• Title/Summary/Keyword: High-availability

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Conceptual Simulation Model for Evaluating Availability of Railway System (철도 시스템 가용성능 시뮬레이션 개념 모형)

  • Kim, Jong-Woon;Kim, Hee-Wook;Ohn, Jung-Ghun;Kwon, Tae-Soo;Jeong, Do-Sik
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.1241-1245
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    • 2011
  • High RAM performance and efficient operation plan and maintenance equipment and policies are needed for improving the system availability performance such as punctuality and schedule adherence while reducing life cycle cost. Because railway systems are repairable, complex and have multi-echelon maintenance support structure, it is much complicated to set RAM performance targets and operation and maintenance plan. It is not easy to solve these problem by mathematical method and simulation can be consider for them. This article suggests the conceptual simulation model for analysing availability of railway system which has complex system structure and operation/maintenance environment.

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Trends of High Availability Networking Services (네트워킹 서비스 고가용성 기술동향)

  • Shim, J.C.;Ryu, H.Y.;Yang, S.H.
    • Electronics and Telecommunications Trends
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    • v.30 no.6
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    • pp.79-89
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    • 2015
  • 네트워크 분야의 시장 변화에 신속하게 대응하기 위해 장비 제조 업체들은 표준에 기반을 두어 하드웨어 및 소프트웨어를 개발하고 있다. 이러한 산업계 표준을 제정하는 대표적인 기구로 SCOPE alliance와 Service Availability Forum(SAForum)이 있으며, 이들은 상호 협력 속에 새로운 생태계 구축을 위한 시도를 꾸준히 진행해오고 있다. 본고에서는 먼저 이들 기구의 표준화 동향를 살펴보고, 특히 네트워킹 소프트웨어 분야에서 고가용성 향상을 위한 기술로 SAForum에서 제정하여 배포하고 있는 미들웨어 기술을 소개한다. 그리고 미들웨어에서 제공하는 다양한 서비스 중에서 고가용성 제어의 핵심 서비스인 Availability Management Framework(AMF)와 이의 기반이 되는 다중화 모델을 설명하고, 국외 통신장비에서 채용하고 있는 대표적인 가용성 기술들을 살펴본다.

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Evaluation of Power Performance by Anemometer on WTGS (풍력발전기 너셀에 장착된 풍속계를 이용한 출력성능 평가)

  • Kim, Soo-Sang;Park, Se-Kwang
    • Journal of Sensor Science and Technology
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    • v.21 no.4
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    • pp.303-310
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    • 2012
  • We carried out the power performance evaluation for 1.5 MW${\times}$2 by using anemometer installed on WTGS(Wind Turbine Generator System) in the wind farm at Shi-hwa bang-a-mu-ri. In this paper, we compared and analyzed the performance of guaranteed output and measured output of WTGS which includes output curve, output coefficient, AEP(Annual Energy Product) and availability, etc.. The power performance of WTGS was optimized in the low wind speed sections(3 m/s ~ 10 m/s) and the measured output was more produced by AEP 109 % and availability 112 % than the guaranteed output. In addition, we could also cut the high cost of testing WTGS performance by using anemometer as a substitute for weather mast.

Cloud System Construction for Availability of University Information System

  • Jang, Hae-Sook;Park, Ki-Hong
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.12
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    • pp.179-186
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    • 2017
  • Managing students' data is a high prioritized duty of the university administration since most of the school affairs are proceed based on that database. Universities have invested in IT assets such as servers, storage, database, and networks. However, continuing investment in IT infrastructure is impossible due to limited budget and rapid changes in the educational environment. As cloud computing diffuse, universities are trying to reduce costs and improve efficiency by increasing server utilization, unlike when physically investing. We designed a hypothetical academic information management system based on cloud computing by utilizing the advanced server virtualization technology. This administrative cloud system allows universities to improve the availability of the system with low cost. The system demonstrates its flexibility of using data resources and immediacy of resumption.

Studies on Availability of Components in Extract of Scutellariae Radix by Boiling water Method (전탕(煎湯)에 의한 황금(黃芩)의 성분(成分) 이행율(移行率)에 관한 연구(硏究) I)

  • Ko, Byoung-Seob;Joo, Hye-Jeong;Ma, Jin-Yeul;Park, Kap-Joo;Ahn, Sang-Woo
    • Korean Journal of Oriental Medicine
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    • v.2 no.1
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    • pp.496-505
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    • 1996
  • In order to improve the qualities of boiling extract the availability of standard compounds was investigated in extract of Scutellariae Radix. The standard compounds used baicalin(1), baicalein(2), and wogonin(3). The availabilities were analyzed by thin layer chromatography (TLC) and high performance liquid chromatography(HPLC) on $C_18$ column. The extract of RS-4(W/V=10g/100m1) showed the highest availabilities as 7.95% of baicalin(1), 1.04% of baicatein(2), and 0.31% of wogonin(3).

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Software Architecture for Implementing the Grid Computing of the High Availability Solution through Load Balancing (고가용성 솔루션 구축을 위한 그리드 측면에서의 소프트웨어 아키텍처를 통한 로드밸랜싱 구현)

  • Lee, Byoung-Yup;Park, Jun-Ho;Yoo, Jae-Soo
    • The Journal of the Korea Contents Association
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    • v.11 no.3
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    • pp.26-35
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    • 2011
  • In these days, internet environment are very quickly development as well on-line service have been using a online for the mission critical business around the world. As the amount of information to be processed by computers has recently been increased there has been cluster computing systems developed by connecting workstations server using high speed networks for high availability. but cluster computing technology are limited for a lot of IT resources. So, grid computing is an expanded technology of distributed computing technology to use low-cost and high-performance computing power in various fields. Although the purpose of Grid computing focuses on large-scale resource sharing, innovative applications, and in some case, high-performance orientation, it has been used as conventional distributed computing environment like clustered computer until now because grid middleware does not have common sharable information system. In order to use grid computing environment efficiently which consists of various grid middleware, it is necessary to have application-independent information system which can share information description and services, and expand them easily. This paper proposed new database architecture and load balancing for high availability through Grid technology.

Assessment of Dietary Iron Availability and Analysis of Dietary Factors Affecting Hematological Indices in Iron Deficiency Anemic Female High School Students (철결핍성 빈혈 여고생의 철분이용률 평가 및 철분영양지표에 영향을 미치는 영양요인 분석)

  • 안홍석
    • Journal of Nutrition and Health
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    • v.32 no.7
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    • pp.787-792
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    • 1999
  • The purpose of this study was to estimate the iron availability and to analyze dietary factors which influence hematological indices of 130 female adolescents with iron deficiency anemia. Intakes of iron and other nutrients were estimated using a self-administrated questionnaire combined with the 24-hour recall mehtod and iron availability was calculated by Monsen's method. Mean daily intakes of calorie, protein and vitamin C were 1631.0kcal(77.7% of RDA), 54.7g(84.2% of RDA) and 45.7mg(83.0% of RDA), respectively. In terms of iron, mean daily intake was 8.7mg(48.3% of RDA) and heme iron intake was 3.0mg which correspond to 34% of total iron intake. The amount of total absorbable iron was 1.5mg and the estimated bioavailability of dietary iron was 17.2%. In summary, intake of several nutrients for most of the subjects were under RDA. Dietary factors affecting hematological indices were analyzed by stepwise multiple regression. Intake of vitamin C was a major determinant of Hb level, while both intake of enhancing factor and iron availability were major determinants of serum ferritin level. In conclusion proper nutritional education and guidance for iron deficiency anemic female adoalescent needs to be developed and to improve their iron storage should be increased intakes of enhancing factors, female adoalescents.

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Development of a Quality Check Algorithm for the WISE Pulsed Doppler Wind Lidar (WISE 펄스 도플러 윈드라이다 품질관리 알고리즘 개발)

  • Park, Moon-Soo;Choi, Min-Hyeok
    • Atmosphere
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    • v.26 no.3
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    • pp.461-471
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    • 2016
  • A quality check algorithm for the Weather Information Service Engine pulsed Doppler wind lidar is developed from a view point of spatial and temporal consistencies of observed wind speed. Threshold values for quality check are determined by statistical analysis on the standard deviation of 3-component of wind speed obtained by a wind lidar, and the vertical gradient of horizontal wind speed obtained by a radiosonde system. The algorithm includes carrier-to-noise ratio (CNR) check, data availability check, and vertical gradient of horizontal wind speed check. That is, data sets whose CNR is less than -29 dB, data availability is less than 90%, or vertical gradient of horizontal wind speed is less than $-0.028s^{-1}$ or larger than $0.032s^{-1}$ are classified as 'doubtful', and flagged. The developed quality check algorithm is applied to data obtained at Bucheon station for the period from 1 to 30 September 2015. It is found that the number of 'doubtful' data shows maxima around 2000 m high, but the ratio of 'doubtful' to height-total data increases with increasing height due to atmospheric boundary height, cloud, or rainfall, etc. It is also found that the quality check by data availability is more effective than those by carrier to noise ratio or vertical gradient of horizontal wind speed to remove an erroneous noise data.

On the Surface Moisture Availability Parameters to Estimate the Surface Evaporation (증발량 추정을 위한 지표면 가용 수분 계수)

  • 황병화;황수진
    • Journal of Environmental Science International
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    • v.4 no.5
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    • pp.427-435
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    • 1995
  • In order to discuss the differences among the SMP(Surface Moisture Availability Parameter), by previous researchers on the basis of their own theoretical and empirical background, we assessed the SMP according to the soil types and volumetric soil water contents. The results are as follows. There are differences among all the five SMAPs. There's a tendency that the larger grain size, the higher value of parameters. And they divided into two groups for their value: one group has parameters with exponential function and the other with cosine and linear function. The maximum difference between the two groups appears when the volumetric soil water contents are 0.07m3m-3 for sand, 0.l1m3m-3 for loam, 0.12 for clay, and 0.13m3m-3 for silt loam. So, these differences must be considered when we estimate the surface evaporation rate. From field data, the paddy field soil around Junam reservoir is classified as a silt has high wetness, 0.56. So, the parameter obtained from the field measurement is much higher than that of Clapp and Hornberger(1978)'s Table. This study treated the SMP for a certain point of time in winter season. But if we measured the soil water contents continuously, we could obtain better time-dependent parameter. Key words : SMAP(Surface Moisture Availability Parameter), Paddy field, Volumetric soil water content, Evaporation, Capillary potential.

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A Case Study on the MRI Profitability of a General Hospital (한 종합병원의 MRI 채산성 사례 연구)

  • Kang, Chang-Yeol;Song, Sung-Ho;Lim, Kyeong-Tae
    • The Korean Journal of Health Service Management
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    • v.4 no.1
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    • pp.145-156
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    • 2010
  • The purpose of this study is one of high price medical equipment wished to grasp propriety factor about the MRI introduction, analyzing payability through cost accounting into compensation. It was investigated from January 1 to December 31, 2007 about the MRI of a General Hospital. Expectation availability was 23.2 cases, but actual availability did achievement more than 196.1% with 45.5 items. It is estimated that there are a lot of occurrence cases because great reasons that actual availability increases more than expectation availability is excellent resolving power than a CT, and is device that prefer to reason back that radiation damage is less in person body. The followings show the main results of this study. 1. The MRI was construed in order of cost accounting, wave and personnel expenses 45.4%, administrative expenses 53.0%, and material costs 1.6%. 2. According to CVP (Cost-volume-profit) analysis, BEP (Break Even Point) profit is 173,931,428 won for 11 months, and break even usage number of items are 37.5 cases, and separation usage number of items were confirmed by 1.4 cases. Therefore, was construed that can achieve BEP within 11 months though usage number of items keeps 1.4 items day to create the MRI's hospital operation profit. 3. Estimated limit profitability appears high by 96.7%, exceed fixed charges even if when is non-benefit and when it is benefit consider variable, is judged that the MRI's addition induction helps in hospital management enhancing earning rates.