• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.743-747
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• 2003

The improvement of luminance and luminous efficiency is the one of the most important part in AC-PDPs. To achieve high luminance and luminous efficiency, high VUV emission efficiency is needed. We measured the emission spectra of vacuum ultraviolet(VUV) and infrared(IR) rays in surface discharge AC-PDP with Ne-Xe mixture gas. The influence of Ne-Xe gas-mixture ratio on resonance state $Xe^{\ast}(3P_{1})$ and exited state $Xe^{\ast}(3P_{2})$ has been investigated. It is found that the intensity of VUV 147nm emission is proportional to that of the IR 828 nm emission, and the VUV 173nm emission is roughly proportional to that of the IR 823nm emission. The electron temperature and plasma density have been experimentally measured from the center of sustaining electrode gap by a micro Langmuir probe in AC-PDPs. The plasma density from the center of sustaining electrode gap are shown to be maximum value of $9{\times}10^{11}cm^{-3}$, where the electron temperature is about 1.6 eV in this experiment

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.400-403
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• 2008

We have investigated the electro-optical characteristics of AC-PDP with different MgO protective layers, which have been deposited by electron beam evaporation from various sintered pellets with different temperatures. We have measured the secondary electron emission coefficient ($\gamma$) by using the Gamma Focused Ion Beam ($\gamma$-FIB) system, the static margin, and the address delay time. Also, we have investigated photoluminescence (PL) characteristics for understanding the energy levels of MgO pellets and protective layers.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.141-141
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• 2013

We have generated the needle-typed nonthermal plasma jet by using an Ar gas flow at atmospheric pressure. Diagnostics of electron temperature anddensity is critical factors in optimization of the atmospheric plasma jet source in accordance with the gas flow rate. We have investigated the electron temperature and density of plasma jet by selecting the four metastable Ar emission lines based on the atmospheric collisional radiative model and radial profile characteristics of current density, respectively. The averaged electron temperature and electron density for this plasma jet are found to be ~1.6 eV and ~$3.2{\times}10^{12}cm^{-3}$, respectively, in this experiment. The densities of OH radical species inside the various bio-solutions are found to be higher by about 4~9 times than those on the surface when the argon bioplasma jet has been bombarded onto the bio-solution surface. The densities of the OH radicalspecies inside the DI water, DMEM, and PBS are measured to be about $4.3{\times}10^{16}cm^{-3}$, $2.2{\times}10^{16}cm^{-3}$, and $2.1{\times}10^{16}cm^{-3}$, respectively, at 2 mm downstream from the surface under optimized Ar gas flow 250 sccm.

• Journal of the Korean Wood Science and Technology
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• v.16 no.3
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• pp.22-37
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• 1988

In tendancy of manufacturing beam with laminating particleboard, it was thought that if the properties, especially mechanical properties, of particleboard be reinforced, the mechanical properties of particleboard-laminated beam would be also improved. So in this study the particleboard was reinforced with composing of wood particle and steel wire. This study was carried out to obtain the basic physical and mechanical properties of board composed of wood particle and steel wire, especially tensile strength and compressive strength which are the important factors of the lamina of beam, in order to estimate whether the board, composed of wood particle and steel wire could be to improve the properties of the particleboard- laminated beam. The results obtained were summarized as follows: 1. The board composed of wood particle and steel wire in accordance with lower board density took better thickness swelling. 2. The board with lower board density was improved in higher value of tensile strength with more steel wires in prescribed cross section area of the board. for example, the board of density 0.5 showing 140% improved value. 3. In compressive strength, the board with lower board density was also improved in hjgher value with more steel wires in prescribed cross section area.

• Particle and aerosol research
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• v.6 no.3
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• pp.139-145
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• 2010

In this study, we investigated the particle formation during the deposition of borophosphosilicate glass (BPSG) and phosphosilicate glass (PSG) films in thermal chemical vapor deposition reactor using in-situ particle monitor (ISPM) and particle beam mass spectrometer (PBMS) which installed in the reactor exhaust line. The particle current and number count are monitored at set-up, stabilize, deposition, purge and pumping process step in real-time. The particle number distribution at stabilize step was measured using PBMS and compared with SEM image data. The PBMS and SEM analysis data shows the 110 nm and 80 nm of mode diameter for BPSG and PSG process, respectively.

• Journal of the Semiconductor & Display Technology
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• v.3 no.2
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• pp.5-9
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• 2004

Microcircuit fabrication requires precise control of impurities in tiny regions of the silicon. These regions must be interconnected to create components and VLSI circuits. The patterns to define such regions are created by lithographic processes. In order to image features smaller than 70 nm, it is necessary to employ non-optical technology (or next generation lithography: NGL). One such NGL is extreme ultra-violet lithography (EUVL). EUVL transmits the pattern on the wafer surface after reflecting ultra-violet through mask pattern. If particles exist on the blank mask, it can't transmit the accurate pattern on the wafer and decrease the reflectivity. It is important to care the blank mask. We removed the particles on the wafer using focused ion beam (FIB). During removal, FIB beam caused damage the multi layer mask and it decreased the reflectivity. The relationship between particle removal and reflectivity is examined: i) transmission electron microscope (TEM) observation after particle removal, ii) reflectivity simulation. It is found that the image mode of FIB is more effective for particle removal than spot and bar mode.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.3
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• pp.315-321
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• 2001

Aerodynamic lenses are widely used in generating particle beams of high density and small diameter, but analytical or modeling studies are limited only in the free molecular regime. In this study, it is shown that generating particle beam is also possible in atmospheric pressure range, and the mechanism of generating particle beam using an orifice is analysed into three different parts : fluid dynamic contraction, diffusional defocusing, and inertial focusing. In laminar flow conditions, the diffusional defocusing effect can be neglected, and the effects of inertial focusing can be expressed in terms of the orifice size and Stokes number. Numerical experiments are done for two different orifices, d/D=1/5 and 1/10 and particle diameter d(sub)p=1-10 ㎛. The results for two different orifices can be made into a single curve when a modified Stokes number is used. The inertial focusing effect diminishes when the modified Stokes number becomes smaller than 10(sup)-2.

• Journal of Electrochemical Science and Technology
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• v.6 no.3
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• pp.75-80
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• 2015

We introduce a new synthesis method to prepare small TiO₂ nanoparticles with a narrow particle size distribution, which is achieved by electron beam (E-beam) irradiation. The effects of E-beam irradiation on the synthesis of TiO₂ nanoparticles and the electrochemical performance of TiO₂ nanoparticles as alternative anode materials for Li-ion batteries are investigated. The TiO₂ nanoparticles induced by E-beam irradiation present better cycling performance and rate capability than the TiO₂ nanoparticles synthesized by normal hydrolysis reaction. The better electrochemical performance is attributed to small particle size and narrow particle size distribution, resulting in the large surface area that provides innumerable reaction sites and short diffusion length for Li⁺ through TiO₂ nanoparticles.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.12
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• pp.2322-2329
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• 2008

In this study, we introduce the design methodology of an optimized fuzzy cascade controller with the aid of particle swarm optimization(PSO) for ball & beam system. The ball & beam system consists of servo motor, beam and ball, and remains mutually connected in line in itself. The ball & beam system determines the position of ball through the control of a servo motor. We introduce the fuzzy cascade controller scheme which consists of the outer(1st) controller and the inner(2nd) controller as two cascaded fuzzy controllers, and auto-tune the control parameters(scaling facrors) of each fuzzy controller using PSO. For a detailed comparative analysis from the viewpoint of the performance results and the design methodology, the proposed method for the ball & beam system which is realized by the fuzzy cascade controller based on PSO, is presented in comparison with the conventional PD cascade controller based on serial genetic alogritms.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.252-254
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• 2002

A new protocol for dosimetry in external beam radiotherapy is published by the Japan Society of Medical Physics (JSMP) in 2002. The protocol deals with proton and heavy ion beams as well as photon and electron beams, in accordance with IAEA Technical Report Series No. 398. To establish inter-institutional uniformity in proton beam dosimetry, an intercomparison program was carried out with the new protocol. The absorbed doses are measured with different cylindrical ionization chambers in a water phantom at a position of 30-mm residual range for a proton beam, that had range of 155 mm and a spread out Bragg peak (SOBP) of 60-mm width. As a result, the intercomparison showed that the use of the new protocol would improve the +/- 1.0 % (one standard deviation) and 2.7 % (maximum discrepancy) differences in absorbed doses stated by the participating institutions to +/- 0.3% and 0.9 %, respectively. The new protocol will be adopted by all of the participants.