• Archives of Reconstructive Microsurgery
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• v.21 no.2
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• pp.111-117
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• 2012

Purpose: To report the clinical results of the perforated-based propeller flap for lower extremity soft tissue reconstruction. Materials and Methods: Between January 2010 and June 2012, a total of 16 defects in the lower extremities were covered with perforator-based propeller flaps. Retrospective data for location and size of the defect, flap dimension, pedicle artery, pedicle rotation, complications were obtained. Results: Peroneal artery-based perforator flap were used in eleven cases, posterior tibial artery-based perforator flap in two cases, anterior tibial artery-based perforator flap in one case and medial plantar artery-based perforator flap in two cases. The average size of the flaps was $63cm^2$. The marginal skin necrosis of the flaps as a complication was developed in two cases, one of which was covered with split-thickness skin graft. There were no functional deficits from the donor site. Conclusion: For the reconstruction of lower extremities, the perforator-based propeller flap could be a reasonable alternative as it is a simple, safe and versatile technique.

• 한국지구과학회:학술대회논문집
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• 2005.09a
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• pp.304-314
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• 2005

The present study aims to develop animation module-based teaching-learning materials for a unit of middle school 3rd grade science, which contains the movement of the solar system, through the utilization of various forms of multimedia elements. The developed materials consist of 12 in total flash animation modules covering ‘movement of the Earth,’ ‘movement of the Moon,’ movement of the Planets,‘ etc. To analyze the student responses to the science classes to which the developed animation modules were to be applied, the researcher selected for subjects two third-grade classes that were made up of 60 students and later divided for an experimental group and a control group in a middle school located in Jeonju. The experimental group was treated with the animation module-based lessons developed in the present study while the control group was taught in the traditional teacher-centered ways. Tests for the science-related attitudes of the two groups were administered and the results showed that the mean score of the experimental group was significantly higher than the mean score of the control group (p<0.05) in the categories of ‘interest’ and ‘scientific attitude’. It was thus believed that the animation module-based teaching has a positive effect on the categories of ‘interest’ and ‘scientific attitude’. To assess the qualitative dimension of the developed materials, the researcher subjected them to the utilization of the 30 local science teachers and afterwards a survey was done with the 8 crucial items taken from the WBI evaluation test developed by Multimedia Education Support Center in 1998. The result was broadly positive in terms of lesson design and from a technological point of view.

• The Research Journal of the Costume Culture
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• v.12 no.3
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• pp.379-391
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• 2004

The purpose of this study was to examine the effects of uniform's color and motif on nurse's impression formation. The experimental design was 5×3×2(uniform color×motif ×perceiver's gender) factorial design with a between-subjects design. The experimental materials developed for the study were a set of stimuli and a response scale. The subjects were 738 undergraduate students of Daejon and Chungnam province. The SPSS package was used for data analysis which includes factor analysis, two-way ANOVA, Duncan's multiple range test, and Cronbach's α to measure the reliability. Results were as follows; The image or the stimulus was consisted of the 4 different dimensions(evaluation, sociability, ability, potency). All the independent variables showed some significant impression effects on selected dimensions. The motif and perceiver's gender also showed significant main effects as well as some interaction effects with the color variable on some selected impression dimension and the impression effects of the three variables in relationship to perceiving nurses' images. On a conclusion, these results supported the Gestalt theory.

• Transactions on Electrical and Electronic Materials
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• v.9 no.5
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• pp.193-197
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• 2008

On the purpose of increasing resonant frequency without sacrificing quality factor as well as much decreasing dimensions, corrugated micro beam resonator based on polycrystalline 3C-SiC films is the applicable solution. In this work, appropriate corrugated structure is suggested to increase resonant frequency of resonators. Micro beam resonators based on 3C-SiC films which have a two-side corrugation along the length of beams were simulated by finite element method and compared to a same-size flat rectangular. With the dimension of 36x12x0.5 ${\mu}m^{3}$, the flat cantilever has resonant frequency of 746 kHz. Meanwhile, with this size but corrugation width of 6 ${\mu}m$ and depth of 0.4 ${\mu}m$, the corrugated cantilever reaches the resonant frequency at 1.252 MHz.

• Advances in Computational Design
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• v.2 no.1
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• pp.43-56
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• 2017

The aim of this paper is to develop software for designing of steel reinforced elastomeric isolator (SREI) according to American Association for State Highway and Transportation Officials Load and Resistance Factor Design (AASHTO LRFD) Specifications. SREI is used for almost all bridge types and special structures. SREI-structures interface defines support boundary conditions and may affect the seismic performance of bridges. Seismic performance of the bridge is also affected by geometrical and materials properties of SREI. The selection of SREI is complicated process includes satisfying all the design constraints arising from code provisions and maximizing performance at the lowest possible cost. In this paper, design stage of SREI is described up to AASHTO LRFD 2012. Up to AASHTO LRFD 2012 analysis and design program of SREI performed different geometrical and material properties are created with C# object-oriented language. SREI-CAD, name of the created software, allows an accurate design for economical estimation of a SREI in a short time. To determine types of SREI effects, two different types of bearings, rectangular and circular with similar materials and dimension properties are selected as an application. Designs of these SREIs are completed with SREI-CAD. It is seen that ensuring the stability of circular elastomer bearing at the service limit state is generally complicated than rectangular bearing.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.78-78
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• 2015

Metamaterials, artificially structured nanomaterials, have enabled unprecedented phenomena such as invisibility cloaking and negative refraction. Especially, hyperbolic metamaterials also known as indefinite metamaterials have unique dispersion relation where the principal components of its permittivity tensors are not all with the same signs and magnitudes. Such extraordinary dispersion relation results in hyperbolic dispersion relations which lead to a number of interesting phenomena, such as super-resolution effect which transfers evanescent waves to propagating waves at its interface with normal materials and, the propagation of electromagnetic waves with very large wavevectors comparing they are evanescent waves and thus decay quickly in natural materials. In this abstract, I will focus discussing our efforts in achieving the unique optical property overcoming diffraction limit to achieve several extraordinary metamaterials and metadevices demonstration. First, I will present super-resolution imaging device called "hyperlens", which is the first experimental demonstration of near- to far-field imaging at visible light with resolution beyond the diffraction limit in two lateral dimensions. Second, I will show another unique application of metamaterials for miniaturizing optical cavity, a key component to make lasers, into the nanoscale for the first time. It shows the cavity array which successfully captured light in 20nm dimension and show very high figure of merit experimentally. Last, I will discuss the future direction of the hyperbolic metamaterial and outlook for the practical applications. I believe our efforts in sub-wavelength metamaterials having such extraordinary optical properties will lead to further advanced nanophotonics and nanooptics research.

• Korean Journal of Materials Research
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• v.3 no.4
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• pp.344-351
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• 1993

The crystal structunes of poly(ethylene terephthalate-eo-1, 4 cyciohexylene dimethylene terephthalate), P(ET CT), copolymers were studied by CPMAS solid state NMR spectroscopy. With the estimation of methylene resonance peaks, the bulkier CT component of the copolymer in the range of 0 20 mol% CT is excluded from the ET crystal lattice, whereas smaller ET component of the copolymer in the range of 66 100 mol% CT can be partially included into the CT crystal lattice. Those different crystallization behavior can be explained with the difference in chain bulkiness and crystal lattice dimension be tween two copolymer compurwnts.

• Transactions on Electrical and Electronic Materials
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• v.1 no.1
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• pp.40-44
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• 2000

Metal-ferroelectric-insulator-semoiconductor field effect transistor (MFISFETs) were fabricated using CMOS processes. The Pt/SBT/NO combined layers were etched for forming a conformal gate by using Ti/Cr metal masks and a two step etching method, By the method, we were able to fabricate a small-sized gate with the dimension of $16/4{\mu}textrm{m}$ in the width/length of gate. It has been chosen the non-self aligned source and drain implantation process, We have deposited inter-layer dielectrics(ILD) by low pressure chemical vapor deposition(LPCVD) at $380^{circ}C$ after etching the gate structure and the threshold voltage of p-channel MFISFETs were about 1.0 and -2.1V, respectively. It was also observed that the current difference between the $I_{ON}$(on current) and $I_{OFF}$(off current) that is very important in sensing margin, is more that 100 times in $I_{D}-V_{G}$ hysteresis curve.

• Transactions of Materials Processing
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• v.18 no.5
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• pp.410-415
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• 2009

Experimental and numerical studies were performed to examine the effect of material temperature and reduction ratio on friction coefficient during hot flat rolling. We carried out a single pass pilot hot flat rolling test at the temperatures range of $900{\sim}1200^{\circ}C$ and measured the spread of deformed material while reduction ratio varied from 20% to 40%. Materials used in this study were a high carbon steel and two alloy steels. The dimension of specimen used in hot rolling experiment was $50mm{\times}50mm{\times}300mm$. We performed a series of finite element simulation of the hot rolling process to compute the friction coefficient change in terms of steel grade and reduction ratio. Results showed that temperature dependency of friction coefficient is not noteworthy but the effect of reduction ratio on friction coefficient is quite large. For high carbon steel, friction coefficient at reduction ratio of 30% is lower than that at that of 20%. Meanwhile friction coefficient at reduction ratio of 40% was one and half times large compared with that at that of 20%. The effect of steel grade on friction coefficient was significant when reduction ration was large, e.g., 40%.

• Journal of Sensor Science and Technology
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• v.27 no.6
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• pp.421-426
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• 2018

To develop a piezoelectric inkjet printhead for high-resolution and high-speed printing, we studied the characteristics of an inkjet printhead by analyzing the major design parameters. An analytical model for the inkjet printhead was established, and numerical analysis of the coupled first-order differential equation for the defined state variables was performed using state equations. To design the dimension of the inkjet printhead with a driving frequency of 100 kHz, the characteristics of the flow rate and discharge pressure of the nozzle were analyzed with respect to design variables of the flow chamber, effective sound wave velocity, driving voltage, and voltage waveform. It was predicted that the change in the height of the flow chamber does not significantly affect the Helmholtz resonance frequency and discharge speed of the nozzle. From the analysis of change in flow chamber width, it is observed that as the width of the flow chamber increases, the ejection speed greatly increases and the Helmholtz resonance frequency decreases considerably, thereby substantially affecting the performance of the inkjet printhead.