• Journal of KIISE:Computing Practices and Letters
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• v.9 no.6
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• pp.635-645
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• 2003

One of very important features that are necessarily supported by clustered parallel computer systems is a single I/O system image in which users can access both the local and remote I/O resources transparently. In this paper, we propose an efficient disk sharing technique supporting a single disk I/O system image architecture. The design separates the I/O subsystem of a cluster into the file system and a set of virtual hard disk drivers. The virtual hard disk driver deals with a hard disk in the remote node as a local hard disk. All services provided by it are performed in the device driver level without any modification of file systems. Users can, therefore, access all the disks in the cluster regardless of their locations. Our virtual hard disk driver is implemented under the linux, and also tested in a linux cluster system. We find by experiments that it can successfully support a single disk I/O space, and at the same time it shows better performance than NFS. We are sure that this paper can be a guideline for single I/O space of other devices to be easily constructed.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.128.1-128.1
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• 2014

잠자리, 벌 등 곤충과 새우, 가재 등 갑각류를 포함하는 절지동물류에서 발견되는 겹눈(compound eye)구조는 볼록한 형태이기 때문에 일반 단일렌즈(single lens)형 눈에 비해 매우 넓은 시야각을 가지며, 깊은 심도를 갖는 특징이 있다. 기존 카메라가 갖기 어려운 겹눈의 독특한 장점으로 인해, 곤충의 눈을 모방하는 연구는 많은 사람들의 주목을 받고 있다. 겹눈구조는 일반적으로 수백에서 수만개의 홑눈(ommatidium)이 모여 다발을 이루고 있으며, 각 홑눈은 겉에서부터 마이크로렌즈 형태의 각막, 수정추, 감간(rhabdom)형태로 이루어져 있다. 따라서 이러한 겹눈구조를 모방하기 위해서는 인공홑눈을 제작하고 이를 반구형으로 배열하는 것이 필수적이다. 그러나 실리콘 반도체를 기반으로 하는 이미지 센서는 딱딱하고 편평하여 굴곡진 형태로 배열이 어렵기 때문에 곤충눈을 모방한 형태의 구조물은 몇몇 연구그룹에서 개발된 사례가 있으나, 이미징이 가능한 곤충눈 시스템의 개발은 보고된 바가 없었다. 본 발표에서는 최근에 연구가 진행되고 있는 플렉서블 전자소자에 기반한 곤충눈을 모방한 이미징 시스템에 대해서 다루고자 한다.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.4
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• pp.95-102
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• 2004

In order to process video data effectively, it is required that the content information of video data is loaded in database and semantic-based retrieval method can be available for various query of users. Currently existent contents-based video retrieval systems search by single method such as annotation-based or feature-based retrieval, and show low search efficiency md requires many efforts of system administrator or annotator because of imperfect automatic processing. In this paper, we propose semantics-based video retrieval system which support semantic retrieval of various users by feature-based retrieval and annotation-based retrieval of massive video data. By user's fundamental query and selection of image for key frame that extracted from query, the agent gives the detail shape for annotation of extracted key frame. Also, key frame selected by user become query image and searches the most similar key frame through feature based retrieval method and optimized comparison area extracting that propose. Therefore, we propose the system that can heighten retrieval efficiency of video data through semantics-based retrieval.

• Journal of the Korea Computer Industry Society
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• v.5 no.2
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• pp.203-216
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• 2004

In order to process video data effectively, it is required that the content information of video data is loaded in database and semantic- based retrieval method can be available for various query of users. Currently existent contents-based video retrieval systems search by single method such as annotation-based or feature-based retrieval, and show low search efficiency and requires many efforts of system administrator or annotator form less perfect automatic processing. In this paper, we propose semantic-based video retrieval system which support semantic retrieval of various users by feature-based retrieval and annotation-based retrieval of massive video data. By user's fundamental query and selection of image for key frame that extracted from query, the agent gives the detail shape for annotation of extracted key frame. Also, key frame selected by user become query image and searches the most similar key frame through feature based retrieval method that propose. Therefore, we design the system that can heighten retrieval efficiency of video data through semantic-based retrieval.

• Journal of Korea Multimedia Society
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• v.9 no.1
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• pp.127-137
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• 2006

In order to process video data effectively, it is required that the content information of video data is loaded in database and semantic- based retrieval method can be available for various query of users. Currently existent contents-based video retrieval systems search by single method such as annotation-based or feature-based retrieval, and show low search efficiency and requires many efforts of system administrator or annotator form less perfect automatic processing. In this paper, we propose semantic-based video retrieval system which support semantic retrieval of various users by feature-based retrieval and annotation-based retrieval of massive video data. By user's fundamental query and selection of image for key frame that extracted from query, the automatic indexing agent gives the detail shape for annotation of extracted key frame. Also, key frame selected by user become query image and searches the most similar key frame through feature based retrieval method that propose. Therefore, we propose the system that can heighten retrieval efficiency of video data through semantic-based retrieval.

• KIISE Transactions on Computing Practices
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• v.22 no.1
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• pp.20-25
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• 2016

With the advent of the era of digital big data, the Hadoop platform has become widely used in various fields. However, the Hadoop MapReduce framework suffers from problems related to the increase of the name node's main memory and map tasks for the processing of large number of small files. In addition, a method for running C++-based tasks in the MapReduce framework is required in order to conjugate GPUs supporting hardware-based data parallelism in the MapReduce framework. Therefore, in this paper, we present a face detection system that generates a sequence file for images to process big data for images in the Hadoop platform. The system also deals with tasks for GPU-based face detection in the MapReduce framework using Hadoop Pipes. We demonstrate a performance increase of around 6.8-fold as compared to a single CPU process.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.103-106
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• 2007

본 논문에서는 얼굴, 홍채 등의 생채정보를 안전하게 은닉하고 효과적으로 은닉정보를 추출할 수 있는 웨이블렛 기반 워터마킹 기법을 제안한다. 얼굴과 홍채의 특징데이터는 Fuzzy-LDA(Fuzzy-Based Linear Discriminant Analysis)를 이용하여 추출하였다. 워터마킹알고리즘은 Wavelet을 이용하여 생체이미지에 생체특징 삽입 이전의 생체 인식율과 워터마킹알고리즘을 거쳐 생체특징을 추출한 후의 인식률 비교를 통해 성능을 평가하였다. 또한 단일생체특징 삽입과 다중생체특징삽입을 통해 단일생체보안과 다중생체보안의 실험을 수행, 평가하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.293-298
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• 2000

최근 3차원 그래픽스 분야는 기존의 단순 이미지의 처리가 아닌 보다 나은 화질과 보다 많은 기법의 도입이 요구되어 지고 있다. 이에 본 논문에서는 가장 기본적인 실감영상의 표현 기법인 텍스쳐 매핑 기법에 대하여 논하였고, 3차원의 객체 공간에서 2차원의 스크린 공간으로의 변환으로 인해 생길 수 있는 문제점과 렌더링 알고리즘에 대해 분석하였으며, 이에 부합하는 렌더링 시스템을 설계, 분석하였다. 또한 본 시스템은 고성능 3차원 그래픽 처리를 위하여 채택되어지고 있는 프로세서-메모리 집적 방식을 이용, 래스터라이징 유닛과 프레임버퍼를 단일 칩으로 구성하여 렌더링과 텍스쳐 매핑 과정에서 발생할 수 있는 지연현상을 제거하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.238-241
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• 2009

정보 과학 기술의 발전과 생활 수준의 향상이 가속화되면서 주변 환경을 구성하는 가구나 공간조차도 정보 통신과 컴퓨터 기능이 내재된 인간과 상호작용할 수 있는 개념으로 확장되고 있다. 또한 비즈니스의 규모가 방대해지면서 협업이 필요성이 증가되는 가운데 단일 사용자에게 맞춰진 표준 데스크탑을 대체할 새로운 기기와 인터페이스에 대한 요구가 증가하고 있다. 본 연구에서는 이런 패러다임에 맞춰 선호되고 있는 테이블탑 컴퓨팅을 다수의 LCD와 PC를 포함하는 분산 하드웨어 방식의 고해상도 대형 디스플레이로 구성하고, 다중 사용자의 입력을 동시적으로 처리할 수 있는 적외선 카메라를 활용한 마커 인식 기반의 탠저블 인터페이스를 개발하였다. 그리고 이 시스템에서 동작하는 고해상도 이미지 뷰어와 퍼베이스브 블록 격파 게임 응용프로그램을 구현하였다.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.3
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• pp.245-252
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• 2012

The purpose of this study was to evaluate the influence of glide path on canal centering ratio after instrumentation with different single file systems; WaveOne and Reciproc. Reciproc R25 (VDW), WaveOne Primary (Dentsply Maillefer) and PathFile #13, 16, 19 (Dentsply Maillefer) were used in this study. In no glide path groups, Reciproc files and WaveOne files used for canal preparation without glide path. In glide path groups, the PathFile were used before canal preparation. Methylene blue dye was introduced into the canal to obtain a clear pre-instrumentation image. Pre-instrumentation images and post-instrumentation images were scanned using Epson Perfection V700 Photo scanner (Epson, Nagano, Japan). Transparencies of post-instrumentation images were changed and superimposed on pre-instrumentation images using Adobe Photoshop CS 3 (Adobe Systems Incorporated, San Jose, CA, USA). The centering ratio was calculated for each instrumented canal using the following formula: CR=|X1-X2|/Y. It was statistically analyzed using two-way ANOVA at 95% confidential level. The centering ratio in glide path groups were significant less than it in no glide path groups at 3, 4, 5 and 6 mm level. Except 1 and 6 mm level, WaveOne groups had significant less centering ration than Reciproc groups. At 6 mm level, there was no significant difference between WaveOne and Reciproc. In the limitation of this study, creation of a previous glide path before reciprocating motion instrumentation in curved canal appears to be appropriate and WaveOne system can be used for preparation of curved canal without severe aberrations.