Fast computation of trimmed means

We present two methods of calculating trimmed means without sorting the data in O(n) time. The existing method implemented in major statistical packages relies on sorting, which takes O(n log n) time. The proposed algorithm is based on the quickselect algorithm for calculating order statistics with O(n) expected running time. It is an order of magnitude faster than the existing method for large data sets.

Comparison of Two Methods for Caluculating the Partition Functions of Various Spatial Statistical Models

Likelihood computation in spatial statistics requires accurate and efficient calculation of the normalizing constant (i.e. partition function) of the Gibbs distribution of the model. Two available methods to calculate the normalizing constant by Markov chain Monte Carlo methods are compared by simulation experiments for an Ising model, a Gaussian Markov field model and a pairwise interaction point field model.

A comparative study of some computer algebra packages which determine the lie point symmetries of differential equations

The study seeks to determine which of five computer algebra packages is best at finding the Lie point symmetries of systems of partial differential equations with minimal user intervention. The chosen packages are LIEPDE and DIMSYM for REDUCE, LIE and BIGLIE for MUMATH, DESOLV for MAPLE, and MATHLIE for MATHEMATICA. A series of systems of partial differential equations are used in the study. The paper concludes that while all of the computer packages are useful, DESOLV appears to be the most successful system at determining the complete set of Lie point symmetries of systems of partial differential equations.

Does the use of computer assisted learning packages improve performance in accounting?

This study examines the factors affecting student performance in an undergraduate financial accounting course, utilising Computer Assisted Learning (CAL). Multiple regression analysis on student performance shows that positive perceptions of the usefulness of CAL significantly influenced performance. It was also found that International students had significantly poorer performance than local students. This result may be attributed to transitional problems experienced by these students, given their different pathways to university study Prior studies of accounting and computing at secondary school level, together with gender, were not significant influences on performance. The results have implications for accounting educators utilising CAL in courses as a means of improving students understanding of accounting concepts and as a means of providing efficient and effective educational instruction to maximise learning outcomes in accounting.

Performance of statistical inference for block classification in reducing blocking artefact in video coded images

This paper presents a performance study of four statistical test algorithms used to identify smooth image blocks in order to filter the reconstructed image of a video coded image. The four algorithms considered are the Coefficient of Variation (CV), Exponential Entropy of Pal and Pal (E), Shannon's (Logarithmic) Entropy (H), and Quadratic Entropy (Q). These statistical algorithms are employed to distinguish between smooth and textured blocks in a reconstructed image. The linear filtering is carried out on the smooth blocks of the image to reduce the blocking artefact. The rationale behind applying the filter on the smooth blocks only is that the blocking artefact is visually more prominent in the smooth region of an image rather than in the textured region.

The role of computer assisted learning packages in determining learning outcomes of accounting students

This study examines the factors affecting student performance in an undergraduate financial accounting course, utilising Computer Assisted Learning (CAL) and use of a commercial software package. Multiple regression analysis was undertaken to examine the influences of perceptions of CAL and QuickBooks Pro, together with background variables such as gender, entry pathway and prior knowledge had on student performance. The results show that perceptions of CAL together with entry pathway were significant predictors of student performance. However, perceptions of the ,usefulness of QuickBooks Pro, prior studies of accounting and computing, together with gender, were not significant influences on performance. In terms of entry pathway it was found that International students, many of whom entered the university at the second year level having obtained advanced standing credits, had significantly poorer performance than local students. This result may be attributed to transitional problems experienced by these students, given their different pathways to university study.

The results have implications for accounting educators utilising CAL in courses as a means of improving students understanding of accounting concepts. The study also provides reflections on the use of CAL and a commercial software package as a means of providing efficient and effective educational instruction to maximise learning outcomes in accounting.

Training packages and the AQTF: freedom to move or components of a compliance-driven straightjacket?

This paper reports on a PhD research project being undertaken through the Faculty of Education, Deakin University. Training Packages and the Australian Quality Training Framework (AQTF) form part of the ruling relations of VET, but how do they operate in practice? Do they provide frameworks within which training professionals are free to use judgement and respond in innovative ways to local learning and assessment contexts? Do they impose rigid 'guidelines' within which the decision-making authority of practitioners over appropriate practices is displaced by that of auditors, constraining creativity and creating pressures towards conformity? Or does their impact vary, depending on how they are interpreted and who is doing the interpreting? My PhD research explores issues relating to the use of Training Packages in workbased learning. Interview data suggests that, in practice, different training organisations respond very differently to a regulatory framework that aims to achieve national consistency. Some practitioners describe working in a compliance-driven environment, in which their ability to meet the needs of learners is stifled by standardised training and assessment practices imposed by Training Packages and the AQTF. This view is reflected in phrases such as 'you're not allowed to…', and 'you always feel uneasy because you've got AQTF compliance, inspections, auditors'. In contrast, other practitioners talk about having freedom to design learning and assessment programs for their particular target group and context, providing they stay within broad guidelines that guarantee national recognition of qualifications they issue. This view is reflected in comments such as 'it just leaves it open … to be as creative and flexible as you like', and 'It just gives us freedom'. This paper explores the proposition that the impact of these abstract and generalised texts is influenced by local interpretations, and it considers the role that organisational culture plays in determining these interpretations.

Benchmarking new statistical techniques in ration-based modelling of corporate collapse

Up until 1979, Multiple Discriminant Analysis (MDA) was the primary multivariate methodological approaches to ratio-based modelling of corporate collapse. However, as new statistical tools became available, researchers started testing them with the primary objective of deriving models that would at least do as good a job as MDA, but that rely on fewer assumptions. Regardless of which methodological approach was chosen, most were compared to MDA. This paper analyses 84 studies on ratio based modelling of corporate collapse over the period 1968 to 2004. The results indicate that when MDA was not the primary methodology it was the benchmark of choice for comparison; thereby, demonstrating its importance as a foundation multivariate methodological approach in signalling corporate collapse.

A flow control methodology for the rapid generation of vehicle traffic models

This paper presents a conveyor-based methodology to model complex vehicle flows common to factory and distribution warehouse facilities. The AGV and human path modelling techniques available in many commercial discrete event simulation packages require extensive knowledge and time to implement even the simplest flow control rules for multiple vehicle interaction. Although discrete event simulation is accepted as an effective tool to model vehicle delivery movements, human paths and delivery schedules for modern assembly lines, the time to generate accurate models is a significant limitation of existing simulation-based optimisation methodologies. The flow control method has been successfully implemented using two commercial simulation packages. It provides a realistic visual representation, as well as accurate statistical results, and reduces the model development process cost.

Identifying cis-regulatory elements by statistical analysis and phylogenetic footprinting and analyzing their coexistence and related gene ontology

Discovery of cis-regulatory elements in gene promoters is a highly challenging research issue in computational molecular biology. This paper presents a novel approach to searching putative cis-regulatory elements in human promoters by first finding 8-mer sequences of high statistical significance from gene promoters of humans, mice, and Drosophila melanogaster, respectively, and then identifying the most conserved ones across the three species (phylogenetic footprinting). In this study, a conservation analysis on both closely related species (humans and mice) and distantly related species (humans/mice and Drosophila) is conducted not only to examine more candidates but also to improve the prediction accuracy. We have found 124 putative cis-regulatory elements and grouped these into 20 clusters. The investigation on the coexistence of these clusters in human gene promoters reveals that SP1, EGR, and NRF-1 are the dominant clusters appearing in the combinatorial combination of up to five clusters. Gene Ontology (GO) analysis also shows that many GO categories of transcription factors binding to these cis-regulatory elements match the GO categories of genes whose promoters contain these elements. Compared with previous research, the contribution of this study lies not only in the finding of new cis-regulatory elements, but also in its pioneering exploration on the coexistence of discovered elements and the GO relationship between transcription factors and regulated genes. This exploration verifies the putative cis-regulatory elements that have been found from this study and also gives new insight on the regulation mechanisms of gene expression.

Implementing training packages in a TAFE institute: perceptions and concerns of staff

The advent of training packages is a further change to the vocational education and training sector and is currently being implemented by teaching professionals. This paper outlines the findings of a project involving teachers in a TAFE institution as they begin the process of implementing the cross-industry Laboratory Operations Training Package into their teaching centre. The impetus for the research was the recognition that the change brought about by the new initiative would present a challenge for the teachers and a further change to their role in vocational education and training (VET). The research was qualitative in the form of a case study. Findings demonstrated that the implementation required a significant change in the philosophy of educational practice within the centre and that the implementation process was causing the teachers anxiety and confusion.