A three-dimensional Computational Fluid Dynamics (CFD) with the renormalization group (RNG) k-ε turbulence model was used to simulate flow patterns and corresponding dispersion of passive H₂S pollutant in urban area with complex terrains. The major emission sources of H₂S considered in this study include the sewage disposal plant and the leather waste water disposal plant located the northwest direction from the residential area. In order to describe the flow and dispersion characteristics of H₂S in the complex terrain, the terrain data in the modeling domain was processed as the input data for the CFD model, while the previous studies were conducted in flat terrains. The recirculating flow zone was formed behind the buildings, and the pollutant concentration in the zone was noticeably high because of limited ventilation. The velocity profile and ventilation rate along the height were calculated to identify the effective zone of weak flow and re-circulation by the buildings and complex terrains. According to this study, the CFD modeling was demonstrated to be highly effective to simulate the effect of buildings and complex terrains on the flow and dispersion of odors. Detailed studies are desirable to further validate the odor dispersion with measurements under more complex flow conditions.

We report on the capacitively coupled O2 plasma etching of PMMA and polycarbonate (PC) with a diffusion pump. Plasma process variables were process pressure and CCP power at 5 sccm O2 gas flow rate. Characterization was done in order to analyze etch rate, etch selectivity, surface roughness, and morphology using stylus surface profilometry and scanning electron microscopy. Self bias decreased with increase of process pressure in the range of 25~180 mTorr. We found an important result for optimum pressure for the highest etch rate of PMMA and PC, which was 60 mTorr. PMMA and PC had etch rates of 0.46 and 0.28 μm/min under pressure conditions, respectively. More specifically, etch rates of the materials increased when the pressure changed from 25 mTorr to 60 mTorr. However, they reduced when the pressure increased further after 60 mTorr. RMS roughnesses of the etched surfaces were in the range of 2.2~2.9 nm. Etch selectivity of PMMA to a photoresist was ~1.5:1 and that of PC was ~0.9:1. Etch rate constant was about 0.04 μm/minW and 0.02 μm/minW for PMMA and PC, respectively, with the CCP power change at 5 sccm O2 and 40 mTorr process pressure. PC had more erosion on the etched sidewall than PMMA did. The OES data showed that the intensity of the oxygen atomic peak (777.196 nm) proportionally increased with the CCP power.

동영상 UCC의 확산으로 인하여 ‘참여’와 ‘공유’의 문화생산 방식이 네티즌을 네트워크 사회의 주체로 부각시키면서 커뮤니케이션 패러다임의 변화가 가속화되고 있다. 본 논문은 동영상 UCC의 확산의 배경이 된 웹2.0 패러다임과 동영상 UCC의 현황(배경, 유형, 이용현황), 동영상 UCC의 사회문화적 영향에 대하여 논의하고, 그 결과를 바탕으로 시민 참여 매체로서의 동영상 UCC의 활성화를 위한 방안을 모색하는데 목적을 둔다. 연구결과 UCC 확산의 사회문화적 영향은 첫째, 개방과 공유를 통한 참여 중심의 프로슈머 사회 실현에 기여, 둘째, UCC의 미디어적 영향력 증가, 셋째, 계층 간의 디지털 정보격차 강화로 요약된다. UCC의 활성화를 위해서는 저작권, 초상권 등에 관한 문제, 소비자의 커뮤니케이션 확장자로의 역할 수행, 수익모델 및 보상 구조 모색, UCC의 배포 및 확산 관련 기술적, 제도적 문제 등이 선결되어야 할 과제이다. UCC의 활성화는 산업논리에 따라 시장에만 맡겨서는 안되며, UCC 문화는 공익적 영역에서도 활성화되어야 한다.

Considering heat insulation and beautiful sight of construction, making use of exterior panels is increasing. Recently the exterior panels now are weak very much, and so in consequence of the weakness fire spreads rapidly. Compared with internal fire, external vertical fire spread rate goes rapidly and it is extensive in spread range, therefore it is dangerous very much. Accordingly, under present condition of poor standard of exterior panels, it is required to take measure to meet the appropriate situation. In this study, by making use of FDS(Fire Dynamic Simulation) program about external vertical fire of high rise building, fire behavior is searched by computer. It is important that realizing by computer fire modeling about external vertical fire must be included certainly in procedure of fire performance design in the future. In modeling program, FDS version 5 is available, and aluminium composite panel is applied in external panels. In this study, for realizing of actual fire condition, FDS is applied by details of fire scenarios considering influence of wind.

Artist-in-residence which gets chances to create by artists’moving and encounteringnew culture is heightening its level in 21th century. Under the circumstance that issue ofcultural diversity and the role of artists which is for city revitalization and sustainability areaffect residency program in the midst of highly proceeded globalization that internationalexchange. Therefore, in the aspect of creative city, a new model is creating by reuse ofabandoned industrial facilities and Asia or Eastern country become the subject in residencyprogram management, the issue of cultural diversity is getting more important, programsbased on project not just residence are managing. Furthermore, it has inter-countrycooperating system in the rage of cultural management. It means that artists’space ofcreating activity has a new, social role in spontaneously we need to approach to followingmodel in Korea, as well.

건물군 내의 난류 유동에 의한 오염물질 확산을 LES 기법을 이용해 해석하였다. 본 연구의 동기는 복잡한 건물 내의 오염물질 확산을 효과적으로 예측하려는 노력에 기인한다. 결과적으로 확보될 예측 기술은 화학적으로 치명적인 재난을 예방하거나 기발생된 사고에 대한 빠른 대처를 가능케 할 것이다. 우선, 채널 내 난류 유동에 의한 농도 확산 및 단일 큐브 주위의 농도확산에 대한 타 연구 결과와의 비교를 통해 본 코드의 검증을 수행하였다. 그 다음에 도심 도로변의 배기가스에 의한 대기 오염을 모사하였다. Lagrangian dynamic subgrid-scale model이 유동장 및 농도장에 대한 난류 모델기법으로서 사용되었으며 log-law에 기반을 둔 유동장에 대한 벽모델이 바닥면과 건물 표면에 적용 되었다. 건물의 형상은 가상경계법을 이용해 직교좌표계에서 구현되었다.

Fe-aluminides have the potential to replace many types of stainless steels that are currently used in structural applications. Once commercialized, it is expected that they will be twice as strong as stainless steels with higher corrosion resistance at high temperatures, while their average production cost will be approximately 10% of that of stainless steels. Self-propagating, high-temperature Synthesis (SHS) has been used to produce intermetallic and ceramic compounds from reactions between elemental constituents. The driving force for the SHS is the high thermodynamic stability during the formation of the intermetallic compound. Therefore, the advantages of the SHS method include a higher purity of the products, low energy requirements and the relative simplicity of the process. In this work, a Fe-aluminide intermetallic compound was formed from high-purity elemental Fe and Al foils via a SHS reaction in a hot press. The formation of iron aluminides at the interface between the Fe and Al foil was observed to be controlled by the temperature, pressure and heating rate. Particularly, the heating rate plays the most important role in the formation of the intermetallic compound during the SHS reaction. According to a DSC analysis, a SHS reaction appeared at two different temperatures below and above the metaling point of Al. It was also observed that the SHS reaction temperatures increased as the heating rate increased. A fully dense, well-bonded intermetallic composite sheet with a thickness of 700 μm was formed by a heat treatment at 665˚C for 15 hours after a SHS reaction of alternatively layered 10 Fe and 9 Al foils. The phases and microstructures of the intermetallic composite sheets were confirmed by EPMA and XRD analyses.

The distribution of light in a randomly scattering medium can represent problems found in many area. Particularly, in the clinical application of lasers for Photodynamic therapy(PDT) or in the fluorescence spectroscopy for biological tissue, turbidity plays a very important role. The influences of fluorophor, scatterer, and absorber in turbid material by light scattering were interpreted for the scattered fluorescence intensity and wavelength. The molecular properties have been studied by laser induced fluorescence spectroscopy in scattering medium as tissue. It has been found that the effects of optical properties in scattering media could be investigated by the optical parameters(μs, μa ,μt). Experimental and Monte Carlo simulation method for modelling light transport in tissue was applied. The experimental results using a randomly distributed scattering medium were discussed and compared with those obtained through Monte Carlo simulation. It'll be also important in designing the best model for oil chemistry, medicine and application of medical engineering.

본 연구는 지붕개폐형 구조물에서 지붕을 개폐함으로써 나타나는 음장의 특성변화를 파악하기 위하여 1/20스케일의 축소모형을 제작하고 이를 대상으로 개폐율을 조절하면서 음장변화를 측정 분석하였다. 공간의 음향설계 시 사용되는 기존의 설계 및 평가파라메타들을 검토한 결과, 잔향음의 감쇠과정이 비선형적이며 기존의 잔향감 평가파라메타인 잔향시간에 의해서 적절한 설계 및 성능평가가 이루어지기 어려울 것으로 분석되었다. 특히 비선형적 감쇠구간에 대한 선형적 curve-fitting에 의해 실제 청감과는 거리가 먼 매우 긴 잔향시간이 도출되어 실질적인 효용성이 의심된다. 따라서 잔향시간(T30)을 음향설계 및 평가과정에서 중요설계변수로 활용 시 완공 후 얻게 되는 음장특성과 상이한 결과를 초래할 가능성이 있다. EDT의 경우 전체적으로 초기감쇠시간은 개폐율이 증가할수록 짧아지는 경향을 나타내었다. 주파수별로 저주파수대역에서의 감쇠율이 가장 높게 나타났으며 고주파수 대역으로 갈수록 감쇠율은 둔화되는 것으로 평가되었다. 명료도 관련 파라메타인 D50 또한 개폐에 따른 음장의 변화를 효과적으로 나타내고 있는 것으로 분석되었다. 객석부위별로는 지붕개폐면에 직접 노출되지 않는 객석에서 개폐율 증가에 따라 선형적인 감쇠현상이 나타나고 있으나, 직접 노출되는 객석의 경우에는 40%이상의 개폐율에서는 명료도와 잔향감에 영향을 거의 미치지 않는 것으로 나타났다.

모노머, 광개시제, 바인더 폴리머로 이루어진 고분자 필름 상에는 광원에 의해서 홀로그라피 기록이 이루어지며, 이는 투과되는 광원과 회절되는 광원 사이의 비를 나타내는 회절 효율을 비교함으로써 기록 효율성을 측정할 수 있다. 본 연구는 이전 연구[1]에서 진행된 솔-겔 바인더를 이용한 포토폴리머 시스템에서 측정된 실험적인 회절 효율과 중합 속도를 바탕으로, 홀로그라피 기록 시간에 따른 이론적인 회절 강도를 모사하고, 이를 실험적인 값과 비교해보았다. Frist harmonic diffusion model이 이론적인 바탕이 되었고, 이 식은 폴리머가 빛에 의해서 photopolymerization되는 과정에서, 모노머의 중합과 확산 사이의 관계를 나타내는 식으로 실험 시스템 상에서 중합과 확산 속도를 계산함으로써 시스템을 이해할 수 있었으며, 특히, 다른 바인더 함량과 레이저 세기에 따른 홀로그라피 기록을 살펴봄으로서, 홀로그라피 기록 과정을 추측해 볼 수 있었다.

The organic acids in ambient were sampled by high efficiency diffusion scrubber (HEDS) and analyzed by IC. Most of organic acids showed high linearity (r²＞0.999) of the calibration curve and good repeatability (RSD＜10%). The detection limit of organic acids was about 7 pptv. The concentration of acetic acid was ranged from 0.43~1.74 ppbv, formic acid was ranged from 0.28~1.85 ppbv. Since the organic acids are one of odor compound species with instant production characteristics and affected easily by weather, continuous analysis method is better than intermittent method to determine these compounds. The sampling and analysis process can be automated and performed in real-time by continuous sampling of HEDS and IC.

최근 다양한 목적의 대공간 사용이 보편화되고 있다. 이들 공간에 대한 다목적요구로 인해 최근 건립되는 대형 스포츠시설들은 스포츠뿐만 아니라 공연과 같은 다양한 이벤트를 수용하도록 요구받고 있다. 다양한 이벤트 상태의 제공을 위해서 건물의 일부를 부분적으로 개폐하는 방식의 사용이 빈번해지고 있으며 이와 같은 부분적 개폐는 자유음장과 확산음장의음향적 연결을 초래하여 음향설계단계에서 어려움을 초래할 것으로 예상된다. 본 연구에서는 1/10 축소모형을 이용하여 확산음장과 자유음장의 음향적 연결에 따른 음장의 음향특성을 측정 분석하였다. 연구결과, 저중주파수 대역에서의 잔향시간은 개구율이 증가함에 따라 고주파수 대역에서보다 빠른 감쇠를 나타내었다. 또한 EDT는 모든 주파수대역에서 개구율 증가에 선형적으로 비례하여 감쇠하는 것으로 나타났다. 명료도는 개구율이 12.5%에 이르기까지 거의 영향을 받지 않으며 그 이후에는 선형적으로 비례하여 증가하였다. 에너지 감쇠패턴의 분석결과, 이중 및 삼중의 감쇠패턴이 나타나고 있으며, Schroeder 적분에 의한 잔향시간의 산출은 부적절한 것으로 판단된다. 따라서 부분적 개방형 공간의 잔향예측에 있어서 EDT가 보다 적절한 것으로 판단된다.

The diffusion behavior of phenol, toluene and benzoic acid in aqueous SDS solution was examined. It showed a similar experimental results for phenol and toluene. The diffusion coefficients of the solutes were characterized by the presence of two distinct regions: below the cmc and above the cmc. For phenol and toluene, it remained approximately unchanged when the SDS concentration was below the cmc. Above the cmc there was an apparent decrease in the diffusion coefficients of the two solutes with increasing SDS concentration. However, for benzoic acid the diffusion behavior was different from that of phenol and toluene. The diffusion coefficient of benzoic acid decreased slightly with increasing SDS concentration, however the diffusion coefficient was almost constant above the cmc. For benzoic acid the diffusion behavior was dependent on the joint contribution of benzoic acid molecules as well as the benzoate ions.