• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.175-180
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• 1999

The heating system of korea apartment house is called Ondol. The surface finishing mortar of this floor system typically used the cement based mortar, where the surface finishing mortar easily appears the crack. To order to crack control, the cement that added expansive additive used to reducing dry-shrinkage. For the surface finishing mortar, the types of shrinkage is known as plastic shrinkage, dry-shrinkage and autogenous This experimental study is to investigate the difference on dry-shrinkage of the cement that added expansive additives and OPC. The test method is varied the ration of water/cement (W/C) and the ratio of sand/cement(S/C). For OPC, The increase of the ratio of S/C is reduced dry-shirnkage but for the cement that added expansive additives, the increase of the ratio of S/C is augmented dry-shrinkage For OPC, The increase of the ratio of W/C is augmented dry-shrinkage but for the cement that added expensive, the increased of the ratio of W/C is reduced dry-shrinkage.

• 한국영양학회:학술대회논문집
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• 한국영양학회 1992년도 춘계심포지움 및 발표논문 초록
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• pp.30-31
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• 1992

• JSTS:Journal of Semiconductor Technology and Science
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• 제8권4호
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• pp.302-310
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• 2008

This paper puts forward an advanced consideration on the design of scaled multiple-gate FET (MuGFET); the aspect ratio ($R_{h/w}$) of the fin height (h) to fin width (w) of MuGFET is considered with the aid of 3-D device simulations. Since any change in the aspect ratio must consider the trade-off between drivability and short-channel effects, it is shown that optimization of the aspect ratio is essential in designing MuGFET's. It is clearly seen that the triple-gate (TG) FET is superior to the conventional FinFET from the viewpoints of drivability and short-channel effects as was to be expected. It can be concluded that the guideline of w < L/3, where L is the channel length, is essential to suppress the short-channel effects of TG-FET.

• 한국건설순환자원학회논문집
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• 제6권1호
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• pp.1-7
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• 2018

본 연구에서는 산업부산물을 다량 활용한 소일콘크리트의 유동성 및 강도발현에 대한 결합재-흙의 비(B/S) 및 물-결합재비(W/B)의 영향을 평가하였다. 보통 포틀랜드 시멘트의 부분 치환재로서 바이패스 더스트 10%, 고로슬래그미분말 40%, 순환유동층 플라이애시 25%가 사용되었다. 저시멘트 결합재와 함께 사질토 또는 점성토를 사용하여 18 소일콘크리트 배합이 실험되었다. 실험결과 소일콘크리트의 유동성은 대상토(점성토 또는 사질토)의 종류에 관계없이 동일한 W/B에서 B/S가 클수록 증가하였다. 압축강도는 점성토 콘크리트보다 동일 배합조건을 갖는 사질토 콘크리트에서 컸다. 산업부산물 다량 활용 소일콘크리트의 배합은 압축강도 및 고유동성을 고려하면 대상토에 관계없이 B/S가 0.35 그리고 W/B는 175%가 추천될 수 있었다.

• 대한토목학회논문집
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• 제3권3호
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• pp.107-116
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• 1983

다짐 에너지 변화(變化)에 따르는 화강풍화토의 입도변화(粒度變化) 및 파쇄량(破碎量)이 투수성(透水性)에 미치는 영향에 대해 연구하였다. 토립자(土粒子)의 파쇄(破碎)는 토립자(土粒子)의 표면적비(表面積比)($S_w{^{\prime}}/S_w$)로서 나타냈고, 다짐에너지를 변화(變化)시키면서 실시한 다짐 시험결과(試驗結果) 만들어진 시료(試料)에 변수위투수시험을 행(行)하여 투수계수와 최적함수비(最適含水比)와의 관계를 조사(調査)하였다. 그 결과(結果) 다음과 같은 사항을 알 수 있었다. (1) 다짐에너지의 증대(增大)에 따라 파쇄(破碎)가 커지고 간극비(間隙比)가 감소되고 건조밀도는 영공극곡선(零空隙曲線)에 평행(平行)하게 증대(增大)된다. (2) 표면적비(表面積比)는 다짐회수에 관계없이 $S_w{^{\prime}}/S_w=0.33(P)^{0.96}$로 표시(表示)할 수 있다. (3) 입자파쇄(粒子破碎)가 가장 크게 일어나는 입경(粒徑)은 0.5~1 mm 범위이다. (4) 최적함수비(最適含水比) 상태에서 투수계수 K와 간극비함수(間隙比函數) $\frac{e^3}{1+3}$와의 관계는 양면대수지상(兩面對數紙上)에서 직선 관계가 성립(成立)한다. (5) 최적함수비(最適函數比) 상태에서 다짐에너지가 증가(增加)되면 200번(番)체 통과량(通過量)은 거의 직선적으로 증가(增加)되며 표면적비(表面積比)의 증대(增大)는 투수성(透水性)의 저하(低下)를 갖고온다.

• 한국건설순환자원학회논문집
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• 제6권1호
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• pp.16-24
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• 2018

본 연구에서는 3D 프린팅 공법 적용을 위한 콘크리트 기초 레올로지 분석을 목적으로 실험을 수행하였다. 콘크리트 구성성분 중 유동특성에 큰 영향을 미치는 인자(W/B, binder Type, replacement ratio, super plasticizer dosage)의 변화에 의한 레올로지 특성(rheological properties)을 실험적으로 분석하였다. 실험은 페이스트와 모르타르 크게 두 가지 인자로 구분하여 수행하였다. 페이스트 실험에서는 W/B, binder type, replacement ratio, super plasticizer dosage를 주요 변수로 설정하여 레올로지를 분석했다. 모르타르 실험에서는 W/B와 sand ratio에 따른 레올로지 특성을 분석했다. 결과적으로 W/B가 증가될수록 viscosity가 감소하였으며, FA를 치환할 FA 비율이 증가됨과 함께 viscosity가 증가하였다. 유동성 증가를 위해서는 SF를 5%만 치환해도 shear stress를 감소시키며 viscosity는 약 83%까지 감소되었다. 모르타르 레올로지 평가를 통해 W/B 30~40% 구간에서 큰 폭의 변화가 일어나는 임계치 구간이 존재하는 것으로 분석됐다. 또한 동일 W/B 내에서는 sand 비가 50~60% 구간에서 shear stress가 두 배 이상 증가하는 임계 구간이 존재하는 것으로 분석됐다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.971-972
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• 2006

We have demonstrated Carbon Nanotube Back Light Unit (CNT-BLU) which has a triode structure. Local dimming scheme was introduced to the BLU driving system. With this driving method, contrast ratio enhanced 20 times higher than that of conventional Cold Cathode Fluorescent Lamp (CCFL) BLU.

• Journal of Nutrition and Health
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• 제26권5호
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• pp.513-523
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• 1993

In this experiment, we investigated the hypolipidemic and antithrombotic effects of rats fed diets with different common oils in Korea for different feeding periods(4 weeks or 12 weeks), using Korean sesame oil, perilla oil, rice bran oil and mixed oil. W-3/w-6 ratio of each group was 0.001, 1.44, 0.03 and 0.112, respectively. P/S ratio of each group was 9.64, 10.49, 5.58 and 1.68, respectively. The result were as follows: 1) According to the age, body fat accumulation was increased. 2) Perilla oil(w-3 rich) decreased total lipid, triglyceride and total cholesterol, and increased HDL/total cholesterol ratio. 3) With regard to the compositono of platelet fatty acids, Perilla oil increased w-3/w-6 ratio of the platelet. Perilla oil lengthened bleeding time and decreased MDA(MalonDAdehyde) formation which determined in place of Thromboxane A2(TXA2) in platelet. This result can suggest that linoleic acid of perrilla oil seem to supress the conversion of linoleic acid to arachidonic acid(AA 20:4, w-6) and eicosapentaenoic acid(EPA, 20:5, w-3) trannnsformed from linolenic acid to suppress the conversion of arachidonic acid to TXA2. Since TXA2 is platelet-aggregating and vasoconstricting agent, the reduction of TXA2 tgeneration by platelet with increased linolenic acid intakes shows prologed bleeding time. In conclusion, w-3 rich perilla oil has strong hypolipidemic and antithrombotic effects by changing fatty acid profiles of the platelet.

• Journal of Nutrition and Health
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• 제26권5호
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• pp.524-531
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• 1993

In this experiment, we investigated the changes of erythrocyte feature and Ca concentration in rat fed the diet containing different common oils in Korea for different feeding periods(4 weeks or 12 weeks), using Korea sesame oil, perilla oil, rice bran oil and mixed oil. W-3/w-6 ratio of each group was 0.001, 1.44, 0.03 and 0.112, respectively. P/S ratio of each group was 9.64, 10.49, 5.58 and 1.68, respectively. Perilla oil(w-3 rich) increased w-3/w-6 ratio of erythrocyte membrane, decreased the amount of trapped Ca and inhibited the decrease of cell volume. These results indicate that in maybe increase erythroyte fluidity and deformability, and affect erythrocyte function. In conclusion, w-3 rich perilla oil affects erythrocyte feature.

• 한국분말재료학회지
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• 제5권1호
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• pp.42-49
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• 1998

A study on the improvement of the impact energy in 93W heavy alloy with a Ni/Fe ratio of 9/1 has been carried out as a function of heat treatment temperature. The obtained results were compared to that of the traditional alloy system in which the Ni/Fe ratio is 7/3 or 8/2. With increasing heat treatment temperature from 1150 to 125$0^{\circ}C$, the impact energy of the alloy with the Ni/Fe ratio of 9/1 is remarkably increased from 42 to 72 J, which is higher than that of traditional alloy, up to 118$0^{\circ}C$ and then saturated. Fracture mode was also changed from brittle W/W boundary failure to W cleavage. The temperature showing the dramatic shrinkage by dilatometric anaysis of the heavy alloy with Ni/Fe ratio of 9/1 was found to be 1483 $^{\circ}C$, which is higher than that (146$0^{\circ}C$) of the heavy alloy with Ni/Fe ratio of 7/3. Auger Electron Spectroscopy showed that the segregation of impurities, such as S, P, and C in W/W grain boundary was considerably decreased with increasing heat treatment temperature from 1150 to l18$0^{\circ}C$. From the above results, it was found that the impurity segregation in W/W grain boundary played an important role on the decrease of impact properties, and the heat treatment temperature should be appropriately chosen, as considering the Ni/Fe ratio of the alloy, in order to get good impact properties.