• 정보처리학회논문지C
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• 제15C권6호
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• pp.493-506
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• 2008

본 논문은 역할 기반 접근 제어 모델 연구를 통해 u-헬스케어 환경의 요구사항을 충족하는 상황 기반의 동적 접근제어 모델을 제안한다. 동적 보안 도메인 관리를 위해 분산객체그룹 프레임워크를 사용하였고, 동적 접근제어를 위한 상황 정보는 기 구축된 데이터베이스를 사용하였다. 본 논문에서는 러프집합 이론을 근거로 의사결정 테이블에서 지식감축을 통해 의사결정 규칙을 정의하고, 생성된 규칙을 동적 접근제어 모델에 적용하였다. 그리고 분산객체그룹 프레임워크를 기반으로 u-헬스케어 응용을 통해 상황기반 동적 보안 서비스의 수행 결과를 보였다. 이 결과, 동적 접근 제어 모델은 u-헬스케어 환경에서 보안 도메인에 따라 적합한 보안 서비스와 보다 유연한 접근제어를 제공한다.

• International Journal of Control, Automation, and Systems
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• 제3권4호
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• pp.533-541
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• 2005

In this paper, a wind turbine with power splitting transmission, which is realized through a novel three-shaft planetary, is presented. The input shaft of the transmission is driven by the rotor of the wind turbine, the output shaft is connected to the grid via the main generator (asynchronous generator), and the third shaft is driven by a control motor with variable speed. The dynamic models of the sub systems of this wind turbine, e.g. the rotor aerodynamics, the drive train dynamics and the power generation unit dynamics, were given and linearized at an operating point. These sub models were integrated in a multidisciplinary dynamic model, which is suitable for control syntheses to optimize the utilization of wind energy and to reduce the excessive dynamic loads. The important dynamic behaviours were investigated and a wind turbine with a soft main shaft was recommend.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1721-1726
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• 2004

The studies of the half active suspension have been performed using various suspension models. In the early days, the modeling considered the inputs to the active suspension as the linear forces. Recently, due to the development of new control theory, the forces input to the half car active suspension system has been replaced by an actual input to the hydraulic actuators. Therefore, the dynamic of the active suspension system now consists of the dynamic of half car suspension system plus the dynamic of the hydraulic actuators. This paper proposed a new modeling technique in integrating both dynamic models. The proportional integral sliding mode control technique is utilized to control the hydraulically actuated of the half car active suspension system. The performance of the half car hydraulically actuated active suspension system is simulated with a bump input. The results show that the proposed modeling technique and the proportional integral sliding mode controller are improved the ride comfort and ride handling of the half car active suspension system.

• 대한전기학회논문지
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• 제40권8호
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• pp.816-824
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• 1991

It is well known that dynamic control is needed for fast and accurate control. Neural networks are ideal for representing the strongly nonlinear relationship in the dynamic equations including complex unmodeled effects. It thus creates many advantages over conventional methods such as simple, fast and accurate control through neural network's inherent learning and massive parallelism. In this paper, dynamic control of the full six degrees of freedom of an industrial robot arm will be presented using neural networks. Moreover, through application to a real robot the usefulness of neurocontrol is demonstrated. The back propagation and feedback-error learning is used to train the neurocontroller. Simulated control of a PUMA 560 arm demonstrates that it moves at high speed with good accuracy and generalizes over untrained trajectories as well as adapt to unforseen load changes and sensor noise.

• 펄프종이기술
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• 제35권3호
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• pp.1-12
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• 2003

The complexity of the papermaking system accelerates interactions between a large number of variables involved. The process operation, therefore, is subject to frequent perturbations by disturbance. Dynamic modelling is a useful tool for characterizing the transient behavior and selecting the best control strategies to reject disturbances. In this study we developed a dynamic simulation model of a fine paper production process, which consists of stock preparation, wire sections, white water circulations, and broke system. It focused on dynamic simulation in its role for developing control strategies and studying control loop dynamics related to filler loading for ash control. The results emphasized the importance of filler-loading position and length of control loop for rapid ash control and process stabilization.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.425-426
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• 2006

This study proposes a new simulation method of high speed rotor system with the dynamic model using multi body dynamic analysis tool and with a new phase modulating technique as a system control algorithm. A dynamic model of high speed rotor system was built by, ADAMS, commercial multi body dynamic program. The phase modulating technique is a new control algorithm for a rotor system. This algorithm can control system using an adaptive proportional gain and an adaptive phase which are obtained from periodical input signal. To make control system, a ADAMS model and component parameters and phase controller was composed by Matlab Simulink And simulate it.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.196-201
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• 2002

This paper deals with the active vibration control of a simply-supported beam under a Moving mass using fuzzy control technique. Governing equation3 for dynamic responses of the beam under a moving mass are derived by Galerkin's mode summation method. Dynamic responses of the beam are obtained by Runge-Kutta integration method, and are compared with experimental results. For the active vibration control of the beam due to moving mass, a controller based on fuzzy logic was designed. The numerical predictions for dynamic deflections of the beam have a good agreement with the experimental results well. As for the fuzzy control of the tested beam, more than 50% reductions of dynamic deflection and residual vibrations under a moving mass are demonstrated.

• International Journal of Control, Automation, and Systems
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• 제6권4호
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• pp.495-505
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• 2008

This paper describes modeling Voltage Sourced Inverter (VSI) type Flexible AC Transmission System (FACTS) controllers and control methods for power system dynamic stability studies. The considered FACTS controllers are the Static Compensator (STATCOM), the Static Synchronous Series Compensator (SSSC), and the Unified Power Flow Controller (UPFC). In this paper, these FACTS controllers are derived in the current injection model, and it is applied to the linear and nonlinear analysis algorithm for power system dynamics studies. The parameters of the FACTS controllers are set to damp the inter-area oscillations, and the supplementary damping controllers and its control schemes are proposed to increase damping abilities of the FACTS controllers. For these works, the linear analysis for each FACTS controller with or without damping controller is executed, and the dynamic characteristics of each FACTS controller are analyzed. The results are verified by the nonlinear analysis using the time-domain simulation.

• 제어로봇시스템학회논문지
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• 제17권4호
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• pp.304-312
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• 2011

In an oligopolistic market, only a few firms account for most or all of total production, e.g., automobile, steel, and computer industries. For a dynamic oligopolistic market with two firms competing in quantities, we show that supervisory control theory of discrete event systems provides a novel approach to solve the dynamic oligopoly problem with the aim of maximizing the profits of both firms. Specifically, we show that the controllability, observability, and nonblocking property (which are the core concepts in supervisory control theory) are the necessary and sufficient conditions for two oligopolistic firms in disequilibrium to eventually reach equilibrium states of maximizing the profits of both firms.

• 대한전기학회논문지
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• 제38권11호
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• pp.877-887
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• 1989

In this paper, we attempt to achieve high dynamic performance by means of decoupled control of rotor speed and flux. Recently developed nonlinear feedback control theories are utilized. The rotor fluxes are estimated based on the rotor circuit equations. When the estimation error of the rotor flux tends to zero, the rotor speed and flux dynamic characteristics of the induction motor with our controller become linear. To minimize the deterioration of control performance, we use an identification algorithm for the rotor resistance. We analyze the dynamic behavior of the closed loop system with our controller. Both simulation and experimental results are included to demonstrate the practical significance of our result. In particular, our experimental results show that recently developed nonlinear feedback control techniques are of practical use in control of induction motors.