Search results for "regression"
showing 10 items of 2619 documents
Non-linear System Identification with Composite Relevance Vector Machines
2007
Nonlinear system identification based on relevance vector machines (RVMs) has been traditionally addressed by stacking the input and/or output regressors and then performing standard RVM regression. This letter introduces a full family of composite kernels in order to integrate the input and output information in the mapping function efficiently and hence generalize the standard approach. An improved trade-off between accuracy and sparsity is obtained in several benchmark problems. Also, the RVM yields confidence intervals for the predictions, and it is less sensitive to free parameter selection. Teoría de la Señal y Comunicaciones
Discrete Time Signal Processing Framework with Support Vector Machines
2007
Digital signal processing (DSP) of time series using SVM has been addressed in the literature with a straightforward application of the SVM kernel regression, but the assumption of independently distributed samples in regression models is not fulfilled by a time-series problem. Therefore, a new branch of SVM algorithms has to be developed for the advantageous application of SVM concepts when we process data with underlying time-series structure. In this chapter, we summarize our past, present, and future proposal for the SVM-DSP frame-work, which consists of several principles for creating linear and nonlinear SVM algorithms devoted to DSP problems. First, the statement of linear signal mod…
Relative evaluation of regression tools for urban area electrical energy demand forecasting
2019
Abstract Load forecasting is the most fundamental application in Smart-Grid, which provides essential input to Demand Response, Topology Optimization and Abnormally Detection, facilitating the integration of intermittent clean energy sources. In this work, several regression tools are analyzed using larger datasets for urban area electrical load forecasting. The regression tools which are used are Random Forest Regressor, k-Nearest Neighbour Regressor and Linear Regressor. This work explores the use of regression tool for regional electric load forecasting by correlating lower distinctive categorical level (season, day of the week) and weather parameters. The regression analysis has been do…
Determination of the energetic value of fruit and milk-based beverages through partial-least-squares attenuated total reflectance-Fourier transform i…
2005
Abstract The estimation of important nutritional parameters, such as carbohydrates content and energetic value (calories) in commercially available fruit juice and flavour milk shakes has been made by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) using a partial-least-square (PLS) calibration approach. A highly heterogeneous population of 65 samples obtained from the Spanish market, covering fruit juices, flavour milk shakes and milk-added fruit juices was used. The spectral range and the size of the calibration set for building the PLS model have been evaluated. Considering a calibration set comprised of 27 samples, selected via hierarchical cluster analys…
Associations between recently diagnosed conditions and hospitalization due to COVID-19 in patients aged 50 years and older– A SHARE-based analysis
2021
Abstract Background Only a few studies have been carried out with a large sample size on the relationship between chronic conditions and hospitalization for coronavirus disease 2019 (COVID-19), and there is no research examining recently diagnosed conditions. Our purpose was to evaluate this association in a large sample including the older population from Europe and Israel. Method Data from the Survey of Health, Ageing and Retirement in Europe COVID-19 Survey, a representative survey of individuals aged 50 or older residing in 27 European countries and Israel, were retrieved. Associations between recently diagnosed chronic conditions (ie, conditions detected over the last 3 years) (exposur…
Residential location and youth unemployment: The economic geography of school-to-work transitions
2003
In response to increased international policy attention to youth unemployment this study investigates post-secondary school transitions of school leavers. Multinomial logit models are estimated for male and female German youth. The models control for individual, parent, and household characteristics, for those of the youth’s region of residence and local labor markets. The findings suggest that immigrant youth has particularly low participation rates in continued education, and that youth unemployment is centered in high unemployment states and metropolitan areas. More generous academic benefit policies seem to be correlated with increased academic enrollment, and men’s transitions to the m…
Estuarine sediment quality assessment by Fourier-transform infrared spectroscopy
2010
Partial least squares Fourier-transform infrared (PLS-FTIR) models were developed for the quality assessment of estuarine sediments through the evaluation of several physico-chemical parameters. Models were based on the chemometric treatment of attenuated total reflection (ATR) spectra directly obtained from samples previously lyophilized and sieved through a lower than 63 μm grid. Spectra were scanned from 3997 to 523 cm-1, averaging 36 scans per spectrum with a nominal resolution of 8 cm-1. Models were built using reference data obtained for sediment samples collected from Ria de Arousa estuary. Hierarchical cluster classification of sediment ATR spectra was employed for the establishment…
Comparative modelling study on enantioresolution of structurally unrelated compounds with amylose-based chiral stationary phases in reversed phase li…
2020
[EN] Polysaccharide-based chiral stationary phases (CSPs) are the most used chiral selectors in HPLC. These CSPs can be used in normal, polar organic and aqueous-organic mobile phases. However, normal and polar organic mobile phases are not adequate for chiral separation of polar compounds, for the analysis of aqueous samples and for MS detection. In these situations, reversed phase conditions, without the usual non-volatile additives incompatible with MS detection, are preferable. Moreover, in most of the reported chiral chromatographic methods, retention is too large for routine work. In this paper, the chiral separation of 53 structurally unrelated compounds is studied using three commer…
Estimating oxygen consumption from heart rate and heart rate variability without individual calibration
2011
Heart rate (HR) as an estimator of oxygen consumption (VO(2) ) usually requires HR to be individually calibrated in a separate test. This study examined the validity of a new HR - and HR variability-based method (Firstbeat PRO heartbeat analysis software) in the estimation of VO(2) in real-life tasks. The method takes into account the respiration rate determined from HR variability and the differences in the on/off dynamics of HR and VO(2) , and no calibration tests are needed. Ten men and nine women performed 25 tasks representing different types of daily activities. Portable devices were used to measure R-to-R intervals (ECG), VO(2) and respiration rate. In pooled regression analysis, the…
Dental expenditure and catastrophic dental expenditure in Eastern Saudi Arabia: Pattern and associated factors
2019
Background Dental services have one of the highest expenses among health services. The aims of the study were to assess (1) dental expenditure (DE), (2) catastrophic dental expenditure (CDE), (3) dental services payment and (4) factors associated with DE and CDE. Material and methods A cross sectional study was conducted in 2018 in Saudi Arabia. Using convenience sample, participants were recruited from governmental and private dental clinics/hospitals. A questionnaire assessed (a) personal information, (b) dental background: payment methods, type of clinics visited, perceived oral health status, frequency of pain and (c) payment for dental services received. The number of remaining teeth w…