Search results for "Mixture model"
showing 10 items of 86 documents
Barriers to outdoor physical activity and unmet physical activity need in older adults
2014
Abstract Objective To profile participants based on reported outdoor physical activity barriers using a data-driven approach, describe the profiles and study their association with unmet physical activity need. Method Cross-sectional analyses of 848 community-dwelling men and women aged 75–90 living in Central Finland in 2012. Barriers to outdoor physical activity and unmet physical activity need were enquired with a questionnaire. The latent profiles were identified by profiling participants into latent groups using a mixture modeling technique on the multivariate set of indicators of outdoor physical activity barriers. A path model was used to study the associations of the profiles with u…
Identifying childhood movement profiles and comparing differences in mathematical skills between clusters : A latent profile analysis
2021
The aims of this study were; 1) to identify different movement profiles in sixth graders, and 2) to investigate if there are differences in their mathematical basic (BasicMath) and problem solving (ProbSol) skills between existing movement profiles. The sample included 461 (223 girls, 238 boys) students with a mean age of 11.27 +/- .32 years from southern and middle Finland. A latent profile analysis (LPA) revealed four movement profiles: "poor movers", "average movers", "skilled movers" and "expert movers". These profiles differed substantially in their motor competence (MC) and health-related fitness (HRF). A multivariate analysis of variance (MANOVA) also revealed that "poor movers" and …
A Bayesian direction-of-arrival model for an undetermined number of sources using a two-microphone array.
2014
Sound source localization using a two-microphone array is an active area of research, with considerable potential for use with video conferencing, mobile devices, and robotics. Based on the observed time-differences of arrival between sound signals, a probability distribution of the location of the sources is considered to estimate the actual source positions. However, these algorithms assume a given number of sound sources. This paper describes an updated research account on the solution presented in Escolano et al. [J. Acoust. Am. Soc. 132(3), 1257-1260 (2012)], where nested sampling is used to explore a probability distribution of the source position using a Laplacian mixture model, whic…
Analysis and modeling of Temporal Dominance of Sensations with stochastic processes
2019
Temporal Dominance of Sensations (TDS) is a technique to measure temporal perception of food product during tasting. For a panelist, it consists in choosing in a list of attributes which one is dominant at any time. This work aims to model TDS data with a stochastic process and proposes to use semi-Markov processes (SMP), a generalization of Markov chains which allows dominance durations to be modeled by any type of distribution. The model can then be used to compare TDS samples based on likelihood ratio. Because probabilities of transition from one attribute to another one can also depend on time, we propose to model TDS by period and we propose a method to select optimally the number of p…
Analysis and modeling of Temporal Dominance of Sensations with stochastic processes
2019
Temporal Dominance of Sensations (TDS) is a technique to measure temporal perception of food product during tasting. For a panelist, it consists in choosing in a list of attributes which one is dominant at any time. This work aims to model TDS data with a stochastic process and proposes to use semi-Markov processes (SMP), a generalization of Markov chains which allows dominance durations to be modeled by any type of distribution. The model can then be used to compare TDS samples based on likelihood ratio. Because probabilities of transition from one attribute to another one can also depend on time, we propose to model TDS by period and we propose a method to select optimally the number of p…
2015
We present a method to discover discriminative brain metabolism patterns in [18F] fluorodeoxyglucose positron emission tomography (PET) scans, facilitating the clinical diagnosis of Alzheimer's disease. In the work, the term "pattern" stands for a certain brain region that characterizes a target group of patients and can be used for a classification as well as interpretation purposes. Thus, it can be understood as a so-called "region of interest (ROI)". In the literature, an ROI is often found by a given brain atlas that defines a number of brain regions, which corresponds to an anatomical approach. The present work introduces a semi-data-driven approach that is based on learning the charac…
Engaged managers are not workaholics: Evidence from a longitudinal personcentered analysis
2013
El objetivo de este estudio longitudinal entre directivos finlandeses ( n = 463) fue doble: en primer lugar investigar la relación entre el engagement (E) y la adicción al trabajo (AT) mediante enfoques centrados en la persona y en la variable y, en segundo lugar, explorar si (y cómo) se relacionan las experiencias de engagement y la adicción al trabajo con el cambio de trabajo durante el período de estudio. El análisis centrado en las variables, basado en modelos de ecuaciones estructurales, mostró que los factores latentes del engagement y la adicción al mismo no correlacionan entre sí, lo que sugiere que son constructos independien- tes. Los análisis centrados en la persona indicaron cua…
Trajectories of Perceived Employability and Their Associations With Well-Being at Work
2014
The first aim of this study was to identify trajectories of perceived employability (PE) with a longitudinal person-centered approach, accounting for both the level of PE and changes in PE. The second aim was to examine how the trajectories were related to well-being at work (i.e., vigor at work, job satisfaction, and job exhaustion) with a variable-centered approach. The data were collected in two Finnish universities (N = 926) during 2008–2010 with three measurement points. Growth Mixture Modeling identified four trajectories, which differed in level, stability, and change in PE across time: we established two trajectories with stable PE (88% of the participants), and two trajectories wi…
A person-centred approach to investigate the development trajectories of job-related affective well-being: A 10-year follow-up study
2011
The primary aim of this three-wave 10-year follow-up study was to investigate the intra-individual change trajectories of job-related affective well-being among Finnish managers (n = 402). Job-related affective well-being as indicated by anxiety, depression, comfort, and enthusiasm was measured in 1996, 1999, and 2006. The characteristics of the trajectories were sought from experienced career disruptions (i.e., periods of unemployment or lay-offs) and perceived job insecurity. The growth mixture modelling (GMM) revealed altogether three latent trajectories that differed from each other in their mean levels and regard to changes in job-related affective well-being over time: (1) high and im…
A longitudinal person-centred view on perceived employability : The role of job insecurity
2013
The primary aim of the present 1-year longitudinal study among university employees (N = 1314) was to investigate individual development of perceived employability (PE) by utilizing a person-centred approach. Thus, we identified latent classes of PE across 1 year based on growth mixture modelling. In addition, the latent classes were characterized by perceived job insecurity and the type of employment contract and its changes over the 1-year time period. The results showed four latent classes of PE that differed in the level and the direction of mean-level changes over time. These latent classes were: (1) stable relatively high PE (n = 641); (2) unstable decreasing PE (n = 45); (3) unstable…