Development of DAL and DAPL languages for building distributed applications

A common characteristic among parallel/distributed programming languages is that the one language is used to specify not only the overall organisation of the distributed application, but also the functionality of the application. That is, the connectivity and functionality of processes are specified within a single program. Connectivity and functionality are independent aspects of a distributed application. This thesis shows that these two aspects can be specified separately, therefore allowing application designers to freely concentrate on either aspect in a modular fashion. Two new programming languages have been developed for specifying each aspect. These languages are for loosely coupled distributed applications based on message passing, and have been designed to simplify distributed programming by completely removing all low level interprocess communication. A suite of languages and tools has been designed and developed. It includes the two new languages, parsers, a compilation system to generate intermediate C code that is compiled to binary object modules, a run-time system to create, manage and terminate several distributed applications, and a shell to communicate with the run-tune system. DAL (Distributed Application Language) and DAPL (Distributed Application Process Language) are the new programming languages for the specification and development of process oriented, asynchronous message passing, distributed applications. These two languages have been designed and developed as part of this doctorate in order to specify such distributed applications that execute on a cluster of computers. Both languages are used to specify orthogonal components of an application, on the one hand the organisation of processes that constitute an application, and on the other the interface and functionality of each process. Consequently, these components can be created in a modular fashion, individually and concurrently. The DAL language is used to specify not only the connectivity of all processes within an application, but also a cluster of computers for which the application executes. Furthermore, sub-clusters can be specified for individual processes of an application to constrain a process to a particular group of computers. The second language, DAPL, is used to specify the interface, functionality and data structures of application processes. In addition to these languages, a DAL parser, a DAPL parser, and a compilation system have been designed and developed (in this project). This compilation system takes DAL and DAPL programs to generate object modules based on machine code, one module for each application process. These object modules are used by the Distributed Application System (DAS) to instantiate and manage distributed applications. The DAS system is another new component of this project. The purpose of the DAS system is to create, manage, and terminate many distributed applications of similar and different configurations. The creation procedure incorporates the automatic allocation of processes to remote machines. Application management includes several operations such as deletion, addition, replacement, and movement of processes, and also detection and reaction to faults such as a processor crash. A DAS operator communicates with the DAS system via a textual shell called DASH (Distributed Application SHell). This suite of languages and tools allowed distributed applications of varying connectivity and functionality to be specified quickly and simply at a high level of abstraction. DAL and DAPL programs of several processes may require a few dozen lines to specify as compared to several hundred lines of equivalent C code that is generated by the compilation system. Furthermore, the DAL and DAPL compilation system is successful at generating binary object modules, and the DAS system succeeds in instantiating and managing several distributed applications on a cluster.

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.

A systematic grounded approach to the development of complex interventions : The Australian WorkHealth Program – Arthritis as a case study

Despite demands for evidence-based research and practice, little attention has been given to systematic approaches to the development of complex interventions to tackle workplace health problems. This paper outlines an approach to the initial stages of a workplace program development which integrates health promotion and disease management. The approach commences with systematic and genuine processes of obtaining information from key stakeholders with broad experience of these interventions. This information is constructed into a program framework in which practice-based and research-informed elements are both valued. We used this approach to develop a workplace education program to reduce the onset and impact of a common chronic disease – osteoarthritis.

To gain information systematically at a national level, a structured concept mapping workshop with 47 participants from across Australia was undertaken. Participants were selected to maximise the whole-of-workplace perspective and included health education providers, academics, clinicians and policymakers. Participants generated statements in response to a seeding statement: Thinking as broadly as possible, what changes in education and support should occur in the workplace to help in the prevention and management of arthritis? Participants grouped the resulting statements into conceptually coherent groups and a computer program was used to generate a ‘cluster map’ along with a list of statements sorted according to cluster membership.

In combination with research-based evidence, the concept map informed the development of a program logic model incorporating the program's guiding principles, possible service providers, services, training modes, program elements and the causal processes by which participants might benefit. The program logic model components were further validated through research findings from diverse fields, including health education, coaching, organisational learning, workplace interventions, workforce development and osteoarthritis disability prevention.

In summary, wide and genuine consultation, concept mapping, and evidence-based program logic development were integrated to develop a whole-of-system complex intervention in which potential effectiveness and assimilation into the workplace for which optimised.

The "strugglers" in selected computer based mathematics classrooms

In this paper, the experiences of lower achieving mathematics students in two secondary mathematics classrooms in which computers were regularly used are described. A year 8 and a year 9 mathematics class from one secondary school participated in the ethnographic study. The results show that in these two classrooms the learning relationships and power relationships did not, in general, support the learning and engagement of lower achievers in mathematics. Research into computer based teaching methods that engage low achieving students in computer based mathematics is needed.

SAS macros for point and interval estimation of area under the receiver operating characteristic curve for non-proportional and proportional hazards Weibull models

Aims and objectives  For prediction of risk of cardiovascular end points using survival models the proportional hazards assumption is often not met. Thus, non-proportional hazards models are more appropriate for developing risk prediction equations in such situations. However, computer program for evaluating the prediction performance of such models has been rarely addressed. We therefore developed SAS macro programs for evaluating the discriminative ability of a non-proportional hazards Weibull model developed by Anderson (1991) and that of a proportional hazards Weibull model using the area under receiver operating characteristic (ROC) curve.

Method  Two SAS macro programs for non-proportional hazards Weibull model using Proc NLIN and Proc NLP respectively and model validation using area under ROC curve (with its confidence limits) were written with SAS IML language. A similar SAS macro for proportional hazards Weibull model was also written.

Results  The computer program was applied to data on coronary heart disease incidence for a Framingham population cohort. The five risk factors considered were current smoking, age, blood pressure, cholesterol and obesity. The predictive ability of the non-proportional hazard Weibull model was slightly higher than that of its proportional hazard counterpart. An advantage of SAS Proc NLP in terms of the example provided here is that it provides significance level for the parameter estimates whereas Proc NLIN does not.

Conclusion  The program is very useful for evaluating the predictive performance of non-proportional and proportional hazards Weibull models.

The role of the computer in learning ndjébbana

While Computer Assisted Language Learning (CALL) is being superseded by an integrated approach to language learning and technology, it still has great potential to assist indigenous peoples in becoming print-literate in their own languages. This can also help to combat the disempowerment experienced by indigenous people as their world is penetrated by others with radically different backgrounds. This paper reports on research on an application of CALL implemented among the Kunibídji, a remote, indigenous Australian community. It focuses on the use of talking books in Ndjébbana, a language with only 200 speakers; the books were displayed on touch-screens at various locations in the community. Investigations into the roles of the computer to support language learning and cultural understanding are also reported. The computer was found to be a useful tool in promoting Kunibídji collaboration and cultural transformation.

Development and evaluation of a computer-based, self-management tool for people recently diagnosed with type 2 diabetes

Aim. The purpose of this study was to develop and evaluate a computer-based, dietary, and physical activity self-management program for people recently diagnosed with type 2 diabetes. Methods. The computer-based program was developed in conjunction with the target group and evaluated in a 12-week randomised controlled trial (RCT). Participants were randomised to the intervention (computer-program) or control group (usual care). Primary outcomes were diabetes knowledge and goal setting (ADKnowl questionnaire, Diabetes Obstacles Questionnaire (DOQ)) measured at baseline and week 12. User feedback on the program was obtained via a questionnaire and focus groups. Results. Seventy participants completed the 12-week RCT (32 intervention, 38 control, mean age 59 (SD) years). After completion there was a significant between-group difference in the "knowledge and beliefs scale" of the DOQ. Two-thirds of the intervention group rated the program as either good or very good, 92% would recommend the program to others, and 96% agreed that the information within the program was clear and easy to understand. Conclusions. The computer-program resulted in a small but statistically significant improvement in diet-related knowledge and user satisfaction was high. With some further development, this computer-based educational tool may be a useful adjunct to diabetes self-management. This trial is registered with clinicaltrials.gov NCT number NCT00877851.

Evaluation of the usefulness of 'Marvin'; a computerized assessment tool for investigative interviewers of children

This study examined the usefulness of a computerized developmental assessment tool, designed to provide investigative interviewers with knowledge about children's understanding of spatial, temporal, numerical, and color terms that may be relevant to the forensic setting. Specifically, the effect of the computer program (compared to a standard verbal and no assessment) was examined on 4- to 5-year-old children's recall of an independent event and their enjoyment of the interview process. In addition, children's performance on the computerized and verbal developmental assessment was compared with their performance when recalling the independent event. Overall, the children rated the assessment conducted on computer more favorably than the verbal assessment. Further, the verbal assessment elicited responses that were more consistent with their responses about the event than the computerized assessment. However, there was no difference in the accuracy and detail of children's responses about the independent event, irrespective of whether the children received the computerized or verbal assessment, or no assessment. Directions for future research are discussed.

Eliciting children's recall of events: how do computers compare with humans?

This study investigated the usefulness of an interactive computer program in eliciting children's reports about an event. Fifty-four 5–6- and fifty-nine  7–8-year old children participated in an event with their regular class teacher which involved several activities and a mildly negative secret. Four days and again 14 days later, the children were interviewed individually by computer (alone) or by a human interviewer. The computer program incorporated animation and audio whereby an animated figure asked the questions and the children were required to provide a verbal response. The accuracy and detail of the children’s reports was similar across the interview conditions. The children were more willing to review their answers with the computer than the adult interviewer. However, responses to the computer were less consistent across the interviews, and the children were less willing to disclose the secret in the second interview to the computer compared with the human interviewer. Overall, the computer revealed little benefit in eliciting children’s recall of the event over the standard face-to-face interview.

How well does club head speed correlate with gold handicaps?

The velocity at which a golf club impacts with a golf ball is known as club head speed. Although club head speed has been used to measure performance changes in a number of golf studies, it has not been validated as a golf performance measure. As handicap is the usual measure of performance, the purpose of this study was to investigate the relationship between club head speed and handicap, and to determine whether club head speed at impact is a valid measure of golfing performance. Forty-five male golfers aged 18–80 years, all with registered golfing handicaps (2–27), participated in this study. Each golfer performed 10 golf swings captured by a high-speed camera. Golfers' club head speeds were determined using Video Expert 2, a biomechanical computer program. Golfers with a lower handicap (ie, a better skill level) had faster club head speeds than higher handicap golfers. Linear regression analysis found club head speed to be highly correlated with handicap (r= 0.950). This relationship was described by the equation: In (club head speed)= 4.065 − 0.0214 x handicap. In conclusion, this study has shown that club head speed is a valid indicator of performance in golfers and may therefore be a useful performance measure in future laboratory-based studies.

Accuracy of body size estimation: Role of biopsychosocial variables

This study evaluated factors related to the perceptual disturbances of body image. Using a digital body image computer program, 191 participants (107 women, 82 men) adjusted an image of their body to the perceived actual size at five body regions; chest, waist, hips, thighs and calves. A neutral object (a vase) was also adjusted to partial out the level of perceptual distortion present with a neutral object. Men and women overestimated the size of the neutral object and their body image. Among women, overestimation was primarily predicted by high levels of depression, and media and peer influences to be thinner and increase muscles. Among men, overestimation was predicted by high BMI, media influences to lose weight and increase muscles, and peer influences to increase muscles. These findings suggest that perceptual accuracy of body image is primarily predicted by biopsychosocial influences.