Complexity of sequencing tasks in assembly cells attended by one or two robots

This article develops a structure by which the computational complexity of sequencing problems in assembly cells attended by one or two robots may be evaluated. A taxonomy of cell features that affect complexity is developed, polynomial-time algorithms are presented for certain problems, and borderline designs at which complexity changes dramatically are identified. Results will aid cell designers by indicating classes of designs for which task sequence may be optimized and other classes for which this cannot be done. Designs which entail features that lead to intractable sequencing problems may be modified to maximize cell productivity.     

The search for an intelligent evader: Strategies for searcher and evader in the two-region problem

This paper considers the search for an evader concealed in one of two regions, each of which is characterized by its detection probability. The single-sided problem, in which the searcher is told the probability of the evader being located in a particular region, has been examined previously. We shall be concerned with the double-sided problem in which the evader chooses this probability secretly, although he may not subsequently move: his optimal strategy consists of that probability distribution which maximizes the expected time to detection, while the searcher's optimal strategy is the sequence of searches which limits the evader to this expected time. It transpires for this problem that optimal strategies for both searcher and evader may generally be obtained to a surprisingly good degree of approximation by using the optimal strategies for the closely related (but far more easily solved) problem in which the evader is completely free to move between searches.     

基于CDMA和JMS的后勤应用系统数据通信方案研究

数据通信是后勤领域应用系统中亟待解决的重要问题.大部分接入军事综合信息网的单位,可利用该广域网,采用JMS消息服务技术,实现分布式系统数据通信.尚未接入军事综合信息网的单位,可以依托专用CDMA无线通信网络,该网络覆盖面广,通信可靠,建立迅速,维护费用低,能够实现安全、及时地传输业务数据.两者结合,将构成一个全方位、一...     

具有规范化的四元数递推计算的公式误差估计

对捷联式制导系统中目前常用的四元数递推公式进行误差估计,给出利用观测数据计算四元数的误差界的公式,还介绍了保持四元数范数不变的一类递推公式。     

周作人自编文集的命名风格

周作人自编文集的命名风格主要有三点：一是简单,简单就是简要、真实和腴润;二是苦涩,苦涩是一种人生态度和审美追求;三是自然,自然是一种文学价值标准,含有平淡、天成的意蕴。     

加强网络国防建设战略运筹需要强化的六种意识

针对网络国防的现实需求,文章就加强网络国防建设的战略运筹指出了需要强化的六种意识：忧患意识,全局意识,创新意识,主动意识,重点意识,优势意识。在分析了三个方面的忧患意识,归纳了服务于国家安全战略、加强全局筹划、强化长远效益的全局意识。总结了理论创新、法律创新、技术创新为主要领域的创新意识等基础上,提出了维护国家根本利益、聚力局部竞争优势、拓展综合防卫能力的重点意识,探讨了主动探索建设途径、主动加强机制建设、主动构建核心能力的主动意识．分析了尽快形成战斗力生成模式优势、尽快形成防御力量和人才优势、尽快形成军民融合发展体系的优势意识。     

Uniformly minimum variance unbiased estimates of operational readiness and reliability in a two-state system

This paper obtains the uniformly minimum variance unbiased estimates of two indices of performance of a system which alternates between two states “up” or “down” in accordance with a Markov process. The two indices are (1) operational readiness, which measures the probability that the system will be up when needed; and (2) operational reliability, which measures the probability that the system will be up during the entire time of need. For the purpose of obtaining these estimates, two types of observations are considered: (a) those which reveal only the state of system at isolated time-points, and (b) those which continuously record the duration of the “up” and “down” times of the system.     

A new approach for dealing with the startup problem in discrete event simulation

This article proposes a practical, data-based statistical procedure which can be used to reduce or remove bias owing to artificial startup conditions in simulations aimed at estimating steady-state means. We discuss results of experiments designed to choose good parameter values for this procedure, and present results of extensive testing of the procedure on a variety of stochastic models for which partial analytical results are available. The article closes with two illustrations of the application of the procedure to more complex statistical problems which are more representative of the kinds of purposes for which real-world steady-state simulation studies might be undertaken.     

Dependence in target element detections induced by the environment

When modeling the detection of targets in a simulation of combat, the detection process is frequently represented as a series of independent detections of individual elements of the target. This assumption ignores the effect of a common but unknown field environment within which the detections take place. In this article, multivariate survival distributions are developed for target element detections which occur in an unknown dynamic environment. A proportional hazards representation is adopted, which uses a random variable multiplying the detection rate to account for the effect of the environment. Several special cases are examined which are useful for modeling target unit detections.     

The matrix game derived from the many-against-many battle

The many-against-many battle, which is a variant of the Friedman's one-against-many battle, is formulated as a two-person constant-sum game. It is shown that the matrix which expresses this game has a saddle point. Some cases are presented in which the payoff matrix of the game can be reduced. Finally, some parametrically special cases are analyzed.     

一纲多本:存在的问题对策与建议

"一纲多本"教科书政策是当代社会多元文化的价值诉求,同时也是我国基础教育改革的应然选择。然而,"一纲多本"政策在实施过程中却引发了学生学习负担加重;学生学习结果呈现"两极化"趋势;教科书质量不理想;教师专业能力发展出现困惑等四方面的现实问题。文章在分析"一纲多本"引发问题原因的基础上,从课程标准、教科书质量、学生和教师等几个方面对其未来的发展前景进行了展望。     

信息技术与中国远距离教育合作体系的建设

现代信息技术所引起的远程教育的变化是革命性的,由此产生了全新的现代网络大学.中国的普通高校、成人高校和广播电视大学都将参与进去,这是它们发展的新机会,也是新的挑战.我国教育的发展方式正由外延的数量扩张型转入内涵的规模质量型,整个教育系统以及远程教育的发展需要组织创新,而最重要的是加强教育合作.从教育改革、特别是课程改革的要求看,广播电大与普通高校的合作应以课程的开放管理为基础,建立具有融洽性、通用性、灵活性、整体性和可操作性的合作关系,目标是给求学者以充分选择的自由性和再选择的变通性.只有在这种开放课程的合作模式中,广播电大才有可能成为中国远程教育的主角之一.     

军用数据库安全审计系统的设计

在指控系统应用过程中,需要审查与系统安全相关的所有操作,并对不安全的操作行为进行报警。根据指控系统中数据库审计四要素的要求,提出将应用系统级审计与数据库级审计相结合的方法,最终实现两种级别审计的统一。解决了以往指控系统审计方式单一的问题,满足了军用数据库安全防护的要求。     

孙子“奇正”思想在武警部队反恐怖行动中的运用

我国现存最早的兵书《孙子兵法》,蕴含着许多克敌制胜的谋略,其中“奇正”思想在孙武战术思想体系中占有重要的位置。研究孙子“奇正”思想,并借鉴运用于武警部队反恐怖行动,对有效处置恐怖事件有着重要的现实意义。     

直升机攻潜过程中投雷点的选择

提出一种优化直升机投雷点的方法,其中考虑了小型反潜鱼雷航程短的特点,以及鱼雷与目标相对方位的变化对鱼雷自导作用距离的影响。最终给出一组优化的数学程序。它可为直升机攻潜过程中投雷点的选择提供一条科学决策的途径。     

被动导引头对噪声调频源镜像目标抑制技术

研究了相位干涉仪体制被动导引头对噪声调频干扰源地面镜像目标抑制技术,分析了地面镜像目标对相位干涉仪测角的影响,给出了一种相位干涉仪体制被动导引头抑制噪声调频干扰源地面镜像目标影响的方法。     

“前进一步自然宽”——也谈军事战略思维“转型”

军事战略思维转型是推进中国特色军事变革的内在要求和重要组成部分,也是信息化条件下加强军队建设的一项重要内容。中国特色军事变革,不仅需要器物层面变革的支撑,更需要以军事战略思维转型为核心的精神层面变革的引领。     

Developing production schedules which balance part usage and smooth production loads for just-in-time production systems

A mixed-model multilevel manufacturing facility running under a just-in-time (JIT) production system is controlled by setting the production schedule for the highest level in the facility, which is usually a mixed-model final assembly line. The schedule is set to achieve the goals of the organization, which under JIT are (1) to keep a constant rate of part usage, and (2) to maintain a smooth production load. In this article we extend earlier work in the literature, which focused on the first goal, by developing scheduling procedures which satisfy both goals. Properties of the resulting production schedules are analyzed and illustrative examples are presented.     

A continuous submarine versus submarine game

This paper analyzes, from a game-theoretic standpoint, the simultaneous choice of speeds by a transitor and by an SSK which patrols back and forth perpendicular to the transitor's course. Using idealized acoustic assumptions and a cookie-cutter detection model which ignores counterdetection, we are able to present the problem as a continuous game, and to determine an analytic solution. The results indicate that with these assumptions, there are conditions under which neither a “go fast” nor a “go slow” strategy is optimal. The game provides a good example of a continuous game with a nontrivial solution which can be solved effectively.     

Queueing systems with service interruptions II

We present an exact solution method for a single-server queueing system which alternates between periods in which service can be provided (on-periods) and periods in which the server is out of operation (off-periods). The arrival process is Poisson, on-periods are assumed to have a phase-type distribution, and service times and off-periods are assumed to be arbitrary.