Well-designed arrangements of arrays of circular lossy dielectric rods with finite lengths have been exploited to obtain proper radiation patterns for microwave applications. Accelerated three-dimensional (3D) numeric...
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ISBN:
(纸本)9798350347401
Well-designed arrangements of arrays of circular lossy dielectric rods with finite lengths have been exploited to obtain proper radiation patterns for microwave applications. Accelerated three-dimensional (3D) numerical modeling of such radiation mechanisms via the multilevel fast multipole algorithm (MLFMA) is suitable for well-matched results with real-life experiments. Enabling rigorous and accurate analyses of the corresponding problems, MLFMA, has been observed to provide quasi-optimal designs within a reasonable period of time, when this algorithm is efficiently combined with genetic algorithms (GAs). However, as shown in this contribution, the corresponding two-dimensional (2D) multiple scattering modeling via a well-conditioned version of the T-matrix method provides a much faster tool for GAs to optimize radiation patterns for a goal set on the central cross section plane of the rod arrays. Optimized geometries obtained using a combination of the 2D solver and GAs have been validated by using a 3D solver based on MLFMA to demonstrate the feasibility of the approach.
Recently developed methods of monotonic optimization have been applied successfully for studying a wide class of nonconvex optimization problems, that includes, among others, generalized polynomial programming, genera...
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Recently developed methods of monotonic optimization have been applied successfully for studying a wide class of nonconvex optimization problems, that includes, among others, generalized polynomial programming, generalized multiplicative and fractional programming, discrete programming, optimization over the efficient set, complementarity problems. In the present paper the monotonic approach is extended to the General Bilevel Programming GBP Problem. It is shown that (GBP) can be transformed into a monotonic optimization problem which can then be solved by "polyblock" approximation or, more efficiently, by a branch-reduce-and-bound method using monotonicity cuts. The method is particularly suitable for Bilevel Convex Programming and Bilevel Linear Programming.
multilevel inverters are one of the most brilliant technology evolution in power conversion. It provides a stair wave output signal out of multi DC sources used as input. This paper presents a new multilevel inverter ...
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In this paper, the calculation of aircraft trimming process is presented in a sufficiently understandable way using a unique combination of global optimization theory and the direct hand-on computer simulation. The me...
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ISBN:
(纸本)9780769532998
In this paper, the calculation of aircraft trimming process is presented in a sufficiently understandable way using a unique combination of global optimization theory and the direct hand-on computer simulation. The methods of artificial intelligence and heuristic algorithms handling with the equations of airplane motion are presented in this paper. The main aim was to use them for trimming the flying aircraft to the steady state flight upon setting the flight conditions of various kinds. New approach of SOMA (Self Organizing Migrating Algorithm) has been used here to find the vehicle equilibrium state. The method can be practically utilized in construction of airplanes as well as the flight simulators design.
Adapting applications to optimally utilize available hardware is no mean feat: the plethora of choices for optimization techniques are infeasible to maximize manually. To this end, auto -tuning frameworks are used to ...
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Adapting applications to optimally utilize available hardware is no mean feat: the plethora of choices for optimization techniques are infeasible to maximize manually. To this end, auto -tuning frameworks are used to automate this task, which in turn use optimizationalgorithms to efficiently search the vast searchspaces. However, there is a lack of comparability in studies presenting advances in auto -tuning frameworks and the optimizationalgorithms incorporated. As each publication varies in the way experiments are conducted, metrics used, and results reported, comparing the performance of optimizationalgorithms among publications is infeasible. The auto -tuning community identified this as a key challenge at the 2022 Lorentz Center workshop on auto -tuning. The examination of the current state of the practice in this paper further underlines this. We propose a community -driven methodology composed of four steps regarding experimental setup, tuning budget, dealing with stochasticity, and quantifying performance. This methodology builds upon similar methodologies in other fields while taking into account the constraints and specific characteristics of the auto -tuning field, resulting in novel techniques. The methodology is demonstrated in a simple case study that compares the performance of several optimizationalgorithms used to auto -tune CUDA kernels on a set of modern GPUs. We provide a software tool to make the application of the methodology easy for authors, and simplifies reproducibility of results.
multilevel lot siZing (MLLS) problem is a combinational optimization problem which has been proved NP-hard without restrictive assumption on the product structure. Several evolutionary algorithms were developed to sol...
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Computational grids process large, computationally intensive problems on small data sets. In contrast, data grids process large computational problems that in turn require evaluating, mining and producing large amount...
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Computational grids process large, computationally intensive problems on small data sets. In contrast, data grids process large computational problems that in turn require evaluating, mining and producing large amounts of data. Replication, creating geographically disparate identical copies of data, is regarded as one of the major optimization techniques for reducing data access costs. In this paper, several replication algorithms are discussed. These algorithms were studied using the Grid simulator: OptorSim. OptorSim provides a modular framework within which optimization strategies can be studied under different Grid configurations. The goal is to explore the stability and transient behaviour of selected optimization techniques. We detail the design and implementation of OptorSim and analyze various replication algorithms based on different Grid workloads.
This paper analyses an optimum Total Harmonic Distortion (THD) value for multilevel inverters using Hybrid Particle Swarm optimization Algorithm (HPSO). The proposed paper instigates an algorithm which supersedes the ...
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ISBN:
(纸本)9789811016455;9789811016448
This paper analyses an optimum Total Harmonic Distortion (THD) value for multilevel inverters using Hybrid Particle Swarm optimization Algorithm (HPSO). The proposed paper instigates an algorithm which supersedes the conventional algorithms in finding out an optimum global value. The prime objective of this paper is to reduce the THD value of the Asymmetric H-bridge multilevel inverters by choosing appropriate values from the inequality constraints. The proposed algorithm is simulated for an 11-level H bridge inverter using matlab 2014 version software. The results interpreted seemed to have a satisfactory higher order harmonic elimination compared to the conventional methods.
In this work, we solve a problem of antenna selection (AS) for a multiple-input multiple-output (MIMO) system under the constraint of the channel capacity maximization. The biogeography-based optimization (BBO) algori...
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ISBN:
(纸本)9781509051779
In this work, we solve a problem of antenna selection (AS) for a multiple-input multiple-output (MIMO) system under the constraint of the channel capacity maximization. The biogeography-based optimization (BBO) algorithm is applied on the joint transmitter and receiver AS for the channel capacity function. We apply different BBO migration models for simulated channels. The comparisons with other popular evolutionary algorithms such as the genetic algorithm (GA) and the ant colony optimization (ACO) show the efficiency and the applicability of the BBO algorithm. Results are given for three representative scenarios involving selection of 2x4, 3x5, 4x6 antennas in a 16x16 MIMO system.
Mesh partitioning is an important problem that has extensive applications in many areas. multilevelalgorithms are a successful class of optimization techniques which address the mesh partitioning problem. In this pap...
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