• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 추계학술대회 논문집
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• pp.150-156
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• 2000

The purpose of this paper is to evaluate the noise level and the noise source for domestic trains. We measured and analyzed the interior noise, the rolling noise and the engine noise at Honam line(Seodaejeon-Jangseong) for passenger and power cars. The noise level is below 69㏈A for Seamaeul PMC(Powered Motor Car) coachs, below 65㏈A for Seamaeul and Mukungwha coachs, over 80㏈A for the driver's room of PMC and diesel-electric locomotives.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2000년도 종합학술발표회 논문집 Vol.10 No.1
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• pp.216-219
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• 2000

A Ka Band 3-stage MMIC (Monolithic Microwave Integrated Circuits) LNA(Low Noise Amplifiers) has been designed. The MMIC LNA consists of two single-ended type amplication stapes and one balanced type amplication stage to satisfy noise figure characteristics and high gain and amplitude linearity. The 0.15um pHEMT has been used to provide a ultra low noise figure and high gain amplification. Series and Shunt feedback circuits were inserted to ensure high stability over frequency range of DC to 80 GHz. The size of designed MMIC LNA is 3100mm ${\times}$ 2400um(7.44$\textrm{mm}^2$). The on wafer measured noise figure of the MMIC LNA is less than 2.0 dB over frequency range of 22 GHz to 30 GHz.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.538-543
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• 2000

The purpose of this study is to develope electrostatic separation system for recycling of mixed waste plastics. The electrostatic separation system is designed and investigated the separation efficiency for separating of mixed waste plastics. Electrostatic separation system consisted of a tribocharger, separator (two electrode), collector (5 tray) and controller (positive/negative high voltage power supply). The tribocharger is a fluidized bed using tribo-electrification mechanism between particles and particles. In experimental results, the tribocharger of the fluidized bed was more effective separation efficiency. It showed the purity of $85{\sim}99\;%$ and the recovery of $80{\sim}98\;%$ from the powder of mixed plastics such as LDPE, HDPE, PP, PS, PET and PVC. Especially, In the separation experiment of Polyvinylchloride(PVC) which generates hazardous hydrogen chloride gas in case of the combustion. its purity was over 99 % and recovery was over 95 %.

• Computational Structural Engineering : An International Journal
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• 제1권1호
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• pp.71-80
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• 2001

A reliability approach to evaluate structural performance has gained increased acceptability and usage over the past two decades. Most reliability analyses are based on the reliability of an individual component without examining the entire structural system. These analyses often result in either unnecessary repairs or unsafe structures. This study uses examples of series, parallel, and series-parallel models of structural systems to illustrate how the component reliabilities affect the reliability of the entire system. The component-system reliability interaction can be used to develop optimum lifetime inspection and repair strategies for structural systems. These examples demonstrate that such strategies must be based on the reliability of the entire structural system. They also demonstrate that the location of an individual component in the system has a profound effect on the acceptable reliability of that component. Furthermore, when a structure is deteriorating over time, the reliability importance of various components is a1so changing with time. For this reason, the most critical component in the early life of the structure may not tie the most critical later.

• 한국수산과학회지
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• 제41권1호
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• pp.48-53
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• 2008

Twelve black seabreams (Acanthopagrus schlegeli) were tagged with acoustic transmitters and their movement and behavior patterns were tracked using acoustic telemetry from 12 December 2006 to 15 August 2007. Seven of the 12 fish stayed within 500 m of the release point for over a month. In the spring tide, the number of detected signals and swimming depth of tagged fish changed at 12-hour intervals with the ebb tide. The number of detected signals of tagged fish decreased dramatically with the passage of time and had decreased by over 80% in May 2007, compared with January 2007.

• 한국실내디자인학회논문집
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• 제15권2호
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• pp.91-98
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• 2006

The aged population increasing rapidly, the population rate of over 65 years old was over 7.5% in 2000 in Korea and it means that Korea is aging society. Increasing participation of woman in public affairs, becoming a nuclear family and increasing old aged people who want to stand alone brought about more the old households. But the aged welfare accommodation are still insufficient and more facilities accommodating the aged should be built. 80.5% of people according to poll by the Ministry of Health and Welfare responded the support of the aged is a serious problem in Korea. This result indicates the reality that the system for the aged are unsatisfied. Although these situations made a new concept of 'silver-town' of the welfare facility for the aged, it is under a transition in the aspect of the social system and the architectural aspect as well. This study will select good examples among facilities in the metropolitan area, analysis space and propose resonable program.

• Bulletin of the Korean Chemical Society
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• 제25권6호
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• pp.843-846
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• 2004

Pt nanoparticles loaded on alumina through an impregnation at room temperature was prepared using $K_2PtCl_4$ and acrylic acid as capping material. Transmission electron microscopy showed that the deposited Pt particles indicate ca. 80% cubic shapes with a narrow distribution of 8-10 nm in size. Propylene hydrogenation over the catalyst has been carried out to evaluate their catalytic performance by the values of activation energy. It is determined from the initial rate, reaction order, and rate constant and is found to be $9.7{\pm}0.5$ kcal/mol. This value has been discussed by comparing to those of encapsulated- and truncated octahedral Pt nanoparticles deposited on alumina, respectively, to study influence of the particle size and shape, and capping material used on the activation energy.

• 한국기계가공학회지
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• 제10권6호
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• pp.56-62
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• 2011

In this study, a method for the press forming of rectangular aluminium tube has been proposed. Rectangular aluminium tube has high stiff as the cold steel which can be lighter over 30% weight. It is increased every year by being recycled over 80%. Press die consists of punch, wing-die and holder for aluminium tube bending. When punch is applied with aluminium tube, holder is operated as same punch and wing-die is rotated through hinge. Stress-strain relations and springback are considered by bending angle of aluminium tube. In this study, the behaviors on tubes of square aluminium and rectangular aluminium with different thickness and area are established by the analysis of $DEFORM^{TM}$-3D program. Reducing fuel consumption is expected by using the aluminium tube deformation and it becomes the lightweight through recycling.

• Transactions on Electrical and Electronic Materials
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• 제7권5호
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• pp.271-275
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• 2006

Al oped zinc oxide (AZO) films were prepared by Facing Targets Sputtering (FTS) system for TCO applications. The electrical, optical and structural properties of AZO thin films have been investigated with input current, oxygen gas flow ratio and substrate temperature. Deposition was carried out at room temperature and $200^{\circ}C$. Working gas pressures were fixed at 1mTorr. As a result, AZO thin film deposited with an optical transmittance over 80 % and a resistivity about $10^{-4}{Omega}{\cdot}cm$.

• 한국농림기상학회:학술대회논문집
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• 한국농림기상학회 2001년도 춘계 학술발표논문집
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• pp.77-80
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• 2001

In many temperate forest ecosystems, large quantities of pine pollen are deposited over a short period in early summer (Doskey and Ugoagwu 1989). Because pollen grains decompose rapidly and have macronutrient concentrations, the pollen rain may be an important component of nutrient dynamics in natural terrestrial and aquatic ecosystems (Stark 1972).(omitted)