• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.80-82
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• 2009

The dependence of the efficiency characteristics of hydrogenated amorphous silicon single junction solar cells on the various intrinsic layer thickness has been investigate in the glass/$SnO_2$:F/p,i,n a-Si:H/Al type of amorphous silicon solar cells by cluster PECVD system. The open circuit voltage, short circuit current, fill factor and conversion efficiency have been measured under AM 1.5 condition. The result of the cell performance was improved about 8.2% due to an increase in the short circuit current.

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1980-1990
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• 2017

A study on the multi-objective optimization of Interior Permanent-Magnet Synchronous Motors (IPMSMs) with 2, 3, 4 and 5 flux barriers per magnetic pole, based on Genetic Algorithm (GA) is presented by considering the aspect of irreversible demagnetization. Applying the 2004 Toyota Prius single-layer IPMSM as the reference machine, the asymmetrical two-, three-, four- and five-layer rotor models with the same amount of Permanent-Magnets (PMs) is presented to improve the torque characteristics, i.e., reducing the torque pulsation and increasing the average torque. A reduction of the torque pulsations is achieved by adopting different and asymmetrical flux barrier geometries in each magnetic pole of the rotor topology. The demagnetization performance in the PMs is considered as well as the motor performance; and analyzed by using finite element method (FEM) for verification of the optimal solutions.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2002.05a
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• pp.36-36
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• 2002

Effects of pulse-plating on the wear and corrosion resistance of chrome-carbon layers were studied. The plating were carried out at $06A/\textrm{cm}^2$ in modified Sargent bath containing formic acid at $53^{\circ}C$. The chrome layer were super-saturated with carbon up to 2.0wt. %, which precipitated as chrome carbide such as $Cr_{23}C_6$ after vacuum aging above $200^{\circ}C$ for 1 hour. This resulted in improvement of hardness and wear resistance of the chrome layer. Considering the reduction of corrosion resistance due to the thermal effect, optimum vacuum aging condition of the chrome layer in this study was I-hour at $200^{\circ}C$.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.05a
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• pp.9.2-9.2
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• 2011

Ultrathin polyelectrolyte (PE) multilayer films prepared by the versatile layer-by layer (LbL) assembly method have been utilized for the preparation of light-emitting diodes, electrochromic, membrane, and drug delivery system, as well as for selective area patterning and particle surface modification because the various materials with specific properties can be inserted into the film with nano-level thickness irrespective of the size or the shape of substrate. Since the introduction of the LbL technique in 1991 by Decher and Hong, various hydrophilic materials can be inserted within LbL films through complementary interactions (i.e., electrostatic, hydrogen-bonding or covalent interaction). In this study, it is demonstrated that LbL SA multilayer films based on nucleophilic substitution reaction can allow the preparation of the highly efficient magnetic and/or optical films and nonvolatile memory devices.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.465-468
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• 1998

For porous silicon layer to be used as active layer in various devices, it is necessary to be formed locally along with a designed pattern on the wafer. However, there is still no suitable masking layer to withstand against the high concentration of HF for a time of some minutes up to some hours during the anodic process effectively. In this work, we investigated the property of selectivity between p$^{+}$ and n layers to form localized porous silicon even without a mask by the difference of the anodic I-V characteristics on the doping level and doping type. The width of the pattern made in the sample was 2mm, and the formed porous silicon layer was observed by SEM to see the morphology on the cross section below the surface. As the results, it was found that the selectivity was reasonable for the pattern size over 100.mu.m.m.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.113-116
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• 2008

The active layer thickness and curing condition dependent performance of an organic thin film transistor (OTFT) with inkjetted organic semiconductor (OSC) layer is studied The best performance of the OTFT was found when the thickness of ose was ~120 nm cured at $60^{\circ}C$. The performance enhancement of the OTFT with inkjetted OSC layer was discussed by comparing the OTFT with spin-coated ose layer.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1429-1431
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• 2006

We developed new anti-glare(AG) layer which has improved image quality and solved mechanical problems. Conventional silica-type AG has some restrictions related to sparkling, causing mechanical defects. The new anti-glare layer is designed with adjusted optical factors and polymer type. Therefore new anti-glare layer meets two main characteristics at once using unmatched optical property between scattering in material and surrounding.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.194-197
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• 2002

Applying dual layer insulator on plastic substrates improved electrical characteristics of organic thin film transistor(TFT). A high-quality silicon dioxide(SiO$_2$) suitable for a insulator was deposited on plastic substrates by e-beam evaporation at 110$^{\circ}C$. The insulator film which was treated by N$_2$ annealing at 150$^{\circ}C$ showed excellent I-V, C-V characteristics. The dual layer insulator structure of polyimide-SiO$_2$ improved the roughness of SiO$_2$ surface and showed very low leakage current. In addition, the flat band voltage has been reduced from -2.5V to about 0.5V.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.10
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• pp.147-155
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• 2002

In the stereolithography process, the accuracy of product depends on laser power, scan speed, scan width, scan pattern, layer thickness, resin characteristics and so on. Therefore, appropriate process parameters are required for an accurate prototype. This paper presents a method to determine the key process parameters, i.e., laser scan speed, hatching space, and layer thickness based on scan length, scan area, and layer slope. In order to determine these parameters, three neural networks are employed to represent operator’s experience and knowledge. Optimum values on scan speed, hatching space and layer thickness are recommended to improve the surface roughness and build time on the developed SLA machine.

• Geomechanics and Engineering
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• v.16 no.3
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• pp.233-245
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• 2018

Interest to basal reinforced piled embankments is increasing recently due to their rapid construction and reliability. A comprehensive parametric study is conducted to determine effects of pile properties, reinforcement stiffness, embankment properties and soft soil properties into settlements, pressures and excess pore water pressure development and dissipations. Results which are obtained by using one-layer reinforcement during construction are compared with the results obtained by using two-layer reinforcement during construction. Finite element method is used during the parametric study. Second layer of reinforcement is placed in five different positions in order to reveal effects of reinforcement position into behaviour. Traffic load is also taken into consideration during the study. Differences between the results without presence of traffic loading and with presence of traffic loading is stated in this the study.