Preliminary Design of the APIARY for VLSI Support of Knowledge-Based Systems

This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for the laboratory's artificial intelligence research is provided in part by the Office of Naval Research of the Department of Defense under Contract N00014-75-C-0522.Knowledge-based applications will require vastly increased computational resources to achieve their goals. We are working on the development of a VLSI Message Passing Architecture to meet this need. As a first step we present the preliminary design of the APIARY system in this paper. The APIARY is currently in an early stage of implementation at the MIT Artificial Intelligence Laboratory.MIT Artificial Intelligence Laboratory Department of Defense Office of Naval Researc

Using Message Passing Instead of the GOTO Construct

This report describes research conducted at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for this research was provided in part by the Office of Naval Research of the Department of Defense under Contract N00014-75-C-0522.This paper advocates a programming methodology using message passing. Efficient programs are derived for fast exponentiation, merging ordered sequences, and path existence determination in a directed graph. The problems have been proposed by John Reynolds as interesting ones to investigate because they illustrate significant issues in programming. The methodology advocated here is directed toward the production of programs that are intended to execute efficiently in a computing environment with many processors. The absence of the GOTO construct does not seem to be constricting in any respect in the development of efficient programs using the programming methodology advocated here.MIT Artificial Intelligence Laboratory Department of Defense Advanced Research Projects Agenc

Concurrent Systems Need Both Sequences And Serializers

This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for the laboratory's artificial intelligence research is provided in part by the Office of Naval Research of the Department of Defense under contract N00014-75-C-0522.Contemporary concurrent programming languages fall roughly into two classes. Languages in the first class support the notion of a sequence of values and some kind of pipelining operation over the sequence of values. Languages in the second class support the notion of transactions and some way to serialize transactions. In terms of the actor model of computation this distinction corresponds to the difference between serialized and unserialized actors. In this paper the utility of modeling both serialized and unserialized actors in a coherent formalism is demonstrated.MIT Artificial Intelligence Laboratory Department of Defense Office of Naval Researc

Evolutionary Programming with the Aid of A Programmers' Apprentice

This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for the laboratory's artificial intelligence research is provided in part by the Office of Naval Research of the Department of Defense under Contract N00014-75-C-0522.MIT Artificial Intelligence Laboratory Department of Defense Office of Naval Researc

Protection and Synchronization in Actor Systems

This paper presents a unified method [called ENCASING] for dealing with the closely related issues of synchronization and protection in actor systems [Hewitt et al. 1973a, 1973b, 1974a; Greif and Hewitt 1975]. Actors are a semantic concept in which no active process is ever allowed to treat anything as an object. Instead a polite request must be extended to accomplish what the activator [process] desires. Actors enable us to define effective and efficient protection schemes. Vulnerable actors can be protected before being passed out by ENCASING their behavior in a guardian which applies appropriate checks before invoking the protected actor. Protected actors can be freely passed out since they work only for actors which have the authority to use them where authority can be decided by an arbitrary procedure. Synchronization can be viewed as a [time-variant] kind of protection in which access is only allowed to the encased actor when it is safe to do so.MIT Artificial Intelligence Laborator

For Cybersecurity, Computer Science Must Rely on the Opposite of Gödel’s Results

This article shows how fundamental higher-order theories of mathematical structures of computer science (e.g. natural numbers [Dedekind 1888] and Actors [Hewitt et. al. 1973]) are cetegorical meaning that they can be axiomatized up to a unique isomorphism thereby removing any ambiguity in the mathematical structures being axiomatized. Having these mathematical structures precisely defined can make systems more secure because there are fewer ambiguities and holes for cyberattackers to exploit. For example, there are no infinite elements in models for natural numbers to be exploited. On the other hand, the 1st-order theories of Gödel’s results necessarily leave the mathematical structures ill-defined, e.g., there are necessarily models with infinite integers. Cyberattackers have severely damaged national, corporate, and individual security as well causing hundreds of billions of dollars of economic damage. A significant cause of the damage is that current engineering practices are not sufficiently grounded in theoretical principles. In the last two decades, little new theoretical work has been done that practically impacts large engineering projects with the result that computer systems engineering education is insufficient in providing theoretical grounding. If the current cybersecurity situation is not quickly remedied, it will soon become much worse because of the projected development of Scalable Intelligent Systems by 2025 [Hewitt 2019]. Gödel strongly advocated that the Turing Machine is the preeminent universal model of computation. A Turing machine formalizes an algorithm in which computation proceeds without external interaction. However, computing is now highly interactive, which this article proves is beyond the capability of a Turing Machine. Instead of the Turing Machine model, this article presents an axiomatization of a universal model of digital computation (including implementation of Scalable Intelligent Systems) up to a unique isomorphism

Computer Science Must Rely on Strongly-Typed Actors and Theories for Cybersecurity

International audience This article shows how fundamental higher-order theories of mathematical structures of computer science (e.g. natural numbers [Dedekind 1888] and Actors [Hewitt et. al. 1973]) are categorical meaning that they can be axiomatized up to a unique isomorphism thereby removing any ambiguity in the mathematical structures being axiomatized. Having these mathematical structures precisely defined can make systems more secure because there are fewer ambiguities and holes for cyberattackers to exploit. For example, there are no infinite elements in models for natural numbers to be exploited. On the other hand, the 1 st-order theories and computational systems which are not strongly-typed necessarily provide opportunities for cyberattack. Cyberattackers have severely damaged national, corporate, and individual security as well causing hundreds of billions of dollars of economic damage. [Sobers 2019] A significant cause of the damage is that current engineering practices are not sufficiently grounded in theoretical principles. In the last two decades, little new theoretical work has been done that practically impacts large engineering projects with the result that computer systems engineering education is insufficient in providing theoretical grounding. If the current cybersecurity situation is not quickly remedied, it will soon become much worse because of the projected development of Scalable Intelligent Systems by 2025 [Hewitt 2019]. Kurt Gödel strongly advocated that the Turing Machine is the preeminent universal model of computation. A Turing machine formalizes an algorithm in which computation proceeds without external interaction. However, computing is now highly interactive, which this article proves is beyond the capability of a Turing Machine. Instead of the Turing Machine model, this article presents an axiomatization of a strongly-typed universal model of digital computation (including implementation of Scalable Intelligent Systems) up to a unique isomorphism. Strongly-typed Actors provide the foundation for tremendous improvements in cyberdefense