• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.1
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• pp.29-34
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• 2001

구조물설계에 있어서 영향선은 최대반력, 최대전단력, 최대휨모멘트 등을 계산하는데 아주 유용하게 사용된다. 모멘트분배법, 인도행렬법, 전달행렬법, 그리고 Muller-Breslau 원리에 의한 단순보와 연속보의 영향선은 잘 알려져 있고 또 교량공학에서 널리 사용되고 있다. 그러나 변위를 허용하는 특별한 구조물의 영향선을 계산할 경우에는 약간의 어려움이 있다. 이 연구에서는 절점변위를 허용하는 문형라멘의 영향선을 전달행렬법에 의하여 구하고 유한요소법에 의하여 얻은 영향선과 비교하였고 그 결과는 좋은 일치를 보이고 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.24-26
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• 2022

시스톨릭 어레이는 DNN training 등 인공지능 연산의 대부분을 차지하는 행렬 곱셈을 수행하기 위한 하드웨어 구조로 많이 사용되지만, sparsity 가 높은 행렬을 연산할 때 불필요한 동작으로 인해 효율성이 크게 떨어진다. 본 논문에서 제안된 유동적 시스톨릭 어레이는 matrix condensing, weight switching, 그리고 direct output path 의 방법과 구조를 통해 sparsity 가 높은 행렬 곱셈의 수행 사이클을 줄일 수 있다. 시뮬레이션을 통해 기존 시스톨릭 어레이와 유동적 시스톨릭 어레이의 성능을 비교하였으며 8×8, 16×16, 32×32 의 크기를 가진 행렬을 동일 크기의 시스톨릭 어레이로 연산하였을 때 필요 사이클 수를 최대 12 사이클 절감할 수 있는 것을 확인하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.5
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• pp.77-83
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• 1993

A modified Lanczos method combined with a substructure analysis technique was used for calculating natural frequencies and mode shapes of large structural systems. The method does not require generation and storage of stiffness and mass matrices of the entire structure. It only uses the stiffness and mass matrices of each substucture. No approximating assumptions are required other than the usual assumption of linear elastic system modelled by finite elements. Thus, natural frequencies and mode shapes for the finite element model employed are the same as those with or without the suhstructuring algorithm. To check the efficiency of the proposed method, first ten natural frequencies and the corresponding mode shapes of an open truss helicopter tail-boom structure are calculated by using it.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.8
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• pp.1212-1219
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• 2009

In this paper, a state feedback gain controller using linear matrix inequality(LMI) for the multi-objective synthesis is designed, in the multi-layer structure with integral type servo system. The design objectives include $H_{\infty}$ performance, asymptotic disturbance rejection, time-domain constraints, on the closed-loop pole location. The results of computer simulation show the validity of the designed controller.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.8 s.338
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• pp.1-10
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• 2005

In this paper, the explicit low density codes construction from the generalized permutation matrices related to algebra theory is investigated, and we design several Jacket inverse block matrices on the recursive formula and permutation matrices. The results show that the proposed scheme is a simple and fast way to obtain the low density codes, and we also Proved that the structured low density parity check (LDPC) codes, such as the $\pi-rotation$ LDPC codes are the low density Jacket inverse block matrices too.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2B
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• pp.325-333
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• 2010

Most communication systems including Wibro use quasi-cyclic LDPC codes composed of circulants. However, it is very difficult to design quasi-cyclic(QC) LDPC codes with optimal degree distribution satisfying conditions on layered decoding and girth due to the restriction of the size of its base matrix. In this paper, we propose a good solution by introducing superposition matrices to QC LDPC codes. We derive the conditions on checking girth of QC LDPC codes with superposition matrices, and propose new decoder to support layered decoding both for original QC LDPC codes and their modifications with superposition matrices. Simulation results show considerable improvements to convergence speed and error-correcting performance of proposed scheme which adopts QC LDPC codes with superposition matrices.

• Computational Structural Engineering
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• v.2 no.4
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• pp.111-116
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• 1989

Methods for the estimation of the coefficient matrices in the equation of motion for a linear multi-degree-of-freedom structure are studied. For this purpose, the equation of motion is transformed into an auto-regressive and moving average with auxiliary input(ARMAX) model. The ARMAX parameters are evaluated using several methods of parameter estimation : such as the least squares, the instrumental variable, the maximum likelihood and the limited information maximum likelihood methods. Then the parameters of the equation of motion are recovered therefrom. Numerical example is given for a 3-story building model subjected to an earthquake exitation.

• Journal of the Korean Institute of Intelligent Systems
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• v.8 no.5
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• pp.51-60
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• 1998

There have been several recent studies concerning the stability of fuzzy control system and the synthesis of stabilizing fuzzy controllers. This paper reports on a related study nf the TS (Takagi-Sugeno) fuzzy systems, and it is shown that the controller synthesis problems for the nonlinear systems described by the TS fuzzy model can be reduced to convex problems involving LMIs (linear matrix ineclualities). After classifying the TS fuzzy systems into three families based on how diverse their input matrices are, different controller synthesis procedure is given for each of these families. A numerical example is presented to illustrate the synthesis procedures developed in this paper.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.1
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• pp.67-70
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• 2022

In the present work, we have designed to optimize the optical filter structures of the 1-dimensional photonic quasicrystals (1D PQCs) characteristic for the COVID-19 UV sterilization. The simulator using MATLAB program and ourselves manufacturing calculation codes. After making the aperiodic (and complexed) multi-layer structure model, we establish the transfer matrix method (TMM) for model by the operator conversion. By the using the MATLAB, we derive a matrix for the designed complexed multi-layer structure by applying the equations to the model by obtaining the reflectance and transmittance from the matrix. We also prove the possibility of application in optical filter for UV sterilization.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.2
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• pp.271-279
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• 2002

This study develops the module to find the lateral stiffness influence matrix of each story and performs the displacement sensitivity analysis by virtual load method for the efficiency of optimal design using lateral stiffness influence matrix. Also, resizing technique based on the estimated lateral stiffness increment factors is developed to apply directly the results of optimal design. To this end, resizing technique is divided into the continuous and discrete section design methods. And then the relationships between section properties and section size are established. Specifically, an initial design under strength constraints is first performed, and then the lateral load resistant system is designed to control lateral displacements yet exceeding the drift criteria. Two types of 45-story three dimensional structures we presented to illustrate the features of the lateral drift control and resizing technique for tall buildings proposed in this study.