Estimation of the Pareto law from underreported data: A further analysis

Estimation of parameters of the Pareto income distribution is discussed for the situation when data are underreported, i.e., observed with negative random bias. Specifically it is proved that maximum likelihood estimates are consistent and asymptotically normal in large samples, and formulae for the large-sample standard errors are given. The large-sample theory illustrates how some important results from mathematical statistics apply to non-standard statistical models.     

Problems in the estimation and interpretation of the reliability of survey data

In this paper I discuss several of the difficulties involved in estimating the reliability of survey measurement. Reliability is defined on the basis of classical true-score theory, as the correlational consistency of multiple measures of the same construct, net of true change. This concept is presented within the framework of a theoretical discussion of the sources of error in survey data and the design requirements for separating response variation into components representing such response consistency and measurement errors. Discussion focuses on the potential sources of random and nonrandom errors, including “invalidity” of measurement, the term frequently used to refer to components of method variance. Problems with the estimation of these components are enumerated and discussed with respect to both cross-sectional and panel designs. Empirical examples are given of the estimation of the quantities of interest, which are the basis of a discussion of the interpretational difficulties encountered in reliability estimation. Data are drawn from the ISR's Quality of Life surveys, the National Election Studies and the NORC's General Social Surveys. The general conclusion is that both cross-sectional and panel estimates of measurement reliability are desirable, but for the purposes of isolating the random component of error, panel designs are probably the most advantageous.     

A cautionary note on methods of comparing programmatic efficiency between two or more groups of DMUs in data envelopment analysis

In some applications of data envelopment analysis (DEA) there may be doubt as to whether all the DMUs form a single group with a common efficiency distribution. The Mann–Whitney rank statistic has been used to evaluate if two groups of DMUs come from a common efficiency distribution under the assumption of them sharing a common frontier and to test if the two groups have a common frontier. These procedures have subsequently been extended using the Kruskal–Wallis rank statistic to consider more than two groups. This technical note identifies problems with the second of these applications of both the Mann–Whitney and Kruskal–Wallis rank statistics. It also considers possible alternative methods of testing if groups have a common frontier, and the difficulties of disaggregating managerial and programmatic efficiency within a non-parametric framework.      

特高压输电线路电晕可听噪声研究综述

随着特高压交直流输电网的建设,电晕可听噪声引起环保纠纷也日趋增多,因此,研究输电线路电晕可听噪声的来源、形成机理以及相关降噪措施,对构建环境友好型社会具有重要意义。文章通过对以往研究成果的归纳总结,综合分析了特高压输电线路正/负极性电晕可听噪声特征,湿度、降雨及污秽对电晕可听噪声的影响机制和电晕可听噪声的测量方法,并探讨了输电线路降噪的相关技术路线。     

Estimating the impact of regional policy: A review of applied research methods

This paper provides a critical review of the methodological approaches that have been used to estimate the impacts of regional economic policies. A considerable variety of approaches are examined, ranging from questionnaire studies through single- and multiple-equation regression models to cost-benefits analysis, and attention is focused on the pros and cons of these approaches and the reliability of the impact assessments derived. The paper concludes with some suggestions for further research in this field.     

On the determinants of data breaches: A cointegration analysis

Decisions in Economics and Finance - Cyber risks and particularly data breaches constitute one of the new frontiers of risk modeling for insurers across the world. We use the cointegration...     

Timing and duration effects in residence histories and other longitudinal data: Part 1. Stochastic and statistical models; Part 2. Studies of duration effects in Norway, 1965-1971

The author describes an attempt to fit stochastic models to individual life histories. "In particular, [he] is concerned with the application of semi-Markov processes to the study of the timing of moves and duration of residence effects in the migration histories of Norwegian men over the period 1965-1971." In the second part of the article, the results of 11 studies using data on Norwegian men are presented     

浅析会计电算化工作中出现的问题及对策

会计电算化对我国企业的发展起到了极大的推动作用,但是随着会计电算化的飞速发展,实践工作中也出现了一些新的问题,阻碍了会计电算化向更深层次的发展,文章针对这些问题进行了阐述并提出相应的对策。     

Recent advances in intra-hour solar forecasting: A review of ground-based sky image methods

As the penetration of solar energy generation into power systems keeps rising, intra-hour solar forecasting (IHSF) is becoming increasingly important for the secure and economical operation of a power system. One major difficulty in providing very accurate IHSF emanates from rapid cloud changes in the sky. The ground-based sky image (GSI) provides the intuitive information of intra-hour cloud changes and has thus been widely utilized in studies on IHSF. This paper presents a systematic review of the state-of-the-art of ground-based sky image-based intra-hour solar forecasting (GSI-IHSF). To our knowledge, we first propose a generic framework of GSI-IHSF consisting of four modules, i.e., sky image acquisition, sky image preprocessing, cloud forecasting, and solar forecasting. Then, as for each module, this paper introduces its core function, shows the major challenges, briefly reviews several extensively used techniques, summarizing research trends. Finally, this paper offers a prospect of GSI-IHSF research, discusses recent advances that demonstrate the potential for a great improvement in forecast accuracy, pointing out some new requirements and challenges that should be further investigated in the future.     

物流现代化的关键技术之一：物流标识技术

本文以供应链物流为研究对象,专门阐述物流标识技术。对物流标识技术中的物流编码技术与物流条码符号标识技术进行了分析,并对物流标识技术在国内外物流领域的应用作了介绍     

The importance of efficient use in the adoption of technology: A micro panel data analysis

Even after the introduction of the new rice technology (Green revolution) about more than two decades ago, the food shortage problem has not decreased significantly in many developing countries. Obviously, there can be no dispute over the importance of the new rice technology in bringing about improvements in agricultural productivity. But, there are factors other than the choice of technology which are equally important, and a neglect of these factors may lead to a complete negation of any possible gains in productivity arising from the use of new technology. One such factor is the efficient use of the technology. This paper examines farm-specific application of the new rice technology by using a micro-level panel data from a South Indian district. The results show a wide variation in the efficient use of the technology by the sample farmers. Extension and education were identified as two major constraining factors.The refereeing process of this paper was handled through N.R. Adam.     

Approximating the solution of an integral equation arising in the theory of risk: A comment

This note describes accelerated two sided approximation schemes for the solution of the integral equation

基于因子分析的北京城市功能空间布局研究

论文以北京市为例,采用因子分析法,对北京市内18区县反映城市发展状况指标进行定量综合评估,以明确北京市各区县城市发展的主导因素,为确定各区县发展优势及功能定位提供科学依据.并结合北京市现有城市功能空间分布特点,提出在城市服务核心区(主城区)和生态涵养区(山区)之间的城市功能拓展区内,建立朝阳-通州、丰台、石景山、海淀4个发展区.通过在各发展区内形成人流、物流循环,分担主城区人口、功能过于集中的压力.并通过功能区之间的产业连接,形成环状产业发展轴,构成北京国际化大都市发展骨架.     

Earnings inequality in Hungary: A comparative analysis of household and enterprise survey data

This study examines trends in the distribution of gross earnings in Hungary since 1988, using official household budget surveys and enterprise-based earnings surveys. We find a significant growth in inequality since 1988, to levels comparable with western Europe. There is little evidence of a serious discrepancy between the two data sources used.     

Healthcare information systems: data mining methods in the creation of a clinical recommender system

Recommender systems have been extensively studied to present items, such as movies, music and books that are likely of interest to the user. Researchers have indicated that integrated medical information systems are becoming an essential part of the modern healthcare systems. Such systems have evolved to an integrated enterprise-wide system. In particular, such systems are considered as a type of enterprise information systems or ERP system addressing healthcare industry sector needs. As part of efforts, nursing care plan recommender systems can provide clinical decision support, nursing education, clinical quality control, and serve as a complement to existing practice guidelines. We propose to use correlations among nursing diagnoses, outcomes and interventions to create a recommender system for constructing nursing care plans. In the current study, we used nursing diagnosis data to develop the methodology. Our system utilises a prefix-tree structure common in itemset mining to construct a ranked list of suggested care plan items based on previously-entered items. Unlike common commercial systems, our system makes sequential recommendations based on user interaction, modifying a ranked list of suggested items at each step in care plan construction. We rank items based on traditional association-rule measures such as support and confidence, as well as a novel measure that anticipates which selections might improve the quality of future rankings. Since the multi-step nature of our recommendations presents problems for traditional evaluation measures, we also present a new evaluation method based on average ranking position and use it to test the effectiveness of different recommendation strategies.     

On the use of grouping methods in the analysis of residential housing markets

In this article we employ four different statistical techniques (geographic, AID, cluster and discriminant analysis) to define homogeneous groupings of houses within an urban area. Analysis of a sample of data from Fayette Country, Kentucky indicates that each of these methods produces distinguishable homogeneous groupings of properties. Predictions of house values are compared using data from Lane County, Oregon, San Mateo County, California, and Fayette County. The major conclusions of the study are that there are no discernible differences among the four methods and that predictions made ignoring the grouping information are as accurate as those obtained by grouping.     

Interpreting the results of studies using latent variable models to assess data quality: an empirical example using confirmatory factor analysis

Latent variable models (LVMs) offer one route to examine the quality of data collected in surveys. The possibility exists that individuals equivalent in their true level of a construct or variable being measured are unlikely to have equivalent observed responses as a function of an extraneous variable, e.g., group membership. This potential is labeled here as differential item functioning (DIF). Survey methods generally considers measurement bias to be estimators that do no not accurately reflect true values. DIF may be thought of as differential measurement bias, i.e., measurement bias conditional on group membership. As a function of group membership, the degree, amount, or type of measurement bias changes. DIF has the potential to negatively affect the quality of data. LVMs, e.g., confirmatory factor analysis (CFA), offer one tool to assess DIF. However, few published examples exist in the survey research field and training in the interpretation of these models is lacking. The purpose of the current paper is to describe CFA sufficiently for interpretive purposes and demonstrate an empirical application of CFA to assess survey data quality to provide further interpretive guidance. References are provided for analysts wishing to conduct analyses of this type.