气候条件对城市火灾的影响规律

选取样本城市各项火灾数据和气象参数数据,对样本数据进行筛选计算,通过对两者的一元相关性进行研究,得出火灾概率和典型气象参数之间的关系。     

Modeling and analysis of multiobjective lot splitting for N‐product M‐machine flowshop lines

Lot splitting is a new approach for improving productivity by dividing production lots into sublots. This approach enables accelerating production flow, reducing lead‐time and increasing the utilization of organization resources. Most of the lot splitting models in the literature have addressed a single objective problem, usually the makespan or flowtime objectives. Simultaneous minimization of these two objectives has rarely been addressed in the literature despite of its high relevancy to most industrial environments. This work aims at solving a multiobjective lot splitting problem for multiple products in a flowshop environment. Tight mixed‐integer linear programming (MILP) formulations for minimizing the makespan and flowtime are presented. Then, the MinMax solution, which takes both objectives into consideration, is defined and suggested as an alternative objective. By solving the MILP model, it was found that minimizing one objective results in an average loss of about 15% in the other objective. The MinMax solution, on the other hand, results in an average loss of 4.6% from the furthest objective and 2.5% from the closest objective. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

浅析油品密度在线检测的几种方法

油品密度是油品交接计量中的重要参数之一,因此需要对它进行准确的测定。随着科学技术的发展,检测油品密度的方法也在不断的进步。介绍了浮子法、静压法、射线法、振动法以及超声波法等几种比较有效的油品密度在线检测方法,并详细分析了每一种方法的优缺点以及适用的场合,最后提出了几个在线检测应该注意的问题,供使用者根据实际情况选择合适的检测方法。     

核裂变过程动态模拟计算的动力学系数

本文利用(c,h,a)三参数旋转体模型计算了形变核的相对表面能、相对库仑能及相对转动能。这些相对能量与具体核无关,具有普适性,可以用于核裂变动态过程的模拟计算。利用这些结果,计算了一些核的形变位能随三参数变化的情况,给出了裂变位垒高度,与实验结果符合较好。对~(236)U的形变位能曲面作了较详细的分析,得出一些有益的结论。用Werner—Wheeler方法计算了形变核的惯性质量和粘滞张量随三参数变化情况,对断点线方程作了深入讨论,为核裂变动态过程的计算机模拟准备了必要的系数。     

一种离散描述器系统状态调节的反馈控制律

本文探讨了形如 Ex_(k+1)=Ax_k+Bu_k 的定常离散描述器系统的状态调节问题,得出了一个用至多 n 步使描述器从状态 x_0到达原点的闭环反馈控制律μ_k=Kx_k。     

瞄准具多因素误差分析模型

本文利用坐标轴旋转公式建立了瞄准具多因素误差分析模型。为机械式、半独立式瞄准具的不解体检测提供了理论基础.     

数字位置差动瞄准线独立控制系统原理分析与试验研究

基于数字伺服技术介绍了自行高炮数字位置差动瞄准线独立控制系统结构原理,给出了传递函数分析及试验研究结果。指出该系统具有动态精度高、通用性强等特点。     

三点弯曲梁的动态断裂分析

利用梁的初等弯曲理论和线弹簧模型建立了三点弯曲裂纹梁的动态断裂分析方法,该方法使计算大为简化。数值结果表明该方法具有足够的精度     

Rendezvous search when marks are left at the starting points

Leaving marks at the starting points in a rendezvous search problem may provide the players with important information. Many of the standard rendezvous search problems are investigated under this new framework which we call markstart rendezvous search. Somewhat surprisingly, the relative difficulties of analysing problems in the two scenarios differ from problem to problem. Symmetric rendezvous on the line seems to be more tractable in the new setting whereas asymmetric rendezvous on the line when the initial distance is chosen by means of a convex distribution appears easier to analyse in the original setting. Results are also obtained for markstart rendezvous on complete graphs and on the line when the players' initial distance is given by an unknown probability distribution. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 722–731, 2001     

On‐line algorithms for minimizing makespan on batch processing machines

We consider problem of scheduling jobs on‐line on batch processing machines with dynamic job arrivals to minimize makespan. A batch machine can handle up to B jobs simultaneously. The jobs that are processed together from a batch, and all jobs in a batch start and complete at the same time. The processing time of a batch is given by the longest processing time of any job in the batch. Each job becomes available at its arrival time, which is unknown in advance, and its processing time becomes known upon its arrival. In the first part of this paper, we address the single batch processing machine scheduling problem. First we deal with two variants: the unbounded model where B is sufficiently large and the bounded model where jobs have two distinct arrival times. For both variants, we provide on‐line algorithms with worst‐case ratio (the inverse of the Golden ratio) and prove that these results are the best possible. Furthermore, we generalize our algorithms to the general case and show a worst‐case ratio of 2. We then consider the unbounded case for parallel batch processing machine scheduling. Lower bound are given, and two on‐line algorithms are presented. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 241–258, 2001