A novel noncontact ultrasound indentation system for measurement of tissue material properties using water jet compression

Author name used in this publication: M. H. LuAuthor name used in this publication: Y. P. ZhengAuthor name used in this publication: Q. H. Huang2004-2005 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Ultrasound elastomicroscopy using water beam indentation : preliminary study

Author name used in this publication: M. H. LuAuthor name used in this publication: Y. P. ZhengAuthor name used in this publication: Q. H. Huang2004-2005 > Academic research: not refereed > Chapter in an edited book (author)Accepted ManuscriptPublishe

A novel method to obtain modulus image of soft tissues using ultrasound water jet indentation : a phantom study

2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Evaluation of bone-tendon junction healing using water jet ultrasound indentation method

2009-2010 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

3-D measurement of body tissues based on ultrasound images with 3-D spatial information

2005-2006 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Development of a portable 3D ultrasound imaging system for musculoskeletal tissues

Author name used in this publication: Q. H. HuangAuthor name used in this publication: Y. P. ZhengAuthor name used in this publication: M. H. LuAuthor name used in this publication: Z. R. ChiCentre for Signal Processing, Department of Electronic and Information EngineeringRehabilitation Engineering Centre2004-2005 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Effect of armature reaction of a permanent-magnet claw pole SMC motor

The finite-element method enables an accurate analysis for the study on effects of armature reaction in electromagnetic devices, particularly those with complex structures and three-dimensional (3-D) magnetic flux paths. This paper investigates the effects of armature reaction on the parameters and performance of a permanent-magnet (PM) claw pole motor with soft magnetic composite (SMC) core, based on the magnetic field analysis using the 3-D nonlinear time-stepping finite-element method. The current in the stator winding produces a magnetic field, which interacts with the air gap field generated by the rotor magnets. Consequently, the air gap flux density profile against the rotor position produced by the rotor magnets deviates, and so does the back electromotive force. Since the stator field also changes the local saturation level of the magnetic core, the winding inductance varies with both the rotor position and stator currents. The inclusion of these effects in terms of parameter variations in the motor model is important for accurate performance analysis. On the other hand, the pattern of inductance against the rotor position and stator currents can be employed to effectively predict the rotor position at standstill and low speeds for robust sensorless control. The parameter computations are verified by experimental results on the PM claw pole SMC motor prototype. © 2007 IEEE

DEM investigation of sand response during displacement pile installation

Previous experimental and numerical studies indicate that the stress state of sand at a specific depth changes significantly during the installation of a displacement pile. At a given depth level, the horizontal stress in sand increases as the end of pile approaches and reduces as the pile continues to penetrate and go past the sand element. This horizontal stress reversal, together with the large-strain deformation of the sand at the pile shaft, may cause a reduced accuracy in the calculation of pile capacity. In this paper, the micro-mechanical behaviour of sand developed around pile shaft during the installation of a closed-ended pile was studied using the two-dimensional Discrete Element Method (DEM). Sand assembly was modelled as uncrushable discs, and the closed-ended pile was modelled as a rigid clump which was made of a large number of overlapped discs with a fixed distance. The sand responses in terms of stress, strain and volume changes during the monotonic jacking of the closed-ended pile were investigated. Simulation results revealed micro-mechanical behaviours of the sand in both the interface zone “B” adjacent to the pile shaft and the far field zone “A” away from the pile. It was shown that the sand along the pile shaft at a small normalised distance to pile tip was subjected to a volume reduction as the pile goes past. As the pile drives deeper, the sand at a larger normalised distance to pile tip exhibited dilation. This captured process will give insights to the degradation of shaft friction at a given sand horizon

A new adaptive interpolation algorithm for 3D ultrasound imaging with speckle reduction and edge preservation

Author name used in this publication: Qinghua HuangAuthor name used in this publication: Yongping ZhengAuthor name used in this publication: Minhua Lu2008-2009 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

A low cost and reliable dimmable ballast topology with inherent power regulation and insensitivity to lamp characteristics

The output power of the proposed dimmable ballast topology is self-regulated and insensitive to the lamp characteristics. Accurate dimming operation with rather constant filament power can be realized simply by open loop control of the switching frequency of the converter. It can provide reliable operation during lamp ignition with fault conditions or even short circuit without the need of current sensing circuits. Prototype was built for experimental verifications. For completeness, a simple ultra low dimming method is also proposed together with the theoretical dimming limit considered. © 2005 IEEE.published_or_final_versio