504 research outputs found

    Towards Atmospheric Characterisation of Exoplanets

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    This thesis provides a multi-pronged approach towards paving the way for future space and ground based exoplanet characterisation eā†µorts as well as providing new analysis of the atmosphere of the exoplanet HD 179949 b. This is done, firstly, by outlining engineering trade studies conducted for the attitude and orbit control system (AOCS) and sun shield for the Exoplanet Characterisation Observatory (EChO) spacecraft (a proposed European Space Agency exoplanet space mission). These trade studies were conducted in collaboration with EADS Astrium. A cold gas system with the possibility of a hybrid system which would include the use of reaction wheels is recommend for the design of the AOCS. For the sun shield, a V-groove cone shield is concluded to provide the best thermal coverage while also providing stay light protection as well as being more mechanically symmetric than other options. Simulations are then conducted to determine the number of transiting planets future surveys should expect to find around stars within 50 parsecs of the sun. This is done by taking the known stars within 50 parsecs and adding a simulated planet population based on current models and observations to each star. Assumptions are made regarding observability of a planetary transit and a Monte Carlo simulation run to gain statistics on the number and type of planetary systems that can be expected to be found. The results of the simulation show a mean expected number of 27 detectable transiting planets within 50 parsecs. Next, using the Position and Proper Motion Extended-L (PPMXL) catalogue, optical and near-infrared colour cuts were used together with a reduced proper motion cut to find bright M dwarfs for future exoplanet transit studies. PPMXLā€™s low proper motion uncertainties allow this work to probe down to smaller proper motions than previous similar studies. Unique objects found with this method were combined with that of previous work to produce 8479 K < 9 M dwarfs. Low-resolution spectroscopy was obtained of a sample of the objects found using this selection method to gain statistics on their spectral type and physical properties. Results show a spectral-type range of K7-M4V. This catalogue is the most complete collection of K < 9 M dwarfs currently available and is made available here. High resolution spectroscopy and model spectra of planetary atmospheres is then used along with a spectral deconvolution technique to attempt to detect the Doppler shifted signal of the non-transiting planet HD 179949 b. The signal was not detected but new upper limits were set ruling out the presence of TiO down to a log10 āœ0 = -4.09 with 99.9 per cent confidence. Simulations conducted by this work imply a loss of sensitivity occurring possibly due to varying telluric interference or instrumental systematics

    Coextensive space: virtual reality and the developing relationship between the body, the digital and physical space

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    Virtual Reality (VR) has traditionally required external sensors placed around a designated play space. In contrast, more recent wired and wireless systems, such as the Oculus Rift S (released in March 2019) and the Oculus Quest (released in May 2019) use cameras located on the outside of these devices to monitor their physical position. Users can now mark out a physical space that is then digitally tracked within their display. Once a play space has been established, users are alerted if they come close to breaching this boundary by the visual inclusion of a grid. Should this threshold be breached, the headset display shifts to an image of the surrounding concrete environment. We contend that physical space is increasingly being incorporated into the digital space of VR in a manner that meaningfully differs from older systems. We build our argument in the following way. First, the article explores how theories surrounding VR have implicated only a limited relationship with physical space. Second, the article introduces the concept of coextensive space as a way of understanding the developing relationship between the physical, digital and concrete reality enacted by current VR systems

    It Is All About Location: Smartphones and Tracking the Spread of COVID-19

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    Mobile phone location data have become tied to understandings of and responses to the COVID-19 pandemic. Data visualizations have used mobile phone data to inform people about how mobility practices may be linked to the spread of the virus, and governments have explored contact tracing that relies upon mobile phone data. This article examines how these uses of location data implicate three particular issues that have been present in the growing body of locative media research: (1) anonymized data are often not anonymous, (2) location data are not always representative and can exacerbate inequality, and (3) location data are a key part of the extension of the surveillance state

    From hybrid space to dislocated space: Mobile virtual reality and a third stage of mobile media theory

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    Research in the field of mobile communication studies (MCS) has generally moved away from focusing on how mobile phones distract users from their physical environment to considering how the experience of space and place can be enhanced by locative smartphone applications. This article argues that trajectory may be complicated by the emergence of a new type of mobile technology: mobile virtual reality (MVR). While an increasing number of handsets are specifically developed with MVR in mind, there is little to no research that situates this phenomenon within the continuum of MCS. The intention of this paper is accordingly twofold. First, the article conceptualizes MVR as a connective tissue between the two sequential tropes of MCS: physical distraction and spatial enhancement. Second, the article introduces the concept of ā€˜dislocated spaceā€™ as a way of understanding the embodied space MVR might configure

    Quantifying the impact of road lighting on road safety ā€” A New Zealand Study

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    It is well known from the literature that road lighting has significant safety benefits. The NZTA Economic Evaluation Manual (EEM) quotes a 35% reduction in crashes as the effect of upgrading or improving lighting where lighting is poor.However, no well-established doseā€“response relationship to lighting parameters exists from which one can deduce benchmark levels of lighting for safety.This study looked at a sample of street lighting installations spread over the urban areas of nine territorial local authorities. Standard street lighting parameters were measured in the field using a variety of instruments including illuminance meter, luminance meter and digital camera. Field measurements were related to the ratio of night-time to day time crashes as a measure of night time safety vis-a-vis daytime safety.A statistically significant doseā€“response relationship was found between average road luminance and safety across all traffic volume groups, with an indication that the relationship may be stronger where more serious crashes are involved.Threshold increment was also a significant variable but not so longitudinal uniformity or overall uniformity.The results related to luminance will allow practitioners to better estimate the safety benefits of different levels of lighting resulting in better targeting of expenditure. Document type: Articl

    Potentials of bamboo-based agroforestry for sustainable development in Sub-Saharan Africa:a review

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    There is widespread assertion among scientists, government and development experts that bamboo agroforestry could contribute to sustainable rural development in Sub-Saharan Africa (SSA). However, there are limited available data to verify the suitability of the system in the region. In addition, the current state of knowledge and adoption of agroforestry in SSA offers very little guidance as to which type of agroforestry systems bamboo could be integrated. Here, we reviewed the potential socioeconomic and environmental benefits of bamboo agroforestry and accentuate implications on sustainable rural development in SSA. In addition, we analysed potential research areas that could be intensified, so that future developments and scaling-up of bamboo agroforestry can be rooted in robust scientific findings rather than the intuitions of governments and development actors

    Film music and film genre

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    This thesis explores the role that film genre plays in the construction of, predominantly, Hollywood movie scores. It begins with the simple assumption that each genre has its own set of musical conventions, its signature ;quot;paradigm;quot;, with the result that Westerns sound different from Horror films, which sound different from Romantic Melodramas and so on. It demonstrates that while this is broadly speaking so, the true picture is more complex, the essentially hybrid nature of most Hollywood films on a narrative level resulting in scores that are similarly hybrid in nature. To begin with, the various functions of film music are described, and that of generic location is isolated as being of key importance. The concept of film genre is then discussed, with particular reference to the notion of hybridity. The substance and sources of the musical paradigms of the Western, Horror film and Romantic Melodrama are described in depth; specific aspects of the War Film, Gangster, Thriller and Action paradigms are addressed more briefly. The thesis concludes with a cue by cue analysis of John Barry's score for Dances with Wolves (1990), demonstrating that while the dominant paradigm the music draws on is indeed that of the Western, the score also incorporates elements from a variety of other generic paradigms, shifts in musical emphasis that are dictated by the changing requirements of the narrative. Film music is shown to be profoundly influenced by film genre, but that the use of generically specific music is as complex and nuanced as cinema's negotiation of genre at narrative level. While genres do indeed have signature musical paradigms, these do not exist discretely, but in constant tension with and relation to one another.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Unconvincing statistical and functional inferences : reply to Catmur

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    A commentary on Unconvincing support for role of mirror neurons in ā€œaction understandingā€: com-mentary on Michael et al. (2014) by Catmur, C. (2014). Front. Hum
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