• Journal of applied mathematics & informatics
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• 제9권2호
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• pp.891-897
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• 2002

A symmetric minimal complement at infinity for a given symmetric Silvester data set in the complex plane is contructed.

• 대한수학회보
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• 제48권5호
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• pp.1105-1109
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• 2011

We establish a result concerning simultaneous approximation and interpolation from certain uniformly dense subsets of the space of vector-valued continuous functions vanishing at infinity on locally compact Hausdorff spaces.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.54.6-54
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• 2002

1. Introduction 2. The Netwoked Control System Description 2.1 A close-loop system with the network induced delay 2.2 Discretization and State Augmentation of NCS 3. Delay-dependent H_infinity Controller Design for NCS 4. Numerical Example 5. Conclusion

• 한국수학사학회지
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• 제15권2호
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• pp.77-82
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• 2002

This paper is concerned with the mathematical concept displayed in Buddhism, which is reasonable enough to consider as a philosophy and encompasses the concept of infinity as scientific as that of mathematics. The purpose of this paper is to examine the changing process of the Buddhism concept of infinity on the basis of time sequence and to combine this with that of mathematics.

• 대한수학교육학회지:학교수학
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• 제12권1호
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• pp.1-15
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• 2010

포괄적인 연구를 위한 예비 조사로서 본 연구는 학생들이 무한 개념과 극한 개념을 어떻게 다루는지를 조사하였다. 수학은 담화의 하나라는 인식에 관한 상호 의사소통의 접근방식을 바탕으로 이 개념들에 관한 학생들의 담화의 특성들을 확인하려고 하였다. 4명의 미국학생과 4명의 한국학생을 무한과 극한에 대해서 영어로 면담하였고 학생들의 담화를 공통적인 특성들과 문화, 나이, 그리고 교육에 관련된 차이점들에 초점을 맞추어 자세히 조사하였다.

• 전력전자학회논문지
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• 제24권1호
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• pp.49-55
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• 2019

This study proposes a robust control of a fin position servo system using the H-infinity loop-shaping method. The fin position control system has a proportional (P) position controller and a proportional-integral (PI) controller. In this work, the position control loop requires a wide bandwidth. No current control loop exists due to the compact design of the system. Hence, the controller parameters are difficult to determine using the traditional cascade design method. The $H_{\infty}$ controller design method is used to design the controller's gain to achieve good performance and robustness. First, the transfer function of the system, which can be divided into tunable and fixed parts, is derived. The tunable part includes the position P controller and speed PI controller. The fixed part includes the rest of the system. Second, the optimized controller parameters are calculated using Matlab $H_{\infty}$ controller design program. Finally, the system with optimized controller is tested by simulation and experiment. The control performance is satisfactory, and the $H_{\infty}$ controller design method is proven to be valid.

• 한국지반환경공학회 논문집
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• 제20권2호
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• pp.5-18
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• 2019

본 연구에서는 경상북도 전체를 대상으로 공간분포형 습윤지수와 뿌리보강무한사면안정해석 이론을 활용한 광역적인 산사태 분석을 실시하였다. 해석을 수행하기 위해 수치지도와 정밀토양도, 임상도 등을 이용하여 지형 지질학적 매개변수를 추출하고 $10m{\times}10m$ 해상도의 공간분포형 데이터베이스를 구축하였으며, 공간분포형 습윤지수를 생성하기 위한 비 집수면적은 무한방향흐름기법을 적용하였다. 광역적인 산사태 위험도 평가를 위한 안전율은 4개 등급으로 구분하여 도시하였다. 위험도 평가결과, 산사태 위험지역은 봉화와 김천 등 실제 최근의 산사태 발생지역과 유사성을 갖는 것으로 나타났으며 특히 산지와 인접한 지역에 unstable 지역이 집중적으로 분포되어 있는 것으로 분석되었다. 또한 산사태 기록과 비교해본 결과, 본 해석모형이 합리적인 매개변수의 축적을 통해 광역적인 산사태 위험성을 평가하는 유효한 방법임을 확인할 수 있다.

• 대한건축학회논문집:계획계
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• 제34권6호
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• pp.23-30
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• 2018

Gordon Cullen, who tried to understand urban landscapes in terms of visual attention, introduced a concept called 'Space and Infinity' in his book 'Townscape'. According to him, urban images like infinity spreading across the sky are more effectively created when we happen to see an open space while walking along a ground-level street than when we look at the sky. This study aims to quantitatively examine if urban observers pay more attention to spaces like pilotis on the bottom of a building. Thus, this study collected observers on actual urban landscape images and partially-edited images and conducted an experiment by adopting Eye-movement Tracking to find out if they actually pay more visual attention to a space like pilotis. This study selected a total of 50 people as research subjects and divided them into two groups. Image 1 was shown to one group, and Image 2 with the pilotis space edited was shown to the other group. As an experiment to find objective evidences on Gordon Cullen's 'Space and Infinity', this study analyzed difference between Image 1 and Image 2, and it was found that the domain of pilotis showed a value five times higher than the average visual attention since it attracted much visual attention although it was very small in area. That is, it has objectively clarified that people get most fascinated with a place with infinite images in the background like a pilotis space out of all the urban landscapes as Gordon Cullen's theory. In addition, the differences in visual concentration of pilotis space by sex, by subject was examined, and there was no significant difference in visual concentration of pilotis space by gender. As a result of examining the difference of visual concentration by classifying the subjects into architectural related major, the major group showed higher frequency of viewing than the non - major group.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.303-306
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• 1997

Magnetic bearings have been adopted to support the rotor by electromagnetic force without mechanical contact and have many advantages. The application of the magnetic bearings have become more and more widespread in recent years. But magnetic bearings require feedback control for stable operation because they are inherently open loop unstable systems. In this study, H infinity controller has been applied for rotor-magnetic bearing system for vibration control. The result showed that H infinity controller has better performance than PID controller through simulations.

• 한국수학사학회지
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• 제25권2호
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• pp.57-70
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• 2012

데자르그 정리와 무한원점이라는 사영기하학의 내용에 대하여, 반례의 수학사적 역할에 대한 Lakatos의 관점을 반영한 중등 영재학생용 교수단원을 개발하였다. 본 교수단원에서는 먼저 데자르그 정리의 반례를 인식하고, 이러한 반례를 제거하기 위해 무한원점을 도입하여 정리를 일반화한다. 그리고 다시 변환을 도입하여 반례가 사실 일반적인 경우와 대등한 것임을 재인식하도록 전개하였다. 이 교수단원에서 영재학생들은, 반례로 인하여 데자르그 정리라는 수학적 지식이 어떻게 변화하고 성장할 수 있는가를 경험할 수 있었다.