DSpace Collection: 2019 Volume 30
http://hdl.handle.net/10525/3606
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On the Decay of Solutions to a Class of Hartree Equations
http://hdl.handle.net/10525/3624
Title: On the Decay of Solutions to a Class of Hartree Equations<br/><br/>Authors: Tarulli, Mirko; Venkov, George<br/><br/>Abstract: 2010 Mathematics Subject Classification: 35Q55, 34G20, 35P25.<br/><br/>Description: [Venkov George; Венков Георги]Switch-Time Distributions and Processes
http://hdl.handle.net/10525/3623
Title: Switch-Time Distributions and Processes<br/><br/>Authors: Stoynov, Pavel<br/><br/>Abstract: A family of probability distributions and related to them processes known as Switch Time distributions and processes (ST distributions and processes) are presented and simulated. Here by switch time we denote the time of sharp change of value of a stochastic process (jump) or sharp change of some characteristics of a stochastic process (regime switch). 2010 Mathematics Subject Classification: 60G51, 97K60.<br/><br/>Description: [Stoynov Pavel; Стойнов Павел]Inverse Scattering by Obstacles and Santalo’s Formula
http://hdl.handle.net/10525/3622
Title: Inverse Scattering by Obstacles and Santalo’s Formula<br/><br/>Authors: Stoyanov, Luchezar<br/><br/>Abstract: We consider some problems related to recovering information about an obstacle K in an Euclidean space from certain measurements of lengths of generalized geodesics in the exterior of the obstacle – e.g. sojourn times of scattering rays in the exterior of the obstacle, or simply, travelling times of geodesics within a certain large ball containing the obstacle. It is well-known in scattering theory that this scattering data is related to the singularities of the scattering kernel of the scattering operator for the wave equation in the exterior of K with Dirichlet boundary condition on the boundary. For some classes of obstacles, K can be completely recovered from the scattering data. On the other hand, for some obstacles the set of trapped points is too large and this makes it impossible to recover them from scattering data. We discuss also a certain stability property of the trapping set, which is obtained from a generalisation of Santalo’s formula to integrals over billiard trajectories in the exterior of an obstacle. Some other applications of this formula to scattering by obstacles are discussed as well. 2010 Mathematics Subject Classification: 37D40, 37D50, 53D25, 58J50.<br/><br/>Description: [Stoyanov Luchezar; Стоянов Лъчезар]CNN Modeling of a Class of Integro-Differential Equations
http://hdl.handle.net/10525/3621
Title: CNN Modeling of a Class of Integro-Differential Equations<br/><br/>Authors: Slavova, Angela; Zafirova, Zoya; Zecca, Pietro<br/><br/>Abstract: In this paper we study a class of integro-differential equations. First we present Cellular Nonlinear Networks (CNN) modeling of integro-differential equations. We map the equation under consideration into CNN architecture and study its dynamics. Applying harmonic balance method we obtain periodic solutions of the model. We provide numerical simulations which illustrate the obtained theoretical results. 2010 Mathematics Subject Classification: 92B20, 35B10, 35Q68, 35Q92.<br/><br/>Description: [Slavova Angela; Славова Анжела]; [Zafirova Zoya; Зафирова Зоя]Dynamics of PEM with Nano-Inhomogeneities via Cellular Nanoscale Networks
http://hdl.handle.net/10525/3620
Title: Dynamics of PEM with Nano-Inhomogeneities via Cellular Nanoscale Networks<br/><br/>Authors: Slavova, Angela; Bobeva, Galina<br/><br/>Abstract: In this paper we study the dynamics of piezoelectrical material (PEM) with nano-inhomogeneities. The boundary value model defined by the system of two partial differential equations and the boundary conditions for the generalized stress is mapped into Cellular Nanoscale Networks architecture. We study the dynamics of the obtained CNN model via harmonic balance technique. Validation and simulations are provided which illustrate the theoretical results. 2010 Mathematics Subject Classification: 92B20,74F15, 35K57, 35Q68.<br/><br/>Description: [Slavova Angela; Славова Анжела]; [Bobeva Galina; Бобева Галина]Oscillation of a Circular Cylinder Subject to Water Jet
http://hdl.handle.net/10525/3619
Title: Oscillation of a Circular Cylinder Subject to Water Jet<br/><br/>Authors: Mochimaru, Yoshihiro<br/><br/>Abstract: Oscillation of a circular cylinder subject to water jet is analyzed theoretically, taking into outgoing film flow followed by hydraulic jump, which is considered to be almost similar to oblique impingement of a circular jet to a flat surface. Observed translation and rotation of the cylinder is in good agreement with the analysis. 2010 Mathematics Subject Classification: 33E05, 34A34, 34A45, 34C15, 34C25.Estimates in Morrey-Campanato Spaces of a Suitable Weak Solution of the Navier-Stokes Equations, Satisfying an Extra-Condition
http://hdl.handle.net/10525/3618
Title: Estimates in Morrey-Campanato Spaces of a Suitable Weak Solution of the Navier-Stokes Equations, Satisfying an Extra-Condition<br/><br/>Authors: Mauro, Jimmy Alfonso<br/><br/>Abstract: We consider a study of regularity, by means of the theory of Morrey-Campanato spaces, of suitable weak solutions of the Cauchy problem for the non-stationary Navier-Stokes equations, which satisfy a suitable extra-condition. According to what is known at the moment, the extra-conditions which we consider don’t assure the regularity of the suitable weak solution. 2010 Mathematics Subject Classification: 76D05, 35Q30, 76D03.A Note on the Dagum–II Sigmoid Function with Applications to Wealth Data. Other Applications
http://hdl.handle.net/10525/3617
Title: A Note on the Dagum–II Sigmoid Function with Applications to Wealth Data. Other Applications<br/><br/>Authors: Kyurkchiev, Nikolay; Iliev, Anton<br/><br/>Abstract: 2010 Mathematics Subject Classification: 41A46.<br/><br/>Description: [Kyurkchiev Nikolay; Кюркчиев Николай]; [Iliev Anton; Илиев Антон]Orbital Stability of Solitary Waves to Fourth Order Dispersive Equations with Quadratic Nonlinearity
http://hdl.handle.net/10525/3616
Title: Orbital Stability of Solitary Waves to Fourth Order Dispersive Equations with Quadratic Nonlinearity<br/><br/>Authors: Kolkovska, N.; Dimova, M.; Kutev, N.<br/><br/>Abstract: 2010 Mathematics Subject Classification: 35B44, 35L75.<br/><br/>Description: [Kolkovska N.; Кольковска Н.]; [Dimova M.; Димова М.]; [Kutev N.; Kutev Nikolai; Кутев Николай]On an Example of Derivative Nonlinear Schrödinger Equation with D2 Reduction
http://hdl.handle.net/10525/3615
Title: On an Example of Derivative Nonlinear Schrödinger Equation with D2 Reduction<br/><br/>Authors: Gerdjikov, V. S.; Stefanov, A. A.<br/><br/>Abstract: 2010 Mathematics Subject Classification: 35Q15, 31A25, 37K10, 35Q58.<br/><br/>Description: [Gerdjikov V. S.; Герджиков В. С.]; [Stefanov A. A.; Stefanov A. Aleksander; Стефанов А. Александър]The Boson Star Equation with Hartree Type Non-Linearity: Global Existence in H^1/2(R^2 )
http://hdl.handle.net/10525/3614
Title: The Boson Star Equation with Hartree Type Non-Linearity: Global Existence in H^1/2(R^2 )<br/><br/>Authors: Georgiev, Vladimir; Shakarov, Boris<br/><br/>Abstract: 2010 Mathematics Subject Classification: 35Q55, 35Q85, 42B37.<br/><br/>Description: [Georgiev Vladimir; Георгиев Владимир]; [Shakarov Boris; Шакаров Борис]Remark on the Global Non-Existence of Semirelativistic Equations with Non-Gauge Invariant Power Type Nonlinearity with Mass
http://hdl.handle.net/10525/3613
Title: Remark on the Global Non-Existence of Semirelativistic Equations with Non-Gauge Invariant Power Type Nonlinearity with Mass<br/><br/>Authors: Fujiwara, Kazumasa<br/><br/>Abstract: The non-existence of global solutions for semirelativistic equations with nongauge invariant power type nonlinearity with mass is studied in the frame work of weighted L^1 . In particular, a priori control of weighted integral of solutions is obtained by introducing a pointwise estimate of fractional derivative of some weight functions. Especially, small data blowup with small mass is obtained. 2010 Mathematics Subject Classification: 35Q40.Modified FVK Model
http://hdl.handle.net/10525/3612
Title: Modified FVK Model<br/><br/>Authors: Del Corso, G.; Georgiev, V.<br/><br/>Abstract: This paper considers a generalization of Föppl–von Kärmán model for elastic plate depending on a parameter σ. We prove global well posedness for the Cauchy problem with small initial data and σ = 1 via Strichartz estimate for vibrating plate and Riesz transform. We generalize this result to a perturbed version of the original case (σ = 2) with the use of Yukawa potential. 2010 Mathematics Subject Classification: 35J50, 35Q40, 35J45.<br/><br/>Description: [Georgiev V.; Георгиев В.]Existence of Classical Solutions of Linear Non-Cooperative Elliptic Systems
http://hdl.handle.net/10525/3611
Title: Existence of Classical Solutions of Linear Non-Cooperative Elliptic Systems<br/><br/>Authors: Boyadzhiev, G.; Kutev, N.<br/><br/>Abstract: 2010 Mathematics Subject Classification: 35J47, 35J57.<br/><br/>Description: [Boyadzhiev G.; Бояджиев Г.]; [Kutev N.; Кутев Н.]Recent Developments of the Methodology of the Modified Method of Simplest Equation with Application
http://hdl.handle.net/10525/3610
Title: Recent Developments of the Methodology of the Modified Method of Simplest Equation with Application<br/><br/>Authors: Vitanov, Nikolay K.<br/><br/>Abstract: We discuss an extension of the modified method of simplest equation for obtaining exact analytical solutions of nonlinear partial differential equations. The extension includes the possibility for use of: (i) more than one simplest equation; (ii) relationship that contains as particular cases the relationship used by Hirota [1] and the relationship used in the previous version of the methodology; (iii) transformation of the solution that contains as particular case the possibility of use of the Painleve expansion; (iv) more than one balance equation. The discussed version of the methodology allows: obtaining multi-soliton solutions of nonlinear partial differential equations if such solutions do exist and obtaining particular solutions of nonintegrable nonlinear partial differential equations. Examples for the application of the methodology are discussed. 2010 Mathematics Subject Classification: 35E20.<br/><br/>Description: [Vitanov Nikolay K.; Витанов Николай К.]Gromov Hyperbolicity of the Kobayashi Metric
http://hdl.handle.net/10525/3609
Title: Gromov Hyperbolicity of the Kobayashi Metric<br/><br/>Authors: Andreev, Lyubomir; Nikolov, Nikolai; Trybula, Maria<br/><br/>Abstract: In this paper we discuss the global geometry of the Kobayashi metric on domains in C^n. We gather all known results. We pay special attention to methods which distroy the hyperbolicity. 2010 Mathematics Subject Classification: 32F45, 53C23.<br/><br/>Description: [Andreev Lyubomir; Андреев Любомир]; [Nikolov Nikolai; Николов Николай]