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Quality-of-Information Aware Sensing Node Characterisation for Optimised Energy Consumption in Visual Sensor Networks
No full textEnergy consumption is one of the primary concerns in a resource constrained visual sensor network (VSN) with wireless transceiving capability. The existing VSN design solutions under particular resource constrained scenarios are application-specific, whereas the degree of sensitivity of the resource constraints varies from one application to another. This limits the implementation of the existing energy efficient solutions within a VSN node, which may be considered to be a part of a heterogeneous network. This thesis aims to resolve the energy consumption issues faced within VSNs because of their resource constrained nature by proposing energy efficient solutions for sensing nodes characterisation.
The heterogeneity of image capture and processing within a VSN can be adaptively reflected with a dynamic field-of-view (FoV) realisation. This is expected to allow the implementation of a generalised energy efficient solution that will adapt with the heterogeneity of the network. In this thesis, a FoV characterisation framework is proposed, which can assist design engineers during the pre-deployment phase in developing energy efficient VSNs. The proposed FoV characterisation framework provides efficient solutions for: 1) selecting suitable sensing range; 2) maximising spatial coverage; 3) minimising the number of required nodes; and 4) adaptive task classification. The task classification scheme proposed in this thesis exploits heterogeneity of the network and leads to an optimal distribution of tasks between visual sensing nodes. Soft decision criteria is exploited, and it is observed that for a given detection reliability, the proposed FoV characterisation framework provides energy efficient solutions which can be implemented within heterogeneous networks.
In the post-deployment phase, the energy efficiency of a VSN for a given level of reliability can be enhanced by reconfiguring its nodes dynamically to achieve optimal configurations. Considering the dynamic realisation of quality-of-information (QoI), a strategy is devised for selecting suitable configurations of visual sensing nodes to reduce redundant visual content prior to transmission without sacrificing the expected information retrieval reliability. By incorporating QoI awareness using peak signal-to-noise ratio-based representative metric, the distributed nature of the proposed self-reconfiguration scheme accelerates the decision making process.
This thesis also proposes a unified framework for node classification and dynamic self-reconfiguration in VSNs. For a given application, the unified framework provides a feasible solution to classify and reconfigure visual sensing nodes based on their FoV by exploiting the heterogeneity of targeted QoI within the sensing region. From the results, it is observed that for the second degree of heterogeneity in targeted QoI, the unified framework outperforms its existing counterparts and results in up to 72% energy savings with as low as 94% reliability. Within the context of resource constrained VSNs, the substantial energy savings achieved by the proposed unified framework can lead to network lifetime enhancement. Moreover, the reliability analysis demonstrates suitability of the unified framework for applications that need a desired level of QoI
Healthy competition: A qualitative study investigating persuasive technologies and the gamification of cycling
Get PDFChanging socio-technical practices occurring within cycling are leading the pursuit, and its participants, to become ever more embedded into the networked digital world. GPS enabled mobile-technologies have introduced a new element of competition into recreational riding, whether on the road, competing over timed virtual segments, or online dissecting and comparing the data that has been logged and shared via dedicated ride-logging applications. In order to understand these technologies qualitative study using reflective diaries and semi-structured interviews has been conducted with experienced club cyclists who had fully experienced the effects of their arrival. These riders claim that the applications influence their route choice and motivate them to cycle more frequently, and at a greater intensity although the engagement changes over time. This paper explores how this increased motivation to exercise and compete is instigated, manifested and maintained in the everyday practices of cyclists, as well as the negative consequences of gamification
EFFECTS OF FOOTWEAR VARIATIONS ON THREE-DIMENSIONAL KINEMATICS AND TIBIAL ACCELERATIONS OF SPECIFIC MOVEMENTS IN AMERICAN FOOTBALL
No full textNatural outdoor environments and mental health: Stress as a possible mechanism.
Get PDFINTRODUCTION
Better mental health has been associated with exposure to natural outdoor environments (NOE). However, comprehensive studies including several indicators of exposure and outcomes, potential effect modifiers and mediators are scarce.
OBJECTIVES
We used novel, objective measures to explore the relationships between exposure to NOE (i.e. residential availability and contact) and different indicators of mental health, and possible modifiers and mediators.
METHODS
A nested cross-sectional study was conducted in: Barcelona, Spain; Stoke-on-Trent, United Kingdom; Doetinchem, Netherlands; Kaunas, Lithuania. Participants' exposure to NOE (including both surrounding greenness and green and/or blue spaces) was measured in terms of (a) amount in their residential environment (using Geographical Information Systems) and (b) their contact with NOE (using smartphone data collected over seven days). Self-reported information was collected for mental health (psychological wellbeing, sleep quality, vitality, and somatisation), and potential effect modifiers (gender, age, education level, and city) and mediators (perceived stress and social contacts), with additional objective NOE physical activity (potential mediator) derived from smartphone accelerometers.
RESULTS
Analysis of data from 406 participants showed no statistically significant associations linking mental health and residential NOE exposure. However, NOE contact, especially surrounding greenness, was statistically significantly tied to better mental health. There were indications that these relationships were stronger for males, younger people, low-medium educated, and Doetinchem residents. Perceived stress was a mediator of most associations, and physical activity and social contacts were not.
CONCLUSIONS
Our findings indicate that contact with NOE benefits mental health. Our results also suggest that having contact with NOE that can facilitate stress reduction could be particularly beneficial
The Secrets of Shakespeare’s Grave.
No full textThe grave of William Shakespeare is one of the most famous, and most visited, burials in England. But what lies beneath the strangely-shaped stone bearing his name, and are 19th-century legends of graverobbers and stolen bones true? Kevin Colls reports on the first-ever archaeological investigation of the playwright’s tomb – and its surprising findings
Chapter 7 Reflecting on emotionally enabled practice
No full textThis chapter focuses on the emotional work involved when working with very young children
The Design and Implementation of Multiple Choice Questions (MCQs) in Forensic Science Assessment
No full textThis chapter introduces some of the literature surrounding multiple choice questions (MCQs) and their design and implementation. Designing a collection of questions for MCQ formative and summative assessments is the first step towards implementation. The next stage is to identify where, when and how to use them. The variety of uses and design features that are offered by MCQ assessments means that they are very useful in forensic science education and can be robustly utilised to assess the skills desired from an individual required to work in the criminal justice system. The effect of chance and answer guessing in MCQ tests and test reliability has been explored by Burton (2001). Burton shows methods for quantifying the effects of chance so that appropriate test length and number of answer options can be more reliably designed
DC Line Protection for Multi-Terminal High Voltage DC (HVDC) Transmission Systems
Get PDFThe projected global energy shortage and concerns about greenhouse emissions have led to the significant developments in offshore wind farm projects around the globe. It is also envisaged that in the near future, a number of existing onshore converter stations and offshore stations will be interconnected to form a Multi-terminal (MT) HVDC systems, whereas protection issues remains a major challenge. This is largely due to the low inductance in DC network compared to AC interconnection which usually results in a sudden collapse in the DC voltage and rapid rise in the fault current thus reaching damaging levels in few milliseconds. Therefore faults in MT-HVDC system must be detected and cleared quickly before it reaches a damaging level; typically 4 – 6ms (including circuit breaker opening time) following the inception of the fault. For this reason, transient based protection techniques are ideal candidates if the protection scheme must be reliable and dependable. Transient based protection algorithms utilises the higher frequency components of the fault generated signal to detect a fault, therefore making it possible to detect the fault while the fault current is still rising and well before the steady state. The traditional protection algorithms developed for conventional high voltage AC (HVAC) systems such as distance protection are steady state based and as such not suitable for the protection of MT-HVDC systems. Another major issue is selectivity as only the faulty section must be isolated in the event of a fault. This constitutes a major challenge considering the anticipated lengths of the cables. Traditional protection techniques developed for two-terminal HVDC systems are also not suitable for MT-HVDC since it will de-energise the entire network and other sub-grids connected to the main network. DC line protection devices which will operate at a sufficient speed and which will isolate only the faulty section in the event of a fault are therefore required to avoid a total system failure during short circuit. It is anticipated that it will be achieved by the use of HVDC breakers, whereas the implementation and realisation of such circuit breakers still remain a major issue considering speed, complexity, losses and cost. However, two major vendors have proposed prototypes and hopefully these will be commercially available in the near future. The key issue still remains the development of a fast DC line fault detection algorithm; and it is on these premise that this research was undertaken. The work reported in this thesis is a novel time domain protection technique for application to HVDC grids.
The protection principle developed utilises the “power” and “energy” accompanying the associated travelling wave following the occurrence of a fault to distinguish between internal and external fault. Generally, either the “power” or “energy” can provide full discrimination between internal and external faults. For an internal fault, the associated forward and backward travelling wave power; or the forward and backward wave energy must exceed a pre-determined setting otherwise the fault is regarded as external. This characteristic differences is largely due to the DC inductor located at the boundaries which provides attenuation for the high frequency transient resulting from an external fault, hence making the power and energy for an internal fault to be significantly larger than that for external fault. The ratio between the forward and backward travelling wave power; or between the forward and backward travelling wave energy provides directional discrimination. For a forward directional fault (FDF) with respect to a local relay, this ratio must be less than unity. However, the ratio is greater than unity for reverse directional faults (RDF).
The resulting wave shape of the “travelling wave power” (TWP) components also led to the formulation of a novel protection algorithm utilising the wave shape concavity. For an internal fault, the second derivative of the resulting polynomial formed by the TWP must be negative, thereby indicating a “concave-upwards” parabola. However, for an external fault, the second derivative of the resulting polynomial formed by the TWP components must be positive indicating a “concave-downwards” parabola.
The developed and proposed protection techniques and principles were validated against a full scale Modular Multi-level Converter (MMC) – based HVDC grid, and thereafter the protection algorithm was implemented in MATLAB. Wider cases of fault scenarios were considered including long distance remote internal fault and a 500Ω high resistance remote internal fault. In all cases, both the pole-pole (P-P) and pole-ground (P-G) faults were investigated. The simulation results presented shows the suitability of the protection technique as the discrimination between internal and external faults was made within 1ms following the application of the fault.
Following this, the protection algorithm was implemented on both a low-cost experimental platform utilising an Arduino UNO ATmega328 Microcontroller and on a Compact RIO FPGA-based experimental platform utilising LAB-View. The experimental results obtained were consistent with those obtained by simulations.
An advantage of the proposed technique is that it is non-unit based and as such no communication delays are incurred. Furthermore, as it is time domain - based, it does not require complex mathematical computation and burden / DSP techniques; hence can easily be implemented since it will require less hardware resources which ultimately will result in minimal cost
FACTORY. Neil Brownsword
No full textThis catalogue was published in conjunction with the Invitational Exhibition of Neil Brownsword's FACTORY held at the Icheon World Ceramic Center, which was presented as an incentive to the Grand Prize winner of the International Competition of GICB 2015. It brings together texts by Brownsword, Prof. Ezra Shales art historian at Massachusetts College of Art and Design in Boston, and Tim Strangleman is Professor in Sociology at the University of Kent. It explores the research and contexts underpinning the FACTORY project together with themes that include the sociology of nostalgia, deindustrialisation and the sociology of work.
Foreword
Since the 1970s and 80s, progressive deindustrialisation in the United States and in Western Europe has resulted in many profound social, political and economic transformations across the globe. Displacement of productive industrial capacity has in many cases accelerated urban decline, outmigration and gentrification. High culture has tended to be the universal panacea where policies of regeneration assimilate former sites of production into art venues and cultural spaces, transforming industrial ruins into aestheticized backdrops for leisurely consumption.
Following decades of industrial transition, Stoke-on- Trent - the historic capital of British ceramic manufacture, is one such city that today remains at the early phase of its contemporary repurposing. Yet narratives that explore the recent collapse of industry or the communities still affected by the legacy of deindustrialisation remain inconvenient truths eschewed by many in local government and organisations profiting from culture led redevelopment. Finding value in the active memory and former practices of those affected by industrial change often provokes simple assumptions of nostalgia, or an unchecked idealisation of the past. Thus, the psychological and emotional dimensions of industrial history - the first-hand recollections surrounding the complex networks, social bonds and pride forged by collective skill, can be all too easily side-lined. Factory is a performative installation that reflects upon notions of place, skill, people and material objects left behind following the process of industrial change. In Stoke-on-Trent, global outsourcing together with high yield production technologies, have substituted many of the people-embodied skills that once sustained company leadership. Like many hand skills in the ceramic industry, dexterity is transmitted from generation to generation. As the tertiary or service sector has largely replaced traditional manufacturing there now exists a signifi- cant skills gap, and with few apprenticeships a danger of specialist knowledge disappearing. Following the legacy of William Morris and the Arts and Craft Movement in the nineteenth and early twentieth centuries, much attention has been dedicated to the preservation of vernacular crafts. Since these neo-traditionalists remained diametrically opposed to industrialisation, they also marginalised the know-how of those employed in factories, albeit sometimes unintentionally. In 2003 UNESCO implemented a convention to safeguard intangible cultural heritage. 171 countries have now endorsed this, effectively making Intangible Heritage part of their cultural policy, but this value system remains alien to the UK.
Any efforts to safeguard traditional craftsmanship must focus not on preserving craft objects - no matter how beautiful, precious, rare or important they might be - but on creating conditions that will encourage artisans to continue to produce crafts of all kinds, and to transmit their skills and knowledge to others.
Factory re-evaluates explicit systems of know-how, specific to North Staffordshire’s ceramic industry. Within this exhibition, china flower maker Rita Floyd and mould maker James Adams, two artisans with long careers working and residing in Stoke-on-Trent, restaged their former working practices. Yet the live transmission of these contrasting modes of ceramic manufacture in the gallery space were not intended as nostalgic demonstrations of pure skill constructed for heritage tourism. To accentuate these overlooked forms of intelligence, numerous strategies that disrupt and renavigate prescriptive skill are adopted to offer rare access into haptic and material knowledge from the routines of the production line. Staging Factory in South Korea, a country that gives status to individuals with exceptional cultural ability to preserve and cultivate living heritage, has provided a prestigious platform to question the value and relevance of embodied practices that continue to remain marginalised in the very nation where the industrial revolution began
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