985 resultados para Many-valued logic


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Riparian zones are a characteristic component of many landscapes throughout the world and increasingly are valued as key areas for biodiversity conservation. Their importance for bird communities has been well recognised in semi-arid environments and in modified landscapes where there is a marked contrast between riparian and adjacent non-riparian vegetation. The value of riparian zones in largely intact landscapes with continuous vegetation cover is less well understood. This research examined the importance of riparian habitats for avifauna conservation by investigating the ecological interactions contributing to the pattern of bird assemblages in riparian and adjacent non-riparian habitats. Specifically, the focus is on the bird assemblages of riparian zones and those of adjacent non-riparian vegetation types and the influence that associated differences in resource availabilities, habitat structure and conditions have on observed patterns. This study was conducted in the foothill forests of the Victorian Highlands, south-east Australia. Mixed-species eucalypt (genus Eucalyptus) forests dominate the vegetation of this region. Site selection was based on the occurrence of suitable riparian habitat interspersed within extensive, relatively undisturbed (i.e. no recent timber harvesting or fire events) forest mosaics. A series of 30 paired riparian and non-riparian sites were established among six stream systems in three forest areas (Bunyip State Park, Kinglake National Park and Marysville State Forest). Riparian sites were positioned alongside the stream and the non-riparian partner site was positioned on a facing slope at a distance of approximately 750 m. Bird surveys were carried out during 29 visits to each site between July 2001 and December 2002. Riparian sites were floristically distinct from non-riparian sites and had a more complex vegetation structure, including a mid-storey tree layer mostly absent from non-riparian sites, extensive fine litter and coarse woody debris, and dense ground-layer vegetation (e.g. sedges and ground ferns). The characteristic features of non-riparian habitats included a relatively dense canopy cover, a ground layer dominated by grasses and fine litter, and a high density of canopy-forming trees in the smaller size-classes. Riparian zones supported a significantly greater species richness, abundance and diversity of birds when compared to non-riparian habitats. The composition of bird assemblages differed significantly between riparian and non-riparian habitats, with riparian assemblages displaying a higher level of similarity among sites. The strongest contributors to observed dissimilarities between habitat types included species that occurred exclusively in either habitat type or species with large contrasts in abundance between habitat types. Much of the avifauna (36%) of the study area is composed of species that are common and widespread in south-east Australia (i.e. forest generalists). Riparian habitats were characterised by a suite of species more typical of wetter forest types in south-east Australia and many of these species had a restricted distribution in the forest mosaic. Some species (7%) occurred exclusively in riparian habitats (i.e. riparian selective species) while others (43%) were strongly linked to these habitats (i.e. riparian associated species). A smaller proportion of species occurred exclusively (2%) in non-riparian habitats (i.e. non-riparian selective species) or were strongly linked to these habitats (10%; i.e. non-riparian associated species). To examine the seasonal dynamics of assemblages, the variation through time in species richness, abundance and composition was compared between riparian and non-riparian sites. Riparian assemblages supported greater richness and abundance, and displayed less variation in these parameters, than non-riparian assemblages at all times. The species composition of riparian assemblages was distinct from non-riparian assemblages throughout the annual cycle. An influx of seasonal migrants elevated species richness and abundance in the forest landscape during spring and summer. The large-scale movement pattern (e.g. coastal migrant, inland migrant) adopted by migrating species was associated with their preference for riparian or non-riparian habitats in the landscape. Species which migrate north-south along the east coast of mainland Australia (i.e. coastal migrants) used riparian zones disproportionately; eight of eleven species were riparian associated species. Species which migrate north-south through inland Australia (i.e. inland migrants) were mostly associated with non-riparian habitats. The significant differences in the dynamics of community structure between riparian and non-riparian assemblages shows that there is a disproportionate use of riparian zones across the landscape and that they provide higher quality habitat for birds throughout the annual cycle. To examine the ecological mechanisms by which riparian assemblages are richer and support more individual birds, the number of ecological groups (foraging, nest-type and body mass groups) represented, and the species richness of these groups, was compared between riparian and non-riparian assemblages. The structurally complex vegetation and distinctive habitat features (e.g. aquatic environments, damp sheltered litter) provided in the riparian zone, resulted in the consistent addition of ecological groups to riparian assemblages (e.g. sheltered ground – invertebrates foraging group) compared with non-riparian assemblages. Greater species richness was accommodated in most foraging, nest-type and body mass groups in riparian than non-riparian assemblages. Riparian zones facilitated greater richness within ecological groups by providing conditions (i.e. more types of resources and greater abundance of resources) that promoted ecological segregation between ecologically similar species. For a set of commonly observed species, significant differences in their use of structural features, substrates and heights were registered between riparian and non-riparian habitats. The availability and dynamics of resources in riparian and non-riparian habitats were examined to determine if there is differential availability of particular resources, or in their temporal availability, throughout the annual cycle. Riparian zones supported more abundant and temporally reliable eucalypt flowering (i.e. nectar) than non-riparian habitats throughout the annual cycle. Riparian zones also supported an extensive loose bark resource (an important microhabitat for invertebrates) including more peeling bark and hanging bark throughout the year than at non-riparian sites. The productivity of eucalypts differed between habitat types, being higher in riparian zones at most times for all eucalypts combined, and for some species (e.g. Narrow-leaved Peppermint Eucalyptus radiata). Non-riparian habitats provided an abundant nectar resource (i.e. shrub flowering) at particular periods in the annual cycle. Birds showed clear relationships with the availability of specific food (i.e. nectar) and foraging resources (i.e. loose bark). The demonstration of a greater abundance of resources and higher primary productivity in riparian zones is consistent with the hypothesis that these linear strips that occupy only a small proportion of the landscape have a disproportionately high value for birds. Riparian zones in continuous eucalypt forest provide high quality habitats that contribute to the diversity of habitats and resources available to birds in the forest mosaic, with positive benefits for the landscape-level species pool. Despite riparian and non-riparian habitat supporting distinct assemblages of birds, strong linkages are maintained along the riparian-upslope gradient. Clearly, the maintenance of diverse and sustainable assemblages of birds in forest landscapes depends on complementary management of both riparian and non-riparian vegetation.

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The focus of this doctoral research study is making the most what a person knows and can do, as an outcome from their lifelong learning, so as to better contribute to organisational achievement. This has been motivated by a perceived gap in the extensive literature linking knowledge with organisational achievement. Whereas there is a rich body of literature addressing the meta-philosophies giving rise to the emergence of learning organisations there is, as yet, scant attention paid to the detail of planning and implementing action which would reveal individual/organisational opportunities of mutual advantage and motivate, and sustain, participation at the day-to-day level of the individual. It is in this space that this dissertation seeks to contribute by offering a mechanism for bringing the, hindsight informed, response “but that’s obvious” into the abiding explicit realm at the level of the individual. In moving beyond the obvious which is prone to be overlooked, the emphasis on “better” in the introductory sentence, is very deliberately made and has a link to awakening latent individual, and hence organisational, capabilities that would otherwise languish. The evolved LCM Model – a purposeful integration valuing the outcomes from lifelong learning (the L) with nurturing a culture supporting this outcome (the C) and with responsiveness to potentially diverse motivations (the M) – is a reflective device for bringing otherwise tacit, and latent, logic into the explicit realm of action. In the course of the development of the model, a number of supplementary models included in this dissertation have evolved from the research. They form a suite of devices which inform action and lead to making the most of what an individual knows and can do within the formal requirements of a job and within the informal influences of a frequently invisible community of practice. The initial inquiry drew upon the views and experiences of water industry engineering personnel and training facilitators associated with the contract cleaning and waste management industries. However, the major research occurred as an Emergency Management Australia (EMA) project with the Country Fire Authority (CFA) as the host organisation. This EMA/CFA research project explored the influence of making the most of what a CFA volunteer knows and can do upon retention of that volunteer. In its aggregate, across the CFA volunteer body, retention is a critical community safety objective. A qualitative research, ethnographic in character, approach was adopted. Data was collected through interviews, workshops and outcomes from attempts at action research projects. Following an initial thirteen month scoping study including respondents other than from the CFA, the research study moved into an exploration of the efficacy of an indicative model with four contextual foci – i.e. the manner of welcoming new members to the CFA, embracing training, strengthening brigade sustainability and leadership. Interestingly, the research environment which forced a truncated implementation of action research projects was, in itself, an informing experience indicative of inhibitors to making the most of what people know and can do. Competition for interest, time and commitment were factors governing the manner in which CFA respondents could be called upon to explore the efficacy of the model, and were a harbinger of the influences shaping the more general environment of drawing upon what CFA volunteers know and can do. Subsequent to the development of the indicative model, a further 16 month period was utilised in the ethnographic exploration of the relevance of the model within the CFA as the host organisation. As a consequence, the model is a more fully developed tool (framework) to aid reflection, planning and action. Importantly, the later phase of the research study has, through application of the model to specific goals within the CFA, yielded operational insight into its effective use, and in which activity systems have an important place. The model – now confidently styled as the LCM Model – has three elements that when enmeshed strengthen the likelihood of organisational achievement ; and the degree of this meshing, as relevant to the target outcome, determines the strength of outcome. i.e. - • Valuing outcomes from learning: When a person recognises and values (appropriately to achievement by the organisation) what they know and can do, and associated others recognise and value what this person knows and can do, then there is increased likelihood of these outcomes from learning being applied to organisational achievement. • Valuing a culture that is conducive to learning: When a person, and associated others, are further developing and drawing upon what they know and can do within the context of a culture that is conducive to learning, then there is increased likelihood that outcomes from learning will be applied to organisational achievement. • Valuing motivation of the individual: When a person’s motivation to apply what they know and can do is valued by them, and associated others, as appropriate to organisational achievement then there is increased likelihood that appropriately drawing upon outcomes from learning will occur. Activity theory was employed as a device to scope and explore understanding of the issues as they emerged in the course of the research study. Viewing the data through the prism of activity theory led not only to the development of the LCM Model but also to an enhanced understanding of the role of leadership as a foundation for acting upon the model. Both formal and informal leadership were found to be germane in asserting influence on empowering engagement with learning and drawing upon its outcomes. It is apparent that a “leaderful organisation”, as postulated by Raelin (2003), is an environment which supports drawing upon the LCM model; and it may be the case that the act of drawing upon the model will move a narrowly leadership focused organisation toward leaderful attributes. As foreshadowed at the beginning of this synopsis, nurturing individual and organisational capability is the guiding mantra for this dissertation - “Capability embraces competence but is also forward-looking, concerned with the realisation of potential” (Stephenson 1998, p. 3). Although the inquiry focussed upon a need for CFA volunteer retention, it began with a broader investigation as part of the scoping foundation and the expanded usefulness of the LCM Model invites further investigation. The dissertation concludes with the encapsulating sentiment that “You have really got to want to”. With this predisposition in mind, this dissertation contributes to knowledge through the development and discussion of the LCM model as a reflective device informing transformative learning (Mezirow and Associates 1990). A leaderful environment (Raelin 2003) aids transformative learning – accruing to the individual and the organisation - through engendering and maintaining making the most of knowledge and skill – motivating and sustaining “the will”. The outcomes from this research study are a strong assertion that wanting to make the most of what is known and can be done is a hallmark of capability. Accordingly, this dissertation is a contribution to the “how” of strengthening the capability, and the commitment to applying that capability, of an individual and an organisation.

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This thesis explores the construction of technological expertise amongst a heterogenous group of New Zealand teenagers, specifically in regard to their home computer use, which for many of them is their primary site of leisure. This thesis explores the field in which these teenagers are positioned, and explains the practice constituting that field. In this field, the trajectories towards expertise are explained including the time, experimentation, and pleasure evident in their praxis. The qualitative study involved observations and interviews with eight teenagers aged 13 – 17. Five boys and three girls participated and each attended one of various secondary schools located within a provincial city in New Zealand. All of the participants considered themselves to be technological experts, and their peers and/or their family supported this comprehension. Drawing on Pierre Bourdieu’s socio-cultural theories, the capital (cultural, economic, social) and habitus of the teenagers are described (habitus being what makes them who they are, and continues to define who they are in the future). Chapter five centres on explaining the field the teenagers have positioned themselves in, namely the field of out-of-school leisure and home computer use. It also explores the construction and performance of technological expertise within the field. Chapter six examines traditional views of schooling and expertise, and contrasts these views with what the teenagers think about their learning and expertise. This gap is specifically explained with regard to differences between the concepts and value of learning, expertise, and technology, and how they are recognised and valued differently between generations. Chapter seven explores the praxis that the participants exhibit, which is arguably misrecognized by those whose interests are in the established order (e.g. institutional, societal structures). The field they are placed in is arguably part of the broader field of education, yet the findings suggest their capital is misrecognized by digital newcomers, and therefore not legitimated. This thesis concludes that the gap between teenager and adult understandings of expertise is exacerbated in the digital world in which the teenagers position themselves. Their schooling is mainly positioned in the print culture of previous generations and consequently, in the lives of these teenagers, schooling has had little influence on the development of their technological expertise. Additionally, gender has had little impact in their development of expertise; therefore stereotypical notions of female underachievement as computer experts are contested.

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Classification learning is dominated by systems which induce large numbers of small axis-orthogonal decision surfaces. This strongly biases such systems towards particular hypothesis types but there is reason believe that many domains have underlying concepts which do not involve axis orthogonal surfaces. Further, the multiplicity of small decision regions mitigates against any holistic appreciation of the theories produced by these systems, notwithstanding the fact that many of the small regions are individually comprehensible. This thesis investigates modeling concepts as large geometric structures in n-dimensional space. Convex hulls are a superset of the set of axis orthogonal hyperrectangles into which axis orthogonal systems partition the instance space. In consequence, there is reason to believe that convex hulls might provide a more flexible and general learning bias than axis orthogonal regions. The formation of convex hulls around a group of points of the same class is shown to be a usable generalisation and is more general than generalisations produced by axis-orthogonal based classifiers, without constructive induction, like decision trees, decision lists and rules. The use of a small number of large hulls as a concept representation is shown to provide classification performance which can be better than that of classifiers which use a large number of small fragmentary regions for each concept. A convex hull based classifier, CH1, has been implemented and tested. CH1 can handle categorical and continuous data. Algorithms for two basic generalisation operations on hulls, inflation and facet deletion, are presented. The two operations are shown to improve the accuracy of the classifier and provide moderate classification accuracy over a representative selection of typical, largely or wholly continuous valued machine learning tasks. The classifier exhibits superior performance to well-known axis-orthogonal-based classifiers when presented with domains where the underlying decision surfaces are not axis parallel. The strengths and weaknesses of the system are identified. One particular advantage is the ability of the system to model domains with approximately the same number of structures as there are underlying concepts. This leads to the possibility of extraction of higher level mathematical descriptions of the induced concepts, using the techniques of computational geometry, which is not possible from a multiplicity of small regions.

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Electronic commerce and the Internet have created demand for automated systems that can make complex decisions utilizing information from multiple sources. Because the information is uncertain, dynamic, distributed, and heterogeneous in nature, these systems require a great diversity of intelligent techniques including expert systems, fuzzy logic, neural networks, and genetic algorithms. However, in complex decision making, many different components or sub-tasks are involved, each of which requires different types of processing. Thus multiple such techniques are required resulting in systems called hybrid intelligent systems. That is, hybrid solutions are crucial for complex problem solving and decision making. There is a growing demand for these systems in many areas including financial investment planning, engineering design, medical diagnosis, and cognitive simulation. However, the design and development of these systems is difficult because they have a large number of parts or components that have many interactions. From a multi-agent perspective, agents in multi-agent systems (MAS) are autonomous and can engage in flexible, high-level interactions. MASs are good at complex, dynamic interactions. Thus a multi-agent perspective is suitable for modeling, design, and construction of hybrid intelligent systems. The aim of this thesis is to develop an agent-based framework for constructing hybrid intelligent systems which are mainly used for complex problem solving and decision making. Existing software development techniques (typically, object-oriented) are inadequate for modeling agent-based hybrid intelligent systems. There is a fundamental mismatch between the concepts used by object-oriented developers and the agent-oriented view. Although there are some agent-oriented methodologies such as the Gaia methodology, there is still no specifically tailored methodology available for analyzing and designing agent-based hybrid intelligent systems. To this end, a methodology is proposed, which is specifically tailored to the analysis and design of agent-based hybrid intelligent systems. The methodology consists of six models - role model, interaction model, agent model, skill model, knowledge model, and organizational model. This methodology differs from other agent-oriented methodologies in its skill and knowledge models. As good decisions and problem solutions are mainly based on adequate information, rich knowledge, and appropriate skills to use knowledge and information, these two models are of paramount importance in modeling complex problem solving and decision making. Follow the methodology, an agent-based framework for hybrid intelligent system construction used in complex problem solving and decision making was developed. The framework has several crucial characteristics that differentiate this research from others. Four important issues relating to the framework are also investigated. These cover the building of an ontology for financial investment, matchmaking in middle agents, reasoning in problem solving and decision making, and decision aggregation in MASs. The thesis demonstrates how to build a domain-specific ontology and how to access it in a MAS by building a financial ontology. It is argued that the practical performance of service provider agents has a significant impact on the matchmaking outcomes of middle agents. It is proposed to consider service provider agents' track records in matchmaking. A way to provide initial values for the track records of service provider agents is also suggested. The concept of ‘reasoning with multimedia information’ is introduced, and reasoning with still image information using symbolic projection theory is proposed. How to choose suitable aggregation operations is demonstrated through financial investment application and three approaches are proposed - the stationary agent approach, the token-passing approach, and the mobile agent approach to implementing decision aggregation in MASs. Based on the framework, a prototype was built and applied to financial investment planning. This prototype consists of one serving agent, one interface agent, one decision aggregation agent, one planning agent, four decision making agents, and five service provider agents. Experiments were conducted on the prototype. The experimental results show the framework is flexible, robust, and fully workable. All agents derived from the methodology exhibit their behaviors correctly as specified.

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Both scholarly literature and popular media often depict predominantly negative and one-dimensional images of boys, especially African-American boys. Predictions of these boys’ anticipated difficulties in school and adulthood are equally prevalent. This paper reports qualitative research that features case studies of nine urban boys of color, aged nine to eleven, who participated in an afterschool program where they learned to create digital multimedia texts. Drawing on an analysis of the children’s patterns of participation, their multimodal products, and their social and intellectual growth over time, the study revealed that these children demonstrated many versions of male selves, and that their digital stories narrated these identities in ways that often challenged hegemonic versions of masculinity. These enactments of identity were made possible by the ways that their afterschool social space structured their activities, as well as by the symbolic means and subject matters privileged in that space, principally digital multimodal narratives and popular culture. At a time when afterschool programs are under pressure to become extensions of the school day, this research argues for recognition of and support for the different functions such programs can serve when structured as alternative spaces for learning and identity formation.

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This thesis, using a computer simulation, studies the effect of the normal distribution assumption on the power of several many-sample location and scale test procedures. It also suggests an almost robust parametric test, namely numerical likelihood ratio test (NLRT) for non-normal situations. The NLRT is found better than all of the tests considered. Some real life data sets were used as examples.