1,721,037 research outputs found
First Gravity Wave Coincidence Experiment Between Three Cryogenic Resonant-Mass Detectors: Lousiana-Rome-Stanford
No full textDocufilm "La Scelta. Edoardo Amaldi e la scienza senza confini"
No full textPremio 2020 della Società italiana di fisica per la Comunicazione Scientifica per la sceneggiatura del documentario “La Scelta. Edoardo Amaldi e la Scienza senza confini”, lavoro esemplare di comunicazione scientifica che scaturisce anche da un’approfondita attività di ricerca storica e d’archivio e da una preziosa raccolta di testimonianze orali
Efficient Deterministic Algorithms for Finding a Minimum Cycle Basis in Undirected Graphs.
No full textWe consider the problem of, given an undirected graph G with a nonnegative weight on each edge, finding a basis of the cycle space of G of minimum total weight, where the total weight of a basis is the sum of the weights of its cycles. Minimum cycle bases are of interest in a variety of fields. In [13] Horton proposed a first polynomial-time algorithm where a minimum cycle basis is extracted from a polynomial-size subset of candidate cycles in O(m^3 n) by using Gaussian elimination. In a different approach, due to de Pina [7] and refined in [15], the cycles of a minimum cycle basis are determined sequentially in O(m^2 n + m n^2 logn). A more sophisticated hybrid algorithm proposed in [18] has the best worst-case complexity of O(m^2 n / log n + m n^2).
In this work we revisit Horton’s and de Pina’s approaches and we propose a simple hybrid algorithm which improves the worst-case complexity to O(m^2 n / logn). We also present a very efficient related algorithm that relies on an adaptive independence test à la de Pina. Computational results on a wide set of instances show that the latter algorithm outperforms the previous algorithms by one or two order of magnitude on medium-size instances and allows to solve instances with up to 3000 vertices in a reasonable time
Robust optimization for the scheduling of isolated RES-based microgrids in developing countries
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A local search method for costly black-box problems and its application to CSP plant start-up optimization refinement
No full textA variety of engineering applications are tackled as black-box optimization problems where a computationally expensive and possibly noisy function is optimized over a continuous domain. In this paper we present a derivative-free local method which is well-suited for such problems, and we describe its application to the optimization of the start-up phase of an innovative Concentrated Solar Power (CSP) plant. The method, referred to as rqlif, exploits a regularized quadratic model and a linear implicit filtering strategy so as to be parsimonious in terms of function evaluations. After assessing the performance of rqlif on a set of analytical test problems in comparison with three well-known local algorithms, we apply it in conjunction with a global algorithm based on RBFs interpolation to the start-up optimization of the CSP plant developed in the PreFlexMS H2020 project. For the test problems, rqlif provides good quality solutions in a limited number of function evaluations. For the application, the global–local strategy yields a substantial improvement with respect to the reference solution and significantly reduces the thermo-mechanical stress suffered by the plant components
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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