Search results for "Crete"

showing 10 items of 2495 documents

Automorphisms of hyperelliptic GAG-codes

2009

Abstract We determine the n –automorphism group of generalized algebraic-geometry codes associated with rational, elliptic and hyperelliptic function fields. Such group is, up to isomorphism, a subgroup of the automorphism group of the underlying function field.

Abelian varietyDiscrete mathematicsautomorphismsGroup (mathematics)Applied Mathematicsgeneralized algebraic geometry codes.Outer automorphism groupReductive groupAutomorphismTheoretical Computer ScienceCombinatoricsMathematics::Group Theorygeometric Goppa codeAlgebraic groupDiscrete Mathematics and Combinatoricsalgebraic function fieldsSettore MAT/03 - GeometriaIsomorphismfinite fieldsGeometric Goppa codesfinite fieldalgebraic function fieldHyperelliptic curvegeneralized algebraic-geometry codesMathematicsDiscrete Mathematics
researchProduct

Instantaneous transfer entropy for the study of cardio-respiratory dynamics

2015

Measures of transfer entropy have been proposed to quantify the directional coupling and strength between two complex physiological variables. Particular attention has been given to nonlinear interactions within cardiovascular and respiratory dynamics as influenced by the autonomic nervous system. However, standard transfer entropy estimates have shown major limitations in dealing with issues concerning stochastic system modeling, limited observations in time, and the assumption of stationarity of the considered physiological variables. Moreover, standard estimates are unable to track time-varying changes in nonlinear coupling with high resolution in time. Here, we propose a novel definitio…

AdultMaleInformation transferComputer scienceEntropyPostureBiomedical EngineeringProbability density functionHealth InformaticsMaximum entropy spectral estimationNonlinear DynamicEntropy (classical thermodynamics)ElectrocardiographyTheoreticalRespiratory RateControl theoryModelsHeart RateTilt-Table TestEntropy (information theory)Humans1707; Signal Processing; Biomedical Engineering; Health InformaticsStatistical physicsEntropy (energy dispersal)Entropy (arrow of time)1707Likelihood FunctionsEntropy (statistical thermodynamics)Models TheoreticalLikelihood FunctionNonlinear systemDiscrete time and continuous timeNonlinear DynamicsSignal ProcessingSettore ING-INF/06 - Bioingegneria Elettronica E InformaticaTransfer entropyFemaleAdult; Electrocardiography; Entropy; Female; Heart Rate; Humans; Likelihood Functions; Male; Models Theoretical; Nonlinear Dynamics; Posture; Tilt-Table Test; Respiratory Rate; Signal Processing; Biomedical Engineering; 1707; Health InformaticsEntropy (order and disorder)Human
researchProduct

Instantaneous Transfer Entropy for the Study of Cardiovascular and Cardio-Respiratory Nonstationary Dynamics

2017

Objective: Measures of transfer entropy (TE) quantify the direction and strength of coupling between two complex systems. Standard approaches assume stationarity of the observations, and therefore are unable to track time-varying changes in nonlinear information transfer with high temporal resolution. In this study, we aim to define and validate novel instantaneous measures of TE to provide an improved assessment of complex nonstationary cardiorespiratory interactions. Methods: We here propose a novel instantaneous point-process TE (ipTE) and validate its assessment as applied to cardiovascular and cardiorespiratory dynamics. In particular, heartbeat and respiratory dynamics are characteriz…

AdultMaleInformation transferHistoryHeartbeatDatabases FactualPhysiologyEntropy0206 medical engineeringComplex systemBiomedical EngineeringHeart Rate VariabilityProbability density function02 engineering and technology01 natural sciencesPoint processStatistics NonparametricElectrocardiographyYoung Adult0103 physical sciencesProbability density functionEntropy (information theory)HumansStatistical physicsTransfer Entropy010306 general physicsBiomedical measurementMathematicsbusiness.industryHemodynamicsModels CardiovascularHeart beatSignal Processing Computer-AssistedComplexityBaroreflex020601 biomedical engineeringKolmogorov-Smirnov DistanceRespiratory Sinus ArrhythmiaBaroreflex; Biomedical measurement; Complexity; Entropy; Heart beat; Heart rate variability; Heart Rate Variability; History; Kolmogorov-Smirnov Distance; Physiology; Point Process; Probability density function; Respiratory Sinus Arrhythmia; Transfer Entropy; Biomedical EngineeringDiscrete time and continuous timePoint ProceSettore ING-INF/06 - Bioingegneria Elettronica E InformaticaPoint ProcessTransfer entropyFemaleArtificial intelligencebusiness
researchProduct

A discrete-choice experiment to assess patients’ preferences for osteoarthritis treatment: An ESCEO working group

2020

Objective: To evaluate the preferences of patients with osteoarthritis for treatment.Methods: A discrete-choice experiment was conducted among adult OA patients who were presented with 12 choice sets of two treatment options and asked in each to select the treatment they would prefer. Based on literature reviews, expert consultation, patient survey and expert meeting, treatment options were characterized by seven attributes: improvement in pain, improvement in walking, ability to manage domestic activities, ability to manage social activities, improvement in overall energy and well-being, risk of moderate/severe side effects and impact on disease progression. Random parameters logit model w…

AdultMalemedicine.medical_specialtyDiscrete choice experimentOsteoarthritisOutcomes03 medical and health sciences0302 clinical medicinePHYSICIANSRheumatologySurveys and QuestionnairesOsteoarthritisMedicineHumans030212 general & internal medicineAgedOutcome030203 arthritis & rheumatologyddc:616HIPbusiness.industryDisease progressionDiscrete-choice experimentTreatment optionsPatient PreferencePatient preferencesmedicine.diseaseLatent class modelPreferenceEuropeInstitutional repositoryAnesthesiology and Pain MedicineLogistic ModelsPhysical therapyPatient surveyFemaleKNEEOsteoarthritiHEALTHbusiness
researchProduct

Darstellung von Hyperebenen in verallgemeinerten affinen Räumen durch Moduln

1994

The starting point of this article is a generalized concept of affine space which includes all affine spaces over unitary modules. Our main result is a representation theorem for hyperplanes of affine spaces: Every hyperplane which satisfies a weak richness condition is induced by a module. 1

Affine coordinate systemDiscrete mathematicsAffine geometryPure mathematicsMathematics (miscellaneous)Affine representationComplex spaceHyperplaneApplied MathematicsAffine hullAffine groupAffine spaceMathematicsResults in Mathematics
researchProduct

Affine Kettengeometrien �ber Jordanalgebren

1996

It is shown that an affine chain geometry over a Jordan algebra can be constructed in a nearly classical manner. Conversely, such chain geometries are characterized as systems of rational normal curves having a group of automorphisms with certain properties.

Affine coordinate systemDiscrete mathematicsAffine geometryQuantum affine algebraPure mathematicsAffine representationAffine geometry of curvesAffine hullAffine groupGeometry and TopologyAffine planeMathematicsGeometriae Dedicata
researchProduct

On the algebraic representation of projectively embeddable affine geometries

1995

The main result of this article is an application of [1] and [2] which yields that an at least 2-dimensional affine geometry is module-induced if and only if it is projectively embeddable into an Arguesian projective lattice geometry.

Affine geometryDiscrete mathematicsAffine geometry of curvesAlgebra representationGeometry and TopologyAffine transformationLattice (discrete subgroup)Affine planeMathematicsJournal of Geometry
researchProduct

Green geopolymeric concrete using grits for applications in construction

2018

Abstract This work investigates the production a green geopolymer-based concrete for a sustainable construction material using biomass wastes from a kraft pulp industry: fly ash (as main alumina-silicate source) and grits (as aggregate). Moreover, a simple, reproducible, ambient temperature, and low-cost manufacture is followed. Mix design aims to maximize wastes incorporation and optimize the mechanical performance. Preliminary tests indicate that the used wastes may be successfully employed to produce green geopolymeric concretes with satisfying mechanical performance (up to 18 MPa), according to the European standards. Furthermore, they represent a viable solution to reduce the environme…

Aggregate (composite)Materials scienceWaste management020209 energyMechanical Engineering0211 other engineering and technologiesSettore ICAR/10 - Architettura TecnicaBiomass02 engineering and technologyGritMechanicsCondensed Matter PhysicsGeopolymeric concreteMix designGeopolymerSustainable constructionKraft processBiomass fly-ashMechanics of MaterialsFly ash021105 building & construction0202 electrical engineering electronic engineering information engineeringGeneral Materials ScienceConstructionWaste disposalMaterials Letters
researchProduct

Products of snowflaked Euclidean lines are not minimal for looking down

2017

We show that products of snowflaked Euclidean lines are not minimal for looking down. This question was raised in Fractured fractals and broken dreams, Problem 11.17, by David and Semmes. The proof uses arguments developed by Le Donne, Li and Rajala to prove that the Heisenberg group is not minimal for looking down. By a method of shortcuts, we define a new distance $d$ such that the product of snowflaked Euclidean lines looks down on $(\mathbb R^N,d)$, but not vice versa.

Ahlfors-regularity26B05 (Primary) 28A80 (Secondary)01 natural sciences010104 statistics & probabilityFractalMathematics - Metric GeometryEuclidean geometryClassical Analysis and ODEs (math.CA)FOS: MathematicsHeisenberg groupMathematics::Metric GeometryBPI-spacesbpi-spacessecondary 28a800101 mathematicsbilipschitz piecesMathematicsDiscrete mathematicsQA299.6-433ahlfors-regularityApplied Mathematics010102 general mathematicsprimary 26b05Metric Geometry (math.MG)biLipschitz piecesMathematics - Classical Analysis and ODEsProduct (mathematics)Geometry and TopologyAnalysis
researchProduct

Additivity of affine designs

2020

We show that any affine block design $$\mathcal{D}=(\mathcal{P},\mathcal{B})$$ is a subset of a suitable commutative group $${\mathfrak {G}}_\mathcal{D},$$ with the property that a k-subset of $$\mathcal{P}$$ is a block of $$\mathcal{D}$$ if and only if its k elements sum up to zero. As a consequence, the group of automorphisms of any affine design $$\mathcal{D}$$ is the group of automorphisms of $${\mathfrak {G}}_\mathcal{D}$$ that leave $$\mathcal P$$ invariant. Whenever k is a prime p,  $${\mathfrak {G}}_\mathcal{D}$$ is an elementary abelian p-group.

Algebra and Number Theory010102 general mathematics0102 computer and information sciencesAutomorphism01 natural sciencesCombinatoricsKeywords Affine block designs · Hadamard designs · Additive designs · Mathieu group M11010201 computation theory & mathematicsSettore MAT/05 - Analisi MatematicaAdditive functionDiscrete Mathematics and CombinatoricsAffine transformationSettore MAT/03 - Geometria0101 mathematicsInvariant (mathematics)Abelian groupMathematics
researchProduct