A Radial Basis Function Neural Network (RBFNN) based diagnosis system for automatic identification of Cerebral Vascular Accident (CVA) through analysis of Computer Tomographic images (CT) is presented. For the design ...
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ISBN:
(纸本)9781509024872
A Radial Basis Function Neural Network (RBFNN) based diagnosis system for automatic identification of Cerebral Vascular Accident (CVA) through analysis of Computer Tomographic images (CT) is presented. For the design of a neural network classifier, most published methods just focus on the feature selection aspect and do not consider any approach for determining a model structure that best fits the application at their hand. Moreover, considering the domain of lesion detection from brain tissues, their feature space rarely contains symmetry/asymmetry information with respect to ideal mid-sagittal line. Another issue is how to handle multiple conflicting objectives in the design process, such as the maximization of both specificity and sensitivity, enforcing as well generalization. To deal with these challenges, a multiobjectivegeneticalgorithm (MOGA) based approach is used to determine the architecture of the classifier, its corresponding parameters and input features subject to multiple objectives, as well as their corresponding restrictions and priorities.
A three dimensional numerical simulation was performed to study the effect of the shape and the angle of attack of the winglet vortex generator on the heat transfer and fluid flow characteristics in a rectangular heat...
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A three dimensional numerical simulation was performed to study the effect of the shape and the angle of attack of the winglet vortex generator on the heat transfer and fluid flow characteristics in a rectangular heat sink. The mass, momentum and energy equations were solved using finite volume method by considering the steady state, laminar and incompressible fluid flow. The average and local Nusselt number and pressure drop were investigated in the presence of the vortex generators at different shapes and angles of attack. To achieve a maximum heat transfer enhancement and a minimum pressure drop, the optimal values of these parameters were calculated using the Pareto optimal strategy. For this purpose, computational fluid dynamics analyses, multi-objective genetic algorithm and artificial neural networks were combined together and used in the optimization process. Finally, the optimal values of these parameters were presented. (C) 2015 Elsevier Ltd. All rights reserved.
The complexity of the Vehicle Routing Problems (VRPs) and their applications in our day to day life has garnered a lot of attentions in the area of optimization. Recently, attentions have turned to multi-objective VRP...
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ISBN:
(纸本)9781479944675
The complexity of the Vehicle Routing Problems (VRPs) and their applications in our day to day life has garnered a lot of attentions in the area of optimization. Recently, attentions have turned to multi-objective VRPs with multi-objective genetic algorithms (MOGAs). MOGAs, thanks to its genetic operators such as selection, crossover, and/or mutation, constantly modify a population of solutions in order to find optimal solutions. However, given the complexity of VRPs, conventional crossover operators have major drawbacks. The Best Cost Route Crossover is lately gaining popularity in solving multi-objective VRPs. It employs a brute force approach to generate new children. Such approach may be unacceptable when presented with a relatively large problem instance. In this paper, we introduce a new crossover operator, called Partially Optimized Cyclic Shift Crossover (POCSX). A comparative study, between a MOGA based on POCSX, and a MOGA which is based on the Best Cost Route Crossover affirms the level of competitiveness of the former.
Proportional integral (PI) controller is a widely used controller strategy. It has two gain constants: proportional(k(p)) and integral(k(i)) gain constant. The dynamics of the PI controller depends on the values of th...
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Proportional integral (PI) controller is a widely used controller strategy. It has two gain constants: proportional(k(p)) and integral(k(i)) gain constant. The dynamics of the PI controller depends on the values of the gain constant used. If gains of these control terms are not selected properly, instability Will occur. Gain tutting methodologies are available to tune these controllers to avoid instability. Hut, these gain tuning strategies and algorithms utilize simplified mathematical model of the plant ut order to obtain gain values. This approach might, not provide optimal gain values for models used in real time digital simulator. In the proposed approach, the algorithm utilizes the step response of the system to obtain optimal gain constants. The plant is modeled using the real time digital simulator (RIDS). A multi-objective optimization formulation is used to find the optimal gain constants. Results are presented here to support the effectiveness of proposed multi-objective gain tutting strategy. (C) 2015, IFAC (International Rderation or Automatic Control) Hosting by Elsevier Ltd. All rights reserved.
Automatic Voltage Regulator (AVR) regulates the generator terminal voltage by controlling the amount of current supplied to the generator field winding by the exciter. Power system stabilizer (PSS) is installed with A...
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ISBN:
(纸本)9783642175626
Automatic Voltage Regulator (AVR) regulates the generator terminal voltage by controlling the amount of current supplied to the generator field winding by the exciter. Power system stabilizer (PSS) is installed with AVR to damp the low frequency oscillations in power system by providing a supplementary signal to the excitation system. Optimal tuning of AVR controller and PSS parameters is necessary for the satisfactory operation of the power system. When applying tuning method to obtain the optimal controller parameters individually, AVR improves the voltage regulation of the system and PSS improves the damping of the system. Simultaneous tuning of AVR and PSS is necessary to obtain better both voltage regulation and oscillation damping in the system. This paper deals with the optimal tuning of AVR controller and PSS parameters in the synchronous machine. The problem of obtaining the optimal controller parameters is formulated as an optimization problem and multi-objective genetic algorithm (MOGA) is applied to solve the optimization problem. The suitability of the proposed approach has been demonstrated through computer simulation in a Single Machine Infinite Bus (SMIB) system.
SoftwareQuality plays a critical role in software development. This paper emphasize on involvement of Kansei Engineering in the field of test case generation. multi-objective genetic algorithm under multi-objective op...
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ISBN:
(纸本)9789380544168
SoftwareQuality plays a critical role in software development. This paper emphasize on involvement of Kansei Engineering in the field of test case generation. multi-objective genetic algorithm under multi-objective optimization methodology is used to generate test cases covering Boolean specific conditions.
A wind turbine transformer (WTT) is designed using a 3D wound core while the transformer's total owning cost (TOC) and its inrush current performance realized as the two objective functions in a multi-objective op...
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ISBN:
(纸本)9781509027057
A wind turbine transformer (WTT) is designed using a 3D wound core while the transformer's total owning cost (TOC) and its inrush current performance realized as the two objective functions in a multi-objective optimization process. multi-objective genetic algorithm is utilized to derive Pareto optimal solutions. The effects of inrush current improvement on other operating and design parameters of the transformer such as: losses, dimensions, and weights are investigated. An approach is presented to select one design from optimal Pareto solutions based on relative improvement of the inrush current performance. Finally, this multi-objective optimum wind turbine transformer design is compared with an optimum transformer design obtained when just TOC is the objective function.
This paper improves an existing Model Based Predictive Control Approach (MBPC), applied for Heating Ventilation and Air Conditioning (HVAC) control in buildings. The existing approach uses the Predictive Mean Vote (PM...
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ISBN:
(纸本)9781479972524
This paper improves an existing Model Based Predictive Control Approach (MBPC), applied for Heating Ventilation and Air Conditioning (HVAC) control in buildings. The existing approach uses the Predictive Mean Vote (PMV) to assess thermal comfort. It has been found that PMV estimation and forecasts deteriorate when the room is occupied. In order to solve this problem, we propose to incorporate measurements of activity inside the room in the predictive models of the inside air temperature. Another improvement to the existing approach is to use an economic cost function, reflecting the money needed for the HVAC control, instead of a cost function related with the consumption of energy.
Supply, manufacture, and distribution of perishable products are challenging jobs in supply chains. Location of warehouses and routing of vehicles are essential issues to distribute perishable products properly. In th...
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To restrain the influences of the nonlinearities and uncertainties in missile servo control systems, the active disturbance rejection control (ADRC) technique is introduced to real-time online estimate and compensate ...
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ISBN:
(纸本)9781479970162
To restrain the influences of the nonlinearities and uncertainties in missile servo control systems, the active disturbance rejection control (ADRC) technique is introduced to real-time online estimate and compensate these factors. As to the problem of the difficulties in tuning ADRC parameters, an improved multi-objective genetic algorithm is adopted to solve the complete set of Pareto solutions for the control parameters, then a multi-criteria decision making algorithm based on utility function is chosen to determine the fittest solution. Then a test platform using TMS320C28346 floating-point DSP as control core is built to verify the research results. The experimental results show that the optimal ADRC parameter is appropriate for the servo control system. The system tracks the input commands smoothly and reliably, and has good robustness and adaptability to nonlinearities and parameters drifts. Also the strategy for tuning the ADRC parameters is practical and feasible.
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