Search results for "sampling"
showing 10 items of 788 documents
The Multilevel Model in the Computer-Generated Appraisal: A Case in Palermo
2017
The construction of a mass appraisal model requires the preliminary study of the real estate market, the sampling of sold properties, the development of a forecasting model and the verification of the appraisal results. They are generally computerised methods, that work with geo-referenced data. This experimental work has proceeded to build a mass appraisal model, collecting a data sample of sales of apartments in the city of Palermo, in the five years 2008–2012, using a multivariate statistical model (multilevel), testing the results and providing the operating applications in a scheme of online real estate valuations.
Thompson Sampling Guided Stochastic Searching on the Line for Adversarial Learning
2015
The multi-armed bandit problem has been studied for decades. In brief, a gambler repeatedly pulls one out of N slot machine arms, randomly receiving a reward or a penalty from each pull. The aim of the gambler is to maximize the expected number of rewards received, when the probabilities of receiving rewards are unknown. Thus, the gambler must, as quickly as possible, identify the arm with the largest probability of producing rewards, compactly capturing the exploration-exploitation dilemma in reinforcement learning. In this paper we introduce a particular challenging variant of the multi-armed bandit problem, inspired by the so-called N-Door Puzzle. In this variant, the gambler is only tol…
Analisi delle evidenze epidemiologiche sui fattori di rischio indoor per malattie respiratorie e allergiche nelle strutture scolastiche [Analysis of …
2012
Il diritto a respirare aria sana nelle scuole è stato sancito già nell’anno 2001 in un documento dell’European Federation of Asthma and Allergy Associations che ha evidenziato scarsa attenzione e assenza di direttive specifiche dell’Unione Europea relativamente agli effetti sulla salute da inquinamento dell’aria nelle scuole, ed è sostenuto dal numero enorme di bambini e ragazzi che frequentano le aule scolastiche. Negli ultimi anni, a livello europeo si è sviluppato un sempre crescente interesse nei confronti dell’effetto della qualità dell’aria dell’indoor scolastico (IAQ) sulla salute dei ragazzi, e sono stati avviati numerosi progetti di ricerca internazionali mirati, appunto, a determi…
Finnish Students’ Engagement in Science Lessons
2015
The decreasing number of students who are engaged in science learning has been recognised as a problem. The pre-conditions of engagement and actual engagement were examined using a novel research method to obtain detailed information on Finnish students’ engagement in different situations and to gain a better understanding of this phenomenon. The study’s participants consisted of 68 students (31 girls, 37 boys) from 9th grade and 67 students (46 girls, 21 boys) from 1st grade in upper secondary school. The research aimed to answer the following question: How does Finnish students’ engagement occur in exact and life science lessons? Participants received smartphones equipped with a smartphon…
Optional Sampling Theorems
2020
In Chapter 9 we saw that martingales are transformed into martingales if we apply certain admissible gambling strategies. In this chapter, we establish a similar stability property for martingales that are stopped at a random time (optional sampling and optional stopping). In order also to obtain these results for submartingales and supermartingales, in the first section, we start with a decomposition theorem for adapted processes. We show the optional sampling and optional stopping theorems in the second section. The chapter finishes with the investigation of random stopping times with an infinite time horizon.
Conceptions associated with sense of belonging in different school placements for Finnish pupils with special education needs
2015
AbstractThe aim of this study was to examine conceptions associated with sense of belonging (SEBE) in Finnish general and special school placements for pupils with special education needs. Five pupils were selected for this study by means of purposive sampling. They had a history of several school placements prior to arriving at their current special school. Qualitative phenomenographic analyses of interview transcripts revealed numerous conceptions regarding the pupils’ SEBE in the different educational placements. The pupils had undergone numerous placements in which their SEBE had been jeopardised, as disturbing relationships with teachers and peers seemed to have affected the pupils’ me…
Experimental approach for testing the uncoupling between cardiovascular variability series
2002
In cardiovascular variability analysis, the significance of the coupling between two series is commonly assessed by defining a zero level on the magnitude-squared coherence (MSC). Although the use of the conventional value of 0.5 does not consider the dependence of MSC estimates on the analysis parameters, a theoretical threshold Tt is available only for the weighted covariance (WC) estimator. In this study, an experimental threshold for zero coherence Te was derived by a statistical test from the sampling distribution of MSC estimated on completely uncoupled time series. MSC was estimated by the WC method (Parzen window, spectral bandwidth B = 0.015, 0.02, 0.025, 0.03 Hz) and by the parame…
Proposal of reference values of microbiological environment monitoring in foodservice establishments
2015
Introducción: Proponer una nueva referencia microbiológica ambiental en los servicios de restauración. Objetivo: El presente trabajo muestra la determinación y evaluación de la contaminación microbiológica generada en un establecimiento de servicio de alimentos. Método: Se basa en el muestreo microbiológico de superficie utilizando filtros de membrana de ésteres mixtos de celulosa y en el muestreo de aire utilizando placas de Petri. Resultados: Los límites de contaminación se establecieron antes y durante la elaboración de alimentos, mediante el análisis microbiológico de las superficies y del medio ambiente, sistemas de equipos, hasta límites confiables y estableciendo niveles de aceptació…
A comparative analysis of different spatial sampling schemes: Modelling of SSRB data
2008
Low spatial resolution satellite sensors provide information over relatively large targets with typical pixel resolutions of hundreds of km2. However, the spatial scales of ground measurements are usually much smaller. Such differences in spatial scales makes the interpretation of comparisons between quantities derived from low resolution sensors and ground measurements particularly difficult. It also highlights the importance of developing appropriate sampling strategies when designing ground campaigns for validation studies of low resolution sensors. We make use of statistical modelling of high resolution surface shortwave radiation budget (SSRB) data to look into this problem. A spatial …
Working with (too) Few Samples
2018
This paper is concerned with gene set differential expression analysis. We compare the transcriptomic behaviour of each gene set between different experimental conditions.The gene set is previously defined. It has been used a gene set collection downloaded from Gene Ontology.A randomization test is proposed and compared with other previous procedures using a RNA-seq experiment of colorectal cancer (CRC).