• Journal of Korea Society of Digital Industry and Information Management
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• v.16 no.4
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• pp.29-42
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• 2020

SCADA (Supervisory Control and Data Acquisition) systems for remote monitoring, data acquisition and control are applied to major industrial infrastructures including power, water and railroad. Recently, there are many researches on key management scheme for secure communication due to change to the open network environment. These systems are located at far distances and are connected to the main control center through various types of communication methods. Due to the nature of these systems, they are becoming the significant targets of cyber attack. We propose an efficient key management scheme which is established on ID-based cryptosystem without an expensive computation on MTU (Master Terminal Unit), Sub-MTU, and RTU (Remote Terminal Unit). The proposed method is secure and effective in key management among multiple legitimate devices.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.674-677
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• 1988

SCADA (Supervisory Control And Data Acquisition) system for control and supervision of power system is now being operated in KEPCO with high performance. But the performance of RGS(Report Generating System) is comparatively insufficient because the SCADA system was produced for special purpose performing in real time. Therefore, we have performed this study applied for the purpose of processing the statistic data of power network and improving facilities and availabilities of the system.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.356-356
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• 2000

For irregular nonlinear systems, switching controlk form is proposed recently. This control law is designed to overcome the singularities through the scheme that switches between an approximate tracking law close to the singularities, and an exact tracking law away from the singularities. But, that form has problems which may break the system's stability through unstable control input value at switching procedure. In this paper, We propose new switching control law which supervises approximate tracking control law and exact tracking control law by fuzzy rules to overcome unstability problem in switching procedure.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.562-566
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• 1989

The selection of control and indication joints effects the supervisory and control scope of SCADA system. This paper proposes the point selection for the no-man substation. The points of no-man s/s are 3-4times as many ad points of man-substation. And also the considering points are described to implement total automation.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.4
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• pp.396-399
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• 2009

This paper presents the notion of time-coobservability as a core condition far the existence of a decentralized supervisor achieving a given language specification in a timed discrete event system (TDES). A TDES is modeled by the framework of Brandin & Wonham [5], and the decentralized supervisory control architecture presented is extended from the untimed architecture of Yoo & Lafortune [1]. To develop the time-coobservability of a language specification, specifically this paper presents the C&P time-coobservability and D&A time-coobservability in the consideration of the event tick and forcing mechanism of decentralized supervisors.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.888-894
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• 2015

This paper presents a unified model based assessment framework to quantify threats and vulnerabilities associated with control systems, especially in the SCADA (Supervisory Control and Data Acquisition) system. In the past, this system was primarily utilized as an isolated facility on a local basis, and then it started to be integrated with wide-area networks as the communication technology would make rapid progress. The introduction of smart grid, which is an innovative application of digital processing and communications to the power grid, might lead to more and more cyber threats originated from IT systems. However, an up-to-date power system often requires the real-time operations, which clearly implies that the cyber security would turn out to be a complicated but also crucial issue for the power system. In short, the purpose of this paper is to streamline a comprehensive approach to prioritizing cyber security risks which are expressed by the combination of threats, vulnerabilities, and values in the SCADA components.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.1020-1025
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• 2007

EMS(energy management system) and SCADA(supervisory control and data acquisition) systems are used for reliable and efficient operation of electrical power systems. Various functions in EMS such as power flow, contingency analysis, security analysis essentially need accurate data set for reliable operation. State estimation can be a tool for providing these data. In this paper, programs for observability analysis and bad data processing are developed. Fundamental algorithms are introduced and validity of the proposed techniques is inspected with test cases.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.6
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• pp.1293-1308
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• 2014

The cause of privacy extrusion in credit card company at 2014 is usage of the original data in test system. By Electronic banking supervision regulations of the Financial Supervisory Service and Information Security business best practices of Finance information technology (IT) sector, the data to identify the customer in the test system should be used to convert. Following this guidelines, Financial firms use converted customer identificaion data by loading in test system. However, there is some risks that may be introduced unintentionally by user mistake or lack of administrative or technical security in the process of testing. also control and risk management processes for those risks did not studied. These situations are conducive to increasing the compliance violation possibility of supervisory institution. So in this paper, we present and prove the process to eliminate the compliance violation possibility of supervisory institution by controlling and managing the unidentified conversion customer identification data and check the effectiveness of the process.

• Journal of the Earthquake Engineering Society of Korea
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• v.9 no.5 s.45
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• pp.41-52
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• 2005

Using the variable control gain scheme on the basis of fuzzy-based decision-making process, Fuzzy supervisory control (FSC) technique exhibits better control performance than linear control technique with one static control gain. This paper demonstrates the effectiveness of the FSC technique by evaluating the robust performance of the FSC technique under the presence of uncertainties in the models and the excitations. Robust performance of the FSC system is compared with that of optimally designed LQG control system for the benchmark cable-stayed bridge presented by Dyke et al. Parameter studies on the robust performance evaluation are carried out by varying the stiffness of the bridge model as well as the magnitudes of several earthquakes with different frequency contents. From the comparative study of two control systems, FSC system shows the enhanced control performance against various magnitudes of several earthquakes while maintaining lower level of power required for controlling the bridge response. Especially, FSC system clearly guarantees the improved robust performance of the control system with stable reduction effects on the seismic responses and slight increases in total power and stroke for the control system, while LQG control system exhibits poor robust performance.

• Journal of Satellite, Information and Communications
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• v.12 no.4
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• pp.50-55
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• 2017

In this paper, the design of the RF system monitoring and control system of KUS (KASS: KASS Uplink Station) which constitutes KASS (Korea Augmentation Satellite System) is described. The Korean satellite calibration system is named KASS and aims to develop the SBAS system of the APV-1 level SoL service level and the CAT-1 test operation technology. Software and hardware development environment, function and algorithm of supervisory control device, structure of supervisory control device, and user interface were designed to implement KUS / RFS monitoring control device. We have secured the stability and reliability of the system by using the monitoring and control system design of the COMS (Communication Ocean & Meteorological Satellite) and the Korea Satellite 5A / 7 control system, which has already been used for the design of the surveillance control system. In addition, we have made it possible to provide the user interface according to the actual operator's request more conveniently.