Navigating large-scale virtual environments: what differences occur between helmet-mounted and desk-top displays?

Participants used a helmet-mounted display (HMD) and a desk-top (monitor) display to learn the layouts of two large-scale virtual environments (VEs) through repeated, direct navigational experience. Both VEs were ‘‘virtual buildings’’ containing more than seventy rooms. Participants using the HMD navigated the buildings significantly more quickly and developed a significantly more accurate sense of relative straight-line distance. There was no significant difference between the two types of display in terms of the distance that participants traveled or the mean accuracy of their direction estimates. Behavioral analyses showed that participants took advantage of the natural, head-tracked interface provided by the HMD in ways that included ‘‘looking around’’more often while traveling through the VEs, and spending less time stationary in the VEs while choosing a direction in which to travel

Navigating large-scale ‘‘desk-top’’ virtual buildings: effects of orientation aids and familiarity

Two experiments investigated components of participants’ spatial knowledge when they navigated large-scale ‘‘virtual buildings’’ using ‘‘desk-top’’ (i.e., nonimmersive) virtual environments (VEs). Experiment 1 showed that participants could estimate directions with reasonable accuracy when they traveled along paths that contained one or two turns (changes of direction), but participants’ estimates were significantly less accurate when the paths contained three turns. In Experiment 2 participants repeatedly navigated two more complex virtual buildings, one with and the other without a compass. The accuracy of participants’ route-finding and their direction and relative straight-line distance estimates improved with experience, but there were no significant differences between the two compass conditions. However, participants did develop significantly more accurate spatial knowledge as they became more familiar with navigating VEs in general

Clinical outcomes from The BodyMind Approach™ in the treatment of patients with medically unexplained symptoms in primary health care in England: practice-based evidence

This is the accepted manuscript version of the following article: Helen Payne and Susan D. M. Brooks, ‘Clinical outcomes from The BodyMind Approach™ in the treatment of patients with medically unexplained symptoms in primary health care in England: Practice-based evidence’, The Arts in Psychotherapy, Vol 47: 55-65, February 2016, doi: http://dx.doi.org/10.1016/j.aip.2015.12.001. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/.This article builds on Payne (2015) and reports on practice–based evidence arising out of the delivery of a new and innovative service using The BodyMind Approach™ (TBMA) for the treatment of patients with medically unexplained symptoms (MUS) in primary care in the National Health Service (NHS) in Hertfordshire, a county near London, England, in the UK. The analysis of data collected for three groups (N=16) over 18 months used standardised assessment tools and other relevant information at pre, post and at a six month follow up. The outcomes for patients in this small scale piece of practice based evidence indicated that there were reductions in symptom distress, anxiety and depression, increased overall wellbeing and improvement in activity levels. Patients developed self-management of their symptoms through understanding, acceptance and coping strategies. The increased knowledge, exchange of experiences together with understanding and acceptance from others promoted a sense of wellbeing. Thus, the programme was experienced to be a beneficial intervention. In addition to the clinical outcomes reported here there are other benefits for NHS England for example, savings on medication and referral costs and General Practitioner (GP) capacity enhanced. The clinical service is based on previous research conducted by Payne and Stott (2010). This article focusses solely on the analysis and interpretation of clinical outcomes from the practice-based evidence. Keywords: The BodyMind Approach™; medically unexplained symptoms; primary care; practice-based evidence IntroductionPeer reviewedFinal Accepted Versio

Autonomous and context-aware scheduling for public displays using place-based tag clouds

Public displays are an increasingly ubiquitous element of our socio-digital landscape with a strong potential to become key building blocks for AmI. For that purpose, they should have the ability to dynamically and autonomously select content from web sources according to the relevance of their content to the Continuous flow of social settings around the display. In this paper, we explore the creation of a public display system that evaluates the relevance of content from web sources and selects the most relevant content according to a dynamic tag cloud that incorporates static place definitions, but is also sensitive to the people around the display. We have developed and evaluate a dynamic content selection system based on those principles.. The results show that place visitors recognize the sensitivity of the system to their demands and that a place tag cloud can provide an important element for the interpretation of place and for the combination of the interests expressed by the place owner and the multiple place visitors.The first author was supported by a Portuguese Foundation for Science and Technology scholarship (SFRH/BD/31292/2006)

Modified conjugated gradient method for diagonalising large matrices

We present an iterative method to diagonalise large matrices. The basic idea is the same as the conjugated gradient (CG) method, i.e, minimizing the Rayleigh quotient via its gradient and avoiding reintroduce errors to the directions of previous gradients. Each iteration step is to find lowest eigenvector of the matrix in a subspace spanned by the current trial vector and the corresponding gradient of the Rayleigh quotient, as well as some previous trial vectors. The gradient, together with the previous trail vectors, play a similar role of the conjugated gradient of the original CG algorithm. Our numeric tests indicate that this method converges significantly faster than the original CG method. And the computational cost of one iteration step is about the same as the original CG method. It is suitably for first principle calculations.Comment: 6 Pages, 2EPS figures. (To appear in Phys. Rev. E

A new peat bog testate amoeba transfer function and quantitative palaeohydrological reconstructions from southern Patagonia

Testate amoebae have been extensively used as proxies for environmental change and palaeoclimate reconstructions in European and North American peatlands. The presence of these micro-organisms near the peat surface is generally significantly linked to the local water table depth (WTD) and therefore preservation of the amoeba shells downcore allows for water table reconstructions over millennia. In the last decades, attention for the palaeoecology of the southern Patagonian peat bogs has increased, partly because of the particular climatological setting under the influence of the southern westerlies. These atypical peat bogs are characterised by a wide range of water tables, from wet hollows to hummocks exceeding 100 cm above the water table, and a dominance of Sphagnum magellanicum on low lawns up to the highest hummocks. Here we present the first transfer function for this region that allows for reliable WTD reconstructions, along with 2k-year palaeorecords from local peat bogs.A modern dataset (155 samples) was sampled along transects from five bogs in 2012 and 2013. Measurements of WTD, pH and conductivity were taken for all samples. Transfer function model was based on the 2012 dataset while the 2013 samples served as an independent test set to validate the model. Besides the standard leave-one- out cross-validation we applied leave-one-site-out and leave-one transect-out cross-validation, which are effective means of verifying the degree of clustering in the dataset. To assure the environmental gradient had been evenly sampled we quantified the root-mean-squared error of prediction (RMSEP) individually for segments of this gradient.Ordinations showed a clear hydrological gradient in amoeba assemblages, with the dominant Assulina muscorum at the dry end and Amphitrema wrightianum and Difflugia globulosa at the wet end. Taxa as Nebela certesi and Nebela cockayni, possibly exclusive to the southern hemisphere, were identified and their optima and tolerances were determined. Canonical correspondence analysis showed that WTD was the most important environmental variable, accounting for 18% of the variance in amoeba assemblages. A weighted averaging-partial least squares model showed best performance in cross-validation and using the 2013 data as an independent test set. Any spatial autocorrelation was minimal although the model still appeared less effective in predicting WTD for sites not included in the training set. The segment-wise RMSEP showed that the WTD gradient was generally evenly sampled with RMSEP below 15 cm for most of the gradient, much lower than the standard deviation of the mean of all WTDs (26 cm).Preliminary results from peat cores sampled from the same peat bogs show surprisingly stable water tables over the last 2k years in Andorra bog but more variation in nearby Tierra Australis bog. Peat accumulation rates in Andorra bog are among the highest recorded in temperate bogs with around 4 m of peat accumulated during the last 2000 year

One-way multigrid method in electronic structure calculations

We propose a simple and efficient one-way multigrid method for self-consistent electronic structure calculations based on iterative diagonalization. Total energy calculations are performed on several different levels of grids starting from the coarsest grid, with wave functions transferred to each finer level. The only changes compared to a single grid calculation are interpolation and orthonormalization steps outside the original total energy calculation and required only for transferring between grids. This feature results in a minimal amount of code change, and enables us to employ a sophisticated interpolation method and noninteger ratio of grid spacings. Calculations employing a preconditioned conjugate gradient method are presented for two examples, a quantum dot and a charged molecular system. Use of three grid levels with grid spacings 2h, 1.5h, and h decreases the computer time by about a factor of 5 compared to single level calculations.Comment: 10 pages, 2 figures, to appear in Phys. Rev. B, Rapid Communication