514 resultados para uses


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We conduct the detailed numerical investigation of a nanomanipulation and nanofabrication techniquethermal tweezers with dynamic evolution of surface temperature, caused by absorption of interfering laser pulses in a thin metalfilm or any other absorbing surface. This technique uses random Brownian forces in the presence of strong temperature modulation (surfacethermophoresis) for effective manipulation of particles/adatoms with nanoscale resolution. Substantial redistribution of particles on the surface is shown to occur with the typical size of the obtained pattern elements of 100 nm, which is significantly smaller than the wavelength of the incident pulses used (532 nm). It is also demonstrated that thermal tweezers based on surfacethermophoresis of particles/adatoms are much more effective in achieving permanent high maximum-to-minimum concentration ratios than bulk thermophoresis, which is explained by the interaction of diffusing particles with the periodic lattice potential on the surface. Typically required pulse regimes including pulse lengths and energies are also determined. The approach is applicable for reproducing any holographically achievable surfacepatterns, and can thus be used for engineering properties of surfaces including nanopatterning and design of surface metamaterials.

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Numerous expert elicitation methods have been suggested for generalised linear models (GLMs). This paper compares three relatively new approaches to eliciting expert knowledge in a form suitable for Bayesian logistic regression. These methods were trialled on two experts in order to model the habitat suitability of the threatened Australian brush-tailed rock-wallaby (Petrogale penicillata). The first elicitation approach is a geographically assisted indirect predictive method with a geographic information system (GIS) interface. The second approach is a predictive indirect method which uses an interactive graphical tool. The third method uses a questionnaire to elicit expert knowledge directly about the impact of a habitat variable on the response. Two variables (slope and aspect) are used to examine prior and posterior distributions of the three methods. The results indicate that there are some similarities and dissimilarities between the expert informed priors of the two experts formulated from the different approaches. The choice of elicitation method depends on the statistical knowledge of the expert, their mapping skills, time constraints, accessibility to experts and funding available. This trial reveals that expert knowledge can be important when modelling rare event data, such as threatened species, because experts can provide additional information that may not be represented in the dataset. However care must be taken with the way in which this information is elicited and formulated.

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Computer vision is much more than a technique to sense and recover environmental information from an UAV. It should play a main role regarding UAVs functionality because of the big amount of information that can be extracted, its possible uses and applications, and its natural connection to human driven tasks, taking into account that vision is our main interface to world understanding. Our current researchs focus lays on the development of techniques that allow UAVs to maneuver in spaces using visual information as their main input source. This task involves the creation of techniques that allow an UAV to maneuver towards features of interest whenever a GPS signal is not reliable or sufficient, e.g. when signal dropouts occur (which usually happens in urban areas, when flying through terrestrial urban canyons or when operating on remote planetary bodies), or when tracking or inspecting visual targetsincluding moving oneswithout knowing their exact UMT coordinates. This paper also investigates visual serving control techniques that use velocity and position of suitable image features to compute the references for flight control. This paper aims to give a global view of the main aspects related to the research field of computer vision for UAVs, clustered in four main active research lines: visual serving and control, stereo-based visual navigation, image processing algorithms for detection and tracking, and visual SLAM. Finally, the results of applying these techniques in several applications are presented and discussed: this study will encompass power line inspection, mobile target tracking, stereo distance estimation, mapping and positioning.

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This chapter reports on a critical literacy approach to developing intercultural competence in an EFL/ESL classroom: an approach which uses a form of 'connective analysis' between linguacultures leading to productive exploration of the interstices between cultures.

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This paper describes an experiment undertaken to investigate intuitive interaction, particularly in older adults. Previous work has shown that intuitive interaction relies on past experience, and has also suggested that older people demonstrate less intuitive uses and slower times when completing set tasks with various devices. Similarly, this experiment showed that past experience with relevant products allowed people to use the interfaces of two different microwaves more quickly, although there were no significant differences between the different microwaves. It also revealed that certain aspects of cognitive decline related to aging, such as central executive function, have more impact on time, correct uses and intuitive uses than chronological age. Implications of these results and further work in this area are discussed.

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The first chapter called 'Investigating texts' asks students to investigate the concept of text and what it might mean to 'behave like a reader'. After reading and comparing two short stories, the question, 'what is a story?' is posed. Students are then asked to distinguish a fiction text from a number of non-fiction texts and to identify the sources of the latter. It is suggested that although it is quite easy to perform these tasks, it is not so easy to describe texts in terms only of their features or ingredients; that it is necessary to talk about how texts are read, and what is more, how they are read on particular occasions. 'Making texts', the second chapter, asks students via a series of activities to consider what they expect of texts, and to investigate the conventions of fiction and non-fiction. They are given the opportunity to manipulate the 'ingredients' of texts, to read in terms of commonalities and to speculate about the rules by which both the composition and consumption of texts are organised. The ways in which particular kinds of reading and writing activities assume the text as a certain kind of object - as a model, for example, or as an object of criticism or as an occasion for self-questioning - is made explicit, and students are encouraged to investigate a range of uses of texts and the implications of these for reading and writing. Chapter three, 'Changing texts' asks students to consider, through a number of fascinating examples, how both fiction and non-fiction texts have changed over time, and how the ways in which readers read texts can change too. The 'retelling' of texts in terms of changing norms is considered via an 'updated' version of 'Scheherazade'; a student's feminist adaptation of her own text (initially written using a romance as a model), and an encyclopedia entry. 'Reading practices', the fourth chapter, poses further questions about different ways of reading. Through reading a number of didactic texts alongside three stories from a genre that is not usually read for morally improving lessons, students are asked to consider how different their reading practices can be.

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Residents, businesses, local, state and national government stakeholders all want to have their say when airports expand or develop. While stakeholder engagement is increasingly a strategy employed for managing the tensions attracted to airport development, different stakeholders have different expectations and demands of airports. This requires different approaches to stakeholder engagement. Identifying the public interests that are at stake in developing airports provides an initial step towards building a platform for selecting and applying stakeholder engagement strategies in airport and more general infrastructure contexts. This paper uses the existing literature of public interests and values to build a general typology of public values for the stakeholders of airport development. A range of semi-privatised and state owned airport case studies from Europe have been used to demonstrate the universal nature of the identified values. The result is a framework that identifies both the substantive and procedural values, separated into local, state/regional and national levels of interest. The typology provides a generalised view of public interests in airport development; however, the public interests identified may be limited to more western oriented societies due to the skew of airport cases reviewed. Contributions are made to the literature with a typology of public values derived from existing knowledge and explored using empirical case examples. The provided typology enables research of airport development decision-making to delineate public interests both within and between stakeholder groups, and helps to explain the different perspectives that stakeholders have towards airport development. Future research may focus on refining the typology for different types of airport governance structures, such as differences between public values in state and market-led airport development; include more airport cases from eastern societies to draw parallels or differences between western and eastern societies; or utilise the typology as a framework for analysing changes in public interests of airports over time.

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Object tracking systems require accurate segmentation of the objects from the background for effective tracking. Motion segmentation or optical flow can be used to segment incoming images. Whilst optical flow allows multiple moving targets to be separated based on their individual velocities, optical flow techniques are prone to errors caused by changing lighting and occlusions, both common in a surveillance environment. Motion segmentation techniques are more robust to fluctuating lighting and occlusions, but don't provide information on the direction of the motion. In this paper we propose a combined motion segmentation/optical flow algorithm for use in object tracking. The proposed algorithm uses the motion segmentation results to inform the optical flow calculations and ensure that optical flow is only calculated in regions of motion, and improve the performance of the optical flow around the edge of moving objects. Optical flow is calculated at pixel resolution and tracking of flow vectors is employed to improve performance and detect discontinuities, which can indicate the location of overlaps between objects. The algorithm is evaluated by attempting to extract a moving target within the flow images, given expected horizontal and vertical movement (i.e. the algorithms intended use for object tracking). Results show that the proposed algorithm outperforms other widely used optical flow techniques for this surveillance application.

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In an automotive environment, the performance of a speech recognition system is affected by environmental noise if the speech signal is acquired directly from a microphone. Speech enhancement techniques are therefore necessary to improve the speech recognition performance. In this paper, a field-programmable gate array (FPGA) implementation of dual-microphone delay-and-sum beamforming (DASB) for speech enhancement is presented. As the first step towards a cost-effective solution, the implementation described in this paper uses a relatively high-end FPGA device to facilitate the verification of various design strategies and parameters. Experimental results show that the proposed design can produce output waveforms close to those generated by a theoretical (floating-point) model with modest usage of FPGA resources. Speech recognition experiments are also conducted on enhanced in-car speech waveforms produced by the FPGA in order to compare recognition performance with the floating-point representation running on a PC.

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Modern computer graphics systems are able to construct renderings of such high quality that viewers are deceived into regarding the images as coming from a photographic source. Large amounts of computing resources are expended in this rendering process, using complex mathematical models of lighting and shading. However, psychophysical experiments have revealed that viewers only regard certain informative regions within a presented image. Furthermore, it has been shown that these visually important regions contain low-level visual feature differences that attract the attention of the viewer. This thesis will present a new approach to image synthesis that exploits these experimental findings by modulating the spatial quality of image regions by their visual importance. Efficiency gains are therefore reaped, without sacrificing much of the perceived quality of the image. Two tasks must be undertaken to achieve this goal. Firstly, the design of an appropriate region-based model of visual importance, and secondly, the modification of progressive rendering techniques to effect an importance-based rendering approach. A rule-based fuzzy logic model is presented that computes, using spatial feature differences, the relative visual importance of regions in an image. This model improves upon previous work by incorporating threshold effects induced by global feature difference distributions and by using texture concentration measures. A modified approach to progressive ray-tracing is also presented. This new approach uses the visual importance model to guide the progressive refinement of an image. In addition, this concept of visual importance has been incorporated into supersampling, texture mapping and computer animation techniques. Experimental results are presented, illustrating the efficiency gains reaped from using this method of progressive rendering. This visual importance-based rendering approach is expected to have applications in the entertainment industry, where image fidelity may be sacrificed for efficiency purposes, as long as the overall visual impression of the scene is maintained. Different aspects of the approach should find many other applications in image compression, image retrieval, progressive data transmission and active robotic vision.

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Social and psychological theories have provided a plethora of evidence showing that the physical difficulty to express appropriate social interactions between drivers expresses itself in aggression, selfish driving and anti-social behaviour. Therefore there is a need to improve interactions between drivers and allow clearer collective decision making between them. Personal characteristics and the driving situations play strong roles in drivers aggression. Our approach is centered around the driving situation as opposed to focusing on personality characteristics. It examines aggression and manipulates contextual variables such as drivers eye contact exchanges. This paper presents a new unobtrusive in-vehicle system that aims at communicating drivers intentions, elicit social responses and increasing mutual awareness. It uses eye gaze as a social cue to affect collective decision making with the view to contribute to safe driving. The authors used a driving simulator to design a case control experiment in which eye gaze movements are conveyed with an avatar. Participants were asked to drive through different types of intersections. An avatar representing the head of the other driver was displayed and driver behaviour was analysed. Significant eye gaze pattern difference where observed when an avatar was displayed. Drivers cautiously refer to the avatar when information is required on the intention of others (e.g. when they do not have the right of way). The majority of participants reported the perception of being looked at. The number of glances and time spent gazing at the avatar did not indicate an unsafe distraction by standards of in-vehicle device ergonomic design. Avatars were visually consulted primarily in less demanding driving situations, which underlines their non-distractive nature.

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The word queer is a slippery one; its etymology is uncertain, and academic and popular usage attributes conflicting meanings to the word. By the mid-nineteenth century, queer was used as a pejorative term for a (male) homosexual. This negative connotation continues when it becomes a term for homophobic abuse. In recent years, queer has taken on additional uses: as an all encompassing term for culturally marginalised sexualities gay, lesbian, trans, bi, and intersex (GLBTI) and as a theoretical strategy which deconstructs binary oppositions that govern identity formation. Tracing its history, the Oxford English Dictionary notes that the earliest references to queer may have appeared in the sixteenth century. These early examples of queer carried negative connotations such as vulgar, bad, worthless, strange, or odd and such associations continued until the mid-twentieth century. The early nineteenth century, and perhaps earlier, employed queer as a verb, meaning to to put out of order, to spoil, to interfere with. The adjectival form also began to emerge during this time to refer to a persons condition as being not normal, out of sorts or to cause a person to feel queer meaning to disconcert, perturb, unsettle. According to Eve Sedgwick (1993), the word queer itself means across it comes from the Indo-European root twerkw, which also yields the German quer (traverse), Latin torquere (to twist), English athwart . . . it is relational and strange. Despite the gaps in the lineage and changes in usage, meaning and grammatical form, queer as a political and theoretical strategy has benefited from its diverse origins. It refuses to settle comfortably into a single classification, preferring instead to traverse several categories that would otherwise attempt to stabilise notions of chromosomal sex, gender and sexuality.

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This paper proposes the use of the Bayes Factor to replace the Bayesian Information Criterion (BIC) as a criterion for speaker clustering within a speaker diarization system. The BIC is one of the most popular decision criteria used in speaker diarization systems today. However, it will be shown in this paper that the BIC is only an approximation to the Bayes factor of marginal likelihoods of the data given each hypothesis. This paper uses the Bayes factor directly as a decision criterion for speaker clustering, thus removing the error introduced by the BIC approximation. Results obtained on the 2002 Rich Transcription (RT-02) Evaluation dataset show an improved clustering performance, leading to a 14.7% relative improvement in the overall Diarization Error Rate (DER) compared to the baseline system.

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The loadfrequency control (LFC) problem has been one of the major subjects in a power system. In practice, LFC systems use proportionalintegral (PI) controllers. However since these controllers are designed using a linear model, the non-linearities of the system are not accounted for and they are incapable of gaining good dynamical performance for a wide range of operating conditions in a multi-area power system. A strategy for solving this problem because of the distributed nature of a multi-area power system is presented by using a multi-agent reinforcement learning (MARL) approach. It consists of two agents in each power area; the estimator agent provides the area control error (ACE) signal based on the frequency bias estimation and the controller agent uses reinforcement learning to control the power system in which genetic algorithm optimisation is used to tune its parameters. This method does not depend on any knowledge of the system and it admits considerable flexibility in defining the control objective. Also, by finding the ACE signal based on the frequency bias estimation the LFC performance is improved and by using the MARL parallel, computation is realised, leading to a high degree of scalability. Here, to illustrate the accuracy of the proposed approach, a three-area power system example is given with two scenarios.

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Experimental / pilot online journalistic publication. EUAustralia Online (www.euaustralia.com) is a pilot niche publication identifying and demonstrating dynamics of online journalism. The editor, an experienced and senior journalist and academic, specialist in European studies, commenced publication on 28.8.06 during one years industry immersion -- with media accreditation to the European Commission, Brussels. Reporting now is from Australia and from Europe on field trip exercises. Student editors participate making it partly a training operation. EUAustralia demonstrates adaptation of conventional, universal, Western liberal journalistic practices. Its first premise is to fill a knowledge gap in Australia about the European Union -- institutions, functions and directions. The second premise is to test the communications capacity of the online format, where the publication sets a strong standard of journalistic credibility hence its transparency with sourcing or signposting of commentary or opinion. EUAustralia uses modified, enhanced weblog software allowing for future allocation of closed pages to subscribers. An early exemplar of its kind, with modest upload rate (2010-13 average, 16 postings monthly), esteemed, it commands over 180000 site visits p.a. (half as unique visitors; AWB Statistics); strongly rated by search engines, see page one Googlr placements for EU Australia. Comment by the ISP (SeventhVision, Broadbeach, Queensland): The site has good search engine recognition because seen as credible; can be used to generate revenue. This journalistic exercise has been analysed in theoretical context twice, in published refereed conference proceedings (Communication and Media Policy Forum, Sydney; 2007, 2009).