• Journal of the Optical Society of Korea
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• v.13 no.1
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• pp.22-27
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• 2009

Target design study to improve the quality of an accelerated proton beam from the interaction of a high-intensity short pulse laser with an overdense plasma slab has been accomplished by using a two-dimensional, fully electromagnetic and relativistic particle-in-cell (PIC) simulation. The target consists of a thin core part and a thick peripheral part of equivalent plasma densities, while the ratio of the radius of the core part to the laser spot size, and the position of the peripheral part relative to the fixed core part were varied. The positive effects of this core-peripheral target structure could be expected from the knowledge of the typical target normal sheath acceleration (TNSA) mechanism in a laser-plasma interaction, and were apparently evidenced from the comparison with the case of a conventional simple planar target and the case of the transversal size reduction of the simple planar target. Improvements of the beam qualities including the collimation, the forward directionality, and the beam divergence were verified by detailed analysis of relativistic momentum, angular directionality, and the spatial density map of the accelerated protons.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.12
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• pp.1639-1645
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• 2002

Micro engine that includes Micro scale combustor is fabricated. Design target was focused on the observation of combustion driven actuation in MEMS scale. Combustor design parameters are somewhat less than the size recommended by feasibility test. The engine structure is fabricated by isotropic etching of the photosensitive glass wafers. Electrode formed by electroplating of the Nickel. Photosensitive glass can be etched isotropically with almost vertical angle. Bonding and assembly of structured photosensitive glass wafer form the engine. Combustor size was determined to be 1 mm scale. Movable piston is engraved inside the wafer. Ignition was done by nickel spark plug which was electroplated with thickness of 40 ${\mu}{\textrm}{m}$. The wafers were bonded by epoxy that resists high temperature. In firing test due to the bonding method and design tolerance pressure buildup by reaction was not confirmed. But ignition, flame propagation and actuation of micro structure from the reaction was observed. From the result basement of design and fabrication technology was obtained.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.259-261
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• 2005

분류 방법으로서의 SVM(Support Vector Machine)은 커널 방법과 함께 사용됨으로써 그 유용성을 크게 향상시켰다. 커널 방법은 일반적으로 입력 데이터의 자질(feature)로 나타내는 공간으로부터 높은 차원의 공간으로 데이터를 사상(mapping)시키는 역할을 하게 되나, 기본적으로는 데이터간에 새로운 거리(metric)를 부설해주는 역할을 하는 것이다. 지금까지 나온 다양한 커널 방법은 구조화된(structured) 데이터에 대해 커널 형태로 거리를 부여하는 방법을 제시한다. 본 논문에서는 DNA의 작용을 모델링하여 만든 새로운 커널이 miRNA(micro RNA)와 mRNA(messenger RNA)쌍에 대한 발현 여부를 분류해 내기 위해 커널 형식으로 거리를 부여하는 방법을 보인다. 이 방법은 실리콘 컴퓨터가 아닌 실제 DNA분자로 실험할 수 있도록 설계된 것을 고려할 때 여러 종류의 DNA 코드를 분석하는 데 사용될 수 있는 새로운 분자컴퓨팅 방법이다.

• Journal of Environmental Impact Assessment
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• v.26 no.6
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• pp.508-523
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• 2017

This study monitored the changes before and after restoration of ecological stream focusing on the places which are applied Sustainable Structured wetland Biotop (SSB) system and ecological Fish-way for restoration of Maeno stream. A total of 11 species and 191 individuals of fishes were founded out which were not verified inhabitation before restoration at SSB wetlands. Especially, it was could identified that micro habitat and healthy Fish-way was created because the restored target species, Microphysogobio yaluensis and Iksookimia koreensis were identified that habitation was monitored in SSB wetland. Amphibian have been restored to a number of Rana nigromaculata found in and around wetlands at the time of the third survey, which is highly active after restoration. Specified endangered species class 1 and natural monuments designated by the Ministry of Environment, Lutra lutra lutra, as a Mammalian, uses the wetlands and ecological Fish-way as habitat areas, and the his habitat is restored. In the case of Flora, vascular plants emerging in the survey area were increased to 7 and 13 species before restoration and 15 and 19 species directly after restoration, and 22 species and 33 species after restoration. Vegetation after restoration was found to be a basic producer of various ecosystems and a plant community that contributes to the purification of water quality such as Phragmites japonica communities. As the result of water quality monitoring, the average of treatment efficiencies were BOD 64.3%, T-N 47.2%, T-P 80.7%. Successful treatment of the nonpoint pullution source, which is a limiting factor to disturb the ecosystem, creatively restored the target species in the water quality class I, II.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.6
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• pp.1-6
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• 2002

Micro engine that includes Micro scale combustor is fabricated. Design target was focused on the observation of combustion driven actuation in MEMS scale. Combustor design parameters are somewhat less than the size recommended by feasibility test. The engine structure is fabricated by isotropic etching of the photosensitive glass wafers. Electrode is formed by electroplating of the Nickel. Photosensitive glass can be etched isotropically with almost vertical angle. Bonding and assembly of structured photosensitive glass wafer from the engine. Combustor size was determined to be 1mn scale. Piston in cylinder moves by fuel injection and reaction. In firing test, adequate engine operation including ignition, flame propagation and piston motion was observed. Present study warrants further application research on MEMS scale internal combustion power units.

• Korean Journal of Environment and Ecology
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• v.22 no.3
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• pp.268-279
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• 2008

This study is aimed at typifying the crossing structure and inquiring into the characteristics of vegetation distribution by type targeting Dorimcheon(stream), Banghakcheon(stream), Seongnaecheon(stream) and some sections of Yangjaecheon(stream) in Seoul through the establishment of basic data for restoring vegetation in urban stream. This research classified the crossing structure into 56 slope types and 31 vertical types in combination with the three items, such as bank slope(vertical style, slope style) of bank, absence or presence of waterside, and revetment structure. This research derived nine slope types including SB1 (revetment of low water level-revetment with vegetation, and revetment of high water level-nature riverside) including SG5(revetment of low water-concrete, and revetment of high water level-riprap work), and three vertical types, such as VH4(bank revetment-wet masonry), and VH7(bank revetment - concrete )from the target survey areas. Among these, both revetment of low water level and high water level were found to be distributed on the longest section as the type of SG7 and VG7 structured in concrete. As a result of inquiry and analysis of micro topography structure and vegetation structure of eight major types, this research could find out the influence of crossing structure on plant vegetation according to the characteristic by typified item, but there appeared no distinct characteristic of vegetation distribution by crossing structure.