• 한국정밀공학회지
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• 제15권12호
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• pp.202-211
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• 1998

The present paper proposes a modal analysis procedure to obtain exact modal parameters (natural frequencies, damping ratios, eigenvectors) for general, non-uniform beam-like structures. The proposed method includes a derivation of the system dynamic matrix for a Timoshenko beam element. The proposed method provides not only exact modal parameters but also exact frequency response functions (FRFs) for general beam structures. A time domain analysis method is also proposed. Two examples are provided for validating and illustrating the proposed method. The first numerical example compares the proposed method with FEM. The second example deals with a non-uniform beam structure supported in joints with damping property. The numerical study proves that the proposed method is useful for the dynamic analysis of continuous systems consisting of beam-like structures.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.579-582
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• 1999

This paper presents a design method of deadbeat controller for DC motor driving a rotational system with gear. The results of sampling a continuous-data process does not guarantee that no ripples occur between the sampling instants in the continuous-data output, but the proposed deadbeat control system that consists of the integral controller and the full state observer, and zero order hold using in continuous systems, has many advantages of such as an output response without the ripple and reaching the steady state without error after a given sampling period and faster settling time than the optimal control system in the short sampling period. The results of case study through matlab simulation shown that the efficiency of the proposed controller for DC motor driving a rotational system with gear, is verified by comparing with optimal controller etc.

• 센서학회지
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• 제28권2호
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• pp.88-93
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• 2019

This paper is concerned with distributed fusion moving average prediction for continuous-time linear stochastic systems with multiple sensors. A distributed fusion with the weighted sum structure is applied to the optimal local moving average predictors. The distributed fusion prediction algorithm represents the optimal linear fusion by weighting matrices under the minimum mean square criterion. The derivation of equations for error cross-covariances between the local predictors is the key of this paper. Example demonstrates effectiveness of the distributed fusion moving average predictor.

• 대한기계학회논문집
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• 제16권1호
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• pp.41-52
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• 1992

본 연구에서는 쌍선형 함수를 이용하여 연속시스템의 상태공간에서 설계된 폐 루우프계로 부터 이산시스템의 피이드백 게인행렬을 얻을 수 있는 디지탈재설계법이 제안 되었고, 크레인의 실시간 제어를 통해 본 연구에서 제안된 디지탈 재설계법의 유 효성을 확인했다.

• 산업경영시스템학회지
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• 제37권4호
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• pp.12-23
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• 2014

The O&M (Operation and Maintenance) phase of offshore plants with a long life cycle requires heavy charges and more efforts than the construction phase, and the occurrence of an accident of an offshore plant causes catastrophic damage. So previous studies have focused on the development of advanced maintenance system to avoid unexpected failures. Nowadays due to the emerging ICTs (Information Communication Technologies) and sensor technologies, it is possible to gather the status data of equipment and send health monitoring data to administrator of an offshore plant in a real time way, which leads to having much concern on the condition based maintenance policy. In this study, we have reviewed previous studies associated with CBM (Condition-Based Maintenance) of offshore plants, and introduced an algorithm predicting the next failure time of the compressor which is one of essential mechanical devices in LNG FPSO (Liquefied Natural Gas Floating Production Storage and Offloading vessel). To develop the algorithm, continuous time Markov model is applied based on gathered vibration data.

• 한국컴퓨터정보학회논문지
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• 제11권6호
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• pp.289-298
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• 2006

무선 네트워크(Wireless Network)의 약한 연결성 및 접속단절, 모바일 클라이언트의 이동성. 모바일 클라이언트의 휴대성으로 인해 발생하는 모바일 데이터베이스 시스템(Mobile Database System) 관련 이슈들과 이 문제들을 해결하기 위한 연구들이 한창이다. 이동 컴퓨팅은 언제 어디서나 원하는 모든 정보를 이용할 수 있는 사용자의 편의성이나 성능 면에서의 요구를 만족시키고 있지만, 데이터 관리 측면에서는 해결되어야만 하는 많은 문제점들을 안고 있다. 본 논문은 모바일 클라이언트-서버(Mobile Client-Server) 환경에서 모바일 데이터베이스 시스템 특성상 가질 수 있는 무선 네트워크의 약한 연결성 및 접속성 단절로 인한 데이터베이스 비축(Database Hoarding)과 관련된 문제 공유 데이터(Shared Data)의 일관성(Consistency)유지 문제, 그리고 로그 최적화 문제를 해결하기 위한 모바일 연속 질의 처리 시스템(MCQPS : Mobile Continuous Query Processing System)을 포함하는 새로운 모바일 클라이언트-서버 시스템을 설계하는데 목적이 있다. 또한. MCQPS의 효율성 증명을 위해 C-I-S(Client-Intercept -Server) 모델과의 성능비교를 통해 제안한 시스템이 우수하다는 것을 입증한다. 그리고 실시간 연속 질의를 위해 제안한 색인 구조와 기법의 효율성을 입증하기 위해 다양한 실험을 수행한다.

• 제어로봇시스템학회논문지
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• 제14권10호
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• pp.977-982
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• 2008

In this paper Haar functions are developed to approximate the solutions of continuous time linear system. Properties of Haar functions are first presented, and an explicit expression for the inverse of the Haar operational matrix is presented. Using the inverse of the Haar operational matrix the full order Stein equation should be solved in terms of the solutions of pure algebraic matrix equations, which reduces the computation time remarkably. Finally a numerical example is illustrated to demonstrate the validity of the proposed algorithm.

• Transactions on Control, Automation and Systems Engineering
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• 제1권1호
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• pp.44-49
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• 1999

This paper presents a new T-S(Tae-Sugeno) fuzzy controller design method satisfying the output energy bound. Maximum output energy via a quadratic Lyapunov function to obtain the bound on output energy is derived. LMI(Linear Matrix Inequality) problems which satisfy an output energy bound for both of the continuous-time and discrete-time T-S fuzzy control system are also derived. Solving these LMIs simultaneously, we find a common symmetric positive definite matrix P which guarantees the global asymptotic stability of the system and stable feedback gains K's satisfying the output energy bound. A simple example demonstrates validity of the proposed design method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.534-537
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• 1995

In this paper, we propose a control strategy for a class of nonholonomic systems. A system with nonholonomic constraint is called a nonholonomic system, and as Brockett showed, the equilibrium of such systems can not be stabilized with any continuous static state feedbacks even though the system is controllable in the sense of nonlinear. A control strategy we propose is transforming this system into time-state control form by coordinate transformation and input transformation. We will apply this control strategy to the motion control of a rigid ball that is held between two parallel plates.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1783-1784
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• 2008

This paper presents a novel control technique to deal with networked control systems with neutral timedelay, which is known to highly degrade the control performance of the controlled system. The stability analysis and design method for a sampled-data fuzzy controller for discrete networked control systems (NCS). The neutral time-delay and sampling activity will complicate the NCS. And it make the stability analysis much more difficult than that for a continuous-time NCS. Based on the fuzzy control approach, linear matrix inequality (LMI)-based stability conditions are derived to guarantee the neutral T-S fuzzy system stability. The simulation results and practical experiments illustrate that the proposed controller design is realistic.