Pervasive Computing 研究群 研究能量與研發成果

1. Pervasive Computing研究群研究能量與研發成果

2. Members and Research Directions • Sensor networks • 曾煜棋、王國禎、黃俊龍 • WLAN • 曾煜棋、王國禎 • Mesh networks • 曾煜棋、王國禎 • Mobile peer-to-peer service grid • 邵家健、彭文志 • Ubiquitous sensor/actuator infrastructure • 邵家健 • Sensor data management and mining • 彭文志、黃俊龍

3. 研發成果

4. A Cluster-based Energy Efficient Routing Algorithm in Mobile Wireless Sensor Networks Step 1. Select one hop neighbor nodes closer to the anchor Energy consumption vs. number of nodes Step 2. Choose the node with the maximum energy level from the selected nodes Latency per packet vs. number of nodes.

5. A Deferred-Workload-based Dynamic Voltage Scaling Algorithm for Hard Real-Time Systems An illustration of dwDVS Effect of WCET/BCET ratio on energy consumption Effect of worst-case utilization on energy consumption

6. A Power Saving MAC Mechanism for VoIP over IEEE 802.11e WLANs VoIP over WLANs system architecture Power saving mechanism in PSM-V

7. A Power-Efficient MAC Protocol for VoIP Traffic over IEEE 802.11e WLANs QSTA 1 QSTA 1 QSTA 2 QSTA 2 ….. PIFS QAP SIFS SIFS SIFS SIFS PIFS .... QoS CF-Poll ACK .... .... Beacon Beacon QoS Null Data QSTA TXOP 1 CAP Controlled Access Phase (CAP) Contention Period (CP) Proposed power-efficient polling scheme Polling scheme comparison

8. Emergency Guiding System by Wireless Sensor Networks Emergency Guiding Scheme Tree Reconstruction • Water toward low spot • Hazardous regions • Distributed adjust weight to find escape path • Support reliable reporting scheme, when emergencies occur • Dynamically recover the failure links • Low cost and quick convergence Monitoring Guidance Interface Protocol Stack

9. Stargate WLAN card Static sensor WebCam Mobile sensor Lego car The Deployment and Dispatch Issues of Mobile Wireless Sensor Networks Indoor Sensor Deployment k-covered Sensor Deployment • Characteristics • - Arbitrary-shaped obstacles in the field • - Arbitrary relationships of rc and rs • - Fewer sensors required for deployment • - Sensor dispatch to reduce deployment cost • >> Max-weight max-match problem • Characteristics • - Deployment for multi- level coverage WSN • - Arbitrary relationships of rc and rs • - Fewer sensors required for deployment • - Distributed sensor dispatch algorithms • >> greedy-based & pattern-based schees 1 2 4 3 Multi-type Sensor Dispatch iMouse System • Characteristics • - Implementation of “mobile” sensor • - Provide WSN-based surveillance service • - Combine adv. of both WSN and traditional • surveillance systems • Problem • - How to dispatch sensors so that events • can be detected on time & total energy • consumption can be minimized All events are detected Event “a” is not detected

10. Coverage of a Wireless Sensor Network without Location Information • Goal • Determine whether the sensing region of each sensor is sufficiently covered by k other nodes without location information • Provide comparable results to the location-based algorithm

11. Location Management for Object Tracking in Wireless Sensor Networks Tree-based location management scheme that consists of (1) The update and query mechanisms (2) The tree construction algorithms Two Location Management Schemes

12. The Beacon Movement Detection Problem in Wireless Sensor Networks for Localization Applications If beacon sensors are moved by accident, the localization error will be increased seriously. • System model:

13. A Noise-Tolerant Indoor Positioning Method by Signal Scrambling • Design Guidelines: • Propose a tracking scheme to improve accuracy of various localization algorithms • Temporal dependency is used to enlarge real-time sample space • Spatial dependency is used to select a better location System Flow Viterbi-like Location Selection Module

14. Quick Convergecast in ZigBee/IEEE 802.15.4 Tree-Based Wireless Sensor Networks Problem formulation • Convergecast is a fundamental operation in wireless sensor networks • This paper defines a minimum delay beacon scheduling problemfor quick convergecast in ZigBee/IEEE 802.15.4 tree-based wireless sensor networks • We prove that this problem is NP-complete. Current results • Our formulation is compliant with the low-power design of IEEE 802.15.4. • We propose • Optimal solutions for special cases • Heuristic algorithms for general cases • Simulation results show that the proposed algorithms can indeed achieve quick convergecast

15. Energy Efficient Algorithms for Mobile Sensors • Sensor dispatching problem in collaborative network Mobile sensors achieve advanced detection Static sensors detect the event • Impact of load balancing Remaining sensors bear heavier load This sensor is dead!

16. Exploiting Data Coverage for Approximate Query Processing in Wireless Sensor Networks • Data Coverage • Sensors with correlated readings are clustered together. • We pick a representative out from each cluster. • The representatives will answer queries; the other sensors only sense the environment and do not respond. • Data-Covering Problem Input: set of sensors S, clustering criteria ε Output: set of representatives R Constraint: minimize the size of R while keeping every sensor is clustered.

17. Traitor o x x o o v.s. x x Patriot o Stable No cheat Unstable cheated Traitor Filtering Faulty Readings to Improve Data Accuracy in Sensor Networks • Byzantine Problem (trust degree is equal)

18. Hybrid Program Verification for AFSM Based Sensory-Motor Control • Use Binary Decision Diagram (BDD) verification technique (for program) to check automatic robot behaviors • Based on Rodney Brooks’ Augmented FSM(AFSM) model • Described by UNITY specification language • Can be verified by BDD-based model checker • Verify obstacle avoidance behaviors of roving robot Cleaning Crew Interacting AFSM Modules Transform Experiment from continuous domain to discrete domain

19. Resilient Application Layer Multicast Tailored for dynamic Peers with Asymmetric Connectivity • Application Layer Multicast (ALM) • Minimize and equalize transport latency to all peers • Dynamic Peer Behaviors • Unpredictable join/leave • Asymmetric connectivity • Limited upstream bandwidth Multiple Multicast Trees Application layer Multicast System Demand of Helper

20. Major Projects • ZyXEL Inc.: “802.11e無線網路下的傳輸品質與快速換手之研究 (QoS and Fast Handover in 802.11e WLAN)”, 2005.03-2006.02. • 工研院/學研計畫: "Communication Protocols for Wireless Access Networks". (2005.01~2005.12) • 後卓越計劃(Program for Promoting Academic Excellence of Universities II), NSC: "Advanced Technologies and Applications for Next Generation Information Networks" 下一世代資訊通訊網路尖端技術與應用(2004.04~2008.03). • 分項計畫三: B3G All-IP Wireless Network Technologies, 後三代全IP無線網路技術 • 分項計畫四: Wireless Ad Hoc and Sensor Networks Technologies, 無線隨意及感測網路技術 • 國科會: “藍芽個人無線區域網路上通訊議題之設計實作與分析”(2003.08~2006.07) • 無線感測網路之動態定位技術, National Science Council, August 1, 2004 - July 31, 2007

21. Areas of research interests Wireless networks and mobile Computing Sensor networks, ad-hoc networks, and mesh networks Power-aware computing and communications Network reliability and security Publications Journal papers: 22 Conference papers: 47 Book Chapters: 1 B.S., NCTU-Control Eng., 1978 M.S., Univ. of Arizona-ECE, 1986 Ph.D., Univ. of Arizona-ECE, 1991 Senior Engineers, Directorate General of Telecommunications, 1980-1984 Professor, NCTU-CS, 1999 ~ Research projects NCTU-MediaTek Project: Low power, handover and QoS schemes in heterogeneous wireless networks NSC Project: Dynamic localization in wireless sensor networks Prof. Kuochen Wang (王國禎教授)

22. Areas of research interests Wireless Network Communication Protocol Mobile Computing Network Security Wireless Sensor Network Wireless Mesh Network Wireless VoIP Distributed System Parallel Processing Publications International journal: 91 International conference: 99 Book Chapters: 12 Patents: 2 granted, 5 pending B.S., NTU-CSIE, 1985 M.S., NTHU-CSIE, 1987 Ph.D., Ohio State University-CIS, 1994 Professor, NCTU-CS, 2000~ Chief Executive Officer, ITRI-NCTU Joint Research Center, 2005~ Chairman, NCTU-CS, 2005~ “Distinguished Alumnus Award”, 2005, The Ohio State University Distinguished Research Award (two times) Distinguished EE Professor Award, The Chinese EE Institute, 2005 Prof. Yu-Chee Tseng (曾煜棋教授)

23. Prof. Wen-Chih Peng(彭文志教授) • B.S., NCTU-CSIE, 1995 • M.S., NTHU-CSIE, 1997 • Ph.D., NTU-EE, 2001 • Assistant Professor, NCTU-CS, 2003/8~ • A member of the IEEE • Research interests • Data management and mining in sensor networks • Mobile data management • Data mining/databases • Publications • International journal: 8 • International conference: 14 • Email: wcpeng@cs.nctu.edu.tw

24. Associate Professor, NCTU, 2005– Ph.D., NTU EE, 2003 M.S., NCTU CSIE, 1999 B.S., NCTU CSIE, 1993 Research interests Mobile data management Dependent data broadcast On-demand data broadcast Mobile Internet Cache relocation Transcoding proxy Sensor network Publications Journal papers: 5 Conference papers: 17 Email: jlhuang@cs.nctu.edu.tw Prof. Jiun-Long Huang (黃俊龍教授)

25. Research interests Pervasive Sensor-Actuator Systems Autonomous Sensor/Actuator Assembly Model-based Software Specification & Implementation Operational/Functional Component Coordination Infrastructure-less (P2P) Service Security P2P Security Policy Management P2P Service Security Enforcement Publications Journal Papers : 2 Conference Papers : 7 Internet Draft : 3 Patents : 2 Email: jkzao@cs.nctu.edu.tw Associate Professor (NCTU), 2004 – Ph.D. (Harvard), 1995 Senior Member, IEEE, 2001 Senior MTS (BBN), 1994–2002 Principal MTS (BBN), 2002–2003 Chairman, Security Policy Task Force, DARPA Information Assurance (IA) Program, 1999–2000 Member, US Army Task Force XXI Tactical Internet Gray-beard Panel, 1996–1997 Co-founder, SecurKey Inc. (Canada), 1987–1990 Prof. John K. Zao (邵家健教授)