1,720,959 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
Load capacity of the mixed bench and slab foundation. Numerical simulations and analytical calculation model
No full textThe paper presents results of a numerical investigation on load capacity of the mixed bench and slab shallow foundations (often used in the process of the modernization of the old, antique buildings, which are suffering from lack of the load capacity). The main trouble with use of existing analytical approaches is a non-unique foundation level of the bench and slab, they could even be founded on different geotechnical layers. Proposed analytical model based on Brinch Hansen (EC-7) approach could deal with such a problem. Results of 2D and 3D numerical modelling (ultimate load of the foundation) are compared to the obtained by using the proposed approach. Influence of the soil above the foundation level is also investigated. Different width to length ratios of the foundation are analyzed (from “short” to “long” foundations). Usability of the proposed analytical model in engineering practice is proved by numerical simulations; the obtained results are on the safe side with quite acceptable margin of additional safety
Modelowanie numeryczne muru oporowego z gabionów przy obciążeniu i odciążeniu
No full textMain goal of this paper is to present results of the numerical simulations of a real-scale gabion retaining wall tests. 4.5 m high wall was loaded and unloaded with water pressure, displacements of the crest of the wall were measured. Finite Element Method was used to simulate experiment and obtained results are compared with experimental ones. Usage of homogenized Coulomb-Mohr type continuum for gabions is proposed. Strength parameters of the model (cohesion and friction angle) are estimated on the base of large scale triaxial tests of the gabions and static tensile tests of the mesh. Influence of the “cut-off” condition on obtained results is analyzed. Elastic model for gabions is used for comparison of the results. Interface elements and truss joints between the gabions are used to simulate joints between gabions with limited strength. Good correlation between displacements obtained in experiment and numerical simulations was observed, especially in loading phase, so presented methodology of numerical modelling allows to model gabion retaining walls behavior close to the reality and could be used in engineering practice.Artykuł przedstawia wyniki symulacji numerycznych testów rzeczywistego muru oporowego z gabionów. Mur o wysokości 4.5 m był obciążany ciśnieniem wody i odciążany, mierzono przemieszczenia jego korony. Metoda Elementów Skończonych została wykorzystana do zasymulowania badań laboratoryjnych, porównano uzyskane wyniki z otrzymanymi doświadczalnie. Zaproponowano wykorzystanie zhomogenizowanego ośrodka typu Coulomba - Mohra do modelowania gabionów. Parametry wytrzymałościowe (kohezję i kąt tarcia wewnętrznego) oszacowano na bazie testów trójosiowych gabionów i testów statycznego rozciągania siatki. Analizowano wpływ warunku „cut-off” (braku nośności na rozciągania) na uzyskiwane wyniki. Dla porównania wykorzystano model sprężysty gabionów. Elementy kontaktowe i łączniki kratownicowe wykorzystano do zamodelowania połączeń pomiędzy gabionami o ograniczonej wytrzymałości. Zaobserwowano dobrą zgodność obliczonych numerycznie i pomierzonych laboratoryjnie przemieszczeń (szczególnie w fazie obciążenia), tak więc zaprezentowana metodologia pozwala na bliskie rzeczywistości zamodelowanie zachowania się konstrukcji z gabionów i może być wykorzystywana w praktyce inżynierskiej
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
Excavations in the vicinity of the antiflood embankments – calculating issues
No full textAccording to Polish law, it is prohibited to perform excavations or locate buildings closer than 50 m from the embankment. In order to obtain exemption from this ban, filtration and stability analysis of the embankment and excavation in the flood conditions have to be performed. This paper presents results of the numerical investigations on interactions between excavations and embankment. Complex nature of the problem is presented. Methodology of numerical simulations and real case examples are described
Osuwisko spowodowane małym wykopem – symulacje numeryczne
No full textThe main objective of this work is to present the results of numerical simulations of the landslide triggered by small excavation. In south-eastern Poland in 2019, during excavation for a gas pipeline (relatively small – maximal depth 2.7 m), a landslide was observed. Length of the landslide was about 80 m, width about 50 m, maximal depth 6.5 m. Excavation was partially buried. Observed cracks of the terrain surface were wide, up to 0.8 m. Stability of the landslide was analyzed using the proportional reduction of the soil strength parameters (c-fi reduction) algorithm with the use of ZSoil.PC Finite Element Method (FEM) system. Stability analysis of the slope before and after excavation was performed, together with analysis of the tendency of the landslide to propagate upwards. The obtained stability loss modes were compared with the results of the field observations and a good correlation was noticed. Hypothesis that a landslide was triggered by small excavation was proved (although reasonable margin of safety was obtained for state before excavation, stability factor SF = 1.60). Use of residual soil strength parameters (instead of peak ones) and activation of cut-off (no tension) condition are advised. Presented methodology is open and can be used in engineering practice.Artykuł przedstawia wyniki symulacji numerycznych osuwiska wywołanego przez mały wykop. W południowo-wschodniej Polsce w 2019 r. w czasie wykopów związanych z wykonywaniem gazociągu (niewielkich, o maksymalnej głębokości 2.7 m) doszło do powstania osuwiska. Długość osuwiska wynosiła około 80 m, szerokość około 50 m, maksymalna głębokość 6.5 m. Wykop został częściowo zasypany przez osuwający się grunt. Zaobserwowano szerokie pęknięcia powierzchni terenu, o szerokości do 80 cm. Stateczność osuwiska analizowano z wykorzystaniem metody proporcjonalnej redukcji parametrów wytrzymałościowych gruntu (c-φ redukcji). Obliczenia wykonano za pomocą systemu Metody Elementów Skończonych (MES) ZSoil.PC. Analizowano stateczność zbocza przed i po wykonaniu wykopu oraz tendencję osuwiska do dalszej propagacji w górę stoku. Uzyskane mechanizmy utraty stateczności porównano z wynikami obserwacji terenowych i stwierdzono dobrą zgodność. Hipoteza, że osuwisko zostało spowodowane przez mały wykop została potwierdzona (mimo że w stanie przed wykonaniem wykopu zbocze posiadało wysoki współczynnik stateczności wynoszący 1.60). Zaleca się wykorzystywanie w obliczeniach stateczności rezydualnych wartości parametrów wytrzymałościowych gruntu oraz wykorzystanie warunku cut-off (oznaczającego brak wytrzymałości gruntu na rozciąganie). Prezentowana metodologia może być wykorzystana w praktyce inżynierskiej
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