• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.370-377
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• 2000

The red ginseng is very popular as a health food. It has been manufactured with raw ginseng by the conventional method. But, the yield of the heaven grade ginseng (the best quality red ginseng) among the whole products is around 5-7％, Therefore, the yield should be improved in order to increase economic returns. In this study, a new model of drying system was developed to improve the yield of heaven grade ginseng from 7% to 15% or more. For this system, temperature and relative humidity were controlled by the feedback control system, and a solenoid valve for steam supply and other variables were controlled by the PC. The special features of this system developed are an image processing system for monitoring the red ginseng during the drying process in the drying chamber, and a cylindrical porous tray for holding ginseng that is rotating with the speed of 0-10rpm in the drying chamber and makes uniform drying of red ginseng possible.

• 대한기계학회논문집B
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• 제25권8호
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• pp.1140-1147
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• 2001

Experimental schemes that enable characterization of phase-change phenomena in the microscale regime are essential for understanding the phase-change kinetics. Particularly, monitoring rapid vaporization on a submicron length scale is an important yet challenging task in a variety of laser-processing application, including steam laser cleaning and liquid-assisted material ablation. This paper introduces a novel technique based on Michelson interferometry for probing the liquid-vaporization process on a solid surface heated by a KrF excimer laser pulse(λ=248nm, FWHM=24ns) in water. The effective thickness of a microbubble layer has been measured with nanosecond time resolution. The maximum bubble size and growth rate are estimated to be of the order of 0.1㎛ and 1m/s, respectively. The results show that the acoustic enhancement in the laser induced vaporization process is caused by bubble expansion in the initial growth stage, not by bubble collapse. This work demonstrates that the interference method is effective for detecting bubble nucleation and microscale vaporization kinetics.

• 한국재료학회지
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• 제10권2호
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• pp.166-170
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• 2000

농축 우라늄 $UF_6$로 건식법 중의 하나인 DCP법으로 핵연료 $UO_{2+x}$ 분말을 제조하였다. Rotary kiln 내로 수증기를 주입할 때 일어나는 온도 변화에 따른 $UO_{2+x}$ 분말 특성을 우라늄 분석기, 수분 측정기, SEM 등으로 측정하였다. 그 결과 불소의 함유량은 8ppm을 나타냈고, 수분 함량의 경우 최적화되었음을 알 수 있었다.

• 한국식품영양학회지
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• 제14권5호
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• pp.423-429
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• 2001

Process optimization of milling and puffing condition of the typical varieties of wheat such as HRS, ASW, and SW were studied. Distibution of optimal milling size of 8 mesh-on was more than 90% after milling of three wheats. That of HRS was the highest, 78%, and that of SW and ASW were pretty high, above 75%. Moisture content of three wheats was between 10∼12%, and protein content which are important for texture profile and puffing was 12.68%, 13.59%, and 11.82% for SW, HRS, and ASW, respectively. Puffing was optimal of 7 kg/$\textrm{cm}^2$ heating pressure for SW, and 5 kg/$\textrm{cm}^2$ lot HRS and ASW when the puffing process was pursued at 14.5 ∼15.0 kg/$\textrm{cm}^2$ steam pressure. Moisture content decreased from 11∼l3% to 5.6∼6.0% after puffing. Bulk density of SW, HRS, and ASW was 0.0441, 0.0523, and 0.0460, respectively. Size distribution of HRS was 82.4% after Puffing. Press strength of HRS was high, 51.0%, and texture of HRS was crispy.

• 한국표면공학회지
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• 제37권4호
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• pp.226-233
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• 2004

The residual stresses on the surfaces of low carbon 12Cr steels used as a nuclear steam turbine blade material have been studied by controlling the flame hardening surface treatments. The temperature cycles on the surfaces of 12Cr steel were controlled precisely as a function of both the surface temperature and cooling rate. The final residual stress state generated by flame hardening was dominated by two opposite competitive contributions; one is tensile stress due to phase transformation and the other is compressive stress due to thermal contraction on cooling. The optimum processing temperatures required for the desirable residual stress and hardness were in the range of $850^{\circ}C$ to $960^{\circ}C$ on the basis of the specification of GE power engineering. It was also observed that the high residual tensile stress generated by flame hardening induced the cracks on the surfaces, especially across the prior austenite grain boundaries, and the material failure virtually, which might limit practical use of the surface engineered parts by flame hardening.

• 한국항해학회지
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• 제14권4호
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• pp.17-30
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• 1990

Since L.A. Zadeh introduced the theory of fuzzy sets in 1965, E.H. Mamdani applied the theory to the steam engine control in 1974. Since then, scientists have shown a great deal of interests in its application to practical problems and the possibility of the application of the theory a more complicate system has been increasing greatly. In the fuzzy control, the qualitative knowledge and intuition that the operators of a system has acquired through their experience can be logically described by the Linguistic Control Rule(LCR). The algorithm of th control is made of the LCR, and th control of an object is performed by processing this algorithm implementing a computer. in this thesis, the fuzzy controller of the ship's steering system is devided into two systems, namely FC1 and FC2, according to their control function. FC1 is for the course keeping steering, wheress FC2 is for the altering of s ship's course. The characteristics of the control system were investigated through the digital computer simulation and the results were compared with those of the conventional steering system. It was found that the fuzzy control was more efficient than the conventional auto pilot system.

• Nuclear Engineering and Technology
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• 제51권1호
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• pp.155-162
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• 2019

To reduce the secondary damage caused by leakage accidents in plant piping systems, a constant surveillance system is necessary. To ensure leaks are promptly addressed, the surveillance system should be able to detect not only the leak itself, but also the location of the leak. Recently, research to develop new methods has been conducted using cameras to detect leakage and to estimate the location of leakage. However, existing methods solely estimate whether a leak exists or not, or only provide two-dimensional coordinates of the leakage location. In this paper, a method using multiple cameras to detect leakage and estimate the three-dimensional coordinates of the leakage location is presented. Leakage is detected by each camera using MADI(Moving Average Differential Image) and histogram analysis. The two-dimensional leakage location is estimated using the detected leakage area. The three-dimensional leakage location is subsequently estimated based on the two-dimensional leakage location. To achieve this, the coordinates (x, z) for the leakage are calculated for a horizontal section (XZ plane) in the monitoring area. Then, the y-coordinate of leakage is calculated using a vertical section from each camera. The method proposed in this paper could accurately estimate the three-dimensional location of a leak using multiple cameras.

• Applied Biological Chemistry
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• 제40권4호
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• pp.294-300
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• 1997

수산가공 부산물을 식용자원으로 이용하기 위한 일련의 연구로서 오징어 내장유의 정제조건에 대하여 검토하였다. 오징어 내장유 100ml에 대하여 인산 3ml를 첨가하고 $60^{\circ}C$에서 30분간 교반하여 탈검한 다음 이것에 20% 수산화나트륨을 0.6% 과잉첨가한 후 탈산처리 하는 것이 효과적이었다. 탈산유에 대하여 10%에 해당하는 활성백토를 가한 후 감압하에 $100^{\circ}C$에서 20분간 탈색처리한 후 압력을 4torr 이하의 감압하에서 수증기증류법으로 $180^{\circ}C$에서 60분간 처리한 오징어 내장유가 물리, 화학적 성상이 가장 우수하였다. 정제유의 산값, 과산화물값 및 색도는 각각 0.20, 0.8 meq/kg 및 0.019이었다. 정제유의 포화지방산에 대한 고도불포화지방산의 비율은 1.28이었고, 주요 구성 지방산은 16 : 0, 18 : 1n-9, 20 : 5n-3 및 22 : 6n-3 등으로 기능성이 우수하였다.

• Journal of the Korean Wood Science and Technology
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• 제44권3호
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• pp.457-476
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• 2016

본 연구에서는 목재의 열처리가공에 대하여, 문헌 연구를 통하여 이와 관련된 주요 이슈 및 기술 동향을 조사하였다. 산업적으로 이용되는 주요 열처리기술은 네덜란드의 Plato-process, 프랑스의 Retification process, 독일의 OHT-process, 및 핀란드의 Thermowood process 등이었다. 열처리 공정상의 주요 영향인자들은 대상 수종, 가열 온도, 시간, 열전달 매질(air, 증기, 진공, 질소, 오일 등)이며, 이들 인자들을 변수로 한 최적조건 탐색 등의 연구가 주류를 이룬다. 열처리 목재는 치수안정성 증가, 중량 및 강도 감소, 부후균에 대한 내후성 향상에 변이, 변색균 및 해충에 대해 불충분한 저항성 등의 특징을 가진다. 열처리 목재의 내후성 향상을 위해 각 수종에 적합한 열처리 공정과 처리조건 탐색의 필요성이 시사되었다. 지속가능한 환경보존 및 목재자원 절약을 위해 열처리 목재의 새로운 용도 개발 및 이용 확대 노력이 반드시 필요한 과제인 것으로 고찰되었다.

• 한국수산과학회지
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• 제21권4호
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• pp.225-231
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• 1988

정어리유의 고도불포화지질을 일상식생활을 통하여 효과적으로 이용하기 위하여 정제정어리건의 제조를 위한 탈산, 탈색, 탈취 등의 정제조건을 검토한 결과를 요약하면 다음과 같다. 1. 정어리유의 탄산은 알칼리처리가 효과적이었으며 2M NaOH용액을 $0.5\%$ 과잉첨가하고 $30^{\circ}C$, 30분처리가 적조건이었다. 일반적으로 행하는 인산처리는 탈검에 효과가 없었다. 2. 탈색은 산성백토만을 기름의 $5\%$정도로 첨가하고 감압하에서 $60^{\circ}C$ 20분간 처리하는 것이 가장 효락적이었다. 3. 탈취는 수증기증류가 효과적이었으며 4torr 이하로 감압하면서 $180^{\circ}C$ 이하의 온도에서 하는 것이 바람직하였고 $200^{\circ}C$ 이상에서는 현저한 요오드가의 감소와 지방산조성에 변화를 초래하였다.