• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.159-162
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• 2012

Combustion in a narrow space has been interested as a model of meso-scale combustors (or micro-combustors). Premixed flames have been used to overcome flame quenching in a narrow space and non-premixed flames have been used to improve flame stabilization. In this study, overall characteristics of premixed flame and non-premixed flame in narrow combustion spaces were reviewed. Various effects such as the flow velocity distribution, thermal interaction, enhanced mass diffusion were discussed and an eventual structure of the flame at the extinction limit was introduced.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.574-579
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• 1995

Saturated boiling heat transfer experiment in a hemispherical narrow space is conducted using Freon-113 to investigate an additional heat removal capability through a hypothetical gap between lower head and degraded core. The narrow space of 1mm consists of a 124mm diameter heated stainless steel hemisphere and a glass outer vessel. Within the hemispherical narrow space large coalesced bubbles are produced and these bubbles rise in random direction, causing liquid flow in from the opposite side to fill the region. Such flow in random direction makes the flow field in the narrow space very chaotic and thus enhance heat transfer. The heat transfer coefficient is higher at lower angle and at higher heat flux. The present study shows that the liquid from upper region can effectively penetrate into the gap and augment the heat removal capability through tile gap.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1173-1178
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• 2007

The robot for narrow space is used in searching, investigating or cleaning. Up to now variety of researches on in-pipe robots have been introduced. However it is still hard to overcome vertical or curved passage. In most cases of narrow space robots are able to travel just aimed diameter which was selected when those are developed. Also, a large percentage of robots are not able to detect the configuration of pipe or circumstance. In this paper we present a robot called PAROYSⅡ for narrow space with vertical and curved passage. This proposed robot is not affected at all to variance of pipes, vertical or horizontal passages, curved pipes, projecting parts and parallel planes. In addition to that, it will perceive the internal configuration of pipe and terrain, which will be not only available to control navigating scheme by itself, but also mappable about the passage which the robot traveled. Core points in the design and structure are introduced and preliminary verification is given.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.49.2-49.2
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• 2018

Flux calibration for narrow band photometric data gives us an opportunity to get a line flux of extended targets. We developed flux calibration processes for narrow band photometry using broad band filters as a continuum indicator. We derived parameters for color correction and zero point correction including color terms. Applying our method, we successfully subtracted continuum emissions and calibrated the emission lines from an FU Ori type object, V960 Mon.

• Journal of Power Electronics
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• v.13 no.4
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• pp.647-655
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• 2013

In this paper, an approach to reduce the common-mode voltage and to eliminate narrow pulse for implemented AC-DC matrix converters is presented. An improved space vector modulation (SVM) strategy is developed by replacing the zero space vectors with suitable pairs of active ones. Further, while considering the commutation time, the probability of narrow pulse in the conventional and proposed SVM methods are derived and compared. The advantages of the proposed scheme include: a 50% reduction in the peak value of the common-mode voltage; improved input and output performances; a reduction in the switching loss by a reduced number of switching commutations and a simplified implementation via software. Experimental results are presented to demonstrate the correctness of the theoretical analysis, as well as the feasibility of the proposed strategy.

• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.9-12
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• 2012

In this study, opposed flow combustion was re-visited in a narrow channel. Various flame behaviors were observed. Due to the confined structure of the combustor in this study, flame structures at very narrow strain rate could be stabilized and their characteristics were investigated. This study will be helpful to understand overall flame behavior of non-premixed flame in a narrow combustion space, and will also be useful to develop small combustors.

• Journal of the Society of Disaster Information
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• v.12 no.4
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• pp.342-349
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• 2016

The objectives of this study is analysis of the characteristics of fire risk and survey of narrow dwelling space(the Karaoke, Gosiwon etc). The narrow dwelling space has special structure characteristics; the narrow and the complex escape rote. Gosiwon have very separate and exclusive space room, so have the problem a suppression of fire. Furthermore almost Karaokes located in basement have a complex and limitary escape rote. Therefore we should research and development the exploration equipment that search a source of the fire and a emergency rescuer in the scene of the fire.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.3
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• pp.242-248
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• 2017

Recently, Population has been concentrated in cities due to rapid economic growth. As a result, urban buildings are becoming more dense, high-rise, and diversified. The shape of these urban buildings increases the risk of fire, accidents and crime. The narrow living space has the characteristic of the unchanged floor. In case of a fire, the living space of the narrow residence is large in the damage because the smoke diffusion rate is fast. The radio wave transmittance and transmission distance of wireless communication used in fire fighting operations vary depending on the type of building materials and buildings. Therefore, this paper analyzes the building materials and structural characteristics of the narrow residential space for efficient fire fighting operations. We have developed a communication environment solution for a narrow residential space for the optimal fire fighting operation through the measurement of the radio wave transmittance and the transmission distance of the wireless communication.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.2
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• pp.33-44
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• 2015

This study was performed to propose the site selection plan for the restoration of the target Narrow-mouth Frog(Kaloula borealis) habitat, and has developed the AHP model to select the optimal site for narrow-mouth frog habitat restoration on the basis of the narrow-mouth frog Habitat Suitability Index (HSI) items (factors and variables). The assessment areas were established by the narrow-mouth frog HSI factors such as space, feed, cover, water(breeding), threatening factors and others, and the sub-assessment items by each assessment area were established based on the narrow-mouth frog HSI variables. The weighting values of the assessment areas and items were calculated by the developed AHP method. The weighting values of the 5 assessment areas were arranged in order as cover(0.283), water(breeding)(0.276), feed(0.230), space(0.147), and threatening factor(0.064). The final weighting values of the 14 assessment items were arranged in order of height as low-rise grassland(0.190), soil quality(0.178), and stones and between the stones(0.105). The scoring criteria according to the assessment items and factors were marked and applied by equal intervals considering the criteria by HSI items of the narrow-mouth frog and finally the scoring criteria diagram has been proposed for the optimal site selection of the narrow-mouth frog habitat restoration.

• Korean Institute of Interior Design Journal
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• v.21 no.5
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• pp.23-33
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• 2012

This study evaluated two educational spaces, one middle school and one high school in point of universal design. The survey method with an observation and measuring method was used. The subject were 238 students of a middle and a high school. They evaluated their schools according to 53 universal design related items which consisted of 5 principles. Findings were as follows ; 1) The width of passage between desk and desk was very narrow and there is the threshold at the door of classroom. The students evaluated them negatively, too. Also, they indicated that the size of individual locker was small and the corner of furniture was sharp. 2) The width of door and passage was narrow and the floor was not flat in restroom. The design quality such as color and finishes was not good. Also, the students evaluated all these items negatively. 3) The dining space was too big. That is, so many students takes meals in one big space. The dining tables were arranged in a long rows and the width between them was also so narrow to pass through. 4) The student of high school evaluated their educational environments more negatively than ones of middle high school. This means that the high school students were more dissatisfied with their school environment. The educational environment should be designed on the base of their students' needs.