• Title/Summary/Keyword: 실험계획표

Search Result 116, Processing Time 0.03 seconds

Process Design of a Hot Forged Product Using the Artificial Neural Network and the Statistical Design of Experiments (신경망과 실험계획법을 이용한 열간 단조품의 공정설계)

  • 김동환;김동진;김호관;김병민;최재찬
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.15 no.9
    • /
    • pp.15-24
    • /
    • 1998
  • In this research. we have proposed a new technique to determine .the combination of design parameters for the process design of a hot forged product using artificial neural network(ANN) and statistical design of experiments(DOE). The investigated problem involves the adequate selection of the aspect ratio of billet, the ram velocity and the friction factor as design parameters. An optimal billet satisfying the forming limitation, die filling, load and energy as well as more uniform distribution of effective strain, is determined by applying the ability of artificial neural network and considering the analysis of mean and variation on the functional requirement. This methodology will be helpful in designing and controlling parameters on the shop floor which would yield the best design solution.

  • PDF

A Study on the Optimization of Ply Angles for Composite Tube using Design of Experiments (실험계획법을 이용한 복합재 경통 적층각의 최적 설계에 관한 연구)

  • Park, Byong-Ug;Seo, Yu-Deok;Kim, Hyun-Jung;Youn, Sung-Kie;Lee, Seung-Hoon;Lee, Deog-Gyu;Lee, Eung-Shik;Chang, Su-Young
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.37 no.7
    • /
    • pp.627-633
    • /
    • 2009
  • Composite has become one of the most frequently used material for a tube of satellite camera due to its attractive characteristics. However, laminated composites can be weakened by delamination which comes from interlaminar stress. Such failure mode cause structural instability of the camera as well as degradation of optical quality. Therefore composite tube should be robust in delamination. Also, composite tube should have high stiffness, sufficient high natural frequency and small coefficient of thermal expansion. The design procedures presented in this paper are based on design of experiments. The experiments for mechanical analysis are designed by the tables of orthogonal arrays. In order to manipulate the various mechanical properties systematically, multiple-attribute decision making(MADM) is employed. Through analysis of variance and F-test, the critical design variables which have dominant influences on mechanical performance are determined. Finally improved ply angles for composite tube are determined.

Crew Schedule Optimization by Integrating Integer Programming and Heuristic Search (정수계획법과 휴리스틱 탐색기법의 결합에 의한 승무일정계획의 최적화)

  • Hwang, Jun-Ha;Park, Choon-Hee;Lee, Yong-Hwan;Ryu, Kwang-Ryel
    • Journal of KIISE:Computing Practices and Letters
    • /
    • v.8 no.2
    • /
    • pp.195-205
    • /
    • 2002
  • Crew scheduling is the problem of pairing crews with each of the vehicles in operation during a certain period of time. A typical procedure of crew schedule optimization consists of enumerating all possible pairings and then selecting the subset which can cover all the operating vehicles, with the goal of minimizing the number of pairings in the subset. The linear programming approach popularly adopted for optimal selection of pairings, however, is not applicable when the objective function cannot be expressed in a linear form. This paper proposes a method of integrating integer programming and heuristic search to solve difficult crew scheduling problems in which the objective function cannot be expressed in linear form and at the same time the number of crews available is limited. The role of heuristic search is to improve the incomplete solution generated by integer programming through iterative repair. Experimental results show that our method outperforms human experts in terms of both solution quality and execution time when applied to real world crew scheduling Problems which can hardly be solved by traditional methods.

Development of an Optimization Algorithm Using Orthogonal Arrays in Discrete Space (직교배열표를 이용한 이산공간에서의 최적화 알고리즘 개발)

  • Yi, Jeong-Wook;Park, Joon-Seong;Lee, Kwon-Hee;Park, Gyung-Jin
    • Proceedings of the KSME Conference
    • /
    • 2001.06c
    • /
    • pp.408-413
    • /
    • 2001
  • The structural optimization is carried out in the continuous design space or discrete design space. Methods for discrete variables such as genetic algorithms are extremely expensive in computational cost. In this research, an iterative optimization algorithm using orthogonal arrays is developed for design in discrete space. An orthogonal array is selected on a discrete design space and levels are selected from candidate values. Matrix experiments with the orthogonal array are conducted. New results of matrix experiments are obtained with penalty functions for constraints. A new design is determined from analysis of means(ANOM). An orthogonal array is defined around the new values and matrix experiments are conducted. The final optimum design is found from iterative process. The suggested algorithm has been applied to various problems such as truss and frame type structures. The results are compared with those from a genetic algorithm and discussed.

  • PDF

A Study on Performance Improvement of Diaphgram for Micro Speaker using Table of Orthogonal Array (직교배열표를 이용한 마이크로 스피커용 다이아프램의 성능개선에 관한 연구)

  • 홍도관;우병철;안찬우
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2004.10a
    • /
    • pp.162-165
    • /
    • 2004
  • On this study, we improved diaphgram for micro speaker performance using Taguchi method in discrete design space. The design of diaphgram has an effect on performance of micro speaker such as, thickness of diaphgram, shape of diaphgram, etc. Therefore this study carried to decide shape of diaphgram and thickness of diaphgram for minimizing 2nd natural frequency of diaphgram using Taguchi method. we showed improved design factors that minimized 2nd natural frequency of diaphgram. Also, 2nd natural frequency of diaphgram for micro speaker is reduced up to 37 percent maintaining twist mode shape. From the results of ANOVA, 2nd natural frequency of diaphgram for micro speaker have an effect on position of the outer curved shape and thickness of diaphgram.

  • PDF

Optimization of a Gate Valve using Orthogonal Array and Kriging Model (직교배열표와 크리깅모델을 이용한 게이트밸브의 최적설계)

  • Kang Jin;Lee Jong-Mun;Kang Jung-Ho;Park Hee-Chun;Park Young-Chul
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.23 no.8 s.185
    • /
    • pp.119-126
    • /
    • 2006
  • Kriging model is widely used as design DACE(analysis and computer experiments) model in the field of engineering design to accomplish computationally feasible design optimization. In this paper, the optimization of gate valve was performed using Kriging based approximation model. The DACE modeling, known as the one of Kriging interpolation, is introduced to obtain the surrogate approximation model of the function. In addition, we describe the definition, the prediction function and the algorithm of Kriging method and examine the accuracy of Kriging by using validation method.

An Experimental Study on Steering Performance of Tracked Vehicle on Deep-sea Cohesive Soft Soil by DOE using Orthogonal Arrays (직교배열표 실험계획법에 의한 심해저 점착성 연약지반용 무한궤도차량의 선회성능에 대한 실험 연구)

  • Choi, Jong-Su;Hong, Sup;Kim, Hyung-Woo
    • Journal of Ocean Engineering and Technology
    • /
    • v.20 no.4 s.71
    • /
    • pp.37-42
    • /
    • 2006
  • This paper is concerned with experimental investigation of steering performance of a tracked vehicle on extremely soft soil. A tracked vehicle model with principal dimensions of 0.9 m(L)x0.75 m(B)x0.4 m(H) and weight of 167 kg was constructed with a pair of driving chain links, driven by two AC-servo motors. The tracks were configured with detachable grousers with variable span. A deep seabed was simulated by means of a bentonite-water mixture in a soil bin of 6.0 m(L)x3.7 m(B)x0.7 m(H). The turning radii of vehicle and driving torques of motors were measured with respect to experiment variables: steering ratio, driving speed, grouser chevron angle, grouser span, and grouser height. L8 orthogonal table is adopted for DOE (Design of experiment). The effects of experiment variables on steering performance are evaluated.

An Experimental Study on the Automatic Coding System for Statistical Information Classification in Korea (통계정보 분류의 자동코딩 성능 실험 연구)

  • Nam, Young-Jun;Ahn, Dong-Ein
    • Journal of the Korean Society for information Management
    • /
    • v.17 no.4
    • /
    • pp.27-45
    • /
    • 2000
  • National statistical data such as Korean Census is fundamental data for national administration. In this paper, we present an automatic coding system utilizing morphological analyser and knowledge dictionaries. Knowledge bases are constructed based on an authority dictionaries which were developed by authors utilizing a newly learning theory. Test data indicates 99.5% of productivity and 83.3% of accuracy. The presented methods can be effectively applied to analyze statistical information.

  • PDF

Barrel Rifling Shape Optimization by Using Design of Experiment Approach (실험계획법을 적용한 포의 강선 형상최적설계)

  • Kang, Dae-Oh;Woo, Yoon-Hwan;Cha, Ki-Up
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.36 no.8
    • /
    • pp.897-904
    • /
    • 2012
  • The rifling design problem has continuous-type shape variables and an integral number of riflings. In addition, it requires considerable time for analysis because its behavior should be described by a nonlinear finite element model (FEM). Therefore, this study presents an efficient design process for rifling based on a design of experiment (DOE) approach. First, Bose's orthogonal array is used to represent 25 runs for four design variables including three shape variables and one integer variable. Then, nonlinear FE analyses are performed. Next, to minimize the bullet resistance without affecting the bullet velocity and bullet rotational angle immediately before a bullet leaves the gun barrel, a what-if design is performed. In the proposed what-if design, a functional including the design objective and constraints is constructed and effect analysis is performed by using the functional. It is found that the new design obtained from the what-if design shows better results than the current one.

Plane Experiment Study on Drainage Capacity of Sluice Gate by Slope and Length of Apron (Apron 경사 및 길이에 따른 수문구조물 배수능 평면실험 연구)

  • Yoon, Kwang-Seok;Yeo, Kyu-Dong
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2005.05b
    • /
    • pp.1031-1035
    • /
    • 2005
  • 조력발전 건설사업에서 우선적으로 고려되어야 할 사항은 조수간만에 의해 외해부와 조지부 사이를 이동하는 해수를 적절히 소통시키는 것이다. 즉, 조력발전소에서 수문구조물의 목적은 주어진 조건 하에서 계획된 유량을 충분히 그리고 안전하게 배제시키는 것이다. 본 연구에서는 수문구조물에 대한 Apron의 길이와 경사의 변화에 의한 외해 조위와 시화호 수위차 조건에 따른 유량계수를 구해 배수능력과 유$\cdot$출입부, 외해, 시화호 및 큰가리섬 주위의 흐름 특성을 검토하고자 하였다. 이를 위해 시화호를 실험대상으로 하여 구조물을 중심으로 외해측으로 1,000m, 시화호측으로 500m, 폭 1,500m의 범위를 선정하였다. 수리모형을 1대50의 축척비로 제작하였다. 표 1은 실험별 Apron과 수문구조물의 제원을 나타내며, 수문구조물은 7기로 이루어졌다. 시화호의 흐름은 관성력과 중력이 지배력이 되며, 이때 상사법칙은 Froude 상사법칙을 적용할 수 있다. 실험III은 실험II에서 Apron의 경사를 1대10에서 1대5로 수정한 실험으로 수위조건은 외해측 -2.530 EL.m이고, 시화호측은 -1.603EL.m이다. 유량계수를 산정하기 위하여 6개 실험조건을 기본계획에서 제시된 수위-조위 조건에서 수위차 및 통수유량을 분배하여 결정하였고 유량계수 산정식에 따라 구조물의 유입부와 유출부에서 유속-면적법에 의해서 유량을 측정하였다. 그리고 국부평면 실험모형에서의 전체적인 해류의 흐름을 분석하기 위해 2차원 유속을 측정하였다. 또한, 유$\cdot$출입부 안정성을 검토하기 위해 Apron 지점과 수문구조물 지점에 3점법으로 유속을 측정하였으며, 색소를 이용하여 유황을 관찰하였다. 시화호와 외해의 수위차가 1.011 m일 때의 전체 수문구조물을 통과하는 유량을 비교한 결과, 실험II 및 실험III의 통과유량은 각각 $10,924m^3/s$$10,075m^3/s$로서 실험 I의 $2,757m^3/s$에 비해 통수능이 많이 개선되었음을 알 수 있다.

  • PDF