Search results for "viat"
showing 10 items of 562 documents
Bolton ratios in Portuguese subjects among different malocclusion groups
2018
Background Several methods have been described to estimate inter-arch tooth size relationship, such as Bolton's ratios. The aims of this study were to verify the validity of Bolton indexes in a sample of untreated Portuguese subjects based on Angle classification and to evaluate the gender difference. Material and Methods 168 pre-treatment dental casts of orthodontics Portuguese subjects (59 males and 109 females) with different occlusions were used, which were selected randomly from 541 consecutively treated orthodontic patients. The mesiodistal widths from first molar to first molar were measured on each pre-treatment cast to the nearest 0.01 mm using digital caliper, and Bolton's anterio…
A meta-analysis of the validity of FFQ targeted to adolescents.
2015
AbstractObjectiveThe present work is aimed at meta-analysing validity studies of FFQ for adolescents, to investigate their overall accuracy and variables that can affect it negatively.DesignA meta-analysis of sixteen original articles was performed within the ASSO Project (Adolescents and Surveillance System in the Obesity prevention).SettingThe articles assessed the validity of FFQ for adolescents, compared with food records or 24 h recalls, with regard to energy and nutrient intakes.SubjectsPearson’s or Spearman’s correlation coefficients, means/standard deviations, kappa agreement, percentiles and mean differences/limits of agreement (Bland–Altman method) were extracted. Pooled estimates…
Statistical characterization of deviations from planned flight trajectories in air traffic management
2016
Understanding the relation between planned and realized flight trajectories and the determinants of flight deviations is of great importance in air traffic management. In this paper we perform an in depth investigation of the statistical properties of planned and realized air traffic on the German airspace during a 28 day periods, corresponding to an AIRAC cycle. We find that realized trajectories are on average shorter than planned ones and this effect is stronger during night-time than daytime. Flights are more frequently deviated close to the departure airport and at a relatively large angle to destination. Moreover, the probability of a deviation is higher in low traffic phases. All the…
Functional test measures as risk indicators for low back pain among fixed-wing military pilots.
2015
Purpose The purpose of this study was to find out the risk value of functional fitness test (FFT) results for low back pain (LBP) among fixed-wing military pilots. Methods A total of 104 male military pilots were recruited for this study. The study was conducted with a self-administered questionnaire and FFT. The functional tests were performed in the beginning of study (baseline). The questionnaire was carried out at the baseline and 5 years later. Results The isometric low back endurance test result was associated with physical activity-related LBP experienced 5 years later. Demographic information was not associated with LBP. The prevalence of overall LBP was 71% and the flight-related L…
Sleep, alertness and alertness management among commercial airline pilots on short-haul and long-haul flights
2016
Item does not contain fulltext Airline pilots' sleep and on-duty alertness are important focus areas in commercial aviation. Until now, studies pertaining to this topic have mainly focused on specific characteristics of flights and thus a comprehensive picture of the matter is not well established. In addition, research knowledge of what airline pilots actually do to maintain their alertness while being on duty is scarce. To address these gaps in research knowledge, we conducted a field study on a representative sample of the airline pilots of a medium-sized airline. The sample consisted of 90 pilots, of whom 30 flew long-haul (LH) routes, 30 short-haul (SH) routes, and 30 flew both. A tota…
The emissions reduction potential of substituting short-haul flights with non-high-speed rail (NHSR): The case of Finland
2021
Abstract Replacing short-haul flights with high-speed rail (HSR) has been widely discussed as one solution to mitigate the climate change impacts of aviation. However, although HSR can provide travel times similar to those provided by short-haul flights, and at lower emission levels, it also requires considerable investments in time and infrastructure to build. Instead, this study considers the feasibility of replacing short-haul flights with existing non-high-speed rail (NHSR). Our study is based in Finland, a country that has an extensive route network of short-haul flights but does not possess any HSR. We compared all 16 city pairs for which short-haul flights are offered with existing N…
Fatigue Monitoring Tool for Airline Operators (FMT)
2017
Abstract A Fatigue Monitoring Tool (FMT) model was constructed for an operational airline in order to manage the fatigue levels of their crews in accordance with Fatigue Risk Management System (FRMS) practices. This article describes the implementation of the Fatigue Monitoring Tool model and the airline’s aims to put the recent scientific findings on aviation fatigue into practical use. The model consists of proxy points allotted to various duties and rest periods.
The social acceptance of airport expansion scenarios: A factorial survey experiment
2020
Abstract Against the background of growing aviation and protests against air traffic in many countries, we employ a factorial survey experiment to examine the social acceptance of airport expansion scenarios in two European cities located near the international airports of Frankfurt (Germany) and Zurich (Switzerland), respectively. In our experiment, respondents evaluated short descriptions of airport expansion scenarios that varied in several impact attributes. The experiment helps to disentangle to what extent environmental impacts (aircraft noise), economic impacts (job creation), participatory justice aspects (participation opportunities), and distributive justice aspects (noise distrib…
Repeatability of in-vitro optical quality measurements of intraocular lenses with a deflectometry technique effect of the toricity
2018
Aim To evaluate the repeatability of an optical device for measuring the Zernike coefficients of toric intraocular lenses (IOLs) and assess whether its toricity has any impact in its repeatability. Methods An experienced technician used the NIMO TR1504 to measure the Zernike coefficients 30 times for an aperture of 4.50 mm for all lenses included. The IOLs included were divided into two group: toric and non-toric ones. The cylindrical powers of the toric lenses included in the present study were 1.00, 1.50, 2.25, 3.00 and 3.75 D. Finally, the repeatability of the NIMO TR1504 was described in terms of within subject standard deviation (Sw) and repeatability limit. Results The Sw was smaller …
El papel de los servicios públicos en el desarrollo de áreas rurales: una perspectiva comparada
2010
El objetivo de la presente tesis es determinar el impacto que tienen los servicios y equipamientos públicos educativos y sanitarios elementales en los procesos de desarrollo rural. Ante la complejidad de dicho trabajo, y con el fin de conseguir unos resultados significativos y capaces de tomarse como posibles referencias, el estudio práctico se lleva a cabo en dos zonas rurales con marcados contrastes territoriales internos, pero de organización similar en cuanto a aspectos económicos, demográficos, políticos, etc. Así, por un lado se elige como área de estudio la Provincia de Valencia (Comunidad Valenciana, España); y por otro, se toma el Departamento de La Manche (Región de Baja Normandía…