• 대한조선학회논문집
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• 제31권4호
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• pp.109-118
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• 1994

본 연구에서는 쌍동형 표면효과선 선체 구조의 최소 중량 설계를 수행하는 방법을 제시하고, 이에 따르는 전산 프로그램을 개발하고자 한다. 본 방법은 DnV의 설계 하중 및 강도 기준을 이용하며, 격자 구조 해석을 통해 종거어더와 횡늑골의 상호 영향을 반영하여 설계에 활용하고, 쌍동 선체 사이의 연결 구조에 대해 비틂 강도 해석을 수행하여 횡격벽 설계를 수행한다. 또한 부분구조의 최적화를 통해 중앙 단면 전체의 최적화에 도달하는 방법을 적용함으로써 최적화의 효율을 증가시키고 있다. 본 방법을 적용한 결과, 초기 설계 결과에 비해 20% 정도의 선체 중량 감소효과를 확인할 수 있고, 최적의 횡늑골 간격도 계산될 수 있다.

• Structural Engineering and Mechanics
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• 제68권5호
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• pp.591-601
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• 2018

Non-moment beam-to-column connections, which are usually referred to as simple or shear connections, are typically designed to carry only gravity loads in the form of vertical shears. Although in the analysis of structures these connections are usually assumed to be pinned, they may provide a small amount of rotational stiffness due to the typical connection details. This paper investigates the effects of this small rotational restraint of simple beam-to-column connections on the behavior and seismic response of steel braced non-moment resisting frames. Two types of commonly used simple connections with bolted angles, i.e., the Double Web angle Connection (DWC) and Unstiffened Seat angle Connection (USC) are considered for this purpose. In addition to the pinned condition - as a simplified representation of these connections - more accurate semi-rigid models are established and then applied to some frame models subjected to nonlinear pushover and nonlinear time history analyses. Although the use of bracing elements generally reduces the sensitivity of the global structural response to the behavior of connections, the obtained results indicate considerable effects on the local responses. Namely, our results show that consideration of the real behavior of connections is essential in designing the column elements where the pin-connection assumption significantly underestimates design of outer columns of upper stories.

• Nuclear Engineering and Technology
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• 제51권4호
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• pp.1024-1031
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• 2019

The Molten Salt Fast Reactor (MSFR) with its liquid circulating fuel and its fast neutron spectrum calls for a new safety approach including technological neutral methodologies and analysis tools adapted to early design phases. In the frame of the Horizon2020 program SAMOFAR (Safety Assessment of the Molten Salt Fast Reactor) a safety approach suitable for Molten Salt Reactors is being developed and applied to the MSFR. After a description of the MSFR reference design, this paper focuses on the identification of the Postulated Initiating Events (PIEs), which is a core part of the global assessment methodology. To fulfil this task, the Functional Failure Mode and Effect Analysis (FFMEA) and the Master Logic Diagram (MLD) are selected and employed separately in order to be as exhaustive as possible in the identification of the initiating events of the system. Finally, an extract of the list of PIEs, selected as the most representative events resulting from the implementation of both methods, is presented to illustrate the methodology and some of the outcomes of the methods are compared in order to highlight symbioses and differences between the MLD and the FFMEA.

• 한국지진공학회논문집
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• 제23권5호
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• pp.279-288
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• 2019

Safety-related cabinets and their electrical parts, such as relays and switches in nuclear power plants, should maintain continuous functioning, as well as structural safety according to the nuclear regulatory guidelines. Generally, an electrical part is qualified if its functioning is maintained without abnormality during excitement by motion compatible with the test response spectrum, which is larger than its in-cabinet response spectrum (ICRS). ICRS can be determined by shake-table test or dynamic analysis. Since existing cabinets in use can hardly be stopped and moved, dynamic analysis is preferred over shake-table test in determining ICRS. The simple method, suggested by the Electric Power Research Institute (EPRI) to determine ICRS, yields conservative or non-conservative results from time to time. In order to determine that the ICRS is better than EPRI method in a simple way, Ritz method considering global and local plate behaviors was suggested by Gupta et al. In this paper, the Ritz method is modified in order to consider the rocking and frame behaviors simultaneously, and it is applied to a simple numerical example for verification. ICRS is determined by Ritz method and compared with the results by finite element method (FEM). Based on this numerical example, recommendations for using Ritz method are suggested.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2015년도 학술발표회
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• pp.216-216
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• 2015

Frequent hydro-meteorological events caused by global climate change and human exacerbate activities, make the water resource problem more complicated. The increasing speed urbanization brings a significant impact on the city flood control and security, water supply safety, water ecological security, water environment safety and the water engineering security in China, and puts forward higher requirements to urban water integrated management, undoubtedly which become the biggest obstacle for water ecological civilization construction, thus urgent requiring an advanced methods to enhance the effectiveness of the water integrated management. The other fields of smart ideas point out a development path for water resource development. The construction demand of smart water resource is expounded in the paper, combining the philosophy of modern Internet of things with the application of cloud computing technology. The concept of smart water resource is analyzed, the connotation characteristics of smart water resource is extracted, and the general model of smart water resource is refined. Then, the frame structure of smart water resource is put forward. The connotation and the overall framework of the smart water resource represent a higher level of water resource informationization development and provide a comprehensive scientific and technological support to transform water resource management from an extensive, passive, static, branch and traditional management to a fine, active, dynamic, collaborative and modern management.

• Steel and Composite Structures
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• 제38권4호
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• pp.381-397
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• 2021

Based on the spatial substructure hybrid simulation test (SHST) method, the seismic performance of a high-strength steel composite K-eccentrically braced frame (K-HSS-EBF) structure system is studied. First, on the basis of the existing pseudostatic experiments, a numerical model corresponding to the experimental model was established using OpenSees, which mainly simulated the shear effect of the shear links. A three-story and five-span spatial K-HSS-EBF was taken as the prototype, and SHST was performed with a half-scale SHST model. According to the test results, the validity of the SHST model was verified, and the main seismic performance indexes of the experimental substructure under different seismic waves were studied. The results show that the hybrid simulation results are basically consistent with the numerical simulation results of the global structure. The deformation of each story is mainly concentrated in the web of the shear link owing to shear deformation. The maximum interstory drifts of the model structure during Strength Level Earthquake (SLE) and Maximum Considered Earthquake (MCE) meet the demands of interstory limitations in the Chinese seismic design code of buildings. In conclusion, the seismic response characteristics of the K-HSS-EBFs are successfully simulated using the spatial SHST, which shows that the K-HSS-EBFs have good seismic performance.

• Journal of the Korean Wood Science and Technology
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• 제50권3호
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• pp.159-166
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• 2022

CO₂ emissions are the primary reason for global warming; hence, biological and chemical technologies for converting CO₂ into useful compounds are being actively studied. Biological methods using enzymes can convert CO₂ under mild conditions. Formate dehydrogenase (FDH) is a representative CO₂ conversion enzyme. Its function was revealed after isolation from bacteria, yeast, and plants. In this study, we evaluated the CO₂ conversion potential of FDH isolated from wood-rotting fungi. After isolating the FDH gene (TvFDH) from Trametes versicolor, we cloned the full-length FDH from T. versicolor and expressed it in a cell-free expression system. The gene encoding TvFDH was identified as 1,200 bp open reading frame (ORF) and the expected molecular weight of the protein was approximately 42 kDa. Overexpression of the recombinant crude protein including TvFDH was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Enzyme activities and metabolite analyses confirmed the efficiency of TvFDH for CO₂ reduction.

• Current Optics and Photonics
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• 제7권4호
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• pp.408-418
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• 2023

Due to the technological limitations of infrared thermography, infrared focal plane array (IFPA) imaging exhibits stripe non-uniformity, which is typically fixed pattern noise that changes over time and temperature on top of existing non-uniformities. This paper proposes a stripe non-uniformity correction algorithm based on scene-adaptive nonlinear filtering. The algorithm first uses a nonlinear filter to remove single-column non-uniformities and calculates the actual residual with respect to the original image. Then, the current residual is obtained by using the predicted residual from the previous frame and the actual residual. Finally, we adaptively calculate the gain and bias coefficients according to global motion parameters to reduce artifacts. Experimental results show that the proposed algorithm protects image edges to a certain extent, converges fast, has high quality, and effectively removes column stripes and non-uniform random noise compared to other adaptive correction algorithms.

• 통상정보연구
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• 제14권1호
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• pp.171-195
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• 2012

본 논문은 한중 양국의 FDI 관련 현황과 정책적 강약점을 파악하고 이를 통해 중국자본 유치전략에서 요구되는 기본적 전제조건을 검토함으로써 향후 중국자본 유치에 도움이 되는 정책방향을 모색하는 데에 연구목적을 둔다. 연구결과 도출된 주요 전제조건들을 제시하면 다음과 같다. 첫째, 한중간 경제관계는 상호보완적이고도 협력적인 수준에 크게 미흡한 상태이므로 무조건적 경쟁관계로 발전할 수 있는 위협요인들을 미리 제거하고, 양국간 신뢰관계를 확대해 나가야 한다. 둘째, 적어도 중국의 입장에서 보면 한국은 매력적인 투자처가 되지 못하고 있다. 최근 발효된 한미FTA 등 한국의 FTA 확대 기회를 적극 활용할 필요가 있다. 셋째, 한국을 대신하는 중국의 대체투자처는 항상 존재하고 있으므로, 투자종목이나 투자규모, 투자방식 등 중국자본 유치에 관련된 투자 협상력은 상당 부분 중국측이 가지고 있다는 사실을 간과하지 말아야 할 것이다. 넷째, 한국의 FDI 정책이 기존의 정책적 프레임 속에 갇혀 규칙 파괴자(rule breaker)의 기능을 발휘하지 못한다면 중국자본 유치는 노력에 비해 성과를 기대하기 어려울 것이다. 다섯째, 중국을 과대평가하거나 중국자본의 힘을 맹신하는 상황에서 중국자본 유치 노력을 경주하다가는 외형적 투자 또는 부실투자로 이어져 예기하지 못한 국가적 손실을 초래할 수 있다는 점에 유의해야 한다.

• 문화기술의 융합
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• 제6권2호
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• pp.327-331
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• 2020

본 연구는 위험의 대상과 성격이라는 점에서, 신흥안보는 전통적인 군사안보 이외에도 비군사적 영역, 즉 환경안보, 인간 안보, 자원안보, 사이버 안보 등을 포괄한다. 이러한 위험의 부상은 안보 영역이 새로이 확대되는 현상뿐만 아니라 안보 주체의 숫자와 범위의 확대 및 안보 세계정치의 양상을 변화시키고 있다. 이들 위험은 그 성격과 피해의 범위라는 점에서 지구적 차원에서 초국가적으로 발생하는 안보문제인 동시에 지역과 국가 차원의 국지적이고 개인적인 안보문제에도 영향을 미치는 다층적인 성격을 지니고 있다. 국가 행위자 이외에도 국제기구, 다국적 기업, 글로벌 시민사회 등과 같은 비(非)국가 행위자들, 그리고 더 나아가 기술 및 사회시스템 자체가 위험을 야기하는 원인이 되고 있다. 따라서 새로운 안보문제를 해결하기 위해서는 개별국가 차원을 넘어서 지역 및 글로벌 차원에서 모색되는 중층적이고 복합적인 거버넌스의 매커니즘을 마련하는 것이 필요하며, 이러한 변화는 기존의 인식 틀에서는 간과되었던 새로운 안보 이슈의 발생이라는 단편적 차원을 넘어서, 좀 더 넓은 의미에서 파악된 새로운 안보 패러다임을 분야별로 예측하고 대응방안을 모색하고자 한다.