Solution of minisum and minimax location–allocation problems with Euclidean distances

A new method for the solution of minimax and minisum location–allocation problems with Euclidean distances is suggested. The method is based on providing differentiable approximations to the objective functions. Thus, if we would like to locate m service facilities with respect to n given demand points, we have to minimize a nonlinear unconstrained function in the 2m variables x₁,y₁, ?,x_m,y_m. This has been done very efficiently using a quasi-Newton method. Since both the original problems and their approximations are neither convex nor concave, the solutions attained may be only local minima. Quite surprisingly, for small problems of locating two or three service points, the global minimum was reached even when the initial position was far from the final result. In both the minisum and minimax cases, large problems of locating 10 service facilities among 100 demand points have been solved. The minima reached in these problems are only local, which is seen by having different solutions for different initial guesses. For practical purposes, one can take different initial positions and choose the final result with best values of the objective function. The likelihood of the best results obtained for these large problems to be close to the global minimum is discussed. We also discuss the possibility of extending the method to cases in which the costs are not necessarily proportional to the Euclidean distances but may be more general functions of the demand and service points coordinates. The method also can be extended easily to similar three-dimensional problems.     

建立完善红外光电产品技术标准 促进引导军民品装备及市场的发展

一．引言 随着红外热成像技术的发展及国外武器装备夜视装备的更新换代,我国海、陆、空、防化的武器装备均提出了装备二代热像仪的需求。红外热成像技术已经从一代发展到二代、三代,一代红外热成像装置采用红外探测器线阵扫描成像,二代和三代红外热成像装置则采用红外焦平面阵列,但总体上来说,二代和三代红外热成像装置仍处于发展阶段,相对于一代技术,二代热像仪的性能指标体系、     

用于闭式循环柴油机不依赖空气推进装置的吸收器尺寸估算模型研究

根据闭式循环柴油机推进装置（ＣＣＤＡＩＰ）的废气处理要求,研究提出了旋转式二氧化碳吸收器的填料内径、外径、轴向高度的估算数学模型,并对用水吸收二氧化碳的吸收器填料设计尺寸进行了操作安全性校核．     

提高潜艇核安全性的措施

本文根据对潜艇处于水下状态发生辐射事故时的辐射影响的分析,得出当燃料元件包壳破损率和蒸汽发生器传热管泄漏量即使在允许限值内,主辅机舱空气放射性浓度有可能超过允许水平,而直接影响艇员的健康,并针对这一点提出了相应的改进措施。     

The investigation of NTO/HMX-based plastic-bonded explosives and its safety performance

3-nitro-1,2,4-triazol-5-one (NTO) is the main component of insensitive munitions (IM) formulation because of its outstanding insensitive properties.In this paper,a series of NTO/HMX-based composite explosives were prepared and characterized.The study focuses on the effect of NTO on the performance of the formulations,especially the safety performance.The results revealed that the mechanical sensi-tivity of formulations was associated with NTO content,as well as the thermal conductivity,specific heat capacity and Arrhenius parameters.Then,the high amount of NTO using in formulation was proved to be helpful for NTO/HMX-based formulation to exhibit good thermal safety.Besides,by accelerating rate calorimeter (ARC) and a modified cook-offequipment,the pressure and pressure rise rate were proved as the important indicator for judging the thermal safety performance in confined spaces.Finally,the numerical simulation was used as a credible method for predicting the respond temperature of cook-off experiment.     

排气波纹管的设计研究

给出了波纹管轴向补偿与径向补偿能力的关系,并提供了选型依据、设计计算方法和实例,可供设计者参考。     

军队人才引进工作要尊重经济规律

人才引进工作是我军人才建设的重要环节。当前在人才引进中还有不少困难。应当正视在公民职业选择行为中经济因素的影响。要随着社会生产力和人民生活水平提高适时增加军人工资待遇,推进军官职业化进程,并完善国防生选拔培养制度。     

利用OpenGL开发虚拟潜望镜视景系统

介绍了在ＰＣ环境下,利用ＯｐｅｎＧＬ图形库开发虚拟潜望镜视景系统的背景、意义及系统的功能,并介绍了其中若干关键技术的实现方法．     

频率捷变雷达干扰方法分析

频率捷变雷达有许多其它雷达无法比拟的优点,在现代雷达体制中占有重要地位。分析了频率捷变雷达的特点,根据其工作原理,提出了干扰频率捷变雷达的几种方法,分析了各自的优点和局限性。阐述了干扰方法的原理及实现的技术途径,并给出了有关参数的计算方法和实例。     

鱼雷气幕屏蔽和降噪的实验研究

利用气流提高鱼雷螺旋桨叶片处的压力,减少螺旋桨的空泡,从而降低鱼雷辐射噪声,以及利用人工气幕屏蔽螺旋桨噪声,可以大大减小在鱼雷基阵处的自噪声。实验研究表明,在鱼雷自导工作的频率范围,可降低自噪声约１０ｄＢ以上。