On the Shoulders of Giants: Co-location with Dominant Firms in the Emerging Fiber Optics Industry

In this study we investigate the location choices of start-ups and established firms relative to dominant firms in the US fiber optics industry from 1976 to 1994. We test the propensity to co-locate with dominant firms and whether proximity to a dominant firm impacts the strategic choices made by start-ups and established firms. Contrary to our predictions, we find that both start-ups and established firms are equally likely to co-locate with dominant firms. We also find that start-ups exhibit greater new product adoption rates and greater product-line breadth than established firms. This implies that start-ups are relatively more likely to realize greater strategic gains with entry into emerging markets.     

与时俱进 顽强创新 提高层次

以亲身经历记述了学校如何从一所名不见经传的普通中等职业学校发展成为一所大专层次的普通高等职业技术学院。多年来 ,学校坚持了以需求和发展的观点看职教 ,以顽强和创新的精神办职教 ,走产、学、研一体化的办学道路和以人为本的教育理念 ,与时俱进、开拓创新 ,办出了自己的特色。     

基于网上研究院的报告管理系统

介绍在网上研究院的基础上开发的报告管理系统,对技术报告管理、检测报告管理过程中的审批流程以及工作流进行了介绍。     

专利服务机构网络营销模式优化研究

以某专利服务机构网络营销为背景,采用网络调查方法,结合国内中小企业的特点,以达到提高该平台和专利网站的服务功能、服务能力和服务手段等目的,从而优化专利服务机构网络营销模式,实现全方位地协助中国中小企业创新,帮助企业提升其核心竞争力。     

党建工作考核机制的实践与思考

党建工作是企业管理的有机组成部分,是现代国有企业制度建设的重要内容。建立科学规范的党建工作考核机制,是全面落实党建工作责任制的重要途径。从党建工作与生产经营深度融合的角度出发,分析了建立科学规范的党建工作考核的必要性,对如何分层分级开展党建工作考核,推进企业核心竞争力提升等,从企业实践方面提出了一些对策和建议。     

ARMA MODELLING WITH NON-GAUSSIAN INNOVATIONS

Abstract. The problem of modelling time series driven by non-Gaussian innovations is considered. The asymptotic normality of the maximum likelihood estimator is established under some general conditions. The distribution of the residual autocorrelations is also obtained. This gives rise to a potentially useful goodness-of-fit statistic. Applications of the results to two important cases are discussed. Two real examples are considered.     

GENERALIZED SEASONAL ARIMA PROCESSES: REGULARITY/SINGULARITY CRITERIA AND LINEAR PREDICTION

Abstract. Criteria for any generalized seasonal ARIMA model to be a regular or to be a singular process are given and a new basic form of predictors for ARIMA processes is obtained, that can be computed in a simple way.     

MAXIMUM LIKELIHOOD ESTIMATION OF AUTOCOVARIANCE MATRICES FROM REPLICATED SHORT TIME SERIES

Abstract. The maximum likelihood estimation of an autocovariance matrix based on replicated observations of stationary times series is considered. A sufficient condition for the existence of the estimate, when the sample covariance matrix is singular, is given. An iterative method for its computation is proposed: it is based on some spectral decompositions of Toeplitz matrices. Simulation results show the superiority of the estimate over the usual empirical sample autocovariance matrix.     

TIME-REVERSIBILITY, IDENTIFIABILITY AND INDEPENDENCE OF INNOVATIONS FOR STATIONARY TIME SERIES

Abstract. Weiss ( J. Appl. Prob. 12 (1975) 831–36) has shown that for causal autoregressive moving-average (ARMA) models with independent and identically distributed (i.i.d.) noise, time-reversibility is essentially unique to Gaussian processes. This result extends to quite general linear processes and the extension can be used to deduce that a non-Gaussian fractionally integrated ARMA process has at most one representation as a moving average of i.i.d. random variables with finite variance. In the proof of this uniqueness result, we use a time-reversibility argument to show that the innovations sequence (one-step prediction residuals) of an ARMA process driven by i.i.d. non-Gaussian noise is typically not independent, a result of interest in deconvolution problems. Further, we consider the case of an ARMA process to which independent noise is added. Using a time-reversibility argument we show that the innovations of the ARMA process with added independent noise are independent if and only if both the driving noise of the process and the added noise are Gaussian.     

对三峡工程建设几个问题的再认识

在三峡工程全面实现二期工程蓄水、通航、发电三大目标之际，全面回顾80多年来人们对三峡工程认识的深化过程，就世人关注的工程生态环境问题、水库移民问题、泥沙问题、工程理性与工程备战问题、工程质量问题、工程管理问题以及三峡总公司未来前景等问题进行了系统、深入的分析。三峡总公司的前景会越来越美好。