• Title/Summary/Keyword: optimizing

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A Hybrid Genetic Algorithm for Optimizing Torch Paths to Cut Stock Plates Nested with Open Contours (열린 윤곽선 부재로 이루어진 판재의 절단가공경로 최적화를 위한 혼합형 유전알고리즘)

  • Lee, Moon-Kyu
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.33 no.3
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    • pp.30-39
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    • 2010
  • This paper considers a problem of optimizing torch paths to cut stock plates nested with open contours. For each contour, one of the two ending points is to be selected as a starting point of cutting with the other being the exit point. A torch path is composed of a single depot and a series of starting and ending points of contours to be cut. The torch path optimization problem is shown to be formulated as an extended version of the standard travelling salesman problem. To solve the problem, a hybrid genetic algorithm with the local search of torch paths is proposed. The genetic algorithm is tested for hypothetical problems whose optimal solutions are known in advance due to the special structure of them. The computational results show that the algorithm generates very near optimal solutions for most cases of the test problems, which verifies the validity of the algorithms.

Development and Application of Calibration Interval Analysis Program for Measurement Quality and Reliability Improvement (측정 품질과 신뢰도 향상을 위한 교정주기 분석 프로그램의 개발 및 응용)

  • Park, Byoung-Sun;Ahn, Ung-Hwan;Cho, Joong-Jae
    • Journal of Korean Society for Quality Management
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    • v.34 no.1
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    • pp.54-72
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    • 2006
  • In recent years, the widespread application of quality management and measurement reliability has put increasing emphasis on procedures for periodic instrument calibration. By optimizing calibration intervals, unnecessary calibrations can be minimized, thereby reducing costs. Moreover, optimizing intervals will improve compliance with regulatory directives while ensuring maximal compliance with reliability targets. In this paper, we present Calibration Interval Analysis Program developed using several establishment methodologies of calibration interval for measurement quality and reliability improvement. Also, we perform calibration interval analysis for some measurement instruments and analyse its results.

A Study on the Optimum Design of Multi-Object Dynamic System for the Rail Vehicle (철도차량 동적 진동특성을 고려한 다목적함수 최적설계)

  • Park, Chan-Kyoung;Lee, Kwang-Ki;Kim, Ki-Hwan;Hyun, Seung-Ho;Park, Choon-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.894-899
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    • 2000
  • Optimization of 26 design variables selected from suspension characteristics for Korean High Speed Train (KHST) is performed according to the minimization of 58 responses which represent running safety and ride comfort for KHST and analyzed by using the each response surface model from stochastic design experiments. Sensitivity of design variables is also analyzed through the response surface model which ineffective design prameters to the performance index are screened by using stepwise regression method. The response surface models are used for optimizing design variables through simplex algorism. Values of performance index simulated by optimized design parameters are totally lower than those by initial design parameters. It shows that this method is effective for optimizing multi-design variables to multi-object function.

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Optimization of Conditions for Extractive Ethanol Fermentation in an Aqueous Two Phase System (수성이상계 에탄올 추출발효 조건의 최적화에 관한 연구)

  • 김진한;허병기;목영일
    • Microbiology and Biotechnology Letters
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    • v.22 no.5
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    • pp.531-537
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    • 1994
  • This study was undertaken with objective of optimizing the conditions of fermentation in an aqueous two-phase system which is composed of polyethylene glycol (PEG) 20000 and crude dextran (Dx). The data were obtained and analyzed using the Box-Wilson's experimental design protocol and the response surface methodology. To reach this end a multilinear polynomial regres- sion model was developed, which can be utilized for the purpose of optimizing the extractive fermentation. Optimum conditions for batch fermentation with aqueous two phase system were found to be at 4.2~5.4% PEG/3.2~4.2% Dx range. The composition of the center was 4.8% PEG/ 3.6% Dx. Optimum operating conditions for initial sugar concentration and fermentation time were approximately 160 g/l, and 21~22 hr, respectively. Fermentation in the aqueous two phase system composed of 5% PEG/4% Dx showed increase of 23% in ethanol concentration, of 9.5% in ethanol yield, and of 19% in ethanol productivity as compared to the case of fermentation of neat Jerusalem artichoke juice.

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Optimizing Design of Side Airbag Inflator using DOE Method (실험계획법을 이용한 측면 에어백 인플레이터 최적 설계)

  • Kim, Byeong-Woo;Hu, Jin
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.10
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    • pp.1189-1195
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    • 2011
  • For side airbag, the pipe type inflators have been wide used while the disk type inflators have been used for front airbag. For helping to prevent injury and death the airbag inflator system should be design with great care. The present study deal with optimizing the design of side airbag inflator by finite element analysis and design of experiment method. An optimization process was integrated to determine the optimum design variable values related to the side airbag inflator. Free shape optimization method has been carried out to find a optimal shape on an side airbag inflator model. Optimization of the air bag inflator was successfully developed using Sharpe optimization was carried out to find a new geometry. The improved results compared to the base design specification were achieved from design of experiment and optimization.

Modeling Intersections and Other Structures for Highway Alignment Optimization (교차로와 구조물을 고려한 도로선형 최적화 모형 개발)

  • 김응철
    • Proceedings of the KOR-KST Conference
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    • 2003.02a
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    • pp.21-71
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    • 2003
  • Previous alignment optimization models have not adequately considered intersections and other structures such as bridges, tunnels, grade separations and interchanges which can very strongly affect alignment decisions. This paper develops comprehensive cost functions for intersections and other structures and incorporates them in recently developed highway alignment optimization models connected with genetic algorithms and geographical information systems. The result is a fast and computerized process for extracting, analyzing spatial data, evaluating candidate alignments and optimizing them. A method for locally optimizing intersections is also developed. It improves search flexibility by saving good alignments whose unacceptable crossing angles with existing roads can be fixed, Through case studies, the developed model is found to produce feasible and efficient solutions.

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Optimizing Oily Wastewater Treatment Via Wet Peroxide Oxidation Using Response Surface Methodology

  • Shi, Jianzhong;Wang, Xiuqing;Wang, Xiaoyin
    • Journal of the Korean Chemical Society
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    • v.58 no.1
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    • pp.80-84
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    • 2014
  • The process of petroleum involves in a large amount of oily wastewater that contains high levels of chemical oxygen demand (COD) and toxic compounds. So they must be treated before their discharge into the receptor medium. In this paper, wet peroxide oxidation (WPO) was adopted to treat the oily wastewater. Central composite design, an experimental design for response surface methodology (RSM), was used to create a set of 31 experimental runs needed for optimizing of the operating conditions. Quadratic regression models with estimated coefficients were developed to describe the COD removals. The experimental results show that WPO could effectively reduce COD by 96.8% at the optimum conditions of temperature $290^{\circ}C$, $H_2O_2$ excess (HE) 0.8, the initial concentration of oily wastewater 3855 mg/L and reaction time 9 min. RSM could be effectively adopted to optimize the operating multifactors in complex WPO process.

Optimum Design of Reinforced Concrete frames Considering Serviceability (사용성을 고려한 RC뼈대 구조물의 최적설계)

  • 김기대;박성규
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.10a
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    • pp.279-286
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    • 2002
  • This study is concerned wiか the practical optimum design of concrete framed structures considering serviceability - deflection, crack, fatigue. The optimizing problems of framed structure are formulated with the objective function and the constraints which take the section properties as the design variables. The objective functions are formulated as the total cost of the structures and the constraints are derived by using the criteria with respect to safety and serviceability based on the part of concrete bridge in the Korea standard code of road bridge. The SLP method is introduced to solve the formulated nonlinear programming problems in this study and tested out through the numerical examples. This developed optimizing algorithm is tested out and examined through the numerical examples for the practical use of design on the concrete framed structures. And their results are compared and analyzed to examine the possibility of optimization, the applicability and the convergency of this algorithm.

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Analysis of Variance for Using Common Random Numbers When Optimizing a System by Simulation and RSM (시뮬레이션과 RSM을 이용한 시스템 최적화 과정에서 공통난수 활용에 따른 분산 분석)

  • 박진원
    • Journal of the Korea Society for Simulation
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    • v.10 no.4
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    • pp.41-50
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    • 2001
  • When optimizing a complex system by determining the optimum condition of the system parameters of interest, we often employ the process of estimating the unknown objective function, which is assumed to be a second order spline function. In doing so, we normally use common random numbers for different set of the controllable factors resulting in more accurate parameter estimation for the objective function. In this paper, we will show some mathematical result for the analysis of variance when using common random numbers in terms of the regression error, the residual error and the pure error terms. In fact, if we can realize the special structure of the covariance matrix of the error terms, we can use the result of analysis of variance for the uncorrelated experiments only by applying minor changes.

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Processibility of High Ductile Fiber-Reinforced ECCs (Engineered Cementitious Composites) (고인성 섬유복합재료 ECC (Engineered Cementitious Composite)의 시공성)

  • Kim Yun Yong;Kim Jeong-Su;Kim Jin-Keun;Ha Gee-Joo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05b
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    • pp.313-316
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    • 2005
  • In the recent design of high ductile fiber-reinforced cementitious composite ECC, which exhibits tensile strain-hardening behavior in the hardened state, optimizing both processing mechanical properties for specific applications is critical. This study introduced a method to develop useful ECCs in field, which possess the different fluid properties to facilitate diverse types of processing (i.e., self-consolidating or spray processing). Control of rheological modulation was regarded as a key factor to allow the performance of the desired processing, while retaining the ductile material properties. To control the rheological properties of the composite, we first determined basic ECC compositon, which is based on micromechanics and steady-state cracking theory. The stability and consequent viscosity of suspensions were, then, mediated by optimizing dosages of chemical and mineral admixtures. The rheological properties altered by this approach were revealed to be effective in obtaining ECC hardened properties, allowing us to readily achieve the desired function of the fresh ECC.

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