Confidence intervals,significance values,maximum likelihood estimates,etc. sharpened into Occam’s razors

Abstract

Confidence sets, p values, maximum likelihood estimates, and other results of non-Bayesian statistical methods may be adjusted to favor sampling distributions that are simple compared to others in the parametric family. The adjustments are derived from a prior likelihood function previously used to adjust posterior distributions.     

基于股价预测的泛证券投资组合策略

本文基于期望效用最大化和L₁-中位数估计研究了在线投资组合选择问题。与EG（Exponential Gradient）策略仅利用单期价格信息估计价格趋势不同，本文将利用多期价格信息估计价格趋势，以提高在线策略的性能。首先，基于多期价格数据，利用L₁-中位数估计得到预期价格趋势。然后，通过期望效用最大化，提出一个新的具有线型时间复杂度的在线策略，EGLM（Exponential Gradient via L₁-Median）。并通过相对熵函数定义资产权重向量的距离，进而证明了EGLM策略具有泛证券投资组合性质。最后，利用国内外6个证券市场的历史数据进行实证分析，结果表明相较于UP（Universal Portfolio）策略和EG策略，EGLM策略有更好的竞争性能。     

对目前我国私营企业主阶层的思考

如何促进私营经济持续稳定健康发展、引导私营企业主阶层成为坚定的社会主义事业的建设者是当前乃至今后一个较长时期内我国社会政治生活中的一个重大课题。为此一要充分认识私营经济和私营企业主阶层存在的长期性 ,采取切实有效的措施谋划私营经济的新发展 ;二要充分认识私营企业主阶层的特殊性 ,正确把握评价私营企业主政治上进步与否的判断标准 ;三要充分认识私营企业主阶层的复杂性 ,坚持德治与法治相结合 ,使其成为坚定的社会主义事业的建设者。     

插入排序法研究(1)

讨论了两种二路插入排序的方法，给出了算法思想，分析了这些方法的时间复杂度，其平均时间复杂度比直接插入排序法降低了1/2-1/2，说明这些排序方法比直接插入排序法具有较高的排序效率。     

On the difficulty of making social choices

The difficulty of making social choices seems to take on two forms: one that is related to both preferences and the method used in aggregating them and one which is related to the preferences only. In the former type the difficulty has to do with the discrepancies of outcomes resulting from various preference aggregation methods and the computation of winners in elections. Some approaches and results which take their motivation from the computability theory are discussed. The latter institution-free type of difficulty pertains to solution theory of the voting games. We discuss the relationships between various solution concepts, e.g. uncovered set, Banks set, Copeland winners. Finally rough sets are utilized in an effort to measure the difficulty of making social choices.     

Cybernetic Risk Analysis

The Pearl Harbor case study reveals that risk analysis failure may be caused by any of a number of factors. However, the most important variables are system load, gain, lead time, and lag time. The dynamics of such cybernetic systems analysis constitute an important aspect in this regard. Four different risk management strategies, or organization designs, have been proposed in this paper. Each has a unique combination of the imputed variables and each has a unique cause of surprise, risk analysis failure, and crisis.     

Complexity: Some Remarks about a Classical Aesthetic Concept

The connection between autonomous art and complexity has been extensively and deeply studied in literary theories in the 20th century. The rise of aesthetic autonomy implies the complexity of literary work as the concept of a sealed container arises from the relationship between the parts that make it up. In this model, the interpretation subject works to directly face literary texts. Instead of pursuing the author’s intention, it aims to reproduce the richness and subtlety of the aesthetic state, and consider the richness and subtlety revealed in the maximum amount of text details in literary works, even if procedurally deviating from the way of mainstream understanding. There is increasing skepticism about the consequences of the autonomous aesthetics, which has been coerced by the development of contemporary capitalism, and it is necessary to develop new forms of aesthetics to reflect the changing social situation.     

Schematising hospitality: Ai WeiWei’s activist artwork as a form of dark travel

The article provides a holistic appraisal of activist-artist Ai WeiWei’s work. It argues that, despite its topical innovations and evolution, it continues to be informed by narratives of ‘hospitality’ as an experiential form of engagement with variations of otherness (father, migrant, tourist and refugee). Dividing Ai’s artwork into two overlapping phases of development (national and international/global), it considers the artist’s construction of a cosmopolitan identity with uses of ‘technology’ as embodied and communal property. As Ai’s work on the refugee crisis on Lesbos attests, his (dark) artistic cosmopolitan symbolisations use geo-political imaginaries of justice and hospitality in subsequent projects.     

Contingent constellations: African urban complexity seen through the workings of a Ghanaian bus station

In this article, I explore the intricate relationship between regulation and contingency in processes of urban economic organisation by focusing on the workings of a central bus station in Accra, Ghana. After introducing the position of the station in Ghana’s urban economy and transport infrastructure, I set out its internal regulative arrangements in relation to larger socio-economic and political constellations the practices of the station workers are contingent upon. Next, I turn the analysis around and describe the ways in which people accommodate themselves within, exploit and thereby co-produce emergent contingencies. The focus on the station, I suggest, offers a window into the complex constituents of niche economic practices that prevail in many spheres of African cities and allows a nuanced reflection on the incongruous and undetermined dynamics of everyday urban ‘becomings.’     

复杂性科学视角下企业成长研究梳理与启示

作为研究和处理复杂系统和行为的工具，复杂性科学为企业成长研究提供了新的起点。从复杂性科学的背景出发，总结了目前企业成长研究的基本共识、内容体系，并为企业管理与决策实践提供指导。