Engineering electrodeposited ZnO films and their memristive switching performance

We report the influence of zinc oxide (ZnO) seed layers on the performance of ZnO-based memristive devices fabricated using an electrodeposition approach. The memristive element is based on a sandwich structure using Ag and Pt electrodes. The ZnO seed layer is employed to tune the morphology of the electrodeposited ZnO films in order to increase the grain boundary density as well as construct highly ordered arrangements of grain boundaries. Additionally, the seed layer also assists in optimizing the concentration of oxygen vacancies in the films. The fabricated devices exhibit memristive switching behaviour with symmetrical and asymmetrical hysteresis loops in the absence and presence of ZnO seed layers, respectively. A modest concentration of oxygen vacancy in electrodeposited ZnO films as well as an increase in the ordered arrangement of grain boundaries leads to higher switching ratios in Ag/ZnO/Pt devices.

Breaking the code of silence : the Wood Royal Commission into New South Wales police : a brief overview

The three-volume Final Report of the Wood inquiry into NSW Police (Royal Commission Into the New South Wales Police Service, 'Final Report, Vol I: Corruption; Vol II: Reform; Vol III: Appendices', May 1997) was publicly released on 15 May 1997, to much media fanfare. The Sydney Morning Herald (SMH) devoted an 8-page special report on I May to the pending release of the Inquiry Report, headed The Police Purge. On the day of the public release of the Report, the SMH five-page 'Special Report' under the banner The Police Verdict was headlined Wood, Carr Split on Drugs. The Australian led with Call for Drug Law Revamp, Force Overhaul to Fight Corruption, Wood Attacks Culture of Greed, and the Daily Telegraph front page 'Final Verdict' was True Blue Strategy for an Honest Police Force...

Voltage unbalance reduction in low voltage feeders by dynamic switching of residential customers among three phases

Low voltage distribution feeders with large numbers of single phase residential loads experience severe current unbalance that often causes voltage unbalance problems. The addition of intermittent generation and new loads in the form of roof top photovoltaic generation and electric vehicles makes these problems even more acute. In this paper, an intelligent dynamic residential load transfer scheme is proposed. Residential loads can be transferred from one phase to another phase to minimize the voltage unbalance along the feeder. Each house is supplied through a static transfer switch with three-phase input and single-phase output connection. The main controller, installed at the transformer will observe the power consumption in each load and determine which house(s) should be transferred from one phase to another in order to keep the voltage unbalance in the feeder at a minimum. The efficacy of the proposed load transfer scheme is verified through MATLAB and PSCAD/EMTDC simulations.

Smart Inter-Phase Switching of Residential Loads in Low Voltage Distribution Feeders

In order to dynamically reduce voltage unbalance along a low voltage distribution feeder, a smart residential load transfer system is discussed. In this scheme, residential loads can be transferred from one phase to another to minimize the voltage unbalance along the feeder. Each house is supplied through a static transfer switch and a controller. The master controller, installed at the transformer, observes the power consumption in each house and will determine which house(s) should be transferred from an initially connected phase to another in order to keep the voltage unbalance minimum. The performance of the smart load transfer scheme is demonstrated by simulations.

Switching radical stability by pH-induced orbital conversion

In most radicals the singly occupied molecular orbital (SOMO) is the highest-energy occupied molecular orbital (HOMO); however, in a small number of reported compounds this is not the case. In the present work we expand significantly the scope of this phenomenon, known as SOMO-HOMO energy-level conversion, by showing that it occurs in virtually any distonic radical anion that contains a sufficiently stabilized radical (aminoxyl, peroxyl, aminyl) non-pi-conjugated with a negative charge (carboxylate, phosphate, sulfate). Moreover, regular orbital order is restored on protonation of the anionic fragment, and hence the orbital configuration can be switched by pH. Most importantly, our theoretical and experimental results reveal a dramatically higher radical stability and proton acidity of such distonic radical anions. Changing radical stability by 3-4 orders of magnitude using pH-induced orbital conversion opens a variety of attractive industrial applications, including pH-switchable nitroxide-mediated polymerization, and it might be exploited in nature.

Source code watermarking based on function dependency oriented sequencing

In the current market, extensive software development is taking place and the software industry is thriving. Major software giants have stated source code theft as a major threat to revenues. By inserting an identity-establishing watermark in the source code, a company can prove it's ownership over the source code. In this paper, we propose a watermarking scheme for C/C++ source codes by exploiting the language restrictions. If a function calls another function, the latter needs to be defined in the code before the former, unless one uses function pre-declarations. We embed the watermark in the code by imposing an ordering on the mutually independent functions by introducing bogus dependency. Removal of dependency by the attacker to erase the watermark requires extensive manual intervention thereby making the attack infeasible. The scheme is also secure against subtractive and additive attacks. Using our watermarking scheme, an n-bit watermark can be embedded in a program having n independent functions. The scheme is implemented on several sample codes and performance changes are analyzed.

Written in code : diversity and the new genetics

Modern genetic research holds out the promise of a bold new future in which humanity has identified and conquered the genetic roots of many diseases. Genetic science also promises to shed light on who we are, what it is that makes us tick, what it is that makes us the way we are — in short, what it is that makes us human. Yet while genetics are a potential saviour (saving us from disease), it also appears as a threat that at the extremes appears to be the stuff of our worst nightmares, such as the prospect, probably more imagined than real, of rows of cloned individuals. The new genetics hold out the promise that through genetics we will be able to determine what we are, a promise that is simultaneously appealing and terrifying. This chapter discusses the cloning of people and parts, the law’s response to cloning, genetics and diversity, a framework for law reform.

Where is the software? Building a Metadata Repository for Software and Code Generated by QUT Researchers

QUT Software Finder is a searchable repository of metadata describing software and source code, which has been created as a result of QUT research activities. It was launched in December 2013. https://researchdatafinder.qut.edu.au/scf The registry was designed to aid the discovery and visibility of QUT research outputs and encourage sharing and re-use of code and software throughout the research community, both nationally and internationally. The repository platform used is VIVO (an open source product initially developed at Cornell University). QUT Software Finder records that describe software or code are connected to information about researchers involved, the research groups, related publications and related projects. Links to where the software or code can be accessed from are also provided alongside licencing and re-use information.

Universal codes from switching strategies

We discuss algorithms for combining sequential prediction strategies, a task which can be viewed as a natural generalisation of the concept of universal coding. We describe a graphical language based on Hidden Markov Models for defining prediction strategies, and we provide both existing and new models as examples. The models include efficient, parameterless models for switching between the input strategies over time, including a model for the case where switches tend to occur in clusters, and finally a new model for the scenario where the prediction strategies have a known relationship, and where jumps are typically between strongly related ones. This last model is relevant for coding time series data where parameter drift is expected. As theoretical contributions we introduce an interpolation construction that is useful in the development and analysis of new algorithms, and we establish a new sophisticated lemma for analysing the individual sequence regret of parameterised models.

Dual Z-source inverter with three-level reduced common mode switching

This paper presents the design of a dual Z-source inverter that can be used with either a single dc source or two isolated dc sources. Unlike traditional inverters, the integration of a properly designed Z-source network and semiconductor switches to the proposed dual inverter allows buck-boost power conversion to be performed over a wide modulation range with three-level output waveforms generated. The connection of an additional transformer to the inverter ac output also allows all generic wye- or delta-connected loads with three-wire or four-wire configuration to be supplied by the inverter. Modulation-wise, the dual inverter can be controlled using a carefully designed carrier-based pulse-width modulation (PWM) scheme that always will ensure balanced voltage boosting of the Z-source network, while simultaneously achieving reduced common-mode switching. Because of the omission of dead-time delays in the dual inverter PWM scheme, its switched common-mode voltage can be completely eliminated, unlike in traditional inverters where narrow common-mode spikes are still generated. Under semiconductor failure conditions, the presented PWM schemes can easily be modified to allow the inverter to operate without interruption and for cases where two isolated sources are used, zero common-mode voltage can still be ensured. These theoretical findings together with the inverter practicality have been confirmed both in simulations using PSIM with Matlab/Simulink coupler and experimentally using a laboratory implemented inverter prototype.

Dual Z-source inverter with three-level reduced common-mode switching

This paper presents the design of a dual Z-source inverter that can be used with either a single dc source or two isolated dc sources. Unlike traditional inverters, the integration of a properly designed Z-source network and semiconductor switches to the proposed dual inverter allows buck-boost power conversion to be performed over a wide modulation range, with three-level output waveforms generated. The connection of an additional transformer to the inverter ac output also allows all generic wye-or delta-connected loads with three-wire or four-wire configuration to be supplied by the inverter. Modulationwise, the dual inverter can be controlled using a carefully designed carrier-based pulsewidth-modulation (PWM) scheme that will always ensure balanced voltage boosting of the Z-source network while simultaneously achieving reduced common-mode switching. Because of the omission of dead-time delays in the dual-inverter PWM scheme, its switched common-mode voltage can be completely eliminated, unlike in traditional inverters, where narrow common-mode spikes are still generated. Under semiconductor failure conditions, the presented PWM schemes can easily be modified to allow the inverter to operate without interruption, and for cases where two isolated sources are used, zero common-mode voltage can still be ensured. These theoretical findings, together with the inverter practicality, have been confirmed in simulations both using PSIM with Matlab/Simulink coupler and experimentally using a laboratory-implemented inverter prototype.

Computational fluid dynamics simulation and turbomachinery code validation of a high pressure ratio radial-inflow turbine

The present study explores reproducing the closest geometry of a high pressure ratio single stage radial-inflow turbine applied in the Sundstrans Power Systems T-100 Multipurpose Small Power Unit. The commercial software ANSYS-Vista RTD along with a built in module, BladeGen, is used to conduct a meanline design and create 3D geometry of one flow passage. Carefully examining the proposed design against the geometrical and experimental data, ANSYS-TurboGrid is applied to generate computational mesh. CFD simulations are performed with ANSYS-CFX in which three-dimensional Reynolds-Averaged Navier-Stokes equations are solved subject to appropriate boundary conditions. Results are compared with numerical and experimental data published in the literature in order to generate the exact geometry of the existing turbine and validate the numerical results against the experimental ones.

Optimized switching control strategy for current-fed half-bridge converter

A switching control strategy is proposed for current-fed half-bridge converters. An active switch based voltage doubler circuit at the secondary side of the isolation transformer is used to obtain zero-current-switching at turn-off and zero-voltage-switching at turn-on in the primary side switches of the current-fed half-bridge converter. The operation of the current-fed half-bridge converter with the proposed switching control strategy is explained using the equivalent circuit during each sub-interval of operation. The operation of the current-fed halfbridge converter is simulated using MATLAB/Simpower and PSIM to verify the feasibility of the switching control strategy. Experimental results are provided to validate the converter's operation.