On constructions for two dimensional balanced sampling plan excluding contiguous units with block size four

Balanced sampling plans excluding contiguous units (BSEC) were first introduced in 1988 by Hedayat, Rao and Stufken [A.S. Hedayat, C.R. Rao, J. Stufken, Sampling plans excluding contiguous units, J. Statist. Plann. Inference 19 (1988) 159-170]. These designs can be used for survey sampling when the contiguous units provide similar information. In this paper, we show some recursive constructions for two dimensional BSECs with block size four, and give the existence of some infinite classes.     

MIL-STD-1916中连续抽样方案的流向图方法

本文把转移概率流向图和转移概率母函数的方法引入到对MIL-STD-1916中连续抽样方案的讨论中,给出了抽样方案的平均检出质量函数AOQ,抽查特性函数L(p)和平均检查比率函数AFI全部3项指标的理论推导,为进一步探讨带有停止检查的MIL-STD-1916中连续抽样方案及相应的动态检出质量提供了理论基础。     

Optimal management of DC pension plan under loss aversion and Value-at-Risk constraints

This paper studies the risk management in a defined contribution (DC)pension plan. The financial market consists of cash, bond and stock. The interest rate in our model is assumed to follow an Ornstein–Uhlenbeck process while the contribution rate follows a geometric Brownian Motion. Thus, the pension manager has to hedge the risks of interest rate, stock and contribution rate. Different from most works in DC pension plan, the pension manger has to obtain the optimal allocations under loss aversion and Value-at-Risk(VaR) constraints. The loss aversion pension manager is sensitive to losses while the VaR pension manager has to ensure the quality of wealth at retirement. Since these problems are not standard concave optimization problems, martingale method is applied to derive the optimal investment strategies. Explicit solutions are obtained under these two optimization criterions. Moreover, sensitivity analysis is presented in the end to show the economic behaviors under these two criterions.     

基于灰色理论和效费比的装备保障方案优选

针对目前装备保障方案优选决策出的方案并不一定是最科学的情况,同时考虑到保障方案中存在小样本数据和数据不确定的因素,提出基于灰色理论和效费比的装备保障方案优选方法,方法着重强调了效费比在决策评判中作用,以免遗漏科学符合工程实践的保障方案.案例分析表明,方法值得在工程实践中借鉴.     

数字化预案中基于中介逻辑的不确定事件表示

突发公共事件本身的不确定性以及紧急状态下信息采集的时空局限性,要求数字化预案对不确定事件进行有效地表达.基于中介逻辑,研究了不确定事件的有效表示及不确定程度的度量,采用区间代数方法对不确定事件进行了表示,建立了一维和n维情形下不确定事件的不确定程度的度量模型.在此基础上,利用中介逻辑对数字化预案中应急响应规则进行表达,对具体算例进行了分析,初步验证了该模型的有效性.     

基于集团属性的计数型抽样检验及其研究进展

本文以家蚕微粒子病集团母蛾抽样检验的历史背景为线索,介绍了基于集团属性的计数型抽样检验的概念、OC函数及其算法的研究进展,以及在农业产品质量控制中的应用和意义,同时指出集团抽样检验的应用前景和今后需要解决的问题。     

STRENGTH CRITERION FOR PLAIN CONCRETE UNDER MULTIAXIAL STRESS BASED ON DAMAGE POISSON''S RATIO

A new unified strength criterion in the principal stress space has been proposed for use with normal strength concrete (NC) and high strength concrete (HSC) in compressioncompression-tension, compression-tension-tension, triaxial tension, and biaxial stress states. The study covers concrete with strengths ranging from 20 to 130 Mpa. The conception of damage Poisson's ratio is defined and the expression for damage Poisson's ratio is determined basically.The failure mechanism of concrete is illustrated, which points out that damage Poisson's ratio is the key to determining the failure of concrete. Furthermore, for the concrete under biaxial stress conditions, the unified strength criterion is simplified and a simplified strength criterion in the form of curves is also proposed. The strength criterion is physically meaningful and easy to calculate, which can be applied to analytic solution and numerical solution of concrete structures.     

具有惩罚因子的模糊集约生产计划

研究基于模糊环境下的集约生产计划问题,并设计了带有惩罚因子的模糊优化模型,以实现生产费用和惩罚费用之和最小.通过模糊变量和模糊等式定义的描述,简化了模型,并给出机会约束规划方法进行模型求解的整体步骤.通过仿真结果和灵敏度分析,表明模型和方法的有效性,并为决策者在模糊环境下的决策提供支持.     

近邻型风景旅游集镇规划的若干问题剖析

建设风景区旅游集镇既可以保护风景区的旅游资源,又可以促进集镇发展.根据风景区与旅游集镇的空间关系,对旅游集镇进行了类型上的划分.并以近邻型旅游集镇为研究对象,提出了编制近邻型旅游集镇规划所需解决的人口规模、功能布局、集镇特色和规划弹性4个关键问题;最后以西天目山风景区旅游集镇(白鹤)总体规划为例,阐述了解决上述问题的方法和手段.