基于活动方法的瓶颈模型与拥挤收费问题研究

Vickrey提出的基于出行的瓶颈模型以出行作为分析单位,没有考虑出行与活动之间的相互关联.本文对Vickrey的瓶颈模型进行了拓展,提出了基于活动的瓶颈模型来研究通勤者早晨上班出发时间决策问题,模型考虑了通勤者对出行负效用与活动效用之间的权衡.在基于活动的瓶颈模型的基础上,分别研究了常数和线性边际活动效用下瓶颈动态拥挤收费和阶梯收费问题,并与传统的瓶颈模型的解进行比较.结果表明,当活动的边际效用为线性函数时,瓶颈处最优动态收费曲线不再呈分段线性关系,而是分段二次曲线;与基于活动的瓶颈模型相比,传统的基于出行的瓶颈模型将高估瓶颈处的排队延误、阶梯收费水平,以及早高峰的开始和结束时间;基于出行的瓶颈模型和常数边际活动效用下的瓶颈模型导致的最优阶梯收费是最优动态收费最大值的一半,并且刚好消除瓶颈处排队延误的一半;与线性边际活动效用下的瓶颈模型相比较,两者低估了阶梯收费能消除的瓶颈排队,从而低估了阶梯收费的效率.     

超越“范式”：国际问题研究的路径探微

当代国际政治理论的发展演变表现出一种对国际政治现象进行多重视角、多种层次研究的趋势,它给予人们的一个重要启示就是,没有一种能够解释一切的理论。但反过来说,不同的理论针对不同的对象也具有各不相同的解释力。我们必须认识到任何单一的理论都不可能解释国家对外行为的全部复杂性,必须提出一种综合的分析框架,结合现实主义、自由主义和建构主义各自精到的阐述,从历史、经济、政治、文化的视角来进行阐述和分析。     

高中阶段普通教育与职业教育协调发展的对策

随着我国生产力发展水平的提高,高中阶段的教育规模也在不断扩大,但只有合理的教育结构才能与劳动力市场需求相适应。为此,通过对高中阶段普通教育与职业教育的结构分析,在职业教育普通化和普通教育职业化的发展趋势下,提出新时期职业教育与普通教育在价值观念层面上要保持一致,适当发展一定比例的综合高中,构建职、普沟通的立交桥,从而促进职、酱教育的协调发展。     

解读“80后”大学生道德认识矛盾性提高德育效益

为了探索新形势下实施德育的有效途径,提高德育效益,笔者针对“80后”大学生的道德认识进行了问卷抽查。在对调查结果进行综合分析的基础上,认识到：“80后”大学生的道德认识具有矛盾性,并分析了道德认识矛盾性的原因,重点从三个层面提出提高德育效益的途径：第一,社会层面,重构社会高层价值体系;第二,学校层面,要树立全员育人的大德育观念,内容要具有可接受性,方法上要加强情境性教育、体验性教育;第三,大学生要注重自我教育。     

农业院校学生提高实践技能的途径研究

为适应社会就业形势的需要,拓展就业空间,大学生不但要有扎实的理论基础,还必须具有过硬的实践技能,能为社会或相关行业解决生产中的实际问题。提高学生实践技能的途径可通过改进实践教学体系、加强科研能力的训练、注重科技创新能力的培养、实施综合性教学实习、进行社会实践等途径来实现。     

Link-tracing sampling with an initial sequential sample of sites: Estimating the size of a hidden human population

We proposed a modification to the variant of link-tracing sampling suggested by Félix-Medina and Thompson [M.H. Félix-Medina, S.K. Thompson, Combining cluster sampling and link-tracing sampling to estimate the size of hidden populations, Journal of Official Statistics 20 (2004) 19–38] that allows the researcher to have certain control of the final sample size, precision of the estimates or other characteristics of the sample that the researcher is interested in controlling. We achieve this goal by selecting an initial sequential sample of sites instead of an initial simple random sample of sites as those authors suggested. We estimate the population size by means of the maximum likelihood estimators suggested by the above-mentioned authors or by the Bayesian estimators proposed by Félix-Medina and Monjardin [M.H. Félix-Medina, P.E. Monjardin, Combining link-tracing sampling and cluster sampling to estimate the size of hidden populations: A Bayesian-assisted approach, Survey Methodology 32 (2006) 187–195]. Variances are estimated by means of jackknife and bootstrap estimators as well as by the delta estimators proposed in the two above-mentioned papers. Interval estimates of the population size are obtained by means of Wald and bootstrap confidence intervals. The results of an exploratory simulation study indicate good performance of the proposed sampling strategy.     

The state and the development of an information society: Greek policy and experience

The paper looks into the dynamics of information society policy and its implementation in the Greek context. It argues that information society development is a contested process, influenced by pre‐existing state, economy and society relations. Based on this, it looks into the different aspects of the idiosyncratic path which the evolution of the Greek information society has followed, particularly after 2000. Using Bob Jessop's strategic‐relational approach (SRA) to the state as an analytical framework and drawing on a number of in‐depth interviews with relevant political actors, it provides insights into policy implementation by examining: the public management of information technology projects, how such projects were received in bureaucratic structures and practices, as well as the relationship between the state and the information and communication technology (ICT) sector in public procurement processes. The emphasis is on the period 2000–2008, during which a major operational programme on the information society in Greece was put into effect. The paper also touches upon the post‐2008 experience, suggesting that information society developments might include dynamics operating independently and even in contradiction to the state agenda.     

Evaluating social exclusion interventions in university-community partnerships

Most university-community partnerships (UCPs) involve elements of community-level social exclusion interventions. As such, they face substantial challenges in management and evaluation. This paper highlights the central challenges associated with evaluation of UCP and other social exclusion interventions at the community level, and suggests methods to overcome them. The main body of the paper presents a case study based on a four-year action research involving evaluation of a social exclusion intervention initiated and implemented by a UCP in Israel. The case study highlights the challenges faced by the evaluation team, the solutions provided, and the contribution of the evaluation to improvement and accountability.     

Developing social work students’ professional identity: the role of England’s Professional Capabilities Framework

ABSTRACT

Developing professional identity is a key aim of social work education. This paper argues that the Professional Capabilities Framework (PCF) – a holistic, capability approach to student assessment used in England’s social work education programmes – is ideally placed to promote the development of students’ professional identities. The paper discusses two research studies, each of which was stimulated by significant policy changes in England’s social work profession. The author draws out the implications of both studies for supporting social work students to develop their professional identities. It is concluded that the PCF is valued by practice educators as an assessment and teaching tool, while acknowledging that its future is uncertain due to the lack of continuity impacting on England’s social work profession. This paper is equally of relevance for social work educators outside the UK who may be developing and evaluating their assessment approaches and also for those experiencing the impact of rapid policy changes in their own countries.     

Computational approach test for inference about several correlation coefficients: Equality and common

In this article, we consider inference about the correlation coefficients of several bivariate normal distributions. We first propose computational approach tests for testing the equality of the correlation coefficients. In fact, these approaches are parametric bootstrap tests, and simulation studies show that they perform very satisfactory, and the actual sizes of these tests are better than other existing approaches. We also present a computational approach test and a parametric bootstrap confidence interval for inference about the parameter of common correlation coefficient. At the end, all the approaches are illustrated using two real examples.