Framework of Reliability-Based Stochastic Mobility Map for Next Generation NATO Reference Mobility Model

2019 ◽  
Vol 14 (2) ◽  
Author(s):  
K. K. Choi ◽  
Paramsothy Jayakumar ◽  
Matthew Funk ◽  
Nicholas Gaul ◽  
Tamer M. Wasfy
Keyword(s):  
Normal Distribution ◽  
Soil Property ◽  
Region Of Interest ◽  
Mobility Model ◽  
Maximum Speed ◽  
Next Generation ◽  
Input Parameters ◽  
Terrain Elevation ◽  
Dynamic Kriging ◽  
Geotechnical Databases

A framework for generation of reliability-based stochastic off-road mobility maps is developed to support the next generation NATO reference mobility model (NG-NRMM) using full stochastic knowledge of terrain properties and modern complex terramechanics modeling and simulation capabilities. The framework is for carrying out uncertainty quantification (UQ) and reliability assessment for Speed Made Good and GO/NOGO decisions for the ground vehicle based on the input variability models of the terrain elevation and soil property parameters. To generate the distribution of the slope at given point, realizations of the elevation raster are generated using the normal distribution. For the soil property parameters, such as cohesion, friction, and bulk density, the min and max values obtained from geotechnical databases for each of the soil types are used to generate the normal distribution with a 99% confidence value range. In the framework, the ranges of terramechanics input parameters that will cover the regions of interest are first identified. Within these ranges of input parameters, a dynamic kriging (DKG) surrogate model is obtained for the maximum speed of the nevada automotive test center (NATC) wheeled vehicle platform complex terramechanics model. Finally, inverse reliability analysis using Monte Carlo simulation is carried out to generate the reliability-based stochastic mobility maps for Speed Made Good and GO/NOGO decisions. It is found that the deterministic map of the region of interest has probability of only 25% to achieve the indicated speed.

The Next Generation NATO Reference mobility model development

2017 ◽  
Vol 73 ◽  
pp. 49-60 ◽  
Author(s):  
Michael McCullough ◽  
Paramsothy Jayakumar ◽  
Jean Dasch ◽  
David Gorsich
Keyword(s):  
Model Development ◽  
Mobility Model ◽  
Next Generation

scholarly journals Mobility models for next generation wireless mesh network

2021 ◽  
Vol 22 (1) ◽  
pp. 379
Author(s):  
Tsehay Admassu Assegie ◽  
Tamilarasi Suresh ◽  
R. Subhashni ◽  
Deepika M
Keyword(s):  
Wireless Network ◽  
Wireless Mesh Network ◽  
Local Area Network ◽  
Mobility Model ◽  
Mesh Network ◽  
Area Network ◽  
Mobility Models ◽  
Next Generation ◽  
Test Bed ◽  
Wireless Mesh

<span>Wireless mesh network (WMN) is a new trend in wireless communication promising greater flexibility, reliability, and performance over traditional wireless local area network (WLAN). Test bed analysis and emulation plays an essential role in valuation of software defined wireless network and node mobility is the prominent feature of next generation software defined wireless network. In this study, the mobility models employed for moving mobile stations in software defined wireless network are explored. Moreover, the importance of mobility model within software defined wireless mesh network for enhancing the performance through handover-based load balancing is analyzed. The mobility models for the next generation software defined wireless network are explored. Furthermore, we have presented the mobility models in the mininet-Wi-Fi test bed, and evaluated the performance of Gauss Marko’s mobility model.</span>

scholarly journals Evaluation of reliability index and probability of failure for the improvement of the Nigerian empirical mechanistic flexible pavement analysis and design system (Nempads)

2021 ◽  
Vol 40 (4) ◽  
pp. 564-575
Author(s):  
M.M. Musa ◽  
A.T. Olowosulu ◽  
A.A. Murana ◽  
J.M. Kaura ◽  
I. Bello ◽  
...  
Keyword(s):  
Normal Distribution ◽  
Material Properties ◽  
Reliability Index ◽  
Flexible Pavement ◽  
Probability Of Failure ◽  
Pavement Design ◽  
Design System ◽  
Component Reliability ◽  
Input Parameters ◽  
Different Seasons

The aim of this work was to evaluate reliability index (RI) with respect to fatigue and rutting within the different seasons peculiar to Nigeria, in order to improve Empirical-Mechanistic flexible pavement design approach, using First Order Reliability Method (FORM). Flexible pavement design involves many uncertainties, variabilities, and approximations regarding the input parameters like material properties, traffic loads. Others include subgrade strength, drainage conditions, construction, compaction procedures and climatic factors such as temperature, rainfall, and snowfall, etc. The combination of the variances associated with input parameters contributes to components and system uncertainty, and this combination of variances can have a significant effect on the predicted performance of the pavement. Reliability in pavement design is introduced to consider these uncertainties. Layers thicknesses, material properties, and Equivalent Standard Axle Load (ESAL) were entered into a multi-layer elastic theory software, ELSYM-5, which in turn were used to calculate strains and stresses for different seasons. The results obtained were entered into Nigerian fitted transfer function distress models to compute allowable ESALS. Miner’s hypothesis theory equation was used to calculate the cumulative damage due to stress and strains generated. A Framework was generated for finding individual reliability index (RI), systemic reliability index (SRI), and probability of failure. The findings showed that Season I (Winter) recorded the highest component reliability index for fatigue (5.63 for Normal Distribution). Season II (Summer) recorded the lowest component reliability index (β) for rutting (5.4 for Normal Distribution). Season III (Spring) recorded the lowest component reliability index for fatigue (1.85 for Normal Distribution)

New Developments in High-Resolution X-ray Computed Tomography for Non-Destructive Defect Detection in Next Generation Package Technologies

2008 ◽  
Author(s):  
Mario Pacheco ◽  
Deepak Goyal
Keyword(s):  
Computed Tomography ◽  
High Resolution ◽  
Region Of Interest ◽  
Alternative Methods ◽  
Next Generation ◽  
New Developments ◽  
X Ray ◽  
Ct Technology ◽  
X Ray Computed ◽  
Non Destructive

Abstract The development of a next generation high-resolution x-ray Computed Tomography (CT) tool and its applications are reported in this paper. Some of the key features are region of interest capability, improved time-to-data, improved usability, and data collection automation capability. We also discuss the key technical challenges that are faced by x-ray CT technology. Critical cases that are hard or not possible to isolate by alternative methods are also discussed. Examples include Controlled Collapse Chip Connection (C4) bump cracking and “invisible” non-wetting analysis, ball grid array (BGA) solder joint cracking, and wirebond microcracking and wirebond shorting, as well as demonstration of progressive testing capability.

Detection of viruses by electron microscopy: Increased sensitivity by direct micro-ultracentrifugation of samples

1987 ◽  
Vol 45 ◽  
pp. 908-909
Author(s):  
Alain R. Trudel ◽  
M. Trudel
Keyword(s):  
Electron Microscopy ◽  
Fold Increase ◽  
Observation Time ◽  
Clinical Samples ◽  
Maximum Speed ◽  
Viral Particles ◽  
Structural Details ◽  
Latex Spheres ◽  
Increased Sensitivity ◽  
Size Of Particles

AirfugeR (Beckman) direct ultracentrifugation of viral samples on electron microscopy grids offers a rapid way to concentrate viral particles or subunits and facilitate their detection and study. Using the A-100 fixed angle rotor (30°) with a K factor of 19 at maximum speed (95 000 rpm), samples up to 240 μl can be prepared for electron microscopy observation in a few minutes: observation time is decreased and structural details are highlighted. Using latex spheres to calculate the increase in sensitivity compared to the inverted drop procedure, we obtained a 10 to 40 fold increase in sensitivity depending on the size of particles. This technique also permits quantification of viral particles in samples if an aliquot is mixed with latex spheres of known concentration.Direct ultracentrifugation for electron microscopy can be performed on laboratory samples such as gradient or column fractions, infected cell supernatant, or on clinical samples such as urine, tears, cephalo-rachidian liquid, etc..

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