液化石油气火灾的预防及扑救

在分析液化石油气的组成成份及其理化性质的基础上,针对液化石油气的火灾危险性及火灾特点,提出了防火防爆及火灾扑救措施.     

论化工企业的防火设计

通过分析现行化工企业防火设计的基本做法和趋势,提出化工企业防火设计的要点及应注意的问题.     

美军武装直升机电子战设备的现状与发展趋势

介绍了武装直升机在现代战场上面临的种种威胁,重点介绍了美军武装直升机目前装备的电子战设备和尚处于研制中的新一代综合性电子战设备,分析了美军武装直升机电子战设备的发展趋势。     

英语写作中的词汇教学

英语写作教学是英语教学中极其重要的环节 ,针对写作中所碰到的词汇教学上的困难 ,本文提出了“词组滚雪球”和“五句日记法”的教学方法 ,以助广大学生更好的提高英语写作能力     

对光的半波损失的探讨

本文根据光的电磁波理论 ,对光的半波损失产生的条件及本质进行了深入的探讨 ,并对几个光学实验进行了分析。证明了光只有在特定的角度入射时才会发生半波损失 ,在一般斜入射时 ,反射光并没有半波损失 ,但有相位的突变     

知识经济与计算机教育改革

随着人类社会的进步和科学技术的迅猛发展,人类正面临着由物质经济向知识经济转变的历史时期,高新技术正深刻地影响着经济发展、社会进步和人类一切活动。本文就知识经济和信息产业对计算机科学与技术教育的挑战和我们如何把握机遇,深化教学改革,培养适应二十一世纪需要的高质量的信息技术人才,谈谈自己的认识和看法。     

教考结合 教学相长——公关文秘专业考核方式改革初探

本文论述了公关文秘专业深化改革考核方法的指导思想、具体做法、配套措施和实施效果。结合具体课程重点阐述了案例讨论、情景模拟、实地调查、卷面考试等多种方式结合的考核方法     

试论屈原的人生观

屈原的人生观是以立志成名、追求理想、进德修业、乐观向上为主要特征的 ,表现出了胸襟宽阔、锐意进取、昂扬奋发的气概。它能够使人从中获得极大的精神鼓舞和深刻的人生启迪     

Opportunistic retooling of a flexible machine subject to failure

A set of jobs can be processed without interruption by a flexible machine only if the set of tools required by all jobs can be loaded in the tool magazine. However, in practice the total number of tools required by a job set would exceed the tool magazine capacity. In such situations, the job set has to be carefully partitioned at the start of the production run such that each partition can be processed without interruption. During the production run, if there are unscheduled machine downtimes due to machine failure, this provides an additional opportunity to optimally retool the magazine for a smaller job set consisting of just the unprocessed jobs. In this paper, we study job sequencing rules that allow us to minimize the total expected cost of machine down time due to machine failures and magazine retooling, assuming a dynamic re‐sequencing of the unprocessed jobs after each machine failure. Using these rules, we develop a branch‐and‐bound heuristic that allows us to solve problems of reasonable size. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 79–97, 2001     

Iterative coloring extension of a maximum clique

In this paper we present an improved branch and bound algorithm for the vertex coloring problem. The idea is to try to extend the coloring of a maximum clique to its adjacent vertices. If this succeeds, its successive neighbors are considered; in case of failure (i.e., in the case the initial colors are not sufficient), working on the subgraph induced by the maximum clique and its neighborhood, the lower bound is improved by seeking for an optimal coloring of this subgraph by branch and bound. The process is repeated iteratively until the whole graph is examined. The iterative scheme exploits a further lower bound obtained by integrating a simple algorithm into the maximum clique search, and a new method to compute upper bounds on subgraphs. Furthermore, a new branching rule and a method for the selection of the initial maximum clique are presented. Extensive computational results and comparisons with existing exact coloring algorithms on random graphs and benchmarks are given. © 2001 John Wiley & Sons, Inc. Naval Research Logistic 48: 518–550, 2001