• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.7 no.2
• /
• pp.276-283
• /
• 1997

A dry impregnation method was used for preparing pellet type Pt/$SnO_2$ gas sensor. The crystal structure, direction of the crystal, crystal size and microstructure between the catalyst and the support ($SnO_2$) were characterized with electron diffraction analysis, transmission electron microscopy, scanning electron microscopy. The characterization indicates that when Pt/$SnO_2$ sample is calcined at $400^{\circ}C$, the Cl content associated with the Pt phase diminishes and the part of Pt is moved into $SnO_2$ support. This results in the enhancement of gas sensitivity. After the reactor with a Pt/$SnO_2$ sample was run with a flow rate of 30 sccm (a mixture of 0.5% $H_2$ in $_N2$) for a while, the resistance of $SnO_2$ was saturated, but the $SnO_2$ kept absorbing $H_2$ gas. This indicates that the surface state was saturated. For the 14 ppm $H_2$ gas, the sensitivity of Pt/$SnO_2$ devices was about 81% at an operating temperature of $300^{\circ}C$.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.12
• /
• pp.3771-3776
• /
• 2010

The dynamics of the $CN^-$-ligated ferric cytochrome c (CytcCN) in $D_2O$ at 283 K following Q-band photoexcitation at 575 nm was observed using femtosecond time-resolved vibrational spectroscopy. The equilibrium vibrational spectrum of the CN stretching mode of CytcCN shows two overlapping bands: one main band (82%) at $2122\;cm^{-1}$ with $23\;cm^{-1}$ full width at half maximum (fwhm) and the other band (18%) at $2116\;cm^{-1}$ with $7\;cm^{-1}$ fwhm. The time-resolved spectra show bleaching of the CN fundamental mode of CytcCN and two absorption features at lower energies. The bleach signal and both absorption features are all formed within the time resolution of the experiment (< 200 fs) and decay with a life time of 1.9 ps. One transient absorption feature, appearing immediately red to the bleach signal, results from the thermal excitation of low-frequency modes of the heme that anharmonically couple to the CN fundamental mode, thereby shifting the CN mode to lower energies. The shift of the CN mode decays with a lifetime of 2 ps, equivalent to the time scale for vibrational cooling of the low-frequency heme modes. The other transient absorption feature, which is 3.3 times weaker than the bleach signal and shifted $27\;cm^{-1}$ toward lower energies, is attributed to the CN mode in an electronically excited state where the CN bond is weakened with a lowered extinction coefficient. These observations suggest that photoexcited CytcCN mainly undergoes ultrafast radiationless relaxation, causing photo-deligation of $CN^-$ from CytcCN highly inefficient. As also observed in $CN^-$-ligated myoglobin, inefficient ligand photodissociation might be a general property of $CN^-$-ligated ferric hemes.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.05a
• /
• pp.283-286
• /
• 2005

This study measures the levels of various receiving points for reducing deviations the floor impact sound. According to the results, 63-125Hz band appeals the large deviations. Among the spacial points, the spot of 0.75m from the wall correspond with the average of all spots. The KS stipulates that the receiving point should be off the wall more than 0.5m But obeying the rules, the large deviation appears. So, this study shows that the adequate receiving point is 0.75m from the wall.

• Proceedings of the KIEE Conference
• /
• 2001.05a
• /
• pp.283-286
• /
• 2001

본 논문은 전력 품질개선장치인 DVR(Dynamic Voltage Restorer)시스템의 제어알고리즘 개발에 관한 것이다. DVR은 배전전계통에 직렬변압기를 통해 설치되어 전원의 순간전압강하(Voltage sag)를 보상하는 장치이며 전력변환장치 직렬변압기 에너지저장장치, 충전장치, 보호장치등으로 구성된다. 지락사고, 비선형부하의 순간투입, 뇌서지등 여러 요인에 의해 3상전원에서 발생하는 다양한 형태의 전압sag 보상이 가능한 제어알고리즘 모델을 제시하고 컴퓨터시뮬레이션을 통해 기본성능을 확인한 후 소형 DVR을 제작해 시험하였으며 이시험결과를 실 용량 DVR시제품의 설계에 이용하였다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2004.10a
• /
• pp.280-283
• /
• 2004

Micro-lens patterned micro-mold fabrication method for Light Guiding Plate(LGP), kernel part of LCD-BLU(Back Light Unit), was presented. Instead of erosion dot pattern for LGP optical design, micro-lens pattern, fabricated by LIGA-reflow process, was applied. Optical pattern design method was also developed not only for negative pattern LGP, but also positive pattern LGP. During injection molding process, experimental study was conducted to improve replication quality and brightness of ${\sim}50um$ micro-lens pattern mold. The effect of mold temperature for the replication quality of micro-lens array was studied.

• Journal of Microbiology
• /
• v.33 no.4
• /
• pp.283-288
• /
• 1995

We have identified hemolysin rendering virulency of Vibrio anguilarum grown at 23.deg.C which was evaluated on human RBCs. Hemolysin itself was separated as a single band on non-denaturing gel electrophoresis. Vibrio hemolysin was destroyed by trypsin and proteinase K and was heat labile. Optimal pH for activity was around pH 6 while pI of the molecule was recognized as 5.7, with relative distance (R$\sub$f/) on non-denaturing gel was 0.7. Addition of EDTA and FeCI$\sub$3/ drew the possibility that the production of hemolysin was mainly induced to overcome iron deficiency inside host animalsd infection.

• Proceedings of the KIEE Conference
• /
• 1987.07a
• /
• pp.279-283
• /
• 1987

In this paper an intelligent supervisory programmable controller for automatic assembly machine is developed. This is achieved by adding sequence control hardware with input-interrupts to supervisory real time language and also by incorporating an automatic planning method which uses a predicate logic model and an action model. The designed intelligent supervisory programmable controller is applied to Die Bonding Machine and is to found to work well.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.270-271
• /
• 2007

In this study, piezoelectric properties of PZW-PMN-PZT multilayer actuator sintered at $900^{\circ}C$ low temperature have been investigated. The multilayer actuator was fabricated by tape casting methods. The density above $8[g/cm^3]$ was obtained at all the specimens. Also, according to increasing the number of multilayer, effective electromechanical coupling factor$(k_{eff})$ showed increasing trend. The $k_{eff}$ of multilayer actuator showed the maximum value of 0.283 at 11 layer. However, according to increasing the number of multilayer, mechanical quality factor(Qm') showed decreasing tend. The Qm' of multilayer actuator showed the maximum value of 920 at 5 layer.

• 대한예방의학회:학술대회논문집
• /
• 1998.10b
• /
• pp.283-284
• /
• 1998

• Proceedings of the Korea Information Processing Society Conference
• /
• 2012.11a
• /
• pp.282-283
• /
• 2012

가상메모리 시스템에서 페이지 부재(page fault)를 최소화하기 위해서는 미래에 사용될 페이지를 미리 예측하는 것이 중요하다. 미래에 사용될 페이지는 이미 입력된 페이지들의 패턴 분석을 통해 예측 가능하며 이를 통해 시스템 성능을 최대화 할 수 있는 페이지 교체 정책(page replacement policy)에 대한 연구가 필요하다. 본 논문에서는 동일한 교체 우선권을 가지는 페이지들 간의 예측 적중률을 높이기 위하여 기존의 NUR(not used recently) 정책에 참조횟수 비트를 추가하여 우선 순위를 판단하는 방법을 제안한다. 제안하는 정책은 C 언어를 기반으로 모델링 되었으며 시뮬레이션 결과 페이지 프레임의 크기와 무관하게 기존의 정책들에 비해 성능이 향상됨을 확인하였다.