Search results for " Regression"
showing 10 items of 1835 documents
Regression diagnostics applied in kinetic data processing: outlier recognition and robust weighting procedures
2010
An efficient protocol, based on advanced statistical diagnostics and robust fitting techniques applied to the least-squares processing of kinetic data of chemical reactions, is here presented and discussed. The procedure, which is aimed at obtaining highly accurate estimation of the fitting parameters, consists in the identification of the outliers that remarkably impair the fitting by means of the so called 'leverage analysis' and some related diagnostics, allowing the elimination of the actually aberrant observations from the data set and/or their robust weighting to inhibit the negative effects induced on the data fitting and to reduce the bias introduced into the parameter estimates. It…
Predicting the 2000‐m Rowing Ergometer Performance from Anthropometric, Maximal Oxygen Uptake and 60‐s Mean Power Variables in National Level Young R…
2020
Abstract Many studies reported various relationships between 2000-m rowing performance and anthropometric as well as metabolic variables, however, little is known about 60-s mean power in elite youth athletes. The aim of this study was to develop different regression models to predict 2000-m rowing indoor performance time (t2000) using anthropometric variables, maximal oxygen uptake (VO2max) and mean power established during a 60-s all-out test (W60) in national elite youth rowers. Fifteen youth male Italian rowers (age: 15.7 ± 2.0 years; body height: 176.0 ± 8.0 cm; body mass: 71.2 ± 10.0 kg) performed an incremental maximal test, a 60-s all-out test and a 2000-m race simulation using a Co…
Trait Hedonism and the Distribution of Savoring and Positive Emotion States in Everyday Life.
2022
International audience; The present study aimed at (1) identifying the emotion regulation processes that can explain the trait hedonism positive emotions relationship, and (2) determining whether this relationship varies according to which part of the distribution of positive emotions is considered. To this end, the intensity of the positive emotions felt by 84 adult participants, and the intensity of their engagement in savoring, were assessed twice a day over a month period, using an Experience Sampling Method. Participants’ distributions of these variables were then related to their level of trait hedonism, assessed with a common questionnaire. Results suggested that, as expected, the tr…
Dualismo tra occupati: evidenze empiriche per il caso Italiano
2005
Questo articolo testa l'esistenza di dualismo dal punto di vista salariale tra lavoratori, applicando un modello di mistura di regressioni. I risultati mostrano differenze di rendimento elevate tra lavoratori a settori "primari" e "secondari".
Infrastructural and Human Factors Affecting Safety Outcomes of Cyclists
2018
The increasing number of registered road crashes involving cyclists during the last decade, and the high proportion of road crashes resulting in severe injuries and fatalities among cyclists constitutes a global issue for community health, urban development, and sustainability. Nowadays, the incidence of many risk factors for road crashes of cyclists remains largely unexplained. Given the importance of this issue, the present study has been conducted with the aim of determining relationships between infrastructural, human factors and safety outcomes of cyclists. Objectives: This study aimed, first, to examine the relationship between key infrastructural and human factors present in cycling,…
Variazioni di carbonio organico nei suoli italiani dal 1979 al 2008
2010
I suoli contengono circa tre volte la quantità di carbonio disponibile a livello mondiale nella vegetazione e circa il doppio di quella presente in atmosfera. Tuttavia il carbonio organico del suolo (SOC) si è ridotto in molte aree, mentre è stato rilevato un aumento della CO2 atmosferica. Ricerche recenti hanno dimostrato che sono stati i cambiamenti di uso e gestione del suolo a provocare le maggiori perdite di SOC nel recente passato, piuttosto che le più alte temperature e i cambiamenti delle precipitazioni conseguenti il cambiamento climatico. Lo scopo principale di questo lavoro è quello di stimare le variazioni del contenuto di carbonio organico dei suoli (carbon stock, CS) in Italia…
Analysis of a database to predict the result of allergy testing in vivo in patients with chronic nasal symptoms.
2014
Background This article uses the logistic regression model for diagnostic decision making in patients with chronic nasal symptoms. We studied the ability of the logistic regression model, obtained by the evaluation of a database, to detect patients with positive allergy skin-prick test (SPT) and patients with negative SPT. The model developed was validated using the data set obtained from another medical institution. Methods The analysis was performed using a database obtained from a questionnaire administered to the patients with nasal symptoms containing personal data, clinical data, and results of allergy testing (SPT). All variables found to be significantly different between patients w…
Adsorption of anionic dyes onto natural, thermally and chemically modified smectite clays
2014
Abstract The aim of this study was to determine the adsorption capacity of the smectite clays (from the overburden of the lignite deposit in Belchatow) for two anionic dyes, i.e. Reactive Blue 81 (RB-81) and Direct Blue 74 (DB-74). Additionally, the influence of the thermal and chemical (acid and alkali) clay modifications on the amount of bonded dyes was investigated. The adsorption capacity of the clay (natural and modified) was different for studied dyes and depended on the initial concentration and modification type. All the modified clays adsorbed the dyes at pH>pHPZC as the negatively charged surfaces of their particles (in accordance with the formula: AOH ↔ AO- + H+) prevented the…
Statistical analysis of the relation between metallic microstructures and mechanical properties
2020
This thesis aims at the development of physical relations between the intricate 3D features of metallic microstructures and the mechanical properties of the material. For understanding which are the microstructural determinants of the resultingmechanical behaviour of metals, a deep quantitative characterisation of the microstructure is needed. The main steps of quantitative characterisation of the microstructures are: identification of the phases distribution and their chemical composition, study of the microstructure morphology (geometrical arrangement of grains, grain boundaries, grain orientations, grain size and grain shape). An accurate description of the microstructure features enrich…
Hints of latent drivers investigating university student performance
2018
Job market, nowadays, asks for higher and higher skills and competences. Therefore, also the measurement and assessment of the university students performance are crucial issues for policy makers. Although the scientific literature provides several papers investigating the main determinants of university student performance, often results are very different, and they seem to hold just in very specific contexts. This paper aims to contribute to the international literature, focusing on the role of student specific characteristics, supporting the idea that unobservable variables (such as motivation, aptitudes or abilities) should be more investigated.