In this letter, the spectrum allocation problem in cognitive radio was studied to improve the utilization of spectrum by optimizing the spectrum allocation factor. On the basis of investigating some evolutionary spect...
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ISBN:
(纸本)9781479962396
In this letter, the spectrum allocation problem in cognitive radio was studied to improve the utilization of spectrum by optimizing the spectrum allocation factor. On the basis of investigating some evolutionary spectrum allocation algorithms applied in the spectrum allocation problem, a new efficient taguchi algorithm based on orthogonal arrays (OA) was proposed to deal with the 0-1 discrete spectrum allocation optimization problem. The simulation results show that taguchi algorithm has a more promising ability in improving the utilization of spectrum resources when compared with traditional evolutionary algorithms. Besides, taguchi algorithm has the advantages of easy implementation and efficiency in reaching optimum solutions.
Underfloor air distribution (UFAD) systems are on the way of development owing to their substantial energy saving potential as well as their capability for establishing thermally comfortable environments. Comprehensiv...
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Underfloor air distribution (UFAD) systems are on the way of development owing to their substantial energy saving potential as well as their capability for establishing thermally comfortable environments. Comprehensive evaluating these systems necessitates considering multiple effective factors ranging in several levels, which significantly augments the number of test cases and can even make the conducting of research impossible. Proposing a methodology for combining CFD results and the taguchi optimization algorithm using the multi-response signal to noise (MRSN) analysis, the present study addresses this issue. In order to investigate the performance of UFAD systems applied in a densely occupied classroom from three fundamental viewpoints of thermal comfort, indoor air quality (IAQ), and energy saving, this research employs a multi-objective optimization approach. The utilized algorithm concludes that setting the following conditions provides the optimal state: (i) The underfloor diffusers beside the seats of occupants, (ii) The return vent at the height of 1.5 m from the floor, (iii) ACH equal to 14, (iv) Supply air temperature equal to 18 degrees C, and (v) Vertical air distribution from the underfloor diffusers. The ultimate simulation outcomes demonstrate that, according to the PMV and mean age of air values equal to 0.24 and 147 s in occupied and breathing zones, respectively, the thermal comfort conditions and desirable IAQ are established. Furthermore, energy saving compared to conventional mixing ventilation systems is a significant amount of 13.2%. In addition, local thermal comfort in terms of the vertical temperature difference and local convective cooling (draft) is achieved.
A novel approach is introduced for designing a miniaturized wearable antenna. Utilizing taguchi's philosophy typically entails numerous experimentations runs, but our method significantly reduces these by employin...
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A novel approach is introduced for designing a miniaturized wearable antenna. Utilizing taguchi's philosophy typically entails numerous experimentations runs, but our method significantly reduces these by employing a quasi-Newton approach with gradient descent to estimate process parameter ranges. This hybrid technique expedites convergence by streamlining experiments. Additionally, the taguchi array ensures a balanced design, equalizing factor weights. Unlike conventional taguchi methods, which risk trapping optimized results at local minima with increased repetitions, our modified technique mitigates this issue by adjusting level differences, aiming for global minima. Antenna design often involves competing objectives, such as size, impedance matching, cross-polarization, directivity, and frequency range. This study addresses these multiobjective challenges using a hybrid approach. The proposed method is applied to design and fabricate a biosafe miniaturized antenna for integration into clothing. The comparison of computed and measured antenna parameters confirms the accuracy of our solution while demonstrating a reduction in the required number of experiments. This innovative approach significantly advances the efficient design of wearable antennas. The biosafe wearable antenna demonstrated compliant specific absorption rate (SAR) (1.2 W/kg), robust mechanical performance (up to 40 degrees bending), and underwent human body effect investigation. Comparison of computed and measured antenna parameters confirms solution accuracy. By implementing the proposed hybrid approach, computational time is significantly reduced by 98%, outperforming electromagnetic (EM) solvers' built-in optimization.
In this paper, a new hybrid optimization approach for the pattern synthesis of linear antenna array is proposed. Hybrid approach (TAGAPSO) contains taguchi algorithm(TA), Genetic algorithm(GA) and Particle Swarm Optim...
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ISBN:
(纸本)9781538671320
In this paper, a new hybrid optimization approach for the pattern synthesis of linear antenna array is proposed. Hybrid approach (TAGAPSO) contains taguchi algorithm(TA), Genetic algorithm(GA) and Particle Swarm Optimization (PSO). The aim of the optimization is to obtain desired side lobe level and half power beam width of the linear antenna array. Optimization results obtained by TA, GA, PSO and TAGAPSO are compared. The results show that TAGAPSO is much better than TA, GA and PSO. Optimization goals satisfied via TAGAPSO are much better than the other methods. Results of TAGAPSO are also compared with the results obtained by High Frequency Structural Simulator (HFSS) in order to verify the results.
Multi-objective design optimization environments are used for electric vehicles and other traction applications to arrive at efficient motor drives. Typically, the environment includes characterization modules that in...
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ISBN:
(纸本)9781733509602
Multi-objective design optimization environments are used for electric vehicles and other traction applications to arrive at efficient motor drives. Typically, the environment includes characterization modules that involve the use of Electromagnetic Finite Element and State-Space models that require large number of iterations and computational time. This work proposes the utilization of a taguchi orthogonal arrays method in conjunction with a Particle Swarm Optimization search algorithm to reduce computational time needed in the design optimization of electric motors for traction applications. The effectiveness of the taguchi method in conjunction with the optimization environment is demonstrated in a case study involving a prototype of a Synchronous Reluctance Motor drive system.
This article addresses the problem of radar waveform design for imaging targets in a cluttered environment. A multistatic radar scenario is considered for sparse and random sensor positions. The target impulse respons...
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This article addresses the problem of radar waveform design for imaging targets in a cluttered environment. A multistatic radar scenario is considered for sparse and random sensor positions. The target impulse response is modeled using the simulated frequency response of a buried metallic mine, and the clutter is modeled using the compound Gaussian (CG) distribution. We explore novel waveform design techniques with respect to the mutual information (MI) criterion based on the CG clutter. The first method presents a waveform that exploits the CG distribution of the scene reflectivity function when projected onto a sparse basis. This is compared to the second method, called the target-specific approach that uses knowledge of the target and clutter frequency responses to optimize a matched illumination waveform. In both cases, the taguchi and particle swarm optimization solvers are employed for MI-based waveform design optimization. To validate and compare the effectiveness of the optimized waveforms, the resulting scene reflectivity function is estimated using the sparsity-driven regularization radar imaging method. Our experimental results demonstrate that both waveform optimization techniques result in significantly better image reconstruction performance than the traditional linear-frequency-modulated waveform, and that the target-specific approach additionally suppresses clutter information in the scene.
This paper investigates the optimization problem in wideband cognitive radio networks. It focuses on jointly optimizing the decision threshold, sensing time and transmission power to maximize the aggregate throughput ...
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This paper investigates the optimization problem in wideband cognitive radio networks. It focuses on jointly optimizing the decision threshold, sensing time and transmission power to maximize the aggregate throughput under the constraints of local interference, false-alarm probability, missed detection probability and maximal total power of each secondary user. Sequential parameter optimization strategy is introduced to deal with different optimization parameters in the optimization problem. It starts with power allocation first, with the optimal power allocation vector obtained by adaptive power allocation strategy, the gold section search method combined with taguchi algorithm is proposed to find the optimal sensing time with the optimal power allocation vector, and the optimal decision threshold with the optimal power allocation vector and sensing time is optimized through iterative process. Simulation results show that the proposed algorithm can achieve a better performance and is effective in solving such optimization problems.
In this research, the operating parameters of proton exchange membrane (PEM) electrolyzer are optimized in order to decrease the required input voltage using taguchi method. The considered parameters include the opera...
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In this research, the operating parameters of proton exchange membrane (PEM) electrolyzer are optimized in order to decrease the required input voltage using taguchi method. The considered parameters include the operating temperature, the pressure of cathode and anode, membrane water content, membrane thickness, and cathode and anode exchange current density. First, a thermodynamic model is developed for the PEM electrolyzer, and then the taguchi method is applied for optimization of the electrolyzer performance. The signal to noise ratio (SNR) and the analysis of variance (ANOVA) method are also performed to determine the contribution ratio of effective parameters. The results reveal that the optimal condition is achieved at maximum working temperature, membrane water content, and cathode and anode exchange current density and at minimum membrane thickness, cathode pressure, and anode pressure. The anode exchange current density has considerable effect on the electrolyzer voltage with contribution of 67.15% while the membrane water content and the anode pressure have a minor influence with contribution of 1.1% and 0.42%, respectively. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Technology advancement and the global tendency to use renewable energy in distributed generation units in the distribution network have been proposed as sources of energy *** the complexity of their protection,as well...
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Technology advancement and the global tendency to use renewable energy in distributed generation units in the distribution network have been proposed as sources of energy *** the complexity of their protection,as well as the operation of distributed generation resources in the distribution network,factors such as improving reliability,increasing production capacity of the distribution network,stabilizing the voltage of the distribution network,reducing peak clipping losses,as well as economic and environmental considerations,have expanded the influence of distributed generation(DG)resources in the distribution *** location of DG sources and their capacity are the key factors in the effectiveness of distributed generation in the voltage stability of distribution ***,along with the scattered production sources of electric vehicles with the ability to connect to the network,due to having an energy storage system,they are known as valuable resources that can provide various services to the power *** vehicles can empower the grid or be used as a storage supply source when parked and connected to the *** paper introduces and studies a two-stage planning framework for the concurrent management of many electric vehicles and distributed generation resources with private *** the first stage,the aim is to increase the profit of electric vehicles and distributed generation sources;finally,the purpose is to reduce operating *** proposed scheduling framework is tested on a distribution network connected to bus 5 of the RBTS sample *** distributed generation sources and electric vehicles,we integrate time-consistent load management into the *** to distributed generation sources such as photovoltaic systems and wind turbines and the studied design in the modeling,we use the taguchi TOAT algorithm to generate and reduce the scenario to ensure the uncertainty in renewable *** software is used t
The structural design parameters of a plastic centrifugal pump were calculated and modeled,and flow field simulation analysis of the model was performed using CFD,in the framework of an orthogonal design method(or exp...
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The structural design parameters of a plastic centrifugal pump were calculated and modeled,and flow field simulation analysis of the model was performed using CFD,in the framework of an orthogonal design method(or experiment).The inlet mounting angleβ1,outlet mounting angleβ2,wrap angleϕ,and impeller inlet diameter D1 of the pump impeller were the four factors assumed for the application of the orthogonal experiment,using the efficiency and Net Positive Suction Head(NPSH)as evaluation ***,taking the maximum efficiency and minimum NPSH of the plastic centrifugal pump as the evaluation factors,the parameters of the pump impeller were re-optimized through the taguchi algorithm(leading to the following optimal combination:inlet diameter 35 mm,inlet angle 26°,outlet angle 27°,and wrap angle 110°).The minimum NPSH and the maximum efficiency have been found to be 0.957%and 61.5%,respectively.
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