最大面积避障矩形问题的解法

建立了在一个含有若干障碍点的矩形母域内求一个最大面积避障矩形问题的数学模型.通过分析避障矩形的几何特性,找到了求解这一含有0-1变量的非线性规划数学模型的一种特殊解法.     

中国机器人产业持续发展的制约因素及措施

中国机器人企业由于研发力量薄弱,缺乏核心技术,高端人才匮乏,产品成本高昂,加之没有政策引领,没能形成规模化应用,所占市场份额不足10%。文章探讨如何破解中国机器人产业现存问题并寻求针对性解决措施。     

Exact algorithms and bounds for the dynamic assignment interdiction problem

We study a multi‐stage dynamic assignment interdiction (DAI) game in which two agents, a user and an attacker, compete in the underlying bipartite assignment graph. The user wishes to assign a set of tasks at the minimum cost, and the attacker seeks to interdict a subset of arcs to maximize the user's objective. The user assigns exactly one task per stage, and the assignment costs and interdiction impacts vary across stages. Before any stage commences in the game, the attacker can interdict arcs subject to a cardinality constraint. An interdicted arc can still be used by the user, but at an increased assignment cost. The goal is to find an optimal sequence of assignments, coupled with the attacker's optimal interdiction strategy. We prove that this problem is strongly NP‐hard, even when the attacker can interdict only one arc. We propose an exact exponential‐state dynamic‐programming algorithm for this problem as well as lower and upper bounds on the optimal objective function value. Our bounds are based on classical interdiction and robust optimization models, and on variations of the DAI game. We examine the efficiency of our algorithms and the quality of our bounds on a set of randomly generated instances. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 373–387, 2017     

三维半线性波动方程初值问题解的破裂

研究了半线性波动方程初值问题在三维空间中解的生命跨度的上界估计,关于此初值问题的爆破解将被建立。无论多么小的初值,该问题都没有整体解,在前人研究的基础上给出该初值问题解的生命跨度的上界估计。     

公众聚集场所消防监督管理存在问题及对策

近年来 ,我国公众聚集场所群死群伤恶性火灾时有发生 ,原因固然是多方面的 ,但是 ,公众聚集场所在监督和管理两个层面上存在的突出问题和薄弱环节 ,不能不引起我们的高度重视。结合多年来开展消防监督工作的实践 ,从消防法律法规、消防安全管理体制、技术标准等方面分析了公众聚集场所消防安全监督管理存在的问题 ,并提出了相应对策措施。     

大学生问题行为及对策浅析

本文从心理学的角度分析了大学生常见的问题行为,对问题行为的性质、外部表现、心理特征及应对措施作了详尽分析,集中讨论了人格不适、失恋、考试焦虑及人格障碍等方面的问题,以期有助于大学生问题行为的处理。     

混合遗传算法在大型运输机装载问题中的运用

为解决大型运输机装载方案的制定问题,构建了考虑飞机重心、飞机载重量、货舱容积、货物摆放方向、承压能力、装载优先级、货物底置位置和系留等现实约束的装载方案数学模型,提出了一种新的融合整体退火选择方式和对交叉、变异概率进行自适应处理的混合遗传算法,并将此方法运用到两个货物装载算例中。仿真实例表明:该混合遗传算法方法为大型运输机装载方案制定选择提供了一种科学有效的决策方法。     

Scheduling and lot streaming in two‐machine open shops with no‐wait in process

We study the problem of minimizing the makespan in no‐wait two‐machine open shops producing multiple products using lot streaming. In no‐wait open shop scheduling, sublot sizes are necessarily consistent; i.e., they remain the same over all machines. This intractable problem requires finding sublot sizes, a product sequence for each machine, and a machine sequence for each product. We develop a dynamic programming algorithm to generate all the dominant schedule profiles for each product that are required to formulate the open shop problem as a generalized traveling salesman problem. This problem is equivalent to a classical traveling salesman problem with a pseudopolynomial number of cities. We develop and test a computationally efficient heuristic for the open shop problem. Our results indicate that solutions can quickly be found for two machine open shops with up to 50 products. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005     

Modeling and analyzing multiple station baggage screening security system performance

In the aftermath of the tragic events of 11 September 2001, numerous changes have been made to aviation security policy and operations throughout the nation's airports. The allocation and utilization of checked baggage screening devices is a critical component in aviation security systems. This paper formulates problems that model multiple sets of flights originating from multiple stations (e.g., airports, terminals), where the objective is to optimize a baggage screening performance measure subject to a finite amount of resources. These measures include uncovered flight segments (UFS) and uncovered passenger segments (UPS). Three types of multiple station security problems are identified and their computational complexity is established. The problems are illustrated on two examples that use data extracted from the Official Airline Guide. The examples indicate that the problems can provide widely varying solutions based on the type of performance measure used and the restrictions imposed by the security device allocations. Moreover, the examples suggest that the allocations based on the UFS measure also provide reasonable solutions with respect to the UPS measure; however, the reverse may not be the case. This suggests that the UFS measure may provide more robust screening device allocations. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2005.     

Scheduling recurrent construction

A problem we call recurrent construction involves manufacturing large, complex, expensive products such as airplanes, houses, and ships. Customers order configurations of these products well in advance of due dates for delivery. Early delivery may not be permitted. How should the manufacturer determine when to purchase and release materials before fabrication, assembly, and delivery? Major material expenses, significant penalties for deliveries beyond due dates, and long product makespans in recurrent construction motivate choosing a release timetable that maximizes the net present value of cash flows. Our heuristic first projects an initial schedule that dispatches worker teams to tasks for the backlogged products, and then solves a series of maximal closure problems to find material release times that maximize NPV. This method compares favorably with other well‐known work release heuristics in solution quality for large problems over a wide range of operating conditions, including order strength, cost structure, utilization level, batch policy, and uncertainty level. Computation times exhibit near linear growth in problem size. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004