多层与高层建筑中选用塔吊施工的问题研究

随着我国经济的快速发展,国家越来越重视多层与高层建筑建造过程中选用塔吊施工的情况。为了进一步提高建筑工程塔吊施工的质量,需要根据实际情况构建完善的安全管理举措,增强工作人员的基本执行力,将工作一步一步细化到位并落实到每一个人,保障施工人员的生命健康安全,确保该项问题得到社会各级的重视。因此,论文针对多层与高层建筑中选用塔吊施工的问题进行简要分析,并提出合理化建议。     

浅谈T3连接线项目环水保管理控制

高速公路建设规模大、建设周期长、资源消耗集中,与社会进步、经济发展和环境条件密切关联,对于环境保护和水土保持既有积极作用,又有消极影响。论文主要结合中川机场T3航站楼连接线建设项目环水保管理方面的一些经验和做法,探讨高速公路建设项目环水保在施工阶段的管理控制要素,提出了环水保标准化管理的建议,供高速公路及其他建设项目的环境保护和水土保持管理提供参考。     

建筑施工成本管理的造价预结算审核

在建筑工程施工的过程中,施工成本管理工作是十分重要的。其中预结算审计和成本控制是影响成本管理工作的重要因素。论文根据一些有关的材料,对工程建设中造价预结算的基本含义以及对企业的影响进行分析,为未来建筑企业发展以及有关的专业研究人员提供参考。     

石油物流网络的建构及其实现途径

随着当前社会与经济的发展,对于石油等能源物质的需求量不断增加,石油在物流运输过程中所产生的成本也在不断提升。为降低我国石油物流运输工作过程中的成本,需要对当前石油物流的整体发展进行研究,并且基于此构建中国石油物流网络系统,从而使石油物流网络的整体运转效率得到提升并且降低成本。     

建筑工程高处坠落事故发生原因及预防措施探讨

在建筑工程的施工过程中,由于现场环境过于复杂,劳动过于密集,很容易发生各种类型的安全事故。建筑工程施工中经常涉及高空作业,所以高空坠落事故的发生几率相对较高。要想保证建筑工程行业的健康发展,就必须加强安全管理,降低高处坠落事故的发生几率。论文重点针对建筑工程高处坠落事故的发生原因进行了详细的分析,并针对性地提出了预防措施,以供参考。     

铁路枢纽工程咽喉区复杂道岔组织施工技术研究

站场咽喉改造需在不影响铁路运营的前提下在封锁点内完成。如何安全、高效、可行地完成施工任务,关键在于制定详细可行的方案,而施工组织是决定方案是否可行的关键。因此,论文结合哈尔滨站咽喉区组合道岔的施工情况,对施工组织设计及施工技术方案进行了论述。     

Mortality,Human Capital and Persistent Inequality

Available evidence suggests high intergenerational correlation of economic status and persistent disparities in health status between the rich and the poor. This paper proposes a mechanism linking the two. We introduce health capital into a two-period overlapping generations model. Private health investment improves the probability of surviving from the first period of life to the next and, along with education, enhances an individual’s labor productivity. Poorer parents are of poor health, unable to invest much in reducing mortality risk and improving their human capital. Consequently, they leave less for their progeny. Despite convex preferences and technologies, initial differences in economic and health status may perpetuate across generations when annuities markets are imperfect.Additional support was provided by the National Science Foundation. Additional support was provided by the National Science Foundation.     

The nature of the steady state in models of optimal growth under uncertainty

Summary. We study a one-sector stochastic optimal growth model with a representative agent. Utility is logarithmic and the production function is of the Cobb-Douglas form with capital exponent . Production is affected by a multiplicative shock taking one of two values with positive probabilities p and 1-p. It is well known that for this economy, optimal paths converge to a unique steady state, which is an invariant distribution. We are concerned with properties of this distribution. By using the theory of Iterated Function Systems, we are able to characterize such a distribution in terms of singularity versus absolute continuity as parameters and p change. We establish mutual singularity of the invariant distributions as p varies between 0 and 1 whenever . More delicate is the case . Singularity with respect to Lebesgue measure also appears for values such that . For and Peres and Solomyak (1998) have shown that the distribution is a.e. absolutely continuous. Characterization of the invariant distribution in the remaining cases is still an open question. The entire analysis is summarized through a bifurcation diagram, drawn in terms of pairs .Received: 9 April 2002, Revised: 29 October 2002, JEL Classification Numbers: C61, O41.Correspondence to: Tapan MitraThis research was partially supported by CNR (Italy) under the "Short-term mobility" program and by M.U.R.S.T. (Italy) National Group on "Nonlinear Dynamics and Stochastic Models in Economics and Finance" . We are indebted to Rabi Bhattacharya for providing us with the reference to Solomyak's (1995) paper. The present version has benefitted from comments by Mukul Majumdar and two anonymous referees.     

Modeling Disinterest and Dislike: A Bounded Bayesian Mixed Logit Model of the UK Market for GM Food

Mixed logit models represent a powerful discrete choice analytical model but require assumptions about the functional form of the parameter distributions. The use of unbounded distributions, such as the normal distribution, may be regarded as unsuitable where theory indicates that all are negatively affected by increases in an attribute, such as price. Bounded distributions such as the triangular and log-normal are unable to model the case where a section of the population is indifferent towards an attribute, while the remainder are negatively disposed toward it. Train and Sonnier’s bounded mixed logit model accommodates these features and is employed in this paper. A censored normal and Johnson’s S_b distribution are used to model preferences in the UK for food attributes, including price and GM technology. Bi-modal distributions are identified regarding GM food: some are unlikely to ever consume it, some are close to indifference and willing to consume at relatively small discounts while the remainder are fairly unresponsive to further price reductions.     

城乡居民收入差距的动态演变:1988～2002年

中国城乡居民收入差距已经引起广泛关注。文章以住户调查数据为基础,利用泰尔指数分解、G.Fields分解、Blinder分解、分位回归分解等多种方法讨论了1988年、1995年和2002年“城乡”因素本身对城乡居民收入差距的贡献。这些分解结果表明我国的城乡差距较显著并在不断扩大;而且城乡差距更不利于农村中的低收入人群。