1,720,964 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    The 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

    Full text link
    “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

    Full text link
    We 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

    Morphogenesis of hypogenic caves

    No full text
    Hypogenic speleogenesis is the formation of solution-enlarged permeability structures by waters ascending to a cave-forming zone from below in leaky confined conditions, where deeper groundwaters in regional or intermediate flow systems interact with shallower and more local groundwater flow systems. This is in contrast to more familiar epigenic speleogenesis which is dominated by shallow groundwater systems receiving recharge from the overlying or immediately adjacent surface.Hypogenic caves are identified in various geological and tectonic settings, formed by different dissolutional mechanisms operating in various lithologies. Despite these variations, resultant caves demonstrate a remarkable similarity in patterns and meso-morphology, which strongly suggests that the hydrogeologic settings were broadly identical in their formation. Hypogenic caves comm demonstrate a characteristic suite of cave morphologies resulting from rising flow across the cave-forming zone with distinct buoyancy-dissolution components. In addition to hydrogeological criteria (hydrostratigraphic position, recharge–discharge configuration and flow pattern viewed from the perspective of the evolution of a regional groundwater flow system), morphogenetic analysis is the primary tool in identifying hypogenic caves.Cave patterns resulting from ascending transverse speleogenesis are strongly guided by the permeability structure in a cave formation. They are also influenced by the discordance of permeability structure in the adjacent beds and by the overall hydrostratigraphic arrangement. Three-dimensional mazes with multiple storeys, or complex 3-D cave systems are most common, although single isolated chambers, passages or crude clusters of a few intersecting passages may occur where fracturing is scarce and laterally discontinuous. Large rising shafts and collapse sinkholes over large voids, associated with deep hydrothermal systems, are also known.Hypogenic caves include many of the largest, by integrated length and by volume, documented ca

    The Karst Paradigm: Changes, Trends and Perspectives

    Full text link
    The paper examines representative definitions of karst (21), and discusses some concepts that influenced the modern understanding of the phenomenon. Several trends are discussed that took karst science beyond the limits of the traditional paradigm of karst. Dramatic progress in studies of speleogenesis plays the most significant role in changes taking place in the general understanding of karst. Also important is an adoption of the broad perspective to karst evolution which goes beyond the contemporary geomorphologic epoch and encompasses the entire life of a geological formation. Speleogenesis is viewed as a dynamic hydrogeological process of self-organization of the permeability structure in soluble rocks, a mechanism of the specific evolution of the groundwater flow system. The result is that these systems acquire a new, "karstic", quality and more complex organization. Since almost all essential attributes of karst owe their origin to speleogenesis, the latter is considered as the primary mechanism of the formation of karst. Two fundamental types of speleogenesis, hypogene and epigene, differentiate mainly due to distinct hydrodynamic characteristics of the respective groundwater flow systems: (1) of layered aquifer systems and fracture-vein flow systems of varying depths and degrees of confinement, and (2) of hydrodynamically open, near-surface unconfined systems. Accordingly, two major genetic types of karst are distinguished: hypogene and epigene. They differ in many characteristics, notably in relationships with the surface, hydrogeological behaviour, groundwater quality, and the areas of practical importance and approaches to solving karst-related issues. Although views on essential attributes of karst have been clearly changing, this was not reflected in definitions of the notion which are in broad use in the earth-science literature. A refined approach is suggested to the notion of karst in which it is viewed as a groundwater (fluid) flow system of a specific kind, which has acquired its peculiar properties in the course of speleogenesis.Kraška paradigma: spremembe, trendi in perspektiveDokument obravnava reprezentativne definicije krasa (21) in obravnava nekatere koncepte, ki so vplivali na sodobno razumevanje tega pojava. Razpravlja o več trendih, ki so popeljali krasoslovje preko meja tradicionalne paradigme krasa. Dramatični napredek v speleogenetskih raziskavah je igral najpomembnejšo vlogo pri spremembah, ki so se zgodile pri splošnem razumevanju krasa. Prav tako je za razvoj krasoslovja pomembno sprejetje široke perspektive, ki presega sodobno geomorfološko epoho in zajema celoten geološki razvoj. Speleogeneza je predstavljena kot dinamični hidrogeološki proces samoorganizacije stopnje prepustnosti posameznih struktur v topnih kamninah, to je kot mehanizem specifičnega razvoja sistema toka podzemne vode. Posledica tega je, da ti sistemi potrebujejo novo, "kraško", kakovostno in bolj kompleksno organizacijo. Ker skoraj vse bistvene značilnosti krasa izvirajo iz speleogeneze, je slednja šteta kot primarni mehanizem za nastanek krasa. Dve temeljni vrsti speleogeneze, hipogena in epigena, se razlikujeta predvsem zaradi različnih hidrodinamičnih značilnosti posameznih sistemov toka podzemne vode: (1) plastoviti vodonosni sistemi in tokovni sistemi po prelomih in žilah različnih globin in stopenj zaprtosti, ter (2) hidrodinamično odprti in plitvi sistemi. Posledično razlikujemo dva velika genetska tipa krasa: hipogeni in epigeni. Med seboj se razlikujeta v mnogih značilnostih, predvsem v odnosih s površjem, po hidrogeološkem obnašanju, kakovosti podzemne vode, ter na področjih praktičnega pomena in pristopov k reševanju vprašanj, povezanih s krasom. Čeprav so se stališča o bistvenih lastnostih krasa spreminjala, se to ni odrazilo v opredelitvi pojma, ki se na splošno uporablja v vedah o Zemlji. Pri predstavah o krasu predlagamo dodelan pristop, v katerem je poudarek na sistemu podzemne vode (tekočine) s specifičnim načinom pretakanja, ki je pridobilo svoje značilne lastnosti prav tekom speleogeneze.  

    Dispelling the Myths Behind First-author Citation Counts

    Full text link
    We 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

    Author Index

    No full text
    Nao informado

    Discrimination of the Hranice Karst waters (Czech Republic) based on the archival data

    No full text
    This chapter discusses the notion of hypogene karst, reviews its diversity and further develops the hydrogeological approach to classifying hypogene karst and its settings. Since an understanding of hypogene karst requires much deeper and broader hydrogeological and geodynamic context as compared to more familiar epigene karst, this chapter provides an overview of basic concepts about fluid dynamics and hydrodynamic zoning of the upper crust and about the influence of the mantle processes on crustal fluids. The relationships of hypogene karstification with metasomatism and other processes of fluid-induced transformations of rocks are examined. It is argued that the phenomena of the so-called ghost-rock karstification (commonly attributed to epigene settings) and cavernous decay (commonly attributed to external weathering) are manifestations of hypogene karstification and related alteration of rocks around conduits. Genetic categorization and discrimination of characteristic settings of hypogene karst are based on consideration of driving forces and conditions for fluid circulation and ascending flow in the upper crust in the context of tectonic/geodynamic positions and history of regions. Development and distribution of hypogene karst of the artesian type in gravitational flow systems of cratons are governed by the basin’s configuration, topography and hydrostratigraphy. Hypogene karst of the endogenous type is governed by the geodynamic regimes and intimately related to cross-formational fluid-conducting systems. Hypogene karst is a significant component of fluid-induced lithogenesis and plays an important role in the porosity and permeability development in many sedimentary rocks and some metamorphic rocks

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

    No full text
    We 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
    corecore