Phenomenal regression to the real object in physical and virtual worlds

© 2014, Springer-Verlag London. In this paper, we investigate a new approach to comparing physical and virtual size and depth percepts that captures the involuntary responses of participants to different stimuli in their field of view, rather than relying on their skill at judging size, reaching or directed walking. We show, via an effect first observed in the 1930s, that participants asked to equate the perspective projections of disc objects at different distances make a systematic error that is both individual in its extent and comparable in the particular physical and virtual setting we have tested. Prior work has shown that this systematic error is difficult to correct, even when participants are knowledgeable of its likelihood of occurring. In fact, in the real world, the error only reduces as the available cues to depth are artificially reduced. This makes the effect we describe a potentially powerful, intrinsic measure of VE quality that ultimately may contribute to our understanding of VE depth compression phenomena

Automatic visualization and control of arbitrary numerical simulations

Authors’ preprint version as submitted to ECCOMAS Congress 2016, Minisymposium 505 - Interactive Simulations in Computational Engineering. Abstract: Visualization of numerical simulation data has become a cornerstone for many industries and research areas today. There exists a large amount of software support, which is usually tied to specific problem domains or simulation platforms. However, numerical simulations have commonalities in the building blocks of their descriptions (e. g., dimensionality, range constraints, sample frequency). Instead of encoding these descriptions and their meaning into software architecures we propose to base their interpretation and evaluation on a data-centric model. This approach draws much inspiration from work of the IEEE Simulation Interoperability Standards Group as currently applied in distributed (military) training and simulation scenarios and seeks to extend those ideas. By using an extensible self-describing protocol format, simulation users as well as simulation-code providers would be able to express the meaning of their data even if no access to the underlying source code was available or if new and unforseen use cases emerge. A protocol definition will allow simulation-domain experts to describe constraints that can be used for automatically creating appropriate visualizations of simulation data and control interfaces. Potentially, this will enable leveraging innovations on both the simulation and visualization side of the problem continuum. We envision the design and development of algorithms and software tools for the automatic visualization of complex data from numerical simulations executed on a wide variety of platforms (e. g., remote HPC systems, local many-core or GPU-based systems). We also envisage using this automatically gathered information to control (or steer) the simulation while it is running, as well as providing the ability for fine-tuning representational aspects of the visualizations produced

Automatic visualization and control of arbitrary numerical simulations

Authors’ preprint version as submitted to ECCOMAS Congress 2016, Minisymposium 505 - Interactive Simulations in Computational Engineering. Abstract: Visualization of numerical simulation data has become a cornerstone for many industries and research areas today. There exists a large amount of software support, which is usually tied to specific problem domains or simulation platforms. However, numerical simulations have commonalities in the building blocks of their descriptions (e. g., dimensionality, range constraints, sample frequency). Instead of encoding these descriptions and their meaning into software architecures we propose to base their interpretation and evaluation on a data-centric model. This approach draws much inspiration from work of the IEEE Simulation Interoperability Standards Group as currently applied in distributed (military) training and simulation scenarios and seeks to extend those ideas. By using an extensible self-describing protocol format, simulation users as well as simulation-code providers would be able to express the meaning of their data even if no access to the underlying source code was available or if new and unforseen use cases emerge. A protocol definition will allow simulation-domain experts to describe constraints that can be used for automatically creating appropriate visualizations of simulation data and control interfaces. Potentially, this will enable leveraging innovations on both the simulation and visualization side of the problem continuum. We envision the design and development of algorithms and software tools for the automatic visualization of complex data from numerical simulations executed on a wide variety of platforms (e. g., remote HPC systems, local many-core or GPU-based systems). We also envisage using this automatically gathered information to control (or steer) the simulation while it is running, as well as providing the ability for fine-tuning representational aspects of the visualizations produced

'Now I care': a qualitative study of how overweight adolescents managed their weight in the transition to adulthood

Objectives: A qualitative study of recalled experiences of early adolescent overweight/obesity revealed low levels of weight-related concern. This further analysis aimed to explore weight-related concern and weight-loss efforts as participants transitioned into adulthood. Design, participants and methods: Participants were 35 young adults from a population-based cohort study who had body mass index (BMI) >95th centile between ages 11 and 15 and participated in semistructured interviews aged 24. At age 24, they were categorised as: ‘slimmers’ (N=13) who had lower BMI Z-scores at 24 than their adolescent peak and were not obese (BMI<30 kg/m2); ‘relapsers’ (N=8, of whom 2 were morbidly obese (BMI>35 kg/m2) at age 24); ‘stable’ (N=3, of whom 1 morbidly obese); and ‘gainers’ (N=11, of whom 5 morbidly obese). Themes were identified and coded using NVivo qualitative data analysis software, blind to participants’ current weight status. Results: Contrasting with the lack of concern recalled in respect of earlier adolescence, weight-related concerns and/or desire to lose weight generally increased around the time of school leaving and almost all participants described some form of exercise (formal/informal) and dietary weight-control strategies. Among ‘slimmers’, there was some (subtle) evidence of more consistent use of exercise, self-monitoring of diet and exercise and of lifestyle changes becoming habitual and/or part of identity. Few participants had accessed professional support. Diet clubs seemed to have been used most by ‘gainers’, some only recently. Labour-market and housing transitions were strong influences, described as facilitating weight losses by some, but increases by others. For some participants, it appeared that weight loss was simply a by-product of these transitions. Conclusions: In contrast to earlier adolescence, even the heaviest participants tended to show actual weight loss action or preparation for action. The transition to adulthood could thus be a key life stage for interventions

Simplifying collaboration in co-located virtual environments using the active-passive approach

The design and implementation of co-located immersive virtual environments with equal interaction possibilities for all participants is a complex topic. The main problem, on a fundamental technical level, is the difficulty of providing perspective-correct images for each participant. There is consensus that the lack of a correct perspective view will negatively affect interaction fidelity and therefore also collaboration. Several research approaches focus on providing a correct perspective view to all participants to enable co-located work. However, these approaches are usually either based on custom hardware solutions that limit the number of users with a correct perspective view or software solutions striving to eliminate or mitigate restrictions with custom image-generation approaches. In this paper we investigate an often overlooked approach to enable collaboration for multiple users in an immersive virtual environment designed for a single user. The approach provides one (active) user with a perspective-correct view while other (passive) users receive visual cues that are not perspective-correct. We used this active-passive approach to investigate the limitations posed by assigning the viewpoint to only one user. The findings of our study, though inconclusive, revealed two curiosities. First, our results suggest that the location of target geometry is an important factor to consider for designing interaction, expanding on prior work that has studied only the relation between user positions. Secondly, there seems to be only a low cost involved in accepting the limitation of providing perspective-correct images to a single user, when comparing with a baseline, during a coordinated work approach. These findings advance our understanding of collaboration in co-located virtual environments and suggest an approach to simplify co-located collaboration

A study of experience in selected hospital services in a three year nursing school.

Includes 9 figures and 20 tables. Thesis (M.S.)--Boston University Please note: there's a discrepancy between the thesis itself, which claims 1955 as the submission date, and the library records, which claim 1957

Detection and classification of the sounds produced by artificial human hip implants

Total hip replacement has become a common procedure in the treatment of hip disorders. In doing so, the bony components of the hip are replaced with artificial inserts. Regular follow-up is required for all joint replacements to anticipate complications. However, in recent times sounds emanating from the implants have been identified and there is an interest in their causes and implications. It is the latter of these concerns that is the focus of this document. Sounds were recorded from the hip implants of participants while they performed a number of specified movements. This was achieved using an electronic stethoscope. Spectrograms were used to identify individual sounds in the complete recordings. In order to filter out the background noise from the recordings, a 5th order Savitzky-Golay filter with a window width of 21 points was implemented. The effectiveness of this filter was confirmed by cross-correlating the original and filtered signals to ensure preservation of low frequencies. The discrete wavelet transformation was used in order to distinguish between the different sounds. The symlet8 wavelet was used and the signals were decomposed into 10 detail levels. Using this method, 3 different sound classes were identified based on the different wavelet levels. These classes were further characterised by determining the skewness and kurtosis of the Welch power spectra. Upon listening to the sounds, it was found that the three classes also appeared audibly different. A sound detection and classification procedure, based on the wavelet characteristics and the classes defined, was developed and tested. It allowed individual hip implant sounds to be characterised in previously unseen and unanalysed recordings. These sounds were analysed and classified into one of the 3 main sound classes. A number of patient and implant factors were also considered in trying to identify whether any condition might predispose an individual implant to produce sounds. These include body mass index (BMI), implant age, implant angle, movement performed and bearing surface combination. The ceramic-on-metal implants, and implants in participants with overweight BMI scores produced the most sounds. Despite this, no consistent links between these factors and the sounds produced could be identified. The occurrences of the 3 different sounds classes within the different patient factor groups was also investigated. This was done to determine whether or not the pattern of occurrence could be used to determine which of the patient factor groups an unknown recording belonged to. This, by extension, might reveal some information about the implant producing the sounds. However, the occurrence patterns were so similar in many patient factor groups studied that this technique was considered unfeasible. One exception was the different bearing surface combinations, each of which exhibited a different occurrence pattern. Therefore, the occurrence of certain wavelet characteristics may be used to suggest which of the bearing surface combinations a hip implant contains. Another exception was the overweight BMI group, which had a distinct sound class occurrence pattern, and therefore wavelet characteristic pattern, from the underweight and obese BMI groups. This research supports aspects of previous work done on the topic, and introduces a new methodology to acquire hip implant sound data. In addition, new classes of implant sounds are defined. Discrete wavelet decomposition was shown to be an effective signal analysis tool for this problem. Much work remains to be done on hip implant sounds and these findings add to the growing collection of knowledge on the subject

Dramatics in the church school

This item was digitized by the Internet Archive. Thesis (M.A)--Boston Universityhttps://archive.org/details/dramaticsinchurc00wri