• Journal of Korean Ophthalmic Optics Society
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• v.3 no.1
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• pp.9-13
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• 1998

Visual system of Korean Salamander(Hynobius leechi) was morphologically studied. Fertilized eggs in egg sacs were collected and were developed in sterile saline solution. Various sized larvae of 5-30mm in length were fixed. Specimens were paraffin sectioned and were observed under light microscope. In 5mm length larva, lens rudiment induced by optic cup was combined with sensory ectoderm. The shape of lens was changed as spherical in 12mm length larva, but the retinal layer did not differentiated into three layers. The differentiation of retinal layer was clear in 14-16mm length larva. The central region of lens fibers was degenerated. Iris and ciliary body were formed from the marginal zone of optic cup in 20mm length larva. Choroid was thicker in elder eye of 30mm length larva and cartilage developed at outer region of optic cup. The outer segment of photoreceptor cell layer grew longitudinally. Optic nerve was connected to the ventral part of brain through cartilage.

• BMB Reports
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• v.49 no.12
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• pp.655-661
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• 2016

Polymer brush is a soft material unit tethered covalently on the surface of scaffolds. It can induce functional and structural modification of a substrate's properties. Such surface coating approach has attracted special attentions in the fields of stem cell biology, tissue engineering, and regenerative medicine due to facile fabrication, usability of various polymers, extracellular matrix (ECM)-like structural features, and in vivo stability. Here, we summarized polymer brush-based grafting approaches comparing self-assembled monolayer (SAM)-based coating method, in addition to physico-chemical characterization techniques for surfaces such as wettability, stiffness/elasticity, roughness, and chemical composition that can affect cell adhesion, differentiation, and proliferation. We also reviewed recent advancements in cell biological applications of polymer brushes by focusing on stem cell differentiation and 3D supports/implants for tissue formation. Understanding cell behaviors on polymer brushes in the scale of nanometer length can contribute to systematic understandings of cellular responses at the interface of polymers and scaffolds and their simultaneous effects on cell behaviors for promising platform designs.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.227-227
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• 1999

Plasma display panel(PDP) is a leading technology for large-area flat panel displays. A current issue in operating the PDP cell is that the efficiency of the PDP cell is very low. To increase the efficiency of the PDP cell, the visible light needs to be maximized and the power consumption minimized. Since the excited xenons are related to the production of the visible light, it is important to optimize the cell geometry and the gas composition that produce the excited xenons more efficiently. A 2D-fluid code (FL2P) is developed and used to simulate the plasma dynamics and the radiation transport in the PDP cell. The cell is optimized with the code for various operating conditions and cell dimensions such as the voltage pulse, electrode length, electrode spacing, gap size, dielectric constant, gas mixture ratio, pressure, and pulse duration.

• ETRI Journal
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• v.28 no.4
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• pp.506-508
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• 2006

A frequency selective surface (FSS), whose unit cell consists of a ternary tree loop loaded with a modified tripole, is proposed to block multiple frequency bands. Target frequency bands correspond to Korean personal communication services, cellular mobile communication, and 2.4 GHz industrial, scientific, and medical bands. Through the adjustment of inter-element and inter-unit cell gaps, and adjustment of the length of elements, we present an FSS design method that makes the precise tuning of multiple resonance frequencies possible. Additionally, to verify the validity of our approach, simulation results obtained from a commercial software tool and experimental data are also presented.

• Journal of the Korean Wood Science and Technology
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• v.15 no.3
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• pp.14-23
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• 1987

This study was carried out to investigate the anatomical characteristics, the radial and axial variation of the cell dimension and bulk density for four bamboo species used as the major material of bamboo products in Korea; Phyllostachys(P.bambusoides, P.edulis, P.nigra var.henonis, and Pnigra). The results obtained were summarized as follows; 1) In the outer part of culm, the mophological difference of cell diameter and distribution were not acknowledged. However, gum-like substance was occurred In the epidermis, hypodermis, cortex and metaxylem vessel of P.nigra, while it was occured only in the metaxylem vessel of P.edulis. 2) The protoxylem vessel in the central zone of culm-wall could be in the two types; the first type consisted of 4-5 small cell pieces occurred in P.edulis and P.nigra var. henonis, the second type of 1-2 large cell pieces in P.bambusoides and P.nigra. And transition of cell diameter from the vascular bundle sheath to the ground tissue was gradually enlarged in P.nigra and P.edulis but abruptly in P.bambusoides and P.nigra var. henonis. 3) Thin-wall tyloses were well developed in the outer and central zone of culm-wall in four species. 4) Compared with the central part of culm-wall, the number of parenchyma cells and the amount of the vascular bundle sheaths per unit area were a few in the inner part. The inner part nearest to the pith cavity was consisted of thick-well parenchyma cell. 5) The dimensional variations of metaxylem vessel and parenchyma cell in the radial direction were decreased from the inner part to the epidermis in all species observed. 6) The fiber length was the maximum in the central zone and its diameter was increased from the inner part to the outer part. In the axial variation. fiber length was slightly increased from the base and then decresed slowly toward the top, and its diameter was reverse. 7) The axial variation of the bulk density was continuously increased from the base toward the top and its radial variation was rapidly increased from the inner part to the epidermis.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2256-2261
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• 2015

In the power plant using high temperature fuel cells such as Molten Carbonate Fuel Cell(MCFC), and Solid Oxide Fuel Cell(SOFC), the generated electric power per area of power generation facilities is much higher than any other renewable energy sources. - High temperature fuel cell systems are capable of operating at MW rated power output. - It also has a feature that is short for length of the line for connecting the interior of the generation facilities. In normal condition, these points are advantages for voltage drops or power losses. However, in abnormal condition such as fault occurrence in electrical system, the fault currents are increased, because of the small impedance of the short length of power cable. Commonly, to minimize the thermal-mechanical stresses on the stack and increase the systems reliability, we divided the power plant configuration to several banks for parallel operation. However, when a fault occurs in the parallel operation system of power main transformer, the fault currents might exceed the interruption capacity of protective devices. In fact, although the internal voltage level of the fuel cell power plant is the voltage level of distribution systems, we should install the circuit breakers for transmission systems due to fault current. To resolve these problems, the SFCL has been studied as one of the noticeable devices. Therefore, we analyzed the effect of application of the SFCL on bus tie in a fuel cell power plants system using PSCAD/EMTDC.

• Biomedical Science Letters
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• v.7 no.4
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• pp.167-172
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• 2001

Nebulin is an approximately 700 kDa filamentous protein in vertebrate skeletal muscle. It binds to the Z line and also binds side-by-side to the entire thin actin filament in a sarcomere. The correlation of nebulin size with thin filament length have led to the suggestion that nebulin acts as a molecular ruler for the length of thin filaments. The C-terminal part of human nebulin is anchored in the sarcomeric Z-disk and contains an SH3 domain. SH3 domains have been identified in an ever-increasing number of proteins important for a wide range of cellular processes, from signal transduction to cytoskeleton assembly and membrane localization. However, the exact physiological role of SH3 domains remains, in many cases, unclear. To explore the role of nebulin SH3 in the cytoskeletal rearrangement that accompanies myoblast differentiation, we transfected sense and antisense nebulin SH3 domain fused to enhanced green fluorescent protein in myoblast. Cells expressing nebulin SH3 fragment showed decrease of cell-cell adhesion, and cells transfected with antisense nebulin SH3 gene showed a rounded cell morphology and loss of cell-matrix adhesion. No alteration in cell shape and differentiation were observed in control cells expressing enhanced green fluorescent protein. Perturbation of nebulin altered the cell shape and disrupted cell adhesion in myoblast, demonstrating that nebulin can affect cytoskeleton rearrangement.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.952-957
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• 2005

A sensitivity analysis study was performed to examine the effects of cell size on a distributed non-point source pollution model. The model, AnnAGNPS, whiff is a modified version of USDA's AGNPS, was applied to Eung stream watershed, a tributary of Cheongmi stream located in the South Branch of Han River System. The model components and results, such as channel length, slope, land use, and delivery ratio, were analyzed according to the various cell sizes from 10 to 200 ha. As cell sire increases, channel length decreases due to short-circuiting of meandering creek. The decreased channel length has more significant effects on the model results than any other geomorphological change. When the effects of land use and soil distribution are excluded, sediment delivery loads increase due to shorter time to reach the outlet of the watershed in larger tell size. When those effects are included, however, sediment delivery loads decrease in larger fell size because the variety of land use types can not be inputted. The predominant land use in the applied watershed is forest with very low soil erosion such that the predicted sediment delivery might be much lower than real system. The cell size of 30 ha was determined to produce the most appropriate resolution. Surface runoff and non-point source loads of TN, TP and BOD were predicted and the results agree well with the field measurements. From this study, it was shown that the model results would be very dependent on variations of topography, land use, and soil distribution, as a function of cell size, and the optimum cell size is very important for successful application of distributed non-point source pollution model.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.207.3-208
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• 2003

Peroxisome proliferator-activated receptor (PPAR), a member of the nuclear hormone receptor superfamily, is a transcription factor activated by specific natural or synthetic ligands. It is involved in various cellular processes including adipogenesis, inflammation, cell cycle progression and carcinogenesis. Here, we report the production and characterization of a PPARgamma subtype-specific monoclonal antibody P${\gamma}$ 48.34A, which was raised against full-length human PPARgamma protein. (omitted)

• Journal of the Korean Ceramic Society
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• v.34 no.11
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• pp.1139-1150
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• 1997

A model for predicting the relative density and the compressive strength of open-cell ceramics with three-dimensional network structure was proposed through the interpretation of their macrostructure and fracture mechanics. The equation predicting the relative density was derived under the assumption that the open-cell structure was a periodic array of the tetrakaidecahedron unit cell consisting of cylindrical struts containing the internal hollow with the shape of a triangular prism. The model for compressive strength of open-cell ceramics with the hollow strut was also developed by modifying conventional model which based on fracture behavior of them subjected to the compressive stress. Both the relative density and the compressive strength were expressed in terms of the ratio of the strut diameter to the length together with the ratio of the hollow size to the strut diameter. The proposed model for the relative density and the compressive strength of the alumina-zirconia composite with open-cell structure were accorded well with the experimental values, whereas Gibson-Ashby and Zhang's model did not show such a good agreement.