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Computer science is a relatively young discipline combining science, engineering, and mathematics. The main flavors of computer science research involve the theoretical development of conceptual models for the different aspects of computing and the more applicative building of software artifacts and assessment of their properties. In the computer science publication culture, conferences are an important vehicle to quickly move ideas, and journals often publish deeper versions of papers already presented at conferences. These peculiarities of the discipline make computer science an original research field within the sciences, and, therefore, the assessment of classical bibliometric laws is particularly important for this field. In this paper, we study the skewness of the distribution of citations to papers published in computer science publication venues (journals and conferences). We find that the skewness in the distribution of mean citedness of different venues combines with the asymmetry in citedness of articles in each venue, resulting in a highly asymmetric citation distribution with a power law tail. Furthermore, the skewness of conference publications is more pronounced than the asymmetry of journal papers. Finally, the impact of journal papers, as measured with bibliometric indicators, largely dominates that of proceeding papers. 相似文献
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Massimo GIUSTI Davide ORLANDI Giulia MELLE Barbara MASSA Enzo SILVESTRI Francesco MINUTO Gianni TURTULICI 《Journal of Zhejiang University. Science. B》2013,14(3):195-206
Ultrasonography(US) and the new applications US elastography(USE) and contrast-enhanced US(CEUS) are used in the screening of thyroid nodules,for which fine-needle aspiration biopsy(FNAB) is the best single diagnostic test.The aim of the study was to compare the sensitivity,specificity,positive predictive value(PPV),and accuracy of the four examinations in nodules with cytological and histological diagnoses.The study used data from US,FNAB,USE(elasticity(ELX 2/1) index),and CEUS(Peak index and time to peak(TTP) index) evaluated in 73 thyroid nodules in 63 consecutive patients likely to undergo surgery.Cytological-histological correlation was available for 38 nodules.No correlation emerged between nodule size and cytological results.A significant(P=0.03) positive correlation between cumulative US findings and cytological results was found.In addition,significant correlations between cumulative US findings and cytology(P=0.02) and between cumulative US findings and histology(P<0.0001) were found.US showed the best specificity and PPV,and FNAB the best sensitivity.There was no significant difference in the ELX 2/1 index,Peak index,or TTP index among nodules subdivided according to cytological scores.No significant correlation was found between ELX 2/1 index,Peak index,and TTP index,on the one hand,and nodule size,US cumulative findings,cytology,and histology on the other hand.The sensitivity of the ELX 2/1 index was high,but its specificity was very low.The accuracy and PPV of USE were lower than those of the other procedures.Only the correlation between Peak index and cumulative US findings reached a value close to significance.Our ultimate aim is to minimise unnecessary thyroidectomy.US and FNAB continue to play a central diagnostic role.The use of a US score showed high specificity and PPV.The specificity of FNAB was low in this selected series because of the numbers of indeterminate cytological responses.USE and CEUS are innovative techniques that need to be standardized.The ELX 2/1 index,Peak index,and TTP index seem to be unrelated to histology.The best statistical data on USE and CEUS concerned their sensitivity and PPV,respectively.At present,USE and CEUS are too time-consuming and of limited utility in selecting patients for surgery. 相似文献
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Marcello Carrozzino Nicoletta Bruno Massimo Bergamasco 《Journal of Cultural Heritage》2013,14(2):146-155
In the last few years the improved performances of graphics hardware and the growing availability of broadband internet connections have eventually led to effectively adding a third dimension to web interfaces, achieving what is commonly referred to as Web3D. Nevertheless, these technologies are not yet widespread, especially in the cultural sector, for at least two factors: technological limitations, mostly in the lack of coherent and effective metaphors to visualize and interact with digital cultural assets using the third-dimension as an added value rather than as a stylish gadget, and communication issues, as, despite the principles stated in the London Charter aimed at ensuring technical and intellectual rigor for the digital visualization of cultural heritage, a proper way to deal with relevant and sustainable 3D information is not yet completely established. For this reason this paper focuses on identifying and analyzing the aspects that may contribute to a more efficient use of Web3D technologies to access cultural content, in order to set up a set of development standards aiming to encourage web-based learning and guaranteeing systems accessible and usable by the widest possible audience. 相似文献
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Giuseppe Lippi Giuseppe Banfi Massimo Franchini Gian Cesare Guidi 《Journal of sports sciences》2013,31(5):441-442
Abstract Doping in sports is commonplace. The prevention of harm to the athlete, the guarantee of fair play, and a level playing field for all competitors are the basis of the current anti-doping strategies. As healthcare systems are forced to allocate increasing resources to prevent and treat the prevailing pathologies worldwide, funding for anti-doping campaigns will necessarily be restricted. Ideally, additional resources should be devoted to increasing the number of athletes tested, the panels of tests used, and the frequency of out-of-competition controls. Since doping prevention cannot be considered a priority for most healthcare systems, such an approach is unaffordable and an alternative framework should be devised, focused primarily on harm reduction rather than fair play. The identification of abnormal deviations from reference values, regardless of pathological or artificial causes, would allow the athlete to be followed and tested using conventional laboratory tests, which are affordable to governments and healthcare systems and available to clinical laboratories. Although this strategy would not detect cheating, it would safeguard athletes' health. 相似文献
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Massimo Amadio 《Prospects》2009,39(3):293-305
This exploratory analysis of inclusive education issues in Latin America and the Caribbean is based on a series of documents
produced in the framework of the organization of the 48th session of the International Conference on Education, in particular
the National Reports presented at the Conference as well as country reports presented at preparatory meetings. The content
analysis of the materials focused on the following topics: (a) the legal and normative framework; (b) the current educational
policies; (c) the proposed or adopted approach in terms of inclusive education; (d) the main target groups; (e) inclusive
education and the curriculum; (f) the kind of indicators most frequently mentioned; and (g) problems and challenges for inclusive
education. One of the main challenges for the countries in the region is the appreciable gap between the stated principles
and vision on one side, and the actual practices of inclusive education, on the other. Thus, there is an urgent need to ensure
that policies and strategies translate into concrete actions aimed at changing the institutional practices and pedagogical
approaches in the school and the classroom. 相似文献
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Based on PISA 2009 data, this article studies the relationship between students’ computer use and their achievement in reading, mathematics and science in 23 countries. After having categorised computer use into a set of different activities according to the skills they involve, we correlate students’ PISA test-scores with an index capturing the intensity of use for each of these activities and with the total number of activities they perform. Overall, we find that students’ PISA test scores in reading, mathematics and science increase with the intensity of computer use for Gaming activities while they decrease with the intensity of computer use for activities that are more related with school curricula (i.e. Communication and Collaboration activities; Technical Operations/Info Retrieval activities; Creation of Content and Knowledge Problem Solving activities). However, the number of activities (and hence the diversification of activities), irrespective of the intensity of computer use, is positively correlated with students’ proficiency in all three PISA domains in the vast majority of countries, indicating that computers breadth of use, as opposed to intensity of use in a given activity, has some positive effect on students’ PISA test scores. 相似文献
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This paper examines the within-industry diversification of software small and medium enterprises that collaborate with the open source software community (OSS SMEs). In doing so, it offers new insights into the association between open innovation and diversification. We rely on arguments inspired by the literature and evidence collected through interviews with OSS SMEs’ top managers to investigate factors that favor or hinder within-industry diversification. First, in line with the mainstream diversification literature, we focus attention on the role of firm size. Second, in the spirit of the open innovation research, we concentrate on the mechanisms that OSS SMEs put in place to get access to the external resources of the OSS community. Econometric evidence on 100 European OSS SMEs shows that firm size is negatively associated to within-industry diversification, while OSS SMEs that have contributed to a larger number of OSS projects have a more diversified portfolio of software products. Furthermore, we provide preliminary evidence that the practice of authorizing firm programmers to contribute autonomously to OSS projects of their own choice during working hours may be positively associated to within-industry diversification only if OSS SMEs possess adequate internal technological resources. 相似文献
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This work analyses the effect of public subsidies on firms’ investments and investment–cash flow sensitivity in a longitudinal sample of 288 Italian unlisted non-venture capital backed owner-managed new-technology-based firms (NTBFs), observed over a 15-year period from 1994 to 2008. Seventy five of these firms received one or more public subsidies in the observation period. We use an error correction model (ECM) specification and system generalised method of moment (GMM) techniques that take into account the endogeneity of public subsidies. First, we find that the investments of small NTBFs are sensitive to internal cash flows, while those of large NTBFs are not. Receipt of public subsidies by small NTBFs results in an increased investment rate and a reduced investment–cash flow sensitivity, in the immediately following year. We interpret these results as an indication of the relaxation of financial constraints. Moreover, while the increase in the investment rate does not persist in the long run, the dependence of investments on cash flow remains negligible after receipt of the first public subsidy. These results support the view that public subsidies can help small NTBFs in persistently removing the financial constraints that bind their investment activity. 相似文献