• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.40.2-40.2
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• 2011

As the old saying 'nothing is complete unless you put it in final shape', although nanosheets (NSs) are a promising functional building block for various electrochemical applications, their true value cannot be realized until they are well woven into electrical conducting materials. As an effort to determine their ideal shape, in this study, a unique manufacturing route to build a layer-by-layer (LBL) structure of two-dimensionally ordered, free-standing ${\beta}$-nickel hydroxide nanosheets (${\beta}$-NHNSs) that are fully electrically addressed with single-wall carbon nanotube fabrics was demonstrated, and its capabilities were verified through a comparative study on the differences between a simple bulky and LBL-structured electrochemical cathode, representing two extreme cases. The LBL-structured cathode showed a discharging current peak that was 25 times larger than the bulky structured one measured in cyclic voltammetry, which implies that the LBL structure is near an ideal electrode configuration for NS-based electrochemical applications.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.837-850
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• 2013

Bovine viral diarrhea virus (BVDV), a major pathogen of cattle, is a well-characterized pestivirus which has been used as a good model virus for HCV. The RNA-dependent RNA polymerase (RdRp) plays a key role in the RNA replication process, thus it has been targeted for antivirus drugs. We employed two-dimensional quantitative structure-activity relationship (2D-QSAR) and molecular field analysis (MFA) to identify the molecular substructure requirements, and the particular characteristics resulted in increased inhibitory activity for the known series of compounds to act as effective BVDV inhibitors. The 2D-QSAR study provided the rationale concept for changes in the structure to have more potent analogs focused on the class of arylazoenamines, benzimidazoles, and acridine derivatives with an optimal subset of descriptors, which have significantly contributed to overall anti-BVDV activity. MFA represented the molecular patterns responsible for the actions of antiviral compound at their receptors. We conclude that the polarity and the polarizability of a molecule play a main role in the inhibitory activity of BVDV inhibitors in the QSAR modeling.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.126-129
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• 2015

Device-to-device (D2D) communications, a subset of Proximity-based Services that enables direct communication between LTE network subscribers, is gaining popularity. It is well underway to be adopted in cellular communication systems for pedestrian and connected-vehicles alike. In this paper, we briefly present our model of an Evolved Packet Core Network-assisted device discovery simulator and show the applicability of Proximity-based Services for Vehicular Ad-hoc Networks. Through the performance evaluation based on the developed simulation environment, it is shown that in case when users gather in the same vicinity, as in public transportation, LTE network data can be efficiently offloaded and multicasted through Wi-Fi for e.g. delivering traffic-related information and for the benefit of infotainment service consumers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.419-420
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• 2008

In this work, we report several experimental data capable of evaluating the phase transition characteristics of (InTe)x(GeTe)y (x = 0.1, 0.3, y =1) pseudo-binary thin films. (InTe)x(GeTe)y phase change thin films have been prepared by thermal evaporator. The crystallization characteristics of amorphous (InTe)x(GeTe)y thin films were investigated by using nano-pulse scanner with 658 nm laser diode (power : 1~17 mW, pulse duration : 10~460 ns) and XRD measurement. It was found that the crystalline speed of In-Ge-Te thin films are faster than $Ge_2Sb_2Te_5$[1] and also the crystalline temperature is higher. Changes in the optical transmittance of as-deposited and annealed films were measured using a UV-VIS-IR spectrophotometer and four-point probe was used to measure the sheeresistance of InGeTe films annealed at different temperature.

• Magazine of the Korea Concrete Institute
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• v.2 no.1
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• pp.79-90
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• 1990

The purpose of this paper is to study on the effect of cutting off tension bars in reinforced concrete beams. that is, the ultimate strength, the failure mode and thl} tension stress distribution through the span. To achieve this purpose, a full-scale frame and seven small scale model beams (five rectangular and two T-section beams) were tested. The four main model specimens and two speciml}ns without cutting off tension bars 1,'{ere analyzed as plane stmss element with package program ADINA. As a result of test and analysis, the shorter' distance bet ween the reaction point and the cutting off point, the higher the ultimate strength of a bl}am will be when other physical properties are equal.

• Preventive Nutrition and Food Science
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• v.19 no.2
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• pp.75-81
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• 2014

This study was conducted to investigate the effects of cranberry power on antioxidant defense system in rats fed an atherogenic diet and injected with lipopolysaccharide (LPS). Sprague-Dawley rats were divided into the following 5 groups: normal diet+saline (NS), atherogenic diet+saline (AS), atherogenic diet+LPS (AL), atherogenic diet with 5% cranberry powder+LPS (AL-C5), and atherogenic diet with 10% cranberry powder+LPS (AL-C10). Total antioxidant status measured by ferric reducing ability of plasma (FRAP) was significantly reduced by LPS injection (24%) and was restored by the cranberry powder treatment (P<0.05). In addition, the mean level of plasma total phenolics was significantly decreased by LPS injection (P<0.05) and tended to be increased when cranberry powder was incorporated in to the diet. Activity of serum superoxide dismutase (SOD) tended to be lowered by LPS injection and declined further in cranberry powder fortified groups. Overall results indicate that dietary cranberry powder may provide appropriate antioxidants to counter the diminished antioxidant status induced by exposing hypercholesterolemic rats to LPS.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.3
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• pp.834-845
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• 1995

An experimental study is made in a nearly two-dimensional 90.deg. curved duct to investigate the effects of interaction between streamline curvature and mean strain on turbulence. The initial shear at the entrance to the curved duct is varied by an upstream shear generator to produce five different shear conditions ; a uniform flow (UF), a positive weak shear (PW), a positive strong shear(PS), a negative weak shear (NW) and a negative strong shear(NS). With the mean field data of the case UF, variations of the momentum thickness, the shape factor and the skin friction over the convex(inner) surface and the concave (outer) surface are scrutinized quantitatively in-depth. It is found that, while the pressure loss due to curvature is insensitive to the inlet shear rates, the distributions of wall static pressure along both convex and concave surfaces are much influenced by the inlet shear rates.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.379-381
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• 2002

A single CdZnTe detector is tested for suitability in a prototype CT/ SPECT system designed to acquire both emission and transmission data. The detector has the size of 1${\times}$l-cm$^2$ with 4${\times}$4 1.5${\times}$l.5mm$^2$ pixellated anodes. Since the detector is smaller than imaged object, we translated it in an arc centered at the x-ray tube to image larger objects. Pulse counting electronics with very short shaping time (50 ns) are used to satisfy high photon rates in x-ray imaging, and response linearity up to 3${\times}$10$\^$5/ counts per second per detector element is achieved. The energy resolution of 122-keV gamma-ray is measured to be 14%. We have characterized the system performance by scanning a radiographic resolution phantom .and the Hoffman brain phantom. The spatial resolution of CT and SPECT are about 1 mm and 7 mm, respectively.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.2
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• pp.94-99
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• 2014

In this study, using AlN materials produced by two different sintering techniques, grinding experiments were performed under various grinding conditions, including different table speeds and cut depths. In order to measure the grinding force, a tool dynamometer was used. Surface roughness measurements and a digital microscope were also was used. The grinding forces were higher at a higher table speed and a higher cut depth. The experimental results show that the grinding characteristics of the two workpieces are similar.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.6
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• pp.48-55
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• 2008

We have simulated the performance of a simple engine model with a gas turbine engine simulation program based on CFD. 2-dimensional Navier-Stokes code for the viscous flow was applied to simulate a compressor and a turbine, and the chemical equilibrium code with the lumped method was applied to simulate the combustor. Unsteady-flow phenomenon between rotor and stator of the compressor and the turbine was analyzed by steady mixing-plane method. In this way, the influence of the turbine blade pitch on the engine was investigated. It was shown that the compressor is operated at more higher pressure conditions as narrower the pitch distance of the turbine.