Measuring academic entities’ impact by content-based citation analysis in a heterogeneous academic network

Scientometrics - Evaluating the impact of papers, researchers and venues objectively is of great significance to academia and beyond. This may help researchers, research organizations, and...     

How to assess sustainability of countries via inverse data envelopment analysis?

In this paper, two input-oriented and output-oriented inverse semi-oriented radial measures are presented. Such models are applied to determine resource allocation and investment strategies for assessing sustainability of countries. Our proposed models can deal with both positive and negative data. In our proposed inverse input-oriented data envelopment analysis (DEA) model, optimal inputs are suggested while outputs and efficiency score of decision-making unit (DMU) under evaluation are unchanged. Similarly, in our proposed inverse output-oriented DEA model, optimal outputs are proposed while inputs and efficiency score of DMU under evaluation are kept unchanged. For the first time, we propose two new inverse DEA models to handle resource allocation and investment analysis problems given sustainable development aspects in the presence of negative data. A case study is given for assessing sustainability of countries.     

Proposing integrated Shannon’s entropy–inverse data envelopment analysis methods for resource allocation problem under a fuzzy environment

In this study, a two-phase methodology for resource allocation problems under a fuzzy environment is proposed. In the first phase, the imprecise Shannon’s entropy method and the acceptability index are suggested, for the first time in the literature, to select input and output variables to be used in the data envelopment analysis (DEA) application. In the second step, an interval inverse DEA model is executed for resource allocation in a short run. In an effort to exemplify the practicality of the proposed fuzzy model, a real case application has been conducted involving 16 cement firms listed in Borsa Istanbul. The results of the case application indicated that the proposed hybrid model is a viable procedure to handle input–output selection and resource allocation problems under fuzzy conditions. The presented methodology can also lend itself to different applications such as multi-criteria decision-making problems.     

Three centuries of German-language philosophy journals (1765–1953): a bibliometric analysis

Scientometrics - This paper analyses three centuries of developing German-language philosophy journals, from the first journals published in 1665 to those from the first decade of post-WWII...     

What affects a patent’s value? An analysis of variables that affect technological, direct economic, and indirect economic value: An exploratory conceptual approach

The paper investigates three aspects of patent value - technological value, direct economic value, and indirect economic value. The paper suggests that we measure the technological value of a patent by looking at its number of citations, direct economic value by looking at its licensing and income from royalties, and indirect economic value by looking at its life (i.e., duration). For the research, the author’s two previous studies are deeply explored. It is found that these three aspects of patent value are positively correlated with one another. In addition, their domains overlap and interrelate. Research collaboration is the one variable found to have a significant effect on all three aspects. The field effect of electronics positively affects technological and indirect economic value, whereas research team size negatively affects technological and indirect economic value.     

Behavioural analysis of a time series–A chaotic approach

Out of the various methods available to study the chaotic behaviour, correlation dimension method (CDM) derived from Grassberger-Procaccia algorithm and False Nearest Neighbour method (FNN) are widely used. It is aimed to study the adaptability of those techniques for Indian rainfall data that is dominated by monsoon. In the present study, five sets of time series data are analyzed using correlation dimension method (CDM) based upon Grassberger-Procaccia algorithm for studying their behaviour. In order to confirm the results arrived from correlation dimension method, FNN and phase randomisation method is also applied to the time series used in the present study to fix the optimum embedding dimension. First series is a deterministic natural number series, the next two series are random number series with two types of distributions; one is uniform and another is normal distributed random number series. The fourth series is Henon data, an erratic data generated from a deterministic non linear equation (classified as chaotic series). After checking the applicability of correlation dimension method for deterministic, stochastic and chaotic data (known series) the method is applied to a rainfall time series observed at Koyna station, Maharashtra, India for its behavioural study. The results obtained from the chaotic analysis revealed that CDM is an efficient method for behavioural study of a time series. It also provides first hand information on the number of dimensions to be considered for time series prediction modelling. The CDM applied to real life rainfall data brings out the nature of rainfall at Koyna station as chaotic. For the rainfall data, CDM resulted in a minimum correlation dimension of one and optimum dimension as five. FNN method also resulted in five dimensions for the rainfall data. The behaviour of the rainfall time series is further confirmed by phase randomisation technique also. The surrogate data derived from randomisation gives entirely different results when compared to the other two techniques used in the present study (CDM and FNN) which confirms the behaviour of rainfall as chaotic. It is also seen that CDM is underestimating the correlation dimension, may be due to higher percentage of zero values in rainfall data. Thus, one should appropriately check the adaptability of CDM for time series having longer zero values.     

Genetic programming: a novel method for the quantitative analysis of pyrolysis mass spectral data

A technique for the analysis of multivariate data by genetic programming (GP) is described, with particular reference to the quantitative analysis of orange juice adulteration data collected by pyrolysis mass spectrometry (PyMS). The dimensionality of the input space was reduced by ranking variables according to product moment correlation or mutual information with the outputs. The GP technique as described gives predictive errors equivalent to, if not better than, more widespread methods such as partial least squares and artificial neural networks but additionally can provide a means for easing the interpretation of the correlation between input and output variables. The described application demonstrates that by using the GP method for analyzing PyMS data the adulteration of orange juice with 10% sucrose solution can be quantified reliably over a 0-20% range with an RMS error in the estimate of ～1%.     

Multiple regression analysis of a patent’s citation frequency and quantitative characteristics: the case of Japanese patents

Although many studies have been conducted to clarify the factors that affect the citation frequency of “academic papers,” there are few studies where the citation frequency of “patents” has been predicted on the basis of statistical analysis, such as regression analysis. Assuming that a patent based on a variety of technological bases tends to be an important patent that is cited more often, this study examines the influence of the number of cited patents’ classifications and compares it with other factors, such as the numbers of inventors, classifications, pages, and claims. Multiple linear, logistic, and zero-inflated negative binomial regression analyses using these factors are performed. Significant positive correlations between the number of classifications of cited patents and the citation frequency are observed for all the models. Moreover, the multiple regression analyses demonstrate that the number of classifications of cited patents contributes more to the regression than do other factors. This implies that, if confounding between factors is taken into account, it is the diversity of classifications assigned to backward citations that more largely influences the number of forward citations.     

Network closure, brokerage, and structural influence of journals: a longitudinal study of journal citation network in Internet research (2000–2010)

The study aims to assess journals’ structural influence in Internet research and uncover the impacts of network structures on journals’ structural influence drawing on theories of network closure and structural holes. The data of the study are the citation exchanges among 1,210 journals in Communication and other seven social scientific fields (i.e., Business, Economics/Finance, Education, Information Science, Political Science, Psychology, and Sociology) in Internet research. The top two most influential journals in Internet research are American Economic Review and Journal of Personality and Social Psychology. Journals in “Communication” field emerge to be an important source of influence in Internet research, whose mean structural influence ranks third among the eight fields, below “Business” and “Economics/Finance”, but above other five fields. Journals’ structural influences are found to grow over time and the growth rates vary across journals. Network brokerage is found to exert a significant impact on journals’ structural influence, while the impact of network closure on journals’ structural influences is not significant. The impact of network brokerage on journals’ structural influence will increase over time.     

Patent citation network analysis of core and emerging technologies in Taiwan: 1997–2008

Identifying core technologies and emerging technologies is essential for formulating national technology strategies and policies for pursuing technological competitive advantage. This study presents a quantitative method for identifying core technologies and emerging technologies in the Taiwan technological innovation system. The objective was to gain an overview of technological development in the country by analyzing patent citation networks and by identifying five core technologies and emerging technologies in Taiwan based on United States Patent and Trademark Office (USPTO) patents granted to Taiwan during 1997–2008. The findings indicate the most appropriate management of technology and innovation and the best patent strategy and technology policy that the Taiwan government should pursue. Research institutes, industries and academia are also given research directions for choosing the technologies in which they should invest resources in order to strengthen the Taiwan technological innovation system and to increase its competitive advantage in global technology.     

Developing a tailored strategy for mobile applications’ adoption across diffusion levels: A panel data analysis

This paper proposes that there should be contextual strategy development of applications’ diffusion based on the stage of mobile applications (apps) adoption already reached in a country. This is because as apps diffusion grows, the demand and supply constraints challenging the adoption of apps will change accordingly. A total of 77 countries are categorized into three clusters, Initial, Fast-Adoption, and Maturity, grouped by their adoption rates and the speeds over four-years from 2014 to 2017. With pooled and fixed-effect panel data models, this paper examines which variables out of 22 independent variables are effective in enhancing apps adoption globally. Further, by interacting two dummy clusters, Initial and Maturity with determinant variables, the study identifies the differential policy effectiveness of each determinant factor on apps adoption. The paper concludes that the three stages of apps diffusion levels have their respective effective strategy choice sets: 11 for Initial stage, 12 for Fast-adoption stage, and 13 for Maturity stage, suggesting that countries should develop their mobile apps inclusiveness strategy tailored to their context of apps adoption.     

Failure of planetary pinions in earth moving equipment—a failure analysis approach

A series of failures of planetary pinions occurred in the final drive epicyclic gearbox of large trucks used in underground mining. A metallurgical analysis indicated that failure had occurred by internal rupture of the gear. This was attributed to poor heat treatment procedures used in case hardening the gear. This had induced high residual stresses just below the case/core interface, leading to the internal rupture of the gear.     

Digital publishing and China’s core scientific journals: a position paper

In this position paper we discuss the current status of the core scientific journals in China. Based on discussions of journals’ relation to a small group of full-text database providers, open access publishing and copyright problems, we conclude that China’s digital publishing industry is not yet in a healthy state and some key issues related to revenue, digital piracy and copyright must be solved.     

CARI – a heuristic approach to machine-part cell formation using correlation analysis and relevance index

Machine-part cell formation is the process of identifying part families and the appropriate machine cell for each part family. Grouping efficacy (GE), the widely used measure for assessing the goodness of the machine-part cells depends on identification of correct part families and the appropriate machine cell for each part family. In this paper, a heuristic based on correlation analysis and relevance index is proposed for the formation of machine-part cells. Computational performance of the proposed heuristic on a set of group technology data-set available in the literature is also presented. GE of the solutions produced by the proposed heuristic is equal to the best efficacy reported in the literature for 63% of the test instances and improved the GE for 6% of the total test instances.     

The mathematical review system: does reviewer status play a role in the citation process?

This paper revisits an aspect of citation theory (i.e., citer motivation) with respect to the Mathematical Review system and the reviewer’s role in mathematics. We focus on a set of journal articles (369) published in Singularity Theory (1974–2003), the mathematicians who wrote editorial reviews for these articles, and the number of citations each reviewed article received within a 5 year period. Our research hypothesis is that the cognitive authority of a high status reviewer plays a positive role in how well a new article is received and cited by others. Bibliometric evidence points to the contrary: Singularity Theorists of lower status (junior researchers) have reviewed slightly more well-cited articles (2–5 citations, excluding author self-citations) than their higher status counterparts (senior researchers). One explanation for this result is that lower status researchers may have been asked to review ‘trendy’ or more accessible parts of mathematics, which are easier to use and cite. We offer further explanations and discuss a number of implications for a theory of citation in mathematics. This research opens the door for comparisons to other editorial review systems, such as book reviews written in the social sciences or humanities.     

Reconsidering the gold open access citation advantage postulate in a multidisciplinary context: an analysis of the subject categories in the Web of Science database 2009–2014

Since Lawrence in 2001 proposed the open access (OA) citation advantage, the potential benefit of OA in relation to citation impact has been discussed in depth. The methodology to test this postulate ranges from comparing the impact factors of OA journals versus traditional ones, to comparing citations of OA versus non-OA articles published in the same non-OA journals. However, conclusions are not entirely consistent among fields, and two possible explications have been suggested in those fields where a citation advantage has been observed for OA: the early view and the selection bias postulates. In this study, a longitudinal and multidisciplinary analysis of gold OA citation advantage is developed. All research articles in all journals for all subject categories in the multidisciplinary database Web of Science are considered. A total of 1,138,392 articles—60,566 (5.3%) OA articles and 1,077,826 (94.7%) non-OA articles—published in 2009 are analysed. The citation window considered goes from 2009 to 2014, and data are aggregated for the 249 disciplines (subject categories). At journal level, we also study the evolution of journal impact factors for OA and non-OA journals in those disciplines whose OA prevalence is higher (top 36 subject categories). As the main conclusion, there is no generalizable gold OA citation advantage, neither at article nor at journal level.     

Measuring the velocity fields of granular flows – Employment of a multi-pass two-dimensional particle image velocimetry (2D-PIV) approach

Measuring velocity fields plays a crucial role in investigating the dynamics of granular flows, which can improve the modeling of hazardous geophysical flows (e.g. avalanches and debris flows) and the control of powder flows in industrial applications. Non-invasive optical methods are invaluable tools for estimating this physical quantity at the laboratory scale. Despite the recent improvements of particle image velocimetry (PIV) algorithms, the employment of PIV to granular flows is still a non-trivial application, where there are several specific aspects to be carefully addressed. Here, we address the main challenges of granular PIV applications and systematically test the open-source window deformation multi-pass code, PIVlab [Thielicke and Stamhuis, J. Open Res. Soft., 2014], for dry granular flows in rotating drum and chute flow experiments. Three granular media (glass spheres, Ottawa sand and acetalic resin beads) with different optical properties are used as a broad test bench for validating the PIV approach. As well, comparisons between the estimations by PIVlab and those obtained by the commercial code, IDT ProVision-XS, are reported, where the advantages of the multi-pass approach are highlighted. This extensive experimental investigation allowed the evaluation of the accuracy of PIVlab in granular flow applications and also helped to assess the reliability of measurements of second-order statistics, such as the granular temperature. Finally, a guideline for setting a reliable PIV arrangement is suggested.     

Internationalization of academic journals: Is there still a gap between social and natural sciences?

In this study we compare internationalization of academic journals in six fields of science. Internationalization was investigated through journals’ concentration on publishing papers from particular countries, relationship between the geographical distributions of editors and authors, and relationship between language of publication and the geographical distribution of papers. Having analyzed more than 1,000 journals we can state that social sciences literature in the fields considered is still nationally and linguistically fragmented more than natural sciences literature, but in some cases the gap is not so big. One of the consequences concerning research output assessment is that usefulness of international databases having national disparity in coverage is still limited in social sciences.     

High efficiency a-Si:H/a-Si:H solar cell with a tunnel recombination junction and a n-type μc-Si:H layer

In this paper, a-Si:H/a-Si:H tandem solar cells have been fabricated using a plasma enhanced chemical vapor deposition. The solar cell has a structure of glass/textured-SnO₂/p-a-SiC:H/i-a-Si:H/n-μc-Si:H/p-μc-Si:H/p-a-SiC:H/i-a-Si:H/n-μc-Si:H/gallium-doped zinc oxide/Ag. Higher efficiency in a-Si:H/a-Si:H tandem solar cells can be achieved by use of a good tunnel recombination junction (TRJ) and current matching. Accordingly, solar cells with a n-μc-Si:H/p-μc-Si:H TRJ are investigated. This paper studies the influence of the thickness of the top intrinsic amorphous silicon (i-a-Si:H) layer with regard to short circuit current density and current matching between the top and the bottom cells. Experimental results with lab-fabricated samples show that the optimal thickness of the i-a-Si:H layer in the top and bottom cells is 60 and 250 nm, respectively. An initial conversion efficiency of 10.29% is achieved for the optimized a-Si:H/a-Si:H tandem solar cell. Light-induced degradation of the solar cells is about 17%.     

The lengthening of papers’ life expectancy: a diachronous analysis

The aging of scientific has generally been studied using synchronous approaches, i.e., based on references made by papers. This paper uses a diachronous model based on citations received by papers to study the changes in the life expectancy of three corpus of papers: papers from G6 and BRICS countries, papers published in Science, Nature, Physical Review and the Lancet and all papers divided into four broad fields: medical sciences, natural sciences and engineering, social sciences and arts and humanities. It shows that that: (i) life expectancy is extensively different from a corpus to another and may be either finite or infinite, meaning that the corpus would never be obsolete from a mathematical perspective; (ii) life expectancy for scientific literature has lengthened over the 1980–2000 period; (iii) life expectancy of developed countries’ (G6) literature is on average shorter than that of emerging countries (BRICS).