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        검색결과 6,504

        4781.
        2019.04 서비스 종료(열람 제한)
        Occurring economic loss of economics by the earthquake, such as Gyeongju and Pohang in Korea, interest in seismic stability of facilities is increasing. Electrical Cabinet Structure in Power Plant should be prepared for malfunctions and its structural safety should be ensured as well an earthquake event. The purpose of this investigation is to increase the seismic stability of the cabinet. Through finite elements analysis, dynamic characteristics of the cabinet were identified herein, and time history analysis was performed by converting the design response spectra. In order to improve safety against earthquakes, a variable analysis was conducted to utilize steel dampers for seismic retrofit of the cabinet, and time history analysis results compared with the response of basic and seismic retrofitted cabinets.
        4782.
        2019.04 서비스 종료(열람 제한)
        The seismic performance evaluation of domestic thermal power generation facilities is not significant compared to its importance. Therefore, in this study, seismic performance evaluation of the chimney structure responsible for the exhaust function in the thermal power plant was performed using Abaqus, a finite element analysis program. As a result, we could obtain the flexural strength curves of concrete compressive failure and relative displacement of stack.
        4783.
        2019.04 서비스 종료(열람 제한)
        Thermal power generation was a very important power source in Korea. Therefore improvement of seismic reliability of the thermal power plants is required, because occurrence of very large earthquakes is expected in Korea. Especially, after the earthquake in Gyeong-ju and Po-hang, seismic waves are recognized as a new problem in Korea. In this study, numerical analysis was carried out in order to investigate behavior of the boiler structure in the thermal power plant under earthquakes. The effect of the developed hybrid damper is analytically confirmed.
        4784.
        2019.04 서비스 종료(열람 제한)
        Recently many investigations have been conducted to evaluate and analyze the seismic response of structures equipped different types of damper. Viscous dampers are known as effective energy dissipation devices improving structural response to earthquakes. The damping force developed by the viscous damper depends on internal structural system and the physical properties of the fluid used in the device. This study has developed a viscous damper for vibration and seismic control of structures. In order to verify the performance of a viscous damper, experimental tests were performed.
        4785.
        2019.04 서비스 종료(열람 제한)
        Friction dampers are categorized as displacement-dependent energy dissipation devices, because their damper force is independent from frequency and velocity. They have found large practical application in seismic retrofitting of existing structures due to their low cost and simple installation. A typical friction damper consists of series of steel plates tighten together with high durability steel bolts in order to achieve more reliable friction through the interfaces. This study developed a multi-friction damper by laminating friction materials. In order to verify the performance of the multi-friction dampers, experimental tests were performed.
        4786.
        2019.04 서비스 종료(열람 제한)
        In thermal power plant, steam is made by boiler. As it rotates turbine, electric power is generated. Thermal power plant has a high-rise structure that has a boiler and other equipment. Thermal expansion of the boiler is large because combustion temperature is high. The boiler vibrates easily because it is suspended from the top of the support structure in order not to restrict deformation by thermal expansion. Thus, the boiler structure supported by the hanger is very vulnerable to earthquakes. In this study, numerical analysis was carried out in order to investigate behavior of the boiler structure in the thermal power plant under earthquakes.
        4787.
        2019.04 서비스 종료(열람 제한)
        In this study, structural tests were performed for the para-aramid fiber-reinforced RC beams using Recycled Coarse Aggregates (RCA) according to the main parameters which are RCA replacement ratio (0 and 30%) and para-aramid fiber volume fraction (0, 0.75 and 1.0%). Experimental results show that by reinforcing para-aramid fibers, compared with the natural coarse aggregate, the RCA, which exhibited low structural performance, improved load carrying capacity and ductility.
        4788.
        2019.04 서비스 종료(열람 제한)
        The purpose of this study is to understand the structural performance of the specimens beam by changing the depth and width of the U-shaped composite beam. To this end, experimental specimens by changing depth and width as compared with a reference specimen were prepared and tested. As a result of this study, growth of the depth has great effect on the structural performance while a width increase has no significant effect on the structural performance of composite beam.
        4789.
        2019.04 서비스 종료(열람 제한)
        This research provides a method that can be conveniently and easily to apply the prestressing force to concrete structures incorporating shape memory alloy fibers. For this, discrete shape memory alloy fibers were manufactured to be mixed with cement mortar. Then shape memory effect was generated to evaluate uplift displacements at the mid-span of the mortar beams with increasing fiber volume fractions.
        4790.
        2019.04 서비스 종료(열람 제한)
        In order to improve the traffic congestion on the road, it is essential to construct overpasses and highways in big cities. In particular, in order to facilitate traffic flow within the overpass route, it is necessary to construct a curved bridge because the plane shape of the bridge itself must be aligned with the road alignment. Therefore, in this study, we have developed a precast PSC curved girder of concrete hollow box type with excellent bending moment, shear force and torsional moment resistance, and perform performance evaluation by structural test to confirm applicability to curved bridge.
        4791.
        2019.04 서비스 종료(열람 제한)
        This research provides techniques for the implementation of an integrity evaluation system developed for wind turbine structures to jack-up barge. The strain values obtained from the upper tip of the footing are to be converted into values at a single point in order to represent the structural behavior. These obtained values are evaluated simultaneously through P-M curve, generated by FEM results. Evaluating loads with P-M curve, structural stability of barge could then be monitored.
        4792.
        2019.04 KCI 등재 서비스 종료(열람 제한)
        Purpose - This study attempted to construct and validate a structural model of the relationship between the quality of medical services, perceived risk, reputation and customer satisfaction, which is the main concept of the relationship between large hospitals as well as small and medium hospitals and medical consumers. Through this verification, the small and medium hospitals are to find the way for wise coping in competitive situation with large hospitals. Research design, data, and methodology - This research developed a hypothesis by constructing a structural equation that reaches the satisfaction and the relationship between reputation of perceived risk and perceived risk of service quality perceptions of customers of small and medium hospitals. Research data were collected through a questionnaire survey of respondents who had medical service experience from small and medium hospital. A total data of 252 respondents were used as the sample for the final analysis and analyzed using SPSS 23.0 and AMOS 23. Results - As a result, the relationship of quality of medical service, reputation, and customer satisfaction among small and medium hospitals was consistent with the results of precedent studies, and the perceived risk has a significant impact on reputation, so the greater the perceived risk, the higher the preference for reputable medical institutions as large hospitals. In addition, it was found that the direct route from perceived risk to customer satisfaction was not significant, and reputation was found to have a full mediating effect on perceived risk and customer satisfaction. Customers who use small and medium hospitals prefer to use reputable medical institutions if their perceived risk is high, which is different from risk perception when specific targets are specified. Conclusions - In terms of the effect from customer satisfaction, not only the path of perceived risk → reputation → customer satisfaction, but also the quality of service quality → reputation → customer satisfaction. These findings suggest that small and medium hospitals are appropriately responding to competition with large hospitals, rather than focusing on the perceived risks and reputation of customers in establishing and utilizing competitive strategies to create new customers and preserve existing customers
        4794.
        2019.03 KCI 등재 서비스 종료(열람 제한)
        잔교식 안벽의 수중부는 접근이 쉽지 않아서 손상확인이 어려운 곳인데, 최근들어 태풍과 지진이 빈번하게 발생하고 있어 잔교식안벽 수중부 구조물의 손상 누적으로 인한 붕괴가 우려되는 상황이다. 잔교식 안벽의 붕괴를 방지하고 체계적으로 유지관리하기 위한 방안으로 FBG 센서를 이용한 적용 방법과 안전성 평가 방법을 연구하였다. 잔교식 안벽에 파일로 사용되는 원형 강관에 대한 FBG 센서의 적용 방안을 확인하기 위해 실내실험을 실시하고, 센서를 용접하여 부착하는 방법으로 적용해야 하는 것을 확인하였다. 잔교식 안벽에 대한 구조해석을 수행하여 FBG 센서를 부착하기 위한 최적의 부착위치를 확인하였다. 고정하중에 대한 응력을 구조해석을 하여 계산하고, FBG 센서를 통해 얻은 데이터를 이용하여 활하중에 대한 응력을 계산한 다음에 두 응력을 더해서 파일에 작용하고 있는 응력을 계산하였다. 계산한 응력을 허용응력과 비교하여 파일의 안전성 평가를 수행하였다. 본 연구는 잔교식 안벽의 안전성을 실시간으로 평가하는 방안을 찾기 위한 기초 연구로 수행되었다.
        4795.
        2019.03 KCI 등재 서비스 종료(열람 제한)
        Morphosyntactic and prosodic information is accessed by native speakers of North Gyeongsang Korean when interrogatives are interpreted. The present study investigates the interface between these structures. To do so, the study analyzes the syntactic and prosodic structures of the dialect’s yes/no and wh-questions, and then examines the rate of comprehension and acceptance of the two types of the interrogatives in a perception test. The prosodic structures in the test are modified by transplantation, the results of which allow us to find out the following. First, presented with the interrogatives whose syntactic and prosodic structures did not match, the native subjects of Gyeongsang Korean relied more on the prosodic structures than on the syntactic ones. Second, changes in prosodic structures had a strong influence on simple sentences, but relatively less so on complex sentences. These results lead to the conclusion that prosodic structures are the decisive factor in syntactic interpretations, and, accordingly, are intricately intertwined with the syntactic structures during the processing of interrogatives.
        4798.
        2019.02 KCI 등재 서비스 종료(열람 제한)
        목적: 본 연구에서는 자기결정성 이론에 근거하여 케어링이 기본심리욕구를 매개로 운동지속에 미치는 과정을 살펴보았다. 방법: 피트니스센터 참여자 297명을 대상으로 위계적 다중회귀분석을 통해서 연구모형을 검증하였고, 간접효과의 유의성은 부트스트랩핑 방법을 통해 실시하였다. 결과: 연구모형에 대한 간접효과를 살펴본 결과 케어링 → 자율성 → 경향성, 케어링 → 자율성 → 강화성, 케어링 → 유능성 → 가능성, 케어링 → 관계성 → 강화 성에서 통계적으로 유의성이 존재하였으므로 케어링은 기본심리욕구를 매개로 운동지속을 강화시키는 것으로 나타났다. 결론: 본 연구를 통해 케어링이 운동지속에 미치는 심리적 변화과정이 기본심리욕구를 매개로 이루어짐 을 알 수 있었다. 이런 결과는 지도자를 위한 효율적인 케어링 지도법 개발 시 기본심리욕구 향상을 위한 전략을 중심으로 이루어져야 함을 의미한다.
        4799.
        2018.12 KCI 등재 서비스 종료(열람 제한)
        본 논문에서는 긴 파이프 이뤄진 세장형 부이 구조물의 파랑 중 거동특성에 관한 모형시험과 수치해석 연구를 수행하였다. 대상 부이 구조물은 긴 파이프를 기본 뼈대로 하여, 상부구조물, 부력재, 중력식 앵커로 구성된 아티큘레이트(Articulated)형 부이 구조물이다. 대상 해역인 서해에서의 본 부이 구조물의 생존성을 평가하기 위하여, 축척비 1/22의 축소 모형을 제작하여 선박해양플랜트연구소 해양공학수조에서 일련의 모형시험을 진행하였다. 이 때 50년 재현주기의 극한파 조건을 고려하였으며, 또한 조류 및 주기 효과를 검토하기 위하여 추가적인 실험을 수행하였다. 생존성 평가를 위한 주된 평가항목으로는 구조물의 거동, 앵커 지지력, 침수 횟수를 고려하였다. 모형시험 결과와의 상호검증을 수행하기 위하여 상용계류해석 프로그램인 OrcaFlex를 이용하여 수치 시뮬레이션을 병행하였다. 평가결과로써 먼저 조위차에 따른 본 부이 구조물의 거동 특성에 대해 살펴보았다. 고조위와 저조위 조건에서의 종동요 응답, 앵커지지력의 변화를 살펴보았으며, 수치 시뮬레이션 결과와의 직접 비교 검토하였다. 두 번째로는 파도 주기와 조류의 유무에 따른 부이 구조물의 응답 특성 변화에 대해 고찰하였다. 세 번째로는 상부구조물의 침수와 관련하여 비디오 분석을 통한 침수 횟수를 수치해석 결과와 비교 제시하였다. 마지막으로 모형시험에서 직접 계측하지 못한 구조응답과 관련하여 수치 시뮬레이션 결과를 제시하고, 극한파 중 구조적 안전성에 대해서 논하였다. 일련의 생존성 평가 연구를 통하여 본 부이 구조물의 극한파 중 거동 특성에 대해 살펴볼 수 있었으며, 파도, 조류, 조위차에 따른 민감도 특성을 통해 본 부이구조물의 취약점 및 활용성에 대해 고찰해 보고자 하였다.
        4800.
        2018.12 KCI 등재 서비스 종료(열람 제한)
        This paper deals with the paddle type end of arm tool for rescue robot instead of rescue worker in dangerous environments such as fire, earthquake, national disaster and defense. It is equipped at the dual arm manipulator of the rescue robot to safely lift up an injured person. It consists of the paddle for lifting person, sensors for detecting insertion of person onto the paddle, sensor for measuring the tilting angle of the paddle, and mechanical compliance part for preventing incidental injuries. The electronics is comprised of the DAQ module to acquire the sensors data, the control module to treat the sensors data and to manage the errors, and the communication module to transmit the sensors data. After optimally designing the mechanical and electronical parts, we successfully made the paddle type end of arm tool and evaluated its performance by using specially designed jigs. The developed paddle type end of arm tool is going to be applied to the rescue robot for performance verification through field testing.