• Title/Summary/Keyword: composit

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A Forensic Engineering Study on Bursting Accident of Composite Pressure Vessel in CNG Bus (CNG버스 복합재 압력용기 파열사고에 관한 법공학적 연구)

  • Kim, Eui-Soo;Kim, Jin-Pyo;Park, Nam-Kyu;Kim, Youn-Hoi
    • Journal of the Korean Society of Safety
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    • v.23 no.5
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    • pp.15-21
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    • 2008
  • The bus using compressed natural gas(CNG) trend to be extended in use internationally as optimal counter-plan for reducing discharge gas of light oil due to high concern about environment. But, Composit pressure vessels(CPV) to be equipped with CNG bus is always involved in the point that safety accidents happen due to having compressed natural gas. In this report, we analysis the cause of CPV bursting accident by reviewing design and manufacture factor and suggest preventive measure through this case.

Chemical characterization of the fast-growing industrial hemp (Cannabis sativa) woody core and bast fiber (산업용 대마의 목부와 인피섬유의 화학 조성 분석)

  • Shin, Soo-Jeong;Koo, Bon-Wook;Lee, Jae-Won;Choi, In-Gyu
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.482-484
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    • 2006
  • 대마에 대한 분석 결과, 인피 섬유의 경우 리그닌 함량은 7.6%로 다른 목질계 바이오매스나 일년생 초본류와 비교하여 매우 낮은 리그닌 함량을 나타냈으며 탄수화물 함량은 65.4%로 목질계 바이오매스와 유사하고, 초본류보다는 오히려 높았다. 목부는 리그닌 및 탄수화물 함량이 활엽수와 유사한 경향을 나타내었는데 특히 높은 자일란의 함량이 확인되었다. 또한 회분 함량이 인피섬유와 목부에서 각각 5.0%와 2.3%로 낮은 값을 나타내어 당화 및 발효 공정에 적용될 때 회분에 의한 공정 장애(스케일링 등)의 가능성을 낮추어 줄 것으로 사료되었다. 최종적으로 이러한 화학적 분석을 통해 대체에너지 생산을 위한 자원으로서 대마의 가능성을 확인할 수 있었다.

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Efficient Optimal Normal Basis Multipliers Over Composite Fields (합성체상의 효율적인 최적정규기저 곱셈기)

  • Kwon, Yun Ki;Kwon, Soonhak;Kim, Chang Hoon;Kim, Hiecheol
    • Proceedings of the Korea Information Processing Society Conference
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    • 2009.04a
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    • pp.1515-1518
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    • 2009
  • 최적정규기저(Optimal Normal Basis)를 이용한 $GF(2^m)$상의 곱셈은 ECC(Elliptic Curve Cryptosystems: 타원곡선 암호시스템) 및 유한체 산술 연산의 하드웨어 구현에 적합하다는 것은 잘 알려져 있다. 본 논문에서는 최적정규기저의 하드웨어적 장점을 이용하여 합성체(Composit Field)상의 곱셈기를 제안하며, 기존에 제안된 합성체상의 곱셈기와 비교 및 분석한다. 제안된 곱셈기는 최적정규기저 타입 I, II의 대칭성과 가수의 중복성을 이용한 열벡터의 재배열에 따른 XOR 연산의 재사용으로 낮은 하드웨어 복잡도와 작은 지연시간을 가진다.

Centrifuge Model Test on the Bearing Capacity and Failure Mechanism of Composit Ground Improved with Slag Compaction Piles (슬래그 다짐말뚝으로 개량된 복합지반의 지지력 및 파괴메카니즘에 관한 원심모형실험)

  • Yoo Nam-Jae;Park Byung-Soo;Jeong Gil-Soo;Koh Kyung-Hwan;Kim Ji-Sung
    • Journal of the Korean Geotechnical Society
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    • v.21 no.1
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    • pp.59-67
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    • 2005
  • This paper presents experimental and numerical research results of centrifuge model tests performed to investigate the geotechnical engineering behavior of slag compaction pile as a substitute of sand compaction pile. For centrifuge model tests, bearing capacity of composit soil improved with slag compaction piles, stress concentrations in-between pile and soft clay, settlement characteristics, and failure modes were investigated with slags differing in their relative density. A slag was found to be a good substitute for a sand since the slag compaction pile model showed a greater yield stress intensity up to $30\%$ than the sand compaction pile model under the identical testing conditions. Stress concentration ratio tended to increase with the relative density of slag pile and the clear shear lines in the piles were observed at the depth of $2D{\sim}2.5D$ (D=dia. of model pile) from the top of the piles after loading tests. Numerical analysis with a software of CRISP, implemented with the modified Cam-clay model, was carried out to simulate the results of centrifuge model test. Test results about characteristics of load-settlement curves and stress concentration ratio are in relatively good agreements with numerical estimations.

Pipelining Semantically-operated Services Using Ontology-based User Constraints (온톨로지 기반 사용자 제시 조건을 이용한 시맨틱 서비스 조합)

  • Jung, Han-Min;Lee, Mi-Kyoung;You, Beom-Jong
    • The Journal of the Korea Contents Association
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    • v.9 no.10
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    • pp.32-39
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    • 2009
  • Semantically-operated services, which is different from Web services or semantic Web services with semantic markup, can be defined as the services providing search function or reasoning function using ontologies. It performs a pre-defined task by exploiting URI, ontology classes, and ontology properties. This study introduces a method for pipelining semantically-operated services based on a semantic broker which refers to ontologies and service description stored in a service manager and invokes by user constraints. The constraints consist of input instances, an output class, a visualization type, service names, and properties. This method provides automatically-generated service pipelines including composit services and a simple workflow to the user. The pipelines provided by the semantic broker can be executed in a fully-automatic manner to find a set of meaningful semantic pipelines. After all, this study would epochally contribute to develop a portal service by ways of supporting human service planners who want to find specific composit services pipelined from distributed semantically-operated services.

A Trend of Back Ground Surface Settlement of Braced Wall Depending on the Joint Dips in Rocks under the Soil Strata (복합지반 굴착 시 암반층 절리경사 각도별 흙막이 벽체 배후 지표침하의 경향)

  • Bae, Sang-Su;Lee, Sang-Duk
    • Journal of the Korean Geotechnical Society
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    • v.32 no.11
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    • pp.83-96
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    • 2016
  • The surface settlement of the back ground of a braced wall due to the ground excavation has the great influence on the safety of the surrounding area. But it is not easy to predict the settlement of the surrounding area due to proud excavation. Estimation of the settlement of the surface ground induced by the deformation of the braced wall is performed by FEM and empirical method (Peck, Clough etc). In this research, surface settlement of the back ground braced wall depending on the joint dips in rocks during excavating the composit ground was measured at the large scale model test (standard: $0.3m{\times}0.3m{\times}0.5m$). The scale of model test was 1/14.5 and the ground was excavated in ten steps. Earth pressure on the braced wall and ground surface settlement on the back ground of a braced wall were investigated. The surface settlement during the excavation depended on the joint dips in rocks on of the ratio of rock layer. Maximum earth pressure and maximum surface settlement were masured at the same excavation step. In accordance with the increase of the rock layer dips and rock layer ratio, the ground surface settlement increased. The maximum ground surface settlement was 17 times larger at 60 degree joint dips in rocks than that of the horizontal ground conditions. And the position of the maximum surface settlement by empirical method was calculated at the point, which was 17%~33% of excavation depth. In accordance with the increase of the rock layer dips and rock layer ratio, the ground maximum surface settlement increased. The ground surface settlement of composite ground is smaller than that of the empirical.

Microstructures and Mechanical Properties of Al-Ni Eutectic Composite by Upward Continuous Casting (상향식 연속주조법으로 제조한 Ai-Ni 공정복합재료의 응고조직 및 기계적 성질)

  • Kwon, Kee-Kyun;Hong, Chun-Pyo;Lee, Kye-Wan
    • Journal of Korea Foundry Society
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    • v.10 no.1
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    • pp.50-56
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    • 1990
  • Continuous casting of the $Al-Al_3Ni$: eutectic composite was carried out by the upward continuous casting process. The morphology of the eutectic growth and the stability of solid-liquid interface were investigated under various growth conditions in an upward continuous casting. The effect of growth conditions on the mechanical properties of the $Al-Al_3$ Ni eutectic composit was also investigated, and the results were compared with those by the Bridgman method. As for the results, it was possible to get the planar solid-liquid interface at the condition of $G_L/R$$1.04{\times}10^3^{\circ}Csec/mm^2$. And the inter-rod spacing of $Al-Al_3Ni$ eutectic composite was decreased with the increase of pulling speed. The reduction of inter-rod spacing & value of $G_L/R$ caused the increase of ultimate tensile strength in $Al-Al_3Ni$: eutectic composite. The ultimate tensile strengths of $Al-Al_3Ni$ by the upward continuous casting were higher then those by the Bridgman method.

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A Study on Characteristic of the Chosun Government-general Buildings (조선총독부 청사 실내공간의 표현 특성에 관한 연구)

  • Lee, Keun-Hye;Oh, In-Wook
    • Korean Institute of Interior Design Journal
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    • v.16 no.1 s.60
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    • pp.11-20
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    • 2007
  • Modern architecture does a role in terms of connecting traditional and current architecture. In the same time, Which is important part of korean architecture history because of introduction of western architecture. Accordingly, At this meaninglessly going out and leaving of modern architecture, the purpose of this study is systematic researching of 'Cho-sun government-general' interior which is disappeared. I progressed this study to research into the period context at construction of Cho-sun government-general md tendency of architecture and interior at that time. And then understand interior space organization of it. Cho-sun government-general adopted Neo-Baroque style from tendency of that time. Also, showed composite order which is mixed in the Greek temple, the Renaissance and the classic style representing the power. This characteristic is different from current composit order, which is comprehended by our. In order to understand aesthetic value of current straight interior space, It have to be interacted the present and past. But It's averted because it was made in the period of Japanese imperialism. Therefore, We should explore history of interior design that is endowed with sociality and historicity between modern and future interior space as well as current.

A Study on the Dielectric Properties and Mechanical characteristics of Composit Materials due to the High-Temper, and-Humidity (고온.다습하(高溫.多濕下)에서의 복합재료(複合材料)의 수요특성(特性) 및 기계적특성(機械的特性)에 관한 연구(硏究))

  • Lee, Jong-Ho;Lee, Kyu-Chul;Hwang, Yeong-Han;Kim, Hea-Dae;Lee, Tae-Sik;Park, Hong-Tae
    • Proceedings of the KIEE Conference
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    • 1992.07b
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    • pp.750-752
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    • 1992
  • The paper presents the effects of environment on glass-cloth/epoxy composites exposed to humid air were investigated. Tests were performed at temperature 40$^{\circ}C$ and 70$^{\circ}C$ with the materials exposed to humid air at 76% and 90% relative humidity. This investigation surveyed include (a) the moisture absorption and desorption characteristics of single and multi layered composites exposed to steady and to transient ambients, and (b) the resulting changes in tensile strength, dielectric strength, tan $\delta$ and $\varepsilon_{\tau}$ and the effects of environment on these parameters were assessed.

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A Study on Characteristic of the Modern Government Office (근대 공공청사 실내공간의 표현성에 관한 연구)

  • Lee, Keun-Hye;Oh, In-Wook
    • Proceedings of the Korean Institute of Interior Design Conference
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    • 2007.05a
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    • pp.264-269
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    • 2007
  • Modern architecture does a role in terms of connecting traditional and current architecture. In the same time, Which is important part of korean architecture history because of introduction of western architecture. Accordingly, At this meaninglessly going out and leaving of modern architecture, the purpose of this study is systematic researching of the modern Government Office interior. I progressed this study to research into the period context at construction of the modern Government Office and tendency of architecture and interior at that time. And then understand interior space organization of it. The early modern Government Office adopted Neo-Baroque style from tendency of that time. Also, showed composite order which is mixed in the Greek temple, the Renaissance and the classic style representing the power. But, after late 1920 It adopted Modern Style. This characteristic is different from current composit order, which is comprehended by our. In order to understand aesthetic value of current straight interior space, It have to be interacted the present and past. But It's averted because it was made in the period of Japanese imperialism. Therefore, We should explore history of interior design that is endowed with sociality and historicity between modern and future interior space as well as current.

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