数控机床进给伺服系统的典型故障及诊断

数控机床是典型机电一体化产品,故障出现的种类和原因很多,其中进给伺服系统故障所占比重较大,文中主要以典型的进给伺服系统故障为例,总结、分析引起伺服系统故障的原因,并提出解决的思路和办法。     

地源热泵系统的应用研究

为了减少一次性能源的使用和对环境的污染,本文以陕西安康市某综合建筑为例,通过对比地源热泵系统和常规空调系统的初投资和运行费用,论证了地源热泵系统的经济性。     

基于“四位一体”的职业教育双师型教师队伍建设

本文阐述了职业教育院校基于学校、政府、行业和企业四位一体的环境下,建设双师型教师队伍的目标、思路、措施和体制机制创新。     

Information systems and technology sourcing strategies of e-Retailers for value chain enablement

In the e-Retail industry, a well-designed IT infrastructure is essential in creating a tightly integrated value chain and delivering high quality service. With intense competition for market share and profits, information systems and technology (IST) sourcing decisions are becoming increasingly important to e-Retail firms to support continued growth and market responsiveness. Drawing on the contingency theory, we examine organizational and environmental factors that influence an e-Retailer's IST sourcing strategy of make versus buy in enabling its value chain activities, and we also look at firm-level performance impacts of IST sourcing decisions that involve bundling across value chain activities. We test the proposed model and hypotheses using a panel data set of 307 firms over the period of 2006–2010. The results show that firms that make transformative IT investments tend to source a smaller portion of IST for their e-Retail value chain activities than firms that pursue automate or informate as their strategic role for IT investment. Capabilities are positively associated with IST sourcing. Firms experienced in e-Retail are more likely to build rather than buy their IST. In addition, we find mimicking behavior for IST sourcing among firms in the same merchandizer category. We find that IT strategic role is strongly associated with growth metric, whereas sourcing decisions predominantly impact operational performance measures. There is partial evidence that alignment between IT strategic role and IST sourcing decisions results in better performance effects. Moreover, complementary IST sourcing of synergistic marketing and sales activities positively impacts Web sales and conversion rate, but the sourcing combination of logistics, operations, and sales activities is associated with lower Web sales and conversion rate.     

Examining the link between skill shortages,training composition and productivity levels in the construction industry: evidence from Northern Ireland1

One of the key questions in international research addresses the tensions arising from international co-ordination and local adaptation of multinational companies' (MNCs) policies and practices. The German business system encourages MNCs to have a long-term, high-investment orientation, to practise intensive management-labour cooperation and to pursue developmental human resource management (HRM). This study analyses six major German MNCs operating in both Britain and Spain and outlines their reasons for the international co-ordination of HRM. It addresses the issue of central control versus local adaptation by looking at the transfer of German HR policies and practices. The cases show that the MNCs were able to preserve substantial ‘German-ness’ abroad. However, the results of the transfer of German HRM were not always positive due to a variety of endogenous and exogenous causes. Barriers to transfer from institutionally strong to weak environments are discussed and possible internal HR approaches are suggested to counterbalance the national business system effect. Their success will depend on head office-foreign affiliate relations shaped by factors such as cross-border communication, trust and power distribution.     

具有折扣因子的供应链库存控制模式研究

针对具有折扣因子的供应链环境,建立了供应链库存控制模式的系统动力学仿真模型;模型经过参数优化,比较了三种供应链库存控制模式(看板、CONWIP及混合控制模式)的运行效果,并对折扣因子进行了灵敏度分析。通过模型研究,得出三种模式在具有折扣因子的供应链环境下的优缺点,并指出混合控制模式是该环境下的较优控制策略。     

Employer Penalties for Failure to Provide Individual Employee Notification Under the Family and Medical Leave Act: “Clarifications” Following Ragsdale v. Wolverine Worldwide, Inc.

This article examines the Supreme Court's ruling in Ragsdale v. Wolverine Worldwide, Inc. (2002) and considers its implications for employer and employee rights and responsibilities relative to implementing the FMLA policies. We provide an overview of the pre-decision regulatory environment including the general leave provisions of the FMLA and DOL's regulations requiring employer notification of leave designated as FMLA leave. We also identify those provisions that the decision did not alter and provide a broader consideration of the issues and implication of this decision for employers and employees.     

Stochastic leader–follower DEA models for two-stage systems

Data envelopment analysis (DEA) is a non-parametric approach for measuring the relative efficiencies of peer decision making units (DMUs). In recent years, it has been widely used to evaluate two-stage systems under different organization mechanisms. This study modifies the conventional leader–follower DEA models for two-stage systems by considering the uncertainty of data. The dual deterministic linear models are first constructed from the stochastic CCR models under the assumption that all components of inputs, outputs, and intermediate products are related only with some basic stochastic factors, which follow continuous and symmetric distributions with nonnegative compact supports. The stochastic leader–follower DEA models are then developed for measuring the efficiencies of the two stages. The stochastic efficiency of the whole system can be uniquely decomposed into the product of the efficiencies of the two stages. Relationships between stochastic efficiencies from stochastic CCR and stochastic leader–follower DEA models are also discussed. An example of the commercial banks in China is considered using the proposed models under different risk levels.     

转变方式完善体制 加快现代市场发展——论学习中共十七大报告

党的十七大在我党历史上第一次郑重地、鲜明地、完整地提出了高举中国特色社会主义伟大旗帜,并将其载入党章,强调中国特色社会主义伟大旗帜,是当代中国发展进步的旗帜,是全党全国各族人民团结奋斗的旗帜。文章通过学习中共十七大报告,从广西农垦的实际情况出发,论述了当前转变方式完善体制,加快现代市场发展的方向。     

The relationship between employee performance management and civil servants’ turnover intentions: a test of the mediating roles of system satisfaction and affective commitment

In search of maximizing efficiency, public organizations found solace in the adoption of employee performance management (EPM) systems. While research supports that managing employees’ performance has favourable outcomes, it is still unclear why and under which conditions. Moreover, EPM systems might even create additional pressures and therefore increase turnover intentions and undermine public organization’s quest to maximize efficiency. We argue that when EPM systems are carried out consistently (i.e. internal consistency) and when they link civil servants’ individual goals to the organization’s strategic goals (i.e. vertical alignment), civil servants will be less likely to leave the organization. Hierarchical linear regression analysis shows that internal consistency relates to increased satisfaction with the EPM system and affective commitment to the organization. Vertical alignment relates to lower levels of turnover intentions. This relationship was mediated by EPM system satisfaction and affective commitment. These findings that contribute to our understanding of EPM systems can lead to favourable outcomes.