1,720,973 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Fifteen New Discriminant-function-based Multi-dimensional Robust Diagrams For Acid Rocks And Their Application To Precambrian Rocks
No full textFor the discrimination of four tectonic settings of island arc, continental arc, within-plate (continental rift and ocean island together), and collision, we present three sets of new diagrams obtained from linear discriminant analysis of natural logarithm transformed ratios of major elements, immobile major and trace elements, and immobile trace elements in acid magmas. The use of discordant outlier-free samples prior to linear discriminant analysis had improved the success rates by about 3% on the average. Success rates of these new diagrams were acceptably high (about 69% to 97% for the first set, about 69% to 99% for the second set, and about 60% to 96% for the third set). Testing of these diagrams for acid rock samples (not used for constructing them) from known tectonic settings confirmed their overall good performance. Application of these new diagrams to Precambrian case studies provided the following generally consistent results: a continental arc setting for the Caribou greenstone belt (Canada) at about 3000. Ma, São Francisco craton (Brazil) at about 3085-2983. Ma, Penakacherla greenstone terrane (Dharwar craton, India) at about 2700. Ma, and Adola (Ethiopia) at about 885-765. Ma; a transitional continental arc to collision setting for the Rio Maria terrane (Brazil) at about 2870. Ma and Eastern felsic volcanic terrain (India) at about 2700. Ma; a collision setting for the Kolar suture zone (India) at about 2610. Ma and Korpo area (Finland) at about 1852. Ma; and a within-plate (likely a continental rift) setting for Malani igneous suite (India) at about 745-700. Ma. These applications suggest utility of the new discrimination diagrams for all four tectonic settings. In fact, all three sets of diagrams were shown to be robust against post-emplacement compositional changes caused by analytical errors, element mobility related to low or high temperature alteration, or Fe-oxidation caused by weathering. © 2013 Elsevier B.V.168-169113123Agrawal, S., Discrimination between late-orogenic, post-orogenic, and anorogenic granites by major element compositions (1995) Journal of Geology, 103, pp. 529-537Agrawal, S., Geochemical discrimination diagrams: a simple way of replacing eye-fitted boundaries with probability based classifier surfaces (1999) Journal of the Geological Society of India, 54, pp. 335-346Agrawal, S., Verma, S.P., Comment on "Tectonic classification of basalts with classification trees" by Pieter Vermeesch (2006) (2007) Geochimica et Cosmochimica Acta, 71, pp. 3388-3390Agrawal, S., Guevara, M., Verma, S.P., Discriminant analysis applied to establish major-element field boundaries for tectonic varieties of basic rocks (2004) International Geology Review, 46, pp. 575-594Agrawal, S., Guevara, M., Verma, S.P., Tectonic discrimination of basic and ultrabasic rocks through log-transformed ratios of immobile trace elements (2008) International Geology Review, 50, pp. 1057-1079Aitchison, J., (1986) The Statistical Analysis of Compositional Data, , Chapman and Hall, London, New York, (416 pp.)Barnett, V., Lewis, T., (1994) Outliers in Statistical Data, , John Wiley & Sons, Chichester, (584 pp.)Cassidy, M., Taylor, R.N., Palmer, M.R., Cooper, R.J., Stenlake, C., Trofimovs, J., Tracking the magmatic evolution of island arc volcanism: insights from a high-precision Pb isotope record of Montserrat, Lesser Antilles (2012) Geochemistry, Geophysics, Geosystems, 13, pp. 1-19Deering, C.D., Gravley, D.M., Vogel, T.A., Cole, J.W., Leonard, G.S., Origins of cold-wet-oxidizing to hot-dry-reducing rhyolite magma cycles and distribution in the Taupo Volcanic Zone, New Zealand (2010) Contributions to Mineralogy and Petrology, 160, pp. 609-629Déruelle, B., Moreau, C., Nkoumbou, C., Kambou, R., Lissom, J., Njonfang, E., Ghogomu, R.T., Nono, A., The Cameron line: a review (1991) Magmatism in Extensional Structural Settings, pp. 274-327. , Springer Verlag, Berlin, Germany, A.B. 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Lubala (Eds.)Eby, G.N., Kochhar, N., Geochemistry and petrogenesis of the Malani igneous suite, northern peninsular India (1990) Journal of Geological Society of India, 36, pp. 109-130Grib, E.N., Leonov, V.L., Perepelov, A.B., The Karymskii Volcanic Center: volcanic rock geochemistry (2009) Journal of Volcanology and Seismology, 3, pp. 367-387Hollings, P., Kerrich, R., Trace element systematics of ultramafic and mafic volcanic rocks from the 3Ga North Caribou greenstone belt, northwestern Superior Province (1999) Precambrian Research, 93, pp. 257-279Kerrich, R., Manikyamba, C., Contemporaneous eruption of Nb-enriched basalts - K-adakites-Na-adakites from the 2.7Ga Penakacherla terrane: implications for subduction zone processes and crustal growth in the eastern Dharwar craton, India (2012) Canadian Journal of Earth Sciences, 49, pp. 615-636Krogstad, E.J., Hanson, G.N., Rajamani, V., Sources of continental magmatism adjacent to the late Archean Kolar Suture Zone, south India: distinct isotopic and elemental signatures of two late Archean magmatic series (1995) Contributions to Mineralogy and Petrology, 122, pp. 159-173Le Bas, M.J., Le Maitre, R.W., Streckeisen, A., Zanettin, B., A chemical classification of volcanic rocks based on the total alkali-silica diagram (1986) Journal of Petrology, 27, pp. 745-750Maheshwari, A., Sial, A.N., Coltorti, M., Chittora, V.K., Cruz, M.J.M., Geochemistry and petrogenesis of Siwana peralkaline granites, west of Barmer, Rajasthan, India (2001) Gondwana Research, 4, pp. 87-95Maheshwari, A., Coltori, M., Rajput, S.K., Verma, M., Geochemical characteristics, discrimination and petrogenesis of neoproterozoic peralkaline granites, Barmer District, SW Rajasthan, India (2009) International Geology Review, 51, pp. 1103-1120Middlemost, E.A.K., Iron oxidation ratios, norms and the classification of volcanic rocks (1989) Chemical Geology, 77, pp. 19-26Mohan, M.R., Piercey, S.J., Kamber, B.S., Sarma, D.S., Subduction related tectonic evolution of the Neoarchean eastern Dharwar Craton, southern India: new geochemical and isotopic constraints Precambrian Research., , in pressOliveira, M.A., Dall'Agnol, R., Althoff, F.J., Leite, A.A.S., Mesoarchean sanukitoid rocks of the Rio Maria Granite-Greenstone Terrane, Amazonian craton, Brazil (2009) Journal of South American Earth Sciences, 27, pp. 146-160Oliveira, E.P., McNaughton, N.J., Armstrong, R., Mesoarchaean to Palaeoproterozoic growth of the northern segment of the Itabuna-Salvador-Curaçá orogen, São Francisco craton, Brazil (2010) Geological Society of America, 338, pp. 263-286Pearce, J.A., Harris, N.B.W., Tindle, A.G., Trace element discrimination diagrams for the tectonic interpretation of granitic rocks (1984) Journal of Petrology, 25, pp. 956-983Rollinson, H.R., (1993) Using Geochemical Data: Evaluation, Presentation, Interpretation, , Longman Scientific Technical, Essex, (344 pp.)Schmitz, M.D., Smith, I.E.M., The petrology of the Rotoiti eruption sequence, Taupo Volcanic Zone: an example of fractionation and mixing in a rhyolitic system (2004) Journal of Petrology, 45, pp. 2045-2066Vaisanen, M., Eklund, O., Lahaye, Y., O'Brien, H., Frojdo, S., Hogdahl, K., Lammi, M., Intra-orogenic Sveconfennian magmatism in SW Finland constrained by LA-MC-ICP-MS zircon dating and geochemistryñ (2012) GFF, 134, pp. 99-114Verma, S.K., Pandarinath, K., Verma, S.P., Statistical evaluation of tectonomagmatic discrimination diagrams for granitic rocks and proposal of new discriminant-function-based multi-dimensional diagrams for acid rocks (2012) International Geology Review, 54, pp. 325-347Verma, S.P., Sixteen statistical tests for outlier detection and rejection in evaluation of International Geochemical Reference Materials: example of microgabbro PM-S (1997) Geostandards Newsletter: The Journal of Geostandards and Geoanalysis, 21, pp. 59-75Verma, S.P., Statistical evaluation of bivariate, ternary and discriminant function tectonomagmatic discrimination diagrams (2010) Turkish Journal of Earth Sciences, 19, pp. 185-238Verma, S.P., Geochemometrics (2012) Revista Mexicana de Ciencias Geológicas, 29, pp. 276-298Verma, S.P., Application of multi-dimensional discrimination diagrams and probability calculations to acid rocks from Portugal and Spain (2012) Comunicações Geológicas, 99, pp. 79-93Verma, S.P., Agrawal, S., New tectonic discrimination diagrams for basic and ultrabasic volcanic rocks through log-transformed ratios of high field strength elements and implications for petrogenetic processes (2011) Revista Mexicana de Ciencias Geológicas, 28, pp. 24-44Verma, S.P., Díaz-González, L., Application of the discordant outlier detection and separation system in the geosciences (2012) International Geology Review, 54, pp. 593-614Verma, S.P., Rivera-Gómez, M.A., New computer program TecD for tectonomagmatic discrimination from discriminant function diagrams for basic and ultrabasic magmas and its application to ancient rocks Journal of Iberian Geology., , in pressVerma, S.P., Rivera-Gómez, M.A., submitted for publication Computer programs for the classification and nomenclature of igneous rocks, , Episodes, (waiting decision)Verma, S.P., Verma, S.K., First fifteen probability-based multi-dimensional tectonic discrimination diagrams for intermediate magmas and their robustness against post-emplacement compositional changes and petrogenetic processes Turkish Journal of Earth Sciences, , in pressVerma, S.P., Torres-Alvarado, I.S., Sotelo-Rodríguez, Z.T., SINCLAS: standard igneous norm and volcanic rock classification system (2002) Computers & Geosciences, 28, pp. 711-715Verma, S.P., Torres-Alvarado, I.S., Velasco-Tapia, F., A revised CIPW norm (2003) Schweizerische Mineralogische und Petrographische Mitteilungen, 83, pp. 197-216Verma, S.P., Guevara, M., Agrawal, S., Discriminating four tectonic settings: five new geochemical diagrams for basic and ultrabasic volcanic rocks based on log-ratio transformation of major-element data (2006) Journal of Earth System Science, 115, pp. 485-528Wolde, B., Asres, Z., Desta, Z., Gonzalez, J.J., Neoproterozoic zirconium-depleted boninite and tholeitic series rocks from Adola, southern Ethiopia (1996) Precambrian Research, 80, pp. 261-27
EXPERIMENTAL INVESTIGATIONS ON VIBRATIONS AND ACOUSTIC NOISE OF AN INDUCTION MOTOR
Get PDFElectric motors are important machines as they are widely used in industry.
Unfortunately, they produce annoying noise which is a big concern. In order to obtain
better understanding of vibrations and noise produced by induction motors, extensive
investigations have been conducted on a specially designed test motor. It is well known that electromagnetic forces cause vibrations of the motor, producing radiated acoustic noise. The physical interpretations drawn from the experimental results reported in this thesis are beneficial to correlate the vibrations and the radiated noise.
ISO and IEEE standards stipulate the procedures for conducting acoustic measurements so that reliable, reproducible results with specified level of accuracy can be obtained. ISO and IEEE standards describe suitable methods and measuring systems in order to arrange all the investigations in such a way that a systematic analysis can be performed. Relevant discussions with reference to these standards are presented in the thesis.
After discussing the noise problems of induction motors encountered in industry
and the workplace, the basic definitions and terms used for sound measurements are
provided. Brief descriptions of various instruments used for vibration and noise
measurements are also given.
Before proceeding with the actual experimental investigations, it is essential to
summarize the theoretical analyses of electromagnetic fields and electromagnetic forces produced in an induction motor. Harmonic analysis of the stator current, spectral analysis of the induced voltage in stator search-coils, and noise measurements using a sound-level-meter form the preliminary investigations which bridge theoretical analyses and detailed experimental investigations.
Vibration measurements are fundamental in providing information on spectral
distributions of noise. Mode-shape measurements show the stator deformations under electromagnetic forces, which are created by the three-phase currents. The effects of impressed voltage and the change ofload on vibration levels are also investigated.
Noise measurements are conducted in both an ordinary laboratory and an anechoic chamber. The ordinary laboratory is similar to the practical workplace, which is neither a free-field nor a reverberant-room. The measurement results obtained in the
laboratory are of practical importance. The anechoic chamber provides the free-field
condition, where measurements corresponding to various standards are required. The
results obtained in both ordinary laboratory and anechoic chamber are compared to
produce useful practical information about the noise level change caused by sound
fields. Also, the directional characteristics are carefully studied in the anechoic
chamber. The results obtained are very helpful in understanding the nature of the noise radiation patterns of the motor
ANALYSES OF SQUIRREL-CAGE WINDINGS WITH PARTICURLAR REFERENCE TO THE DEVELOPMENT OF A HIGHTLY STABLE RELUCTANCE MACHINE
No full textReluctance machines have been very successfully used in a wide variety of applications where their special features have made them a natural or even an inevitable choice. For the last few years, a number of investigators have been engaged in improving the overall performance of such machines. This has been achieved by adopting several rotor configurations which are different from the conventional reluctance rotor. In order to justify the choice of conventional reluctance machines for the studies presented in the thesis, a general survey of various types of reluctance machines is presented.
One of the main objectives of the thesis is to show that the performance is a conventional reluctance machine can be enhanced to a great extent by changing the distribution of the rotor bars. A simple and realistic method of analysis of developed for investigating the effects of the distribution of the rotor bars on the asynchronous, the dynamic stability and the transient behavior of conventional reluctance machines. The method enables a design engineer to obtain the most suitable arrangement o the rotor vars at the design stage. In light of the asynchronous, the transient and the stability performance of a specific machine, two suitable arrangements are recommended for the rotor bars. These arrangements are characterized by the outstanding features of minimum amplitude of the pulsating torque, smooth torque-slip characteristics, stable operation at all frequencies, moments of inertia and operating loads and better capability of pulling-into-synchronism.
A considerable part of the thesis is devoted to the studies related to the consideration of the phenomenon of skin-affect during the transient operation of electrical machines. The general partial differential equations of the magnetic vector potential is derived on the basis of two-dimensional analysis. With the help of the principles of finite-difference method, numerical techniques are presented for solving the field equations obtained from both two- and single-dimensional analyses. The techniques are used for investigating the transient skin-affect of a deep bar embedded in a slot. They analysis and the accuracy of the technique developed are verified through comparisons between numerical and analytical results.
Incorporating the skin-effect on the transient analysis of electrical machines necessitates the development of a novel approach for the analysis of squirrel-cage windings. This involves the derivation of voltage an torque equations based on a new choice of the rotor circuits of a reluctance machine. The rotor voltage equations are formulated in such a way that the transient skin-effect can be easily incorporated in the analysis. A sound per-unit system is also presented. The application of the novel approach is demonstrated by considering a reluctance machine having four bars per pole. Further, the transient performance of a machine having one of the two recommended designs is investigated with and without the consideration of the skin-effect of bars and ending segments.
Although the analyses presented in the thesis are devoted to the case of reluctance machines, their main features can be applied to synchronous machines as well as to induction machines having integral numbers of bars per pole
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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