Graph theory, which is intimately related to many branches of mathematics, has long been recognized as a powerful tool in the understanding and solution of problems that arise in many fields of science and engineering. My main research interest is the application of graph theory in various areas of computer science and engineering. These areas include computer networks, algorithm design, and fault-tolerant computing. My usual practice has been to start with an open problem in these areas and to figure out a graph-theoretic approach for its solution. Many problems have been solved this way, and many are awaiting talented and hard-working graduate students.