The flexible job shop scheduling problem(FJSP) is an extension of the classic job shop scheduling problem(JSP),which breaks through the uniqueness of limit resources,allows a procedure in many machines processing and ...
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The flexible job shop scheduling problem(FJSP) is an extension of the classic job shop scheduling problem(JSP),which breaks through the uniqueness of limit resources,allows a procedure in many machines processing and one machine processing many kinds of different types of *** is more practical and complex than *** computational complexity of FJSP is much higher,which disables exact solution methods and makes heuristic approaches more qualified.A hybrid optimizationalgorithm,CPSO,based on the cultural algorithm and particle swarm optimization algorithm,is proposed in this paper to solve the *** objective is to minimize *** results show that this hybrid method is able to solve efficiently these kinds of problems.
A novel cultural algorithm based on particleswarmoptimization(PSO) algorithm was proposed in this *** analyzing the partner selection problems of virtual enterprise,the CPSO algorithm was presented to solve enterpri...
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A novel cultural algorithm based on particleswarmoptimization(PSO) algorithm was proposed in this *** analyzing the partner selection problems of virtual enterprise,the CPSO algorithm was presented to solve enterprise alliance problem within reasonable time and *** are certain number partners of each sub-task in virtual enterprise environment. The objective is,by selecting the optimal combination of partners,to minimize project's completion time and project's total cost. We tested the CPSO algorithm against the PSO *** results demonstrate that it can be superior to the regular PSO. We also tested the CPSO algorithm with the exhaustion method to show the algorithm's efficiency.
Combining first-principles calculations with the particleswarmoptimization (PSO) algorithm, we have explored the ground-state structure of Pd2N, whose structure is in debate although it is the first synthesized bi...
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Combining first-principles calculations with the particleswarmoptimization (PSO) algorithm, we have explored the ground-state structure of Pd2N, whose structure is in debate although it is the first synthesized binary platinum group nitride. The ground-state structure is predicted to be tetragonal with space group P^-4m2, which is energetically more favorable than the previously proposed orthorhombic Co2N-type structure. The stability is confirmed by the subsequent calculations on the phonon dispersion curves and elastic constants. Furthermore, the calculated mechanical properties indicate that Pd2N has low incompressibility and is a common hard material.
Although the system reliability theory has a high capability in quality quantification, while system reliability optimization (SRO) has been well developed in manufacturing engineering, seldom can their applications b...
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Although the system reliability theory has a high capability in quality quantification, while system reliability optimization (SRO) has been well developed in manufacturing engineering, seldom can their applications be found in the construction industry. This study aims to develop a system reliability theory based multiple-objective optimization model to conduct SRO, and then identify the cost-quality trade-off solution for construction projects. First the whole construction project is treated as a system composed of different work packages. Second, the reliability function is employed to quantify the quality performance and the nonlinear cost-reliability function is set up. Moreover, according to the physical arrangements among each work package, the system reliability structural function is determined. Third, the total construction cost minimization and system reliability maximization are defined as multiple-objectives. The particle swarm optimization algorithm is employed to search for the Pareto-optimal solutions, from which the final cost-quality trade-off solution can be selected. A real construction case is used to evaluate the workability of the proposed model and the results have fully proven its validity and practicality. (C) 2012 Elsevier B.V. All rights reserved.
The task of setup planning is to determine the number and sequence of setups and the machining features or operations in each setup. Due to the locating method's character, the position of the locators may keep aw...
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The task of setup planning is to determine the number and sequence of setups and the machining features or operations in each setup. Due to the locating method's character, the position of the locators may keep away joining tools from arriving at joining points during the joining process of sheet metal. In order to solve these problems, a novel method is proposed, which consists of three parts: (1) the points on the skin are divided into sets of supplied riveting and prior riveting points by convex hull generating method;(2) fixture vector is defined, and a suitable fixture region is generated by vector multiplication;and (3) the particle swarm optimization algorithm is applied to generate optimal setup scheme by setting up the parameters. The new setup planning approach can accomplish riveting work by minimum setup times and workpiece variation without finite element analysis software. At last, a certain kind of aircraft wing joining process is illustrated as an example to demonstrate the effect of the proposed approach.
Cloud computing environment for the efficient resources allocation is an important issue in the field of cloud computing. The resources in Cloud computing application platform are distributed widely and with great div...
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Cloud computing environment for the efficient resources allocation is an important issue in the field of cloud computing. The resources in Cloud computing application platform are distributed widely and with great diversity. User demands of real-time dynamic change are very difficult to predict accurately. The heuristic ant colony algorithm could be used to solve this kind of problems, but the algorithm has slow convergence speed and parameter selection problems. Aiming at this problem, this paper proposes an optimized ant colony algorithm based on particleswarm to solve cloud computing environment resources allocation problem.
The goal of a unit commitment optimization problem is to reduce the total generation cost as much as possible while satisfying future power demands. Thus, analysis must be performed based on correct predictions of fut...
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The goal of a unit commitment optimization problem is to reduce the total generation cost as much as possible while satisfying future power demands. Thus, analysis must be performed based on correct predictions of future demands. However, various uncertain factors affect these loadsmaking an exact forecasting unsuccessful. This study mitigates this difficulty by applying fuzzy set theory to evaluate the future uncertain loads. The objective of this research is to build a two-stage multi-objective fuzzy programming model based on 24-hour uncertain load forecasting. The first stage is a decision-making process on the interval data of the imprecise power loads, whereas the second stage pursues the optimization of the unit commitment scheduling, which can help find both optima simultaneously by maximizing power supply reliability and minimizing total generation cost. To define the supply reliability under uncertain forecasting, we propose a new concept of maximal blackout time during successful operation, which is based on the fuzzy credibility theory. Furthermore, as a solution approach to this model, an improved two-stage multi-objective particle swarm optimization algorithm is designed based on our previous studies. Finally, the performance of this algorithm is discussed in comparison with experimental results from several test systems.
Stocks diversity is the precondition for ensuring the convergence of PSO algorithm. The definition of stocks diversity is clear and the operand is small, moreover which was analyzed by particle evolution degree and ag...
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Stocks diversity is the precondition for ensuring the convergence of PSO algorithm. The definition of stocks diversity is clear and the operand is small, moreover which was analyzed by particle evolution degree and aggregation degree. A changed algorithm was proposed based on adjusting weight adaptively. The algorithm ensures population diversity and avoids premature convergence effectively. Simulation results indicate that this algorithm not only speeds up the population the evolution speed, but also strengthens the algorithm the overall situation astringency, and convergence of probability also increases from 15% to 100%.
Multicropping is the practice of growing two or more crops in the same space during a single growing season. Planning rules are mathematical equations that use previous experiences of a water resource system to balanc...
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Multicropping is the practice of growing two or more crops in the same space during a single growing season. Planning rules are mathematical equations that use previous experiences of a water resource system to balance the system's water supply and demand, and calculate multicrop areas in various periods. In this paper, linear and nonlinear planning rules are developed for optimal multicrop irrigation areas associated with reservoir operation policies in a reservoir-irrigation system. Reservoir operations are related to water allocations to each irrigated area by considering inflow and storage volume of the reservoir as the water supply in a monthly operation period. Evolutionary algorithms (EAs) can determine optimal multicropping patterns planning rules by considering various mathematical patterns. In this paper, three EAs, namely, (1) genetic algorithm (GA), (2) particleswarmoptimization (PSO), and (3) shuffled frog leaping algorithm (SFLA) are employed and compared to maximize the total net benefit of the water resource system by supplying irrigation water for a proposed multicropping pattern over the planning horizon. Results show that the SFLA achieves the best solution, with the maximum value of the objective function in both linear and nonlinear planning rules compared to the GA and PSO. Moreover, the best yield of nonlinear rules is 45.52% better (higher) than that obtained by linear rules. (C) 2013 American Society of Civil Engineers.
In order to effectively eliminate the noise and extract the impulse components in the vibration signals, a new method based on an optimal multiscale morphological filter is proposed. In this method, firstly, the avera...
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In order to effectively eliminate the noise and extract the impulse components in the vibration signals, a new method based on an optimal multiscale morphological filter is proposed. In this method, firstly, the average of the closing and opening operator is used to construct the morphological filter, then the multiscale morphological filters' structure elements (SEs) are optimized and selected using a particle swarm optimization algorithm (PSO). The noise in the original signal is filtered by the multiscale morphological filter. The proposed method was evaluated by simulated signals and bearing fault signals. The results show that the method can effectively filter the noise and extract the impulse characteristics of the vibration signals, which demonstrate the effectiveness of the proposed method.
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