Introduction to Complex Networks

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Performance Monitoring in Supermarket
Refrigeration Systems---Dynamic Measure of
Synchronization in Display CasesLiang
ChenwithRafael Wisniewski, Lars F. S. Larsen,
Roozbeh Izadi-Zamanabadi, Torben Green
Refrigeration Air Conditioning, Danfoss A/S,
DenmarkEmail lchen.dhu_at_gmail.com2009-02-19
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Layout of the supermarket refrigeration system
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Dynamic Analysis Bifurcation Theory
Phase Plot
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Bifurcation Diagram
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The Suction Pressure in Synchronization Chaos
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Dynamic measure of synchronization --- the Max.
Lyapunov Exponent
For a n-dim. continuous system
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Methods for Calculation of MLE

• Model-based method
• Smooth system
• Non-smooth system
• Data-based method
• In our case
• Four sub-systems (two display cases)
• Piecewise-smooth affine system
• Practical application future extension

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Calculation Steps From Small Data Sets

• 1. Reconstruct the phase plot
• For N-point time series
• 2. Calculate Lyapunov points TISEAN
• 3. Estimate the MLE
• Least squares fit

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Bifurcation
Max. Lyap. Exp.
After Filtering
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Thanks For Your Attention !