• 경영과학
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• 제21권1호
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• pp.57-76
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• 2004

The development of informational technology has lead to a sharp change in not only the existing way of operations and management, but the way of human life or thinking as well. Those shifts of the paradigm in information technology have also affected Individuals to the organizational structure. A series of unexpected problems was, however, accompanied by the advance in informational technology, which had broaden its own area of application. Those problems include the losses of property or data the malfunction of systems and their wastefulness would result in, continuous increases in computer crimes, reliability and efficiency of the functional process with the development of information systems, such as the processing problems of inaccurate data, economical issues, and subjects related to safety, as interruptions of privacy, which would result from lots of one's exposure to the drains of personal information. Accordingly, Auditors' roles of information systems, for now, is more important than anything else in that they are responsible for the objective assessment of relevance and effectiveness of internal control systems under the environment of information systems. The objective of the study is, so as to obtain safety of information systems： First, to provide data to line-design internal control systems after finding internal control factors to prevent and eliminate the risks of information systems. Second, to evaluate the priorities of internal control factors with their effective management being considered as the key to settle the problems of risks of information systems. Third, to discriminate what factors affect In evaluating the relative degrees of Importance of internal control factors.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.248-251
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• 1992

In this paper, the RedMAP, i.e. a redundant Mini-MAP system for high reliability is proposed. Redundancy is implemented for LLC, MAC, and Physical layer of ISL-Mini -MAP. The detection of error of the network, the broadcasting of the error event, and the network change sequence are three major functions for the dualized Mini-MAP system. The abnormal operation of the network is mainly detected indirectly with the function of the TBC( token bus controller). The time delay to be required for the change of the networks must be minimized. With the RedMAP, we can achieve successful transmission only with short additional recovery time.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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• pp.100-103
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• 1999

In this paper, a method for the efficient implementation of the PICNET network configurator for a distributed control system(DCS) is proposed. The network configurator is composed of the time parameter estimator and the period scheduler, the file generator. The main role of network configurator estimates time parameter, the pre-run time scheduling of the user input and make the period transmission table for operating the PICNET based distributed control system.

• International Journal of Control, Automation, and Systems
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• 제2권1호
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• pp.15-22
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• 2004

Some recent advances in stability and optimality for the nonlinear receding horizon control (NRHC) or the nonlinear model predictive control (NMPC) are assessed. The NRHCs with terminal conditions are surveyed in terms of a terminal state equality constraint, a terminal cost, and a terminal constraint set. Other NRHCs without terminal conditions are surveyed in terms of a control Lyapunov function (CLF) and cost monotonicity. Additional approaches such as output feedback, fuzzy, and neural network are introduced. This paper excludes the results for linear receding horizon controls and concentrates only on the analytical results of NRHCs, not including applications of NRHCs. Stability and optimality are focused on rather than robustness.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1558-1562
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• 2005

This paper describes the design and implementation of a wireless home network system using Home Network Control Protocol (HNCP) called the wireless HNCP home network system. For wireless interfaces of HNCP, IEEE 802.11b and IEEE 802.15.4 standard protocols are considered. With the implementation of the wireless HNCP home network system, a simple analysis about coexistence between IEEE 802.11b and IEEE 802.15.4 is achieved. Through the implemented wireless HNCP home network system and the analytical results about the coexistence between both two different wireless protocols, the feasibility of the wireless HNCP home network system is shown.

• 한국멀티미디어학회논문지
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• 제18권11호
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• pp.1342-1350
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• 2015

Due to rapid development of mobile device technologies, the mobile banking through Internet has become a major service of banking information systems as a security-critical information systems. Recently, lots of mobile banking information systems which handle personal and transaction information have been exposed to security threats in vulnerable security control and management processes, mainly software systems. Therefore, in this paper, we propose a process model for software security improvements in mobile banking information system by application of fault tree analysis(FTA) and failure modes and effects analysis(FMEA) on the most important activities such as 'user authentication' and 'access control' and 'virus detection and control' processes which security control and management of mobile banking information systems are very weak.

• Journal of international Conference on Electrical Machines and Systems
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• 제2권2호
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• pp.184-189
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• 2013

This paper proposes a method for improving the performance of a position sensorless control system for a slotless surface permanent magnet synchronous motor (SPMSM) in a very low-speed region. In position sensorless control based on a motor model, accurate motor parameters are required because parameter errors would affect position estimation accuracy. Therefore, online parameter identification is applied in the proposed system. The error between the reference voltage and the voltage applied to the motor is also affect position estimation accuracy and stability, thus it is compensated to ensure accuracy and stability of the sensorless control system. In this study, two voltage error compensation methods are used, and the effects of the compensation methods are discussed. The performance of the proposed sensorless control method is evaluated by experimental results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1581-1585
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• 2005

This paper describes the design and implementation of a XCP (Xeline Control Protocol) network system. XCP is an information oriented protocol which delivers information with high reliability according to the predefined rule. The XCP network system is implemented with partly hardware and partly software based on the power line communication(PLC) environment. A network management tool which interacts with devices is also developed. In order to verify the feasibility of the proposed architecture, the implemented XCP network system is evaluated using a lighting control system.

• IEIE Transactions on Smart Processing and Computing
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• 제5권1호
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• pp.22-28
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• 2016

Multi-loop control of a boost converter needs a current-sensing circuit to detect the inductor current. Current sensorless multi-loop control reduces the cost, size and weight of the converter. The Luenberger observer (LO) is widely used to estimate the inductor current for current sensorless control of a switching converter. However, the design of the LO-based sensorless multi-loop control has not been well presented, so far. In this paper, a closed-loop characteristics evaluation method is proposed to design an LO-based current sensorless multi-loop control for boost converters. Simulations show evaluations of the closed-loop characteristics. Practical experiments on a digital processor confirm the simulations.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.346-349
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• 1996

In this paper development of a CAD of control systems is introduced which enables us to do not only analysis of control systems, design of controllers but also real-time implementation of controllers. By utilizing this software, the control engineer is able to repeat the procedure of modification of controllers and experiments without recompile to attain better performance. The software also offers the facility to update the parameters of controllers without stopping real-time control, which helps on-line tuning of controllers. If some parameters of the controller is changed on-line, the control input may change discontinuously. It has serious effect on the control systems. A method for on-line tuning of state feedback controller with state observer is proposed and verified through the experiment with an inverted pendulum.