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Динамическая модель организации грузоперевозок
Машинное обучение и анализ данных. 2015. Т. 1. № 13. С. 1815-1826.
Khachatryan N., Бекларян Л. А.
Khachatryan N., Бекларян Л. А., Журнал вычислительной математики и математической физики 2013 Т. 53 № 10 С. 1649-1667
A model is studied that describes the process of good transportation occurring in some technologies. Transportation regimes satisfying a given management system are examined. Such regimes are described by traveling-wave solutions to a nonlinear finite-difference analogue of a parabolic equation. Possible transportation regimes are described, and the stability of stationary regimes is analyzed. ...
Added: November 21, 2013
Zlotnik A., Romanova A., Applied Numerical Mathematics 2015 Vol. 93 P. 279-294
We consider an initial-boundary value problem for a 2D time-dependent Schrödinger equation on a semi-infinite strip. For the Numerov-Crank-Nicolson finite-difference scheme with discrete transparent boundary conditions, the Strang-type splitting with respect to the potential is applied. For the resulting method, the uniqueness of a solution and the uniform in time $L^2$-stability (in particular, $L^2$-conservativeness) together ...
Added: November 30, 2013
Ducomet B., Zlotnik A., Zlotnik I. A., / Cornell University. Series math "arxiv.org". 2013. No. arxiv: 1303.3471.
We consider an initial-boundary value problem for a generalized 2D time-dependent Schrödinger equation on a semi-infinite strip. For the Crank-Nicolson finite-difference scheme with approximate or discrete transparent boundary conditions (TBCs), the Strang-type splitting with respect to the potential is applied. For the resulting method, the uniform in time L2-stability is proved. Due to the ...
Added: March 16, 2013
Zlotnik A., Romanova A. V., / Cornell University. Series math "arxiv.org". 2013. No. arxiv: 1307.5398.
We consider an initial-boundary value problem for a 2D time-dependent Schrödinger equation on a semi-infinite strip. For the Numerov-Crank-Nicolson finite-difference scheme with discrete transparent boundary conditions, the Strang-type splitting with respect to the potential is applied. For the resulting method, the uniqueness of a solution and the uniform in time L_2-stability (in particular, L_2-conservativeness) are ...
Added: July 24, 2013
Zlotnik A., Zlotnik I. A., Доклады Академии наук 2011 Т. 436 № 1 С. 19-25
An initial–boundary value problem for the generalized Schrödinger equation in a semi-infinite strip is solved.
A new family of two level finite-difference schemes with averaging over spatial variables on a finite mesh is constructed, which covers a set of finite-difference schemes built using various methods. For the family, an abstract approximate transparent boundary condition (TBC) is ...
Added: July 5, 2012
Zlotnik A., Koltsova N., / Cornell University. Series math "arxiv.org". 2012. No. arXiv:1211.3613 [math.NA].
An initial-boundary value problem for the 1D self-adjoint parabolic equation on the half-axis is solved. We study a broad family of two-level finite-difference schemes with two parameters related to averagings both in time and space. Stability in two norms is proved by the energy method. Also discrete transparent boundary conditions are rigorously derived for schemes ...
Added: January 25, 2013
Злотник А.А., Лапухина А., Проблемы математического анализа 2010 № 47 С. 77-88
Нестационарное уравнение Шрёдингера относится к основным уравнениям математической физики и находит многочисленные приложения. Очень часто его приходится численно решать в неограниченных по пространству областях. Для этой цели разработан ряд подходов, связанных с постановкой искусственных или приближенных прозрачных граничных условий (ПГУ) на искусственных границах. Среди них следует выделить подход, использующий так называемые дискретные ПГУ. Серьезный практический ...
Added: December 22, 2015
Zlotnik A., Applied Mathematics Letters 2019 Vol. 92 P. 115-120
We deal with an explicit finite-difference scheme with a regularization for the 1D gas dynamics equations linearized at the constant solution. The sufficient condition on the Courant number for the $L^2$-dissipativity of the scheme is derived in the case of the Cauchy problem and a non-uniform spatial mesh. The energy-type technique is developed to this end, and ...
Added: January 20, 2019
Mishchenko A. V., Скоков А. А., Страховое дело 2012 № 9 С. 3-11
В работе рассмотрены целочисленные модели оценки эффективности финансовых портфелей с учетом неопределенности и риска. Предложены методы оценки устойчивости этих портфелей и методы ветвей и границ для определения оптимальных портфелей. ...
Added: February 23, 2014
Mishchenko A. V., Иванова А. В., Экономический анализ: теория и практика 2013 № 16 С. 52-68
В работе рассмотрены модели проектов расширения производства и методики оценки устойчивости и рисков этих проектов. ...
Added: February 23, 2014
Zlotnik A., Kireeva O., / Cornell University. Series arXiv "math". 2020. No. arXiv:2011.14104v2[math.NA].
We consider compact finite-difference schemes of the 4th approximation order for an initial-boundary value problem (IBVP) for the $n$-dimensional non-homogeneous wave equation, $n\geq 1$. Their construction is accomplished by both the classical Numerov approach and alternative technique based on averaging of the equation, together with further necessary improvements of the arising scheme for $n\geq 2$. The ...
Added: December 1, 2020
Khachatryan N., Akopov A. S., Business Informatics 2017 No. 1(39) P. 25-35
A model for organizing cargo transportation between two node stations connected by a railway line which contains a certain number of intermediate stations is considered. The movement of cargo is in one direction. Such a situation may occur, for example, if one of the node stations is located in a region which produce raw material ...
Added: April 18, 2017
Zlotnik A., Lapukhina A. V., Journal of Mathematical Sciences 2010 Vol. 169 No. 1 P. 84-97
We consider an initial-boundary value problem for the one-dimensional nonstationary Schrödinger equation on the half-axis and study a two-level symmetric finite-difference scheme of Numerov type with higher approximation order. This scheme is constructed on a finite mesh, which is uniform with respect to space, with a nonlocal approximate transparent boundary condition of a general form ...
Added: December 23, 2015
А. А. Злотник, Т. А. Ломоносов, Доклады Российской академии наук. Математика, информатика, процессы управления (ранее - Доклады Академии Наук. Математика) 2020 Т. 492 № 1 С. 31-37
We study an explicit two-level symmetric in space finite-difference scheme for the multi\-di\-men\-si\-onal barotropic gas dynamics system of equations with quasi-gasdynamic regulari\-za\-tion linearized at a constant solution (with arbitrary velocity). A criterion and both necessary and sufficient conditions for the $L^2$-dissipativity of the solutions to the Cauchy problem for the scheme are derived by the spectral ...
Added: March 4, 2020
Protasov V., Systems and Control Letters 2016 Vol. 90 P. 54-60
We prove the existence of positive linear switching systems (continuous time), whose trajectories grow to infinity, but slower than a given increasing function. This implies that, unlike the situation with linear ODE, the maximal growth of trajectories of linear systems may be arbitrarily slow. For systems generated by a finite set of matrices, this phenomenon ...
Added: February 22, 2016
Vexler B., Zlotnik A., Trautmann P., Comptes Rendus Mathematique 2018 Vol. 356 No. 5 P. 523-531
The paper deals with the optimal control problems governed by the 1D wave equation with variable coefficients and the control spaces of either measure-valued functions or vector measures. Bilinear finite element discretizations are constructed and their stability and error analysis is accomplished. ...
Added: April 8, 2017
Zlotnik Alexander, / Cornell University. Series math "arxiv.org". 2015.
We deal with an initial-boundary value problem for the generalized time-dependent Schr\"odinger equation with variable coefficients in an unbounded $n$--dimensional parallelepiped ($n\geq 1$). To solve it, the Crank-Nicolson in time and the polylinear finite element in space method with the discrete transpa\-rent boundary conditions is considered. We present its stability properties and derive new error ...
Added: March 27, 2015
Zlotnik Alexander, Zlotnik Ilya, Computational Methods in Applied Mathematics 2015 Vol. 15 No. 2 P. 233-245
We consider the Cauchy problem for the 1D generalized Schrὅdinger equation on the whole axis. To solve it, any order finite element in space and the Crank-Nicolson in time method with the discrete transpa\-rent boundary conditions (TBCs) has recently been constructed. Now we engage the global Richardson extrapolation in time to derive the high order ...
Added: March 3, 2015
Buzmakov A. V., Kuznetsov S., Napoli A., Procedia Computer Science 2014 Vol. 31 P. 918-927
There is a lot of usefulness measures of patterns in data mining. This paper is focused on the measures used in Formal Concept Analysis (FCA). In particular, concept stability is a popular relevancy measure in FCA. Experimental results of this paper show that high stability of a pattern in a given dataset derived from the ...
Added: October 22, 2015
Zlotnik Alexander, Zlotnik Ilya, / Cornell University. Series math "arxiv.org". 2014. No. arXiv:1405.3147.
We consider the Cauchy problem for the 1D generalized Schrödinger equation on the whole axis. To solve it, any order finite element in space and the Crank-Nicolson in time method with the discrete transpa\-rent boundary conditions (TBCs) has recently been constructed. Now we engage the Richardson extrapolation to improve significantly the accuracy in time step. ...
Added: May 14, 2014
Ducomet B., Zlotnik A., Romanova A. V., / Cornell University. Series math "arxiv.org". 2013. No. 1309.7280.
An initial-boundary value problem for the $n$-dimensional ($n\geq 2$) time-dependent Schrödinger equation in a semi-infinite (or infinite) parallelepiped is considered. Starting from the Numerov-Crank-Nicolson finite-difference scheme, we first construct higher order scheme with splitting space averages having much better spectral properties for $n\geq 3$. Next we apply the Strang-type splitting with respect to the potential ...
Added: October 1, 2013
Zlotnik A., Zlotnik I. A., Kinetic and Related Models 2012 Vol. 5 No. 3 P. 639-667
We consider the time-dependent 1D Schrödinger equation on the half-axis with variable coefficients becoming constant for large x. We study a two-level symmetric in time (i.e. the Crank-Nicolson) and any order finite element in space numerical method to solve it. The method is coupled to an approximate transparent boundary condition (TBC). We prove uniform in ...
Added: March 21, 2013
Zlotnik A., Čiegis R., Applied Mathematics Letters 2018 Vol. 80 P. 35-40
The stability bounds and error estimates for a compact higher order Numerov-Crank-Nicolson scheme on non-uniform spatial meshes for the 1D time-dependent Schrödinger equation have been recently derived. This analysis has been done in $L^2$ and $H^1$ mesh norms and used the non-standard ``converse'' condition $h_\omega\leq c_0\tau$, where $h_\omega$ is the mean spatial step, $\tau$ is ...
Added: January 6, 2018
Ducomet Bernard, Zlotnik Alexander, Romanova Alla, Applied Mathematics and Computation 2015 Vol. 255 P. 195-206
An initial-boundary value problem for the n -dimensional ($n\geq 2$) time-dependent Schrödinger equation in a semi-infinite parallelepiped is considered. Starting from the Numerov–Crank–Nicolson finite-difference scheme, we first construct higher order scheme with splitting space averages having much better spectral properties for $n\geq 3$. Next we apply the Strang-type splitting with respect to the potential and, third, construct discrete ...
Added: October 10, 2014