358 resultados para Area-restricted search


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This research has made contributions to the area of spoken term detection (STD), defined as the process of finding all occurrences of a specified search term in a large collection of speech segments. The use of visual information in the form of lip movements of the speaker in addition to audio and the use of topic of the speech segments, and the expected frequency of words in the target speech domain, are proposed. By using these complementary information, improvement in the performance of STD has been achieved which enables efficient search of key words in large collection of multimedia documents.

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This report describes the development and simulation of a variable rate controller for a 6-degree of freedom nonlinear model. The variable rate simulation model represents an off the shelf autopilot. Flight experiment involves risks and can be expensive. Therefore a dynamic model to understand the performance characteristics of the UAS in mission simulation before actual flight test or to obtain parameters needed for the flight is important. The control and guidance is implemented in Simulink. The report tests the use of the model for air search and air sampling path planning. A GUI in which a set of mission scenarios, in which two experts (mission expert, i.e. air sampling or air search and an UAV expert) interact, is presented showing the benefits of the method.

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Species distribution modelling (SDM) typically analyses species’ presence together with some form of absence information. Ideally absences comprise observations or are inferred from comprehensive sampling. When such information is not available, then pseudo-absences are often generated from the background locations within the study region of interest containing the presences, or else absence is implied through the comparison of presences to the whole study region, e.g. as is the case in Maximum Entropy (MaxEnt) or Poisson point process modelling. However, the choice of which absence information to include can be both challenging and highly influential on SDM predictions (e.g. Oksanen and Minchin, 2002). In practice, the use of pseudo- or implied absences often leads to an imbalance where absences far outnumber presences. This leaves analysis highly susceptible to ‘naughty-noughts’: absences that occur beyond the envelope of the species, which can exert strong influence on the model and its predictions (Austin and Meyers, 1996). Also known as ‘excess zeros’, naughty noughts can be estimated via an overall proportion in simple hurdle or mixture models (Martin et al., 2005). However, absences, especially those that occur beyond the species envelope, can often be more diverse than presences. Here we consider an extension to excess zero models. The two-staged approach first exploits the compartmentalisation provided by classification trees (CTs) (as in O’Leary, 2008) to identify multiple sources of naughty noughts and simultaneously delineate several species envelopes. Then SDMs can be fit separately within each envelope, and for this stage, we examine both CTs (as in Falk et al., 2014) and the popular MaxEnt (Elith et al., 2006). We introduce a wider range of model performance measures to improve treatment of naughty noughts in SDM. We retain an overall measure of model performance, the area under the curve (AUC) of the Receiver-Operating Curve (ROC), but focus on its constituent measures of false negative rate (FNR) and false positive rate (FPR), and how these relate to the threshold in the predicted probability of presence that delimits predicted presence from absence. We also propose error rates more relevant to users of predictions: false omission rate (FOR), the chance that a predicted absence corresponds to (and hence wastes) an observed presence, and the false discovery rate (FDR), reflecting those predicted (or potential) presences that correspond to absence. A high FDR may be desirable since it could help target future search efforts, whereas zero or low FOR is desirable since it indicates none of the (often valuable) presences have been ignored in the SDM. For illustration, we chose Bradypus variegatus, a species that has previously been published as an exemplar species for MaxEnt, proposed by Phillips et al. (2006). We used CTs to increasingly refine the species envelope, starting with the whole study region (E0), eliminating more and more potential naughty noughts (E1–E3). When combined with an SDM fit within the species envelope, the best CT SDM had similar AUC and FPR to the best MaxEnt SDM, but otherwise performed better. The FNR and FOR were greatly reduced, suggesting that CTs handle absences better. Interestingly, MaxEnt predictions showed low discriminatory performance, with the most common predicted probability of presence being in the same range (0.00-0.20) for both true absences and presences. In summary, this example shows that SDMs can be improved by introducing an initial hurdle to identify naughty noughts and partition the envelope before applying SDMs. This improvement was barely detectable via AUC and FPR yet visible in FOR, FNR, and the comparison of predicted probability of presence distribution for pres/absence.

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The average population age has been increasing for decades. In the U.S., the history of retirement communities in some states is relatively long, reaching back to the 1920s. In Finland, with one of the fastest-growing elderly population and highest total dependency ratios, seniors housing is a relatively new market within the residential housing business. Some studies have reported that only a small percentage of seniors are willing to move into age-restricted communities in Finland. This study analyzes awareness and attitudes of Finnish people toward age-restricted housing for seniors and toward seniors living in these communities. The results show that the majority of Finns were undecided if “senior houses” were the same as assisted living facilities. The respondents associated age-restricted communities with institutional housing for lonely elderly people with illnesses. The results of this study will help investors and developers understand how potential customers see age-restricted housing for seniors. Also, managers of senior houses can use the results for clarifying the idea of senior houses.

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In australia, 'Aboriginality' is often defined by people in constrictive ways that are heavily influenced by the coloniser's epistemological frameworks. An essential component of this is a 'racial' categorisation of peoples that marks sameness and difference, thereby influencing insider and outsider status. In one sense, this categorisation of people acts to exclude non-aboriginal 'others' from participation in preinvasion indigenous ontologies, ways of living that may not have contained such restrictive identity categories and were thereby highly inclusive of outsiders. One of the effects of this is that aboriginal peoples' efforts for 'advancement' - either out of 'disadvantage' and/or towards political independence (ie, sovereignty) - become confined and restricted by what is deemed possible within the coloniser's epistemological frameworks. This is so much so that aboriginal people are at risk of only reinforcing and upholding the very systems that resulted in their original and continuing dispossession.

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Theories of search and search behavior can be used to glean insights and generate hypotheses about how people interact with retrieval systems. This paper examines three such theories, the long standing Information Foraging Theory, along with the more recently proposed Search Economic Theory and the Interactive Probability Ranking Principle. Our goal is to develop a model for ad-hoc topic retrieval using each approach, all within a common framework, in order to (1) determine what predictions each approach makes about search behavior, and (2) show the relationships, equivalences and differences between the approaches. While each approach takes a different perspective on modeling searcher interactions, we show that under certain assumptions, they lead to similar hypotheses regarding search behavior. Moreover, we show that the models are complementary to each other, but operate at different levels (i.e., sessions, patches and situations). We further show how the differences between the approaches lead to new insights into the theories and new models. This contribution will not only lead to further theoretical developments, but also enables practitioners to employ one of the three equivalent models depending on the data available.

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Overview This review of research conducted with supported playgroups was prepared for the Queensland Department of Education, Training and Employment (DETE). The report provides a synthesis of the research on the effectiveness of supported playgroups to improve child, parent, and community outcomes and to identify key features of supported playgroups that support effective outcomes. Supported playgroups are community-based services that provide a low intensity parenting intervention, through regular group sessions for parent-child dyads. Supported playgroups target vulnerable families who may benefit from parenting support. Supported playgroups have common goals to enhance children’s early learning and parental wellbeing. Method A search strategy was devised to identify research studies, nationally and internationally, that involved parent-child group programs for families with young children, delivered under the leadership of an employed facilitator. Academic databases and other data sources were explored for studies conducted in the period from 2004 to 2014. Summary descriptions of the research studies were developed; assessment of research methodologies was made; research evidence on the effectiveness of supported playgroups to improve child, parent, and community outcomes was identified; and comparative analyses of the implementation features of supported playgroups were completed. Findings The search strategy identified 34 research publications, reporting on 29 different programs. Twenty-six of the studies report on research conducted in Australia and eight reported on research conducted in other countries, including the United Kingdom, Canada, and the United States. Three clusters of playgroups were identified: Category 1 - Standard supported playgroups; Category 2 - Mobile playgroups; Category 3 – Supported playgroups with specific interventions. The research studies identified encompassed experimental and non-experimental research designs. The studies of standard supported playgroups and mobile playgroups were most often qualitative studies and modest in scale, in terms of the number of research participants. Experimental and quasi-experimental research designs characterised the studies identified in the category of supported playgroups with specific interventions. Overall, the research studies that were categorised as supported playgroups with specific interventions provided stronger evidence for effectiveness to improve parental behaviour in ways that are known to support children’s early developmental competence. Qualitative studies, including case studies and ethnographic research, documented important features of program delivery, such as the importance of facilitators’ interpersonal skills to positive experiences for families in the playgroups; as well as the important opportunities that the playgroups afforded to vulnerable families to reduce social isolation. Conclusions The potential for supported playgroups to improve a broad range of learning and psychosocial outcomes for children and parents was suggested by many of the research studies. However, the nature of the research designs employed means that it is not possible to conclude that there is strong evidence of the impact of supported playgroups on child, parent, and community outcomes. The qualitative studies did provide rich descriptions about the implementation processes of playgroups and also captured the variability in the delivery of the playgroups in terms of who participated, local contextual factors that impacted on the playgroup experiences, and the nature of the experiences of parents within the playgroups. Research methodologies need to be employed that address the limitations of the studies to date. This would provide more defensible evidence that supported playgroups have an impact over time on outcomes for children, families, and communities. Overall, this area of research remains relatively under-evaluated in terms of rigorous research designs. The identified research studies point to some promising research directions but do not yet enable strong claims to be made about the effectiveness of the standard playgroup or mobile playgroup models to impact on parenting outcomes. Data collected from interview and survey methodologies clearly identifies that supported playgroups are highly acceptable to families. Given the popularity of supported playgroups to engage families across diverse communities, and the reported high levels of satisfaction and benefits identified within many of the research studies, it is clear that the provision of supported playgroups is fulfilling an important community need by providing support to parents with young children. However, there is a need to strengthen the evidence base that supported playgroups are an effective early parenting intervention that improves outcomes for children, parents, and communities.

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At the 2014 G20 held in Brisbane, Australia took the position that climate change is not an economic issue. Most others thought it was - especially the Turkish Prime Minister who is hosting the 2015 G20. It is certainly an economic issue. But, it is not just an economic issue - either in the source or the solution.

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Loading margin sensitivity (LMS) has been widely used in applications in the realm of voltage stability assessment and control. Typically, LMS is derived based on system equilibrium equations near bifurcation and therefore requires full detailed system model and significant computation effort. Availability of phasor measurement units (PMUs) due to the recent development of wide-area monitoring system (WAMS) provides an alternative computation-friendly approach for calculating LMS. With such motivation, this work proposes measurement-based wide-area loading margin sensitivity (WALMS) in bulk power systems. The proposed sensitivity, with its simplicity, has great potential to be embedded in real-time applications. Moreover, the calculation of the WALMS is not limited to low voltage near bifurcation point. A case study on IEEE 39-bus system verifies the proposed sensitivity. Finally, a voltage control scenario demonstrates the potential application of the WALMS.

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The highly complex disorder of chronic wounds is a significant problem. Information is often lacking, dynamically changing, or contradictory and thus acts to impede the progression of research and its translation into clinical care. Transdisciplinary collaboration may play an important role in chronic wound research, permitting key stakeholders with a single, central goal to take a unified approach towards addressing the problem. While transdisciplinary collaboration is not a new concept, its implementation within chronic wound research is relatively new. This is because the research area is still largely dominated by single-discipline researchers or by multiple disciplines working in isolation. Transdisciplinary research is a transcending approach, requiring a greater level of understanding between disciplines and may represent the next leap forward in wound care research. This approach necessitates a deeper understanding by all team members of the co-disciplines involved; where key stakeholders are better equipped to respond to dynamic changes and problems that arise in chronic wound research. In this paper, we illustrate what a transdisciplinary approach in wound care research may entail, with the ultimate goal of such an undertaking to improve understanding of the complexities of wound care, which could lead to potential benefits in wound management.

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BACKGROUND: Genetic variation contributes to the risk of developing endometriosis. This review summarizes gene mapping studies in endometriosis and the prospects of finding gene pathways contributing to disease using the latest genome-wide strategies. METHODS: To identify candidate-gene association studies of endometriosis, a systematic literature search was conducted in PubMed of publications up to 1 April 2008, using the search terms 'endometriosis' plus 'allele' or 'polymorphism' or 'gene'. Papers included were those with information on both case and control selection, showed allelic and/or genotypic results for named germ-line polymorphisms and were published in the English language. RESULTS: Genetic variants in 76 genes have been examined for association, but none shows convincing evidence of replication in multiple studies. There is evidence for genetic linkage to chromosomes 7 and 10, but the genes (or variants) in these regions contributing to disease risk have yet to be identified. Genome-wide association is a powerful method that has been successful in locating genetic variants contributing to a range of common diseases. Several groups are planning these studies in endometriosis. For this to be successful, the endometriosis research community must work together to genotype sufficient cases, using clearly defined disease classifications, and conduct the necessary replication studies in several thousands of cases and controls. CONCLUSIONS: Genes with convincing evidence for association with endometriosis are likely to be identified in large genome-wide studies. This will provide a starting point for functional and biological studies to develop better diagnosis and treatment for this debilitating disease.

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This research is a step forward in discovering knowledge from databases of complex structure like tree or graph. Several data mining algorithms are developed based on a novel representation called Balanced Optimal Search for extracting implicit, unknown and potentially useful information like patterns, similarities and various relationships from tree data, which are also proved to be advantageous in analysing big data. This thesis focuses on analysing unordered tree data, which is robust to data inconsistency, irregularity and swift information changes, hence, in the era of big data it becomes a popular and widely used data model.

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Long-term unemployment of older people can have severe consequences for individuals, communities and ultimately economies, and is therefore a serious concern in countries with an ageing population. However, the interplay of chronological age and other individual difference characteristics in predicting older job seekers' job search is so far not well understood. This study investigated relationships among age, proactive personality, occupational future time perspective (FTP) and job search intensity of 182 job seekers between 43 and 77 years in Australia. Results were mostly consistent with expectations based on a combination of socio-emotional selectivity theory and the notion of compensatory psychological resources. Proactive personality was positively related to job search intensity and age was negatively related to job search intensity. Age moderated the relationship between proactive personality and job search intensity, such that the relationship was stronger at higher compared to lower ages. One dimension of occupational FTP (perceived remaining time left in the occupational context) mediated this moderating effect, but not the overall relationship between age and job search intensity. Implications for future research, including the interplay of occupational FTP and proactive personality, and some tentative practical implications are discussed.

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It has been argued that transition points in life, such as the approach towards, and early years of retirement present key opportunities for interventions to improve the health of the population. Research has also highlighted inequalities in health status in the retired population and in response to interventions which should be addressed. We aimed to conduct a systematic review to synthesise international evidence on the types and effectiveness of interventions to increase physical activity among people around the time of retirement. A systematic review of literature was carried out between February 2014 and April 2015. Searches were not limited by language or location, but were restricted by date to studies published from 1990 onwards. Methods for identification of relevant studies included electronic database searching, reference list checking, and citation searching. Systematic search of the literature identified 104 papers which described study populations as being older adults. However, we found only one paper which specifically referred to their participants as being around the time of retirement. The intervention approaches for older adults encompassed: training of health care professionals; counselling and advice giving; group sessions; individual training sessions; in-home exercise programmes; in-home computer-delivered programmes; in-home telephone support; in-home diet and exercise programmes; and community-wide initiatives. The majority of papers reported some intervention effect, with evidence of positive outcomes for all types of programmes. A wide range of different measures were used to evaluate effectiveness, many were self-reported and few studies included evaluation of sedentary time. While the retirement transition is considered a significant point of life change, little research has been conducted to assess whether physical activity interventions at this time may be effective in promoting or maintaining activity, or reducing health inequalities. We were unable to find any evidence that the transition to retirement period was, or was not a significant point for intervention. Studies in older adults more generally indicated that a range of interventions might be effective for people around retirement age.

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Introduction The last half-century of epidemiological enquiry into schizophrenia can be characterized by the search for neurological imbalances and lesions for genetic factors. The growing consensus is that these directions have failed, and there is now a growing interest in psychosocial and developmental models. Another area of recent interest is in epigenetics – the multiplication of genetic influences by environmental factors. Methods This integrative review comparatively maps current psychosocial, developmental and epigenetic models for schizophrenia epidemiology to identify crossover and theoretical gaps. Results In the flood of data that is being produced around the schizophrenia epidemiology, one of the most consistent findings is that schizophrenia is an urban syndrome. Once demographic factors have been discounted, between one-quarter and one-third of all incidence is repeatedly traced back to urbanicity – potentially threatening more established models, such as the psychosocial, genetic and developmental hypotheses. Conclusions Close analysis demonstrates how current models for schizophrenia epidemiology appear to miss the mark. Furthermore, the built environment appears to be an inextricable factor in all current models and indeed may be a valid epidemiological factor on its own. The reason the built environment hasn’t already become a de rigueur area of epidemiological research is possibly trivial – it just doesn’t attract enough science, and lacks a hero to promote it alongside other hypotheses.