• Proceedings of the Korea Air Pollution Research Association Conference
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• 2006.04a
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• pp.407-409
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• 2006

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2007.10a
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• pp.418-419
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• 2007

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.216.2-216.2
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• 2008

• International Journal of Aeronautical and Space Sciences
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• v.13 no.2
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• pp.170-187
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• 2012

Recent years have seen an outpour of revived interest in the use of airships for a number of applications.Present day developments in materials, propulsion, solar panels, and energy storage systems and the need for a more eco-oriented approach to flight are increasing the curiosity in airships, as the series of new projects deployed in recent years show; moreover, the exploitation of the always mounting simulation capabilities in CAD/CAE, CFD and FEA provided by modern computers allow an accurate design useful to optimize and reduce the development time of these vehicles.The purpose of this contribution is to examine the different aspects of airship development with a review of current modeling techniques for airship dynamics and aerodynamics along withconceptual design and optimization techniques, structural design and manufacturingtechnologies and, energy system technologies. A brief history of airships is presented followed by an analysis of conventional and unconventional airships including current projects and conceptual designs.

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.06a
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• pp.92-106
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• 2004

Elemental dry deposition fluxes were measured using dry deposition plates from March to June 1998 in Seoul, Korea. During this spring sampling period several yellow sand events characterized by long-range transport from China and Mongolia impacted the area. Understanding the impact of yellow-sand events on atmospheric dry deposition is critical to managing the heavy metal levels in the environment in Korea. In this study, the measured flux of a primarily crustal metal, Al and an anthropogenic metal, Pb was used with two hybrid receptor models, potential source contribution function (PSCF) and residence time weighted concentration (RTWC) for locating sources of heavy metals associated with atmospheric dry deposition fluxes during the yellow-sand events in Seoul, Korea. The PSCF using a criterion value of the 75th percentile of the measured dry deposition fluxes and RTWC results using the measured elemental dry deposition fluxes agreed well and consistently showed that there were large potential source areas in the Gobi Desert in China and Mongolia and industrial areas near Tianjin, Tangshan, and Shenyang in China. Major industrial areas of Shenyang, Fushun, and Anshan, the Central China loess plateau, the Gobi Desert, and the Alaskan semi-desert in China were identified to be major source areas for the measured Pb flux in Seoul, Korea. For Al, the main industrial areas of Tangshan, Tianjin and Beijing, the Gobi Desert, the Alashan semi-desert, and the Central China loess plateau were found to be the major source areas. These results indicate that both anthropogenic sources such as industrial areas and natural sources such as deserts contribute to the high dry deposition fluxes of both Pb and Al in Seoul, Korea during yellow-sand events. RTWC resolved several high potential source areas. Modeling results indicated that the long-range transport of Al and Pb from China during yellow-sand events as well as non yellow-sand spring daytimes increased atmospheric dry deposition of heavy metals in Korea.

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.12a
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• pp.75-75
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• 2004

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.37-38
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• 2001

Polycyclic Aromatic Hydrocarbons(다환방향족 탄화수소류, 이하 PAHs)는 두 개 이상의 벤젠 고리로 구성되어 있는 반휘발성 유기물질로서 가스상과 입자상에 모두 존재한다. PAHs는 주로 불완전 연소에 의해서 생성되며, 주요 고정 오염원은 주거 난방, 코크 산업, 소각이고, 주요 이동오염원은 자동차 엔진이다. PAHs에는 강한 발암성 혹은 돌연변이원성을 가진 화합물들이 포함되어 있고, 주변 대기에 널리 분포되어 있을 가능성이 높기 때문에 일반 대중이 쉽게 노출될 수 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.111-112
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• 2001

대기로부터 침적된 물질로 인해 토양오염과 수질오염 현상이 심화될 뿐만 아니라 환경 생태계도 영향을 받는다는 것이 밝혀지면서 대기 침적 현상에 대한 관심이 커지고 있다. 침적은 대기 중의 여러 미량 물질들이 환경계에 미치는 영향과 그들의 이동을 조절하는 중요한 기작 중 하나이다. 중금속은 가장 오래전부터 알려진 독성물질로서, 약 30가지 금속이 사람에게 독성을 발현하는 것으로 알려져 있고, 그 중 일부 중금속은 발암성을 가지고 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.171-172
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• 2001

본 연구는 1999년 6월부터 시작된 주암호에 대한 대기침적 특성과 오염기여도평가 결과를 토대로, 주암호 수질보전대책을 수립하는데 필수적인 기여 배출원을 규명하기 위해 수행되고 있다. 주암호로 침적되는 오염물질의 양을 효과적으로 줄이기 위해서는 배출원과 피해지점간의 관계를 평가 할 수 있는 모형의 개발과 이용이 필수적이다. (중략)

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.68-73
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• 2002

In standard teletherapy, a treatment plan is generated with the aid of a treatment planning system, but it is common to perform an independent monitor unit verification calculation (MUVC). In exact analogy, we propose and demonstrate that a simple and accurate MUVC in Intensity Modulated Radiotherapy (IMRT) is possible. We introduce a concept of Modified Clarkson Integration (MCI). In MCI, we exploit the rotational symmetry of scattering to simplify the dose calculation. For dose calculation along a central axis (CAX), we first replace the incident IMRT fluence by an azimuthally averaged fluence. Second, the Clarkson Integration is carried over annular sectors instead of over pie sectors. We wrote a computer code, implementing the MCI technique, in order to perform a MUVC for IMRT purposes. We applied the code to IMRT plans generated by CORVUS. The input to the code consists of CORVUS plan data (e.g., DMLC files, jaw settings, MU for each IMRT field, depth to isocenter for each IMRT field), and the output is dose contribution by individual IMRT field to the isocenter. The code uses measured beam data for Sc, Sp, TPR, (D/Mu)$\_$ref/ and includes effects from MLC transmission, and radiation field offset. On a 266 MHZ desktop computer, the code takes less than 15 sec to calculate a dose. The doses calculated with MCI algorithm agreed within +/- 3% with the doses calculated by CORVUS, which uses a 1cm x 1cm pencil beam in dose calculation. In the present version of MCI, skin contour variations and inhomogeneities were neglected.