131,539 research outputs found
Reduced gravity fecal collector seat and urinal
A waste collection system for use in a reduced gravity including a seat having an opening centrally located with a pair of opposed depressed valleys on opposite sides of said opening for accommodating the ischial tuberosities of a user. The seat has contoured surfaces for providing support of the user's body and includes a prominent ridge towards the rear, which provides forward-aft positioning cue to the user. A curved recess is provided adjacent the forward portion of the seat for accommodating a tubular urinal having an enlarged open mouth
Safety management of complex research operators
Complex research and technology operations present varied potential hazards which are addressed in a disciplined, independent safety review and approval process. Potential hazards vary from high energy fuels to hydrocarbon fuels, high pressure systems to high voltage systems, toxic chemicals to radioactive materials and high speed rotating machinery to high powered lasers. A Safety Permit System presently covers about 600 potentially hazardous operations. The Safety Management Program described is believed to be a major factor in maintaining an excellent safety record
Water-resource records of Brevard County, Florida
The U. S. Geological Survey made a comprehensive
investigation of the water resources of Brevard County
from 1954 to 1958. The purposes of this investigation were:
(1) to determine the occurrence and chemical quality of
water in the streams and lakes, (2) to determine the location
and the thickness of aquifers, and (3) to determine the
occurrence and chemical quality of the ground water. During
the period from 1933 to 1954, water records were collected
from a few stream-gaging stations and a few observation
wells. The purpose of this report is to present basic data
collected during these investigations. (Document has 188 pages.
The Microcanonical Functional Integral. I. The Gravitational Field
The gravitational field in a spatially finite region is described as a
microcanonical system. The density of states is expressed formally as a
functional integral over Lorentzian metrics and is a functional of the
geometrical boundary data that are fixed in the corresponding action. These
boundary data are the thermodynamical extensive variables, including the energy
and angular momentum of the system. When the boundary data are chosen such that
the system is described semiclassically by {\it any} real stationary
axisymmetric black hole, then in this same approximation is shown to
equal 1/4 the area of the black hole event horizon. The canonical and grand
canonical partition functions are obtained by integral transforms of that
lead to "imaginary time" functional integrals. A general form of the first law
of thermodynamics for stationary black holes is derived. For the simpler case
of nonrelativistic mechanics, the density of states is expressed as a real-time
functional integral and then used to deduce Feynman's imaginary-time functional
integral for the canonical partition function.Comment: 29 pages, plain Te
Modular Autoencoders for Ensemble Feature Extraction
We introduce the concept of a Modular Autoencoder (MAE), capable of learning
a set of diverse but complementary representations from unlabelled data, that
can later be used for supervised tasks. The learning of the representations is
controlled by a trade off parameter, and we show on six benchmark datasets the
optimum lies between two extremes: a set of smaller, independent autoencoders
each with low capacity, versus a single monolithic encoding, outperforming an
appropriate baseline. In the present paper we explore the special case of
linear MAE, and derive an SVD-based algorithm which converges several orders of
magnitude faster than gradient descent.Comment: 18 pages, 8 figures, to appear in a special issue of The Journal Of
Machine Learning Research (vol.44, Dec 2015
Nuclear reactor descriptions for space power systems analysis
For the small, high performance reactors required for space electric applications, adequate neutronic analysis is of crucial importance, but in terms of computational time consumed, nuclear calculations probably yield the least amount of detail for mission analysis study. It has been found possible, after generation of only a few designs of a reactor family in elaborate thermomechanical and nuclear detail to use simple curve fitting techniques to assure desired neutronic performance while still performing the thermomechanical analysis in explicit detail. The resulting speed-up in computation time permits a broad detailed examination of constraints by the mission analyst
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