膨润土-砂混合型缓冲／回填材料液塑限试验

为研究掺砂率对高庙子膨润土一砂混合型缓冲／回填材料液塑限的影响,利用液塑限联合测定仪进行了试验研究,并运用最小二乘法对混合物液塑限试验数据进行了分析。试验结果表明膨润土一砂混合物的可塑性、液塑限值和塑性指数均随掺砂率的增大而降低。对试验结果进行分析,得到了考虑掺砂率影响的混合物液塑限经验公式。混合物的液塑限并不是随掺砂率增大成比例降低,而是液限的实测值小于理论值,塑限的实测值大于理论值。得到的不同掺砂率的膨润土一砂混合型缓冲／回填材料液塑限试验数据可为高放废物深地质处置库建设提供科学依据。     

一例多元案例教学法在程序设计课程教学中的应用

通过探讨一例多元案例教学法的教学理念、设计策略、实施方法和过程,解决程序设计课程教学不能点、线、面融合,缺少培养学员设计综合应用程序能力的方法和手段,学员学习目标不明确、缺乏学习兴趣等问题,以有效提高教学效果和质量.     

Progress payments and cost overruns in defence contracts

In recent years military procurement agencies have used “progress payments” in contracting. Although, overall, the adoption of such a policy may well have contributed to a decrease in total costs of procurement, we identify a class of inefficiencies that are likely to have been generated by it.     

基于Gauss伪谱法的空空导弹最优中制导律设计

研究Gauss伪谱法在空空导弹最优中制导律设计中的应用。建立空空导弹中制导律设计问题最优控制模型,首次提出采用Gauss伪谱法求解最优中制导律设计问题的思路,详细阐述了求解流程,通过仿真算例验证了求解方法的有效性,并同比例导引、打靶法等传统方法进行了对比。仿真结果表明,综合考虑性能指标、计算精度、计算效率等因素,Gauss伪谱法具有明显优势,Gauss伪谱法求解结果和求解效率与配点个数密切相关。研究结果为空空导弹中制导律设计提供理论参考。     

层次分析法的水下航行器维修性指标分配方法

基于层次分析法的水下航行器维修性指标分配方法把层次分析法应用到水下航行器维修性指标分配方法中,即邀请专家对故障的检测和隔离方式、可达性、可更换性和测试的困难等级进行两两比较,得到评价矩阵,据此,可以得到分配结果.这种方法克服了按故障率和设计特性分配法在设计特性相差不大时存在的缺陷,把定性分析与定量分析相结合.在设计初期即明确设计目标,除了考虑到单元的故障率还兼顾了初期设计过程中的不确定性.将这种方法应用于某水下航行器的维修性分配,结果表明,该方法具有实用价值.     

方舱式指挥自动化系统的防护与伪装总体设计

针对不同战争形态下方舱式指挥自动化系统的生存问题,分析了其在未来战场将面临的主要问题,研究了在总体设计阶段提高未来战场生存能力的对策,提出了总体设计思路和技术措施.     

基于试验设计方法的有限元仿真参数优化

根据仿真建模VVA的原则,为将仿真试验误差分解、控制在有限元分析的每个阶段,引入正交试验设计理论,对侵彻仿真试验方案进行组配、评估及优化,确定了有限元仿真的最佳参数设置。     

Outbound supply chain network design with mode selection and lead time considerations

We present a large‐scale network design model for the outbound supply chain of an automotive company that considers transportation mode selection (road vs. rail) and explicitly models the relationship between lead times and the volume of flow through the nodes of the network. We formulate the problem as a nonlinear zero‐one integer program, reformulate it to obtain a linear integer model, and develop a Lagrangian heuristic for its solution that gives near‐optimal results in reasonable time. We also present scenario analyses that examine the behavior of the supply chain under different parameter settings and the performance of the solution procedures under different experimental conditions. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

On optimal system designs in reliability‐economics frameworks

Reliability Economics is a field that can be defined as the collection of all problems in which there is tension between the performance of systems of interest and their cost. Given such a problem, the aim is to resolve the tension through an optimization process that identifies the system which maximizes some appropriate criterion function (e.g. expected lifetime per unit cost). In this paper, we focus on coherent systems of n independent and identically distributed (iid) components and mixtures thereof, and characterize both a system's performance and cost as functions of the system's signature vector (Samaniego, IEEE Trans Reliabil (1985) 69–72). For a given family of criterion functions, a variety of optimality results are obtained for systems of arbitrary order n. Approximations are developed and justified when the underlying component distribution is unknown. Assuming the availability of an auxiliary sample of N component failure times, the asymptotic theory of L‐estimators is adapted for the purpose of establishing the consistency and asymptotic normality of the proposed estimators of the expected ordered failure times of the n components of the systems under study. These results lead to the identification of ε‐optimal systems relative to the chosen criterion function. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

谈课件设计中的人文关怀

课件设计制作已经成为教学工作的重点。它将教学经验、语言文字和虚拟现实融为一体,能够较好地满足不同兴趣、不同特长的学生学习需要,有利于促进学生的全面发展。然而,这种形式又使师生之间产生了一定距离,所以在课件设计制作中如何实现人文关怀成为信息化教学设计的重要课题。