• Title/Summary/Keyword: Reducing Parameter

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Robust Design to the Combined Array with Multiresponse

  • Kwon, Yong-Man
    • Journal of Integrative Natural Science
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    • v.10 no.1
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    • pp.51-57
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    • 2017
  • The Taguchi parameter design in industry is an approach to reducing performance variation of quality characteristic in products and processes. In the Taguchi parameter design, the product array approach using orthogonal arrays is mainly used. It often requires an excessive number of experiments. An alternative approach, which is called the combined array approach, was studied. In these studies, only single response was considered. In this paper we propose how to simultaneously optimize multiresponse for the robust design using the combined array approach.

The Study for Reduction of Stress Concentration at the Stepped Shaft According to Two Types of External Force (하중 종류에 따른 다단축의 응력 집중 완화에 대한 연구)

  • Park, I.S.;Shim, J.J.
    • Journal of Power System Engineering
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    • v.14 no.1
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    • pp.47-52
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    • 2010
  • In this study, Finite Element Analysis have been adopted to analyze reducing stress effect and used to induce the sensitivity of design parameter on various techniques which was used for reducing stress. And so it can be utilized as a data to design on similar model. The effect of reducing stress with respect to change of relief groove radius can be increased by 27.3~18.2 % more than radius of fillet. And if a shoulder fillet radius is larger, additional reducing stress by relief groove radius is not obtained. And there was only little effect on reducing stress by changing the center point of groove radius along horizontal direction. In the case that undercut radius is 1.5mm, Max. Equivalent stress is reduced by 5.71% under bending force and 11.11% under torsion. The best effect of reducing stress at undercut model was yielded when the undercut radius is a forth of difference of stepped shaft radius.

Optimal Path Planning for UAVs to Reduce Radar Cross Section

  • Kim, Boo-Sung;Bang, Hyo-Choong
    • International Journal of Aeronautical and Space Sciences
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    • v.8 no.1
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    • pp.54-65
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    • 2007
  • Parameter optimization technique is applied to planning UAVs(Unmanned Aerial Vehicles) path under artificial enemy radar threats. The ground enemy radar threats are characterized in terms of RCS(Radar Cross Section) parameter which is a measure of exposure to the radar threats. Mathematical model of the RCS parameter is constructed by a simple mathematical function in the three-dimensional space. The RCS model is directly linked to the UAVs attitude angles in generating a desired trajectory by reducing the RCS parameter. The RCS parameter is explicitly included in a performance index for optimization. The resultant UAVs trajectory satisfies geometrical boundary conditions while minimizing a weighted combination of the flight time and the measure of ground radar threat expressed in RCS.

Catchment Responses in Time and Space to Parameter Uncertainty in Distributed Rainfall-Runoff Modeling (분포형 강우-유출 모형의 매개변수 불확실성에 대한 시.공간적 유역 응답)

  • Lee, Gi-Ha;Takara, Kaoru;Tachikawa, Yasuto;Sayama, Takahiro
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.2215-2219
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    • 2009
  • For model calibration in rainfall-runoff modeling, streamflow data at a specific outlet is obviously required but is not sufficient to identify parameters of a model since numerous parameter combinations can result in very similar model performance measures (i.e. objective functions) and indistinguishable simulated hydrographs. This phenomenon has been called 'equifinality' due to inherent parameter uncertainty involved in rainfall-runoff modeling. This study aims to investigate catchment responses in time and space to various uncertain parameter sets in distributed rainfall-runoff modeling. Seven plausible (or behavioral) parameter sets, which guarantee identically-good model performances, were sampled using deterministic and stochastic optimization methods entitled SCE and SCEM, respectively. Then, we applied them to a computational tracer method linked with a distributed rainfall-runoff model in order to trace and visualize potential origins of streamflow at a catchment outlet. The results showed that all hydrograph simulations based on the plausible parameter sets were performed equally well while internal catchment responses to them showed totally different aspects; different parameter values led to different distributions with respect to the streamflow origins in space and time despite identical simulated hydrographs. Additional information provided by the computational tracer method may be utilized as a complementary constraint for filtering out non-physical parameter set(s) (or reducing parameter uncertainty) in distributed rainfall-runoff modeling.

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Study on the Prediction Technique of Vehicle Performance using Parameter Analysis (파라미터 해석을 통한 차량 성능 예측 기법 연구)

  • Kim, Ki-Chang;Kim, Chan-Mook;Kim, Jin-Taek
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2009.10a
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    • pp.647-653
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    • 2009
  • Taguchi parameter design is an approach to reducing performance variation of quality characteristic value in products and processes. Taguchi has used SN (Signal to Noise) ratio to achieve the appropriate set of operating conditions where variability around target is low in the Taguchi parameter design. This paper describes the prediction technique of vehicle performance using parameter analysis to reduce man hour and test development period as well as to achieve stable NVH performance. Design engineer could efficiently decide the design variable using parameter analysis database in early design stage. These improvements can reduce the time needed to develop better vehicles.

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A Study on The Coarse-to-fine Extraction Method of function Patterns by using The Dynamic Quantization of Parameter Space (매개변수공간의 동적 분할 방법에 의한 함수패턴의 단계적 분석 추출에 관한 연구)

  • 김민환;황희영
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.36 no.8
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    • pp.594-602
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    • 1987
  • This paper proposes a new method of reducing the processing time and the size of consummimg memories in Hough transform. In this method, only the functional patterns are considered. The candidate points which are accumulated into the parameter space are computed in a many-to-one fashion and the parameter space is quantized dynamically to maintain a fine precision where it is needed. And a coarse-to-fine extraction method is used to reduce the processing time. The many-to-one fashional computation results in a relatively high-densed accumulation of candidate points around the parameter points corresponding to the image patterns in the image space. So, the dynamic quantization procedure can be simplified and the local maxima can be determined easily. And more effective reduction can be obtained as the dimension of parameter space is increased.

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Alternative Optimization Procedure to Parameter Design (파라미터 설계에 대한 최적화 대체방안)

  • Kwon, Yong-Man;Chang, Duk-Soon
    • Journal of the Korean Data and Information Science Society
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    • v.12 no.1
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    • pp.11-18
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    • 2001
  • Taguchi parameter design is an approach to reducing performance variation of quality characteristic value in products and processes. Taguchi has used signal-to-noise(SN) ratio to achieve the appropriate set of operating conditions where variability around target is low in the Taguchi parameter design. Many statisticians criticize the Taguchi techniques of analysis, particularly those based on SN ratio. In this paper we propose a substantially simpler optimization procedure for parameter design without resorting to SN ratio.

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A PARAMETER ESTIMATION METHOD FOR MODEL ANALYSIS

  • Oh Se-Young;Kwon Sun-Joo;Yun Jae-Heon
    • Journal of applied mathematics & informatics
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    • v.22 no.1_2
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    • pp.373-385
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    • 2006
  • To solve a class of nonlinear parameter estimation problems, a method combining the regularized structured nonlinear total least norm (RSNTLN) method and parameter separation scheme is suggested. The method guarantees the convergence of parameters and has an advantages in reducing the residual norm over the use of RSNTLN only. Numerical experiments for two models appeared in signal processing show that the suggested method is more effective in obtaining solution and parameter with minimum residual norm.

AN EASILY CHECKING CONDITION FOR THE STAVILITY TEST OF A FAMILY OF POLYNOMIALS WITH NONLIMEARLY PERTURBED COEFFICIENTS

  • Kim, Young-Chol;Hong, Woon-Seon
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.5-9
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    • 1995
  • In many cases of robust stability problems, the characteristic polynomial has real coefficients which or nonlinear functions of uncertain parameters. For this set of polynomials, a new stability easily checking algorithm for reducing the conservatism of the stability bound are given. It is the new stability theorem to determine the stability region just in parameter space. Illustrative example show that the presented method has larger stability bound in uncertain parameter space than others.

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On the identification of the multivariable stochastic linear systems (다변수 스토캐스틱 선형 계통의 추정에 관한 연구)

  • 양흥석;남현도
    • 전기의세계
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    • v.31 no.5
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    • pp.361-367
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    • 1982
  • The problem of parameter identification for multivariable stochastic linear systems from output measurements, which are corrupted by noises, is considered. A modified Luenberger's input/output canonical form is used for reducing the number of unknown coefficients. A computationally and conceptionally simple systematic procedure for parameter estimation is obtained using output correlation method. The estimates are shown to be asymptotically normal, unbiased and consistent. Numerical examples are presented to illustrate the identification method.

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