Search results for "ERROR"

showing 10 items of 1643 documents

Indoor free space optics link under the weak turbulence regime: Measurements and model validation

2015

In this study, the authors present the measurements performed on a free space optics (FSO) communications link using an indoor atmospheric chamber. In particular, the authors have generated several different optical turbulence conditions, demonstrating how even the weak turbulence regime can strongly affect the FSO link performance. The authors have carried out an in-depth analysis of the data collected during the measurements, and calculated the turbulence strength (i.e. scintillation index and Rytov variance) and the important performance metrics (i.e. the Q-factor and bit error rate) to evaluate the FSO link quality. Moreover, the authors have tested, for the first time, an appositely de…

Time seriesComputer scienceOptical linksIrradianceGamma gamma channel modelSettore ING-INF/01 - ElettronicaScintillation indexoptical turbulenceQuality (physics)TEORIA DE LA SEÑAL Y COMUNICACIONESStatistical physicsError statisticsElectrical and Electronic EngineeringComunicació i tecnologiaScintillationtime-correlated channel modelbusiness.industryTurbulenceSettore ING-INF/03 - TelecomunicazioniIndoor atmospheric chamberRytov varianceAtmospheric turbulenceExperimental dataQ-factorTurbulence strengthSettore ING-INF/02 - Campi ElettromagneticiÒpticaComputer Science ApplicationsBit error rateQ factorFree Space OpticBit error rateGamma-Gamma modelIndoor free space optics communications linkTelecommunicationsbusinessFree-space optical communicationindoor link
researchProduct

Application of the group method of data handling (GMDH) approach for landslide susceptibility zonation using readily available spatial covariates

2022

Abstract Landslide susceptibility (LS) mapping is an essential tool for landslide risk assessment. This study aimed to provide a new approach with better performance for landslide mapping and adopting readily available variables. In addition, it investigates the capability of a state-of-the-art model developed using the group method of data handling (GMDH) to spatially model LS. Furthermore, hybridized models of GMDH were developed using different metaheuristic algorithms. The study area was the Bonghwa region of South Korea, for which an accurate landslide inventory dataset is available. We considered a total of 13 spatial covariates (altitude, slope, aspect, topographic wetness index, val…

Topographic Wetness IndexVariablesReceiver operating characteristicMean squared errorGroup method of data handlingmedia_common.quotation_subjectLandslideArtificial intelligence Data-scarcity Factor selection GIS Natural disasterscomputer.software_genreRegressionCovariateData miningcomputerEarth-Surface Processesmedia_commonMathematicsCATENA
researchProduct

Factors selection in landslide susceptibility modelling on large scale following the gis matrix method: application to the river Beiro basin (Spain)

2012

A procedure to select the controlling factors connected to the slope instability has been defined. It allowed us to assess the landslide susceptibility in the Rio Beiro basin (about 10 km2) over the northeastern area of the city of Granada (Spain). Field and remote (Google EarthTM) recognition techniques allowed us to generate a landslide inventory consisting in 127 phenomena. To discriminate between stable and unstable conditions, a diagnostic area had been chosen as the one limited to the crown and the toe of the scarp of the landslide. 15 controlling or determining factors have been defined considering topographic, geologic, geomorphologic and pedologic available data. Univariate tests, …

TopographyGranadaSettore GEO/04 - Geografia Fisica E GeomorfologiaForecast skillStructural basinConditional analysis methodlcsh:TD1-1066Goodness of fitApproximation errorStatisticslandslide susceptibilitylcsh:Environmental technology. Sanitary engineeringlcsh:Environmental scienceslcsh:GE1-350Beiro river basinlcsh:QE1-996.5UnivariateGoogle Earthlcsh:Geography. Anthropology. RecreationLandslideField (geography)matrix methodlcsh:Geologylcsh:GBetic CordilleraGeneral Earth and Planetary SciencesGoogle Earth; landslide susceptibility; Beiro river basin; matrix method;Scale (map)GeologyNatural Hazards and Earth System Sciences
researchProduct

Los porqués del 11-S

2002

Torres GemelasCooperaciónNueva YorkVidal-Beneyto José11-STropas soviéticasIntegristas islámicosTerrorismoEstado fundamentalistaDispositivo bélicoBin LadenAlianzaGuerra santaTalibanesPublicaciones: Obra periodística: Columnas y artículos de opiniónPorquésCIAAtaque terroristaOriente PróximoPentágonoAl QaedaEEUUAfganistánArabia Saudí
researchProduct

Genocide, torture, and terrorism: ranking international crimes and justifying humanitarian intervention

2018

TorturePolitical sciencePolitical Science and International RelationsTerrorismGenocideCriminologyHumanitarian interventionLawRanking (information retrieval)Journal of Policing, Intelligence and Counter Terrorism
researchProduct

22. Administering Face-To-Face Structured Questionnaires In Tourism Research

2018

Non-sampling errors occur in all social sciences, tourism included. Apart from coverage and non-response, tourism research suffers from noteworthy measurement errors. The limitation and control of non-sampling errors plays a key role to prevent serious biases in research outputs. The entire survey design process could be based on the control and reduction of non-sampling errors. From this point of view, face-to-face interviewing represents an effective response to some common threats to data quality, particularly errors attributable to respondents and non-response.

Total Survey Errors (TSE)Face-to-Face interviewingNon-sampling errors (NSE)Settore SECS-S/05 - Statistica Sociale
researchProduct

Prediction of organic carbon and total nitrogen contents in organic wastes and their composts by Infrared spectroscopy and partial least square regre…

2017

Middle and near infrared (MIR and NIR) were employed to determine organic carbon (OC) and total nitrogen (TN) in different soil organic amendments including wastes, composts and mixtures of composts and organic wastes. Prediction models based on partial least squares (PLS) regression from the spectra of untreated samples were built. Different spectra preprocessing strategies were adopted and the best number of latent variable was evaluated using leave-one-out cross-validation. Attenuated total reflectance (PLS-ATR-MIR) and diffuse reflectance (PLS-DR-NIR) models were built and evaluated from root mean square error of cross validation and prediction (RMSECV and RMSEP), coefficients of determ…

Total organic carbonMean squared errorChemistryAnalytical chemistryInfrared spectroscopy04 agricultural and veterinary sciences010501 environmental sciencesResidual01 natural sciencesCross-validationAnalytical ChemistryAttenuated total reflectionPartial least squares regression040103 agronomy & agricultureTotal nitrogen0401 agriculture forestry and fisheries0105 earth and related environmental sciencesTalanta
researchProduct

Totalitarismo y dictadura: Arendt para leer la historia reciente de Chile

2017

***Totalitarianism and dictatorship: Arendt to read chilean’s recent history***This article seeks to expose and discuss the pertinence or inpertinence of two key concepts in the thinking of Hannah Arendt, to describe and understand fundamental processes of Chile's recent history: In one hand, 'totalitarianism' as a regime founded on Terror to refer to the dictatorship of Augusto Pinochet that took place between 1973 and 1989. In other hand 'labor society' as a form of post-totalitarian society, oriented to labor and consumption, to describe one of the central aspects of the neoliberal society that the Chilean dictatorship installs. Este artículo busca exponer y discutir la pertinencia o la …

TotalitarismoHistoryNeoliberalismArendt.NeoliberalismoTerrorismoConsumption (sociology)DictatorshipTerrorTotalitarianismDictatorshipPolitical scienceDitaduraHumanitiesDictaduraEstudos Ibero-Americanos
researchProduct

L’indagine sulla mobilità turistica: strumenti di rilevazione

2010

This paper discusses the features and the structure of the interview forms used within the sample research on tourist mobility carried out in Sicily and Sardinia in years 2009 and 2010. The focus of the paper is on the strategies adopted by the research team in order to control non sampling errors. The limitations of the instruments respect to the secondary purposes of the research will be discussed as well.

Tourist mobilityInterviewSettore SECS-S/05 - Statistica SocialeNon-sampling errorsTourism
researchProduct

The research on the mobility of tourists in Sicily: detection and estimation of non-sampling errors

2011

Tourist mobilityNon-sampling errorSettore SECS-S/05 - Statistica SocialeSicily
researchProduct