Pyramidal classification based on incomplete dissimilarity data

Two algorithms for pyramidal classification — a generalization of hierarchical classification — are presented that can work with incomplete dissimilarity data. These approaches — a modification of the pyramidal ascending classification algorithm and a least squares based penalty method — are described and compared using two different types of complete dissimilarity data in which randomly chosen dissimilarities are assumed missing and the non-missing ones are subjected to random error. We also consider relationships between hierarchical classification and pyramidal classification solutions when both are based on incomplete dissimilarity data.     

Metric and Euclidean properties of dissimilarity coefficients

We assemble here properties of certain dissimilarity coefficients and are specially concerned with their metric and Euclidean status. No attempt is made to be exhaustive as far as coefficients are concerned, but certain mathematical results that we have found useful are presented and should help establish similar properties for other coefficients. The response to different types of data is investigated, leading to guidance on the choice of an appropriate coefficient.The authors wish to thank the referees, one of whom did a magnificent job in painstakingly checking the detailed algebra and detecting several slips.     

Comparing partitions

The problem of comparing two different partitions of a finite set of objects reappears continually in the clustering literature. We begin by reviewing a well-known measure of partition correspondence often attributed to Rand (1971), discuss the issue of correcting this index for chance, and note that a recent normalization strategy developed by Morey and Agresti (1984) and adopted by others (e.g., Miligan and Cooper 1985) is based on an incorrect assumption. Then, the general problem of comparing partitions is approached indirectly by assessing the congruence of two proximity matrices using a simple cross-product measure. They are generated from corresponding partitions using various scoring rules. Special cases derivable include traditionally familiar statistics and/or ones tailored to weight certain object pairs differentially. Finally, we propose a measure based on the comparison of object triples having the advantage of a probabilistic interpretation in addition to being corrected for chance (i.e., assuming a constant value under a reasonable null hypothesis) and bounded between ±1.William H.E. Day was Acting Editor for the reviewing of this paper. We are grateful to him, Ove Frank, Charles Lewis, Glenn W. Milligan, Ivo Molenaar, Stanley S. Wasserman, and anonymous referees for helpful suggestions. Lynn Bilger and Tom Sharpe provided competent technical assistance. Partial support of Phipps Arabie's participation in this research was provided by NSF Grant SES 8310866 and ONR Contract N00014-83-K-0733.     

A note on Cohen's profile similarity coefficientr c

Analytic procedures for classifying objects are commonly based on the product-moment correlation as a measure of object similarity. This statistic, however, generally does not represent an invariant index of similarity between two objects if they are measured along different bipolar variables where the direction of measurement for each variable is arbitrary. A computer simulation study compared Cohen's (1969) proposed solution to the problem, the invariant similarity coefficientr _c , with the mean product-moment correlation based on all possible changes in the measurement direction of individual variables within a profile of scores. The empirical observation thatr _c approaches the mean product-moment correlation with increases in the number of scores in the profiles was interpreted as encouragement for the use ofr _c in classification research. Some cautions regarding its application were noted.This research was supported by the Social Sciences and Humanities Research Council of Canada, Grant no. 410-83-0633, and by the University of Toronto.     

<Emphasis Type="Italic">k</Emphasis>-Adic Similarity Coefficients for Binary (Presence/Absence) Data

k-Adic formulations (for groups of objects of size k) of a variety of 2-adic similarity coefficients (for pairs of objects) for binary (presence/absence) data are presented. The formulations are not functions of 2-adic similarity coefficients. Instead, the main objective of the the paper is to present k-adic formulations that reflect certain basic characteristics of, and have a similar interpretation as, their 2-adic versions. Two major classes are distinguished. The first class is referred to as Bennani-Heiser similarity coefficients, which contains all coefficients that can be defined using just the matches, the number of attributes that are present and that are absent in k objects, and the total number of attributes. The coefficients in the second class can be formulated as functions of Dice’s association indices. The author thanks Willem Heiser and three anonymous reviewers for their helpful comments and valuable suggestions on earlier versions of this article.     

基于B/S高校科技成果转化信息系统分析设计

随着网络经济、市场经济的迅猛发展,传统的高校科技成果转化中介服务手段与先进的网络信息技术已形成了巨大反差,建设高校科技成果转化的信息化中介服务体系已具备条件.本文在分析国内网络业的现状、特征和发展趋势的基础上,提出一种基于网络高校科技成果转化系统的新思想,并进行了系统分析与设计.     

HNC理论框架下的军语概念体系研究

传统的军语研究建立在军事学、术语学、词汇学、社会语言学、认知语言学、修辞学等学科基础上,文章探讨基于HNC语义网络下军语表达形式的特点,力求通过建立一种新的模式使军事术语能用于自然语言的计算机处理,在此基础上可进一步推动军语辞书编纂、军语的机器翻译等研究。     

墨家生命伦理论略

墨家对于人性的基本观点是人性欲利,无称善恶。肯认人性欲利的现实性和客观性使墨家自然地走向功利论伦理立场。《墨经》中有关生与知的论述是对墨家人命观的精炼概括;墨家重生而不惧死的生死观是其功利论道德理性在生命领域的必然体现。在生态观上,墨家是典型的人类中心主义,其重点强调的是代际伦理,主张生死两利,追求代际利益的均衡。     

评加扎里《精巧机械装置的知识》

加扎里的《精巧机械装置的知识》一书在中世纪阿拉伯机械史研究中具有重要意义。书中叙述了六大类共50种他所设计的自动机械装置的制作方法和工作流程。在肯定本书对于机械装置制作工艺的严谨和详细描述以外,同时探讨阿拉伯自动机械设计风格中突出强调娱乐性的特点。     

"哥白尼革命"的另一种解读--从数学哲学的角度看

哥白尼革命和数学有着不可分割的联系.评介了库恩对哥白尼革命根源和性质的"纯数学解释".由于纯数学是由数学哲学思想决定和规划,所以,理解哥白尼革命有必要开启数学哲学的视野.在伯特思想的启发下,从数学哲学的角度分析了哥白尼革命的根源以及性质,提出了与库恩有本质不同的观点,为理解近代科学的数学性提供了一个有益的视角.     

实验科学:一种新的权力/知识分析

在科学发展进程中，科学是怎样成功地取得对事件的技术控制的呢？很显然关注理论再现的正统解释已受到来自各方面的批判。劳斯（Joseph Rouse）提出了一种新的解释。它专注于科学的技巧、实践和技术，认为后者是现代权力关系展开和起作用的场所。这种权力关系，不仅发生在实验室对微型世界的构造过程中，也常常表现为科学对实验室之外的日常生活和社会实践的政治影响。权力／知识形式贯穿自然科学之中。     

H.A.别尔嘉耶夫技术哲学思想初探

介绍了俄国宗教哲学家别尔嘉耶夫对技术和机器以及现代文明的基本看法。从马克思主义唯物史观的角度，指出他对技术内在矛盾、技术对人类自身发展的制约等所做分析的合理性，同时指出他为摆脱技术奴役所做尝试的不可行性。     

另眼看默顿科学社会学

在默顿科学社会学的发展过程中,马克思主义哲学不仅是其思想资源之一,而且充当了某种理论参照系的作用;同时,默顿科学社会学强调科学的自主存在和发展,对于马克思主义哲学强调科学依赖经济需要和物质生产的观点,既是一种"反调",也是一种有益的补充.默顿科学社会学关于科学制度的研究是开创性的.这种研究看到了马克思主义哲学没有看到的关于科学社会本性的许多内容,极大地丰富了马克思主义哲学的科学观.     

聚合碱式氯化高铝多元盐的汉/英名称探讨

结合聚合碱式氯化高铝多元盐是大分子量化合物的特点,从无机小分子量化合物汉/英名称的习惯表述规则入手,进而探讨无机大分子量化合物汉/英名称的“简约”表述原则:在小分子量化合物汉/英名称习惯表述规则的基础上,提出对大分子量化合物的“组分”采用“省略”“缩写”“归并”和“一一对应”的“简约”原则表述大分子量化合物的名称。     

生物学哲学:科学哲学的新视野

达尔文进化论是科学史上少数具有跨学科思想辐射力的伟大学说。本文在上世纪80年代兴起的生物学哲学的背景下考察其在拓展我们的科学现和深化我们关于科学发展的理解方面所提供的理论启示。     

知识论批判:一种教育哲学的反思

知识论不仅是近代哲学的中心问题,也是近现代教育的精神基础。知识论是近现代教育的理论,近现代教育则是知识论的实践。知识论的知性思维方式对近现代教育产生了弥散性影响,而教育世界的知识论化在本质上却是一种价值颠覆,即科学知识取得了对其他知识类型的优先性。知识论放逐了本真的心灵问题,这是近现代教育问题之根源。从教育哲学的角度反思与批判知识论,是对知识论批判的必要补充。     

范式论心理学史批判

本文以对心理学学科性质的思考为出发点,通过揭示范式的本质并讨论以之为基础的库恩的科学哲学思想对心理学的影响关系,批判性地考察了范式论心理学史的研究背景及其基本结论,并指出,范式论心理学史研究不能在任何实质的意义上增加我们对心理学及其历史的理解.在此背景中,作者倡导用心理学理论同一性范畴来把握心理学及其历史,并认为,心理学的存在依赖于它的理论同一性的确立;心理学的发展,是对它的理论同一性的展开;现实形态的心理学史,是心理学对它的理论同一性的不断寻求的过程.     

爱因斯坦科学哲学思想研究述评

许多科学家、哲学家和科学史家从不同的角度解读爱因斯坦的科学哲学思想,得出不同的结论。本文对比、分析了具有代表性的弗兰克、霍尔顿、法因以及霍华德等人的观点,认为研究者的哲学倾向在很大程度上影响了他们的科学史研究。要全面、正确地认识爱因斯坦的科学哲学思想,必须把他的科学哲学思想与科学研究、宗教情怀、同时代的哲学背景等多方面的因素综合起来进行考察。