The principal objectives of this research are: to investigate the performance of different fingerprint-based WiFi Indoor Positioning Systems (IPS), analyse historical long-term data signals, detection of signal change points and outliers; then present an enhanced method that generates temporal based fingerprints. The proposed method consists of analysing signal strength profiles over time and detecting points at which the profile behaviour changes. This methodology can be used to dynamically adjust the fingerprint based on environmental factors, and with this select the relevant Wireless Access Points (WAPs) to be used for fingerprinting. The use of an Exponentially Weighted Moving Average (EWMA) Control Chart is investigated for this purpose. A long-term analysis of the WiFi scenery is presented and used as a test-bed for evaluation of state-of-the-art fingerprinting techniques. Data was collected and analysed over a period of 18 months, with over 840 different WAPs detected in over 77,000 observations covering 47 different locations of varying characteristics. A fully functional IPS has been developed and the design and implementation is described in this thesis. The system allows the scanning and recording of WiFi signals in order to define the generation of temporal fingerprints that can create radio-maps, which then allow indoor positioning to occur. This thesis presents the theory behind the concept and develops the technology to create a testable implementation. Experiments and their evaluation are also included. Based on the timestamp experiments the proposed system shows there is still room level accuracy, with a reduction in radio-map size.

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The effectiveness of location aware applications is dependent on the accuracy of the supporting positioning system. This work evaluates the accuracy of an indoors 802.11 positioning system based on signal strength fingerprinting. The system relies on an empirical survey of signal strength prior to positioning. During this survey, signal strength recordings are made at a set of positions across the environment. These recordings are used as training data for the system during positioning. In this thesis, two surveying methods, five positioning algorithms, and two spatial output averaging methods are trialled. Accuracy is determined by empirical testing in two separate environments: a 100m square domestic house and the 1,333m square third floor of the University of New South Wales Computer Science and Engineering building. In the two environments, the lowest mean distance errors are 1.25m and 2.86m respectively.

Extreme environments provide a unique source of often highly adapted and tolerant organisms. Research on organisms in these habitats has led to the discovery of novel and useful compounds and may assist in understanding the impact of global change on biodiversity. The Dry Valleys of Eastern Antarctica are vast, ice-free regions believed to be the coldest, driest desert on Earth. Despite these harsh conditions, there is an increasing amount of evidence demonstrating that the soil ecosystems of the Dry Valleys sustain a wide diversity of microorganisms. The research presented is an inter-valley comparison study which aims to scrutinize microbial communities and environmental factors driving their distribution in the Dry Valleys. Automated ribosomal intergenic spacer analysis (ARISA) was used to provide a snapshot of bacterial and cyanobacterial communities living in the mineral sands in Miers Valley, Beacon Valley, Upper Wright Valley and at Battleship Promontory. Rigorous analysis of physico-chemical differences between the soils of these four valleys was undertaken in hope to understand the environmental parameters driving the distribution and biodiversity of microbial communities present. Multivariate statistical analysis and ordination of ARISA and physico-chemical data revealed that bacterial communities from each valley form distinctive clusters. Conversely, cyanobacterial communities showed less diversity and a more even distribution between valleys.

Specialists are expecting the knowledge of location will trigger yet another revolution in mobile services. Location-base services (LBS) have attracted many researchers and enterprises and one of the key aspects of LBS is positioning technology. Considering a wider and more complex field - ubiquitous computing, location is the fundamental element. This work focuses on some aspects of the new techniques of terrestrial positioning systems. Wireless LAN is one of the most popular systems used for positioning for indoor environments and public places. We have investigated the trilateration and fingerprinting approaches and the results showed the advantages of fingerprinting. A novel method to generate the fingerprints database based on Universal Kriging (UK) was developed, which can not only significantly decrease the training time, but also increase the accuracy of estimates. In mobile phone positioning systems, most techniques suffer from the non-line-of-sight (NLOS) propagation. We investigated the specifics of NLOS error, and proposed a method to mitigate the errors. Furthermore, a new algorithm named WSMM (wireless signal map matching) was discussed. Simulations and experiments verified the idea, and the accuracy of positioning can be improved greatly. Since fingerprinting technique can utilize rather than suffer from the NLOS propagation, it was also applied in mobile phone positioning system. Experiments showed both the deterministic approach and probabilistic approach can provide better results comparing with other techniques in suburban area. To achieve a robust positioning system and provide more useful information of the user, multisensor combination and data fusion are necessary. As the first step of future research, a mulitsensor synchronization system was developed. This system can promisingly achieve synchronization with error less than 0.4 ms, which is suitable for most land applications. Hence the main findings of this thesis are: (1) a novel method of yielding fingerprint database for both wireless LAN (WLAN) and mobile phone systems when using the fingerprinting technique for positioning; (2) a database method to mitigate NLOS error for mobile phone positioning systems; (3) a low cost synchronization system for integration of multiple sensors.

Given that morphological identification of willow is difficult, willow lines being investigated for their suitability for use as short rotation crops for biomass production in Saskatchewan were investigated with various molecular techniques as possible tools for DNA fingerprinting. Flow cytometry was used to assess variation in nuclear DNA content and thus ploidy level of the lines of the five species (<i>Salix purpurea, Salix eriocephala, Salix sachalinensis, and Salix dasyclados</i>) and three hybrids (<i>S. purpurea x S. miyabeana, S. sachalinensis x S. miyabeana, S. viminalis x S. miyabeana</i>). The DNA content varied between 1.14 and 3.00pg. Ploidy levels of the species varied from triploid to hexaploid while all hybrids were tetraploid. RAPD and ISSR marker systems were used to assess genetic and taxonomic relationships among all willow lines. Of 90 RAPD primers tested, 60 were selected and 99 polymorphic bands scored. Of 35 ISSR primers tested, 19 were selected and 35 polymorphic bands scored. Both RAPD and ISSR dendrograms clustered together lines belonging to the same species and same hybrid combination. A combination of strong and reproducible RAPD and ISSR bands was used to develop identification keys for lines belonging to the same species.<p> The ribosomal RNA gene region, including the entire 5.8S RNA gene and the internal transcribed spacers (ITS1 and ITS2) was amplified and sequenced to assess sequence homology between the five species. The total length of the amplified region was 601bp, with the ITS1, 5.8 S and ITS2 being 223, 163, and 215bp respectively. Intra- and inter-species SNPs were observed, 6 within ITS1, and 3 within ITS2. No polymorphisms were found in the 5.8S gene. The low rate of variation within the sequenced ITS fragment between species supports the monophyly of the five species involved in this study, and confirms their belonging to the subgenus Caprisalix. SCAR primers were designed from species-specific polymorphic nucleotides and applied to the willow collection to test their use for species identification. A species identification key based on SNPs is proposed.

Given that morphological identification of willow is difficult, willow lines being investigated for their suitability for use as short rotation crops for biomass production in Saskatchewan were investigated with various molecular techniques as possible tools for DNA fingerprinting. Flow cytometry was used to assess variation in nuclear DNA content and thus ploidy level of the lines of the five species (<i>Salix purpurea, Salix eriocephala, Salix sachalinensis, and Salix dasyclados</i>) and three hybrids (<i>S. purpurea x S. miyabeana, S. sachalinensis x S. miyabeana, S. viminalis x S. miyabeana</i>). The DNA content varied between 1.14 and 3.00pg. Ploidy levels of the species varied from triploid to hexaploid while all hybrids were tetraploid. RAPD and ISSR marker systems were used to assess genetic and taxonomic relationships among all willow lines. Of 90 RAPD primers tested, 60 were selected and 99 polymorphic bands scored. Of 35 ISSR primers tested, 19 were selected and 35 polymorphic bands scored. Both RAPD and ISSR dendrograms clustered together lines belonging to the same species and same hybrid combination. A combination of strong and reproducible RAPD and ISSR bands was used to develop identification keys for lines belonging to the same species.<p> The ribosomal RNA gene region, including the entire 5.8S RNA gene and the internal transcribed spacers (ITS1 and ITS2) was amplified and sequenced to assess sequence homology between the five species. The total length of the amplified region was 601bp, with the ITS1, 5.8 S and ITS2 being 223, 163, and 215bp respectively. Intra- and inter-species SNPs were observed, 6 within ITS1, and 3 within ITS2. No polymorphisms were found in the 5.8S gene. The low rate of variation within the sequenced ITS fragment between species supports the monophyly of the five species involved in this study, and confirms their belonging to the subgenus Caprisalix. SCAR primers were designed from species-specific polymorphic nucleotides and applied to the willow collection to test their use for species identification. A species identification key based on SNPs is proposed.

Previous studies examining the canine intestinal microflora have focused on cultivation of bacteria from intestinal content. Recently, it has been recognized that the majority of bacteria cannot be identified using standard culture techniques. The aim of this study was to describe the composition and dynamics of the canine intestinal microflora using molecular methods based on identification of the 16S ribosomal DNA (16S rDNA) and to evaluate the clinical use of a 13C-glycocholic acid blood test (13CGCBT) as a serum marker for small intestinal bacterial biomass. Intestinal content was obtained from healthy dogs and the microflora was characterized in different compartments of each dog by denaturing gradient gel electrophoresis (DGGE) and comparative 16S rDNA analysis. A 13C-glycocholic acid blood test (13C-GCBT) was developed as a marker for small intestinal bacterial biomass and the influence of tylosin administration on the 13C-GCBT, serum concentrations of cobalamin, folate, and unconjugated cholic acid (SUCA) was evaluated. There was marked variation in DGGE profiles between individual dogs and also between different intestinal compartments within dogs. DGGE profiles from duodenal juice samples collected endoscopically at different time-points varied within individuals, possibly due to variations over time or a slight variation in sampling location. Direct sequencing revealed 106 individual 16S rDNA sequences. Forty-two sequences showed less than 98% similarity to described sequences in public databases and may constitute previously uncharacterized bacterial species. Serum folate concentrations, SUCA, and the cumulative percent dose/min of 13C administered as 13C-glycocholic acid (CUMPCD) increased significantly following tylosin administration (p<0.01). The results indicate that dogs have a complex intestinal microflora with marked differences between individual dogs. Different intestinal compartments appear to host a unique microflora and the assessment of a fecal sample does not yield accurate information about the composition of the microflora in proximal compartments of the gut. The intestine harbors many previously uncharacterized bacterial species. The clinical significance of these uncharacterized intestinal bacterial species needs to be further investigated in dogs with gastrointestinal disease. Increased serum folate, SUCA, and CUMPCD in the 13C-GCBT suggest that, in the dogs described here, tylosin administration increased the biomass of organisms carrying out these metabolic functions.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003. / Includes bibliographical references (leaves 103-111). Also available in electronic version. Access restricted to campus users.