Documents disponibles écrits par cet auteur

New rate-distortion modeling and efficient rate control for H.264/AVC video coding / Yimin Zhou in Signal processing. Image communication, Vol. 24 N° 5 (Mai 2009) 

Public ISBD [article]  in Signal processing. Image communication > Vol. 24 N° 5 (Mai 2009) . - pp. 345-356 Titre : New rate-distortion modeling and efficient rate control for H.264/AVC video coding Type de document : texte imprimé Auteurs : Yimin Zhou, Auteur ; Yu Sun, Auteur ; Zhidan Feng, Auteur Article en page(s) : pp. 345-356 Note générale : Electronique Langues : Anglais (eng) Mots-clés : Rate  control  H.264/AVC  compression  standard  Video  coding  Rate-distortion  model  Buffer  control Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : Rate control (RC) is crucial in controlling compression bit rates and qualities for networked video applications. In this paper, we propose a new rate-distortion (R-D) model and an efficient rate control scheme for H.264/AVC video coding, which elegantly resolve the inter-dependency problem between rate-distortion optimization and rate control by eliminating the need of coding complexity prediction for an inter-frame. The objective is to achieve accurate bit rate, obtain optimal video quality while reducing quality variations and simultaneously handling buffer fullness effectively. The proposed algorithm encapsulates a number of new features, including a coding complexity measure for intra-frames, a rate-distortion model, an accurate quantization parameter (QP) estimation for intra-frames, an incremental quantization parameter calculation method for inter-frames, a proportional+integral+derivative (PID) buffer controller, and an intelligent bit-allocation-balancing technique. Our experimental results demonstrate that the proposed scheme outperforms the JVT-G012 solution by providing accurate rate regulation, effectively reducing frame skipping, and finally improving coding quality by up to 1.80 dB. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...] [article] New rate-distortion modeling and efficient rate control for H.264/AVC video coding [texte imprimé] / Yimin Zhou, Auteur ; Yu Sun, Auteur ; Zhidan Feng, Auteur . - pp. 345-356. Electronique Langues : Anglais (eng) in Signal processing. Image communication > Vol. 24 N° 5 (Mai 2009) . - pp. 345-356 Mots-clés : Rate  control  H.264/AVC  compression  standard  Video  coding  Rate-distortion  model  Buffer  control Index. décimale : 621.382 Dispositifs électroniques utilisant les effets des corps solides. Dispositifs semi-conducteurs Résumé : Rate control (RC) is crucial in controlling compression bit rates and qualities for networked video applications. In this paper, we propose a new rate-distortion (R-D) model and an efficient rate control scheme for H.264/AVC video coding, which elegantly resolve the inter-dependency problem between rate-distortion optimization and rate control by eliminating the need of coding complexity prediction for an inter-frame. The objective is to achieve accurate bit rate, obtain optimal video quality while reducing quality variations and simultaneously handling buffer fullness effectively. The proposed algorithm encapsulates a number of new features, including a coding complexity measure for intra-frames, a rate-distortion model, an accurate quantization parameter (QP) estimation for intra-frames, an incremental quantization parameter calculation method for inter-frames, a proportional+integral+derivative (PID) buffer controller, and an intelligent bit-allocation-balancing technique. Our experimental results demonstrate that the proposed scheme outperforms the JVT-G012 solution by providing accurate rate regulation, effectively reducing frame skipping, and finally improving coding quality by up to 1.80 dB. DEWEY : 361.382 ISSN : 0923-5965 En ligne : http://www.sciencedirect.com/science?_ob=PublicationURL&_tockey=%23TOC%235640%23 [...]

Removal of trace olefins from aromatics at room temperature using pyridinium and imidazolium ionic liquids / Yu Sun in Industrial & engineering chemistry research, Vol. 50 N° 15 (Août 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 9339-9343 Titre : Removal of trace olefins from aromatics at room temperature using pyridinium and imidazolium ionic liquids Type de document : texte imprimé Auteurs : Yu Sun, Auteur ; Li Shi, Auteur Année de publication : 2011 Article en page(s) : pp. 9339-9343 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ionic  liquid Résumé : [BuPy]Br-AlCl3 and [BMIm]Br-AlCl3 were used to remove trace olefins from aromatics. At room temperature, almost 100% olefin conversion was obtained using [BuPy]Br-AlCl3 as the catalyst. The effects of the cation and the dosage of AlCl3 in the ionic liquid were investigated. It was found that the dosage of AlCl3 had a significant impact on the reaction, whereas the organic cation type mainly influenced the conversion. Anions in [BuPy]Br-AlCl3 such as AlCl4- and AlCl7- were shown to exist by ESI-MS, and the mechanism of the reaction catalyzed by [BuPy]Br-AlCl3 was studied. The investigation of various reaction parameters showed that the process saves time, consumes less energy, separates products more easily, and produces less pollution to the environment than conventional methods to remove trace olefins from aromatics. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395878 [article] Removal of trace olefins from aromatics at room temperature using pyridinium and imidazolium ionic liquids [texte imprimé] / Yu Sun, Auteur ; Li Shi, Auteur . - 2011 . - pp. 9339-9343. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 15 (Août 2011) . - pp. 9339-9343 Mots-clés : Ionic  liquid Résumé : [BuPy]Br-AlCl3 and [BMIm]Br-AlCl3 were used to remove trace olefins from aromatics. At room temperature, almost 100% olefin conversion was obtained using [BuPy]Br-AlCl3 as the catalyst. The effects of the cation and the dosage of AlCl3 in the ionic liquid were investigated. It was found that the dosage of AlCl3 had a significant impact on the reaction, whereas the organic cation type mainly influenced the conversion. Anions in [BuPy]Br-AlCl3 such as AlCl4- and AlCl7- were shown to exist by ESI-MS, and the mechanism of the reaction catalyzed by [BuPy]Br-AlCl3 was studied. The investigation of various reaction parameters showed that the process saves time, consumes less energy, separates products more easily, and produces less pollution to the environment than conventional methods to remove trace olefins from aromatics. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24395878

Research on reactive adsorption desulfurization over Ni/ZnO−SiO2−Al2O3 adsorbent in a fixed-fluidized bed reactor / Jingxin Fan in Industrial & engineering chemistry research, Vol. 49 N° 18 (Septembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8450–8460 Titre : Research on reactive adsorption desulfurization over Ni/ZnO−SiO2−Al2O3 adsorbent in a fixed-fluidized bed reactor Type de document : texte imprimé Auteurs : Jingxin Fan, Auteur ; Gang Wang, Auteur ; Yu Sun, Auteur Année de publication : 2010 Article en page(s) : pp. 8450–8460 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Desulfurization  Adsorption Résumé : Reactive adsorption desulfurization of FCC gasoline over a Ni/ZnO−SiO2−Al2O3 adsorbent was carried out in a fixed-fluidized bed reactor at low pressures in the presence of hydrogen. The results show that high temperature, high pressure, high molar ratios of hydrogen-to-oil, and low weight hourly space velocity are favorable to improve the desulfurization ability of adsorbent but not conducive to maintaining the octane number of FCC gasoline throughout the condition range examined. Under optimal operating conditions, ultralow sulfur gasoline can be produced, and the RON loss is only 1 unit. Furthermore, the effect of prereduction and adsorbent characterization data (SEM/EDX, N2 adsorption) reveal that reduction increases the interaction between Ni and S compounds and improves the pore structure of adsorbent, leading to a significant improvement in the desulfurization capability of adsorbent. Take 3-methylthiophene for example, after adsorbing on an active Ni atom via the S−Ni bond, the sulfur of 3-methylthiophene is removed by direct hydrogenolysis of the C−S bond, resulting in the formation of NiSx and 2-methyl-1,3-butadiene in hydrogen atmosphere. The latter is mainly hydrogenated to 2-methyl-2-butene and 2-methylbutane. ZnO acts as a sulfur-acceptor, which can regenerate the active Ni in situ in hydrogen atmosphere. The complete sulfidation of adsorbent particles takes place by ion diffusion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100923v [article] Research on reactive adsorption desulfurization over Ni/ZnO−SiO2−Al2O3 adsorbent in a fixed-fluidized bed reactor [texte imprimé] / Jingxin Fan, Auteur ; Gang Wang, Auteur ; Yu Sun, Auteur . - 2010 . - pp. 8450–8460. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8450–8460 Mots-clés : Desulfurization  Adsorption Résumé : Reactive adsorption desulfurization of FCC gasoline over a Ni/ZnO−SiO2−Al2O3 adsorbent was carried out in a fixed-fluidized bed reactor at low pressures in the presence of hydrogen. The results show that high temperature, high pressure, high molar ratios of hydrogen-to-oil, and low weight hourly space velocity are favorable to improve the desulfurization ability of adsorbent but not conducive to maintaining the octane number of FCC gasoline throughout the condition range examined. Under optimal operating conditions, ultralow sulfur gasoline can be produced, and the RON loss is only 1 unit. Furthermore, the effect of prereduction and adsorbent characterization data (SEM/EDX, N2 adsorption) reveal that reduction increases the interaction between Ni and S compounds and improves the pore structure of adsorbent, leading to a significant improvement in the desulfurization capability of adsorbent. Take 3-methylthiophene for example, after adsorbing on an active Ni atom via the S−Ni bond, the sulfur of 3-methylthiophene is removed by direct hydrogenolysis of the C−S bond, resulting in the formation of NiSx and 2-methyl-1,3-butadiene in hydrogen atmosphere. The latter is mainly hydrogenated to 2-methyl-2-butene and 2-methylbutane. ZnO acts as a sulfur-acceptor, which can regenerate the active Ni in situ in hydrogen atmosphere. The complete sulfidation of adsorbent particles takes place by ion diffusion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100923v