• 제목/요약/키워드: 구조재

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Catalytic CVD-Kinetics of Pyrolytic Carbon and SiC on the Stainless Steel Stent (Stainless Steel Stent에 Pyrolytic Carbon과 SiC의 촉매적 CVD-Kinetic연구)

  • 이보성;이무용
    • Proceedings of the KAIS Fall Conference
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    • 한국산학기술학회 2000년도 추계학술대회
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    • pp.30-33
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    • 2000
  • 최근 국내에서도 관 동맥 질환 환자의 수가 급증하고 있으며, 관 동맥 질환의 치료 방법인 관 동맥 성형 술은 관 동맥 stent의 도입에 의하여 보편화되어 국내에서 년간 5000개 이상의 stent가 시술되고 있다. 그러나 stent는 고가(1,200천원/개)로 전량 수입에 의존하고 있으며, 시술 후 사망까지 이를 수 있는 혈전에 의한 급성 페쇠와 재 협착이 문제점이다. 이를 위한 한가지 방법이 생체 적합성이 뛰어난 복합 stent의 개발인데 SiC나 Carbon을 coating한 stent는 시술 후 혈전 형성을 억제하는 것으로 알려져 있다. 특히 가장 순수한 Pyrolytic carbon은 hemocompatibility가 탁월하고 기밀 성이기 때문에 본 연구에서 그의 CVB-Kinetics를 연구코저 하는 것이다. methane으로부터 pyrolytic carbon의 CVD는 온도에 따라서 다양한 구조를 가지며 따라서 그의 mechanism도 다양하다는 것은 잘 알려져 있다. 더구나 광간(균질)반응과 표면(불균질)반응의 정량적 관계에 따라서도 다르다는 것도 확인되었다. 그러나 stainless steel 316L로 만든 stent는 12 - 15 %의 Ni과 2%의 Mo을 함유해서 금속성을 잃지 않는 저온(600℃)에서도 pyrolytic carbon의 속매적 CVD가 가능함을 그리고 SiC의 코팅에 적합한 buffer layer 역할을 함을 확인하였다. 그리하여 본 연구는 반응기 설계에 필요한 저온 촉매적 pyrolytic carbon의 CVD-kinetics의 연구결로 그의 mechanism과 함께 rate law 식을 유도, 확인하였으며 600℃, 90kPa에서 P/sub ch4//P/sub H2/=5:1과 체류시간 1.8 sec가 최적임을 발견하였다. 이때 석출속도 11.2 g-mol/g-cat.h 혹은 두께속도로 73 nm/sec를 나타내었다.메타놀-물 (1 : 1) 유출액에서 $(0.80\;{\mu}g)$ 검출되었다. 하면 morey eel내장에서 얻은 독물질도 DEAE-셀루로즈에서 ST-1 과 ST-2로 나누어지며, 이 ST-1의 TLC, HPLC 및 알루미나 컬럼상의 거동이 파랑비늘돔에서 얻은 ST-1의 그것과 같으므로 scaritoxin으로 보고한 ST-1은 ciguatoxin의 형태인 less polar cigutoxin (LPCTX) 으로 생각된다.에서 각각 대조구의 57, 413 및 315% 증진되었다. 거품의 열안정성은 15분 whipping시, pH 4.0(대조구, 30.2%) 및 5.0(대조구, 23.7%)에서 각각 $0{\sim}38.0$$0{\sim}57.0%$이었고 pH 7.0(대조구, 39.6%) 및 8.0(대조구, 43.6%)에서 각각 $0{\sim}59.4$$36.6{\sim}58.4%$이었으며 sodium alginate 첨가시가 가장 양호하였다. 전체적으로 보아 거품안정성이 높은 것은 열안정성도 높은 경향이며, 표면장력이 낮으면 거품형성능이 높아지고, 비점도가 높으면 거품안정성 및 열안정성이 높아지는 경향이 있었다.protocol.eractions between application agents that are developed using different languages. Dynamic agent invocation is accomplished by Java Native Interface(JNI) that links two heterogeneous methods, and by KQML language interface that facilitates the communications between heterogeneous agents. This scheme of dyna

An Analysis of the Economic Effects for the Immersive Media Industry (실감미디어 산업의 경제적 파급효과 분석)

  • Lee, Kyoung-Jae;Jeong, Woo-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • 제36권7B호
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    • pp.795-805
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    • 2011
  • The research on the immersive media technology is actively being done with the emergence of immersive services using immersive media, especially in the broadcasting industry and with the increased market demand for it. The industry which produces, transmits, processes and services the immersive contents is commonly called Immersive Media Industry. Immersive Media Industry has recently received attention as next-generation strategic industry with its high marketability and its high possibility of market expansion through convergence with other industry such as education, health, advertisement, travel and public service industry. As other advanccd country such as the U.S., Japan and Europe buckle down to take the innitiative in the immersive media industry, Korea government also begins to make plan to promote the immersive media industry. As above, immersive media industry is a cutting-edge convergence industry which embraces broadcasting, telecommunication and contents industry and it is rising as core growth engine industry. This article analyses the economic effects of immersive media industry through quantatitive method and evaluates the relations between the immersive media industry and the other related industries. As a result, the effect on production inducement of immersive media industry is 610.9 billion Korean Won; the effect on value-added inducement is 468.7 billion Korean Won; and it is measured that 3,258 job will be created by the immersive media industry.

A Cell-based Indexing for Managing Current Location Information of Moving Objects (이동객체의 현재 위치정보 관리를 위한 셀 기반 색인 기법)

  • Lee, Eung-Jae;Lee, Yang-Koo;Ryu, Keun-Ho
    • The KIPS Transactions:PartD
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    • 제11D권6호
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    • pp.1221-1230
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    • 2004
  • In mobile environments, the locations of moving objects such as vehicles, airplanes and users of wireless devices continuously change over time. For efficiently processing moving object information, the database system should be able to deal with large volume of data, and manage indexing efficiently. However, previous research on indexing method mainly focused on query performance, and did not pay attention to update operation for moving objects. In this paper, we propose a novel moving object indexing method, named ACAR-Tree. For processing efficiently frequently updating of moving object location information as well as query performance, the proposed method is based on fixed grid structure with auxiliary R-Tree. This hybrid structure is able to overcome the poor update performance of R-Tree which is caused by reorganizing of R-Tree. Also, the proposed method is able to efficiently deal with skewed-. or gaussian distribution of data using auxiliary R-Tree. The experimental results using various data size and distribution of data show that the proposed method has reduced the size of index and improve the update and query performance compared with R-Tree indexing method.

A Study on Survivability of Node using Response Mechanism in Active Network Environment (액티브 네트워크 환경에서 대응 메커니즘을 이용한 노드 생존성에 관한 연구)

  • Yang, Jin-Seok;Lee, Ho-Jae;Chang, Beom-Hwan;Kim, Hyoun-Ku;Han, Young-Ju;Chung, Tai-Myoung
    • The KIPS Transactions:PartC
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    • 제10C권6호
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    • pp.799-808
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    • 2003
  • Existing security solutions such as Firewell and IDS (Intrusion Detection System) have a trouble in getting accurate detection rate about new attack and can not block interior attack. That is, existing securuty solutions have various shortcomings. Shortcomings of these security solutions can be supplemented with mechanism which guarantees an availability of systems. The mechanism which guarantees the survivability of node is various, we approachintrusion telerance using real time response mechanism. The monitoring code monitors related resources of system for survivability of vulnerable systm continuously. When realted resources exceed threshold, monitoring and response code is deployed to run. These mechanism guarantees the availability of system. We propose control mathod about resource monitoring. The monitoring code operates with this method. The response code may be resident in active node for availability or execute a job when a request is occurred. We suggest the node survivability mechanism that integrates the intrusion tolerance mechanism that complements the problems of existing security solutions. The mechanism takes asvantage of the automated service distribution supported by Active Network infrastructure instead of passive solutions. The mechanism takes advantage of the automated service distribution supported by Active Network infrastructure instead of passive system reconfiguration and patch.

The Localization of Lectin Receptors in the Tissue of the Paragonimus westermani (폐흡충조직내 Lectin(WGA) 수용체의 분포)

  • Kim, Soo-Jin;Nahm, Heun-Woo;Lee, Joon-Sang;Joo, Kyung-Whan
    • Applied Microscopy
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    • 제30권1호
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    • pp.101-111
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    • 2000
  • In this study, the distribution of lectin receptors in Paragonimus westermani tissue was explored using colloidal gold label complexed with lectin WGA purified from wheat germ (Triticum vulgare). The lectin WGA gold complex, shown to recognize GlcNAc (N-acetylgalactosamine) and NeuNAc (N-acetylneuraminic acid) regions, was applied to detect binding sites in Lowicryl HM 20 sections viewed under electron microscope. Labeled sections of the metacercaria revealed gold particles specifically distributed on the tegumental syncytium and lamella of the excretory canal. Labeling of young adult tissue was then quantified and compared to that of adult worm tissue. Adult worm tissue sections resulted in specific gold particle distribution on the lamella of caecal epithelium and excretory canal. These results indicate that lectin WGA receptors are located in the tegumental syncytium and lamella of the excretory canal of the metacercariae, and in the lamella of the caecum and excretory canal of the young adult and adult. Therefore, the GlcNAc and NeuNAc regions in the tegumental syncytium appear to be functionally associated with cell-recognition and protection from the immune system of the host, and linked with membrane transport and absorption of nutrients in the lamella of the excretaory canal and caecal epithelia.

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A Study on the Construction Method of the Songsanri Tombs Using Geophysical Exploration Method (송산리 고분군의 지구물리학적 조사를 통한 고분축조방법 고찰)

  • Suh, Mancheol;Lee, Changwhan;Jeong, Gyeok;Kim, Donghyun
    • Journal of Conservation Science
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    • 제6권1호
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    • pp.61-70
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    • 1997
  • An integrated geophysical survey was conducted to study a construction method of the Sonsanri tombs including the Muryong royal tomb. With the distribution of soil resistivity and self potential values, the boundary between original ground and the construction site was delineated clearly. The original ground has relatively high resistivity of $1,000\~1,500$ ohm-m and low self-potential values of $0{\pm}3mV/m$, while the construction site has low resistivity less than 200 ohm-m and quite high self-potential values of $-20\~30mV/m$. It is interpreted that the open site for construction of subsurface tomb has the size of about 35 m in the north-south direction. Big difference in characteristics of ground between the tomb site and the original site gives a clue for the construction method of tombs in Baekje dynasty. The site was opened about 35 meters in the north-south direction and then a mold structure was constructed with a brick frame outside. The brick frame consists of bricks cemented each other and structually combined. The mold structure was removed from inside after refill of the opened construction site with some cemented rock debris and soil.

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Study on the Conservation of Scale Armor Using Duplication Technique - Focused on the Case of the Conservation Treatment of the Excavated Artifact from Jinyoung 2-Area, Gimhae - (복제 기법을 이용한 찰갑의 보존처리 - 김해 진영 2지구 출토품의 보존처리 사례를 중심으로 -)

  • Kim, Dong Min;Park, Jung Hyeok;Cho, Hyun Kyung;Cho, Nam Chul
    • Journal of Conservation Science
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    • 제31권1호
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    • pp.75-86
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    • 2015
  • A scale Armor is usually excavated in a scattered form weakened by corrosion after its burial. Therefore, they should be brought into the indoor in a safe environment for the on-site conservation treatment as it was excavated. They should be placed on a stable support with a reinforced base in the indoor treatment. In this process, the bottom surface which can not be observed after the conservation treatment is placed for a record by actual survey and photography. But this method had a limit on figuring out the whole aspects of the artifact. For compensating the defect, duplication of the artifact was considered as an alternative method for the previous two methods in the case of conservation of the scale Armor from Jinyoung 2-Area, Gimhae. Neck guard was excavated in a distorted form by the earth pressure, and was hard to recognize the original shape. However, whole real material of its original form was secured through the combination of each duplicated lamellae. Throughout the application of the duplication technique in the process of conservation of scale Armor and neck guard, it could secure the real material of the bottom surface and elevate the understanding of the artifact. Moreover, a constitution of the armor could be identified more effectively.

Quantitative Deterioration Assessment and Microclimatic Analysis of the Gyeongju Seokbinggo (Ice-storing Stone Warehouse), Korea (경주석빙고의 정량적 훼손도 평가와 미기후환경 분석)

  • Kim, Ji-Young;Lee, Chan-Hee;Lee, Myeong-Seong
    • Journal of Conservation Science
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    • 제25권1호
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    • pp.25-38
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    • 2009
  • The Gyeongju Seokbinggo (Treasure No. 66) is an ice-storing stone warehouse, consisting mainly of alkaligranite which shows milky white color and medium-grained textures with drusy cavities. As results of deterioration assessment, the deterioration rates were determined as crack (12.5%), disjoining (6.7%), breaking-out (25.1%), exfoliation (20.9%), efflorescence (6.5%), brown discoloration (9.8%), darkgray discoloration (2.0%) and biological discoloration (36.5%). Comprehensive physical deterioration rate and discoloration rate were calculated as 43.7% and 68.7%, respectively, that indicates the Seokbinggo has been severely weathered. Indoor relative humidity was above 90% except in winter season. Indoor microclimate was hardly fluctuating although indoor microclimate was dependent on the outdoor climate. The main cause of deterioration was high relative humidity and a long time of wetness due to penetration of rain, underground water and condensation. It was identified that the water brought out biological discoloration, dissolution of minerals, structural movement and efflorescence, and the dust from the ground soil in front of the entrance accelerated brown and dark gray discoloration on the stone surface.

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A Study on the Development of Poly-Urea for Porcelain Restoration (폴리우레아 도자기 복원 재료의 적용)

  • Han, Won-Sik;Wi, Koang-Chul;Oh, Seung-Jun;Lee, Young-Hoon
    • Journal of Conservation Science
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    • 제34권1호
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    • pp.23-29
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    • 2018
  • This study synthesized poly-urea and used it as a filler material for the restoration of porcelain. The synthesized poly-urea was manufactured as a resin and hardener mix that does not undergo contraction during curing, and is unfading. Given an adhesion strength of $180kg/cm^2$ and shearing strength of $200kg/cm^2$, the synthesized poly-urea exhibited the same efficacy as the epoxy putty currently sold in the market. Moreover, it also overcame the drawback of foaming encountered by urethane restoratives, which are a structurally similar type. The hardening time and pot life could also be controlled using additives. The poly-urea used for the restoration of modern artifacts presented a pot life of approximately one hour and took 12 h for complete hardening ($T_{90}$). When a $2{\times}2{\times}2cm$-sized test sample was added to xylene, poly-urea started to separate approximately two hours later and completed perfect pulverization within the solution 24 h later, demonstrating its reversibility. When directly applied to contemporary artifacts, it demonstrated the potential for restoration, as well as convenience and colorfulness.

Analysis of Greenhouse Gas Emission Models and Evaluation of Their Application on Agricultural Lands in Korea (토양 온실가스 배출 예측 모델 분석 및 국내 농경지 적용성 평가)

  • Hwang, Wonjae;Park, Minseok;Kim, Yong-Seong;Cho, Kijong;Lee, Woo-Kyun;Hyun, Seunghun
    • Ecology and Resilient Infrastructure
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    • 제2권2호
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    • pp.185-190
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    • 2015
  • Greenhouse gas (GHG) emission from agricultural lands is recognized as one of important factors of global warming. The objective of this short communication was to evaluate the applicability of different soil GHG emission prediction models on agricultural systems in Korea. Four models, namely, DNDC, DAYCENT, EXPERT-N and COUP, were selected and the basic structure (e.g., components and sub-model), input variables, and output variables were compared. In particular, the availability and compilation of essential input variables were assessed. Major input variables needed for operating these predictive models were found to be available through database systems established by national organizations such as the Korea Meteorological Administration, the Korean Soil Information System, and the Rural Development Administration. However, in order to apply these models in Korea, it was necessary to calibrate and validate each of the models for the domestic landscape settings and climate conditions. In addition, field data of long-term monitoring of GHG emission from agricultural lands are limited and therefore should be measured.