Keyframe Tagging: Unambiguous Content Delivery for Augmented Reality Environments

Context: When considering the use of Augmented Reality to provide navigation cues in a completely unknown environment, the content must be delivered into the environment with a repeatable level of accuracy such that the navigation cues can be understood and interpreted correctly by the user. Aims: This thesis aims to investigate whether a still image based reconstruction of an Augmented Reality environment can be used to develop a content delivery system that providers a repeatable level of accuracy for content placement. It will also investigate whether manipulation of the properties of a Spatial Marker object is sufficient to reduce object selection ambiguity in an Augmented Reality environment. Methods: A series of experiments were conducted to test the separate aspects of these aims. Participants were required to use the developed Keyframe Tagging tool to introduce virtual navigation markers into an Augmented Reality environment, and also to identify objects within an Augmented Reality environment that was signposted using different Virtual Spatial Markers. This tested the accuracy and repeatability of content placement of the approach, while also testing participants’ ability to reliably interpret virtual signposts within an Augmented Reality environment. Finally the Keyframe Tagging tool was tested by an expert user against a pre-existing solution to evaluate the time savings offered by this approach against the overall accuracy of content placement. Results: The average accuracy score for content placement across 20 participants was 64%, categorised as “Good” when compared with an expert benchmark result, while no tags were considered “incorrect” and only 8 from 200 tags were considered to have “Poor” accuracy, supporting the Keyframe Tagging approach. In terms of object identification from virtual cues, some of the predicted cognitive links between virtual marker property and target object did not surface, though participants reliably identified the correct objects across several trials. Conclusions: This thesis has demonstrated that accurate content delivery can be achieved through the use of a still image based reconstruction of an Augmented Reality environment. By using the Keyframe Tagging approach, content can be placed quickly and with a sufficient level of accuracy to demonstrate its utility in the scenarios outlined within this thesis. There are some observable limitations to the approach, which are discussed with the proposals for further work in this area

Towards the Biosynthesis of the Ligustrones

The synthesis of possible precursors of the ligustrone metabolites of Cercospora ligustrina was undertaken. These were postulated as hydroxy-substituted anthracenes with a fused pyrone ring. The best approach to the anthracene nucleus was via the fusion of two substituted benzenes in such a way as to produce the central ring of the anthracene. Lithiation of N,N-diethy 1-2,4-dimethoxybenzamide and reaction of the anion with 3,5-dimethoxybenzaldehyde gave a substituted phthalide. Hydrogenation cleaved the lactone ring to yield a benzylbenzoic acid which was cyclised to give 1,3,6,8-tetramethoxy-9-anthranol. 1,3,6,8,9-pentamethoxyanthracene was produced by a two stage methy-lation process from 9-acetoxy-1,3,6,8-tetramethoxyanthracene. Reaction of the lithiated amide with methyl 2,6-dimethoxy-4-formylbenzoate and reduction of the intermediate phthalide gave a carboxymethyl-substituted benzylbenzoic acid. Attempted ring closure gave 2-carboxymethyl-1,3,6,8-tetramethoxy-9,10-anthraquinone rather than the desired anthracene. Various approaches to the pyrone ring of the required precursor were also investigated. In model reactions, the best approach involved the treatment of an o-acetoxyacetophenone with base. The fungal metabolites ligustrone A and B were isolated from cultures of Cercospora ligustrina. The metabolite ligustrone C was never detected. [1-14C]Acetate feedings of C. ligustrina were investigated however incorporations were very low

ECOLOGY AND SPATIAL ANALYSIS

. Placing an ecological approach in the general framework of American geographic thought indicates the usefulness of distinguishing two trends in the development of this thought—the one ecological, the other spatial. American geography tended to reject the ecological approach because it was identified at an early period with environmental determinism. A spatial, non-functional, approach became dominant. Although the two approaches are two ends of a continuum, and thus connected, they arise from and lead to different sets of questions which involve different approaches and different bodies of theory. The ecological approach may be divided into four imprecise types—biological, human, cultural, and urban-political. The cultural-ecological approach is particularly useful in analyzing obstacles to innovation acceptance in agricultural development because it emphasizes the analysis of existent systems from different viewpoints. Four sets of reality, or viewpoints, can be distinguished in this context—that of the scientist-observer, that of the change-agent, that of the cultivator, and that of the ideal-set of the cultivator. Only when the overlaps and conflicts of these sets are recognized can a realistic appraisal be made. This is only a single instance of the potential of an ecological approach. Spatial theory and ecological theory have not yet been joined. The evident usefulness of both indicates the importance of attempting such a joining, and the futility of arguing for the ascendance of one over the other.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75164/1/j.1467-8306.1970.tb00754.x.pd

Patterns of past and recent conversion of indigenous grasslands in the South Island, New Zealand

We used recent satellite imagery to quantify the extent, type, and rate of conversion of remaining indigenous grasslands in the inland eastern South Island of New Zealand in recent years. We describe the pattern of conversion in relation to national classifications of land use capability and land environments, and ecological and administrative districts and regions. We show that although large areas of indigenous grasslands remain, grassland loss has been ongoing. Indigenous grassland was reduced in the study area by 3% (70 200 ha) between 1990 and 2008. Almost two-thirds of post-1990 conversion occurred in threatened environments with less than 30% of indigenous cover remaining, primarily in the Waitaki, Mackenzie and Central Otago administrative districts. This conversion occurred primarily on non-arable land. In the Mackenzie and Waitaki districts the rate of conversion in 2001-2008 was approximately twice that in 1990-2001. Opportunities to protect more of the full range of indigenous grasslands lie with the continuing tenure review process in these districts

The use of an electronic nose to detect early signs of soft-rot infection in potatoes

In this paper we report on the detection of soft-rot in potatoes caused by the bacterium Pectobacterium carotovorum through the use of an array of low cost gas sensors. This disease results in significant crop losses in store (circa 5%) with associated negative financial impacts. At present, there is no commercial technological solution for soft rot detection in such stores, with store managers having to regularly inspect large volumes of potatoes. As soft-rot is associated with a strong odour and there is forced air movement through potato stores, our aim was to investigate the potential of an array of low-cost gas sensors to detect the disease. In laboratory conditions, 80 potatoes with and without soft rot (evenly split) were analysed by an array of 11 different gas sensors. These were tested at both pre-symptomatic and symptomatic time points. Results indicated that 100% detection accuracy could be achieved at both time points with only 3 sensors. The identified sensors therefore offer promise for an automated in-store monitoring system