검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 406

        141.
        2018.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Structure behaviors resulting from an earthquake are experimentally simulated mainly through a shaking table test. As for large-scale structures, however, size effects over a miniature may make it difficult to assess actual behaviors properly. To address this problem, research on the hybrid simulation is being conducted actively. This method is to implement numerical analysis on framework members that affect the general behavior of the structure dominantly through an actual scale experiment and on the rest parts by applying the substructuring technique. However, existing studies on hybrid simulation focus mainly on Slow experimental methods, which are disadvantageous in that it is unable to assess behaviors close to the actual level if material properties change depending on the speed or the influence of inertial force is significant. The present study aims to establish a Real-time hybrid simulation system capable of excitation based on the actual time history and to verify its performance and applicability. The hybrid simulation system built up in this study utilizes the ATS Compensator system, CR integrator, etc. in order to make the target displacement the same with the measured displacement on the basis of MATLAB/Simulink. The target structure was a 2-span bridge and an RC pier to support it was produced as an experimental model in order for the shaking table test and Slow and Real-time hybrid simulations. Behaviors that result from the earthquake of El Centro were examined, and the results were analyzed comparatively. In comparison with the results of the shaking table test, the Real-time hybrid simulation produced more similar maximum displacement and vibration behaviors than the Slow hybrid simulation. Hence, it is thought that the Real-time hybrid simulation proposed in this study can be utilized usefully in seismic capacity assessment of structural systems such as RC pier that are highly non-linear and time-dependent.
        4,000원
        144.
        2018.04 구독 인증기관·개인회원 무료
        방충포장 상용화 연구를 위하여 선정된 천연기피물질을 이용한 방충포장 소재를 개발하고 이들의 저장해충에 대한 방충효과를 시험하였다. ㈜농심의 라면포장 박스의 접착제로 사용되는 핫멜트에 0, 2%의 기피물질을 처리하고 화랑곡나방에 대한 방충효과를 시험한 결과, 2% 기피물질이 처리된 방충 핫멜트 처리구와 무처리구 간 화랑곡나방 개체수는 박스외부에서는 차이가 없었으나(df=30, t=0.56, P>0.05), 박스의 골판지 틈새(df=30, t=6.78, P<0.05)와 박스내 부(df=30, t=2.45, P<0.05)에서는 처리구에서 유의하게 적게 나타났으며, 무처리구와 처리구 박스내부 전체(박스내부+ 골판지 틈새)와 박스 전체에서 발견된 화랑곡나방 개체수도 처리구에서 유의하게 적은 것으로 조사되었다 (내부전체: df=30, t=13.58, P<0.05, 박스전체: df=30, t=13.60, P<0.05). 화랑곡나방 유충이 발견된 위치는 무처리구와 처리구 모두에서 박스외부가 가장 적었으며, 박스내부와 골판지 틈새의 순으로 조사되었으며 전체적으로 처리구에서 유의하 게 적게 발견되었다.
        145.
        2018.04 구독 인증기관·개인회원 무료
        Matsucoccus thunbergianae is the main forest insect pest of the Japanese Black Pine (Pinus thunbergii) in the west, south and east coast of South Korea. The main damage pattern appears to be the cumulative damage over many years by the second instar fixed under the pine bark. The adult male has a pair of wings and is attracted sex pheromone emanating from the adult female so that during the mating period (Generally, middle period of March) adult male is attracted to the adult female which has no wing. Using this mating behavior from the adult male, we developed sex pheromone trap to reduce mating success rate by reducing the density of the adult male in the field. In this study, In the indoor induction experiments and the field experiments, sex pheromone trap showed high induction effect on the adult male. Thus, we expect to reduce the damage to the Japanese Black Pine by Matsucoccus thunbergianae.
        146.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 어선전복경보시스템 개발을 위해 어선의 횡동요 특성을 파악하고 시간영역 횡동요 운동 시뮬레이션을 수행한다. 어 선전복경보시스템의 검증을 위해서는 전복 상황을 가정하여 시험을 수행하고 실제 어선 계측을 수행해야 하지만, 상황의 위험성으로 인 해 현실적으로 불가능하다. 또한 많은 전복사고의 경우 횡동요와 밀접한 연관이 있는 것으로 조사되었다. 이에 따라 어선전복경보시스템 의 핵심인 어선의 횡동요특성을 정확히 파악하여 시간영역 기반 횡동요 시뮬레이션을 수행하고 해당 정보를 통해 시스템에 탑재된 경보 시스템의 알고리즘을 검증한다. 주요내용으로 첫째, 횡동요 운동 특성을 운동 시험을 통해 계측하고 파악한다. 특히 어선과 같은 소형선 박의 경우 CFD 및 포텐셜 코드를 포함한 해석적인 방법으로 점성과 관련된 횡동요 해석이 어렵다. 이에 따라 횡동요 운동 모드에 초점을 맞추어 운동 시험을 수행하고 횡동요 RAO를 도출한다. 둘째, 횡동요 RAO를 이용하여 Wave Spectrum과의 조합으로 시간영역 운동 시뮬레 이션을 수행하고 전복 경보 알고리즘을 검증한다.
        4,000원
        147.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구의 목적은 강남 선정릉지역에서 전산유체역학모델(CFD)을 사용하여 도시지역의 흐름 및 열 환경 모의를 검증하는 것이고, CFD 모델의 모의결과와 선정릉 지역의 관측 자료와 비교하는 것이다. CFD 모델은 국립기상과학원과 서울대가 공동으로 연구 개발된 모델이다. CFD_NIMR_SNU 모델은 기상청 현업 모델인 국지예보모델(LDAPS)의 바람성분과 온도성분을 초기 및 경계조건으로 적용되었고 수목효과와 지표 온도를 고려하여 2015년 8월 4일에서 6일까지 강남 선정릉 지역을 대상으로 수치실험을 진행하였다. 선정릉지역에서 수목효과 적용 전후의 풍속을 비교하였을 때 평균 제곱근 오차(RMSE)는 각각 1.06, 0.62 m s−1로 나타났고 수목효과 적용으로 풍속 모의정확도가 향상되었다. 기온은 LDAPS 과소 모의하는 경향을 나타내고 CFD_NIMR_SNU 모델에 의해 향상된 것을 확인하였다. CFD_NIMR_SNU 모델을 이용하여 복잡한 도시지역의 흐름과 열 환경을 자세하고 정밀한 분석이 가능하며, 도시 환경 및 계획에 대한 정보를 제공 할 수 있을 것이다.
        4,500원
        148.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Zhuxi, who epitomized the thought of neo-Confucianism, not only has an effect on Chin ese idealist philosophy during the Song, Yuan, Ming and Qing dynasties,but has a direct i nfluence on Korean social philosophy during the Korean Age. Hong Tae-Yong is a well- k nown scholar in the later stage of the Korean Age, his theory with Zhuxi‘s became the tw o main schools on the Korean’s thinking. Zhuxi explored some problems in the field of epistemology with the theory of Ge Wu Z hi Zhi. Beyond that, he made a few opinions about verification theory and the opinions g et the clearer in his old age. He was becoming more interested in natural science, and th e thought about verification theory was frequently found in his later writings. In the resear ch about natural scientific problems, he had adopted observation, experimentation and pra ctice method. Zhuxi has opened up a new area and bends and laid the theoretical founda tions for verification theory. Hong Tae-Yong carried on some theoretical results of the Zhu xi on the one hand, and made his own pragmatical learning, on the other hand. In his th eory, the methodology occupied a central place. This thesis has taken the postivist theory as research objects, discusses about Hong Tae-Yong's pragmatical learning by comparing with Zhuxi's Verification Theory. He proved some opinions by the recognizing method of practice, observing methods and the recognizing method of practice. Hong Tae-Yong be d ivorced from Zhuxi's theory and have created a new pragmatical learning by these objecti ve methods. As has been described above, the main differences between the two is understanding th e “Shi(实)”. Hong Tae-Yong attaches great importance to truthful information, truthful circu mstances, truthful experiment and actual practice, He has made great efforts in recognizin g the real things, and has verified them one by one through practice. His objective metho d have helped take his thought off the ZhuZi's Philosophy and have created pragmatical l earning.
        4,600원
        149.
        2017.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        원자력 발전 이후에 누적되는 사용후핵연료를 해소하기 위한 다양한 연구가 시도되고 있으며, 특히 건식으로 사용후핵연료 를 재활용하는 파이로 공정이 주목되고 있다. 파이로 공정의 공학규모 실증을 위하여 대형 공정셀을 구비한 PRIDE 시설이 구축되었다. 파이로 공정에 사용되는 용융염의 화학반응성을 고려하여, 공정셀 내부는 아르곤 분위기를 유지한다. 결과적으 로, 작업자가 공정셀 내부에 진입할 수 없으며, 공정셀 내부에 설치된 모든 공정장치는 원격수단에 의해 공정셀 밖에서 원격 조작을 통해 수행한다. 따라서, 공정셀에 설치되는 공정장치는, 설계단계에서 부터 원격작업을 고려하여 설계되어야 하며, 공정셀에 반입하기 전에 원격으로 작동이 가능한지 철저히 검증하여야 한다. 만약, 공정셀에 반입되어 작동하는 단계에서 문제가 발생하는 경우, 장치를 반출하여 수정한 후 재반입하기까지 많은 비용과 시간을 허비하게 된다. 공정장치의 원격성 검증을 위하여, 물리적인 목업을 사용할 뿐 아니라, 설계단계에서 3D 모델을 활용한 가상 검증이 가능하다. 본 연구는, 가상공간에 PRIDE 공정셀을 구성하고, 설계된 공정장치 3D 모델을 입력하여, 원격조작성을 검증하기 위한 PRIDE 3D 시뮬레이터 개발에 관한 것이다. 실제 PRIDE 공정셀의 형상과 공정셀에 설치되는 원격운전 및 유지보수 장치의 움직임을 가상공간에 구현하고, 공정장치의 3D 모델을 실제 설치할 장소에 위치할 수 있도록 하였다. PRIDE 공정셀에 설치 될 전해공정장치의 전극교체 작업을 시뮬레이션 시나리오로 설정하여, 개발된 PRIDE 3D 시뮬레이터의 사용성을 검증하고 자 하였다. 8단계로 이루어진 원격작업 시나리오를 구성하여, 각 단계의 원격작업을 성공적으로 모사함으로써, PRIDE 공정 셀의 원격성 평가를 성공적으로 수행하였다.
        4,000원
        153.
        2017.10 구독 인증기관·개인회원 무료
        In Volvariella volvacea, a species of edible mushroom, cryogenic autolysis is a typical part of abnormal metabolism. Previous functional annotation cluster analyses of cold-induced gene expression profiles have shown that the ubiquitin-conjugating enzyme E2 (UBE2) and the cyclin-like F-box domain (FBDC) form the functional clusters. Among them, a specific FBDC gene has been found to be in response to cold stress and correlated with the cryogenic autolysis of V. volvacea. In this study, analysis of gene expression profiling showed that only one type of UBE2 in V. volvacea (UBEV2) was significantly up-regulated. Further quantitative real-time PCR analysis confirmed that the expression of UBEV2 was significantly up-regulated (P < 0.05) after cold-treatment lasting 4, 6, and 8 h. Western-bolt analyses confirmed that the protein expression of UBEV2 was in response to cold stress. This provided evidence that UBEV2 was a cold stress-responsive gene and closely correlated with cryogenic autolysis. The specific distribution of UBEV2 in recently diverged herb decay fungi indicated that UBEV2 was not evolutionarily correlated with early diverging fungi. Phylogenetic analysis indicated that UBEV2 was generated by horizontal gene transfer (HGT) from the ancestry of Selaginella moellendorffii UBE2. Further relative time estimation and detection of natural selection showed that there has been recent positive selection after HGT in UBEV2. Molecular modeling and logo analysis showed that the cysteine-cysteine motif is the characteristic of the UBEV2 family. These observations indicate that UBEV2 and FBDV1 are the newly discovered cold stress-responsive genes correlated with the cryogenic autolysis of V. volvacea.
        154.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 보다 넓은 범위에서 영상기반 변위계측 시스템의 동특성 추정 신뢰성을 확보하기 위해 Shaking Table을 이용해 넓은 대역의 진동수와 진동수별 다양한 진폭에 대한 Sine Wave 동적실험을 실시하였다. 영상기반 변위계측을 위해 DDVS(Dynamic Displacement Vision System) 기법을 활용하였으며, DDVS 기법을 통해 구한 동적변위는 기존의 접촉·비접촉식 센서인 LVDT(Wire Type, Pole Type)과 LDS의 변위계측 결과와 비교하여 그 오차를 분석하였다. 구해진 동적변위를 FFT하여 진동수 영역에서의 정확도 비교도 함께 수행하였다. 4가지 타입의 계측센서 모두 동적변위계측 결과 최대 변위 도달 및 주기 운동 계측에 있어 대체적으로 유사한 결과를 나타냈으며, 특히 영상기반의 DDVS 기법과 LDS를 통한 계측 결과는 높은 상호 일치성을 보였다. LDS와의 비교를 통한 오차분석 결과, DDVS 기법에 의한 동적변위 계측의 정확도는 계측 대상의 진동수에 영향을 받는다고 판단되었다. 동일 가진 진동수 내에서 가해준 변위 변화에 의한 오차는 미미하였으나, 동일 발생 변위에서는 가진 진동수가 커질수록 오차 값이 증가하였다. 기존 센서인 LVDT 경우, 발생 변위가 작을 때 상대적으로 큰 오차를 나타냈으며, 이를 통해 진동계측과 같은 작은 동적변위의 계측에 한계가 존재한다고 판단된다.
        4,000원
        155.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, measures for reducing noise and vibration of a railroad station are actively being developed to enhance its property value and comfort level of passengers. In this paper, the applicability of the recently developed vibration mitigation method utilizing a platform TMD (Tuned Mass Damper) by installing a spring-damper system beneath the platform is experimentally verified using a bench scale structure. The two-story bench scale structure is built to simulate a real railroad station, and vibration reduction effect is verified by comparing acceleration before and after applying the platform TMD at the 2nd floor of the structure. The design parameters of the platform TMD system is determined based on vibration analysis result and the MTMD (Multiple TMD) theory recently developed to enhance the effectiveness of the platform TMD method. The vibration is excited to the bench-scale structure using a vibrator. The performance test result for a spring-damper system is also presented. The result of the experiment reveals that the platform TMD method can reduce the vibration of the bench-scale structure by greater than 5dB(V).
        4,000원
        157.
        2017.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The renewable energy sources can be thought of one of the major measures to reduce greenhouse gas emissions in the industries. However, the utilization technology for those sources is approaching in the different matters. One of them, thermoelectric generation might be applicable to fishing industry. A various of internal combustion engines are used in a wide range of fisheries. After the ignition process, the heat passed out from the exhaust outlet. Recycling the heat could be not only an energy source but also reduction of green gas emission. Therefore, this study was designed to verify the feasibility of generation from wasted exhaust gas and analyze the performance. The designed experiment devices were connected with a data logger and an electric loader to quantify the currency and voltage. The devices were installed in a coastal fishing vessel for a gillnet fishery. During the whole fishing trips, the amount of generation was measured by engine rpm and the fishing operation procedures including vessel operations. At the maximum 1,500 rpm in the practical range, the generation amount was 113.6 W. The amount difference in relation to connection method was within 5 W: serial connection was 111.4 W and parallel connection was 115.8 W.
        4,000원
        158.
        2017.04 구독 인증기관 무료, 개인회원 유료
        During the last two decades, fiber reinforced polymer (FRP) reinforcing bars for concrete structure have been extensively investigated and a number of FRP bars are commercially available. However, major shortcomings of the existing FRP bars are its high initial cost and low elastic modulus compared to conventional steel bars. Because of these reasons, Korea Institute of Civil Engineering and Building Technology (KICT) in Korea has developed the FRP Hybrid Bar which have the concept of material hybridization for concrete structures, especially for marine and waterfront concrete structures. This developed bar is new type material in construction field, verification of long term performance is very important for commercialization. In this paper, verification methodology on long term performance(corrosion, flexural behavior etc) of FRP Hybrid Bar is suggested.
        3,000원
        159.
        2017.04 구독 인증기관 무료, 개인회원 유료
        SSG(self-healing smart grouting) method, has the characteristics such as an improvement of durability and waterproofing, prevention of leaching and pollution. In this study, several tests were performed such as gel-time measurement, uniaxial compression test, permeability test, chemical resistance test to compare the engineering properties of SSG with the other chemical grouting method(LW, SGR). As results of tests, the SSG method has low possibility of groundwater and ground pollution caused by leaching, furthermore, it has advantages like long/short term waterproofing, strength and durability. Therefore the SSG method can be applicable in the fields as an alternative method where is the problems of existing chemical grouting method.
        3,000원
        160.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Stress on plates may increase in the neighborhood the edges or the holes for rivets or bolts. Excessive stress concentration may lead to severe breakage of the plates. Thus, it is important to conduct optimization of arrangement of holes at the design stage. In this paper, accuracy of FEM analysis was examined for such stress concentration . By changing the hole size on a narrow plate, change of the stress concentration factor(K) was investigated. Additionally, the same experiment was conducted about series of multiple holes on plate to investigate interaction between the adjacent holes. Then, the FEM results were compared to the reference predictions respectively. Finally, a method by which simple stress concentrating situations can be optimized, will be suggested. This method was examined by FEM, and showed similar tendency with the expectation. Therefore, this method can be valuable when arranging the holes on a plate.
        4,000원