• Proceedings of the Korean Vacuum Society Conference
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• 2007.02a
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• pp.175-175
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• 2007

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.19-28
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• 2005

Passive microwave remote sensing technique have shown great potential for mon monitoring regional/global surface soil moisture. Given a single measurement at dual polarization/single frequency/single view angle, a strategic approach to artificially generating multiple microwave brightness temperatures is presented. And then the statistically generated microwave brightness temperature data are applied to the inverse algorithm, which mainly relies on a physically based microwave emission model and an advanced single-criterion multi-parameter optimization technique, to simultaneously retrieve soil moisture and vegetation characteristics. . The procedure is tested with dual polarized Tropical Rainfall Measurement Mission Microwave Imager (TRMM/TMI) over two different cover sites in Oklahoma and Beltsville field experimental data. The retrieval results are analyzed and show excellent performance.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.6
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• pp.1203-1210
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• 2001

This study was carried out to develop an engine for off-road vehicles especially for farm tractors using the liquefied petroleum gas (LPG) which is known as a source of energy having good potential of substitute fuel for diesel engine because of its economical advantage and low pollutant materials after combustion. The study was focused on develop an engine of high in specific power output, low in specific fuel consumption and emission of pollutants. A series of teat was dope on the engine - various laboratory tests to analyze performance of the engine and actual field tests with the engine installed on a farm tractor as a power source.

• ALGAE
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• v.20 no.4
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• pp.305-314
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• 2005

5 Haptophyta 2 Chrysophyta and 1 Prasinophyta species of scale-bearing nanoflagellates were collected in coastal water of Korea and identified by examination of their scales with Field Emission Scanning Electron Microscope (JSM-6700F). These included Chrysochromulina ahrengoti, C. simplex, C. spinifera, Prymnesium parvum, P. patelliferum, Mamiella gilva, Paraphysomonas imperforata and Pa. vestita. The surface of cells covered with unmineralised scales (5 Haptophyte and 1 Prasinophyta species) or silica scales (2 Chrysophyta species). Scale-covered flagella are found in the 1 Prasinophyta species. One of the main structural characteristics of Haptophyte is the haptonema, a filiform organelle which occurs together with the two flagella. It may be long and coiling upon irritation as in Chrysochromulina, or short and noncoiling as in Prymnesium.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.729-732
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• 2001

In this study, the effect of oxygen partial pressure on the electrical properties of vanadium oxide(VO$_{x}$) thin films were investigated. The thin films were prepared by r.f. magnetron sputtering from V$_2$O$_{5}$ target in a gas mixture of argon and oxygen. The oxygen partial pressure ratio is changed from 0% to 8%. I-V characteristics were distinguished between linear and nonlinear region. In the low field region the conduction is due to Schottky emission, while at high fields it changes to Fowler-Nordheim tunneling type conduction. The conductivity measurements have shown an Arrhenius dependence of the conductivity on the temperature.ure.

• Journal of the Korean Vacuum Society
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• v.8 no.4A
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• pp.465-469
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• 1999

In this paper, spacer process for FED (Field Emission Display ) was developed with the glass to glass anodic bonding technology using Al film as an interlayer. Characteristics, current density-time curves and force of the anodic boding were measured on various thickness of Al film; 1000$\AA$, 2000$\AA$, 3000$\AA$, 4000$\AA$ and 500$\AA$. Holders for spacer were fabricated with photosensitive glass and (110) Si wafer by bulk micromachining. Spacers was formed on glass substrate by spacer glass to glass anodic bonding and an evacuated panel was fabricated to prove the potential of application for FED.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1470-1473
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• 2005

We proposed new triode-type Field Emitter Arays using Carbon NanoTubes(CNT-FEAs) as electron emission sources at low electric fields. The CNTs were selectively grown on the patterned catalyst layer by Plasma-Enhanced Chemical Vapor Deposition (PECVD). In this structure, gate electrodes are located underneath the cathode electrodes and extracted gate is surrounded by CNT emitters. Furthermore, in order to control density of CNTs, we investigated effect of using rapid thermal annealing (RTA).

• Journal of Mechanical Science and Technology
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• v.17 no.9
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• pp.1371-1379
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• 2003

The effects of change in injection pressure on spray structure in high temperature and pressure field have been investigated. The analysis of liquid and vapor phases of injected fuel is important for emissions control of diesel engines. Therefore, this work examines the evaporating spray structure using a constant volume vessel. The injection pressure is selected as the experimental parameter, is changed from 22 MPa to 112 MPa using a high pressure injection system (ECD-U2). Also, we conducted simulation study by modified KIVA-II code. The results of simulation study are compared with experimental results. The images of liquid and vapor phase for free spray were simultaneously taken by exciplex fluorescence method. As experimental results, the vapor concentration of injected fuel is leaner due to the increase of atomization in the case of the high injection pressure than in that of the low injection pressure. The calculated results obtained by modified KIVA-II code show good agreements with experimental results.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1059-1064
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• 2003

This paper presents an overview of the mechanical properties of carbon nanotubes. The characteristics of carbon nanotubes were briefly introduced. We then present briefly the experimental techniques used to measure mechanical properties and the results obtained by other researchers. A carbon nanotube is too small to be pulled apart with standard tension devices. Manipulators should be used for mechanical testing. We introduced manipulation methods using nanomanipulators under field-emission scanning-electron microscope.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.3
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• pp.76-82
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• 1999

This study was carried out to verify finding performance of dental diamond bur and investigate the possibility of AE application in density field. Work pieces were made of acryl and bovine respectively for the experiments in this study. Grinding test was conducted to get the data of grinding resistance and specific finding energy of low different types of diamond bur by using tool dynamometer. AE signal was acquired to verify grinding process in the AE measuring system. AErms value was increased as the grinding velocity and depth were increasing, but it decreased as the feed rate was increasing. The case of the small value of AE signal is due to abnormal grinding in D type diamond bur. By analyzing AErms start and finish time of grinding working, abnormal grinding state can be confined. Abnormal state can be found through the behavior of AE signal in the finding working. As a result, it is expected that forecast of abnormal state is possible using AE equipments under real time process.