Search results for "HTI"

Genetic and environmental effects on body mass index during adolescence: a prospective study among Finnish twins

2009

Objective: To study genetic and environmental factors affecting body mass index (BMI) and BMI phenotypic correlations across adolescence. Design: Prospective, population-based, twin cohort study. Participants and methods: We used twin modeling in 2413 monozygotic and same-sex and opposite-sex dizygotic Finnish twin pairs born in 1983–1987 and assessed using self-report questionnaires at 11–12, 14 and 17 years of age. Results: Heritability of BMI was estimated to be 0.58–0.69 among 11–12- and 14-year-old boys and girls, 0.83 among 17-year-old boys and 0.74 among 17-year-old girls. Common environmental effects shared by siblings were 0.15–0.24 among 11–12- and 14-year-old boys and girls but n…

Arm swing during skating at different skiing speeds affects skiing mechanics and performance

2018

Arm swing has been shown to lead to greater maximal speed and movement economy in cross -country skiing. The current study aimed to investigate how arm swing alters skiing mechanics and contributes to performance and acceleration of the athlete’s centre of mass (COM). While skiing on snow seven highly skilled cross -country skiers simulated V2 -alternate skating without using ski poles and with double or single arm swing and without arm swing . During leg push -off the linear momentum of the body increased due to arm swing. Simultaneously, linear momentum of the arm(s) decreased in arm swing trials, indicating a transfer of momentum from arms to the rest of the body and being more prevalent…

Self-selected running gait modifications reduce acute impact loading, awkwardness, and effort

2021

Impact loading has been associated with running-related injuries, and gait retraining has been suggested as a means of reducing impact loading and lowering the risk of injury. However, gait retraining can lead to increased perceived awkwardness and effort. The influence of specifically trained and self-selected running gait modifications on acute impact loading, perceived awkwardness and effort is currently unclear. Sixteen habitual rearfoot/midfoot runners performed forefoot strike pattern, increased step rate, anterior trunk lean and self-selected running gait modifications on an instrumented treadmill based on real-time biofeedback. Impact loading, perceived awkwardness and effort scores…

Embedding energy consumption for lighting in the evaluation methods of the energy performance of buildings

2009

Modeling user preferences in content-based image retrieval: A novel attempt to bridge the semantic gap

2015

This paper is concerned with content-based image retrieval from a stochastic point of view. The semantic gap problem is addressed in two ways. First, a dimensional reduction is applied using the (pre-calculated) distances among images. The dimension of the reduced vector is the number of preferences that we allow the user to choose from, in this case, three levels. Second, the conditional probability distribution of the random user preference, given this reduced feature vector, is modeled using a proportional odds model. A new model is fitted at each iteration. The score used to rank the image database is based on the estimated probability function of the random preference. Additionally, so…

A principled approach to network-based classification and data representation

2013

Measures of similarity are fundamental in pattern recognition and data mining. Typically the Euclidean metric is used in this context, weighting all variables equally and therefore assuming equal relevance, which is very rare in real applications. In contrast, given an estimate of a conditional density function, the Fisher information calculated in primary data space implicitly measures the relevance of variables in a principled way by reference to auxiliary data such as class labels. This paper proposes a framework that uses a distance metric based on Fisher information to construct similarity networks that achieve a more informative and principled representation of data. The framework ena…

Three-dimensional object detection under arbitrary lighting conditions

2006

A novel method of 3D object recognition independent of lighting conditions is presented. The recognition model is based on a vector space representation using an orthonormal basis generated by the Lambertian reflectance functions obtained with distant light sources. Changing the lighting conditions corresponds to multiplying the elementary images by a constant factor and because of that, all possible lighting views will be elements that belong to that vector space. The recognition method proposed is based on the calculation of the angle between the vector associated with a certain illuminated 3D object and that subspace. We define the angle in terms of linear correlations to get shift and i…

Perceptually weighted optical flow for motion-based segmentation in MPEG-4 paradigm

2000

In the MPEG-4 paradigm, the sequence must be described in terms of meaningful objects. This meaningful, high-level representation should emerge from low-level primitives such as optical flow and prediction error which are the basic elements of previous-generation video coders. The accuracy of the high-level models strongly depends on the robustness of the primitives used. It is shown how perceptual weighting in optical flow computation gives rise to better motion estimates which consistently improve motion-based segmentation compared to equivalent unweighted motion estimates.

Stable Light-Emitting Electrochemical Cells Using Hyperbranched Polymer Electrolyte

2021

The choice of an adequate electrolyte is a fundamental aspect in polymer light-emitting electrochemical cells (PLECs) as it provides the in situ electrochemical doping and influences the performance of these devices. In this study, a hyperbranched polymer (Hybrane DEO750 8500) blended with a Li salt is used as a novel electrolyte in state-of-the-art Super Yellow (a polyphenylenevinylene) based LECs. Due to the desirable properties of the hyperbranched polymer and the homogeneous and smooth films that it forms with the emitting polymer, PLEC with excellent electroluminescent properties are obtained using a pulsed current bias scheme. The devices are very stable, with lifetimes in excess of 2…

(Ré)concilier éclairage urbain et environnement nocturne : les enjeux d’une controverse sociotechnique

2014

International audience; Our paper explains the birth of an environmental problem, i.e. light pollution, viewed as a socio-technical controversy. Supported by the actor-network approach, it traces over forty years the conditions of its emergence, transformation and dissemination to local, national and transnational levels and through various professional disciplines. Schematically, “environmentalists” uphold a holistic approach of “nocturnality” and define artificial light as a pollutant. Facing them, the “technicist” defends a segmented approach and defines artificial light as a nuisance. The introduction of this controversy into the political agenda leads to institutional decisions that gr…