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1.
Many recent papers have used semiparametric methods, especially the log-periodogram regression, to detect and estimate long memory in the volatility of asset returns. In these papers, the volatility is proxied by measures such as squared, log-squared, and absolute returns. While the evidence for the existence of long memory is strong using any of these measures, the actual long memory parameter estimates can be sensitive to which measure is used. In Monte-Carlo simulations, I find that if the data is conditionally leptokurtic, the log-periodogram regression estimator using squared returns has a large downward bias, which is avoided by using other volatility measures. In United States stock return data, I find that squared returns give much lower estimates of the long memory parameter than the alternative volatility measures, which is consistent with the simulation results. I conclude that researchers should avoid using the squared returns in the semiparametric estimation of long memory volatility dependencies.  相似文献   
2.
Empirical applications of poverty measurement often have to deal with a stochastic weighting variable such as household size. Within the framework of a bivariate distribution function defined over income and weight, I derive the limiting distributions of the decomposable poverty measures and of the ordinates of stochastic dominance curves. The poverty line is allowed to depend on the income distribution. It is shown how the results can be used to test hypotheses concerning changes in poverty. The inference procedures are briefly illustrated using Belgian data. An erratum to this article can be found at  相似文献   
3.
江南水乡古镇旅游业发展20多年以来,商业化现象日益严重,古镇沿街充斥着服务旅游者的各色同质化的商铺和商品,不仅冲淡古镇原真景观特征,形成古镇因利趋同格局,而且改变了居民生活方式并成为重要的生活基础,直接干扰居民日常生活,破坏古镇整体人文生态系统的和谐,破坏古镇原有自然风貌和景观环境。立足于古镇原真性保护,在商业化快速发展的过程中政府应淡出商业利益,严格控制商业发展;拓展和营造多样化社区参与旅游的方式和途径,调整利益分配体制,建立行业利益平衡机制;鼓励和发展传统手工艺,形成旅游体验与民间非物质文化遗产保护双赢格局。  相似文献   
4.
孔子学院的发展现状、问题及趋势   总被引:10,自引:2,他引:8  
孔子学院是以教授汉语和传播中国文化为宗旨的非营利的公益机构,是海外朋友学习汉语了解中国的窗口,也是学习借鉴不同文化、促进多元文化交流发展而构建和谐世界的平台。作为汉语国际推广的龙头产品,孔子学院的建设已经初具规模,发展的势头引人瞩目。本文谨就孔子学院的发展现状、存在问题以及未来的趋势作一概括性的阐述和分析。  相似文献   
5.
Summary.  A stochastic discrete time version of the susceptible–infected–recovered model for infectious diseases is developed. Disease is transmitted within and between communities when infected and susceptible individuals interact. Markov chain Monte Carlo methods are used to make inference about these unobserved populations and the unknown parameters of interest. The algorithm is designed specifically for modelling time series of reported measles cases although it can be adapted for other infectious diseases with permanent immunity. The application to observed measles incidence series motivates extensions to incorporate age structure as well as spatial epidemic coupling between communities.  相似文献   
6.
文学思潮是一个时代的文学创作潮流中所表现出来的那个社会的时代精神和社会风尚,以及那个时代起主导作用的文学创作的理论和方法。文学思潮有以下几个特点一、深层性;二、理论性;三、群体性;四、时段性;五、实践性。对于划分和命名文学思潮,应该尽可能地宽容。然而,宽容并不是没有原则。当代中国文坛独特的结构和制度,决定了当代文学思潮的特点。主要表现在一、文学理论和创作极度密切的关系;二、文学思潮少有自发产生的,基本上是自觉的、自上而下提倡的;三、由于基本是自觉的,所以是理性的。  相似文献   
7.
In electrical engineering, circuit designs are now often optimized via circuit simulation computer models. Typically, many response variables characterize the circuit's performance. Each response is a function of many input variables, including factors that can be set in the engineering design and noise factors representing manufacturing conditions. We describe a modelling approach which is appropriate for the simulator's deterministic input–output relationships. Non-linearities and interactions are identified without explicit assumptions about the functional form. These models lead to predictors to guide the reduction of the ranges of the designable factors in a sequence of experiments. Ultimately, the predictors are used to optimize the engineering design. We also show how a visualization of the fitted relationships facilitates an understanding of the engineering trade-offs between responses. The example used to demonstrate these methods, the design of a buffer circuit, has multiple targets for the responses, representing different trade-offs between the key performance measures.  相似文献   
8.
词汇研究新趋势与英汉词汇对比研究的方法和内容   总被引:1,自引:0,他引:1  
经过100多年的演变和发展,现代语言学研究取得了丰硕的成果,对词汇研究产生了巨大的影响。为适应词汇研究的新趋势,现代英汉词汇对比研究应突破传统的窠臼,找准确有可比性的研究对象,在理论和方法上显示现代哲学、现代语言学、现代语义学和数理语言学的特色。  相似文献   
9.
Joyce T. Chen 《决策科学》1980,11(4):632-647
This paper applies mathematical programming to cost-volume-profit (CVP) analysis under contribution margin uncertainty. Three CVP probabilistic chance-constraint models based on various safety-first criteria for decisions under uncertainty are presented and compared. It is shown that a break-even segment of the mean-standard deviation frontier is a set of optimal solutions for the proposed models. An operational parametric quadratic programming (QP) model is constructed, and the efficiency frontier is generated. The procedures for locating an optimal solution on the efficiency frontier are then presented. The recommended QP procedure offers both technical relief from the computational difficulties posed by the probabilistic constraints and a desired flexibility in generating and presenting the relevant information for decisions under uncertainty.  相似文献   
10.
A great majority of methods designed for Multiple Criteria Decision Aiding (MCDA) assume that all assessment criteria are considered at the same level, however, decision problems encountered in practice often impose a hierarchical structure of criteria. The hierarchy helps to decompose complex decision problems into smaller and manageable subtasks, and thus, it is very attractive for computational efficiency and explanatory purposes. To handle the hierarchy of criteria in MCDA, a methodology called Multiple Criteria Hierarchy Process (MCHP), has been recently proposed. MCHP permits to consider preference relations with respect to a subset of criteria at any level of the hierarchy. Here, we propose to apply MCHP to the ELECTRE III ranking method adapted to handle three types of interaction effects between criteria: mutual-weakening, mutual-strengthening and antagonistic effect. We also involve in MCHP an imprecise elicitation of criteria weights, generalizing a technique called the SRF method. In order to explore the plurality of rankings obtained by the ELECTRE III method for possible sets of criteria weights, we apply the Stochastic Multiobjective Acceptability Analysis (SMAA) that permits to draw robust conclusions in terms of rankings and preference relations at each level of the hierarchy of criteria. The novelty of the whole methodology consists of a joint consideration of hierarchical assessments of alternatives performances on interacting criteria, imprecise criteria weights, and robust analysis of ranking recommendations resulting from ELECTRE III. An example regarding the multiple criteria ranking of some European universities will show how to apply the proposed methodology on a decision problem.  相似文献   
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