• Proceedings of the Materials Research Society of Korea Conference
• /
• 2007.11a
• /
• pp.125.2-125.2
• /
• 2007

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11b
• /
• pp.410-413
• /
• 2001

In this paper, we present results of this that design of the multi-layer VCO(Voltage Controlled Oscillator), which is composed of the resonation circuit and the oscillation circuit, using EM simulator and nonlinear RF circuit simulator. EM simulator is used for acquiring EM(Electromagnetic) characteristics of conductor pattern as well as designing multi-layer VCO, Acquired EM characteristics of the circuit pattern was used like real components at nonlinear RF circuit simulator. Finally VCO is simulated at nonlinear RF circuit simulator. The material for the circuit pattern was Ag and the dielectric was DuPont #9599, which is applied for L TCC process. The structure is constructed with 4 conducting layer. Simulated results showed that the output level was about 1[dBm], the phase noise was 102 [dBc/Hz] at 30[kHz] offset frequency, the harmonics -8dBc, and the control voltage sensitivity of 30[MHz/V] with a DC current consumption of l0[mA]

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2008.10a
• /
• pp.401-404
• /
• 2008

In the present investigation, a high precision thermal imprint system for micro ceramic products was developed and the net-shape manufacturing of multi-layer ceramic reflector for LED (Light Emitting Diode) was conducted with a precision metal die. Workpiece used in the present investigation were the multi-layer laminated ceramic sheets with pre-punched holes. The cavity with arbitrary angle was formed on the circular and rectangular holes of the ceramic sheets. During the imprinting process, the ambient temperature of the imprint system was kept over the transition temperature of the ceramic sheet and then rapidly cooled. The results in this paper show that the present method can be successfully applied to the fabrication of very small size hole array for ceramic reflector in a one step operation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07b
• /
• pp.653-656
• /
• 2002

In this paper, we present the simulation results of multi-layer VCO(voltage controlled oscillator), which is composed of resonator, oscillator, and buffer circuit, using EM simulator and nonlinear RF circuit simulator. EM simulator is used for obtaining the EM(Electromagnetic) characteristics of conductor pattern as well as designing the multi-layer VCO. Obtained EM characteristics were used as real components in nonlinear RF circuit simulation. Finally the overall VCO was simulated by the nonlinear RF circuit simulator. The material for the circuit pattern was Ag and the dielectric was DuPont 951AT, which will be applied for LTCC process. The structure of multi-layer VCO is constructed with 4 conducting layer. Simulated results showed that the output level was about 4.5 [dBm], the phase noise was -104 [dBc/Hz] at 30 [kHz] offset frequency, the harmonics -8 dBc, and the control voltage sensitivity of 30 [MHz/V] with a DC current consumption of 9.5 [mA]. The size of VCO is $6{\times}9{\times}2$ mm(0.11[cc]).

• Corrosion Science and Technology
• /
• v.15 no.3
• /
• pp.129-134
• /
• 2016

The effects of Ti on the high temperature oxidation of Ni-based superalloys were investigated by cyclic oxidation at $850^{\circ}C$ and $1000^{\circ}C$. The oxide scale formed at $850^{\circ}C$ consists of $Cr_2O_3$, $Al_2O_3$, and $NiCr_2O_4$ layers, while a continuous $Al_2O_3$ layer was formed at $1000^{\circ}C$. The oxidation rate of the alloy with higher Ti content was higher than the alloy with less Ti content at $850^{\circ}C$, possibly due to the increase in the metal vacancy concentration in the $Cr_2O_3$ layer involved by incorporation of $Ti^{4+}$. However, Ti improved the oxidation resistance of the superalloy at $1000^{\circ}C$ by reducing oxygen vacancy concentration in $Al_2O_3$ layer.

• The Journal of the Convergence on Culture Technology
• /
• v.5 no.1
• /
• pp.341-346
• /
• 2019

The study aims to provide a study on the mixing ratios and manufacturing methods of biodegradable PLA sheets for mid - term introduction, A 3-layer process was introduced to produce a multifunctional multi-layer structure sheet having improved heat resistance, impact resistance and transparency while having anti-fogging functionality as a biodegradable PLA sheet used for the purpose of anti-fogging function. Inner layer, core layer and outer layer were mixed and extruded. The inner layer and core layer were studied for a biodegradable PLA multi-layer sheet structure having inner hardness and high heat resistance and outer layer for imparting antifogging function. By applying the results of this study, plastic PLA properties and heat-resistant temperature can be improved to replace and expand plastics.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2011.04a
• /
• pp.53-56
• /
• 2011

본 논문에서는 지진시 구조물의 진동을 줄이기 위한 방법으로 모드에너지 기반 신경망 제어 방법을 제안하였다. 모드에너지 기반 신경망 제어 방법은 신경망의 학습 과정에서 구조물의 모드 에너지를 이용하여 목적함수를 구성하며, 이 목적함수를 최소로 하는 학습을 진행한다. 제안된 제어 알고리즘의 적용성을 검증하기 위해서 능동질량감쇠기(AMD, Active Mass Damper)가 설치된 3층 구조물을 예제 모델로 선택하였으며, El Centrol지진을 이용하여 모드에너지기반 신경망제어 알고리즘을 학습시켰다. 모드에너지 기반 신경망 제어 알고리즘의 제어 성능은 학습 후 임의의 지진에 대한 하중으로 California지진을 사용하여 검증하였다. 해석 결과에서 California지진에 대한 제어 전 후의 결과와 기존의 방법인 MLP(Muli-layer Perceptron)의 결과와 비교하였다. 또한 제안된 제어 방법을 적용할 때, 지진시 구조물의 비선형 거동은 제어후 거의 보이지 않는 것을 확인 할 수 있었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.04b
• /
• pp.77-80
• /
• 2004

In this study, the purpose is to verified the feasibility to develope Hybrid x-ray detector in order to resolve problems of direct and indirect x-ray detectors. The properties of X-ray detector depend on absorption of X-ray, charge generation by x-ray photon, leakage current. In this study, CdS was used as photoconductor, and $Y_2O_2S:Tb$ as x-ray phosphor was formed on CdS in order to embody Hybrid structure. And Screen printing was used to form Muli-layer. Characteristics of this specimen were analyzed by using SEM, and XRD. And Photoluminescence spectrum of $Y_2O_2S:Tb$, leakage current, with respect to applied voltages, output charge with respect to applied voltages, and X-ray sensitivity were measured. Also, linearity with respect to dose was measured. Leakage current was similar with direct digital x-ray detector, but sensitivity of the hybrid structure is much better than the single-layer structure.