Modeling and simulation for large scale production systems

Computer modeling and simulation provide a foundation upon which industrial processes and systems can be transformed and innovation dramatically accelerated. Computer modeling and simulation is also an indispensable tool of the information age, used extensively in design, analysis, operations, decision-making, optimization, and education and training. Manufacturing, production and design relies upon simulation to develop efficient production systems and factories that produce quality products. Simulation in industry has yet to meet its full potential. The development of models is very time consuming, particularly for geometries of complex engineering systems such as manufacturing plants, automobiles, aircraft and ships. Computer simulation allows scientists and engineers to understand and predict three-dimensional and time-dependent phenomena in science and engineering discipline. This talk will focus on challenges associated with modeling and simulation in the manufacturing sector and through a number of case studies highlight the benefits gained through the use of such technologies.

Large-scale electrospinning of polymer nanofibers using needleless nozzle

In this study, we have demonstrated that a rotating metal wire coil can be used as a nozzle to electrospin nanofibers on a large-scale. Without using any needles, the rotating wire coil, partially immersed in a polymer solution reservoir, can pick up a thin layer of charged polymer solution and generate a large number of nanofibers from the wire surface simultaneously. This arrangement significantly increases the nanofiber productivity. The fiber productivity was found to be determined by the coil dimensions, applied voltage and polymer concentration. The dependency of fiber diameter on the polymer concentration showed a similar trend to that for a conventional electrospinning system using a syringe needle nozzle, but the coil electrospun fibers were thinner with narrower diameter distribution. The profiles of electric field strength in the coil electrospinning was calculated and showed concentrated electric field intensity on the wire surface.

Proposal of a tiered conceptual framework for sustainable design and planning of large-scale development projects in the metropolitan context

The overwhelming threat posed by climate change means that increasingly, emphasis is being placed on the need to integrate sustainability considerations into all areas of policy making, planning and development. Actors in the built environment are progressively considering environmental and social issues alongside functional and economic aspects of development projects. However, to date in Australia and internationally, there have been few practical examples of integrated applications of sustainability principles in the built environment across design, planning, construction, operation and de-construction phases. Notable initiatives have tended to be narrow in scope, focusing on either mitigation or adaptation strategies. Integrated considerations of impacts from component and building scales to city and regional scales and across physical and socio-economic dimensions are urgently needed, particularly for long-life major infrastructure projects. This paper proposes a conceptual framework based on the principal that early intervention is the most cost-effective and efficient means of implementing effective strategies for mitigation and adaptation. A Strategic Environmental Assessment (SEA) approach is forwarded as an umbrella analytical framework, assembled from analytical methods which are strategically ‘tiered’ to inform different stages of the planning and decision-making process. Techniques such as Ecological footprint, Life cycle costing and Risk analysis may be applied to integrate sustainable design, construction and planning considerations which address both mitigation and adaptation dimensions, results of each analysis ultimately being collated into the overall SEA. This integrated conceptual framework for sustainable, resilient and cost-effective infrastructure development will in practice be applied to assess selected case-studies of major development projects in Australia, focusing on the area of stadium development. Practically applied and timed accordingly, the framework would allow assessments to be targeted towards appropriate decision making levels and enable better decision-making and more efficient resource allocation for major infrastructure development projects.

Life! in Australia : translating prevention research into a large-scale intervention

The increasing prevalence of type 2 diabetes is of great public health concern. In the state of Victoria, Australia, a group-based lifestyle intervention programme, Life! – Taking Action on Diabetes, was developed for people over the age of 50 years who are at high risk of diabetes. It aims to reduce the risk of diabetes by providing practical skills, including goal setting and problem solving, to encourage participants to adopt a healthy diet and active lifestyle. The programme is delivered by specially trained facilitators who have undergone an accredited three-stage training programme. A quality assurance process is also in place to ensure that it is delivered to a consistently high standard. The Life! program
is a direct progression from the Finnish randomised controlled trial and the Greater Green Triangle Diabetes Prevention Project implementation trial. This paper describes how a diabetes prevention programme was implemented at a state-wide level and the training of facilitators to conduct the group sessions. Future studies are needed to examine the cost effectiveness and development of specific programmes for diverse population groups.

Large-scale mechanical peeling of boron nitride nanosheets by low-energy ball milling

Mechanical cleavage by Scotch tape was the first method to produce graphene and is still widely used in laboratories. However, a critical problem of this method is the extremely low yield. We have tailored ball milling conditions to produce gentle shear forces that produce high quality boron nitride (BN) nanosheets in high yield and efficiency. The in-plane structure of the BN nanosheets has not been damaged as shown by near edge X-ray absorption fine structure measurements. The benzyl benzoate acts as the milling agent to reduce the ball impacts and milling contamination. This method is applicable to any layered materials for producing nanosheets.

CAFS : a novel lightweight cache-based scheme for large-scale intrusion alert fusion

In this paper, we present some practical experiences on implementing an alert fusion mechanism from our project. After investigation on most of the existing alert fusion systems, we found the current body of work alternatively weighed down in the mire of insecure design or rarely deployed because of their complexity. As confirmed by our experimental analysis, unsuitable mechanisms could easily be submerged by an abundance of useless alerts. Even with the use of methods that achieve a high fusion rate and low false positives, attack is also possible. To find the solution, we carried out analysis on a series of alerts generated by well-known datasets as well as realistic alerts from the Australian Honey-Pot. One important finding is that one alert has more than an 85% chance of being fused in the following five alerts. Of particular importance is our design of a novel lightweight Cache-based Alert Fusion Scheme, called CAFS. CAFS has the capacity to not only reduce the quantity of useless alerts generated by intrusion detection system, but also enhance the accuracy of alerts, therefore greatly reducing the cost of fusion processing. We also present reasonable and practical specifications for the target-oriented fusion policy that provides a quality guarantee on alert fusion, and as a result seamlessly satisfies the process of successive correlation. Our experiments compared CAFS with traditional centralized fusion. The results showed that the CAFS easily attained the desired level of simple, counter-escapable alert fusion design. Furthermore, as a lightweight scheme, CAFS can easily be deployed and excel in a large amount of alert fusions, which go towards improving the usability of system resources. To the best of our knowledge, our work is a practical exploration in addressing problems from the academic point of view. Copyright © 2011 John Wiley & Sons, Ltd.

Defending against large-scale and coordinated attacks in the ubiquitous environments

Ubiquitous computing is an exciting paradigm shift where technology becomes virtually invisible in our lives. In the increasingly interconnected world, threats to our daily lives can come from unexpected sources and universal directions. Criminals and terrorists have recognized the value of leveraging the ubiquitous computing environments to facilitate the commission of crimes. The cyber criminals typically launch different forms of large-scale and coordinated attacks, causing huge financial loss and potential life hazard. In this talk, we report two innovative approaches to defend against large-scale and coordinated attacks in the ubiquitous environments: 1) Inferring the cyber crime's intent through network traffic classification to enable the early warning of potential attacks, and 2) Profiling the large-scale and coordinated cyber attacks through both microscopic and macroscopic modeling to provide better control of such attacks. These approaches are effective in finding weak symptoms caused by the attacks thus can successfully defend against the large-scale and coordinated attacks at their early stages.

Fine-scale effects of habitat loss and fragmentation despite large-scale gene flow for some regionally declining woodland bird species

Habitat loss and associated fragmentation effects are well-recognised threats to biodiversity. Loss of functional connectivity (mobility, gene flow and demographic continuity) could result in population decline in altered habitat, because smaller, isolated populations are more vulnerable to extinction. We tested whether substantial habitat reduction plus fragmentation is associated with reduced gene flow in three 'decliner' woodland-dependent bird species (eastern yellow robin, weebill and spotted pardalote) identified in earlier work to have declined disproportionately in heavily fragmented landscapes in the Box-Ironbark forest region in north-central Victoria, Australia. For these three decliners, and one 'tolerant' species (striated pardalote), we compared patterns of genetic diversity, relatedness, effective population size, sex-ratios and genic (allele frequency) differentiation among landscapes of different total tree cover, identified population subdivision at the regional scale, and explored fine-scale genotypic (individual-based genetic signature) structure. Unexpectedly high genetic connectivity across the study region was detected for 'decliner' and 'tolerant' species. Power analysis simulations suggest that moderate reductions in gene flow should have been detectable. However, there was evidence of local negative effects of reduced habitat extent and structural connectivity: slightly lower effective population sizes, lower genetic diversity, higher within-site relatedness and altered sex-ratios (for weebill and eastern yellow robin) in 10 x 10 km 'landscapes' with low vegetation cover. We conclude that reduced structural connectivity in the Box-Ironbark ecosystem may still allow sufficient gene flow to avoid the harmful effects of inbreeding in our study species. Although there may still be negative consequences of fragmentation for demographic connectivity, the high genetic connectivity of mobile bird species in this system suggests that reconnecting isolated habitat patches may be less important than increasing habitat extent and/or quality if these need to be traded off.