1,721,000 research outputs found
A reconstruction algorithm for a subclass of instances of the 2-color problem
No full textIn the field of Discrete Tomography, the 2-color problem consists in reconstructing a matrix whose elements are of two different types, starting from its horizontal and vertical projections. It is known that the 1-color problem admits a polynomial time reconstruction algorithm, while the c-color problem, with c ≥ 2, is NP-hard. Thus, the 2-color problem constitutes an interesting example of a problem just in the frontier between hard and easy problems.
In this paper we define a linear time algorithm (in the size of the output matrix) to solve a subclass of its instances, where some values of the horizontal and vertical projections are constant, while the others are upper bounded by a positive number proportional to the dimension of the problem. Our algorithm relies on classical studies for the solution of the 1-color problem
On the Exhaustive Generation of k-Convex Polyominoes
No full textIn this paper we present a simple algorithm for computing the degree of convexity of a convex polyomino, defined as the smallest integer k such that any two cells of P can be joined by a monotone path inside P with at most k changes of direction. We show how it can be used to obtain an efficient algorithm for computing all k-convex polyominoes of size n. More precisely, such an algorithm uses space O(n) and runs in constant amortized time
Esperienze di verifica di funzionalità di impianti di trattamento anaerobico di reflui suinicoli: risultati di una sperimentazione su quattro impianti nella provincia di Brescia
No full textA tiling system for L-convex polyominoes
No full textA polyomino is said to be L-convex if any two of its cells can be connected by a path entirely contained in the polyomino, and having at most one change of direction. In this paper, answering a problem posed by Castiglione and Vaglica [6], we prove that the class of L-convex polyominoes is tiling recognizable. To reach this goal, first we express the L-convexity constraint in terms of a set of independent properties, then we show that each class of convex polyominoes having one of these properties is tiling recognizable
A Campylobacter jejuni enteritis that baffles
No full textCampylobacter infection is one of the most frequent enteritis in developed countries and in most cases it features a self-limiting character. In some cases it shows severe clinical pictures and it requires antibiotic therapy. Cases of antibiotic resistance are emerging, especially against fluoroquinolone. The article presents a case of a 14-year-old boy with a febrile Campylobacter enteritis treated with ceftriaxone and cipro-floxacin with an immediate resolution of the symptoms. Ten days later, the boy still showed the same symptoms suggesting three hypotheses: 1) failure of Campylobacter's eradication; 2) abdominal abscess; 3) beginning of inflammatory bowel disease associated with a concomitant and confusing Campylobacter jejuni infection. Coproculture still showed the presence of Campylobacter, and the treatment with azithromycin was effective in eradicating the infection. Past history and complete negativity of inflammatory index and faecal calprotectin allowed an inflammatory bowel disease to be excluded
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
- …
