Style and performance of international socially responsible funds in Europe

This paper analyses the performance and investment styles of internationally oriented Socially Responsible Investment (SRI) funds, domiciled in eight European markets, in comparison with characteristics-matched conventional funds. To the best of our knowledge, this is the first multi-country study, focused on international SRI funds (investing in Global and in European equities), to combine the matched-pairs approach with the use of robust conditional multi-factor performance evaluation models, which allow for both time-varying alphas and betas and also control for home biases and spurious regression biases.In general, the results show that differences in the performance of international SRI funds and their conventional peers are not statistically significant. Regarding investment styles, SRI and conventional funds exhibit similar factor exposures in most cases. In addition, conventional benchmarks present a higher explaining power of SRI fund returns than SRI benchmarks. Our results also show significant differences in the investment styles of SRI funds according to whether they use “best-in-class” screening strategies or not. When compared to SRI funds that employ simple negative and/or positive screens, SRI “best-in-class” funds present significantly lower exposures to small caps and momentum strategies and significantly higher exposures to local stocks.     

Dynamic relationships between tourist arrivals,immigrants, and crimes in the United States

This paper investigates the dynamic relationships between tourist arrivals, immigrants, and crimes in the United States (U.S.) from 1984 to 2013. Our findings affirm the social structural perspectives (i.e. Merton's Strain theory and Social Disorganization theory), which contain a popular perception about the immigration and crime that they both go hand in hand. Results of bivariate analysis revealed that immigrants admitted by Europe, Mexico, and North America to U.S. are positively correlated with key crimes. Tourist arrivals positively influence crime rate only in short-run, which affirms the Opportunity Structural perspectives (i.e. Routine Activity and Hot Spot theories). Furthermore, immigrants positively influence tourist arrivals, which supports the Visiting Friends and Relatives (VFR) empirical perspective. Therefore, concerned authorities can focus on environmental design initiative in concerned areas (i.e. immigrants' communities and tourists' cities). Furthermore, future research and implications are discussed.     

Do contractual practices affect technical efficiency? Evidence from public transport operators in China

This paper presents a discussion on the causal effect of contractual practices on the technical efficiency of Chinese public transport operators. To test this proposition, an original panel data set covering 47 operators over the period 2008–2013 is used, we firstly estimate the technical efficiency based on the stochastic frontier approach in a time-varying form of the trans-log production function, and then consider a propensity score matching approach to assess the causal effect between them. The econometric results corroborate this proposition that gross cost contracts offer more incentives to technical efficiency than net cost contracts and management contracts.     

Measuring the Real and Financial Connectedness of Selected African Economies with the Global Economy

We examine the real and financial connectedness of selected African economies with the global economy using a network approach. We find that the connectedness of African economies with the global economy is quite sizable, with the global financial crisis increasing the connectedness measures above their pre‐crisis levels. The results show that U.S., EU and Canada dominate Africa's equity markets, while China, India and Japan dominate Africa's real activities. Our results suggest that African economies are predominantly small open economies, deeply interconnected but systemically unimportant and vulnerable to headwinds emanating from the dominant economies in the overall global economy.     

语言测试标准规范与测试质量管理——以欧美专业伦理规范及其践行为例

语言测试标准规范制定的目的在于规范测试行为,提升考试质量。测试标准规范是否有用,需要在语言测试效度评估中得到有效实践。但是目前欧美一些重要测试组织的核心专业伦理及技术规范的践行现状相差很大,有的规范几乎流于形式,有的则得到了有效实践,提升了考试及测试质量管理的水准。对欧美现行主要语言测试标准规范及其践行现状的研究将有助于我们甄别、借鉴。为语言测试质量保证提供专业指导和基础的标准规范,不仅不可缺少,还应当被有效实践。     

OPTIMAL CONSUMPTION AND PORTFOLIO SELECTION WITH INCOMPLETE MARKETS AND UPPER AND LOWER BOUND CONSTRAINTS

We study an optimal consumption and portfolio selection problem for an investor by a martingale approach. We assume that time is a discrete and finite horizon, the sample space is finite and the number of securities is smaller than that of the possible securities price vector transitions. the investor is prohibited from investing stocks more (less, respectively) than given upper (lower) bounds at any time, and he maximizes an expected time additive utility function for the consumption process. First we give a set of budget feasibility conditions so that a consumption process is attainable by an admissible portfolio process. Also we state the existence of the unique primal optimal solutions. Next we formulate a dual control problem and establish the duality between primal and dual control problems. Also we show the existence of dual optimal solutions. Finally we consider the computational aspect of dual approach through a simple numerical example.     

LATTICE BOLTZMANN METHOD WITH DOUBLE MESHES

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｒｅｃｅｎｔ ｙｅａｒｓ ,ｔｈｅｏｒｙａｎｄａｐｐｌｉｃａｔｉｏｎｓｏｆＬａｔｔｉｃｅＢｏｌｔｚｍａｎｎｍｅｔｈｏｄ (ＬＢＭ )ｈａｖｅｍａｄｅｒａｐｉｄ ｐｒｏｇｒｅｓｓ ,ｍａｋｉｎｇＬＢＭｃｏｍｐｅｔｉｔｉｖｅｔｏｔｈｅｃｏｎｖｅｎｔｉｏｎａｌａｐｐｒｏａｃｈｅｓｉｎＣｏｍｐｕｔａｔｉｏｎａｌＦｌｕｉｄＤｙｎａｍｉｃｓ (ＣＦＤ )ａｎｄａｎａｌｔｅｒｎａｔｉｖｅｗａｙｔｏｓｉｍｕ ｌａｔｅｔｈｅｆｌｕｉｄｆｌｅｌｄ[1] .ＴｈｅｋｅｙｉｄｅａｂｅｈｉｎｄＬＢＭｉｓｔｈ…     

Learning competitive pricing strategies by multi-agent reinforcement learning

In electronic marketplaces automated and dynamic pricing is becoming increasingly popular. Agents that perform this task can improve themselves by learning from past observations, possibly using reinforcement learning techniques. Co-learning of several adaptive agents against each other may lead to unforeseen results and increasingly dynamic behavior of the market. In this article we shed some light on price developments arising from a simple price adaptation strategy. Furthermore, we examine several adaptive pricing strategies and their learning behavior in a co-learning scenario with different levels of competition. Q-learning manages to learn best-reply strategies well, but is expensive to train.     

立井井筒涌水量预测的优化数值法

本文将煤矿立井井筒涌水量的预测视为求解地下水运动问题中的反演问题，根据求解逆问题的思想，建立预测井筒涌水量的优化模型，结合有限单元法求解地下水的运动模型，通过一维搜索的方对井筒涌水量作出预测。     

汉译英常见错误辨析

文章前面三个部分研究了英训学习过程中错误的意义，错误的识别以及分类的理论，根据这个理论，第四部分例举了非英语专业大学生的汉译英错误，分析了这些错误产生的原因是由于汉英之间的巨大差异及翻译中汉语的负迁移。第五部分探讨了针对这些问题的教学方法。