Search results for " cluster analysis."
showing 10 items of 70 documents
Prácticas de alto rendimiento : un enfoque configuracional aplicado al caso español
2008
Roberto.Luna@uv.es Joaquin.Camps@uv.es El principal objetivo de esta investigación es analizar diferentes configuraciones de prácticas de recursos humanos (RH) que se dan en una muestra de 183 empresas españolas. A continuación se relacionan estas configuraciones con las estrategias competitivas de las empresas con el fin de validar la estructura configuracional obtenida. Los resultados muestran tres tipos de configuraciones. La primera, empresas con prácticas de alto rendimiento (PAR) (37,5%), se caracteriza por un intenso y generalizado uso de dichas prácticas. La segunda, empresas desarrollando PAR (46,4%), se caracteriza por el uso de una amplia gama de PAR, pero con una limitada aplica…
Cluster analysis of clinical data reveals three pediatric eosinophilic gastrointestinal disorder phenotypes
2022
Primary eosinophilic gastrointestinal disorders (EGIDs) are a spectrum of emerging inflammatory diseases, which may involve any part of the gastrointestinal (GI) tract and lead to a pathological eosinophilic mucosal infiltration.1,2 Based on the anatomical site of the eosinophil inflammation, EGIDs are classified into eosinophilic esophagitis (EoE) and nonesophageal EGIDs.This study aimed to characterize EGIDs heterogeneity by performing cluster analysis on a cohort of children and adolescents followed at the Pediatric Center for Eosinophilic Gastrointestinal Disorders (CPED) in Pavia, Italy, using an extensive pediatric primary care database from our University Hospital
Predicting lorawan behavior. How machine learning can help
2020
Large scale deployments of Internet of Things (IoT) networks are becoming reality. From a technology perspective, a lot of information related to device parameters, channel states, network and application data are stored in databases and can be used for an extensive analysis to improve the functionality of IoT systems in terms of network performance and user services. LoRaWAN (Long Range Wide Area Network) is one of the emerging IoT technologies, with a simple protocol based on LoRa modulation. In this work, we discuss how machine learning approaches can be used to improve network performance (and if and how they can help). To this aim, we describe a methodology to process LoRaWAN packets a…
Exploratory approach for network behavior clustering in LoRaWAN
2021
AbstractThe interest in the Internet of Things (IoT) is increasing both as for research and market perspectives. Worldwide, we are witnessing the deployment of several IoT networks for different applications, spanning from home automation to smart cities. The majority of these IoT deployments were quickly set up with the aim of providing connectivity without deeply engineering the infrastructure to optimize the network efficiency and scalability. The interest is now moving towards the analysis of the behavior of such systems in order to characterize and improve their functionality. In these IoT systems, many data related to device and human interactions are stored in databases, as well as I…
Biodiversità in alcune specie del genere Mentha nel territorio dei Monti Nebrodi (Sicilia N-W).
2008
In Nebrodi Mountains (N-E Sicily), the genus Mentha is represented by an high number of species, in many cases typical of humid and subhumid environments. This work was addressed to investigate about the biomorphological traits of various accessions belonging to 3 Mentha species collected in the Nebrodi highlands, namely 22 accessions of Mentha spicata, 12 of Mentha suaveolens and 13 of Mentha aquatica. Plant material was picked up starting from the early spring 2007, from different sites as in altitude and in pedological and climatic traits, that were distributed over an area of 200.000 ha approx.. Later on, all collected plant individuals were transplanted in a collection field, appositel…
A new OLS-based procedure for clusterwise linear regression
2009
Data heterogeneity, within a (linear) regression framework, often suggests the use of a Clusterwise Linear Regression (CLR) procedure, which implies, among other things, the estimate of the appropriate number of clusters as well as the cluster membership of each unit. The approaches to the estimation of a CLR model are essentially based on the Ordinary Least Square (OLS) criterion or the likelihood criterion. In this paper, in a context of OLS approach, we propose an estimation of the model making use of an algorithm based on a threshold criterion for the determination coefficient of each cluster, to identify the appropriate number of clusters, and of a modified Spath's algorithm, to estima…
Long-Term Calorie Restriction Enhances Cellular Quality-Control Processes in Human Skeletal Muscle
2015
Calorie restriction (CR) retards aging, acts as a hormetic intervention, and increases serum corticosterone and HSP70 expression in rodents. However, less is known regarding the effects of CR on these factors in humans. Serum cortisol and molecular chaperones and autophagic proteins were measured in the skeletal muscle of subjects on CR diets for 3-15 years and in control volunteers. Serum cortisol was higher in the CR group than in age-matched sedentary and endurance athlete groups (15.6 ± 4.6 ng/dl versus 12.3 ± 3.9 ng/dl and 11.2 ± 2.7 ng/dl, respectively; p ≤ 0.001). HSP70, Grp78, beclin-1, and LC3 mRNA and/or protein levels were higher in the skeletal muscle of the CR group compared to…
In-hospital death and adverse clinical events in elderly patients according to disease clustering: The REPOSI study
2010
OBJECTIVE: The aim of the study was to recognize clusters of diseases among hospitalized elderly and to identify groups of patients at risk of in-hospital death and adverse clinical events according to disease clustering. METHOD: This was a cross-sectional study conducted in 38 internal medicine and geriatric wards in Italy participating in the Registro Politerapie SIMI (REPOSI) study during 2008. The subjects were 1,332 inpatients aged 65 years or older. Clusters of diseases (i.e., two or more co-occurrent diseases) were identified using the odds ratios (OR) for the associations between pairs of conditions, followed by cluster analysis. Logistic regression models were used to evaluate the …
Disentangling the Association of Hydroxychloroquine Treatment with Mortality in Covid-19 Hospitalized Patients through Hierarchical Clustering
2021
The efficacy of hydroxychloroquine (HCQ) in treating SARS-CoV-2 infection is harshly debated, with observational and experimental studies reporting contrasting results. To clarify the role of HCQ in Covid-19 patients, we carried out a retrospective observational study of 4,396 unselected patients hospitalized for Covid-19 in Italy (February–May 2020). Patients’ characteristics were collected at entry, including age, sex, obesity, smoking status, blood parameters, history of diabetes, cancer, cardiovascular and chronic pulmonary diseases, and medications in use. These were used to identify subtypes of patients with similar characteristics through hierarchical clustering based on Gower distan…
Effectiveness of a Psychosocial Care Quality Improvement Strategy to Address Quality of Life in Patients with Cancer: The HuCare2 Stepped-Wedge Clust…
2021
Key Points Question Does an implementation strategy integrating psychosocial care into cancer centers improve at least 1 of 2 domains (emotional or social function) of health-related quality of life? Findings This stepped-wedge cluster randomized clinical trial included 762 patients with cancer at high risk for reduced quality of life. Health-related quality of life score improved from baseline to 3 months among participants in the Humanization in Cancer Care Quality Improvement Strategy arm vs the usual care arm, showing a statistically significant difference for emotional function, but not for social function. Meaning This study suggests the use of an implementation strategy aiming to pro…