DSpace Community:http://dspace.ewha.ac.kr/handle/2015.oak/1716922018-04-26T19:23:02Z2018-04-26T19:23:02ZStochastic ordering for populations of manufactured items차지환http://dspace.ewha.ac.kr/handle/2015.oak/2426072018-04-25T08:13:45Z2018-01-01T00:00:00ZTitle: Stochastic ordering for populations of manufactured items
Ewha Authors: 차지환
Abstract: We develop a theory of stochastic orders for the age and the residual (remaining) lifetime for populations of manufactured identical items. The obtained theoretical results can be used by manufacturers or users for the justified decisions with respect to, e.g., the increase or decrease in the production rate or with respect to the necessary maintenance actions. Specifically, we show that if the random age of a population is smaller (resp. larger) in some stochastic sense than the defined equilibrium age, then it is also smaller (resp. larger) than the corresponding residual lifetime with respect to different stochastic orders. We discuss various stochastic comparisons between the random age and the residual lifetime for one or more populations. Some ageing properties of the random age and the residual lifetime have also been studied.2018-01-01T00:00:00ZOn stochastic comparisons for population age and remaining lifetime차지환http://dspace.ewha.ac.kr/handle/2015.oak/2426052018-04-25T08:13:45Z2018-01-01T00:00:00ZTitle: On stochastic comparisons for population age and remaining lifetime
Ewha Authors: 차지환
Abstract: First, we consider items that are incepted into operation having already a random (initial) age and define the corresponding remaining lifetime. We show that these random variables are identically distributed when the age distribution is equal to the equilibrium distribution of the renewal theory. Then we consider real populations of items that were incepted into operation (were born) at different instants of time and obtain some useful inequalities between the population age and the remaining lifetime using reasoning similar to that employed in population studies. We also discuss the aging properties of populations using different stochastic orders.2018-01-01T00:00:00ZConvergence Analysis in the Maximum Norm of the Numerical Gradient of the Shortley-Weller Method민조홍http://dspace.ewha.ac.kr/handle/2015.oak/2426002018-04-25T08:13:44Z2018-01-01T00:00:00ZTitle: Convergence Analysis in the Maximum Norm of the Numerical Gradient of the Shortley-Weller Method
Ewha Authors: 민조홍
Abstract: The Shortley-Weller method is a standard central finite-difference-method for solving the Poisson equation in irregular domains with Dirichlet boundary conditions. It is well known that the Shortley-Weller method produces second-order accurate solutions and it has been numerically observed that the solution gradients are also second-order accurate; a property known as super-convergence. The super-convergence was proved in the norm in Yoon and Min (J Sci Comput 67(2):602-617, 2016). In this article, we present a proof for the super-convergence in the norm.2018-01-01T00:00:00ZA characterization of binormal matrices고응일http://dspace.ewha.ac.kr/handle/2015.oak/2425952018-04-25T08:13:43Z2018-01-01T00:00:00ZTitle: A characterization of binormal matrices
Ewha Authors: 고응일
Abstract: We give a characterization of binormal operator matrices, and in particular, a description of nxn binormal Toeplitzmatrices for n = 2, 3. Non-trivial examples of binormalmatrices that are not normal are also provided.2018-01-01T00:00:00Z