PARAFAC Abnormality solution
PARAFAC Analysis results from Stephen et al., 2016 (STE) ![](image/PARAFAC_EEM_Correction/Stephen 2016 STE.jpg) PARAFAC Analysis results from Zhou et al., 2016 (JGLR) ![](image/PARAFAC_EEM_Correction/Xu 2016 WR.jpg) PARAFAC Analysis results from Xu and Guo., 2016 (WR) ![](image/PARAFAC_EEM_Correction/Zhou 2016 JGLR.jpg)
Abnormality: abrupt decline of some peaks
Compared with literatures
Walker et al. 2013
![](image/PARAFAC_EEM_Correction/Walker et al. 2013.jpg)
Stedmon & Markager 2005
![](image/PARAFAC_EEM_Correction/Stedmon&Markager 2005.jpg)
Stedmon et al 2003
![](image/PARAFAC_EEM_Correction/Stedmon et al 2003.jpg)
Hypothesis: Cut EEMs improperly
FirstOrderCut = [-40 15];
SecondOrderCut = [-40 15];
InsertedData = [NaN 0];
for i = 1:2
if FirstOrderCut(i) ~= NaN
for j = 1: length(Ex)
k = find (Em<Ex(j)-FirstOrderCut(i));
X(:,k,j) = InsertedData(i);
end
end
if SecondOrderCut (i) ~= NaN
for j = 1:length(Ex)
k = find (Em>Ex(j)*2.05+SecondOrderCut(i));
X(:,k,j) = InsertedData(i);
end
end
end
Demostration:
Solution:
InsertedData = [NaN NaN]
Results:
Introduction of samples
Samples:
Yukon River downstream
Sampling time:
2004-2005
Sample categories:
colloidal organic matter (>1kDa), low molecular weight organic matter (<1kDa), dissolved organic matter (<0.45e-6 m)
Before program revised:
3 components decomposed by PARAFAC program:
4 components from PARAFAC:
After revised:
3 components decomposed by PARAFAC program:
4 components from PARAFAC:
Comparison
Component | before program revised | After revised | ||
---|---|---|---|---|
Excitation (nm) | Emission (nm) | Excitation (nm) | Emission (nm) | |
3Components | ||||
C1 | 280 | 485 | 260 | 480 |
C2 | 250 | 480 | 250 | 420 |
C3 | 220 | 405 | <250 | 330 |
4Components | ||||
C1 | 230 | 450 | 250 | 420 |
C2 | 310 | 410 | 270 | 500 |
C3 | 385 | 480 | 260/375 | 480 |
C4 | <220 | 380 | <250 | 330 |