• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.333-338
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• 2001

Fractal geometry is a non-Euclidean geometry which has been developed to quantitative analysis irregular or fractional shapes. Fractal dimension of irregular surface has fractal values ranging from 2 to 3 and of irregular line profile has fractal values ranging from 1 to 2. In this paper, quantitative analysis of crack growth patterns during the fracture processing of fiber-reinforced cement composites based on fractal geometry. The fracture behaviors of fiber reinforced mortar beams subjected to three-point loading in flexure. The beams all had a single notch depth, but varing volume fractions of polypropylene, cellulose fibers. The crack growth behaviors, as observed through the image processing system, and the box counting method was used to determine the fractal dimension, Df. The results showed that the linear correlation exists between fractal dimension and fracture energy of the fiber reinforced cement mortar.

• Journal of Periodontal and Implant Science
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• 제23권1호
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• pp.135-143
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• 1993

The investigation was undertaken to determin the altered function and structure of granulation tissue fibroblasts. Human granulation-tissue fibroblasts were cultured from periodontal chronic inflammatory lesions (SBI index : above 3) and compared with healthy gingival connective tissues fibroblasts a control(SBI index : below 1). Granulation tissue fibroblasts proliferated with a slower growth rate and exhibited larger cell size than control cells. Total protein profile of granulation tissue fibroblasts was almost identical to that of control cells with some exception. These results support tha theory that granulation tissue fibroblasts represent a distinct phenotype of fibrotic cells.

• Journal of computational fluids engineering
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• 제3권1호
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• pp.100-107
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• 1998

A numerical analysis of thermal stress over temperature variations near the crystal-melt interface is carried out for a floating-zone growth of Cadmium Telluride (CdTe). Thermocapillary convection determines crystal-melt interfacial shape and signature of temperature in the crystal. Large temperature gradients near the crystal-melt interface yield excessive thermal stresses in a crystal, which affect the dislocations of the crystal. Based on the assumption that the crystal is elastic and isotropic, thermal stresses in a crystal are computed and the effects of operating conditions are investigated. The results show that the extreme thermal stresses are concentrated near the interface of a crystal and the radial and the tangential stresses are the dominant ones. Concentrated heating profile increases the stresses within the crystal, otherwise, the pulling rate decreases the stresses.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• 제19권2호
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• pp.77-87
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• 2006

Objectives : We studied Effect of Platycodon grandiflorum on Lung carcinoma Methods : By using cDNA microarray technique, we analyzed the effects of AEPG(aqueous extract of Platycodon grandiflorum) on the gene expression profile. Results : Out of 384 genes screened associated with growth inhibition of carcinoma cell, 9 genes were founded to be affected in their expression levels by more than 1.2-fold after treatment with AEPG. And 67 genes were changed the expression level 0.5 times more than that of reference RNA after treatment of AEPG. Conclusions: These findings suggest that P. grandiflorum has strong potential for development as an agent for prevention and treatment against human lung cancer.

• The korean journal of orthodontics
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• 제8권1호
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• pp.19-26
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• 1978

This study was undertaken to estabish the cephalometric standards of Hellman dental age III A group of Korean on the roentgenocephalometry. The subjects consisted of 26 males and 29 females with the normal occlusion and acceptable profile. The following conclusions were obtained; 1) The tables of mean and standard deviation were made from the measurements of both male and female. 2) A ll linear measurements in male were greater than those in female. 3) Mandibular growth rate of female was greater than that of male. 4) Comparision of the childern in Hellman dental age III A with those in the late primary dentition indicated the tendency of facial vertical growth.

• Journal of the Korean Crystal Growth and Crystal Technology
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• 제5권4호
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• pp.386-393
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• 1995

A Abstract Producing process of FGM by SHS process has been investigated and $TiB_2$/Cu based FGM was fabricated by the process. When raw material powders were stacked on, Cu substrate, composition profile can be graded. This stacked body was compressed and vacuum­s sealed into the capsule for the synthesis. This sample was ignited and compressed under high h hydro - pressure. By the observation of the crystal phases and microstructures of produced $TiB_2$/Cu FGM samples, the compositional gradient was able to be identified.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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• pp.160-161
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• 2003

Thermocapillary convection is a surface tension driven flow due to a temperature gradient along an interface. It occurs during a crystal-growth process and therefore understanding the convection is important to material processing in microgravity. Although modelling of the float-zone crystal-growth process has been of interest for a few decades, most studies of liquid bridges assumed non-deformable flat surfaces. In reality, the surface profile, g(t,z), is unknown and should be obtained as a solution to the coupled transport equations along with the surface force balance. Here we report on a numerical study of axisymmetric thermocapillary convection in liquid bridges with deformable surfaces. The interface is determined as part of the complete solution. The influence of the capillary number (Ca), Reynolds number (Re), Prandtl number (Pr) and aspect ratio(Ar) on the dynamics is explored.

• Journal of Life Science
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• 제2권4호
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• pp.232-239
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• 1992

UDP_GlcNAc is metabolized to form vegetative cell wall, cortical peptidoglycans, and outermost layer consisting of galactosamine-6-phosphate ploysaccharide in life cycle of Bacillus megaterium. To obtain a better understanding of the UDP-GlcNAc regulation, we examined the activity of the common first enzyme for the synthesis of nucleotide precursors of peptidoglycans, enoylpyruvate transferase by newly developed method. Both the specific and the total activity decreased after the end of exponential growth followed by and increase from t5 but decreased again parallel to the appearance of the activity of UDP_GlcNAc-4-epimerase. Antibody specificity to anti-transferase IgG and the elution profile on DEAE-Sepharose revealed that B. megaterium has at least two enoylpyruvate transferase isozymes, and UDP_GlcNAc was metabolized to vegetative cell wall and cortical peptidoglycan by each isozme in exponential growth and in sporulation, respectively in life cycle.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 한국소성가공학회 1997년도 춘계학술대회논문집
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• pp.175-178
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• 1997

A modified Mukerjee's model considering the microstructural evolution was developed to study the superplastic bulge forming process of Ti-6Al-4V alloy. Through the microstructual observation after deformation, it was found that the grain growth rate of uniaxially tested specimens was different from that of biaxially deformed specimens. From this result, bulge forming experiments with and without back pressure were performed to examine the grain growth behavior and to compare the results of biaxial test with those of triaxial test. Good agreement between the prediction by a modified Mukerjee's model and the experimental measurements was obtained for bulge profile and thickness distribution.

• Progress in Superconductivity
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• 제13권3호
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• pp.151-157
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• 2012

In this paper, we used E-J constitutive law and H-formulation to calculate magnetic field profile, current density, and magnetization of high temperature superconductor (HTS) placed in time varying applied magnetic field. Finite element method (FEM)-based software, Comsol Multiphysics 3.5a, was employed to simulate 2-dimensional model of a superconducting thin strip. The numerical results based on Kim's critical state model were compared with the case of strip in a perpendicular field in the Brandt's paper as well as experimental data observed by Scanning Hall Probe and SQUID.