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INVESTIGATION OF HEURISTIC ALGORITHMS FOR ONE DIMENSIONAL OPTIMIZATION WITH ACCELERATED CONVERGENCE D. Borisov Key Words One-dimensional optimization; accelerated convergence; dichotomy; double dichotomy; algorithm efficiency; uncertainty interval Abstract A new heuristic optimization algorithm with accelerated convergence is proposed for search a maximum of one-dimensional (single variable), unimodal objective functions. The algorithm is a combination of the dichotomy method, the Kiefer–Johnson method, and the fourth grade functional series. A comparative analysis has been made with other known methods and its effectiveness and accelerated convergence have been demonstrated for cases where the uncertainty interval in the search is very large. The efficiency of the algorithm compared to other known algorithms is based on the number of the objective function evaluation to find the optimum with different accuracy requirements for localization the maximum (or minimum) of the function. The method and proposed algorithm is suitable for parameters estimation in mathematical models Article PDF Download article (PDF)

COMPUTATION OF THE TEMPERATURE FIELD AT COOLING OF LOGS BELOW THE FREEZING POINT OF THE MOISTURE N. Tumbarkova, N. Deliiski, N. Penkova, Å. Mihailov Key Words Beech logs; freezing; ANSYS; temperature field. Abstract An approach for modeling and computation of the temperature field in subjected to freezing logs with the help of software package ANSYS Workbench 16.0 has been suggested. Numerical results about the transient temperature fields in a beech log with a diameter of 0.24 m, length of 0.48 m, initial temperature of 22.4 °C, and moisture content of 0.63 kg·kg-1 during its 50 h cooling in a freezer at approximately –30 °C are graphically presented and analyzed. The root square mean error between the calculated and experimentally established temperatures of the studied log has been determined in order to validate the mathematical models Article PDF Download article (PDF)

AN APPROACH TO OPTIMIZE THE SETTING PROCESS OF RADAR COMPONENTS AT REPAIR Ch. Alexandrov, Y. Dachev, D. Dimitrakiev, E. Guglev Key Words Optimal control; constrained optimization; optimization model; global optimization; adaptive parameter Abstract In this case study the object of the research is the electronic components of the radiolocation system (RLS) for measuring the distance to marine objects. It is proposed an approach for automatic determination of operating parameters of the respective facilities and with optimization procedures to determine these parameters. The complexity and flexibility requirements of modern repairs of radiolocation components require to search for both local and global optimization [2,3], which is related to the specifics of the particular repair and the selected methods of formalization. The aim is to create a system for determination the optimal operating parameters of the radar components during the repair process. The optimization of impulse parameters means the choice of such values of the components parameters which complete the restrictions by value, imposed on them so that the parameters fall within the specified tolerance ranges according to the respective technical conditions . . . Article PDF Download article (PDF)

AMBIENT-ORIENTED CCA MODELING OF INTELLIGENT WHEELCHAIR IN VIRTUAL LEARNING SPACE T. Glushkova Key Words Ambient; Calculus of Context-aware Ambients (CCA); VelSpace Abstract This paper presents a Calculus of Context-aware Ambients (CCA) Model of Services for Students with Mobility Problems in the University Virtual Learning Space. These students will be represent in the system through their intelligent wheelchairs that will communicate with the learning environment to provide them the appropriate learning resources and services as well the best-suited route for moving in the real campus area Article PDF Download article (PDF)

KEY CONCEPTS OF THE DEPLOYMENT OF THE INFORMATION TECHNOLOGIES INFRASTRUCTURE LIBRARY (ITIL) – STRUCTURE, CONCEPTIONS, DEPLOYMENT Y. Mitev, L. Kirilov Key Words IT management; ITIL; integration; service transition Abstract This article gives the ITIL framework objectives, structure and functionalities. We explore the ITIL best practices with application to several real cases. It is shown where and how much ITIL is efficient in different real situations Article PDF Download article (PDF)