用分组垫片法解装配尺寸链的研究

本文系统研究了用分组垫片法解装配尺寸链时的计算方法。提出了改进和完善用分组垫片法解装配尺寸链的四个问题:组成环经济公差的标准化;理论计算垫片分组数的取整;每组垫片的分配数量和装配尺寸链的概率计算法。并给出了相应的分析和计算方法,使其理论能够更准确、更方便地运用于实际设计过程中。     

Gross national accumulation

Low birth rates, longevity, family disintegration, and other factors have reduced the size of the average household. At the same time household size is shrinking, new housing offers twice the floor space per occupant of old housing. Small households are inefficient users of space, utilities, furniture, and equipment. As these factors converge, the result is over consumption of durables and vast stockpiles of possessions just awaiting disposal when the baby boom generation passes on. The rightful heirs to these possessions are themselves accumulators, and will most likely have little use for what is left to them. What does the future hold for consumption, savings, and demand for housing? Booming flea markets, bigger homes as warehouses, a decline in consumption, or an epidemic of display and collection? Public policies have limited leverage on private behavior.     

我国开放式基金规模确定模型初探

通过对美国共同基金关于基金规模的数学模型分析,我们发现基金规模与基金经理人能力和流动性赎回密不可分。从美国的有关模型分析与优秀经验来谈我国为确定基金规模所采取的措施:首先讨论了保证基金管理人发挥其能力的一些政策性建议,其次讨论了减少流动性赎回所采取的措施。     

Unobserved firm heterogeneity and the size-exports nexus: Evidence from German panel data

This paper starts from the stylized fact that firm size and exporting tends to be positively related. Using large sets of establishment panel data for three different industries from official statistics, evidence is presented that the familiar picture of an export/sales ratio that increases (at a decreasing rate) with firm size vanishes if unobserved firm heterogeneity is controlled for in a fixed-effects fractional logit regression model. This finding is well in line with the fact that many small firms are “hidden export champions.” JEL no. F10, D21, L60     

中国商业银行信息技术资本的边际生产率及最优规模

基于12家商业银行1997～2005年间的数据，对商业银行信息技术资本的边际生产率和最优投入规模的实证研究结果表明，我国商业银行信息技术资本的边际生产率是正的，且其大小受银行规模和时间的影响；四大商业银行信息技术资本的边际生产率小于中小规模商业银行；银行整体的信息技术资本边际生产率随时间呈现不断增长的趋势；四大商业银行信息技术投资已经超过了最优规模，而中小商业银行尚未达到最优规模。四大商业银行应该着重提高信息技术资本的利用率，完善互补机制，而中小商业银行应进一步加大信息技术的投资量。研究结果证明，当前“信息技术生产率悖论”在我国商业银行中并不成立。     

中国金融业资产的规模与效率

通过在金融资产结构与经济增长模型中引入能够综合反映制度变迁的制度变量,证明国家制度变迁对一国金融资产结构与经济增长会起到促进或制约的作用.当制度供给与金融资产结构和经济增长对制度的需求达到均衡时,国家制度安排会优化金融资产结构、促进经济增长,否则便会出现规模与效率的"反比"现象,从而回答了我国金融资产规模与效率之间为什么出现悖论的问题.我国应积极发展非银行金融机构,实现金融体系多元化,对内开放,满足我国经济对多层次、多样化金融的需求,完善金融市场准入制度,优化市场参与主体结构,促进股票市场和银行协调发展.     

Does size matter? Corporate social responsibility and firm performance in the restaurant industry

Despite an increasing number of hospitality studies on the link between corporate social responsibility (CSR) and corporate financial performance (CFP), the literature has predominantly focused on the CSR–CFP relation without considering moderating factors. Consequently, the current study introduces firm size as a potential moderator on the CSR–CFP relationship. Performing a two-way fixed-effects model by firm and year with Newey-West standard errors, this study finds that firm size moderates the effect of positive CSR on CFP while it does not moderate the effect of negative CSR on CFP in the U.S. restaurant context.     

Firm Microstructure and Aggregate Productivity

Models of firm microstructure are becoming now a standard building block in macroeconomics, trade, and development. This literature builds on the recognition that firm heterogeneity and the allocation of resources across firms plays a key role in determining aggregate productivity and the gains from trade. Barriers to the efficient allocation of resources across firms have been recently recognized to play a key role in economic development. This paper focuses on this methodological contribution, the link between firm microstructure and economic aggregates.     

Collaboration,motivation, and the size of organizations

We present an analytical model of an organization that offers operational drivers of limits on team size. The model trades off benefits from collaborative problem solving against the disadvantages of diminishing motivation when groups get large. Collaboration is represented as parallel employee activity combined with frequent sharing of partial information, with a resulting superlinear performance increase over team size. Motivation is modeled by team members periodically setting an effort level either to contribute to the best of their ability or to “cruise”; at the minimum level not recognizable as shirking. Each individual decision is limited by bounded rationality based on team rewards, the time horizon of team interaction, and individual expectations about colleagues’ behavior. The decision collapses to a simple “barrier rule”;. Work hard when a certain “barrier percentage”; of team members work hard, and otherwise shirk. The influence of team size on this barrier percentage depends on the extent of benefits from collaboration: As long as performance increases quadratically with team size, the increased benefits resulting from collaboration exactly balance the temptation to shirk, with the barrier percentage approaching a fixed limit for large team sizes. As soon as the performance increase slows to anything less than quadratic, shirking eventually sets in and limits the possible size of the team. This implies that cooperation is sustainable in large organizational units, provided the problem‐solving processes used are powerful enough to ensure sufficient performance increases. Thus, effective problem‐solving methods are of double value, improving direct productivity and mitigating the social dilemma from team production. A manager should enlarge his or her organization up to the minimum of the limit set by the cooperation barrier and the exogenous performance limit.     

对《公差原则》（GB／T4249—1996、GB／T16671—1996）的探讨

详尽阐述尺寸要求，形位要求和相关要求都是独立的要求的观点，对国标（公差原则）中有关定义及条文进行探析，提出定义及条文修改的建议。