1,723,579 research outputs found
Manejo integrado del ma?z
No full textEl ma?z como alimento b?sico, posee una gran importancia en Venezuela y el
mundo ya que por sus magn?ficas ventas se coloca en una de las primeras filas
de la econom?a, es una planta monoica anual, de tallos altos y rectos de hojas
grandes y lanceolada
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Perturbation by differences of unbounded potentials
No full textHansen W, Ma Z. Perturbation by differences of unbounded potentials. Mathematische Annalen. 1990;287(4):553-569
Verification of Pattern-Pattern Diagnosability in Partially Observed Discrete Event Systems
Full text linkThis work studies a new notion of diagnosability called the pattern-pattern diagnosability in discrete event systems modeled by partially observable finite state automata. Suppose that in the system there are some sequences of events that are undesirable to happen, which we call the fault pattern. We want to determine whether the occurrence of the fault pattern can be determined before some sequences - -which we call the critical pattern and may cause fatal consequences after the fault pattern - are completed. Both fault and critical patterns are assumed to be regular and, hence, are described by the languages accepted by finite automata. We propose a novel notion of pattern-pattern diagnosability (PP-diagnosability), which requires that the occurrence of a fault pattern can always be detected before the completion of a critical pattern thereafter. The properties of PP-diagnosability, and the relations between PP-diagnosability and conventional diagnosability are studied. Then, we propose a method to verify PP-diagnosability using a structure called the pattern-pattern verifier. The complexity of the proposed method is polynomial in the number of states of the plant and the two pattern automata
Petri net controllers for Generalized Mutual Exclusion Constraints with floor operators
No full textIn this paper a special type of nonlinear marking specifications called stair generalized mutual exclusion constraints (stair-GMECs) is defined. A stair-GMEC can be represented by an inequality whose left-hand is a linear combination of floor functions. Stair-GMECs have higher modeling power than classical GMECs and can model legal marking sets that cannot be defined by OR–AND GMECs. We propose two algorithms to enforce a stair-GMEC as a closed-loop net, in which the control structure is composed by a residue counter, remainder counters, and duplicate transitions. We also show that the proposed control structure is maximally permissive since it prevents all and only the illegal trajectories of a plant net. This approach can be applied to both bounded and unbounded nets. Several examples are proposed to illustrate the approach
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