• Title/Summary/Keyword: 관로 안정화

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Feasibility Study of Multi-regional Transmission Main Stabilization for Sustainable Water Supply (수돗물 공급 안정화를 위한 광역상수도 관로 안정화 타당성 연구)

  • Lee, Jae Bum;Yi, Choong Sung;Jung, Kwan Sue
    • Journal of Korean Society of Water and Wastewater
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    • v.27 no.3
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    • pp.395-404
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    • 2013
  • The risk of pipe-bursting in multi-regional transmission mains consisting of 89 % of singled pipeline is so high that pipeline stabilization project is required such as renewal and replacement, pipe paralleling, emergency ties. Pipeline stabilization projects could be postponed at the step of initial decision-making because effect of this project is intangible benefit like activation of economic, improvement of welfare related to water. This study is to suggest quantified economical feasibility model for intangible benefit presumption to solve above problem. Cost reduction of emergency water supply, leakage, burst restore and energy efficiency improvement was altered and applied. As a result of economic analysis taking into account estimated benefit and cost under discount rate 5.5 %, service life 40 years, sufficient economic feasibility analyzed with B/C 2.45, NPV 317,700 million won, IRR 9.09 %.

Change of Cardiovascular Function of Industrial Workers Apply to Lumbar Stabilization Exercise according to the Floor Type (지면의 상태에 따른 요부안정화운동 적용 시 산업체 근로자의 심혈관기능 변화)

  • Kim, Chan-Kyu;Chae, Yun-Won;Kim, Myung-Hoon;Lee, Jeong-Hun;Ko, Dae-Sik;Jung, Dae-In
    • The Journal of the Korea Contents Association
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    • v.9 no.7
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    • pp.225-232
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    • 2009
  • This study conducted the following experiment to examine effects of cardiovascular function on lumbar stabilization exercise(LSE) in floor or swiss ball. This experiment was conducted to compare heart rate, systolic blood pressure, diastolic blood pressure and peripheral vascular oxygen saturation effects by lumbar stabilization exercise in floor or swiss ball with 18 normal adult and it divided 9 subjects. experiment group (1) is applying LSE on floor group and (2) is applying LSE on swiss ball group. Heart rate was measured by portable heart rate manometer, blood pressure was measured by hemodynamometer, and peripheral vascular oxygen concentration was measured using a computerized NURYTEC measuring apparatus analysis. These result lead us to the conclusion that systolic blood pressure and peripheral vascular oxygen concentration were influenced by LSE. but there was not differential effect between each groups. These results suggest that LSE has the capability to improve heart rate, blood pressure, peripheral vascular oxygen concentration. Consequently, LSE would be lead to increment of cardiovascular function.

증기발생기 전열관 sleeve레이저 보수용접을 위한 자동 확관장치의 구성

  • 김민석;백성훈;정진만;박승규;김철중
    • Proceedings of the Korean Nuclear Society Conference
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    • 1997.05b
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    • pp.561-565
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    • 1997
  • 증기발생기 전열관 보수를 위하여 sleeve pipe를 삽입하여 레이저 용접을 하는 과정에서 전열관과 sleeve pipe 의 간격을 최소한으로 줄여 용접 품질을 높이고, 균등하게 하기 위하여 sleeve pipe에 대하여 확관이 수행된다. 확관은 sleeve pipe의 상단부와 하단부에 각각 수행되는데 정확한 확관규격을 유지하기 위하여 컴퓨터로 확관압력의 미분치를 비교분석하여 압력펌프를 제어하였다. 압력신호의 변화가 크고 안정되지 못하여 전후신호와 비교분석하여 안정화시킨 후 미분치를 추출하여 제어함으로써 전열관의 확관이 0.02mm 이내가 되도록 하여 전열관의 과도한 확관을 방지하였다.

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Assessing the willingness to pay for avoiding water pipeline accidents by repairing pipelines (갱생사업의 관로사고 피해저감에 대한 지불의사액 추정)

  • Choi, Hyo Yeon;Ryu, Mun Hyun;Choi, Han Joo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2017.05a
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    • pp.126-126
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    • 2017
  • 수도권 광역상수도는 관로 매설 이후 30년 이상 경과하여 수도관로 사고 발생빈도가 증가하고 있다. 이에 노후관로를 갱생하여 사고예방과 용수공급 안정성 강화를 도모할 필요가 있으며, 이러한 사업의 수행 여부에 대한 판단을 위해서는 사업 시행으로 발생하는 경제적 편익에 대한 정량적 정보가 필요하다. 노후관로 갱생사업의 경제적 편익은 크게 관로사고 피해저감 편익과 복구비용 절감편익으로 구분되는데 후자는 공학적 접근을 통해 비교적 쉽게 평가할 수 있는 반면에, 전자는 평가가 어렵다. 이에 본 논문에서는 조건부 가치측정법이라는 경제학적 기법을 적용하여 관로사고 피해저감 편익을 추정하고자 한다. 수도권 광역상수도 갱생사업의 수혜지역 주민 600 가구를 무작위로 추출하여 수도권 광역상수도 갱생사업이 시행되지 않을 경우 관로사고가 발생할 수 있음을 설명한 후, 관로사고를 막기 위한 지불의사액을 조사하였다. 분석결과 관로사고 피해 회피를 위한 가구평균 지불의사액은 톤당 약 41.7원이었다. 이 정보는 노후관로 갱생사업에 대한 의사 결정시 활용할 수 있다.

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Microscopic Study of Decomposition-Inhibition in Stabilized $ClO_2$ Gas in Kidney of Rat with Passage of Time (시간경과에 따른 안정화 이산화염소(Stabilized $ClO_2$)의 콩팥조직 부패억제에 대한 현미경적 연구)

  • Hwang, Kyu-Sung;Choi, Ki-Ju;Paik, Doo-Jin;Lim, Do-Seon
    • Applied Microscopy
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    • v.38 no.3
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    • pp.259-264
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    • 2008
  • The stabilized $ClO_2$ gas has been used for many years by the food industry as a strong oxidizing and sanitizing agent that has broad and high biocidal effectiveness. Therefore, "stabilized $ClO_2$" gas may be used in fields of disinfectant and sterilization. But, there have been few studies on the decomposition-inhibition effect of stabilized $ClO_2$ gas with passage of time. The main purpose of this study was to examine the decomposition-inhibition effect of stabilized $ClO_2$ gas and the morphological change of kidney by measuring of the light and electron microscope. Sprague-Dawley (SD) rats weighting from 230 gm to 250 gm were used as experimental animals. Under ether anesthesia, the right kidney of rat was obtained. Put each sample in $37^{\circ}C$ and humidity $80{\pm}5%$ incubator, we obtained each sample after 0 day, 1 day, 2 days, 3 days, 4 days and 5 days. We proceeded the observation of light and electron microscope. The results obtained in this study reveal that stabilized $ClO_2$ gas is an effective decomposition inhibitor until 2 days that was conducted at $37^{\circ}C$ and humidity $80{\pm}5%$ conditions.

Effect of Electron Correlation on Radical Stabilization Energies (라디칼 안정화에너지에 미치는 전자 Correlation 효과)

  • Ikchoon Lee;Bon-Su Lee;Chang Hyun Song
    • Journal of the Korean Chemical Society
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    • v.27 no.5
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    • pp.320-329
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    • 1983
  • Effect of alkyl substitution on stabilization of $\alpha$-aminomethyl radicals, $CH_2NH_2$, has been investigated using MINDO/3-RHF method. Stabilization energies obtained from total energy of radicals indicated that the alkyl substitution decreases radical stability, which is in agreement with the ab initio MO results of Goddard but is contrary to trend shown by experimental results. It was also found that conformations of radicals were different from ab initio results. When, however, approximate account of electron correlation was made in the estimation of stabilization energies of radicals by assuming a proportionality between coulomb correlation and one center exchange integral, the order of radical stability was shown to agree to that found experimentally. It was therefore concluded that the main cause of discrepancy between theoretical and experimental order of stability of alkylsubstituted radicals is the failure of accounting electron correlation energies in the theoretical estimation.

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