THE CHOICE OF CELLS IN CHI–SQUARE TESTS

The choice of cells in chi–square goodness of fit tests is a classical problem. Some recent results in this area are discussed. It is shown that the likelihood ratio of alternatives w.r.t. null distributions plays a key role when judging different procedures. The discussion centers on the case of a simple hypothesis, but location–scale models and tests of independence in contingency tables are also considered.     

高标清混合视频监控系统的设计与实施

分析了机车制造企业目前视频监控系统的现状和新的需求,针对机车制造企业的行业特点设计了高标清混合视频监控系统,在设计和实施中应用了高清视频监控的最新技术,同时做到了与原有标清视频监控系统的兼容。给出了具有一定使用价值的高标清混合视频监控系统的逻辑结构、系统总体结构和网络拓扑结构,提出了旧的视频监控系统在升级改造中应该注意的问题。     

Smallholder Demand for Maize Hybrids in Zambia: How Far do Seed Subsidies Reach?

We add to an emerging body of literature on input subsidies in Africa south of the Sahara. Our analysis focuses on demand for seed, characterising smallholders with a high predicted demand for hybrid seed who were not reached by the subsidy programme. We use cross‐sectional data from the 2010 agricultural season and an instrumented control function approach to test the hypothesis that the subsidy on hybrid maize seed in Zambia is selectively biased. Consistent with other literature, we find that the subsidy is a recursive determinant of seed demand, but in 2010, its recipients had more land, more assets, and lower poverty rates. Findings illustrate the social costs of the programme as currently designed and highlight the need to build alternative supply channels if poorer maize growers are to grow hybrid seed.     

流水工序调度与生产效率的关系模型分析

提出一种基于粒子群算法的流水工序调度任务优化模型。利用流水工序调度任务的特点得到流水工序时间约束条件,利用粒子群算法的原理建立流水工序调度任务优化模型,利用粒子群算法对模型进行求解。仿真实验表明,利用该算法能够得到流水工序调度问题的最优解,提高生产效率。     

考虑多类型产品新鲜度的生鲜配送路径优化

生鲜产品由于其特殊性,在配送过程中存在损耗。针对不同种类的生鲜产品,差异化新鲜度敏感系数,引入生鲜努力保鲜系数,构建生鲜产品新鲜度函数,同时考虑固定成本、运输成本、制冷成本、货损成本及时间惩罚成本,构建了生鲜配送路径优化模型。设计混合遗传粒子群算法进行求解,验证了模型的合理性及算法的有效性。对比不同的生鲜努力保鲜系数对各项成本的影响,得出综合成本最优的保鲜策略,为生鲜企业末端配送优化提供参考。     

血管内皮细胞功能与动脉粥样硬化的研究进展

随着近年来对血管内皮细胞生物功能的认识不断深入,目前被普遍接受的Ross修正的"损伤反应"学说认为,内皮细胞功能障碍是动脉粥样硬化形成早期的始动环节。本文就内皮功能与动脉粥样硬化的关系的研究进展作一综述。     

电子商务背景下城市宅配模式的创新研究

随着我国电子商务的发展,对物流配送行业的要求越来越高。针对我国物流配送行业存在的主要问题,在分析现有模式的基础上,提出“混合第四方”的宅配模式,从模式、功能、优势及第四方服务点选址原则四个维度进行电子商务背景下城市宅配模式创新研究以期解决物流配送的短板效应,进一步促进我国物流配送行业和电子商务的发展。     

Integration of hybrid wireless networks in cloud services oriented enterprise information systems

This article presents a hybrid wireless network integration scheme in cloud services-based enterprise information systems (EISs). With the emerging hybrid wireless networks and cloud computing technologies, it is necessary to develop a scheme that can seamlessly integrate these new technologies into existing EISs. By combining the hybrid wireless networks and computing in EIS, a new framework is proposed, which includes frontend layer, middle layer and backend layers connected to IP EISs. Based on a collaborative architecture, cloud services management framework and process diagram are presented. As a key feature, the proposed approach integrates access control functionalities within the hybrid framework that provide users with filtered views on available cloud services based on cloud service access requirements and user security credentials. In future work, we will implement the proposed framework over SwanMesh platform by integrating the UPnP standard into an enterprise information system.     

太阳能光伏发电的设计应用

传统能源的使用导致国际能源危机及环境污染的问题日渐严重,光伏太阳能作为一种新型能源,备受许多国家和地区关注。如何在建筑产业合理利用太阳能光伏发电,对光伏产业的发展具有重要的意义。文章结合多年来国内外太阳能光伏发电的应用推广情况,参考相关国家、行业标准及技术文献,结合广西美术馆项目的实际情况,分析光伏发电的技术特点,对如何进行太阳能光伏发电的设计选行介绍,并总结了目前光伏太阳能发电的优缺点及未来发展趋势。     

高效率长寿命太阳能节能照明系统的研究

针对目前市场上的太阳能照明灯存在“低效率、短寿命、高成本”（即“两低一高”）的缺点,提出了“超高亮度LED灯具”、“太阳强光实时自动跟踪装置”、“低光照度时仍能充电的变换器”、“低功耗的LED驱动／集成芯片”和“主辅LED工作模式”等解决方案,经试验,均取得令人满意的效果。