• Title, Summary, Keyword: RCM

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Application Markov State Model for the RCM of Combustion Turbine Generating Unit (Markov State Model을 이용한 복합화력 발전설비의 최적의 유지보수계획 수립)

  • Lee, Seung-Hyuk;Shin, Jun-Seok;Kim, Jin-O
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.2
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    • pp.248-253
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    • 2007
  • Traditional time based preventive maintenance is used to constant maintenance interval for equipment life. In order to consider economic aspect for time based preventive maintenance, preventive maintenance is scheduled by RCM(Reliability-Centered Maintenance) evaluation. So, Markov state model is utilized considering stochastic state in RCM. In this paper, a Markov state model which can be used for scheduling and optimization of maintenance is presented. The deterioration process of system condition is modeled by a Markov model. In case study, simulation results about RCM are used to the real historical data of combustion turbine generating units in Korean power systems.

Scheduling of Preventive Maintenance for Generating Unit Considering Condition of System (시스템의 상태를 고려한 발전설비의 예방 유지보수 계획 수립)

  • Shin, Jun-Seok;Byeon, Yoong-Tae;Kim, Jin-O;Kim, Hyung-Chul
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.8
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    • pp.1305-1310
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    • 2008
  • Traditional maintenance planning is based on a constant maintenance interval for equipment life. In order to consider economic aspect for time based preventive maintenance, preventive maintenance is desirable to be scheduled by RCM(Reliability-Centered Maintenance) evaluation. The main objective of RCM is to reduce the maintenance cost, by focusing on the most important functions of the system and avoiding or removing maintenance actions that are not strictly necessary. So, Markov state model is utilized considering stochastic state in RCM. In this paper, a Markov state model which can be used for scheduling and optimization of maintenance is presented. The deterioration process of system condition is modeled by the stepwise Markov model in detail. Also, because the system is not continuously monitored, the inspection is considered. In case study, simulation results about RCM will be shown using the real historical data of combustion turbine generating unit in Korean power systems.

복합미생물제제를 이용한 RCM공법의 선박오수 처리장치 적용에 관한 연구

  • Ha, Sin-Yeong;Song, Ji-Gyeong;Kim, In-Su
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.85-86
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    • 2014
  • 본 연구에서는 유입수의 변동이 심하고 전문가가 부재한 환경인 선박에서 발생하는 오수의 효과적인 처리를 위하여 RCM공법을 선박오수처리장치에 적용하는 실험실 규모의 실험을 수행하였다. 질소 인의 고도처리 효율과 선박이라는 특수환경과의 접목성을 검토한 결과 RCM공정에 유효미생물을 주입하는 방법은 선박환경에 적합한 것으로 평가되었다. 또한 RCM공정은 활성슬러지 공정에서 배출되는 슬러지는 배출시키지 않고 슬러지액화분해조(SDC)에서 재분해하여 순환함으로써, 최근 해양투기가 금지됨으로 인해 문제가 되고 있는 슬러지의 발생량을 최소한으로 하여 친환경적인 수처리가 가능하다. 복합미생물제제 주입 후 미생물 관찰결과 고도처리에 유리한 미생물종의 출현을 확인하였으며 이들의 상호기작으로 질소 인의 처리에 도움을 주어 처리효율이 높은것이라 판단된다. 유기물 제거효율 실험결과 $BOD_5$, CODcr T-N, T-P의 처리효율이 각각 96, 97, 78, 81.68 %로 나타나 Membrane이나 Filter없이도 강화되어가는 해양오염기준을 충족시킬 수 있는 공정으로 판단된다.

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Effects of a Rubus coreanus Miquel supplement on plasma antioxidant capacity in healthy Korean men

  • Lee, Ji-Eun;Park, Eun-Kyo;Lee, Jung-Eun;Auh, Joong-Hyuck;Choi, Hyung-Kyoon;Lee, Jae-Hwi;Cho, Soo-Muk;Kim, Jung-Hyun
    • Nutrition Research and Practice
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    • v.5 no.5
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    • pp.429-434
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    • 2011
  • Korean raspberry, Rubus coreanus Miquel (RCM), contains high concentrations of phenolic compounds, which prevent oxidative stress. To determine the effect of RCM on antioxidant capacity in humans, we assessed in vivo lipid oxidation and antioxidant enzyme activities from plasma in 15 healthy men. The subjects ingested 30 g of freeze-dried RCM daily for 4 weeks. Blood was taken at baseline and at the end of the study to determine blood lipid profiles, fasting plasma glucose, liver function, lipid peroxidation, and antioxidant enzyme activities. RCM supplementation had no effect on blood lipid or fasting plasma glucose concentrations but decreased alkaline phosphatase activity. RCM supplementation increased glutathione peroxidase activities (P<0.05) but had no effect on lipid peroxidation. These results suggest that short-term RCM supplementation may offer health benefits by enhancing antioxidant capacity in a healthy population.

A Study on Implementation of RCM for Railway Vehicle (철도차량의 신뢰성기반 유지보수(RCM) 실시 방안)

  • Park, Byoung-Noh;Joo, Hae-Jin;Lee, Chang-Hwan;Lim, Sung-Soo
    • Proceedings of the KSR Conference
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    • pp.1487-1493
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    • 2008
  • Railway vehicle is very important to implement the effective maintenance in proper to prevent any failure during operation period. Many railway authorities are making efforts to maintain the railway vehicle through scientific and systematic procedure. To achieve this, Reliability Centered Maintenance(RCM) is partially applied. The efficiency of RCM has proven and its terminology was familiar with nuclear power, military and chemical plant etc. since the commercial aircraft's industries has introduced the maintenance program based on the target of reliability. The application of RCM on railway vehicle can be utilized with systematic analysis method to select the best effective maintenance period and action to prevent the failures by selecting the equipment affecting the its safety and reliability. This paper is presented that the procedure of adequate and effective maintenance for railway vehicle by comparing among the related standards in example IEC60300-3,11, MIL-STD-2173, and technical documents or papers. In accordance with above result, RCM procedure is proposed to apply effectively for maintenance of railway vehicle. That is, (1) Analysis of data and Calculation of criticality per equipment (2) Selection of equipment to analyze (3) Analysis of failure mode and effect (4) Evaluation of maintenance method and period (5) Optimization of maintenance program through renewal of maintenance method and period.

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Application of Reliability based Inspection for an Effective RCM Approach of Railway System (철도시스템의 효과적 RCM접근을 위한 신뢰성 기반 검사(RBI)적용)

  • Song, Kee-Tae;Kim, Min-Ho;Baek, Young-Gu;Ahn, Eun-Jin;Lee, Key-Seo
    • Proceedings of the KSR Conference
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    • pp.1294-1300
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    • 2008
  • In the current railway industry in Korea, a lot of researches and studies have been progressed to establish RAMS process and construction of RCM system in accordance with international standards. On the point of view of applying the RCM to the railway system, many problems (i.e., reliability of the existing field data, the lack and incorrectness of failure information, etc) are described. To solve these problems, it is need to study and effort the RCM, practically. In this paper, lots of problems and solutions for methods determining the preventive maintenance interval of application of the RCM will be described. To do this, the method using the theory of RBI (Reliability Based Inspection) which is applied to the existing chemical plants and power plants is described. From this study, it is expected that in this situation that the quantitative data is not enough, the results that an analyst quantifies the qualitative factors and/or items will be a good reference that can effectively approach, on the side of determination about each maintenance task and inspection interval.

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Effects Unripe and Ripe Rubus coreanus Miquel on Peritoneal Macrophage Gene Expression Using cDNA Microarray Analysis (미숙과와 성숙과 복분자의 섭취가 복강 Macrophages의 유전자 발현에 미치는 영향)

  • Lee, Jung Eun;Cho, Soo-Muk;Kim, Jin;Kim, Jung-Hyun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.10
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    • pp.1552-1559
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    • 2013
  • Rubus coreanus Miquel (RCM) has been used as one of the Korean traditional medicines for prostate health. In addition, recent studies have reported that RCM reduced chronic inflammatory diseases such as cancer, and rheumatoid arthritis. Therefore, in this study, we investigated the effects of unripe and ripe RCM on inflammationrelated gene expressions in LPS-stimulated mouse peritoneal macrophages. Mice were fed with 2% unripe RCM (U2), 10% unripe RCM (U10), 2% ripe RCM (R2), and 10% ripe RCM (R10) for 8 weeks. Peritoneal macrophages were isolated and stimulated with LPS then proinflammatory mediators (TNF-${\alpha}$, IL-$1{\beta}$, and IL-6), and prostaglandin E2 ($PGE_2$) productions were assessed. Moreover, gene expression profiles were analyzed by cDNA microarray method. Unripe and ripe RCM significantly reduced TNF-${\alpha}$ production but only unripe RCM decreased IL-$1{\beta}$ and IL-6 production. RCM intake significantly reduced inflammatory-related gene expressions such as arachidonate 5-lipoxygenase, interleukin 11, and nitric oxide synthase 2. Furthermore, unripe and ripe RCM significantly decreased ceruloplasmin, tissue plasminogen activator, thrombospondin 1, and vascular endothelial growth factor A expression which modulates symptoms of chronic inflammatory diseases. RCM intake also significantly increased hypoxia inducible factor 3, alpha which is the negative regulators of hypoxia-inducible gene expression. Furthermore, only unripe RCM reduced chemokine (C-C motif) ligand 8, chemokine (C-X-C motif) ligand 14, and phospholipase A2 expression. In this study, we showed that RCM had anti-inflammatory effects by suppression of pro-inflammatory mediator expressions and may reduce chronic inflammatory disease progress through regulation of gene expressions. These findings suggest that RCM might be used as a potential functional material to reduce chronic inflammatory responses.

Outlook of Discharge for Daecheong and Yongdam Dam Watershed Using A1B Climate Change Scenario Based RCM and SWAT Model (A1B기후변화시나리오 기반 RCM과 SWAT모형을 이용한 대청댐 및 용담댐 유역 유출량 전망)

  • Park, Jin-Hyeog;Kwon, Hyun-Han;No, Sun-Hee
    • Journal of Korea Water Resources Association
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    • v.44 no.12
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    • pp.929-940
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    • 2011
  • In this study, the future expected discharges are analyzed for Daecheong and Yongdam Dam Watershed in Geum River watershed using A1B scenario based RCM with 27 km spatial resolutions from Korea Meteorological Agency and SWAT model. The direct use of GCM and RCM data for water resources impact assessment is practically hard because the spatial and temporal scales are different. In this study, the problems of spatial and temporal scales were settled by the spatial and temporal downscaling from watershed scale to weather station scale and from monthly to daily of RCM grid data. To generate the detailed hydrologic scenarios of the watershed scale, the multi-site non-stationary downscaling method was used to examine the fluctuations of rainfall events according to the future climate change with considerations of non-stationary. The similarity between simulation and observation results of inflows and discharges at the Yongdam Dam and Daecheong Dam was respectively 90.1% and 84.3% which shows a good agreement with observed data using SWAT model from 2001 to 2006. The analysis period of climate change was selected for 80 years from 2011 to 2090 and the discharges are increased 6% in periods of 2011~2030. The seasonal patterns of discharges will be different from the present precipitation patterns because the simulated discharge of summer was decreased and the discharge of fall was increased.

Outlook of Discharge for Dam Watershed Using RCM and SWAT Based on A1B Scenario (A1B시나리오 기반 RCM과 SWAT모형을 이용한 댐유역 유출량 전망)

  • Park, Jin-Hyeog;Kwon, Hyun-Han;Chae, Hyo-Sok;No, Sun-Hee
    • Proceedings of the Korea Water Resources Association Conference
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    • pp.354-354
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    • 2011
  • 금강유역에 대한 기후변화 영향을 기후모형 및 수자원영향평가모형을 통하여 정량적으로 분석하기 위하여 한반도 최적 GCM모형으로 기상청에서 제공하는 ECHO-G GCM모형과 역학적 다운스케일링 기법을 이용한 공간해상도 27km의 지역규모의 MM5 RCM모형을 이용하였다. A1B시나리오 기반으로 고해상도 기후변화 시나리오를 작성하여 분석기간을 2015년대(2001-2030), 2045년대(2031-2060), 2075년대(2061-2090)로 구분하여 미래 연평균강수량, 기온 등을 전망하였고, 과거 30년 자료의 100년빈도 강수량과 미래의 100년 빈도강수량의 변동성을 평가하였다. 기본적으로 GCM 및 RCM은 시공간적 스케일의 상이성으로 인해 수자원 영향 평가를 위한 자료로서 직접적인 이용은 현실적으로 곤란하다는 점에서 본 연구에서는 RCM 격자자료를 유역단위에서 강우관측소 지점 단위로 공간적 Downscaling을 실시하였으며 RCM 월자료에 대해서 일단위 자료로 시간적 Downscaling을 수행하여 기후모델로부터 발생하는 시공간적 스케일의 문제점을 극복하였다. 또한 유역단위의 상세수문시나리오를 생산하기 위해서 다지점 비정상성 Downscaling 기법을 활용하여 기존 일강수량 모의기법에서 간과 되었던 비정상성을 고려하여 미래 기후변화에 따른 강수사상의 변동성을 다양한 방법으로 검토하였다. 2001년~2006년 기간동안 SWAT모형을 이용하여 용담댐유역 용담댐 지점의 유입량과 SWAT의 최종방류부의 유량분석값을 비교한 결과 모의치와 실측치가 90.1% 일치하는 것으로 나타났고, 천천수위관측소 지점의 유량을 모형결과와 비교분석 한 결과에서도 91.3% 일치하는 것으로 나타났다. 한편, 대청댐 지점의 유입량과 SWAT의 최종방류부의 유량분석값을 비교한 결과 모의치와 실측치가 84.4% 일치하는 것으로 나타나 금강유역내 용담댐 및 대청댐을 대상으로 유출분석 검토 결과 적용성이 있음을 확인하였다. 기후변화 분석기간은 2011년부터 2090년까지 80년을 대상기간 으로 선정하였으며, 분석결과 2011~2020년 사이 유출량이 18%증가하는 것으로 전망되었다.

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