Search results for "complex"

showing 10 items of 5889 documents

Improving diagnostic accuracy of MDCT coronary angiography in patients with mild heart rhythm irregularities using ECG editing

2006

OBJECTIVE. The objective of our study was to compare diagnostic accuracy of MDCT coronary angiography in a population of patients with mild heart rhythm irregularities before and after editing the ECG. SUBJECTS AND METHODS. Thirty-eight patients who underwent MDCT coronary angiography and conventional coronary angiography were enrolled in the study. The inclusion criterion was the presence of mild heart rhythm irregularities (i.e., premature beats; atrial fibrillation; mistriggering; or low heart rate, defined as 40 beats per minute or less) during the scan. All patients underwent MDCT with the following parameters: 16 detectors; collimation, 0.75 mm; gantry rotation time, 375 msec; 120 kV;…

Coronary angiographyMalemedicine.medical_specialtyCardiac Complexes PrematurePopulationContrast MediaDiagnostic accuracyCoronary AngiographySensitivity and SpecificityElectrocardiographyPredictive Value of TestsInternal medicineHeart rateAtrial FibrillationmedicineBradycardiaHumansRadiology Nuclear Medicine and imagingcardiovascular diseasesProspective Studieseducationeducation.field_of_studymedicine.diagnostic_testCardiac cyclebusiness.industryAtrial fibrillationGeneral Medicinearteriography coronary angiography ECG editing heart rhythm MDCT angiographyMiddle Agedmedicine.diseaseIopamidolHeart Rhythmcardiovascular systemCardiologyFemaleRadiologybusinessTomography X-Ray ComputedElectrocardiography
researchProduct

New delay-dependent stability conditions for time-varying delay systems

2013

Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/360924 Open Access This paper addresses the delay-dependent stability for systems with time-varying delay. First, by taking multi-integral terms into consideration, new Lyapunov-Krasovskii functional is defined. Second, in order to reduce the computational complexity of the main results, reciprocally convex approach and some special transformations are introduced, and new delay-dependent stability criteria are proposed, which are less conservative and have less decision variables than some previous results. Finally, two well-known example…

CorrectnessArticle SubjectComputational complexity theoryComputer scienceGeneral Mathematicslcsh:MathematicsGeneral EngineeringStability (learning theory)lcsh:QA1-939Delay dependentStability conditionsControl theorylcsh:TA1-2040VDP::Matematikk og Naturvitenskap: 400::Matematikk: 410::Analyse: 411lcsh:Engineering (General). Civil engineering (General)Algorithm
researchProduct

Connectivity Influences on Nonlinear Dynamics in Weakly-Synchronized Networks: Insights from Rössler Systems, Electronic Chaotic Oscillators, Model a…

2019

Natural and engineered networks, such as interconnected neurons, ecological and social networks, coupled oscillators, wireless terminals and power loads, are characterized by an appreciable heterogeneity in the local connectivity around each node. For instance, in both elementary structures such as stars and complex graphs having scale-free topology, a minority of elements are linked to the rest of the network disproportionately strongly. While the effect of the arrangement of structural connections on the emergent synchronization pattern has been studied extensively, considerably less is known about its influence on the temporal dynamics unfolding within each node. Here, we present a compr…

Correlation dimensionCollective behaviornonlinear dynamicGeneral Computer ScienceComputer scienceNetwork topologyTopology01 natural sciencesnetwork topology010305 fluids & plasmasnode degreeRössler systemEntropy (classical thermodynamics)nonlinear dynamicschaotic transition0103 physical sciencesEntropy (information theory)Attractor dimensionGeneral Materials Sciencestructural connectivity010306 general physicsprediction errorstochastic dynamicsGeneral EngineeringSaito oscillatorelectronic chaotic oscillatorComplex networkNonlinear systemneuronal culturestochastic dynamicnodal strengthChaotic oscillatorscomplexityentropysynchronizationEntropy (order and disorder)
researchProduct

On the Evaluation of Images Complexity: A Fuzzy Approach

2006

The inherently multidimensional problem of evaluating the complexity of an image is of a certain relevance in both computer science and cognitive psychology. Computer scientists usually analyze spatial dimensions, to deal with automatic vision problems, such as feature-extraction. Psychologists seem more interested in the temporal dimension of complexity, to explore attentional models. Is it possible, by merging both approaches, to define an more general index of visual complexity? We have defined a fuzzy mathematical model of visual complexity, using a specific entropy function; results obtained by applying this model to pictorial images have a strong correlation with ones from an experime…

CorrelationBinary entropy functionbusiness.industryComputer scienceFuzzy setEntropy (information theory)Artificial intelligencebusinessMachine learningcomputer.software_genreFuzzy logiccomputerVisual complexity
researchProduct

One-Counter Verifiers for Decidable Languages

2013

Condon and Lipton (FOCS 1989) showed that the class of languages having a space-bounded interactive proof system (IPS) is a proper subset of decidable languages, where the verifier is a probabilistic Turing machine. In this paper, we show that if we use architecturally restricted verifiers instead of restricting the working memory, i.e. replacing the working tape(s) with a single counter, we can define some IPS’s for each decidable language. Such verifiers are called two-way probabilistic one-counter automata (2pca’s). Then, we show that by adding a fixed-size quantum memory to a 2pca, called a two-way one-counter automaton with quantum and classical states (2qcca), the protocol can be spac…

Counter machineTheoryofComputation_COMPUTATIONBYABSTRACTDEVICESTheoretical computer scienceQuantum registerComputer scienceProbabilistic Turing machineProbabilistic logicInteractive proof systemComputer Science::Computational ComplexityDecidabilityAutomatonsymbols.namesakesymbolsProtocol (object-oriented programming)
researchProduct

[(Pyridylcarbonyl)pyridyl]triazolopyridines, Useful Ligands for the Construction of Polynuclear Coordination Compounds – Synthesis, Crystal Structure…

2007

A new tetranuclear cubane Cu4O4 complex has been synthesised from assembly of CuII ions and the polydentate ligand (pyridin-2-yl){6-([1,2,3]triazolo[1,5-a]pyridin-3-yl)pyridin-2-yl}methanone. Crystallographic analysis indicates that the Cu4O4 unit has an S4 symmetry. The magnetic properties have been analysed using the H = –2Σi,jJijSiSj spin Hamiltonian. Two distinct coupling constants, 2J1,3 = –37.4 cm–1 and 2J1,2 = –2.6 cm–1, obtained from the fitting of the experimental data have been rationalised on the basis of a density functional study of magnetostructural correlations in cubane complexes containing the Cu4O4 core. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Coupling constantchemistry.chemical_classificationDenticityLigandStereochemistrychemistry.chemical_elementCrystal structureCopperIonCoordination complexInorganic ChemistryCrystallographychemistry.chemical_compoundchemistryCubaneEuropean Journal of Inorganic Chemistry
researchProduct

Modified mode-coupling theory for the collective dynamics of simple liquids

2011

Recently it has been shown that mode-coupling theory, which accounts for the salient features of glassy relaxation near the liquid–glass transition, is also capable of describing the collective excitations of simple liquids away from the glass transition. In order to further improve the agreement between theory and computer simulations on Lennard-Jones argon we modify MCT by taking binary collisions into account. This, in fact, improves the agreement. We also show that multiplying the memory function of the original theory with a reduction factor leads to similar results.

CouplingChemistryFunction (mathematics)Condensed Matter PhysicsCondensed Matter::Disordered Systems and Neural NetworksCondensed Matter::Soft Condensed MatterReduction (complexity)Mode couplingQuasiparticleRelaxation (physics)General Materials ScienceStatistical physicsGlass transitionExcitationJournal of Physics: Condensed Matter
researchProduct

Hsp60 Inhibitors and Modulators

2019

In this chapter, we focus on the 60 KDa Heat Shock Protein (Hsp60) and discuss some of its biological, molecular and pathological features. The structural and mechanistic aspect of the Hsp60 folding cycle will be also presented. We further illustrate how Hsp60 may be involved in many diseases and therefore considered as an effective therapeutic or theranostic target. Finally, the state-of-the-art on the development of Hsp60 and bacterial GroEL inhibitors and modulators of their expression will be illustrated. This is discussed in the light of a negative chaperonotherapy, and the consequent development of inhibitors, as well as positive chaperonotherapy, in the event its excessive activity i…

Cpn60Excessive activityHsp60 inhibitoranimal structuresHeat shock proteinChemistryPyrazolopyrimidinefungiAvrainvillamidechemical and pharmacologic phenomenaComputational biologyMizoribineSettore CHIM/06 - Chimica OrganicaCarboranylphenoxyacetanilideHsp60complex mixturesGroELGroELHspD1Heat shock proteinHSP60AvrainvillamideEpolactaene
researchProduct

Les sites ecclésiaux et monastiques de l’archipel du Kvarner (Croatie), campagne 2018 : Mirine-Fulfinum (Omišalj, île de Krk)

2018

International audience

CroatieAntiquité tardive[SHS.ARCHEO] Humanities and Social Sciences/Archaeology and Prehistory[SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistoryarchéologiecomplexe ecclésialinsularitévillapeigne liturgiqueComputingMilieux_MISCELLANEOUSpressoir à huile
researchProduct

Archipel du Kvarner (Croatie). Prospection-inventaire des sites ecclésiaux et monastiques : campagne 2015

2016

International audience; Le programme de prospection-inventaire initié en 20101 est entré dans une nouvelle phase en 2015 avec le démarrage de la fouille programmée de la grande église du complexe de Martinšćica (île de Cres) du 29 juin au 18 juillet2. Dans le même temps, la poursuite des prospections a été à l’origine de la découverte d’une nouvelle église sur l’îlot de Mali Ćutin. Le troisième volet du programme a porté sur le site de Mirine-Fulfinum (île de Krk), du 19 au 30 octobre, avec la préparation du chantier de fouille dans le secteur dit de « l’église à trois absides ».

Croatiefunéraire[SHS.ARCHEO] Humanities and Social Sciences/Archaeology and Prehistory[SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistoryarchéologiemonastèrecomplexe ecclésialGeneral Medicinearchéologie du bâtiinsularitéAntiquité tardive[ SHS.ARCHEO ] Humanities and Social Sciences/Archaeology and Prehistoryhaut Moyen Âgevilla
researchProduct