• 산업기술연구
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• 제17권
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• pp.305-312
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• 1997

Shear connections in steel structures should satisfy dual criteria of shear strength and rotational flexibility and ductility. The connection should be strong enough to transfer the shear reaction of the beam, and should have sufficient rotational flexibility and ductility to rotate easily and supply the end rotation demand of the beam. This paper is concerned with the behavior of double-angle shear connections where the parameters are numbers of high strength bolts, bolt pitch, the length of angle leg, and connection method. An experimental investigation of shear connection was conducted by testing 12 beam-to-column joint specimens. Based on experimental and analytical study, the failure modes are developed and proposed design formulas.

• 한국통신학회논문지
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• 제30권5B호
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• pp.287-294
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• 2005

현재 Internet Protocol Version 4(IPv4) 기반의 인터넷을 한 순간에 Internet Protocol Version 6(IPv6)로 전환하는 것은 불가능하며, 전환 기간 동안에는 두 프로토콜이 공존할 것으로 예상된다. Internet Engineering Task Force(IETF)의 Next Generation Transition Working Group(Ngtrans WG)을 중심으로 많은 전환 메커니즘이 제안되었다. 그러나 대부분의 전환 메커니즘들은 IPv6 망에 있는 호스트로부터 IPv4 망에 있는 호스트로 연결을 설정하는 경우에만 연결을 지원하며, IPv4 망에 있는 호스트가 IPv6 망에 있는 호스트로 연결을 시도하는 경우에는 연결을 지원하지 못하는 문제점을 가지고 있다. 본 논문에서는 IPv4 망에 존재하는 IPv4 클라이언트가 IPv6 망에 존재하는 듀얼 스택 서버로 연결을 설정하고자 하는 경우에 IPv4 클라이언트와 IPv6 망 내의 듀얼 스택 서버 사이에 투명한 연결을 지원하는 IPv4-to-IPv6 듀얼 스택 전환 메커니즘(IPv4-to-IPv6 Dual Stack Transition Mechanism-4to6 DSTM)을 제안한다.

• 호남수학학술지
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• 제46권1호
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• pp.114-119
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• 2024

In this article, we consider a connection of vectorial type in some sense which is not a metric connection. We will then discuss when this connection $\tilde{\nabla}^*$ has parallel torsion T, that is, $\tilde{\nabla}^*T=0$.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1997년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Fall 1997
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• pp.173-181
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• 1997

To investigate the effects of haunch repair on the system seismic performance of steel moment-resisting frames (steel MRFs), a case study was conducted for a 13-story frame damaged during the 1994 Northridge earthquake. It was assumed that only those locations with reported damage would be repaired with haunches. A new analytical modeling technique for the dual panel zone developed by the author was incorporated in the analysis. Both the inelastic static and dynamic analyses did not indicate detrimental side effects resulting from the repair. As a result of the increased strength in dual panel zones, yielding in these locations were eliminated and larger plastic rotation demand occurred in the beams next to the shallow end of the haunches. Nevertheless, the beam plastic rotation demand produced by the Sylmar record of 1994 Northridge earthquake was still limited to 1.7% radians. The repair resulted in a minor increase in earthquake energy input. In the original structure, the panel zones should dissipate about 80%(for the Oxnard record) and 70%(for the Sylmar record) of the absorbed energy, assuming no brittle failure of moment connections. After repair, the energy dissipated in the panel zones and beams were about equal.

• 전자공학회논문지B
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• 제31B권12호
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• pp.124-131
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• 1994

In this paper, we propose a new approach of solving the stereopsis problem with a discrete-time cellular neural network(DTCNN) where each node has connections only with its local neithbors. Because the matching process of stereo correspondence depends on its geometrically local characteristics, the DTCNN is suitable for the stereo correspondence. Moreover, it can be easily implemented in VLSI. Therefore, we employed a two-layer DTCNN with dual templates, which are determined with the back propagation learning rule. Based on evaluation of the proposed approach for several random-dot stereograms, its performance is better than that of the Marr-Poggio algorithm.

• 호남수학학술지
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• 제46권2호
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• pp.224-236
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• 2024

This study inspects the structure of CR-product of a holomorphic statistical manifold. Findings concerning geodesic submanifolds and totally geodesic foliations in the context of dual connections have been demonstrated. The integrability of distributions in CR-statistical submanifolds has been characterized. The statistical version of CR-product in the holomorphic statistical manifold has been researched. Additionally, some assertions for curvature tensor field of the holomorphic statistical manifold have been substantiated.

• Steel and Composite Structures
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• 제36권2호
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• pp.213-228
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• 2020

Shape Memory Alloys (SMAs) are new materials used in various fields of science and engineering, one of which is civil engineering. Owing to their distinguished capabilities such as super elasticity, energy dissipation, and tolerating cyclic deformations, these materials have been of interest to engineers. On the other hand, the connections of a steel structure are of paramount importance because of their vulnerabilities during an earthquake. Therefore, it is indispensable to find approaches to augment the efficiency and safety of the connection. This research investigates the behavior of steel connections with extended end plates equipped hybridly with 8 rows of high strength bolts as well as Nitinol superelastic SMA bolts. The connections are studied using component method in dual form. In this method, the components affecting the connections behavior, such as beam flange, beam web, column web, extended end plate, and bolts are considered as parallel and series springs according to the Euro-Code3. Then, the nonlinear force- displacement response of the connection is presented in the form of moment-rotation curve. The results obtained from this survey demonstrate that the connection has ductility, in addition to its high strength, due to high ductility of SMA bolts.

• 대한전자공학회논문지TC
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• 제45권2호
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• pp.1-5
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• 2008

LDPC 구조는 1개의 개수가 적은 구조의 패리티 체크 행렬을 구성하여도, H행렬의 역행렬을 구하는 과정 중에 가우시안 소거법으로 인하여 H 행렬은 1의 개수가 적은 성질이 없어지고 계산량도 블록 크기 당 $n^2$의 계산량이 요구되어지고 있다. 그러므로 LDPC 패리티 체크 행려인 H는 좀 더 효율적인 부호화에 초점을 두고 개발되고 있다. 본 논문에서는 edge-by-edge 방법으로 체크 노드와 심볼 노드사이를 연결하거나 연결선을 정하는 것으로 큰 girth를 가지는 Tanner 그래프를 구성할 수 있는 PEG 알고리즘을 변형 시킨 M-PEG를 패리티 체크 행렬인 H를 구성하고 좀 더 효율적으로 부호화기를 구성할 수 있도록 dual-diagonal 형태를 지니는 H를 구성한다.

• Earthquakes and Structures
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• 제12권5호
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• pp.515-527
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• 2017

Recently, Friction dampers become popular due to the desirable performance in the energy dissipation of lateral loads. A lot of research which has been conducted on these dampers results in developing friction dampers with low sensitivity to the number of cycles and temperature increases. Friction dampers impose high residual drifts to the buildings because of low post-yield stiffness of the damper which results from increasing lateral displacement and period of buildings. This issue can be more critical under strong aftershocks which results in increasing of structural damages. In this paper, in addition to the assessment of aftershock on steel buildings equipped with friction dampers, methods for controlling residual drifts and decreasing the costs of retrofitting are investigated. Utilizing rigid connections as a lateral dual system and activating lateral stiffness of gravity columns by adding elastic braces are as an example of effective methods investigated in this research. The results of nonlinear time history analyses on the low to medium rise steel frames equipped with friction dampers illustrate a rise in residual drifts as the result of aftershocks. In addition, the results show that different slip loads of friction damper can affect the residual drifts. Furthermore, elastic stories in comparison to rigid connections can reduce residual drifts of buildings in an effective fashion, when most slip loads of friction dampers are considered.

• 한국지진공학회논문집
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• 제14권5호
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• pp.41-51
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• 2010

안전한 내진설계를 위해서는 부재에 요구되는 소성변형을 평가하여야 한다. 본 연구에서는 복잡한 비선형해석없이 탄성 해석결과에 근거하여 이중골조의 부재소성변형을 평가할 수 있는 빠르고 간편한 방법을 개발하였다. 보, 기둥, 벽체 등의 소성변형은 부재강성, 층간변위비, 모멘트 재분배, 단면치수 및 소성힌지 위치의 함수로 결정된다. 벽체와 보가 모멘트 접합된 경우에는 벽체의 소성변형에 의한 로킹효과를 고려하여 증가된 소성변형을 구한다. 8층 이중골조에 대하여 제안된 방법을 적용하였고, 비선형해석을 통하여 제안된 방법의 정확성을 검증하였다. 제안된 방법은 단순계산으로 부재소성변형을 합리적으로 예측하지만, 정확한 부재소성변형 평가를 위해서는 비탄성 층간변위비의 정확한 예측이 필요한 것으로 나타났다. 제안된 방법은 향후 성능중심 내진설계에 활용할 수 있을 뿐만 아니라 기존 건물의 성능평가에도 활용될 수 있을 것이다.