6,419 research outputs found
Poetic License: Learning Morality from Fiction in light of Imaginative Resistance
Imaginative resistance (IR) is rejecting a claim that is true within a fictional world. Accounts that describe IR hold that readers exit a fiction at points of resistance. But if resistance entails exiting a fiction, then learning morality from fiction doesn’t occur. But moral learning from fiction does occur; some such cases are instances of accepting a norm one first denied. I amend current solutions to IR with poetic license. The more poetic license granted a work, the more flexible one is regarding perceived falsehoods. Instead of exiting the fiction, one has the chance to stay engaged and possibly learn norms she previously denied
How We Got a 75.4% Response Rate on an Internet Survey
Presentation on how to receive a high survey response rate using the Dillon Method, Survey Monkey and various contact steps
Inference with interference between units in an fMRI experiment of motor inhibition
An experimental unit is an opportunity to randomly apply or withhold a
treatment. There is interference between units if the application of the
treatment to one unit may also affect other units. In cognitive neuroscience, a
common form of experiment presents a sequence of stimuli or requests for
cognitive activity at random to each experimental subject and measures
biological aspects of brain activity that follow these requests. Each subject
is then many experimental units, and interference between units within an
experimental subject is likely, in part because the stimuli follow one another
quickly and in part because human subjects learn or become experienced or
primed or bored as the experiment proceeds. We use a recent fMRI experiment
concerned with the inhibition of motor activity to illustrate and further
develop recently proposed methodology for inference in the presence of
interference. A simulation evaluates the power of competing procedures.Comment: Published by Journal of the American Statistical Association at
http://www.tandfonline.com/doi/full/10.1080/01621459.2012.655954 . R package
cin (Causal Inference for Neuroscience) implementing the proposed method is
freely available on CRAN at https://CRAN.R-project.org/package=ci
Strange Quarks Nuggets in Space: Charges in Seven Settings
We have computed the charge that develops on an SQN in space as a result of
balance between the rates of ionization by ambient gammas and capture of
ambient electrons. We have also computed the times for achieving that
equilibrium and binding energy of the least bound SQN electrons. We have done
this for seven different settings. We sketch the calculations here and give
their results in the Figure and Table II; details are in the Physical Review
D.79.023513 (2009).Comment: Six pages, one figure. To appear in proceedings of the 2008 UCLA
coference on dark matter and dark energ
Strongly-coupled quantum critical point in an all-in-all-out antiferromagnet
Dimensionality and symmetry play deterministic roles in the laws of Nature.
They are important tools to characterize and understand quantum phase
transitions, especially in the limit of strong correlations between spin,
orbit, charge, and structural degrees of freedom. Using newly-developed,
high-pressure resonant x-ray magnetic and charge diffraction techniques, we
have discovered a quantum critical point in Cd2Os2O7 as the all-in-all-out
(AIAO) antiferromagnetic order is continuously suppressed to zero temperature
and, concomitantly, the cubic lattice structure continuously changes from space
group Fd-3m to F-43m. Surrounded by three phases of different time reversal and
spatial inversion symmetries, the quantum critical region anchors two phase
lines of opposite curvature, with striking departures from a mean-field form at
high pressure. As spin fluctuations, lattice breathing modes, and quasiparticle
excitations interact in the quantum critical region, we argue that they present
the necessary components for strongly-coupled quantum criticality in this
three-dimensional compound
Uselessness for an Oracle Model with Internal Randomness
We consider a generalization of the standard oracle model in which the oracle
acts on the target with a permutation selected according to internal random
coins. We describe several problems that are impossible to solve classically
but can be solved by a quantum algorithm using a single query; we show that
such infinity-vs-one separations between classical and quantum query
complexities can be constructed from much weaker separations.
We also give conditions to determine when oracle problems---either in the
standard model, or in any of the generalizations we consider---cannot be solved
with success probability better than random guessing would achieve. In the
oracle model with internal randomness where the goal is to gain any nonzero
advantage over guessing, we prove (roughly speaking) that quantum queries
are equivalent in power to classical queries, thus extending results of
Meyer and Pommersheim.Comment: 18 pages. v2. shortened, presentation improved, same result
The Arboricity Captures the Complexity of Sampling Edges
In this paper, we revisit the problem of sampling edges in an unknown graph from a distribution that is (pointwise) almost uniform over . We consider the case where there is some a priori upper bound on the arboriciy of . Given query access to a graph over vertices and of average degree and arboricity at most , we design an algorithm that performs queries in expectation and returns an edge in the graph such that every edge is sampled with probability . The algorithm performs two types of queries: degree queries and neighbor queries. We show that the upper bound is tight (up to poly-logarithmic factors and the dependence in ), as queries are necessary for the easier task of sampling edges from any distribution over that is close to uniform in total variational distance. We also prove that even if is a tree (i.e., so that ), queries are necessary to sample an edge from any distribution that is pointwise close to uniform, thus establishing that a factor is necessary for constant . Finally we show how our algorithm can be applied to obtain a new result on approximately counting subgraphs, based on the recent work of Assadi, Kapralov, and Khanna (ITCS, 2019)
How to predict the consequences of a tick value change? Evidence from the Tokyo Stock Exchange pilot program
The tick value is a crucial component of market design and is often considered the most suitable tool to mitigate the effects of high frequency trading. The goal of this paper is to demonstrate that the approach introduced in Dayri and Rosenbaum (2015) allows for an ex ante assessment of the consequences of a tick value change on the microstructure of an asset. To that purpose, we analyze the pilot program on tick value modifications started in 2014 by the Tokyo Stock Exchange in light of this methodology. We focus on forecasting the future cost of market and limit orders after a tick value change and show that our predictions are very accurate. Furthermore, for each asset involved in the pilot program, we are able to define (ex ante) an optimal tick value. This enables us to classify the stocks according to the relevance of their tick value, before and after its modification
The stability of a crystal with diamond structure for patchy particles with tetrahedral symmetry
The phase diagram of model anisotropic particles with four attractive patches
in a tetrahedral arrangement has been computed at two different values for the
range of the potential, with the aim of investigating the conditions under
which a diamond crystal can be formed. We find that the diamond phase is never
stable for our longer-ranged potential. At low temperatures and pressures, the
fluid freezes into a body-centred-cubic solid that can be viewed as two
interpenetrating diamond lattices with a weak interaction between the two
sublattices. Upon compression, an orientationally ordered face-centred-cubic
crystal becomes more stable than the body-centred-cubic crystal, and at higher
temperatures a plastic face-centered-cubic phase is stabilized by the increased
entropy due to orientational disorder. A similar phase diagram is found for the
shorter-ranged potential, but at low temperatures and pressures, we also find a
region over which the diamond phase is thermodynamically favored over the
body-centred-cubic phase. The higher vibrational entropy of the diamond
structure with respect to the body-centred-cubic solid explains why it is
stable even though the enthalpy of the latter phase is lower. Some preliminary
studies on the growth of the diamond structure starting from a crystal seed
were performed. Even though the diamond phase is never thermodynamically stable
for the longer-ranged model, direct coexistence simulations of the interface
between the fluid and the body-centred-cubic crystal and between the fluid and
the diamond crystal show that, at sufficiently low pressures, it is quite
probable that in both cases the solid grows into a diamond crystal, albeit
involving some defects. These results highlight the importance of kinetic
effects in the formation of diamond crystals in systems of patchy particles.Comment: 15 pages, 13 figure
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