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        검색결과 41

        21.
        2017.10 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 보강토 옹벽 점검 자료를 바탕으로 보강토 옹벽의 상태평가항목의 가중치를 새롭게 제안하고 결함점수 및 결함지수 를 제안하였다. 161개소의 보강토 옹벽의 점검결과를 근거로 다중회귀분석과 엔트로피 기법을 이용하여 상태평가항목별 가중치를 산정하였 으며, 또한 전문가를 대상으로 AHP 기법을 활용하여 평가항목별 가중치를 산정하였다. 각 기법에서 도출된 가중치를 활용하여 혼한 가중치를 제안하였으며, 제안 가중치를 토대로 결함점수 및 결함지수를 제안하여 기존 161개소 현장에 적용하여 현재의 가중치와 제안 가중치에 의한 현장별 위험도 순위를 비교 분석하였다. 다중회귀분석, AHP 기법, 엔트로피 기법을 활용하여 분석한 결과 상태평가항목의 가중치 순위가 변동 이 컸으며, 현재 상태평가항목의 가중치와 달리 가중치 순위의 중복은 발생하지 않았다. 특히, 다중회귀분석 결과에서는 특정 상태평가항목이 전체 가중치의 70% 이상을 차지하는 결과가 도출되었다. 제안한 혼합 가중치를 기존 보강토 옹벽 데이터에 적용한 결과, 상태평가항목의 가중 치 중복은 발생하지 않았으며, 대상 보강토 옹벽 161 개소 중 16 개소의 위험도 순위 상승과 31 개소의 위험도 하락이 발생하였다.
        22.
        2017.05 서비스 종료(열람 제한)
        현재 국내에서 발생하는 음폐수의 해양투기 금지 및 음식물류 폐기물의 에너지화 정책에 따른 유기성 폐기물 육상처리의 일환으로 혐기소화를 통한 바이오가스화 시설이 지속적으로 설치 및 운영되고 있다. 그중에서도 음식물쓰레기는 처리 단가가 높고, 바이오가스 회수 잠재력 또한 높아 바이오가스화 시설의 경제성을 높여줄 유용한 폐자원으로 여겨지고 있다. 하지만 국내 발생 음식물쓰레기의 평균 고형물함량(TS)이 18~20% 수준으로 혐기소화를 통한 바이오가스화 이전에 전처리가 필수적이며, 단순 파쇄/선별을 통한 물리적 전처리만으로는 충분한 가용화가 어려운 부분이 있다. 이러한 유기성폐자원의 가용화를 위한 전처리 방법에는 가수분해/산발효를 통한 생물학적 처리, 산, 알칼리, 오존 등을 통한 화학적 처리, 초음파, 열, 압축 등에 의한 물리적 처리 등이 있는데 본 연구에서는 물리적 처리방법 중 하나인 열가수분해를 통한 음식물쓰레기의 가용화효율을 분석하였다. 이를 위해 1차로 물리적 파쇄/선별 처리한 음식물쓰레기에 대해 다양한 운전 조건(온도, 압력 변화)으로 열가수분해를 실시하여 각 운전조건별 음식물쓰레기 성상변화를 분석함으로써 음식물쓰레기 열가수분해를 위한 최적 운전조건을 도출하고자 하였다.
        23.
        2017.04 서비스 종료(열람 제한)
        The safety issue of PSC box girder bridge stood out. So, we developed material testing method and procedures and applied them to existing bridge. Consequently, We found that the procedure we developed is very reasonable.
        24.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        The objective of this study was to find a rapid determination of the hot air stress in maize (Zea mays L.) leaves using a portable chlorophyll fluorescence imaging instrument. To assess the photosynthetic activity of maize leaves, an imaging analysis of the photochemical responses of maize was performed with chlorophyll fluorescence camera. The observed chlorophyll imaging photos were numerically transformed to the photochemical parameters on the basis of chlorophyll a fluorescence. Chlorophyll a fluorescence imaging (CFI) method showed that a rapid decrease in maximum fluorescence intensity (Fm) of leaf occurred under hot air stress. Although no change was observed in the maximum quantum yield (Fv/Fm) of the hot air stressed maize leaves, the other photochemical parameters such as maximum fluorescence intensity (Fm) and Maximum fluorescence value (Fp) were relatively lowered after hot air stress. In hot air stressed maize leaves, an increase was observed in the nonphotoquenching (NPQ) and decrease in the effective quantum yield of photochemical energy conversion in photosystem II (Φ PSII). Thus, NPQ and ΦPSII were available to be determined non-destructively in maize leaves under hot air stress. Our results clearly indicated that the hot air could be a source of stress in maize leaves. Thus, the CFI analysis along with its related parameters can be used as a rapid indicating technique for the determining hot air stress in plants.
        25.
        2016.10 서비스 종료(열람 제한)
        By amending of the special law on the safety management of the facility, coastal structures(breakwaters) has been incorporated into kinds of facilities. In this paper, a case study for condition assessment of coastal structures(breakwaters) is conducted according to the detailed guidelines established for coastal structures(breakwaters).
        26.
        2016.06 KCI 등재 서비스 종료(열람 제한)
        MTBE and other gasoline additives contained in gasoline are known to be a refractory substance resistant to biodegradation. As a method of removing these substances, a research of method using native microbes of polluted soil was progressed and among these, bio-degradation possibility under aerobic condition was evaluated. All of the experiments were progressed based on batch experiment of lab scale and analyzed by GC-FID using HS-SPME technique. The result of bio-degradation experiment based on MTBE and other additives(ETBE, TAME) was observed below 1 mg/L, which initial concentration were 100 mg/L for each method. And through production of by-product and CO2, partial mineralization was confirmed. Degradation velocity of each additive was promptly represented in the order of TBA>ETBE>MTBE>TAME. Through this study, bio-degradation possibility of native microbes of oil polluted soil, MTBE and other gasoline additives was confirmed and it was considered that the result could be used for basic experiment data in removing oil pollutants of soil.
        27.
        2016.04 서비스 종료(열람 제한)
        In this study, we analyzed the effect of the drainage slope to collapse. The presence of drainage has a low correlation with the collapse of the slope. But drainage of the drainage has an important role in preventing the decay slope. Therefore, the drain state is very important in order to evaluate the drainage.
        28.
        2016.04 서비스 종료(열람 제한)
        In this study, repair and reinforcement priority determining method for each component of existing dams is suggested. Condition assessment results from in-depth inspection followed by “specific guide for in-depth inspection on dams” are used. Condition assessment is subdivided into several steps and evaluation indices are determined by considering weights such as influence coefficients and adjustment factors for each component through all of the steps. These weights are counted backward to determine the priority for each component and facility. An algorithm is designed to analyze this procedure and 4 target dams are adopted to verify the method. This method can be used for establishing an efficient maintenance strategy related to the repair and reinforcement priority determination.
        29.
        2016.04 서비스 종료(열람 제한)
        이 연구에서는 플랜트 지하구조물의 상태평가를 위해 국내외 기준을 확인하고 플랜트 지하시 설의 핵심평가 요소 도출을 통하여 향 후 플랜트 지하구조물의 상태평가를 위한 기초 자료로 활용하고자 한다.
        30.
        2016.04 서비스 종료(열람 제한)
        By amending of the special law on the safety management of the facility, pumping station has been incorporated into kinds of facilities. In this paper, a case study for condition assessment of pumping station is conducted according to the detailed guidelines established for pumping stations. Evaluation index between new and existing guideline is compared.
        31.
        2016.04 서비스 종료(열람 제한)
        This study has been considering cable stayed bridge for structural health monitoring purpose . To monitor the bridge, 6 different locations (like 2 points from deck, 2 points from pylon, 1 points from side span and 1 points from girder) were introduce to find the satellite signal received from the GPS antenna. According to the World Geodetic System 1984(WGS-84) coordinate system, the GPS station signal was measured in the 6 observed points. After that, Statistical moment analysis is applied to assess the condition of those 6 position of this long span bridge. Finally, the Statistical moment analysis results clearly indicate the present condition of the long span bridge at 6 different locations. The time series statistical moments really able to detect the damage condition and localization of the long span bridge.
        33.
        2014.10 서비스 종료(열람 제한)
        Multi-physics nondestructive evaluation(NDE) technologies were proposed for monitoring section-loss and breakage of strands and tendons in prestressed girders moved from an actual bridge. The primary NDE technologies include Magnetic flux(MFL), Electrical resisticity(ER), Half-cell Potential (HCP), and Linear-polarization(LPR).
        34.
        2014.10 서비스 종료(열람 제한)
        This study suggests and examines the ways of asset valuation on maintenance scenario for bridge facilities. In order to evaluate each scenario on the basis of the same time, the concepts of the condition assessment data are introduced and applied. The main purpose of this study is to suggest asset valuation method, which is practical in conformity with domestic situations, through researches on asset valuation method of bridge facilities. As a consequence, the management and maintenance system of existing highway facilities needed an innovation involving the concept of asset management. This study discusses the new facility management system suitable to local highway agencies. The developed system improves the current methods of establishing the bridge maintenance strategy and can be utilized as an efficient tool to provide the optimum bridge maintenance scenario and corresponding to the various constraints and requirements of bridge agency.
        35.
        2014.04 서비스 종료(열람 제한)
        Currently the seismic performance evaluation for existing buildings are being made simply through the review of the analytical technique corresponding to design specifications on beam, column, shear wall, joint and so on. Also the seismic performance is evaluated to 4 steps as immediate occupancy level(IO), life safety level(LS), collapse prevention level(CP), collapse occurrence level(CO). However, in case of a structure being used for a number of years after construction, which may have partial damages and durability degradations may show significant differences between the analysis results and the actual behavior during an earthquake. Therefore, a improved seismic performance assessment is proposed based on risk assessment and seismic performance techniques since more systematic evaluation and condition assessment are required, and thus the practical and economical seismic retrofit measures for the existing facilities and for the reasonable seismic design as well are to be developed more than ever before.
        36.
        2014.04 서비스 종료(열람 제한)
        This study was performed to decide weight of an objective evaluation factors so optimized for small reservoirs and reservoirs that operators may survey their status and identify relevant risk factors in a timely way. In this study, evaluation factors were determined based on the expert panel results followed by the brain storming process. The selected evaluation factors were implemented on the formulation of hierarchy and analytic hierarchy process (AHP) technique were used to determine weight factors based on the expert survey results. It is expected that the use of the proposed weight will contribute to the more systematic and efficient safety management of small reservoirs to prevent their failures.
        37.
        2012.11 KCI 등재 서비스 종료(열람 제한)
        교량에서의 바닥판은 통행차량의 쾌적하고 안전한 주행성 확보하는 역할을 가진다. 동시에 교통하중의 충격 등에 의한 마모 및 전단에 저항하여 상부 구조를 보호하거나 빗물 등의 기타 기상작용이나 화학약품 등 상판의 악영향으로부터 바닥판을 보호하는 역할을 한다. 현재 일반국도상 교량은 총6,248개소로서 이를 효과적으로 관리하기 위하여 현재 차량탑재형 GPR시스템의 도입이 검토되고 있다. 본 연구에서는 교량 및 터널 현황조서 및 기타 국토해양부의 자료를 바탕으로 교량의 재령별, 상부구조형식별, 지역별, 경간장별 바닥판 상태평가등급을 분석하였다. 결과적으로 교량 바닥판 조사 우선순위 결정인자로는 바닥판 상태평가등급, 상부구조 형식, 재령, 연장이 주요 인자인 것으로 도출되었다.
        38.
        2012.06 KCI 등재 서비스 종료(열람 제한)
        담수에서 사육한 감성돔 Acanthopagrus schlegeli(담수감성돔) 냉동/해동 정자의 생존율이 가장 높았던 결빙억제제(cryprotective agent, CPA)는 dimethyl sulfoxide(DMSO)였으며, 다음으로 glycerol, ethylene glycol(EG) 그리고 methanol 순이었다. 해동 후 정자운동성은 glycerol, DMSO, EG, methanol 순으로 높았으며, 이상의 결과들은 해수에서 사육한 감성돔(
        39.
        2009.06 KCI 등재 서비스 종료(열람 제한)
        금강수계중 용담댐하류 앞섬 지점에서 생태유량을 산정하기 위한 생태 모니터링을 실시하여 어류종별 서식환경 특성조사를 포괄적으로 실시하였다. 이를 바탕으로 어류상, 상대풍부도 및 생물다양도 분석 등을 포함한 하천의 건강성 평가를 실시하고, 쉬리, 피라미 및 감돌고기 등에 대하여 작성한 서식처적합도 지수(HSI)와 물리적 서식처 모의시스템(PHABSIM)을 이용한 최적 생태유량을 산정하였다. 본 지점에서 채집된 종수는 20종이였으며, 우점종은 쉬리(22.4%
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