An item-by-item subject classification of papers published in multidisciplinary and general journals using reference analysis

A serious shortcoming of bibliometric studies based on the(Social) Science (s) Citation Index is the lack of an universally applicable subject classification scheme as individual papers are concerned. 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 highly specialised journals, but fails for multidisciplinary journals such asNature, Science andPNAS—and so far as subfields are taken into consideration-also for “general” journals (e.g.JACS orAngewandte Chemie). This study presents the results of a pilot project attempting to overcome this shortcoming by delimiting the subject of papers published in multidisciplinary and general journals by an item-by-item subject classification scheme, where assignment is based on the analysis of the subject classification of reference literature. The results clearly confirmed the conclusions of earlier studies by the authors in the field of reference analysis. For the really important journals (sufficiently high number of annual publications and high impact with respect to the field), the share of classifiable papers was surprisingly high, and the assignment proved reliable as well. Since papers in the leading general and multidisciplinary journals are frequently citing general and multidisciplinary journals, an iterated application of the procedure is expected to increase the number of classifiable publications. The results of the new methodology may improve the validity of bibliometric studies for research evaluation purposes.     

Algorithmic identification of Ph.D. thesis-related publications: a proof-of-concept study

In this study we propose and evaluate a method to automatically identify the journal publications that are related to a Ph.D. thesis using bibliographical data of both items. We build a manually curated ground truth dataset from German cumulative doctoral theses that explicitly list the included publications, which we match with records in the Scopus database. We then test supervised classification methods on the task of identifying the correct associated publications among high numbers of potential candidates using features of the thesis and publication records. The results indicate that this approach results in good match quality in general and with the best results attained by the “random forest” classification algorithm.

     

Chladnis Beiträge zur Raumakustik

A lot of publications on the acoustics of theatres and churches were published around the turn of the 18th to the 19th century.The authors were architects who were interested in acoustical problems. Chladni was the first physicist who published on the acoustics of rooms, he introduced the term “reverberation” into this field. His publications on this subject are reviewed. They have been the basis for the great progress of room acoustics since 1900.

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Zum 250. Geburtstag des Gelehrten     

Classification of modulated signals using multifractal features

Abstract

In this paper we develop a novel modulation classification scheme based on multifractal dimensions. Theoretic analysis demonstrates that these features are robust to noise interference, and simulation results indicate the proposed scheme can classify modulated types accurately in a large range of SNR variation.     

Dynamic network analytics for recommending scientific collaborators

Collaboration is one of the most important contributors to scientific advancement and a crucial aspect of an academic’s career. However, the explosion in academic publications has, for some time, been making it more challenging to find suitable research partners. Recommendation approaches to help academics find potential collaborators are not new. However, the existing methods operate on static data, which can render many suggestions less useful or out of date. The approach presented in this paper simulates a dynamic network from static data to gain further insights into the changing research interests, activities and co-authorships of scholars in a field–all insights that can improve the quality of the recommendations produced. Following a detailed explanation of the entire framework, from data collection through to recommendation modelling, we provide a case study on the field of information science to demonstrate the reliability of the proposed method, and the results provide empirical insights to support decision-making in related stakeholders—e.g., scientific funding agencies, research institutions and individual researchers in the field.

     

Co-citation Percentile Rank and JYUcite: a new network-standardized output-level citation influence metric and its implementation using Dimensions API

Judging value of scholarly outputs quantitatively remains a difficult but unavoidable challenge. Most of the proposed solutions suffer from three fundamental shortcomings: they involve (i) the concept of journal, in one way or another, (ii) calculating arithmetic averages from extremely skewed distributions, and (iii) binning data by calendar year. Here, we introduce a new metric Co-citation Percentile Rank (CPR), that relates the current citation rate of the target output taken at resolution of days since first citable, to the distribution of current citation rates of outputs in its co-citation set, as its percentile rank in that set. We explore some of its properties with an example dataset of all scholarly outputs from University of Jyväskylä spanning multiple years and disciplines. We also demonstrate how CPR can be efficiently implemented with Dimensions database API, and provide a publicly available web resource JYUcite, allowing anyone to retrieve CPR value for any output that has a DOI and is indexed in the Dimensions database. Finally, we discuss how CPR remedies failures of the Relative Citation Ratio (RCR), and remaining issues in situations where CPR too could potentially lead to biased judgement of value.

     

Context analysis—A technique for analysing research in a field, applied to literature on the management of R&D at the section level

Context analysis is a new method for appraising a body of publications. The process consists of creating a database of attributes assigned to each paper by the reviewer and then looking for interesting relationships in the data. Assigning the attributes requires an understanding of the subject matter of the papers. We present findings about one particular research field, Management of R&D at the Section Level. Our findings support the view that this body of academic publications does not meet the needs of practitioner R&D managers. The paper discusses practical aspects of how to apply the method in other fields.     

Gender gaps in international research collaboration: a bibliometric approach

This paper addresses gender differences in international research collaboration measured through international co-authorship. The study is based on a dataset consisting of 5600 Norwegian researchers and their publication output during a 3-year period (44,000 publications). Two different indicators are calculated. First, the share of researchers that have been involved in international collaboration as measured by co-authorship, and second, the share of their publications with international co-authorship. The study shows that the field of research is by far the most important factor influencing the propensity to collaborate internationally. There are large differences from humanities on the one hand, where international collaboration in terms of co-authorship is less common, to the natural sciences on the other, where such collaboration is very frequent. On an overall level, we find distinct gender differences in international research collaboration in Norway in the favour of men. However, men and women are not equally distributed across fields and there are relatively more female researchers in fields where the international collaboration rates generally are lower. When the data are analysed by scientific field, academic position, and publication productivity of the researchers, the gender differences in the propensity to collaborate with colleagues in other countries are minor only, and not statistically significant. Concerning gender inequality in science, the main challenge seems to be the lower productivity level of female researchers, which obviously hinders their academic career development. Differences in international collaboration are unlikely to be an important factor in this respect, at least not in the Norwegian research context analysed in this study.

     

Source normalized indicators of citation impact: an overview of different approaches and an empirical comparison

Different scientific fields have different citation practices. Citation-based bibliometric indicators need to normalize for such differences between fields in order to allow for meaningful between-field comparisons of citation impact. Traditionally, normalization for field differences has usually been done based on a field classification system. In this approach, each publication belongs to one or more fields and the citation impact of a publication is calculated relative to the other publications in the same field. Recently, the idea of source normalization was introduced, which offers an alternative approach to normalize for field differences. In this approach, normalization is done by looking at the referencing behavior of citing publications or citing journals. In this paper, we provide an overview of a number of source normalization approaches and we empirically compare these approaches with a traditional normalization approach based on a field classification system. We also pay attention to the issue of the selection of the journals to be included in a normalization for field differences. Our analysis indicates a number of problems of the traditional classification-system-based normalization approach, suggesting that source normalization approaches may yield more accurate results.     

Optimizing the interaction of technical,social and organizational factors in work groups—an application of the multidimensional classification method

This paper suggests a new multidimensional classification method for finding design rules for work groups from the viewpoint of optimizing the interaction of technical, social and organizational factors in work groups. It is called the contingent multidimensional classification method (CMDC)

For classifying tasks, the CMDC evaluates three kinds of similarities.

(1)Similarity in the attributes of tasks.

(2)Similarity in the effects of tasks.

(3)Similarity in the attributes of worker and supervisors being assigned the tasks.

The effects are measured by such effectiveness indexes as job satisfaction or work performance.

Several design rules are needed to adapt to various situations, because there is no single best rule for designing effective work groups. The diverse design rules for determining interrelationships among constituent units of the work group—task, worker and supervisor—can be found by examining the properties of ‘similar task types’ resulting from classifying tasks by CMDC     

Double‐Wall Carbon Nanotubes: Classification and Barriers for Relative Motion of Walls

Abstract

The classification scheme for double‐wall carbon nanotubes (DWCNT) based on their symmetry is proposed. According to the scheme each DWCNT ascribe to families of DWCNT with the same geometrical parameters. The barriers for wall relative rotation, sliding along nanotube axis and helical line of “thread” and threshold forces cause the wall relative motion are calculated for set of DWCNT.     

Reply: On the evanescent field of dipole

Abstract

Recent controversy over the otherwise tuitional topic of separate contributions of evanescent and propagating waves in dipole radiation in free space has triggered a series of publications. I insisted on the use of changing plane-wave expansion for the decomposition, while other authors persisted on obtaining the field components with fixed plane-wave expansion.     

A new approach to defining a multidisciplinary field of science: The case of cardiovascular biology

This paper describes a new and objective method for tackling the problem of defining a multidisciplinary research area for bibliometric analysis. The test field was cardiovascular biology. A three stage process was adopted in setting a boundary around this research field:

1. Appropriate sections of a hierarchical subject classification scheme, Medical Subject Headings (MeSH), were developed into a “MeSH filter” through which papers indexed in MEDLINE were screened.
2. A panel of cardiovascular experts reviewed the core set of classification terms, identifying irrelevant and missing areas, facilitating the development of a more sophisticated “filter”.
3. The definition was validated using publication lists from research departments with a known interest in cardiovascular research.

This iterative process resulted in a definition of the field which captured basic and clinical research papers from the international biomedical research community and which was recognisable to experts in the field of cardiovascular research. Importantly, the field boundary also excluded publications which were not relevant to cardiovascular research. The process of involving experts in shaping the field definition also yielded two intangible, but key benefits: (a) it lent credibility to subsequent analyses, the results of which were to be presented to policy-makers in cardiovascular biology, and (b) it served to shape consensus among the cardiovascular experts on the full range of scientific disciplines that are relevant to their field. Analysis of international publishing in cardiovascular research revealed that whilst the UK and US dominate in total numbers of papers, the relative emphasis on cardiovascular research in these countries (as a proportion ofall biomedical publishing) is actually quite low, and declining. Japan and Germany in contrast appear to give greater emphasis to cardiovascular research in their national portfolios of biomedical science, and between 1988–1991 Japan established a marked increase in activity.     

A quantitative exploration on reasons for citing articles from the perspective of cited authors

Citation is regarded as one of the “norms of science” (Merton in Am Sociol Rev 22(6):635–659, 1957) and is deeply researched by the field of scientometrics. The motivations authors have for citing one another are considered significant and have been the subject of extensive qualitative research such as content analysis, questionnaires, and interviews of citing authors. However, the existing qualitative studies have covered a limited number of samples. To expand the dataset, this paper proposes a quantitative method applied to detecting citation reasons from the angle of citation networks and the attributes of cited authors, including their publication count (the number of single-authored publications, collaborative and first-authored publications as well as collaborative but non-first-authored publications, and number of whole publications), citation count, research topic interests, and gender. By applying the Exponential Random Graph Models (ERGMs), the current study revealed that authors in the field of information retrieval tend to cite those with more single-authored, collaborative and first-authored, and collaborative but not first-authored publications. Besides, in this field, the number of publications, similar topical domains, and same gender are proven to be significantly favorable in selecting references in our experiment.     

A new parameter for (normalized) evaluation of H-index: countries as a case study

It is known that the H-indexes of individuals, research groups, institutions, scientific journals, and countries strongly depend on the field of study, slowly increase with the number of publications, N, and can be described by empirical power-law functions of the type H?=?C?×?N^a (C and a are constants and depend on the specific field being analyzed). In this paper, we use this function and propose a new index [Montazerian–Zanotto–Eckert (MZE)], which is normalized by the number of publications and typically varies from ??1 to +?1, to characterize the relative standing of a research group, institution, or author to those of his/her peer groups. Due to the rich statistics available, as an example, here we analyzed and tested the new parameter against the citation-related performance (H-index) of countries. We found that the MZE index readily distinguishes between countries that stand above or below the average (for any given number of publications). Generally, publications of countries with a positive MZE index are more interesting or visible than the average. Analyzing publication output in this manner instead of the H-index allows for a less biased comparison between researchers, journals, universities, or countries for any particular combination of H-index and publication output.

     

Representing a scientific field: A bibliometric approach

A new bibliometric method is proposed for representing links between subfields as defined by a classification scheme. The frequency of co-occurrence of articles from different subfields in selected journals is used for measuring the degree of relatedness between these subfields. The results of such quantitative analysis could be compared to the tree topology of the classification network established in a qualitative analysis. The method is applied to describe the internal links within the field of condensed matter physics using the 1984 Physics Abstracts database. A distinction is made between experimental and theoretical links on the basis of treatment codes assigned to journal articles. The links described by cluster analysis are matched against the cross-reference network of the International Classification for Physics.     

A recursive field-normalized bibliometric performance indicator: an application to the field of library and information science

Two commonly used ideas in the development of citation-based research performance indicators are the idea of normalizing citation counts based on a field classification scheme and the idea of recursive citation weighing (like in PageRank-inspired indicators). We combine these two ideas in a single indicator, referred to as the recursive mean normalized citation score indicator, and we study the validity of this indicator. Our empirical analysis shows that the proposed indicator is highly sensitive to the field classification scheme that is used. The indicator also has a strong tendency to reinforce biases caused by the classification scheme. Based on these observations, we advise against the use of indicators in which the idea of normalization based on a field classification scheme and the idea of recursive citation weighing are combined.     

A method for assembly line balancing with more than one worker in each station

The typical assembly line is serial with no paralleling of work elements and work stations allowed. The series assumption restricts the least cycle time to be the maximum work element time, thus limiting the production rate.

An alternative way to increase the production rate (hence lowering the cycle time) is by assigning multiple workers to one work station. In this paper we propose the parallel assignment method (PAM) for achieving a higher production rate.

In the first phase of PAM the work elements are assigned to work stations under the multi-stage upper time limits. But as two or more workers are assigned to one station, the operation time of each worker is longer in proportion to the number of workers at the station.

Therefore, in the second phase of PAM work elements are assigned to the workers in each station so that each of the workers may perform shorter work elements where the work element is a minimum rational indivisible work item.

Practical problems which cannot he solved by serial line balancing methods are provided and.solved to explain the effectiveness of PAM.     

A hybrid scheme of signal process techniques to improve the measurement accuracy of antenna radiation patterns inside an anechoic chamber

Abstract

Antenna measurement inside an anechoic chamber can significantly suffer from measurement inaccuracy due to the scattering from the shielding walls and internal structures, if the space is not sufficiently large and the absorbers have not significantly reduced the multipath signals, which raises multipath interference. This paper develops a hybrid scheme that integrates the concepts of signal processing techniques including time gating, matrix pencil and multiple signal classification methods to reduce the multipath effects and improve the measurement accuracy. Characteristic comparison between individual method as well as the hybrid scheme will be performed based on experimental examinations.     

Producing GHZ state of nitrogen-vacancy centers in cavity QED

Abstract

We propose a scheme to generate the GHZ state of nitrogen-vacancy centers coupled to a whispering-gallery mode cavity. The implemented evolution is independent of the cavity field state with the assistance of a strong classical field, and thus not sensitive to the thermal state of the cavity. Meanwhile, it is fast compared to the convectional dispersive interaction induced operation in a cavity-assisted system. The scheme is readily scalable to the multiqubit scenario.