Search results for "Simulation"
showing 10 items of 5095 documents
Distributed optimal power flow for islanded microgrids: An application to the Smart Polygeneration Microgrid of the Genoa University
2016
In this work, the application of an original distributed optimal power flow method to test a microgrid in the Savona area, Italy is proposed. The microgrid shows different types of Distributed Energy Resources (DERs) and is connected to the main grid through a fixed power bus. Due to the high computational speed, the applied distributed Optimal Power Flow can be performed almost in real time, i.e. every 5 minutes or less. The operating solution found for generators, simply using local information, corresponds to a suboptimal condition with reduced losses, bus voltages and line currents within constrained intervals. The distributed optimization algorithm is iterative, but also fast. It is ba…
On the Visual Distraction Effects of Audio-Visual Route Guidance
2016
This is the first controlled quantitative analysis on the visual distraction effects of audio-visual route guidance in simulated, but ecologically realistic driving scenarios with dynamic maneuvers and self-controlled speed (N = 24). The audio-visual route guidance system under testing passed the set verification criteria, which was based on drivers’ preferred occlusion distances on the test routes. There were no significant effects of an upcoming maneuver instruction location (up, down) on the in-car display on any metric or on the experienced workload. The drivers’ median occlusion distances correlated significantly with median incar glance distances. There was no correlation between driv…
Pitch tilt rendering for an 8-DOF driving simulator
2015
International audience; Tilt coordination technique is used for reproducing a sustained linear acceleration in driving simulation by tilting the simulator cabin. Thus a part of gravity is interpreted as a horizontal acceleration. Between the slow rotational motion limited by the rotational perception threshold of semi-circular canals of vestibular system and the fast change of acceleration to render, the design of coupling motions of rotation and translation plays a critical role in the realism of driving simulator. We present here an experiment focusing on longitudinal accelerations rendering with pitch tilt coordination technique. Eight drivers experienced the same accelerations and decel…
Visual scale factor for speed perception rendering in car driving simulation
2010
Speed perception is an important task that the driver must perform continuously to control his/her vehicle. It appears that many factors influence this perception: height of the point of view, field of view, realism of the environment, but also realism of audio and proprioceptive rendering. If some high-performance car driving simulators are able to render motion satisfactorily according to all these criteria, it is not always the case. As a result, speed perception is thus often under estimated, leading into producing higher speeds than in real conditions. Perceptual validity is then not good enough to study driver's behavior. To solve this problem, a technique has recently seen the light,…
The role of expert evaluation for microsleep detection
2015
Abstract Recently, it has been shown by overnight driving simulation studies that microsleep density is the only known sleepiness indicator which rapidly increases within a few seconds immediately before sleepiness related crashes. This indicator is based solely on EEG and EOG and subsequent adaptive pattern recognition. Accurate microsleep recognition is very important for the performance of this sleepiness indicator. The question is whether expensive evaluations of microsleep events by a) experts are necessary or b) non-experts provide sufficient evaluations. Based on 11,114 microsleep events in case a) and 12,787 in case b) recognition accuracies were investigated utilizing (i) artificia…
Transient stability simulation of a fixed speed wind turbine by Matlab/Simulink
2007
This paper describes the dynamic behavior of a typical fixed speed wind turbine connected to the grid; the model is developed in the simulation tool Matlab/Simulink and created as a modular structure. The pitch control system is used for stabilization of the wind turbine at grid faults. In this way, voltage stability of the system with grid-connected wind turbines can be improved by using blade-angle control for a temporary reduction of the wind turbine power during a short-circuit fault in the grid. This paper shows a new variable control for maintaining of voltage stability, when a three-phase fault is applied close to the wind turbine and cleared by disconnecting the affected line. In th…
Simuler les changements de localisations résidentielles dans une agglomération. Les bases conceptuelles d'un modèle de choix
2010
International audience; L'idée explorée dans la thèse est que le choix d'une localisation résidentielle résulte de l'interaction entre facteurs de choix et de propension à l'action. Distinguer ces deux facteurs permet d'aborder le processus décisionnel dans son caractère dynamique. L'objectif principal est de concevoir un modèle de simulation des dynamiques de localisations résidentielles et, à partir de là, d'interroger l'influence de la diversité des comportements modélisés sur les configurations spatiales simulées. Nous projetons de calculer un très grand nombre de scénarios (500, 1000...), afin de déterminer les plages de variations des configurations spatiales résultantes (analyses de …
Simulation individu-centrée des mobilités résidentielles à l'aide d'un modèle dynamique prospectif (Mobisim)
2013
International audience; Dans un contexte de périurbanisation et de difficultés d'accès au logement pour certains types de ménages, la connaissance des choix résidentiels représente un enjeu majeur pour l'aménagement du territoire. La compréhension des dynamiques résidentielles et des phénomènes qui en résultent constitue un champ de recherche important, et a donné lieu au développement de nombreux outils de simulation (Raju et al. 1998; Benenson et al. 2002; Ettema et al.2011; Sener et al. 2011). Ces derniers permettent de reproduire les dynamiques ur- baines, en considérant différents scénarios de développement urbain.
Earth resistance measurements in urban contexts: Problems and possible solutions
2017
Both EN 50522 and IEEE Std. 81 propose the Fall of Potential Method (FPM) to carry out the measurement of the resistance to earth of an Earthing System (ES). However, in urban areas, the recommended distances between the ES and auxiliary electrodes are not easy to respect, due to the presence of buildings and tarmac. Moreover, unknown buried metallic parts, as well as the interconnection among the ESs made by the Distributor System Operator, could modify the earth potential profile of the area, affecting the measurement results. In this paper, the issues that could affect the measurement result if FPM is used in an urban context are presented. A parametric analysis, carried out with Comsol …
Analysing gene flow in heterogeneous landscapes: why and how to use genetic graphs?
2019
International audience; In heterogeneous landscapes, when species occupy discrete habitat patches, ecological connectivity is influenced by populations’ topology. Graph-theoretic methods constitute a relevant tool to reveal this topology and better analyse gene flow. Despite growing interest in genetic graphs, a better understanding of when and how to use them is lacking.To fill this gap, we simulated gene flow between 50 populations in different landscape configurations and constructed genetic graphs using various genetic distances and pruning (link selection) methods. We then compared metrics derived from these graphs to analogous metrics describing the topology and connectivity of the di…