2,672 research outputs found

    Study of application of space telescope science operations software for SIRTF use

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    The design and development of the Space Telescope Science Operations Ground System (ST SOGS) was evaluated to compile a history of lessons learned that would benefit NASA's Space Infrared Telescope Facility (SIRTF). Forty-nine specific recommendations resulted and were categorized as follows: (1) requirements: a discussion of the content, timeliness and proper allocation of the system and segment requirements and the resulting impact on SOGS development; (2) science instruments: a consideration of the impact of the Science Instrument design and data streams on SOGS software; and (3) contract phasing: an analysis of the impact of beginning the various ST program segments at different times. Approximately half of the software design and source code might be useable for SIRTF. Transportability of this software requires, at minimum, a compatible DEC VAX-based architecture and VMS operating system, system support software similar to that developed for SOGS, and continued evolution of the SIRTF operations concept and requirements such that they remain compatible with ST SOGS operation

    Specifying Logic Programs in Controlled Natural Language

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    Writing specifications for computer programs is not easy since one has to take into account the disparate conceptual worlds of the application domain and of software development. To bridge this conceptual gap we propose controlled natural language as a declarative and application-specific specification language. Controlled natural language is a subset of natural language that can be accurately and efficiently processed by a computer, but is expressive enough to allow natural usage by non-specialists. Specifications in controlled natural language are automatically translated into Prolog clauses, hence become formal and executable. The translation uses a definite clause grammar (DCG) enhanced by feature structures. Inter-text references of the specification, e.g. anaphora, are resolved with the help of discourse representation theory (DRT). The generated Prolog clauses are added to a knowledge base. We have implemented a prototypical specification system that successfully processes the specification of a simple automated teller machine.Comment: 16 pages, compressed, uuencoded Postscript, published in Proceedings CLNLP 95, COMPULOGNET/ELSNET/EAGLES Workshop on Computational Logic for Natural Language Processing, Edinburgh, April 3-5, 199

    Complexity in Second Language Study Emotions

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    This book offers a socially situated view of the emergence of emotionality for additional language (L2) learners in classroom interaction in Japan. Grounded in a complexity perspective, the author argues that emotions need to be studied as they are dynamically experienced and understood in all of their multidimensional colors by individuals (in interaction). Via practitioner research, Sampson applies a small-lens focus, interweaving experiential and discursive data, offering possibilities for exploring, interpreting and representing the lived experience of L2 study emotions in a more holistic yet detailed, social yet individual fashion. Amidst the currently expanding interest in L2 study emotions, the book presents a strong case for the benefits of locating interpretations of the emergence of L2 study emotions back into situated, dynamic, social context. Sampson’s work will be of interest to students and researchers in second language acquisition and L2 learning psychology

    Conference on the Programming Environment for Development of Numerical Software

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    Systematic approaches to numerical software development and testing are presented

    Transportable educational programs for scientific and technical professionals: More effective utilization of automated scientific and technical data base systems

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    This grant final report executive summary documents a major, long-term program addressing innovative educational issues associated with the development, administration, evaluation, and widespread distribution of transportable educational programs for scientists and engineers to increase their knowledge of, and facilitate their utilization of automated scientific and technical information storage and retrieval systems. This educational program is of very broad scope, being targeted at Colleges of Engineering and Colleges of Physical sciences at a large number of colleges and universities throughout the United States. The educational program is designed to incorporate extensive hands-on, interactive usage of the NASA RECON system and is supported by a number of microcomputer-based software systems to facilitate the delivery and usage of the educational course materials developed as part of the program

    Structure and Problem Hardness: Goal Asymmetry and DPLL Proofs in<br> SAT-Based Planning

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    In Verification and in (optimal) AI Planning, a successful method is to formulate the application as boolean satisfiability (SAT), and solve it with state-of-the-art DPLL-based procedures. There is a lack of understanding of why this works so well. Focussing on the Planning context, we identify a form of problem structure concerned with the symmetrical or asymmetrical nature of the cost of achieving the individual planning goals. We quantify this sort of structure with a simple numeric parameter called AsymRatio, ranging between 0 and 1. We run experiments in 10 benchmark domains from the International Planning Competitions since 2000; we show that AsymRatio is a good indicator of SAT solver performance in 8 of these domains. We then examine carefully crafted synthetic planning domains that allow control of the amount of structure, and that are clean enough for a rigorous analysis of the combinatorial search space. The domains are parameterized by size, and by the amount of structure. The CNFs we examine are unsatisfiable, encoding one planning step less than the length of the optimal plan. We prove upper and lower bounds on the size of the best possible DPLL refutations, under different settings of the amount of structure, as a function of size. We also identify the best possible sets of branching variables (backdoors). With minimum AsymRatio, we prove exponential lower bounds, and identify minimal backdoors of size linear in the number of variables. With maximum AsymRatio, we identify logarithmic DPLL refutations (and backdoors), showing a doubly exponential gap between the two structural extreme cases. The reasons for this behavior -- the proof arguments -- illuminate the prototypical patterns of structure causing the empirical behavior observed in the competition benchmarks

    Considerations on command and response language features for a network of heterogeneous autonomous computers

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    The design of a uniform command language to be used in a local area network of heterogeneous, autonomous nodes is considered. After examining the major characteristics of such a network, and after considering the profile of a scientist using the computers on the net as an investigative aid, a set of reasonable requirements for the command language are derived. Taking into account the possible inefficiencies in implementing a guest-layered network operating system and command language on a heterogeneous net, the authors examine command language naming, process/procedure invocation, parameter acquisition, help and response facilities, and other features found in single-node command languages, and conclude that some features may extend simply to the network case, others extend after some restrictions are imposed, and still others require modifications. In addition, it is noted that some requirements considered reasonable (user accounting reports, for example) demand further study before they can be efficiently implemented on a network of the sort described

    An information adaptive system study report and development plan

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    The purpose of the information adaptive system (IAS) study was to determine how some selected Earth resource applications may be processed onboard a spacecraft and to provide a detailed preliminary IAS design for these applications. Detailed investigations of a number of applications were conducted with regard to IAS and three were selected for further analysis. Areas of future research and development include algorithmic specifications, system design specifications, and IAS recommended time lines
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