• International Journal of Automotive Technology
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• 제5권3호
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• pp.155-164
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• 2004

The direct injection gasoline spray-wall interaction was characterized inside a heated pressurized chamber using various visualization techniques, including high-speed laser-sheet macroscopic and microscopic movies up to 25,000 frames per second, shadowgraph, and double-spark particle image velocimetry. Two hollow cone high-pressure swirl injectors having different cone angles were used to inject gasoline onto a heated plate at two different impingement angles. Based on the visualization results, the overall transient spray impingement structure, fuel film formation, and preliminary droplet size and velocity were analyzed. The results show that upward spray vortex inside the spray is more obvious at elevated temperature condition, particularly for the wide-cone-angle injector, due to the vaporization of small droplets and decreased air density. Film build-up on the surface is clearly observed at both ambient and elevated temperature, especially for narrow cone spray. Vapor phase appears at both ambient and elevated temperature conditions, particularly in the toroidal vortex and impingement plume. More rapid impingement and faster horizontal spread after impingement are observed for elevated temperature conditions. Droplet rebounding and film break-up are clearly observed. Post-impingement droplets are significantly smaller than pre-impingement droplets with a more horizontal velocity component regardless of the wall temperature and impingement angle condition.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 춘계학술발표회논문집
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• pp.485-490
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• 2004

Recently, distribution transfer velocity was extremely lowered by high supply rate of vehicle and low road rate. Therefore expansions of transfer network these were subway, road and railway to recover competitive power as a reform measure of physical distribution traffic were become preference previous subject. For reason of that, an expansion of transfer network is meeting competitive power as selected an elevated road in the ground road network that condition of location calm and get out of the existing urban than the underground road to connect oversensitive a large city and expanded small and medium satellite town. In the meantime, while elevated structures construct, they go through the civilian residential section, agriculture land, etc. The consequence is that it raises a vibration, noise, dust, an infringement of the right to a view and an infringement of the right to a sunshine. In this study, we analyzed Quantitatively sunshine quantity with building 3D simulation model of civil structure. Therefore, we present as planning data to reduce a civilian appeal for dispute of the right to sunshine and an economic and time loss between the government and construction company In addition to that, for the standard of the standard plan of usable sunshine quantity program in the practical business, the building of convenient user interface will be the project to be done.

• Computers and Concrete
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• 제2권3호
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• pp.189-202
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• 2005

This paper presents an analysis of some experimental results concerning micro-structural tests, permeability measurements and strain-stress tests of four types of High-Performance Concrete, exposed to elevated temperatures (up to $700^{\circ}C$). These experimental results, obtained within the "HITECO" research programme are discussed and interpreted in the context of a recently developed mathematical model of hygro-thermal behaviour and degradation of concrete at high temperature, which is briefly presented in the Part 2 paper (Gawin, et al. 2005). Correlations between concrete permeability and porosity micro-structure, as well as between damage and cracks' volume, are found. An approximate decomposition of the thermally induced material damage into two parts, a chemical one related to cement dehydration process, and a thermal one due to micro-cracks' development caused by thermal strains at micro- and meso-scale, is performed. Constitutive relationships describing influence of temperature and material damage upon its intrinsic permeability at high temperature for 4 types of HPC are deduced. In the Part II of this paper (Gawin, et al. 2005) effect of two different damage-permeability coupling formulations on the results of computer simulations concerning hygro-thermo-mechanical performance of concrete wall during standard fire, is numerically analysed.

• 한국안전학회지
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• 제34권5호
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• pp.1-6
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• 2019

The mobile elevated work platforms(MEWPs) consist of work platform, extending structure, and car, and it is a facility to move persons to working positions. MEWPs are useful but composed complex pieces of equipments, and accidents are caused by equipment defects. Among them, accidents caused by fracture of the bolts fixing the extension structure and the turntable are increasing. In this study, fatigue failure and fatigue life of a turntable fixing bolt subjected to irregular fatigue load were analyzed by FEA. For this purpose, finite element modeling is proposed and structural analysis and fatigue analysis are performed simultaneously for fixing bolts. As a result of the structural analysis, it was confirmed that there is no risk of permanent deformation because the maximum stress acting on the fixing bolt is lower than the yield strength, and fatigue analysis was confirmed that the fatigue life is less than the design standard. The fatigue analysis results of this study can be effectively used for the design and the documentary assessment of the safety certification of the MEWPs by examining the fatigue life of the turntable fixing bolt.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.29-32
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• 2002

This paper describes a novel structure of NMOSFET with elevated SiGe source/drain region and ultra-shallow source/drain extension(SDE)region. A new ultra-shallow junction formation technology. Which is based on damage-free process for rcplacing of low energy ion implantation, is realized using ultra-high vacuum chemical vapor deposition(UHVCVD) and excimer laser annealing(ELA).

• 한국지역지리학회지
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• 제16권6호
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• pp.623-634
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• 2010

제주도 서부지역에서 밀집하여 나타나는 고가수조는 제주도 농업경관의 큰 특징을 이루고 있다. 본 연구에서는 제주도 서부지역에서 고가수조가 밀집하여 나타나는 원인에 대하여 살펴보았다. 그 결과 고가수조의 밀집은 기후, 수리지질구조, 토양, 지형, 토지이용의 복합적인 영향을 받아 형성된 것임을 알 수 있었다. 특히 제주도의 고가수조는 배수가 양호한 토양, 수리지질 특성으로 인해서 스프링클러를 이용해 지속적으로 물을 공급해야만 하는 재배방식과 연관이 깊다. 본 연구 결과는 제주도 농경지대의 밀집 고가수조 경관이 제주도의 자연환경 아래에서 농부들이 적응하는 과정에서 형성된 독특한 농업경관임을 보여준다.

• 한국전자파학회논문지
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• 제14권3호
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• pp.283-289
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• 2003

본 논문에서는 DSL(Descended Signal Line)을 이용한 새로운 다층의 PBG 구조를 제안하였다. 측정 결과로부터 DSL을 이용한 제안된 PBG 구조는 일반적인 다층의 DGS 구조에 비하여 크기면에서 72 % 감소하였고 대역폭에서 13 % 증가하였다. 또한 EGP(Elevated Ground Plane)를 이용한 PBG 구조와 비교하면 제안된 구조는 크기가 42 % 감소하였고 대역폭이 23 % 증가하였다. 그리고 조작된 6 개의 PBG 구조들을 측정한 결과, 모든 패턴들이 동일한 차단주파수와 함께 저지대역 특성을 지님을 확인하였다. 따라서 본 논문에서 제안된 구조는 삽입손실이 20 ㏈인 20 ㎓에서 모든 패턴이 300 MHz 이하의 매우 정확한 오차(tolerance)를 가짐으로써 소형의 마이크로파 집적 회의나 모듈 개발에 효과적으로 활용될 수 있으리라 기대된다.

• 한국결정학회:학술대회논문집
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• 한국결정학회 2002년도 정기총회 및 추계학술연구발표회
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• pp.24-24
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• 2002

HtrA (high temperature requirement A), a periplasmic heat shock protein, is known to have molecular chaperone function at low temperatures and proteolytic activity at elevated temperatures. To investigate the mechanism of functional switch to pretense, we have determined the crystal structure of the N-terminal protease domain (PD) of HtrA from Thermotoga maritima. HtrA PD shares the same fold with chymotrypsin-like serine professes. However, crystal structure suggests that HtrA PD is not an active pretense at current state since its active site is not formed properly and blocked by an additional helical lid. On the surface of the lid, HtrA PD has hydrophobic patches that could be potential substrate binding sites for molecular chaperone activity. Present structure suggests that the activation of the proteolytic function of HtrA PD at elevated temperatures might occur by the conformational change.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.238.2-238.2
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• 2011

Organic thin film transistors (OTFTs) have been attracting considerable attention because of their potential use in low-cost, large area, electronic devices such as flexible displays, biochemical sensors, and smart cards. In past several years, gold/pentacene has been frequently used in OTFTs because of the high mobility of pentacene and the high work function of gold. To improve the performance of the OTFTs contact area doping of pentacene with p-doping materials are well known. In this work we demonstrated selectively contact area doping of pentacene with Iodine vapor. For effective doping elevated pentacene layer under the source-drain area was deposited and exposed to Iodine vapor. We got better electrical performance for elevated pentacene structure rather than planer structure with relatively high field-effect mobility.

• Journal of Ecology and Environment
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• 제33권3호
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• pp.261-270
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• 2010

Increasing atmospheric $CO_2$ affects the soil carbon cycle by influencing microbial activity and the carbon pool. In this study, the effects of elevated $CO_2$ on extracellular enzyme activities (EEA; ${\beta}$-glucosidase, N-acetylglucosaminidase, aminopeptidase) in salt marsh sediment vegetated with Suaeda japonica were assessed under ambient atmospheric $CO_2$ concentration (380 ppm) or elevated $CO_2$ concentration (760 ppm) conditions. Additionally, the community structure of sulfate-reducing bacteria (SRB) was analyzed via terminal restriction fragments length polymorphism (T-RFLP). Sediment with S. japonica samples were collected from the Hwangsando intertidal flat in May 2005, and placed in small pots (diameter 6 cm, height 10 cm). The pots were incubated for 60 days in a growth chamber under two different $CO_2$ concentration conditions. Sediment samples for all measurements were subdivided into two parts: surface (0-2 cm) and rhizome (4-6 cm) soils. No significant differences were detected in EEA with different $CO_2$ treatments in the surface and rhizome soils. However, the ratio of ${\beta}$-glucosidase activity to N-acetylglucosaminidase activity in rhizome soil was significantly lower (P < 0.01) at 760 ppm $CO_2$ than at 380 ppm $CO_2$, thereby suggesting that the contribution of fungi to the decomposition of soil organic matter might in some cases prove larger than that of bacteria. Community structures of SRB were separated according to different $CO_2$ treatments, suggesting that elevated $CO_2$ may affect the carbon and sulfur cycle in salt marshes.