• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.678-680
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• 2002

Vertically aligned carbon nanotubes(CNTs) have been grown on Ni-coated TiN/Si substrate by microwave plasma chemical vapor deposition using $H_2/CH_4$ mixture gas. We have investigated the Effect of process parameters on the growth of CNT. During the growth, microwave power, pressure, and growth temperature were varied from 300 W to 700 W, 10 Torr to 30 Torr, and 300 $^{\circ}C$ to 700 $^{\circ}C$. respectively. Then we controlled the size of CNTs. The structure of CNT was sensitively dependent on the process parameters.

• Journal of Sensor Science and Technology
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• v.18 no.2
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• pp.168-172
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• 2009

In this paper, we present the carbon nanotube field-effect transistor(CNT-FET) with a double-gate structure. A Carbon nanotube film was aligned by the Langmuir-Blodgett technique and $SiN_x$ was deposited to protect from water, oxygen, and other contaminants. We measured the electrical characteristics of the proposed device as the function of the $V_{BG}$, $V_{TG}$. From this result, we can confirm that proposed device might be employed as a biosensor.

• Smart Structures and Systems
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• v.5 no.6
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• pp.633-644
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• 2009

A simple method has been developed to detect the bonding condition of active fiber composites (AFC) adhered to the surface of a host structure. Large deformation actuating capability is one of important features of AFC. Edge delamination in adhesive layer due to large interfacial shear stress at the free edge is typically resulted from axial strain mismatch between bonded materials. AFC patch possesses very good flexibility and toughness. When an AFC patch is partially delaminated from host structure, there remains sensing capability in the debonded part. The debonding size can be determined through axial resonance measured by the interdigitated electrodes symmetrically aligned on opposite surfaces of the patch. The electrical impedance and modal response of the AFC patch in part adhered to an aluminum plate were investigated in a broad frequency range. Debonding ratio of the AFC patch is in inverse proportion to the resonant frequency of the fundamental mode. Feasibility of in-situ detecting the progressive delamination between AFC patch and host plate is demonstrated.

• Structural Engineering and Mechanics
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• v.71 no.6
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• pp.643-656
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• 2019

A new seismic design methodology was proposed for precast concrete diaphragms. This methodology adopts seismic design factors applied on top of current diaphragm design forces. These factors are aimed to produce diaphragm design strengths aligned with different seismic performance targets. These factors were established through extensive parametric studies. These studies used a simple evaluation structure with a single-bay rectangular diaphragm. The simple evaluation structure is suitable for establishment of the design factors over comprehensive structural geometry and design parameters. However, the application of the design factors to prototype structures with realistic layouts requires further verification and investigation. This paper presents diaphragm design of several precast concrete parking structures using the new design methodology and verification of the design factor through nonlinear dynamic time history analyses. The seismic behavior and performance of the diaphragm were investigated for the precast concrete parking structures. It was found that the design factor established for the new design methodology is applicable to the realistic precast concrete parking structures.

• ETRI Journal
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• v.36 no.5
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• pp.841-846
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• 2014

This study proposes a novel optical sensor structure based on a refractometer combining a bend waveguide with an air trench. The optical sensor is a $1{\times}2$ splitter structure with a reference channel and a sensing channel. The reference channel has a straight waveguide. The sensing channel consists of a U-bend waveguide connecting four C-bends, and a trench structure to partially expose the core layer. The U-bend waveguide consists of one C-bend with the maximum optical loss and three C-bends with minimum losses. A trench provides a quantitative measurement environment and is aligned with the sidewall of the C-bend having the maximum loss. The intensity of the output power depends on the change in the refractive index of the measured material. The insertion loss of the proposed optical sensor changes from 3.7 dB to 59.1 dB when the refractive index changes from 1.3852 to 1.4452.

• Phonetics and Speech Sciences
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• v.3 no.2
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• pp.37-52
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• 2011

This study investigates patterns of the alignment of the accentual peaks in bisyllabic words of the CVNCV, CVNV, and CVNNV structures in North Kyungsang Korean. Based on the tonal alignment, patterns of the F0 pitch excursion are discussed relative to one another. Issues are addressed concerning how the tonal targets are aligned, and how the tonal specifications of nasals in postvocalic, intervocalic, and prevocalic environments are supplied in the LH, HL, and HH classes. Tonal specification of nasals in various environments is accounted for by extension of the L target, displacement of the pitch peak, and interpolation between two tonal targets, depending on the tonal class. The results in this study provide preliminary evidence that the categorical alignment of the tonal targets is implemented by simply checking the presence or absence of a nasal before or after the nucleus vowel on the segmental string, without reference to the constituency of the nasal in the syllable structure. However, the prosodic structure has a key role to play in explaining speaker-dependent variations in the tonal alignment. Sensitivity to tautosyllabicity has an effect on the shape of the F0 contour, and disparity in the patterns of the pitch excursion is represented as a function of syllable structure correlated with segmental composition of the nasal.

• Journal of Powder Materials
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• v.27 no.3
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• pp.198-202
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• 2020

The effect of sublimable vehicles on the pore structure of Cu fabricated by freeze drying is investigated. The 5 vol% CuO-dispersed slurries with camphene and various camphor-naphthalene compositions are frozen in a Teflon mold at -25℃, followed by sublimation at room temperature. After hydrogen reduction at 300℃ and sintering at 600 ℃, the green bodies of CuO are completely converted to Cu with various pore structures. The sintered samples prepared using CuO/camphene slurries show large pores that are aligned parallel to the sublimable vehicle growth direction. In addition, a dense microstructure is observed in the bottom section of the specimen where the solidification heat was released, owing to the difference in the solidification behavior of the camphene crystals. The porous Cu shows different pore structures, such as dendritic, rod-like, and plate shaped, depending on the composition of the camphornaphthalene system. The change in pore structure is explained by the crystal growth behavior of primary camphor and eutectic and primary naphthalene.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.9
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• pp.1724-1728
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• 2007

In this paper we propose a novel electrode structure for high transmittance in the Patterned Vertical Alignment (PVA) LC cell. We use the 'TechWiz LCD' for calculation of the director configuration and optical characteristics. We studied the area decreasing the transmittance through the electrode structure for wide viewing angle and proposed new electrode design to change LC director configuration in the area. We show the comparison of the calculated optical transmittance between the conventional PVA mode and the proposed PVA mode. From the results, we confirm that the optical transmittance of the proposed structure of the PVA cell becomes higher.

• BMB Reports
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• v.32 no.2
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• pp.181-188
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• 1999

4-Aminobutyrate aminotransferase plays an essential role in the 4-aminobutyric acid shunt, converting 4-aminobutyrate to succinic semialdehyde. Recombinant 4-aminobutyrate aminotransferases were overexpressed as their catalytically active forms in E. coli by coproduction with thioredoxin and their solubilities were also dramatically increased. In order to study the structural and functional aspects of the C-terminal domain of brain 4-aminobutyrate aminotransferase, we have constructed a C-terminal mutant of pig brain 4-aminobutyrate aminotransferase and analyzed the functional and structural roles of C-terminal amino acids residues on the enzyme. The deletion of five amino-acid residues from C-terminus did not interfere with the kinetic parameters and functional properties of the enzyme. Also, the deletion did not affect the dimeric structure of the protein aligned along the subunit interface at neutral pH. However, the deletion of the C-terminal region of the protein changed the stability of its dimeric structure at acidic pH. The dissociation of the enzyme acidic, facilitated by the deletion of five amino acids from C-terminus, abolished the catalytic activity.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.5
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• pp.537-543
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• 2010

This paper presents a slot-shaped defected ground structure(DGS) which has multi-band rejection property. The proposed structure, in which the spiral slot-shaped defects with different size are aligned in the transverse direction to the guiding direction of the coplanar waveguide(CPW), provides multiple resonance frequencies. Compared with the simulated results, the band rejection characteristic is in good agreement with the measurement. Also, an equivalent circuit model of the proposed structure is presented, where the DGS on the ground plane is modeled as LC-resonators. This resonators are inductively coupled to the signal line through mutual inductance. From the equivalent circuit model, multi-band rejection property was derived.