STI CMP process are substituting gradually for LOCOS(Local Oxidation of Silicon) process to be available below sub-0.5um technology and to get planarized. The other hand, STI CMP process(especially STI CMP with RIE etch back process) has some kinds of defect like Nitride residue, Torn Oxide defect, etc. In this paper, we studied how to reduce Torn Oxide defects after STI CMP with RIE etch back process. Although Torn Oxide defects which occur on Oxide on Trench area is not deep and not sever, Torn oxide defects on Moat area is sometimes very deep and makes the yield loss. We did test on pattern wafers witch go through Trench process, APCVD process, and RIE etch back process by using an REC 472 polisher, IC1000/SUV A4 PAD and KOH base slurry to reduce the number of torn defects and to study what is the root causes of torn oxide defects.

Optical and electrical properties of GaSe:$Er^{3+}$ single crystals grown by the Bridgeman technique was been investigated by using optical absorption and Hall-effect measurements. The Hall coefficients were measured by using a high impedance electrometer in the temperature range from 360K to 150K. The temperature dependence of hole concentration shows the characteristic of a partially compensated p-type semiconductor. carrier density($N_H$) of GaSe doped with Erbium was measured about $3.25{\times}10^{16}\;[cm^{-3}}$ at temperature 300K, which was high than undoped specimen. Photon energy gap ($E_{gd}$) was measured about 1.7geV.

Surface passivation using glass powders results in good reliability for high voltage silicon power devices. In this paper, Zinc borosilicate glass was prepared for the purpose of passivating, and a deposition technique of glass films on the silicon surface by electrophoresis in which acetone is used as a suspension medium and a measurement technique of C-V curve has been investigated. Properties were compared using SEM, XRD, C-V Curve as a function of firing condition, temperature and atmosphere were investigated. Under 100V applied, 1 minute, $700^{\circ}C$ firing temperature, and $O_2$ atmosphere, I can get the fine films $5.8{\mu}m$ thickness with Zinc borosilicate glass. As a result of investigation of glass films, it has been found that pre-firing and annealing play an important role to achieve uniform, fine, reliable glass deposition films and Glass/Silicon interlace.

Metal thin films such as aluminum have been used as interconnects in semiconductor device. Recently, these materials are applied to structural materials in microsensors and microactuators. In this study, we evaluate deformation and strength behavior of aluminum alloy film. Three layer model for thermal deformation of multilayered thin film material is introduced and applied to Si/Al(1%Si)/$SiO_2$ system. Based on beam bending theory and concept of bending strain. elastic and elastic/plastic thermal deformation behaviors of multilayered materials can be estimated. In the case of plastic deformation of ductile layer, strain rate equations based on deformation mechanism map are employed for describe the stress relaxation effect. To experimentally examine deformation of multilayered thin film materials, in-situ laser scanning method is used to measure curvature of specimens during heating and cooling. The thickness of $SiO_2$ layer is varied to estimate third-layer effect of thermal deformation of metal films, and its effect on deformation behavior are discussed.

Reduction of hot carrier degradation in MOS devices has been one of the most serious concerns for MOS-ULSIs. In this paper, three types of LDD structure for suppression of hot carrier degradation, such as spacer-induced degradation and decrease of performance due to increase of series resistance will be investigated. LDD-nMOSFETs used in this study had three different drain structure. (1) conventional ${\underline{S}}urface$ type ${\underline{L}}DD$(SL), (2) ${\underline{B}}uried$ type ${\underline{L}}DD$(BL), (3) ${\underline{S}}urface$urface ${\underline{I}}mplantation$ type LDD(SI). As a result, the surface implantation type LDD structure showed that improved hot carrier lifetime to comparison with conventional surface and buried type LDD structure.

Gate insulators using various fluoride films were investigated for thin film transistor applications. Conventional oxide containing materials exhibited high interface states, high $D_{it}$ gives an increased threshold voltage and poor stability of TFT. To improve TFT performances, we must reduce interface trap charge density between Si and gate insulator. In this paper, we investigated gate insulators such as such as $CaF_2$, $SrF_2$, $MgF_2$ and $BaF_2$. These materials exhibited an improvement in lattice mismatch, difference in thermal expansion coefficient, and electrical stability MIM and MIS devices were employed for an electrical characterization and structural property examination. Among the various fluoride materials, $CaF_2$ film showed an excellent lattice mismatch of 0.737%, breakdown electric field higher than 1.7MV/cm and leakage current density of $10^{-6}A/cm^2$. This paper probes a possibility of new gate insulator material for TFT application.

In this paper, we described the effect of rapid thermal annealing on the electrical properties of interfacial layer between various top electrodes and $(Ba_{0.5}Sr_{0.5})TiO_3$ thin films. BST thin films were fabricated on Pt/TiN/$SiO_2$/Si substrate by RF magnetron sputtering technique. AI, Ag, and Cu films for the formation of top electrode were deposited on BST thin films by thermal evaporator. Top electrodes/BST/Pt capacitor annealed with rapid thermal annealing at various temperature. In $(Ba_{0.5}Sr_{0.5})TiO_3$ thin films with Cu top electrode annealed at $500^{\circ}C$, the dielectric constant was measured to the value of 366 at 1.2 [kHz] and the leakage current was obtained to the value of $5.85{\times}10^{-7}\;[A/cm^2}$ at the forward bias of 2 [V].

SCT thin films were deposited with substitutional contents of Ca using RF magnetron sputtering method, and the structural and dielectric properties are investigated. SEM and XRB were examined to analysis of structural characteristics. The crtstallinity of SCT thin films and dielectric constant were increased at Ca 15[mol%]. While, it was decreased when the substitutional contents of Ca exceed over 15[mol%].

Thin films of vanadium pentoxide ($V_{2}O_{5}$) have been deposited by r.f. magnetron sputtering from $V_{2}O_{5}$ target in gas mixture of argon and oxygen. Crystal structure, surface morphology, surface composition and optical properties of films prepared under different substrates are characterized through XRD, SEM, AES, XPS and optical absorption measurements. The films prepared below $100^{\circ}C$ are amorphous, and those prepared above $200^{\circ}C$ are polycrystalline. Thermally Induced oxidation of films into higher oxide has been observed with increasing substrate temperature. Vanadium oxide films show two optical absorption bands indicating the presence of direct and indirect transitions.

In this study, the wind-mill type ultrasonic motor was fabricated, and then revolution and temperature characteristics of the ultrasonic motor were measured. Brass metal was pressed with umbrella-type using metal mold, then slot of 4 kind was processed in each of thickness. Among sixteen's ultrasonic motors, heat loss on applied voltage was much at stator of the highest resonant point, but heat loss on applied voltage was almost neglected at the lowest resonant point of stator. The thickener thickness of elastic body, revolution speed was decreased. The more slot of elastic body, revolution speed was increased. Applied voltage was changed from $10V_{max}$ to $100V_{max}$. When applied voltage was under $20V_{max}$, ultrasonic motor was not rotated. When applied voltage was over $90V_{max}$, revolution of ultrasonic motor was saturated. Maximum revolution speed was 510[rpm].

$Ba(Mg_{(1-x)}Co_x)_{1/3}(Ta_{(1-x)}Nb_x)_{2/3}O_3$ ($x=0.3{\sim}0.6$) ceramics were prepared by the conventional mixed oxide method. The sintering temperature and time were of $1400{\sim}1575[^{\circ}C]$,5[hr.] respectively. The structural and microwave dielectric Properties were investigated with composition ratio and sintering temperature. And then the application for the microwave dielectric resonator was investigated.

The thermally stimulated current (TSC) of PVDF thin film prepared by physical vapor deposition method was investigated. PVDF shows three TSC peaks designated $P_1$, $P_2$ and $P_3$ in ascending order of temperature. The $P_1$ peak is associated with water in the PVDF specimen. $P_2$ and $P_3$ Peaks are specific peaks of $\alpha$ and $\beta$ type PVDF, respectively. The peak temperature was shifted to higher temperature, and peak intensity was decreased with increasing substrate temperature under thin film preparation.

This paper provides the results of performance investigation of gas insulated switches(G/S) for distribution power system. In order to investigate anti-contamination capability of G/S we carried out electrical tests and material analysis on the body of G/S and it's accessories. Through this experiment we found out the lead cable of G/S had not anti-contamination capability and G/S had insufficient interval between each phase. In order to improve the performance of G/S for heavy contamination area it is indispensable to replace the lead cable to the new cable which has anti-contamination ability.

In this paper, Co-Cr thin films which are known for a excellent perpendicular magnetic recording media were prepared. Changing target- substrate distance, Ar gas pressure and arriving atoms, the incident angle and c-axis orientation properties by using the facing targets sputtering system. We evaluated the c-axis dispersion angle by measu ring half-height width with Micro area X-Ray Diffractometer, measured the thickness of thin film with Ellipsometer. The magnetic properties were compared measuring in-plane squareness and perpendicular coercivity with vibrating sample Magnetometer.

An evaluation method for oxygen permeable characteristics of the membrane covering to each cathode of multiple cathode - single anode type dissolved oxygen sensor, which has high reproducibility and is capable of measuring multiple components in solutions. For this purpose, a measuring circuit for the multiple cathode type DO sensor was designed to lower the noise signal by adapting a digital LPF to readout the sensor output accurately. Digital LPF is designed by setting up the transfer function to set the cutoff frequency to 10Hz, and the transfer function is programmed by C language, and then the filtering characteristics are evaluated with the simulation and experiments. Using this LPF added measuring circuit for the multiple cathode type DO sensor, we have obtained the calibration factor for each cathode to calibrate the variation of the output signals. The calibration factor was obtained by measuring the sensor output signal followed by oxygen partial pressure, using the same oxygen permeable membrane at each cathode of the multiple cathode type DO sensor.

Using the R/V converting circuit, hydrogen detecting characteristics of the $WO_3$ films were investigated. The R/V converting circuit is configured with the equivalently constant current driving method connecting an unknown resistor to be measured in the feedback loop of the or-amr rather than using a separated constant current circuit. The response time of the reference voltage for the R/V converting circuit was simulated by the circuit simulator "SABER", and it was found that the response time in the high resistance range become longer and the error amounts to 10%. From the simulation results. replacing the capacitor in the feedback loop of the second stage or-amp with a 0.001uF capacitor, when measuring in the high resistance range, the response characteristics are remarkably improved. The response time was shortened from about 10 seconds to below 1 second. Using this circuit, the effect of $WO_3$ films deposited by sputtering method on hydrogen was measured.

The highest etch rate of Pt film was obtained at 10% $Cl_2$/90% Ar gas mixing ratio in our previous investigation. However, the problems such as the etch residues(fence) remained on the pattern sidewall, low selectivity to oxide as mask and low etch slope were presented. In this paper, the etching by additive $O_2$ gas to 10% $Cl_2$/90% Ar gas base was examined. As a result, the fence-free pattern and high etch slope was observed and the selectivity to oxide increased without decreasing of the etch rate. And the reasons for this phenomenon was investigated by XPS(x-ray photoelectron spectroscopy) surface analysis and plasma characteristic.

This paper describes the highly sensitive Si Hall magnetic sensing system which can measure the earth magnetic field. Generally, the important parameters in Hall device which degrade the ability of magnetic detection are offset voltage and 1/f noise. The offset voltage and 1/f noise in Hall plates can be reduced by spinning current method. In this paper, we implement the highly sensitive Si Hall magnetic sensing system using spinning current method. As a result, the minimum detectable magnetic field is 0.1G.

Electrical and optical characteristics of Powder type EL display(P-ELD) in this study are described, In experimental results of V-J, current are increased with increasing the frequency and voltage. Luminance was increased with frequency. This is due to the positive space charge formed to cathode region. Lumiance at 150V, 20 kHz has $840\;cd/m^2$. This tendency is due to the decrease of capacitive reactance in insulator layer. Uniformity of P-ELD shows 97%. CIE chromaticity with increasing frequency are shifted toward blue color. It can be explained in tenn of the difference of recombination energy.

Electroluminescence is occurred by electric filed located in the phosphor. Until now most of EL researched have been studied the characteristics of devices that drive over 400Hz and commercialized, but in Problems of life time, natural aging increased with behavior of high frequency in the phosphor. In this paper, we investigated the luminescence characteristics were driven by low frequency($0{\sim}100Hz$). Moreover, we Presented the improvement way in the method device production and drive power as measurement at commercial frequency(60Hz).

In this study the emission characteristics of Sq dye undoped and doped specimen investigated. In Sq 14mol% doped specimen, OXD7 and Alq3 layer interpolated. This effect has been observed and mechanism characteristics have been examined. For OXD7 insert, hole flow the cathode intercept, and then hole accumulated. Because of increasing recombination probability of electron and hole highly pure color maintained. Simultaneously brightness characteristics and emission efficiency could improve.

Synthetic diamond films were deposited on pretreated silicon substrate in activated gas phase using RF plasma-assisted CVD. We investigated the influence of $O_2$ gas on facets of diamond crystal. In $H_2-CH_4-O_2$ gas mixture, the increase of oxygen concentration lead to well-faceted diamond particles and increasing crystallinity of diamond films. The deposited diamond films were analyzed by SEM, XRD, Raman spectroscopy.

Numerical simulation has been performed on a microtip field emitter structure produced by employing a CMP technology. The field distributions are estimated by using a Maxwell 2D vector simulator and the electron trajectories are obtained by solving the equation of ballistic motion of emitted electrons. The beam width observed at the phosphor has been characterized as a function of the applied voltages and the gate-to-tip distance. It has also been investigated how the electron trajectory is changed by adopting the anode switching as well as the focus electrode.

The TPD and the $Alq_3$ film are widely used as a hole transport layer and an emitter layer respectively, in organic electroluminescent(EL) device (ITO Glass/TPD/$Alq_3$/metal). In this structure, we fabricated two models. Model(1) having ITO glass/$Alq_3$/Al structure and model(2) having ITO Glass/TPD/$Alq_3$/Al structure were fabricated by the vacuum evaporation. The comparison between model(1) and model(2) was made about the absorbance, the wave length, the current-voltage characteristic and the ln I - $V^{(1/2)}$characteristic respectively. Electroluminescence of green and wavelength of 510[nm] were observed in both model. We observed absorbance from 320[nm] to 430[nm] in $Alq_3$ material and from 250[nm] to 400[nm] in TPD material.

A $BaTiO_3$, ferroelectric material, was mixed $SrTiO_3$, $(x)BaTiO_3-(1-x)SrTiO_3$($0.7{\leq}x{\leq}1$) ceramic capacitor with stable electrical properties in high voltage was fabricated. And microstructure, electrical property were investigated with $SrTiO_3$ mol ratio. The shrinkage, open porosity, sintering density were predominated at $9BaTiO_3-0.1SrTiO_3$. Increasing $SrTiO_3$ mol ratio, curie temperature was shifted at low temperature and maximum permittivity was increased. Also, $0.9BaTiO_3-0.1SrTiO_3$ was showed stable dielectric properties at $25{\sim}80[^{\circ}C]$. V-I properties of specimen were observed in the temperature range of $21{\sim}143[^{\circ}C]$, were divided into three regions. The region I below 10[kV/cm] was shown Ohmic conduction, the region II from 10 to 30[kV/cm] was explained by the Poole-Frenkel emission theory and the region III above 30[kV/cm] was analysed by the tunneling effect.

(Ba,Sr)$TiO_3$ thin films were etched with $Cl_2$/Ar gas mixing ratio in an inductively coupled plasma (ICP) by varying the etching parameter such as f power, do bias voltage, and chamber pressure. The etch rate was $560{\AA}/min$ under Cl_2/(Cl_2+Ar)$ gas mixing ratio of 0.2, rf power of 600 W, do bias voltage of 250 V, and chamber pressure of 5 mTorr, At this time, the selectivity of BST to Pt, $SiO_2$ was respectively 0.52, 0.43. The surface reaction of the etched (Ba,Sr)$TiO_3$ thin films was investigated with X-ray photoelectron spectroscopy (XPS).

We investigated Pt and $RuO_2$ as a bottom electrode and PZT thin film for ferroelectric applications. XRD examination shows that a mixed phase of (111) and (200) Pt peak for the temperature ranged from RT to $200^{\circ}C$, and a preferred (111) orientation for the substrate temperature of $300^{\circ}C$. From the XRD and AFM results, we recommend the substrate temperature of $300^{\circ}C$, 80 W for the Pt bottom electrode growth. From the study of an oxygen partial pressure from 0 to 50%, we learned that only Ru metal was grown with $0{\sim}5%$, a mixed phase of Ru and $RuO_2$ for $10{\sim}40%$, pure $RuO_2$ at 50%. Having optimized the bottom electrode growth conditions, we employed two step process in PZT film capacitor: PZT film growth at the low substrate temperature of $300^{\circ}C$ and then post RTA anneal treatments. PZT films were randomly oriented on $RuO_2$ and (110) preferentially oriented on Pt electrode. Leakage current density of PZT film demonstrated two to three orders higher for $RuO_2$ bottom electrode. From C-V results we observed a dielectric constant of PZT film higher than 1200. This paper presents the optimized process conditions of the bottom electrodes and properties of PZT thin films on these electrodes.

In this study, piezoelectric composites with 1-3-0 connectivity have been studied. A Piezoelectric ceramic PZT Prepared by Wet-Dry Combination method is used as a filler in mixture of Eccogel polymer matrix and third Phase. The density and stiffness of 1-3-0 type composites were decreased with increasing the third phase.

We give pressure stimulation into organic thin films and detect the induced displacement current, In processing of a device manufacture, we can see the process is good from the change of a surface pressure for organic thin films and transfer ratio of area per molecule. The structure of manufactured device is Au/organic thin films(Kapton-Polyimide)/Au and I-V properties of the device is measured from 0(V) to +5(V). The maximum value of measured current is increased as the number of accumulated layers are decreased. The resistance for the number of accumulated layers, the energy density for an input voltage show desired results.

We studied on the $\pi$-A isotherm of the L-$\alpha$-DLPC was measured at the air-water interface varying with the compressing speed and amounts of solutions for spreading. The molecular arrangement of deposited films were evaluated by measuring the absorption with the UVspectrometer. We made structures of metal(Au)/organic thin films (L-$\alpha$-DLPC)/Metal(Au), the number of accumulated layers are 3. And I-V characteristic of the device examined.

In order to analyse the degradation process of epoxy/glass fiber for outdoor condition, FRP laminate was exposed to the wavelength of ultraviolet rays and evaluated by comparing contact angle, surface resistivity, surface potential decay, and ESCA spectrum respectively. Finally, We can conclude that the degradation phenomena on the surface of epoxy composites are dominated by the induction of ester and carboxyl groups.

In this paper Polyimide(PI) thin film are fabricated by vapor deposition polymerization(VDP) of dry process which are easy to control the film's thickness and hard to pollute due to volatile solvent. The FT-IR spectrum show that PAA thin films fabricated by VDP are changed to PI thin film by thermal curing. From AFM(Atomic Force Microscopy) experimental as the higher curing temperature. the thin film thickness decreases and roughness decresse.

Arachidic acid(AA) was used as LB films and its dielectric and conduction characteristics were investigated. The relative dielectric constant(${\varepsilon}_{LB}$) of AA LB films obtained from capacitance-frequency properties was about $3.5{\sim}4.1$. And the conductivity(${\sigma}_{LB}$) of AA LB films obtained from Current-Voltage characteristics was about $2.6{\times}10^{-15}[S/cm]$. Also, the conduction mechanism of current in LB films was dependant on Schottky type and the barrier height obtained from Schottky plot was about 1.4[eV].

The lithium polymer battery with polymer electrolyte is expected as a safe and long cycle life battery. This paper reports primarily the recent development results of a solid polymer electrolyte, which is a key point of the secondary battery system. The new type of polymer electrolyte was prepared under a dry Ar atmosphere by dissolving $LiCIO_4$ in a matrix of EC, PC and then dispersing polyacrylonitrile(PAN). Also adding some inorganic filler $Al_2O_3$. The dispersed solution heated at $120^{\circ}C$. The polymer electrolyte were characterized by EIS(Electrochemical Impedance Spectroscopy), TGA(Thermo Gravimetric analysis), DMA(Dynamic Mechanical Analyzer), DSC (Differential Scanning Calorimetry). The lithium ion yield is 0.29 when PAN-$Al_2O_3$ which was applied DC 5mV. The ionic conductivity of PAN, PAN-$Al_2O_3$ polymer electrolytes were showed $1.0{\times}10^{-4}S/cm$, $8.4{\times}10^{-4}S/cm$ at room temperature. When inorganic filler was added in the polymer electrolyte, ionic conductivity and lithium yield more larger than without inorganic filler.

The X-ray spectra dependence for intensifying screens of medical radiography was investigated through analysis of the absorbed coefficiency($\mu$), absorbed efficiency(${\eta}_{\alpha}$) and absorbed ratio(R). It was found that the absorbed coefficiency was increased in the order of $CaWO_4$$CaWO_4$ screen showed the highest value.

Current lead plays the part of connector between ambient temperature and liquid helium superconducting magnet. Having zero resistance characteristic, it is expected that HTS has very low thermal conductivity and generate no joule heat when fabricated to current lead. In particular, among the HTS meterials, HTS tape has high Jc and Ag-sheath of tape plays the part of stabilizer, but it has too poor mechanical strength to be applied and when fabricated as long length tape, it has tendency to decline Jc seriously. In this study, we fabricated Bi-2223 multifilamentary tapes and then made current lead with stacking type using them. Through this work, we conclude that the defect of HTS long length tape is decreased by addition the number of stacking tape and that current lead is able to operate more stably by minimizing the gap of tapes.

$BiNbO_4$ ceramics with 0.06wt% CuO, 0.1wt% $V_{2}O_{5}$ sintered at $900^{\circ}C$. The strip line chip filter has been design and fabricated by screen printing with silver electrode after tape casting. The characteristics of the fabricated filters were compared with the simulated results. In the strip line chip filter, insertion loss value of band pass width was 3.65[dB] and return loss was 8.9[dB] and center frequency was similar that simulation results.

The fiat fluorescent lamp(FFL) can be used to the LCD bat]flighting. In order to evaluate the discharge characteristics of FFL firing voltage, discharge current, luminance and CIE chromaticity with frequency were measured. The experimental results show that firing voltage decreased with increasing the frequency, discharge current increased with increasing the frequency. Luminance of FFL using Xe gas shown $2700\;cd/m^2$ in 700V rms, 80 kHz.

In this study, Brass endcap with 2, 3, 5, and 7mm contact surface and 0.6, 0.9, 1.2, 1.5mm conical cavity depths was fabricated by the punch die while keeping the cavity diameter constant 9.25mm then displacement characteristics of the cymbal actuators with each of brass endcap thickness were measured under an applied voltage $60V_{max}$. Dispacement increased with increasing contact surface and resonant frequency decreased with increasing contact surface, cymbal actuator with 7mm contact surface and 1.5mm endcap cavity depth exhibits $35.89{\mu}m$ displacement and 18.8kHz resonant frequency, displacement increased with increasing endcap cavity depth while contact surface was kept constant at 3mm and Below a endcap thickness of 0.2mm, Differences in displacement between 1.2mm and 1.5mm cavity depth appeared at $0.18{\mu}m$. that is, displacement of cymbal actuator with 1.2mm over cavity depth saturated nearly.

The effect of $Al_{2}O_{3}$ additives on the microstructure, mechanical and electrical properties of ${\beta}$-SiC+39vol.%$ZrB_2$ electroconductive ceramic composites by pressureless sintering were investigated. The ${\beta}$-SiC+39vol.%$ZrB_2$ ceramic composites were pressureless sintered by adding 4, 8, 12wt.% $Al_{2}O_{3}$ powder as a liquid forming additives at $1950^{\circ}C$ for 1h. Phase analysis of composites by XRD revealed mostly of $\alpha$-SiC(6H), $ZrB_2$ and weakly $\alpha$-SiC(4H), $\beta$-SiC(15R) phase. The relative density of composites was lowered by gaseous products of the result of reaction between $\beta$-SiC and $Al_{2}O_{3}$ therefore, porosity was increased with increased $Al_{2}O_{3}$ contents. The fracture toughness of composites was decreased with increased $Al_{2}O_{3}$ contents, and showed the maximum value of $1.4197MPa{\cdot}m^{1/2}$ for composite added with 4wt.% $Al_{2}O_{3}$ additives. The electrical resistivity of ${\beta}$-SiC+39vol.%$ZrB_2$ electroconductive ceramic composite was increased with increased $Al_{2}O_{3}$ contents, and showed positive temperature coefficient resistance (PTCR) in the temperature from $25^{\circ}C$ to $700^{\circ}C$.

SiC thin film have been prepared by ICP-CVD for low temperature deposition and large area deposition. The structural properties of deposited SiC films are characterized by employing SEM, FT-IR, XRD, XPS and Raman Spectroscopy. From the experimetal results, good crystallinity has been achieved in $1000^{\circ}C$ grown SiC film which have carbonization step at $1100^{\circ}C$ for substrate bias of 30V.

The electrical resistivity and mechanical properties of the hot-pressed and annealed ${\beta}$-SiC+39vol.%$ZrB_2$ electroconductive ceramic composites were investigated as a function of the liquid forming additives of $Al_{2}O_{3}+Y_{2}O_{3}$(6:4wt%). In this microstructures. no reactions were observed between $\beta$-SiC and $ZrB_2$, and the relative density is over 97.6% of the theoretical density. Phase analysis of composites by XRD revealed mostly of a $\alpha$-SiC(6H, 4H), $ZrB_2$ and weakly $\beta$-SiC(15R) phase. The fracture toughness decreased with increased $Al_{2}O_{3}+Y_{2}O_{3}$ contents and showed the highest for composite added with 4wt% $Al_{2}O_{3}+Y_{2}O_{3}$ additives. The electrical resistivity increased with increased $Al_{2}O_{3}+Y_{2}O_{3}$ contents because of the increasing tendency of pore formation according to amount of liquid forming additives $Al_{2}O_{3}+Y_{2}O_{3}$. The electrical resistivity of composites is all positive temperature coefficient resistance(PTCR) against temperature up to $700^{\circ}C$.

Hydrogenated amorphous carbon nitride [a-C:H(N)] films were deposited on pretreated silicon(100) substrate in activated gas phase using. RF plasma-assisted CVD. We measured the FT-IR spectrum to investigate $C{\equiv}N$ stretching mode(nitrile), C-H stretching mode, C-H bending mode, C=C stretching mode C=N(imino) mode, and the EDX to investigate the ratio of N to C(0.25). By the results of FT-IR and EDX spectrum, We confirmed that hydrogenated amorphous carbon nitride films successfully were synthesized by RF-PACVD

A Pd-SiC Schottky diode for detection of hydrogen gas operating at high temperature was fabricated. Hydrogen-sensing behaviors of Pd-SiC Schottky diode have been analyzed as a function of hydrogen concentration and temperature by I-V and ${\Delta}I$-t methods under steady-state and transient conditions. The effect of hydrogen adsorption on the barrier height was investigated. Analysis of the steady-state kinetics using I-V method confirmed that the atomistic hydrogen adsorption process is responsible for the barrier height change in the diode.

As-casted high nitrogen alloys (Fe-25%Mn-12%Cr-1%Ni) have been investigated to study core material. Nitrogen concentration in molten alloys was increased with increasing the square root of nitrogen gas pressure in melting chamber. This result can be explained by Sievert's law. Nitrogen that dissolved as a interstital solid solution element in austenite stainless steel increased lattice parameter and hardness. Electric resistivity($\rho$) was increased with increasing nitrogen concentration and was about $80{\mu}{\Omega}cm$ at room temperature. Coefficient of linear thermal expansion of the nitrogen steel was about $22{\times}10^{-6}/^{\circ}C$.

Permeation of $Ca^{2+}$ ions in PVC and flame-retardant polyolefin (FR) compounds for the sheath of medium voltage underground cables was studied. At $70^{\circ}C$ ion permeation increases fast at times of up to a few tens of hour and then at a relatively slow rate. The first fast increase was attributed to the diffusion of ions in the samples while the second slow increase of ion permeation was attributed to the permeation of $Ca^{2+}$ ions through the samples. It was also found that the diffusivity of $Ca^{2+}$ ions in FR compounds is much higher than that in PVC compounds.

Room temperature vulcanizing(RTV)silicone rubber has been widely used to coat porcelain insulators to render water repellency to prevent formation of water filming on the surface and thus to suppress the leakage current and consequent flashover. However, the electrical property and its hydrophobicity of RTV silicone rubber coating under outdoor conditions may be influenced by many environmental factors. In this study various treatments, such as salt-fog, salt water immerging and UV irradiation were applied to samples for investigation the change of the electrical property and hydrophobicity. As a result the leakage current increased and contact angle decreased as the degradation time longer. But the degraded RTV silicone rubber has recovered its hydrophobicity during the drying time in ambient condition because LMW(Low Molecular Weight)silicone fluid diffused from the bulk to the surface.

The extensive use of composite insulators for transmission lines can ultimately be justified only on long-term qualification tests. The actual load working on the insulator in the field is not static load but cyclic load. So in this paper, we discussed an examination of aging degradation by mechanical performance of composite insulators under static tension load and cyclic tension load. and also described useful approaches for analyzing their long term performance so as to develop reliable composite insulators. The static and cyclic tension load-time test data were examined by Weibull distribution for their capability of presuming long term performance. It was found that cyclic tension loads were more severe than static tension loads. The results also indicate that it may be relevant for an user to select composite insulators on basis of their performance under cyclic tension loads than static tension loads.

The needle electrode was inserted in virgin and 1.000 hr aged XLPE which is the insulation used for 22.9 kV underground distribution cable with the distance of 1, 1.5 and 2mm respectively. Breakdown voltage were measured for the virgin and 1.000 hr aged specimen and statistically evaluated through Weibull distribution. As the of electrode increase in virgin and 1.000 hr aged specimen. shape parameter and scale parameter showed increase coincidently. For shape parameter, the value of aged specimen showed the higher than that of virgin specimen.

In this paper, the physical and electrical properties of electrical insulating materials due to linear low density polyethylene (LLDPE)/ethylene vinyl acetate(EVA) blends are studied. The peak of LLDPE/EVA made by blend ratio of 70:30 at $2{\theta}=21.4^{\circ}$ in the results of XRD is higher than the others. In the experiment for electrical conduction properties in order to investigate the electrical properties of specimen, it is confirmed that electrical conduction is increased with the increase of molecular motions with the increase of temperature.

Quartz crystal in contact with viscoelastic medium is described directly in terms of the electrical equivalent circuit of the system. Stearic acid is used as viscoelastic medium and deposited on the surface of quartz crystal using the Langmuir-Blodgett(LB) method. Impedance properties of quartz crystal coated with LB films which were investigated and the possibility of applying the technique to chemical sensing introduced.

We fabricated IMI-O polymer containing imidazole group that can be form a complex structure between the monolayer and the metal ions at the air-water interface. Also, the monolayer behavior at the air-water interface and Langmuir-Blodget films by complexes formation have been investigated by $\pi$-A isotherms, Brewster Angle Microscopy and the scanning Maxwell-stress microscopy.

The electrical characteristics of Stearic acid Langmuir-Blodgett(LB) films were investigated to develop the gas sensor using LB films. The deposition status of LB films were verified I-V characteristic which was increased with an applied voltage for the number of layers and decreased as increasing the distance of electrode. The conductivity of Stearic acid LB films was $10^{-8}[S/cm]$, which is typical of semiconductor. The conductivity of LB films were increased as the temperature was increased. The activation energy was about 1[eV].

By irradiating photoresist on Si or glass with $Ar^+$ (${\lambda}$=514 nm, CW) and Nd:YAG (${\lambda}$=266 and 532nm, pulse) laser beam, the photoresist was etched masklessly in air. Using a fourth harmonic Nd:YAG laser beam, the etching threshold of energy fluence was $25\;J/cm^2$ and the damage of substrate was appeared over $40\;J/cm^2$.

Copper films have been deposited on glass substrate via a thermal decomposition of copper(II) formate using a focused $Ar^+$ laser emitting at 514 nm. The growth kinetics of these Cu films was investigated as a function of laser power and scan speed which varied in the range of 70-150 mW and 0.1-20 mm/s, respectively. The resistivity of the copper films was a factor of about 20 higher than· that of bulk value, but the resistivity decreased due to changes in morphology and porosity of the deposit after annealing at $300^{\circ}C$, 5 min. and was about $10{\mu}{\Omega}cm$.

The optical spectra of microwave plasma by four kinds of gases($N_2$, $N_2-CH_4$, $H_{2}-CH_{4}$ and Air-$CH_4$) have been measured for investigating 388.4[nm] peak which has the same intensity as $H_{\alpha}$(656.4[nm]) peak. A 388.4[nm] peak by $N_2$ plasma, $N_{2}-CH_{4}$ plasma and Air-$CH_4$ plasma may be CN peak because it is with 337.1, 357.8 and 316.0[nm] peaks by $N_2$. And a 388.4[nm] peak by $H_{2}-CH_{4}$ plasma without by $N_2$ 337.1, 357.8 and 316.0[nm] peaks may be CH peak. In the investigation results for optical spectra by $H_{2}-CH_{4}$ plasma and $H_{2}-CH_{4}-O_{2}$ plasma, the density of hydrogen atom was increased because oxygen decompose hydrogen molecules in $H_{2}-CH_{4}$ plasma with oxygen. These hydrogen atom decompose $CH_4$ and increase CH radical. And the crystalline of deposited diamond was good and the growth rate increased.

This paper describes the motion characteristics and micro-discharge of the free conducting particles between plain electrodes under alternating voltage. The particles move between both electrodes due to electrostatic force by applied AC voltage. Various types and sizes of free conducting particles were used to study the motion and micro-discharge characteristics. The micro-discharge and breakdown were observed during the particle motion.

Crosslinked Degree is an important factor to determine dielectric property of crosslinked polyethylene(XLPE) used for the insulation material in power cables. Recently, though it is necessary to investigate electrical properties according to crosslinked degree as a part of the whole characterization of cable. it is not examined closely. In this study, crosslinked degree of samples were measured according to temperature and holding time of crosslinking, electrical tree characteristics of these samples were analyzed by crosslinked degree and applied temperature that was changed from normal temperature to operating temperature of power cables. As a result. when the crosslinked degree was low, dielectric properties were decreased and influence of temperature was increased. but the crosslinked degrees were high. initiation voltages of treeing were increased and dielectric properties were improved. It is proved that the optimum. crosslinked degree was one of most important factor for aging time and residual lifetime of power cable.

PD pulses have about one nanosecond rise time in the $SF_6$ gas insulation. These pulses propagate in the apparatus to PD sensors in the form of the voltage oscillation, high frequency current and the electromagnetic radiation. In this paper, we investigated the characteristics of two types of PD sensors, by putting high frequency signals in the form of sine waves and pulse into the test apparatus in air. Also, we measured PD quantity from the needle electrode and the sensitivity of the sensors. We found that PD of 70pC could be detected with this method and the study in $SF_6$ gas should be carried out for application to $SF_6$ GIS.

This paper describes the effect of impulse current on degradation of ZnO blocks. In this study, an impulse current generator which can produce 8/20 [${\mu}s$], 3 [kA] and 4/10 [${\mu}s$], 5 [kA] waveform is designed and fabricated to simulate the lightning impulse current. The residual voltage, reference voltage, and leakage current flowing to the ZnO blocks are observed. The experimental results show that the leakage current increases continuously with the number of applied impulse current, but no significant changes in residual voltage and in operating voltage are observed until the ZnO block is destroyed. Also, it is confirmed that the main factor on degradation of ZnO blocks is rather the total energy applied to ZnO blocks than the peak value of the impulse current.

In this paper, we purpose automatic diagnosis in online, as the fundamental study to diagnose the partial discharge mechanism and to predict the lifetime, by introduction a neural network. In the proposed method, Ire use acoustic emission sensing system and calculate a fixed quantity statistic operator by pulse number and amplitude. Using statically operators such as the center of gravity(G) and the gradient of the discharge distribute(C), we analyzed the early stage and the middle stage. the fixed quantity statistic operators are learned by a neural network. The diagnosis of insulation degradation and a lifetime prediction by the early stage time are achieved. On the basis of revealed excellent diagnosis ability through the neural network learning for the patterns during degradation, it was proved that the neural network is appropriate for degradation diagnosis and lifetime prediction in partial discharge.

This paper describes the application of two and three dimensional electric field analysis for vacuum interrupter with spiral contacts. The electric potentials of floating arc shield and electric fields in a vacuum interrupter are analysed at various gap distances from 1mm to 12mm. The electric potentials of floating shield is increased with the gap distance, which is because the relative position of shield is closer to the fixed contact so that the capacitance distribution inside interrupter is varied. The calculated results show that the maximum value of electric field in a vacuum interrupter with floating shield is nearly same to that without shield at short gap distance below 5mm, however at longer gaps more intensive electric field is achieved in interrupter with shield comparing with the model without shield, which is due to the influence of charged floating shield.

Degradation diagnosis of XLPE insulated URD cables was accomplished through out new method which was to be analyzed by non-electrical experiments and synthesized by degradation points. To supplement this method, It was also carried out using several electrical analyses PD-q increased generally in proportion to the applied voltage and showed no uniform patterns in relation to the thickness of insulator. Leakage current was unequal according to the thickness of insulator and its range was from 20[nA] to 50[nA]. $Tan{\delta}$ had commonly a different tendency by means of temperature and frequency and also appeared higher at the outer part rather than inner part of insulator. Breakdown voltages were measured and breakdown lifetimes were predicted appling for Weibull distribution function. As a result, breakdown lifetime in failure cables was longer up to three times as much as general cables.

In Color AC Plasma Display Panel(PDP). Low luminous efficiency is a major problem. We measured luminous efficiency of PDP as a function of the Ar mixing ratio. Our results show that efficiency has improved by $5{\sim}10%$ at the condition of 0.5% Ar mixing ratio, compared with Ne-Xe(4%) or He-Ne-Xe(4%) (He:Ne = 7:3) gas.

In this paper, an optical fiber sensor(OF sensor) utilizing the principal of Mach-Zehnder interferometer were proposed to detect the partial discharge signals in insulating oil. At first the AC breakdown signals were detected to check the response of the OF sensor. The detected signals from OF sensor was consistent with that from current probe. After the response checking, simultaneous measurements and continuous recording were made of electrical and the OF sensor signals from partial discharge(PD) produced by IEC(b) electrode system immersed in insulating oil. The continuous recording made it possible to extract basic quantities of PD from the OF sensor signals, such as pulse phase and pulse amplitude distribution. Through the signal analysis, the absolute peaks of the OF sensor PD signal was found to be increased with the amplitude of electrical signals, and these results mean that there is a strong correlation between OF sensor and electrical PD signals. It was demonstrated that the OF sensor in this research had a possibility to detect the PD signals in power apparatus.

In this paper, the electron transport characteristics in $SiH_4$ has been analysed over the E/N range $0.5{\sim}300[Td]$ and Pressure value 0.5, 1, 2.5 [Torr] by a two-term approximation Boltzmann equation method and by a Monte Carlo simulation. The motion has been calculated to give swarm parameters for the electron drift velocity. diffusion coefficient, electron ionization, mean energy and the electron energy distribution function. The electron energy distribution function has been analysed in $SiH_4$ at E/N=30, 50[Td] for a case of the equilibrium region in the mean electron energy and respective set of electron collision cross sections. The results of Boltzmann equation and Monte carlo simulation have been compared with experimental data by Pollock, Ohmori, cottrell and Walker.

The tracking characteristics of silicon rubber degraded by accelerated outdoor exposure employing a weather-o-meter have been investigated. The tracking test was performed according to IEC Publ.587 but the concentration of conductive material was two times higher than the IEC standard in order to accelerate the tracking failure. The number of large effective scintillation and the current of high voltage circuit were measured by changing two signals as voltage signals. It was fiund that the increase of exposure time resulted in the reduction of tracking resistivity except the fact that the specimens slightly degraded within 200 hours has slightly increased the duration time.

In an electric substation, there are many sources of surge such as switching operations or lightning strokes. A grounding system submitted to such surge current presents very different behaviour from the observed under low frequency current. Especially, it has been reported that significant overvoltage occurs at the current feed-in point, and this may cause damages to other grounded components in the substation area. This paper describes the basic mechanism of improvement of grouding performance in transient state with auxiliary grounding grids.

The stringing load was added to tower design that consider the active load in 765kV transmission line construction. The nominal auxiliary members of steell tubular tower arm were altered into stress members by means of three dimensional design analysis method. 765kV transmission line construction also use self-standing tower that does not install temporary wire which support the section tower placed between drum field and engine field when stringing process.

In order to improve insulating character and ability of insulating system of power apparatus, the interfacial and complex structure is widely used. However, the interface or complex structure of insulation materials is reported as a weak point which causes breakdown. As the interface of insulation system degrades its electrical property and eventually causes a failure, the datailed phenomenon analysis is reported. The object of this paper is to evaluate dielectric property of PET film with the interface. The $tan{\delta}$ increased with the existence of semiconducting layer and showed prominent decrease as a function of temperature. Also, the $tan{\delta}$ showed prominent increase as a function of frequency. The dielectric properties of interfacial were affected by the interface characteristics.

Exploitation of equipment with cross linked polyethylene (XLPE) insulation requires its condition monitoring and diagnostic. Traditionally diagnostics of insulation is carried out by means of partial discharge detection. Many researchers have developed a lot of methods to identify the defect by the PD form. However, such identification of a defect, for example, void, inclusion or treeing, does not say about its danger from a point of view of full insulation gap breakdown and insulation construction failure. The information about the form and size of formed upon high voltage treeing is necessary for prediction of the remained resource of XLPE insulation. For this purpose we carry out experimental research for determination of the dependencies between PD characteristics in XLPE upon time and three dimension PD patterns of corresponding treeing. The investigations were carried out by means of electrical measurement of PD current and simultaneous optical recording of treeing image. Test results show that the PD patterns can be applied for detecting tree growth well.

We evaluated cell survivability by changing RLC value on HV impulse network. When the L value is changed from 0 to 10mH in this circuit. we found that cell survivability is shown large decline with 4mH of L value. I respect to this result, when waveshapes of oscillatory decay are presented along the variation of L value in RLC circuit, we analyzed whether discharge waveform properties have an effect on sterilization ratio, and measured threshold voltage as the minimum peak voltage of a single pulse which can sterilize cells. Finally, we found that the sterilization effect was related to number of threshold voltage waveforms being applied.

In this paper, the NO was oxidized $NO_2$ by using the non-thermal plasma and NOx removal characteristics were measured by showering NaOH water-solution to $NO_2$. The NO oxidation increased in the order of DC, AC, and Pulse. NOx oxidation for two stage with applied voltage was better than that for one stage with applied voltage. NO oxidation didn't depend on applied voltage. While NO oxidation was going on, NOx removal efficiency was 20-25%, however, significantly depended on the injection method of air and $H_2O$ + air. When NaOH water-solution density of 20% was showered to flue gases, NOx removal efficiency increased to 64%.

DC Arc Plasma was applied in order to convert of hydrocabon fuels (Methane) to hydrogen, which has higher available energy. Plasma can generate very high temperatures with a high degree of control, using electricity. Plasma can be used to produce the pure hydrogen fuel, and has rapid response time. In addition, the use of plasma could provide for a greater variety of operating modes including the posibility of virtual elimination of $CO_2$ production by pyrolytic operation and could obtain byproduct (Carbonblack).

In this paper, a double cylindrical type ozonizer has been designed and manufactured to improve ozone yield by cooling external electrode. The ozonizer equipped with three electrodes( central, internal and external electrodes ) and two gaps. Discharge and ozone characteristics are described in this paper by varying flux( Q ) of oxygen supplied gas, temperature of cooling gas and supplied voltage.

In this study, a relationship between partial discharge and the radiated electromagnetic waves is investigated by measuring electromagnetic waves using a biconical antenna and a spectrum analyzer. The patterns of frequency spectrum of radiated electromagnetic waves measured at the atmospheric pressure in Liquid Nitrogen($LN_2$) during the partial discharges in nonuniform electric field depend on positive DC power. From these points of view. it is considered that these results obtained from this investigation may be used as fundamental data for diagnosis and prediction of insulation on the equipments of superconducting and cryogenic applications.

In this paper, we present design rule of high-voltage rectangular generator working in wide band frequency domain. Though power electronics now have voltage ratings up to several kV, it is difficult to design and fabricate high-voltage systems with the power electronic devices alone. So we have combined IGBT with technically designed transformer to get the high-voltage rectangular waveforms. In this work, next two things are the main factors. The first one is design of transformer working low-frequency domain of less than 10Hz. And the second one is adding offset voltage part. As a result, we can get variable frequency high-voltage rectangular waveform and this can be used as a voltage source of sandpaper manufacturing process.

The circuit breakers had been withdrawn from 345 kV SIC substation. because these were made following the old IEC requirement(IEC 56; TRV rating) and insufficient current rating(2,000 A) for the system requirement(4,000 A). And, they are going to be reused at 345 kV UR substation and SJS switching section. This paper deals with the TRV(temporary recovery voltage) analysis results in order to reuse them. The analysis results are satisfied with the IEC requirements of RRRV(Rate of Rise of Recovery Voltage) and peak voltage($U_c$) from 2000 to 2010.

Fast burning achieves higher efficiency, and reduces cycle variations which is able to improve vehicle driveability. Furthermore, the greater resistance to knock with fast burning can allow the fuel economy advantages associated with higher compression ratio to be realized. One way of increasing the combustion speed is to enhance the performance of ignition systems which were able to reduce the early period of combustion. It is well known that shortening the initial stage of combustion also reduces the cyclic variations. This literature survey deals with the papers which have studied the ignition process or various ignition systems. Those systems increasing the combustion speed, extending the lean misfire limit, reducing the exhaust gas and stabilizing the operating condition of the spark ignition engine by modifying the ignition process or increasing ignition energy.

In practice, there may be various defects in an insulating system, so that the PD signals can be produces from these defect simultaneously. Regarding these situations, we have to discriminate the type of defect as well as to determine whether the PD occurs or not. In our research. some analysis results of the PD signals from multi-defects insulating system will be presented. We measure the PD signals using three kind of electrode system: IEC(b). Needle-Plane and mixed electrodes. To simulate multi-defect systems, we combine two electrode systems and apply test voltage simultaneously. Neural network, statistical analysis methods will be tested, and the possibilities and limitations of each method will be clarified.

Many researchers make efforts to develop an effective material with anti-degradation property. Specially, the porcelain type insulator is required exchanging to polymer insulator according to the environmental consideration. In this paper, we have developed the estimation system using the PD & SD testing. Those approach has been very successful applied to the various practical insulator.

In this paper, we designed basic concept and structure of bypassing device which promoted the activity of low voltage line-fuse, when it perceived the too small short-fault current to activate line-fuse which located at the between secondary of pole transformer and home immediately. And we study displacement of bypass contact and electromagnetic force caused by the short-fault current by the basic experiment to understand the basic characteristic of bypassing movements.

In this paper, we present theoretical designs for a beam steering phased array antenna that uses a true time delay optical feeder. A variable true time delay is achieved by employing one tunable laser source and high dispersion fibers with different length. The wavelength tunable optical carrier propagation in a high-dipersion fiber realizes a true time delay, with the steering direction set by a single voltage controlling the wavelength. Beamsteering of a phased array antenna is obtained by controlling the tunable laser source. An employment of a high dispersion fiber response shows wide-band operation of beem steering antenna system.

The volume holographic memory system suffers from the crosstalk noise. We study use of error correction coding(ECC) and angular multiplexing for digital holographic memory(DHM) system. The analog image is encoded to binary images by ECC. Binary images are stored using angular multiplexing in DHM. The retrieved binary images are decoded by ECC. The bit error-rate is measured for perspective of the DHM system.

We demonstrate and characterize a volume holographic filter operating at $1.55{\mu}m$ region, which corresponds to the wavelength region of optical communication system. By changing recording times or the angle between writing beams. the reflectivity, the filtered wavelength, and the bandwidth of this filter can be controlled. A center wavelength of 1532.8 nm, reflectivity of 10.7% and a bandwidth with full width at half-maximum of 4.0nm are measured in our experiment.

Resonance radiation trapping has a great influence on the characteristics of gas discharge. We calculate the spatial and spectral distribution of photons by Monte Carlo method in AC PDP cell.

We fabricated fiber gratings with three different Ge-doped fibers exposed to 60atm pressure of Hz gas at 90"C for different times and studied the effects of Ge-doping concentration and $H_2$ loading time on the growth of gratings. According to experiments. the growing effect of hydrogen loading on high Ge-doped fiber was great.

We have proposed and demonstrated a novel method of heterodyne detection using all-fiber Mach-Zehnder interferometer. The method is characterized by the phase modulation with a sawtooth waveform instead of a frequency modulation in true heterodyne. The experimental results will be compared with the expected results.

In this paper, $Ar^+$ ion laser etching process of single/poly crystalline silicon with $CCl_{2}F_{2}$ gas is studied for MEMS applications. To investigate the effects of process parameters, laser power, gas pressure, scanning speed were varied and multiple scanning was carried out to obtain high aspect ratio. In addition, scanning width was varied to observe the trench profile etched in repeating scanning cycle. From the etching of $2.6{\mu}m$ thick polycrystalline Si deposited on insulator, trench with flat bottom and vertical side wall was obtained and it is possible to apply this results for MEMS applications.

Mo-tip FED of 1 inch diagonal was vacuum sealed using sodalime-to-sodalime glass electrostatic bonding under $10^{-7}torr$. The bonding properties of the bonded sodalime-to sodalime structure were investigated and emission characteristic of packaged FED panel was measured.

In this paper, the effects of the drive-in process parameters on the residual stress profile of the p+ silicon film has been investigated. All the residual stress profile has been estimated by the second-order polynomial. All the coefficients of the polynomial have been determined from the measurement of the deflections of cantilevers and a rotating beam by using a surface profiler meter and by means of focusing a calibrated microscope. As the drive-in temperature or the drive-in time increases, the boron concentration decreases and the magnitude of the average residual stress decreases. If the boron concentration decreases the tensile residual stress decreases except near the surface where the magnitude of compressive residual stress increases.

In micromechanical system (MEMS) such as microactuators. thin film has been widely used as structural material. MEMS materials have difference with bulk in terms of mechanical properties. So, we design the advanced test structure for micromechanical properties of MEMS. The designed structure includes the newly developed pre-crack and it is driven by electrostatic force. To measure the fracture toughness, the pre-crack formation in the test structure is developed with conventional etching process. The advanced test structure is fabricated by application of semiconductor technology. After this, we propose analytical methodology to evaluate the fracture toughness and fatigue properties through a prediction of crack behavior from the variations of stiffness and frequency. Additionally, life time of a mirror plane used in DVD(Digital Video Disk) is measured as a function of capacitance and applied voltage under the accelerated conditions. Ultimately, we propose the method to evaluate the micromechanical reliabilities of the MEMS materials using the advanced test structure.

A capacitance-type humidity sensor using porous silicon layer is developed. The unique property of this sensor is a structure which has electrodes on the surface of the wafer like a general IC device. To do this. the sensor was fabricated using process such as localized formation of porous silicon, oxidation of porous silicon layer, and etching of oxidized porous silicon layer. The measurement of humidity-sensing ability was done for two type of sensors using porous silicon layer formed in 25 and 35% HF solutions, respectively. As the result, the former sensors showed larger value and variation of capacitance for the relative humidity.

In this paper, the fabrication of a micropump with two giant magnetostrictive films of Sm-Fe and Tb-Fe is presented. The pump consist of one silicon wafer and one cover glass. The micropump consists of an actuator diaphragm, a paired nozzle and diffuser, and two through holes. The Structure of the micropump is fabricated by the chemical vapor deposition, the etching and the sputtering of the magnetostrictive films. The deflection of the actuator measured diaphragm is measured by using the laser vibrometer and the flow rate of the micro pump is observed by using a video microscope.

Silicon membrane to be used for micropump is fabricated and the deflection of the membrane driven by the electromagnetic force is measured. Silicon and glass are anodic bonded and Si is thinned. Silicon membrane is fabricated by the glass etching. The gold pattern can be protected against HF by the washing and fixing process under the glass etching process. The electromagnetic force is gained by the magnetic field driven by the current flowing through two coils. Deflection of the silicon membrane has a tendency of increasing with the increase of the driving current.

This paper presents the fabrication of a micro pump consisting of a pair of Al f1ap wave and a phase change actuator. The phase change actuator is composed of a heater, a silicone rubber diaphragm and a working liquid chamber. The diaphragm is actuated by the evaporation and the condensation of the working liquid. The actuator pumps fluid through the valves. The micro pump is fabricated by the anisotropic etch, the boron deposition and the metal evaporation. The forward and the backward flow characteristics of the f1ap valves were obtained. Also, the flow rate of the micro pump has been measured. When the square wave input of 12 V, 60% duty ratio and 0.2 Hz is applied, the average flow rate is $0.15{\mu}{\ell}/sec$ for zero pressure difference.

This paper presents the scheme of bus and line transfer for improving transient stability and the reactive transient stability index usable in time simulation. And also multi-transferring scheme for improving damping is proposed. These results can be applied in determining the effective position for transfer control.

In this research project, two aspects of small signal stability are studied: improvement in Hessenberg method to compute the dominant electromechanical oscillation modes and siting FACTS devices to damp the low frequency oscillation. Fourier transform of transient stability simulation results identifies the frequencies of the dominant oscillation modes accurately. Inverse transformation of the state matrix with complex shift equal to the angular speed determined by Fourier transform enhances the ability of Hessenberg method to compute the dominant modes with good selectivity and small size of Hessenberg matrix. Any specified convergence tolerance is achieved using the iterative scheme of Hessenberg method. Siting FACTS devices such as SVC, STACOM, TCSC, TCPR and UPFC has been studied using the eigen-sensitivity theory of augmented matrix. Application results of the improved Hessenberg method and eigen-sensitivity to New England 10-machine 39-bus and KEPCO systems are presented.

In this research a fault-tolerant and bumpless switching control is proposed for boiler systems used in the power plants. Firstly, three operating points are selected to control the nonlinear boiler through the full operational range, and the $H_{\infty}$ loop shaping controller and the model-based predictive controller(MBPC) are designed. To prevent the windup and bump problems which are caused by the actuator saturation and the controller switching, an anti-windup and bumpless transfer technique is adopted to the $H_{\infty}$ loop shaping controller. Also the constrained gain-scheduling technique is applied to MBPC to achieve the same objective. Secondly, the fault-tolerant control technique is proposed to continue the control action without stopping the boiler operation even in case of some faults. Through various simulation studies, the performances of the proposed control techniques are demonstrated.

This paper presents the control design of a three-module boost converter with a two-stage output filter. An advanced three-loop control scheme is employed to the control design in order to obtain good dynamic performance of the converter at the presence of the secondary filter stage. The paper presents the control design, dynamic analysis and performance improvement with the three-loop control.

PLT(28) ($Pb_{0.72}La_{0.28}Ti_{0.93}O_3$) dielectric thin films have been deposited on Pt/Ti/$SiO_2$/Si substrates in situ by a laser ablation. We have systematically changed the laser fluence from $0.5\;J/cm^2$ to $3\;J/cm^2$, and deposition temperature from $450^{\circ}C$ to $700^{\circ}C$. The surface morphology was changed from planar grain structure to columnar structure as the nucleation energy was increased. The PLT thin film with columnar structure showed good dielectric properties. It is shown that the deposition temperature strongly affect the film nucleation compared with the laser fluence.

To be applied to electrical equipment HTSC tapes have to endure external stress and so on. The critical current density has been shown depending on the mechanical properties. strain and bending stress. AC loss reduction is primary concern in the development of such high-efficiency equipment. AC losses in Bi-2223 silver-sheathed tapes, both single and multi-filamentary, were investigated by means of AC magnetization techniques. The results were compared with the hysteresis loss equation based on Bean model and the eddy current loss equation. The AC loss of the mono-filamentary tape was the hysteresis. On the contrary, the AC loss of the multi-filamentary tape was substantially dominated by the eddy current loss in the Ag matrix.

Previous counter-current flow limitation (CCFL) and critical heat flux (CHF) studies included investigations on the inlet entrance, inclined channel and gap effects for the most part. In this study, the local CHF correlation was presented to be used in the numerical analysis for the 3 dimensional hemispherical geometry. Also, first-principle analyses were performed to determine the maximum heat removal capability from the debris through the gap that may be formed during a core melt accident. The maximum heat removal capability by gap cooling can be applied in quantitatively assessing the severe accident management measures.

To examine the influence of unsteady wake on the flow and heat transfer characteristics, an experiment has been conducted in a four-vane linear cascade. Flow and heat transfer measurements are made for the inlet Reynolds number of 66000(based on chord length and free-stream velocity). Turbulent intensity and stress were measured using hot wire anemometer, and to measure the convective heat transfer coefficients on the blade surfaces liquid crystal/gold film Intrex technique was used. The disturbance by the unsteady wake is characterized by the unresolved unsteadiness. The unsteady wake enhances the turbulent motion of flow in the cascade passage. It also promotes the boundary layer development and transition. The results show that heat transfer coefficients on the suction surface increase with increasing unresolved unsteadiness.

On the study, The activated carbon assemblies(ACA) were prepared by activation of the coated glass mate(woven type) with phenolic resin at $700^{\circ}C$ under $N_2$ after drying and curing processes. Surface of the ACA was continuously modified with $N_2$, $CO_2$ or $NH_3$ at $700^{\circ}C$ for 2 hour for comparison of adsorptive characteristics between the ACA and commercial activated carbon cloth. The ACA showed high surface areas up to $2440\;m^2/g$ when converted into the coated carbon base, and the surface was investigated by FT-IR and XPS. The basic ACA modified with $NH_3$ displayed the efficient removal capability of $SO_2$, which is 75% of that in commercial activated carbon cloth. Therefore, it has proved the applicability of ACA as an inexpensive materials for Dry de-SOX system.