Using mobile agents to recover from node and database compromise in path-based DoS attacks in wireless sensor networks

Wireless sensor networks represent a new generation of real-time embedded systems with significantly different communication constraints from the traditional networked systems. With their development, a new attack called a path-based DoS (PDoS) attack has appeared. In a PDoS attack, an adversary, either inside or outside the network, overwhelms sensor nodes by flooding a multi-hop end-to-end communication path with either replayed packets or injected spurious packets. Detection and recovery from PDoS attacks have not been given much attention in the literature. In this article, we consider wireless sensor networks designed to collect and store data. In a path-based attack, both sensor nodes and the database containing collected data can be compromised. We propose a recovery method using mobile agents which can detect PDoS attacks easily and efficiently and recover the compromised nodes along with the database.

Australia and New Zealand: separate states but path-dependent

Australia and New Zealand (Aotearoa) have shared almost two centuries of close relations created through close geographic proximity, shared membership of political associations, and frequent policy exchange. The relevant context has shifted from the British Empire and Commonwealth to a rapidly globalizing world under US military hegemony. Australia and New Zealand were among the early settler colonies of the British Empire and this article argues that, as such, the settler colonies helped shape the form of the Empire, and subsequently the Commonwealth. This history created strong, separate, if somewhat similar, traditions of independent political experimentation. This article explores different models for explaining the cross-Tasman relationship and concludes that the path-dependent approach works best. The path was also influenced by external shocks, notably the second world war and Britain's moves towards Europe, and it was these shocks that created the necessary ruptures to create change. The first world war had catapulted Australia and New Zealand towards separate nationhood, and simultaneously strengthened their cultural and political links. The second world war pushed Australia towards the USA and led both Australia and New Zealand to develop a more explicit role as regional leaders in the Pacific. For New Zealand, Britain's membership of the European Community created an economic crisis and politico-cultural stresses which are reverberating still. Such shocks created the preconditions also for closer association, exemplified in the CER Treaty, which in turn draws upon historical precedents and experiences.

Corporate sustainability : greenwash or a path to sustainable capitalism?

The problems of unsustainable development and the increased-awareness of corporate power in the global era have contributed to an agenda of corporate citizenship. This thesis explores the meanings and practices that fall under the banner of the triple bottom line of corporate citizenship through forty-two in-depth interviews with representatives from the corporate sector and NGO sector (including trade unions) in Australia. This purposive sample includes a specific range of corporate industries and NGO types, all of which have involvement with various areas of sustainability. Interviewees described their feelings and experiences in relation to the concept of the triple bottom line, the potential and limitations of this type of sustainability and the purpose and impacts of partnerships between NGOs and the corporate sector. On the basis of this research, this thesis argues that corporate citizenship is at best, a set of initiatives for making minor adjustments to the way companies perform their day-to-day operations and at worst, a program for improving corporate image rather than performance and for shifting the agenda of sustainable development toward corporate interests. While radical steps are required to achieve a sustainable society and environment, the terms of corporate citizenship offer very limited opportunities for change. The self-regulatory and market based model of citizenship does not challenge the impact of consumerism or the legitimacy of particular industry types and their products, except where threats are perceived to the longevity of the companies involved. Furthermore, while the exploitation of the environment and society has occurred as a result of corporate self-interest, corporate citizenship is justified on the same basis. The self-interest rationale and the tyranny of the economic bottom line in particular, substantially limit the fields of responsibility that can be included in the citizenship paradigm. While there are undoubtedly some well-intentioned corporate representatives who are working toward attaining a more sustainable corporate culture, the discourse is primarily used to shift the sustainable development agenda toward corporate paradigms and interests.

Ecosystem services of tropical dry forests : insights from longterm ecological and social research on the Pacific coast of Mexico

In the search for an integrated understanding of the relationships among productive activities, human well-being, and ecosystem functioning, we evaluated the services delivered by a tropical dry forest (TDF) ecosystem in the Chamela Region, on the Pacific Coast of Mexico. We synthesized information gathered for the past two decades as part of a long-term ecosystem research study and included social data collected in the past four years using the Millennium Ecosystem Assessment (MA) conceptual framework as a guide. Here we identify the four nested spatial scales at which information has been obtained and emphasize one of them through a basin conceptual model. We then articulate the biophysical and socio-economic constraints and drivers determining the delivery of ecosystem services in the Region. We describe the nine most important services, the stakeholders who benefit from those services, and their degree of awareness of such services. We characterize spatial and temporal patterns of the services’ delivery as well as trade-offs among services and stakeholders. Finally, we contrast three alternative future scenarios on the delivery of ecosystem services and human well-being. Biophysical and socioeconomic features of the study site strongly influence human−ecosystem interactions, the ecosystem services delivered, the possible future trajectories of the ecosystem, and the effect on human well-being. We discuss future research approaches that will set the basis for an integrated understanding of human−ecosystem interactions and for constructing sustainable management strategies for the TDF.

Keeping all students on the learning path

A powerful notion to guide thinking about whole-class mathematics teaching is Vygotsky’s zone of proximal development (ZPD). Our research with primary and secondary teachers over the last six years has identified roles of teachers in relation to the ZPD, and ways of overcoming some typical barriers to students’ movement through their zones. Methods have included focus groups of experts, video analysis of classroom interactions, classroom observation, and analysis of lesson plans and teachers’ reflections teaching processes their outcomes. The research has involved the gradual development, trailing, evaluation, and adjustment of a six-component model for planning and teaching mathematics. The focus of this paper is on the use of one of its components, “differentiated learning trajectories”.

Effect of cold drawing on subsequent surface strain path and ductility during upsetting

Cold drawing is a process that sizes and smooths the surface of steel before it is cold headed to produce bolts. The effect of the changes in the mechanical properties due to cold drawing on the surface strain and ductility during the upsetting process was analysed showing that the stress and strain state can be more readily altered by changes in the process conditions (friction and height-to-diameter ratio) to cause greater increase in the failure strains than can be achieved by pre-drawing.

Development of an optimum factory model for a manufacturing operation through computer simulation

Often manufacturing enterprises will maintain high levels of Work In Progress (WIP) to maximise production throughput. Using computer simulation, this thesis investigates a manufacturing facility and identifies an optimal level of WIP. At this optimum throughput is maximised, manufacturing lead times are minimised, and the WIP level is significantly reduced.

Multilabel classification by BCH code and random forests

This paper uses error correcting codes for multilabel classification. BCH code and random forests learner are used to form the proposed method. Thus, the advantage of the error-correcting properties of BCH is merged with the good performance of the random forests learner to enhance the multilabel classification results. Three experiments are conducted on three common benchmark datasets. The results are compared against those of several exiting approaches. The proposed method does well against its counterparts for the three datasets of varying characteristics.

Factors affecting SMEs' willingness to share knowledge online : a path model

This paper presents the findings of a study of SME owner-managers that examined their willingness to share information online with other members of a local business network. The main variables associated with willingness to share knowledge online were found to be willingness to share information in conventional modes and the intensity with which they used the internet for business activities. A number of other variables were found to be indirectly or unrelated to willingness to share knowledge online. A significant locality effect was also identified which suggests that the social context of the network to which the business belonged influences willingness to share knowledge online. Our work supports previous research which concludes that online knowledge sharing initiatives should enhance relationships within the business network itself as well as the technical aspects of the networking platform and the technical competence of potential users.

Underestimated and severe : small mammal decline from the forests of south-eastern Australia since European settlement, as revealed by a top-order predator

In Australia, numerous small mammal species have suffered extinction or severe declines in distribution and abundance following European settlement. The extent of these declines from forested areas of south-eastern Australia, however, remains poorly understood. In this paper we use sub-fossil deposits of the sooty owl (Tyto tenebricosa tenebricosa) as a tool for understanding the diversity of the small mammal palaeocommunity. These results are compared to the contemporary sooty owl diet from the same geographical region to investigate the degree of small mammal decline following European settlement. Of 28 mammal species detected in sub-fossil deposits and considered prey items of the sooty owl at the time of European settlement, only 10 species were detected in the contemporary sooty owl diet. Numerous small mammal species have not only recently suffered severe declines in distribution and abundance but have also recently undergone niche contraction, as they occupied a greater diversity of regions and habitats at the time of European settlement. For some species our understanding of their true ecological niche and ecological potential is therefore limited. The species that underwent the greatest declines occupied open habitat types or were terrestrial. The severity of decline is also likely to have resulted in severe disruption of ecosystem functions, with wide scale ecosystem consequences. There is an urgent need to improve small mammal conservation, to maintain crucial ecosystem functions performed by small mammals. It is recommended that broad-scale exotic predator control programs are conducted which may also provide suitable conditions for the re-introduction of locally extinct species.