带缓冲区且产品保修的设备预防性维护建模

论文考虑的是一个完美的生产系统,即生产系统所生产的产品均没有质量问题。为提高设备的可靠性,调整市场需求,提出带缓冲区的设备预防性维护优化建模方法。已经出售的产品,顾客在使用过程中可能会出现故障,基于这个情况,在保修期内会予以免费维修。找出生产系统的运行时间(T)和缓冲区库存量(S),以此为决策变量建立期望成本模型。在此基础上,构造求解最优策略的算法。通过数值算例演示了该模型,通过灵敏度分析确定了最优策略和相关参数的关系。     

信息化项目建设中的全过程评价研究

信息化项目评价是一个完整的过程，包括事前的评估，事中的计划与控制，以及事后的评价过程，融合于项目整个建设过程之中，与项目建设过程完全协同。评价的目的不仅仅在于对效益的判断与衡量，更重要的是为项目建设提供指导，成为提高项目管理效率的手段之一，通过对全过程评价三个大环节的分析认为，以预期目标体系为核心的全过程评价，可以促进信息化项目效益的最大化。     

Hybrid surrogate-model-based multi-fidelity efficient global optimization applied to helicopter blade design

A multi-fidelity optimization technique by an efficient global optimization process using a hybrid surrogate model is investigated for solving real-world design problems. The model constructs the local deviation using the kriging method and the global model using a radial basis function. The expected improvement is computed to decide additional samples that can improve the model. The approach was first investigated by solving mathematical test problems. The results were compared with optimization results from an ordinary kriging method and a co-kriging method, and the proposed method produced the best solution. The proposed method was also applied to aerodynamic design optimization of helicopter blades to obtain the maximum blade efficiency. The optimal shape obtained by the proposed method achieved performance almost equivalent to that obtained using the high-fidelity, evaluation-based single-fidelity optimization. Comparing all three methods, the proposed method required the lowest total number of high-fidelity evaluation runs to obtain a converged solution.     

Crashworthiness optimization of honeycomb structures under out-of-plane impact using radial basis functions

Crashworthiness design and development of lightweight structures have become important engineering challenges because of the high standards of energy consumption and safety regulations. Within this context, the use of honeycomb structures as crush absorber is continuously growing in automotive and aircraft industries, once honeycombs are known for their high strength-to-weight ratio and excellent energy absorbing capacity. Thus, this paper presents a method that combines radial basis functions with expected improvement to optimize the specific energy absorption of honeycomb cellular materials, while the peak crush force is constrained at low levels for safety reasons. Honeycomb's cell size, cell shape and thickness are the design variables. Concerning the cell shape, the results indicate the hexagonal configuration has a higher out-of-plane performance compared to auxetic and rectangular cells in terms of energy absorption capacity. Lastly, a multi-objective optimization using only the radial basis function predictor (without sequential sampling) is carried out to seek simultaneously for optimal solutions with minimum peak force and maximum specific energy absorption.     

Conditional mean- and median-based cumulative sum control charts for Weibull data

This article deals with the monitoring of censored data using the cumulative sum (CUSUM) control charts for Weibull lifetimes under type-I censoring. To develop an efficient CUSUM structure for censored data, we use the conditional expected value (CEV) and conditional median (CM) approaches. In particular, we focus on the detection of shifts in the mean of Weibull lifetimes assuming censored data. In addition to fixed/known parameter values, the effect of estimation is assessed on the detection power of control charts. The performance of the proposed charts is evaluated by the average run length (ARL). Furthermore, the ARL performance of CUSUM charts is compared with CEV- and CM-based exponentially weighted moving average (EWMA) control charts. Besides an extensive simulation study, the significance of the current work is illustrated by a data set on the response time of a thermostat experiment.     

基于免疫蜂群算法的冷轧生产调度优化方法

冷轧生产调度是一个复杂的约束组合优化问题,生产约束包括轧制板坯的宽度、厚度、硬度跳变及交货期提前和拖后惩罚等。基于1．sP（多旅行商）问题,建立了冷轧生产调度问题的最小值模型,提出了一种免疫蜂群优化求解算法。通过给蜂群注射疫苗产生出代表新的解集的种群,避免算法在优化过程中陷于局部极值。针对工业数据的仿真结果表明：免疫蜂群优化算法明显优于人工蜂群优化算法的解,具有较好的收敛性和快速性。     

基于收益法评估企业价值的评估指标性质及选择

在企业价值评估中,企业未来收益额、收益期及折现率是关键指标。在对各项指标的性质进行分析的基础上,重点运用GM（1,1）模型对企业未来收益额的预测进行探讨,同时对折现率的测算方法进行对比分析,并指出各项评估指标确定方法的合理选择。     

我国城镇居民可支配收入与消费支出的灰色关联分析

应用灰色关联分析方法,研究了1990年～2004年和2006年～2009年两个阶段我国城镇居民消费支出与可支配收入之间的关系.根据灰色分析显示,在1990年～2004年间,与人均可支配收入变化曲线的几何形状相似程度较高的消费支出项目依次为衣着类、家庭设备、用品及服务类和食品类,杂项商品与服务类排第5位,居住类位居第6位...     

一种优化型电网故障诊断的实用改进模型

基于保护和断路器状态信息的优化型故障诊断,是目前为止为数不多的已有实际应用的诊断方法.对经典的优化型故障诊断模型进行了深入分析,找出了其中的不足.然后在只基于保护和断路器状态信息的情况下,提出了在保证不漏判的前提下尽量减少误判的诊断原则.通过对现有模型和断路器期望表达式的改进,达到了这一目标,解决了原有模型在警报信息丢...     

城市低保制度目标定位过程中的家计调查及方法改进

城市低保制度目标定位过程中家计调查方法对提高制度目标定位效率发挥了巨大作用,但尚需进一步改进与调整。文章从目标定位及家计调查的理论基础出发,论述了现行城市低保制度的家计调查方法的应用及存在的主要问题,最后提出改进家计调查方法并进一步提高城市低保制度目标定位效率的对策。