1,728,855 research outputs found
Hadamard Z₂Z₄Q₈-codes : rank and kernel
No full textPublicació amb motiu del 4th International Castle Meeting (Palmela Castle, Portugal, 2014)Hadamard Z₂Z₄Q₈-codes are Hadamard binary codes coming from a subgroup of the direct product of Z₂, Z₄ and Q ₈ groups, where Q ₈ is the quaternionic group. We characterize Hadamard Z₂Z₄Q₈-codes as a quotient of a semidirect product of Z₂Z₄-linear codes and we show that all these codes can be represented in a standard form, from a set of generators. On the other hand, we show that there exist Hadamard Z₂Z₄Q₈-codes with any given pair of allowable parameters for the rank and dimension of the kernel
Magnetic phase diagram and reentrant superconductivity in DyNi2B2C single crystals
No full textIn order to investigate the interaction between superconductivity and magnetic ordering resistivity, magnetisation measurements were performed on DyNi2B2C single crystals for T = 0.05-15 K and for B = 0-5 T in the crystallographic ab-plane. Measurements of the magnetisation with a torque cantilever magnetometer give strong evidence for metamagnetic states built of different ordered ferromagnetic domains. For B parallel to [100]. an anomalous large hysteresis effect of the metamagnetic transitions and also of the superconducting transitions were observed in the low-temperature range (T < 2 K). In some extreme cases, the metamagnetic state can be frozen after a field cycle sweeping up to 2 T and down to zero at 50 mK. In this case, superconductivity is totally suppressed. The superconducting state can be restored in two ways: Either with increasing temperature, or by applying a small field with the opposite field direction. (C) 2001 Elsevier Science B.V. All rights reserved
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
Phylum Nematoda*
No full textHodda, Mike, Z.-Q (2007): Phylum Nematoda*. Zootaxa 1668 (1): 265-293, DOI: 10.11646/zootaxa.1668.1.14, URL: https://www.biotaxa.org/Zootaxa/article/view/zootaxa.1668.1.1
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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