• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.301-303
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• 2005

IEC 61850 is an international standard for substation communications. It introduces function that provide a substation with autonomous behavior of IEDs. The paper presents the model which is for change and modification of the IED setting values with analyzing IEC 61850.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.2
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• pp.135-143
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• 1991

The setting problem of protective devices in power distribution systems is a combinatorial search problem involving a lot of trial & errors to search for a proper solution which has a great impact for the system reliability. This paper discusses the nature of the problem and proposes a scheme to prune the decision tree achieving the efficient search for a setting solution by applying heuristic rules which utilize pattern informations of backup and primary devices. Its effectiveness is demonstrated through many tests on real systems.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.37-44
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• 2004

This paper represents a new approach for the protective relay of power transmission lines using a Artificial Neural Network(ANN). A different fault m transmission lines need to be detected classified and located accurately and cleared as fast as possible. However, The protection range of the distance relay is always designed on the basis of fixed settings, and unfortunately these approach do not have the ability to adapt dynamically to the system operating condition. ANN is suitable for the adaptive relaying and the detection of complex faults. The backpropagation algerian based multi-layer protection is utilized for the teaming process. It allows to make control to various protection functions. As expected, the simulation result demonstrate that this approach is useful and satisfactory.

• Journal of Radiation Industry
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• v.17 no.1
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• pp.61-67
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• 2023

A Study on the Introduction of Dose Constraints for Occupational Exposures: Focusing on Experts' Opinions by Field of Radiation Industry. The International Commission on Radiological Protection suggests Justification, Optimization, and Dose Limits as the three principles of radiological protection, among which, as a means of protection optimization, ICRP 103 recommends to set dose constraints. In this study, opinions are collected from experts in each category of radiation industries for stakeholder participation to qualify dose constraints. A guidance and questionnaire for analyzing the dose constraints have been developed for their collection, and opinions were collected from radiation protection experts in selected categories. 20 out of 22 experts, consisted with 91%, have assessed the dose constraints setting is necessary, and 2 experts, consisted with 9%, assessed it is unnecessary. The average of dose constraint presented by experts for RI production institutions is to be the highest level of 15.3 mSv, and light-water reactors (14.6 mSv), non-destructive inspection (14.4 mSv), heavy-water reactor and medical institutes (13.9mSv) is to be above the overall average dose constraint. In case of public institutions, the average dose constraint is to be 8.6mSv, and research institutions (8.8mSv), educational institutions (9.6 mSv), waste disposal sites (9.7 mSv), and general industries (10.6 mSv) are resulted to below the overall average dose constraint. As for the means of setting dose constraints, 8 experts out of 22 suggested setting dose constraints for each specific industry or task. And, 5 experts especially suggest setting dose constraints for the specific groups with relatively high exposure, such as workers with above the record levels. As a countermeasure for workers who exceed the dose constraints, 15 experts out of 22 expressed that the cause analyses for them and preparation for a plan of reducing them are necessary.

• Journal of the Korean Ceramic Society
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• v.56 no.1
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• pp.56-64
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• 2019

Calcium phosphate bone cement was prepared to contain antibiotics for release after setting using granulated ${\beta}$-tricalcium phosphate (${\beta}$-TCP) and hydroxyapatite (HA). Gentamicin sulfate (GS) solution was infiltrated within the interconnected pores of the granule to avoid affecting the setting reaction and for protection of GS during the setting. Consequently, the setting time and the temperature increase were not affected, regardless of the loading of GS. The release of the GS from the cement was estimated by measuring the concentration at regular intervals from the cement dipped solution. The ${\beta}$-TCP granule loaded with GS exhibited the saturation of accumulative concentration at 16 h. In contrast, the HA granule with GS exhibited steady increase in accumulative concentration of over $10{\mu}g/ml$ at 144 h. Thus, the granulated cement could release the GS greater than the minimum inhibitory concentration of staphylococcus during the prescription peroid of the oral antibiotics.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.229-232
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• 1998

Recently it has become general to use the inhibitor with a view to protecting corrosion of rebars in concrete. As the inhibitors used in construction works are almost made in America or Japan, we immediately need to begin home production of inhibitors. In this paper, to estimate the domestic anodic inhibitor of nitrite in comparison with foreign made inhibitor we made some fundamental experiments of setting time, slump and compressive strength. Besides, we analysed the effect of corrosion protection of inhibitor on the ground of corrosion current, resistance to chloride penetration and diffusion of chloride ingress in concrete.

• Fire Science and Engineering
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• v.2 no.1
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• pp.21-28
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• 1988

This paper deals with the optimal use of the ELB (Electric Leakage circuit Breaks) for the protection of low voltage distribution system. Since the ELB is recently used together for grounding fault while only the ground resistance was used in the past, the analysis of ELB characteristics is indispensible. By the quantitative analysis and the setting of limit the ground resistance and the ELB is derived and then the optimal use of the ELB is expected to contribute to the system protection.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.1
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• pp.35-40
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• 2012

An AC generator is an important component in producing an electric power and so it requires highly reliable protection relays to minimize the possibility of demage occurring under fault conditions. It is a need for research of digital generator protection system(DGPS) for the next-generation ECMS and an efficient operation of protection control system in power station. However, most of protection and control system used in power plants have been still imported as turn-key and operated in domestic. This may cause the lack of the correct understanding on the protection systems and methods, and thus have difficulties in optimal operation. In this paper, presented ratio differential relaying(RDR) is main protective element in generator protection IED. The fault detection technique, operation zone and setting value of the RDR were studied and, compared with two of the fault detection algorithm. For evaluation performance of the RDR, the data obtained from ATPDraw5.7p4 modeling was used. The proposed methods are shown to be able to rapidly identify internal fault and did not operate a miss-operation for all the external fault.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.358-362
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• 1991

This paper describes enhancements made on PROSET, an, expert system which can perform setting and coordination of protective relays used in the ultra-high voltage transmission systems. Enhancements include the friendly and convenient environment for rulebase management and system manipulation, expanded setting capability, and faster processing speed which have been achieved through adoption of the new rule representation, rule order independent IE, rulebase editor, local database generator, Interface to PSS/E fault program, RB expansion etc.

• Journal of Electrical Engineering and Technology
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• v.8 no.1
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• pp.64-69
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• 2013

For power system protection, the distance relay settings are important. Apparent factor is a necessary parameter in distance relay settings. Apparent factors have to be calculated when setting the distance relays and doing the resetting in case of configuration change in power system. The problem is that the current method to calculate apparent factor requires tools and plenty of time to do fault analysis and this method is complex especially in case of configuration change. Therefore this paper proposes a fast algorithm to calculate apparent factor without the fault analysis. Test results prove that this algorithm is simple and accurate by simulation.