• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.491-492
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• 2009

This paper presents evaluation results of fiber dispersion, number of fibers in a unit area, fiber orientation according to the mix-proportion of ECC and bridging stress calculated on the basis of fiber distribution characteristics.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.356-358
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• 2000

ISC3는 EPA가 권장하는 가우시안 대기확산 모델로서 일반적으로 공장 배출원으로 인한 일정 기간동안의 대기확산농도와 범위를 예측하기 위하여 사용되어진다. ISC3 모델은 다양한 점오염원, 면오염원, 등을 취급할 수 있을 뿐 아니라 building wake와 down wash 그리고 거리의 함수로써 final plum rise를 옵션으로 사용할 수 있고 단순지형이나 복합지형의 고려가 가능하다. ISC3 모델은 단순지형 장기모델인 ISCLT3와 복합지형 단기모델인 ISCST3가 있으며 모델의 수행에 있어 약간의 차이점이 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.181-182
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• 2000

경제성장과 더불어 환경에 대한 일반인들의 관심이 증가되어 기존의 환경기준 대상 오염물질 위주의 대기질 평가 외에 소음이나 악취 등의 감각공해에 대한 체계적인 연구가 필요하게 되었다. 악취에 의한 오염은 인간이 오감을 통해서 느끼는 정신적 피해의 하나로 청각을 통한 소음문제, 미각을 통한 음용수문제, 시각을 통한 경관의 문제 등과 같은 감각공해 중 대표적인 오염현상으로 생활환경의 쾌적성과 밀접한 관계를 갖고 있다. (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.105-106
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• 2002

산업이 발달함에 따라 대기 환경의 중요성이 강조되면서 대기 확산 모델을 이용하여 오염물질의 영향을 파악하는 일이 많아졌다. 그러나 대기 확산 모델은 수치계산으로 나온 값으로 자연현상의 모든 영향을 파악하기 어렵다는 한계점을 가지고 있다. 이러한 대기 확산 모델이 자연현상을 어느 정도 반영하는가를 평가하기 위해서는 추적자 물질을 이용하여 대기 오염물질의 확산 농도를 측정한 실측자료를 통하여 기존 모델을 평가하고 개선하는 것이 일반적인 방법이다. (중략)

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.67-67
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• 2011

퍼멀로이의 내식성, 기계적 성질 등을 증가시키기 위해 복합도금을 실시하였다. 실리카 나노분말의 분산특성을 Zeta potential을 이용하여 측정하였으며 알칼리 도금액에서 퍼멀로이-실리카 복합도금을 실시하였다. 실리카 나노분말의 응집을 최소로 하기 위하여 전극의 RPM 변화, 첨가제와 초음파의 복합처리에 따른 변화, 전류 밀도 변화를 살펴보았다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.9
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• pp.895-900
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• 2012

This paper aims to examine the effect of nanodroplets on pool-type absorption heat transfer enhancement and to find the relationship between the dispersion stability and the absorption performance. The concentrations of oil and surfactant are considered as the key parameters. $C_{12}E_4$ and Tween20 are used as the surfactants and N-decane oil is added to the $NH_3/H_2O$ solution to make the binary nanoemulsion fluids. Binary nanoemulsion fluids are dispersed by the ultrasonic vibrator and the stirrer under specific conditions. The dispersion stability of binary nanoemulsion fluids for each oil concentrations is evaluated from the droplet size and Tyndall effect analysis. The absorption performance of binary nanoemulsion fluids is compared with the result of dispersion stability. In addition, it is found that the binary nanoemulsion fluid is a strong candidate as a new working fluid for absorption applications.

• Nuclear Engineering and Technology
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• v.49 no.5
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• pp.1044-1062
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• 2017

The construction project of the Kijang research reactor (KJRR), which is the second research reactor in Korea, has been launched. The KJRR was designed to use, for the first time, U-Mo fuel. Plate-type U-7 wt.% Mo/Al-5 wt.% Si, referred to as U-7Mo/Ale5Si, dispersion fuel with a uranium loading of $8.0gU/cm^3$, was selected to achieve higher fuel efficiency and performance than are possible when using $U_3Si_2/Al$ dispersion fuel. To qualify the U-Mo fuel in terms of plate geometry, the first miniplates [HANARO Miniplate (HAMP-1)], containing U-7Mo/Al-5Si dispersion fuel ($8gU/cm^3$), were fabricated at the Korea Atomic Energy Research Institute and recently irradiated at HANARO. The PIE (Post-irradiation Examination) results of the HAMP-1 irradiation test were analyzed in depth in order to verify the safe in-pile performance of the U-7Mo/Al-5Si dispersion fuel under the KJRR irradiation conditions. Nondestructive analyses included visual inspection, gamma spectrometric mapping, and two-dimensional measurements of the plate thickness and oxide thickness. Destructive PIE work was also carried out, focusing on characterization of the microstructural behavior using optical microscopy and scanning electron microscopy. Electron probe microanalysis was also used to measure the elemental concentrations in the interaction layer formed between the U-Mo kernels and the matrix. A blistering threshold test and a bending test were performed on the irradiated HAMP-1 miniplates that were saved from the destructive tests. Swelling evaluation of the U-Mo fuel was also conducted using two methods: plate thickness measurement and meat thickness measurement.

• Journal of the Korea Institute of Building Construction
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• v.17 no.6
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• pp.517-525
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• 2017

Red mud is an industrial by-product produced during the manufacturing aluminum hydroxide ($Al(OH)_3$) and aluminum oxide($Al_2O_3$) from Bauxite ores. In Korea, approximately 2 tons of red mud in a sludge form with 50% moisture content is produced when 1ton of $Al_2O_3$ is produced through the Bayer process. In the paper, dispersion characteristics of liquefied red mud that does not require heating and grinding process for recycling were investigated through viscosity and sediment index. The results showed that the sediment index of liquefied red mud increased but viscosity of that decreased with a higher W/R ratio. Also we proposed the range of initial viscosity from 2000cP to 8000cP and target sedimentation index below 20% at elapsed time 180days for stable dispersion of liquefied red mud.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.91-97
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• 2016

This paper evaluates the equalization algorithm of FC-MMA (Fast Convergence-Multi Modulus Algorithm) and RMMA (Region based Multi Modulus Algorithm) for the compensation of intersymbol interference which is due to the distortion of communication channel. In order to obtain the error signal for adaptive equalization, the FC-MMA use the modified dispersion constant considering the number of signal symbol, the RMMA separates the 4 region which every symbol points are located, then reduce the symbol point based on this region into constant modulus symbol point. By applying the different principle in order to get the error signal for the updating the tap coefficient of adaptive equalizer, it has the different equalization performance by these error signal. The computer simulation was performed in order to compare the different equalization performance in this paper. The performance index includes the output signal constellation, the residual isi and maximum distortion that is for the convergence characteristics, the SER. As a result of computer simulation, RMMA has more good performance in the residual isi, maximum distortion after in steady state and SER performance than FC-MMA, but not in convergence speed to reach the steady state.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.2
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• pp.61-68
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• 2018

This study was conducted to propose the optimum minimum requirement of cutoff system composed of the impermeable soil layer and vertical barrier in offshore landfill for prevention pollution leakage by seepage, advection, and dispersion numerical analyses under steady state. According to the study results, the minimum requirement of impermeable soil layer is below $1{\times}10^{-6}cm/s$ of hydraulic conductivity with more than 500 cm thickness or a system with equivalent cutoff effect. The minimum requirement of vertical barrier is below $1{\times}10^{-6}cm/s$ of hydraulic conductivity with more than 50 cm thickness or a system with equivalent cutoff effect. In addition, the vertical barrier should be embedded enough to seal securely with the impermeable soil layer for working cutoff effect.