Publications

Search or filter publications

Filter by type:

Filter by publication type

Filter by year:

to

Results

  • Showing results for:
  • Reset all filters

Search results

  • Journal article
    Duckworth H, Azor A, Wischmann N, Zimmerman KA, Tanini I, Ghajari Met al., 2022,

    A finite element model of cerebral vascular injury for predicting microbleeds location

    , Frontiers in Bioengineering and Biotechnology, Vol: 10, ISSN: 2296-4185

    Finite Element (FE) models of brain mechanics have improved our understanding of the brain response to rapid mechanical loads that produce traumatic brain injuries. However, these models have rarely incorporated vasculature, which limits their ability to predict the response of vessels to head impacts. To address this shortcoming, here we used high-resolution MRI scans to map the venous system anatomy at a submillimetre resolution. We then used this map to develop an FE model of veins and incorporated it in an anatomically detailed FE model of the brain. The model prediction of brain displacement at different locations was compared to controlled experiments on post-mortem human subject heads, yielding over 3,100 displacement curve comparisons, which showed fair to excellent correlation between them. We then used the model to predict the distribution of axial strains and strain rates in the veins of a rugby player who had small blood deposits in his white matter, known as microbleeds, after sustaining a head collision. We hypothesised that the distribution of axial strain and strain rate in veins can predict the pattern of microbleeds. We reconstructed the head collision using video footage and multi-body dynamics modelling and used the predicted head accelerations to load the FE model of vascular injury. The model predicted large axial strains in veins where microbleeds were detected. A region of interest analysis using white matter tracts showed that the tract group with microbleeds had 95th percentile peak axial strain and strain rate of 0.197 and 64.9 s−1 respectively, which were significantly larger than those of the group of tracts without microbleeds (0.163 and 57.0 s−1). This study does not derive a threshold for the onset of microbleeds as it investigated a single case, but it provides evidence for a link between strain and strain rate applied to veins during head impacts and structural damage and allows for future work to generate threshold valu
  • Conference paper
    Valk S, Chen Y, Nguyen M, Toivonen T, Mougenot Cet al., 2022,

    Ideation and Consequence Scanning Beyond Human Perspectives in Biodesign

    , Design Research Society 2022

    Biodesign is an emerging interdisciplinary field which is accelerated by recent advance-ments in biotechnology and engineering. The field offers novel opportunities to design in-novative processes, products, services, materials and experiences. However, designing with the living and incorporating organisms into human-centric solutions raises critical ques-tions about ethics, handling of species, human dominated power dynamics and exploitative behaviours. The purpose of this workshop is to explore and discuss these critical questions from more than human perspectives and acknowledge biases in biodesign. The workshop offers an opportunity for this exploration through two interactive activities: firstly, bi-odesign idea generation with support from Design x Science cards, and secondly, conse-quence scanning – a guided activity that provides an opportunity to mitigate potential harms and innovate responsibly. An expected outcome of the workshop is shared under-standing about potential implications of biodesign innovations on nonhuman collaborators. Participants can also expect to experience use of a novel creativity support tool for bi-odesign ideation. This workshop is inviting participants with diverse backgrounds and interests (interdisciplinary ideation, bio-sciences, innovation, responsible design, multispecies ethics) with or without prior related experience). We aim to build a connected interdisci-plinary community within DRS that can positively impact the emergence of responsible bioeconomy.
  • Book chapter
    Cardin M-A, Mijic A, Whyte J, 2022,

    Flexibility and real options in engineering systems design

    , Handbook of Engineering Systems Design, Editors: Maier, Oehmen, Vermaas, Publisher: Springer, Pages: 1-29, ISBN: 978-3-030-46054-9

    Designing engineering systems for flexibility is of utmost importance for future generations of systemsdesigners and operators. As a core system property, flexibility provides systems owners and operators with the abilityto respond easily and cost-effectively to future changes. It contributes to improved economic value, sustainability andresilience by enabling systems to adapt and reconfigure in the face of uncertainty in operations, markets, regulations,and technology. The field of Flexibility in Design has steadily evolved over the last two decades, emerging from thearea of Real Options Analysis, which focuses on quantifying the value of flexibility in large-scale, irreversibleinvestment projects. Flexibility in Design goes further by developing and evaluating novel design methods andcomputational procedures to enable flexibility as a systematic value enhancement mechanism in engineering systems.This chapter provides an overview of how the field has developed over time as well as design frameworks, methodsand procedures to support such design activities in practice. It discusses important challenges and limitations withsupporting case studies in aerospace, automotive, energy, real estate, transportation, and water management. Thechapter highlights key future directions for research, involving sustainability and resilience, data-driven real options,empirical studies and simulation games, machine learning, digital twin modelling, and 3D virtualization.
  • Journal article
    Gundry D, Deterding S, 2022,

    Trading Accuracy for Enjoyment? Data Quality and Player Experience in Data Collection Games

    <p>Games have become a popular way of collecting human subject data, based on the premise that they are more engaging than surveys or experiments, but generate equally valid data. However, this premise has not been empirically tested. In response, we designed a game for eliciting linguistic data following Intrinsic Elicitation – a design approach aiming to minimise validity threats in data collection games – and compared it to an equivalent linguistics experiment as control. In a preregistered study and replication (n=96 and n=136), using two different ways of operationalising accuracy, the game generated substantially more enjoyment (d=.70, .73) and substantially less accurate data (d=-.68, -.40) – though still more accurate than random responding. We conclude that for certain data types data collection games may present a serious trade-of between participant enjoyment and data quality, identify possible causes of lower data quality for future research, reflect on our design approach, and urge games HCI researchers to use careful controls where appropriate.</p>
  • Journal article
    Yu X, Wu T, Nguyen T-TN, Ghajari Met al., 2022,

    Investigation of blast-induced cerebrospinal fluid cavitation: Insights from a simplified head surrogate

    , International Journal of Impact Engineering, Vol: 162, Pages: 1-9, ISSN: 0734-743X

    Blast induced traumatic brain injury (bTBI) has been a prevalent injury in recent conflicts. Post-mortem studies have shown damage in the brain tissue close to the cerebrospinal fluid (CSF) in bTBI cases compared to non-blast TBI cases. CSF cavitation is a potential mechanism for this brain/CSF interface injury. In this study, our aim was to explore the possibility and mechanism of blast induced CSF cavitation. We first developed a one-dimensional simplified human head surrogate and exposed it to nonlethal blast waves using a shock tube. High-speed videography and pressure sensors data showed the formation and collapse of cavitation in the CSF simulant. Then, we explored the mechanism of the cavitation using a finite element model of the head surrogate. We found that the pressure waves transmitting through the skull (outer wave) and tissue simulants (inner wave) are responsible for the generation and collapse of the cavitation bubbles, respectively. Next, we used this insight to explore the possibility of CSF cavitation in the human head using a detailed finite element model. The simulations verified the role of the inner and outer waves in the generation and collapse of cavitation. Our results suggested that CSF cavitation is likely to happen in the human head under blast loading. Finally, we studied the CSF cavitation in head surrogate models with different lengths. The results showed that the head length significantly affected the CSF cavitation, indicating the potential drawback of using small animals to study bTBI in human head. Our findings can improve our understanding of the brain/CSF interface injury after blast exposure and inform the design of protection systems and animal tests.
  • Conference paper
    Nguyen QT, Laly M, Kwon BC, Mougenot C, McNamara Jet al., 2022,

    Moody Man: Improving creative teamwork through dynamic affective recognition

    , CHI 2022 - ACM CHI Conference on Human Factors in Computing Systems, Publisher: ACM, Pages: 1-14

    While a significant part of communication in the workplace is now happening online, current platforms don’t fully support socio-cognitive nonverbal communication, which hampers the shared understanding and creativity of virtual teams. Given text-based communication being the main channel for virtual collaboration, we propose a novel solution leveraging an AI-based, dynamic affective recognition system. The app provides live feedback about the affective content of the communication in Slack, in the form of a visual representation and percentage breakdown of the ‘sentiment’ (tone, emoji) and main ‘emotion states’ (e.g. joy, anger). We tested the usability of the app in a quasi-experiment with 30 participants from diverse backgrounds, linguistic analysis and user interviews. The findings show that the app significantly increases shared understanding and creativity within virtual teams. Emerged themes included impression formation assisted by affective recognition, supporting long-term relationships development; identified challenges related to transparency and emotional complexity detected by AI.
  • Journal article
    Drake A, Sassoon I, Balatsoukas P, Porat T, Ashworth M, Wright E, Curcin V, Chapman M, Kokciyan N, Modgil S, Sklar E, Parsons Set al., 2022,

    The relationship of socio-demographic factors and patient attitudes to connected health technologies: A survey of stroke survivors

    , HEALTH INFORMATICS JOURNAL, Vol: 28, ISSN: 1460-4582
  • Journal article
    Bessa RJ, Pinson P, Kariniotakis G, Srinivasan D, Smith C, Amjady N, Zareipour Het al., 2022,

    Guest Editorial for the Special Section on Advances in Renewable Energy Forecasting: Predictability, Business Models and Applications in the Power Industry

    , IEEE TRANSACTIONS ON SUSTAINABLE ENERGY, Vol: 13, Pages: 1166-1168, ISSN: 1949-3029
  • Journal article
    Yao X, Samoril T, Dluhos J, Watts JF, Du Z, Son B, Silva SRP, Sui T, Zhao Yet al., 2022,

    Degradation Diagnostics from the Subsurface of Lithium-Ion Battery Electrodes

    , ENERGY & ENVIRONMENTAL MATERIALS, Vol: 5, Pages: 662-669
  • Journal article
    Cox-Pridmore DM, Castro FA, Silva SRP, Camelliti P, Zhao Yet al., 2022,

    Emerging Bioelectronic Strategies for Cardiovascular Tissue Engineering and Implantation

    , SMALL, Vol: 18, ISSN: 1613-6810
  • Conference paper
    Cox-Pridmore D, Zhao Y, Castro F, Camelliti P, Silva Ret al., 2022,

    EMBEDDING FLEXIBLE BIOELECTRONICS WITHIN 3D SCAFFOLDS FOR CELLULAR INTERROGATION AND CARDIAC TISSUE ENGINEERING.

    , 6th World Congress of the Tissue-Engineering-and-Regenerative-Medicine-International-Society (TERMIS), Publisher: MARY ANN LIEBERT, INC, Pages: S478-S479, ISSN: 1937-3341
  • Journal article
    Yu Z, Sadati SMH, Hauser H, Childs PRN, Nanayakkara Tet al., 2022,

    A semi-supervised reservoir computing system based on tapered whisker for mobile robot terrain identification and roughness estimation

    , IEEE Robotics and Automation Letters, Vol: 7, Pages: 5655-5662, ISSN: 2377-3766

    Identifying terrain type is important for safely operating robots exploration in unstructured environments. In this letter, we firstly proposed a novel tapered whisker-based semi-supervised reservoir computing (TWSSRC) system for improving terrain classification and terrain property estimation for traversability assessment with low computing cost. Three Hall sensors are used to capture the vibration at different locations of the tapered whisker. It could provide morphological computation power to achieve frequency separation in the time domain simultaneously without any data procession and only with the help of an additional simple linear regression, different signals can be classified. The movement of the robot on different types of terrain will result in different vibration behaviors of the whiskers and the whiskered robot can learn from prior physical experiences through cost-efficient self-supervised reservoir computing to achieve auto-labeling of new terrain and terrain classification. Experimental results demonstrate that this method can achieve good performance when the robot encounters new terrain and can accurately estimate the property of the unknown terrain surface at different robot speeds.
  • Journal article
    Ai W, Kirkaldy N, Jiang Y, Offer G, Wang H, Wu Bet al., 2022,

    A composite electrode model for lithium-ion batteries with silicon/graphite negative electrodes

    , Journal of Power Sources, Vol: 527, Pages: 231142-231142, ISSN: 0378-7753

    Silicon is a promising negative electrode material with a high specific capacity, which is desirable for com-mercial lithium-ion batteries. It is often blended with graphite to form a composite anode to extend lifetime,however, the electrochemical interactions between silicon and graphite have not been fully investigated. Here,an electrochemical composite electrode model is developed and validated for lithium-ion batteries with asilicon/graphite anode. The continuum-level model can reproduce the voltage hysteresis and demonstratethe interactions between graphite and silicon. At high states-of-charge, graphite provides the majority of thereaction current density, however this rapidly switches to the silicon phase at deep depths-of-discharge due tothe different open circuit voltage curves, mass fractions and exchange current densities. Furthermore, operationat high C-rates leads to heterogeneous current densities in the through-thickness direction, where peak reactioncurrent densities for silicon can be found at the current collector–electrode side as opposed to the separator–electrode side for graphite. Increasing the mass fraction of silicon also highlights the beneficial impacts ofreducing the peak reaction current densities. This work, therefore, gives insights into the effects of siliconadditives, their coupled interactions and provides a platform to test different composite electrodes for betterlithium-ion batteries.
  • Journal article
    Ge Y, Nanayakkara T, Dulantha Lalitharatne T, 2022,

    Origami inspired design for capsule endoscope to retrograde using intestinal peristalsis

    , IEEE Robotics and Automation Letters, Vol: 7, Pages: 5429-5435, ISSN: 2377-3766

    Capsule endoscopy has gained a lot of attentionin the medical field in the recent past as an effective way ofinvestigating unusual symptoms experienced in places such asesophagus, stomach, small intestine and colon. However, motioncontrol of the capsule endoscope is challenging and often requiresa power source and miniature actuators. To address these issues,we present a novel origami inspired structure as an attachmentto the capsule endoscope. The proposed origami structure utilizesthe wave generated by peristalsis of the intestine to move itforward and backward. When the origami structure is folded, thecapsule endoscope is propelled forward by intestinal peristalsis.When the origami structure is unfolded, the intestinal peristalsissqueezes the origami structure to drive the capsule endoscope tomove in the opposite direction. Therefore, folding and unfoldingof the proposed origami structure would allow to control themovement direction of the capsule endoscope. In this paper, wepresent the design, simulations and experimental validation ofthe proposed origami structure.
  • Journal article
    Magson NR, Van Zalk N, Mörtberg E, Chard I, Tillfors M, Rapee RMet al., 2022,

    Latent stability and change in subgroups of social anxiety and depressive symptoms in adolescence: a latent profile and transitional analysis

    , Journal of Anxiety Disorders, Vol: 87, Pages: 1-11, ISSN: 0887-6185

    BackgroundSocial anxiety and depressive symptoms increase markedly during adolescence. Most research examining the emergence of these symptoms has used a variable-centered approach providing little information about how these symptoms group together in individuals over time.MethodA person-centered approach utilizing latent profile and latent transitional analyses was applied to a large adolescent sample (N = 2742, Mage=13.65; SD=0.63; 47.9% girls). Subgroups differing in their expressions of social anxiety and depressive symptoms at each of four annual time points were identified and then change in membership of these groups was evaluated.ResultsFour subgroups were identified: 1. Low Distress, 2. Socially Anxious, 3. Dysphoric, and 4. Comorbid. The low distress group was the largest and most stable, followed by the socially anxious group, who most commonly transitioned into the comorbid group. In contrast, the dysphoric group were most likely to remit and move to the low distress group. The comorbid group was the smallest and least stable, although once in this group, three quarters of adolescents remained in this group over time.ConclusionEarly intervention is particularly imperative for socially anxious adolescents with or without comorbid depressive symptoms as they are the least likely to improve across the adolescent years.
  • Journal article
    Yu Z, Perera S, Hauser H, Childs P, Nanayakkara Tet al., 2022,

    A tapered whisker-based physical reservoir computing system for mobile robot terrain identification in unstructured environments

    , IEEE Robotics and Automation Letters, Vol: 7, Pages: 3608-3615, ISSN: 2377-3766

    In this letter, we present for the first time the use of tapered whisker-based reservoir computing (TWRC) system mounted on a mobile robot for terrain classification and roughness estimation of unknown terrain.Hall effect sensors captured the oscillations at different locations along a tapered spring that served as a reservoir to map time-domain vibrations signals caused by the interaction perturbations from the ground to frequency domain features directly. Three hall sensors are used to measure the whisker reservoir outputs and these temporal signals could be processed efficiently by the proposed TWRC system which can provide morphological computation power for data processing and reduce the model training cost compared to the convolutional neural network (CNN) approaches.To predict the unknown terrain properties, an extended TWRC method including a novel detector is proposed based on the Mahalanobis distance in the Eigen space, which has been experimentally demonstrated to be feasible and sufficiently accurate.We achieved a prediction success rate of 94.3\% for six terrain surface classification experiments and 88.7\% for roughness estimation of the unknown terrain surface.
  • Journal article
    Wu H, Porter M, Ward R, Quinn J, McGarrigle C, McFadden Set al., 2022,

    Investigation of the mechanical properties of friction drilling with 6082-T6 aluminium alloy

    , Materials (Basel), Vol: 15, ISSN: 1996-1944

    Friction drilling is a non-conventional hole-making process suitable for thin-section, ductile metals. During friction drilling, heat is generated due to tool rotation and the resulting flow of metal creates a bushing on the exit side of the hole. The bushing offers a longer engagement length for any subsequent thread making process. The threaded holes in this study were created by friction drilling and thread forming in 6082-T6 aluminium alloy. Four scenarios of the threaded holes were created with four levels of rotation rates of friction drilling processes (2000 rpm to 4000 rpm) and the mechanical properties of the threaded holes were compared. It was shown that 3000-3500 rpm is the optimum range of the rotation rate that achieved the higher load-bearing capacities (i.e., resistance to thread stripping) of 5.0-5.5 kN. In addition, the regions close to the thread surfaces in all scenarios were found to have experienced localised hardening to a hardness from 113 HV to around 125 HV.
  • Conference paper
    Hänsel K, Sobolev M, Kowatsch T, Calvo RAet al., 2022,

    HEALTHI: Workshop on Intelligent Healthy Interfaces

    , Pages: 7-9

    The second workshop on intelligent healthy interfaces (HEALTHI), collocated with the 2022 ACM Intelligent User Interfaces (IUI) conference, offers a forum that brings academics and industry researchers together and seeks submissions broadly related to the design of healthy user interfaces. The workshop will discuss intelligent user interfaces such as screens, wearables, voices assistants, and chatbots in the context of accessibly supporting health, health behavior, and wellbeing.
  • Journal article
    Ballou N, Deterding S, Iacovides I, Helsby Let al., 2022,

    Do People Use Games to Compensate for Psychological Needs During Crises? A Mixed-Methods Study of Gaming During COVID-19 Lockdowns

    <p>Do people use games to cope with adverse life events and crises? Research informed by self-determination theory proposes that people might compensate for thwarted basic psychological needs in daily life by seeking out games that satisfy those lacking needs. To test this, we conducted a preregistered mixed-method survey study (n = 285) on people’s gaming behaviours and need states during early stages of the COVID-19 pandemic (May 2020). We found qualitative evidence that gaming was an often actively sought out and successful means of replenishing particular needs, but one that could ‘backfire’ for some through an appraisal process discounting gaming as ‘unreal’. Meanwhile, contrary to our predictions, the quantitative data showed a “rich get richer, poor get poorer” pat- tern: need satisfaction in daily life positively correlated with need satisfaction in games. We derive methodological considerations and propose three potential explanations for this contradictory data pattern to pursue in future research.</p>
  • Journal article
    Saksida A, Ghiselli S, Picinali L, Pintonello S, Battelino S, Orzan Eet al., 2022,

    Attention to speech and music in young children with bilateral cochlear implants: a pupillometry study

    , The Journal of Clinical Sleep Medicine, Vol: 11, Pages: 1-14, ISSN: 1550-9389

    Early bilateral cochlear implants (CIs) may enhance attention to speech, and reduce cognitive load in noisy environments. However, it is sometimes difficult to measure speech perception and listening effort, especially in very young children. Behavioral measures cannot always be obtained in young/uncooperative children, whereas objective measures are either difficult to assess or do not reliably correlate with behavioral measures. Recent studies have thus explored pupillometry as a possible objective measure. Here, pupillometry is introduced to assess attention to speech and music in noise in very young children with bilateral CIs (N = 14, age: 17–47 months), and in the age-matched group of normally-hearing (NH) children (N = 14, age: 22–48 months). The results show that the response to speech was affected by the presence of background noise only in children with CIs, but not NH children. Conversely, the presence of background noise altered pupil response to music only in in NH children. We conclude that whereas speech and music may receive comparable attention in comparable listening conditions, in young children with CIs, controlling for background noise affects attention to speech and speech processing more than in NH children. Potential implementations of the results for rehabilitation procedures are discussed.
  • Journal article
    Harkin R, Wu H, Nikam S, Yin S, Lupoi R, McKay W, Walls P, Quinn J, McFadden Set al., 2022,

    Powder reuse in laser-based powder bed fusion of Ti6Al4V-changes in mechanical properties during a powder top-up regime

    , Materials (Basel), Vol: 15, ISSN: 1996-1944

    The properties of Extra Low Interstitials (ELI) Ti6Al4V components fabricated via the laser-based powder bed fusion (L-PBF) process are prone to variation, particularly throughout a powder reuse regime. Interstitial pick-up of interstitial elements within the build chamber during processing can occur, most notably, oxygen, nitrogen, and hydrogen, which can impair the mechanical properties of the built component. This study analyses ELI Ti6Al4V components manufactured by the L-PBF process when subjected to a nine-stage powder reuse sequence. Mechanical properties are reported via hardness measurement and tensile testing. Results showed that from 0.099 wt.% to 0.126 wt.% oxygen content, the mean hardness and tensile strength increased from 367.8 HV to 381.9 HV and from 947.6 Mpa to 1030.7 Mpa, respectively, whereas the ductility (area reduction) reduced from around 10% to 3%. Statistical analysis based on the empirical model from Tabor was performed to determine the strength-hardness relationship. Results revealed a significant direct relationship between tensile strength and Vickers hardness with a proportionality constant of 2.61 (R-square of 0.996 and p-value of 6.57 × 10-6).
  • Journal article
    Yu X, Ghajari M, 2022,

    Protective performance of helmets and goggles in mitigating brain biomechanical response to primary blast exposure

    , Annals of Biomedical Engineering, Vol: 50, Pages: 1579-1595, ISSN: 0090-6964

    The current combat helmets are primarily designed to mitigate blunt impacts and ballistic loadings. Their protection against primary blast wave is not well studied. In this paper, we comprehensively assessed the protective capabilities of the advanced combat helmet and goggles against blast waves with different intensity and directions. Using a high-fidelity human head model, we compared the intracranial pressure (ICP), cerebrospinal fluid (CSF) cavitation, and brain strain and strain rate predicted from bare head, helmet-head and helmet-goggles-head simulations. The helmet was found to be effective in mitigating the positive ICP (24-57%) and strain rate (5-34%) in all blast scenarios. Goggles were found to be effective in mitigating the positive ICP in frontal (6-16%) and lateral (5-7%) blast exposures. However, the helmet and goggles had minimal effects on mitigating CSF cavitation and even increased brain strain. Further investigation showed that wearing a helmet leads to higher risk of cavitation. In addition, their presence increased the head kinetic energy, leading to larger strains in the brain. Our findings can improve our understanding of the protective effects of helmets and goggles and guide the design of helmet pads to mitigate brain responses to blast.
  • Journal article
    Tan Y, Rerolle S, Lalitharathne TD, Zalk NV, Jack R, Nanayakkara Tet al., 2022,

    Simulating dynamic facial expressions of pain from visuo-haptic interactions with a robotic patient

    , Scientific Reports, Vol: 12, ISSN: 2045-2322

    Medical training simulators can provide a safe and controlled environment for medical students to practice their physical examination skills. An important source of information for physicians is the visual feedback of involuntary pain facial expressions in response to physical palpation on an affected area of a patient. However, most existing robotic medical training simulators that can capture physical examination behaviours in real-time cannot display facial expressions and comprise a limited range of patient identities in terms of ethnicity and gender. Together, these limitations restrict the utility of medical training simulators because they do not provide medical students with a representative sample of pain facial expressions and face identities, which could result in biased practices. Further, these limitations restrict the utility of such medical simulators to detect and correct early signs of bias in medical training. Here, for the first time, we present a robotic system that can simulate facial expressions of pain in response to palpations, displayed on a range of patient face identities. We use the unique approach of modelling dynamic pain facial expressions using a data-driven perception-based psychophysical method combined with the visuo-haptic inputs of users performing palpations on a robot medical simulator. Specifically, participants performed palpation actions on the abdomen phantom of a simulated patient, which triggered the real-time display of six pain-related facial Action Units (AUs) on a robotic face (MorphFace), each controlled by two pseudo randomly generated transient parameters: rate of change β and activation delay τ. Participants then rated the appropriateness of the facial expression displayed in response to their palpations on a 4-point scale from “strongly disagree” to “strongly agree”. Each participant (n=16, 4 Asian females, 4 Asian males, 4 White females and 4 White males) performed 200 palpation
  • Conference paper
    Zhao Y, Afzal SS, Akbar W, Rodriguez O, Mo F, Boyle D, Adib F, Haddadi Het al., 2022,

    Towards battery-free machine learning and inference in underwater environments

    , HotMobile '22: The 23rd International Workshop on Mobile Computing Systems and Applications, Publisher: ACM, Pages: 29-34

    This paper is motivated by a simple question: Can we design and build battery-free devices capable of machine learning and inference in underwater environments? An affirmative answer to this question would have significant implications for a new generation of underwater sensing and monitoring applications for environmental monitoring, scientific exploration, and climate/weather prediction.To answer this question, we explore the feasibility of bridging advances from the past decade in two fields: battery-free networking and low-power machine learning. Our exploration demonstrates that it is indeed possible to enable battery-free inference in underwater environments. We designed a device that can harvest energy from underwater sound, power up an ultra-low-power microcontroller and on-board sensor, perform local inference on sensed measurements using a lightweight Deep Neural Network, and communicate the inference result via backscatter to a receiver. We tested our prototype in an emulated marine bioacoustics application, demonstrating the potential to recognize underwater animal sounds without batteries. Through this exploration, we highlight the challenges and opportunities for making underwater battery-free inference and machine learning ubiquitous.
  • Working paper
    O'Kane SEJ, Ai W, Madabattula G, Alvarez DA, Timms R, Sulzer V, Edge JS, Wu B, Offer GJ, Marinescu Met al., 2022,

    Lithium-ion battery degradation: how to model it

    , Publisher: Royal Society of Chemistry

    Predicting lithium-ion battery degradation is worth billions to the globalautomotive, aviation and energy storage industries, to improve performance andsafety and reduce warranty liabilities. However, very few published models ofbattery degradation explicitly consider the interactions between more than twodegradation mechanisms, and none do so within a single electrode. In thispaper, the first published attempt to directly couple more than two degradationmechanisms in the negative electrode is reported. The results are used to mapdifferent pathways through the complicated path dependent and non-lineardegradation space. Four degradation mechanisms are coupled in PyBaMM, an opensource modelling environment uniquely developed to allow new physics to beimplemented and explored quickly and easily. Crucially it is possible to see'inside' the model and observe the consequences of the different patterns ofdegradation, such as loss of lithium inventory and loss of active material. Forthe same cell, five different pathways that can result in end-of-life havealready been found, depending on how the cell is used. Such information wouldenable a product designer to either extend life or predict life based upon theusage pattern. However, parameterization of the degradation models remains as amajor challenge, and requires the attention of the international batterycommunity.
  • Journal article
    Stratton E, Lampit A, Choi I, Malmberg Gavelin H, Aji M, Taylor J, Calvo RA, Harvey SB, Glozier Net al., 2022,

    Are Organizational EHealth Interventions Becoming More Effective at Addressing Employee Mental Health; A Systematic Review and Meta-Analysis (Preprint)

    <sec> <title>BACKGROUND</title> <p>Mental health conditions are considered the leading cause of disability, sickness absence, and long-term work incapacity in most developed countries. EHealth interventions provide employees with access to psychological assistance. There has been widespread implementation and provision of eHealth interventions in the workplace as an inexpensive and anonymous way of addressing common mental disorders</p> </sec> <sec> <title>OBJECTIVE</title> <p>The aims of this updated review were to synthesize the literature of the efficacy of eHealth interventions for anxiety, depression, and stress outcomes in employee samples in organisational settings, and evaluate whether their effectiveness has improved over time.</p> </sec> <sec> <title>METHODS</title> <p>Systematic searches in relevant articles published from 2004 - July 2020 of trials of eHealth interventions (App or web-based) focused on the mental health of employees. The quality and bias of all studies was assessed. We extracted means and standard deviations from publications, comparing the difference in effect sizes (Hedge’s g) in standardized mental health outcomes. We meta-analyzed these using a random effects model.</p> </sec> <sec> <title>RESULTS</title> <p>We identified a tripling of the body of evidence, with 75 trials available for meta-analysis, with a combined sample of n=14,747. EHealth interventions showed small positive effects for anxiety (g=0.26), depression (g=0.26), and stress (g=0.25) in employees’ post-intervention, with simila
  • Journal article
    Basak S, Tavabi AH, Dzieciol K, Migunov V, Arszelewska V, Tempel H, Kungl H, Kelder EM, Wagemaker M, George C, Mayer J, Dunin-Borkowski RE, Eichel R-Aet al., 2022,

    <i>Operando</i> transmission electron microscopy of battery cycling: thickness dependent breaking of TiO<sub>2</sub> coating on Si/SiO<sub>2</sub> nanoparticles

    , CHEMICAL COMMUNICATIONS, Vol: 58, Pages: 3130-3133, ISSN: 1359-7345
  • Journal article
    Posirisuk P, Baker C, Ghajari M, 2022,

    Computational prediction of head-ground impact kinematics in e-scooter falls

    , Accident Analysis and Prevention, Vol: 167, Pages: 1-11, ISSN: 0001-4575

    E-scooters are the fastest growing mode of micro-mobility with important environmental benefits. However, there are serious concerns about injuries caused by e-scooter accidents. Falls due to poor road surface conditions are a common cause of injury in e-scooter riders, and head injuries are one of the most common and concerning injuries in e-scooter falls. However, the head-ground impact biomechanics in e-scooter falls and its relationship with e-scooter speed and design, road surface conditions and wearing helmets remain poorly understood. To address some of these key questions, we predicted the head-ground impact force and velocity of e-scooter riders in different falls caused by potholes. We used multi-body dynamics approach to model a commercially available e-scooter and simulate 180 falls using human body models. We modelled different pothole sizes to test whether the pothole width and depth influences the onset of falls and head-ground impact speed and force. We also tested whether the e-scooter travelling speed has an influence on the head-ground impact force and velocity. The simulations were carried out with three human body models to ensure that the results of the study are inclusive of a wide range of rider sizes. For our 10inch diameter e-scooter wheels, we found a sudden increase in the occurrence of falls when the pothole depth was increased from 3cm (no falls) to 6cm (41 falls out of 60 cases). When the falls occurred, we found a head-ground impact force of 13.23.4kN, which is larger than skull fracture thresholds. The head-ground impact speed was 6.31.4m/s, which is nearly the same as the impact speed prescribed in bicycle helmet standards. All e-scooter falls resulted in oblique head impacts, with an impact angle of 6510 (measured from the ground). Decreasing the e-scooter speed reduced the head impact speed. For instance, reducing the e-scooter speed from 30km/h to 20km/h led to a 14% reduction in the mean impact speed and 12% reduction in th
  • Journal article
    Liu S, Zhang R, Mao J, Zhao Y, Cai Q, Guo Zet al., 2022,

    From room temperature to harsh temperature applications: Fundamentals and perspectives on electrolytes in zinc metal batteries

    , SCIENCE ADVANCES, Vol: 8, ISSN: 2375-2548
  • Journal article
    Roe C, Feng X, White G, Li R, Wang H, Rui X, Li C, Zhang F, Null V, Parkes M, Patel Y, Wang Y, Wang H, Ouyang M, Offer G, Wu Bet al., 2022,

    Immersion cooling for lithium-ion batteries – a review

    , Journal of Power Sources, Vol: 525, Pages: 231094-231094, ISSN: 0378-7753

    Battery thermal management systems are critical for high performance electric vehicles, where the ability to remove heat and homogenise temperature distributions in single cells and packs are key considerations. Immersion cooling, which submerges the battery in a dielectric fluid, has the potential of increasing the rate of heat transfer by 10,000 times relative to passive air cooling. In 2-phase systems, this performance increase is achieved through the latent heat of evaporation of the liquid-to-gas phase transition and the resulting turbulent 2-phase fluid flow. However, 2-phase systems require additional system complexity, and single-phase direct contact immersion cooling can still offer up to 1,000 times improvements in heat transfer over air cooled systems. Fluids which have been considered include: hydrofluoroethers, mineral oils, esters and water-glycol mixtures. This review therefore presents the current state-of-the-art in immersion cooling of lithium-ion batteries, discussing the performance implications of immersion cooling but also identifying gaps in the literature which include a lack of studies considering the lifetime, fluid stability, material compatibility, understanding around sustainability and use of immersion for battery safety. Insights from this review will therefore help researchers and developers, from academia and industry, towards creating higher power, safer and more durable electric vehicles.

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.

Request URL: http://www.imperial.ac.uk:80/respub/WEB-INF/jsp/search-t4-html.jsp Request URI: /respub/WEB-INF/jsp/search-t4-html.jsp Query String: id=1221&limit=30&resgrpMemberPubs=true&page=14&resgrpMemberPubs=true&respub-action=search.html Current Millis: 1722721753390 Current Time: Sat Aug 03 22:49:13 BST 2024