• Proceedings of the KSR Conference
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• 2003.10b
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• pp.117-122
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• 2003

Cheongdam Bridge in Seoul Metropolitan Subway Line No.7 recently constructed has 180 meters (2@90m) of expansion length of structure (distance between fixed points). Track type is all ballasted track and rail expansion joint is installed at every movable point. However, there is no expansion joint at the transition area between ballasted track ,end deck. By this reason, the rail buckling has been occurred every year and there is actually an abnormal behavior in expansion. In this study, based on the modeling of the Cheongdam Bridge, the element of interacting relationship between track and structure which is influential to track displacement in long-span bridge was analyzed and, finally, the methodology to ensure the continuous-welded rail in Cheongdam Bridge was suggested.

• Corrosion Science and Technology
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• v.6 no.6
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• pp.308-310
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• 2007

The owner of underground metallic structures (gas pipeline, oil pipeline, water pipeline, etc) has a burden of responsibility for the corrosion protection in order to prevent big accidents like gas explosion, soil pollution, leakage and so on. So far, Cathodic Protection(CP) technology have been implemented for protection of underground systems. The stray current from DC subway system in Korea has affected the cathodic protection (CP) design of the buried pipelines adjacent to the railroads. In this aspect, KERI has developed a various mitigation method, drainage system through steel bar under the rail, a stray current gathering mesh system, insulation method between yard and main line, distributed ICCP(Impressed Current Cathodic System), High speed response rectifier, restrictive drainage system, Boding ICCP system. We installed the mitigation system at the real field and test of its efficiency in Busan and Seoul, Korea. In this paper, the results of field test, especially, distributed ICCP are described.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.9
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• pp.478-484
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• 2006

The paper presents methods of determining the capacity and installation positions of regenerative inverters installed in DC 1500V electric railway system. We suggested a method that approximates using parameters related to substations where regenerative inverters are installed, railway lines and operating motor cars, and another that calculates using regenerative power obtained from Train performance Simulation (TPS) and Power Flow Simulation (PFS). We carried out TPS and PFS for Seoul Subway Line $5{\sim}8$, calculating regenerative power and determining substations where regenerative inverters would be installed and the optimal capacity and number of inverters to be installed.

• 한국터널공학회:학술대회논문집
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• 2005.04a
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• pp.262-269
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• 2005

The priority order about a rational repair and reinforcement is generally decided by subjective decision of engineer. An appearance investigation by tunnel scanner that is widely used in foreign nation was carried out to decide about a rational repair and reinforcement through systematic and objective analysis in box and NATM tunnel. We have decided on the order of priority of an rational repair and reinforcement through the crack density analysis by span, distance and location with the result of tunnel scanner.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.974-979
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• 2007

From '1994 Gwacheon accident of the Electric Multiple Unit(EMU)' till '2004 Seoul subway 2 lines Guui station accident', the accident is increasing at day and the service demand of the citizen is coming to be various. But it does not deal with technical or operation side demands. There is a possibility of saying that the accident of the EMU or deficit operation is caused by the RCM. The EMU where the efficiency is good though does the time passes and it becomes old anger and does not display that efficiency not only the cause of formation accident does becomes. The breakdown about under occurring before getting up an accident, appropriately shifting the parts is to a maintenance very the pending question fact which is important is a possibility of doing. From there is by an EMU, RCM in reliability base grudge is a tool of confirms an improvement point and the place where it judges. From the research which it sees will present about technical development plan of RCM.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1505-1510
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• 2007

In this paper, the power simulation is used for the prediction of regenerative energy and examination of install location of regenerative inverter for DC railway system. The power simulation was composed to train performance simulation(TPS) and power flow simulation. We performed the power simulation for Seoul subway line 5 and 7, calculation of regenerative energy and examination of substations where regenerative inverter is installed.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.516-518
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• 1995

This paper presents an integrated fault diagnosis expert system for power systems. The proposed system diagnoses various faults occurred in both substations and transmission lines even in the case that substation fault is spreaded over the network. To cope with this problem, A meta-inference method is proposed. This scheme shares same the data structure with the pre-developed intelligent operational aid expert system installed in a practical sub-control center, without modification. This advanced integrated diagnosis system is developed using a low cost personal computer owing to the special modular programming technique. Case studies show a promising possibility of the proposed method.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.79-79
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• 2001

최근 서울의 각 지하철역에서의 라돈농도 측정결과가 각 일간지 및 방송에 보도되면서 서울시의회업무 보고 및 국정감사에서도 중요한 이슈의 하나로 부각되었다. 라돈에 관한 미환경청(USEPA)의 규제치(action level)는 4pCi/L이며 이때의 방사평형인자는 0.5로 되어있다. 서울시에서는 2000년도에 195개소 즉 175개역사와 20개소의 환승통로에 대한 라돈농도에 대한 장단기농도 측정과 1999년도에는 라돈자핵종을 분석하여 이를 바탕으로 라돈방사평형인자를 구한바 있다. (중략)

• Journal of environmental and Sanitary engineering
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• v.17 no.3
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• pp.1-6
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• 2002

This study was carried out to investigate the distribution of Legionella spp and microbe from cooling towers water of Public establishments in Seoul and Gyeonggi-Do. As results of this study, the cooling tower 132 sites were detecting L. pneumophila in order to July(12%) > August (14%) > June, September no-detected. The public establishments were detecting L. pneumophila in order to Department store(27.3%) > Hospital(8.7%) > Office(5.9%) > Big Mart(5.0%) > Hotel, Subway no-detected. The correlation coefficient pH and L.pneumophila showed 0.62(p=0.05), 0.27(p=0.45) in temperature and L.pheumophila, 0.40(p=0.25) in turbidity and L.pneumophila.

• Explosives and Blasting
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• v.8 no.3
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• pp.3-13
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• 1990

First ot of all, under given condition such as bit gage of 36mm Drill bit with right class of jack-leg-experimental test carried out from two face of Bench, firing of each hole brought 90 degree Angle face and them measured length of Burden and charged ammount of powder as following. $ca=\frac{A}{SW}$ A=Activated Area A=nd i=m S=Peripheral length of charged, room Ca=Rock Coeffiecency d: di=Hole diameter When constructed subway of Seoul in 1980 the blasting works increased complaint of ground vibration, in order to prevent the damage to structures. Some empirical equations were made as follows on condition with Jackleg Drill (Bit Gage 36mm) and within 30 meter distance between blasting site and structures. $V=K(D/W)^{-n}$ N=1.60 - 1.78 K= 48 - 138 Project is one of contineous works to above a determination of empirical equation on the cautious blasting vibration with Crawler Drill (70-75mm) in long distance. $V=41(D/\sqrt[3]{W})^{-1.41}$ $30m\le{D}\le{100m}$ $V=124(D/\sqrt[3]{W})^{-1.66}$ $100m\le{D}\le{285m}$.