• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.527-530
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• 2006

Because price of fossil fuel rises, necessity about alternative energy was risen. Studied co-combustion of RPF to coal fluid bed boiler by necessity of these althernative energy. Purpose of this study to coal fluid bed bioler RPF when did co-combustion, change operating condition and characteristic of air pollutant examine according to change of fuel characteristic, operating condition examined about combustion chamber temperature, oxygen content etc. and air pollutant examined about material that is included to allowable exhaust standard and dioxin. Co-combustion condition was 5%. It was no peculiar under test result operating condition. Concentration of Co and HCl rose according as do RPF co-combustion and the other pollutants had hardly changed. Dioxin is low concentration level more than $0.1ng-TEQ/Sm^3$. There was no pollutant that exceed akllowable exhaust standard for boiler but $SO_x,\;NO_x$ were exceeded about allowable exhaust standard for incinerating facility.

• 한국재료학회지
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• 제33권6호
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• pp.229-235
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• 2023

An all-perovskite oxide heterostructure composed of SrSnO₃/Nb-doped SrTiO₃ was fabricated using the pulsed laser deposition method. In-plane and out-of-plane structural characterization of the fabricated films were analyzed by x-ray diffraction with θ-2θ scans and φ scans. X-ray photoelectron spectroscopy measurement was performed to check the film's composition. The electrical transport characteristic of the heterostructure was determined by applying a pulsed dc bias across the interface. Unusual transport properties of the interface between the SrSnO₃ and Nb-doped SrTiO₃ were investigated at temperatures from 100 to 300 K. A diodelike rectifying behavior was observed in the temperature-dependent current-voltage (IV) measurements. The forward current showed the typical IV characteristics of p-n junctions or Schottky diodes, and were perfectly fitted using the thermionic emission model. Two regions with different transport mechanism were detected, and the boundary curve was expressed by ln I = -1.28V - 13. Under reverse bias, however, the temperature- dependent IV curves revealed an unusual increase in the reverse-bias current with decreasing temperature, indicating tunneling effects at the interface. The Poole-Frenkel emission was used to explain this electrical transport mechanism under the reverse voltages.

• KIEAE Journal
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• 제13권2호
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• pp.157-162
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• 2013

To deal with the water pollution arising from the construction site, this study raises the issues of management and laws and it suggest the efficient way to reduce water pollution by through the case studies. In order to study, seven cases were selected from "Construction Environmental Management Best Practice Competition" co - sponsored by Construction Association of Korea and Construction Environment Association. As a study result, there are problems that depending on the characteristic of the construction site environment simple alone settling facilities can not handle muddy and dirty water generated by the construction site. However, when the construction site applied improved water pollution control facilities with reflecting the characteristic of muddy and dirty water. The problem can be solved moreover it can achieve exceeded emission standard. Therefore new regulations and management with water pollution control facilities considering characteristic of environment is needed to cope with water pollution arising from the construction site.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2345-2348
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• 1999

Existing $\psi$-AEA-t (phase-AEA-time) characteristic in polymer materials for power cable is good in general deterioration characteristic according to time variation, but it is difficult to clearly distinguish from deterioration state and diagnosis of deterioration is not enough to some extent. This paper is interpreted AE discharge statistics quantities measuring phase-amplitude variation of acoustic emission characteristic obtained from treeing breakdown experiment. Besides it can know useful discharge statistics quantities (AE average inception phase/amplitude, AE average maximum phase/amplitude) about so many for diagnosis of treeing deterioration.

• 한국통신학회논문지
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• 제19권3호
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• pp.523-532
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• 1994

GTEM cell의 특성 임피던스에 대한 정확한 값을 알면 그것을 설계하는데 매우 유용하다. 본 논문은 전자파 감응성 및 복사 측정 모두에 사용할 수 있는 GTEM cell을 그의 개방각을 고려한 특성 임피던스에 대해 논한다. 해석을 위해 over-RGM에 대해 기술하고, 이 수치해석법을 구좌표계에 실시한다. 몇가지 결과를 다른 논문의 것들과 비교하고, 본 해석의 정당성을 입증한다. GTEM cell 단면 상의 기하학적 구조변화에 따른 특성 임피던스 값들을 구하고 개방각이 특성 임피던스에 미치는 영향을 보인다. 마지막으로 여러 개방각에 대한 단면 상의 전계 균일도를 구한다.

• 한국기계가공학회지
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• 제18권1호
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• pp.65-71
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• 2019

The development of adsorbed natural gas (ANG) has emerged as one of potential solutions. It is desirable to reduce the weight of vessel by applying light-weighed a composite carbon fiber in order to response to a egulation of $CO_2$ emission. Through understanding of a composite carbon fiber, and material characteristic of a composite carbon fiber is required in order for better application of a reduction of weight and an analysis of material characteristic. Herein, this study suggest the composite carbon fiber vessel applied to the characteristic of carbon fiber, and it decides the preliminary shape based on the test of material characteristic for ANG vessel applied to a composite carbon fiber, and its basic shape calculate through on the netting theory. Moreover, the detail shape design is analyzed by a finite element analysis, and in the stage of detail sahp design and analysis of stress was performed on the typical shape using a finite element analysis, and the result of preliminary design was verified.

• 비파괴검사학회지
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• 제29권5호
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• pp.466-472
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• 2009

고온, 고압의 원자력 배관 누설 판별을 위해 음향방출기법(AE)을 이용한 누설감지 시스템인 ALMS 기법이 적용되고 있다. 이 시스템은 단지 AE 센서로 전해진 신호의 RMS값을 이용하여 누설의 유무만을 판단할 뿐, 누설 발생시 누설부의 크기나 형태를 평가하는 것에는 어려움이 있었다. 따라서 본 논문에서는 이러한 문제를 해결하기 위하여 AE센서와 가속도센서를 동시에 이용한 이중 센서 시스템을 제안하였다. 빠른 학습 속도와 정확성을 위해 Levenberg-Marquardt 학습 알고리즘을 이용한 인공신경회로망을 적용시키고, 이를 통해 신뢰성 있는 분석 결과를 얻을 수 있다. 배관내 압력과 누설부의 크기와 모양에 따른 실험신호들을 학습시키고 그 판별 정확성을 확인하였다. 추가적으로 배관 두께에 따라 발생하는 파(wave)의 종류와 특성이 달라지는 것을 이론과 실험을 통하여 알아보았다.

• 한국분무공학회지
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• 제17권3호
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• pp.113-120
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• 2012

It is being more serious problems that the pollutant and the greenhouse gas emitted from the internal combustion engines due to the increasing demand of automobiles. To counteract this, as one of the ways has been studied, GDI type engine, which is directly injected into the combustion chamber and burns by a spark ignition that chose the merits of both gasoline engine and diesel engine, was appeared. The combustion phenomena in this GDI engine is known to contribute to combustion stability, fuel consumption reduction and reductions of harmful substances of exhaust gas emission, when the fuel spray of atomization being favorable and the mixture formation being promoted. Accordingly, this study analyzed the affection of ambient temperature and fuel injection pressure to the fuel by investigate the visualization of combustion, combustion pressure and the characteristic of emission, by applying GDI system on the constant combustion chamber. As a result, as the fuel injection pressure increases, the fuel distribution in the combustion chamber becomes uniform due to the increase of penetration and atomization. And when ambient temperatures in the combustion chamber become increase, the fuel evaporation rate being high but the penetration was reduced due to the reduction of volume flux, and confirmed that the optimized fuel injection strategy is highly needed.

• 한국안전학회지
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• 제30권1호
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• pp.111-118
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• 2015

In this study, we carried out the emissions analysis of CO and $non-CO_2$ for the age-classes of various pine trees(Pinus koraiensis, Pinus densiflora, Pinus rigida Mill., Pinus thunbergii Parl.) to estimate of emission factors of the crown layer and surface layer in the forest fire. We used the thermal characteristic analyzer cone heater and NDIR analyzer in order to measure amount of emission. As a result, the major emissions of Pinus koraiensis were $CO_2$ and $CH_4$ and that of Pinus thunbergii Parl. was only CO. The major emissions of the most of pine trees were NO and $N_2O$. The $CO_2$ emission of Pinus thunbergii Parl. was the highest about as $7.26{\times}10^{-2}{\sim}1.63{\times}10^{-1}g$ and next came Pinus densiflora, Pinus koraiensis, Pinus rigida Mill.. And the CO emission of Pinus thunbergii Parl. was about $5.14{\times}10^{-3}{\sim}6.58{\times}10^{-3}g$ and followed by Pinus densiflora, Pinus koraiensis, Pinus rigida Mill.. The emissions of $CH_4$, NO, and $N_2O$ showed small differences between species and the emission of $CH_4$ was $8.37{\times}10^{-5}{\sim}2.55{\times}10^{-4}g$, and NO was $6.65{\times}10^{-5}{\sim}2.0{\times}10^{-4}g$ and $N_2O$ was $1.42{\times}10^{-4}{\sim}2.09{\times}10^{-3}g$ in all species. Particularly, the emission of Pinus thunbergii Parl. was the highest in all pine trees except $CH_4$.

• 대한전자공학회논문지TE
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• 제39권1호
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• pp.9-15
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• 2002

본 논문은 청색 유기 EL 소자를 진공증착법으로 제작하여 그 특성을 분석하였다. 발광층 물질(A1q/sub 3/)에 게스트물질(Type I-TPB와 Type II-DPA)의 도핑농도(0.5∼2 wt%)를 변화시켜 청색발광소자를 제작하여 전기적, 광학적 특성을 조사하였다. Alq3에 도펀트의 농도를 증가함에 따라 청색에 해당하는 색좌표 점으로 이동하였다. Type I이 Type II의 경우보다 동작개시전압 및 구동전압이 낮게 나타났으며 휘도에서는 Type II가 밝게 나타났다. Alq/sub 3/에 DPA(2wt%)를 도펀트로 사용한 소자의 경우 인가전압 15V에서 휘도는 1282cd/m/sup 2/, 최대발광 파장은 476nm, 색좌표는(0.1273, 0.0672)으로 우수한 특성을 나타내었다.