Stock Repurchase and the Role of Signaling： A Comparative Analysis between U.S. and China

This paper compares different methods used for stock repurchase and examines the role of signaling in the U.S. and China＇s capital markets. We find that the ways to buyback stocks are very different in the two countries. Most U.S. stocks are repurchased through open market and the signals sent to the market through open market repurchase are getting weaker. Even though stock repurchases are at their early stage in the Chinese stock market and the dominated way to buyback is through a negotiated repurchase agreement for non-floating shares, the power of signaling seems much stronger. Examining stock prices pre- and post-repurchase, we find that stock repurchase records an average abnormal return of 3.42% on the announcement date and 3.24% on the date of actual renurchase.     

数据迁移的研究

在信息化建设过程中,随着技术的发展,原有的信息系统不断被功能更强大的新系统所取代。在新旧系统的切换过程中,必然要面临一个数据迁移的问题。本文研究了数据迁移的本质,根据具体的课题提出了数据迁移的方法和分类。     

机动平台识别器方位零值的几种标校方法

方位零值标校是识别器设邸统标校的一项重要内容。针对机动平台识别器设备进场安装，提出了几种标校方法，旨在解决机动平台识别器的方位零值标校问题。     

中小企业股票市场化发行定价的半参数自组织模型与实证

随着深圳交易所中小企业板块的正式启动，我国中小企业新股发行的市场化定价方式必将启用。本文采用基于自组织数据挖掘GMDH算法的半参数模型的定价方法，将GMDH算法与半参数模型方法结合起来。不仅利用计算机的自动拟合优选最优复杂度模型，从而大大简化了非参数部分估计。创造了半参数模型崭新的实现方式，并达到了理想的定价效果，而且可以发挥半参数模型的特有优势。进行模型结构分析。经过实证和检验证明了这种模型用于我国股票发行定价的有效性和合理性。为完全市场化股票发行方式下确定股票的发行价格提供了新的方法。     

On the Role of Weight Restrictions in Data Envelopment Analysis

This paper examines the role that weight restrictions play in Data Envelopment Analysis (DEA). It is argued that the decision to include a factor (input or output) in a DEA model represents an implicit judgement that the factor has a non-trivial weight. It therefore seems perverse to allow DEA to assign a trivial weight to that factor in assessing the efficiency of a unit. There is therefore a strong case for imposing restrictions on factor weights. However, many existing methods of weight restriction are in practice unwieldy. This paper proposes an alternative approach we term contingent weight restriction which is both practical and intellectually consistent with the DEA philosophy. The paper explores the implications of alternative methods of weight restriction using simulated data from a well known production process.     

数据标准化框架研究

文章对数据标准化涉及的一些术语进行了定义,包括数据、数据元、元数据、元模型、元数据注册系统等。在此基础上提出数据标准化包括以下几个主要方面:数据内容(语义),交换格式(语法,包括数据结构和模式),形式化表示,数据维护机制和平台。这几项内容构成了数据!标准化的基本框架。     

基于制造业ERP构建企业多层数据仓库

文章针对目前制造业ERP在决策支持方面的不足,提出了基于制造业ERP构建由标准数据仓库、多维数据库和数据挖掘库等组成的企业多层数据仓库体系框架,阐述了该体系框架的构建方法和过程,并分析了一个应用实例。     

Productive Efficiency of the Swine Industry in Hawaii: Stochastic Frontier vs. Data Envelopment Analysis

Improving productive efficiency is an increasingly important determinant of the future of the swine industry in Hawaii. This paper examines the productive efficiency of a sample of swine producers in Hawaii by estimating a stochastic frontier production function and the constant returns to scale (CRS) and variable returns to scale (VRS) output-oriented DEA models. The technical efficiency estimates obtained from the two frontier techniques are compared. The scale properties are also examined under the two approaches. The industry's potential for increasing production through improved efficiency is also discussed.     

Localized Innovation and Productivity Growth in Asia: An Intertemporal DEA Approach

Recent contributions to growth theory stress the importance of localized innovation for the performance of more backward countries. In earlier papers, analyses by means of DEA techniques confirmed this intuition. In this paper, we extend this type of analysis by relaxing the macroeconomic viewpoint adopted until now. New databases on output, labor and capital input in the agricultural and manufacturing sectors are developed for 40 countries. Using intertemporal DEA, it is found that changes in the global production frontier are localized at high levels of capital intensity. This result is stronger in agriculture than in manufacturing. Further, a decomposition of labor productivity growth in eight Asian countries for the period 1975–1992 into the effects of capital intensification, learning and innovation is made. The results suggest that there is a particular development path in which increases in capital intensity appear to be a prerequisite to benefit from international technology spillovers.JEL Classification: O14, O30, O40, O47     

Lower Bound Restrictions on Intensities in Data Envelopment Analysis

We propose an extension to the basic DEA models that guarantees that if an intensity is positive then it must be at least as large as a pre-defined lower bound. This requirement adds an integer programming constraint known within Operations Research as a Fixed-Charge (FC) type of constraint. Accordingly, we term the new model DEA_FC. The proposed model lies between the DEA models that allow units to be scaled arbitrarily low, and the Free Disposal Hull model that allows no scaling. We analyze 18 datasets from the literature to demonstrate that sufficiently low intensities—those for which the scaled Decision-Making Unit (DMU) has inputs and outputs that lie below the minimum values observed—are pervasive, and that the new model ensures fairer comparisons without sacrificing the required discriminating power. We explain why the low-intensity phenomenon exists. In sharp contrast to standard DEA models we demonstrate via examples that an inefficient DMU may play a pivotal role in determining the technology. We also propose a goal programming model that determines how deviations from the lower bounds affect efficiency, which we term the trade-off between the deviation gap and the efficiency gap.