电力变压器抽检质量问题分析及管控措施分析

电力变压器是电网系统中重要的配件,其质量直接关系到电力系统运行的安全性能。文章就电力变压器的抽检方法做出了简要的分析,并以此为例,对电网电力系统的35 k V电力变压器进行了质量抽检,详细分析了抽检情况,立足于用户,提出了几点加强变压器质量管理的举措。     

Epistemological reasons for preferring component analysis to factor analysis

Spearman's and Thomson's mathematical controversy over factor theory was forgotten when it became evident that empirical tetrad-differences bound away from zero (and when empirical evidence argued the need for extracting more factors from a matrix). In fact, both their models lead to zero tetraddifferences. Being more interested in the psychological than in the mathematical aspects of Spearman's model. Thompson remained indifferent to mathematical aspects of multiple factor analysis when Thurstone theorized it. Thus, he did not perceive that his counter-example negated the assumption Thrustone shared the rank of the matrix. The idea that components to be extracted must be equal to the rank of the matrix is not assumed in Hotelling's component model: as a result, this is the first epistemological reason for preferring component analysis to factor analysis. A second epistemological reason is the central theorem of Thurstone's multiple-factor model, which can be criticized because it is an assumption that, the rank of a complete matrix being n, it becomes k when commonalities are in the principal diagonal. This assumption goes against common sense, a fact demonstrated through comparison between residuals after k components have been extracted and after k principal factors have been extracted.     

Fuzzy logic programming based knowledge analysis for qualitative comparative analysis

This paper presents a way to combine outcomes of various studies in a meta analysis framework that can use the results of mixed methods and also provide query based output for intelligent decision making. We enhance the Qualitative Comparative Analysis by utilizing fuzzy logic programming to provide effective ways of combining output of various studies. The results from various studies are used to develop an axiomatic knowledge database, and then the fuzzy programming logic engine processes it to present logical answers to decision maker’s queries to the system. We present a sample application to show the methodology being applied to an example problem.     

沉井下沉分析

沉井的施工工艺并不复杂,施工时对邻近建筑物的影响较小,内部空间可以利用,因此在工程上,沉井有广泛的应用。文章依据长沙市北站路泵站的实例,对沉井下沉进行分析。     

Conditional regression analysis

This article deals with the question of whether the inclusion of multiplicative terms to model conditional effects in multiple regression is legitimate. The major arguments in the controversy relating to this subject are reviewed. The main conclusion is that most of the objections against multiplicative terms are based on misinterpretations of the coefficients of conditional models. For the often-ignored possible numerical problems in the estimation of these models, due to multicollinearity, an indirect estimation technique is proposed. The potentials of conditional regression analysis are demonstrated on a concrete example.     

Time series analysis

Time series analysis has undergone radical changes in recent years. The objectives of time series analysis remain the same, but the techniques have changed. Box and Jenkins (1968, 1970; see also Nelson, 1973) particularly have introduced a class of models which have a wide variety of applications in time series modelling. The purpose of this paper is to examine the relevance of their approach to political science, to introduce their techniques to the student unfamiliar with their work, and to discuss future developments in this area in relation to political science methodology. The sections involve an analysis of their approach, then an example of their model building strategy applied to poll data and, finally, a discussion of future developments. But before embarking on the main discussion it is useful to examine the objectives of time series analysis in general and to distinguish it from other areas of statistical analysis in the social sciences.     

Contextual content analysis

This article suggests one way to systematically code textual data for research. The approach utilizes computer content analysis to examine patterns of emphasized ideas in text as well as the social context or underlying perspective reflected in the text. A conceptual dictionary is used to organize word meanings. An extensive profile of word meanings is used to characterize and discriminate social contexts. Social contexts are analyzed in relation to four reference dimensions (traditional, practical, emotional and analytic) which are used in the social science literature. The approach is illustrated with five widely varying texts, analyzed with selected comparative data. This approach has been useful in many social science investigations to system-atically score open-ended textual information. Scores can be incorporated into quantitative analysis with other data, used as a guide to qualitative studies, and to help integrate strengths of quantitative and qualitative approaches to research.     

Design matrix analysis

Analysts of social mobility are coming round to the view that it is not enough to find a model that fits the data; it is at least as important to know which bits of the model fit the data, and which are unimportant. The need for this type ofstructuring becomes even more pressing when we seek to determine the dimensions along which societies differ. This paper carries the process of structuring a stage further by proposing an orthogonal decomposition of a mobility model in which each dimension (degree of freedom) can be given a distinct sociological interpretation. In the following paper orthogonal rotation is deployed to uncover the latent dimensions of a mobility table. Relations among different models are established. The paper closes with a response to criticisms published by Sobel (1983).     

Strategic job analysis

The application of job analysis techniques makes the implicit assumption that information about a job as it presently exists may be used to develop programs to recruit, select, train, and appraise people for the job as it will exist in the future. Given a rapidly changing internal and external world it is likely that many jobs will change in the future. This article reviews some new techniques that, when added to traditional job analysis procedures, may facilitate strategic planning for the development of personnel procedures such as selection and training. Examples of the new technique are presented, followed by a discussion of some topics requiring future thought and research.     

Compensation plan analysis

Determining what share of the company's financial resources is used for compensation programs can be done through various mathematical processes. Some of the basic equations are discussed and examples are included in this article.     

Laying the groundwork-an analysis of how to get started with operations analysis

To make operations analysis a pervasive force in education, it is as important to be systematic and disciplined in deciding which projects to undertake as it does to show these virtues once we have selected a problem and are pressing for a solution. Progress means thinking about objectives, including the objective of demonstrating that operations analysis is relevant for education and of establishing a climate of acceptance for the new methods. Progress means concern for people and politics and an eye for initial projects that are hard to bungle. We have little to gain in pitting scarce talent and betting the reputation of operations analysis on situations which we can do little to improve. Meaningful solutions, for the administrator, are solutions that he can manage politically and that do not require impossible increases in staff or budgets to implement. Shrewdness in choosing projects that fit what we can do with operations analysis, though, does not mean picking insignificant problems. Operations analysis must understand the larger issues in American education and set its priorities to fit. We can better afford honest failure than irrelevance.     

Mining cost analysis and cost control based on the sensitivity factor analysis

This paper systematically generalizes relevant theories and methods regarding mining cost control and constitutes the model for the mining cost analysis. It also comes up with the sensitivity factor analysis to conduct mining cost control. The theories and methods have been experimented with Jiangsu Chuanshan Mining Joint-Stock Company Ltd. Case studies have been undertaken on mining cost of the company and the most sensitive factor which affects mining cost has been found accordingly. Finally the paper concludes that the focus concerning the cost control of the company should be directed at output and material costs.