5,948 research outputs found
A Teacher in the Living Room? Educational Media for Babies, Toddlers, and Preschoolers
Examines available research, and arguments by proponents and critics, of electronic educational media use by young children. Examines educational claims in marketing and provides recommendations for developing research and product standards
Clinical ophthalmic ultrasound improvements
The use of digital synthetic aperture techniques to obtain high resolution ultrasound images of eye and orbit was proposed. The parameters of the switched array configuration to reduce data collection time to a few milliseconds to avoid eye motion problems in the eye itself were established. An assessment of the effects of eye motion on the performance of the system was obtained. The principles of synthetic techniques are discussed. Likely applications are considered
A High-Fidelity Realization of the Euclid Code Comparison -body Simulation with Abacus
We present a high-fidelity realization of the cosmological -body
simulation from the Schneider et al. (2016) code comparison project. The
simulation was performed with our Abacus -body code, which offers high force
accuracy, high performance, and minimal particle integration errors. The
simulation consists of particles in a box,
for a particle mass of with $10\
h^{-1}\mathrm{kpc}z=0<0.3\%k<10\
\mathrm{Mpc}^{-1}h0.01\%$. Simulation snapshots are available at
http://nbody.rc.fas.harvard.edu/public/S2016 .Comment: 13 pages, 8 figures. Minor changes to match MNRAS accepted versio
Partial breakdown of quantum thermalization in a Hubbard-like model
We study the possible breakdown of quantum thermalization in a model of
itinerant electrons on a one-dimensional chain without disorder, with both spin
and charge degrees of freedom. The eigenstates of this model exhibit peculiar
properties in the entanglement entropy, the apparent scaling of which is
modified from a "volume law" to an "area law" after performing a partial,
site-wise measurement on the system. These properties and others suggest that
this model realizes a new, non-thermal phase of matter, known as a quantum
disentangled liquid (QDL). The putative existence of this phase has striking
implications for the foundations of quantum statistical mechanics.Comment: As accepted to PR
Issue Framing as a Tool to Understand Opportunities for Policy Change
The global climate change agreement completed on December 12, 2015 in Paris
set a collective target to cap greenhouse gas emissions in order to limit the
temperature increase to 2 degrees Celsius with a goal to get as close as
possible to 1.5 degrees above pre-industrial levels. These goals were to be
accomplished through a “bottom up” mechanism for national policy approaches in
which states made their own choices about how they would meet climate targets.
This paper examines why and how an agreement was possible in 2015 when it had
not been before. What was different in Paris, or leading up to Paris, so that
the parties involved successfully came to an agreement when it was not
possible in Copenhagen? This paper presents a problem definition and issue
framing perspective to examine the shift in the discussion in Paris from the
burdens of climate action to opportunities climate action offered for economic
and development models. It provides a road map to understand the role of key
stakeholders, including governments, the business community, civil society,
and subnational actors in the making of the climate agreement
A conceptual design of a large aperture microwave radiometer geostationary platform
A conceptual design of a Large Aperture Microwave Radiometer (LAMR) Platform has been developed and technology areas essential to the design and on-orbit viability of the platform have been defined. Those technologies that must be developed to the requirement stated here for the LAMR mission to be viable include: advanced radiation resistant solar cells, integrated complex structures, large segmented reflector panels, sub 3 kg/m(exp 2) areal density large antennas, and electric propulsion systems. Technology areas that require further development to enhance the capabilities of the LAMR platform (but are not essential for viability) include: electrical power storage, on-orbit assembly, and on-orbit systems checkout and correction
On the physical association of the peculiar emission: Line stars HD 122669 and HD 122691
Spectroscopic and photometric observations indicate a physical association between the peculiar early-type emission-line stars HD 122669 and HD 122691. The latter has undergone a drastic change in the strength of its emission lines during the past twenty years. There is some indication that both stars vary with shorter time scales
Overcoming Obstacles in Global Climate Action from Copenhagen to Paris: Issue Framing as a Tool to Understand Opportunities for Policy Change
The global climate change agreement completed on December 12, 2015 in Paris set a collective target to cap greenhouse gas emissions in order to limit the temperature increase to 2 degrees Celsius with a goal to get as close as possible to 1.5 degrees above pre-industrial levels. These goals were to be accomplished through a “bottom up” mechanism for national policy approaches in which states made their own choices about how they would meet climate targets. This paper examines why and how an agreement was possible in 2015 when it had not been before. What was different in Paris, or leading up to Paris, so that the parties involved successfully came to an agreement when it was not possible in Copenhagen? This paper presents a problem definition and issue framing perspective to examine the shift in the discussion in Paris from the burdens of climate action to opportunities climate action offered for economic and development models. It provides a road map to understand the role of key stakeholders, including governments, the business community, civil society, and subnational actors in the making of the climate agreement
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