This thesis is broadly concerned with the representation of the environment of a mobile robot and the modelling of its motion. An attempt has been made to address some issues of the laser scan matching for global self-localization and map building. Different methods for the interpretation of sensor information have been investigated. Mobile robots have many applications in transportation, surveillance, health care and mining etc. For a successful navigation, the representation of the environment is crucial. The robot environment interaction is very complex in practice. Many factors contribute to this complexity, such as the electromechanical hardware structure and complex controlling and navigational programming modules. Above all however, it is the environment itself which is usually very complex. The perception model is the most important component of the navigation system of a mobile robot, at the core of which is the representation of the environment. Environment parameters are difficult to model and simplistic models are used in various position estimation techniques. However, for true autonomous navigation, the environment should be represented in a more dense fashion and the interpretation should be straightforward. The robot interacts with its environment using sensors. The sensory information provides clues about the location of the robot but the interpretion of this information is very challenging. Some type of model or a mathematical description of the environment is required for any meaningful interpretation and for making critical navigational decisions when a new observation arrives. The second key component of a navigation system is a motion model. Due to structural and software complexity the behaviour of a robot is rarely repeatable under the same motion commands. This can be attributed to many factors such as slippage, wear and tear of wheels at different rates, floor conditions or obstacle negotiation strategies. This means that motion commands have an associated uncertainty and need statistical treatment. Similarly the processing of raw laser data, although highly desirable, is computationally very expensive and therefore we usually need to make a trade off and extract some features from this data, despite losing some of the information. In this thesis we investigated three core issues of motion modelling, perception (or observation) modelling and scan correlation. Some auxiliary issues have also been addressed, such as the extraction of features from laser data and a broader classification of the environment suitable for certain situations. In regard to environment representation, we used the geometrical form of representation and tried to extract some statistical formulation. This method suggests to capture the environment model in a statistical form before the start of navigation when the map is known. The detailed parametric representation of the environment is obtained along with a proposal for a laser scan matching method based on geometrical line and corner features. The geometrical representation is based on some features extracted from raw laser data. This is considered a compact and easily implementable form, which was one of the objectives of our research, however utilisation of all the sensory information is still desirable and we have also investigated this issue. The models have been tested thoroughly on simulations and with real data in laboratory and office-like indoor environments. Laser scan matching is a technique of position estimation based on matching two laser scans taken at the initial and final positions of the robot. We also presented a method to find out the degree of match between two laser scans. At the end of the thesis, the scan correlation has been used to find the most reliable landmarks in the environment. This approach filters out the nuisance landmarks which increase the size of matrices in Simultaneous Localization and Mapping algorithms. An improved computational efficiency was of primary concern and a main focus of this research. All the methods proposed in this thesis, such as feature extraction, broader classification, parametric formulation, line segment based scan matching and the scan matching for measurement updates address the computational issues in a fundamental way by using an appropriate formulation of the problem.

Folate is an important B vitamin in the daily diet. It is not known to what extent naturally occurring folates in the mixed diet is bioavailable. Knowledge on to what extent the natural folates are absorbed would be best studied in a population that is not exposed to any folate fortificant. The aim of the present study was to study the bioavailability of dietary 5-methyl tetrahydrofolate (5-MTHF) in a whole day??s mixed diet relative to supplemental 5-MTHF in a selected Indian population. A dietary survey (n=200) conducted in South India, revealed a mean total intake of folate of 277+ 92.3 μg/day (which is nearly 3 times higher than the current Indian Recommended Dietary Intake set to 100 μg/day) based on the actual analysis of foods collected from a typical diet using a trienzyme technique followed by the microbiological assay. Further, the individual folate forms present in the foods were also analysed using a newly developed Liquid Chromatography Tandem Mass Spectrometry LC-MS/MS). Quantification of folates was performed using internal standards. Good linearity was observed between 2-100 ng/Injection (Injection volume-100 μL, R2: 0.98) that was suitable for analysis of foods (cereal, pulse, vegetables, milk based preparations and fruit) and blood samples (serum folate and erythrocyte folate) for use in bioavailability study. The folate intakes were reported to be higher (429+ 68.7 μg/day) when the individual foods from the diet were analysed using the LC-MS/MS technique when compared to the values generated using microbiological assay. LC-MS/MS analysis revealed that the Indian diets were predominant in 5-MTHF and the important sources being cereals, pulses and vegetables. 22 human volunteers, aged 18-25 years were recruited in India to study the bioavailability of 5-MTHF. A randomized trial (12 weeks) was designed, where the subjects consumed 400 g 5-MTHF/day in the form of as supplemental drink or an experimental diet (400 g/day) consisting predominantly 5-MTHF (90%). Relative bioavailability of 5-MTHF was calculated by comparing the responses to food folate in relation to supplemental 5-MTHF, as indicated by the biomarkers. The relative bioavailability of food folate predominant in 5-MTHF was 41% based on serum folate indicator and 47% based on erythrocyte folate status. A mean increase of 60% was observed in the erythrocyte folate levels of the subjects consuming diets predominant in 5-MTHF in 12 weeks. Diets predominant in 5-MTHF have a good potential in improving the folate status of the population.

The Transplanted Bush: Dislocation, Desire and the Domestic takes as its theme the idea of the Australian bush and seeks new ways to represent it within the traditions of Australian figurative landscape painting. The research identifies ways to disrupt the bush brand, a paradigm that has played a significant and romantic role in the construction of Australian national identity, as a rallying point for nationalist sentiment and to sell Australia to the world as a unique tourist destination. The bush, as a space that is anti-city, an idea that generally relies on a British genealogy, and one that is constructed according to hetero-normative strategies, is significant in the creation of Australian identity because it is widely regarded as the real Australia. Real in this context has somehow become distorted to mean those parts of our nation that make us distinct from the rest of the world, while continuing to reflect the values and aspirations of a dominant culture and its heroic history of colonising and domesticating a strange land. The overriding focus of this investigation has been to determine to what extent it is possible to reconceptualize the bush brand so that it can accommodate new themes of identity, particularly in relation to gender and sexuality. This research adopts the position that the bush is an idea that has relied heavily upon myths, legends and mono-cultural perspectives for its construction and, as a result, is open to negotiation. Consequently, this investigation takes place at the very heart of the bush paradigm, within its grand master narratives, by engaging with its symbols and signifiers. It reviews the ideological and representational role played by the traditional model of Australian figurative landscape painting, and considered how it can be reinvested with new signs, symbols, motifs, colours and ideas. By developing and introducing a new vocabulary of signs and symbols that erodes the distinctions between the bush, the urban and the domestic, this research disrupts the internal logic and coherence of the bush brand.

This study investigated the distribution of bibliographic records amongst online bibliographic databases. The topic of Fuzzy Set Theory over the period of 1965 to 1993 was chosen to provide the case study for this investigation. From the DIALOG database host, searches were conducted on 114 databases to determine the number of journal article records relating to the topic of Fuzzy Sets. Both the number of records in each database, as well as the overlap of coverage between the databases were calculated. Six counting techniques were developed to allocate records to databases based on different methods for handling records that were duplicated between databases. When duplicate records are included, the top database accounts for 19% of the records; when duplicates are removed, the top database was found to account for 37% of the records. The distribution of records in databases was found to conform to the Bradford-Zipf hyperbolic distribution. Various other analyses were undertaken including: the duplicate records themselves, the total size of the DIALOG database system over time and the density of Fuzzy Set records in databases over time. A secondary aim of this study was to perform an informetric study on the literature of Fuzzy Set Theory itself. Results obtained include an analysis of the growth of the Fuzzy Set literature, an analysis of the journals covering the topic of Fuzzy Sets, an analysis of the terminology used in describing topics related to Fuzzy Sets. Also, the Ulrich's database was used to provide a subject classification of the journals to analyse the diffusion of the topic of Fuzzy Sets into other disciplines. Apart from the discipline of mathematics, the top disciplines into which Fuzzy Sets have diffused were found to be applied physics, systems and computing. The third aim of the thesis was to refine and develop the methodology used to perform large scale informetric studies using data from a variety of online bibliographic databases. Commercially available software was used wherever possible, but where this was not possible or infeasible, custom written programs were developed to perform various steps in the methodology.

Do western management practices and beliefs and Chinese business practices complement or substitute each other in the emerging world of Chinese business? This thesis explores the interaction between two central ideas in western and Chinese thinking about the way business should be done ??? between the western emphasis on market orientation as the key to profitable growth, and the Chinese reliance on traditional networks embodied in the concept of guanxi. These two variables are embedded in a broader model of strategic decision making in order to identify moderating factors that may influence performance outcomes. Following pretests and in-depth interviews, in 2003 a sample of 152 businesses was drawn in Shanghai, Jiangsu and Zhejiang area from two industries, the electronics industry and the textile/garment industry. Low response rates and a small sample were two important limiting factors. Two broad analytical approaches were used. The first made use of graphical smoothing methodology, an approach that facilitates the identification of complex non-linear interactions among the variables. The second used Structural Equation Modelling (SEM) where a linear structure is imposed on the relationships among the variables, allowing simultaneous consideration of the full variable set together with an analysis of fit and measurement error, while the graphical smoothing non-linear method was effectively limited to three variables at a time. The graphical analysis suggested the existence of nonlinearities in many relationships, and found a positive interaction between guanxi and market orientation in influencing performance, and that both were in that sense complements rather than substitutes. The SEM analysis suggested that while there were some indirect links between guanxi, market orientation and performance, these were relatively weak, (although the use of guanxi with other managers was a factor in market orientation), and that the primary driver of performance was the strength of the competitive advantage possessed by the firm. This factor directly impacted market orientation, indirectly affected guanxi and accounted for much of the observed correlation between the two cultural variables, guanxi and market orientation, and performance.

From a regulatory point of view, the main objective of acute toxicity testing is to classify chemicals according to their intrinsic toxicity. This is conventionally conducted on the basis of the animal LD50 methods however, this test has been widely criticised. Moreover, conventional toxicity testing focuses on single chemicals and often human exposures are to more than one chemical. This research study had two main objectives. The first was to investigate the accuracy of selected in vitro tests for predicting the acute toxic action of chemicals in rodents and humans, and in predicting the Globally Harmonised System of Classification and Labelling of Chemicals (GHS) categories. The second was to explore the relevance of in vitro tests in determining the nature of toxicological interactions (i.e. additive, antagonistic and synergistic) among binary and ternary chemical mixtures. A battery of cytotoxicity tests (MTS, NRU, LDH and ATP) assays were used to determine the toxicity of 21 chemicals spread across the GHS categories where mercuric chloride (GHS category 1) was the most toxic chemical and glycerol (GHS unclassified) the least toxic. Significant differences for the majority of test chemicals were found among all assays, highlighting the need for a battery of in vitro tests measuring different endpoints. The NRU assay was found to be a more sensitive measure of toxicity for most chemicals and predicted all of the GHS categories. In general, in vitro IC50 values correlated well with in vivo rodent (LD50); human acute toxicity (LDL0 and LC) data and published in vitro data. In addition, in vitro NOEC values correlated well with published TLV. Selected assays (MTS, NRU) were applied to binary (15) and ternary (5) chemical mixtures. Mixtures were prepared at mixture ratios proportional to the potency of individual components. Experimental data was used to assess the predictive capabilities of two approaches (mathematical model and concentration addition) commonly used by regulatory agencies which assume additive effect. However, all three interactions (antagonism, synergism and additivity) where observed in this study. These results suggest that these interactions cannot be excluded from toxicological risk assessments. The methods developed and information obtained from this study provide a comprehensive comparison between selected in vitro assays for assessing the toxicity of chemicals and their mixtures.

Successful implementation of any technology requires acceptance by the users. Numerous studies in the area of information technology acceptance, based on wellknown theories have been conducted to examine technology acceptance models and predict user adoption/acceptance behaviour. There are several studies dealing with patients??? acceptance of different telemedicine applications, but few about the patients??? acceptance of home telecare. Most existing studies are not based on a strong theoretical framework. In this study, based on an extensive literature review and preliminary qualitative data, a theoretical model of the effect of Home Telecare Management System (HTMS) characteristics and psychological variables associated with technophobia on patients??? acceptance of HTMS is proposed. The proposed model is an augmented Technology Acceptance Model (TAM) of Davis (1986), which is called Home Telecare Management System acceptance model (HTMS-AM), in which TAM has been augmented by two constructs: HTMS anxiety and HTMS self-efficacy. The model is proposed to improve our understanding regarding patients??? acceptance of HTMS, which may lead to successful design and implementation of home telecare systems. In addition, it can be used as a theoretical basis to evaluate new generations of HTMS in terms of users acceptance in the early stage of their design and development even prior to implementation. In order to test the reliability and validity of the measures, video demonstrations of a home telecare system and demonstration of a system prototype to potential users was employed. To propose the HTMS-AM the following five stages were taken: 1. General well-known theoretical models of human behaviour from psychology and technology acceptance models from information technology were reviewed to create a basic template for the proposed model. 2. A preliminary study (focus group interviews, Chapter 5) was conducted to assess patients??? perceptions of HTMS. 3. Based on an extensive literature review and findings from preliminary qualitative studies, HTMS acceptance model was proposed, to improve our understanding about factors, which may affect patients??? intention to use HTMS. Several adaptations were applied in the model to be applicable in the HTMS context, such as augmenting the model with HTMS self-efficacy and HTMS anxiety constructs. 4. To measure the different psychological variables in the proposed model, valid and reliable measures from previous studies were used. However the preliminary study was used to develop measures, which did not exist in the literature. 5. These measures were tested in the final study. The subjects were patients who had been affected with Congestive Heart Failure (CHF) and/or Chronic Obstructive Lung Disease (COPD). Given the chronic nature of these diseases, the necessity for extended monitoring and management and frequent admission to hospitals due to worsening health status, these patients were deemed the most appropriate candidates for the HTMS. Further studies with more cases need to be conducted to test the actual model in which the impact of HTMS characteristics, psychological and demographic factors associated with technophobia upon intention to use the HTMS and the correlation of these factors with each other in appropriate healthcare settings.

The combustion efficiency of pulverised coal injection PCI is an important factor influencing stability and productivity of the blast furnace. It is affected by coal properties and the process conditions employed for combustion. Economic considerations have driven blast furnace operators to commission a wide range of coals, which differ in type and rank. The main objective of the current project is to study the influence of different operating conditions on combustion performance of coal and to examine the role of coal minerals and their transformations on low and high temperature reactivity. The combustion performance of three PCI coals was investigated under a range of combustion conditions including three combustion temperatures of 900??C, 1200??C and 1500??C, and a range of oxygen concentrations in the gas phase at 1200??C in a drop tube furnace (DTF). The low temperature oxygen reactivity of pyrolysed chars was also measured by observing weight loss in a thermogravimetric (TGA) furnace at 600??C. Physical and chemical properties of pyrolysed and partially combusted chars were characterised using a range of analytical tools including X-ray diffraction, scanning electron microscopy, BET N2 surface area and Hg porosity. The correlation between char properties and char reactivity at low and high temperatures was also investigated. All three coal samples experienced deactivation during progressive combustion at 1200??C and 23%v O2 i.e. there was a decrease in the reaction rate with proceeding combustion. The carbon structure of the chars became increasingly ordered as quantified by an increase in crystallite height and a decrease in the amorphous carbon proportion in char. Partially combusted char had much higher surface area than a pyrolysed one, which can be attributed to the opening of enormous number of closed pores as combustion proceeds. However, this increase in surface area did not show a direct correlation with char reactivity. Average particle size of ash increased with increasing degree of combustion due to fusion and agglomeration of coal minerals. Under these conditions, carbon structural ordering of char was found to be one of the key factors primarily responsible for loss of char reactivity during combustion. Increasing oxygen content in the gas stream from 23% to 35% at 1200??C resulted in a significant improvement in the combustion performance of three coals, with burnout increasing from ~65% to up more than ~95%. However, increasing oxygen level beyond 35% did not lead to any further significant improvements. Coal burnout was also enhanced by increasing temperature in the range 900??C to 1500??C, such that the improvement was much more rapid in the higher temperature range of 1200??C to 1500??C. This could be related to increased reaction rates at higher temperatures. Pyrolysed char reactivity was measured at low temperature 600??C and 10%v O2 using TGA. The results indicated that the presence of iron and calcium minerals could result in enhanced char reactivity. Coal minerals underwent increased fusion and melting as the combustion temperature was increased. At 1500??C, most ash particles were molten. The level of basic oxides in ash as well as the extent of association between aluminosilicates and basic oxides enhanced the proportion of molten phases. Fusing and melting behaviour of ash particles was found to influence char combustion reactivity at high temperatures. Ash melting on the char surface may hinder gas accessibility to the reactive surface of char, thereby decreasing char burnout. The molten ash particles may coalesce and cover char surface or these molten particles may partially/completely block char pores. The amount of slag phases in ash and the distribution of minerals in char are expected to have a significant influence on ash-char interactions at high temperatures. In summary, the study shows that inorganic matter present in coal can affect coal combustion in a number of ways. Inorganic minerals, such as iron and calcium catalyse char oxidation at low temperatures. On the other hand, these minerals may act as fluxing agents at high temperatures, which could lower the melting point of aluminosilicates minerals in char. The molten phases of ash may restrict the accessibility of oxygen to carbon in char through physical obstruction, thereby, retard char oxidation.

Sol-gel matrices may be used to immobilise enzymes, facilitating retention of the catalyst while allowing a flow of substrates and products through the matrix. Candida antarctica lipase B (CALB), a commonly used industrial enzyme, has been shown to have a prolonged catalytic life and enhanced activity when encapsulated in these sol-gel materials. However, the molecular basis for this effect had yet to be elucidated. This study investigated the effect of encapsulating CALB in sol-gel matrices by comparison of CALB in solution with its encapsulated form. Use of complementary techniques revealed the presence of complex interactions between the enzyme and the evolving sol-gel material. 29Si Nuclear Magnetic Resonance (NMR) measurements demonstrated that CALB influenced sol-gel structure by altering silica speciation. Inclusion of CALB also altered the mesoporosity of the matrices as determined using nitrogen sorption and electron microscopy. Correlation of activity assays with 29Si speciation changes indicated that the catalytic activity of the enzyme in solution was directly involved in sol-gel hydrolysis and condensation reactions. Increased specific activity of CALB in the sol-gel aqueous precursor solution resulted in measurable changes in the gel structure of matrices containing 3.1mg of CALB/ml of gel. Small angle neutron scattering (SANS) was used to examine the structure of CALB in solution. The influence of the sol-gel reactants glycerol, sodium fluoride and isopropanol upon the radius of gyration of CALB in solution was determined. SANS was also employed in an investigation of encapsulated CALB molecules which utilised contrast matching of the sol-gel matrix. However, contrast variation studies found that the match point for the silica matrix, both with and without enzyme present, was lower than predicted (~35% vol% D2O). Consequently, the contrast match point of the protein was close to that of the encapsulating material. Scattering from the encapsulated protein at this point was therefore minimal; it is clear that the contrast match point of the protein should be moved through in vivo deuteration in future experiments of this type. These investigations advance the understanding of interactions between the matrix and the encapsulated enzyme in sol-gel biomaterials.

Sol-gel matrices may be used to immobilise enzymes, facilitating retention of the catalyst while allowing a flow of substrates and products through the matrix. Candida antarctica lipase B (CALB), a commonly used industrial enzyme, has been shown to have a prolonged catalytic life and enhanced activity when encapsulated in these sol-gel materials. However, the molecular basis for this effect had yet to be elucidated. This study investigated the effect of encapsulating CALB in sol-gel matrices by comparison of CALB in solution with its encapsulated form. Use of complementary techniques revealed the presence of complex interactions between the enzyme and the evolving sol-gel material. 29Si Nuclear Magnetic Resonance (NMR) measurements demonstrated that CALB influenced sol-gel structure by altering silica speciation. Inclusion of CALB also altered the mesoporosity of the matrices as determined using nitrogen sorption and electron microscopy. Correlation of activity assays with 29Si speciation changes indicated that the catalytic activity of the enzyme in solution was directly involved in sol-gel hydrolysis and condensation reactions. Increased specific activity of CALB in the sol-gel aqueous precursor solution resulted in measurable changes in the gel structure of matrices containing 3.1mg of CALB/ml of gel. Small angle neutron scattering (SANS) was used to examine the structure of CALB in solution. The influence of the sol-gel reactants glycerol, sodium fluoride and isopropanol upon the radius of gyration of CALB in solution was determined. SANS was also employed in an investigation of encapsulated CALB molecules which utilised contrast matching of the sol-gel matrix. However, contrast variation studies found that the match point for the silica matrix, both with and without enzyme present, was lower than predicted (~35% vol% D2O). Consequently, the contrast match point of the protein was close to that of the encapsulating material. Scattering from the encapsulated protein at this point was therefore minimal; it is clear that the contrast match point of the protein should be moved through in vivo deuteration in future experiments of this type. These investigations advance the understanding of interactions between the matrix and the encapsulated enzyme in sol-gel biomaterials.