1,721,001 research outputs found
Linewidth for fluxons oscillators
No full textSoliton perturbation theory is used to calculate the fluxon oscillator linewidth arising from fluxon interaction with background radiation. Detailed calculations in the case of an oscillator that is long compared with the Josephson length and for which the radiation field is thermal establish lower bounds for the linewidth of a real oscillator. These lower bounds are not in disagreement with recent, instrument-limited measurements of X-band linewidths less than 5 kHz
QUANTUM THEORIES FOR 2 DISCRETE NONLINEAR SCHRODINGER-EQUATIONS
No full texthere are two simple discrete versions of the nonlinear Schrodinger equation: (i) the discrete self-trapping system which preserves the standard norm, and (ii) the Ablowitz-Ladik system which is integrable using the inverse scattering method. In this paper the quantum theories for the two systems are sketched and compared.
Document Type: Articl
ALTERNATE QUANTIZATIONS OF THE DISCRETE SELF-TRAPPING DIMER
No full textIn this paper we study the classical and quantum two freedoms Discrete Self-Trapping system by the Inverse Scattering Method. We develop the algebraic approach in terms of the classical r-matrix and quantum R-matrix and give an interpretation of the commutation relations in terms of Sklyanin's quadratic algebra. The quantization is then developed in detail and the first energy levels are obtained. The results are compared with those obtained from the quantization scheme of Scott and Eilbeck
THERES MORE THAN ONE WAY TO SKIN SCHRODINGER CAT
No full textTwo methods for studying quantum discrete dynamical systes (i.e. with a finite or countably infinite number of degrees of freedom) are described and compared for: (i) The discrete self-trapping (DST) equation, (ii) The Ablowitz-Ladik (AL) equation, and (iii) A fermionic polaron (FP) model. The first method, called the quantum inverse scattering method (QISM), emphasizes the relationship between the quantum theory and classical integrability The second method, which we call the number state method (NSM), cam be extended to systems that are not classically integrable. Thus the two methods are not equivalent
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
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