• 대한수학회보
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• 제41권1호
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• pp.73-93
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• 2004

In [10], Chang and Skoug used a generalized Brownian motion process to define a generalized analytic Feynman integral and a generalized analytic Fourier-Feynman transform. In this paper we define the conditional generalized Fourier-Feynman transform and conditional generalized convolution product on function space. We then establish some relationships between the conditional generalized Fourier-Feynman transform and conditional generalized convolution product for functionals on function space that belonging to a Banach algebra.

• 대한수학회논문집
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• 제24권3호
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• pp.397-413
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• 2009

In this paper, for functionals of a generalized Brownian motion process, we show that the generalized Fourier-Feynman transform of the convolution product is a product of multiple transforms and that the conditional generalized Fourier-Feynman transform of the conditional convolution product is a product of multiple conditional transforms. This allows us to compute the (conditional) transform of the (conditional) convolution product without computing the (conditional) convolution product.

• 한국통신학회논문지
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• 제34권10B호
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• pp.1086-1092
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• 2009

Stereoscopic conversion has been an important and challenging issue for many 3-D video applications. Usually, there are two different stereoscopic conversion approaches, i.e., image motion-based conversion that uses motion information and object-based conversion that partitions an image into moving or static foreground object(s) and background and then converts the foreground in a stereoscopic object. As well, since the input sequence is MPEG-1/2 compressed video, motion data stored in compressed bitstream are often unreliable and thus the image motion-based conversion might fail. To solve this problem, we present the utilization of key-motion that has the better accuracy of estimated or extracted motion information. To deal with diverse motion types, a transform space produced from motion vectors and color differences is introduced. A key-motion is determined from the transform space and its associated stereoscopic image is generated. Experimental results validate effectiveness and robustness of the proposed method.

• Earthquakes and Structures
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• 제16권2호
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• pp.165-175
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• 2019

Incremental dynamic analysis (IDA), as an accurate method to evaluate the parameters of structural performance levels, requires many non-linear time history analyses, using a set of ground motion records which are scaled to different intensity levels. Therefore, this method is very computationally demanding. In this study, a new method is presented to estimate the summarized (16%, 50%, and 84% fractiles) IDA curves of a first-mode dominated structure using discrete wavelet transform and bees optimization algorithm. This method reduces the number of required ground motion records for the prediction of the summarized IDA curves. At first, a subset of first list ground motion records is decomposed by means of discrete wavelet transform which have a low dispersion estimating the summarized IDA curves of equivalent SDOF system of the main structure. Then, the bees algorithm optimizes a series of factors for each level of detail coefficients in discrete wavelet transform. The applied factors change the frequency content of original ground motion records which the generated ground motions records can be utilized to reliably estimate the summarized IDA curves of the main structure. At the end, to evaluate the efficiency of the proposed method, the seismic behavior of a typical 3-story special steel moment frame, subjected to a set of twenty ground motion records is compared with this method.

• 한국전자파학회논문지
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• 제26권7호
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• pp.656-665
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• 2015

본 논문에서는 시간-주파수 변환에 요동보상을 적용한 UWB 레이다 Bistatic ISAR (Bistatic Inverse Synthetic Aperture Radar: B-ISAR) 이미징에 적용하여 레이다 이미징의 선명도와 품질을 개선하였다. UWB 레이다를 사용하여 제안하는 시간-주파수 알고리즘을 검증하였으며, 이를 위하여 B-ISAR 알고리즘 절차, 시간-주파수 변환과 요동보상 개선 등 필요한 이론적 근거를 제시하였다. B-ISAR 이미징 알고리즘으로 이미지를 생성하였으며, UWB 바이스테틱 ISAR 이미징 생성시 요동보상을 적용한 시간-주파수 변환 기법인 STFT(Short-Time Fourier Transform), GWT(Gabor Wavelet Transform), WVD(Wigner-Ville distribution) 방식을 차례대로 구현하였다. 그리고 STFT, GWT와 WVD 알고리즘을 이용하여 B-ISAR 이미징 알고리즘의 성능을 비교하였으며, 그 결과 WVD가 다른 방식들에 비하여 영상이 선명하고, 퍼짐 현상이 줄어듦을 알 수 있었다.

• 방송공학회논문지
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• 제15권3호
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• pp.355-361
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• 2010

영상 압축은 멀티미디어 전송에 있어 핵심적인 기술이다. 동영상 압축 기술 중 움직임 예측부는 전체 동영상 압축 부호화에서 가장 복잡한 부분으로, 멀티미디어의 실시간 전송을 위하여 고속 알고리듬이 필요한 부분이다. 본 논문은 기존의 고속 움직임 예측 알고리듬의 하나인 이진 블록 정합 움직임 예측 알고리듬을 개선하여 더욱 정확한 움직임 벡터를 찾는 방법을 제안한다. 제안하는 알고리듬은 웨이블릿 변환 후 고주파 대역의 정보값을 이용해 움직임 벡터를 찾음으로써 기존의 알고리듬을 개선한다. 제안하는 알고리듬은 기존의 알고리듬의 화질을 향상시킨다.

• 방송공학회논문지
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• 제18권5호
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• pp.730-737
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• 2013

본 논문은 정합 오차 기준을 확장한 제한된 1비트 변환 (Constrained One-Bit Transform : C1BT) 기반의 움직임 예측 알고리즘을 제안하였다. 제한된 1비트 변환 기반의 움직임 예측 알고리즘에서는 정합 오차 기준으로 기존의 움직임 예측 방법인 전역 탐색 알고리즘 (Full Search Algorithm: FSA)에서 사용되는 SAD (Sum of Absolute Differences) 대신 NNMP (Number of Non-Matching Points)를 사용하여 하드웨어 구현을 용이하게 하고 연산량을 크게 줄였으나 움직임 예측의 정확도를 감소시켰다. 이 점을 개선하고자 이 논문에서는 제한된 1비트 변환의 정합 오차 기준을 확장하여 움직임 예측의 정확도를 높이는 알고리즘을 제안하였고 이는 기존의 알고리즘과 비교한 결과 PSNR (Peak Signal to Nosie Ratio) 측면에서 더 우수한 성능을 보였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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• pp.236-239
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• 1988

Prediction errors generated by motion compensated coding are coded with transform coding techniques as DCT. The performance of transform coding techniques are lowered mainly due to the source characteristics with a great deal of zero populations and plus-minus sign changes, i.e., low correlation. In this paper a transform coding scheme which adopts a decomposition of prediciton errors into two sources is proposed and compared its performance with conventional scheme.

• 충청수학회지
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• 제21권2호
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• pp.231-246
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• 2008

In this paper, we use a generalized Brownian motion process to define a generalized analytic Feynman integral. We then establish several integration formulas for generalized analytic Feynman integrals generalized analytic Fourier-Feynman transforms and generalized integral transforms of functionals in the class of functionals ${\mathbb{E}}_0$. Finally, we use these integration formulas to obtain several generalized Feynman integrals involving the generalized analytic Fourier-Feynman transform and the generalized integral transform of functionals in ${\mathbb{E}}_0$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.38-40
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• 2007

In this paper, we propose a novel architecture, which is based on DCT (Discrete Cosine Transform), for ME (Motion Estimation) and MC (Motion Compensation). The traditional algorithms of ME and MC based on DCT did not suffer the advantage of the coarseness of the 2-dimensional DCT (2-D DCT) coefficients to reduce the operational time. Therefore, we derive a recursion equation for transform-domain ME and MC and design the structure by using highly regular, parallel, and pipeline processing elements. The main difference with others is removing the IDCT block by using to transform domain. Therefore, the performance of our algorithm is more efficient in practical image processing such as DVR (Digital Video Recorder) system. We present the simulation result which is compare with the spatial domain methods. it shows reducing the calculation cost. compression ratio. and peak signal to noise ratio (PSNR).