Barrier Lyapunov functions-based dynamic surface control with tracking error constraints for ammunition manipulator electro-hydraulic system

This paper focuses on the dynamic tracking control of ammunition manipulator system. A standard state space model for the ammunition manipulator electro-hydraulic system (AMEHS) with inherent non-linearities and uncertainties considered was established. To simultaneously suppress the violation of tracking error constraints and the complexity of differential explosion, a barrier Lyapunov functions-based dynamic surface control (BLF-DSC) method was proposed for the position tracking control of the ammunition manipulator. Theoretical analysis prove the stability of the closed-loop overall system and the tracking error converges to a prescribed neighborhood asymptotically. The effectiveness and dynamic tracking performance of the proposed control strategy is validated via simulation and experi-mental results.     

充分利用农业资源优势 推进新疆农业可持续发展

新疆地大物博,有着发展农业的资源优势,只有抓住“西部大开发”这个机遇,以市场为导向,加大产业 结构调整力度,积极推进农业产业化进程,以保护生态环境为前提,发展生态农业,才能促进新疆农业可持续发展。     

Non‐zero‐sum nonlinear network path interdiction with an application to inspection in terror networks

A simultaneous non‐zero‐sum game is modeled to extend the classical network interdiction problem. In this model, an interdictor (e.g., an enforcement agent) decides how much of an inspection resource to spend along each arc in the network to capture a smuggler. The smuggler (randomly) selects a commodity to smuggle—a source and destination pair of nodes, and also a corresponding path for traveling between the given pair of nodes. This model is motivated by a terrorist organization that can mobilize its human, financial, or weapon resources to carry out an attack at one of several potential target destinations. The probability of evading each of the network arcs nonlinearly decreases in the amount of resource that the interdictor spends on its inspection. We show that under reasonable assumptions with respect to the evasion probability functions, (approximate) Nash equilibria of this game can be determined in polynomial time; depending on whether the evasion functions are exponential or general logarithmically‐convex functions, exact Nash equilibria or approximate Nash equilibria, respectively, are computed. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 139–153, 2017     

Optimally scheduling interfering and non‐interfering cranes

This article treats the problem of scheduling multiple cranes processing jobs along a line, where cranes are divided into different groups and only cranes in the same group can interfere with each other. Such crane scheduling problems occur, for example, at indented berths or in container yards where double rail‐mounted gantry cranes stack containers such that cranes of the same size can interfere with each other but small cranes can pass underneath larger ones. We propose a novel algorithm based on Benders decomposition to solve this problem to optimality. In a computational study, it is shown that this algorithm solves small and medium‐sized instances and even many large instances within a few seconds or minutes. Moreover, it improves several best known solutions from the literature with regard to the simpler problem version with only one crane group. We also look into whether investment in more complicated crane configurations with multiple crane groups is actually worthwhile.     

论火灾与可持续发展观的内在联系

可持续发展是人类迫切解决的问题,火灾对可持续发展构成巨大威胁.针对火灾的危害,从防灾角度研究可持续发展观,揭示火灾与可持续发展的内在联系,为人类有效控制火灾提供正确的认识论和科学的方法论.     

A note on “resource flexibility with responsive pricing”

We revisit the capacity investment decision problem studied in the article “Resource Flexibility with Responsive Pricing” by Chod and Rudi [Operations Research 53, (2005) 532–548]. A monopolist firm producing two dependent (substitutable or complementary) products needs to determine the capacity of one flexible resource under demand risk so as to maximize its expected profit. Product demands are linear functions of the prices of both products, and the market potentials are random and correlated. We perform a comparative statics analysis on how demand variability and correlation impact the optimal capacity and the resulting expected profit. In particular, C&R study this problem under the following assumptions/approximations: (i) demand intercepts follow a bivariate Normal distribution; (ii) demand uncertainty is of an additive form; (iii) and under approximate expressions for the optimal capacity and optimal expected profit. We revisit Propositions 2, 3, 4, 5, and 10 of C&R without these assumptions and approximations, and show that these results continue to hold (i) for the exact expressions for the optimal expected profit and optimal capacity, and (ii) under any arbitrary continuous distribution of demand intercepts. However, we also show that the additive demand uncertainty is a critical assumption for the C&R results to hold. In particular, we provide a case of multiplicative uncertainty under which the C&R results (Propositions 2 and 3) fail. © 2010 Wiley Periodicals, Inc. Naval Research Logistics 2010     

Scheduling parallel dedicated machines with the speeding‐up resource

We consider a problem of scheduling jobs on m parallel machines. The machines are dedicated, i.e., for each job the processing machine is known in advance. We mainly concentrate on the model in which at any time there is one unit of an additional resource. Any job may be assigned the resource and this reduces its processing time. A job that is given the resource uses it at each time of its processing. No two jobs are allowed to use the resource simultaneously. The objective is to minimize the makespan. We prove that the two‐machine problem is NP‐hard in the ordinary sense, describe a pseudopolynomial dynamic programming algorithm and convert it into an FPTAS. For the problem with an arbitrary number of machines we present an algorithm with a worst‐case ratio close to 3/2, and close to 3, if a job can be given several units of the resource. For the problem with a fixed number of machines we give a PTAS. Virtually all algorithms rely on a certain variant of the linear knapsack problem (maximization, minimization, multiple‐choice, bicriteria). © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

高校资源环境类专业开设资源与环境法课程的意义

资源与环境法是高校法学类的核心课程，目前，该课程已经逐渐在资源环境类专业中不同程度的开设。高校资源环境类专业开设资源与环境法课程是非常必要而且很有意义的，（1）文章从开设资源与环境法课程有助于强化学生的环境法制教育；（2）开设资源与环境法课程有助于完善资源环境类专业的学科体系；（3）开设资源与环境法课程有利于大学生参与保护环境的实践活动；（4）开设资源与环境法课程有助于学生了解常识；（5）资源环境法课程的开设有利于丰富教学授课形式等5个方面论证了其意义性。     

基于网格技术的仿真资源实时调度系统研究与实现

针对仿真资源服务运行中存在的性能瓶颈,以WSR工厂模式为基础,设计并实现了一种基于网格技术的仿真资源实时调度系统。该系统通过设置代理工厂服务,在客户端创建资源实例,实现了对仿真资源服务的实时动态调度和对资源属性的监控。原型实验证明,该系统具有调度时机合理、调度机制对服务方与客户端透明、资源监控机制不影响客户端操作和接口开放等优点。     

新疆民俗数学文化探析

新疆民俗数学是具有鲜明民族特色、独特价值和丰富文化内涵的数学思想与思维方式的综合。新疆民俗数学较多地体现在用于造型和装饰的清真寺、民居、民族手工艺品等方面的几何纹饰上。对于民俗数学的研究，一方面是通过对这些集数学知识与传统文化于一体的“文化载体”的搜集、整理和分析，分析其蕴含的数学知识和数学思想；另一方面则关注民俗数学研究成果的教育学转化，在充分考虑新疆少数民族儿童数学认知思维特征以及数学双语教学原则、方法等的基础上，通过实现民俗数学的“课程化”，以弥补当前新疆少数民地区以“主流文化”为主导的数学课程对少数民族传统文化的“缺失”，进而推进本地区基础教育课程改革和数学教育质量的提升。