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Analisi delle metodologie per il rilevamento e la valutazione della scabrosita' superficiale del terreno agrario
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Comparison of methods for determining cloddiness in seedbed preparation
Full text linkTo determine the optimum degree of roughness of a seedbed, it is necessary to identify parameters that can quantify cloddiness. This is necessary not only within experimental boundaries, but also to check the quality of work and to objectively adjust implements. In this study, the degree of cloddiness of seedbeds was evaluated using four different methods: the sieve method; image analysis; the standard deviation of the heights defining the soil profile; and counting, in the field, clods with diameter > 40 mm. The degree of correlation between the results obtained by the different methods was also evaluated. The method based on image analysis was well correlated to the sieve method (r2 = 0.81) and can be used as an alternative for determining seedbed cloddiness . The standard deviation of the heights defining the profile can be correlated, with a fair approximation (correlation to sieve method r2 = 0.63), to the degree of cloddiness of the seedbed, although this is also influenced by factors not linked to clod size (oriented roughness). The method based on counting clods with a diameter > 40 mm is a simplification of the method based on image analysis; though its correlation to the sieve method is lower (r2 = 0.53), it lends itself to field application at the stage of adjusting implements. Furthermore, given it's simplicity, it appears to be suitable for use by extension services to objectively determine seedbed cloddiness and avoid excessive pulverising of soil. The type of implement affects, sometimes clearly, the relations between the various indexes and these variations can be explained by the way the implements operate. In particular, comparison between the sieve and the image analysis demonstrates the different distribution of clods in the vertical profile of the tilled layer; the comparison between image analysis and soil height standard deviation singles out the roughness component not caused by the dimensions of the clods. Finally an analysis of indexes technical aspects under field conditions is reported
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
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