scholarly journals Evaluation of Dynamic Uncertainty of Rolling Bearing Vibration Performance

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Liang Ye ◽  
Xintao Xia ◽  
Zhen Chang
Keyword(s):  
Time Series ◽  
Chaos Theory ◽  
Maximum Entropy Method ◽  
Bootstrap Method ◽  
Rolling Bearing ◽  
Entropy Method ◽  
Performance Time ◽  
Dynamic Uncertainty ◽  
Bearing Vibration ◽  
Vibration Performance

The variation trend, failure trajectory, probability distribution, and other information vary with time and working conditions for rolling bearing vibration performance, which makes the evaluation and prediction of the evolution process difficult for the performance reliability. In view of this, the chaos theory, grey bootstrap method, and maximum entropy method were effectively fused to propose a mathematical model for the dynamic uncertainty evaluation of rolling bearing vibration performance. After reconstructing the phase space of the vibration performance time series, four local prediction methods were applied to predict the vibration values of bearings to verify the effectiveness and validity of chaos theory. The estimated true value and estimated interval were calculated using the grey bootstrap method (GBM) and maximum entropy method. Finally, the validity of the proposed model was verified by comparing the probability that the original data fall into the estimated interval with the given confidence level. The experimental results show that the proposed method can effectively predict the variation trend and failure trajectory of the vibration performance time series so as to realize the dynamic monitoring of the evolution process for rolling bearing vibration performance online.

scholarly journals Spectral characteristics of Atlantic seasonal storm frequency

MAUSAM ◽  
2021 ◽  
Vol 57 (4) ◽  
pp. 597-608
Author(s):  
R. P. KANE
Keyword(s):  
Time Series ◽  
Maximum Entropy Method ◽  
Southern Oscillation ◽  
Spectral Characteristics ◽  
Entropy Method ◽  
Sea Surface ◽  
Low Latitude ◽  
Storm Activity ◽  
Oscillation Phenomenon ◽  
Storm Frequency

lkj & o"kZ 1900&2000 dh vof/k esa vVykafVd egklkxj dh rwQkuh xfrfof/k ¼ftUgas rwQku] izpaM rwQku] vkfn uke fn, x, gaS½ ds fofHkUu lwpdkadksa ds dky Jsf.k;ksa dk vuqØe fo’ys"k.k ,e-b-,e-¼vf/kdre ,uVªkWih fof/k½ }kjk rFkk mldh vkofrZrk ds vk;ke ,e- vkj- ,- ¼cgqq lekJ;.k fo’ys"k.k½ }kjk izkIr fd, x, gaSA fiNys dqN o"kksZa ds vkadM+ksa ¼o"kZ 1950 ls vkxss½ ds vuqlkj budh egRoiw.kZ vkofrZrk,¡ n’kd lfgr( f}okf"kZd dYi] f=okf"kZd dYi {ks=ksa rFkk buls mPp {ks=ksa esa Hkh jghA 2-40 o"kkasZ esa 50 feyhckj ds fuEu v{kka’k {ks=h; iou vkSj 2-40 ,oa 2-85 o"kkasZ ds b- ,u- ,l- vks- ¼,y uhuks/nf{k.kh nksyu½ ?kVuk ds ln`’k f}o"khZ dYi nksyu {ks= esa ¼3&4 o"kkasZ½ rwQku lwpdkad 2-40 rFkk 2-85 o"kksZa ds djhc pje ij jgsA mPp vkofrZrk okys {ks=ksa esa rwQku lwpdkad 4-5&5-5-] 8&9] 11&12 rFkk 14&15 o"kkasZ esa pje ij jgs tcfd b- ,u- ,l- vks- 7-4 ,oa 12&14 o"kksZa esa pje ij jgsA cgq n’kdh; Js.kh esa 28&34]40]50&53]61&63]~70 ,oa ~80 o"kksZa esa ¼ijUrq fHkUu lwpdkadksa ds fy, fHkUu&fHkUu½ rwQku pje ij jgs tks LFky ,oa leqnzh lrg ds rkiekuksa ds leku pje ekuksa ds vuq:Ik jgsA dqy lwpdkadksa esa 90 o"kkZsa esa yxHkx 50 izfr’kr dh m/oZ izo`fr jghA     The time series of the various indices of Atlantic storm activity (number of named storms, hurricanes, etc.) for 1900-2000 were subjected to spectral analysis by MEM (Maximum Entropy Method) and amplitudes of the periodicities were obtained by MRA (Multiple Regression Analysis).  For recent data (1950 onwards), significant periodicities were in the quasi-biennial, quasi-triennial regions and also in higher regions, including decadal. In the QBO region (2-3 years), storm indices had peaks near 2.40 and 2.85 years, similar to 2.40 years of 50 hPa low latitude zonal wind and 2.40 and 2.85 years of ENSO (El Niño/Southern Oscillation) phenomenon. In the QTO region (3-4 years), storm indices and ENSO had common peaks near 3.5 years. In higher periodicity regions, storm indices had peaks at 4.5-5.5, 8-9, 11-12 and 14-15 years, while ENSO had peaks at 7.4 and 12-14 years. In the multi-decadal range, storm peaks were at 28-34, 40, 50-53, 61-63, ~70 and ~80 years (but different for different indices), which matched with similar peaks in land and sea surface temperatures. Some indices had large uptrends, ~50% in 90 years.

Standard Uncertainty of Rolling Bearing Vibration as Time Series

2011 ◽  
Vol 382 ◽  
pp. 133-136
Author(s):  
Xin Tao Xia ◽  
Lei Lei Gao ◽  
Xiao Chao Sun
Keyword(s):  
Time Series ◽  
Measurement Theory ◽  
Failure Process ◽  
Rolling Bearing ◽  
Standard Uncertainty ◽  
Bearing Failure ◽  
Vibration Acceleration ◽  
Rolling Bearings ◽  
Vibrational Acceleration ◽  
Bearing Vibration

The standard uncertainty in the measurement theory is applied to evaluate the change of the rolling bearing vibration acceleration generated by the failure on the surface of the ring raceway. The time series are obtained via the experimental investigation on the vibrational acceleration of the rolling bearings with different failure diameters. And the result shows that the standard uncertainty of the vibrational acceleration increases nonlinearly with the failure diameter, revealing a new characteristic of the variation of the rolling bearing failure process. It follows that for a rolling bearing in running, the failure process can be described by the standard uncertainty of its vibration acceleration, laying a foundation for failure warning of a rolling bearing.

scholarly journals Trends and fluctuations of the cyclonic systems over North Indian Ocean

MAUSAM ◽  
2021 ◽  
Vol 52 (1) ◽  
pp. 37-46
Author(s):  
D. V. BHASKAR RAO ◽  
C. V. NAIDU ◽  
B. R. SRINIVASA RAO
Keyword(s):  
Time Series ◽  
Indian Ocean ◽  
Maximum Entropy Method ◽  
Entropy Method ◽  
North Indian Ocean ◽  
Pass Filter ◽  
Long Term Trends ◽  
High Pass ◽  
Cyclone Frequency

The data of the monthly cyclone frequencies over North Indian Ocean for the period 1877-1998 has been analysed to study the long-term trends and fluctuations. Analysis has been made separately for depressions and cyclones for the pre-monsoon, monsoon and post-monsoon seasons along with the annual frequencies. The data was subjected to 11-year moving averages and the epochs of increasing and decreasing trends have been identified. A consistent decreasing trend after 1950s is a notable feature.   The time series of the monthly cyclone frequency were passed through a high-pass filter to eliminate periods greater than 21 years and then subjected to spectrum analysis using Maximum Entropy Method to obtain dominant periodicities. Three significant periodicities at 2.2-2.8; 3.5-6.5 and 10-15 years have been identified which could be attributed to QBO, ENSO and decadal frequencies.

504 Chaos time series analysis of rolling bearing vibration

2015 ◽  
Vol 2015.53 (0) ◽  
pp. _504-1_-_504-2_
Author(s):  
Toshiya GOTO ◽  
Yasuhisa SEKIGUCHI
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Rolling Bearing ◽  
Series Analysis ◽  
Bearing Vibration

Evaluation of Rolling Bearing Vibration Using Fuzzy Set Theory and Chaos Theory

2012 ◽  
Vol 424-425 ◽  
pp. 338-341 ◽  
Author(s):  
Xiao Chao Sun ◽  
Xin Tao Xia ◽  
Yan Bin Liu ◽  
Lei Lei Gao
Keyword(s):  
Phase Space ◽  
Set Theory ◽  
Fuzzy Set ◽  
Chaos Theory ◽  
Fuzzy Set Theory ◽  
Rolling Bearing ◽  
Similarity Coefficient ◽  
Vibration Acceleration ◽  
Fuzzy Similarity ◽  
Bearing Vibration

The optimal fuzzy similarity coefficient based on the phase space is proposed to evaluate the rolling bearing vibration acceleration generated by wear on the surface of the ring raceway. The phase space of the time series of the rolling bearing vibration acceleration is reconstructed via the chaos theory, the fuzzy similarity relation between the phase trajectories is established by the fuzzy set theory, and then the optimal fuzzy similarity coefficient is obtained through a reasonable choice of the embedding dimension and the delay. Experimental investigation shows that with the increase of the fault diameter, the optimal fuzzy similarity coefficient decreases nonlinearly

Periodicity of Ovarian Follicular Dynamics in Postpartum Cows Demonstrated Using Time-Series Analysis Based on the Maximum Entropy Method.

1996 ◽  
Vol 42 (2) ◽  
pp. 117-124
Author(s):  
Hiroeki SAHARA ◽  
Kanta EZOE ◽  
Hideo FUKUOKA ◽  
Norio OHTOMO ◽  
Yukio TANAKA ◽  
...  
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Maximum Entropy ◽  
Maximum Entropy Method ◽  
Entropy Method ◽  
Series Analysis ◽  
Follicular Dynamics

Chaos Prediction of Rolling Bearing Friction Torque

2010 ◽  
Vol 26-28 ◽  
pp. 190-193 ◽  
Author(s):  
Xin Tao Xia ◽  
Tao Mei Lv
Keyword(s):  
Time Series ◽  
Experimental Investigation ◽  
Chaos Theory ◽  
Rolling Bearing ◽  
Friction Torque ◽  
Local Region ◽  
Space Applications ◽  
Region Method ◽  
Weight One ◽  
Bearing Friction

Based on the chaos theory, the adding-weight one-rank local-region method was applied to predict the time series of the rolling bearing friction torque. The experimental investigation on the rolling bearing for space applications shows that the method is able to predict effectively the rolling bearing friction torque, only with very small predicted error.

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