• Structural Engineering and Mechanics
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• v.84 no.3
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• pp.393-411
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• 2022

A high-performance reactive powder concrete (RPC) has been readied alongside river sand, with 1.25 mm particle size when under the condition of 80C steam curing. As a heat and sound insulation, expanded perlite aggregate (EPA) provides economic advantages in building. Concrete containing EPA is examined in terms of cement types (CEM II 32.5R and CEM I 42.5R), doses (0, 2%, 4% and 6%) as well as replacement rates in this research study. The compressive and density of concrete were used in the testing. At the end of the 28-day period, destructive and nondestructive tests were performed on cube specimens of 150 mm150 mm150 mm. The concrete density is not decreased with the addition of more perlite (from 45 to 60 percent), since the enlarged perlite has a very low barrier to crushing. To get a homogenous and fluid concrete mix, longer mixing times for all the mix components are necessary due to the higher amount of perlite. As a result, it is not suggested to use greater volumes of this aggregate in RPC. In the presence of de-icing salt, the lightweight RPC exhibits excellent freeze-thaw resistance (mass is less than 0.2 kg/m²). The addition of perlite strengthens the aggregate-matrix contact, but there is no apparent ITZ. An increased compressive strength was seen in concretes containing expanded perlite powder and steel fibers with good performance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.817-818
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• 2012

본 연구에서는 치과에서 마취 시 환자들의 고통을 최소화 하기위하여 무통마취를 위한 치과용 약물주입기를 구현하였다. 약물의 주입 시 통증을 최소화하기 위해서 온도를 $36{\pm}2^{\circ}C$ 범위로 제어하여 체온과 유사한 온도로 유지하였다. 이를 위하여 필름히터 방식을 이용한 치과범용국소약물(36mg, 2% 리도카인) 앰플 가열부를 설계하였다. 또한 약물이 주입되는 양을 능동적으로 제어하기 위하여 약물주입 환부의 환자별 흡수 속도 차이에 차등 주입을 위한 압력 측정 시스템을 구현하였다. 필름 형태의 압력 센서를 통하여 전달 압력을 측정하였으며 측정된 압력을 바탕으로 능동적으로 모터의 동작을 제어함으로써 약물주입시 환자의 고통을 최소화 할 수 있도록 구현하고자 하였다.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.324-324
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• 2005

• 대한치주과학회:학술대회논문집
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• 2005.11a
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• pp.172-173
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• 2005

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.156-157
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• 2018

의료분야에서 원격판독은 보편화되어 있다. 하지만 이러한 원격판독에 필요한 전송과 관리 시스템은 부족하다. 본 논문에서는 가정용 카메라 모듈을 구성하고 이를 통해 모바일 애플리케이션으로 영상 스트리밍 및 사진 촬영을 하여 촬영된 사진을 치과로 전송하고 원격으로 검진할 수 있는 카메라 모듈 및 애플리케이션의 영상 전송을 위한 방법론을 제시한다. 안드로이드 애플리케이션과 카메라 모듈의 스트리밍 과정에는 여러 가지 문제가 발생한다. 모듈에서의 촬영 영상과 애플리케이션의 스트리밍 영상 간의 딜레이가 존재하는 것과 스트리밍 도중에 영상이 검은 화면으로 나왔다가 다시 돌아오거나 화절 저하 현상이 일어나는 것이다. 이러한 문제점들을 개선하고 최적화 할 수 있도록 한다.

• Journal of environmental and Sanitary engineering
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• v.21 no.2 s.60
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• pp.1-10
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• 2006

Codonopsis pilosula and Adenophora triphylla were cultivated by sawing seeds, but the germination rate were low. To cultivate these two wild plants was very difficult. The marketable roots of the plants had low quality. The plant pathogens were very difficulty to prevent the diseases (Rhizoctonia, Pythium, Fusarium, Erwinia, Botrytis, Phythophthora) appeared in cultural state. For the extermination of the disease needs a lot of agricultural chemicals, the effect of remain behind an insecticides was high of a hazardous rate after harvest. On this studies, for the safe prevention of the diseases and the promote of seeds germination, we used Bacillus subtilis, B. liquefaciens, Paenibacillus polymixa, Pseudomonas putida separated in our research, these results would bring us harmless products of medicinal herbs for human.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.529-534
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• 2011

The air-motor unit of the hand-piece had not been developed inside of the country yet. Therefore it needs some research works. The objective of this study is to investigate the effect of the many mini holes at the outle of the air-motort. The flow fields analysis has been conducted by the immersed solid method using ANSYS 12.0 CFX.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.201-206
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• 2004

Laser scanner are getting used for inspection and reverse engineering in industry such as motors, electronic products, dies and molds. However, due to the lack of efficient scanning technique, the tasks become limited to the low accuracy purpose. The main reasons for this limitation for usefulness are caused from the optical drawback, such as irregular reflection, scanning direction normal to measuring surface, the influence of surface integrity, and other optical disturbances. To overcome these drawback of laser scanner, this study propose the mechanism to reduce the optical trouble by using the 2 kinds of rotational movement axis and by composing the spherical coordinate to scanning the surface keeping normal direction consistently. So, it could be designed and interfaced the measuring device to realize that mechanism, and then it could acquisite the accurate 3D form cloud data. Also, these data are compared with the standard master ball and the data acquisited from the touch point sensor, to evaluate the accuracy and stability of measurement and to demonstrate the implementation of an dental tooth purpose system

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.123-125
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• 2008

Enamel layer consists of carbonated hydroxyapatite of 85%, water of 12% and protein of 3% and lipid and tentin consists of carbonated hydroxyapatite of 47%, water of 20% and protein of 33% and lipid so if heat is increased in teeth and then teeth color is discolor. In case high temperature is applied in teeth, teeth color changed quality is measured about change of time for minimize teeth change of color. Spectroscopic light intensity special quality by change of time rise at specification temperature.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.225-226
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• 1998

치과용 복합레진으로 사용하기 위해서 새로운 다관능성 메타크릴레이트 유도체를 합성하였으며, 이 유도체와 기존의 Bis-GMA를 혼합하여 새로운 복합레진을 만들었다. 제조된 복합레진의 물리적 물성 및 생체친화성은 기존의 Bis-GMA control보다도 더 우수하였다.