Search results for " Computer science"
showing 10 items of 3983 documents
An analysis of model predictive control with integral action applied to digital displacement cylinders
2020
This article aims to analyze Model Predictive Control (MPC) for the control of multi-chamber cylinders. MPC with and without integral action has been introduced. Three different algorithms have been used to solve the optimization problem in the MPC. The different algorithms have been compared with an industrial solver. The influence of changing mass, choosing a different middle line pressure, system delays, signal noise, velocity estimation, and changing pressure levels has been investigated. It is concluded that for the small prediction horizon used in the paper a simple algorithm such as A can produce results as good as the previously used Differential Evolution algorithm in less than hal…
A Dataset of Annotated Omnidirectional Videos for Distancing Applications
2021
Omnidirectional (or 360°) cameras are acquisition devices that, in the next few years, could have a big impact on video surveillance applications, research, and industry, as they can record a spherical view of a whole environment from every perspective. This paper presents two new contributions to the research community: the CVIP360 dataset, an annotated dataset of 360° videos for distancing applications, and a new method to estimate the distances of objects in a scene from a single 360° image. The CVIP360 dataset includes 16 videos acquired outdoors and indoors, annotated by adding information about the pedestrians in the scene (bounding boxes) and the distances to the camera of some point…
Service Differentiation for NoC-based Multimedia Applications
2015
International audience; As the communication on-chip evolves toward the global multi-service network, various applications with different service requirements have emerged. A key factor is the support services with a guaranteed quality. The differentiated service with double physical channels is seen as the key technology to achieve this goal. It is focused on the control of traffic and recognizing the need for aspects for the management plan achieved by the bandwidth broker. In this paper, a novel QoS architecture for multimedia application over NoC is proposed. The gains in latency and in resource are possible due to the simplicity of the NoC architecture.
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,…
Statistical properties of general Markov dynamical sources: applications to information theory
2004
In \textitDynamical sources in information theory: fundamental intervals and word prefixes, B. Vallée studies statistical properties of words generated by dynamical sources. This is done using generalized Ruelle operators. The aim of this article is to generalize sources for which the results hold. First, we avoid the use of Grotendieck theory and Fredholm determinants, this allows dynamical sources that cannot be extended to a complex disk or that are not analytic. Second, we consider Markov sources: the language generated by the source over an alphabet \textbfM is not necessarily \textbfM^*.
Regularization Preserving Localization of Close Edges
2007
International audience; In this letter, we address the problem of the influence of neighbor edges and their effect on the edge delocalization while extracting a neighbor contour by a derivative approach. The properties to be fulfilled by the regularization operators to minimize or suppress this side effect are deduced, and the best detectors are pointed out. The study is carried out in 1-D for discrete signal. We show that among the derivative filters, one of them can correctly detect our model edges without being influenced by a neighboring transition, whatever their separation distance is and their respective amplitude is. A model of contour and close transitions is presented and used through…
Scatter search for an uncapacitated p-hub median problem
2015
Scatter search is a population-based method that has been shown to yield high-quality outcomes for combinatorial optimization problems. It uses strategies for combining solution vectors that have proved effective in a variety of problem settings. In this paper, we present a scatter search implementation for an NP -hard variant of the classic p-hub median problem. Specifically, we tackle the uncapacitated r-allocation p-hub median problem, which consists of minimizing the cost of transporting the traffics between nodes of a network through special facilities that act as transshipment points. This problem has a significant number of applications in practice, such as the design of transportati…
A hybrid evolution strategy for the open vehicle routing problem
2010
This paper presents a hybrid evolution strategy (ES) for solving the open vehicle routing problem (OVRP), which is a well-known combinatorial optimization problem that addresses the service of a set of customers using a homogeneous fleet of non-depot returning capacitated vehicles. The objective is to minimize the fleet size and the distance traveled. The proposed solution method manipulates a population of @m individuals using a (@m+@l)-ES; at each generation, a new intermediate population of @l offspring is produced via mutation, using arcs extracted from parent individuals. The selection and combination of arcs is dictated by a vector of strategy parameters. A multi-parent recombination …
Memetic Compact Differential Evolution for Cartesian Robot Control
2010
This article deals with optimization problems to be solved in the absence of a full power computer device. The goal is to solve a complex optimization problem by using a control card related to portable devices, e.g. for the control of commercial robots. In order to handle this class of optimization problems, a novel Memetic Computing approach is presented. The proposed algorithm employs a Differential Evolution framework which instead of processing an actual population of candidate solutions, makes use of a statistical representation of the population which evolves over time. In addition, the framework uses a stochastic local search algorithm which attempts to enhance the performance of th…