A high-speed implementation of manifold coordinate representations of hyperspectral imagery: a GPU-based approach to rapid nonlinear modeling

2010 ◽  
Author(s):  
T. Russell Topping ◽  
James French ◽  
Monte F. Hancock, Jr.
Keyword(s):  
High Speed ◽  
Hyperspectral Imagery ◽  
Nonlinear Modeling

A Finite-Element Model of Blood Flow in Arteries Including Taper, Branches, and Obstructions

1986 ◽  
Vol 108 (2) ◽  
pp. 161-167 ◽  
Author(s):  
G. Porenta ◽  
D. F. Young ◽  
T. R. Rogge
Keyword(s):  
Finite Element ◽  
Blood Flow ◽  
High Speed ◽  
Nonlinear Modeling ◽  
Element Model ◽  
Arterial Blood Flow ◽  
Algebraic Equations ◽  
Arterial Blood ◽  
Yield Values ◽  
Model Equations

A nonlinear mathematical model of arterial blood flow, which can account for tapering, branching, and the presence of stenosed segments, is presented. With the finite-element method, the model equations are transformed into a system of algebraic equations that can be solved on a high-speed digital computer to yield values of pressure and volume rate of flow as functions of time and arterial position. A model of the human femoral artery is used to compare the effects of linear and nonlinear modeling. During periods of rapid alterations in pressure or flow, the nonlinear model shows significantly different results than the linear model. The effect of a stenosis on pressure and flow waveforms is also simulated, and the results indicate that these waveforms are significantly altered by moderate and severe stenoses.

Chromotomosynthesis for high speed hyperspectral imagery

2012 ◽  
Author(s):  
Randall L. Bostick ◽  
Glen P. Perram
Keyword(s):  
High Speed ◽  
Hyperspectral Imagery

Nonlinear Modeling of Tilting-Pad Bearings With Application to a Flexible Rotor Analysis

2013 ◽  
Author(s):  
Jianming Cao ◽  
Tim Dimond ◽  
Paul Allaire
Keyword(s):  
High Speed ◽  
Dynamic Stiffness ◽  
Nonlinear Modeling ◽  
Transient Behavior ◽  
Pressure Profile ◽  
Flexible Rotor ◽  
Time Step ◽  
Assembly Method ◽  
Tilting Pad ◽  
Tilting Pad Bearings

Tilting-pad bearings are widely used in high-speed rotating machines to improve the system’s stability. Linearized static or dynamic stiffness and damping coefficients are often applied to rotordynamic analyses. This method has limits due to the nonlinear effects of tilting-pad bearing under severe unbalance conditions or large shaft vibration. This work presents a new modeling and assembly method of a linear flexible rotor with nonlinear tilting-pad bearings. The pressure profile on each pad is calculated using an approximate finite element method by solving Reynolds equation derived from a nonlinear tilting-pad bearing model. Nonlinear bearing forces are calculated based upon the shaft instantaneous position and velocity with an update at each time step. Effects of the bearing pad&pivot are evaluated first by applying a rigid rotor on tilting-pad bearings first. The nonlinear transient behavior of a flexible eight-stage compressor supported on two tilting-pad bearings is investigated. The nonlinear numerical transient response of the system under severe unbalance conditions, including coupled motions of bearing pads, bearing pivots and the shaft, and nonlinear bearing forces, is solved using a 4th order Runge-Kutta integration after assembling the system together. Under severe unbalance conditions. Sub and super harmonic response is shown to exist from both rotor and bearing components.

Controller Design Based on Mechatronic Model

2014 ◽  
Vol 526 ◽  
pp. 351-356
Author(s):  
Li Xi Yue ◽  
Jian Hui Zhou ◽  
Yan Nan Lu ◽  
Chong Chong Ji ◽  
Zhi Yong Yu
Keyword(s):  
Neural Network ◽  
High Speed ◽  
Controller Design ◽  
Design Method ◽  
Nonlinear Modeling ◽  
Digital Design ◽  
The Neural Network ◽  
Key Issues ◽  
Neural Network Algorithm ◽  
Computed Torque

The dissertation deals with some key issues relevant to the controller design and digital design method for a newly patented high-speed parallel manipulator. Meanwhile, a Virtual Prototyping based co-simulation platform is also established according to the ADAMS and Matlab/Simulink software. In order to promote the ability that the manipulator traces the prescribed trajectory, a model based computed torque controller is described in detail, and a neural network algorithm is also used to optimize controller parameters real-timely under the consideration of systematic nonlinear, modeling error and outer disturbance. The neural network based computed torque controller increases the robustness of system dramatically.

Vibration control of coupled Duffing oscillators in flexible single-link manipulators

2020 ◽  
pp. 107754632095259
Author(s):  
Jie Huang ◽  
Jinchen Ji
Keyword(s):  
High Speed ◽  
Vibration Suppression ◽  
Control Method ◽  
Negative Impact ◽  
Nonlinear Modeling ◽  
Flexible Manipulator ◽  
Flexible Link ◽  
Structural Nonlinearity ◽  
Single Link ◽  
Coupled Duffing Oscillators

Motion-induced oscillations of the flexible single link and its payload at the tip have negative impact on the anticipated performance of the flexible manipulators and thus should be suppressed to achieve tip positioning accuracy and high-speed operation. Because of the structural flexibility, the dynamics of the flexible manipulator can be described by coupled Duffing oscillators when considering the inherent structural nonlinearity of the flexible link into the dynamic modeling. However, little research has been focused on addressing the dynamic coupling issue in the nonlinear modeling of flexible-link manipulators using coupled Duffing oscillators. This article presents coupled Duffing oscillators for the nonlinear modeling of flexible single-link manipulators and then proposes a control method for suppressing the nonlinear vibrations of the coupled Duffing oscillators. Simulated and experimental results obtained from a flexible single-link manipulator test bench are in good agreement with the proposed nonlinear modeling and also demonstrate the effectiveness of the proposed control techniques for vibration suppression of the flexible manipulator.

scholarly journals VIRTUAL DIMENSIONALITY ESTIMATION IN HYPERSPECTRAL IMAGERY BASED ON UNSUPERVISED FEATURE SELECTION

2016 ◽  
Vol III-7 ◽  
pp. 17-23
Author(s):  
M. Ghamary Asl ◽  
B. Mojaradi
Keyword(s):  
Feature Selection ◽  
High Speed ◽  
Hyperspectral Imagery ◽  
Current Paper ◽  
Estimation Methods ◽  
Tuning Parameters ◽  
Spectral Signatures ◽  
Virtual Dimensionality ◽  
Image Partition ◽  
Partition Space

Virtual Dimensionality (VD) is a concept developed to estimate the number of distinct spectral signatures in hyperspectral imagery. Intuitively, detecting the number of spectrally distinct signatures depends on determining the number of distinct bands of the data. Considering this idea, the current paper aims at estimating the VD based on finding independent bands in the image partition space. Eventually, the number of independent selected bands is accepted as the VD estimate. The proposed method is automatic and distribution-free. In addition, no tuning parameters and noise estimation processes are needed. This method is compared with three well-known VD estimation methods using synthetic and real datasets. Experimental results show high speed and reliability in the performance of the proposed method.

scholarly journals VIRTUAL DIMENSIONALITY ESTIMATION IN HYPERSPECTRAL IMAGERY BASED ON UNSUPERVISED FEATURE SELECTION

2016 ◽  
Vol III-7 ◽  
pp. 17-23 ◽  
Author(s):  
M. Ghamary Asl ◽  
B. Mojaradi
Keyword(s):  
Feature Selection ◽  
High Speed ◽  
Hyperspectral Imagery ◽  
Current Paper ◽  
Estimation Methods ◽  
Tuning Parameters ◽  
Spectral Signatures ◽  
Virtual Dimensionality ◽  
Image Partition ◽  
Partition Space

Virtual Dimensionality (VD) is a concept developed to estimate the number of distinct spectral signatures in hyperspectral imagery. Intuitively, detecting the number of spectrally distinct signatures depends on determining the number of distinct bands of the data. Considering this idea, the current paper aims at estimating the VD based on finding independent bands in the image partition space. Eventually, the number of independent selected bands is accepted as the VD estimate. The proposed method is automatic and distribution-free. In addition, no tuning parameters and noise estimation processes are needed. This method is compared with three well-known VD estimation methods using synthetic and real datasets. Experimental results show high speed and reliability in the performance of the proposed method.

scholarly journals Circuit Tolerance Design Using Belief Rule Base

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Xiao-Bin Xu ◽  
Zheng Liu ◽  
Yu-Wang Chen ◽  
Dong-Ling Xu ◽  
Cheng-Lin Wen
Keyword(s):  
High Speed ◽  
Nonlinear Modeling ◽  
Optimization Method ◽  
Quantitative Information ◽  
Rule Base ◽  
Nonlinear Relationship ◽  
Highly Nonlinear ◽  
Belief Rule Base ◽  
Feasibility Region ◽  
Brb System

A belief rule-based (BRB) system provides a generic nonlinear modeling and inference mechanism. It is capable of modeling complex causal relationships by utilizing both quantitative information and qualitative knowledge. In this paper, a BRB system is firstly developed to model the highly nonlinear relationship between circuit component parameters and the performance of the circuit by utilizing available knowledge from circuit simulations and circuit designers. By using rule inference in the BRB system and clustering analysis, the acceptability regions of the component parameters can be separated from the value domains of the component parameters. Using the established nonlinear relationship represented by the BRB system, an optimization method is then proposed to seek the optimal feasibility region in the acceptability regions so that the volume of the tolerance region of the component parameters can be maximized. The effectiveness of the proposed methodology is demonstrated through two typical numerical examples of the nonlinear performance functions with nonconvex and disconnected acceptability regions and high-dimensional input parameters and a real-world application in the parameter design of a track circuit for Chinese high-speed railway.

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