• 대기
• /
• 제14권3호
• /
• pp.19-28
• /
• 2004

In this study, two years Automatic Weather Station (AWS) data observed near the coast and islands are used to evaluate gust factors only when time averaged wind speed is higher than 5 ms. The gust factors are quite different in spatial and temporal domain according to analysis method. As the averaged time is increased, the gust factors are also increased. But the gust factors are decreased when wind speed is increased. It is because each wind speed is averaged one and a maximum wind is the greatest one for each time interval. The result from t-test is shown that all data are included within the 99% significance level. A sample standard deviation of ten minutes and one minute are 0.137~0.197, 0.067~0.142, respectively. Recently, the gust factor provided at the Korea Meteorological Administration (KMA) Homepage is calculated with one-hour averaged method. All though this method is hard to use directly for forecasting the strong wind over sea and coast, the result will be a great help to express Ocean Storm Flash in the Regional Meteorological Offices and the Meteorological Stations.

• 한국음향학회:학술대회논문집
• /
• 한국음향학회 1993년도 학술논문발표회 논문집 제12권 1호
• /
• pp.206-209
• /
• 1993

The main purpose of this paper is to verify the effectiveness of a high resolution direction finding method, so called the‘averaged MUSIC’. This method uses a new sample array covariance matrix that consists of diagonal components obtained by taking averages of the diagonal component values of the sample covariance matrix for the MUSIC. The paper shows that the proposed method performs higher resolved direction-of-arrival estimation and better resolution probability than the MUSIC in such cases as low signal-to-noise ratio, when the number of sensors used is finite, based on the statistical analysis.

• 전자공학회논문지B
• /
• 제31B권4호
• /
• pp.129-137
• /
• 1994

In this paper, a new texture feature extraction method for texture image classification is proposed. The proposed method is a modified texture spectrum method. It uses local weighting averaged texture unit, that is, the neighbor pixels are weithted and averaged in 4-direction and the calculated values are compared with center pixel to find texture units. The proposed method has only 81 texture units and these units are really good features for texture classification. The proposed method is applied to vegetable images and Blodatz album images and compared with several conventional methods for the feature extraction time and the recognition rate.

• Journal of Nutrition and Health
• /
• 제30권5호
• /
• pp.512-519
• /
• 1997

To investigate the energy, protein, lipid, and lactose intakes of breast-fed infants of lacto-ove-vegetarians, 25 infants(13 boys, 10 girls) were examined on the 0.5th, 1st, 2nd, and 3nd months of lactation. The amount of breast milk intake was determined by a test-weighing method, and the energy content of protein, lipid, and lactose was calculated using the Atwater factor. Thedaily energy intake for boys averaged 316, 436, 447, and 431kcal and that of girls averaged 284, 399, 401, and 390kcal during lactation, respectively. Average energy intake of boys from milk from 2nd week to the 3rd month postpartum was significantly higher than that of girls(p<0.05), because milk intake volume of boys was much higher than that of girls. The protein intake of boys on 2nd week-3rd month averaged 7.33g/day and that of girls averaged 6.29g/day. The lipid intake of 2nd week, months averaged 21.8g/day and that of girls averaged 20.1g/day. The lactose intake of boys averaged 45.48g/day, while that of girls averaged 41.09g/day. The mean intake of protein and lactose in boys was significantly higher than that of girls.

• 한국통신학회논문지
• /
• 제23권9A호
• /
• pp.2355-2364
• /
• 1998

In conventional fractal decoding procedure, the reconstructed image is obtained by a rpredefined number of iterations starting with an arbitrary initial image. Its convergence speed depends on the selection of the initial image. It should be solved to get high speed convergence. In this paper, we theoretically reveal that conventional method is approximately decomposed into the decoding of the DC and AC components. Based on this fact, we proposed a novel fast fractal decoding algorithm made up of two steps. The averaged-image considered as an optimal initial image is estimated in the first step. In the second step, the reconstructe dimag eis genrated from the output image obtained in the first step. From the simulations, it is shown that the output image of the first step approximately converges to the averaged-image with only 15% calculations for one iteration of conventional method. And the proposed method is faster than various decoding mehtods and evenly equal to conventioanl decoding with the averaged-image. In addition, the proposed method can be applied to the compressed data resulted from the various encoding methods because it does not impose any constraints in the encoding procedure to get high decoding speed.

• Nuclear Engineering and Technology
• /
• 제24권3호
• /
• pp.252-262
• /
• 1992

시간 및 공간 종속형 중성자 수송 방정식으로부터 비균질 원자로 노심해석의 효율적인 방법을 개발하였다. 이를 위해 계산 시간을 단축하고 각 집합체 크기의 소격격자(coarse mesh)에 대한 평균 중성자속을 정확히 예측할 수 있도록 노달방법(nodal method)을 도입하였고, 노드 별 평균 중성자속과 노드 각 경계면의 평균 중성자속 및 유속(flux and current)과의 관계식을 얻기 위하여 조정 인자( correction factor)로서 불연속인자(discontinuity factor)를 사용하였으며, 이 인자는 이전 시간대(previous time step)의 노드 평균 중성자속, 확산계수, 그리고 불연속인자 등에 따라 새로이 계산(updating)된다. 본 논문에서 개발된 방법을 시간에 따라 비교적 단순히 변하는 과도 노심(TWIGL)과 급격한 중성자 거동의 변화를 모사하는 과도 노심(LRA)에 적용한 결과 정확성 및 효율성이 입증되었 다.

• 대한음성학회지:말소리
• /
• 제64호
• /
• pp.155-169
• /
• 2007

Discrimination between speech and music is important in many multimedia applications. In our previous work, focusing on the spectral change characteristics of speech and music, we presented a method using the mean of minimum cepstral distances (MMCD), and it showed a very high discrimination performance. In this paper, to further improve the performance, we propose to employ time-averaged MFCC in computing the MMCD. Our experimental results show that the proposed method enhances the discrimination between speech and music. Moreover, the proposed method overcomes the weakness of the conventional MMCD method whose performance is relatively sensitive to the choice of the frame interval to compute the MMCD.

• Nuclear Engineering and Technology
• /
• 제21권3호
• /
• pp.193-204
• /
• 1989

본 논문에서는 정보 이론의 maximum entropy Principle을 이용하여 중성자속 분포를 재생하는 새로운 방법을 시도하였다. 어떤 대상에 대한 부분적인 정보가 있을 때, 이 정보의 한도 내에서 entropy를 최대화시키는 확률 분포는 가장 객관적인 것이 된다. Nodal method계산결과인 평균 중성자속과 current의 값을 prior information으로 삼고, 핵 연료 집합체의 경계에서의 중성자속 분포를 확률의 형태로 변환해서 확률로써 다룬다. Prior information의 한도 내에서 entropy를 최대화시키는 경계에서의 확률 분포를 구하면 핵연료 집합체의 경계에서의 중성자속 분포가 구해지는데, 이것을 경계조건으로 heterogeneous assembly calculation을 행하여 세부적인 중성자속 분포를 구한다. 이 새로운 방법을 몇 개의 benchmark problem assembly에 응용해 본 결과, 노심의 안쪽 부분에서는 이 방법이 form function method에 의한 것과 비슷한 정확도를 보였고 바깥 부분에서는 다소 큰 오차를 보였다. 본 논문에서는 surface-averaged neutron current를 prior in-formation에 포함시키지 못했는데, 이것을 포함시키면 결과가 훨씬 개선 될 것으로 보인다.

• 대한토목학회논문집
• /
• 제34권2호
• /
• pp.493-503
• /
• 2014

국내 유역에서 유효우량을 산정하기 위한 방법으로 주로 유역 평균 CN을 적용하는 NRCS-CN 방법이 사용되고 있다. 본 연구에서는 국내 유역에 적절한 유역 대표 유효우량 산정법을 개발하기 위하여, 토지이용종류별 CN을 면적가중평균한 유역 대표 CN을 이용하여 산정한 유효우량(유효우량 I)과 토지이용종류별 CN을 이용하여 소구역 유효우량을 산정한 후 면적가중평균한 유효우량(유효우량 II)을 산정한 후, 관측된 강우-유출 자료를 이용하여 산정한 직접유출량과의 비교분석을 수행하였다. 본 연구 결과, 유효우량 II가 유효우량 I 보다 전반적으로 크게 산정되었으며, 이는 유효우량 I이 가지는 관측 직접유출량과의 오차를 크게 줄여주는 것이다. 또한, 본 연구에서 수행한 오차분석은 유효우량 II가 유효우량 I 보다 관측 직접유출량에 대한 높은 정확성을 가지는 것을 보여주었다.

• 한국생산제조학회지
• /
• 제8권4호
• /
• pp.79-86
• /
• 1999

Electronic Speckle Pattern Interferometry(ESPI) is a powerful tool to measure the vibration mode shape and resonance frequency for modal analysis. As for ESPI this method is very suited for full-field measurement of objects in industrial areas because the interferograms are recorded with a video camera and evaluated in real-time with a computer. In this study We performed experiments at the same constraint conditions as disk brake of the practical vehicle as far as possible and obtained the resonance frequencies and vibration mode shapes by using time-averaged ESPI at once. Finally to assure the expetimental results by time-averaged ESPI we also compare those with results obtained by Laser Doppler Vibrometer and obtained good agreement.