• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09b
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• pp.181-184
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• 2003

본 논문은 생체측정학(Biometrics)중 홍채의 패턴을 이용하는 것으로, 사람의 홍채는 태어날 때 한번 정해지면 평생 변화하지 않으며, 개개인별로 모양이 모두 다른 것으로 알려져 있다. 이에, 본 논문에서는 홍채영상 취득시 조명에 의한 동공의 크기 변화에 민감하지 않은 2차원의 홍채패턴을 취득하고, 2D Gabor 필터와 48개의 분할된 섹터로부터 특징값을 추출한다. 또한, 인식과정에서는 correlation 계수를 이용하여 서로 다른 홍채의 특징값에 대해 유사도를 측정하고 가장 큰 값을 갖는 사람을 찾게 되는데, 이때, 3개의 필터를 거쳐 얻어진 영상에 대해 최고의 값을 인식 대상자로 인정하므로 오인식 될 확률을 최소화 할 수 있다. 제안한 알고리듬의 유용성을 확인하기 위해 남성과 여성 대상자 10명의 왼쪽 눈에 대해 5회 촬영하여 데이터베이스 구축 후, 실험한 결과 90%이상의 높은 인식률을 얻음으로 제안한 알고리듬의 유용성을 확인할 수 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.2
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• pp.270-278
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• 1993

This paper is presented the phonetic segmentation alg9rithm of the Korean speech signals which is finded the exact pitch using the super resoluton pitch determination and is compared corss-correlation to threshold each pitch period. The features of the proposed algorithm are infinite resolution and high reliability, and also can separate transient or silent segment. The algorithm is instrumental to speech processing applications which require vector quantization and speech recognition. The presented algorithm is implemented by 386-MATLAB on PC 386/DX and is verified the exact pitch period and the phonetic segmentation of speech signals.

• Journal of KIISE:Software and Applications
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• v.28 no.2
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• pp.132-140
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• 2001

야외에서 인지되는 자연 경치는 다양한 개체, 빛의 산란, 또는 변화를 주는 많은 요소들 때문에 컴퓨터 영상처리에서 인식하기가 쉽지 않다. 본 논문에서는 다층 인지 신경망을 이용하여 도로가 포함된 야외영상에 나타나는 개체들을 인식하는 방법을 연구하였다. 자연 영상을 영역화한 후, 각각의 영역들에 대하여 색상과 기하학적인 특성에 근거하여 특성벡터를 추출하고 이를 신경망에 입력하여 각 영역을 구분하는 2단계의 알고리듬을 제안한다. 먼저 야외 영상들을 개선된 영역 확장법과 병합과정에 의하여 개체별로 영역화하였다. 영역화된 연상은 자연 영상과 함께 영상 데이타베이스에 저장되고, 이 자료들을 이용하여 각 영역의 특성벡터를 계산하였다. 이 특성 벡터를 구성된 신경망의 입력층에 전달하면, 각 영역은 27개의 개체 중의 하나로 출력층에서 인식된다. 제안된 방법은 학습에 사용된 데이타, 학스베 사용되지 않은 새로운 데이타, 그리고 모두 합하여 놓은 데이타의 세가지 데이타 군에서 무작위로 선별하여 인식률을 측정하였다. 학습된 데이타에서는 99.4%까지의 인식률을 보여주었고, 학습되지 않은 데이타에 대해서도 최고 89.1%까지의 인식률을 나타내었다. 제안된 방법은 평균적으로 88.1%~97.9%의 인식률을 보여주어 자연 경치의 인식에 신뢰성이 있는 방법으로 사용될 수 있음을 증명하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2005.05a
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• pp.427-430
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• 2005

사람의 홍채는 태어날 때 한번 정해지면 평생 변화하지 않는 특성을 가지고 있으며, 개개인별로 모양이 모두 다른 것으로 알려져 있다. 이에, 본 논문에서는 홍채영상 취득시 조명에 의한 동공의 크기 변화에 민감하지 않은 2차원의 홍채패턴을 취득하여, 2D Gabor Wavelet과 Fuzzy LDA를 이용하여 특징 벡터를 추출한다. 인식과정에서는 correlation 계수를 이용하여 서로 다른 홍채의 특징 값에 대해 유사도를 측정하고 유사도가 가장 큰 대상을 찾게 된다. 이때, 4개 방향의 Gabor Wavelet을 거쳐 얻어진 영상에 대해 최고의 값을 인식 대상자로 인정하므로 오 인식 될 확률을 최소화 할 수 있다. 제안한 알고리듬의 유용성을 확인하기 위해 대상자 50명에 대하여 각각 6회씩 촬영한 두 가지 데이터베이스(CASIA, CBNU)를 이용하였으며, 실험 결과 90% 이상의 높은 인식률을 얻었다.

• Journal of Korea Multimedia Society
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• v.3 no.4
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• pp.339-346
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• 2000

Medical image is analyzed to get an anatomical information for diagnostics. Segmentation must be preceded to recognize and determine the lesion more accurately. In this paper, we propose automatic segmentation algorithm for MR brain images using T1-weighted, T2-weighted and PD images complementarily. The proposed segmentation algorithm is first, extracts cerebrum images from 3 input images using cerebrum mask which is made from PD image. And next, find 3D clusters corresponded to cerebrum tissues using scale filtering and 3D clustering in 3D space which is consisted of T1, T2, and PD axis. Cerebrum images are segmented using FCM algorithm with its initial centroid as the 3D cluster's centroid. The proposed algorithm improved segmentation results using accurate cluster centroid as initial value of FCM algorithm and also can get better segmentation results using multi spectral analysis than single spectral analysis.

• Journal of the Korean Wood Science and Technology
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• v.29 no.2
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• pp.91-99
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• 2001

In this study the possibility of classifying wood surface defects by image processing technique was investigated. An algorithm for the classification of wood surface defects, such as knot, check, and bark, on three Korean domestic species, Pinus densiflora, Quercus acutissima, and Carpinus laxiflora was also developed. Filtering was executed to separate dummies from the labels including real defect. Error rates in classifying knots on Pinus densiflora and Quercus acutissima were lower than 1% and error rates. In classifying check and bark in Quercus acutissima and Carpinus laxiflora could be lowered to below 13%.

• Journal of Korea Spatial Information System Society
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• v.10 no.2
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• pp.13-24
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• 2008

A next generation video based car navigation is researched to supplement the drawbacks of existed 2D based navigation and to provide the various services for safety driving. The components of this navigation system could be a load object database, identification module for load lines, and crossroad identification module, etc. In this paper, we proposed the traffic lights and road sign recognition method which can be effectively exploited for crossroad recognition in video-based car navigation systems. The method uses object color information and other spatial features in the video image. The results show average 90% recognition rate from 30m to 60m distance for traffic lights and 97% at 40-90m distance for load sign. The algorithm also achieves 46msec/frame processing time which also indicates the appropriateness of the algorithm in real-time processing.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.6
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• pp.716-721
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• 2003

This paper deals with the iris recognition as one of biometric techniques which are applied to identify a person using his/her behavior or congenital characteristics. The iris of a human eye has a texture that is unique and time invariant for each individual. First, we obtain the feature vector from the 2D iris pattern having a property of size invariant and divide it into 24 sectors which are further through three types of 2D Gabor filters. At the recognition process, we compute the similarity measure based on the correlation values. Here, since we use three different matching values obtained from three different directional Gabor filters and select the maximum value among them, it is possible to minimize the recognition error rate. To show the usefulness of the proposed algorithm, we applied it to a biometric database consisting of 50 iris patterns extracted from 10 subjects and finally get more higher than 90% recognition rate.

• Journal of Digital Convergence
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• v.11 no.3
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• pp.181-187
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• 2013

Moreover a new logistics concept is needed through the sharing information between suppliers and consumers, which maximizes the level of customers service and its flexibility by changing functional-oriented to process-oriented. In other words, Supply Chain Management(SCM) is now considered as a key aspect of business, which controls the flows of information, funds, and goods in the supply chain. Rationalization of transport-delivery system will be one of the most important issues on logistics management to the domestic companies. The companies need the effective delivery system. Especially in the case of delivery system from distribution centers to customers or vendors, it might take a long time to control the delivery system manually because it would be hard to apply the automatic vehicle routing algorithm effectively considering all the practical constraints. Thus this study develops a heuristic algorithm of automatic vehicle delivery support system in terms of grouping by short ranges of vehicle movement utilizing postal coordinates, which satisfies a variety of realistic constraints and reduces controlling time of manual operations.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.5
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• pp.117-123
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• 2003

One of the most important elements in satellite attitude control is sensor technology. Generally, inertial sensors introduce drift and noise which cause continuous errors. Absolute reference is needed to eliminate the problem of the inertial sensors. Star trackers are used primarily for such a purpose. There has been relatively less research effort or ground feasibility test experience on star trackers in the domestic side despite the importance of the associated technologies. In this paper, we re-introduce the basic concept of a star tracker and present the S/W simulator for the star tracker. The star simulator may be used ground test of a star tracker for the basic functioning test or the whole spacecraft test with the star tracker assembled.