• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1155-1157
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• 1999

The UPFC is known to have the ability to control both the real power flow and the reactive power flow. [1],[2] The power flow in the system is heavily related with the system security. [4] This paper deals with the operation of the UPFC to increase the power system security. The concept of the power system security is verified and the index to indicate the power system security level is suggested. And the algorithm to find the optimum operation point of the UPFC improving the system security level is presented.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.4
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• pp.51-59
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• 2009

Many failures are due to incorrectly programmed transactions and data entry errors. System failure causes the loss or corruption of the contents of volatile storage. Although global processing protects data values to detect direct or indirect information effluence, security environments are very important in the recovery management of heterogeneous systems. Although transaction can't control system fault, the restart for the system can cause information effluence by low bandwith. From various faults, it is not easy to maintain the consistency and security of data. This paper proposes recovery management protocols to assure global multilevel secure one-copy quasi-serializability in security environments of heterogeneous systems with replicated data and proves its correctness. The proposed secure protocols guarantee the reliability and security of system when the system fault is happened.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.6
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• pp.145-152
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• 2009

SCADA(Supervisory Control And Data Acquisition) systems are widely used for control and monitoring of critical infrastructures including electricity, gas and transportation. Any compromise in the security of SCADA systems could result in massive chaos and disaster at a national level if a malicious attacker takes the control of the system. Therefore, sound countermeasures must be provided when the SCADA systems are being developed as well as when they are being operated. Unlike general information processing system, SCADA systems have different service responses, communication protocols and network architectures and therefore a different approach should be applied to each SCADA systems that takes into consideration of each system's security characteristics and architectures. In addition, legal basis should be established to ensure the nationwide management of the systems security. This paper examines the vulnerabilites of SCADA systems and proposes action plans to protect the systems against cyber attacks.

• Asia pacific journal of information systems
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• v.9 no.3
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• pp.143-157
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• 1999

EDI is one of the most important information technologies in todays business environment. This study is an exploratory study on the EDI control of Korean companies in their early stage of EDI implementation. The purpose of this study is to examine the impact of EDI controls on the security and usefulness of EDI systems for Korean companies who have adopted EDI. The data of fifty-one Korean companies for financial, manufacturing, and trade industries are collected by the mail survey and interview methods. The level of EDI control is mediocre on the average. The level of EDI security is low while that of EDI usefulness is mediocre. The empirical results show that the EDI controls in general improve the EDI security and usefulness significantly. Especially, the application and security control affect the EDI security significantly while the management, application, and security controls affect the EDI usefulness significantly. The gap between the level and perceived importance of control does not affect the EDI security but decreses the EDI usefulness at the marginal level of significance. The limitation of this study is that only a small number of companies are available for data collection because Korea is in the early stage of EDI implementation.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.701-704
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• 2003

The home network system of ubiquitous computing concept is changing present our home life as more comfortable and safe. Also, it permits that we can connect the home network system and control the appliance which is linked to the home network system without limitation in time and place. But, as other systems that use the public network like the Internet, remote control/monitoring of the home network system that use the Internet includes problems such as user's access which is not admitted and information changing. This paper presents the efficient solution about the security problem that is recognized to important problem of the home network system. Also this paper implements the security of the home network system based on the UPnP (Universal Plug and Play), adding VPN (Virtual Private Network) router that uses the IPsec to the home network system which is consisted of the ARM9 and the Embedded Linux.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.3
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• pp.240-246
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• 1990

The security control can be defined as all control actions and counter-measures to return the operating state of the system to a normal state. In an emergency state, fault clearing and/or overload suppression is enabled as a security control in order to prevent the extension of the fault. In the alert state, counter-measures should be set up in advance for the dangerous points of the system operation in drder to protect the system from expected accidents. In the normal state, the routine scenario is conducted to analyze system state. In the decision-making of the classification of system states, the heuristic and experienced knowledge can be well applied and thus application of expert system to this area attains considerable achievements. In this study, it is attempted to extract empirical rules through heuristic analysis and establish the knowledge base. Finally, the incorporation method with the conventional program packages in proposed. The expert system is designed to select an appropriate method and to perform the corresponding package. The input data can be automatically set up by using the data base. The computation results can be automatically added to the data base.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.5
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• pp.159-166
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• 2010

From public insecurity, access of wealth, alteration of population structure, and changes of security recognition, physical security has been continuously developed and changed. In these days, typical systems for physical security are unmanned security system using telephone network and security equipment, image recognition system using DVR and camera, and access control system by finger print recognition and RFID cards. However, physical security system is broadening its domain towards ICT based convergence with networked camera, biometrics, individual authentication, and LBS services. This paper proposes main technical trends and various security convergences for future physical security services by classifying the security categories into 3 parts; Individual security for personal protection, IT Convergence for large buildings, and Homeland Security for omni-directional security.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.6057-6078
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• 2018

Smart home systems provide a safe, comfortable, and convenient living environment for users, whereby users enjoy featured home services supported by the data collected and generated by smart devices in smart home systems. However, existing smart devices lack sufficient protection in terms of data security and privacy, and challenging security and privacy issues inevitably emerge when using these data. This article aims to address these challenging issues by proposing a private blockchain-based access control (PBAC) scheme. PBAC involves employing a private blockchain to provide an unforgeable and auditable foundation for smart home systems, that can thwart illegal data access, and ensure the accuracy, integrity, and timeliness of access records. A detailed security analysis shows that PBAC could preserve data security against various attacks. In addition, we conduct a comprehensive performance evaluation to demonstrate that PBAC is feasible and efficient.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.6
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• pp.29-35
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• 2005

This paper presents the basic quench protection idea for the HTS(High-Temperature Superconducting) cable. In Korea power system, the transfer capability of transmission line is limited by the voltage stability, HTS cable could be one of the countermeasure to enhance the transfer limit with its higher current capacity and lower impedance[1]. However, the quench characteristic makes not only HTS cable to loss its superconductivity, but also change the impedance of the transmission line and power system operating condition dramatically. This pheonominum threats HTS cable safety as well as power system security, therefore a proper protection scheme and security control counterplan have to be established before HTS cable implementation. In this paper, the quench characteristics of HTS cable for the fault current based on heat balance equation was established and a proper protection method regarding conventional protection system was suggested.

• 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.