面向应用的分布式多机联合计算的系统设计问题

随着计算机应用向分布和异构发展，如何建立一个具有良好性能价格比的分布式多机联合计算系统是当前计算机应用开发者遇到的重要课题。文中结合分布式仿真应用实例，对多计算机联合计算的系统划分、数据通讯机制和高性能并行计算问题进行了论述。     

Flexible capacity strategy in an asymmetric oligopoly market with competition and demand uncertainty

This article studies flexible capacity strategy (FCS) under oligopoly competition with uncertain demand. Each firm utilizes either the FCS or inflexible capacity strategy (IFCS). Flexible firms can postpone their productions until observing the actual demand, whereas inflexible firms cannot. We formulate a new asymmetrical oligopoly model for the problem, and obtain capacity and production decisions of the firms at Nash equilibrium. It is interesting to verify that cross‐group competition determines the capacity allocation between the two groups of firms, while intergroup competition determines the market share within each group. Moreover, we show that the two strategies coexist among firms only when cost differentiation is medium. Counterintuitively, flexible firms benefit from increasing production cost when the inflexible competition intensity is sufficiently high. This is because of retreat of inflexible firms, flexibility effect, and the corresponding high price. We identify conditions under which FCS is superior than IFCS. We also demonstrate that flexible firms benefit from increasing demand uncertainty. However, when demand variance is not very large, flexible firms may be disadvantaged. We further investigate the effects of cross‐group and intergroup competition on individual performance of the firms. We show that as flexible competition intensity increases, inflexible firms are mainly affected by the cross‐group competition first and then by the intergroup competition, whereas flexible firms are mainly affected by the intergroup competition. Finally, we examine endogenous flexibility and identify its three drivers: cost parameters, cross‐group competition, and intergroup competition. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 117–138, 2017     

修订地方性消防法规需要审视的几个关系

随着消防法的修订颁布,目前各地适用的地方性消防法规的相关规定已经不适应新形势下消防法制建设的需要,亟待重新修订。通过对消防法、相关法律以及部门消防规章与地方性消防法规之间关系的审视和分析,为地方性消防法规的修订提供参考。     

老子之“德”的当代价值审视

老子之“德”是法自然之“道”的具体体现,是以律己、谦恭和贵柔为主要内容的。随着我国物质生活水平的日益提高,人们过度追求物欲的满足,各种矛盾层出不穷,内心冲突不断加剧,人们的精神家园匮乏。所以,重新审视老子“德”的当代价值,对于构建和谐社会,促进人与自然、人与人、人与社会的和谐相处,化解人们的精神危机,具有重要的现实意义。     

对匡正干部部门选人用人风气的思考

新形势下匡正干部部门选人用人风气,是干部部门自身建设的重要内容,必须以加强理论学习为基础,不断提高干部工作者树立良好作风的自觉性;以加强党性修养和锻炼为根本,努力提升干部工作者的思想政治素质;以加强制度建设为保证,用工作纪律、行为规范约束干部工作者的用权行为.     

在解放思想解决问题中推进部队科学发展

在解放思想、解决问题中推进部队科学发展,就是要着力解决在新的思想高度上形成共识问题;解决部队建设全面加强、协调推进的问题;解决领导方式和工作方法问题.     

做好复杂电磁环境下实兵对抗训练中政治工作

针对复杂电磁环境下实兵对抗训练的特点,开展训练中政治工作,要夯实官兵思想根基,建强组织领导;周密制定预案,提高快反能力;灵活运用多种手段,保持不竭练兵动力.     

多操纵面战斗机动态控制分配策略研究(英文)

现代先进飞机配置多个操纵面且又冗余,这有利于实现非常规飞行,提高飞机敏捷性,使飞机在机动和故障时有更多的选择,但是同时也导致了飞机控制设计复杂度的增加.为了达到更好的效果,就必须利用控制分配器来充分利用多操纵面的不同带宽.从频率域角度出发,研究了动态控制分配方法,并将其应用于某型先进战斗机的控制分配器设计中,利用鸭翼的频率特性抵消府舱过载,经仿真验证,采用动态控制分配策略时,可以有效地减小座舱过载,同时还可以减小配平阻力,取得了良好的控制效果.     

Balancing a one‐way corridor capacity and safety‐oriented reliability: A stochastic optimization approach for metro train timetabling

In urban rail transit systems of large cities, the headway and following distance of successive trains have been compressed as much as possible to enhance the corridor capacity to satisfy extremely high passenger demand during peak hours. To prevent train collisions and ensure the safety of trains, a safe following distance of trains must be maintained. However, this requirement is subject to a series of complex factors, such as the uncertain train braking performance, train communication delay, and driver reaction time. In this paper, we propose a unified mathematical framework to analyze the safety‐oriented reliability of metro train timetables with different corridor capacities, that is, the train traffic density, and determine the most reliable train timetable for metro lines in an uncertain environment. By employing a space‐time network representation in the formulations, the reliability‐based train timetabling problem is formulated as a nonlinear stochastic programming model, in which we use 0‐1 variables to denote the time‐dependent velocity and position of all involved trains. Several reformulation techniques are developed to obtain an equivalent mixed integer programming model with quadratic constraints (MIQCP) that can be solved to optimality by some commercial solvers. To improve the computational efficiency of the MIQCP model, we develop a dual decomposition solution framework that decomposes the primal problem into several sets of subproblems by dualizing the coupling constraints across different samples. An exact dynamic programming combined with search space reduction strategies is also developed to solve the exact optimal solutions of these subproblems. Two sets of numerical experiments, which involve a relatively small‐scale case and a real‐world instance based on the operation data of the Beijing subway Changping Line are implemented to verify the effectiveness of the proposed approaches.     

Algorithm to solve a chance‐constrained network capacity design problem with stochastic demands and finite support

We consider the problem of determining the capacity to assign to each arc in a given network, subject to uncertainty in the supply and/or demand of each node. This design problem underlies many real‐world applications, such as the design of power transmission and telecommunications networks. We first consider the case where a set of supply/demand scenarios are provided, and we must determine the minimum‐cost set of arc capacities such that a feasible flow exists for each scenario. We briefly review existing theoretical approaches to solving this problem and explore implementation strategies to reduce run times. With this as a foundation, our primary focus is on a chance‐constrained version of the problem in which α% of the scenarios must be feasible under the chosen capacity, where α is a user‐defined parameter and the specific scenarios to be satisfied are not predetermined. We describe an algorithm which utilizes a separation routine for identifying violated cut‐sets which can solve the problem to optimality, and we present computational results. We also present a novel greedy algorithm, our primary contribution, which can be used to solve for a high quality heuristic solution. We present computational analysis to evaluate the performance of our proposed approaches. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 236–246, 2016