• Title/Summary/Keyword: GROUND STATUS

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A Study on the Drinking Water Quality for Primary Lunch School in Seoul (서울지역 급식 국민학교의 음용수 수질에 관한 연구)

  • 이원묘;이용옥;방형애
    • Journal of Environmental Health Sciences
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    • v.21 no.1
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    • pp.7-20
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    • 1995
  • The aims of this study are to enhance the students' knowledge of the drinking water and its reliability by investigating drinking water situation on the drinking water. The results are as following 1. Status and drinking behavior about school drinking water (1) 97.82% of the schools are using the tap water as the resource of drinking water. (2) 46 schools are in possession of water tank and 18 schools of them are using the water tank as the resource of drinking water. The clearing and sanitization of the tank are carried out once in a year with hypochloronatrium by the low-level officials. (3) 51.28% of the schools are providing the students with drinking water and 75% of them with boiled water. The drinking water supply managers are low-level officials, nurse teachers, and dietitian. 2. Analysis of the drinking water quality (1) Most of the drinking water provided by the school are tap water 35.8%, barely tea 5.85%, filtered water 6.3%, ground water 1.1% and all turned out to be suitable for drinking. (2) The drinking water carried from home turned out to be unsuitable for drinking except pH criterion, especially the test of APC(Aerobic Plate Count) and Coliform group showed worse degree. These results were caused by the hygiene problem and maltreatment in water container.

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Best Use of the Measured Earthquake Data (지진관측자료의 효과적인 활용에 관한 고찰)

  • 연관희;박동희;김성주;최원학;장천중
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.09a
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    • pp.36-43
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    • 2001
  • In Korea, we are absolutely short of earthquake data in good quality from moderate and large earthquakes, which are needed fur the study of strong ground motion characteristics. This means that the best use of the available data is needed far the time being. In this respect, several methods are suggested in this paper, which can be applied in the process of data selection and analysis. First, it is shown that the calibration status of seismic stations can be easily checked by comparing the spectra from accelerometer and velocity sensor both of which are located at the same location. Secondly, it is recommended that S/N ratio in the frequency domain should be checked before discarding the data by only look of the data in time domain. Thirdly, the saturated earthquake data caused by ground motion level exceeding the detection limit of a seismograph are considered to see if such data can be used for spectrum analysis by performing numerical simulation. The result reveals that the saturated data can still be used within the dominant frequency range according to the levels of saturation. Finally, a technique to minimize the window effect that distorts the low frequency spectrum is suggested. This technique involves detrending in displacement domain once the displacement data are obtained by integration of low frequency components of the original data in time domain. Especially, the low frequency component can be separated by using discrete wavelet transform among many alternatives. All of these methods mentioned above may increase the available earthquake data and frequency range.

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Possibility and Countermeasures of Subsidence according to Mining Method and Current Status in the Operation Mines (가행광산 채광방식과 현황에 따른 지반침하 가능성과 대책)

  • Jang, Myoung Hwan;Lee, Sang-eun
    • Tunnel and Underground Space
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    • v.27 no.6
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    • pp.366-376
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    • 2017
  • In this paper, we investigated the subsidence possibility and countermeasures according to the current mining method through investigation of the subsidence condition in operation mine. Most of the metal mine were broken, investigating to subsidence pattern of the Sink-hole. Coal mines are becoming more and more deep, investigating to Trough type subsidence patterns in existing mining areas. History of nonmetallic mines have not been developed for over 30 years, but large and small ground deformation problems have been investigated. Mining also has ground subsidence functionality due to time dependence by relying more heavily on empirical methods than technical methods. Therefore, it is necessary to carry out the various researches on systematic development method and prevention of subsidence of nonmetallic mines.

Estimation of the Potato Growth Information Using Multi-Spectral Image Sensor (멀티 스펙트럴 이미지 센서를 이용한 감자의 생육정보 예측)

  • Kang, Tae-Hwann;Noguchi, Noboru
    • Journal of Biosystems Engineering
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    • v.36 no.3
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    • pp.180-186
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    • 2011
  • The objective of this research was to establish the estimation method of growth information on potato using Multi-Spectral Image Sensor (MSIS) and Global Positioning System (GPS). And growth estimation map for determining a prescription map over the entire field was generated. To determine the growth model, 10 ground-truth points of areas of $4m^2$ each were selected and investigated. The growth information included stem number, crop height and SPAD value. In addition, images information involving the ground-truth points were also taken by an unmanned helicopter, and reflectance value of Green, Red, and NIR bands were calculated with image processing. Then, growth status of potato was modeled by multi-regression analysis using these reflectance value of Green, Red, and NIR. As a result, potato growth information could be detected by analyzing Green, Red, and NIR images. Stem number, crop height and SPAD value could be estimated with $R^2$ values of 0.600, 0.657 and 0.747 respectively. The generated GIS map would describe variability of the potato growth in a whole field.

Main Control System of Propulsion System Test Complex(PSTC) for KSLV-II (한국형발사체 추진기관시스템 시험설비(PSTC) 통합제어시스템)

  • Kim, Dongki;Lee, Jungho;Cho, Kiejoo;Shim, Juyoung
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.1205-1211
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    • 2017
  • The Propulsion System Test Complex(PSTC) was constructed for the verification test of each stage's propulsion system of KSLV-II. Main Control System(MCS) is the system to operate the onboard equipment and the ground equipment of the PSTC simultaneously. This paper describes the critical design, the development status, and test results of Main Control System. The MCS will be used for the interface connection between ground control systems and onboard equipment. Test sequence and operation process of the Work Manager will be conducted by MCS.

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Electrical resistivity tomography survey for prediction of anomaly in mechanized tunneling

  • Lee, Kang-Hyun;Park, Jin-Ho;Park, Jeongjun;Lee, In-Mo;Lee, Seok-Won
    • Geomechanics and Engineering
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    • v.19 no.1
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    • pp.93-104
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    • 2019
  • Anomalies and/or fractured grounds not detected by the surface geophysical and geological survey performed during design stage may cause significant problems during tunnel excavation. Many studies on prediction methods of the ground condition ahead of the tunnel face have been conducted and applied in tunneling construction sites, such as tunnel seismic profiling and probe drilling. However, most such applications have focused on the drill and blast tunneling method. Few studies have been conducted for mechanized tunneling because of the limitation in the available space to perform prediction tests. This study aims to predict the ground condition ahead of the tunnel face in TBM tunneling by using an electrical resistivity tomography survey. It compared the characteristics of each electrode array and performed an investigation on in-situ tunnel boring machine TBM construction site environments. Numerical simulations for each electrode array were performed, to determine the proper electrode array to predict anomalies ahead of the tunnel face. The results showed that the modified dipole-dipole array is, compared to other arrays, the best for predicting the location and condition of an anomaly. As the borehole becomes longer, the measured data increase accordingly. Therefore, longer boreholes allow a more accurate prediction of the location and status of anomalies and complex grounds.

A Study on Ground Control System Design by User Classification to Increase Drone Platform Usability (드론 플랫폼 활용성 증대를 위한 사용자 맞춤형 지상 제어 시스템 설계 연구)

  • Ukjae Ryu;Yanghoon Kim
    • Journal of Platform Technology
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    • v.10 no.4
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    • pp.56-61
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    • 2022
  • Various convergence technologies discovered through the 4th industrial revolution are permeating the industry. Drones are being used in industries such as construction, transportation, and national defense based on convergence technology. Quart-copter drone control is being used in a wide range of fields from the visual field of operation with the naked eye to the remote field of view using GCS. If we classify those who operate industrial drones, there are general pilots who directly use drones, instructors who train drone pilots, and mechanics who check the status of drones and use them for a long time. Depending on the shape of the screen of the drone GCS, a user's quick response or key data can be acquired. Accordingly, in this study, GUI characteristics were analyzed for the mission planner GCS and a screen composition method according to the user was proposed.

Distribution status survey of livestock Products Sold via Online Websites (온라인 축산물 유통 실태 조사)

  • Kim, Ji Yeon;Seo, Eun Ju;Koh, Ba Ra Da;Seo, Doo Ri;Jung, Bo Ram;Seo, Mi Hee;Lim, Jin Teak;Kim, Eun Sun;Kim, Yong Hwan
    • Korean Journal of Veterinary Service
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    • v.39 no.1
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    • pp.13-20
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    • 2016
  • This study is aimed to find out distribution status of online-market livestock products by purchasing and examining 120 cases of livestock products (seasoned meat: 17, 33 cases of packaged meat, 23 cases of ground meat, 19 cases of ham, 11 cases of sausage, 4 cases of bacon, 1 case of meat processing, 8 cases of Meat extract processed, and 4 cased of Dry storage of meat) at 17 On-line markets from April to August. 2015. We checked the weight of them first, and carried out ingredients test for each of processed meats. And we performed gene screening test on the products which were labelled 'Hanwoo' to investigate that the products were made of Korean native cattle. we also carried out test of identifying domestic animal species on ham, sausage and ground processed products. After weighing all products, we could know that all of them were delivered more than labelled weight or in allowable error. The result values of test which measured level of preservatives, Nitrite, Volatile Basic Nitrite (VBN), and tar Color by the type of processed meat products were in permissible range or not detected. Also, 17 beefs inspected Korean native cattle gene test were confirmed that they were made by real korean native cattle. But 2 cases of Ham, sausage, and ground processed products had difference between label and goods. In this study, we could make a decision that livestock products, distributed in On-line markets, were safe and expect to make higher degrees of hygiene for livestock products seller. Futhermore, we hoped result of this study could be used by basic data for progressive national policy decisions.

Current Limiting Characteristics of a Flux-Lock Type SFCL for a Single-Line-to-Ground Fault

  • Oh, Geum-Kon;Jun, Hyung-Seok;Lee, Na-Young;Choi, Hyo-Sang;Nam, Gueng-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.9
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    • pp.70-77
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    • 2006
  • We have fabricated an integrated three-phase flux-lock type SFCL, which consists of an YBCO($YB_a2Cu_3O_7$) thin film and a flux-lock reactor wound around an iron core of each phase. In order to apply the SFCL in a real power system, fault analyses for the three-phase system are essential. The short-circuit currents were effectively limited by adjusting the numbers of winding of each secondary coil and their winding directions. The flux flow generated in the iron core cancelled out under the normal operation due to the parallel connection between primary and secondary windings. However, the flux-lock type SFCL with same iron core was operated just after the fault due to the flux generating in the iron core. To analyze the current limiting characteristics, the additive polarity winding was compared with the subtractive one in the flux lock reactor. Whenever a single line-to-ground fault occurred in any phase, the peak value of the line current of the fault phase in the additive polarity winding increased up to about 12.87 times during the first-half cycle. On the other hand, the peak value in the subtractive polarity winding increased up to about 34.07 times under the same conditions. This is because the current flow between the primary and the secondary windings changed to additive or subtractive status according to the winding direction. We confirmed that the current limiting behavior in the additive polarity winding was more effective for a single-line-to-ground fault

Accuracy of Combined Block Adjustment with GPS-Permanentstation (GPS 연속관측점을 이용한 결합블럭조정의 정확도)

  • 박운용;이재원;신상철
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.17 no.1
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    • pp.21-32
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    • 1999
  • Mapping and precise point determination by photogrammetry have been shown to be an economic solution. But control points are necessary to determine the exterior orientation parameters. Although the number of required control points has been reduced based on extended bundle adjustment and reinforced cross-strip, the ground survey is a significant factor of whole expenses in photogrammetry. The status of GPS-photogrammetry with kinematic DGPS-positioning to overcome this disadvantages, is now steadly progressive since the first possibility has been proved. The completed satellite configuration, powerful receiver function and upgraded software for kinematic DGPS-positioning have extensively improved the accuracy of combined bundle adjustment. So the research for the operational use of GPS-photogrammetry is absolutely necessary. The presented test field was designed for identification of subsidences in a coal mining area, flown with 60% sidelap and cross strips. Just with 6 control points and combined block adjustment instead of the traditionally used 21 horizontal and 81 vertical control points the same ground accuracy has been reached. The accuracy of kinematic GPS-positioning and combined block adjustment was independent upon the distance of the ground reference station. It also has been showed that the special model for the systematic error correction in the combined block adjustment.

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