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        검색결과 35

        1.
        2023.11 구독 인증기관·개인회원 무료
        Nuclear Material Accountancy (NMA) system quantitatively evaluates whether nuclear material is diverted or not. Material balance is evaluated based on nuclear material measurements based on this system and these processes are based on statistical techniques. Therefore, it is possible to evaluate the performance based on modeling and simulation technique from the development stage. In the performance evaluation, several diversion scenarios are established, nuclear material diversion is attempted in a virtual simulation environment according to these scenarios, and the detection probability is evaluated. Therefore, one of the important things is to derive vulnerable diversion scenario in advance. However, in actual facilities, it is not easy to manually derive weak scenario because there are numerous factors that affect detection performance. In this study, reinforcement learning has been applied to automatically derive vulnerable diversion scenarios from virtual NMA system. Reinforcement learning trains agents to take optimal actions in a virtual environment, and based on this, it is possible to develop an agent that attempt to divert nuclear materials according to optimal weak scenario in the NMA system. A somewhat simple NMA system model has been considered to confirm the applicability of reinforcement learning in this study. The simple model performs 10 consecutive material balance evaluations per year and has the characteristic of increasing MUF uncertainty according to balance period. The expected vulnerable diversion scenario is a case where the amount of diverted nuclear material increases in proportion to the size of the MUF uncertainty, and total amount of diverted nuclear material was assumed to be 8 kg, which corresponds to one significant quantity of plutonium. Virtual NMA system model (environment) and a divertor (agent) attempting to divert nuclear material were modeled to apply reinforcement learning. The agent is designed to receive a negative reward if an action attempting to divert is detected by the NMA system. Reinforcement learning automatically trains the agent to receive the maximum reward, and through this, the weakest diversion scenario can be derived. As a result of the study, it was confirmed that the agent was trained to attempt to divert nuclear material in a direction with a low detection probability in this system model. Through these results, it is found that it was possible to sufficiently derive weak scenarios based on reinforcement learning. This technique considered in this study can suggest methods to derive and supplement weak diversion scenarios in NMA system in advance. However, in order to apply this technology smoothly, there are still issues to be solved, and further research will be needed in the future.
        2.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 Aramid FRP와 모서리보강재로 구속한 엔지니어링플라스틱 보강을 통해 기둥의 횡구속 능력을 증대하여 콘크리트 피복 및 압괴 파괴를 지연시킴으로써 휨 항복 후 연성거동을 유도하여 기존 저층 필로티 건축물의 내진 성능을 확보하는 방법을 제시하고 저층 필로티 건축물의 내진취약요인을 분석하여 필요한 전단보강량을 산정, 제안공법의 목표전단보강을 설정하는 것을 목적으로 한다. 엔지니어링플라스틱을 활용한 기둥의 전단보강형상을 제안하고 필로티 구조의 내진취약요인 보강임계점 예측과 예제모델의 구조해석을 통해 제안공법의 목표전단보강량을 검증하였다. 구조해석 결과, 특별지진하중 적용 시, 휨-축력 내력 초과비율이 타 유형군에 비해 낮은 ST-A1(1축편심)을 기준으로 연면적 750m² 이하와 1축 편심 중심-강심편심율 18%이하에 해당될 경우에는 본 논문에서 제안하는 ‘고성능 복합섬유 패널 전단 보강법’을 적용할 수 있는 경계로 제한하고자 한다.
        4,300원
        9.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper has proposed a reinforcing method for damaged RC columns with SRF sheets and Aramid rods. In order to verify the effectiveness and performance, two original columns and two reinforced columns with SRF sheets and Aramid rods were developed and tested under lateral cyclic displacement and a constant axial load. The test showed that the improvement of energy dissipation capacity was increased in terms of strength and ductility. In addition, an analytical modeling of the standard specimens was proposed using Response-2000 and ZeusNL program. The results of analytical and experimental studies for two standard columns were compared in terms of loading-displacement curve and energy dissipation capacity based on the nonlinear static analysis.
        4,000원
        10.
        2014.04 구독 인증기관·개인회원 무료
        This paper experimentally investigates the seismic performance of RC columns retrofitted by Super Reinforcement with Flexibility (SRF). A total of three specimens with a scale factor of 1/2 were constructed and tested in order to assess the structural behavior of the retrofitted RC columns. One specimen was a non-seismically designed column without any retrofitting method while others were retrofitted with either one or two layers of SRF by using urethane adhesive. The static cyclic testing with a constant axial load was conducted to assess the seismic performance of the retrofitted RC columns. It is concluded that the SRF retrofitting method increases the strength and ductility of the RC columns and can also impact on the failure mode of the columns.
        11.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        King Seong carried out the large-scale construction transferring the capital from Wungjin (Gongju) to Sabi (Buyeo) in 538. But because most of the Buyeo area was the low swamp in the time, it needed above all to form a site before transferring the capital. Until recently, in addition to the scientific excavation, the relief excavations for the construction of new building or the formation of road were conducted on many sites in the Buyeo area. As a result, many remains which were formed on the low swamp including the temple site of Neungsan-ri, Dongna Castle, the remains of Ssangbuk-ri (280-5 Bukpo, Hyeonnaedeul) and the remains of Gua-ri were identified. Also in these remains, the various engineering construction methods irrespective of the nature of remains were used for the purpose of the soft ground reinforcement as follows: mattress method of construction, pile designation, stone alignment, filing of decomposed granite soil, culverts and storage tanks. Especially, the mattress method of construction and the pile designation are thought to be the traditional engineering construction method at least in that they are appeared since the Three Han Sates era. And these soft ground construction methods had an effect on the construction of reservoir in Japan at the time. In the future, the construction method for soft ground reinforcement shall be concerned and studied further in the architecture and the civil engineering as well as the archeology.
        5,100원
        13.
        2008.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The actual status of a single span vinyl-house for a institution vegetable cultivation in a main cultivation area was investigated to make good use of the data for developing a structural reinforcement method of single span vinyl-house. The structural stability of single span vinyl-house with a width of 6.0m and high of 3.0m utilized in that area was analyzed by using a three-dimensional visual FEA code. Finally, the optimized structural reinforcement method of pipes with a width of 6.0m which had a roof height of 3.0m was respectively presented. The results showed that the structural reinforcement method of the single span vinyl-house was classified as the model cases from a view point of structural stability. It was secured under the condition of a wind velocity of 40m/s and a snow-depth of 35~55cm, simultaneously.
        4,000원
        14.
        2019.07 KCI 등재 서비스 종료(열람 제한)
        본 연구는 공용 중 보강토옹벽에 발생하는 배부름현상을 보강하기 위한 방법을 제안하고 현장실험으로 보강방법의 신뢰성을 파악 하고자 하였다. 보강토옹벽의 배수시설을 미설치하여 강우에 의해 배부름현상이 유도되도록 하였으며, 시공 후 15일간 변위속도가 크게 발생한 후 점차적으로 감소하였다. 유도된 배부름현상의 변위는 미연방도로국(FHWA)의 시공 중 수평변위 기준을 적용하여 판단하였다. 배부름 현상을 보강하기 위해 보강토옹벽에 소일네일을 설치하고, 네일의 두부를 수평으로 서로 연결하여 보강토 옹벽의 블록들을 서로 지지할 수 있도록 하였다. 보강재들의 보호를 위해 숏크리트로 보강면을 마감하고 계측장치를 설치하였다. 배부름현상 보강방법의 신뢰성을 확인하기 위하여 변위의 진행을 검측한 결과 보강 후 수평변위는 거의 발생하지 않았으며, 보강방법의 신뢰성을 확인할 수 있었다.
        15.
        2019.04 서비스 종료(열람 제한)
        In this study, concrete box structure was analyzed for reinforcement of the corner using the proposed pre-flexed steel members, Numerical results confirmed that the proposed reinforcement method can enhance the load capacity of the concrete box structures.
        16.
        2017.06 KCI 등재 서비스 종료(열람 제한)
        도시브랜드를 강화하기 위해서는 도시슬로건 및 정책방향, 행정서비스, 공공디자인 등이 일관성을 가지고 추진되어야 한다. 그 중에서 정책과 디자인은 도시브랜드를 직접적으로, 그리고 가시적으로 드러낼 수 있는 수단으로 도시브랜드 강화방법이 다. 공공의 문제는 제도적인 장치를 통해 해결할 수 있는데 문제의 원인과 사회적 여건, 대상 등이 다양하여 다수의 이해관 계자가 다각적인 접근을 통해 문제의 실마리를 찾을 수 있다. 또한 여러 가지 상황들이 복합적으로 작용하기 때문에 그 문 제의 공간적, 인문적, 기능적 요인들에 대한 제도들이 상호 유기적으로 작용할 때 정책목표를 보다 효과적으로 달성할 수 있다. 따라서 사회문제를 해결하기 위한 공공정책은 다양한 영역에서 분야 간 융합을 시도하고 이를 통해 혁신적인 공공서 비스를 제시해야 할 시점이다. 보다 효율적인 정책목표 달성을 위한 정책과 디자인의 혁신적인 연계방안에 대하여 다음과 같이 제언한다. 첫째, 사회문제 해결은 공공정책의 주요한 의제로서 다수의 행정기구 간 협업이 요구된다. 둘째, 사회문제 해결을 위한 정책과 디자인의 실행연계를 위해서는 정책관리자가 필요하다. 셋째, 동일한 목표달성을 위한 사업계획의 이 행에 있어서 다수의 분야 혹은 담당자의 상시적인 소통이 이루어질 수 있도록 관계망을 형성하려는 노력이 필요하다. 넷째, 사회문제 해결을 위한 정책을 효과적으로 실행하기 위해서는 정보의 공유 및 참여확대를 통한 홍보가 필요하다.
        17.
        2017.05 KCI 등재 서비스 종료(열람 제한)
        1980년대에서 1990년대 중반까지 건설된 노후 공동주택 단지의 주차장 부족 현상은 심각하다. 노후 공동주택의 주차장 확대 사례 를 살펴보면 수직으로 지하 주차장을 확장하는 방식이 대부분을 차지하고 있다. 기존 건축물을 증축할 경우 기초의 구조적 안전성 확보는 매우 중요하며, 지하 수직방향 공사의 경우 작업 공간이 협소하기 때문에 안전성, 환경성 및 시공성이 우수한 공법을 적용해야 한다. 도심지 공사는 소음과 진동이 작은 공법과 장비의 사용도 필수적이다. 이 연구는 지하주차장 확대 공사에 필요한 기초보강 공법 선정에 영향을 미치는 요인을 분석하고 영향요인의 가중치를 산정하여 기초보강공법의 적용성을 분석 할 목적으로 수행되었다. 기초보강 공법의 적용성에 영향을 미치는 요인은 전문가 면담조사를 통하여 도출하였고, AHP기법을 통하여 영향요인의 가중치를 산정하였다. 전문가를 대상으로 기초보강 공법의 적 용성을 평가 하였다. 2건의 지하주차장 확대 유형에 대한 사례연구를 실시하여 기초보강공법의 적용성을 비교 분석하였다.
        18.
        2017.04 서비스 종료(열람 제한)
        The internal displacement of the corrugated steel plate structure reduces structural stability. In this study, we evaluated the stability of the corrugated steel plate culvert structure using an inspecting deformation rates between designs and measured 3D shapes. Also, a proper repair and reinforcement method will be proposed through analytical and experimental verification
        19.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        In this study, It was purpose to provide preliminary data for extension of the applicability of deep corrugated steel plate composite members by steel grade and shear reinforcement method. From the result of flexural test on deep corrugated plates composite members using GR40 and SS590, positive moment capacity was increased about 28% by SS590 steel. But to change steel grade was proved to have insignificant effects for increasement of negative moment capacity. In the moment test result of same overlapping length, Increasement rate of positive and negative moment capacity was not significantly improved by increasing the number of bolt. It was estimated to be due to the characteristics of bolt connection such as distance between centers of bolts, edge distance of bolt. In the test result on the spacing of shear reinforcement, positive moment capacity was increased and deformation of negative moment was reduced as the distance decrease. In the test result on the shape of shear reinforcement, positive and negative moment resistance was increased about 2% ~ 7% by U shaped shear reinforcement. In conclusion It was estimated that moment capacity of deep corrugated steel plate composite members are depend on steel grade of deep corrugated steel plate, spacing of shear reinforcement and reinforcing bar.
        20.
        2017.01 KCI 등재 서비스 종료(열람 제한)
        The internal displacement of the corrugated steel plate structure reduces structural stability. In this study, we evaluated the stability of the corrugated steel plate culvert structure using an inspecting deformation rates between designs and measured 3D shapes. Also, a proper repair and reinforcement method will be proposed through analytical and experimental verification.
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