• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.340-345
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• 2002

Passengers in automobile or train are exposed to a worse noise environment when they are in the tunnel than in the open field. This is due to a relatively higher space density of sound energy by multiple reflection phenomenon of noise generated by operation of transportation vehicles from tunnel wall compared to open field. In this study, noise characteristics of subway train running through a tunnel were investigated at straight/curved track and tunnel type(semi circular/box). Also the noise measured simultaneously at inner and outer sides of train running through a tunnel, so that the coherence of the various noise sources of subway train to inner noise was evaluated.

• 대한인간공학회지
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• 제4권2호
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• pp.11-15
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• 1985

Nowadays, there are many situations which the conventional control system can't be applied any more (e.g. nuclear waste disposal sites, radioactive laboratories, the deep ocean and the vacuum of the outer space). New control system must be considered such as supervisory control system in those environment. Using computer graphic robot simulation, supervisory control which can cope with this situation is compared to manual control. As a performance measure of these comparisons, task time and task error are used. And task difficulties and time delay are considered as a variation factor. According to the result of this study, supervisory control is superior to manual control generally. Especially in the situation including task difficulties and time delay, the superiority is much greater.

• KIEAE Journal
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• 제2권3호
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• pp.39-45
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• 2002

Double facades are built to allow natural ventilation in high rise buildings and buildings with high outside noise level. In high rise Buildings the gains in summer can be reduced by sufficient sun protection devices placed outside the rooms in the ventilated space between the inner and outer facade. To evaluate the energetic performance, three buildings with double facade were monitored for at least one year (Siemens Building in Dortmund/Germany, Victoria Insurance Company in Duesseldorf/Germany and RWE Tower in Essen/Germany). The results document the indoor climate, the boundary conditions for further planning and the possibilities for high rise buildings without or with little cooling facilities.

• 건축역사연구
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• 제20권6호
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• pp.169-184
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• 2011

The following research of the road network of Jeju-Eupseong during Daehan Empire period has a twofold purpose: to study some characteristics of the road network at that time; and, to restore it to the original form of that period before a newly constructed road, called Shinjakro, has been established. As an attempt to trace the old shape of Jeju-Eupseong, this study analyzed some historical factors based on the first land cadastral map which was made in 1914, including outskirts of Jeju-Eupseong; such as castle itself, castle gate, road, bridge, lots of land, etc. Then this study also tried to restore the old road network of Jeju-Eupseong, through finding the original land-lot shape in the land cadastral map. There was five Shinjakro made between 1914 and 1917. The road network before then was composed of the double east-west axes and the single north-south axis. These axes was connected to some important place of the inside of Jeju-Eupseong; such as castle gates, fountains, Gaek-sa, etc. There were many branch lines between these main axes at about 80-120m intervals. Also there was an outer road along the outer wall of castle, connected with each castle gates. Especially, the north-west axis was the baseline which divided into two large parts, a government office area and non-government area (housing and commercial street for the people). Finally, this paper examines that the road network of Jeju-Eupseong was the true result for the efficient function of the city, especially considering natural geographical conditions and environment of living of that time.

• 천문학회보
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• 제40권2호
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• pp.42.2-43
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• 2015

Massive stars play a major role in the interstellar energy budget and the shaping of the galactic environment. The water molecule is thought to be a sensitive tracer of physical conditions and dynamics in star-forming regions because of its large abundance variations between hot and cold regions. Herschel/HIFI allows us to observe the multiple rotational transitions of H2O including the ground-state levels, and its isotopologues toward high-mass star-forming regions in different evolutionary stages. Photodissociation regions (PDRs) are also targeted to investigate the distribution of water and its chemistry. We present line profiles and maps of H2O using data from two guaranteed-time key programs "Water In Star-forming regions with Herschel" and "Herschel observations of EXtra-Ordinary Sources". We analyze the temperature and density structures using LTE and non-LTE methods. We also estimate turbulent and expansion velocities, and abundance of water in the inner and outer envelopes using the 1D radiative transfer code. Around high-mass protostars we find H2O abundances of ~10-8-10-9 for the outer envelope and ~10-4-10-5 for the inner envelope, and expansion and turbulent velocities range from 1.0 km s-1 to 2.0 km s-1. The abundances and kinematic parameters of the sources do not show clear trends with evolutionary indicators. The Herschel/HIFI mapping observations of H2O toward the Orion Bar PDR show that H2O emission peaks between the shielded dense gas and the radicals position, in agreement with the theoretical and the observational PDR structure. The derived H2O abundance is ~10-7 and peaks at the depth of AV ~8 mag from the ionization front. Together with the low ortho-to-para ratio of H2O (~1) presented by Choi et al. (2014), our results show that the chemistry of water in the Orion Bar is dominated by photodesorption and photodissociation.

• 한국항해항만학회지
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• 제36권7호
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• pp.585-590
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• 2012

On the basis of the potentials for the growth of local economy and the result of investigation of the ocean space development status, an ocean resort complex was proposed at the small harbor with a parallel beach in the east coast of Korea. As the development plan needs to reclaim the noticeable amount of coastal water area together with the applied shore facilities, it is necessary to analyze their impacts. Here, it was intended to analyze the coastal environment change such as water circulation and bottom change because of the development plan. A horizontal two-dimensional numerical model was applied to represent the combined impact of wind waves and tidal currents to sediment transport in that coastal region. Based on the result of 30 days tidal current simulations considering major four tidal components of $M_2$,$S_2$,$K_1$ and $O_1$ for the upper and lower boundaries and wind field data, bottom change was discussed. Flow velocities were not changed much at outer breakwater of Yangpo harbor. Bottom was eroded by maximum 1.7m after construction but some locations such as lee side of outer breakwater and some islets near the entrance shows isolated accretions. Although it needs more field observations for bottom change in the period of construction, the numerical calculation shows that there exist small impacts near the entrance area and coastal boundaries because of the development.

• Journal of Astronomy and Space Sciences
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• 제23권3호
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• pp.259-268
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• 2006

우주 공간에서 GPS 수신기의 사용은 지구저궤도에서 일반화가 되었다. 최근 대부분의 위성은 위성 위치를 찾기 위한 항법 해로써 GPS 수신기를 사용한다. 그러나, GPS 수신기로부터 직접 획득한 항법 해의 정확도는 지도 제작과 같은 위성 활용에서 충분하지가 않다. 정밀궤도결정과 같은 후처리 개념이 위성 위치 정확도를 향상시키기 위해서 위성 자료 처리에 최근 적용되고 있다. 정밀궤도결정은 GPS 수신기의 항법 해가 아닌 원시 측정 자료를 사용한다. 원시 측정 자료의 성능은 GPS 수신기의 원시 측정 자료 정확도 및 추적 루프 알고리듬에 의해서 결정된다. 이 논문에서는 원시 측정 자료의 성능을 평가할 수 있는 기법을 제안하였다. GPS 수신기의 항법 해와 정밀궤도결정의 항법 해를 얻기 위한 지구저궤도위성의 시험 환경 및 절차를 기술하였다. 추가로, GPS수신기의 항법 해, 원시 측정 자료, 정밀궤도결정의 항법 해에 대한 정확도를 분석하였다. 제안된 기법은 일반적인 저궤도 위성에 적용 가능하다.

• 우주기술과 응용
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• 제4권1호
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• pp.27-47
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• 2024

뉴스페이스(New Space) 시대에 이르러 궤도상 서비싱(OOS, on orbit servicing) 임무를 수행하기 위한 인공위성들이 개발되고 있다. 궤도상 서비싱을 위한 다양한 임무는 고장수리, 재급유, 견인, 구성품 교체, 우주 상 건설 등의 여러 임무가 있으며, 이를 수행하기 위해 로봇팔 탑재체가 탑재되어야 한다. 로봇팔 탑재체는 기존 인공위성의 탑재체와 달리 고정된 상태로 움직이지 않는 것이 아니라 임무 수행을 위해 지속적으로 움직여야 하는 탑재체라는 특징이 있으며, 또한 인공위성의 구조체 내부에 존재하는 것이 아닌 우주공간에 직접적으로 노출된 상태로 임무 수행을 해야 한다는 특징이 있다. 이러한 탑재체의 특징으로 인해 극한의 우주 열환경에서 이상 없이 운용될 수 있는 열 설계 및 해석은 필수적이나, 로봇팔 열 설계 및 해석에 대한 논문은 그리 많지 않은 실정이다. 본 논문에서는 현재까지 개발된 로봇팔 탑재체에 대한 열 설계, 해석에 대한 사례들을 소개 및 정리하였으며, 마지막에는 앞으로 개발할 로봇팔 탑재체의 열 설계 및 해석에 대한 방향을 제시해 보고자 한다.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2006년도 추계학술발표회
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• pp.131-135
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• 2006

이 연구의 목적은 지구 내부의 동적 코어에서 공간과 시간에 따라서 발생하는 지구 자기장 구조와 그에 따른 경년 자차변화를 모델링하고 연구하는 것이다. 지구의 주 자장과 경년 자차변화에 대한 구형 조화 모델은, 외부 간섭자장이나 내부의 불균일 등이 없다는 가정 하에 안정되고 왜곡되지 않은 지구상 어떠한 위치에서의 지구자장의 구조와 세기를 나타낼 수 있다. 이 연구에서는 선박용 디지털 컴퍼스를 이러한 지구자장 에 적용하는 경우를 고려해 지구의 원 조화 모텔에 대한 실제 적용방법과 절차를 기술하였다.

• 자연과학논문집
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• 제16권1호
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• pp.77-86
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• 2005

The study was designed to learn about features of landscape trees and shrubs on an exclusive area-specific outer space planting plan in Noeun Apartment Complex in Daejeon Metropolitan City. the exclusive areas were no more than $60m^2$ and $85m^2$ and the landscape areas ranged from 15% and 30%, respectively according to exclusive area-to-plottage ratios. The study showed that trees were likely to be more densely planted in exclusive areas not exceeding $60m^2$ than in exclusive areas over $85m^2$. It also found that the greater the exclusive areas were, the larger the number of species became. Regardless of the size of an exclusive use, however, the species number of evergreen trees and shrubs remained small, while there was no remarkable difference in vegetation due largely to a massive influx of special trees or shrubs such as Eastern white pines (Pinus strobus) and Korean azaleas (Rhododendron yedoensis var. poukhanense). The introduction of trees with the height over four meters and the diameter of breast height (DBH) exceeding 15 meters was strictly limited to Japanese red pins (Pinus densiflora) and Japanese zelkovas (Zelkova serrata). In conclusion, it is necessary for us to introduce fresh species of trees and especially develop evergreen trees and shrubs to make the environment of the apartment complex more comfortable and make a vegetation experience feasible.