Search results for "Others"
showing 10 items of 524 documents
Robust control for autonomous spacecraft evacuation with model uncertainty and upper bound of performance with constraints
2014
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2014/589381 This paper studies the problem of guaranteed cost control for spacecraft evacuation. The relative dynamic model is established based on Clohessy-Wiltshire (C-W) equations. The paper has taken parameter uncertainty, output tracking, disturbance attenuation, and fuel cost into consideration. The paper introduces a new Lyapunov approach, so the controller design problem can be transferred into a convex optimization problem subject to linear matrix inequality (LMI) constraints. By using the controller, the spacecraft evacuation can be …
An ILS-Based Metaheuristic for the Stacker Crane Problem
2012
[EN] In this paper we propose a metaheuristic algorithm for the Stacker Crane Problem. This is an NP-hard arc routing problem whose name derives from the practical problem of operating a crane. Here we present a formulation and a lower bound for this problem and propose a metaheuristic algorithm based on the combination of a Multi-start and an Iterated Local Search procedures. Computational results on a large set of instances are presented.
Mathematical Programming Methods for the Evaluation of Dynamic Plastic Deformations
1990
Dynamic plastic deformation can be evaluated with two accuracy levels, nemely either by a full analysis making use of a step-by-step procedure, or by a simplified analysis making use of a bounding technique. Both procedures can be achieved by means a unified mathematical programming approach here presented. It is shown that for a full analysis both the direct and indirect methods of linear dynamics coupled with mathematical programming methods can be successfully applied, whereas for a simplified analysis a convergent bounding principle, holding both below and above the shakedown limit, can be utilized to produce an efficient linear programming-based algorithm.
Finding Satisfactory Near-Optimal Solutions in Location Problems
2003
We develope and analyze a heuristic procedure to solve a fuzzy version of the p-median problem in which we allow part of the demand not to be covered in order to reduce the transport cost. This can be used to improve a given solution of the crisp p-median problem as well as to give to the decision-maker a range of alternative locations that can be adequate according to his or her own criteria.
Hating among adolescents: Common contributions of cognitive distortions and maladaptive personality traits
2019
The phenomenon of hating is becoming common in adolescence, but it has been rarely investigated. The study aimed to examine the relationships between hating behaviors, maladaptive personality traits, and cognitive distortions, and to explore whether cognitive distortions might intervene in the relationship between personality traits and hating. Method: Participants (200 boys and 202 girls) completed the Hating Adolescents Test (HAT), the Personality Inventory for DSM-5-Brief Form-Children (PID-5), and the How I Think Questionnaire (HITQ). Results: Preliminary results showed significant gender differences in the study’s variables: boys reported higher scores than girls on hating and on cogni…
Efficient Port Pricing: A New Methodology Applied to Spanish Commercial Ports
2000
This paper presents a methodology for determining efficient tariffs for the services provided by commercial ports. With this method, efficient unit profits can be obtained for the services offered and their margins of sensitivity can be found. This allows port authorities to determine what actions should be taken with regard to tariffs and/or variable costs in order to optimise their economic results. At the same time, shadow prices of port resources and their limits of sensitivity can be obtained, thus providing port authorities with orientation regarding which resources should be augmented and by how much. In the early 90's, this methodology was applied to all Spanish commercial ports and…
Network Connectivity and Area Coverage for UAV Fleet Mobility Model with Energy Constraint
2016
International audience; Our main focus through the present paper is on developing an original distributed mobility model for autonomous fleet of interconnected UAVs (Unmanned Aerial Vehicles) performing an area exploration mission. The UAVs, equipped with wireless ad-hoc capabilities, are required to optimally explore an area while maintaining connectivity with their neighboring UAVs and the base station. Because energy is a scarce resource, especially for UAVs, its wise management is quite beneficial for the network lifetime and mission success. Hence, the proposed mobility model, compared to other models in the literature, is the first to ever include the remaining energy level as decisio…
Single-channel EEG-based subject identification using visual stimuli
2021
Electroencephalography (EEG) signals have been recently proposed as a biometrics modality due to some inherent advantages over traditional biometric approaches. In this work, we studied the performance of individual EEG channels for the task of subject identification in the context of EEG-based biometrics using a recently proposed benchmark dataset that contains EEG recordings acquired under various visual and non-visual stimuli using a low-cost consumer-grade EEG device. Results showed that specific EEG electrodes provide consistently higher identification accuracy regardless of the feature and stimuli types used, while features based on the Mel Frequency Cepstral Coefficients (MFCC) provi…
Research of Tool-Coupling Based Electro-hydraulic System Development Method
2015
This paper introduces a new kind of tool-coupling based electro-hydraulic system development method including designing character-oriented electro-hydraulic system development and design procedure, co-simulation based system coupling strategy, client-server model management method. An integrated development platform is designed for co-simulation among AMESim, Matlab\Simulink, Flowmaster, Saber and Simplorer. The platform can manage each simulator’s models and co-simulation procedure. The result illustrates tool coupling based electro-hydraulic system development method can improve the efficiency of multi-team collaborative design for electro-hydraulic system and also can analyze and evaluat…
Modeling and simulation of an offshore crane
2018
This paper presents a mathematical modeling of a crane system using robot modeling theory as well as the numerical simulation of the dynamics of a crane and a marine craft. The simulations are performed in SimulationX and Matlab Simulink. The simulation platform includes a SimulationX-model of the crane, a realistic model of a marine craft using the Marine Systems Simulator(MSS) and the hydrodynamic sea-keeping calculations (VERES program code). The simulation results show a very good picture of the dynamic behavior of the real crane in offshore environment and verify the validation and effectiveness of the presented modeling approach.