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Scientometrics - The article published on 5 July 2021 is well-written and of interest. However, some improvements could be made, such as ten Tables/Figures can be shortened to highlight the focused... 相似文献
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Analysis and architecture design of variable block-size motion estimation for H.264/AVC 总被引:1,自引:0,他引:1
Ching-Yeh Chen Shao-Yi Chien Yu-Wen Huang Tung-Chien Chen Tu-Chih Wang Liang-Gee Chen 《IEEE transactions on circuits and systems. I, Regular papers》2006,53(3):578-593
Variable block-size motion estimation (VBSME) has become an important video coding technique, but it increases the difficulty of hardware design. In this paper, we use inter-/intra-level classification and various data flows to analyze the impact of supporting VBSME in different hardware architectures. Furthermore, we propose two hardware architectures that can support traditional fixed block-size motion estimation as well as VBSME with less chip area overhead compared to previous approaches. By broadcasting reference pixel rows and propagating partial sums of absolute differences (SADs), the first design has the fewer reference pixel registers and a shorter critical path. The second design utilizes a two-dimensional distortion array and one adder tree with the reference buffer that can maximize the data reuse between successive searching candidates. The first design is suitable for low resolution or a small search range, and the second design has advantages of supporting a high degree of parallelism and VBSME. Finally, we propose an eight-parallel SAD tree with a shared reference buffer for H.264/AVC integer motion estimation (IME). Its processing ability is eight times of the single SAD tree, but the reference buffer size is only doubled. Moreover, the most critical issue of H.264 IME, which is huge memory bandwidth, is overcome. We are able to save 99.9% off-chip memory bandwidth and 99.22% on-chip memory bandwidth. We demonstrate a 720-p, 30-fps solution at 108 MHz with 330.2k gate count and 208k bits on-chip memory. 相似文献
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ESR spin trapping was used to investigate the reaction of rabbit cytochrome P450 (P450) 1A2 with cumene hydroperoxide. Cumene hydroperoxide-derived peroxyl, alkoxyl, and carbon-centered radicals were formed and trapped during the reaction. The relative contributions of each radical adduct to the composite ESR spectrum were influenced by the concentration of the spin trap. Computer simulation of the experimental data obtained at various 5,5-dimethyl-1-pyrroline N-oxide (DMPO) concentrations was used to quantitate the contributions of each radical adduct to the composite ESR spectrum. The alkoxyl radical was the initial radical produced during the reaction. Experiments with 2-methyl-2-nitrosopropane identified the carbon-centered adducts as those of the methyl radical, hydroxymethyl radical, and a secondary carbon-centered radical. The reaction did not require NADPH-cytochrome P450 reductase or NADPH. It is concluded that the reaction involves the initial homolytic scission of the peroxide O-O bond to produce the cumoxyl radical. Methyl radicals were produced from the beta-scission of the cumoxyl radical. The peroxyl adduct was not observed in the absence of molecular oxygen. We conclude that the DMPO peroxyl radical adduct detected in the presence of oxygen was due to the methylperoxyl radical formed by the reaction of the methyl radical with oxygen. At a higher P450 concentration, a protein-derived radical adduct was also detected. 相似文献
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The Synthesis of Sulfated Titanium Oxide Nanotubes 总被引:1,自引:0,他引:1
Chiu-Hsun Lin Shu-Hua Chien Jiunn-Hsing Chao Chyi-Yang Sheu Yu-Cheng Cheng Ya-Jean Huang Chih-Hsiang Tsai 《Catalysis Letters》2002,80(3-4):153-159
TiO2 nanotubes can be prepared in gram quantities by treating anatase TiO2 powder with concentrated NaOH solution. These TiO2 nanotubes acquired strong acidity after being impregnated with sulfuric acid solution and calcined at 300 °C. The anatase TiO2 powder used to prepare the nanotube did not catalyze the esterification between cyclohexanol and acetic acid, while sulfated TiO2 nanotubes were very reactive toward the esterification reaction. 相似文献
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W. -M. Chien D. Chandra A. K. Helmy J. Franklin C. J. Rawn 《Journal of Phase Equilibria and Diffusion》2005,26(2):115-123
The solid-state phase transitions in ammonium nitrate (AN)-potassium nitrate (KN) system, and the equilibrium AN-KN phase
diagram have been determined by using differential scanning calorimetry and high-temperature in situ x-ray diffractometry.
Sample preparation was performed in a special “dry room” with very low humidity. A single phase region (AN III) with no phase
transitions to 373 K was observed in the composition range 5 to 20% KN; this is critical for use in air bag gas generators.
The high-temperature KN phase (KN I) has a wide range of stability from 20 to 100 wt.% KN. There are one eutectic, two eutectoid,
three peritectoid, and one congruent transformations in this phase diagram. Two new nonstoichiometric phases were found at
lower temperatures in the mid-composition range between the AN and KN terminal solid solutions. Details of the phase equilibria
are presented. 相似文献