This paper addresses scheduling jobs with non-identical sizes on a single batch-processing machine. Two different multi-objective genetic algorithms (MOGA) have been proposed. The first one is a sequence based MOGA (S...
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This paper addresses scheduling jobs with non-identical sizes on a single batch-processing machine. Two different multi-objective genetic algorithms (MOGA) have been proposed. The first one is a sequence based MOGA (SMOGA) that generates random sequences of jobs and applies the batch first fit heuristic to group the jobs. The second one is a batch based hybrid MOGA (BHMOGA) that generates random batches of jobs and ensures feasibility through using knowledge of the problem. Computational results show that non-dominated solutions obtained by BHMOGA are superior in closeness to the true Pareto-optimal solutions and to keep diversity in the obtained Pareto-set, as the problem size increases.
Since tires carry out many functions and many of them have tradeoffs, it is important to find the combination of design variables that satisfy well-balanced performance in conceptual design stage. To find a good desig...
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Since tires carry out many functions and many of them have tradeoffs, it is important to find the combination of design variables that satisfy well-balanced performance in conceptual design stage. To find a good design of tires is to solve the multi-objective design problems, i.e., inverse problems. However, due to the lack of suitable solution techniques, such problems are converted into a single-objective optimization problem before being solved. Therefore, it is difficult to find the Pareto solutions of multi-objective design problems of tires. Recently, multi-objective evolutionary algorithms have become popular in many fields to find the Pareto solutions. In this paper, we propose a design procedure to solve multi-objective design problems as the comprehensive solver of inverse problems. At first, a multi-objective genetic algorithm (MOGA) is employed to find the Pareto solutions of tire performance, which are in multi-dimensional space of objective functions. Response surface method is also used to evaluate objective functions in the optimization process and can reduce CPU time dramatically. In addition, a self-organizing map (SOM) proposed by Kohonen is used to map Pareto solutions from high-dimensional objective space onto two-dimensional space. Using SOM, design engineers see easily the Pareto solutions of tire performance and can find suitable design plans. The SOM can be considered as an inverse function that defines the relation between Pareto solutions and design variables. To demonstrate the procedure, tire tread design is conducted. The objective of design is to improve uneven wear and wear life for both the front tire and the rear tire of a passenger car. Wear performance is evaluated by finite element analysis (FEA). Response surface is obtained by the design of experiments and FEA. Using both MOGA and SOM, we obtain a map of Pareto solutions. We can find suitable design plans that satisfy well-balanced performance on the map called "multi-performan
There have been widespread applications for multiobjectivegeneticalgorithm (MOGA) on highly complicated optimization tasks in discontinuous, multi-modal, and noisy domains. Because the convergence of MOGA can be re...
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ISBN:
(纸本)038723151X
There have been widespread applications for multiobjectivegeneticalgorithm (MOGA) on highly complicated optimization tasks in discontinuous, multi-modal, and noisy domains. Because the convergence of MOGA can be reached with the non-dominated set approximating the Pareto Optimal front, it is very important to construct the non-dominated set of MOGA efficiently. This paper proposes a new method called Dealer's Principle to construct non-dominated sets of MOGA, and the time complexity is analyzed. Then we design a new MOGA with the Dealer's Principle and a clustering algorithm based on the core distance of clusters to keep the diversity of solutions. We show that our algorithm is more efficient than the previous algorithms, and that it produces a wide variety of solutions. We also discuss the convergence and the diversity of our MOGA in experiments with benchmark optimization problems of three objectives.
This paper describes a non-generational GA for multi-objective optimization problems (MOP) based on a crossover operator called DC (Dislocation Crossover). In it the replacement policy is such that an
This paper describes a non-generational GA for multi-objective optimization problems (MOP) based on a crossover operator called DC (Dislocation Crossover). In it the replacement policy is such that an
The New York city tunnel network problem is a classical case study for water distribution network rehabilitation or upgrading. However, standard problem formulations only offer single solutions based on fixed pressure...
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The New York city tunnel network problem is a classical case study for water distribution network rehabilitation or upgrading. However, standard problem formulations only offer single solutions based on fixed pressure head and demand requirements. This problem is re-examined through the use of multiple criteria optimization and a framework for interpreting these results is proposed. Results from previous studies were closely examined to highlight areas that can be improved. A 6-objective optimization problem was then formulated and results were compared with optimization using a single-objectivegeneticalgorithm (GA) and 2-objectives optimization using a non-dominated sorted geneticalgorithm-II. Although the initial runtime for the 6-objective optimization was long compared with single-objective GA, it provided solutions which span the whole spectrum of possibilities ( in terms of pressure head requirements and cost). It is concluded that the proposed 6-objectives formulation can indeed offer more design choices, hence flexibility, for designers and decision makers.
This paper describes an extension of a method for designing products with built-in disassembly means developed in our previous work, as applied to a realistic example of a desktop computer assembly. Given component ge...
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ISBN:
(纸本)1424400813
This paper describes an extension of a method for designing products with built-in disassembly means developed in our previous work, as applied to a realistic example of a desktop computer assembly. Given component geometries and revenues, the method simultaneously determines, through an optimization process, the spatial configuration of component, locator and fasteners such that the product can be most economically disassembled via a domino-like "self-disassembly" process triggered by the removal of one or a few fasteners. A multi-objective genetic algorithm is utilized to search for Pareto-optimal designs in terms Of four objectives: 1) satisfaction of the distance specification among components, 2) efficient use of locators on components, 3) profit of overall disassembly process, and 4) mass fraction of retrieved components. The method is applied to a simplified model of Power Mac G4 cube (R), and the results inspired a modification to the current design that can improve the ease of disassembly.
In this research, an approach is made to design machine cells using modular-reconfigurable machines to achieve certain characteristics of reconfigurable manufacturing. Each machine considered in the model consists of ...
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ISBN:
(纸本)9783901509469
In this research, an approach is made to design machine cells using modular-reconfigurable machines to achieve certain characteristics of reconfigurable manufacturing. Each machine considered in the model consists of some basic and auxiliary machine modules. By changing the auxiliary modules, different operations can be performed on the machines. A similarity measure among machines based on production flow information and auxiliary module requirement is developed. Machine cells are identified using a multi-objective evolutionary geneticalgorithm for a set of parts with parameters like volumes of production, alternative operation based process plans etc. The two objectives considered are minimization of inter-cell movement and total changes in auxiliary modules for the given production horizon. An illustrative problem and experimental results are given.
This paper presents a computational method for designing an assembly with multiple built-in disassembly pathways, each of which can be activated to retrieve certain components. It is motivated by the global sales of c...
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ISBN:
(纸本)0780394259
This paper presents a computational method for designing an assembly with multiple built-in disassembly pathways, each of which can be activated to retrieve certain components. It is motivated by the global sales of consumer products whose optimal end-of-life options vary geographically due to local recycling/reuse infrastructures and regulatory requirements. Given the sets of components to be retrieved at each location, the method simultaneously determines the spatial configurations of components and locator features, such that each set of desired components is retrieved via a domino-like "self-disassembly" process triggered by the removal of a fastener. A multi-objective generic algorithm is utilized to search for Pareto-optimal designs in terms of the realization of the desired disassembly pathways, the satisfaction of distance specifications among components, the minimization of disassembly cost at each location, and the efficient use of oncomponent locator features. A case study demonstrates the feasibility of the method.
Testing of VLSI circuits can cause generation of excessive heat which can damage the chips under test. In the random testing environment, high-performance CMOS circuits consume significant dynamic power during testing...
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ISBN:
(纸本)0780393635
Testing of VLSI circuits can cause generation of excessive heat which can damage the chips under test. In the random testing environment, high-performance CMOS circuits consume significant dynamic power during testing because of enhanced switching activity in the internal nodes. Our work focuses on the fact that power minimization is a Traveling Salesman Problem (TSP). We explore application of local search and geneticalgorithms to test set reordering and perform a quantitative comparison to previously used deterministic techniques. We also consider reduction of the original test set as a dual-objective optimization problem, where switching activity and fault coverage are the two objective functions.
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