Search results for "Multia"
showing 10 items of 159 documents
Optimal Trajectories for Spacecraft Rendezvous
2007
The efficient execution of a rendezvous maneuver is an essential component of various types of space missions. This work describes the formulation and numerical investigation of the thrust function required to minimize the time or fuel required for the terminal phase of the rendezvous of two spacecraft. The particular rendezvous studied concerns a target spacecraft in a circular orbit and a chaser spacecraft with an initial separation distance and separation velocity in all three dimensions. First, the time-optimal rendezvous is investigated followed by the fuel-optimal rendezvous for three values of the max-thrust acceleration via the sequential gradient-restoration algorithm. Then, the ti…
Towards an integrated approach to emergency management: interdisciplinary challenges for research and practice
2015
This article presents an interdisciplinary vision for large-scale integrated emergency management that has been inspired by the transition from platform centric to integrated operations in the oil and gas fields, which uses remote emergency control centres collaborating virtually with local responders. The article discusses some of the most salient research challenges for integrated emergency management, including the role of mobile technology, human-centred sensing, citizen participation and social media, and the socio-cultural determinants of disaster management. The purpose of this article is to frame an integrated emergency management approach that adopts a multi-disciplinary approach, …
Qualifying Building Information Models with Multi-Agent System
2011
6 pages; International audience; This paper presents a new approach combining the 3D elements composing the environment of mobile agents with semantic descriptors from building information models. Our proposal is based on the IFC standard which is used in the field of Civil Engineering to build digital models of buildings during the design phase. The semantic of IFC objects composing the 3D environment is used to select and set up 3D objects and elements of simulation scenarios. The result of this process dynamically generates the input files to the JaSIM environment that performs the simulation.
Toward fast and accurate emergency cases detection in BSNs
2020
International audience; In body sensor networks (BSNs), medical sensors capture physiological data from the human body and send them to the coordinator who act as a gateway to health care. The main aim of BSNs is to save peoples' lives. Therefore, fast and correct detection of emergencies while maintaining low-energy consumption of sensors is essential requirement of BSNs. In this study, the authors propose a new adaptive data sampling approach, where the sampling ratio is adapted based on the sensed data variation. The idea is to use the modified version of the cumulative sum (CUSUM) algorithm (modified CUSUM) that they previously proposed for wireless sensor networks to monitor the data v…
A Rule-Based Multi-agent System for Local Traffic Management
2009
Road Traffic presents a high dynamism which makes necessary the development of traffic management and control strategies to improve traffic flows and more important, road safety. So it is needed the use of intelligent systems to support traffic organizations and road operators to cope with incidents. In this paper we introduce a local autonomous system for traffic management. This way, though there could be a breakdown in the communications between the local system and the TCC, the local system will be able to warn the road users in case of incidents. The system uses multiagent technology to work with the specific characteristics of traffic domain. The expert MAS system is ruled-based that …
MCMI-III Profiles of Convicted Contact Sexual Offenders: A Cluster Analysis
2019
As suggested by previous research, the study of personality traits among sexual offenders could be an important consideration in the understanding of sexual offending. This study aims to explore the possibility of classifying sexual offenders according to their personality profiles. Based on the MCMI-III scores of 97 convicted contact sexual offenders, a cluster hierarchical analysis was performed. Next, the groups were characterized according to their sociodemographic and criminological variables and significant differences between them were sought. The two clusters found did not show different MCMI-III prototypical personality profiles, and both groups only varied in the degree of general…
Using Semantics in the Environment for Multiagent-Based Simulation
2014
In this chapter, we carry out an overview and analysis of the usage of semantics to enhance environments in the domain of multiagent-based simulations. Firstly, we take a look at what a multiagent system (MAS) is, and after that we look at the environment for these systems, and why semantics are required in it. Various propositions to put semantics in the environment for MAS are then reviewed, as well as the strengths and weaknesses for these approaches. These propositions are grouped together under two categories, regarding whether the proposed approach is based on only the environment or on both the agents and the environment. The paper is then concluded with findings that have emerged by…
Characterization of opal photonic hetero-crystals by light scattering
2006
Spectra of the light scattered in the heterogeneous photonic crystal based on the thin triple-film opal, which was prepared by successive, convective force-assisted crystallisation of colloidal suspensions containing spheres of 374, 474 and again 374 nm in diameter, have been studied in the wavelength range of low order photonic bandgaps. If the ballistic regime of light propagation is preserved, the forward scattered light becomes the subject of the diffraction attenuation, whereas the backscattered light experiences both the diffraction enhancement and attenuation. A variety of possible configurations of scattered light measurements have been examined and corresponding spectra of scattere…
Multialternating graded polynomials and growth of polynomial identities
2012
Let G be a finite group and A a finite dimensional G-graded algebra over a field of characteristic zero. When A is simple as a G-graded algebra, by mean of Regev central polynomials we construct multialternating graded polynomials of arbitrarily large degree non vanishing on A. As a consequence we compute the exponential rate of growth of the sequence of graded codimensions of an arbitrary G-graded algebra satisfying an ordinary polynomial identity. In particular we show it is an integer. The result was proviously known in case G is abelian.
Modèle dynamique multiniveau et holonique pour la simulation d'un système complexe à grande échelle avec environnement spatial : Application à la sim…
2020
Nowadays, with the emergence of connected objects and cars, road traffic systems become more and more complex and exhibit hierarchical behaviours at several levels of detail. The multilevel modeling approach is an appropriate approach to represent traffic from several perspectives. Multilevel models are also an appropriate approach to model large-scale complex systems such as road traffic. However, most of the multilevel models of traffic proposed in the literature are static because they use a set of predefined levels of detail and these representations cannot change during simulation. Moreover, these multilevel models generally consider only two levels of detail. Few works have been inter…