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        검색결과 6,504

        4801.
        2018.11 KCI 등재 서비스 종료(열람 제한)
        Organic agriculture is well known to be not only affecting the physical and chemical status of the soil but also closely connected to the biodiversity through complex community structure and ecological interactions. Current study monitored and analyzed the invertebrate biodiversity of organic and conventional paddy fields and upland fields from April, 2017 to August, 2017. Total of 680 species (with 14,371 individuals) were confirmed - more number of species were identified at the organic agriculture practicing fields. According to the various indices analysis, organic paddy field showed about 40% higher diversity index, while organic upland field showed about 10% higher diversity index. Richness index at organic paddy field was 60% higher compared to conventional paddy field, while organic upland field showed 40% higher value. Dominance and evenness index at conventional agriculture practicing fields were low, which possibly indicate at least partial dominance phenomenon. Hemipteran, dipteran and aranean species showed highest diversity in all fields, while dipteran, hemipteran, aranean and coleopteran species had highest diversity in conventional agriculture practicing fields.
        4802.
        2018.11 KCI 등재 서비스 종료(열람 제한)
        내진 성능 학보를 위해서는 신축이음장치가 지진력에 대하여 적절한 변형이 발생하여 신축이음장치의 파괴를 방지하여야 하는데 최근에 국내에서 신축이음장치의 핑거부에 힌지를 설치하여 교축방향의 지진력에 대한 변위 저항성을 확보한 신제품이 개발되고 있다. 이에 본 논문에서는 가변형 핑거 조인트를 가지는 신축이음장치에 대하여 실물규모의 교축직각방향 하중에 대한 저항성을 실험적으로 평가하였다. 실험결과, 최대 수평변위는 기존 신축이음 실험체의 경우 약 21.1mm, 내진 신축이음 실험체의 경우 51.00mm로 나타났으며, 기존제품은 추가적으로 16.5mm의 솟음이 발생되었다. 기존 신축이음 실험체는 어느 정도의 교축직각 방향의 하중에 대하여 저항한 후, 핑거의 휨 및 전단 변형이 과도하게 발생되며 파단 현상이 발생할 가능성이 있을 것으로 추정된다. 반면에 내진 신축이음 실험체의 경우, 교축 직각방향의 하중에 대하여 하중에 대한 변형을 핑거의 힌지가 흡수하여 신축이음장치 및 상부구조에 응력을 발생시키지 않고 다만 하중 작용방향으로의 수평 변형만 발생시킬 것으로 예상된다.
        4803.
        2018.11 KCI 등재 서비스 종료(열람 제한)
        최근 산업 활동에 의해 발생하는 CO2에 대한 처리와 산업부산물에 대한 유효처리 및 자원화 방안이 시급히 요구되고 있다. 본 연구는 콘크리트 혼합재료로 활용이 가능한 산업부산물를 대상으로 탄산화 양생에 의한 건설재료로의 적용성 평가를 목적으로 한다. 이러한 목적을 위해 연구용 시멘트(research cement, RC), 고로슬래그 미분말(GGBFS) 및 유동층 보일러 애시(CFBC)를 대상으로 탄산화 양생에 의한 물리·화학적 변화를 비교 검토하였다. 페이스트 내부의 미세조직 변화를 살펴보기 위해 XRD, SEM 분석을 수행하였다. 실험결과 탄산화 양생을 통해 생성된 반응 생성물인 탄산칼슘은 페이스트 내부의 공간을 채우며 밀도가 높은 미세 구조를 형성함을 확인하였다. 또한, CO2 양생시간이 길어짐에 따라 탄산칼슘 결정이 함께 성장하여 밀실한 미세구조를 이루는 것을 확인하였다.
        4804.
        2018.11 KCI 등재 서비스 종료(열람 제한)
        최근 남해안과 제주도 연안에는 5,000톤 이상의 괭생이 모자반이 유입되어 양식장과 조업에 큰 피해를 주고 있으며, 환경훼손 등 사회적 문제로 부각되고 있다. 괭생이 모자반에 존재하는 알긴산은 주로 의약품, 식품 등으로 활용되는 천연 고분자 물질이다. 하지만, 대량으로 활용할 수 있는 수요처가 확보되지 않아 본 연구에서는 괭생이 모자반을 활용한 바이오 폴리머를 구조물 보수용 폴리머 모르타르에 활용하기 위한 연구를 수행하였다. 응결특성 평가 시험에서는 바이오 폴리머가 12% 혼입된 L0BP12 배합은 합성폴리머만 혼입된 L12BP0 배합보다 종결시간이 최대 20%증가하는 것을 확인하였다. 흡수율 시험에서는 LOBP12 배합이 초속경 시멘트 배합인 Plain-URHC보다 0.36% 감소하는 것으로 나타나 바이오 폴리머 혼입으로 모르타르의 수밀성이 증가하는 것을 확인하였다. 압축 및 휨강도 시험에서는 바이오 폴리머의 혼입이 증가할수록 강도가 감소하는 경향을 나타내었고, KS F 4042 기준을 만족하는 최대 바이오 폴리머의 혼입률은 12%로 결정되었다. 또한, 재령 4시간 기준 부착강도는 Plain-URHC시험체 보다 모두 향상되었으며, 1 MPa 이상을 확보하여 바이오 폴리머의 혼입이 모르타르의 부착강도를 향상 시킬 수 있는 것을 확인하였다.
        4805.
        2018.11 KCI 등재 서비스 종료(열람 제한)
        논문은 바닥 격막을 고려한 초고층 아웃리거 구조시스템의 수평거동을 파악하기 위하여 80층 규모의 초고층 아웃리거 건물을 대상으로 MIDAS-Gen을 이용하여 계획설계 수준의 구조설계를 진행하였다. 그리고 본 해석의 주요한 변수는 아웃리거의 평면상 위치, 슬래브의 강성, 아웃리거의 강성, 다이어프램의 종류이다. 또한 본 연구의 목적을 위하여 최상층에서 발생하는 수평변위, 층간변위, 슬래브에 발생한 응력을 분석하였다. 본 연구의 결과, 아웃리거의 평면상 위치, 슬래브의 강성, 아웃리거의 강성, 다이어프램의 종류는 초고층 아웃리거 구조시스템의 수평거동에 영향을 주는 것으로 나타났다. 그리고 본 연구의 결과는 초고층 아웃리거 구조시스템의 수평거동을 파악하는데 필요한 구조설계 기본자료를 얻는데 도움이 된다고 사료된다.
        4806.
        2018.10 서비스 종료(열람 제한)
        Background : Ginseng seeds are harvested in immature stages and take 3 - 4 month to be germinated following cold stratification. Improvement of germination speed can be a valuable traits to be characterized for economically important medicinal plant. Modulation of cell wall compositions is also considered as another agricultural trait when the crops can be processed for foods and forages. Here we show the functional characterization of ginseng pPLAIIIβ focused on its possible values on germination and modulation of cell wall compositions. Methods and Results : Patatin-related phospholipase AIII family genes were identified from ginseng EST clones and further confirmed by PCR. Clone showing the highest homology with pPLAIIIβ was overexpressed in model plant Arabidopsis, and it displayed dwarf plants. qPCR analysis showed that pPLAIIIβ expressed in all organs of 2-years-old ginseng. Overexpression of ginseng pPLAIIIβ also displayed apparently enlarged seeds as well as altered germination speed in early stage compared to the control. Chemical stainings and direct quantification of lignin and cellulose were performed to understand the link of cell elongation patterns and cell wall compositions. Conclusion : Overexpression of ginseng pPLAIIIβ inhibited longitudinal cell elongation in all tested organs except seeds which is enlarged in both directions than the control. Shorter root length is related with auxin responsive genes and its dwarf morphological phenotype is resulted in altered cell wall compositions.
        4807.
        2018.10 서비스 종료(열람 제한)
        Chloride penetration into concrete is the main cause of the corrosion of steel in concrete structures exposed to chloride-rich environments. As a preventive or remedial method, surface treatments on concrete have been increasingly applied to both new and existing concrete structures to combat this problem. So far, knowledge of how a surface treatment reduces chloride diffusion is limited and the relationship between chloride diffusion resistance and surface treatment parameters, such as thickness, porosity and diffusion coefficient, has not been quantitatively identified. In this paper, chloride ion penetration modeling is performed to predict the service life of the surface treated concrete.
        4808.
        2018.10 서비스 종료(열람 제한)
        The importance of maintenance in steel structures is to be emphasized according to increase of their service time. To protect the corrosion damages, the repainting on steel bridges are usually applied every 10 to 13 years by visual inspection. However, the coating durability was rapidly decreased by airborne salt under marine environment. In this study, the time-dependence deposited salts were measured at several types and locations of structural member in marine bridge.
        4809.
        2018.10 서비스 종료(열람 제한)
        The clogging of transverse drainage pipes in NATM tunnel is attributed to the hydraulic pressure generated on the outside of lining concrete and affects the safety of the whole structure in the long term, necessitating a keen attention in terms of its maintenance. Accordingly, this paper will introduce an analysis on the effect of the clogging of transverse drainage pipes on the lining structure based on the comparison between the inspection of the clogging of transverse drainage pipes and the visual inspection (leakage, efflorescence).
        4810.
        2018.10 서비스 종료(열람 제한)
        In this study, an experimental test is conducted on a concrete specimen using passive thermography (IRT) which is an effective and modern non-destructive test (NDT) method in detecting delaminations. The present work evaluates the detectability of delaminations with different sizes during the daytime by the absolute contrast technique. In addition, the most suitable time for delamination inspection of concrete structures is also proposed.
        4811.
        2018.10 서비스 종료(열람 제한)
        This study is aimed at developing a wireless unified-maintenance system (WUMS) that would satisfy all the requirements for a disaster preventive SHM system of civil structures. The WUMS is designed to measure diverse types of structural responses in realtime based on wireless communication, allowing users to selectively use WiFi RF band and finally working in standalone mode by means of the field-programmable gate array (FPGA) technology. To verify its performance, the following tests were performed: (i) A test to see how far communication is possible in open field, (ii) a modal test on a bridge to see how exactly characteristic real-time dynamic responses are of structures. Finally, the WUMS is proved valid as a SHM, and its outstanding performance is also proven.
        4812.
        2018.10 서비스 종료(열람 제한)
        There are several techniques to build the lumped-mass stick model, which are tributary-area based conventional model, frequency adaptive model, and advanced model combining the conventional and frequency adaptive models. The present study is to compare the seismic response accuracy of the models including FE model. The target structure is a nuclear containment structure and 45 earthquake ground motions are considered for the seismic analysis. The results show that the advanced lumped-mass model provides similar and more consistent responses to the FE model, compared to other models.
        4813.
        2018.10 서비스 종료(열람 제한)
        An experimental study was conducted to examine for the structural behavior of coupled steel plate shear wall (Coupled SPSW) system what is formed by connection the two steel plate shear walls (SPSW) with a coupling beam. The variable of this study was the length of coupling beam. The testing results were showed that the strength and stiffness of specimen with shorter coupling beam were improved than those of other specimen. However there is no difference of the yielding mechanism.
        4814.
        2018.10 서비스 종료(열람 제한)
        This paper was conducted to evaluate structural performance of modular system connection with bracket. It was evaluated to two external connection specimens and two internal connection specimens. As a result of experiment, excessive shear deformation of the bracket was observed in all of the specimens. However, all of the specimens satisfied the requirement for intermediate moment frames (IMF) targeted in the experiment.
        4815.
        2018.10 서비스 종료(열람 제한)
        The concrete vacuum tube structure, which must maintain air-tightness, is manufactured in the form of a segment, and it is necessary to install the joints at uniform gap in order to assemble in the field. In this study, member tests were carried out to investigate the air-tightness performance at the joints of the concrete vacuum tube structures.
        4816.
        2018.10 서비스 종료(열람 제한)
        This research presents one of new architectural SUPER concrete structural members which were designed with nonuniform curvilinear shapes. SUPER concrete had the compressive strength of 80MPa to 200MPa, the tensile strength of 8MPa to 20MPa, and had high ductile tensile strains. Nonuniform concrete formwork were invented and specimens were manufactured to verify by test.
        4817.
        2018.10 서비스 종료(열람 제한)
        This study examined lateral load behaviors of partially grout filled steel tube from structural analysis. To evaluate structural resistant behaviors of partially grout filled steel tube, Nonlinear FE analysis model of partially grout filled steel tube was considered using ABAQUS program. From FE analysis results, grout filling effect and thickness effect of steel tube on the lateral load behaviors were compared.
        4818.
        2018.10 서비스 종료(열람 제한)
        Structural behavior of blast-resistant door composed with steel plate and inner con’c core was analyzed according to composite and non-composite condition. The results showed that maximum and permanent deflection decrease in the case of composite condition. And as the impact on blast-resistant door increases and radical deformation occurs, there is not much difference in the deflection of the door.
        4819.
        2018.10 서비스 종료(열람 제한)
        This paper presents the design and construction technology for the big common basemat of safety related nuclear buildings. New regulation guide of U.S NRC SRP 3.8.5 affects the basic design concept and construction specification of the common basemat.
        4820.
        2018.10 서비스 종료(열람 제한)
        In this study, we proposed a modified design equation for SC walls subjected to local impact load based on a series of experimental studies on the impact resistance of SC walls. Then, the results of the modified design equation was evaluated and verified based on the extensive experimental test data as well as numerical parametric analysis data. Finally we confirmed that the modified design equation provided reasonable results.