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Abstract  

A problem of Ghorbani leads to an interesting example in the Theory of Majorization.

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Abstract

The first part of the paper deals with the assessment of international databases in relation to the number of historical publications (representation and relevance in comparison with the model database). The second part is focused on providing answer to the question whether historiography is governed by similar bibliometric rules as exact sciences or whether it has its own specific character. Empirical database for this part of the research constituted the database prepared ad hoc: The Citation Index of the History of Polish Media (CIHPM). Among numerous typically historical features the main focus was put on: linguistic localism, specific character of publishing forms, differences in citing of various sources (contributions and syntheses) and specific character of the authorship (the Lorenz Curve and the Lotka's Law). Slightly more attention was devoted to the half-life indicator and its role in a diachronic study of a scientific field; also, a new indicator (HL14), depicting distribution of citations younger then half-life was introduced. Additionally, the comparison and correlation of selected parameters for the body of historical science (citations, HL14, the Hirsch Index, number of publications, volume and other) were also conducted.

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Authors: Carlo Caputo, Jaime Requena and Domingo Vargas

Abstract

The development, current status and dynamics of research in biology related domains in Venezuela is examined through the study of demographic, academic distribution, scientific output and productivity, for two sets of investigators that fit a profile outlined for life sciences researchers or scientists. The first group corresponds to biologists extracted from the ranks of the official Program for the Promotion of Researchers (PPI), the other, pulled out from those that publish in biologically oriented journals, indexed by the Institute of Scientific Information (ISI). Both sets of biology scientists, PPI researchers or Web of Science/ISI scientists, show similar characteristics. The number (absolute and relative) of PPI member that are supposedly dedicated to biological research but do not publish in ISI indexed journals was found to be very similar to the number of supposedly non biologist members of the PPI Program that do publish biological articles in ISI indexed journals. There is also an ongoing feminization process, of academic hierarchies. Female biologists predominate in lower academic ranks and in research cadres, as many as 70% in some areas of biology. This contrasts with the pattern of male predominance observed during the second half of twentieth century in the country. Productivity of Venezuelan biologists seems to depend on gender; men are more productive that their female counterparts. From the bibliometric standpoint, it is found that, on average, 30% of all publications produced in the country are related to biology (or life sciences). The Venezuelan biologists network qualifies neither as a ‘Small World’ nor it follows the ‘Scale Free’ model. Finally, in a country rich in renewable natural resources, it seems that the Venezuelan community of researchers in biology is in decline, despite the fact that they constitute its most productive group of investigators.

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The main purpose of this study was to evaluate the global progress and quantitative assessment of current research trends on family therapy, using a bibliometric approach and exploring related literature in the Social Science Citation Index (SSCI) database from 1992 to 2009. This study used the bibliometric arrropach to learn about the subject categories, core journals, top countries and leading research institutes in publication, most frequently used author keywords, and most frequently used KeyWords Plus. Also, this study used a “word cluster analysis” method to locate research hot topics. A majority of the subject categories were located in clinical psychology and family studies. The core journals for family therapy located in Journal of Marital and Family Therapy, Contemporary Family Therapy, and Journal of Family Therapy. The US ranked as the top country of world articles with the highest h-index, followed distantly by the UK and Germany. The leading research institutes were Purdue University, University of Miami, and Brigham Young University. “Adolescents” and “adolescent” were highly used words in article titles. Next, the top three most frequently used author keywords were “anorexia nervosa”, “adolescents”, and “psychotherapy”. Finally, the top three most frequently used KeyWords Plus were “psychotherapy”, “children”, and “intervention”. Based on “word cluster analysis” to determine the research hotspots, the research hot topics of family therapy fall into three categories: treated subjects, treated matters, and treatment issues. The research trend in family therapy seems to involve the therapist often treating adolescents or children for eating disorders, substance abuse, depression, or schizophrenia. During treatment or therapy, therapists and researchers must pay attention to the issues of gender, training, and therapeutic alliance.

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Abstract

This paper introduces a diffusion network model: an individual-citation-based directed network model with a time dimension, as a potentially useful approach to capture the diffusion of research topics. The approach combines social network analysis, network visualization and citation analysis to discuss some of the issues concerning the spread of scientific ideas. The process of knowledge diffusion is traced from a network point of view. Using research on the h-index as a case study, we built detailed networks of individual publications and demonstrated the feasibility of applying the diffusion network model to the spread of a research. The model shows the specific paths and associations of individual papers, and potentially complementing issues raised by epidemic models, which primarily deal with average properties of entire scientific communities. Also, based on the citation-based network, the technique of main path analysis identified the articles that influenced the research for some time and linked them into a research tradition that is the backbone of the h-index field.

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Authors: Gábor Nagy, Gyula Pap and Ágnes Szendrei
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Abstract  

In several scale free graph models the asymptotic degree distribution and the characteristic exponent change when only a smaller set of vertices is considered. After recalling the sufficient conditions for the existence of asymptotic local degree distribution [1], several random graph models are presented that satisfy these assumptions. We show the necessity of the main conditions by constructing counterexamples.

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Abstract  

The injectivity of the commutant mapping of asymptotically nonvanishing contractions is examined. We show that this mapping can be injective even in the presence of a non-trivial stable subspace. Various characterizations of injectivity are provided.

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Abstract  

Chaundy and Jolliffe proved their classical theorem on the uniform convergence of sine series with monotone coefficients in 1916. Lately, it has been generalized using classes MVBVS and SBVS2 instead of monotone sequences. In two variables, the class MVBVDS was studied under the uniform regular convergence of double sine series. We shall generalize those results defining a new class of double sequences for the coefficients.

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Abstract  

We consider the delay differential equation

\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\dot x(t) = - \mu x(t) + f(x(t - \tau ))$$ \end{document}
, where µ, τ are positive parameters and f is a strictly monotone, nonlinear C 1-function satisfying f(0) = 0 and some convexity properties. It is well known that for prescribed oscillation frequencies (characterized by the values of a discrete Lyapunov functional) there exists τ* > 0 such that for every τ > τ* there is a unique periodic solution. The period function is the minimal period of the unique periodic solution as a function of τ > τ*. First we show that it is a monotone nondecreasing Lipschitz continuous function of τ with Lipschitz constant 2. As an application of our theorem we give a new proof of some recent results of Yi, Chen and Wu [14] about uniqueness and existence of periodic solutions of a system of delay differential equations.

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This study analyzes the level of co-authorship of Spanish research in Library and Information Science (LIS) until 2009, the chronological development that has taken place, and the level of local, domestic and international cooperation. This bibliometric study was made using the data retrieved from the Web of Knowledge (WoK) following a dual strategy—on the one hand through the filter of the category Information Science & Library Science, and on the other hand through a subject search. In this way a significant number of works has been retrieved, some of which are in journals indexed in SCI or A&HCI and not in the SSCI. The results show a significant increase in all co-authorship, including publications in English and those involving international collaboration. As with the increase in Spanish participation in social science (WoK), this growth, coupled with the significant increase in Spanish scientific production in the area of LIS, suggests that the discipline in Spain has entered a more mature phase—although so far it has focused particularly on bibliometric studies.

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Abstract  

We give a description of the terms in the Ringel-Hall product of preinjective Kronecker modules. We characterize in this way all the short exact sequences of preinjective modules. As an application we also give an explicit solution to the column completion challenge for pencils with only minimal indices for columns (corresponding to preinjective modules) and to the row completion challenge for pencils with only minimal indicies for rows (corresponding to preprojective modules).

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Authors: Orsolya Sáfár, László Kőhidai and Andrea Hegedűs

Abstract  

In our paper we investigate the unbiased movement of the unicellular eukaryotic ciliate Tetrahymena Pyriformis. We use a time-delayed version of the previously known model to describe the specific movement of this species. With the help of semi-discretization, we state analytic results for the model.

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Abstract

Many forms of technology cycle models have been developed and utilized to identify new/convergent technologies and forecast social changes, and among these, the technology hype cycle introduced by Gartner has become established as an effective method that is widely utilized in the field. Despite the popularity of this commonly deployed model, however, the currently existing research literature fails to provide sufficient consideration of its theoretical frame or its empirical verification. This paper presents a new method for the empirical measurement of this hype cycle model. In particular, it presents a method for measuring the hype of the users rather than the hype cycle generated by research activities or by the media by means of analyzing the hype cycle using search traffic analysis. The analytical results derived from the case study of hybrid automobiles empirically demonstrated that following the introductory stage and the early growth stage of the life cycle, the positive hype curve and the negative hype curve, the representative figures of the hype cycle, were present in the bell curve for the users’ search behavior. Based on this finding, this paper proposes a new method for measuring the users’ expectation and suggests a new direction for future research that enables the forecasting of promising technologies and technological opportunities in linkage with the conventional technology life cycle model. In particular, by interpreting the empirical results using the consumer behavior model and the adoption model, this study empirically demonstrates that the characteristics of each user category can be identified through differences in the hype cycle in the process of the diffusion of new technological products discussed in the past.

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Abstract

To better understand the distribution of words in all kinds of syntactic structures, the paper calculates the word distribution in syntactic structures of both English and Chinese. On the basis of the calculation, the article presents the definition of the words’ syntactic distribution complexity. After arranging the Chinese and English words according to their own syntactic distribution complexity, respectively, the Lotka phenomenon can be clearly attested by the results. The discovery made in the paper reveals the law of the words’ syntactic distribution in linguistic studies on one hand and the statistically proven fact that Chinese words’ syntax is much more complex than that of the English after comparing the Lotka phenomenon of both Chinese and English words’ syntactic distribution complexity on the other hand.

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Abstract

Although the use of bibliometric indicators for evaluations in science is becoming more and more ubiquitous, little is known about how future publication success can be predicted from past publication success. Here, we investigated how the post-2000 publication success of 85 researchers in oncology could be predicted from their previous publication record. Our main findings are: (i) Rates of past achievement were better predictors than measures of cumulative achievement. (ii) A combination of authors’ past productivity and the past citation rate of their average paper was most successful in predicting future publication success (R 2 ≈ 0.60). (iii) This combination of traditional bibliographic indicators clearly outperformed predictions based on the rate of the h index (R 2 between 0.37 and 0.52). We discuss implications of our findings for views on creativity and for science evaluation.

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Abstract

A bibliometric analysis was performed in this work to determine research trends of oxidative stress publications published between 1991 and 2010 in journals of all the subject categories of the Science citation index. Publication trends were analyzed by the retrieved results in publication type and language, characteristics of articles outputs, country, subject categories and journals, and the frequency of title-words and keywords used. Over the years, there was a significant growth in article outputs, with more countries participating and collaborating. The seven major industrialized countries (G7) published the majority of the world articles while the USA contributed about one-third of the total. Chinese and Indian outputs grew much faster than those of other countries in the past 5 years. Oxidative stress research in food and environmental related fields gradually became the mainstream of the research. An analysis of the title-words, author keywords and keywords plus showed that antioxidants in human or rat cells were the hot topic in the field. In addition, “reaction oxygen species”, “apoptosis”, and “nitric-oxide” were major topics of oxidative stress research recently. More articles dealt with diseases that had a strong relationship with oxidative stress, such as inflammation, Alzheimer's disease, diabetes, and atherosclerosis.

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Abstract  

A generalization of density point with respect to category and I(J)-density topology has been presented in [5]. This papers deals with some basic properties of the corresponding I(J)-approximately continuous functions and gives answer when these functions are of the first Baire class and when they are Darboux functions.

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Abstract  

We calculate the ℤ2 obstruction ideals of all Morin singularities

\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\Sigma ^{1_r }$$ \end{document}
in Morin (corank 1) maps.

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Abstract  

For a finite abelian group A, the ring End(A) is a maximal ring in the nearring M(A). In this paper we consider an analogous problem for finite semigroups, concentrating on commutative Clifford semigroups.

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Abstract  

The least area α 2 of a convex set in the plane large enough to contain a congruent copy of every closed curve of length two lies between 0.385 and 0.491, as has been known for more than 38 years. We improve these bounds by showing that 0.386 < α 2 < 0.449.

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Abstract  

We use the method of moments to establish the limiting spectral distribution (LSD) of appropriately scaled large dimensional random symmetric circulant, reverse circulant, Toeplitz and Hankel matrices which have suitable band structures. The input sequence used to construct these matrices is assumed to be either i.i.d. with mean zero and variance one or independent and appropriate finite fourth moment. The class of LSD includes the normal and the symmetrized square root of chi-square with two degrees of freedom. In several other cases, explicit forms of the limit do not seem to be obtainable but the limits can be shown to be symmetric and their second and the fourth moments can be calculated with some effort. Simulations suggest some further properties of the limits.

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Abstract  

The trigonometric polynomials of Fejér and Young are defined by

\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$S_n (x) = \sum\nolimits_{k = 1}^n {\tfrac{{\sin (kx)}} {k}}$$ \end{document}
and
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$C_n (x) = 1 + \sum\nolimits_{k = 1}^n {\tfrac{{\cos (kx)}} {k}}$$ \end{document}
, respectively. We prove that the inequality
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\left( {{1 \mathord{\left/ {\vphantom {1 9}} \right. \kern-\nulldelimiterspace} 9}} \right)\sqrt {15} \leqslant {{C_n \left( x \right)} \mathord{\left/ {\vphantom {{C_n \left( x \right)} {S_n \left( x \right)}}} \right. \kern-\nulldelimiterspace} {S_n \left( x \right)}}$$ \end{document}
holds for all n ≥ 2 and x ∈ (0, π). The lower bound is sharp.

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Abstract  

Let m ≠ 0 be an integer which is not a perfect square and consider number fields of the form

\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\mathbb{Q}\left[ {\sqrt[4]{m}} \right]$$ \end{document}
. We characterize all orders of the form
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\mathbb{Z}\left[ {\sqrt[4]{m}} \right]$$ \end{document}
which admit a unit power integral basis, i.e., there exists a unit ε such that 1, ε, ε 2 and ε 3 is an integral basis of
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\mathbb{Z}\left[ {\sqrt[4]{m}} \right]$$ \end{document}
.

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Abstract  

A discrete nonautonomous two-species Lotka-Volterra competitive system with delays and feedback controls is proposed and investigated. By using the method of discrete Lyapunov functionals, new sufficient conditions on the permanence of species and global attractivity of the system are established. Particularly, an interesting fact is found in our results, that is, the feedback controls are harmless to the permanence of species for the considered system.

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Abstract  

We study unfoldings (developments) of doubly covered polyhedra, which are space-fillers in the case of cuboids and some others. All five types of parallelohedra are examples of unfoldings of doubly covered cuboids (Proposition 1). We give geometric properties of convex unfoldings of doubly covered cuboids and determine all convex unfoldings (Theorem 1). We prove that every unfolding of doubly covered cuboids has a space-filling (consisting of its congruent copies) generated by three specified translates and three specified rotations, and that all such space-fillers are derived from unfoldings of doubly covered cuboids (Theorem 2). Finally, we extend these results from cuboids to polyhedra which are fundamental regions of the Coxeter groups generated by reflections in the 3-space and which have no obtuse dihedral angles (Theorem 3).

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Abstract

Investigating Iran's scientific proficiency reflected in its scholarly outputs indexed in SCI during the 21st century and 1980s, the present study tries to propose the use of three features of science production including Specialty Diversity, Specialty Stability, and the growth of publications in the specialties, as the primary criteria in evaluating the contribution sustainability of a science system at macro level. They can be seen as the prerequisites every science system should realize to ensure a sustainable movement towards scientific development. The results reveal that Iran's contributions had been not only limited in number in 1980s, but also exposed to serious subject fluctuations, so that a scarce number of the fields were found to be stable regarding Iranian contributions. Moreover, none of them had experienced a significant, exponential positive growth during the decade. The situation is incomparable to the 21st century where Iran's contributions were as diversified as almost all of the SCI subject categories. It also reached long- or short-term stability in a majority of the categories. None of the previously stabilized specialties collapsed in the second 6-year sub-period. On the other hand, previously fluctuating fields mostly stabilized later. Moreover, a majority of the fields experienced significant exponential growths. Overall, according to the results, a developing science system might be characterized by its Specialty Diversity and Stability, as well as an annual growth in its publications in the specialties. Though meeting the criteria does not necessarily guarantee the achievement of quality standards, it may enhance the visibility of the contributions and thereby their recognition.

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Abstract

We investigated author information in scientific articles by approximately 7,000 researchers for a quantitative analysis of researchers’ international mobility. From top journals, we traced the movements of more than 2,200 researchers in the research domains of robotics, computer vision and electron devices. We categorized countries’ characteristics for the balance between the inflow and the outflow of researchers moving internationally. Flow patterns of international mobility confirm that the United States, China and India exhibit the greatest global flows of researchers, with Singapore and Hong Kong attracting remarkable numbers of researchers from other countries. International mobility focusing on institutions reveals that universities in Singapore receive as many foreign researchers as do research universities in the United States. Furthermore, firms and international collaborative research institutes act as alternative receivers to the universities in the electron devices research domain.

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Abstract

Purpose—this paper aims to look at the Hawthorne effect in editorial peer review. Design/methodology/approach—discusses the quality evaluation of refereed scholarly journals. Findings—a key finding of this research was that in the peer review process of one and the same manuscript, reviewers or editors, respectively, arrive at different judgments. This phenomenon is named as “Hawthorne effect” because the different judgements are dependent on the specific conditions under which the peer review process at the individual journals takes place. Originality/value—provides a discussion on the quality evaluation of scholarly journals.

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Abstract

For a long time, rankings overused in evaluating Chinese universities’ research performance. The relationship between research production and research quality hasn't been taken seriously in ranking systems. Most university rankings in China put more weight on research production rather than research quality. Recently, the developmental strategy of Chinese universities has shifted from ‘quantity’ to ‘quality’. As a result, a two-dimensional approach was developed in this article to balance ‘quantity’ and ‘quality’. The research production index and the research quality index were produced to locate research universities (RU) from Mainland China, Hong Kong (HK) and Taiwan (TW) in the two-dimensional graph. Fifty-nine RU were classified into three categories according to their locations, which indicated the relevant level of research performance. University of Hong Kong, National Taiwan University, Tsing Hua University and Peking University appeared to be leading universities in research performance. The result showed that the mainland universities were generally of higher research production and lower research quality than HK and TW universities, and proved that the merging tides of Chinese universities enlarged their research production while causing a low level of research quality as well.

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Abstract

There is a burgeoning interest among academic scientists and policy-makers in the development and employment of TH (Triple Helix) and WSI (Webometrics, Scientometrics, and Informetrics) research methods. However, the international literature has not systematically examined TH and WSI approaches in an Asian context. Furthermore, previous literature published in international journals does not adequately address the social forces shaping TH development in Asia. Therefore, the purpose of this special issue is to bring researchers together to discuss university-industry-government (U-I-G) relations and innovation diffusion in Asia employing WSI alongside other methods.

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Abstract

In the competitive business environment, early identification of technological opportunities is crucial for technology strategy formulation and research and development planning. There exist previous studies that identify technological directions or areas from a broad view for technological opportunities, while few studies have researched a way to detect distinctive patents that can act as new technological opportunities at the individual patent level. This paper proposes a method of detecting new technological opportunities by using subject–action–object (SAO)-based semantic patent analysis and outlier detection. SAO structures are syntactically ordered sentences that can be automatically extracted by natural language processing of patent text; they explicitly show the structural relationships among technological components in a patent, and thus encode key findings of inventions and the expertise of inventors. Therefore, the proposed method allows quantification of structural dissimilarities among patents. We use outlier detection to identify unusual or distinctive patents in a given technology area; some of these outlier patents may represent new technological opportunities. The proposed method is illustrated using patents related to organic photovoltaic cells. We expect that this method can be incorporated into the research and development process for early identification of technological opportunities.

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Abstract

Visualization of subject structure based on co-word analysis is used to explore the concept network and developmental tendency in certain field. There are many visualization methods for co-word analysis. However, integration of results by different methods is rarely reported. This article addresses the knowledge gap in this field of study. We compare three visualization methods: Cluster tree, strategy diagram and social network maps, and integrate different results together to one result through co-word analysis of medical informatics. The three visualization methods have their own character: cluster trees show the subject structure, strategic diagrams reveal the importance of topic themes in the structure, and social network maps interpret the internal relationship among themes. Integration of different visualization results to one more readable map complements each other. And it is helpful for researchers to get the concept network and developmental tendency in a certain field.

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Abstract

We argue that the creation of new knowledge is both difficult and rare. More specifically, we posit that the creation of new knowledge is dominated by a few key insights that challenge the way people think about an idea; generating high interest and use. We label this the blockbuster hypothesis. Using two large samples of published management studies over the period 1998–2007 we find support for the blockbuster hypothesis. We also find that numerous studies in the leading management journals are flops, having little impact on the profession as measured using citation data. Additional tests indicate that journal “quality” is related to the ratio of blockbusters to flops a journal publishes and that journal rankings are a poor proxy for study influence. Consistent with the notion that editorial boards are able to identify new knowledge, we find that research notes significantly under-perform articles in both the same journal and articles published in lower ranked journals. Taken together, the results imply that only a few scientific studies, out of the thousands published in a given area, change or influence the boundaries of knowledge, with many appearing to have little impact on the frontiers of knowledge. Overall, this analysis indicates that the development of new knowledge is rare even though it appears to be recognizable to knowledge gatekeepers like journal editors.

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Abstract

The editorial handling of articles in scientific journals as a human activity process is considered. Using recently proposed approaches of human dynamics theory we examine the probability distributions of random variables reflecting the temporal characteristics of studied processes. The first part of this article contains our results of analysis of the real data about articles published in scientific journals. The second part is devoted to modeling of time-series connected with editorial work. The purpose of our study is to present new object that can be studied in terms of human dynamics theory and to corroborate the scientometrical application of the results obtained.

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Abstract

Journal impact factor (JIF) has been used for journal evaluation over a long time, but also accompanied by the continuing controversy. In this study, a new indicator, the Journal's Integrated Impact Index (JIII) has been proposed for journal evaluation. In the JIII, one journal's average citations per paper, total citations, and all journals’ average level of average citations per paper and total citations have been used to characterize the integrated impact of journals. Some contrastive analyses were carried out between JIII and JIF. The results show some interesting properties of the new indicator, and also reveal some relevant relationships among JIII, JIF, and other bibliometric indicators.

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Abstract

This paper identifies the main references, authors and journals influencing the sustainable development literature. The task is accomplished by means of a citation analysis based on the records of ISI Web of Science. We found that the core of sustainability thinking is framed by a pattern of landmark studies published around every 5 years. Only 380 publications have been cited at least ten times. References with the highest influence are those with a global dimension and large diffusion, such as Brundtland Commission's “Our common future” (1987) and classics such as Meadows’ et al. “Limits to growth” (1972). The list of the most influential references over the period 1960–2005 is dominated by contributions from economics (particularly ecological economics) and environmental science, but includes many other disciplines such as urban planning, political sciences and sociology. References are also made to policy documents such as “Agenda 21”, one of the main outcomes of the Rio Summit in 1992. In analyzing citation trends, we found that classics, because of their high rates of citations per year, seem to have a more enduring and stable influence.

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Authors: J. A. García, Rosa Rodriguez-Sánchez, J. Fdez-Valdivia and J. Martinez-Baena

Abstract

Here we study the relationship between journal quartile rankings of ISI impact factor (at the 2010) and journal classification in four impact classes, i.e., highest impact, medium highest impact, medium lowest impact, and lowest impact journals in subject category computer science artificial intelligence. To this aim, we use fuzzy maximum likelihood estimation clustering in order to identify groups of journals sharing similar characteristics in a multivariate indicator space. The seven variables used in this analysis are: (1) Scimago Journal Ranking (SJR); (2) H-Index (H); (3) ISI impact factor (IF); (4) 5-Year Impact Factor (5IF); (5) Immediacy Index (II); (6) Eigenfactor Score (ES); and (7) Article Influence Score (AIS). The fuzzy clustering allows impact classes to overlap, thereby accommodating for uncertainty related to the confusion about the impact class attribution for a journal and vagueness in impact classes definition. This paper demonstrates the complex relationship between quartiles of ISI impact factor and journal impact classes in the multivariate indicator space. And that several indicators should be used for a distinct analysis of structural changes at the score distribution of journals in a subject category. Here we propose it can be performed in a multivariate indicator space using a fuzzy classifier.

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Abstract

Diversification of R&D projects not only can reduce overall risk, but also can create value-enhancement effect. A useful guideline for optimal diversification of R&D projects is important to R&D organizations. This paper extends financial portfolio analyses for R&D management particularly incorporating the technology risk. This study uses a survival model to describe the technology risk since termination of an R&D project can be caused by any technology risk factors. A formula of optimal R&D resource allocation that can dynamically achieve the greatest diversification effect is offered. Furthermore we provide an alternative method for estimating correlations between R&D portfolios, which has a critical influence on diversification effect. The method can be useful in risk assessment when measure the exposure of R&D portfolio to particular sources of uncertainty. The evaluation framework for R&D portfolios optimization also can be applied in project-selection decisions.

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Abstract

One of the major drawbacks of the classical Lotka function is that arguments only start from the value 1. However, in many applications one may want to start from the value 0, e.g. when including zero received citations. In this article we consider the shifted Lotka function, which includes the case of zero items. Basic results for the total number of sources, the total number of items and the average number of items per source are given in this framework. Next we give the rank-frequency function (Zipf-type function) corresponding to the shifted Lotka function and prove their exact relation. The article ends with a practical example which can be fitted by a shifted Lotka function.

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Abstract

Database management technology has played a vital role in facilitating key advancements of the information technology field. Database researchers—and computer scientists in general—consider prestigious conferences as their favorite and effective tools for presenting their original research study and for getting good publicity. With the main aim of retaining the high quality and the prestige of these conference, program committee members plays the major role of evaluating the submitted articles and deciding which submissions are to be included in the conference programs. In this article, we study the program committees of four top-tier and prestigious database conferences (SIGMOD, VLDB, ICDE, EDBT) over a period of 10 years (2001–2010). We report about the growth in the number of program committee members in comparison to the size of the research community in the last decade. We also analyze the rate of change in the membership of the committees of the different editions of these conferences. Finally, we report about the major contributing scholars in the committees of these conferences as a mean of acknowledging their impact in the community.

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Abstract

Two layers of enriched information are constructed for communities: a paper-to-paper network based on shared author relations and a paper-to-paper network based on shared word relations. k-means and VOSviewer, a modularity-based clustering technique, are used to identify publication clusters in the two networks. Results show that a few research topics such as webometrics, bibliometric laws, and language processing, form their own research community; while other research topics contain different research communities, which may be caused by physical distance.

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Abstract

In our previous work (Scientometrics 87:293–301, 2011), a numerical model of over-competitive research funding in “peer-group-assessed-grant-based-funding-system” was proposed and the process was firstly investigated quantitatively. The simulation results show that the mainstream of a very complicated research topic could obtain monopoly supremacy with only the aid of the mechanism the model described. Here, the numbers of publications of cosmology back to 1950 are utilized to empirically test this positive feedback mechanism. The development of three main theories of cosmology, Big Bang, Steady State and Plasma Universe, are revisited. The later two, which are non-mainstream opinions, both state in their peer reviewed papers, that their theories fit the phenomena that support the standard theory. The ratios of publications of the orthodox theory, Big Bang, approximately satisfy the numeric calculating results of our model. The reason for the discrepancy between the model and actual situation is discussed. A further question about the controversy is presented.

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This article analyzes the relationship between private and social value of patents, comparing discrete and cumulative innovation. Indicators of the social value of patents are known to be less correlated with measures of private value in technological fields where innovation is more cumulative. We test whether this is because the link between private and social value is weaker, or because the indicators are less informative of the underlying concepts of value. Furthermore we analyze whether these differences between technological fields are really due to cumulativeness. We observe cumulative innovation by making use of databases of patents declared essential for technological standards. Using factor analysis and a set of patent quality indicators, we test the relevance of social value for predicting the private value of a patent measured by renewal and litigation. Whereas we establish a robust and significant link for discrete technologies; neither common factors nor any indicator of social value allows predicting the private value of essential, very cumulative patents. Nevertheless, this result cannot be generalized to whole technological classes identified as “complex” by the literature.

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In computer science, as opposed to many other disciplines, papers published in conference and workshop proceedings count as formal publications when evaluating the scholarship of an academic. We consider the relationship between high quality journals and conferences in the computer vision (CV) subfield of computer science. We determined that 30% of papers in the top-3 CV journals base their work on top-3 conference papers by the same authors (which we call priors (See “” section for the definition of a prior)). Journal papers with priors are significantly more cited than journal papers without priors. Also the priors themselves are cited more than other papers from the conferences. For a period of 3–5 years after the journal paper publication, the priors receive more citations than the follow-up journal paper. After that period, the journal paper starts receiving most of the citations. Furthermore, we found that having the prior conference paper did not make it any easier (faster) to publish in a journal. We also surveyed journal authors and based on their answers and the priors analysis, we discovered that authors seem to be divided into different groups depending on their preferred method of publication.

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We prove an asymptotic formula for the average number of solutions to the Diophantine equation axyxy=n in which a is fixed and n varies.

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Abstract.

We consider complex-valued functions fL 1(ℝ+), where ℝ+:=[0,∞), and prove sufficient conditions under which the sine Fourier transform and the cosine Fourier transform belong to one of the Lipschitz classes Lip (α) and lip (α) for some 0<α≦1, or to one of the Zygmund classes Zyg (α) and zyg (α) for some 0<α≦2. These sufficient conditions are best possible in the sense that they are also necessary if f(x)≧0 almost everywhere.

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Let be a convex combination space as defined by Terán and Molchanov [13]. By using their definition of mathematical expectation of an -valued random variable, we state several new variants of strong laws of large numbers for double arrays of integrable -valued random variables under various assumptions. Some related results in the literature are extended.

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We prove some new direct and converse results on simultaneous approximation by the combinations of Bernstein–Kantorovich operators using the Ditzian–Totik modulus of smoothness.

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We consider the p-Laplacian type elliptic problem

ea
where Ω=Ω1×Ω2⊂ℝN is a bounded domain having cylindrical symmetry, Ω1⊂ℝm is a bounded regular domain and Ω2 is a k-dimensional ball of radius R, centered in the origin and m+k=N, m≧1, k≧2. Under some suitable conditions on the functions a and h, using variational methods we prove that the problem has at least one resp. at least two solutions in two cases: g=0 and g≠0.

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Authors: Vilmos Komornik, Zsolt Komornik and Christelle K. Viauroux

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In order to treat a natural schedule matching problem related with worker-firm matchings, we generalize some theorems of Baiou–Balinski and Alkan–Gale by applying a fixed point method of Fleiner.

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Authors: Carlo Alberto Mantica and Luca Guido Molinari

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We introduce a new kind of Riemannian manifold that includes weakly-, pseudo- and pseudo projective Ricci symmetric manifolds. The manifold is defined through a generalization of the so called Z tensor; it is named weakly Z-symmetric and is denoted by (WZS)n. If the Z tensor is singular we give conditions for the existence of a proper concircular vector. For non singular Z tensors, we study the closedness property of the associated covectors and give sufficient conditions for the existence of a proper concircular vector in the conformally harmonic case, and the general form of the Ricci tensor. For conformally flat (WZS)n manifolds, we derive the local form of the metric tensor.

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Let P r denote an almost-prime with at most r prime factors, counted according to multiplicity, and let E 3(N) denote the number of natural numbers not exceeding N that are congruent to 4 modulo 24 yet cannot be represented as the sum of three squares of primes and the square of one P 5. Then we have E 3(N)≪log1053 N. This result constitutes an improvement upon that of D. I. Tolev, who obtained the same bound, but with P 11 in place of P 5.

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Abstract.

We present some compactness properties of L-weakly and M-weakly compact operators on a Banach lattice under additional conditions. Thus, we can say that every bounded operator which commutes with any L-weakly or M-weakly compact operator have a non-trivial closed invariant subspace.

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Authors: Chuanfu Chen, Yuan Yu, Qiong Tang, Kuei Chiu, Yan Rao, Xuan Huang and Kai Sun

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Authority generally relates to expertise, recognition of official status of a source, and the reputation of the author and publisher. As the Internet has become a ubiquitous tool in modern science and scholarly research, evaluating the authority of free online scholarly information is becoming crucial. However, few empirical studies have focused on this issue. Using a modified version of Jim Kapoun's “Five criteria for evaluating web pages” as framework, this research selected 32 keywords from eight disciplines, inputted them into three search engines (Google, Yahoo and AltaVista) and used Analytic Hierarchy Process to determine the weights. The first batches of results (web pages) from keyword searching were selected as evaluation samples (in the two search phases, the first 50 and 10 results were chosen, respectively), and a total of 3,134 samples were evaluated for authority based on the evaluation framework. The results show that the average authority value for free online scholarly information is about 3.63 (out of five), which is in the “fair” level (3 ≤ Z < 4) (Z is the value assigned to each sample). About 41% of all samples collected provide more authoritative scholarly information. Different domain names, resource types, and disciplines of free online scholarly information perform differently when scored in terms of authority. In conclusion, the authority of free online scholarly information has been unsatisfactory, and needs to be improved. Furthermore, the evaluation framework and its application developed herein could be a useful instrument for librarians, researchers, students, and the public to select Internet resources.

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Abstract

Citations to published work are gaining increasing prominence in evaluations of the research performance of scientists. Considering the importance accorded to gender issues in South African science, it is surprising that (to our knowledge) no research has as yet ascertained the extent of sex differences in citations to the published work of scientists in this country. Our literature study shows that studies that have been conducted elsewhere tend to neglect in their analyses important gender-related and other factors, such as the sex composition of multi-authored papers and the extent of foreign co-authorship. Against this background, we illustrate the difficulties inherent in measuring the quality aspect of sex-specific research performance by means of an analysis of a dataset of articles (n = 229) that were published between 1990 and 2002 in the field of invasion ecology and in journals included in the Thomson Reuters Web of Science. Each article has at least one South African author address. The results indicate that foreign co-authorship is a better correlate of high citations than the sex of South African authors, and this is true irrespective of whether the annual citation rate or window period is used, whether or not self-citations are excluded, and whether or not the number of authors is controlled for by calculating fractional counts. The paper highlights these and other considerations that are relevant for future gender-focused bibliometric research, both in South Africa and beyond.

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Authors: Stephen Carley and Alan L. Porter

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We introduce an indicator to measure the diffusion of scientific research. Consistent with Stirling's 3-factor diversity model, the diffusion score captures not only variety and balance, but also disparity among citing article cohorts. We apply it to benchmark article samples from six 1995 Web of Science subject categories (SCs) to trace trends in knowledge diffusion over time since publication. Findings indicate that, for most SCs, diffusion scores steadily increase with time. Mathematics is an outlier. We employ a typology of citation trends among benchmark SCs and correlate this with diffusion scores. We also find that self-cites do not, in most cases, significantly influence diffusion scores.

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Authors: Jia Zheng, Zhi-Yun Zhao, Xu Zhang, Dar-Zen Chen, Mu-Hsuan Huang, Xiao-Ping Lei, Ze-Yu Zhang and Yun-Hua Zhao

Abstract

Since China adopted Open-Up and Reformed Policy for global collaboration, China's science and technology have experienced an astounding growth. Papers and patents encompass valuable scientific and technological (S&T) information and collaborative efforts. This article studies China's international S&T collaboration from the perspective of paper and patent analysis. The results show that China's total papers and patents have continuously increased from 2004 to 2008, the papers and patents resulting from China's international collaboration also present a steady growth. However, there is a decline in the share of international collaboration papers and patents with a certain range due to the rapid independent R&D. China's international scientific collaboration (ISC) is broadly distributed over many countries, the USA being the most important ISC partners. China's international technological collaboration (ITC) is mainly carried out with USA and Taiwan, and Taiwan has been the most significant ITC partner of when taking countries’ patent output into account. Besides, ISC shows a continuous raise of Chinese papers’ citation. Even the countries with a small amount of papers and ISC with China, exert a positive influence on the impact of citation of Chinese papers as well. However, ITC does not always play an active role in the improvement of citation impact of Chinese patents.

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Abstract

The Hirsch h-index is widely used to measure a researcher's major publications. It has the advantage of being easy to compute. However, it increases steeply with time and therefore does not allow a comparison of young and mature researchers. We find that if the h-index is divided by the number of decades since publication of the researcher's first paper, the result is statistically constant with age. Then the resulting index can be compared for young and old researchers. Its accuracy is the same as that of the h-index and is as easy to compute as the h-index.

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