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SELMA: A Conversational System for the Graphical Specification of Markovian Queueing Networks

IP.com Disclosure Number: IPCOM000128425D
Original Publication Date: 1969-Oct-01
Included in the Prior Art Database: 2005-Sep-15

Publishing Venue

Software Patent Institute

Related People

Jackson, James H.: AUTHOR [+3]

Abstract

This report discusses the design and use of the Systems Engineering Laboratory's Markovian Analyzer (SELMA) system for a DEC 339 computer display terminal. This system provides interactive graphics support for a program which was developed concurrently for the IBM 360/67 to analyze a class of Markovian queueing networks. Special features of the system include handling of all graphic operations at the terminal and recognition of patterns of motion of the light pen to provide a human-oriented drawing capability.

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THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

SELMA: A Conversational System for the Graphical Specification of Markovian Queueing Networks

THE UNIVERSITY OF MICHIGAN Technical Report 23 James H. Jackson

CONCOMP: Research in Conversational Use of Computers
F. H. Westervelt, Director ORA Project 07449

supported by: ADVANCED RESEARCH PROJECTS AGENCY DEPARTMENT OF DEFENSE WASHINGTON, D. C.

CONTRACT NO. DA-49-083 OSA-3050 ARPA ORDER NO. 716

administered through: OFFICE OF RESEARCH ADMINISTRATION ANN ARBOR

October 1969

ABSTRACT

This report discusses the design and use of the Systems Engineering Laboratory's Markovian Analyzer (SELMA) system for a DEC 339 computer display terminal. This system provides interactive graphics support for a program which was developed concurrently for the IBM 360/67 to analyze a class of Markovian queueing networks. Special features of the system include handling of all graphic operations at the terminal and recognition of patterns of motion of the light pen to provide a human-oriented drawing capability.

TABLE OF CONTENTS

Abstract.....iii
1. Introduction.....1
2. Usage of SELMA and QAS.....5
3. The Command Exchanger......40
4. The Display Structure......61
5. Special Command Exchanger Feature......69
6. Foreseeable Modifications......71
References.....73

LIST OF FIGURES

University of Michigan Page 1 Oct 01, 1969

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SELMA: A Conversational System for the Graphical Specification of Markovian Queueing Networks

Figure 1. Simplified SELMA Structure.....2
Figure 2. SELMA Phases.....6
a. Construction Phase 6
b. Results Phase 6
c. Plot Phase.....7
Figure 3. Phase Transitions.....8
Figure 4. Element Symbols.....10
Figure 5. Threshold Pattern for Light Pen Motion Recognition.....12
Figure 6. Light Pen Motion on Unconnected Element Symbols.....13
a. Threshold Patterns About a Symbol.....13
b. Deleting a Symbol.....13
c. Moving a Symbol.....13
Figure 7. Drawing a Connection Line.....15
a. Start of Connection Line at Output Port.....15
b. After First Corner.....15
c. After Second Corner.....16
Figure 8. Examples of Branches and Merges.....20
a. Random Branch 20
b. Priority Branch 20
c. Random Merge.....21
d. Priority Merge.....21
Figure 9. Threshold Patterns for Generating Branches.....23
Figure 10. Generation of Branches.....24
a. Random Branch 24
b. Priority Branch 24

Figure 11. Threshold Patterns for Generating Merges.....26
Figure 12. Generation of Merges.....27
a. Random Merge.....27
b. Priority Merge.....27
Figure 13. Identification of an Element.....31
Figure 14. Result Plot for Model in Figure 13.....33
a. Before Graph is Returned from QAS.....33
b. After Graph is Returned from QAS.....33
Figure 15. Modification of a Result Plot 35
a. Display of Numerical Values.....35
b-. Expansion of a Section of the Graph.....35
Figure 16. Command Format.....42
Figure 17. Commands Accepted by QAS......43
Figure 18. Commands Accepted by SELMA.....44
Figure 19. Typical Construction of a Model.....5...