2,434 research outputs found

    A test matrix sequencer for research test facility automation

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    The hardware and software configuration of a Test Matrix Sequencer, a general purpose test matrix profiler that was developed for research test facility automation at the NASA Lewis Research Center, is described. The system provides set points to controllers and contact closures to data systems during the course of a test. The Test Matrix Sequencer consists of a microprocessor controlled system which is operated from a personal computer. The software program, which is the main element of the overall system is interactive and menu driven with pop-up windows and help screens. Analog and digital input/output channels can be controlled from a personal computer using the software program. The Test Matrix Sequencer provides more efficient use of aeronautics test facilities by automating repetitive tasks that were once done manually

    Living with dams: Managing the environmental impacts

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    Agricultural water management in a water stressed catchment: Lessons from the RIPARWIN Project

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    irrigation management / water stress / river basins / water rights / water fees / water allocation / irrigation efficiency / economic aspects / decision support tools / wetlands / water use / water users associations

    Alaska Native Culture and History, edited by Yoshinobu Kotani and William B. Workman

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    The Nature of Thule Eskimo Whale Use

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    Archaeologists for the past half century have considered bowhead whaling to be an important and integral part of Thule Eskimo subsistence. This position has come into question recently. Arguments are set forth favoring the predominant archaeological view that bowheads were hunted and extensively used during the period A.D. 1000-1300 in much of the Canadian Arctic. Direct, indirect, and circumstantial evidence is outlined, ranging from the presence of whaling gear and graphic whaling depictions to arguments of resource maximization and ample storage capacity at Thule winter sites. Differences in interpreting the Thule record appear to reflect different methodological approaches of ethnologists and archaeologists

    Stackless Multi-Threading for Embedded Systems

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    Programming support for multi-threaded applications on embedded microcontroller platforms has attracted a considerable amount of research attention in the recent years. This paper is focused on this problem, and presents UnStacked C, a source-to-source transformation that can translate multithreaded programs written in C into stackless continuations. The transformation can support legacy code by not requiring any changes to application code; only the underlying threading library needs modifications. We describe the details of UnStacked C in the context of the TinyOS operating system for wireless sensor network applications. We present a modified implementation of the TOSThreads library for TinyOS, and show how existing applications programmed using TOSThreads can be automatically transformed to use stackless threads with only modifications in the build process. By eliminating the need to allocate individual thread stacks and by supporting lazy thread preemption, UnStacked C enables a considerable saving of memory used and power consumed, respectively

    Grassland Technology Interaction and Policy Evolution in Canada

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    Canada is the world\u27s second largest country covering approximately 10 million km2 (McCartney & Horton, 1997). About 90% of Canada is uninhabited with 90 percent of Canadians living within 500 km of the American border. The forage resources used by livestock grazing and the production of forage crops covers over 36 million ha of Canada\u27s land base (3.6%) and is divided into 72% native range (26 million ha), 11% cultivated pastures (4 million ha) and 17% forage crops (6 million ha) There are 25 million ha in grain and oilseed crops (McCartney & Horton, 1997)
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