The Principle of Cepstrum and its Application in Quantitative Fault Diagnostics of Gears

1991 ◽  
Author(s):  
He Tang ◽  
Jian-Zhong Cha ◽  
Yuanhui Wang ◽  
Ce Zhang
Keyword(s):  
Theoretical Analysis ◽  
Noise Signal ◽  
Experimental Results ◽  
New Method ◽  
Fault Diagnostics ◽  
Gear Noise ◽  
Gear Mesh ◽  
Cepstrum Analysis

Abstract This paper has studied the principle of cepstrum and introduced a new method which can be used to quantitatively diagnose gear-wear through cepstrum analysis of gear noise. The amplitude value of the peak in cepstrum, which represents gear mesh-harmonics in spectrum, is independent of the intensity of gear noise signal. The value can indicate quantitatively the existence of gear-wear. In the paper, the further interpretation on physical meanings of other peaks in cepstrum has been done. Based on analysing the results of experiments with gearboxes, the thresholds of the gear wear by cepstrum diagnosis have been obtained. The theoretical analysis has agreed with the experimental results very well.

scholarly journals RESEARCH ON SHORT-CIRCUIT IMPEDANCES OF NEW CONVERTER TRANSFORMER

2020 ◽  
Vol 38 (02) ◽  
Author(s):  
TRAN THANH NGOC
Keyword(s):  
Theoretical Analysis ◽  
Topological Structure ◽  
Short Circuit ◽  
Experimental Results ◽  
New Method ◽  
Mathematical Relationship ◽  
Hvdc System ◽  
Grid Side ◽  
Relationship Of ◽  
Circuit Impedance

The short-circuit impedance of converter transformers is one of the most important specifications in HVDC system. Compared with the traditional converter transformers, the new converter transformer has unique windings connection diagrams. Based on the topological structure of the new converter transformer, this paper proposes a new method to establish the mathematical relationship of short-circuit impedances and filters impedances under considering the valve side and grid side shortcircuit conditions. The analysis on short circuit at valve side and grid side shows that short-circuit impedances values are almost the same in both two conditions, so that the impedance of the new converter transformer is symmetrical. Finally, simulation and experimental results verify the correctness of the theoretical analysis.

NON-DIVERGING DARK-HOLLOW BEAM GENERATION WITH A PIGTAILED LASER DIODE

2008 ◽  
Vol 17 (03) ◽  
pp. 305-314
Author(s):  
M. BRUNEL ◽  
D. MGHARAZ ◽  
S. COETMELLEC ◽  
A. BOULEZHAR
Keyword(s):  
Theoretical Analysis ◽  
Laser Diode ◽  
Single Mode ◽  
Experimental Results ◽  
New Method ◽  
Circular Aperture ◽  
Hollow Beam ◽  
Beam Generation ◽  
Hollow Beams

A new method to generate non-diverging dark-hollow beams at the output of a single-mode pigtailed laser diode is presented. It consists of positioning a circular aperture at the output of the fiber. The dark-hollow beam generated exhibits an angle of divergence as low as 0.28 degrees. The beam can then be collimated by a lens to observe a non-diverging dark-hollow beam which conserves its structure over more than 20 cm. Experimental results are well-predicted by the theoretical analysis that we have developed.

A New Image Encryption Algorithm of Input-Output Feedback Based on Multi-Chaotic System

2010 ◽  
Vol 40-41 ◽  
pp. 924-929
Author(s):  
Yong Yi Mao ◽  
Zi Chao Deng
Keyword(s):  
Theoretical Analysis ◽  
Image Encryption ◽  
Chaotic System ◽  
Output Feedback ◽  
Logistic Map ◽  
Experimental Results ◽  
New Method ◽  
Encryption Algorithm ◽  
Input Output ◽  
Image Encryption Algorithm

In this paper, a new method is proposed for image encryption by using Transformed Logistic map and Cat map. First, the Transformed logistic map is used to generating two coordinate sequences, and then the primary image's pixels shuffled by the two coordinate sequences. After shuffling, the key stream is produced by the Cat map to encrypt the shuffled image. Theoretical analysis and experimental results indicate that the proposed algorithm has a perfect encryption effect and can resist common attacks

PHOTOINDUCED NONLINEAR OCTUPOLAR POLARIZATION: TRANSIENT AND PERMANENT REGIMES

1996 ◽  
Vol 05 (04) ◽  
pp. 653-670 ◽  
Author(s):  
CÉLINE FIORINI ◽  
JEAN-MICHEL NUNZI ◽  
FABRICE CHARRA ◽  
IFOR D.W. SAMUEL ◽  
JOSEPH ZYSS
Keyword(s):  
Theoretical Analysis ◽  
Second Harmonic ◽  
Experimental Results ◽  
Polar Field ◽  
Rotational Spectrum ◽  
Dual Frequency ◽  
One Dimensional ◽  
Ethyl Violet ◽  
Disperse Red 1 ◽  
Good Agreement

An original poling method using purely optical means and based on a dual-frequency interference process is presented. We show that the coherent superposition of two beams at fundamental and second-harmonic frequencies results in a polar field with an irreducible rotational spectrum containing both a vector and an octupolar component. This enables the method to be applied even to molecules without a permanent dipole such as octupolar molecules. After a theoretical analysis of the process, we describe different experiments aiming at light-induced noncentrosymmetry performed respectively on one-dimensional Disperse Red 1 and octupolar Ethyl Violet molecules. Macroscopic octupolar patterning of the induced order is demonstrated in both transient and permanent regimes. Experimental results show good agreement with theory.

A new method for monitoring the redox potential of fuel salt based on the deposition of 95Nb on Hastelloy C276

2021 ◽  
Vol 109 (5) ◽  
pp. 357-365
Author(s):  
Zhiqiang Cheng ◽  
Zhongqi Zhao ◽  
Junxia Geng ◽  
Xiaohe Wang ◽  
Jifeng Hu ◽  
...  
Keyword(s):  
Redox Potential ◽  
Molten Salt ◽  
Specific Activity ◽  
Chemical Reduction ◽  
Quantitative Approach ◽  
Experimental Results ◽  
New Method ◽  
Molten Salt Reactor ◽  
Fuel Salt ◽  
Well Correlation

Abstract To develop the application of 95Nb as an indicator of redox potential for fuel salt in molten salt reactor (MSR), the specific activity of 95Nb in FLiBe salt and its deposition of 95Nb on Hastelloy C276 have been studied. Experimental results indicated that the amount of 95Nb deposited on Hastelloy C276 resulted from its chemical reduction exhibited a positive correlation with the decrease of 95Nb activity in FLiBe salt and the relative deposition coefficient of 95Nb to 103Ru appeared a well correlation with 95Nb activity in FLiBe salt. Both correlations implied that the measurement of 95Nb activity deposited on Hastelloy C276 specimen might provide a quantitative approach for monitoring the redox potential of fuel salt in MSR.

scholarly journals A Novel Concept Acquisition Approach Based on Formal Contexts

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Ting Qian ◽  
Ling Wei
Keyword(s):  
Data Analysis ◽  
Formal Concept Analysis ◽  
Real Life ◽  
Experimental Results ◽  
New Method ◽  
Concept Acquisition ◽  
Formal Concept ◽  
Knowledge Processing ◽  
Formal Concepts ◽  
Novel Concept

As an important tool for data analysis and knowledge processing, formal concept analysis (FCA) has been applied to many fields. In this paper, we introduce a new method to find all formal concepts based on formal contexts. The amount of intents calculation is reduced by the method. And the corresponding algorithm of our approach is proposed. The main theorems and the corresponding algorithm are examined by examples, respectively. At last, several real-life databases are analyzed to demonstrate the application of the proposed approach. Experimental results show that the proposed approach is simple and effective.

Implementation of a High-Precision Ultrasonic Rain Gauge

2013 ◽  
Vol 300-301 ◽  
pp. 382-388
Author(s):  
Zhan Wei Xu ◽  
Gui Lin Zheng
Keyword(s):  
Theoretical Analysis ◽  
High Precision ◽  
Rain Gauge ◽  
Experimental Results ◽  
Full Description ◽  
Self Calibration ◽  
Velocity Of Ultrasound

A novel rain gauge based on acoustic self-calibration principle is proposed in the paper. Acoustic self-calibration principle can eliminate the uncertainty of the velocity of ultrasound and achieve accurate measurement of rainfall. The rain gauge not only overcomes the influence on the rainfall measurement under intensive rainfall conditions, but also improves the precision of rain gauge. Plenty of experiments have been done to validate the design. Both theoretical analysis and experimental results show the effectiveness of the rain gauge. A full description of the rain gauge and implementation are presented.

A modified Runge-Kutta method

SIMULATION ◽  
1968 ◽  
Vol 10 (5) ◽  
pp. 221-223 ◽  
Author(s):  
A.S. Chai
Keyword(s):  
Error Estimate ◽  
Linear Combination ◽  
Experimental Results ◽  
The Other ◽  
New Method ◽  
Kutta Method ◽  
Starting Values ◽  
Runge Kutta Method ◽  
Runge Kutta ◽  
A Minor

It is possible to replace k2 in a 4th-order Runge-Kutta for mula (also Nth-order 3 ≤ N ≤ 5) by a linear combination of k1 and the ki's in the last step, using the same procedure for computing the other ki's and y as in the standard R-K method. The advantages of the new method are: It re quires one less derivative evaluation, provides an error estimate at each step, gives more accurate results, and needs a minor change to switch to the RK to obtain the starting values. Experimental results are shown in verification of the for mula.

SINS Installation Error Calibration Based on Multi-Position Combinations

2011 ◽  
Vol 383-390 ◽  
pp. 4213-4220
Author(s):  
Zhen Huan Wang ◽  
Xi Jun Chen ◽  
Qing Shuang Zeng
Keyword(s):  
Theoretical Analysis ◽  
Least Squares ◽  
Rotation Rate ◽  
Scale Factor ◽  
New Method ◽  
Earth’S Rotation ◽  
Earth's Rotation ◽  
Error Calibration ◽  
Sine And Cosine Functions ◽  
Cosine Functions

A new method is proposed to calibrate the installation errors of SINS. According to the method, the installation errors of the gyro and accelerometer can be calibrated simultaneously, which not depend on latitude, gravity, scale factor and earth's rotation rate. By the multi-position combinations, the installation errors of the gyro and accelerometer are modulated into the sine and cosine functions, which can be identified respectively based on the least squares. In order to verify the correctness of the theoretical analysis, the SINS is experimented by a three-axis turntable, and the installation errors of the gyro and accelerometer are identified respectively according to the proposed method. After the compensation of the installation error, the accuracy of the SINS is improved significantly.

Cutting Speed of Electric Discharge Machining for SiC Ingot

2012 ◽  
Vol 717-720 ◽  
pp. 861-864 ◽  
Author(s):  
Hideki Yamada ◽  
Satarou Yamaguchi ◽  
Norimasa Yamamoto ◽  
Tomohisa Kato
Keyword(s):  
Silicon Carbide ◽  
Electric Discharge ◽  
Cutting Speed ◽  
Experimental Results ◽  
New Method ◽  
Electric Discharge Machining ◽  
Hard Materials ◽  
Diameter Ingot ◽  
Diamond Saw

A new method based on electric discharge machining (EDM) was developed for cutting a silicon carbide (SiC) ingot. The EDM method is a very useful technique to cut hard materials like SiC. By cutting with the EDM method, kerf loss and roughness of sample are generally smaller than those obtained by cutting with a diamond saw. Moreover, the warpage is smaller than that by the diamond saw cutting, and the cutting speed can be 10 times faster than that of the diamond saw at the present time. We used wires of 50 mm and 100 mm diameters in the experiments, and the experimental results of the cutting speed and the kerf losses are presented. The kerf loss of the 50 mm wire is less than 100 mm, and the cutting speed is about 0.8 mm/min for the thickness of a 6 mm SiC ingot. If we can maintain the cutting speed, the slicing time of a 2 inches diameter ingot would be about seven hours.

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