• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2003.11a
• /
• pp.251-254
• /
• 2003

'UNEP Global Environment Outlook 2000'의 자료에 의하면, 향후 1000년에 가장 심각한 환경문제는 "지구온난화" 였다. $CO_2$ 농도 증가 등으로 인한 기후변화로 지난 100년간 전 세계적으로 기온은 평균 0.3~0.6$^{\circ}C$ 상승, 해수면은 평균 25 cm 내외 상승, 프레온가스 등으로 인하여 성층권의 오존층이 파괴되어 피부암과 안질환이 급증하고 면역기능이 저하되며, 현종 식물종 8%, 조류 11%, 어류 5%, 포유류 14%가 멸종위기에 처하는 등 생물다양성의 감소, 내분비계 장애물질(환경호르몬) 증가로 유해화학물질에 더욱 노출되고 있다. (중략)

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2006.06a
• /
• pp.207-207
• /
• 2006

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2016.07a
• /
• pp.69-70
• /
• 2016

본 논문에서는 개방형 플랫폼 기반의 영상콘텐츠 제작 서비스를 위한 비즈니스 모델을 제안한다. 이는 중개형 플랫폼 구축 전략 관점에서 성격이 다른 두 고객층인 자신의 영상 자료로 영상콘텐츠를 제작하고 싶어 하는 수요자와 제작한 영상 콘텐츠 템플릿을 제공하는 공급자를 대상으로 온라인 상에서 양면시장 설립에 부합되며, 또한 교차(간접) 네트워크의 효과를 기대할 수 있다. 그리고 협업과 공유 및 맞춤 서비스를 제공함으로써 두 고객층에 상호 이익을 만족시킬 수 있는 개방형 플랫폼 기반의 비즈니스 서비스 모델이라고 할 수 있다. 이를 위해 본 논문에서는 Web 기반의 중개형 플랫폼 서비스 운영 및 구축을 위한 시스템 구성 등을 제안한다.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.16 no.11
• /
• pp.2169-2180
• /
• 1992

Solid propellant combustion is investigated for its response to several imposed pressure histories. For this purpose, it is assumed that combustion takes place in a premixed gas evaporated from a uniform melt of solid propellant. One-dimensional unsteady problem is than numerically solved for a pressure coupling, with a steady state as an initial state. The results in response to pressure of finite sinusoidal waves show that unsteady mass fluxes are sometimes quite different from those predicted by the classical quasisteady burning law of Vieile. In addition, abnormal mass flux excursions are captured for a large pressure exponent and a lower melting point.

• Journal of Korean Ophthalmic Optics Society
• /
• v.1 no.1
• /
• pp.15-22
• /
• 1996

The fine structure of retinal tissue was studied to investigate on effect of Laser irridation on the ICR mouse with electron microscope. The results obtained were as follows: 1. At the normal groups, the most retinal layers were a complex structure, consisting of several specific cells and nerve fiver. 2. In the increasing time of Laser irridation, each cell layer of retina was not uniform of the structure and band. The visual cells were severely heterochromatin swelling of cytoplasm, irregular shape & heterochromatin of nuclear, and disappear of some cytoplasm. The nucleus and nerve fiber of retinal layer was a very irregular shape, formation of vesicle, not identify of each intercellular boundary. The pigment epithelial cells were not an uniform, a large vesicle formation of cytoplasm, and a condensation & very irregular shape of nucleus.

• Journal of Welding and Joining
• /
• v.10 no.4
• /
• pp.213-221
• /
• 1992

Al$_{2}$O$_{3}$ ceramic coating layer by gas flame spraying was very porous, therefore it could not have wear and corrosion resistance at all. To get a dense and strong coating layer, a method to infiltrate an alloy into the pores of $Al_{2}$O$_{3}$ ceramic coating was investigated. Cu-Ti alloys, which had good wettability and reactivity with $Al_{2}$O$_{3}$ ceramic, were examined for infiltration. Infiltration of the alloys was performed in vacuum at 1100.deg.C. The melt of Cu-50 at % Ti alloy was well penetrated through the porous $Al_{2}$O$_{3}$ coating and tightly sealed the pores, unbounded area and microcracks in the coating. The alloy melt in the pores reacted with $Al_{2}$O$_{3}$ ceramic to produce a suboxide phase, Cu$_{2}$Ti$_{4}$O. This composite layer which was composed of $Al_{2}$O$_{3}$ and Cu$_{2}$Ti$_{4}$O phase had good microstructure and wear and corrosion resistance. Additionally, microstructures at interfaces between coating layers were greatly improved owing to the effect of vacuum heat treating.

• Magazine of the Korea Concrete Institute
• /
• v.6 no.3
• /
• pp.162-172
• /
• 1994

The flexural and horizontal shear behavior of overlaid concrete slabs with polymer interface is investigated in the present study. An experimental program was set up and several series of overlaid concrete slabs have been tested to study the effect of different surface preparations and dowel bars between old slab and overlay under service and ultimate loads. 'The cracking and ulti mate load behavior for various cases including acryl emulsion treatment and doweled joints has been studied. The present study indica.tes that the overlaid concrete slabs behave integrally with existing bottom slabs up to ultimate range for rough and doweled joints with polymer interface. The pres ent study provides a firm base for the realistic design of two-layered RC slabs in bridges.

• Proceedings of the KOR-BRONCHOESO Conference
• /
• 1996.04a
• /
• pp.89-89
• /
• 1996

CS gas(0-chlorobenzylidene malononitrite)가 우리나라 및 구미 각국에 시위진압과 군 화생방 교육에 널리 사용되고 있다. 이 CS gas는 인체에 자극적인 독성물질로 작용할 수 있다고 알려져 있으나 이비인후과 영역에 미치는 영향에 대하여는 보고가 드물어 CS gas 폭로에 의해 먼저 장애를 입을 것으로 생각되는 기관점막의 구성세포들의 변화를 관찰하기 위하여 실험동물을 사용하여 실험에 임하였다. 실험에 사용되는 실험동물은 150gm 내외의 Sprague-Dawley계 흰쥐로 대조군 5마리, 실험군 24마리를 사용하였으며 실험에 사용한 CS gas는 한영화학 CO.에서 제조한 분말형 CS gas를 사용하였다. 실험방법은 1㎥ 용적의 플라스틱 chamber에 CS분말을 투입한 후 실험동물을 넣어 CS gas를 흡입시킨 후 12시간, 1일, 3일, 5일이 경과한 후 희생시켜 기관점막의 변화를 관찰한 결과 다음과 같은 결과를 얻었다. 1. CS gas 흡입후 12시간이 경과한 흰쥐의 기관은 상피층이 증가되었고 위중층상피가 중층편평상피로 변화되었다. 2. CS gas 흡입후 1일 경과후는 기관상피층이 현저하게 감소되었다. 3. CS gas 흡입후 3일 및 5일 경과후 기관점막은 대조군의 것과 같이 거의 정상화되었다.

• Conservation Science in Museum
• /
• v.12
• /
• pp.35-45
• /
• 2011

To keep relics excavated in the era of the Japanese Colonist's rule in the Korean Peninsula in order, the National Museum of Korea selected some of horse strap pendants (Haengyeob) that were excavated from Seobongchong, Sikrichong and Geumryeongchong, and it investigated conservation and production technique. The horse strap pendants selected were classified into three, that is to say, Oval and fish-tail shape, heart shape and atypical: At the results of microscopic observation, XRF and SEM-EDS analysis, base plate was made of iron, and top plate as well as pattern plate was made of iron, copper and silver. Both Oval and fish-tail shape and heart shape horse strap pendants had horse strap pendants having same production technique and sizes at all of three ancient tombs were made of iron and copper. The gold layer of horse strap pendants except the atypical one having no gold layer were made by amalgam gilding.

• Applied Microscopy
• /
• v.31 no.2
• /
• pp.207-214
• /
• 2001

Anatomy and ultrastructure of the modifeid Krana pattern have been studied in succulent Salsola collina Pall. Cylindrical leaves exhibited the Salsoloid Kranz type containing two layers of peripheral chlorenchyma that surrounded the water storage cells and vascular tissues. Small veins were also peripherally arranged, but mostly embedded in the vicinity of the inner chlorenchma without the orderly arrangement of the concentric layering of bundle sheath and mesophyll cells. The current study mainly focused on the chlorenchyma tissue abutting such minor veins. The outer columnar layer exhibited features similar to the characteristics of palisade mesophyll cells, while the inner cuboid layer to the bundle sheath cells of a typical $C_4$ Kranz pattern. Cellular components of the inner chlorenchyma were centripetal and numerous, but starch-laden chloroplasts were rudimentary in the thylakoidal system. The outer chlorenchyma demonstrated normally developed chloroplasts having well-stacked thylakoids and plastoglobuli. Branched and complicated plasmodesmata frequently occurred in thick interfaces of the two layers, implying the active movement of the photosynthates between them. The present data were mostly congruent with one of the structural features of the C4 subtypes , NADP-ME type, reported in the $C_4$ pattern. The Kranz pattern encountered in this Salsola probably has been directly related to the structural modification that occurred during a functional adaptation to the $C_4$ photosynthesis.