886 resultados para Localization real-world challenges
Resumo:
Airports and cities inevitably recognise the value that each brings the other; however, the separation in decision-making authority for what to build, where, when and how provides a conundrum for both parties. Airports often want a say in what is developed outside of the airport fence, and cities often want a say in what is developed inside the airport fence. Defining how much of a say airports and cities have in decisions beyond their jurisdictional control is likely to be a topic that continues so long as airports and cities maintain separate formal decision-making processes for what to build, where, when and how. However, the recent Green and White Papers for a new National Aviation Policy have made early inroads to formalising relationships between Australia’s major airports and their host cities. At present, no clear indication (within practice or literature) is evident to the appropriateness of different governance arrangements for decisions to develop in situations that bring together the opposing strategic interests of airports and cities; thus leaving decisions for infrastructure development as complex decision-making spaces that hold airport and city/regional interests at stake. The line of enquiry is motivated by a lack of empirical research on networked decision-making domains outside of the realm of institutional theorists (Agranoff & McGuire, 2001; Provan, Fish & Sydow, 2007). That is, governance literature has remained focused towards abstract conceptualisations of organisation, without focusing on the minutia of how organisation influences action in real-world applications. A recent study by Black (2008) has provided an initial foothold for governance researchers into networked decision-making domains. This study builds upon Black’s (2008) work by aiming to explore and understand the problem space of making decisions subjected to complex jurisdictional and relational interdependencies. That is, the research examines the formal and informal structures, relationships, and forums that operationalise debates and interactions between decision-making actors as they vie for influence over deciding what to build, where, when and how in airport-proximal development projects. The research mobilises a mixture of qualitative and quantitative methods to examine three embedded cases of airport-proximal development from a network governance perspective. Findings from the research provide a new understanding to the ways in which informal actor networks underpin and combine with formal decision-making networks to create new (or realigned) governance spaces that facilitate decision-making during complex phases of development planning. The research is timely, and responds well to Isett, Mergel, LeRoux, Mischen and Rethemeyer’s (2011) recent critique of limitations within current network governance literature, specifically to their noted absence of empirical studies that acknowledge and interrogate the simultaneity of formal and informal network structures within network governance arrangements (Isett et al., 2011, pp. 162-166). The combination of social network analysis (SNA) techniques and thematic enquiry has enabled findings to document and interpret the ways in which decision-making actors organise to overcome complex problems for planning infrastructure. An innovative approach to using association networks has been used to provide insights to the importance of the different ways actors interact with one another, thus providing a simple yet valuable addition to the increasingly popular discipline of SNA. The research also identifies when and how different types of networks (i.e. formal and informal) are able to overcome currently known limitations to network governance (see McGuire & Agranoff, 2011), thus adding depth to the emerging body of network governance literature surrounding limitations to network ways of working (i.e. Rhodes, 1997a; Keast & Brown, 2002; Rethemeyer & Hatmaker, 2008; McGuire & Agranoff, 2011). Contributions are made to practice via the provision of a timely understanding of how horizontal fora between airports and their regions are used, particularly in the context of how they reframe the governance of decision-making for airport-proximal infrastructure development. This new understanding will enable government and industry actors to better understand the structural impacts of governance arrangements before they design or adopt them, particularly for factors such as efficiency of information, oversight, and responsiveness to change.
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A significant issue encountered when fusing data received from multiple sensors is the accuracy of the timestamp associated with each piece of data. This is particularly important in applications such as Simultaneous Localisation and Mapping (SLAM) where vehicle velocity forms an important part of the mapping algorithms; on fastmoving vehicles, even millisecond inconsistencies in data timestamping can produce errors which need to be compensated for. The timestamping problem is compounded in a robot swarm environment due to the use of non-deterministic readily-available hardware (such as 802.11-based wireless) and inaccurate clock synchronisation protocols (such as Network Time Protocol (NTP)). As a result, the synchronisation of the clocks between robots can be out by tens-to-hundreds of milliseconds making correlation of data difficult and preventing the possibility of the units performing synchronised actions such as triggering cameras or intricate swarm manoeuvres. In this thesis, a complete data fusion unit is designed, implemented and tested. The unit, named BabelFuse, is able to accept sensor data from a number of low-speed communication buses (such as RS232, RS485 and CAN Bus) and also timestamp events that occur on General Purpose Input/Output (GPIO) pins referencing a submillisecondaccurate wirelessly-distributed "global" clock signal. In addition to its timestamping capabilities, it can also be used to trigger an attached camera at a predefined start time and frame rate. This functionality enables the creation of a wirelessly-synchronised distributed image acquisition system over a large geographic area; a real world application for this functionality is the creation of a platform to facilitate wirelessly-distributed 3D stereoscopic vision. A ‘best-practice’ design methodology is adopted within the project to ensure the final system operates according to its requirements. Initially, requirements are generated from which a high-level architecture is distilled. This architecture is then converted into a hardware specification and low-level design, which is then manufactured. The manufactured hardware is then verified to ensure it operates as designed and firmware and Linux Operating System (OS) drivers are written to provide the features and connectivity required of the system. Finally, integration testing is performed to ensure the unit functions as per its requirements. The BabelFuse System comprises of a single Grand Master unit which is responsible for maintaining the absolute value of the "global" clock. Slave nodes then determine their local clock o.set from that of the Grand Master via synchronisation events which occur multiple times per-second. The mechanism used for synchronising the clocks between the boards wirelessly makes use of specific hardware and a firmware protocol based on elements of the IEEE-1588 Precision Time Protocol (PTP). With the key requirement of the system being submillisecond-accurate clock synchronisation (as a basis for timestamping and camera triggering), automated testing is carried out to monitor the o.sets between each Slave and the Grand Master over time. A common strobe pulse is also sent to each unit for timestamping; the correlation between the timestamps of the di.erent units is used to validate the clock o.set results. Analysis of the automated test results show that the BabelFuse units are almost threemagnitudes more accurate than their requirement; clocks of the Slave and Grand Master units do not di.er by more than three microseconds over a running time of six hours and the mean clock o.set of Slaves to the Grand Master is less-than one microsecond. The common strobe pulse used to verify the clock o.set data yields a positive result with a maximum variation between units of less-than two microseconds and a mean value of less-than one microsecond. The camera triggering functionality is verified by connecting the trigger pulse output of each board to a four-channel digital oscilloscope and setting each unit to output a 100Hz periodic pulse with a common start time. The resulting waveform shows a maximum variation between the rising-edges of the pulses of approximately 39¥ìs, well below its target of 1ms.
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Reliable ambiguity resolution (AR) is essential to Real-Time Kinematic (RTK) positioning and its applications, since incorrect ambiguity fixing can lead to largely biased positioning solutions. A partial ambiguity fixing technique is developed to improve the reliability of AR, involving partial ambiguity decorrelation (PAD) and partial ambiguity resolution (PAR). Decorrelation transformation could substantially amplify the biases in the phase measurements. The purpose of PAD is to find the optimum trade-off between decorrelation and worst-case bias amplification. The concept of PAR refers to the case where only a subset of the ambiguities can be fixed correctly to their integers in the integer least-squares (ILS) estimation system at high success rates. As a result, RTK solutions can be derived from these integer-fixed phase measurements. This is meaningful provided that the number of reliably resolved phase measurements is sufficiently large for least-square estimation of RTK solutions as well. Considering the GPS constellation alone, partially fixed measurements are often insufficient for positioning. The AR reliability is usually characterised by the AR success rate. In this contribution an AR validation decision matrix is firstly introduced to understand the impact of success rate. Moreover the AR risk probability is included into a more complete evaluation of the AR reliability. We use 16 ambiguity variance-covariance matrices with different levels of success rate to analyse the relation between success rate and AR risk probability. Next, the paper examines during the PAD process, how a bias in one measurement is propagated and amplified onto many others, leading to more than one wrong integer and to affect the success probability. Furthermore, the paper proposes a partial ambiguity fixing procedure with a predefined success rate criterion and ratio-test in the ambiguity validation process. In this paper, the Galileo constellation data is tested with simulated observations. Numerical results from our experiment clearly demonstrate that only when the computed success rate is very high, the AR validation can provide decisions about the correctness of AR which are close to real world, with both low AR risk and false alarm probabilities. The results also indicate that the PAR procedure can automatically chose adequate number of ambiguities to fix at given high-success rate from the multiple constellations instead of fixing all the ambiguities. This is a benefit that multiple GNSS constellations can offer.
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Middle schooling is a crucial area of education where adolescents experiencing physiological and psychological hanges require expert guidance. As more research evidence is provided about adolescent learning, teachers are considered pivotal to adolescents’ educational development. The two levels of implementing reform measures need to be targeted, that is, at the inservice and preservice teacher levels. This quantitative study employs a 40-item, five-part Likert scale survey to understand preservice teachers’ (n=142) perceptions of their confidence to teach in the middle school at the conclusion of their tertiary education. The survey instrument was developed from the literature with connections to the Queensland College of Teachers professional standards. Results indicated that they perceived themselves as capable of creating a positive classroom environment with seven items greater than 80%, except with behaviour management (<80% for two items) and they considered their pedagogical knowledge to be adequate (i.e., 7 out of 8 items >84%). Items associated with implementing middle schooling curriculum had varied responses (e.g., implementing literacy and numeracy were 74% while implementing learning with real-world connections was 91%). This information may assist coursework designers. For example, if significant percentages of preservice teachers indicate they believe they were not well prepared for assessment and reporting in the middle school then course designers can target these areas more effectively.
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Distributed Genetic Algorithms (DGAs) designed for the Internet have to take its high communication cost into consideration. For island model GAs, the migration topology has a major impact on DGA performance. This paper describes and evaluates an adaptive migration topology optimizer that keeps the communication load low while maintaining high solution quality. Experiments on benchmark problems show that the optimized topology outperforms static or random topologies of the same degree of connectivity. The applicability of the method on real-world problems is demonstrated on a hard optimization problem in VLSI design.
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Purpose Anecdotal evidence suggests that some sunglass users prefer yellow tints for outdoor activities, such as driving, and research has suggested that such tints improve the apparent contrast and brightness of real-world objects. The aim of this study was to establish whether yellow filters resulted in objective improvements in performance for visual tasks relevant to driving. Methods Response times of nine young (age [mean ± SD], 31.4 ± 6.7 years) and nine older (age, [mean ± SD], 74.6 ± 4.8) adults were measured using video presentations of traffic hazards (driving hazard perception task) and a simple low-contrast grating appeared at random peripheral locations on a computer screen. Response times were compared when participants wore a yellow filter (with and without a linear polarizer) versus a neutral density filter (with and without a linear polarizer). All lens combinations were matched to have similar luminance transmittances (˜27%). Results In the driving hazard perception task, the young but not the older participants responded significantly more rapidly to hazards when wearing a yellow filter than with a luminance-matched neutral density filter (mean difference, 450 milliseconds). In the low-contrast grating task, younger participants also responded more quickly for the yellow filter condition but only when combined with a polarizer. Although response times increased with increasing stimulus eccentricity for the low-contrast grating task, for the younger participants, this slowing of response times with increased eccentricity was reduced in the presence of a yellow filter, indicating that perception of more peripheral objects may be improved by this filter combination. Conclusions Yellow filters improve response times for younger adults for visual tasks relevant to driving.
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In this paper, we present WebPut, a prototype system that adopts a novel web-based approach to the data imputation problem. Towards this, Webput utilizes the available information in an incomplete database in conjunction with the data consistency principle. Moreover, WebPut extends effective Information Extraction (IE) methods for the purpose of formulating web search queries that are capable of effectively retrieving missing values with high accuracy. WebPut employs a confidence-based scheme that efficiently leverages our suite of data imputation queries to automatically select the most effective imputation query for each missing value. A greedy iterative algorithm is also proposed to schedule the imputation order of the different missing values in a database, and in turn the issuing of their corresponding imputation queries, for improving the accuracy and efficiency of WebPut. Experiments based on several real-world data collections demonstrate that WebPut outperforms existing approaches.
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This paper introduces PartSS, a new partition-based fil- tering for tasks performing string comparisons under edit distance constraints. PartSS offers improvements over the state-of-the-art method NGPP with the implementation of a new partitioning scheme and also improves filtering abil- ities by exploiting theoretical results on shifting and scaling ranges, thus accelerating the rate of calculating edit distance between strings. PartSS filtering has been implemented within two major tasks of data integration: similarity join and approximate membership extraction under edit distance constraints. The evaluation on an extensive range of real-world datasets demonstrates major gain in efficiency over NGPP and QGrams approaches.
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In this article, we report on the findings of an exploratory study into the experience of undergraduate students as they learn new mathematical models. Qualitative and quanti- tative data based around the students’ approaches to learning new mathematical models were collected. The data revealed that students actively adopt three approaches to under- standing a new mathematical model: gathering information for the task of understanding the model, practising with and using the model, and finding interrelationships between elements of the model. We found that the students appreciate mathematical models that have a real world application and that this can be used to engage students in higher level learning approaches.
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We conducted an exploratory study of a mobile energy monitoring tool: The Dashboard. Our point of departure from prior work was the emphasis of end-user customisation and social sharing. Applying extensive feedback, we deployed the Dashboard in real-world conditions to socially linked research participants for a period of five weeks. Participants were encouraged to devise, construct, place, and view various data feeds. The aim of our study was to test the assumption that participants, having control over their Dashboard configuration, would engage, and remain engaged, with their energy feedback throughout the trial. Our research points to a set of design issues surrounding the adoption and continued use of such tools. A novel finding of our study is the impact of social links between participants and their continued engagement with the Dashboard. Our results also illustrate the emergence of energy-voyeurism, a form of social energy monitoring by peers.
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‘Social innovation’ is a construct increasingly used to explain the practices, processes and actors through which sustained positive transformation occurs in the network society (Mulgan, G., Tucker, S., Ali, R., Sander, B. (2007). Social innovation: What it is, why it matters and how can it be accelerated. Oxford:Skoll Centre for Social Entrepreneurship; Phills, J. A., Deiglmeier, K., & Miller, D. T. Stanford Social Innovation Review, 6(4):34–43, 2008.). Social innovation has been defined as a “novel solution to a social problem that is more effective, efficient, sustainable, or just than existing solutions, and for which the value created accrues primarily to society as a whole rather than private individuals.” (Phills,J. A., Deiglmeier, K., & Miller, D. T. Stanford Social Innovation Review, 6 (4):34–43, 2008: 34.) Emergent ideas of social innovation challenge some traditional understandings of the nature and role of the Third Sector, as well as shining a light on those enterprises within the social economy that configure resources in novel ways. In this context, social enterprises – which provide a social or community benefit and trade to fulfil their mission – have attracted considerable policy attention as one source of social innovation within a wider field of action (see Leadbeater, C. (2007). ‘Social enterprise and social innovation: Strategies for the next 10 years’, Cabinet office,Office of the third sector http://www.charlesleadbeater.net/cms xstandard/social_enterprise_innovation.pdf. Last accessed 19/5/2011.). And yet, while social enterprise seems to have gained some symbolic traction in society, there is to date relatively limited evidence of its real world impacts.(Dart, R. Not for Profit Management and Leadership, 14(4):411–424, 2004.) In other words, we do not know much about the social innovation capabilities and effects of social enterprise. In this chapter, we consider the social innovation practices of social enterprise, drawing on Mulgan, G., Tucker, S., Ali, R., Sander, B. (2007). Social innovation: What it is, why it matters and how can it be accelerated. Oxford: Skoll Centre for Social Entrepreneurship: 5) three dimensions of social innovation: new combinations or hybrids of existing elements; cutting across organisational, sectoral and disciplinary boundaries; and leaving behind compelling new relationships. Based on a detailed survey of 365 Australian social enterprises, we examine their self-reported business and mission-related innovations, the ways in which they configure and access resources and the practices through which they diffuse innovation in support of their mission. We then consider how these findings inform our understanding of the social innovation capabilities and effects of social enterprise,and their implications for public policy development.
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As indicated in a previous Teaching Science article, effective planning for curricula integration requires using standards from two (or more) subject areas (e.g., science and English, science and art or science and mathematics), which also becomes the assessment foci for teaching and learning. Curricula integration of standards into an activity necessitates pedagogical knowledge for developing students’ learning in both subject areas. For science education, the skills and tools for curricula integration include the use of other key learning areas (KLAs). A balance between teacher and student-centred science education programs that draw on democratic processes (e.g., Beane, 1997) can be used to make real-world links to target students’ individual needs. This article presents practical ways to commence thinking about curricula integration towards using Australian curriculum standards.
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There is growing and converging evidence that cannabis may be a major risk factor in people with psychotic disorders and prodromal psychotic symptoms. The lack of available pharmacological treatments for cannabis use indicates that psychological interventions should be a high priority, especially among people with psychotic disorders. However, there have been few randomised controlled trials (RCTs) of psychological interventions among this group. In the present study we critically overview RCTs of psychological and pharmacologic interventions among people with psychotic disorders, giving particular attention to those studies which report cannabis use outcomes. We then review data regarding treatment preferences among this group. RCTs of interventions within "real world" mental health systems among adults with severe mental disorders suggest that cannabis use is amenable to treatment in real world settings among people with psychotic disorders. RCTs of manual guided interventions among cannabis users indicate that while brief interventions are associated with reductions in cannabis use, longer interventions may be more effective. Additionally, RCTs reviewed suggest treatment with antipsychotic medication is not associated with a worsening of cannabis cravings or use and may be beneficial. The development of cannabinoid agonist medication may be an effective strategy for cannabis dependence and suitable for people with psychotic disorders. The development of cannabis use interventions for people with psychotic disorders should also consider patients' treatment preferences. Initial results indicate face-to-face interventions focussed on cannabis use may be preferred. Further research investigating the treatment preferences of people with psychotic disorders using cannabis is needed.
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The aim of this paper is to implement a Game-Theory based offline mission path planner for aerial inspection tasks of large linear infrastructures. Like most real-world optimisation problems, mission path planning involves a number of objectives which ideally should be minimised simultaneously. The goal of this work is then to develop a Multi-Objective (MO) optimisation tool able to provide a set of optimal solutions for the inspection task, given the environment data, the mission requirements and the definition of the objectives to minimise. Results indicate the robustness and capability of the method to find the trade-off between the Pareto-optimal solutions.
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Reviews into teacher education and reform measures, such as implementing professional standards for teachers, are designed to raise the quality of education. Such reviews and reforms also target preservice teachers; hence universities examine their teacher education programs to address these issues, including developing programs that are current with the literature. Over the past fifteen years, concerns have arisen about Australian early adolescents and their disengagement from the schooling system, their “at risk” behaviour and their need for social, emotional and academic support. These concerns have prompted a middle schooling movement in Australia with the literature recognising a need for specialised middle school teachers. As a result, various universities have responded by developing courses specifically designed to graduate teachers who possess the theoretical and pedagogical knowledge for engaging early adolescent learners. This mixed-method study analysed the responses of preservice teachers from three universities across two states in Australia near the completion of their middle years teacher preparation program. The three aims of the study were to: (1) investigate final-year preservice teachers’ perceptions of their confidence to teach in the middle years of schooling; (2) analyse the experiences included in their teacher preparation course that made them feel confident; and (3) describe strategies for enhancing middle schooling teacher education preparation. Data were gathered from final-year preservice teachers (n=142) using a survey that was developed in response to middle schooling literature and the Professional Standards for Queensland Teachers (Queensland College of Teachers, 2006). A questionnaire collected extended information about the participants’ (n=142) experiences that made them feel confident. It also gathered information about strategies for enhancing middle years teacher preparation. One-to-one, 45-minute interviews (n=10) were conducted to elicit in-depth responses aligned with the research aims. Quantitative results indicated that the majority of preservice teachers (n=142) claimed confidence associated with survey items relating to creating a positive classroom environment (range: 70-97%), developing positive relationships for teaching (71-98%), pedagogical knowledge for teaching (72-95%), and implementation of teaching (70-91%). Qualitative findings suggested that the experiences that assisted them to be confident for teaching were practicum and associated field studies coursework, a positive mentor teacher, specifically designed middle years subjects, the pedagogical approaches of university staff, and other real-world experiences such as volunteering in schools and participating in professional development alongside their mentors. This study demonstrated that universities presenting middle years teacher preparation need to consider: the quality of the practicum experience; the suitability of mentor teachers; the significance and practicalities of middle years subjects; university lecturers’ modelling of pedagogical practices; and the inclusion of real-world learning experiences. Although the findings of this study provided evidence as to how preservice teacher confidence for teaching has been influenced by their middle schooling teacher preparation, further research is required to investigate how confidence translates into practice within their first years of teaching.