• Journal of Digital Convergence
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• v.10 no.7
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• pp.179-184
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• 2012

The ultimate purpose of cities is 'the enhancement of quality of life in city'. In order to achieve this, it is required to optimize the Ontology-driven ubiquitous services included in the U-City and UIS of regions and communities and so on. Almost U-Service's contents are related to spatial or temporal extent. So it is important to design Spatio-temporal event schema for efficient access to U-City. There is a rapid change into an urban society in the shape of Ontology-driven ubiquitous services in which a content on a region or an incident is newly reconstructed through various ideas with the influence of the ubiquitous environment.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.5
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• pp.27-38
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• 2007

One of the most important security issues of e-mail service is user privacy. Currently, various security protocols, like PGP(pretty Good Privacy), S/MIME(Secure/Multipurpose Internet Mail Extension), have been proposed. These protocols, however, do not provide forward secrecy. Recently, some security protocols that provide forward secrecy were proposed. But all of them require changes to the current e-mail infrastructure. Moreover, contrary to authors' intention, some of them do not actually provide perfect forward secrecy. In this paper, we propose a new practical e-mail security protocol. The proposed protocol provides perfect forward secrecy and uses a practical e-mail model that dose not require any changes to existing e-mail servers. It encrypts and authenticates messages efficiently using elliptic curve based signcryption scheme. In addition, we provide a way to send secure group e-mails.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.1354-1360
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• 2006

최근 놀라운 성장을 거듭하고 있는 지능형 로봇(Intelligent Robot) 기술은 기존의 주요 활용 분야였던 산업현장이나 연구실과 같은 전문가적 영역을 넘어서 지능형 엔터테인먼트(Entertainment)로봇이나 청소기 로봇의 예에서 볼 수 있듯이 인간의 주요 일상 생활 공간인 가정이나 공공기관의 서비스 분야로 점차 그 활용 영역을 넓혀가고 있다. 학습 보조 교사 도우미 로봇의 개발은 초등학교 교육 현장이 당면하고있는 각종 현안들을 로봇의 활용을 통해서 해결하고자하는 실용적인 목적에서 출발 했다. 이러한 관점에서 볼때 로봇 디자이너의 역할은 전체 개발 프로세스의 말단부에서 로봇 시스템의 외장(Appearance)을 마무리하는 역할을 넘어서 구체적 로봇시스템의 개발에 선행하여 학습보조 교사 도우미 로봇의 잠재적 활용 주체인 학생, 교사, 학부모의 입장에서 각 주체들의 내재적, 외재적 욕구를 효과적으로 만족 시킬 수있는 활용 시나리오(Application Scenario)를 도출, 개발 프로세스 전반에 걸쳐 각 개발 주체들에게 일관된 비젼(vision)과 이미지(image)를 제시하는것이라고 생각되었다. 본연구에서는 학습보조 교사 도우미 로봇 디자인 과제에 있어서 사용자 관찰(User Observation), 유저 다이어리(User Diary), 포커스그룹 인터뷰(F.G.I)등을 바탕으로 로봇의 역할 모델중심, 서비스 영역 중심, 초등학교 교육이념 구현 중심 등 3가지의 서로 다른 컨셉의 로봇 활용 시나리오(Application Scenario)를 제안하였다. 본 연구 결과는 현재 초기 단계에 있는 로봇 디자인 분야의 현실을 감안할때 전체 로봇 개발 프로세스내에서의 향후 산업 디자인이 수행해야 할 역할을 명확하게 보여준다는 점에서 그 의의가 있으며 관련 분야의 연구 활성화에 기여할 것으로 기대된다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.7
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• pp.1564-1572
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• 2011

In this paper, we propose a new histogram based hand recognition algorithm for augmented reality. Hand recognition system makes it possible a useful interaction between an user and computer. However, there is difficulty in vision-based hand gesture recognition with viewing angle dependency due to the complexity of human hand shape. A new hand recognition system proposed in this paper is based on the features from hand geometry. The proposed recognition system consists of two steps. In the first step, hand region is extracted from the image captured by a camera and then hand gestures are recognized in the second step. At first, we extract hand region by deleting background and using skin color information. Then we recognize hand shape by determining hand feature point using histogram of the obtained hand region. Finally, we design a augmented reality system by controlling a 3D object with the recognized hand gesture. Experimental results show that the proposed algorithm gives more than 91% accuracy for the hand recognition with less computational power.

• Journal of Korea Multimedia Society
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• v.7 no.11
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• pp.1597-1609
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• 2004

A lot of lipreading system has been proposed to compensate the rate of speech recognition dropped in a noisy environment. Previous lipreading systems work on some specific conditions such as artificial lighting and predefined background color. In this paper, we propose a real-time lipreading system which allows the motion of a speaker and relaxes the restriction on the condition for color and lighting. The proposed system extracts face and lip region from input video sequence captured with a common PC camera and essential visual information in real-time. It recognizes utterance words by using the visual information in real-time. It uses the hue histogram model to extract face and lip region. It uses mean shift algorithm to track the face of a moving speaker. It uses PCA(Principal Component Analysis) to extract the visual information for learning and testing. Also, it uses HMM(Hidden Markov Model) as a recognition algorithm. The experimental results show that our system could get the recognition rate of 90% in case of speaker dependent lipreading and increase the rate of speech recognition up to 40～85% according to the noise level when it is combined with audio speech recognition.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.4
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• pp.159-166
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• 2016

In this paper, an active object tracking system basing on the pan/tilt-embedded stereo camera system is suggested and implemented. In the proposed system, once the face area of a target is detected from the input stereo image by using a YCbCr color model and phase-type correlation scheme and then, using this data as well as the geometric information of the tracking system, the distance and 3D information of the target are effectively extracted in real-time. Basing on these extracted data the pan/tilted-embedded stereo camera system is adaptively controlled and as a result, the proposed system can track the target adaptively under the various circumstance of the target. From some experiments using 480 frames of the test input stereo image, it is analyzed that a standard variation between the measured and computed the estimated target's height and an error ratio between the measured and computed 3D coordinate values of the target is also kept to be very low value of 1.03 and 1.18% on average, respectively. From these good experimental results a possibility of implementing a new real-time intelligent stereo target tracking and surveillance system using the proposed scheme is finally suggested.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.11
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• pp.79-88
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• 1999

In this paper we address the tracking method which tracks only target object in image sequence including moving object. We use a contour tracking algorithm based on intensity and motion boundaries. The motion of the moving object contour in the image is assumed to be well describable by an affine motion model with a translation, a change in scale and a rotation. The moving object contour is represented by B-spline, the position and motion of which is estimated along the image sequence. we use pattern recognition to identify target object. In order to use linear Kalman Filters we decompose the estimation process into two filters. One is estimating the affine motion parameters and the other the shape of moving object contour. In some experiments with dial plate we show that this method enables us to obtain the robust motion estimates and tracking trajectories even in case of including obstructive object.