• Venture DIGEST
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• s.108
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• pp.20-24
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• 2007

우리나라 정치와 금융의 중심인 여의도. 여의도에는 기업인들이라면 염원하는 기업 상장을 주재하는 기관. 한국증권업협회가 위치해있다. 특히 증권업협회 13층에는 비상장기업 중 성장단계에 있는 벤처기업 등 혁신형 중소기업들이 증권시장을 통하여 자금조달 및 회수가 가능하도록 개설된 프리보드가 있다. 기존의 <제3시장>이란 이름에서 2005년 7월 <프리보드>로 변신 후 이번 7월 13일 두 돌을 맞는 중소벤처 대상 증권시장 프리보드. 이번 여름 프리보드 입성을 준비하는 쏜다넷 송승한 대표와 함께 한국증권업협회의 프리보드 본부를 찾아가 중소벤처 경영에 유용한 방향키를 클릭홰 보자.

• Venture DIGEST
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• s.116
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• pp.44-45
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• 2008

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.105-110
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• 2019

Effect of height on the size and shape of carbon nanotube (CNT) aggregates in the freeboard region of a bubbling fluidized bed ($0.15m\;i.d.{\times}2.6m\;high$) has been determined. Feret diameter and Heywood diameter of the CNT aggregates in the freeboard region of fluidized bed increased with increasing gas velocity. The average aggregate diameters and CNT particle number in the aggregates decreased with increasing of height in the freeboard. Aspect ratio increased as the location was closer to the surface of the dense phase, but decreased at the highest location. Solidity did not show any significant changes with height. The results showed the aggregates formation process is affected by the height in the freeboard. A correlation was proposed to predict the Heywood diameter of the CNT aggregates.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.4
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• pp.330-337
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• 2019

Effects of cyclone and freeboard geometry on solid entrainment loss were investigated with two different types of cyclones and bubbling beds in a gas-solid fluidized bed system. The solid entrainment loss was measured by collected fines during continuous solid circulation condition. Bubbling bed which has an expanded freeboard showed less solid entrainment than the bubbling bed which has a straight freeboard. The cyclone which has a wide gas-solid mixture inlet showed less solid entrainment loss than the cyclone which has a narrow gas-solid mixture inlet. Moreover, the cyclone has a wide gas-solid mixture inlet can capture smaller particles.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.711-714
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• 2009

Currently digital contents such as games, animation and video art are produced and distributed actively. And moreover by the development of related industries, a variety genre of media is in the process of planning and production. However general-purpose tools such as MAYA and Soft Image do not provide the artists in terms of a variety of unique functions. Thus in this study, we analyzed and developed interface technologies that can help effectively in terms of animation scenario writing, storyboard simulation, rendering and pre-production of story board, interface technology for preview. By our designed simulate planning, people who not professional in the field of animation, can produce and preview animation easily.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1998.05a
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• pp.173-176
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• 1998

FCC (Fluid Catalystic Cracking) 장치는 중질유의 원유와 잔사유로부터 가솔린과 heating oil. 디젤연료 제조 등에 사용되고 있다. 이 장치는 50년 동안 fine-powder 유동화에 중요하게 응용되고 있으며, 현재 세계적으로 약 350여 개의 장치가 조업되고 있다. FCC 장치에서 미세한 분해촉매는 촉매에 의한 중질유의 분해가 일어나는 상승관 (riser)과 촉매의 재생이 일어나는 재생반응기(regenerator) 사이에서 높은 속도로 순환되고 있다. (중략)

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.535-543
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• 2022

A CPFD (Computational particle fluid dynamics) model of solar fluidized bed receiver of silicon carbide (SiC: average d_p=123 ㎛) particles was established, and the model was verified by comparing the simulation and experimental results to analyze the effect of particle behavior on the performance of the receiver. The relationship between the heat-absorbing performance and the particles behavior in the receiver was analyzed by simulating their behavior near bed surface, which is difficult to access experimentally. The CPFD simulation results showed good agreement with the experimental values on the solids holdup and its standard deviation under experimental condition in bed and freeboard regions. The local solid holdups near the bed surface, where particles primarily absorb solar heat energy and transfer it to the inside of the bed, showed a non-uniform distribution with a relatively low value at the center related with the bubble behavior in the bed. The local solid holdup increased the axial and radial non-uniformity in the freeboard region with the gas velocity, which explains well that the increase in the RSD (Relative standard deviation) of pressure drop across the freeboard region is responsible for the loss of solar energy reflected by the entrained particles in the particle receiver. The simulation results of local gas and particle velocities with gas velocity confirmed that the local particle behavior in the fluidized bed are closely related to the bubble behavior characterized by the properties of the Geldart B particles. The temperature difference of the fluidizing gas passing through the receiver per irradiance (∆T/I_DNI) was highly correlated with the RSD of the pressure drop across the bed surface and the freeboard regions. The CPFD simulation results can be used to improve the performance of the particle receiver through local particle behavior analysis.

• Proceedings of the Korea Contents Association Conference
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• 2003.11a
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• pp.347-351
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• 2003

It is important to consider not only audio/video but presentation way, in video conferencing, seminar, lecture based network communication. The method to transmit image of a chalkboard used in traditional seminar, conference, lecture are one of difficulties for remote environment since it requires techniques high-resolution transmission and talking films. In this paper we implemented real-time multimedia shared board system for shared effective multimedia presentation using connection-oriented socket of TCP. In this system, decreasing cost of related system construction, improve of data reliableness and interaction, presentation delay time be able to minimize.

• Journal of the Korean Society of Combustion
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• v.16 no.4
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• pp.8-15
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• 2011

The present study investigates the combustion phenomena in a sludge incinerator using experimental and numerical method. The temperature and gas concentration were measured at 33 points during operation of the incinerator in order to assess the mixing and combustion characteristics. Numerical simulation was also carried out using a commercial CFD code. Simplified inlet conditions were introduced in oder to predict the bulk solid combustion and the diffusion of the volatile matter released by pyrolysis of sludge. The experimental results showed that the combustion process is extremely inhomogeneous. Large variations were observed in the temperature and gas concentrations in the freeboard of the incinerator due to poor mixing performance between the air and the combustibles, which is caused by massive and bulk generation of volatile matter by fast pyrolysis of sludge particles. The boundary condition of the CFD simulation was found effective in predicting the poor mixing and combustion performance of the reactor.

• Korean Chemical Engineering Research
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• v.59 no.2
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• pp.239-246
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• 2021

Characteristics of hydrodynamics and heat absorption by gas in a directly-irradiated fluidized bed particle receiver (50 mm-ID X 150 mm high) of SiC particles have been determined. Solid holdups of SiC particles show almost constant values with increasing gas velocity. Fine SiC particles (SiC II; dp=52 ㎛, ρs=2992 kg/㎥) showed low values of relative standard deviation of pressure drop across bed but high solids holdups in the freeboard region compared to coarse SiC particles (SiC I; dp=123 ㎛, ρs=3015 kg/㎥). The SiC II exhibited higher values of temperature difference normalized by irradiance due to the effect of additional solar heat absorption and heat transfer to the gas by the particles entrained in the freeboard region in addition to the efficient thermal diffusion of the solar heat received at bed surface. Heat absorption rate and efficiency increased with increasing the gas velocity and fluidization number. The SiC II showed maximum heat absorption rate of 17.8 W and thermal efficiency of 14.8%, which are about 33% higher than those of SiC I within the experimental gas velocity range.