• Journal of Power System Engineering
• /
• v.10 no.2
• /
• pp.16-21
• /
• 2006

On this study, numerical analysis was performed for the 3 dimensional flow field of gas and particle phase for axial inlet cyclone, a part of dust collector. We applied FVM to visualize the gas phase. The flow was solved using ${\kappa}-{\varepsilon}$ turbulence model. The major parameters considered in this study were helical guide vane, inner diameter, length. Particle trajectory calculations were performed for the particle sizes of $5{\mu}m{\sim}75{\mu}m$. The distribution curve of particle sizes was made of Rosin-Rammler function. The simulation results show various gas flows, particle trajectories on numerical models.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.11a
• /
• pp.264-269
• /
• 2001

Axial fans are widely used in household electrical appliances due to their easy usage and high flow rate for cooling capacity. At the same time, the noise generated by these fans causes one of serious problems. In order to calculate the noise of a fan, we develop the software IFD - Intranet Fans Design. With this software we can design, analysis the performance and predict the noise of fan. The prediction model, which allowed the calculation of acoustic pressure at the blade passing frequency and it's higher harmonic frequencies, has been developed by Lowson's equation. To calculate the unsteady resultant force of the blade, time-marching free-wake method is used. The objective of this study is to calculate the effects of number of blades, rotating velocity, and sweep angle on the noise of fan..

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.84-90
• /
• 2000

Integrated tools are developed for the analysis of the aerodynamic performance and aeroacoustics of helicopter rotors. Heli-NK(Helicopter Navier-Stokes & Kirchhoff) code is for hovering and heli-PA(Helicopter Panel & Acoustic analogy) for forward flight. The former showed its ability to predict the hovering efficiency and high-speed impulsive noise level. Thrust calculation, noise levels, and noise directivity patterns are investigated to confirm the availability of the latter. With some proper validation and improvements. these codes will be more useful and practical.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2012.04a
• /
• pp.274-278
• /
• 2012

Vertical pumps are structurally weak in terms of vibration because of installed heavy motor on top of the pumps in form of cantilever. So high vibration on top of the pumps can occur with low vibration in the bottom. These vibration problems experienced very frequently. Majority of studies have been related to the unbalance of rotating parts or structural resonance. In this paper, we introduce an unusual case, vibration variation caused by VPF(Vane Passing Frequency) according to water level.

• The Research Journal of the Costume Culture
• /
• v.11 no.4
• /
• pp.551-561
• /
• 2003

The regulations for costume were set to improve people's moral fiber and cultural standards. In the 17th and 18th century, the main aim of this regulation was to prohibit luxury. But being the turning point to a modem state, with breaking social status and development of commerce, industry, and the mind of imitation, regulation for luxury wasn't enforced, but rather it brought many revolutionary changes in costume. Restraining human impulse to express beauty was no longer subject to regulation. Therefore, people started to recognize the human figure with shorter Jegory(저고리) and strengthened ceremonial capacity by broadening po's(포) sleeves. The silk fabrics were the most popular fabric during this era, special patterns were added for decoration and also for blessings. Complementary colors were used for contrast on the collar (깃), cuffs (끝동), Gyotrnagi (곁마기), and sash (고름). This color composition gave a younger and more active look. And with red stripes on the sleeves, it emphasized the beauty of the color arrangements as well as providing protection from the devil.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2001.05a
• /
• pp.139-143
• /
• 2001

무선 ATM망에서는 무신 접속으로 인하여 단말의 이동성이 발생하는데, 단말기는 이동 중에도 호의 끊김 없이 QoS를 보장하면서 연속적인 서비스를 제공받을 수 있어야 한다. 사용자 및 이동성의 증가와 작아지는 셀 크기로 인하여 핸드오버는 빈번해 질 것이다. 무선 ATM망에서 핸드오버 발생시 멀티미디어 서비스를 제공하기 위해서는 한정된 무선 대역폭을 인접 셀에 해당대역폭을 예약하는 것이 주류를 이루었다. 그러나 이동 단말기의 이동 방향을 알지 못함으로써 불특정 다수의 셀에 대역폭을 예약하는 깃이 문제점으로 지적되었다. 그래서 이동 단말기의 이동 방향을 추정하여 추정된 셀에만 대역폭을 예약하는 방법을 제안하게 되었다. 본 논문에서는 Fuzzy 이론을 이용하여 이동 방향을 추징하여 추정된 셀에만 대역폭을 예약하는 방법을 사용하여 시뮬레이션을 통해 이전의 알고리즘과 QoS 성능을 분석하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2001.05a
• /
• pp.209-213
• /
• 2001

In this paper, we analyzed the radio interference between Bluetooth and Wireless LAN/video transmitter in the 2.4GHz band with Monte-Carlo Method. The simulation results show that it is necessary to limit under 10mW of the Bluetooth power to avoid the harmful interference between Bluetooth and Wireless LAN/video transmitter.

• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.385-389
• /
• 2003

Three-dimensional experimental analysis was conducted in the pulverizer simplified isothermal model. The experiment model was constructed on a 1/3.5 scale of 500MW pulverizer. The purpose of this study is to investigate the effect of design parameters on the pulverized coal separator efficiency. Where used pulverized coal separator design parameters are guide vane angle, static classifier angle, dynamic classifier rpm. Taguchi method was used to find the effective design parameters related to pulverized coal separator efficiency. The results of the experiment showed that guide vane angle and dynamic classifier rpm were the design key parameters. In addition to the total number of experiment cases were reduced by Taguchi method.

• Proceedings of the Korean Information Science Society Conference
• /
• 2006.06a
• /
• pp.313-315
• /
• 2006

Robot Software Communication Architecture는 URC 로봇을 위해서 제안된 표준 시스템 소프트웨어 구조이다. RSCA용 응용 프로그램은 다수의 컴포넌트의 결합으로 구성되는데 RSCA의 기반이 된 SCA에서는 컴포넌트를 프로세스고 실행할 것인지 쓰레드로 실행할 것인지에 대해서 명확하게 정의하고 있지 않다. 만약 각각의 컴포넌트의 특성을 고려하여 어떻게 실행할 깃인지에 대한 부가적인 정보를 기술하고 이 정보에 따라서 컴포넌트를 실행하게 된다면, 보다 효율적으로 응용 프로그램을 실행할 수 있게 된다. 본 논문에서는 RSCA를 확장하여 컴포넌트의 실행에 대한 정보를 기술하는 방법 및 기술된 정보에 따라서 컴포넌트를 실행하기 위한 방법을 제시한다.

• 유체기계공업학회:학술대회논문집
• /
• 2005.12a
• /
• pp.373-377
• /
• 2005

The Performance of in-line duct fan depends on the design parameters of impeller and guide vane. such as sweep back angle of impeller, the number of blades, outlet blade angle, guide vane angle etc. In this experimental study total four kinds of impellers having different sweep back angles, $90^{\circ},\;72.5^{\circ},\;55^{\circ},\;37.5^{\circ}$ with 8 guide vanes, different the number of blades, 6ea, 8ea, 10ea, 12ea, different kinds of outlet blade angles, $30^{\circ},\;45^{\circ}.\;60^{\circ}$ and different kinds of guide vane angles, $15^{\circ},\;30^{\circ},\;45^{\circ}$ were selected and their performance measured to investigate the effects of them. The results were non-dimensionalized to compare their performance.