• 제목/요약/키워드: observing

검색결과 2,943건 처리시간 0.028초

정밀 수준측량을 위한 소규모 지역에서의 GPS 수준성과 분석 (Analysis of GPS Levelling in Small Area for Precise Leveling)

  • 강준묵;임영빈;이은수;선재현
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2004년도 춘계학술발표회논문집
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    • pp.51-55
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    • 2004
  • In this study, the levelling and the GPS levelling were carried out with 6 points in 2km${\times}$2km area and the results were analysed. As a result of this research, we had to observe more than 15 minutes to get the height accuracy of 10mm by single frequency GPS receiver in relative surveying. We could not get more better accuracy than 10mm. we could get the height accuracy of within 10mm from observing only more than 5 minutes by double frequency GPS receiver, and of within about 3mm from observing more than 10 minutes. When the number of fixed points is within 3, the level net adjustment result is very close to the one of direct levelling survey. When the number of fixed points is 3, the less the area of triangle the better the adjustment result, and the case of including measure point has more better accuracy than that of non-including measure point.

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건물-지반 시스템에 관한 진동대실험 (1) : 반무한지반위의 구조물 (Shaking table test on soil-structure interaction system (1) : Superstructure with foundation on half-space soil)

  • Lee Sung-Kyung;Masato Motosaka;Min Kyung-Won
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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    • pp.538-547
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    • 2005
  • This paper presents the shaking table testing method, only using building specimen as an experimental part taking into account the dynamic soil-structure interaction based on the substructure method. The Parmelee's soil stiffness is used as an assumed soil model in here. The proposed methodologies are summarized as: (1) Acceleration feedback method is the one that the shaking table is driven by the motion, corresponding to the acceleration at foundation of the total SSI system. This is found by observing the fed-back accelerations of superstructure and using the interaction force based on the acceleration formulation. (2) Velocity feedback method is the one that the shaking table is driven by the motion, corresponding to the velocity at foundation of the total SSI system. This is found by observing the fed-back accelerations of superstructure and using the interaction force based on the velocity formulation. The applicability of the proposed methodologies to the shaking table test is investigated and experimentally verified in this paper.

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Damage detection of railway bridges using operational vibration data: theory and experimental verifications

  • Azim, Md Riasat;Zhang, Haiyang;Gul, Mustafa
    • Structural Monitoring and Maintenance
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    • 제7권2호
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    • pp.149-166
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    • 2020
  • This paper presents the results of an experimental investigation on a vibration-based damage identification framework for a steel girder type and a truss bridge based on acceleration responses to operational loading. The method relies on sensor clustering-based time-series analysis of the operational acceleration response of the bridge to the passage of a moving vehicle. The results are presented in terms of Damage Features from each sensor, which are obtained by comparing the actual acceleration response from the sensors to the predicted response from the time-series model. The damage in the bridge is detected by observing the change in damage features of the bridge as structural changes occur in the bridge. The relative severity of the damage can also be quantitatively assessed by observing the magnitude of the changes in the damage features. The experimental results show the potential usefulness of the proposed method for future applications on condition assessment of real-life bridge infrastructures.

Photoelectric Observations of the Close Eclipsing Binary System CW Cephei

  • Han, Won-Yong
    • Journal of Astronomy and Space Sciences
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    • 제1권1호
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    • pp.41-53
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    • 1984
  • Photoelectric observations of the close eclipsing binary system CW Cep, which is well known of its apsidal motion, were made on 20 nights during August and November in 1983 using two 61cm reflectors at the Sobaeksan Observing Station of Korean National Astronomical Observatory and I1san Observing Station of Yonsei University Observatory. Standardized new light curves in UBV system are presented with a total of 1,422 individual observations. For the corrections of regional and instrumental differences, same standard stars were observed at the two observatories. Four new times of minimum light were determined with the method of Kwee and van Woerden(1956). With all of the collected times of minima, apsidal motion of this system was checked, but the O-C values calculated by the light elements of Nha(1975) and Soderhjelm (1976) did not coincide well with new times of minima. New light elements which satisfy most times of minima better, and are deduced the apsidal period derived by the new light elements turns out to be 43 years, somewhat longer than those of values previously known.

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Estimation for the Time-t Discounted Price of Multiple Defaultable Zero Coupon Bond

  • Park, Heung-Sik
    • Communications for Statistical Applications and Methods
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    • 제16권3호
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    • pp.487-493
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    • 2009
  • We consider a multiple defaultable zero coupon bond. Assuming defaults occur according to a marked point process, we explain how to estimate the time-t discounted price of zero coupon bond by simulation. For the special case of a given specific random face value, we show that the real probability measure is the risk neutral probability measure. In this case the time-t discounted conditional price can be obtained by observing a single sample path upto the time t in the real world. Furthermore the time-t discounted price can be estimated by observing real situations or by simulation under the real probability measure.

Simultaneous Monitoring of KVN 4 Bands toward Evolved Stars

  • Cho, Se-Hyung
    • 천문학회보
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    • 제39권2호
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    • pp.112.2-112.2
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    • 2014
  • We propose simultaneous monitoring observations of 22 GHz $H_2O$ and 43/86/129 GHz SiO masers toward ~15 evolved stars in order to investigate spatial structure and dynamical effect from SiO to $H_2O$ maser regions including mass-loss process and development of asymmetry in circumstellar envelopes. We also aim at investigating mutual association and difference between SiO and $H_2O$ masers for establishing SiO and $H_2O$ maser models coupled to hydrodynamical model of circumstellar envelope. In addition, the correlation and difference of SiO maser properties among J=1-0, J=2-1, and J=3-2 transition masers are traced according to different type of stars for constraining SiO pumping models. These scientific goals and target sources were determined based on KVN single dish and VLBI feasibility test observations at 4 bands. As a total observing time of every 2 month monitoring, about 90 and 360 hours (in average per year) are required for single dish and VLBI observations, respectively. From the 2014B observing season, these monitoring observations will be derived as one of KVN key science programs.

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중국동남부지역 민가의 주공간 구성과 기능 (Spatial layouts and function of the chinese private house in south-east area)

  • 윤정숙
    • 한국주거학회논문집
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    • 제11권2호
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    • pp.75-83
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    • 2000
  • The purpose of this study was to analyze spatial characteristics of Chinese traditional residents. This study was carried out in order to have a clear understanding of how cultures of neighboring countries influence Korean residential history and to grasp an objective view on characteristics of Korean houses by comparing and contrasting the characteristics of Chinese residents. This survey was conducted by observing, interviewing, taking pictures and analyzing the pictures that were taken on the real spot. Additional data were collected by participating the seminars of Chinese experts on the traditional house. The spatial layouts and function of Chinese traditional house were analyzed by using pictures, sketches and data which were gathered by interviewing and observing. The shape of Chinese traditional unit plans of houses is basically linear. By repeating this linear shape in the south.north and east.west side, various shapes are formed as an outcome. tangwu and woshi, the living space of Chinese traditional house are strictly hierarchical.

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