scholarly journals A Vibration-Isolated Body of Chaotic Prediction

2011 ◽  
Vol 2-3 ◽  
pp. 978-983
Author(s):  
Yong Yi Gao ◽  
Shi Ping Zhan ◽  
Ban Gyan Li
Keyword(s):  
High Frequency ◽  
Simulation Experiment ◽  
Variable Parameter ◽  
Slow Variable ◽  
State Equation ◽  
Analytical Prediction ◽  
Vibration Isolator ◽  
Weak Nonlinearity ◽  
Analog Simulation ◽  
Inherent Frequency

The nonlinear dynamics equation of passive vibration isolator is established in this paper. According to the nonlinear vibration theory, the average equation of slow-varying primary harmonic in the condition of weak nonlinearity is abstained , and derived a discrete mapping of the harmonic slow variable parameter state equation, then get the analytical conditions of chaos in the passive vibration isolator, the analytical results show that only when the vibration frequency of the groundsill is higher than the inherent frequency of the passive vibration isolator, the chaos can be observed, when the groundsill vibrate with the large amplitude and high frequency vibration, the chaos can’t be observed in the passive vibration isolator system. Finally the analytical prediction is validated by analog simulation experiment, and gets the conclusion that the prediction matches well with the simulation results.

scholarly journals An Analytical Prediction Model of Time Diversity Performance for Earth-Space Fade Mitigation

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Pantelis-Daniel M. Arapoglou ◽  
Athanasios D. Panagopoulos ◽  
Panayotis G. Cottis
Keyword(s):  
Prediction Model ◽  
High Frequency ◽  
Rain Attenuation ◽  
Analytical Prediction ◽  
Time Dynamics ◽  
Time Diversity ◽  
Satellite Applications ◽  
Basic Parameters ◽  
Cost Efficient ◽  
General Prediction

Time diversity (TD) has recently attracted attention as a promising and cost-efficient solution for high-frequency broadcast satellite applications. The present work proposes a general prediction model for the application of TD by approximating the time dynamics of rain attenuation through the use of the joint lognormal distribution. The proposed method is tested against experimental data and its performance is investigated with respect to the basic parameters of a satellite link.

Active Vibration Control and Isolation for Micro-Machined Devices

2008 ◽  
Author(s):  
Seong Jin Kim ◽  
Chen Chen ◽  
George Flowers ◽  
Robert Dean
Keyword(s):  
High Frequency ◽  
Vibration Isolation ◽  
Active Vibration Control ◽  
Low Pressure ◽  
High Amplitude ◽  
Vibration Isolator ◽  
Mems Devices ◽  
Mechanical Vibrations ◽  
Mems Gyroscopes ◽  
Filter Structures

Some harsh environments contain high frequency, high amplitude mechanical vibrations. Unfortunately some very useful components, such as MEMS gyroscopes, can be very sensitive to these high frequency mechanical vibrations. Passive micromachined silicon lowpass filter structures (spring-mass-damper) have been demonstrated in recent years. However, the performance of these filter structures is typically limited by low damping. This is especially true if operated in low pressure environments, which is often the optimal operating environment for the attached device that requires vibration isolation. An active micromachined vibration isolator can be realized by combining a state sensor, and electrostatic actuator and feedback electronics with the passive isolator. Using this approach, a prototype active micromachined vibration isolator is realized and used to decrease the filter Q from approximately 135 to approximately 60, when evaluated in a low pressure environment. The physical size of these active isolators is suitable for use in or as packaging for sensitive electronic and MEMS devices, such as MEMS vibratory gyros.

Applied Research of Frequency Discriminator Based on LabVIEW

2014 ◽  
Vol 910 ◽  
pp. 323-326
Author(s):  
Shu Lai Liang ◽  
Zhao Peng Li ◽  
Zhou Guo Hou
Keyword(s):  
Virtual Instrument ◽  
High Frequency ◽  
Applied Research ◽  
Simulation Experiment ◽  
Virtual Machines ◽  
Virtual Experiment ◽  
Development Platform ◽  
Frequency Discriminator

This article through introduction tradition high frequency laboratory existence shortcoming and malpractice , Proposed the idea of Virtual instrument made for high-frequency laboratory ,then introduced the characteristic of LabVIEW (a development platform for virtual experiment),And proved the feasibility of using virtual machines have the discriminator through the simulation experiment .

Analysis of Axial Vibration in the Laminated Rubber-Metal Spring

2013 ◽  
Vol 845 ◽  
pp. 46-50 ◽  
Author(s):  
Mohd Azli Salim ◽  
Azma Putra ◽  
Mohd Azman Abdullah
Keyword(s):  
High Frequency ◽  
Axial Direction ◽  
Vibration Isolator ◽  
Axial Vibration ◽  
Parameter System ◽  
Internal Resonances ◽  
Lumped Parameter ◽  
Metal Plates ◽  
Vibration Transmissibility ◽  
Earthquake Protection

The laminated rubber-metal spring is well known in application as the vibration isolator for earthquake protection. The spring is therefore designed to be able to sustain the vibration waves from horizontal direction. This paper discusses the possibility of the laminated spring to be employed for other applications where the excitation mainly comes from axial direction, such as to isolate vibration transmission from heavy engine. The model is first developed for a simple finite rod to simulate the effect of internal resonances at high frequency when the wavelength is much smaller than the length of the rod. The effect of metal plates inserted in the rubber is then modelled using the lumped parameter system. The results are presented in terms of the vibration transmissibility.

Application with Wavelet Detection to Signal Process of SINS

2012 ◽  
Vol 571 ◽  
pp. 671-675
Author(s):  
Xiang Yuan Huang ◽  
Xia Qing Tang ◽  
Li Bi Guo ◽  
Xu Wei Cheng
Keyword(s):  
High Frequency ◽  
Simulation Experiment ◽  
Detection Method ◽  
Low Frequency ◽  
Frequency Noise ◽  
Wavelet Filter ◽  
Initial Alignment ◽  
Signal Process ◽  
Signal Characteristic ◽  
Alignment Process

Aimed at disturbance caused from motor running and personnel ambulation during initial alignment process of SINS, a new signal detection method of disturbance based on wavelet analysis is brought out. Through analyzing original signal characteristic of FOG and the data with wavelet filter on disturbance base, finds out wavelet filter just have effectiveness to high frequency noise. Then T&L signal detecting law is introduced, and builds T&L signal with high frequency part of wavelet decomposing to estimates interfere time and then resample. Offline simulation experiment results indicate the method can eliminate low frequency disturbance effectively and has certain apply value.

scholarly journals Extracting super-resolution details directly from a diffraction-blurred image or part of its frequency spectrum

2019 ◽  
Author(s):  
Edward Y Sheffield
Keyword(s):  
High Frequency ◽  
Simulation Experiment ◽  
Fourier Spectrum ◽  
Low Frequency ◽  
Super Resolution ◽  
Diffraction Limit ◽  
Full Information ◽  
High Frequency Part ◽  
Blurred Image ◽  
Blurred Images

It is usually believed that the low frequency part of a signal’s Fourier spectrum represents its profile, while the high frequency part represents its details. Conventional light microscopes filter out the high frequency parts of image signals, so that people cannot see the details of the samples (objects being imaged) in the blurred images. However, we find that in a certain “resolvable condition”, a signal’s low frequency and high frequency parts not only represent profile and details respectively. Actually, any one of them also contains the full information (including both profile and details) of the sample’s structure. Therefore, for samples with spatial frequency beyond diffraction-limit, even if the image’s high frequency part is filtered out by the microscope, it is still possible to extract the full information from the low frequency part. On the basis of the above findings, we propose the technique of Deconvolution Super-resolution (DeSu-re), including two methods. One method extracts the full information of the sample’s structure directly from the diffraction-blurred image, while the other extracts it directly from part of the observed image’s spectrum (e.g., low frequency part). Both theoretical analysis and simulation experiment support the above findings, and also verify the effectiveness of the proposed methods.

scholarly journals Estimation of Electrical Performance of a Polymer Insulator with Deposited Moss on the Surface under Impulse Voltage Condition in Foggy Weather

2018 ◽  
Vol 4 (4) ◽  
pp. 1
Author(s):  
Farah Asyikin Abd Rahman ◽  
Izadi M ◽  
Kadir M.Z.A. Ab ◽  
Jasni J
Keyword(s):  
Electric Field ◽  
Field Distribution ◽  
High Frequency ◽  
Electric Field Distribution ◽  
Simulation Experiment ◽  
Electrical Performance ◽  
High Frequency Structure Simulator ◽  
Polymer Insulator ◽  
Pollution Flashover ◽  
Field Behaviour

This paper presents a study about electric field behaviour of 10kV polymer insulator with moss deposition under foggy condition. The aim of this simulation experiment was to determine if this field affect the initiation of pollution flashover. To study this effect, simulations were carried out using High Frequency Structure Simulator (HFSS). The simulation experiment includes the results of electric field distribution along the insulator and also the magnitude of electric field at three different locations in identifying the parts of the insulator’s surface that likely to initiate pollution flashover. The moss deposited polymer insulator displayed uniformed and considerably intense distribution of electric field with the clean insulator. The field result showed the likelihood in discharging a corona effect.  In short, the results indicated that electric field along the insulator surface would likely be influenced by moss deposition and foggy air.

Free Oscillations of a Damped Simple Pendulum: An Analog Simulation Experiment

2019 ◽  
Vol 01 (04) ◽  
pp. 1950015 ◽  
Author(s):  
Ivan Skhem Sawkmie ◽  
Mangal C. Mahato
Keyword(s):  
Harmonic Oscillator ◽  
Free Oscillation ◽  
Simulation Experiment ◽  
Free Oscillations ◽  
Analog Simulation ◽  
Simple Pendulum ◽  
Electronic Circuitry ◽  
Undergraduate Laboratory ◽  
Angular Amplitude ◽  
Theoretical Results

The frequency of free oscillation of a damped simple pendulum with large amplitude depends on its amplitude unlike the amplitude-independent frequency of oscillation of a damped simple harmonic oscillator. This aspect is not adequately emphasized in the undergraduate courses due to experimental and theoretical difficulties. We propose an analog simulation experiment to study the free oscillations of a simple pendulum that could be performed in an undergraduate laboratory. The needed sinusoidal potential is obtained approximately by using the available AD534 IC by suitably augmenting the electronic circuitry. To keep the circuit simple enough we restrict the initial angular amplitude of the simple pendulum to a maximum of [Formula: see text]. The results compare well qualitatively with the theoretical results. The small quantitative discrepancy is attributed to the inexact nature of the used “sinusoidal potential”.

Research of Image Compression Based on Fractal Coding

2012 ◽  
Vol 241-244 ◽  
pp. 418-422
Author(s):  
Dong Mei Wang ◽  
Jing Yi Lu
Keyword(s):  
Wavelet Transform ◽  
Theoretical Analysis ◽  
Image Compression ◽  
High Frequency ◽  
Wavelet Transformation ◽  
Simulation Experiment ◽  
Low Frequency ◽  
Reconstructed Image ◽  
Wavelet Domain ◽  
Fractal Coding

The EZW and Fractal Coding were researched and simulated in this paper. And two drawbacks were discovered in these algorithm:the coding time is too long and the effect of reconstructed image is not ideal. Therefore, The paper studied the wavelet transformation in the fractal coding application, The wavelet coefficients of an image present two characteristics when the image is processed by wavelet transform: first characteristic is that the energy of an image is strongly concentrated in low frequency sub-image, second characteristic is that there is a similarity between the same direction in high frequency sub-images.but the fractal coding essence was precisely uses the similarity of wavelet transform image. The paper designed one kind of new Image Compression based on Fractal Coding in wavelet domain. The theoretical analysis and the simulation experiment indicated that, to some extent the method can reduce the coding time and reduce the MSE and enhance compression ratio of the reconstructed image and improve PSNR of the reconstructed image..

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