• 제어로봇시스템학회논문지
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• 제16권7호
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• pp.646-654
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• 2010

This paper describes an integrated chassis control for a maneuverability, a lateral stability and a rollover prevention of a vehicle by the using of the ESC and AFS. The integrated chassis control system consists of a supervisor, control algorithms and a coordinator. From the measured and estimation signals, the supervisor determines the vehicle driving situation about the lateral stability and rollover prevention. The control algorithms determine a desired yaw moment for lateral stability and a desired longitudinal force for the rollover prevention. In order to apply the control inputs, the coordinator determines a brake and active front steering inputs optimally based on the current status of the subject vehicle. To improve the reliability and to reduce the operating load of the proposed control algorithms, a multi-core ECU platform is used in this system. For the evaluation of this system, a closed loop simulations with driver-vehicle-controller system were conducted to investigate the performance of the proposed control strategy.

• 제어로봇시스템학회논문지
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• 제17권10호
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• pp.967-982
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• 2011

This paper presents a FTNCS (Fault-Tolerant Networked Control System) that can tolerate control surface failure and packet delay/loss in an UAV (Unmanned Aerial Vehicle). The proposed method utilizes the benefits of self-diagnosis by smart actuators along with the control allocation technique. A smart actuator is an intelligent actuation system combined with microprocessors to perform self-diagnosis and bi-directional communications. In the event of failure, the smart actuator provides the system supervisor with a set of actuator condition data. The system supervisor then compensate for the effect of faulty actuators by re-allocating redundant control surfaces based on the provided actuator condition data. In addition to the compensation of faulty actuators, the proposed FTNCS also includes an efficient algorithm to deal with network induced delay/packet loss. The proposed algorithm is based on a Lagrange polynomial interpolation method without any mathematical model of the system. Computer simulations with an UAV show that the proposed FTNCS can achieve a fast and accurate tracking performance even in the presence of actuator faults and network induced delays.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.143-146
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• 1997

In this paper, we propose a fuzzy-supervised nonlinear H$_{\infty}$ controller which guarantees the robustness and has exact tracking performance for robot manipulator with system parameter uncertainty and exogenous disturbance, The proposed controller which is based on robotic H$_{\infty}$ controller has fuzzy supervisor which decides the optimal control input weighting value through fuzzy making-decision process. Owing to the fuzzy supervisor, The proposed controller can take the optimal control input. Then, we will apply the proposed controller to rigid robot manipulator to verify the performance of our controller.r.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1998년도 춘계학술발표회논문집(1)
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• pp.321-328
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• 1998

A controller and sensor fault tolerant system jot a steam generator is designed with fuzzy logic. A structure of the : proposed fault tolerant redundant system is composed of a supervisor and two fuzzy weighting modulators. A supervisor alternatively checks a controlled and a sensor induced performances to identify Which Part, a controller or a sensor, is faulty. In order to analyze controller induced performance both an error and a charge in error of the system output an chosen as fuzzy variables. The fuzzy logic jot a sensor induced performance uses two variables : a deviation between two sensor outputs and its frequency, Fuzzy weighting modulator generates an output signal compensated for faulty input signal. Simulations show that the : proposed fault tolerant control scheme jot a steam generator regulates welt water level by suppressing fault effect of either controllers or sensors. Therefore through duplicating sensors and controllers with the proposed fault tolerant scheme, both a reliability of a steam generator control and sensor system and that of a power plant increase even mote.

• 대한전기학회논문지
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• 제35권12호
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• pp.541-554
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• 1986

This paper presents the results of driving performance analysis of permanent magnet synchronous motor using a microprocessor based control system. The system consists of three phase power transistor inverters, three phase controlled rectifier, three central processing units, and sensors. The three CPUs are, respectively, used to generate PWM control signals for the inverter generating three phase sine wave, to generate the gate control signals for firing the converter, and to supervise other two CPUs. The supervisor is used to compute PI control algtorithm to three phase reference sine wave for the inverter. It is also used to maintain a constant voltage frequency ratio for the converter operating as a constant torque controller. The inverter CPU retrieves precomputed PWM patterns from look up tables because of computation speed limitations found in almost available microprocessors. The converter CPU also retrieves precomputed gate control patterns from another look-up tables. For protecting the control ststem from any damage by extraordinary over currents, the supervisor receives the data from current sensor, CT, and break down the CB to isolate the circuits from source. A resolver has a good performance characteristics of overall speed range, especially on low speed range. Therefor the speed control accuracy is impoved. The microprocessor based PM synchronous motor control system, thus, has many advantages such as constant torque characteristics, improvement of wave, limitation on extraordinary over currents, improvement of speed control accuracy, and fast response speed control using multi-CPU and look-up tables.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1995년도 춘계공동학술대회논문집; 전남대학교; 28-29 Apr. 1995
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• pp.193-200
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• 1995

A shop floor control system(SFCS), a central part of agile manufacturing, performs the production activities required to fill orders. In order to effectively control these activities, CSCW (computer supported cooperative work) is adopted where a supervisor does not exist. In this paper, we define functional perspective of CSCW-based shop floor control using planning, scheduling, and execution functions. In particular, we focus on an execution model that can coordinate the planning and scheduling functions. Execution can be defined informally as a function that downloads and performs a set of scheduled tasks. Execution is also responsible for identifying and resolving various errors whether they come from hardware or software. The purpose of this research is to identify all the execution activities and solving techniques under the assumptions of CSCW-based heterarchical control architecture. This paper also proposes a classification scheme for execution activities of CSCW-based heterarchical control architecture. Petri-nets are used as a unified framework for modeling and controlling execution activities. For solving the nonexistence of a supervisor, A negotiation-based solution technique is utilized.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.585-588
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• 1997

This paper presents a construction method of logic-based switching control system which operates in widely changing environments. The logic-based switching controller is composed of a family of candidate controllers together with a supervisor. The system does not require any identification schemes of environments. Switching from one candidate controller to another is carried out based on monitoring the output of the system. The basic ideas of adaptation are as follows: (1)each candidate controller is prepared for each environment in advance; (2)the supervisor applies a sequence of speculative controls to a plant with candidate controllers just after the control has started and just after the change of the environment has been detected. It is important that each candidate controller can keep the system stable during a sequence of speculative controls, and the most appropriate candidate controller for the environment to which the system is exposed can be selected before the last speculative control is ended. An application to an antiskid braking system clarifies the effectiveness of the proposed method.

• 대한산업공학회지
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• 제25권1호
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• pp.87-99
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• 1999

A shop floor control system(SFCS) performs the production activities required to fill orders. In order to effectively control these activities, the autonomous agent-based heterarchical shop floor control architecture is adopted where a supervisor does not exist. In this paper, we define functional perspective of the heterarchical shop floor control using planning, scheduling, and execution modules. In particular, we focus on an execution module that can coordinate the planning and scheduling modules and a general execution module that easily can be modified to execute the other equipment. The execution module can be defined informally as a module that downloads and performs a set of scheduled tasks. The execution module is also responsible for identifying and resolving various errors whether they come from hardware or software. The purpose of this research is to identify all the execution activities and solving techniques under the assumptions of the heterarchical control architecture. And we model the execution module in object-oriented modelling technique for generalization. The execution module modeled in object-oriented concept can be adopted to the other execution module easily. This paper also proposes a classification scheme for execution activities of the heterarchical control architecture. Petri-nets are used as a unified framework for modeling and controlling execution activities. For solving the nonexistence of a supervisor, a negotiation-based solution technique is utilized.

• 한국산학기술학회논문지
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• 제16권8호
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• pp.5314-5324
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• 2015

본 연구는 종합 병원 간호사들의 직무 스트레스와 직무만족도와의 관련성을 규명하고자 경북지역의 3개 종합병원에 근무하고 있는 간호사 312명을 대상으로 2013년 2월 25일부터 3월 16일까지의 기간 동안에 구조화된 자기기입식 설문지(self-administered questionnaire)를 사용한 설문조사를 실시하였다. 연구결과, 조사대상 간호사들의 직무만족도는 업무요구도가 낮은 군보다 높은 군에서, 업무의 자율성, 상사 및 동료의 지지도가 높은 군보다 낮은 군에서 유의하게 낮았다. 또한 직무만족도는 업무의 요구도와 유의한 음의 상관관계를 보였으나, 업무 자율성, 상사 및 동료의 지지도와는 유의한 양의 상관관계를 보였다. 로지스틱 회귀분석 결과, 직무만족도가 낮은 군에 속할 위험비는 업무의 요구도가 낮은 군보다 높은 군에서, 업무의 자율성, 상사 및 동료의 지지도가 높은 군보다 낮은 군에서 유의하게 증가하였다. 위계적 다중회귀분석 결과, 직무만족도에 영향을 미치는 요인으로는 학력, 근무부서, 업무에 대한 만족도, 간호직 선택 동기 및 이직경험, 직무스트레스 내용(업무의 요구도, 업무 자율성, 상사의 지지도)이 유의한 변수로 선정 되었으며, 특히 직무스트레스 내용이 투입됨으로서 직무만족도에 대한 설명력을 크게 증가시켜 직무만족도는 직무스트레스 내용(업무의 요구도, 업무의 자율성, 상사 및 동료의 지지도)과 밀접한 관련성이 있음을 시사하고 있다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.281-286
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• 1992

This paper describes a duplexed process control system for a boiler-turbine system of power plant, which is composed of supervisor, controller, and simulater subsystems. Its embeded POL(Problem oriented language) as a structured control language enables this system to do a real-time distributed control and fault diagnosis by simple programming with the actual implementation of advanced control algorithms such as PID autotuning and GPC, etc, the performance of overall system has been greatly enhanced.