• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.1
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• pp.155-161
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• 2005

Nonlinear electronic loads used at office buildings distort the voltage and current waveform that cause the overheating of transformer losses, ELB(Electrical Leakage Breaker) tripping, and so on. This paper analyzed waveform distortion characteristics at several once buildings by comparing with magnitude of voltage and current harmonics, crest factor of voltage and current, phase voltage and current unbalance. As a consequence, severe current waveform distortion in phase and neutral line by harmonics and high current unbalance rates by unbalanced using of single loads among the three phases are investigated. The results of the study can be used in making decisions regarding reasonable and economical operating of loads at office buildings.

• Journal of the Korean GEO-environmental Society
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• v.13 no.3
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• pp.13-19
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• 2012

Due to recent climate change, big typhoon and heavy rainfall happen frequently not only in Korea but also all over the world. It leads to collapse of levee by extraordinary flood. It lead to collapse of levees by extraordinary flood. These natural disasters give the life and property damages in near region. In this study, it was performed that a stability in levee using seepage analysis. It has been evaluated hydraulic gradient of exit zone according to variations in levee crest width, gradient. As a result, it showed that hydraulic gradient of exit zone was decreased due to increase of levee crest width and gradient, and it was evaluated that vertical hydraulic gradient was decreased than that of the horizontal hydraulic gradient.

• The Journal of Korean Academy of Prosthodontics
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• v.23 no.1
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• pp.97-112
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• 1985

The purpose of this study was to evaluate the stress patterns developed in supporting structures by removable partial denture with attachment retainers. The attachments tested were Dalbo(miniature) attachment, resilient Ceka attachment, rigid Ceka attachment, precision and sleeve attachment, and R.P.I. clasp as a contrast. 3-dimensional photoelastic stress analysis was used to record the isochromatic and isoclinic fringe patterns and to calculate principal stress components at measuring points. The results showed that: 1. The maximum compressive stress on residual ridge was produced under the loading point with Dalbo and resilient Ceka attachment, distal to the loading point with rigid Ceka and precision and sleeve attachment, and mesial to the loading point with R.P.I. clasp. 2. The Dalbo attachment produced the most stress on residual ridge, and the least stress on abutment teeth. and resilient Ceka attachment showed favorable stress distribution. 3. Rigid Ceka attachment produced higher compressive stress on buccal. alveolar crest, and precision and sleeve attachment produced higher compressive stress on distal alvelolar crest and mesial surface of the root apex in abutment teeth. 4. R.P.I. clasp produced higher compressive stress on mesial alveolar crest.

• Molecules and Cells
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• v.19 no.3
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• pp.310-317
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• 2005

The Xenopus FGF-8a and FGF-8b isoforms have been reported to be neural crest and neuronal inducers, respectively. However, cloning of Xenopus FGF-8b (XFGF-8b) has not been reported previously and the two isoforms do not seem to have been clearly distinguished in Xenopus experiments. Here, we describe the cloning and expression of XFGF-8b and compare the effects of the two isoforms. XFGF-8b has an 11 amino acid insert in its N-terminal region compared with XFGF-8a. Both isoforms are expressed in the anterior neural regions of the early embryo, and in the apical ectodermal ridge of limb buds and tips of growing digits in the larval stages. However, XFGF-8b is more abundant than XFGF-8a throughout early development. The two isoforms are also regulated in similar fashion by retinoic acid in early development. However, although both XFGF-8a and XFGF-8b induce ectopic neurogenesis, only XFGF-8a appears to be involved in neural crest induction.

• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.4
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• pp.57-62
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• 2002

The present study deals with turbulent flow over a long train of fixed two-dimensional dunes, identical in size and shape. A detailed study was carried out by PIV over a range of flow depths in a fully developed region. The present study confirmed the global features of flow past a fired dune noticed in previous studies, i.e. the size and shape of the reverse flow, the mean velocity and turbulence profiles across the separated and attached flows. The turbulence and shear stress profiles reveal the presence of larger values along the line extending from crest to crest. At stations ahead of the dune crest, the presence of a peak in the streamwise turbulence profiles around y/h = 2 indicates the sustenance of turbulence generated in the separation zone of the previous zone which will be carried over to the next dune.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.3
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• pp.299-302
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• 1999

$La_{2-x}Sr_{x}CuO_{4}$ single-crystalline films were prepared on bulk single crystals of Zn-doped $La_{2-x}Sr_{x}CuO_{4}$ as the substrates by LPE technique using two deferent methods. When prepared using an alumina crucible in normal electrical furnace, the $La_{2-x}Sr_{x}CuO_{4}$ films were contaminated with less than 3 at% aluminum from the alumina crucibles. Aluminum contamination either reduced or completely destroyed the superconductivity of the $La_{2-x}Sr_{x}CuO_{4}$ films, For LPE growth by modified TSFZ method using an infrared heating furnace without crucibles, the $La_{2-x}Sr_{x}CuO_{4}$ films of x=0.11 showed superconducting with $Tc_{onset}=36\;K$, which is 10 K higher than that in the $La_{2-x}Sr_{x}CuO_{4}$ bulk single crystals.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.3
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• pp.611-619
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• 1996

The purpose of this study was to evaluate the fitness of 4 kinds of resin record base materials. The record base materials used on the edentulous cast in this study were Triad VLC resin (Dentsply International Inc., U.S.A.), custom tray resin (Kerr Ltd., U.S.A.), heat-cure resin (Dentimex Co., Holland), and self-cure resin (Dentimex Co., Holland). The gap width between record base and cast were measured in the ridge crest and midpalatal area with microhardness tester. The results obtained were as follows : 1. Among the 4 kinds of record base, heat-cure Vertex fitted best on the cast. Triad and Fomatray fitted better than self-cure Vertex. Self-cure Vertex had the poorest fit. 2. The quality of the fit of the record base varied at different locations on the cast. The record base fit better in the ridge crest than midpalatal area. 3. In the midpalatal area, there's no significant difference in the fit of Fomatray, Triad and heat-cure Vertex. They all fit better than self-cure Vertex. 4. In the ridge crest, heat-cure Vertex fit better than any other record base.

• The Korean Journal of Pain
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• v.6 no.1
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• pp.83-95
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• 1993

In out-patient clinic, it seems to be common that most back pain arise from muscular origins rather than from skeletal origins. Most physicians have wished to diagnose lower back pain from the radiologic findings only. From clinical experiences and anatomical studies, I have gotten a different opinion from common sense about backaches. If I met a patient who had lower back pain around the posterior superior iliac crest(P.S.I.C.) area, I would had to search a trigger point in the erector spinae muscles at the level of thoraco-lumber junction rather than at the level of the painful site. It is why that sensory innervation over the posterior superior iliac crest area is the posterior primary branch of T12 spinal nerve running down through the erector spinae muscles. Pain on the iliac crest area is supposedly due to hyperirritability of the sensory nerve distributing to this area. Hyperirritability of the posterior primary branch of $T_{12}$ spinal nerve may be due to the spasm of the longissimus thoracis muscle in the erector spinae muscles at the level of the thoraco-lumbar junction. So finally, I would like to insist that spasmolytic treatment on the muscle at the level of the thoraco-lumbar junction would be better for pain relief around P.S.I.C. than treatment at the painful site only.

• Molecules and Cells
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• v.37 no.1
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• pp.59-65
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• 2014

Eph receptors and their ligands ephrins have been implicated in guiding the directed migration of neural crest cells (NCCs). In this study, we found that Wnt1-Cre-mediated expression of ephrinA5-Fc along the dorsal midline of the dien- and mesencephalon resulted in severe craniofacial malformation of mouse embryo. Interestingly, expression of cephalic NCC markers decreased significantly in the frontonasal process and branchial arches 1 and 2, which are target areas for the migratory cephalic NCCs originating in the dien- and mesencephalon. In addition, these craniofacial tissues were much smaller in mutant embryos expressing ephrinA5-Fc. Importantly, EphA7-positive cephalic NCCs were absent along the dorsal dien- and mesencephalon of mutant embryos expressing ephrinA5-Fc, suggesting that the generation of cephalic NCCs is disrupted due to ephrinA5-Fc expression. NCC explant experiments suggested that ephrinA5-Fc perturbed survival of cephalic NCC precursors in the dorsal midline tissue rather than affecting their migratory capacity, which was consistent with our previous report that expression of ephrinA5-Fc in the dorsal midline is responsible for severe neuroepithelial cell apoptotic death. Taken together, our findings strongly suggest that expression of ephrinA5-Fc decreases a population of cephalic NCC precursors in the dorsal midline of the dien- and mesencephalon, thereby disrupting craniofacial development in the mouse embryos.

• Journal of The Geomorphological Association of Korea
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• v.23 no.3
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• pp.13-25
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• 2016

The purpose of this study is to investigate the location characteristics in which 'large Jar coffin' (hereinafter referred to as 'Jar coffin') distributed in the Yeongsan river basin area in Jeonnam province by means of topographic analysis. 75 Jar coffins (74.3%) in 19 relics (90.5% of total) were found in hill and 26 Jar coffins (25.7%) of two consumption relics (9.5%) were found in floodplain. Among them, 34 (45.3% of total) and 41 (54.7% of total) Jar coffins were found in the Crest surface and Sideslope of hills, respectively. In particular, 26 (34.7%) Jar coffins are mostly located in the Crest flat. This result implies that people at that might be consider the river inundation, and mostly choose hill rather than floodplain when building the Jar coffin. therefore amongtherefore among micro-landform units of the hill, it seems that the 'Crest flat' was the preferred place for the building the Jar coffin at that time.