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

Now showing items 681-700 of 853

Title: Приложение на структури със зарядна връзка за реализиране на ортогонални преобразувания Author: Андонова, Анна Владова; Andonova, Anna Vladova; Филипов, Филип рец. Date: 1998 Abstract: In this paper an algorithm for fast Walsh-Adamar transformation is considered and an its application with charge coupled devices is offered. The possibilities of combining algorithm's structure and charge connection principles are investigated. A design of addition and subtraction cells of charge coupled devices is proposed. Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Satellite image processing and interpretation in environmental education Author: Gotchev, Gotcho Valev; Гочев, Гочо Вълев; Лазарова, Милена; Lazarova, Milena; Хачикян, Агоп рец. Date: 1998 Abstract: This paper concerns satellite data acquired by multi-spectral scanner (MSS) and Thematic Mapper (TM) sensors of American satellite system Landsat — 4 and 5, which are applied in ecological monitoring. Some basic methods and approaches for satellite image processing are discussed as filtration, edge detection, multi-spectral classification. ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Влияние на състоянието на изправителните вериги на възбудителната система върху асинхронния режим на турбогенератори тип ТВВ-220-2А Author: Калчев, Стоян Калчев; Kalchev, Stoyan Kalchev Date: 1998 Abstract: A specific asynchronous mode of generators type TVV-220-2A is considered when the excitation coil is closed through diodes and by-pass RC-circuit. The equations of stator and rotor electrical circuits are written in full and simple form and the results are given in tables and graphics. The result shows when by-pass RC-circuits are used, the ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Защита при асинхронен режим на мощни синхронни генератори Author: Вичев, Станимир Трифонов; Калчев, Стоян Калчев; Vichev, Stanimir Trifonov; Kalchev, Stoyan Kalchev Date: 1998 Abstract: This paper describes the selection of optimal characteristics and settings of the out-of-step protection of large synchronous generators under different faults of the excitation system. The investigation of these faults for generators type TVV-220-2A provide a possibility for selection of operation characteristic which detects the out of ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: A simple interval method for DC tolerance analysis Author: Kolev, Lyubomir Varadinov; Колев, Любомир Варадинов; Nenov, Ivo P.; Владов, Симеон рец. Date: 1998 Abstract: In this paper, the worst-case tolerance analysis of dc linear electric circuits is lered. A simple method for handling the problem is sugested which reduces to inverting tatrices and solving one system of linear equations. The method is more efficient comonwise than other known methods, providing solutions of sufficient accuracy. Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Комутационни пренапрежения и възстановяващи се напрежения при изключване на реактори 400 kV Author: Колев, Валентин Генов; Kolev, Valentin Genov; Тодорова, Антоанета рец.; Todorova, Antoaneta Date: 1998 Abstract: The switching and recovery transient overvoltages in case of disconnection of shunt 400 kV reactors of great capacity are investigated in the paper. A mathematical model and programme implementation with rendering an account of various factors on overvoltages in case of switching shunt reactor:, has been developed. A comparison has been ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Измерване на комутационни пренапрежения при изключване на разединител в ОРУ на ТЕЦ“ Бобов дол“ Author: Колев, Валентин Генов; Наков, Петър Митрофанов; Kolev, Valentin Genov; Nakov, Petar Mitrofanov Date: 1998 Abstract: This report contains basic results of switching overvoltages measurements during switching disconnectors with an attached to outdoor switchgear installation are analysed. Devices and methods for switching overvoltages measurement are shown. Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Приложение на модифицирани методи на Нютон за статична оценка на състоянието на електроенергийната система Author: Нотов, Петко Петров; Notov, Petko Petrov; Трингов, Димо Илиев; Tringov, Dimo Iliev Date: 1998 Abstract: In this paper are prepositional methods for solving static state estimation of electric power system problem. A methods for solving, advantages and problems are commented. Library:
TECHNICAL UNIVERSITY - SOFIA
Title: On the information, obtained from the identification of static parameters of electric drive Author: Popov, Ludmil Dimitrov; Билдирев, Жеко Събев; Попов, Людмил Димитров; Bildirev, Zheko Sabev Date: 1998 Abstract: A method for real-time evaluating of the armature resistance Ra and the coefficient of magnetic influation C has been shown. The method is justified for different cases of regulating and also for non-regulated drives. The results show a very high accuracy. The new information, provided by the method for thermometric and magnetic measurements ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Изследване на електрическото поле в изолационните системи на мощни трансформатори за високо напрежение по метода на крайните елементи Author: Мавродиев, Александър Атанасов; Mavrodiev, Alexander Atanasov Date: 1998 Abstract: The application programme package "ELFI", for the analysis of the electric field in the insulation systems of oil immersed high voltage power transformers using the finite element method is elaborated. The algorithm, the structure and the function of the individual programme modules are described. Some of the results obtained during the ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Възможности за разширение на диапазона на регулиране на скоростта при импулсно управление на асинхронни електродвигатели Author: Божилов, Ганчо Йорданов Date: 1998 Abstract: A possibility for extending the speed control range of conventional induction motors under pulse control is treated. This is obtained by connecting capacitors in series to each phase of the motor. As a results, the short circuit reactance whill be decreased, the critical slip whill be increased and the control range whill be extended. Both ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Параметрични трептения в една неавтономна линейна механична система със зъбни предавки Author: Белниколовски, Борис Гергов; Belankolovski, Boris Gergov; Симеонова, Дешка Митева; Simeonova, Deshka Miteva Date: 2001 Abstract: In this paper the parametric vibrations of one unautonomous linear mechanical system with gears are studied in the neighborhood of the first and second parametric resonance. The obtained equations of motion are being investigated and the conditions of unstability of the system in the first and second approximation are determined. Much ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Управление с диета [ограничаване на разходите] винаги, навсякъде във всичко Author: Сомлев, Пенко Пенков; Somlev, Penko Penkov Date: 1999 Abstract: This study aims to analyze the state of economical companies in the country and especially the privatized and planned to be privatized ones. The proper causes of their present unattractive state are brought up. The highlights include the areas and the particular activities that needs to be solved with a view of a future growth. The formed ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Синтез на признаци за разпознаване качеството на хранителни продукти Author: Дамянов, Чавдар Иванов; Damyanov, Chavdar Ivanov; Georgiev, Atanas Stefanov; Георгиев, Атанас Стефанов Date: 1999 Abstract: It is presumed in the paper that the optimal set of character is estimated by Bayes classifier which provides minimization of the classification error. Practical guides on character synthesis and their actual form applicable to the quality recognition of food products are set out. Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Оценка на грешките при класификацията на плодове и зеленчуци Author: Дамянов, Чавдар Иванов; Георгиев, Атанас Стефанов; Костадинова, Лена Филипова; Damyanov, Chavdar Ivanov; Georgiev, Atanas Stefanov; Kostadinov, Lena Filipova Date: 1999 Abstract: The analytical subjection's are derived and a characteristic drawn of the major errors estimating the functional suitability and accuracy of recognition in the automatic quality sorting machines for fruits and vegetables. Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Маркетингова стратегия и рискове при производство на титанови ортопедични консумативи Author: Бакърджиев, Димитър Христов; Москов, Антоний Тодоров; Минчев, Стоян Динев; Цанков, Дочо Цанков; Tsankov, Docho Tsankov; Minchev, Stoyan Dinev; Moskov, Antonii Tododrov; Bakardzhiev, Dimitar Hristov Date: 1999 Abstract: This paper is a research on strategical and tactical planning stages of titanium orthopaedical parts production. It contains a tnatketing activity analysis, market analysis, segmentation criteria, analysis and evaluation of purchase factors. A competitive comparisons an situation analysis are done too. There is an attempt on evaluation the risk Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Abstractions and simplification in teaching of distributed measurement systems Author: Kalchev, Ivan Denchev; Калчев, Иван Денчев Date: 1999 Abstract: A necessary background for clear outlined existing of each science in the so fast changing world is its permanent development in theoretical and applied aspect for solving today's problems and visions in the future. In this respect for the modern sciences still more important role play the theories, that not only generalize and explain the ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Основен курс по електромагнитна съвместимост – състояние и развитие Author: Лазаров, Атанас Илиев; Lazarov, Atanas Iliev Date: 1999 Abstract: This paper describes the establishment, content and experience with a course in Electromagnetic Compatibility (EMC). An analysis of the course is made and some considerations are given in regard with its further development in lectures, seminars and laboratories. The mile stone of the course development is its confirmation for the undergraduate ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Някои концепционни въпроси на ЕМС измерванията Author: Лазаров, Атанас Илиев; Lazarov, Atanas Iliev Date: 1999 Abstract: This paper describes the main aspects of EMC measurements namely approach, procedures_ methods and instruments. The problems of metrological assurance are not under consideration here. The EMC measurements are a special class of measurements for acquisition of measuring information concerning the estimation of characteristics of the ... Library:
TECHNICAL UNIVERSITY - SOFIA
Title: Подход за синтез на системи за управление при критерий минимум разход на енергия Author: Рабаджийски, Момчил Борисов; Rabadjiski, Momchil Borisov Date: 1999 Abstract: This paper suggests an approach for .quasi optimum control system synthesis with criterion minimization of energy consummation for plants with self regulation. This approach is based on linear approximation of optimal switching curve. A control system structure for quasi optimal control is proposed. The quasi optimal control is compared ... Library:
TECHNICAL UNIVERSITY - SOFIA