• Journal of the Korean Society for Aviation and Aeronautics
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• v.18 no.3
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• pp.70-76
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• 2010

In this study, we surveyed the operating status of the Light Sport Aircraft(LSA) in Korea, and reviewed the minimum requirements of the airpark for LSA. We are discuss about increased aerodrome traffic density and safety improvement, through the installation of the exit taxiway. The shape of the exit taxiway of an airpark used in LSA is a rectangle for usable two way direction of runway. The array types of exit taxiway influence paved and unpaved runway occupancy time of LSA.

• Transactions on Electrical and Electronic Materials
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• v.11 no.5
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• pp.230-233
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• 2010

The authors investigated the anodization mechanism of aluminum in an oxalic acid solution, and the electrochemical reaction is very unique for pore formation via the dissolution process, which is very dependent on the surface geometry in nanoporous alumina templates. The cross-sectional nanochannels showed that the geometrical curvature of the initial surface can cause the branching of nanochannels to be adjusted in volume occupancy to be direct to the electric field normal to the surface. The nanoporous alumina with the crystalline $\gamma-Al_2O_3$ phase showed hexagonal ordering at a voltage of 40 V, with a nanohole distance of 102 nm from the charge density oscillation of the oxalic acid solution.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.7
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• pp.1374-1389
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• 1994

In this paper, a novel M-ary orthogonal CDMA scheme which utilizes time hopping codes and binary orthogonal sequences is proposed for personal communication system. Its modulated output signal has the characteristics of greater bandwidth occupancy and lower spectral density level as well. So this scheme is useful for spectrum overlay with existing narrowband communication systems which occupy current radio frequency channels. This paper investigates system characteristics through the analysis of modulated output signal power spectrum, and demonstrates the possibility of spectrum overlay.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.227-232
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• 2011

최근 피난제약이 많은 대형 및 고층건축물의 증가함에 따라 화재 시 많은 인적피해가 예상된다. 이에 국내외에서는 화재로부터 인명을 보호하기 위한 방법으로 건축물의 성능 위주 피난 안전성평가를 실시하고 있는데 이를 위해서는 해당 건축물을 이용하는 사용자의 특성을 파악할 필요가 있다. 특히 건축물의 피난용량을 결정하는 재실자 밀도는 중요한 평가요소로 국외의 경우에는 건축물 용도에 따른 단위면적 당 재실 인원 즉, 재실자 밀도를 산정하여 규정하고 있으나 현재 우리나라는 건축법에서 건축물의 용도 및 규모만을 고려한 사양적 기준을 적용하고 있어 재실자를 고려한 피난설계가 제대로 이루어지지 않고 있다. 이에 본 연구는 재실자 밀도 고려한 성능위주 피난용량 확보기술을 위하여 우선적으로 초고층 건축물을 선정하여 재실자 밀도 실태조사를 하였다. 이를 토대로 국내 초고층 건축물의 재실자 밀도 산정 시 기초자료로 이용하고자 한다.

• Journal of the Korean Chemical Society
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• v.61 no.1
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• pp.7-11
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• 2017

The extended $H{\ddot{u}}ckel$ method is employed to analyze the interaction of carbon monoxide with the TiC(001) surfaces, both perfect and containing carbon vacancies. CO exhibits a similar ${\sigma}$-donation interaction for both $Ti_{25}C_{25}$ and $Ti_{25}C_{23}$ clusters, as deduced from the fact that the populations of the CO $5{\sigma}$ orbital are identical upon adsorption, but it bonds more strongly with the $Ti_{25}C_{23}$ than with the $Ti_{25}C_{25}$ because the metal d electron density in $Ti_{25}C_{23}$ provides ${\pi}$ back-bonding interactions with CO that are absent in $Ti_{25}C_{25}$. This work suggests that a difference in reactivity toward CO of stoichiometric TiC and TiC with carbon defects is connected with the occupancy of $2{\pi}^*$ orbitals that leads to a significant weakening of the C-O bond.

• Journal of the Korean housing association
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• v.15 no.2
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• pp.55-62
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• 2004

Apartment design in residential Area is restricted by building distance limit code. Building distance limit decreases gradually to the 0.8H(height), and residential area has 250% site area ratio by building code, so site using has become efficient. In this study, examine the relationship between present building distance limit and right of daylighting environment by computer simulation. As well, high-rise residential officetel and multipurpose residential building becomes increase in commercial non-residential area. In the domestic, residential type multipurpose building made at the business area or central business area has 400∼800% site area ratio by building code. However, at a dweller's point of view, there are much lacks of environmental consideration to provide suitable daylighting environment. And, POE: Post Occupancy Evaluation is not completed yet. In this study, however, progress architectural environment prediction, basis by right of daylighting, and examine the possibility of daylighting by architectural distance limit code in residental area and by high-rise, high-density residential building in non-residental downtown area.

• Fire Science and Engineering
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• v.26 no.2
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• pp.1-10
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• 2012

While a performance based sprinkler design method has been widely used in UK and USA according to fire hazards of occupancies, Korean fire safety industry could not yet accept it due to nonstandardization on risk level of various occupancy. Even only two or three spray pattern sprinkler was produced in Korea fire safety industry, therefore, various spray pattern sprinklers have not yet introduced to major occupancies. Spray pattern sprinklers with one of two K value have been used in all occupancies in Korea Market. UK and USA's Fire industry should produced the spray sprinklers with various K-factors and protection area due to performance based sprinkler design requirement. Therefore the fire load density for main occupancies has been investigated in order to compare with installation standard in advanced countries. Eventually a lot of variations in orifice and K factors of standard heads were set up including special heads needed for high hazard areas such as large drop type, enlarged orifice type and early suppression fast response.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.2
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• pp.153-160
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• 2017

It may be reasonable to consider density per unit area over time rather than analyze traffic volume, which is simply the traffic volume per unit of time, in assessing the maritime traffic congestion of a certain area. This study contributes to the standardization of maritime traffic congestion assessment methods for the maritime traffic safety diagnosis institute while seeking a new method to minimize evaluation error due to converted traffic volume per ship tonnage level. To solve this problem, a method to evaluate maritime traffic congestion by comparing the area occupied by a vessel with the area of its route using vessel identification data from the Automatic Identification System (AIS) has been proposed. In this new model, it is possible to use actual data due to the development of information and communication technology, reducing conversion error while allowing for the evaluation of maritime traffic congestion by route.

• Fire Science and Engineering
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• v.32 no.6
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• pp.134-140
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• 2018

This study examined the adequacy of a school classroom's occupant load density standard to cope with the issues associated with the decreasing number of students and regional variations. Therefore, this study analyzed the occupant load density standards of kindergarten, elementary school, middle school, high school, and universities using the data open to the public by the Ministry of Education. The results revealed a high variance in the occupant load density according to the school type. The median values were 1.49, 3.45, 2.64, 2.45, and $3.41m^2/person$ for kindergarten, elementary school, middle school, high school, and universities, respectively. Although the occupant load density was higher than the current standard ($1.9m^2/person$), except for kindergarten, the present standard did not need to be improved immediately, considering the purpose of calculating the maximum occupancy. On the other hand, if improvements are made in line with other enhancements of a national education policy, it will be possible to mitigate the measure to $2.5m^2/person$ based on the survey results.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.1
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• pp.30-38
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• 2014

The purpose of this study is to build and manage environment models with line segments from sonar range data on obstacles in unknown and varied environments. The proposed method therefore employs a two-stage data-transform process in order to extract environmental line segments from range data on obstacles. In the first stage, the occupancy grid extracted from the range data is accumulated to form a two-dimensional local histogram grid. In the second stage, a line histogram extracted from a local histogram grid is based on a Hough transform, and matching serves as a means of comparing each of the segments on a global line segments map against the line segments to detect the degree of similarity in the overlap, orientation, and arrangement. Each of these tests is formulated by comparing one of the parameters in the segment representation. After the tests, new line segments can be found at maximum-density cells in the line histogram, and they are composed onto the global line segment map. The proposed technique is demonstrated in experiments in an indoor environment.