Measuring the citation impact of research journals in clinical neurology: A structural equation modelling analysis

This study develops and tests an integrated conceptual model of journal evaluation from varying perspectives of citation analysis. The main objective is to obtain a more complete understanding of the external factors affecting journal citation impact; that is, a theoretical construct measured by a number of citation indicators. Structural equation modelling (SEM) with partial least squares (PLS) is used to test the conceptual model with empirical data from journals in clinical neurology. Interrelationships among journal citation impact and four external factors (journal characteristics, journal accessibility, journal visibility and journal internationality) have been successfully explored, and the conceptual model of journal evaluation has been examined. This revised version was published online in June 2006 with corrections to the Cover Date.     

Investigation of tribological and mechanical properties of metal bearings

Copper, aluminum and tin-lead based alloys are widely used as journal bearing materials in tribological applications. Bronze and brass are widely used as journal bearing materials for copper based alloys. Zamacs find applications as journal bearing materials for zinc based alloys, while duralumines are chosen as journal bearing materials for aluminum based alloys. In addition, white metals are widely used as journal bearing materials for tin-lead based alloys. These alloys ensure properties expected from journal bearings. In this study, tribological and mechanical properties of these journal bearings manufactured by metals were investigated. SAE 1050 steel shaft was used as counter abrader. Experiments were carried out in every 30 min for a total of 150 min by using radial journal bearing wear test rig.     

Properties of journal impact in relation to bibliometric research group performance indicators

In this paper we present a compilation of journal impact properties in relation to other bibliometric indicators as found in our earlier studies together with new results. We argue that journal impact, even calculated in a sufficiently advanced way, becomes important in evaluation practices based on bibliometric analysis only at an aggregate level. In the relation between average journal impact and actual citation impact of groups, the influence of research performance is substantial. Top-performance as well as lower performance groups publish in more or less the same range of journal impact values, but top-performance groups are, on average, more successful in the entire range of journal impact. We find that for the high field citation-density groups a larger size implies a lower average journal impact. For groups in the low field citation-density regions however a larger size implies a considerably higher average journal impact. Finally, we found that top-performance groups have relatively less self-citations than the lower performance groups and this fraction is decreasing with journal impact.     

Optimum design of aramid-phenolic/glass-phenolic composite journal bearings

Composite journal bearings are increasingly employed in large journal bearings for marine applications because composite materials can eliminate the seizure problem between the journal and the bearing during the start and stop periods of journals. Recently, aramid/glass reinforced phenolic composite journal bearings have been employed rather than the asbestos-phenolic composite bearings due to the health hazard of asbestos. In this work, the mechanical properties of aramid/glass reinforced phenolic composite were measured in order to analyze the stress on the journal bearing using the finite element (FE) method. The failure modes of the aramid/glass reinforced phenolic composite journal bearings were observed. The modified dimensions of aramid/glass reinforced phenolic composite journal bearings and the optimum interference fit amount were suggested using the FE-analysis results.     

Characteristics of journal impact factors: The effects of uncitedness and citation distribution on the understanding of journal impact factors

Summary In this study, journal impact factors play a central role. In addition to this important bibliometric indicator, which evolves around the average impact of a journal in a two-year timeframe, related aspects of journal impact measurement are studied. Aspects like the output volume, the percentage of publications not cited, and the citation frequency distribution within a set timeframe are researched, and put in perspective with the 'classical' journal Impact Factor. In this study it is shown that these aspects of journal impact measurement play a significant role, and are strongly inter-related. Especially the separation between journals on the basis of the differences in output volume seems to be relevant, as can be concluded from the different results in the analysis of journal impact factors, the degree of uncitedness, and the share of a journal its contents above or below the impact factor value.     

An improved method for analyzing square scientometric transaction matrices

Modeling the number of citations from one journal to another may be done by assuming independent contributions from the referencing journal and from the cited journal. Empirical and theoretical evidence, however, indicates that self-citations are different from interjournal citations. For this reason a model is proposed that separates the analysis of selfcitations from inter-citations. In addition, a model is proposed that adjusts the expected citation counts by the journal to journal similarity. Computational procedures for fitting coefficients of the models to the observed citation pattern are described along with a statistical method for evaluating the validity of the model.     

A quantitative analysis of determinants of non-citation using a panel data model

The term “non-citation factor” refers to the percentage of never-cited papers in a citation time window, a common phenomenon in the science world. Some scholars have qualitatively explored the reasons for not citing a publication, and quantitatively analyzed the mathematical functional relations between the “non-citation factor” and “impact factor of a journal.” This study simultaneously considers the mutual relations and closeness degree between the “non-citation factor” and different influencing factors from a novel perspective—that of using a more structuralized panel data model. The analysis revealed that the determinants, including “impact factor of journal,” “age of journal,” “average number of references per paper in journal,” and “issues of journal,” exerted an extremely small but positive influence (<?0.025) on the decline of “percentage of never-cited papers in the citation time window of publication year or 3 years.” That means the improvement of these determinants can decrease the percentage of never-cited papers. The “impact factor of the journal” always had the biggest positive influence, while the “average number of references per paper in journal” always had the smallest positive influence. In wider citation time windows of 3 or 6 years, two determinants—“number of publications in journal” and “amount of interdisciplinarity in journal”—began to exert a negative effect with a positive correlation coefficient on the decline of the “non-citation factor.” That means the improvement of these two determinants cannot decrease the value of the “non-citation factor,” even though they can increase its value. It is worth noting that the “impact factor of the journal” had a positive influence on the decline of the percentages of never-cited papers in the citation time window of publication year or 3 years, and began to play a negative role in the decline of percentage of never-cited papers in the citation time window of 6 years. Finally, three variables—“average number of authors per paper in journal,” “average number of references per paper in journal,” and “issues of journal”—no longer exerted an influence on the decline of percentages of never-cited papers in the citation time window of 6 years, while “age of journal” and “average number of pages per paper in journal” still made a positive contribution. Our findings could help research institutions, researchers, editors, and publishers understand the positively or negatively influential factors that lead to non-citation, thus improving the chance of papers being cited and having some academic influence.     

径向动压浮环轴承-转子系统多稳定区域研究

以径向动压浮环轴承为研究对象,针对轴颈、浮环建立统一的动力学方程,用Routh-Hurwitz准则给出单质量刚性对称浮环轴承-转子系统稳定性判据。用有限差分计算某高速径向动压浮环轴承刚度、阻尼系数,获得不同工况下系统稳定性曲线。结果表明,小偏心率下系统升速过程中呈现多个稳定区域,且随偏心率、内外膜半径间隙变化而变化。油膜温度变化亦会影响系统稳定性。为高速浮环轴承稳定性整体建模、分析提供借鉴。     

Studying the international diffusion of a national scientific journal

The purpose of this paper is to apply concepts of the diffusion of innovations research in thestudy of the international diffusion of a formerly national scientific journal, Annales ZoologiciFennici. The study was conducted using bibliometric methodology. The diffusion of the journalwas described through citations of the journal and through the development of the nationaldistribution of its contributors. The compatibility of the journal as well as the decrease ofcomplexity were found to have an influence on diffusion. Bibliometric methods were able torepresent the international diffusion of a scientific journal.     

The overlap of U.S. and Canadian patent literature with journal literature literature with journal literature

The paper describes a study of the overlap of Canadian and U.S. patent literature and journal literature. A random sample of 300 U.S. and 100 Canadian patents published in 1968 were examined. 6.0% of the U.S. patents and 11.0% of the Canadian patents also appeared in the journal literature. 6.1% of the chemical patents, 6.0% of the mechanical patents and 11.3 % of the electrical patents also appeared in the journal literature. The results confirm the need to search both the journal and the patent literature for comprehensive literature coverage.     

Towards appropriate indicators of journal impact

This paper reviews a range of studies conducted by the authors on indicators reflecting scholarly journal impact. A critical examination of the journal impact data in theJournal Citation Reports (JCR), published by the Institute for Scientific Information (ISI) has shown that the JCR impact factor is inaccurate and biased towards journals revealing a rapid maturing or decline in impact. In addition, it was found that the JCR cited half life is an inappropriate measure of decline of journal impact. More appropriate impact measures of scholarly journals are proposed. A new classification system is explored, describing both maturing and decline of journal impact as measured through citations. Suggestions for future research are made, analysing in more detail the distribution of citations among papers in a journal.     

The self-cited rate of scientific journals and the manipulation of their impact factors

Owing to some discussions about manipulating impact factor by requesting authors to increase their citations to the publication journal, we theoretically establish a mathematical expression of a relation between the journal self-citation rate and its impact factor by the single-factor method in this paper. Based on self-citation data of some journals in JCR and the observed relation between journal impact factor and the self-cited rate, we analyze the possibility that journal editors manipulate impact factors of their journals by raising the self-cited rate. Finally, we make some suggestions for supervising this crude way of active manipulating the impact factor.     

径向浮环动静压轴承稳定性研究

以径向浮环动静压轴承为研究对象,针对轴颈和浮环建立了统一的动力学方程,用Routh-Hurwitz准则推导了径向浮环轴承的稳定性判据。用有限元法计算了某结构高速径向浮环动静压轴承的刚度系数和阻尼系数,在此基础上得到了不同偏心率下的失稳转速。由计算结果可以看出,浮环轴承具有极佳的稳定性,且随着偏心率的增加,失稳转速迅速提高。文章在高速浮环轴承稳定性整体建模和分析方面有较大的参考意义。     

Quality is in the eye of the beholder? An evaluation of impact factors and perception of journal prestige in the UK

A number of proxy measures have been used as indicators of journal quality. The most recent and commonly employed are journal impact factors. These measures are somewhat controversial, although they are frequently referred to in establishing the impact of published journal articles. Within psychology, little is known about the relationship between the ‘objective’ impact factors of journals and the ‘subjective’ ratings of prestige and perceived publishing difficulty amongst academics. In order to address this, a cross-sectional web-based survey was conducted in the UK to investigate research activity and academics’ views of journals within three fields of psychology; cognitive, health and social. Impact factors for each journal were correlated with individual academic’s perceptions of prestige and publishing difficulty for each journal. A number of variables pertaining to the individual academic and their place of work were assessed as predictors of these correlation values, including age, gender, institution type, and a measure of departmental research activity. The implications of these findings are discussed in relation to perceptions of journal prestige and publishing difficulty, higher education in general and the assessment of research activity within academic institutions.     

A revised measure of standing of journals in stratified networks

A modified index of journal standing in a stratified journal to journal citation network is proposed. The original index, generated through an application of input-output analysis, is used as the first step of an iterative procedure that converges on the new index. This index, an eiginvector of the inverted matrix used in the input-output analysis, has improved validity and better distributional properties than the original index.     

What factors are associated with increasing co-authorship in the social sciences? A case study of Danish Economics and Political Science

We examine the relative strength of short-term citation counts, bibliometric measures such as journal impact factors, and journal rankings in terms of predicting long-run citations. Using a set of articles published in sixty of the highest reputation economics journals in 1994, we find that citations received over fairly short windows (between 1 and 2 years after publication) are much stronger predictors of long-run citation counts compared with journal impact factors or other journal rankings. Our results are robust to a series of robustness checks. These findings suggest department heads and tenure and promotion committees should place greater weight on short-term citations as opposed to article placement when making personnel decisions.     

Journal self-citation rates in ecological sciences

Impact factors are a widely accepted means for the assessment of journal quality. However, journal editors have possibilities to influence the impact factor of their journals, for example, by requesting authors to cite additional papers published recently in that journal thus increasing the self-citation rate. I calculated self-citation rates of journals ranked in the Journal Citation Reports of ISI in the subject category “Ecology” (n = 107). On average, self citation was responsible for 16.2 ± 1.3% (mean ± SE) of the impact factor in 2004. The self-citation rates decrease with increasing journal impact, but even high impact journals show large variation. Six journals suspected to request for additional citations showed high self-citation rates, which increased over the last seven years. To avoid further deliberate increases in self-citation rates, I suggest to take journal-specific self-citation rates into account for journal rankings.     

Open access in ethics research: an analysis of open access availability and author self-archiving behaviour in light of journal copyright restrictions

The current state of open access to journal publications within research areas belonging to the humanities has received relatively little research attention. This study provides a detailed mapping of the bibliometric state of open access to journal publications among ethicists, taking into account not only open access publishing in journals directly, but also where and in what form ethicists make their journal articles available elsewhere on the web. As part of the study 297 ethicists affiliated with top-ranking philosophy departments were identified and their journal publication information for the years 2010–2015 were recorded (1682 unique articles). The journal articles were then queried for through Google Scholar in order to establish open access status (web locations, document versions) of each publication record. Publication records belonging to the 20 most frequently used journal outlets (subset of 597 unique articles) were put under closer inspection with regards to alignment with publisher copyright restrictions as well as measuring unused potential to share articles. The results show that slightly over half of recent journal publications are available to read for free. PhilPapers and academic social networks (Academia.edu and ResearchGate) were found to be key platforms for research dissemination in ethics research. The representation of institutional repositories as providers of access was found to be weak, receiving the second lowest frequency rating among the eight discrete web location categories. Further, the study reveals that ethicists are at the same time prone to copyright infringement and undersharing their scholarly work.