Dynamic Collision Detection Using Space Partitioning

1993 ◽  
Vol 115 (1) ◽  
pp. 150-155 ◽  
Author(s):  
M. A. Ganter ◽  
B. P. Isarankura
Keyword(s):  
Computer Simulation ◽  
Collision Detection ◽  
Computation Time ◽  
Local Region ◽  
Detection Time ◽  
Space Partitioning ◽  
Simulated Environment ◽  
Time Required ◽  
Six Degree Of Freedom ◽  
Partitioning Technique

A technique termed space partitioning is employed which dramatically reduces the computation time required to detect dynamic collision during computer simulation. The simulated environment is composed of two nonconvex polyhedra traversing two general six-degree-of-freedom trajectories. This space partitioning technique reduces collision detection time by subdividing the space containing a given object into a set of partitions. Using these partitions, all testing can be confined to the local region of overlap between the two objects. Further, all entities contained in the partitions inside the region of overlap are ordered based on their respective minimums and maximums to further reduce testing.

Dynamic Collision Detection Using Space Partitioning

1990 ◽  
Author(s):  
M. A. Ganter ◽  
B. P. Isarankura
Keyword(s):  
Collision Detection ◽  
Computation Time ◽  
Local Region ◽  
Detection Time ◽  
Space Partitioning ◽  
Worst Case ◽  
Simulated Environment ◽  
Time Required ◽  
Six Degree Of Freedom ◽  
Partitioning Technique

Abstract A technique termed space partitioning is employed which dramatically reduces the computation time required to detect dynamic collision during computer simulation. The simulated environment is composed of two nonconvex polyhedra traversing two general six degree of freedom trajectories. This space partitioning technique reduces collision detection time by subdividing the space containing a given object into a set of linear partitions. Using these partitions, all testing can be confined to the local region of overlap between the two objects. Further, all entities contained in the partitions inside the region of overlap are ordered based on their respective minimums and maximums to further reduce testing. Experimental results indicate a worst-case collision detection time for two one thousand faced objects is approximately three seconds per trajectory step.

An Octree Algorithm for Dynamic Interference Detection Using Space Partitioning

1996 ◽  
Author(s):  
Yongxiang Yu ◽  
Minghua Wu ◽  
Ji Zhou
Keyword(s):  
Collision Detection ◽  
Computation Time ◽  
Interference Detection ◽  
Space Partitioning ◽  
Time Consumption ◽  
Dynamic Interference ◽  
Partitioning Technique

Abstract This paper presents an octree algorithm for collision and interference detection using space partitioning technique. The technique greatly reduces the computation time consumed in dynamic collision detection during simulation progress. The simulated objects are represented in hierarchically decomposed octrees. Under this technique, the checking space can be partitioned according to the geometric dependence of two octrees, so that the relations (overlap or separate) among the nodes in the octrees can be determined directly. Since heuristic calculation is excluded from the algorithm, the time consumption for collision detection is greatly reduced.

Robotic Assembly Cell Simulation

1992 ◽  
Author(s):  
Jian Liu ◽  
J. P. Sadler
Keyword(s):  
Computer Simulation ◽  
Computer Modeling ◽  
Collision Detection ◽  
Robotic Assembly ◽  
Research Activities ◽  
Assembly Cell ◽  
Cell Simulation ◽  
Manufacturing Environments

Abstract A flexible robotic assembly cell is described, and some of the research activities involving the cell and robot applications in manufacturing environments are presented. This research relies heavily on computer simulation. Assembly cell computer modeling, cell calibration, robot collision detection, and off-line programming are described in this paper.

scholarly journals Data (Video) Encryption in Mobile devices

2017 ◽  
Vol 2 (3) ◽  
pp. 32-39
Author(s):  
Aya Khalid Naji ◽  
Saad Najim Alsaad
Keyword(s):  
Elliptic Curve ◽  
Mobile Devices ◽  
Mobile Device ◽  
Elliptic Curve Cryptography ◽  
Computation Time ◽  
Video Encryption ◽  
Android Platform ◽  
Time Required ◽  
New Generation

In the development of 3G devices, all elements of multimedia (text, image, audio, and video) are becoming crucial choice for communication. The secured system in 3G devices has become an issue of importance, on which lot of research is going on. The traditional cryptosystem like DES, AES, and RSA do not able to meet with the properties of the new generation of digital mobile devices. This paper presents an implementation of video protection of fully encrypted using Elliptic Curve   Cryptography (ECC) on a mobile device. The Android platform is used for this purpose.  The results refer that the two important criteria of video mobile encryption: the short computation time required and high confidentially are provided.

An Adaptive Multiscaling Approach for Reducing Computation Time in Simulations of Articulated Biopolymers

2019 ◽  
Vol 14 (5) ◽  
Author(s):  
Ashley Guy ◽  
Alan Bowling
Keyword(s):  
Computational Cost ◽  
Time History ◽  
Computation Time ◽  
Coarse Graining ◽  
Integration Time ◽  
Dynamic Simulations ◽  
Equivalent Time ◽  
Time Histories ◽  
Time Required ◽  
Computational Resources

Microscale dynamic simulations can require significant computational resources to generate desired time evolutions. Microscale phenomena are often driven by even smaller scale dynamics, requiring multiscale system definitions to combine these effects. At the smallest scale, large active forces lead to large resultant accelerations, requiring small integration time steps to fully capture the motion and dictating the integration time for the entire model. Multiscale modeling techniques aim to reduce this computational cost, often by separating the system into subsystems or coarse graining to simplify calculations. A multiscale method has been previously shown to greatly reduce the time required to simulate systems in the continuum regime while generating equivalent time histories. This method identifies a portion of the active and dissipative forces that cancel and contribute little to the overall motion. The forces are then scaled to eliminate these noncontributing portions. This work extends that method to include an adaptive scaling method for forces that have large changes in magnitude across the time history. Results show that the adaptive formulation generates time histories similar to those of the unscaled truth model. Computation time reduction is consistent with the existing method.

A simplified approach for thermal elastohydrodynamic lubrication analysis of circular contacts using realistic lubricant properties

2018 ◽  
Vol 232 (12) ◽  
pp. 1618-1632
Author(s):  
Puneet Katyal ◽  
Punit Kumar
Keyword(s):  
Mathematical Models ◽  
Point Contact ◽  
Elastohydrodynamic Lubrication ◽  
Computation Time ◽  
Fluid Temperature ◽  
Simplified Approach ◽  
Lubrication Film ◽  
Isothermal Case ◽  
Lubrication Characteristics ◽  
Time Required

Thermal effect in elastohydrodynamic lubrication has been the subject of extensive research for several decades. The focus of this study was primarily on the development of an efficient numerical scheme to deal with the computational challenges involved in the solution of thermal elastohydrodynamic lubrication model; however, some important aspects related to the accurate description of lubricant properties such as viscosity, rheology, and thermal conductivity in elastohydrodynamic lubrication point contact analysis remain largely neglected. A few studies available in this regard are based upon highly complex mathematical models difficult to formulate and execute. The end-users may not have the specialized skill, knowledge, and time required for the development of computational codes pertaining to these models. Therefore, this paper offers a very simple approach to determine the distribution of mean fluid temperature within an elastohydrodynamic lubrication film. While it is an approximate method, it yields reasonably accurate results with only a little increase in computation time with respect to the isothermal case. Moreover, it can be added as a small module to any existing isothermal algorithm. Using this simplified thermal elastohydrodynamic lubrication model for point contacts, this work sheds some light on the importance of accurate characterization of the lubricant properties and demonstrates that the computed thermal elastohydrodynamic lubrication characteristics are highly sensitive to lubricant properties. It also emphasizes the use of appropriate mathematical models with experimentally determined parameters to account for the correct lubricant behavior.

Optimal Size Fuzzy Models

2007 ◽  
Vol 11 (3) ◽  
pp. 335-341 ◽  
Author(s):  
Tamás D. Gedeon ◽  
◽  
László T. Kóczy ◽  
Alessandro Zorat ◽  
◽  
...  
Keyword(s):  
Target Location ◽  
Fuzzy Rule ◽  
Computation Time ◽  
Rule Base ◽  
Optimal Size ◽  
Moving Target ◽  
Trade Off ◽  
Base Size ◽  
Target Localisation ◽  
Time Required

Approximate models using fuzzy rule bases can be made more precise by suitably increasing the size of the rule base and decreasing uncertainty in the rules. A large rule base, however, requires more time for its evaluation and hence the problem arises of determining the size that is good enough for the task at hand, but allows as fast as possible reasoning using the rule base. This trade-off between computation time and precision is significant whenever a prediction is made which can become “out of date” or “too old” if not used in time. The trade off is considered here in the context of tracking a moving target. In this problem, a higher degree of accuracy results in tighter precision of determining target location, but at the cost of longer computation time, during which the target can move further away, thus ultimately requiring a longer search for exact target localisation. This paper examines the problem of determining the optimal rule base size that will yield a minimum total time required to repeatedly re-acquire the moving target, as done by a cat that plays with a mouse. While this problem has no known solution in its general formulation, solutions are shown here for specific contexts.

scholarly journals 3D Rigid Registration of Intraoperative Ultrasound and Preoperative MR Brain Images Based on Hyperechogenic Structures

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Pierrick Coupé ◽  
Pierre Hellier ◽  
Xavier Morandi ◽  
Christian Barillot
Keyword(s):  
Intraoperative Ultrasound ◽  
Joint Probability ◽  
Computation Time ◽  
Visual Assessment ◽  
Neurosurgical Procedures ◽  
Registration Accuracy ◽  
Brain Images ◽  
Study Results ◽  
The Difference ◽  
Time Required

The registration of intraoperative ultrasound (US) images with preoperative magnetic resonance (MR) images is a challenging problem due to the difference of information contained in each image modality. To overcome this difficulty, we introduce a new probabilistic function based on the matching of cerebral hyperechogenic structures. In brain imaging, these structures are the liquid interfaces such as the cerebral falx and the sulci, and the lesions when the corresponding tissue is hyperechogenic. The registration procedure is achieved by maximizing the joint probability for a voxel to be included in hyperechogenic structures in both modalities. Experiments were carried out on real datasets acquired during neurosurgical procedures. The proposed validation framework is based on (i) visual assessment, (ii) manual expert estimations , and (iii) a robustness study. Results show that the proposed method (i) is visually efficient, (ii) produces no statistically different registration accuracy compared to manual-based expert registration, and (iii) converges robustly. Finally, the computation time required by our method is compatible with intraoperative use.

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