988 resultados para Current loop


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We present a method for topological SLAM that specifically targets loop closing for edge-ordered graphs. Instead of using a heuristic approach to accept or reject loop closing, we propose a probabilistically grounded multi-hypothesis technique that relies on the incremental construction of a map/state hypothesis tree. Loop closing is introduced automatically within the tree expansion, and likely hypotheses are chosen based on their posterior probability after a sequence of sensor measurements. Careful pruning of the hypothesis tree keeps the growing number of hypotheses under control and a recursive formulation reduces storage and computational costs. Experiments are used to validate the approach.

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Troubled dynamics between residents of an Aboriginal town in Queensland and the local health system were established during colonisation and consolidated during those periods of Australian history where the policies of 'protection' (segregation), integration and then assimilation held sway. The status of Aboriginal health is, in part, related to interactions between the residents' current and historical experiences of the health and criminal justice systems as together these agencies used medical and moral policing to legitimate dispossession, marginalisation, institutionalisation and control of the residents. The punitive regulations and ethnocentric strategies used by these institutions are within the living memory of many of the residents or in the published accounts of preceding generations. This paper explores current residents' memories and experiences.

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Mock circulation loops are used to evaluate the performance of cardiac assist devices prior to animal and clinical testing. A compressible, translucent silicone ventricle chamber that mimics the exact size, shape and motion of a failing heart is desired to assist in flow visualization studies around inflow cannulae during VAD support. The aim of this study was therefore to design and construct a naturally shaped flexible left ventricle and evaluate its performance in a mock circulation loop. The ventricle shape was constructed by the use of CT images taken from a patient experiencing cardiomyopathic heart failure and used to create a 3D image and subsequent mould to produce a silicone ventricle. Different cardiac conditions were successfully simulated to validate the ventricle performance, including rest, left heart failure and VAD support.

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Off-site manufacture (OSM) offers numerous benefits to all parties in the construction process. The uptake of OSM in Australia has, however, been limited. This limited uptake corresponds to similar trends in the UK and US, although the level of OSM there appears to be increasing. This project undertook three workshops — one each in Victoria, Queensland and Western Australia — and 18 interviews with key stakeholders to assist in identifying the general benefits and barriers to OSM uptake in the Australian construction industry. Seven case studies were also undertaken, involving construction projects that used OSM, ranging from civil projects through to residential. Each of these case studies has been analysed to identify what worked and what didn’t, and suggest the lessons to be learned from each project.

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The distribution network reliability can be increased if distributed generators (DGs) are allowed to operate in both grid-connected and islanded operations when the network has a high DG penetration level. However, the current utility regulations do not allow for the islanded operation. The arc faults are the one of the major issues preventing the islanded operation, since the arc will not extinguish if the DGs are not disconnected. In this paper, the effect of a converter interfaced DG on an arc fault is investigated by considering different control strategies for the converter. The foldback current control characteristic is proposed to a converter interfaced DG to achieve quick arc extinction and self-restoration without disconnecting the DG in the event of an arc fault. The results are validated through PSCAD/EMTDC simulations.

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The multi-level current reinjection concept described in literature is well-known to produce high quality AC current waveforms in high power and high voltage self-commutating current source converters. This paper proposes a novel reinjection circuitry which is capable of producing a 7-level reinjection current. It is shown that this reinjection current effectively increases the pulse number of the converter to 72. The use of PSCAD/EMTDC simulation validates the functionality of the proposed concept illustrating its effectiveness on both AC and DC sides of the converter.

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Over the past 20 years the nature of rural valuation practice has required most rural valuers to undertake studies in both agriculture (farm management) and valuation, especially if carrying out valuation work for financial institutions. The additional farm financial and management information obtained by rural valuers exceeds that level of information required to value commercial, retail and industrial by the capitalisation of net rent/profit valuation method and is very similar to the level of information required for the valuation of commercial and retail property by the Discounted Cash Flow valuation method. On this basis the valuers specialising in rural valuation practice have the necessary skills and information to value rural properties by an income valuation method, which can focus on the long term environmental and economic sustainability of the property being valued. This paper will review the results of an extensive survey carried out by rural property valuers in Australia, in relation to the impact of farm management on rural property values and sustainable rural land use. A particular focus of the research relates to the increased awareness of the problems of rural land degradation in Australia and the subsequent impact such problems have on the productivity of rural land. These problems of sustainable land use have resulted in the need to develop an approach to rural valuation practice that allows the valuer to factor the past management practices on the subject rural property into the actual valuation figure. An analysis of the past farm management and the inclusion of this data into the valuation methodology provides a much more reliable indication of farm sustainable economic value than the existing direct comparison valuation methodology.

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Substance misuse in people with serious mental disorders is common and has a wideranging negative impact. The multiplicity of problems suggests that this comorbidity is better conceptualized as a type of complex disorder than by ‘dual diagnosis’. Problems with sequential and parallel treatments have led to the development of integrated approaches, with one practitioner or team addressing both the substance use and mental disorder. These treatments are typically characterized by motivation enhancement, minimizing treatment-related stress, emphasizing harm reduction as well as abstinence, and assertive outreach. A review of published randomized trials demonstrates that superior effects to controls are rarely consistent across treatment foci and over time. While motivational interventions assist engagement, more intervention is usually required for integrated treatment programs to improve long-term outcomes more than control conditions. More intensive case management does not consistently improve impact, but extended cognitive-behavioral therapies have promise. Suggestions for maximizing treatment effects and improving research evidence are provided.

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This paper presents an Active Gate Signaling scheme to reduce voltage/current spikes across insulated gate power switches in hard switching power electronic circuits. Voltage and/or current spikes may cause EMI noise. In addition, they increase voltage/current stress on the switch. Traditionally, a higher gate resistance is chosen to reduce voltage/current spikes. Since the switching loss will increase remarkably, an active gate voltage control scheme is developed to improve efficiency of hard switching circuits while the undesirable voltage and/or current spikes are minimized.

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A Positive Buck- Boost (PBB) converter is a known DC-DC converter that can operate in step up and step down modes. Unlike Buck, Boost, and Inverting Buck Boost converters, the inductor current of a PBB can be controlled independently of its voltage conversion ratio. In other words, the inductor of PBB can be utilised as an energy storage unit in addition to its main function of energy transfer. In this paper, the capability of PBB to store energy has been utilised to achieve robustness against input voltage fluctuations and output current changes. The control strategy has been developed to keep accuracy, affordability, and simplicity acceptable. To improve the efficiency of the system a Smart Load Controller (SLC) has been suggested. Applying SLC extra current storage occurs when there is sudden loads change otherwise little extra current is stored.

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This paper provides much needed consolidation of the available evidence in relation to the design and evaluation of road safety advertising messages. Drawing upon current knowledge, the paper identifies some key challenges for improving both the persuasiveness of messages and the methods utilised to assess their effectiveness. The paper identifies some key message-related and individual difference factors, such as response efficacy, emotion, gender and involvement, which theoretical and empirical evidence has shown to be key determinants of message persuasiveness. In relation to message evaluation, the paper focuses upon research relating to the direct, persuasive role of advertising as opposed to evaluations of the combined effects of advertising and enforcement. The paper reviews methodological limitations of previous studies and gaps in existing knowledge that together limit the ability to draw accurate and comprehensive conclusions regarding message effectiveness. Overall, this paper provides a significant and timely review of what is currently known about road safety advertising design and evaluation.

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Despite the advances that have been made in relation to the valuation of Commercial, Industrial and retail property, there has not been the same progress in relation to the valuation of rural property. Although number of rural property valuations also require the valuer to carry out a full analysis of the economic performance of the farming operations, as well as the long term environmental viability of the farm, this information is rarely used to assess the value of the property, nor is it even used for a secondary valuation method. Over the past 20 years the nature of rural valuation practice has required most rural valuers to undertake studies in both agriculture (farm management) and valuation, especially if carrying out valuation work for financial institutions. The additional farm financial and management information obtained by rural valuers exceeds that level of information required to value commercial, retail and industrial by the capitalisation of net rent/profit valuation method and is very similar to the level of information required for the valuation of commercial and retail property by the Discounted Cash Flow valuation method. On this basis the valuers specialising in rural valuation practice have the necessary skills and information to value rural properties by an income valuation method. Although the direct comparison method of valuation has been sufficient in the past to value rural properties the future use of the method as the main valuation method is limited and valuers need to adopt an income valuation method as at least a secondary valuation method to overcome the problems associated with the use of direct comparison as the only rural property valuation method, especially in view of the impact that farm technical, financial and environmental .management can have on rural property values. This paper will review the results of an extensive survey carried out by rural property valuers and agribusiness managers in NSW, in relation to the impact of farm management on rural property values and rural property valuation practice.

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This paper presents a model to estimate travel time using cumulative plots. Three different cases considered are i) case-Det, for only detector data; ii) case-DetSig, for detector data and signal controller data and iii) case-DetSigSFR: for detector data, signal controller data and saturation flow rate. The performance of the model for different detection intervals is evaluated. It is observed that detection interval is not critical if signal timings are available. Comparable accuracy can be obtained from larger detection interval with signal timings or from shorter detection interval without signal timings. The performance for case-DetSig and for case-DetSigSFR is consistent with accuracy generally more than 95% whereas, case-Det is highly sensitive to the signal phases in the detection interval and its performance is uncertain if detection interval is integral multiple of signal cycles.

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Aims: To assess the effectiveness of current treatment approaches to assist benzodiazepine discontinuation. Methods: A systematic review of approaches to benzodiazepine discontinuation in general practice and out-patient settings was undertaken. Routine care was compared with three treatment approaches: brief interventions, gradual dose reduction (GDR) and psychological interventions. GDR was compared with GDR plus psychological interventions or substitutive pharmacotherapies. Results: Inclusion criteria were met by 24 studies, and a further eight were identified by future search. GDR [odds ratio (OR) = 5.96, confidence interval (CI) = 2.08–17.11] and brief interventions (OR = 4.37, CI = 2.28–8.40) provided superior cessation rates at post-treatment to routine care. Psychological treatment plus GDR were superior to both routine care (OR = 3.38, CI = 1.86–6.12) and GDR alone (OR = 1.82, CI = 1.25–2.67). However, substitutive pharmacotherapies did not add to the impact of GDR (OR = 1.30, CI = 0.97– 1.73), and abrupt substitution of benzodiazepines by other pharmacotherapy was less effective than GDR alone (OR = 0.30, CI = 0.14–0.64). Few studies on any technique had significantly greater benzodiazepine discontinuation than controls at follow-up. Conclusions: Providing an intervention is more effective than routine care. Psychological interventions may improve discontinuation above GDR alone. While some substitutive pharmacotherapies may have promise, current evidence is insufficient to support their use.

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Crucial to enhancing the status and quality of games teaching in schools is a developed understanding of the teaching strategies adopted by practitioners. In this paper, we will demonstrate that contemporary games‟ teaching is a product of individual, task and environmental constraints (Newell, 1986). More specifically, we will show that current pedagogy in the U.K., Australia and the United States is strongly influenced by historical, socio-cultural environmental and political constraints. In summary, we will aim to answer the question „why do teachers teach games the way they do.‟ In answering this question, we conclude that teacher educators, who are trying to influence pedagogical practice, must understand these potential constraints and provide appropriate pre-service experiences to give future physical education teachers the knowledge, confidence and ability to adopt a range of teaching styles when they become fully fledged teachers. Essential to this process is the need to enable future practitioners to base their pedagogical practice on a sound understanding of contemporary learning theories of skill acquisition.