• 한국컴퓨터정보학회논문지
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• 제10권3호
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• pp.183-188
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• 2005

블록암호알고리즘의 기본 구조인 Feistel 구조는 순차처리 구조이므로 병렬처리가 곤란하다. 그러므로 본 논문은 이러한 순차처리 구조를 변형하여 Feistel 구조가 병렬처리가 가능하도록 하였다. 이를 이용하여 본 논문은 병렬 Feistel 구조를 가지는 DES를 설계하였다. 제안된 병렬 Feistel 구조는 자체의 구조적 문제 때문에 pipeline 방식을 사용할 수 없어 데이터 처리속도와 데이터 보안사이에서 trade-off관계를 가질 수밖에 없었던 DES등과 같은 블록암호알고리즘의 성능을 크게 향상 시킬 수 있었다. 그러므로 Feistel 구조를 적용한 SEED, AES의 Rijndael, Twofish 등에 제안된 방식을 적용할 경우 지금보다 더욱 우월한 보안 기능 및 고속의 처리능력을 발휘하게 될 것이다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.293-296
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• 1997

Robust stability conditions for discrete-time variable structure control is proposed. Conventionally the discrete-time variable structure control method with a variable structure uncertainty compensator approach requires a bounded changing rate of the uncertainties to ensure robust stability. However, when uncertainties vary as a function of state variables, which occur with parametric uncertainties, it is not reasonable to assume a bounded variation on the uncertainties. In this paper, uncertainties are assumed to consist of exogenous disturbances and parametric uncertainties. An uncertainty compensator is used to deal with the former, and a robust stability condition is derived using Small Gain Theorem for the latter.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.317-322
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• 2002

There are many researches to identify the rigid body properties from the mass-line obtained by impact hammer testing. The correct rigid body properties of the structure may be estimated if the mass-line of the structure could be obtained exactly. When the structure is mounted by elastic materials, the mass-line cannot be read correctly from the impulse response spectrum. The reason is due to the effects of rigid body modes of mounted structure. In this paper, the effects of rigid body modes of mounted structure to the mass-line are discussed and the method to remove these effects is also presented.

• 한국철도학회논문집
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• 제11권1호
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• pp.26-32
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• 2008

이 논문은 프로젝트 관리 기법으로 널리 알려진 업무분담구조(WBS)에 관해 다루고 있다. 그러나 현재 국내산업에서 사용되고 있는 WBS는 잘못된 형식을 취하고 있다. 이러한 문제점은 WBS의 핵심요소인 물리적 계층 구조(PBS)가 공간 중심적으로 잘못 구축됨으로써 발생한다. 이 논문은 국내 철도 산업에서 작성된 PBS를 예제로 하용하여, 설계 구조 매트릭스(DSM)를 이용하여 기능 중심적 PBS로 새로이 구축하는 방법을 제시한다. 제안된 방법론과 프로세스는 빠른 시간 내에 올바른 PBS를 구축하는데 유용할 것이다.

• Structural Monitoring and Maintenance
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• 제4권4호
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• pp.351-364
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• 2017

In this study effects of various parameters like a number of bays, the stiffness of the structure along with the height of the structure was examined. The fundamental period of vibration T of the building is an important parameter for evaluation of seismic base shear. Empirical equations which are given in the Indian seismic code for the calculation of the fundamental period of a framed structure, primarily as a function of height, and do not consider the effect of number of bays and stiffness of the structure. Building periods predicted by these expressions are widely used in practice, although it has been observed that there is scope for further improvement in these equations since the height alone is inadequate to explain the period variability. The aim of this study is to find the effects of a number of bays in both the directions, the stiffness of the structure and propose a new period equation which incorporates a number of bays, plan area, stiffness along with the height of the structure.

• 한국소음진동공학회논문집
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• 제21권2호
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• pp.120-128
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• 2011

This paper presents an efficient method to analyze noise and vibration of marine diesel engines mounted on flexible hull structure. The analysis model should in general include the hull structure, leading to lots of computational efforts. To minimize the computational efforts, in this paper, the transfer synthesis utilizing the receptance at the mounting points is proposed. The procedure is then verified by comparing the results with those from the full model calculation. The effects of flexible hull structure on the acoustic power from engine block are finally investigated. It is found that the effect of the hull is significant when the receptance of hull structure is similar to or greater than that of mount or engine block.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.59-64
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• 2003

This paper describes the result of structure analysis and load test of body structure. The purpose of the analysis and test is to evaluate an safety which body structure shall be considered fully sufficient rigidity so as to satisfy proper system function under maximum load and operating condition. Material of body structure applied an aluminum alloy. This strength test is based on 'Performance Test Standard for Electrical Multiple Unit, noticed by Ministry of Construction & Transportation, in 2000' and reference code is JIS E 7105

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.49-54
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• 2005

This paper describes the result of structure analysis and load test of body structure. The purpose of the analysis and test is to evaluate an safety which body structure shall be considered fully sufficient rigidity so as to satisfy proper system function under maximum load and operating condition. Material of body structure applied an aluminum alloy. Body structure consist of side frame, under frame, roof frame, end frame. Both FEM analysis and load test are based on 'Performance Test Standard for Electrical Multiple Unit, noticed by Ministry of Construction & Transportation, in 2000' and reference code is JIS E 7105. The test results have been very safety and stable fer design load conditions.

• Steel and Composite Structures
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• 제26권2호
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• pp.163-170
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• 2018

The purpose of this paper is to present a new and efficient optimization algorithm called Jaya for optimum design of steel grillage structure. Constrained size optimization of this type of structure based on the LRFD-AISC is carried out with integer design variables by using cross-sectional area of W-shapes. The objective function of the problem is to find minimum weight of the grillage structure. The maximum stress ratio and the maximum displacement in the inner point of steel grillage structure are taken as the constraint for this optimization problem. To calculate the moment and shear force of the each member and calculate the joint displacement, the finite elements analysis is used. The developed computer program for the analysis and design of grillage structure and the optimization algorithm for Jaya are coded in MATLAB. The results obtained from this study are compared with the previous works for grillage structure. The results show that the Jaya algorithm presented in this study can be effectively used in the optimal design of grillage structures.

• 대한전자공학회논문지
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• 제19권6호
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• pp.1-8
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• 1982

이 논문은 하중나무에 의한 래더형 회로의 새로운 해석 방법을 제안한다. 종래의 정보 구조를 나타내는 나무와는 달리 가지의 하중를 임피이던스 Z와 어드미턴스 Y로 하고, 그의 양단의 마디를 전압과 전류의 짝으로 표시하여 Z와 Y집합의 계층 구조의 나무를 구성한다. 다음에 나무에서 생성 레벨을 정의하고 기준 레벨과 임의의 레벨간을 path함으로써, 구동점 임피이던스, 전달함수, 전달 임피이던스를 계산에 의하지 않고 시각적으로 동시에 구한다. 본 방법에 의하여 가역정리를 유도함으로써 타당성을 입증하고 4단자 정수 및 피이드백, Tr결합 텐덤 회로에도 적용된다. In this paper a new analytic method for Ladder networks by weighted tree is proposed. In contrast to conventional tree concept that represents only information structure, in this paper, a tree with hierarchical structure is established by giving wei체t of impedance Z and admittance Y to branch and representing each node of its branch as a pair of voltage and current. Then, by defining generation level from tree structure and by parsing between standand level and arbitrary level, driving point impedance, transfer function and transfer impedance are simultaneously obtained instead of complex calculation method by inspection. The validity of this method is proved by the reciprocal theorem and this method is applied to four-terminal constants and the feedback network.