3,391 research outputs found
Real-Time Distributed Aircraft Simulation through HLA
This paper presents some ongoing researches carried out in the context of the PRISE (Research Platform for Embedded Systems Engineering) Project. This platform has been designed to evaluate and validate new embedded system concepts and techniques through a special hardware and software environment. Since many actual embedded equipments are not available, their corresponding behavior is simulated using the HLA architecture, an IEEE standard for distributed simulation, and a Run-time infrastructure called CERTI and developed at ONERA. HLA is currently largely used in many simulation applications, but the limited performances of the RTIs raises doubts over the feasibility of HLA federations with real-time requirements. This paper addresses the problem of achieving real-time performances with HLA. Several experiments are discussed using well-known aircraft simulators such as the Microsoft Flight Simulator, FlightGear, and X-plane connected with the CERTI Run-time Infrastructure. The added value of these activities is to demonstrate that according to a set of innovative solutions, HLA is well suited to achieve hard real time constraints
Cross-task weakly supervised learning from instructional videos
In this paper we investigate learning visual models for the steps of ordinary
tasks using weak supervision via instructional narrations and an ordered list
of steps instead of strong supervision via temporal annotations. At the heart
of our approach is the observation that weakly supervised learning may be
easier if a model shares components while learning different steps: `pour egg'
should be trained jointly with other tasks involving `pour' and `egg'. We
formalize this in a component model for recognizing steps and a weakly
supervised learning framework that can learn this model under temporal
constraints from narration and the list of steps. Past data does not permit
systematic studying of sharing and so we also gather a new dataset, CrossTask,
aimed at assessing cross-task sharing. Our experiments demonstrate that sharing
across tasks improves performance, especially when done at the component level
and that our component model can parse previously unseen tasks by virtue of its
compositionality.Comment: 18 pages, 17 figures, to be published in proceedings of the CVPR,
201
Finding and proving the optimum : cooperative stochastic and deterministic search
In this article, we introduce a global cooperative approach between an Interval Branch and Bound Algorithm and an Evolutionary Algorithm, that takes advantage of both methods to optimize a function for which an inclusion function can be expressed. The Branch and Bound algorithm deletes whole blocks of the search space whereas the Evolutionary Algorithm looks for the optimum in the remaining space and sends to the IBBA the best evaluation found in order to improve its Bound. The two algorithms run independently and update common information through shared memory. The cooperative algorithm prevents premature and local convergence of the evolutionary algorithm, while speeding up the convergence of the branch and bound algorithm. Moreover, the result found is the proved global optimum. In part 1, a short background is introduced. Part 2.1 describes the basic Interval Branch and Bound Algorithm and part 2.2 the Evolutionary Algorithm. Part 3 introduces the cooperative algorithm and part 4 gives the results of the algorithms on benchmark functions. The last part concludes and gives suggestions of avenues of further research
DFT-s-OFDM for sub-THz Transmission -- Tracking and Compensation of Phase Noise
For future wireless communication technologies, an increase in capabilities
such as throughput is strongly expected. Transmission in the sub-THz bands (>90
GHz) seems to be the potential solution to meet the ever-increasing capacity
demands due to the large unexploited bandwidth. Oscillators used at these
frequencies generate phase noise that induces critical distortions in the
signal that must be addressed. The correlated nature of PN makes it difficult
to overcome. Nowadays, there is a growing interest in considering the extension
of multicarrier based waveforms of the 5G new radio for transmissions in the
sub-THz bands. In this paper, we introduce a new algorithm called the
interpolation filter (IF), which efficiently estimates and compensates PN
effects on DFT-s-OFDM systems. Specifically, it is based on the use of
stochastic properties of the PN and is compatible with the 3GPP phase tracking
reference signal scheme. We highlight a performance improvement over known
techniques when using high-order modulation.Comment: Paper accepted and will be presented at the IEEE CCNC 2023 Conference
that will be held in Las Vegas from January 8th to 11th, 202
Real-time distributed simulations in an HLA framework: Application to aircraft simulation
This paper presents some ongoing research carried out in the context of the PRISE Project (Research Platform for Embedded Systems Engineering). This platform has been designed to evaluate and validate new embedded system concepts and techniques through a special hardware and software environment. Since much actual embedded equipment is not available, corresponding behavior is simulated within a high-level architecture (HLA) federation implemented with a run-time infrastructure (RTI) called CERTI and developed at ONERA. HLA is currently largely used in many simulation applications, but the limited performances of the RTIs raise doubts over the feasibility of HLA federations with real-time requirements. This paper addresses the problem of achieving real-time performances with the HLA standard. Several experiments are discussed using well-known aircraft simulators such as Microsoft Flight Simulator, FlightGear, and X-plane connected with the CERTI RTI. The added value of these activities is to demonstrate that according to a set of innovative solutions, HLA architecture is well suited to achieve hard real-time constraints. Finally, a formal model guaranteeing the schedulability of concurrent processes is also proposed
Procédé et machine de fomation de capsules contenant un fluide
Selon un procĂ©dĂ© de fabrication de capsules (16) contenant un fluide, procĂšde par pas aux Ă©tapes suivantes; rĂ©ception de deux pans (11, 12) de film (1) thermoplastique, chaque pan (11, 12) comportant au moins une colonne (14a, 14b, 14c, 14d) de cavitĂ©s (10) formĂ©es; rapprochement des deux pans (11, 12) pour mettre en correspondance les cavitĂ©s (10) respectives de chaque pan et placage des pans (11, 12) par des paires de barres (301, 302, 303) qui pincent successivement les pans (11, 12) de part et d'autre des paires de colonnes de cavitĂ©s (10), remplissage de la poche dĂ©limitĂ©e entre deux paires de barres (301, 302, 303) par le fluide pour remplir les cavitĂ©s (10); soudure des pans (11, 12) autour des cavitĂ©s (10) pour former les capsules (16). Machine mettant en Ćuvre le procĂ©d
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