Truth Maintenance

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Full Text: https://apps.dtic.mil/sti/pdfs/ADA432150.pdf

Temporal Reasoning and Truth Maintenance

Full Text: https://apps.dtic.mil/sti/pdfs/ADA245600.pdf
Accession Number:  ADA245600
Title:  Data Fusion: Temporal Reasoning and Truth Maintenance
Descriptive Note: Final rept.
Corporate Author: FYSISCH EN ELEKTRONISCH LAB TNO THE HAGUE (NETHERLANDS)
Personal Author(s):  Kenne, A. P. ; Perre, M. 
Report Date:  1991-11-01
Pagination or Media Count: 101.0 

Abstract: 

This report contains a survey of two techniques that can be used in the field of data fusion temporal reasoning and truth maintenance. The automatic fusion of intelligence reports necessitates taking into account the factor time. Incoming messages can lead to new interpretations of the current battlefield situation, changing previously made hypotheses. A data fusion system must also be able to make a prediction of what sightings are to be expected, e. g. in the case of columns of vehicles moving past different sensors. This report describes a temporal database system that can capture some part of the volatility of the intelligence processing domain. While processing intelligence reports there is always an amount of uncertainty and incompleteness that has to be dealt with. So there is a need for maintaining different lines of reasoning or hypotheses pertaining to the battlefield situation concurrently, and incorporating new information as it becomes available. In this report an assumption-based truth maintenance system provides a framework in which this problem can be solved. A prototype has been developed to demonstrate the applicability of the aforementioned techniques. This prototype, called Mefisto Modular Environment for Fusion and Interpretation of Sensor data in Tracking Opposing forces, is a simple knowledge-based system integrated with in temporal truth maintenance facility.

Descriptors: 
*MAINTENANCE ;
DATA PROCESSING ;
UNCERTAINTY ;
INTELLIGENCE ;
ENVIRONMENTS ;
DETECTORS ;
INFORMATION SYSTEMS ;
BATTLEFIELDS ;
PROCESSING ;
REPORTS ;
TRACKING ;
MODULAR CONSTRUCTION ;
TIME ;
SURVEYS ;
KNOWLEDGE BASED SYSTEMS ;
HYPOTHESES 
 
Subject Categories: Computer Programming and Software; Computer Systems

Distribution Statement: APPROVED FOR PUBLIC RELEASE

Three Valued Truth Maintenance

from: https://apps.dtic.mil/docs/citations/ADA062176
Accession Number : ADA062176
Title :   A Three Valued Truth Maintenance System.
Descriptive Note : Memorandum rept.,
Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE ARTIFICIAL INTELLIGENCE LAB
Personal Author(s) : McAllester,David A 
Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a062176.pdf
Report Date : May 1978
Pagination or Media Count : 32
Abstract : Truth maintenace systems have been used in recently developed problem solving systems. A truth maintenance system (TMS) is designed to be used by deductive systems to maintain the logical relations among the beliefs which those systems manipulate. These relations are used to incrementally modify the belief structure when premises are changed, giving a more flexible context mechanism than has been present in earlier artificial intelligence systems. The relations among beliefs can also be used to directly trace the source of contradictions or failures, resulting in far more efficient backtracking. In this paper a new approach is taken to truth maintenance algorithms. Each belief, or proposition, can be in any one of three truth states, true, false, or unknown. The relations among propositions are represented in disjunctive classes. By representing an implication in a clause the same algorithm that is used to deduce its consequent can be used to deduce the negation of antecedents that would lead to contradictions. A simple approach is also taken to the handling of assumptions and back tracking which does not involve the non-monotonic dependency structures present in other truth maintenance systems. (Author)

Descriptors :    *MAINTENANCE , *PROBLEM SOLVING , *RELIABILITY , *ARTIFICIAL INTELLIGENCE , ALGORITHMS , SIMULATION , FAILURE
Subject Categories : Mfg & Industrial Eng & Control of Product Sys
      Bionics
Distribution Statement : APPROVED FOR PUBLIC RELEASE