888 resultados para Nenets Autonomous okrug
Resumo:
There is an increased interested in Uninhabited Aerial Vehicle (UAV) operations and research into advanced methods for commanding and controlling multiple heterogeneous UAVs. Research into areas of supervisory control has rapidly increased. Past research has investigated various approaches of autonomous control and operator limitation to improve mission commanders' Situation Awareness (SA) and cognitive workload. The aim of this paper is to address this challenge through a visualisation framework of UAV information constructed from Information Abstraction (IA). This paper presents the concept and process of IA, and the visualisation framework (constructed using IA), the concept associated with the Level Of Detail (LOD) indexing method, the visualisation of an example of the framework. Experiments will test the hypothesis that, the operator will be able to achieve increased SA and reduced cognitive load with the proposed framework.
Resumo:
This paper presents the application of a monocular visual SLAMon a fixed-wing small Unmanned Aerial System (sUAS) capable of simultaneous estimation of aircraft pose and scene structure. We demonstrate the robustness of unconstrained vision alone in producing reliable pose estimates of a sUAS, at altitude. It is ultimately capable of online state estimation feedback for aircraft control and next-best-view estimation for complete map coverage without the use of additional sensors.We explore some of the challenges of visual SLAM from a sUAS including dealing with planar structure, distant scenes and noisy observations. The developed techniques are applied on vision data gathered from a fast-moving fixed-wing radio control aircraft flown over a 1×1km rural area at an altitude of 20-100m.We present both raw Structure from Motion results and a SLAM solution that includes FAB-MAP based loop-closures and graph-optimised pose. Timing information is also presented to demonstrate near online capabilities. We compare the accuracy of the 6-DOF pose estimates to an off-the-shelfGPS aided INS over a 1.7kmtrajectory.We also present output 3D reconstructions of the observed scene structure and texture that demonstrates future applications in autonomous monitoring and surveying.
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Visual sea-floor mapping is a rapidly growing application for Autonomous Underwater Vehicles (AUVs). AUVs are well-suited to the task as they remove humans from a potentially dangerous environment, can reach depths human divers cannot, and are capable of long-term operation in adverse conditions. The output of sea-floor maps generated by AUVs has a number of applications in scientific monitoring: from classifying coral in high biological value sites to surveying sea sponges to evaluate marine environment health.
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The study investigated early childhood teacher decision making at the preschool level in the state of Victoria, Australia. Victorian teachers at the preschool level were in an interesting position in 2004. Unlike most other Australian states Victoria did not have a curriculum framework guiding educational content and pedagogy. Consequently, this study was able to take advantage of this situation and examine teacher decision making at a time when early childhood teachers were relatively autonomous in deciding curriculum content. The opportunity to study teacher decision making in this way has since passed, as Victorian preschool teachers are now regulated by newly introduced state and national curricula frameworks. To identify influences affecting teacher decision making three preschool teachers were interviewed and curricula related policies were analysed. The data were analysed using Fairclough’s critical discourse analysis (CDA) technique. Critical discourse analysis enabled a close analysis of influences on teacher decision making illustrating how discourse is legitimated, marginalised, and silenced in certain curricula practices. Critical theory was the underpinning framework used for the study and enabled taken-for-granted understandings to be uncovered within early childhood policies and teacher interviews. Key findings were that despite there not being a government-mandated curricula framework for Victorian preschool education in 2004, teachers were held accountable for their curricula practice. Yet as professionals, early childhood teachers were denied public acknowledgment of their expertise as they were almost invisible in policy. Subsequently, teachers’ authority as professionals with curricula knowledge was diminished. The study found that developmentally appropriate practice (DAP) was a dominant discourse influencing teacher decision making (TDM). It operated as legitimated discourse in the 2004 Victorian preschool context. Additionally, the study found that teacher directed practice was legitimated, marginalised, and silenced by teachers. The findings have implications for early childhood teacher decision making at the practice, research, and policy levels. Findings show that the dominance of the DAP discourse informing teacher decision making limits other ways of thinking and practising.
Resumo:
The ability to perform autonomous emergency (forced) landings is one of the key technology enablers identified for UAS. This paper presents the flight test results of forced landings involving a UAS, in a controlled environment, and which was conducted to ascertain the performances of previously developed (and published) path planning and guidance algorithms. These novel 3-D nonlinear algorithms have been designed to control the vehicle in both the lateral and longitudinal planes of motion. These algorithms have hitherto been verified in simulation. A modified Boomerang 60 RC aircraft is used as the flight test platform, with associated onboard and ground support equipment sourced Off-the-Shelf or developed in-house at the Australian Research Centre for Aerospace Automation (ARCAA). HITL simulations were conducted prior to the flight tests and displayed good landing performance, however, due to certain identified interfacing errors, the flight results differed from that obtained in simulation. This paper details the lessons learnt and presents a plausible solution for the way forward.
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This paper presents an approach to derive requirements for an avionics architecture that provides onboard sense-and-avoid and autonomous emergency forced landing capabilities to a UAS. The approach is based on two design paradigms that (1) derive requirements analyzing the common functionality between these two functions to then derive requirements for sensors, computing capability, interfaces, etc. (2) consider the risk and safety mitigation associated with these functions to derive certification requirements for the system design. We propose to use the Aircraft Certification Matrix (ACM) approach to tailor the system Development Assurance Levels (DAL) and architecture requirements in accordance with acceptable risk criteria. This architecture is developed under the name “Flight Guardian”. Flight Guardian is an avionics architecture that integrates common sensory elements that are essential components of any UAS that is required to be dependable. The Flight Guardian concept is also applicable to conventionally piloted aircraft, where it will serve to reduce cockpit workload.
Resumo:
Recent efforts in mission planning for underwater vehicles have utilised predictive models to aid in navigation, optimal path planning and drive opportunistic sampling. Although these models provide information at a unprecedented resolutions and have proven to increase accuracy and effectiveness in multiple campaigns, most are deterministic in nature. Thus, predictions cannot be incorporated into probabilistic planning frameworks, nor do they provide any metric on the variance or confidence of the output variables. In this paper, we provide an initial investigation into determining the confidence of ocean model predictions based on the results of multiple field deployments of two autonomous underwater vehicles. For multiple missions conducted over a two-month period in 2011, we compare actual vehicle executions to simulations of the same missions through the Regional Ocean Modeling System in an ocean region off the coast of southern California. This comparison provides a qualitative analysis of the current velocity predictions for areas within the selected deployment region. Ultimately, we present a spatial heat-map of the correlation between the ocean model predictions and the actual mission executions. Knowing where the model provides unreliable predictions can be incorporated into planners to increase the utility and application of the deterministic estimations.
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Circoviruses lack an autonomous DNA polymerase and are dependent on the replication machinery of the host cell for de novo DNA synthesis. Accordingly, the viral DNA needs to cross both the plasma membrane and the nuclear envelope before replication can occur. Here we report on the subcellular distribution of the beak and feather disease virus (BFDV) capsid protein (CP) and replication-associated protein (Rep) expressed via recombinant baculoviruses in an insect cell system and test the hypothesis that the CP is responsible for transporting the viral genome, as well as Rep, across the nuclear envelope. The intracellular localization of the BFDV CP was found to be directed by three partially overlapping bipartite nuclear localization signals (NLSs) situated between residues 16 and 56 at the N terminus of the protein. Moreover, a DNA binding region was also mapped to the N terminus of the protein and falls within the region containing the three putative NLSs. The ability of CP to bind DNA, coupled with the karyophilic nature of this protein, strongly suggests that it may be responsible for nuclear targeting of the viral genome. Interestingly, whereas Rep expressed on its own in insect cells is restricted to the cytoplasm, coexpression with CP alters the subcellular localization of Rep to the nucleus, strongly suggesting that an interaction with CP facilitates movement of Rep into the nucleus. Copyright © 2006, American Society for Microbiology. All Rights Reserved.
Resumo:
In most visual mapping applications suited to Autonomous Underwater Vehicles (AUVs), stereo visual odometry (VO) is rarely utilised as a pose estimator as imagery is typically of very low framerate due to energy conservation and data storage requirements. This adversely affects the robustness of a vision-based pose estimator and its ability to generate a smooth trajectory. This paper presents a novel VO pipeline for low-overlap imagery from an AUV that utilises constrained motion and integrates magnetometer data in a bi-objective bundle adjustment stage to achieve low-drift pose estimates over large trajectories. We analyse the performance of a standard stereo VO algorithm and compare the results to the modified vo algorithm. Results are demonstrated in a virtual environment in addition to low-overlap imagery gathered from an AUV. The modified VO algorithm shows significantly improved pose accuracy and performance over trajectories of more than 300m. In addition, dense 3D meshes generated from the visual odometry pipeline are presented as a qualitative output of the solution.
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The ‘Fashion Tales’ Conference identifies three fashion discourses: that of making, that of media, and that of scholarship. We propose a fourth, which provides a foundational base for the others: the discourse of fashion pedagogy. We begin with the argument that to thrive in any of these discourses, all fashion graduates require the ability to navigate the complexities of the 21st century fashion industry. Fashion graduates emerge into a professional world which demands a range of high level capabilities above and beyond those traditionally acknowledged by the discipline. Professional education in fashion must transform itself to accommodate these imperatives. In this paper, we document a tale of fashion learning, teaching and scholarship – the tale of a highly successful future-orientated boutique university-based undergraduate fashion course in Queensland, Australia. The Discipline consistently maintains the highest student satisfaction and lowest attrition of any course in the university, achieves extremely competitive student satisfaction scores when compared with other courses nationally and internationally, and reports outstanding graduate employment outcomes. The core of the article addresses how the course effectively balances five key pedagogical tensions identified from the findings of in-depth focus groups with graduating students, and interviews with teaching staff. The pedagogical tensions are: high concept/ authenticity; high disciplinarity/ interdisciplinarity; high rigour/ play; high autonomy/ scaffolding; and high individuality/ community, where community can be further divided into high challenge and high support. We discuss each of these tensions and how they are characterised within the course, using rich descriptions given by the students. We also draw upon the wider andragogical and learning futures literatures to link the tensions with what is already known about excellence in 21st century higher and further education curriculum and pedagogic practice. We ask: as the fashion industry becomes truly globalised, virtualised, and diversified, and as initial professional training for the industry becomes increasingly massified and performatised, what are the best teaching approaches to produce autonomous, professionally capable, enterprising and responsible graduates into the future? Can the pedagogical balances described in this case study be maintained in the light of these powerful external forces, and if so, how?
Resumo:
This paper describes a qualitative study that investigated young adolescents’ self-constructions within the context of online (email) communication. Drawing from dialogical perspectives of self as multiply-situated and complex phenomena, the study focused on the everyday narratives of individual young adolescents interpreted as different “I” voices. With the assumption that computer mediation offers cultural relevance and empowerment to young adolescents, techniques of personal journal writing were used in combination with email as an alternative to face-to-face methods. Twelve participants aged 10 to 14 years were recruited online and by word-of-mouth with an invitation to write freely about their lives over a six month period in a participant-led email journal project. The role of the researcher was to develop a supportive voice of listener/responder that was intended to facilitate the emergence of participants’ own ‘self’ voices within an interactive space for relatively autonomous self-expression. Data as email texts were analysed using a close listening method that synchronised with the theory by revealing multi-layered patterns and shifts of voices in order to give a nuanced understanding of participants’ self and other evaluations. The paper shows that narrative methods used online and in concert with dialogical concepts have potential to heighten self-reflection and strengthen agency as a means to access rich and nuanced data from young adolescent individuals. The study’s findings contribute to a growing interest in the use of dialogical concepts to explore the ways people engage in active meaning-making while embedded in their specific social and cultural environments.
Resumo:
The challenge of persistent appearance-based navigation and mapping is to develop an autonomous robotic vision system that can simultaneously localize, map and navigate over the lifetime of the robot. However, the computation time and memory requirements of current appearance-based methods typically scale not only with the size of the environment but also with the operation time of the platform; also, repeated revisits to locations will develop multiple competing representations which reduce recall performance. In this paper we present a solution to the persistent localization, mapping and global path planning problem in the context of a delivery robot in an office environment over a one-week period. Using a graphical appearance-based SLAM algorithm, CAT-Graph, we demonstrate constant time and memory loop closure detection with minimal degradation during repeated revisits to locations, along with topological path planning that improves over time without using a global metric representation. We compare the localization performance of CAT-Graph to openFABMAP, an appearance-only SLAM algorithm, and the path planning performance to occupancy-grid based metric SLAM. We discuss the limitations of the algorithm with regard to environment change over time and illustrate how the topological graph representation can be coupled with local movement behaviors for persistent autonomous robot navigation.
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RatSLAM is a navigation system based on the neural processes underlying navigation in the rodent brain, capable of operating with low resolution monocular image data. Seminal experiments using RatSLAM include mapping an entire suburb with a web camera and a long term robot delivery trial. This paper describes OpenRatSLAM, an open-source version of RatSLAM with bindings to the Robot Operating System framework to leverage advantages such as robot and sensor abstraction, networking, data playback, and visualization. OpenRatSLAM comprises connected ROS nodes to represent RatSLAM’s pose cells, experience map, and local view cells, as well as a fourth node that provides visual odometry estimates. The nodes are described with reference to the RatSLAM model and salient details of the ROS implementation such as topics, messages, parameters, class diagrams, sequence diagrams, and parameter tuning strategies. The performance of the system is demonstrated on three publicly available open-source datasets.
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This paper details the progress to date, toward developing a small autonomous helicopter. We describe system architecture, avionics, visual state estimation, custom IMU design, aircraft modelling, as well as various linear and neuro/fuzzy control algorithms. Experimental results are presented for state estimation using fused stereo vision and IMU data, heading control, and attitude control. FAM attitude and velocity controllers have been shown to be effective in simulation.
Resumo:
A firm, as a dynamic, evolving, and quasi-autonomous system of knowledge production and application, develops knowledge management capability (KMC) through strategic learning in order to sustain competitive advantages in a dynamic environment. Knowledge governance mechanisms and knowledge processes connect and interact with each other forming learning mechanisms, which carry out double loop learning that drives genesis and evolution of KMC to modify operating routines that effect desired performance. This paper reports a study that was carried out within a context of construction contractors, a type of project-based firms, operating within the dynamic Hong Kong construction market. A multiple-case design was used to incorporate evidence from the literature and interviews, with the help of system dynamics modeling, to visualize the evolution of KMC. The study demonstrates the feasibility to visualize how a firm's KMC matches its operating environment over time. The findings imply that knowledge management (KM) applications can be better planned and controlled through evaluation of KM performance over time from a capability perspective.