Research Interests

• Algorithms

• Distributed and Parallel Computing

• Autonomous Robot Coordination

• Reconfiguable Computing

• Interconnection Networks

• Education Research
  
  My research spans several areas centered on parallel and distributed computing.
  
  One major focus of the research has been reconfigurable computing, particularly reconfigurable models and algorithms. We have proposed an important model, the Reconfigurable Multiple Bus Machine (RMBM), that reveals the relative powers of segmenting and fusing buses. We used this to place reconfigurable models in a hierarchy of computing powers relative to other reconfigurable models and classical models of computation. Another significant direction of our work has been in identifying model and algorithmic features that affect the scalability of reconfigurable models. Our book "Dynamic Reconfiguration: Architectures and Algorithms" is a brings together, in one unified framework, the wide range of models, techniques and algorithms proposed during a decade of research in the area.
  
  A recent focus has been on reconfigurable hardware and architectures that facilitate fast partial reconfiguration of devices such as FPGAs. With increased interest in the use of reconfigurable fabrics as integrated accelerators, this direction of research is important. We have designed a method that can efficiently select a subset of frames to reconfigure and rapidly route the configuration bits to the selected frames. Specifically, we have constructed a that simultaneously enables multiple elements and automatically forms a scan-path through them (for sending in configuration bits, if the selected elements are frames to be reconfigured). This work could have application beyond partial reconfiguration, for example in simultaneous access to multiple (independent) memory locations. It may also be useful for matching optical and electrical bandwidths by serializing multiple pieces of data to a single optical waveguide). This approach could lead to a big improvement over conventional methods that select one element (frame or memory location) at a time (for reconfiguration or for access). This work has been patented.
  
  In another work on reconfigurable architectures, we have proposed the idea of combining branching programs (that represent solutions on bus-based reconfigurable models) and Boolean gates to generate faster circuits. If this work can be generalized, then it could bring advantages of theoretical reconfigurable models to practical circuits.
  
  Another major thrust of the research involves various aspects of distributed computing. One direction in this thrust is the study of coordination problems for swarms of mobile autonomous robots. In particular, we have examined the problem of arranging the robots in positions that make all robots visible to each other; this "Complete Visibility" problem is a fundamental one that leads to solutions to other coordination problems. A key result we proved is that Complete Visibility can be achieved in constant time (independent of the number of robots in the swarm). This result is significant in itself, but perhaps more importantly, our work has introduced the idea of time as a performance metric; previous approaches for oblivious autonomous robots only guaranteed algorithm completion in finite time.
  
  Another direction is to use information-theoretic approaches in distributed computing. For instance, we derived message and time bounds on the well-studied problem of scheduling access to a shared channel. Our approach showed a marked improvement over conventional "group-testing" based approaces. The main intuition to our result was an observation that it is not necessary to identify all competitors for the shared channel (as many current solutions do); just distinguishing them suffices. This approach brings a fresh perspective to a well-studied, but important, problem.
  
  We are also working on distributed optical mutual exclusion and distributed algorithms for load balancing on an electrical grid. This work is at a more nascent stage. Our work is also in other areas including computational geometry and multiple bus-based interconnection networks.
  
  My current work aslo involves pedagogical research. Recently we received an NSF grant through which we organized the "Workshop on Connecting Concepts Across the Curriculum" that brought together faculty from across the USA and Canada . The key contribution of the workshop and subsequent study was to produce a useful template for reinforcing foundational concepts across a sequence of courses. We are currently looking to implement some of these ideas in our own curriculum. A recent book chapter details some initial work in this direction.
  
  I have also served as the program chair for the NSF/IEEE-TCPP Workshop on Parallel and Distributed Computing Education (EduPar), 2016. I am a lead member of a multi-university team to update the NSF/IEEE-TCPP Curriculum Guideline for Parallel and Distributed Computing (PDC) in Undergraduate Education. NSF has recently funded this activity. We believe that this is very important for Computer Engineering and Science education, as parallel and distributed systems are everywhere in modern computing platforms, whereas coverage of these topics has lagged in most modern undergraduate curricula.

R. Vaidyanathan
Elaine T. and Donald C. Delaune Distinguished Professor
School of Electrical Engineering and Computer Science
Louisiana State University
Baton Rouge, LA 70803-5901

Phone: (225) 578-5238
Fax: (225) 578-5200
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