• Journal of Environmental Science International
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• v.12 no.1
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• pp.35-40
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• 2003

With increasing population densities in cities, underground facilities and entertainment locations are proliferating at a rapid pace in efforts to maximize the use of land. The purpose of this study is to evaluate CO concentration level of subway stations having underground platforms in Busan Metropolitan City, from September to November 2000, over seven times. The places of inquiry include Yonsan-dong station, Somyon station, Busan station, Nampo-dong station and Dusil station. The samplings were conducted at three points of each station, i.e. gates, ticket gates, and platforms. The component of CO concentration is the main elements of indoor air quality evaluation. The total concentrations and average concentrations of CO were the higher at the Somyon station. The distribution of CO concentrations at each station, generally was higher at gate than ticket gates and platforms. The I/O ratios(I-platforms, 0-gates) were expressed highly than 1 at the Yonsan-dong station, Busan station, Nampo-dong station and were lower than 1 at the others.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2004.11a
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• pp.153-159
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• 2004

Apartment Housing in Korea has been developed rapidly and settled as a main housing form for short period, 40 years. In spite of increase of the apartment housing, it has pointed out that spatial organization of the apartment housing could accommodate residents 'various life style and life cycle. One of such planning methods is a flexible housing. Starting with the Gangbyoun-Siebeom apartment, flexible housing has been developed as merchandising constantly. However, flexible housing doesn't have enough understanding concerning lifestyle or life cycle of user individually, and it also means lack of comprehension and of flexibility, layout from modular coordination and planning of housing component. Therefore, according to the flexibility, the major goal of this research is to analyze the difficulty in realizing further of flexible housing in Korea and suggest implementation and alternatives or directions of flexible housing in Korea.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1014-1015
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• 2008

Safety critical systems are those in which a failure can have serious and irreversible consequences. Nowadays digital technology has been rapidly applied to critical system such as railways, airplanes, nuclear power plants, and vehicles. The main difference between analog system and digital system is that the software is the key component of the digital system. The digital system performs more varying and highly complex functions efficiently compared to the existing analog system because software can be flexibly designed and implemented. The flexible design make it difficult to predict the software failures. This paper reviews safety standard and criteria for safety critical system such as railway system and suggests development process, ordering management and assessment process for railway software with more detail description.

• Proceedings of the KIEE Conference
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• 2008.10c
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• pp.174-176
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• 2008

HYOSUNG manufactured and tested 1kw class PEFC systems to generate electrical and thermal energy for each residential usage. In particular, HYOSUNG developed Power conditioning system that performs about 91% electrical conversion ratio specified in 1kW class PEFC systems. Prior to system integration, we tested each performances of components to derive control issues from it. In addition, we have been developing the adequate simulator to describe and predict system performance. In this paper, we verified HYOSUNG's 1kW class PEFC systems are valid for residential energy sureces by testing the characteristics of systems and performances of main component.

• Journal of the Korean Society of Safety
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• v.12 no.4
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• pp.143-152
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• 1997

Probabilistic Safety Assessment(PSA) is an engineering analysis of the possible contributors to the risk from a nuclear power plant. It consist of three phases named as Level 1, 2 and 3. Level 1 PSA mainly focused in this paper is the phase of system analysis which includes the development of accident scenarios and the frequency estimation of each scenario. It covers also the system reliability analysis, component data analysis, and human reliability analysis. PSA have become a standard tool in safety evaluation of nuclear power plants. The main benefit of PSA is to provide insights into plant design, performance and environmental impacts, including the identification of dominant risk contributors and the comparison of options for reducing risk.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.135-140
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• 2011

The battery pack, a main component of NEV(Neighborhood Electric Vehicle), needs cooling system when it is charging or discharging to prevent the degradation of the battery charging efficiency. The purpose of this study is to analyse the effects of cooling methods, changing positions of inlet and outlet and changing area ratios of inlet and outlet. It has been observed that in the point of uniform cooling suction from the exit side is more efficient than blowing from the inlet. And there is a suitable inlet/outlet area ratio in maximizing the mass flow rate. The numerical analyse using a commercial code STAR-CCM+ version 4.02 were used for the study.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.7
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• pp.956-965
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• 1998

Hot-wire measurement of the longitudinal and radial velocity components and Reynolds stresses are reported for developing turbulent flow in a strongly curved 180 deg. pipe and its tangents. Slanted wire is rotated to 6 directions and the voltage outputs of them are combined to obtain the mean velocities and Reynolds stresses. Significant double maxima in the longitudinal velocity component appear in the bend. V-profiles reveal the development of a strong secondary flow. This secondary flow is induced by the transverse pressure gradient set up between the outer(r$\sub$o/) and inner(r$\sub$i/) wall region of the bend. Another second cross-stream flow develops after .theta.=135 deg. and its direction is opposed to that of main second flow.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.18 no.2
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• pp.214-220
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• 2009

The spindle is the main component in machine tools. The static and dynamic stiffness of the spindle directly affect the machining productivity and surface integrity of the workpiece. The static and dynamic stiffness of the spindle depend on the shaft size, bearing arrangement, bearing span length, and so on. Therefore, the selection of shaft size and bearing span length are important to improve the spindle stiffness. This paper presents the determination of shaft size and bearing span length in spindle design step. In order to select the optimal bearing and built-in motor locations with constraint conditions, the extreme vertices design was applied. The results show that extreme vertices design is usable for spindle design with design constraints.

• Journal of Korean Neurosurgical Society
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• v.39 no.2
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• pp.152-155
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• 2006

Central neurocytoma is a rare, well-differentiated neuronal tumor and is usually located in the lateral or third ventricle of young adults. The occurrence of an intraventricular tumor with a characterisitic magnetic resonance image findings including isointense signal in T1-weighted images, the presence of a cystic component, small signal-void areas due to calcification, heterogenous and hyperintense "bubbly" appearance in T2-weighted images in a young patient should suggest preoperatively the diagnosis of central neurocytoma. The typical immunohistochemical finding, positivity for synaptophysin, is the main pathological feature. We experienced two cases of central neurocytomas with typical radiological and histopathological findings. We expect growth arrest of these cases by subtotal removal to avoid postoperative neurologic deficit followed by radiation therapy.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.7
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• pp.938-943
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• 2016

Development of body hair is an important physiological and cellular process that leads to better adaption in tropical environments for dairy cattle. Various studies suggested a major gene and, more recently, associated genes for hairy locus in dairy cattle. Main aim of this study was to i) employ a variant of the discordant sib pair model, in which half sibs from the same sires are randomly sampled using their affection statues, ii) use various single marker regression approaches, and iii) use whole genome regression approaches to dissect genetic architecture of the hairy gene in the cattle. Whole and single genome regression approaches detected strong genomic signals from Chromosome 23. Although there is a major gene effect on hairy phenotype sourced from chromosome 23: whole genome regression approach also suggested polygenic component related with other parts of the genome. Such a result could not be obtained by any of the single marker approaches.