• The KIPS Transactions:PartA
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• v.13A no.5 s.102
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• pp.465-472
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• 2006

Recently, many suggestions have been made in image segmentation methods for extracting human organs or disease affected area from huge amounts of medical image datasets. However, images from some areas, such as brain, which have multiple structures with ambiruous structural borders, have limitations in their structural segmentation. To address this problem, clustering technique which classifies voxels into finite number of clusters is often employed. This, however, has its drawback, the influence from noise, which is caused from voxel by voxel operations. Therefore, applying image enhancing method to minimize the influence from noise and to make clearer image borders would allow more robust structural segmentation. This research proposes an efficient structural segmentation method by filtering based clustering to extract detail structures such as white matter, gray matter and cerebrospinal fluid from brain MR. First, coherence enhancing diffusion filtering is adopted to make clearer borders between structures and to reduce the noises in them. To the enhanced images from this process, fuzzy c-means clustering method was applied, conducting structural segmentation by assigning corresponding cluster index to the structure containing each voxel. The suggested structural segmentation method, in comparison with existing ones with clustering using Gaussian or general anisotropic diffusion filtering, showed enhanced accuracy which was determined by how much it agreed with the manual segmentation results. Moreover, by suggesting fine segmentation method on the border area with reproducible results and minimized manual task, it provides efficient diagnostic support for morphological abnormalities in brain.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.5B
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• pp.871-878
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• 2000

A divided matched filter-reference filter(MF-RF) technique for LEO satellite packet transmission is proposed to increase the packet throughput in the presence of severe Doppler shift and fading. To overcome the severe Doppler shift, the divided matched filter is adopted where the integration region of matched filter is divided and ouputs of divided matched filer are added to decide the correct pseudo-noise (PN) phase. To maintain the constant false alarm rate in time varying interference and fading channel, the adaptive threshold for acquisition is obtained from the reference filter. As a performance measure, average acquisition time and packet throughput are used, and the effets of the parameters, i.e., Doppler shift, chip energy to noise ratio, user velocity, standard deviation of shadowing, and preamble length are shown.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.65-70
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• 1999

음소 단위로 레이블링된 데이터베이스는 음성연구에 있어 매우 중요하다. 그러나 수작업에 의한 음소분할 및 레이블링 작업은 많은 시간과 노력이 필요하기 때문에 자동 음소분할 및 레이블링 시스템에 대한 많은 연구가 진행되고 있다. 저자들은 자동레이블링 시스템에서 레이블링 분할의 단위로monophone과 triphone의 장점을 포함하는 문맥 종속 반음소 단위 모델을 이용한 자동 음소분할 및 레이블링 시스템을 제안한바 있다[1]. 본 논문에서는 문맥종속 반음소 단위 자동음소분할 및 레이블링 시스템의 성능을 개선하기 위하여, 반음소의 단위를 개선하였다. 기존에 제안된 반음소 단위는 음소의 중점을 기준으로 left/right의 반음소 단위로 양분하였다. 본 논문에서는 음소의 길이가 120ms 이상일 경우 음소의 천이구간의 특성을 잘 나타낼 수 있도록, 음소의 앞뒤구간 각각 60ms를 전반음소와 후반음소로 나누고, 나머지 안정구간을 별도의 모델로 구성하였다. 본 논문에서 제안한 반음소 단위의 성능을 평가하기 위하여 PBW 452단어를 발성한 남자 30명분의 데이터를 이용하여 레이블링 시스템을 훈련하고, 훈련에 사용하지 않은 남자 4명분의 데이터를 이용하여 테스트 하였다. 실험결과, 기존의 반음소 단위에 비하여 10ms에서 $69.09\%$로 $1.65\%$, 20ms에서 $85.32\%$로 $1.02\%$의 성능향상을 가져왔다.

• Korean Journal of Poultry Science
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• v.17 no.1
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• pp.53-58
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• 1990

Tests to evaluate the efficacy of disinfectant "Lysococ" against the oocfsts of Eimeria tenella were tested. In the sporulation test the sporulation of unsporulated oocysts of E. tenella was nearly suppressed by contact with "Lysococ" in 4% concentration after 30 minutes. In the suspension test with sporulated oocysts, "Lysococ" 4% disinfected sporulated oocysts of 5. tenella completely after a contact tune on 10 minutes. When using the oocyst-carrier test, the 4% solution was able to disinfect sporulated oocysts after a 90 minutes contact time.ter a 90 minutes contact time.

• Journal of Internet Computing and Services
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• v.14 no.6
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• pp.41-47
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• 2013

GP-GPUs are general purposed GPUs for numerical computation based on multiple threads which are originally for graphic processing. GP-GPUs provide cache memory in a form of shared memory which user programs can access directly, unlikely typical cache memory. In this research, we implemented the parallel block LU decomposition program to utilize cache memory in GP-GPUs. The parallel blocked LU decomposition program designed with Nvidia CUDA C run 7~8 times faster than nun-blocked LU decomposition program in the same GP-GPU computation environment.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.120.1-120.1
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• 2011

현대 천문학의 주요한 이슈 중 하나인 외계행성은 570개 이상 발견되었는데, 이들 모두 우리 은하내 외계행성들이다. 우리는 KMTNet 광시야 관측시스템을 이용하여 마젤란 은하내 외계행성을 Transit 방법으로 탐색 관측하여 외부은하 최초의 외계행성을 발견하고자 한다. 이제까지 알려진 Transit 행성들의 별표면 통과시간(transit duration)은 대부분 100-300분 사이에 분포하기 때문에, 이 현상의 검출은 최대 10분의 시간분해능을 필요로 한다. 한편, KMTNet 망원경은 마젤란 은하내 21등급의 별을 I 필터에서 10분의 노출로 1%의 측정정밀도를 얻을 수 있고, 8-10미터급 대형망원경을 이용하면 태양질량의 21등급 별을 공전하는 목성형 행성들의 분광후속 관측이 가능하다. 우리는 KMTNet으로 마젤란 은하내 19-21등급에 있는 F-G형 주계열성들과 청색수평가지별들(blue horizontal branch star)을 I 필터(관측 시작, 중간, 끝 시간에는 V 필터도 사용)에서 10분의 노출로 시계열 측광 관측하면, 다수의 Transit 외계행성을 발견할 수 있을 것으로 기대한다. 이와 더불어, 수년의 장시간 관측자료로부터 RR Lyr, ${\delta}$ Sct 및 식변광성의 극대/극심시각을 정밀하게 측정하여 Timing 방법으로 항성계 주위를 공전하는 장주기 외계행성을 발견할 수 있을 뿐만 아니라, 중력렌즈(self-lensing) 현상을 보이는 외계행성도 검출가능하다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.2
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• pp.310-317
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• 1996

현재 유통기간이 $10^{\circ}C$ 이하에서 1개월로 규정되어 있는 칠면조육을 함유한 훈제 햄의 유통기간을 연장하기 위하여 가공공정 중, 훈연실 내에서의 훈연 및 1차 열처리 공정을 검토하였으며, 통조림으로 가공하였을 때의 적정 $F_{0}$-값을 설정하였다. 훈연실에서의 공정 중, 훈연 조건을 $75^{\circ}C,$ 30분에서 80분으로 연장하였을 때 미생물의 수를 훈연 전의 것 보다 거의 $1/10^{3}$로 감소시킬수 있었다. 그러나 훈연 시간을 연장하면, 제품의 표면 색깔이 지나치게 짙어져서 상품성이 현저하게 떨어지는 현상을 초래하였다. 훈연에 이어지는 1차 열처리 공정에서는 $85^{\circ}C,$ 65분의 조건을 $95^{\circ}C,$ 185분까지 변화시켜도 미생물의 수를 감소시킬 수는 없었다. 이들 제품을 $10^{\circ}C에$ 저장하였을 때는 2개월 후에도 품질에 큰 변화가 없었으나, $37^{\circ}C에$ 저장하였을 때에는 1개월 이전에 완전히 부패하였다. 통조림으로 가공하여 $105^{\circ}C,$ $110^{\circ}C$ 및 $105^{\circ}C에서$ 열처리하였을 때, $F_{0}$-값8분 이상에서는 미생물이 전혀 검출되지 않았다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.1 no.1
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• pp.10-16
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• 2002

In this paper, a novel algorithm for segmentation of moving multiple vehicles in video sequences using logic operations is proposed. For the case of multiple vehicles in a scene, the proposed algorithm begins with a robust double-edge image derived from the difference between two successive frames using exclusive OR operation. After extracting only the edges of moving multiple vehicles using Laplacian filter, AND operation and dilation operation, the image is segmented into moving multiple vehicle image. The features of moving vehicles can be directly extracted from the segmented images. The proposed algorithm has no the two preprocessing steps, so it can reduce noises which are norm at in preprocessing of the original images. The algorithm is more simplified using logic operations. The proposed algorithm is evaluated on an outdoor video sequence with moving multiple vehicles in 90,000 frames of 30fps by a low-end video camera and produces promising results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.8B
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• pp.1391-1399
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• 2000

In this paper, we discussed the region-based image retrieval method using image segmentation. We proposed a segmentation method which can reduce the effect of a irregular light sources. The image segmentation method uses a region-merging, and candidate regions which are merged were selected by the energy values of high frequency bands in discrete wavelet transform. The content-based image retrieval is executed by using the segmented region information, and the images are retrieved by a color, texture, shape feature vector. The similarity measure between regions is processed by the Euclidean distance of the feature vectors. The simulation results shows that the proposed method is reasonable.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.4
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• pp.729-736
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• 2019

In this paper, we propose a method to improve the background sound separation performance by adding a Wiener filter to the end of the non - negative matrix factorization method. In the case of a mixed voice signal with background sound, a part that has not yet been completely separated may remain in the signal that separated first by the non-negative matrix factorization method. In this case, it can be reduced in proportion to the size of the residual signal due to the Wiener filter, so that the background sound separation or reduction effect can be expected. Experimental results show that the addition of the Wiener filter is more effective than the case of applying the non-negative matrix factorization method.