一类包含m—增生算子紧扰动的算子方程的可解性

设X为一致凸的Banach空间,T:X(?)D(T)→X为m—增生的且强增生的算子,T_0:X→X为线性紧算子。C:X→X为全连续算子,应用Leray-Schauder度理论,研究了算子方程Tx-T_0x Cx=f,f∈X的可解性。     

关于(S)_+型映射的一个区域不变定理及其应用

本文运用拓扑度方法,获得一个关于(S)_+型映射的区域不变定理。作为它的应用,本文得到了扩张映射的满值性,从而部分地回答了著名数学家L.Nirenberg提出的一个关于扩张映射满值性的公开问题。     

C逻辑值的类型及其应用

C逻辑值“真”和“假”分别为整数1和0,可作为普通的数参与数值运算,由此派生出许多巧妙算法。逻辑值与分支选择结构密切相关,在解决各类分支选择问题中有相应的应用。     

实验课课堂教学有效性的组织策略

本文从教学的有效性理论出发，通过分析，给出了在实验课课堂教学中实行滚动式、分层次教学的可行性分析，给出了具体的组织管理细节。讨论了以实验课为试点的优势及其可行性方案。     

检查搜索时舰艇编队匀速搜潜与跳跃式搜潜比较

在分析水面舰艇编队使用拖曳式线列阵声纳匀速搜潜和“跳跃式”搜潜过程的基础上,对仿真环境进行假设,并建立了水面舰艇搜潜蒙特卡洛法模型,通过仿真试验,对其在一定条件下检查搜潜时匀速搜索与跳跃式搜索效能进行研究,得出的相关结论对提高水面舰艇反潜作战运用水平具有较大的实际应用价值.     

消防行政诉讼若干问题探析

消防诉讼是消防生态的有机构成部分.消防事业社会化进程的加快,势必引发更多的涉消防诉讼案件.这些案件中既有因消防执法引起的消防行政诉讼,也有因灭火救援等引起的消防民事诉讼.对消防行政诉讼的类型、消防行政执法中易引发行政诉讼的问题、做好消防行政执法工作的措施等问题进行了探析.     

学科类型、刺激对注意分配的影响

本研究从刺激类型、学科类型来探讨个体注意分配的差异。本研究采用2×2×2混合设计,其中学科(理科、文科)、性别(男生、女生)为组间变量、刺激类型(声刺激、光刺激)为组内变量;因变量为反应时。实验结果表明:不同学科类型学生的注意分配差异性显著,理科学生的注意分配反应时低于文科学生的注意分配能力;不同的刺激类型的注意分配差异显著,光选择反应的反应时低于声选择反应时;不同性别学生的注意分配能力的差异不显著。结论:学科类型、刺激类型影响个体的注意分配能力。     

开流形的曲率与拓扑

应用比较几何的方法研究了完备非紧且具有特定曲率条件的黎曼流形,证明了在一定Pinching条件限制下,流形具有有限拓扑型或者微分同胚于Rn。     

Performance evaluation of a production/inventory system with periodic review and endogenous lead times

This paper considers a discrete time, single item production/inventory system with random period demands. Inventory levels are reviewed periodically and managed using a base‐stock policy. Replenishment orders are placed with the production system which is capacitated in the sense that there is a single server that sequentially processes the items one at a time with stochastic unit processing times. In this setting the variability in demand determines the arrival pattern of production orders at the queue, influencing supply lead times. In addition, the inventory behavior is impacted by the correlation between demand and lead times: a large demand size corresponds to a long lead time, depleting the inventory longer. The contribution of this paper is threefold. First, we present an exact procedure based on matrix‐analytic techniques for computing the replenishment lead time distribution given an arbitrary discrete demand distribution. Second, we numerically characterize the distribution of inventory levels, and various other performance measures such as fill rate, base‐stock levels and optimal safety stocks, taking the correlation between demand and lead times into account. Third, we develop an algorithm to fit the first two moments of the demand and service time distribution to a discrete phase‐type distribution with a minimal number of phases. This provides a practical tool to analyze the effect of demand variability, as measured by its coefficient of variation, on system performance. We also show that our model is more appropriate than some existing models of capacitated systems in discrete time. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

Some probability functions in reliability and their applications

There has been much research on the general failure model recently. In the general failure model, when the unit fails at its age t, Type I failure (minor failure) occurs with probability 1 ? p(t) and Type II failure (catastrophic failure) occurs with probability p(t). In the previous research, some specific shapes (constant, non‐decreasing, or bathtub‐shape) on the probability function p(t) are assumed. In this article, general results on some probability functions are obtained and applied to study the shapes of p(t). The results are also applied to determining the optimal inspection and allocation policies in maintenance problems. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007