My current research interests lie in the following areas:

• Autonomic (self-managing) computing systems. Design of self-managing distributed computer systems that aim to maintain a designer-specified quality-of-service by adaptively tuning key operating parameters with minimal human intervention.


• Model-based design of embedded systems. Develop model-based  design and analysis technique for component-based distributed real-time embedded systems. 


• Formal verification of distributed real-time systems. Developing formal models and techniques to verify key Quality of Service (QoS) properties in real-time systems such as end-to-end deadlines and latencies.


• System diagnosis and diagnosability analysis. Design quantitative fault models and diagnosis reasoning algorithms and tools targeting sensor-monitored engineering systems.


• Model-integrated computing. Formal representation, composition, analysis, and manipulation of models during the design process. The technology provides an open integration framework to support formal analysis tools, verification techniques, automated synthesis, and model transformations in the development process.

Recent research projects include:

• Fault-adaptive control technology (FACT). A Toolsuit for integrated performance and health management of embedded systems. The project aimed at developing fault-adaptive control systems that integrate control and system-level fault diagnosis. The primary focus is on developing modeling approaches and real-time, embeddable fault-diagnostics algorithms that could be used in the model-driven development of system health management applications. The project was initially supported by DARPA and currently it is supported by the aerospace industry.


• Model-based diagnosis using time failure propagation graphs. A  real-time model-based diagnosis system based on the timed failure propagation graph (TFPG) model. The TFPG model captures the temporal progression of effects that are caused by failure modes. The developed diagnosis algorithm handles multiple faults as well as potential sensor failures and degrades gracefully as the number of failures increases. The TFPG tool is currently being tested by a major avionic company for implementation on future aircrafts. 


• Distributed real-time embedded analysis method (Dream). An open-source project aimed to automatically generate formal models from the design specification of embedded systems. T The developed tool enables design-time analysis of timed properties, and can effectively be applied to compose, predict, and verify the event-driven behavior of component-based DRE systems. This tool has been applied to verify correctness and dependability aspects of the Boeing Bold Stroke architecture, which is being used in a variety of mission-critical avionics applications on a component middleware platform that has been developed using Real-time CORBA.


• Adaptive performance management of computing systems. This project aims to develop the theoretical foundation and demonstrate technologies for model-driven engineering of self-managing distributed computing systems. A lookahead control policy is developed for managing the performance and resource requirement of a wide class of computation systems operating in uncertain environment. The developed performance management structure has been applied to several real-life systems including the fuel-tank system of an aircraft, the water recovery system in the NASA advanced life support system, a signal detection and classification system, and a multi-tier e-commerce application.

• Boeing: Fault Adaptive Control Technology Maintenance, (PI), Jan. 2007 - Dec. 2008.


• NSF: Design for Adaptivity and Reliable Operation of Software Intensive systems, (PI), Sept. 2006 -- Aug. 2009.


• NSF: Dynamic Modeling, Analysis, and Synthesis of Embedded Hybrid Systems, (Co-PI), Sept. 2002 - Aug. 2005.


• NASA: Distributed Monitoring and control of complex dynamic systems, (Co-PI), Jan. 2003 - Dec. 2005.


• NSF: Distributed Diagnosis for Safety of Complex Hybrid Systems, (Co-PI), Sept. 2004 - Aug. 2006.