210 research outputs found
Comparison of shutter glasses and mirror stereoscope for measuring dynamic and static vergence
Vergence eye movement recordings in response to disparity step stimuli require to present different stimuli to the two eyes. The traditional method is a mirror stereoscope. Shutter glasses are more convenient, but have disadvantages as limited repetition rate, residual cross task, and reduced luminance. Therefore, we compared both techniques measuring (1) dynamic disparity step responses for stimuli of 1 and 3 deg and (2) fixation disparity, the static vergence error. Shutter glasses and mirror stereoscope gave very similar dynamic responses with correlations of about 0.95 for the objectively measured vergence velocity and for the response amplitude reached 400 ms after the step stimulus (measured objectively with eye movement recordings and subjectively with dichoptic nonius lines). Both techniques also provided similar amounts of fixation disparity, tested with dichoptic nonius lines
The effect of calibration errors on the accuracy of the eye movement recordings
For calibrating eye movement recordings, a regression between spatially defined calibration points and corresponding measured raw data is performed. Based on this regression, a confidence interval (CI) of the actually measured eye position can be calculated in order to quantify the measurement error introduced by inaccurate calibration coefficients. For calculating this CI, a standard deviation (SD) - depending on the calibration quality and the design of the calibration procedure - is needed. Examples of binocular recordings with separate monocular calibrations illustrate that the SD is almost independent of the number and spatial separation between the calibration points – even though the later was expected from theoretical simulation. Our simulations and recordings demonstrate that the SD depends critically on residuals at certain calibration points, thus robust regressions are suggested
Safety and benefits of biosolids (1996)
"New/1/96/4M.""Water Quality.""Focus area : nutrients and bacterial wastes.""Published by University Extension, University of Missouri-System.
Cover crops in Missouri : putting them to work on your farm (2016)
New 8/15; Link updates 4/16/Web
Managing New Product Development: A Project Management Manual
The purpose of this study is to develop a new product development project management manual for a typical firm. It will also investigate many of the problems companies have had managing the development of new products, as well how these companies have addressed the problems. The manual is intended to define a project management system by describing the goals of project management; the project management organization for the firm; job descriptions as they pertain to project management; the product development cycle; the project management process; and the procedures that will be used to plan, monitor, and control a project. It is not intended to be the ideal system for all firms, but one way to implement project management. For this reason, it will also outline a procedure to be used to customize the manual for a particular firm\u27s needs
Using Simulations of Black Holes to Study General Relativity and the Properties of Inner Accretion Flow
While Albert Einstein's theory of General Relativity (GR) has been tested
extensively in our solar system, it is just beginning to be tested in the
strong gravitational fields that surround black holes. As a way to study the
behavior of gravity in these extreme environments I have used and added to a
ray-tracing code that simulates the X-ray emission from the accretion disks
surrounding black holes. In particular, the observational channels which can be
simulated include the thermal and reflected spectra, polarization, and
reverberation signatures. These calculations can be performed assuming GR as
well as four alternative spacetimes. These results can be used to see if it is
possible to determine if observations can test the No-Hair theorem of GR which
states that stationary, astrophysical black holes are only described by their
mass and spin. Although it proves difficult to distinguish between theories of
gravity it is possible to exclude a large portion of the possible deviations
from GR using observations of rapidly spinning stellar mass black holes such as
Cygnus X-1. The ray-tracing simulations can furthermore be used to study the
inner regions of black hole accretion flows. I examined the dependence of X-ray
reverberation observations on the ionization of the disk photosphere. My
results show that X-ray reverberation and X-ray polarization provides a
powerful tool to constrain the geometry of accretion disks which are too small
to be imaged directly. The second part of my thesis describes the work on the
balloon-borne X-Calibur hard X-ray polarimetry mission and on the space-borne
PolSTAR polarimeter concept.Comment: PhD Thesi
Quasar accretion disk sizes from continuum reverberation mapping in the DES standard-star fields
Measurements of the physical properties of accretion disks in active galactic
nuclei are important for better understanding the growth and evolution of
supermassive black holes. We present the accretion disk sizes of 22 quasars
from continuum reverberation mapping with data from the Dark Energy Survey
(DES) standard star fields and the supernova C fields. We construct continuum
lightcurves with the \textit{griz} photometry that span five seasons of DES
observations. These data sample the time variability of the quasars with a
cadence as short as one day, which corresponds to a rest frame cadence that is
a factor of a few higher than most previous work. We derive time lags between
bands with both JAVELIN and the interpolated cross-correlation function method,
and fit for accretion disk sizes using the JAVELIN Thin Disk model. These new
measurements include disks around black holes with masses as small as
, which have equivalent sizes at 2500\AA \, as small as
light days in the rest frame. We find that most objects have
accretion disk sizes consistent with the prediction of the standard thin disk
model when we take disk variability into account. We have also simulated the
expected yield of accretion disk measurements under various observational
scenarios for the Large Synoptic Survey Telescope Deep Drilling Fields. We find
that the number of disk measurements would increase significantly if the
default cadence is changed from three days to two days or one day.Comment: 33 pages, 24 figure
Albumin-Nanopartikel als Drug Delivery System zur Oberflächenmodifikation poröser Polyethylenimplantate
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