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Full-Text Articles in Engineering
Discrete Cosine Transform Based Shift Estimation For Fringe Pattern Profilometry Using Generalized Analysis Model, Jose F. Chicharo, Jiangtao Xi, Yingsong Hu, Zongkai Yang, Enbang Li
Discrete Cosine Transform Based Shift Estimation For Fringe Pattern Profilometry Using Generalized Analysis Model, Jose F. Chicharo, Jiangtao Xi, Yingsong Hu, Zongkai Yang, Enbang Li
Faculty of Engineering - Papers (Archive)
This paper presents a new analysis algorithm to carry out profile measure- ment with low computational complexity and less noise-sensitivity. Firstly, a discrete cosine transform (DCT) based representation method is introduced to express the height distribution of the three-dimensional surface. Then, a novel shift estimation algorithm, called DCT based shift estimation (DCT-SE) is presented to reconstruct three-dimensional object surfaces by using the proposed expression and the generalized analysis model. The advantage of DCT-SE is that without loss of measurement precise it provides lower computational complexity to implement three-dimensional reconstruction from distorted fringe patterns and at the same time survives from …
Experimental Evaluation Of Adaptive And Variable Structure Control Of Piezoelectric Actuation Systems For Micro/Nano Manipulation, Hwee Choo Liaw, Bijan Shirinzadeh, Denny Oetomo, Gursel Alici
Experimental Evaluation Of Adaptive And Variable Structure Control Of Piezoelectric Actuation Systems For Micro/Nano Manipulation, Hwee Choo Liaw, Bijan Shirinzadeh, Denny Oetomo, Gursel Alici
Faculty of Engineering - Papers (Archive)
This paper proposes and evaluates an adaptive technique and a variable structure control approach for piezoelectric actuation systems to track specified motion trajectories. The proposed control methodologies are formulated to accommodate unknown or uncertain system parameters, nonlinearities including the hysteresis effect, and external disturbances in the piezoelectric actuation systems without any form of feed-forward compensation. In this study, both control methodologies are demonstrated to possess a promising motion tracking ability experimentally. In comparison, the variable structure control approach is evaluated to be superior to the adaptive technique in the motion tracking control. With the ability to track motion trajectories under …
Membrane Bioreactor Technology For Decentralised Wastewater Treatment, Nichanan Tadkaew, Long Nghiem, Muttucumaru Sivakumar
Membrane Bioreactor Technology For Decentralised Wastewater Treatment, Nichanan Tadkaew, Long Nghiem, Muttucumaru Sivakumar
Faculty of Engineering - Papers (Archive)
Driven by stricter environmental regulations and legalisation on wastewater discharge and shrinking fresh water resources, water treatment has become an area of significant concern while at the same time there is a growing interest in utilising non-traditional water resources by means of water reclamation and water recycling.
Contact State Determination For Robotic-Based Cylindrical Pair Height Adjustment Under Dynamic Conditions, Prasan I. De Waas Tilakaratna, Bijan Shirinzadeh, Gursel Alici
Contact State Determination For Robotic-Based Cylindrical Pair Height Adjustment Under Dynamic Conditions, Prasan I. De Waas Tilakaratna, Bijan Shirinzadeh, Gursel Alici
Faculty of Engineering - Papers (Archive)
This paper investigates fine motion strategies associated with the height adjustment manipulations of a cylindrical pair which can be utilised in dynamic assembly and reconfigurable workholding systems. The outer link of the cylindrical pair is held by the end-effector of a 6DOF serial articulated robot. The environment which holds the inner link can be dynamic. Formulations capable of identifying the type of contact between the links and parameters vital for control purposes based on the force and torque data provided by a wrist mounted F/T sensor are established for a generic spatial case. Experimental results indicate that the established methodology …
Assessment Of Spatial Analysis Techniques For Estimating Impervious Cover, Steven Roso, Michael J. Boyd, Laurie A. Chisholm
Assessment Of Spatial Analysis Techniques For Estimating Impervious Cover, Steven Roso, Michael J. Boyd, Laurie A. Chisholm
Faculty of Engineering - Papers (Archive)
Impervious cover proportion is recognised as an important parameter in hydrologic modelling. Recent advances in the spatial sciences provide new capabilities for estimation of this value. This paper describes an assessment of seven estimation techniques, including human and computer based methods requiring a range of different input data and skill levels. In order to quantify the value of any gain in accuracy, the results from each method were applied to a real catchment using event based (WBNM) and continuous simulation (MUSIC) hydrologic models. The results showed that use of high resolution satellite imagery enabled the most accurate measurements of impervious …
A 3-D Microelectrode System For Dielectrophoretic Manipulation Of Microparticles, Dafeng Chen, Hejun Du, Haiqing Gong, Weihua Li
A 3-D Microelectrode System For Dielectrophoretic Manipulation Of Microparticles, Dafeng Chen, Hejun Du, Haiqing Gong, Weihua Li
Faculty of Engineering - Papers (Archive)
This paper presents a microfluidic system for manipulation and separation of micron-sized particles based on the combined use of negative dielectrophoresis (DEP) and hydrodynamic forces. A 3-D microelectrode structure (so called paired electrode array) are constructed face to face on the top and bottom sides of the microchannel and driven with highfrequency AC voltage to generate dielectrophoretic gates. Depending on the relative strengths of the two forces, particles such as polystyrene beads or cells carrying by a laminar flow can either penetrate the gate or settle there. This gives rise to certain applications including selectively concentrating particles from the flow, …
Special Class Of Positive Definite Functions For Formulating Adaptive Micro/Nano Manipulator Control, Hwee Choo Liaw, Denny Oetomo, Gursel Alici, Bijan Shirinzadeh
Special Class Of Positive Definite Functions For Formulating Adaptive Micro/Nano Manipulator Control, Hwee Choo Liaw, Denny Oetomo, Gursel Alici, Bijan Shirinzadeh
Faculty of Engineering - Papers (Archive)
This paper presents a special class of positive definite functions for the formulation of adaptive control strategies, specifically in the research of an effective control algorithm for piezoelectric actuation systems in micro/nano manipulation. To deal with the control problems of unknown system parameters, nonlinear hysteresis effects, and disturbances in the piezoelectric actuation systems, an adaptive control methodology is proposed. Using the saturation function derived from a positive definite function to formulate the control methodology, the closed-loop system stability can be guaranteed. Furthermore, the control methodology is proposed to track a desired motion trajectory in position, velocity, and acceleration. In this …
Chemical Modification Of Precursor Solution For Long Length Ybco Coated Conductor Fabrication, Jaimoo Yoo, Young-Kuk Kim, Kookchae Chung, Jaewoong Ko, Gye-Won Hong, Hee-Gyoun Lee, Jin-Heung Kim, Hyungsik Chung, X. L. Wang, S. X. Dou
Chemical Modification Of Precursor Solution For Long Length Ybco Coated Conductor Fabrication, Jaimoo Yoo, Young-Kuk Kim, Kookchae Chung, Jaewoong Ko, Gye-Won Hong, Hee-Gyoun Lee, Jin-Heung Kim, Hyungsik Chung, X. L. Wang, S. X. Dou
Faculty of Engineering - Papers (Archive)
Long length MOD processing of YBCO conductor requires high performance precursor solution without degradation during the process. In this study, effect of chemical modification of precursor solution on MOD processing was investigated to meet the requirement. Highly stable YBCO precursor solution was synthesized with PVP (polyvinylpyrrolidone) and crack-free thick precursor film was successfully fabricated. However, annealed YBCO film shows porous microstructures originated from large HF gas generation from thick films and residual carbon from additives. Reduction of fluorine content is required to densify microstructures. In order to reduce fluorine content, F-free Cu-precursor solution was synthesized. YBCO film with Jc …
A New Model For Thermal Conductivity In Nanofluids, Pei Tillman, James M. Hill
A New Model For Thermal Conductivity In Nanofluids, Pei Tillman, James M. Hill
Faculty of Engineering - Papers (Archive)
Nanofluids exhibit enhanced thermal conductivity superior to traditional heat transfer fluids. The conventional theoretical models cannot explain the large enhancement of the thermal conductivity of nanofluids. It has been proposed that an interfacial structure formed by liquid molecular layering might play an important role. To date there is no known procedure to properly calculate the nanolayer thickness, and all previous investigators arbitrarily adopt a layer thickness which is consistent with experimental results. Here we investigate the thermal conductivity structure of this interfacial layer and its impact on the effective thermal conductivity and an expression for the thermal conductivity profile in …
Providing A Context For First Year Engineering Students: A Report On Attempts At Course Inversion, Richard A. Dwight, Timothy J. Mccarthy, Anna L. Carew, Brian Ferry
Providing A Context For First Year Engineering Students: A Report On Attempts At Course Inversion, Richard A. Dwight, Timothy J. Mccarthy, Anna L. Carew, Brian Ferry
Faculty of Engineering - Papers (Archive)
Observations of how engineering students approach learning activities in the earlier years of their degree, report that they do not recognise real-life context that links to the theory they are required to apply in learning tasks. This impacts on their motivation and contributes to a lack of transfer of basic knowledge in the latter years of their degree. A new subject for first year engineering students was introduced at the University of Wollongong in 2005 focusing on real-life engineering problems requiring analysis for effective solution. Students are encouraged to explore the use of basic principles and available analysis techniques relevant …