No abstract available.

This paper describes how the work organization and computer system of the New Business Department at a large life insurance firm have interacted and evolved over time. The dynamics of interaction are explained largely in terms of the economic incentive to reduce the length of transaction processing chains and the more political goal of extending managerial control. It is argued that examining the interaction of organizations and computer systems Can contribute to a better theoretical understanding of the development of large computer systems and offer guidance to designers of user-computer interfaces. A graphical technique for depicting organizational interfaces is presented.

This paper describes how the work organization and computer system of the New Business Department at a large life insurance firm have interacted and evolved over time. The dynamics of interaction are explained largely in terms of the economic incentive to reduce the length of transaction-processing chains and the more political goal of extending managerial control. It is argued that examining the interaction of organizations and computer systems can contribute to a better theoretical understanding of the development of large computer systems and offer guidance to designers of user-computer interfaces. A graphical technique for depicting organizational interfaces is presented.

File organizations based on conventional hash functions provide faster access to the stored records in comparison with tree-like file structures. Tree structures such as B + -trees and ISAM do provide for sequential processing, but require considerable storage for the indices. When sequential processing is needed a table that performs an order-preserving transformation on keys can be used. H is an order-preserving key transform if H(K 1 ) ⩾ H(K 2 ), for all keys K 1 > K 2 . We present methodologies for constructing such key transforms, and illustrate them for some real-life key sets. Storage requirements for the table needed to carry out the transformation are less than those needed for the indices.

A unifying model for the study of database performance is proposed. Applications of the model are shown to relate and extend important work concerning batched searching, transposed files, index selection, dynamic hash-based files, generalized access path structures, differential files, network databases, and multifile query processing.

No abstract available.

A queueing model of movable-head disk storage systems is developed so that the performance, as measured by the mean response time, can be calculated.Queue scheduling algorithms which improve the performance are considered.Single-module disk systems are analyzed, incorporating the SCAN scheduling algorithm suggested by Denning so that comparisons with the FIFO algorithm are possible.This analysis is extended to multimodule systems whereby tables of approximate glean response values time can be calculated over system parameters describing equipment characteristics, equipment configuration, system loading, file organization, and scheduling algorithm (SCAN or FIFO).The use of such tables is discussed and the applicability of the analysis to a recently marketed disk is noted.

A procedure for determining whether two graphs are isomorphic is described.During the procedure, from any given graph two graphs, the representative graph and the reordered graph, are derived.The representative graph is a homomorphic image of the original graph; the reordered graph is constructed from the representative graph to be isomorphic to the given graph.Unique labels are assigned to the vertices of both derived graphs.It follows that two representative graphs or two reordered graphs are isomorphic if and only if they are identical.A conjecture states that the representative graphs exhibit the automorphism partitioning of the given graph.The representative graphs form a necessity condition for isomorphism; namely, if the representative graphs are not identical, then the given graphs are not isomorphic.The converse is true for trees and follows from the conjecture for other types of graphs.It is also shown that the reordered graphs form a sufficiency condition for isomorphism; namely, if the reordered graphs are identical, then the given graphs are isomorphic.The converse follows from the conjecture.The time required to determine both derived graphs depends on a power of n, the order of the given graph.This power is a function of an adjacency property known as the strong regularity of the given graph.For graphs that do not contain a strongly regular transitive subgraph, the power is, at worst, five.

article Semantic Clustering of Index Terms Share on Author: S. Kumar University of Toronto, Department of Computer Science, Toronto, Ontario, Canada University of Toronto, Department of Computer Science, Toronto, Ontario, CanadaView Profile Authors Info & Claims Journal of the ACMVolume 15Issue 4Oct. 1968 pp 493–513https://doi.org/10.1145/321479.321480Published:01 October 1968 56citation797DownloadsMetricsTotal Citations56Total Downloads797Last 12 Months16Last 6 weeks1 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access

Background of the ProblemIn 1952 the Marketing Research Department of Imperial Oil Limited in Toronto undertook an investigation as to how to meet the rapidly increasing need for greater warehouse facilities across Canada.They decided that many of the problems could be solved by erecting a large central warehouse in Sarnia, next to the refinery, and maintaining in it a stock against which field warehouses could place orders, with a systematic control of the inventory in the central warehouse.It was estimated that this plan would not only avoid the much more expensive construction of many field warehouses, but would offer a substantial reduction of working capital tied up in inventory and a more rapid and complete filling of orders placed by the field warehouses.Further it was planned that the inventory control system would eventually be extended to and integrated with hundreds of field warehouses.Since the inventory control system and the central warehouse were both new features in distribution, it was felt that a test as to how they would operate would be of value.After discussion with the Computation Centre it was decided that this test should take the form of having FERt~r, the Ferranti high speed digital computer [1] at the University of Toronto, simulate the proposed warehouse with its inventory control and process the orders actually placed by the field warehouses during a selected period of 1953.The period chosen was September, October and November 1953, three months of almost peak activity when there would be some strain on the system.

article Free Access Share on Running a Computer Efficiently Author: C. C. Gotlieb University of Toronto, Ontario, Canada University of Toronto, Ontario, CanadaView Profile Authors Info & Claims Journal of the ACMVolume 1Issue 3July 1954 pp 124–127https://doi.org/10.1145/320776.320781Published:01 July 1954Publication History 5citation575DownloadsMetricsTotal Citations5Total Downloads575Last 12 Months20Last 6 weeks2 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF