作者:
Al-Homidan, SulimanKFUPM
Dept Math Dhahran 31261 Saudi Arabia KFUPM
Ctr Smart Mobil & Logist Dhahran 31261 Saudi Arabia
The task of deducing directed acyclic graphs from observational data has gained significant attention recently due to its broad applicability. Consequently, connecting the log-det characterization domain with the set ...
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The task of deducing directed acyclic graphs from observational data has gained significant attention recently due to its broad applicability. Consequently, connecting the log-det characterization domain with the set of M-matrices defined over the cone of positive definite matrices has emerged as a crucial approach in this field. However, experimentally collected data often deviates from the expected positive semidefinite structure due to introduced noise, posing a challenge in maintaining its physical structure. In this paper, we address this challenge by proposing four methods to reconstruct the initial matrix while maintaining its physical structure. Leveraging advanced techniques, including sequential quadratic programming (SQP), we minimize the impact of noise, ensuring the recovery of the reconstructed matrix. We provide a rigorous proof of convergence for the SQP method, highlighting its effectiveness in achieving reliable reconstructions. Through comparative numerical analyses, we demonstrate the effectiveness of our methods in preserving the original structure of the initial matrix, even in the presence of noise.
The current research is a revolution in the field of neural computation as a quite new stochastic technique based on Ricker wavelet neural networks (RWNNs) is developed to analyze the Maxwell fluid (Max-F) boundary la...
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The current research is a revolution in the field of neural computation as a quite new stochastic technique based on Ricker wavelet neural networks (RWNNs) is developed to analyze the Maxwell fluid (Max-F) boundary layer flow (BLF) with heat and mass transfer effects over an elongating surface. The global and local search solvers used with RWNNs are genetic algorithms (GAs) and sequential quadratic programming (SQP) respectively to design a new algorithm i.e. RWNNs-GASQP. The transformed nonlinear system of ODEs is acquired using the physical model represented by the flow and then solved using RWNNs-GASQP solver. The obtained numerical form results are successfully compared with reference results acquired through the Adams technique. The accuracy, convergence and effectiveness of the designed solver are identified using numerous statistical and performance analyses.
In this research-oriented study, dual diffusive Casson nanofluid stretching flow embedded in a Darcy-Forchheimer-type porous medium is scrutinized. A quite new computerized neuro-heuristic optimization technique based...
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In [4], Fletcher and Leyffer present a new method that solves nonlinear programming problems without a penalty function by SQP-Filter algorithm. It has attracted much attention due to its good numerical results. In th...
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In [4], Fletcher and Leyffer present a new method that solves nonlinear programming problems without a penalty function by SQP-Filter algorithm. It has attracted much attention due to its good numerical results. In this paper we propose a new SQP-Filter method which can overcome Maratos effect more effectively. We give stricter acceptant criteria when the iterative points are far from the optimal points and looser ones vice-versa. About this new method, the proof of global convergence is also presented under standard assumptions. Numerical results show that our method is efficient.
Model predictive control (MPC) of an unknown system that is modelled by Gaussian process (GP) techniques is studied. Using GP, the variances computed during the modelling and inference processes allow us to take model...
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Model predictive control (MPC) of an unknown system that is modelled by Gaussian process (GP) techniques is studied. Using GP, the variances computed during the modelling and inference processes allow us to take model uncertainty into account. The main issue in using MPC to control systems modelled by GP is the propagation of such uncertainties within the control horizon. In this study, two approaches to solve this problem, called GPMPC1 and GPMPC2, are proposed. With GPMPC1, the original stochastic model predictive control (SMPC) problem is relaxed to a deterministic non-linear MPC based on a basic linearised GP local model. The resulting optimisation problem, though non-convex, can be solved by the sequential quadratic programming. By incorporating the model variance into the state vector, an extended local model is derived. This model allows us to relax the non-convex MPC problem to a convex one which can be solved by an active-set method efficiently. The performance of both approaches is demonstrated by applying them to two trajectory tracking problems. Results show that both GPMPC1 and GPMPC2 produce effective controls but GPMPC2 is much more efficient computationally.
The optimal operating conditions for the primary end of an integrated steel plant, which essentially comprises of sintering plant, pelletizing plant, blast furnaces, oxygen steelmaking converters and electric are furn...
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The optimal operating conditions for the primary end of an integrated steel plant, which essentially comprises of sintering plant, pelletizing plant, blast furnaces, oxygen steelmaking converters and electric are furnace, are found through a modern technique of optimization, namely, genetic adaptive search (GAS), and also through classical techniques of simplex search with simulated annealing (ASM) and sequential quadratic programming (SOP). A comparison of these techniques shows that GAS outperforms both the classical methods and obtains the lowest cost solution. Based on this study, it is recommended that GAS be used, in preference to other methods, in complex steel plant optimization problems.
This article presents a solution model for the unit commitment problem (UCP) using fuzzy logic to address uncertainties in the problem. Hybrid tabu search (TS), particle swarm optimization (PSO) and sequential quadrat...
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This article presents a solution model for the unit commitment problem (UCP) using fuzzy logic to address uncertainties in the problem. Hybrid tabu search (TS), particle swarm optimization (PSO) and sequential quadratic programming (SQP) technique (hybrid TS-PSO-SQP) is used to schedule the generating units based on the fuzzy logic decisions. The fitness function for the hybrid TS-PSO-SQP is formulated by combining the objective function of UCP and a penalty calculated from the fuzzy logic decisions. Fuzzy decisions are made based on the statistics of the load demand error and spinning reserve maintained at each hour. TS are used to solve the combinatorial sub-problem of the UCP. An improved random perturbation scheme and a simple method for generating initial feasible commitment schedule are proposed for the TS method. The non-linear programming sub-problem of the UCP is solved using the hybrid PSO-SQP technique. Simulation results on a practical Neyveli Thermal Power Station system (NTPS) in India and several example systems validate, the presented UCP model is reasonable by ensuring quality solution with sufficient level of spinning reserve throughout the scheduling horizon for secure operation of the system. (c) 2005 Elsevier B.V All rights reserved.
This paper describes a new approach to solving the all-up (ground to mission) trajectory optimization problem. The problem considered in this paper is that of placing a maximum payload into a specified orbit, where a ...
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This paper describes a new approach to solving the all-up (ground to mission) trajectory optimization problem. The problem considered in this paper is that of placing a maximum payload into a specified orbit, where a booster is used to place the payload in a low Earth parking orbit from which an upper stage transfers the payload to its mission orbit. One approach to solving the all-up problem has been to combine the booster and upper stage into one large simulation/optimization problem;however, this results in a difficult problem that is computationally expensive to solve. The algorithm proposed in this paper does not require any all-up trajectories to be explicitly optimized, but simulates separately the booster and upper stage. The algorithm is based on solving the maximum throw weight to a park orbit (for the booster), maximum payload transfer from the park orbit to the mission orbit (for the upper stage), and a coordination problem that adjusts the park orbit parameters to find the all-up optimum (maximum) payload to the mission orbit.
This paper deals with the numerical approximation of the Levenberg-Marquardt SQP (LMSQP) method for parameter identification problems, which has been presented and analyzed in [M. Burger and W. Muhlhuber, Inverse Prob...
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This paper deals with the numerical approximation of the Levenberg-Marquardt SQP (LMSQP) method for parameter identification problems, which has been presented and analyzed in [M. Burger and W. Muhlhuber, Inverse Problems, 18 (2002), pp. 943-969]. It is shown that a Galerkin-type discretization leads to a convergent approximation and that the indefinite system arising from the Karush-Kuhn-Tucker (KKT) system is well-posed. In addition, we present a multilevel version of the Levenberg Marquardt method and discuss the simultaneous solution of the discretized KKT system by preconditioned iteration methods for indefinite problems. From a discussion of the numerical effort we conclude that these approaches may lead to a considerable speed-up with respect to standard iterative regularization methods that eliminate the underlying state equation. The numerical efficiency of the LMSQP method is confirmed by numerical examples.
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