• Design & Manufacturing
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• v.13 no.2
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• pp.22-29
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• 2019

This study conducted a research as to condensation heat transfer by using three types of flat micro multi-channel tubes with different processing of micro-fin and number of channels inside the pipes and different sizes of appearances. In addition, identical studies were conducted by using smoothing circular tubes with 5mm external diameter to study heat transfer coefficient. The condensation heat transfer coefficient showed an increase as the vapor quality and mass flux increased. However, each tube shows little differences compared to 400kg/m2s or identical in case the mass flux are 200kg/m2s and 100kg/m2s. The major reason for these factors is increase-decrease of heat transfer area that the flux type of refrigerant is exposed to the coolant's vapor with the effect of channel aspect ratio or micro-fin. In addition, the heat transfer coefficient was unrelated to the heat flux, and shows a rise as the saturation temperature gets lower, an effect that occurs from enhanced density. The physical factor of heat transfer coefficient increased as the channel's aspect ratio decreased. Additionally, the micro pin at the multi-channel type tube is decided as a disadvantageous factor to condensation heat enhancement factor. That is, due to the effect of aspect ratio or micro-fin, the increase-decrease of heat transfer area that the flux type of a refrigerant is exposed to the vapor is an important factor.

• Korean Journal of Culture and Social Issue
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• v.27 no.1
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• pp.113-138
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• 2021

In this study, a meta-analysis was conducted on a total of 34 studies (14 academic papers, 20 dissertations in academic journals) conducted in Korea from 2000 to 2020 in order to understand the relationship between work-family conflict, work-family enhancement and social support. (N=17,530). Work-family conflict and work-family enhancement were used for analysis by dividing the direction into the case where the direction was not distinguished, the direction from work to home, and from home to work. The social support was divided into family, spouse, organization, supervisor, coworker, and not classified according to support resource, and a subgroup analysis was conducted. Depending on the type of support, a subgroup analysis was conducted by dividing into emotional, instrumental, informational, and appraisal support. As a result of the analysis, both support resources and types showed a significant relationship with work-family conflict and work-family enhancement. It was confirmed that the most significant relationship was changed according to each sub-factor and the direction of conflict and enhancement. Based on the above research results, the implications and limitations of this study were presented and directions for future research were suggested.

• 한국약용작물학회:학술대회논문집
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• 2011.09a
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• pp.398-399
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• 2011

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.122-122
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• 2013

In this talk, some optical properties of quantum dot based mode-locked diode lasers and photonic crystal nano lasers will be discussed. Linewidth enhancement factor, chirp and interband injection locking technique of quantum dot mode-locked lasers will be presented. Also various types of photonic crystal buried heterostructure lasers toward coherent nano laser will be covered as well.

• Textile Coloration and Finishing
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• v.4 no.2
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• pp.64-68
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• 1992

The charge-transfer(CT) complexes derived from phenothiazine as donor and quinonoid compounds as accepters were evaluated as coloring matter. Light fastness of the intermolecular charge-transfer(CT) complex dyes as well as absorption wavelength is an important factor when the complexes are applied to coloring matters. The photofading mechanism of CT complex dyes of phenothiazine and accepters were examined. The addition of effective radical scavenger, antioxidant and photostabilizer gave a remarkable enhancement of the photostability of CT dyes.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1584-1587
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• 2005

Although the picture quality of today's displays is very good already, a continuous improvement is desirable as the new larger display sizes increase the visibility of artifacts. A contributing factor for picture quality enhancement through smart video processing and algorithm design is the information gathered from video statistics. Interesting parameters gathered from video statistics are e.g. the image- and display load, the usage of the color gamut, the estimated power consumption and the occurrence of static image parts. Examples of applications that can benefit from video statistics are power calculations, color gamut mapping algorithms, dynamic backlight control for LCD panels and LED backlights for LCD panels.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.867-869
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• 2003

Vacuum tube arrays (VTA) with a submicron dimension were fabricated by using anodic aluminum oxide (AAO) nano-templates. The field emission characteristics of Ni nanowires show a turn-on voltage in the range of 11.0-14.0 V and a field enhancement factor in the range of 560-2790. The distance between the tips of Ni nanowires and the anode was much smaller than that between the tips and the anode of conventional designs.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.10
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• pp.2773-2778
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• 1994

Tumbling motion is very effective for turbulence enhancement during compression process in the cylinder of 4-valve engines. In this paper the tumble decay mechanism for different intake port configuration were measured using laser Doppler velocimetry. Analysis of the tumble decay mechanism was achieved by means of two non-dimensional parameters, defined as tumble eccentricity and shape factor in tumble velocity profile, in addition to the tumble moment.

• Proceedings of the Microbiological Society of Korea Conference
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• 2007.05a
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• pp.94-94
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• 2007

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.764-767
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• 2007

We investigated the field emission of single carbon nanotube including the anode effect by calculating the tunneling probability of an electron. The experimental results from this study were in agreement with our theoretical calculations. The constant enhancement factor was calculated using an approximation of the potential barrier.