• International Journal of Control, Automation, and Systems
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• v.5 no.1
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• pp.86-92
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• 2007

In this paper, we first establish $D_L$-admissibility and $D_R$-admissibility conditions for singular systems. The admissibility conditions expressed as Lyapunov type inequalities extend the existed results of normal systems to singular systems. As special cases the admissibility conditions of the continuous-time and the discrete-time singular systems can be obtained directly. The results established in this paper can be applied to solve the problems of eigenvalue assignment, regional pole-placement and robust control etc.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.11
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• pp.1155-1164
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• 2008

Supervisory control theory, which was first proposed by Ramadge and Wonahm, is a well-suited control theory for the control of complex systems such as semiconductor manufacturing systems, automobile manufacturing systems, and chemical processes because these are better modeled by discrete event models than by differential or difference equation models at higher levels of abstraction. Moreover, decentralized supervisory control is an efficient method for large complex systems according to the divide-and-conquer principle. Decentralized supervisors cannot observe the events those of which occur only within the other supervisors. Therefore decentralized supervisors can be designed according to supervisory control theory under partial observation. This paper presents a solution and a design procedure of supervisory control problem (SCP) for the case of decentralized control and SCP under partial observation (SCPPO). We apply the proposed design procedure to an experimental CIM Testbed. And we compare and analyze the designed decentralized supervisors and partially observed supervisors.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.12
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• pp.998-1003
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• 2002

As nonholonomic dynamic systems have constraints imposed on motions that are not integrable, i.e., the constraints cannot be written as time derivatives of some functions of generalized coordinates, advanced techniques are needed for their control. In this paper, a sliding mode tracking control for nonholonomic dynamic systems is proposed. By introducing a general scheme of coordinate transformation, the state of nonholonomic systems is mapped into a bounded space and a robust controller for dynamic models of nonholonomic systems with input disturbances is designed using sliding mode control scheme. Simulation results of tacking control for a nonholonomic mobile robot with two actuated wheels are provided to show the effectiveness of the proposed controller.

• Journal of the Korean Institute of Intelligent Systems
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• v.5 no.4
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• pp.87-100
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• 1995

In order to control systems which contain nonlinearities of uncertainties, control strategies must deal with the effects of them. Since most of control methods based on system mathematical models have been mainly developed focused on stability robustness against nonlinearities or uncertainties under the assumption that controlled systems are linear time invariant, they have certain amount of limitations to smartly improve the transient responses of systems disturbed by nonlinearities or uncertainties. In this paper, a nonlinear fuzzy PID control method is suggested which can stably improve the transient responses of systems disturbed by nonlinearities, as well as systems whose mathematical characteristics are not perfectly known. Although the derivation process is based on the design process similar to general fuzzy logic controller, resultant control law has analytical forms with time varying PID gains rather than linguistic forms, so that implementation using common-used versatile microprocessors cna be achieved easily and effectively in real-time control aspect.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.3-9
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• 2008

Recently, the plant industries are being activated and plant control systems use various technologies. Because the optimized design for the plants is very important for the reducing of operation and maintenance costs, automatic control systems become more important. Plant control systems consist of the master controller, the plant networks, the programming environment for engineering, monitoring software and the field devices. The control systems should have reliability, availability and safety. Modular architecture of hardware and software makes flexible configuration of the control systems. Each component should have diagnostic functions. It follows industrial standards and makes open systems. Open systems increase accessibility against the data which is distributed in the plants. The controllers including processor and communication modules use the up-to-date technology. They have real time and fault tolerant function by duplicating processors or networks. It also enables to make the distributed control systems. The distributed architecture makes more scalable main control system. Automatic control systems can be operated with better performance. In this paper, we analyzed the requirements of the seawater desalination plants and made some consideration facts for developing the optimized controller. Also we described the design concept of the main controller, which consists of several modules. We should validate and complement the design for the reliability and better performance.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1818-1819
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• 2011

Turbine control system and excitation system have close relationship in the dynamic and real power system. Turbine control systems control the active power of generator and excitation systems control the voltage and reactive power of generator. The several sensors' characteristics in turbine control systems and excitation systems were reviewed.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.1
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• pp.13-23
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• 2004

There are several kinds of error factors in control system design. All error factors must be analysed before designing the control system. Therefore, each error factor must be compensated and eliminated completely. Systems Engineering can solve these error factors. In this paper, systems engineering approach on control system design are studied under model based systems engineering with RDD-100, Matlab-Simulink. Systems Engineering shall be used in defense development from control system design to system development.

• International Journal of Computer Science & Network Security
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• v.24 no.8
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• pp.43-53
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• 2024

Access control systems are used to control the access of people to assets. In practice, assets are either tangible (e.g. goods, cash, etc.) or data. In order to handle tangible assets, a person must physically access the space in which the assets are located (e.g. a room or a building). Access control systems for this case have been known since antiquity and are based either on mechanical locks or on certificates. In the middle of the 20th century, systems based on electromagnetic phenomena appeared. In the second half of the same century, the need to control access to data also arose. And since data can also be accessed via a computer network, it was necessary to control not only the access of persons to areas with data storage, but also to control the electronic communication of persons with these storage facilities. The different types of the above systems have developed separately and more or less independently. This paper provides an overview of the current status of different types of systems, showing that these systems are converging technologically based on the use of electronics, computing and computer communication. Furthermore, the terminology and architecture of these systems is expanded in the article to allow a unified description of these systems. The article also describes the most common types of access control system configurations.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.4
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• pp.413-419
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• 2009

A decentralized adaptive control method is proposed for large-scale systems with unknown time-delayed nonlinear interconnections unmatched in control inputs. It is assumed that the time-delayed interaction terms are bounded by unknown nonlinear bounding functions. The nonlinear bounding functions and uncertain nonlinear functions of large-scale systems are compensated by the function approximation technique using neural networks. The dynamic surface control method is extended to design the proposed memoryless local controller for each subsystem of uncertain nonlinear large-scale time delay systems. Therefore, although the interconnected systems consist of a large number of subsystems, the proposed controller can be designed simply. We prove that all the signals in the total closed-loop system are semiglobally uniformly bounded and the control errors converge to an adjustable neighborhood of the origin. Finally, an example is given to demonstrate the effectiveness and applicability of the proposed scheme.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.446-449
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• 1997

We propose a control law in discrete time domain of the bilateral feedback teleoperation system using neural network and the reference model type of adaptive control. Different from traditional teleoperation systems, the transmission time delay irregularly changes. The proposed control method controls master and slave systems through identification of master and slave models using neural networks.