• Journal of the Korean Society for Railway
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• v.12 no.4
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• pp.548-556
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• 2009

In order to evaluate applicability of rock cut-slope investigation system, typical clinometer and photogrammetry investigation system were used for rock slopes; first for 7 discontinuities, and secondly, 10 discontinuities, and the results were compared. The first verification was performed depending on discontinuity joint shapes and slope angles, and the second verification was performed depending on shot time and shot locations. The results showed that differences of dip direction $1^{\circ}{\sim}4^{\circ}$, dip $0^{\circ}{\sim}4^{\circ}$. In the second verification test, the differences of dip direction was $0^{\circ}{\sim}6^{\circ}$, and dip $0^{\circ}{\sim}6^{\circ}$. The photogrammetry method for rock slope survey system is quite reliable when clinometer generally shows ${\pm}10^{\circ}$ errors due to surface roughness and investigator.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.2 no.1 s.2
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• pp.93-100
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• 2003

In this farer, An ADSRC(Advanced Dedicated Short Range Communication) packet communication system developed by ETRI is introduced. The ADSRC system has been developed to provide high-speed, short-range wireless racket communication in roadside environment for mobile office services. The requirements of the ADSRC system for mobile office services and the system design specification to meet them with regard to mobile of nce environment are discussed. The ADSRC packet communication systems consist of the MAC(Medium Access Control) Processor block the OFDM() modem block and the RF block. The MAC processor block handles medium access control. The OFDM modem transmits data packets at up to 24Mbps adaptively and recovers the data from RF block. The ADSRC packet communication system architecture is described.

• Proceedings of the Korean Society of Computer Information Conference
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• 2019.07a
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• pp.443-444
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• 2019

본 논문에서는 라즈베리파이(Raspberry Pi)와 실시간 객체 감지 기술인 YOLO를 이용한 전기차충전기앞불법주차 경고 영상인식 시스템을 제안한다. 최근 전기 자동차의 사용과 더불어 충전 인프라는 점점 늘어나는 중이지만, 여전히 전기차 충전기는 많지 않은 것이 현실이다. 전국 1,000여 곳이 넘는 전기차 충전소에 대해 법령으로 인한 규제를 시행 중임에도 불구하고 불법주차를 하는 일반차 오너들은 여전히 많다. 이로 인해 전기차 오너들은 충전에 많은 불편함이 있다. 이 시스템은 전기 자동차의 번호판을 인식하여 실시간 객체 감지 딥러닝 기법인 YOLO를 이용해 전기 자동차의 번호판에 특정 부분을 인식하고 특정 부분이 없는 일반 자동차가 전기차 충전기 앞 불법 주차를 하게 되면 부저와 LED경고를 통해 주차된 일반 차량에게 경고를 하여, 불법 주차자와 더불어 주변을 지나가는 행인들에게도 전기차 앞 불법 주차에 대해 각인을 시켜줄 수 있는 시스템이다.

• Current Industrial and Technological Trends in Aerospace
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• v.8 no.1
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• pp.86-95
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• 2010

Flight termination system(FTS) is used to terminate safely the launch vehicle's flight when it faces an emergency situation by transmitting termination command from ground FTS. RCC standard IRIG tone method has been used widely for FTS commands method in foreign ranges and Naro Space Center, but this method has a weakness for security of command signal. Therefore RCC had studied more secured EFTS standard and chose CPFSK digital modulation method. This paper describes basic concept and types of FTS and FTS types which foreign ranges had applied and describes standardization of EFTS in the U.S. based on RCC EFTS study reports.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.190-191
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• 2023

자율운항선박 원격제어시스템은 선박운항상태모니터링시스템, 통신시스템, 선박제어시스템으로 구성되어 있다. 육상제어센터는 상기 개별시스템을 결합한 통합시스템으로 이루어졌으며, 지난 1차, 2차 연안항해 시, 실습선과 육상제어센터간의 육상제어에 필요한 정보의 송수신여부를 확인하고자 테스트를 시행하고, 그 결과를 통해 일부 시스템의 문제점을 식별하였다. 본 연구에서는 식별된 문제점들을 해결하기 위한 방안을 제시하였으며, 차후 진행되는 연안항해 시 시스템 안정을 위한 통합절차에 대한 지침을 제시하고자 한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.105-110
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• 2015

In cognitive radio networks, when the signal-to-noise ratio (SNR) of the link between a primary transmitter and receiver is sufficiently high, the primary transmission does not frequently demand cooperation because direct transmission of the primary communication is usually successful. Therefore, there are few opportunities for a secondary transmitter to cooperate with the primary user system in exchange for an opportunity to share the spectrum. This article proposes a scheme in which the secondary system can deliberately degrade the SNR of the primary transmission, making it so that the primary system needs cooperation from the secondary nodes, and thereby increases opportunities for spectrum sharing.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.4
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• pp.50-56
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• 2001

The present study is an experimental work of the soni $c^ersonic air ejector-diffuser system. The pressure-time dependence in the secondary chamber of this ejector system is measured to investigate the steady operation of the ejector system. Six different primary nozzles of two sonic nozzles, two supersonic nozzles, petal nozzle, and lobed nozzle are employed to drive the ejector system at the conditions of different operating pressure ratios. Static pressures on the ejector-diffuser walls are to analyze the complicated flows occurring inside the system. The volume of the secondary chamber is changed to investigate the effect on the steady operation. the results obtained show that the volume of the secondary chamber does not affect the steady operation of the ejector-diffuser system but the time-dependent pressure in the secondary chamber is a strong function of the volume of the secondary chamber.er.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.241-241
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• 2013

PLS-II 저장링 진공시스템은 2011년 6월 설치 완료 후 2011년 7월부터 2012년 초 까지 1차 시운전을 마쳤다. PLS-II 저장링 진공시스템은 누적 전류 50 Ah 운전 후, 3 GeV, 400 mA 전자빔 운전 시 평균 진공도 $2{\times}10^{-9}$ mbar를 유지도록 설계되어 빔-기체 산란 수명을 20 시간 이상 확보하도록 설계하였다. 지금까지의 간략한 운전 이력과 진공시스템의 성능을 보고하고 최근 방사광 가속기에서 중요하게 취급하는 진공용기(특히, 빔전류 측정 진공용기)의 기계적 안정도, 변위 등과 BPM TE mode noise suppression 등을 보고하고자 한다.

• The KIPS Transactions:PartB
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• v.16B no.2
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• pp.93-100
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• 2009

In this paper, we propose a Difference Image Entropy based gaze direction recognition system. The Difference Image Entropy is computed by histogram levels using the acquired difference image of current image and reference images or average images that have peak positions from $-255{\sim}+255$ to prevent information omission. There are two methods about the Difference Image Entropy based gaze direction. 1) The first method is to compute the Difference Image Entropy between an input image and average images of 45 images in each location of gaze, and to recognize the directions of user's gaze. 2) The second method is to compute the Difference Image Entropy between an input image and each 45 reference images, and to recognize the directions of user's gaze. The reference image is created by average image of 45 images in each location of gaze after receiving images of 4 directions. In order to evaluate the performance of the proposed system, we conduct comparison experiment with PCA based gaze direction system. The directions of recognition left-top, right-top, left-bottom, right-bottom, and we make an experiment on that, as changing the part of recognition about 45 reference images or average image. The experimental result shows that the recognition rate of Difference Image Entropy is 97.00% and PCA is 95.50%, so the recognition rate of Difference Image Entropy based system is 1.50% higher than PCA based system.

• CDE review
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• v.3 no.1
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• pp.45-49
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• 1997

자동차, 조선, 항공 분야 등에서는 3차원 모델러를 이용한 설계작업이 다양하게 이루어지고 있으며 특히 자동차 업계에서는 그 활용도가 대단히 높다. 통상, 완성차 업계에서 작성된 곡면 데이터는 협력업체에서 부품 설계 및 제작에 대단히 중요한 정보가 되기 때문에 이와 같은 곡면정보를 이용하기 위하여 완성차 업체와 동일한 CAD 시스템을 보유하고 있어야 한다. 그러나 완성차 업체에서 사용하고 있는 3차원 모델러(CATIA, Pro/Engineer, 등)는 사용하기가 쉽지 않을 뿐만 아니라 대단히 고가의 장비여서 이를 중소 협력업체에서 구축한다는 것은 현실적으로 매우 어려운 것이 사실이다. 본 고에서는 3차원 모델러 중 자동차 업계에서 가장 많이 쓰이고 있는 CATIA(Dassault사)의 곡면 데이터를 자유로이 응용할 수 있도록 구축한 Jig 설계시스템에 대해 소개하고자 한다.