Towards Automatic Spatial Verification of Sensor Placement
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Transcript of Towards Automatic Spatial Verification of Sensor Placement
Towards Automatic Spatial Verification of Sensor Placement
Dezhi Hong * +
Jorge Ortiz +
Kamin Whitehouse * ^
David Culler +
*University of Virginia+UC Berkeley
^ Microsoft Research
Evolution of Buildings
Evolution of Buildings
Hypothesis
The physical boundary between roomsis detectable
as a statistical boundary in the data.
Challenge
Temp from different rooms Humidity/CO2 from same room
ApproachTemp from different rooms Humidity/CO2 from same room
ApproachTemp from different rooms Humidity/CO2 from same room
• 5 rooms, 3 sensors/room• Sensor type: temperature, humidity, CO2
• Over a one-month period
Data Set
CDFIn the same room
In different rooms!
correlation coefficient correlation coefficient
Inter/Intra Correlation
Mid band correlation Raw data traces
Threshold Analysis
Convergence
14/15 correct = 93.3%
*A-B-C-D-E is used to denote the ground truth location of sensors
Clustering
Mid-band Frequencies
12/15 correct = 80%
Raw data traces
8/15 correct = 53.3%
Clustering
Future Work
• Extended from 5 rooms to ~100 rooms– It didn’t work
• Open questions: – What new techniques can improve results?– What is the boundary that can be found?
Related Work
• Strip, Bind, Search - IPSN’13– Fontugne, et al
• Smart Blueprints - Pervasive’12– Lu, et al
• SMART - Ubicomp’12– Kapitanova, et al
• Wireless Snooping Attack – UbiComp’08– Srinivasan, et al
Summary
• A statistical boundary emerges in the early study on a small data set
• The method may be empirically generalizable• Extensions and modifications to the solution
are needed to verify the generalizability
Questions?
Thank You
Well…
• The early promising results from a small data set are not conclusive due to– Location of the room– Usage of the room– # of rooms
Questions@a large scale
• “Noise” from the same type of sensors– Same type of sensors correlate highly
Humidity Temperature
Room ID Room ID
Corrcoef across rooms
*Both the X and Y axes are arranged by room ID in the same order