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251.
We study a dynamic inventory and pricing optimization problem in a periodic review inventory system with setup cost and finite ordering capacity in each period. We show that the optimal inventory control is characterized by an (s,s′,p) policy in four regions of the starting inventory level. 相似文献
252.
We are concerned with an inverse problem for a degenerate linear evolution equation of first-order. Both hyperbolic and parabolic cases will be considered. We indicate sufficient conditions for the existence and uniqueness of a solution. All the results can be applied to inverse problems for equations from mathematical physics. As a possible application of the abstract theorems, some examples of partial differential equations are given. 相似文献
253.
Won Keun Min 《Applied Mathematics Letters》2012,25(3):310-314
We introduce and study the concept of similarity between soft sets, which is an extension of the equality for soft set theory. We also introduce the concepts of conjunction parameter (α∧β) and disjunction parameter (α∨β) of ordered pair parameter 〈α,β〉 for soft set theory, and we investigate modified operations of soft set theory in terms of ordered parameters. 相似文献
254.
R. Naz 《Applied Mathematics Letters》2012,25(3):257-261
This paper is an application of the variational derivative method to the derivation of the conservation laws for partial differential equations. The conservation laws for (1+1) dimensional compacton k(2,2) and compacton k(3,3) equations are studied via multiplier approach. Also the conservation laws for (2+1) dimensional compacton Zk(2,2) equation are established by first computing the multipliers. 相似文献
255.
Wutiphol Sintunavarat Poom Kumam 《Applied Mathematics Letters》2012,25(1):52-57
In this paper, we introduce the notion of a hybrid generalized multi-valued contraction mapping and establish the common fixed point theorem for this mapping. Our results generalize, unify, extend and complement several common fixed point theorems of many authors in the literature. 相似文献
256.
基于USB的高清彩色CCD图像采集系统 总被引:1,自引:1,他引:0
提出一种基于USB的彩色CCD高清图像采集系统设计方案。图像数据的来源采用的是SONY公司的ICX205AK芯片,结合USB2.0接口,复杂可编程逻辑器件CPLD设计了一个高速的彩色CCD图像采集系统。文中详细阐述了系统内不同模块的硬件电路设计思路和软件运行流程。整个系统由电源系统、CCD传感器、A/D模数转换器、CPLD控制器、USB2.0高速接口、上位机控制程序等各个部分组成。本系统的硬件电路可以协调正常工作完成分辨率为140万的高清图像采集,最高采集帧率达7.5 frame/s。 相似文献
257.
258.
Bingchen LiuFengjie Li 《Nonlinear Analysis: Real World Applications》2012,13(2):764-778
This paper considers blow-up solutions for reaction-diffusion equations, complemented by homogeneous Dirichlet boundary conditions. It is proved that there exist initial data such that one block or two (separated or contiguous) blocks of n components blow up simultaneously while the others remain bounded. As a corollary, a necessary and sufficient condition is obtained such that any blow-up must be the case for at least two components blowing up simultaneously. We also show some other exponent regions, where any blow-up of k(∈{1,2,…,n}) components must be simultaneous. Moreover, the corresponding blow-up rates and sets are discussed. The results extend those in Liu and Li [B.C. Liu, F.J. Li, Non-simultaneous blow-up of n components for nonlinear parabolic systems, J. Math. Anal. Appl. 356 (2009) 215-231]. 相似文献
259.
An SIR epidemic model with state dependent pulse vaccination is proposed in this paper. Using the Poincaré map, the differential inequality and the method of qualitative analysis, we prove the existence and the stability of positive order-1 or order-2 periodic solution for this model. Moreover, we show that there is no periodic solution with order larger than or equal to three. Numerical simulations are carried out to illustrate the feasibility of our main results and the suitability of state dependent pulse vaccination is also discussed. 相似文献
260.
Exploring a recently developed mesoscale continuum theory of dislocation dynamics, we derive three predictions about plasticity and grain boundary formation in crystals. (1) There is a residual stress jump across grain boundaries and plasticity-induced cell walls as they form, which self-consistently acts to attract neighboring dislocations; residual stress in this theory appears as a remnant of the driving force behind wall formation under both polygonization and plastic deformation. We derive the predicted asymptotic late-time dynamics of the grain-boundary formation process. (2) During grain boundary formation at high temperatures, there is a predicted cusp in the elastic energy density. (3) In early stages of plasticity, when only one type of dislocation is active (single-slip), cell walls do not form in the theory; instead we predict the formation of a hitherto unrecognized jump singularity in the dislocation density. 相似文献