• Journal of the Regional Association of Architectural Institute of Korea
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• v.20 no.6
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• pp.1-8
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• 2018

In generally, the estimation work regarding building mechanical service system in comparison with other architectural estimations is time-consuming, and the process is continuously getting more difficult because of the increased usage of the attached piping materials such as fittings and supports in addition to their complicated construction processes. In order to improve this problem, the Korean authority provides a simple method to estimate the attached material rate regarding the main piping material, which is the most time-consuming work in the architectural mechanical estimation. However, to be an applicable method on construction site, a proper conversion rate of the attached piping material is still required for the proposed method regarding building usage and working types. Therefore, the purpose of this research is the suggestion of the material and labor cost rate of the attached piping materials such as the fittings and supports by work types and fitting methods of indoor fire, sprinkler, and extinguishing gas piping work of mechanical fire protection facilities in office buildings that have been designed after 2010.

• Journal of Radiation Protection and Research
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• v.38 no.4
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• pp.179-184
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• 2013

The biological effects of radiation are dependent on the dose rate and dose of radiation. In this study, effects of dose and dose rate using whole body radiation on plasma cytokines and blood count from male BALB/c mice were evaluated. We examined the blood and cytokine changes in mice exposed to a low (3.49m Gy $h^{-1}$) and high (2.6 Gy $min^{-1}$) dose rate of radiation at a total dose of 0.5 and 2 Gy, respectively. Blood from mice exposed to radiation were evaluated using cytokine assays and complete blood count. Peripheral lymphocytes and neutrophils decreased in a dose dependent manner following high dose rate radiation. The peripheral lymphocytes population remained unchanged following low dose rate radiation; however, the neutrophils population increased after radiation. The sera from these mice exhibited elevated levels of flt3 ligand and granulocyte-colony-stimulating factor (G-CSF), after high/low dose rate radiation. These results suggest that low-dose-rate radiation does not induce blood damage, which was unlike high-dose-rate radiation treatment; low-dose-rate radiation exposure activated the hematopoiesis through the increase of flt3 ligand and G-CSF.

• KDI Journal of Economic Policy
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• v.39 no.4
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• pp.69-94
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• 2017

This paper re-examines the impacts an institutional arrangement may have on labour market outcomes such as the employment and unemployment rates. Based on the results from a generalized econometric model, the generosity of unemployment insurance benefits, organized labour and active labour market policy have effects on a labour market in line with previous findings. However, taxes on labour and the degree of employment protection are found to affect neither the employment rate nor the unemployment rate. Thus, some findings in this paper validate earlier findings, whereas others do not.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.301-303
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• 2004

In distribution system about 5% of total outage is due to the lightning stroke. In order to reduce the rate of outage occurrence, distribution lightning protection equipments such as a secondary arrester, arching horn and various ground electrodes are developed and installed in the inside and outside of the county. Therefore it is needed to construct the test facilities to analyze the effect of these equipments. In this paper we describe the main content of the test facilities of lightning protection equipments. We have completed the field test of distribution lightning protection equipments for example lightning arrester, secondary arrester and arching horn etc.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.1822-1831
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• 2014

Micro-grid is connected to the main power grid through a static switch. One of the critical issues in micro-grids is protection which must disconnect the micro-grid from the network in short-circuit contingencies. Protective methods of micro-grid mainly follow the model of distribution system protection. This protection scheme suffers from improper operation due to the presence of single-phase loads, imbalance of three-phase loads and occurrence of power swings in micro-grid. In this paper, a new method which prevents from improper performance of static micro-grid protection is proposed. This method works based on artificial neural network (ANN) and able to differentiate short circuit from power swings by measuring impedance and the rate of impedance variations in PCC bus. This new technique provides a protective system with higher reliability.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.99-101
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• 2002

This paper is to introduce the R&D project called "System Protection with emphasis on Power System Stability". The principal objective of this project is protection aids to system stability. The objects of this project arc as follows. First, drawbacks of classical under frequency load shedding and implementation issues of the rate-of-change of frequency will be described. Secondly, the project discusses the possibilities of voltage instability in power system and how this risk will affect protective relays in real system. Lastly, special protection system is designed to preserve system stability for KEPCO.

• Journal of Auto-vehicle Safety Association
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• v.9 no.4
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• pp.14-19
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• 2017

The mortality rate of car-pedestrian accidents is quite high compared to the frequency of accident. Recently, governments and insurance companies tend to establish and implement new safety standards for pedestrian protection such as EURO-NCAP and K-NCAP. The performance for the pedestrian protection has been gradually improved, but it is still insufficient. Therefore, various studies for the pedestrian protection are being carried out. The car-pedestrian accident is simulated in order to study to the upper legform test of the EURO-NCAP protocol. A pedestrian dummy model is employed and the results are discussed.

• International journal of advanced smart convergence
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• v.2 no.1
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• pp.27-29
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• 2013

This paper discusses comparative analysis of the effects of surge protection devices (SPD) upon the power line communication channels. The quality of the data transmission channel is measured based on the data rate for the various channel parameters which include channel length and application method of the lightning protection device. The performance measurements are also carried out for various lengths of the communication channel. Experiment results show that specific combination of SPDs applied in the network causes severe degradation of the channel quality which is associated with the combination of grade levels and channel lengths.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2012.04a
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• pp.129-132
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• 2012

본 연구는 건축물의 초기화재성상의 주요인자인 화재성장율 예측을 위하여, 일본 송산(松山)모델을 사용하여 예측값을 도출한 결과, 화재성장율은 $0.0144t^2$로 나타났다. 또한 이를 실규모실험(ISO-9705)와 FDS 해석값과 비교한 결과, $Q_{peak}$을 고려한다면 신뢰할 수 있다고 판단 할 수 있지만 약100초 이상의 결과에서는 환기인자 등에 관한 변수에 대한 고려가 필요할 것으로 판단된다.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.800-802
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• 1997

After flashover occurs on the overhead distribution line by lighting strokes(direct or induced), the power frequency arc current continues. If lightning flashover occurs on the overhead lines using covered conductors, the power frequency art current with fixed path overheats the conductor, and arc fusion fault can be occurred. There are two categories protecting or reducing methods of arc fusion faults caused by lightning stokes. - Reducing lightning flashover rate : G/W, LA, etc. - Protection by AFPD(Arc Fusion Protection Device) : power follow current interruption. This paper presents lightning surge phenomena on overhead distribution lines and protecting performance of arc fusion Protection devices to the lightning strokes nearby overhead line.