• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.195-196
• /
• 2005

In recent years, as the needs of MOS's a high quality is desired to get the superior electrical characteristics and reliability on MOSFET. As an alternative gate dielectric have drawn considerable alternation due to their superior performance and reliability properties over MOSFET, 2'nd silicidation formation process has been proposed as a dielectric growth/annealing process. In this study the author observed process characteristics on MOS structure. In view points of the process characteristics of MOS capacitor, the oxygen & polysilicon was analyzed by SIMS analysis on l'st & 2'nd Ti process, the oxygen and Si2 contents[Count/sec] of 1.5e3 & 3.75e4 on l'st process and l.1e3 & 2.94e4 on 2'nd process, the Ti contents' of 8.2e18 & 6.5e18 on 1'st and 2'nd process. The sheet resistance[$\Omega/sq.$] was 4.5 & 4.0, the film stress[dyne/cm 2] of 1.09e10 & 1.075e10 on l'st and 2'nd process. I could achieved the superior MOS characteristics by 2'nd silicidation process.

• The korean journal of orthodontics
• /
• v.14 no.2
• /
• pp.249-261
• /
• 1984

This study was to investigate the fitness of the dental arch line to the parabola, and to estimate correlation between the parabola and some ratios of the dental arch measurements. The sample was consisted of the 64 plaster casts showing normal occlusion which was taken from males and females of Korea, aging from 15 to 18 years. The photos of occlusal surface of the plaster casts were taken, and 38 landmarks on the film were selected. The 3 dental arch lines on each dental arch were imaged. One is the dental arch line passing the points of the most buccal surfaces of the teeth, another is that passing the buccal cusp tips of the posterior teeth and the incisal edges, and the other is that passing the midpoints of the teeth. The landmarks on the film were digitized, and measurements and statistics were performed by the IBM computer. The results were as follows; 1. The fitness of the dental arch to the parabola was very good. The fitness of thor upper dental arch was above $91\%$, and that of the lower dental arch was $93\%$. 2. The dental arch line passing the points of the most buccal surfaces of teeth was best fit to the parabola, the buccal cusp tip arch line and the midpoint arch line in order. 3. Correlation between the ratio of oblique molar dental height to molar width and the parabola was very high. 4. The ratio of oblique molar dental height to molar width was devided into 4 groups by the quartiles, and mean parabolic equations and curves were calculated and drawn.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.21 no.3
• /
• pp.277-287
• /
• 2003

As primary source data toward the systematic and efficient management of national land, the aerial photographs have been utilized in many different areas. However, the quality of aerial photographs does not meet the requirement of the users due to unidentified miscellaneous reasons. Aiming for the improvement of the quality of aerial photographs, we first investigated the current status of domestic rules and working procedures related to aerial photographing and film processing in great details. In addition, we investigated and analyzed those of advanced nations such as U.S.A., Canada, G.B. and so on. It was drawn from the comparison and analysis that the poor quality of domestic aerial photographs resulted from lack of the quantitative and objective standards on aerial photography specification as well as poor condition and aging problem of equipments such as aerial camera and film developing equipment. In this paper, we proposed a stepwise strategic plan which consists of the aerial photography specification and quantitative quality control standard taking into consideration the current status of domestic rules and working procedures.

• Journal of Powder Materials
• /
• v.30 no.6
• /
• pp.521-527
• /
• 2023

Piezoelectric technology, which converts mechanical energy into electrical energy, has recently attracted drawn considerable attention in the industry. Among the many kinds of piezoelectric materials, BaTiO₃ nanotube arrays, which have outstanding uniformity and anisotropic orientation compared to nanowire-based arrays, can be fabricated using a simple synthesis process. In this study, we developed a flexible piezoelectric energy harvester (f-PEH) based on a composite film with PVDF-coated BaTiO₃ nanotube arrays through sequential anodization and hydrothermal synthesis processes. The f-PEH fabricated using the piezoelectric composite film exhibited excellent piezoelectric performance and high flexibility compared to the previously reported BaTiO₃ nanotube array-based energy harvester. These results demonstrate the possibility for widely application with high performance by our advanced f-PEH technique based on BaTiO₃ nanotube arrays.

• Imaging Science in Dentistry
• /
• v.37 no.4
• /
• pp.211-215
• /
• 2007

Purpose: The purpose of this study was to evaluate the effect of the kV on fractal dimension of trabecular bone in digital radiographs. Materials and Methods: 16 bone cores were obtained from patients who had taken partial resection of tibia due to accidents. Each bone core along with an aluminum step wedge was radiographed with an occlusal film at 0.08 sec and with the constant film-focus distance (32 cm). All radiographs were acquired at 60, 75, and 90 kV. A rectangular ROI was drawn at medial part, distal part, and the bone defect area of each bone core image according to each kV. The directional fractal dimension was measured using Fourier Transform spectrum, and the anisotropy was obtained using directional fractal dimension. The values were compared by the repeated measures ANOVA. Results : The fractal dimensions increased along with kV increase (p < 0.05). The anisotropy measurements did not show statistically significant difference according to kV change. The fractal dimensions of the bone defect areas of the bone cores have low values contrast to the non-defect areas of the bone cores. The anisotropy measurements of the bone defect areas were lower than those of the non-defect areas of the bone cores, but not statistically significant. Conclusion: Fractal analysis can notice a difference of a change of voltage of x-ray tube and bone defect or not. And anisotropy of a trabecular bone is coherent even with change of the voltage of x-ray tube or defecting off a part of bone.

• Restorative Dentistry and Endodontics
• /
• v.22 no.1
• /
• pp.156-169
• /
• 1997

This study was designed to evaluate the influences of evaporation of liquid of dental cements by drying during long term using. Zinc phosphate cement, polycarboxylate cement, and glass ionomer cement were used, and evaluated the properties as follows; consistency, setting time, film thickness, solubility, and compressive strength according to the ADA specification. The specimens of control group were made by mixing the newly opened liquid using the powder-liquid ratio recommended by the manufacturer, and the specimens of ES groups were made by mixing the 10% evaporated liquid by drying with the powder-liquid ratio recommeded by the manufacturer, and the specimens of EM group were made by mixing the 10% evaporated liquid with the powder-liquid ratio modified for standard consistency. The following conclusions were drawn ; 1. The viscosity of mixture of all kinds of cements were increased by the evaporation of liquid, especially the viscosity of glass ionomer cement were influenced significantly. 2. The amount of liquid should be increased to get a standard consistency at the using of evaporated liquid of cement, the most significant increase of liquid amount was required on Ketac-Cem. 3. The setting times were increased at both cases of mixing of evaporated liquid with powder - liquid ratio recommended by manufacturer or modifided through consistency test. 4. At an experimental group of mixing of the evaporated liquid with powder-liquid ratio recommended by manufacturer, solubility was decreased and film thickness was increased. 5. By the result of evaporation of cement liquid, the compressive strength of polycarboxylate cement was increased slightly and it of glass ionomer cement was increased, however, by the increase of amount of liquid to be possible to manipulate the compressive strength were decreased.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.17 no.12
• /
• pp.1353-1361
• /
• 1992

Holographic optical element(HOE) is fabricated with the properties of lightweight, thin thickness and interconnectivity for free space. Particularly, HOE for optical interconnection and multiple image processing should have a high efficiency and equal spot intensity, Nonlinear equations for 2-dimensional binary phase grating(BPG) structure is solved by computer simulation based on modified Newton method. Computer-generated pattern drawn by plotter is scaled down and translated into the microfilm. After contact printing between the microfilm and silver halide hologram film, phase diffraction grating produces the $5{\times}5$ multiple spots. Experimental results are shown that bleached phase grating has a high efficiency and equal focused beams except central zero order.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.433-433
• /
• 2013

Graphene, $sp^2$-hybridized 2-Dimension carbon material, has drawn enormous attention due to its desirable performance of excellent properties. Graphene can be applied for many electronic devices such as field-effect transistors (FETs), touch screen, solar cells. Furthermore, indium tin oxide (ITO) is commercially used and sets the standard for transparent electrode. However, ITO has certain limitations, such as increasing cost due to indium scarcity, instability in acid and basic environments, high surface roughness and brittle. Due to those reasons, graphene will be a perfect substitute as a transparent electrode. We report the graphene synthesized by inductive coupled plasma enhanced chemical vapor deposition (ICP-PECVD) process on Cu substrate. The growth was carried out using low temperature at $400^{\circ}C$ rather than typical chemical vapor deposition (CVD) process at $1,000^{\circ}C$ The low-temperature process has advantage of low cost and also low melting point materials will be available to synthesize graphene as substrate, but the drawback is low quality. To improve the quality, the factor affect the quality of graphene was be investigated by changing the plasma power, the flow rate of precursors, the scenario of precursors. Then, graphene film's quality was investigated with Raman spectroscopy and sheet resistance and optical emission spectroscopy.

• Journal of Korea Multimedia Society
• /
• v.25 no.10
• /
• pp.1475-1482
• /
• 2022

Mickey Mousing perfect match between animation sound and image was an aesthetic in the field of animation, but since the 2000s, works such as and released by producers such as DreamWorks and Pixar have expanded the perfection of synchronization to irony. It also influenced the identification system of sentiment. It is time to view the directing attempt of these elements as a factor that changed the new paradigm of narrative, and related research is needed. In this study, the scene of was analyzed as a case study for the synchronization of animation sound and image components and the boundary direction on the recognition of identification between reality and fiction. Aesthetic recognition of the research work is based on the premise of real time and space perception, and the audience can recognize in the conceptual world as an integrated art by playfully producing fictional time and space. The direct antithesis of synchronization and identification was drawn to maintain the curiosity of the next scene by repeating selective concealment and disclosure of information in the direction of conveying an unfamiliar and heterogeneous feeling to the audience.

• Journal of the Korean Society of Industry Convergence
• /
• v.24 no.4_2
• /
• pp.509-515
• /
• 2021

In this study, a pressure vessel for a heat pipe was fabricated by bonding a metal thin film using a polymer compound sheet. In order to confirm the applicability of the experimentally manufactured copper material thin heat pipe of 0.6 mm or less, the pressure resistance and effective thermal conductivity for pressure generated according to the type of the working fluid of the heat pipe were evaluated to suggest the commercialization potential of the thin heat pipe. As a result of evaluating the pressure resistance and effective thermal conductivity performance of the thin heat pipe, the following conclusions were drawn. 1) Using a PEEK-based polymer compound sheet, it was possible to fabricate a pressure vessel for a thin heat pipe with a pressure resistance of up to 1.0 MPa by bonding a copper thin film, and the possibility of commercialization was confirmed at a temperature below 120 ℃. 2) In the case of the effective thermal conductivity performance evaluation test, the effective thermal conductivity of ethanol was higher than that of FC72 and Novec7000, and in the case of ethanol, the maximum effective thermal conductivity was 2,851 W/mK at 3.0 W of heating.