主成分分析—BP神经网络在备件需求预测中的应用

备件需求预测在装备维修保障中占据重要的地位,针对当前主要以经验为主进行估计,与实际需求相差较大,提出基于主成分分析—BP神经网络模型的备件需求预测方法。首先利用主成分分析方法去除原始输入数据的相关性,降低数据维度,减小网络规模,选择合适的隐含层的BP神经网络。最后通过结合实例进行分析,取得较好的效果。     

食品追溯及其体系设计与实施的原则和要求

对食品进行全过程追溯是当今世界食品安全监管的发展趋势。文章分析了国内外食品追溯现状,并以IS022005：2007为指导,介绍了食品追溯体系设计与实施的原则和要求,最后,就加快我国食品追溯体系的建设及实施提出了建议。     

Reserve modelling and the aggregation of risks using time varying copula models

This paper is concerned with the appropriate claim reserving modelling and aggregation of risks in the insurance sector. In fact, literature review provided some methods to evaluate the total amount of reserves and solvency capital of different lines of business. However, these models were derived under the independent losses assumption. Thus, the total amount of reserves and capital may be inaccurate when losses are dependent, as it is the case in practice. In this paper, a novel model is proposed aiming to handle temporal dependence, both between a line of business claim's amounts and between the two lines of business claims. Generalized Autoregressive Conditional Sinistrality model is used to analyze the evolution in time of dependence and time varying copula functions are proposed to aggregate risks. To achieve such purpose, a simulation study, highlighting the impact on reserves and Solvency Capital Requirement, is performed. Results revealed that a diversification effect could be gained on the Solvency Capital when considering time varying dependence structures.     

Working capital requirement and the unemployment volatility puzzle

Shimer (2005) argues that a search and matching model of the labor market in which wage is determined by Nash bargaining cannot generate the observed volatility in unemployment and vacancy in response to reasonable labor productivity shocks. This paper examines how incorporating monopolistically competitive firms with a working capital requirement (in which firms borrow funds to pay their wage bills) improves the ability of the search models to match the empirical fluctuations in unemployment and vacancy without resorting to an alternative wage setting mechanism. The monetary authority follows an interest rate rule in the model. A positive labor productivity shock lowers the real marginal cost of production and lowers inflation. In response to the fall in price level, the monetary authority reduces the nominal interest rate. A lower interest rate reduces the cost of financing and partially offsets the increase in labor cost from a higher productivity. A reduced labor cost implies the firms retain a greater portion of the gain from a productivity shock, which gives them a greater incentive to create vacancies. Simulations show that a working capital requirement does indeed improve the ability of the search models to generate fluctuations in key labor market variables to better match the U.S. data.     

Requirement analysis and service optimization of multiple category fresh products in online retailing using importance-Kano analysis

Online fresh retailing enriches people's shopping choices and provides convenience to reduce the risk of infection during the pandemic. Online reviews contain consumers' attention, requirements and sentiments, and in-depth analysis of this information has guiding values for service optimization. To better understand this information, a requirement analysis idea based on the attention and sentiment distribution of online reviews was proposed, namely importance-Kano analysis. Seven different customer requirements were found, including express delivery, cost performance, communication, freshness, flavor, specification and packaging. Flavor and freshness are the most concerned attributes, and they and other attributes all influence satisfaction in their unique ways. Consumers care a lot about the shopping experience and product quality and they have a high degree of product involvement in fresh products. Service improvement should be considered as a systematic project, and the influence of competitive environment, category differences and technological development should not be ignored. A service optimization model was developed based on the concept of total quality management, which was constructed by three layers including supply chain, operation management and consumer experience. The systematic analysis is conducive to in-depth understanding of the complexity, systematical and timeliness nature of fresh product operation management.     

油井管的质量缺陷及其预防

介绍了油井管的质量要求,指出了油井管在生产过程中的质量缺陷,主要有管体本身的缺陷（理化性能不符合要求、无损探伤不符合要求、几何尺寸超差和通径不合格）、表面缺陷（裂纹、内折、外麻坑和表面擦伤等）和螺纹缺陷（黑皮扣、颤纹、乱扣和螺纹参数超标等）,分析了质量缺陷产生的原因,并提出了缺陷的预防及处理措施。     

动画人才需求现状及高职动画教育教学改革

我国作为一个动画产业刚刚起步的制作大国,产业人才的匮乏已直接影响到我国动画产业链的快速发展。高职院校作为动画产业人才主要供给渠道之一,由于教育方式诸方面的因素,培养出来的动画专业人才相当一部分难以满足动画企业的岗位需求。本文依据动画产业发展现状以及高职教育方式等因素,对动画专业人才培养过程中存在的问题,提出改善建议,包括开放与合作办学,人才培养目标等,依据中国动画产业可持续发展路径,力求建立科学有序地动画人才培养体系,为动画企业输送适用人才。     

从读者需求谈高职院校图书馆的建设

高职院校图书馆在当前的发展中面临的压力主要表现为馆藏资源建设和服务发展与读者需求之间的矛盾。高职院校只有尽快转变观念,建立适应读者需求,以资源为基础,以服务为主导的可持续机制,才能在知识经济和网络竞争带来的压力中获得长足的发展。     

现代化与三元结构的农业技术创新体系--中国近代农业技术创新与需求初探

本文从现代化的视角提出农业技术创新体系三元结构理论，并用它分析近代中国农业科技发展与社会政治经济变迁之间的关系。重点探讨了近代中国社会政治、经济变迁所引发的农业技术需求对农业技术创新体系形成的影响。     

水产品产品因素对市场需求的影响

影响水产品市场需求的因素有很多,产品因素是最主要的影响因素之一.本文论述了水产品产品因素诸如种类、质量、价格、包装、服务等对水产品市场需求的影响,并提出了如何围绕水产品产品因素扩大水产品市场需求的措施.