一类多车场集送货一体化问题的最优调度研究

针对江浙沪一带中小型配送中心提供集送货一体化服务增多、运营成本增加这一现象,通过建立该配送类型的车辆调度模型,然后利用分派启发式算法和改进的节约算法设计混合启发式算法来解决这一类问题。并给出算例,验证该算法的可操作性。     

Impact of metal silos on households’ maize storage,storage losses and food security: An application of a propensity score matching

Maize is the most important food staple in Eastern and Southern Africa, with a highly seasonal production but relatively constant consumption over the year. Farmers have to store maize to bridge seasons, for food security and to protect against price fluctuations. However, the traditional storage methods do not protect grain well, resulting in large postharvest losses. Hermetically sealed metal silos kill storage pests by oxygen deprivation without pesticides. Popular in Central America, they are now being promoted in Africa, but their impact here has not yet been studied. This study used propensity score matching to evaluate the impact of metal silos on duration of maize storage, loss abatement, cost of storage, and household food security. Metal silo adopters (N = 116) were matched with non-adopting farmers from a representative sample of 1340 households covering the major maize-growing zones in Kenya. The major effect of the metal silos was an almost complete elimination of losses due to insect pests, saving farmers an average of 150–200 kg of grain, worth KSh9750 (US$130). Metal silo adopters also spent about KSh340 less on storage insecticides. Adopters were able to store their maize for 1.8–2.4 months longer, and to sell their surplus after five months at good prices, instead of having to sell right after the harvest. The period of inadequate food provision among adopters was reduced by more than one month. We conclude that metal silos are effective in reducing grain losses due to maize-storage insects, and that they have a large impact on the welfare and food security of farm households. The initial cost of metal silos is high (KSh20,000/1.8 ton) and therefore policies to increase access to credit, to reduce the cost of sheet metal, and to promote collective action can improve their uptake by smallholder farmers.     

电子书店中的用户角色分配自动化

在大型电子商务系统中,从用户到角色进行人工分配代价巨大,且容易出现错误的角色分配,文章以一个电子书店中的用户角色分配为基础,详细介绍了基于属性与约束的用户角色自动分配的设计与开发实现过程。     

New batch construction heuristics to optimise the performance of order picking systems

Two new batch construction heuristics called K-means Batching (KMB) and Self-organisation Map Batching (SOMB) are developed and verified by simulation experiments. Both KMB and SOMB have a preferment of superior performance in total travel distance and average picking vehicle utility, and even a conspicuous improvement in total CPU running time. Besides, this paper investigates the overall performance of order picking systems integrating storage assignment, order batching and picker routing to find the optimal policy combinations under different order types. The sensitivity analysis is performed to distinguish the relative importance of the various strategies to enhance the performance of operations management.     

项目教学法在机械装配与维修专业中应用的研究

项目教学法是以建构主义理论为基础,通过选取"项目"来创设"情景",通过"协作学习"的方式开展学习,通过完成"项目"来达到"意义建构",是一种比较有效的教学方法。本文对在机械装配与维修专业中实施项目教学法进行了研究,并对整个教学方案进行了设计,为下一步实施项目教学奠定了理论基础。     

云存储网盘综合性能评定

网盘是网络与存储技术结合的产物,已成为企业和个人存储和共享信息资源的重要工具,云存储技术的应用与无线网络的普及,为网盘发展带来了新前景。目前,国内外网盘品牌颇多且各具特色,本文选择国内现流行的五款产品,运用层次分析法评定其综合性能,发现高传输速度为网盘商带来竞争优势。     

基于ESCP范式下的我国新能源储能产业发展战略研究

在分析我国新能源储能产业发展现状的基础上,试图从产业环境和政府政策角度出发,改进并运用SCP框架,对当前我国新能源储能产业环境、市场结构、运营商策略行为、市场绩效以及储能产业政策进行综合分析。分析表明,目前我国新能源储能产业虽取得了一定的发展,但仍存在的国家重视力度不够、产业集中度过高、进入壁垒大、投资回报机制不健全技术人才缺乏、科技创新资金投入不足及产业规模偏小等问题,因此只有发现发展过程中所存在的问题,才能为储能产业的高效、健康、持续发展提供相关建议并制定出我国新能源储能产业发展战略。     

房地产财富效应对社会财富分配的影响分析

随着房地产资产在居民家庭总资产中所占的比重日益提高,其在社会财富的新一轮分配中起着决定性的影响。本文通过分析房地产财富效应对社会财富分配的影响,提出房地产资产价格上涨的财富效应拉大居民财富分配差距,是造成贫富差距进一步扩大的重要原因之一,最终将对宏观经济增长产生影响。因此必须关注房地产市场财富效应对社会财富分配的影响,既要根据宏观经济平衡的要求保持房地产行业的稳定与合理发展,也要从社会和谐稳定的高度来调节房地产在居民财富分配过程中的作用。     

iSDS: a self-configurable software-defined storage system for enterprise

ABSTRACT

Storage is one of the most important aspects of IT infrastructure for various enterprises. But, enterprises are interested in more than just data storage; they are interested in such things as more reliable data protection, higher performance and reduced resource consumption. Traditional enterprise-grade storage satisfies these requirements at high cost. It is because traditional enterprise-grade storage is usually designed and constructed by customised field-programmable gate array to achieve high-end functionality. However, in this ever-changing environment, enterprises request storage with more flexible deployment and at lower cost. Moreover, the rise of new application fields, such as social media, big data, video streaming service etc., makes operational tasks for administrators more complex. In this article, a new storage system called intelligent software-defined storage (iSDS), based on software-defined storage, is described. More specifically, this approach advocates using software to replace features provided by traditional customised chips. To alleviate the management burden, it also advocates applying machine learning to automatically configure storage to meet dynamic requirements of workloads running on storage. This article focuses on the analysis feature of iSDS cluster by detailing its architecture and design.     

中国粮食仓储的历史与展望

粮食仓储作为中国历史发展中的重要载体,对于社会的繁荣、稳定和发展具有重要意义。本文主要论述了中国古代和现代粮食仓储的发展历史及其价值,并对粮食仓储未来的发展进行展望。