• Journal of Institute of Control, Robotics and Systems
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• v.4 no.2
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• pp.246-255
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• 1998

This paper presents a novel method for real-time malfunction detection of plasma etching process using EPD signal traces. First, many reference EPD signal traces are collected using monochromator and data acquisition system in normal etching processes. Critical points are defined by applying differentiation and zero-crossing method to the collected reference signal traces. Critical parameters such as intensity, slope, time, peak, overshoot, etc., determined by critical points, and frame attributes transformed signal-to symbol of reference signal traces are saved. Also, UCL(Upper Control Limit) and LCL(Lower Control Limit) are obtained by mean and standard deviation of critical parameters. Then, test EPD signal traces are collected in the actual processes, and frame attributes and critical parameters are obtained using the above mentioned method. Process malfunctions are detected in real-time by applying SPC(Statistical Process Control) method to critical parameters. the Real-time malfunction detection method presented in this paper was applied to actual processes and the results indicated that it was proved to be able to supplement disadvantages of existing quality control check inspecting or testing random-selected devices and detect process malfunctions correctly in real-time.

• Journal of Drive and Control
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• v.16 no.1
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• pp.22-28
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• 2019

This paper develops ABS braking real - time simulator to develop vehicle braking system by simulation. Recently, real-time simulation is widely used in the development of vehicles to decrease development time. In the field of electronic braking, real-time simulation is actively underway. In order to simulate electronic braking model in real time, a vehicle model, a hydraulic model, and a control S/W model are required. These models must be calculated in one platform. Therefore, in this paper, a vehicle model composed of CarSim and a hydraulic model composed of SimulationX using S/W in actual ABS controller was developed as a Simulink model base and linked with Matlab real time model. Using this real-time model, design effects of the electronic braking controller were simulated according to road surface condition to verify its operability.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.109-112
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• 1997

A Discrete Event Dynamic System is a system whose states change in response to the occurrence of events from a predefined event set. A major difficulty in developing analytical results for the systems is the lack of appropriate modeling techniques. This paper proposes the use of Real-time Temporal Logic as a modeling tool for the modeling and control of fixed-time traffic control problem which by way of a DEDS. The Real-time Temporal Logic Frameworks is extended with a suitable structure of modeling hard real-time constraints. Modeling rules are developed for several specific situations. It is shown how the graphical model can be translated to a system of linear equations and constraints.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.2
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• pp.75-89
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• 2003

Media Access Control (MAC) Protocol in IEEE 802.11 Wireless LAN standard supports two types of services, synchronous and asynchronous. Synchronous real-time traffic is served by Point Coordination Function (PCF) that implements polling access method. Asynchronous nonreal-time traffic is provided by Distributed Coordination Function (DCF) based on Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol. Since real-time traffic is sensitive to delay, and nonreal-time traffic to error and throughput, proper traffic scheduling algorithm needs to be designed. But it is known that the standard IEEE 802.11 scheme is insufficient to serve real-time traffic. In this paper, real-time traffic scheduling and admission control algorithm is proposed. To satisfy the deadline violation probability of the real time traffic the downlink traffic is scheduled before the uplink by Earliest Due Date (EDD) rule. Admission of real-time connection is controlled to satisfy the minimum throughput of nonreal-time traffic which is estimated by exponential smoothing. Simulation is performed to have proper system capacity that satisfies the Quality of Service (QoS) requirement. Tradeoff between real-time and nonreal-time stations is demonstrated. The admission control and the EDD with downlink-first scheduling are illustrated to be effective for the real-time traffic in the wireless LAN.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.13-16
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• 1989

The paper, introduce the real time controller Design method of heavy load 6-DOF motion simulator. And also, introduce the Geometric design of 6-DOF Motion generation, real time control A algorithm and the configuration method of real time controller H/W and S/W.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.6 s.165
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• pp.922-930
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• 1999

This paper describes a new 14-CPU real-time distributed automatic gauge control (AGC) system for POSCO's No. 2 Hot Strip Mill at Pohang Works. The new AGC system has adopted gaugemeter AGC, Monitor AGC, and roll gap disturbance compensators. The computer system for the new AGC system has been developed based on VMEbus computer systems and a commercial real-time operating system. A VMEbus computer system is also used for the position servo control of hydraulic cylinders. All the application programs and input/output signals have been reasonably distributed over the control computer systems for the maximum reliability and effectiveness of the system. The new AGC system has been successfully used for the No. 2 Hot Strip Mill.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1432-1435
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• 1996

This paper obtains maximum allowable delay bounds for stability of network-based control systems and presents a network scheduling method which makes the network-induced delay be less than the maximum allowable delay bound. The maximum allowable delay bounds are obtained using the Lyapunov theorem. Using the network scheduling method, the bandwidth of a network can be allocated to each node and the sampling period of each sensor and controller can be determined. The presented method can handle three kinds of data (periodic, real-time asynchronous, and non real-time asynchronous data) and guarantee real-time transmissions of real-time synchronous data and periodic data, and possible transmissions of non real-time asynchronous data. The proposed method is shown to be useful by examples in two types of network protocols such as the token control and the central control.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.34-34
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• 2000

One of the basic goals, when considering networks for communication in industrial control applications, is the reduction of complexity of related wiring harnesses. In addition, the networking offers the advantages for industrial control applications, such as ease of cabling, ease of changes in the cabling, ease of adding controller modules, etc. CAN (Controller Area Network) is generally applied in car networking in order to reduce the complexity of the related wiring harnesses. These traditional CAN application techniques are modified to achieve the real time communication for the industrial control applications. In this paper, we propose the method of CAN Identifier assignment for Real-Time network system. This method is can be used to scheduling messages on CAN for Real-Time network system. And also, the real-time network system is developed and the proposed moth(Ids are verified experimentally.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.69-72
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• 1999

In this paper, the implementation method for the extending real-time execution in MMS Implementation is proposed. For this, the method of MMS over ATM(Asynchronous Transfer Mode) and IEEE 802.12 network is analyzed. By the analysis of service response time, making the ASIC of encoding and decoding parts are proposed for one of the real time extension in MMS. The main goals of this paper to analyze and propose suitable methods to meet the real time requirements in MMS applied system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.11
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• pp.1637-1645
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• 2004

In remote control of telerobotics equipment, the real-time visual feedback is necessary in order to facilitate real-time control. Because of the network congestion and the associated delays, the real-time image feedback is generally difficult in the public networks like internet. If the remote user is not able to receive the image feedback within a certain time, the work performance may tend to decrease, and it makes difficulties to control of the telerobotics equipment. In this paper, we propose an improved visual feedback scheme over the internet for telerobotics system. The size of a remote site image and its quality are adjusted for efficient transmission. The constructed system has a better real-time update characteristics, and shows a potential for the real-time visual control of the telerobotics system.