• Title/Summary/Keyword: Ground monitoring

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Prediction of Settlement Based on Field Monitoring Data under Preloading Improvement with Ramp Loading

  • Woo, Sang-Inn;Yune, Chan-Young;Chung, Choong-Ki
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.436-452
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    • 2008
  • In this study, the settlement prediction method based on field monitoring data under preloading improvement with ramp loading is developed. Settlement behavior can be predicted with field monitored settlement throughout the entire preloading process including ramp loading followed by constant loading. The developed method is verified by comparing its predicted results with results from physical model tests and field monitoring data.

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A Study on Monitoring Efficiency of the Aircraft Noise Monitoring Stations (항공기소음 자동측정국 감시효율에 대한 연구)

  • Son, Jung-Gon;Jeong, Woo-Hong;Hwang, Min-Gee;Gwon, Hyun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.11a
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    • pp.423-428
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    • 2008
  • The monitoring efficiency of the aircraft noise monitoring stations is decided to the reference noise level and the infringement of each monitoring stations. We are calculate the monitoring efficiency of three noise monitoring stations among twelve in the vicinity of Gimpo Int'l Airport. As a result, the monitoring efficiency shows that the noise monitoring stations #3,#5 and #6 are 14.3%, 18.5% and 29.3% respectively, #6 which is underneath the flight track is higher efficiency than another two stations.

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A Study on Site Positions for Monitoring Efficiency Improvements of the Aircraft Noise Monitoring Stations (항공기소음 자동측정국 감시효율 향상을 위한 위치설정에 대한 연구)

  • Son, Jung-Gon;Jeong, Woo-Hong;Hwang, Min-Gee;Gwon, Hyun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.1
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    • pp.50-55
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    • 2009
  • The monitoring efficiency of the aircraft noise monitoring stations is decided to the reference noise level and the infringement of each monitoring stations. We calcurates the monitoring efficiency of three noise monitoring station among twelve in the vicinity of Gimpo Int'l Airport. As a result, the monitoring efficiency shows that the noise monitoring stations No#3, No#5 and No#6 are 14.3%, 18.5% and 29.3% respectively, Among them No#6 staion looks higher efficiency than another two stations because of underneath the flight trackas.

UNDERGROUND WATER PROBLEMS IN DEEP EXCAVATION CONSTRVCTION CONTROL AGAINST BOILING FAILURE IN DEEP EXCAVATION IN SANDY GROUND BY FIELD MONITORING

  • Iwasaki, Yoahinori
    • Proceedings of the Korean Geotechical Society Conference
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    • 1990.10a
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    • pp.97-110
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    • 1990
  • This paper presents a case history of a deep open cut excavation of Nakagawa section for Futuoka Subway construction which adopted observational mettled against boiling failure and completed with success by modifying construction based upon field monitoring. One of the difficult conditions for the excavation was sandy layer with high water pressure which was anticipated boiling failure. The boiling was generally considered as one of the difficult phenomena to work with the observational method because of its unpredictable catastrophic nature. Laboratory experiments showed the existence of the prefailure movements of the ground and the possibility of the application of the observational method against the boiling failure. Construction step was planned to be modified, if necessary, based upon field monitoring and was completed with success.

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Satellite monitoring of large-scale air pollution in East Asia

  • Chung, Y.S.;Park, K.H.;Kim, H.S.;Kim, Y.S.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.786-789
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    • 2003
  • The detection of sandstorms and industrial pollutants has been the emphasis of this study. Data obtained from meteorological satellites, NOAA and GMS, have been used for detailed analysis. MODIS and Landsat images are also used for the application of future KOMPSAT- 2. Verification of satellite observations has been made with air pollution data obtained by ground-level monitors. It was found that satellite measurements agree well with concentrations and variations of air pollutants measured on the ground, and that satellite technique is a very useful device for monitoring large-scale air pollution in East Asia. The quantitative analysis of satellite image data on air pollution is the goal in the future studies.

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Temperature Compensation of Optical FBG Sensors Embedded Tendon for Long-term Monitoring of Tension Force of Ground Anchor (광섬유 센서 내장형 텐던을 이용한 그라운드 앵커의 장기 장력모니터링을 위한 온도보상)

  • Sung, Hyun-Jong;Kim, Young-Sang;Kim, Jae-Min;Park, Gui-Hyun
    • Journal of the Korean Geotechnical Society
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    • v.28 no.5
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    • pp.13-25
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    • 2012
  • Ground anchor method is one of the most popular reinforcing technology for slope in Korea. For the health monitoring of slope which is reinforced by permanent anchor for a long period, monitoring of the tension force of ground anchor is very important. However, since electromechanical sensors such as strain gauge and V/W type load cell are also subject to long-term risk as well as suffering from noise during long distance transmission and immunity to electromagnetic interference (EMI), optical FBG sensors embedded tendon was developed to measure strain of 7-wire strand by embedding FBG sensor into the center king cable of 7-wire strand. This FBG sensors embedded tendon has been successfully applied to measuring the short-term anchor force. But to adopt this tendon to long-term monitoring, temperature compensation of the FBG sensors embedded tendon should be done. In this paper, we described how to compensate the effect in compliance with the change of underground temperature during long-term tension force monitoring of ground anchors by using optical fiber sensors (FBG: Fiber Bragg Grating). The model test was carried out to determine the temperature sensitivity coefficient (${\beta}^{\prime}$) of FBG sensors embedded tendon. The determined temperature sensitivity coefficient ${\beta}^{\prime}=2.0{\times}10^{-5}/^{\circ}C$ was verified by comparing the ground temperatures predicted from the proposed sensor using ${\beta}^{\prime}$ with ground temperatures measured from ground thermometer. Finally, temperature compensations were carried out based on ${\beta}^{\prime}$ value and ground temperature measurement from KMA for the tension force monitoring results of tension type and compression type anchors, which had been installed more than 1 year before at the test site. Temperature compensated tension forces are compared with those measured from conventional load cell during the same measuring time. Test results show that determined temperature sensitivity coefficient (${\beta}^{\prime}$) of FBG sensors embedded tendon is valid and proposed temperature compensation method is also appropriate from the fact that the temperature compensated tension forces are not dependent on the change of ground temperature and are consistent with the tension forces measured from the conventional load cell.

The Marine Environmental Monitoring System in the Yellow Sea (황해의 해양환경 모니터링 시스템)

  • Heo, Seung;Park, Jong-Soo;An, Kyoung-Ho;Lee, Yoon;Choi, Ok-In;Lim, Dong-Hyun;Hwang, Woon-Ki;Lee, Seung-Min;Kim, Pyoung-Joong;Bang, Hyun-Woo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.16 no.3
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    • pp.307-312
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    • 2010
  • The West Sea Fisheries Research Institute of National Fisheries Research and Development Institute which is in charge of research on marine environment, fisheries resources and aquaculture carries out various monitoring projects with an aim of marine ecosystem conservation. The monitoring projects include costal oceanographic observation, serial oceanographic observation, fishing ground monitoring, national marine environmental monitoring, harmful algal bloom monitoring, Korea-China joint monitoring on the Yellow Sea and jellyfish monitoring. The monitoring produces basic data on fishing ground locations of main fishery species to improve fishery productivity. The data are also used to estimate variations in fisheries resources caused by climate change and to set up the policy for creating economic value from fishery, marine environmental conservation and marine leisure activities and conserving/controlling the marine environment for the sustainable production in the fishing ground.

Integrated Analysis of Electrical Resistivity Monitoring and Geotechnical Data for Soft Ground (연약지반에서의 전기비저항 모니터링 및 지반조사 자료의 복합 해석)

  • Ji, Yoonsoo;Oh, Seokhoon
    • Journal of the Korean earth science society
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    • v.36 no.1
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    • pp.16-26
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    • 2015
  • To investigate the applicability of physical prospecting technique in soft ground assessment, the resistivity monitoring data of 6 months are acquired. The Multichannel Analysis Surface Wave (MASW) has been additionally performed to identify the shear wave velocity and strength distribution of soft ground. Moreover, by using the Cone Penetration Test (CPT) and laboratory tests of drilling samples, a relationship with the physical prospect data is checked and the reliability of the physical prospect data is increased. Through these activities, the behavior patterns of soft soil are identified by long term monitoring, and the significant relationship between the shear wave velocity and laboratory tests has been confirmed, both of which can be useful in the surface wave exploration to evaluate the strength of soft ground. Finally, using the geostatistical method, 3-dimensional soil base distribution images are obtained about the combined physical prospecting data with heterogeneous data. Through the studies, the nature of entire area can be determined by long term resistivity monitoring for the soft ground assessment in wider area. It would be more economic and reliable if additional exploring and drilling samples can be analyzed, which can reinforce the assessment.

An In-Process Measurement Technique for Non-contact Monitoring of Surface Roughness and form Accuracy of Ground Surfaces (연삭 가공면의 표면조도와 형상정밀도의 비접촉식 인프로세스 측정기술)

  • Yim, Dong-Yeol
    • Journal of the Korean Society for Precision Engineering
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    • v.4 no.2
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    • pp.36-46
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    • 1987
  • An optical technique using laser for non-contact measurement of surface roughness and form accuracy of ground surfaces is presented. It is found that, when a ground surface is illuminated by a beam of laser light, the roughness height and slope distribution has significant influence on the pattern of reflection and it maintains an unique Gaussian distribution relationship with the surface roughness. The principle idea of the optical measurement system is therefore monitor the radiation, and then calibrate it in process against surface roughness by means of necessary digital data processing. On the other hand, measuring the form accuracy of a ground surface is accomplished by using a triangular method, which is based on observing the movement of an image of a spot of light projected onto the surface. The image is focused, through a series of lenses for magnification, on a photodetector array lf line configur- ation. Then the relative movement of image and consequently the form accuracy of the surface can be obtained through appropriate calibration procedures. Experimental test showed that the optical roughness measurement technique suggested in this work is very efficient for most industrial applications being capable of monitoring the roughness heights ranging 0.1 to 0.6 .$\mu$m CLA values. And form accuracy can be measured in process with a resolution of 10 .$\mu$m.

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Management of coastal and offshore fishing ground using wide-area network of AIS (AIS 광역망을 이용한 연근해 어장관리)

  • Shin, Hyeong-Il;Bae, Mun-Ki;Lee, Dae-Jae;Lee, Yoo-Won
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.42 no.3
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    • pp.179-185
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    • 2006
  • In order to efficiently manage the coastal and offshore fishing ground, the applicability of real-time monitering was also investigated through a wide-area network of automatic identification system(AIS). The experiment of efficiently managing coastal and offshore fishing ground with a wide-area network of AIS required, on the headquarter's screen, a synthetic display of vessel information transmitted from three different distant stations. This experiment tested the applicability of real-time monitoring with the shown display. The maximum range of detection of the first station in Busan was 24 nautical miles while those of the second and third stations in Yeosu and Jeju were 26 and 52 nautical miles, respectively.