基于结构应变响应的高速枪击载荷识别的理论分析与实验方法

基于多自由度系统的运动微分方程和结构的几何方程推导出识别单一动态载荷的数学模型。并将此理论应用于枪击载荷的识别,获得了令人满意的结果。同时,给出了一套完整的动载识别的实验方法。     

坦克射击视景建模与实时动态显示

根据坦克射击视景景物的特征,采用了一种较优越的方案将视景进行分类建模.对景物模型进行简化和各种实时技术处理后,能在微机图形工作站上实时动态显示逼真的坦克射击视景.     

A branch‐and‐bound‐based solution approach for dynamic rerouting of airborne platforms

This article is a sequel to a recent article that appeared in this journal, “An extensible modeling framework for dynamic reassignment and rerouting in cooperative airborne operations” [ 17 ], in which an integer programming formulation to the problem of rescheduling in‐flight assets due to changes in battlespace conditions was presented. The purpose of this article is to present an improved branch‐and‐bound procedure to solve the dynamic resource management problem in a timely fashion, as in‐flight assets must be quickly re‐tasked to respond to the changing environment. To facilitate the rapid generation of attractive updated mission plans, this procedure uses a technique for reducing the solution space, supports branching on multiple decision variables simultaneously, incorporates additional valid cuts to strengthen the minimal network constraints of the original mathematical model, and includes improved objective function bounds. An extensive numerical analysis indicates that the proposed approach significantly outperforms traditional branch‐and‐bound methodologies and is capable of providing improved feasible solutions in a limited time. Although inspired by the dynamic resource management problem in particular, this approach promises to be an effective tool for solving other general types of vehicle routing problems. © 2013 Wiley Periodicals, Inc. Naval Research Logistics, 2013     

Bounded flexibility in days‐on and days‐off scheduling

This article presents a flexible days‐on and days‐off scheduling problem and develops an exact branch and price (B&P) algorithm to find solutions. The main objective is to minimize the size of the total workforce required to cover time‐varying demand over a planning horizon that may extend up to 12 weeks. A new aspect of the problem is the general restriction that the number of consecutive days on and the number of consecutive days off must each fall within a predefined range. Moreover, the total assignment of working days in the planning horizon cannot exceed some maximum value. In the B&P framework, the master problem is stated as a set covering‐type problem whose columns are generated iteratively by solving one of three different subproblems. The first is an implicit model, the second is a resource constrained shortest path problem, and the third is a dynamic program. Computational experiments using both real‐word and randomly generated data show that workforce reductions up to 66% are possible with highly flexible days‐on and days‐off patterns. When evaluating the performance of the three subproblems, it was found that each yielded equivalent solutions but the dynamic program proved to be significantly more efficient. © 2013 Wiley Periodicals, Inc. Naval Research Logistics 60: 678–701, 2013     

Firm embedding behavior of annular grooved projectiles impacting ductile metal targets

Annular grooved projectiles (AGPs) have drawn ongoing concerns as an advanced penetrator for their excellent anti-rebound capability in impacting metal plates. They could become embedded solidly in the target surface during low-velocity impact. In this investigation, the firm embedding behavior of AGP was observed by impact experiments. Corresponding numerical simulations provided a better understanding of this process. Experimental and numerical results indicated that the firm embedding behavior of AGP was mainly due to the filling-material in the groove rather than the friction between the projectile and target, unlike traditional shape such as conical projectile. According to observation, firm embedding process can generally be subdivided into four stages: initial-cratering stage, groove-filling stage, filling-material failure stage and rebound vibration stage. Moreover, the damage mechanics of target material around crater was obtained through microscopic tests. A comparison of the cross-sectional figures between the experiment and simulation proved that the analysis and the proposed method were reasonable and feasible, which further demonstrated that the firm embedding behavior has application potential in new concept warheads.     

A mathematical formulation and efficient heuristics for the dynamic container relocation problem

The container relocation problem (CRP) is concerned with emptying a single yard‐bay which contains J containers each following a given pickup order so as to minimize the total number of relocations made during their retrieval process. The CRP can be modeled as a binary integer programming (IP) problem and is known to be NP‐hard. In this work, we focus on an extension of the CRP to the case where containers are both received and retrieved from a single yard‐bay, and call it the dynamic container relocation problem. The arrival (departure) sequences of containers to (from) the yard‐bay is assumed to be known a priori. A binary IP formulation is presented for the problem. Then, we propose three types of heuristic methods: index based heuristics, heuristics using the binary IP formulation, and a beam search heuristic. Computational experiments are performed on an extensive set of randomly generated test instances. Our results show that beam search heuristic is very efficient and performs better than the other heuristic methods.Copyright © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 101–118, 2014     

污泥龄对污泥絮体中磷酸盐形态及其动态变化的影响

以污泥龄(SRT)为10 d和30 d的2组A/O-SBR反应器活性污泥为研究对象,探讨了SRT对污泥絮体中磷酸盐形态及其动态变化的影响。结果表明,污泥絮体中的磷主要分布于胞外聚合物(EPS),EPS磷占污泥絮体磷总质量的69.45%~73.36%。正磷酸盐(PO3-4-P)、低分子量聚磷酸盐(LMW Poly-P)和高分子量聚磷酸盐(HMW Poly-P)是污泥絮体磷的主要形态。高SRT(30 d)污泥絮体EPS磷含量明显大于中SRT(10 d),表现为前者较后者有更高的PO3-4-P和HMW Poly-P含量,对应着高SRT(30 d)污泥絮体较中SRT(10 d)有更高的磷含量,前者约为后者的1.37倍。厌氧/好氧反应过程中,中SRT(10 d)污泥絮体EPS磷的厌氧降低量和好氧升高量分别为高SRT(30 d)的1.35倍和1.46倍,主要归因于前者的PO3-4-P和HMW Poly-P较后者有更大的厌氧降低量,而PO3-4-P,LMW Poly-P和HMW Poly-P较后者有更大的好氧升高量,对应着中SRT(10 d)污泥絮体较高SRT(30 d)有更强的厌氧释磷和好氧吸磷能力。     

Decomposing inventory routing problems with approximate value functions

We present a time decomposition for inventory routing problems. The methodology is based on valuing inventory with a concave piecewise linear function and then combining solutions to single‐period subproblems using dynamic programming techniques. Computational experiments show that the resulting value function accurately captures the inventory's value, and solving the multiperiod problem as a sequence of single‐period subproblems drastically decreases computational time without sacrificing solution quality. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

机组动态过程分析中处理转子运动的方法

分析军用便携式发电机组在单机供电及并联供电情况下的动态过程有利于提高其供电质量.采用有限元法计算电机动态过程需要在电机电磁场计算时实现转子的自由转动.从运动导电媒质中的电磁场方程出发,分析了固定坐标系求解方法及移动坐标系求解各方法的特点.针对军用便携式发电机组单机供电及并联供电情况下动态过程的特点分析,对各种处理转子运动的方法进行了比较,得出的结论对于研究军用便携式发电机组单机供电及并联供电情况时处理转子运动的方法选取具有理论指导意义.     

基于Agent技术的战术互联网动态频谱管理系统

动态频谱管理是提升战术互联网作战效能的主要手段之一.首先分析了战术互联网以及动态频率管理工作特点的基础上,设计了一种基于Agent技术的动态频谱管理系统,并详细介绍了动态频谱管理的实现方法.