An approach to interdisciplinarity through bibliometric indicators

Interdisciplinarity has become of increasing interest in science in the past few years. Thispaper is a case study in the area of Chemistry, in which a series of different bibliometric indicatorsfor measuring interdisciplinarity are presented. The following indicators are analysed: a) ISI multiclassificationof journals in categories, b) patterns of citations and references outside category andc) multi-assignation of documents in Chemical Abstracts sections. Convergence between thedifferent indicators is studied. Depending on the size of the unit analysed (area, category orjournal) the most appropriate indicators are determined.     

Mapping interdisciplinarity at the interfaces between the Science Citation Index and the Social Science Citation Index

The two Journal Citation Reports of the Science Citation Index 2004 and the Social Science Citation Index 2004 were combined in order to analyze and map journals and specialties at the edges and in the overlap between the two databases. For journals which belong to the overlap (e.g., Scientometrics), the merger mainly enriches our insight into the structure which can be obtained from the two databases separately; but in the case of scientific journals which are more marginal in either database, the combination can provide a new perspective on the position and function of these journals (e.g., Environment and Planning B — Planning and Design). The combined database additionally enables us to map citation environments in terms of the various specialties comprehensively. Using the vector-space model, visualizations are provided for specialties that are parts of the overlap (information science, science & technology studies). On the basis of the resulting visualizations, “betweenness” — a measure from social network analysis — is suggested as an indicator for measuring the interdisciplinarity of journals.     

A bibliometric approach to interdisciplinarity in Japanese rice research and technology development

Research and development of rice, a major crop, has been promoted on an interdisciplinary basis with the involvement of various research fields ranging from natural sciences to socioeconomics in Japan. This paper focuses on the structure of interdisciplinarity in Japanese rice research and technology development by analyzing the relationship among all relevant disciplines with the use of a compiled bibliography of Japanese rice research with 19,389 articles in 1,611 journals in the publishing years of 1990–2000. The relationship among the disciplines was characterized by the frequency distribution of articles among journals classified into 24 categories based on the law of scattering originally identified by Bradford (Engineering 13:785–786, 1934). The 24 journal categories ranked in decreasing order of productivity of articles were divided into 3 zones; the first nuclear zone with a smaller number of highly productive journal disciplines; the second zone with a large number of less productive disciplines; and the last zone with a larger number of the least productive disciplines, which characterized the structure of interdisciplinarity in Japanese rice research and technology development. Other aspects of the interdisciplinarity were further explored with reference to peripheral journals with a minimal number of papers on a certain subject, and the Groos droop phenomenon at the end of Bradford’s S-shape curve that is the region of the least productive journals with only one paper on a certain subject, by analyzing the frequency distribution of articles in journal categories.     

A structural topic model approach to scientific reorientation of economics and chemistry after German reunification

The detection of differences or similarities in large numbers of scientific publications is an open problem in scientometric research. In this paper we therefore develop and apply a machine learning approach based on structural topic modelling in combination with cosine similarity and a linear regression framework in order to identify differences in dissertation titles written at East and West German universities before and after German reunification. German reunification and its surrounding time period is used because it provides a structure with both minor and major differences in research topics that could be detected by our approach. Our dataset is based on dissertation titles in economics and business administration and chemistry from 1980 to 2010. We use university affiliation and year of the dissertation to train a structural topic model and then test the model on a set of unseen dissertation titles. Subsequently, we compare the resulting topic distribution of each title to every other title with cosine similarity. The cosine similarities and the regional and temporal origin of the dissertation titles they come from are then used in a linear regression approach. Our results on research topics in economics and business administration suggest substantial differences between East and West Germany before the reunification and a rapid conformation thereafter. In chemistry we observe minor differences between East and West before the reunification and a slightly increased similarity thereafter.

     

A new approach to design of digital measuring instruments

We consider a general classification of digital voltmeters that has predictive capabilities; this classification is used to show that measuring instruments using different conversion methods have the same algorithmic basis. Translated from Izmeritel’naya Tekhnika, No. 7, pp. 23–26, July, 1999     

A thermodynamic approach to selecting a number of clusters based on topic modeling

A thermodynamic approach has been applied to solving the problem of selecting the number of clusters/topics in topic modeling. The main principles of this approach are formulated and the behavior of topic models during temperature variations is studied. Using thermodynamic formalism, the existence of the entropy phase transition in topic models is shown and criteria for the choice of optimum number of clusters/ topics are determined.

     

国家自然科学基金材料领域经费投入区域集聚程度分析

基于国家自然科学基金材料领域项目库的数据,对我国在新材料领域内国家科研投入的地域分布及其变动情况进行了初步分析。主要结论为:(1)新材料领域国家科研投入在地域分布上呈现明显的不均衡态势;(2)新材料领域国家科研投入的地域分布不均衡态势近年来呈现逐步缓解态势;(3)新材料领域国家科研投入的地域分布不均衡的主要原因是各个地域科研力量分布、经济发展、产业发展的不均衡。     

Uniform approach to the construction of digital measuring instruments

Measurement Techniques -     

一种基于时序窗口的动态热点话题提取模型

针对新闻领域的专题组织进行了研究,提出了一种基于时序窗口的动态热点话题提取模型。该模型整合了热点话题的两个特点。一方面关注主题词在新闻文本中的广泛性,衡量标准为多频道播报特征项的频率综合,词频越高其广泛性越高;另一方面考虑新闻流主题词的突发性,表现为特定时间段内主题词出现频率显著异常于其它时间段。引入时序窗口进行上升和下降突发模式提取,并结合TF-DF作为主题词赋权值依据。实验结果表明,这种基于时序窗口的动态热点话题提取模型对新闻文本进行主题抽取具有很好的性能。     

A flexible approach for measuring author-level publishing performance

Scientometrics - We propose a framework to evaluate, in relative terms, author-level publishing performance. To that end we introduce the publishing performance index (PPI) and the publishing...     

A value-of-information based approach to simulation model refinement

Looped water distribution networks have traditionally been used in urban and industrial water supply. Nowadays, they are also being introduced in certain irrigation water distribution systems, such as in greenhouse horticultural systems. The design of looped networks is a much more complex problem than the design of branched ones, but their greater reliability can compensate for the increase in cost. Most articles found in the literature try to minimize the network investment cost, while other designing objectives are considered as constraints. This article introduces a multi-objective memetic algorithm that simultaneously optimizes the total investment cost, and also the reliability of the network in terms of total surplus power at the demand nodes. This memetic algorithm uses the Pareto-dominance concept to determine the quality of the solutions. The results obtained in two small water supply networks, and a large irrigation water supply network denote the good performance of the memetic algorithm here proposed in comparison with other well known meta-heuristics.     

A model for measuring the congestion in library shelves

A model for measuring the congestion in library shelves after j years (j∈ ℕ) is obtained by taking j-fold convolutions of the distributions that describe the yearly growth of literature (e.g., periodicals, books on a certain topic,…) From this one can estimate the expected number of critical points in the shelf, after j years. One can also calculate the probability that there will be m (m∈ ℕ) critical points after j years. The paper closes by examining two concrete cases.     

Semantic-enhanced topic evolution analysis: a combination of the dynamic topic model and word2vec

The combination of the topic model and the semantic method can help to discover the semantic distributions of topics and the changing characteristics of the semantic distributions, further providing a new perspective for the research of topic evolution. This study proposes a solution for quantifying the semantic distributions and the changing characteristics based on words in topic evolution through the Dynamic topic model (DTM) and the word2vec model. A dataset in the field of Library and information science (LIS) is utilized in the empirical study, and the topic-semantic probability distribution is derived. The evolving dynamics of the topics are constructed. The characteristics of evolving dynamics are used to explain the semantic distributions of topics in topic evolution. Then, the regularities of evolving dynamics are summarized to explain the changing characteristics of semantic distributions in topic evolution. Results show that no topic is distributed in a single semantic concept, and most topics correspond to various semantic concepts in LIS. The three kinds of topics in LIS are the convergent, diffusive, and stable topics. The discovery of different modes of topic evolution can further prove the development of the field. In addition, findings indicate that the popularity of topics and the characteristics of evolving dynamics of topics are irrelevant.

     

A mathematical model to approach the fracture process of overconsolidated clay

Some soil and most rock masses contained defects (joints, cracks, bedding planes, fissures in clay, etc.). Beyond the peak shear strength of a mass of soil or rock, the stress falls as the strain increases. In this paper, the plane strain problem with double edge-cracks under shear loads is analysed based on linear elastic fracture mechanics but with finite stress concentration concept. We assumed that the fissured clay is a kind of strain-softening material and the growth of slip surface is along the maximum shear stress plane. The growth of slip surfaces in the progressive failure is expressed by the shear loads and slip displacement curves, which are obtained under the crack tip opening displacement criteria (CTOD_c) or the energy release rate criteria (J_c). The residual slip displacements are also taken into account by cumulating the elastic ones.     

How to evaluate the degree of interdisciplinarity of an institution?

The Stirling index of the set of references of the corpus documents is widely used in the literature on interdisciplinary research and is defined as the integration score of the corpus under study. Such an indicator is relevant at the scale of a research institution, however, there is a gap between the integration scores of individual documents, and a global score computed on the whole set of references. The difference between the global index and the average of individual document indexes carries another relevant information about the corpus: it measures the diversity between the reference profiles of the corpus documents. It is, therefore, named between article index whereas the average of the individual article indexes is called within article index. The statistical properties of these two indexes as well as of the global index are derived from a general approximation method for distributions and lead to statistical tests which can be used to make meaningful comparisons between an institution indexes and benchmark values. The two dimensions of the global index provide a more acute information on the interdisciplinary practices of an institution researchers in a given research domain and is, therefore, likely to contribute to strategic and management issues.