• 약학회지
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• 제44권3호
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• pp.251-256
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• 2000

Sterically stabilized liposomes (SSL) composed of distearoylphosphatidylcholine, cholesterol, dicetylphosphate and distearoylphosphatiodylethanolamine-N-poly(ethyleneglycol) 2000 (DSPE-PEG 2000) were made by reverse phase evaporation method to prolong biological half-life and decrease toxic side effect of drug. Streptozocin (572), a water-soluble antitumor agent with short half-life, was selected as a model drug. The size of SSL was controlled by polycarbonate extrusion to 100 nm which is adequate size for long circulation in plasma. The release rate of drugs from SSL in PBS was evaluated. And the stability of STZ-containing liposomes against drug leakage into rat plasma was evaluated in order to investigate the interaction of liposome and plasma protein. Incorporation of DSPE-PEG 2000 into conventional liposomes significantly decreased the drug leakage into rat plasma.

• 비파괴검사학회지
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• 제25권3호
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• pp.157-162
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• 2005

In order to evaluate the corrosion of reinforcing steel-bars (rebar) in concrete, a nondestructive evaluation by the half-cell potential method is currently applied. In this study, potentials measured on a concrete surface are compensated into those on the concrete-rebar interface by the inverse boundary element method (IBEM). Because these potentials are obtained three-dimensionally (3-D), 3-D visualization is desirable. To this end, a visualization system has been developed by using VRML (Virtual Reality Modeling Language). As an application, results of a reinforced concrete (RC) slab with corroded rebars are visualized and discussed.

• 대한토목학회논문집
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• 제11권3호
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• pp.47-58
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• 1991

본 논문에서는 무한요소를 이용한 지반-구조물 상호작용 해석에 대하여 연구하였다. 적층지반(Layered Soil)과 같이 여러 가지 응력파가 동시에 전파되는 탄성지반의 외부영역을 효과적으로 모형화할 수 있는 동적무한요소를 개발하였으며, 요소행렬 구성시 수반되는 무한대 방향으로의 적분을 효과적으로 수행하기 위하여 Gauss-Laguerre 적분방법을 기초로 하여 새로이 고안된 적분방법을 제시하였다. 이 방법의 타당성은 반무한 탄성지반과 적층된 반무한 탄성지반 위에 놓여 있는 원형강판의 임피던스(Impedance) 함수를 구하여 해석적으로 구한 값들과 비교함으로써 검토하였다.

• Geomechanics and Engineering
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• 제23권4호
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• pp.393-403
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• 2020

We design the Green-Naghdi model type III (GN-III) with widespread thermoelasticity for a thermoelectric half space using a memory-dependent derivative rule (MDD). Laplace transformations and state-space techniques are used in order to find the general solution for any set of limit conditions. A basic question of heat shock charging half space and a traction-free surface was added to the formulation in the present situation of a traveling heat source with consistent heating speed and ramp-type heating. The Laplace reverse transformations are numerically recorded. There are called the impacts of several calculations of the figure of the value, heat source spead, MDD parameters, magnetic number and the parameters of the ramping period.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1995년도 학술대회
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• pp.63-67
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• 1995

This paper proposes a new frequency offset correction technique for OFDM receivers on a frequency-selective fading channel. The frequency offset in the OFDM signals is known to introduce an interchannel interference among the multiple subcarriers, which degrades the receiver performance severely. In order to reduce the frequency offset, this paper describes an algorithm with two stages: acquisition and tracking. At both stages the algorithm oversamples the received OFDM signals. At the acquisition stage the frequency offset is reduced to half or less than the intercarrier spacing by matching the sign patterns of even and odd samples. Next, at tracking stage the frequency offset is compensated by a frequency detector which is controlled by the correlation of the even and odd sample sets. From the results, it is found that the proposed algorithm can correct the frequency offset even if the initial offset exceeds one half of th eintercairrers spacing.

• Transactions on Electrical and Electronic Materials
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• 제11권4호
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• pp.178-181
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• 2010

An automotive IC voltage regulator which consists of one-chip based on a metal-oxide semiconductor field effect transistor (MOSFET) is investigated experimentally with three types of packaging. The closed type is filled with thermal silicone gel and covered with a plastic lid on the MOSFET. The half-closed type is covered with a plastic case but without thermal silicone gel on the MOSFET. Opened type is no lid without thermal silicone gel. In order to simulate the high temperature condition in engine bay, the operating circuit of the MOSFET is constructed and the surrounding temperature is maintained at $100^{\circ}C$. In the overshoot the maximum was mainly found at the half-closed packaging and the magnitude is dependent on the packaging type and the surrounding temperature. Also the impressed current decreased exponentially during the MOSFET operation.

• 한국정밀공학회지
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• 제25권7호
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• pp.64-71
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• 2008

Burr generated on plate holder should be removed through additional process, because it has an influence on the function of automotive seat recliner. The process layout to perform simultaneously embossing and half blanking of plate holder has been developed in this study in order to minimize the influence of burr formation. The optimal process condition to satisfy the required dimensional accuracy of plate holder has been determined using Taguchi method and finite element analysis. It has been shown from experimental results that the proposed method is decidedly superior to the previous FCF method from the aspect of sheared surface, roll-over, flatness and burr height.

• 영어어문교육
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• 제11권2호
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• pp.51-66
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• 2005

This study investigates the feasibility of incorporating student evaluations of peer review interactions into the course grade for an EFL writing course. The use of such evaluations offers a way to grade the process of writing more directly than using writing portfolios alone. Moreover, evaluating peer review interactions highlights the social aspect of writing, which is valuable in the current post-process climate in writing instruction. The 18 members of a semester-long EFL writing course at a Korean university were trained in peer response for one half of a semester; then performed evaluations of peer review interactions during the second half of the semester as part of their writing course. Student evaluations were examined to reveal whether any bias occurred due to relative age, gender, major, or question type. The results revealed no such biases. Therefore, it is suggested that students are capable of providing fair evaluations of peers, which means the evaluations can be factored into the course grade in order to evaluate the social aspect of the writing process.

• Journal of Magnetics
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• 제4권4호
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• pp.107-110
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• 1999

In order to investigate the magnetism of Ru submonolayer on Pb(001), we have performed first-principles calculations for half-layer of Ru on Pd(001) using the full-potential linearzed augmented plane wave (FLAPW) method. We have found that the magnetic moment of Ru for 0.5 layer is 2.21 B. It is found that substrate Pd layers are polarized by the 0.5 Ru overlayer to have significant magnetic moments. Our results are compared with those obtained by the anomalous Hall effect. The calculated electronic structures, i,e., the spin densities and density of states are presented and discussed in relation with magnetic properties.

• 한국철도학회논문집
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• 제7권3호
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• pp.173-179
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• 2004

This paper describes a low-cost single-phase active power filter, which consists of a half-bridge PWM inverter with a simple control circuit. In order to verify the performance of proposed active power filter, many computer simulations with EMTP codes and experimental works with a hardware prototype were done. Both results confirm that the proposed active power filter shows excellent performance to eliminate the harmonics generated in the single-phase non-linear load. The active power filter has advantage of low implementation cost and compact size, using a half-bridge inverter and a simple control circuit with only one current sensor. So, it can be fabricated as a plug-in type. This paper shows the necessity and a good possibility to apply such advantage to the electric railway system.