Strong similarity measures for ordered sets of documents in information retrieval

A general method is presented to construct ordered similarity measures (OS-measures), i.e., similarity measures for ordered sets of documents (as, e.g., being the result of an IR-process), based on classical, well-known similarity measures for ordinary sets (measures such as Jaccard, Dice, Cosine or overlap measures). To this extent, we first present a review of these measures and their relationships.The method given here to construct OS-measures extends the one given by Michel in a previous paper so that it becomes applicable on any pair of ordered sets. Concrete expressions of this method, applied to the classical similarity measures, are given.Some of these measures are then tested in the IR-system Profil-Doc. The engine SPIRIT^© extracts ranked document sets in three different contexts, each for 550 requests. The practical usability of the OS-measures is then discussed based on these experiments.     

考虑地下水渗流特性的尾矿坝稳定性分析

选取合适的坝体断面,对某尾矿坝进行的二维渗流有限元分析,并考虑渗流特征进行坝体圆弧整体稳定性分析,得到相应的浸润线和坝体稳定性安全系数,对坝体的稳定性进行评价,该方法对类似尾矿坝工程的稳定性分析和设计具有重要的参考价值和指导意义。     

变质物品且考虑成本费用时值的经济制造批量模型

考虑变质物品在有现货和仓库出空阶段生产率不相同以及成本费用时值对库存管理的影响,建立了相应的库存控制模型。运用5.0版数学软件进行仿真寻优,得到系统唯一最优解。灵敏度分析表明,物品变质率、成本费用贴现率、生产率以及短缺量拖后因子对最优生产周期个数、每周期最优缺货时间与生产批量,以及库存系统各项成本等有不同程度的影响,在进行库存决策时必须考虑这些参数,并及时调整生产周期个数和每周期缺货时间。     

A comparison of collocation-based similarity measures in query expansion

In this paper, we present a comparison of collocation-based similarity measures: Jaccard, Dice and Cosine similarity measures for the proper selection of additional search terms in query expansion. In addition, we consider two more similarity measures: average conditional probability (ACP) and normalized mutual information (NMI). ACP is the mean value of two conditional probabilities between a query term and an additional search term. NMI is a normalized value of the two terms' mutual information. All these similarity measures are the functions of any two terms' frequencies and the collocation frequency, but are different in the methods of measurement. The selected measure changes the order of additional search terms and their weights, hence has a strong influence on the retrieval performance. In our experiments of query expansion using these five similarity measures, the additional search terms of Jaccard, Dice and Cosine similarity measures include more frequent terms with lower similarity values than ACP or NMI. In overall assessments of query expansion, the Jaccard, Dice and Cosine similarity measures are better than ACP and NMI in terms of retrieval effectiveness, whereas, NMI and ACP are better in terms of execution efficiency.     

我国管理咨询业发展对策的研究

管理咨询业是一个新兴的行业，它的发展是社会经济发展的需要。这一点从西方发达国家发展历程就可见一斑。20世纪80年代管理咨询业进入中国，在中国这块有着特殊文化背景和国情的土地上以自己独有的特色向前发展着。通过对中国管理咨询行业存在的问题进行了分析，提出了中国管理咨询行业发展的对策。     

The measures precision,recall, fallout and miss as a function of the number of retrieved documents and their mutual interrelations

In this paper, for the first time, we present global curves for the measures precision, recall, fallout and miss in function of the number of retrieved documents. Different curves apply for different retrieved systems, for which we give exact definitions in terms of a retrieval density function: perverse retrieval, perfect retrieval, random retrieval, normal retrieval, hereby extending results of Buckland and Gey and of Egghe in the following sense: mathematically more advanced methods yield a better insight into these curves, more types of retrieval are considered and, very importantly, the theory is developed for the “complete” set of measures: precision, recall, fallout and miss.     

Summarisation of the logical structure of XML documents

Summarisation is traditionally used to produce summaries of the textual contents of documents. In this paper, it is argued that summarisation methods can also be applied to the logical structure of XML documents. Structure summarisation selects the most important elements of the logical structure and ensures that the user’s attention is focused towards sections, subsections, etc. that are believed to be of particular interest. Structure summaries are shown to users as hierarchical tables of contents. This paper discusses methods for structure summarisation that use various features of XML elements in order to select document portions that a user’s attention should be focused to. An evaluation methodology for structure summarisation is also introduced and summarisation results using various summariser versions are presented and compared to one another. We show that data sets used in information retrieval evaluation can be used effectively in order to produce high quality (query independent) structure summaries. We also discuss the choice and effectiveness of particular summariser features with respect to several evaluation measures.     

Defining information: An analysis of the information content of documents

In order to characterize the information content of scientific documents an appropriate definition is developed which is based on the facts and data reported therein and on their conceptual interrelationship. The scope and limitations of such a definition are discussed and it is used to carry out the content analysis of a scientific paper and its abstract. The results of these analyses are represented in graphic form, evaluated and compared.     

Web形态下引文分析的科学指征研究——以10所医学院校数据为例

本研究从加菲尔德和普赖斯的思想出发,以《WebofScience》为数据源,通过学科评估得出的大量数据及计算机的分析处理,对文献的被引高峰及被引态势作了分析和验证,探讨了Web形态下的"累积被引曲线"和"被引频次分布曲线";与此同时,从研究得到的科学指征推出适合实际应用的"文献影响系数"及其初步算法。     

Methods for estimating the number of relevant documents in a collection

Several statistical sampling methods are evaluated for estimating the total number of relevant documents in a collection for a given query. The total number of relevant documents is needed in order to compute recall values for use in evaluating document retrieval systems. The simplest method considered uses simple random sampling to estimate the number of relevant documents. Another type of random sampling, which assigns unequal selection probabilities to the individual documents in the collection, is also investigated. An alternative approach considered uses curve fitting and extrapolation, where a smooth curve is developed which relates precision to document rank. Another curve relates a function of precision to the query-document score. In either case, the curve is extrapolated to the total number of documents in order to estimate the number of relevant documents. Empirical comparisons are made of all three methods.     

基于多层次分析的知识型员工创新绩效研究 —考虑个人与组织双层面因素的影响

基于创新管理相关理论,提出了知识型员工创新绩效概念模型。该模型涵盖了个人与组织两个层面。在个人层面,模型描述了创新意愿同创新绩效的正向关系,揭示了吸收能力的调节作用和知识扩散路径的中介作用;在组织层面,模型阐释了创新氛围的调节作用。随后,通过对调查数据的多元线性回归和多层线性分析,验证了依据概念模型提出的假设。研究还发现,在吸收能力的不同阶段,知识扩散路径对创新绩效的促进作用存有差异。因此,对知识扩散路径的选择要同员工的知识吸收能力相匹配。     

A logical framework for the correction of spelling errors in electronic documents

We propose a method for the correction of spelling errors found in electronic documents which is derived from a logical analysis of the problem. Specifically, set-theoretical definitions are given for similarity relations which describe certain properties which character strings may have in common. These definitions are then directly encoded into a PROLOG program. The advantages and disadvantages of this method are discussed, and some suggestions for further research are made. A detailed literature review is offered in order to place this method in perspective.     

科技政策研究代表人物与核心文献可视化网络

 引文计量方法常被用来确定某一研究领域的代表人物与核心文献。以国际科学技术政策研究权威期刊《科研政策》（Research Policy）的全部引文数据作为样本,通过作者共被引分析与文献共被引分析,确定了国际科技政策研究领域的代表人物与核心文献;并在此基础上,利用信息可视化技术,绘制出科技政策研究领域代表人物与核心文献的可视化网络,为科技政策研究者提供重要参考。