검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 805

        661.
        2014.04 KCI 등재 서비스 종료(열람 제한)
        국내 진단용 방사선 발생장치는 3년 주기로 시행되는 정기적인 정도관리 검사에 앞서 일별, 주별, 월별, 분기 반기별로 시행하는 수시 정도 관리에 대한 항목 및 규정이 명확하게 지정되어 있지 않다. 미국과 유럽 등의 선진국에서는 정도 관리 항목에 대해 검사를 수행하는 검사자를 구분하여 국가 기관에 보고하도록 되어 있으므로 체계적인 검사 수행과 더불어 검토가 가능하다. 그러므로 의료 장비의 현대화가 이루어지는 시점에서 국외의 주기별 정도관리 시스템을 국내 진단용 방사선 발생 장치에 적합하도록 도입하여 정도관리 항목과 기준의 재정립이 반드시 필요하다. 이에 본 논문에서는 진단용 방사선 발생장치 중 가장 빈번히 사용되고 있는 일반 X선 촬영 장치의 3년 정기점검 사이에 주기적인 수시 정도 관리 검사 항목과 방법 및 기준 수립을 위해 미국, 캐나다 등의 국외 문헌 조사 및 국제 전자 기술 위원회(International Electro-technical Commission, IEC)의 규정 항목과 비교하였다. 이를 바탕으로 국내 수시 정도관리 항목 신설 시 필요한 검사 항목 및 기준 설정을 위한 기초 자료로 제시하고자 하였다.
        662.
        2014.04 서비스 종료(열람 제한)
        In this study, a noncontact NDT method is implemented to detect the damage of pipeline structures and to identify the location of the damage. To achieve this foal, an Nd:YAG pulsd laser system is used to generate guided waves and a galvanometer-based laser scanner scans a specific area to find damage location. Then, a piezoelectric sensor is installed to measure structural responses. The measured time and spatial responses are transformed to data in frequency and wavenumber domain through 3-dimensional Fourier transform. Finally, damages can be detected by extracting reflected signals due to damage using wavenumber filter which eliminated strong incident waves.
        663.
        2014.04 서비스 종료(열람 제한)
        The purpose of this study is to estimate and quantify the effect of carbonation of concrete on a surface electrical resistivity measurement. Samples of three mixes with difference W/C ratios were prepared and exposed in a carbonation chamber for up to 330 days. The results show that carbonation leads high electrical resistivity. The increase is substantial and has been shown to proportional to the extent of the carbonation by some of extent. The relationship between electrical resistivity and carbonation depth is taken in the study. Resistivity ratio of carbonated concrete to air concrete decreased significantly from the specific carbonation depth, however, Resistivity ratio of carbonated concrete to air concrete had a linear relation with carbonation depth.
        664.
        2014.04 서비스 종료(열람 제한)
        In light of the maintenance of underground structures, the evaluation scope of precise inspection for safety and diagnosis have been revised. Crack, leakage, deterioration, and drainage system are evaluated with field inspection in maintenance manner. It also proposed that the additional revision of the precise inspection for safety and diagnosis.
        666.
        2014.04 서비스 종료(열람 제한)
        The purpose of this study is to development inspection, diagnosis and utilizing manual for facilities such as bridges, tunnels, and buildings. For this, firstly, the classification system about inspection and diagnosis equipment was established and that was divided in accordance with the intended use(durability, safety, equipment, environment). based on this, the manual was developed including specification, performance of equipment and using, managing and controling for the inspection and diagnosis work.
        667.
        2014.04 서비스 종료(열람 제한)
        The Korean electric power industry autonomously developed the Korea Electric Power Industry Code (“KEPIC”) with political support from the government with a view to creating domestic codes and standards for electric power facilities. Since KEPIC was initially issued in November 1995, the Korea Electric Association (“KEA”) has consistently updated it, developing new codes and standards like Structural Maintenance Inspection and so on.
        672.
        2014.01 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 레이저 가진을 이용한 초음파 전파 영상 기반 배관 비파괴 검사에 관해 다룬다. 손상의 영상화를 위해 갈바노미터 기반레이저 미러 스캐너와 Q-Switch Nd: YAG 레이저 시스템을 사용하였다. 레이저 시스템을 가진원으로 사용하면 빠른 속도로 비접촉 초음파 가진이 가능하며, 온도의 변화가 급격한 환경이나 유해 물질이 포함된 환경에서도 대상 구조물의 원거리 가진이 가능하다. 또한 공간해상도가 높으며, 입사각이 넓어 표면 형상이 복잡한 대상 구조물도 가진이 가능하다. 본 연구에서는 이러한 레이저 시스템으로부터 생성된유도 초음파를 단일 PZT 센서를 사용하여 계측하고, 계측된 신호는 레이저 가진점에 해당하는 좌표점에 나열함으로써 2차원 공간좌표 및시간축을 더한 초음파 전파 영상 생성을 위한 3차원 데이터를 구성한다. 이 데이터를 시간 축에 따라 연속적으로 반복 재생하면 초음파 전파 영상을 구할 수 있다. 이 때 웨이블릿 변환을 이용하여 계측 신호의 특정 주파수 성분을 추출해냄으로써 관찰하고자 하는 특정 유도 초음파 모드를 추출할 수 있다. 이러한 일련의 과정으로부터 획득한 초음파 전파 영상 데이터를 시간-공간 영역에서 주파수-wavenumber 영역으로 변환시켜줌으로써 손상 특성을 추출할 수 있다. 본 연구에서는 손상의 진단 및 위치 추정을 위해 wavenumber 필터링 기술을 적용하였으며, 시스템 검증을 위해 다양한 배관구조물 Testbed를 대상으로 실험을 수행하였다.
        673.
        2013.12 서비스 종료(열람 제한)
        After percutaneous endoscopic lumbar discectomy (PELD), postoperative radiating leg pain could persist and become a common problem. This symptom provides important information for use in deciding on performance of reoperation for remnant disc or recurrent disc herniation. Of 225 patients who underwent PELD, 51 patients had persistent radicular pain. Steroid injection to epidural space resulted in pain reduction of at least 50 % in 15 (30.3 %) of these patients. Thirty five cases showed a bad outcome after steroid injection, indicating high sensitivity for detection of a remnant or disc herniation in follow up Magnetic Resonance images (25 cases, 71.4%). Twenty one patients were treated by reoperation. Steroid injection has a diagnostic value with a high sensitivity for mechanical compression of the nerve root as remaining or recurrent disc herniation in MRI for the necessity of a re-operation.
        674.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        In this study, it propose what the landscape elements is to be improved urgently and how to improve landscape by reflecting the rural village characteristics away from the spatial integrated landscape planning. The study area for landscape research is selected as the 9 rural villages in Chungcheongbuk-do, and research is done by using village unit landscape diagnostic index(VULDI). the result is shown that average VULDI value of the rural village zones is bigger than one of the town village zones with difference of 15%. Two zones of Chilseong-myeon and Sangchon-myeon among the town village zones are appeared to be similar with the rural village zones in landscape level by VULDI value. Generally, the rural villages to maintain the good landscape have the low population and high engagement rate in agriculture. Looking political support criteria at the landscape level, the seven zones except Deoksan-myeon and Maengdong-myeon have high VULDI value more than 60%, which means that it seems unnecessary to support political landscape improvement. However, when it is divided into two parts of the village inside landscape and the surrounding landscape, 8 rural village zones except one zone of Sangchon-myeon have low VULDI value less than 60%, which means it is necessary to support political landscape improvement. It is important to give the intensive support of ever urgent landscape improvements and high priority landscape elements on the results of the diagnostic before planning of the rural landscape formation.
        675.
        2013.10 서비스 종료(열람 제한)
        In this study, after performing a full-scale dynamic testing of unreinforced masonry buildings, the experimental results and developed seismic performance evaluation program of existing unreinforced masonry buildings were verified by comparing the results of the program.
        676.
        2013.10 서비스 종료(열람 제한)
        In this study, plant pipeline diagnosis system based on IoT(Internet of Things)was developed. The system consists of three parts : sensor system, omnicube system and pipeline safety assessment solutions. The plant pipeline diagnosis system was constructed in plant pipeline and was validated field applicability. Plant pipeline diagnosis system based on IoT is appropriate for plant pipeline safety monitoring.
        678.
        2013.10 서비스 종료(열람 제한)
        In this study, an automated cable non-destructive test (NDT) system was proposed to monitor the steel cable. Magnetic Flux Leakage (MFL) method was applied for the cable inspection. A multi-channel MFL sensor head was fabricated using Hall sensors and permanent magnets. A wheel based Cable climbing robot was used to improve the accessibility to cable. In addition, remote data transmission and robot control were possible by applying the Wireless LAN communication. Finally, developed element techniques were integrated to MFL based Cable Climbing NDT system, and the field applicability of the integrated cable NDT system was verified through a field test.
        679.
        2013.09 KCI 등재 서비스 종료(열람 제한)
        In this study, it provides the diagnostic index for the rural landscape formation. For the development of diagnostic index, this study first analyzed documents and papers on the landscape formation. Landscape types are also classified by their function and then landscape index was developed by AHP method. Classification system was categorized as three steps: 2 items for 1st step, 10 items for 2nd step, and 20 items(criteria) for 3rd step. In the survey of weighting values with AHP method, the analysis result for the first step showed that rural village landscape is more important than landscape around the village by approximately 20%. In the second step, residence is rated as the most important, followed by village tree planting, and then farmland around the rural villages, greenery, and water environment. In the third step, the feng shui is rated as the most important, followed by tree planting, village forest, culture, and history. While vehicle maintenance, village alleys and pedestrian facilities are rated lower. In index of the around the village, weighting value for index of the farm land and skyline has the highest value. While species richness, water quality and water resources were rated relatively low. In the future, the rural landscapes diagnosis index will be applied to measure the level of the rural villages landscapes and it is expected to propose political support for the landscapes formation.
        680.
        2013.09 서비스 종료(열람 제한)
        대상구조물은 준공 후 6년 경과된 창고용도의 구조물로서 폭설이 내리는 도중 창고 지붕(Arch Panel)과 서측에 면한 기둥 및 벽체부분이 붕괴사고가 발생됨에 따라 붕괴원인과 붕괴사고 후 남아있는 구조체의 안전성 여부를 확인하기 위하여 건물주의 요청에 의해 정밀안전진단을 실시하게 된 것이다. 따라서, 관련된 도면 및 현재 시공상태를 비교 검토하고 붕괴된 부분과 붕괴되지 않은 구조물에 대해 외관조사와 비파괴조사(콘크리트 강도시험, 철근배근탐사 등)를 수행하여 구조부재의 상태와 손상정도를 파악한다. 또한, 지붕 및 기둥 붕괴에 관련한 하중을 검토하여 구조물의 안전성여부를 확인하기 위해 구조검토를 수행한다. 수행된 결과들을 종합적으로 검토하여 붕괴원인을 검토 분석하고 붕괴되지 않은 부분에 대한 보수⋅보강 여부를 제시하는 것을 목적으로 한다.