• 한국인쇄학회:학술대회논문집
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• 한국인쇄학회 1998년도 추계 논문 발표회 논문집
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• pp.31-35
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• 1998

Spectral reflrectance of the object should be measured to predict the color of object under various illuminants. The spectral reflectance can be represented in a multidemensional space. Generally we can obtain only three-channel data from input device such as CCD camera, color scanner etc. The estimation from three dimensional to multidimension can be achieved using principal components of spectral reflectance. In this paper, A method to predict the spectral reflectance of skin color taken by 3-channel input device is discribed. To confirm this method, we simulate color represent under various illuminants about yellow, white and colored women face.

• 융합신호처리학회 학술대회논문집
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• 한국신호처리시스템학회 2000년도 추계종합학술대회논문집
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• pp.49-52
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• 2000

The Estimation method for spectral reflectance of the object using five-band and nine-band have been developed. The five-band acquisition are required of five or three times same work for color image acquisition process. To solve the above problems, we proposed a new method that can be reconstructed spectral reflectance of object. The proposed method was to classify same hues corresponding a color stimulus, by using hue angle and chroma vector of a color stimulus. The reconstruction of spectral reflectance was examined by computer simulation, and evaluated by MSE(Mean Square Error) and color difference between the original and reconstructed spectral reflectance.

• 대한원격탐사학회지
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• 제36권1호
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• pp.55-65
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• 2020

Image classification needs the spectral similarity comparison between spectral features of each pixel and the representative spectral features of each class. The spectral similarity is obtained by computing the spectral feature vector distance between the pixel and the class. Each spectral feature contributes differently in the image classification depending on the class separability of the spectral feature, which is computed using a suitable vector distance measure such as the Bhattacharyya distance. We propose a method to determine the weight value of each spectral feature in the computation of feature vector distance for the similarity measurement. The weight value is determined by the ratio between each feature separability value to the total separability values of all the spectral features. We created ten spectral features consisting of seven bands of Landsat-8 OLI image and three indices, NDVI, NDWI and NDBI. For three experimental test sites, we obtained the overall accuracies between 95.0% and 97.5% and the kappa coefficients between 90.43% and 94.47%.

• 대한기계학회논문집A
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• 제20권6호
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• pp.1773-1783
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• 1996

Finite element method(FEM) is one of the most popularly used method analyzing the dynamic behaviors of structures. But unless number of finite elements is large enough, the results from FEM some what different from exact analytical solutions, especially at high frequency range. On the other hand, as the spectral analysis method(SAM) deals directly with the governing equations of a structure, the results from this melthod cannot but be exact regardless of any frequency range. However, the SAM can be applied only to the case where a structure is subjected to the concentrated loads, despite a structure could be unddergone distributed loads more generally. In this paper, therefore, new spectral analysis algorithm is introduced through the spectral element method(SEM), so that it can be applied to anlystructures whether they are subjected to the concentrated loads or to the distributed loads. The results from this new SEM are compared with both the results from FEM and the exact analytical solutions. As expected, the results from new SEM algorithm are found to be almost identical to the exact analytical solutions while those from FEM are not agreed well with the exact analytical solutions as the mode number increases.

• 한국정보통신학회논문지
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• 제13권10호
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• pp.2211-2217
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• 2009

본 논문에서는 잔향이 존재하는 환경에서 단일 마이크로폰을 사용한 음성 개선 방법을 제시한다. 스펙트럼 차감법(Spectral Subtraction)은 스펙트럼 상에서 잔향성분 및 잡음을 제거 할 수 있는 효과적인 방법이다. 스펙트럼 차감법은 음성과 비음성 구간의 정확한 구분을 필요로 하며 성능을 향상시키기 위해 본 논문에서는 엔트로피(Entropy) 기반의 음성 구간 검출법을 적용하였다. 제시된 방법을 기존의 에너지 검출 기반의 음성 검출법을 적용한 스펙트럼 차감법과 비교하여 성능 평가를 수행하였다. SNR 및 잔향시간에 따른 잔향 제거비율을 평가지표로 사용하였으며, 시뮬레이션 결과 기존의 스펙트럼 차감법과 비교하여 제시된 방법이 우수한 성능을 보였다.

• 한국대기환경학회지
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• 제9권3호
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• pp.242-246
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• 1993

Theoretically, spectral method has the highest accuracy among present numerical methods, but it is generally difficult to apply to complex terrains because of complex boundary conditions. Recently, spectral-element method, basically divide the domain into a set of rectangular subdomain and solve the equation at each subdomain, has been introduced. However, boundary conditions become more complex and requires more computing time, thus spectral-element method is not powerful for all complex terrain problems. In this paper, potential flow theory was intorduced to solve the air flows and diffusion phenomenon in the presence of terrain obstacles. Using the velocity potential-stream line orthogonal coordinate space, the diffusion problems of hilly terrain by pseudospectral method were solved and compared those with no terrain real scale solutions.

• 대한기계학회논문집A
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• 제29권4호
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• pp.578-583
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• 2005

This paper introduces a fast Fourier transform (FFT)-based spectral dynamic analysis method for the transient responses as well as the steady-state responses of the linear discrete systems subject to non-zero initial conditions. The forced vibration of a viscously damped three-DOF system is considered as the illustrative numerical example. The proposed spectral analysis method is evaluated by comparing its results with the exact analytical solutions and the numerical solutions obtained by the Runge-Kutta method.

• 한국인쇄학회지
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• 제16권3호
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• pp.97-108
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• 1998

Spectral reflectance of the object should be measured to predict the color of object under various illuminants. The spectral reflectance can be represented in a multi-dimension space. Generally the information of inputed image by digital camera and color scanner is represented with 3-dimension color signals such as RGB. In other to predict the color of inputed image under any illuminant, we should be estimated spectral reflectance of the object. In this paper, we described the method to predict spectral reflectance by einenvector using the skin color of printed image, confirmed availability and propriety through experiment. we estimated spectral reflectance of skin color taken by RGB color signals and than reproduced skin color according to various illuminants on CRT.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.33.5-33
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• 2001

We consider here the problem of spectral estimation of multidimensional wide sense stationary (WSS) random process. A method, employing a special difference equation of correlation function, is proposed to solve the problem of multidimensional spectral estimation. In this approach, the special difference equation of correlation function is derived by modal decomposition method. Maximum likelihood estimator and Kalman filter are used to estimate the model parameters of the difference equation and the decomposed spectral residues. An algorithm is presented to estimate the multidimensional spectral density. According to the result of the simulation, these methods are feasible to estimate the spectral density of WSS process, which is realized by finite dimensional multivariable lineal system driven by white noise.

• 한국소음진동공학회논문집
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• 제16권4호
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• pp.387-393
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• 2006

이 논문에서는 내부에 비정상 유동이 흐르는 균일한 직선 파이프에 대한 스펙트럴요소모델을 개발하였다. 개발된 스펙트럴요소모델에 대한 스펙트럴요소행렬은 주파수 영역에서 구한 파이프 역학 방정식의 엄밀해를 이용하여 유도되었다. 이 스펙트럴요소모델의 정확성을 평가하고 한 예제 파이프 계의 진동특성과 파이프 내부 유동특성을 고찰하기 위하여 스펙트럴 동역학 해석을 수행하였다.