• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.11a
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• pp.43-43
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• 2011

현대인들은 생활환경에서 발생하는 각종 미세먼지 등의 입자상 오염물질 뿐만 아니라 각종 VOCs 등의 가스상 오염물질과 곰팡이, 박테리아, 바이러스 등 생물학적 오염물질까지 생활공간 내의 공기환경은 점점 악화 되고 있으며 공기 정화 등의 필요성이 증대 되고 있다. 이에 본 연구에서는 닥 펄프와 활성탄이 주성분인 Sheet를 Corrugation 장치를 통해 편파형(골판지)으로 제작하고, 다시 다층 구조로 적층된 골판지 sheet을 제작한 후 이를 두께 방향으로 일정 폭(20mm이하)으로 절단하여 필터부품의 소자로 이용하는 활성탄 필터의 제조 및 그 특성을 확인하고자 하였다. 닥펄프/펄프와 무기물의 혼합비, 해리시간 등의 변화를 주어 샘플을 만들었고, 강도, 평활성, 생산성 향상을 위해 첨가보조제 선정을 하였다. 이렇게 제조된 필터의 물리적 특성을 알아보고자 인장시험을 실시하였고, 주사전자현미경을 통하여 필터의 평활성과 표면을 관찰하였고 흡착성능 및 기능성을 VOCs 방출량, 탈취율, 항균도, 곰팡이 저항성 등의 실험을 통하여 알아보았다.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.5
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• pp.556-565
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• 2016

As a result of the enforced control of emission, many devices, including the diesel particulate filter, have been installed in diesel cars to reduce the emission of particulate matters. In this study, a car fire case has been investigated and analyzed. A car fire broke out after the vehicle traveled a distance of 1.4 km from a car service center. The car was provided with DPF cleaning when the DPF warning light came on. After being dismantled in the engine room, the car's engine and gearbox were investigated. The findings showed that the rear part of the DPF metal case was melted and punctured, while the honeycomb filter of the DPF was damaged. The car fire was caused by an overheated DPF associated with inaccurate maintenance practice. Therefore, the responsibility of the fire rested on the car service center that performed the DPF cleaning.

• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.66-71
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• 2011

This paper evaluates the performance and effectiveness of a layered coding scheme for an integrated mobile satellite systems, where the main target services are multimedia broadcasting and multicasting services (MBMS). In this integrated system, the satellite and complementary ground components (CGC) cooperate to provide high quality services. A layered coding scheme is a receiver driven adaptive schemes which adapts to the channel condition at the receiver. In this paper, we introduce a layered turbo coding scheme, and evaluates the performance in various scenarios, and discuss its effectiveness. The demonstrated results in the paper can be utilized in order to design an efficient integrated mobile satellite system, in the future.

• Journal of the korean Society of Automotive Engineers
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• v.9 no.5
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• pp.49-56
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• 1987

This paper is a study on the effect of the cutting speed on the tool wear in turning of the glass fiber reinforced plastics. The wear behavior of cutting tool is studied by means of turning, changing the cutting speed and feed in the wide range. Moreover, the theoretical model applicable to the cutting speed of wide range is analysed. The main results obtained are as follows: The relation between the tool wear and the cutting speed is divided into three range in case of the constant cutting distance. 1) At the low cutting speed, the tool wear is independent of the cutting speed, but dependent mainly on the contact length between tool and glass fiber(lst range). 2) At the high cutting speed, the tool wear is independent of the contact length, and dependent on the cutting speed only(2nd range). The tool wear increases in proportion to the cutting speed. 3) At the higher cutting speed than the speed in the 2nd range, the tool wear is independent both of the cutting speed and the contact length(3rd range). 4) In the 3rd range, tool flank wear is constant and is observed that only the wear of cutting edge increases.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.230-231
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• 2007

계통연계형 태양광 시스템을 구성하고 있는 전력변환장치인 PCS(power conditioning system)는 일반적으로 그 내부에 입력전력 평활용 Capacitor, DC-DC Converter, DC link Capacitor, DC-AC Inverter 및 L-C Filter 등으로 구성된다. 이러한 태양광 시스템의 구성은 주로 태양광 어레이와 PCS의 DC-DC Converter 및 DC-AC Inverter의 수와 연결 방법에 따라 여러 가지로 구성할 수가 있다. 본 논문에서 제안할 시스템의 구성은 하나의 태양광 어레이를 다수의 계통 연계형 태양광 PCS가 공유하는 형태인데, 이러한 시스템의 주요 장점은 첫째, 일사량에 따라 각각의 PCS가 모두 정격에서 운전하도록 하여 변환효율을 개선할 수 있다는 점과 둘째, 태양광 어레이의 용량 확장에 따른 PCS 장치의 용이한 확장성 그리고 셋째, 연결되어 있는 다수의 PCS 중 하나의 태양광 PCS가 고장으로 인하여 유지 및 보수가 필요할 때에도 그 외의 다른 정상적인 태양광 PCS는 지속적인 발전이 가능한 장점 등을 갖는다. 본 논문에서는 태양광 어레이의 출력을 공유하는 병렬운전용 태양광 PCS의 구성에 대하여 연구하고, 그 병렬운전기법을 제시하여 이에 대한 타당성을 시뮬레이션으로 검증하고자 한다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.2
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• pp.149-154
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• 2013

Short term load forecasting for electric power demand is essential for stable power system operation and efficient power market operation. High accuracy of the short term load forecasting can keep the power system more stable and save the power market operation cost. We propose an optimal coefficient selection method for exponential smoothing model in short term load forecasting on weekdays. In order to find the optimal coefficient of exponential smoothing model, load forecasting errors are minimized for actual electric load demand data of last three years. The proposed method are verified by case studies for last three years from 2009 to 2011. The results of case studies show that the average percentage errors of the proposed load forecasting method are improved comparing with errors of the previous methods.

• Journal of the Korean Society of Safety
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• v.24 no.4
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• pp.96-103
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• 2009

This study was fulfilled to investigate the forest fire risk of forest fuels based on the combustion characteristics of living leaves of coniferous trees and broadleaf trees naturally growing in Youngdong areas of Gangwon Province by using cone calorimeter and smoke density chamber. According to the result, Pinus densiflora and Pinus rigida among coniferous trees released a greater amount of heat release than other kinds. The total smoke release varied depending on the species, whereas Pinus koraiensis showed the largest amount of smoke release. With regard to maximum smoke density, it was much higher in coniferous trees than in broadleaf trees. With regard to smoke temperature, Pinus densiflora showed the lowest compared to other kinds up until 200s from the ignition, but all most trees uniformly maintained constant temperature of about $70^{\circ}C$ after 200s. The concentrations of CO and $CO_2$ release were drastically increased at about 150s and then gradually decreased thereafter. Pinus densiflora showed a bit higher CO release than broadleaf trees, but there was no distinct difference in $CO_2$ release among tress.

• Journal of the Korean Society of Safety
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• v.29 no.1
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• pp.21-24
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• 2014

In this study, we have investigated the maximum smoke density and the initial stage smoke density in order to see the characteristics of smoke release of the architectural surface materials and the architectural adhesives, using smoke density chamber. As a result of the study, polyurethane foam showed the highest smoke density index, 206.55 within 10 min. In the case of the other samples, reinforced styrofoam was followed as 39.90, general styrofoam 33.73, and glass fiber 5.40, respectively. In the intial stage of a fire, it is forecasted actually to give hardship at the clear visibility. In the case of architectural adhesives, the highest ranking was those for windows and doors 509.64, stone 275.63, wood 232.25, tile 18.65, and styrofoam 6.44 were followed, respectively. This result is an early research to show characteristics of smoke release through experiment. However, it is meaningful that this study can be used as a basic for further study on architectural fire hazard prediction.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.6
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• pp.828-832
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• 2013

In this paper, numerical analysis was performed about whether the flash fire of loaded shells breaks out in the virtual combat vehicle according to sorts of the kinetic energy ammunition as the preceding research for vulnerability analysis inside the combat system by an external threaty ammunition. In this simulation, Autodyn program was used and the Lee-Tarver ignition and growth model was used to determine the flash fire outbreak. In this study, the kinetic energy ammunition was set of type A and type B in two kinds and the loaded shells was set of COMPB, TNT, PBX9404 and ANB. As a result, TNT and PBX9404 have much higher flash fire probability than COMPB in high explosive, ANB has very low flash fire probability.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.1
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• pp.255-261
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• 2013

In this paper, we developed and tested a program for prediction flash fire in a combat system. Purposes of the program are flash fire prediction of combat system for analysis vulnerability and survivability, and visualization for fire-related information. To do this, we defined critical components of the combat system which has probabilities of flash fire occurrence, and proposed Flash Fire Probability Tree which is based on Fault Tree Analysis(FTA). The program visualizes positions of critical components in combat system, positions of penetrated components, selected Flash Fire Probability Tree, temperature profile, and tables for properties of matters.