Tracer kinetic modeling of ¹¹C-acetate applied in the liver with positron emission tomography

Author name used in this publication: Dagan FengAuthor name used in this publication: Zheru ChiCentre for Multimedia Signal Processing, Department of Electronic and Information Engineering2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Document image matching based on component blocks

Author name used in this publication: David Dagan FengAuthor name used in this publication: Zheru ChiRefereed conference paper2000-2001 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

Pre-classification module for an all-season image retrieval system

Author name used in this publication: Zheru ChiAuthor name used in this publication: Dagan FengCentre for Multimedia Signal Processing, Department of Electronic and Information EngineeringRefereed conference paper2007-2008 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

An Immersed Boundary based method for studying thermal interaction of particles in a viscous fluid

The results of thermal interactions between a solid particle and a fluid have two folds: the motion of fluid affects the heat transfer and energy balance of a particle; and the heat transfer from particles influences the fluid motion. When the temperature of a particle and its surrounding fluid is not the same, heat is transferred between the particle and the fluid. The heat flux influences the properties of the surrounding fluid and changes the dynamics of the sedimentation of the particle. To study the effect of non-isothermal flows to the motion of a particle, we have developed a Direct Numerical Simulation (DNS) method that is capable of solving both the momentum equation and heat transfer equation for the computation of thermal interaction between particles and fluid. This numerical method makes use of a finite difference method in combination with the Immersed Boundary (IB) method for treating the particulate phase. In particular, the IB concept has been extended to treat thermal boundary condition at the particle surface. A regular Eulerian grid is used to solve the modified momentum and energy equations for the entire flow region simultaneously. In the region that is occupied by the solid particles, a second particle-based Lagrangian grid is used, which tracks particles, and a force density function or an energy density function is introduced to represent the momentum interaction or thermal interaction between particle and fluid. In this paper, the IB based DNS method has been applied to study the fluidization of 12,000 circular particles, the unsteady conduction of a sphere in a stagnant fluid, and the sedimentation of a non-isothermal sphere in a viscous fluid at different Grashof number. Our simulation results show that the sedimentation velocity of the particle depends strongly on the thermal interaction of particle and fluid due to the strong buoyancy force exerted on the particle. Copyright © 2010 by ASME

Hypergraph-based saliency map generation with potential region-of-interest approximation and validation

Author name used in this publication: Zheru ChiAuthor name used in this publication: Dagan Feng2011-2012 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Study of pulsatile pressure-driven electroosmotic flows through an elliptic cylindrical microchannel with the Navier slip condition

This paper aims to study an unsteady electric field-driven and pulsatile pressure-driven flow of a Newtonian fluid in an elliptic cylindrical microchannel with Navier boundary wall slip. The governing equations of the slip flow and distributions of electric potential and charge densities are the modified Navier-Stokes equations, the Poisson equation and the Nernst-Planck equations, respectively. Analytical and numerical analyses based on the Mathieu and modified Mathieu equations are performed to investigate the interplaying effects of pulsatile pressure gradients and the slip lengths on the electroosmotic flow

Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

The decay channel $\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p})$ is studied using a sample of $1.06\times 10^8$ $\psi^\prime$ events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the $p\bar{p}$ invariant mass spectrum. The enhancement can be fit with an $S$-wave Breit-Wigner resonance function with a resulting peak mass of $M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2$ and a narrow width that is $\Gamma<38 {\rm MeV/}c^2$ at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics

A Policy-Driven Large Scale Ecological Restoration: Quantifying Ecosystem Services Changes in the Loess Plateau of China

As one of the key tools for regulating human-ecosystem relations, environmental conservation policies can promote ecological rehabilitation across a variety of spatiotemporal scales. However, quantifying the ecological effects of such policies at the regional level is difficult. A case study was conducted at the regional level in the ecologically vulnerable region of the Loess Plateau, China, through the use of several methods including the Universal Soil Loss Equation (USLE), hydrological modeling and multivariate analysis. An assessment of the changes over the period of 2000–2008 in four key ecosystem services was undertaken to determine the effects of the Chinese government's ecological rehabilitation initiatives implemented in 1999. These ecosystem services included water regulation, soil conservation, carbon sequestration and grain production. Significant conversions of farmland to woodland and grassland were found to have resulted in enhanced soil conservation and carbon sequestration, but decreased regional water yield under a warming and drying climate trend. The total grain production increased in spite of a significant decline in farmland acreage. These trends have been attributed to the strong socioeconomic incentives embedded in the ecological rehabilitation policy. Although some positive policy results have been achieved over the last decade, large uncertainty remains regarding long-term policy effects on the sustainability of ecological rehabilitation performance and ecosystem service enhancement. To reduce such uncertainty, this study calls for an adaptive management approach to regional ecological rehabilitation policy to be adopted, with a focus on the dynamic interactions between people and their environments in a changing world