81,067 research outputs found
The Unhappy Marriage of Theory and Practice: An Analysis of a Battered Women\u27s Shelter
Focuses on the role of battered women\u27s shelters in the U.S. as a response to the problem of violence against women in society. Examination of the battered women\u27s movement and the shelters the movement has spawned; Contradictions between feminist ideology and reality; Role of the shelter itself as a social world
Proposal to National Aeronautics and Space Administration for continuation of a grazing incidence imaging telescope for X-ray astronomy using sounding rockets
The construction of a high resolution imaging telescope experiment payload suitable for launch on an Astrobee F sounding rocket was proposed. Also integration, launch, and subsequent data analysis effort were included. The payload utilizes major component subassemblies from the HEAO-B satellite program which were nonflight development units for that program. These were the X ray mirror and high resolution imager brassboard detector. The properties of the mirror and detector were discussed. The availability of these items for a sounding rocket experiment were explored with the HEAO-B project office
Delayed adaptive antenna subset selection in measured wireless MIMO channels
Adaptive antenna subset selection can improve the expected theoretical capacity of a multiple-input, multiple-output (MIMO) wireless channel, whilst maintaining the tractable complexity of the lower order MIMO system. This paper seeks to explore the effects of delayed selection using measured indoor channel data at 5.2GHz, reflecting more accurately the situation facing a real-time system. Several selection schemes are considered and results show that delayed selection, while not as effective as instantaneous selection, can still improve the expected capacity by a significant margi
The effects of the waiting list on families of mentally ill patients
Thesis (M.S.)--Boston Universit
Acoustic vibrations of anisotropic nanoparticles
Acoustic vibrations of nanoparticles made of materials with anisotropic
elasticity and nanoparticles with non-spherical shapes are theoretically
investigated using a homogeneous continuum model. Cubic, hexagonal and
tetragonal symmetries of the elasticity are discussed, as are spheroidal,
cuboctahedral and truncated cuboctahedral shapes. Tools are described to
classify the different vibrations and for example help identify the modes
having a significant low-frequency Raman scattering cross-section. Continuous
evolutions of the modes starting from those of an isotropic sphere coupled with
the determination of the irreducible representation of the branches permit some
qualitative statements to be made about the nature of various modes. For
spherical nanoparticles, a more accurate picture is obtained through
projections onto the vibrations of an isotropic sphere.Comment: 11 pages, 9 tables, 6 figure
Vibrations of weakly-coupled nanoparticles
The vibrations of a coupled pair of isotropic silver spheres are investigated
and compared with the vibrations of the single isolated spheres. Situations of
both strong coupling and also weak coupling are investigated using continuum
elasticity and perturbation theory. The numerical calculation of the eigenmodes
of such dimers is augmented with a symmetry analysis. This checks the
convergence and applicability of the numerical method and shows how the
eigenmodes of the dimer are constructed from those of the isolated spheres. The
frequencies of the lowest frequency vibrations of such dimers are shown to be
very sensitive to the strength of the coupling between the spheres. Some of
these modes can be detected by inelastic light scattering and time-resolved
optical measurements which provides a convenient way to study the nature of the
mechanical coupling in dimers of micro and nanoparticles.Comment: expanded version, 8 pages, 5 figures, 2 table
Model-based estimation of off-highway road geometry using single-axis LADAR and inertial sensing
This paper applies some previously studied extended
Kalman filter techniques for planar road geometry estimation
to the domain of autonomous navigation of off-highway
vehicles. In this work, a clothoid model of the road geometry is
constructed and estimated recursively based on road features
extracted from single-axis LADAR range measurements. We
present a method for feature extraction of the road centerline
in the image plane, and describe its application to recursive
estimation of the road geometry. We analyze the performance of
our method against simulated motion of varied road geometries
and against closed-loop detection, tracking and following of
desert roads. Our method accomodates full 6 DOF motion of
the vehicle as it navigates, constructs consistent estimates of the
road geometry with respect to a fixed global reference frame,
and requires an estimate of the sensor pose for each range
measurement
Space photography and the exploration of Mars
A general exposition of the scientific potentialities and analytic framework of space photography is presented using the photography of Mars from flybys and orbiters as the principal example. Space photography is treated here as a communication process in which planetary scene information is communicated to the eye-brain receiver of earth-based interpreters. The salient parameters of this process are: (1) total information returned, (2) surface resolution, and (3) a priori knowledge regarding the planetary surface observed
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