Журнал прикладной и вычислительной математики

In this paper, we develop an efficient Chebyshev wavelet method for well-known one-dimensional heat equation. In the proposed method we applied operational matrices of integration to get numerical solution of the onedimensional heat equation with Dirichlet boundary conditions. The power of this manageable method is confirmed. Moreover the use of Chebyshev wavelet is found to be accurate, simple and fast.

This paper presents an EOQ model with constant demand rate for non deteriorating items where shortages are allowed. In this paper shortages are considered as completely backlogged. The production rate is assumed to be proportional to demand rate and finite. The optimal solution of the model has been done for finding optimal time, optimal average cost by considering four different situations. Numerical example and sensitivity analysis is given to illustrate the proposed model.

This work is aimed to obtain the complex partial fraction decompositions of rational functions. We express the coefficients of complex partial fraction decomposition of arbitrary rational functions in terms of the coefficients of their real partial fraction decomposition. This type of decompositions is then used to generalize the high order derivatives of such rational functions. Moreover, different applications are selected to demonstrate the applicability of introduced algorithms.

This paper presents the economic ordering policies of linearly time-dependent deteriorating items with an exponential demand rate in the presence of trade credit using Discount Cash Flow (DCF) approach. Mathematical models are derived under two different situations: Case (1) Instantaneous cash flows, and Case (2) Fixed credit period. The expressions for on inventory systems present the value of all future cash flows are derived for these two cases. The main purpose of this paper is to obtain the optimal (minimum) present values of all future cash flows for both cases. The sensitivity analysis is given for the applicability of the purposed model. Mathematical software is used for finding numerical values of optimal cycle time with different discount rate and different credit period.

In contrast to the classical boundary layer approach which is not uniquely solvable at the irregular wave numbers, the modified layer method always has a unique solution to the exterior boundary problem for the vector Helmholtz equation. We compare the stability of the two methods numerically.