DSpace Collection: Volume 25 Number 4
http://hdl.handle.net/10525/430
Serdica Mathematical Journal Volume 25, Number 4, 1999The Collection's search engineSearch the Channelsearch
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Alternative Characterization of the Class k-UCV and Related Classes of Univalent Functions
http://hdl.handle.net/10525/455
Title: Alternative Characterization of the Class k-UCV and Related Classes of Univalent Functions<br/><br/>Authors: Kanas, Stanislawa<br/><br/>Abstract: In this paper an alternative characterization of the class offunctions called k -uniformly convex is found. Various relations concerningconnections with other classes of univalent functions are given. Moreover anew class of univalent functions, analogous to the ’Mocanu class’ of functions,is introduced. Some results concerning this class are derived.Fri, 01 Jan 1999 00:00:00 GMTNull Condition for Semilinear Wave Equation with Variable Coefficients
http://hdl.handle.net/10525/454
Title: Null Condition for Semilinear Wave Equation with Variable Coefficients<br/><br/>Authors: Catalano, Fabio<br/><br/>Abstract: In this work we analyse the nonlinear Cauchy problem (∂tt − ∆)u(t, x) = ( λg + O(1/(1 + t + |x|)^a) ) ) ∇t,x u(t, x), ∇t,x u(t, x) ), whit initial data u(0, x) = e u0 (x), ut (0, x) = e u1 (x). We assume a ≥ 1,x ∈ R^n (n ≥ 3) and g the matrix related to the Minkowski space. It can beconsiderated a pertubation of the case when the quadratic term has constantcoefficient λg (see Klainerman [6])We prove a global existence and uniqueness theorem for very regular initialdata. The proof avoids a direct application of Klainermann method (Nullcondition, energy conformal method), because the result is obtained by acombination beetwen the energy estimate (norm L^2 ) and the decay estimate(norm L^∞ ).<br/><br/>Description: ∗The author was partially supported by M.U.R.S.T. Progr. Nazionale “Problemi Non Lineari...”Fri, 01 Jan 1999 00:00:00 GMTA Cauchy Integral Related to a Robot-safety Device System
http://hdl.handle.net/10525/453
Title: A Cauchy Integral Related to a Robot-safety Device System<br/><br/>Authors: Vanderperre, E.; Makhanov, S.<br/><br/>Abstract: We introduce a robot-safety device system attended by twodifferent repairmen. The twin system is characterized by the natural featureof cold standby and by an admissible “risky” state. In order to analyse therandom behaviour of the entire system (robot, safety device, repair facility)we employ a stochastic process endowed with probability measures satisfyinggeneral Hokstad-type differential equations. The solution procedure isbased on the theory of sectionally holomorphic functions, characterized bya Cauchy-type integral defined as a Cauchy principal value in double sense.An application of the Sokhotski-Plemelj formulae determines the long-runavailability of the robot-safety device. Finally, we consider the particularbut important case of deterministic repair.Fri, 01 Jan 1999 00:00:00 GMTTopological Dichotomy and Unconditional Convergence
http://hdl.handle.net/10525/452
Title: Topological Dichotomy and Unconditional Convergence<br/><br/>Authors: Lefevre, Pascal<br/><br/>Abstract: In this paper, we give a criterion for unconditional convergencewith respect to some summability methods, dealing with the topological sizeof the set of choices of sign providing convergence. We obtain similar resultsfor boundedness. In particular, quasi-sure unconditional convergence impliesunconditional convergence.Fri, 01 Jan 1999 00:00:00 GMTRepresentations and Positive Definite Functions on Hypergroups
http://hdl.handle.net/10525/451
Title: Representations and Positive Definite Functions on Hypergroups<br/><br/>Authors: Nasr-Isfahani, A.<br/><br/>Abstract: Some relationships between representations of a hypergroup X,its algebras, and positive definite functions on X are studied. Also, varioustypes of convergence of positive definite functions on X are discussed.Fri, 01 Jan 1999 00:00:00 GMTA Differential Game Described by a Hyperbolic System
http://hdl.handle.net/10525/450
Title: A Differential Game Described by a Hyperbolic System<br/><br/>Authors: Souroujon, Diko<br/><br/>Abstract: An antagonistic differential game of hyperbolic type with aseparable linear vector pay-off function is considered. The main result isthe description of all ε-Slater saddle points consisting of program strategies, program ε-Slater maximins and minimaxes for each ε ∈ R^N > for this game. To this purpose, the considered differential game is reduced to findthe optimal program strategies of two multicriterial problems of hyperbolictype. The application of approximation enables us to relate these problemsto a problem of optimal program control, described by a system of ordinarydifferential equations, with a scalar pay-off function. It is found that theresult of this problem is not changed, if the players use positional or program strategies. For the considered differential game, it is interesting thatthe ε-Slater saddle points are not equivalent and there exist two ε-Slatersaddle points for which the values of all components of the vector pay-offfunction at one of them are greater than the respective components of theother ε-saddle point.Fri, 01 Jan 1999 00:00:00 GMT