• 제목/요약/키워드: Field Observational Study

검색결과 115건 처리시간 0.026초

Angles-Only Initial Orbit Determination of Low Earth Orbit (LEO) Satellites Using Real Observational Data

  • Hwang, Hyewon;Park, Sang-Young;Lee, Eunji
    • Journal of Astronomy and Space Sciences
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    • 제36권3호
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    • pp.187-197
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    • 2019
  • The Optical Wide-field patroL-Network (OWL-Net) is a Korean optical space surveillance system used to track and monitor objects in space. In this study, the characteristics of four Initial Orbit Determination (IOD) methods were analyzed using artificial observational data from Low Earth Orbit satellites, and an appropriate IOD method was selected for use as the initial value of Precise Orbit Determination using OWL-Net data. Various simulations were performed according to the properties of observational data, such as noise level and observational time interval, to confirm the characteristics of the IOD methods. The IOD results produced via the OWL-Net observational data were then compared with Two Line Elements data to verify the accuracy of each IOD method. This paper, thus, suggests the best method for IOD, according to the properties of angles-only data, for use even when the ephemeris of a satellite is unknown.

Seismic vulnerability assessment of buildings based on damage data after a near field earthquake (7 September 1999 Athens - Greece)

  • Eleftheriadou, Anastasia K.;Karabinis, Athanasios I.
    • Earthquakes and Structures
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    • 제3권2호
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    • pp.117-140
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    • 2012
  • The proposed research includes a comprehensive study on the seismic vulnerability assessment of typical building types, representative of the structural materials, the seismic codes and the construction techniques of Southern Europe. A damage database is created after the elaboration of the results of the observational data obtained from post-earthquake surveys carried out in the area struck by the September 7, 1999 Athens earthquake, a near field seismic event in an extended urban region. The observational database comprises 180.945 buildings which developed damage of varying degree, type and extent. The dataset is elaborated in order to gather useful information about the structural parameters influence on the seismic vulnerability and their correlation to the type and degree of building damages in near field earthquakes. The damage calibration of the observational data was based on label - damage provided by Earthquake Planning and Protection Organization (EPPO) in Greece and referred to the qualitative characterization for the recording of damage in post-earthquake surveys. Important conclusions are drawn on the parameters that influence the seismic response based on the wide homogeneous database which adds to the reliability of the collected information and reduces the scatter on the produced results.

도심지 굴착에서 지반의 거동예측과 계측관리 (Ground Behavior Analysis of Excavation near High Rising Building and Field Observation Control)

  • 기홍석;박근수;오재화;이문수
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 1998년도 학술발표회 발표논문집
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    • pp.401-406
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    • 1998
  • This study aimed at the technique for the construction control in braced excavation works. Selecting a case of Kwangju subway works, field observational values were compared with prediction using Plaxis's. Maximum observational values relevant to both horizontal and vertical proved satisfactory in that they were within the criteria. Numerical results by used Plaxis were overestimated greater than observational values, which meant the prediction were safe tendency. .It must be emphasized that displacement measurement for neighboring important structures should be carried out in order to take countermeasure charge for construction methods, in case that the risk or failure was previewed.

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영동 대설 사례를 대상으로 한 WRF Simulation의 Nudging 방법에 따른 민감도 연구 (A Sensitivity Study of WRF Model Simulations to Nudging Methods for A Yeongdong Heavy Snowfall Event)

  • 최지원;이재규
    • 대기
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    • 제25권1호
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    • pp.99-115
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    • 2015
  • To investigate the influences of the observational nudging and the analysis nudging on the WRF simulation for the heavy snowfall event in Yeongdong area on 26 February 2012, the sensitivity experiments in relation to nudging effects were conducted. We initially set the magnitude of nudging coefficient of $6.0{\times}10^{-4}s^{-1}$ to apply to the analysis nudging experiments and observational experiments. To select the optimized options for the observational nudging, the radius influence experiment was carried out with radii ranging from 10 to 25 km at 5 km intervals. Among the observational nudging experiments, the experiment, which was conducted with the option of the radius influence of 15 km and that of the nudging coefficient of $6.0{\times}10^{-4}s^{-1}$ (ONG exp.), showed a best result. As giving the nudging effect only directly on D1 and D2 brought about a better result for the analysis nudging, we set the analysis nudging experiment as above (ANG exp.). We compared and analyzed the results from the control experiment, ONG experiment, and ANG experiment to reveal nudging effects. It was found that the control experiment brought about a result that it overestimated its precipitation in comparison with the observation and failed to properly simulate the time zone of rainfall concentration. When either of the two nudging (observational and analysis nudging) was applied to the data assimilation, it brought about a better result than the control experiment. Especially the observational nudging led to a meaningful result for the wind field, while the analysis nudging had the best result for the precipitation distribution among the experiments.

3D 파노라마 가상 현실 기술을 이용한 지질 답사 학습 자료의 개발과 적용 (Development and Application of Virtual Geological Field Trip Program using 3D Panorama Virtual Reality Technique)

  • 김희수
    • 한국지구과학회지
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    • 제35권3호
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    • pp.180-191
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    • 2014
  • 본 연구에서는 전라북도 부안군 채석강 지역에 대한 3D파노라마 가상 현실 지질 답사 투어 학습자료를 개발하였다. 개발된 프로그램은 $360^{\circ}{\times}180^{\circ}$ 파노라마로서 관측 지점의 모든 면을 볼 수 있고, 확대, 축소, 화면 돌리기 등의 상호작용이 가능하다. 이 프로그램의 교육적 효과를 얻기 위해 컴파스 활용하기, 지층의 경사 등을 측정하기 위한 이동 가능한 각도기 제공, 관찰 지점의 표본에 대한 3D 관찰하기 등을 제공하였다. 또 주요 관찰 포인트에는 확대된 사진, 팝업창, 전문가 설명 등으로 학습을 도왔다. 이 프로그램의 교육적 효과를 알아보기 위하여 중학교 과학 영재반 학생 35명에게 적용해본 결과 약 85% 이상의 긍정적인 반응을 보여주었다. 따라서 이 프로그램은 중학교 과학과 지질학 수업 시 간접적 상황학습이 될 수 있고, 시간문제, 비용문제, 안전문제 등을 줄일 수 있는 하나의 보충적인 지질 답사 방법이 될 것이다.

섬유근통에 대한 국내 임상 연구 동향 및 중재 방향 (Korean Domestic Trends of Clinical Research and Direction of Intervention for Fibromyalgia)

  • 이정한;금지혜;우현준;이창훈;정종혁;이명수
    • 척추신경추나의학회지
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    • 제15권2호
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    • pp.43-54
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    • 2020
  • Objectives The purpose of this review was to analyze the trend of clinical research related to fibromyalgia and to suggest the direction of intervention Methods We reviewed the clinical research by searching seven Korean web databases and classified the studies by the year of publication, academic field, and study design. Results A total of 75 clinical studies were selected. Except for 2002, more than one study was annually published; however, the number was below 10. In the academic field, there were 34 in the medical field, 21 in the Korean medicine field, and 15 in the nursing science field. By study design, there were 62 observational studies, mostly case reports and case-control studies. There were 13 experimental studies, including non-random control studies and one group pre and post-test design studies. Conclusions Fibromyalgia-related clinical research requires a greater number of studies, and a study design with a high level of evidence should be conducted along with various observational and intervention studies. Additionally, multidisciplinary and integrated intervention plans and research are needed.

비보호좌회전에서의 간격수락 행태모형 개발 (Development of Gap Acceptance Models for Permitted Left Turn Intersections)

  • 이청원;이동민;황순천
    • 한국도로학회논문집
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    • 제18권5호
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    • pp.95-103
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    • 2016
  • PURPOSES : Permitted left turn is a turning maneuver in which a vehicle turns left using a gap between oncoming vehicles, called gap acceptance, and it enables for more efficient traffic operation at intersections. In Korea, the permitted left turn has not been a common maneuver at signalized or un-signalized intersections. However, many experts and the Police Agency tried to apply this effective turning maneuver at intersections in Korea since 2010. Though the investigation of gap acceptance is significantly important in understanding a driver's behavior at intersections, there have not been many studies about this topic, specifically a study to develop probability models of gap acceptance behavior. METHODS : In this study, the probability model of gap acceptance behavior for a permitted left turn was developed based on observational field studies. To develop the model, seven variables were analyzed including gap, waiting time, traffic volume, conflict-flow vehicle type, left-turning vehicle type, the number of lane, and time. RESULTS : In the final model, gap and left-turning vehicle type were found to be significant influencing factors. CONCLUSIONS : Through this model development, it was concluded that as the gap size increased, the probability of gap acceptance was higher. Moreover, when a left-turning vehicle was a passenger car, the probability of gap acceptance was higher than compared to large size buses or freight cars.

야외 지질 학습장의 퇴적암과 지질 구조에 관한 초등학생들의 관찰 및 가설 분석 (An Analysis of Observations and Hypotheses of Elementary School Students on Sedimentary Rocks and Geological Structures in Field Courses)

  • 서동욱
    • 한국지구과학회지
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    • 제25권7호
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    • pp.586-594
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    • 2004
  • 이 연구는 야외 지질 학습에 대한 관찰 및 가설을 분석하여 야외 지질 학습에 대한 방향을 찾아보고자 하는 기초 연구의 성격을 가진 질적 연구이다. 야외 지질 학습장에서의 학습 내용을 분석함으로써 관찰, 가설의 관련성을 연구하는데 그 목적이 있다. 이 연구를 통해 얻은 결론은 다음과 같다. 첫째, 지질학습의 특성상 초등학생들은 대부분 시각에 의존하여 관찰하며, 퇴적 지층 지역의 관찰은 암석 관찰에, 가설은 지질 구조에 관한 가설을 많이 생성하였다. 둘째, 관찰 분류들로 분석 한 결과, 이 연구에서 추가한 관찰 행동 영역인 비교 관찰의 빈도가 높게 나타났으며, 2가지 관찰 행동의 조합으로 나타난 사례의 빈도도 높았다. 셋째, 관찰 유형을 기준으로 보면 해석적 관찰 및 비교 관찰과 조합된 과학적 설명 가설의 비율이 가장 높게 나타났다. 이것은 암석과 지질 구조를 해석하고 다른 것과 비교하여 자신의 사고를 합리화 하려는 경향으로 볼 수 있다. 가설 유형을 기준으로 분석한 결과 과학적 설명 가설이 가장 많은 비율을 차지하였고, 사전 지식이나 선개념을 적용하여 해석하고 설명하려는 경향이 있다고 판단된다.

미술영재 판별을 위한 관찰 평가 도구에 관한 초·중학교 미술교사들의 인식 조사 연구 (The Visual Art Teachers' Perceptions on the Observational Evaluation System for the Artistic Giftedness in Elementary and Middle School)

  • 강병직;맹희주
    • 영재교육연구
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    • 제26권1호
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    • pp.123-140
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    • 2016
  • 본 연구는 초 중학교에 재직 중인 미술교사들을 대상으로 미술영재의 관찰 평가 도구 개발에 대한 인식을 조사한 연구이다. 조사 결과, 현장의 초 중학교 미술교사들 사이에는 교사의 관찰 평가에 의한 선발 방식이 미술영재성을 보다 적절히 평가할 수 있는 중요하고도 유용한 방안으로서 폭넓게 인식되고 있으며, 미술 분야에서 교사 관찰 평가 도구를 활용할 경우 평소 선호하는 학생에게 더 유리할 수 있다는 점을 우려하고 있는 것으로 나타났다. 또한 교사 관찰 평가 도구와 관련된 현장 교사의 연수가 매우 미진하지만, 미술영재의 행동특성 체크리스트와 미술영재의 과제수행 과정의 특성을 평가할 수 있는 미술영재 과제수행 검사를 가장 중요한 도구로 인식하고 있다. 따라서 미술영재성 판별의 타당도를 제고하고 평가의 신뢰성을 제고하기 위해서는 미술 분야에서도 미술영재의 행동특성과 미술영재의 과제수행 과정을 평가할 수 있는 객관적 검사 도구가 개발되어야 할 것이다.

Sweet BV 시술이 Rat의 중추신경계에 미치는 영향 - 기능관찰 종합평가를 이용하여- (Effects of Sweet Bee Venom on the Central Nervous System in Rats -using the Functional Observational Battery-)

  • 안중철;권기록
    • 대한약침학회지
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    • 제14권3호
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    • pp.19-45
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    • 2011
  • Objectives: This study was performed to analyse the effects of Sweet Bee Venom(Sweet BV-pure melittin, the major component of honey bee venom) on the central nervous system in rats. Methods: All experiments were conducted at Biotoxtech Company, a non-clinical studies authorized institution, under the regulations of Good Laboratory Practice (GLP). Male rats of 5 weeks old were chosen for this study and after confirming condition of rats was stable, Sweet BV was administered in thigh muscle of rats. And checked the effects of Sweet BV on the central nervous system using the functional observational battery (FOB), which is a neuro-toxicity screening assay composed of 30 descriptive, scalar, binary, and continuous endpoints. And home cage observations, home cage removal and handling, open field activity, sensorimotor reflex test/physiological measurements were conducted. Results: 1. In the home cage observation, there was not observed any abnormal signs in rats. 2. In the observation of open field activity, the reduction of number of unit areas crossed and rearing count was observed caused by Sweet BV treatment. 3. In the observation of handling reactivity, there was not observed any abnormal signs in rats. 4. In the observation of sensorimotor reflex tests/physiological measurements, there was not observed any neurotoxic signs in rats. 5. In the measurement of rectal temperature, treatment of Sweet BV did not showed great influences in the body temperature of rats. Conclusions: Above findings suggest that Sweet BV is relatively safe treatment in the central nervous system. But in the using of over dose, Sweet BV may the cause of local pain and disturbance of movement. Further studies on the subject should be conducted to yield more concrete evidences.