Estimation in two-parameter exponential distributions

Exponential distributions are used extensively in the field of life-testing. Estimation of parameters is revisited in two-parameter exponential distributions. A comparison study between the maximum likelihood method, the unbiased estimates which are linear functions of the maximum likelihood method, the method of product spacings, and the method of quantile estimates are presented. Finally, a simulation study is given to demonstrate the small sample properties     

Complements or substitutes? The contingent role of corporate reputation on the interplay between internal R&D and external knowledge sourcing

Existing research does not provide a clear answer to the question of whether internal knowledge development and external knowledge sourcing are complementary or substitutive innovation activities. This paper adopts a contingent approach for addressing this issue by examining whether and how the interactive effect of internal R&D efforts and external knowledge sourcing on product innovation performance may be affected by the firm’s corporate reputation. In doing so, a three-way interaction model is applied to a sample of 251 Spanish high-technology manufacturing firms. Interestingly, initial results support the substitutive argument: the positive effect of internal R&D on product innovation performance diminishes as the exposure to external knowledge increases. However, in well reputed companies, interaction becomes positive, revealing a complementary effect. Thus, the study extends the traditional approach focused on determining whether internal and external knowledge sourcing are complements or substitutes by showing that their interplay depends on other firm-specific characteristics. Moreover, identifying corporate reputation as a source of complementarity between both activities provides an additional explanation of how corporate reputation contributes to a more effective management of knowledge assets.     

准确理解中国现行国内生产总值核算

本世纪初以来，特别是党的十八大以来，国家统计局推出了一系列统计调查制度的重大改革，对中国国内生产总值(GDP)核算的发展起到了重要的促进作用。同时，为了适应经济社会发展形势的变化，满足经济分析和管理的需要，反映国际标准的变化，国家统计局不断改进GDP的核算方法。经过国家统计局和整个政府统计系统多年的努力，中国GDP核算不断完善，数据质量和国际可比性不断提升。但是，国内外对中国GDP核算的质疑时有发生。本文对促进中国GDP核算发展的重大统计改革进行梳理，对经过多年改革和发展后中国GDP核算的主要资料来源和计算方法进行阐述，希望对用户准确了解中国GDP核算和正确使用数据有所帮助。     

RECURRENCE RELATIONS FOR SINGLE AND PRODUCT MOMENTS OF GENERALIZED ORDER STATISTICS FROM PARETO,GENERALIZED PARETO,AND BURR DISTRIBUTIONS

We give recurrence relations for single and product moments of generalized order statistics under the concept of Kamps from Pareto, generalized Pareto and Burr distributions. The results include as particular cases the above relations for moments of k–th record values.     

On Sampling Designs for Integral Estimation of a Random Process

Abstract

In this paper the problem of finding exactly optimal sampling designs for estimating the weighted integral of a stochastic process with a product covariance structure (R(s,t)=u(s)v(t), s<t) is discussed. The sampling designs for certain standard processes belonging to the product class are calculated. An asymptotic solution to the design problem also follows as a consequence.     

Classification hierarchies for product data modelling

Abstraction is an essential element in data modelling that appears mainly in one of the following forms: generalisation, classification or aggregation. In the design of complex products classification hierarchies can be found product families that are viewed as classes of product types, while product types are seen as classes of product instances. So far data models, if they support levels of classification, do not support the inheritance of product properties the way product family hierarchies are supposed to. This paper proposes an interpretation of the member of construct that enables one to define inheritance in classification hierarchies. Unified modelling language (UML) static structures are used as data modelling language. A textual notation is added that enables the introduction of data structures and corresponding data contents in the course of an analysis.     

The disassembly line: balancing and modeling,by S.M. McGovern and S.M. Gupta

This note addresses a problem faced by an actual firm. The problem is to decide on the optimal level of product quality. In performing the economic analysis to determine product quality level, the firm considers revenue, production costs, and research and development costs. However, this note shows that ignoring inventory costs in the analysis will lead to suboptimal product quality levels. Also, including inventory costs in the analysis will lead to reduced production lot sizes. Numerical examples are used to illustrate the results of the model.     

后发复杂产品系统制造企业的技术演化:一个探索性案例研究

本文采用探索性嵌入式单案例研究,以北车集团大连机车车辆有限公司八类复杂产品系统的技术发展历程为分析单元,研究发现:后发复杂产品系统制造企业的技术系统包括架构、元件和测试技术,测试技术是联接架构与元件技术的纽带;从技术获取到自主研发,三类技术分别经历了引进、消化吸收、系列化,引进、国产化与周边元件改进、核心元件研发与元件改进,以及匹配性测试、周边元件性能与匹配性测试、元件性能与匹配性测试三个发展阶段。最后通过与"简单"产品制造企业技术演化特征的比较,提出后发复杂产品系统制造企业的技术演化具有架构与元件技术并行消化吸收、测试技术促进架构与元件技术发展、核心元件技术研发模式多样的特征。     

产品缺陷及其认定标准研究

产品缺陷及其认定标准是产品责任法中一个至为重要的问题,对它的不同的解释与界定直接关系到消费者的权利要求能否实现,同时它也是产品责任法中实现责任控制、防止过度归责的一道“安全闸”。