The IKBALS project: multi-modal reasoning in legal knowledge based systems

In attempting to build intelligent litigation support tools, we have moved beyond first generation, production rule legal expert systems. Our work integrates rule based and case based reasoning with intelligent information retrieval. When using the case based reasoning methodology, or in our case the specialisation of case based retrieval, we need to be aware of how to retrieve relevant experience. Our research, in the legal domain, specifies an approach to the retrieval problem which relies heavily on an extended object oriented/rule based system architecture that is supplemented with causal background information. We use a distributed agent architecture to help support the reasoning process of lawyers. Our approach to integrating rule based reasoning, case based reasoning and case based retrieval is contrasted to the CABARET and PROLEXS architectures which rely on a centralised blackboard architecture. We discuss in detail how our various cooperating agents interact, and provide examples of the system at work. The IKBALS system uses a specialised induction algorithm to induce rules from cases. These rules are then used as indices during the case based retrieval process. Because we aim to build legal support tools which can be modified to suit various domains rather than single purpose legal expert systems, we focus on principles behind developing legal knowledge based systems. The original domain chosen was theAccident Compensation Act 1989 (Victoria, Australia), which relates to the provision of benefits for employees injured at work. For various reasons, which are indicated in the paper, we changed our domain to that ofCredit Act 1984 (Victoria, Australia). This Act regulates the provision of loans by financial institutions. The rule based part of our system which provides advice on the Credit Act has been commercially developed in conjunction with a legal firm. We indicate how this work has lead to the development of a methodology for constructing rule based legal knowledge based systems. We explain the process of integrating this existing commercial rule based system with the case base reasoning and retrieval architecture.

Bluetooth and Wi-Fi MAC address based crowd data collection and monitoring : benefits, challenges and enhancement

This paper firstly presents the benefits and critical challenges on the use of Bluetooth and Wi-Fi for crowd data collection and monitoring. The major challenges include antenna characteristics, environment’s complexity and scanning features. Wi-Fi and Bluetooth are compared in this paper in terms of architecture, discovery time, popularity of use and signal strength. Type of antennas used and the environment’s complexity such as trees for outdoor and partitions for indoor spaces highly affect the scanning range. The aforementioned challenges are empirically evaluated by “real” experiments using Bluetooth and Wi-Fi Scanners. The issues related to the antenna characteristics are also highlighted by experimenting with different antenna types. Novel scanning approaches including Overlapped Zones and Single Point Multi-Range detection methods will be then presented and verified by real-world tests. These novel techniques will be applied for location identification of the MAC IDs captured that can extract more information about people movement dynamics.

A sensor fault detection and isolation method in interior permanent-magnet synchronous motor drives based on an extended Kalman filter

Interior permanent-magnet synchronous motors (IPMSMs) become attractive candidates in modern hybrid electric vehicles and industrial applications. Usually, to obtain good control performance, the electric drives of this kind of motor require one position, one dc link, and at least two current sensors. Failure of any of these sensors might lead to degraded system performance or even instability. As such, sensor fault resilient control becomes a very important issue in modern drive systems. This paper proposes a novel sensor fault detection and isolation algorithm based on an extended Kalman filter. It is robust to system random noise and efficient in real-time implementation. Moreover, the proposed algorithm is compact and can detect and isolate all the sensor faults for IPMSM drives. Thorough theoretical analysis is provided, and the effectiveness of the proposed approach is proven by extensive experimental results.

Design methodologies and architectures of hardware-based evolutionary algorithms for aerospace optimisation applications on FPGAS

This thesis is a study of new design methods for allowing evolutionary algorithms to be more effectively utilised in aerospace optimisation applications where computation needs are high and computation platform space may be restrictive. It examines the applicability of special hardware computational platforms known as field programmable gate arrays and shows that with the right implementation methods they can offer significant benefits. This research is a step forward towards the advancement of efficient and highly automated aircraft systems for meeting compact physical constraints in aerospace platforms and providing effective performance speedups over traditional methods.

Biological performance of a polycaprolactone-based scaffold plus recombinant human morphogenetic protein-2 (rhBMP-2) in an ovine thoracic interbody fusion model

PURPOSE. We develop a sheep thoracic spine interbody fusion model to study the suitability of polycaprolactone-based scaffold and recombinant human bone morphogenetic protein-2 (rhBMP-2) as a bone graft substitute within the thoracic spine. The surgical approach is a mini- open thoracotomy with relevance to minimally invasive deformity correction surgery for adolescent idiopathic scoliosis. To date there are no studies examining the use of this biodegradable implant in combination with biologics in a sheep thoracic spine model. METHODS. In the present study, six sheep underwent a 3-level (T6/7, T8/9 and T10/11) discectomy with randomly allocated implantation of a different graft substitute at each of the three levels; (i) calcium phosphate (CaP) coated polycaprolactone-based scaffold plus 0.54μg rhBMP-2, (ii) CaP coated PCL- based scaffold alone or (iii) autograft (mulched rib head). Fusion was assessed at six months post-surgery. RESULTS. Computed Tomographic scanning demonstrated higher fusion grades in the rhBMP-2 plus PCL- based scaffold group in comparison to either PCL-based scaffold alone or autograft. These results were supported by histological evaluations of the respective groups. Biomechanical testing revealed significantly higher stiffness for the rhBMP-2 plus PCL- based scaffold group in all loading directions in comparison to the other two groups. CONCLUSION. The results of this study demonstrate that rhBMP-2 plus PCL- based scaffold is a viable bone graft substitute, providing an optimal environment for thoracic interbody spinal fusion in a large animal model.

Flux density

Social Interiors (Julian Knowles, Rik Rue, Shane Fahey) are currently developing a major sound art project entitled Flux Density, in collaboration with a team of artists, focused on investigating the changing relationships between emerging digital technologies and traditional ‘obsolete’ analogue media. The project has two main components. – a curated compilation and a live performance. It is a large scale curatorial and performance project led by Social Interiors with assistant curators Joel Stern, Alessio Cavallaro and Shannon O’Neill. Presentation - International Symposium of Electronic Art. Social Interiors are one of Australia’s best known experimental sound ensembles. Project will consist of an online compilation of historic music emerging from the 80s cassette culture era, remix based works by Social Interiors, and work from new cassette labels established in a post internet era. Performance project will take place in Sydney and consist of Social Interiors in performance/collaboration with a range of well known artists. Partners include ABC Radio, ISEA, and Extreme Records.

Improvement of a dynamic accumulator at ICICS 07 and its application in multi-user keyword-based retrieval on encrypted data

A dynamic accumulator is an algorithm, which merges a large set of elements into a constant-size value such that for an element accumulated, there is a witness confirming that the element was included into the value, with a property that accumulated elements can be dynamically added and deleted into/from the original set. Recently Wang et al. presented a dynamic accumulator for batch updates at ICICS 2007. However, their construction suffers from two serious problems. We analyze them and propose a way to repair their scheme. We use the accumulator to construct a new scheme for common secure indices with conjunctive keyword-based retrieval.

Structure-controlled, vertical graphene-based, binder-free electrodes from plasma-reformed butter enhance supercapacitor performance

Vertical graphene nanosheets (VGNS) hold great promise for high-performance supercapacitors owing to their excellent electrical transport property, large surface area and in particular, an inherent three-dimensional, open network structure. However, it remains challenging to materialise the VGNS-based supercapacitors due to their poor specific capacitance, high temperature processing, poor binding to electrode support materials, uncontrollable microstructure, and non-cost effective way of fabrication. Here we use a single-step, fast, scalable, and environmentally-benign plasma-enabled method to fabricate VGNS using cheap and spreadable natural fatty precursor butter, and demonstrate the controllability over the degree of graphitization and the density of VGNS edge planes. Our VGNS employed as binder-free supercapacitor electrodes exhibit high specific capacitance up to 230 F g−1 at a scan rate of 10 mV s−1 and >99% capacitance retention after 1,500 charge-discharge cycles at a high current density, when the optimum combination of graphitic structure and edge plane effects is utilised. The energy storage performance can be further enhanced by forming stable hybrid MnO2/VGNS nano-architectures which synergistically combine the advantages from both VGNS and MnO2. This deterministic and plasma-unique way of fabricating VGNS may open a new avenue for producing functional nanomaterials for advanced energy storage devices.

3-Orders-of-magnitude density control of single-walled carbon nanotube networks by maximizing catalyst activation and dosing carbon supply

Tailoring the density of random single-walled carbon nanotube (SWCNT) networks is of paramount importance for various applications, yet it remains a major challenge due to the insufficient catalyst activation in most growth processes. Here we report on a simple and effective method to maximise the number of active catalyst nanoparticles using catalytic chemical vapor deposition (CCVD). By modulating short pulses of acetylene into a methane-based CCVD growth process, the density of SWCNTs is dramatically increased by up to three orders of magnitude without increasing the catalyst density and degrading the nanotube quality. In the framework of a vapor-liquid-solid model, we attribute the enhanced growth to the high dissociation rate of acetylene at high temperatures at the nucleation stage, which can be effective in both supersaturating the larger catalyst nanoparticles and overcoming the nanotube nucleation energy barrier of the smaller catalyst nanoparticles. These results are highly relevant to numerous applications of random SWCNT networks in next-generation energy, sensing and biomedical devices. © 2011 The Royal Society of Chemistry.

Single-step, rapid low-temperature synthesis of Si quantum dots embedded in an amorphous SiC matrix in high-density reactive plasmas

A simple, effective and innovative approach based on low-pressure, thermally nonequilibrium, high-density inductively coupled plasmas is proposed to rapidly synthesize Si quantum dots (QDs) embedded in an amorphous SiC (a-SiC) matrix at a low substrate temperature and without any commonly used hydrogen dilution. The experimental results clearly demonstrate that uniform crystalline Si QDs with a size of 3-4 nm embedded in the silicon-rich (carbon content up to 10.7at.%) a-SiC matrix can be formed from the reactive mixture of silane and methane gases, with high growth rates of ∼1.27-2.34 nm s-1 and at a low substrate temperature of 200 °C. The achievement of the high-rate growth of Si QDs embedded in the a-SiC without any commonly used hydrogen dilution is discussed based on the unique properties of the inductively coupled plasma-based process. This work is particularly important for the development of the all-Si tandem cell-based third generation photovoltaic solar cells.

Temperature-dependent properties of nc-Si thin films synthesized in low-pressure, thermally nonequilibrium, high-density inductively coupled plasmas

Silicon thin films were synthesized simultaneously on single-crystal silicon and glass substrates by lowpressure, thermally nonequilibrium, high-density inductively coupled plasma-assisted chemical vapor deposition from the silane precursor gas without any additional hydrogen dilution in a broad range of substrate temperatures from 100 to 500 °C. The effect of the substrate temperature on the morphological, structural and optical properties of the synthesized silicon thin films is systematically studied by X-ray diffractometry, Raman spectroscopy, UV-vis spectroscopy, and scanning electron microscopy. It is shown that the formation of nanocrystalline silicon (nc-Si) occurs when the substrate temperature is higher than 200 °C and that all the deposited nc-Si films have a preferential growth along the (111) direction. However, the mean grain size of the (111) orientation slightly and gradually decreases while the mean grain size of the (220) orientation shows a monotonous increase with the increased substrate temperature from 200 to 500 °C. It is also found that the crystal volume fraction of the synthesized nc-Si thin films has a maximum value of ∼69.1% at a substrate temperature of 300 rather than 500 °C. This rather unexpected result is interpreted through the interplay of thermokinetic surface diffusion and hydrogen termination effects. Furthermore, we have also shown that with the increased substrate temperature from 100 to 500 °C, the optical bandgap is reduced while the growth rates tend to increase. The maximum rates of change of the optical bandgap and the growth rates occur when the substrate temperature is increased from 400 to 500 °C. These results are highly relevant to the development of photovoltaic thin-film solar cells, thin-film transistors, and flat-panel displays.

Magnetic-field-enhanced synthesis of single-wall carbon nanotubes in arc discharge

The ability to control the properties of single-wall nanotubes (SWNTs) produced in the arc discharge is important for many practical applications. Our experiments suggest that the length of SWNTs significantly increases (up to 4000 nm), along with the purity of the carbon deposit, when the magnetic field is applied to arc discharge. Scanning electron microscopy and transmission electron microscopy analyses have demonstrated that the carbon deposit produced in the magnetic-field-enhanced arc mainly consists of the isolated and bunched SWNTs. A model of a carbon nanotube interaction and growth in the thermal plasma was developed, which considers several important effects such as anode ablation that supplies the carbon plasma in an anodic arc discharge technique, and the momentum, charge, and energy transfer processes between nanotube and plasma. It is shown that the nanotube charge with respect to the plasma as well as nanotube length depend on plasma density and electric field in the interelectrode gap. For instance, nanotube charge changes from negative to positive value with an electron density decrease. The numerical simulations based on the Monte Carlo technique were performed, which explain an increase in the nanotubes produced in the magnetic-field-enhanced arc discharge. © 2008 American Institute of Physics.

p-type doping of ZnO by means of high-density inductively coupled plasmas

A custom-designed inductively coupled plasma assisted radio-frequency magnetron sputtering deposition system has been used to fabricate N-doped p-type ZnO (ZnO:N) thin films on glass substrates from a sintered ZnO target in a reactive Ar + N2 gas mixture. X-ray diffraction and scanning electron microscopy analyses show that the ZnO:N films feature a hexagonal crystal structure with a preferential (002) crystallographic orientation and grow as vertical columnar structures. Hall effect and X-ray photoelectron spectroscopy analyses show that N-doped ZnO thin films are p-type with a hole concentration of 3.32 × 1018 cm- 3 and mobility of 1.31 cm2 V- 1 s- 1. The current-voltage measurement of the two-layer structured ZnO p-n homojunction clearly reveals the rectifying ability of the p-n junction. The achievement of p-type ZnO:N thin films is attributed to the high dissociation ability of the high-density inductively coupled plasma source and effective plasma-surface interactions during the growth process.

Effective control of nanostructured phases in rapid, room-temperature synthesis of nanocrystalline Si in high-density plasmas

An innovative and effective approach based on low-pressure, low-frequency, thermally nonequilibrium, high-density inductively coupled plasmas is proposed to synthesize device-quality nanocrystalline silicon (nc-Si) thin films at room temperature and with very competitive growth rates. The crystallinity and microstructure properties (including crystal structure, crystal volume fraction, surface morphology, etc.) of this nanostructured phase of Si can be effectively tailored in broad ranges for different device applications by simply varying the inductive rf power density from 25.0 to 41.7 mW/cm3. In particular, at a moderate rf power density of 41.7 mW/cm3, the nc-Si films feature a very high growth rate of 2.37 nm/s, a high crystalline fraction of 86%, a vertically aligned columnar structure with the preferential (111) growth orientation and embedded Si quantum dots, as well as a clean, smooth and defect-free interface. We also propose the formation mechanism of nc-Si thin films which relates the high electron density and other unique properties of the inductively coupled plasmas and the formation of the nanocrystalline phase on the Si surface.

Rapid, low-temperature synthesis of nc-Si in high-density, non-equilibrium plasmas : enabling nanocrystallinity at very low hydrogen dilution

Nanocrystalline silicon thin films were deposited on single-crystal silicon and glass substrates simultaneously by inductively coupled plasma-assisted chemical vapor deposition from the reactive silane reactant gas diluted with hydrogen at a substrate temperature of 200 °C. The effect of hydrogen dilution ratio X (X is defined as the flow rate ratio of hydrogen to silane gas), ranging from 1 to 20, on the structural and optical properties of the deposited films, is extensively investigated by Raman spectroscopy, X-ray diffraction, Fourier transform infrared absorption spectroscopy, UV/VIS spectroscopy, and scanning electron microscopy. Our experimental results reveal that, with the increase of the hydrogen dilution ratio X, the deposition rate Rd and hydrogen content CH are reduced while the crystalline fraction Fc, mean grain size δ and optical bandgap ETauc are increased. In comparison with other plasma enhanced chemical vapor deposition methods of nanocrystalline silicon films where a very high hydrogen dilution ratio X is routinely required (e.g. X > 16), we have achieved nanocrystalline silicon films at a very low hydrogen dilution ratio of 1, featuring a high deposition rate of 1.57 nm/s, a high crystalline fraction of 67.1%, a very low hydrogen content of 4.4 at.%, an optical bandgap of 1.89 eV, and an almost vertically aligned columnar structure with a mean grain size of approximately 19 nm. We have also shown that a sufficient amount of atomic hydrogen on the growth surface essential for the formation of nanocrystalline silicon is obtained through highly-effective dissociation of silane and hydrogen molecules in the high-density inductively coupled plasmas. © 2009 The Royal Society of Chemistry.