Dynamical issues at the low level of human / virtual object interaction

2006 ◽  
Author(s):  
J. Florens ◽  
D. Urma
Keyword(s):  
Virtual Object ◽  
Low Level ◽  
Object Interaction

scholarly journals Brain Process for Perception of the “Out of the Body” Tactile Illusion for Virtual Object Interaction

Sensors ◽  
2015 ◽  
Vol 15 (4) ◽  
pp. 7913-7932 ◽  
Author(s):  
Hye Lee ◽  
Jaedong Lee ◽  
Chi Kim ◽  
Gerard Kim ◽  
Eun-Soo Kim ◽  
...  
Keyword(s):  
The Body ◽  
Virtual Object ◽  
Brain Process ◽  
Object Interaction ◽  
Tactile Illusion

scholarly journals Action Generation Adapted to Low-Level and High-Level Robot-Object Interaction States

2019 ◽  
Vol 13 ◽  
Author(s):  
Carlos Maestre ◽  
Ghanim Mukhtar ◽  
Christophe Gonzales ◽  
Stephane Doncieux
Keyword(s):  
Low Level ◽  
Object Interaction ◽  
High Level

scholarly journals Levels of Control During a Collaborative Carrying Task

2003 ◽  
Vol 12 (2) ◽  
pp. 140-155 ◽  
Author(s):  
Roy A. Ruddle ◽  
Justin C. D. Savage ◽  
Dylan M. Jones
Keyword(s):  
Motor Control ◽  
Virtual Environment ◽  
Obstacle Avoidance ◽  
Virtual Object ◽  
Virtual Human ◽  
Cognitive Resources ◽  
Body Movements ◽  
Low Level ◽  
Immersive Virtual Environment ◽  
Levels Of Control

Three experiments investigated the effect of implementing low-level aspects of motor control for a collaborative carrying task within a VE interface, leaving participants free to devote their cognitive resources to the higher-level components of the task. In the task, participants collaborated with an autonomous virtual human in an immersive virtual environment (VE) to carry an object along a predefined path. In experiment 1, participants took up to three times longer to perform the task with a conventional VE interface, in which they had to explicitly coordinate their hand and body movements, than with an interface that controlled the low-level tasks of grasping and holding onto the virtual object. Experiments 2 and 3 extended the study to include the task of carrying an object along a path that contained obstacles to movement. By allowing participants' virtual arms to stretch slightly, the interface software was able to take over some aspects of obstacle avoidance (another low-level task), and this led to further significant reductions in the time that participants took to perform the carrying task. Improvements in performance also occurred when participants used a tethered viewpoint to control their movements because they could see their immediate surroundings in the VEs. This latter finding demonstrates the superiority of a tethered view perspective to a conventional, human'seye perspective for this type of task.

Comparing Kinematic and Dynamic Hand Models for Interactive Grasping Simulation

2009 ◽  
Author(s):  
Zolta´n Rusa´k ◽  
Csaba Antonya ◽  
Imre Horva´th ◽  
Doru Talaba
Keyword(s):  
Virtual Object ◽  
Control Mechanisms ◽  
Joint Torques ◽  
Object Interaction ◽  
Virtual Hand ◽  
Hand Model ◽  
Desktop Virtual Reality ◽  
Grasping Forces ◽  
Product Interaction ◽  
Real Hand

This paper compares two approaches to controlling virtual hands in grasping simulation, and it investigates the ability of humans to control with their hands a virtual hand model in manipulative tasks. In our setup, the users are following their interaction in a desktop virtual reality environment, in order to determine the feasibility of user studies for user – virtual product interaction. Because no real force feed-back is provided, the user can decide upon the correctness of the grasping posture only from visual feedback. The hand and the virtual object interaction are computed from a simulation, therefore accurate spatial position of the real hand and fingers are needed to be measured in real time. Our simulation program is using the Nvidia PhysX SDK. We have implemented two control mechanisms, which enables the users of the system to manipulate the virtual hand. The first mechanism controls the motion of the virtual hand and grasping forces based on the principles of kinematics and energy transfer by contact simulation. The second mechanism relies on the principles of multibody dynamics, controlling the motion of the hand by PD controllers, and applying joint torques to the hand in order to exert forces on the grasped object. In this paper, we compare how well these principles perform in (a) accurately moving the virtual hand in the simulation space, (b) accurately positioning the fingers on the grasped objects, and (c) controlling the grasping forces on the objects.

The Theoretical Contrast in Scanning and Conventional High Resolution Microscopes

1969 ◽  
Vol 27 ◽  
pp. 170-171
Author(s):  
E. Zeitler ◽  
M. G. R. Thomson
Keyword(s):  
Small Volume ◽  
Volume Element ◽  
Optical Processing ◽  
Image Construction ◽  
Object Interaction ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Optical Treatment ◽  
Electron Microscopes ◽  
Intensity Contrast

In the formation of an image each small volume element of the object is correlated to an areal element in the image. The structure or detail of the object is represented by changes in intensity from element to element, and this variation of intensity (contrast) is determined by the interaction of the electrons with the specimen, and by the optical processing of the information-carrying electrons. Both conventional and scanning transmission electron microscopes form images which may be considered in this way, but the mechanism of image construction is very different in the two cases. Although the electron-object interaction is the same, the optical treatment differs.

Tryptophan-Niacin Metabolism in Rat with Puromycin Aminonucleoside-Induced Nephrosis

2006 ◽  
Vol 76 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Yukari Egashira ◽  
Shin Nagaki ◽  
Hiroo Sanada
Keyword(s):  
Body Weight ◽  
Urinary Excretion ◽  
Enzyme Activities ◽  
Treated Group ◽  
Control Group ◽  
Puromycin Aminonucleoside ◽  
Low Level ◽  
Key Enzyme

We investigated the change of tryptophan-niacin metabolism in rats with puromycin aminonucleoside PAN-induced nephrosis, the mechanisms responsible for their change of urinary excretion of nicotinamide and its metabolites, and the role of the kidney in tryptophan-niacin conversion. PAN-treated rats were intraperitoneally injected once with a 1.0% (w/v) solution of PAN at a dose of 100 mg/kg body weight. The collection of 24-hour urine was conducted 8 days after PAN injection. Daily urinary excretion of nicotinamide and its metabolites, liver and blood NAD, and key enzyme activities of tryptophan-niacin metabolism were determined. In PAN-treated rats, the sum of urinary excretion of nicotinamide and its metabolites was significantly lower compared with controls. The kidneyα-amino-β-carboxymuconate-ε-semialdehyde decarboxylase (ACMSD) activity in the PAN-treated group was significantly decreased by 50%, compared with the control group. Although kidney ACMSD activity was reduced, the conversion of tryptophan to niacin tended to be lower in the PAN-treated rats. A decrease in urinary excretion of niacin and the conversion of tryptophan to niacin in nephrotic rats may contribute to a low level of blood tryptophan. The role of kidney ACMSD activity may be minimal concerning tryptophan-niacin conversion under this experimental condition.

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