INSTITUTE OF INFORMATION TECHNOLOGIES - BAS

Department: "Soft Computing"
Head of Department: Academician Dr. Sc. IVAN POPCHEV

Main Research Directions:
Analysis of systems under uncertainty and risk
Decision making under uncertainty in a fuzzy environment

ANNUAL REPPORT OF DEPARTMENT ”SOFT COMPUTING” FOR 2008


The department of Soft Computing, consisting of: Scientific area: Development of algorithms for multicriteria decision making in fuzzy environment.
Applied area: Application of innovation information technologies in wind turbine electro – generator fields design and risk evaluation.

The Department actively participates in National R&D projects and presents the results in international and national journals and conferences.

Participation in National R&D Projects: TEACHING ACTIVITY: SELECTED PUBLICATIONS:
Analysis of systems under uncertainty and risk
  1. Konstantinov M., P. Petkov, I. Popchev, V. Angelova: Perturbation bounds for the matrix equation . - Comptes rendues de l’Académie bulgare des Sciences, Mathématiques, Mathématiques appliqués, vol. 61, No 9, pp. 1111-1120, 2008.
  2. Konstantinov M., P. Petkov, I. Popchev, V. Angelova: On the sensitivity of the matrix equation XA - AX = X2. Cybernerics and Information Technologies, vol. 2, pp. 3-11, 2008.
  3. Savov, S., I.Popchev. New upper bounds for the CALE: A singular decomposition approach. - International Journal of Control and Automation Systems, vol. 6, No 2, pp.288-294, 2008, ISSN: 1598-6446.
  4. Savov, Sv., I. Popchev. New generalized upper trace bound for the solution of the Lyapunov equation. - Int. J. Pure and Appl. Math., vol. 49, No. 3, 2008, pp. 381-389.
  5. Savov, S., I.Popchev. On the degree of polynomial in the uncertainty valid Lyapunov functions for polytopic systems. - Compt. Rend. Acad. Bulg. Sci., vol. 61, No 10, pp.1335-1338, 2008, ISSN: 1310-1331.
  6. Popchev, I., I. Radeva, A Decision Support Method for Investment Preference Evaluation, - “Cybernetics and Information Technologies”, vol. 1, 2006, p. 3–16.
  7. Angelova, V., M. Konstantinov. P. Petkov, I. Popchev: Perturbation analysis for the complex matrix equation . In: Proc. 16th IFAC World Congress Praha 2005, paper 02645, Mo-A01-TP/11.
  8. Savov S., I. Popchev. The continuous algebraic Lyapunov’s equation. Lower and upper matrix bounds. - Compt. Rend. Acad. Bulg. Sci., 58, No 9, 2005, 1039-1042.
  9. Savov S., I. Popchev. Discrete algebraic Lyapunov’s equation. Lower and upper matrix bounds. - Compt. Rend. Acad. Bulg. Sci., 58, No 10, 2005, 1159-1162.
  10. Popchev I., I. Radeva. An Investment Preference Under Incomplete Data. - In: Proceedings DECOM-TT 2004, Automatic Systems for Bulding the Infrastructure in Developing Countries, Regional and Global Aspects (Bansko, Bulgaria October 3-5, 2004), 2004, 243-248.
  11. Savov S., I. Popchev. New Upper Estimates for the Solution of the Continuous Algebraic Lyapunov Equation. - IEEE Transactions on Automatic Control, vol.49, No 10, October, 2004, 1841-1842.
  12. Savov S., I. Popchev. Stability Analysis of Uncertain Matrices via Parametrised Interval System of Equations. - Compt.Rend.Acad.Bulg.Sci., 57, No 6, 2004, 67-70.
  13. Savov S., I. Popchev. On the Stability Analysis on Uncertain Systems via Parameter Dependent Lyapunov Function. - Cybernerics and Information Technologies, vol.4, No 1, 2004, 35-42.
  14. Konstantinov, M., V. Angelova, P. Petkov, D. Gu, V. Tsachouridis. Perturbation bounds for coupled matrix Riccati equations. - Lin. Alg. Appl., 359 (2003), 197-218.
  15. Angelova, V., Matrix calculus in control theory. Expansion and estimation for the matrix power (A+E)-k. - Comptes rendues de l'Academie bulgare des sciences, Technique, Theorie des systemes, 56, No 8, 2003, 35-38.
  16. Angelova, V., Perturbation analysis for the complex linear matrix equation . - Comptes rendues de l'Academie bulgare des sciences, Technique, Theorie des systemes, 56, No 12, 2003, 47-52.
  17. Angelova, V., Perturbation analysis for the matrix equation . In: Ann. Inst. Arch. Genie Civil Geod., 41 (2000-2001),2003, fasc. II Math., 33-41.
  18. Konstantinov, M., V. Angelova, P. Petkov, I. Popchev: Comparison of perturbation bounds for the matrix equation . In: Ann. Inst. Arch. Genie Civil Geod., 41 (2000-2001),2003, fasc. II Math., 75-82.
  19. Savov S. G. and I. Popchev. On the stability problem for a class of uncertain matrices. - Compt. Rend. Acad. Bilg. Sci, 54, No 5, 2003.
  20. Savov S. G. and I. Popchev. Robust stability analysis of continuous-time systems via generalized uncertain Lyapunov's matrices. - Compt. Rend. Acad. Bilg. Sci, 56, No 2, 2003, pp. 55-58.
  21. Savov S. G. and I. Popchev. Unrestricted parameter-dependent Lyapunov's function for robust stability analysis. - Information Technologies and Control, No 1, 2003, pp. 32-38.
  22. Konstantinov, M., V. Angelova, P. Petkov, D. Gu, V. Tsachouridis: Perturbation analysis of coupled matrix Riccati equations. In: Proc. 15 IFAC World Congr., Barcelona 2002, paper 572, T-Tu-E15.
  23. Savov S. G. and I. Popchev. Robust stability of uncertain discrete-time state-space models. - Compt. Rend. Acad. Bulg. Sci, 55, No 6, 2002, pp. 35-38.
Decision making under uncertainty in a fuzzy environment
  1. Peneva, V., I.Popchev. Fuzzy criteria importance with weighting functions. -Compt. Rend. Acad. Bulg. Sci., 61 (3), 2008, 293-300.
  2. Peneva, V., I.Popchev. Fuzzy criteria importance depending on the membership degrees of fuzzy relations. - Compt. Rend. Acad. Bulg. Sci., 61 (5), 2008, 579-584.
  3. Peneva, V., I.Popchev. Multicriteria decision making based on fuzzy relations. - Cybernetics and Information Technologies 8 (4), 2008, pp. 3-12, ISSN: 1311-9702.
  4. Popchev I., P. Georgieva. A fuzzy approach to solving multicriteria investment problems. In: M. Iskander (Edr), Innovative Techniques in Instruction Technology, E-learning, E-assessment and Education, Springer Science+Business Media B.V., pp. 427-431, 2008,ISBN: 978-1-4020-8738-7.
  5. Peneva, V., I.Popchev. Aggregation of fuzzy relations with fuzzy weighted coefficients. - Advanced Studies in Contemporary Mathematics, 15 (1), 2007, 121-132.
  6. Peneva, V., I.Popchev. Aggregation of fuzzy relations using weighting function. - Compt. Rend. Acad. Bulg. Sci., 60 (10), 2007, 1047-1052.
  7. Peneva, V., I.Popchev. Aggregation of fuzzy relations to multicriteria decision making. - Fuzzy Optimization and Decision Making, 6 (4), Dec. 2007, pp. 351-365.
  8. Popchev I., I. Radeva, Multi-Criteria Scheme for MAP-Cluster Identification. - Problems of Engineering Cybernetics and Robotics, vol. 58, pp. 3-12, 2007 ISSN: 0204-9848.
  9. Peneva V., I. Popchev. Models of decision making support by multicriteria problems in fuzzy environment. - Advanced Studies in Contemporary Mathematics 12 (2), 2006, 291-308.
  10. Peneva V., I. Popchev. Aggregation of fuzzy preference relations by composition. - Compt. Rend. Acad. Bulg. Sci., 59, No 4, 2006, 373-380.
  11. Peneva V., I. Popchev. Weighted transformation in aggregation operators uniting fuzzy relations. - Advanced Studies in Contemporary a Mathematics 10 (1), 2005, 25-44.
  12. Peneva V., I. Popchev. Aggregation of fuzzy preference relations with different importance. - Compt. Rend. Acad. Bulg. Sci., 58, No 5, 2005, 499-506.
  13. Peneva V., I. Popchev. Transformations by parameterized t-norms preserving the properties of fuzzy relations. – Compt.Rend.Acad.Bulg.Sci., 57, No 10, 2004, 9-18.
  14. Peneva V., I. Popchev. Fuzzy Decisions in Soft Computing. - In: Proceedings 2004 2-nd International IEEE Conference "Intelligent Systems" (Varna, Bulgaria, June 22-24, 2004), vol. II, 2004, 606-609.
  15. Peneva V., I. Popchev. Properties of fuzzy relations obtained by aggregation operators. - Compt. Rend. Acad. Bulg. Sci., 56, No 1, 2003, 9-16.
  16. Peneva V., I. Popchev. Weighted aggregation of fuzzy relations. - Compt. Rend. Acad. Bulg. Sci., 56, No 10, 2003, 29-35.
  17. Peneva V., I. Popchev. Properties of the aggregation operators related with fuzzy relations. - Fuzzy Sets and Systems, 139, No 3, 2003, 615-633.
  18. Peneva V., I. Popchev. Fuzzy multicriteria decision making. - Cybernetics and Information Technologies, Bulgarian Academy of Sciences, 2, No 1, 2002, 16-26.
  19. Peneva V., I. Popchev, Sensitivity of fuzzy logic operators. - Compt. Rend. Acad. Bulg. Sci., 55, No 3, 2002, 45-50.
  20. Peneva V., I. Popchev. Aggregation of fuzzy numbers in a decision making situation. - Cybernetics and Systems, 32, No 8, 2001, 821-835.
  21. Peneva V., I.Popchev, Aggregation of fuzzy relations in multicriteria decision making. - Compt. Rend. Acad. Bulg. Sci., 54, No 4, 2001, 47-52.
Software engineering
  1. Stoyanov, St., V. Valkanova, I. Popchev, I. Minov. A scenario-based approach for the creation of a virtual environement for secondary school instruction. - Cybernetics and Information Technologies 8 (3), pp. 86-96, 2008, ISSN: 1311-9702.
  2. Stoyanov, St., I. Ganchev, I. Popchev, M. O’Droma, An approach to the development of infostation-based elearning architectures. - Compt. Rend. Acad. Bulg. Sci., vol. 61, No 9, pp. 1189-1196, 2008, ISSN: 1310-1331.
  3. Stojanov, S., R. Vlahova, Linguistic Database in an Intelligent Portal for Education and Information (“Found in the Net”), In: Proc. of the 6th International Conference Formal Approaches to South Slavic and Balkan Languages, 25-28 September 2008, Dubrovnik, Croatia, pp.115-120, 2008, ISBN 978-953-55375-0-2.
  4. Popchev, I., N. Velinova. Software decision for neutral portfolio of securities, - Cybernetics and Information Technologies, vol. 1, 2005, pp. 14-34.
  5. Stoyanov S., I. Ganchev, I. Popchev, M. O'Droma. "From CBT to e-Learning". - Information Technologies and Control, No 4, 2005, pp 2-10.
  6. Ganchev I., S. Stojanov, M. O'Droma, I. Popchev. Enhancement of DeLC for the Provision of Intelligent Mobile Services. - In: Proceedings 2004 2-nd International IEEE Conference "Intelligent Systems" (Varna, Bulgaria, June 22-24, 2004), vol.I, 2004, 359-364.
  7. Stojanov S., I. Popchev, D.Chaushkova, M.Trendafilova. A Case Based Reasoning Approach for Development of Intelligent Services. - In: Proceedings of CompSysTech'04 the International Conference on computer Systems and Technologies (e-Learnig) (Rousse, Bulgaria, 17-18 June, 2004), 2004, v.7-1 - v.7-7.
  8. Stojanov S., I. Popchev, D.Chaushkova, M.Trendafilova. A Case Based Reasoning Approach for Development of Intelligent Services. – Information Technologies and Control, year II, 2004, No 3, 31-34.
  9. Popchev, I., N. Velinova. Application of Monte Carlo simulation in pricing of options, - Cybernetics and Information Technologies, vol. 2, 2003, pp. 74-91.
  10. Popchev, P., N. Velinova. Software programs and problems at investing options. – Cybernetics and Information Technologies, vol. 2, 2001, pp.34-55.
Soft computing
  1. Govedarova N., A Knowledge-Intensive Case Memory Model, in the Book of Abstracts, Poster Session of the Conference „Interdisciplinary College 2009”, pp. 10, 06-13 September 2009, Guenne, Germany (abstract)
  2. Govedarova N., S.Stoyanov, I.Popchev, An Ontology-Based CBR Architecture for Knowledge Management in BULCHINO Catalogue, In Proc. of the International Conference “Computer Systems and Technologies 2008”, pp.V5.1-V5.6, 12-13 June, Gabrovo, ISBN 978-954-9641-52-3 (best paper award)
  3. Govedarova N., S.Stoyanov, I.Popchev, Hybrid Ontology and CBR-Based Search in BULCHINO Catalogue, In Proc. of the International Conference “Informatics in the Scientific Knowledge 2008”, pp. 205-216, 26-28 June, Varna, ISSN 1313-4345
  4. Stoyanov S., N.Govedarova, I.Popchev, A Knowledge-Intensive CBR Application for Content-Based Retrieval in BULCHINO Catalogue, In Proc. of the Conference "Concurrency, Specification and Programming `2008", Vol.1, pp. 168-180, Gross Vaeter, Germany, 29 September - 1 October, ISSN 0863-095X
  5. Stoyanov S., N.Govedarova, I.Popchev, CBR-Based Search in BULCHINO Catalogue, In Proc. of the Conference "Concurrency, Specification and Programming `2007", Vol.2, pp. 521-533, 27-29 September 2007, Lagow, Poland

Last update: May, 2009.