Search results for " regression [Classificació AMS]"

Penalized regression and clustering in high-dimensional data

The main goal of this Thesis is to describe numerous statistical techniques that deal with high-dimensional genomic data. The Thesis begins with a review of the literature on penalized regression models, with particular attention to least absolute shrinkage and selection operator (LASSO) or L1-penalty methods. L1 logistic/multinomial regression models are used for variable selection and discriminant analysis with a binary/categorical response variable. The Thesis discusses and compares several methods that are commonly utilized in genetics, and introduces new strategies to select markers according to their informative content and to discriminate clusters by offering reduced panels for popul…

Community Perilaku Masyarakat dalam Mengelola Sampah Rumah Tangga di Distrik Manokwari Timur Kabupaten Manokwari

2020

This study aims to (1) determine the behavior of the community in managing household waste in Manokwari Timur District, Manokwari Regency, (2) to analyze the factors that influence people's behavior in managing household waste. This research was conducted in Manokwari Regency, West Papua Province. The research method used is descriptive quantitative with data analysis using multiple regression analysis. The results showed: (1) The overall behavior of the community in managing household waste in East Manokwari District (65.5%) was in the sufficiently supportive category. Meanwhile, as many as 34.9% are in the unsupported category, (2) The results of multiple linear regression analysis show t…

How well does brand personality predict brand choice ?

2004

The research proposes a methodology allowing both the construction of a brand personality scale and the test of the ability of the scale to predict brand choice. A brand personality scale is developed and tested via exploratory and confirmatory analyses. A brand personality structure composed of 12 facets is uncovered and allows clearly differentiating brands belonging to the same market. Predictive power of the scale is then tested using binary regression models.

Prediction of BOD5 content of the inflow to the treatment plant using different methods of black box - the case study

2020

The publication presents the possibility of modeling in a 1 d advance of the content of organic compounds in the influent wastewater to the treatment plant, where the content of these compounds is determined by both the biochemical and chemical oxygen demand. To predict the quality of the wastewater at the inflow a set of indicators where used to make measurements on a daily basis. In order to develop statistical models 3 methods where used, namely: multivariate adaptive regression splines (MARS), boosted trees (BT), and genetic programming (GP). The carried-out calculations showed that, to calculate the BOD5 there can only be used models developed on the basis of the value of daily wastewa…

Assessment of Gully Erosion Susceptibility Using Multivariate Adaptive Regression Splines and Accounting for Terrain Connectivity

2017

In this work, we assessed gully erosion susceptibility in two adjacent cultivated catchments of Sicily (Italy) by employing multivariate adaptive regression splines (MARS) and a set of geo-environmental variables. To explore the influence of hydrological connectivity on gully occurrence we measured the changes of performance occurred when adding one by one nine predictors reflecting terrain connectivity to a base model that included contributing area and slope gradient. Receiver operating characteristic (ROC) curves and the area under the ROC curve (AUC) were used to evaluate models performance. Gully predictive models were trained in both the catchments and submitted to internal (in the ca…

Organizational Cooperation and Knowledge Management in Research and Development Organizations

2017

Organizational Cooperation (OC) is a current concept that responds to the growing interdependence among individuals and teams. Likewise, Knowledge Management (KM) accompanies specialization in all sectors of human activity. Most KM processes are cooperation-intensive, and the way both constructs relate to each other is relevant in understanding organizations and promoting performance. The present paper focuses on that relationship. The Organizational Cooperation Questionnaire (ORCOQ) and the Short form of the Knowledge Management Questionnaire (KMQ-SF) were applied to 639 members of research and development (R&D) organizations (Universities and Research Institutes). Descriptive, correla…

An integrated analysis of land market in an inland area of Sicily

2013

In this study a land market analysis of the 22,000 hectares covered by Corleone town area for the 2007-2012 period was carried out. Data on 372 sales agreements concerning agricultural and building land were directly collected from notaries' offices. Over 50% of land sales concerned land areas below 0.50 hectares, whereas just 1% of the overall land sold was larger than 10 hectares. Nearly 75% of sample observations were represented by land sales smaller than 1 hectare. The average land area per purchase was just over 1 hectare. The overall money exchanged in the whole period amounted to nearly 6 million euro, with an average price per sale equal to 16,339.45 (sic), and an average unitary p…

Quantile Regression Coefficients Modeling: a Penalized Approach

2018

Modeling quantile regression coefficients functions permits describing the coefficients of a quantile regression model as parametric functions of the order of the quantile. This approach has numerous advantages over standard quantile regression, in which different quantiles are estimated one at the time: it facilitates estimation and inference, improves the interpretation of the results, and is statistically efficient. On the other hand, it poses new challenges in terms of model selection. We describe a penalized approach that can be used to identify a parsimonious model that can fit the data well. We describe the method, and analyze the dataset that motivated the present paper. The propose…

2019

Introduction: Despite substantial interest in the development of health behaviors, there is limited research that has examined the longitudinal relationship between physical activity (PA) and smoking trajectories from youth to adulthood in a Finnish population. This study aimed to identify trajectories of smoking and PA for males and females, and study the relationship between these trajectories from youth to adulthood. Methods: Latent profile analysis (LPA) was used to identify trajectories of smoking and PA separately for males and females among 3355 Finnish adults (52.1% females). Participants’ smoking and PA were assessed five to eight times over a 31-year period (3–18 years old at the …

Comparison of different segmentation approaches without using gold standard. Application to the estimation of the left ventricle ejection fraction fr…

2011

International audience; A statistical method is proposed to compare several estimates of a relevant clinical parameter when no gold standard is available. The method is illustrated by considering the left ventricle ejection fraction derived from cardiac magnetic resonance images and computed using seven approaches with different degrees of automation. The proposed method did not use any a priori regarding with the reliability of each method and its degree of automation. The results showed that the most accurate estimates of the ejection fraction were obtained using manual segmentations, followed by the semiautomatic methods, while the methods with the least user input yielded the least accu…