• The Journal of Korea Assosiation for Disability and Oral Health
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• v.4 no.1
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• pp.12-16
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• 2008

Williams syndrome is a rare genetic disorder with a frequency of one per 20,000~50,000 live births. It is caused by a deletion of one elastin allele located within chromosome subunit 7q11.23(long arm). This syndrome is frequently accompanied by disorders such as congenital heart disease, facial anomalies, mental retardation, and so on. The characteristic facial appearance includes full lips, rounded cheeks, broad forehead, periorbital fullness, flattened bridge of nose, small nose with anteverted nostril, long filtrum and low-set ears. In oral features, hypodontia, high prevalence of dental caries, microdontia, enamel hypoplasia, delayed eruption, and malocclusions have been found. Most adult patients with Williams syndrome lack social adaptability and lead seclusive lives, however, young patients are rather very friendly and talkative, and seem smarter than their actual intellectual quotients. They also tend to favor staying with grown-ups rather than mixing with their peers, and tend to present problematic temper tantrum during dental treatment.

• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.109-116
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• 2010

This study is intended to propose a technique that can trace objects by utilizing the multimarker method in the Marker Recognition which is a bridge way connecting virtuality and reality in complex environments or in a condition hands become obstacles. In the existing marker method, the object becomes blinking when the maker is blocked since this method relies only on single marker. However, the researcher was able to confirm the appearance of augmented object when the marker was blocked for the multiple markers replaced the blocked one. In order to implement such technique, multi-marker estimation was utilized with perspective matrix. The advantage is the fast estimation process for there is no need of other calculation. The implemented technique can detect markers and locate their positions, represent 3-D object in various circumstances.

• Journal of the Korean earth science society
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• v.23 no.1
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• pp.52-58
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• 2002

A colorless and transparent zirconium oxide ($Zr_{0.73}Y_{0.27}O_{1.87}$) crystal has been synthesized by the Bridgman-Stockbager method. The gem-quality material is produced by adding 20${\sim}$25 wt.% $Y_2O_3$ (stabilizer) and 0.04 wt.% $Nd_2O_3$ (decolorising agent) to the $ZrO_2$ powder. It shows a vitreous luster with a slight oily appearance. Under a polarizing microscope, it shows isotropic nature with no appreciable anisotropism. Mohs hardness value and specific gravity is measured to be 8${\sim}$$8{\frac{1}{2}}$ and 5.85, respectively. Under ultraviolet light it shows a faint white glow. The crystal structure of yttria-stabilized zirconia with 0.27 at.% Y has been re-investigated, using single crystal X-ray diffraction, and confirmed to be a cubic symmetry, space group $Fm{\overline{3}}m$ ($O^5_h$) with a=5.1552(5) ${{\AA}}$, V=136.99(5) ${{\AA}}^3$, Z=4. The stabilizer atoms randomly occupy the zirconium sites and there are displacements of oxygen atoms with amplitudes of ${\Delta}/a{\sim}$0.033 and 0.11 along <110> and <111> from the ideal positions of the fluorite structure, respectively.

• Journal of Advanced Marine Engineering and Technology
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• v.12 no.3
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• pp.57-67
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• 1988

Although handicapped by the inability to bridge the size gap between small laboratory sample and large engineering component, the V charpy test sample method does possess certain advantages, such as each of preparation, simplicity of test method, speed, low cost in test machinery, and low cost per test. On the other hand, the COD test method does posses advantages, which reduce the size gap between the laboratory sample and actual engineering component. Consequently, the correlation between V charpy absorbed energy and the critical COD value is required for estimating critical COD value from the simple V charpy test results. In this paper, the high tensile strength steel AH36 plate specimens having a single edge cracked notch were investigated to find out the correlation between V charpy absorbed energy and critical COD value in the welded parts under such various welding methods as shielded metal arc welding, the submerged arc welding and the electro gas welding by means of V charpy impact test and static 3-point bending test. Main results obtained are as follow ; 1. The relationships between V charpy absorbed energy Wc' and critical COD value ($\delta_c$)show; $\delta_c$=0.0065 Wc'+0.1906. 2. Ductile- brittle transition behaviours can be estimated by means of fracture appearance and general yielding behaviours. 3. The V charpy absorbed energy of SMAW is higher than that of SAW, EGW and similar relationships are obtained in the COD tests.

• The Research Journal of the Costume Culture
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• v.25 no.6
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• pp.719-740
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• 2017

Sociocultural and demographic shifts have resulted in a changing perception of older age. Older women, historically subjected to age-ordering rules of dress, have increasingly refused to be marginalized fashion consumers and have been striving to construct a more positive age identity. Although studies have examined consumers' negotiation of marginalized identities, age identity has not received much attention as a type of marginalized identity. This study argues that Pinterest acts as a platform for identity work by allowing older women to creatively reconstruct their sense of self by saving images and organizing them into thematic boards. Drawing on symbolic interactionism theory and notions of digital self-presentation, this paper seeks to explore the discursive practices that older women employ on Pinterest to resist ageist fashion discourses. The sample consisted of 15 fashion-oriented Pinterest profiles of older women. Netnographic inquiry was employed first to examine what images were saved and what thematic boards were created. Three analytical frameworks for visual data analysis were integrated to further scrutinize the visual texts within the thematic boards. The analyses revealed three main themes-rejecting age, accepting age, and consuming age. The themes that emerged formed the basis for an age identity reconstruction process whereby women attempted to bridge the existing gap between older age and mainstream fashion discourse.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.7
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• pp.452-461
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• 2004

A novel multilevel PWM inverter is presented for the use of stand-alone photovoltaic power generation system. In appearance, it consists of three full-bridge modules and three cascaded transformers; therefore, the configuration of the proposed multilevel PW inverter is equal to that of a prior 11-level PWM inverter. Only the turn-ratio of a transformer and its corresponding switching function are different from each other. Owing to these differences, the proposed 19-level PWM inverter has two promising advantages. First, output voltage levels increase almost twofold. Consequently, it can generate more sinusoidal output voltage waveform. Second, due to a revised switching pattern, it lightens power imposed on the transformer, which is used for compensating output voltages with chopped pulses between steps. The validity of the proposed inverter system is verified by computer-aided simulations and experimental results based on a 1 ［kW］ prototype. The performance of the proposed 19-level PWM inverter is compared with the Prior 11-level PWM inverter and other counterparts.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.45.1-45.1
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• 2020

Light bridges (LBs) are relatively bright structures that divide sunspot umbrae into two or more parts. Chromospheric LBs are known to be associated with various activities including fan-shaped jet-like ejections and brightenings. Although magnetic reconnection is frequently suggested to be responsible for such activities, not many studies presented firm evidence to support the scenario. We carry out magnetic field measurements and imaging spectroscopy of a LB where fan-shaped jet-like ejections occur with co-spatial brightenings at their footpoints. We study their fine photospheric structures and magnetic field changes using TiO images, Near-InfraRed Imaging Spectropolarimeter data, and Hα data taken by the 1.6 m Goode Solar Telescope. As a result, we detect magnetic flux emergence in the LB that is of opposite polarity to that of the sunspot. The new flux cancels with the pre-existing flux at a rate of 5.6×1018 Mx hr-1. Both recurrent jet-like ejections and their footpoint brightenings are initiated at the vicinity of the magnetic cancellation, and show apparent horizontal extension along the LB at a projected speed of 4.3 km s-1 to form the fan-shaped appearance. Based on these observations, we suggest that the fan-shaped ejections may have resulted due to slipping reconnection between the new flux emerging in the LB and the ambient sunspot field.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3A
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• pp.201-209
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• 2010

Generally, PSC girder bridge uses total gross cross section to resist applied loads unlike reinforced concrete member. Also, it is used as short and middle span (less than 30 m) bridges due to advantages such as ease of design and construction, reduction of cost, and convenience of maintenance. But, due to recent increased public interests for environmental friendly and appearance appealing bridges all over the world, the demands for longer span bridges have been continuously increasing. This trend is shown not only in ordinary long span bridge types such as cable supported bridges but also in PSC girder bridges. In order to meet the increasing demands for new type of long span bridges, PSC hollow box girder with H-type steel as compression reinforcements is developed for bridge with a single span of more than 50 m. The developed PSC girder applies compressive prestressing at H-type compression reinforcements using unbonded PS tendon. The purpose of compressive prestressing is to recover plastic displacement of PSC girder after long term service by releasing the prestressing. The static test composed of 4 different stages in 3-point bending test is performed to verify safety of the bridge. First stage loading is applied until tensile cracks form. Then in second stage, the load is removed and the girder is unloaded. In third stage, after removal of loading, recovery of remaining plastic deformation is verified as the compressive prestressing is removed at H-type reinforcements. Then, in fourth stage, loading is continued until the girder fails. The experimental results showed that the first crack occurs at 1,615 kN with a corresponding displacement of 187.0 mm. The introduction of the additional compressive stress in the lower part of the girder from the removal of unbonded compressive prestressing of the H-type steel showed a capacity improvement of about 60% (7.7 mm) recovery of the residual deformation (18.7 mm) that occurred from load increase. By using prestressed H-type steel as compression reinforcements in the upper part of cross section, repair and rehabilitation of PSC girders are relatively easy, and the cost of maintenance is expected to decrease.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.3
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• pp.313-319
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• 2016

Wolf-Hirschhorn syndrome (WHS), associated with the deletion of the short arm of chromosome 4, causes multiple congenital malformations. Patients suffer from various deformities, including mental and growth disorders, epilepsy, hypotonia, congenital heart defects, and atypical craniofacial features. The "Greek warrior helmet appearance" is the most characteristic feature, with a prominent glabella, high arched eyebrow, broad nasal bridge, and hypertelorism. Cleft lip with or without cleft palate is observed in 30% of patients. Dental structure anomalies also exist including multiple tooth agenesis and over-retained primary molars caused by MSX1 gene impairment, and cone-shaped and taurodontic teeth. This case, a 9-year-old girl with WHS, showed intellectual disability, delayed growth development, previous occurrence of seizures, otitis media, and the typical facial features of WHS. Dental findings included multiple congenital missing teeth, over-retained primary teeth, and severe caries on the primary molars. Dental treatments were performed under general anesthesia. This report documents the characteristics of WHS, including general and oral features, and discusses the importance of oral hygiene and preventive dental management.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.1 no.2
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• pp.1-8
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• 2000

An attempt was made to develop commercially pure titanium frames of glasses with a high-precision laser beam welding machine, in which a resonator with 12kw of the peak power and 200 W of maximum mean power has the capacity of variable in the range of 0.08~10 ms pulse width. In addition the optical fiber beam transmission with 400 ${\mu}{\textrm}{m}$ of the core diameter and a weld chamber to contain specimens in the inert gas atmosphere were also designed and used. In the present study. titanium frames of glasses parts such as temple plus spring hinge. bridge and top bar were experimentally manufactured by utilizing the optimum welding parameters with the optical fiber of GI 400 ${\mu}{\textrm}{m}$, 2.9J energy per pulse, and focussing position for Tee and butt joints. The titanium welded joints with laser beam welding did not reveal any severe weld defects or weld bead appearance except some pores in the weld section.