• 제목/요약/키워드: Pointing

검색결과 668건 처리시간 0.036초

저궤도 위성 자세제어 센서 RLG 피에조 구동기 설계 (The Design of Path Length Controller in Ring Laser Gyroscope for Attitude Control in the LEO satellite)

  • 김의찬;이흥호
    • 전기학회논문지
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    • 제57권9호
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    • pp.1584-1588
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    • 2008
  • The Ring Laser Gyroscope makes use of the Sagnac effect within a resonant ring cavity of a He-Ne laser and has more accuracy than the other gyros. The Low Earth Orbit satellite for observatory use require the high accuracy Gyro to control and determine the altitude because of the need of payload pointing accuracy. In this paper, The theory of the Path Length Control is explained. The electrical design of Path Length Controller is described. The Design for Path Length Controller is composed of the demodulator, integrator, phase shifter, high voltage amplifier. We apply the circuit to 28cm square ring laser gyro and get the test results.

참조 카운팅 스마트 포인터의 속도 보완 방법 연구 (A Study on Method to Complement Speed of the Reference Counting Smart Pointer)

  • 박경준;서민석;박현주
    • 한국정보통신학회논문지
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    • 제17권4호
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    • pp.878-884
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    • 2013
  • 최근의 C++ 개발자들은 개발 시 메모리 관리에 장점을 지닌 참조 카운팅 방식의 스마트 포인터를 많이 활용한다. 그러나 스마트 포인터는 빠른 응답성을 요구하는 시스템에서는 일반 포인터에 비해 효율적이지 못한 동작 방식 때문에 문제가 생길 수 있다. 본 논문에서는 이러한 점을 보완하여 참조 카운팅 방식 스마트 포인터가 가리키는 객체에 대한 삭제 작업을 수행 시 삭제 작업을 위한 쓰레드를 생성하여 성능을 개선하는 방법을 제안 하였다. 또한 이를 일반화 시켜서 모든 자료 형에서 동작시키기 편리한 방법을 제안하였다.

한국 SI산업에서 CBD사업의 장애 요인과 발전 가능성: 한은 금융망 시스템 구축 사례 (The Roadblocks and Chances of Component-Based Development Business in Korea SI Industry: a Case of BOK-WIRE System)

  • 김강석
    • 한국IT서비스학회지
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    • 제3권2호
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    • pp.105-118
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    • 2004
  • Since Component-Based Development, or CBD, struck Korea SI industry a heavy blow several years ago, many major SI companies in Korea have implemented the CBD practices in real world, leveraging supports from the government and academic world. The result, however, falls short of their expectations. The major reason is that they have mainly focused on CBD processes and technical issues around it, although it is necessary as well to deal with other non-technical issues in order to make business values from CBD. This paper begins with reminding us what CBD tries to achieve indeed in terms of software development processes, then recognizes what we have achieved so far introducing a recent CBD project case, BOK-WIRE system. Thereafter, it reveals the chances that SI companies must take in order to make their CBD efforts succeed, pointing out what are the roadblocks really.

정상 임무운용 상태에서 다목적실용위성 2호 탑재체에 대한 태양 입사각 분석 (SUN INCIDENCE ANGLE ANALYSIS OF KOMPSTAT-2 PAYLOAD DURING NORMAL MISSION OPERATIONS)

  • 김응현;용기력;이상률
    • Journal of Astronomy and Space Sciences
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    • 제17권2호
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    • pp.309-316
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    • 2000
  • KOMPSAT-2 will carry MSC(Multi-Spectral Camera) which provides 1m resolution panchromatic and 4m resolution multi-spectral images at the altitude of 685km sun-synchronous mission orbit. The mission operation of KOMSPAT-2 is to provide the earth observation using MSC with nadir pointing. KOMPSAT-2 will also have the capability of roll/pitch tilt maneuver using reaction wheel of satellite as required. In order to protect MSC from thermal distortion as well as direct sunlight, MSC shall be operated within the constraint of sun incidence angle. It is expected that the sunlight will not violate the constraint of sun incidence angle for normal mission operations without roll/pitch maneuver. However, during roll/pitch tilt operations, optical module of MSC may be damaged by the sunlight. This study analyzed sun incidence angle of payload using KOMPSAT-2 AOCS (Attitude and Orbit Control Subsystem) Design and Performance Analysis Soft ware for KOMPSAT-2 normal mission operations.

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최근 분임조 문집의 경향과 이에 따른 문제점 개선방안에 관한 연구 -전국분임조대회 수상기업 중심으로 (Research on the recent tendency of quality circle papers and improvement plans)

  • 양희중
    • 품질경영학회지
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    • 제44권4호
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    • pp.845-853
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    • 2016
  • Purpose: This research is to find the general and somewhat prevailing problems in quality circle papers. Many quality circles try to benchmark awarded papers even though they may have common problems. By pointing out popular problems in papers, many quality circles hopefully could be guided to the right direction in working out improvement actions. Methods: Many papers awarded in national quality circle conferences are deeply analyzed to figure out common problems. 69 recent papers are analyzed step by step and the most important and frequently occurring problems in each step are indicated. Results: Many prevailing problems are found in each step of QC stories. Especially finding themes, Grasping status quo, Cause analysis, Setting targets, Development of and Implementing counter attacks are the most common areas that have problems. Conclusion: Some problems are already too popular to be recognized as problems. In this paper those problems are logically criticized and thereby right directions for future quality circle activities are proposed.

외팔보 구조물의 진동감쇠를 위한 동흡진기의 실험적 연구 (An Experimental study on the Vibration absorber for vibration attenuation of cantilever beam structure)

  • 곽동기;배재성;황재혁;김헌수
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2011년도 춘계학술대회 논문집
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    • pp.627-632
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    • 2011
  • This study was carried out vibration attenuation of vibration absorber attached to the cantilever beam structure. Modern tank guns are stabilized to allow fire on the move while traversing uneven terrain. However, as the length of the barrel is extended, to meet required muzzle exit velocities, the terrain induced vibrations lead to increased muzzle pointing errors. Thus, reducing these vibrations should lead to increased accuracy. The vibration absorber includes a compliant energy storage device, such as a spring, and a mass secured to the energy storage device. In this study, it accomplished a research in about gun barrel vibration attenuation using tuned mass damper. The barrel was hung from a bungee cord for free - free condition. It accomplished a vibration experiment for verified attenuation efficiency.

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건설현장의 안전보건 주요 현안과 개선 방안 (Main Problems and Suggestions on Occupational Safety and Hygiene in Construction Sites)

  • 심규범
    • 한국산업보건학회지
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    • 제22권4호
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    • pp.329-336
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    • 2012
  • Objectives: The aim of this study is to analyze main problems on occupational safety and hygiene in construction sites and to suggest some improvement methods. In order to decrease industrial accidents, I emphasize the approach paradigm shifts according to characteristics of construction workers. Methods: Pointing out the irrationality of current institutions by comparing bad outcomes of occupational safety and hygiene in construction industry and characteristics of construction workers. Results: In order to decrease industrial accidents, we need some approach paradigm shifts; the supply method of industrial safety and health fundamentals on the construction industry level, the accident rate calculation by using the actual construction workforce instead of an estimation, institutionalizing the prevention efforts themselves for industrial accidents, securing enough production costs for the precondition of occupational safety and hygiene in construction sites. Conclusions: I ascertain the need of the approach paradigm shifts for decreasing industrial accidents in the construction industry.

Field Emission of Carbon Nanotubes

  • Ihm, Ji-Soon;Han, Seung-Wu
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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    • pp.235-238
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    • 2000
  • We have performed ab initio pseudopotential electronic structure calculations for various edge geometries of the (n,n) singlewall nanotube with on without applied fields. Among the systems studied, the one with the zigzag edge exposed by a slant out is found to be the most favorable for the emission due to the existence of unpaired dangling bond states around the Fermi level. The next favorable geometry is the capped nanotube where ${\pi}-bonding$ states localized at the cap and pointing to We tube axis direction occur at the Fermi level. A scaling rule of the induced field linean in the aspect ratio of the tube is also obtained.

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이온주입식 자기버블 전산기 기억소자에서의 자기버블 전파실패에 관한 연구 (A Study On The Propagation Failure Modes of Ion Implanted Magnetic Bubble Computer Memory Devices)

  • 조순철
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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    • pp.339-342
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    • 1988
  • Typical magnetic bubble propagation failure modes of ion implanted magnetic bubble computer memory devices were observed and their failure mechanisms were analize. The skidding failure mode is due to the pushing of a strong repulsive charged wall. If this pushing is stronger than the edge affinity of the bubble in the cusp, the bubble moves out of the cusp when it is supposed to stay there. The stripeout failure modes across the adjacent track or along the track can be explained by considering the relative strength of the charged wall and the edge affinity encountered by both ends of the stripe. The skipping of the first cusp of a track is believed to be due to the whipping motion of the charged wall. The bubble moves directly to the second cusp via the long charged wall pointing to the second cusp skipping the first cusp.

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다채널 이미지의 회전각 추정 (Rotation Angle Estimation of Multichannel Images)

  • 이봉규;양요한
    • 대한전기학회논문지:시스템및제어부문D
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    • 제51권6호
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    • pp.267-271
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    • 2002
  • The Hotelling transform is based on statistical properties of an image. The principal uses of this transform are in data compression. The basic concept of the Hotelling transform is that the choice of basis vectors pointing the direction of maximum variance of the data. This property can be used for rotation normalization. Many objects of interest in pattern recognition applications can be easily standardized by performing a rotation normalization that aligns the coordinate axes with the axes of maximum variance of the pixels in the object. However, this transform can not be used to rotation normalization of color images directly. In this paper, we propose a new method for rotation normalization of color images based on the Hotelling transform. The Hotelling transform is performed to calculate basis vectors of each channel. Then the summation of vectors of all channels are processed. Rotation normalization is performed using the result of summation of vectors. Experimental results showed the proposed method can be used for rotation normalization of color images effectively.