Research

My research interest lies in the area of embedded real-time and distributed systems. Specifically, my work has focused on the design of large-scale distributed embedded real-time systems.

Embedded computers have become more pervasive and complex nowadays. Every microwave oven has one. The Volvo S80 has more than fifty. A Boeing 777-300 has hundreds. Meanwhile, more and more embedded systems are inter-connected to perform sophisticated functions on their hosts such as the air information management systems on modern aircrafts. However, due to real-time and fault-tolerance concerns, embedded systems are traditionally implemented on dedicated hardware. This approach entails at least three serious consequences: firstly, profligate and rigid usage of resources necessitated by the binding of subsystems to hardware platforms; secondly, significantly more difficult system integration because individually developed and tested systems are not guaranteed to work in combination; thirdly, the lack of higher-level system control because conceptually indivisible functions are isolated on the hardware level. These problems have caused not only financial loss such as unusable systems due to the high cost of unjustified resource redundancy and integration failures, but also the loss of human lives as exemplified by a number of fatal accidents induced by the third problem. It is critical that system engineers have a solid basis for addressing these fundamental design problems in large-scale real-time embedded systems. 

Towards this end, I introduced the Real-Time Virtual Resource architecture in my dissertation. Real-Time Virtual Resources (RTVRs) virtualize various types of resources by characterizing their temporal behavior and providing application isolation for fault tolerance. Physical resources can be aggregated and assigned on demand to provide execution platforms for dynamic real-time applications while respecting the timeliness properties of these applications. At the same time, fault tolerance capabilities are also considerably enhanced. With RTVR, each application can be designed as if the resources that it accesses were dedicated to that application. This separation of concerns can greatly facilitate system engineering through the design, the development to the integration of the system. Together with the property of compositionality, these features allow us to effectively tackle the problems described earlier and qualify RTVR as suitable for large-scale systems. As shown in my dissertation, applications using heterogeneous resources in a distributed or parallel environment can be efficiently constructed.

Publications