严寒地区高速铁路混凝土基床聚氨酯保温特性试验研究

基于严寒区京沈客专朝阳试验段路基基床的温度监测资料分析,研究不同厚度聚氨酯保温板对高速铁路路基混凝土基床温度变化特性影响.测试结果表明:①铺设聚氨酯保温板能够有效阻断严寒区环境与路基基床间的热量传递,保温效果与板厚相关;②地温大多数时间呈阳高阴低现象,同时阴、阳坡路基温差波动幅度随埋深逐渐减小;③基床表层阴、阳面各测点的温度变化起始时间一致,而阴面的冻结时间比阳面晚一个月.由此表明,保温板能够有效降低环境与混凝土道床之间的热交换,但是对路基阴、阳坡的影响存在差异.建议在严寒地区高速铁路路基阳、阴坡可以采取不同厚度的聚氨酯保温板,减小阴阳坡地温差异,保持季冻土路基温度变化稳定.     

20kV及以下配电网工程造价的确定与有效控制方法分析

随着我国电网逐渐向智能电网迈进,信息技术在电能传输、转换、分配、调度等方面的应用,使电力企业可以进行结构调整,提高电力系统管理水平。据统计,2011年,我国电力信息化投资达220亿元,2012-2015年,电力工程建设稳步推进。为了促进电力企业全面开展项目成本核算和有效控制,提高电力工程项目的效益,确定了典型方案设计模块,通过定额规则库与典型方案设计相匹配的方法,解决了安装过程中定额第一版遗留的一些问题,并通过设计选型等措施加强了成本控制。     

改进后的PERT方法在进度风险分析中的应用

风险分析是进度控制中的重要内容。针对经典PERT网络的假设和计算过程,分析出它存在的三方面缺陷。并提出解决问题的三种具体措施,从概率论与数理统计的角度,对关键线路和关键工作进行了重新定义和确定的方法。     

Why managers divest—Evidence from New Zealand's largest companies

Chief Executives from New Zealand's largest companies were surveyed to distinguish divesting and nondivesting companies, and to identify the relative importance of the factors and motives which led to the divestment of 208 business units in the period 1985 through 1990. The divesting companies were considerably larger and faster growing than nondivestors. The typical divestment was motivated by the need to convert unattractive assets into liquid form which could then be held to strengthen the balance sheet, or reinvested in either the core business or new areas.     

基于模糊综合评价的职业经理人力资本价值评估模型

文章在分析我国职业经理人力资本价值评估研究现状的基础上,以职业经理激励约束为导向,建立了职业经理综合素质测评体系,构建了职业经理人力资本价值评估模型,最后结合实例验证了模型的有效性。     

旅行社的旅游线路优化设置问题探讨

尽管在旅游线路的设计过程中需要解决的问题很多,但从优化的角度而言,如何设计出一条能实现出发地与目的地间的最短路径目标,便是其中的最为关键性的一个问题。由于不同的交通方式的不同组合能对应着不同的路程、时间与成本问题,因而,如何通过有效的选择来形成最佳的旅游线路也就有了相当的必要性。此外,在旅游线路设计与安排过程中,旅行社除了要合理安排和规划旅游线路的长度以力求不走回头路、不走冤枉路和形成有效的闭合回路外,还需充分考虑到其中的线路在时间安排上的合理问题;否则,再好的线路安排也会失去其内在的价值与影响力。     

Learning across the life cycle: Experimentation and performance among the hollywood studio heads

Guided by notions from the literature on organizational learning, this paper investigates how product line experimentation and organizational performance change across the careers of top managers. Its subjects are the studio heads who ran all the major Hollywood film studios from 1936 to 1965. The study found first, that product line experimentation declines over the course of executive tenures; second, that there is an inverse U‐shaped relationship between top executive tenure and an organization's financial performance; and third, that product line experimentation is more likely to benefit financial performance late in top executives' tenures. These findings are consistent with a three‐stage ‘executive life cycle’. During the early years of their tenures, top managers experiment intensively with their product lines to learn about their business; later on their accumulated knowledge allows them to reduce experimentation and increase performance; finally, in their last years, executives reduce experimentation still further, and performance declines. Copyright © 2001 John Wiley & Sons, Ltd.     

Consistency of UK Pension Fund Investment Performance

Transition matrix techniques are used to relate the past and present performance of pension fund portfolios. In particular, funds are ranked to study the tendency of portfolios to remain in the same quartile of the ranking as they were in the previous period. For raw returns, funds in both of the top quartiles are found to be more likely to remain in the same quartile than would be expected by chance. This result can be taken as limited evidence for the consistency of performance. Similar systemic effects are observed on a risk-adjusted basis. There appears to be clear evidence that some fund managers can offer a degree of consistent good performance.     

Effects of demographic,experiential, and attitudinal factors on occupational sex stereotypes

The purpose of this study was to (a) compare the occupational sex stereotypes of 366 college students with those reported by Shinar in 1975, and (b) examine the relationships between demographic, experiential, and attitudinal variables and these occupational sex stereotypes. The results indicated a significant difference in occupational ratings from Shinar's study, with females' perceptions shifting more than males' perceptions. In addition, subjects' gender, tenure with female managers, and attitudes toward women as managers, were shown to be significant predictors of occuptational ratings. The implications of these findings for both employees and managers are then discussed.     

经济生产量模型对库存的控制

在分析需求变化的基础上修改和完善了经济批量模型,进一步研究了单项物品和多项物品的最小经济生产批量以及年最小总成本,改进了经济生产量模型。