Teses / dissertações sobre o tema "Variation graph"
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Kural, Deniz. "Methods for Inter- and Intra-Species Genomics for the Detection of Variation and Function". Thesis, Boston College, 2014. http://hdl.handle.net/2345/bc-ir:104053.
Texto completo da fonteThis thesis concerns itself with the development of methods for comparing genomes. Chapter 2 is a comparative genomics investigation of coding regions across multiple species. Regions of the genome coding for proteins show higher conservation than non-coding regions. Furthermore, we show that a portion of coding regions are conserved beyond the requirements of protein conservation, supporting functions such as microRNA binding and splicing enhancement, providing the non-coding functional impetus to conservation. In Chapter 3, we focus on the detection and characterization of a particular type of structural variation - mobile element insertions (MEIs). While there are many types of mobile elements in the human genome, three of these are active and cause most of the MEI variation observed in humans: ALU, L1 and SVA elements. We detect variation across 1000 Genomes Pilot populations caused by these elements, assemble ALU elements to single nucleotide resolution, and determine actively copying species of this element. We've developed a variety of algorithmic approaches to MEI detection, and present these. Chapter 4 outlines an approach to remedy reference bias via the incorporation of variation data into the reference. In particular, we construct a pan-genome reference, demonstrated concretely via resolving ALU regions, and develop new alignment software to align against this enriched reference structure
Thesis (PhD) — Boston College, 2014
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Biology
Romain, Sandra. "Identification, génotypage et représentation des variants de structure dans les pangénomes". Electronic Thesis or Diss., Université de Rennes (2023-....), 2024. https://ged.univ-rennes1.fr/nuxeo/site/esupversions/71b8c90f-bac9-4948-9bb1-a4b6d953f322.
Texto completo da fonteStructural variants (SVs), genomic variations of more than 50 bp, contribute significantly to genetic diversity and species evolution. Accurate detection and genotyping SVs is crucial to understanding their role in phenotypic variation and adaptation. Variation graphs (VGs) and pangenome graphs (PGs), which represent genomic variations as alternative paths in a graph, offer a promising approach for the analysis of SVs. This thesis explores the use of VGs and PGs for the detection and genotyping of SVs, focusing on a complex of four species of alpine Coenonympha butterflies. Two bioinformatics tools were developed during this thesis: (1) SVJedi-graph, the first long-read SV genotyper using a VG to represent SVs, providing a genotyping accuracy superior to state-of-the-art tools, particularly for close and overlapping SVs, and (2) INVPG-annot, a tool for identifying inversions in PGs, which demonstrated that inversions are represented by different topologies in PGs depending on the construction tool used. Comparative analysis of the Coenonympha butterfly genomes identified twelve large inversions (≥ 100 kbp) between the four species, some of which could play a role in the reproductive isolation and local adaptation of two of these species. While the PG-based approach offers advantages for genome comparison, challenges remain for the analysis of large variants such as inversions
Jaillard, Dancette Magali. "Vers une cartographie fine des polymorphismes liés à la résistance aux antimicrobiens". Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1282/document.
Texto completo da fonteThe emergence and spread of multi-drug resistance has become a major worldwide public health concern, calling for better understanding of the underlying resistance mechanisms. Genome-wide association studies are powerful tools to finely map the genetic polymorphism linked to the phenotypic variability observed in a population. However well documented for eukaryotic genome analysis, these studies were only recently applied to prokaryota.Through this PhD project, I searched how to better adapt these tools to the highly plastic bacterial genomes, mainly by working on the representation of the genetic variations in these genomes. Indeed, because the bacteria have the faculty to acquire genetic material by a means other than direct inheritance from a parent cell, their genomes can differ too much within a species to be aligned against a reference. A representation using sequence fragments of length k - the so-called k-mers - offers the required flexibility but generates redundancy and does not allow for a direct interpretation of the identified associations. The method we set up tests the association of these k-mers with the phenotype, and takes advantage of a De Bruijn graph (DBG) built over all genomes to remove the local redundancy of k-mers, and offer a visualisation of the genomic context of the k-mers identified by the test. This synthetic view as DBG subgraphs informs on the nature of the identified sequence: e.g. local polymorphism in a gene or gene acquired through a plasmid. The type of variant can be predicted correctly in 96% of the cases from descriptors of the subgraphs, providing a tractable framework for k-mer-based association studies
Yeo, Ronald A., Sephira G. Ryman, den Heuvel Martijn P. van, Reus Marcel A. de, Rex E. Jung, Jessica Pommy, Andrew R. Mayer et al. "Graph Metrics of Structural Brain Networks in Individuals with Schizophrenia and Healthy Controls: Group Differences, Relationships with Intelligence, and Genetics". Cambridge University Press, 2016. https://tud.qucosa.de/id/qucosa%3A70691.
Texto completo da fonteMeinhardt, Llopis Enric. "Morphological and statistical techniques for the analysis of 3D images". Doctoral thesis, Universitat Pompeu Fabra, 2011. http://hdl.handle.net/10803/22719.
Texto completo da fonteThis thesis proposes a tree data structure to encode the connected components of level sets of 3D images. This data structure is applied as a main tool in several proposed applications: 3D morphological operators, medical image visualization, analysis of color histograms, object tracking in videos and edge detection. Motivated by the problem of edge linking, the thesis contains also an study of anisotropic total variation denoising as a tool for computing anisotropic Cheeger sets. These anisotropic Cheeger sets can be used to find global optima of a class of edge linking functionals. They are also related to some affine invariant descriptors which are used in object recognition, and this relationship is laid out explicitly.
Jacob, Jobby. "Variations on graph products and vertex partitions". Connect to this title online, 2009.
Encontre o texto completo da fonteSonnerat, Nicolas. "Galaxy cutsets and graph connectivity: variations on a theme". Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97002.
Texto completo da fonteDans cette thèse, nous considerons des séparateurs dans les graphes qui peuvent être éxprimés sous forme d'une union d'ensembles de sommets dans laquelle chaque ensemble est couvert par un arbre de diamètre d-1 pour un nombre entier d ≥ 1; nous appellons ces séparateurs des galaxies séparatrices. Les galaxies séparatrices genéralisent les étoiles séparatrices et les séparateurs formés par un ensemble de sommets, et elles servent comme simple modèle pour des attaques de virus sur ou des cascades de défaillances dans un réseau, la proprieté distinguante étant que les voisins des sommets qui sont affectés peuvent eux aussi faillir. Nous approchons le sujet depuis quatre points de vue différents. Nous commençons par explorer le lien entre les galaxies et un type de flot approprié, et nous prouvons un résultat de type min max pour les graphes planaires. Ensuite, après avoir résolu la question fondamentale de reconnaitre si un graphe donné est sensible aux attaques de virus, c'est-à-dire s'il contient une galaxie séparatrice, nous introduisons des capacités dans les flots correspondants aux galaxies, et demontrons une borne d'approximabilité inférieure et supérieure de Θ(log n)pour le problème de trouver un flot maximum. Ensuite, nous enquêtons sur le problème de dessein de réseau, c'est-à-dire le problème de construire des sous-graphes couvrants peu coûteux qui ne sont pas sensibles aux cascades de défaillances. Finalement, nous nous lançons dans une analyse détaillée de la structure des étoiles séparatrices dans les graphes planaires, et nous utilisons nos résultats pour développer un algorithme polynomial qui résout le problème de neutraliser toutes les étoiles séparatrices en protégeant des arêtes.
Pandey, Arti. "Algorithmic aspects of domination and its variations". Thesis, IIT Delhi, 2016. http://localhost:8080/xmlui/handle/12345678/7038.
Texto completo da fonteTrillos, Nicolás Garcia. "Variational Limits of Graph Cuts on Point Clouds". Research Showcase @ CMU, 2015. http://repository.cmu.edu/dissertations/518.
Texto completo da fonteCouprie, Camille. "Graph-based variational optimization and applications in computer vision". Phd thesis, Université Paris-Est, 2011. http://tel.archives-ouvertes.fr/tel-00666878.
Texto completo da fonteMinichiello, Mark Joseph. "Analysis of genetic variation data using ancestral recombination graphs". Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613255.
Texto completo da fonteKumar, Sooraj. "Face recognition with variation in pose angle using face graphs /". Online version of thesis, 2009. http://hdl.handle.net/1850/9482.
Texto completo da fonteGray, John D. "The basis of variation in the size and composition of grape berries". Title page, contents and abstract only, 2002. http://web4.library.adelaide.edu.au/theses/09PH/09phg7794.pdf.
Texto completo da fonteVorwerk, Sonja. "Molecular evidence of intraclonal variation and implications for adaptational traits of grape phylloxera populations (Daktulosphaira vitifoliae, Fitch)". [S.l. : s.n.], 2007. http://nbn-resolving.de/urn:nbn:de:bsz:100-opus-2086.
Texto completo da fonteHafiene, Yosra. "Continuum limits of evolution and variational problems on graphs". Thesis, Normandie, 2018. http://www.theses.fr/2018NORMC254/document.
Texto completo da fonteThe non-local p-Laplacian operator, the associated evolution equation and variational regularization, governed by a given kernel, have applications in various areas of science and engineering. In particular, they are modern tools for massive data processing (including signals, images, geometry), and machine learning tasks such as classification. In practice, however, these models are implemented in discrete form (in space and time, or in space for variational regularization) as a numerical approximation to a continuous problem, where the kernel is replaced by an adjacency matrix of a graph. Yet, few results on the consistency of these discretization are available. In particular it is largely open to determine when do the solutions of either the evolution equation or the variational problem of graph-based tasks converge (in an appropriate sense), as the number of vertices increases, to a well-defined object in the continuum setting, and if yes, at which rate. In this manuscript, we lay the foundations to address these questions.Combining tools from graph theory, convex analysis, nonlinear semigroup theory and evolution equa- tions, we give a rigorous interpretation to the continuous limit of the discrete nonlocal p-Laplacian evolution and variational problems on graphs. More specifically, we consider a sequence of (determin- istic) graphs converging to a so-called limit object known as the graphon. If the continuous p-Laplacian evolution and variational problems are properly discretized on this graph sequence, we prove that the solutions of the sequence of discrete problems converge to the solution of the continuous problem governed by the graphon, as the number of graph vertices grows to infinity. Along the way, we provide a consistency/error bounds. In turn, this allows to establish the convergence rates for different graph models. In particular, we highlight the role of the graphon geometry/regularity. For random graph se- quences, using sharp deviation inequalities, we deliver nonasymptotic convergence rates in probability and exhibit the different regimes depending on p, the regularity of the graphon and the initial data
Forneck, Astrid. "Genetic variation and differences in host performance of grape phylloxera (Daktulosphaira vitifoliae Fitch) /". Stuttgart : Grauer, 1999. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=009158066&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Texto completo da fonteSmith, Andrew Duncan. "Total variation denoising and multiresolution on graphs, with applications to house price data". Thesis, University of Bristol, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.540873.
Texto completo da fonteLee, Sunmi. "The edge-isoperimetric problem for the square tessellation of plane". CSUSB ScholarWorks, 2000. https://scholarworks.lib.csusb.edu/etd-project/1622.
Texto completo da fonteWainwright, Martin J. (Martin James) 1973. "Stochastic processes on graphs with cycles : geometric and variational approaches". Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/8371.
Texto completo da fonteIncludes bibliographical references (leaves 259-271).
Stochastic processes defined on graphs arise in a tremendous variety of fields, including statistical physics, signal processing, computer vision, artificial intelligence, and information theory. The formalism of graphical models provides a useful language with which to formulate fundamental problems common to all of these fields, including estimation, model fitting, and sampling. For graphs without cycles, known as trees, all of these problems are relatively well-understood, and can be solved efficiently with algorithms whose complexity scales in a tractable manner with problem size. In contrast, these same problems present considerable challenges in general graphs with cycles. The focus of this thesis is the development and analysis of methods, both exact and approximate, for problems on graphs with cycles. Our contributions are in developing and analyzing techniques for estimation, as well as methods for computing upper and lower bounds on quantities of interest (e.g., marginal probabilities; partition functions). In order to do so, we make use of exponential representations of distributions, as well as insight from the associated information geometry and Legendre duality. Our results demonstrate the power of exponential representations for graphical models, as well as the utility of studying collections of modified problems defined on trees embedded within the original graph with cycles. The specific contributions of this thesis include the following. We develop a method for performing exact estimation of Gaussian processes on graphs with cycles by solving a sequence of modified problems on embedded spanning trees.
(cont.) We introduce the tree-based reparameterization framework for approximate estimation of discrete processes. This perspective leads to a number of theoretical results on belief propagation and related algorithms, including characterizations of their fixed points and the associated approximation error. Next we extend the notion of reparameterization to a much broader class of methods for approximate inference, including Kikuchi methods, and present results on their fixed points and accuracy. Finally, we develop and analyze a novel class of upper bounds on the log partition function based on convex combinations of distributions in the exponential domain. In the special case of combining tree-structured distributions, the associated dual function gives an interesting perspective on the Bethe free energy.
by Martn J. Wainwright.
Ph.D.
Kong, Junhua. "Analysis of genomic DNA methylation variations and roles during grape berry ripening". Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0095.
Texto completo da fonteGrapevine is a worldwide cultivated fruit crop with high economic importance mainly because of its usage for vine production. Grape berry is also one of the main models for non-climacteric fruits to study the mechanisms controlling the ripening process. Grape berry development is characterized by two phases of rapid size increase separated by a lag phase at the time of ripening induction. Grape berries are composed of three main tissues, the peel, the pulp and the seeds. Peel and pulp present distinct structure and metabolite composition and contribute in a different way to wine quality, the pulp providing sugar, amino and organic acids whereas the peel is important for anthocyanins and other phenolic compound abundance. At the present time, the molecular mechanisms involved in the control of grape berry ripening are still poorly understood. Recent results indicate that both ABA and sugar may be important signals together with various transcription factors. In addition, epigenetic mechanisms are now emerging as important regulators of fleshy fruit development, DNA methylation being critically important for tomato, sweet range and strawberry ripening.The present project aims at analyzing the potential role of DNA methylation in the control grape berry ripening. It also investigates the potential role of DNA methylation in the synthesis of anthocyanins, a compound of primary importance in peel of red grape berries, using in vitro grown fruit cells. To address these questions, grape berries cultivated in vitro were treated with DNA methylation inhibitors. Treatments resulted in delayed and reduced grape berry ripening, therefore sustaining the idea that DNA methylation plays critical roles at this developmental step. Grape berries harvested at various developmental stages were then dissected and each tissue was separately analyzed for transcriptomic, metabolic and DNA methylation variations. Main results indicate significant and distinct metabolic and transcriptomic variations consistent with each tissue following specific modifications during ripening. In addition, analysis of DNA methylation variations at two developmental stages in each tissue indicates both common and tissue specific changes in DNA methylation patterns during fruit ripening. A very small proportion of DMRs is found similarly in the pup and the peel, but most are tissue specific, also consistent with tissue specific control at this developmental phase. Of note, among the different DMRs identified in each tissue, only a few were associated with differentially expressed genes (DEG) during ripening, whereas most were not, questioning the general role of DNA methylation in the control of gene expression at this developmental transition in grape.As Anthocyanins are the most abundant polyphenolic compounds in the skin of red grape berries, we used grape cell suspensions of the Gamay Teinturier genotype, that are known to accumulate anthocyanins when grown in light conditions, to analyze the potential role of DNA methylation in their synthesis. GT cells cultivated in light conditions were treated with the DNA methyltransferase inhibitor zebularine, they accumulate higher quantities of anthocyanins. Of note, GT cells grown in the absence of light do not accumulate anthocyanins. However, zebularine was sufficient to induce anthocyanin accumulation in the absence of light. Zebularine treatments had significant additional effects on grape cells including, cell growth limitation, and modification of soluble sugar, organic acid or stilbene accumulation, together with important transcriptomic reprogramming, consistent with a general effect on cells rather than a specific effect on anthocyanin accumulation.Taken together, results are consistent with DNA methylation being important in the control of grape fruit ripening, although the precise mechanisms underlying methylation variations and roles in grape berries remain to be deciphered
Al-fatesh, Ibrahim Yahya. "Toxic levels of aluminum and manganese and variation of nitrogen content in grape leaves". Diss., The University of Arizona, 1990. http://hdl.handle.net/10150/185085.
Texto completo da fonteBui, Hoa. "Extremality and stationarity of collections of sets : metric, slope and normal cone characterisations". Thesis, Federation University of Australia, 2019. http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/178600.
Texto completo da fonteDoctor of Philosophy
Landrieu, Loïc. "Learning structured models on weighted graphs, with applications to spatial data analysis". Thesis, Paris Sciences et Lettres (ComUE), 2016. http://www.theses.fr/2016PSLEE046/document.
Texto completo da fonteModeling complex processes often involve a high number of variables with anintricate correlation structure. For example, many spatially-localized processes display spatial regularity, as variables corresponding to neighboring regions are more correlated than distant ones. The formalism of weighted graphs allows us to capture relationships between interacting variables in a compact manner, permitting the mathematical formulation of many spatial analysis tasks. The first part of this manuscript focuses on optimization problems with graph-structure dregularizers, such as the total variation or the total boundary size. We first present the convex formulation and its resolution with proximal splitting algorithms. We introduce a new preconditioning scheme for the existing generalized forward-backward proximal splitting algorithm, specifically designed for graphs with high variability in neighbourhood configurations and edge weights. We then introduce a new algorithm, cut pursuit, which used the links between graph cuts and total variation in a working set scheme. We also present a variation of this algorithm which solved the problem regularized by the non convex total boundary length penalty. We show that our proposed approaches reach or outperform state-of-the-art for geostatistical aggregation as well as image recovery problems. The second part focuses on the development of a new model, expanding continuous-time Markov chain models to general undirected weighted graphs. This allows us to take into account the interactions between neighbouring nodes in structured classification, as demonstrated for a supervised land-use classification task from cadastral data
Calatroni, Luca. "New PDE models for imaging problems and applications". Thesis, University of Cambridge, 2016. https://www.repository.cam.ac.uk/handle/1810/256139.
Texto completo da fonteSalavessa, Isabel. "Graphs with parallel mean curvature and a variational problem in conformal geometry". Thesis, University of Warwick, 1987. http://wrap.warwick.ac.uk/99902/.
Texto completo da fontePeterson, Nicholas Richard. "On Random k-Out Graphs with Preferential Attachment". The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1370527839.
Texto completo da fonteKhachatryan, Anush [Verfasser]. "Extensions and variations of the two-person game on graphs / Anush Khachatryan. Fakultät für Mathematik". Bielefeld : Universitätsbibliothek Bielefeld, Hochschulschriften, 2012. http://d-nb.info/1024640698/34.
Texto completo da fonteChbani, Zaki. "Convergence épigraphique des fonctions et convergence en graphe des opérateurs : Quelques applications en calcul des variations". Montpellier 2, 1993. http://www.theses.fr/1993MON20075.
Texto completo da fonteCarrier, Grégory. "Bases moléculaires de la variation clonale chez la vigne (Vitis vinifera L.) : approche pangénomique". Thesis, Montpellier, SupAgro, 2011. http://www.theses.fr/2011NSAM0039/document.
Texto completo da fonteClonal variation is considered as an effective contribution to breeding programs of vegetatively propagated species with major agronomical interest such as banana, potato, coffee and grape. Indeed, after several propagation cycles, stable and heritable phenotypic variations appear giving rise to a phenotypic variation termed “clonal diversity”. This clonal diversity is very important for wine-growers because it allows preserving cultivars identity in the strict respect of Appellation (A.O.P) wines specifications The most parsimonious hypothesis explaining clonal phenotypic diversity is the accumulation of somatic mutations. The objective of my thesis was to provide a broad description of molecular polymorphisms in the context of vegetative propagation. Three clones were first sequenced by 454 GS-FLX technology and eleven clones were then sequenced with Illumina Hiseq2000 technique. To analyse the high quantity of data obtained, we built a pipeline (Bacchus pipeline) allowing the identification of all existing molecular polymorphisms between different genomes.All polymorphism types were observed: indels and SNPs which have a low polymorphism frequency (2.5 SNPs and 11.5 indels per Mb between two clones in average) and structural variations (large insertions or deletions) which have a high polymorphism frequency (129 per Mb between two clones in average) but are unstable. To evaluate stability and polymorphism level of these transposable elements, we have studied 4 elements using S-SAP method at different diversity levels (inter-species, inter-cultivars, inter-clones and between organs/tissues of a single individual). Our interspecific phylogenetic analysis is similar to other phylogenies performed with SSR or SNPs markers. However, we confirm the high instability of these elements between clones and between tissues in single individuals.Clone identification through molecular methods would be of high significance for the wine industry. SNP or small indels mutations are less frequent but more stable than structural variation and could be used for accurate clone identification
Sibel, Jean-Christophe. "Region-based approximation to solve inference in loopy factor graphs : decoding LDPC codes by the Generalized Belief Propagation". Phd thesis, Université de Cergy Pontoise, 2013. http://tel.archives-ouvertes.fr/tel-00905668.
Texto completo da fonteLe, Corre Gaëlle. "Variations non standard dans les écrits épistolaires de soldats de l'armée confédérée de l'état de Virginie". Thesis, Brest, 2015. http://www.theses.fr/2015BRES0063.
Texto completo da fonteThroughout the Civil War (1861-1865), thousands of low ranking soldiers on both sides of the conflict took up their pens to inquire after their families and give news from the front. Usually semiliterate, most of these soldiers were far from mastering written conventions. The 170,000-word corpus, on which this thesis is based, is composed of 366 letters written by 80 privates, corporals and sergeants from Virginia. Their idiosyncratic and ingenuous spellings as well as their use of non-standard morphosyntactic variations offer a great opportunity to gain further insight into the vernacular spoken by white lower-class people in Virginia around the middle of the 19th century.According to Guy Bailey (1997), certain specificities of the Southern American Vernacular English (SAVE) appeared after the Civil War, as a reaction against Northern domination and the humiliation caused by the defeat. The non standard variations found in the Virginia Civil War Corpus tend to question this hypothesis and reveal that most of the features, that are today associated with SAVE, were already present in low ranking soldiers' writings.Despite the phonetic spelling and the use of non-standard grammatical and lexical forms, the letters reveal that the soldiers were fully aware that their vernacular speech was not in line with academic conventions. We thus observe a constant tension between the academic prescriptive norm and non-standard variations. We may wonder if this constant oscillation is only triggered by an internal conflict between different linguistic models or if, on the contrary, the presence of these dialectal variations must be understood as signs of specific enunciative operations
Goudin, Yoann. "L'intercompréhension en langues sinogrammiques : théories, représentations, enjeux, et modalités d'une didactique de la variation". Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCF035.
Texto completo da fonteThis doctoral thesis analyzes the current teaching and learning models among languages that were, and still are, in contact with the Chinese script, and that retain this influence in their modern lexicon : the sinogramic languages. This thesis asserts that such a course can be designed through a complete didactic reformulation of how to teach sinograms, not only in their graphic dimension, but also their phonological identity, in order for the student to imagine pronouncing a sinogram in the target-language according to his/her understanding of an already acquired 'bridge-language'. The thesis is divided into three parts. First, there is an epistemological discussion of the European approach to Chinese language and script, with the sole graphic - «ideographic» - focus, which shadowed traditional phonological practices. Next, the design of an alternative approach is proposed in which sinogram-based learning is not rooted in the so called concentrated approach, according to which sinogram types are selected in order of their frequency and adaptability within the contemporary lexicon. This alternative approach is discussed based on the training of the sinogramic system as a whole: the global approach. Finally, the main process for mutual understanding, which is called sinogramic transposition, is introduced to show how students can be trained to understand and produce readings of sinograms in the target-language
Jones, Bevan Keeley. "Learning words and syntactic cues in highly ambiguous contexts". Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/15959.
Texto completo da fonteMeister, Julio César. "Tracker Physics : objetos em movimento e registros de representação". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/150248.
Texto completo da fonteThis research brings a study about the initial construction of the concepts of limits and rate of variation, with students of the second year of High School of the School Antônio de Castro Alves. As methodology we use the case study perspective (PONTE, 2006). The work proposes the use of Tracker Physics software, which enables the analysis of moving objects recorded by video from different records generated by the software, such as graphs, tables and algebraic records. With the use of this software and Duval's theory, we try to answer the following guiding question: how do the students of the High School understand the concepts of rate of variation and limit from moving objects analyzed with Tracker Physics? Because we are dealing with moving objects, we use Physics as the means to work on mathematical concepts. Before we reach the debate about limit and rate of variation, the proposal raises questions about the interpretation of graphs, tables, equations and numerical calculations, which are not the main scope of the work, but which are important for the process of construction of the proposed concepts , And the analysis of the data points interesting results. The data of the research is analyzed in light of the theory of the Duval Semiotic Registers. We can point out, at the end of the research, that the students advanced in understanding the concepts addressed in the situations presented and analyzed.
Barnuud, Nyamdorj Namjildorj. "Determining climate change impacts on viticulture in Western Australia". Thesis, Curtin University, 2012. http://hdl.handle.net/20.500.11937/1677.
Texto completo da fonteBorrelli, William. "L'équation de Dirac en physique du solide et en optique non-lineaire". Thesis, Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLED021/document.
Texto completo da fonteRecently, new two-dimensional materials possessing unique properties have been discovered, the most famous being the graphene. In this materials, electrons at the Fermi level behave as massless particles and can be described by the massless Dirac equation. This phenomenon is quite general, and it is a common features of "honeycomb" periodic structures. Moreover, taking into account interaction leads to non-linear Dirac equations, which also appear in the description of light propagation in particular waveguides. The aim of the thesis is to study existence and stability of stationary solutions for those equations with both sub-critical and critical nonlinearities, and to show that they are limit of stationary solutions to the Schroedinger equation with honeycomb potential, for a suitable choice of parameters. This amounts to solving the Euler-Lagrange equation for strongly indefinite energy functionals, involving the Dirac operator. We will deal with critical nonlinearities, which are still poorly understood, and appear naturally in non-linear optics. This results may have an impact on the understanding some solid state or nonlinear optics systems
Chagas, Rebeca Meirelles das. "Estatística para alunos do 6º ano do ensino fundamental: um estudo dos conceitos mobilizados na resolução de problemas". Pontifícia Universidade Católica de São Paulo, 2010. https://tede2.pucsp.br/handle/handle/11444.
Texto completo da fonteSecretaria da Educação do Estado de São Paulo
This study aims to identify the perception of variability and the level of reasoning about this peculiarity, with students of the sixth year at basic education at a state school in Cotia. We discussed what are the concepts and procedures deployed when they resolve issues that involve reading, interpretation and construction of graphs. In particular, diagnose which operative invariants related to the notion of variability that these students mobilized in these activities. As theoretical references, we consider the levels of understanding graphical mobilized by students who are solving problems in statistical context. We also considered the theory of Conceptual Fields seeking to identify the operational invariants by observing the students in situations of problem solving. We performed a qualitative research, with application of a diagnostic instrument, with voluntary participation by two pairs of students. The results pointed to the difficulties of students in reading, interpreting and constructing graphs in specific situations, such as graphs with non-unit scales and null often. For calculating the range, the results showed a stable procedure, especially on the part of one of the pairs studied, in other words, a possible operational invariant, the confusion between the variable frequency and the variable
O presente trabalho tem como objetivo identificar a percepção da variabilidade e o nível de raciocínio sobre essa característica, junto a alunos do sexto ano do Ensino Fundamental de uma escola pública estadual de Cotia. Discutimos quais são os conceitos e procedimentos mobilizados quando estes resolvem questões que envolvem leitura, interpretação e construção de gráficos. Particularmente, diagnosticar quais invariantes operatórios relacionados à noção de variabilidade que estes alunos mobilizaram nessas atividades. Como referências teóricas, consideramos os níveis de compreensão gráfica mobilizados pelos alunos em situação de resolução de problemas em contexto estatístico. Consideramos também a teoria dos Campos Conceituais, buscando identificar os invariantes operatórios por meio da observação dos alunos em situações de resolução de problemas. Foi realizada uma pesquisa qualitativa, com aplicação de um instrumento diagnóstico, com participação voluntária de duas duplas de alunas. Os resultados apontaram para as dificuldades dos alunos na leitura, interpretação e construção de gráficos em situações específicas, como gráficos com escalas não unitárias e o com freqüência nula. Quanto ao cálculo da amplitude, os resultados mostraram um procedimento estável, por parte principalmente de uma das duplas pesquisadas, ou seja, um possível invariante operatório, a confusão entre freqüência da variável e a variável
Cheng, Sibo. "Error covariance specification and localization in data assimilation with industrial application Background error covariance iterative updating with invariant observation measures for data assimilation A graph clustering approach to localization for adaptive covariance tuning in data assimilation based on state-observation mapping Error covariance tuning in variational data assimilation: application to an operating hydrological model". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPAST067.
Texto completo da fonteData assimilation techniques are widely applied in industrial problems of field reconstruction or parameter identification. The error covariance matrices, especially the background matrix in data assimilation are often difficult to specify. In this thesis, we are interested in the specification and localization of covariance matrices in multivariate and multidimensional systems in an industrial context. We propose to improve the covariance specification by iterative processes. Hence, we developed two new iterative methods for background matrix recognition. The power of these methods is demonstrated numerically in twin experiments with independent errors or relative to true states. We then propose a new concept of localization and applied it for error covariance tuning. Instead of relying on spatial distance, this localization is established purely on links between state variables and observations. Finally, we apply these new approaches, together with other classical methods for comparison, to a multivariate hydrological model. Variational assimilation is implemented to correct the observed precipitation in order to obtain a better river flow forecast
Beauchet, Sandra. "Evaluation multicritère d'itinéraires techniques viticoles associant l'évaluation environnementale par Analyse du Cycle de Vie avec l'évaluation de la qualité du raisin. : Contribution au choix des pratiques pour une amélioration des itinéraires techniques viticoles". Electronic Thesis or Diss., Angers, 2016. http://www.theses.fr/2016ANGE0078.
Texto completo da fonteGrape production from PDO wines (Protected Designation of Origin) is subjected to tender specifications, imposing requirements in terms of performance, as well as practices and products quality. In addition to these requirements, the winemaker must now make its viticultural technical management routes evolve, to improve its environmental performances. But, defining actions guidelines for the improvement of viticultural practices based on environmental assessments and grape qualityis very complex, since each one of these assessments provide a significant number of indicators. The aim of the thesis is to construct an evaluation method that takes into consideration both evaluating the environmental performance of viticultural technical management routes with grape quality and assisting the winemaker and advisor to identify practices to ensure the best compromise between "environmental performance" and " product quality". This method allows to analyze a technical management route as well as to compare it to others. This method was developed and tested on five technical management routes with differentiated practices, on the Chenin Blanc grape variety in the middle Loire Valley, for two years with contrasted climates.The study helped (i) analyzing the Life Cycle Assessment (LCA) results specifically for viticulture, (ii) showing the importance of interannual variability in the results of environmental assessment by LCA. The work also led to the development of a model to explain the grapes quality linked with viticultural practices, and soil and climate factors, to study the potential impact of a practice change, on the grape quality evaluation. The CONTRA-QUALENVIC multi-criteria method construction for viticulture is the main outcome of this study, and includes (i) the construction of decision rules and mathematical functions to meet them, and (ii) experts’ meetings to characterize the criteria to aggregate and weight. The CONTRA-QUALENVIC method has been tested by comparing it to other methods.To conclude, the CONTRA-QUALENVIC method is an effective method for decision support as part of a continuous improvement of viticultural practices towards a better respect of the environment, while maintaining the grape quality
Belhadj, Djedjiga. "Multi-GAT semi-supervisé pour l’extraction d’informations et son adaptation au chiffrement homomorphe". Electronic Thesis or Diss., Université de Lorraine, 2024. http://www.theses.fr/2024LORR0023.
Texto completo da fonteThis thesis is being carried out as part of the BPI DeepTech project, in collaboration with the company Fair&Smart, primarily looking after the protection of personal data in accordance with the General Data Protection Regulation (RGPD). In this context, we have proposed a deep neural model for extracting information in semi-structured administrative documents (SSDs). Due to the lack of public training datasets, we have proposed an artificial generator of SSDs that can generate several classes of documents with a wide variation in content and layout. Documents are generated using random variables to manage content and layout, while respecting constraints aimed at ensuring their similarity to real documents. Metrics were introduced to evaluate the content and layout diversity of the generated SSDs. The results of the evaluation have shown that the generated datasets for three SSD types (payslips, receipts and invoices) present a high diversity level, thus avoiding overfitting when training the information extraction systems. Based on the specific format of SSDs, consisting specifically of word pairs (keywords-information) located in spatially close neighborhoods, the document is modeled as a graph where nodes represent words and edges, neighborhood connections. The graph is fed into a multi-layer graph attention network (Multi-GAT). The latter applies the multi-head attention mechanism to learn the importance of each word's neighbors in order to better classify it. A first version of this model was used in supervised mode and obtained an F1 score of 96% on two generated invoice and payslip datasets, and 89% on a real receipt dataset (SROIE). We then enriched the multi-GAT with multimodal embedding of word-level information (textual, visual and positional), and combined it with a variational graph auto-encoder (VGAE). This model operates in semi-supervised mode, being able to learn on both labeled and unlabeled data simultaneously. To further optimize the graph node classification, we have proposed a semi-VGAE whose encoder shares its first layers with the multi-GAT classifier. This is also reinforced by the proposal of a VGAE loss function managed by the classification loss. Using a small unlabeled dataset, we were able to improve the F1 score obtained on a generated invoice dataset by over 3%. Intended to operate in a protected environment, we have adapted the architecture of the model to suit its homomorphic encryption. We studied a method of dimensionality reduction of the Multi-GAT model. We then proposed a polynomial approximation approach for the non-linear functions in the model. To reduce the dimensionality of the model, we proposed a multimodal feature fusion method that requires few additional parameters and reduces the dimensions of the model while improving its performance. For the encryption adaptation, we studied low-degree polynomial approximations of nonlinear functions, using knowledge distillation and fine-tuning techniques to better adapt the model to the new approximations. We were able to minimize the approximation loss by around 3% on two invoice datasets as well as one payslip dataset and by 5% on SROIE
"Variation of cycles in projective spaces". 2007. http://library.cuhk.edu.hk/record=b5893221.
Texto completo da fonteThesis (M.Phil.)--Chinese University of Hong Kong, 2007.
Includes bibliographical references (leaves 51-52).
Abstracts in English and Chinese.
Chapter 1 --- In search of minimal cycles --- p.9
Chapter 1.1 --- What do we mean by cycles? --- p.9
Chapter 1.2 --- Integral currents --- p.10
Chapter 1.3 --- Calibration theory --- p.13
Chapter 2 --- Motivation from the Hodge Conjecture --- p.17
Chapter 2.1 --- Hodge theory on Riemannian manifolds --- p.17
Chapter 2.2 --- Hodge decomposition in Kahler manifolds --- p.19
Chapter 2.3 --- The Hodge conjecture --- p.22
Chapter 3 --- Variation of cycles in symmetric orbit --- p.26
Chapter 3.1 --- Variational formulae --- p.26
Chapter 3.2 --- Stability of cycles in Sm and CPn --- p.29
Chapter 3.3 --- Symmetric orbit in Euclidean space --- p.31
Chapter 3.4 --- Projective spaces in simple Jordan algebra --- p.39
Chapter 3.4.1 --- Introduction to simple Jordan algebra --- p.39
Chapter 3.4.2 --- Projective spaces as symmetric orbits --- p.41
Chapter 3.4.3 --- Computation of second fundamental form --- p.43
Chapter 3.4.4 --- The main theorem --- p.45
Chapter 3.5 --- Future directions --- p.49
Bibliography --- p.51
Roberson, David E. "Variations on a Theme: Graph Homomorphisms". Thesis, 2013. http://hdl.handle.net/10012/7814.
Texto completo da fonteFerreira, Vanessa Cristina Monteiro. "Grape berry color variation: genomic and metabolomic analysis". Doctoral thesis, 2018. http://hdl.handle.net/10348/9146.
Texto completo da fonteGrapevine (Vitis vinifera L.) is one of the oldest perennial domesticated fruit crops in the world and has been widely cultivated and appreciated both for its fruit and wine. During the domestication process of the wild Vitis vinifera subsp. sylvestris to Vitis vinifera subsp. sativa, a complex and long-term evolutionary process led to dramatic changes on grape biology. Since early, vine growers selected the grapevine phenotypes capable of ensuring a greater and regular fruit production and quality, maintaining them through vegetative propagation, thus multiplying highly desirable genotypes. However, natural crossings between newly introduced cultivars and the local germplasm also occurred, alongside with the emergence of somatic events. One of the major contributors for the existing diversity in cultivated grapevine has been the appearance of somatic mutations that affect berry skin color leading to various phenotypes. Indeed, this feature has been used as basis for selection on breeding programs due to its influence on vine growers, winemakers and consumers, representing an important economic factor on this crop. Grapes are not obviously only red or white, instead they provide a huge assortment of colors ranging from whitish, yellow, green, to pink, grey, and to darker red, purple and black berries. This broad range of color cannot be explained by the simple presence of a specific group of molecules, thus, the present study intended to deepen the current knowledge about how grape berry skin color variation is affected by the synthesis of phenolic compounds and their underlying genetic factors. Primarily, the identification of grape berry skin color mutants was performed by genotyping a germplasm set of twenty-five grapevine accessions with twelve microsatellite loci. Among the eleven groups of putative berry skin color mutants genotyped, nine accessions, which were grouped in four different families, were identified as true color mutants, including related black, grey or red and white-skinned variants derived from a single variety. The phenolic profile of the confirmed berry skin color mutants revealed that they could be distinguished according to their non-colored compounds and anthocyanins composition. Moreover, this work benefits from the complementary use of molecular and chemical approaches for the correct identification of the berry skin color mutants studied. The change of berry skin color, from green to white/yellow in non-colored cultivars or from green to pink-red/blue-black in colored cultivars due to anthocyanin synthesis and accumulation occurs during the onset of ripening (veraison). Based on these facts, a first attempt to characterize these changes by means of an integrative approach combining colorimetric (CIELab measurement), metabolic (phenolic profile by HPLC-DAD) and genotypic (allelic composition of MYBA1 and MYBA2 genes) data was performed. This study was focused on the changes that occur during berry development, to improve the knowledge regarding grape berry skin color diversity using somatic variants for berry skin color. Overall, the process of anthocyanin biosynthesis/ accumulation showed a correlation with the colorimetric parameters analysed. Despite the berry skin color variability observed among the somatic variants analyzed was not fully explained by the berry color locus genotype, the phenolic profiles allowed to infer about specific interferences, namely some possible dysfunctions at different levels of the biosynthetic pathway, which could be behind the color variation observed. Additionally, a case study focused on an extremely skin-pigmented Portuguese cultivar (cv. ‘Vinhão’) was conducted throughout berry development, providing the first insights into the genetic and transcriptomic background that may be responsible for the skin color properties of this cultivar. Several types of mutations have been identified at the berry color locus as being responsible for color reversions in grapevine. Through a layer-specific approach, the molecular mechanisms responsible for berry skin color reversion were determined on a subset of somatic variants for berry skin color never investigated before, by the genetic characterization of the berry color locus and its surrounding genomic region. In addition to the observation and description of the most well-known models and mechanisms behind berry skin color reversions, a novel mechanism for the genetic make-up of less-pigmented variants evolving from an unpigmented ancestor was also proposed, in which color gain seems to result from the recovery of the functional G allele on MYBA2. Moreover, it was observed that the mutational events responsible for color gain/ recovery are less understood and different from those described for color loss. On this way, a case study of a white-to-red berry skin color reversion was also performed, in order to better understand its transcriptomic and metabolic consequences in grapevine, specifically in the cv. ‘Moscatel Galego’. The results obtained showed that the coloration of the red-skinned variant was recovered from the white-skinned phenotype of cv. ‘Moscatel Galego Branco’ by the partial activation of the berry color locus. The red-skinned coloration in cv. ‘Moscatel Galego Roxo’ was also associated with the reduced activity of the flavonoid trihydroxylated sub-branch and decreased anthocyanins methylation/acylation.
A videira (Vitis vinifera L.) é uma das mais antigas culturas perenes domesticadas no mundo e tem sido extensamente cultivada e apreciada tanto pelos seus frutos como pelo vinho. Ao longo do processo de domesticação de Vitis vinifera subsp. sylvestris para Vitis vinifera subsp. sativa, um processo evolutivo complexo e de longa duração levou a alterações dramáticas na biologia da uva. Desde cedo, os vitivinicultores selecionaram os fenótipos de videira capazes de assegurar uma maior e mais regular produção e qualidade do fruto, mantendo-os através de propagação vegetativa, multiplicando assim, genótipos altamente desejáveis. No entanto, também ocorreram cruzamentos naturais entre as novas cultivares introduzidas e o germoplama local, juntamente com o aparecimento de eventos somáticos. Uma das maiores contribuições para a diversidade existente na videira cultivada foi o aparecimento de mutações somáticas que afetam a cor do bago levando a vários fenótipos. De facto, esta característica tem sido usada como base de seleção em programas de melhoramento devido à sua influência sobre os vitivinicultores, enólogos e consumidores, representando um importante fator económico nesta cultura. As uvas não são obviamente só tintas ou brancas, em vez disso apresentam uma enorme seleção de cores variando desde uvas esbranquiçadas, amarelas, verdes, a rosadas, rosa-pálido, e até vermelhas mais escuras, roxas e pretas. Este grande intervalo de cor não pode ser explicado pela simples presença de um determinado grupo de moléculas, assim, o presente estudo destinou-se a aprofundar o conhecimento atual sobre como a variação da cor do bago é afetada pela síntese de compostos fenólicos e os seus fatores genéticos subjacentes. Primeiramente, foi efetuada a identificação de mutantes para a cor do bago num conjunto de germoplasma contendo vinte e cinco acessos de videira através da genotipagem com doze loci de microssatélites. Entre os onze grupos de putativos mutantes para a cor do bago genotipados, nove acessos, agrupados em quatro famílias diferentes, foram identificados como verdadeiros mutantes para a cor, incluindo variantes com película de cor tinta, roxa ou rosada e branca derivados de uma única variedade. O perfil fenólico dos mutantes para a cor do bago confirmados revelou que estes podem ser distinguidos de acordo com a sua composição em compostos não-corados e antocianinas. Além disso, este trabalho beneficiou do uso complementar de técnicas moleculares e químicas para a correta identificação dos mutantes para a cor do bago estudados. A alteração da cor do bago, de verde para branco/amarelo em cultivares não-corados ou de verde para rosa-avermelhado/preto-azulado em cultivares corados devido à síntese e acumulação de antocianinas ocorre no início do amadurecimento (pintor). Com base nestes factos, foi realizada uma primeira tentativa de caracterizar estas mudanças recorrendo a uma abordagem integrada combinando dados colorimétricos (medição CIELab), metabólicos (perfil fenólico através de HPLC-DAD) e genotípicos (composição alélica dos genes MYBA1 e MYBA2). Este estudo focou-se nas alterações ocorridas durante o desenvolvimento do bago, de forma a melhorar o conhecimento acerca da diversidade da cor do bago em videira utilizando variantes somáticos para a cor do bago. No geral, o processo de biossíntese/ acumulação de antocianinas demonstrou uma correlação com os parâmetros colorimétricos analisados. Apesar da variabilidade da cor do bago observada entre os variantes somáticos analisados não ser totalmente explicada pelo genótipo do locus da cor do bago, os perfis fenólicos permitiram inferir sobre interferências específicas, nomeadamente sobre possíveis disfunções a diversos níveis da via biossintética, que poderão estar por detrás da variação de cor observada. Adicionalmente, um estudo de caso focado num cultivar Português extremamente pigmentado (cv. ‘Vinhão’) foi conduzido durante o desenvolvimento do bago, fornecendo as primeiras descobertas sobre o fundo genético e transcritómico que poderá ser responsável pelas propriedades colorimétricas deste cultivar. Vários tipos de mutações têm sido identificados no locus da cor do bago como sendo responsáveis por reversões de cor em videira. Através de uma abordagem específica em camadas, os mecanismos moleculares responsáveis por reversões de cor foram determinados num conjunto de variantes somáticos para a cor da película do bago, nunca estudados anteriormente, através da caracterização genética do locus da cor do bago e da região genómica adjacente. Além da observação e descrição dos modelos e mecanismos responsáveis pela reversão de cor mais conhecidos, foi também proposto um novo mecanismo responsável pela composição genética de variantes pouco pigmentados descendentes de um ancestral não pigmentado, no qual o ganho de cor parece resultar da recuperação do alelo funcional G no gene MYBA2. Além disso, foi observado que os eventos mutacionais responsáveis pelo ganho/ recuperação de cor são menos compreendidos e diferentes dos descritos para a perda de cor. Desta forma, foi realizado o estudo de um caso de reversão de cor, de branco para rosado, de forma a melhor compreender as suas consequências a nível transcritómico e metabólico em videira, especificamente no cv. ‘Moscatel Galego’. Os resultados obtidos demonstraram que a coloração do variante roxo foi recuperada a partir do fenótipo branco do cv. ‘Moscatel Galego Branco’ através da ativação parcial do locus da cor do bago. A coloração roxa do cv. ‘Moscatel Galego Roxo’ foi também associada à reduzida atividade da sub-via dos flavonoides tri-hidroxilados e à diminuição da metilação/ acilação das antocianinas
潘俊杰. "Path Partition and Its Variations in Graphs". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/6rxf2k.
Texto completo da fonteTang, Jianmin. "Variations of classical extremal graph theoretical problems: Moore bound and connectivity". Thesis, 2009. http://hdl.handle.net/1959.13/38550.
Texto completo da fonteInterconnection networks form an important research area which has received much attention, both in theoretical research and in practice. Design of interconnection networks is much concerned with the topology of networks. The topology of a network is usually studied in terms of extremal graph theory. Consequently, from the extremal graph theory point of view, designing the topology of a network involves various extremal graph problems. One of these problems is the well-known fundamental problem called the degree/diameter problem, which is to determine the largest (in terms of the number of vertices) graphs or digraphs of given maximum degree and given diameter. General upper bounds, called Moore bounds, exist for the largest possible order of such graphs and digraphs of given maximum degree ∆ (respectively, out-degree d) and diameter D. However, quite a number of open problems regarding the degree/diameter problem do still exist. Some of these problems, such as constructing a Moore graph of degree ∆ = 57 and diameter D = 2, have been open for over 50 years. Another extremal graph problem regarding the design of the topology of a network is called the construction of EX graphs, which is to obtain graphs of the largest size (in terms of the number of edges), given order and forbidden cycle lengths. In this thesis, we obtain large graphs whose sizes either improve the lower bound of the size of EX graphs, or even reach the optimal value. We deal with designing the topology of a network, but we are also interested in the issue of fault tolerance of interconnection networks. This leads us to another extremal graph problem, that is, connectivity. In this thesis, we provide an overview of the current state of research in connectivity of graphs and digraphs. We also present our contributions to the connectivity of general regular graphs with small diameter, and the connectivity of EX graphs.
Tang, Jianmin. "Variations of classical extremal graph theoretical problems: Moore bound and connectivity". 2009. http://hdl.handle.net/1959.13/38550.
Texto completo da fonteInterconnection networks form an important research area which has received much attention, both in theoretical research and in practice. Design of interconnection networks is much concerned with the topology of networks. The topology of a network is usually studied in terms of extremal graph theory. Consequently, from the extremal graph theory point of view, designing the topology of a network involves various extremal graph problems. One of these problems is the well-known fundamental problem called the degree/diameter problem, which is to determine the largest (in terms of the number of vertices) graphs or digraphs of given maximum degree and given diameter. General upper bounds, called Moore bounds, exist for the largest possible order of such graphs and digraphs of given maximum degree ∆ (respectively, out-degree d) and diameter D. However, quite a number of open problems regarding the degree/diameter problem do still exist. Some of these problems, such as constructing a Moore graph of degree ∆ = 57 and diameter D = 2, have been open for over 50 years. Another extremal graph problem regarding the design of the topology of a network is called the construction of EX graphs, which is to obtain graphs of the largest size (in terms of the number of edges), given order and forbidden cycle lengths. In this thesis, we obtain large graphs whose sizes either improve the lower bound of the size of EX graphs, or even reach the optimal value. We deal with designing the topology of a network, but we are also interested in the issue of fault tolerance of interconnection networks. This leads us to another extremal graph problem, that is, connectivity. In this thesis, we provide an overview of the current state of research in connectivity of graphs and digraphs. We also present our contributions to the connectivity of general regular graphs with small diameter, and the connectivity of EX graphs.
Harris, Laura Marie. "Aspects of functional variations of domination in graphs". Thesis, 2003. http://hdl.handle.net/10413/7384.
Texto completo da fonteThesis (Ph.D.)-University of Natal, Pietermaritzburg, 2003.
(9790343), Kishor Dahal. "Insights into seasonal yield variation in subtropical table grape production". Thesis, 2019. https://figshare.com/articles/thesis/Insights_into_seasonal_yield_variation_in_subtropical_table_grape_production/13468785.
Texto completo da fonteVillano, Clizia. "Discovery and genotyping of DNA sequence variations in grape". Tesi di dottorato, 2015. http://www.fedoa.unina.it/10298/1/Villano_Clizia_27.pdf.
Texto completo da fonteKrishnamoorthy, Raju. "Dynamics, Graph Theory, and Barsotti-Tate Groups: Variations on a Theme of Mochizuki". Thesis, 2016. https://doi.org/10.7916/D88K792N.
Texto completo da fonte