• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계 학술대회논문집(수송기계편)
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• pp.134-139
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• 2005

This paper presents a robust design of vehicle interior noise using Taguchi method and a substructure synthesis method with a hybrid model. Firstly, the proposed method identifies the critical process of the concerned interior noise through a TPA (Transfer Path Analysis). Secondly, a strategy for a robust design is discussed, in which the major noise factor among uncertainties in the process is quality distribution of rubber bushes connecting a cradle and a trimmed body. Thirdly, a virtual test model fer the process is developed by applying a substructure synthesis method with a hybrid modeling approach. Fourthly, virtual tests are carried out according to the predefined tables of orthogonal array in Taguchi robust design process. The process was performed under 2 sub-steps. The first step is sensitivity analysis of 31 panels, and the other step is weight optimization of mass dampers on sensitive panels. Finally, two vehicles with the proposed countermeasures were validated. The proposed method reduces 87.5% of trials of measurements due to the orthogonal arrays and increases robustness by 8.6dB of S/N ratio and decreases $5\;dB(A){\sim}10\;dB(A)$ of interior noise in the concerned range of RPM.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권2호
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• pp.125-133
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• 2016

Purpose: The purpose of this study is to evaluate durability of platform safety step system in railway. Method: We performed finite element analysis & durability analysis of platform safety step system with VPD (Virtual Product Development) techniques and examined the durability standard & qualification life through the rig test during no failure test time in reliability qualification test. We continued to test 1 million cycles in KRS (Korea Railway Standard) for system's robust design performance. Result: FEM analysis results are 14.9MPa & 14.7MPa of pin-joint, pivot and durability analysis result is above 1 million cycles. we calculated theoretically no failure test time 855,000 cycles and through the 1 million cycles durability rig test in KRS standard we confirmed product quality. Conclusion: This platform safety step system was designed very safe in terms of a mechanical strength & durability.

• Journal of the Korean Data and Information Science Society
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• 제15권4호
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• pp.921-934
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• 2004

We consider the problem of identifying and testing outliers in linear regression. First, we consider the scale-ratio tests for testing the null hypothesis of no outliers. A test based on the ratio of two residual scale estimates is proposed. We show the asymptotic distribution of test statistics and investigate the properties of the test. Next we consider the problem of identifying the outliers. A forward procedure based on the suggested test is proposed and shown to perform fairly well. The forward procedure is unaffected by masking and swamping effects because the test statistics used a robust scale estimate.

• Journal of the Korean Statistical Society
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• 제15권1호
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• pp.9-25
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• 1986

In this paper we propose a distribution-free rank test for ordered alternatives in a randomized block design and investigate the properties of the proposed test. The proposed test is an extension of the Page test to allow replications in each cell. Some asymptotic properties including ARE's are investigated. A small sample Monte Carlo study was performed to compare the powers of the test considered in this paper for small samples. The results show that our proposed test is robust and efficient in the case of equally-spaced treatment effects.

• Communications for Statistical Applications and Methods
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• 제2권2호
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• pp.13-19
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• 1995

This paper considers model robust accelerated life test plans for estimating the logmean or percentile of product lige which is exponentially distributed. A linear relationship between the log mean life and the stress is assumed as usual, while the true relationship is quadratic. Optimum plans are then obtained by minimizing asymptotic mean squared error of maximum likelihood estimator of the log mean life.

• Journal of the Korean Statistical Society
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• 제25권3호
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• pp.419-432
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• 1996

When interactions are not present in a three-way layout, the lim-iting null distribution of the F statistic for testing main effects when applied to the rank-score transformed data is the same as the limiting null distribution of the usual F statistic when applied to the normal data. The simulation results exhibit that the rank transform test is robust with respect to significance level and powerful for testing main effects in a three-way factorial experiment.

• 산업기술연구
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• 제9권
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• pp.109-117
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• 1989

In the finite element analysis of semiconductor devices analysis, the solution often be diverged due to the numerical instability of discretized equations. To overcome this problems, a noble finite element code which guarantees a successful convergence is developed. The factor of divergence in the current continuity equation of semiconductor governing equations is derived using stability test and an adaptive mesh refine scheme is introduced to eliminates the divergence properties. A test calculation of GaAs MESFET model reveals that the proposed scheme has a robust self-convergence property and is suitable for the semiconductor devices analysis.

• 한국통신학회논문지
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• 제40권12호
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• pp.2363-2371
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• 2015

본 논문에서는 FAST(Features from Accelerated Segment Test) 특징점 검출기와 SIFT(Scale Invariant Feature Transform) 특징점 서술자(descriptor)를 사용하여 시점 변화에 강인한 특징점 정합 기법을 제안한다. 기존의 FAST 기법은 영상의 에지 부분을 따라서 불필요하게 특징점을 많이 추출하게 되는데 이러한 단점을 주곡률(principal curvatures)을 적용하여 개선한다. 추출된 특징점을 SIFT 서술자를 통해 기술하고 시점이 다른 두 영상으부터 구해진 정합쌍에 RANSAC(RANdom SAmple Consensus) 기법을 통하여 호모그래피(homography)를 계산한다. 시점 변화에 강인한 특징점 정합을 위해서 기준 영상의 특징점들을 호모그래피 변환을 통해 변경된 좌표와 시점이 다른 영상의 특징점 좌표간의 유클리디언(Euclidean) 거리를 통해 정합쌍을 분류한다. 같은 물체나 장소에 대해 시점이 변화된 여러 영상에 대한 실험을 통해서 제안하는 정합 기법이 적은 계산량으로 기존의 특징점 정합 기법보다 우수한 성능을 보여주는 것을 확인하였다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 춘계학술대회
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• pp.529-532
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• 2012

본 논문은 연마용 로봇의 외부에 대한 강건 제어를 위한 방법으로 로봇의 강인제어기법을 테스트하기 위한 방법으로 수평형 도립진자를 이용하여 제안한 기법을 선형화된 모델을 기반으로 제어하고자 한다. 수평형 도립진자를 이용한 복잡한 동특성 분석과 비선형 시스템의 수학적 모델링을 통해 수식화하였고, 선형화된 상태공간방정식을 이용하는 현대제어인 슬라이드 모드 제어를 도입하여 시스템 제어를 해보았다. 또한, 동역학의 파라미터를 설계하며 또한 알 수 없는 외란과 파라미터 변동을 추정하는 외란 관측기를 사용하여 더욱 제어 시스템에 강인성을 실험결과로 분석하였다.

• 한국음향학회지
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• 제20권7호
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• pp.69-75
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• 2001

화자확인에서 화자내 변이, 잡음환경, 그리고 학습환경과 인식 환경의 불일치는 화자확인 시스템이 실용화될 수 없는 가장 큰 원인이다. 본 연구에서는, 실제 환경에 강인한 화자 확인 시스템의 구현에 초점을 맞추어 음성 전처리 과정인 잡음환경에 강인한 끝점추출 알고리즘, 잡음제거 및 마이크특성 보상기법, LPG(Linear Predictive Coefficient)켑스트럼 가중치에 의한 화자간 변별력 향상 기법을 제안한다. 실험 결과, LPC잔차신호(residue)를 이용한 끝점추출 알고리즘을 사용한 경우 약 17.65% 가량의 끝점 추출 에러율을 향상시켰으며, 제안한 잡음제거 및 마이크특성 보상기법을 사용한 경우 다른 마이크 환경에서 화자 오인식율이 약 36.93% 가량 개선되었다. 또한, 제안한 LPC켑스트럼 가중치에 의한 화자간 변별력 향상 기법은 평균 화자 오인식율을 약 6.515% 향상시켰다.