• Title/Summary/Keyword: 소구경

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An Assessment for Anti-piercing Designs of RC Slabs against Small Caliber Bullets (소구경 탄자에 대한 철근콘크리트 슬래브의 관입저항력 평가)

  • Kim, Suk-Bong;Kang, Young-Chul;Lee, Jong-Chan;Baek, Sang-Ho;Park, Young-Jun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.10 no.2
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    • pp.69-75
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    • 2007
  • So far, anti-piercing depths for concrete slabs have been determined using Conventional Weapon's Effects Program(CONWEP) that was developed by the U. S. Army's Corps of Engineering. However, it has been suggested by a number of field officers that the values computed by CONWEP tend to be too high for protective facilities used in small military units and that indiscriminate application of these values to such facilities would lead to uneconomical penetration-proof designs. In this study, gunshots onto RC slabs were carried out using KM80 bullets in order to measure the piercing depths. The observed depths and the depths offered by the CONWEP system differed greatly from each other by up to 119 centimeters. Based on the depth values obtained through this experiment, we have proposed a new equation to calculate effective anti-piercing depths for RC slabs against small caliber bullets.

Experimental Study of Error Canceling on the Piercing Depth of Concrete by Single Shot and Barrage of Small Caliber Bullets (소구경 탄자 연발사격 시 콘크리트 관입깊이 오차 상쇄 실험 연구)

  • Lim, Chaeyeon;Kim, Kuk-Joog;Park, Young-Jun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.11a
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    • pp.35-36
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    • 2019
  • Major influence factors for piercing depth of concrete against small caliber bullet are target's property such as compression strength of concrete and bullet's property such as the velocity and weight of it. In particular about the bullet's property, velocity and incidence angle could be controlled by specific position or distance between targets and shooter, but the angle of yaw of bullet dose not. Because the the angle of yaw of bullet causes lower piercing force of bullet, some errors on piercing depth of concrete could be appeared by live fire test for the evaluation of protective performance. Therefore, we have checked the error canceling effect on the piercing depth of concrete by single shot and barrage of small caiber bullets. As a result, we identified that the error of piercing depth by the angle of yaw of bullet could be cancelled by barrage.

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In Vivo Experiment of Tissue-Engineered Artificial Vessel (조직공학적 인조혈관의 생체 내 이식 실험)

  • 임상현;조승우;홍유선;김병수;유경종;장병철;최차용
    • Journal of Chest Surgery
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    • v.37 no.3
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    • pp.220-227
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    • 2004
  • The number of patients with coronary artery disease and peripheral vascular disease are increasing, and the need of small diameter vessel is also increasing. We developed small diameter artificial vessel and experimented in vivo. We got allogenic valve from mongrel dogs, and removed all cells from the allogenic valve. Then, we seeded autologous bone marrow cells onto the decellularized scaffold. After implantation of artificial vessel into the canine carotid artery, we performed angiography regularly. In case of vessel occlusion or at 8 weeks after operation, we euthanized dogs, and retrieved the implanted artificial vessels. Control vessels were all occluded except one (which developed aneurysmal dilatation). But autologous cell seeded vascular graft were patent by 4 weeks in one, by 6 in one and by 8 weeks in two. Histologic examination of patent vessel revealed similar structure to native artery. Tissue-engineered vascular graft manufactured with decellularized allogenic matrix and autologous bone marrow cells showed that tissue engineered graft had similar structure to native artery.

Study on the Property of Guided Wave Signal Analysis according to Defect Shape of Small Size (소구경 튜브 결함 형태에 따른 유도초음파 신호 해석 특성에 관한 연구)

  • Gil, Doo-Song;Ahn, Yeon-Shik;Jung, Gye-Jo;Park, Sang-Gi;Kim, Yong-Gun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.32 no.4
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    • pp.410-417
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    • 2012
  • Currently domestic thermal and nuclear power plants are comprised of many type's condenser and steam generator tubes to produce the electricity of good quality. There are some methods to inspect these tubes in the event that several defects were discovered in these facilities. Among many non-destructive methods, we used guided wave to inspect the soundness of tubes, because this method is very fast to detect the defect and very simple to install the equipment and also, can inspect up to the long range at a fixed point. Also, this method has a drawback that does not detect a very small size defect. So, we made an effort to overcome this drawback through the experimentation and signal analysis according to the size and shape of the defect through the manufacture of various artificial cracks capable to generate within the small size tube in the study and we anticipate that these detect limits can be overcome along with the development of the signal processing and manufacturing technology of the sensor for the inspection.

Properties of the SHOT PATCH Mortar a Wet System for Small Bore Tunnels (소구경 터널에 사용되는 SHOT PATCH용 모르타르의 특성)

  • 정민철;전용희;정종익;박길수
    • Journal of the Korea Concrete Institute
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    • v.11 no.6
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    • pp.121-128
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    • 1999
  • The SHO PATCH System Mortar is a mortar shotcreting system which uses fairly small machine and equipment, and is applied for shotcrete tunnel linings, in particular for small bore tunnels of aqueducts by the TBM(Tunnel Boring Machine) method, and for reparing tunnels suffering from spring water and deterioration. This study shows the characteristics of the new mortar shotcreting system, the SHOT PATCh System Mortar, which exhibits excellent shotcrete performance.

페룰가공용 다이아몬드 드레싱 장치의 특성에 관한 연구

  • 천영재;이은상
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.05a
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    • pp.266-266
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    • 2004
  • 광통신 커넥터 핵심 부품인 페룰(Ferrule)은 광통신의 주요한 커넥터 부품으로 사용되며 슬리브내에서 페룰을 서로 맞대어 광섬유론 정렬하는데 사용이 된다. 광섬유의 맞대기가 정확하고 광학 특성에 영향을 주지 않도록 하기 위해서는 페룰의 외경과 표면의 초정밀 가공이 주요한 품질 특성이 된다. 페룰은 고경도 난삭재의 소구경 세라믹 재질이며 이의 가공을 위해서는 다이아몬드 연삭숫돌을 이용한 무심연삭(centerless grinding) 장치를 사용한다.(중략)

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시추공 시험

  • 황세호;박인식;윤건식;김천수;정상용;배대석;고용권
    • Proceedings of the KSEG Conference
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    • 2004.03a
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    • pp.16001-16125
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    • 2004
  • 물리검층은 주로 석유탐사 분야에서 개발·이용되어왔으나 소구경 시추공을 이용하는 지반조사. 자원평가, 지하수조사 또는 환경오염조사 등에서 물리검층의 수요가 증가하고 있다. 국내에서 수행된 물리검층은 우라늄 탐사 목적으로 1980년 전후로 많이 수행되었으며 1990년 중반에는 지하수 조사에 일부 활용되어 왔다. 현재 물리검층의 활용도가 증가하고 있는 분야는 지반조사 분야로 원위치 물성측정, 시추공과 교차하는 암반의 균열파악 등 터널, 교량과 같은 각종 토목분야의 지반조사에 많이 활용되고 있다. 이외에도 지하수 유동특성 규명이나 환경오염조사, 자원평가(지열, 온천, 석·골재, 금속광상 등)에도 활용되고 있다. (중략)

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Properties of the SHOT Remitar a Wet System for Small Bore Tunnels (소구경 터널에 사용되는 SHOT PATCH용 레미탈의 특성)

  • 정민철;전용희;정종익;박길수
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10b
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    • pp.871-876
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    • 1998
  • The SHOT PATCH System Remitar is a mortar shotcreting system which used fairly small machine and equipment, and is applied for shortcrete tunnel linings, in particular for small bore tunnels of aqueducts by the TBM(Tunnel Boring Machine) method, and for repairing tunnels suffering from spring water and deterioration. This study shows the characteristics of the new mortar shotcreting system, the SHOT PATCH System Remitar, which exhibits excellent shotcrete performance.

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Consumer's Awareness and Preference on Brand Shopping Bag Design's Eco-friendly Resource (세미나 - 브랜드 쇼핑백 디자인의 친환경적 소구에 대한 수용자 인식과 선호도)

  • Yang, Cho-San
    • The monthly packaging world
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    • s.245
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    • pp.98-112
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    • 2013
  • 친환경 디자인이란 환경과 생태적 측면을 고려한 제반 디자인 활동이나 경향을 의미하며, 최근 많은 기업체에서 친환경 제품이나 서비스를 통해 일반 소비자들과 소통하는 중요한 분야로 인식되고 있다. 따라서 본 연구에서는 백화점 쇼핑백 디자인의 재활용 여부와 경험, 횟수, 관심도, 조형성 평가를 통해 주요 3개국(한국, 일본, 미국) 백화점 쇼핑백에 대한 일반소비자들의 친환경적 소구에 대한 인식과 선호도 연구결과를 조사하는데 목적이 있다. 본 연구에서는 분석을 위해 연구범위를 주요 3개국 고급백화점으로 제한하였으며, 분석 대상업체의 개수를 한국 4업체, 일본 4업체, 미국 6업체 등 최종 3개국 14업체를 분석대상으로 선정하고 통계분석(spsswin18.O)하였다. 본 고는 한국브랜드디자인학회 통권 제24호에서 발췌했다.

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Development of Biocompatible Vascular Graft -Endothelialization of Small Vascular Graft- (생체적합성 인조혈관의 개발 -혈관내피화 인조혈관-)

  • 김형묵;이윤신
    • Journal of Chest Surgery
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    • v.29 no.4
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    • pp.373-380
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    • 1996
  • Prevention of thromboembolism is the most important task in the development of bioconpatible small caliber artificial vascular graft. In normal vessels, vascular endothelial cells maintain homeosatsis by secreting numerous factors. The aim of this study is to develope a method which Improves biocompatibility of small caliver polyurethane graft using endothelial cell culture technique, and ev luate the efTectiveness of extracelluar matrix for endothelization which was produced by cultured fibroblast. Methods ; Multiporous polyurethane tube of 3 mm diameter, 0.3 mm thickness was manufactured for vascular graft. Three mongrel dogs were intubated and internal jugular veins removed. Extracelluar matrix produced by cultured flbrobast which was obtained from dog's internal jugular vein were coated to the polyurethane graft. Then, endothelial cells extracted from Jugular vein were cultured and fixed on the extracelluar matrix layer of vascular graft. Endothelial cell coated vascular grafts were implanted to the carotid arteries of experimental dogs as interposed autograft. Implanted grafts were removed after 3 and 6 weeks. As a control, PTFE graft was interposed on carotid artery. These experiments demonstrated that extracelluar matrix produced by fibroblast can afford a base for endothelial cell linings of polyurethane graft. Although thrombosis were developed on autografted en othelial cell coated graft, 33% opening was noticed, and showed less adhesion to adjacent tissue layer. These findings suggest that fiboblast produced extracelluar matrix which can be used for edothelial cell lining vascular graft, and by improving the cultured endothelial cell function, there will be a new modality for reducing thrombosis on small vascular graft.

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