95,168 research outputs found
Making automated computer program documentation a feature of total system design
It is pointed out that in large-scale computer software systems, program documents are too often fraught with errors, out of date, poorly written, and sometimes nonexistent in whole or in part. The means are described by which many of these typical system documentation problems were overcome in a large and dynamic software project. A systems approach was employed which encompassed such items as: (1) configuration management; (2) standards and conventions; (3) collection of program information into central data banks; (4) interaction among executive, compiler, central data banks, and configuration management; and (5) automatic documentation. A complete description of the overall system is given
Principal Series Representations of Direct Limit Groups
We combine the geometric realization of principal series representations of
the author, with the Bott--Borel--Weil Theorem for direct limits of compact
groups of Natarajan, Rodriguez-Carrington and the author, obtaining limits of
principal series representations for direct limits of real reductive Lie
groups. We introduce the notion of weakly parabolic direct limits and relate it
to the conditions that the limit representations are norm--preserving
representations on a Banach space or unitary representations on a Hilbert
space. We specialize the results to diagonal embedding direct limit groups.
Finally we discuss the possibilities of extending the results to limits of
tempered series other than the principal series.Comment: 28 page
On the Analytic Structure of Commutative Nilmanifolds
In the classification theorems of Vinberg and Yakimova for commutative
nilmanifolds, the relevant nilpotent groups have a very surprising analytic
property. The manifolds are of the form where, in all but
three cases, the nilpotent group has irreducible unitary representations
whose coefficients are square integrable modulo the center of . Here we
show that, in those three "exceptional" cases, the group is a semidirect
product or where the normal
subgroup contains the center of and has irreducible unitary
representations whose coefficients are square integrable modulo . This leads
directly to explicit harmonic analysis and Fourier inversion formulae for
commutative nilmanifolds
Rates of Nuclear Reactions in Solid-Like Stars
In stellar matter as cool and dense as the interior of a white dwarf, the Coulomb energies between neighboring nuclei are large compared to the kinetic energies of the nuclei. Each nucleus is constrained to vibrate about an equilibrium position, and the motion of the nuclei in the interior of a white dwarf is similar to the motion of the atoms in a solid or liquid. We propose a solid-state method for calculating the rate at which a nuclear reaction proceeds between two identical nuclei oscillating about adjacent lattice sites. An effective potential U(r) derived by analyzing small lattice vibrations is used to represent the influence of the Coulomb fields of the lattice on the motion of the two reacting nuclei. The wave function describing the relative motion of the two reacting particles is obtained by solving the Schrödinger equation containing the effective potential U(r). From this wave function, we derive an expression for the reaction rate. The rates of the p+p and C^(12)+C^(12) reactions calculated using this solid-state method are typically 1 to 10 orders of magnitude smaller than those calculated by the method previously suggested by Cameron
Heat pipe thermal switch
A thermal switch for controlling the dissipation of heat between a body is described. The thermal switch is comprised of a flexible bellows defining an expansible vapor chamber for a working fluid located between an evaporation and condensation chamber. Inside the bellows is located a coiled retaining spring and four axial metal mesh wicks, two of which have their central portions located inside of the spring while the other two have their central portions located between the spring and the side wall of the bellows. The wicks are terminated and are attached to the inner surfaces of the outer end walls of evaporation and condensation chambers respectively located adjacent to the heat source and heat sink. The inner surfaces of the end walls furthermore include grooves to provide flow channels of the working fluid to and from the wick ends. The evaporation and condensation chambers are connected by turnbuckles and tension springs to provide a set point adjustment for setting the gap between an interface plate on the condensation chamber and the heat sink
Cycle Spaces of Infinite Dimensional Flag Domains
Let be a complex simple direct limit group, specifically
, or .
Let be a (generalized) flag in . If is
or we suppose further that
is isotropic. Let denote the corresponding flag
manifold; thus where is a parabolic subgroup of . In
a recent paper with Ignatyev and Penkov, we studied real forms of and
properties of their orbits on . Here we concentrate on open
--orbits . When is of hermitian type we work
out the complete --orbit structure of flag manifolds dual to the bounded
symmetric domain for . Then we develop the structure of the corresponding
cycle spaces . Finally we study the real and quaternionic
analogs of these theories. All this extends an large body of results from the
finite dimensional cases on the structure of hermitian symmetric spaces and
related cycle spaces.Comment: This revision improves the exposition and corrects a number of typos.
Earlier revisions had clarified the ordering of subspaces in a flag relative
to a given ordered basis of the ambient as well as the
product structure of the base cycles for flag domains of and
. These revisions had no effect on the results for the
structure of the cycle space
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