Search results for "Latency"

showing 10 items of 135 documents

Design and analysis of discrete choice experiments for models with response time

2013

Settore SECS-S/02 - Statistica Per La Ricerca Sperimentale E TecnologicaA sector of conjoint analysis (experimental design in marketing research) is made of the so called choice experiments. In choice experiments respondents undergo a questionnaire which is nowadays mostly submitted through the internet. The questionnaire proposes to the respondent a sequence of choice sets each one including two or more profiles being a profile a specific combination of attribute levels. The respondent selects the preferred profile for each choice set. Responses given by a sample of respondents are analysed through suitable methods aimed to eventually find the best combination of attribute levels. One method of analysis adopts the Multinomial Logit (MLN) model. In this article the authors show the results of the MLN analysis compared with another model of analysis which uses an additional response which can be easily recorded by electronically submitted questionnaires. In practice modern survey platforms like “Qualtrics” (the one used for this work) can record the so called “response latency” i.e. the time taken by the respondent to make the choice and select the most preferred profile in the choice set. Thanks to a response latency model further refined in this work it is possible to deduce the relative weight of importance of the profiles for each choice set and respondent. This type of response can be used in place of the dichotomous choice variable in the MLN model. The two models and methods of analysis are deeply compared and it is critically discussed when it is better to use one or the other method. As a result a more reliable estimate of the optimal profile comes up implying lower risks for new investments and marketing decisions.
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Prioritisation of alternatives with analytical hierarchy process plus response latency and web surveys

2014

This paper introduces a new method that combines the well-known analytical hierarchy process (AHP) with a response latency metric. The response latency is the time taken by respondents to make choices over pairwise comparisons. The analytical calculation of relative importance weights of the alternatives is made by using a response latency model previously validated in several case studies. This combination aims to overcome some drawbacks of the traditional AHP related to the use of a rating scale (the so-called Saaty scale), and it is a natural way to involve response latency in established decisionmaking methods. This new method can be profitably adopted in web surveys where it is easy to…

Settore SECS-S/02 - Statistica Per La Ricerca Sperimentale E Tecnologicabusiness.industryComputer scienceattribute ratingAnalytic hierarchy processrelative importance weightweb surveysMachine learningcomputer.software_genreGeneral Business Management and Accountingresponse latencyanalytical hierarchy proceRating scaleRespondentEconometricspairwise comparisonPairwise comparisonArtificial intelligenceLatency (engineering)New service developmentbusinesscomputerprioritisationTotal Quality Management & Business Excellence
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Percentile Reference Charts for Selected Sleep Parameters for 20- to 80-Year-Old Healthy Subjects from the SIESTA Database. Referenzkurven fur ausgew…

2005

One of the aims of the SIESTA project was to establish a normative database of sleep parameters for healthy and sleep-disturbed patients. Reference data for sleep parameters in non-sleep-disturbed subjects are scarce and usually refer to means and standard deviations. However, since most of the parameters do not follow a Gaussian distribution, percentiles of the distribution provide more detailed information. The present results are based on data from 198 healthy, non-sleep-disturbed subjects (104 females) in the age range of 20 to 95 years. For every subject, two consecutive nights were polysomnographically recorded in one of the eight participating clinical centres. Percentile charts were…

Sleep disordermedicine.medical_specialtyPercentileNeurologyRapid eye movement sleepAudiologymedicine.diseaseDevelopmental psychologySiestaSample size determinationPhysiology (medical)medicineSleep onset latencySleep (system call)PsychologySomnologie
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Statistical analysis of latency outcomes in behavioral experiments

2011

In experimental designs of animal models, memory is often assessed by the time for a performance measure to occur (latency). Depending on the cognitive test, this may be the time it takes an animal to escape to a hidden platform (water maze), an escape tunnel (Barnes maze) or to enter a dark component (passive avoidance test). Latency outcomes are usually statistically analyzed using ANOVAs. Besides strong distributional assumptions, ANOVA cannot properly deal with animals not showing the performance measure within the trial time, potentially causing biased and misleading results. We propose an alternative approach for statistical analyses of latency outcomes. These analyses have less distr…

Spatial BehaviorMorris water navigation taskWater mazeBehavioral neuroscienceMachine learningcomputer.software_genreArticleDevelopmental psychologyBehavioral NeuroscienceAvoidance LearningReaction TimeAnimalsLatency (engineering)Maze Learningbusiness.industryRetention PsychologyBarnes mazeCognitive testSample size determinationData Interpretation StatisticalSample SizeModels AnimalData DisplayAnalysis of varianceArtificial intelligencePsychologybusinesscomputerBehavioural Brain Research
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A heuristic method for estimating attribute importance by measuring choice time in a ranking task

2012

The evaluation of a product or service in terms of its attributes has been broadly studied in marketing, management and decision sciences. However, methods for finding important attributes have theoretical and practical limitations. The former are related to the selection of the most appropriate model; the latter are due to large number of variables that affect the specific experimental context. This study aims to present a new methodology that captures attribute preferences from a respondent and in particular, by using the choice time in a ranking task, it allows to indirectly obtain the importance weights for several tested attributes through a simple, fast and inexpensive procedure. More…

Statistics and ProbabilityEconomics and EconometricsService (systems architecture)HeuristicComputer scienceSettore SECS-S/02 - Statistica Per La Ricerca Sperimentale E TecnologicaVariable and attributeContext (language use)computer.software_genreTask (project management)RankingRespondentData miningStatistics Probability and UncertaintySettore SECS-S/01 - StatisticacomputerFinanceSelection (genetic algorithm)CHOICE TIME response time response latency attribute rating choice models
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Influence of ventral tegmental area (A10 region) on flight behaviour elicited by hypothalamic stimulation in the cat.

1993

The influence of the ventral tegmental area (VTA) (dopaminergic A10 group neurons) on flight behaviour, induced by hypothalamic stimulation, was studied in the cat. Co-stimulation of hypothalamus and VTA (ipsi- or contralateral) induced an increase of the flight latency. Slow-motion analysis of flight behaviour showed that this increase was due to the augmentation of the fixation latency (FL) whereas the upright latency (UL) was not modified. Sulpiride injection (50 mg/kg i.p.) provoked the disappearance of VTA effect without affecting the basal behavioural sequence. The results show that DA A10 group neurons increase the attentive component of the flight reaction, suggesting a possible inf…

Tegmentum MesencephaliDopamineCentral nervous systemHypothalamusEscape ReactionmedicineCarnivoraAnimalsAnesthesiaAttentionLatency (engineering)Molecular BiologyNeuronsbiologyChemistryGeneral NeuroscienceFissipediaDopaminergicbiology.organism_classificationElectric StimulationVentral tegmental areamedicine.anatomical_structurenervous systemHypothalamusCatsNeurology (clinical)SulpirideSulpirideNeuroscienceDevelopmental Biologymedicine.drugBrain research
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Brain Cortical Complexity and Subcortical Morphometrics in Lifelong Premature Ejaculation

2020

Premature ejaculation (PE) is the most common male sexual dysfunction. The brain disturbances that cause this disorder remain poorly understood. This study aimed to investigate how the morphology of cortical and subcortical brain structures differed in PE, how these morphologic differences were associated with severity measures of PE, such as intravaginal ejaculatory latency time (IELT), and how these cortical and subcortical structures were causally connected through mediation analysis. Anatomical MRI scans were acquired from 39 male participants, 23 with PE (28.78 ± 4.32 years), and 16 without PE (27.88 ± 3.65 years). We used a subcortical analysis package within FSL to perform subcortica…

Thalamusgyrification index050105 experimental psychologylcsh:RC321-57103 medical and health sciencesBehavioral Neuroscience0302 clinical medicinePremature ejaculationmorphologymedicine0501 psychology and cognitive sciencesStatistical analysisRight nucleus accumbensmediation analysislcsh:Neurosciences. Biological psychiatry. NeuropsychiatryGyrificationBiological PsychiatryOriginal ResearchMorphometricsbusiness.industry05 social sciencesHuman NeuroscienceAnatomyComputational anatomyEjaculatory latencypremature ejaculationPsychiatry and Mental healthNeuropsychology and Physiological PsychologyNeurologymedicine.symptombusiness030217 neurology & neurosurgeryvertex analysisFrontiers in Human Neuroscience
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Immune Evasion Proteins Enhance Cytomegalovirus Latency in the Lungs

2009

ABSTRACT CD8 T cells control cytomegalovirus (CMV) infection in bone marrow transplantation recipients and persist in latently infected lungs as effector memory cells for continuous sensing of reactivated viral gene expression. Here we have addressed the question of whether viral immunoevasins, glycoproteins that specifically interfere with antigen presentation to CD8 T cells, have an impact on viral latency in the murine model. The data show that deletion of immunoevasin genes in murine CMV accelerates the clearance of productive infection during hematopoietic reconstitution and leads to a reduced latent viral genome load, reduced latency-associated viral transcription, and a lower inciden…

Transcription GeneticImmunologyAntigen presentationAntigen-Presenting CellsCytomegalovirusBone Marrow CellsGenome ViralCD8-Positive T-LymphocytesBiologymedicine.disease_causeMicrobiologyHerpesviridaeVirusMiceImmune systemRecurrenceVirologyVirus latencymedicineAnimalsCytotoxic T cellAntigen-presenting cellLungGlycoproteinsMice Inbred BALB Cmedicine.diseaseVirologyVirus LatencyInsect ScienceCytomegalovirus InfectionsImmunologyPathogenesis and ImmunityFemaleViral diseaseJournal of Virology
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CD8 T Cells Control Cytomegalovirus Latency by Epitope-Specific Sensing of Transcriptional Reactivation

2006

ABSTRACT During murine cytomegalovirus (mCMV) latency in the lungs, most of the viral genomes are transcriptionally silent at the major immediate-early locus, but rare and stochastic episodes of desilencing lead to the expression of IE1 transcripts. This low-frequency but perpetual expression is accompanied by an activation of lung-resident effector-memory CD8 T cells specific for the antigenic peptide 168-YPHFMPTNL-176, which is derivedfrom the IE1 protein. These molecular and immunological findings were combined in the “silencing/desilencing and immune sensing hypothesis” of cytomegalovirus latency and reactivation. This hypothesis proposes that IE1 gene expression proceeds to cell surfac…

Transcriptional ActivationMuromegalovirusvirusesImmunologyAntigen presentationCD8-Positive T-LymphocytesVirus ReplicationMajor histocompatibility complexModels BiologicalMicrobiologyEpitopeImmediate-Early ProteinsEpitopesImmunocompromised HostMiceAntigenVirologyMHC class IVirus latencymedicineAnimalsGene silencingCytotoxic T cellAmino Acid SequenceAntigens ViralLungBone Marrow TransplantationMice Inbred BALB CBase Sequencebiologyvirus diseasesHerpesviridae Infectionsbiochemical phenomena metabolism and nutritionmedicine.diseaseVirologyMolecular biologyVirus LatencyVirus-Cell InteractionsPhenotypeAmino Acid SubstitutionInsect ScienceDNA ViralMutagenesis Site-DirectedTrans-Activatorsbiology.proteinFemaleJournal of Virology
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Discrete-time multioverlapping controller design for structural vibration control of tall buildings under seismic excitation

2012

Published version of an article from the journal: Mathematical Problems in Engineering. Also available from the publisher:http://dx.doi.org/10.1155/2012/636878 In this paper, a computationally effective strategy to obtain multioverlapping controllers via the Inclusion Principle is applied to design discrete-time state-feedback multioverlapping LQR con- trollers for seismic protection of tall buildings. To compute the corresponding control actions, the proposed semidecentralized controllers only require state information from neighboring stories. This particular configuration of information exchange allows introducing a dramatic reduction in the transmission range required for a wireless imp…

VDP::Mathematics and natural science: 400::Mathematics: 410::Applied mathematics: 413EngineeringArticle Subject:Informàtica::Automàtica i control [Àrees temàtiques de la UPC]General MathematicsLatency (audio)Edificis -- Vibració:Enginyeria civil::Materials i estructures [Àrees temàtiques de la UPC]Feedback control systemsCommunications systemControl d'estructures (Enginyeria)Earthquake resistant designSampling (signal processing):93 Systems Theory; Control [Classificació AMS]Control theoryControlWirelessBuildings -- VibrationInformation exchange:93 Systems Theory [Classificació AMS]business.industryVDP::Technology: 500::Building technology: 530Disseny antisísmiclcsh:MathematicsGeneral EngineeringControl engineeringlcsh:QA1-939Transmission (telecommunications)Discrete time and continuous timelcsh:TA1-2040Sistemes de control per retroaccióBuildings--VibrationStructural control (Engineering)businessReduction (mathematics)lcsh:Engineering (General). Civil engineering (General)
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