Performance improvements to the AODV routing protocol and multiple hop wireless routes : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Engineering in Computer Systems Engineering at Massey University, Palmerston North, New Zealand

This research focused on improving the performance of the Ad-hoc On-demand Distance Vector (AODV) routing protocol over multiple hop routes. The two specific areas that this research addressed were the dramatic decrease in throughput over multiple hop IEEE 802.11 wireless routes and the problems caused by the use of hello messages by AODV implementations to detect broken routes. To help ensure that this research was suitable for real world scenarios, only off-the-shelf software and hardware was used for both the implementations and the tests. This thesis firstly presents an overview of IEEE 802.11 based wireless networking and the AODV protocol, along with wireless networking and networking in general within the Linux operating system. The thesis then presents the problems caused by hello messages and shows how the IEEE 802.11 wireless standard contributes to the dramatic decrease in throughput over multiple hop routes. To overcome the hello message problems, an AODV implementation was developed which used existing mechanisms on the data link layer, specifically the transmit retry limit, rather then hello messages to detect broken links. To address the multiple hop route throughput problem, the use of two and four IEEE 802.11 based wireless network interfaces per node were investigated, rather than using just a single wireless interface per node. These proposed solutions, and the AODV implementation that was developed as part of this research, were then tested in the areas of functionality and throughput performance improvements. The thesis concludes by presenting the performance improvements resulting from using multiple interfaces per node and the non hello message based AODV implementation along with outlining possible future research in this area

The specification of a consumer design toolkit to support personalised production via additive manufacturing

This thesis stems from the future scenario that as additive manufacturing (AM) technologies become cheaper and more readily available, consumers without formal design training will begin to customise, design and manufacture their own products. Much of this activity is likely to infringe on brands' intellectual property. The research explores the feasibility of a situation in which, rather than attempting to prohibit such activity, manufacturers engage with consumers to facilitate it, thus retaining control (albeit reduced) over their brand's image and the quality of products offered. The research begins with a literature review encompassing AM technologies and their adoption by consumers; mass customisation (MC) and the management of variation in product offering; and traditional models of industrial design (ID), including user-centred design and co-design. It finds that conventional definitions of MC and ID are unable to provide for the possibility of consumer intervention in the shape and non-modular configuration of products. Further research was then conducted in the areas of Open Design (including crowdsourcing, open sourcing and 'hardware hacking') as well as bespoke customisation, which were found to be much more accommodating of the scenario proposed. A new term, 'consumer design', is introduced and defined, together with the hypothesis that in future, the role of the industrial designer may be to design 'unfinished' products. An original classification of consumer involvement in ID is presented. Empirical research, undertaken with consumers using an iterative design software package (Genoform), demonstrated a preference for designing within pre-determined boundaries. Action research was conducted to assess consumer-oriented 3D CAD software, and compare its capabilities with that of MC toolkits. A survey of senior designers and brand managers revealed strategies for implementing and managing a brand's product design language, and a guide was created to show the relative importance of designed features. Using these findings, a prototype toolkit was created to demonstrate how a brand might facilitate consumer interaction with the shape design of a complex consumer electronics product (in this case a mobile phone). The toolkit was tested with both consumers and experienced designers to assess its viability. The research finds that it is possible to create a consumer-design toolkit which enables untrained users to change the form of a product, whilst maintaining brand equity and ensuring the product's functionality and manufacturability

The specification of a consumer design toolkit to support personalised production via additive manufacturing

The specification of a consumer design toolkit to support personalised production via additive manufacturin

Semantic Web Integration of Cultural Heritage Sources

In this paper, we describe research into the use of ontologies to integrate access to cultural heritage and photographic archives. The use of the CIDOC CRM and CRM Core ontologies are described together with the metadata mapping methodology. A system integrating data from four content providers will be demonstrated

Solomon Islands in Transition

The authors discuss the current transitions taking place in the Solomon Islands. They argue that while the gradual drawdown of the Regional Assistance Mission to Solomon Islands (RAMSI) is important, it is not the only significant change that is occurring in Solomon Islands and that the short-term policy focus on managing the mission's smooth exit should not obscure what are arguably much larger and more significant transitional challenges facing this small Pacific island country. This In Brief was first published as an item on the Development Policy Centre's DevPolicy Blog.AusAI

Sustaining the Gains in Post-RAMSI Solomon Islands

The Regional Assistance Mission to Solomon Islands (RAMSI) recently concluded at an estimated cost to Australia of AU$2.6 billion between 2003 and 2013. RAMSI was originally conceived in the ‘state-building moment’ that shaped Western responses to ‘state failure’ in the late 1990s and first decade of the new millennium. That moment has now passed, with renewed fiscal austerity, growing scepticism about liberal interventionism, as well as organisational changes and policy shifts in Australia’s foreign relations. Drawing on a recent workshop presentation (Allen and Dinnen forthcoming), we consider how post-RAMSI donor assistance can help sustain gains made over the past decade. Referencing research in rural Solomons and neighbouring Bougainville, we sketch some possibilities for hybrid forms of institutional and economic development capable of accommodating the strengths of both local and liberal orders.AusAI

eCHASE: Exploiting Cultural Heritage using the Semantic Web

The eCHASE project is using semantic web technologies to demonstrate sustainable business models based on access and exploitation of digital cultural heritage content at a European level. In this paper we describe the eCHASE project and outline the system architecture

Adaption of Self-Phasing Antenna Systems to Space Missions

The ability of the self-phasing antennas to nor only provide high gain but also to minimize the requirement of satellite attitude control has rendered them very attractive for use in satellite communication systems. The potential advantages and versatility afforded by self-phasing antennas are analyzed in this paper with discussions of results obtained for two specific applications. The paper begins with a description of two types of self-phasing antennas., namely^ the Van Atta array and the so-called phase conjugation array; similarities and differences in operation of the two types of arrays of various geometrical configurations such as planar^ cylindrical^ and spherical^ are then discussed. Problem areas which are common to both types are indicated and techniques such as array scaling and frequency translation which are useful in dealing with some of these problems are also included in the discussion. Examples of two specific applications of self-phasing antennas are used to demonstrate their attractive features. The first involves the use of self-phasing arrays on a communication satellite in a critically inclined elliptic orbit. The second deals with the mutual acquisition problem between two vehicles employing selfphasing antennas for space to space communication. In the latter application^ the finite Markov chain technique, is used to analyze the problem and the results are compared with those of the corresponding problem wherein the satellites employ narrow beam antennas pointing at each other to accomplish acquisition. The acquisition condition which would render a self-phasing system more attractive than a narrow beam system are indicated

Pack Density Limitations of Hybrid Parachutes

The development and testing of the Orion crew capsule parachute system has provided a unique opportunity to study dense parachute packing techniques and limits, in order to establish a new baseline for future programs. The density of parachute packs has a significant influence on vibration loads, retention system stresses, and parachute mortar performance. Material compositions and pack densities of existing designs for space capsule recovery were compared, using the pack density of the Apollo main parachutes as the current baseline. The composition of parachutes has changed since Apollo, incorporating new materials such as Kevlar , Vectran , Teflon and Spectra . These materials have different specific densities than Nylon, so the densities of hybrid parachute packs cannot be directly compared to Nylon parachutes for determination of feasibility or volume allocation. Six parachute packs were evaluated in terms of weighted average solid density in order to achieve a non-dimensional comparison of packing density. Means of mitigating damage due to packing pressure and mortar firing were examined in light of the Capsule Parachute Assembly System (CPAS) and Apollo experience. Parachute design improvements including incorporation of modern materials and manufacturing processes serves to make CPAS the new knowledge base on which future spacecraft parachute systems will be built