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  • ItemOpen Access
    Perceptions and experiences of Lime scooters: Summary survey results
    (2019) Fitt, Helen; Curl, Angela
    In February and March 2019 we invited people, whether they had used an e-scooter or not, to tell us what they thought about e-scooter use in New Zealand. At that point, Lime e-scooters were available in four areas of New Zealand: Auckland, Hutt Valley, Christchurch, and Dunedin. Prior to the arrival of Lime, e-scooters had not been widely available, but around the end of 2018 and the beginning of 2019 Lime e scooters arrived, and e-scooters became prominent in practice and in conversation, were regularly featured in media stories, and became increasingly available for personal purchase. Our first survey aimed to capture early data about the use and perceptions of e-scooters and we intend subsequent surveys to explore how the situation evolves over time. A survey of attitudes to and use of e-scooters in New Zealand cities received 591 useable responses from a convenience sample, distributed through interest groups and social media. - Respondents to the survey were more likely to be young adults, NZ European, to have a high level of education, and a high income; most were from Christchurch. - Although not representative of the population, the survey provides some insights into e-scooter use. - 71% of respondents had used an e-scooter, 29% had not. - 25% of e-scooter users had used an e-scooter once, 75% had used e-scooters more than once. - Younger people, men, and those in full-time employment were most likely to use e-scooters. -First time e-scooter users were most motivated by wanting to have fun and try e-scootering. - Subsequent e-scooter use was increasingly motivated by practical considerations around the speed and convenience of e-scooters as a means of transport. - Respondents who had used an e-scooter more than once commonly reported using an e-scooter to travel to work, social engagements, or to shops or supermarkets. - Most people who had not used an e-scooter had not wanted or needed to use one. - Concerns about safety, expense, and not being able to wear normal clothes while e-scootering topped the list of practical reasons for not using an e-scooter. - For those who had used an e-scooter more than once: - 57% of e-scooter trips replaced trips that would otherwise have been made by active or sustainable modes (on foot, by bicycle, skateboard, or e-bike). - 28% of e-scooter trips replaced a trip by private car or van, motorcycle, ride source vehicle, or taxi. - 7% of e-scooter trips were new trips that would not otherwise have been made. - Over 90% of e-scooter users had ridden on the footpath, only around half (51%) of users and far fewer (26%) non-users think that the footpath is an appropriate environment to ride an e-scooter. - These results can help to generate better understandings of e-scooter use and can support the development of transport systems with benefits for New Zealand.
  • ItemOpen Access
    Reducing beam hardening effects and metal artefacts in spectral CT using Medipix3RX
    (2013-11-21) Rajendran, K; Walsh, M. F.; de Ruiter, N. J. A.; Chernoglazov, A. I.; Panta, R. K.; Butler, P. H.; Bell, S. T.; Woodfield, T. B. F.; Tredinnick, J.; Healy, J. L.; Bateman, C. J.; Aamir, R.; Doesburg, R. M. N.; Renaud, P. F.; Gieseg, S. P.; Smithies, D. J.; Mohr, J. L.; Mandalika, V. B. H.; Opie, A. M. T.; Cook, N. J.; Ronaldson, J. P.; Nik, S. J.; Atharifard, A.; Clyne, M.; Bones, P. J.; Bartneck, Christoph; Grasset, R.; Schleich, N.; Billinghurst, Mark; Butler, A. P. H.; Anderson, N. G.
    Studies on beam hardening and metal artefact reduction using Medipix All Resolution System (MARS) spectral scanner were carried out. Four datasets are provided - titanium phantom, titanium scaffold, magnesium scaffold and titanium mesh. Each of these datasets are organized as raw data, preprocessed and MARS-ART reconstruction. The 'RAW DATA' directory contains dicom files representing darkfield images, open beam images and raw projection images. The 'PREPROCESSED' directory contains darkfield corrected, normalized and ring-filtered projection images in tif format. The 'MARS-ART RECONSTRUCTION' directory contains full volume reconstruction in tif format for all the energy bins using algebraic reconstruction technique. Projections are taken for every camera position during the spectral scans and MARS-ART software directly operates on unstitched projections. The geometrical information for every projection image can be accessed from the dicom tags associated with each dicom file.
  • ItemOpen Access
    Reducing beam hardening effects and metal artefacts in spectral CT using Medipix3RX
    (2014-02-05) Rajendran, K; Walsh, M. F.; de Ruiter, N. J. A.; Chernoglazov, A. I.; Panta, R. K.; Butler, P. H.; Bell, S. T.; Woodfield, T. B. F.; Tredinnick, J.; Healy, J. L.; Bateman, C. J.; Aamir, R.; Doesburg, R. M. N.; Renaud, P. F.; Gieseg, S. P.; Smithies, D. J.; Mohr, J. L.; Mandalika, V. B. H.; Opie, A. M. T.; Cook, N. J.; Ronaldson, J. P.; Nik, S. J.; Atharifard, A.; Clyne, M.; Bones, P. J.; Bartneck, Christoph; Grasset, R.; Schleich, N.; Billinghurst, Mark; Butler, A. P. H.; Anderson, N. G.
    This paper discusses methods for reducing beam hardening effects and metal artefacts using spectral x-ray information in biomaterial samples. A small-animal spectral scanner was operated in the 15 to 80 keV x-ray energy range for this study. We use the photon-processing features of a CdTe-Medipix3RX ASIC in charge summing mode to reduce beam hardening and associated artefacts. We present spectral data collected for metal alloy samples, its analysis using algebraic 3D reconstruction software and volume visualisation using a custom volume rendering software. The cupping effect and streak artefacts were quantified in the spectral datasets. The results show reduction in beam hardening effects and metal artefacts in the narrow high energy range acquired using the spectroscopic detector. A post-reconstruction comparison between CdTe-Medipix3RX and Si-Medipix3.1 is discussed. The raw data and processed data are openly available for testing with other software routines.
  • ItemOpen Access
    MARS spectral molecular imaging of lamb tissue: data collection and image analysis
    (2013-10-31) Aamir, R.; Chernoglazov, A.; Bateman, C. J.; Butler, A.P.H.; Butler, P.H.; Anderson, N.G.; Bell, S.T.; Panta, R.; Healy, J.L.; Mohr, J.L.; Rajendran, K.; Walsh, M.F.; de Ruiter, J.A.; Giesig, S.P.; Woodfield, T.; Renaud, P.F.; Brooke, L.V.; Majid, S.A.; Clyne, R.; Glendinning, R.; Bones, P.J.; Billinghurst, Mark; Bartneck, Christoph; Mandalika, H.; Grasset, R.; Schleich, N.; Scott, N.; Nik, S. J.; Opie, A.; Janmale, T.; Tang, D.N.; Kim, D.; Doesburg, R.M.; Zainon, R.; Ronaldson, J.P.; Cook, N.J.; Smithies, D.; Hodge, K.
    In this experiment, a meat specimen was prepared from a fresh lamb chop, which included muscle (water-like), fat (lipid-like) and bone (calcium-like) regions, and scanned. We used a 2 mm thick CdTe sensor (128×128), bump bonded at 110 µm to Medipix3RX readout chip and installed in the MARS-CT4 scanner. In charge summing mode (CSM), 720 circular projections over 360° were acquired using a Source-Ray SB-80-1K x-ray tube (Source-Ray Inc, Ronkonkoma, NY) with a tungsten anode having 1.8-mm-Al equivalent intrinsic filtration. Several vertical positions of the CdTe Medipix3RX camera were used to create a virtual detector to cover the 23 mm field of view (FOV). The source to detector distance (SDD) was 131.8mm and object to detector distance (ODD) was 48mm. Camera readout was performed using the MARS readout system. Before the measurements, threshold equalization with respect to the noise edge, and energy calibration of the detector, were performed. Flat-field measurements (500 flat-fields per energy bin) were taken before specimen scanning to correct for variations in pixel response. Dark-field images (50 dark-fields per energy bin) were also acquired before and after the scan. The tube was operated at 50 kVp with a current of 120 μA and using four low energy thresholds (15, 20, 25, 30 keV). The exposure time of each acquisition was 40 ms. For data analysis and HU calibration, a phantom having CaCl2 (320 mg/ml) and lipid (vegetable oil), along with air and water, was also scanned with the same parameters mentioned earlier. The raw data in DICOM format from the scanner was processed using the MARS Image Processing Suite. More detail can be found from the relevant paper data paper.