Academic literature on the topic 'Graphe simple'
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Journal articles on the topic "Graphe simple"
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Hudry, Olivier. "Application of the “descent with mutations” metaheuristic to a clique partitioning problem." RAIRO - Operations Research 53, no. 3 (2019): 1083–95. http://dx.doi.org/10.1051/ro/2018048.
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We study here the application of the “descent with mutations” metaheuristic to a problem arising from the field of classification and cluster analysis (dealing more precisely with the aggregation of symmetric relations) and which can be represented as a clique partitioning of a weighted graph. In this problem, we deai with a complete undirected graphe G; the edges of G have weights which can be positive, negative or equal to 0; the aim is to partition the vertices of G into disjoint cliques (whose number depends on G in order to minimize the sum of the weights of the edges with their two extremities in a same clique; this problem is NP-hard. The “descent with mutations” is a local search metaheuristic, of which the design is very simple and is based on local transformation. It consists in randomly performing random elementary transformations, irrespective improvement or worsening with respect to the objective function. We compare it with another very efficient metaheuristic, which is a simulated annealing method improved by the addition of some ingredients coming from the noising methods. Experiments show that the descent with mutations is at least as efficient for the studied problem as this improved simulated annealing, usually a little better, while it is much easier to design and to tune.
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Malik, M. Aslam, and M. Khalid Mahmood. "On Simple Graphs Arising from Exponential Congruences." Journal of Applied Mathematics 2012 (2012): 1–10. http://dx.doi.org/10.1155/2012/292895.
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We introduce and investigate a new class of graphs arrived from exponential congruences. For each pair of positive integersaandb, letG(n)denote the graph for whichV={0,1,…,n−1}is the set of vertices and there is an edge betweenaandbif the congruenceax≡b (mod n)is solvable. Letn=p1k1p2k2⋯prkrbe the prime power factorization of an integern, wherep1<p2<⋯<prare distinct primes. The number of nontrivial self-loops of the graphG(n)has been determined and shown to be equal to∏i=1r(ϕ(piki)+1). It is shown that the graphG(n)has2rcomponents. Further, it is proved that the componentΓpof the simple graphG(p2)is a tree with root at zero, and ifnis a Fermat's prime, then the componentΓϕ(n)of the simple graphG(n)is complete.
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Voorhees, Burton, and Alex Murray. "Fixation probabilities for simple digraphs." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 469, no. 2154 (2013): 20120676. http://dx.doi.org/10.1098/rspa.2012.0676.
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The problem of finding birth–death fixation probabilities for configurations of normal and mutants on an N -vertex graph is formulated in terms of a Markov process on the 2 N -dimensional state space of possible configurations. Upper and lower bounds on the fixation probability after any given number of iterations of the birth–death process are derived in terms of the transition matrix of this process. Consideration is then specialized to a family of graphs called circular flows, and we present a summation formula for the complete bipartite graph, giving the fixation probability for an arbitrary configuration of mutants in terms of a weighted sum of the single-vertex fixation probabilities. This also yields a closed-form solution for the fixation probability of bipartite graphs. Three entropy measures are introduced, providing information about graph structure. Finally, a number of examples are presented, illustrating cases of graphs that enhance or suppress fixation probability for fitness r >1 as well as graphs that enhance fixation probability for only a limited range of fitness. Results are compared with recent results reported in the literature, where a positive correlation is observed between vertex degree variance and fixation probability for undirected graphs. We show a similar correlation for directed graphs, with correlation not directly to fixation probability but to the difference between fixation probability for a given graph and a complete graph.
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Azari, M., and A. Iranmanesh. "On the edge-Wiener index of the disjunctive product of simple graphs." Algebra and Discrete Mathematics 30, no. 1 (2020): 1–14. http://dx.doi.org/10.12958/adm242.
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The edge-Wiener index of a simple connected graph G is defined as the sum of distances between all pairs of edges of G where the distance between two edges in G is the distance between the corresponding vertices in the line graph of G. In this paper, we study the edge-Wiener index under the disjunctive product of graphs and apply our results to compute the edge-Wiener index for the disjunctive product of paths and cycles.
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Ali, Akbar. "Tetracyclic graphs with maximum second Zagreb index: A simple approach." Asian-European Journal of Mathematics 11, no. 05 (2018): 1850064. http://dx.doi.org/10.1142/s179355711850064x.
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In the chemical graph theory, graph invariants are usually referred to as topological indices. The second Zagreb index (denoted by [Formula: see text]) is one of the most studied topological indices. For [Formula: see text], let [Formula: see text] be the collection of all non-isomorphic connected graphs with [Formula: see text] vertices and [Formula: see text] edges (such graphs are known as tetracyclic graphs). Recently, Habibi et al. [Extremal tetracyclic graphs with respect to the first and second Zagreb indices, Trans. on Combin. 5(4) (2016) 35–55.] characterized the graph having maximum [Formula: see text] value among all members of the collection [Formula: see text]. In this short note, an alternative but relatively simple approach is used for characterizing the aforementioned graph.
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Vasanthi, R., and K. Subramanian. "On Vertex Covering Transversal Domination Number of Regular Graphs." Scientific World Journal 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/1029024.
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A simple graphG=(V,E)is said to ber-regular if each vertex ofGis of degreer. The vertex covering transversal domination numberγvct(G)is the minimum cardinality among all vertex covering transversal dominating sets ofG. In this paper, we analyse this parameter on different kinds of regular graphs especially forQnandH3,n. Also we provide an upper bound forγvctof a connected cubic graph of ordern≥8. Then we try to provide a more stronger relationship betweenγandγvct.
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Voorhees, Burton, and Bergerud Ryder. "Simple graph models of information spread in finite populations." Royal Society Open Science 2, no. 5 (2015): 150028. http://dx.doi.org/10.1098/rsos.150028.
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We consider several classes of simple graphs as potential models for information diffusion in a structured population. These include biases cycles, dual circular flows, partial bipartite graphs and what we call ‘single-link’ graphs. In addition to fixation probabilities, we study structure parameters for these graphs, including eigenvalues of the Laplacian, conductances, communicability and expected hitting times. In several cases, values of these parameters are related, most strongly so for partial bipartite graphs. A measure of directional bias in cycles and circular flows arises from the non-zero eigenvalues of the antisymmetric part of the Laplacian and another measure is found for cycles as the value of the transition probability for which hitting times going in either direction of the cycle are equal. A generalization of circular flow graphs is used to illustrate the possibility of tuning edge weights to match pre-specified values for graph parameters; in particular, we show that generalizations of circular flows can be tuned to have fixation probabilities equal to the Moran probability for a complete graph by tuning vertex temperature profiles. Finally, single-link graphs are introduced as an example of a graph involving a bottleneck in the connection between two components and these are compared to the partial bipartite graphs.
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TROTTA, BELINDA. "RESIDUAL PROPERTIES OF SIMPLE GRAPHS." Bulletin of the Australian Mathematical Society 82, no. 3 (2010): 488–504. http://dx.doi.org/10.1017/s0004972710000420.
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AbstractClark et al. [‘The axiomatizability of topological prevarieties’, Adv. Math.218 (2008), 1604–1653] have shown that, for k≥2, there exists a Boolean topological graph that is k-colourable but not topologically k-colourable; that is, for every ϵ>0, it cannot be coloured by a paintbrush of width ϵ. We generalize this result to show that, for k≥2, there is a Boolean topological graph that is 2-colourable but not topologically k-colourable. This graph is an inverse limit of finite graphs which are shown to exist by an Erdős-style probabilistic argument of Hell and Nešetřil [‘The core of a graph’, Discrete Math.109 (1992), 117–126]. We use the fact that there exists a Boolean topological graph that is 2-colourable but not k-colourable, and some other results (some new and some previously known), to answer the question of which finitely generated topological residual classes of graphs are axiomatizable by universal Horn sentences. A more general version of this question was raised in the above-mentioned paper by Clark et al., and has been investigated by various authors for other structures.
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Devriendt, Karel, and Piet Van Mieghem. "The simplex geometry of graphs." Journal of Complex Networks 7, no. 4 (2019): 469–90. http://dx.doi.org/10.1093/comnet/cny036.
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AbstractGraphs are a central object of study in various scientific fields, such as discrete mathematics, theoretical computer science and network science. These graphs are typically studied using combinatorial, algebraic or probabilistic methods, each of which highlights the properties of graphs in a unique way. Here, we discuss a novel approach to study graphs: the simplex geometry (a simplex is a generalized triangle). This perspective, proposed by Miroslav Fiedler, introduces techniques from (simplex) geometry into the field of graph theory and conversely, via an exact correspondence. We introduce this graph-simplex correspondence, identify a number of basic connections between graph characteristics and simplex properties, and suggest some applications as example.
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BAHR, PATRICK. "Convergence in infinitary term graph rewriting systems is simple." Mathematical Structures in Computer Science 28, no. 8 (2018): 1363–414. http://dx.doi.org/10.1017/s0960129518000166.
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Term graph rewriting provides a formalism for implementing term rewriting in an efficient manner by emulating duplication via sharing. Infinitary term rewriting has been introduced to study infinite term reduction sequences. Such infinite reductions can be used to model non-strict evaluation. In this paper, we unify term graph rewriting and infinitary term rewriting thereby addressing both components of lazy evaluation: non-strictness and sharing. In contrast to previous attempts to formalise infinitary term graph rewriting, our approach is based on a simple and natural generalisation of the modes of convergence of infinitary term rewriting. We show that this new approach is better suited for infinitary term graph rewriting as it is simpler and more general. The latter is demonstrated by the fact that our notions of convergence give rise to two independent canonical and exhaustive constructions of infinite term graphs from finite term graphs via metric and ideal completion. In addition, we show that our notions of convergence on term graphs are sound w.r.t. the ones employed in infinitary term rewriting in the sense that convergence is preserved by unravelling term graphs to terms. Moreover, the resulting infinitary term graph calculi provide a unified framework for both infinitary term rewriting and term graph rewriting, which makes it possible to study the correspondences between these two worlds more closely.
Dissertations / Theses on the topic "Graphe simple"
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Islam, Md Kamrul. "Explainable link prediction in large complex graphs - application to drug repurposing." Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0203.
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De nombreux systèmes complexes du monde réel peuvent être représentés par des graphes, où les nœuds représentent des entités et les liens des relations entre les paires de nœuds. La prédiction de liens (LP) est l'un des problèmes les plus intéressants et les plus anciens dans le domaine de l'exploration de graphes ; elle prédit la probabilité d'un lien entre deux nœuds non connectés. Cette thèse étudie le problème LP dans les graphes simples et les graphes de connaissances (KGs). La première partie de cette thèse se concentre sur le problème LP dans les graphes simples. Dans la première étude, des approches basées sur la similarité et sur l'encastrement sont évaluées et comparées sur des graphes simples de différents domaines. L'étude a également identifié la difficulté de fixer le seuil du score de similarité pour calculer la métrique de précision des approches basées sur la similarité et a proposé une nouvelle méthode pour calculer la métrique. Les résultats ont montré la supériorité attendue des approches basées sur l'intégration. Cependant, chaque approche basée sur la similarité s'est avérée compétitive sur des graphes aux propriétés spécifiques. Nous avons pu vérifier expérimentalement que les approches basées sur la similarité sont explicables mais manquent de généralisation, tandis que les approches basées sur l'encastrement sont générales mais non explicables. La deuxième étude tente de surmonter la limitation de l'inexplicabilité des approches basées sur l'encastrement en découvrant des connexions intéressantes entre elles et les approches basées sur la similarité. La troisième étude démontre comment les approches basées sur la similarité peuvent être assemblées pour concevoir une approche LP supervisée explicable. Il est intéressant de noter que l'étude montre des performances LP élevées pour l'approche supervisée sur différents graphes, ce qui est très satisfaisant. La deuxième partie de la thèse se concentre sur les LP dans les KGs. Un KG est représenté comme une collection de triplets RDF, (head,relation,tail) où les entités head et tail sont reliées par une relation spécifique. Le problème de LP dans un KG est formulé comme la prédiction de la tête ou de la queue manquante dans un triplet. La LP basée sur l'incorporation de KG est devenue très populaire ces dernières années, et la génération de triplets négatifs est une tâche importante dans les méthodes d'incorporation. La quatrième étude traite d'une nouvelle méthode appelée SNS pour générer des triplets négatifs de haute qualité. Nos résultats montrent une meilleure performance LP lorsque SNS est utilisé que lorsque d'autres méthodes d'échantillonnage négatif sont utilisées. La deuxième étude traite d'une nouvelle méthode d'extraction de règles neuro-symboliques et d'une stratégie d'abduction pour expliquer les LP par une approche basée sur l'intégration en utilisant les règles apprises. La troisième étude applique notre LP explicable pour développer une nouvelle approche de repositionnement des médicaments pour COVID-19. L'approche apprend un ensemble d'enchâssements d'entités et de relations dans un KG centré sur COVID-19 pour obtenir un meilleur enchâssement des éléments du graphe. Pour la première fois à notre connaissance, des méthodes de criblage virtuel sont ensuite utilisées pour évaluer les prédictions obtenues à l'aide des embeddings. L'évaluation moléculaire et les chemins explicatifs apportent de la fiabilité aux résultats de prédiction et sont de nouvelles méthodes complémentaires et réutilisables pour mieux évaluer les molécules proposées pour le repositionnement. La dernière étude propose une architecture distribuée pour l'apprentissage des KG embeddings dans des environnements distribués et parallèles. Les résultats révèlent que l'apprentissage dans l'environnement distribué proposé, par rapport à un apprentissage centralisé, réduit considérablement le temps de calcul des méthodes d'incorporation KG sans affecter les performances des LP<br>Many real-world complex systems can be well-represented with graphs, where nodes represent objects or entities and links/relations represent interactions between pairs of nodes. Link prediction (LP) is one of the most interesting and long-standing problems in the field of graph mining; it predicts the probability of a link between two unconnected nodes based on available information in the current graph. This thesis studies the LP problem in graphs. It consists of two parts: LP in simple graphs and LP knowledge graphs (KGs). In the first part, the LP problem is defined as predicting the probability of a link between a pair of nodes in a simple graph. In the first study, a few similarity-based and embedding-based LP approaches are evaluated and compared on simple graphs from various domains. he study also criticizes the traditional way of computing the precision metric of similarity-based approaches as the computation faces the difficulty of tuning the threshold for deciding the link existence based on the similarity score. We proposed a new way of computing the precision metric. The results showed the expected superiority of embedding-based approaches. Still, each of the similarity-based approaches is competitive on graphs with specific properties. We could check experimentally that similarity-based approaches are fully explainable but lack generalization due to their heuristic nature, whereas embedding-based approaches are general but not explainable. The second study tries to alleviate the unexplainability limitation of embedding-based approaches by uncovering interesting connections between them and similarity-based approaches to get an idea of what is learned in embedding-based approaches. The third study demonstrates how the similarity-based approaches can be ensembled to design an explainable supervised LP approach. Interestingly, the study shows high LP performance for the supervised approach across various graphs, which is competitive with embedding-based approaches.The second part of the thesis focuses on LP in KGs. A KG is represented as a collection of RDF triples, (head,relation,tail) where the head and the tail are two entities which are connected by a specific relation. The LP problem in a KG is formulated as predicting missing head or tail entities in a triple. LP approaches based on the embeddings of entities and relations of a KG have become very popular in recent years, and generating negative triples is an important task in KG embedding methods. The first study in this part discusses a new method called SNS to generate high-quality negative triples during the training of embedding methods for learning embeddings of KGs. The results we produced show better LP performance when SNS is injected into an embedding approach than when injecting state-of-the-art negative triple sampling methods. The second study in the second part discusses a new neuro-symbolic method of mining rules and an abduction strategy to explain LP by an embedding-based approach utilizing the learned rules. The third study applies the explainable LP to a COVID-19 KG to develop a new drug repurposing approach for COVID-19. The approach learns ”ensemble embeddings” of entities and relations in a COVID-19 centric KG, in order to get a better latent representation of the graph elements. For the first time to our knowledge, molecular docking is then used to evaluate the predictions obtained from drug repurposing using KG embedding. Molecular evaluation and explanatory paths bring reliability to prediction results and constitute new complementary and reusable methods for assessing KG-based drug repurposing. The last study proposes a distributed architecture for learning KG embeddings in distributed and parallel settings. The results of the study that the computational time of embedding methods improves remarkably without affecting LP performance when they are trained in the proposed distributed settings than the traditional centralized settings
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Lehbab, Imène. "Problèmes métriques dans les espaces de Grassmann." Electronic Thesis or Diss., Mulhouse, 2023. http://www.theses.fr/2023MULH6508.
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Il s'agit d'une contribution dans le domaine de la géométrie métrique du plan projectif complexe CP2 et de la variété de Grassmann réelle des plans dans R6. On s'intéresse à l'étude de tous les p-uplets, p ≥ 3, de droites équiangulaires dans C3 et des p-uplets de plans équi-isoclins dans R6. Sachant que 9 est le nombre maximum de droites équiangulaires que l'on peut construire dans C3, on décrit une méthode qui permet de construire tous les p-uplets de droites équiangulaires pour tout pϵ[3,9]. En particulier, on construit dans C3 cinq classes de congruence de quadruplets de droites équiangulaires dont une dépend d'un paramètre réel ɣ que l'on étend à une famille infinie de sextuplets de droites équiangulaires dépendant du même paramètre réel ɣ. En outre, on donne les angles pour lesquels nos sextuplets s'étendent au-delà et jusqu'aux 9-uplets. On sait qu'il existe un p-uplet, p≥3, de plans équi-isoclins engendrant Rr, r≥4, de paramètre c, 0<br>This work contributes to the field of metric geometry of the complex projective plane CP2 and the real Grassmannian manifold of the planes in R6. More specifically, we study all p-tuples, p ≥ 3, of equiangular lines in C3 or equidistant points in CP2, and p-tuples of equi-isoclinic planes in R6. Knowing that 9 is the maximum number of equiangular lines that can be constructed in C3, we develop a method to obtain all p-tuples of equiangular lines for all p ϵ [3,9]. In particular, we construct in C3 five congruence classes of quadruples of equiangular lines, one of which depends on a real parameter ɣ, which we extend to an infinite family of sextuples of equiangular lines depending on the same real parameter ɣ. In addition, we give the angles for which our sextuples extend beyond and up to 9-tuples. We know that there exists a p-tuple, p ≥ 3, of equi-isoclinic planes generating Rr, r ≥ 4, with parameter c, 0< c <1, if and only if there exists a square symmetric matrix, called Seidel matrix, of p × p square blocks of order 2, whose diagonal blocks are all zero and the others are orthogonal matrices in O(2) and whose smallest eigenvalue is equal to - 1/c and has multiplicity 2p-r. In this thesis, we investigate the case r=6 and we also show that we can explicitly determine the spectrum of all Seidel matrices of order 2p, p ≥ 3 whose off-diagonal blocks are in {R0, S0} where R0 and S0 are respectively the zero-angle rotation and the zero-angle symmetry. We thus show an unexpected link between some p-tuples of equi-isoclinic planes in Rr and simple graphs of order p
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Montanaro, William M. Jr. "Character Degree Graphs of Almost Simple Groups." Kent State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=kent1398345504.
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CRUCIANI, EMILIO. "Simple Randomized Distributed Algorithms for Graph Clustering." Doctoral thesis, Gran Sasso Science Institute, 2019. http://hdl.handle.net/20.500.12571/9951.
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Label Propagation Algorithms are a class of heuristics for the problem of graph clustering, i.e., the problem of detecting groups of nodes whose connections are dense within each group and sparse between the groups. At the onset, a label is assigned to each node of the graph; then, each node iteratively updates its label according to a function of the labels of its neighbors. Empirical studies show that, after only a few rounds, nodes in the same cluster share the same label while nodes in different clusters have different labels. Although they are widely used in practice given their simplicity, efficiency, and effectiveness, there is no theoretical foundation to explain why such simple algorithms are able to perform such a hard task. The absence of theoretical progress in the analysis of Label Propagation Algorithms is due to the lack of mathematical techniques for handling the interplay between the non-linearity of their update rule and the topology of the underlying graph.
In this thesis we contextualize Label Propagation Algorithms in the framework of computational dynamics, simple dynamical processes on networks whose behavior has been formally characterized on some classes of graphs. The analyses of computational dynamics were mainly focused on graphs with good connectivity properties, such as cliques or expanders, and on the problem of consensus, showing that they naturally converge to a configuration in which all the nodes agree on some value. We move a step forward in this direction by rigorously analyzing two simple dynamics, the 2-Choices dynamics and the Averaging dynamics, reaching a more fine-grained comprehension of their consensus behavior in classes of graphs that exhibit a clustered structure. In particular we formally prove that, with non-negligible probability, the two dynamics quickly bring the graph in a configuration where each cluster reaches an internal consensus on a value that is different among the clusters, and then enters a long metastable phase in which the internal consensus are maintained.
We show how to exploit such metastable behavior to design simple randomized distributed algorithms for graph clustering.
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Yan, Chenyu. "APPROXIMATING DISTANCES IN COMPLICATED GRAPHS BY DISTANCES IN SIMPLE GRAPHS WITH APPLICATIONS." Kent State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=kent1184639623.
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Kimmel, Jason. "Simple Games on Networks." Oberlin College Honors Theses / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=oberlin1307994412.
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Okeke, Nnamdi, and University of Lethbridge Faculty of Arts and Science. "Character generators and graphs for simple lie algebras." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2006, 2006. http://hdl.handle.net/10133/532.
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We study character generating functions (character generators) of simple Lie algebras. The
expression due to Patera and Sharp, derived from the Weyl character formula, is ¯rst re-
viewed. A new general formula is then found. It makes clear the distinct roles of \outside"
and \inside" elements of the integrity basis, and helps determine their quadratic incompati-
bilities. We review, analyze and extend the results obtained by Gaskell using the Demazure
character formulas. We ¯nd that the fundamental generalized-poset graphs underlying the
character generators can be deduced from such calculations. These graphs, introduced by
Baclawski and Towber, can be simpli¯ed for the purposes of constructing the character
generator. The generating functions can be written easily using the simpli¯ed versions,
and associated Demazure expressions. The rank-two algebras are treated in detail, but we
believe our results are indicative of those for general simple Lie algebras.<br>vii, 92 leaves ; 29 cm.
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Everett, Alistaire Duncan Fraser. "Commuting involution graphs of certain finite simple classical groups." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/commuting-involution-graphs-of-certain-finite-simple-classical-groups(dd54ee3d-8c94-42cd-87e1-d34770756466).html.
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For a group G and X a subset of G, the commuting graph of G on X, denoted by C(G,X), is the graph whose vertex set is X with x, y joined by an edge if x not equal to y and x and y commute. If the elements in X are involutions, then C(G,X) is called a commuting involution graph. This thesis studies C(G,X) when G is either a 4-dimensional projective symplectic group; a 3-dimensional unitary group; 4-dimensional unitary group over a field of characteristic 2; a 2-dimensional projective general linear group; or a 4-dimensional affne orthogonal group, and X a G-conjugacy class of involutions. We determine the diameters and structure of thediscs of these graphs.
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Bosi, Gianluca <1991>. "Simple random walks on some partially directed planar graphs." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amsdottorato.unibo.it/8914/1/bosi_gianluca_tesi.pdf.
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In this thesis we analyze the recurrence behavior of simple random walks on some classes of directed planar graphs. Our first model is a version of the honeycomb lattice, where the horizontal edges are randomly oriented according to families of random variables: depending on their distribution, we prove a.s. transience in some cases, and a.s. recurrence in other ones. Our results extend those obtained by Campanino and Petritis (’03 and ’14) for partially oriented square grid lattices.
Furthermore, we consider two directed square grid lattices on which, because of the direction imposed by the oriented edges, the simple random walk is bound to revolve clockwise: we prove recurrence for one of the graphs, solving a conjecture of Menshikov et al. (’17), and we give a new proof of transience for the other one.
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Mahfoudh, Mariem. "Adaptation d'ontologies avec les grammaires de graphes typés : évolution et fusion." Thesis, Mulhouse, 2015. http://www.theses.fr/2015MULH1519/document.
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Étant une représentation formelle et explicite des connaissances d'un domaine, les ontologies font régulièrement l'objet de nombreux changements et ont ainsi besoin d'être constamment adaptées pour notamment pouvoir être réutilisées et répondre aux nouveaux besoins. Leur réutilisation peut prendre différentes formes (évolution, alignement, fusion, etc.), et présente plusieurs verrous scientifiques. L'un des plus importants est la préservation de la consistance de l'ontologie lors de son changement. Afin d'y répondre, nous nous intéressons dans cette thèse à étudier les changements ontologiques et proposons un cadre formel capable de faire évoluer et de fusionner des ontologies sans affecter leur consistance. Premièrement, nous proposons TGGOnto (Typed Graph Grammars for Ontologies), un nouveau formalisme permettant la représentation des ontologies et leurs changements par les grammaires de graphes typés. Un couplage entre ces deux formalismes est défini afin de profiter des concepts des grammaires de graphes, notamment les NAC (Negative Application Conditions), pour la préservation de la consistance de l'ontologie adaptée.Deuxièmement, nous proposons EvOGG (Evolving Ontologies with Graph Grammars), une approche d'évolution d'ontologies qui se base sur le formalisme GGTOnto et traite les inconsistances d'une manière a priori. Nous nous intéressons aux ontologies OWL et nous traitons à la fois : (1) l'enrichissement d'ontologies en étudiant leur niveau structurel et (2) le peuplement d'ontologies en étudiant les changements qui affectent les individus et leurs assertions. L'approche EvOGG définit des changements ontologiques de différents types (élémentaires, composées et complexes) et assure leur implémentation par l'approche algébrique de transformation de graphes, SPO (Simple PushOut). Troisièmement, nous proposons GROM (Graph Rewriting for Ontology Merging), une approche de fusion d'ontologies capable d'éviter les redondances de données et de diminuer les conflits dans le résultat de fusion. L'approche proposée se décompose en trois étapes : (1) la recherche de similarité entre concepts en se basant sur des techniques syntaxiques, structurelles et sémantiques ; (2) la fusion d'ontologies par l'approche algébrique SPO ; (3) l'adaptation de l'ontologie globale résultante par le biais des règles de réécriture de graphes.Afin de valider les travaux menés dans cette thèse, nous avons développé plusieurs outils open source basés sur l'outil AGG (Attributed Graph Grammar). Ces outils ont été appliqués sur un ensemble d'ontologies, essentiellement sur celles développées dans le cadre du projet européen CCAlps (Creatives Companies in Alpine Space) qui a financé les travaux de cette thèse<br>Ontologies are a formal and explicit knowledge representation. They represent a given domain by their concepts and axioms while creating a consensus between a user community. To satisfy the new requirements of the represented domain, ontologies have to be regularly updated and adapted to maintain their consistency. The adaptation may take different forms (evolution, alignment, merging, etc.), and represents several scientific challenges. One of the most important is to preserve the consistency of the ontology during the changes. To address this issue, we are interested in this thesis to study the ontology changes and we propose a formal framework that can evolve and merge ontologies without affecting their consistency.First we propose TGGOnto (Typed Graph Grammars for Ontologies), a new formalism for the representation of ontologies and their changes using typed graph grammars (TGG). A coupling between ontologies and TGG is defined in order to take advantage of the graph grammars concepts, such as the NAC (Negative Application Conditions), in preserving the adapted ontology consistency. Second, we propose EvOGG (Evolving Ontologies with Graph Grammars), an ontology evolution approach that is based on the TGGOnto formalism that avoids inconsistencies using an a priori approach. We focus on OWL ontologies and we address both : (1) ontology enrichment by studying their structural level and (2) ontology population by studying the changes affecting individuals and their assertions. EvOGG approach defines different types of ontology changes (elementary, composite and complex) and ensures their implementation by the algebraic approach of graph transformation, SPO (Single pushout).Third, we propose GROM (Graph Rewriting for Ontology Merging), an ontologies merging approach that avoids data redundancy and reduces conflict in the merged result. The proposed approach consists of three steps: (1) the similarity search between concepts based on syntactic, structural and semantic techniques; (2) the ontologies merging by the algebraic approach SPO; (3) the global ontology adaptation with graph rewriting rules.To validate our proposals, we have developed several open source tools based on AGG (Attributed Graph Grammar) tool. These tools were applied to a set of ontologies, mainly on those developed in the frame of the CCAlps (Creatives Companies in Alpine Space) European project, which funded this thesis work
Books on the topic "Graphe simple"
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Praeger, Cheryl E. Low rank representations and graphs for sporadic groups. Cambridge University Press, 1997.
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Praeger, Cheryl E. Low rank representations and graphs for sporadic groups. Cambridge University Press, 1996.
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Zörnig, Peter. Degeneracy Graphs and Simplex Cycling. Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-45702-9.
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Booth, Bob. Simple use of Cricket Graph for PC Windows. University of Sheffield, Academic Computing Services, 1992.
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Skrobol, Sebastian. Quiet little Melody: A simple fairytale. Prószyński Media, 2014.
Find full textBook chapters on the topic "Graphe simple"
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Aubert, J. P., J. F. Baget, and M. Chein. "Simple Conceptual Graphs and Simple Concept Graphs." In Conceptual Structures: Inspiration and Application. Springer Berlin Heidelberg, 2006. http://dx.doi.org/10.1007/11787181_7.
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Andersen, H. H., M. Højbjerre, D. Sørensen, and P. S. Eriksen. "Simple Undirected Graphs." In Linear and Graphical Models. Springer New York, 1995. http://dx.doi.org/10.1007/978-1-4612-4240-6_5.
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Hougardy, Stefan, and Jens Vygen. "Simple Graph Algorithms." In Algorithmic Mathematics. Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-39558-6_7.
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Brandes, Ulrik, and Boris Köpf. "Fast and Simple Horizontal Coordinate Assignment." In Graph Drawing. Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/3-540-45848-4_3.
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Barth, Wilhelm, Michael Jünger, and Petra Mutzel. "Simple and Efficient Bilayer Cross Counting." In Graph Drawing. Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/3-540-36151-0_13.
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Dai, Qionghai, and Yue Gao. "Mathematical Foundations of Hypergraph." In Artificial Intelligence: Foundations, Theory, and Algorithms. Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-0185-2_2.
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AbstractIn this chapter, we introduce the mathematical foundations of hypergraph and present the mathematical notations that are used to facilitate deep understanding and analysis of hypergraph structure. A hypergraph is composed of a set of vertices and hyperedges, and it is a generalization of a graph, where a weighted hypergraph quantifies the relative importance of hyperedges or vertices. Hypergraph can also be divided into two main categories, i.e., the undirected hypergraph representation and the directed hypergraph representation. The latter one further divides the vertices in one hyperedge into the source vertex set and the target vertex set to model more complex correlations. Additionally, we discuss the relationship between hypergraph and graph from the perspective of structural transformation and expressive ability. The most intuitive difference between a simple graph and a hypergraph can be observed in the size of order and expression of adjacency. A hypergraph can be converted into a simple graph using clique expansion, star expansion, and line expansion. Moreover, the proof based on random walks and Markov chains establishes the relationship between hypergraphs with edge-independent vertex weights and weighted graphs.
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Daescu, Ovidiu, and Jun Luo. "Computing Simple Paths on Points in Simple Polygons." In Computational Geometry and Graph Theory. Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-89550-3_5.
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Waltham, David. "More about graphs." In Mathematics: A Simple Tool for Geologists. Springer US, 1994. http://dx.doi.org/10.1007/978-1-4899-4479-5_6.
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Chiaselotti, Giampiero, Davide Ciucci, Tommaso Gentile, and Federico Infusino. "Preclusivity and Simple Graphs." In Lecture Notes in Computer Science. Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-25783-9_12.
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Fairbairn, Jon. "A simple abstract machine to execute supercombinators." In Graph Reduction. Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/3-540-18420-1_49.
Full textConference papers on the topic "Graphe simple"
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Wu, Junran, Shangzhe Li, Jianhao Li, Yicheng Pan, and Ke Xu. "A Simple yet Effective Method for Graph Classification." In Thirty-First International Joint Conference on Artificial Intelligence {IJCAI-22}. International Joint Conferences on Artificial Intelligence Organization, 2022. http://dx.doi.org/10.24963/ijcai.2022/497.
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In deep neural networks, better results can often be obtained by increasing the complexity of previously developed basic models. However, it is unclear whether there is a way to boost performance by decreasing the complexity of such models. Intuitively, given a problem, a simpler data structure comes with a simpler algorithm. Here, we investigate the feasibility of improving graph classification performance while simplifying the learning process. Inspired by structural entropy on graphs, we transform the data sample from graphs to coding trees, which is a simpler but essential structure for graph data. Furthermore, we propose a novel message passing scheme, termed hierarchical reporting, in which features are transferred from leaf nodes to root nodes by following the hierarchical structure of coding trees. We then present a tree kernel and a convolutional network to implement our scheme for graph classification. With the designed message passing scheme, the tree kernel and convolutional network have a lower runtime complexity of O(n) than Weisfeiler-Lehman subtree kernel and other graph neural networks of at least O(hm). We empirically validate our methods with several graph classification benchmarks and demonstrate that they achieve better performance and lower computational consumption than competing approaches.
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Zatesko, Leandro M., Renato Carmo, and André L. P. Guedes. "Novel Procedures for Graph Edge-colouring." In XXXII Concurso de Teses e Dissertações da SBC. Sociedade Brasileira de Computação - SBC, 2019. http://dx.doi.org/10.5753/ctd.2019.6331.
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We present a novel recolouring procedure for graph edge-colouring. We show that all graphs whose vertices have local degree sum not too large can be optimally edge-coloured in polynomial time. We also show that the set ofthe graphs satisfying this condition includes almost every graph (under the uniform distribution). We present further results on edge-colouring join graphs, chordal graphs, circular-arc graphs, and complementary prisms, whose proofs yield polynomial-time algorithms. Our results contribute towards settling the Over- full Conjecture, the main open conjecture on edge-colouring simple graphs. Fi- nally, we also present some results on total colouring.
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Bei, Xiaohui, Youming Qiao, and Shengyu Zhang. "Networked Fairness in Cake Cutting." In Twenty-Sixth International Joint Conference on Artificial Intelligence. International Joint Conferences on Artificial Intelligence Organization, 2017. http://dx.doi.org/10.24963/ijcai.2017/508.
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We introduce a graphical framework for fair division in cake cutting, where comparisons between agents are limited by an underlying network structure. We generalize the classical fairness notions of envy-freeness and proportionality in this graphical setting. An allocation is called envy-free on a graph if no agent envies any of her neighbor's share, and is called proportional on a graph if every agent values her own share no less than the average among her neighbors, with respect to her own measure. These generalizations enable new research directions in developing simple and efficient algorithms that can produce fair allocations under specific graph structures. On the algorithmic frontier, we first propose a moving-knife algorithm that outputs an envy-free allocation on trees. The algorithm is significantly simpler than the discrete and bounded envy-free algorithm introduced in [Aziz and Mackenzie, 2016] for compete graphs. Next, we give a discrete and bounded algorithm for computing a proportional allocation on transitive closure of trees, a class of graphs by taking a rooted tree and connecting all its ancestor-descendant pairs.
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Wang, Huijuan, Siming Dai, Weiyue Su, et al. "Simple and Effective Relation-based Embedding Propagation for Knowledge Representation Learning." In Thirty-First International Joint Conference on Artificial Intelligence {IJCAI-22}. International Joint Conferences on Artificial Intelligence Organization, 2022. http://dx.doi.org/10.24963/ijcai.2022/382.
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Relational graph neural networks have garnered particular attention to encode graph context in knowledge graphs (KGs). Although they achieved competitive performance on small KGs, how to efficiently and effectively utilize graph context for large KGs remains an open problem. To this end, we propose the Relation-based Embedding Propagation (REP) method. It is a post-processing technique to adapt pre-trained KG embeddings with graph context. As relations in KGs are directional, we model the incoming head context and the outgoing tail context separately. Accordingly, we design relational context functions with no external parameters. Besides, we use averaging to aggregate context information, making REP more computation-efficient. We theoretically prove that such designs can avoid information distortion during propagation. Extensive experiments also demonstrate that REP has significant scalability while improving or maintaining prediction quality. Particularly, it averagely brings about 10% relative improvement to triplet-based embedding methods on OGBL-WikiKG2 and takes 5%-83% time to achieve comparable results as the state-of-the-art GC-OTE.
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Ding, Huafeng, Jing Zhao, and Zhen Huang. "The Establishment of Novel Structure Representation Models for Several Kinds of Mechanisms." In ASME 2009 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/detc2009-86074.
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This paper attempts to establish the unified topological models and corresponding mathematical representations for planar simple joint, multiple joint and geared (cam) kinematic chains. First, the conventional topological representation models of kinematic chains are introduced. Then new topological models of multiple joint and geared (cam) kinematic chains, which are derived from the topological graph of simple joint kinematic chains, are presented. The characteristics of the new topological graphs and their associations with the topological graph of simple joint kinematic chains are also addressed. The most important merit of the new topological graphs is that it makes it much easier to do unified structure synthesis and further establish conceptual design platform for various planar mechanisms of these kinds.
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Li, Pengyong, Jun Wang, Ziliang Li, et al. "Pairwise Half-graph Discrimination: A Simple Graph-level Self-supervised Strategy for Pre-training Graph Neural Networks." In Thirtieth International Joint Conference on Artificial Intelligence {IJCAI-21}. International Joint Conferences on Artificial Intelligence Organization, 2021. http://dx.doi.org/10.24963/ijcai.2021/371.
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Self-supervised learning has gradually emerged as a powerful technique for graph representation learning. However, transferable, generalizable, and robust representation learning on graph data still remains a challenge for pre-training graph neural networks. In this paper, we propose a simple and effective self-supervised pre-training strategy, named Pairwise Half-graph Discrimination (PHD), that explicitly pre-trains a graph neural network at graph-level. PHD is designed as a simple binary classification task to discriminate whether two half-graphs come from the same source. Experiments demonstrate that the PHD is an effective pre-training strategy that offers comparable or superior performance on 13 graph classification tasks compared with state-of-the-art strategies, and achieves notable improvements when combined with node-level strategies. Moreover, the visualization of learned representation revealed that PHD strategy indeed empowers the model to learn graph-level knowledge like the molecular scaffold. These results have established PHD as a powerful and effective self-supervised learning strategy in graph-level representation learning.
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Parmacli, Dmitrii, and Serghei Cara. "Evaluating the dynamics of grape production in UTA Gagauzia." In The 8th International Conference "Management Strategies and Policies in the Contemporary Economy". Academy of Economic Studies of Moldova, 2023. http://dx.doi.org/10.53486/icspm2023.10.
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It is emphasized that viticulture in ATU Gagauzia is the most promising sector in agricultural production. An assessment of the dynamics of grape production in the autonomy makes it possible to determine the level of development of the industry, to reveal, to a certain extent, the existing shortcomings and to determine the ways of development. The purpose of the study is to propose a methodology for assessing the state of the dynamics of grape production, confirming its features on specific examples from practice. The object of the study are farms of all categories of ATU Gagauzia for 2012-2021. Evaluation of the dynamics of grape production includes average annual data on planting areas, gross harvest and yield, including for the first and second periods of research, as well as indicators of the stability of the industry. An example of assessing the production of grapes by a separate business entity using the percentile indicator is given. The calculation results are shown on the graphs for clarity. The proposed variant of assessing the state of grape cultivation in dynamics is quite simple and accessible, and therefore can be used by both practitioners and university students
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Campos, Raphael R., Ricardo Ferreira, Julio C. Goldner Vendramini, Fábio Cerqueira, and Marcelo Lobato Martins. "Simulation of Scale Free Gene Regulatory Networks based on Threshold Functions on GPU." In Simpósio em Sistemas Computacionais de Alto Desempenho. Sociedade Brasileira de Computação, 2011. http://dx.doi.org/10.5753/wscad.2011.17271.
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Gene regulatory networks have been used to study diseases and cell evolution, where Random Boolean graphs are one of computational approaches. A Boolean graph is a simple and effective model, and its dynamic behavior has been used in several works. This article proposes an efficient environment to simulate Boolean graph on GPU (Graphics Processing Units). The dynamic behavior of a Boolean graph is computed by visiting the whole or a subset of state space. The proposed tool is based on statistical approaches to evaluate large graphs. Moreover, it can take into account scale free graphs with threshold functions. The experimental results show a speed-up factor of up to 40 times. In addition, the exploration of state spaces three orders of magnitude greater than previous approaches have been evaluated.
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Klobas, Nina, and Matjaž Krnc. "Fast Recognition of Some Parametric Graph Families." In 7th Student Computer Science Research Conference. University of Maribor Press, 2021. http://dx.doi.org/10.18690/978-961-286-516-0.7.
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Recognizing graphs with high level of symmetries is hard in general, and usually requires additional structural understanding. In this paper we study a particular graph parameter and motivate its usage by devising eÿcient recognition algorithm for the family of I-graphs. For integers m a simple graph is cycle regular if every path of length ` belongs to exactly cycles of length m. We identify all cycle regular I-graphs and, as a conse-quence, describe linear recognition algorithm for the observed family. Similar procedure can be used to devise the recog-nition algorithms for Double generalized Petersen graphs and folded cubes. Besides that, we believe the structural observations and methods used in the paper are of independent interest and could be used for solving other algorithmic problems.
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Ding, Huafeng, Peng Huang, Zhen Huang, and Andrés Kecskeméthy. "An Automatic Method for Sketching of Planar Simple and Multiple Joint Kinematic Chains." In ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/detc2015-47216.
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The sketching of mechanisms (kinematic chains) shows designers a visual understanding of the interrelationship among links and joints in mechanical design, but sketching of mechanisms in manually in conceptual design stage is time-consuming and inefficient. In this paper, a fully-automatic method for sketching of planar simple and multiple joint kinematic chains is proposed. First, the complete sets of the topological structures (topological graphs and contracted graphs) of both simple and multiple joint kinematic chains are introduced. Then an algorithm for the layouts of the contracted graphs with minimal edge crossings is proposed. Third, the expression set of binary sub-paths derived from a topological graph is obtained for the sketching of the simple joint kinematic chain, and based on the sketching of the simple joint kinematic chains the sketching of corresponding multiple joint kinematic chains is obtained. Finally, both simple and multiple joint kinematic chains with numbers of links and numbers of basic loops are provided in batch as examples to show the effectiveness of the method.
Reports on the topic "Graphe simple"
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Green, Alastair, Paolo Guagliardo, and Leonid Libkin. Property graphs and paths in GQL: Mathematical definitions. Linked Data Benchmark Council, 2021. http://dx.doi.org/10.54285/ldbc.tzjp7279.
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This paper provides precise mathematical definitions of a property graph as specified in the proposed GQL international standard, which is an attributed mixed multigraph with loops. It further defines a partially-oriented walk in such a property graph, which is called a path in GQL, as well as restricted classes of such walks (trails, simple/acyclic paths).
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Pinzon, Mauricio, and Arturo Galindo. Revelation of Expectations in Latin America (REVELA): No. 17 : September, 2008. Inter-American Development Bank, 2008. http://dx.doi.org/10.18235/0008250.
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REVELA analyzes market expectations of growth and inflation in Latin American countries. The figures analyzed represent the results of surveys of private sector actors conducted by the central banks of each country according to their own specific methodologies. They do not represent official projections by the IDB or any other official body. RES collects the results of these surveys from participating central banks on a monthly basis to produce a report and a set of illustrative graphs and tables. The September issue of REVELA reports that growth expectations for 2008 are almost unchanged with respect to last month's survey. Now the simple average expected growth rate is 5.29%. However, growth is expected to slow in 2009, to an average of 4.7%, slightly down from last month 4.8% 2009 forecast. On the other hand, the expected inflation rate for 2008 increased from 9.43% to 9.59%. Inflation expectations for 2009 decreased, reaching a simple average of 8.63%.
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Galindo, Arturo, and Mauricio Pinzon. Revelation of Expectations in Latin America (REVELA): No. 23 : March, 2009. Inter-American Development Bank, 2009. http://dx.doi.org/10.18235/0008255.
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REVELA analyzes market expectations of growth and inflation in Latin American countries. The figures analyzed represent the results of surveys of private sector actors conducted by the central banks of each country according to their own specific methodologies. They do not represent official projections by the IDB or any other official body. RES collects the results of these surveys from participating central banks on a monthly basis to produce a report and a set of illustrative graphs and tables. In this March issue, REVELA reports that growth expectations for 2009 decreased with respect to last month's survey. Now the simple average expected growth rate is 1.91%. In the same way, growth is expected to slow in 2010, to an average of 3.29%, down from last month's 3.62% 2010 forecast. On the other hand, the expected inflation rate for 2009 decreased from 7.25% to 6.66%. The simple average of the expected inflation rate for 2010 is 5.99%.
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Salazni, Mariana, Andrew Powell, Mauricio Pinzon, and Arturo Galindo. Revelation of Expectations in Latin America (REVELA): No. 16 : August, 2008. Inter-American Development Bank, 2008. http://dx.doi.org/10.18235/0008249.
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REVELA analyzes market expectations of growth and inflation in Latin American countries. The figures analyzed represent the results of surveys of private sector actors conducted by the central banks of each country according to their own specific methodologies. They do not represent official projections by the IDB or any other official body. RES collects the results of these surveys from participating central banks on a monthly basis to produce a report and a set of illustrative graphs and tables. In this August issue, REVELA reports that growth expectations for 2008 are almost unchanged with respect to last month's survey. Now the simple average expected growth rate is 5.31%. However, growth is expected to slow in 2009, to an average of 4.8%, slightly down from last month 4.9% 2009 forecast. On the other hand, inflation expectations continue to rise; the expected inflation rate for 2008 increased from 8.95% to 9.43%. Inflation expectations for 2009 have also increased, reaching a simple average of 8.4%.
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Pinzon, Mauricio, and Arturo Galindo. Revelation of Expectations in Latin America (REVELA): No. 21 : January, 2009. Inter-American Development Bank, 2009. http://dx.doi.org/10.18235/0008253.
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REVELA analyzes market expectations of growth and inflation in Latin American countries. The figures analyzed represent the results of surveys of private sector actors conducted by the central banks of each country according to their own specific methodologies. They do not represent official projections by the IDB or any other official body. RES collects the results of these surveys from participating central banks on a monthly basis to produce a report and a set of illustrative graphs and tables. In this January issue, REVELA reports that growth expectations for 2009 decreased with respect to last month's survey. Now the simple average expected growth rate is 2.97%. In the same way, growth is expected to slow in 2010, to an average of 3.54%, down from last month's 3.62% 2010 forecast. On the other hand, the expected inflation rate for 2009 decreased from 8.09% to 7.56%. The simple average of the expected inflation rate for 2010 is 5.96%.
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Pinzon, Mauricio, and Arturo Galindo. Revelation of Expectations in Latin America (REVELA): No. 20 : December, 2008. Inter-American Development Bank, 2008. http://dx.doi.org/10.18235/0008252.
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REVELA analyzes market expectations of growth and inflation in Latin American countries. The figures analyzed represent the results of surveys of private sector actors conducted by the central banks of each country according to their own specific methodologies. They do not represent official projections by the IDB or any other official body. RES collects the results of these surveys from participating central banks on a monthly basis to produce a report and a set of illustrative graphs and tables. In this December issue, REVELA reports that growth expectations for 2008 decreased with respect to last month's survey. Now the simple average expected growth rate is 5.22%. In the same way, growth is expected to slow in 2009, to an average of 3.12%, down from last month's 3.80% 2009 forecast. On the other hand, the expected inflation rate for 2008 decreased from 9.47% to 9.24%. Inflation expectations for 2009 decreased, reaching a simple average of 8.09%.
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Pinzon, Mauricio, and Arturo Galindo. Revelation of Expectations in Latin America (REVELA): No. 18 : October, 2008. Inter-American Development Bank, 2008. http://dx.doi.org/10.18235/0008251.
Full textAbstract:
REVELA analyzes market expectations of growth and inflation in Latin American countries. The figures analyzed represent the results of surveys of private sector actors conducted by the central banks of each country according to their own specific methodologies. They do not represent official projections by the IDB or any other official body. RES collects the results of these surveys from participating central banks on a monthly basis to produce a report and a set of illustrative graphs and tables. In this October issue, REVELA reports that growth expectations for 2008 increased with respect to last month's survey. Now the simple average expected growth rate is 5.45%. However, growth is expected to slow in 2009, to an average of 4.4%, down from last month 4.7% 2009 forecast. On the other hand, the expected inflation rate for 2008 increased from 9.59% to 9.66%. Inflation expectations for 2009 decreased, reaching a simple average of 8.38%.
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Galindo, Arturo, and Mauricio Pinzon. Revelation of Expectations in Latin America (REVELA): No. 22 : February, 2009. Inter-American Development Bank, 2009. http://dx.doi.org/10.18235/0008254.
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REVELA analyzes market expectations of growth and inflation in Latin American countries. The figures analyzed represent the results of surveys of private sector actors conducted by the central banks of each country according to their own specific methodologies. They do not represent official projections by the IDB or any other official body. RES collects the results of these surveys from participating central banks on a monthly basis to produce a report and a set of illustrative graphs and tables. In this February issue, REVELA reports that growth expectations for 2009 decreased with respect to last month's survey. Now the simple average expected growth rate is 2.66%. In the same way, growth is expected to slow in 2010, to an average of 3.34%, down from last month's 3.54% 2010 forecast. On the other hand, the expected inflation rate for 2009 decreased from 7.56% to 7.25%. The simple average of the expected inflation rate for 2010 is 5.63%.
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Striuk, Andrii, Olena Rybalchenko, and Svitlana Bilashenko. Development and Using of a Virtual Laboratory to Study the Graph Algorithms for Bachelors of Software Engineering. [б. в.], 2020. http://dx.doi.org/10.31812/123456789/4462.
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The paper presents an analysis of the importance of studying graph algorithms, the reasons for the need to implement this project and its subsequent use. The existing analogues analysis is carried out, due to which a list of advantages and disadvantages is formed and taken into account in developing the virtual laboratory. A web application is created that clearly illustrates the work of graph algorithms, such as Depth-First Search, Dijkstra’s Shortest Path, Floyd- Warshall, Kruskal Minimum Cost Spanning Tree Algorithm. A simple and user- friendly interface is developed and it is supported by all popular browsers. The software product is provided with user registration and authorization functions, chat communication, personal cabinet editing and viewing the statistics on web- application use. An additional condition is taken into account at the design stage, namely the flexibility of the architecture, which envisaged the possibility of easy expansion of an existing functionality. Virtual laboratory is used at Kryvyi Rih National University to training students of specialty 121 Software Engineering in the disciplines “Algorithms and Data Structures” and “Discrete Structures”.
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Lichter, Amnon, Joseph L. Smilanick, Dennis A. Margosan, and Susan Lurie. Ethanol for postharvest decay control of table grapes: application and mode of action. United States Department of Agriculture, 2005. http://dx.doi.org/10.32747/2005.7587217.bard.
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Original objectives: Dipping of table grapes in ethanol was determined to be an effective measure to control postharvest gray mold infection caused by Botrytis cinerea. Our objectives were to study the effects of ethanol on B.cinerea and table grapes and to conduct research that will facilitate the implementation of this treatment. Background: Botrytis cinerea is known as the major pathogen of table grapes in cold storage. To date, the only commercial technology to control it relied on sulfur dioxide (SO₂) implemented by either fumigation of storage facilities or from slow release generator pads which are positioned directly over the fruits. This treatment is very effective but it has several drawbacks such as aftertaste, bleaching and hypersensitivity to humans which took it out of the GRAS list of compounds and warranted further seek for alternatives. Prior to this research ethanol was shown to control several pathogens in different commodities including table grapes and B. cinerea. Hence it seemed to be a simple and promising technology which could offer a true alternative for storage of table grapes. Further research was however required to answer some practical and theoretical questions which remained unanswered. Major conclusions, solutions, achievements: In this research project we have shown convincingly that 30% ethanol is sufficient to prevent germination of B. cinerea and kill the spores. In a comparative study it was shown that Alternaria alternata is also rather sensitive but Rhizopus stolonifer and Aspergillus niger are less sensitive to ethanol. Consequently, ethanol protected the grapes from decay but did not have a significant effect on occurrence of mycotoxigenic Aspergillus species which are present on the surface of the berry. B. cinerea responded to ethanol or heat treatments by inducing sporulation and transient expression of the heat shock protein HSP104. Similar responses were not detected in grape berries. It was also shown that application of ethanol to berries did not induce subsequent resistance and actually the berries were slightly more susceptible to infection. The heat dose required to kill the spores was determined and it was proven that a combination of heat and ethanol allowed reduction of both the ethanol and heat dose. Ethanol and heat did not reduce the amount or appearance of the wax layers which are an essential component of the external protection of the berry. The ethanol and acetaldehyde content increased after treatment and during storage but the content was much lower than the natural ethanol content in other fruits. The efficacy of ethanol applied before harvest was similar to that of the biological control agent, Metschnikowia fructicola, Finally, the performance of ethanol could be improved synergistically by packaging the bunches in modified atmosphere films which prevent the accumulation of free water. Implications, both scientific and agricultural: It was shown that the major mode of action of ethanol is mediated by its lethal effect on fungal inoculum. Because ethanol acts mainly on the cell membranes, it was possible to enhance its effect by lowering the concentration and elevating the temperature of the treatment. Another important development was the continuous protection of the treated bunches by modified atmosphere that can solve the problem of secondary or internal infection. From the practical standpoint, a variety of means were offered to enhance the effect of the treatment and to offer a viable alternative to SO2 which could be instantly adopted by the industry with a special benefit to growers of organic grapes.