Search results for "ORIENTATION"

2016

Processing natural scenes requires the visual system to integrate local features into global object descriptions. To achieve coherent representations, the human brain uses statistical dependencies to guide weighting of local feature conjunctions. Pairwise interactions among feature detectors in early visual areas may form the early substrate of these local feature bindings. To investigate local interaction structures in visual cortex, we combined psychophysical experiments with computational modeling and natural scene analysis. We first measured contrast thresholds for 2x2 grating patch arrangements (plaids), which differed in spatial frequency composition (low, high or mixed), number of gr…

2021

In the early 19th century, William H. Wollaston impressed the Royal Society of London with engravings of portraits. He manipulated facial features, such as the nose, and thereby dramatically changed the perceived gaze direction, although the eye region with iris and eye socket had remained unaltered. This Wollaston illusion can be thought of as head orientation attracting perceived gaze direction when the eye region is unchanged. In naturalistic viewing, the eye region changes with head orientation and typically produces a repulsion effect. Here we explore if there is a flip side to the illusion. Does the gaze direction also alter the perceived direction of the head? We used copies of the …

What are the relationships among Web 2.0, market orientation and innovativeness?

2013

PurposeFirms are adopting Web 2.0 technologies to improve collaboration, participation and communication; however there are few empirical studies testing the impact of this adoption. The purpose of this article is to analyze if there is a linkage amongst market orientation, Web 2.0 adoption and innovativeness.Design/methodology/approachStructural equation modeling was used to test the relationships amongst the variables. A sample of 244 firms of the hospitality industry was used. The theoretical approach is based on the market orientation and innovativeness, concepts, which have been studied by various authors in the literature.FindingsA positive relationship was found between market orient…

Effect of Hot Drawing on the Mechanical Properties of Biodegradable Fibers

2016

The use of biodegradable polymers is increasingly attracting interest over the last years, since they can reduce the environmental effects related to disposal of traditional plastics and, in general, the use of fossil, non-renewable resources. One of the most promising applications is represented by fibers production. However, the orientation and the crystallinity degrees can significantly affect the mechanical properties. Therefore, it is of interest to investigate on the optimum processing conditions, in order to improve the mechanical properties. In particular, while crystallinity can be slightly modified by the processing, orientation can be significantly improved. In this work, the eff…

Social comparisons at work as related to a cooperative social climate and to individual differences in social comparison orientation

2005

This study examined the frequency of social comparisons in a work setting, and the feelings that these comparisons evoked. These processes were related to individual differences in social comparison orientation, and to the perception of a cooperative social climate at work. The participants were 216 physicians from various health centers in the Community of Valencia in Spain. In general, upward comparisons occurred more often, and elicited more positive and less negative affect than downward comparisons. Those high in social comparison orientation reported relatively more upward as well as downward comparisons, more positive affect after downward comparisons, and more negative affect after …

Effects of school-based interventions on motivation towards physical activity in children and adolescents: A systematic review and meta-analysis

2020

Introduction Assuming that motivation is the key to initiate and sustain beneficial health behaviors, the aim of this systematic review was to analyze the effects of school-based physical activity interventions on a variety of motivational outcomes towards PA in school-aged children and adolescents. Methods A comprehensive literature search was carried out in six electronic databases to identify randomized controlled trials and quasi-experimental trials examining the effects of PA interventions implemented during the regular school day, e.g., during physical education lessons or lunch breaks. Primary outcomes of interest were students' motivation, basic psychological needs, goal orientation…

Finite index subgroups of mapping class groups

2011

Let g ≥ 3 and n ≥ 0, and let Mg,n be the mapping class group of a surface of genus g with n boundary components. We prove that Mg,n contains a unique subgroup of index 2g−1(2g − 1) up to conjugation, a unique subgroup of index 2g−1(2g + 1) up to conjugation, and the other proper subgroups ofMg,n are of index greater than 2g−1(2g+1). In particular, the minimum index for a proper subgroup of Mg,n is 2g−1(2g − 1). AMS Subject Classification. Primary: 57M99. Secondary: 20G40, 20E28. 0 Introduction and statement of results The interaction between mapping class groups and finite groups has long been a topic of interest. The famous Hurwitz bound of 1893 showed that the mapping class group of a clo…

Engager une réflexion sur les espaces et leur utilisation pour ne pas “perdre le nord” (ni le sud)

2011

International audience; Colloque AUF Rabat-Kénitra, Maroc (31-10 / 2-11 2011) Dans le cadre de la thématique de ce colloque, la question est : comment l’élaboration, l’interrogation et la diffusion des littératures et cultures « aux suds », et non « du sud » ou « des suds » peuvent-elles permettre une réorientation des travaux et des relations ? Aux suds : il est question d’une localisation, laquelle est plurielle, donc vécue, puisque tout dépend d’où on se place pour parler de sud. Tandis que « du » ou même « des suds » évoque l’orientation centre-périphérie, venue de Fernand Braudel et Samir Amin, entre autres, soit une vision à dominante géopolitique et économique. Pour répondre à la que…

Extraction de primitives à partir d'images de lumière structurée

2013

National audience; Les attributs géométriques tels que la courbure ou la normale constituent des informations complémentaires aux points 3D obtenus suite à la numérisation d'une surface ou d'un objet. Dans la chaine 3D classique, présentant une structure séquentielle, ces informations sont déterminées à partir du nuage de points dense (issus par exemple d'un scanner 3D). Par la suite, elles sont utilisées pour diminuer la quantité d'information et permettre ainsi d'aboutir à un modèle simplifié (compressé ou modélisé sous forme de primitives). Dans cet article, nous nous intéressons à la possibilité d'extraire certains des attributs mentionnés plus haut, directement à partir des images 2D o…

Orientation of Polar Molecules by Laser Induced Adiabatic Passage

2002

International audience; We show that two overlapping linearly polarized laser pulses of frequencies ω and its second harmonic 2ω can strongly orient linear polar molecules, by adiabatic passage along dressed states. The resulting robust orientation can be interpreted as a laser-induced localization in the effective double well potential created by the fields, which induces a preliminary molecular alignment. The direction of the orientation can be selected by the relative phase of the fields.