• Journal of Advanced Marine Engineering and Technology
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• v.30 no.6
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• pp.685-692
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• 2006

In a general centrifugal pump, if it is operated in a two-phase flow the activity of the impeller usually degrades and occasionally losses its function. However, the effect of break down of centrifugal pump due to entrained air has not been clarified yet. This paper shows the air-water two-phase flow characteristics of closed type and semi-open type impellers. In a sing1e-phase flow, closed-type impeller has higher efficiency and head. But in air-water two-phase flow semi-open type impeller's rates of decreases of efficiency and head are decreased.

• Korean Journal of Applied Biomechanics
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• v.19 no.3
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• pp.449-455
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• 2009

The purpose of this study was to analyze the kinetics variables of GRF by dtance type during forehand stroke. Eight high school tennis players, who have never been injured for last six months, in Busan were chosen for the study. They performed horizontal swing and vertical swing that it was done each five consecutive trial in the condition of square, semi-open and open stance. It was filmed by 6 video camera and used with 3-dimensional motion analyzer system and GRF system. The following kinetic variables were analyzed in relation to left leg and right leg GRF. The conclusion were as follow: 1. In square and semi-open stances, the horizontal ground reaction force was decreased at impact in left leg regardless of swing type, whereas open stance was increased at impact to the tiptoe in both legs. 2. In square and semi-open stances, the vertical ground reaction force was increased at impact in left leg regardless of swing types, whereas open stance was decreased at impact to vertical direction in both legs.

• Kyungpook Mathematical Journal
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• v.54 no.2
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• pp.173-188
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• 2014

In this paper, a new class of open sets, namely ${\gamma}^*$-pre-open sets was introduced and its basic properties were studied. Moreover a new type of topology ${\tau}_{{\gamma}p^*}$ was generated using ${\gamma}^*$-pre-open sets and characterized the resultant topological space (X, ${\tau}_{{\gamma}p^*}$) as ${\gamma}^*$-pre-$T_{\frac{1}{2}}$ space.

• The Research Journal of the Costume Culture
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• v.20 no.3
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• pp.416-429
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• 2012

The purpose of this study was to examine the effects of VM components(facade color and show window type) on store image and purchasing intention of fashion stores. The subjects were 428 male and female university students in Daejeon and Chungnam province. The measuring instruments were 6 stimuli manipulated by $3{\times}2$ factorial design of facade color and show window type, and a self-administrated questionnaire consisted of store image, purchasing intention, and subjects' demographic characteristics. The results were as follows. First, facade color mainly affected store image and purchasing intention. White color was preferred as more positive images(pleasurable, comfortable, neat, and modern), and showed higher purchasing intention than brown color. Second, show window type affected some store images. Semi-open type was perceived as more pleasurable image than enclosed type, whereas enclosed type was perceived as more luxurious, neat, and attractive image than semi-open type. However, show window type didn't affect purchasing intention. Third, subject' sex affected store image and purchasing intention. Male subjects perceived more positively on store image and had higher purchasing intention than females. This study suggested that facade color and show window type are important VM components affecting store image and purchasing intention.

• Publications of The Korean Astronomical Society
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• v.32 no.3
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• pp.421-438
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• 2017

Through the short-period variability survey program, we obtained time-series BV CCD images for $1.5^{\circ}{\times}1.0^{\circ}$ region around the young open cluster NGC 457. As a result, we have detected 61 variable stars including 31 new ones after checking light curves of all stars by eyes. The 61 variable stars were included 14 ${\delta}$ Scuti variable stars, a ${\beta}$ Cephei variable star, 10 variable Be and slowly pulsating B stars, 13 eclipsing binary stars, 21 semi-long periodic or slow irregular variables and an RR Lyrae variable star, respectively. Many variable B-type stars were known through a well-defined zero-age main sequence to the ${\beta}$ Cepheid region of NGC 457. Most of the variable B-type stars found this paper were known variable stars. But, 11 out of 14 ${\delta}$ Scuti variable stars were newly discovered. The new variable stars except for ${\delta}$ Scuti stars were 4 variable B-type stars, 5 eclipsing binaries and 11 semi-long periodic or slow irregular variables. We have performed frequency analysis for all ${\delta}$ Scuti stars, a ${\beta}$ Cepheid star and an RR Lyrae star.

• Publications of The Korean Astronomical Society
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• v.25 no.2
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• pp.31-49
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• 2010

Next to Paper I (Jeon 2009a), time-series BV CCD images of the open cluster M38 were taken for 4 nights on December, 2009. The observations have been carried out for total 27 nights. In addition to the 20 variable stars in the Paper I, the discovery of 44 new variable stars has been presented in this paper: $6{\delta}$ Scuti stars, $2{\gamma}$ Doradus stars, 18 eclipsing binaries and 18 semi-long periodic and/or slow irregular type variable stars. For the V photometry of the ${\delta}$ Scuti and ${\gamma}$ Doradus stars, multi-frequency analysis was performed using the Discrete Fourier Transform and linear least-square fitting. The period search for the eclipsing binaries and the semi-long periodic and/or slow irregular type variable stars was performed by phase fitting method. As a result, the periods for 23 variable stars among the 44 ones were defined.

• Journal of Ocean Engineering and Technology
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• v.28 no.4
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• pp.345-350
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• 2014

A special usage impeller pump for ballast water treatment is part of an offshore plant's structure. It has to maintain a high corrosion resistance in an extreme environment, in which it can contact several kinds of aqueous solutions. The duplex stainless steel used in such severe environments is known to have corrosion resistance and excellent mechanical properties. This study estimated the performance of an impeller pump system designed using duplex stainless steel through a computational fluid dynamics analysis. As a result, it was determined that the pressure drop increases and the impeller performance is lowered if the equivalent roughness is enlarged. The surface precision of the duplex stainless steel must be consistently maintained. If thisis the case, it was determined that the existing STS steel can be substituted for the Duplex stainless steel.

• Publications of The Korean Astronomical Society
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• v.24 no.1
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• pp.19-34
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• 2009

From the short-period variability survey (SPVS) in Bohyunsan Optical Astronomy Observatory, I obtained time-series BV CCD images in the region of the young open cluster M29 (NGC 6913) for 15 nights from May 30, 2008 to September 17, 2009. I observed 48 variable stars including 45 new ones. They consisted of 5 $\delta$ Scuti, a Cepheid, 16 eclipsing binaries and 24 semi-long periodic and/or slow irregular type variable stars including $\beta$ Cephei and LPB type stars. For the rest two ones, the type of variability was not defined. I also checked the variability of the 26 known variable stars listed in the GCVS. Only three ones among 26 known variable stars confirmed variability.

• Korean Institute of Interior Design Journal
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• v.21 no.4
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• pp.96-105
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• 2012

The fundamental purpose of this study is whether Show Window Display actually affect on purchase and if it does, how much Show Window Display have influence on the buyer's satisfaction. Show windows are most important at clothing stores. The show open types of domestic clothing stores are usually open-type and semi open-type. Show Window Display types of low and middle prices stores are generally opened, horizontal and storied type and the shape, height, opening type and use of ground floor are different by regional distinct features. Generally Show Window Display are consisted by lights, mannequins and directed props. In buying patterns, an impulse buying has more stronger effect than a scheduled buying, a substituted buying and non-buying. An impulse buying are strongly affected by Design and others are prices. The reason why Show Window Display affecting on purchase is the satisfaction of Design and the strong stimulus to purchase(impulse buying), and then Show window Display used by all components strongly has an effect on it. Factors of purchase desires were Design, price and quality in order and factors of purchase motivations were the motivation of clothing design and the motivation of impulse buying. Thus the effects of Show Window Display and factors of purchase motivations are same. As a result of this study, differentiated Show Window Display methods of clothing stores affect the value of goods, the stimulus of purchase and fostering sales effectiveness. Therefore the instruction of Show Window Display methods are indicated by this study.

• Journal of the Korean Institute of Educational Facilities
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• v.10 no.3
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• pp.37-43
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• 2003

This study investigates the physical characteristics of indoor rest zones using the Space Syntax Method. A conceptual framework is based on analysis of design works presented in competitions(544 rest zones of 24 buildings on 7 campuses). The analysis on the unit type of rest zones showed that they were mostly available as open type, followed by semi-open type and outdoor rest places. On the other hand, by classifying the shape of whole building into traffic lines and nodal points, it was found that the buildings with 3 or more traffic lines have lower availability than others, because the buildings required more nodal points along a little higher complexity and zoning formed at increased nodal points between building masses. The analysis on the location of rest zones on traffic lines showed that hall type was most excellent in the level of availability. Finally, the analysis on the floor height showed that hall-like open rest places and outdoor places like rooftop garden functioned as a factor to enhance the integration of different spaces. In conclusion, this research will help the follow-up studies make spatial creation planning that may enhance the spatial efficiency and availability of Indoor rest zones on the campus.