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This paper discusses the hidden-surface problem from tile point of view of sorting. The various surfaces of an object to be shown in hidden-surface or hidden-line form must be sorted to find out which ones are visible at various places on the screen. Surfaces may be sorted by lateral position in the picture (X I'), by depth (Z), or by other criteria. The paper shows that the order of sorting and the types of sorting used form differences among the existing hidden-surface algorithms. To reduce the work of sorting, each algorithm capitalizes on some coherence property of the objects represented. ‘Scan-line coherence,’ the fact that one TV scan line of output is likely to be nearly the same as the previous TV scan line, is one commonly used kind of coherence. ‘Frame coherence,’ the fact that the entire picture does not change very much between successive frames of a motion picture can be very helpful if it is applicable. By systematically looking for additional kinds of coherence and untried sorting orders and sorting types, the paper is able to suggest two promising new approaches to the hidden-surface problem. The first, a combination of three existing algorithms, is promising because it would capitalize on both frame and scan-line coherence. The second new approach would sort in the order Y, Z, X, … the only sorting order for which an existing algorithm could not be found. [ABSTRACT FROM AUTHOR]

In sequencing problems, one of the major assumptions made is that labor is available to operate each of the machines in the shop. In many real-life situations, this assumption is not realistic; labor usually acts as a limiting resource, together with the machines. In this paper we discuss the sequencing of jobs on two machines in parallel when only a single server is available and a finite switching time is incurred to move the server from one machine to the other, and describe an algorithm to solve this problem. [ABSTRACT FROM AUTHOR]

The article focuses on the computer and the analysis of myths. The human mind can explore its own workings as revealed in two of its more powerful manifestations, namely, the myth and the computer, in each of which it is possible to detect echoes of the other. According to E.B. Tylor, sociologist, among those opinions which are produced by a little knowledge, to be dispelled by a little more, is the belief in an almost boundless creative power of the human imagination. The treatment of similar myths from different regions, by arranging them in large compared groups, makes it possible to trace in mythology the operation of imaginative processes recurring with the evident regularity of mental law, and thus stories of which a single instance would have been a mere isolated curiosity, take their place among well-marked and consistent structures of the human mind. Tylor wrote these lines a hundred years ago. No instrument lends itself better, in principle at any rate, to this sort of rigorous intellectual self-contemplation than the computer. The general purpose of the paper is to study the contribution of data-processing in the study of mythology. The construction of algorithms in mythological studies is a complicated business, but computers can do it with ease. The computer is eminently capable of exploring operative ambiguity.

This paper describes the evolution of language features for multiprogramming from event queues and semaphores to critical regions and monitors. It suggests that the choice of language concepts should be guided by two simple principles: First, it should be possible to understand a concurrent program in time- independent terms by an effort proportional to its size; secondly, it should be possible to state assumptions about invariant relationships among program components and have these assumptions checked automatically. The central problems of multiprogramming are illustrated by annotated algorithms written in a well-structured programming language. [ABSTRACT FROM AUTHOR]

The process of designing the tool layout for a single spindle multi-station automatic chucking lathe has been analysed and formulated as a set of algorithms which enable the process to be performed automatically on a digital computer. A simple, cheap and natural means of communication between the design office and the computer has been designed, and the computer output has been arranged to convey the resulting information clearly by means of layout drawings for each station and of tabulated operating data. The procedures developed should be of great value to machine tool manufacturers, particularly at the quotation stage, and to companies possessing such machines. [ABSTRACT FROM AUTHOR]

We consider the problem of selecting an optimal traffic network in its simplest form, where there are no congestion costs. The superadditive effect of deleted links on the objective function is pointed out and used to develop some implicit enumeration procedures for this problem. Some efforts are devoted to evaluate these algorithms, and to show how to stop the computations with an "acceptable" approximate solution when computations are taking too much time. [ABSTRACT FROM AUTHOR]

A branch and bound algorithm for solution of the "knapsack problem," max Σ v[sub i],x[sub i] where Σ w[sub i]x[sub i] ≤ W and x[sub i] = 0, 1, is presented which can obtain either optimal or approximate solutions. Some characteristics of the algorithm are discussed and computational experience is present. Problems involving 50 items from which approximately 25 items were loaded were solved in an average of 0.07 minutes each by a coded version of this algorithm for the IBM 7094 computer. [ABSTRACT FROM AUTHOR]