Storage Life Prediction for a High-Performance Capacitor Using Multi-Phase Wiener Degradation Model

Capacitance is a critical performance characteristic of high-voltage-pulse capacitor which is used to store and discharge electrical energy rapidly. The capacitors usually are stored for a long period of time before put into use. Experimental result and engineering experience indicate that the capacitance increases with storage time and will eventually exceed the failure threshold, which means that the capacitor may fail during storage. This is a typical mode of degradation failure for long storage products. Further, the capacitance degradation path can be extrapolated in several stages based on the shifting characteristics. That is, the capacitance increases slowly or fluctuates in the initial storage stage that lasts about three months. Then it increases sharply in the middle stage which lasts about four months. After the two stages, the capacitor enters into the third stage in which capacitance increases constantly. This degradation phenomenon motivates us to study the storage life prediction method based on multi-phase degradation path model. The storage performance degradation mechanism of high-voltage-pulse capacitor was investigated, which provides the physical basis for multi-phase Wiener degradation model. Identification procedure for the transition points in the degradation path was proposed using maximum likelihood principle (MLP). The result of Kruskal-Wallis test which is the method to test whether two populations are consistent or not in statistics showed that the transition points are statistically effective. Other parameters in the multi-phase degradation model are estimated with maximum likelihood estimation (MLE) after the transition points have been specified. The multi-phase Inverse Gaussian (IG) distribution for storage life was deduced for the capacitor, and the point and interval estimation procedure for reliable storage life are constructed with bootstrap method. The efficiency and effectiveness of the proposed multi-phase degradation model is compared with storage life prediction under single-phase condition.     

Multi-item EOQ inventory model with varying holding cost under two restrictions: A geometric programming approach

In this paper we provide a simple method to determine the inventory policy of multiple items having varying holding cost using a geometric programming approach. The varying holding cost is considered to be a continuous function of the order quantity. The EOQ inventory model with constant holding cost and the classical EOQ inventory model without constraints are derived.     

基于政府与企业合作的应急物资存储成本控制问题的研究

本文针对政府储备应急物资过期报废损失严重、存储成本高的问题,提出了政府委托企业储备应急物资的方案,并对委托合作后政府如何激励企业降低应急物资存储成本的问题进行了研究。首先对政府与企业合作前后应急物资储备成本进行了分析,寻找能使节约成本公平分配的条件,继而在企业尽最大努力降低应急物资存储成本的条件下,建立了政府成本节约期望效用最大化的激励模型。最后用算例验证了政府和企业合作后存储成本控制的问题。     

我国高校教材《粮油储藏学》编印历史探讨

简述了我国粮食储藏学科的建立、建设及发展过程,介绍了原苏联和美国粮食储藏学科专业教材的建设情况。对我国粮油储藏学教材与美国和前苏联的粮油储藏学教材进行了比较分析。     

Storage constrained vendor managed inventory models with unequal shipment frequencies

We consider a supply chain where a vendor manages its multiple retailers' stocks under a vendor managed inventory (VMI) contract that specifies upper stock limits at the retailers' premises and overstock costs for exceeding those limits. We formulate a mixed integer nonlinear program that minimizes total supply chain costs and allows unequal shipment frequencies to the retailers. We develop an algorithm to solve its relaxed version which provides a lower bound cost solution. We propose a cost efficient heuristic procedure to generate delivery schedules to the retailers. We conduct a sensitivity analysis to provide insights on the performance of the proposed heuristic. Results show that our heuristic finds optimal or near optimal solutions, and it proposes substantial savings compared to the total supply-chain cost in the cases where there is no VMI and where there is VMI but with equal shipment frequencies to retailers.     

“守藏之史”与老子的法律思想

根据西周金文和周代文化考古的成果,结合文献研究,可发现老子在西周担任过柱下史职务,就是御史,后改任收藏史,负责盟誓、法律法规的管理工作,都是司法职事。晚年,他著《老子》一书,其中充满了批判精神,也包含着丰富的法律哲学和思想。他的法律思想的核心是天下有道,法制理想是善政爱政,提倡做人、为政都要“正”,认为战争和犯罪的根源是社会的不公平。老子很多的法哲学见识,如“天网恢恢,疏而不漏”等,至今仍有意义。     

论王安石对宋代常平仓的改革及影响

常平仓是古代一重要仓储 ,王安石变法前未能很好地发挥其社会调控之实效。因之 ,王安石对其收入来源、支出方式、管理制度和运作办法等 ,进行了一番大胆改革。这些改革措施基本上克服了常平仓原有的弊端 ,促进了社会的发展 ,产生了深远的影响     

Assembly block storage location assignment at a shipyard: a case of Hyundai Heavy Industries

It is not a trivial issue how to manage assembly blocks at a shipyard. Based on the project experience in Hyundai Heavy Industries, currently the largest shipbuilding company in the world and the leader in the Korean merchant shipbuilding industry, this study points out the difficulties on the block stockyard operations, formalises the assembly block storage location assignment problem, and develops the assembly block storage location assignment algorithm, the purpose of which is to reduce the number of unproductive block moves. Through simulation experiments for various situations, this study demonstrates the usefulness of the assembly block storage location assignment algorithm. In addition, this study examines the impacts of block move sequence rules and of block stockyard layouts on the block stockyard operations.     

组块学习策略的本质属性

本文探讨以汉语为母语的英语词汇组块策略的本质属性：实用性，联系性，分解性和习惯性，得出组块策略符合认知原理。     

喷树增产耐贮剂对沙糖桔果实生长成熟期的影响

以沙糖桔为材料,在果实转色期喷施“喷树增产耐贮剂”．与对照组相比,该处理可增加果实成熟期可溶性糖和可溶性固形物的含量。增幅分别为8．5％和8．9％;同时,显著减少了维生素c的降幅,比对照组低了16．26％．经喷施耐贮荆处理60d后,处理组比对照组可溶性糖含量增加了8％,可溶性固形物增加了10％,维生素c增加了20％．果实与果径生长动态分析表明：经“喷树增产耐贮剂”处理后21~40d的果径生长速率与对照组相比差异显著,采果时经过处理的果树单果质量显著增加,采果时的落果率显著减少．