• Publications
  • Influence
Inferring a Tree from Lowest Common Ancestors with an Application to the Optimization of Relational Expressions
We present an algorithm for constructing a tree to satisfy a set of lineage constraints on common ancestors. We then apply this algorithm to synthesize a relational algebra expression from a simple
Data compression via textual substitution
TLDR
A general model for data compression which includes most data compression systems in the fiterature as special cases is presented and trade-offs between different varieties of macro schemes, exact lower bounds on the amount of compression obtainable, and the complexity of encoding and decoding are discussed.
A fast algorithm for computing longest common subsequences
TLDR
An algorithm for finding the longest common subsequence of two sequences of length n which has a running time of O((r + n) log n), where r is the total number of ordered pairs of positions at which the two sequences match.
Computing optimal clock schedules
  • T. G. Szymanski
  • Physics
    [] Proceedings 29th ACM/IEEE Design Automation…
  • 1 July 1992
TLDR
The author considers the problem of optimizing the parameters of a multiphase clock for a circuit containing both edge-triggered flip-flops and level-sensitive latches, and proposes an alternative method in which LP constraints are generated selectively, thus allowing fast solution.
Verifying clock schedules
TLDR
A simple polynomial time algorithm for clock schedule verification is exhibited and was implemented and used to check the timing of all the circuits in the ISCAS-89 benchmark suite.
Dogleg Channel Routing is NP-Complete
  • T. G. Szymanski
  • Computer Science
    IEEE Transactions on Computer-Aided Design of…
  • 1985
TLDR
It is shown that an efficient optimal algorithm for interconnecting two rows of points across an intervening channel is unlikely to exist by establishing that this problem is NP-complete.
Noncanonical Extensions of Bottom-Up Parsing Techniques
TLDR
A general bottom-up parsing model is presented which yields a common decision procedure for testing membership in many of the existing and extended classes which operates on larger classes of grammars and languages than the original technique.
The Complexity of Finding Cycles in Periodic Functions
TLDR
This paper shows that n(1 + \Theta (1/\sqrt M )) steps are both necessary and sufficient, if M memory cells are available to store values of the function, and explicitly considers the performance of the algorithm as a function of the amount of memory available and the relative cost of evaluating f and comparing sequence elements for equality.
The macro model for data compression (Extended Abstract)
TLDR
A general model for data compression is presented which includes most data compression systems in the literature as special cases as well as how the work of other authors (such as Lempel-Ziv) relates to this model.
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