• Title/Summary/Keyword: Multi-diffusion

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Synthesis of Multi-walled Carbon Nanotubes and Nanofibers on a Catalytic Metal Substrate Using an Ethylene Inverse Diffusion Flame as a Heat Source (에틸렌 역확산화염을 열원으로 사용하여 촉매금속 기판 상에 합성한 탄소나노튜브와 탄소나노섬유)

  • Lee, Gyo-Woo;Jurng, Jong-Soo;Kang, Kyung-Tae;Hwang, Jung-Ho
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1304-1309
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    • 2004
  • Synthesis of carbon nanotubes and nanofibers on a catalytic metal substrate, using an ethylene fueled inverse diffusion flame, was investigated. Multi-walled carbon nanotubes, with diameters of 20 - 60nm, were formed on the substrate coated with nickel-nitrate in the region of 5 - 6mm from the flame center along the radial direction. The gas temperature for this region was ranging from about 1400 to 900K. Nickel particles originated from the coated nickel-nitrate on the substrate were the major catalyst for the formation of the nanomaterials. HR-TEM and Raman spectrum revealed that synthesized carbon nanotubes had multi-walled structures with some defective graphite layers at walls.

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Emission rates of VOCs/VVOCs from multi-layers and their impacts on indoor air quality of Apartments (마감공사후 경과시간에 따른 복합마감재의 VOCs/VVOCs 방출량과 실내농도에 관한 연구)

  • Yoon, Chang-Hyun;Kwon, Kyung-Woo;Park, Jun-Seok
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.295-300
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    • 2006
  • The purpose of this study is to evaluate the impacts of finishing materials' VVOCs and VOCs emission rates on indoor air quality of Apartment. VOCs emission rate of multi-layer finishing is predicted using the effective diffusion coefficient of each materials, and then the prediction is compared with Mock-up test and sample apartment house. From the results, the prediction of multi-layer finishing using the effective diffusion coefficient show good relation with the measured values.

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Demand Forecasting with Discrete Choice Model Based on Technological Forecasting

  • 김원준;이정동;김태유
    • Proceedings of the Technology Innovation Conference
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    • 2003.02a
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    • pp.173-190
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    • 2003
  • Demand forecasting is essential in establishing national and corporate strategy as well as the management of their resource. We forecast demand for multi-generation product using discrete choice model combining diffusion model The discrete choice model generally captures consumers'valuation of the product's qualify in the framework of a cross-sectional analysis. We incorporate diffusion effects into a discrete choice model in order to capture the dynamics of demand for multi-generation products. As an empirical application, we forecast demand for worldwide DRAM (dynamic random access memory) and each of its generations from 1999 to 2005. In so doing, we use the method of 'Technological Forecasting'for DRAM Density and Price of the generations based on the Moore's law and learning by doing, respectively. Since we perform our analysis at the market level, we adopt the inversion routine in using the discrete choice model and find that our model performs well in explaining the current market situation, and also in forecasting new product diffusion in multi-generation product markets.

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Multi-level Vector Error Diffusion for Smear Artifact Reduction in the Boundary Regions (경계 영역에서 색 번짐 감소를 위한 멀티레벨 벡터 오차 확산법)

  • 박태용;조양호;김윤태;하영호
    • Proceedings of the IEEK Conference
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    • 2003.11a
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    • pp.461-464
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    • 2003
  • This paper proposes the multi-level vector error diffusion for smear artifact reduction in the boundary regions. Smear artifact mainly results from a large accumulation of quantization error. Accordingly, to reduce these artifacts, the proposed method excludes the large quantization error in the error diffusion process by comparing the magnitude of the error vector with predetermined first threshold. In addition, if the vector norm of the difference between the error adjusted input vector and the primary co]or that has minimum vector norm for the error adjusted input vector is larger than second threshold, the error is excluded. As a result, the proposed method reduce smear artifact in the boundary region and produces visually pleasing halftone pattern.

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Studies on the Multi-Layered Gelatin Diagnostic Membranes for Diabetes(2) : Effects of Interferents in Blood on the Diffusion-Controlled Rates of Glucose (당뇨병 진단을 위한 다층 젤라틴 진단막에 관한연구(2): 혈액속의 첨가물의 글루코우즈의 확산조절 속도에 미치는영향)

  • 권석기
    • Membrane Journal
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    • v.9 no.4
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    • pp.240-244
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    • 1999
  • Diagnostic membranes which were made of multi-layered gelatin films were prepared to measure the concentration of glucose in solution. It was found that the maximum diffusion rate of glucose had a linear relationship toward the glucose concentration. The effects of possible interferents in human blood on the reaction between glucose and reductive enzymes were examined. As a result, most of the interferents did not affect seriously on the maximum diffusion rate of glucose.

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An Empirical Study on the EDI Diffusion and Performance (EDI 시스템의 확산과 성과에 관한 실증적 연구)

  • Lee, Jae-Won;Lee, Young-Hwan
    • Asia pacific journal of information systems
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    • v.10 no.4
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    • pp.1-20
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    • 2000
  • Electronic Data Interchange(EDI) has the potential to improve business operations by expediting the exchange of business documents. It will also provide substantive operational and strategic benefits to the trading firms. However, the successful implementation of EDI systems requires the mutual trust and cooperation between the trading firms. The extent of EDI diffusion and performance depends on inter-organizational, intra-organizational, as well as innovation factors. Researches based on the sociopolitical process framework in the use of IT, organizational theory, resource dependence theory, and innovation diffusion theory have identified 3 inter-organizational variables(transaction climate, dependence, external IS expert support) and 4 intra-organizational variables(strategic IS planning, infrastructure, top management support, education/training,), and 3 innovation variables(compatibility, relative advantage, cost) that affect EDI diffusion. In this study, a multi-dimensional measure on EDI diffusion has been developed to capture the external and internal integration. Then, the influence of these 10 variables on the extent to which the EDI adopting firms pursue diffusion has been examined. Whether more diffusion leads to superior performance has also been studied. International trade managers from 107 firms in the trade industry participated in a field survey. The results based on a structural equation model(SEM), developed using AMOS, provide quite a strong support for the hypothesized relations. Both education/training and IT infrastructure influenced external and internal diffusion of EDI systems. Internal diffusion of EDI enables the adopting firms to improve operational and strategic performance, whereas external diffusion contributes only to operational performance.

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Multi-scale Diffusion-based Salient Object Detection with Background and Objectness Seeds

  • Yang, Sai;Liu, Fan;Chen, Juan;Xiao, Dibo;Zhu, Hairong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.10
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    • pp.4976-4994
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    • 2018
  • The diffusion-based salient object detection methods have shown excellent detection results and more efficient computation in recent years. However, the current diffusion-based salient object detection methods still have disadvantage of detecting the object appearing at the image boundaries and different scales. To address the above mentioned issues, this paper proposes a multi-scale diffusion-based salient object detection algorithm with background and objectness seeds. In specific, the image is firstly over-segmented at several scales. Secondly, the background and objectness saliency of each superpixel is then calculated and fused in each scale. Thirdly, manifold ranking method is chosen to propagate the Bayessian fusion of background and objectness saliency to the whole image. Finally, the pixel-level saliency map is constructed by weighted summation of saliency values under different scales. We evaluate our salient object detection algorithm with other 24 state-of-the-art methods on four public benchmark datasets, i.e., ASD, SED1, SED2 and SOD. The results show that the proposed method performs favorably against 24 state-of-the-art salient object detection approaches in term of popular measures of PR curve and F-measure. And the visual comparison results also show that our method highlights the salient objects more effectively.

Coupled diffusion of multi-component chemicals in non-saturated concrete

  • Damrongwiriyanupap, Nattapong;Li, Linyuan;Xi, Yunping
    • Computers and Concrete
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    • v.11 no.3
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    • pp.201-222
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    • 2013
  • A comprehensive simulation model for the transport process of fully coupled moisture and multi-species in non-saturated concrete structures is proposed. The governing equations of moisture and ion diffusion are formulated based on Fick's law and the Nernst-Planck equation, respectively. The governing equations are modified by explicitly including the coupling terms corresponding to the coupled mechanisms. The ionic interaction-induced electrostatic potential is described by electroneutrality condition. The model takes into account the two-way coupled effect of moisture diffusion and ion transport in concrete. The coupling parameters are evaluated based on the available experimental data and incorporated in the governing equations. Differing from previous researches, the material parameters related to moisture diffusion and ion transport in concrete are considered not to be constant numbers and characterized by the material models that account for the concrete mix design parameters and age of concrete. Then, the material models are included in the numerical analysis and the governing equations are solved by using finite element method. The numerical results obtained from the present model agree very well with available test data. Thus, the model can predict satisfactorily the ingress of deicing salts into non-saturated concrete.

Improved Routing Algorithm for Enhancing Survivability in Wireless Sensor Networks (무선 센서 네트워크의 생존성 강화를 위한 개선된 라우팅 알고리즘)

  • Choi, Seung-Kwon;Lee, Byong-Rok;Jang, Yoon-Sik;Kim, Tae-Hoon;Ji, Hong-Il
    • The Journal of the Korea Contents Association
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    • v.7 no.9
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    • pp.100-107
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    • 2007
  • This paper proposes and efficient routing scheme named MP-DD(MultiPath-Direct Diffusion) which are simple enough to be applicable to the wireless sensor networks. Conventional DD(Direct Diffusion) uses only one optimal path, therefore it consumes more energy of specific nodes. MP-DD uses multiple path and has a information of hop upstream node in the direction of the base-station. Simulation results show that the proposed scheme can increase network survivability compared to conventional DD and EAR(Energy Aware Routing) schemes.