• Journal of Korea Society of Industrial Information Systems
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• v.6 no.1
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• pp.33-38
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• 2001

In this paper, we present an image retrieval system using shape features. The preprocessing to gain shape feature includes edge extraction using chain code. The shape features consist of center of mass, standard deviation, ratio of major axis and minor axis length. The similarity is estimated as comparing the features of query image with the features of images in database. Thus, the candidates of images are retrieved according to the order of similarity. The result of an experimentation is dullness for scale, rotation and translation. We evaluate the performance of shape features for image retrieval on a database with over 170 images. The Recall and the Precision is each 0.72 and 0.83 in the result of average experiment. So the proposed method is presented useful method.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.4
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• pp.551-559
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• 2017

In this paper, a real-time training method to improve the performance of bearing fault diagnosis. The traditional bearing fault diagnosis cannot classify a condition which is not trained by the classifier. The proposed 4-step method trains and recognizes new condition in real-time, thereby it can classify the condition accurately. In the first step, we calculate the maximum distance value for each class by calculating a Euclidean distance between a feature vector of each class and a centroid of the corresponding class in the training information. In the second step, we calculate a Euclidean distance between a feature vector of new acquired data and a centroid of each class, and then compare with the allowed maximum distance of each class. In the third step, if the distance between a feature vector of new acquired data and a centroid of each class is larger than the allowed maximum distance of each class, we define that it is data of new condition and increase count of new condition. In the last step, if the count of new condition is over 10, newly acquired 10 data are assigned as a new class and then conduct re-training the classifier. To verify the performance of the proposed method, bearing fault data from a rotating machine was utilized.

• Phonetics and Speech Sciences
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• v.16 no.1
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• pp.33-40
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• 2024

This study investigated acoustic features in spectral moment analysis, comparing accurate articulations with distortions of alveolar fricatives such as dentalization, palatalization, and lateralization. A retrospective analysis was conducted on speech samples from 61 children (mean age: 5.6±1.5 years, 19 females, 42 males) using the Assessment of Phonology & Articulation for Children (APAC) and Urimal-test of Articulation and Phonology I (U-TAP I). Spectral moment analysis was applied to 169 speech samples. The results revealed that the center of gravity of accurate articulations was higher than that of palatalization, while palatalization was lower than dentalization. The variance of dentalization was higher than that of both accurate articulations and palatalization. The skewness of dentalization was higher than that of accurate articulations, and the skewness of palatalization was higher than that of accurate articulations. The kurtosis of palatalization was higher than that of both accurate articulations and dentalization. No significant differences were observed for the position of fricatives (initial, medial) and tense type (plain, tense) across all variables of spectral moment analysis for each distortion type. This study confirmed distinct patterns in center of gravity, variance, skewness, and kurtosis depending on the type of alveolar fricative distortion. The objective values provided in this study will serve as foundational data for diagnosing alveolar fricative distortions in children with speech sound disorders.

• Radiation Oncology Journal
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• v.25 no.1
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• pp.54-61
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• 2007

[ $\underline{Purpose}$ ]: The purpose of this study is to develop a practical method for determining accurate marker positions for prostate cancer radiotherapy using CT images and kV x-ray images obtained from the use of the on- board imager (OBI). $\underline{Materials\;and\;Methods}$: Three gold seed markers were implanted into the reference position inside a prostate gland by a urologist. Multiple digital image processing techniques were used to determine seed marker position and the center-of-mass (COM) technique was employed to determine a representative reference seed marker position. A setup discrepancy can be estimated by comparing a computed $COM_{OBI}$ with the reference $COM_{CT}$. A proposed algorithm was applied to a seed phantom and to four prostate cancer patients with seed implants treated in our clinic. $\underline{Results}$: In the phantom study, the calculated $COM_{CT}$ and $COM_{OBI}$ agreed with $COM_{actual}$ within a millimeter. The algorithm also could localize each seed marker correctly and calculated $COM_{CT}$ and $COM_{OBI}$ for all CT and kV x-ray image sets, respectively. Discrepancies of setup errors between 2D-2D matching results using the OBI application and results using the proposed algorithm were less than one millimeter for each axis. The setup error of each patient was in the range of $0.1{\pm}2.7{\sim}1.8{\pm}6.6\;mm$ in the AP direction, $0.8{\pm}1.6{\sim}2.0{\pm}2.7\;mm$ in the SI direction and $-0.9{\pm}1.5{\sim}2.8{\pm}3.0\;mm$ in the lateral direction, even though the setup error was quite patient dependent. $\underline{Conclusion}$: As it took less than 10 seconds to evaluate a setup discrepancy, it can be helpful to reduce the setup correction time while minimizing subjective factors that may be user dependent. However, the on-line correction process should be integrated into the treatment machine control system for a more reliable procedure.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1966-1972
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• 2011

Optical flow estimation based on multi constraint approaches is frequently used for recognition of moving objects. This paper proposed the method to monitor passenger boarding using image processing when a train is operated based on Automatic Train Operation(ATO). The movement of passenger can be detected to compare two images, one is a basic image and another is immediately captured by CCTV. Optical Flow helps to find the movement of passenger when two images are compared. The movement of passenger is one of important informations for ATO system because it needs to decide door status.

• Journal of Korea Multimedia Society
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• v.13 no.2
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• pp.316-323
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• 2010

In this paper, we propose fingertip extraction and hand motion recognition method for augmented reality applications. First, an input image is transformed into HSV color space from RGB color space. A hand area is segmented using double thresholding of H, S value, region growing, and connected component analysis. Next, the end points of the index finger and thumb are extracted using morphology operation and subtraction for a virtual keyboard and mouse interface. Finally, the angle between the end points of the index finger and thumb with respect to the center of mass point of the palm is calculated to detect the touch between the index finger and thumb for implementing the click of a mouse button. Experimental results on various input images showed that our method segments the hand, fingertips, and recognizes the movements of the hand fast and accurately. Proposed methods can be used the input interface for augmented reality applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.586-589
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• 2015

A computer presentation system by using hand-motion identification rules is proposed. To identify hand motions of a presenter, a face region is extracted first using haar classifier. A motion status(patterns) and position of hands is discriminated using the center of gravities of user's face and hand after segmenting the hand area on the YCbCr color model. User's hand is applied to the motion detection rules and then presentation control command is then executed. The proposed system utilizes the motion identification rules without the use of additional equipment and it is then capable of controlling the presentation and does not depend on the complexity of the background. The proposed algorithm confirmed the stable control operation via the presentation of the experiment in the dark illumination range of indoor atmosphere (lx) 15-20-30.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.427-428
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• 2007

컴퓨터 비전을 이용한 이진 영상 데이터 처리는 사용자가 원하는 객체를 배경과 분리하여 추출하는 데에 유용하며 객체 위치 검출에는 테두리 검출(edge detection), 센트로이드 검출 (centroid detection) 등 다양한 기법들이 사용되어 왔다. 연속해서 움직이는 객체의 위치를 테두리 검출 기법을 이용하여 추종 시, 조명과 환경 잡음에 민감한 영상 데이터의 특성상 객체의 테두리 부분은 매 프레임마다 조금씩 차이가 있어 위치를 검출하는 데에 오차가 발생하기 쉽다. 그러나 센트로이드 기법으로 구할 경우 많은 픽셀의 무게중심을 구하는 것이므로 그 오차를 줄여 빠르고 정확한 위치 검출에 유용하다. 본 논문에서는 LabVIEW를 이용하여 진자운동 하는 물체의 센트로이드 점을 구하여 실시간 위치 검출을 구현한다.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.635-640
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• 2003

본 논문에서는 일본 차량 번호판 인식에 적응적 탬플릿 마스킹 방법을 이용하여 번호판 문자, 숫자를 분할하고 패턴벡터기법을 이용하여 인식하는 방법을 제안하였다 주, 야간과 거리에 따른 일본 차량 번호판 영상을 입력받아 전처리 과정을 수행한 후 에지 정보와 명도값 변화의 빈도수를 이용하여 번호판 영역을 검출하였다 검출된 번호판 영역에서 각 문자 및 숫자의 위치정보와 적응적 탬플릿을 이용하여 분할하고 번호판의 지역문자를 무게중심 패턴으로 분류 한 다음 크기와 이동에 무관한 특실을 가지는 패턴 벡터를 적용하여 문자를 인식하였으며, 숫자는 Four Segment Pattern을 이용하여 인식하도록 하였다 본 논문에서 제안한 방법을 실제 일관 차량 번호판 인식에 적용한 결과 98.8％ 추출율과 96.6％의 인식율을 나타내었다.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.827-830
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• 2004

현재까지도 대부분의 필기체 한글 인식은 완벽한 분할을 가정하여 개발되고 있으며 한글 분할 그 자체에 대한 관심은 매우 낮은 편이다. 또한 한글은 자소의 모아쓰기 형태를 갖고 있어 문자내에 여백이 존재할 뿐만 아니라 문자와 문자 사이의 접촉되는 특징이 흔히 발생되기 때문에 기존의 영문자에 사용된 방법을 그대로 직접 적용하기에는 많은 어려움이 있다. 본 논문에서는 무제약 필기체 한글을 분할하기 위하여 가상 분할경로를 이용하는 방법을 제안한다. 제안된 방법은 기존의 분할 방법들이 갖는 직선화된 분할경로 뿐만 아니라 문자내에 존재하는 여백의 정보를 활용하여 꺽은선 분할경로를 주로 이용하는데 특징이 있다. 분할과정은 크게 2단계로 구성되는데 첫 번째 단계는 입력받은 한글 문자열에 대한 전처리 과정과 수직투영을 통해 직선화된 분할경로를 찾고 이에 따라 쉽게 분할 가능한 문자와 중첩되거나 접촉된 문자를 구분하여 다음 단계의 분할대상으로 결정한다. 두 번째 단계에서는 다양한 가상의 꺽은선 분할경로를 생성하기 위하여 각 문자에서 특징점을 추출하고, 인접한 특징점들 간의 무게 중심점을 찾아서 더 세밀한 경로 생성을 함으로서 가장 최상의 분할경로를 결정한다.