Search results for " Distance"
showing 10 items of 696 documents
High Precision Astrometry Over Large Angular Scales with Closure Constraints: The Triplet 1803+784/1928+738/2007+777
1996
The technique of differential astrometry using the phase-delay VLBI observable promises fractional precisions of ~2 × 10−9 in the determination of the separation of sources 5° or 6° apart on the sky (Guirado et al. 1995a; Lara et al. 1996). In our present research we seek further improvement in this technique through using triplets of radio sources, which provide a closure constraint in the determination of relative angular positions. This constraint not only eases the resolution of the phase-cycle ambiguities (a major problem in the least-squares approach to astrometry with phase delays), but it also strongly constrains the space of allowable parameter values.
A new approximation procedure for fractals
2003
AbstractThis paper is based upon Hutchinson's theory of generating fractals as fixed points of a finite set of contractions, when considering this finite set of contractions as a contractive set-valued map.We approximate the fractal using some preselected parameters and we obtain formulae describing the “distance” between the “exact fractal” and the “approximate fractal” in terms of the preselected parameters. Some examples and also computation programs are given, showing how our procedure works.
On the Extension of the DIRECT Algorithm to Multiple Objectives
2020
AbstractDeterministic global optimization algorithms like Piyavskii–Shubert, direct, ego and many more, have a recognized standing, for problems with many local optima. Although many single objective optimization algorithms have been extended to multiple objectives, completely deterministic algorithms for nonlinear problems with guarantees of convergence to global Pareto optimality are still missing. For instance, deterministic algorithms usually make use of some form of scalarization, which may lead to incomplete representations of the Pareto optimal set. Thus, all global Pareto optima may not be obtained, especially in nonconvex cases. On the other hand, algorithms attempting to produce r…
A quantitative reverse Faber-Krahn inequality for the first Robin eigenvalue with negative boundary parameter
2021
The aim of this paper is to prove a quantitative form of a reverse Faber-Krahn type inequality for the first Robin Laplacian eigenvalueλβwith negative boundary parameter among convex sets of prescribed perimeter. In that framework, the ball is the only maximizer forλβand the distance from the optimal set is considered in terms of Hausdorff distance. The key point of our stategy is to prove a quantitative reverse Faber-Krahn inequality for the first eigenvalue of a Steklov-type problem related to the original Robin problem.
What makes learning and understanding in virtual teams so difficult?
2004
The ideas presented in this article are especially challenged by critical questions raised by the other authors in this special issue. One of the core questions throughout the different studies is whether participants in distributed learning groups are able to successfully work on a common task and achieve a type of interaction that leads them to educationally relevant higher-level discussion and learning. This article discusses the central findings of these studies in light of the recent research on computer-supported collaborative learning. At the beginning of the article, typical problems and challenges related to learning in virtual teams are described. In the end of the discussion, som…
E-learning: Web-based education
2006
Purpose of review This review introduces state-of-the-art Web-based education and shows how the e-learning model can be applied to an anaesthesia department using Open Source solutions, as well as lifelong learning programs, which is happening in several European research projects. Recent findings The definition of the term e-learning is still a work in progress due to the fact that technologies are evolving every day and it is difficult to improve teaching methodologies or to adapt traditional methods to a new or already existing educational model. The European Community is funding several research projects to define the new common market place for tomorrow's educational system; this is le…
Digital knowledge sharing and creative performance: Work from home during the COVID-19 pandemic
2021
Abstract The outbreak of the COVID-19 pandemic and the resulting social distancing requirements have led to major disruptions in the world of work. The outcomes of the enforced and large-scale work from home (WFH) practices are currently largely unexplored. This study aims to address this gap in the research by investigating the external and internal digital knowledge sharing (DKS) and creative performance (CP) of employees under these extraordinary circumstances. The social capital theory was utilized as the theoretical lens for examining the associations of DKS and CP with demographic, individual, and organizational factors. An online cross-sectional survey was carried out among knowledge…
Identifying predictive factors in compliance with the COVID-19 containment measures: A mediation analysis
2021
Giusy Danila Valenti, Palmira Faraci Faculty of Human and Social Sciences, University of Enna âKoreâ, Enna, ItalyCorrespondence: Giusy Danila ValentiCittadella Universitaria, 94100, ItalyEmail giusy.valenti@unikore.itIntroduction: The outbreak of the COVID-19 pandemic has led governments to implement some containment measures to flatten the curve of the diffusion of the virus. The current study aims to investigate individual differences in compliance with these restrictive behaviors. In a sample of Italian individuals (N = 300), we examined whether sociodemographic factors, personality traits, fatalism, and fear could be considered as possible predictors.Methods: We performed a series o…
Self-isolation for the self-centered: Negative framing increases narcissists' willingness to self-isolate during COVID-19 through higher response eff…
2021
Abstract The coronavirus (COVID-19) pandemic has come with various health recommendations restricting personal freedom, such as social distancing and self-isolation. Considering the personal sacrifices involved, not all individuals are equally willing to comply with such recommendations, which might pose a health hazard further down the line. In a high-powered study (N = 800), we show that individual differences in narcissism influence the willingness to self-isolate during pandemics, with individuals high (vs. low) in narcissism being less willing to self-isolate. However, this tendency can be offset by tailored message framing. Specifically, individuals high (vs. low) in narcissism are mo…
The impact of COVID-19 quarantine on youth: from physical inactivity to pediatric depreobesity
2020
Objective : To comment on how COVID-19 quarantine has affected physical activity in youth and induced a pediatric depreobesity status. Key Points Scarce literature has described the impact of COVID-19 on youth levels of moderate to vigorous physical activity. Physical inactivity and social distancing could lead to physical and psychosocial problems increasing the risk of obesity and depression. Regular moderate to vigorous physical activity plays an essential role to limit or prevent the negative consequences of prolonged quarantine periods on pediatric depreobesity.