11,261 research outputs found
An asynchronous distributed component model and its semantics
This paper is placed in the context of large scale distributed programming, providing a programming model based on asynchronous components. It focuses on the semantics of asynchronous invocations and component synchronisation. Our model is precise enough to enable the specification of a formal semantics. A variant of this model has been implemented, together with tools for managing components.
This paper explains why we consider that our component model is efficient and provides a convenient programming model. We show how futures play a major role for such asynchronous components, and provide a reduction semantics for the component model. This reduction semantics has been specified in the Isabelle theorem prover, and will be used to prove properties on the component model and its implementations
Habitability: CAMELOT 4
During 1988 to 1989 the NASA/USRA Advanced Design Program sponsored research and design efforts aimed at developing habitability criteria and at defining a habitability concept as a useful tool in understanding and evaluating dwellings for prolonged stays in extraterrestrial space. The Circulating Auto sufficient Mars-Earth Luxurious Orbital Transport (CAMELOT) was studied as a case in which the students would try to enhance the quality of life of the inhabitants by applying architectural design methodology. The study proposed 14 habitability criteria considered necessary to fulfill the defined habitability concept, which is that state of equilibrium that results from the interaction between components of the Individual Architecture Mission Complex, which allows a person to sustain physiological homeostatis, adequate performance, and acceptable social relationships. Architecture, design development, refinements and revisions to improve the quality of life, new insights on artificial gravity, form and constitution problems, and the final design concept are covered
Internal and relative motions of the Taurus and Ophiuchus star-forming regions
We investigate the internal and relative motions of the Taurus and Ophiuchus
star-forming regions using a sample of young stars with accurately measured
radial velocities and proper motions. We find no evidence for expansion or
contraction of the Taurus complex, but a clear indication for a global
rotation, resulting in velocity gradients, this suggests a common origin,
possibly related to that of Gould's Belt.Comment: 2 figure
Commensurate-Incommensurate Magnetic Phase Transition in Magnetoelectric Single Crystal LiNiPO
Neutron scattering studies of single-crystal LiNiPO reveal a spontaneous
first-order commensurate-incommensurate magnetic phase transition. Short- and
long-range incommensurate phases are intermediate between the high temperature
paramagnetic and the low temperature antiferromagnetic phases. The modulated
structure has a predominant antiferromagnetic component, giving rise to
satellite peaks in the vicinity of the fundamental antiferromagnetic Bragg
reflection, and a ferromagnetic component giving rise to peaks at small
momentum-transfers around the origin at . The wavelength of the
modulated magnetic structure varies continuously with temperature. It is argued
that the incommensurate short- and long-range phases are due to
spin-dimensionality crossover from a continuous to the discrete Ising state.
These observations explain the anomalous first-order transition seen in the
magnetoelectric effect of this system
Relaunching the Open Education Policy Registry
Post on OER World Map Blog providing an update on the development of the OE Policy Registry
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