guangyu zhu - Academia.edu (original) (raw)

Papers by guangyu zhu

Particle filter is a powerful visual tracking tool based on sequential Monte Carlo framework, and... more Particle filter is a powerful visual tracking tool based on sequential Monte Carlo framework, and it needs large numbers of samples to properly approximate the posterior density of the state evolution. However, its efficiency degenerates if too many samples are applied. In this paper, an improved particle filter is proposed by integrating support vector regression into sequential Monte Carlo framework to enhance the performance of particle filter with small sample set. The proposed particle filter utilizes an SVR based re-weighting scheme to re-approximate the posterior density and avoid sample impoverishment. Firstly, a regression function is obtained by support vector regression method over the weighted sample set. Then, each sample is re-weighted via the regression function. Finally, ameliorative posterior density of the state is re-approximated to maintain the effectiveness and diversity of samples. Experimental results demonstrate that the proposed particle filter improves the efficiency of tracking system effectively and outperforms classical particle filter.

IEEE Transactions on Consumer Electronics, 2007

IEEE Transactions on Multimedia, 2009

IEEE Transactions on Multimedia, 2008

IEEE Transactions on Multimedia, 2007

Guangyu Zhu 1, Changsheng Xu 2, Qingming Huang 3, Wen Gao 1, and Liyuan Xing 3 1 School of Comput... more Guangyu Zhu 1, Changsheng Xu 2, Qingming Huang 3, Wen Gao 1, and Liyuan Xing 3 1 School of Computer Science Harbin Institute of Technology Harbin, PR China, 150001 ... 2 Institute for Infocomm Research 21 Heng Mui Keng Terrace Singapore, 119613

... By extending the idea of local space-time features, space-time pyramids and mul-tichannel non... more ... By extending the idea of local space-time features, space-time pyramids and mul-tichannel non ... a compact representation extracted from the candidate region; 3) an event segmentation layer in ... Given the input video sequence, we first locate the candidate re-gions to analyze by ...

IEEE Transactions on Pattern Analysis and Machine Intelligence, 2009

Journal of Biotechnology, 2005

Biotechnology and Bioengineering, 2003

Nanoparticles provide an ideal remedy to the usually contradictory issues encountered in the opti... more Nanoparticles provide an ideal remedy to the usually contradictory issues encountered in the optimization of immobilized enzymes: minimum diffusional limitation, maximum surface area per unit mass, and high effective enzyme loading. In addition to the promising performance features, the unique solution behaviors of the nanoparticles also point to a transitional region between the heterogeneous (with immobilized enzymes) and homogeneous (with soluble free enzymes) catalysis. The particle mobility, which is related to particle size and solution viscosity through Stokes-Einstein equation, may impact the reaction kinetics according to the collision theory. The mobility-activity relationship was examined through experimental studies and theoretical modeling in the present work. Polystyrene particles with diameters ranging from 110–1000 nm were prepared. A model enzyme, α-chymotrypsin, was covalently attached to the nanoparticles up to 6.6 wt%. The collision theory model was found feasible in correlating the catalytic activities of particles to particle size and solution viscosity. Changes in the size of particles and the viscosity of reaction media, which all affect the mobility of the enzyme catalyst, evidently altered the intrinsic activity of the particle-attached enzyme. Compared to KM, kcat appeared to be less sensitive to particle size and viscosity. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng84: 406–414, 2003.

Journal of The American Chemical Society, 2004

Native water-soluble enzymes were transformed into interface-binding enzymes via conjugation with... more Native water-soluble enzymes were transformed into interface-binding enzymes via conjugation with hydrophobic polymers, thus enabling interesting interfacial biocatalysis between immiscible chemicals at oil/water interfaces. Such interfacial biocatalysis demonstrated a significantly improved catalytic efficiency as compared to traditional biphasic reactions with enzymes contained in the bulk aqueous phase. Particularly, polystyrene-conjugated beta-galactosidase showed a catalytic efficiency that was more than 145 times higher than that of the native enzyme for a transgalactosylation reaction. It is believed that the improved accessibility of the biocatalysts to chemicals held in both phases across the interface is the key driver for the enhancement of enzyme activity.

Bioresource Technology, 2005

Biotechnology Progress, 2002

Particle filter is a powerful visual tracking tool based on sequential Monte Carlo framework, and... more Particle filter is a powerful visual tracking tool based on sequential Monte Carlo framework, and it needs large numbers of samples to properly approximate the posterior density of the state evolution. However, its efficiency degenerates if too many samples are applied. In this paper, an improved particle filter is proposed by integrating support vector regression into sequential Monte Carlo framework to enhance the performance of particle filter with small sample set. The proposed particle filter utilizes an SVR based re-weighting scheme to re-approximate the posterior density and avoid sample impoverishment. Firstly, a regression function is obtained by support vector regression method over the weighted sample set. Then, each sample is re-weighted via the regression function. Finally, ameliorative posterior density of the state is re-approximated to maintain the effectiveness and diversity of samples. Experimental results demonstrate that the proposed particle filter improves the efficiency of tracking system effectively and outperforms classical particle filter.

IEEE Transactions on Consumer Electronics, 2007

IEEE Transactions on Multimedia, 2009

IEEE Transactions on Multimedia, 2008

IEEE Transactions on Multimedia, 2007

Guangyu Zhu 1, Changsheng Xu 2, Qingming Huang 3, Wen Gao 1, and Liyuan Xing 3 1 School of Comput... more Guangyu Zhu 1, Changsheng Xu 2, Qingming Huang 3, Wen Gao 1, and Liyuan Xing 3 1 School of Computer Science Harbin Institute of Technology Harbin, PR China, 150001 ... 2 Institute for Infocomm Research 21 Heng Mui Keng Terrace Singapore, 119613

... By extending the idea of local space-time features, space-time pyramids and mul-tichannel non... more ... By extending the idea of local space-time features, space-time pyramids and mul-tichannel non ... a compact representation extracted from the candidate region; 3) an event segmentation layer in ... Given the input video sequence, we first locate the candidate re-gions to analyze by ...

IEEE Transactions on Pattern Analysis and Machine Intelligence, 2009

Journal of Biotechnology, 2005

Biotechnology and Bioengineering, 2003

Nanoparticles provide an ideal remedy to the usually contradictory issues encountered in the opti... more Nanoparticles provide an ideal remedy to the usually contradictory issues encountered in the optimization of immobilized enzymes: minimum diffusional limitation, maximum surface area per unit mass, and high effective enzyme loading. In addition to the promising performance features, the unique solution behaviors of the nanoparticles also point to a transitional region between the heterogeneous (with immobilized enzymes) and homogeneous (with soluble free enzymes) catalysis. The particle mobility, which is related to particle size and solution viscosity through Stokes-Einstein equation, may impact the reaction kinetics according to the collision theory. The mobility-activity relationship was examined through experimental studies and theoretical modeling in the present work. Polystyrene particles with diameters ranging from 110–1000 nm were prepared. A model enzyme, α-chymotrypsin, was covalently attached to the nanoparticles up to 6.6 wt%. The collision theory model was found feasible in correlating the catalytic activities of particles to particle size and solution viscosity. Changes in the size of particles and the viscosity of reaction media, which all affect the mobility of the enzyme catalyst, evidently altered the intrinsic activity of the particle-attached enzyme. Compared to KM, kcat appeared to be less sensitive to particle size and viscosity. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng84: 406–414, 2003.

Journal of The American Chemical Society, 2004

Native water-soluble enzymes were transformed into interface-binding enzymes via conjugation with... more Native water-soluble enzymes were transformed into interface-binding enzymes via conjugation with hydrophobic polymers, thus enabling interesting interfacial biocatalysis between immiscible chemicals at oil/water interfaces. Such interfacial biocatalysis demonstrated a significantly improved catalytic efficiency as compared to traditional biphasic reactions with enzymes contained in the bulk aqueous phase. Particularly, polystyrene-conjugated beta-galactosidase showed a catalytic efficiency that was more than 145 times higher than that of the native enzyme for a transgalactosylation reaction. It is believed that the improved accessibility of the biocatalysts to chemicals held in both phases across the interface is the key driver for the enhancement of enzyme activity.

Bioresource Technology, 2005

Biotechnology Progress, 2002