• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.8
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• pp.405-411
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• 2000

When faults occur in transmission lines, the classification of faults is very important. If the fault is HIF(High Impedance Fault), it cannot be detected or removed by conventional overcurrent relays (OCRs), and results in fire hazards and causes damages in electrical equipment or personal threat. The fast discrimination of fault needs to effective protection and treatment and is important problem for power system protection. This paper propolsed the fault detection and discrimination algorithm for LIFs(Low Impedance Faults) and HIFs(High Impedance Faults). This algorithm uses artificial neural networks and variation of 3-phase maximum currents per period while faults. A double lines-to-ground and line-to-line faults can be detected using Neural Network. Also, the other faults can be detected using the value of variation of maximum current. Test results show that the proposed algorithms discriminate LIFs and HIFs accurately within a half cycle.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.856-858
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• 1999

The analysis of distribution line faults is essential to the proper protection of power system. A high impedance fault(HIF) dose not make enough current to cause conventional protective device. It is well known that undesirable operating conditions and certain types of faults on electric distribution feeders cannot be detected by using conventional Protection system. This paper describes an algorithm using neural network for pattern recognition and detection of high impedance faults. Wavelet transform analysis gives the time-scale information. Time-scale representation of high impedance faults can detect easily and localize correctly the fault waveform.

• International Journal of Computer Science & Network Security
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• v.21 no.8
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• pp.149-160
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• 2021

One of the most important inventions and developments in the digital world today is the healthcare system based on blockchain technology. Healthcare is an important field that requires the application of security mechanisms due to the sensitivity of patient data. The association of blockchain with healthcare contributed to achieving better security mechanisms than the traditional approach. The new approach operates in a decentralized system, which in turn, improves security in the healthcare environment. Consequently, blockchain technology has emerged as one of the most crucial solutions to security violations and challenges in the healthcare industry. This paper provides a comprehensive review of several experts' recent protection and detection approaches in this domain. It is also imperative to note that the paper focuses only on the recent techniques that have been published during 2017-2020. The sophisticated procedures have been investigated and discussed in terms of similarities and differences to highlight the significance of the protection needed to secure the healthcare environment.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.8
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• pp.59-66
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• 2008

Korea Electric Power Research Institute in charge of the power IT project "Development of Prototype for Advanced Substation Automation System based on the Digital Control Technology" is performing system verification. Breaker Failure protection IED can operate protection activity by communicating with other IEDs such as T/L IED, owing to IEC 61850 international standard and digital substation automation system. Accordingly, IED testing process should be changed from the conventional way by electrical contact test on individual IED to system based testing method by network communication. This paper describes how to test BF IED based on substation automation system and testing procedures using UML, which is used to implement S/W design.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.3
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• pp.101-113
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• 2006

This study is intended to provide more secure contents authentication and user authentication by applying public key algorithm and hardware binding to the DRM system. The proposed system is capable of protecting distributed contents and copyrights as well as resetting any interoperability issues among those involved in transparent and secure contents distribution. The proposed algorithm also affords transparency in the DRM distribution system and protection from unauthorized distribution.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.165-166
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• 2007

This paper proposes an algorithm to improve the anti-theft function of the CAR_AV using the CAN(Controller Area Network) communication between CAR AV and cluster. Compare to the typical anti-theft algorithms like security code entering, the proposed one is more secure in most cases. The proposed algorithm is suitable for the recent automobile that employ the CAN network as the communication channel between their devices.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.262-269
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• 1998

In case the fault occurs in AC power supply network, protective relaying system must selectively detect line-to-line/ground fault and immediately cut off the power flow into the fault location for guaranteeing the safety of people, electric vehicle and ground installation etc. It is the most important point in power system operation to minimize the fault duration by rapid trip scheme and accurate estimation of the fault location. In this paper, we analyze the load characteristics of each vehicle, perform the fault analysis of AC power supply network using AT current-ratio method. The result shows its usefulness.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.468-468
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• 2000

In our laboratory, the control aspects are investigated in the photovoltaic power generation systems (PV systems). The PV system is very good for earth environment, but if it connects to power network system, many problems are raised (protection, voltage, harmonics etc.). In this paper, we present the result of the basic studies for the building of the PV system that amplifies the electric energy obtained from the solar cell. We consider electronic circuits in order to protect the PV system from power surge induced by lightning and also design an electronic circuit in order to detect defaults in the power network system. We would like to integrate these circuits into the PV system by considering its control equipment build by 8-bit microcomputer using various control theory (fuzzy, neural network etc.).

• Convergence Security Journal
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• v.8 no.4
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• pp.21-30
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• 2008

This study researched into the method that allows only the certified user and computational engineer to possibly use network resources and computing resources by implementing the system of the intensified certification and security based on LDAP(Lightweight Directory Access Protocol) directory service, that copes with incapacitation in security program due to making the security program forcibly installed, and that can correctly track down the industrial-technology exporter along with applying the user-based security policy through inter-working with the existing method for the protection of industrial technology. Through this study, the intensified method for the protection of industrial technology can be embodied by implementing the integrated infra system through strengthening the existing system of managing the protection of industrial technology, and through supplementing vulnerability to the method for the protection of industrial technology.

• Transactions on Electrical and Electronic Materials
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• v.18 no.3
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• pp.169-175
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• 2017

A safe and reliable protection system in distribution networks, specifically, those hosting distribution generation units, needs a robust over-current protection scheme. To avoid unintentional DG disconnection during fault conditions, a protection system should operate quickly and selectively. Therefore, to achieve this aim, satisfying coordination constraints are important for any protection scheme in distribution networks; these pose a challenging task in interconnected and large-scale networks. In this paper, a new coordination strategy, based on the same non-standard time-current curve for all relays, in order to find optimal coordination of directional over-current relays, is proposed. The main aim is to reduce violations, especially miscoordination between pair relays. Besides this, the overall time of operation of relays during primary and backup operations should be minimized concurrently. This work is being tackled based on genetic algorithms and motivated by the heuristic algorithm. For the numerical analysis, to show the superiority of this coordination strategy, the IEEE 30-bus test system, with a mesh structure and supplemented with distributed generation, is put under extensive simulations, and the obtained results are discussed in depth.