• "The first revolution is when you change your mind
    about how you look at things
    and see that there might be another way to look at it
    that you have not been shown."

    --Gil Scott-Heron, "The Revolution Will Not Be Televised"
  • Updated on 28 June 2018 at 9:46 am

    Real-Time for the Real World

    E. Douglas Jensen

    Work-in-progress preview of a work-in-progress book:

    Introduction to Fundamentals of Timeliness
    in Dynamically Real-Time Systems
    [Jensen 2018]



    Informally, a system is a “real-time” one if its core properties of timeliness and predictability of timeliness are integral to its logic, not only performance measures. In general, those properties are dynamic due primarily to intrinsic epistemic uncertainties—e.g., ignorance, inaccuracy, non-determinism—in the system and its application environment. Despite such uncertainties, dynamically real-time systems have multiple application-specific kinds and degrees of criticality—including even the most extreme safety-critical systems (e.g., for warfare). Traditional real-time computing systems are a special case whose core properties are predominately static and presumed to be known á priori, thus greatly limiting those systems’ applicability. Many dynamically real-time systems exist, built by application domain experts outside the real-time field, but without the benefits of a coherent foundation for real-time per se. The design, implementation, and application of real-time systems can be extended and strengthened by creating such a foundation based on principles for those core properties. This book introduces one approach to that. Timeliness is dynamically expressive using time/utility functions. Uncertainty of timeliness predictability can be reasoned about using various mathematical theories of evidence (belief functions). The foundation has been successfully employed in different real-time contexts having wickedly dynamic core properties, where traditional static real-time perspectives and techniques were insufficient.


    N.B. There still are pages from the previous (c. 2008-2012) version of this site which I have not yet updated and integrated (or removed).

    Next: Introduction

    About Me

    E. Douglas Jensen is a well-known pioneer and thought leader in real-time and distributed real-time systems–especially dynamic ones. His professional accomplishments have been in Innovative industria
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    This is a work-in-progress, highly condensed and less formal, preview of my work-in-progress book An Introduction to Fundamental Principles of Timeliness in Dynamically Real-Time Systems [Jensen 2018].
    Read more