title: Squarability of rectangle arrangements

abstract:
  We study when an arrangement of axis-aligned rectangles can be transformed
into an arrangement of axis-aligned squares in $\mathbb{R}^2$ while preserving
its structure. We found a counterexample to the conjecture of J. Klawitter, M.
N\"ollenburg and T. Ueckerdt whether all arrangements without crossing and
side-piercing can be squared. Our counterexample also works in a more general
case when we only need to preserve the intersection graph and we forbid
side-piercing between squares. We also show counterexamples for transforming
box arrangements into combinatorially equivalent hypercube arrangements.
Finally, we introduce a linear program deciding whether an arrangement of
rectangles can be squared in a more restrictive version where the order of all
sides is preserved.


title: Path-integral formula for local thermal equilibrium

abstract:
  We develop a complete path-integral formulation of relativistic quantum
fields in local thermal equilibrium, which brings about the emergence of
thermally induced curved spacetime. The resulting action is shown to have full
diffeomorphism invariance and gauge invariance in thermal spacetime with
imaginary-time independent backgrounds. This leads to the notable symmetry
properties of emergent thermal spacetime: Kaluza-Klein gauge symmetry, spatial
diffeomorphism symmetry, and gauge symmetry. A thermodynamic potential in local
thermal equilibrium, or the so-called Masseiu-Planck functional, is identified
as a generating functional for conserved currents such as the energy-momentum
tensor and the electric current.

categories: hep-th cond-mat.quant-gas cond-mat.stat-mech hep-ph nucl-th


title:
Discovery of a soft X-ray 8 mHz QPO from the accreting millisecond
  pulsar IGR J00291+5934

abstract:
  In this paper, we report on the analysis of the peculiar X-ray variability
displayed by the accreting millisecond X-ray pulsar IGR J00291+5934 in a 80
ks-long joint NuSTAR and XMM-Newton observation performed during the source
outburst in 2015. The light curve of the source was characterized by a
flaring-like behavior, with typical rise and decay time scales of ~120 s. The
flares are accompanied by a remarkable spectral variability, with the X-ray
emission being generally softer at the peak of the flares. A strong quasi
periodic oscillation (QPO) is detected at ~8 mHz in the power spectrum of the
source and clearly associated with the flaring-like behavior. This feature has
the strongest power at soft X-rays (<3 keV). We carried out a dedicated
hardness-ratio resolved spectral analysis and a QPO phase-resolved spectral
analysis, together with an in-depth study of the source timing properties, to
investigate the origin of this behavior. We suggest that the unusual
variability of IGR J00291+5934 observed by XMM-Newton and NuSTAR could be
produced by an heartbeat-like mechanism, similar to that operating in
black-hole X-ray binaries. The possibility that this variability, and the
associated QPO, are triggered by phases of quasi-stable nuclear burning, as
suggested in the literature for a number of other neutron star binaries
displaying a similar behavior, cannot be solidly tested in the case of IGR
J00291+5934 due to the paucity of type-I X-ray bursts observed from this
source.


title:
Wireless Power Transfer by Means of Electromagnetic Radiation Within an
  Enclosed Space

abstract:
  In this paper, wireless power transfer by means of electromagnetic radiation
is investigated. Formulas are derived for the efficiency of the power transfer
in free space, in the presence of reflecting surfaces, and within enclosed
spaces. It is found that the presence of reflecting surfaces has the capacity
to substantially enhance the efficiency of power transfer at long range. An
upper limit is also found for the transferred power when constraints are
imposed on certain forms of undesired absorption. For the sake of simplicity,
only the efficiency of the radiative power transfer is considered. Losses due
to resistance in the antenna structures or inefficiencies in RF to DC
conversion are neglected.


title: Matching the Unmatchable. Complexity Theory and Quantum Theory

abstract:
  This is a philosophical paper. It claims that there is a gap to be filled in
the relationship between complexity theory (CT) and quantum theory (QT). This
gap concerns two very distinct understandings of time. The paper provides the
ground for filling up such gap. Indeed, most works on complexity at large focus
on the macroscopic world, leaving behind the importance of the microscopic
world. This paper specifies what both worlds consist of, and argues that a
solid account of the world, i.e. complexity, must necessarily take into account
both dimensions of reality.


title:
A Deep Learning Approach for Joint Video Frame and Reward Prediction in
  Atari Games

abstract:
  Reinforcement learning is concerned with identifying reward-maximizing
behaviour policies in environments that are initially unknown. State-of-the-art
reinforcement learning approaches, such as deep Q-networks, are model-free and
learn to act effectively across a wide range of environments such as Atari
games, but require huge amounts of data. Model-based techniques are more
data-efficient, but need to acquire explicit knowledge about the environment.
  In this paper, we take a step towards using model-based techniques in
environments with a high-dimensional visual state space by demonstrating that
it is possible to learn system dynamics and the reward structure jointly. Our
contribution is to extend a recently developed deep neural network for video
frame prediction in Atari games to enable reward prediction as well. To this
end, we phrase a joint optimization problem for minimizing both video frame and
reward reconstruction loss, and adapt network parameters accordingly. Empirical
evaluations on five Atari games demonstrate accurate cumulative reward
prediction of up to 200 frames. We consider these results as opening up
important directions for model-based reinforcement learning in complex,
initially unknown environments.


title: Thermal stability and topological protection of skyrmions in nanotracks

abstract:
  Magnetic skyrmions are hailed as a potential technology for data storage and
other data processing devices. However, their stability against thermal
fluctuations is an open question that must be answered before skyrmion-based
devices can be designed. In this work, we study paths in the energy landscape
via which the transition between the skyrmion and the uniform state can occur
in interfacial Dzyaloshinskii-Moriya finite-sized systems. We find three
mechanisms the system can take in the process of skyrmion nucleation or
destruction and identify that the transition facilitated by the boundary has a
significantly lower energy barrier than the other energy paths. This clearly
demonstrates the lack of the skyrmion topological protection in finite-sized
magnetic systems. Overall, the energy barriers of the system under
investigation are too small for storage applications at room temperature, but
research into device materials, geometry and design may be able to address
this.


title: K2 Ultracool Dwarfs Survey I: Photometry of an L Dwarf Superflare

abstract:
  We report on K2 Campaign 8 measurements of a huge white light flare on the L1
dwarf SDSSp J005406.55-003101.8 (EPIC 220186653). The source is a typical L1
dwarf at a distance of $\sim50$ pc, probably an old hydrogen-burning star
rather than a young brown dwarf. In the long (30-minute) cadence photometry,
the flare peak is 21 times the flux of the stellar photosphere in the broad
optical Kepler filter, which we estimate corresponds to $\Delta V \approx
-7.1$. The total equivalent duration of the flare is 15.4 hr. We estimate the
total bolometric energy of the flare was $4 \times 10^{33}$ erg, more powerful
than the previously reported Kepler white light flares for the L1 dwarf WISEP
J190648.47+401106.8, but weaker than the $\Delta V = -11$ L0 dwarf superflare
ASASSN-16ae. The initial (impulsive) cooling phase is too rapid to resolve with
our 30-minute cadence data, but after one hour the gradual cooling phase has an
exponential time constant of 1.8 hours. We use template fitting to estimate
that the full-time-width-at-half-amplitude of the light curve is $<10$ minutes
and that the true flare maximum reached $\sim70$ times the stellar photosphere,
or $\Delta V \approx -8$. This flare is comparable to the most powerful Kepler
flares observed on the active M4 dwarf GJ 1243.


title:
Subdiffusion--absorption process in a system consisting of two different
  media

abstract:
  Subdiffusion with reaction $A+B\rightarrow B$ is considered in a system which
consists of two homogeneous media joined together; the $A$ particles are mobile
whereas $B$ are static. Subdiffusion and reaction parameters, which are assumed
to be independent of time and space variable, can be different in both media.
Particles $A$ move freely across the border between the media. In each part of
the system the process is described by the subdiffusion--reaction equations
with fractional time derivative. By means of the method presented in this paper
we derive both the fundamental solutions (the Green's functions) $P(x,t)$ to
the subdiffusion--reaction equations and the boundary conditions at the border
between the media. One of the conditions demands the continuity of a flux and
the other one contains the Riemann--Liouville fractional time derivatives
$\partial^{\alpha_1}P(0^+,t)/\partial
t^{\alpha_1}=(D_1/D_2)\partial^{\alpha_2}P(0^-,t)/\partial t^{\alpha_2}$, where
the subdiffusion parameters $\alpha_1$, $D_1$ and $\alpha_2$, $D_2$ are defined
in the regions $x<0$ and $x>0$, respectively.


title:
Propagation of Chaos and Effective Equations in Kinetic Theory: a Brief
  Survey

abstract:
  We review some historical highlights leading to the modern perspective on the
concept of chaos from the point of view of the kinetic theory. We focus in
particular on the role played by the propagation of chaos in the mathematical
derivation of effective equations.

categories: math-ph cond-mat.stat-mech math.AP math.MP


title: pocl: A Performance-Portable OpenCL Implementation

abstract:
  OpenCL is a standard for parallel programming of heterogeneous systems. The
benefits of a common programming standard are clear; multiple vendors can
provide support for application descriptions written according to the standard,
thus reducing the program porting effort. While the standard brings the obvious
benefits of platform portability, the performance portability aspects are
largely left to the programmer. The situation is made worse due to multiple
proprietary vendor implementations with different characteristics, and, thus,
required optimization strategies.
  In this paper, we propose an OpenCL implementation that is both portable and
performance portable. At its core is a kernel compiler that can be used to
exploit the data parallelism of OpenCL programs on multiple platforms with
different parallel hardware styles. The kernel compiler is modularized to
perform target-independent parallel region formation separately from the
target-specific parallel mapping of the regions to enable support for various
styles of fine-grained parallel resources such as subword SIMD extensions, SIMD
datapaths and static multi-issue. Unlike previous similar techniques that work
on the source level, the parallel region formation retains the information of
the data parallelism using the LLVM IR and its metadata infrastructure. This
data can be exploited by the later generic compiler passes for efficient
parallelization.
  The proposed open source implementation of OpenCL is also platform portable,
enabling OpenCL on a wide range of architectures, both already commercialized
and on those that are still under research. The paper describes how the
portability of the implementation is achieved. Our results show that most of
the benchmarked applications when compiled using pocl were faster or close to
as fast as the best proprietary OpenCL implementation for the platform at hand.


title: Higgs-otic Inflation and Moduli Stabilization

abstract:
  We study closed-string moduli stabilization in Higgs-otic inflation in Type
IIB orientifold backgrounds with fluxes. In this setup large-field inflation is
driven by the vacuum energy of mobile D7-branes. Imaginary selfdual (ISD)
three-form fluxes in the background source a $\mu$-term and the necessary
monodromy for large field excursions while imaginary anti-selfdual (IASD)
three-form fluxes are sourced by non-perturbative contributions to the
superpotential necessary for moduli stabilization. We analyze K\"ahler moduli
stabilization and backreaction on the inflaton potential in detail. Confirming
results in the recent literature, we find that integrating out heavy K\"ahler
moduli leads to a controlled flattening of the inflaton potential. We quantify
the flux tuning necessary for stability even during large-field inflation.
Moreover, we study the backreaction of supersymmetrically stabilized complex
structure moduli and the axio-dilaton in the K\"ahler metric of the inflaton.
Contrary to previous findings, this backreaction can be pushed far out in field
space if a similar flux tuning as in the K\"ahler sector is possible. This
allows for a trans-Planckian field range large enough to support inflation.


title:
Heterodyne-Detected Ultrafast X-Ray Diffraction and Scattering from
  Nonstationary States

abstract:
  Free-electron laser hard X-ray light sources can provide high fluence,
femtosecond pulses, enabling the time-resolved probing of structural dynamics
and elementary relaxation processes in molecules. Traditional X-ray elastic
scattering from crystals in the ground state consists of sharp Bragg
diffraction peaks that arise from pairs of molecules and reveal the ground
state charge density. Scattering of ultrashort X-ray pulses from gases,
liquids, and even single molecules is more complex and involves both single-
and two- molecule contributions, diffuse (non-Bragg) features, elastic and
inelastic components, contributions of electronic coherences in nonstationary
states, and interferences between scattering off different states (heterodyne
detection). We present a unified description that covers all these processes
and discuss their relative magnitudes for gas-phase NaI. Conditions for the
observation of holographic (heterodyne) interference, which has been recently
discussed [1], are clarified.


title:
Exact Solutions to Some Conformable Time Fractional Equations in
  Benjamin-Bona-Mahony Family

abstract:
  The conformable time fractional forms of some partial differential equations
are solved in the study. The existence of chain rule and the derivative of
composite function enable the equations to be reduced to some ordinary
differential equations by using some particular wave transformations. The
modified Kudryashov method implemented to derive the exact solutions for the
Benjamin-Bona Mahony (BBM), the symmetric BBM and the equal width (EW)
equations in the conformable fractional time derivative forms. The obtained
explicit solutions are illustrated for some time fractional orders in the
interval $(0,1]$.


title: Connectivity in Hypergraphs

abstract:
  In this paper we consider two natural notions of connectivity for
hypergraphs: weak and strong. We prove that the strong vertex connectivity of a
connected hypergraph is bounded by its weak edge connectivity, thereby
extending a theorem of Whitney from graphs to hypergraphs. We find that while
determining a minimum weak vertex cut can be done in polynomial time and is
equivalent to finding a minimum vertex cut in the 2-section of the hypergraph
in question, determining a minimum strong vertex cut is NP-hard for general
hypergraphs. Moreover, the problem of finding minimum strong vertex cuts
remains NP-hard when restricted to hypergraphs with maximum edge size at most
3. We also discuss the relationship between strong vertex connectivity and the
minimum transversal problem for hypergraphs, showing that there are classes of
hypergraphs for which one of the problems is NP-hard while the other can be
solved in polynomial time.


title: Statistics of genus numbers of cubic fields

abstract:
  We prove that approximately $96.23\%$ of cubic fields, ordered by
discriminant, have genus number one, and we compute the exact proportion of
cubic fields with a given genus number. We also compute the average genus
number. Finally, we show that a positive proportion of totally real cubic
fields with genus number one fail to be norm-Euclidean.


title:
Twisting Anderson pseudospins with light: Quench dynamics in THz-pumped
  BCS superconductors

abstract:
  We study the preparation (pump) and the detection (probe) of
far-from-equilibrium BCS superconductor dynamics in THz pump-probe experiments.
In a recent experiment [R. Matsunaga, Y. I. Hamada, K. Makise, Y. Uzawa, H.
Terai, Z. Wang, and R. Shimano, Phys. Rev. Lett. {\bf 111}, 057002 (2013)], an
intense monocycle THz pulse with center frequency $\omega \simeq \Delta$ was
injected into a superconductor with BCS gap $\Delta$; the subsequent post-pump
evolution was detected via the optical conductivity. It was argued that
nonlinear coupling of the pump to the Anderson pseudospins of the
superconductor induces coherent dynamics of the Higgs (amplitude) mode
$\Delta(t)$. We validate this picture in a two-dimensional BCS model with a
combination of exact numerics and the Lax reduction method, and we compute the
nonequilibrium phase diagram as a function of the pump intensity. The main
effect of the pump is to scramble the orientations of Anderson pseudospins
along the Fermi surface by twisting them in the $xy$-plane. We show that more
intense pump pulses can induce a far-from-equilibrium phase of gapless
superconductivity ("phase I"), originally predicted in the context of
interaction quenches in ultracold atoms. We show that the THz pump method can
reach phase I at much lower energy densities than an interaction quench, and we
demonstrate that Lax reduction (tied to the integrability of the BCS
Hamiltonian) provides a general quantitative tool for computing coherent BCS
dynamics. We also calculate the Mattis-Bardeen optical conductivity for the
nonequilibrium states discussed here.


title:
Diatomic molecule as a testbed for combining DMFT with electronic
  structure methods such as $GW$ and DFT

abstract:
  We implemented combination of DMFT and $GW$ in its fully self-consistent way,
one shot $GW$ approximation, and quasiparticle self-consistent scheme, and
studied how well these combined methods perform on H$_2$ molecule as compared
to more established methods such as LDA+DMFT. We found that most flavors of
$GW$+DMFT break down in strongly correlated regime due to causality violation.
Among $GW$+DMFT methods, only the self-consistent quasiparticle $GW$+DMFT with
static double-counting, and a new method with causal double-counting, correctly
recover the atomic limit at large H-atom separation. While some flavors of
$GW$+DMFT improve the single-electron spectra as compared to LDA+DMFT, the
total energy is best predicted by LDA+DMFT, for which the exact double-counting
is known, and is static.


title: Rydberg optical Feshbach resonances in cold gases

abstract:
  We propose a novel scheme to efficiently tune the scattering length of two
colliding ground-state atoms by off-resonantly coupling the scattering-state to
an excited Rydberg-molecular state using laser light. For the s-wave scattering
of two colliding ${^{87}}\mathrm{Rb}$ atoms, we demonstrate that the effective
optical length and pole strength of this Rydberg optical Feshbach resonance can
be tuned over several orders of magnitude, while incoherent processes and
losses are minimised. Given the ubiquity of Rydberg molecular states, this
technique should be generally applicable to homo-nuclear atomic pairs as well
as to atomic mixtures with s-wave (or even p-wave) scattering.


title:
Spectroscopy of f-f transitions, crystal-field calculations, and
  magnetic and quadrupole helix chirality in DyFe$_3$(BO$_3$)$_4$

abstract:
  Recently, quadrupole helix chirality and its domain structure was observed in
resonant x-ray diffraction experiments on DyFe$_3$(BO$_3$)$_4$ using circularly
polarized x rays [T. Usui et al., Nature Materials 13, 611 (2014)]. We show
that this effect can be explained quantitatively by calculating the quadrupole
moments of the Dy$^{3+}$ ions induced by the low-symmetry ($C_2$) crystal-field
(CF) component. In this work, the CF parameters for the Dy$^{3+}$ ions in the
$P3_121$ ($P3_221$) phase of DyFe$_3$(BO$_3$)$_4$ are obtained from CF
calculations based on the analysis of high-resolution temperature-dependent
optical spectroscopy data. We also consider the helix chirality of the
single-site magnetic susceptibility tensors of the Dy$^{3+}$ ions in the
paramagnetic $P3_121$ ($P3_221$) phase and suggest a neutron diffraction
experiment to reveal it.


title:
Using Empirical Covariance Matrix in Enhancing Prediction Accuracy of
  Linear Models with Missing Information

abstract:
  Inference and Estimation in Missing Information (MI) scenarios are important
topics in Statistical Learning Theory and Machine Learning (ML). In ML
literature, attempts have been made to enhance prediction through precise
feature selection methods. In sparse linear models, LASSO is well-known in
extracting the desired support of the signal and resisting against noisy
systems. When sparse models are also suffering from MI, the sparse recovery and
inference of the missing models are taken into account simultaneously. In this
paper, we will introduce an approach which enjoys sparse regression and
covariance matrix estimation to improve matrix completion accuracy, and as a
result enhancing feature selection preciseness which leads to reduction in
prediction Mean Squared Error (MSE). We will compare the effect of employing
covariance matrix in enhancing estimation accuracy to the case it is not used
in feature selection. Simulations show the improvement in the performance as
compared to the case where the covariance matrix estimation is not used.


title: An amendment of the BCS theory of superconductivity

abstract:
  Although the BCS theory of superconductivity is a well established theory, we
have shown that the phenomenology predicted by this model is much richer than
previously believed. By releasing the constraint that the attraction band is
symmetric with respect to the chemical potential of the system, we observed
that the energy gap may have more than one solution, the quasiparticle
imbalance may appear in equilibrium, and the transition between the
superconducting and the normal metal phases may be of the first order. The
temperature of the superconductor-normal metal phase transition changes with
the asymmetry of the attraction band and if we plot the phase transition
temperature vs the chemical potential, we obtain a bell shaped curve, similarly
to the superconducting dome, generally formed in high-Tc superconductors, but
also in superconductors with narrow conduction bands.
  While the pairing interaction is a microscopic characteristic of the system,
determined by the effective interactions between constituent quasiparticles,
the chemical potential is a macroscopic quantity, which can be changed by
external conditions, like doping and pressure. Furthermore, if the conduction
band of the system is narrow, then the attraction band is constrained to the
conduction band and the chemical potential is not necessary in the center, as
it happens in some of the bands in In-doped Pb$_z$Sn$_{1-z}$ and in MgB$_{2}$.
For these reasons, the constraint that the attraction band is symmetric with
respect to the chemical potential may be released.


title:
Observations of Sagittarius A* during the pericenter passage of the G2
  object with MAGIC

abstract:
  Context. We present the results of a multi-year monitoring campaign of the
Galactic Center (GC) with the MAGIC telescopes. These observations were
primarily motivated by reports that a putative gas cloud (G2) would be passing
in close proximity to the super-massive black hole (SMBH), associated with
Sagittarius A*, located at the center of our galaxy. This event was expected to
give astronomers a unique chance to study the effect of in-falling matter on
the broad-band emission of a SMBH.
  Aims. We search for potential flaring emission of very-high-energy (VHE;
$\geq$100 GeV) gamma rays from the direction of the SMBH at the GC due to the
passage of the G2 object. Using these data we also study the morphology of this
complex region.
  Methods. We observed the GC region with the MAGIC Imaging Atmospheric
Cherenkov Telescopes during the period 2012-2015, collecting 67 hours of
good-quality data. In addition to a search for variability in the flux and
spectral shape of the GC gamma-ray source, we use a point-source subtraction
technique to remove the known gamma-ray emitters located around the GC in order
to reveal the TeV morphology of the extended emission inside that region.
  Results. No effect of the G2 object on the VHE gamma-ray emission from the GC
was detected during the 4 year observation campaign. We confirm previous
measurements of the VHE spectrum of Sagittarius A*, and do not detect any
significant variability of the emission from the source. Furthermore, the known
VHE gamma-ray emitter at the location of the supernova remnant G0.9+0.1 was
detected, as well as the recently discovered VHE source close to the GG radio
Arc.


title: Structured Prediction by Conditional Risk Minimization

abstract:
  We propose a general approach for supervised learning with structured output
spaces, such as combinatorial and polyhedral sets, that is based on minimizing
estimated conditional risk functions. Given a loss function defined over pairs
of output labels, we first estimate the conditional risk function by solving a
(possibly infinite) collection of regularized least squares problems. A
prediction is made by solving an inference problem that minimizes the estimated
conditional risk function over the output space. We show that this approach
enables, in some cases, efficient training and inference without explicitly
introducing a convex surrogate for the original loss function, even when it is
discontinuous. Empirical evaluations on real-world and synthetic data sets
demonstrate the effectiveness of our method in adapting to a variety of loss
functions.


title: The bitangential matrix Nevanlinna-Pick interpolation problem revisited

abstract:
  We revisit four approaches to the BiTangential Operator Argument
Nevanlinna-Pick (BTOA-NP) interpolation theorem on the right half plane: (1)
the state-space approach of Ball-Gohberg-Rodman, (2) the Fundamental Matrix
Inequality approach of the Potapov school, (3) a reproducing kernel space
interpretation for the solution criterion, and (4) the
Grassmannian/Kre\u{\i}n-space geometry approach of Ball-Helton. These four
approaches lead to three distinct solution criteria which therefore must be
equivalent to each other. We give alternative concrete direct proofs of each of
these latter equivalences. In the final section we show how all the results
extend to the case where one seeks to characterize interpolants in the
Kre\u{\i}n-Langer generalized Schur class $\cS_{\kappa}$ of meromorphic matrix
functions on the right half plane, with the integer $\kappa$ as small as
possible.


title: Risk-Sensitive Learning and Pricing for Demand Response

abstract:
  We consider the setting in which an electric power utility seeks to curtail
its peak electricity demand by offering a fixed group of customers a uniform
price for reductions in consumption relative to their predetermined baselines.
The underlying demand curve, which describes the aggregate reduction in
consumption in response to the offered price, is assumed to be affine and
subject to unobservable random shocks. Assuming that both the parameters of the
demand curve and the distribution of the random shocks are initially unknown to
the utility, we investigate the extent to which the utility might dynamically
adjust its offered prices to maximize its cumulative risk-sensitive payoff over
a finite number of $T$ days. In order to do so effectively, the utility must
design its pricing policy to balance the tradeoff between the need to learn the
unknown demand model (exploration) and maximize its payoff (exploitation) over
time. In this paper, we propose such a pricing policy, which is shown to
exhibit an expected payoff loss over $T$ days that is at most
$O(\sqrt{T}\log(T))$, relative to an oracle pricing policy that knows the
underlying demand model. Moreover, the proposed pricing policy is shown to
yield a sequence of prices that converge to the oracle optimal prices in the
mean square sense.


title:
On geometric conditions for reduction of the Moreau sweeping process to
  the Prandtl-Ishlinskii operator

abstract:
  The sweeping process was proposed by J. J. Moreau as a general mathematical
formalism for quasistatic processes in elastoplastic bodies. This formalism
deals with connected Prandtl's elastic-ideal plastic springs, which can form a
system with an arbitrarily complex topology. The model describes the complex
relationship between stresses and elongations of the springs. On the other
hand, the Prandtl-Ishlinskii model assumes a very simple connection of springs.
This model results in an input-output operator, which has many good
mathematical properties. It turns out that the sweeping processes can be
reducible to the Prandtl-Ishlinskii operator even if the topology of the system
of springs is complex. In this work, we analyze the conditions for such
reducibility.


title: Interpreting Finite Automata for Sequential Data

abstract:
  Automaton models are often seen as interpretable models. Interpretability
itself is not well defined: it remains unclear what interpretability means
without first explicitly specifying objectives or desired attributes. In this
paper, we identify the key properties used to interpret automata and propose a
modification of a state-merging approach to learn variants of finite state
automata. We apply the approach to problems beyond typical grammar inference
tasks. Additionally, we cover several use-cases for prediction, classification,
and clustering on sequential data in both supervised and unsupervised scenarios
to show how the identified key properties are applicable in a wide range of
contexts.


title:
Terahertz Spectrometer of Wavelength Dimensions Based on Extraordinary
  Transmission

abstract:
  Subwavelength-slotted parallel plate waveguides exhibit a localized
electromagnetic resonance bound to the slits at a frequency slightly below the
transverse electric cutoff [R. Merlin, Phys. Rev. X 2, 031015 (2012)]. The
resonance is long-lived and, as opposed to the vanishingly small transmission
shown by a single sub-wavelength aperture, it gives perfect transmission for
perfectly-conducting plates. We show that the aperture-supported resonances of
a pair of slotted copper plates have long lifetimes at THz frequencies. Finite
element method calculations show that these bound resonances can have quality
factors greater than 100. Effects of plate length and imperfect parallel
alignment are also discussed. Using THz time domain spectroscopy, we measured
the transmission of a broadband pulse through a test structure for several
plate separations. These results suggest that the slotted waveguide can
function as a highly compact THz spectrometer.


title: Manipulability of consular election rules

abstract:
  The Gibbard-Satterthwaite theorem is a cornerstone of social choice theory,
stating that an onto social choice function cannot be both strategy-proof and
non-dictatorial if the number of alternatives is at least three. The
Duggan-Schwartz theorem proves an analogue in the case of set-valued elections:
if the function is onto with respect to singletons, and can be manipulated by
neither an optimist nor a pessimist, it must have a weak dictator. However, the
assumption that the function is onto with respect to singletons makes the
Duggan-Schwartz theorem inapplicable to elections which necessarily select a
committee with multiple members. In this paper we make a start on this problem
by considering elections which elect a committee of size two (such as the
consulship of ancient Rome). We establish that if such a consular election rule
cannot be expressed as the union of two disjoint social choice functions, then
strategy-proofness implies the existence of a dictator. Although we suspect
that a similar result holds for larger sized committees, there appear to be
many obstacles to proving it, which we discuss in detail.


title: Generation of discrete random variables in scalable frameworks

abstract:
  In this paper, we face the problem of simulating discrete random variables
with general and varying distributions in a scalable framework, where fully
parallelizable operations should be preferred. The new paradigm is inspired by
the context of discrete choice models. Compared to classical algorithms, we add
parallelized randomness, and we leave the final simulation of the random
variable to a single associative operation. We characterize the set of
algorithms that work in this way, and those algorithms that may have an
additive or multiplicative local noise. As a consequence, we could define a
natural way to solve some popular simulation problems.


title: Superradiance with an ensemble of superconducting flux qubits

abstract:
  Superconducting flux qubits are a promising candidate for realizing quantum
information processing and quantum simulations. Such devices behave like
artificial atoms, with the advantage that one can easily tune the "atoms"
internal properties. Here, by harnessing this flexibility, we propose a
technique to minimize the inhomogeneous broadening of a large ensemble of flux
qubits by tuning only the external flux. In addition, as an example of
many-body physics in such an ensemble, we show how to observe superradiance,
and its quadratic scaling with ensemble size, using a tailored microwave
control pulse that takes advantage of the inhomogeneous broadening itself to
excite only a sub-ensemble of the qubits. Our scheme opens up an approach to
using superconducting circuits to explore the properties of quantum many-body
systems.


title: Two statements of the Duggan-Schwartz theorem

abstract:
  The Duggan-Schwartz theorem (Duggan and Schwartz, 1992) is a famous result
concerning strategy-proof social choice correspondences, often stated as "A
social choice correspondence that can be manipulated by neither an optimist nor
a pessimist has a weak dictator". However, this formulation is actually due to
Taylor (2002), and the original theorem, at face value, looks rather different.
In this note we show that the two are in fact equivalent.


title: From Scalar Field Theories to Supersymmetric Quantum Mechanics

abstract:
  In this work we report a new result that appears when one investigates the
route that starts from a scalar field theory and ends on a supersymmetric
quantum mechanics. The subject has been studied before in several distinct ways
and here we unveil an interesting novelty, showing that the same scalar field
model may describe distinct quantum mechanical problems.


title:
$\bar{D}\Sigma^*_c$ and $\bar{D}^*\Sigma_c$ interactions and LHCb
  pentaquarks

abstract:
  Recently, LHCb collaboration reported the observation of two hidden-charmed
resonances $P_c(4380)$ and $P_c(4450)$ consistent with hidden-charmed
pentaquarks. We perform a dynamical investigation about the
$\bar{D}\Sigma_c^*(2520)$ and $\bar{D}^*\Sigma_c(2455)$ interactions which are
described by the meson exchanges in a quasipotential Bethe-Salpeter equation
approach. Two poles around $4450$ and $4390$ MeV are produced from the
$\bar{D}^*\Sigma_c(2455)$ interaction with spin parities $3/2^-$ and $5/2^+$,
respectively. The peak for $5/2^+$ state has a comparable hight as that of
$3/2^-$ state in the $J/\psi p$ invariant mass spectrum. Another bound state
with spin-parity $J^P=3/2^-$ is produced from the $\bar{D}\Sigma^*_c(2520)$
interaction. Such results suggest that the narrower LHCb pentaquark $P_c(4450)$
can be well interpreted as a $5/2^+$ $\bar{D}^*\Sigma_c(2455)$ molecular state
while the $P_c(4380)$ is a $3/2^-$ $\bar{D}^*\Sigma_c(2455)$ molecular state
mixed with other secondary origins.


title:
On the existence of Pareto solutions for polynomial vector optimization
  problems

abstract:
  We are interested in the existence of Pareto solutions to the vector
optimization problem $$\text{Min}_{\,\mathbb{R}^m_+} \{f(x) \,|\, x\in
\mathbb{R}^n\},$$ where $f\colon\mathbb{R}^n\to \mathbb{R}^m$ is a polynomial
map. By using the {\em tangency variety} of $f$ we first construct a
semi-algebraic set of dimension at most $m - 1$ containing the set of Pareto
values of the problem. Then we establish connections between the Palais--Smale
conditions, $M$-tameness, and properness for the map $f$. Based on these
results, we provide some sufficient conditions for the existence of Pareto
solutions of the problem. We also introduce a generic class of polynomial
vector optimization problems having at least one Pareto solution.


title: A Simple Power Analysis Attack on the Twofish Key Schedule

abstract:
  This paper introduces an SPA power attack on the 8-bit implementation of the
Twofish block cipher. The attack is able to unequivocally recover the secret
key even under substantial amounts of error. An initial algorithm is described
using exhaustive search on error free data. An error resistant algorithm is
later described. It employs several threshold preprocessing stages followed by
a combined approach of least mean squares and an optimized Hamming mask search.
Further analysis of 32 and 64-bit Twofish implementations reveals that they are
similarly vulnerable to the described SPA attack.


title:
Implementation of Bilinear Hamiltonian Interactions between Linear
  Quantum Stochastic Systems via Feedback

abstract:
  A number of recent works employ bilinear Hamiltonian interactions between
Linear Quantum Stochastic Systems (LQSSs). Contrary to naturally occurring
Hamiltonian interactions between physical systems, such interactions must be
engineered. In this work, we propose a simple model for the implementation of
an arbitrary bilinear interaction between two given LQSSs via a feedback
interconnection.


title: The Total Acquisition Number of Random Geometric Graphs

abstract:
  Let $G$ be a graph in which each vertex initially has weight 1. In each step,
the weight from a vertex $u$ to a neighbouring vertex $v$ can be moved,
provided that the weight on $v$ is at least as large as the weight on $u$. The
total acquisition number of $G$, denoted by $a_t(G)$, is the minimum
cardinality of the set of vertices with positive weight at the end of the
process. In this paper, we investigate random geometric graphs $G(n,r)$ with
$n$ vertices distributed u.a.r. in $[0,\sqrt{n}]^2$ and two vertices being
adjacent if and only if their distance is at most $r$. We show that
asymptotically almost surely $a_t(G(n,r)) = \Theta( n / (r \lg r)^2)$ for the
whole range of $r=r_n \ge 1$ such that $r \lg r \le \sqrt{n}$. By monotonicity,
asymptotically almost surely $a_t(G(n,r)) = \Theta(n)$ if $r < 1$, and
$a_t(G(n,r)) = \Theta(1)$ if $r \lg r > \sqrt{n}$.


title:
Development of an EKF-based localization algorithm using compass sensor
  and LRF

abstract:
  This paper presents the implementation of a perceptual system for a mobile
robot. The system is designed and installed with modern sensors and multi-point
communication channels. The goal is to equip the robot with a high level of
perception to support a wide range of navigating applications including
Internet-based telecontrol, semi-autonomy, and autonomy. Due to uncertainties
of acquiring data, a sensor fusion model is developed, in which heterogeneous
measured data including odometry, compass heading and laser range is combined
to get an optimal estimate in a statistical sense. The combination is carried
out by an extended Kalman filter. Experimental results indicate that based on
the system, the robot localization is enhanced and sufficient for navigation
tasks.


title:
Robust fractional quantum Hall states and continuous quantum phase
  transitions in a half-filled bilayer graphene Landau level

abstract:
  Nonabelian anyons offer the prospect of storing quantum information in a
topological qubit protected from decoherence, with the degree of protection
determined by the energy gap separating the topological vacuum from its low
lying excitations. Originally proposed to occur in quantum wells in high
magnetic fields, experimental systems thought to harbor nonabelian anyons range
from p-wave superfluids to superconducting systems with strong spin orbit
coupling. However, all of these systems are characterized by small energy gaps,
and despite several decades of experimental work, definitive evidence for
nonabelian anyons remains elusive. Here, we report the observation of arobust,
incompressible even-denominator fractional quantum Hall phase in a new
generation of dual-gated, hexagonal boron nitride encapsulated bilayer graphene
samples. Numerical simulations suggest that this state is in the Pfaffian phase
and hosts nonabelian anyons, and the measured energy gaps are several times
larger than those observed in other systems. Moreover, the unique electronic
structure of bilayer graphene endows the electron system with two new control
parameters. Magnetic field continuously tunes the effective electron
interactions, changing the even-denominator gap non-monotonically and
consistent with predictions that a transition between the Pfaffian phase and
the composite Fermi liquid (CFL) occurs just beyond the experimentally explored
magnetic field range. Electric field, meanwhile, tunes crossings between levels
from different valleys. By directly measuring the valley polarization, we
observe a continuous transition from an incompressible to a compressible phase
at half-filling mediated by an unexpected incompressible, yet polarizable,
intermediate phase. Valley conservation implies this phase is an electrical
insulator with gapless neutral excitations.


title:
Multi-sensor perceptual system for mobile robot and sensor fusion-based
  localization

abstract:
  This paper presents an Extended Kalman Filter (EKF) approach to localize a
mobile robot with two quadrature encoders, a compass sensor, a laser range
finder (LRF) and an omni-directional camera. The prediction step is performed
by employing the kinematic model of the robot as well as estimating the input
noise covariance matrix as being proportional to the wheel's angular speed. At
the correction step, the measurements from all sensors including incremental
pulses of the encoders, line segments of the LRF, robot orientation of the
compass and deflection angular of the omni-directional camera are fused.
Experiments in an indoor structured environment were implemented and the good
localization results prove the effectiveness and applicability of the
algorithm.


title:
Tree Space Prototypes: Another Look at Making Tree Ensembles
  Interpretable

abstract:
  Ensembles of decision trees perform well on many problems, but are not
interpretable. In contrast to existing approaches in interpretability that
focus on explaining relationships between features and predictions, we propose
an alternative approach to interpret tree ensemble classifiers by surfacing
representative points for each class -- prototypes. We introduce a new distance
for Gradient Boosted Tree models, and propose new, adaptive prototype selection
methods with theoretical guarantees, with the flexibility to choose a different
number of prototypes in each class. We demonstrate our methods on random
forests and gradient boosted trees, showing that the prototypes can perform as
well as or even better than the original tree ensemble when used as a
nearest-prototype classifier. In a user study, humans were better at predicting
the output of a tree ensemble classifier when using prototypes than when using
Shapley values, a popular feature attribution method. Hence, prototypes present
a viable alternative to feature-based explanations for tree ensembles.


title: Complex structure-induced deformations of sigma-models

abstract:
  We describe a deformation of the principal chiral model (with an
even-dimensional target space G) by a B-field proportional to the K\"ahler form
on the target space. The equations of motion of the deformed model admit a
zero-curvature representation. As a simplest example, we consider the case of
G=S^1 x S^3. We also apply a variant of the construction to a deformation of
the AdS_3 x S^3 x S^1 (super-)sigma-model.


title:
Ground Based Low-Frequency Gravitational-wave Detector With Multiple
  Outputs

abstract:
  We have developed a new gravitaional-wave (GW) detector, TOrsion-Bar Antenna
(TOBA), with multiple-output configuration. TOBA is a detector with bar-shaped
test masses that rotate by the tidal force of the GWs. In our detector, three
independent information about the GW signals can be derived by monitoring
multiple rotational degrees of freedom, i.e., horizontal rotations and vertical
rotations of the bars. Since the three outputs have different antenna pattern
functions, the multi-output system improves the detection rate and the
parameter estimation accuracy. It is effective in order to obtain further
details of the GW sources, such as population and directions. We successfully
operated the multi-output detector continuously for more than 24 hours with
stable data quality. Also, the sensitivity of one of the signals is improved to
be $1 \times 10^{-10}$ ${\rm Hz}^{-1/2}$ at 3 Hz by the combination of the
passive and active vibration isolation systems, while sensitivities to possible
GW signals derived from the vertical rotations are worse than that from the
horizontal rotation.


title:
Repr\'esentations galoisiennes di\'edrales et formes \`a multiplication
  complexe

abstract:
  Pour une repr\'esentation galoisienne di\'edrale en caract\'eristique l on
\'etablit (sous certaines hypoth\`eses) l'existence d'une newform \`a
multiplication complexe, dont on contr\^ole le poids, le niveau et le
caract\`ere, telle que la repr\'esentation l-adique associ\'ee est congrue
modulo l \`a celle de d\'epart.
  Given a dihedral Galois representation in characteristic l, we establish
(under some assumption) the existence of a CM newform, whose weight, level and
Nebentypus we pin down, such that its l-adic representation is congruent modulo
l to the one we started with.


title: Max-Margin Deep Generative Models for (Semi-)Supervised Learning

abstract:
  Deep generative models (DGMs) are effective on learning multilayered
representations of complex data and performing inference of input data by
exploring the generative ability. However, it is relatively insufficient to
empower the discriminative ability of DGMs on making accurate predictions. This
paper presents max-margin deep generative models (mmDGMs) and a
class-conditional variant (mmDCGMs), which explore the strongly discriminative
principle of max-margin learning to improve the predictive performance of DGMs
in both supervised and semi-supervised learning, while retaining the generative
capability. In semi-supervised learning, we use the predictions of a max-margin
classifier as the missing labels instead of performing full posterior inference
for efficiency; we also introduce additional max-margin and label-balance
regularization terms of unlabeled data for effectiveness. We develop an
efficient doubly stochastic subgradient algorithm for the piecewise linear
objectives in different settings. Empirical results on various datasets
demonstrate that: (1) max-margin learning can significantly improve the
prediction performance of DGMs and meanwhile retain the generative ability; (2)
in supervised learning, mmDGMs are competitive to the best fully discriminative
networks when employing convolutional neural networks as the generative and
recognition models; and (3) in semi-supervised learning, mmDCGMs can perform
efficient inference and achieve state-of-the-art classification results on
several benchmarks.


title:
The complete classification of unital graph $C^*$-algebras: Geometric
  and strong

abstract:
  We provide a complete classification of the class of unital graph
$C^*$-algebras - prominently containing the full family of Cuntz-Krieger
algebras - showing that Morita equivalence in this case is determined by
ordered, filtered $K$-theory. The classification result is geometric in the
sense that it establishes that any Morita equivalence between $C^*(E)$ and
$C^*(F)$ in this class can be realized by a sequence of moves leading from $E$
to $F$, in a way resembling the role of Reidemeister moves on knots. As a key
ingredient, we introduce a new class of such moves, establish that they leave
the graph algebras invariant, and prove that after this augmentation, the list
of moves becomes complete in the sense described above.
  Along the way, we prove that every ordered, reduced filtered $K$-theory
isomorphism can be lifted to an isomorphism between the stabilized
$C^*$-algebras - and, as a consequence, that every ordered, reduced filtered
$K$-theory isomorphism preserving the class of the unit comes from a
$*$-isomorphism between the unital graph $C^*$-algebras themselves.
  It follows that the question of Morita equivalence amongst unital graph
$C^*$-algebras is a decidable one. As immediate examples of applications of our
results we revisit the classification problem for quantum lens spaces and
verify, in the unital case, the Abrams-Tomforde conjectures.


title: On the number of harmonic frames

abstract:
  There is a finite number $h_{n,d}$ of tight frames of $n$ distinct vectors
for $\mathbb{C}^d$ which are the orbit of a vector under a unitary action of
the cyclic group $\mathbb{Z}_n$. These cyclic harmonic frames (or geometrically
uniform tight frames) are used in signal analysis and quantum information
theory, and provide many tight frames of particular interest. Here we
investigate the conjecture that $h_{n,d}$ grows like $n^{d-1}$. By using a
result of Laurent which describes the set of solutions of algebraic equations
in roots of unity, we prove the asymptotic estimate $$ h_{n,d} \approx {n^d
\over \varphi(n)}\ge n^{d-1}, \qquad n\to\infty. $$ By using a group theoretic
approach, we also give some exact formulas for $h_{n,d}$, and estimate the
number of cyclic harmonic frames up to projective unitary equivalence.


title: Reference frame independent Einstein-Podolsky-Rosen steering

abstract:
  Protocols for testing or exploiting quantum correlations-such as
entanglement, Bell nonlocality, and Einstein-Podolsky-Rosen steering- generally
assume a common reference frame between two parties. Establishing such a frame
is resource-intensive, and can be technically demanding for distant parties.
While Bell nonlocality can be demonstrated with high probability for a large
class of two-qubit entangled states when the parties have one or no shared
reference direction, the degree of observed nonlocality is
measurement-orientation dependent and can be arbitrarily small. In contrast, we
theoretically prove that steering can be demonstrated with 100% probability,
for a larger class of states, in a rotationally-invariant manner, and
experimentally demonstrate rotationally-invariant steering in a variety of
cases. We also show, by comparing with the steering inequality of Cavalcanti et
al. [J. Opt. Soc. Am. B 32, A74 (2015)], that the steering inequality we derive
is the optimal rotationally invariant one for the case of two settings per side
and two-qubit states having maximally mixed reduced (local) states.


title:
Design and Operational Experience of a Microwave Cavity Axion Detector
  for the 20-100 micro-eV Range

abstract:
  We describe a dark matter axion detector designed, constructed, and operated
both as an innovation platform for new cavity and amplifier technologies and as
a data pathfinder in the $5 - 25$ GHz range ($\sim20-100\: \mu$eV). The
platform is small but flexible to facilitate the development of new microwave
cavity and amplifier concepts in an operational environment. The experiment has
recently completed its first data production; it is the first microwave cavity
axion search to deploy a Josephson parametric amplifier and a dilution
refrigerator to achieve near-quantum limited performance.


title:
Outage Effective Capacity of Buffer-Aided Diamond Relay Systems Using
  HARQ with Incremental Redundancy

abstract:
  In this paper, transmission over buffer-aided diamond relay systems under
statistical quality of service (QoS) constraints is studied. The statistical
QoS constraints are imposed as limitations on delay violation probabilities. In
the absence of channel state information (CSI) at the transmitter, truncated
hybrid automatic repeat request-incremental redundancy (HARQ-IR) is
incorporated to make better use of the wireless channel and the resources for
each communication link. The packets that cannot be successfully received upon
the maximum number of transmissions will be removed from buffer, i.e., outage
occurs. The \emph{outage effective capacity} of a communication link is defined
as the maximum constant arrival rate to the source that can be supported by the
\emph{goodput} departure processes, i.e., the departure that can be
successfully received by the receiver. Then, the outage effective capacity for
the buffer-aided diamond relay system is obtained for HARQ-IR incorporated
transmission strategy under the \emph{end-to-end} delay constraints. In
comparison with the DF protocol with perfect CSI at the transmitters, it is
shown that HARQ-IR can achieve superior performance when the SNR levels at the
relay are not so large or when the delay constraints are stringent.


title: Evidence for a Hard Ionizing Spectrum from a z=6.11 Stellar Population

abstract:
  We present the Magellan/FIRE detection of highly-ionized CIV 1550 and OIII]
1666 in a deep infrared spectrum of the z=6.11 gravitationally lensed low-mass
galaxy RXC J2248.7-4431-ID3, which has previously-known Lyman-alpha. No
corresponding emission is detected at the expected location of HeII 1640. The
upper limit on HeII paired with detection of OIII] and CIV constrains possible
ionization scenarios. Production of CIV and OIII] requires ionizing photons of
2.5-3.5 Ryd, but once in that state their multiplet emission is powered by
collisional excitation at lower energies (~0.5 Ryd). As a pure recombination
line, HeII emission is powered by 4 Ryd ionizing photons. The data therefore
require a spectrum with significant power at 3.5 Ryd but a rapid drop toward
4.0 Ryd. This hard spectrum with a steep drop is characteristic of
low-metallicity stellar populations, and less consistent with soft AGN
excitation, which features more 4 Ryd photons and hence higher HeII flux. The
conclusions based on ratios of metal line detections to Helium non-detection
are strengthened if the gas metallicity is low. RXJ2248-ID3 adds to the growing
handful of reionization-era galaxies with UV emission line ratios distinct from
the general z=2-3 population, in a way that suggests hard ionizing spectra that
do not necessarily originate in AGN.


title: Random number generation with cosmic photons

abstract:
  Random numbers are indispensable for a variety of applications ranging from
testing physics foundation to information encryption. In particular,
nonlocality tests provide a strong evidence to our current understanding of
nature -- quantum mechanics. All the random number generators (RNG) used for
the existing tests are constructed locally, making the test results vulnerable
to the freedom-of-choice loophole. We report an experimental realization of
RNGs based on the arrival time of cosmic photons. The measurement outcomes (raw
data) pass the standard NIST statistical test suite. We present a realistic
design to employ these RNGs in a Bell test experiment, which addresses the
freedom-of-choice loophole.


title: A note on Galois embeddings of abelian varieties

abstract:
  In this note we show that if an abelian variety possesses a Galois embedding
into some projective space, then it must be isogenous to the self product of an
elliptic curve. We prove moreover that the self product of an elliptic curve
always has infinitely many Galois embeddings.


title:
Sub-Cycle Optical Response Caused by Dressed State with Phase-Locked
  Wavefunctions

abstract:
  The coherent interaction of light with matter imprints the phase information
of the light field on the wavefunction of the photon-dressed electronic state.
Driving electric field, together with a stable phase that is associated with
the optical probe pulses, enables the role of the dressed state in the optical
response to be investigated. We observed optical absorption strengths modulated
on a sub-cycle timescale in a GaAs quantum well in the presence of a
multi-cycle terahertz driving pulse using a near-infrared probe pulse. The
measurements were in good agreement with the analytical formula that accounts
for the optical susceptibilities caused by the dressed state of excitons, which
indicates that the output probe intensity was coherently reshaped by the
excitonic sideband emissions.


title: Particle in a box with a time-dependent $\delta$-function potential

abstract:
  In quantum information processing, one often considers inserting a barrier
into a box containing a particle to generate one bit of Shannon entropy. We
formulate this problem as a one-dimensional Schr\"{o}dinger equation with a
time-dependent $\delta$-function potential. It is a natural generalization of
the particle in a box, a canonical example of quantum mechanics, and we present
analytic and numerical investigations on this problem. After deriving an exact
Volterra-type integral equation, composed of an infinite sum of modes, we show
that approximate formulas with the lowest-frequency modes correctly capture the
qualitative behavior of the wave function. If we take into account hundreds of
modes, our numerical calculation shows that the quantum adiabatic theorem
actually gives a very good approximation even if the barrier height diverges
within finite time, as long as it is sufficiently longer than the
characteristic time scale of the particle. In particular, if the barrier is
slowly inserted at an asymmetric position, the particle is localized by the
insertion itself, in accordance with a prediction of the adiabatic theorem. On
the other hand, when the barrier is inserted quickly, the wave function becomes
rugged after the insertion because of the energy transfer to the particle.
Regardless of the position of the barrier, the fast insertion leaves the
particle unlocalized so that we can obtain meaningful information by a
which-side measurement. Our numerical procedure provides a precise way to
calculate the wave function throughout the process, from which one can estimate
the amount of this information for an arbitrary insertion protocol.


title:
The interface between Sr$_2$RuO$_4$ and Ru-metal inclusion--Implications
  for its superconductivity

abstract:
  Under various conditions of the growth process, when the presumably
unconventional superconductor Sr$_2$RuO$_4$ (SRO) contains micro-inclusions of
Ru metal, the superconducting critical temperature increases significantly. An
STEM study shows a sharp interface geometry which allows crystals of SRO and of
Ru-metal to grow side by side by forming a commensurate superlattice structure
at the interface. In an attempt to shed light as to why this happens, we
investigated the atomic structure and electronic properties of the interface
between the oxide and the metal micro-inclusions using density functional
theory (DFT) calculations. Our results support the observed structure
indicating that it is energetically favored over other types of Ru-metal/SRO
interfaces. We find that a $t_{2g}$-$e_g$ orbital mixing occurs at the
interface with significantly enhanced magnetic moments. Based on our findings,
we argue that an inclusion mediated interlayer coupling reduces phase
fluctuations of the superconducting order parameter which could explain the
observed enhancement of the superconducting critical temperature in SRO samples
containing micro-inclusions.


title:
Search for the $0^{--}$ Glueball in $\Upsilon(1S)$ and $\Upsilon(2S)$
  decays

abstract:
  We report the first search for the $J^{PC}=0^{--}$ glueball in $\Upsilon(1S)$
and $\Upsilon(2S)$ decays with data samples of $(102\pm2)$ million and
$(158\pm4)$ million events, respectively, collected with the Belle detector. No
significant signals are observed in any of the proposed production modes, and
the 90\% credibility level upper limits on their branching fractions in
$\Upsilon(1S)$ and $\Upsilon(2S)$ decays are obtained. The inclusive branching
fractions of the $\Upsilon(1S)$ and $\Upsilon(2S)$ decays into final states
with a $\chi_{c1}$ are measured to be $\BR(\Upsilon(1S)\to \chi_{c1}+ anything)
= (1.90\pm 0.43(stat.)\pm 0.14(syst.))\times 10^{-4}$ with an improved
precision over prior measurements and $\BR(\Upsilon(2S)\to \chi_{c1}+ anything)
= (2.24\pm 0.44(stat.)\pm 0.20(syst.))\times 10^{-4}$ for the first time.


title: Higher Moments of Net-Kaon Multiplicity Distributions at STAR

abstract:
  Fluctuations of conserved quantities such as baryon number (B), electric
charge number (Q), and strangeness number (S), are sensitive to the correlation
length and can be used to probe non-gaussian fluctuations near the critical
point. Experimentally, higher moments of the multiplicity distributions have
been used to search for the QCD critical point in heavy-ion collisions. In this
paper, we report the efficiency-corrected cumulants and their ratios of mid-
rapidity (|y| < 0.5) net-kaon multiplicity distributions in Au+Au collisions at
7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV collected in 2010, 2011, and
2014 with STAR at RHIC. The centrality and energy dependence of the cumulants
and their ratios, are presented. Furthermore, the comparisons with baseline
calculations (Poisson) and non-critical-point models (UrQMD) are also
discussed.


title:
Symmetry Parameter Constraints From A Lower Bound On The Neutron-Matter
  Energy

abstract:
  We propose the existence of a lower bound on the energy of pure neutron
matter (PNM) on the basis of unitary-gas considerations. We discuss its
justification from experimental studies of cold atoms as well as from
theoretical studies of neutron matter. We demonstrate that this bound results
in limits to the density-dependent symmetry energy, which is the difference
between the energies of symmetric nuclear matter and PNM. In particular, this
bound leads to a lower limit to the volume symmetry energy parameter $S_0$. In
addition, for assumed values of $S_0$ above this minimum, this bound implies
both upper and lower limits to the symmetry energy slope parameter $L$, which
describes the lowest-order density dependence of the symmetry energy. A lower
bound on the neutron-matter incompressibility is also obtained. These bounds
are found to be consistent with both recent calculations of the energies of PNM
and constraints from nuclear experiments. Our results are significant because
several equations of state that are currently used in astrophysical simulations
of supernovae and neutron star mergers, as well as in nuclear physics
simulations of heavy-ion collisions, have symmetry energy parameters that
violate these bounds. Furthermore, below the nuclear saturation density, the
bound on neutron-matter energies leads to a lower limit to the
density-dependent symmetry energy, which leads to upper limits to the nuclear
surface symmetry parameter and the neutron-star crust-core boundary. We also
obtain a lower limit to the neutron-skin thicknesses of neutron-rich nuclei.
Above the nuclear saturation density, the bound on neutron-matter energies also
leads to an upper limit to the symmetry energy, with implications for
neutron-star cooling via the direct Urca process.


title:
Energy Dependence of Moments of Net-Proton, Net-Kaon, and Net-Charge
  Multiplicity Distributions at STAR

abstract:
  One of the main goals of the RHIC Beam Energy Scan (BES) program is to study
the QCD phase structure, which includes the search for the QCD critical point,
over a wide range of chemical potential. Theoretical calculations predict that
fluctuations of conserved quantities, such as baryon number (B), charge (Q),
and strangeness (S), are sensitive to the correlation length of the dynamical
system. Experimentally, higher moments of multiplicity distributions have been
utilized to search for the QCD critical point in heavy-ion collisions. In this
paper, we report recent efficiency-corrected cumulants and cumulants ratios of
the net- proton, net-kaon, and net-charge multiplicity distributions in Au+Au
collisions at 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV collected in the
years 2010, 2011, and 2014 with STAR at RHIC. The centrality and energy
dependence of the cumulants up to the fourth order, as well as their ratios,
are presented. Furthermore, the comparisons with baseline calculations
(Poisson) and non-critical-point models (UrQMD) will also be discussed.


title: Leveraging Citation Networks to Visualize Scholarly Influence Over Time

abstract:
  Assessing the influence of a scholar's work is an important task for funding
organizations, academic departments, and researchers. Common methods, such as
measures of citation counts, can ignore much of the nuance and
multidimensionality of scholarly influence. We present an approach for
generating dynamic visualizations of scholars' careers. This approach uses an
animated node-link diagram showing the citation network accumulated around the
researcher over the course of the career in concert with key indicators,
highlighting influence both within and across fields. We developed our design
in collaboration with one funding organization---the Pew Biomedical Scholars
program---but the methods are generalizable to visualizations of scholarly
influence. We applied the design method to the Microsoft Academic Graph, which
includes more than 120 million publications. We validate our abstractions
throughout the process through collaboration with the Pew Biomedical Scholars
program officers and summative evaluations with their scholars.


title:
Cascaded Neural Networks with Selective Classifiers and its evaluation
  using Lung X-ray CT Images

abstract:
  Lung nodule detection is a class imbalanced problem because nodules are found
with much lower frequency than non-nodules. In the class imbalanced problem,
conventional classifiers tend to be overwhelmed by the majority class and
ignore the minority class. We therefore propose cascaded convolutional neural
networks to cope with the class imbalanced problem. In the proposed approach,
cascaded convolutional neural networks that perform as selective classifiers
filter out obvious non-nodules. Successively, a convolutional neural network
trained with a balanced data set calculates nodule probabilities. The proposed
method achieved the detection sensitivity of 85.3% and 90.7% at 1 and 4 false
positives per scan in FROC curve, respectively.


title:
On extremal multiplicative Zagreb indices of trees with given number of
  vertices of maximum degree

abstract:
  The first multiplicative Zagreb index of a graph $G$ is the product of the
square of every vertex degree, while the second multiplicative Zagreb index is
the product of the products of degrees of pairs of adjacent vertices. In this
paper, we explore the trees in terms of given number of vertices of maximum
degree. The maximum and minimum values of $\prod_1(G) $ and $\prod_2(G) $ of
trees with arbitrary number of maximum degree are provided. In addition, the
corresponding extremal graphs are characterized.


title: A New Approach to Laplacian Solvers and Flow Problems

abstract:
  This paper investigates the behavior of the Min-Sum message passing scheme to
solve systems of linear equations in the Laplacian matrices of graphs and to
compute electric flows. Voltage and flow problems involve the minimization of
quadratic functions and are fundamental primitives that arise in several
domains. Algorithms that have been proposed are typically centralized and
involve multiple graph-theoretic constructions or sampling mechanisms that make
them difficult to implement and analyze. On the other hand, message passing
routines are distributed, simple, and easy to implement. In this paper we
establish a framework to analyze Min-Sum to solve voltage and flow problems. We
characterize the error committed by the algorithm on general weighted graphs in
terms of hitting times of random walks defined on the computation trees that
support the operations of the algorithms with time. For $d$-regular graphs with
equal weights, we show that the convergence of the algorithms is controlled by
the total variation distance between the distributions of non-backtracking
random walks defined on the original graph that start from neighboring nodes.
The framework that we introduce extends the analysis of Min-Sum to settings
where the contraction arguments previously considered in the literature (based
on the assumption of walk summability or scaled diagonal dominance) can not be
used, possibly in the presence of constraints.


title:
A Natural Language Query Interface for Searching Personal Information on
  Smartwatches

abstract:
  Currently, personal assistant systems, run on smartphones and use natural
language interfaces. However, these systems rely mostly on the web for finding
information. Mobile and wearable devices can collect an enormous amount of
contextual personal data such as sleep and physical activities. These
information objects and their applications are known as quantified-self, mobile
health or personal informatics, and they can be used to provide a deeper
insight into our behavior. To our knowledge, existing personal assistant
systems do not support all types of quantified-self queries. In response to
this, we have undertaken a user study to analyze a set of "textual
questions/queries" that users have used to search their quantified-self or
mobile health data. Through analyzing these questions, we have constructed a
light-weight natural language based query interface, including a text parser
algorithm and a user interface, to process the users' queries that have been
used for searching quantified-self information. This query interface has been
designed to operate on small devices, i.e. smartwatches, as well as augmenting
the personal assistant systems by allowing them to process end users' natural
language queries about their quantified-self data.


title:
Potential landscape of high dimensional nonlinear stochastic dynamics
  with large noise

abstract:
  Quantifying stochastic processes is essential to understand many natural
phenomena, particularly in biology, including cell-fate decision in
developmental processes as well as genesis and progression of cancers. While
various attempts have been made to construct potential landscape in high
dimensional systems and to estimate rare transitions, they are practically
limited to cases where either noise is small or detailed balance condition
holds. A general and practical approach to investigate nonequilibrium systems
typically subject to finite or large multiplicative noise and breakdown of
detailed balance remains elusive. Here, we formulate a computational framework
to address this important problem. The current approach is based on a least
action principle to efficiently calculate potential landscapes of systems under
arbitrary noise strength and without detailed balance. With the deterministic
stability structure preserving A-type stochastic integration, the potential
barrier between different (local) stable stables is directly computable. We
demonstrate our approach in a numerically accurate manner through solvable
examples. We further apply the method to investigate the role of noise on tumor
heterogeneity in a 38 dimensional network model for prostate cancer, and
provide a new strategy on controlling cell populations by manipulating noise
strength.


title: Some results on the eventual paracanonical maps

abstract:
  The eventual paracanonical map was introduced by Barja, Pardini, and Stoppino
in order to prove refined Severi-type inequalities. We study the general
structures of the eventual paracanonical maps by generic vanishing theory. In
particular, we obtain rather complete descriptions of the eventual
paracanonical maps of surfaces and threefolds.


title: Magnetically guided Cesium interferometer for inertial sensing

abstract:
  In this paper we demonstrate a magnetically guided Cesium (Cs) atom
interferometer in the Talbot-Lau regime for inertial sensing with two
interferometer schemes, Mach-Zenhder and Ramsey-Borde. The recoil frequency of
the Cs atoms and the acceleration along the waveguide symmetry axis is
measured. An acceleration measurement uncertainty of $7\times10^{-5}$ m/s$^{2}$
is achieved. We also realize an enclosed area of $0.018$ mm$^{2}$ for rotation
measurement. As the first reported magnetically guided Cs atom interferometer,
the system limitation and its advantages are discussed.


title: Learning Multi-level Features For Sensor-based Human Action Recognition

abstract:
  This paper proposes a multi-level feature learning framework for human action
recognition using a single body-worn inertial sensor. The framework consists of
three phases, respectively designed to analyze signal-based (low-level),
components (mid-level) and semantic (high-level) information. Low-level
features capture the time and frequency domain property while mid-level
representations learn the composition of the action. The Max-margin Latent
Pattern Learning (MLPL) method is proposed to learn high-level semantic
descriptions of latent action patterns as the output of our framework. The
proposed method achieves the state-of-the-art performances, 88.7%, 98.8% and
72.6% (weighted F1 score) respectively, on Skoda, WISDM and OPP datasets.


title: Faster integer multiplication using plain vanilla FFT primes

abstract:
  Assuming a conjectural upper bound for the least prime in an arithmetic
progression, we show that n-bit integers may be multiplied in O(n log n
4^(log^* n)) bit operations.


title:
Learning Multi-level Deep Representations for Image Emotion
  Classification

abstract:
  In this paper, we propose a new deep network that learns multi-level deep
representations for image emotion classification (MldrNet). Image emotion can
be recognized through image semantics, image aesthetics and low-level visual
features from both global and local views. Existing image emotion
classification works using hand-crafted features or deep features mainly focus
on either low-level visual features or semantic-level image representations
without taking all factors into consideration. The proposed MldrNet combines
deep representations of different levels, i.e. image semantics, image
aesthetics, and low-level visual features to effectively classify the emotion
types of different kinds of images, such as abstract paintings and web images.
Extensive experiments on both Internet images and abstract paintings
demonstrate the proposed method outperforms the state-of-the-art methods using
deep features or hand-crafted features. The proposed approach also outperforms
the state-of-the-art methods with at least 6% performance improvement in terms
of overall classification accuracy.


title: Discrepancy of general symplectic lattices

abstract:
  We consider random lattices taken from the general symplectic ensemble and
count the number of lattice points of a typical lattice in nested families
$B_t$ of certain Borel sets. Our main result is that for almost every general
symplectic lattice, the discrepancy $D(\Lambda,B_t)$ of the lattice point count
with respect to the volumes is $O(vol(B_t)^{-\delta})$. This extends work of W.
Schmidt who gave similar discrepancy bounds for the space of all lattices in
$\mathbb{R}^n$.


title: A beam monitor using silicon pixel sensors for hadron therapy

abstract:
  We report the design and test results of a beam monitor developed for online
monitoring in hadron therapy. The beam monitor uses eight silicon pixel
sensors, \textit{Topmetal-${II}^-$}, as the anode array.
\textit{Topmetal-${II}^-$} is a charge sensor designed in a CMOS 0.35 $\mu$m
technology. Each \textit{Topmetal-${II}^-$} sensor has $72\times72$ pixels and
the pixel size is $83\times83$ $\mu$m$^2$. In our design, the beam passes
through the beam monitor without hitting the electrodes, making the beam
monitor especially suitable for monitoring heavy ion beams. This design also
reduces radiation damage to the beam monitor itself. The beam monitor is tested
with a carbon ion beam at the Heavy Ion Research Facility in Lanzhou (HIRFL).
Results indicate that the beam monitor can measure position, incidence angle
and intensity of the beam with a position resolution better than 20 $\mu$m,
angular resolution about 0.5$^\circ$ and intensity statistical accuracy better
than 2$\%$.


title: A possible four-phase coexistence in a single-component system

abstract:
  For different phases to coexist in equilibrium at constant temperature $T$
and pressure $P$, the condition of equal chemical potential $\mu$ must be
satisfied. This condition dictates that, for a single-component system, the
maximum number of phases that can coexist is three. Historically this is known
as the Gibbs phase rule, and is one of the oldest and venerable rules of
thermodynamics. Here we makes use of the fact that, by varying model
parameters, the Gibbs phase rule can be generalized so that four phases can
coexist even in single-component systems. To systematically search for the
quadruple point, we use a monoatomic system interacting with a Stillinger-Weber
potential with variable tetrahedrality. Our study indicates that the quadruple
point provides novel flexibility in controlling multiple equilibrium phases and
may be realized in systems with tunable interactions, which are nowadays
feasible in several soft matter systems (e.g., patchy colloids).


title:
Revisiting the structure and spectrum of the
  magnetic-reconnection-heated corona in luminous AGNs

abstract:
  It is believed that the hard X-ray emission in the luminous active galactic
nuclei (AGNs) is from the hot corona above the cool accretion disk. However,
the formation of the corona is still debated. Liu et al. investigated the
spectrum of the corona heated by the reconnection of the magnetic field
generated by dynamo action in the thin disk and emerging into the corona as a
result of buoyancy instability. In the present paper, we improve this model to
interpret the observed relation of the hard X-ray spectrum becoming softer at
higher accretion rate in luminous AGNs. The magnetic field is characterized by
$\beta_{\rm 0}$, i.e., the ratio of the sum of gas pressure and radiation
pressure to magnetic pressure in the disk ($\beta_{\rm 0}=(P_{\rm g,d}+P_{\rm
r,d})/P_{\rm B}$). Besides, both the intrinsic disk photons and reprocessed
photons by the disk are included as the seed photons for inverse Compton
scattering. These improvements are crucial for investigating the effect of
magnetic field on the accretion disk-corona when it is not clear whether the
radiation pressure or gas pressure dominates in thin disk. We change the value
of $\beta_{\rm 0}$ in order to constrain the magnetic field in the accretion
disk. We find that the energy fraction released in the corona ($f$) gradually
increases with the decrease of $\beta_{\rm 0}$ for the same accretion rate.
When $\beta_{\rm 0}$ decreases to less than 50, the structure and spectrum of
the disk-corona is independent on accretion rate, which is similar to the hard
spectrum found in Liu et al.(2003). Comparing with the observational results of
the hard X-ray bolometric correction factor in a sample of luminous AGNs, we
suggest that the value of $\beta_{\rm 0}$ is about 100-200 for $\alpha=0.3$ and
the energy fraction $f$ should be larger than $30\%$ for hard X-ray emission.


title: $N_f=1+2$ mass dependence of the topological susceptibility

abstract:
  A massless up quark has long been proposed as a solution to the strong CP
problem. While this solution is sometimes thought to have been excluded, it is
actually still ill-defined. In this work, we study the mass dependence of the
physical observable $\chi_t$, the topological susceptibility. Assigning an
unphysically large value to the down mass allows to be more sensitive to the
non-perturbative effects behind the $m_u=0$ ambiguity. Preliminary results are
presented for four masses of clover fermions.


title: Fast and Energy-Efficient CNN Inference on IoT Devices

abstract:
  Convolutional Neural Networks (CNNs) exhibit remarkable performance in
various machine learning tasks. As sensor-equipped internet of things (IoT)
devices permeate into every aspect of modern life, it is increasingly important
to run CNN inference, a computationally intensive application, on resource
constrained devices. We present a technique for fast and energy-efficient CNN
inference on mobile SoC platforms, which are projected to be a major player in
the IoT space. We propose techniques for efficient parallelization of CNN
inference targeting mobile GPUs, and explore the underlying tradeoffs.
Experiments with running Squeezenet on three different mobile devices confirm
the effectiveness of our approach. For further study, please refer to the
project repository available on our GitHub page:
https://github.com/mtmd/Mobile_ConvNet


title: Rotational properties of hypermassive neutron stars from binary mergers

abstract:
  Determining the differential-rotation law of compact stellar objects produced
in binary neutron stars mergers or core-collapse supernovae is an old problem
in relativistic astrophysics. Addressing this problem is important because it
impacts directly on the maximum mass these objects can attain and hence on the
threshold to black-hole formation under realistic conditions. Using the results
from a large number of numerical simulations in full general relativity of
binary neutron star mergers described with various equations of state and
masses, we study the rotational properties of the resulting hypermassive
neutron stars. We find that the angular-velocity distribution shows only a
modest dependence on the equation of state, thus exhibiting the traits of
"quasi-universality" found in other aspects of compact stars, both isolated and
in binary systems. The distributions are characterized by an almost uniformly
rotating core and a "disk". Such a configuration is significantly different
from the $j-{\rm constant}$ differential-rotation law that is commonly adopted
in equilibrium models of differentially rotating stars. Furthermore, the
rest-mass contained in such a disk can be quite large, ranging from $\simeq
0.03\,M_{\odot}$ in the case of high-mass binaries with stiff equations of
state, up to $\simeq 0.2\,M_{\odot}$ for low-mass binaries with soft equations
of state. We comment on the astrophysical implications of our findings and on
the long-term evolutionary scenarios that can be conjectured on the basis of
our simulations.


title:
Dramatic change of photoexcited quasiparticle relaxation dynamics across
  Yb valence state transition in YbInCu$_4$

abstract:
  YbInCu$_4$ undergoes a first order structural phase transition near $T_v$=40
K associated with an abrupt change of Yb valence state. We perform ultrafast
pump-probe measurement on YbInCu$_4$ and find that the expected heavy fermion
properties arising from the \emph{c-f} hybridization exist only in a limited
temperature range above $T_v$. Below $T_v$, the compound behaves like a normal
metal though a prominent hybridization energy gap is still present in infrared
measurement. We elaborate that those seemingly controversial phenomena could be
well explained by assuming that the Fermi level suddenly shifts up and becomes
far away from the flat \emph{f}-electron band as well as the indirect
hybridization energy gap in the mixed valence state below $T_v$.


title: Linear and planar molecules formed by coupled P donors in silicon

abstract:
  Using the effective mass theory and the multi-valley envelope function
representation, we have developed a theoretical framework for computing the
single-electron electronic structure of several phosphorus donors interacting
in an arbitrary geometrical configuration in silicon taking into account the
valley-orbit coupling. The methodology is applied to three coupled phosphorus
donors, arranged in a linear chain and in a triangle, and to six donors
arranged in a regular hexagon. The results of the simulations evidence that the
valley composition of the single-electron states strongly depends on the
geometry of the dopant molecule and its orientation relative to the
crystallographic axes of silicon. The electron binding energy of the triatomic
linear molecules is larger than that of the diatomic molecule oriented along
the same crystallographic axis, but the energy gap between the ground state and
the first excited state is not significantly different for internuclear
distances from 1.5 to 6.6 nm. Three donor atoms arranged in a triangle geometry
have larger binding energies than a triatomic linear chain of dopants with the
same internuclear distances. The planar donor molecules are characterized by a
strong polarization in favor of the valleys oriented perpendicular to the plane
of the molecule. The polarization increases with number of atoms forming the
planar molecule.


title:
Importance and effectiveness of representing the shapes of Cosserat rods
  and framed curves as paths in the special Euclidean algebra

abstract:
  We discuss how the shape of a special Cosserat rod can be represented as a
path in the special Euclidean algebra. By shape we mean all those geometric
features that are invariant under isometries of the three-dimensional ambient
space. The representation of the shape as a path in the special Euclidean
algebra is intrinsic to the description of the mechanical properties of a rod,
since it is given directly in terms of the strain fields that stimulate the
elastic response of special Cosserat rods. Moreover, such a representation
leads naturally to discretization schemes that avoid the need for the expensive
reconstruction of the strains from the discretized placement and for
interpolation procedures which introduce some arbitrariness in popular
numerical schemes. Given the shape of a rod and the positioning of one of its
cross sections, the full placement in the ambient space can be uniquely
reconstructed and described by means of a base curve endowed with a material
frame. By viewing a geometric curve as a rod with degenerate point-like cross
sections, we highlight the essential difference between rods and framed curves,
and clarify why the family of relatively parallel adapted frames is not
suitable for describing the mechanics of rods but is the appropriate tool for
dealing with the geometry of curves.


title: Exploiting Web Images for Dataset Construction: A Domain Robust Approach

abstract:
  Labelled image datasets have played a critical role in high-level image
understanding. However, the process of manual labelling is both time-consuming
and labor intensive. To reduce the cost of manual labelling, there has been
increased research interest in automatically constructing image datasets by
exploiting web images. Datasets constructed by existing methods tend to have a
weak domain adaptation ability, which is known as the "dataset bias problem".
To address this issue, we present a novel image dataset construction framework
that can be generalized well to unseen target domains. Specifically, the given
queries are first expanded by searching the Google Books Ngrams Corpus to
obtain a rich semantic description, from which the visually non-salient and
less relevant expansions are filtered out. By treating each selected expansion
as a "bag" and the retrieved images as "instances", image selection can be
formulated as a multi-instance learning problem with constrained positive bags.
We propose to solve the employed problems by the cutting-plane and
concave-convex procedure (CCCP) algorithm. By using this approach, images from
different distributions can be kept while noisy images are filtered out. To
verify the effectiveness of our proposed approach, we build an image dataset
with 20 categories. Extensive experiments on image classification,
cross-dataset generalization, diversity comparison and object detection
demonstrate the domain robustness of our dataset.


title:
The reversibility and first-order nature of liquid-liquid transition in
  a molecular liquid

abstract:
  Liquid-liquid transition is an intriguing phenomenon in which a liquid
transforms into another liquid via the first-order transition. For molecular
liquids, however, it always takes place in a supercooled liquid state
metastable against crystallization, which has led to a number of serious
debates concerning its origin: liquid-liquid transition vs. unusual
nano-crystal formation. Thus, there have so far been no single example free
from such debates. Here we show the first firm experimental evidence that the
transition is truly liquid-liquid transition and not nano-crystallization for a
molecular liquid, triphenyl phosphite. We kinetically isolate the reverse
liquid-liquid transition from glass transition and crystallization with an
extremely high heating rate of flash differential scanning calorimetry, and
prove the reversibility and first-order nature of liquid-liquid transition. Our
finding not only deepens our physical understanding of liquid-liquid transition
but also will initiate a new phase of its research from both fundamental and
applications viewpoints.

categories: cond-mat.soft cond-mat.dis-nn cond-mat.mtrl-sci cond-mat.stat-mech


title: Optical gears in a nanophotonic directional coupler

abstract:
  Gears are rotating machines, meshing with each other by teeth to transmit
torque. Interestingly, the rotating directions of two meshing gears are
opposite, clockwise and counterclockwise. Although this opposite handedness
motion has been widely investigated in machinery science, the analogue behavior
of photons remains undiscovered. Here, we present a simple nanophotonic
directional coupler structure which can generate two meshing gears of angular
momentum (AM) of light, optical gears. Due to the abrupt phase shift effect and
birefringence effect, the AM states of photons vary with the propagation
distance in two adjacent waveguides of the coupler. Thus, by the choice of
coupling length, it is able to obtain two light beams with opposite handedness
of AM, confirming the appearance of optical gears. The full control in the
handedness of output beams is achieved via tuning the relative phase between
two orthogonal modes at the input ports. Optical gears thus offer the
possibility of exploring light-matter interactions in nanoscale, opening up new
avenues in fields of integrated quantum computing and nanoscale bio-sensing of
chiral molecules.


title: Weak Quasielastic Production of Hyperons

abstract:
  We present the results for antineutrino induced quasielastic hyperon
production from nucleon and nuclear targets \cite{Alam:2014bya,Singh:2006xp}.
The inputs are the nucleon-hyperon(N--Y) transition form factors determined
from the analysis of neutrino-nucleon scattering and semileptonic decays of
neutron and hyperons using SU(3) symmetry. The calculations for the nuclear
targets are done in local density approximation. The nuclear medium
effects(NME) like Fermi motion, Pauli blocking and final state interaction(FSI)
effects due to hyperon-nucleon scattering have been taken into account. The
hyperons giving rise to pions through weak decays also contribute to the weak
pion production in addition to the $\Delta$ excitation mechanism which
dominates in the energy region of $<$ 0.7 GeV. We also present the results of
longitudinal and perpendicular components of polarization of final hyperon
\cite{Akbar:2016awk}. These measurements in the future accelerator experiments
with antineutrinos may give some information on axial vector and pseudoscalar
form factors in the strangeness sector.


title:
Surface Brightness Correction for Compact Extended Sources Observed by
  the AKARI Far-Infrared Surveyor (FIS) in the Slow-Scan Mode

abstract:
  We present a general surface brightness correction method for compact
extended sources imaged in the slow-scan pointed observation mode of the
Far-Infrared Surveyor (FIS) aboard the AKARI Infrared Astronomical Satellite.
Our method recovers correct surface brightness distribution maps by re-scaling
archived raw FIS maps using the surface-brightness-dependent inverse FIS
response function. The flux of a target source is then automatically corrected
for as the simple sum of surface brightnesses within the adopted contour
encircling the perimeter of the target (i.e., contour photometry). This
correction method is contrasted to the previous aperture photometry method for
point sources, which directly corrects for the target flux with a
flux-dependent scaling law. The new surface brightness correction scheme is
applicable to objects of any shape from unresolved point sources to resolved
extended objects, as long as the target is not deemed diffuse, i.e., the total
extent of the target source does not exceed too much more than a single FIS
scan width of 10 arcmin. The new correction method takes advantage of the
well-defined shape (i.e., the scale invariance) of the point-spread function,
which enables us to adopt a power-law FIS response function. We analyze the
point-source photometric calibrator data using the FIS AKARI Slow-scan Tool
(FAST) and constrained the parameters of the adopted power-law FIS response
function. We conclude that the photometric accuracy of the new correction
method is better than 10% error based on comparisons with the expected fluxes
of the photometric calibrators and that resulting fluxes without the present
correction method can lead up to 230% overestimates or down to 50%
underestimates.


title:
Optimal Learning for Stochastic Optimization with Nonlinear Parametric
  Belief Models

abstract:
  We consider the problem of estimating the expected value of information (the
knowledge gradient) for Bayesian learning problems where the belief model is
nonlinear in the parameters. Our goal is to maximize some metric, while
simultaneously learning the unknown parameters of the nonlinear belief model,
by guiding a sequential experimentation process which is expensive. We overcome
the problem of computing the expected value of an experiment, which is
computationally intractable, by using a sampled approximation, which helps to
guide experiments but does not provide an accurate estimate of the unknown
parameters. We then introduce a resampling process which allows the sampled
model to adapt to new information, exploiting past experiments. We show
theoretically that the method converges asymptotically to the true parameters,
while simultaneously maximizing our metric. We show empirically that the
process exhibits rapid convergence, yielding good results with a very small
number of experiments.


title:
Evidence from stable isotopes and Be-10 for solar system formation
  triggered by a low-mass supernova

abstract:
  About 4.6 billion years ago, some event disturbed a cloud of gas and dust,
triggering the gravitational collapse that led to the formation of the solar
system. A core-collapse supernova, whose shock wave is capable of compressing
such a cloud, is an obvious candidate for the initiating event. This hypothesis
can be tested because supernovae also produce telltale patterns of short-lived
radionuclides, which would be preserved today as isotopic anomalies. Previous
studies of the forensic evidence have been inconclusive, finding a pattern of
isotopes differing from that produced in conventional supernova models. Here we
argue that these difficulties either do not arise or are mitigated if the
initiating supernova was a special type, low in mass and explosion energy. Key
to our conclusion is the demonstration that short-lived Be-10 can be readily
synthesized in such supernovae by neutrino interactions, while anomalies in
stable isotopes are suppressed.


title: Will My Tests Tell Me If I Break This Code?

abstract:
  Automated tests play an important role in software evolution because they can
rapidly detect faults introduced during changes. In practice, code-coverage
metrics are often used as criteria to evaluate the effectiveness of test suites
with focus on regression faults. However, code coverage only expresses which
portion of a system has been executed by tests, but not how effective the tests
actually are in detecting regression faults. Our goal was to evaluate the
validity of code coverage as a measure for test effectiveness. To do so, we
conducted an empirical study in which we applied an extreme mutation testing
approach to analyze the tests of open-source projects written in Java. We
assessed the ratio of pseudo-tested methods (those tested in a way such that
faults would not be detected) to all covered methods and judged their impact on
the software project. The results show that the ratio of pseudo-tested methods
is acceptable for unit tests but not for system tests (that execute large
portions of the whole system). Therefore, we conclude that the coverage metric
is only a valid effectiveness indicator for unit tests.


title: Distance verification for classical and quantum LDPC codes

abstract:
  The techniques of distance verification known for general linear codes are
re-applied to quantum stabilizer codes. Then distance verification is addressed
for classical and quantum LDPC codes. New complexity bounds for distance
verification with provable performance are derived using the average weight
spectra of the ensembles of LDPC codes. These bounds are expressed in terms of
the erasure-correcting capacity of the corresponding ensemble. We also present
a new irreducible-cluster technique that can be applied to any LDPC code and
takes advantage of parity-checks' sparsity for both classical and quantum LDPC
codes. This technique reduces complexity exponents of all existing
deterministic techniques designed for generic stabilizer codes with small
relative distances, which also include all known families of quantum LDPC
codes.