Short history

The presence of Rousse in the history of Bulgaria can be measured not only by its nineteen centuries of architectural and industrial construction, but also by its rich cultural heritage and the spirit of enterprise. It was in Rousse where the first embassies were established, it was in Rousse where the first Bulgarian ship was built and where national shipbuilding industry began; it was in Rousse where the first Bulgarian chamber of commerce, insurance society, technical society, teachers' society, weather forecast station, printing press, film show, and railroad, were opened. It was again in Rousse where, for the first time in Bulgaria, the first geographical map, the first Bulgarian newspaper, and the first textbook in agriculture were published. Also, it was in Rousse where the foundations were laid for the professional courses in farming machinery.

In 1909, the Higher Course in Pedagogics was established, later, in 1921, to become a Teacher Training College. In 1945, the citizens of Rousse initiated the idea of establishing a polytechnics, which was approved by Decision of the Ministry of Councils of 30 October 1945 and Act N 8618 of 14 November 1945. That was how the first higher technical school outside the capital came to existence.

It took the new higher school a lot of time to develop into what it is today, the University of Rousse. For example, in 1954 was established the Institute for Mechanization and Electrical Supply of Agriculture, later to become the Higher Institute of Machine-building, Mechanization and Electrical Supply of Agriculture, and the Higher Technical School 'Angel Kanchev'. With the N 37/21.07.1995 Decision of the National Assembly, it was transformed into the University of Rousse 'Angel Kanchev'. The University of Rousse is an autonomous state higher educational institution, which comprises seven main faculties: the Faculty of Agricultural Machinery and Mechanization of Farming; the Faculty of Industrial Engineering; the Faculty of Electronics, Electrical Engineering and Automation; the Faculty of Automobile Engineering and Design; the Faculty of Business and Management; the Faculty of Pedagogics, and the Faculty of Law. There are also the Faculty of Postgraduate Studies and Supplementary Education; the Silistra branch of the University of Rousse, including a Faculty of Pedagogics, and a Technical College; and a College of Technology in Razgrad.

The total number of both full-time and extramural students amounts to 7611. The modes of payment are state funding and private payment.

The University of Rousse has a Research Centre, a University Library, its own production works, a Publishing Centre, and a Computer Centre. It is one of the first Bulgarian universities to be included in INTERNET, which opens unexplored possibilities for broadening the contacts with the world. b) Special departmental resources like computer facilities, libraries etc.

Local computer networks have been established in most departments and faculties and they are linked into a common University network. Access to Internet is provided. There is a concentration of equipment in computer rooms and depending on the type of classes or research going on there, some specialized hardware and software packages are provided. Generally, these are computer-aided design systems intended for different areas - agriculture, mechanical engineering, car transport, electronics, computer and communication technology, etc.

The University boasts one of the largest and best organized libraries and its computerization is in the final stage.

Research Programmes

PARTIAL DIFFERENTIAL EQUATIONS
An Introduction with Mathematica and Maple
I. Stavroulakis, S. Tersian
This textbook is a self-contained introduction to partial differential equations. It is designed for undergraduate and first year graduate students who are mathematics, physics, engineering or, in general, science majors. The goal is to give an introduction to the basic equations of mathematical physics and the properties of their solutions, based on classical calculus and ordinary differential equations. Advanced concepts such as weak solutions and discontinuous solutions of nonlinear conservation laws are also considered. The material is illustrated with model examples. Mathematics software products such as Mathematica and Maple in ScientificWorkPlace are used in both graphical and computational aspects.

Nikolov, Y.
AN ACCELERATED ITERATIVE PROCEDURE FOR SOLVING OPTIMIZATIONAL PROBLEMS THROUGH THE FINITE ELEMENT METHOD
TECHNISCHE MECHANIK, Magdeburg, Band 17, Heft 1 /1997
The calculation procedure offered works with the initial stiffness matrix and the changes caused by the changes in the discretized body are specified by iteration. Each consecutive iteration is carried out by approximation of the sought precise change, constructed on the basis of the simple increments of nodal displacements known by that moment. When the approximation does not satisfy the accuracy requirements, the simple increment is found on the basis of the results obtained and it is also taken into considerations when the next approximation is found.

Kouymdjiev, H., I. Ivanov, R. Tanov
DETERMINATION OF STRESS IN COATINGS BY THE BENDING STRIP METHOD IN THE CASE OF LARGE DISPLACEMENTS SURFACE AND COATINGS TECHNOLOGY, 113/1999
The classical formulae for determining stress in coatings by the bending strip method are accurate for small displacements. Since the actual measured displacements are often greater, the question for their applicability arises. The present work provides an answer by solving a geometrically non-linear problem of the theory of elasticity. Two plastically applicable conditions for reaching a minimal admissible error are given.

Tomov, B., V. Gagov
MODELLING AND DESCRIPTION OF THE NEAR-NET-SHAPE FORGING OF CYLINDRICAL SPUR GEARS
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY, 92-93/1999
The manufacture of bevel and cylindrical spur gears by the means of applying hot or cold bulk forming processes is a quite widespread production method due to its well-known basic advantages, such as material and time cost reduction and the increased strength of the teeth. However, the associated process planning and tool design are more complicated compared with those of other conventional forging or rolling technologies. This paper aims at a concise description of some die forging operations selected as representative steps for the near-net-shape forging of spur gears. The main results are obtained on the basis of quasi-static model material experiments that have been applied to collect data needed for statistical processing or to verify some analytical solution and computer simulations. These results could be helpful in engineering practice for simple calculations in process planning design.

Shishkov, R., E. Lisichkova
A GENERAL MODEL FOR VACUUM CONDENSATES AND VACUUM DIFFUSIVE COATINGS
PERGAMON 0042-207X(95)00020-7, Vacuum/volume 46/number 11/1995
The paper suggests a general model for the classification of metal coatings obtained in vacuum. The model gives the thickness, the bond character and the bond to the coated substrate, depending on: temperature, forming time and condensation rate. The coatings have been classified in two basic groups: vacuum condenses and vacuum diffusive coatings, separated by a layer zone having an intermediate character. The model is presented graphically and a prognosis is made on the change in thickness of the coating of each group, changing the technological parameters. The model suitability is tested for coatings obtained in a vacuum furnace by magnetron sputtering of a ferro-chromium target in a neutral medium by the method of plasma vacuum diffusive metallizing in element sputtering conditions (PVDM-E) on steel substrates with a composition (12%Cr; 1.5%C; 0.5%Mo), in the temperature range 850-1000°C and a process duration of 60-120 min for two condensation rates. The thickness, the structure and the phase composition of the coatings are presented by the three-coordinate figures. A classification has been made, according to the suggested general model.

Ivanov, S., P. Vitliemov
TABLE-DRIVEN PARAMETRIC RE-DESIGN OF ROBOTIC GRIPPERS
Proceedings of THE 8TH INTERNATIONAL WORKSHOP ON ROBOTICS IN ALPE-ADRIA-DANUBE REGION RAAD 1999, Munich, Germany, 1999
The parametric design in the recent CAD-systems is realized mainly in an interactive regime. The CAD-systems allow easily creating a partial parametric model. The major parameterization of the model is connected with specific calculations, about which can be created programs, as a superstructure of the CAD-system. We developed a methodology for the CAD-system Pro/Engineer regarding the partial automation of the parametric design with KAPPA-PC and an interface between the two systems using Family Tables. The methodology is implemented in the design of robotics grippers for handling non-rigid materials.

Korijkov, Ts., S. Tsankov
QUALITY CONTROL PRINCIPLES
Proceedings of X National scientific conference with International participation " QUALITY FOR BETTER LIFE '99" Sofia, November 1999
This article is based to the importance of activities of quality management control. There are formulated and analyzed principles that build modern organization of quality control. Discussed are approaches that lead to reduction of quality control costs.

Armyanov, N., I. Palov, S. Stefanova, S. Stefanov, T. Stoyanova, K. Sirakov
POSSIBILITIES OF STIMULATING POTATO PRODUCTION BY MEANS OF PREPLANTING ELECTRIC SPARK PROCESSING OF THEIR TUBERS
Proceedings of International conference "ENERGY AND AGRICULTURE TOWARDS THE THIRD MILLENIUM"
Agricultural University of Athens, Greece, 2-5 June 1999
Results from testing the frequency characteristic of the root crops' (such as potatoes, sugar beet, carrots, etc.) impedance have been presented in the paper. A circuit diagram of the plant tissue of potato tubers has been suggested on the basis of this research. In connection with stimulating potato production, damaging of the potato tubers' tissue caused by electric spark treatment has been analyzed. Results from field tests for establishing the effect of the treatment has been cited.

Smrikarov, A., S. Smrikarova, N. Mohamed, T. Vassilev
TRAINING MODELS OF OPERATIONAL BLOCKS TO PERFORM ARITHMETIC OPERATIONS
Proceedings of 38-th SCIENCE WEEK of the University of Homs, Syrian Arab Republic, November 1998
This paper analyzes a processor based upon microprocessor sections. It has been concluded that when performing the operation "multiplication", if all components not participating in the operation are excluded, the processor can be considered as a device completely identical in circuitry to an operational multiplying block based on one of the classical methods - "Multiplication with the least significant bits of the multiplier and shifting the sum of partial products right". Following this conclusion, software models of variety of operational blocks have been developed: for number conversion from one system of notation to another, for addition, multiplication, division and square root. They are used to test and evaluate the progress of the students in "Computer systems and technology", "Mathematics and Informatics" etc. in courses like "Foundations of computing machinery".

Zheliazkova, I., G. Georgiev, M. Velikov, G. Rashkov
ORGANIZATION OF MEASURMENT SYSTEMS IN AN EVENT PROGRAMMING ENVIRONMENT
BULGARIAN AUTOMATICS AND INFORMATICS, Sofia, 6/1999
In an event-driven programming environment the investigator becomes an active agent during the three stages of the measurement process: data asquision, data analysis, and data presentation. The paper deals with the main problems, arising when a DAQ-system is organized in such an environment, namely: necessary additional hardware, hardware control, and user interface. In parallel the authors' experience concerning a given DAQ-system is shared.

Lehov, G.
AN ADAPTIVE PID-BASED ROBOT CONTROLLER WITHOUT VELOCITY MEASUREMENTS
Proceedings of 6-TH INT. WORKSHOP ON ROBOTICS IN APLE - ADRIA - DANUBE REGION Cassino, Itali,1997.
An adaptive PID-based robot control using only joint position measurements is presented in this paper. The closed - loop adaptive system is proved to be semiglobally ultimately bounded in the presence of model parameter uncertainties, friction torque's and bounded disturbances. Relations for selecting the controller gains are derived which guarantee stable implementation of the controller. Simulation results that demonstrate the effectiveness of the control scheme are presented.

Kozlev, R., I. Stanev, Tz. Vezirov.
AN INTELLIGENT SYSTEM ARCHITECTURE FOR DRIVER TRAINING
BULGARIAN ELECTROTEHNIK AND ELECTRONIC, 5-6/1999
The architecture of an instrumental environment for computer simulation of motor vehicle behavior is considered in this paper. The components of the instrumental environment are described and a solution for its realisation is suggested.

Entchev, K.
A NEW LOCUS CURVES IN THE FIELDS OF THE SOLUTIONS OF B4-PROBLEM
TENTH \WORLD CONGRESS ON THE THEORY OF MACHINES AND MECHANISMS
Oulu, Finland, June 20-24, 1999, Machine Mechanics, No: 25
The contributions of this paper are in the area of the Kinematical geometry of the infinite-simally close positions. It is found that there exist two locus curves-circles, and they are analogous of higher order to the inflection circle and return (cuspital) circle. It is found also a spacial third circle, that serves for easily building of the circling-point curve and the centering-point curve

Danev, P., V. Stoyanov
OBTAINING OF INTER-METAL FE-SN COMPOUNDS IN MULTI-LAYERED ELECTROLYTIC COATINGS DURING ANNEALING
Proceduring of the 8th International Scientific Conference "ACHIEVEMENTS IN MANUFACTURING ENGINEERING"
October 24-27, 1999, Gliwice, Poland
Fe-Sn inter-metal compounds are being used to prevent critically loaded surfaces from scuffing. The paper presents some results from investigations carried out on the obtaining of inter-metal multi-layered electrolytic Fe-Sn coatings. The results confirm the possibility to run the "Stanal" process by multi-layered coatings of electrolytic iron and tin.

Nenkov. M., T. Pencheva
SYMMETRICAL FIVE LAYER PERIODS FROM NONABSORBING HIGH AND LOW REFRACTIVE INDEX MATERIALS
JOURNAL OF OPTICAL SOCIETY OF AMERICA A, 1997
Some properties of five layer symmetrical periods from two nonabsorbing dielectric materials with high and low refractive indices are discussed. Conditions are derived for which two high reflectance spectral regions (stop bands) are suppressed. Period structures with two successive stop bands suppressed are proposed. The results are applied to starting design of a multilayer heat reflector with high visible transmittance using only two materials.

Popov, D., Tz. Uzunov, T. Pencheva, P. Docheva
OXIDATION INDUCED CHANGES IN THE THIN FILMS DEPOSITED BY MAGNETRON SPUTTERING OF STAINLESS STEEL THIN SOLID FILMS, 1986
Stainless steel films deposited onto a glass substrate to form an optical wedge were oxidized by means of isothermal annealing in air at 150oC. The transmittance of the optical wedge at 650 nm varied continuously from 92 % at zero film thickness to 5 % at a film thickness of 60 nm, i.e. the optical transmittance of the wedge was changed by oxidation. The dependence of the change in transmittance of the film thickness exhibits a maximum from which the depth of the oxidized metal layer can be obtained.

Nenov P. , E. Anguelova, B. Kalojanov, A. Tufektchian
PARAMETRICAL OPTIMISATION OF EXTERNAL CYLINDRICAL GEAR DRIVES ON A GEOMETRICAL LEVEL
Proceedings of 4th World Congress on Gearing and Power Transmission CNIT - Paris, France, 1999
The experience of the authors suggests that in many cases the design process of gear drives with optimal parameters requires the creating and analysis of corresponding graphic images which represent three-dimensional models of the geometrical, kinematics and load-sharing characteristics of the gear drive. We called those models and their modifications Parametrical Blocking Contours (PBC) and create them automatically using a software package, developed by the authors.

Gizdarski, E., H. Fujiwara
A NEW DATA STRUCTURE FOR SAT-BASED STATIC LEARNING WITH IMPACT ON TEST GENERATION
Technical report, NAIST-IS-TR2000001, January 2000
In this paper we analyze learning techniques based on the Boolean satisfiability method and find that static indirect AND-implications and the super gate extraction approach are useful for increasing the precision of low complexity learning procedures. We propose a new data structure for the complete implication graph that allows efficient processing of the static indirect AND-implications. We show that by deriving and performing the static indirect AND-implications, some hard-to-detect static indirect implications can be easily found during static learning. In addition, the static indirect AND-implications can be used to perform (without spare operations) some dynamic indirect implications during branch and bound search and dynamic learning. In this way, the new data structure of the complete implication graph increases efficiency and precision of both static and dynamic learning as well as branch and bound search. We utilize this data structure in development of an implicit static learning procedure. Experimental results for static learning and redundancy identification confirm their efficiency and precision. Further experimental work shows a positive impact of low complexity static learning on the efficiency and robustness of even combinatorial test generation. We expect that the contribution of the new data structure will be more visible when the super gate Extraction approach is also implemented.

Ivanov R, S. Liubenov
POSSIBILITIES FOR REDUCTION OF THE TIRES WEAR THROUGH THE DESIGN PARAMETERS OF THE STEERING AXLE Proceedings of INSTITUTION OF MECHANICAL ENGINEERING,
Part D: Journal of Automobile Engineering, vol. 209, 1995
Two conditions for minimal wear of the front wheel tires are defined. Methods to comply with these conditions through the design parameters of the steering axle are stated. An optimization of the steering axle parameters of a concrete agricultural tractor was done by using the formulated conditions. An experimental corroboration was finally carried out.

Russev R., D. Nhu, T. Todorov, I. Petrov
A STUDY OF THE LONGITUDINAL SLIP AND SIDE SLIP OF A WHEELED TRACTOR UNDER VARIABLE VERTICAL LOAD HEAVY VEHICLE SYSTEMS, INTERNATIONAL JOURNAL OF VEHICLE DESIGN Vol. 2, No 3-4/1995
In this paper is shown that the variable normal road reaction exerts a negative effects on the reactive performances and the lateral stability of the tractor, and that this should be taken into account when predicting and analyzing the dynamic characteristics of the tractor.