RSS技术的应用和发展趋势探讨

RSS是以XML为基础,用于为内容整合客户端提供选择性的、汇总过的Web内容的技术规范。由于RSS具有简单、规范、通用、容易自动生成等特点,因此越来越多的网站也采用这种方式来发布最新信息。本论文先阐述RSS及其相关技术,接着提出RSS阅读器的一个具体实现,最后对RSS的发展趋势进行深一步的探讨。     

Social learning with private and common values

Summary. We consider an environment where individuals sequentially choose among several actions. The payoff to an individual depends on her action choice, the state of the world, and an idiosyncratic, privately observed preference shock. Under weak conditions, as the number of individuals increases, the sequence of choices always reveals the state of the world. This contrasts with the familiar result for pure common-value environments where the state is never learned, resulting in herds or informational cascades. The medium run dynamics to convergence can be very complex and non-monotone: posterior beliefs may be concentrated on a wrong state for a long time, shifting suddenly to the correct state.Received: 6 January 2005, Revised: 5 May 2005, JEL Classification Numbers: C72, D82.Jacob K. Goeree: Correspondence toFinancial support from the National Science Foundation NSF (SBR-0098400 and SES-0079301) and the Alfred P. Sloan Foundation is gratefully acknowledged. We thank Richard McKelvey posthumously for insights and conjectures about information aggregation that helped shape our thinking about the problem. We also acknowledge helpful comments from Kim Border, Tilman Börgers, Bogachen Celen, Luis Corchon, Matthew Jackson and seminar participants at University College London, the University of Arizona, Universitat Autonoma de Barcelona, the California Institute of Technology, the 2003 annual meeting of ESA in Pittsburgh, the 2003 Malaga Workshop on Social Choice and Welfare Economics, the 2003 SAET meetings in Rhodos, and the 2003 ESSET meetings in Gerzensee.     

Classical meets modern in the IDEA protocol for structured expert judgement

Expert judgement is pervasive in all forms of risk analysis, yet the development of tools to deal with such judgements in a repeatable and transparent fashion is relatively recent. This work outlines new findings related to an approach to expert elicitation termed the IDEA protocol. IDEA combines psychologically robust interactions among experts with mathematical aggregation of individual estimates. In particular, this research explores whether communication among experts adversely effects the reliability of group estimates. Using data from estimates of the outcomes of geopolitical events, we find that loss of independence is relatively modest and it is compensated by improvements in group accuracy.     

哈尔滨产业集聚化存在的问题及对策研究

产业集聚以其无可比拟的竞争优势,成为振兴哈尔滨老工业基地首要的战略模式选择。哈尔滨要实现老工业基地振兴的目标,不仅需要国家政策的支持,更需要依靠市场机制,利用本地优势产业的基础和资源禀赋,通过优势产业的集群规模效应,提高城市核心竞争力,促进全市产业结构的调整及产业集聚化的发展,实现振兴老工业基地的目标。     

国际金融中心发展的新趋势及其对上海的启示

伦敦、纽约等国际金融中心金融集聚和扩散的动态过程,反映了金融中心的发展趋势。本文从拥塞效应、金融安全、追随客户、地区竞争以及通讯技术的迅速发展等方面解释了金融扩散的原因。针对上海陆家嘴金融贸易区金融集聚和扩散的现状,结合静安寺、淮海路商圈总部经济和金融机构集聚度较高的状况,提出了上海建设国际金融中心规划布局中“1＋3＋1”,即“一主三副”和一个灾备中心的构想。     

Sequential voting with abstention

Dekel and Piccione [2000. Sequential voting procedures in symmetric binary elections. J. Polit. Economy 108, 34–55] have proven that information cascades do not necessarily affect the properties of information aggregation in sequential elections: under standard conditions, any symmetric equilibrium of a simultaneous voting mechanism is also an equilibrium of the correspondent sequential mechanism. We show that when voters can abstain, these results are sensitive to the introduction of an arbitrarily small cost of voting: the set of equilibria in the two mechanisms are generally disjoint; and the informative properties of the equilibrium sets can be ranked. If an appropriate q-rule is chosen, when the cost of voting is small the unique symmetric equilibrium of the simultaneous voting mechanism dominates all equilibria of the sequential mechanism.     

通过加总推出的总供给曲线

总供给曲线的推导是宏观经济学中的最重要内容之一。在大多数宏观经济模型中 ,在推导总供给曲线时 ,加总问题 (aggregationproblem)往往被忽略。一般认为 ,总供给曲线是各企业供给曲线的简单算术和或是一个代表性企业供给曲线的简单放大。但是 ,在现实中 ,各个企业是不同的。只有在非常严格的条件下 ,总供给曲线与企业供给曲线在性质上才是等价的。考虑到中国经济的制度性特点并在解决加总的一系列技术问题的基础上 ,本文推导出了在企业劳动生产率服从均匀分布情况下的总供给曲线。通过这种方法推出的总供给曲线具有许多传统总供给曲线所不具有的新性质。笔者希望本文能为进一步研究处于微观经济和宏观经济之间的往往被忽视的一块重要领域 (“中观经济领域”)做出贡献。     

聚集抑或扩散——城市规模影响城乡收入差距的理论机制及实证分析

区域中心城市的规模变动引起聚集效应和扩散效应强度的变化,进而影响区域内城镇、农村居民收入水平及城乡收入差距。利用286个地级以上城市2008年的截面数据和2003—2008年面板数据的实证分析显示:总体上中心城市规模越大,区域城乡收入差距越小,城乡收入差距随城市规模变动呈现出U型特征;中心城市的分散型结构有利于缩小区域城乡收入差距,城市经济发展水平越高,城乡收入差距越小;不同规模等级的城市规模对城乡收入差距的影响效应存在较大差异。这些结论对于推动城市可持续发展、统筹城乡发展具有启示意义。     

Aggregation of Directional Distance Functions and Industrial Efficiency

Three main objectives are pursued in this paper. First, we intend to analyze the aggregation problem of directional distance functions from a constructive viewpoint. We provide necessary and sufficient conditions concerning the structural properties of the production technology and of the nature of groups of firms. Indeed, exact additive aggregation holds for a linear technology and for a direction solely defined in the output space. Second, since these conditions are somewhat restrictive, we are interested in providing a measure for the aggregation bias through the relationship between industrial and structural technical efficiency. Finally, we show that this aggregation bias is a lower bound for industrial allocative efficiency.     

Disaggregating and reaggregating work: Workers,management and the struggle over creating coherency and purpose in a context of work degradation

The article argues that whilst there is a growing sense of degradation and worsening conditions (disaggregation) of work in the cleaning sector in general, there are some important contradictions which require complex organisational responses. In the main, there is a growing sense of isolation in this work, yet also a growing perception of autonomy and workers having to use discretion in new and challenging ways. This article focuses on these issues and management responses to reaggregate the nature of such work, creating new forms of identity and activities intended to enhance (or address) the levels of stability and sustainability at work as well as in operational processes. This management conundrum means that they need to deal with a range of job‐related, skill‐oriented worker learning and also representation issues. These responses bring to the fore the contested nature of such forms of work and how they are changing.