• 제목/요약/키워드: Nexus

검색결과 239건 처리시간 0.023초

NEXUS를 이용한 비행안전 필수 소프트웨어 검증환경 개발 (Development of Verification Environment for Flight Safety Critical Software using NEXUS)

  • 윤형식;한종표
    • 한국항공우주학회지
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    • 제40권6호
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    • pp.548-554
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    • 2012
  • 항공기 비행조종컴퓨터 탑재 소프트웨어는 항공기의 손실뿐만 아니라 조종사의 생명에도 직결되는 비행안전 필수 소프트웨어로서 정확성과 무결성을 입증하기 위한 검증 및 확인(Verification & Validation)이 요구된다. 특히 비행안전 필수 소프트웨어는 검증을 위해 통합시험 단계에서 실제 환경과 유사한 운용 환경에 노출하여 소프트웨어 내부 상태를 실시간으로 모니터링하기 위한 환경이 요구된다. 본 논문에서는 표준 디버깅 인터페이스인 NEXUS 5001을 이용한 비행안전 필수 소프트웨어의 검증환경 개발에 대하여 기술하였다.

물-에너지-식량 넥서스를 활용한 통합적 농업자원관리정책 평가 - 지하수 함양 사업을 중심으로 - (The Evaluation of Integrated Agricultural Resource Management Policy through Water-Energy-Food Nexus - An Application to Management of Aquifer Recharge Project -)

  • 성재훈;이현정;조원주
    • 농촌계획
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    • 제25권4호
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    • pp.35-45
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    • 2019
  • Korean agriculture experienced rapid changes in its production structure to respond fluctuations on external conditions, and these changes have increased the dependence between agricultural resources and negative environmental externalities from agricultural production. As a tool for managing agricultural resources and reducing negative environmental effects from agricultural production, this study employs water-energy-food nexus for integrated resource management. To show the necessity of an integrated approach, this study evaluated three policy scenarios including changes in capital interest, water capacity, and energy cost. The results show that three scenarios have unintended consequences for farmers' incomes and their use of resources. Also the unintended consequences of government policies also affected farms' vulnerability to environmental changes. In particular, the expansion of financing for the establishment of non-circulating water curtain facilities did not have a significant effect on the crop switching of farms. In addition, increasing the amount of available water through the aquifer recharge project leads to the installation of non-circulating water curtain facilities in zucchini farm. It raises dependence on groundwater in agricultural production, thereby increasing farmers' vulnerability to groundwater shortages. These results imply that the agricultural sector needs to consider the interrelationship between agricultural resources when designing or evaluating policies.

도재라미네이트 접착용 레진시멘트의 색조 안정성에 관한 연구 (A STUDY ON THE COLOR STABILITY OF RESIN CEMENTS LUTED FOR PORCELAIN LAMINATE VENEER)

  • 김영운;박하옥;방몽숙;양홍서;박상원
    • 대한치과보철학회지
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    • 제45권2호
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    • pp.191-202
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    • 2007
  • Statement of problems: Long-term success of esthetic restorations, depends on various factors, especially on color stability of the restorations. The color stability is affected by resin cements beneath the porcelain laminate veneers. Purpose: The purpose of this study was to comprehend the color stability of resin cements by comparing with 4 different kinds of resin cements (Choice, Variolink II, Nexus 2, Rely-X). Material and methods: Porcelain laminate disk samples were luted with resin cements. After thermocycling of each 1000, 2000 and 3000 cycle, specimens were measured by spectrophotometers and the color differences were. Results: 1. After thermocycling of 1000, 2000 and 3000cycle, color difference, $({\Delta}E^*)$ of all specimens were incresed, but were not statiscally significant differences. 2. In the Choice of A1 shade and the Nexus 2 of A3 shade, color difference$({\Delta}E^*)$ after thermocycling of 3000cycle was $incre^*ased$ significantly than after thermocycling of 1000cycle. However, other groups did not show any statistically significant differences (P<0.05). 3. After thermocycling of 3000cycle, color difference$({\Delta}E^*)$ between A1 shade and A3 shade of Nexus 2 showed statistically significant difference. However no statistically significant differences were observed in other groups (P<0.05). 4. The mean of color difference$({\Delta}E^*)$ is 1.0-2.06 after 3000 thermocycling and the data were ranked in the ascending order of Variolink II, Nexus 2, Choice and Rely-X in A1 shade group and Choice, Rely-X, Variolink II and Nexus 2 in A3 shade group. Conclusion: Above results revealed that, after 3000 thermocycing, the color difference $({\Delta}E^*)$ of experimental resin cements was within clinically acceptable ranges. Color stability of 4 different resin cements was comparatively excellent.

습지보호지역의 습지보전·이용시설 현황에 관한 기초 연구 - 5개 습지보호지역을 대상으로 - (Fundamental Research of Preservation & Utility Facilities in Wetland Protected Area - 5 Wetland Protected Areas were Used as Main Subjects -)

  • 조동길;박용수;심윤진;이지현;이동진;김상혁;차진열;박미영;송유진;남춘희;김종철;문상균
    • 한국환경복원기술학회지
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    • 제19권1호
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    • pp.25-43
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    • 2016
  • This research was completed to provide fundamental data regarding the guidelines to installing and managing utility facilities & structures in wetland protected area to advance the functions and sustainable use of ecology services by preserving the ecology within wetland protected area. There were 5 on-site researching areas that were used as the main subject with these areas chosen and considered from 21 inland wetlands that have been designated and are being managed from the Ministry of Environment and by their designated dates as a wetland protected area. The utility facilities in these wetland areas were categorized by their types and a detailed on-site investigation was proceeded with investigation items chosen whereas these facilities are working by their roles from their location, size, used materials, types, information contents and etc., The results showed that regarding informational structures, several locations of information boards were distanced from the main exploring routes which did not consider the visitor's eye level which had their readability dropped and by sunlight, time lapse and water penetration, many information boards were damaged or corrupted so that it was hard to confirm the information noticed or understanding an image. Insufficient observation and educational structures were installed that considered the ecological characteristics of wild animals and their living conditions. Regarding convenience facilities, there were parking lots that were installed on the fore-land and to decrease non-point solution sources, some parking lots needed to be located in protected lowlands while some facilities' shape and colors did not harmonize with their natural surroundings, creating a sense of awareness, which will need some more consideration. As for safety facilities, they were very insufficient compared to other facilities. This means that additional safety structures are needed so that related personnel can be aware of where a visitor is located when an accident occurs. Protectional facilities strongly needed new structures and a management system to cut off entrances and do surveillance so that visitors do not go into areas outside of the managed areas and bring damages to restricted locations. Research labs needed to expand the use of automatic weather systems and water gauge equipments to build fundamental data regarding floodgates that are intimated to the forming of wetlands. Sensor cameras and other types of monitoring systems are needed to monitor the majority types of animals living in the wetlands as well.

물-에너지 넥서스 관점에서 외부영향과 운영관리 수준이 도시물순환시스템에 미치는 영향 (The effect of external influence and operational management level on urban water system from water-energy nexus perspective)

  • 최서형;신봉우;송영석;김동균;신은허
    • 한국수자원학회논문집
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    • 제56권9호
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    • pp.587-602
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    • 2023
  • 기후변화, 인구증가 및 경제발전으로 도시물순환시스템 내 용수 수요량과 물 이용에 필요한 에너지는 지속적으로 증가하고 있다. 따라서 도시물순환시스템을 효율적으로 관리하기 위해 물 부문만을 고려하는 전통적인 방식을 벗어나 물과 에너지 부문 간 상승효과와 상충관계를 고려하는 넥서스 접근법이 주목받기 시작하였다. 이러한 넥서스 방법론을 적용하여 도시물순환시스템이 에너지 집약적인 시스템임을 증명하고, 에너지 원단위로 표현되는 물-에너지 효율 관계를 분석하며, 기후(장기 기후변동, 가뭄, 유형), 지리적 특징(표고차, 평지비, 위치), 시스템 특징(총급수량, 인구, 인구밀도, 관로연장) 및 운영관리 현황(상수관망 수압, 누수율, 물절약)이 미치는 영향을 규명하고자 하는 연구들이 수행되어왔다. 그러나 이를 통해 도시물순환시스템 관리자에게 정책 및 제도의 방향을 제시할 수 있으나 구체적인 정책을 수립하고 시행하는 데 한계가 있었다. 본 연구에서는 기존에 제시된 문헌 조사를 통해 시스템 및 공정별 에너지 원단위 매트릭스 구축하고, 물-에너지 넥서스 모델을 활용하여 도시여건, 외부영향 및 운영관리수준이 시스템에 미치는 영향을 정량화하였으며, 관리자가 벤치마킹할 수 있는 물-에너지 사용효율 기준을 제시하였다. 이를 활용하여 도시물순환시스템 관리자는 시스템의 효율적인 운영관리를 위한 전략과 실행계획을 도출할 수 있으며, 계획의 시행 후 적합성 및 타당성에 대한 평가가 가능할 것이다.