• ETRI Journal
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• v.31 no.1
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• pp.71-73
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• 2009

In this letter, novel antennas with two spiral elements are presented for ultra-wideband application. The original antenna consists of a T-shaped microstrip feed line, two spiral radiating elements, and a ground plane with two circular slots. It measures 30 mm ${\times}$ 40 mm ${\times}$ 1.6 mm. Spiral elements are used to increase the lower bandwidth limit. To further reduce the size of the antenna, the original antenna is cut in half by using the symmetry of the surface current distributions. The proposed antennas feature omnidirectional radiation patterns and good gain flatness.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.3
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• pp.147-158
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• 1997

This paper presents the analysis technique and procedure of main engine components-cylinder block, cylinder liners, gasket and cylinder head-using the finite element method, which aims to assess mainly the potential of lower oil consumption in a view point of engine design and to decide subsequently the accuracy of engine design which was done. The F.E. model of an engine section consisting of one whole cylinder and two adjacent half cylinders is used, whereby the crankcase is cut off at the block bottom deck. By means of a 3-dimensional F.E. model-including cylinder block, liners, gasket, cylinder head, bolts and valve seat rings as separate parts a linear analysis of deformations and stresses was performed for three different loading conditions;assembly, thermal and gas loads. For the analysis of thermal boundary conditions also the temperature field had to be evaluated in a subsequent step.

• The Research Journal of the Costume Culture
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• v.7 no.5
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• pp.56-67
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• 1999

At the turn of the 19C, the first development, spreading to the all classes that peculiar attitude of mind associated with the term prudery. The second changes of habit which affected both sexes and their undergarments were the novel idea of personal cleanliness. Drawers appear to have been of two lengths, short, when worn under breeches, and long when worn under pantaloons and trousers. The dandy wore corsets for beauty. In the early part of the 19C, the differences between day and evening style came to be accentuated. Not only the beau, but the soldier and hunting man were addicted to stays. The high standing collars of the early 1800s became fairly low in the middle of the century. in mid of the 19C, a woolen under-vest was worn next to the skin and studs were an usual fashion. At about 1850 the bottom of the shirt was cut in a curve. For evening dress the elliptic collar was introduced.

• The Research Journal of the Costume Culture
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• v.8 no.5
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• pp.638-647
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• 2000

The purpose of this study is to discover the interrelationship between modern costumes and Seung-Hee Choi's dancing costumes in 1930s. Seung-Hee Choi, who was a dancing pioneer in Korea, introduced the modern dancing costumes for the first time in Korea. The results are as followed ; First, we can find Eroticism in Choi's dancing dress. Choi's dancing costume had used gold thread, silver thread, spangle, see-through and a half-naked body clothing that decorated with beads and cords. It is similar to modern costumes in ubjet mtter, silhouette, design, and so on. Second, the influence of Futurism was in her dancing costumes, that is, it represented asymmetry designs and rectilineal figures. Third, not only beauty but also a Functionalism was expressed in her dancing costumes. Functional beauty was shown through bias cut, pleats, slit, and so on.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.615-615
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• 2003

I. Objectives This study was performed to get some information about micromorphology of subsurface lesion of root caries by observing autofluorescence using confocal laser scanning microscope(CLSM) with minimum sample preparation. II. Materials and Methods Half-cut and 1 mm thick sample of human teeth were prepared to produce artificial root carious lesions. Incipient subsurface lesions were produced under optimal pH and saturity. The lesions were observed by polarized microscopy, CLSM, and back-scattered electron microscope(BSE). Calcium and phosphorus concentrations of the lesions were analyzed by line EDAX. (omitted)

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.9
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• pp.48-56
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• 2021

Tungsten carbide (WC) circular saws have been widely used to cut plywood. Recently, expensive polycrystalline diamond (PCD) were adopted to extend the tool life of circular saws. This study developed a PCD-WC combination circular saw and compared its performance with that of existing WC and PCD saws. Flank wear of WC saw blades and edge chipping of rectangular PCD was observed during the experiments. The PCD-WC saw replaced half of the chamfered teeth with PCD and applied tough WC for all rectangular teeth. In the experiments, edge chipping was not observed in rectangular WC teeth and the flank wear of chamfered teeth was decreased compared with that of conventional circular saws.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.11
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• pp.1510-1519
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• 2007

This comparative study analyzes and compares tight skirt sewing methods which are found in the clothing configuration reference text books available in contemporary universities and which are used in commercially-available domestic consumer products. The study samples included 15 text books and 12 tight skirt consumer products of different brands on sale at three department stores in Seoul each of which had a belt, a back-centered zipper, and back double slits. The findings of the study are summarized as follows: First, text books mainly show very basic sewing methods of using zippers on both sides of the straight-lined waist belt. This indicates that it is necessary for such methods to be complemented so that they cover a recent variety of designs, materials, and sewing machines. For consumer products, the main sewing method is to use a curved waist belt and a console zipper in silhouette running across half the hipbone. Second, consumer products employ three different types of cutting and sewing methods for putting an inseam on the center of the back slit part: to leave the whole inseam hemmed in the back center, to cut the left side of the inseam to the upper part of the back slit, and to cut the inseam to both the upper parts of the back slit. However, a method shown in most of the sampled text books is to cut the inseam of the back center to both the upper parts of the back slit. Third, the way of finishing a bottom edge hem in the text books is to do slip-stitch, herringbone stitch, and slinting hemming, in order after doing over-lock stitch, or to cut the hem on the bias and then slip-stitch, while for the consumer products the most frequently used sewing method is to finish the bottom edge hem by doing secoui-stitch. Finally, while in the text books the method of stitching darts and tucks is used for lining, the main lining method used in consumer products is to make tucks only. Also in the way of stitching the side seams of lining or the seams of the back center, there is a difference between the two sample groups of text books and the consumer products: while the former suggests using both open seams and over-lock stitch, the latter is found to finish the seams using an over-lock stitch only.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.5
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• pp.82-90
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• 2018

The nuclear structures are composed of large diameter bars over No.36. If the hooked bars are used for anchorage of large diameter bars, too long length of the tail extension of the hook plus bend create congestion and make an element difficult to construct. To address those problems, headed bars were developed. Provisions of ACI 318-08 specify the development length of headed bars and ignore the effect of transverse reinforcement based on the background researches. However, if headed bars are used at the cut-off or lap splice, longitudinal reinforcements, which are deformed in flexural members, induce tensile stress in cover concrete and increase the tensile force in the transverse reinforcement. The object of this research is to evaluate the effects of transverse reinforcement on the anchorage capacity of headed bar so anchorage test with variable of transverse rebar spacing was conducted. Specimens, which can consider the behavior at the cut-off, were tested. Test results show that failure of specimen without transverse reinforcement was sudden and brittle with concrete cover lifted and developed stress of headed bars was less than half of yield strength of headed bars. On the other hand, in the specimen with transverse reinforcement, transverse rebar directly resist the load of free-end so capacity of specimens highly increased.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.270-277
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• 2021

Veronica rotunda var. subintegra (Nakai) T. Yamaz. is perennial herb belonging to the family Scrophulariaceae, native to Korea. Plant growth regulators, cutting mediums, cutting position, and leaf size were examined to investigate the requirements for cutting propagation of V. rotunda var. subintegra. This study was conducted over a period of 6 weeks from March to May 2017 in the Division of Plant Resources, Korea National Arboretum. For all treatments, survival and rooting percentage was 100%. In PGRs experiment, the number of roots and shoot length treated with 100 mg/L IBA treatment was significantly higher than that of NAA treatment. The shooting percentage was decreased with an increase of the PGRs concentration. In growing substrates experiment, the number of roots on commercial soil (61.2) was the highest, followed commercial + kanuma soil (45.7), and the lowest was kanuma soil (41.8). The shoot length treated with commercial soil (8.9 cm) was significantly greater than that of kanuma soil (4.1 cm). In cutting positions experiment, the number of roots treated with apical (56.6) was significantly higher than that of basal (38.8). In leaf-cut experiment, the number of roots and of shoot length treated with full leaf was significantly higher than that of half leaf. As a result, we recommend treating cuttings with 100 mg/L IBA treatment, commercial soil, apical position, and full leaf for successful cutting propagation of V. rotunda var. subintegra.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.2
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• pp.104-111
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• 2020

Purpose: The purpose of this study is comparing the efficiency of debris removal of passive ultrasonic irrigation depend on different protocols. Materials and Methods: Forty-eight mandibular premolars were randomly divided into 2 groups depend on vibration power (Weak and Strong, n = 24). And then two groups were subdivided into 3 groups depend on the number of times that PUI used (1, 2 and 3, n = 8). After standardization, teeth were split into two halves. On the wall of one half of root canal, three depressions were cut at 1, 3 and 5 mm from the apex and in the same way two depressions were cut on the other half of root canal at 2, 4 mm from the apex. Each depression was filled with mixture of dentine and NaOCl. After irrigation, images of the root canal wall were taken, and then the amount of remaining dentine debris was evaluated. Results: There was no significant difference between weak and strong power of vibration groups. Weak vibration groups did not show significant difference depend on the different number of times PUI used. But in the strong vibration groups, twice and three times used groups show better removal efficiency. Conclusion: The removal efficiency of dentine debris is not significantly different depend on the power of vibration. And multiple use of PUI could have better irrigating effects at the apical third area in the strong vibration group.