• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.695-700
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• 2007

The cycloinulooligosaccharide fructanotransferase (CFTase) gene (cft) from Paenibacillus macerans (GenBank access code AF222787) was expressed on the cell surface of Saccharomyces cerevisiae by fusing with Aga2p linked to the membrane-anchored protein Aga1p. The surface display of CFTase was confirmed by immunofluorescence microscopy and enzymatic assay. The optimized reaction conditions of surface-displayed CFTase were as follows; pH, 8.0; temperature, $50^{\circ}C$; enzyme amount, 30 milliunit; substrate concentration, 5%; inulin source, Jerusalem artichoke. As a result of the reaction with inulin, cycloinulohexaose was produced as a major product along with cycloinuloheptaose and cycloinulooctaose as minor products.

• Textile Coloration and Finishing
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• v.13 no.1
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• pp.18-22
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• 2001

Effects of cationic surfactants old the wetting behavior of the DMDHEU treated cotton fibers were investigated using a technique based on the Wilhelmy principle. The results indicated that Interactions between the fiber and water ill the interface make contributions to wettability of the cotton fiber surface because of reorientation of polar groups at the interface. The effects of types and concentration of cationic surfactant on the wettability of both control and durable press(DP) finished cotton fiber are discussed. Below and near the critical micelle concentration(cmc), the adsorption of hexadecyltrimethylammoniumbromide(HTAB) on the control fiber makes the fiber surface more hydrophobic. Near and above the cmc of octadecyltrimethylammouniumbromide(OTAB) , the decrease in advancing contact angles indicates that the control cotton surface became hydrophilic. By the adsorption of both HTAB and OTAB onto the fiber surface, the hydrophobicity of the DP finished fiber surface became mere hydrophilic.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.3-4
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• 2007

Orientational ordering of polar molecules and excess charges at the interface are main origins of surface polarization. For organic electronics, probing and control of these two surface polarization phenomena are key issues. In this presentation, I report a novel electrical measurement that can directly probe orientational dipolar motion in surface monolayers by Maxwell-displacement-current, and also report a novel optical technique that allows carrier motions in organic materials by measuring the optical second harmonic signals activated by the electric field. Then I discuss how the control of dipolar motions and carrier motions are linked to organic electronics applications such as organic field effect transistors.

• Journal of Periodontal and Implant Science
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• v.36 no.2
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• pp.319-334
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• 2006

Mechanical and chemical methods are the two ways to treat the implant surfaces. By using mechanical method, it is difficult to eliminate bacteria and by-products from the rough implant surface and it can also cause the structural change to the implant surface. Therefore, chemical method is widely used in order to preserve and detoxicate the implant surface more effectively. The purpose of this study is to evaluate the effect of tetracylcline-hydrochloride(TC-HCI) on the change of implant surface microstructure according to application time. Implants with pure titanium machined surface, SLA surface and porous surface were used in this study. Implant surface was rubbed with sponge soaked in 50mg/ml TC-HCI solution for $\frac{1}{2}$ min., 1 min., $1\frac{1}{2}$ min., 2 min., and $2\frac{1}{2}$ min. respectively in the test group and with no treatment in the control group. Then, specimens were processed for scanning electron microscopic observation. 1. Both test and control group showed a few shallow grooves and ridges in pure titanium machined surface implants. There were not significant differences between two groups. 2. In the SLA surfaces, the control specimen showed that the macro roughness was achieved by large-grit sandblasting. Subsequently, the acid-etching process created the micro roughness, which thus was superimposed on the macro roughness. Irrespective of the application time of 50mg/ml TC-HCI solution, in general, test specimens were similar to control. 3. In the porous surfaces, the control specimen showed spherical particles of titanium alloy and its surface have a few shallow ridges. The roughness of surfaces conditioned with tetracycline-HCI was lessened and seen crater-like irregular surfaces relative to the application time. In conclusion, pure titanium machined surfaces and SLA surfaces weren't changed irrespective of the application time of tetracycline-HCI solution. But the porous surfaces conditioned with tetracycline-HCI solution began to be slightly changed from 2 min. This results are expected to be applied to the regenerative procedures for peri-implantitis treatment.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.1 s.178
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• pp.113-120
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• 2006

This paper proposed the control algorithm fur aspheric surface grinding and was verified by the experiment. The functions of the algorithm were simultaneous control of the position and interpolation of the aspheric curve. The non-linear formula of the tool position was derived from the aspheric equations and the shape of the tool. The function was partitioned by an certain interval and the control parameters were calculated at each control section. The movement in a session was interpolated with acceleration and velocity. The position error was feed-backed by rotary encorder. The concept of feedback algorithm was correcting position error by increasing or decreasing the speed. In the experiment, two-axis machine was controlled to track the aspheric surface by the proposed algorithm. The effect of the control and process parameters was monitored. The result showed that the maximum tracking error was under sub-micro level for the concave and convex surfaces.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.100-103
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• 2005

In this study, tool path control algorithm for aspherical surface grinding was derived and discussed. The aspherical surface actually means contact points between lens and tool. Tool positions are generally defined at the center of a tool, so there is difference between tool path and lens surface. The path was obtained from contact angle and relative position from the contact point. The angle could be calculated after differentiating an aspheric equation and complex algebraic operations. The assumption of the control algorithm was that x moves by constant velocity while z velocity varies. X was normal to the radial direction of lens, but z was tangential. The z velocities and accelerations were determined from current error and next position in each step. In the experiment, accuracy of the control algorithm was checked on a micro-precision machine. The result showed that the control error tended to be diminished when the tool diameter increased, and the error was under sub-micro level.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.10a
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• pp.164-168
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• 2001

In this paper, we introduce a new sliding surface adaptable to arbitrary initial conditions. The surface is initially designed to pass given intial errors and subsequently moves towards a predetermined surface via rotating or/and shifting. We call it as a moving sliding surface (MSS) comparing with the conventional ones, for instances, employed by Slotine and Sastry. Using the MSS, it is shown that the tracking is much faster than conventional one without increasing the magnitude of discontinuous control gain. To demonstrate some advantages of the proposed method, we apply the MSS to the path tracking control of a two-degree-of-freedom robotic manipulator subjected to external disturbances.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10c
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• pp.145-150
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• 1998

This study deals with the effect on performance of epoxy resign mortar mixed special cement for surface control and maintenance of aging concrete construction. The test of main property of epoxy resign in this study are the evaluation on the adhesive strength between substrate and epoxy resign mortar under the environment of wet or concrete substrate surface. We gained the test results of good adhesive strength over 15 kgf/$\textrm{cm}^2$ under the wet and dry condition of concrete surface.

• Journal of Korean Physical Therapy Science
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• v.15 no.1
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• pp.67-74
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• 2008

A decrease in the ability to maintain static and dynamic balance after stroke could be related to the inability to select reliable sensory information in producing relative motor action needed to maintain postural stability. The purpose of this study was to compare the effects of two different types of surface conditions on the balancing ability of subjects with stroke. Eighteen hemiparetic subjects were assigned to an experimental and control group participating in a six－week rehabilitative therapeutic exercise program focusing on balance and mobility. Exercises were performed 3 to 5 times per week in a stable surface condition by the control group, and in an unstable surface condition by the experimental group. Pre－ and post test assessments involved the measurement of the static balance and dynamic balance, respectively by 7－item Berg Balance Scale－3P and by Pro－3 Balance System. Results showed that under the unstable surface condition, static balance in the experimental group showed more improvement than that of the control group.(Statistically, not very significant.) All the aspects of dynamic balance and mediolateral sway(balance) improved significantly than those of the control group. However, there were no significant differences between two groups. Overall, it can be concluded that under the unstable surface condition, the rehabilitative therapeutic exercise programs are effective in improving the dynamic balance of stroke subjects. The results suggest that the adaptation of the unstable surface in the rehabilitative therapeutic exercises could be effective for the patients with hemiplegia in balance. Further studies are needed to confirm the effectiveness of the unstable surface on improving balance and postural stability of hemiplegics.

• Journal of Periodontal and Implant Science
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• v.29 no.3
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• pp.607-621
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• 1999

This study examined the human fibroblasts cell attachment to commercially pure titanium surface which had been instrumented by 3 types of periodontal instruments. Commercially pure titanium plates were uniformly scaled using plastic, stainless steel, titanium curette. these all experimental groups 65 undirectional strokes with the designated curettes. Alteration of the surfaces due to instrumentation was evaluated by Form Talysurf(R) and reported as Ra value(mean surface roughness). Then other experimental groups were immersed in a cell suspension of human gingival fibroblasts($1{\times}10^5$ cell/ml). After 3 days of culture, cell attachment and morphology was observed by SEM, and attached cell were counted by Hemocytometer. A significant difference in mean Ra value was observed for surface instrumented by metal curette compared to either control surface or surface instrumented by the plastic curette(P<0.01). No stastically significant difference was noted between control surface and those instrumented by the plastic curette. SEM observation showed that cell morphology and attachment to the commercially pure titanium plate was similar appearance on the all experimental groups. Experimental groups instrumented by titanium curette and stainless steel curette were more attached cell number than control group, but experimental group instrumented by plastic curette were similar with control groups(P<0.01). In summary, metal curette produced an significant alteration of the commercially pure titanium surface and more favorable surface topography for cell attachment. Otherwise plastic curette was insignificantly altered the commercially pure titanium surface(P<0.01).