Application of Pseudo-Random Test Signals and Cross Correlation to the Identification of Bulk Handling Plant Dynamic Characteristics

1973 ◽  
Vol 95 (1) ◽  
pp. 31-36 ◽  
Author(s):  
A. W. Roberts ◽  
W. H. Charlton
Keyword(s):  
Dynamic Characteristics ◽  
Cross Correlation ◽  
Natural Frequencies ◽  
Statistical Technique ◽  
Response Analysis ◽  
Frequency Response Analysis ◽  
Grain Handling ◽  
Extraneous Noise ◽  
Cross Correlation Analysis

In the determination of the dynamic characteristics of bulk handling systems the complexity of the problem usually makes experimental identification necessary. Experimental techniques which are based on statistical methods are known to be more reliable than conventional methods such as frequency response analysis. A statistical technique that employs a pseudo-random binary coded signal (prbs) to perturbate the system followed by cross correlation analysis may be used very effectively to identify the dynamic characteristics of the system even in the presence of extraneous noise signals. This paper describes this technique and discusses its application to two areas in the bulk handling field; the first deals with the determination of the natural frequencies of screw conveyors used for grain handling and the second deals with the identification of the dynamic characteristics of grain discharge chutes.

scholarly journals First Determination of 2D Speed Distribution within the Bodies of Coronal Mass Ejections with Cross-correlation Analysis

2019 ◽  
Vol 880 (1) ◽  
pp. 41 ◽  
Author(s):  
Beili Ying ◽  
Alessandro Bemporad ◽  
Silvio Giordano ◽  
Paolo Pagano ◽  
Li Feng ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Coronal Mass Ejections ◽  
Cross Correlation ◽  
Speed Distribution ◽  
Cross Correlation Analysis

scholarly journals Automated Threshold Determination of Auditory Evoked Brainstem Responses by Cross-correlation Analysis with Varying Sweep Number

2019 ◽  
Author(s):  
Haoyu Wang ◽  
Bei Li ◽  
Xu Ding ◽  
Xueling Wang ◽  
Zhiwu Huang ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Test Procedure ◽  
Auditory Brainstem ◽  
Time Shift ◽  
Strong Response ◽  
Reliable Determination ◽  
Threshold Determination ◽  
Cross Correlation Analysis ◽  
Brainstem Response

ABSTRACTAuditory brainstem response (ABR) is widely employed to evaluate the hearing function, both in clinics and basic research. Despite many attempts for automation over decades, reliable determination of threshold stimulus level still relies on human visual identification of waveform, which oftentimes is subjective. Here, we report a robust procedure for automatic and accurate threshold determination in both mouse and human ABR. Contrary to prior approaches, in our new threshold determination algorithm, the on-going averaging is stopped once the waveform is confirmed by a cross-correlation time shift approach. The flexible ending sweep numbers for different stimuli is used to inform the threshold determination. We found a good match of the threshold readings between the algorithm and the human judges. Moreover, in the algorithm, smaller sweep number is required for strong response from supra-threshold level, and thus a considerable portion of sweeps can be saved in comparison to the case with level averaging of a fix number. These features are attractive and implementation of this method in commercial devices will make the ABR test procedure more objective and efficient.

Dynamic Characteristics Analysis and Topology Optimization of Column Based on Finite Element Method

2013 ◽  
Vol 721 ◽  
pp. 541-544
Author(s):  
Jing Chen ◽  
Ze Long Yang ◽  
Xian Xuan Li
Keyword(s):  
Finite Element ◽  
Topology Optimization ◽  
Frequency Response ◽  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Response Analysis ◽  
Response Curves ◽  
Element Analysis ◽  
Column Structure

Aiming to improve the dynamic and static characteristics of a type of machining center column, the finite element modal analysis and harmonic response analysis of the column are performed, and this paper analyzes the dynamic characteristics of the column based on the first five mode shapes and natural frequencies of the column and the displacement - frequency response curves of the column. Topology optimization analysis of the column is performed with ANSYS, and the finite element analysis is performed on the column again after the column structure is improved based on the optimal distribution of material of the column structure and the design experience of column. The result shows that the first five natural frequencies of the column increase, the peak of the displacement - frequency response of the column decrease, and the dynamic characteristics are improved significantly.

Investigations on Dynamic Analysis of Propeller Shaft

2014 ◽  
Vol 592-594 ◽  
pp. 1225-1234
Author(s):  
Girish Bhiogade ◽  
Jiwak G. Suryawanshi
Keyword(s):  
Cross Sections ◽  
Response Analysis ◽  
Shear Stresses ◽  
Propeller Shaft ◽  
Frequency Response Analysis ◽  
Operation Speed ◽  
Modal Amplitude ◽  
Bending Stresses ◽  
To Come

In recent years investigation of torsional vibration characteristics of the shaft systems transmitting torque, has become important part of the designer’s responsibility. Satisfactory operation of heavy duty transmission system may depend to a large extent upon the successful handling of the vibration problem. Propeller shaft of most of the vehicles are found to show number of modes of failures. Most destructive failure after thorough study of the system involving Propeller shaft is rupture of tubes & excessive bending caused due to torsional shear stresses that get imposed during running time of propeller shaft. Based upon above problem, new methodology has been devised to come up with new technique for determination of torsional stresses across cross sections of the shafts. TATA LP/LPO 1510 model chosen for the propeller shaft analysis and data provided by M.S.R.T.C. workshop bhandara (M.S.). Frequency response analysis (FRA) that has been worked out in found to show number of failures modes, each mode being representation of operation speed which is equal to excited natural frequency. Predicted frequency range is having excellent with practical results. Stresses that are obtained are of low magnitude (torsional stresses) but effect of this low modal amplitude will be excessive bending of shaft which causes the bending stresses of 72 N/mm2 while permissible is 83.7 N/mm2.

CROSS‐CORRELATION FILTERING

Geophysics ◽  
1954 ◽  
Vol 19 (4) ◽  
pp. 660-683 ◽  
Author(s):  
Hal J. Jones ◽  
John A. Morrison
Keyword(s):  
Correlation Analysis ◽  
Cross Correlation ◽  
Power Spectra ◽  
Correlation Coefficients ◽  
Quantitative Measure ◽  
Additional Information ◽  
Analog Computing ◽  
Cross Correlation Analysis ◽  
Prediction Problems

Correlation analysis techniques may be applied to seismic data already subjected to standard recording and analysis procedure in an effort to extract additional information, or to raw data as an alternative filtering method. These techniques involve determination of certain parameters which provide a quantitative measure of the correlation between two sets of data. Among the most useful of these parameters are the auto‐ and cross‐correlation coefficients and functions long used by statisticians in time series analysis and recently applied to filtering and prediction problems in the field of communications. This paper discusses some applications of correlation analysis in interpretation of seismograms. The use of cross‐correlation analysis to identify weak reflections masked by high noise is illustrated for several problems. Equivalence of correlation analysis procedures to filtering operations is stressed. Special analog computing equipment facilitating computation of correlation coefficients and power spectra directly from oscillograms or graphs is described. A brief discussion of modern optimum filter theory is presented.

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