Search results for " Regression"
showing 10 items of 1835 documents
Predicting Earthquake-Induced Landslides by Using a Stochastic Modeling Approach: A Case Study of the 2001 El Salvador Coseismic Landslides
2023
In January and February 2001, El Salvador was hit by two strong earthquakes that triggered thousands of landslides, causing 1259 fatalities and extensive damage. The analysis of aerial and SPOT-4 satellite images allowed us to map 6491 coseismic landslides, mainly debris slides and flows that occurred in volcanic epiclastites and pyroclastites. Four different multivariate adaptive regression splines (MARS) models were produced using different predictors and landslide inventories which contain slope failures triggered by an extreme rainfall event in 2009 and those induced by the earthquakes of 2001. In a predictive analysis, three validation scenarios were employed: the first and the second …
Pain and clinical findings in the low back: a study of industrial employees with 5-, 10-, and 28-year follow-ups.
2009
Little is known about the relationships of clinical findings in the low back with low back pain (LBP) in the normal working population. We studied whether physiotherapist's findings in the low back were associated with local and radiating LBP among a cohort (n=902) of employees in the engineering industry. A systematic non-proportional sample was drawn in strata by age, gender, and occupational class. The non-proportionality aimed at increasing sample size in smaller strata. Physiotherapists performed the straight-leg raising test (SRL), and made assessments of the fingertip-to-floor distance and pain in palpation of the lumbar interspinous spaces. The variables on pain at the interspinous …
Associations of physical performance and physical activity with mental well-being in middle-aged women
2021
Abstract Background To investigate whether physical performance is independently of physical activity (PA) associated with positive and negative dimensions of mental well-being in middle-aged women. Methods Data were drawn from the Estrogenic Regulation of Muscle Apoptosis (ERMA) study in which women 47 to 55 years were randomly selected from the Finnish National Registry. They (n = 909) participated in measurements of physical performance (handgrip force, knee extension force, vertical jumping height, maximal walking speed, and six-minute walking distance). Both mental well-being (the Centre for Epidemiologic Studies Depression Scale, the International Positive and Negative Affect Schedule…
Noise Reduction and Gap Filling of fAPAR Time Series Using an Adapted Local Regression Filter
2014
Time series of remotely sensed data are an important source of information for understanding land cover dynamics. In particular, the fraction of absorbed photosynthetic active radiation (fAPAR) is a key variable in the assessment of vegetation primary production over time. However, the fAPAR series derived from polar orbit satellites are not continuous and consistent in space and time. Filtering methods are thus required to fill in gaps and produce high-quality time series. This study proposes an adapted (iteratively reweighted) local regression filter (LOESS) and performs a benchmarking intercomparison with four popular and generally applicable smoothing methods: Double Logistic (DLOG), sm…
Smoothed score confidence interval for the breakpoint in segmented regression
2012
For the breakpoint parameter in segmented regression we consider confidence intervals based on the score statistic. Due to unsmoothness of the score, we propose to build the confidence intervals using its smoothed version under proper shape restrictions. Some simulations are presented to assess the finite sample performance of the proposed approach.
Testing for a breakpoint in segmented regression: a pseudo score approach
2011
To overcome the well known oddities in testing for the existence of a breakpoint in segmented regression models, we discuss a novel approach based on the Pearson X2 statistic which can be understood as an approximation of the Score statistic. We describe the method and present results from some simulations.
Wiener-Granger Causality in Network Physiology with Applications to Cardiovascular Control and Neuroscience
2016
Since the operative definition given by C. W. J. Granger of an idea expressed by N. Wiener, the Wiener–Granger causality (WGC) has been one of the most relevant concepts exploited by modern time series analysis. Indeed, in networks formed by multiple components, working according to the notion of segregation and interacting with each other according to the principle of integration, inferring causality has opened a window on the effective connectivity of the network and has linked experimental evidences to functions and mechanisms. This tutorial reviews predictability improvement, information-based and frequency domain methods for inferring WGC among physiological processes from multivariate…
Prenatal air pollution exposure and growth and cardio-metabolic risk in preschoolers
2020
Objectives: We investigated the association between outdoor air pollutants exposure in the first trimester of pregnancy, and growth and cardio-metabolic risk at four years of age, and evaluated the mediating role of birth weight. Methods: We included mother-child pairs (N = 1,724) from the Spanish INMA birth cohort established in 2003-2008. First trimester of pregnancy nitrogen dioxide (NO2) and fine particles (PM2.5) exposure levels were estimated. Height, weight, waist circumference, blood pressure, and lipids were measured at four years of age. Body mass index (BMI) trajectories from birth to four years were identified. Results: Increased PM2.5 exposure in the first trimester of pregnanc…
Customer Value Framework and Recommendation Intention: The Moderating Role of Customer Characteristics in an Online Travel Community
2019
The aim of this study was to develop and test a model that examined the interactions among the customer value framework, recommendation intention and customer characteristics in an online travel community (OTC). Data were obtained using Amazon Mechanical Turk from 251 members of an OTC as a sample. The partial least squares method was used to analyse the data. We found that all the variables of the customer value framework, including functional value, hedonic value and social value, were positively related to recommendation intention. In addition, using multi-group analyses, the study found differences between how different customer segments perceive each of the value dimensions and their e…
Differential effects of perceptions of equal, favourable and unfavourable autonomy support on educational and well-being outcomes
2019
Abstract In this study, we examined whether high-school students experienced optimal educational and well-being outcomes when they perceived that they and their classmates received an equal, rather than unequal, and high amount of autonomy support from teachers. In a prospective study that aimed to predict academic grades and well-being outcomes, surface analyses of polynomial regression equations pointed that perceptions of equal autonomy support were the most optimal in terms of yielding highest levels of need satisfaction, autonomous forms of motivation and happiness with math courses. Additionally, in accordance with tenets of self-determination theory, we demonstrated that effects asso…