3,397 research outputs found
A Dose of Reality: Overcoming Usability Challenges in VR Head-Mounted Displays
We identify usability challenges facing consumers adopting Virtual Reality (VR) head-mounted displays (HMDs) in a survey of 108 VR HMD users. Users reported significant issues in interacting with, and being aware of their real-world context when using a HMD. Building upon existing work on blending real and virtual environments, we performed three design studies to address these usability concerns. In a typing study, we show that augmenting VR with a view of reality significantly corrected the performance impairment of
typing in VR. We then investigated how much reality should be incorporated and when, so as to preserve users’ sense of presence in VR. For interaction with objects and peripherals, we found that selectively presenting reality as users engaged with it was optimal in terms of performance and users’ sense of presence. Finally, we investigated how this selective, engagement-dependent approach could be applied in social environments, to support the user’s awareness of the proximity and presence of others
Comprehensive simulations of superhumps
(Abridged) We use 3D SPH calculations with higher resolution, as well as with
more realistic viscosity and sound-speed prescriptions than previous work to
examine the eccentric instability which underlies the superhump phenomenon in
semi-detached binaries. We illustrate the importance of the two-armed spiral
mode in the generation of superhumps. Differential motions in the fluid disc
cause converging flows which lead to strong spiral shocks once each superhump
cycle. The dissipation associated with these shocks powers the superhump. We
compare 2D and 3D results, and conclude that 3D simulations are necessary to
faithfully simulate the disc dynamics. We ran our simulations for unprecedented
durations, so that an eccentric equilibrium is established except at high mass
ratios where the growth rate of the instability is very low. Our improved
simulations give a closer match to the observed relationship between superhump
period excess and binary mass ratio than previous numerical work. The observed
black hole X-ray transient superhumpers appear to have systematically lower
disc precession rates than the cataclysmic variables. This could be due to
higher disc temperatures and thicknesses. The modulation in total viscous
dissipation on the superhump period is overwhelmingly from the region of the
disc within the 3:1 resonance radius. As the eccentric instability develops,
the viscous torques are enhanced, and the disc consequently adjusts to a new
equilibrium state, as suggested in the thermal-tidal instability model. We
quantify this enhancement in the viscosity, which is ~10 per cent for q=0.08.
We characterise the eccentricity distributions in our accretion discs, and show
that the entire body of the disc partakes in the eccentricity.Comment: 18 pages (mn2e LaTeX), 14 figures, 5 tables, Accepted for publication
in MNRA
Rub the stane
Stane is a hand-held interaction device controlled by
tactile input: scratching or rubbing textured surfaces
and tapping. The system has a range of sensors,
including contact microphones, capacitive sensing and
inertial sensing, and provides audio and vibrotactile
feedback. The surface textures vary around the device,
providing perceivably different textures to the user. We
demonstrate that the vibration signals generated by
stroking and scratching these surfaces can be reliably
classified, and can be used as a very cheap to
manufacture way to control different aspects of
interaction. The system is demonstrated as a control for
a music player, and in a mobile spatial interaction
scenario
Poems
The right life
I am my beloveds and my beloved is mine
Angles of repose
This morning
Migration
In a sea fog
Penguins
For comrades in solitary confinement
Greater flamingoes
snipe
Oystercatcher
One sooty falcon
Lesser kestrel
Two ravens
The nest in tatters
That pair of pigeons
Over a cup of tea
And gathering of swallows twitter
The speech of birds
Early morning May
Bird brigade
Recommended from our members
New methods for digital modeling of historic sites
We discuss new methods for building 3D models of historic sites. Our algorithm automatically computes pairwise registrations between individual scans, builds a topological graph, and places the scans in the same frame of reference
28 frames later: predicting screen touches from back-of-device grip changes
We demonstrate that front-of-screen targeting on mobile
phones can be predicted from back-of-device grip manipulations. Using simple, low-resolution capacitive touch sensors placed around a standard phone, we outline a machine learning approach to modelling the grip modulation and inferring front-of-screen touch targets. We experimentally demonstrate that grip is a remarkably good predictor of touch, and we can predict touch position 200ms before contact with an accuracy of 18mm
Recommended from our members
Circulating microRNAs as biomarkers to assist the management of the malignant germ-cell-tumour subtype choriocarcinoma.
Germ-cell-tumours (GCTs) are heterogeneous and management is complex. The current conventional biomarkers, alpha-fetoprotein and human-chorionic-gonadotropin (HCG), have limited utility for diagnosis/follow-up as secretion is restricted to specific malignant-GCT subtypes and long half-life can make interpretation and clinical decision-making challenging. We sought to identify circulating microRNAs that reflected choriocarcinoma disease activity more accurately than HCG in a metastatic primary mediastinal nonseminomatous-GCT (PMNSGCT) case with elevated diagnostic serum HCG (>250,000U/L), consistent with pure choriocarcinoma. We undertook comprehensive microRNA profiling (n=754 microRNAs) using two 384-well TaqMan Low-Density-Array cards in 16 serum samples; 10 from PMNSGCT diagnosis/follow-up and six controls. Key findings underwent confirmatory qRT-PCR. We identified a serum panel of choriocarcinoma-specific ‘chromosome-19-microRNA-cluster’ (C19MC) microRNAs that were highly elevated at diagnosis but fell rapidly on treatment and normalised before the second full chemotherapy course. We also re-confirmed serum elevation of the previously identified malignant-GCT marker miR-371a-3p at diagnosis. These circulating microRNA markers reflected choriocarcinoma disease activity more accurately than serum HCG and real-time knowledge would have assisted clinical decision-making. With further study, these microRNA markers will facilitate future management of such patients and are likely to result in improved outcomes.Acknowledgment of research support: The authors acknowledge grant funding from the St. Baldrick’s Foundation [reference 358099], the Isaac Newton Trust [reference 15.40f], the Medical Research Council [reference MR/R001146/1] and Addenbrooke’s Charitable Trust [reference 23/17 B (iv)]. We are grateful for support from the Max Williamson Fund and from Christiane and Alan Hodson, in memory of their daughter Olivia. The funders were not involved in study design, data collection or interpretation, or decision to submit for publication
Eccentricity Growth Rates of Tidally Distorted Discs
We consider discs that orbit a central object and are tidally perturbed by a
circular orbit companion. Such discs are sometimes subject to an eccentric
instability due to the effects of certain resonances. Eccentric instabilities
may be present in planetary rings perturbed by satellites, protostellar discs
perturbed by planets, and discs in binary star systems. Although the basic
mechanism for eccentric instability is well understood, the detailed response
of a gaseous disc to such an instability is not understood. We apply a linear
eccentricity evolution equation developed by Goodchild and Ogilvie. We explore
how the eccentricity is distributed in such a disc and how the distribution in
turn affects the instability growth rate for a range of disc properties. We
identify a disc mode, termed the superhump mode, that is likely at work in the
superhump binary star case. The mode results from the excitation of the
fundamental free precession mode. We determine an analytic expression for the
fundamental free mode precession rate that is applicable to a sufficiently cool
disc. Depending on the disc sound speed and disc edge location, other eccentric
modes can grow faster than the superhump mode and dominate.Comment: 11 pages, 15 figures to be published on MNRA
- …