Normalization research has concentrated on defining normal forms for database schemas and developing efficient algorithms for attaining these normal forms. It has never been proved that normal forms are good, i.e. that normal forms are beneficial to database users. This paper considers one of the…
A file server is a utility provided in a computer connected via a local communications network to a number of other computer. File servers exist to preserve material for the benefit of client machines or systems. It is desirable for a file server to be…
Semantic integrity assertions are predicates that define consistent database states. To enforce such assertions, a database system must prevent any update from mapping a consistent state to an inconsistent one. In this paper, we describe an enforcement method that is efficient for a large class…
A description is given of the design goals, microarchitecture, and implementation of the microprogrammed processor for a compact high performance personal computer. This computer supports a range of high level language environments and high bandwidth I/O devices. Besides the processor, it has a cache, a…
The first order topology and the full second order logic are interpretable each in the other. The monadic topological theory of the Euclidean plane and the full second order theory of 2nd are interpretable each in the other.
Before this paper, it was generally assumed that a three-processor system could tolerate one faulty processor. This paper shows that "Byzantine" faults, in which a faulty processor sends inconsistent information to the other processors, can defeat any traditional three-processor algorithm. (The term Byzantine didn't appear…
The sound modes of He II in a waveguide partially packed with superleak are investigated for the case of a free surface within the waveguide. In the limit of zero vapor density, two propagating modes are found: one a gravity wave whose velocity depends on…
This paper presents three scan line methods for drawing pictures of parametrically defined surfaces. A scan line algorithm is characterized by the order in which it generates the picture element of the image. These are generated left to right, top to bottom in the much…
After graduating from Cornell, Susan Owicki joined the faculty of Stanford. Some time around 1978, she organized a seminar to study the temporal logic that Amir Pnueli had recently introduced to computer science. I was sure that temporal logic was some kind of abstract nonsense…
Sound propagation has been studied in He II films adsorbed on alumina powder grains (Al2O3). Sound velocity and adsorption isotherm data provide evidence that surf ace tension forces can exceed the van der Waals forces as the film thickness increases. A model of capillary condensation…
The file system and modularization of a single-user operating system are described. The main points of interest are the openness of the system, which establishes no sharp boundary between itself and the user’s programs, and the techniques used to make the system robust.
Isolating with four analog switches the frequency-determining portion of the circuit from that controlling the charging and discharging of its RC integrator, this ramp generator achieves independent selection of slope ratio and repetition rate. Such a unit is useful in a music synthesizer, where timbre…
