in this paper, we investigate the performance of parametric arch class models to forecast out-of-sample var for two portfolios of tehran stock exchange (tse) companies (market portfolio and a portfolio of 50 liquid companies), using a number of distributional assumptions and sample sizes at low and high confidence levels. we find, first, that leptokurtic distributions are able to produce better...

Up until now, electronic negotiations have primarily focused on the trading of simple goods and services, where products can be described either by price alone or as a set of attributes. There is little support for trading complex, configurable products, such as computer systems, automobiles, insurances and services in general. Companies need to communicate offers including complex rules and bu...

Among all measures of independence between random variables, mutual information is the only one that is based on information theory. Mutual information takes into account of all kinds of dependencies between variables, i.e., both the linear and non-linear dependencies. In this paper we have classified some well-known bivariate distributions into two classes of distributions based on their mutua...

Recently, it has been observed that a new method for generating continuous distributions, T - X family, can be quite effectively used to analyze the data in one dimension. The aim of this study is to generalize this method to two dimensional space so that the marginals would have T - X distributions. So, several examples and properties of this family have been presented. As ...