter. The cut-off frequency can be tuned in four steps (42 MHz, 35MHz, 27MHz and 14MHz) by modifying the grounded capacitors values, using digital command logic. In order to maintain the filter transconductance G_m independent of the process, temperature and supply voltage variations, the bias currents used by the proposed structure are made dependent on theses variations, and are given by a constant-G_m biasing source. The proposed structure provides a ±7% corners variation of the cut-off frequency, a dynamic range of 400mV_pp(diff), a distortion THD < 1%, and a 12mA current consumption from a 1.8V supply voltage. The simulations performed in 65nm CMOS technology confirm the theoretical results.

Key words: G_m-C filter, biquad, transconductor, OTA, dynamic range, Bessel, CMOS, VLSI.

BER PERFORMANCE EVALUATION OF A MOBILE WIMAX SYSTEM OVER AN ITU-R PEDESTRIAN B MULTIPATH CHANNEL

Rebeca Maria COLDA¹ Tudor PALADE¹ Emanuel PUŞCHIŢĂ¹ Irina VERMEŞAN¹ Ancuţa MOLDOVAN¹

Ştefan-Victor NICOLAESCU²

¹Technical University of Cluj-Napoca, 26-28 G.Bariţiu Street, 400027, Cluj-Napoca, Romania

Phone: +40264401403, Fax Number: +40264597083, Email:Rebeca.Colda@com.utcluj.ro

²National Communications Research Institute (INSCC), No. 6 Preciziei Street, Sector 6, Bucharest, Romania

Phone: +40213189266, Email: stnicol@co.cnscc.ro

Abstract: A realistic modeling of the radio channel’s propagation characteristics proves to be extremely important, especially when one desires to perform an accurate design of a wireless communication system. In this paper, we evaluate and optimize the performances of the ITU-R M.1225 Pedestrian B (Ped.B) channel model for a downlink (DL) mobile WiMAX system, starting from the requirements of certain multimedia services. The influence of parameters such as modulation, coding scheme and cyclic prefix (CP), was analyzed through simulations, in terms of the bit error rate (BER).

Key words: Mobile WiMAX, Ped.B channel model, modulation, coding scheme, cyclic prefix, BER.

COMBUSTION SOUND ANALYSIS TO CONTROL THE BURNING QUALITY

Eugen LUPU¹ Victor HODOR¹ Marius GHIURCAU¹

¹Technical University of Cluj-Napoca, Communications Dept.

26-28 Baritiu str.,Cluj-Napoca, Romania, Phone: +40-264-401266, Eugen.Lupu@com.utcluj.ro

Abstract: The quality of the burning process may be investigated by using different means, such as visual inspection, employing electro- chemical transducers or analyzing the sound generated by the burning process. This paper reveals attributes regarding a method to detect the different states of combustion in progress by analyzing sound analogy. These results may be then used in order to take appropriate decisions to maintain the burning process in an optimal state. The first results are very promising and encourage continuing this research in the acoustic relevance in burning quality detection. Due to the fair computational requirements of the method this may be implemented on low cost solutions like microcontrollers.

Key words: combustion quality, instability, acoustic relevance, TESPAR, archetypes.

Number 2/2009

HARDWARE STRATEGIES FOR IMAGE PROCESSING IN AN FPGA BASED MICROARRAY IMAGE PROCESSING SOC

Bogdan BELEAN Monica BORDA Albert FAZAKAS

Technical University of Cluj-Napoca

Str. Baritiu 26-28,Cluj-Napoca ; Bogdan.Belean@com.utcluj.ro

Abstract: The present paper describes a System on a Chip for microarray image processing together with the steps of a microarray experiment integrated in the proposed system. The system’s reduced size and the hardware algorithms proved to overcome the disadvantages of the existing software for microarray image processing. FPGA technology was chosen for the implementation due to its parallel computation capabilities and to the ease of reconfiguration. Hardware strategies for implementing image processing techniques are presented, together with a hardware implementation for edge detection of microarray spots using distributed memory and spatial computation.

Key words: cDNA Microarrays, FPGA, image processing, hardware algorithms.

RESOURCE MANAGEMENT IN HYBRID WIRELESS NETWORKS

USING INTELLIGENT MOBILE AGENTS

Alexandru L. RICOBON¹ Ramona M. TRESTIAN²

(¹) Technical University of Cluj-Napoca, Romania; (²) Dublin City University, Ireland

(1) alex.ricobon@com.utcluj.ro (2) ramona@eeng.dcu.ie

Abstract: Wireless networks are no more used only for data transfer and Internet access, but now also support voice and multimedia services. The tremendous demands from the users are pushing the development of mobile communications faster than ever before, leading to plenty of new advanced techniques emerging. Future wireless Internet will consist of different wireless technologies operating together. The key issue is to provide new services and maintain quality of service (QoS) in hybrid wireless networks. This can be done in many ways, one of those using mobile agents to travel across the network and configure the route or the application demands.

Key words: resource management, hybrid wireless networks, intelligent mobile agents.

OVERVIEW OF THE CROSS-LAYER PARADIGM EVOLVING TOWARDS FUTURE INTERNET

Andrei Bogdan RUS Virgil DOBROTA

Technical University of Cluj-Napoca, Communications Department, 26-28 George Baritiu Street,

Cluj-Napoca, Romania, Tel: +40-264-401226, E-mails: {bogdan.rus, virgil.dobrota}@com.utcluj.ro}

Abstract: The spectacular evolution of Internet services has requested significant improvements of the performances in communications networks. Cross-layering techniques have been selected as one of the most important issues in research, trying to change the classical OSI model and to define better mechanisms for scalability. In this paper we are investigating the main characteristics of this bi-directional vertical communication, breaking the claimed independence of physical, data link, network, transport, and application layers. Some deployment scenarios described herein could help the future Internet designers to follow a clean slate approach.

Key words: cross-layer, Future Internet, QoS

DIGITAL IMPLEMENTATION OF THE SIGMOID FUNCTION FOR FPGA CIRCUITS

Alin TISAN, Stefan ONIGA, Daniel MIC, Attila BUCHMAN

Electronic and Computer Department, North University of Baia Mare, Baia Mare, Romania

Str. Dr. Victor Babeş, nr. 62A, tel. 0362-401265 ext. 234, alin.tisan@ubm.ro

Abstract: In this paper, is proposed a method to implement in FPGA (Field Programmable Gate Array) circuits different approximation of the sigmoid function. Three previously published piecewise linear and one piecewise second-order approximation are analyzed from point of view of hardware resources utilization, induced errors caused by the approximation function and bits representation, power consumption and speed processing. The major benefit of the proposed method resides in the possibility to design neural networks by means of predefined block systems created in System Generator environment and the possibility to create a higher level design tools used to implement neural networks in logical circuits.

Key words: Sigmoid approximation, FPGA implementation, System Generator

SECRET WRITING BY DNA HYBRIDIZATION

Monica E. BORDA Olga TORNEA Tatiana HODOROGEA

Technical University of Cluj-Napoca, Communications Department

Gh. Baritiu str. 25-27, fax: 004-64-401575, Romania, E-mail: Monica.Borda@com.utcluj.ro

Abstract: This paper presents an original algorithm of secret writing by DNA hybridization, based on existing ideas described in the literature. In order to perform highly secure communication, the cryptographic, steganographic and biomolecular computation strength is used. The proposed algorithm is exemplified using matlab bioinformatics toolbox.

Key words: Secret writing, DNA hybridization, PCR, DNA cryptography, steganography, biomolecular computation

Acoustic ModelLINg and OPTIMization of A Room

Norbert TOMA, Marina TOPA, Irina MURESAN, Botond KIREI, Marius NEAG, Albert FAZAKAS

Faculty of Electronics, Telecommunications and Information Technology, Technical University of Cluj-Napoca

Str. G. Bariţiu nr. 26-28,400020 Cluj-Napoca, Romania, Tel: +40264401243; Fax: +40264591340 Marina.Topa@bel.utcluj.ro

Abstract: The paper presents the analysis and improvement of a room’s acoustics using both software and hardware tools. First a model of the room is proposed taking into account the comparison of simulation and experimental results. Next improvements in the architecture are suggested and then the optimal placement of loudspeakers and listeners is provided. The performance is measured in terms of acoustic parameters.

Key words: room acoustics, modelling, reverberation time, sound pressure, acoustic parameters.

SIMULINK LIBRARY OF BASIC BUILDING BLOCKS FOR TERNARY LOGIC

Emilia SIPOS, Gabriel OLTEAN, Costin MIRON

Bases of Electronics Department, Technical University of Cluj-Napoca

26-28 G. Baritiu str., Cluj-Napoca, Romania, Tel: +40264401470; Fax: +40264591340;

Emilia.Sipos@bel.utcluj.ro

Abstract: A library of basic building blocks implemented in Simulink for ternary logic is presented. The basic blocks are: inverters, minimum, negated-minimum, maximum and negated-maximum. The considered ternary logic is unbalanced ones, with 0, 1 and 2 logic levels. With basic building blocks we implement the ternary D flip-flap-flop, with binary and ternary clock. The simulation results validate the correct operation for all implemented building blocks.

Keywords: ternary inverters, minim and maxim ternary circuits, D flip-flap-flop, Simulink block

RELEVANT CONTEXT DISCOVERY FOR PERVASIVE SERVICES INVOLVING USER CONTROL

Marcel CREMENE¹, Alin DRIMUS³, Jean-Yves TIGLI², Stephane LAVIROTTE², Gaëtan REY², Michel RIVEILL², Costin MIRON¹, Mircea VAIDA¹

¹Technical University of Cluj-Napoca, Communications, {cremene, vaida}@com.utcluj.ro,miron@bel.utcluj.ro

²University of Nice Sophia-Antipolis, Ecole Polytechnique, {tigli, lavirott, gaetan.rey, riveill}@unice.fr

³University of Southern, SDU, Denmark,drimus@mci.sdu.dk

Abstract: Dynamic context adaptation is a central concept in Pervasive and Ubiquitous Computing. In this paper we have analyzed the problem of context relevance and we have chosen an approach where the user is also involved also in the relevance control. The advantage of involving the user is motivated by the fact that a completely automatic context management cannot deal with unpredicted situations. The proposed solution was implemented on the top of WComp middleware. An easy to use interface let the user the possibility to easily manage its context.

Key words: Ubiquitous computing, Relevant context, Context discovery, Intelligent Devices.

MAXIMUM POWER POINT TRACKING SIMULATOR IN CHARGING PHOTOVOLTAIC SYSTEMS

Dorin M. PETREUŞ Ionuţ C. CIOCAN Adina R. RUSU Dorin V. CADAR

Technical University of Cluj-Napoca, Faculty of Electronics, Telecommunications and Information Technology,

26-28 G. Bariţiu Street, Cluj-Napoca, Romania, phone: 0264 401 412, email: Dorin.Petreus@ael.utcluj.ro

Abstract: The task of Maximum Power Point Tracking (MPPT) is to operate with photovoltaic (PV) modules in a manner that allows them to produce all the power they are capable of. In this paper a system for modeling different MPPT algorithms is presented. The functionality of the model proposed was validated through the comparison of the simulation results with the ones experimentally obtained from the implemented evaluation board. Different algorithms were developed in C language using Keil software 8051 development tool, µVision. The maximization of the output power of PV system is controlled through a 8051 microcontroller. The entire PV system was simulated using Proteus 7 Professional and can be used to test any MPPT algorithm.

Key words: MPPT algorithms, PV module, macro-model.

Number 1/2009

Fiber segmentation in composite materials using marked point processes

Barna KERESZTES^1,2, Olivier LAVIALLE¹, Sorin POP², Monica BORDA²

(1) Université de Bordeaux, LASIS - IMS – 351, Crs. de la Libération, 33405 Talence Cedex

(2) Technical University of Cluj-Napoca 15 Daicoviciu Street, 400020 Cluj-Napoca, Romania

e-mail: barna.keresztes@ims-bordeaux.fr tel: +33 540003624

Abstract: This paper presents a new method dedicated to unsupervised 2D segmentation of fibers in a section of composite carbon-fiber materials. The framework relies on a marked point process algorithm. We shall create random elliptical objects to fit the fiber distribution in the image. The interaction rules between the objects complete the model. Using a Markov Chain Monte Carlo (MCMC) method, the algorithm converges to a configuration which is close to the fiber distribution in the images. At each step, the configuration is evaluated considering its proximity to the target distribution. In order to achieve this task, we propose a mixed data model using both grey level values and gradients to evaluate the likelihood of the current configuration. This mixed model overcomes the problems of luminance variation, contour discontinuities and high noise level. Finally, the results on the composite material sections illustrate the efficiency of the segmentation and suggest that the marked point processes can be a promising tool for fiber detection.

Keywords: marked point process, composite materials, MCMC methods

DIVIDE-AND-CONQUER PIECEWISE LINEAR APPROXIMATION OF GAIN AND PHASE EVALUATION

Lacrimioara GRAMA¹ Corneliu RUSU²

1;2Technical University of Cluj-Napoca, Faculty of Electronics, Telecommunications and Information Technology,26-28 G. Baritiu Street, Tel. +40 264 401804, Fax. +40 264 591340,

1 E-mail: Lacrimioara.Grama@bel.utcluj.ro 2 E-mail: Corneliu.Rusu@bel.utcluj.ro

Abstract: Certain approaches to phase approximation ask as a first step in implementation for a piecewise linear fitting of gain. When the breakpoints are given, there are few ways to determine the slopes of the broken line approximation. In this paper we determine the breakpoints using a divide-and-conquer approach. Results to piecewise linear approximation of gain and of the resulting phase approximation are presented. For this purpose, we consider certain frequency responses, then the gain data are corrupted or altered.

Keywords: piecewise linear approximation, divide-and-conquer, phase approximation, Hilbert transform

3D SURFACE RECONSTRUCTION AND COMPARISON SYSTEM USED FOR MARKING LOCAL DEFECTS OF TESTED OBJECTS

Adrian CHIOREANU, Aurel VLAICU, Bogdan ORZA

Technical University of Cluj-Napoca

adrian.chioreanu@com.utcluj.ro, aurel.vlaicu@com.utcluj.ro, bogdan.oraza@com.utcluj.ro

Abstract: Nowadays automatic 3D acquisition systems allow building accurate models of real 3D objects in a cost- and time-effective manner. This technology was used in a particular application context: shape defects detection. Specific needs of this domain are: medium-high accuracy, reliability, and a short acquisition time. A low-cost 3D reconstruction and testing prototype system was designed, based on structured light which compares the reconstructed shape of the tested objects with the reconstructed shape of a reference object. The scanner architecture and the first results obtained by implementing a prototype used to mark local defects of tested objects are presented.

Key words: 3D reconstruction, quality testing, structured light, defects marking.

STUDY ON THE PERFORMANCE OF CODING-ASSISTED SWARM COMMUNICATIONS

Anghel BOTOŞ , Mihai P. ŞTEF, Aurel VLAICU

Technical University of Cluj-Napoca

15 C. Daicoviciu str., 400020 Cluj-Napoca, Romania, Tel: +40264401906, Anghel.Botos@com.utcluj.ro

Abstract: Swarm communications represent some of the main solutions proposed for large content distribution in the current and future data communication networks. One of the possible solutions to improve the performance of swarm communication is represented by the use of Digital Fountain and Network Coding techniques integrated in the data exchange between swarm peers. The paper proposes a comparative study of the non-coded and coding assisted swarm communications in different settings related to the amount of employed signaling, supersymbol size, supersymbol number, and number of initial seeds. The study is based on computer simulations performed in some particular network topology and the goal is to identify the settings of coding assisted swarm communications which ensure significant decrease of its content distribution time.

Key words: Content distribution, Digital Fountain, Network Coding, swarm communications.

PERFORMANCE ANALYSIS OF NETWORK CODING-BASED COOPERATION ALGORITHMS EMPLOYED IN CELLULAR NETWORKS

Mihai P. ŞTEF, Anghel BOTOŞ, Aurel VLAICU

Technical University of Cluj Napoca

15, Constantin Daicoviciu, Cluj Napoca, Romania,Tel. +40264401906 , Mihai.Stef@com.utcluj.ro

Abstract: The employment of the network coding, combined with distributed FEC coding, in cooperative transmission schemes leads to a more efficient use of the additional time-frequency resources required by cooperation, i.e. by allowing a single relay node to serve two or more user terminals. This paper proposes a low complexity cooperation algorithm which employs network and distributed channel coding techniques in a two sources – one relay node cooperation scheme for the uplink connection of a cooperative cellular network. It also, provides a description and an analysis of the “mother” algorithm, Separate Network and Channel Coding (SNCC). The performance of the proposed cooperation algorithm is evaluated in terms of BER and PER in several significant scenarios. The performance provided by this algorithm is compared to the performance of non-cooperative coded transmission and to the performance of the “mother” algorithm, the SNCC algorithm.

Key words: cooperative diversity, channel coding, network coding, turbo codes

TTS EXPERIMENTS: ROMANIAN PROSODY

Arpad Zsolt BODO^{*, **}, Gavril TODEREAN^*, Ovidiu BUZA^*

^*Technical University of Cluj-Napoca, Faculty of Electronics, Telecommunications and Information Technology;
^**Sprint Consulting Ltd.,Cluj-Napoca, Romania

zsolt.bodo@sprintconsulting.com

Abstract: In a text-to-speech synthesis system, prosody prediction and generation, is one of the most critical tasks. Prosody is composed by the melody, intensity and by the rhythm of speech. The current paper focuses on the Romanian intonation prediction and generation within our TTS system. Experimental results achieved by the development of different prosodic modules are presented in this work. The process is followed from text pre-processing, sentence type determination, through automatic labeling of sentences, till the labeling and transposing of the intonation curves. The creation and storage of relative intonation curves, as the developed different rule systems described in XML are also topic of this work.

Key words: Intonation; Melody; Labeling; Prosody; Sentence type; Text analysis; Intonation curve; XML rules.

VECTOR CONTROL OF INDUCTION MOTOR BASED SPACE VECTOR MODULATION

L. BOURAS M. KADJOUDJ

Batna University, Algeria, BP 336 Batna, email: kadjoudj_m@yahoo.fr

Abstract: It is well known that the vector control based on hysteresis regulators of induction machine presents less performance in term of current quality witch translated by strong ripples at steady state what increases the commutation losses in the inverter. For these reasons, we propose a new approach of FOC based on the SVM technique. Simulation results are shown to demonstrate the validity of the proposed methods.

Key words: Induction Motor, FOC, SVM, Hysteresis.

FUZZY LOGIC BASED DECISION MAKING FOR HYDROELECTRIC ENERGY GENERATION IN A CASCADED HYDROPOWERPLANTS

Gabriel OLTEAN*, Mihaela GORDAN*, Emilia ŞIPOŞ*, Eugen STĂNCEL**, Ovidiu DANCEA**

*Bases of Electronics Department, Technical University of Cluj-Napoca

26-28 G. Baritiu str., Cluj-Napoca, Romania, Tel: +40264401470; Fax: +40264591340;

**IPA SA Cifaat Cluj, Zorilor 15, Cluj-Napoca, Romania Tel: +40264-596155,

Gabriel.Oltean@bel.utcluj.ro

Abstract: Hydroelectric energy is a major source of renewable electricity in the world. The industry is continuously searching for ways to improve the efficiency and reliability with which it produces energy. A method based on subtractive clustering of historical data, to develop fuzzy rule-based systems for optimal hydroelectric energy generation allocation for a hydropowerplant is proposed in this paper. The applicability of this modeling approach is demonstrated by a study on the cascaded hydropowerplants on Somes River in Romania. The optimal planning of energy generation is determined on total demand of energy production for entire hydropowerplants cascade, water storage stage, and reservoir inflows. Two fuzzy systems, FEA1, encapsulating information only about the hydropowerplant under consideration, and FEA2, encapsulating information about all the cascaded hydropowerplants, are developed. Both fuzzy models was able to model, with good results, the optimal operation of the considered hydropowerplant, with a plus for FEA2 that provides more accurate results in the testing data set.

Keywords: hydroelectric energy generation, hydro power plant, fuzzy rule-based system, subtractive clustering.

Number 4/2008

DIGITAL IMPLEMENTATION OF ARTIFICIAL REVERBERATION ALGORITHMS

Irina DORNEAN, Marina ŢOPA, Botond Sandor KIREI - Faculty of Electronics, Telecommunications and Information Technology, Technical University of Cluj-Napoca , Str. G. Bariţiu nr. 26-28,400020 Cluj-Napoca, Romania, Tel: +40264401470; Fax: +40264591340 Irina.Dornean@bel.utcluj.ro

Abstract : The paper presents the digital implementation of signal processing algorithms that simulate natural concert hall reverberation. It deals with the complete artificial reverberators proposed by Schroeder, Moorer and Gardner. For each reverberation algorithm the implementation was done in two steps: 1. the algorithm is checked using a model in Matlab Simulink; 2. the Verilog code is written and tested. The results prove that the Verilog design is feasible and can be further developed for acoustic improvements of rooms.

Key Words: : artificial reverberators, FPGA

A FUNCTIONAL MODEL FOR A STANDALONE FINGERPRINT RECOGNITION SYSTEM

Liviu ANDRON, Toader MELINTE , Seektron SRL, andron@seektron.ro

Abstract: The paper describes a functional model for a standalone fingerprint recognition system, representing a minimum implementation to demonstrate the functionality of such system. For simplicity, the model uses only a fingerprint recognition module and a demonstration board with a PIC microcontroller. The development tools were that common used by the PIC microcontroller family.

Key Words: fingerprint recognition system, fingerprint recognition module, embedded system, microcontroller.

FEEDBACK CONTROL VS. INTEGRATED CONTROL.A CASE STUDY: VARIABLE VOLUME ROOM EXPERIMENTAL BENCHMARK

Adrian JOLDIŞ, Dorin ISOC, Ion GAZIUC, Aurelian IGNAT-COMAN - Technical University, Romania 400020, Cluj-Napoca str.C.Daicoviciu nr.15 , adrian.joldis@com.utcluj.ro, dorin.isoc@aut.utcluj.ro, ion.gaziuc@yahoo.com, aurelian.ignat@aut.utcluj

Abstract: Systems are in continuous diversification of their application domains and functioning specification requirements. Now, control systems’ development is mainly oriented towards completing of conventional feedback control with new techniques and design means. This work deals with integrated control problems compared to feedback control systems. The purpose is to extract defining characteristics of feedback and integrated control that emphasize the main differences between these two terms and manners to understand the control. Variable volume room experimental benchmark is introduced together by means a functional specification. Some design possibilities are introduced to demonstrate the general discussed aspects based on a real example.

Key words: integrated control, systems design, feedback control, experimental benchmark.

AN EXPERIMENTAL ARCHITECTURE FOR BASIC IPTV CONCEPTS IMPLEMENTATION AND TESTING

Radu ARSINTE - Technical University Cluj-Napoca, Tel: +40-264-595699, Str. Baritiu 26-28, Radu.Arsinte@com.utcluj.ro

Abstract: The paper describes basic concepts and a practical implementation of a simple architecture for IPTV content creation and distribution. The architecture is conceived to make possible extensive tests. Audio-video content is acquired using different conventional technologies: DVB-S, CATV Headend, video streaming servers. This experimental network is intended to be used for throughput, QoS and audio-video quality measurements. Some of the most relevant features and tests (still in progress) are described in the final part of the paper.

Key words: IPTV, Network, Audio-video streaming, Content management

BROADBAND POWER AMPLIFIER NONLINEARITY CANCELLATION IN OFDM SYSTEMS

Stefan WERNER, Fernando GREGORIO, Juan COUSSEAU, Jose FIGUEROA,, Risto WICHMAN - Helsinki University of Technology P.O. Box 3000, 02015 TKK, Finland, , Universidad Nacional del SurAv. Alem 1253, Bah´ıa Blanca, 8000 Argentina

Abstract: One drawback of OFDM systems is the high peak-to-average power ratio, which imposes strong requirements on the linearity of power amplifiers (PAs). Such linearity requirements translate into high back-off that results in low power efficiency. In order to improve power efficiency, a PA nonlinearity cancellation (PANC) technique is introduced which reduces the nonlinear distortion effects on the received signal. In order to deal with broadband high-power PA (HPA) distortion, the PANC technique employs aWiener-Hammerstein model. Simulation results show that good levels of distortion cancellation are possible for a system with a nonlinear HPA with memory.

Keywords: Orthogonal frequency-division multiplexing (OFDM), nonlinear distortion, power amplifier (PA) nonlinearities cancellation, Wiener-Hammerstein model.

MULTIPLE-INPUT ADAPTIVE COMBINER-EQUALIZER FOR WIRELESS COMMUNICATIONS

Ligia CREMENE Marcel CREMENE Nicolae CRISAN Tudor PALADE, Technical University of Cluj-Napoca, 15 Daicoviciu street, 0264-401914, Ligia.Cremene@com.utcluj.ro

Abstract: Receiver diversity is one of the most efficient techniques against fading and interference effects. MRC (Maximum Ratio Combining) was proven to ensure the highest diversity gain, but it is also the most complex compared to other combining techniques. In this paper we propose a multiple-input adaptive combiner-equalizer that provides better performance at lower complexity. The novelty of the solution lies in the unified combining-equalization approach - the two classical operations being performed simultaneously and not sequentially. A first set of simulations has shown that the performance of the proposed combiner-equalizer is superior to that of a classical MRC implementation.

Key words: Adaptive Equalization, Receiver Diversity, MRC (Maximum Ratio Combining).

THE IMPROVEMENT OF THE WAVELET ANALYSIS TECHNIQUES BY USING B-SPLINE FUNCTIONS FAMILY

Simina EMERICH - Communications Department, Technical University of Cluj-Napoca, G. Baritiu 26-28, 400027, Cluj-Napoca, Romania, Simina.Emerich@com.utcluj.ro

Abstract: The goal of this paper is to justify the use of fractional B-spline bases in several Wavelet Analysis Techniques. We are interested in better controlling the differentiation behavior of the wavelet. For that purpose, we propose an edge detector algorithm by using the wavelet transform local maxima, based on B-spline functions. Another task is to search the connection available between energetic analysis and the chosen type of wavelet family and to use the results for Glottal Closure Instants Estimation in Voiced Speech.

Key words: Wavelets, fractional B-splines, differentiator, energetic analysis

BROADBAND WIRELESS ACCESS AND MOBILITY SOLUTION USING IEEE 802.16: CONCEPTS AND ARCHITECTURE

Rebeca Maria COLDA , Tudor PALADE, Emanuel PUŞCHIŢĂ - Faculty of Electronics, Telecommunications and Information Technology, Communications Dept. , 26 G.Baritiu Street, 400027 Cluj-Napoca, Romania, E-mail rebeca_colda@yahoo.co.uk

Abstract: WiMAX (Worldwide Interoperability for Microwave Access) is a wireless broadband access solution, developed according with the IEEE 802.16 standard specifications with the purpose of delivering high speed radio access, most commonly Internet access, especially for those areas where a conventional solution, based on cable or DSL, proves to be ineffective. The early WiMAX solutions were based on IEEE 802.16-2004 and targeted fixed applications. In December 2005, the IEEE group completed and approved IFEE 802.16e-2005, an amendment to the IEEE 802.16-2004 standard that added mobility support.

Key words: WiMAX, IEEE 802.16-2004, IEEE 802.16e-2005, BS, SS.

PERFORMANCE ANALYSIS OF MIMO TECHNOLOGY IN MOBILE WIRELESS SYSTEMS

Ancuţa MOLDOVAN, Traian VILA, Tudor PALADE, Emanuel PUŞCHIŢǍ – Technical University of Cluj-Napoca,26-28 G. Bariţiu Street, 40027, Cluj-Napoca, Romania, phone:40264401914,e-mail:Ancuta.Moldovan@com.utcluj.ro

Abstract: The main goals in developing new wireless communication systems are increasing the transmission capacity and improving the spectrum efficiency. Space-time codes and spatial multiplexing codes exploit the richly scattered wireless channel by using multiple transmit and receive antennas in order to improve the reliability of data transfer and greatly increase the data transmission rates without additional radio resource requirements. Significant performance gain is achieved by varying some transmit and receive parameters.

Key words: MIMO, space-time coding, space division multiplexing

DESIGN OF AN INTELLIGENT SYSTEM FOR MONITORING AND ASSISTING OF NEOPLAZIC PATIENTS

Corneliu RUSU, Sergiu CADAR, Silviu CORBU, Lacrimioara GRAMA, Marius SIRBU - 1Universitatea Tehnica Cluj-Napoca, Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei Baritiu 26-28, Tel. +40 264 401804, Fax. +40 264 591340, E-mail: Corneliu.Rusu@bel.utcluj.ro, 2Institutul de Cercetari pentru Instrumentatie Analitica Cluj-Napoca Donath 67, Tel. +40 264 420590, Fax. +40 264 420667, E-mail: sergiu.cadar@icia.ro 3Universitatea din Oradea, Facultatea de Medicina Universitatii 1, Tel. +40 259 408105, Fax. +40 259 432789, E-mail: smcorbu.oncology@yahoo.com 4Universitatea Tehnica Cluj-Napoca, Facultatea de Electronica, Telecomunicatii si Tehnologia Informatiei Baritiu 26-28, Tel. +40 264 401804, Fax. +40 264 591340, E-mail: Lacrimioara.Grama@bel.utcluj.ro 5SC WS COMM SRL Cluj-Napoca, Republicii 107, Tel./Fax. +40 364 440120, E-mail: marius@wscomm.ro

Abstract: The aim of this work is to create an intelligent client-server structure through which the neoplazic persons that use the opioid medicine to be monitorized and assisted at home, and also to efficiently intervene to lend the essential assistance. The patient has at his/her disposal an interface which allows the transmission of some information regarding his/her healthiness through a reception server. This information is analyzed in accordance with some treatment criterions and protocols well regulated, and decisions for adjusting the doses of the opioid medicine are taken function of the intensity of the algic symptomatology.

Keywords: Intelligent client-server system, oncology, biometry, opioid medication.

Number 3/2008

ADVANCED FLEXIBLE ADAPTIVE FILTERING – TOWARDS STRUCTURE, TIME AND STATISTICAL AGILITY

Colin F.N. COWAN - ECIT, Queen’s University Belfast, Northern Ireland Science Park, Queen’s Island, Belfast BT3 9DT. Phone:+44 (0)28 9097 1879, Fax:+44 (0)289097 1702, Email: c.cowan@ecit.qub.ac.uk

Abstract: This paper considers the evolution of modern adaptive filtering in the context of applications in wireless communications. The main contribution is to introduce a common framework which potentially allows the adaptive system to include structure, e.g. number of coefficients, as one of the adaptable parameters. The proposed structure also allows for statistical variations to be taken into account in a highly time variant manor. Some examples are also cited to illustrate these features.

Key Words: Adaptive filters, structure adaptation, Kurtosis, time variation, equalization, echo cancellation.

SAFE PRE-PASS SOFTWARE BYPASSING FOR TRANSPORT TRIGGERED PROCESSORS

Pertti KELLOMAKI, Vladimir GUZMA, Jarmo TAKALA - Tampere University of Technology, Finland , P.O. Box 553, FIN-33101 Tampere, Finland Fax +358 3 3115 4561. Email {firstname.lastname}@tut.fi

Abstract: The Transport Triggered Architecture is an architectural style where the internal transport buses of a processor are exposed in the instruction set. Since software has full control over data transports, data can be directly transfered between functional units, an optimization known as software bypassing. Software bypassing can potentially reduce the need for general purpose registers, because temporary values can be kept in functional units. Taking advantage of the reduced register pressure requires software bypassing to be done before register allocation and scheduling. In this paper we analyze under which conditions software bypassing can be done on a Data Dependence Graph without compromising the schedulability of the graph.

Key Words: Triggered Architecture, Software, Bypassing

MULTY BINARY TURBO CODED WOFDM PERFORMANCE IN FLAT RAYLEIGH FADING CHANNELS

Marius OLTEAN, Maria KOVACI, Horia BALTA, Andrei CAMPEANU - Faculty of Electronics and Telecommunications, Timisoara, Romania Bd. V. Parvan, nr.2, Timisoara, Phone: 0256403307, email: marius.oltean@etc.upt.ro

Abstract: In this paper, the application of Multi Binary Turbo Codes (MBTCs) to two multicarrier modulation techniques used for transmission in the flat radio fading channel is studied. Thus, the performance of the coded versions of Orthogonal Frequency Division Multiplexing (OFDM) and of its wavelets based version (WOFDM) is evaluated under several simulation scenarios. These scenarios take into account the time variability of the radio channel, by the mean of the Doppler shift parameter. An important conclusion is that, under the assumptions made in this paper, WOFDM outperforms OFDM. By the other hand, this technique shows little influence on the choice of the wavelets mother used in the modulator.

Key words: Duo binary Turbo Codes, WOFDM, OFDM,  Flat Fading

A STUDY OF THE PERMUTATION SCHEMES USED IN THE MOBILE WIMAX

Horia BALTA¹, Daniel BOSNEAGU², Maria KOVACI¹, Marius OLTEAN ^{1,2 1} Electronics and Communications Faculty, Politehnica University, Bd. V. Parvan, Timisoara, 40256403307, (horia.balta, maria.kovaci, marius.oltean)@etc.upt.ro ²ALCATEL - LUCENT Timisoara

Abstract: With the goal of decreasing the interference at sub-carrier level, the allocation of sub-carrier frequencies in an OFDMA based system is selective. This selective allocation can be seen like a permutation of a frequency “sequence”. This paper proposes a new analyzing tool for the frequencies permutation used in WiMAX mobile communications: the distances spectrum (DS). This tool can offer a meaningful measure for these permutations, with respect to the most performing permutations used in turbo-codes, which, given their major importance, are strongly studied and developed.

Key words: permutations, sub-carrier frequency, interleaving distances spectrum, spreading degree.

WATERMARKING BASED ON THE HYPERANALYTIC WAVELET TRANSFORM

Corina NAFORNITA, Alexandru ISAR - Electronics and Communications Faculty, Politehnica University,

2 Bd. V. Parvan, Timisoara, 40256403307, (corina.nafornita, alexandru.isar)@etc.upt.ro

Abstract: In this paper we present a new technique for watermarking in the hyperanalytic wavelet domain. This has the advantage of better directional selectivity and shift invariance compared to the classical wavelet filter. The watermark is inserted into all levels of decomposition using a perceptual mask conceived by the authors. We compare this technique with two systems in the DWT domain, and show its superiority. We study the resistance of the three watermarking systems against various signal processing attacks. All three methods successfully detect the watermark. This leads to the conclusion that the Hyperanalytic Wavelet Transform (HWT) increases the payload and robustness.

Key words: HWT, watermarking, perceptual mask, capacity.

ON THE TUNING PERFORMANCE OF AN ACTIVE RF BANDPASS FILTER

Cristian ANDRIESEI, Liviu GORAŞ - “Gh. Asachi” Technical University, Iaşi 700506 Iasi, Bd. Carol I, No. 11, Phone: (+40) 232 270041, Fax: (+40) 232 217720, lgoras@etc.tuiasi.ro

Abstract: The paper describes a new principle of independent frequency and quality factor tuning suitable for simulated  inductors based active RF filters. The method makes use of two dc decoupled negative resistances in order to avoid frequency and quality factor inter–dependency. A differential architecture is studied and several considerations regarding the tuning capability and stability behavior are presented. The target application is a multi–standard active bandpass filter envisaging wireless transceivers.

Key words: simulated inductor, CMOS RF filters, negative resistance, independent tuning.

A ZIGBEE SOLUTION FOR TELEMEDICINE APPLICATIONS

Adriana N. SÎRBU, Victor-Andrei V.D. MAIORESCU, Ioan I.CLEJU - Faculty of Electronics & Telecommunications, Technical University “Gh. Asachi” Iaşi B-dul Carol I, no. 11, 700506 Iaşi, Romania, Phone +4-232213737/259,Fax+4-232217720,asirbu@etc.tuiasi.ro

Abstract: The paper addresses several aspects regarding wireless communications in telemedicine applications. Possible solutions and comparisons between different technologies are presented.  A ZigBee based implementation case study is commented.

Key words: telemedicine, wireless technologies, ZigBee, sensor network, wireless body area network.

MULTIMODAL BIOMETRIC SYSTEMS OVERVIEW

Eugen LUPU, Petre G. POP - Technical University of Cluj-Napoca phone: +40-264-401-266; fax: +40-264-556-244 Email: Eugen.Lupu@com.utcluj.ro

Abstract: Biometric systems allow automatic person recognition based on physical or behavioral features which belong to a certain person. Each biometric feature has its limits and no biometric system is perfect so unimodal biometric systems raise a variety of problems. To over fulfilling some of the mentioned inconvenient and limitations and to increase the level of security the multimodal biometric systems are used. This paper discusses the main features of the multimodal biometric system: architecture, level of fusion, methodology used for integrating the multiple verifiers and normalization techniques. The main applications of the multimodal biometric systems are also presented.

Key words: biometric, authentication, multimodal, security, access control, fusion. normalization

EXPLORING FINE PHONETIC DETAIL FOR ROMANIAN TEXT TO SPEECH SYNTHESIS

Mircea GIURGIU - Technical University of Cluj-Napoca, Telecommunications Department, 26 Baritiu Str., 400027 Cluj-Napoca, Romania, E-mail: Mircea.Giurgiu@com.utcluj.ro

Abstract: This paper presents several experimental results on the study of Fine Phonetic Detail (FPD) in order to create the basis of a computational model for prosody description in a system for Text To Speech (TTS) synthesis. Different manifestation levels of FPDs together with their importance for TTS are presented. The experiments reported here, mainly take into consideration the linguistic aspect of prosody in a qualitative and quantitative manner: the influence of the accent at word and sentence level, the intonation, the rhythm and the speech rate.

Key words: speech processing, fine phonetic details, prosody control, text to speech synthesis

THE ROLE OF PROGRAMMABLE DIGITAL SIGNAL PROCESSORS (DSP) FOR 3G MOBILE COMMUNICATION SYSTEMS

Sorin ZOICAN - Politehnica University of Bucharest , Bdul Iuliu Maniu nr. 1-3, Phone: +4021 402 48 03, Fax: +4021 316 96 32, Email: sorin@elcom.pub.ro

Abstract: This paper illustrated the role of Digital Signal Processors (DSP) for third generation mobile systems. The currently deployed wireless infrastructure supports the third generation of mobile communications comprised of many distinctly different standards. As a result, interoperability among these standards is nearly impossible with respect to the cellular base station.  Many solutions for base station or mobile station have been implemented over the years, and each solution required a combination of two components, ASICs (Application Specific Integrated Circuits), and DSPs (Digital Signal Processors). This two-chip solution partitions the processing tasks between the ASIC and DSP, respectively. Although this solution is functionally acceptable, its system cost and flexibility are not completely optimized. Global objectives and attributes that include worldwide roaming, universal connectivity, high data transmission rates, location service capability, and support for high-quality multimedia services are now required. The paper is organized as follows: the 3G requirements, advanced technologies that involve DSP, architecture examples and conclusions.  

Key words: Digital Signal Processors, 3G Mobile Communications Systems

CAMERA PHONE BASED BARCODE DECODING SYSTEM

Romulus TEREBES⁽¹⁾,Otmane LAHLOU^{(2) - (1)}The Technical University of Cluj-Napoca, Romania, 15 C. Daicoviciu Street,Cluj-Napoca, Romania, ⁽²⁾ENSEIRB, France 1 av. du docteur Schweitzer,33402, Talence cedex, France

Abstract: We propose a 1D barcode acquisition and decoding system based on the use of J2ME enabled mobile phones. The approach relies on image processing techniques to correct the distortions introduces by the acquisition device, segments the useful information, decodes it and subsequently sends it to a web server for further processing.

Key words: Image processing, 1D barcodes, Java 2 MicroEdition.

Number 2/2008

AUDIO SUSCEPTIBILITY OF THE BUCK CONVERTER IN CURRENT-MODE POWER STAGE

Costel PETREA - Technical University “Gh.Asachi” Iasi Carol I, no.11 , 700506, cpetrea@etc.tuiasi.ro

Abstract: For the Buck Converter operating in Current-Mode Power Stage, the subharmonic oscillations can be eliminated by adding an external ramp. This ramp leads to reaching the null value of the audio susceptibility. When the null value of the audio susceptibility is reached, the error signal phase is shifted with –180 degrees . The external ramp value chosen for the null value of the audio susceptibility does not always coincide with the value for eliminating the subharmonic oscillations. Our paper deals with the compromise in order to obtain a power supply with an audio susceptibility as close to the null value as possible, a fast transient response as well as a good stability.

Key words: Buck Converter, Audio susceptibility, subharmonic oscillations, external ramp.

A VISUAL TOOL FOR DNA REPEATS LOCALIZATION

Petre G. POP - Technical University, Cluj-Napoca, Comm. Dept.,E-mail:Petre.Pop@com.utcluj.ro

Abstract: The detection of tandem repeats is important in biology and medicine as it can be used for phylogenic studies and disease diagnosis. A major difficulty in identification of repeats arises from the fact that the repeat units can be either exact or imperfect, in tandem or dispersed, and of unspecified length. This paper presents results obtained by combining grey level spectrograms with a novel numerical representation to isolate position and length of tandem repeats (TRs) in DNA sequences.

Key words: Genomic Signal Processing, Fourier analysis, Spectrograms, Sequence Repeats.

PHASE UNWRAPPING ALGORITHMS IMPLEMENTED ON A SYMBIAN BASED MOBILE DEVICE

Carol RUS, Lacrimioara GRAMA, Andrei DUSLEAG, Corneliu RUSU - Technical University of Cluj-Napoca, Romania , Email: Lacrimioara.Grama@bel.utcluj.ro

Abstract: Phase unwrapping is a procedure that allows 3D representation for surfaces when the data is acquired using interferometry based techniques. An interferogram contains phase difference values wrapped onto a fixed range of angles 0-360 degrees. In order to compute surface heights and generate an elevation model, the interferogram have to be unwrapped. This paper presents two 2D phase unwrapping algorithms: the zig-zag approach and the least-squares method, and shows an implementation of them on a mobile device based on Symbian S60 platform. Also, filtering methods (i.e mean filter and vector filter) for preprocessing the interferogram are discussed and implemented. The implementation was tested using SAR (Synthetic Aperture Radar) interferograms. Based on the results, it can be concluded that mobile devices offer enough processing and graphical power and development options, in order to be a good choice to test some new signal processing algorithms.

Key words: Interferogram, DEM, Phase Unwrapping, Symbian, S60.

FOUR QUADRANT ANALOG CURRENT MODE MODULAR MULTIPLIER DESIGNED WITH DIFFERENTIAL AMPLIFIERS

Lorant Andras SZOLGA, Lelia FESTILA, Mihaela CIRLUGEA - Basis of Electronics Department, Faculty for Electronics and Telecommunications, Technical University of Cluj-Napoca,26. Baritiu Street, 400027, Romania,Tel/fax:0040-264-591340, lorant.szolga@bel.utcluj.ro

Abstract: In this paper we propose two and four quadrant analog current mode multipliers, implemented with bipolar differential amplifiers. The simplicity, low power consumption and high frequency operation recommend them for real time applications.

Key words: analog multilplier, hyperbolic tangent domain, FF-1functions

WAVELETS AS FEATURES FOR OBJECTS RECOGNITION

Anca APATEAN (DISCANT), Alexandrina ROGOZAN, Simina EMERICH, Abdelaziz BENSRHAIR- Tehnical University of Cluj-Napoca, Cluj-Napoca, Romania 26-28, G.Baritiu Street, RO-400027, Cluj-Napoca, Romania, Tel: +40 264 401 568, Fax: +40 264 591 340 {Anca.Apatean, Simina.Emerich}@com.utcluj.ro

Abstract: In this paper, we mainly concentrate on the recognition module of an object categorization  system. Two types of images, visible and infrared, are investigated in order to improve the objects detection and recognition process. Different types of mother wavelets (Haar, Daubechies, Coiflet, Symlet, Biorthogonal, or fractional causal, anti-causal, generalized and symmetric) are used to extract the wavelet coefficients which will constitute the feature vector. The obtained feature vector then will be fed to a KNN classifier, in order to classify the object in one of the possible object’s classes used in the training step.

Key words: object recognition, wavelets, feature extraction, KNN classifier.

A NOVEL COMBINING TECHNIQUE FOR ADAPTIVE ANTENNA ARRAY

Nicolae CRIŞAN, Ligia Chira CREMENE - Technical University of Cluj-Napoca, 15 Daicoviciu street, Nicolae.Crisan@com.utcluj.ro

Abstract: In the context of new high-data-rate wireless communications, multiple antenna systems are now taken into account early in the design phase. MIMO (Multiple Input Multiple Output) transmission schemes are still based on high redundancy algorithms. This paper proposes a new combining technique, OSC-SSBC (Orthogonal Space Combining – Space-Space Block Coding), and demonstrates that multiple antenna systems can significantly increase channel capacity (close to double), in LOS conditions, by implementing the OSC method at the receiver, on an adaptive antenna array. The block diagram and mathematics are presented and discussed, for a 2Tx-2Rx configuration.

Key words: space diversity, spatial multiplexing, beamforming and beam-steering, OSC – Orthogonal Space Combining, MRC – Maximum Ratio Combining, MIMO – Multiple-Input-Multiple-Output.

Number 1/2008

GERSHGORIN CIRCLES ASSOCIATED TO DOUBLE GRID SECOND ORDER CELLULAR NEURAL NETWORKS

Iolanda ALECSANDRESCU^* Liviu GORAS^*#

*Faculty of Electronics and Telecommunications, “Gh Asachi” Technical University, Iasi, Romania

#Institute for Computer Science, Iasi, Romania

Abstract: The stability of variable parameters double grid second order cell Cellular Neural Networks (CNN’s) linearized in the central linear part of the cell characteristic is investigated by means of Gershgorin’s theorem using spatial domain as well as spatial-frequency domain descriptions. It is shown that the stability margins towards the right-hand side of the complex  plane are identical within both approaches and are larger than expected according to simulations. A conjecture regarding the limits of the characteristic polynomials roots is made and verified through simulations.

Key words: Cellular Neural Networks, eigenvalues, Gershgorin circles.

SPECTRAL CHARACTERIZATION OF TWO FAMILIES OF FIBER OPTIC TRANSMISSION CODES

Nicolae Dumitru ALEXANDRU

“Gh. Asachi” Technical University of Iaşi, Romania, Bd. CAROL I No.11 IAŞI RO-700506, 40-232-213737 Ext.105, Fax: -40-232-217720, nalex@etc.tuiasi.ro

Abstract: Because of the advantages it offers, such as high bandwidth, electromagnetic interference immunity, light weight, etc, the optical fiber is replacing the classic coaxial or twisted pair links. Two families of fiber optic transmission codes are presented and investigated in terms of their spectral properties. The D.C. component carried by these codes affects the power budget of the signal and results in baseline wander that determines an increase of the bit error rate. However, they have the advantage of simple coding and decoding procedures and circuits, which are easy to implement.

Key words: Fiber optic codes, power spectral density, coding factor, autocorrelation function.

A FAST PARALLEL HUFFMAN DECODER FOR FPGA IMPLEMENTATION

Laurentiu ACASANDREI (*), Marius NEAG(**)

(*)Silicon Systems Transylvania SRL, Tel: +40258775181, acasandreilaurentiu@yahoo.com

(**)Technical University of Cluj-Napoca, Tel: +40264401470, Marius.Neag@bel.utcluj.ro

Abstract: The paper presents a novel algorithm and architecture for implementing a Huffman decoder. It starts with an overview of the basics, from the entropy coding and the way the Huffman coding is obtained, to the way a Huffman coder handles data and image components within the Jpeg standard. Then it briefly discusses the decoding procedures proposed by the ISO/IEC 10918-1(1993E) standard; due to their sequential nature, a decoder that simply implements these procedures requires several execution cycles to output one set of decoded data. A new decoding algorithm is then introduced, based on a parallel architecture that allows it to output a set of decoded data per each clock cycle. This approach was validated through actual implementation on an of-the-shelf FPGA; this not only demonstrates the proposed algorithm and architecture but also proves that it can operate at very high frequencies, up to 100MHz. A limitation of this implementation is the relatively large amount of hardware resources it requires.

Key words: Jpeg Standard, Fast Huffman Decoder, Image Acquisition and Processing, Parallel Architecture, FPGA

A VIRTUALLAB APPROACH FOR WIRELESS SENSOR MOTES AND WIRELESS SENSOR NETWORKS

Anghel V. CONŢIU, Adina ŢOPA, Vasile T. DĂDÂRLAT

Technical University of Cluj-Napoca, Str. Ctin Daicoviciu nr. 15, 400027 Cluj-Napoca, Romania E-mail: Vasile.Teodor.Dadarlat@cs.utcluj.ro

Abstract: The VirtualLab project was developed to fill the need of exploring the world of sensors, to make it available to younger students and to increase their interest in studying real sciences like physics, electronics or computer science. It is also a solution for low budget laboratories, making the motes available remotely.

Key words: Mote, Radio, Remote, Sensor, Wireless.

A MULE BASED STRATEGY FOR WIRELESS SENSOR MOTES TO REDUCE POWER CONSUMPTION

Adina ŢOPA, Anghel-Vasile CONŢIU, Vasile Teodor DĂDÂRLAT

Technical University of Cluj-Napoca, Str. C-tin Daicoviciu nr. 15, 400027 Cluj-Napoca, Romania E-mail: Vasile.Teodor.Dadarlat@cs.utcluj.ro

Abstract: The paper presents an application for wireless sensors, which focuses on reducing power consumption of the wireless sensor devices. The project uses a new technology, having a very big potential: motes called Tmote developed at Moteiv. The goal of this application is to investigate the use of the Tmote nodes as mules, to implement a power consuming strategy, so that the sensors deployed through the network will consume as little power as possible.

Key words: wireless sensor motes, power consumption strategy, data collection

UNANTICIPATED DYNAMIC ADAPTATION OF CONTEXT-AWARE SERVICES

Marcel CREMENE* Michel RIVEILL** Christian MARTEL***

*Universitatea Tehnica din Cluj-Napoca, Romania, cremene@com.utcluj.ro** Universite de Nice, Sophia-Antipolis, France, riveill@unice.fr***Universite de Savoie, Chambery, France, christian.martel@univ-savoie.fr

Abstract: Usually, for building context-aware services, the developer must anticipate all the possible contexts elements and their states: user preferences, physical resources, location, etc. This anticipation is required in order to specify service and context-specific adaptation rules, which are necessary for the adaptation management. Because of this, the adaptation rules are not reusable and the service cannot react to unanticipated context changes. In this paper, we propose a platform for dynamic and unanticipated adaptation of component-based services. Our solution is based on a knowledge representation describing the service and the context as a whole system. Based on this service-context representation, the adaptive platform is able to check the adequacy between the service and the context and to search for solutions if necessary. The difference between the classical approach and our approach is that we use only general rules. We have tested our architecture using a prototype that shows that a forum service may be adapted to the user language without using service and context-specific rules.

Key words: Context-aware services, Components, Knowledge representation, Adaptation rules

SEGMENTATION OF COLOR IMAGES USING A COMBINATION BETWEEN MARKOW RANDOM FIELDS AND GRAPHS

Stefan Gherbea (*), Aurel Vlaicu (**)

(*) C.S. Hidroelectrica S.A. – S.H. Cluj, Cluj-Napoca, 1 Taberei st., Tel. 0788202770 Fax:(040) 0264-427797 , e-mail Stefan.Gherbea@hidroelectrica.ro

(**) Technical University of Cluj-Napoca, 15. C.Daicoviciu str.Aurel.Vlaicu@com.utcluj.ro

Abstract: The goal of image segmentation is partitioning the images into homogeneous and interpretable regions. Image interpretation is part of scene understanding. It can be viewed as the process of giving meaning to a 2D image by identifying and labeling significant objects or segments in the image. For example, we may first segment an image and then interpret each segment as being a road, river, building etc.

Key words: MRF, Gibbs distribution, Simulated Annealing, Graph, MST, probability

MODELLING AND SIMULATION OF PHOTOVOLTAIC CELLS

Dorin PETREUŞ, Cristian FĂRCAŞ, Ionuţ CIOCAN

Technical University of Cluj-Napoca, Faculty of Electronics, Telecommunications and Information Technology,26-28 G. Bariţiu Street, Cluj-Napoca, Romania, Phone +40-264-401412, E-mail: Dorin.Petreuş@ael.utcluj.ro

Abstract: A photovoltaic cell converts the solar energy into the electrical energy by the photovoltaic effect. Solar cells are widely used in terrestrial and space applications. The photovoltaic cells must be operated at their maximum power point. The maximum power point varies with illumination, temperature, radiation dose and other ageing effects. In this paper, we present four models for a photovoltaic cell. Each method was evaluated and their strengths/weaknesses were identified. Two empirical models was modeled and simulated in Mathcad. The empirical models developed are validating through the comparison of the obtained characteristics with the ones given by the manufacturers of the PV panels.

Key words: photovoltaic (PV) cell, maximum power point (MPP), I-V curves, model.

Number 4/2007

EXTRACTION AND ANALYSIS OF DIURNAL FADE VARIABILITY AND SLOPE FROM SLANT PATH KA BAND RADIOMETER MEASUREMENTS

Ana-Maria Ersilia ANCA

Technical University of Cluj-Napoca, No.15, C. Daicoviciu Street, 400020 Cluj - Napoca, Romania, E-mail: anca_anamaria@yahoo.com

Abstract: The use of Ka-band and higher frequencies in satellite communication systems presents important advantages with respect to lower frequencies. However, the atmospheric-induced attenuation in these bands is substantial, and may lead to frequent outages that will compromise the availability and quality of service. Thus, the use of fade mitigation techniques, in order to compensate for excessive attenuation, will be in many cases unavoidable. The design and implementation of fade mitigation techniques require not only the knowledge of the inter-annual, seasonal and diurnal variability of long-term attenuation statistics, but also of the dynamic characteristics of attenuation, such as fade duration, inter-fade intervals and fade slope.

Keywords: attenuation, fade slope, radiometer, atmospheric remote sensing, cumulative distribution, probability density distribution

DIGITAL FLL DETECTOR FOR SATELLITE BEACON RECEIVERS

Ancuta MOLDOVAN, Tudor PALADE

Technical University of Cluj-Napoca, No.15, C. Daicoviciu Street, 400020 Cluj - Napoca, Romania

No.26-28, Baritiu Street, E-mail: Ancuta.Moldovan@com.utcluj.ro, Tudor.Palade@com.utcluj.ro

Abstract: The paper addresses the design, implementation and test of a beacon receiver coherent detector by using a DSP based software controlled frequency locked loop. The system is built around a user developed card, using fast ADC’s and dedicated signal processing programmable chips, interfaced with a DSP kit. The DSP implements the loop filter by programming in real time a numerically controlled oscillator. The preliminary results are presented and discussed.

Key words: digital receiver, frequency locked loop, loop filter, frequency discriminator, numerically controlled oscillator

FRAME BY FRAME PHONEME CLASSIFICATION USING MLP

József DOMOKOS¹ , Gavril TODEREAN²

¹Sapientia - Hungarian University of Transylvania, Faculty of Technical and Human Sciences, Tîrgu-Mureş , domi@ms.sapientia.ro

²Technical University of Cluj-Napoca, Faculty of Electronics, Telecommunications and Information Technology, toderean@pro3soft.ro

Abstract: In this paper, there are presented some practical experiments for continuous speech frame-by-frame phoneme classification using MLP neural networks. We used to train and test our software application, the TIMIT continuous speech database, and the OASIS Numbers database. In the experiments, we tried to classify all the existing 61 phonemes together, from TIMIT dictionary and the 32 phonemes from OASIS Numbers database. We also used different MLP configurations to compare the achieved results. For classification, we used 13 MFCC coefficients and their first and second order derivatives (delta parameters) extracted from speech signal using a Matlab® based feature extractor software application.

Key words: phoneme classification, MFCC, delta, double delta, MLP, continuous speech recognition, TIMIT, OASIS Numbers;

FPGA IMPLEMENTATION OF THE ADAPTIVE LEAST MEAN SQUARE ALGORITHM

Irina DORNEAN, Marina TOPA, Botond Sandor KIREI, Erwin SZOPOS

Bases of Electronics Department, Technical University of Cluj-Napoca, Romania

26-28 G. Baritiu str., Cluj-Napoca, Romania, Tel: +40264401470; Fax: +40264591340 Irina.Dornean@bel.utcluj.ro

Abstract: The paper presents a digital implementation of the adaptive Least Mean Square (LMS) algorithm. The algorithm was chosen due to its robustness and simplicity. The envisaged application is the identification of an unknown system. The implementation was done in two steps: first the algorithm is checked using a model in Matlab Simulink and then the Verilog code is written and tested. The results prove the theory that while the error converges to a minimum value, the output and the desired signal are comparable in shape and values. The application enables further developments and researches, creating an opportunity for automation and prediction.

Keywords: LMS, Simulink, FPGA

ESTIMATION RELIABILITY OF MICROARRAY DATA USING HIGH ORDER STATISTICS

R. MALUTAN^1,2, P. GOMEZ VILDA², M. BORDA¹, F. DIAZ²

¹Universitatea Technica Cluj Napoca, Geroge Baritiu nº 26-28, 400027, Cluj Napoca, Romania

²Universidad Politecnica de Madrid, Campus de Montegancedo, s/n, 28660, Boadilla del Monte, Spain

raul.malutan@com.utcluj.ro

Abstract: Microarray technology posses some interesting problems under the point of view of Genomic Signal Processing, as test probes express themselves in rather different patterns, not showing proportional expression levels for most of the segment pairs, as it would be expected. These cases may be influenced by unexpected hybridization dynamics, and are worth of being studied with a double objective: gain insight into hybridization dynamics in microarrays, and to improve microarray production and processing. Two methods are proposed: modeling the dynamics of expression dynamics and isolating gene expressions showing unexpected behavior to proceed in their further classification and study.

Key words: microarray, hybridization, orthogonality, reliability.

ANALYSIS OF HIGH POWER MEMS VARACTORS FOR RF AND MICROWAVES INTEGRATED CIRCUITS

Nicolae CRIŞAN, Ligia CREMENE

Technical University of Cluj-Napoca, 26-28, Baritiu street, phone: 40264401914, crisan@com.utcluj.ro, ligia.cremene@com.utcluj.ro

Abstract: This paper focuses on designing, modelling and analysis of a MEMS capacitive cantilever switch using EM-CAD simulators. Capacitive MEMS have many applications in adaptive filters and smart antennas. EM-CAD simulators can help determine the S dispersion parameters for MEMS devices. Modelling MEMS switches by S-parameters, enables the usage of MEMS directly into electronic-circuit-oriented simulators (non - EM simulators), based on S-parameter measurements. The proposed method enables emulation of MEMS devices in any

circuit-oriented CAD analyzer that uses quadripol models instead of MEMS component models. After importing the S-parameter files from one simulator to the other, the analysis of the most complex circuits (MEMS together with classic electronic components) becomes possible. This analysis remains valid for the frequency band in which the MEMS device has been analyzed. Adaptability of the resulted circuit is the main achievement of the process.

Key words: MEMS – Micro-Electro-Mechanical Systems, EMF – Electromagnetic Field, FEM – Finite Element Method

MODEL-BASED DESIGN AND FPGA IMPLEMENTATION OF CONTROL SYSTEMS

Gabriel OLTEAN*, Botond Sandor KIREI*, Irina DORNEAN*, Ioana OLTEAN**

* Bases of Electronics Department, Technical University of Cluj-Napoca 26-28 G. Baritiu str., Cluj-Napoca, Romania, Tel: +40264401470; Fax: +40264591340; Gabriel.Oltean@bel.utcluj.ro

** Grup Şcolar Electrotehnic „Edmond Nicolau”, Cluj-Napoca

Abstract : FPGAs have become a very promising solution for the realization of digital control systems. In this paper an efficient model-based design methodology for FPGA implementation of a control system is presented. The Matlab/Simulink environment is used here for modeling, simulation and tuning a temperature control system based on PID controller. Verilog HDL language describes the digital control system to be implemented on a FPGA development board. Results prove that the proposed methodology shortens the design cycle, because the whole system can be fully simulated and adjusted before its final design and implementation.

Keywords: PID controller, Verilog, FPGA

METHODS FOR SINGING VOICE IDENTIFICATION USING ENERGY COEFFICIENTS AS FEATURES

Annamaria MESAROS, Simina MOLDOVAN

Technical University of Cluj-Napoca, ROMANIA, G. Baritiu 26, RO-40027

Abstract: The problem of singer identification becomes a specific point of interest in themusical signal analysis field. This paper describes two energy representations of the voice signal and tests their efficiency in singing voice identification. The first set of energy features consists in the Mel-scale energies of 14 frequency bands, covering the whole frequency spectrum of the signal. The second energy representation is obtained by wavelet decomposition of the voice signal. The wavelet and scaling filters for the decomposition are derived from fractional B-spline functions. The wavelet decomposition is done hierarchically, into 14 bands, with octave-band filters, taking into account the specific frequencies of the formants. Both energy representations are tested for singing voice identification on the training set and on unknown data.

Number 3/2007

IP CAMERA SURVEILLANCE SYSTEM WITH AUTOMATED RECORDING

Mihai ROMANCA, Iuliu SZEKELY, Sorin COCORADA, Iulia GRAMA

Transilvania University of Brasov, 29 Eroilor, Romania, Tel./Fax: 0268 478705, romanca@unitbv.ro

Abstract: In this article we present the results obtained at the installation and configuration of a video surveillance system for controlling the access in a building. The system uses an IP video camera (NC 1200) connected at a building LAN. The IP camera used allows the visualisation of images by Internet connection but, for recording images, admits only manual command from the human operator that supervises the entrance. The camera has embedded the function of sending an instant picture by e-mail or on a FTP server if the system disposes any of these two facilities. For this reason we created an application that automatically starts recording images, when a motion is detected in the supervised space. The application has the advantage of saving the image frames directly on the monitoring computer and eliminates the constraint to have an online server (FTP or e-mail) and also that permits no modification of the camera firmware, being installed only on the monitoring computer. We report here some preliminary results, with only one surveillance camera, but the system will be extended to several ones. We illustrate the advantage of using a cheap IP camera combined with the original application for entrance surveillance.

Keywords: intelligent building, IP camera surveillance, real-time, intelligent visual surveillance

MONITORING LOW-RATE WIRELESS PERSONAL AREA NETWORKS USING SNMP

Cristian M. VANCEA, Virgil DOBROTA

Technical University of Cluj Napoca, Communications Department,

George Baritiu 26-28, 400027 Cluj-Napoca, Romania, Tel: 40-264-401264, Fax: 40-264-597083

E-mail: {Mihai.Vancea, Virgil.Dobrota}@com.utcluj.ro

Abstract: This paper presents a practical approach for enabling Simple Network Management Protocol for devices using IEEE 802.15.4 standard. This work is focused on providing a system that can be used for management of low-rate wireless personal area network equipment.

Key words: embedded systems, network management, Personal Area Network, SNMP

EVALUATION OF QoS PARAMETERS FOR IPTV

Ancuta Sanda BUZILA, Gabriel LAZAR, Tudor BLAGA, Virgil DOBROTA

Technical University of Cluj Napoca, Communications Department

George Baritiu 26-28, 400027 Cluj-Napoca, Romania, Tel: 40-264-401264, Fax: 40-264-597083

E-mails: anca_buzila@yahoo.com, {gabriel.lazar,tudor.blaga,virgil.dobrota}@com.utcluj.ro

Abstract: This paper describes in details the IPTV system, together with its implementation methods and the involved protocols. Furthermore, measurement methods of QoS parameters are analyzed, discussing a practical application for evaluation of IPTV traffic parameters. The following components are taken into account: bandwidth, one-way delay, inter-packet jitter, packet loss, number of duplicated packets, out-of-order packets and corrupted packets. In addition, two QoS parameters of importance for VoD are measured: START delay and PAUSE/RESUME delays. The implementation of this program opens the possibility of measuring the transmission parameters that influence QoS, with the purpose of offering a way to evaluate and control the services delivered by open-standards IPTV providers.

Key words: IPTV, measurements, QoS, XML

MULTICAST vs. UNICAST TRANSMISSIONS FOR WIRELESS IP CAMERA SURVEILLANCE SYSTEMS

Sorin COCORADĂ

University Transilvania of Brasov, 29 Eroilor, Romania, Tel./Fax: 0268 478705, sorin.cocorada@unitbv.ro

Abstract: This paper presents the results obtained at the installation, configuration and optimization of a wireless IP video surveillance system. Because of the cheap and insufficient hardware resources, the WVC54GC camera permits only a very limited number of HTTP over TCP unicast streams. Multicasting at the data link layer is a more efficient way for sending data to a group of receivers. Some possible solutions for overcoming the above limitation are presented using additional hardware and software. An analysis of their performance is presented using network monitoring tools, together with a discussion. Results have shown that there are several alternatives to efficiently provide a video stream to the end users.

Key words: wireless IP camera, unicast, multicast, IEEE 802.11

ASPECTS OF ENTERTAINMENT DISTRIBUTION IN AN INTELLIGENT HOME ENVIRONMENT

Radu ARSINTE

Technical University Cluj-Napoca, Tel: +40-264-595699, Str. Baritiu 26-28, Radu.Arsinte@com.utcluj.ro

Abstract: The paper presents an implementation and tests of a simple home entertainment distribution architecture (server + multiple clients) implemented using two conventional cabling architectures: CATV coaxial cable and conventional Ethernet. This architecture is created taking into account the “Home gateway” concept present in most attempts to solve the problem of the “Intelligent home”. A short presentation of the experimental is given with an investigation of the main performances obtained using this architecture. The experiments revealed that this simple solution makes possible to have entertainment and data services with performances close to traditional data services in a cost-effective architecture.

Key words: Home network, Streaming, Ethernet, Home Gateway

SELECTIVE DISTANCE DETECTING AND LOCATING SYSTEM

Gheorghe MORARIU, Marian ALEXANDRU, Adrian MAILAT

Transilvania University, Brasov, Romania 1 – 3 Politehnicii str., Phone/Fax +40268478705

gmorariu@vega.unitbv.ro, alexandrum@vega.unitbv.ro

Abstract: The goal of this paper is to present a selective distance detecting and locating device capable of determining the position of a fixed or moving target situated inside of a monitored area of given width placed at a certain distance from the transmitter/receiver antenna. The locator unit performs both the location and ranging function and simultaneously identifies the target status (mobile/immobile) and nature (biological/non-biological).

Key words: locating system, ultrasound, remote control

REMOTE TEMPERATURE RECORDING USING BLUETOOTH TECHNOLOGY

Marian ALEXANDRU, Mihai ROMANCA, Petre OGRUTAN

Transilvania University, 1 – 3 Politehnicii Str Brasov, Romania Tel/Fax +40268478705,

alexandrum@vega.unitbv.ro; romanca@unitbv.ro

Abstract: The past decade has seen significant advancement in the field of consumer electronics. Various “intelligent” appliances such as cellular phones, air-conditioners, home security devices, indoors localization, etc. are set to realize the concept of a smart home or building. A wireless home network that does not incur additional costs of wiring would be desirable. Bluetooth technology, which has emerged in late 1990s, is an ideal solution for this purpose. This paper describes an application of Bluetooth technology in home or industrial automation networking environment. It proposes a network, which contains a remote temperature sensor connected to a microcontroller, which controls, also, the Bluetooth module transmission and a computer having internet access, connected via USB to a Bluetooth module. In this way, the sensor data are collected and processed by the microcontroller, transmitted via Bluetooth to a fixed or mobile computer and published on a web page in order to be accessible for a remote user.

Key words: Bluetooth, smart building, temperature recording

A SYSTEM FOR BUILDING AUTOMATION SUPPLIED FROM A SOLAR PANEL

Dorin PETREUS, Niculaie PALAGHITA, Zoltan JUHOS

Faculty of Electronics, Telecommunications and Information Technology Technical University of Cluj-Napoca, Cluj-Napoca, Romania

Dorin.Petreus@ael.utcluj.ro

Abstract: This paper presents a solar power based scalable automation module designed for sensor/actuator interfacing and communication in intelligent buildings. The system was designed based on a number of modules which are connected together. This gives to the system more flexibility. A complete system (hardware and software) was implemented.

Key words- intelligent building; photovoltaic panel; battery powered; FSK modem.

OPEN SYSTEMS IN BUILDING MANAGEMET: LONWORKS vs. BACNET

Tudor SAMUILĂ, Bogdan ORZA, Aurel VLAICU

Technical University of Cluj-Napoca 15 C. Daicoviciu Street, 400020 Cluj-Napoca, Romania

Email: Tudor.Samuila@com.utcluj.ro

Abstract: The LonWorks and BACnet technologies gained widespread application and are the best choice as the leading open system

technologies. They have distinguished above the rest with a flexible architecture focused on meeting the growing requirements of building automation. Despite their achievements, LonWorks and BACnet have very little in common. They have different origins, different network architectures, different hardware and software requirements, and each has a core group of users. A comparison relevant to building automation should focus on market presence and solution approach. A market presence comparison is an indication of user and manufacturer acceptance through the number of user organizations and product availability. A solution approach comparison illustrates the differences and implementation issues to consider when evaluating a solution.

Key words: LonWorks, BACNet, building management, open systems, comparison

EMBEDDED WEB-SERVERS FOR REMOTE CONTROL IN DOMOTICS

Florin SANDU ⁽¹⁾ Daniel IOLU ⁽²⁾

⁽¹⁾ "Transilvania" University - Bd Eroilor nr. 29A, Brasov–Romania, phone/fax +40268478705, sandu@ unitbv.ro

⁽²⁾ Siemens Program and System Engineering, Bd Kogalniceanu nr.21, Brasov-Romania,

phone +40268409019, fax +40268409221, daniel.iolu@siemens.com

Abstract: In the frame of the CEEX –60- II03 INFOSOC contract 60- II03 – COMODICI, "Remote Control and Monitoring of Intelligent Buildings", the authors accomplished device enablement and device networking by embedded web-servers with serial tunneling. Their focus is on domotic devices but other appliances (remote testing in communications and remote health monitoring) are also mentioned

Key words: Domotics, device servers, serial tunneling, remote switching

A MUTISENSOR GPRS-BASED SECURITY SYSTEM FOR INTELLIGENT BUILDING

Petre OGRUTAN, Mihai ROMANCA, Csaba-Zoltán KERTÉSZ

TRANSILVANIA University of BRASOV, Department of Electronics and Computers Postavarului 3 ,tel/fax +40-268478705

ogrutan@vega.unitbv.ro, romanca@vega.unitbv.ro csaba.kertesz@vega.unitbv.ro

Abstract: In this work we present a security system collecting data from detectors for carbon monoxide, flammable gas, smoke, radon and from an access control system based on fingerprint recognition, and sending warnings through a GPRS link. The warnings are sent over the Internet is the concentration of toxic gases or smoke increases over a certain level or an unauthorized access is repeated several times. The transmitted data contains information about the type of danger situation and the location of the system determined by a GPS receiver.

Key words: Intelligent building, GPRS transmission, embedded system, Radon detector

REDUNDANCY FOR THE SECURITY SYSTEMS IN A SMART BUILDING USING INTERNET (WEB) AND GSM (SMS) TECHNOLOGIES

Mugur MOCOFAN, Radu VASIU, Mircea ABUCEANU

Politehnica University of Timisoara, Electronics and Telecommunications Faculty

Bd. Vasile Parvan, Nr. 2, Timisoara, Tel: +40 256 403319, Fax: + 40 256 403300
mugur@cm.upt.ro radu@cm.upt.ro mircea@multimediadesign.ro

Abstract: Security is a problem at multiple levels and for this reason we create an isolated, parallel network to control the smart buildings using the SMS technologies.

Key words: Smart buildings, SMS server, GSM.

SCENERIES CONTROL FOR SMART BUILDINGS USING RELATIONAL DATABASES

Muguras MOCOFAN, Radu VASIU, Iulia RADU

Politehnica University of Timisoara, Electronics and Telecommunications Faculty

Bd. Vasile Parvan, Nr. 2, Timisoara, Tel: +40 256 403319, Fax: + 40 256 403300
mugur@cm.upt.ro radu@cm.upt.ro jyar_33@yahoo.com

Abstract: The modernization of the buildings with the most performing technologies starts to grow more and more, and like a consequence, many people appeal to this technique, to leave in a more safety house, and why not, more comfortable. We propose a relational database for controlling the sceneries of smart buildings. The sceneries include all the settings for the house (lights, temperature and music) in a special case, for example “romantic dinner”.

Key words: Databases, Smart buildings, Sceneries.

Number 2/2007

STUDY OF A HYBRID - ANALOG TV AND ETHERNET- HOME DATA LINK USING A COAXIAL CABLE

Radu ARSINTE

Technical University Cluj-Napoca , Tel: +40-264-595699, Str. Baritiu 26-28, Radu.Arsinte@com.utcluj.ro

Abstract: The paper presents an implementation and compatibility tests of a simple home network implemented in a non-conventional manner using a CATV coaxial cable. Reusing the cable, normally designated to supply RF modulated TV signals from cable TV networks, makes possible to add data services as well. A short presentation of the technology is given with an investigation of the main performances obtained using this technique. The measurements revealed that this simple solution makes possible to have both TV and data services with performances close to traditional home data services: cable modems or ADSL, with minimal investments. This technology keeps also open the possibility for future improvements of the network: DVB-C or Data via Cable Modems.

Key words: Hybrid TV Network, Home network, Coaxial Cable, Ethernet

WEB ANALYTICS: A SHORT OVERVIEW (I)

Petre G. POP

Technical University, Cluj-Napoca, Comm. Dept., E-mail:Petre.Pop@com.utcluj.ro

Abstract: Web analytics is the measurement of the behavior of visitors to a website to assure its performance, gain insights into the needs and wants of users' of the site, and identify areas that can be optimized. In a commercial context, it especially refers to the measurement of which aspects of the website work towards the business objectives; for example, which landing pages encourage people to make a purchase. Many different vendors provide web analytics software and services. The purpose of this paper is to present the technical aspects of web analytical methods, then to survey some of these techniques and how they are currently being applied.

Key words: Logfile, Page Tracking, Cookies, Tags, Web Metrics.

5GHz INDOOR AND OUTDOOR MEASUREMENTS

Ligia CREMENE, Nicolae CRIŞAN, Tudor PALADE

Technical University of Cluj-Napoca,Baritiu 25-26 , Cluj-Napoca, phone: 40264401404, Ligia.Cremene@com.utcluj.ro

Abstract – We have tested an 802.11a PTP single-user link for both indoor and outdoor scenarios. We have tried to establish the optimum positioning of the 802.11a WLAN access point at one floor of an office building, observing the influence of people moving around, crowding certain rooms at certain moments of the day, and of course the influence of structure materials. Significant improvements in SNR levels have been noticed when changing the antenna type and modifying the position of the access point. We were thus able to extend the wireless access to other buildings, for LoS (Line-of-Sight) scenarios, and scarce out-of-leaf vegetation.

Key words: 802.11a WLAN, 5GHz measurements, optimum positioning, indoor and outdoor testing.

USING ADVANCED EM-CAD PROGRAMS TO ESTIMATE SPECIFIC ABSORBTION RATE OF THE HUMAN BODY

Nicolae CRIŞAN

Technical University of Cluj-Napoca,Baritiu 25-26, Cluj-Napoca , phone: 40264401404, crisan@com.utcluj.ro

Abstract: In order to prevent adverse health effect of the electromagnetic fields (EM) this article proposes one of the low cost and effective method to simulate and diminish the SAR (Specific Absorption Rate) by means of CAD modelers, taking into account the RF power transmitted and the antenna for a radio device before its hardware implementation. Especially, due to the rapid growth of mobile terminals in the last few years there is a growing concern about possible adverse effect of radio radiation from such devices that usually work closely by the human brain. There are already some reports describing powerful methods for measuring partial body absorption rate associated with the mobile phone terminals. The standardization process is near completed by the Telecommunications Technology Council which has taken this great responsibility.

Key words: SAR –Specific absorption rate, EM – Electromagnetic, DUT – Device under test, Voxel (3D-point)

ACOUSTIC DATABASE FOR ROMANIAN TTS SYNTHESIS. DESIGN AND REALISATION RESULTS I.

Árpád Zsolt BODÓ, Ovidiu BUZA, Prof. Gavril TODEREAN

Technical University of Cluj-Napoca, Faculty of Electronics and Telecommunications zsolt.bodo@gmail.com; ovidiu.buza@cs.utcluj.ro; toderean@pro3soft.ro

Abstract: The current paper presents the general design and partial realisation of a diphone database for Romanian concatenative text-to-speech synthesis. The design of a database and the planning of its realisation are presented in detail. The basis for the decisions, the aspects that need to be considered during the design, the rules elaborated – for e.g. the constructions of senseless words – are focused as well. The steps of realisation are shown theoretically and by practical hints too. However the database is not completely finished, the accomplished experiences during its development are shared by this paper.

Key words: Speech synthesis, Diphone, Database, Intrinsic prosodic parameters, Intonation, Pitchmarking, Senseless words, DB element processing, Monotone, Design checklist, Carrier text, Recording, Extraction, Automation.

REALISATION RESULTS OF A SPEECH SYNTHESIS DEVELOPMENT ENVIRONMENT

Árpád Zsolt BODÓ, Ovidiu BUZA, Prof. Gavril TODEREAN

Technical University of Cluj-Napoca, Faculty of Electronics and Telecommunications zsolt.bodo@gmail.com; ovidiu.buza@cs.utcluj.ro; toderean@pro3soft.ro;

Abstract: The development of a text-to-speech synthesis system is a complex process that is elaborated in several fields like: speech signal processing, prosody prediction and generation, synthesis techniques/engines, database construction, etc. Each of these domains, during their research and development phase, requires a toolset. The need for this is multiple: some times intermediate results are required to be visualised, some times external (manual) interaction to the system helps the researcher’s work. The current paper shows a collection of these kinds of tools, which finally form a development environment. This framework is built around a general voice signal editor freeware software, but the TTS specific tools and graphical user interfaces are the result of an own development. The main fields detailed below are: the PSOLA synthesis technique development environment, the diphone database processing environment, the speech signal processing toolset, some prosody modification related issues and intonation curve computation algorithm.

Key words: TTS development environment/framework, Toolset , Synthesis technique, Waveform, Intonation curve, Pithmarking, Prosody manipulation, Pitch descriptor, Prosodic descriptor, Temporal structure, Speech signal processing, Waveform editing.

FPGA IMPLEMENTATION OF PWM MODULES

Bogdan Stefan MEREUTA¹, Mihai LUCANU², Tecla Castelia GORAS³

¹ Technical University Iasi, Faculty of Electronics and Telecommunications, Blvd. Copou No. 11, 6600, Iasi, Romania, +40740368957, bmereuta@etc.tuiasi.ro

^{2, 3} Technical University Iasi, Faculty of Electronics and Telecommunications, Blvd. Copou No. 11, 6600, Iasi, Romania

Abstract: This paper presents a new method of PWM implementation with FPGA. Most FPGAs contain DSP blocks which minimize the die’s logic area and improve the PWM speed. The correct operation of the PWM module was verified by simulation.

ALGORITHM FOR DETECTING INTERSECTION POINTS BASED ON SWEEP LINE, WHEN THE SEARCH SPACE CONTAINS BOTH SEGMENTS AND ARCS

Aurel VLAICU¹, Stefan GHERBEA²

¹Technical University of Cluj-Napoca, e-mail Aurel.Vlaicu@com.utcluj.ro

²C.S. Hidroelectrica S.A.–S.H. Cluj, Cluj-Napoca, Stefan.Gherbea@hidroelectrica.ro

Abstract: The problem of the intersection point bet,een segments is very important in computer graphics. When displaying objects on 2 dimensional devices, intersecting sections should be eliminated, in order to enhance realism or to optimize the visualization. For example when a vector image is large and we need to view only a little portion from it, thehidden portion of the image should be eliminated. In 2002 Susa Hert – Kurt Mehlhorn developed a generalized algorithm for detecting intersection between conics arcs, based on sweep line. We propose a particularized version of the algorithm, for segments and arcs and a pseudo – code will be proposed. Based on this algorithm, an optimization for polyline outline structures was realized.

Key words: Arcs, segments, sweep line ,graphics algorithm, C++

Number 1/2007

ON THE PROPERTIES OF SOME PARTICULAR DATA SEQUENCES USED IN UWB-PPM SYSTEMS

Tudor DURNEA

''Gh. Asachi" Technical University of lasi. Faculty of Electronics and Telecommunications. Carol I avenue, nr. 11. RO-700506. e-rnail: dtudor@etc.tuiasi.ro

Abstract: The initial UWB systems based on impulses tried to implement PPM - type modulations in order to achieve maximum benefit from available large bandwidth. The UWB-PPM systems were noted to generate large interference to narrowband systems operating in the same band. The cause of this interference is the spectrum generated by the PPM modulation as it is known to concentrate high amounts of energy at discrete frequencies. There is no complete formula for the spectrum of the PPM signals for any symbol probabilities and any number of modulation bits. We present some particular properties of PPM symbols as we need them to evaluate their spectrum in order to successfully implement UWB-PPM systems.

Key words: UWB, PPM, Discrete Spectrum Components, Diff.

CONTENT BASED MEDICAL IMAGE RETRIEVAL USING ORACLE INTERMEDIA

Ligia CHIOREAN, Aron SIPOS, Mircea-Florin VAIDA

Technical University of Cluj-Napoca, Baritiu Street no. 26, 400027, Cluj-Napoca, Romania E-mails: Chiorean.Ligia@com.utcluj.ro, siposa@yahoo.com, Mircea.Vaida@com.utcluj.ro

Abstract- Oracle database offers the facility of searching and retrieving content-based multimedia objects such as audio, video, image or electronic documents, after a signature. There are different methods for signature generation for each specified object. The content-based image retrieval (CBIR) in Oracle may be realized on a linear search and comparison of the signatures using different parameters, or by image indexing, which are methods available in Enterprise Edition of Oracle Database. medBase is a dedicated application that uses Oracle interMedia for CBIR. Oracle has the possibility to integrate Java classes that offers more flexibility to a programmer in generating and processing the database objects. The chosen technology implemented in this paper is based on JSP, which is capable of realizing distributed web applications, and it can directly access the Java classes and methods offered by Oracle. The dedicated application was tested using different types of medical images stored in an Oracle database.

Key words: Content-based retrieving, multimedia database, Oracle interMedia

AN INVESTIGATION OF ISI AND ICI PROPERTIES FOR A FAMILY OF OFFSET RAMP IMPROVED NYQUIST FILTERS

Ligia Alexandra ONOFREI(*), Nicolae Dumitru ALEXANDRU(**)

(*)"Stefan eel Mare" University of Suceava, str. Universitafii no. 13, RO-720225, Suceava, onofreial@eed.usv.ro,

(**)"Gh. Asachi" Technical University oflasi,, Bd. Carol 1, no 11, RO-700506 Iasi, nalex@etc.tuiasi.ro

Abstract: We proposed a family of new Nyquist pulses based on an offset ramp method and investigated its performances in terms of ISI error probability. These pulses proposed and studied are employed for OFDM use, to reduce the sensitivity of OFDM systems to frequency offset. The results presented in this paper equal or outperform the recently found pulses in terms of intercarrier interference (ICI) power.

Key words: intersimbol-interference (ISI), intercarrier-interference (ICI), frequency offset

EXPERIMENTAL PERFORMANCE DETERMINATION OF END SYSTEM MULTICAST AND HYPERCAST

Tudor Mihai BLAGA, Gabor HEGEDUS, Virgil DOBROTA

Technical University ofCluj-Napoca, Communication Department, G. Baritiu Street, no. 26-28, tel. +40-264-401816,

Email: tudor.blaga; virgil.dobrota@com.utcluj.ro;hegegabo@yahoo.com

Abstract: End System Multicast (ESM) and HyperCast are overlay multicast proposals. Data forwarding is performed along paths from the overlay topology, which is built over the physical network topology and includes only end nodes. In this paper we study the performance and the efficiency of these two proposals. We use the following metrics: control overhead, time to first packet, stress, resource usage and stretch to determine the performance. Parts of the results are obtained using LOTOS (LOgical TOpology Simulator) from HyperCast.

Key words: Multicast, overlay.

SENSORS FOR OBSTACLE DETECTION IN TRAFFIC SCENE SITUATION

Anca DISCANT¹, Alexandrina ROGOZAN², Corneliu RUSU¹, Abdelaziz BENSRHAIR²

1. Technical University of Cluj-Napoca, Romania, Baritiu str, 26-28, 400027 Cluj-Napoca, Romania, ancad@bel.utcluj.ro

2. National Institute of Applied Sciences, Rouen, France

Abstract: The main sensors types used for the obstacle detection field are presented. They can be classified as proprioceptive or exteroceptive sensors, but also in two important categories: passive sensors (the cameras using visible spectrum-CCD and infrared cameras) and active sensors (radar, laserscanner, sonar). Generally, more camera types or configurations can be used in the obstacle detection domain: static or moving camera, monocular or stereo images, sequences or simple images, visible or infrared. Although, some segmentation methods used here are: stereo-based segmentation (the depth information of the objects), video-based segmentation (the motion information) and infrared-based segmentation (thermal information of objects).

Key words: exteroceptive and proprioceptive sensors, radar, laser, sonar, infrared camera.

DESIGN AND PERFORMANCE ANALYSIS OF REVERBERATION ALGORITHMS

Norbert TOMA, Marina Dana TOPA, Erwin SZOPOS

Faculty of Electronics, Telecommunications and Information Technology, Technical University ofCluj Napoca,

Str. G. Baritiu nr. 26-28, 400027, Cluj Napoca, Romania, phone: +40 264 401 243; fax: +40-264 591689

email: Norbert. Toma@bel.utcluj.ro, Marina. Topa@bel.utclaj.ro, Erwin. Szopos@bel. utcluj. ro

Abstract: The paper deals with the most important algorithms that simulate natural room reverberation. It starts with the description of the parameters used to evaluate the acoustics of concert halls followed by the presentation of a number of artificial reverberators. The structure, their design and a comparative analysis are given.

Key words: Early reverberation, late reverberation, comb filter, all-pass filter, acoustic parameters.