• KSBB Journal
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• v.8 no.4
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• pp.358-363
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• 1993

The effect of ultrasound on the acid hydrolysis of inulin was studied under significantly mild reaction conditions, at which sugar degradation products were not detected. Reaction conditions were i the range of 50~$60^{\circ}C$ and 0.1~0.3%(w/w) of HCl concentrations. The effects of reactor position inside water bath and mechanical agitation under ultrasound were investigated. The production rates of fructose with/without ultrasound irradiation were compared. The activation energies for both control and ultrasound reaction were the same, i. e., 25kca1/mo1, and ultrasound enhancement was average 22%.

• Electronics and Telecommunications Trends
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• v.24 no.4
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• pp.112-125
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• 2009

언제부터인가 주위는 모두 "녹색" 물결로 뒤덥혀 버렸다. 그 중에서도 IT의 존재는 녹색 물결에 휩싸여 새로운 판로를 모색하고 있다. 데이터센터 역시 그 문제점은 수 년전부터 대두되어 왔고, 정책적으로 혹은 업계 자체적으로 데이터센터의 문제점을 해결하고자 많은 솔루션을 내고 있는 실정이다. 그린 데이터센터를 위한 견해는 먼저 비 IT영역으로 공조, 항온/항습 시설, 전력 배전 시설 등의 관점에서 접근하는 견해가 있고 IT영역으로 서버 자체에 대한 관점에서 접근하는 견해가 있다. 본 고에서는 데이터센터 내에서 IT 영역에 대한 전력 관리를 위하여 해야 될 역할에 대하여 언급하고자 한다. 특히 데이터센터 내 서버 자체의 전력 절감을 위한 방법에 대하여 논하고, 앞선 업체들 특히 IBM, Google, SUN 등의 동향으로부터 그린 데이터센터를 위한 방향을 모색해 보기로 한다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.174-174
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• 2011

외국제품과 거의 동등한 수성 상온/속건형 접착제를 개발하였다. 접착제 내구수명은 신뢰수준 80%, B10수명 5년 보증이 되었으며, 외산제품과 거의 동등한 속건성 향상 (30초 이내/0.3 Mpa 이상)이 되었으며 장기내구접착성 향상(1.0 Mpa 이상), 내환경성(내열 및 내구성)이 향상되었다. 항온/항습 주기 (최고 $80^{\circ}C$, 최저 $20^{\circ}C$)를 통해 장기 내구부착성 향상이 된 수성 접착제를 개발하였다.

• Korean Journal Plant Pathology
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• v.12 no.4
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• pp.402-406
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• 1996

Pythium 5종, 16균주를 공시하여 담수직파한 벼에 대한 병원성을 CMA 배지와 growth chamber 검정법에 의하여 검정한 결과 P. arrhenomanes 1398 균주가 가장 강한 병원성을 보였으며, 다음은 균주에 따라 차이가 있었으나 P. irregulare와 P. spinosum도 병원성이 강하였으며, P. dissotocum과 P. catenulatum의 균주는 병원성이 약하거나 없엇다. CMA 배지 검정때 P. arrhenomanes 1398 균주의 병원성은 주.dirks 2$0^{\circ}C$ 또는 3$0^{\circ}C$의 항온처리보다 주간 3$0^{\circ}C$, dirks 2$0^{\circ}C$의 변온 처리에서 높았다. Growth chamber 검정법으로 병원성을 검정할 때에는 벼알접종원을 이용하는 것이 효과적이었다.

• Journal of Welding and Joining
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• v.7 no.2
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• pp.25-34
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• 1989

The purpose of this work is to coat ZrO$_{2}$ - 8Y$_{2}$O$_{3}$ ceramic on the Al cast alloy(AC-8A) by using the plasma spray method. Two types of coatings which were composed of two and three layer coating were examined. Each coating powder was analyzed for shape and size distribution and X-ray diffraction pattern. For the coated layers, microstructural analysis and performance estimation which was composed of static thermal test, thermal cyclic test and thermal shock test were conducted.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1800-1803
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• 2015

기존의 센서가 컴퓨팅과 통신기능을 갖추게 되면서, 분산된 센서가 통신망을 통해 전달하는 현장의 물리량 변화를 직관적으로 판단할 수 있게 돕는 재사용 가능한 데이터 시각화 컴포넌트의 수요가 높다. 본 연구에서는 라즈베리파이를 IoT센서로 보고, 분산된 복수의 IoT센서들로부터 현장의 온도 값을 웹 서버에서 모아, 사용자가 클라이언트 단말을 통해 현장의 온도변화 상황을 직관성 있게 판단할 수 있도록 돕는 회귀분석 시각화컴포넌트를 개발하였다. 본 연구에서는 이종분산의 IoT 환경에서 다양한 브라우저를 지원할 수 있도록 Non-ActiveX 기반 데이터 시각화 컴포넌트 개발을 논한다. 본 연구의 결과는 단일의 온도센서가 보고하는 온도값을 현장의 온도값이라고 대표할 수 없는 항온항습 시설의 온도 감시제어 응용에서 본 연구 결과가 널리 활용될 것으로 본다.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_3
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• pp.1197-1204
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• 2023

Ti-alloy, a high-strength alloy material among the materials used in aircraft that are trending toward lighter weight, is classified as a difficult-to-cut material that requires a lot of energy for cutting. Cutting in a high-temperature environment is considered one means of making this possible, and various studies have been conducted on it. In particular, research on LAM (Laser Assisted Machining (LAM)), which utilizes laser heating of the cutting area, is being actively conducted. Before processing of the milling cutter begins, the temperature is raised locally by the laser irradiated through the laser head carrier, and the resistance during milling is reduced. Therefore, in this paper, in order to derive such conditions, we performed heat transfer analysis according to transfer conditions and compared it with actually applied test data to use it to establish appropriate processing conditions.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.853-860
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• 2012

To estimate potential use of fly ash in reducing $CH_4$ and $CO_2$ emission from soil, $CH_4$ and $CO_2$ fluxes from a paddy soil mixed with fly ash at different rate (w/w; 0, 5, and 10%) in the presence and absence of fertilizer N ($(NH_4)_2SO_4$) addition were investigated in a laboratory incubation for 60 days under changing water regime from wetting to drying via transition. The mean $CH_4$ flux during the entire incubation period ranged from 0.59 to $1.68mg\;CH_4\;m^{-2}day^{-1}$ with a lower rate in the soil treated with N fertilizer due to suppression of $CH_4$ production by $SO_4^{2-}$ that acts as an electron acceptor, leading to decreases in electron availability for methanogen. Fly ash application reduced $CH_4$ flux by 37.5 and 33.0% in soils without and with N addition, respectively, probably due to retardation of $CH_4$ diffusion through soil pores by addition of fine-textured fly ash. In addition, as fly ash has a potential for $CO_2$ removal via carbonation (formation of carbonate precipitates) that decreases $CO_2$ availability that is a substrate for $CO_2$ reduction reaction (one of $CH_4$ generation pathways) is likely to be another mechanisms of $CH_4$ flux reduction by fly ash. Meanwhile, the mean $CO_2$ flux during the entire incubation period was between 0.64 and $0.90g\;CO_2\;m^{-2}day^{-1}$, and that of N treated soil was lower than that without N addition. Because N addition is likely to increase soil respiration, it is not straightforward to explain the results. However, it may be possible that our experiment did not account for the substantial amount of $CO_2$ produced by heterotrophs that were activated by N addition in earlier period than the measurement was initiated. Fly ash application also lowered $CO_2$ flux by up to 20% in the soil mixed with fly ash at 10% through $CO_2$ removal by the carbonation. At the whole picture, fly ash application at 10% decreased global warming potential of emitted $CH_4$ and $CO_2$ by about 20%. Therefore, our results suggest that fly ash application can be a soil management practice to reduce green house gas emission from paddy soils. Further studies under field conditions with rice cultivation are necessary to verify our findings.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.2
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• pp.69-76
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• 2002

To study the behavior of $NH_4{^+}$ of CMS (condensed molasses solubles) in soil, a laboratory incubation experiment was conducted during a period of up to 21 days at $25^{\circ}C$. The $NH_4{^+}$ of CMS was labeled with $^{15}N$ and was applied to water-unsturated and water-saturated conditions. Soil pH was gradually decreased from 6.1 to 5.4 under unsaturated condition. However, soil pH was increased to 6.5 within 2 days under saturated condition and then was constant. The concentration of ammonium was decreased 3 times faster under unsaturated condition than under saturated condition. The concentration of nitrate was increased from 17.4 to $155.4mg\;kg^{-1}$ under unsaturated condition. But concentration of nitrate was kept with low(below $8.0mg\;kg^{-1}$) under saturated condition. During the incubation, 52.4% of $^{15}NH_4{^+}$ applied was existed in the form of $NO_3{^-}$ by nitrification under unsaturated condition. Most of applied nitrogen was immobilized within 4 days of incubation. On 21 days of the incubation the percentage of immobilized nitrogen derived from $^15NH_4{^+}$(NDFA) was 19.6% under unsaturated condition and 17.0% under saturated condition. The percentage of unaccounted N, which was lost by denitrification, was 28.4% under unsturated condition and 67.6% under saturated condition.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.1
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• pp.55-61
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• 1987

A series of laboratory experiments were carried out to find the effects of soil organic matter contents, soil temperature, pH values, kinds and amount of nitrogen fertilizers on the denitrification-$N_2O$ gas evolution-. The results obtained were summarized as follows: 1. Denitrification rate, amount of $N_2O$ gas evolution, was influenced the order of organic matter contents>soil temperature>pH values>kinds of N-fertilizer>levels of N-fertilizer. 2. The highest dentrification rate was observed in organic matter content of 3.0%, pH values at 6.0 with application of $KNO_3$ at levels of 20 mgN/100g soil. 3. For the evolution of I mole $N_2O$ gas, averaged carbon consumption was obtained as 0.5 mole in all these experiment condition. However, the highest carbon consumption rate was obtained in organic matter contents for 1.0% with application of $(NH_4)_2SO_4$ at levels of 10 mgN/100g soil (1.06 mole) while lowest carbon consumption rate was obtained in organic matter contents for 3.0% with application of $KNO_3$ at levels of 20 mgN/100g soil (0.13 mole). 4. According to Michaelis-Menten's equation, the V/2 values for evolution of $N_2O$ gas was estimated by progress curve. The results obtained was as 550 ug for $(NH_2)_2CO$ and 1100 ug $N_2O/100g$ soil by application of $KNO_3$ in organic matter contents of 1.0% soil. On the other hand, when the application $(NH_4)_2SO_4$ the V/2 values of $N_2O$ gas was obtained as the amount of 490 ug/100g soil while V/2 values of $N_2O$ gas by application of $KNO_3$ was on the linear line in soil organic matter contents of 3.0%.