Benvenuti nell'Anagrafe della Ricerca d'Ateneo
La valutazione delle attività di ricerca che si svolgono nelle università ha assunto un'importanza rilevante sia per l'intero sistema universitario sia all'interno di ogni singolo ateneo. Roma Tre si è quindi dotata di idonei strumenti informativi in grado di supportare al meglio le azioni di monitoraggio e di valutazione delle attività di ricerca svolte nei propri dipartimentied ha realizzato una Anagrafe della Ricerca di Ateneo.
EnglishLongitudinal data are often segmented by unobserved time-varying factors, which introduce latent heterogeneity at the observation level, in addition to heterogeneity across subjects. We account for this latent structure by a linear mixed hidden Markov model. It integrates subject-specific random effects and Markovian sequences of time-varying effects in the linear predictor. We propose an expectationŰ-maximization algorithm for maximum likelihood estimation, based on data augmentation. It reduces to the iterative maximization of the expected value of a complete likelihood function, derived from an augmented dataset with case weights, alternated with weights updating. In a case study of the Survey on Stress Aging and Health in Russia, the model is exploited to estimate the influence of the observed covariates under unobserved time-varying factors, which affect the cardiovascular activity of each subject during the observation period.
LAGONA F, JDANOV D, & SHKOLNIKOVA M (2014). Latent time-varying factors in longitudinal analysis: a linear mixed hidden Markov model for heart rates. STATISTICS IN MEDICINE, 33(23), 4116-4134.
| Titolo: | Latent time-varying factors in longitudinal analysis: a linear mixed hidden Markov model for heart rates |
| Autori: | |
| Data di pubblicazione: | 2014 |
| Rivista: | |
| Citazione: | LAGONA F, JDANOV D, & SHKOLNIKOVA M (2014). Latent time-varying factors in longitudinal analysis: a linear mixed hidden Markov model for heart rates. STATISTICS IN MEDICINE, 33(23), 4116-4134. |
| Abstract: | Longitudinal data are often segmented by unobserved time-varying factors, which introduce latent heterogeneity at the observation level, in addition to heterogeneity across subjects. We account for this latent structure by a linear mixed hidden Markov model. It integrates subject-specific random effects and Markovian sequences of time-varying effects in the linear predictor. We propose an expectationŰ-maximization algorithm for maximum likelihood estimation, based on data augmentation. It reduces to the iterative maximization of the expected value of a complete likelihood function, derived from an augmented dataset with case weights, alternated with weights updating. In a case study of the Survey on Stress Aging and Health in Russia, the model is exploited to estimate the influence of the observed covariates under unobserved time-varying factors, which affect the cardiovascular activity of each subject during the observation period. |
| Handle: | http://hdl.handle.net/11590/142600 |
| Appare nelle tipologie: | 1.1 Articolo in rivista |
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