Solving End-point problem

Method

• DMP have more serious end-point problem then EEMD• Test extraction should be performed to ensure the behavior of DMP

and EEMD modes• Observe the range of EEMD that may combine with DMP• Adjust COMB(6) and COMB(7) to the desired range• Observe whether the end-point problem is serious

Cont.

• In case it is serious, we need to adjust 3 set of EJME parameters:

• Critical Amplitude(COMB(5)) and • Critical correlation(COMB(4)) • The plateau function(COMB(2)) (COMB(3))

How to set those parameters

• Open ejme.m• Increase COMB(2) and decrease COMB(3) • compress the domain of plateau function• Decrease COMB(4) and COMB(5) to enhance combination• Alter COMB(6) and COMB(7) according to trial eemd• Note that COMB(2)-(5) should not be varied too much

Demonstration(L:original,R:Modified)

An Intuitive example

Full Example

• Noised time series that has • a trend term, • two sinusoidal components• a white noise term

FFT Spectrum

• 2 peaks• We extract f=1.5 first

End-Point Problem

• End point problem is a nuisance at the right end• DMP has 1 less peak than

expected

2nd Extraction

• Pick f=3.5

End point problem

• For this mode end-point problem is even more rampant.• Phase is slightly distorted

EEMD modes

Target EEMD modes

p

An Intuitive example(Revisited)

EJME Result

Comparison

• IMF3 looks a lot better• slight improvement on IMF2• This demonstrates how to save

DMP from end-point problem