Increasing demands on precision manufacturing of complex free-form surface parts have been observed in the past several years. Although some advanced techniques have been employed to solve the design and machining pro...
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Increasing demands on precision manufacturing of complex free-form surface parts have been observed in the past several years. Although some advanced techniques have been employed to solve the design and machining problems for such parts, quality inspection remains a difficult problem. Registration is a crucial issue in surface inspection;it is used to transform the design model and measurement model into a common coordinate system. The comparison results are then outputted in a report and displayed visually by color gradients. This paper presents a design model-based inspection method with range image registration, in which the measurement model is represented by a series of 3D discrete points. In the model preprocessing, the directed Hausdorff distance (DHD) method is employed for point cloud simplification, and a novel point descriptor is designed to evaluate the property of each point. Subsequently, a differentialevolution (DE) algorithm-based optimizer is proposed for error evaluation. Combined with the properties of 3D points, the optimizer can measure the similarity between the design model and the measurement model with a recursive process. The proposed algorithms have been implemented and tested with several sets of simulated and real data. The experiment results illustrate that they are effective and efficient for free-form surface part quality inspection.
Considering that the model of the p-Xylene (PX) oxidation reaction process is a hybrid and highly nonlinear model, a differential evolution algorithm with self-adaptive mutation strategy and control parameters (SSCPDE...
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Considering that the model of the p-Xylene (PX) oxidation reaction process is a hybrid and highly nonlinear model, a differential evolution algorithm with self-adaptive mutation strategy and control parameters (SSCPDE) was proposed to optimize the operating conditions. In SSCPDE, each individual has its own control parameters and mutation strategies that can be self-adaptively adjusted to different evolution phases and various optimization problems. SSCPDE was compared with 6 state-of-the-art DE variants by 38 different types of benchmark functions. Simulation results show that the average performance of SSCPDE is better than the six famous self-adaptive DE algorithms. Finally, the SSCPDE algorithm was used to optimize the five main operating conditions of the PX oxidation reaction process. Optimization results indicate that the production cost, loss of acetic acid and PX combustion of the PX oxidation reaction process are greatly reduced and that SSCPDE performs better than JADE, EPSDE, SaDE, and the optimizer of Aspen Plus and similar to jDE and CoDE.
A basic problem in the design of a decision support system for ship collision avoidance is path optimization in a complex and dynamic navigational environment. This paper introduces a new path planning method based on...
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A basic problem in the design of a decision support system for ship collision avoidance is path optimization in a complex and dynamic navigational environment. This paper introduces a new path planning method based on the differentialevolution (DE) algorithm to calculate a safe, optimal path for a ship. The algorithm was tested on a set of traffic scenarios typically encountered in open waters. The simulation test results prove the method's ability to solve a path planning problem for ships. We also discuss the optimality, consistency, and performance of the algorithm and provide a comparison of this algorithm with the particle swarm optimization (PSO) algorithm. The comparison results clearly show a significant advantage of the DE algorithm over the PSO algorithm in the areas of output optimality, algorithm consistency, and execution efficiency.
Considering that it is difficult to set suitable penalty factors for the penalty function method, which is one of the most important ways to solve constrained optimization problems, and that the quality of obtained op...
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Considering that it is difficult to set suitable penalty factors for the penalty function method, which is one of the most important ways to solve constrained optimization problems, and that the quality of obtained optimal solution mainly depends on the optimization algorithm's performance and handling constraints capacity, a novel differential evolution algorithm with co-evolution of control parameters and penalty factors, named as CoE-DE, is proposed. In CoE-DE, differentialevolution operator is applied for evolving the original individuals, which consist of optimal variables. To improve the performance of CoE-DE and the handling constraints capacity, Alopex algorithm is used to co-evolve the symbiotic individuals, which consist of two DE control parameters and the penalty factors. To illustrate the whole performance of CoE-DE, several algorithms are applied to solve 13 benchmark functions and five constrained engineering problems. The results show that the performance of CoE-DE is better than SR algorithm and similar to a SIMPILE in 13 benchmark functions, and the satisfactory result is obtained in five constrained engineering problems. Copyright (C) 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
In the fed-batch cultivation of Saccharomyces cerevisiae,excessive glucose addition leads to increased ethanol accumulation,which will reduce the efficiency of glucose utilization and inhibit product *** glucose addit...
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In the fed-batch cultivation of Saccharomyces cerevisiae,excessive glucose addition leads to increased ethanol accumulation,which will reduce the efficiency of glucose utilization and inhibit product *** glucose addition limits cell *** properly regulate glucose feed,a different evolutionalgorithm based on self-adaptive control strategy was proposed,consisting of three modules(PID,system identification and parameter optimization).Performance of the proposed and conventional PID controllers was validated and compared in simulated and experimental *** the simulation,cultivation with the self-adaptive control strategy had a more stable glucose feed rate and concentration,more stable ethanol concentration around the set-point(1.0 g·L^(-1)),and final biomass concentration of 34.5 g-DCW·L^(-1),29.2%higher than that with a conventional PID control *** the experiment,the cultivation with the self-adaptive control strategy also had more stable glucose and ethanol concentrations,as well as a final biomass concentration that was 37.4%higher than that using the conventional strategy.
Reserve services are an essential part of a standard market design and are under development in major electricity markets. This paper presents the development of differential evolution algorithm for optimal allocation...
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Reserve services are an essential part of a standard market design and are under development in major electricity markets. This paper presents the development of differential evolution algorithm for optimal allocation of energy and spinning reserve. The optimization is performed in an integrated market with biddable spinning reserve and sectional price offer curves while considering all security and power systems constraints in steady state and system credible contingencies. The effectiveness of the proposed method is examined by application of the proposed algorithm on the IEEE 30-bus test system. Some comparisons are made with analytical and evolutionary methods in various cases.
Background: This paper presents dynamic performance analysis of isolated wind-diesel power system. A dual mode controller is proposed for pitch control of wind turbine generator. Methods: The parameters of the control...
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Background: This paper presents dynamic performance analysis of isolated wind-diesel power system. A dual mode controller is proposed for pitch control of wind turbine generator. Methods: The parameters of the controller are optimized by differentialevolution (DE) algorithm. The hybrid model was simulated with the proposed load frequency controller (LFC) by considering step load perturbation. The minimization of time multiplied integral of absolute error is considered as the objective function. The performance of the proposed controller is compared with the published result of the optimal controller. Further, the performance of the system is investigated by incorporating Super Conducting Magnetic Energy Storage (SMES) and Fuel Cell (FC). Also, the dynamic performance is investigated for changing step load perturbations. Furthermore, the response of the system is analyzed towards random loading. Results: Finally, sensitivity analysis is done by varying the system parameters and operating conditions from their nominal values. Conclusion: The simulation results show that the proposed dual mode DE optimized controller gives better transient and steady state response.
A novel differential evolution algorithm (DEA) is applied directly to the DC power flow-based model in order to efficiently solve the problems of static and multistage transmission expansion planning (TEP). The purpos...
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A novel differential evolution algorithm (DEA) is applied directly to the DC power flow-based model in order to efficiently solve the problems of static and multistage transmission expansion planning (TEP). The purpose of TEP is to minimise the transmission investment cost associated with the technical operation and economical constraints. Mathematically, long-term TEP using the DC model is a mixed integer nonlinear programming problem that is difficult to solve for large-scale real-world transmission networks. In addition, the static TEP problem is considered both with and without the resizing of power generation in this research. The efficiency of the proposed method is initially demonstrated via the analysis of low, medium and high complexity transmission network test cases. The analysis is performed within the mathematical programming environment of MATLAB using both DEA and conventional genetic algorithm and a detailed comparative study is presented.
In this paper, differentialevolution (DE), one of the youngest paradigms in evolutionary computation, is applied to the process of synthesizing a planar array factor focused on sidelobe-level reduction. Sidelobe leve...
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In this paper, differentialevolution (DE), one of the youngest paradigms in evolutionary computation, is applied to the process of synthesizing a planar array factor focused on sidelobe-level reduction. Sidelobe level is a critical array factor parameter in the task of reducing background noise and interference in the most recent Wireless Communications Systems. Minimization of sidelobe level involves nonlinear and non-convex dependence between array factor and its elements parameters becoming a highly complex problem. However, DE has proven to be a fast and efficient algorithm for complex real-valued problems. Subsequently, a binary-coded genetic algorithm is proposed for the synthesis of planar arrays. Numerical results show a promising performance ofDE reducing noticeably the sidelobe level generated by a uniform planar array. (C) 2006 Elsevier GmbH. All rights reserved.
In this paper, the model of RLP which in the multi-project environment is expanded to the RLPMP using the minimum of the variance of total resource consumption within unit time for all projects as the optimization obj...
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In this paper, the model of RLP which in the multi-project environment is expanded to the RLPMP using the minimum of the variance of total resource consumption within unit time for all projects as the optimization objective. In order to ensure the optimal individual will not be destroyed by operations such as crossover or variation and still maintain convergence of differential evolution algorithm, we try to introduce the elitist reservation to the differential evolution algorithm. Case analysis showed that the improved differential evolution algorithm can solve the model of RLPMP and then improve the balance of multi-project resources effectively.
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