1,720,966 research outputs found
Hamiltonian paths in the complete graph with edge-lengths 1, 2, 3
No full textMarco Buratti has conjectured that, given an odd prime p and a multiset L containing p - 1 integers taken from {1,..., p-1/2}, there exists a Hamiltonian path in the complete graph with p vertices whose multiset of edge-lengths is equal to L modulo p. We give a positive answer to this conjecture in the case of multisets of the type {1(a),2(b),3(c)} by completely classifying such multisets that are linearly or cyclically realizable
Dyck paths, Motzkin paths, and the binomial transform
Get PDFWe study the moments of orthogonal polynomial sequences (OPS) arising from
tridiagonal matrices. We obtain combinatorial information about the sequence of moments
of some OPS in terms of Motzkin and Dyck paths, and also in terms of the
binomial transform. We then introduce an equivalence relation on the set of Dyck
paths and some operations on them. We determine a formula for the cardinality of
those equivalence classes, and use this information to obtain a combinatorial formula
for the number of Dyck and Motzkin paths of a fixed length
Geometria
No full textManuale per il corso di Geometria per studenti di Ingegneria. Contiene nozioni di base di Geometria Analitica ed Algebra Lineare. Sono inclusi anche alcuni argomenti per un secondo corso di Algebra Lineare
Geometria
No full textIl presente volume è strutturato in modo da essere utilizzabile in corsi di Geometria da 6 a 12 crediti per studenti di corsi triennali di Ingegneria. Una parte del testo fornisce le basi per la conoscenza dell’Algebra Lineare (vettori numerici, matrici, sistemi lineari) e della Geometria Analitica (punti, rette, piani, coniche e quadriche in equazione canonica). Successivamente vengono approfonditi argomenti relativi alle coniche, introdotti elementi di Geometria Differenziale delle curve nello spazio e ripreso lo studio dell’Algebra Lineare in un ambito più generale (spazi vettoriali e euclidei, applicazioni lineari, diagonalizzazione).This volume is organized so as to be used in first year 6 or 12 credit geometry courses for engineering students. Part of the book gives the fundamentals of linear algebra (vectors, matrices, linear systems) and analytic geometry (lines, planes conics and quadrics) There are also elements of differential geometry of curves and some extra topics in linear algebra such as general euclidean spaces and the principal axes theorem
Cyclic Hamiltonian cycle systems of the lambda-fold complete and cocktail party graphs
No full textWe establish the necessary and sufficient conditions for the existence of a cyclic Hamiltonian cycle system of lambda K(v) and of lambda(K(2v) - I). We also consider the existence problem for cyclic Hamiltonian cycle systems of lambda K(v) that are simple, i.e., without repeated cycles, solving it in the case that v is a prime. (C) 2010 Elsevier Ltd. All rights reserved
On the span of polynomials with integer coefficients
No full textFollowing a paper of R. Robinson, we classify all hyperbolic polynomials in one variable with integer coefficients and span less than 4 up to degree 14, and with some additional hypotheses, up to degree 17. We conjecture that the classification is also complete for degrees 15, 16, and 17. Besides improving on the method used by Robinson, we develop new techniques that turn out to be of some interest. A close inspection of the polynomials thus obtained shows some properties deserving further investigations
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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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