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Showing papers on "Overhead (computing) published in 1976"


Journal ArticleDOI
TL;DR: This paper considers the optimization of a single query defined by an expression of the relational algebra that is transformed into an equivalent expression or sequence of expressions that cost less to evaluate.
Abstract: This paper examines optimization within a relational data base system It considers the optimization of a single query defined by an expression of the relational algebra The expression is transformed into an equivalent expression or sequence of expressions that cost less to evaluate Alternative transformations, and combinations of several transformations, are analyzed Measurements on an experimental data base showed improvements, especially in cases where the original expression would be impracticably slow in its execution A small overhead was incurred, which would be negligible for large data bases

71 citations


Journal ArticleDOI
TL;DR: Some measurements of line efficiency for the ARPANET are presented and by extrapolation these measurements are used to anticipate overhead in a heavily loaded network.
Abstract: The form, extent, and effect of the communication line overhead in the ARPANET are considered The source of this overhead is separated into various levels of protocol hierarchy and the characteristics of each level are summarized Then the line efficiency for various models of system use is studied Some measurements of line efficiency for the ARPANET are presented and by extrapolation these measurements are used to anticipate overhead in a heavily loaded network Similar results are derived for a recently proposed network protocol and compared with those for the current system

51 citations


Proceedings ArticleDOI
02 Jun 1976
TL;DR: The paper describes three extensions of a conceptual model and system into a practical tool for evaluation of existing or proposed database designs: batched transactions, multi-access interference due to shared secondary storage, and variable record size.
Abstract: The File Design Analyzer is a software package which evaluates well-known database storage structures and access methods in terms of secondary storage processing time and storage overhead required to service a set of user applications. It implements a first-order analytical model to specifically evaluate sequential, indexed sequential, direct access, inverted, multilist, and network storage structures. Interaction with the package is available in conversational mode, enabling the experienced analyst to conduct on-line sensitivity analysis.The paper describes three extensions of a conceptual model and system into a practical tool for evaluation of existing or proposed database designs: batched transactions, multi-access interference due to shared secondary storage, and variable record size. Case studies of real systems illustrate the potential of the File Design Analyzer to provide insight regarding the optimal choice of physical parameters within a specified storage structure and to effectively compare alternative storage structures for a particular set of applications.

32 citations


Patent
18 Oct 1976
TL;DR: In this article, a striking device for use by a trainee in karate, boxing, etc., to simulate an opponent is presented, where target elements are suspended by a cord from a fixed overhead position and pivoted rod-mounted response elements are balanced between the target elements.
Abstract: A striking device for use by a trainee in karate, boxing, etc., to simulate an opponent. Target elements are suspended by a cord from a fixed overhead position and pivoted rod-mounted response elements are balanced between the target elements. When the trainee strikes the target elements, the response elements move in an unpredictable manner to strike back at the trainee.

27 citations


Book ChapterDOI
01 Jan 1976
TL;DR: In this paper, the authors describe the design of sparse Gaussian elimination codes and examine possible tradeoffs among the design goals of flexibility, speed, and small size, and discuss the effects of certain flexibility and cost constraints on the design.
Abstract: Publisher Summary This chapter explains the considerations required in the design of software for sparse Gaussian elimination. Several implementations of sparse Gaussian elimination have been developed to solve systems. When a large sparse system of linear equations Ax = b is considered, where A is an N × N sparse nonsymmetric matrix and x and b are vectors of length N, the basic idea of all of these is to factor A and to compute x without storing or operating on zeroes in A, L, or U, where L is a unit lower triangular matrix and U is a unit upper triangular matrix. Doing this requires a certain amount of storage and operational overhead, that is, extra storage for pointers in addition to that needed for nonzeroes, and extra nonnumeric bookkeeping operations in addition to the required arithmetic operations. All these implementations of sparse Gaussian elimination generate the same factorization of A and avoid storing and operating on zeroes. Thus, they all have the same costs as measured in terms of the number of nonzeroes in L and U or the number of arithmetic operations performed. However, the implementations do have different overhead requirements and thus their total storage and time requirements vary a great deal. The chapter describes the design of sparse Gaussian elimination codes. It discusses the effects of certain flexibility and cost constraints on the design, and examines possible tradeoffs among the design goals of flexibility, speed, and small size.

23 citations


Journal ArticleDOI
TL;DR: This paper analyzes adaptive CPU allocation policies to reduce the overhead during high traffic conditions when saturation of this resource is more likely while keeping a small quantum during periods of low arrival traffic, and results to illustrate the effect of this policy are presented.
Abstract: The allocation of the central processing unit (CPU) of a computer system in quanta of fixed length in round-robin fashion favors jobs with shorter total CPU processing time by reducing the time they spend waiting in queue below what it would be if all the lobs were served in first-come-first-served order This effect can be accentuated by the use of short quanta. The main disadvantage of this allocation policy is the resulting time the CPU spends in overhead activities when switching from one task to the other, this too will increase with smaller quanta. Thus, it appears useful to consider adaptive CPU allocation policies to reduce the overhead during high traffic conditions when saturation of this resource is more likely while keeping a small quantum during periods of low arrival traffic. In this paper we analyse such a policy, it is assumed that each time at least r (a threshold) arrivals occur during a quantum, the job currently using the CPU is allocated an additional quantum (if It is needed). Thus, the number of job arrivals during a quantum is used as a sensor of the intensity of arrival traffic. This policy, which can be easily implemented in hardware, is analysed using a mathematical model yielding the average response time for jobs as a function of mean total CPU time, the quantum size, r, and a fixed overhead for switching tasks, with a Poisson arrival process. Numerical results to illustrate the effect of this policy are presented.

22 citations


Patent
30 Jun 1976
TL;DR: In this article, an organization of logic in a Level Sensitive Scan Design (LSSD) system was proposed to render the clock networks testable with minimal overhead, and the advantages of the practice of the invention are particularly apparent and enhanced when the invention is employed in a LSSD System generally of the type disclosed in U.S. patent application Ser. No. 3,783,254 and No. 701,052, filed June 30, 1976.
Abstract: The disclosure relates to LSSD systems for use in digital computers and the like. More particularly, to an organization of logic in such systems to render the clock networks testable with minimal overhead. The advantages of the practice of the invention are particularly apparent and enhanced when the invention is employed in a Level Sensitive Scan Design (LSSD) System generally of the type disclosed in U.S. Pat. No. 3,783,254 and U.S. patent application Ser. No. 701,052, filed June 30, 1976.

21 citations


Patent
07 Jul 1976
TL;DR: In this paper, an elevatable and adjustable scaffold device for supporting ceiling or other panels usually attached to overhead rafters and ceiling beams, operable by one person and capable of fine adjustment for height, as well as length and width for working in small rooms.
Abstract: An elevatable and adjustable scaffold device for supporting ceiling or other panels usually attached to overhead rafters and ceiling beams, operable by one person and capable of fine adjustment for height, as well as length and width for working in small rooms.

20 citations


Patent
22 Sep 1976
TL;DR: An overhead protective device for a bed including a canopy having a framework composed of a plurality of longitudinal and transverse trusses, a layer of wire network and an ornamental layer of fabric, all supported upon reinforced standards or posts projecting upward from the corners of the bed frame is described in this article.
Abstract: An overhead protective device for a bed including a canopy having a framework composed of a plurality of longitudinal and transverse trusses, a layer of wire network and an ornamental layer of fabric, all supported upon reinforced standards or posts projecting upward from the corners of the bed frame.

18 citations


Patent
18 Aug 1976
TL;DR: In this paper, a high reliability by transmitting the information through an optical fiber, with the optical fiber assembled into the aerial power transmission wire or overhead earth wire, was proposed to provide high reliability.
Abstract: PURPOSE:To provide a high reliability by transmitting the information through an optical fiber, with the optical fiber assembled into the aerial power transmission wire or overhead earth wire.

16 citations



Patent
04 May 1976
TL;DR: In this article, material handling apparatus for use in loading large heavy and/or cumbersome articles such as concrete slabs, wall segments or other articles of like configuration on a mobile vehicle and transporting and installing the same comprising a frame-work supporting an overhead platform mounting article loading means and incorporating means for laterally shifting, tilting and vertically adjusting said platform as needs require.
Abstract: Material handling apparatus for use in loading large heavy and/or cumbersome articles such as concrete slabs, wall segments or other articles of like configuration on a mobile vehicle and transporting and installing the same comprising a frame-work supporting an overhead platform mounting article loading means and incorporating means for laterally shifting, tilting and vertically adjusting said platform as needs require.


Patent
08 Dec 1976
TL;DR: The highvoltage network for areas of increased intensity of icing comprises supply and distribution substations, a switching center positioned at the distribution substation and connecting at least one conductor of the overhead transmission line to a different number of conductors of the additional overhead transmission lines when the icing is to be melted on conductors by the direct current.
Abstract: The high-voltage network for areas of increased intensity of icing comprises supply and distribution substations, an overhead transmission line connecting the supply and distribution substations, an additional overhead transmission line leading from the distribution substation, a rectifier for melting the icing with direct current installed at the supply substation, and a switching center positioned at the distribution substation and connecting at least one conductor of the overhead transmission line to a different number of conductors of the additional overhead transmission line when the icing is to be melted on conductors of the additional overhead transmission line by the direct current.

Patent
10 Aug 1976
TL;DR: In this paper, an automatic cleaner for overhead conveyor rails which has independently driven wheels riding on the rail and supporting a carriage having vertically disposed rotatable brushes which are axially rotated for progressively cleaning opposite sides of the rail as the carriage traverses the rail in either direction.
Abstract: An automatic cleaner for overhead conveyor rails which has independently driven wheels riding on the rail and supporting a carriage having vertically disposed rotatable brushes which are axially rotated for progressively cleaning opposite sides of the rail as the carriage traverses the rail in either direction. The brushes are automatically adjusted vertically while rotating to avoid interference with rail hanger brackets and other obstructions on the rail.

Journal ArticleDOI
01 Aug 1976
TL;DR: For random errors the optimum data-block length is found to be proportional to √(a/k), and the maximum efficiency a function of ka, where a is the message overhead and k is the error rate.
Abstract: The study considers the effect of error rate, block length, transmission delay, and error-recovery mechanism on the efficiency of the communications channel in computer-computer communications. The systems investigated are full-duplex communications with unlimited and limited buffering, and half-duplex communications. Both random and burst errors are considered. For all cases, over a significant range of parameters, closed-form expressions for the optimum block length, and the corresponding efficiency are obtained. For random errors the optimum data-block length is found to be proportional to √(a/k), and the maximum efficiency a function of ka, where ais the message overhead and k is the error rate. The burst error results are similar.

Patent
20 Dec 1976
TL;DR: A unitary hanger is provided for supporting from the lower web of a single, overhead I-beam support the trolley rail, the advancing reach, and one or more returning reaches of a drop finger conveyor.
Abstract: A unitary hanger is provided for supporting from the lower web of a single, overhead I-beam support the trolley rail, the advancing reach, and one or more returning reaches of a drop finger conveyor.

Patent
26 Aug 1976
TL;DR: In this paper, the ends of the overhead conductor rail are overlapped in parallel tracks with one rail gradually lifted to enable the other to support the pantograph, and an intermediate support wire is arranged between the upper support wire and the cables.
Abstract: The ends of the sections of the overhead conductor rail are overlapped in parallel tracks with one rail gradually lifted to enable the other to support the pantograph. In order to ensure an accurate positioning of the two cables an intermediate support wire is arranged between the upper support wire and the cables. This has Y-shaped connections to the overhead cables to ensure proper spacing without any danger of the two sections touching. The overlapping sections run for at least five support masts.

Journal ArticleDOI
01 Apr 1976
TL;DR: It is shown that in a computer organization which is based on partitioning functionally interrelated hardware and software components together into functionally independent nodes, the interfunctional overhead activity can be reduced to a minimum and this type of organization produces optimal system performance, i.e., response time, throughput and system availability.
Abstract: It is shown in this paper that in a computer organization which is based on partitioning functionally interrelated hardware and software components together into functionally independent nodes, the interfunctional overhead activity can be reduced to a minimum. The reduction of the interfunctional overhead activity, which is the main contributor to poor system performance, results in a corresponding increase in system performance. In addition it is shown that in a functionally distributed system organization there exists a sequential job-shop or pipeline like flow of information (data and supervisory overhead) within the computer system which is essentially application independent. It is this type of flow that introduces a basic structure into the system which is practically non-existent in a centralized system architecture.In summary, the functionally distributed computer architecture proposed in this paper is based on a structured flow of blocks of information with a minimum of supervisory overhead through functionally independent but sequentially cooperating nodes. It is shown that this type of organization produces optimal system performance, i.e., response time, throughput and system availability.

Patent
28 Oct 1976
TL;DR: In this article, the overhead conductor rail is suspended from a support catenary by a set of special hangers which also serve to dampen vibrations, and they are made from interwined helical metal coils arranged so that the coils rub over each other as the hangers flex.
Abstract: The overhead conductor rail is suspended from a support catenary by a set of special hangers which also serve to dampen vibrations. The hangers are made from interwined helical metal coils (2) arranged so that the coils rub over each other as the hangers flex. This provides sufficient frictional force to dampen the support. The system is much lighter and simpler than dampers comprising hydraulic rams etc., and also dampens lateral vibrations. Alternatively braided metal sleeves can be used with the braidings flexing and sliding over each other.

Patent
23 Dec 1976
TL;DR: In this paper, the overhead rail guided automatic transport system is powered by travelling wave magnetic system and the support structure is designed so that the overhead transport system not put out of commission should a road vehicle collide with one of the track supporting columns.
Abstract: The overhead rail guided automatic transport system is powered by travelling wave magnetic system. The support structure is designed so that the overhead transport system is not put out of commission should a road vehicle collide with one of the track supporting columns. The overhead track support sections are joined by bolted connections to the upper and lower members of the track support beam and the connection point is situated away from the column position about twenty to thirty percent of the column spring. When the support beam is deformed no situation can arise in which the overhead transport vehicle is blocked and the sliding characteristics of the transport vehicle are maintained.

Patent
26 Aug 1976
TL;DR: The overhead electric conductor (2) is divided into sections of equal length by cross-connectors (5, 6, 7) which connect the conductor to a main supply cable (3), with the impedance of two cables chosen so that the lower impedance main cable connects the current flow to the relevant section of overhead cable by two cross conductors as mentioned in this paper.
Abstract: The overhead electric conductor (2) is divided into sections of equal length by cross-connectors (5, 6, 7) which connect the conductor to a main supply cable (3). The main supply cable carries most of the current, with the impedance of the two cables chosen so that the lower impedance main cable connects the current flow to the relevant section of overhead cable by two cross conductors. The overhead conductor cable is thus only under heavy current in short bursts. The main supply cable (3) is coaxial, with an outer earthed sheath and is either a ground line or a support cable for the overhead line.

Journal ArticleDOI
01 Apr 1976
TL;DR: A computer organization is outlined (called a streaming processor) which operates on long data streams with considerably less instruction processing overhead: fetching and decoding.
Abstract: There are several operations in non-numeric processing which can be classified as file operations. These operations include such things as sorting, searching, and table lookup. They are characterized by their repetitious, homogeneous treatment of fields within records within files. Present computer organizations generally require several instructions imbedded in a loop to process each source-operand pair. This paper outlines a computer organization (called a streaming processor) which operates on long data streams with considerably less instruction processing overhead: fetching and decoding. Thus a greater percentage of the storage bandwidth is used for data and consequently the streaming processor is more efficient for such file operations.


Patent
02 Jan 1976
TL;DR: In this paper, the neutral cable is used as a support wire to prevent cable oscillation and reduce the overall load on pylons, which is suitable for bare cables at voltages up to 1Kv.
Abstract: This overhead cable support can use the neutral cable (8), strung between pylons, as a support wire. It has a hook (16) so that it can hang at intervals along the support wire. Its vertical body has arms with hooks at the extremities to locate the other conductors. These are held in place by plastic loops secured in notches in the arms. The supports are suitable for bare cables at voltages up to 1Kv. They are economic, prevent cable oscillation and reduce the overall load on pylons.

Patent
15 Nov 1976
TL;DR: In this paper, a device for providing an essential parts material for an electromotive vehicle and a working vehicle providing a smooth run of an overhead travelling crane even in a case when a running rail is based along not only a rectilineal course but a curved route and an inclined route.
Abstract: PURPOSE:To provide a device for providing an essential parts material for an electromotive vehicle and a working vehicle providing a smooth run of an overhead travelling crane even in a case when a running rail is based along not only a rectilineal course but a curved route and an inclined route.

Journal ArticleDOI
TL;DR: This paper focuses on the treatment of maps for projection by 35 mm slides or overhead methods, and examines the design of maps as printed material in the post war years.
Abstract: Whilst it can be fairly stated that the post war years have seen an upsurge of interest in the design of maps as printed material, the same cannot be said of the treatment of maps for projection, whether by 35 mm slides or overhead methods.

Journal ArticleDOI
E.N. Fox1
TL;DR: In this paper, a wave solution is derived for the dynamic response of the overhead system to a time-dependent travelling concentrated load applied direct to the wire, when the velocity of the mass along the wire exceeds a certain critical value.