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11.
本文通过直方图和Q-Q图的直观方法展示了上证指数和深证指数的对数收益率具有尖峰厚尾和偏斜的分布特征,利用Shapiro-Wilk正态性检验和Kolmogorov-Smirnov检验等方法检验了对数收益率的分布与正态分布有显著性差异,并以较大的概率水平接受了对数收益率服从偏斜Logistic分布,同时给出了基于偏斜Logistic分布的VaR风险量的估计,结果显示上证指数的风险小于深证指数的风险。 相似文献
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We analyze the underlying economic forces of the stock markets in Germany, the U.K. and the U.S. Identifying a number of variables evincing return predictability, we follow a partial least‐squares (PLS) approach to combine these observables into a few latent factors. Conditional on European markets, our findings indicate (i) superior prediction performance of PLS‐based schemes in comparison with both, a random walk and a first‐order autoregressive benchmark model, (ii) consistent profitable trading on the German and British market, (iii) profitable linear forecast combinations, (iv) the U.S. stock market is diagnosed as informationally efficient. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Shib Sankar Sana 《Applied mathematics and computation》2011,218(7):3277-3288
The paper deals with an inventory model to determine the retailer’s optimal order quantity for similar products. It is assumed that the amount of display space is limited and the demand of the products depends on the display stock level where more stock of one product makes a negative impression of the another product. Besides it, the demand rate is also dependent on selling price and salesmen’s initiatives. Also, the replenishment rate depends on the level of stock of the items. The objective of the model is to maximize the profit function, including the effect of inflation and time value of money by Pontryagin’s Maximal Principles. The stability analysis of the concerned dynamical system has been done analytically. 相似文献
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Ramiro Varela Camino R. Vela Jorge Puente María Sierra Inés González-Rodríguez 《Annals of Operations Research》2009,166(1):125-146
We confront a practical cutting stock problem from a production plant of plastic rolls. The problem is a variant of the well-known
one dimensional cutting stock, with particular constraints and optimization criteria defined by the experts of the company.
We start by giving a problem formulation in which optimization criteria have been considered in linear hierarchy according
to expert preferences, and then propose a heuristic solution based on a GRASP algorithm. The generation phase of this algorithm
solves a simplified version which is rather similar to the conventional one dimensional cutting stock. To do that, we propose
a Sequential Heuristic Randomized Procedure (SHRP). Then in the repairing phase, the solution of the simplified problem is
transformed into a solution to the real problem. For experimental study we have chosen a set of problem instances of com-mon
use to compare SHRP with another recent approach. Also, we show by means of examples, how our approach works over instances
taken from the real production process.
All authors are supported by MEC-FEDER Grant TIN2007-67466-C02-01 and by contract CN-05-127 of the University of Oviedo and
the company ERVISA, and by FICYT under grant BP04-021. 相似文献
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Adriana Cristina Cherri Marcos Nereu Arenales Horacio Hideki Yanasse 《European Journal of Operational Research》2009
In this work we consider a one-dimensional cutting stock problem in which the non-used material in the cutting patterns may be used in the future, if large enough. This feature introduces difficulties in comparing solutions of the cutting problem, for example, up to what extent a minimum leftover solution is the most interesting one when the leftover may be used. Some desirable characteristics of good solutions are defined and classical heuristic methods are modified, so that cutting patterns with undesirable leftover (not large enough to be used, nor too small to be acceptable waste) are redesigned. The performance of the modified heuristics is observed by solving instances from the literature, practical instances and randomly generated instances. 相似文献
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Abstract Population features inferred from single‐species, age‐structured models are compared to those inferred from a multispecies, age‐structured model that includes predator‐prey interactions among three commercially harvested fish species—walleye pollock, Atka mackerel, and Pacific cod—on the Aleutian Shelf, Alaska. The multispecies framework treats the single‐species models and data as a special case of the multispecies model and data. The same data from fisheries and surveys are used to estimate model parameters for both single‐species and multispecies configurations of the model. Additionally, data from stomach samples and predator rations are used to estimate the parameters of the multispecies model. One form of the feeding functional response, predator pre‐emption, was selected using AIC from seven alternative models for how the predation rate changes with the densities of prey and possibly other predators. Differences in estimated population dynamics and productivity between the multispecies and single‐species models were observed. The multispecies model estimated lower mackerel population sizes from 1964–2003 than the single‐species model, while the spawning biomass of pollock was estimated to have declined more than three times faster since 1964 by the multispecies model. The variances around the estimates of spawning biomass were smaller for mackerel and larger for pollock in the multispecies model compared to the single‐species model. 相似文献
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证券市场内幕交易有信息含量的临界点值推算 总被引:1,自引:0,他引:1
中国证券市场内幕交易的同时存在市场操纵行为,使得独立判断内幕交易的信息含量存在困难.为解决判断纯粹内幕交易是否具有信息含量问题,需要确定内幕交易具有信息含量的临界点值.采用我国证券市场内幕交易与操纵样本数据,先在操纵均衡点附近排除市场操纵的影响,然后推算出无消息、无操纵状态下证券随同大盘运动的理论增长路径,在此基础上比较基于内幕信息操纵和理论增长情况,通过设定与理论增长的倍数关系,推算纯粹内幕交易具有信息含量的临界点值:异常收益应大于3%.该值可以解释现有文献认为内幕交易有或没有信息含量的矛盾与争论.应用于中国内幕交易实际情况及与近年国际相关研究文献对照,临界点值得到支持. 相似文献
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