Search results for "call"

showing 10 items of 2320 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.
researchProduct

Statistically Validated Networks for assessing topic quality in LDA models

2022

Probabilistic topic models have become one of the most widespread machine learning technique for textual analysis purpose. In this framework, Latent Dirichlet Allocation (LDA) (Blei et al., 2003) gained more and more popularity as a text modelling technique. The idea is that documents are represented as random mixtures over latent topics, where a distribution overwords characterizes each topic. Unfortunately, topic models do not guarantee the interpretability of their outputs. The topics learned from the model may be only characterized by a set of irrelevant or unchained words, being useless for the interpretation. Although many topic-quality metrics were proposed (Newman et al., 2009; Alet…

Settore SECS-S/06 -Metodi Mat. dell'Economia e d. Scienze Attuariali e Finanz.Settore SECS-S/01 - StatisticaTopic Model Topic Coherence LDA Statistically Validated Networks
researchProduct

Statistically Validated Networks for evaluating coherence in topic models

2022

Probabilistic topic models have become one of the most widespread machine learning technique for textual analysis purpose. In this framework, Latent Dirichlet Allocation (LDA) gained more and more popularity as a text modelling technique. The idea is that documents are represented as random mixtures over latent topics, where a distribution over words characterizes each topic. Unfortunately, topic models do not guarantee the interpretability of their outputs. The topics learned from the model may be characterized by a set of irrelevant or unchained words, being useless for the interpretation. In the framework of topic quality evaluation, the pairwise semantic cohesion among the top-N most pr…

Settore SECS-S/06 -Metodi Mat. dell'Economia e d. Scienze Attuariali e Finanz.Text Mining Probabilistic Topic Models Topic coherence Statistically Validated NetworksSettore SECS-S/01 - Statistica
researchProduct

MEASURING TOPIC COHERENCE THROUGH STATISTICALLY VALIDATED NETWORKS

2020

Topic models arise from the need of understanding and exploring large text document collections and predicting their underlying structure. Latent Dirichlet Allocation (LDA) (Blei et al., 2003) has quickly become one of the most popular text modelling techniques. The idea is that documents are represented as random mixtures over latent topics, where a distribution over words characterizes each topic. Unfortunately, topic models give no guaranty on the interpretability of their outputs. The topics learned from texts may be characterized by a set of irrelevant or unchained words. Therefore, topic models require validation of the coherence of estimated topics. However, the automatic evaluation …

Settore SECS-S/06 -Metodi Mat. dell'Economia e d. Scienze Attuariali e Finanz.topic model topic coherence LDA statistically validated networks.Settore SECS-S/01 - Statistica
researchProduct

STRANIERI, MERIDIONALI O PROVINCIALI? I CONSUMI NEL TEMPO LIBERO DELLE SECONDE GENERAZIONI

2022

In this paper, we analyze consumption patterns of leisure time among young people belonging to the so-called “second generation” of immigrants in Italy. Leisure time consumption describes how young immigrants use cultural products and services. We analyze data collected by the ISTAT through the survey on the “second generations” (2015). A comparison of leisure consumption patterns between second-generation immigrants and their Italian peers does not show significant differences. Rather, differences in consumption styles are associated to gender (male/female), geographic area of residence (North/South), and size of the municipality (large municipality/small municipality) of residence.

Settore SPS/07 - Sociologia GeneraleYoung immigrants Leisure time consumption Social integration Statistically validated networks.
researchProduct

Benralizumab Effectiveness in Severe Eosinophilic Asthma with and without Chronic Rhinosinusitis with Nasal Polyps: A Real-World Multicenter Study

2021

Background: Chronic rhinosinusitis with nasal polyps (CRSwNP) affects around 60% of patients with severe eosinophilic asthma (SEA). Benralizumab was recently approved for SEA add-on treatment. Objective: To assess the real-world effectiveness of benralizumab in SEA with or without CRSwNP. Methods: We conducted a multicenter observational study, including patients with SEA treated with benralizumab for 24 weeks in 12 Italian specialized facilities. Asthma exacerbations, Asthma Control Test (ACT), lung function, oral corticosteroid (OCS) dosage, and eosinophil and basophil count in peripheral blood were recorded at baseline and after 4, 12, and 24 weeks. The 22-item Sino-Nasal Outcome Test (S…

Severe asthmaVital capacitymedicine.medical_specialtymedicine.drug_classSettore MED/10 - Malattie Dell'Apparato RespiratorioAntibodies Monoclonal HumanizedFEV1/FVC ratiochemistry.chemical_compoundNasal PolypsInternal medicinemedicineHumansImmunology and AllergyNasal polypsAnti-Asthmatic AgentsIL-5Nasal polypbusiness.industryMinimal clinically important differenceBenralizumabFunctional endoscopic sinus surgeryrespiratory systemEosinophilBenralizumabmedicine.diseaseAsthmaChronic rhinosinusitismedicine.anatomical_structureReal-worldchemistryChronic rhinosinusitiCorticosteroidbusinessHumanThe Journal of Allergy and Clinical Immunology: In Practice
researchProduct

Numerical approach for signal delay in general distributed networks

2003

The authors consider a general network with telegraph equations modelling distributed elements and having, additionally, nonlinear capacitors. A global asymptotic exponential stability of the solution is given. A simple computable upper bound of the delay time is given. Numerical examples illustrate the usefulness of the results. >

Signal delayNumerical analysisMathematical analysisTime-scale calculusLambdaUpper and lower boundslaw.inventionNonlinear capacitanceCapacitorTheoryofComputation_MATHEMATICALLOGICANDFORMALLANGUAGESIntelligent NetworkExponential stabilityControl theorySimple (abstract algebra)lawApplied mathematicsDelay timeHardware_LOGICDESIGNMathematicsNetwork analysisVoltage[1987] NASECODE V: Proceedings of the Fifth International Conference on the Numerical Analysis of Semiconductor Devices and Integrated Circuits
researchProduct

Periodic time-domain modulation for the electrically tunable control of optical pulse train envelope and repetition rate multiplication

2012

An electrically tunable system for the control of optical pulse sequences is proposed and demonstrated. It is based on the use of an electrooptic modulator for periodic phase modulation followed by a dispersive device to obtain the temporal Talbot effect. The proposed configuration allows for repetition rate multiplication with different multiplication factors and with the simultaneous control of the pulse train envelope by simply changing the electrical signal driving the modulator. Simulated and experimental results for an input optical pulse train of 10 GHz are shown for different multiplication factors and envelope shapes. © 2006 IEEE.

Signal processingElectrically tunableMultiplication factorElectrical signalPhysics::Optics02 engineering and technologyOptical signal processingSimultaneous control01 natural sciencesOptical pulse train010309 opticsQ switched lasers020210 optoelectronics & photonicsOptics0103 physical sciencesTEORIA DE LA SEÑAL Y COMUNICACIONES0202 electrical engineering electronic engineering information engineeringTalbot effectPulse waveOptical fibersTime domainOptical fiber dispersionElectrical and Electronic EngineeringTemporal Talbot effectsEnvelope (waves)PhysicsTelecomunicacionesDispersive devicesRepetition rate multiplicationbusiness.industryOptical pulse shapingAtomic and Molecular Physics and OpticsPulse (physics)Optical signalsPhase modulationModulationTemporal Talbot effectElectro-optic modulatorsPulse trainOptical pulse sequencesDiffraction gratingsMultiplicationElectrónicaTime domainbusinessPhase modulation
researchProduct

A Simple Entropic-Driving Separation Procedure of Low-Size Silver Clusters, Through Interaction with DNA

2021

Abstract Synthesis and purification of metal clusters without strong binding agents by wet chemical methods are very attractive for their potential applications in many research areas. However, especially challenging is the separation of uncharged clusters with only a few number of atoms, which renders the usual techniques very difficult to apply. Herein, we report the first efficient separation of Ag2 and Ag3 clusters using the different entropic driving forces when such clusters interact with DNA, into which Ag3 selectively intercalates. After sequential dialysis of the samples and denaturalizing the DNA‐Ag3 complex, pure Ag2 can be found in the dialysate after extensive dialysis. Free Ag…

SilverResearch areasEntropyDna interactionIntercalation (chemistry)silver clustersMetal NanoparticlesChemical Fractionationchemistry.chemical_compoundseparation proceduresQD1-999Strong bindingmass spectrometryChemistryCommunicationentropically-driven processesGeneral ChemistryDNAIntercalating AgentsCommunicationsDNA interactionChemistryChemical physicsSettore CHIM/03 - Chimica Generale E InorganicaDialysis (biochemistry)DNAMetal clustersSeparation procedure
researchProduct

Examination of the Helminth Fauna of the Bermuda Skink, Plestiodon longirostris (Scincidae), Utilizing Faecal Analysis

2021

Plestiodon longirostris is a critically endangered endemic skink living in the Bermuda archipelago. To know their intestinal parasites and evaluate the role that they may have in the conservation of the species, we have carried out a faecal analysis of some samples obtained from several populations. This type of analysis is presented as the most suitable for threatened species. The results show that P. longirostris has incorporated parasites from introduced species in Bermuda, and it is a competent host for these parasites. Nevertheless, the low prevalence of infection of these parasites suggests that they are not actually a threat to the endemic skink populations.

SkinkCritically endangeredMultidisciplinaryPlestiodonbiologyHost (biology)FaunaThreatened speciesZoologyHelminthsIntroduced speciesbiology.organism_classificationCaribbean Journal of Science
researchProduct