• 한국문헌정보학회지
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• 제40권2호
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• pp.415-434
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• 2006

우리 고전 문집에 나타난 용어로 작성된 디스크립터들을 분류하기 위해서 분류 체계를 개발하는 것이 이 연구의 목적이다. 고전 용어 시소러스의 분류 구조는 6개의 패싯으로 범주화를 시작하여 고전 분야의 지식을 근거로 연역적으로 분류 체계를 구조화하였다. 그리고 기존의 인문학 분야의 다른 시소러스들의 분류 체계와 비교하였고, 이러한 비교를 통해서 얻은 것은 고전 용어 분류 체계만이 갖는 여러 장점들 즉 패싯 기법을 적용한 장점 등을 확인할 수 있었다. 이러한 장점들로 인해서 범주 설정의 일관성과 분류 구조의 복잡성을 줄일 수 있었다. 또한 시대나 지역을 구분하기 위한 공통 구분을 독립적으로 설정하여 분류표의 크기를 줄일 수 있었다. 이 분류 체계는 디스크립터들을 배정하는 과정을 통해 보다 나은 분류 체계로 발전해 나갈 것이다.

• 한국항만학회지
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• 제14권1호
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• pp.57-64
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• 2000

For composing the structure model of national maritime power system by system structural modeling, in this study, the 50 basic factors are selected by survey of the extensive and through literatures on maritime, sea, maritime power and sea power. And the basic factors are classified into 36 component factors by cluster method. The 9 attributes are extracted by the application of the principle component analysis method, one of the factor analysis method in system engineering, to component factors. In this study, we define the attributes composing the national maritime power system by integrating the result of this study and existed our studies relating to this topic. Which are showed in Table 2. and we show the structure model of national maritime power system in Fig. 3. In Table 2, the 9 attributes are as follows : the fundamental power of maritime, shipping and port power, naval power, fishing power, shipbuilding power, the power of ocean research and development, dependency on seaborne trade, the protection power of ocean environment and the will and inclination of govemment. Also, in the case of evaluating this system, we conform the importance of considering the interactions among the attributes which have strong interactions in structure model of national maritime power system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1027-1036
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• 2007

Since the opening of the Seoul Metro in 1974, the electric railway passengers have been increased rapidly and as the advanced equipments(OC,PSD) were introduced, additional power facilities were built in a limited area for the comfortable transportation environment. Present grounding system were built according to old Electric equipment standards and all the electric signal, communication and electronic equipments were built only for the purposes of protecting building structure, people and electronic equipments. Grounding system which was additionally built in the limited area caused problems with the building structure and it caused secondary damages when earth fault happens. One of the problems is grounding system of the building structure; grounding system does not work properly since grounding equipments are not separated from each other. So, existing grounding system needs to be improved and unified grounding system in the building should be established. The purposed of this study is to analyze all the grounding systems that had been built in different year and to establish unified grounding system of Seoul Metro.

• 융합신호처리학회논문지
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• 제5권2호
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• pp.138-142
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• 2004

본 논문은 모델추종 제어을 위한 PID제어기법을 제안한다. 이산시간영역에서 제어성능을 개선하기 위해 제안하였고, PID 제어계에 새로운 전치 보상기를 삽입하여 모델추종제어계가 되도록 하였다. 외란이나 부하변동에 의해서 계의 응답이 변할 때 PID 제어기의 이득을 재조정할 필요가 있다. PID 제어계에서 각 PID 이득이 제어계의 성능을 크게 좌우하게 되므로 신경망을 PID제어기에 결합하여 제어계의 성능을 향상시켰고 제안한 제어계에서 PID제어기의 이득은 역전파 알고리즘에 의해 자동적으로 조정되어지도록 하였다. 모델추종 제어계의 제어성능을 확인하기 위하여 제어대상을 직류 서보 전동기의 각 위치로 하였다. 이것을 위치 제어계에 적용하여 실험을 통해 그 성능을 증명하였다.

• Earthquakes and Structures
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• 제16권6호
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• pp.743-755
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• 2019

In this paper, a new system of seismic isolation for buildings - called suspended columns - is introduced. In this method, the building columns are placed on the hinged cradle seats instead of direct connection to the foundation. In this system, each of the columns is put on a seat hung from its surrounding area by a number of cables, for which cavities are created inside the foundation around the columns. Inside these cavities, the tensile cables are hung. Because of the flexibility of the cables, the suspended seats vibrate during an earthquake and as a result, there is less acceleration in the structure than the foundation. A Matlab code was written to analyze and investigate the response of the system against the earthquake excitations. The findings showed that if this system is used in a building, it results in a significant reduction in the acceleration applied to the structure. A shear key system was used to control the structure for service and lateral weak loads. Moreover, the effect of vertical acceleration on the seismic behavior of the system was also investigated. Effect of the earthquake characteristic period on the system performance was studied and the optimum length of the suspension cables for a variety of the period ranges was suggested. In addition, measures have been taken for long-term functioning of the system and some practical feasibility features were also discussed. Finally, the advantages and limitations of the system were discussed and compared with the other common methods of seismic isolation.

• 로봇학회논문지
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• 제17권3호
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• pp.288-295
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• 2022

This study shows a system identification method of a balancing loading device for a stair climbing delivery robot. The balancing loading device is designed as a 2-axes gimbal structure and is interpreted as two independent pendulum structures for simplifying. The loading device's properties such as mass, moment of inertia, and position of the center of gravity are changeable for luggage. The system identification process of the loading device is required, and the controller should be optimized for the system in real-time. In this study, the system identification method is based on least squares method to estimate the unknown parameters of the loading device's dynamic equation. It estimates the unknown parameters by calculating them that minimize the error function between the real system's motion and the estimated system's motion. This study improves the accuracy of parameter estimation using a null space solution. The null space solution can produce the correct parameters by adjusting the parameter's relative sizes. The proposed system identification method is verified by the simulation to determine how close the estimated unknown parameters are to the real parameters.

• 한국터널지하공간학회 논문집
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• 제19권2호
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• pp.161-177
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• 2017

본 연구는 해저터널에서 급격한 홍수 피해를 방지하기 위해 팽창구조체의 설계 및 현장적용을 제시하였다. 팽창구조체는 지중 구조물에 시공 및 운영 시 발생되는 돌발용수 및 이상누수에 의한 사고들에 대비한 많은 가치가 있는 수동적 급속차폐시스템이다. 특히 해저터널에 있어서는 필수적이라고 할 수 있다. 팽창구조체의 설계에서 주요인자는 인플레이터와 터널 벽면사이의 누수 와 마찰 거동이다. 팽창구조체의 설계시 설계 고려사항을 개발하고 매개 변수를 조사하기 위해 이론분석 및 실험적 연구를 수행하였다. 팽창구조체의 주요 설계 요소 및 고려사항들을 제안하기 위하여 박막이론을 적용한 이론적 분석 및 개발하였다. 또한 여러 섬유 재료의 상대 마찰 시험은 인플레이터와 터널 표면 사이의 마찰 조건에 따라 마찰거동을 결정하기 위해 수행하였다. 시험 결과는 침수조건에서의 마찰 계수가 건조조건에서의 값보다 약 20% 낮게 나타났다. 추가로 한국에서 계획중인 2개의 가상해저터널현장에 대한 보호시스템 가상 설계를 본 연구를 바탕으로 수행하였다. 이 연구 결과로부터 향후 터널 보호 구조물인 인플레이터 구조 설계 및 개발 기술을 이해하는데 매우 유용할 것으로 기대된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.458-463
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• 1997

In this paper, we propose a variable structure control approach for the system with matched and unmatched uncertainty. By using time-varying sliding mode, the reaching mode is removed, and the design methodology represents a realistic design approach with quadratic criterion for systems incorporating both matched and unmatched uncertainties. The criterion contains states and linear part of input for all time. The practical application of the control strategy is presented in the design of a stability augmentation system for an aircraft is presented.

• 제어로봇시스템학회논문지
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• 제11권6호
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• pp.492-495
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• 2005

This paper deals with the problem of estimating the asymptotic stability region(ASR) of uncertain variable structure systems with bounded control. Using linear matrix inequalities(LMIs) we estimate the ASR and we show the exponential stability of the closed-loop control system in the estimated ASR. We show that our estimate is always better than the estimate of [3].

• 대한전기학회논문지:시스템및제어부문D
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• 제51권12호
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• pp.556-561
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• 2002

In this paper, a discrete-time variable structure controller for linear time-varying sampled-data systems with disturbances is proposed. The proposed method guarantees that the system state if globally uniformly ultimately bounded (G.U.U.B), and the ultimate bound is shown to be the order of T, O(T), where T is a sampling period.