• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.3
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• pp.414-426
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• 1997

Numerical computations were conducted to characterize the three-dimensional laminar flow through an injector orifice having an inclined angle of 30 .deg.. For this study, the incompressible Navier-Stokes equations in generalized curvilinear coordinates, using a pseudocompressibility approach for continuity equation, were solved. The computations were performed using the finite difference implicit, approximately factored scheme of Beam and Warming and multi-block grids of complete continuity at block interfaces. The multi-block computations were validated for the steady state using direct comparison of multi-block solutions with equivalent single-block ones, including 2-D 180.deg. TAD and 3-D 90.deg. pipe bend. The comparisons between the numerical solutions and the flow field measurements for a tube with sudden contraction were presented in this work for solution validation. Computational results showed the nature of complex flow fields within the inclined injector orifice, including strong pressure-driven secondary flows in the cross stream induced by the effect of streamline curvature. In addition, asymmetric secondary flows were induced in the Reynolds number range above assumed laminar flow regime considered. However, turbulence calculations and grid dependency studies are needed for more accurate computations.

• Journal of Life Science
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• v.11 no.3
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• pp.279-283
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• 2001

Amyotrophic lateral sclerosis(ALS) is a progressive neurologic disorder resulting from the degeneration of upper and lower motor neurons, and is inherited in 10% of cases. About 20% of familial ALS, clinically indistinguishable from sporadic ALS, is caused by mutations of Cu/Zn superoxide dismutase on chromosome 21q22.21 inherited as an autosomal dominant trait. We now report a new locus in the non-SOD1 dominantly inherited ALS. We screened a large ALS family with 11 affected individuals and one obligate gene carrier with genome-wide ABI polymorphic markers using the ABI 377 automated system. No evidence of linkage was obtained with the autosomal markers. We next screened this family with X chromosome markers as there was no evidence of male-to-male tran-smission of the disease. Linkage was established with several X chromosome markers with a lod score up to 3.8; almost the maximum possible score in this family. Our finding imply that a gene for the dominant expression of a neuronal degeneration is coded on X chromosome and raise the question of the role of X-linked genes that escape inactivation in this pathogenesis. More importantly, our finding that a gene causing ALS is localized on X-chromosome has direct investigational relevance to sporadic ALS, where epidemiological studies show male gender predominance(1.3:1) and earlier onset in men by 5-10 years.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.4
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• pp.273-279
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• 2010

Purpose: The purpose of this in vitro study was to compare the marginal adaptation of a ceramic-pressed-to-metal restoration with traditional metal-ceramic restoration. Materials and methods: Duplicating the prepared resin tooth, 20 metal dies were fabricated. Twenty metal copings of 2 groups which were metal ceramic restoration and pressed to metal restoration were fabricated. The marginal opening of each coping was measured with Microscope (BX 60M-36E $41D^{(R)}$: Olympus, Japan). After porcelain build-up, the marginal opening of metal ceramic restoration and pressed to metal restoration ($PoM^{(R)}$: Ivoclar vivadent., Liechtenstein) were also evaluated in the same method. The measurements were analyzed using Wilcoxon Signed Ranks test and Mann-Whitney U test. Results: Within the limits of this study, the results were as follows. 1. Metal-ceramic restorations in coping state ($64.93{\pm}12.48\;{\mu}m$) in compared with Metal ceramic restorations after porcelain build-up ($63.43{\pm}12.86\;{\mu}m$) had no significant difference in marginal adaptation. 2. Pressed-metal-ceramic restorations in coping state ($50.00{\pm}12.28\;{\mu}m$) in compared with Pressed metal ceramic restorations after porcelain build-up ($56.72{\pm}13.80\;{\mu}m$) had no significant difference in marginal adaptation. 3. Metal-ceramic restorations in compared Pressed-metal-ceramic restorations had no significant difference in marginal adaptation. Conclusion: Pressed-metal-ceramic restorations have the advantage of being technically less change through using of the lost-wax technique and this allows for the convenience of a full-contour ceramic wax-up as opposed to the more technique-sensitive layering method. Pressed-metal-ceramic restorations may be considered in clinic on the basis of the result of this study and the advantage of this system.

• Journal of Dental Rehabilitation and Applied Science
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• v.18 no.3
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• pp.179-184
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• 2002

To compare surface roughness in various porcelains and know effects of condensation, We used Ceramco dentin porcelain, Creation dentin porcelain, Creation margin porcelain, Vintage margin porcelain, Vintage dentin porcelain, and Vita dentin porcelain, and built up the powders with condensation or not, and then fired according to the instructions with porcelain furnace( Dekema, Germany ). We polished the samples step by step using the porcelain adjustment kit( Shofu Inc., Japan ), and then measured, compared and analysed Ra, Rz, and Rmax with Surftest SV-400( Mitutoyo Co., Japan ). 1. With condensation, roughness is significantly increased in Ceramco dentin porcelain (p<0.05) and decreased in Vita dentin porcelain(p<0.05). 2. In Ra, Vita dentin porcelain is significantly the roughest and Creation margin porcelain is rougher than others in no condensation, (p<0.05), and there is no difference under condensation. 3. In Rz, Vita dentin porcelain is significantly the roughest and Creation margin porcelain is rougher than others in no condensation, and Creation margin porcelain is significantly the roughest and Creation dentin porcelain is rougher than others under condensation(p<0.05). 4. In Rmax, Vintage dentin porcelain is significantly the roughest and Creation margin porcelain is rougher than others in no condensation, and Creation margin porcelain is significantly the roughest than others under condensation(p<0.05).

• Geotechnical Engineering
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• v.13 no.3
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• pp.5-20
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• 1997

A governing equation of uncoupled three dimensional finite strain theory of consolidation is presented. This equation is suitable for relatively thick layers, possessing large strain, non-linear material property, and variable permeability. A special numerical solution procedure has to be adopted for the finite difference scheme because the solution is not stable in using Forward-Time Centered-Space (FTCS) method and the governing equation is highly non-linear. The solution is capable of predicting settlement with respect to time. The results predicted by the developed method of analysis have been compared with those of experimental tests on different types of highly compressible soils with vertical wick drain. The uncoupled three dimensional finite strain theory of consolidation appears to predict settlement behavior well. A detailed comparison shows good agreement in terms of total settlement, and reasonable agreement with respect to time.

• Tunnel and Underground Space
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• v.14 no.3
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• pp.229-240
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• 2004

Coastal aquifers may serve as major sources fur freshwater. In many coastal aquifers, intrusion of seawater has become one of the major constraints imposed on groundwater utilization. The management of groundwater in coastal acquifers means making decision as to the pumping rate and the spatial distribution of wells. Several numerical techniques for flow and solute transport simulation can provide the means to achieve this goal. As a basic study to predict the intrusion of seawater in coastal phreatic aquifers, the coupled flow and solute transport analysis was conducted by use of the 3-D finite element code, SWICHA. In order to understand how the location and the shape of freshwater-seawater transition zone were affected by the boundary conditions and hydrogeologic variables, parametric study was carried out.

• Journal of Sasang Constitutional Medicine
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• v.28 no.3
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• pp.300-308
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• 2016

Objectives This case study was about a Taeyangin patient with Amyotrophic Lateral Sclerosis identified as Hae-Yeok pattern. In this study, we report the significant improvement of extremity weakness of this patient after Sasang Constitutional medicine treatment.Methods The patient was identified as Taeyangin Hae-Yeok pattern and treated with Ogapijangchuk-tang and acupuncture. Korean-Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (K-ALSFRS-R) was used to assess the overall function of the patient. And the Global Assessment Scale (GAS) was used to assess the change of upper and lower extremities weakness after the treatment.Result and Conclusion The K-ALSFRS-R total score decreased from 30 points to 26 points and extremity weakness showed significant improvement in GAS after 12 days treatment. Furthermore, walking distance was much longer after treatment. In conclusion, this study shows that Sasang constitutional medicine can be effective treatment for Taeyangin patient with Amyotrophic Lateral Sclerosis.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.3 s.246
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• pp.262-269
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• 2006

Segregation algorithms of the incompressible Wavier-Stokes equations using P1P1/P2P1 finite element formulation are newly proposed. P1P1 formulation allocates velocity and pressure at the same nodes, while P2P1 formulation allocates pressure only at the vertex nodes and velocity at both the vertex and the midpoint nodes. For a comparison of both the elapsed time and the accuracy between the two methods, they have been applied to the well-known benchmark problems. The three cases chosen are the two-dimensional steady and unsteady flows around a fixed cylinder, decaying vortex, and impinging slot jet. It is shown that the proposed P2P1 semi-segregation algorithm performs better than the conventional P1P1 segregation algorithm in terms of both accuracy and computation time.

• Journal of dental hygiene science
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• v.13 no.2
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• pp.135-141
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• 2013

One factor for successful prognosis of finished dental prosthesis is good marginal fit. The purpose of this study in vitro investigation was to compare the marginal fit of all-ceramic crown before and after porcelain veneering, to evaluate the influence of high temperature of the porcelain firing on the fit. For this experiment, model of abutment tooth of maxillary right central incisor was prepared. Ten working models were produced. Ten zirconia cores were made by dental computer aided design/computer aided manufacturing system. The marginal fit of specimens were examined using silicone replica technique. Silicone replicas were sectioned four times and were measured through a digital microscope (${\times}160$). Marginal fit is a distance connected between edge end part of specimen and abutment margin. Each specimens was measured twice, the first measurement was done prior to veneering porcelain firing, while the second measurement was done after the porcelain firing to evaluate this process. Statistical analyses were performed with paired t-test. $Mean{\pm}SD$ marginal fit was $60.8{\pm}14.2{\mu}m$ for zirconia core and $86.1{\pm}13.3{\mu}m$ for all-ceramic crown. They were statistically significant differences (p<0.001). But all specimens showed a marginal fit where the gap widths ranged within the clinical recommendation ($120{\mu}m$), all-ceramic crown production using the zirconia core was adequate.

• Journal of the Korean Magnetics Society
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• v.13 no.4
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• pp.182-186
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• 2003

A new axial pressing method using pulse magnetizing field was studied to improve the remanence of Nd-Fe-B sintered magnets. In order to make near-net shape green compacts of butterfly, disk, or coin magnets, conventional axial-type pressing has been normally used. However, compared to the transverse-type pressing, it is not possible to obtain higher remanence by this method because the magnetic alignment of powder begins to deteriorate when the density of green compacts increases over a critical value. On the other hand, we found that an axial pressing under pulse magnetizing field was very effective to increase the degree of magnetic alignment of powder, yielding remanences even higher than those obtained by the transverse pressing. In this study, it was revealed that appropriate tapping density and how to apply pulse magnetic held were important to improve the grain alignment and thus remanence of Nd-Fe-B sintered magnet.