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Proceedings of the Technical university of Sofia, 1995 -: Recent submissions

Now showing items 361-380 of 853

Title: Designing the maximum possible sets of “Denim” fabrics.. Author: Elgohary, Fatma; Елгохари, Фатма; Дамянов, А. рец.; Damyanov, A. prew Date: 2005 Abstract: Designing parameters of fabric structure is a very important problem when designers of fabrics want to make a new fabric. There are many methods for designing different parameters of fabric structure; As result of many experiments Brierley derived four empirical formulae. in this study the maximum possible set of denim fabric are calculated ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Numerical model detecting the effect of inter-pass time on grain size for Nb-microalloyed stell. Author: Meliegy, Maha; Bitar, Taher; Tabakova, Bozhana; El-Meliegy, Maha; El-Bitar, Taher; Мелиеги, Маха; Ел-Мелиеги, Маха; Битар, Тахер; Ел-Битар, Тахер; Табакова, Божана; Лолов, Н. рец. Date: 2005 Abstract: An analysis was conducted on pass by pass to evaluate the austenite grain size during hot strip rolling of Nb microalloyed steel. This is achieved by using the available mill log data and the previously developed equations relating the rolling parameters to the grain size. The model calculates the total strain. Recrystallization and ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Analysis of a shielded coupled microstrip line by the boundary elements method Author: Savov, Vessel Nikolaev; Georgiev, Zhivko Kostadinov; Bogdanov, Emil; Karagineva, Irina Laleva Date: 2006 Abstract: A method for quasi-TEM analysis of a shielded coupled microstrip line is suggested The main point in carrying out this analysis is the solving of a system of two integral equations, which is performed by applying the boundary elements technique. Upon solving this system, the normal derivative of the electric potential is determined, as well ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Microcontroller orientated dual - slope analog-to-digital converter design Author: Yakimov, Peter Ivanov Date: 2006 Abstract: The paper discusses application of the dual slope analog-to-digital converters. Problems in power line noise suppression are presented. A possible solution of this problem is described using hardware and software designed phase locked loop. The paper presents solution the problems in dual-slope ADC by using microcontroller orientated design ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Analysis of possibilities for digital data transfer using powerline Author: Ovcharov, Stefan Jordanov; Yakimov, Peter Ivanov; Tuliev, Nikolay Todorov; Balkanska, Emiliya Georgieva; Penev, Dobromir Georgiev Date: 2006 Abstract: The paper discusses application of power line modems in homes and industry. The requirements of the standard ЕN 50065 are explained. Problems in power line modems operation are presented. The comparison of different devices is performed. The methods for electrical isolation are described. Proposals for using electric power network for data ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Laboratory stand for investigation of optoelectronic measuremet devices with CMOS image sensors and programmable logic Author: Djamiykov, Todor Stoyanov; Nenov, Nikolay Hristov Date: 2006 Abstract: The proposed paper presents features of laboratory stand for investigation of optoelectronic measurement devices. Various methods for measurement of different parameters with high accuracy in real time are described. CMOS image sensor is used. For calculations in each measurement programmable logic is used. PLDs have great advantages in ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Interpolation of green color in frames from CMOS image sensor Author: Djamiykov, Todor Stoyanov; Nenov, Nikolay Hristov Date: 2006 Abstract: The paper presents an algorithm for interpolation of the green pixels in frames from CMOS image sensor. The result is a monochrome frame calculated directly from the data from the primary BAYER matrix in the sensor. An algorithm and VHDL module work in real time were developed. The aim is simple and easy for usage algorithm, which uses small ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: DC motor control systems Author: Hristov, Marin Hristov; Kubatev, Gavrail Shtilionov; Arabadzhiev, Dobromir Nikolov Date: 2006 Abstract: Modern day decisions, when classifying motor controllers are divided into two categories. The first is swiftness and accuracy at the price of expensive products and the other – worse characteristics, but with more affordable prices. The presented article shows a method for digital control of a DC brush motor, and by this, showing one good ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Analysis on choosing the appropriate accelerometer for transport vehicle diagnostic systems Author: Dilov, Kristian Dilov Date: 2006 Abstract: A big variety of integral accelerometers is available nowadays. For the goal it is necessary to be made an accuracy analysis of the parameters of the separate presents that would had help at choice of accelerometer in concrete application. The head parameters of this analysis are frequency bandwidth, noise stable and sum error from the transduction. Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Fluid level regulator Author: Mihov, Slavy Georgiev; Jilov, Stoyan Nikolov Date: 2006 Abstract: Beverage lines are very common installations in food production industry. They automate the processes of washing and labeling bottles, bottling liquids in them, counting and sorting the production and so on. The present paper concentrates on the process of bottling. It aims filling the bottles with beverages such as beer or any kind of ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Smart OBDII interface adapter Author: Dzhelekarski, Peter; Alexiev, Dimitar Serafimov Date: 2006 Abstract: The vehicle on-board diagnostics system (OBDII) provides a serial diagnostic link for communication with scan tools. There are 4 diagnostic interfaces: ISO 9141-2, KWP 2000, SAE J1850 and ISO 15765. A PC-based scan tool consists of an interface adapter and specialized diagnostic software. This paper presents the implementation of a smart ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Measuring physical dimensions with laser beam and programmable logic Author: Djamiykov, Todor Stoyanov; Donkov, Yavor; Rusev, Atanas Date: 2006 Abstract: In this report are represented the possibilities of the contemporary electronic elements when building optoelectronic measurement devices. In this type of devices the basic components are: a light beam source, photo receiver, managing system for both the light source and the light receiver (this system also processes the received light ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Air quality monitoring system Author: Nikolova, Boyanka Marinova; Marinov, Marin Berov; Nikolov, Georgi Todorov Date: 2006 Abstract: Detection of low concentration of air pollution, like cigarette smoke, cooking fumes, etc. is possible with the combination of an air quality sensor and data acquisition system. In present paper is presented approach for design and implementation of air quality monitoring system based on tin dioxide gas sensor, integrated temperature and ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: RLC measurement using virtual counting techniques Author: Nikolov, Georgi Todorov; Stoyanov, Ivan Iliev; Nikolova, Boyanka Marinova Date: 2006 Abstract: In the present paper a frequency mode data acquisition technique, which converts resistance, capacitance or inductance values into a frequency-based signal by placing the measured element into a relaxation oscillator is considered. The system is realized using low cost oscillator with one comparator and capability of virtual instrumentation. ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Design of RLC to frequency converter Author: Stoyanov, Ivan Iliev; Nikolov, Georgi Todorov; Nikolova, Boyanka Marinova Date: 2006 Abstract: This application specific paper describes a design approach for RLC to frequency converter based on relaxation oscillator techniques. The designed circuit is proposed to convert resistive, inductive and capacitive values into corresponding frequency. The design process is accomplished using electronic design automation environments. Using ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: High power laser diode driving techniques Author: Todorov, Dimitar Georgiev; Grigorov, Asparuh Ivanov Date: 2006 Abstract: The present paper is about driving high power laser diodes. In many areas, such as communication, medicine and military equipments, the high power laser diodes find many applications. In the same time there isn’t a lot of literature about their driving. In this paper some driving circuits and algorithms are discussed. The driving circuits ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Digital regulated parallel power and current sources for laser diodes driving Author: Todorov, Dimitar Georgiev; Grigorov, Asparuh Ivanov Date: 2006 Abstract: This paper is about some switching regulator improvement techniques, especially designed for high power laser diode driving. The first one consists in the usage of several power stage capacitors connected in parallel, forming a capacitance sum, witch is determining the output current or power. In this way an easier and more accurate digital ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Investigation of the linearity criterion used by the subtraction method for removing powerline interference from ECG Author: Mihov, Georgy Slavtchev Date: 2006 Abstract: The detection of linear segments in ECG signals is the most important phase of the subtraction method for removing powerline interference. This is done by a criterion for linearity using second differences in the sampled signal. The criterion is interpreted as mathematical estimate of the acceleration within the segment and is substituted ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Subtraction method for removing powerline interference from ECG in case of frequency deviation Author: Mihov, Georgy Slavtchev; Ivanov, Ratcho Marinov; Levkov, Chavdar Lev Date: 2006 Abstract: Extension of the subtraction method for power-line interference removing from ECG signals is proposed in case of power-line frequency variations. The existing version suitable for non-multiplicity between sampling rate and interference frequency is improved and adapted to dynamic deviations around the rated power-line frequency. The ongoing ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Real-time detection of accidental pathologic cardiac events in the electrocardiogram Author: Iliev, Ivo Tsvetanov; Krasteva, Vessela Tzvetanova; Tabakov, Serafim Dimitrov Date: 2006 Abstract: The major efforts for improving the automated cardiac diagnostics are directed towards developments of innovative hardware and software solutions for computer-assisted electrocardiogram (ECG) monitoring systems. The presented work describes a method for fast detection of pathologic cardiac events by real-time ECG analysis. It is convenient ... Library:
TECHNICAL UNIVERSITY - SOFIA