722 research outputs found
Using Social Network Analysis on classroom video data
We propose a novel application of Social Network Analysis (SNA) using
classroom video data as a means of quantitatively and visually exploring the
collaborations between students. The context for our study was a summer program
that works with first generation students and deaf/hard-of-hearing students to
engage in authentic science practice and develop a supportive community. We
applied SNA to data from one activity during the two-week program to test our
approach and as a means to begin to assess whether the goals of the program are
being met. We used SNA to identify groups that were interacting in unexpected
ways and then to highlight how individuals were contributing to the overall
group behavior. We plan to expand our new use of SNA to video data on a larger
scale
IDENTIFICATION OF THE GEOLOGIC ORIGINS OF ARCHAEOLOGICAL ARTIFACTS: AN AUTOMATED METHOD OF Na and Mn NEUTRON ACTIVATION ANALYSIS
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66345/1/j.1475-4754.1967.tb00618.x.pd
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Analytical comparison of various Egyptian soils, clays, shales, and some ancient pottery by neutron activation
as a basis for classiftcation of clays and for tracing the origin of the parent materials used in pottery manufacturing, Nine pottery specimens were analyzed as a very preliminary test of the potential of correlation between clay and pottery compositions. (LK
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Compositional attribution of non-provenienced Maya polychrome vessels
Procedures and a few of the results of the Maya ceramic project are discussed from the perspective of non-provenienced vessel attribution ranging from site specific through a more inferential level to the rather hypothetical. The examples presented serve to illustrate the manner in which compositional and stylistic covariation are viewed in an investigation of Maya Ceramic art. The large data base from neutron activation analysis including archaeologically recovered pottery as well as the stylistically and iconographically elaborate vessels requires continued refinement in our methods of statistical analysis along with gaining a greater understanding of the sources of ceramic compositional variation in the Maya area. The mutually beneficial collaboration between science, art, and archaeology are emphasized
Performance and on-sky optical characterization of the SPTpol instrument
In January 2012, the 10m South Pole Telescope (SPT) was equipped with a
polarization-sensitive camera, SPTpol, in order to measure the polarization
anisotropy of the cosmic microwave background (CMB). Measurements of the
polarization of the CMB at small angular scales (~several arcminutes) can
detect the gravitational lensing of the CMB by large scale structure and
constrain the sum of the neutrino masses. At large angular scales (~few
degrees) CMB measurements can constrain the energy scale of Inflation. SPTpol
is a two-color mm-wave camera that consists of 180 polarimeters at 90 GHz and
588 polarimeters at 150 GHz, with each polarimeter consisting of a dual
transition edge sensor (TES) bolometers. The full complement of 150 GHz
detectors consists of 7 arrays of 84 ortho-mode transducers (OMTs) that are
stripline coupled to two TES detectors per OMT, developed by the TRUCE
collaboration and fabricated at NIST. Each 90 GHz pixel consists of two
antenna-coupled absorbers coupled to two TES detectors, developed with Argonne
National Labs. The 1536 total detectors are read out with digital
frequency-domain multiplexing (DfMUX). The SPTpol deployment represents the
first on-sky tests of both of these detector technologies, and is one of the
first deployed instruments using DfMUX readout technology. We present the
details of the design, commissioning, deployment, on-sky optical
characterization and detector performance of the complete SPTpol focal plane.Comment: 15 pages, 6 figures. Conference: SPIE Astronomical Telescopes and
Instrumentation 201
Design and characterization of 90 GHz feedhorn-coupled TES polarimeter pixels in the SPTpol camera
The SPTpol camera is a two-color, polarization-sensitive bolometer receiver,
and was installed on the 10 meter South Pole Telescope in January 2012. SPTpol
is designed to study the faint polarization signals in the Cosmic Microwave
Background, with two primary scientific goals. One is to constrain the
tensor-to-scalar ratio of perturbations in the primordial plasma, and thus
constrain the space of permissible inflationary models. The other is to measure
the weak lensing effect of large-scale structure on CMB polarization, which can
be used to constrain the sum of neutrino masses as well as other growth-related
parameters. The SPTpol focal plane consists of seven 84-element monolithic
arrays of 150 GHz pixels (588 total) and 180 individual 90 GHz single-pixel
modules. In this paper we present the design and characterization of the 90 GHz
modules
Feedhorn-coupled TES polarimeter camera modules at 150 GHz for CMB polarization measurements with SPTpol
The SPTpol camera is a dichroic polarimetric receiver at 90 and 150 GHz.
Deployed in January 2012 on the South Pole Telescope (SPT), SPTpol is looking
for faint polarization signals in the Cosmic Microwave Background (CMB). The
camera consists of 180 individual Transition Edge Sensor (TES) polarimeters at
90 GHz and seven 84-polarimeter camera modules (a total of 588 polarimeters) at
150 GHz. We present the design, dark characterization, and in-lab optical
properties of the 150 GHz camera modules. The modules consist of
photolithographed arrays of TES polarimeters coupled to silicon platelet arrays
of corrugated feedhorns, both of which are fabricated at NIST-Boulder. In
addition to mounting hardware and RF shielding, each module also contains a set
of passive readout electronics for digital frequency-domain multiplexing. A
single module, therefore, is fully functional as a miniature focal plane and
can be tested independently. Across the modules tested before deployment, the
detectors average a critical temperature of 478 mK, normal resistance R_N of
1.2 Ohm, unloaded saturation power of 22.5 pW, (detector-only) optical
efficiency of ~ 90%, and have electrothermal time constants < 1 ms in
transition.Comment: 15 pages, 11 figure
South Pole Telescope Software Systems: Control, Monitoring, and Data Acquisition
We present the software system used to control and operate the South Pole
Telescope. The South Pole Telescope is a 10-meter millimeter-wavelength
telescope designed to measure anisotropies in the cosmic microwave background
(CMB) at arcminute angular resolution. In the austral summer of 2011/12, the
SPT was equipped with a new polarization-sensitive camera, which consists of
1536 transition-edge sensor bolometers. The bolometers are read out using 36
independent digital frequency multiplexing (\dfmux) readout boards, each with
its own embedded processors. These autonomous boards control and read out data
from the focal plane with on-board software and firmware. An overall control
software system running on a separate control computer controls the \dfmux
boards, the cryostat and all other aspects of telescope operation. This control
software collects and monitors data in real-time, and stores the data to disk
for transfer to the United States for analysis
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