• 제어로봇시스템학회논문지
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• 제7권12호
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• pp.1015-1023
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• 2001

error behaviour can be considered as a linear combination of low amplitude random noise and abrupt jumps. The reason of jump appearance can be explained by the semi-shading effects(buildings, trees), jamming, high dynamic of vehicle and so on. This study describes the stand-alone GPS error jump smoothing algorithm which is developed based on the scalar adaptive filter. The algorithm consists of the coarse jump smoothing and the fine jump smoothing. On the coarse smoothing step, GPS velocities or position differences are used as the measurement for the scalar adaptive filter. The purpose of adaptive filter is to smooth the jump errors. The coarse positions are detennined by the integration of smoothed velocities. On the fine smoothing step, the differences between GPS positions and the coarse positions are smoothed by another scalar adaptive filter. The reason of fine smoothing is based on the facts that smoothing accuracy depends on the variance ofusefuJ signa\. The coarse smoothing which deal with the difference of positions provides the rough error removing. So the coarse smoothed velocities can have much more low amplitude than the raw ones. The fine smoothing procedure provides high quality of filtering process. Simulation results show the efficiency of proposed scheme.

• 국제지역연구
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• 제15권3호
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• pp.191-213
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• 2011

본 연구는 소비위험분산 목적으로 실행된 소득위험분산이 실질적으로 소비위험분산에 기여할 수 있는지 여부를 실증분석을 통하여 검증한다. 국가 간 생산요소 이동에 따른 순요소소득의 발생은 국가 간 소득위험분산의 주요 수단 중 하나이다. 순요소소득 변화가 소비 변화에 미치는 영향과 GDP 변화가 소비 변화에 미치는 영향이 동일하다는 선행연구의 가정 하에서 국가 간 생산요소 이동을 통한 소득위험분산은 소비위험분산에 기여하는 것으로 여겨졌다. 1999년부터 2010년 기간 중 EU 12개 국가들의 사례를 통한 본 연구의 실증분석 결과 순요소소득에 대한 소비반응은 GDP에 대한 소비반응보다 낮으며, 더 나아가 순요소소득의 변화가 소비의 변화에 미치는 영향은 매우 낮은 것으로 나타났다. 따라서 순요소소득과 GDP 각각에 대한 소비반응이 동일하다는 기존 선행연구의 가정 하에서, 국가 간 생산요소 이동을 통한 소득위험분산의 소비위험분산에 대한 기여도는 과대평가되었음을 본 연구는 암시한다. 본 연구는 국가 간 생산요소 이동을 통한 소득위험분산이 실질적으로 소비위험분산에 기여하도록 하기 위해서는, 순요소소득이 소비에 유의하게 영향을 미칠 수 있어야함을 시사하며, 따라서 국외로부터의 순요소소득이 보다 직접적으로 소비로 귀결되기 위한 법제도 및 관련 시스템의 개선이 필요할 것이다.

• 대한지리학회지
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• 제49권3호
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• pp.339-356
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• 2014

DEM의 보급과 처리 기술의 발전으로 DEM으로부터 하천종단을 추출하는 것이 과거 어느 때보다 용이해졌다. 하지만 DEM에서 추출된 하천종단은 인위적인 평지 및 계단과 같은 문제점들도 포함하고 있기 때문에, 자연스런 하천종단을 얻어내기 위해서는 평활화 과정을 거쳐야 한다. 그러나 평활화 자체는 원본 하천종단의 변형을 필연적으로 동반하기 마련이다. 지금까지는 평활화로 인한 원자료의 변형에 대해 객관적이고 정량적인 평가가 없었다. 이에 본 연구는 주요 평활화 방법의 특성을 파악하고, 이들의 한계점을 극복하는 새로운 평활화 방법을 제안하며, 이의 유용성을 검증하였다. 본 연구는 보다 정밀한 평활화 방법을 제시할 뿐만 아니라 연구목적에 부합하는 평활화 방법을 선택하는데도 도움이 될 것이다.

• Journal of the Korean Data and Information Science Society
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• 제9권1호
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• pp.77-88
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• 1998

Smoothing spline estimators are modified to remove boundary bias effects using the technique proposed in Eubank and Speckman (1991). An O(n) algorithm is developed for the computation of the resulting estimator as well as associated generalized cross-validation criteria, etc. The asymptotic properties of the estimator are studied for the case of a linear smoothing spline and the upper bound for the average mean squared error of the estimator given in Eubank and Speckman (1991) is shown to be asymptotically sharp in this case.

• 한국통신학회논문지
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• 제22권1호
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• pp.185-192
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• 1997

We propose a method of paramete estimation using order-of-magnitude analysis for optimal boundary smoothing in Mean Field Annealing(MFA) technique in this paper. We previously proposed two boundary smoothing methods for consistent object representation in the previous paper, one is using a constratined regulaization(CR) method and the other is using a MFA method. The CR method causes unnecessary smoothing effects at corners. On the other hand, the MFA method method smooths our the noise without losing sharpness of corners. The MFA algorithm is influenced by several parameters such as standard deviation of the noise, the relativemagnitude of prior ter, initial temperature and final temperature. We propose a general parameter esimation method for optimal boundary smoothing using order-of-magnitude analysis to be used for consistent object representation in this paper. In addition, we prove the effectiveness of our parameter estimation and also show the temperature parameter sensitivities of the algorithm.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권2호
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• pp.78-89
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• 2016

Purpose: In this paper, we investigate whether the endeavors for Six Sigma quality management by a firm have positive effects on its financial performance and the length of Six Sigma implemented period affects its financial status. We find a relationship between Six Sigma implemented period and several financial performance index using a smoothing spline function. Methods: A smoothing spline function is used in order to analyze the relationship between efforts for quality management and financial performance. Specifically, the return on assets, return on equity, sales cost and business fee are investigated as dependent variables and the efforts for quality management as independent variable. Results: As a result of the analysis, the indication is that companies that put effects into the Six Sigma quality management have a positive result in its financial status. In detail, the efforts for Six Sigma quality management have positive effects on total asset turnover ratio and Six Sigma implemented period on net income to net sales ratio. Additionally, companies with longer (shorter) period of Six Sigma program have more (less) improvement in its financial status. Conclusion: It can be concluded that the company's efforts for quality management positively influence financial performance.

• 응용통계연구
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• 제25권3호
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• pp.457-464
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• 2012

Small area estimation is a statistical inference method to overcome the large variance due to the small sample size allocated in a small area. Recently some nonparametric estimators have been applied to small area estimation. In this study, we suggest a nonparametric mixed effect small area estimator using kernel smoothing and compare the small area estimators using labor statistics.

• Journal of Advanced Marine Engineering and Technology
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• 제38권2호
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• pp.182-187
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• 2014

We propose nonlinear GMM-based transformation functions in an attempt to deal with the over-smoothing effects of linear transformation for voice processing. The proposed methods adopt RBF networks as a local transformation function to overcome the drawbacks of global nonlinear transformation functions. In order to obtain high-quality modifications of speech signals, our voice conversion is implemented using the Harmonic plus Noise Model analysis/synthesis framework. Experimental results are reported on the English corpus, MOCHA-TIMIT.

• Journal of the Korean Data and Information Science Society
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• 제6권1호
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• pp.63-71
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• 1995

We have consider the study of local influence for smoothing parameter estimates in spline regression model with heteroscedasticity. Practically, generalized cross-validation does not work well in the presence of heteroscedasticity. Thus we have proposed the local influence measure for generalized cross-validation estimates when errors are heteroscedastic. And we have examined effects of diagnostic by above measures through Hyperinflation data.

• International Journal of Aeronautical and Space Sciences
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• 제18권1호
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• pp.118-128
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• 2017

In this study, we propose a real time inertial navigation system/global positioning system (INS/GPS) integrated smoothing algorithm based on an extended Kalman filter (EKF) and a position damping loop (PDL) for synthetic aperture radar (SAR). Integrated navigation algorithms usually induce discontinuities due to error correction update by the Kalman filter, which are as detrimental to the performance of SAR as the relative position error. The proposed smoothing algorithm suppresses these discontinuities and also reduces the relative position error in real time. An EKF estimates the navigation errors and sensor biases, and all the errors except for the position error are corrected directly and instantly. A PDL activated during SAR operation period imposes damping effects on the position error estimates, where the estimated position error is corrected smoothly and gradually, which contributes to the real time smoothing and small relative position errors. The residual errors are re-estimated by the EKF to maintain the estimation performance and the stability of the overall loop. The performance improvements were confirmed by Monte Carlo simulations. The simulation results showed that the discontinuities were reduced by 99.8% and the relative position error by 48% compared with a conventional EKF without a smoothing loop, thereby satisfying the basic performance requirements for SAR operation. The proposed algorithm may be applicable to low cost SAR systems which use a conventional INS/GPS without changing their hardware configurations.