Immersive 3D visualization laboratory concept
In the paper an advanced concept for a Virtual Reality (VR) CAVE installation is presented, which should allow for human immersion in a spatially unlimited virtual world. The CAVE will be completed by the end of 2013 in a special building designed and constructed for the purpose. The unit will simulate an autonomous movement of a human inside a computer generated scenery. The person immersed in VR space will be placed in a transparent sphere with a large diameter supported on rollers and equipped with a motion tracking system. Walking motion of the person will inflict the revolution of the ball and trigger changes in the computer generated images on screens surrounding the sphere thus creating an illusion of motion. The projection system will be equipped with a 3D simulation capability and supplemented with a spatial sound generation system.
Sphere Drive and Control System for Haptic Interaction With Physical, Virtual, and Augmented Reality
A system for haptic interaction with physical, virtual, and augmented realities, founded on drive and measurement elements (DMEs), is considered. The system consists of eight DME rolls equipped with linear actuators, able to measure their angular velocity, drive the sphere, and adjust downforce (pressing the roll against the sphere). Two modeling issues are addressed. Special effort is put in to compensate for various technical issues. Analytic derivation of the relation between the angular velocities of the rolls and the sphere is presented. On this basis, the importance of control over the downforce applied to an individual roll is indicated with the aim of minimizing the wear of the roll. The selection of the proper downforce for each specific position (angle) of a DME roll can extend its life cycle by reducing its grinding on the sphere. The issue of modeling the relation between the angular velocity of a given DME and the sphere is addressed. In a simplified case, such a relation can be obtained analytically. However, for a nonuniform distribution of reaction forces on the contact area, a numerical approach is necessary. Two numerical methods for the estimation of the angular velocity of the DME roll are presented and discussed. Moreover, an algorithm for the estimation of the sphere’s rotational motion parameters is described and implemented, proving the usefulness of the presented method.
Test security in medicolegal cases: proposed guidelines for attorneys utilizing neuropsychology practice.
In the context of forensic neuropsychological assessments, the professional interaction of law and psychology is viewed primarily as one where the retaining attorney or court dictates its needs to psychologists when resolving legal disputes. While this perspective is conceptually accurate, the positive and practical collaboration of law and psychology also relies on attorneys adhering to basic protections of sensitive psychological assessment procedures and tests. Objective testing is undermined when a practitioner of law engages in actions prior to, during, or following a neuropsychological examination in a manner that threatens the test security. An appreciation among practitioners of law and psychology regarding the necessity of test security is essential. This article reviews attorney actions that can affect test security, proposes a distinction by psychology between appropriate and problematic client preparation for a neuropsychological examination, integrates the available legal precedent regarding test security, and suggests productive measures to protect test security in medicolegal settings.