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.     

Some further aspects of the löwner-ordering antitonicity of the moore-penrose inverse

A survey is given of known proofs of the antitonicity of the inverse matrix function for positive definite matrices w.r.t. the Lowner partial ordering, and of the corresponding result for the Moore-Penrose inverse of nonnegative definite matrices [the theorem of Milliken and Akdeniz (1977)]. A short new proof of the latter result is obtained by employing an extremal representation of a nonnegative definite quadratic form. Another proof of this result involving Schur complements is also given, and is seen to be extendable to the case of symmetric (not necessarily nonnegative definite) matrices. A geometrical interpretation of Milliken and Akdeniz's theorem is presented. As an application, the relationship between the concepts of greater (maximum) concentration and smaller (minimum) dispersion is considered for a pair (class) of vector-valued statistics with possibly degenerate distributions.     

Estimating the number of clusters

Hartigan (1975) defines the number q of clusters in a d ‐variate statistical population as the number of connected components of the set {f > c}, where f denotes the underlying density function on R^d and c is a given constant. Some usual cluster algorithms treat q as an input which must be given in advance. The authors propose a method for estimating this parameter which is based on the computation of the number of connected components of an estimate of {f > c}. This set estimator is constructed as a union of balls with centres at an appropriate subsample which is selected via a nonparametric density estimator of f. The asymptotic behaviour of the proposed method is analyzed. A simulation study and an example with real data are also included.     

社会转型期农村家庭养老功能弱化的原因解析——基于陇东南L村的调查

甘肃省东南部L村的个案表明,社会转型时期农村家庭养老功能日渐弱化,其原因在于农村人口流动的持续时问延长与范围扩大,家庭的小型化与核心家庭剧增,老人养老与子女赡养观念的分歧。为此,有必要寻求符合时代发展的新型养老模式。     

网络环境下高校财务信息系统的问题及对策

信息网络技术的迅速发展,正以前所未有的方式打破部门或组织间的界限,改变着人们思想观念、工作方式、管理模式、组织结构模式、作业流程、信息沟通方式。本文立足于这些变化,分析现行高校财务信息系统存在的问题,提出建立和完善高校财务信息系统的建议。     

绿色新政：欧洲走出危机的长期性、可持续计划

欧洲绿党所倡导的“绿色新政”,其目的在于实现在地球自然限制内带来经济繁荣、社会正义和生活幸福的经济社会的全面转型,而实现路径则依赖于对基础设施、工业产业、教育创新、社会聚合与自然环境等进行投资。由欧洲议会绿党党团委托支持、绿色智库“重构”完成的这一研究报告,试图构建一个相对不利环境下如何达到改变欧洲经济与社会状况的投资水平的金融体制。它认为,欧盟每年需将GDP的2%投资到2020年时实现CO2排放减少30%目标的工作中,并建议财源的主体应是私人投资,同时国家创造必需的激励和支持以吸引这些私人投资。     

论吉林省发展战略性新兴产业的金融支持

本文以我国目前大力发展的战略性新兴产业为背景,站在地区发展的角度,结合吉林省自身的产业基础与科技优势,提出了一条适应我省战略性新兴产业发展的金融支持路径,并为完善该金融支持体系提供了理论支持和政策建议.     

浅谈环境会计

文章对环境会计基本构成如环境会计目标、基本原则、环境问题对财务活动的影响、环境会计学分析等几个方面进行了深入研究 ,提出构建环境会计学的基本设想 ,为我国企业健康科学地发展 ,提供必要的财会业务支持     

环保产业发展的社会支撑系统

我国环境问题的特殊性,导致环保产业的发展存在一系列的制度障碍。如何创建一个相对有效和公平的激励体制,亦即社会支撑系统,从而促进环保产业的发展,是摆在决策者和研究者面前的一项紧迫任务。     

构建以市场透明度为核心的资本市场秩序

建立在资本市场基础上的现代金融体系,以其杠杆化的功能,已经成为或正在成为现代经济不断成长的强大推动器。因此,资本市场秩序的规范和建设也就必然成为整个市场秩序形成的核心环节和重要基础。资本市场秩序的核心是维护市场透明度。通过对市场透明度进行理论分析,可以发现,虚假陈述、内幕交易和操纵市场是造成资本市场秩序失衡的三大行为,因此,必须规范公司治理,建立尽责的中介机构,制定符合现代经济活动要求的会计准则,形成有效的监管体系,不断完善法律体系,从而完善资本市场秩序。