• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.9
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• pp.2800-2811
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• 1996

The deformation of a structure shall be called homologous, if a given geometrical relation holds, for a given number of structural points, before, during, and after the deformation. Some researchers have utilized the idea on structural design with finite element method. The approaches use the decomposition of the FEM equation or equality of eqality equations to obtain homologous deformation. However, weight reduction and response constraints such as stress, displacement or natural frequency cannot be considered by those theories. An optimization method solving the above problems is suggested to gain homologous deformation. Homology constraints can be considered under multiple loadindg conditions as well as a single loading condition. Homology index is defined for the multiple loading conditions Examples are solved to present the performances of the method.

• Journal for History of Mathematics
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• v.17 no.4
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• pp.37-44
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• 2004

Homological algebra has emerged and developed since 1950s. However, in 1890's Hilbert investigated the resolutions in his Syzygy Theorem which is a vital ingredient in homological algebra. In 1956 Serre has proved the finite global dimension of regular local rings. His result give a basic tool in homological algebra. This paper also deals with the depth formula that was raised by Auslander in 1961.

• Journal for History of Mathematics
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• v.20 no.4
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• pp.85-92
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• 2007

In this paper We study Some history and development of Geometry from the early 19th century to the late 20th century.

• Communications of the Korean Mathematical Society
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• v.15 no.2
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• pp.233-255
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• 2000

이 논문에서 계치부분군의 일반화와 이들을 이용한 G-열의 도입과정을 다룬다. 계치부분군과 일반화된 계치부분군 그리고 호모토피군의 차이를 설명하여 몇가지 공간의 계치부분군을 계산한다. 그리고 G-열이 완전열이 되기 위한 조건들을 조사하고 이 완전성을 이용하여 계치부분군의 계산과 함수의 단사성과 그 함수의 G-열의 완전성과의 상호 관련성을 보인다. 마지막으로 G-열의 일반화와 쌍대 G-열의 다룬다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.9
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• pp.1060-1069
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• 2019

Pedestrian-based camera self-calibration methods are suitable for video surveillance systems since they do not require complex calibration devices or procedures. However, using arbitrary pedestrians as calibration targets may result in poor calibration accuracy due to the unknown height of each pedestrian. To solve this problem in the real surveillance environments, this paper proposes a novel Bayesian approach. By assuming known statistics on the height of pedestrians, we construct a probabilistic model that takes into account uncertainties in both the foot/head locations and the pedestrian heights, using foot-head homology. Since solving the model directly is infeasible, we use variational Bayesian inference, an approximate inference algorithm. Accordingly, this makes it possible to estimate the height of pedestrians and to obtain accurate camera parameters simultaneously. Experimental results show that the proposed algorithm is robust to noise and provides accurate confidence in the calibration.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.3
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• pp.872-881
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• 1996

The concept of homology design has been devised for the application to large telescope structure by S.v.Hoerner. It is defined that the deformation of a structure shall be called homologous, if a given geometrical relation holds, for a given number of structural points, before, during, and after the deformation. Recently, the need of homology design in the structural design has been increase due to the required precision in the structure. Some researchers have utilized the theory on the structural design with finite element method in the late 1980s In the present investigation, a simple method using geometrical equality constraints is suggested to gain homologous deformation. The previous method is improved in that the decomposition of FEM eqation, which is very expensive, is not necessary. The basic formulations of the homology design with the optimization concept are described and several practical examples are solved to verify the usefulness and validity. Especially, a back-up structure of a satellite antenna is designed by the suggested method. The results are compared with those of existing researches.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.1
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• pp.223-229
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• 2018

This paper proposes a robust technique of image segmentation, which can be obtained if the topological persistence of each connected component is used as the feature vector for the graph-based image segmentation. The topological persistence of the components, which are obtained from the super-level set of the image, is computed from the morse function which is associated with the gray-level or color value of each pixel of the image. The procedure for the components to be born and be merged with the other components is presented in terms of zero-dimensional homology group. Extensive experiments are conducted with a variety of images to show the more correct image segmentation can be obtained by merging the components of small persistence into the adjacent components of large persistence.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.828-835
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• 2006

Spacer grid springs support the fuel rods in a nuclear fuel system. The spacer grid is a part of a fuel assembly. Since a spring has repeated contacts with the fuel rod, fretting wear occurs on the surface of the spring. Design is usually performed to reduce the wear. The conceptual design process for the spring is defined by using the Independence of axiomatic design and the design is carried out based on the direction that the design matrix indicates. For detailed design an optimization problem is formulated. In optimization, homologous design is employed to reduce fretting wear. The deformation of a structure is called homologous if a given geometrical relationship holds for a given number of structural points before, during, and after the deformation. In this case, the deformed shape of the spring should be the same as that of the fuel rod. 1bis condition is transformed to a function and considered as a constraint in the optimization process. The objective function is minimizing the maximum stress to allow a local plastic deformation. Optimization results show that the contact occurs in a wide range. Also, the results are verified by nonlinear finite element analysis.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.177-183
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• 2015

$\text\tiny{D}$-Psicose 3-Epimerase (DPE)는 $\text\tiny{D}$-Fructose의 C3 Epimerase로써 $\text\tiny{D}$-Fructose를 $\text\tiny{D}$-Psicose로 전환해 주는 효소이다. $\text\tiny{D}$-Psicose는 설탕 대신 사용하는 감미료로 몸에 흡수되지 않아 칼로리가 없다고 알려져 있고 자연에서는 오로지 DPE에 의해서만 생산되는 희귀당이다. 이에 따라 DPE를 통한 $\text\tiny{D}$-Psicose 대량생산의 필요성이 대두되고 있는 등 이 분야에 대한 관심이 뜨거운 실정이다. 본 연구팀은 이 당과 관련된 작용기작 연구를 수행하기 위하여 아직 단백질 3차구조가 알려지지 않은 Clostridium hylemonae DPE (chDPE) 단백질의 3차 구조예측 연구를 수행 하였다. 우리는 HHsearch를 이용하여 agrobacterium tumefaciens의 DPE 외 2개의 구조를 호몰로지 모델링 연구를 위한 주형으로 선정하였다. 다음으로 PROMALS3D를 이용하여 주형들과 chDPE의 multiple sequence alignment를 수행하였고 이를 바탕으로 3차구조 예측 연구를 수행 하였다. 예측된 구조를 검증하기 위하여 ProSA와 Ramachandran plot분석을 이용하였고 Ramachandran plot에서 단백질의 94.8%에 해당하는 잔기들이 favoured regions에 위치하였다. ProSA에서는 Z-score값이 -9.3으로 X-선 결정학이나 핵자기 공명법으로 밝혀진 구조들에서 관측되는 범위 내에 위치하였다. 나아가 예측된 구조에 $\text\tiny{D}$-Psicose와 $\text\tiny{D}$-Fructose의 결합모드를 규명하기 위하여 도킹을 시도하였다. 이번 연구를 통하여 chDPE의 구조를 예측 할 수 있었고 이를 바탕으로 이 단백질의 기능을 이해하는데 도움을 줄 것으로 기대된다.

• Computational Structural Engineering
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• v.11 no.1
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• pp.217-226
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• 1998

The purpose of this study is to develop a technique for the shape analysis of plane truss structures under prescribed displacement modes. The shape analysis is performed based on the existence theorem of the solution and the Moore-Penrose generalized inverse matrix. In this paper, the homologous deformation of structures was proposed as prescribed displacement modes, the shape of the structure is determined from these various modes and applied loads. In general, the shape analysis is a kind of inverse problem different from stress analysis, and the governing equation becomes nonlinear. In this regard, Newton-Raphson method was used to solve the nonlinear equation. Three different shape models are investigated as numerical examples to show the accuracy and the effectiveness of the proposed method.