• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.438_439
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• 2009

This paper analyzes the undervoltage protection based on the dynamic stability of a PV system at fault conditions. A 3 MW PV system is modeled by Matlab/Simulink. Then, the distribution system interconnected with the PV system is modeled. This paper simulates the various fault types and analyzes the stability of the PV system at fault conditions. It is concluded that the undervoltage protection of the grid-connected PV system in Korea standard needs to be modified based on the results of the stability analysis.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1620-1622
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• 1998

The failure occurs in the system of the underground transmission line, the time of restoration is very long, the damage from stopping power supply is very serious and the cost of restoration is very great. because of these problems, the system and equipment must be protected from every electrical failure by installing protection unit. This study is summarized and compared the effects of configuration method of cable protection device with respect to surges in EHV (Extra High Voltage) underground transmission system.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.2
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• pp.43-52
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• 2008

The galvanic corrosion of a vessel, or systems fitted to minimize the ship's corrosion such as ICCP (Impressed Current Cathodic Protection) system and sacrificial anodes, can lead to significant electrical current flow in the sea. The presence of vessel's current sources associated with corrosion will give rise to detectable electric field surrounding the vessel and can put it at risk from mine threats. For this reason, it is necessary to design corrosion protection systems so that they don't only prevent a hull corrosion but also minimize the electric field signature. In this paper, we describe theoretical backgrounds of underwater electric field signature due to corrosion and corrosion protection system on naval vessels and analysis results of the electric field according to the ship's hull and it's propeller coating damage and ICCP anode displacement.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.3
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• pp.87-109
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• 2016

This study intends to present an effective and efficient development plan about the information protection of medical institutions, by establishing the improvement plan about Personal Information Management System(PIMS) appropriate to the characteristics of medical information focusing on medical institutions generating and using domestic medical information, and doing an empirical study on medical information protection plan. For this, in view of the medical characteristics of the existing Information Security Management System(ISMS), the study presented a study model appropriated to medical institutions based on Personal Information Management Systems index specialized for personal information, and through this, presented the vulnerability diagnosis and vulnerability improvement plan. Based on ISMS index, it designed an improvement index of personal information protection management about each index. The study conducted a survey for executives and employees about PIMS. Accordingly, it presented vulnerability diagnosis items of the current management system indexes from the viewpoint of the people who establish and mange the personal information protection about patients' medical information targeting executives and employees who serve at hospitals and can access medical information.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.11a
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• pp.191-196
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• 1996

The potential value of the Application Specific Integrated Circuits(ASIC's) in safety systems of Nuclear Power Plants(NPP's) is being increasingly recognized because they are essentially hardwired circuitry on a chip, the reliability of the system can be proved more easily than that of software based systems which is difficult in point of software V&V(Verification and Validation). There are two types of ASIC, one is a full customized type, the other is a half customized type. PLD(Programmable Logic Device) used in this paper is a half customized ASIC which is a device consisting of blocks of logic connected with programmable interconnections that are customized in the package by end users. This paper describes the RPS(Reactor Protection System) composed of ASICs which provides emergency shutdown of the reactor to protect the core and the pressure boundary of RCS(Reactor Coolant System) in NPP's. The RPS is largely composed of five logic blocks, each of them was implemented in one PLD, as the followings. A). Bistable Logic B). Matrix Logic C).Initiation Logic D). MMI(Man Machine Interface) Logic E). Test Logic.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.5
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• pp.526-538
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• 2007

Since air quality monitoring data sets are important base for developing of air quality management strategies including policy making and policy performance assessment, the environmental protection authorities need to organize and operate monitoring network properly. Air quality monitoring network of Busan, consisting of 18 stations, was allocated under unscientific and irrational principles. Thus the current state of air quality monitoring networks was reassessed the effect and appropriateness of monitoring objectives such as population protection and sources surveillance. In the process of the reassessment, a GIS-based decision support system was constructed and used to simulate air quality over complex terrain and to conduct optimization analysis for air quality monitoring network with multi-objective. The maximization of protection capability for population appears to be the most effective and principal objective among various objectives. The relocation of current monitoring stations through optimization analysis of multi-objective appears to be better than the network building for maximization of population protection capability. The decision support system developed in this study on the basis of GIS-based database appear to be useful for the environmental protection authorities to plan and manage air quality monitoring network over complex terrain.

• Journal of Korea Multimedia Society
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• v.7 no.7
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• pp.934-943
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• 2004

In this paper, we propose cookie protection-key management system for cookie protection and maintain separate cookie protection-key of each user. We provide integrity, confidentiality, and user authentication of cookie by using registered cookie protection-key and applying encryption techniques. And, we use the technique for hiding the URL of an internal document to a user to minimize the problem of its exposure. When this system is applied to the intranet of an enterprise, it will be able to provide a security to cookie and minimize the problem of internal document exposure by an internal user.

• Resources Recycling
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• v.18 no.4
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• pp.44-51
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• 2009

In order to verify the effect of Surface Coating Anode and Solar Battery anode system, accelerated tests in the presence or absence of some chloride content and cracks were carried out. The potential-decay, protection potential and corrosion current density of reinforcing steel in concrete specimen were measured to evaluate the effectiveness of the system. From the test results, the application of the system led to the satisfaction on NACE's criterion in all mixtures of concrete. Additionally it was found that protection potential and corrosion current density were satisfied due to the application of Surface Coating Anode and Solar Battery anode system.

• KIEE International Transactions on Power Engineering
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• v.2A no.3
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• pp.89-94
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• 2002

In this paper, a protection system using a Multi-Agent concept for power distribution networks is proposed. Every digital over current relay(OCR) is developed as an agent by adding its own intelligence, self-tuning and communication ability. The main advantage of the Multi-Agent concept is that a group of agents work together to achieve a global goal which is beyond the ability of each individual agent. In order to cope with frequent changes in the network operation condition and faults, an OCR agent, suggested in this paper, is able to detect a fault or a change in the network and find its optimal parameters for protection in an autonomous manner considering information of the whole network obtained by communication between other agents. Through this kind of coordination and information exchanges, not only a local but also a global protective scheme is completed. Simulations in a simple distribution network show the effectiveness of the suggested protection system.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.2
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• pp.119-122
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• 2020

With recent ESS (Energy Storage System) fire accident, the fault protection performance is becoming more important. However, there has never been any experiments with the protection performance on the faults in the ESS system level. In this study, the effect of AC ground fault and IGBT (Insulated Gate Bipolar mode Transistor) short-circuit failure on MW class ESS was performed experimentally for the first time in the world. First of all, the effect of the AC single line ground fault on battery was analyzed. Moreover, the transient voltage was investigated as a function of the battery capacity and the power level. Finally, the breaking capability and insulation performance of ESS were examined under PCS short-circuit fault condition. Through the tests, it was found that ESS protection system safely blocked the faulty current regardless of the faults, whereas the electronic parts such as IGBT and MC (Magnetic Contactor) were broken by the fault current. Also, the electrical breakdown in ESS resulted from the transient voltage during the protection process.