• Journal of the Korea Computer Graphics Society
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• v.6 no.1
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• pp.19-27
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• 2000

This paper proposes a non-self-intersecting multiresolution deformable model to extract and reconstruct three-dimensional boundaries of objects from volumetric data. Deformable models offer an attractive method for extracting and reconstructing the boundary surfaces. However, convensional deformable models have three limitations- sensitivity to model initialization, difficulties in dealing with severe object concavities, and model self-intersections. We address the initialization problem by multiresolution model representation, which progressively refines the deformable model based on multiresolution volumetric data in order to extract the boundaries of the objects in a coarse-to-fine fashion. The concavity problem is addressed by mesh size regularization, which matches its size to the unit voxel of the volumetric data. We solve the model self-intersection problem by including a non-self-intersecting force among the customary internal and external forces in the physics-based formulation. This paper presents results of applying our new deformable model to extracting a sphere surface with concavities from a computer-generated volume data and a brain cortical surface from a MR volume data.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.461-468
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• 2008

The needs for visualizing interactive multimedia contents on portable devices with realistic three dimensional shapes are increasing as new ubiquitous services are coming into reality. Especially in digital fashion applications with virtual reality technologies for clothes of various forms on different avatars, it is required to provide very high quality visual models over mobile networks. Due to limited network bandwidths and memory spaces of portable devices, it is very difficult to transmit visual data effectively and render realistic appearance of three dimensional images. In this thesis, we propose a compression method to reduce three dimensional data for digital fashion applications. The three dimensional model includes animation of avatar which require very large amounts of data over time. Our proposed method utilizes temporal and spatial coherence of animation data, to reduce the amount. By grouping vertices from three dimensional models, the entire animation is represented by a movement path of a few representative vertices. The existing three dimensional model compression approaches can get benefits from the proposed method by reducing the compression sources through grouping. We expect that the proposed method to be applied not only to three dimensional garment animations but also to generic deformable objects.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.11
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• pp.137-146
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• 2015

In this paper, we propose a pothole detection method using various features of intensity and motion. Segmentation, decision steps of pothole detection are processed according to the values which are derived from feature characteristics. For segmentation using intensity, we use a binarization method using histogram to separate pothole region from background. For segmentation using motion, we filter using high pass filter and get standard deviation value. This value is divided by regression value according to camera environment such as photographing angle, height, velocity, etc. We get binary image by histogram based binarization. For decision, candidate regions are decided whether pothole or not using comparison of candidate and background's features. Experimental results show that our proposed pothole detection method has better results than existing methods and good performance in discrimination between pothole and similar patterns.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.6
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• pp.1-8
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• 2021

The performance of hidden camera cameras is improving day by day due to miniaturization and advanced technology integration according to the speed of technological development of smartphones. As this external networking computing environment is advanced and diversified, exposure to hidden cameras in addition to general safety cameras is also increasing. On the other hand, the technology for detecting and preventing hidden cameras is not keeping up with the development and speed of these hidden cameras. Therefore, in this study, the heat of the hidden camera was detected using infrared thermal detection technology based on general image and thermal image synthesis technology, and the reflectance of each wavelength according to the difference in ambient temperature was analyzed to reduce the false positive rate.

• Information and Communications Magazine
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• v.15 no.12
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• pp.97-113
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• 1998

사회경제의 성장에 따른 수요 증가 및 서비스 다양화추세에 따라 음성통신, 데이터통신 및 간단한 영상통신 등을 서비스하기 위한 통신망이 구축, 발전되어 왔다. 다양한 종류의 멀티미디어 서비스가 하나의 통신매체를 통하여 송 수신될 것으로 예측되며, 이를 실현하기 위해서는 무엇보다도 가입자 댁내에 설치되는 구내통신선로설비의 고도화가 필수적이다. 특히 보다 빠른 속도의 다양한 정보통신서비스를 이용하고자 하는 가입자의 욕구증대와 이를 가능하게 하는 혁신적인 기술발전이 결합하여 가입자 댁내 어디서나 다양한 멀티미디어 서비스를 편리하게 이용할 수 있는 구내배선시스템이 초고속 정보통신망시대의 고부가가치를 창출하는 주력사업으로 부상함에 따라 이에 대한 연구개발이 선진국간에 경쟁력으로 진행 중에 있다. 선진국의 기술개발과 표준화 동향에 대하여 간략히 고찰 한 후, 21세기 정보사회에 대비하기 위하여 현재 정부가 추진중인 구내통신선로설비 기술개발 및 표준화 계획을 간략히 소개하고 향후 기술개발일정과 국제표준과 연계한 표준화 계획을 제시하고자 한다.

• Journal of Digital Contents Society
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• v.6 no.1
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• pp.63-68
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• 2005

Today, Korean Society have stood on the transformation of Globalization and information. Under these radical changes, the Korean church faced the crisis of decline. In fact, decreasing population of new generation in the church who lead digital age makes the future of Korean church look black. This research tried to suggest mission strategy for new generation through develop worship contents using multimedia.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.70.2-70.2
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• 2018

KMTNet에서는 프로젝트의 소개와 운영현황 등 파악하기 위해 웹서비스를 운영하고 있다. 홈페이지(http://kmtnet.kasi.re.kr; 국문, 영문)에는 최신 뉴스와 공지사항, 실시간 모니터링 영상 및 기상정보, 관측일정, 관측자료 공개, 활용성과 등을 게시 하였고, 관측 결과와 운영 정보 관리를 위해서 모니터링 홈페이지(kmtnet-monitor)를 제작하였다. KMTNet은 남반구 3개 관측소에 상주하는 현지 관측자에 의해 관측이 이루어지기 때문에, 국내 연구자가 남반구 관측소 현황을 파악할 수 있는 모니터링 시스템이 필수적이다. 웹서비스에 실시간 기상과 관측자료 전송속도를 함께 표시하여 관측 진행 여부를 확인할 수 있으며, 관측일지를 데이터베이스화하여 망원경/카메라/관측돔의 이상 유무, 관측 현황, 기상/시상 통계 등으로 활용하고 있다. 여기서는 지금까지 개발한 웹 서비스를 소개하고 앞으로 관측소 운영에 유용한 정보와 웹 서비스의 발전 방향에 대해 논의하고자 한다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1539-1540
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• 2015

본 연구는 가공 활선 송전선로의 이상 진단을 위한 시스템 개발에 관한 것으로 송전 철탑 경간내에 설치되어 있는 송전선을 주행하며 전선의 내부 또는 외부의 열화를 확인하기 위한 것이다. 본 연구에 의한 시스템은 지상으로부터 30m 이상의 높이에서 설치되어 운행되기 때문에 바람에 의해 낙하되지 않도록 구성하였다. 또한 복도체 또는 4도체 선로를 주행하도록 설계하였으며 345kV 고압에서도 전계 및 자계의 영향을 받지 않도록 설계하였다. 전선의 이상 검지를 위해서 카메라를 설치하여 얻어진 데이터를 영상 처리 하여 이상 부위에 대한 에너지 변화를 관찰하여 이상 유무를 판단하도록 하였다. 완성된 시스템은 설치 및 이동을 위해서 경량화 시켰으며 분해 조립이 쉽도록 구성하였다. 본 시스템의 현장 적용에 의한 실험 결과 1m/sec의 이동 속도에서 1mm 이하의 스크래치에 대하여 검출이 가능하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.7 no.3
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• pp.125-129
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• 1982

Most A/D converters which encode baseband signals of several magahertz band width to accuracies such as 8 bits are complez and therefore expensive. This letter suggests that a simple fast digital encoder can be formed the combination of V.C.O. and digital discriminator, automatically elimnating the complex logic process of conventional fast baseband A/D converters. The techique is suitable for encoding video signals to 8bits.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10A
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• pp.1555-1562
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• 1999

Various video rate control techniques have been proposed for the transmission of video under fixed channel capacity. In most techniques, the coding parameters and quantizer scaling factors are determined based on information derived from previously coded data. In this paper, an successfully used for video rate-control. Experimental results show that the proposed prediction-based rate control scheme can efficiently regulate the bit-rate caused by dramatic scene change and have better PSNR performance than the TM5 rate control mechanism.