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     

雷达天线扫描方式的自动识别方法

为了对雷达天线扫描方式进行自动识别,改进开发了天线扫描方式模拟器,并分别研究了电子扫描和机械扫描的特征提取和识别方法。基于最大主瓣脉冲序列的特征参数实现电子扫描和机械扫描的区分,然后基于单个天线扫描周期脉冲序列的特征参数实现8种机械扫描方式的自动识别。仿真结果表明,本文方法能够区分一维电扫、二维电扫和机械扫描,并且采用支持向量机决策树对机械扫描方式的识别正确率高于决策树方法。     

风冷式质子交换膜燃料电池湿度调节特性分析

质子交换膜燃料电池（Proton Exchange Membrane Fuel Cells,PEMFC）的内部环境是影响电堆性能及寿命的重要因素,针对风冷式燃料电池运行特点,在分析燃料电池温、湿度环境控制方式的基础上,研究了反应风速对系统湿度特性的影响,提出了反应风速与温度对湿度进行联合控制的方式,并通过3kW小型燃料电池样机实验,验证了该方法的可行性。     

纵向涡发生器对棒状燃料元件温度场的影响分析

运用CFD方法,模拟计算了在反应堆棒状燃料元件包壳表面加装纵向涡产生器(LVG)后,燃料棒、气隙、包壳和冷却剂的温度场和冷却剂的流场。计算时采用分块结构网格对带LVG的计算区域划分网格,使用SSTk-ω模型模拟冷却剂的湍流流动,对于控制方程和湍流方程的离散采用二阶格式以保证计算精度。计算结果表明:加装LVG后,包壳和冷却剂间的换热有所改善,燃料棒、气隙和包壳的最高温度有所降低。在LVG附近,燃料棒、气隙、包壳和冷却剂温度均会出现一个峰值,然后急剧下降。冷却剂流动的湍动能突然增强,有效地增强了冷却剂的横向流动,经过LVG后,湍动能逐渐减弱,横向流动速度也逐渐减小。     

新航母时代复兴

航空母舰是海上航母战斗群作战体系的核心。在现代网络中心战中,它又将成为海战的一个关键节点。首先介绍了世界航母的总体状况,然后介绍了几个主要航母拥有国的航母发展具体情况,重点详述各国正在建造中的新型航母,包括加大的舰体尺寸、新颖的外观、增强的功能、最新式的电子设备和武备,展现了航母出现复兴的现状。     

改进ADC方法及其在武器装备系统效能评估中的应用

在分析武器装备系统效能特点的基础上,针对装备定型试验的应用需求,提出一种改进可用性-可信性-能力法,以解决传统方法在系统状态划分上无法准确全面描述武器装备实际可用性的问题。提出增加中间状态的策略,对效能综合计算模式、状态描述与计算方法、状态转移计算方法和能力计算方法做整体改进,在此基础上开发了支撑软件SEEK。并以某型主战坦克系统效能评估为例,验证了该方法的可行性和有效性。