Spacecraft command verification: The AI solution

Recently, a knowledge-based approach was used to develop a system called the Command Constraint Checker (CCC) for TRW. CCC was created to automate the process of verifying spacecraft command sequences. To check command files by hand for timing and sequencing errors is a time-consuming and error-prone task. Conventional software solutions were rejected when it was estimated that it would require 36 man-months to build an automated tool to check constraints by conventional methods. Using rule-based representation to model the various timing and sequencing constraints of the spacecraft, CCC was developed and tested in only three months. By applying artificial intelligence techniques, CCC designers were able to demonstrate the viability of AI as a tool to transform difficult problems into easily managed tasks. The design considerations used in developing CCC are discussed and the potential impact of this system on future satellite programs is examined

Development of a KSC test and flight engineering oriented computer language, Phase 1

Ten, primarily test oriented, computer languages reviewed during the phase 1 study effort are described. Fifty characteristics of ATOLL, ATLAS, and CLASP are compared. Unique characteristics of the other languages, including deficiencies, problems, safeguards, and checking provisions are identified. Programming aids related to these languages are reported, and the conclusions resulting from this phase of the study are discussed. A glossary and bibliography are included. For the reports on phase 2 of the study, see N71-35027 and N71-35029

GPERF : a perfect hash function generator

gperf is a widely available perfect hash function generator written in C++. It automates a common system software operation: keyword recognition. gperf translates an n element user-specified keyword list keyfile into source code containing a k element lookup table and a pair of functions, phash and in_word_set. phash uniquely maps keywords in keyfile onto the range 0 .. k - 1, where k >/= n. If k = n, then phash is considered a minimal perfect hash function. in_word_set uses phash to determine whether a particular string of characters str occurs in the keyfile, using at most one string comparison.This paper describes the user-interface, options, features, algorithm design and implementation strategies incorporated in gperf. It also presents the results from an empirical comparison between gperf-generated recognizers and other popular techniques for reserved word lookup

Achieving Obfuscation Through Self-Modifying Code: A Theoretical Model

With the extreme amount of data and software available on networks, the protection of online information is one of the most important tasks of this technological age. There is no such thing as safe computing, and it is inevitable that security breaches will occur. Thus, security professionals and practices focus on two areas: security, preventing a breach from occurring, and resiliency, minimizing the damages once a breach has occurred. One of the most important practices for adding resiliency to source code is through obfuscation, a method of re-writing the code to a form that is virtually unreadable. This makes the code incredibly hard to decipher by attackers, protecting intellectual property and reducing the amount of information gained by the malicious actor. Achieving obfuscation through the use of self-modifying code, code that mutates during runtime, is a complicated but impressive undertaking that creates an incredibly robust obfuscating system. While there is a great amount of research that is still ongoing, the preliminary results of this subject suggest that the application of self-modifying code to obfuscation may yield self-maintaining software capable of healing itself following an attack

Learning Languages and Complex Subjects with Memory Palaces

A memory palace is an ancient technique of using space as a way of organizing memories. It’s a powerful tool for learning, retaining, and recalling large amounts of complex information quickly and effectively. In the middle ages, these techniques were widely used to learn and compose large texts and works of literature. In this paper, we present the fundamental theory behind memory palaces as the foundation for the project Macunx - a VR platform for building memory palaces to learn huge amounts in short time and with full retention - as well as the initial stages of its development. The paper concludes with a discussion of the future stages over the testing of the package with end-users for its final refinement

Programming languages: a brief review

In this article we review the development of programming languages and classify them based on their structures and their applications

Speech Communication

Contains research objectives, summary of research and reports on three research projects.U. S. Air Force Cambridge Research Laboratories under Contract F19628-69-C-0044National Institutes of Health (Grant 5 R01 NS04332-09)M.I.T. Lincoln Laboratory Purchase Order CC-57