• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.5
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• pp.532-537
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• 2004

FEF(Focused Electromagnetic Field) technique was newly developed that is based on the induction principle exciting electromagnetic field. The technique consists of an induction wire and a sensor for detecting electromagnetic field, and is applied in a non-contact mode. In this study, the technique was applied to the evaluation of EDM slits in some conductive materials - aluminum alloy, stainless steel and Inconel alloy. The voltage in the non-defect region is depended upon the measurement lift-off. The voltage signals on defects are measured with peak values, and the peak values changed with the depth of defects. The voltage distributions for all conductive materials are the same trend.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.9
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• pp.666-673
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• 2009

The turbulent swirling flow field characteristics of a gun-type gas burner with a combustion chamber were investigated under the cold flow condition. The velocities and turbulent quantities were measured by hot-wire anemometer system with an X-type probe. The turbulent swirling flow field in the edge of a jet seems to cause a recirculation flow from downstream to upstream due to the unbalance of static pressure between a main jet flow and a chamber wall. Moreover, because the recirculation flow seems to expand the main jet flow to the radial and to shorten it to the axial, the turbulent swirling flow field with a chamber increases a radial momentum but decreases an axial as compared with the case without a chamber from the range of about X/R=1.5. As a result, these phenomena can be seen through all mean velocities, turbulent kinetic energy and turbulent shear stresses. All physical quantities obtained around the slits, however, show the similar magnitude and profiles as the case without a chamber within the range of about X/R=1.0.

• Korean Journal of Human Ecology
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• v.14 no.4
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• pp.673-681
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• 2005

Sewing is an important process in clothes-making. It is directly or indirectly connected to a factor of fitness, as is the case of pattern making and design. The purpose of this study is to compare and analyze the sewing methods for tight skirts currently being sold by twelve clothing companies on the market. For the purpose, the skirts, which was released in 2002 Fall season, was physically disassembled and then every sewing detail was closely investigated. The major findings are as follows: All sorts of the skirts show different sewing methods in hemlines, back slits, and zipper. Hemlines and zippers, hand-sewn, are often used by high-price brands. Brands that emphasize trends usually use machine sewing. Specifically, the sewing methods applied in the allowances at the upper part of the back slit show significant differences among brands. One method leaves allowances enough in both sides for the stability of the skirts, another trims both allowances very closely, and the other trims only left-side allowance down to the edge of the back slit. This study findings will be helpful not only in understanding sewing techniques for skirts and improving its quality, but also in offering more comfortable and superior clothes for consumers.

• Journal of Power System Engineering
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• v.10 no.3
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• pp.23-31
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• 2006

Mean velocities and turbulent characteristics in the three-dimensional flow fields of a gun-type gas burner were measured by using triple hot-wire probe (T-probe) in order to compare them with the results already presented by X-type hot-wire probe (X-probe). Vectors obtained by the measurement of two kinds of probes in the horizontal plane and in the cross section respectively show more or less difference in magnitude each other, but comparatively similar shape in overall distribution. Axial mean velocity component along the centerline shows that the value by T-probe is about ten times smaller than that by X-probe above the range of X/R=3. Also, the axial component of turbulent intensity along the centerline appears the biggest difference between the two probes. Moreover, axial mean velocity component, axial turbulent intensity component and rotational along the Y-directional distance show a big difference between slits and swirl vanes. On the whole, the values by T-probe appear smaller than those by X-probe.

• Journal of the Korean Society of Costume
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• v.64 no.7
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• pp.143-155
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• 2014

This study focuses on Yusam, a military raincoat that was worn during the Joseon Dynasty. The purpose of this study is to review the types and management system of Yusam. Documentary records, paintings and relics were used as research materials. Yusam was recorded as either Yusam(油衫) or Yu-ui(油衣) in writing. It usually looked like a skirt and was worn like a cape, but there were differences in length. Some of them took the form of a short coat with half-sleeves and side slits. Research analysis results of Silrok, Ilseongrok and the archives of the military camp in the later Joseon are as follows: First, Mokyusam and Jiyusam coexisted as military raincoats. Mokyusam was made with cotton and perilla oil, while Jiyusam was made with traditional Korean paper, a cotton edging and perilla oil. Second, the differences between general Yusam and military Yusam include the material of the clothing, the materials for waterproofing, the color, and the manufacturer. Third, each military camp supplied soldiers with hundreds to thousands of Yusam. Military officers and King's guards wore Mokyusam because Mokyusam was higher than Jiyusam. Fourth, soldiers Yusam together with Yujeongeon, Chorip, Galmo, or Hwihang as a hat. Fifth, the higher the rank, the higher the price of Yusam and the longer the term of usage. On the other hand, as the rank got higher, the cost of the supplementary oil rose, while the duration of usage got shorter.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.4
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• pp.126-132
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• 2009

Automotive heat exchangers use louver fins for their high efficiency. However, the efficiency can significantly drop for constructional vehicles or heavy equipments due to dust deposited on the louver fins with narrow slits. Thus it is necessary to develop new fins that lead to less fouling, so that a better performance can be achieved after exposure to a dusty environment over long period of time. New wavy fins were considered in the study and numerically analysed to compare with louver fins in the areas of air-side pressure drop, heat release rate, and particulate deposition. In addition, an experiment was done on the pressure drop and the particulate deposition. The results showed that the wavy fins would be a better choice for long-term use due to the excellent dust-proof performance in comparison to louver fins, in spite of the initial inferior performance of heat release.

• Journal of Hydrogen and New Energy
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• v.20 no.2
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• pp.125-132
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• 2009

Cylinder shaped air-breathing PEMFC has been developed to have small volume, low contact resistance and better air accessibility to the open cathode. This cylinder shaped design consists of an anode cylinder with helical flow channel and a cathode current collector with slits. The pressure distribution measurement according to the shapes was performed. The test result indicated that cylinder shaped fuel cell has better pressure distribution compared with the planar shaped fuel cell. The better pressure distribution was connected to the higher performance. The maximum power density of cylinder shaped fuel cell was about 20% higher than the planar shaped fuel cell. The maximum power density of the developed cylinder shaped air-breathing PEMFC with dry hydrogen was $220\;mW/cm^2$ and with humidified hydrogen was $293\;mW/cm^2$.

• Journal of the Korean Society of Costume
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• v.61 no.9
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• pp.97-113
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• 2011

To develop the work clothes for the employees in the mechatronics industry in South Korea, a questionnaire survey on many aspects of the work clothes such as type, color, detailed design and function preference of the subject employees has been carried out in the study. The results throughout the survey highlighted certain functions such as extensibility, thermal and air permeability of importance for the work clothing performance. To improve the discomfort caused by some work motions (i.e. squatting down, ascending/descending the stairs, raising arms), more allowances were given to the measurements (i.e. body rise + 2cm and crotch depth + 1cm for squatting down pose; thigh circumference + 1cm and knee circumference + 1cm for ascending/ descending the stairs pose; chest circumference + 5~6cm and jumper length to the level of hip circumference line for raising arms pose) for work clothes patternmaking. The evaluation of the two types of spring/summer and winter work clothes' clothing comfort and wearer mobility suggested certain points to improve the clothing performance (e.g. ventilation slits on the back pleats, arm pits and collar band of the spring/summer suit using net material and lining for the winter suit using quilted thermal materials) and wearer mobility (e.g. pants hem buckles for the easy work motion), which also enabled to fulfill the workers' work clothes design preference.

• Journal of the Korean Society of Costume
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• v.57 no.9
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• pp.16-31
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• 2007

This study is about the costume depicted upon the fraction of fresco which was excavated from Kumseong-li, Hwadae-Gun, Hamkyungbuk-Do, North Korea in 2004. According to the characteristics of its relics, this tomb was reported to belong to Parhae Dynasty(698-926). The fraction of fresco only shows below part of the knees of a man. A light red colored robe reaches down to his ankles on the back, whereas front part of it looks tucked up, which is likely to have slits on both side seams. Although tightly wrapped shins were reported as a pair of gaiters, there is no decisive evidence on the fresco. I suggest another possibility that this man wore slim pants. Also in order to figure out if these shins are considered as gaiters, I proceed comparative research on the historical sources about gaiters of countries and eras adjacent to Parhae. Consequently the idea that people of Parhae might have used gaiters turned out to be acceptable. The black boots show rather basic style: the toe tips are not pointed up, boot leg doesn't look either wide or long. These boots can not be identified with Ammohwa(暗摸靴) which the envoy Yang(楊) gave the protocol Miyakoyoshika(都良香) at his official visit to Japan, because Ammohwa has not yet been properly defined.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.5
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• pp.1269-1279
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• 1995

An experimental study is carried out on turbulent diffusion flames stabilized by a circular cylinder in a divergent duct flow. A commercial grade gaseous propane is injected from two slits on the rod as fuel. Flame stability limits, as well as size and temperrature of recirculation zone, are measured by direct and schlieren photographs to clarify the characteristics and structure of diffusion flames and to assess the effect of various divergent angle of duct. The results of the present study are as follows. Temperature in the recirculation zone decreases with increasing divergent angle. The blow-off velocity in parallel duct is higher than that in divergent duct. Critical blow-off velocity is expected to be about 8-12 degree through blow-off velocity pattern. Regardless of divergent angles, the length of recirculation zone is nearly constant, and this length becomes longer with rod diameter. Pressure gradient has an effect on the eddy structure in shear layer behind the rod. With the increase of divergent angle, large scale eddies by dissipated energy in shear layer are split into small scale eddies, and the flame becomes a typical distributedreacting flame.