Showing papers on "Service (systems architecture) published in 1971"

PRIME: a modular architecture for terminal-oriented systems

Abstract: The architecture of most interactive systems is based on the general strategy that suitable terminal service can be provided by a central processor that is timemultiplexed among all the active terminals. In order to achieve adequate response time in an interactive environment, the CPU is usually time sliced. Other major system facilities such as I/O channels and secondary storage units are also shared among the users, and multiprogramming techniques are employed to keep all the major system resources as fully utilized as possible. An operating system is usually developed which performs these functions as well as supervising the terminal communications, implementing a system-wide filing subsystem, handling user commands, etc. The result of combining these and other functions into a time-sharing operating system is a highly complex software system which transforms what is basically a batch processing computer structure into a multi-terminal system with significant limitations that are an outgrowth of this strategy. While a failure can occur in any section of the hardware or software, we know that hardware failures are more likely to occur in the electromechanical and core memory sectors than in solid state logic, and that software failures tend to be concentrated in the more complex areas of code. Failures of hardware components may require modification of the operating system in order to regain operational status since the allocation strategies may need more than parametric modification when system resources are affected.

Functional Specification of Call Processing by State Transition Diagram

Abstract: Functional specification of call processing in a telephone switching system became more complicated with the progress of common control systems, especially of stored program controlled electronic switching systems, which enabled the introduction of new service features. One approach by state transition diagram that is now widely adopted in Japan is explained and discussed. Since a telephone switching system is one of the sequential machines, the state transition concept is applied to describe its functions. States are assigned to calls and an exact state transition concept is somewhat modified to meet the switching needs. Rules for writing a diagram and decomposition of states for reduction and simplification of states are some of the topics discussed. The results gained from actual application to local and toll switching systems are also shown.

The basic: service categorisation in planning

Abstract: Massey D. B. (1973) The basic: service categorization in planning, Reg. Studies 7, 1–15. This paper aims to clarify and evaluate in a planning and policy-making context the concept of the categorization of a region's industry into basic and service. It is pointed out that the categorization is used in a number of different frameworks, and that the criteria for definition in each of these are sometimes confused. The two major sets of criteria—locational characteristics and export base theory—are then evaluated, first in a standard theoretical manner, secondly in a technical/operational context (that of the Lowry model), and lastly in a specifically policy-oriented context. The aim is to illustrate three potential levels of inadequacy or bias. The first two, theoretical shortcomings and difficulties of practical implementation, are discussed with emphasis on their important feedback relationship: decisions made to ease practical application affect theoretical implications. At the third level, there is an at...

A second survey of users' views of discrete simulation languages by

Abstract: This simulation language survey is a followup of the survey published in SIMULATION, in May 1970, p. 225. The previous report generated much inter est, criticism pro and con, and most importantly some additional responses. Consequently the responses summarized below, including the 30 re sponses from the original survey, now total 103. Responses were solicited by direct request, the generous efforts of others (notably Ira Key of Southern Simulation Service, Inc.), and a "Dear John" letter published in the October 1970 issue of SIMULATION.

Programming in the Cooperative Extension Service: A Conceptual Schema.

Abstract: MF-$0.65 HC-$3.29 Agricultural Education; Behavioral Objectives; Behavior Change; Behavior Patterns; *Change Agents; Conceptual Schemes; Coordination; Educational Accountability; Educational Planning; *Extension Agents; Interpersonal Competence; Program Design; *Programing; *Rural Extension; Social Systems;

Scientific Information by Computer

Abstract: An evaluation of the Chemical Society's Chemical Titles information retrieval service compared with a parallel manual search of the literature has shown that, at least in certain disciplines, more than 90 per cent of the desired information can be obtained. This is quite adequate for most commercial and scientific purposes.

The Data Reconfiguration Service: An Experiment in Adaptable, Process

Abstract: Describes the Data Reconfiguration Service (DRS) now being implemented at MIT, UCLA, UCSB and RAND for the ARPA computing network.

A new M.I.T. graduate course: Analysis of urban service systems

Abstract: This paper summarizes a new graduate course focusing on an area of very recent quantitative research: urban service systems (e.g., police and fire departments, emergency ambulance services, mass transit systems). At one level the course presents a unified study of geometrical probability, multiserver queuing theory, spatial location theory, scheduling and sequencing techniques, and relevant methods of simulation. At a second level students are asked to structure a comprehensive quantitative approach to a set of problems actually experienced by one agency, entailing interaction with the agency. This paper reviews the course as taught in the 1971 Spring Term and discusses applications in evaluating various types of urban technology.

Tall Buildings - A Technological Assessment

Abstract: The systems, criteria, and concepts involved in the current ASCE-IABSE sponsored project at Lehigh University on the Planning and Design of Tall Buildings are described. Details of the objectives, scope, and organization of this entire project, which is international in character, are presented. From a series of regional and national meetings, as well as planned international conferences, and from the output of some 27 technical committees, material will be developed for eventual reference monographs or manuals for design professionals and decision makers. The broad interdisciplinary approach used is illustrated by a description of the environmental, service, structural, construction, and materials systems considered in the broad systems approach to the project.

A reexamination: Centralized versus decentralized computers in biomedical environments

Abstract: We feel that, rather than asking whether biomedical investigators should be supported by centralized or decentralized computers, we should ask how investigators may be given effective access to the various kinds of computing service they require. Optimality of a computer configuration cannot be meaningfully assessed apart from the job-mix priorities it is to serve. It is difficult to think of an area of application wherein requirements would differ more from location to location than in biomedical computing. What is good for control of on-line experiments in a physiological laboratory would tend to be inefficient or altogether inadequate for processing the major statistical computations widely encountered in biology and medicine. Conversely, it would usually be uneconomical to tie up a system well suited to statistical computations for continual monitoring of experiments. Not only do we find a spectrum of biologists whose requirements range from control of experiments to complex modeling and statistical analysis, we also find the entire spectrum represented in the work of a single investigator—often, in fact, in a single study. Thus, after preliminary reduction by the laboratory computer, the neurophysiologist's data may require major statistical analysis. In fact, it is likely that occasional bursts of such major support during the course of an experiment might be desired for more sophisticated guidance of the experiment.