365 research outputs found

    A framework for experimental determination of localised vertical pedestrian forces on full-scale structures using wireless attitude and heading reference systems

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    A major weakness among loading models for pedestrians walking on flexible structures proposed in recent years is the various uncorroborated assumptions made in their development. This applies to spatio-temporal characteristics of pedestrian loading and the nature of multi-object interactions. To alleviate this problem, a framework for the determination of localised pedestrian forces on full-scale structures is presented using a wireless attitude and heading reference systems (AHRS). An AHRS comprises a triad of tri-axial accelerometers, gyroscopes and magnetometers managed by a dedicated data processing unit, allowing motion in three-dimensional space to be reconstructed. A pedestrian loading model based on a single point inertial measurement from an AHRS is derived and shown to perform well against benchmark data collected on an instrumented treadmill. Unlike other models, the current model does not take any predefined form nor does it require any extrapolations as to the timing and amplitude of pedestrian loading. In order to assess correctly the influence of the moving pedestrian on behaviour of a structure, an algorithm for tracking the point of application of pedestrian force is developed based on data from a single AHRS attached to a foot. A set of controlled walking tests with a single pedestrian is conducted on a real footbridge for validation purposes. A remarkably good match between the measured and simulated bridge response is found, indeed confirming applicability of the proposed framework

    A framework for experimental determination of localised vertical pedestrian forces on full-scale structures using wireless attitude and heading reference systems

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.A major weakness among loading models for pedestrians walking on flexible structures proposed in recent years is the various uncorroborated assumptions made in their development. This applies to spatio- temporal characteristics of pedestrian loading and the nature of multi-object interactions. To alleviate this problem, a framework for the determination of localised pedestrian forces on full-scale structures is presented using a wireless attitude and heading reference systems (AHRS). An AHRS comprises a triad of tri-axial accelerometers, gyroscopes and magnetometers managed by a dedicated data processing unit, allowing motion in three-dimensional space to be reconstructed. A pedestrian loading model based on a single point inertial measurement from an AHRS is derived and shown to perform well against benchmark data collected on an instrumented treadmill. Unlike other models, the current model does not take any predefined form nor does it require any extrapolations as to the timing and amplitude of pedestrian loading. In order to assess correctly the influence of the moving pedestrian on behaviour of a structure, an algorithm for tracking the point of application of pedestrian force is developed based on data from a single AHRS attached to a foot. A set of controlled walking tests with a single pedestrian is conducted on a real footbridge for validation purposes. A remarkably good match between the measured and simulated bridge response is found, indeed confirming applicability of the proposed framework.The research presented here was funded by EPSRC (grant EP/I029567/2). Authors thank Devon County Council for permitting the experimental campaign to be conducted on Baker Bridge in Exeter, UK, and Dr Erfan Shahabpour (supported by EPSRC grant EP/K03877X/1) for providing access to and assisting with measurements on the ADAL-3D treadmill at the University of Sheffield (funded by EPSRC grant EP/E018734/1)

    Technology and Management for Sustainable Buildings and Infrastructures

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    A total of 30 articles have been published in this special issue, and it consists of 27 research papers, 2 technical notes, and 1 review paper. A total of 104 authors from 9 countries including Korea, Spain, Taiwan, USA, Finland, China, Slovenia, the Netherlands, and Germany participated in writing and submitting very excellent papers that were finally published after the review process had been conducted according to very strict standards. Among the published papers, 13 papers directly addressed words such as sustainable, life cycle assessment (LCA) and CO2, and 17 papers indirectly dealt with energy and CO2 reduction effects. Among the published papers, there are 6 papers dealing with construction technology, but a majority, 24 papers deal with management techniques. The authors of the published papers used various analysis techniques to obtain the suggested solutions for each topic. Listed by key techniques, various techniques such as Analytic Hierarchy Process (AHP), the Taguchi method, machine learning including Artificial Neural Networks (ANNs), Life Cycle Assessment (LCA), regression analysis, Strength–Weakness–Opportunity–Threat (SWOT), system dynamics, simulation and modeling, Building Information Model (BIM) with schedule, and graph and data analysis after experiments and observations are identified

    Language-Learner Computer Interactions

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    This book focuses on learner-computer interactions (LCI) in second language learning environments drawing largely on sociocultural theories of language development. It brings together a rich and varied range of theoretical discussions and applications in order to illustrate the way in which LCI can enrich our comprehension of technology-mediated communication, hence enhancing learners’ digital literacy skills. The book is based on the premise that, in order to fully understand the nature of language and literacy development in digital spaces, researchers and practitioners in linguistics, sciences and engineering need to borrow from each others’ theoretical and practical toolkits. In light of this premise, themes include such aspects as educational ergonomics, affordances, complex systems learning, learner personas and corpora, while also describing such data collecting tools as video screen capture devices, eye-tracking or intelligent learning tutoring systems

    On the design and analysis of compliant mechanisms using the pseudo-rigid-body model concept

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    The pseudo-rigid-body model (PRBM) concept, developed for the analysis and design of large-deflection flexible members, has proved over time to be a simple, efficient and accurate tool for the synthesis, analysis and design of compliant mechanisms. This dissertation investigates a variety of compliant mechanism analysis and design problems using the PRBM concept and assists in further advancement of the implementation of the PRBMs. The dissertation begins with the development of a PRBM for a fixed-guided compliant beam with one inflection point in the deformed state. This research investigation advances the concept of characteristic deflection domain to a new synthesis framework for the design of fully-compliant mechanisms containing fixed-guided segments with an inflection point. The dissertation then formalizes a new approach for the evaluation of mechanical advantage of compliant mechanisms. In order to extend the approach towards synthesis and design of compliant mechanisms with higher mechanical advantage, the dissertation revisits the synthesis with compliance method of compliant mechanism design and provides an implementation strategy. A new method to determine an appropriate PRBM is presented. The method also allows determination of the expected static mode shape(s) of a given compliant mechanism structural configuration. Finally, the dissertation provides experimental results to validate the simplicity, accuracy, efficiency and applicability of the PRBM concept towards the synthesis, analysis and design of compliant segments and compliant mechanisms. The test setup design utilized for the experimental investigations may be found in the addendum to this dissertation. --Abstract, page iii

    Proceedings of the 2017 Coal Operators\u27 Conference

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    Proceedings of the 2017 Coal Operators\u27 Conference. All papers in these proceedings are peer reviewed. ISBN: 978174128261

    Enhancing the mechanical efficiency of skilled rowing through shortened feedback cycles

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    In elite level rowing competition, the average velocities of medallists differ by less than 1 % over 2000 m. Nations place sporting excellence in high regard and this magnifies the importance of success. As a result, sports science and technology is increasingly used to achieve marginal performance gains. This research considers how to advance biomechanical analysis and skills training provision with a particular focus on the technical and practical delivery of real-time feedback to coaches and athletes, thereby shortening the amount of time between feedback cycles. Underpinning any biomechanical feedback intervention, validated determinants of performance are required. Previous research revealed that, while gross biomechanical measures such as athlete power, stroke rate and stroke length have previously been used as key determinants of performance, elite athletes are nowadays performing within expected ranges and therefore it is no longer possible to easily differentiate crews using these measures alone. This thesis describes workshops held with elite coaches to investigate biomechanical efficiency where the outcomes led to a focus on how a boat accelerates and decelerates during a stroke and hence how the boat's velocity fluctuates. Novel metrics are proposed to quantify aspects of a stroke cycle and used to analyse an elite data set, collected using a standardised protocol. It is shown that individual elite rowers can be successfully differentiated and benchmark values of performance are presented. Consideration of previous research suggests that there is currently no suitably functional and flexible biomechanical real-time feedback system to deliver complex skills training in rowing. Therefore, this thesis describes the research that has led to the development and evaluation of new technology to deliver visual and audible interfaces that support the delivery of concurrent and terminal feedback in water and land-based environments. Coaches and athletes were involved throughout the design process to optimise system suitability and encourage adoption. The technology empowers a coach to intricately manipulate feedback provision, thereby promoting motor control and learning theory best practice. Novel insights relevant to designing interactive systems for use within an elite sporting population are also discussed. This research presents an end-to-end strategy for the applied delivery of real-time feedback to skilled rowers bringing together engineering and social science disciplines. A land-based case series reveals that while statistically significant skill learning was not achieved, participants acquired sport specific technical awareness and heightened motivation as a result of the skills training intervention. Existing motor learning literature was tested as part of the study with a key finding being the lack of support for audible display of stroke acceleration through frequency modulation. Study limitations were identified that explain the lack of an effect of skills training on rower efficiency. The study also acted as a validation of the use of a land-based simulator to monitor and manipulate stroke velocity and a validation of the candidate feedback interfaces that had been implemented. As of result of this work, rowing coaches are able to evaluate their athletes in a novel way, achieving a deeper appreciation of their biomechanical efficiency. Upon identifying athletes with a need for technical development, coaches can intervene with the proposed methodology of skill development making use of the new technologies developed to deliver performance gains. This methodology would achieve enhanced validity through a deeper understanding of the reliability of the new metrics and their relationship to boat speed. Future attempts to test for skill learning should build upon the findings made in this work and, in due course, technology and theory should combine to deliver terminal feedback training during water-based rowing

    SPARC 2019 Fake news & home truths : Salford postgraduate annual research conference book of abstracts

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    Welcome to the Book of Abstracts for the 2019 SPARC conference. This year we not only celebrate the work of our PGRs but also our first ever Doctoral School Best Supervisor awards, which makes this year’s conference extra special. Once again we have received a tremendous contribution from our postgraduate research community; with over 90 presenters, the conference truly showcases a vibrant, innovative and collaborative PGR community at Salford. These abstracts provide a taster of the inspiring, relevant and impactful research in progress, and provide delegates with a reference point for networking and initiating critical debate. Find an abstract that interests you, and say “Hello” to the author. Who knows what might result from your conversation? With such wide-ranging topics being showcased, we encourage you to take up this great opportunity to engage with researchers working in different subject areas from your own. To meet global challenges, high impact research needs interdisciplinary collaboration. This is recognised and rewarded by all major research funders. Engaging with the work of others and forging collaborations across subject areas is an essential skill for the next generation of researchers. Even better, our free ice cream van means that you can have those conversations while enjoying a refreshing ice lolly

    Latent Print Examination and Human Factors: Improving the Practice Through a Systems Approach: The Report of the Expert Working Group on Human Factors in Latent Print Analysis

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    Fingerprints have provided a valuable method of personal identification in forensic science and criminal investigations for more than 100 years. Fingerprints left at crime scenes generally are latent prints—unintentional reproductions of the arrangement of ridges on the skin made by the transfer of materials (such as amino acids, proteins, polypeptides, and salts) to a surface. Palms and the soles of feet also have friction ridge skin that can leave latent prints. The examination of a latent print consists of a series of steps involving a comparison of the latent print to a known (or exemplar) print. Courts have accepted latent print evidence for the past century. However, several high-profile cases in the United States and abroad have highlighted the fact that human errors can occur, and litigation and expressions of concern over the evidentiary reliability of latent print examinations and other forensic identification procedures has increased in the last decade. “Human factors” issues can arise in any experience- and judgment-based analytical process such as latent print examination. Inadequate training, extraneous knowledge about the suspects in the case or other matters, poor judgment, health problems, limitations of vision, complex technology, and stress are but a few factors that can contribute to errors. A lack of standards or quality control, poor management, insufficient resources, and substandard working conditions constitute other potentially contributing factors

    Meeting the Psychological Needs of Astronauts in the Flourishing Human Spaceflight Frontier: The Case for Astronaut-Trained Psychologists

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    Space psychology (i.e., astronaut psychological counseling and support) has remained largely unchanged since the onset of long-duration low-Earth-orbit (LEO) human spaceflight missions, with teletherapy utilized as the primary means of psychotherapy delivery. However, with NASA’s plans to establish a permanent human presence on the Moon, the suitability of teletherapy – as well as astronaut-trained psychologists, an alternative space psychology method suggested for human spaceflight beyond LEO – must be ascertained. The aim of this novel space psychology investigation was to identify and compare the effectiveness of three astronaut psychotherapy treatment conditions (i.e., teletherapy with a 2 second Earth to LEO latency, teletherapy with a 10 second Earth to Moon latency, and in-person astronaut trained psychologist delivered therapy with practically no latency) at reducing stress levels among astronauts/astronaut-surrogates in an analogue human spaceflight environment. 24 screened astronaut-surrogates randomly underwent each of the astronaut psychotherapy treatments, and no astronaut-surrogate received repeated treatments. Stress indicators (i.e., heart rate, blood pressure, and self-reported perceived stress questionnaire scores) were measured at multiple intervals throughout the psychotherapy treatment sessions and were analyzed via repeated measures ANOVA. By all metrics, the astronaut-trained psychologist treatment significantly outperformed both teletherapy treatments at reducing stress; and teletherapy with 10 second latency was deemed unsuitable for astronauts. Thus, astronaut-trained psychologists appear to be the most efficacious feasibly integrable space psychology solution for improving wellbeing and reducing stress among individual astronauts and astronaut crews in future long duration human spaceflight operations and missions beyond LEO (e.g., NASA’s Artemis Lunar mission). Additionally, astronaut-trained psychologists appear to be highly effective when operating in LEO as well, and therefore are also ideal for space tourism and commercial astronaut applications
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