645 research outputs found

    Fast and precise touch-based text entry for head-mounted augmented reality with variable occlusion

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    We present the VISAR keyboard: An augmented reality (AR) head-mounted display (HMD) system that supports text entry via a virtualised input surface. Users select keys on the virtual keyboard by imitating the process of single-hand typing on a physical touchscreen display. Our system uses a statistical decoder to infer users’ intended text and to provide error-tolerant predictions. There is also a high-precision fall-back mechanism to support users in indicating which keys should be unmodified by the auto-correction process. A unique advantage of leveraging the well-established touch input paradigm is that our system enables text entry with minimal visual clutter on the see-through display, thus preserving the user’s field-of-view. We iteratively designed and evaluated our system and show that the final iteration of the system supports a mean entry rate of 17.75wpm with a mean character error rate less than 1%. This performance represents a 19.6% improvement relative to the state-of-the-art baseline investigated: A gaze-then-gesture text entry technique derived from the system keyboard on the Microsoft HoloLens. Finally, we validate that the system is effective in supporting text entry in a fully mobile usage scenario likely to be encountered in industrial applications of AR HMDs.Per Ola Kristensson was supported in part by a Google Faculty research award and EPSRC grants EP/N010558/1 and EP/N014278/1. Keith Vertanen was supported in part by a Google Faculty research award. John Dudley was supported by the Trimble Fund

    Velocitap: Investigating fast mobile text entry using sentence-based decoding of touchscreen keyboard input

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    We present VelociTap: a state-of-the-art touchscreen keyboard decoder that supports a sentence-based text entry approach. VelociTap enables users to seamlessly choose from three word-delimiter actions: pushing a space key, swiping to the right, or simply omitting the space key and letting the decoder infer spaces automatically. We demonstrate that VelociTap has a significantly lower error rate than Google’s keyboard while retaining the same entry rate. We show that intermediate visual feedback does not significantly affect entry or error rates and we find that using the space key results in the most accurate results. We also demonstrate that enabling flexible word-delimiter options does not incur an error rate penalty. Finally, we investigate how small we can make the keyboard when using VelociTap. We show that novice users can reach a mean entry rate of 41 wpm on a 40mm wide smartwatch-sized keyboard at a 3% character error rate.This is the accepted manuscript. The final version is available from ACM at http://dl.acm.org/citation.cfm?id=2702135

    Rates of cholesterol, ubiquinone, dolichol and dolichyl-P biosynthesis in rat brain slices

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    AbstractSlices from the brain and liver of rats were prepared and upon incubation exhibited a continuous and high capacity for incorporation of radioactive precursors into proteins and lipids. Using [3H]mevalonate as precursor, the rates of biosynthesis of cholesterol, ubiquinone, dolichol and dolichyl-P in brain slices were determined and found to be 5.5,0.25,0.0093 and 0.0091 nmol/h/g, respectively. Dolichol and dolichyl-P accumulate to a limited extent, but almost all of these lipids in the brain originate from de novo synthesis. The calculated half-lives for cholesterol, ubiquinone, dolichol and dolichyl-P were 4076, 90, 1006 and 171 h, respectively. The results indicate that lipids formed via the mevalonate pathway in the brain have an active and independently regulated biosynthesis

    How do people type on mobile devices? Observations from a study with 37,000 volunteers

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    © 2019 Association for Computing Machinery. This paper presents a large-scale dataset on mobile text entry collected via a web-based transcription task performed by 37,370 volunteers. The average typing speed was 36.2 WPM with 2.3% uncorrected errors. The scale of the data enables powerful statistical analyses on the correlation between typing performance and various factors, such as demographics, finger usage, and use of intelligent text entry techniques. We report effects of age and finger usage on performance that correspond to previous studies. We also find evidence of relationships between performance and use of intelligent text entry techniques: auto-correct usage correlates positively with entry rates, whereas word prediction usage has a negative correlation. To aid further work on modeling, machine learning and design improvements in mobile text entry, we make the code and dataset openly available

    VelociWatch: Designing and evaluating a virtual keyboard for the input of challenging text

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    © 2019 Association for Computing Machinery. Virtual keyboard typing is typically aided by an auto-correct method that decodes a user’s noisy taps into their intended text. This decoding process can reduce error rates and possibly increase entry rates by allowing users to type faster but less precisely. However, virtual keyboard decoders sometimes make mistakes that change a user’s desired word into another. This is particularly problematic for challenging text such as proper names. We investigate whether users can guess words that are likely to cause auto-correct problems and whether users can adjust their behavior to assist the decoder. We conduct computational experiments to decide what predictions to ofer in a virtual keyboard and design a smartwatch keyboard named VelociWatch. Novice users were able to use the features of VelociWatch to enter challenging text at 17 words-per-minute with a corrected error rate of 3%. Interestingly, they wrote slightly faster and just as accurately on a simpler keyboard with limited correction options. Our fnding suggest users may be able to type dif-fcult words on a smartwatch simply by tapping precisely without the use of auto-correct

    First-time fathers experiences of their prenatal preparation in relation to challenges met in the early parenthood period : Implications for early parenthood preparation

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    Objective to describe first-time fathers experiences of their prenatal preparation in relation to challenges met in the early parenthood period. Design a qualitative study was conducted and data was analysed with a phenomenographical approach. Setting and participants 15 first-time fathers were recruited from three postnatal units in southern Sweden and interviewed approximately one month after their baby was born. Measurements and findings three categories and 14 conceptions about fathers' experiences of their preparation emerged from the data. ‘Acquiring knowledge and forming realistic expectations' was essential for ‘Developing strategies' and ‘Being facilitated and supported' enhanced these processes. Key conclusions and implications for practice supporting fathers to develop strategies for life with a new baby and providing expert guidance to fruitful and accurate information may help the construction of a fatherhood identity and strengthen the fatherhood role. The findings can be used to develop a parental preparation for early parenthood that will correspond to fathers' needs

    On the acoustic diffraction by the edges of benthic shells

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    Author Posting. © Acoustical Society of America, 2004. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 116 (2004): 239-244, doi:10.1121/1.1675813.Recent laboratory measurements of acoustic backscattering by individual benthic shells have isolated the edge-diffracted echo from echoes due to the surface of the main body of the shell. The data indicate that the echo near broadside incidence is generally the strongest for all orientations and is due principally to the surface of the main body. At angles well away from broadside, the echo levels are lower and are due primarily to the diffraction from the edge of the shell. The decrease in echo levels from broadside incidence to well off broadside is shown to be reasonably consistent with the decrease in acoustic backscattering from normal incidence to well off normal incidence by a shell-covered seafloor. The results suggest the importance of the edge of the shell in off-normal-incidence backscattering by a shell-covered seafloor. Furthermore, when considering bistatic diffraction by edges, there are implications that the edge of the shell (lying on the seafloor) can cause significant scattering in many directions, including at subcritical angles.This research was supported by the U.S. Office of Naval Research (Grant No. N00014-02-1-0095) and the Woods Hole Oceanographic Institution (WHOI), Woods Hole, MA

    Fast and flexible selection with a single switch

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    Selection methods that require only a single-switch input, such as a button click or blink, are potentially useful for individuals with motor impairments, mobile technology users, and individuals wishing to transmit information securely. We present a single-switch selection method, "Nomon," that is general and efficient. Existing single-switch selection methods require selectable options to be arranged in ways that limit potential applications. By contrast, traditional operating systems, web browsers, and free-form applications (such as drawing) place options at arbitrary points on the screen. Nomon, however, has the flexibility to select any point on a screen. Nomon adapts automatically to an individual's clicking ability; it allows a person who clicks precisely to make a selection quickly and allows a person who clicks imprecisely more time to make a selection without error. Nomon reaps gains in information rate by allowing the specification of beliefs (priors) about option selection probabilities and by avoiding tree-based selection schemes in favor of direct (posterior) inference. We have developed both a Nomon-based writing application and a drawing application. To evaluate Nomon's performance, we compared the writing application with a popular existing method for single-switch writing (row-column scanning). Novice users wrote 35% faster with the Nomon interface than with the scanning interface. An experienced user (author TB, with > 10 hours practice) wrote at speeds of 9.3 words per minute with Nomon, using 1.2 clicks per character and making no errors in the final text.Comment: 14 pages, 5 figures, 1 table, presented at NIPS 2009 Mini-symposi
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