Search results for "definitions"
showing 10 items of 32 documents
Body composition as a predictor of physical performance in older age : A ten- year follow-up of the Helsinki Birth Cohort Study
2018
Background: This study assessed how different measures of body composition predict physical performance ten years later among older adults. Methods: The participants were 1076 men and women aged 57 to 70 years. Body mass index (BMI), waist circumference, and body composition (bioelectrical impedance analysis) were measured at baseline and physical performance (Senior Fitness Test) ten years later. Linear regression analyses were adjusted for age, education, smoking, duration of the follow-up and physical activity. Results: Greater BMI, waist circumference, fat mass, and percent body fat were associated with poorer physical performance in both sexes (standardized regression coefficient [beta…
Patterns of objectively measured sedentary time in 10- to 12-year-old Belgian children: an observational study within the ENERGY-project
2017
Background This study examined the frequency of and differences in sedentary bouts of different durations and the total time spent in sedentary bouts on a weekday, a weekend day, during school hours, during after-school hours and in the evening period in a sample of 10- to 12-year-old Belgian children. Methods Accelerometer data were collected as part of the ENERGY-project in Belgium (n = 577, 10.9 ± 0.7 years, 53% girls) in 2011. Differences in total sedentary time, sedentary bouts of 2–5, 5–10, 10–20, 20–30 and ≥30 min and total time accumulated in those bouts were examined on a weekday, a weekend day, during school hours, during after-school hours and in the evening period, using multile…
Measurement Uncertainty of Harmonic Emission Indicators based on IEEE Std. 1459-2010
2020
The study presented in this paper is aimed at analyzing the measurement uncertainty impact on the evaluation of some power ratio parameters for harmonic emissions assessment based on IEEE Std. 1459-2010 apparent power decomposition. In addition to power factors for line utilization and harmonic pollution levels evaluation defined in the Standard, the study covers also some new parameters, which have been introduced by the authors as IEEE Std. 1459-2010 power quantities ratios. The measurement of the aforesaid parameters is implemented on a PC-based wattmeter, in order to investigate the measurement uncertainty impact on the evaluation of the power ratios. The obtained results show that, in …
The forgotten mathematical legacy of Peano
2019
International audience; The formulations that Peano gave to many mathematical notions at the end of the 19th century were so perfect and modern that they have become standard today. A formal language of logic that he created, enabled him to perceive mathematics with great precision and depth. He described mathematics axiomatically basing the reasoning exclusively on logical and set-theoretical primitive terms and properties, which was revolutionary at that time. Yet, numerous Peano’s contributions remain either unremembered or underestimated.
Fundamentals of photocatalysis: The role of the photocatalysts in heterogeneous photo-assisted reactions
2021
Abstract This chapter provides some general definitions of heterogeneous photocatalysis and evaluates its performance, which is influenced by the parameters most closely related to the properties of the solid material that acts as a photocatalyst. It also discusses aspects of heterogeneous photocatalytic reactions and explains the properties that influence photoactivity. Finally, the chapter examines thermodynamic and kinetic features, including mechanistic details and parameters to define the reaction rate and correlates them to the effects of the interaction of light with the photocatalyst surface and adsorption-desorption of species involved in heterogeneous photo-assisted reactions.
Rappresentazioni e territorio nelle dinamiche del turismo: il caso della Lonely Planet Sicily
2018
L’attuale dibattito sul riordino territoriale del Paese rende nuovamente centrale il concetto di territorio che, da sempre, in una prospettiva geografica pone problemi definitori. Esso può essere, infatti, oggetto di produzioni simboliche e (ri)semantizzazioni in grado di ridefinirlo e di creare specifiche modalità di interazione. A questo proposito, il presente lavoro intende proporre una riflessione su alcune dinamiche di produzione e riproduzione simbolica che interessano il concetto di territorio nel turismo, ambito in cui si può osservare una relazione diretta tra rappresentazione del territorio (intesa anche come narrazione) e possibilità d’azione. In particolare, attraverso il caso s…
L’historien et ses modèles
2010
Parler des modèles en histoire est une affaire délicate, car le mot recouvre des pratiques historiennes différentes depuis son apparition dans la discipline, après la dernière guerre mondiale. Pour une minorité d’historiens surtout spécialisés en histoire économique, il correspond à une vision nouvelle de la discipline qui tenterait d’intégrer certaines démarches mathématiques, en particulier aujourd’hui la théorie des jeux. Pour d’autres, en revanche, parler de modèles relèverait surtout d’une évolution du vocabulaire, sans impliquer de véritable mutation disciplinaire. Les historiens construisent et utilisent surtout des modèles explicatifs, voire palliatifs quand ils ont de trop grandes …
Computer game as a pragmatic concept : ideas, meanings, and culture
2020
This article discusses the ‘computer game’ as a pragmatic concept. A dual nature of the computer game as both a pragmatic idea and a pragmatic meaning is introduced. Practical meanings of the computer game correspond with the concrete effects that engaging with computer games produces in an individual. Practical ideas of the computer game correspond with the subjectively constituted conceptual families concerning the computer game’s assumed practical meaning. Individual computer games can be considered flat or round depending on the range of their practical meanings. Thus, the article contributes to the study of cultural objects by offering a framework for examining the evolution and existe…
Associations of muscular fitness and body composition in children
2021
Purpose: To examine the associations between muscular fitness (MF) and body composition. Method: MF was assessed with three tests of FitnessGram test battery. Total body fat percentage (BF%), abdominal fat percentage (AF%) and fat-free mass (FFM) were measured by dual-energy X-ray absorptiometry (DXA). The IOTF body mass index (BMI) cut-offs were used to define healthy weight, overweight, and obesity. Results: MF was inversely associated with BF% and AF%. The children in the moderate and high MF groups had significantly lower BF% and AF% compared with the children in the low MF group within the same BMI category. After adjusting for cardiorespiratory fitness (CRF), BMI and sex, the differen…
Polluting loads detection in power systems: a decision-making strategy based on nonactive power measurements
2010
In this paper a novel decision-making strategy is proposed for the detection of polluting loads in three-phase power systems. It makes use of simple indices, which are expressed as a function of some nonactive power quantities, previously proposed by the authors and derived from the approach of the IEEE Std. 1459–2000. The decision-making rules for the proposed strategy are presented and discussed, by means of some simulation tests.