• Archives of Craniofacial Surgery
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• v.25 no.3
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• pp.133-140
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• 2024

Background: The medial canthal region features a complex three-dimensional and internal anatomical structure. When reconstructing a defect in this area, it is crucial to consider both functional and aesthetic aspects, which presents significant challenges. Generally, local flaps are preferred for reconstruction; however, skin grafts can be used when local flaps are not feasible. Therefore, we conducted a comparative analysis of surgical outcomes skin grafts when local flaps were not feasible, to determine which surgical method is more effective for medial canthal region reconstruction. Methods: Twenty-five patients who underwent medial canthal region reconstruction using skin grafts or local flaps from 2002 to 2021 were enrolled. Patient information was obtained from medical records. Five plastic surgeons evaluated the surgical outcomes based on general appearance, color, contour, and symmetry. Results: Skin grafts were used in eight patients and local flaps were used in 13. Combined reconstructions were employed in four cases. Minor complications arose in four cases but improved with conservative treatment. No major complications were reported. Recurrence of the skin cancer was noted in two cases. All categories showed higher scores for the local flap compared to both skin graft and combined reconstruction; however, the differences were not statistically significant respectively. Conclusion: The choice of appropriate surgical methods for reconstructing defects in the medial canthal region depends on various factors, including the patient's overall health, the size and depth of the defect, and the degree of involvement of surrounding structures. When a local flap is not feasible, a skin graft may provide favorable surgical outcomes. Therefore, a skin graft can serve as a viable alternative for reconstructing the medial canthal region.

• Journal of ILASS-Korea
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• v.20 no.2
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• pp.107-113
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• 2015

To date, the demand for Combined Cycle Power Plant (CCPP) has been continuously increased to overcome the problem of air pollution and lack of energy. In particular, the underground CCPP is exposed to substantial fire and explosion risks induced by gas leakage. The present study conducted numerical simulations to examine the fire behavior and gas leakage characteristics for a restricted region including gas turbine and other components used in a typical CCPP system. The commercial code of FLUENT V.14 was used for simulation. From the results, it was found that flammable limit distribution of leakage gas affects fire behavior. Especially, the flame is propagated in an instant in restricted region with LNG gas. In addition, consequence analysis factors such as critical temperature and radiation heat flux are introduced. These results would be useful in making the safety guidelines for the underground CCPP.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.3
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• pp.302-310
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• 2003

Experiments were conducted to show the characteristics of the flow on unventilated parallel plane jets. Measurements of mean velocity components and turbulent intensities were carried out with a particle image velocimetry to investigate the flow field generated by the air issued from two identical plane parallel nozzles and mixed with the ambient air. The measurements range of these experiments were Reynolds number of 5300 based on the nozzle width and the cases of nozzle-to-nozzle distance were four times. six times and eight times the width of the nozzle. Results show that a recirculation zone with a sub-atmospheric static pressure was bounded by the inner shear layers of the individual jets and the nozzles plate. The positions. where maximum value of mean turbulent intensities and mean turbulent kinetic energy show, were at the same position with the merging point. The spread of jets in the merging region increases more rapidly than that of Jets in the converging and the combined region. As nozzle-to-nozzle distances were increased. it was shown that merging and combined lengths were shorter.

• Journal of Periodontal and Implant Science
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• v.38 no.sup2
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• pp.405-412
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• 2008

Purpose: Pathologic tooth migration (PTM) commonly occurs in the anterior region and is associated with periodontal disease. The treatment of PTM of anterior teeth can be complex and time consuming, and a multidisciplinary approach is often required. Materials and Methods: The patient was a 38-year-old woman with a chief complaint of saving and realigning her elongated maxillary left central incisor. This paper describes the successful combined periodontal regenerative (guided tissue regeneration) and prosthetic treatment and a 2-year follow-up of maxillary central incisor with pathologic tooth migration, deep intrabony defect, and poor prognosis. Results: The right maxillary central incisor was restored by laminate veneer and the left by all-ceramic crown. The patient had no pain and discomfort and was satisfied with the outcomes of her treatment for 2 years. She has maintained her recall program at the Department of Periodontology at 3 months interval. Conclusion: The key step in the successful treatment of PTM in anterior region is to obtain a high level of cooperation from the patient. Maintenance of the treatment result of PTM is dependent on the continuous preservation of periodontal health.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.1
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• pp.9-14
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• 2000

When current flows through a thick conductor such, most of the current flows along outside of the conductor, which is called skin effect. This paper represents a method calculating such a current distribution in the conductor region. The conductor region is divided into some pieces and each piece has its own unknown variable, i.e. current density. The governing equation which expresses Maxwell's equation is combined with the circuit equation with voltage source. The combined equation is solved to obtain current distribution in the conductor. This algorithm is applied to EMC(Electromagnetic Casting) to calculate current density with voltage source.

• Coupled systems mechanics
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• v.4 no.2
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• pp.115-136
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• 2015

We present for one-dimensional model for elastoplastic bar with combined hardening in FPZ - fracture process zone and softening with embedded strong discontinuities. The simplified version of the model without FPZ is directly compared and validated against analytical solution of Bazant and Belytschko (1985). It is shown that deformation localizes in an area which is governed by the chosen element size and therefore causes mesh sensitivity and that the length of the strain-softening region tends to localize into a point, which also agrees with results obtained by stability analysis for static case. Strain increases in the softening domain with a simultaneous decrease of stress. The problem unloads elastically outside the strain-softening region. The more general case with FPZ leads to more interesting results that also account for induced strain heterogeneities.

• ETRI Journal
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• v.44 no.4
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• pp.624-640
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• 2022

Taxi-demand forecasting and hotspot prediction can be critical in reducing response times and designing a cost effective online taxi-booking model. Taxi demand in a region can be predicted by considering the past demand accumulated in that region over a span of time. However, other covariates-like neighborhood influence, sociodemographic parameters, and point-of-interest data-may also influence the spatiotemporal variation of demand. To study the effects of these covariates, in this paper, we propose three models that consider different covariates in order to select a set of independent variables. These models predict taxi demand in spatial units for a given temporal resolution using linear and ensemble regression. We eventually combine the characteristics (covariates) of each of these models to propose a robust forecasting framework which we call the combined covariates model (CCM). Experimental results show that the CCM performs better than the other models proposed in this paper.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.2 s.233
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• pp.214-223
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• 2005

The characteristics of flow on two parallel plane jets was experimentally investigated. The two nozzles each with an aspect ratio of 20 were separated by 6 nozzle widths. Reynolds number based on nozzle width was set to 5,000 by nozzle exit velocity. The particle image velocimetry and pressure transducer were employed to measure turbulent velocity components and mean static pressure, respectively. In case of unventilated parallel plane jets, it was shown that a recirculation zone with sub-atmospheric static pressure was bounded by the inner shear layers of the individual jets and the nozzles plated. There was no recirculation zone in the ventilated parallel plane jets. It was found that the spanwise turbulent intensities of unventilated jets were higher than those of ventilated jets because of the interaction of jets, and the streamwise turbulent intensities of ventilated jets were higher than those of unventilated jets because of the effect of entrainment.

• Nuclear Engineering and Technology
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• v.29 no.3
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• pp.201-210
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• 1997

A thermal conductivity correlation has been proposed which can be applied to high turnup fuel by considering both of thermal conductivity with turnup across fuel pellet and additional degradation at pellet rim due to very high porosity. In addition, a correlation has been developed that can estimate the porosity of rim region as a function of rim burnup under the assumptions that all the produced fission gases are retained in the in porosity and threshold pellet average burnup required for the formation of rim region is 40 MWD/㎏U. Rim width is correlated to rim burnup using measured data. For the RISO experimental data obtained at pellet average turnup of 43.5 MWD/㎏U for three linear heat generation rates of 30, 35 and 40 ㎾/m, radial temperature distributions ore calculated using the present correlation and compared with the measured ones. This comparison shows that the present correlation gives the best agreement with the measured data when it is combined with the HALDEN's correlation for thermal conductivity considering its degradation with burnup. Another comparison with the HALDEN's measured fuel centerline temperature as a function of burnup at 25 ㎾/m up to about 44 MWD/㎾U also suggest that the present correlation yields the best agreement when it is combined with the HALDEN's thermal conductivity.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2144-2146
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• 2000

In this research, a ozone generation using a combined discharge method, in which a surface and a silent discharges are occur in discharge region simultaneously, is investigated experimentally. On our experiments, the combined discharge was confirmed, and the characteristics of the ozone generation were obtained. In this paper, the typical results about the ozone generation are described.