1,721,156 research outputs found
Design of bimetallic nanoparticles
Full text linkThis work was supported by Korean Research Foundation Grant(KRF-2003-003-D00087). The author(S.J.Cho) acknowledged the generous permission to use the synchortron radiation at the Pohang Accelerator Laboratory
Formation and growth of a nanosized RuIr bimetallic cluster supported on NaY zeolite
No full textA RuIr catalyst has been prepared by exchanging Ru and Ir metal ions simultaneously into NaY zeolite and then followed by thermal decomposition under a vacuum at 673 K and reduction with hydrogen at 623 K. The results obtained from the Xe adsorption measurement, hydrogen chemisorption, and X-ray absorption fine structure suggest that the RuIr bimetallic clusters are encapsulated in the supercage of NaY zeolite, consisting of 30-60 atoms/cluster. It has been found out that Ru and Ir atoms are homogeneously mixed in the bimetallic cluster. The nanosized RuIr bimetallic clusters in the NaY zeolite show strong resistance for the agglomeration in I-atm oxygen and at high temperatures, compared to the Ru/NaY
Bayesian network modeling of strokes and their relationships for on-line handwriting recognition
No full textIn this paper, we propose a Bayesian network framework for explicitly modeling strokes and their relationships of characters. A character is modeled as a composition of stroke models, and a stroke as a composition of point models. A point is modeled with 2-D Gaussian distribution for its X-Y position. Relationships between points and strokes are modeled as their positional dependencies. All the models and relationships are represented probabilistically in Bayesian networks. The recognition experiment with on-line handwritten digits showed promising results; the recognition errors of the proposed system were greatly reduced by dependency modeling, and its recognition rates were higher than those of previous methods. (C) 2003 Pattern Recognition Society. Published by Elsevier Ltd. All rights reserved
Design of bimetallic nanoparticles
No full textA novel preparation method to control a microstructure and the resulting structure and activity relationship are presented to aim a rational design of the well defined bimetallic nanoparticles. Nanoparticles are engineered inside the supercage of faujasite type zeolite. The reduction mechanism for the bimetallic nanoparticles is proposed based on the results of X-ray absorption fine structure, Xe-129 NMR spectrum and transmission electron micrograph. The chemical properties have been modified and also the catalytic performance has been altered through the generation of well defined bimetallic nanoparticles. The principle of the design of bimetallic nanoparticles has also been extended for other open substrates. The state of the art technology for the fabrication method presented here provides advanced firm basis for the development of the bimetallic nanoparticles with novel function
Texture coding using 2D-DCT based on extension/interpolation (EI)
No full textIn this paper, a new method capable of effectively coding arbitrarily-shaped image regions is presented. The image region is spanned into the 8 x 8 rectangular block and its intermediate luminances are interpolated. After all luminances in the 8 x 8 block are obtained from pixels in the region, they are transformed by 8 x 8 DCT. The proposed extension/interpolation (EI) method is compared with conventional ones, such as SA-DCT[4], mean stuffing, etc., under three aspects: peak signal-to-noise ratio (PSNR), hardware complexity, and the flexibility for improvement of performance. Simulation results show that the performance of the proposed method is superior to that of the conventional ones. In addition, we introduce an improved version by repetitively performing the EI method
Effect of multivalent cations on agglomeration of Ru clusters supported on Y zeolite
No full textThe effect of multivalent cations. Ca2+, Ba2+, Y3+ , Ce3+ and La3+ on the agglomeration of Ru clusters on NaY zeolite under oxygen and at high temperature has been investigated with Xe-129 NMR spectroscopy and X-ray absorption fine structure. Multivalent metal cations exchanged into the zeolite suppress neither the migration nor agglomeration of small Ru clusters inside the supercage of NaY zeolite into large metal panicles onto the external surface of NaY zeolite under 1 atm oxygen above 520 K. However, the resultant Ru particle size depends on the type of metal cations exchanged into NaY zeolite
VERIFICATION OF GRAPHEMES USING NEURAL NETWORKS IN AN HMM-BASED ON-LINE KOREAN HANDWRITING RECOGNITION SYSTEM
No full textOn-Line Signature Verification Using Model-Guided Segmentation and Discriminative Feature Selection for Skilled Forgeries
No full textGeneration of Handwritten Characters with Bayesian network based On-line Handwriting Recognizers
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