Spatial prediction of rufous bristlebird habitat in a coastal heathland: a GIS-based approach

1. To develop a conservation management plan for a species, knowledge of its distribution and spatial arrangement of preferred habitat is essential. This is a difficult task, especially when the species of concern is in low   abundance. In south-western Victoria, Australia, populations of the rare rufous bristlebird Dasyornis broadbenti are threatened by fragmentation of suitable habitat. In order to improve the conservation status of this species, critical habitat requirements must be identified and a system of corridors must be established to link known populations. A predictive spatial model of rufous bristlebird habitat was developed in order to identify critical areas requiring preservation, such as corridors for dispersal.
2. Habitat models generated using generalized linear modelling techniques can assist in delineating the specific habitat requirements of a species. Coupled with geographic information system (GIS) technology, these models can be extrapolated to produce maps displaying the spatial configuration of suitable habitat.
3. Models were generated using logistic regression, with bristlebird presence or absence as the dependent variable and landscape variables, extracted from both GIS data layers and multispectral digital imagery, as the predictors. A multimodel inference approach based on Akaike’s information criterion was used and the resulting model was applied in a GIS to extrapolate predicted likelihood of occurrence across the entire area of concern. The predictive performance of the selected model was evaluated using the receiver operating characteristic (ROC) technique. A hierarchical partitioning protocol was used to identify the predictor variables most likely to influence variation in the dependent variable. Probability of species presence was used as an index of habitat suitability.
4. Negative associations between rufous bristlebird presence and  increasing elevation, 'distance to cree', 'distance to coast' and sun index were evident, suggesting a preference for areas relatively low in altitude, in close proximity to the coastal fringe and drainage lines, and receiving less direct sunlight. A positive association with increasing habitat complexity also suggested that this species prefers areas containing high vertical density of vegetation.
5. The predictive performance of the selected model was shown to be high (area under the curve 0·97), indicating a good fit of the model to the data. Hierarchical partitioning analysis showed that all the variables considered had significant  independent contributions towards explaining the variation in the dependent variable. The proportion of the total study area that was predicted as suitable habitat for the rufous bristlebird (using probability of occurrence at a ≥0·5 level ) was 16%.
6. Synthesis and applications. The spatial model clearly delineated areas predicted as highly suitable rufous bristlebird habitat, with evidence of potential corridors linking coastal and inland populations via gullies. Conservation of this species will depend on management actions that protect the critical habitats identified in the model. A multi-scale  approach to the modelling process is recommended whereby a spatially explicit model is first generated using landscape variables extracted from a GIS, and a second model at site level is developed using fine-scale habitat variables measured on the ground. Where there are constraints on the time and cost involved in measuring finer scale variables, the first step alone can be used for conservation planning.

Landscape characteristics associated with species richness and occurrence of small native mammals inhabiting a coastal heathland: a spatial modelling approach

In the coastal region of south-western Victoria, Australia, populations of native small mammal species are restricted to patches of suitable habitat in a highly fragmented landscape. The size and spatial arrangement of these patches is likely to influence both the occupancy and richness of species at a location. Geographic Information System (GIS)-based habitat models of the species richness of native small mammals, and individual species  occurrences, were developed to produce maps displaying the spatial  configuration of suitable habitat. Models were generated using either generalised linear Poisson regression (for species richness) or logistic regression (for species occurrences) with species richness or  presence/absence as the dependent variable and landscape variables, extracted from both GIS data layers and multi-spectral digital imagery, as the predictor variables. A multi-model inference approach based on the Akaike Information Criterion was used and the resulting model was applied in a GIS framework to extrapolate predicted richness/likelihood of occurrence across the entire area of the study. A negative association between species  richness and elevation, habitat complexity and sun index indicated that richness within the study area decreases with increasing altitude, vertical vegetation structure and exposure to solar radiation. Landform  characteristics were important (to varying degrees) in determining habitat occupancy for all of the species examined, while the influence of habitat complexity was important for only one of the species. Performance of all but one of the models generated using presence/absence data was high, as indicated by the area under the curve of a receiver-operating characteristic plot. The effective conservation of the small mammal species in the area of concern is likely to depend on management actions that promote the protection of the critical habitats identified in the models.

Modelling habitat suitability of the swamp antechinus (Antechinus minimus maritimus) in the coastal heathlands of southern Victoria, Australia

In recent years, predictive habitat distribution models, derived by combining multivariate statistical analyses with Geographic Information System (GIS) technology, have been recognised for their utility in conservation planning. The size and spatial arrangement of suitable habitat can influence the long-term persistence of some faunal species. In southwestern Victoria, Australia, populations of the rare swamp antechinus (Antechinus minimus maritimus) are threatened by further fragmentation of suitable habitat. In the current study, a spatially explicit habitat suitability model was developed for A. minimus that incorporated a measure of vegetation structure. Models were generated using logistic regression with species presence or absence as the dependent variable and landscape variables, extracted from both GIS data layers and multi-spectral digital imagery, as the predictors. The most parsimonious model, based on the Akaike Information Criterion, was spatially extrapolated in the GIS. Probability of species presence was used as an index of habitat suitability. A negative association between A. minimus presence and both elevation and habitat complexity was evidenced, suggesting a preference for relatively low altitudes and a vegetation structure of low vertical complexity. The predictive performance of the selected model was shown to be high (91%), indicating a good fit of the model to the data. The proportion of the study area predicted as suitable habitat for A. minimus (Probability of occurrence greater-or-equal, slanted0.5) was 11.7%. Habitat suitability maps not only provide baseline information about the spatial arrangement of potentially suitable habitat for a species, but they also help to refine the search for other populations, making them an important conservation tool.

Data rich digital architectural environments

The development of data rich digital environments for the construction industry has been problematic despite the initial optimism when their application to design and construction was first considered. This paper reviews the current state of the art research into the application of information technology in design and construction and identifies the more critical issues in its adoption. In conclusion the paper then proposes a preliminary theoretical model being developed as a research tool for investigation into highly detailed information flows in a case study building renovation project. This investigation aims to track the detailed information flows and knowledge system used by the stakeholders in the building project.

More dominant in their inactivity: consumer response and the adoption of digital TV in Australia

After much hesitation, discussion, and power brokering, Australia adopted digital TV for its Free-to air broadcasting on January 1, 2001. However, by December 2002, only a few thousand homes had adopted the technology. This paper examines the implementation and regulation of digital TV in Australia from the point of view of the ‘established base’ the new technology will replace, theories on diffusion and innovation of new technologies, and the Justification Model, which sees technology choice as social gambling. It then evaluates the various protectionist regulations and limitations imposed on the technology to safeguard the various stakeholders, the implementation strategies used, lack of digital content, marketing efforts, negative media coverage, and the economic realities of the technology, and argues that if consumers reject the technology altogether, it would lead to Australia missing the future applications of digital technology and the opportunity to address the issue of the ‘digital divide’ in the 21st century.

Video lectures for cross-cultural use: a three phase model

This paper will discuss the contributing factors of; increasing numbers of international students, and the advancement of learning technologies; that lead to the development of an exploratory research study into the creation of a three phase online lecture model. Aspects such as the differences between the major cultural groups currently enrolled in Australian Universities, indicates the variations that can be expected in student learning styles. This research study aims at determining the educational value of the inclusion of online lectures for a diverse and distributed cross-cultural audience.

Fighting the digital divide with microfinance : building social capital and socio-economic development

Unlike other technology, lCT has the tremendous capacity to eliminate various social and economic barriers impeding the poor, helping them discover their potential. Wider access and use of lCT can improve social networks and increase civic engagement, thereby improving social fabric and developing social capital. Thus, scholars now have realized lCT plays a primary role in the formation and maintenance of social network. This paper identifies microfinance programs as an agent with unparalleled capacity to facilitate access to lCT and thus the formation of social capital and socio-economic development of the poor. In this paper, we also discuss the role of MFls in developing social capital in
South Asia and present an analytical model of how the intervention of microfinance can facilitate access to lCT by the poor with the result of an improved both socio-economic situation and social capital.

Creating a blended learning model for cross-cultural e-learning: putting theory into practice

This paper will discuss how blended learning has been used in cross-cultural classrooms as a means to improve the International students learning. Issues such as interaction and reuse of unit resources have been the focus of this research. This paper is about putting the theory of blended learning into practice with two teaching artifacts; an ice-breaker exercise and online lectures. Through the implementation of the two blended learning artifacts we are able to assess how the theory of blended learning really impact cross-cultural learning.

Reproducibility of digital evidence in forensic investigations

We present a three-component model of a digital investigation which comprises: determination of input-output layers, assignment of read and write operations associated with use of forensic tools, and time-stamping of read and write operations. This builds on work of several authors, culminating in the new model presented here which is generic, scalable and compatible with all functions in the system, and which is guaranteed to produce a high quality of reproducibility.

Towards a digital representation of physical phenomena to assess comfort in future environments

This paper presents the concept and a test implementation of a digital representation of the physical world designed to assess comfort quality in
future environments. An integrated set of physical phenomena is modeled three-dimensionally to investigate the dynamic behavior of design objects
holistically.

The formulation supports the integration of computational simulation in the performance-based design process. It employs the principles of
geometrical and physical selfcontainedness to avoid that complex geometrical and physical circumstances have to be specified at design time. The concepts of congeneric cells and congeneric conjunctions are
introduced to simulate various physical phenomena simultaneously with a uniformly structured set of equations.

The concept, the prototype implementation and selected test cases are presented. Although it was not possible to implement all features and model parts completely, the research and the discussion of its achievements make valuable contributions towards more effective integration of computational simulation in the performance-based design process.

A lower bound on effective performance testing for digital forensic tools

The increasing complexity and number of digital forensic tasks required in criminal investigations demand the development of an effective and efficient testing methodology, enabling tools of similar functionalities to be compared based on their performance. Assuming that the tool tester is familiar with the underlying testing platform and has the ability to use the tools correctly, we provide a numerical solution for the lower bound on the number of testing cases needed to determine comparative capabilities of any set of digital forensic tools. We also present a case study on the performance testing of password cracking tools, which allows us to confirm that the lower bound on the number of testing runs needed is closely related to the row size of certain orthogonal arrays. We show how to reduce the number of test runs by using knowledge of the underlying system

The present and the future of digital TV in Australia

Australia adopted digital TV (DTV) on January 1, 2001 but due to slow adoption by end users, the deadline to discontinue the analog signal has so far been postponed twice. This paper examines the history and current status of DTV adoption in Australia with reference to theories of adoption and diffusion and the Justification Model of Technology and why end users
appear reluctant to adopt-in spite of affordable converters. End user opinions are examined on ‘why they do not adopt’ and ‘what may encourage them to adopt’, using public submissions to the 2005 parliamentary ‘Inquiry into the uptake of digital TV in Australia’. The paper advocates relevant media literacy programs to address the low public awareness of DTV and its benefits because its rejection may result in less affluent end users losing the chance to receive a range of convergent services in the future via the ubiquitous and affordable television.

The effects of the social structure of digital networks on viral marketing performance

Viral marketing is a form of peer-to-peer communication in which individuals are encouraged to pass on promotional messages within their social networks. Conventional wisdom holds that the viral marketing process is both random and unmanageable. In this paper, we deconstruct the process and investigate the formation of the activated digital network as distinct from the underlying social network. We then consider the impact of the social structure of digital networks (random, scale free, and small world) and of the transmission behavior of individuals on campaign performance. Specifically, we identify alternative social network models to understand the mediating effects of the social structures of these models on viral marketing campaigns. Next, we analyse an actual viral marketing campaign and use the empirical data to develop and validate a computer simulation model for viral marketing. Finally, we conduct a number of simulation experiments to predict the spread of a viral message within different types of social network structures under different assumptions and scenarios. Our findings confirm that the social structure of digital networks play a critical role in the spread of a viral message. Managers seeking to optimize campaign performance should give consideration to these findings before designing and implementing viral marketing campaigns. We also demonstrate how a simulation model is used to quantify the impact of campaign management inputs and how these learnings can support managerial decision making.

Using relationship-building in event profiling for digital forensic investigations

In a forensic investigation, computer profiling is used to capture evidence and to examine events surrounding a crime. A rapid increase in the last few years in the volume of data needing examination has led to an urgent need for automation of profiling. In this paper, we present an efficient, automated event profiling approach to a forensic investigation for a computer system and its activity over a fixed time period. While research in this area has adopted a number of methods, we extend and adapt work of Marrington et al. based on a simple relational model. Our work differs from theirs in a number of ways: our object set (files, applications etc.) can be enlarged or diminished repeatedly during the analysis; the transitive relation between objects is used sparingly in our work as it tends to increase the set of objects requiring investigative attention; our objective is to reduce the volume of data to be analyzed rather than extending it. We present a substantial case study to illuminate the theory presented here. The case study also illustrates how a simple visual representation of the analysis could be used to assist a forensic team.