130,524 research outputs found
Modelling of the electron density height profiles in the mid-latitude ionospheric D-region
No full textA new mid-latitude D-region (50-105 km) model of the electron density is presented obtained on the basis of a full wave theory and by a trial-and-error inversion method. Daytime (at different solar zenith angles) absorption measurements by A3-technique made in Bulgaria yielded data with the aid of which the seasonal and diurnal courses of the Ne(h)-profiles were derived. Special attention is drawn to the event diurnal asymmetry, or uneven formation of the ionosphere as a function of insulation. The latter is probably connected with the influence of the diurnal fluctuations in the local temperature on the chemistry involved in the electron loss rate, as well as the diurnal variations of the main ionizing agent (NO) in the D-region. That is why the Ne(h)-profiles in the midlatitude D-region are modelled separately for morning and afternoon hours.JCR Journalope
But Then There Were also Such Bulgarians: A Bibliography for the Teacher, Enlightener and Statesman Nestor Markov
No full textThis is a review article on the book [1]. The original text is published in Bulgarian in [2].В [1]В В Mladenova, Maria. Nestor Markov 1836-1916. Biobibliography, Pleven, 2016 В (in Bulgarian).[2]В Pancheva, Tsvetanka. But then there were also such Bulgarians: A Bibliography for the Teacher, Enlightener and Statesman Nestor Markov. В In: Blagoeva, D. (Ed.), Nestor Markov and his contribution to the lexicography and education, Proceedings of the Jubilee Science Session dedicated to the 180th anniversary of the birth of Nestor Markov, Sofia, 2016 (in Bulgarian).</jats:p
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
As relativas livres em português brasileiro e os requerimentos de compatibilidade
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão. Programa de Pós-Graduação em LinguisticaEste trabalho é dedicado ao estudo do funcionamento das relativas livres do português brasileiro sob o escopo de estudos gerativistas como os de Bresnan & Grimshaw (1978), Groos e Van Riemsdijk (1981), Hirschbüher & Rivero (1983), Izvorski (1996), Caponigro (2002), entre outros. A idéia básica é que nas relativas livres o pronome relativo-wh embute o que seria o núcleo nominal de uma relativa com núcleo e, por isso, somente pronomes-wh com essa capacidade de incorporação podem iniciar uma relativa livre. Além disso, o pronome relativo-wh tem um duplo papel: respeitar os requisitos de caso e/ou categoria de um núcleo da sentença matriz e da sentença encaixada simultaneamente (chamado de requerimentos de Compatibilidade). Assim, por meio do estudo das relativas livres objetivamos: a) distinguir uma relativa livre de uma interrogativa encaixada e de uma completiva; b) estabelecer que posições sintáticas uma relativa livre pode desempenhar; c) observar como ocorre o requerimento de compatibilidade nas línguas, com especial atenção ao português brasileiro; d) verificar por que o requerimento de compatibilidade não ocorre nas chamadas #relativas livres infinitivas#; e, e) delimitar, entre três hipóteses (Hipótese do Núcleo, Hipótese do Comp e Hipótese do complemento de D) a melhor para a análise dos dados do português brasileiro. Com esse estudo constatamos, entre outros aspectos, que os pronomes relativos que, qual e cujo não iniciam uma relativa livre, pois não conseguem embutir o que seria o um núcleo nominal de uma relativa com núcleo. Ainda, verificamos que os pronomes relativos são DPs, porém quando er DP ou PP. Em adição, constatamos que as chamadas #relativas livres infinitivas# que não respeitam os requerimentos de compatibilidade na verdade não são relativas livres, mas sim relativas com núcleo. This work is concerning the study of the free relatives in Brazilian Portuguese based on generative studies from Bresnan & Grimshaw (1978), Groos and Van Riemsdijk (1981), Hirschbüher & Rivero (1983), Izvorski (1996), Caponigro (2002), among others. The basic idea is that the relative pronoun of free relatives incorporates what would be the head of a headed relative. Thus only wh-pronouns with this incorporation ability can initiate a free relative. Furthermore, the wh-relative pronoun has a dual role: comply with the requirements of case and/or category of the matrix and embedded sentence simultaneously (called Matching Requirements). Thus, through free relative#s study we aim at: a) distinguishing free relative from embedded questions and embedded clauses; b) establishing syntactic positions that a free relative can play; c) observing how the matching requirement occurs in languages with special attention to Brazilian Portuguese; d) verifying why the matching requirement does not occur in the so-called 'infinitival free-relatives'; and e) defining, among three hypothesis (Head Hypothesis, Comp Hypothesis and D-complement Hypothesis) the best for the analysis of data from the Brazilian Portuguese. Due to this study, we noticed, among other aspects, that the relative pronouns que, qual and cujo do not start a free relative because they are unable to embed what would be a head of a headed relative. Furthermore, we noticed that the relative pronouns are DPs, but when they are in an AdvP position they are ambiguous between being DP or PP. We also noticed that the so-called #infinitival free relatives# that do not respect the matching requirement actually are not free relative, but headed relative
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Mesosphere/lower thermosphere prevailing wind model
No full textCopyright © 2004 COSPAR. Published by Elsevier Ltd.The mesosphere/lower thermosphere (MLT) wind data from the 46 ground-based (GB) MF and meteor radar (MR) stations, located at the different latitudes over the globe, and the space-based (SB) HRDI data were used for constructing of the empirical global climatic 2-D prevailing wind model at 80–100 km heights for all months of the year. The main data set is obtained during 1990–2001 period. It is shown that the three datasets (MF, MR, HRDI) are mainly well correlated. However, a certain systematic bias between the GB and SB data at 96 km exists, as well as that between the MF and MR data higher 88 km. Simple correction factors are proposed to minimize these biases. The 2-D distant-weighted least-square interpolation procedure for some arbitrary collection of points was used for drawing model contour plots. The model is available in the computer readable form and may be used for construction of the new CIRA model.Yu. Portnyagin, T. Solovjova, E. Merzlyakov, J. Forbes, S. Palo, D. Ortland, W. Hocking, J. MacDougall, T. Thayaparan, A. Manson, C. Meek, P. Hoffmann, W. Singer, N. Mitchell, D. Pancheva, K. Igarashi, Y. Murayama, Ch. Jacobi, D. Kuerschner, A. Fahrutdinova, D. Korotyshkin, R. Clark, M. Taylor, S. Franke, D. Fritts, T. Tsuda, T. Nakamura, S. Gurubaran, R. Rajaram, R. Vincent, S. Kovalam, P. Batista, G. Poole, S. Malinga, G. Fraser, D. Murphy, D. Riggin, T. Aso and M. Tsutsumihttp://www.elsevier.com/wps/find/journaldescription.cws_home/644/description#descriptio
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Scholarly Communication and Publishing Lunch and Learn Talk #11: The ULS Open Access Author Fee Fund
No full textAt the May 2014 talk, you will learn about the ULS Open Access Author Fee Fund--what it is, why we do it, how it works, and how the program is going so far
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