Search results for "Computer simulation"
showing 10 items of 1054 documents
Validating rationale of group-level component analysis based on estimating number of sources in EEG through model order selection
2012
This study addresses how to validate the rationale of group component analysis (CA) for blind source separation through estimating the number of sources in each individual EEG dataset via model order selection. Control children, typically reading children with risk for reading disability (RD), and children with RD participated in the experiment. Passive oddball paradigm was used for eliciting mismatch negativity during EEG data collection. Data were cleaned by two digital filters with pass bands of 1-30 Hz and 1-15 Hz and a wavelet filter with the pass band narrower than 1-12 Hz. Three model order selection methods were used to estimate the number of sources in each filtered EEG dataset. Un…
The VEPSY UPDATED Project: Clinical Rationale and Technical Approach.
2003
More than 10 years ago, Tart (1990) described virtual reality (VR) as a technological model of consciousness offering intriguing possibilities for developing diagnostic, inductive, psychotherapeutic, and training techniques that can extend and supplement current ones. To exploit and understand this potential is the overall goal of the "Telemedicine and Portable Virtual Environment in Clinical Psychology"--VEPSY UPDATED--a European Community-funded research project (IST-2000-25323, www.cybertherapy.info). Particularly, its specific goal is the development of different PC-based virtual reality modules to be used in clinical assessment and treatment of social phobia, panic disorders, male sexu…
Intercepting real and simulated falling objects: what is the difference?
2009
International audience; The use of virtual reality is nowadays common in many studies in the field of human perception and movement control, particularly in interceptive actions. However, the ecological validity of the simulation is often taken for granted without having been formally established. If participants were to perceive the real situation and its virtual equivalent in a different fashion, the generalization of the results obtained in virtual reality to real life would be highly questionable. We tested the ecological validity of virtual reality in this context by comparing the timing of interceptive actions based upon actually falling objects and their simulated counterparts. The r…
Improving spatial functioning in children with cerebral palsy using computerized and traditional game tasks.
2003
To examine the effectiveness of combining virtual environment (VE) instruction with additional desk-top tasks, based on the Luria-Vygotsky methodology, for spatial remediation in children having complex motor disabilities restricting movement.In Experiment 1, from among children attending for residential rehabilitation, an experimental subgroup had additional spatial training using a VE and corresponding desk-top models. All children were tested at the start and end of training, using four spatial tests. In Experiment 2, larger groups of children (pair-matched for initial performance) were given the same training as in Experiment 1, but experimentals received both VE-based training and supp…
Cardiac kinematic parameters computed from video of in situ beating heart
2017
AbstractMechanical function of the heart during open-chest cardiac surgery is exclusively monitored by echocardiographic techniques. However, little is known about local kinematics, particularly for the reperfused regions after ischemic events. We report a novel imaging modality, which extracts local and global kinematic parameters from videos of in situ beating hearts, displaying live video cardiograms of the contraction events. A custom algorithm tracked the movement of a video marker positioned ad hoc onto a selected area and analyzed, during the entire recording, the contraction trajectory, displacement, velocity, acceleration, kinetic energy and force. Moreover, global epicardial veloc…
Impact of perceptual ability and mental imagery training on simulated laparoscopic knot-tying in surgical novices using a Nissen fundoplication model.
2011
Background: Performing minimally invasive surgery requires training and visual-spatial intelligence. The aim of our study was to examine the impact of visual-spatial perception and additional mental training on the simulated laparoscopic knot-tying task performed by surgical novices. Methods: A total of 40 medical students randomly assigned to two groups underwent two sessions of laparoscopic basic training on a VR simulator (SimSurgery®, Oslo, Norway). The variables time and tip trajectory (total path length of the instrument tip trajectory) were used to assess the performance of the intracorporeal knot-tying task using a laparoscopic Nissen fundoplication model. The experimental group com…
Haemodynamic predictors of a penetrating atherosclerotic ulcer rupture using fluid-structure interaction analysis
2013
We present preliminary data on the flow-induced haemodynamic and structural loads exerted on a penetrating atherosclerotic aortic ulcer (PAU). Specifically, one-way fluid-structure interaction analysis was performed on the aortic model reconstructed from a 66-year-old male patient with a PAU that evolved into an intramural haematoma and rupture of the thoracic aorta. The results show that elevated blood pressure (117 mmHg) and low flow velocity at the aortic wall (0.15 m/s(2)) occurred in the region of the PAU. We also found a low value of time-averaged wall shear stress (1.24 N/m(2)) and a high value of the temporal oscillation in the wall shear stress (oscillatory shear index = 0.13) in t…
Computational modeling in cognitive science: a manifesto for change.
2012
Computational modeling has long been one of the traditional pillars of cognitive science. Unfortunately, the computer models of cognition being developed today have not kept up with the enormous changes that have taken place in computer technology and, especially, in human-computer interfaces. For all intents and purposes, modeling is still done today as it was 25, or even 35, years ago. Everyone still programs in his or her own favorite programming language, source code is rarely made available, accessibility of models to non-programming researchers is essentially non-existent, and even for other modelers, the profusion of source code in a multitude of programming languages, written witho…
Numerical study for a new methodology of flaws detection in train axles
2013
Train loads and travel speeds have increased over time, requiring more efficient non-destructive inspection methods. Railway axles are critical elements; despite being designed to last more than 20 years several cases of premature failure have been recorded. Train axles are inspected regularly, but the limits associated to the traditional inspection technologies create a growing interest towards new solutions. Here a novel non-destructive inspection method of in-service axles based on non-contact data collection is presented. The propagation of surface waves, generated by a thermo-elastic laser source, is investigated using a finite element method based on dynamic explicit integration. Coup…
Experimental and theoretical studies of Stark profiles of Ar I 696.5 nm spectral line in laser-induced plasma
2019
Abstract We report the results of the Stark profile studies of the 696.543 nm Ar I spectral line in laser-induced plasma generated by a nanosecond Nd:YAG laser radiation at 532 nm in argon at reduced pressure. Plasma diagnostics was performed with the use of the laser Thomson scattering method, free from assumptions about the plasma thermodynamic equilibrium, its composition but also independently of plasma emission spectra. The profiles were investigated in wide range of electron densities and temperatures, from 2.81 · 1022 m − 3 to 5.69 · 1023 m − 3 and from 10 430 K to 73 400 K, respectively. Stark profiles were calculated using a semi-classical method as well as by N-body numerical simu…