Search results for " graph"

showing 10 items of 1277 documents

Cost-driven framework for progressive compression of textured meshes

2019

International audience; Recent advances in digitization of geometry and radiometry generate in routine massive amounts of surface meshes with texture or color attributes. This large amount of data can be compressed using a progressive approach which provides at decoding low complexity levels of details (LoDs) that are continuously refined until retrieving the original model. The goal of such a progressive mesh compression algorithm is to improve the overall quality of the transmission for the user, by optimizing the rate-distortion trade-off. In this paper, we introduce a novel meaningful measure for the cost of a progressive transmission of a textured mesh by observing that the rate-distor…

Texture atlasDecimationadaptive quantizationmultiplexingComputer scienceGeometry compressionComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISIONInversesurface meshes02 engineering and technologyData_CODINGANDINFORMATIONTHEORYtexturesprogressive vs single-rate[INFO.INFO-CG]Computer Science [cs]/Computational Geometry [cs.CG]MultiplexingCCS CONCEPTS • Computing methodologies → Computer graphics020204 information systems0202 electrical engineering electronic engineering information engineering020201 artificial intelligence & image processingPolygon meshQuantization (image processing)AlgorithmDecoding methodsData compressionComputingMethodologies_COMPUTERGRAPHICS
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Rapid and eco-friendly synthesis of graphene oxide-silica nanohybrids

2014

The increasing interest in Graphene oxide (GO) is due to many issues: the presence of both sp2-conjugated atoms and oxygen-containing functional groups provides a strong hydrophilicity and the possibility to further functionalize it with other molecules (i.e. π-π interactions covalent attachment etc.) [1]. Furthermore since the GO is biocompatible and noncytotoxic many studies have been recently focused on the development of GO-based nanodevices for bioimaging DNA detection drug delivery. Due to their low cytotoxicity and large internal surface area silica nanoparticles have been taken into account as promising material for biolabeling and drug loading/delivery. Particular consideration has recently been demonstrated for GO-silica composites because of the potentialities for electrical applications their chemical inertia and stability toward ions exposure. The possibility to combine the extraordinary properties of GO and silica offers several advantages for the realization of nanoprobes for biological applications and of biosensor [12]. The strategy for the fabrication of GO-nanosilica nanohybrids can be schematized as follows: (i) synthesis of GO by oxidizing graphite powder with the method described by Marcano et al. [3] (ii) Preparation of oxygen-loaded silica nanoparticles by thermal treatments in controlled atmosphere in order to induce high NIR emission at 1272 nm from high purity silica nanoparticles. (iii) preparation of GrO-silica nanohybrid films via rapid solvent casting in water. The nanohybrids were tested by XPS FTIR Raman analysis UV photoluminescence analysis TGA Zeta potential measurements electrical tests AFM and SEM. Several nanohybrids were prepared by combining two different typologies of GO and two different samples of silica.
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Underlying Simple Graphs

2019

Summary In this article the notion of the underlying simple graph of a graph (as defined in [8]) is formalized in the Mizar system [5], along with some convenient variants. The property of a graph to be without decorators (as introduced in [7]) is formalized as well to serve as the base of graph enumerations in the future.

Theoretical computer scienceApplied Mathematics020207 software engineering0102 computer and information sciences02 engineering and technology68t9901 natural sciencesComputational Mathematics03b35010201 computation theory & mathematicsSimple (abstract algebra)underlying simple graphQA1-9390202 electrical engineering electronic engineering information engineering05c76Graph operationsgraph operationsMathematicsMathematicsofComputing_DISCRETEMATHEMATICSMathematicsFormalized Mathematics
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Global RDF Vector Space Embeddings

2017

Vector space embeddings have been shown to perform well when using RDF data in data mining and machine learning tasks. Existing approaches, such as RDF2Vec, use local information, i.e., they rely on local sequences generated for nodes in the RDF graph. For word embeddings, global techniques, such as GloVe, have been proposed as an alternative. In this paper, we show how the idea of global embeddings can be transferred to RDF embeddings, and show that the results are competitive with traditional local techniques like RDF2Vec.

Theoretical computer scienceComputer science020204 information systems0202 electrical engineering electronic engineering information engineeringRdf graph020201 artificial intelligence & image processing02 engineering and technologycomputer.file_formatLinked dataRDFcomputerWord (computer architecture)Vector space
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Dictionary-symbolwise flexible parsing

2012

AbstractLinear-time optimal parsing algorithms are rare in the dictionary-based branch of the data compression theory. A recent result is the Flexible Parsing algorithm of Matias and Sahinalp (1999) that works when the dictionary is prefix closed and the encoding of dictionary pointers has a constant cost. We present the Dictionary-Symbolwise Flexible Parsing algorithm that is optimal for prefix-closed dictionaries and any symbolwise compressor under some natural hypothesis. In the case of LZ78-like algorithms with variable costs and any, linear as usual, symbolwise compressor we show how to implement our parsing algorithm in linear time. In the case of LZ77-like dictionaries and any symbol…

Theoretical computer scienceComputer science[INFO.INFO-DS]Computer Science [cs]/Data Structures and Algorithms [cs.DS][INFO.INFO-DS] Computer Science [cs]/Data Structures and Algorithms [cs.DS]Data_CODINGANDINFORMATIONTHEORY0102 computer and information sciences02 engineering and technologycomputer.software_genre01 natural sciencesDirected acyclic graphTheoretical Computer ScienceConstant (computer programming)020204 information systemsEncoding (memory)Optimal parsing0202 electrical engineering electronic engineering information engineeringDiscrete Mathematics and CombinatoricsStringologySymbolwise text compressionTime complexityLossless compressionParsingSettore INF/01 - InformaticaDictionary-based compressionOptimal Parsing Lossless Data Compression DAGDirected acyclic graphPrefixComputational Theory and MathematicsText compression010201 computation theory & mathematicsAlgorithmcomputerBottom-up parsingData compressionJournal of Discrete Algorithms
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The heterogeneity of inter-domain Internet application flows: entropic analysis and flow graph modelling

2013

The growing popularity of the Internet has triggered the proliferation of various applications, which possess diverse communication patterns and user behaviour. In this paper, the heterogeneous characteristics of Internet applications and traffic are investigated from a complex network and entropic perspective. On the basis of real-life flow data collected from a public network provided by an Internet service provider, flow graphs are constructed for five types of applications as follows: Web, P2P Download, P2P Stream, Video Stream and Instant Messaging. Three types of entropy measures are introduced to the flow graphs, and the heterogeneity of applications within a 24-h period is analysed …

Theoretical computer scienceComputer sciencebusiness.industryInter-domainTraffic identificationComplex networkcomputer.software_genreDegree distributionInternet service providerEntropy (information theory)Control flow graphThe InternetData miningElectrical and Electronic EngineeringbusinesscomputerTransactions on Emerging Telecommunications Technologies
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Statistically validated networks in bipartite complex systems.

2011

Many complex systems present an intrinsic bipartite nature and are often described and modeled in terms of networks [1-5]. Examples include movies and actors [1, 2, 4], authors and scientific papers [6-9], email accounts and emails [10], plants and animals that pollinate them [11, 12]. Bipartite networks are often very heterogeneous in the number of relationships that the elements of one set establish with the elements of the other set. When one constructs a projected network with nodes from only one set, the system heterogeneity makes it very difficult to identify preferential links between the elements. Here we introduce an unsupervised method to statistically validate each link of the pr…

Theoretical computer scienceComputer sciencelcsh:MedicineNetwork theorySocial and Behavioral SciencesBioinformaticsQuantitative Biology - Quantitative MethodsSociologyProtein Interaction Mappinglcsh:ScienceQuantitative Methods (q-bio.QM)MultidisciplinarySystems BiologyApplied MathematicsPhysicsStatisticsComplex SystemsGenomicsLink (geometry)Social NetworksSpecialization (logic)Interdisciplinary PhysicsBipartite graphProbability distributionResearch ArticleNetwork analysisPhysics - Physics and SocietyComplex systemFOS: Physical sciencesPhysics and Society (physics.soc-ph)Type (model theory)BiologyModels BiologicalNetwork theory Statistical PhysicsStatistical MechanicsSet (abstract data type)Statistical MethodsBiologyStructure (mathematical logic)Statistical Physicslcsh:RComputational BiologyModels TheoreticalComparative GenomicsSettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)FOS: Biological sciencesNetwork theorylcsh:QNull hypothesisMathematicsPLoS ONE
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Distributed Consensus on Boolean Information

2009

Abstract In this paper we study the convergence towards consensus on information in a distributed system of agents communicating over a network. The particularity of this study is that the information on which the consensus is seeked is not represented by real numbers, rather by logical values or sets. Whereas the problems of allowing a network of agents to reach a consensus on logical functions of input events, and that of agreeing on set–valued information, have been separately addressed in previous work, in this paper we show that these problems can indeed be attacked in a unified way in the framework of Boolean distributed information systems. Based on a notion of contractivity for Bool…

Theoretical computer scienceDynamical systems theoryAnd-inverter graphConsensus theoremGeneral Medicinedistributed estimationUniform consensusBoolean networkSettore ING-INF/04 - AutomaticaConsensusInformation systemBoolean dynamics systemBoolean consensus algorithmStandard Boolean modelMathematics
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On the problem of visualizing point distributions in high dimensional spaces

1995

Abstract Exploring dynamical systems with the aid of computer graphics requires that the relevant structures can be seen and be noticed. This poses special problems if the system is multidimensional, and it has to be decided which kind of projection serves the purpose. I propose using the mathematical frame of categories and functors to describe the process of visualization. This allows detecting and analyzing possible sources of misinterpretation in a formal way. The distribution of distances of embedded electroencephalographic data from a fixed reference point is used as an example for discussing some aspects of the visualization process. The multidimensional p-norms are an example of a p…

Theoretical computer scienceDynamical systems theoryFrame (networking)General EngineeringStructure (category theory)Computer Graphics and Computer-Aided DesignVisualizationHuman-Computer InteractionComputer graphicsProjection (mathematics)GraphicsDynamical system (definition)AlgorithmMathematicsComputers & Graphics
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Tabu search for the dynamic Bipartite Drawing Problem

2018

Abstract Drawings of graphs have many applications and they are nowadays well-established tools in computer science in general, and optimization in particular. Project scheduling is one of the many areas in which representation of graphs constitutes an important instrument. The experience shows that the main quality desired for drawings of graphs is readability, and crossing reduction is a fundamental aesthetic criterion to achieve it. Incremental or dynamic graph drawing is an emerging topic in this context, where we seek to preserve the layout of a graph over successive drawings. In this paper, we target the edge crossing reduction in the context of incremental graph drawing. Specifically…

Theoretical computer scienceGeneral Computer ScienceComputer sciencebusiness.industryHeuristic020207 software engineering02 engineering and technologyManagement Science and Operations ResearchMachine learningcomputer.software_genreGraphTabu searchGraph drawingModeling and SimulationClique-width0202 electrical engineering electronic engineering information engineeringBipartite graph020201 artificial intelligence & image processingForce-directed graph drawingArtificial intelligencebusinesscomputerGraph productComputers & Operations Research
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