• 전기학회논문지
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• 제65권8호
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• pp.1418-1423
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• 2016

The purpose of this research is to investigate the effect of sampling frequency on the photoplethysmography (PPG) and to evaluate the performance of interpolation methods for under-sampled PPG. We generated down-sampled PPG using 10 kHz-sampled PPG then evaluated waveshape changes with correlation coefficient. Correlation coefficient was significantly decreased at 50 Hz or below sampling frequency. We interpolated the down-sampled PPG using four interpolation method-linear, nearest, cubic spline and piecewise cubic Hermitt interpolation polynomial - then evaluated interpolation performance. As a result, it was shown that PPG waveform that was sampled over 20 Hz could be reconstructed by interpolation. Among interpolation methods, cubic spline interpolation showed the highest performance. However, every interpolation method has no or less effect on 5 Hz sampled PPG.

• 대한수학회지
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• 제38권3호
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• pp.657-667
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• 2001

We propose a statistical interpolation approximate solution for a nonlinear stochastic integral equation of a stock price process. The proposed method has the order O(h$^2$) of local error under the weaker conditions of $\mu$ and $\sigma$ than those of Milstein' scheme.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.1151-1154
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• 1993

The purpose of the paper is to explain some heuristic, common sense suppositions of fuzzy control. It is shown that Fuzzy Control is a kind of quasilinear interpolation of prototypes. Control function can be sufficiently exact represented as piecewise-linear function. The best interpolation is connected with normalized intersected fuzzy sets.

• 치과방사선
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• 제29권1호
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• pp.65-85
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• 1999

Objectives: To determine the effect of interpolation functions when processing the digital periapical images. Material and Methods: The digital images were obtained by Digora and CDR system on the dry skull and human subject. 3 oral radiologists evaluated the 3 portions of each processed image using 7 interpolation methods, and ROC curves were obtained by trapezoidal methods. Results: The heighest Az value(0.96) was obtained with cubic spline method and the lowest Az value(0.03) was obtained with facet model method in Digora system. The heighest Az value (0.79) was obtained with gray segment expansion method and the lowest Az value(0.07) was obtained with facet model method in CDR system. There was significant difference of Az value in original image between Digora and CDR system at a=0.05 level. There were significant differences of Az values between Digora and CDR images with cubic spline method, facet model method, linear interpolation method and non-linear interpolation method at α=0.1 level.

• 제어로봇시스템학회논문지
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• 제11권9호
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• pp.755-760
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• 2005

This paper proposes an improved implementation algorithm for the continuous-time receding horizon control (RHC). The proposed algorithm has a feature that it has better control performance than the existing algorithm. Main idea of the proposed algorithm is that we can approximate the original RHC problem better by assuming the predicted input trajectory on the prediction horizon has a continuous form, which is constructed from linear interpolation of finite number of vectors. This, in turn, leads to improved control performance. We derive a predictor such that it takes linear interpolation into account and proposes the method by which we can express the cost exactly. Through simulation study fur an inverted pendulum, we illustrate that the proposed algorithm has the better control performance than the existing one.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 제13회 신호처리 합동 학술대회 논문집
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• pp.479-482
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• 2000

다중경로 채널의 시변 특성은 OFDM(orthogonal frequency division multiplexing) 신호의 직교성을 파괴시키며 이는 인접 채널간 간섭(ICI: interchannel interference)을 발생시켜 도플러 주파수에 비례하는 오류를 발생시킨다. 본 논문에서는 채널 시변의 원인을 주파수 옵셋과 도플러효과로 규정하고, 주파수 옵셋을 보정하기 위해 기존의 선형보간법(LI: linear interpolation method)대신 선형위상보간법(LPI: linear phase interpolation)과 도플러효과에 의한 ICI 를 제거하기 위해 기존의 주파수영역 등화기법보다 효과적인 시간영역 등화기법을 제안한다. 제안된 기법이 주파수 옵셋이 있는 시변 다중경로 페이딩 환경에서 OFDM 시스템에 적합함을 컴퓨터 모의실험을 통해 확인한다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1999년도 학술대회
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• pp.161-165
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• 1999

다중경로 채널의 시변 특성은 OFDM(orthogonal frequency division multiplexing) 신호의 직교성을 파괴시키며 이는 인접 채널간 간섭(ICI: inter channel interference)을 발생시켜 도플러 주파수에 비례하는 오류를 발생시킨다. 본 논문에서는 채널 시변의 원인을 주파수 옵셋과 도플러효과로 규정하고, 주파수 옵셋을 보정하기 위해 기존의 선형보간법(LI: linear interpolation method)대신 선형위상보간법(LPI: linear phase interpolation)과 도플러효과에 의한 ICI를 제거하기 위해 기존의 주파수영역 둥화기법보다 효과적인 시간영역 등화기법을 제안한다. 제안된 기법이 주파수 옵셋이 있는 시변다중경로 페이딩 환경에서 OFDM 시스템에 적합함을 컴퓨터 모의실험을 통해 확인한다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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• pp.562-567
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• 1998

This paper examined the relations among the multidimensional linear interpolation(MDI) and fuzzy reasoning , and neural networks, and showed that an showed that an MDI is a special form of Tsukamoto's fuzzy reasoning and regularization networks in the perspective of fuzzy reasoning and neural networks, respectively. For this purposes, we proposed a special Tsukamoto's membership (STM) systemand triangular basis function (TBF) networks, Also we verified the condition when our proposed TBF becomes a well-known radial basis function (RBF).

• 한국콘텐츠학회논문지
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• 제5권1호
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• pp.127-134
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• 2005

본 연구에서는 등고선 영상의 정점근방에서 발생하는 끊김을 연결하기 위하여 극좌표계 선형 보간을 제안한다. 성능을 평가하기 위해 몇 가지의 그래픽 영상에 기존 방법과 제안 방법을 적용한 실험에서, MAE가 평균 1.940화소인 선분을 생성할 수 있었다. 특히 실제의 등고선 영상에 대해서는 1.240화소의 MAE로 기존 방법보다 우수한 것으로 나타났다. 또한 인접 등고선과 닮은 꼴의 등고선을 생성함으로써 자연스러운 등고선을 재구성하였다.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2012년도 추계학술발표대회
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• pp.623-625
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• 2012

In this paper, we present a method to automatically generate a color pencil sketch image from a photo. First the image is converted into a sketch using a gradient estimation and then the color pencil sketch is produced by linear interpolation with original image and the sketched image. The experimental results show that the final image has a visual aspect of a color pencil sketch like image.