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Showing papers on "Overhead (computing) published in 1984"


Journal ArticleDOI
TL;DR: Dart differs from previous approaches to diagnosis taken in the design-automation community in that it is more general and in many cases more efficient, and allows it to be applied to a wide class of devices ranging from digital logic to nuclear reactors.

598 citations


Book
01 Jan 1984
TL;DR: This thesis concerns the design of interactive, language-based programming environments that use knowledge of a programming language to provide functions based on the structure and meaning of programs, and describes how it is possible to reduce the amount of storage overhead required for updating trees in optimal time.
Abstract: This thesis concerns the design of interactive, language-based programming environments that use knowledge of a programming language to provide functions based on the structure and meaning of programs. The goal of the research is a system-constructor to enable editors for different languages to be created easily. The most challenging aspect of such a system is the design of the semantic component, because a language-based editor performs static semantic analysis when a program is altered in order to detect erroneous constructions or to prevent illegal modifications. For efficiency, this should be performed incrementally, re-using as much old information as possible; therefore, a major focus of my research concerns a model of editing for which it is possible to perform incremental semantic analysis efficiently. In this model, a program is represented as an attributed tree in which all attributes have consistent values; programs are modified by tree operations such as pruning, grafting, and deriving. After each modification, some of the attributes require new values; incremental semantic analysis is performed by updating attribute values to again make them all consistent. The thesis presents several algorithms for this process that are asymptotically optimal in time. The chief disadvantage of attribute grammars is that they use large amounts of storage. The thesis discusses three aspects of utilizing storage efficiently in such systems. One way to reduce the amount of storage used is to reduce the number of atttribute values retained at any stage of attribute evaluation. The thesis establishes two results concerning this idea: it presents one algorithm for evaluating an n-attribute tree that never saves more than $O(\sqrt{n}$ attribute values, and it presents a second algorithm that never saves more than $O(\log n)$ attribute values. A second method for reducing the amount of storage is to share the space used for storing attributes whose values are complex data structures; the thesis presents a very general method for such sharing that can be applied to attributes of many types. Finally, the thesis describes how, by restricting the class of attribute grammars, it is possible to reduce the amount of storage overhead required for updating trees in optimal time.

268 citations


Proceedings Article
16 Oct 1984
TL;DR: In this article, a technique for designing easily testable PLAs is presented, which consists of the addition of a small number of bit lines in such a way that, in test mode, any single product line can be activated and its associated circuitry and devices tested.
Abstract: A new technique for designing easily testable PLAs is presented. The salient features of this technique are: 1) low overhead, 2) high fault coverage, 3) simple design, 4) little or no impact on normal operation of PLA and 5) elimination of the need for test pattern generation. This technique consists of the addition of a small number of bit lines in such a way that, in test mode, any single product line can be activated and its associated circuitry and dev ices tested. Using this technique all multiple stuck-at faults, as well as all multiple extra and multiple missing device faults, are detected.

59 citations


Book
01 Jan 1984
TL;DR: The overall result is that the larger the problem, the closer the algorithms approach optimal speedup, which allows algorithms to be designed assuming any number of processing elements.
Abstract: We present and analyze several practical parallel algorithms for multicomputers. Chapter four presents two distributed algorithms for implementing alpha-beta search on a tree of processors. Each processor is an independent computer with its own memory and is connected by communication lines to each of its nearest neighbors. Measurements of the first algorithm's performance on the Arachne distributed operating system are presented. For each algorithm, a theoretical model is developed that predicts speedup with arbitrarily many processors. Chapter five shows how locally-defined iterative methods give rise to natural multicomputer algorithms. We consider two interconnection topologies, the grid and the tree. Each processor (or terminal processor in the case of a tree multicomputer) engages in serial computation on its region and communicates border values to its neighbors when those values become available. As a focus for our investigation we consider the numerical solution of elliptic partial differential equations. We concentrate on the Dirichlet problem for Laplace's equation on a square region, but our results can be generalized to situations involving arbitrarily shaped domains (of any number of dimensions) and elliptic equations with variable coefficients. Our analysis derives the running time of the grid and the tree algorithms with respect to per-message overhead, per-point communication time, and per-point computation time. The overall result is that the larger the problem, the closer the algorithms approach optimal speedup. We also show how to apply the tree algorithms to non-uniform regions. A large-network algorithm solves a problem of size N on a network of N processors. Chapter six presents a general method for transforming large-network algorithms into quotient-network algorithms, which solve problems of size N on networks with fewer processors. This transformation allows algorithms to be designed assuming any number of processing elements. The implementation of such algorithms on a quotient network results in no loss of efficiency, and often a great savings in hardware cost.

48 citations


Proceedings ArticleDOI
01 Dec 1984
TL;DR: The Invariance thesis which states that all standard models of computing devices are sufficiently equivalent is appealed to, among others, that a RAM can be simulated by a Turingmachine with constant factor overhead in space.
Abstract: In Complexity Theory the use of informal estimates can be justified by appealing to the Invariance thesis which states that all standard models of computing devices are sufficiently equivalent. This thesis would require, among others, that a RAM can be simulated by a Turingmachine with constant factor overhead in space. Such a simulation is hard to obtain if the traditional spacemeasure for RAM-space is used. The simulation uses a new method for condensing space, based on perfect hashing.

24 citations


Journal ArticleDOI
01 Sep 1984-Networks
TL;DR: The number of message required for synchronous update is shown to be an upper bound for the number of messages required if update occurs asynchronously, and some implementation suggestions aimed at minimizing looping of messages during routing table update are presented.
Abstract: This paper is an analysis of overhead required by the MERIT routing table update algorithm after failure of a single network resource. The number of update messages sent by each node during the update process is used as the measure of update overhead. Both synchronous behavior and asynchronous behavior of the MERIT algorithm are considered. The number of messages required for synchronous update is shown to be an upper bound for the number of messages required if update occurs asynchronously. The effect of network topology on update overhead is discussed. Finally, some implementation suggestions aimed at minimizing looping of messages during routing table update are presented.

15 citations


Journal ArticleDOI
Gerald Parks Bozman1
TL;DR: A lookaside buffer is the software analog to the ha rdware cache in that a hit in the lookasideside buffer can save significant overhead in accessing an i tem in the l inked list.
Abstract: Linked lists are one of the most f requent ly used data s t ructures in compu te r sof tware [3, 5]. Unfor tuna te ly thei r advantages are often offset by a high search overhead. This is especial ly t rue in mach ines that have a cache I [6] because the dis tance b e t w e e n list e lements often exceeds the cache line, that is, the q u a n t u m of storage in the cache. On the IBM 3081, for example , a cache miss can requi re 20-30 t imes more mach ine cycles than a cache hit. Since it is not unusua l for the search dis t r ibut ion against l inked lists to be ex t r eme ly nonuni form, a software lookaside buffer 1 can yield significant performance benefi ts at the expense of a modes t analysis and p rogramming effort. In this context , a lookaside buffer is the software analog to the ha rdware cache in that a hit in the lookaside buffer can save significant overhead in accessing an i tem in the l inked list. Al though lookaside buffers can be appl ied to o ther data structures, we have seen the greatest ove rhead reduc t ion wi th l inked lists.

12 citations


Patent
19 Mar 1984
TL;DR: In this paper, the stuff bit code for appropriate frames of a high speed transmission line can be violated and remotely detected whereby the signal is looped back at the destination end of the desired signal whether the remote signals are in the DS1C or DS1 data format.
Abstract: The overhead format for DS1C data must be removed and the data broken into two DS1 format data signals before being transmitted over DS2 or DS3 transmission lines. The present invention demonstrates a method whereby the stuff bit code for appropriate frames of a high speed transmission line can be violated and remotely detected whereby the signal is looped back at the destination end of the desired signal whether the remote signals are in the DS1C or DS1 data format.

11 citations


Patent
13 Nov 1984

9 citations




Proceedings Article
16 Oct 1984
TL;DR: A methodology is proposed for the design of go/no go built-in test for data paths in VLSI circuits and the results of a design study dealing with tradeoffs between testing time, device count overhead, and testability features are presented.
Abstract: A methodology is proposed for the design of go/no go built-in test for data paths in VLSI circuits. The results of a design study dealing with tradeoffs between testing time, device count overhead, and testability features are presented.

Journal ArticleDOI
TL;DR: In this paper, an overhead polarimeter that relies on small amounts of chiral solution and provides a "dual beam" light source for direct comparison of plane-polarized light emerging from chiral and achiral media.
Abstract: Design and application of an overhead polarimeter that relies on small amounts of chiral solution and provides a "dual beam" light source for direct comparison of plane-polarized light emerging from chiral and achiral media.

Journal ArticleDOI
Yahya Badran1
TL;DR: The problem of departmental full costing is solved here via goal programming models viaGoal programming models for the solution of overhead allocation.



Journal ArticleDOI
TL;DR: This paper extends Hoare's and Brinch Hansen's monitor concept, and introduces a resource monitor language construct that represents a resource manager object that is compared to current language constructs used to structure operating system software.
Abstract: Resource manager objects are the operating system entities that manage computer system resources. In this paper we extend Hoare's and Brinch Hansen's monitor concept, and introduce a resource monitor language construct that represents a resource manager object. Resource monitors provide requesting processes with implicit synchronization, and do not require separate processes to perform the resource access operations. The resource monitor construct is compared to current language constructs used to structure operating system software. For this purpose we use an evaluation methodology that combines software complexity measurements with program performance measurements. The evaluation itself is carried out in a Concurrent Pascal-like programming environment. The current language constructs have a software complexity that is larger by 37 to 219 per cent over the resource monitor's complexity. The run-time synchronization overhead of programs that use current language constructs is 1.43 to 2.75 times higher than the overhead of programs that use a resource monitor.

Journal ArticleDOI
TL;DR: In this paper, a mathematical model of a multi-conductor overhead power line with spacer-dampers is presented, and an outline is presented of the application of this method to the control of Aeolian vibration by using self-damping spacers, and in the companion paper (Part II) subconductor oscillation is considered.

Patent
23 Apr 1984
TL;DR: In this paper, an operator's compartment for a mobile machine, such as a machine used in underground mining operations, is pivotally connected to the machine frame for positioning at a preselected elevation above the ground or in contact with the ground to follow the contour of the ground in a "free floating" condition.
Abstract: An operator's compartment for a mobile machine, such as a machine used in underground mining operations, is pivotally connected to the machine frame for positioning at a preselected elevation above the ground or in contact with the ground to follow the contour of the ground in a "free floating" condition. The first overhead canopy is supported above the operator's compartment at a fixed elevation. Positioned beneath the first overhead canopy is an operator's seat securely positioned on the platform to provide an operator's station from which the machine is operated. Positioned in underlying relation with the first overhead canopy is a second overhead canopy that extends forwardly from the operator's station. The first and second canopies provide for complete overhead protection of an operator. The second overhead canopy is pivotally connected at one end to the machine frame and includes at the opposite end a control panel which is suspended downwardly from the second overhead canopy to a position opposite the operator's seat. Suitable height adjustment means, such as a fixed length or piston cylinder assembly, is connected to the second overhead canopy to permit adjustments in the elevation of the second canopy and the control panel. With this arrangement not only is the second canopy adjustable relative to the first, but the control panel may be repositioned on the platform to allow a change in the position of the controls to suit the operator.

Patent
06 Sep 1984
TL;DR: In this paper, a drive device for an overhead monorail in conveyor systems is described, where travel gear is suspended from an l-shaped carrier as a rail and is guided with the aid of guide rollers.
Abstract: The subject matter of the invention is a drive device for an overhead monorail in conveyor systems. The travel gear is suspended from an l-shaped carrier 1 as a rail and is guided with the aid of guide rollers 4. The travel gear itself has a running roller 5 which is held on a U-shaped carrier 3 and is guided on the rail 1. The drive 6 which has a drive gear wheel 7 which engages in a toothed rail 8 which is attached to the rail 1 is held on said carrier 3.


Patent
21 Jun 1984
TL;DR: In this paper, the authors propose to simplify a control means and to attain the operation of confirmation of transmission with high speed by connecting a carrier on a transmission line while transmission information and transmission confirming information are transmitted and received.
Abstract: PURPOSE:To simplify a control means and to attain the operation of confirmation of transmission with high speed by connecting a carrier on a transmission line while transmission information and transmission confirming information are transmitted and received. CONSTITUTION:After transmission information 10 is transmitted, a transmission side station transmits a dummy data D1 for a suitable time and after the information 10 is received a receiving side station transmits a dummy data D2 for a suitable time before the transmission of transmission confirming information 11. Then, although a part CL where a part of the data D1, D2 is collided is generated on a transmission line 1, the information 11 is avoided from being destructed by the collision and the part CL is thrown away by error check. Since the carrier on the transmission line 1 is connected while the information 10, 11 are transmitted and received, no transmission from other stations is not interrupted, the control means is simplified, the overhead of processing is reduced and the confirmation of transmission is operated in high speed.





Journal ArticleDOI
TL;DR: In this article, the authors argue that due to the presence of quasi-fixed overhead labour, the aggregate short-run production function of the industry has the property of bounded substitutability.
Abstract: In this paper we argue that due to the presence of quasi-fixed overhead labour, the aggregate short-run production function of the industry has the property of bounded substitutability. That is, when employing overhead labour, the industry will only be able to earn a positive quasi-rent for a bounded interval of aggregate labour intensity.

Proceedings Article
16 Oct 1984
TL;DR: It is shown in this paper that it can reduce the error rate due to ionizing radiation to insignificant levels and a comparative analysis of the overhead implied by the approach and alternative existing methods is given.
Abstract: A new approach for providing tolerance to soft errors in digital circuits is presented. This approach is based on filtering transients at register inputs. It is shown in this paper that it can reduce the error rate due to ionizing radiation to insignificant levels. A comparative analysis of the overhead implied by our approach and alternative existing methods is also given.

Journal ArticleDOI
TL;DR: In this article, an exact analysis of the modal form of the transmission line transient has been formulated and a comparison of its accurate evaluation is made with other workers' available results.
Abstract: An examination is made of past, present and possible future results in evaluating the modal form of the transmission-line transient. An exact analysis of the problem has been formulated and a comparison of its accurate evaluation is made with other workers' available results.