• Title/Summary/Keyword: light availability

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A Study on the Estimation and Verification of the Availability of the Unmanned Light Railway (무인 경량전철 가용도 산정 및 검증에 관한 연구)

  • Kwon, Sang Don;Song, Bo Young;Lee, Hi Sung
    • Journal of the Korean Society of Safety
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    • v.34 no.1
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    • pp.108-114
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    • 2019
  • Unattended Train operation(UTO) requires higher safety target than other systems, since all train operations are automatic. The system provider to deliver without accident or failure, and the operator to transport passengers without accident by putting all trains supplied, including them, into service. Safety rates without such failures can be represented as indicators of RAMS, among which availability is continuously controllable to achieve the target, with a clear target. Availability is often required by the licensee from the initial stage of the project to demonstrate that the request for proposal (RFP) is usually specified and to maintain separate availability targets at the operational stage. In particular, unlike unmanned operation light rail in complex systems, simple formulas are often presented to facilitate verification at each stage. This paper presents this method of usability calculation in an integrated manner at all levels and analyzes the existing usability values to ensure reliability of the availability formula for integrated use in unmanned light rail systems.

A Study on the application of Computerized Systems Engineering Tool to Support RAMS Activities for Light Rail Transit Project (경량전철사업의 RAMS 활동을 지원하기 위한 SE전산도구 적용에 관한 연구)

  • Lee, Seok Jeong;Choi, Yo Chul
    • Journal of the Korean Society of Systems Engineering
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    • v.10 no.2
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    • pp.33-42
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    • 2014
  • There have been growing demand of Light Rail Transit(LRT) which have a lot of advantages such as construction costs lower than the recent subway, reduction of operational costs, availability of line planning, operation of railway non-beneficiary region, flexible operations of trains, unmanned operation and also have eco-friendly advantages, it is now becoming urban railway systems when environmental issues have been highlighted all over the world. Therefore, RAMS(Reliability, Availability, Maintainability, Safety) Process and activities for effective implementation of light rail transit projects have become a very important element, and also the utilization of computerized tools to perform these more systematically and productively is sought after these days. In this paper, we have presented a plan that can support the RAMS activities by utilizing the function of the computerized SE(Systems Engineering) tool(CORE$^{(R)}$). Through support of the computerized SE tool, it would be possible more clear and efficient railway project execution.

Effect of Soil Respiration on Light Fraction-C and N Availability in Soil Applied with Organic Matter

  • Ko, Byong-Gu;Lee, Chang-Hoon;Kim, Myung-Sook;Kim, Gun-Yeob;Park, Seong-Jin;Yun, Sun-Gang
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.5
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    • pp.510-516
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    • 2016
  • Soil respiration has been recognized as a key factor of the change of organic matter and fertility due to the carbon and nitrogen mineralization. In this study, we evaluated the effect of soil respiration on the light fraction-C and inorganic N content depending on temperature in soil applied with organic matter. Soil respiration was calculated by using total $CO_2$ flux released from soil applied with $2Mg\;ha^{-1}$ of rice straw compost and rye for 8 weeks incubation at 15, 25, $35^{\circ}C$ under incubation test. After incubation test, light fraction and inorganic N content were investigated. Rye application dramatically increased soil respiration with increasing temperature. $Q_{10}$ value of rye application was 1.69, which was higher 27% than that of rice straw compost application. Light-C and $NO_3-N$ contents were negatively correlated to soil respiration. Light-C in rye application more decreased than that in rice straw compost with temperature levels. These results indicate that temperature sensitivity of soil respiration could affect soil organic mater content and N availability in soil due to carbon availability. Also, light fraction would be useful indicator to evaluate decomposition rate of organic matter in soil under a short-term test.

Growth Responses and Ecological Niche of Rare plant Eleutherococcus gracilistylus(W. W. Sm.) S. Y. Hu in Gotjawal, Jeju Island (제주 곶자왈 희귀식물 섬오갈피나무(Eleutherococcus gracilistylus)의 생육반응 및 생태지위)

  • Yoon-Kyung Choi;Eui-Joo Kim;Jung-Min Lee;Ji-Won Park;Yoon-Seo Kim;Kyeong-Mi Cho;Se-Hee Kim;Gyu-Ri Kim;Ju-Seon Lee;Young-Han You
    • Journal of Wetlands Research
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    • v.25 no.3
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    • pp.196-204
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    • 2023
  • Eleutherococcus gracilistylus is a designated rare plant by the Korea Forest Service, a deciduous broad leaf shrub native to the Gotjawal region, Jejudo. This study aimed to analyze the growth responses of E. gracilistylus to three environment factors such as light, moisture, and organic matter, and measure its ecological niche breadth. Based on these results, an attempt was made to identify suitable environmental conditions. E. gracilistylus exhibited increased above-ground length, leaf area, and plant leaf weight under intermediate conditions of light availability(L3, 50% of natural light), rather than very high or very low light conditions. Moisture availability and organic matter availability showed variations in growth responses in terms of leaf count and plant leaf weight. Under moisture availability, growth was favorable under or below intermediate conditions (M3, 240ml), while under organic matter availability, growth response was better above intermediate conditions (N3, 12%). Ecological niche breadth showed in the light factor(0.951), the moisture factor(0.977), and the organic matter content one(0.964). These results indicate that the preferred habitat of E. gracilistylus is somewhat shady, slightly dry, and has a lot of nutrients, and that the environmental factor that has the greatest impact on growth is the amount of light, which is considered to be a priority consideration for habitat management in its native area.

A Daylighting Design Indicator for Korean Dementia Nursing Homes Based on the Therapeutic Effects of Light - Focusing on maximizing daylight availability, optimizing therapeutic views, and minimizing glare (빛에 의한 치료적 효과 기반의 한국형 치매요양시설의 자연채광 계획지표 개발 - 주광 가용성 최대화, 치료적 조망 최적화 및 현휘 최소화 지표 중심으로)

  • Jee, Soo In
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.29 no.1
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    • pp.29-42
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    • 2023
  • Purpose: This study aimed to develop a daylighting design indicator for Korean dementia nursing homes based on the therapeutic effects of light, focusing on the serious aging index facing Korea and the importance of natural light that occupies the most important position in the therapeutic environments for the elderly with dementia. Methods: A wide range of literature-oriented research methods were mobilized to develop the daylighting design indicator of Korean dementia nursing homes. Results: The daylighting design indicator of Korean dementia nursing homes was derived from three perspectives: maximizing daylight availability, optimizing therapeutic view, and minimizing glare. In addition, eighteen basic indicators were derived within seven indicator items in the range of building layout, windows, glazing, shading devices, spaces, interior finishings, and daylight factor. Implications: The daylighting design indicator of Korean dementia nursing homes revealed in this study will contribute to realizing Korean dementia nursing homes as a therapeutic environment for the elderly with dementia.

Soil nitrogen availability in a thinned Larix leptolepis plantation using ion exchange resin bags (이온교환수지봉지를 이용한 일본잎갈나무 간벌지의 질소 유효도 측정)

  • Son, Yo-Whan;Kim, Hyun-Seop
    • Korean Journal of Environmental Agriculture
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    • v.19 no.2
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    • pp.188-190
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    • 2000
  • We explored changes in soil nitrogen (N) availability in a thinned (control, light, moderate, and heavy thinning) Larix leptolepis plantation determined by using ion exchange resin bags. Nitrogen availability varied among measurement periods, however, total available N (ammonium plus nitrate) concentrations did not change significantly in the 1 year since thinning. We found higher N availability in summer and fall than in winter.

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Daylighting Design Factors for Korean Dementia Nursing Homes Based on the Therapeutic Effects of Light (빛에 의한 치료적 효과 기반의 한국형 치매요양시설의 자연채광 계획 요소에 관한 고찰)

  • Jee, Soo In
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.28 no.4
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    • pp.71-87
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    • 2022
  • Purpose: This study examines the daylighting design factors of Korean dementia nursing homes, in order to realize a therapeutic environment based on the therapeutic effect of light in the rapidly aging trend with an huge increase in the population of dementia in Korea. Methods: Through literature reviews, this study aims to theoretically examine the therapeutic light environment for the elderly with dementia, derive daylighting design factors of Korean dementia nursing homes, and analyze their detailed design factors. Results: The result of this study can be summarized into two points. The first one is that the daylighting design factors reflected in dementia nursing homes are derived into six factors: building layout, windows, glazing, shading devices, spaces, and interior finishings that determine the availability of daylight. The second one is that the detailed daylighting design factors are shown as primary and secondary detailed design factors, and the main values to be considered when applying these factors into dementia nursing homes are analyzed as maximizing daylight availability, optimization of the possibility of therapeutic view, and anti-glare. Implications: The daylighting design factors will contribute to maximizing the availability of daylight, optimizing the possibility of view, and minimizing the glare in the living spaces of dementia nursing homes in Korea.

Information Needs and Instrument Availability for Accident Management : Application to YGN 3&4

  • Kim, Jaewhan;Park, Rae-Jun;Suh, Kune-Yull
    • Nuclear Engineering and Technology
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    • v.28 no.6
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    • pp.551-562
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    • 1996
  • This paper introduces the five-step methodology for identifying information needs and assessing instrument availability during the course of severe accidents in nuclear power plants. The methodology is applied to the Yonggwang (YGN) 3&4 to shed light on accident management. It constructs three safety objective trees to prevent the reactor vessel failure, to prevent the containment failure, and to mitigate the fission product release from the containment. The study assesses information needs and instrument availability under severe conditions for preventing the reactor vessel failure of YGN 3&4, and recommends additional instrument that m8y prove to be of vital importance in managing the accident.

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Management Process Study to RAMS Application of Light Rail Transit System (경량전철 시스템의 RAMS 적용을 위한 관리 프로세스 연구)

  • Cha, Gi-Ho;Park, Jin-Jae;Lee, Jae-Hyoung
    • Proceedings of the KSR Conference
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    • 2011.05a
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    • pp.226-238
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    • 2011
  • RAMS (Reliability, Availability, Maintainability, Safety) study has received far less rigorous analysis in the system performance and integration level, and RCM (Reliability Centered Maintenance) research has been studying to improve the maintenance efficiency in the operational steps based on collected data of real operational cases. This paper analyzes the basic concepts based on KS X ISO/IEC 15288 system life-cycle process in the whole system for the light rail transit construction, and the research suggests an approach to the management process of the applicable main tasks. The paper "Management Process Study to RAMS Application of Light Rail Transit System" introduces Airport Rail cases and guidelines by using RAMS which is the major role in the system engineering technical process of ISO/IEC 15288 (International Organization for Standardization/International Electrotechnical Commission 15288) to apply RAMS in domestic light rail transit efficiently, the aim of this study is to broaden of understanding RAMS.

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