1. John K.S. Lau & C.K. Tham & T. Luo
E-mail: {elelksj, eletck, eleluo}@nus.edu.sg
Participatory Cyber Physical
System in Public Transport
Application
IEEE/ACM UCC’11 International Workshop of Cloud
Computing and Scientific Applications (CCSA 2011)

2. Participatory Cyber Physical System in Public Transport Application
JKS Lau, CK Tham, T Luo
Motivation
•How to enrich travel experience thereby increase
public transport ridership?
• How to obtain data if transit agencies are either
incapable or reluctant?
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3. Participatory Cyber Physical System in Public Transport Application
JKS Lau, CK Tham, T Luo
Contributions
•ContriSenseCloud
– Participatory cyber physical system.
•ContriSense:Bus
– Application on ContriSenseCloud.
– Application on Android smartphones.
•RESTful API
– Data as a service.
•NTRS and S2B algorithms
– Complements GPS trajectory database and MATE
algorithm.
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4. Participatory Cyber Physical System in Public Transport Application
JKS Lau, CK Tham, T Luo
ContriSenseCloud Architecture
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5. Participatory Cyber Physical System in Public Transport Application
JKS Lau, CK Tham, T Luo
ContriSense:Bus Architecture
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6. Participatory Cyber Physical System in Public Transport Application
JKS Lau, CK Tham, T Luo
Cyber Physical Society
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7. Participatory Cyber Physical System in Public Transport Application
JKS Lau, CK Tham, T Luo
RESTful API
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http://example.com/xchange/api/view/1
http://example.com/xchange/api/view/1/5
http://example.com/xchange/api/view/1/5/2

8. Participatory Cyber Physical System in Public Transport Application
JKS Lau, CK Tham, T Luo
NTRS and S2B Algorithms
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NTRS
GPS
Trajectory
Database
MATE
S2B
Real
World
Us
RESTful

9. Participatory Cyber Physical System in Public Transport Application
JKS Lau, CK Tham, T Luo
User-contributed Traces
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Legend
Balloon – Bus stop (node)
Red line – Actual
Green line – Mapped
NUS
D1/D2
95
190 196

10. Participatory Cyber Physical System in Public Transport Application
JKS Lau, CK Tham, T Luo
Services in ContriSense:Bus
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XML
JSON

11. Participatory Cyber Physical System in Public Transport Application
JKS Lau, CK Tham, T Luo
Performance Measurements
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Latency(s)
No. of travel time queried
Latency(s)
No. of concurrent users (queries)
No. of concurrent users (API calls)
Latency(s)
Latency(s)

12. Participatory Cyber Physical System in Public Transport Application
JKS Lau, CK Tham, T Luo
Future Works
•Integrating closed-loop incentive scheme for supply
and demand valuation.
•Improving S2B algorithm so that Kmax and Kmin are
adaptive.
•Introducing load balancing for higher scalability.
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13. Participatory Cyber Physical System in Public Transport Application
JKS Lau, CK Tham, T Luo
THANK YOU
Questions?
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