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Showing papers on "Overhead (computing) published in 1983"


Dissertation
01 Jan 1983
TL;DR: A nested action management algorithm is presented that is the first such algorithm to separate remote call semantics from action units, and guarantees that orphans, computational parts of actions that will be eventually aborted, view consistent system states.
Abstract: Constructing reliable programs for distributed processing systems is a very difficult task. Actions (transactions), indivisible units of work, can simplify this process by providing uniform treatment of failures and preventing interference. These units of work can also be nested, further controlling the scope of concurrency and failures. The atomicity provided by actions is an important tool for building reliable decentralized systems. Actions manipulate pieces of data called objects. Objects are usually treated as uninterpreted (bit strings). However, treating all objects in this fashion can result in unacceptable concurrency or high recovery overhead. In order to take advantage of actions in the widest possible context, it is necessary to consider operations on generalized objects (instances of abstract data types). This report presents a general architectural model for reliable decentralized systems constructed using actions and objects. We include one prototype design created from the model. We also include practical algorithms necessary to implement this design. We present a nested action management algorithm that, to our knowledge, is the first such algorithm to separate remote call semantics from action units. It also guarantees that orphans, computational parts of actions that will be eventually aborted, view consistent system states. We describe a design for synchronization and recovery that is oriented toward a programming-based view of objects (as well as simple data). We demonstrate the usefulness of our results through typical reliable programming problems. Availability is another important dimension of distributed systems. We describe a novel collection of simple, yet very robust, replication algorithms which can increase data availability. Algorithms from this suite can be customized to balance particular tradeoffs required in different application systems. The efficiency of the algorithms depends on the acceptability of weak consistency conditions in the applications. One member of this suite is formally modelled and proven correct. The others follow in a straightforward manner.

128 citations


Journal ArticleDOI
TL;DR: The costs of practical strategies for managing a large register file are compared with a lower bound on this management overhead, obtained from a theoretical optimal strategy, for several register file sizes.
Abstract: The RISC (reduced instruction set computer) architecture attempts to achieve high performance without resorting to complex instructions and irregular pipelining schemes. One of the novel features of this architecture is a large register file which is used to minimize the overhead involved in procedure calls and returns. This paper investigates several strategies for managing this register file. The costs of practical strategies are compared with a lower bound on this management overhead, obtained from a theoretical optimal strategy, for several register file sizes.

49 citations


Proceedings Article
01 Jan 1983
TL;DR: The authors investigate one method of reducing the Von Neumann bottleneck by reducing addressing overhead and improves system performance by efficiently generating operand requests, making fewer memory references, and maximizing computation and access process overlap.
Abstract: The authors investigate one method of reducing the Von Neumann bottleneck. Program referencing behaviour is determined by analyzing dynamic address traces. The structured memory access (SMA) architecture uses a computation processor (CP) and a decoupled memory access processor (MAP) with special hardware for efficient accessing of program and data structures and for effective branch and loop management. Prototypical SMA machines are compared to conventional Vax-like machines. SMA machines perform significantly better than conventional machines with the same parameter values. The SMA architecture reduces addressing overhead and improves system performance by (1) efficiently generating operand requests, (2) making fewer memory references, and (3) maximizing computation and access process overlap. 8 references.

46 citations


Patent
Yoichi Tan1, Fumio Miyao1
22 Jun 1983
TL;DR: In this article, the line connection control data of the overhead field are inserted as repeated at least one time into the data field, and the parity bit is added to the overhead data.
Abstract: In a digital signal transmission system for effecting time-division multiplexing/circuit switching transmission of data in the form of packets by means of telecommunication cable, a packet configuration and line connection control data inserted in the packets are improved. In phases of the establishment/termination of a call, line connection control data of the overhead field are inserted as repeated at least one time into the data field. At least one set of line connection control data of the overhead field contains a parity bit. A receiving station reads the line connection control data in the overhead field and the data field of a received packet, and determines the overhead data by the principle of decision by majority. After completion of establishment of a call, the receiving station takes in the transferred data out of a block on the basis of a positional information, for example, a number of the block. In the phase of transmission of data, transmitting station inserts additional data bits into at least part of the overhead field in the packet being transmitted.

43 citations


Journal ArticleDOI
TL;DR: A new propagation algorithm is obtained which requires less memory overhead and is more stable than previously suggested methods and is adaptable to inhomogeneously broadened media.

35 citations


Patent
12 Jul 1983
TL;DR: In this paper, birds are moved in series along an overhead conveyor about a rotary support assembly 22, a spreader tool 45 moves down into the previously eviscerated cavity of each bird, a first disk cutter 68 cuts behind the spreader tools through the tissue extending from the breast to the back about the cavity, and a second disk cutter 69 cuts through the backbone of the bird.
Abstract: Birds are moved in series along an overhead conveyor about a rotary support assembly 22, a spreader tool 45 moves down into the previously eviscerated cavity of each bird, a first disk cutter 68 cuts behind the spreader tool through the tissue extending from the breast to the back about the cavity, the spreader tool is withdrawn from the bird, and a second disk cutter 69 cuts through the backbone of the bird.

20 citations


Patent
16 May 1983
TL;DR: In this article, an overhead communal parking installation for lightweight vehicles, especially bicycles, is described. But the technical problem posed consists in providing such an installation which protects the parked vehicles against crime, frees a space for driving on the ground, and which is entirely safe for passers-by.
Abstract: The invention relates to an overhead communal parking installation for lightweight vehicles, especially bicycles. The technical problem posed consists in providing such an installation which protects the parked vehicles against crime, frees a space for driving on the ground, and which is entirely safe for passers-by. The installation according to the invention consists of a pole 1 surmounted by a dome 3 closed by flaps 6 and delimiting the parking space. Vehicles are engaged in the carriage 4, seized by the gripper 26 and, after unlocking 5, automatically mounted by virtue of the counterweight 30 or by virtue of a motorising system. The vehicles are recovered manually via the return handle 42. The installation is mainly intended to be used as a public facility in towns or for the use of private groups (schools, factories, leisure centres, etc.).

18 citations


Journal ArticleDOI
TL;DR: The advantages of eye‐in‐hand vision are discussed and it is shown that with the Unimation VAL operating system it is easier to use than is possible with static overhead cameras.
Abstract: The advent of low cost miniature solid state cameras now makes eye‐in‐hand robot vision a practical possibility This paper discusses the advantages of eye‐in‐hand vision and shows that with the Unimation VAL operating system it is easier to use than is possible with static overhead cameras

17 citations


Journal ArticleDOI
01 Jan 1983
TL;DR: Theoretical predictions of pantograph/overhead interaction are described in this article, together with associated validation experiments and consequent hardware developments, and the concept of a combined pantograph overhead "system" is introduced.
Abstract: Theoretical predictions of pantograph/overhead interaction are described, together with associated validation experiments and consequent hardware developments. The concept of a combined pantograph overhead ‘system’ is introduced.

17 citations


01 Jan 1983
TL;DR: Parallel techniques are shown to eliminate some types of overhead associated with serial processing, offer the possibility of improved algorithm capability and accuracy, and decrease execution time.
Abstract: Contour extraction is used as an image processing scenario to explore the advantages of parallelism and the architectural requirements for a parallel computer system, such as PASM. Parallel forms of edge-guided thresholding and contour tracing algorithms are developed and analyzed to highlight important aspects of the scenario. Edge-guided thresholding uses adaptive thresholding to allow contour extraction where gray level variations would not allow global thresholding to be effective. Parallel techniques are shown to eliminate some types of overhead associated with serial processing, offer the possibility of improved algorithm capability and accuracy, and decrease execution time. The implications that the parallel scenario has for machine architecture are considered. Various desirable system attributes are established. 30 references.

14 citations


Patent
17 Oct 1983
TL;DR: In this article, the warhead is pivoted by means of a radial impeller and may be separated completely from the missile body, or remain pivoted thereto, Fig. 4.
Abstract: A missile for attacking a target from overhead comprises a war-head which, when the missile is above the target, pivots downwards towards the target. The war-head is pivoted by means of a radial impeller and may be separated completely from the missile body, Fig. 2, or remain pivoted thereto, Fig. 4.

Journal ArticleDOI
TL;DR: Variations on the binary search algorithm when placed in the context of a multiprocessing environment is considered and an organization combining interference-free access to memory by implicit synchronization and a small degree of cooperation yields the best results.
Abstract: In this paper we consider variations on the binary search algorithm when placed in the context of a multiprocessing environment. Several organizations are investigated covering the spectrum from total independence (or free competition for access to common resources) to cooperation as in SIMD architectures. It is assumed that the two main sources of overhead are memory interference and interprocessor synchronization. An organization combining interference-free access to memory by implicit synchronization and a small degree of cooperation yields the best results.

Journal ArticleDOI
TL;DR: A method is shown that can be implemented efficiently at large PLAs that only needs a system clock and an initialization signal to produce a go/no-go signal after an AND plane size-dependent delay.

Journal ArticleDOI
TL;DR: This leads to the use of Recovery Block software techniques as well as hardware watchdog timers and traps, to increase the system availability during fault conditions, which shows significant improvement in performance for 15-20% software and execution time overhead.



01 Jan 1983
TL;DR: Theoretical predictions of the pantograph/overhead interaction are described in this article, together with associated validation experiments and consequent hardware developments, and the concept of a combined pantograph overhead "system" is introduced.
Abstract: Theoretical predictions of pantograph/overhead interaction are described, together with associated validation experiments and consequent hardware developments. The concept of a combined pantograph overhead "system" is introduced.


01 Jan 1983
TL;DR: In this paper, the authors discuss the interface between host computers and database backends and the communication characteristics (data rate, overhead) together with their effects on throughput, response time and host CPU offload in a simulation model.
Abstract: This paper discusses the interface between host computers and database backends. The logical interface (single tuple vs set transfer) and the communication characteristics (data rate, overhead) together with their effects on throughput, response time and host CPU offload are investigated in a simulation model.

01 Dec 1983
TL;DR: This invention is a method for decreasing the arbitration overhead required to transfer messages on a shared multiprocessor bus.
Abstract: This invention is a method for decreasing the arbitration overhead required to transfer messages on a shared multiprocessor bus.


Proceedings ArticleDOI
16 May 1983
TL;DR: A new concept for providing software fault tolerance in concurrent systems that combines the traditional global-checkpointing mechanism with the recovery-block concept in order to come up with an easily implementable errorrecovery mechanism is proposed.
Abstract: The paper proposes a new concept for providing software fault tolerance in concurrent systems. It combines the traditional global-checkpointing mechanism with the recovery-block concept in order to come up with an easily implementable errorrecovery mechanism. This mechanism involves smaller overhead in case of moderate to high process interaction than the schemes considered in the past, which are based upon the idea of local checkpointing. A model for computing the optimum checkpointing interval is also presented. A particular distribution is hypothesized for the coverage of the recovery and the behavior of the model studied in detail for this case.



Journal ArticleDOI
TL;DR: A new technique for providing software fault tolerance in concurrent systems is proposed that combines the traditional global checkpointing mechanism with the recovery block concept in order to come up with an easily implementable error recovery mechanism.

Patent
14 Jul 1983
TL;DR: In this paper, a current collector for route-bound electric vehicles, such as locomotives, trams, buses or the like moving under overhead lines, is disclosed, in which, for the purpose of punctually detecting a necessary contact element change of the current collector, an optical waveguide is arranged along a wear limit, of the contact element, provided at a distance from the surface of contact.
Abstract: A current collector for route-bound electric vehicles, such as locomotives, trams, buses or the like moving under overhead lines, is disclosed, in which, for the purpose of punctually detecting a necessary contact element change of the current collector, an optical waveguide is arranged along a wear limit, of the contact element, provided at a distance from the surface of the contact. The destruction of the optical waveguide when the predetermined wear limit is reached is converted into a warning signal which indicates to the driver the necessity of changing the contact element.

01 Jun 1983
TL;DR: In this article, the authors deal with the method used in design practice for calculating icing loads on overhead line conductors and the relationship between the probability of exceeding the standard icing load on OH lines and the length of the latter is analyzed.
Abstract: : The paper deals with the method used in design practice for calculating icing loads on overhead line conductors. Relationship between the probability of exceeding the standard icing load on OH lines and the length of the latter is analyzed. (Author)

Journal ArticleDOI
TL;DR: It is concluded that overhead projections add no information to the examination, are not cost-effective, and can be eliminated without detriment to the patient.
Abstract: The usefulness of routine overhead views in the double-contrast investigation of the stomach and duodenum was evaluated. In this series, overhead views missed 26% of the lesions diagnosed and diagnosed no lesion not also seen on spot films. The authors could thus find no indication for the routine use of overhead views. It is concluded that overhead projections add no information to the examination, are not cost-effective, and can be eliminated without detriment to the patient.