The Tyranny of the Vital Few: The Pareto Principle in Language Design

Modern high-level programming languages often contain constructs whose semantics are non-trivial. In practice how- ever, software developers generally restrict the use of such constructs to settings in which their semantics is simple (programmers use language constructs in ways they understand and can reason about). As a result, when developing tools for analyzing and manipulating software, a disproportionate amount of effort ends up being spent developing capabilities needed to analyze constructs in settings that are infrequently used. This paper takes the position that such distinctions between theory and practice are an important measure o f the analyzability of a language

Programming errors in traversal programs over structured data

Traversal strategies \'a la Stratego (also \'a la Strafunski and 'Scrap Your Boilerplate') provide an exceptionally versatile and uniform means of querying and transforming deeply nested and heterogeneously structured data including terms in functional programming and rewriting, objects in OO programming, and XML documents in XML programming. However, the resulting traversal programs are prone to programming errors. We are specifically concerned with errors that go beyond conservative type errors; examples we examine include divergent traversals, prematurely terminated traversals, and traversals with dead code. Based on an inventory of possible programming errors we explore options of static typing and static analysis so that some categories of errors can be avoided. This exploration generates suggestions for improvements to strategy libraries as well as their underlying programming languages. Haskell is used for illustrations and specifications with sufficient explanations to make the presentation comprehensible to the non-specialist. The overall ideas are language-agnostic and they are summarized accordingly

Seventh Annual Workshop on Space Operations Applications and Research (SOAR 1993), volume 1

This document contains papers presented at the Space Operations, Applications and Research Symposium (SOAR) Symposium hosted by NASA/Johnson Space Center (JSC) on August 3-5, 1993, and held at JSC Gilruth Recreation Center. SOAR included NASA and USAF programmatic overview, plenary session, panel discussions, panel sessions, and exhibits. It invited technical papers in support of U.S. Army, U.S. Navy, Department of Energy, NASA, and USAF programs in the following areas: robotics and telepresence, automation and intelligent systems, human factors, life support, and space maintenance and servicing. SOAR was concerned with Government-sponsored research and development relevant to aerospace operations. More than 100 technical papers, 17 exhibits, a plenary session, several panel discussions, and several keynote speeches were included in SOAR '93

A formal framework for specification-based embedded real-time system engineering

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2008.Includes bibliographical references (v. 2, p. 517-545).The increasing size and complexity of modern software-intensive systems present novel challenges when engineering high-integrity artifacts within aggressive budgetary constraints. Among these challenges, ensuring confidence in the engineered system, through validation and verification activities, represents the high cost item on many projects. The expensive nature of engineering high-integrity systems using traditional approaches can be partly attributed to the lack of analysis facilities during the early phases of the lifecycle, causing the validation and verification activities to begin too late in the engineering lifecycle. Other challenges include the management of complexity, opportunities for reuse without compromising confidence, and the ability to trace system features across lifecycle phases. The use of models as a specification mechanism provides an approach to mitigate complexity through abstraction. Furthermore, if the specification approach has formal underpinnings, the use of models can be leveraged to automate engineering activities such as formal analysis and test case generation. The research presented in this thesis proposes an engineering framework which addresses the high cost of validation and verification activities through specification-based system engineering. More specifically, the framework provides an integrated approach to embedded real-time system engineering which incorporates specification, simulation, formal verification, and test-case generation. The framework aggregates the state-of-the-art in individual software engineering disciplines to provide an end-to-end approach to embedded real-time system engineering. The key aspects of the framework include: * A novel specification language, the Timed Abstract State Machine (TASM) language, which extends the theory of Abstract State Machines (ASM).(cont.) The TASM language is a literate formal specification language which can be applied and multiple levels of abstraction and which can express the three key aspects of embedded real-time systems - function, time, and resources. * Automated verification capabilities achieved through the integration of mature analysis engines, namely the UPPAAL tool suite and the SAT4J SAT solver. The verification capabilities provided by the framework include completeness and consistency verification, model checking, execution time analysis, and resource consumption analysis. * Bi-directional traceability of model features across levels of abstraction and lifecycle phases. Traceability is achieved syntactically through archetypical refinement types; each refinement type provides correctness criteria, which, if met, guarantee semantic integrity through the refinement. * Automated test case generation capabilities for unit testing, integration testing, and regression testing. Unit test cases are generated to achieve TASM specification coverage through the rule coverage criterion. Integration test case generation is achieved through the hierarchical composition of unit test cases. Regression test case generation is achieved by leveraging the bi-directional traceability of model features. The framework is implemented into an integrated tool suite, the TASM toolset, which incorporates the UPPAAL tool suite and the SAT4J SAT solver. The toolset and framework are evaluated through experimentation on three industrial case studies - an automated manufacturing system, a "drive-by-wire" system used at a major automotive manufacturer, and a scripting environment used on the International Space Station.by Martin Ouimet.Ph.D

Second Conference on Artificial Intelligence for Space Applications

The proceedings of the conference are presented. This second conference on Artificial Intelligence for Space Applications brings together a diversity of scientific and engineering work and is intended to provide an opportunity for those who employ AI methods in space applications to identify common goals and to discuss issues of general interest in the AI community

Third International Symposium on Artificial Intelligence, Robotics, and Automation for Space 1994

The Third International Symposium on Artificial Intelligence, Robotics, and Automation for Space (i-SAIRAS 94), held October 18-20, 1994, in Pasadena, California, was jointly sponsored by NASA, ESA, and Japan's National Space Development Agency, and was hosted by the Jet Propulsion Laboratory (JPL) of the California Institute of Technology. i-SAIRAS 94 featured presentations covering a variety of technical and programmatic topics, ranging from underlying basic technology to specific applications of artificial intelligence and robotics to space missions. i-SAIRAS 94 featured a special workshop on planning and scheduling and provided scientists, engineers, and managers with the opportunity to exchange theoretical ideas, practical results, and program plans in such areas as space mission control, space vehicle processing, data analysis, autonomous spacecraft, space robots and rovers, satellite servicing, and intelligent instruments