1. Pervasive Data Access (PDA) Research Group
Mei Li
Pennsylvania State University

2. Overview
Investigate various research issues involving data access and management in a wide spectrum of pervasive/mobile computing and networking environments
peer-to-peer networks
mobile ad-hoc networks
wireless sensor networks
Also investigate object-oriented databases, XML, security, and information integration and retrieval 2
9/17/2018

3. Peer-to-Peer (P2P) Systems
Peer-to-Peer computing paradigm has changed the ways large-scale distributed systems are built and operated.
Goal of our research
design data management systems to support various applications ranging from distributed research locating to network attack detection
We Investigate
Information management infrastructure
Complex queries processing
Knowledge discovery (clustering, outlier detection)
We address various system issues
overlay maintenance, load balancing, resilient to dynamic changes, adaptivity to query locality 3
9/17/2018

4. Location-aware Wireless Sensor Networks (WSNs)
WSNs have a wide range of applications
object tracking, environmental monitoring, warehouse inventory, and health care.
Goal of our research
build data management systems in support of data collection, aggregation, dissemination, in-network query processing and query optimization.
We investigate
location tracking of moving objects
location-based routing
complex query processing (window, KNN, and aggregation queries)
Spatio-temporal modeling and estimation of wireless link quality in sensor networks 4
9/17/2018

5. Mobile and Pervasive Data Access
Important for a wide range of mobile businesses and applications.
We are one of the first few pioneers who started research in this area
Indexing
Caching
Accessing
Data aggregation
Data dissemination
Channel allocation
Query processing
Our work has extensive coverage
from simple data to spatial data
from single cell to multiple cells
from stationery clients to moving clients 5
9/17/2018

6. Location-Based Services (LBSs)
LBS is one of the killer applications for mobile computing and wireless data services.
We investigate
indexing and caching spatial data to support the processing of location based spatial queries (LBSQs)
point query, window query, k nearest neighbor (KNN) search, continuous nearest neighbor (CNN) search, spatial join, and other complex spatial queries
We address various issues
large index search space, large index size, linear streaming property of wireless data broadcast, continuous movement and requests of mobile users, and cache replacement/invalidation 6
9/17/2018

7. Contact Information
Dr. Wang-Chien Lee
Mei Li 7
9/17/2018