Publications
91 results found
Aggarwal G, Mansfield N, Vanheusden F, et al., 2022, Human Comfort Model of Noise and Vibration for Sustainable Design of the Turboprop Aircraft Cabin, SUSTAINABILITY, Vol: 14
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- Citations: 2
Mansfield NJ, Aggarwal G, 2022, Whole-Body Vibration Experienced by Pilots, Passengers and Crew in Fixed-Wing Aircraft: A State-of-the-Science Review, VIBRATION, Vol: 5, Pages: 110-120
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- Citations: 8
Agrebi HZ, Benhadj N, Chaieb M, et al., 2021, Integrated Optimal Design of Permanent Magnet Synchronous Generator for Smart Wind Turbine Using Genetic Algorithm, ENERGIES, Vol: 14
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- Citations: 11
Iizuka M, Goto R, Siegkas P, et al., 2021, Large Deformation Finite Element Analyses for 3D X-ray CT Scanned Microscopic Structures of Polyurethane Foams, MATERIALS, Vol: 14
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- Citations: 4
Zakeri Z, Mansfield N, Sunderland C, et al., 2020, Cross-validating models of continuous data from simulation and experiment by using linear regression and artificial neural networks, Informatics in Medicine Unlocked, Vol: 21, ISSN: 2352-9148
We are increasingly surrounded by sensors gathering massive amounts of data, and patterns in continuous variables are often discovered by using artificial neural networks (ANN), while linear regression (LR) is useful for detecting linear relationships. LR also provide preliminary estimates of potentially complex associations, and serve as a benchmark for the performance of ANNs. We show that while cross-validation (CV) is indispensable for insuring the robustness of the discovered patterns, it systematically leads, when combined with LR, to specific artefacts that underestimate the extent of the associations between predictor and target variables. We explain how this previously unnoticed type of artefact arises specifically from the combination of CV with LR and does not affect non-linear methods such as ANN. We also demonstrate through simulations that ANN were able to discover a wide range of complex associations missed by LR. The results were confirmed by the analysis of physiological, behavioural and subjective data collected from N = 31 human subjects performing laparoscopy training experiments.
Mansfield N, Naddeo A, Frohriep S, et al., 2020, Integrating and applying models of comfort, APPLIED ERGONOMICS, Vol: 82, ISSN: 0003-6870
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- Citations: 28
Sammonds GM, Mansfield NJ, Fray M, 2017, Improving long term driving comfort by taking breaks - How break activity affects effectiveness, APPLIED ERGONOMICS, Vol: 65, Pages: 81-89, ISSN: 0003-6870
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- Citations: 6
Blaxter L, Yeo M, McNally D, et al., 2017, Neonatal head and torso vibration exposure during inter-hospital transfer, Proceedings of the Institution of Mechanical Engineers Part H - Journal of Engineering in Medicine, Vol: 231, Pages: 99-113, ISSN: 0954-4119
Inter-hospital transport of premature infants is increasingly common, given the centralisation of neonatal intensive care. However, it is known to be associated with anomalously increased morbidity, most notably brain injury, and with increased mortality from multifactorial causes. Surprisingly, there have been relatively few previous studies investigating the levels of mechanical shock and vibration hazard present during this vehicular transport pathway. Using a custom inertial datalogger, and analysis software, we quantify vibration and linear head acceleration. Mounting multiple inertial sensing units on the forehead and torso of neonatal patients and a preterm manikin, and on the chassis of transport incubators over the duration of inter-site transfers, we find that the resonant frequency of the mattress and harness system currently used to secure neonates inside incubators is ~9Hz. This couples to vehicle chassis vibration, increasing vibration exposure to the neonate. The vibration exposure per journey (A(8) using the ISO 2631 standard) was at least 20% of the action point value of current European Union regulations over all 12 neonatal transports studied, reaching 70% in two cases. Direct injury risk from linear head acceleration (HIC15) was negligible. Although the overall hazard was similar, vibration isolation differed substantially between sponge and air mattresses, with a manikin. Using a Global Positioning System datalogger alongside inertial sensors, vibration increased with vehicle speed only above 60 km/h. These preliminary findings suggest there is scope to engineer better systems for transferring sick infants, thus potentially improving their outcomes.
Mansfield NJ, 2016, Ranking of Design Journals Based on Results of the UK Research Excellence Framework: Using REF as Referee, The Design Journal, Vol: 19, Pages: 903-919, ISSN: 1756-3062
Design researchers disseminate their work through many outlets. Journals have been, and continue to be, a vital conduit by which research methods and results are reported. Journal paper authors want their work to be published in the best possible titles, but ranking of journals is notoriously difficult and always controversial. This paper takes a new approach to finding a referee to rank journal popularity: analysis of the results of the 2014 UK Research Excellence Framework (REF), Art and Design panel. Institutional submissions that scored best in terms of research output ‘originality, significance and rigour’ had the highest proportion of print (journal and book) outputs. The journals in which papers selected by submitting institutions were published were analysed to determine the most common titles. When filtered to include the highest ranked ‘design’ submissions, the most popular design-focused journal titles were The Design Journal, Applied Ergonomics, Ergonomics, Journal of Design Research and Design Issues. There was no correlation between journal citation metrics and the analysis of REF results indicating that quality assessments require detailed individual scrutiny of outputs. The methodology used has limitations: the data is only based on UK institutions submitting to the Art and Design panel, the method of counting journals may skew results towards larger titles with more papers published, and the results from REF do not allow for scrutiny of individual outputs.
Karali S, Mansfield NJ, Gyi DE, 2016, An approach to vehicle design: in-depth audit to understand the needs of older drivers, Applied Ergonomics, Vol: 58, Pages: 461-470, ISSN: 1872-9126
The population of older people continues to increase around the world, and this trend is expected to continue; the population of older drivers is increasing accordingly. January 2012 figures from the DVLA in the UK stated that there were more than 15 million drivers aged over 60; more than 1 million drivers were aged over 80. There is a need for specific research tools to understand and capture how all users interact with features in the vehicle cabin e.g. controls and tasks, including the specific needs of the increasingly older driving population. This paper describes an in-depth audit that was conducted to understand how design of the vehicle cabin impacts on comfort, posture, usability, health and wellbeing in older drivers. The sample involved 47 drivers (38% female, 62% male). The age distribution was: 50-64 (n=12), 65-79 (n=20), and those 80 and over (n=15).The methodology included tools to capture user experience in the vehicle cabin and functional performance tests relevant to specific driving tasks. It is shown that drivers’ physical capabilities reduce with age and that there are associated difficulties in setting up an optimal driving position such that some controls cannot be operated as intended, and many adapt their driving cabins. The cabin set-up process consistently began with setting up the seat and finished with operation of the seat belt.
Sammonds GM, Fray M, Mansfield NJ, 2016, Effect of long term driving on driver discomfort and its relationship with seat fidgets and movements (SFMs), Applied Ergonomics, Vol: 58, Pages: 119-127, ISSN: 1872-9126
Discomfort in vehicle seats is a multifactorial problem with large increases in discomfort occurring during extended duration driving. Due to the nature of driver discomfort, previous research has found it difficult to accurately quantify long term driver discomfort via the use of objective measures. This paper reports a laboratory study that investigates a novel objective measure of long term driver discomfort and its correlation with subjective discomfort ratings. Analysis of driver’s seat fidgets and movements was conducted over the duration of a 140 min drive on a driving simulator in addition to collecting subjective ratings of discomfort. It is shown that as subjects’ subjective discomfort increases, the frequency of subjects’ seat fidgets and movements increases congruently. A large correlation is observed between the subjective and objective measures of driver discomfort and provides the opportunity for long term discomfort evaluations to be made via remote monitoring; removing the need for subjective assessment.
Karali S, Gyi DE, Mansfield NJ, 2016, Driving a better driving experience: a questionnaire survey of older compared with younger drivers, Ergonomics, Vol: 60, Pages: 533-540, ISSN: 1366-5847
A questionnaire survey of drivers (n = 903) was conducted covering musculoskeletal symptoms, the vehicle seat, access to specific vehicle features, ingress/egress, driving performance and driving behaviours. Significantly, more discomfort was reported by older drivers (aged 65+) in the hips/thighs/buttocks and knees. Older drivers reported more difficulty parallel parking (p ≤ 0.01), driving on a foggy day (p ≤ 0.01), and turning their head and body to reverse (p ≤ 0.001). They also reported that their reactions were slower than they used to be (p ≤ 0.01). Dissatisfaction was found by all drivers with adjusting the headrest (height and distance), seat belt height and opening/closing the boot. There is a growing population of older people globally, and the number of older drivers is showing a parallel increase. Clearly, efforts are needed to ensure car design of the future is more inclusive of older drivers.
Key J, Morris A, Mansfield NJ, 2016, Situation Awareness: its proficiency amongst older and younger drivers, and its usefulness for perceiving hazards., Transportation Research Part F: Traffic Psychology and Behaviour, Vol: 40, Pages: 156-168, ISSN: 1873-5517
The two studies reported here sought to measure and compare the Situation Awareness (SA) of younger and older driver groups whilst driving (Study 1), and watching video footage of actual car journeys (Study 2). In both studies this was achieved by recording a participant’s commentary on what s/he felt was of relevance to the driving task. The narratives produced were analysed by computer software that could abstract main concepts and calculate scores indicative of Situation Awareness. In Study 2, these scores were related to others for hazard perception proficiency (also derived from participant commentaries). It was found that the older drivers matched and often exceeded the younger drivers when their SA scores were compared individually, but not when assessed as a group. However, the younger drivers outâperformed their older counterparts in hazard perception ability, and this was shown to be related to their Situation Awareness score. When the results from participants who undertook both studies were compared, it was found that Situation Awareness performance was significantly higher when commenting on video footage (Study 2) than whilst actually driving (Study 1).
Mansfield NJ, Mandal BB, 2016, Contribution of Individual Components of a Job Cycle on Overall Severity of Whole-Body Vibration Exposure: A Study in Indian Mines, International Journal of Occupational Safety and Ergonomics, Vol: 22, Pages: 142-151, ISSN: 1080-3548
Drivers of earth-moving machines are exposed to whole-body vibration (WBV). In mining operations there can be a combination of relatively high magnitudes of vibration and long exposure times. Effective risk mitigation requires understanding of the main aspects of a task that pose a hazard to health. There are very few published studies of WBV exposure that have been carried out in India. This paper reports a study that considered the contribution of the component phases of dumper operations, on the overall vibration exposure of the drivers. It shows that vibration magnitudes are relatively high, and that haulage tasks are main contributor to the exposure. It is recommended that driver speed, haul road surfaces and vehicle maintenance/selection are optimised to ensure minimisation of vibration. If this is not sufficient, operation times might need to be reduced in order to ensure that the health guidance caution zone from Standard No. ISO 2631-1:1997 is not exceeded.
Mansfield N, Sammonds G, Linh N, 2015, Driver discomfort in vehicle seats - Effect of changing road conditions and seat foam composition, APPLIED ERGONOMICS, Vol: 50, Pages: 153-159, ISSN: 0003-6870
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- Citations: 41
Mansfield NJ, Hulshof CTJ, 2015, Foreword to 5th International Conference on Whole Body Vibration Injuries held at Academic Medical Center, University of Amsterdam, The Netherlands, 5-7 June 2013, ERGONOMICS, Vol: 58, Pages: 1061-1062, ISSN: 0014-0139
Smith J, Mansfield N, Gyi D, et al., 2015, Driving performance and driver discomfort in an elevated and. standard driving position during a driving simulation, APPLIED ERGONOMICS, Vol: 49, Pages: 25-33, ISSN: 0003-6870
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- Citations: 17
Mansfield NJ, Hazlett B, 2015, Lab trials on trial: Preferred postures in an automotive test rig (BUCK) and the real vehicle, Pages: 482-487
During research and during development of vehicles, it is commonplace for tests of concepts to be performed in a test rig (often referred to as a ‘buck’). Test volunteers might be asked to set a comfortable driving position in the buck. It is assumed that the position set up in the buck is representative of the production vehicle. This paper tests this assumption, by comparing the postures that were selected by 20 drivers in the laboratory using a buck with dimensions, pedals, steering wheel and seat identical to a production vehicle (Nissan NV200) with those that were selected in the real vehicle. It is shown that differences in postural angles between a buck and real vehicle were generally small but varied according to location.
Corrie H, Brooke-Wavell K, Mansfield NJ, et al., 2015, Effects of vertical and side-alternating vibration training on fall risk factors and bone turnover in older people at risk of falls, AGE AND AGEING, Vol: 44, Pages: 115-122, ISSN: 0002-0729
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- Citations: 28
Rimell AN, Mansfield NJ, Paddan GS, 2015, Design of digital filters for frequency weightings (A and C) required for risk assessments of workers exposed to noise, INDUSTRIAL HEALTH, Vol: 53, Pages: 21-27, ISSN: 0019-8366
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- Citations: 15
Morgan LJ, Mansfield NJ, 2014, A survey of expert opinion on the effects of occupational exposures to trunk rotation and whole-body vibration, ERGONOMICS, Vol: 57, Pages: 563-574, ISSN: 0014-0139
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- Citations: 23
Mansfield NJ, Mackrill J, Rimell AN, et al., 2014, Combined Effects of Long-Term Sitting and Whole-Body Vibration on Discomfort Onset for Vehicle Occupants, ISRN Automotive Engineering, Vol: 2014
Occupants of automobiles experience discomfort after long drives, irrespective of how well designed a seat might be. Previous studies of discomfort during driving have focused either on the seat shape and materials (“static” properties), long-term discomfort (“fatigue” properties), or dynamics (“vibration” properties). These factors have previously not been considered together. This paper reports three studies with objectives to define and test a model for describing long-term discomfort from vibration. Study 1 was an independent measures laboratory trial using an automobile seat, which lasted 80 minutes; Study 2 was a repeated measures laboratory trial using a rail passenger seat, which lasted 60 minutes; Study 3 was a repeated measures field trial in a people carrier automobile, which involved 70 minutes of travelling. The findings showed that discomfort accrues with time but that more discomfort is experienced when subjects are also exposed to whole-body vibration. Exposure to whole-body vibration accelerates development of discomfort. The relationship between the reported discomfort, the vibration magnitude, and the exposure time can be described using a multifactorial linear model. It is concluded that ignoring parts of the multi-factorial model (i.e., static, dynamic, or temporal factors) will compromise understanding of discomfort in context.
Mansfield NJ, 2013, Human Response to Vehicle Vibration, AUTOMOTIVE ERGONOMICS: DRIVER-VEHICLE INTERACTION, Editors: Gkikas, Publisher: CRC PRESS-TAYLOR & FRANCIS GROUP, Pages: 77-95, ISBN: 978-1-4398-9425-5
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- Citations: 2
Zhao Y, Hignett S, Mansfield NJ, 2012, Development and Testing of a New Computerized Link Analysis System, HUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Vol: 24, Pages: 479-488, ISSN: 1090-8471
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- Citations: 1
Paddan GS, Mansfield NJ, Arrowsmith CI, et al., 2012, The influence of seat backrest angle on perceived discomfort during exposure to vertical whole-body vibration, ERGONOMICS, Vol: 55, Pages: 923-936, ISSN: 0014-0139
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- Citations: 24
DiFiore AM, Zaouk AK, Mansfield NJ, et al., 2012, WHOLE-BODY VIBRATION IN LOCOMOTIVE CABS, ASME Rail Transportation Division Fall Conference, Publisher: AMER SOC MECHANICAL ENGINEERS, Pages: 87-+
Paddan GS, Holmes SR, Mansfield NJ, et al., 2012, The influence of seat backrest angle on human performance during whole-body vibration, ERGONOMICS, Vol: 55, Pages: 114-128, ISSN: 0014-0139
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- Citations: 13
Maeda S, Mansfield NJ, 2011, Multiplier of axis of whole-body multi-axis vibration, Pages: 3628-3635
The purpose of this research is to explore and validate the effect of direction with regard to whole-body vibration using the category judgment method. Experiments were conducted using random signals as stimuli. The stimuli consisted of vibration with flat PSD (Power Spectrum Density) ranging from 1 to 20 Hz. The signal levels were varied over a range of 3 steps (0.2, 0.4, and 0.8 m/s 2 r.m.s. of unweighted acceleration magnitude) of each x, y, and z-axis to create 9 kinds of individual stimuli. The subjects sat on a flat, horizontal metal plate mounted directly on the vibrator and were exposed to x, y, and z axis vibrations before being asked to choose a numerical category to best indicate their perceived level of comfort (or otherwise) during each stimulus. It was shown that subject' assessment of the degree of comfort perceived does not differ with differences in the vibration direction, when the unweighted acceleration magnitude was used. But, it was clear that the current multiplier of ISO 2631-1 can't use to evaluate the subjective response, when the weighted acceleration magnitude according to the ISO 2631-1 standard. The best agreement was achieved when axis scaling factors were set at 2.2 and 2.4 for x- and y-axis vibration respectively.
Marjanen Y, Mansfield NJ, 2011, Application of ISO 2631-1 (1997) for evaluating discomfort from whole-body vibration: Verification using field and laboratory studies, Pages: 3475-3480
Exposure to vibration is an intrinsic part of our lives. Practically all types of transportation will cause vibration to a human body. In some cases the vibration causes health effects, but in most cases it causes discomfort, which manifests as distraction, annoyance and other problems. Because increasing numbers of people use transportation, it is important to understand and minimize the effects of vibration. ISO 2631-1 (1997) provides a method to evaluate discomfort from multi-axis whole-body vibration, but it has been lacking published studies and guidance on its usability. The standard method leaves many options and possibilities for the user, without providing any reference on how different interpretations affect the results. This paper presents findings and suggestions on using the standard method in laboratory and field environments for predicting discomfort from whole-body vibration. The study is based on an extensive literature research and new laboratory and field experiments with over 40 subjects. The findings suggest that the current standard method can predict discomfort with adequate correlation (Spearman r 2 > 0.5). It was found that using as many axes as possible and r.m.s. averaging produced the best correlation. The correlation could be further improved if the multiplying factors are calculated for each environment. However, there are also limitations to be considered: 1) results from different environments cannot be compared with each other, 2) evaluation can be done only for the relative change between measurements and 3) the relative effect of the axes change depending on the environment, thus correlation level will vary.
Mansfield NJ, Maeda S, 2011, Subjective ratings of whole-body vibration for single- and multi-axis motion, JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, Vol: 130, Pages: 3723-3728, ISSN: 0001-4966
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- Citations: 14
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