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。     

L2句子加工心理机制的ERPs研究及问题思考

国内外对L2句子加工的研究存在着较大区别。国外偏重于探讨句子加工的心理机制本身,而国内不仅探讨句子加工的心理机制本身,而且还注重探讨句子加工的心理机制所说明的问题,分析L2句子加工是否接近或相似于L1句子加工。目前,该领域的研究主要存在三种主要流派:模块说、交互说和平行说。多数学者认为L2句子加工是句法和语义加工交织的过程,即多数人接受了交互说。少数学者认为语义加工优先于句法加工。至于平行说,最近L2句子加工研究鲜有成果支持此理论。     

无单放货问题的几种解决途径及其相关的法律问题

无单放货问题被称为现代提单制度的"癌症".国际贸易界为解决无单放货问题进行了多种尝试,其中对运输单证的设计与创新主要有三种:电放、海运单以及电子提单.文章简要介绍了"电放"及"海运单"形式在实践中的应用情况及其相关的法律问题,着重分析了电子提单形式的发展和电子提单法律制度的现状,并指出顺应时代发展要求,应用电子提单,建立完善的电子提单法律制度,应是海上运输单证的发展方向.     

20世纪中国文学中的湘西书写

在20世纪的中国文学中,湘西是一个被众多作家一再书写到的地域性乡土。湘西书写,是指以湘西为表现背景,展示20世纪中国人在湘西乡土中的生活习俗、情感方式、价值判断和生存形态,以及书写者本身在这种书写过程中所体现出对湘西的认识、期待、回忆和想象。湘西书写可分为“诗意化”与“审美化”的湘西书写、“写实”与“批判”的湘西书写、“左翼”与“革命”的湘西书写、“传奇”的湘西书写四种形态。这是由不同类型的知识分子从诸如反现代与反都市、追求现代化、追求左翼与革命、追求形而上的终极与民间狂欢的立场和角度将自己对湘西的记忆、想象、感受和期盼文学化的结晶。     

浅谈张学良的军队教育理念

张学良的政治生涯始终与军人紧密地联系在一起.纵观张学良的戎马军旅生涯,他对提高军队战斗力、改善军队素质、造就军事人才有着独特的教育理念和实践.在军事技术教育方面,张学良强调要训练精兵强将;在军队政治思想教育方面,张学良强调要为民族争生存;在军纪风纪教育方面,张学良强调要造就文明之军人;在军队文化教育方面,张学良强调要培养有文化的士兵.张学良的军队教育理念是其爱国主义思想的重要组成部分,深刻地诠释着他抵御外侮、强国富民、抗日救亡、复兴民族的爱国主义思想.     

Crying for Food: The Mexican Myths of ‘La Llorona’ and ‘The Hungry Woman’ in Cherríe L. Moraga

The Mexican legend of ‘La Llorona’ (‘The Weeping Woman’), who drowned her children out of revenge for being abandoned by her lover, and the Aztec creation myth of ‘The Hungry Woman’ — crying constantly for food, with mouths all around her body — have inspired Chicana writers in the symbolic representation of their own yearning, be it sexual, identity-building, or anti-patriarchal. This essay seeks to lay the mythical groundwork within this topic, as well as to illustrate with some particular examples the different reappropriations of these myths in Cherríe L. Moraga, mainly in her play The Hungry Woman: A Mexican Medea (2001). With a view to opening up a past ‘that can provide a kind of road map to our future’ (: ix), these examples of transgressive women will be deprived of the feminine colonial passivity imbued by the dominant male discourse, and analysed as a complex, active, polyvalent mythological female corpus that integrates both life and death, womb and grave. This hybrid approach is inherent to the Aztec mythology on which Moraga relies in order to transcend Manichaeistic resolutions and probe the social, political, and gender reasons leading a hungry mother to commit infanticide.     

A powerful and efficient algorithm for breaking the links between aliased effects in asymmetric designs

Fractional factorial (FF) designs are no doubt the most widely used designs in experimental investigations due to their efficient use of experimental runs. One price we pay for using FF designs is, clearly, our inability to obtain estimates of some important effects (main effects or second order interactions) that are separate from estimates of other effects (usually higher order interactions). When the estimate of an effect also includes the influence of one or more other effects the effects are said to be aliased. Folding over an FF design is a method for breaking the links between aliased effects in a design. The question is, how do we define the foldover structure for asymmetric FF designs, whether regular or nonregular? How do we choose the optimal foldover plan? How do we use optimal foldover plans to construct combined designs which have better capability of estimating lower order effects? The main objective of the present paper is to provide answers to these questions. Using the new results in this paper as benchmarks, we can implement a powerful and efficient algorithm for finding optimal foldover plans which can be used to break links between aliased effects.     

Semiparametric inference of proportional odds model based on randomly truncated data

This paper studies the estimation in the proportional odds model based on randomly truncated data. The proposed estimators for the regression coefficients include a class of minimum distance estimators defined through weighted empirical odds function. We have investigated the asymptotic properties like the consistency and the limiting distribution of the proposed estimators under mild conditions. The finite sample properties were investigated through simulation study making comparison of some of the estimators in the class. We conclude with an illustration of our proposed method to a well-known AIDS data.     

Empirical likelihood for a partially linear model with covariate data missing at random

In this paper, we consider the partial linear model with the covariables missing at random. Empirical likelihood ratios for the regression coefficients and the baseline function are investigated, the empirical log-likelihood ratios are proven to be asymptotically chi-squared and the corresponding confidence regions for the parameters of interest are then constructed. The finite sample behavior of the proposed method is evaluated with simulation and illustrated with an AIDS clinical trial dataset.