• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.75-80
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• 2002

This study is to investigate the characteristic on the resistance of chloride infiltration concrete containing limestone powder The variables are the substitution ratio of slag powder and limestone powder. In order to study the effect slag powder and limestone powder, all mixtures were prepared at a fixed water/cement ratio, slump, and entrained air quantity. As results show that the strength and the resistance of chloride infiltration in concrete substitution 10%, 20% limestone powder, and 30%, 40% slag powder are positive.

• 디지털융복합연구
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• 제15권11호
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• pp.199-207
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• 2017

기술 진보 및 융합과 함께 매우 빠르게 변화하는 사업 환경은 기업의 성공에 있어서 연구개발(R&D)의 역할을 더욱 더 중요하게 하고 만들고 있다. 본 연구는 기업 수준의 683개 중소 벤처기업 데이터를 대상으로 최소 자승 회귀분석을 실시하여 다음과 같은 4가지 주요 사항을 새롭게 조명한다. 첫째, 중소 벤처기업의 외부 R&D 협력 네트워크의 다양성은 기술 개발로 인한 수입 대체에 정(+)의 영향을 준다. 둘째, 기업 부설 연구소의 존재는 중소 벤처기업의 외부 R&D 협력 네트워크의 다양성이 기술 개발로 인한 수입 대체에 주는 양(+)의 영향을 조절한다. 셋째, 중소 벤처기업의 외부 R&D 정보 네트워크의 다양성은 기술 개발로 인한 수입 대체에 정(+)의 영향을 미친다. 넷째, 기업 부설 연구소의 존재는 중소 벤처기업의 외부 R&D 정보 네트워크의 다양성이 기술 개발로 인한 수입 대체에 주는 양(+)의 영향을 조절한다.

• Transactions on Electrical and Electronic Materials
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• 제12권2호
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• pp.64-67
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• 2011

The effect of Ta substitution on the crystal structure, ferroelectric, and piezoelectric properties of $Bi_{0.5}(Na_{0.82}K_{0.18})_{0.5}Ti_{1-x}Ta_xO_3$ ceramics has been investigated. The Ta doping resulted in a transition from coexistence of ferroelectric tetragonal and rhombohedral phases to an electrostrictive pseudocubic phase, leading to degradations of the remnant polarization, coercive field, and piezoelectric coefficient $d_{33}$. However, the electricfield-induced strain was significantly enhanced by the Ta substitution-induced phase transition and reached a highest value of $S_{max}/E_{max}$ = 566 pm/V under an applied electric field 6 kV/mm when 2% Ta was substituted on Ti sites. The abnormal enhancement in strain was attributed to the pseudocubic phase with high electrostrictive constants.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.233-238
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• 1998

For substitution for crushed sand, high strength aggregate for cement and concrete using coal ash as a main material was prepared and then compared its physical properties with those of crushed sand. Effect of mix proportion change of raw materials on the property of aggregate was checked. On the basis of these experimental results we are going to comprehend the reutilization of coal ash and utilize a basic data for judging possibility the substitution of crushed sand.

• 한국축산시설환경학회지
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• 제3권1호
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• pp.19-26
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• 1997

Composting has recently become popular as a means of recycling swine manure into products for sale off the farm, but bulking agent(usually sawdust) are expensive and availability is limited. This experiment was conducted to investigate the effect of fly ash as a bulking agent on the composting of swine manure and to analyze the effective substitution rate of fly ash mixed with swine manure for sawdust. Fly ash was able to be substituted for sawdust and the most effective substitution rate are 50% of sawdust. According to the results the advanced research and development are required, the effect of swine manure with fly ash on the soil properties, forage composition and animal performance.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.1017-1022
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• 2001

Dam concrete for pumped storage power plants should have sufficient durability in repetitive wet and dry conditions and abrasion due to water level fluctuation and also in freezing and thawing resistance as well as permeability capacity. This study presents various experimental results to enhance the durability of face slab concrete in CFRD(concrete faced rockfill dam) by varying the fly ash substitution such as 0%, 15%, 20% and 25% and polypropylene such as 0%, 0.1%. The effect on durability of concrete corresponding to the increasing amount of fly ash and polypropylene was evaluated and the optimum quantity of fly ash and polypropylene substitution was recommended. The results show that 20% of fly ash substitution and 0% of polypropylene were found out to be an optimum quantity to achieve excellent performances in durability for face slab concrete in CFRD.

• Journal of Advanced Marine Engineering and Technology
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• 제27권6호
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• pp.704-713
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• 2003

The effect of partial substitution of tungsten for molybdenum on the microstructure and corrosion resistance in 22Cr-5Ni-3Mo duplex stainless steel(DSS) aging heat treated in a temperature range of 600~$1000^{\circ}C$ has been investigated. Electrochemical tests were carried out for the evaluation of corrosion resistance. Aging treatment had hardly influenced the general corrosion resistance. With the increase of aging time, the pitting corrosion resistance of the DSS had decreased, After aging for 2min at 700~$900^{\circ}C$, the pitting potential of the 3Mo steel decreased remarkably, while that of the W-substituted steel hardly changed. During aging. the intermetallic $\sigma$ and secondary austenite ($\gamma_2$) phases were precipitated. and the pitting corrosion and intergranular corrosion resistance were significantly decreased after aging at 700~$750^{\circ}C$ for 10 h, which could be caused by the $\gamma_2$ formation. The ${\gamma}$$_2$ phase could affect the depletion of molybdenum and chromium in the $\gamma_2/\alpha and \gamma_2/\sigma$ boundaries.

• 한국산업융합학회 논문집
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• 제7권3호
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• pp.299-303
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• 2004

A systematic investigation for the reactivity and solvent effect was studied on the reaction of optical resolving agents with the optically active assistant compounds. The reaction rate constants of the nucleophillic substitution reactions were determined by means of conductometric method The linear solvent energy relationship based on the solvent parameters and the thermodynamic parameters was discussed on the reactions of various physiological active compounds and optical resolving agents The reaction mechanism was discussed from the kinetic results compared with the optical purity.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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• pp.161-164
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• 2004

In this study, to develop the composition ceramics for the Ultrasonic vibrator, $Pb(Mn_{1/3}Nb_{2/3})O_3Pb(Zr.Ti)O_3$ system ceramics were manufactured as a function of PCN substitution. Its dielectric and piezoelectric characteristics were investigated. With increasing the amount of PCN substitution, electromechanical coupling factor(kp) were increased until 3mol% PCN and that after decreased. mechanical quality factor(Qm) showed the maxinum value at 2mol% PCN. Eletromechanical coupling factor, mechanical quality factor and dielectric constant were showed optimum value at PCN 2mol% as 0.58, 1630 and 1407, respectively for ultrasonic vibrator applications.

• 한국식품조리과학회지
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• 제33권3호
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• pp.333-341
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• 2017

Purpose: This study investigated the quality characteristics of vegetable pancake prepared with various levels of barley flour. Methods: The pH level and spreadability of the batters as well as the color, texture, and sensory evaluation of the vegetable pancake were analyzed. Results: The results show that spreadability of batter significantly decreased as the substitution amount of barley flour increased (p<0.001). The pH level of the batter significantly decreased as the substitution amount of barley flour increased (p<0.001). Redness and yellowness increased as the substitution amount of barley flour increased. For texture, the sample groups with substituted barley flour showed high characteristics of hardness, gumminess, and chewiness. Principal component analysis showed that the sample group with a high substitution amount of barley flour was characterized by relatively high darkness, roasted grain aroma, bitterness, astringent, and chalkiness. Acceptance test found that the sample group with 15% barley flour received higher acceptance than the sample group with 0% barley flour in terms of color, texture, and overall acceptance. Conclusion: Acceptance test found that the sample group with 15% or 30% of barley flour had significantly higher or similar acceptance attributes than the sample group without barley flour, which suggests the possibility of developing vegetable pancake with barley flour.