Fuzzy concepts and formal methods

It has been recognised that formal methods are useful as a modelling tool in requirements engineering. Specification languages such as Z permit the precise and unambiguous modelling of system properties and behaviour. However some system problems, particularly those drawn from the information systems problem domain, may be difficult to model in crisp or precise terms. It may also be desirable that formal modelling should commence as early as possible, even when our understanding of parts of the problem domain is only approximate. This thesis suggests fuzzy set theory as a possible representation scheme for this imprecision or approximation. A fuzzy logic toolkit that defines the operators, measures and modifiers necessary for the manipulation of fuzzy sets and relations is developed. The toolkit contains a detailed set of laws that demonstrate the properties of the definitions when applied to partial set membership. It also provides a set of laws that establishes an isomorphism between the toolkit notation and that of conventional Z when applied to boolean sets and relations. The thesis also illustrates how the fuzzy logic toolkit can be applied in the problem domains of interest. Several examples are presented and discussed including the representation of imprecise concepts as fuzzy sets and relations, system requirements as a series of linguistically quantified propositions, the modelling of conflict and agreement in terms of fuzzy sets and the partial specification of a fuzzy expert system. The thesis concludes with a consideration of potential areas for future research arising from the work presented here.

Counterfactual thinking and anticipated emotions enhance performance in computer skills training

The present study examined the relationship between novice learners’ counterfactual thinking (i.e. generating ‘what if’ and ‘if only’ thoughts) about their initial training experience with a computer application and subsequent improvement in task performance. The role of anticipated emotions towards goal attainment in task performance was also assessed. Undergraduate students (N ¼ 42) with minimal experience in using computer spreadsheets underwent basic training in using Microsoft Excel. All participants were assessed on their anticipated positive and negative emotions regarding goal attainment at the outset. After completing their first task, participants allocated to a counterfactual condition received instructions to generate counterfactual thoughts regarding their initial task performance, whereas participants in a control condition did not. The counterfactual group showed only marginally greater improvement in task performance (measured by task completion time and accuracy) than the control group.  However, we also found that positive anticipated emotions were associated with improvement in task performance but for the counterfactual group only. Our data have implications for incorporating counterfactual thinking into information technology skills training to enhance learning outcomes for novice learners.

Shifting practices and frames: literacy, learning and computer games

Digital culture and the online world have profound implications for contemporary notions of literacy, learning and curriculum. The increasing integration of digital culture and technologies into young people’s lives reflects the energy and excitement offered by online worlds. Online forms of text and communication are shaping students’ experience of the world, including expectations and experiences about learning and literacy. While print literacies remain important, for schools to prepare students to participate in critical and agential ways in the contemporary and future world, they need also to teach them to be fully literate in digital and multimodal literacies, and at ease and in control in the online world. Computer games, and other forms of digital games, teach and exemplify multimodal forms of literacy. Schools can capitalize on their potential and work with them productively. Doing so however, entails recognizing the messy complexity of schooling, and the practicalities of classroom lives. This chapter reports on a three year project in five schools concerned with literacy and computer games, and discusses the important role of teachers as on-the- ground leaders in pioneering new conceptions of literacy, and of curriculum change, and the importance of school structures and support to enable such change to happen.

Teachers and computers for secondary mathematics

In the first stage of a three-year study in which the effects of using computers for the teaching and learning of mathematics are being explored, a questionnaire was developed and administered to teachers of students in grades 7–10 in a representative sample of co-educational post-primary schools in Victoria, Australia. Using open and closed response formats, the information sought included data on the teachers' professional backgrounds, computer ownership and use, and their beliefs and practices in using computers for the teaching of mathematics. In this article, findings related to ownership, professional development, perceptions of technological skills, beliefs about the efficacy of computer use in mathematics, and data on how teachers are using computers for teaching secondary mathematics are presented and discussed.

A comparative study at the logical level of centralised and distributed recovery in clusters

Cluster systems are becoming more prevalent in today’s computer society and users are beginning to request that these systems be reliable. Currently, most clusters have been designed to provide high performance at the cost of providing little to no reliability. To combat this, this report looks at how a recovery facility, based on either a centralised or distributed approach could be implemented into a cluster that is supported by a check pointing facility. This recovery facility can then recover failed user processes by using checkpoints of the processes that have been taken during failure free execution.

Penetration testing professional ethics : a conceptual model and taxonomy

In an environment where commercial software is continually patched to correct security flaws, penetration testing can provide organisations with a realistic assessment of their security posture. Penetration testing uses the same principles as criminal hackers to penetrate corporate networks and thereby verify the presence of software vulnerabilities. Network administrators can use the results of a penetration test to correct flaws and improve overall security. The use of hacking techniques, however, raises several ethical questions that centre on the integrity of the tester to maintain professional distance and uphold the profession. This paper discusses the ethics of penetration testing and presents our conceptual model and revised taxonomy.

An analysis of CSI/FBI and AusCERT surveys

The paper responds to the release of both the AusCERT and CSI/FBI computer crime and security surveys with a comparison of the results between the two countries' respondents. Overall both surveys show the trend that most organisations employ security technologies but half of them still experience incidents which compromise their security. These incidents have significant quantifiable losses but despite these organisations are still loathed to report to law enforcement agencies for various reasons. These include the impression that law enforcement agencies are not interested, and the negative publicity such incidents can cause in their aftermath.

Australian SMES and e-security guides on trusting the internet

There have been many standards and guides written for the implementation of computer security and information security concentrating on appropriate implementation of procedures for effective information security management. Such guides are limited when dealing with e-business and its implementation by Small and Medium Business Enterprises (SMEs). In Australia the National Office for the Information Economy (NOIE) has released a small business guide for e-security for performing such services while fulfilling the necessary security requirements. This paper presents an overview of this current small business guide to e-security with special reference to deriving a common set of criteria for implementing security measures in the SME e-business environment.

Modeling and simulation of collisions of heavy trucks with concrete barriers

On-site collision tests of full-scale concrete barriers are an important method to understand what happens to concrete barriers when vehicles collide with them. However, such tests require both time and money, so modeling and simulation of collisions by computer have been developed as an alternative in this research. First, spring subgrade models were developed to formulate the ground boundary of concrete barriers based on previous experiments. Then, the finite element method models were developed for both heavy trucks and concrete barriers to simulate their dynamic collision performances. Comparison of the results generated from computer simulations and on-site experiments demonstrates that the developed models can be applied to simulate the collision of heavy trucks with concrete barriers, to replicate the movement of the truck at the collision, and to investigate the performance of the concrete barriers. The developed research methodology can be widely used to support the design of new concrete barriers and the safety analysis of existing ones.

Australian mechanical engineers : industries and attributes

The US and UK have had significant influence on the delivery and content of engineering programs both globally and particularly on Australia and yet the industrial profile of Australia has historically been significantly different from that of the US and UK. This paper first presents a study into the differences in industrial profile in the employment of mechanical engineers in the US, UK and Australia. This paper then presents key findings from a role-based study that identified the relative significance of a broad range of attributes for the most common mechanical engineering roles in the six industries that employ the greatest number of Australian mechanical engineers.

Complexes of the tripodal nitrilotrimethylenetrisphosphonic (H6L) and P,P',P''-triphenylnitrilotrimethylenetrisphosphinic (H3L) acids with the copper(II) ion. Synthesis and charaterization of [Hpy][Cu(H3L)(H2O)] and [Cu(HL)(py)]2.2Me2CO

The complexes [Hpy][Cu(H₃L)(H2O)] 1 (L⁶ = nitrilotrimethylenetrisphosphonate) and [Cu(HL°)(py)]₂·2Me₂CO 2 [(L°)³ = P,P,P" -triphenylnitrilotrismethylenetrisphosphinate)] have been isolated and characterized by X-ray crystallography, near IR-visible spectroscopy and magnetic measurements. The structure determination has shown the complexes to be constituted by monomeric and dimeric units respectively. In the monomer the metal atom is surrounded by the phosphonate ligand and a water molecule, with a geometry between a trigonal bipyramid and a square pyramid. The two copper atoms in the dimer are held together by an arm of the tripod ligand, with a pyridine molecule as additional ligand, and display octahedral geometry. The presence of monomeric and dimeric species in aqueous solutions of 1 and 2 has been shown by ESMS studies. The formation in water solution of the dimer [{Cu(H₃L)}₂]^2-, as a minor species, has been supported by potentiometric measurements, whereas only the monomeric anion [CuL°] has been ascertained to be present. In general the ligand H₃L° forms less stable copper(II) complexes than H₆L.

Mechanisms that contribute to differences in motor performance between young and old adults

This paper examines the physiological mechanisms responsible for differences in the amplitude of force fluctuations between young and old adults. Because muscle force is a consequence of motor unit activity, the potential mechanisms include both motor unit properties and the behavior of motor unit populations. The force fluctuations, however, depend not only on the age of the individual but also on the muscle group performing the task, the type and intensity of the muscle contraction, and the physical activity status of the individual. Computer simulations and experimental findings performed on tasks that involved single agonist and antagonist muscles suggest that differences in force fluctuations are not attributable to motor unit twitch force, motor unit number, or nonuniform activation of the agonist muscle, but that they are influenced by the variability and common modulation of motor unit discharge in both the agonist and antagonist muscles. Because the amplitude of the force fluctuations does not vary linearly with muscle activation, these results suggest that multiple mechanisms contribute to the differences in force fluctuations between young and old adults, although the boundary conditions for each mechanism remain to be determined.

Computer aided analysis of dental radiographic images

This paper is a result of a fruitful cooperation between the computer science and the dental diagnosis experiences. The study presents a new approach of applying computer algorithms to radiographic images of dental implantation used for bone regeneration. We focus here only on the contribution of the computer assistance to the clinical research as the periodontal therapy is beyond the scope of this paper. The proposed system is based on a pattern recognition approach, directed to recognize density changes in the intra-bony affected areas of patients. It comprises different modules with new algorithms specially designed to treat the patients’ radiographic images more accurately. The system includes digitizing, detecting the complicated region of interest (ROI), defining reference area to correct any projection discrepancy of the follow up images, and finally to extract the distinguishing features of the ROI as a basis for determining the rate of new bone density accumulation. This study is applied to two typical dental cases for a patient who received two different operations. The results are very encouraging and more accurate than traditional techniques reported before.

Modelling and simulation for manufacturing systems : challenges and benefits

Computer modelling and simulation is 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. 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 modelling and simulation in the manufacturing sector and through a number of case studies highlights the benefits gained through the use of such technologies.

A review of terrestrial bird atlases of the world and their application

We reviewed 272 bird atlases (standardised surveys intended to document the distribution of birds) from around the world. Atlases we located were conducted in 50 countries from six continents with most (82.4%) from Europe and North America. Atlases were mostly run by ornithological societies (67.1%), had amassed at least 27.9 million records of birds over an area roughly 31.4% of the land area of the Earth, and had involved at least 108 000 contributors. They had a modal data collection period of 4 years (some ran over several decades) and varied greatly in scale, covering local areas to entire continents (21 km² – 10 390 000 km²); atlases that covered larger areas involved more observers and generated more records. Most atlases (88.3%) were constrained to particular seasons, and most of these focussed on the main local breeding period (81.0%). Spatial sampling units ranged from 0.02 km² (2 ha) to 3092 km² and temporal units of sampling varied from 20 minutes to several years. Little information is available on the application of data generated by atlases. We focussed on five major atlases for which information was available. We located 97 scientific publications drawing on data from these five major atlases; papers most frequently focussed on bird distribution (26.8%), ecology (20.6%) and land-use planning (17.5%). Atlas books were cited often, 7–31 times per year. Provision of data to third parties from two major atlases (one from Australia and one from Britain and Ireland) was frequent and remarkably similar. Data were requested mostly for environmental impact studies (almost half of all requests), conservation policy and planning (~20%), research (~20%) and other mapping (~13%). Despite the uses we describe, atlas data seem under-utilised.