• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.513-520
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• 2004

A steady-state/transient performance simulation model was newly developed for the propulsion system of the CRW (Canard Rotor Wing) type UAV (Unmanned Aerial Vehicle) during flight mode transition. The CRW type UAV has a new concept RPV (Remotely Piloted Vehicle) which can fly at two flight modes such as the take-off/landing and low speed forward flight mode using the rotary wing driven by engine bypass exhaust gas and the high speed forward flight mode using the stopped wing and main engine thrust. The propulsion system of the CRW type UAV consists of the main engine system and the duct system. The flight vehicle may generally select a proper type and specific engine with acceptable thrust level to meet the flight mission in the propulsion system design phase. In this study, a turbojet engine with one spool was selected by decision of the vehicle system designer, and the duct system is composed of main duct, rotor duct, master valve, rotor tip-jet nozzles, and variable area main nozzle. In order to establish the safe flight mode transition region of the propulsion system, steady-state and transient performance simulation should be needed. Using this simulation model, the optimal fuel flow schedules were obtained to keep the proper surge margin and the turbine inlet temperature limitation through steady-state and transient performance estimation. Furthermore, these analysis results will be used to the control optimization of the propulsion system, later. In the transient performance model, ICV (Inter-Component Volume) model was used. The performance analysis using the developed models was performed at various flight conditions and fuel flow schedules, and these results could set the safe flight mode transition region to satisfy the turbine inlet temperature overshoot limitation as well as the compressor surge margin. Because the engine performance simulation results without the duct system were well agreed with the engine manufacturer's data and the analysis results using a commercial program, it was confirmed that the validity of the proposed performance model was verified. However, the propulsion system performance model including the duct system will be compared with experimental measuring data, later.

• 한국작물학회지
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• 제51권1호
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• pp.66-72
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• 2006

Spikelet proteins expressed at the young microspore stage in rice were separated and analysed by two-dimensional polyacrylamide gel electrophoresis (2DE). The separated proteins were electro blotted onto a polyvinylidene difluoride (PVDF) membrane, and 50 proteins were analyzed by a gas-phase protein sequencer. The N-terminal amino acid sequences of 20 out of 50 proteins were determined. N-terminal regions of the remaining proteins could not be sequenced because of blocking. The internal amino acid sequences of proteins were determined by sequence analysis of peptides obtained by the Cleveland peptide mapping method. Results revealed the presence of the photosynthetic apparatus at rice young microspore stage. Major proteins identified in this study could be used as a marker for various studies on physiological stresses.

• Journal of the Korean Wood Science and Technology
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• 제48권5호
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• pp.591-607
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• 2020

This study was aimed to investigate the changes of chemical composition of the volatile organic compounds (VOCs) emitted from red pine needles in the process of needle abscission or senescence. The VOCs in intact, senescent, and litter red pine needle samples were analyzed by headspace-solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC/MS). And then, multivariate statistical interpretation of the processed data sets was conducted to investigate similarities and dissimilarities of the needle samples. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to investigate the dataset structure and discrimination between samples, respectively. From the data preview, the levels of major components of VOCs from needles were not significantly different between needle samples. By PCA investigation, the data reduction according to classification based on the chlorophyll a / chlorophyll b (Ca/Cb) ratio were found to be ideal for differentiating intact, senescent, and litter needles. The following OPLS-DA taking Ca/Cb ratio as y-variables showed that needle samples were well grouped on score plot and had the significant discriminant compounds, respectively. Several compounds had significantly correlated with Ca/Cb ratio in a bivariate correlation analysis. Notably, the litter needles had a higher content of oxidized compounds than the intact needles. In summary, we found that chemical compositions of VOCs between intact, senescent, and litter needles are different each other and several compounds reflect characteristic of needle.

• 한국농공학회논문집
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• 제61권3호
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• pp.89-99
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• 2019

The project to utilize kenaf as thermal power plant fuel has a positive effect on the unused energy utilization, greenhouse gas reduction, and farm income. However, it is analyzed that it is difficult to secure economical efficiency because the fuel cost of kenaf is higher than that of power by thermal power plant and Renewable Energy Certification (REC). The project of power generation using kenaf is meet the government's major policies, while government support is essential for securing economical efficiency. As a result of the sensitivity analysis on the ratio of the government subsidies, to secure economical efficiency, the power generation prices using kenaf through the direct financial support of the government indicate that 47% and 76% of kenaf fuel cost are supported by government in case of the Saemangeum reclamation and Gangneung-si, respectively. In the case of the government indirect policy support, if kenaf is included as a renewable energy source of Renewable Energy Portfolio Standard and REC is granted, the economic efficiency of Saemangeum reclamation and Gangneung-si is obtained when REC secured at 1.05 or more and 2.43 or more, respectively. The results of this study are meaningful in that the direct and indirect effects of the government on the development of the herbaceous energy crop, kenaf, were evaluated economically. These results are to suggest the need for demonstration study, but economics analyze and evaluate are necessary based on operational data through the demonstration phase in the future.

• International Journal of Computer Science & Network Security
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• 제22권3호
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• pp.37-44
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• 2022

Plug-in Hybrid electric vehicles (PHEV) show great potential to reduce gas emission, improve fuel efficiency and offer more driving range flexibility. Moreover, PHEV help to preserve the eco-system, climate changes and reduce the high demand for fossil fuels. To address this; some basic components and energy resources have been used, such as batteries and proton exchange membrane (PEM) fuel cells (FCs). However, the FC remains unsatisfactory in terms of power density and response. In light of the above, an electric storage system (ESS) seems to be a promising solution to resolve this issue, especially when it comes to the transient phase. In addition to the FC, a storage system made-up of an ultra-battery UB is proposed within this paper. The association of the FC and the UB lead to the so-called Fuel Cell Battery Electric Vehicle (FCBEV). The energy consumption model of a FCBEV has been built considering the power losses of the fuel cell, electric motor, the state of charge (SOC) of the battery, and brakes. To do so, the implementing a reinforcement-learning energy management strategy (EMS) has been carried out and the fuel cell efficiency has been optimized while minimizing the hydrogen fuel consummation per 100km. Within this paper the adopted approach over numerous driving cycles of the FCBEV has shown promising results.

• The Plant Pathology Journal
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• 제40권4호
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• pp.346-357
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• 2024

This study was carried out to screen the antifungal activity against Colletotrichum acutatum, Colletotrichum dematium, and Colletotrichum coccodes. Bacterial isolate GP-P8 from pepper soil was found to be effective against the tested pathogens with an average inhibition rate of 70.7% in in vitro dual culture assays. 16S rRNA gene sequencing analysis result showed that the effective bacterial isolate as Bacillus siamensis. Biochemical characterization of GP-P8 was also performed. According to the results, protease and cellulose, siderophore production, phosphate solubilization, starch hydrolysis, and indole-3-acetic acid production were shown by the GP-P8. Using specific primers, genes involved in the production of antibiotics, such as iturin, fengycin, difficidin, bacilysin, bacillibactin, surfactin, macrolactin, and bacillaene were also detected in B. siamensis GP-P8. Identification and analysis of volatile organic compounds through solid phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS) revealed that acetoin and 2,3-butanediol were produced by isolate GP-P8. In vivo tests showed that GP-P8 significantly reduced the anthracnose disease caused by C. acutatum, and enhanced the growth of pepper plant. Reverse transcription polymerase chain reaction analysis of pepper fruits revealed that GP-P8 treated pepper plants showed increased expression of immune genes such as CaPR1, CaPR4, CaNPR1, CaMAPK4, CaJA2, and CaERF53. These results strongly suggest that GP-P8 could be a promising biocontrol agent against pepper anthracnose disease and possibly a pepper plant growth-promoting agent.

• 분석과학
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• 제16권1호
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• pp.70-77
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• 2003

Hydroxyanilide계 살균제 fenhexamid의 작물 (오이, 딸기, 포도) 중 잔류량을 전자포획검출기가 장착된 기체크로마토그래피를 이용하여 최적 분석조건을 설정하고, 처리시기별 잔류량을 구하였다. 각 시료를 blender로 마쇄 후 acetone으로 1차 추출 한 후 dichloromethane으로 2차 추출하였으며, silica gel이 충전된 plastic 컬럼에서 acetone:hexane (5:95, 15:85, v/v) 혼합액으로 분리하였다. 표준 검량선의 회귀방정식은 0.05~0.20 ng에서 오이 Y=312.40X+10.26, 딸기 Y=313.33X+5.54, 포도 Y=253.27X-2.23 이었으며, 각각 $R^2=0.9996$, $R^2=0.9998$, $R^2=0.9994$의 직선성을 나타내었다. 0.10 mg/L 과 0.40 mg/L의 표준시료 처리시 평균 회수율은 오이, 딸기, 포도 각각 94.8%, 88.1%, 93.7% 이었으며, 순수표준품의 검출한계는 0.01 mg/L이었다. 각 작물체의 잔류량은 0.01~0.58 mg/L 범위이었다.

• 자원ㆍ환경경제연구
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• 제20권3호
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• pp.531-565
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• 2011

배출권 가격의 다변량 시계열자료를 이용하는 국내외 선행연구들은 모두 공통적으로 내생변수가 네 개 이내이며, 분석기간에서 가격자료에 왜곡이 발생한 2006년 4월~6월까지의 데이터를 포함하고 있다. 본 연구는 유럽 배출권 가격의 시계열자료를 분석하되, 내생변수를 다섯 개 이상으로 확장하였으며, 분석기간도 일간자료의 경우 비교적 신뢰성이 확보된 제2단계 기간의 자료(즉, 2008년 4월 21일~2010년 3월 31일)를 대상으로 하였고, 경제변수들을 내생변수로 포함하는 월간 자료를 추가로 분석하였다. 분석 방법은 그래프 이론과 구조적 벡터오차수정모형(SVECM)을 이용하였다. 본 연구 결과는 다음과 같이 요약된다. 첫째, 일간 자료에서 배출권 가격에 가장 큰 영향을 미치는 변수는 오일가격, 전력가격, 가스가격의 순으로 나타났다. 둘째, 일간 자료에서 배출권 가격이 전력가격에 전가된다는 기존의 이론이 최근 데이터에서도 입증되었다. 셋째, 일간 자료에서 그래프 분석 결과 브렌트유 가격이 인과흐름에서 중요한 중간 매체 역할을 수행하여 배출권 가격${\rightarrow}$브렌트유 가격${\rightarrow}$석탄/가스가격${\rightarrow}$전력가격으로 이어지는 인과흐름이 파악되었으며, 배출권거래소간에는 EEX 선물${\rightarrow}$BlueNext 선물${\rightarrow}$ECX 선물로 이어지는 인과흐름이 발견되었다. 마지막으로 월간 자료에서는 유로 산업생산지수와 영국 재무성증권90일물 금리, 유로 생산자물가지수 등 경제변수들이 배출권 가격에 큰 영향을 미치는 것으로 나타났다. 이것은 배출권 가격의 주요 결정요인으로 경제변수들을 포함시킬 수 있는 가능성을 보여주었다.

• 분석과학
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• 제11권5호
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• pp.374-385
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• 1998

주로 음식물의 섭취에 기인하는 phytoestrogen은 말초 신경 및 암 세포내에서 estrogen의 생성을 저해하거나, 농도를 감소시킴으로서 estrogen-dependent cancer의 잠재적인 항 증식 물질(antipromotional compound)로 알려지고 있으며, 이러한 이유로 estrogen 대사 과정에 대한 phytoestrogen의 관련성 여부가 연구의 대상이 되고 있다. 이에, 본 연구에서는 phytoestrogen과 estrogen 대사체들을 동시에 분석하기 위한 방법으로써 Serdolit AD-2 수지를 이용한 고체상 추출과 효소 가수분해, 액체-액체 추출 방법을 이용한 전처리 과정을 확립하였으며, 이를 MSTFA/TMCS 혼합액에 의해 trimethylsilyl(TMS) ether 형태로 유도체화 한 후 GC/MS의 SIM(selected ion monitoring) 방법으로 동시에 분석, 정량할 수 있는 조건을 설정하였다. 본 실험 방법의 정확도와 정밀도는 within-a day 및 day-to-day 시험으로 평가되었으며 회수율과 검출 한계는 각각 71.96~105.66%, 2~4 ng/mL 이었다. 이 방법을 이용하여 정상 성인 남녀의 뇨중에 존재하는 17종의 estrogen과 5종의 phytoestrogen 농도를 측정하였으며, 그 결과 남성과 여성의 뇨중 phytoestrogen과 estrogen의 농도 분포에 현저한 차이가 있음을 알 수 있었다.

• 한국세라믹학회지
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• 제41권5호
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• pp.410-416
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• 2004

초음파 여기 페라이트 플레이팅(ultrasound-enhanced ferrite plating)법으로 복잡한 형상을 가진 코디어라이트 허니컴에 마그네타이트(Fe$_3$O$_4$)를 코팅하고, 제조 공정 조건의 변화가 마그네타이트 코팅 막의 형성과 미세구조에 미치는 영향에 대해 고찰하였다. 또한, 수소 환원과정을 통해 제조된 산소부족형 마그네타이트 막을 이용하여 코팅막의 형성조건이 $CO_2$가스 분해 특성에 미치는 영향에 대해 검토하였다. pH 완충제($CH_3$COONH$_4$)의 몰농도가 증가함에 따라 제조된 허니컴에 코팅된 마그네타이트 막의 평균 입자 크기는 약 200∼250 nm로 증가하였다. 이들 코팅막을 30$0^{\circ}C$에서 2시간동안 수소 환원시켜 산소부족형 마그네타이트를 만든 후 $CO_2$ 가스 중에서 온도를 올리면서 반응기 내부의 압력변화를 측정한 결과, 약 315∼34$0^{\circ}C$를 시작으로 $CO_2$가 분해하면서 반응기 내부의 압력이 감소하였다. 350"$^{\circ}C$에서 수소 환원된 시편에서는 산소부족형 마그네타이트와 일부 $\alpha$-Fe 상이 나타났다. 허니컴에 코팅된 마그네타이트의 수소 환원 및 $CO_2$ 가스 분해 과정에서 생기는 중량 변화를 측정한 결과 수소 환원 과정에서 약 320∼34$0^{\circ}C$에서부터 급격한 중량감소가 일어났고, $CO_2$ 가스 분해 과정에서는 중량의 증가가 나타났다.