736 resultados para CONSTRUCT
Resumo:
Better management of knowledge assets has the potential to improve business processes and increase productivity. This fact has led to considerable interest in recent years in the knowledge management (KM) phenomenon, and in the main dimensions that can impact on its application in construction. However, a lack of a systematic way of assessing KM initia-tives’ contribution towards achieving organisational business objectives is evident. This paper describes the first stage of a research project intended to develop, and empirically test, a KM input-process-output framework comprising unique and well-defined theoretical constructs representing the KM process and its internal and external determinants in the context of con-struction. The paper presents the underlying principles used in operationally defining each construct through the use of extant KM literature. The KM process itself is explicitly mod-elled via a number of clearly articulated phases that ultimately lead to knowledge utilisation and capitalisation, which in turn adds value or otherwise to meeting defined business objec-tives. The main objective of the model is to reduce the impact of subjectivity in assessing the contribution made by KM practices and initiatives toward achieving performance improvements.
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Knowledge management (KM) continues to receive mounting interest within the construction industry due to its potential to offer solutions for organisations seeking competitive advantage. This paper presents a KM input-process-output conceptual model comprising unique and well-defined theoretical constructs representing KM practices and their internal and external determinants in the context of construction. The paper also presents the underlying principles used in operationally defining each construct using extant KM literature, and offers a number of testable hypotheses that capture the inter-relationships between the identified constructs.
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The construction of menopause as a long-term risk to health and the adoption of discourses of prevention has made necessary a decision by women about medical treatment; specifically regarding the use of hormone replacement therapy. In a study of general practitioners’ accounts of menopause and treatment in Australia, women's ‘choice’, ‘informed decision-making’ and ‘empowerment’ were key themes through which primary medical care for women at menopause was presented. These accounts create a position for women defined by the concept of individual choice and an ethic of autonomy. These data are a basis for theorising more generally in this paper. We critically examine the construct of ‘informed decision-making’ in relation to several approaches to ethics including bioethics and a range of feminist ethics. We identify the intensification of power relations produced by an ethic of autonomy and discuss the ways these considerations inform a feminist ethics of decision-making by women. We argue that an ‘ethic of autonomy’ and an ‘offer of choice’ in relation to health care for women at menopause, far from being emancipatory, serves to intensify power relations. The dichotomy of choice, to take or not to take hormone replacement therapy, is required to be a choice and is embedded in relations of power and bioethical discourse that construct meanings about what constitutes decision-making at menopause. The deployment of the principle of autonomy in medical practice limits decision-making by women precisely because it is detached from the construction of meaning and the self and makes invisible the relations of power of which it is a part.
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Over the past two decades medical researchers and modernist feminist researchers have contested the meaning of menopause. In this article we examine various meanings of menopause in major medical and feminist literature and the construction of menopause in a semi-structured interview study of general practitioners in rural South Australia. Three discursive themes are identified in these interviews; (i) the hormonal menopause – symptoms, risk, prevention; (ii) the informed menopausal woman; and (iii) decision-making and hormone replacement therapy. By using the discourse of prevention, general practitioners construct menopause in relation to women's health care choices, empowerment and autonomy. We argue that the ways in which these concepts are deployed by general practitioners in this study produces and constrains the options available to women. The implications of these general practitioner accounts are discussed in relation to the proposition that medical and feminist descriptions of menopause posit alternative but equally-fixed truths about menopause and their relationship with the range of responses available to women at menopause. Social and cultural explanations of disease causality (c.f.Germov 1998, Hardey 1998) are absent from the new menopause despite their being an integral part of the framework of the women's health movement and health promotion drawn on by these general practitioners. Further, the shift of responsibility for health to the individual woman reinforces practice claims to empower women, but oversimplifies power relations and constructs menopause as a site of self-surveillance. The use of concepts from the women's health movement and health promotion have nevertheless created change in both the positioning of women as having ‘choices’ and the positioning of some general practitioners in terms of greater information provision to women and an attention to the woman's autonomy. In conclusion, we propose that a new menopause has evolved from a discursive shift in medicine and that there exists within this new configuration, claiming the empowerment of women as an integral part of health care for menopause, the possibility for change in medical practice which will broaden, strengthen, and maintain this position.
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Environmental education centres contribute to schools and communities in Environmental Education and Education for Sustainability through nature and urban -based, experiential learning and action learning approaches. An underlying assumption of these centres is that intensive, short-term, outdoor/environmental education experiences can change key attitudes and/or actions leading to positive environmental behaviour. This study reflects the interests of a researching professional who investigated aspects of a program that he designed and implemented as principal of an environmental education centre. Most evaluations of similar programs have used quasi-experimental designs to measure the program outcomes. However, this study considered the experiences of the program from the perspectives of a group of key stakeholders often overlooked in the literature; the children who participated in the program. This study examined children’s accounts of their own experiences in order to contribute new understandings of children’s perspectives and how they can be considered when designing and implementing environmental education programs. This research drew on key theoretical assumptions derived from the sociology of childhood. Within sociology of childhood, children are considered to be competent practitioners within their social worlds, who, through their talk and interaction, participate actively in the construction of their own social situations. This approach also views children as capable and competent learners who construct their knowledge through everyday participation in social experiences. This study set out to generate children’s own accounts of their experiences of a five day residential program at the Centre. In total, 54 children participated in the study that used a multi-faceted data collection approach that included conversations, drawings, photographs and journal writing. Using content analysis, data were analysed by means of an inductive approach to develop themes related to the children’s perspectives of their experiences. Three interrelated and co-dependent components of the experience emerged from the analysis; space and place; engagement and participation; and responsiveness and reflection. These components co-exist and construct the conditions for effective experiences in environmental education at the Centre. The first key finding was the emphasis that the children placed on being provided with somewhere where they could feel safe and comfortable to interact with their environment and engage in a range of outdoor experiences. The children identified that place was an outdoor classroom where they could participate in first-hand experiences and, at times, explore out-of-bound spaces; that is, a place where they had previously been limited, often by adults, in their opportunities to interact with nature. A second key finding was the emphasis that the children placed on engagement and participation in environmental experience. The children described participating in a range of new primary experiences that involved first-hand, experiences and also described participating in collaborative experiences that involved interacting with peers and with teachers, who appeared to behave differently to how they behaved at school. Finally, the children described a different type of interactional relationship with teachers, comparing the active educational role they played on camp to a more passive role at school where they sat at a table and the teacher wrote on the board. The final key finding was the emphasis that the children placed on responsiveness and reflection in the experience. In responding to their experiences, the children described the fun and excitement, confidence and satisfaction that they gained from the experience. The children also identified how their experiences contributed to the development of a caring-for-nature attitude and the value of a disorienting dilemma in promoting responsiveness to the environment. This disorienting dilemma was an event that caused the children to reassess their own beliefs and attitudes. From the three main findings, a theoretical framework that represented the children’s accounts of their experiences and a pedagogic approach that respected their accounts was developed. This pedagogic approach showed how a disorienting dilemma could create a disequilibrium in relation to a child’s existing ideas and experiences. As a result, children were challenged to reflect upon their existing environmental beliefs and practices. The findings of this research have implications for the field of environmental education. Adopting sociology of childhood provides an alternative foundation to research and can present a deeper understanding of what children believe, than an approach that relies solely on using scientific methods to undercover and analyse these understandings. This research demonstrates the value of gaining children’s accounts to assist educators to design environmental education programs as it can offer more than adult and educator perspectives. This study also provides understandings of environmental education practice by describing how the children engaged with informal learning situations. Finally, two sets of recommendations, drawn from this study, are made. The first set considers nine recommendations about and for future research and the second relates to redesigning of the environmental educational program at the research site, with six recommendations made.
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Background: Postoperative nausea and vomiting is one of the most common adverse reactions to surgery and all types of anaesthesia and despite the wide variety of available antiemetic and anti-nausea treatments, 20-30% of all patients still suffer moderate to severe nausea and vomiting following general anaesthesia. While aromatherapy is well-known and is used personally by nurses, it is less well utilised in the healthcare setting. If aromatherapy is to become an accepted adjunct treatment for postoperative nausea and vomiting, it is imperative that there is both an evidence base to support the use of aromatherapy, and a nursing workforce prepared to utilise it. Methods: This involved a Cochrane Systematic Review, a Delphi process to modify an existing tool to assess beliefs about aromatherapy to make it more relevant to nursing and midwifery practice, and a survey to test the modified tool in a population of nurses and midwives. Findings: The systematic review found that aromatherapy with isopropyl alcohol was more effective than placebo for reducing the number of doses of rescue antiemetics required but not more effective than standard antiemetic drugs. The Delphi panel process showed that the original Beliefs About Aromatherapy Scale was not completely relevant to nursing and midwifery practice. The modified Nurses' Beliefs About Aromatherapy Scale was found to be valid and reliable to measure nurses' and midwives' beliefs about aromatherapy. Factor analysis supported the construct validity of the scale by finding two sub-scales measuring beliefs about the 'usefulness of aromatherapy' and the 'scientific basis of aromatherapy'. Survey respondents were found to have generally positive beliefs about aromatherapy, with more strongly positive beliefs on the 'usefulness of aromatherapy' sub-scale. Conclusions: From the evidence of the systematic review, the use of isopropyl alcohol vapour inhalation as an adjunct therapy for postoperative nausea and vomiting is unlikely to be harmful and may reduce nausea for some adult patients. It may provide a useful therapeutic option, particularly when the alternative is no treatment at all. Given the moderately positive beliefs expressed by nurses and midwives particularly about the usefulness of aromatherapy there is potential for this therapy to be implemented and used to improve patient care.
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In the modern built environment, building construction and demolition consume a large amount of energy and emits greenhouse gasses due to widely used conventional construction materials such as reinforced and composite concrete. These materials consume high amount of natural resources and possess high embodied energy. More energy is required to recycle or reuse such materials at the cessation of use. Therefore, it is very important to use recyclable or reusable new materials in building construction in order to conserve natural resources and reduce the energy and emissions associated with conventional materials. Advancements in materials technology have resulted in the introduction of new composite and hybrid materials in infrastructure construction as alternatives to the conventional materials. This research project has developed a lightweight and prefabricatable Hybrid Composite Floor Plate System (HCFPS) as an alternative to conventional floor system, with desirable properties, easy to construct, economical, demountable, recyclable and reusable. Component materials of HCFPS include a central Polyurethane (PU) core, outer layers of Glass-fiber Reinforced Cement (GRC) and steel laminates at tensile regions. This research work explored the structural adequacy and performance characteristics of hybridised GRC, PU and steel laminate for the development of HCFPS. Performance characteristics of HCFPS were investigated using Finite Element (FE) method simulations supported by experimental testing. Parametric studies were conducted to develop the HCFPS to satisfy static performance using sectional configurations, spans, loading and material properties as the parameters. Dynamic response of HCFPS floors was investigated by conducting parametric studies using material properties, walking frequency and damping as the parameters. Research findings show that HCFPS can be used in office and residential buildings to provide acceptable static and dynamic performance. Design guidelines were developed for this new floor system. HCFPS is easy to construct and economical compared to conventional floor systems as it is lightweight and prefabricatable floor system. This floor system can also be demounted and reused or recycled at the cessation of use due to its component materials.
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Every day we are confronted with social interactions with other people. Our social life is characterised by norms that manifest as attitudinal and behavioural uniformities among people. With greater awareness about our social context, we can interact more efficiently. Any theory or model of human interaction that fails to include social concepts could be suggested to lack a critical element. This paper identifies the construct of social concepts that need to be supported by future context-aw are systems from an interdisciplinary perspective. It discusses the limitations of existing context-aware systems to support social psychology theories related to the identification and membership of social groups. We argue that social norms are among the core modelling concepts that future context-aware systems need to capture with the view to support and enhance social interactions. A detailed summary of social psychology theory relevant to social computing is given, followed by a formal definition of the process with each such norm advertised and acquired. The social concepts identified in this paper could be used to simulate agent interactions imbued with social norms or use ICT to facilitate, assist, enhance or understand social interactions. They also could be used in virtual communities modelling where the social awareness of a community as well as the process of joining and exiting a community are important.
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LiFePO4 is a commercially available battery material with good theoretical discharge capacity, excellent cycle life and increased safety compared with competing Li-ion chemistries. It has been the focus of considerable experimental and theoretical scrutiny in the past decade, resulting in LiFePO4 cathodes that perform well at high discharge rates. This scrutiny has raised several questions about the behaviour of LiFePO4 material during charge and discharge. In contrast to many other battery chemistries that intercalate homogeneously, LiFePO4 can phase-separate into highly and lowly lithiated phases, with intercalation proceeding by advancing an interface between these two phases. The main objective of this thesis is to construct mathematical models of LiFePO4 cathodes that can be validated against experimental discharge curves. This is in an attempt to understand some of the multi-scale dynamics of LiFePO4 cathodes that can be difficult to determine experimentally. The first section of this thesis constructs a three-scale mathematical model of LiFePO4 cathodes that uses a simple Stefan problem (which has been used previously in the literature) to describe the assumed phase-change. LiFePO4 crystals have been observed agglomerating in cathodes to form a porous collection of crystals and this morphology motivates the use of three size-scales in the model. The multi-scale model developed validates well against experimental data and this validated model is then used to examine the role of manufacturing parameters (including the agglomerate radius) on battery performance. The remainder of the thesis is concerned with investigating phase-field models as a replacement for the aforementioned Stefan problem. Phase-field models have recently been used in LiFePO4 and are a far more accurate representation of experimentally observed crystal-scale behaviour. They are based around the Cahn-Hilliard-reaction (CHR) IBVP, a fourth-order PDE with electrochemical (flux) boundary conditions that is very stiff and possesses multiple time and space scales. Numerical solutions to the CHR IBVP can be difficult to compute and hence a least-squares based Finite Volume Method (FVM) is developed for discretising both the full CHR IBVP and the more traditional Cahn-Hilliard IBVP. Phase-field models are subject to two main physicality constraints and the numerical scheme presented performs well under these constraints. This least-squares based FVM is then used to simulate the discharge of individual crystals of LiFePO4 in two dimensions. This discharge is subject to isotropic Li+ diffusion, based on experimental evidence that suggests the normally orthotropic transport of Li+ in LiFePO4 may become more isotropic in the presence of lattice defects. Numerical investigation shows that two-dimensional Li+ transport results in crystals that phase-separate, even at very high discharge rates. This is very different from results shown in the literature, where phase-separation in LiFePO4 crystals is suppressed during discharge with orthotropic Li+ transport. Finally, the three-scale cathodic model used at the beginning of the thesis is modified to simulate modern, high-rate LiFePO4 cathodes. High-rate cathodes typically do not contain (large) agglomerates and therefore a two-scale model is developed. The Stefan problem used previously is also replaced with the phase-field models examined in earlier chapters. The results from this model are then compared with experimental data and fit poorly, though a significant parameter regime could not be investigated numerically. Many-particle effects however, are evident in the simulated discharges, which match the conclusions of recent literature. These effects result in crystals that are subject to local currents very different from the discharge rate applied to the cathode, which impacts the phase-separating behaviour of the crystals and raises questions about the validity of using cathodic-scale experimental measurements in order to determine crystal-scale behaviour.
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Introduction. Endoscopic anterior scoliosis correction has been employed recently as a less invasive and level-sparing approach compared with open surgical techniques. We have previously demonstrated that during the two-year post-operative period, there was a mean loss of rib hump correction by 1.4 degrees. The purpose of this study was to determine whether intra- or inter-vertebral rotational deformity during the post-operative period could account for the loss of rib hump correction. Materials and Methods. Ten consecutive patients diagnosed with adolescent idiopathic scoliosis were treated with an endoscopic anterior scoliosis correction. Low-dose computed tomography scans of the instrumented segment were obtained post-operatively at 6 and 24 months following institutional ethical approval and patient consent. Three-dimensional multi-planar reconstruction software (Osirix Imaging Software, Pixmeo, Switzerland) was used to create axial slices of each vertebral level, corrected in both coronal and sagittal planes. Vertebral rotation was measured using Ho’s method for every available superior and inferior endplate at 6 and 24 months. Positive changes in rotation indicate a reduction and improvement in vertebral rotation. Intra-observer variability analysis was performed on a subgroup of images. Results. Mean change in rotation for vertebral endplates between 6 and 24 months post-operatively was -0.26˚ (range -3.5 to 4.9˚) within the fused segment and +1.26˚ (range -7.2 to 15.1˚) for the un-instrumented vertebrae above and below the fusion. Mean change in clinically measured rib hump for the 10 patients was -1.6˚ (range -3 to 0˚). The small change in rotation within the fused segment accounts for only 16.5% of the change in rib hump measured clinically whereas the change in rotation between the un-instrumented vertebrae above and below the construct accounts for 78.8%. There was no clear association between rib hump recurrence and intra- or inter-vertebral rotation in individual patients. Intra-rater variability was ± 3˚. Conclusions. Intra- and inter-vertebral rotation continues post-operatively both within the instrumented and un-instrumented segments of the immature spine. Rotation between the un-instrumented vertebrae above and below the fusion was +1.26˚, suggesting that the un-instrumented vertebrae improved and de-rotated slightly after surgery. This may play a role in rib hump recurrence, however this remains clinically insignificant.
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Authenticated Encryption (AE) is the cryptographic process of providing simultaneous confidentiality and integrity protection to messages. This approach is more efficient than applying a two-step process of providing confidentiality for a message by encrypting the message, and in a separate pass providing integrity protection by generating a Message Authentication Code (MAC). AE using symmetric ciphers can be provided by either stream ciphers with built in authentication mechanisms or block ciphers using appropriate modes of operation. However, stream ciphers have the potential for higher performance and smaller footprint in hardware and/or software than block ciphers. This property makes stream ciphers suitable for resource constrained environments, where storage and computational power are limited. There have been several recent stream cipher proposals that claim to provide AE. These ciphers can be analysed using existing techniques that consider confidentiality or integrity separately; however currently there is no existing framework for the analysis of AE stream ciphers that analyses these two properties simultaneously. This thesis introduces a novel framework for the analysis of AE using stream cipher algorithms. This thesis analyzes the mechanisms for providing confidentiality and for providing integrity in AE algorithms using stream ciphers. There is a greater emphasis on the analysis of the integrity mechanisms, as there is little in the public literature on this, in the context of authenticated encryption. The thesis has four main contributions as follows. The first contribution is the design of a framework that can be used to classify AE stream ciphers based on three characteristics. The first classification applies Bellare and Namprempre's work on the the order in which encryption and authentication processes take place. The second classification is based on the method used for accumulating the input message (either directly or indirectly) into the into the internal states of the cipher to generate a MAC. The third classification is based on whether the sequence that is used to provide encryption and authentication is generated using a single key and initial vector, or two keys and two initial vectors. The second contribution is the application of an existing algebraic method to analyse the confidentiality algorithms of two AE stream ciphers; namely SSS and ZUC. The algebraic method is based on considering the nonlinear filter (NLF) of these ciphers as a combiner with memory. This method enables us to construct equations for the NLF that relate the (inputs, outputs and memory of the combiner) to the output keystream. We show that both of these ciphers are secure from this type of algebraic attack. We conclude that using a keydependent SBox in the NLF twice, and using two different SBoxes in the NLF of ZUC, prevents this type of algebraic attack. The third contribution is a new general matrix based model for MAC generation where the input message is injected directly into the internal state. This model describes the accumulation process when the input message is injected directly into the internal state of a nonlinear filter generator. We show that three recently proposed AE stream ciphers can be considered as instances of this model; namely SSS, NLSv2 and SOBER-128. Our model is more general than a previous investigations into direct injection. Possible forgery attacks against this model are investigated. It is shown that using a nonlinear filter in the accumulation process of the input message when either the input message or the initial states of the register is unknown prevents forgery attacks based on collisions. The last contribution is a new general matrix based model for MAC generation where the input message is injected indirectly into the internal state. This model uses the input message as a controller to accumulate a keystream sequence into an accumulation register. We show that three current AE stream ciphers can be considered as instances of this model; namely ZUC, Grain-128a and Sfinks. We establish the conditions under which the model is susceptible to forgery and side-channel attacks.
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Recent advances in the area of ‘Transformational Government’ position the citizen at the centre of focus. This paradigm shift from a department-centric to a citizen-centric focus requires governments to re-think their approach to service delivery, thereby decreasing costs and increasing citizen satisfaction. The introduction of franchises as a virtual business layer between the departments and their citizens is intended to provide a solution. Franchises are structured to address the needs of citizens independent of internal departmental structures. For delivering services online, governments pursue the development of a One-Stop Portal, which structures information and services through those franchises. Thus, each franchise can be mapped to a specific service bundle, which groups together services that are deemed to be of relevance to a specific citizen need. This study focuses on the development and evaluation of these service bundles. In particular, two research questions guide the line of investigation of this study: Research Question 1): What methods can be used by governments to identify service bundles as part of governmental One-Stop Portals? Research Question 2): How can the quality of service bundles in governmental One-Stop Portals be evaluated? The first research question asks about the identification of suitable service bundle identification methods. A literature review was conducted, to, initially, conceptualise the service bundling task, in general. As a consequence, a 4-layer model of service bundling and a morphological box were created, detailing characteristics that are of relevance when identifying service bundles. Furthermore, a literature review of Decision-Support Systems was conducted to identify approaches of relevance in different bundling scenarios. These initial findings were complemented by targeted studies of multiple leading governments in the e-government domain, as well as with a local expert in the field. Here, the aim was to identify the current status of online service delivery and service bundling in practice. These findings led to the conceptualising of two service bundle identification methods, applicable in the context of Queensland Government: On the one hand, a provider-driven approach, based on service description languages, attributes, and relationships between services was conceptualised. As well, a citizen-driven approach, based on analysing the outcomes from content identification and grouping workshops with citizens, was also conceptualised. Both methods were then applied and evaluated in practice. The conceptualisation of the provider-driven method for service bundling required the initial specification of relevant attributes that could be used to identify similarities between services called relationships; these relationships then formed the basis for the identification of service bundles. This study conceptualised and defined seven relationships, namely ‘Co-location’, ‘Resource’, ‘Co-occurrence’, ‘Event’, ‘Consumer’, ‘Provider’, and ‘Type’. The relationships, and the bundling method itself, were applied and refined as part of six Action Research cycles in collaboration with the Queensland Government. The findings show that attributes and relationships can be used effectively as a means for bundle identification, if distinct decision rules are in place to prescribe how services are to be identified. For the conceptualisation of the citizen-driven method, insights from the case studies led to the decision to involve citizens, through card sorting activities. Based on an initial list of services, relevant for a certain franchise, participating citizens grouped services according to their liking. The card sorting activity, as well as the required analysis and aggregation of the individual card sorting results, was analysed in depth as part of this study. A framework was developed that can be used as a decision-support tool to assist with the decision of what card sorting analysis method should be utilised in a given scenario. The characteristic features associated with card sorting in a government context led to the decision to utilise statistical analysis approaches, such as cluster analysis and factor analysis, to aggregate card sorting results. The second research question asks how the quality of service bundles can be assessed. An extensive literature review was conducted focussing on bundle, portal, and e-service quality. It was found that different studies use different constructs, terminology, and units of analysis, which makes comparing these models a difficult task. As a direct result, a framework was conceptualised, that can be used to position past and future studies in this research domain. Complementing the literature review, interviews conducted as part of the case studies with leaders in e-government, indicated that, typically, satisfaction is evaluated for the overall portal once the portal is online, but quality tests are not conducted during the development phase. Consequently, a research model which appropriately defines perceived service bundle quality would need to be developed from scratch. Based on existing theory, such as Theory of Reasoned Action, Expectation Confirmation Theory, and Theory of Affordances, perceived service bundle quality was defined as an inferential belief. Perceived service bundle quality was positioned within the nomological net of services. Based on the literature analysis on quality, and on the subsequent work of a focus group, the hypothesised antecedents (descriptive beliefs) of the construct and the associated question items were defined and the research model conceptualised. The model was then tested, refined, and finally validated during six Action Research cycles. Results show no significant difference in higher quality or higher satisfaction among users for either the provider-driven method or for the citizen-driven method. The decision on which method to choose, it was found, should be based on contextual factors, such as objectives, resources, and the need for visibility. The constructs of the bundle quality model were examined. While the quality of bundles identified through the citizen-centric approach could be explained through the constructs ‘Navigation’, ‘Ease of Understanding’, and ‘Organisation’, bundles identified through the provider-driven approach could be explained solely through the constructs ‘Navigation’ and ‘Ease of Understanding’. An active labelling style for bundles, as part of the provider-driven Information Architecture, had a larger impact on ‘Quality’ than the topical labelling style used in the citizen-centric Information Architecture. However, ‘Organisation’, reflecting the internal, logical structure of the Information Architecture, was a significant factor impacting on ‘Quality’ only in the citizen-driven Information Architecture. Hence, it was concluded that active labelling can compensate for a lack of logical structure. Further studies are needed to further test this conjecture. Such studies may involve building alternative models and conducting additional empirical research (e.g. use of an active labelling style for the citizen-driven Information Architecture). This thesis contributes to the body of knowledge in several ways. Firstly, it presents an empirically validated model of the factors explaining and predicting a citizen’s perception of service bundle quality. Secondly, it provides two alternative methods that can be used by governments to identify service bundles in structuring the content of a One-Stop Portal. Thirdly, this thesis provides a detailed narrative to suggest how the recent paradigm shift in the public domain, towards a citizen-centric focus, can be pursued by governments; the research methodology followed by this study can serve as an exemplar for governments seeking to achieve a citizen-centric approach to service delivery.
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Learning can allow individuals to increase their fitness in particular environments. The advantage to learning depends on the predictability of the environment and the extent to which animals can adjust their behaviour. Earlier general models have investigated when environmental predictability might favour the evolution of learning in foraging animals. Here, we construct a theoretical model that predicts the advantages to learning using a specific biological example: oviposition in the Lepidoptera. Our model includes environmental and behavioural complexities relevant to host selection in these insects and tests whether the predictions of the general models still hold. Our results demonstrate how the advantage of learning is maximised when within-generation variability is minimised (the local environment consists mainly of a single host plant species) and between-generation variability is maximised (different host plant species are the most common in different generations). We discuss how our results: (a) can be applied to recent empirical work in different lepidopteran species and (b) predict an important role of learning in lepidopteran agricultural pests.
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This research is an autoethnographic investigation of consumption experiences, public and quasi-public spaces, and their relationship to community within an inner city neighbourhood. The research specifically focuses on the gentrifying inner city, where class-based processes of change can have implications for people’s abilities to remain within, or feel connected to place. However, the thesis draws on broader theories of the throwntogetherness of the contemporary city (e.g., Amin and Thrift, 2002; Massey 2005) to argue that the city is a space where place-based meanings cannot be seen to be fixed, and are instead better understood as events of place – based on ever shifting interrelations between the trajectories of people and things. This perspective argues the experience of belonging to community is not just born of a social encounter, but also draws on the physical and symbolic elements of the context in which it is situated. The thesis particularly explores the ways people construct identifications within this shifting urban environment. As such, consumption practices and spaces offer one important lens through which to explore the interplay of the physical, social and symbolic. Consumer research tells us that consumption practices can facilitate experiences in which identity-defining meaning can be generated and shared. Consumption spaces can also support different kinds of collective identification – as anchoring realms for specific cultural groups or exposure realms that enable individuals to share in the identification practices of others with limited risk (Aubert-Gamet & Cova, 1999). Furthermore, the consumption-based lifestyles that gentrifying inner city neighbourhoods both support and encourage can also mean that consumption practices may be a key reason that people are moving through public space. That is, consumption practices and spaces may provide a purpose for which – and spatial frame against which – our everyday interactions and connections with people and objects are undertaken within such neighbourhoods. The purpose of this investigation then was to delve into the subjectivities at the heart of identifying with places, using the lens of our consumption-based experiences within them. The enquiry describes individual and collective identifications and emotional connections, and explores how these arise within and through our experiences within public and quasi-public spaces. It then theorises these ‘imaginings’ as representative of an experience of community. To do so, it draws on theories of imagination and its relation to community. Theories of imagined community remind us that both the values and identities of community are held together by projections that create relational links out of objects and shared practices (e.g., Benedict Anderson, 2006; Urry, 2000). Drawing on broader theories of the processes of the imagination, this thesis suggests that an interplay between reflexivity and fantasy – which are products of the critical and the fascinated consciousness – plays a role in this imagining of community (e.g., Brann, 1991; Ricoeur, 1994). This thesis therefore seeks to explore how these processes of imagining are implicated within the construction of an experience of belonging to neighbourhood-based community through consumption practices and the public and quasi-public spaces that frame them. The key question of this thesis is how do an individual’s consumption practices work to construct an imagined presence of neighbourhood-based community? Given the focus on public and quasi-public spaces and our experiences within them, the research also asked how do experiences in the public and quasi-public spaces that frame these practices contribute to the construction of this imagined presence? This investigation of imagining community through consumption practices is based on my own experiences of moving to, and attempting to construct community connections within, an inner city neighbourhood in Melbourne, Australia. To do so, I adopted autoethnographic methodology. This is because autoethnography provides the methodological tools through which one can explore and make visible the subjectivities inherent within the lived experiences of interest to the thesis (Ellis, 2004). I describe imagining community through consumption as an extension of a placebased self. This self is manifest through personal identification in consumption spaces that operate as anchoring realms for specific cultural groups, as well as through a broader imagining of spaces, people, and practices as connected through experiences within realms of exposure. However, this is a process that oscillates through cycles of identification; these anchor one within place personally, but also disrupt those attachments. This instability can force one to question the orientation and motives of these imaginings, and reframe them according to different spaces and reference groups in ways that can also work to construct a more anonymous and, conversely, more achievable collective identification. All the while, the ‘I’ at the heart of this identification is in an ongoing process of negotiation, and similarly, the imagined community is never complete. That is, imagining community is a negotiation, with people and spaces – but mostly with the different identifications of the self. This thesis has been undertaken by publication, and thus the process of imagining community is explored and described through four papers. Of these, the first two focus on specific types of consumption spaces – a bar and a shopping centre – and consider the ways that anchoring and exposure within these spaces support the process of imagining community. The third paper examines the ways that the public and quasi-public spaces that make up the broader neighbourhood context are themselves throwntogether as a realm of exposure, and considers the ways this shapes my imaginings of this neighbourhood as community. The final paper develops a theory of imagined community, as a process of comparison and contrast with imagined others, to provide a summative conceptualisation of the first three papers. The first paper, chapter five, explores this process of comparison and contrast in relation to authenticity, which in itself is a subjective assessment of identity. This chapter was written as a direct response to the recent work of Zukin (2010), and draws on theories of authenticity as applied to personal and collective identification practices by consumer researchers Arnould and Price (2000). In this chapter, I describe how my assessments of the authenticity of my anchoring experiences within one specific consumption space, a neighbourhood bar, are evaluated in comparison to my observations of and affective reactions to the social practices of another group of residents in a different consumption space, the local shopping centre. Chapter five also provides an overview of the key sites and experiences that are considered in more detail in the following two chapters. In chapter six, I again draw on my experiences within the bar introduced in chapter five, this time to explore the process of developing a regular identity within a specific consumption space. Addressing the popular theory of the cafe or bar as third place (Oldenburg, 1999), this paper considers the purpose of developing anchored relationships with people within specific consumption spaces, and explores the different ways this may be achieved in an urban context where the mobilities and lifestyle practices of residents complicate the idea of a consumption space as an anchoring or third place. In doing so, this chapter also considers the manner in which this type of regular identification may be seen to be the beginning of the process of imagining community. In chapter seven, I consider the ways the broader public spaces of the neighbourhood work cumulatively to expose different aspects of its identity by following my everyday movements through the neighbourhood’s shopping centre and main street. Drawing on the theories of Urry (2000), Massey (2005), and Amin (2007, 2008), this chapter describes how these spaces operate as exposure realms, enabling the expression of different senses of the neighbourhood’s spaces, times, cultures, and identities through their physical, social, and symbolic elements. Yet they also enable them to be united: through habitual pathways, group practices of appropriation of space, and memory traces that construct connections between objects and experiences. This chapter describes this as a process of exposure to these different elements. Our imagination begins to expand the scope of the frames onto which it projects an imagined presence; it searches for patterns within the physical, social, and symbolic environment and draws connections between people and practices across spaces. As the final paper, chapter eight, deduces, it is in making these connections that one constructs the objects and shared practices of imagined community. This chapter describes this as an imagining of neighbourhood as a place-based extension of the self, and then explores the ways in which I drew on physical, social, and symbolic elements in an attempt to construct a fit between the neighbourhood’s offerings and my desires for place-based identity definition. This was as a cumulative but fragmented process, in which positive and negative experiences of interaction and identification with people and things were searched for their potential to operate as the objects and shared practices of imagined community. This chapter describes these connections as constructed through interplay between reflexivity and fantasy, as the imagination seeks balance between desires for experiences of belonging, and the complexities of constructing them within the throwntogether context of the contemporary city. The conclusion of the thesis describes the process of imagining community as a reflexive fantasy, that is, as a product of both the critical and fascinated consciousness (Ricoeur, 1994). It suggests that the fascinated consciousness imbues experiences with hope and desire, which the reflexive imagining can turn to disappointment and shame as it critically reflects on the reality of those fascinated projections. At the same time, the reflexive imagination also searches the practices of others for affirmation of those projections, effectively seeking to prove the reality of the fantasy of the imagined community.
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Introduction: Recent advances in the planning and delivery of radiotherapy treatments have resulted in improvements in the accuracy and precision with which therapeutic radiation can be administered. As the complexity of the treatments increases it becomes more difficult to predict the dose distribution in the patient accurately. Monte Carlo (MC) methods have the potential to improve the accuracy of the dose calculations and are increasingly being recognised as the ‘gold standard’ for predicting dose deposition in the patient [1]. This project has three main aims: 1. To develop tools that enable the transfer of treatment plan information from the treatment planning system (TPS) to a MC dose calculation engine. 2. To develop tools for comparing the 3D dose distributions calculated by the TPS and the MC dose engine. 3. To investigate the radiobiological significance of any errors between the TPS patient dose distribution and the MC dose distribution in terms of Tumour Control Probability (TCP) and Normal Tissue Complication Probabilities (NTCP). The work presented here addresses the first two aims. Methods: (1a) Plan Importing: A database of commissioned accelerator models (Elekta Precise and Varian 2100CD) has been developed for treatment simulations in the MC system (EGSnrc/BEAMnrc). Beam descriptions can be exported from the TPS using the widespread DICOM framework, and the resultant files are parsed with the assistance of a software library (PixelMed Java DICOM Toolkit). The information in these files (such as the monitor units, the jaw positions and gantry orientation) is used to construct a plan-specific accelerator model which allows an accurate simulation of the patient treatment field. (1b) Dose Simulation: The calculation of a dose distribution requires patient CT images which are prepared for the MC simulation using a tool (CTCREATE) packaged with the system. Beam simulation results are converted to absolute dose per- MU using calibration factors recorded during the commissioning process and treatment simulation. These distributions are combined according to the MU meter settings stored in the exported plan to produce an accurate description of the prescribed dose to the patient. (2) Dose Comparison: TPS dose calculations can be obtained using either a DICOM export or by direct retrieval of binary dose files from the file system. Dose difference, gamma evaluation and normalised dose difference algorithms [2] were employed for the comparison of the TPS dose distribution and the MC dose distribution. These implementations are spatial resolution independent and able to interpolate for comparisons. Results and Discussion: The tools successfully produced Monte Carlo input files for a variety of plans exported from the Eclipse (Varian Medical Systems) and Pinnacle (Philips Medical Systems) planning systems: ranging in complexity from a single uniform square field to a five-field step and shoot IMRT treatment. The simulation of collimated beams has been verified geometrically, and validation of dose distributions in a simple body phantom (QUASAR) will follow. The developed dose comparison algorithms have also been tested with controlled dose distribution changes. Conclusion: The capability of the developed code to independently process treatment plans has been demonstrated. A number of limitations exist: only static fields are currently supported (dynamic wedges and dynamic IMRT will require further development), and the process has not been tested for planning systems other than Eclipse and Pinnacle. The tools will be used to independently assess the accuracy of the current treatment planning system dose calculation algorithms for complex treatment deliveries such as IMRT in treatment sites where patient inhomogeneities are expected to be significant. Acknowledgements: Computational resources and services used in this work were provided by the HPC and Research Support Group, Queensland University of Technology, Brisbane, Australia. Pinnacle dose parsing made possible with the help of Paul Reich, North Coast Cancer Institute, North Coast, New South Wales.