Research output and transnational cooperation in physics subfields: A multidimensional analysis

This paper compares the profiles of research output and transnational cooperation (as revealed through multicountry publications) of thirty six countries in ten subfields of Physics during the period 1981–1985. The data for comparative analysis were taken fromBraun et al. Since raw counts of publications are confounded by the size of the countries and the size of the research fields, this comparison is made, using relative indicators — activity index and collaboration index. The structures of research output and transnational cooperation are analyzed through Correspondence Analysis, which leads to the identification of countries with similar profiles (of research output and transnational cooperation) and the spatial representation of countries and Physics subfields. The configurations of research output and transnational cooperation are compared to assess the concordance between the policies of these countries for research and transnational cooperation in Physics.     

Measuring knowledge transfer between fields of science

In this paper we report on the results of an exploratory study of knowledge exchange between disciplines and subfields of science, based on bibliometric methods. The goal of this analysis is twofold. Firstly, we consider knowledge exchange between disciplines at a global level, by analysing cross-disciplinary citations in journal articles, based on the world publication output in 1999. Among others a central position of the Basic Life Sciences within the Life Sciences and of Physics within the Exact Sciences is shown. Limitations of analyses of interdisciplinary impact at the journal level are discussed. A second topic is a discussion of measures which may be used to quantify the rate of knowledge transfer between fields and the importance of work in a given field or for other disciplines. Two measures are applied, which appear to be proper indicators of impact of research on other fields. These indicators of interdisciplinary impact may be applied at other institutional levels as well. This revised version was published online in August 2006 with corrections to the Cover Date.     

Web Impact Factors for Australasian universities

In this paper we report on the results of an exploratory study of knowledge exchange between disciplines and subfields of science, based on bibliometric methods. The goal of this analysis is twofold. Firstly, we consider knowledge exchange between disciplines at a global level, by analysing cross-disciplinary citations in journal articles, based on the world publication output in 1999. Among others a central position of the Basic Life Sciences within the Life Sciences and of Physics within the Exact Sciences is shown. Limitations of analyses of interdisciplinary impact at the journal level are discussed. A second topic is a discussion of measures which may be used to quantify the rate of knowledge transfer between fields and the importance of work in a given field or for other disciplines. Two measures are applied, which appear to be proper indicators of impact of research on other fields. These indicators of interdisciplinary impact may be applied at other institutional levels as well. This revised version was published online in August 2006 with corrections to the Cover Date.     

Modelling and measuring multilateral co-authorship in international scientific collaboration. Part II. A comparative study on the extent and change of international scientific collaboration links

The present study is focused on international collaboration in science, involving more than two countries. The authors developed a promising model to measure and analyse the extent of multilateral co-authorship links in a previous study. The model is based on a series expansion approach which relates a new indicator, the Multilateral Collaboration Index (ρ), to the share of internationally co-authored papers (f). The model was found suitable to classify both the share of international papers, as well as the extent of multilateral links through the deviations from their expectations. A comparative analysis is made of changing collaboration patterns between 1983 and 1993 for 8 selected subfields, as well as all fields combined of the most active 38 countries. As expected an intensification of international scientific collaboration was observed, especially for a number of former COMECON countries. Different types of behaviour for different countries and science subfields emerged.     

Citation lag analysis in supply chain research

Interdisciplinary research is expected to contribute to industrial and economic development. However, due to expansion of knowledge and the fragmentation of research fields, knowledge dissemination among different research fields is rare and we need a methodology for measuring such dissemination and promoting it. In this paper, we introduce a citation lag analysis of inter- and intra-clusters extracted by citation network analysis as a new indicator to represent the speed of knowledge diffusion in subfields of a research field. A case study was performed within supply chain research to investigate knowledge integration among its subfields. Based on the analysis, we discuss knowledge structure and reciprocal influence of subfields in supply chain research. This study contributes to offering a new approach for analyzing and understanding the development of boundary spanning research.     

Measuring national output in physics: Delimitation problems

In a study of the Dutch publication output in physics we tested methods of delimitating fields by journal categories in theScience Citation Index (SCI) compared to the classification of individual publications into subfields in the subject specific databasePhysics Briefs (PHYS). Different methods of measuring national scientific output were compared as well. In this paper we report the main findings on these issues, based on a study of six selected subfields in physics. The main conclusion with respect to the use of different classification methods is that in most of the selected fields in physics the method which delimitates fields by journal categories yields an incomplete picture of the output of a country. Particularly because this method neglects a considerable number of articles published in general journals. With respect to different methods of counting publications it was corroborated by the Dutch data inPhysics Briefs that: 1. so-called integer counted world shares are very much influenced by the degree of internationalisation and 2. first author counting gives a satisfactory approximation of fractional counting. Citation indicators based on first author counting, however, may be distorted in fields with a large fraction of international co-authored publications.     

Delimitation of scientific subfields using cognitive words from corporate addresses in scientific publications

An appropriate delimitation of scientific subfields constitutes one of the key problems in bibliometrics. Several methods have been explored for this task. The main ones are co-citation analysis, co-word analysis, the use of indexing systems based on controlled or uncontrolled keywords, and finally the use of a classification of scientific journals into subfields or categories. In our contribution we will explore a new method, which is based on cognitive words from addresses (corporate sources) in scientific publications. Cognitive address words are words referring to scientific (sub)fields, methods or objects of research, that appear in the institutional affiliations of the publishing authors (e.g., Department of Pharmacology, AIDS Research Center). We will focus on theScience Citation Index (SCI), published by the Institute for Scientific Information. Our methods will be applied to a multidisciplinary set of articles extracted from the journalsScience andNature.     

A new methodological approach to bibliographic coupling and its application to the national,regional and institutional level

In an earlier study the authors have shown that bibliographic coupling techniques can be used to identify hot research topics. The methodology is based on appropriate thresholds for both number of related documentsand the strength of bibliographic links. Those papers are calledcore documents that have more than 9 links of at least the strength 0.25 according toSalton's measure, provided they are articles, notes or reviews. This choice resulted in a selection of nearly one per cent of all papers of the above types recorded in the 1992 annual cumulation of the SCI.Core documents proved important nodes in the network of documented science communication.In the present study, the set ofcore documents is analysed by journals, subfields and corporate addresses. The latter analysis is conducted on both national and regional-institutional level. First all countries which have published at least 20 core documents in 1992 are investigated in terms of their research profiles, their international collaboration patterns and their citation impact. Finally, those eight members of the European Union which have published at least 20 core documents in 1992 are analysed in respect of regional and institutional distribution of core documents.     

Structure and evolution of Indian physics co-authorship networks

We trace the evolution of Indian physics community from 1919 to 2013 by analyzing the co-authorship network constructed from papers published by authors in India in American Physical Society (APS) journals. We make inferences on India’s contribution to different branches of Physics and identify the most influential Indian physicists at different time periods. The relative contribution of India to global physics publication (research) and its variation across subfields of physics is assessed. We extract the changing collaboration pattern of authors between Indian physicists through various network measures. We study the evolution of Indian physics communities and trace the mean life and stationarity of communities by size in different APS journals. We map the transition of authors between communities of different sizes from 1970 to 2013, capturing their birth, growth, merger and collapse. We find that Indian–Foreign collaborations are increasing at a faster pace compared to the Indian–Indian. We observe that the degree distribution of Indian collaboration networks follows the power law, with distinct patterns between Physical Review A, B and E, and high energy physics journals Physical Review C and D, and Physical Review Letters. In almost every measure, we observe strong structural differences between low-energy and high-energy physics journals.

     

Bibliographic coupling,common abstract stems and clustering: A comparison of two document-document similarity approaches in the context of science mapping

This paper deals with two document-document similarity approaches in the context of science mapping: bibliographic coupling and a text approach based on the number of common abstract stems. We used 43 articles, published in the journal Information Retrieval, as test articles. An information retrieval expert performed a classification of these articles. We used the cosine measure for normalization, and the complete linkage method was used for clustering the articles. A number of articles pairs were ranked (1) according to descending normalized coupling strength, and (2) according to descending normalized frequency of common abstract stems. The degree of agreement between the two obtained rankings was low, as measured by Kendall’s tau. The agreement between the two cluster solutions, one for each approach, was fairly low, according to the adjusted Rand index. However, there were examples of perfect agreement between the coupling solution and the stems solution. The classification generated by the expert contained larger groups compared to the coupling and stems solutions, and the agreement between the two solutions and the classification was not high. According to the adjusted Rand index, though, the stems solution was a better approximation of the classification than the coupling solution. With respect to cluster quality, the overall Silhouette value was slightly higher for the stems solution. Examples of homogeneous cluster structures, as well as negative Silhouette values, were found with regard to both solutions. The expert classification indicates that the field of information retrieval, as represented by one volume of articles published in Information Retrieval, is fairly heterogeneous regarding research themes, since the classification is associated with 15 themes. The complete linkage method, in combination with the upper tail rule, gave rise to a fairly good approximation of the classification with respect to the number of identified groups, especially in case of the stems approach.     

Patents cited in the scientific literature: An exploratory study of 'reverse' citation relations

This paper reports on a new approach to study the linkage between science and technology. Unlike most contributions to this area we do not trace citations of scientific literature in patents but explore citations of patents in scientific literature. Our analysis is based on papers recorded in the 1996-2000 annual volumes of the CD-Edition of Science Citation Index (SCI) of the Institute for Scientific Information (ISI) and patent data provided by the US Patent and Trademark Office. Almost 30,000 US patents were cited by scientific research papers. We analysed the citation links by scientific fields and technological sectors. Chemistry-related subfields tended to cite patents more than other scientific area. Among technological sectors, chemical clearly dominates followed by drugs and medical patents as the most frequently cited categories. Further analyses included a country-ranking based on inventor-addresses of the cited patents, a more detailed inspection of the ten most cited patents, and an analysis of class-field transfers. The paper concludes with the suggestions for future research. One of them is to compare our 'reverse' citation data with 'regular' patent citation data within the same classification system to see whether citations occur, irrespectively of their directionality, in the same fields of science and technology. Another question is as to how one should interpret reverse citation linkages.     

New bibliometric tools for the assessment of national research performance: Database description,overview of indicators and first applications

This paper gives an outline of a new bibliometric database based upon all articles published by authors from the Netherlands, and processed during the time period 1980–1993 by the Institute for Scientific Information (ISI) for theScience Citation Index (SCI),Social Science Citation Index (SSCI) andArts & Humanities Citation Index (A&HCI). The paper describes various types of information added to the database: data on articles citing the Dutch publications; detailed citation data on ISI journals and subfields; and a classification system of publishing main organizations, appearing in the addresses. Moreover, an overview is given of the types of bibliometric indicators that were constructed. Their relationship to indicators developed by other researchers in the field is discussed. Finally, two applications are given in order to illustrate the potentials of the database and of the bibliometric indicators derived from it. The first represents a synthesis of ‘classical’ macro indicator studies at the one hand, and bibliometric analyses of research groups or institutes at the other. The second application gives for the first time a detailed analysis of a country's publication output per institutional sector.     

Redistributed random sampling method for categorizing materials research publications from SCI database: Metallurgy and polymer subfields

This article introduced two sampling methods, including Directly Random Sampling (DRS) and Redistributed Random Sampling (RRS) methods for categorization of a large number of research articles retrieved from metallurgy and polymer subfields from the Science Citation Index (SCI) database. The accuracy of the proposed sampling methods was considered in association by comparing with reference results previously obtained by Fully Retrieving Sampling (FRS) method, which involved analyzing the contents and categories of all articles from the database. The results suggested that RRS and DRS methods were appropriate, efficient and reasonably accurate for categorization of relatively large volume of research articles. RRS method was highly recommended, especially when the contents of sample articles was unevenly distributed. By DRS and RRS methods, only about 6.3% of total articles were required for obtaining similar results as those given by FRS method. The percentage Expected Worst Errors (EWE) from DRS and RRS methods were observed to range from 1.0 to 5.5%. The EWE value could be reduced by increasing the sample size.     

Distribution of physics literature

Percentage distributions of physics papers in 36 countries over ten subfields are compared. Factor and cluster analyses are applied to data from 1978Physics Abstracts. Countries load highly on seven factors. Their meaning is estimated by factor scores. Clusters of countries with similar publishing patterns are presented in a tree diagram.     

An item-by-item subject classification of papers published in journals covered by the SSCI database using reference analysis

A serious shortcoming of bibliometric studies based on theSocial Sciences Citation Index is the lack of a universally applicable subject classification scheme as individual papers are concerned. Moreover, the selective coverage of more than thousand scientific journals per annum proved to be an insuperable obstacle in the delimitation of social science subject areas. Subject classification of papers on the basis of assigning journals to subject categories (like those found in the various supplements of ISI databases) works well in case of fully covered and highly specialised journals in the social sciences, too, but fails for multidisciplinary and selectively covered journals. This study presents the results of an item-by-item subject classification approach, where assignment is based on the analysis of the subject categories of reference literature. This analysis extends the results of an earlier study by the authors on the possibility of delimiting subfields in the hard and life sciences based on reference analysis. The assignment proved also reliable for a considerable share of literature in the social sciences. Due to the peculiarities of the database this share is lower in the SSCI than that in the SCI. Although an iterated application of the procedure is expected to increase the number of classifiable publications, it is suggested that in the sociated sciences the method should be used in combination with other means of subject assignment.     

Mapping a research area at the micro level using co-word analysis

The present study investigates the use of co-word analysis method to understand the micro structure of a research speciality. This study is done in the area of Condensed Matter Physics (CMP) taking two time-periods, 1990 and 1995. Based on concurrent set of journals occurring in the subject heading list of CMP in these two time-periods, a database is created after downloading articles present in these journals from the INSPEC database. Using words extracted from the titles from the created database, suitable co-word pairs are constructed. These words, and co-word pairs are explored further to understand their linkages with each other through network analysis methods. Dynamics, within the CMP across 1990 and 1995, are investigated through the comparison of the words, co-word pairs and structurally equivalent blocks. The results are projected using multi-dimensional scaling. The important conclusions of this study are discussed.     

Recovering the Architecture of Links in a Chain of Three Unidirectionally Coupled Systems Using the Granger-Causality Test

Technical Physics Letters - We propose a method for reconstructing links in a chain of unidirectionally coupled systems by means of three tests for estimating direct and mediated coupling with the...     

Categorization and trend of materials science research from Science Citation Index (SCI) database: A case study of ceramics,metallurgy, and polymer subfields

This article offers information on the characteristics and number of materials research articles indexed in the Science Citation Index (SCI) database in the year of 2004. 22,843 articles in full-text forms from 169 journals from the materials field (which included ceramics, metallurgy, and polymer journals) were retrieved from the SCI database and exported to EndNote software. The retrieved articles were carefully analyzed by eight scientists and experts in those subfields and categorized using SPSS into eight different categories, being (1) New materials, (2) Materials characterizations, (3) Materials improvement, (4) New process and/or process improvement, (5) Mathematical and theoretical models and/or computer simulations, (6) Novel and comprehensive explanations, (7) Testing conditions, and (8) Comparative studies, whose definitions were clearly indicated. The results were then considered in terms of the percentage of the number of articles in each materials subfield, country of corresponding author, and number of authors. The overall results suggested that, most materials articles published in 2004 were focused on new process and process improvement (27%), while materials characterizations (23%) and testing conditions (12%) took the 2nd and 3rd places, especially for the ceramics and polymer articles. The highest numbers of articles in the ceramics and polymer subfields were focused on new processes and/or process improvement, and those for the metallurgy subfield were on materials characterization. In the SCI database, the largest number of materials articles was authored from Asian scientists although the majority of the materials journals were run by editors from Europe in North America/Canada continents. There was no coherent relationship between the authors’ and editors’ affiliations. China, Japan and the United States of America (USA) were shown to be the top three countries which had the highest publication numbers in the materials field. Japan had the highest publication numbers in the ceramics subfield while China possessed most publications in polymer and metallurgy subfields. However, when considering the journal impact factors, the leading positions of the countries changed. The results from this work could assist materials scientists to select suitable international journals in relevant association with the contents of their to-publish works. Finally, it was noted that most material research articles were written by 3–4 authorships.     

Analysis of the scientific productivity of researchers from the Republic of Croatia for the period 1990–1992

The scientific production of researchers from the Republic of Croatia, consisting of the published papers with addresses of the institutions from Croatia only, was analyzed for the period 1990–1992, covering 2047SCI, SSCI, andA&HCI registered papers. The source index ofSCI has registered 1912 (92.50% of total number of published articles) papers,SSCI 118 (5,71%), andA&HCI 37 (1.79%) papers, respectively. The papers were published in more than 700 different journals, covering 122 scientific subfields. The most frequently used journals are the nationalPeriodicum Biologorum, Croatica Chemica Acta andCollegium Antropologicum with 236 published papers or 11.5%. The largest number of papers have been published in scientific subfields:Biology (146 papers),Chemistry (107), andPhysics of Condensed Matter (102). The average paper was published by 3.57 researchers, but subfields ofNuclear Physics (7.40 authors per paper),Immunology (5.67), andHematology (5.60) were with the highest authorship. The partial contributions of institutions were also determined, and the most productive were Ruder Bokovi Institute with 645.0, the Faculty of Medicine with 396.7, and the Faculty of Science and Mathematics with 201.7 published papers, respectively. The average quality of the used journals were estimated; Institute of Physics, Ruder Bokovi Institute, and the Faculty of Science and Mathematics published their papers in journals with bigger impact factor (higher quality) than average institutions. Publications were divided by the type of papers, most frequent being articles (1778 publications, 86.85%), notes (117, 5.71%) and letters (56, 2.74%), respectively. Scientific subfield distribution of papers published by the most productive institutions were also analyzed.