Search results for "object"
showing 10 items of 1888 documents
Considering safety issues in minimum losses reconfiguration for MV distribution networks
2009
This paper offers a new perspective over the traditional problem of the multiobjective optimal reconfiguration of electrical distribution systems in regular working state. The issue is indeed here formulated including also safety issues. Indeed, dimensioning the earth electrodes of their own secondary substations, distribution companies take into account the probable future configurations of the network due to transformations of overhead lines into cable lines or realization of new lines. On the contrary, they do not consider that, during normal working conditions. the structure of the network can be modified for long periods as a consequence of reconfiguration manoeuvres, with differences …
El tratamiento del ODS 13 en la enseñanza de Física y Química en Educación Secundaria
2020
En l’actualitat, l’educació té un paper fonamental en la lluita contra la situació d’emergència planetària en què ens trobem. Per aquest motiu és necessària la incorporació a les aules de l’Educació per a un Desenvolupament Sostenible (EDS). Aquesta té el ferm propòsit de formar ciutadans capaços de participar en l’adopció de decisions i de dur a terme mesures fonamentades per a avançar cap a la construcció d’un present i futur satisfactoris. El present treball analitza el tractament que es fa a l’Educació Secundària d’un dels Objectius de Desenvolupament Sostenible (ODS) de l’Agenda 2030, referent a una de les problemàtiques actuals més urgents i que requereix una major atenció i implicaci…
A Mission Impossible? Learning the Logic of Space with Impossible Figures in Experience-Based Mathematics Education
2016
Most visual effects based on mathematically and physically describable phenomena and formalizable processes. Creating visual illusions, paradox structures and ‘impossible’ figures through playful and artistic procedures, holds an exciting pedagogical opportunity for raising students’ interest towards mathematics and natural sciences and technical aspects of visual arts. The Experience Workshop Math-Art Movement has a number of pedagogical methods, which are connected to visual paradoxes and perspective illusions. In the first part of our article, we introduce classroom exercises connected to the Hungarian artist Tamás F. Farkas’s paradox structures and impossible figures. There are certain …
Protocol: A literature review about the use of crowdsourcing in educational environments
2016
<p>The objective with the protocol described in this paper is to review the existing literature in relation to the implementation of crowdsourcing in educational environments. It seeks to give answer to 4 questions. First, it seeks to answer the question of which kind of crowdsourcing initiatives are more appropriate to be used for educational activities. In second place it’s important to find out whether there is any particular discipline in which crowdsourcing, by its nature, can be applied more naturally. Third, it seeks to identify which factors influence both positively and negatively in the teaching/learning experience using crowdsourcing. Finally, the last question to answer, t…
Development of accelerometer-based light to vigorous physical activity in fitness profiles of school-aged children.
2021
This study examined the developmental trajectories of light (LPA) and moderate-to-vigorous physical activity (MVPA) in fitness profiles derived from motor competence, perceived motor competence, health-related fitness, and MVPA behaviour. Locomotor, stability, and object-control skills, muscular and cardiovascular fitness, and physical activity were assessed in 510 (girls 285, boys 225) Finnish school-aged children (Mage = 11.26 ± .33 years) over three years. Physical activity was measured using hip-mounted accelerometers. Fitness profiles were identified using latent profile analysis and the development of physical activity levels across four assessments was analysed with latent growth cur…
The unusual hydrodynamical behaviour of freshwater oncolites
1997
Algal concretions are frequent in calcareous environments, occuring as individual particles (oncolites) that are easily transported during floods. Several parameters have been measured and calculated for a population of 127 particles from French streams. These oncolites have a high porosity (mean 42.7%) and a low density (mean 1.65), in respect to quartz and calcite. Oncolites have a settling velocity 1.5 times lower than that of quartz grains with the same nominal diameter. The computation of multiple correlations results in a classification in terms of decreasing efficiency: shape coefficients (Corey, ψ, and SI of Sneed and Folk), nominal diameter, density, edge sharpness and roughness. A…
Multi-modal search for multiobjective optimization: an application to optimal smart grids management
2012
This paper studies the possibility to use efficient multimodal optimizers for multi-objective optimization. In this paper, the application area considered for such new approach is the optimal dispatch of energy sources in smart microgrids. The problem indeed shows a non uniform Pareto front and requires efficient optimal search methods. The idea is to exploit the potential of agents in population-based heuristics to improve diversity in the Pareto front, where solutions show the same rank and are thus equally weighted. Since Pareto dominance is at the basis of the theory of multi-objective optimization, most algorithms show the non dominance ranking as quality indicator, with some problem i…
Population and Query Interface for a Content-Based Video Database
2002
In this paper we describe the first full implementation of a content-based indexing and retrieval system for MPEG-2 and MPEG-4 videos. We consider a video as a collection of spatiotemporal segments called video objects; each video object is a sequence of video object planes. A set of representative video object planes is used to index each video object. During the database population, the operator, using a semi-automatic outlining tool we developed, manually selects video objects and insert some semantical information. Low-level visual features like color, texture, motion and geometry are automatically computed. The system has been implemented on a commercial relational DBMS and is based on…
Scratch detection and removal from static images using simple statistics and genetic algorithms
2002
This paper investigates the removal of line scratches from old movies and gives a twofold contribution. First, it presents simple technique for detecting the scratches, based on an analysis of the statistics of the grey levels. Second, the scratch removal is approached as an optimisation problem, and it is solved by using a genetic algorithm. The method can be classified as a static approach, as it works independently on each single frame of the sequence. It does not require any a-priori knowledge of the absolute position of the scratch, nor an external starting population of chromosomes for the genetic algorithm. The central column of the line scratch once detected is changed with a conven…
Future wood demands and ecosystem services trade-offs: A policy analysis in Norway
2023
To mitigate climate change, several European countries have launched policies to promote the development of a renewable resource-based bioeconomy. These bioeconomy strategies plan to use renewable biological resources, which will increase timber and biomass demands and will potentially conflict with multiple other ecosystem services provided by forests. In addition, these forest ecosystem services (FES) are also influenced by other, different, policy strategies, causing a potential mismatch in proposed management solutions for achieving the different policy goals. We evaluated how Norwegian forests can meet the projected wood and biomass demands from the international market for achieving m…