Multiprogrammering — en orientering

The need for effective utilization of computer facilities has resulted in a great interest in parallel processing of several independent programs on a computer.The introductory parts of this paper deal with multiprogramming both for batch and real-time computer systems. Also some important hardware features such as automatic program interrupts, memory lock-outs and autonomous facilities are discussed.In the following chapter elementary program-mechanics are introduced and attention is paid to priority assignment to different programs.Some main functions of a Master Control Program are then discussed and finally some aspects are given on multiprogram scheduling of computer runs.Multiprogramming is still in an early stage of its development and therefore this paper makes no claim to completeness—it rather attempts to render some important principles of these new techniques.     

Dimensionado en compresión en acero: el peso del pandeo

The verification of the slender compressed members of a structure is a well formulated and codified problem. However, the non-linearity of the design process, combined with the no linearity of the physical problem requires an iterative process to define the piece that solves a given problem. This paper demonstrates an identity relationship between seemingly different problems, based on which we develop a theoretical approach and a simple procedure to determine, without iteration and with little margin for error, the piece needed for a given problem. The paper provides a statistical model to check that the provided procedure is safe and effective in the 98% of the problems in buildings —pillars and bars from trusses—. The presented approach therefore greatly facilitates decisions in this area.     

Klystron stabilisé en phase

Summary In an earlier communication on High Resolution Microwave Spectroscopy²⁷) we described a spectrograph using a phase-stabilized klystron oscillator as a local oscillator in the detection system. The stabilizing system has a holding range of several megacycles which permits the sweeping of the reference crystal oscillator.     

Strahlensysteme im Großen

Ohne Zusammenfassung     

A Berry-Esséen Theorem for Serial Rank Statistics

Berry-Esséen bounds of the optimal O(n-1/2) order are obtained, under the null hypothesis of randomness, for serial linear rank statistics, of the form a1 (Rt)a2(Rt-k). Such statistics play an essential role in distribution-free methods for time-series analysis, where they provide nonparametric analogues to classical (Gaussian) correlogram-based methods. Berry-Esséen inequalities are established under mild conditions on the score-generating functions, allowing for normal (van der Waerden) scores. They extend to the serial case the earlier result of Does (1982, Ann. Probab., 10, 982-991) on (nonserial) linear rank statistics, and to the context of nonparametric rank-based statistics the parametric results of Taniguchi (1991, Higher Order Asymptotics for Time Series Analysis, Springer, New York) on quadratic forms of Gaussian stationary processes.     

Achtdimensionale lokalkompakte Translationsebenen mit großen kompakten Kollineationsgruppen

This paper is part of a program aiming at the classification of all higher-dimensional locally compact translation planes whose collineation groups have large dimension. In the present paper we determine all eight-dimensional locally compact translation planes which admit acompact collineation group of dimension at least 5 acting almost effectively on the translation axis. In fact, is isomorphic either to Spin₄ or toSO ₄(). The case Spin₄() has already been treated elsewhere ([6]). Here, the planes with SO ₄() are explicitly determined and studied in detail.     

Où en sont les mathématiques?

Feel like writing a review for The Mathematical Intelligencer? You are welcome to submit an unsolicited review of a book of your choice; or, if you would welcome being assigned a book to review, please write us, telling us your expertise and your predilections.     

G-invariance faible et isovariance en planification expérimentale

In this Note, we state a polynomial characterization of weakly invariant designs and show how to derive the construction of weakly invariant designs for the action of a compact group of matrices on an experimental domain, whose interior is not empty, from the construction of rotatable designs. As a consequence, it enables us to search for weakly invariant designs using techniques coming from computational commutative algebra and to benefit from the cumulated knowledge of rotatable designs which have been intensively studied since the seminal paper of Box and Hunter. To cite this article: F. Bertrand, C. R. Acad. Sci. Paris, Ser. I 347 (2009).     

Ermittlung kürzester Durchlaufzeiten auf Fertigungsstraßen

Zusammenfassung Für eine Folge von Produkttypen verschiedener Stückzahlen, die auf derselben Fertigungsstraße hergestellt werden, wird unter gegebenen Voraussetzungen die kürzeste Durchlaufzeit ermittelt unter Berücksichtigung der Überlappung der Durchlaufzeiten der einzelnen Produkttypen auf der Straße. Dies führt auf ein Reihenfolgeproblem der Typen, das sich theoretisch durch Permutieren lösen läßt. Unter den gegebenen Voraussetzungen kann die Ordnung der Permutationen um eine Stufe erniedrigt werden. Ein weiterer gleichartiger Reduktionsversuch wird auf Grund elementarer gruppentheoretischer Eigenschaften als aussichtslos aufgezeigt. Die Lösung wird durch ein dafür entwickeltes, geeignetes Verfahren zur Erzeugung von Permutationen gewonnen. Besonderer Wert ist auf eine mathematische Einkleidung des Problems gelegt worden.

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Summary The shortest duration of passage is determined, over one production line, for a given sequence of (different) types of product of differing batch numbers. This calculation is to be valid under certain operating conditions, and allows for the overlap of individual batch passages. The problem is one of type sequence and can thus be expressed in terms of permutation. Under the prevailing conditions, the order of permutation may be lowered by one degree. It is shown that another, similar attempt at a reduction would prove pointless because of the elementary properties of group theory.The solution is gained by working out for this purpose an appropriate procedure for generating permutations. Great pains were taken with the mathematical transference of the problem.

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Vorgel. v.:J. Nitsche     

Einschließen der Lösungen von Randwertaufgaben

Ohne ZusammenfassungHerrnRobert Sauer zum 60. Geburtstag am 16.9. 58 gewidmet.     

Méthodes quantiques en topologie algébrique

Using quantum methods, we introduce here the notion of “neo-algebra” which generalizes the notion of a commutative differential graded algebra. Under some mild finiteness conditions, we can associate functorially to a space a neo-algebra over the finite field F_p: its quasi-isomorphism's class determines the p-adic-homotopy type of X. As a matter of fact, from this data, we can describe in a simple way Steenrod operations in the cohomology of X, as well as the p primary part of its homotopy groups. This point of view extends to finite characteristics the well-known rational homotopy theory of D. Quillen [9] and D. Sullivan [11]. It is deeply related to previous works of P. May, I. Kriz [5] and M.A. Mandell [7], [8].     

Solutions en dualité pour les gaz sans pression

We introduce the notion of duality solution for the system of pressureless gases, which ensures existence for the Cauchy problem, and uniqueness under optimal conditions on initial data.     

Sous-Solutions de Problèmes aux Limites en Dimension 1

We consider a boundary value problem where is a maximal monotone operator in and E is a multivalued operator in ² with non decre asing resolvent. We introduce a condition on E which insures that the operator inL ¹ (0,1) associated to this problem has non decreasing resolvent, and caracterise the subsolutions of the problem. We give different examples of operatorsE satisfying this condition.     

Extremale geschlossene Differentialformen Unterschallströmungen im Großen

Ohne Zusammenfassung Leon Lichtenstein zum Gedächtnis     

Über die Additivität von Spektralmaßen

Ohne ZusammenfassungSponsored by the U. S. Army Research Office.