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Faculty of Engineering and Information Sciences - Papers: Part A

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Full-Text Articles in Social and Behavioral Sciences

A Low Cost Soft Mapper For Turbo Equalization With High Order Modulation, Licai Fang, Qinghua Guo, Defeng (David) Huang, Sven Nordholm Jan 2012

A Low Cost Soft Mapper For Turbo Equalization With High Order Modulation, Licai Fang, Qinghua Guo, Defeng (David) Huang, Sven Nordholm

Faculty of Engineering and Information Sciences - Papers: Part A

In an MMSE based turbo equalization system, a soft mapper calculates the symbol mean and variance based on extrinsic Log-Likelihood-Ratios (LLRs) information coming from a Soft-Input Soft-Output (SISO) decoder. In this paper, we investigate the complexity of this module, and in particular, we employ a 3-segment linear approximation approach to calculate the mean and variance of data symbols from LLRs. For FPGA and VLSI implementation, we propose novel piecewise linear functions which map LLR to the mean and variance directly without the use of any two-variable-input multipliers. Simulation results for 16-QAM and 64-QAM show that the no multiplier approach has ...


Improvements In Dose Calculation Accuracy For Small Off-Axis Targets In High Dose Per Fraction Tomotherapy, Nicholas Hardcastle, Adam Bayliss, Jeannie Wong, Anatoly B. Rosenfeld, Wolfgang A. Tome Jan 2012

Improvements In Dose Calculation Accuracy For Small Off-Axis Targets In High Dose Per Fraction Tomotherapy, Nicholas Hardcastle, Adam Bayliss, Jeannie Wong, Anatoly B. Rosenfeld, Wolfgang A. Tome

Faculty of Engineering and Information Sciences - Papers: Part A

Purpose: A recent field safety notice from TomoTherapy detailed the underdosing of small, off-axis targets when receiving high doses per fraction. This is due to angular undersampling in the dose calculation gantry angles. This study evaluates a correction method to reduce the underdosing, to be implemented in the current version (v4.1) of the TomoTherapy treatment planning software. Methods: The correction method, termed "Super Sampling" involved the tripling of the number of gantry angles from which the dose is calculated during optimization and dose calculation. Radiochromic film was used to measure the dose to small targets at various off-axis distances ...


Thermodynamic Analysis Of A High-Yield Biochemical Process For Biofuel Production, M Imroz Sohel, Michael W. Jack Jan 2012

Thermodynamic Analysis Of A High-Yield Biochemical Process For Biofuel Production, M Imroz Sohel, Michael W. Jack

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a thermodynamic analysis of a high-yield biochemical process for biofuel production from lignocelluosic biomass based on a previously proposed process. Unlike the standard biochemical process, which ferments sugar intermediates to ethanol, the process under consideration converts sugars to acetic acid which is esterified and hydrogenated to produce ethanol. This process has a significantly higher yield and produces no carbon dioxide. However, we find that the thermodynamic efficiency of the process is not increased in proportion to the yield gain. An additional survey of various biofuel production processes showed no direct correlation between yield and thermodynamic efficiency. This ...


Performance Analysis Of Distribution Networks Under High Penetration Of Solar Pv, M J. E Alam, Kashem M. Muttaqi, Darmawan Sutanto, L Elder, A Baitch Jan 2012

Performance Analysis Of Distribution Networks Under High Penetration Of Solar Pv, M J. E Alam, Kashem M. Muttaqi, Darmawan Sutanto, L Elder, A Baitch

Faculty of Engineering and Information Sciences - Papers: Part A

Integration of solar photovoltaic (PV) resources into distribution networks changes the normally expected network behaviour by injecting real power into the point of connection. Depending on the characteristics and setup of the PV inverter, reactive power could also be injected into the network. The impact will depend on the control strategy adopted for reactive power injection. Typically, solar PV units are installed at low voltage (LV) level in distribution networks. Cluster based installation of numerous PV inverters in the LV level will impact the operation of both the host LV network and the upstream medium voltage network. With random variations ...


Acoustic Emission Monitoring Of Split Formation During Charpy Impact Testing Of High Strength Steel, Andrii Kostryzhev, R B. Punch, Claire L. Davis, Martin Strangwood Jan 2012

Acoustic Emission Monitoring Of Split Formation During Charpy Impact Testing Of High Strength Steel, Andrii Kostryzhev, R B. Punch, Claire L. Davis, Martin Strangwood

Faculty of Engineering and Information Sciences - Papers: Part A

Acoustic emission (AE) monitoring has been used to detect split formation during room temperature low blow Charpy impact testing of high strength thick strip steels. The AE signal analysis identified separate signals originating from hammer impact, plastic deformation (verified using Charpy impact testing on mild steel with no splits) and split initiation/growth. The presence of splits was confirmed by sectioning and fractography, and the splits were brittle in nature. A possible correlation between the AE signal features and fracture mode is presented.


Responsiveness Of High Screenings And Commercial Cereal Grains To A Blend Of Xylanase And Phytase Enzyme Products, R J. Hughes, M S. Geier, J L. Black, A M. Tredrea, S Diffey, S G. Nielsen Jan 2011

Responsiveness Of High Screenings And Commercial Cereal Grains To A Blend Of Xylanase And Phytase Enzyme Products, R J. Hughes, M S. Geier, J L. Black, A M. Tredrea, S Diffey, S G. Nielsen

Faculty of Engineering and Information Sciences - Papers: Part A

Two experiments evaluated the apparent metabolisable energy (AME) values for cereal grains fed with and without a blend of xylanase and phytase enzyme products to broiler chickens. The first experiment involved 30 high screenings grains (10 wheats, 11 barleys, 3 triticales, and 6 sorghums). The second experiment involved 50 grains (20 wheats, 13 barleys, 3 triticales and 14 sorghums) donated by commercial companies throughout Australia. Each experiment included "connectivity" grains used in previous experiments that contributed to the AusScan near infrared reflectance (NIR) calibration database. The inclusion of "connectivity" grains (15 in Experiment 1 and 17 in Experiment 2) enabled ...


Research To Establish A Systematic Approach To Safe Welding Procedure Development Using Austenitic Filler Material For Fabrication Of High Strength Steel, Lenka Kuzmikova, John Norrish, Huijun Li, Mark Callaghan Jan 2011

Research To Establish A Systematic Approach To Safe Welding Procedure Development Using Austenitic Filler Material For Fabrication Of High Strength Steel, Lenka Kuzmikova, John Norrish, Huijun Li, Mark Callaghan

Faculty of Engineering and Information Sciences - Papers: Part A

High strength, thermo-mechanically treated steels often require very careful control of welding procedures to ensure freedom from hydrogen assisted cold cracking (HACC) in the weld metal and heat affected zone (HAZ) whilst avoiding undue loss of heat affected zone strength. In practice this leads to restricted operating envelopes and the requirement for rigorous procedure management. An alternative approach is the use of austenitic welding consumables but whilst this may be expected to expand the process parameter envelope its use is often restricted by adherence to procedures previously developed for ferritic consumables. The current paper describes the research undertaken to establish ...


Can Australia High Speed Rail Overcome It's Bumpy History?, Philip Laird Jan 2011

Can Australia High Speed Rail Overcome It's Bumpy History?, Philip Laird

Faculty of Engineering and Information Sciences - Papers: Part A

The Australian Government has released an "implementation" study for high speed rail (or HSR) on the east coast with a further study to follow. The proposal looks at corridors between Melbourne, Sydney and Brisbane. It includes the option of three-hour travel times between Sydney and Melbourne, with tickets costing around $100. With the projected price of the project starting at around $60 billion, and Australia's chequered history with HSR, it is not unreasonable to ask whether the project will commence. In this case, would Sydney to Newcastle take preference over Sydney to Melbourne?


High-Energy, Picosecond, Cryogenic Yb:Yag Chirped-Pulse Amplifier At Khz Repetition Rates For Opcpa Pumping, Kyung-Han Hong, Juliet Gopinath, Darren Rand, Aleem M. Siddiqui, Shu-Wei Huang, Enbang Li, Benjamin J. Eggleton, John D. Hybl, Tso Yee Fan, Franz X. Kartner Jan 2010

High-Energy, Picosecond, Cryogenic Yb:Yag Chirped-Pulse Amplifier At Khz Repetition Rates For Opcpa Pumping, Kyung-Han Hong, Juliet Gopinath, Darren Rand, Aleem M. Siddiqui, Shu-Wei Huang, Enbang Li, Benjamin J. Eggleton, John D. Hybl, Tso Yee Fan, Franz X. Kartner

Faculty of Engineering and Information Sciences - Papers: Part A

We report on the development of a 50-mJ-class ~10-ps chirped-pulse amplifier at kHz repetition rates using cryogenic Yb:YAG regenerative and multi-pass amplifiers. The system is well suited as pump laser for kHz high-average-power ultra-broadband OPCPAs. '2010 Optical Society of America


Investigation Of High Resolution Compact Gamma Camera Module Based On A Continuous Scintillation Crystal Using A Novel Charge Division Readout Method, Qiu-Sheng Dai, Cui-Lan Zhao, Hualin Zhang, Yujin Qi Jan 2010

Investigation Of High Resolution Compact Gamma Camera Module Based On A Continuous Scintillation Crystal Using A Novel Charge Division Readout Method, Qiu-Sheng Dai, Cui-Lan Zhao, Hualin Zhang, Yujin Qi

Faculty of Engineering and Information Sciences - Papers: Part A

The objective of this study is to investigate a high performance and lower cost compact gamma camera module for a multi-head small animal SPECT system. A compact camera module was developed using a thin Lutetium Oxyorthosilicate (LSO) scintillation crystal slice coupled to a Hamamatsu H8500 position sensitive photomultiplier tube (PSPMT). A two-stage charge division readout board based on a novel sub-tractive resistive readout with a truncated center-of-gravity (TCOG) positioning method was developed for the camera. The performance of the camera was evaluated using a flood 99mTc source with a four-quadrant bar-mask phantom. The preliminary experimental results show that the image ...


High-Energy, Khz-Repetition-Rate, Ps Cryogenic Yb:Yag Chirped-Pulse Amplifier, Kyung-Han Hong, Juliet Gopinath, Darren Rand, Aleem M. Siddiqui, Shu-Wei Huang, Enbang Li, Benjamin J. Eggleton, John D. Hybl, Tso Yee Fan, Franz X. Kartner Jan 2010

High-Energy, Khz-Repetition-Rate, Ps Cryogenic Yb:Yag Chirped-Pulse Amplifier, Kyung-Han Hong, Juliet Gopinath, Darren Rand, Aleem M. Siddiqui, Shu-Wei Huang, Enbang Li, Benjamin J. Eggleton, John D. Hybl, Tso Yee Fan, Franz X. Kartner

Faculty of Engineering and Information Sciences - Papers: Part A

We demonstrate amplification of picosecond laser pulses to 40 mJ at a 2 kHz pulse repetition frequency (PRF) from a two-stage cryogenic chirped-pulse Yb:YAG amplifier, composed of a regenerative amplifier (RGA) and a two-pass booster amplifier. The RGA produces 8.2 mJ of energy at 2 kHz PRF and 13.2 mJ at 1 kHz PRF with excellent energy stability (~0.3% rms) and beam quality ( M2<1.1 ). Pulse stretching and compression are achieved by using a chirped fiber Bragg grating and a multilayer dielectric grating pair, respectively. Compressed 15 ps pulses from the RGA are obtained with a throughput efficiency of ~80% (~6.5 mJ for 2 kHz ). The booster amplifier further amplifies the pulses to 40 mJ at 2 kHz PRF, and ~32 mJ, ~15 ps pulses are expected after compression. The amplifier chain seeded from a femtosecond Yb-fiber laser enables the optical self-synchronization between signal and pump in optical parametric chirped-pulse amplifier applications.


High Spatial Resolution Fibre -Optic Fizeau Interferometric Strain Sensor Based On An In-Fiber Spherical Microcavity, Enbang Li, Gang-Ding Peng, Xin Ding Jan 2008

High Spatial Resolution Fibre -Optic Fizeau Interferometric Strain Sensor Based On An In-Fiber Spherical Microcavity, Enbang Li, Gang-Ding Peng, Xin Ding

Faculty of Engineering and Information Sciences - Papers: Part A

We present a fiber-optic Fizeau interferometric strain sensor consisting of an in-fiber spherical microcavity of 39um in diameter. The spherical microcavity was formed by splicing a normal single-mode fiber with a hollow-core photonic crystal fiber. We demonstrate that strain sensing can be realized by using the interference between the light signals reflected by the front and rear surfaces of the sphere. Experiments have shown that the strain sensor has a strain sensitivity of 3.36um/ue and a temperature sensitivity of 1.35um/°C.


Development Of Hydraulic Fracturing In High Stress Conditions In Australian Underground Coal Mines, Dennis John Black, Naj Aziz Jan 2008

Development Of Hydraulic Fracturing In High Stress Conditions In Australian Underground Coal Mines, Dennis John Black, Naj Aziz

Faculty of Engineering and Information Sciences - Papers: Part A

Hydraulic fracturing has been used extensively in the petroleum and coalbed methane industries as a means of improving access to the reservoir and thereby enhancing production. In the Australian coal mining industry there has been an aversion to the use of hydraulic fracturing. One of the main reasons for the lack of application of this technology has been the perceived risk of damage to the strata and the resulting impact on future mining operations. A number of Australian mines are progressing toward areas where gas drainage is becoming increasingly difficult and these mines are seriously considering the use of hydraulic ...


Performance Comparison Of Subtractive Resistive Readout With Conventional Resistive Readout For A High-Resolution Compact Gamma Camera, Y J. Qi, M J. Zhang, C L. Zhao, R F. Wojcik Jan 2007

Performance Comparison Of Subtractive Resistive Readout With Conventional Resistive Readout For A High-Resolution Compact Gamma Camera, Y J. Qi, M J. Zhang, C L. Zhao, R F. Wojcik

Faculty of Engineering and Information Sciences - Papers: Part A

The purpose of this study was to investigate an optimal readout for a high-resolution compact gamma camera with maximum performance in crystal element identifications. The compact camera is based on a pixellated Nal(Tl) crystal with 1.2 mm pixel size coupled to a 5" Hamamatsu R3292 PSPMT. A conventional resistive-chain readout was initially developed for the camera. Then a novel subtractive resistive readout developed was utilized to optimize the performance of the camera. The performance of the camera was evaluated by raw flood images of a 137Cs source. The results show that the conventional resistive readout results in a ...


Development And Characterization Of A High-Resolution Microspect System For Small-Animal Imaging, Yujin Qi, Benjamin Tsui, Yuchuan Wang, Brian Yoder, R Wojcik, S Majewski, A G Weisenberger Jan 2005

Development And Characterization Of A High-Resolution Microspect System For Small-Animal Imaging, Yujin Qi, Benjamin Tsui, Yuchuan Wang, Brian Yoder, R Wojcik, S Majewski, A G Weisenberger

Faculty of Engineering and Information Sciences - Papers: Part A

We developed a high-resolution microSPECT system and investigated its performance characteristics for small animal imaging. The microSPECT system consists of a stationary compact gamma camera with interchangeable pinhole and parallel-hole collimators and vertical object rotation mechanism. The modular camera is based on a pixellated NaI(Tl) crystal array with 1.2 mm pixel size and 1.4 mm pixel pitch coupled to a 5” diameter Hamamatsu R3292 PSPMT. The pinhole collimator has a 10cm focal length fitted with keel-edge pinhole apertures with diameters of 1.0, 1.5 and 2.0 mm. The system performance was characterized by the measurements ...


Glass Formation In A (Ti,Zr,Hf)-(Cu,Ni,Ag)-Al High-Order Alloy System By Mechanical Alloying, L C. Zhang, Z Q. Shen, Jian Xu Jan 2003

Glass Formation In A (Ti,Zr,Hf)-(Cu,Ni,Ag)-Al High-Order Alloy System By Mechanical Alloying, L C. Zhang, Z Q. Shen, Jian Xu

Faculty of Engineering and Information Sciences - Papers: Part A

In this work, glass formation under high-energy ball milling was investigated for a (Ti0.33Zr0.33Hf0.33)50(Ni0.33Cu0.33Ag0.33)40Al10 high-order alloy system with equiatomic substitution for early and late transition-metal contents. For comparison, an amorphous alloy ribbon with the same composition was prepared using the melt-spinning method as well. Structural features of the samples were characterized using x-ray diffraction, transmission electron microscopy, and differential scanning calorimetry. Mechanical alloying resulted in a glassy alloy similar to that obtained by melt spinning. However, the glass formation ...


High-Resolution Hi Observations Of The Western Magellanic Bridge, E Muller, L Staveley-Smith, William Zealey, S Stanimirovic Jan 2003

High-Resolution Hi Observations Of The Western Magellanic Bridge, E Muller, L Staveley-Smith, William Zealey, S Stanimirovic

Faculty of Engineering and Information Sciences - Papers: Part A

The 21-cm line emission from a 7 × 6 deg2 region east of and adjoining the Small Magellanic Cloud (SMC) has been observed with the Australia Telescope Compact Array and the Parkes telescopes. This region represents the westernmost part of the Magellanic Bridge, a gas-rich tail extending ∼14° to the Large Magellanic Cloud. A rich and complex neutral hydrogen (H i) structure containing shells, bubbles and filaments is revealed. On the larger scale, the H i of the Bridge is organized into two velocity components. This bimodality, which appears to originate in the SMC, converges to a single velocity component ...