• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2003년도 춘계학술대회논문집
• /
• pp.331-334
• /
• 2003

In the finite element simulation of hot forging processes using hexahedron, remeshing of a flash is very difficult. The mesh compression method is a remeshing technique to construct an effective hexahedral mesh. However, because mesh is distorted during the compression procedure or the mesh compression method, mesh smoothing is necessary to improve the mesh Qualify. in this study, several geometric mesh smoothing techniques and a matrix norm optimization technique are applied and compared which is more adaptive to the mesh compression method.

• 대한산업공학회지
• /
• 제16권2호
• /
• pp.129-134
• /
• 1990

Exponential smoothing methods have enjoyed a long history of successful applications and have been used in forecasting for many years. However, it has been long known that one of the deficiencies of the method is an inability to respond quickly to interventions to interruptions, or to large changes in level of the underlying process. An exponential smoothing method adaptive to repeated random level changes is proposed using a change-detection statistic derived from a simple dynamic linear model. The results are compared with Trigg and Leach's and the exponential smoothing methods.

• Journal of the Korean Data and Information Science Society
• /
• 제18권4호
• /
• pp.945-953
• /
• 2007

In this paper, we propose a smoothing and thus noise-reducing method of data sequences for stock price prediction with hidden Markov models, HMMs. The suggested method just uses simple moving average. A proper average size is obtained from forecasting experiments with stock prices of bank sector of Korean Exchange. Forecasting method with HMM and moving average smoothing is compared with a conventional method.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2001년도 ICCAS
• /
• pp.56.3-56
• /
• 2001

This study describes the jump error smoothing scheme with fuzzy logic based on the scalar adaptive filter. The scalar adaptive filter is an useful algorithm for smoothing abrupt jump errors. However, the performances of scalar adaptive algorithm depend on the variance of real signal. So to design an effective algorithm, many informations of real and jump signal are required. In this paper, the fuzzy rules are designed by the analysis of scalar adaptive filter, and then the improved and simplified scheme is developed for smoothing the jump error. Simulations to INS/GPS integrated system show that the proposed method is effective.

• Journal of applied mathematics & informatics
• /
• 제8권3호
• /
• pp.731-742
• /
• 2001

A Gaussian smoothing algorithm obtained from a cascade of convolutions with a seven-point kernel is described. We prove that the change of local sums after applying our algorithm to sinusoidal signals is reduced to about two thirds of the change by the binomial coefficients. Hence, our seven point kernel is better than the binomial coefficients when trend curves are needed to be generated. We also prove that if our Gaussian convolution is applied to sinusoidal functions, the amplitude of higher frequencies reduces faster than the lower frequencies and hence that it is a low pass filter.

• Journal of the Korean Statistical Society
• /
• 제30권4호
• /
• pp.645-660
• /
• 2001

In this paper we propose a goodness-of-fit test statistic for testing the (null) parametric model versus the (alternative) nonparametric model. Most of existing nonparametric test statistics are based on the residuals which are obtained by regressing the data to a parametric model. Our test is based on the bootstrap estimator of the probability that the smoothing parameter estimator is infinite when fitting residuals to cubic smoothing spline. Power performance of this test is investigated and is compared with many other tests. Illustrative examples based on real data sets are given.

• Journal of the Korean Statistical Society
• /
• 제24권2호
• /
• pp.495-506
• /
• 1995

We present formula for detecting influential observations on the smoothing parameter in smoothing spline. Further, we express them as functions of basic building blocks such as residuals and leverage, and compare it with the local influence approach by Thomas (1991). An example based on a real data set is given.

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

• 한국음향학회지
• /
• 제21권3호
• /
• pp.285-292
• /
• 2002

문자-음성 합성기 (Text-To-Speech, TTS)에서 해결되어야 할 문제점 중의 하나는 음소의 연결 부위에서 발생하는 불연속성이다. 이러한 문제점을 해결하기 위한 방안으로 본 논문에서는 저역 여파기를 이용한 스무딩 기법을 적용하였다. 제안된 스무딩 기법은 스무딩의 정도를 제어하는 필터 계수를 현재 합성하고자 하는 문맥에 따라 결정하여, 경계에서의 불연속성을 효과적으로 제거하고 스무딩으로 인하여 발생할 수 있는 음성의 왜곡을 억제하였다. 스무딩 정도는 현재 합성된 음성의 불연속 정도와 주어진 문맥으로부터 예측된 불연속 정도를 통해 결정하였으며, 문맥으로부터 불연속 정도의 예측은 음소 정보를 입력, 불연속 값을 출력으로 하는 CART(Classification And Regression Tree)를 통해 이루어진다. 제안된 기법의 성능 평가를 위해 코퍼스 기반 연결(corpus-based concatenative) 문자-음성 합성기를 기본 시스템으로 사용하였으며, 청취 테스트에서 60%이상 의 청취자가 제안된 스무딩 기법을 통해 합성된 음성이 스무딩 기법이 사용되지 않은 경우와 비교하여 명료성과 자연성 면에서 우수하다고 판단하였다.

• 대한자기공명의과학회:학술대회논문집
• /
• 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
• /
• pp.75-75
• /
• 2003

목적： MR 영상에 나타나는 bias field, 즉 영상의 특정 부분이 주위보다 어둡거나 밝게 나타나는 현상을 보다 균일하게 보정시키는 방법으로 제시된 N3 방법에서 Gaussian kernel을 사용한 smoothing 방법 대신에 Wavelet(Daubechies, D4)함수를 smoothing기법으로 사용했을 때 어느 정도 균일함에 향상이 일어나는지를 알아보는 것이다.