title: A note on $G$-intersecting families

abstract:
  Consider a graph $G$ and a $k$-uniform hypergraph $\mathcal{H}$ on common
vertex set $[n]$. We say that $\mathcal{H}$ is $G$-intersecting if for every
pair of edges in $X,Y \in \mathcal{H}$ there are vertices $x \in X$ and $y \in
Y$ such that $x = y$ or $x$ and $y$ are joined by an edge in $G$. This notion
was introduced by Bohman, Frieze, Ruszink\'o and Thoma who proved a natural
generalization of the Erd\H{o}s-Ko-Rado Theorem for $G$-intersecting
$k$-uniform hypergraphs for $G$ sparse and $k = O( n^{1/4} )$. In this note, we
extend this result to $k = O\left( \sqrt{n} \right)$.


title:
More Powerful Multiple Testing in Randomized Experiments with
  Non-Compliance

abstract:
  Two common concerns raised in analyses of randomized experiments are (i)
appropriately handling issues of non-compliance, and (ii) appropriately
adjusting for multiple tests (e.g., on multiple outcomes or subgroups).
Although simple intention-to-treat (ITT) and Bonferroni methods are valid in
terms of type I error, they can each lead to a substantial loss of power; when
employing both simultaneously, the total loss may be severe. Alternatives exist
to address each concern. Here we propose an analysis method for experiments
involving both features that merges posterior predictive $p$-values for
complier causal effects with randomization-based multiple comparisons
adjustments; the results are valid familywise tests that are doubly
advantageous: more powerful than both those based on standard ITT statistics
and those using traditional multiple comparison adjustments. The operating
characteristics and advantages of our method are demonstrated through a series
of simulated experiments and an analysis of the United States Job Training
Partnership Act (JTPA) Study, where our methods lead to different conclusions
regarding the significance of estimated JTPA effects.


title: How many random edges make a dense graph hamiltonian?

abstract:
  This paper investigates the number of random edges required to add to an
arbitrary dense graph in order to make the resulting graph hamiltonian with
high probability. Adding $\Theta(n)$ random edges is both necessary and
sufficient to ensure this for all such dense graphs. If, however, the original
graph contains no large independent set, then many fewer random edges are
required. We prove a similar result for directed graphs.


title: Optimal Estimation of Co-heritability in High-dimensional Linear Models

abstract:
  Co-heritability is an important concept that characterizes the genetic
associations within pairs of quantitative traits. There has been significant
recent interest in estimating the co-heritability based on data from the
genome-wide association studies (GWAS). This paper introduces two measures of
co-heritability in the high-dimensional linear model framework, including the
inner product of the two regression vectors and a normalized inner product by
their lengths. Functional de-biased estimators (FDEs) are developed to estimate
these two co-heritability measures. In addition, estimators of quadratic
functionals of the regression vectors are proposed. Both theoretical and
numerical properties of the estimators are investigated. In particular, minimax
rates of convergence are established and the proposed estimators of the inner
product, the quadratic functionals and the normalized inner product are shown
to be rate-optimal. Simulation results show that the FDEs significantly
outperform the naive plug-in estimates. The FDEs are also applied to analyze a
yeast segregant data set with multiple traits to estimate heritability and
co-heritability among the traits.


title:
The Intermediate Luminosity Optical Transient SN 2010da: The Progenitor,
  Eruption and Aftermath of a Peculiar Supergiant High-mass X-ray Binary

abstract:
  We present optical spectroscopy, ultraviolet to infrared imaging and X-ray
observations of the intermediate luminosity optical transient (ILOT) SN 2010da
in NGC 300 (d=1.86 Mpc) spanning from -6 to +6 years relative to the time of
outburst in 2010. Based on the light curve and multi-epoch SEDs of SN 2010da,
we conclude that the progenitor of SN 2010da is a ~10-12 Msol yellow supergiant
possibly transitioning into a blue loop phase. During outburst, SN 2010da had a
peak absolute magnitude of M<-10.4 mag, dimmer than other ILOTs and supernova
impostors. We detect multi-component hydrogen Balmer, Paschen, and Ca II
emission lines in our high-resolution spectra, which indicate a dusty and
complex circumstellar environment. Since the 2010 eruption, the star has
brightened by a factor of ~5 and remains highly variable in the optical.
Furthermore, we detect SN 2010da in archival Swift and Chandra observations as
an ultraluminous X-ray source (L~6x10^{39} erg/s). We additionally attribute He
II 4686 Angstrom and coronal Fe emission lines in addition to a steady X-ray
luminosity of ~10^{37} erg/s to the presence of a compact companion.


title: Adaptive ADMM with Spectral Penalty Parameter Selection

abstract:
  The alternating direction method of multipliers (ADMM) is a versatile tool
for solving a wide range of constrained optimization problems, with
differentiable or non-differentiable objective functions. Unfortunately, its
performance is highly sensitive to a penalty parameter, which makes ADMM often
unreliable and hard to automate for a non-expert user. We tackle this weakness
of ADMM by proposing a method to adaptively tune the penalty parameters to
achieve fast convergence. The resulting adaptive ADMM (AADMM) algorithm,
inspired by the successful Barzilai-Borwein spectral method for gradient
descent, yields fast convergence and relative insensitivity to the initial
stepsize and problem scaling.


title:
Network approach integrates 3D structural and sequence data to improve
  protein structural comparison

abstract:
  Initial protein structural comparisons were sequence-based. Since amino acids
that are distant in the sequence can be close in the 3-dimensional (3D)
structure, 3D contact approaches can complement sequence approaches.
Traditional 3D contact approaches study 3D structures directly. Instead, 3D
structures can be modeled as protein structure networks (PSNs). Then, network
approaches can compare proteins by comparing their PSNs. Network approaches may
improve upon traditional 3D contact approaches. We cannot use existing PSN
approaches to test this, because: 1) They rely on naive measures of network
topology. 2) They are not robust to PSN size. They cannot integrate 3) multiple
PSN measures or 4) PSN data with sequence data, although this could help
because the different data types capture complementary biological knowledge. We
address these limitations by: 1) exploiting well-established graphlet measures
via a new network approach, 2) introducing normalized graphlet measures to
remove the bias of PSN size, 3) allowing for integrating multiple PSN measures,
and 4) using ordered graphlets to combine the complementary PSN data and
sequence data. We compare both synthetic networks and real-world PSNs more
accurately and faster than existing network, 3D contact, or sequence
approaches. Our approach finds PSN patterns that may be biochemically
interesting.


title:
Shear Viscosity to Entropy Density Ratio in Higher Derivative Gravity
  with Momentum Dissipation

abstract:
  We investigate $\eta/s$ in linear scalar fields modified Gauss-Bonnet theory
that breaks translation invariance. We first calculate $\eta/s$ both
analytically and numerically and show its relationship with temperature in
log-log plot. Our results show that $\eta/s\sim T^2$ at low temperatures. The
causality is also considered in this work. We then find that causality
violation still happens in the presence of the linear scalar field and we
suggest there is a Gauss-Bonnet coupling dependent lower limit for the
effective mass of the graviton. If the effective mass of the graviton is big
enough, then there will be no causality violation and hence no constraints for
the Gauss-Bonnet coupling.


title: A Massive Data Framework for M-Estimators with Cubic-Rate

abstract:
  The divide and conquer method is a common strategy for handling massive data.
In this article, we study the divide and conquer method for cubic-rate
estimators under the massive data framework. We develop a general theory for
establishing the asymptotic distribution of the aggregated M-estimators using a
simple average. Under certain condition on the growing rate of the number of
subgroups, the resulting aggregated estimators are shown to have faster
convergence rate and asymptotic normal distribution, which are more tractable
in both computation and inference than the original M-estimators based on
pooled data. Our theory applies to a wide class of M-estimators with cube root
convergence rate, including the location estimator, maximum score estimator and
value search estimator. Empirical performance via simulations also validate our
theoretical findings.


title:
New result on Chern conjecture for minimal hypersurfaces and its
  application

abstract:
  We verify that if $M$ is a compact minimal hypersurface in $\mathbb{S}^{n+1}$
whose squared length of the second fundamental form satisfying $0\leq
|A|^2-n\leq\frac{n}{22}$, then $|A|^2\equiv n$ and $M$ is a Clifford torus.
Moreover, we prove that if $M$ is a complete self-shrinker with polynomial
volume growth in $\mathbb{R}^{n+1}$ whose equation is given by (\ref{selfshr}),
and if the squared length of the second fundamental form of $M$ satisfies
$0\leq|A|^2-1\leq\frac{1}{21}$, then $|A|^2\equiv1$ and $M$ is a round sphere
or a cylinder. Our results improve the rigidity theorems due to Q. Ding and Y.
L. Xin \cite{DX1,DX2}.


title: Dense CNN Learning with Equivalent Mappings

abstract:
  Large receptive field and dense prediction are both important for achieving
high accuracy in pixel labeling tasks such as semantic segmentation. These two
properties, however, contradict with each other. A pooling layer (with stride
2) quadruples the receptive field size but reduces the number of predictions to
25\%. Some existing methods lead to dense predictions using computations that
are not equivalent to the original model. In this paper, we propose the
equivalent convolution (eConv) and equivalent pooling (ePool) layers, leading
to predictions that are both dense and equivalent to the baseline CNN model.
Dense prediction models learned using eConv and ePool can transfer the baseline
CNN's parameters as a starting point, and can inverse transfer the learned
parameters in a dense model back to the original one, which has both fast
testing speed and high accuracy. The proposed eConv and ePool layers have
achieved higher accuracy than baseline CNN in various tasks, including semantic
segmentation, object localization, image categorization and apparent age
estimation, not only in those tasks requiring dense pixel labeling.


title:
Interaction Screening: Efficient and Sample-Optimal Learning of Ising
  Models

abstract:
  We consider the problem of learning the underlying graph of an unknown Ising
model on p spins from a collection of i.i.d. samples generated from the model.
We suggest a new estimator that is computationally efficient and requires a
number of samples that is near-optimal with respect to previously established
information-theoretic lower-bound. Our statistical estimator has a physical
interpretation in terms of "interaction screening". The estimator is consistent
and is efficiently implemented using convex optimization. We prove that with
appropriate regularization, the estimator recovers the underlying graph using a
number of samples that is logarithmic in the system size p and exponential in
the maximum coupling-intensity and maximum node-degree.

categories: cs.LG cond-mat.stat-mech cs.IT math.IT math.ST stat.ML stat.TH


title:
Very Long Baseline Interferometry Experiment on Giant Radio Pulses of
  Crab Pulsar toward Fast Radio Burst Detection

abstract:
  We report on a very long baseline interferometry (VLBI) experiment on giant
radio pulses (GPs) from the Crab pulsar in the radio 1.4 to 1.7 GHz range to
demonstrate a VLBI technique for searching for fast radio bursts (FRBs). We
carried out the experiment on 26 July 2014 using the Kashima 34 m and Usuda 64
m radio telescopes of the Japanese VLBI Network (JVN) with a baseline of about
200 km. During the approximately 1 h observation, we could detect 35 GPs by
high-time-resolution VLBI. Moreover, we determined the dispersion measure (DM)
to be 56.7585 +/- 0.0025 on the basis of the mean DM of the 35 GPs detected by
VLBI. We confirmed that the sensitivity of a detection of GPs using our
technique is superior to that of a single-dish mode detection using the same
telescope.


title:
Convergence guarantees for kernel-based quadrature rules in misspecified
  settings

abstract:
  Kernel-based quadrature rules are becoming important in machine learning and
statistics, as they achieve super-$\sqrt{n}$ convergence rates in numerical
integration, and thus provide alternatives to Monte Carlo integration in
challenging settings where integrands are expensive to evaluate or where
integrands are high dimensional. These rules are based on the assumption that
the integrand has a certain degree of smoothness, which is expressed as that
the integrand belongs to a certain reproducing kernel Hilbert space (RKHS).
However, this assumption can be violated in practice (e.g., when the integrand
is a black box function), and no general theory has been established for the
convergence of kernel quadratures in such misspecified settings. Our
contribution is in proving that kernel quadratures can be consistent even when
the integrand does not belong to the assumed RKHS, i.e., when the integrand is
less smooth than assumed. Specifically, we derive convergence rates that depend
on the (unknown) lesser smoothness of the integrand, where the degree of
smoothness is expressed via powers of RKHSs or via Sobolev spaces.


title:
An alternative proof of lower bounds for the first eigenvalue on
  manifolds

abstract:
  Recently, Andrews and Clutterbuck [AC13] gave a new proof of the optimal
lower eigenvalue bound on manifolds via modulus of continuity for solutions of
the heat equation. In this short note, we give an alternative proof of Theorem
2 in [AC13]. More precisely, following Ni's method ([Ni13, Section 6]) we give
an elliptic proof of this theorem.


title:
Exploring the evolution of Reionisation using a wavelet transform and
  the light cone effect

abstract:
  The Cosmic Dawn and Epoch of Reionisation, during which collapsed structures
produce the first ionising photons and proceed to reionise the intergalactic
medium, span a large range in redshift (z~30-6) and time (t_{age} ~
0.1-1.0~Gyr). Exploration of these epochs using the redshifted 21~cm emission
line from neutral hydrogen is currently limited to statistical detection and
estimation metrics (e.g., the power spectrum) due to the weakness of the
signal. Brightness temperature fluctuations in the line-of-sight (LOS)
dimension are probed by observing the emission line at different frequencies,
and their structure is used as a primary discriminant between the cosmological
signal and contaminating foreground extragalactic and Galactic continuum
emission. Evolution of the signal over the observing bandwidth leads to the
`line cone effect' whereby the HI structures at the start and end of the
observing band are not statistically consistent, yielding a biased estimate of
the signal power, and potential reduction in signal detectability. We implement
a wavelet transform to wide bandwidth radio interferometry experiments to probe
the local statistical properties of the signal. We show that use of the wavelet
transform yields estimates with improved estimation performance, compared with
the standard Fourier Transform over a fixed bandwidth. With the suite of
current and future large bandwidth reionisation experiments, such as with the
300~MHz instantaneous bandwidth of the Square Kilometre Array, a transform that
retains local information will be important.


title:
Characterizing micro-macro transitions with an atomic-vapor-based linear
  optical amplifier

abstract:
  Fundamentally, the dynamics of micro-macro transitions is instrumental to
understanding the process of quantum-to-classical transitions; technologically,
it can also facilitate the detection of the microscopic signals in quantum
experiments via convenient detectors. Here, we demonstrate a scheme to
characterize micro-macro transitions based on a four-wave mixing linear optical
amplification process in a hot rubidium vapor. The linear optical amplifier
provides a large optical gain of $10^7$ for injected single-photon-level
pulses, enabling photon-number-resolving detection by average via
non-single-photon counting detectors with a large dynamic range. The scheme
exhibits strong dispersion which is sensitive to the input's change at the
single-photon level, resulting in the group-velocity delay time scaling with
$1/\sqrt{N}$, where $N$ is the average input photon number. The output probe
and conjugate modes have different coefficients of this $1/\sqrt{N}$ scaling,
indicating the coefficient can serve as an efficient parameter to characterize
the specified micro-macro transitions. The demonstrated results are generally
applicable for quantum detection and optical signal processing in light-atom
interfaces. Furthermore, the present system is suitable for the study of
relevant time-resolved dynamics of the quantum-to-classical transitions.


title: Refinements of the holonomic approximation lemma

abstract:
  The holonomic approximation lemma of Eliashberg and Mishachev is a powerful
tool in the philosophy of the $h-$principle. By carefully keeping track of the
quantitative geometry behind the holonomic approximation process, we establish
several refinements of this lemma. Gromov's idea from convex integration of
working one pure partial derivative at a time is central to the discussion. We
give applications of our results to flexible symplectic and contact topology.


title: The simplification of singularities of Lagrangian and Legendrian fronts

abstract:
  We establish a full $h-$principle ($C^0-$close, relative, parametric) for the
simplification of singularities of Lagrangian and Legendrian fronts. More
precisely, we prove that if there is no homotopy theoretic obstruction to
simplifying the singularities of tangency of a Lagrangian or Legendrian
submanifold with respect to an ambient foliation by Lagrangian or Legendrian
leaves, then the simplification can be achieved by means of a Hamiltonian
isotopy.


title:
Diagnosing editorial strategies of Chilean media on Twitter using an
  automatic news classifier

abstract:
  In Chile, does not exist an independent entity that publishes quantitative or
qualitative surveys to understand the traditional media environment and its
adaptation on the Social Web. Nowadays, Chilean newsreaders are increasingly
using social web platforms as their primary source of information, among which
Twitter plays a central role. Historical media and pure players are developing
different strategies to increase their audience and influence on this platform.
In this article, we propose a methodology based on data mining techniques to
provide a first level of analysis of the new Chilean media environment. We use
a crawling technique to mine news streams of 37 different Chilean media
actively presents on Twitter and propose several indicators to compare them. We
analyze their volumes of production, their potential audience, and using NLP
techniques, we explore the content of their production: their editorial line
and their geographic coverage.


title:
IGRINS spectroscopy of Class I sources: IRAS 03445+3242 and IRAS
  04239+2436

abstract:
  We have detected molecular and atomic line emission from the hot and warm
disks of two Class I sources, IRAS 03445+3242 and IRAS 04239+2436 using the
high resolution Immersion GRating INfrared Spectrograph (IGRINS). CO overtone
band transitions and near-IR lines of Na I and Ca I, all in emission, trace the
hot inner disk while CO rovibrational absorption spectra of the first overtone
transition trace the warm gas within the inner few AU of the disk. The
emission-line profiles for both sources show evidence for Keplerian disks. A
thin Keplerian disk with power-law temperature and column density profiles with
a projected rotational velocity of $\sim$60--75 km s$^{-1}$ and a gas
temperature of $\sim$3500 K at the innermost annulus can reproduce the CO
overtone band emission. Na I and Ca I emission lines also arise from this disk,
but they show complicated line features possibly affected by photospheric
absorption lines. Multi-epoch observations show asymmetric variations of the
line profiles on one-year (CO overtone bandhead and atomic lines for IRAS
03445+3242) or on one-day (atomic lines for IRAS 04239+2436) time scales,
implying non-axisymmetric features in disks. The narrow CO rovibrational
absorption spectra ($v$=0$\rightarrow$2) indicate that both warm ($>$ 150 K)
and cold ($\sim$20--30 K) CO gas are present along the line of sight to the
inner disk. This study demonstrates the power of IGRINS as a tool for studies
of the sub-AU scale hot and AU-scale warm protoplanetary disks with its
simultaneous coverage of the full H and K bands with high spectral resolution
($R$= 45,000) allowing many aspects of the sources to be investigated at once.


title: Measuring Neural Net Robustness with Constraints

abstract:
  Despite having high accuracy, neural nets have been shown to be susceptible
to adversarial examples, where a small perturbation to an input can cause it to
become mislabeled. We propose metrics for measuring the robustness of a neural
net and devise a novel algorithm for approximating these metrics based on an
encoding of robustness as a linear program. We show how our metrics can be used
to evaluate the robustness of deep neural nets with experiments on the MNIST
and CIFAR-10 datasets. Our algorithm generates more informative estimates of
robustness metrics compared to estimates based on existing algorithms.
Furthermore, we show how existing approaches to improving robustness "overfit"
to adversarial examples generated using a specific algorithm. Finally, we show
that our techniques can be used to additionally improve neural net robustness
both according to the metrics that we propose, but also according to previously
proposed metrics.


title: Sarkozy's theorem in function fields

abstract:
  S\'ark\"ozy proved that dense sets of integers contain two elements differing
by a $k$th power. The bounds in quantitative versions of this theorem are
rather weak compared to what is expected. We prove a version of S\'ark\"ozy's
theorem for polynomials over $\mathbb{F}_q$ with polynomial dependencies in the
parameters.
  More precisely, let $P_{q,n}$ be the space of polynomials over $\mathbb{F}_q$
of degree $< n$ in an indeterminate $T$. Let $k \geq 2$ be an integer and let
$q$ be a prime power. Set $c(k,q) := (2 k^2 D_q(k)^2\log q)^{-1}$, where
$D_q(k)$ is the sum of the digits of $k$ in base $q$. If $A \subset P_{q,n}$ is
a set with $|A| > 2q^{(1 - c(k,q))n}$, then $A$ contains distinct polynomials
$p(T), p'(T)$ such that $p(T) - p'(T) = b(T)^k$ for some $b \in
\mathbb{F}_q[T]$.


title: Trajectory probability hypothesis density filter

abstract:
  This paper presents the probability hypothesis density (PHD) filter for sets
of trajectories: the trajectory probability density (TPHD) filter. The TPHD
filter is capable of estimating trajectories in a principled way without
requiring to evaluate all measurement-to-target association hypotheses. The
TPHD filter is based on recursively obtaining the best Poisson approximation to
the multitrajectory filtering density in the sense of minimising the
Kullback-Leibler divergence. We also propose a Gaussian mixture implementation
of the TPHD recursion. Finally, we include simulation results to show the
performance of the proposed algorithm.


title:
Strong Optical and UV Intermediate-Width Emission Lines in the Quasar
  SDSS J232444.80-094600.3: Dust-Free and Intermediate-Density Gas at the Skin
  of Dusty Torus ?

abstract:
  Emission lines from the broad emission line region (BELR) and the narrow
emission line region (NELR) of active galactic nuclei (AGNs) are extensively
studied. However, between these two regions emission lines are rarely detected.
We present a detailed analysis of a quasar SDSS J232444.80-094600.3 (SDSS
J2324$-$0946), which is remarkable for its strong intermediate-width emission
lines (IELs) with FWHM $\approx$ 1800 \kmps. The IEL component is presented in
different emission lines, including the permitted lines \lya\ $\lambda$1216,
\civ\ $\lambda$1549, semiforbidden line \ciii\ $\lambda$1909, and forbidden
lines \oiii\ $\lambda\lambda$4959, 5007. With the aid of photo-ionization
models, we found that the IELs are produced by gas with a hydrogen density of
$n_{\rm H} \sim 10^{6.2}-10^{6.3}~\rm cm^{-3}$, a distance to the central
ionizing source of $R \sim 35-50$ pc, a covering factor of CF $\sim$ 6\%, and a
dust-to-gas ratio of $\leq 4\%$ times of SMC. We suggest that the strong IELs
of this quasar are produced by nearly dust-free and intermediate-density gas
located at the skin of the dusty torus. Such strong IELs, served as a useful
diagnose, can provide an avenue to study the properties of gas between the BELR
and the NELR.


title:
Efficient and accurate extraction of in vivo calcium signals from
  microendoscopic video data

abstract:
  In vivo calcium imaging through microscopes has enabled deep brain imaging of
previously inaccessible neuronal populations within the brains of freely moving
subjects. However, microendoscopic data suffer from high levels of background
fluorescence as well as an increased potential for overlapping neuronal
signals. Previous methods fail in identifying neurons and demixing their
temporal activity because the cellular signals are often submerged in the large
fluctuating background. Here we develop an efficient method to extract cellular
signals with minimal influence from the background. We model the background
with two realistic components: (1) one models the constant baseline and slow
trends of each pixel, and (2) the other models the fast fluctuations from
out-of-focus signals and is therefore constrained to have low spatial-frequency
structure. This decomposition avoids cellular signals being absorbed into the
background term. After subtracting the background approximated with this model,
we use Constrained Nonnegative Matrix Factorization (CNMF, Pnevmatikakis et al.
(2016)) to better demix neural signals and get their denoised and deconvolved
temporal activity. We validate our method on simulated and experimental data,
where it shows fast, reliable, and high quality signal extraction under a wide
variety of imaging parameters.


title: A random link via bridge position is hyperbolic

abstract:
  We show that a random link defined by random bridge splitting is hyperbolic
with asymptotic probability 1.


title:
Classifying discourse in a CSCL platform to evaluate correlations with
  Teacher Participation and Progress

abstract:
  In Computer-Supported learning, monitoring and engaging a group of learners
is a complex task for teachers, especially when learners are working
collaboratively: Are my students motivated? What kind of progress are they
making? Should I intervene? Is my communication and the didactic design adapted
to my students? Our hypothesis is that the analysis of natural language
interactions between students, and between students and teachers, provide very
valuable information and could be used to produce qualitative indicators to
help teachers' decisions. We develop an automatic approach in three steps (1)
to explore the discursive functions of messages in a CSCL platform, (2) to
classify the messages automatically and (3) to evaluate correlations between
discursive attitudes and other variables linked to the learning activity.
Results tend to show that some types of discourse are correlated with a notion
of Progress on the learning activities and the importance of emotive
participation from the Teacher.


title: On the numerical radius of a quaternionic normal operator

abstract:
  We prove that for a right linear bounded normal operator on a quaternionic
Hilbert space (quaternionic bounded normal operator) the norm and the numerical
radius are equal. As a consequence of this result we give a new proof of the
known fact that a non zero quaternionic compact normal operator has a non zero
right eigenvalue. Using this we give a new proof of the spectral theorem for
quaternionic compact normal operators.. Finally, we show that every
quaternionic compact operator is norm attaining and prove the Lindenstrauss
theorem on norm attaining operators, namely, the set of all norm attaining
quaternionic operators is norm dense in the space of all bounded quaternionic
operators defined between two quaternionic Hilbert spaces.


title:
Learning a Metric Embedding for Face Recognition using the Multibatch
  Method

abstract:
  This work is motivated by the engineering task of achieving a near
state-of-the-art face recognition on a minimal computing budget running on an
embedded system. Our main technical contribution centers around a novel
training method, called Multibatch, for similarity learning, i.e., for the task
of generating an invariant "face signature" through training pairs of "same"
and "not-same" face images. The Multibatch method first generates signatures
for a mini-batch of $k$ face images and then constructs an unbiased estimate of
the full gradient by relying on all $k^2-k$ pairs from the mini-batch. We prove
that the variance of the Multibatch estimator is bounded by $O(1/k^2)$, under
some mild conditions. In contrast, the standard gradient estimator that relies
on random $k/2$ pairs has a variance of order $1/k$. The smaller variance of
the Multibatch estimator significantly speeds up the convergence rate of
stochastic gradient descent. Using the Multibatch method we train a deep
convolutional neural network that achieves an accuracy of $98.2\%$ on the LFW
benchmark, while its prediction runtime takes only $30$msec on a single ARM
Cortex A9 core. Furthermore, the entire training process took only 12 hours on
a single Titan X GPU.


title:
Constraining the Age and Distance of the Galactic Supernova Remnant
  G156.2+5.7 by H-alpha Expansion Measurements

abstract:
  We present deep H-alpha images of portions of the X-ray bright but optically
faint Galactic supernova remnant G156.2+5.7, revealing numerous and delicately
thin nonradiative filaments which mark the location of the remnant's forward
shock. These new images show that these filaments have a complex structure not
visible on previous lower resolution optical images. By comparing H-alpha
images taken in 2004 at the McDonald Observatory and in 2015-2016 at the Kiso
Observatory, we set a stringent 1-sigma upper limit of expansion to be 0.06
arcsec/yr. This proper motion, combined with a shock speed of 500 km/s inferred
from X-ray spectral analyses, gives a distance of > 1.7 kpc. In addition, a
simple comparison of expansion indices of several SNRs allows us to infer the
age of the remnant to be a few 10,000 yr old. These estimates are more
straightforward and reliable than any other previous studies, and clearly rule
out a possibility that G156.2+5.7 is physically associated with part of the
Taurus-Auriga cloud and dust complex at a distance of 200-300 pc.


title: Matrix Completion has No Spurious Local Minimum

abstract:
  Matrix completion is a basic machine learning problem that has wide
applications, especially in collaborative filtering and recommender systems.
Simple non-convex optimization algorithms are popular and effective in
practice. Despite recent progress in proving various non-convex algorithms
converge from a good initial point, it remains unclear why random or arbitrary
initialization suffices in practice. We prove that the commonly used non-convex
objective function for \textit{positive semidefinite} matrix completion has no
spurious local minima --- all local minima must also be global. Therefore, many
popular optimization algorithms such as (stochastic) gradient descent can
provably solve positive semidefinite matrix completion with \textit{arbitrary}
initialization in polynomial time. The result can be generalized to the setting
when the observed entries contain noise. We believe that our main proof
strategy can be useful for understanding geometric properties of other
statistical problems involving partial or noisy observations.


title: LDPC Codes Based on the Space of Symmetric Matrices over Finite Fields

abstract:
  In this paper, we present a new method for explicitly constructing regular
low-density parity-check (LDPC) codes based on
$\mathbb{S}_{n}(\mathbb{F}_{q})$, the space of $n\times n$ symmetric matrices
over $\mathbb{F}_{q}$. Using this method, we obtain two classes of binary LDPC
codes, $\cal{C}(n,q)$ and $\cal{C}^{T}(n,q)$, both of which have grith $8$.
Then both the minimum distance and the stopping distance of each class are
investigated. It is shown that the minimum distance and the stopping distance
of $\cal{C}^{T}(n,q)$ are both $2q$. As for $\cal{C}(n,q)$, we determine the
minimum distance and the stopping distance for some special cases and obtain
the lower bounds for other cases.


title:
Improving the stimulated Raman adiabatic passage via dissipative quantum
  dynamics

abstract:
  We propose a method to improve the stimulated Raman adiabatic passage
(STIRAP) via dissipative quantum dynamics, taking into account the dephasing
effects. Fast and robust population transfer can be obtained with the scheme by
the designed pulses and detuning, even though the initial state of the system
is imperfect. With a concrete three-level system as an example, the influences
of the imperfect initial state, variations in the control parameters, and
various dissipation effects are discussed in detail. The numerical simulation
shows that the scheme is insensitive to moderate fluctuations of experimental
parameters and the relatively large dissipation effects of the excited state.
Furthermore, the dominant dissipative factors, namely, the dephasing effects of
the ground states and the imperfect initial state are no longer undesirable, in
fact, they are the important resources to the scheme. Therefore, the scheme
could provide more choices for the realization of the complete population
transfer in the strong dissipative fields


title: The free tangent structure

abstract:
  At the heart of differential geometry is the construction of the tangent
bundle of a manifold. There are various abstractions of this construction, and
this paper seeks to compare two of them: Synthetic Differential Geometry (SDG)
and Tangent Structures.
  Tangent structure is defined via giving an underlying category M and a
tangent functor T along with a list of natural transformations satisfying a set
of axioms, then detailing the behaviour of T in the category End(M). SDG on the
other hand is defined through the use of Weil algebras.
  The aim of this paper is to present a more precise relationship between the
two approaches for describing tangent structures.


title:
Approximate particle number distribution from direct stochastic sampling
  of the Wigner function

abstract:
  We consider the Wigner quasi-probability distribution function of a single
mode of an electromagnetic or matter-wave field to address the question of
whether a direct stochastic sampling and binning of the absolute square of the
complex field amplitude can yield a distribution function $\tilde{P}_n$ that
closely approximates the true particle number probability distribution $P_n$ of
the underlying quantum state. By providing an operational definition of the
binned distribution $\tilde{P}_n$ in terms of the Wigner function, we
explicitly calculate the overlap between $\tilde{P}_n$ and ${P}_n$ and hence
quantify the statistical distance between the two distributions. We find that
there is indeed a close quantitative correspondence between $\tilde{P}_n$ and
$P_n$ for a wide range of quantum states that have smooth and broad Wigner
function relative to the scale of oscillations of the Wigner function for the
relevant Fock state. However, we also find counterexamples, including states
with high mode occupation, for which $\tilde{P}_n$ does not closely approximate
$P_n$.


title:
Transferability in Machine Learning: from Phenomena to Black-Box Attacks
  using Adversarial Samples

abstract:
  Many machine learning models are vulnerable to adversarial examples: inputs
that are specially crafted to cause a machine learning model to produce an
incorrect output. Adversarial examples that affect one model often affect
another model, even if the two models have different architectures or were
trained on different training sets, so long as both models were trained to
perform the same task. An attacker may therefore train their own substitute
model, craft adversarial examples against the substitute, and transfer them to
a victim model, with very little information about the victim. Recent work has
further developed a technique that uses the victim model as an oracle to label
a synthetic training set for the substitute, so the attacker need not even
collect a training set to mount the attack. We extend these recent techniques
using reservoir sampling to greatly enhance the efficiency of the training
procedure for the substitute model. We introduce new transferability attacks
between previously unexplored (substitute, victim) pairs of machine learning
model classes, most notably SVMs and decision trees. We demonstrate our attacks
on two commercial machine learning classification systems from Amazon (96.19%
misclassification rate) and Google (88.94%) using only 800 queries of the
victim model, thereby showing that existing machine learning approaches are in
general vulnerable to systematic black-box attacks regardless of their
structure.


title:
Discrete Wavelet Transform-Based Prediction of Stock Index: A Study on
  National Stock Exchange Fifty Index

abstract:
  Financial Times Series such as stock price and exchange rates are, often,
non-linear and non-stationary. Use of decomposition models has been found to
improve the accuracy of predictive models. The paper proposes a hybrid approach
integrating the advantages of both decomposition model (namely, Maximal Overlap
Discrete Wavelet Transform (MODWT)) and machine learning models (ANN and SVR)
to predict the National Stock Exchange Fifty Index. In first phase, the data is
decomposed into a smaller number of subseries using MODWT. In next phase, each
subseries is predicted using machine learning models (i.e., ANN and SVR). The
predicted subseries are aggregated to obtain the final forecasts. In final
stage, the effectiveness of the proposed approach is evaluated using error
measures and statistical test. The proposed methods (MODWT-ANN and MODWT-SVR)
are compared with ANN and SVR models and, it was observed that the return on
investment obtained based on trading rules using predicted values of MODWT-SVR
model was higher than that of Buy-and-hold strategy.


title:
Evolution of Interfaces for the Nonlinear Parabolic p-Laplacian Type
  Reaction-Diffusion Equations

abstract:
  We present a full classification of the short-time behaviour of the
interfaces and local solutions to the nonlinear parabolic $p$-Laplacian type
reaction-diffusion equation of non-Newtonian elastic filtration \[
u_t-\Big(|u_x|^{p-2}u_x\Big)_x+bu^{\beta}=0, \ p>2, \beta >0 \] The interface
may expand, shrink, or remain stationary as a result of the competition of the
diffusion and reaction terms near the interface, expressed in terms of the
parameters $p,\beta, sign~b$, and asymptotics of the initial function near its
support. In all cases, we prove the explicit formula for the interface and the
local solution with accuracy up to constant coefficients. The methods of the
proof are based on nonlinear scaling laws, and a barrier technique using
special comparison theorems in irregular domains with characteristic boundary
curves.


title: Dynamics of Weyl quasiparticles emerged in an optical lattice

abstract:
  We investigate the dynamics of the Weyl quasiparticles emerged in an optical
lattice where the topological Weyl semimental and trivial band insulator phases
can be adjusted with the on-site energy. The evolution of the density
distribution is demonstrated to have an anomalous velocity in Weyl semimental
but a steady Zitterbewegung effect in the band insulator. Our analysis
demonstrates that the topological Chern number and the chirality of the system
can be directly determined from the positions of the atomic center-of-mass.
Furthermore, the amplitude and the period of the relativistic Zitterbewegung
oscillations are shown to be observable with the time-of-flight experiments.


title: High bandwidth on-chip capacitive tuning of microtoroid resonators

abstract:
  We report on the design, fabrication and characterization of silica
microtoroid based cavity opto-electromechanical systems (COEMS). Electrodes
patterned onto the microtoroid resonators allow for rapid capacitive tuning of
the optical whispering gallery mode resonances while maintaining their
ultrahigh quality factor, enabling applications such as efficient radio to
optical frequency conversion, optical routing and switching applications.


title:
Estimation of Mass of the Black Hole Candidate MAXI J1659-152 using TCAF
  and POS Models

abstract:
  The Galactic transient black hole candidate (BHC) MAXI~J1659-152 exhibited
temporal and spectral evolution during its very first X-ray outburst (2010)
after its discovery on 25th Sept. 2010. Our recent studies of a few transient
BHCs including MAXI~J1659-152 using Chakrabarti-Titarchuk two-component
advective flow (TCAF) solution as an additive table local model in XSPEC
revealed details of accretion flow dynamics around the black hole (BH). The
TCAF model fitted normalization (N) comes out to be almost constant throughout
the entire outburst consisting of several spectral states. We introduce two
independent methods to determine the mass ($M_{BH}$) of the BHC, namely, {\it
$i)$ keeping TCAF fitted normalization parameter in a narrow range}, and {\it
$ii)$ studying evolution of the Quasi-Periodic Oscillation frequency
($\nu_{QPO}$) with time, fitted with the propagating oscillatory shock (POS)
model}. The predicted mass ranges of the source with these two methods are
$4.7-7.8~M_\odot$, and $5.1-7.4~M_\odot$ respectively. Combining results of
these two methods, we obtain a most probable mass range of the source to be
$4.7-7.8~M_\odot$ or $6^{+1.8}_{-1.3}~M_\odot$.


title:
Quantitative recurrence properties for systems with non-uniform
  structure

abstract:
  Let X be a subshift satisfy non-uniform structure. In this paper, we give
quantitative estimate of the recurrence sets. These results can be applied to a
large class of symbolic systems, including beta-shifts, S-gap shifts and their
factors.


title:
Functional Forms of Optimum Spoofing Attacks for Vector Parameter
  Estimation in Quantized Sensor Networks

abstract:
  Estimation of an unknown deterministic vector from quantized sensor data is
considered in the presence of spoofing attacks which alter the data presented
to several sensors. Contrary to previous work, a generalized attack model is
employed which manipulates the data using transformations with arbitrary
functional forms determined by some attack parameters whose values are unknown
to the attacked system. For the first time, necessary and sufficient conditions
are provided under which the transformations provide a guaranteed attack
performance in terms of Cramer-Rao Bound (CRB) regardless of the processing the
estimation system employs, thus defining a highly desirable attack.
Interestingly, these conditions imply that, for any such attack when the
attacked sensors can be perfectly identified by the estimation system, either
the Fisher Information Matrix (FIM) for jointly estimating the desired and
attack parameters is singular or that the attacked system is unable to improve
the CRB for the desired vector parameter through this joint estimation even
though the joint FIM is nonsingular. It is shown that it is always possible to
construct such a highly desirable attack by properly employing a sufficiently
large dimension attack vector parameter relative to the number of quantization
levels employed, which was not observed previously. To illustrate the theory in
a concrete way, we also provide some numerical results which corroborate that
under the highly desirable attack, attacked data is not useful in reducing the
CRB.


title: Deterministic Time-Space Tradeoffs for k-SUM

abstract:
  Given a set of numbers, the $k$-SUM problem asks for a subset of $k$ numbers
that sums to zero. When the numbers are integers, the time and space complexity
of $k$-SUM is generally studied in the word-RAM model; when the numbers are
reals, the complexity is studied in the real-RAM model, and space is measured
by the number of reals held in memory at any point.
  We present a time and space efficient deterministic self-reduction for the
$k$-SUM problem which holds for both models, and has many interesting
consequences. To illustrate:
  * $3$-SUM is in deterministic time $O(n^2 \lg\lg(n)/\lg(n))$ and space
$O\left(\sqrt{\frac{n \lg(n)}{\lg\lg(n)}}\right)$. In general, any
polylogarithmic-time improvement over quadratic time for $3$-SUM can be
converted into an algorithm with an identical time improvement but low space
complexity as well. * $3$-SUM is in deterministic time $O(n^2)$ and space
$O(\sqrt n)$, derandomizing an algorithm of Wang.
  * A popular conjecture states that 3-SUM requires $n^{2-o(1)}$ time on the
word-RAM. We show that the 3-SUM Conjecture is in fact equivalent to the
(seemingly weaker) conjecture that every $O(n^{.51})$-space algorithm for
$3$-SUM requires at least $n^{2-o(1)}$ time on the word-RAM.
  * For $k \ge 4$, $k$-SUM is in deterministic $O(n^{k - 2 + 2/k})$ time and
$O(\sqrt{n})$ space.


title:
Differential operators on the superline, Berezinians, and Darboux
  transformations

abstract:
  We consider differential operators on a supermanifold of dimension $1|1$. We
define non-degenerate operators as those with an invertible top coefficient in
the expansion in the "superderivative" $D$ (which is the square root of the
shift generator, the partial derivative in an even variable, with the help of
an odd indeterminate). They are remarkably similar to ordinary differential
operators. We show that every non-degenerate operator can be written in terms
of `super Wronskians' (which are certain Berezinians). We apply this to Darboux
transformations (DTs), proving that every DT of an arbitrary non-degenerate
operator is the composition of elementary first order transformations. Hence
every DT corresponds to an invariant subspace of the source operator and, upon
a choice of basis in this subspace, is expressed by a super-Wronskian formula.
We consider also dressing transformations, i.e., the effect of a DT on the
coefficients of the non-degenerate operator. We calculate these transformations
in examples and make some general statements.


title:
Stimulated Brillouin scattering and Brillouin-coupled four-wave-mixing
  in a silica microbottle resonator

abstract:
  We report the first observation of stimulated Brillouin scattering (SBS) with
Brillouin lasing, and Brillouin-coupled four-wave-mixing (FWM) in an
ultra-high-Q silica microbottle resonator. The Brillouin lasing was observed at
the frequency of $\Omega_B=2\pi\times10.4$ GHz with a threshold power of $0.45$
mW. Coupling between Brillouin and FWM was observed in both backward and
forward scattering directions with separations of $2\Omega_B$. At a pump power
of $10$ mW, FWM spacing reached to 7th and 9th order anti-Stokes and Stokes,
respectively.


title:
Controlling slow and fast light and dynamic pulse-splitting with tunable
  optical gain in a whispering-gallery-mode microcavity

abstract:
  We report controllable manipulation of slow and fast light in a
whispering-gallery-mode (WGM) microtoroid resonator fabricated from Erbium
(Er3+) doped silica. We observe continuous transition of the coupling between
the fiber-taper waveguide and the microresonator from undercoupling to critical
coupling and then to overcoupling regimes by increasing the pump power even
though the spatial distance between the resonator and the waveguide was kept
fixed. This, in turn, enables switching from fast to slow light and vice versa
just by increasing the optical gain. An enhancement of delay of two-fold over
the passive silica resonator (no optical gain) was observed in the slow light
regime. Moreover, we show dynamic pulse splitting and its control in slow/fast
light systems using optical gain.


title: EventNet Version 1.1 Technical Report

abstract:
  EventNet is a large-scale video corpus and event ontology consisting of 500
events associated with event-specific concepts. In order to improve the quality
of the current EventNet, we conduct the following steps and introduce EventNet
version 1.1: (1) manually verify the correctness of event labels for all
videos; (2) remove the YouTube user bias by limiting the maximum number of
videos in each event from the same YouTube user as 3; (3) remove the videos
which are currently not accessible online; (4) remove the video belonging to
multiple event categories. After the above procedure, some events may contain
only a small number of videos, and therefore we crawl more videos for those
events to ensure every event will contain more than 50 videos. Finally,
EventNet version 1.1 contains 67,641 videos, 500 events, and 5,028
event-specific concepts. In addition, we train a Convolutional Neural Network
(CNN) model for event classification via fine-tuning AlexNet using EventNet
version 1.1. Then we use the trained CNN model to extract FC7 layer feature and
train binary classifiers using linear SVM for each event-specific concept. We
believe this new version of EventNet will significantly facilitate research in
computer vision and multimedia, and will put it online for public downloading
in the future.


title: Design of an optical-communication link with Mars

abstract:
  The possibility of using optical communications in free-space as an
improvement of current RF communication systems was analyzed in this Project.
The particular case of a link Mars-Earth was studied and a link based in the
future NASA's MLCD project, which is currently being developed, was designed.
For this, an orbit simulator was programmed, evaluating the transfer orbit,
analyzing the losses that occur in the transmission channel, using several
atmospheric models, selecting the most adequate elements for the transmitter
and the receiver, calculating the Doppler effect during the mission, and
performing a budget link for the different orbit positions. From these results,
the maximum bitrate through the MLCD mission was evaluated for the different
astronomical observatories chosen as optical ground stations.


title:
Absolute continuity of harmonic measure for domains with lower regular
  boundaries

abstract:
  We study absolute continuity of harmonic measure with respect to surface
measure on domains $\Omega$ that have large complements. We show that if
$\Gamma\subset \mathbb{R}^{d+1}$ is $d$-Ahlfors regular and splits $
\mathbb{R}^{d+1}$ into two NTA domains then $\omega_{\Omega}\ll
\mathscr{H}^{d}$ on $\Gamma\cap \partial\Omega$. This result is a natural
generalisation of a result of Wu in [Wu86].
  We also prove that almost every point in $\Gamma\cap\partial\Omega$ is a cone
point if $\Gamma$ is a Lipschitz graph. Combining these results and a result
from [AHMMMTV], we characterize sets of absolute continuity with finite
$\mathscr{H}^{d}$-measure both in terms of the cone point condition and in
terms of the rectifiable structure of the boundary. This generalizes the
results of McMillan in [McM69] and Pommerenke in [Pom86].
  Finally, we also show our first result holds for elliptic measure associated
with real second order divergence form elliptic operators with a mild
assumption on the gradient of the matrix.


title:
The Fadell-Rabinowitz index and multiplicity of non-contractible closed
  geodesics on Finsler $\mathbb{R}P^{n}$

abstract:
  In this paper, we prove that for every irreversible Finsler $n$-dimensional
real projective space $(\mathbb{R}P^n,F)$ with reversibility $\lambda$ and flag
curvature $K$ satisfying
$\frac{16}{9}\left(\frac{\lambda}{1+\lambda}\right)^2<K\le 1$ with $\lambda<3$,
there exist at least $n-1$ non-contractible closed geodesics. In addition, if
the metric $F$ is bumpy with
$\frac{64}{25}\left(\frac{\lambda}{1+\lambda}\right)^2<K\le 1$ and
$\lambda<\frac{5}{3}$, then there exist at least $2[\frac{n+1}{2}]$
non-contractible closed geodesics, which is the optimal lower bound due to
Katok's example. The main ingredients of the proofs are the Fadell-Rabinowitz
index theory of non-contractible closed geodesics on $(\mathbb{R}P^n,F)$ and
the $S^1$-equivariant Poincar$\acute{e}$ series of the non-contractible
component of the free loop space on $\mathbb{R}P^n$.


title:
Exact formulas for the proximal/regular/limiting normal cone of the
  second-order cone complementarity set

abstract:
  The proximal, regular and limiting normal cones to the second-order cone
complementarity set play important roles in studying mathematical programs with
second-order cone complementarity constraints, second-order cone programs, and
the second-order cone complementarity problems. It is needed in the first-order
optimality conditions for mathematical programs with second-order cone
complementarity constraint, the second-order subdifferential criteria in
characterizing the full stability for second-order cone programs and
second-order cone complementarity problems, as well as in the characterizing
the pseudo-Lipschitz continuity of the solution mapping to parametric
second-order cone complementarity problems. In this paper we establish explicit
formulas for the proximal, regular, and limiting normal cone of the
second-order cone complementarity set.


title:
Directly measuring single molecule heterogeneity using force
  spectroscopy

abstract:
  One of the most intriguing results of single molecule experiments on proteins
and nucleic acids is the discovery of functional heterogeneity: the observation
that complex cellular machines exhibit multiple, biologically active
conformations. The structural differences between these conformations may be
subtle, but each distinct state can be remarkably long-lived, with random
interconversions between states occurring only at macroscopic timescales,
fractions of a second or longer. Though we now have proof of functional
heterogeneity in a handful of systems---enzymes, motors, adhesion
complexes---identifying and measuring it remains a formidable challenge. Here
we show that evidence of this phenomenon is more widespread than previously
known, encoded in data collected from some of the most well-established single
molecule techniques: AFM or optical tweezer pulling experiments. We present a
theoretical procedure for analyzing distributions of rupture/unfolding forces
recorded at different pulling speeds. This results in a single parameter,
quantifying the degree of heterogeneity, and also leads to bounds on the
equilibration and conformational interconversion timescales. Surveying ten
published datasets, we find heterogeneity in five of them, all with
interconversion rates slower than 10 s$^{-1}$. Moreover, we identify two
systems where additional data at realizable pulling velocities is likely to
find a theoretically predicted, but so far unobserved cross-over regime between
heterogeneous and non-heterogeneous behavior. The significance of this regime
is that it will allow far more precise estimates of the slow conformational
switching times, one of the least understood aspects of functional
heterogeneity.


title:
Systematics of dynamic moment of inertia in super-deformed bands in Mass
  ~150 region

abstract:
  An empirical semi-classical model have been proposed to investigate the
nature of dynamic moment-of-inertia , of the super-deformed (SD) bands in
nuclei of mass 150 region. The model incorporates an additional frequency
dependent distortion, to the dynamic moment-of-inertia term akin to a
vibrational component to explain the extreme spin structure of these bands.
Using this model two separate components to the dynamic moment of inertia,
$\Im^{(2)}$ have been identified for the SD band structure for the mass 150
region. Three distinct nature of the moment-of-inertia, also have been
identified using the two parameter model.


title:
Multipion correlations induced by isospin conservation of coherent
  emission

abstract:
  Recent measurements have revealed a significant suppression of multipion
Bose-Einstein correlations in heavy-ion collisions at the LHC. The suppression
may be explained by postulating coherent pion emission. Typically, the
suppression of Bose-Einstein correlations due to coherence is taken into
account with the coherent state formalism in quantum optics. However, since
charged pion correlations are most often measured, the additional constraint of
isospin conservation, which is absent in quantum optics, needs to be taken into
account. As a consequence, correlations emerge between pions of opposite
charge. A calculation of the correlations induced by isospin conservation of
coherent emission is made for two, three- and four-pion correlation functions
and compared to the data from the LHC.


title:
Fault-tolerant and finite-error localization for point emitters within
  the diffraction limit

abstract:
  We implement an estimator for determining the separation between two
incoherent point sources. This estimator relies on image inversion
interferometry and when used with the appropriate data analytics, it yields an
estimate of the separation with finite-error, even when the sources come
arbitrarily close together. The experimental results show that the technique
has a good tolerance to noise and misalignment, making it an interesting
consideration for high resolution instruments.


title:
Witnessing topological Weyl semimetal phase in a minimal circuit-QED
  lattice

abstract:
  We present a feasible protocol to mimic topological Weyl semimetal phase in a
small one-dimensional circuit-QED lattice. By modulating the photon hopping
rates and on-site photon frequencies in parametric spaces, we demonstrate that
the momentum space of this one-dimensional lattice model can be artificially
mapped to three dimensions accompanied by the emergence of topological Weyl
semimetal phase. Furthermore, via a lattice-based cavity input-output process,
we show that all the essential topological features of Weyl semimetal phase,
including the topological charge associated with each Weyl point and the open
Fermi arcs, can be unambiguously detected in a circuit with four dissipative
resonators by measuring the reflection spectra. These remarkable features may
open a new prospect in using well-controlled small quantum lattices to mimic
and study topological phases.


title: Bessel orbits of normal operators

abstract:
  Given a bounded normal operator $A$ in a Hilbert space and a fixed vector
$x$, we elaborate on the problem of finding necessary and sufficient conditions
under which $(A^kx)_{k\in\mathbb N}$ constitutes a Bessel sequence. We provide
a characterization in terms of the measure $\|E(\cdot)x\|^2$, where $E$ is the
spectral measure of the operator $A$. In the separately treated special cases
where $A$ is unitary or selfadjoint we obtain more explicit characterizations.
Finally, we apply our results to a sequence $(A^kx)_{k\in\mathbb N}$, where $A$
arises from the heat equation. The problem is motivated by and related to the
new field of Dynamical Sampling which was recently initiated by Aldroubi et al.


title:
Distance and extinction determination for APOGEE stars with Bayesian
  method

abstract:
  Using a Bayesian technology we derived distances and extinctions for over
100,000 red giant stars observed by the Apache Point Observatory Galactic
Evolution Experiment (APOGEE) survey by taking into account spectroscopic
constraints from the APOGEE stellar parameters and photometric constraints from
2MASS, as well as a prior knowledge on the Milky Way. Derived distances are
compared with those from four other independent methods, the Hipparcos
parallaxes, star clusters, APOGEE red clump stars, and asteroseismic distances
from APOKASC (Rodrigues et al. 2014) and SAGA Catalogues (Casagrande et al.
2014). These comparisons covers four orders of magnitude in the distance scale
from 0.02 kpc to 20 kpc. The results show that our distances agree very well
with those from other methods: the mean relative difference between our
Bayesian distances and those derived from other methods ranges from -4.2% to
+3.6%, and the dispersion ranges from 15% to 25%. The extinctions toward all
stars are also derived and compared with those from several other independent
methods: the Rayleigh-Jeans Color Excess (RJCE) method, Gonzalez's
two-dimensional extinction map, as well as three-dimensional extinction maps
and models. The comparisons reveal that, overall, estimated extinctions agree
very well, but RJCE tends to overestimate extinctions for cool stars and
objects with low logg.


title:
The Optical Variability of SDSS Quasars from Multi-epoch Spectroscopy.
  III. A Sudden UV Cutoff in Quasar SDSS J2317+0005

abstract:
  We have collected near-infrared to X-ray data of 20 multi-epoch heavily
reddened SDSS quasars to investigate the physical mechanism of reddening. Of
these, J2317+0005 is found to be a UV cutoff quasar. Its continuum, which
usually appears normal, decreases by a factor 3.5 at 3000{\AA}, compared to its
more typical bright state during an interval of 23 days. During this sudden
continuum cut-off, the broad emission line fluxes do not change, perhaps due to
the large size of the Broad Line Region (BLR), r > 23 / (1+z) days. The UV
continuum may have suffered a dramatic drop out. However, there are some
difficulties with this explanation. Another possibility is that the intrinsic
continuum did not change, but was temporarily blocked out, at least towards our
line of sight. As indicated by X-ray observations, the continuum rapidly
recovers after 42 days. A comparison of the bright state and dim states would
imply an eclipse by a dusty cloud with a reddening curve having a remarkably
sharp rise shortward of 3500{\AA}. Under the assumption of being eclipsed by a
Keplerian dusty cloud, we characterized the cloud size with our observations,
however, which is a little smaller than the 3000\AA\ continuum-emitting size
inferred from accretion disk models. Therefore, we speculate this is due to a
rapid outflow or inflow with a dusty cloud passing through our line-of-sight to
the center.


title:
Surface scattering effect and the stripe order in films of the
  superfluid $^3$He B phase

abstract:
  Surface scattering effects in thin films of the superfluid 3He B phase have
been theoretically investigated, with an emphasis on the stability of the
stripe order with spontaneous broken translational symmetry in the film plane
and quasiparticle excitations in this spatially inhomogeneous phase. Based on
the Ginzburg-Landau theory in the weak coupling limit, we have shown that the
stripe order, which was originally discussed for a film with two specular
surfaces, can be stable in a film with one specular and one diffusive surfaces
which should correspond to superfluid 3He on a substrate. It is also found by
numerically solving the Eilenberger equation that due to the stripe structure,
a midgap state distinct from the surface Andreev bound state emerges and its
signature is reflected in the local density of states.


title:
Incorporating a Spatial Prior into Nonlinear D-Bar EIT imaging for
  Complex Admittivities

abstract:
  Electrical Impedance Tomography (EIT) aims to recover the internal
conductivity and permittivity distributions of a body from electrical
measurements taken on electrodes on the surface of the body. The reconstruction
task is a severely ill-posed nonlinear inverse problem that is highly sensitive
to measurement noise and modeling errors. Regularized D-bar methods have shown
great promise in producing noise-robust algorithms by employing a low-pass
filtering of nonlinear (nonphysical) Fourier transform data specific to the EIT
problem. Including prior data with the approximate locations of major organ
boundaries in the scattering transform provides a means of extending the radius
of the low-pass filter to include higher frequency components in the
reconstruction, in particular, features that are known with high confidence.
This information is additionally included in the system of D-bar equations with
an independent regularization parameter from that of the extended scattering
transform. In this paper, this approach is used in the 2-D D-bar method for
admittivity (conductivity as well as permittivity) EIT imaging. Noise-robust
reconstructions are presented for simulated EIT data on chest-shaped phantoms
with a simulated pneumothorax and pleural effusion. No assumption of the
pathology is used in the construction of the prior, yet the method still
produces significant enhancements of the underlying pathology (pneumothorax or
pleural effusion) even in the presence of strong noise.


title: Modeling delayed processes in biological systems

abstract:
  Delayed processes are ubiquitous in biological systems and are often
characterized by delay differential equations (DDEs) and their extension to
include stochastic effects. DDEs do not explicitly incorporate intermediate
states associated with a delayed process but instead use an estimated average
delay time. In an effort to examine the validity of this approach, we study
systems with significant delays by explicitly incorporating intermediate steps.
We show by that such explicit models often yield significantly different
equilibrium distributions and transition times as compared to DDEs with
deterministic delay values. Additionally, different explicit models with
qualitatively different dynamics can give rise to the same DDEs revealing
important ambiguities. We also show that DDE-based predictions of oscillatory
behavior may fail for the corresponding explicit model.


title:
Limitations of Time Resources in Human Relationships Determine Social
  Structures

abstract:
  A single human can be involved in a limited number of social relationships,
and the distribution of strengths of such relationships shows significant skew.
This skewness suggests that the costs and benefits of the social interactions
required to bond with others (social grooming) depend on the social
relationship strength: if they involved uniform costs and benefits, the
distribution would not be skew. Here, we show that the cost of social grooming
increases with the social relationship strength, and its gradient determines
the structures of these relationships in society as evident from an analysis of
data from six communication systems. This may be due to an increase in
communication volumes, such as number of characters and duration of calls,
along with an increase in the social relationship strength. We tested this
hypothesis using an individual-based simulation where social grooming costs
were assumed to increase linearly with the social relationship strength; this
is the simplest assumption. The results indicated that this model fitted all
data sets, i.e., it showed an explanation capacity for the phenomenon.
Additionally, an analysis of this simulation suggested that the gradient of
social grooming costs increases the width and shallowness of social
relationships in its communication system.


title:
Fluid forces or impacts: What governs the entrainment of soil particles
  in sediment transport mediated by a Newtonian fluid?

abstract:
  In steady sediment transport, sediment deposition is balanced by entrainment
of bed particles by fluid forces or particle-bed impacts. Here we propose a
proxy to determine the role of impact entrainment relative to entrainment by
the mean turbulent flow: the "bed velocity" $V_b$, which is an effective
near-bed-surface value of the average horizontal particle velocity that
generalizes the classical slip velocity, used in studies of aeolian saltation
transport, to sediment transport in an arbitrary Newtonian fluid. We study
$V_b$ for a wide range of the particle-fluid-density ratio $s$, Galileo number
$\mathrm{Ga}$, and Shields number $\Theta$ using direct sediment transport
simulations. We find that transport is fully sustained through impact
entrainment (i.e., $V_b$ is constant in natural units) when the "impact number"
$\mathrm{Im}=\mathrm{Ga}\sqrt{s+0.5}\gtrsim20$ or $\Theta\gtrsim5/\mathrm{Im}$.
These conditions are obeyed for the vast majority of transport regimes,
including steady turbulent bedload, which has long been thought to be sustained
solely through fluid entrainment. In fact, we find that transport is fully
sustained through fluid entrainment (i.e., $V_b$ scales with the near-bed
horizontal fluid velocity) only for sufficiently viscous bedload transport at
grain scale (i.e., for $\mathrm{Im}\lesssim20$ and
$\Theta\lesssim1/\mathrm{Im}$). Finally, we do not find a strong correlation
between, $V_b$, or the classical slip velocity, and the
transport-layer-averaged horizontal particle velocity $\overline{v_x}$, which
challenges the long-standing consensus that predominant impact entrainment is
responsible for a linear scaling of the transport rate with $\Theta$. For
turbulent bedload in particular, $\overline{v_x}$ increases with $\Theta$
despite $V_b$ remaining constant, which we propose is linked to the formation
of a liquid-like bed on top of the static-bed surface.


title:
Revealing and Characterizing Dark Excitons Through Coherent
  Multidimensional Spectroscopy

abstract:
  Dark excitons are of fundamental importance in a broad range of contexts, but
are difficult to study using conventional optical spectroscopy due to their
weak interaction with light. We show how coherent multidimensional spectroscopy
can reveal and characterize dark states. Using this approach, we identify
different types of dark excitons in InGaAs/GaAs quantum wells and determine
details regarding lifetimes, homogeneous and inhomogeneous linewidths,
broadening mechanisms and coupling strengths. The observations of coherent
coupling between bright and dark excitons hint at a role for a multi-step
process by which excitons in the barrier can relax into the quantum wells.

categories: physics.optics cond-mat.mes-hall cond-mat.mtrl-sci cond-mat.other


title: Series of broad resonances in atomic three-body systems

abstract:
  We re-examine the series of resonances found earlier in atomic three-body
systems by solving the Faddeev-Merkuriev integral equations. These resonances
are rather broad and line-up at each threshold with gradually increasing gaps,
the same way for all thresholds and irrespective of the spatial symmetry. We
relate these resonances to the Gailitis mechanism, which is a consequence of
the polarization potential.


title:
3D Print of Polymer Bonded Rare-Earth Magnets, and 3D Magnetic Field
  Scanning With an End-User 3D Printer

abstract:
  3D print is a recently developed technique, for single-unit production, and
for structures that have been impossible to build previously. The current work
presents a method to 3D print polymer bonded isotropic hard magnets with a
low-cost, end-user 3D printer. Commercially available isotropic NdFeB powder
inside a PA11 matrix is characterized, and prepared for the printing process.
An example of a printed magnet with a complex shape that was designed to
generate a specific stray field is presented, and compared with finite element
simulation solving the macroscopic Maxwell equations. For magnetic
characterization, and comparing 3D printed structures with injection molded
parts, hysteresis measurements are performed. To measure the stray field
outside the magnet, the printer is upgraded to a 3D magnetic flux density
measurement system. To skip an elaborate adjusting of the sensor, a simulation
is used to calibrate the angles, sensitivity, and the offset of the sensor.
With this setup a measurement resolution of 0.05\,mm along the z-axes is
achievable. The effectiveness of our novel calibration method is shown.
  With our setup we are able to print polymer bonded magnetic systems with the
freedom of having a specific complex shape with locally tailored magnetic
properties. The 3D scanning setup is easy to mount, and with our calibration
method we are able to get accurate measuring results of the stray field.


title:
One-dimensional Schr\"odinger equation with non-analytic potential
  $V(x)= -g^2\exp (-|x|)$ and its exact Bessel-function solvability

abstract:
  Exact solvability (ES) of one-dimensional quantum potentials $V(x)$ is a
vague concept. We propose that beyond its most conventional range the ES status
should be attributed also to many less common interaction models for which the
wave functions remain piecewise proportional to special functions. The claim is
supported by constructive analysis of a toy model $V(x)= -g^2\exp (-|x|)$. The
detailed description of the related bound-state and scattering solutions of
Schr\"{o}dinger equation is provided in terms of Bessel functions which are
properly matched in the origin.

categories: math-ph hep-th math.CA math.MP nlin.SI quant-ph


title:
Quantum-to-classical transition and imprints of continuous spontaneous
  localization in classical bouncing universes

abstract:
  The perturbations in the early universe are generated as a result of the
interplay between quantum field theory and gravitation. Since these primordial
perturbations lead to the anisotropies in the cosmic microwave background and
eventually to the inhomogeneities in the Large Scale Structure (LSS), they
provide a unique opportunity to probe issues which are fundamental to our
understanding of quantum physics and gravitation. One such fundamental issue
that remains to be satisfactorily addressed is the transition of the primordial
perturbations from their quantum origins to the LSS which can be characterized
completely in terms of classical quantities. Classical bouncing universes
provide an alternative to the more conventional inflationary paradigm as they
can help overcome the horizon problem in a fashion very similar to inflation.
While the problem of the quantum-to-classical transition of the primordial
perturbations has been investigated extensively in the context of inflation, we
find that there has been a rather limited effort towards studying the issue in
classical bouncing universes. In this work, we analyze certain aspects of this
problem with the example of tensor perturbations produced in classical matter
and near-matter bouncing universes. We investigate the issue mainly from two
perspectives. Firstly, we approach the problem by examining the extent of
squeezing of a quantum state associated with the tensor perturbations with the
help of the Wigner function. Secondly, we analyze the issue from the
perspective of the quantum measurement problem. In particular, we study the
effects of wave function collapse, using a phenomenological model known as
continuous spontaneous localization, on the tensor power spectra. We conclude
with a discussion of results.


title: Representation and design of wavelets using unitary circuits

abstract:
  The representation of discrete, compact wavelet transformations (WTs) as
circuits of local unitary gates is discussed. We employ a similar formalism as
used in the multi-scale representation of quantum many-body wavefunctions using
unitary circuits, further cementing the relation established in [Phys. Rev.
Lett. 116, 140403 (2016)] between classical and quantum multi-scale methods. An
algorithm for constructing the circuit representation of known orthogonal,
dyadic, discrete WTs is presented, and the explicit representation for
Daubechies wavelets, coiflets, and symlets is provided. Furthermore, we
demonstrate the usefulness of the circuit formalism in designing novel WTs,
including various classes of symmetric wavelets and multi-wavelets, boundary
wavelets and biorthogonal wavelets.


title: LHC signatures of neutral pseudo-Goldstone boson in the E6CHM

abstract:
  The breakdown of the SU(6) global symmetry to its SU(5) subgroup, that
contains the standard model (SM) gauge group, in the E6 inspired composite
Higgs model (E6CHM) results in a set of pseudo-Nambu-Goldstone bosons (pNGBs).
This set, in particular, involves the SM-like Higgs doublet and a SM singlet
boson. In the limit when CP is conserved the SM singlet scalar A is a CP-odd
state that does not mix with the SM-like Higgs. The interactions of A with
exotic matter beyond the SM, which ensures anomaly cancellation and approximate
gauge coupling unification, can induce couplings of this pseudoscalar to the SM
gauge bosons. We specify the interactions of the SM singlet pNGB state with the
exotic vector-like fermions, top quark and SM gauge bosons. Also we explore the
dependence of the branching ratios of the pseudoscalar A and its LHC production
cross section on the parameters of the E6CHM.


title:
DeepText: A Unified Framework for Text Proposal Generation and Text
  Detection in Natural Images

abstract:
  In this paper, we develop a novel unified framework called DeepText for text
region proposal generation and text detection in natural images via a fully
convolutional neural network (CNN). First, we propose the inception region
proposal network (Inception-RPN) and design a set of text characteristic prior
bounding boxes to achieve high word recall with only hundred level candidate
proposals. Next, we present a powerful textdetection network that embeds
ambiguous text category (ATC) information and multilevel region-of-interest
pooling (MLRP) for text and non-text classification and accurate localization.
Finally, we apply an iterative bounding box voting scheme to pursue high recall
in a complementary manner and introduce a filtering algorithm to retain the
most suitable bounding box, while removing redundant inner and outer boxes for
each text instance. Our approach achieves an F-measure of 0.83 and 0.85 on the
ICDAR 2011 and 2013 robust text detection benchmarks, outperforming previous
state-of-the-art results.


title: The paradoxical zero reflection at zero energy

abstract:
  Usually, the reflection probability $R(E)$ of a particle of zero energy
incident on a potential which converges to zero asymptotically is found to be
1: $R(0)=1$. But earlier, a paradoxical phenomenon of zero reflection at zero
energy ($R(0)=0$) has been revealed as a threshold anomaly. Extending the
concept of Half Bound State (HBS) of 3D, here we show that in 1D when a
symmetric (asymmetric) attractive potential well possesses a zero-energy HBS,
$R(0)=0$ $(R(0)<<1)$. This can happen only at some critical values $q_c$ of an
effective parameter $q$ of the potential well in the limit $E \rightarrow 0^+$.
We demonstrate this critical phenomenon in two simple analytically solvable
models which are square and exponential wells. However, in numerical
calculations even for these two models $R(0)=0$ is observed only as
extrapolation to zero energy from low energies, close to a precise critical
value $q_c$. By numerical investigation of a variety of potential wells, we
conclude that for a given potential well (symmetric or asymmetric), we can
adjust the effective parameter $q$ to have a low reflection at a low energy.


title:
Multimodal Interaction with Multiple Co-located Drones in Search and
  Rescue Missions

abstract:
  We present a multimodal interaction framework suitable for a human rescuer
that operates in proximity with a set of co-located drones during search
missions. This work is framed in the context of the SHERPA project whose goal
is to develop a mixed ground and aerial robotic platform to support search and
rescue activities in a real-world alpine scenario. Differently from typical
human-drone interaction settings, here the operator is not fully dedicated to
the drones, but involved in search and rescue tasks, hence only able to provide
sparse, incomplete, although high-value, instructions to the robots. This
operative scenario requires a human-interaction framework that supports
multimodal communication along with an effective and natural mixed-initiative
interaction between the human and the robots. In this work, we illustrate the
domain and the proposed multimodal interaction framework discussing the system
at work in a simulated case study.


title:
Fatigue effect on polarization switching dynamics in polycrystalline
  bulk ferroelectrics

abstract:
  Statistical distribution of switching times is a key information necessary to
describe the dynamic response of a polycrystalline bulk ferroelectric to an
applied electric field. The Inhomogeneous Field Mechanism (IFM) model offers a
useful tool which allows extraction of this information from polarization
switching measurements over a large time window. In this paper, the model was
further developed to account for the presence of non-switchable regions in
fatigued materials. Application of the IFM- analysis to bipolar electric
cycling induced fatigue process of various lead-based and lead-free
ferroelectric ceramics reveals different scenarios of property degradation.
Insight is gained into different underlying fatigue mechanisms inherent to the
investigated systems.


title:
Actomyosin pulsation and symmetry breaking flows in a confined active
  elastomer subject to affine and nonaffine deformations

abstract:
  Tissue remodelling in diverse developmental contexts require cell shape
changes that have been associated with pulsation and flow of the actomyosin
cytoskeleton. Here we describe the dynamics of the actomyosin cytoskeleton as a
confined active elastomer embedded in the cytosol and subject to turnover of
its components. Under affine deformations (homogeneous deformation over a
spatially coarse-grained scale), the active elastomer exhibits spontaneous
oscillations, propagating waves, contractile collapse and spatiotemporal chaos.
The collective nonlinear dynamics shows nucleation, growth and coalescence of
actomyosin-dense regions which, beyond a threshold, spontaneously move as a
spatially localized traveling front towards one of the boundaries. However,
large myosin-induced contractile stresses, can lead to nonaffine deformations
due to actin turnover. This results in a transient actin network, that
naturally accommodates intranetwork flows of the actomyosin dense regions as a
consequence of filament unbinding and rebinding. Our work suggests that the
driving force for the spontaneous movement comes from the actomyosin-dense
region itself and not the cell boundary. We verify the many predictions of our
study in Drosophila embryonic epithelial cells undergoing neighbour exchange
during a collective process of tissue extension called germband extension.


title: Superconductivity in Uranium Ferromagnets

abstract:
  The theoretical description and the survey of physical properties of
superconducting states in the uranium ferromagnetic materials are presented. On
the basis of microscopic theory is shown that the coupling between the
electrons in these ferromagnetic metals by means of magnetization fluctuations
gives rise the triplet pairing superconducting state and the general form of
the order parameter dictated by the symmetry is established.
  The theory allows to explain some specific observations including peculiar
phenomenon of reentrant superconductivity in URhGe in magnetic field
perpendicular to the direction of spontaneous magnetization.
  In addition we describe several particular topics relating to uranium
superconducting ferromagnets: (i) critical magnetic relaxation in dual
localized-itinerant ferromagnets, (ii) phase transition to ferromagnetic state
in Fermi liquid and UGe$_2$, (iii) superconducting ordering in ferromagnetic
metals without inversion symmetry.


title:
Robust $H_\infty$ Coherent-Classical Estimation of Linear Quantum
  Systems

abstract:
  We study robust $H_\infty$ coherent-classical estimation for a class of
physically realizable linear quantum systems with parameter uncertainties. Such
a robust coherent-classical estimator, with or without coherent feedback, can
yield better disturbance-to-error performance than the corresponding robust
purely-classical estimator for an uncertain plant. Moreover, coherent feedback
allows for such a robust coherent-classical estimator to be more robust to
uncertainty in comparison to the robust classical-only estimator.


title: Beyond the Borsuk-Ulam theorem: The topological Tverberg story

abstract:
  B\'ar\'any's "topological Tverberg conjecture" from 1976 states that any
continuous map of an $N$-simplex $\Delta_N$ to $\mathbb{R}^d$, for
$N\ge(d+1)(r-1)$, maps points from $r$ disjoint faces in $\Delta_N$ to the same
point in $\mathbb{R}^d$. The proof of this result for the case when $r$ is a
prime, as well as some colored version of the same result, using the results of
Borsuk-Ulam and Dold on the non-existence of equivariant maps between spaces
with a free group action, were main topics of Matou\v{s}ek's 2003 book "Using
the Borsuk-Ulam theorem."
  In this paper we show how advanced equivariant topology methods allow one to
go beyond the prime case of the topological Tverberg conjecture.
  First we explain in detail how equivariant cohomology tools (employing the
Borel construction, comparison of Serre spectral sequences, Fadell-Husseini
index, etc.) can be used to prove the topological Tverberg conjecture whenever
$r$ is a prime power. Our presentation includes a number of improved proofs as
well as new results, such as a complete determination of the Fadell-Husseini
index of chessboard complexes in the prime case.
  Then we introduce the "constraint method," which applied to suitable
"unavoidable complexes" yields a great variety of variations and corollaries to
the topological Tverberg theorem, such as the "colored" and the
"dimension-restricted" (Van Kampen-Flores type) versions.
  Both parts have provided crucial components to the recent spectacular
counter-examples in high dimensions for the case when $r$ is not a prime power.


title: Recognizing Simple-Triangle Graphs by Restricted 2-Chain Subgraph Cover

abstract:
  A simple-triangle graph (also known as a PI graph) is the intersection graph
of a family of triangles defined by a point on a horizontal line and an
interval on another horizontal line. The recognition problem for
simple-triangle graphs was a longstanding open problem, and recently a
polynomial-time algorithm has been given [G. B. Mertzios, The Recognition of
Simple-Triangle Graphs and of Linear-Interval Orders is Polynomial, SIAM J.
Discrete Math., 29(3):1150--1185, 2015]. Along with the approach of this paper,
we show a simpler recognition algorithm for simple-triangle graphs. To do this,
we provide a polynomial-time algorithm to solve the following problem: Given a
bipartite graph $G$ and a set $F$ of edges of $G$, find a 2-chain subgraph
cover of $G$ such that one of two chain subgraphs has no edges in $F$.


title: On model of information system for management of information flows

abstract:
  In this article are discussed some problems in developing software related to
the management of information flows. We presented the basic stages in their
development. We bold a methodology for conceptual modeling and design of
information systems of this type. In order to demonstrate the effectiveness of
the proposed model is an information system for administrative services of
graduate students in the university.


title: The enigma of the $\nu=2+\frac{3}{8}$ fractional quantum Hall effect

abstract:
  The fractional quantum Hall effect at $\nu=2+3/8$, which has been
definitively observed, is one of the last fractions for which no viable
explanation has so far been demonstrated. Our detailed study suggests that it
belongs to a new class of of exotic states described by the
Bonderson-Slingerland wave function. Its excitations are non-Abelian anyons
similar to those of the well studied Pfaffian state at 5/2, but its wave
function has a more complex structure. Using the effective edge theory, we make
predictions for various measurable quantities that should enable a confirmation
of the underlying topological order of this state.


title:
The first study of the light-travel time effect in massive LMC eclipsing
  binaries

abstract:
  Aims: New CCD observations for semidetached and detached eclipsing binaries
from the Large Magellanic Cloud were carried out using the Danish 1.54-m
telescope located at the La Silla Observatory in Chile. The selected systems
were monitored for their times of minima, which were required to be able to
study the period changes taking place in them. In addition, many new times of
minima were derived from the photometric surveys OGLE-II, OGLE-III, and MACHO.
Methods: The O-C diagrams of minima timings were analysed using the hypothesis
of the light-travel time effect, i.e. assuming the orbital motion around a
common barycenter with the distant component. Moreover, the light curves of
these systems were also analysed using the program PHOEBE, which provided the
physical parameters of the stars. Results: For the first time, in this study we
derived the relatively short periods of modulation in these systems, which
relates to third bodies. The orbital periods resulted from 3.6 to 11.3 yr and
the eccentricities were found to be up to 0.64. This is the first time that
this kind of analysis for the set of extragalactic sources has been performed.
The Wolf-Rayet system OGLE-LMC-ECL-08823 is the most mysterious one, owing to
the resultant high mass function. Another system, OGLE-LMC-ECL-19996, was found
to contain a third body with a very high mass (M3,min = 26M0). One system
(OGLE-LMC-ECL-09971) is suspicious because of its eccentricity, and another one
(OGLE-LMC-ECL-20162) shows some light curve variability, with a possible
flare-like or microlensing-like event. Conclusions: All of these results came
only from the photometric observations of the systems and can be considered as
a good starting point for future dedicated observations.


title:
Emergent gauge fields from curvature in single layers of
  transition-metal dichalcogenides

abstract:
  We analyze the electron dynamics in corrugated layers of transition-metal
dichalcogenides. Due to the strong spin-orbit coupling, the intrinsic
(Gaussian) curvature leads to an emergent gauge field associated with the Berry
connection of the spinor wave function. We discuss the gauge field created by
topological defects of the lattice, namely, tetragonal/octogonal disclinations
and edge dislocations. Ripples and topological disorder induce the same
dephasing effects as a random magnetic field, suppressing the weak localization
effects. This geometric magnetic field can be detected in a Aharonov-Bohm
interferometry experiment by measuring the local density of states in the
vicinity of corrugations.


title: Position space method for the nucleon magnetic moment in lattice QCD

abstract:
  The extraction of the magnetic form factor of the nucleon at zero momentum
transfer is usually performed by adopting a parametrization for its momentum
dependence and fitting the results obtained at finite momenta. We present a
position space method that allows us to remove the momentum prefactor in the
form factor decomposition and hence compute the magnetic form factor directly
at zero momentum without the need to assume a functional form for its momentum
dependence. The method is explored on one ensemble using $N_f=2+1+1$ Wilson
twisted mass fermions with a light quark mass corresponding to
$M_\pi\approx373\mathrm{GeV}$ and a lattice spacing of
$a\approx0.082\mathrm{fm}$. We obtain results for the isovector magnetic moment
and for the proton and neutron magnetic moments. The value we find for the
isovector magnetic moment is larger as compared to fitting the form factor at
the discrete values of the lattice momentum transfers using a dipole Ansatz,
bringing it closer to the experimental value.


title: Differential 1-forms on diffeological spaces and diffeological gluing

abstract:
  This paper aims to describe the behavior of diffeological differential
1-forms under the operation of gluing of diffeological spaces along a smooth
map. In the diffeological context, two constructions regarding diffeological
forms are available, that of the vector space \Omega^1(X) of all 1-forms, and
that of the (pseudo-)bundle \Lambda^1(X) of values of 1-forms. We describe the
behavior of the former under an arbitrary gluing of two diffeological spaces,
while for the latter, we limit ourselves to the case of gluing along a
diffeomorphism.


title: Adaptive Beaconing Approaches for Vehicular ad hoc Networks: A Survey

abstract:
  Vehicular communication requires vehicles to self-organize through the
exchange of periodic beacons. Recent analysis on beaconing indicates that the
standards for beaconing restrict the desired performance of vehicular
applications. This situation can be attributed to the quality of the available
transmission medium, persistent change in the traffic situation and the
inability of standards to cope with application requirements. To this end, this
paper is motivated by the classifications and capability evaluations of
existing adaptive beaconing approaches. To begin with, we explore the anatomy
and the performance requirements of beaconing. Then, the beaconing design is
analyzed to introduce a design-based beaconing taxonomy. A survey of the
state-of-the-art is conducted with an emphasis on the salient features of the
beaconing approaches. We also evaluate the capabilities of beaconing approaches
using several key parameters. A comparison among beaconing approaches is
presented, which is based on the architectural and implementation
characteristics. The paper concludes by discussing open challenges in the
field.


title: A subtle symmetry of Lebesgue's measure

abstract:
  We represent the Lebesgue measure on the unit interval as a boundary measure
of the Farey tree and show that this representation has a certain symmetry
related to the tree automorphism induced by Dyer's outer automorphism of the
group PGL(2,Z). Our approach gives rise to three new measures on the unit
interval which are possibly of arithmetic significance.


title: Emergent hydrodynamics in integrable quantum systems out of equilibrium

abstract:
  Understanding the general principles underlying strongly interacting quantum
states out of equilibrium is one of the most important tasks of current
theoretical physics. With experiments accessing the intricate dynamics of
many-body quantum systems, it is paramount to develop powerful methods that
encode the emergent physics. Up to now, the strong dichotomy observed between
integrable and non-integrable evolutions made an overarching theory difficult
to build, especially for transport phenomena where space-time profiles are
drastically different. We present a novel framework for studying transport in
integrable systems: hydrodynamics with infinitely-many conservation laws. This
bridges the conceptual gap between integrable and non-integrable quantum
dynamics, and gives powerful tools for accurate studies of space-time profiles.
We apply it to the description of energy transport between heat baths, and
provide a full description of the current-carrying non-equilibrium steady state
and the transition regions in a family of models including the Lieb-Liniger
model of interacting Bose gases, realized in experiments.


title: Relevant sparse codes with variational information bottleneck

abstract:
  In many applications, it is desirable to extract only the relevant aspects of
data. A principled way to do this is the information bottleneck (IB) method,
where one seeks a code that maximizes information about a 'relevance' variable,
Y, while constraining the information encoded about the original data, X.
Unfortunately however, the IB method is computationally demanding when data are
high-dimensional and/or non-gaussian. Here we propose an approximate
variational scheme for maximizing a lower bound on the IB objective, analogous
to variational EM. Using this method, we derive an IB algorithm to recover
features that are both relevant and sparse. Finally, we demonstrate how
kernelized versions of the algorithm can be used to address a broad range of
problems with non-linear relation between X and Y.


title:
Combining Recurrent and Convolutional Neural Networks for Relation
  Classification

abstract:
  This paper investigates two different neural architectures for the task of
relation classification: convolutional neural networks and recurrent neural
networks. For both models, we demonstrate the effect of different architectural
choices. We present a new context representation for convolutional neural
networks for relation classification (extended middle context). Furthermore, we
propose connectionist bi-directional recurrent neural networks and introduce
ranking loss for their optimization. Finally, we show that combining
convolutional and recurrent neural networks using a simple voting scheme is
accurate enough to improve results. Our neural models achieve state-of-the-art
results on the SemEval 2010 relation classification task.


title: Near-optimal Bayesian Active Learning with Correlated and Noisy Tests

abstract:
  We consider the Bayesian active learning and experimental design problem,
where the goal is to learn the value of some unknown target variable through a
sequence of informative, noisy tests. In contrast to prior work, we focus on
the challenging, yet practically relevant setting where test outcomes can be
conditionally dependent given the hidden target variable. Under such
assumptions, common heuristics, such as greedily performing tests that maximize
the reduction in uncertainty of the target, often perform poorly. In this
paper, we propose ECED, a novel, computationally efficient active learning
algorithm, and prove strong theoretical guarantees that hold with correlated,
noisy tests. Rather than directly optimizing the prediction error, at each
step, ECED picks the test that maximizes the gain in a surrogate objective,
which takes into account the dependencies between tests. Our analysis relies on
an information-theoretic auxiliary function to track the progress of ECED, and
utilizes adaptive submodularity to attain the near-optimal bound. We
demonstrate strong empirical performance of ECED on two problem instances,
including a Bayesian experimental design task intended to distinguish among
economic theories of how people make risky decisions, and an active preference
learning task via pairwise comparisons.