RELIABILITY PROPERTIES OF SERIES AND PARALLEL SYSTEMS FROM BIVARIATE EXPONENTIAL MODELS

ABSTRACT

In this paper we study the classification of the generalized mixtures of two or three exponential distributions, in the ILR and DLR classes, and consequently in the IFR and DFR classes. We apply these results to classify the aging of the series and parallel systems, in accord with some common bivariate exponential models of their components.     

SUFFICIENT CONDITIONS FOR A GEOMETRIC TAIL IN A QBD PROCESS WITH MANY COUNTABLE LEVELS AND PHASES

Abstract

In this paper, we present sufficient conditions, under which the stationary probability vector of a QBD process with both infinite levels and phases decays geometrically, characterized by the convergence norm η and the 1/η-left-invariant vector x of the rate matrix R. We also present a method to compute η and x based on spectral properties of the censored matrix of a matrix function constructed with the repeating blocks of the transition matrix of the QBD process. What makes this method attractive is its simplicity; finding η reduces to determining the zeros of a polynomial. We demonstrate the application of our method through a few interesting examples.     

Polynomial Factorization for Servers with Semi-Markovian Workload: Performance and Numerical Aspects of a Verified Solution Technique

Abstract

We investigate polynomial factorization as a classical analysis method for servers with semi-Markov arrival and service processes. The modeling approach is directly applicable to queueing systems and servers in production lines and telecommunication networks, where the flexibility in adaptation to autocorrelated processes is essential.

Although the method offers a compact form of the solution with favourable computation time complexity enabling to consider large state spaces and system equations of high degree, numerical stability is not guaranteed for this approach. Therefore we apply interval arithmetic in order to get verified results for the workload distributions, or otherwise to indicate that the precision of the computation has to be improved. The paper gives an overview of numerical and performance aspects of factorization in comparison to alternative methods.     

Estimation and Welfare Analysis With Large Demand Systems

We develop an approach for estimating individual or household level preferences for a large set of quality-differentiated goods and for constructing Hicksian welfare measures within the demand system framework. Our approach uses a maximum simulated likelihood procedure to recover estimates of the structural parameters and a multistage, Monte Carlo Markov chain algorithm for constructing Hicksian consumer surplus estimates. We illustrate our approach with a recreation dataset consisting of day trips to 62 Mid-Atlantic beaches.     

2012年中国民族法学研究述评

2012年中国民族法学研究成果颇丰。其中,论文约有320余篇,比2011年增加了100余篇。这些研究在内容上有以下特点：一是内容较为全面,其中,民族习惯法、民族司法的研究比往年增多,民族政治权利成为年度重要话题;二是内容上的交叉研究增多;三是出现了一些综述性、反思性研究成果;四是关注了一些热点事件和话题;五是应用性研究成果较多。这些研究在方法上有以下特点：一是研究视角的多元化,协商民主成为年度新话题;二是注重实证研究;三是注重比较研究。在全面梳理的基础上,笔者根据研究内容所涉及的民族法学基本理论、民族权利保护、民族区域自治、民族法制建设、民族习惯法、民族法制史、民族司法等方面分别对其主要成果进行了介绍与评价,在辨别良莠、展示精华的同时,为不断繁荣中国民族法学提供可借鉴的年度综合性史料。     

Genealogies and Gene-ideologies: The Legitimacy of the Beta Israel (Falasha)

The migration of the vast majority of Beta Israel (Falasha) to Israel has been accompanied by major shifts in the discourse regarding their ‘Jewishness’ and ‘Ethiopian-ness’. This article discusses the adoption of traditions of Danite descent in place of traditions of Solomonic descent and the emergence of genetics as the most important identity marker, replacing reckonings of lineage. The first shift is connected to the migration of the Beta Israel from Ethiopia to Israel; the second to changing concepts of what represents ‘proof’ of identity in the modern and post-modern world.     

局部平稳过程、稳定过程及GARCH模型的比较研究

本文在Granger（2005）[1]研究成果的基础上对局部平稳过程的大样本性质进行了深入探讨,发现了一些颇具实际价值的理论结果,弥补了Granger（2005）仅利用预测效果标准得到金融数据生成过程的不足,进一步给出了适合于实证分析的判断金融数据生成过程的标准,并在此基础上详细讨论了局部平稳过程、稳定过程及GARCH模型在大样本情况下的区别。本文运用研究得到的结果,在非平稳框架下对中国股票市场上证180指数进行了分析,发现上证180指数收益率具有明显的非平稳特性,并在此基础上进一步讨论了中国股票市场的市场有效性问题。     

可持续发展动态评价研究——以湖北省为例

在阐明可持续发展基本理论的基础上，根据省情，从经济、社会、资源、环境四方面构建湖北省可持续发展指标体系，针对小样本数据特点，运用灰色关联分析法、偏最小二乘回归对其可持续发展状况进行动态评价。     

中国宏观经济预警体系的评价与修正

摘　　要:中国宏观经济预警体系建立于20世纪90年代初,十多年来为国家宏观调控提供了可靠的信息,成为宏观调控的主要依据之一。然而,进入本世纪以来,中国经济的运行格局发生了重大变化,导致预警体系的敏感度和预测精度出现了偏差,已经到了需要修正的时候。本文在对中国宏观预警体系分析与评价的基础上,对体系的结构与指标提出了修正的思路与方案。     

我国商业银行无形资产统计问题研究

摘　　要:商业银行无形资产是形成商业银行核心竞争力的基础和产生超额收益的源泉,加强商业银行无形资产统计工作,有利于充分揭示商业银行无形资产基本内容和对核心竞争力的影响。笔者认为,目前我国商业银行无形资产统计指标体系设置不完整,统计制度不健全,统计内容不全面,统计分析不深入,影响经济决策。笔者认为,完善商业银行无形资产统计制度时,应从组织结构类、客户关系类、知识创新类和人力资本类等四个方面对无形资产进行统计,逐步细化统计指标,明确具体的统计内容,建立、健全无形资产价值信息系统,深化无形资产统计分析工作,以此为基础,提出提高商业银行核心竞争力的基本策略。