• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.35.1-35.1
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• 2008

The importance on the simulation of earth observation optical payloads has been recently emphasized in order to estimate on-orbit imaging performance of the payloads. The estimation should consider all aspects of payload development; design, manufacture, test, assembly, launch and space environment. Until recently several studies have been focused the evaluation of the individual factors rather than the integrated. This paper presents the development of an integrated payload simulator. The simulator analyzes the payload imaging performance based on MTF(Modulation Transfer Function) calculations of the major factors (Diffraction, Aberration, Detector integration, Image motion and etc.) and the simulator can generate realistic artificial earth images as taken by defined earth observation payloads. The simulator is developed for the use of evaluating pre- and post-launch imaging performance and assisting on-board calibration of COMPSAT-3.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.320-323
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• 2011

최근 전자기술의 발달로 인해 인쇄 회로 기판(Printed Circuit Board)이 정밀화되고 세분화됨에 따라 고도로 집약되어 육안에 의한 시각검사 방법이 어려워지고 있다. 이에 따라 컴퓨터 시각 기술을 이용한 자동시각검사가 점차 늘어가는 추세다. 이러한 PCB의 설계 또는 검사 시 참조할 이미지를 만드는 방법 중 하나로 Gerber Interface로 표현된 PCB용 CAD파일인 거버파일을 이용하여 디지털 이미지를 생성하는 법이 널리 이용되고 있다. 반면 이러한 파일 및 이미지는 상호간에 인과관계(causality)를 가지며, 이미지 유출시 그 피해가 크다. 따라서 생성된 이미지를 효과적으로 보호하고 관리해야할 필요가 있다. 본 논문에서 상기의 인과관계를 이용하여 이를 관리하고 보호하는 이미지 권한관리 기법을 제안한다.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.60.2-60.2
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• 2016

We present recent results of very long baseline interferometry (VLBI) observations of gamma-ray bright active galactic nuclei (AGNs) using Korean VLBI Network (KVN) at 22, 43, 86, and 129~GHz bands, which are part of a KVN key science program; Interferometric Monitoring of Gamma-ray Bright AGNs (iMOGABA). We selected a total of 34 radio-loud AGNs of which 30 sources are gamma-ray bright AGNs, including 24 sources monitored by the Fermi Gamma-ray Space Telescope using the Large Area Telescope on board. The selected sources consist of 24 quasars, 7 BL Lacs, and 3 radio galaxies. In this talk, we summarize recent results of the iMOGABA, including results of single-epoch multi-frequency VLBI observations of the target sources, conducted during a 24-hr session on 2013 November 19 and 20. All observed sources were detected and imaged at all frequency bands with or without a frequency phase transfer technique which enabled to detect and image 12 faint sources at 129 GHz, except for 0218+357 which was detected for only one baseline at all frequency bands.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.406-408
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• 2001

In this thesis, a video tracker with a TMS320C31 DSP is designed and implemented. It is intended to work with PC through PCI Bus and can be used in real-time applications. The DSP board is capable of grabbing image data from camera, and calculating the position of a target, and tracking its movement. The tracking situation can be displayed in a PC monitor and displacement of the movement is fed back to pan and tilt the camera. Experimental results show that the tracker implemented here works well in real applications.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.11
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• pp.20-24
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• 1997

We have successfully fabricated high power (~20W) laser diode array, which are useful for pumping Nd:YAG lasers. The laser diode aray has 20 100.mu.m-wide cahnnels of which space was adjusted to 350.mu.m to improve thermal characteristics. And channel width is 100.mu.m. For an uncoated LD array, the output power of 15.66W has been obtained at 41A under quasi-CW operation, which results in about 0.42W/A slope efficiency. After aR(5%) and HR (95%) coatings on both facets, the output power was improved up to 21.18W at 40A under the same operation as above and the slope efficiency was 0.795W/A. On the other hand, by using a near field measurement system consisting of objective lens, eyepiece, CCD camera and image processing board, the typical near field patten of 1*20 LD array was observed.

• Journal of Institute of Control, Robotics and Systems
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• v.2 no.3
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• pp.200-208
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• 1996

This paper describes the mechanism, guidance, sensor system, and navigation algorithm of METRO, a free ranging mobile robot. METRO is designed for use in structured surroundings or factory environments rather than unstructured natural environments. An overview of the physical configuration of the mobile robot is presented as well as a description of its sensor system, an omnidirectional laser range finder. Except for the global path planning algorithm, a guidance and a navigation algorithm with a local path planning algorithm are used to navigate the mobile robot. In METRO the computer support is divided into a supervisor with image processing and local path planning and a slave with motor control. The free ranging mobile robot is self-controlled and all processing being performed on board.

• IEMEK Journal of Embedded Systems and Applications
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• v.11 no.4
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• pp.251-257
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• 2016

The multi-core technology has become pervasive in embedded systems. An implementation of the Doppler Beam Sharpening algorithm that improves the azimuth resolution by using doppler frequency shift is possible only in multi-core environment because of the amount of calculation. In this paper, we design of multi-core architecture for a real time implementation of DBS algorithm. And based on designed structure, we produce a DBS image on P4080 board.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.6
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• pp.879-884
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• 2012

Photoacoustic Tomography (PAT) is a promising medical imaging modality by reason of its particularity. It combines optical imaging contrast of optical imaging with the spatial resolution of ultrasound imaging and can demonstrate change of biological feature in an image. For that reason, many studies are in progress to apply this technic for diagnosis. But, real-time PAT system is necessary to confirm a biological reaction induced by external stimulation immediately. Thus, we developed a real-time PAT system using linear array transducer and self-developed Data acquisition board (DAQ) resources, To evaluate the feasibility and performance of our proposed system, two type of phantom test were also performed. As a result of those experiments, the proposed system shows enough performance and confirm its usefulness.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.11a
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• pp.123-134
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• 2000

In this study, adapted Turbo Coding Algorithm for reducing communication error of fire detection system for marine vessels, especially image transmission. and proposed decoding speed increasing method of Turbo Coding Algorithm. The results are as follows : 1) Confirmed that a Turbo Code is so useful methods for reducing communication error in lots of noise environments. 2) Proposed technology in this study of speed increasing method of Turbo Coding Algorithm proved 2 times speed up effect than normal Turbo Code and communication error reducing as well in the board made by VHDL software & chips of ALTER Company.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.15-17
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• 1999

영상을 실시간으로 처리하기 위한 연구들이 다양한 방법으로 진행되어 왔다. 실현 가능한 접근 방법중 영상관련 프로그램의 실시간 처리를 수행하기 위해 전용 이미지 처리 보드를 제작하는 방법이 있다. 본 논문에서는 다양한 영상 응용프로그램(얼굴인식, 렌더링, 문서 인식 등)을 수행할 수 있는 범용 영상보드의 설계 및 다양한 응용프로그램들을 개인용 컴퓨터에서 사용할 수 있도록 범용 영상보드에 적합한 Windows NT용 디바이스 드라이버를 설계하는 방법을 제시한다.