• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1995.05a
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• pp.85-92
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• 1995

HTPB/AP/Al이 기본 조성인 ADP 302 혼합형 추진제를 대상으로 4종의 금속선(Ag, Cu, Al, Ni-Cr)을 삽입하여 금속선 직경(0.1mm~0.8mm)별로 압력에 따른 금속선과 인접한 추진제의 연소 속도($r_w)를 측정하여 금속선 삽입 추진제의 연소 속도 증가비($r_w$/$r_sb$)와 압력 지수( n )의 변화를 고찰한 결과 금속선 종류에 따른 연소 속도 증가비($r_w$/$r_sb$)는 Ag> Cu>Al>Ni-Cr선을 삽입한 추진제의 순으로 나타났고 금속선의 열확 산 계수의 크기순과 일치하였다. Buckingham $\pi$ 이론을 적용한 무차원 해석으로부터 실험식을 구하여, 이 실험식에 의해 계산된 ($r_w)와 실험으로부터 얻어진 ($r_w)를 서로 비교하여 본 결과 잘 부합됨을 알 수 있었다. 또한 금속선 수에 따른 추진제 그레인의 연소 면적을 해석적으로 계산하여,($r_w$/$r_sb$)가 2, 3, 4, 5 배로 증가함에 따른 시간에 따른 연소 면적 증가비의 변화를 금속선 수에 따라서 비교하여 본 결과 정상 상태에서의 그레인의 연소 면적의 증가비($A_b$/$A_0$)는 금속선에 인접한 추진제의 연소 속도 증가비($r_w$/$r_sb$)와 일치했으며, 정상 상태의 연소 면적 증가비는 삽입된 금속선의 수와는 무관하며 정상 상태에 도달하는 시간에만 영향을 주는 것으로 나타났다.

• Korean Journal of Materials Research
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• v.3 no.6
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• pp.661-667
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• 1993

Effects of $SiH_4//WF_6$(=R) ratio on the electrical properties of W films such as resistvity, contact resistance, junction leakage current in the selective W CVD technology for contact barrier metal were investigated with the emphasis on the role of $\alpha$-W Resistivity of W increases with increasing R, which is primarily due to the phase transformation from $\alpha$-W to , $\alpha$-W. $\alpha$-W found in the SiH4 reduced CVD W film is stabilized by Si incorporated into the W film rather than by oxygen. $\alpha$-W is found in the W film deposited on the Si substrate for high R, while $\alpha$-W is not found in the W film deposited on the TiN substrate even for high R. Also junction leakages increase with increasing R, which is caused not only by the vertical Si consumption but also the lateral Si consumption.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.258-260
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• 2006

비정질 합금재료와 페라이트를 사용하여 비접촉식 커플러를 제조하여 각각의 재료가 적용가능한 범위를 규명하고자 하였다. 비정질 합금재료에 비해 페라이트는 안정적인 특성을 발휘하는 주파수 대역이 좁으며, 낮은 포화자속밀도로 인해 내전류 특성이 떨어졌다. 즉 페라이트는 20 MHz 이하의 주파수 대역과 비정질 재료가 적용되는 선로보다 유입전류가 낮은 전력선에 적용 가능할 것으로 보인다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.10 no.4
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• pp.155-158
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• 1985

A simple active-R filter is proposed by utilizing only four resistors and two operational amplifiers. This filter has multi-functional characteristics and decreases the ratio of resistors. The sensitivity of $W_r$ and $Q_r$ as the parameter of filter is very low and the operating frequency of this active-R filter is possible in the high frequency. The integration of this active-R filter is easy due to the decrease in the number of resistors and the lowering of the ration of resistors. The experiment shows that all the characteristics of this active-R filter are in accordance with thory.

• Korean Journal of Poultry Science
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• v.11 no.2
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• pp.115-125
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• 1984

The Waste Rice Straws (W.R.S.) after cultivation with the Pleurotas Ostreatus SACCARDO was substituted for wheat bran in the broiler ration. The results of the experiment 1 and 2 obtained were summerized as follows; 1. The content of C. protein in the W.R.S. showed 1.5% higher value than that in the rice straw. No change was detected in the content of C. fat. However the content of C. fiber and N.F.E in W.R.S. decreased in comparision with those of raw rice straw. 2. The treated groups were inclned to rapid gain of body weight, especially the 4% W.R.S. group had been showed significatly higher value of gain than the control and 6% treated groups (p＜0.05 ). 3. No significant differences were observed in the amount of feet intake among experimental groups, even if the treated groups showed slightly higher intake than control group. 4. The treated groups in W.R.S. were inferior to the control group in feed intake but there were no significant differences. 5. The methionine in W.R.S. was the only amino acid which contained similar quantity of wheat brans. 6. To extend the amount of W.R.S. in broiler ration the 6% of W.R.S. was substituted for wheat bran and methionine mixture was added. No significance differences had been showed in weight gain, feed intake and feed efficiency between control and treated groups. Even though the treated groups showed more feed intake and lower weight gain in comparision with control group. 7. The methionine added group showed adverse effect in economics of production (p＜0.01) because of high cost of the methionine mixture, Therefore less than. 6% of the WRS could be substituted for wheat bran. According to the results of the experiment 1 and 2 it could be concluded that maximum use of the W.R.R. as substitute for wheat bran was less than 4% of the ration.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.5
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• pp.529-539
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• 2000

This paper proposes a prefetch-based disk buffer management algorithm, which we call W2R (Veighingjwaiting Room). Instead of using elaborate prefetching schemes to decide which blockto prefetch and when, we simply follow the LRU-OBL (One Block Lookahead) approach and prefetchthe logical next block along with the block that is being referenced. The basic difference is that theW2R algorithm logically partitions the buffer into two rooms, namely, the Weighing Room and theWaiting Room. The referenced, hence fetched block is placed in the Weighing Room, while theprefetched logical next block is placed in the Waiting Room. By so doing, we alleviate some inherentdeficiencies of blindly prefetching the logical next block of a referenced block. Specifically, a prefetchedblock that is never used may replace a possibly valuable block and a prefetched block, thoughreferenced in the future, may replace a block that is used earlier than itself. We show through tracedriven simulation that for the workloads and the environments considered the W2R algorithm improvesthe hit rate by a maximum of 23.19 percentage points compared to the 2Q algorithm and a maximumof 10,25 percentage feints compared to the LRU-OBL algorithm.

• Journal of Bio-Environment Control
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• v.25 no.3
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• pp.139-145
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• 2016

The objective of this study was to compare the growth and light use efficiency of red leaf lettuce grown under three types of combined light-emitting diodes (LEDs) and fluorescent lamps (FL) in a closed-type plant production system. The eighteen days-old lettuce seedlings of red leaf lettuce (Lactuca sativa L., 'Jeokchima') were transplanted to the close-type plant production system equipped with three types of combined LEDs with red (R, 655 nm), blue (B, 456 nm), green (G, 515 nm), and white (W, 456 nm + 558 nm) (R:B=8:2, R:W:B=8:1:1, R:G:B=8:1:1) and FL. The seedlings were grown under normal growth conditions ($20^{\circ}C$, $181{\pm}4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 12 h photoperiod) for four weeks. Lettuce plants grown under FL had significantly higher leaf shape index than those under all LED treatments. Although growth of shoots and roots was not show any significant difference among LED treatments, all of the LED treatments induced about 34% higher shoot fresh weight than that of the FL. On the other hands, the total power consumption of FL was 145 kW for 4 weeks, while the mean value of LED treatments was 54 kW, which was about 3 times lower value than that of the FL. The light use efficiency based on dry matter in LED treatments was about 34 mg/W and this was about 3.5 times higher energy saving value than the FL. In conclusion, this study showed that irradiation of optimal combined LEDs in closed-type plant production systems can improve the lettuce growth as well as maximize in light use efficiency through energy saving than the FL.

• Magazine of the Korean Society of Agricultural Engineers
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• v.12 no.3
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• pp.2019-2028
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• 1970

1. Experiments were made for the efficient plowing method by the 4 wheel tractor, the results are as follow; 1) In case of plowing of inner side of the field, the efficient turning method to be the smallest turning time is the $\Omega$-shaped turning method in the turning distance less than 2r (r is the minimum turning radius of the tractor), and also, it is the U-shaped turning method in the turning distance larger than 2r. 2) 2.5r is most efficient in the unit turning section 'w' on plowing of the inner side of the field. 3) In case of plowing of outer side of the field, intermitted plowing method is efficient in case of W>-0.0345 L + 35.84, and also, semi-followed plowing method is efficient in case of W<-0.0345 L + 35.84. 4) The smaller the width of outer side of outer side of the field 'I' is, the higher is the plowing efficiency, and it is estimated that the minimum value 2r is suitable to 'I' in plowing of inner side and outer side of the field. 2. Study on the correlation between the unit field and plowing efficiencies obtained the following results; 1) plowing efficienies increase generally according as length-width ratio L/W and area A increase. 2) Percent of increase of plowing efficiencies decreases generally according as length-width ratio and area enlarge. 3) The limit that change of T is large owing to L/W is 6 for 20 a, 5 for 30 a, 4 for 50 a, 3 for 80 a, less than 2.5 for 100 a, generally, in L/W-T curve. 4) Rate of change of T-A curve is similar to rate of change of $T=A-\frac{2}{3}$ curve in spite of influence of L/W. 5) In case that length-width ratio is more than 3, effects of increase of 10 a area influenced upon plowing efficiencies are as much as effects of about 5 increase of length width ratio without correlation of size of the field. 6) In case that length-width ratio is 2 to 3, effects of increase of 10 a area influenced upon plowing efficiencies are as much as effects of about 4 to 2 increase of length-width ratio without correlation of size of the field, and the effects decrease according as not only length-width ratio decreases but also area increases, generally.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1996.05a
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• pp.131-137
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• 1996

HTPB/AP/Al이 주성분인 2종의 혼합형 추진제를 대상으로 4종의 금속선(Ag, Cu, Al, Ni-Cr)윰 각각 삽입하여 금속선의 직경(0.1~0.8mm)과 연소 압력에 따른 금속선에 인접한 고체 추진제의 연소 속도 증가비($r_w$/$r_sb$)와 압력 지수(n)의 변화를 고찰하였다. 금속선을 추진제에 삽입함으로써 추진제의 $r_w$/$r_sb$ 는 크게 중가하였고, 1000 psia의 압력에서의 최대 6.59배 증가하였다. 그러나 녹는 점이 비교적 낮은 Al 선이나 Ag선은 금속선 직경이 작아짐에 따라 한계 직경에서 $r_w$가 급격히 감소하는 최대값이 존재하였다. 자연 발화 온도와 금속선으로 전달되는 열원인 연소 기체 불꽃 온도로 구성된 무차원군을 Buckingham pi 정리에 의해 구해진 $r_w$/$r_sb$ 에 대한 기존의 무차원 실험식에 추가로 적용하여 계산해 본 결과, 자연 발화 온도는 고려하지 않고 금속선의 녹는 점과 연소 기체의 불꽃 온도를 무시한 Hsing 의 실험식에 의해 계산된 결과보다 표준 편차가 45%이상 줄어듬을 알 수 있었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.243-246
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• 2004

W CMP 공정에서 abrasive 의 size 및 shape 에 따른 CMP 거동에 대해 관찰하였으며, 주요 제거 막질인 W 막질과 stopping layer 로 사용되는 Oxide 막질에 대한 압력(P)과 상대 속도(V) 영향성을 관찰하였다. CMP 제거량이 입자의 size 변화에 의존한다는 기존의 이론과는 달리 응집도(aggregate ratio) 변화가 주요 변수임을 밝혀 내었다. 한편, 각 막질에 대한 P,V 영향성 평가를 통해, 변형된 Prestonian equation 이 abrasive size 및 shape 에 상관없이 W 막질의 제거 거동을 설명하는데 중요한 역할을 수행함을 보였다. 그렇지만, W CMP 공정에서 stopping layer 로 사용되는 oxide 막질의 거동을 설명하는 데에는 어려움이 있었으며, 특히 P,V 에 의한 비선형적 removal rate(RR) 거동발생으로 인해 기존의 이론치와는 많은 차이를 나타내었다. 또한, abrasive size 와 shape 에 따라서도 복잡한 거동을 나타낸다.