995 resultados para mobile sensors


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In Australia there is growing interest in a national curriculum to replace the variety of matriculation credentials managed by State Education departments, ostensibly to address increasing population mobility. Meanwhile, the International Baccalaureate (IB) is attracting increasing interest and enrolments in State and private schools in Australia, and has been considered as one possible model for a proposed Australian Certificate of Education. This paper will review the construction of this curriculum in Australian public discourse as an alternative frame for producing citizens, and ask why this design appeals now, to whom, and how the phenomenon of its growing appeal might inform national curricular debates. The IB’s emergence is understood with reference to the larger context of neo-liberal marketization policies, neo-conservative claims on the curriculum and middle class strategy. The paper draws on public domain documents from the IB Organisation and newspaper reportage to demonstrate how the IB is constructed for public consumption in Australia.

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This paper reports on a study of students choosing the International Baccalaureate Diploma (IBD) over state-based curricula in Australian schools. The IBD was initially designed as a matriculation certificate to facilitate international mobility. While first envisaged as a lifestyle agenda for cultural elites, such mobility is now widespread with more people living ‘beyond the nation’ through choice or circumstance. Beck (2007) and others highlight how the capacity to cross national borders offers a competitive edge with which to strategically pursue economic and cultural capital. Beck’s ‘border artistes’ are those who use national borders to their individual advantage through reflexive strategy. The study explored the rationales and strategy behind the choice of the IBD curriculum expressed by students in a focus group interview and an online survey. This paper reports on their imagined transnational routes and mobile orientations, and how a localised curriculum limits their imagined mobile futures.

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Improving the performance of a incident detection system was essential to minimize the effect of incidents. A new method of incident detection was brought forward in this paper based on an in-car terminal which consisted of GPS module, GSM module and control module as well as some optional parts such as airbag sensors, mobile phone positioning system (MPPS) module, etc. When a driver or vehicle discovered the freeway incident and initiated an alarm report the incident location information located by GPS, MPPS or both would be automatically send to a transport management center (TMC), then the TMC would confirm the accident with a closed-circuit television (CCTV) or other approaches. In this method, detection rate (DR), time to detect (TTD) and false alarm rate (FAR) were more important performance targets. Finally, some feasible means such as management mode, education mode and suitable accident confirming approaches had been put forward to improve these targets.

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The emergence of sophisticated multimedia phones in combination with improvements to the mobile Internet provides the possibility to read texts and stories on mobile handsets. However, the question is, how to adapt stories in order to take advantage of the user’s mobility and create an engaging and appealing experience. To address these new conditions, a Mobile Narrative was created and access to individual chapters of the story was restricted. Authors can specify constraints, such as a location or time, which need to be met by the reader if they want to read the story. This concept allows creative writers of the story to exploit the fact that the reader’s context is known, by intensifying the user experience and integrating this knowledge into the writing process. Interviews with authors and creative writers and two user studies explored the effects of this way of writing on both parties. The paper presents our preliminary research findings discussing this new experience that was found to be exciting and interesting by both sides.

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To navigate successfully in a previously unexplored environment, a mobile robot must be able to estimate the spatial relationships of the objects of interest accurately. A Simultaneous Localization and Mapping (SLAM) sys- tem employs its sensors to build incrementally a map of its surroundings and to localize itself in the map simultaneously. The aim of this research project is to develop a SLAM system suitable for self propelled household lawnmowers. The proposed bearing-only SLAM system requires only an omnidirec- tional camera and some inexpensive landmarks. The main advantage of an omnidirectional camera is the panoramic view of all the landmarks in the scene. Placing landmarks in a lawn field to define the working domain is much easier and more flexible than installing the perimeter wire required by existing autonomous lawnmowers. The common approach of existing bearing-only SLAM methods relies on a motion model for predicting the robot’s pose and a sensor model for updating the pose. In the motion model, the error on the estimates of object positions is cumulated due mainly to the wheel slippage. Quantifying accu- rately the uncertainty of object positions is a fundamental requirement. In bearing-only SLAM, the Probability Density Function (PDF) of landmark position should be uniform along the observed bearing. Existing methods that approximate the PDF with a Gaussian estimation do not satisfy this uniformity requirement. This thesis introduces both geometric and proba- bilistic methods to address the above problems. The main novel contribu- tions of this thesis are: 1. A bearing-only SLAM method not requiring odometry. The proposed method relies solely on the sensor model (landmark bearings only) without relying on the motion model (odometry). The uncertainty of the estimated landmark positions depends on the vision error only, instead of the combination of both odometry and vision errors. 2. The transformation of the spatial uncertainty of objects. This thesis introduces a novel method for translating the spatial un- certainty of objects estimated from a moving frame attached to the robot into the global frame attached to the static landmarks in the environment. 3. The characterization of an improved PDF for representing landmark position in bearing-only SLAM. The proposed PDF is expressed in polar coordinates, and the marginal probability on range is constrained to be uniform. Compared to the PDF estimated from a mixture of Gaussians, the PDF developed here has far fewer parameters and can be easily adopted in a probabilistic framework, such as a particle filtering system. The main advantages of our proposed bearing-only SLAM system are its lower production cost and flexibility of use. The proposed system can be adopted in other domestic robots as well, such as vacuum cleaners or robotic toys when terrain is essentially 2D.

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Growing participation is a key challenge for the viability of sustainability initiatives, many of which require enactment at a local community level in order to be effective. This paper undertakes a review of technology assisted carpooling in order to understand the challenge of designing participation and consider how mobile social software and interface design can be brought to bear. It was found that while persuasive technology and social networking approaches have roles to play, critical factors in the design of carpooling are convenience, ease of use and fit with contingent circumstances, all of which require a use-centred approach to designing a technological system and building participation. Moreover, the reach of technology platform-based global approaches may be limited if they do not cater to local needs. An approach that focuses on iteratively designing technology to support and grow mobile social ridesharing networks in particular locales is proposed. The paper contributes an understanding of HCI approaches in the context of other designing participation approaches.

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This study explored the psychological influences of hands-free and hand-held mobile phone use while driving. Participants were 796 Australian drivers aged 17 to 76 years who owned mobile phones. A cross-sectional survey assessed frequency of calling and text messaging while driving (overall, hands-free, hand-held) as well as drivers’ behavioural, normative, and control beliefs relating to mobile phone use while driving. Irrespective of handset type, 43% of drivers reported answering calls while driving on a daily basis, followed by making calls (36%), reading text messages (27%), and sending text messages (18%). In total, 63.9% of drivers did not own hands-free kits and, of the drivers that owned hand-free kits, 32% did not use it most or all of the time. Significant differences were found in the behavioural, normative, and control beliefs of frequent and infrequent users of both types of handset while driving. As expected, frequent users reported more advantages of, more approval from others for, and fewer barriers that would prevent them from, using either a hands-free or a hand-held mobile phone while driving than infrequent users. Campaigns to reduce mobile phone use while driving should attempt to minimise the perceived benefits of the behaviour and highlight the risks of this unsafe driving practice.

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This thesis investigates the problem of robot navigation using only landmark bearings. The proposed system allows a robot to move to a ground target location specified by the sensor values observed at this ground target posi- tion. The control actions are computed based on the difference between the current landmark bearings and the target landmark bearings. No Cartesian coordinates with respect to the ground are computed by the control system. The robot navigates using solely information from the bearing sensor space. Most existing robot navigation systems require a ground frame (2D Cartesian coordinate system) in order to navigate from a ground point A to a ground point B. The commonly used sensors such as laser range scanner, sonar, infrared, and vision do not directly provide the 2D ground coordi- nates of the robot. The existing systems use the sensor measurements to localise the robot with respect to a map, a set of 2D coordinates of the objects of interest. It is more natural to navigate between the points in the sensor space corresponding to A and B without requiring the Cartesian map and the localisation process. Research on animals has revealed how insects are able to exploit very limited computational and memory resources to successfully navigate to a desired destination without computing Cartesian positions. For example, a honeybee balances the left and right optical flows to navigate in a nar- row corridor. Unlike many other ants, Cataglyphis bicolor does not secrete pheromone trails in order to find its way home but instead uses the sun as a compass to keep track of its home direction vector. The home vector can be inaccurate, so the ant also uses landmark recognition. More precisely, it takes snapshots and compass headings of some landmarks. To return home, the ant tries to line up the landmarks exactly as they were before it started wandering. This thesis introduces a navigation method based on reflex actions in sensor space. The sensor vector is made of the bearings of some landmarks, and the reflex action is a gradient descent with respect to the distance in sensor space between the current sensor vector and the target sensor vec- tor. Our theoretical analysis shows that except for some fully characterized pathological cases, any point is reachable from any other point by reflex action in the bearing sensor space provided the environment contains three landmarks and is free of obstacles. The trajectories of a robot using reflex navigation, like other image- based visual control strategies, do not correspond necessarily to the shortest paths on the ground, because the sensor error is minimized, not the moving distance on the ground. However, we show that the use of a sequence of waypoints in sensor space can address this problem. In order to identify relevant waypoints, we train a Self Organising Map (SOM) from a set of observations uniformly distributed with respect to the ground. This SOM provides a sense of location to the robot, and allows a form of path planning in sensor space. The navigation proposed system is analysed theoretically, and evaluated both in simulation and with experiments on a real robot.

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This thesis by publication contributes to our knowledge of psychological factors underlying a modern day phenomenon, young people’s mobile phone behaviour. Specifically, the thesis reports a PhD program of research which adopted a social psychological approach to explore mobile phone behaviour among young Australians aged between 15 and 24 years. A particular focus of the research program was to explore both the cognitive and behavioural aspects of young people’s mobile phone behaviour which for the purposes of this thesis is defined as mobile phone involvement. The research program comprised three separate stages which were developmental in nature, in that, the findings of each stage of the research program informed the next. The overarching goal of the program of research was to improve our understanding of the psychosocial factors influencing young people’s mobile phone behaviour. To achieve this overall goal, there were a number of aims to the research program which reflect the developmental nature of this thesis. Given the limited research into the mobile phone behaviour in Australia, the first two aims of the research program were to explore patterns of mobile phone behaviour among Australian youth and explore the social psychological factors relating to their mobile phone behaviour. Following this exploration, the research program sought to develop a measure which captures the cognitive and behavioural aspects of mobile phone behaviour. Finally, the research program aimed to examine and differentiate the psychosocial predictors of young people’s frequency of mobile phone use and their level of involvement with their mobile phone. Both qualitative and quantitative methodologies were used throughout the program of research. Five papers prepared during the three stages of the research program form the bulk of this thesis. The first stage of the research program was a qualitative investigation of young people’s mobile phone behaviour. Thirty-two young Australians participated in a series of focus groups in which they discussed their mobile phone behaviour. Thematic data analysis explored patterns of mobile phone behaviour among young people, developed an understanding of psychological factors influencing their use of mobile phones, and identified that symptoms of addiction were emerging in young people’s mobile phone behaviour. Two papers (Papers 1 and 2) emanated from this first stage of the research program. Paper 1 explored patterns of mobile phone behaviour and revealed that mobile phones were perceived as being highly beneficial to young people’s lives, with the ability to remain in constant contact with others being particularly valued. The paper also identified that symptoms of behavioural addiction including withdrawal, cognitive and behavioural salience, and loss of control, emerged in participants’ descriptions of their mobile phone behaviour. Paper 2 explored how young people’s need to belong and their social identity (two constructs previously unexplored in the context of mobile phone behaviour) related to their mobile phone behaviour. It was revealed that young people use their mobile phones to facilitate social attachments. Additionally, friends and peers influenced young people’s mobile phone behaviour; for example, their choice of mobile phone carrier and their most frequent type of mobile phone use. These papers laid the foundation for the further investigation of addictive patterns of behaviour and the role of social psychological factors on young people’s mobile behaviour throughout the research program. Stage 2 of the research program focussed on developing a new parsimonious measure of mobile phone behaviour, the Mobile Phone Involvement Questionnaire (MPIQ), which captured the cognitive and behavioural aspects of mobile phone use. Additionally, the stage included a preliminary exploration of factors influencing young people’s mobile phone behaviour. Participants (N = 946) completed a questionnaire which included a pool of items assessing symptoms of behavioural addiction, the uses and gratifications relating to mobile phone use, and self-identity and validation from others in the context of mobile phone behaviour. Two papers (Papers 3 & 4) emanated from the second stage of the research program. Paper 3 provided an important link between the qualitative and quantitative components of the research program. Qualitative data from Stage 1 indicated the reasons young people use their mobile phones and identified addictive characteristics present in young people’s mobile phone behaviour. Results of the quantitative study conducted in Stage 2 of the research program revealed the uses and gratifications relating to young people’s mobile phone behaviour and the effect of these gratifications on young people’s frequency of mobile phone use and three indicators of addiction, withdrawal, salience, and loss of control. Three major uses and gratifications: self (such as feeling good or as a fashion item), social (such as contacting friends), and security (such as use in an emergency) were found to underlie much of young people’s mobile phone behaviour. Self and social gratifications predicted young people’s frequency of mobile phone use and the three indicators of addiction but security gratifications did not. These results provided an important foundation for the inclusion of more specific psychosocial predictors in the later stages of the research program. Paper 4 reported the development of the mobile phone involvement questionnaire and a preliminary exploration of the effect of self-identity and validation from others on young people’s mobile phone behaviour. The MPIQ assessed a unitary construct and was a reliable measure amongst this cohort. Results found that self-identity influenced the frequency of young people’s use whereas self-identity and validation from others influenced their level of mobile phone involvement. These findings provided an important indication that, in addition to self factors, other people have a strong influence on young people’s involvement with their mobile phone and that mobile phone involvement is conceptually different to frequency of mobile phone use. Stage 3 of the research program empirically examined the psychosocial predictors of young people’s mobile behaviour and one paper, Paper 5, emanated from this stage. Young people (N = 292) from throughout Australia completed an online survey assessing the role of self-identity, ingroup norm, the need to belong, and self-esteem on their frequency of mobile phone use and their mobile phone involvement. Self-identity was the only psychosocial predictor of young people’s frequency of mobile phone use. In contrast, self-identity, ingroup norm, and need to belong all influenced young people’s level of involvement with their mobile phone. Additionally, the effect of self-esteem on young people’s mobile phone involvement was mediated by their need to belong. These results indicate that young people who perceive their mobile phone to be an integral part of their self-identity, who perceive that mobile phone is common amongst friends and peers, and who have a strong need for attachment to others, in some cases driven by a desire to enhance their self-esteem, are most likely to become highly involved with their mobile phones. Overall, this PhD program of research has provided an important contribution to our understanding of young Australians’ mobile phone behaviour. Results of the program have broadened our knowledge of factors influencing mobile phone behaviour beyond the approaches used in previous research. The use of various social psychological theories combined with a behavioural addiction framework provided a novel examination of young people’s mobile behaviour. In particular, the development of a new measure of mobile phone behaviour in the research program facilitated the differentiation of the psychosocial factors influencing frequency of young people’s mobile phone behaviour and their level of involvement with their mobile phone. Results of the research program indicate the important role that mobile phone behaviour plays in young people’s social development and also signals the characteristics of those people who may become highly involved with their mobile phone. Future research could build on this thesis by exploring whether mobile phones are affecting traditional social psychological processes and whether the results in this research program are generalisable to other cohorts and other communication technologies.

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This study examines the case of Chinese consumer's intention to adopt the upcoming mobile technology, 3G. The qualitative study involved 45 in-depth intervie3ws undertaken in three major Chemise cities to explore what perceptions, beliefs and attitudes will influence their decisions about adopting 3G. Perceived beliefs about using 3G technology were found to be important determinants. Additionally, there was evidence of influences from their social network that could motivate the adoption behaviour, as well as influence from the secondary information sources, such as the media and the Internet. Finally, some constraints were identifies that may inhibit Chinese consumers' adoption of this technology.

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Pure and Iron incorporated nanostructured Tungsten Oxide (WO3) thin films were investigated for gas sensing applications using noise spectroscopy. The WO3 sensor was able to detect lower concentrations (1 ppm-10 ppm) of NH3, CO, CH4 and Acetaldehyde gases at higher operating temperatures between 100oC to 250oC. The response of the WO3 sensor to NH3, CH4 and Acetaldehyde at lower temperatures (50oC-100oC) was significant when the sensor was photo-activated using blue-light emitting diode (Blue-LED). The WO3 with Fe (WO3:Fe) was found to show some response to Acetaldehyde gas only at relatively higher operating temperature (250oC) and gas concentration of 10 ppm.

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A series of mobile phone prototypes called The Swarm have been developed in response to the user needs identified in a three-year empirical study of young people’s use of mobile phones. The prototypes take cues from user led innovation and provide multiple avatars that allow individuals to define and manage their own virtual identity. This paper briefly maps the evolution of the prototypes and then describes how the pre-defined, color coded avatars in the latest version are being given greater context and personalization through the use of digital images. This not only gives ‘serendipity a nudge’ by allowing groups to come together more easily, it provides contextual information that can reduce gratuitous contact.