• 한국수소및신에너지학회논문집
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• 제34권6호
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• pp.608-614
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• 2023

The fast filling process of high-pressure hydrogen has an important impact on the filling efficiency and safety. In this paper, a specific study is carried out on the thermophysical phenomena during the fast filling process. Starting from the gas state equation of hydrogen, the change law of the hydrogen storage temperature is obtained, and then the temperature rise prediction is constructed. The model can clarify the relationship between the filling parameters and the temperature rise during the fast filling process, thereby revealing the flow and heat transfer laws of the fast charging process. To improve the theoretical research basis for the evaluation of vehicle-mounted hydrogen fast charging capacity, temperature prediction and optimization of hydrogenation methods.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.353-358
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• 2010

High pressure gas is a widely used storage mode for hydrogen fuel. A typical hydrogen tank that is charged with hydrogen gas can function as a hydrogen supply source in a large number of applications. The filling process of a high-pressure hydrogen tank should be reasonably short. However, when the fill time is short, the maximum temperature in the tank increases. Therefore the process should be designed in such a way to avoid high temperatures in the tank because of safety reasons. The paper simulates the fast filling process of hydrogen tanks using Computational Fluid Dynamics method. The local temperature distribution in the tank is obtained. Results obtained are compared with available experimental data. Further work is going on to improve the accuracy of the calculations.

• 한국작물학회지
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• 제36권1호
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• pp.34-40
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• 1991

본 시험은 대맥 등숙기간중 급속한 온도상승과 고온건조 및 과습 등 불량환경으로 맥체가 급격히 노화되어 충분히 등숙되지 않은 상태에서 성숙이 이루어지기 때문에 우리나라의 대맥은 품질이 불량할 뿐만 아니라 수량성도 외국에 비해 떨어지고 있는 실정이다. 따라서 등숙기의 엽신노화와 동화산물의 전류특성과의 관계를 구명하여 등숙향상을 위한 품종 육성 선발의 기초 자료로 이용코자 실시하였던바, 결과를 요약하면 다음과 같다. 1. 등숙일수 경과에 따른 엽신의 생엽수 및 노화속도는 품종에 따라 큰 차이가 있었다. 2. 입출전 및 동화물질의 전류속도는 엽신의 노화가 빠른 품종군이 늦은 품종군에 비해 빠른 것으로 나타났다. 3. 엽위 및 기관별로 $^{14}$ C 물질의 전류 양상을 본 결과, 등숙초기에는 노화가 빠른 품종군은 산위엽(지엽, 2엽)과 하위엽 ( 3, 4, 5엽)에 흡수된 $^{14}$ C의 량이 이삭으로 전류되는 비율이 비슷하였으나 등숙이 진전되면서 상위엽에 흡수된 $^{14}$ C은 전류가 급격히 이루어지나 하위엽은 반대의 경향이고, 노화가 늦은 품종군은 등숙초기에는 하위엽의 전류속도가 월등히 높고 하위엽은 낮으나 등숙이 진전되면서 반대의 양상으로 나타났다. 4. 경엽에 흡수된 $^{14}$ C이 종실로 정류되는 양상과 입충전속도가 엽신의 노화속도 조만 품종군별로 일치하는 경향이었다. 5. 광합성 속도는 등숙중기까지는 엽신노화가 빠른 품종이 높았으나 중기후는 낮았다. 6. 종실수량은 엽신의 노화속도가 빠른 품종군이 다소 높은 경향이었다.

• 대한원격탐사학회지
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• 제37권4호
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• pp.777-788
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• 2021

Since aerosol has a relatively short duration and significant spatial variation, satellite observations become more important for the spatially and temporally continuous quantification of aerosol. However, optical remote sensing has the disadvantage that it cannot detect AOD (Aerosol Optical Depth) for the regions covered by clouds or the regions with extremely high concentrations. Such missing values can increase the data uncertainty in the analyses of the Earth's environment. This paper presents a spatial gap-filling framework using a univariate statistical method such as DCT-PLS (Discrete Cosine Transform-based Penalized Least Square Regression) and FMM (Fast Matching Method) inpainting. We conducted a feasibility test for the hourly AOD product from AHI (Advanced Himawari Imager) between January 1 and December 31, 2019, and compared the accuracy statistics of the two spatial gap-filling methods. When the null-pixel area is not very large (null-pixel ratio < 0.6), the validation statistics of DCT-PLS and FMM techniques showed high accuracy of CC=0.988 (MAE=0.020) and CC=0.980 (MAE=0.028), respectively. Together with the AI-based gap-filling method using extra explanatory variables, the DCT-PLS and FMM techniques can be tested for the low-resolution images from the AMI (Advanced Meteorological Imager) of GK2A (Geostationary Korea Multi-purpose Satellite 2A), GEMS (Geostationary Environment Monitoring Spectrometer) and GOCI2 (Geostationary Ocean Color Imager) of GK2B (Geostationary Korea Multi-purpose Satellite 2B) and the high-resolution images from the CAS500 (Compact Advanced Satellite) series soon.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권5호
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• pp.1951-1972
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• 2018

Wi-Fi Access Point (AP) optimization approaches are used in indoor positioning systems for signal coverage enhancement, as well as positioning precision improvement. Although the huge power consumption of the AP optimization forms a serious problem due to the signal coverage requirement for large-scale indoor environment, the conventional approaches treat the problem of power consumption independent from the design of indoor positioning systems. This paper proposes a new Fast Water-filling algorithm Group Power Constraint (FWA-GPC) based Wi-Fi AP optimization approach for indoor positioning in which the power consumed by the AP optimization is significantly considered. This paper has three contributions. First, it is not restricted to conventional concept of one AP for one candidate AP location, but considered spare APs once the active APs break off. Second, it utilizes the concept of water-filling model from adaptive channel power allocation to calculate the number of APs for each candidate AP location by maximizing the location fingerprint discrimination. Third, it uses a fast version, namely Fast Water-filling algorithm, to search for the optimal solution efficiently. The experimental results conducted in two typical indoor Wi-Fi environments prove that the proposed FWA-GPC performs better than the conventional AP optimization approaches.

• 한국작물학회지
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• 제48권5호
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• pp.397-401
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• 2003

This experiment was conducted to know the characteristics of kernel growth as affected by various temperature regimes during grain filling using the varieties Hwaseongbyeo, Ilpumbyeo and Chucheongbyeo. The rice plants tested were grown in the natural condition at 1/5000a Wagner pots until flowering. After flowering, the rice plants were moved to controlled temperature conditions in a phytotron. The minimum/maximum daily temperature in the phytotron was controlled by 12/18, 15/21, 18/24, 21/27, and 24/$30^{\circ}C$, respectively. The grain weights were measured every three days after treatment. The mean daily kernel growth rate during active grain filling period showed different responses among varieties under various temperature regimes. The kernel growth rate of Chucheongbyeo was seriously reduced as temperature regimes were decreased. However, that of Ilpumbyeo was not influenced so critically. Ilpumbyeo showed some advantages in grain filling under low temperature regimes compared to Chucheongbyeo. The lag phase in grain filling of Chucheongbyeo was the longest among tested varieties, followed by Hwaseongbyeo under daily mean temperature regime of $15^{\circ}C$. Kernel weight of Ilpumbyeo increased fast in early grain filling phase under low temperature. This characteristic may be favorable for grain filling in temperate zone where the daily mean temperature is drastically dropped during grain filling period. Regression analysis with kernel growth rate and temperature showed the estimated critical low temperature for grain filling among varieties were $9^{\circ}C$, $12^{\circ}C$, $13^{\circ}C$ in Ilpumbyeo, Hwaseongbyeo and Chucheongbyeo, respectively. Under moderate temperature the duration of grain filling of Ilpumbyeo was longer than that of Chucheongbyeo. However, Under low temperature that of Ilpumbyeo was more favorable than Chucheongbyeo.

• 한국방사선학회논문지
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• 제10권2호
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• pp.117-124
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• 2016

본 연구에서는 디지털 의료용 X선을 이용하여 소듐냉각고속로 금속연료봉 내부의 소듐 충전상태를 평가하고자 하였다. 의료용 X선은 디지털방사선(digital radiography, DR)시스템을 사용하였다. 최상의 공간분해능을 도출하기 위해 X선관의 초점크기와 디지털영상후처리 방법을 변화시켰다. 이때 텅스텐을 이용한 에지방법의 변조전달함수(modulation transfer function, MTF)를 사용하여 선예도(0.5 MTF)와 해상도(0.1 MTF) 를 평가하였다. 그 결과 소초점에서 영상후처리의 대조도를 강화시킨 조건에서 3.871 lp/mm (0.1 MTF)와 3.290 lp/mm (0.5 MTF)의 공간분해능을 얻었다. 결론적으로 이러한 결과는 디지털 의료용 X선을 이용하여 소듐냉각고속로 금속연료봉 내부의 소듐 충전상태를 관찰할 수 있었다.

• 한국육종학회지
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• 제40권3호
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• pp.291-294
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• 2008

밀양 23호와 기호벼의 재조합 자식 164계통에 대하여 Rapid Visco Analyzer(RVA)방법으로 분석한 아밀로그램특성을 출수 후 15일째의 이삭무게를 출수 후 40일째의 이삭무게 비율로 계산한 초기급속등숙속도(rapidity of grain filling:RGF)품종군별로 호화온도, 최고점도, 최저점도, 최종점도, 강하점도, 응집점도 및 취반점도를 해석하였고 품종군별 아밀로그램특성간 상관관계를 분석하였다. 사용한 164 M/G RILs를 RGF에 따라서 완만등숙형(40%이하의 RGF), 준완만등숙형(41- 60% RGF), 준급속등숙형(61-80%RGF), 그리고 급속등숙형(81%이상 RGF)으로 구분되었으며 최고점도, 최저점도 및 취반점도는 RGF품종군별 일정한 경향을 보였다. 초기급속등숙속도를 기준으로 분류한 모든 품종군에서 강하점도와 취반점도는 고도의 부의 상관을 보였고 응집점도와 취반점도는 고도의 정의 상관을 보였다.

• 한국재료학회지
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• 제9권6호
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• pp.583-588
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• 1999

The characteristics of copper thin films and pattern filling capability were investigated by ECD. Prior to deposition of copper film, seed-Cu/Ta(TaN)/$SIO_2$(BPSG)/Si structure was manufactured. Copper deposition was performed with various current waveforms(DC/PC, 1~10,000Hz) and current densities(10~60 mA/$\textrm{cm}^2$) after pretreatment (Oxident removal, wetting) of seed-layer. Conformal pattern filling was performed using PC method with fast deposition rate of 6,000~8,000$\AA$/min. Heat-treated($450^{\circ}C$, 30min) copper films showed good resistivities of 1.8~2.1$\mu$$\Omega$.cm. According to the XRD analysis, (111)-preferred orientation of copper film was found in ECD-Cu/seed-Cu/Ta/$Sio_2$/Si structure. Also, we have successfully achieved to fill via holes with 0.35$\mu\textrm{m}$ width and 4:1 aspect ratio.

• 한국염색가공학회지
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• 제12권1호
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• pp.1-11
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• 2000

This paper surveys the fabric weavability and machine efficiency in the various weaving looms such as Projectile, Rapiers, and Air-jet. Used projectile loom was Sulzer-PU, and FAST-R, THEMA-11E, and Picanol-GTX were used for Rapier looms, as the Air-Jet looms, Picanol PAT and OMNI types were used. Using these looms, 5 harness worsted satin fabrics were woven for surveying the fabric weavability and machine efficiency. Warp yam count of fabric is 1/40Nm, Sirofil, and filling is 1/30 Nm, worsted. End breaks of warp and filling directions for the various types of looms are measured and discussed with the mechanism of each loom. Warp and filling yam tensions are also measured and analysed with open width of shedding motion of each weaving machine. And various warp yam tensions with open width of shedding are measured and analysed according to the warp yam in various heald frame. These results fire also discussed with temples such as bar and ring. Warp yam tensions at the various positions on the fabric with various looms are measured and discussed with fabric mechanical properties such as tensile, bending, shear and surface.