• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.641-644
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• 2006

Considering properties of the low-heat concrete mixed with the blended cements, the influences compared blended cements with ordinary portland cement made experiments on. (1) Blended cements were superior to OPC in the fresh concrete flow that the use of blended cements reduced chemical admixture. (2) The more the use of additive increase, the more bleeding happens. So it is considered to heights, order, and rate of placement, curing methods and so on. (3) The use of blended cements increase long term strength after 28 days, but decrease early strength and durability. So it is considered to the curing methods and early frost damage, and endurance limit.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.671-674
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• 2005

In this study, it is examined the properties of early strength of concrete mixed with polycarboxylate superplasticizer. For this experiment, it is analyzed that the slump and strength properties according to the mixture factors, compared with cements and superplasticizers of each company and curing temperature($15,\;20^{\circ}C$). (1) The slump loss of concrete used polycarboxylate superplasticizer(rapid strength type) showed $0.5\~1.5cm$, it is judged that slump loss according to the time lapse can be minimized. (2) The performance of polycarboxylate superplasticizer kept up consistency and accelerated strength development. it is possible to reveal 12MPa within $18\~20$hours at $20^{\circ}C$ curing, but impossible within 24hours at $15^{\circ}C$. (3) It is necessary to studies about rapid strength development in the low temperature.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1447-1450
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• 2005

Carbon nanotube field emission display devices were fabricated using screen printing techniques. The CNT pastes are composed of organic binder, CNT, and additive materials such as glass frit, silver or ITO powders. The change in mixing ratio of various organic binders in CNT paste varied the electron emission characteristics. With increasing the contents of additive materials in CNT paste, turn-on field were increased, leading to decrease in electron emission current. The post-treatment process in this study induced the vertical alignment of carbon nanotubes on glass, resulting in the improvement of electron emission uniformity.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.77-78
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• 2011

This paper presents a basic study which is to develop concrete cylinder moulds for a proficiency testing compressive strength of concrete among laboratories accredited Korea Laboratory Accreditation Scheme(KOLAS). The concrete cylinder moulds sufficiently have homogeneity for a proficiency testing which is a means of assessing the ability of laboratories to competently perform specific test and measurements. The concrete compressive strength specimens placed different consolidation methods were analyzed by a statistic technique. The methods of consolidation are rodding, and internal or external vibration.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.259-260
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• 2010

This study is to investigate each mix property and physical properties and reduction properties of heat of hydration as basic experiment of reviewing the applicability of low calorific concrete.

• Natural Product Sciences
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• v.10 no.1
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• pp.29-31
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• 2004

A new method for the quantitative determination of fucosterol in the marine algae Pelvetia siliquosa by gas chromatography was established. A HP-1 column programmed as $200^{\circ}C\;(5\;min)\;{\rightarrow}\;5/min\;{\rightarrow}\;280^{\circ}C\;(10\;min)$ was developed. The analysis of fucosterol in P. siliquosa was successfully carried out within 30 min.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.197-200
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• 2012

Concrete has cracks from shrinkage that necessarily result from in hardening process. Shrinkage-reduced concrete developed for crack reduction was utilized at a sample construction project. As a result, it is confirmed that crack initation ratio was remarkably reduced when compared to the case of normal concrete utilization. Additional sample project is supposed to use delay joints as well as srinkage-reduced concrete. Subsequently, the result will be reported. The greatest factor which affects in drying shrinkage is unit quantity of water. However, there are a lot off difficulties in field supervision because proper measuring means is not presented in present standard. Therfore, problems depending on ready-mixed concrete concrete companies should be improved by preparing the related standard assoon as possible.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.211-212
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• 2012

Over the years, the recovery of the domestic construction market, which does not appear on the reverse, but rather due to a surge of construction materials cost of the construction sector is experiencing greater difficulties. Cement raw materials in the manufacturing process, if some of the waste recycling, cites quality control for products and measures for the thorough management is needed. In this study, three companies of the past four years in the production of cement against doejin physical performance test results conducted yearly and seasonal trends by analyzing changes in the years to review the cement for cement to utilize as a basis for management points is.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.191-193
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• 2002

최근, 전기품질에 관한 중요성과 EMI에 의한 규정이 강화되면서 PFC 컨버터에 관한 연구가 많이 이루어지고 있다. 본 연구에서는 matlab을 활용하여 3상 PFC 컨버터를 효율적으로 시뮬레이션하는 연구를 수행한다. 단위역률을 위한 3상 컨버터 PFC 제어는 링크전압제어부, 전류제어부, SVPWM 제어부로 구성된다. 3상 PFC 컨버터를 matlab/simulink로 구성하여 시뮬레이션을 수행한 결과. 상전압과 상전류의 위상이 일치하여 단위역률이 잘 실현됨을 나타내고 있다. 본 연구는 PFC 컨버터의 설계 및 유사회로의 시뮬레이션에 유용하게 활용될 것이다.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.141-154
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• 2009