• Structural Monitoring and Maintenance
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• 제4권4호
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• pp.365-379
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• 2017

This paper presents a comparison of the black-box and the physics based derived gray-box models for subspace identification for structures subjected to support-excitation. The study compares the damage detection capabilities of both these methods for linear time invariant (LTI) systems as well as linear time-varying (LTV) systems by extending the gray-box model for time-varying systems using short-time windows. The numerically simulated IASC-ASCE Phase-I benchmark building has been used to compare the two methods for different damage scenarios. The efficacy of the two methods for the identification of stiffness parameters has been studied in the presence of different levels of sensor noise to simulate on-field conditions. The proposed extension of the gray-box model for LTV systems has been shown to outperform the black-box model in capturing the variation in stiffness parameters for the benchmark building.

• 방재기술
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• 통권30호
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• pp.46-54
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• 2001

According to the use of electric power increases, the fire which ignited by electrical causes increases too. In this thesis electrical fires which occurs in the country for the past ten years are analyzed and developed the technology to identify the electrical fire. The focus of study is method to identify the electrical fires. The causes of electrical fire, it is analyzed a short-circuit and a over current, which take the highest ratio compare with other causes. The rationalization of identification, an electrical operating status is continuous monitored and the status can be accessed, black-box for identification electrical fires. The results of the study are the causes of electrical fire are found out logically, and the developed black-box for identification fires.

• Geomechanics and Engineering
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• 제13권6호
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• pp.997-1010
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• 2017

The black box model is a relatively new option for nonlinear dynamic system identification. It can be used for prediction problems just based on analyzing the input and output data without considering the changes of the internal structure. In this paper, a black box model was presented to solve unconstrained overlying strata movement problems in coal mine production. Based on the black box theory, the overlying strata regional system was viewed as a "black box", and the black box model on overburden strata movement was established. Then, the rock mechanical properties and the mining thickness and mined-out section area were selected as the subject and object respectively, and the influences of coal mining on the overburden regional system were discussed. Finally, a corrected method for height prediction of the fractured zone was obtained. According to actual mine geological conditions, the measured geological data were introduced into the black box model of overlying strata movement for height calculation, and the fractured zone height was determined as 40.36 m, which was comparable to the actual height value (43.91 m) of the fractured zone detected by Double-block Leak Hunting in Drill. By comparing the calculation result and actual surface subsidence value, it can be concluded that the proposed model is adaptable for height prediction of the fractured zone.

• 제어로봇시스템학회논문지
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• 제4권2호
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• pp.209-214
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• 1998

In this paper, we are dealing with the problem of controlling unknown nonlinear dynamical system by using neural networks. A novel error self-recurrent(ESR) neural model is presented to perform black-box identification. Through the various outcome of the experiment, a new neural network is seen to be considerably faster than the BP algorithm and has advantages of being less affected by poor initial weights and learning rate. These characteristics make it flexible to design the controller in real-time based on neural networks model. In addition, we design an adaptive PID controller that Keyser suggested by using ESR neural networks, and present a method on the implementation of adaptive controller based on neural network for practical applications. We obtained good results in the case of robot manipulator experiment.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.1334-1337
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• 2006

System identification is the field of modeling dynamic systems from experimental data. As a modeling technique, we can mention finite element method (FEM). In addition, we are able to measure modal data as the experimental data. The system can be generally categorized into a gray box and black box. In the gray box, we know mathematical model of a system, but we don't know structural parameters exactly, so we need to estimate structural parameters. In the black box, we don't know a system completely, so we need to identify system from nothing. To date, various system identification methods have been developed. Among them, we introduce system realization theory which uses Hankel matrix and Eigensystem Realization Algorithm (ERA) that enable us to identify modal parameters from noisy measurement data. Although we obtain noise-free data, however, we are likely to face difficulties in identifying a structure with hidden modes. Hidden modes can be occurred when the input or output position comes to a nodal point. If we change a system using a mode decoupling controller, the hidden modes can be revealed. Because we know the perturbation quantities in a closed loop system with the controller, we can realize an original system by subtracting perturbation quantities from the closed loop system. In this paper, we propose a novel method to identify a structure with hidden modes using the mode decoupling controller and the associated example is given for illustration.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 B
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• pp.561-563
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• 1997

In this paper, we identified the Black-box system with serious nonlinerity and fast dynamics using Neural Network. This NN have new structure and learned by RLS. It identify system in real-time without priori data. We use this NN to 7-DOF vehicle identification.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1449-1454
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• 2003

For many industrial processes there are good static models used for process design and steady state operation. By using system identification techniques, it is possible to obtain black-box models with reasonable complexity that describe the system well in specific operating conditions [1]. But black-box models using inductive modeling(IM) is not suitable for model based control because they are only valid for specific operating conditions. Thus we need to use deductive modeling(DM) for a wide operating range. Furthermore, deductive modeling is several merits: First, the model is possible to be modularized. Second, we can increase and decrease the model complexity. Finally, we are able to use model for plant design. Power plant must be able to operate well at dramatic load change and consider safety and efficiency. This paper proposes a simplified nonlinear model of an industrial boiler, one of component parts of a power plant, by DM method and applies optimal control to the model.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2020년도 추계학술발표대회
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• pp.593-596
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• 2020

많은 차량에 부착되어 있는 블랙박스를 활용하여 수집된 이미지 데이터들을 분석, 도로의 파손 상태를 체크하고 웹 서버에 표시하고 관련 기관에 신고합니다. 따라서 해당 도로를 이용하는 운전자들에게 도로의 상황을 알려주고 보수 조치가 빠르게 이루어 질 수 있도록 도와주는 서비스입니다.

• 보존과학회지
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• 제33권1호
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• pp.17-24
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• 2017

국립중앙박물관 소장품인 조선왕조실록상자(고적 25247)에 사용된 목재의 수종식별과 칠층의 특징을 관찰하고, 보존처리 과정 및 결과를 소개 위하여 본 연구를 실시하였다. 조사결과 실록상자의 제작에는 피나무과의 피나무속(Tilia spp.)의 목재가 사용되었다. 표면의 칠기법은 목재 위에 골회를 칠하고 닥나무속(Broussonetia spp.) 인피섬유로 제작한 한지를 덧바른 뒤 다시 토회칠, 흑칠, 정제옻칠, 흑칠 순서로 제작하였다. 보존처리 전 실록상자의 상태는 짜임이 벌어지고, 칠이 벗겨져 있었으며 장석이나 족대 등 일부 부재가 사라진 상태이었다. 이러한 손상부위는 아교 및 토회로 강화처리하여 안정적인 상태가 되도록 수리하였고, 결실부는 수종분석 결과와 남아있는 부재의 형태를 바탕으로 최대한 원형에 가깝게 복원하였다. 이를 통해 실록상자의 기초적인 제작방법을 파악할 수 있었다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제34회 춘계학술대회논문집
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• pp.279-287
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• 2010

본 논문에서는 가스터빈 엔진, 로켓 등과 같은 연소시스템에서 발생하는 고진폭-고주파 열음향학적 불안정을 능동적으로 제어하는데 필수적인 동역학적 모델링에 대한 연구 동향을 소개한다. 이를 위하여 1990년대 이후에 진행되었던 연구를 저차의 시스템 모델링 기법을 중심으로 조사하였으며, 특히 물리적 원리로부터 모델의 구조를 결정하고 시스템의 입출력 데이터를 기반으로 모델 파라미터를 추정하는 그레이박스 접근방법과 물리적 원리의 적용 없이 시스템 특성을 추정하는 블랙박스 기법을 소개한다. 또한 동 분야에 대한 향후 가능성에 대하여 간략히 기술한다.