Physical Sciences and Mathematics Commons^™

Epsilon Precedence Grammars And Languages, Masoud T. Milani

Retrospective Theses and Dissertations

The classes of simple and weak precedence grammars are generalized to include ε-rules (productions with the empty right parts). The descriptive power of epsilon simple precedence (ESP) grammars increases directly with the number of ε-rules permitted; the class of ESP grammars with no ε-rules, ESP₀, is identical to the class of simple precedence grammars; ESP grammars with at most one ε-rule, ESP₁, define a class of languages which properly includes the class of ESP₀ languages, but is itself properly included in the class of deterministic, context-free languages. In general, ESP grammars having at most i …

Intra Region Routing, Robert Alan Eustace

Retrospective Theses and Dissertations

The custom integrated circuit routing problem normally requires partitioning into rectangular routing regions. Natural partitions usually result in regions that form both "channels" and "areas". This dissertation introduces several new channel and area routing algorithms and measures their performance.

A formal description of the channel routing problem is presented and a relationship is established between the selection of intervals for each track and the number of tracks in the completed channel. This relationship is used as an analysis tool that leads to the development of two new and highly effective channel routing algorithms: the Revised and LCP algorithms. The performance …

Multiprocessor Scheduling With Practical Constraints, Kenneth Burton Donovan

Retrospective Theses and Dissertations

The problem of scheduling tasks onto multiprocessor systems has increasing practical importance as more applications are being addressed with multiprocessor systems. Actual applications and multiprocessor systems have many characteristics which become constraints to the general scheduling problem of minimizing the schedule length. These practical constraints include precedence relations and communication delays between tasks, yet few researchers have considered both these constraints when developing schedulers.

This work examines a more general multiprocessor scheduling problem, which includes these practical scheduling constraints, and develops a new scheduling heuristic using a list scheduler with dynamically computed priorities. The dynamic priority heuristic is compared against …