• 제목/요약/키워드: Altitude determination

검색결과 58건 처리시간 0.028초

Mie 산란 레이저 레이다 시스템을 위한 에어로졸과 구름의 판별 알고리즘 개발 (Development of algorithm for determination of cloud and aerosol in Mie scattering Laser Radar System)

  • 김신자;이영우;박찬봉
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2012년도 춘계학술대회
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    • pp.568-570
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    • 2012
  • 레이저 레이다를 이용한 에어로솔과 구름의 동시 측정 시에 두 물질을 구분하는 알고리즘을 개발 하였다. 본 방법은 구름과 에어로졸의 후방산란 신호의 고도별 경사 변화의 차이를 이용하는 방법이다. 본 알고리즘의 결과로써 나오는 파라메터는 구름의 운고, 운저, 그리고 경계층의 고도이다.

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Gyroless Yaw Angle Compassing of Earth-Pointing Spacecraft Using Magnetic Sensor

  • Lee, Seon-Ho;Ahn, Hyo-Sung;Rhee, Seung-Wu
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2004년도 ICCAS
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    • pp.2055-2058
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    • 2004
  • This paper formulates a yaw angle determination algorithm for earth-point satellite. The algorithm based on vector observation, is implemented with the limited vector measurements. The proposed algorithm doesn't require gyro measurement data but magnetic sensor measurement data. In order to confirm the usefulness of the proposed method, we investigate the simulated telemetry data of the KOMPSAT-2, a satellite that is scheduled to be launched into a 685km altitude sun synchronous circular orbit in 2005.

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비행시험을 통한 엔진의 혼합기레버 위치 설정에 관한 연구 (A Study on Determination for Mixture Lever's Position by Flight Test)

  • 김진곤;김칠영;이정모;이정훈
    • 한국항공운항학회지
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    • 제3권1호
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    • pp.37-47
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    • 1995
  • It is very important to determine the performance and operating envelope of engine for aircraft's flight. The basic performance is provided by manufacturer, but installed engine's operating envelop is only determined by flight test. First, this study was measured cylinder head temperature(CHT), exhaust gas temperature(EGT) and oil temperature. At pre-determined altitude and power rate, these temperatures were measured by change of mixture ratio and mixture ratio condition for economic operation and max. power were found. And secondly, with the measured temperatures, possible positions of mixture lever were determined by flight test for stable flight Chang-91 and Lycoming IO-360-A series four cylinders engine with 200 hp was used for this study.

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최적 충돌각 제어법칙에 관한 연구 (A Study of Optimal Impact Angle Control Laws)

  • 송택렬;신상진
    • 한국군사과학기술학회지
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    • 제1권1호
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    • pp.211-218
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    • 1998
  • As a part of trajectory modulation to increase system survivability and terminal effectiveness, impact angle control is required in the terminal phase of tactical missile systems. The missile systems are not allowed to have high altitude to reduce probability of detection by sensors of missile defense systems. In this paper, an analytic form of a time-optimal control law is suggested in the case of constrained missile maneuverability and impact angle under the assumption of a zero-lag autopilot. The control law is obtained by establishing optimal missile-target engagement geometry in the vertical plane. Extension of the law for missiles with autopilot response lags requiring a numerical solution is studied by introducing an iterative algorithm for optimal switching time determination of which the initial switching instants are obtained from the analytic solution. Also suggested is a closed-form impact angle control law derived by an energy-optimal approach. The performances of the proposed guidance laws are evaluated by a series of computer runs.

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군관제사의 직무 수행과 항공교통상황 변인의 영향 연구 (A Study on the Air Traffic Situation Variables which Influence the Job Performance of Military Air Traffic Controllers)

  • 신현삼;장정하;안재모
    • 한국항공운항학회지
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    • 제20권1호
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    • pp.19-25
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    • 2012
  • The air traffic situation variables were emphasized in this research to review the awareness level of job performance of military air traffic controllers in application of air traffic situation variables such as detection of aircraft identification, type of aircraft, position ,speed, altitude, determination of separation between departing and arriving in-trail aircraft, physical airport conditions, adverse weather conditions, NAVAID outage and ATC facilities' operational status. In this respect, This study was conducted under the auspice of ATC facility operating agencies and devoting air force air traffic controller's participation by answering the questionnaires from nine radar approach control facilities and other air traffic control towers.

GEO Satellite Magnetic Momentum Assessment

  • 양정환;김의찬;구자춘;이상곤
    • 천문학회보
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    • 제37권2호
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    • pp.182.2-182.2
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    • 2012
  • If the satellite has the magnetic material or magnetic moment, the satellite is affected by the earth magnetic field by the space environment in Geostational orbit. The aim of this paper is to assess the satellite magnetic momentum which is an input to ADCS(Altitude Determination Control Subsystem) analyses to assess spurious torques. The magnetic momentum at satellite level is due to magnetic momentum generated by each unit which is due to internal currents circulation or to the presence of magnetic components. Also the magnetic momentum at satellite level is due to circulation of the DC supply current from PSR(Power Supply Regulator) to each unit. As introducing the intrinsic contribution of each unit and the magnetic moment based on the current return through the structure, this paper assess the satellite magnetic moment.

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임부의 모유 수유에 대한 태도 유형 분석 (The Pattern of the Attitude of Pregnant Women on Breast Feeding)

  • 정혜경;이미라
    • 모자간호학회지
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    • 제3권2호
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    • pp.126-141
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    • 1993
  • The purpose of this study was to understand the pattern of the pregnant women' attitude on breast feeding. The research had been proceeded as follows ; 1. Delineation of the Q-population the statements of Q-population had been derived from review of the related literature and a open-ended questionnaire filled by nurses, nursing students, general public, and the pregnant women. Total number of concourse collected was 105. 2. Selection of the Q-sample : Among 105 concourse, those which has obscure or overlapped were deleted. 38 concourse were selected finally. 3. Selection of the P-sample : by the convenient sampling technique, 28 subjects had been deter mined among the pregnant women who visited a hospital affiliated with university for the antenatal care, from March to August, 1993. 4. Q-sorting : based on 1 to 9 point scale (forced normal distribution), the selected P-sample rated their operant definition of breast feeding. 5. Determination of Q-type : with Q-sorts, PC-Quanal program identified the three Q-types. 6. Analysis of Q-type : the characteristics of three different attitude had been analyzed based on the typal array, extreme comments, and subject$\sim$s demographic information. The results revealed that there are three different altitudes nth regard to breast feeding : Instinct oriented attitude, Science oriented attitude, and Convenience oriented altitude. Mothers with Instinct oriented attitude and Science oriented altitude are thought to have high possibility to breastfeed their infant willingly, and mothers with Convenience oriented attitude to breast feed under the favorable conditions. These findings can be used as the information giving data for the education to encourage breast feeding.

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An analysis on the Earth geoid surface variation effect for use of the tilt sensor in celestial navigation system

  • Suk, Byong-Suk;Yoon, Jae-Cheol;Lyou, Joon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1867-1870
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    • 2005
  • The celestial navigation is one of alternatives to GPS system and can be used as a backup of GPS. In the celestial navigation system using more than two star trackers, the vehicle's ground position can be solved based on the star trackers' attitude information if the vehicle's local vertical or horizontal angle is given. In order to determine accurate ground position of flight vehicle, the high accurate local vertical angle measurement is one of the most important factors for navigation performance. In this paper, the Earth geophysical deflection was analyzed in the assumption of using the modern electrolyte tilt sensor as a local vertical sensor for celestial navigation system. According to the tilt sensor principle, the sensor measures the tilt angle from gravity direction which depends on the Earth geoid surface at a given position. In order to determine the local vertical angle from tilt sensor measurement, the relationship between the direction of gravity and the direction of the Earth center should be analyzed. Using a precision orbit determination software which includes the JGM-3 Earth geoid model, the direction of the Earth center and the direction of gravity are extracted and analyzed. Appling vector inner product and cross product to the both extracted vectors, the magnitude and phase of deflection angle between the direction of gravity and the direction of the Earth center are achieved successfully. And the result shows that the angle differences vary as a function of latitude and altitude. The maximum 0.094$^{circ}$angle difference occurs at 45$^{circ}$latitude in case of 1000 Km altitude condition.

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Evaluation of Chemical Composition and In vitro Digestibility of Appennine Pasture Plants Using Yak (Bos grunniens) Rumen Fluid or Faecal Extract as Inoculum Source

  • Tufarelli, V.;Cazzato, E.;Ficco, A.;Laudadio, V.
    • Asian-Australasian Journal of Animal Sciences
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    • 제23권12호
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    • pp.1587-1593
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    • 2010
  • Pastures of the Apennines of Central Italy contribute to feed resources of high altitude (above 1,300 m sea level) grazing systems. The objective of this study was to evaluate the effectiveness of faecal extract from the yak (Bos grunnienes) as an alternative microbial inoculum to rumen fluid for estimation of digestibility of several forage species. Forage samples produced at high altitude were tested in this study: four legumes (Lathyrus sativus L., Lotus corniculatus L., Onobrychis viciaefolia L. and Trifolium pratense L.), three forbs (Achillea millefolium L., Potentilla reptans L. and Teucrium flavum L.) and one grass (Brachipodyum pinnatum L.) were incubated with yak rumen fluid or faecal extract. A large variability in chemical composition was observed among the species collected. Rumen liquor and faecal samples were collected from adult healthy yak. The $Daisy^{II}$ incubator was used to evaluate the nutrient digestibility of forages using rumen liquor as control and faecal extract as alternative microbial inoculum sources. Filter bags containing samples of browse species were added to the four digestion vessels along with their respective inoculum and then incubated for 48 h and dry matter (DM), organic matter (OM), crude protein (CP), neutral and detergent fiber (NDF) digestibility was determined. There was a significant relationship between estimates, indicating that faecal liquor has the potential to be used instead of rumen fluid for estimation of in vitro digestibility of plants. It is concluded that the $Daisy^{II}$ incubator results are appropriate for the determination of in vitro digestibility of nutrients using faecal liquor to define the potential for adaptation of yak to new pastures.

SPOT 위성영상(衛星映像)의 외부표정요소(外部標定要素) 결정(決定)에 관한 연구(硏究) (A Study on the Determination of Exterior Orientation of SPOT Imagery)

  • 유복모;조기성;권현
    • 대한토목학회논문집
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    • 제10권4호
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    • pp.77-85
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    • 1990
  • 최근 원격탐측(遠隔探測)의 이용분야가 소축척지도제작(所縮尺地圖製作) 뿐만 아니라 토지(土地), 환경(環境) 및 자원(資源)에 대한 정보해석(情報解析)에까지 확대되고 있다. 특히, SPOT 위성영상(衛星映像)은 높은 해상력(解像力)과 적합한 기선고도비(基線高度比) 및 입체영상(立體映像)의 획득(獲得)이 가능(可能)하며 3차원(次元) 위치결정(位置決定) 등(等)에 필요한 자료(資料)를 제공(提供)한다. 본(本) 연구(硏究)에서는 이와 같이 SPOT 위성영상(衛星映像)을 이용한 3차원(次元) 위치결정(位置決定)에 있어서 중요한 요소(要素)인 외부표정요소결정(外部標定要素決定)에 관한 알고리즘 개발(開發) 및 최적다항식결정(最適多項式決定)에 목적(目的)을 두고 있다. 따라서 본(本) 연구결과(硏究結果) 전처리(前處理) level 1B 사진(寫眞)필름의 위성영상(衛星映像)의 외부표정요소결정(外部標定要素決定) 알고리즘을 제시(提示)하였으며, 외부표정요소(外部標定要素)의 다항식(多項式) 결정(決定)에 있어서는 위성위치요소(衛星位置要素)($X_o$, $Y_o$, $Z_o$)는 1차(次) line함수(函數), 위성자세요소(衛星姿勢要素)(${\kappa}_o$, ${\phi}_o$, ${\omega}_o$)는 2차(次) line 함수식(函數式)으로 표현되는 미지수(未知數)가 15개(個)인 경우가 최적다항식(最適多項式)임을 알 수 있었다.

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