• 제목/요약/키워드: Long-term operation

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고속철도 콘크리트 궤도상 토공노반의 장기거동 특성 연구 (Study of the Long-Term Behavior Characteristics of Roadbed on Concrete Track of High-speed Railway)

  • 최찬용;정재현
    • 한국산학기술학회논문지
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    • 제19권4호
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    • pp.8-16
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    • 2018
  • 본 논문의 목적은 고속철도 콘크리트 궤도 및 노반 측정 데이터(노반압력, 진동가속도, 탄성변위 등)를 이용하여 토공노반의 장기거동을 분석하고 궤도 노반의 장기성능을 평가하고자 하는데 있다. 최근 고속철도 궤도 형식이 콘크리트 슬래브로 채택되고 있다. 그러나 콘크리트 궤도는 노반 침하에 취약하다. 자갈궤도의 경우 노반이 침하되어도 유지보수로 원상복구가 용이하다. 반면에 콘크리트 궤도의 경우 노반의 과도한 침하가 발생하면 도상 및 침목에 균열이 지속적으로 발생되고 사용성이 크게 저하된다. 이와 같은 이유로 부분보수만으로 원상복구가 어렵다. 본 논문에서는 운영 중 콘크리트 궤도에 대하여 건설 초부터 매설된 센서의 측정 데이터를 개통 후 약 3년까지 모니터링하여 장기성능평가를 수행하였다. 성능평가 방법은 열차별 궤도 토공노반 및 장기 궤도 노반 성능평가, 장기침하에 따른 궤도 노반 성능 영향 분석 및 장기 침하 영향인자 분석 등이다. 열차별 궤도 노반 성능평가에서는 KTX-산천중련의 노반응답이 가장 컸다. 장기 궤도 노반 성능평가 결과는 측정항목이 기준치이내로 측정되었다. 장기침하에 따른 궤도 노반 성능영향 평가는 TCL처짐은 침하와 깊은 연관이 있는 것으로 분석되었다. 장기침하의 외부영향인자 분석을 통해 함수비와 지하수위의 영향성을 확인하였다. 이와같은 방법을 통해 궤도상 토공노반의 안정성을 확보할 수 있을 것으로 사료된다.

Long-Term Wildfire Reconstruction: In Need of Focused and Dedicated Pre-Planning Efforts

  • Harris, William S.;Choi, Jin Ouk;Lim, Jaewon;Lee, Yong-Cheol
    • 국제학술발표논문집
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    • The 9th International Conference on Construction Engineering and Project Management
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    • pp.923-928
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    • 2022
  • Wildfire disasters in the United States impact lives and livelihoods by destroying private homes, businesses, community facilities, and infrastructure. Disaster victims suffer from damaged houses, inadequate shelters, inoperable civil infrastructure, and homelessness coupled with long-term recovery and reconstruction processes. Cities and their neighboring communities require an enormous commitment for a full recovery for as long as disaster recovery processes last. State, county, and municipal governments inherently have the responsibility to establish and provide governance and public services for the benefit and well being of community members. Municipal governments' comprehensive and emergency response plans are the artifacts of planning efforts that guide accomplishing those duties. Typically these plans include preparation and response to natural disasters, including wildfires. The standard wildfire planning includes and outlines (1) a wildfire hazard assessment, (2) response approaches to prevent human injury and minimize damage to physical property, and (3) near- and long-term recovery and reconstruction efforts. There is often a high level of detail in the assessment section, but the level of detail and specificity significantly lessons to general approaches in the long-term recovery subsection. This paper aims to document the extent of wildfire preparedness at the county level in general, focusing on the long-term recovery subsections of municipal plans. Based on the identified challenges, the researchers provide recommendations for better longer-term recovery and reconstruction opportunities: 1) building permit requirements, 2) exploration of the use of modular construction, 3) address through relief from legislative requirements, and 4) early, simple, funding, and the aid application process.

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Mulliken 방법을 이용한 일측성 구순열의 장기 추적 결과 (Long term results in the unilateral cleft lip repair by Mulliken's method)

  • 김석권;문인선;이장호;허정;권용석;이근철
    • Archives of Plastic Surgery
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    • 제36권2호
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    • pp.174-182
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    • 2009
  • Purpose: The Mulliken's method is a one of the very excellent technique to correction of the unilateral cleft lip. It could decrease the need of additional operation and second operation by the early simultaneous correction of unilateral cleft lip and nasal deformity, at a time. Numerous procedures were advocated for the correction of nasal deformity, but with general dissatisfaction of the results, it became obvious that no one procedure is the ideal one. The authors have been operating on unilateral cleft lip by Mulliken's method and long term follow - up of postoperative result was evaluated. Methods: The authors have done long term follow - up of result in the 75 cases unilateral cleft lip patient, during 1 ~ 7 years. That was repaired by simultaneous correction of cleft lip and nasal deformity by Mulliken's method at the period from June, 1997 to December, 2007. The patients were unilateral complete cleft lip 39 cases, unilateral incomplete cleft lip 36 cases. In the severe complete cleft lip cases, lip adhesion operation was done before definite operation. The mean age of unilateral cleft lip operation was 3.2 months. Five anthropometric parameters, which were upper lip, cutaneous lip and vermilion mucosa height, nasal tip protrusion, columella length were measured by Sliding Vernier Caliper. The anthropometric analysis was performed preoperative and postoperative at 6 months, 3, 5 and 7 years and the results were com pared with those of age - matched, normal children. T - tests were used to analyze the differences between the measurements. Results: Long - term postoperative results were evaluated by anthropometrically. Most patients showed adequate growth of upper lip height, vermilion mucosa height and columella length. But nasal tip protrusion was relatively short compare with normal value. Incomplete cleft lip group was nearly normal growth results than complete cleft lip group. Conclusion: In conclusion, we could make harmonious Cupid's bow, natural philtrum and lip, appropriate nasal shape by Mulliken's method. But nasal tip protrusion was under the normal values on complete and incomplete group. And incomplete group was more good results than complete group. We have experienced repair of cleft lip by Mulliken's method with 75 cases of unilateral cleft lip patients and conclude that it was very useful and good method.

안양시 공공도서관 중장기 발전 계획 수립을 위한 현황 분석 및 운영 전략 연구 (A Study on the Current Status Analysis and Operation Strategies for Establishing the Mid- to Long-term Development Plans for Anyang Municipal Libraries)

  • 장인호;황금숙;송민선
    • 정보관리학회지
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    • 제39권1호
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    • pp.145-170
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    • 2022
  • 본 연구는 안양시의 정체성과 특수성을 고려한 도서관 중장기 종합 발전 계획 수립을 위한 운영 전략들을 도출하고자하는 목적으로 수행되었다. 이를 위해 본 연구에서는 다음과 같은 내용으로 진행되었다. 첫째, 안양시의 대내외 환경과 지역적 특수성 등을 파악하기 위해 안양시와 관련된 각종 문헌 자료 및 통계 자료들을 수집·분석해 정리하였다. 둘째, 「국가도서관통계시스템」 및 「경기도 공공도서관 연감」, 각종 도서관 관련 법규 등의 자료를 토대로 안양시 공공도서관의 운영 현황에 대해 파악하였다. 셋째, 안양시 공공도서관에서 근무하고 있는 사서 26명을 대상으로 안양시 정체성부터 현재의 도서관 운영 전반에 대한 의견을 수렴하기 위해 주관식 개방형 질문으로 구성한 설문조사를 실시해 분석하였다. 마지막으로, 앞서 정리한 현황 분석 내용과 최근의 도서관 트렌드, 정책 및 사회문화 환경 등을 반영해 향후 안양시 공공도서관의 중장기 발전 계획 수립의 토대가 될 수 있는 구체적인 운영 전략들을 ① 조직체계 및 인력 구성, ② 지역 간 균형 발전을 위한 시설 계획, ③ 장서 개발 및 보존 방향, ④ 특화주제 서비스 방안, ⑤ 협력체계 구축, ⑥ 홍보 방안의 여섯 가지 영역으로 구분해 제안하였다.

태양광발전시스템의 장기운전에 의한 성능특성 분석 (The Long-term Operating Evaluation of the Grid Connected Photovoltaic System)

  • 김의환;강승원;김재언
    • 신재생에너지
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    • 제7권2호
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    • pp.28-35
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    • 2011
  • Recently, photovoltaic systems have been devolved into much larger systems up to MW-scale. Photovoltaic industry participants give their focus on power generation capability of photovoltaic modules because their benefits can be decided from the amount of generation. The information on long-term performance change of photovoltaic modules helps to estimate the amount of power generation and evaluate the economic cost-benefits. Long-term performance of a PV system has been analyzed with operation data for 12 years from 1999 to 2010. In the first year, the amount of yearly power generation was 57.7 MWh with 13.2% capacity factor. In 2007, the amount of yearly generation was 44.3 MWh with 10.14% capacity factor, and in 2010, the amount was decreased down to 38.1 MWh with 8.7% capacity factor. The result means that long-term capacity factor has been 4.5% decreased for 12 years and that the amount of generation has been decreased 34.0% for 12 years which is 2.8 % per year. The latter capacity factor has been decreased faster than 0.20%, the average rate for 10 years. The performance decrease of the PV system is meant to be accelerated. The decrease of performance and utilization is due to aged deterioration of photovoltaic modules and lowering conversion efficiency of PCS.

A Study on the Long-Term Integrity of Polymer Concrete for High Integrity Containers

  • Young Hwan Hwang;Mi-Hyun Lee;Seok-Ju Hwang;Jung-Kwon Son;Cheon-Woo Kim;Suknam Lim
    • 방사성폐기물학회지
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    • 제21권3호
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    • pp.411-417
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    • 2023
  • During the operation of a nuclear power plant (NPP), the generation of radioactive waste, including dry active waste (DAW), concentrates, spent resin, and filters, mandates the implementation of appropriate disposal methods to adhere to Korea's waste acceptance criteria (WAC). In this context, this study investigates the potential use of polymer concrete (PC) as a high-integrity container (HIC) material for solidifying and packaging these waste materials. PC is a versatile composite material comprising binding polymers, aggregates, and additives, known for its exceptional strength and chemical stability. A comprehensive analysis of PC's long-term integrity was conducted in this study. First, its compressive strength, which is crucial for ensuring the structural stability of HICs over extended periods, was evaluated. Subsequently, the resilience of PC was tested under various stress conditions, including biological, radiological, thermal, and chemical stressors. The findings of this study indicate that PC exhibits remarkable long-term properties, demonstrating exceptional stability even when subjected to diverse stressors. The results therefore underscore the potential viability of PC as a reliable material for constructing high-integrity containers, thus contributing to the safe and sustainable management of radioactive waste in NPPs.

디젤 개질 가스로 운전되는 금속지지체형 고체산화물 연료전지의 운전 안정성에 관한 연구 (Stability of Metal-supported SOFC using Diesel Reformate)

  • 정지훈;백승욱;배중면
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 추계학술대회 초록집
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    • pp.78.1-78.1
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    • 2010
  • The metal-supported solid oxide fuel cell (SOFC) was studied. Hydrocarbon fueled operation is necessary to make SOFC system. Different operating characteristics for metal-supported SOFC are used than for conventional ones as hydrocarbon fueled operation. Metal-supported SOFC was successfully fabricated by a high temperature sinter-joining method and the cathode was in-situ sintered. Synthetic gas, which is compounded as the diesel reformate gas composition and low hydrocarbons was completely removed by the diesel reformer. Metal-supported SOFC with synthetic gas was operated and evaluated and its characteristics analyzed. Button cell and $5{\times}5cm^2$ single stack were mainly operated and analyzed. Long-term operation using diesel reformate shows degradation, and degradation analysis was completed in the view of metal oxidation. Solution to increase stability of long-term operation was tried in the way of materials and operating conditions. Finally, $5{\times}5cm^2$ metal-supported single stack using synthetic gas was operated for 1000 hours under the modified condition.

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호텔개발사업의 불확실성에 전략적으로 대응하기 위한 실물옵션 적용 연구 (A Study on Application of Real Option for Strategic Response to Uncertainty in Hotel Development Project)

  • 권태인;이상효;김재준
    • 한국디지털건축인테리어학회논문집
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    • 제10권2호
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    • pp.5-12
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    • 2010
  • Unlike housing development project that can ensure profit by selling built units, a hotel development depends on long-term business operation to be profitable due to characteristics of service industry. The expected cash flow has substantial uncertainty depending on room occupancy rate and room charge. Thus, even after construction is complete, business risk tends to rise. It is necessary to ensure strategic response to uncertainty in future value of a hotel. The objective of the study is to explore strategic measures to deal with risk and uncertain future value in hotel development project by adopting abandonment option, which is a type of real options. The case in analysis had sevenyears of project period: Two years for construction, and five years for operation; a plan was made to sell the hotel after five years' of operation. For the research purpose, option value ofrecoverable investment amount was estimated, and value of abandonment option was KRW 124.921 billion. When abandonment option is applied, the project value was deemed to be KRW 120.592 billion. Generally, the amount of loss is enormous when a real estate project like a hotel development fails, and therefore, application of option is expected to be an effective measure to leverage uncertainty of a project.

중규모 태양광발전시스템 장기 실증운전 평가 (The long-term operating evaluation of the grid connected photovoltaic system)

  • 김의환;안교상;임희천
    • 한국태양에너지학회 논문집
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    • 제29권5호
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    • pp.14-19
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    • 2009
  • The 50 kWp grid connected photovoltaic system which was installed at KEPRI site in 1999 has been operated more than 10 years. In order to acquire long term operation characteristics of medium size photovoltaic system, the operation test data related on power generation electricity and capacity factor of 50 kWp system, which have been collected since 1999, were analysed. From the analysing results, 57.7 MWh in annual power generation electricity of 50 kWp photovoltaic system in 1999 has been decreased 49.1 MWh in 2005 and reached 41.9 MWh in 2008. In addition to, the capacity factor of 50 kWp photovoltaic system also showed 13.2 % in 1999, 11.2% in 2005 and finally reached 9.6% in 2008. The operation test data showed a trend of decreasing of generation electricity and capacity factor during the 10 years operation time and we guessed that was caused by solar cell performance degradation and decreasing of PCS system efficiency.

방사성폐기물 처분장 부지감시 계획 (Site Monitoring and investigation plan for LILW disposal)

  • 백승종
    • 방사성폐기물학회지
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    • 제6권4호
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    • pp.369-385
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    • 2008
  • 부지감시 및 조사의 목적은 운영 전, 운영중 및 폐쇄 후 단계에서 변화가 예상되는 주요 부지특성을 지속적으로 감시함으로써 방사성폐기물처분장의 성능평가 및 설계에 필요한 기초자료를 제공하는 것이다. 부지감시의 단계별 주요내용은 다음과 같다. 운영전 단계에는 부지의 적합성 평가 및 처분장 건설과 운영에 필요한 주요 부지특성을 감시하며, 운영 중 단계에는 안전하고 효율적인 운영과 환경에 미치는 영향을 판단하기 위하여 주변지역을 포함하여 주요 부지특성을 감시한다. 폐쇄 후 단계에는 처분장의 방사성 물질로 인한 영향을 사전에 예방하고, 처분장의 장기적 안전성을 위하여 필요한 주요 부지특성 항목을 감시한다.

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