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Abstract

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.

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Abstract

This study builds the interdisciplinary knowledge network of China, which is used to catch the knowledge exchange structure of disciplines, and investigates the evolution process from 1981 to 2010. A network analysis was performed to examine the special structure and we compare state of the networks in different periods to determine how the network has got such properties. The dataset are get from the reference relationship in literature on important Chinese academic journals from 1980 to 2010. The analytical results reveal the hidden network structure of interdisciplinary knowledge flows in China and demonstrate that the network is highly connected and has a homogeneous link structure and heterogeneous weight distribution. Through comparing of the network in three periods, that is 1981–1990, 1991–2000 and 2001–2010, we find that the special evolution process, which is limited by the number of nodes, play an important influence on interdisciplinary knowledge flows.

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Abstract

Here we show a longitudinal analysis of the overall prestige of first quartile journals during the period between 1999 and 2009, on the subject areas of Scopus. This longitudinal study allows us to analyse developmental trends over times in different subject areas with distinct citation and publication patterns. To this aim, we first introduce an axiomatic index of the overall prestige of journals with ranking score above a given threshold. Here we demonstrate that, between 1999 and 2009, there was high and increasing overall prestige of first quartile journals in only four areas of Scopus. Also, there was high and decreasing overall prestige of first quartile journals in five areas. Two subject areas showed high and oscillating overall prestige of first quartile journals. And there was low and increasing overall prestige in four areas, since the 1999.

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This paper investigates the role of homophily and focus constraint in shaping collaborative scientific research. First, homophily structures collaboration when scientists adhere to a norm of exclusivity in selecting similar partners at a higher rate than dissimilar ones. Two dimensions on which similarity between scientists can be assessed are their research specialties and status positions. Second, focus constraint shapes collaboration when connections among scientists depend on opportunities for social contact. Constraint comes in two forms, depending on whether it originates in institutional or geographic space. Institutional constraint refers to the tendency of scientists to select collaborators within rather than across institutional boundaries. Geographic constraint is the principle that, when collaborations span different institutions, they are more likely to involve scientists that are geographically co-located than dispersed. To study homophily and focus constraint, the paper will argue in favour of an idea of collaboration that moves beyond formal co-authorship to include also other forms of informal intellectual exchange that do not translate into the publication of joint work. A community-detection algorithm for formalising this perspective will be proposed and applied to the co-authorship network of the scientists that submitted to the 2001 Research Assessment Exercise in Business and Management in the UK. While results only partially support research-based homophily, they indicate that scientists use status positions for discriminating between potential partners by selecting collaborators from institutions with a rating similar to their own. Strong support is provided in favour of institutional and geographic constraints. Scientists tend to forge intra-institutional collaborations; yet, when they seek collaborators outside their own institutions, they tend to select those who are in geographic proximity. The implications of this analysis for tie creation in joint scientific endeavours are discussed.

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Abstract

This article seeks to examine the relationship between scientific output and knowledge economy index in 10 South East Asian countries (ASEAN). Using bibliometric data of the Institute of Scientific Information, we analyzed the number of scientific articles published in international peer-reviewed journals between 1991 and 2010 for Vietnam, Cambodia, Laos, Thailand, Myanmar, Malaysia, Indonesia, Brunei, the Philippines, and Singapore. During the 20-year period, scientists from the ASEAN countries have published 165,020 original articles in ISI indexed journals, which represents ∼0.5% of the world scientific output. Singapore led the region with the highest number of publications (accounting for 45% of the countries’ total publications), followed by Thailand (21%), Malaysia (16%), Vietnam (6%), Indonesia and the Philippines (5% each). The number of scientific articles from those countries has increased by 13% per year, with the rate of increase being highest in Thailand and Malaysia, and lowest in Indonesia and the Philippines. At the country level, the correlation between knowledge economy index and scientific output was 0.94. Based on the relationship between scientific output and knowledge economy, we identified 4 clusters of countries: Singapore as the first group; Thailand and Malaysia in the second group; Vietnam, Indonesia and the Philippines in the third group; and Cambodia, Laos, Myanmar and Brunei in the fourth group. These data suggested that there was a strong relationship between scientific research and the degree of “knowledgization” of economy.

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Abstract

Research activities and collaborations in nanoscale science and engineering have major implications for advancing technological frontiers in many fields including medicine, electronics, energy, and communication. The National Nanotechnology Initiative (NNI) promotes efforts to cultivate effective research and collaborations among nano scientists and engineers to accelerate the advancement of nanotechnology and its commercialization. As of August 2008, there have been over 800 products considered to benefit from nanotechnology directly or indirectly. However, today's accomplishments in nanotechnology cannot be transformed into commercial products without productive collaborations among experts from disparate research areas such as chemistry, physics, math, biology, engineering, manufacturing, environmental sciences, and social sciences. To study the patterns of collaboration, we build and analyze the collaboration network of scientists and engineers who conduct research in nanotechnology. We study the structure of information flow through citation network of papers authored by nano area scientists. We believe that the study of nano area co-author and paper citation networks improve our understanding of patterns and trends of the current research efforts in this field. We construct these networks based on the publication data collected for years ranging 1993 through 2008 from the scientific literature database “Web of Science”. We explore those networks to find out whether they follow power-law degree distributions and/or if they have a signature of hierarchy. We investigate the small-world characteristics and the existence of possible community structures in those networks. We estimate the statistical properties of the networks and interpret their significance with respect to the nano field.

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Abstract

The obsolescence and “durability” of scientific literature have been important elements of debate during many years, especially regarding the proper calculation of bibliometric indicators. The effects of “delayed recognition” on impact indicators have importance and are of interest not only to bibliometricians but also among research managers and scientists themselves. It has been suggested that the “Mendel syndrome” is a potential drawback when assessing individual researchers through impact measures. If publications from particular researchers need more time than “normal” to be properly acknowledged by their colleagues, the impact of these researchers may be underestimated with common citation windows. In this paper, we answer the question whether the bibliometric indicators for scientists can be significantly affected by the Mendel syndrome. Applying a methodology developed previously for the classification of papers according to their durability (Costas et al., J Am Soc Inf Sci Technol 61(8):1564–1581, ; J Am Soc Inf Sci Technol 61(2):329–339, ), the scientific production of 1,064 researchers working at the Spanish Council for Scientific Research (CSIC) in three different research areas has been analyzed. Cases of potential “Mendel syndrome” are rarely found among researchers and these cases do not significantly outperform the impact of researchers with a standard pattern of reception in their citations. The analysis of durability could be included as a parameter for the consideration of the citation windows used in the bibliometric analysis of individuals.

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Abstract

This paper presents an in depth study of an interesting analogy, recently proposed by Prathap (Scientometrics 87(3):515–524, ), between the evolution of thermodynamic and bibliometric systems. The goal is to highlight some weaknesses and clarify some “dark sides” in the conceptual framework of this analogy, discussing the formal validity and practical meaning of the concepts of Energy, Exergy and Entropy in bibliometrics. Specifically, this analogy highlights the following major criticalities: (1) the definitions of E and X are controversial, (2) the equivalence classes of E and X are questionable, (3) the parallel between the evolution of thermodynamic and bibliometric systems is forced, (4) X is a non-monotonic performance indicator, and (5) in bibliometrics the condition of “thermodynamic perfection” is questionable. Argument is supported by many analytical demonstrations and practical examples.

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Abstract

It has been shown that papers in stem cell research submitted from institutions in the USA are accepted faster than those submitted from elsewhere and that the cause might at least partly be some bias in the refereeing process. We investigate whether there is a similar difference in time scale for papers in astronomy, astrophysics, and cosmology and look briefly at some of the possible causes. We find a publication time lag of 3.8 days (out of a median time of 105 days) while in the stem cell case it is 24 days out of a median of 83 days. One of many possible causes is a difference in how useful the papers are to the community, and we will assess this in a second paper making use of citation analysis.

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Scientometrics
Authors: Katy Börner, Wolfgang Glänzel, Andrea Scharnhorst and Peter van den Besselaar
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Abstract

The influence of the National Research Foundation's (NRF) rating system on the productivity of the South African social science researchers is investigated scientometrically for the period from 1981 to 2006. Their output performance is mainly indicated by their research publications. Following international best practice in scientometrics as well as the behavioural reinforcement theory, we employed the “before/after control impact (BACI) method”, as well as the well known econometric breakpoint test as proposed by Chow. We use as control group the publications in the field of clinical medicine. The field is not supported by NRF and hence clinical medicine researchers are not affected by the evaluation and rating system. The findings show a positive impact of the NRF programme on the research outputs of social sciences researchers and the implementation of the programme has increased the relevant population of research articles by an average of 24.5% (during the first 5 years) over the expected number of publication without the programme. The results confirm the scientometric findings of other studies (e.g. that of Nederhof) that ratings promulgate research productivity.

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Scientometrics
Authors: N. Nikolic, J.-L. Baglinière, C. Rigaud, C. Gardes, M. L. Masquilier and C. Taverny

Abstract

The aim of this study was to explore the research trends and the evolution of publications covered on diadromous fish from 1970s to 2010. We conducted a bibliometric analysis on seven patrimonial species: Atlantic salmon (Salmo salar), Brown and Sea trout (Salmon trutta), Allis shad (Alosa alosa), Twaite shad (Alosa fallax), Eel (Anguilla Anguilla), Sea lamprey (Petromyzon marinus) and River lamprey (Lampetra fluviatilis). We used bibliometric techniques on the total number of research (articles, books, and conferences) in all country in function of main fields such as growth/age, reproduction, migration, habitat, aquaculture, diseases, diet, abundance, fisheries, climate change, toxicology, dams/fishways, genetics, taxonomy, modelling, resource management, and stocking. The results revealed a clear difference in the evolution of scientific studies by species and by countries. The analysis comparisons showed the intensity of certain topics by species with the emergence of new ones, the economic impact on sciences and the increased support of conservation plan management for certain species, such as salmon and lamprey in France. This study also emerged that French research is not always consistent with the international trend which suggests the dominance of management systems on scientific studies.

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Abstract

This study is based on the fact that the surnames of many Russian scientists have gender endings, with “a” denoting a female, so that the sex of most of them can be readily determined from the listing of authors in the Web of Science (WoS). A comparison was made between the proportion of females in 1985, 1995, and 2005, with a corresponding analysis of the major fields in which they worked, their propensity to co-author papers internationally (which often necessitates having the opportunity to travel to conferences abroad to meet possible colleagues), and their citation records. We found, as expected, that women had a higher presence in the biological sciences and a very low presence in engineering, mathematics, and physics. Their citation scores, on a fractionated basis, were lower than those for men in almost all fields and years, and were not explained by their writing of fewer reviews and papers in English (both of which lead to higher citations), or their lower amount of international collaboration in 1995 and 2005 after Russia had become a more open society.

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Abstract

Surnames have been used as a proxy in studies on health care for various ethnic groups and also applied to ascribe ethnicity in studies on the genetic structure of a population. The aim of this study was to use a surname-based bibliometric indicator to assess the representation of Jewish authors in US biomedical journals. The other aim was to test the hypothesis that the representation of Jewish authors in US biomedical journals corresponds to their representation among US Nobel Prize winners in Medicine, 1960–2009. From among articles published 1960–2009 in all journals covered by Medline (>5,000), and in the top 10 US biomedical journals we counted articles by authors from the following three groups: Kohenic–Levitic surnames, other common Jewish surnames, and the most frequent non-Jewish surnames in the USA. The frequency of a surname in the US population (1990 US Census) was used to calculate the expected number of scientific publications: the total number of published articles multiplied by a surname's frequency. The actual number of articles with that surname was also determined. The ratio of actual to expected number of articles was used as a measure of representation proportionality. It was found that the ratio of actual to expected number of articles in both Jewish groups is close to 10 among all (>5,000) journals, and close to 20 in the top 10 journals. The ratio of actual to expected numbers of Jewish Nobel Laureates in the USA is also close to 20. In conclusion, the representation of Jewish authors in top 10 US biomedical journals corresponds to the representation of Jewish Nobel Laureates among US laureates. We hypothesize that disproportional representation of Jewish scientists as authors in top biomedical journals and among Nobel Prize laureates in Medicine is mostly due to their overrepresentation as research participants, not because of the increased chances for reward for a Jewish researcher per se.

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Abstract

Agent-based simulation can model simple micro-level mechanisms capable of generating macro-level patterns, such as frequency distributions and network structures found in bibliometric data. Agent-based simulations of organisational learning have provided analogies for collective problem solving by boundedly rational agents employing heuristics. This paper brings these two areas together in one model of knowledge seeking through scientific publication. It describes a computer simulation in which academic papers are generated with authors, references, contents, and an extrinsic value, and must pass through peer review to become published. We demonstrate that the model can fit bibliometric data for a token journal, Research Policy. Different practices for generating authors and references produce different distributions of papers per author and citations per paper, including the scale-free distributions typical of cumulative advantage processes. We also demonstrate the model's ability to simulate collective learning or problem solving, for which we use Kauffman's NK fitness landscape. The model provides evidence that those practices leading to cumulative advantage in citations, that is, papers with many citations becoming even more cited, do not improve scientists’ ability to find good solutions to scientific problems, compared to those practices that ignore past citations. By contrast, what does make a difference is referring only to publications that have successfully passed peer review. Citation practice is one of many issues that a simulation model of science can address when the data-rich literature on scientometrics is connected to the analogy-rich literature on organisations and heuristic search.

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Abstract

We develop a model of scientific creativity and test it in the field of rare diseases. Our model is based on the results of an in-depth case study of the Rett Syndrome. Archival analysis, bibliometric techniques and expert surveys are combined with network analysis to identify the most creative scientists. First, we compare alternative measures of generative and combinatorial creativity. Then, we generalize our results in a stochastic model of socio-semantic network evolution. The model predictions are tested with an extended set of rare diseases. We find that new scientific collaborations among experts in a field enhance combinatorial creativity. Instead, high entry rates of novices are negatively related to generative creativity. By expanding the set of useful concepts, creative scientists gain in centrality. At the same time, by increasing their centrality in the scientific community, scientists can replicate and generalize their results, thus contributing to a scientific paradigm.

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Abstract

This study presents a mixed model that combines different indicators to describe and predict key structural and dynamic features of emerging research areas. Three indicators are combined: sudden increases in the frequency of specific words; the number and speed by which new authors are attracted to an emerging research area, and changes in the interdisciplinarity of cited references. The mixed model is applied to four emerging research areas: RNAi, Nano, h-Index, and Impact Factor research using papers published in the Proceedings of the National Academy of Sciences of the United States of America (1982–2009) and in Scientometrics (1978–2009). Results are compared in terms of strengths and temporal dynamics. Results show that the indicators are indicative of emerging areas and they exhibit interesting temporal correlations: new authors enter the area first, then the interdisciplinarity of paper references increases, then word bursts occur. All workflows are reported in a manner that supports replication and extension by others.

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Abstract

The study presents the state of bibliographical research in the discipline of Hebrew printing during a 30-year period, ranging from the latter quarter of the twentieth century until the beginning of the third millennium (1976–2006). Through bibliographical parameters it characterizes the publications dealing with Hebrew printing, examines whether the published material exhibits laws and systematic regularities that are consistent with Bibliometrics, and describes directions in which the field has developed.

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Abstract

The paper introduces scholarly Information Retrieval (IR) as a further dimension that should be considered in the science modeling debate. The IR use case is seen as a validation model of the adequacy of science models in representing and predicting structure and dynamics in science. Particular conceptualizations of scholarly activity and structures in science are used as value-added search services to improve retrieval quality: a co-word model depicting the cognitive structure of a field (used for query expansion), the Bradford law of information concentration, and a model of co-authorship networks (both used for re-ranking search results). An evaluation of the retrieval quality when science model driven services are used turned out that the models proposed actually provide beneficial effects to retrieval quality. From an IR perspective, the models studied are therefore verified as expressive conceptualizations of central phenomena in science. Thus, it could be shown that the IR perspective can significantly contribute to a better understanding of scholarly structures and activities.

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Abstract

The Hsinchu Science Park in Taiwan has been synonymous with dynamic and flourishing high-tech industries and companies since the 1980s. Using patent citation data, this empirical study shows that Taiwan's Hsinchu Science Park is a healthy and knowledge-based cluster surrounded by the semiconductor sector, in which external knowledge is continuously playing an important role, while internalized capability is building up quickly; new and extended industrial clusters are being established by the growth of new ventures; and the linkages of capital, manpower, and technology flows are conducted respectively by the large business groups, the NTHU and NCTU, and the ITRI in the region. Subsequent sectors, repeating the successful model created by and catalyzed from the semiconductor sector are flourishing; the thin-film transistor-liquid crystal display (TFT-LCD) and integrated circuit (IC) design sectors have been growing rapidly since the beginning of the 2000s, and the solar photovoltaic and LED (Light-Emitting Diode) sectors emerged quickly in mid-2005. The continuous evolving and growing industries along with the significant increase of value added in the Hsinchu Science Park have demonstrated it is acting as a healthy and vivid innovation region. The policy implications derived from this study can thus shed light, for the Southeast Asian, Latin American or other latecomers, on the strategies for formulating regional research and innovation policies in the process of developing a knowledge-based economy.

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Abstract

The aim of this paper is to identify the research paradigms on digital libraries in China while compared with that of international digital libraries research via scientometric analysis. Co-word network constructed by keywords in documents and their co-occurrence relationships is a kind of mapping knowledge domains, which represents the cognitive and intellectual structure of science. A total of 6068 and 1250 papers published between 1994 and 2010 were, respectively retrieved from the China National Knowledge Infrastructure (CNKI) and ScienceDirect databases with a topic search of digital libraries or digital library in abstracts of papers. This paper uses methods of co-word analysis, social network analysis and mapping knowledge domains as theory basis, with assistance of softwares of UCINET and Netdraw, to construct the co-word network of digital libraries/library research in China, present the study status quo and evolution on digital libraries/library in China and analyze the research paradigm structure of digital libraries/library in China.

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Abstract

We obtain all solutions of the equation with c∊{±1,±2,±4}.

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Abstract

The objective of this paper is to offer sufficient conditions for the oscillation of all solutions and other asymptotic properties of the third-order nonlinear functional differential equation

ea
with mixed arguments, where both cases ∫ a −1/γ(s) ds=∞ and ∫ a −1/γ(s) ds<∞ are dealt with. We deduce properties of the studied equations via new comparison theorems. Our results essentially improve and complement earlier ones. We also repair one interesting result of Grace et al.

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This work analyses the links between individual research performance and academic rank. A typical bibliometric methodology is used to study the performance of all Italian university researchers active in the hard sciences, for the period 2004–2008. The objective is to characterize the performance of the ranks of full (FPs), associate and assistant professors (APs), along various dimensions, in order to verify the existence of performance differences among the ranks in general and for single disciplines.

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Acta Mathematica Hungarica
Authors: Santanu Bhunia, Pratulananda Das and Sudip Kumar Pal

Abstract

We first introduce a new notion called statistical convergence of order α and primarily show that it gives rise to a decreasing chain of closed linear subspaces of the space of all bounded real sequences with sup norm which never coincides with the class of convergent sequences and in fact their intersection properly contains the class of convergent sequences. We then show that the same method can be applied for double sequences also and introduce the notion of statistical convergence of order (α,β).

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Abstract

We prove that the conjugate convolution operators can be used to calculate jumps for functions. Our results generalize the theorems established by He and Shi. Furthermore, by using Lukács and Móricz's idea, we solve an open question posed by Shi and Hu.

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Abstract

In reaction to a previous critique (Opthof and Leydesdorff, J Informetr 4(3):423–430, ), the Center for Science and Technology Studies (CWTS) in Leiden proposed to change their old “crown” indicator in citation analysis into a new one. Waltman (Scientometrics 87:467–481, ) argue that this change does not affect rankings at various aggregated levels. However, CWTS data is not publicly available for testing and criticism. Therefore, we comment by using previously published data of Van Raan (Scientometrics 67(3):491–502, to address the pivotal issue of how the results of citation analysis correlate with the results of peer review. A quality parameter based on peer review was neither significantly correlated with the two parameters developed by the CWTS in the past citations per paper/mean journal citation score (CPP/JCSm) or CPP/FCSm (citations per paper/mean field citation score) nor with the more recently proposed h-index (Hirsch, Proc Natl Acad Sci USA 102(46):16569–16572, ). Given the high correlations between the old and new “crown” indicators, one can expect that the lack of correlation with the peer-review based quality indicator applies equally to the newly developed ones.

Open access

Abstract

We study the spectral multiplicity for the direct sum AB of operators A and B on the Banach spaces X and Y. Under some domination conditions ‖P(B)‖≦CP(A)‖, in particular, ‖B n‖≦CA n‖, n≧0, we prove the addition formulas μ(AB)=μ(A)+μ(B) for spectral multiplicities. We give valuable new applications of the main result of the author’s paper [12]. We also use the so-called Borel transformation and generalized Duhamel product in calculating the spectral multiplicity of a direct sum of the form TA, where T is a weighted shift operator on the Wiener algebra .

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Abstract

We consider fourth order quasilinear ordinary differential equations. Firstly, we classify positive solutions into four types according to their asymptotic properties. Then we derive existence theorems of positive solutions belonging to each type. Using these results, we can obtain an oscillation criterion, which is our main objective. Moreover, applying such criteria for ordinary differential equations to binary elliptic systems, we establish nonexistence theorems for positive solutions.

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Acta Mathematica Hungarica
Authors: Afshin Amini, Babak Amini, Ehsan Momtahan and Mohammad Hassan Shirdareh Haghighi

Abstract

We associate a graph Γ+(R) to a ring R whose vertices are nonzero proper right ideals of R and two vertices I and J are adjacent if I+J=R. Then we try to translate properties of this graph into algebraic properties of R and vice versa. For example, we characterize rings R for which Γ+(R) respectively is connected, complete, planar, complemented or a forest. Also we find the dominating number of Γ+(R).

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Abstract

A nonnegative linear relation S in a Hilbert space ℌ is assumed to intertwine in a certain sense two bounded everywhere defined operators B and C. A related quotient of the range of S is then provided with a natural inner product and the operators B and C induce two operators on the completion space. This construction is used to show the existence of self-adjoint and nonnegative extensions of the linear relations B S and C S, respectively.

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Abstract

Given a finite family of linear forms with integer coefficients, and a compact abelian group G, an -free set in G is a measurable set which does not contain solutions to any equation L(x)=0 for L in . We denote by the supremum of μ(A) over -free sets AG, where μ is the normalized Haar measure on G. Our main result is that, for any such collection of forms in at least three variables, the sequence converges to as p→∞ over primes. This answers an analogue for ℤp of a question that Ruzsa raised about sets of integers.

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Abstract

We study several aspects of the geometry of conformally stationary Lorentz manifolds, and particularly of GRW spaces, due to the presence of a closed conformal vector field. More precisely, we begin by extending a result of J. Simons on the minimality of cones in Euclidean space to these spaces, and apply it to the construction of complete, noncompact minimal Lorentz submanifolds of both de Sitter and anti-de Sitter spaces. Then we state and prove very general Bernstein-type theorems for spacelike hypersurfaces in conformally stationary Lorentz manifolds, one of which not assuming the hypersurface to be of constant mean curvature. Finally, we study the strong r-stability of spacelike hypersurfaces of constant r-th mean curvature in a conformally stationary Lorentz manifold of constant sectional curvature, extending previous results in the current literature.

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Abstract

A. Dubickas and C. Smyth introduced the metric Mahler measure

ea
where M(α) denotes the usual (logarithmic) Mahler measure of . This definition extends in a natural way to the t-metric Mahler measure by replacing the sum with the usual L t norm of the vector (M(α 1),…,M(α N)) for any t≧1. For α∊ℚ, we prove that the infimum in M t(α) may be attained using only rational points, establishing an earlier conjecture of the second author. We show that the natural analogue of this result fails for general by giving an infinite family of quadratic counterexamples. As part of this construction, we provide an explicit formula to compute M t(D 1/k) for a squarefree D∊ℕ.

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Acta Mathematica Hungarica
Authors: Villő Csiszár, Péter Hussami, János Komlós, Tamás F. Móri, Lídia Rejtő and Gábor Tusnády

Abstract

There is a uniquely defined random graph model with independent adjacencies in which the degree sequence is a sufficient statistic. The model was recently discovered independently by several authors. Here we join to the statistical investigation of the model, proving that if the degree sequence is in the interior of the polytope defined by the Erdős–Gallai conditions, then a unique maximum likelihood estimate exists.

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Abstract

This paper suggests a method for Subject–Action–Object (SAO) network analysis of patents for technology trends identification by using the concept of function. The proposed method solves the shortcoming of the keyword-based approach to identification of technology trends, i.e., that it cannot represent how technologies are used or for what purpose. The concept of function provides information on how a technology is used and how it interacts with other technologies; the keyword-based approach does not provide such information. The proposed method uses an SAO model and represents “key concept” instead of “key word”. We present a procedure that formulates an SAO network by using SAO models extracted from patent documents, and a method that applies actor network theory to analyze technology implications of the SAO network. To demonstrate the effectiveness of the SAO network this paper presents a case study of patents related to Polymer Electrolyte Membrane technology in Proton Exchange Membrane Fuel Cells.

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The algorithms of Shimoyama and Yokoyama for primary decomposition of ideals are generalized to submodules of a free module over the polynomial ring in several variables with coefficients in a field. The algorithms are implemented in Singular.

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In the applications it may occur that our initial pseudorandom binary sequence is not long enough, thus we have to take the concatenation of it with another pseudorandom binary sequences. Here we will consider concatenation of Legendre symbol sequences so that the resulting longer sequence has strong pseudorandom properties.

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In this paper we study I-approximation properties of certain class of linear positive operators. The two main tools used in this paper are I-convergence and Ditzian-Totik modulus of smoothness. Furthermore, we define q-Lupaş-Durrmeyer operators and give local and global approximation results for such operators.

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In this paper, the joint approximation of a given collection of analytic functions by a collection of shifts of zeta-functions with periodic coefficients is obtained. This is applied to prove the functional independence for these zeta-functions.

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The midpoint set M(S) of a set S of points is the set of all midpoints of pairs of points in S. We study the largest cardinality of a midpoint set M(S) in a finite-dimensional normed space, such that M(S) is contained in the unit sphere, and S is outside the closed unit ball. We show in three dimensions that this maximum (if it exists) is determined by the facial structure of the unit ball. In higher dimensions no such relationship exists. We also determine the maximum for euclidean and sup norm spaces.

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An abelian p-group G has a nice basis if it is the ascending union of a sequence of nice subgroups, each of which is a direct sum of cyclic groups. It is shown that if G is any group, then GD has a nice basis, where D is the divisible hull of p ω G. This leads to a consideration of the nice basis rank of G, i.e., the smallest rank of a divisible group D such that GD has a nice basis. This concept is used to show that there exist a reduced group G and a non-reduced group H, both without a nice basis, such that GH has a nice basis

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Scientometrics
Authors: Ludo Waltman, Nees Jan van Eck, Thed N. van Leeuwen, Martijn S. Visser and Anthony F. J. van Raan

Abstract

Opthof and Leydesdorff (Scientometrics, ) reanalyze data reported by Van Raan (Scientometrics 67(3):491–502, ) and conclude that there is no significant correlation between on the one hand average citation scores measured using the CPP/FCSm indicator and on the other hand the quality judgment of peers. We point out that Opthof and Leydesdorff draw their conclusions based on a very limited amount of data. We also criticize the statistical methodology used by Opthof and Leydesdorff. Using a larger amount of data and a more appropriate statistical methodology, we do find a significant correlation between the CPP/FCSm indicator and peer judgment.

Open access

The limit q-Bernstein operator B q = B ∞,q: C[0, 1] → C[0, 1] emerges naturally as a q-version of the Szász-Mirakyan operator related to the q-deformed Poisson distribution. The latter is used in the q-boson theory to describe the energy distribution in a q-analogue of the coherent state.The limit q-Bernstein operator has been widely studied lately. It has been shown that B q is a positive shape-preserving linear operator on C[0, 1] with ‖B q‖ = 1. Its approximation properties, probabilistic interpretation, behavior of iterates, and the impact on the smoothness have been examined.In this paper, it is shown that the possibility of an analytic continuation of B q f into {z: |z| < R}, R > 1, implies the smoothness of f at 1, which is stronger when R is greater. If B q f can be extended to an entire function, then f is infinitely differentiable at 1, and a sufficiently slow growth of B q f implies analyticity of f in {z: |z − 1| < δ}, where δ is greater when the growth is slower. Finally, there is a bound for the growth of B q f which implies f to be an entire function.

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In this paper, we prove that a space X is a weak-open compact image of a locally separable metric space if and only if X has a uniform cosmic-weak-base if and only if X is a weak-open compact image of a metric space and a locally cosmic space, and give some internal characterizations of weak-open s-images of locally separable metric spaces.

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Abstract

This paper by using data envelopment analysis (DEA) and statistical inference evaluates the citation performance of 229 economic journals. The paper categorizes the journals into four main categories (A–D) based on their efficiency levels. The results are then compared to the 27 “core economic journals” as introduced by Diamond (Curr Contents 21(1):4–11, ). The results reveal that after more than 20 years Diamonds’ list of “core economic journals” is still valid. Finally, for the first time the paper uses data from four well-known databases (SSCI, Scopus, RePEc, Econlit) and two quality ranking reports (Kiel Institute internals ranking and ABS quality ranking report) in a DEA setting and in order to derive the ranking of 229 economic journals. The ten economic journals with the highest citation performance are Journal of Political Economy, Econometrica, Quarterly Journal of Economics, Journal of Financial Economics, Journal of Economic Literature, American Economic Review, Review of Economic Studies, Journal of Econometrics, Journal of Finance, Brookings Papers on Economic Activity.

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With the modern technology fast developing, most of entities can be observed by different perspectives. These multiple view information allows us to find a better pattern as long as we integrate them in an appropriate way. So clustering by integrating multi-view representations that describe the same class of entities has become a crucial issue for knowledge discovering. We integrate multi-view data by a tensor model and present a hybrid clustering method based on Tucker-2 model, which can be regarded as an extension of spectral clustering. We apply our hybrid clustering method to scientific publication analysis by integrating citation-link and lexical content. Clustering experiments are conducted on a large-scale journal set retrieved from the Web of Science (WoS) database. Several relevant hybrid clustering methods are cross compared with our method. The analysis of clustering results demonstrate the effectiveness of the proposed algorithm. Furthermore, we provide a cognitive analysis of the clustering results as well as the visualization as a mapping of the journal set.

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Scientometrics
Authors: Daniel Torres-Salinas, Jose G. Moreno-Torres, Emilio Delgado-López-Cózar and Francisco Herrera

Abstract

The problem of comparing academic institutions in terms of their research production is nowadays a priority issue. This paper proposes a relative bidimensional index that takes into account both the net production and the quality of it, as an attempt to provide a comprehensive and objective way to compare the research output of different institutions in a specific field, using journal contributions and citations. The proposed index is then applied, as a case study, to rank the top Spanish universities in the fields of Chemistry and Computer Science in the period ranging from 2000 until 2009. A comparison with the top 50 universities in the ARWU rankings is also made, showing the proposed ranking is better suited to distinguish among non-elite universities.

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Abstract  

Using classical analytic techniques, a double inequality for differences of power means and geometric means in two variables is generalized and sharpened. A new inequality for differences of power means involving four parameters is established.

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We prove the equivalence of some three-weighted criteria for the boundedness of Hardy type operators on the cone of decreasing functions. These criteria are then applied to realize the direct comparisons of the results obtained in different forms in the papers of several authors (M. Goldman, G. Bennett and K.-G. Grosse-Erdmann, M. Carro, A. Gogatishvili, J. Martin, and L. Pick).

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Реэюме  

В работе построены раэложения тождественного оператора в пространстве L p(I d) в кратные ряды иэ ортопроекционных операторов на вэаимно ортогональные подпространства кусочно-полиномиальных функции, частным случаем которых является ряд Хаара. Юстановлены оценки норм в L p(I d) соответствуюших проекции. С их помошью получены оценки колмогоровского n-поперечника в пространстве L 2(I d) для единичных щаров пространств Никольского и QBесова функции, удовлетворяюших смещанным условиям Гёльдера, даюшие порядок тои величины.

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Abstract

To provide an overview of the characteristics of research in China, a bibliometric evaluation of highly cited papers with high-level representation was conducted during the period from 1999 to 2009 based on the Essential Science Indicators (ESI) database. A comprehensive assessment covered overall performance, journals, subject categories, internationally collaborative countries, national inter-institutionally collaborative institutions, and most-cited papers in 22 scientific fields. China saw a strong growth in scientific publications in the last decade, to some extent due to increasing research and development expenditure. China has been more active in ESI fields of chemistry and physics, but more excellent in materials science, engineering and mathematics. Most publications were concerned with the common Science Citation Index subject categories of multidisciplinary chemistry, multidisciplinary materials and science, and physical chemistry. About one half China's ESC papers were internationally collaborative and the eight major industrialized countries (the USA, Germany, the UK, Japan, France, Canada, Russia, and Italy) played a prominent role in scientific collaboration with China, especially the USA. The Chinese Academy of Sciences took the leading position of institutions with many branches. The “985 Project” stimulated the most productive institutions for academic research with a huge funding injection and the universities in Hong Kong showed good scientific performance. The citation impact of internationally collaborative papers differed among fields and international collaborations made positive contributions to academic research in China.

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Abstract

In academia, the term “inbreeding” refers to a situation wherein PhDs are employed in the very same institution that trained them during their doctoral studies. Academic inbreeding has a negative perception on the account that it damages both scientific effectiveness and productivity. In this article, the effect of inbreeding on scientific effectiveness is investigated through a case study. This problem is addressed by utilizing Hirsch index as a reliable metric of an academic's scientific productivity. Utilizing the dataset, constructed with academic performance indicators of individuals from the Mechanical and Aeronautical Engineering Departments, of the Turkish Technical Universities, we demonstrate that academic inbreeding has a negative impact on apparent scientific effectiveness through a negative binomial model. This model appears to be the most suitable one for the dataset which is a type of count data. We report chi-square statistics and likelihood ratio test for the parameter alpha. According to the chi-square statistics the model is significant as a whole. The incidence rate ratio for the variable “inbreeding” is estimated to be 0.11 and this ratio tells that, holding all the other factors constant, for the inbred faculty, the h-index is about 89% lower when compared to the non-inbred faculty. Furthermore, there exists negative and statistically significant correlation with an individual's productivity and the percentage of inbred faculty members at the very same department. Excessive practice of inbreeding adversely affects the overall productivity. Decision makers are urged to limit this practice to a minimum in order to foster a vibrant research environment. Furthermore, it is also found that scientific productivity of an individual decreases towards the end of his scientific career.

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Abstract

The single publication H-index, introduced by A. Schubert in 2009 can be applied on all articles in the Hirsch-core of a researcher. In this way one can define the “indirect H-index” of a researcher.

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Abstract

This paper provides an overview of the progression of technology structure based on patent co-citation networks. Methods of patent bibliometrics, social network analysis and information visualization are employed to analyze patents of Fortune 500 companies indexed in Derwent Innovations Index, the largest patent database in the world. Based on the co-citation networks, several main technology groups are identified, including Chemicals, Petroleum Refining, Motor Vehicles, Pharmaceuticals, Electronics, etc. Relationships among the leading companies and technology groups are also revealed.

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Abstract  

We obtain necessary conditions for a doubly triangular matrix A to have the property that a double series ΣΣ λmn b mn is summable |A|k whenever the series ΣΣb mn is bounded |A|k.

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We prove that the “quadratic irrational rotation” exhibits a central limit theorem. More precisely, let α be an arbitrary real root of a quadratic equation with integer coefficients; say, . Given any rational number 0 < x < 1 (say, x = 1/2) and any positive integer n, we count the number of elements of the sequence α, 2α, 3α, ..., modulo 1 that fall into the subinterval [0, x]. We prove that this counting number satisfies a central limit theorem in the following sense. First, we subtract the “expected number” nx from the counting number, and study the typical fluctuation of this difference as n runs in a long interval 1 ≤ nN. Depending on α and x, we may need an extra additive correction of constant times logarithm of N; furthermore, what we always need is a multiplicative correction: division by (another) constant times square root of logarithm of N. If N is large, the distribution of this renormalized counting number, as n runs in 1 ≤ nN, is very close to the standard normal distribution (bell shaped curve), and the corresponding error term tends to zero as N tends to infinity. This is the main result of the paper (see Theorem 1.1).

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Abstract

Using fixed point methods, we prove the generalized Hyers–Ulam stability of homomorphisms in multi-C ternary algebras and of derivations on multi-C ternary algebras for the additive functional equation

e1

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Abstract

If we have two information production processes with the same h-index, random removal of items causes one system to have a higher h-index than the other system while random removal of sources causes the opposite effect. In a Lotkaian framework we prove formulae for the h-index in case of random removal of items and in case of random removal of sources. In conclusion, we warn for the use of the h-index in case of incomplete data sets.

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Abstract

The aim of this paper is to prove some common fixed point theorems under certain strict contractive conditions for mappings sharing the common property (E.A) in Menger spaces. As applications to our results, we obtain the corresponding common fixed point theorems under strict contraction in metric spaces. Thus, our results generalize many known results in Menger as well as metric spaces. Some related results are also derived besides presenting several illustrative examples.

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Abstract

If is a system of infinite sets, |AB|<r for (r<ω) then has a conflict free coloring with ω colors, i.e., a function so that each has a color i<ω with |F −1(i)∩A|=1.

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Abstract

We study the thermoelastic system in a domain with moving boundary, which was obtained when, instead of the Fourier’s law for the heat flux relation, we followed the linearized model proposed by Coleman and Gurtin [3] and Gurtin and Pipkin [6] about the memory theory of heat conduction. We show the existence, uniqueness and exponential decay rate of global regular solutions.

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