DSpace Collection: Scientific Reports
http://hdl.handle.net/10525/3204
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Operational Calculus Approach for Obtaining Periodic and Mean-periodic Solutions of Linear Ordinary Differential Equations with Constant Coefficients
http://hdl.handle.net/10525/4324
Title: Operational Calculus Approach for Obtaining Periodic and Mean-periodic Solutions of Linear Ordinary Differential Equations with Constant Coefficients<br/><br/>Authors: Dimovski, Ivan; Spiridonova, Margarita<br/><br/>Abstract: An approach to obtaining periodic and mean-periodic solutions of Linear Ordinary Dierential Equation (LODE) with constant coefficients is presented. The use of the Computer Algebra System (CAS) Mathematica for practical application of this approach is considered.<br/><br/>Description: [Dimovski Ivan H.; Димовски Иван Х.]; [Spiridonova Margarita; Спиридонова МаргаритаMonod-type Models with Nonlinear Birth Rate
http://hdl.handle.net/10525/3903
Title: Monod-type Models with Nonlinear Birth Rate<br/><br/>Authors: Ivanov, Tihomir B.; Velikova, Gergana V.<br/><br/>Abstract: We consider the classical Monod model and modify it by introducing generic growth rate for the biomass that is monotonically increasing with respect to the functional response. We show that this modification does not lead to qualitatively new possibilities for the model solutions. On the other hand, however, it allows better flexibility in terms of fitting experimental data. In particular, we use experimental data for microbial growth under inhibitory conditions, make parametric identification and show that the modified model performs far better than the classical one.<br/><br/>Description: [Ivanov Tihomir B.; Иванов Тихомир Б.]; [Velikova Gergana V.; Великова Гергана В.]On a Predator-Prey Type Model
http://hdl.handle.net/10525/3902
Title: On a Predator-Prey Type Model<br/><br/>Authors: Ivanov, Tihomir Bogoslovov<br/><br/>Abstract: In this paper we study a two-dimensional predator-prey type model, described by a system of nonlinear ordinary differential equations. We find the equilibrium points of the system and analyze their local and global stability with respect to the parameters of the model. Using the BifTools package in Maple, we analyze the bifurcations of the equilibrium points, as well. Some numerical simulations are presented to illustrate the analytically derived results.<br/><br/>Description: [Ivanov Tihomir Bogoslovov; Иванов Тихомир Богословов]BitTools: Maple Package for Bifurcation Analysis of Dynamical Systems
http://hdl.handle.net/10525/3901
Title: BitTools: Maple Package for Bifurcation Analysis of Dynamical Systems<br/><br/>Authors: Borisov, Milen Kolev<br/><br/>Abstract: This paper presents the Maple package "BifTools" for symbolic study of one and two parameter local bifurcations of equilibrium points. The package is applied to investigating models of biological processes.<br/><br/>Description: [Borisov Milen Kolev; Борисов Милен Колев]Classification of Griesmer Codes and Dual Transform
http://hdl.handle.net/10525/3900
Title: Classification of Griesmer Codes and Dual Transform<br/><br/>Authors: Bouyukliev, Iliya G.<br/><br/>Abstract: In this work, we consider a classification of infinite families of linear codes which achieve the Griesmer bound, using the projective dual transform. We investigate the correspondence between families of linear codes with given properties via dual transform.<br/><br/>Description: [Bouyukliev Iliya G.; Буюклиев Илия Г.]Commutants of the Euler Operator and Corresponding Mean-Periodic Functions
http://hdl.handle.net/10525/3899
Title: Commutants of the Euler Operator and Corresponding Mean-Periodic Functions<br/><br/>Authors: Dimovski, Ivan H.; Hristov, Valentin Z.<br/><br/>Description: [Dimovski Ivan H.; Dimovski Ivan Hristov; Димовски Иван Христов]; [Hristov Valentin Z.; Hristov Valentin Zdravkov; Христов Валентин Здравков]Prime Number Theorem, Gamma and Zeta function
http://hdl.handle.net/10525/3898
Title: Prime Number Theorem, Gamma and Zeta function<br/><br/>Authors: Apostolova, Lilia N.; Petrov, Kalin P.<br/><br/>Abstract: Some historical remarks on the subject are included in the beginning. In Part one a proof of the Prime Number Theorem following Zagier’s exposition [1997] of Neuman proof [1980]and Korevaar [1982] survey paper is given. The difference here are some changes in the proofs of different steps. In Part two the definitions and some properties of Gamma function and Riemann zeta-function are given. A proof that Prime number Theorem implies nonexistence of zeros of the Riemann zeta-function on the line of complex numbers with real part equal to one is given in this section. In the end of each part some valuable results from 1962, 1975 and 2004 included.<br/><br/>Description: [Apostolova Lilia N.; Апостолова Лилия Н.]; [Petrov Kalin P.; Петров Калин П.]Commutants of the Pommiez Operator
http://hdl.handle.net/10525/3897
Title: Commutants of the Pommiez Operator<br/><br/>Authors: Dimovski, Ivan H.; Hristov, Valentin Z.<br/><br/>Description: [Dimovski Ivan H.; Dimovski Ivan Hristov; Димовски Иван Христов]; [Hristov Valentin Z.; Hristov Valentin Zdravkov; Христов Валентин Здравков]On the Binary Projective Codes with Dimensions 6
http://hdl.handle.net/10525/3896
Title: On the Binary Projective Codes with Dimensions 6<br/><br/>Authors: Bouyukliev, Iliya<br/><br/>Abstract: All binary projective codes of dimension up to 6 are classified. Information about the number of the codes with different minimum distances and different orders of automorphism groups is given.<br/><br/>Description: [Bouyukliev Iliya; Буюклиев Илия]Няколко хронологични проблема в "Историята" на Лъв Дякон
http://hdl.handle.net/10525/3895
Title: Няколко хронологични проблема в "Историята" на Лъв Дякон<br/><br/>Authors: Табов, Йордан<br/><br/>Description: [Tabov Jordan; Табов Йордан]Directional Continuity and Upper Semi-Continuity in Differential Inclusions
http://hdl.handle.net/10525/3894
Title: Directional Continuity and Upper Semi-Continuity in Differential Inclusions<br/><br/>Authors: Ivanov, R. P.; Kitanov, N. M.<br/><br/>Abstract: An existence theorem is proved for solutions of autonomous differential inclusions with an upper semicontinuous and nonconvex right-hand side. The proof is based on an inner and directional continuous parameterization. The solution is obtained as a limit of disturbed systems solutions. An example of differential equiation with discontinuous right-hand side is considered. AMS (MOS) subject classification. 34A60.<br/><br/>Description: [Ivanov R. P.; Иванов Р. П.]; [Kitanov N. M.; Китанов Н. М.]Нелокальные операционные исчисления
http://hdl.handle.net/10525/3893
Title: Нелокальные операционные исчисления<br/><br/>Authors: Димовски, Иван Христов<br/><br/>Description: [Dimovski Ivan Hristov; Димовски Иван Христов]Some Remarks on a Theorem of H.-J. Schmidt
http://hdl.handle.net/10525/3892
Title: Some Remarks on a Theorem of H.-J. Schmidt<br/><br/>Authors: Barov, Stoyu; Dimov, George; Nedev, Stoyan<br/><br/>Abstract: On the basis of a property of the hyperspace, H.-J. Schmidt [S] introduced implicitly a class of spaces called in the present paper HS-spaces. In [S, Theorem 11(3d)] it is stated that every Hausdorff HS-space is regular. Later on M. Paoli and E. Ripoli noted in [PR1] that the proof of the above assertion is incorrect, but the question of the correctness of the statement is open. We give a partialsolution of this problem introducing a large class of spaces, which contains all Hausdorff spaces with countable character, where the theorem holds. Two reduction theorems are obtained as well. 1991 AMS Subj. Class.: primary – 54B20, 54CO5, 54D10, 54D15; secondary – 54B05, 54C10, 54G99.<br/><br/>Description: [Barov Stoyu; Баров Стою]; [Dimov George; Димов Георги]; [Nedev Stoyan; Недев Стоян]Българското присъствие на страниците на реферативното списание Mathematical Reviews
http://hdl.handle.net/10525/3891
Title: Българското присъствие на страниците на реферативното списание Mathematical Reviews<br/><br/>Authors: Дончев, А. Л.; Кендеров, П. Cт.<br/><br/>Description: [Donchev A. L.; Дончев А. Л.]; [Kenderov P. St.; Кендеров П. Cт.]Chaotic attractor reconstruction and applications in astronomy
http://hdl.handle.net/10525/3890
Title: Chaotic attractor reconstruction and applications in astronomy<br/><br/>Authors: Kirov, Nikolai K.; Parchomenko, Tatiana V.<br/><br/>Description: [Kirov Nikolai K.; Киров Николай К.]; [Parchomenko Tatiana V.; Пархоменко Татяна В.]Peano Continua Generating Densely Multivalued Metric Projections
http://hdl.handle.net/10525/3889
Title: Peano Continua Generating Densely Multivalued Metric Projections<br/><br/>Authors: Zhivkov, N. V.<br/><br/>Abstract: AMS (1991) - Mathematics Subject Classification: 41A65, 54F15, 52A30, 54E52.<br/><br/>Description: [Zhivkov N. V.; Живков Н. В.]