September 1978 - Vol. 21 No. 9
Features
An algorithm using symbolic techniques for the Bel-Petrov classification of gravitational fields
In this note, an algorithm is presented for the symbolic calculation of certain algebraic invariants of the Weyl tensor which permits the determination of the Bel-Petrov…
Hybrid simulation models of computer systems
This paper describes the structure and operation of a hybrid simulation model in which both discrete-event simulation and analytic techniques are combined to produce…
A practical interprocedural data flow analysis algorithm
A new interprocedural data flow analysis algorithm is presented and analyzed. The algorithm associates with each procedure in a program information about which variables…
A model for verification of data security in operating systems
Program verification applied to kernel architectures forms a promising method for providing uncircumventably secure, shared computer systems. A precise definition of data…
Generalized working sets for segment reference strings
The working-set concept is extended for programs that reference segments of different sizes. The generalized working-set policy (GWS) keeps as its resident set those…
A controlled experiment in program testing and code walkthroughs/inspections
This paper describes an experiment in program testing, employing 59 highly experienced data processing professionals using seven methods to test a small PL/I program. The…
Insertion and deletion algorithms are provided for the class of right (or one-sided) brother trees which have O (log n) performance. The importance of these results stems…
Event manipulation for discrete simulations requiring large numbers of events
The event-manipulation system presented here consists of two major parts. The first part addresses the familiar problem of event scheduling efficiency when the number of…
A note on virtual memory indexes
In [4] Maruyama and Smith analyzed design alternatives for virtual memory indexes. The indexes investigated were those modeled on the structure of VSAM [5] which are…
Simulations of dynamic sequential search algorithms
In [3], R.L. Rivest presents a set of methods for dynamically reordering a sequential list containing N records in order to increase search efficiency. The method Ai (for…