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        검색결과 127

        62.
        2004.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 직선 강상자형 거더의 단면변형에 의한 변형 및 응력계산을 위한 Matlab 해석프로그램을 개발하고자 한다. 이를 위하여 단면변형이론을 요약하고 빔유사이론을 제시한다. 이후 탄성지반위의 보-기둥부재의 지배방정식을 제시하고, 일반화된 고유치해석을 통하여 집중 및 분포하중을 받는 보요소의 엄밀한 강성행렬을 계산한다. 본 연구의 효율성과 정확성을 입증하기 위하여 격벽을 갖는 상자형 거더의 뒤틀림응력을 계산하고 유한요소해와 비교한다.
        4,000원
        63.
        2003.08 구독 인증기관 무료, 개인회원 유료
        Ocjective : Sabaeksan has been used for the purpose of prevention and treatment of bronchial asthma and allergic asthma in korea. Methods : To investigate the biological effect of Sabaeksan, the author examined cytotoxicity and inflammatory cytokines secretion with human leukemic mast cell line, HMC-1. HMC-1 was stimulated with phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187. Sabaeksan by itself had no effect on viability of HMC-1. Result : The effects of Sabaeksan on the secretion of tumor necrosis factor-alpha (TNF- α) and interleukin (IL)-6 from HMC-1 were evaluated with enzyme-linked immunosorbent assay. Sabaeksan (1 ㎎/㎖) inhibited PMA plus A23187-stimulated TNF-α and IL-6 secretion, by 43.86 ± 5.26%, 56.39 ± 3.65%, respectively. Sabaeksan also inhibited the NF-κB (p50/p65) expression. Conclusion : Taken together, these results suggest that Sabaeksan inhibit the production of inflammatory cytokines in HMC-1 cells through blockade of NF-κB activation.
        4,200원
        64.
        2000.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        야외 학습의 많은 이점에도 불구하고, 중 고등학교에서는 야외 지질 활동이 잘 이루어지지 않고 있다. 최근에 지질 답사 지역이 많이 개발되고 있으나, 대부분 지질학적 층서에 관한 서술적 설명으로 기재되어 있어 중 고등학생들에게 적합하지 않다. 따라서 전문적인 내용보다는 지구과학 교사가 손쉽게 학생들을 데리고 야외로 나갈 수 있는 야외 학습 프로그램이 필요한 실정이다. 본 연구는 중 고등학생을 위한 야외 지질 학습장을 개발하고 이를 효과적으로 수행할 수 있는 교수 학습 전략을 제시하여 일선 지구과학 교사들에게 도움을 주고자 한다.
        4,000원
        65.
        1997.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        기존의 전자 기판에서 땜납으로 사용되고 있는 Sn-Pb계 합금을 대체하기 위한 새로운 합금을 개발하기 위하여 열역학을 이용한 상평형계산을 통해 얻은 다원계 상태도를 바탕으로 적정한 녹는점과 용융구간을 가지는 Sn-Bi-In-Zn계 솔더합금을 설계하였다. 설계된 합금을 제작하여 XRD, DSC및 EDX로 분석하여 상의 확인,조성분석 및 고상점과 액상점 등의 녹음 거동을 확인하였다. 또한 열처리에 따른 미세구조의 변화를 관찰하였고, 이러한 조직변화가 기계적 성질에 미치는 영향을 경도실험과 인장실험을 통해 연구하였다.
        4,000원
        66.
        2019.10 서비스 종료(열람 제한)
        공용 중인 교량의 건전성을 파악하고 유지관리에 활용하기 위해 서해대교 사장교 구간에는 구조건전성모니터링(structural health monitoring) 시스템이 설치되어 있다. 이를 통해 바람, 지진과 같은 작용하중(applied loads)과 함께 진동, 형상변화, 신축, 부재력, 응력(변형률)과 같은 구조응답(structural response)을 모니터링하고 있다. 2000년 준공 이후 현재까지 장기간 축적된 구조응답 데이터를 기반으로 분석 및 평가를 수행한 결과, 상시 거동뿐만 아니라 다양한 재난상황 시에도 교량 구조계의 거동은 건전한 상태임을 확인할 수 있었다.
        67.
        2019.04 서비스 종료(열람 제한)
        This paper discusses the loads on bridges based on long-term measurements. Applied Loads such as winds, earthquakes, temperature variations and traffic effects have been monitored on an existing bridge from the completion of the structure to now. It is confirmed that the monitoring results are within the design values.
        68.
        2018.04 서비스 종료(열람 제한)
        Recently, there has been frequent shortage of expansion joint in expressway bridges. When that happens, maintenance budgets will be overloaded and not effective, so it is not easy to come up with a solution. In this study, we introduce a bridge inspection system that combines laser image sensing technology and automatic control technology, which have been recently applied in various fields. And this system was developed to measure bridge extension joints while traveling 100km/h.
        71.
        2017.09 서비스 종료(열람 제한)
        Recently, there has been frequent shortage of expansion joint in expressway bridges. When that happens, maintenance budgets will be overloaded and not effective, so it is not easy to come up with a solution. In this study, we introduce a bridge inspection system that combines laser image sensing technology and automatic control technology, which have been recently applied in various fields. And this system was developed to measure bridge extension joints while traveling more than 80km/h.
        72.
        2017.08 KCI 등재 서비스 종료(열람 제한)
        For effective control of insect pest which can outbreak in a field during crop cultivation, various control agents such as eco-friendly agricultural materials (EFAM) including microbial control agents and chemical pesticides have been applied at fields and these control agents may be treated simultaneous or sequential in the same field to suppress diverse pests and diseases. The agents may influence each other and control efficacy may also differ from interactions. Therefore we need to test compatibility of microbial control agents with other agricultural agents. In this study, we investigated influence of pre-treated EFAMs, which are registered for whitefly control in greenhouse, on germination, mycelial growth and control efficacy of Isaria javanica isolate against sweet potato whitefly. The results showed that a mixture of paraffin oil+cinnamon oil among 4 EFAMs highly reduced germination (8.9±1.3%~24.5±0.9%) and mycelial growth (0.81±0.01cm~0cm) of I. javanica. To investigate the effects of the treatment interval between EFAMs and I. javanica on sweet potato whitefly control, four different EFAMs were pre-treated 0, 1, 4, and 7 days before applying I. javanica. Pre-treatment of four EFAMs inhibited insecticidal activity of I. javanica against sweet potato whitefly. Therefore when EFAMs and a mycopesticide using I. javanica spray simultaneous or sequential, application of EFAMs need more than 7 days interval after treatment of mycopesticide at field.
        73.
        2017.05 KCI 등재 서비스 종료(열람 제한)
        Foot mechanisms play the role of interface between the main body of robotic systems and the ground. Biomimetic design of the foot mechanism is proposed in the paper. Specifically, multi-chained and multiple contact characteristics of general foot mechanisms are analyzed and their advantages are highlighted in terms of impulse. Using Newton-Euler based closed-form external and internal impulse models, characteristics of multiple contact cases are investigated through landing simulation of an articulated leg model with three kinds of foot. It is shown that in comparison to single chain and less articulated linkage system, multi-chain and articulated linkage system has superior characteristic in terms of impulse absorption as well as stability after collision. The effectiveness of the simulation result is verified through comparison to the simulation result of a commercialized software.
        74.
        2017.04 서비스 종료(열람 제한)
        Due to limited human resources, budget and difficulties in accessibility, inspections are not available at proper time. Advanced Technology such as ICT, Sensing, and AI can innovate the management of structure. So, we introduce our developed equipment and future management plan.
        75.
        2017.04 서비스 종료(열람 제한)
        Recently, there has been frequent shortage of expansion joint in expressway bridges. When that happens, maintenance budgets will be overloaded and not effective, so it is not easy to come up with a solution. In this study, we introduce a bridge inspection system that combines laser image sensing technology and automatic control technology, which have been recently applied in various fields. And this system was developed to measure bridge extension joints while traveling more than 80km/h.
        76.
        2017.04 서비스 종료(열람 제한)
        The internal displacement of the corrugated steel plate structure reduces structural stability. In this study, we developed a smart checking system to evaluate the stability of the corrugated steel plate culvert structure by laser scanning and image mapping. It is expected that output data can be used in inspecting deformation rates between designs and measured 3D shapes. Also, it can solve the problems in current visual inspection and systemize the inspection tasks scientifically.
        77.
        2017.04 서비스 종료(열람 제한)
        The internal displacement of the corrugated steel plate structure reduces structural stability. In this study, we evaluated the stability of the corrugated steel plate culvert structure using an inspecting deformation rates between designs and measured 3D shapes. Also, a proper repair and reinforcement method will be proposed through analytical and experimental verification
        78.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        도시화에 의한 인구집중과 불투수율 증가, 강우강도 증가는 도시침수피해의 주원인이다. 도시침수피해를 줄이기 위해 도시 내 지형/지물의 영향 을 고려하고 상세 침수지역을 모의할 수 있는 침수해석모델이 필요하다. 본 연구에서는 2차원 천수방정식을 이용한 격자기반 침수해석모델 (GIAM)을 개발하였다. 대상지역은 논현, 역삼, 서초3~5의 5개 배수분구를 포함하는 강남지역 7.4 km2이며 맨홀 월류량은 EPA SWMM5를 이 용하여 산정하고 6 m 격자크기에 대해 침수모의가 가능하도록 모델을 구축하였다. 모델 적용성 평가를 위해 분석기간은 2010년 9월 21일과 2011년 7월 27일 호우사례를 선정하였다. 모델 정확도를 평가하기 위해 침수피해가구 현황을 이용하여 POD를 분석한 결과 각각 0.61과 0.57의 정확도를 보였다. 개발된 모형은 강우시나리오에 따른 침수취약지역 추정과 실시간 침수예측을 위한 도구로 활용될 수 있을 것으로 판단된다.
        79.
        2017.01 KCI 등재 서비스 종료(열람 제한)
        Due to limited human resources, budget and difficulties in accessibility, inspections are not available at proper time. Advanced Technology such as ICT, Sensing, and AI can innovate the management of structure. So, we introduce our developed equipment and future management plan.
        80.
        2017.01 KCI 등재 서비스 종료(열람 제한)
        Recently, there has been frequent shortage of expansion joint in expressway bridges. When that happens, maintenance budgets will be overloaded and not effective, so it is not easy to come up with a solution. In this study, we introduce a bridge inspection system that combines laser image sensing technology and automatic control technology, which have been recently applied in various fields. And this system was developed to measure bridge extension joints while traveling more than 80km/h.
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