• Structural Engineering and Mechanics
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• 제15권5호
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• pp.579-608
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• 2003

This paper deals with adaptive finite element analysis of linearly elastic structures using different error estimators based on flux projection (or best guess stress values) and residual methods. Presentations are given on a typical h-type adaptive analysis, a mesh refinement scheme and the coupling of adaptive finite element analysis with automatic mesh generation. Details about different error estimators are provided and their performance, reliability and convergence are studied using six node quadratic triangular elements. Several examples are presented to demonstrate the reliability of different error estimators.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.155-156
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• 2023

In the case of steel door frames commonly found in general buildings, there are various assembly methods such as rivets, bolts, and welding, but the welding method is generally used. However, this welding joint method has many problems, such as distortion due to heat and damage due to external shock. In particular, when used as a fire door, problems may occur in the event of a fire due to distortion caused by heat from welding and the weak welded joint area. In the case of rivet or welded joints, when moved after assembly, joint loosening due to external shock may occur. Problems may arise where the bonding strength becomes weak. In addition, with the recent increase in high-rise buildings and larger buildings, when assembly is completed and brought to the site, a place is needed to store it, and in addition, there is a problem in that it has to be transported several times in small quantities to the installation site, which is another problem of time and cost loss. This is coming to the fore. In order to fundamentally solve this problem, we have researched and developed a non-welding door frame that can be assembled on site. We have researched and developed three assembly methods: screw-type, insert-type, and protrusion-type. Non-welded door frames are small in size and easy to package, making them advantageous for domestic and overseas exports.

• 한국전자파학회논문지
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• 제14권5호
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• pp.506-512
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• 2003

위성 중계기의 무게와 부피를 최소화 하기 위하여 출력 멀티플렉서는 매니폴드(manifold) 형태로 많이 설계한다. 매니폴드 형태의 출력 멀티플렉서의 정확한 성능을 구현하기 위해서는 이에 사용하는 각각의 채널 필터는 단일 종단으로 설계하여야 한다. 본 논문에서는 필터의 전달 함수로부터 orthogonal projection 및 행렬의 평면회전(plane rotation)을 이용하여 6차 단일종단 이중모드 필터의 회로망 파라미터인 입출력 저항 및 결합 행렬을 구할 수 있는 합성 방법에 대하여 설명하였다. 특히 평면 회전 과정에서의 회전 행렬의 피벗 및 회전각을 제시하여 구현 가능한 결합 계수를 용이하게 얻을 수 있도록 하였다. 두 개의 서로 다른 구조를 갖는 필터에 대하여 동일한 전달 함수로부터 각각의 회로망 파라미터를 추출하였다. 본 논문에서 서술한 단일종단 필터의 회로망 파라미터 추출법은 다른 차수의 필터에도 적용이 가능하다.

• 한국통신학회논문지
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• 제28권7A호
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• pp.557-562
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• 2003

An output multiplexer of manifold type is widely used in a recent satellite transponder for its mass and volume reduction. For correct operation, the filters of such a multiplexer must be singly terminated. In this paper, a simple synthesis method of a 6-pole dual-mode singly-terminated filter is described. From the transfer function of the filter, network parameters such as in/output terminations and coupling coefficients are obtained easily without complicated matrix algebra such as orthogonal projection and similarity transformation. Two different-structure filters are taken into consideration and the network parameters of each filter have been extracted from the same transfer function. It is shown that the responses of two filters are same to each other since their network parameters are obtained from the same transfer function. The method described in this paper can be applied to the other degree singly terminated filter.