Search results for "Statistica"
showing 10 items of 5969 documents
Optimization of Linearized Belief Propagation for Distributed Detection
2020
In this paper, we investigate distributed inference schemes, over binary-valued Markov random fields, which are realized by the belief propagation (BP) algorithm. We first show that a decision variable obtained by the BP algorithm in a network of distributed agents can be approximated by a linear fusion of all the local log-likelihood ratios. The proposed approach clarifies how the BP algorithm works, simplifies the statistical analysis of its behavior, and enables us to develop a performance optimization framework for the BP-based distributed inference systems. Next, we propose a blind learning-adaptation scheme to optimize the system performance when there is no information available a pr…
Modeling and Mitigating Errors in Belief Propagation for Distributed Detection
2021
We study the behavior of the belief-propagation (BP) algorithm affected by erroneous data exchange in a wireless sensor network (WSN). The WSN conducts a distributed multidimensional hypothesis test over binary random variables. The joint statistical behavior of the sensor observations is modeled by a Markov random field whose parameters are used to build the BP messages exchanged between the sensing nodes. Through linearization of the BP message-update rule, we analyze the behavior of the resulting erroneous decision variables and derive closed-form relationships that describe the impact of stochastic errors on the performance of the BP algorithm. We then develop a decentralized distribute…
La disuguaglianza socio-economica della salute come indicatore di benessere sociale
2016
Obiettivo: Misurare il benessere sociale attraverso l’utilizzo della disuguaglianza socioeconomica della salute percepita dalle famiglie italiane e quantificare i contributi dei determinanti della salute alla disuguaglianza misurata. Materiali e metodi: Sono utilizzati i dati dell’indagine Istat sulle condizioni di vita (UDB IT-SILC), componente longitudinale. L’analisi è effettuata su un sotto-campione di 11.543 individui e 12 variabili, ottenuto dopo aver eliminato i dati mancanti per la variabile reddito e per le altre variabili rilevanti per la salute. E’ applicato il modello di regressione probit ordinale, per ottenere una misura continua della variabile salute, l’indice di concentrazi…
Flow dominance and factorization of transverse momentum correlations in Pb-Pb collisions at the LHC
2017
Physical review letters 118(16), 162302 (2017). doi:10.1103/PhysRevLett.118.162302
Hepatitis C Virus positive patients with persistently normal serum transaminase: a long-term follow-up
2010
Review of Particle Physics
2020
The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 2,143 new measurements from 709 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. Particle properties and search limits are listed in Summary Tables. We give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders, …
Using Differential Geometry for Sparse High-Dimensional Risk Regression Models
2023
With the introduction of high-throughput technologies in clinical and epidemiological studies, the need for inferential tools that are able to deal with fat data-structures, i.e., relatively small number of observations compared to the number of features, is becoming more prominent. In this paper we propose an extension of the dgLARS method to high-dimensional risk regression models. The main idea of the proposed method is to use the differential geometric structure of the partial likelihood function in order to select the optimal subset of covariates.
Turismo e social network. L'immagine della destinazione Sicilia nel passaparola di Facebook.
2014
DOTTOR DIVAGO Discernere, Valutare e Governare la Nuova Università
2008
Un indicatore composto della qualità della didattica: dalle scale ordinali alle metriche di importanza relativa.
2008
Il problema della ponderazione nella costruzione di un indicatore composto, pur essendo determinante per il valore della misura sintetica, non trova ancora risposte soddisfacenti nell’attuale panorama della letteratura dedicata all’argomento. Un tentativo per la costruzione di un sistema di pesi è effettuato sulla base di un modello di regressione lineare multipla attraverso misure di importanza relativa. In presenza di regressori correlati l’usuale output del modello di regressione non è adeguato per fornire tali misure. Si fa ricorso ai metodi per la scomposizione di R2 e, tra quelli riscontrati in letteratura, se ne esaminano due: LMG e PMVD. Questi ultimi, entrambi basati su medie degli…