Carpathian Journal of Electrical Engineering

Volume 1, 2007 - Number 1

Tranzactions on Electronic and Computer Engineering

Obstacle Recognition in the Ruttier Scene
Apatean (Discant) Anca Ioana, Technical University from Cluj-Napoca, Romania
Abstract: Applications of wavelet analysis are widespread and cover many fields of scientific research including image processing, classification and recognition. The artificial vision systems was developed having as model the human system, and therefore the objects recognition task is reduced to a classification: the recognition of an initial unknown object through detection of the similarities to another object, previously learned. Our purpose is to study the obstacle recognition in the ruttier scene using wavelet transform. We compared different recognition rates obtained by the use of different mother wavelet functions (as Daubechies, Coiflet, Biorthogonal and the recent discovered ones, named fractional B-splines).
Keywords: wavelet analysis, B-spline functions, obstacle recognition

Signal Energetic Anaysis Using Fractional B-spline Wavelets
Author: Simina Emerich, Technical University of Cluj-Napoca, Communication Department, Romania
Abstract: Over recent years, applications of wavelet analysis are widespread and cover many fields of scientific research. Splines had a significant impact on the early development of the theory of wavelets. In fact, they constitute a case apart because they yield the only wavelets that have an explicit analytical form [1]. We are interested to develop an algorithm through which we represent the spectrogram and scalogram of different signals using the family of B-spline fractional functions.
Keywords: wavelets, B-spline functions, scalogram, spectogram

Sensitivity in Circuit Design
Erdei Zoltan, Faculty of Engineering, North University of Baia Mare
Abstract: Suppose that appropriate circuit simulators have been used to see whether or not a given electronic circuit with fixed parameter values meets the design specification. For a linear circuit, the design specification may be represented by a given network function, e.g. the voltage transfer function of the circuit. From a practical point of view, it is not sufficient for the design specification to be satisfied for a fixed set of nominal parameter values. A circuit designer should know how the circuit performance is affected by changes in one or more parameter values. Any effect of the network function or any other circuit characteristic caused by a change in one or more circuit parameters is referred to as network sensitivity.
Keywords: sensitivity, electrical circuits design.

Speaker Identification System Using Cepstal Coefficients and Dynamic Time Warping Algorithm
Marieta Gata - North University of Baia Mare;
Gavril Toderean
- Technical University of Cluj Napoca
Abstract: Speaker recognition is the process of identifying a person based on his voice. Speaker recognition includes both verification and identification. A text dependent speaker identification system based on cepstral analysis of speech signals is presented along with the results of its performance and studying effect of some parameters on speaker recognition accuracy.
Keywords: speaker recognition, cepstrum, pattern matching, dynamic time warping.


Preprocessing iris images using Matlab

- Adrian Lodin, Laura Kovacs - Technical University of Cluj-Napoca, Basis of Electronics Department
- Sorina Demea
- Oftalmological Center of Investigation REVIEW, Cluj-Napoca
Abstract: This paper presents a method of processing some “eye” images using Matlab structures and toolboxes. The concept of the program is described starting from the needed images. These eye images, taken from the human patience, will be processed in order to get all the useful information. The goal of the project is to find the best method for processing these images in the fastest way possible. In this paper we’ll present the iris detection part from the entire image processing.

Obstacle Detection and Movement Implementation for Autonomous Robot
: Lung Claudiu Ionel -  North University of Baia Mare
Abstract: This paper presents the design of an autonomous robot that can move freely in different spaces and avoid collision with objects. The project main purpose is to implement into the Nexys board all the modules that are necessary to accomplish this goal. In this phase, the project has the minimum required components to ensure full functionality.

Embedded Voltage Reference in DACS and ADCS
Author: Stefan Marinca - Analog Devices B.V., Limerick, Ireland.
Abstract: Any Digital to Analog Converter (DAC) and Analog to Digital Converter (ADC) requires a voltage reference. One main limitation in precision conversion is reference voltage accuracy. Embedded voltage references in DACs and ADS are based on bandgap principle which offers a few important advantages over zener diode type voltage references: low voltage and low current operation, low noise and good Temperature Coefficient (TC). There are many specifications which determine the quality of a bandgap voltage reference: TC, temperature range of operation, supply current, low band and high band noise, minimum supply voltage, Power Supply Rejection Ratio (PSRR), load current (sink and source), thermal hysteresis, long term and high term stability, etc. This paper will present the basic architecture of a typical bandgap voltage reference and some recent ADI improvements in bandgap voltage references.
Keywords: embedded, bipolar transistor, CMOS, bandgap voltage reference.


Emerging Options in Microcontroller Peripherals
Tom O’Dwyer - Analog Devices B.V., Limerick, Ireland
Abstract: The ever-increasing density of silicon process technology, coupled with emerging new circuit architectures, is enabling a whole new range of options for designers of embedded systems. Systems which were once limited to an 8-bit processor with very basic peripherals such as 8-bit data converters, have in recent years been replaced by high end RISC engines, with a myriad of options in terms of SDRAM, FLASH memory, and high resolution data converters. The selection of available embedded data converters in particular, has seen dramatic improvement in recent years. Analog-to-digital converters with resolutions up to 24bits have emerged, and DACs with resolutions up to 16 bits are now available.
Using the microconverter family of products from Analog Devices Inc. as a case study, this paper will outline the wide array of options available. It will also discuss the architectures used for the peripheral blocks in these embedded systems, and will outline the advantages and disadvantages of each for different applications.

Keywords: embedded, microcontroller, embedded data converter, embedded ADC, embedded DAC, microconverter.

Communication and Automation Applications using Basic Tiger Embedded Multitasking Computers
Emil Plaian - AC DC Echipamente Electronice SRL Cluj-Napoca;
Walter Pies - ICET Logistics SRL;
- Eugen Lupu
- Technical University of Cluj-Napoca
Abstract: This paper presents the facilities of developing applications based on the BASIC Tiger embedded multitasking computers offered by Wilke-Technology and briefly exemplifies by the following practical applications:
- Ethernet, GSM and GPS communication applications using the 1100IL educational Kit;
- Automation and distance surveillance application using the Programmable Control Logic (PLC) Boards 4403IL (based on Tiny Tiger module), 4404IL (based on Econo Tiger module), Extension I/O modules (2201IL, 2202IL) and the Telephone Module 4410IL.

Keywords: Basic Tiger, embedded multitasking computer, educational kit, communication module, GSM, GPS, DTMF, PLC board

Package Influence on Time Budgets in High-Speed Embedded Systems
Marius RANGU - “Politehnica” University of Timisoara, Electronics and Telecommunications Faculty
Abstract: Embedded systems use digital signals that propagates along physical structures between silicon chips, comprising on-chip interconnections, soldering pins, printed circuit board traces and vias, generally denoted as “package”. Although often idealized by system designers, the package actually represents a passive circuit that influences the signal propagation and causes additional noises and delays, more pronounced as the rate of change of the signals goes smaller. On high-speed applications, the propagation delay becomes comparable with the time constants of the system and thus require special attention. This paper analyses the most common delay-causing effects of the packages, such as propagation delay, settling time and clock skew, and their influence on time budgets on high speed embedded systems.
Keywords: time budget, propagation delay, settling time, clock skew.


Digital Signal Processors and Microcontrollers for Embedded Systems
Tihamér Ádám - University of Miskolc, Faculty of Mechanical Engineering and Information Science, Department of Automation
Abstract: The first part of the paper introduces the program optimization possibilities of a high performance DSP. The main hardware features of the processor and the components of the VLIW CPU (DSP core) are introduced. The program development tools of the processor consists of C /C++ compiler, assembler, assembly optimizer, library handling programs, linker, debugger tools, EPROM utilities etc. The time critical program parts can be determined by profiling tools and the program can be optimized with C compiler optimization options, or can be rewritten in linear assembly and the assembly optimizer can optimize this code. The steps of the optimization procedure are shown.
In the second part a different device, a special high performance microcontroller is described. The so called digital signal controllers are a mixture of DSP and microcontroller and are specially designed for real-time industrial control applications. The devices are suitable for realization of single-chip industrial ac and dc motor controllers.

Keywords: linear assembly code, dependency graph, iteration interval, loop prolog, epilog.

Optical Fourier Analyses of a Simple Optical System
Author: Toadere Florin - Technical University of Cluj-Napoca, Romania
Abstract: This paper presents a classical application of the optical signal processing. This is made by the means of the optical device which can make optical Fourier transform (a convergent lens). These kinds of application have a great applicability and can be generalized in optical systems.
Keywords: lens, aperture, Fourier optics.

An Introduction to Embedded System Design
József Vásárhelyi - University of Miskolc, H3515 Miskolc-Egyetemváros, Hungary
Abstract: The purpose of this paper is to summarize some aspects of the embedded system design. Designing an embedded system is often a compromise between the design optimization and design specification expressed by the design metrics. The design is also a balance between hardware and software and a compromise or a trade off exists when decision is made.
Keywords: embedded system design, design metrics, hardware-software co-design.

Spice - The Fifth Decade a State-of-the-Art of Electrical Simulation and Modeling
Author: Andrei Vladimirescu - University of California, Berkeley
Abstract: This paper describes the evolution of the circuit simulator SPICE currently in its fifth decade, from the UC Berkeley student project to its many versions and derivative programs, and, its impact on the progress of the Integrated Circuit, IC, industry. The two main components of a circuit simulator, algorithms and device models, are going to be detailed in the presentation. Emphasis will be placed on new functionality added by commercial SPICE versions in the last decade to cope with the progress in IC technology. 
Keywords: SPICE, Integrated Circuits, Electrical simulation, Solution algorithms, Semiconductor device modeling.


The Automation of a Cardboard Cutting Machine with MFD Titan Intelligent Relay
Author: Cristian Barz, Constantin Oprea - North University Baia Mare, Romania
Abstract: Introducing the programmable automatons on a larger and larger scale due to their quality and working precision, as well as due to a good price/quality report, imposes them for the substitution of the old command schemes of equipments. The present paper presents the realization of the command for a cardboard wrapping cutting machine with the help of a MFD Titan intelligent relay, which, together with a frequency converter for running the equipment’s engine, replaced the human operator, increasing in the same time the speed and the working precision.
Keywords: programmable automaton, command scheme, automation

OP AMP Circuit Analysis Using ßµ Plot Method
: Mircea Bodea, Claudius Dan, Marius Padure, Claudiu Patru, Costin Gavrilescu - " POLITEHNICA" University of Bucharest, Romania
Abstract: This tutorial paper presents so called “βμ plot” method for closed loop voltage feedback operational amplifier circuits’ analysis. The approximations currently involved are underlined and some circuit analysis examples are presented in order to illustrate the method.
Keywords: voltage feedback op amp, βμ plot, closed loop frequency response

CMOS Bandgap Voltage Reference using a Chopped Amplifier
Alexandru Chiculescu, Valentin Chesaru and George David - O2 Micro Romania s.r.l., Bucharest, Romania
Abstract: In this paper we present a CMOS bandgap voltage reference using a chopped amplifier. The effect of the amplifier input offset on the output voltage is significantly reduced. This configuration is easy to implement and offers some advantages over other offset cancellation methods which require precise capacitors and occupy a lot of silicon area.