• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.450-458
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• 2016

High performance small and mid-sized tractors are required for dryland and orchard operations. A power transmission system is the most important issue for the design of high performance tractors. Many operations, such as loading and lifting, use hydraulic power. In the present study, a hydraulic power transmission system for the 3-point hitch of a 50 kW narrow tractor was developed and its performance was evaluated. First, major components were designed based on target design parameters. Target operations were spraying, weeding, and transportation. Main design parameters were determined through mathematical calculation and computer simulation. The capacity of the hydraulic cylinder was calculated taking the lifting force required for the weight of the implements into consideration. Then, a prototype was fabricated. Major components were the lifting valve, hydraulic cylinder, and 3-point hitch. Finally, performance was evaluated through laboratory tests. Tests were conducted using load weights, lift arm sensor, and lift arm height from the ground. Test results showed that the lifting force was in the range of 23.5 - 29.4 kN. This force was greater than lifting forces of competing foreign tractors by 3.9 - 4.9 kN. These results satisfied the design target value of 20.6 kN, determined by survey of advanced foreign products. The prototype will be commercialized after revision based on various field tests. Improvement of reliability should be also achieved.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.2
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• pp.225-234
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• 2001

This paper represents the vector fields, three dimensional mean velocities, the turbulent intensities, the turbulent kinetic energy, and the Reynolds shear stresses in the X-Y plane of gas swirl burner with a cone type baffle plate measured by using X-probe from hot-wire anemometer system. This experiment is carried out at flow rates 350 and 450ℓ/min respectively, which are equivalent to the combustion air flow rate necessary for heat release 15,000 kcal/hr in gas furnace, in the test section of subsonic wind tunnel. The vector plot shows that the maximum axial mean velocity component exists in the narrow slits situated radially on the edge of gas swirl burner, for that reason, there is some entrainment phenomena of ambient air in the outer region of burner. Moreover, mean velocities in the initial region are largely distributed near the outer region of burner at Y/R≒0.97, but they diffuse and develop into the center flow region of burner according to the increase of axial distance. The turbulent intensities and the turbulent kinetic energy due to large inclination of mean velocity and swirl effect show that the maximum value in the initial region of burner is formed in the narrow slits situated radially on the edge of gas swirl burner and large values are mainly formed in the entire region of burner after X/R=2.4358, hence, the combustion reaction is anticipated to occur actively near this region. And the Reynolds shear stresses are also largely distributed from slite to vanes of gas swirl burner in the intial region, but their values largely disappear after X/R=3.2052.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.1
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• pp.89-96
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• 2008

The study, with regard to unsymmetrically inclined backfilled wall, was intended to estimate the lateral earth pressure, develop the equation for lateral earth pressure and eventually identify the mutual behavior, based on the modified Kellogg theory, while changing the width between the walls, wall angle, relative density and wall friction angle. To verify the geostatic pressure obtained from the study, the results in the wake of 62 kinds of model tests performed were compared and evaluated with the behaviors based on theoretical equations. As a result, the wall inclination angle was found to be the factors affecting the earth pressure the most, when both walls were inclined unsymmetrically. And the narrower the backfill space and the larger the wall inclination angle to the horizontal level, the greater the effect of the wall friction. The equation considering the wall friction reaction indicated the value, which was closer to the actually-measured earth pressure, and when the width between the warts was narrow, the arching effect appeared to be great, thereby indicating the difference between the measured earth pressure, theoretically calculated earth pressure and the geostatic pressure proved to be insignificant.

• Fashion & Textile Research Journal
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• v.25 no.1
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• pp.52-61
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• 2023

This study aimed to present data for the development of a shoe which is suitable for plus-size men (BMI 25kg/m² or higher) and to analyze the characteristics of each type of foot. The results of the study are as follows. To assess foot shape in relation to weight gain, participants were categorized into normal weight, overweight, and obese weight groups, according to their BMI indexes. Those in the normal weight group exhibited a smaller value than the overweight or obese weight group in all items. As a result of the cluster analysis, by type of foot, of the obese men category, men were classified into four BMI index groups: members of the type 1 group had a BMI index of 157 (18.4% of total sample), while for type 2 the figure was 213 (25.0% of sample), for type 3 it was 259 (30.4%), and for type 4 it stood at 224 (26.3% of total sample). Those from the type 1 group had thin ankles with narrow toes and flattened sides. Type 2 group members had thick ankles with well-developed outer feet and thick sides. Those within the type 3 group had medium-thick ankles with narrow feet but wide inner feet. Finally, those in the type 4 group had feet with a slanted side, as well as thick ankles, wide feet, and flat sides. Among these categories, the type 3 group members indicated the highest distribution.

• Laser Solutions
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• v.15 no.1
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• pp.10-14
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• 2012

Pulse laser welding was performed on C22 metal bellows. The results can be summarized as follows: Laser welded metal bellows had less thermal distortion, narrow HAZ, high aspect ratio in comparison with other welding processes like TIG, Plasma welding. Laser welded bellows has higher tensile strengths than that C22 base metal. The value of hardness in laser weld metal was measured 100-120 Hv, it was decreased compared to the base metal. It is reasoned that due to the annealed by heat input during the laser welding.

• ETRI Journal
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• v.29 no.2
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• pp.237-239
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• 2007

Interference from IEEE 802.11a systems affects ultra-wideband (UWB) systems significantly. In this letter, we suggest a novel narrow-band interference (NBI) suppression technique based on the singular value decomposition (SVD) algorithm in time-hopping pulse amplitude modulation (TH-PAM) UWB systems. The SVD algorithm is used to approximate the interference which then is subtracted from the received signals. In contrast to the conventional notch filter and rake receiver, our method is more effective and the receiver complexity can be greatly reduced.

• The Research Journal of the Costume Culture
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• v.3 no.2
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• pp.193-199
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• 1995

The purpose of this research was to study the origins and the meanings of the Kokal (고깔). Comparative linguistic analytical approaches were employed to trace the development of the word, the Kokal(고깔). Results of this study revealed that the kotkal(곳갈, 곧갈) was a general term referring to a variety of head coverings in eh period of Choson Dynasty. This broad meanings of the Kotkal(곳갈,곧갈) of the Chosun Dynasty period has been changed to a narrow sense meanings a conical cap made of folds of the material, mainly used by some of the Buddhist monks in modern Korean. Also, the phonetic value of the Kotkal(곳갈,곧갈) of the Choson Dynasty period changed to the Kokal(고깔) in modern Korean. A variety of words for the Kokal(고깔) was found in the different languages such as Latin, English, French, Turkish, German, Mongolian, and Chinese. The examination and analysis of this study indicated that the origin of the Korean word Kotkal(곳갈,곧갈) or Kokal(고깔) and the meanings of it were derived from LL. Cuculla(monk's cowl)

• Journal of the Korea Fashion and Costume Design Association
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• v.4 no.1
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• pp.5-17
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• 2002

This study aimed to investigate the relationship between ideal images of women and women's clothing fashion England between 1820s and 1850s. The age was divided into two periods, which were 1820-1836 and 1837-1850. During the first period, the ideal images of women were those of fairy, spirit, and angels, which were expressed by tight waist belt, wider and shorter skirt, top expanded sleeve, wide and flat pelerine collar, feather decoration, elaborate and curly hair style, narrow and light ballerina shoes etc.. During the second period, the ideal images for women were those of lady with modesty, quietness, and weakness. They were expressed by long and full skirt, tight or bulge over the lower arm sleeve, dropped sleeve, poke bonnet, body wrapping large shawl and sober color etc.. The result shows that the ideal images of women in 19th century England were concretely expressed by various clothing fashion including hair style, shoes, and decoration. This study sheds light on psychological, historical, and theoretical approaches to clothing.

• Journal of the Korea Institute of Building Construction
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• v.8 no.6
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• pp.65-74
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• 2008

The aim is to get comprehensive view point for the price of apartment. Apartment construction cost is the sun of land cost and building cost. Land price reflects the value of location where building stands. When the gap between price and affordability is narrow enough, effective demand promote apartment construction. The today's trends of rising price, which began in apartment housing, spreads to real estates market and finally overall consumer price. Problem is that price is decided only by supplier's interest. Equilibrium-pricing is common process in housing market. However it is important to review hedonic price and the factor of housing services and focused on the affordability of demanders. AHP analysis was used to study real needs and preference of demanders and dealt with 200 interviewees with brief checklists. We found that social factor is more important than building cost or site development. Especially location of apartment is most important to affect environment quality and accessibility to facilities.

• Journal of Korea Multimedia Society
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• v.20 no.3
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• pp.456-464
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• 2017

The epigraphy is a text on metal or a text on stone. The value of epigraphy can be used to identify historical facts of the past. It is a good record to understand the past life and culture. But it is difficult to decode the character of the epigraphy which has been exposed to the outdoor for a long time. In this study, the proposed techniques are consisted of 3 parts: (1)The surface division into information area, non- information area, and undifferentiated area. And then, (2) The selection of points in the non-information area and finding a reference plane with the minimum error. (3) Flattening the points perpendicular to the reference plane and decoding characters on information area. This research contributes to narrow the scope of a particular letter and to read the controversial letters on the Pohang Jungsoengri Silla Stone Monument(Korea's national treasure number 318).