title:
Superluminous supernova 2015bn in the nebular phase: evidence for the
  engine-powered explosion of a stripped massive star

abstract:
  We present nebular-phase imaging and spectroscopy for the hydrogen-poor
superluminous supernova SN 2015bn, at redshift z=0.1136, spanning +250-400 d
after maximum light. The light curve exhibits a steepening in the decline rate
from 1.4 mag/(100 d) to 1.7 mag/(100 d), suggestive of a significant decrease
in the opacity. This change is accompanied by a transition from a blue
continuum superposed with photospheric absorption lines to a nebular spectrum
dominated by emission lines of oxygen, calcium and magnesium. There are no
obvious signatures of circumstellar interaction or large nickel mass. We show
that the spectrum at +400 d is virtually identical to a number of energetic
Type Ic supernovae such as SN 1997dq, SN 2012au, and SN 1998bw, indicating
similar core conditions and strengthening the link between `hypernovae'/long
gamma-ray bursts and superluminous supernovae. A single explosion mechanism may
unify these events that span absolute magnitudes of -22 < M_B < -17. Both the
light curve and spectrum of SN 2015bn are consistent with an engine-driven
explosion ejecting 7-30 M$_\odot$ of oxygen-dominated ejecta (for reasonable
choices in temperature and opacity). A strong and relatively narrow O II
$\lambda$7774 line, seen in a number of these energetic events but not in
normal supernovae, may point to an inner shell that is the signature of a
central engine.


title:
Towards cross-lingual distributed representations without parallel text
  trained with adversarial autoencoders

abstract:
  Current approaches to learning vector representations of text that are
compatible between different languages usually require some amount of parallel
text, aligned at word, sentence or at least document level. We hypothesize
however, that different natural languages share enough semantic structure that
it should be possible, in principle, to learn compatible vector representations
just by analyzing the monolingual distribution of words.
  In order to evaluate this hypothesis, we propose a scheme to map word vectors
trained on a source language to vectors semantically compatible with word
vectors trained on a target language using an adversarial autoencoder.
  We present preliminary qualitative results and discuss possible future
developments of this technique, such as applications to cross-lingual sentence
representations.


title:
Birational boundedness of low dimensional elliptic Calabi-Yau varieties
  with a section

abstract:
  We prove that there are finitely many families, up to isomorphism in
codimension one, of elliptic Calabi-Yau manifolds $Y\rightarrow X$ with a
rational section, provided that $\dim(Y)\leq 5$ and $Y$ is not of product-type.
As a consequence, we obtain that there are finitely many possibilities for the
Hodge diamond of such manifolds. The result follows from log birational
boundedness of klt pairs $(X, \Delta)$ with $K_X+\Delta$ numerically trivial
and not of product-type, in dimension at most $4$.


title: Room Temperature Ferroelectricity in Continuous Croconic Acid Thin Films

abstract:
  Ferroelectricity at room temperature has been demonstrated in nanometer-thin
quasi 2D croconic acid thin films, by the polarization hysteresis loop
measurements in macroscopic capacitor geometry, along with observation and
manipulation of the nanoscale domain structure by piezoresponse force
microscopy. The fabrication of continuous thin films of the hydrogen-bonded
croconic acid was achieved by the suppression of the thermal decomposition
using low evaporation temperatures in high vacuum, combined with growth
conditions far from thermal equilibrium. For nominal coverages >=20 nm, quasi
2D and polycrystalline films, with an average grain size of 50-100 nm and 3.5
nm roughness, can be obtained. Spontaneous ferroelectric domain structures of
the thin films have been observed and appear to correlate with the grain
patterns. The application of this solvent-free growth protocol may be a key to
the development of flexible organic ferroelectric thin films for electronic
applications.


title: Classifying spaces for 1-truncated compact Lie groups

abstract:
  A 1-truncated compact Lie group is any extension of a finite group by a
torus. In this note we compute the homotopy types of $Map_*(BG,BH)$,
$Map(BG,BH)$, and $Map(EG, B_GH)^G$ for compact Lie groups $G$ and $H$ with $H$
1-truncated, showing that they are computed entirely in terms of spaces of
homomorphisms from $G$ to $H$. These results generalize the well-known case
when $H$ is finite, and the case of $H$ compact abelian due to Lashof, May, and
Segal.


title:
Neural Generation of Regular Expressions from Natural Language with
  Minimal Domain Knowledge

abstract:
  This paper explores the task of translating natural language queries into
regular expressions which embody their meaning. In contrast to prior work, the
proposed neural model does not utilize domain-specific crafting, learning to
translate directly from a parallel corpus. To fully explore the potential of
neural models, we propose a methodology for collecting a large corpus of
regular expression, natural language pairs. Our resulting model achieves a
performance gain of 19.6% over previous state-of-the-art models.


title:
Bounds for the concentration functions of random sums under relaxed
  moment conditions

abstract:
  Estimates are constructed for the deviation of the concentration functions of
sums of independent random variables with finite variances from the folded
normal distribution function without any assumptions concerning the existence
of the moments of summands of higher orders. The obtained results are extended
to Poisson-binomial, binomial and Poisson random sums. Under the same
assumptions, the bounds are obtained for the approximation of the concentration
functions of mixed Poisson random sums by the corresponding limit
distributions. In particular, bounds are obtained for the accuracy of
approximation of the concentration functions of geometric, negative binomial
and Sichel random sums by the exponential, the folded variance gamma and the
folded Student distribution. Numerical estimates of all the constants involved
are written out explicitly.


title:
Homotopy type of circle graphs complexes motivated by extreme Khovanov
  homology

abstract:
  It was proven by Gonz\'alez-Meneses, Manch\'on and Silvero that the extreme
Khovanov homology of a link diagram is isomorphic to the reduced (co)homology
of the independence simplicial complex obtained from a bipartite circle graph
constructed from the diagram. In this paper we conjecture that this simplicial
complex is always homotopy equivalent to a wedge of spheres. In particular, its
homotopy type, if not contractible, would be a link invariant and it would
imply that the extreme Khovanov homology of any link diagram does not contain
torsion. We prove the conjecture in many special cases and find it convincing
to generalize it to every circle graph (intersection graph of chords in a
circle). In particular, we prove it for the families of cactus, outerplanar,
permutation and non-nested graphs. Conversely, we also give a method for
constructing a permutation graph whose independence simplicial complex is
homotopy equivalent to any given finite wedge of spheres. We also present some
combinatorial results on the homotopy type of finite simplicial complexes and a
theorem generalizing previous results by Csorba, Nagel and Reiner, Jonsson and
Barmak. We study the implications of our results to Knot Theory; more
precisely, we compute the real-extreme Khovanov homology of torus links
$T(3,q)$ and obtain examples of $H$-thick knots whose extreme Khovanov homology
groups are separated either by one or two gaps as long as desired.


title:
Proper Motion of the Leo II Dwarf Galaxy Based On Hubble Space Telescope
  Imaging

abstract:
  This article reports a measurement of the proper motion of Leo II, a dwarf
galaxy that is a likely satellite of the Milky Way, based on imaging with the
Hubble Space Telescope and Wide Field Camera 3. The measurement uses compact
background galaxies as standards of rest in both channels of the camera for two
distinct pointings of the telescope and a QSO in one channel for each pointing,
resulting in the weighted average of six measurements. The measured proper
motion in the the equatorial coordinate system is (mu_alpha, mu_delta) = (-6.9
+- 3.7, -8.7 +- 3.9) mas/century and in the Galactic coordinate system is
(mu_l, mu_b) = (6.2 +- 3.9, -9.2 +- 3.7) mas/century. The implied space
velocity with respect to the Galactic center is (Pi, Theta, Z) = (-37 +- 38,
117 +- 43, 40 +- 16) km/s or, expressed in Galactocentric radial and tangential
components, (V_r, V_tan) = (21.9 +- 1.5, 127 +- 42) km/s. The space velocity
implies that the instantaneous orbital inclination is 68 degrees, with a 95%
confidence interval of (66 deg, 80 deg). The measured motion supports the
hypothesis that Leo II, Leo IV, Leo V, Crater 2, and the globular cluster
Crater fell into the Milky Way as a group.


title: Quadrature-based Lattice Boltzmann Model for Relativistic Flows

abstract:
  A quadrature-based finite-difference lattice Boltzmann model is developed
that is suitable for simulating relativistic flows of massless particles. We
briefly review the relativistc Boltzmann equation and present our model. The
quadrature is constructed such that the stress-energy tensor is obtained as a
second order moment of the distribution function. The results obtained with our
model are presented for a particular instance of the Riemann problem (the Sod
shock tube). We show that the model is able to accurately capture the behavior
across the whole domain of relaxation times, from the hydrodynamic to the
ballistic regime. The property of the model of being extendable to arbitrarily
high orders is shown to be paramount for the recovery of the analytical result
in the ballistic regime.


title: Deep optical observations of unusual neutron star Calvera with the GTC

abstract:
  Calvera is an unusual isolated neutron star with pure thermal X-ray spectrum
typical for central compact objects in supernova remnants. On the other hand,
its rotation period and spin-down rate are typical for ordinary
rotation-powered pulsars. It was discovered and studied in X-rays and not yet
detected in other spectral domains. We present deep optical imaging of the
Calvera field obtained with the Gran Telescopio Canarias in $g'$ and $i'$
bands. Within $\approx 1^{\prime\prime}$ vicinity of Calvera, we detected two
point-like objects invisible at previous shallow observations. However,
accurate astrometry showed that none of them can be identified with the pulsar.
We put new upper limits on its optical brightness of $g' > 27.87$ and $i' >
26.84$. We also reanalyzed all available archival X-ray data on Calvera.
Comparison of the Calvera thermal emission parameters and upper limits on
optical and non-thermal X-ray emission with respective data on rotation-powered
pulsars shows that Calvera might belong to the class of ordinary middle-aged
pulsars, if we assume that its distance is in the range of $1.5-5$ kpc.


title:
Disorder-sensitive pump-probe measurements on
  Nd$_{1.83}$Ce$_{0.17}$CuO$_{4\pm\delta}$ films

abstract:
  We find an unambiguous relationship between disorder-driven features in the
temperature dependence of the resistance and the behavior, as functions of the
temperature, of the parameters necessary to describe some of the relaxation
processes in the photoinduced differential time-resolved reflectivity of three
samples of Nd$_{1.83}$Ce$_{0.17}$CuO$_{4\pm\delta}$. The latter, sharing the
same Ce content, have been fabricated and annealed ad-hoc in order to differ
only for the degree of disorder, mainly related to oxygen content and location,
and, consequently, for the temperature dependence of the resistance: two of
them present a minimum in the resistance and behave as a superconductor and as
a metal, respectively, the third behaves as an insulator. The systematic
coherence between the resistance and the relaxation parameters behaviors in
temperature for all three samples is absolutely remarkable and shows that
pump-probe measurements can be extremely sensitive to disorder as it drives the
emergence of new excitations and of the related relaxation channels as in this
paradigmatic case.


title:
Peak separation method for sub-lattice strain analysis at atomic
  resolution: Application to InAs/GaSb superlattice

abstract:
  We report on a direct measurement of cation and anion sub-lattice strain in
an InAs/GaSb type-II strained layer superlattice (T2SLs) using atomic
resolution Z-contrast imaging and advanced image processing. Atomic column
positions in InAs and GaSb are determined by separating the cation and anion
peak intensities. Analysis of the InAs/GaSb T2SLs reveals the compressive
strain in the nominal GaSb layer and tensile strain at interfaces between
constituent layers, which indicate In incorporation into the nominal GaSb layer
and the formation of GaAs like interfaces, respectively. The results are
compared with the model-dependent X-ray diffraction measurements in terms of
interfacial chemical intermixing and strain. Together, these techniques provide
a robust measurement of atomic-scale strain which is vital to determine T2SL
properties.


title: Network Topology Inference from Spectral Templates

abstract:
  We address the problem of identifying a graph structure from the observation
of signals defined on its nodes. Fundamentally, the unknown graph encodes
direct relationships between signal elements, which we aim to recover from
observable indirect relationships generated by a diffusion process on the
graph. The fresh look advocated here permeates benefits from convex
optimization and stationarity of graph signals, in order to identify the graph
shift operator (a matrix representation of the graph) given only its
eigenvectors. These spectral templates can be obtained, e.g., from the sample
covariance of independent graph signals diffused on the sought network. The
novel idea is to find a graph shift that, while being consistent with the
provided spectral information, endows the network with certain desired
properties such as sparsity. To that end we develop efficient inference
algorithms stemming from provably-tight convex relaxations of natural nonconvex
criteria, particularizing the results for two shifts: the adjacency matrix and
the normalized Laplacian. Algorithms and theoretical recovery conditions are
developed not only when the templates are perfectly known, but also when the
eigenvectors are noisy or when only a subset of them are given. Numerical tests
showcase the effectiveness of the proposed algorithms in recovering social,
brain, and amino-acid networks.


title:
The action of the mapping class group on the space of geodesic rays of a
  punctured hyperbolic surface

abstract:
  Let $\Sigma$ be a complete finite-area orientable hyperbolic surface with one
cusp, and let $\mathcal{R}$ be the space of complete geodesic rays in $\Sigma$
emanating from the puncture. Then there is a natural action of the mapping
class group of $\Sigma$ on $\mathcal{R}$. We show that this action is "almost
everywhere" wandering.


title:
The OPD Photometric Survey of Open Clusters II. robust determination of
  the fundamental parameters of 24 open clusters

abstract:
  In the second paper of the series we continue the investigation of open
cluster fundamental parameters using a robust global optimization method to fit
model isochrones to photometric data. We present optical UBVRI CCD photometry
(Johnsons-Cousins system) observations for 24 neglected open clusters, of which
14 have high quality data in the visible obtained for the first time, as a part
of our ongoing survey being carried out in the 0.6m telescope of the Pico dos
Dias Observatory in Brazil. All objects were then analyzed with a global
optimization tool developed by our group which estimates the membership
likelihood of the observed stars and fits an isochrone from which a distance,
age, reddening, total to selective extinction ratio $R_{V}$ (included in this
work as a new free parameter) and metallicity are estimated. Based on those
estimates and their associated errors we analyzed the status of each object as
real clusters or not, finding that two are likely to be asterisms. We also
identify important discrepancies between our results and previous ones obtained
in the literature which were determined using 2MASS photometry.


title: Cellular Legendrian contact homology for surfaces, part II

abstract:
  This article is a continuation of [15]. For Legendrian surfaces in $1$-jet
spaces, we prove that the Cellular DGA defined in [15] is stable tame
isomorphic to the Legendrian contact homology DGA.


title: Fr\'echet Regression for Random Objects with Euclidean Predictors

abstract:
  Increasingly, statisticians are faced with the task of analyzing complex data
that are non-Euclidean and specifically do not lie in a vector space. To
address the need for statistical methods for such data, we introduce the
concept of Fr\'echet regression. This is a general approach to regression when
responses are complex random objects in a metric space and predictors are in
$\mathcal{R}^p$, achieved by extending the classical concept of a Fr\'echet
mean to the notion of a conditional Fr\'echet mean. We develop generalized
versions of both global least squares regression and local weighted least
squares smoothing. The target quantities are appropriately defined population
versions of global and local regression for response objects in a metric space.
We derive asymptotic rates of convergence for the corresponding fitted
regressions using observed data to the population targets under suitable
regularity conditions by applying empirical process methods. For the special
case of random objects that reside in a Hilbert space, such as regression
models with vector predictors and functional data as responses, we obtain a
limit distribution. The proposed methods have broad applicability. Illustrative
examples include responses that consist of probability distributions and
correlation matrices, and we demonstrate both global and local Fr\'echet
regression for demographic and brain imaging data. Local Fr\'echet regression
is also illustrated via a simulation with response data which lie on the
sphere.


title:
Belief Space Planning Simplified: Trajectory-Optimized LQG (T-LQG)
  (Extended Report)

abstract:
  Planning under motion and observation uncertainties requires solution of a
stochastic control problem in the space of feedback policies. In this paper, we
reduce the general (n^2+n)-dimensional belief space planning problem to an
(n)-dimensional problem by obtaining a Linear Quadratic Gaussian (LQG) design
with the best nominal performance. Then, by taking the underlying trajectory of
the LQG controller as the decision variable, we pose a coupled design of
trajectory, estimator, and controller design through a Non-Linear Program (NLP)
that can be solved by a general NLP solver. We prove that under a first-order
approximation and a careful usage of the separation principle, our
approximations are valid. We give an analysis on the existing major belief
space planning methods and show that our algorithm has the lowest computational
burden. Finally, we extend our solution to contain general state and control
constraints. Our simulation results support our design.


title: Some sums over irreducible polynomials

abstract:
  We prove a number of conjectures due to Dinesh Thakur concerning sums of the
form $\sum_P h(P)$ where the sum is over monic irreducible polynomials $P$ in
$\mathbb{F}_q[T]$, the function $h$ is a rational function and the sum is
considered in the $T^{-1}$-adic topology. As an example of our results, in
$\mathbb{F}_2[T]$, the sum $\sum_P \tfrac{1}{P^k - 1}$ always converges to a
rational function, and is $0$ for $k=1$.


title:
Apparent disk-mass reduction and planetesimal formation in
  gravitationally unstable disks in Class 0/I YSOs

abstract:
  We investigate the dust structure of gravitationally unstable disks
undergoing mass accretion from the envelope envisioning the application to
Class 0/I young stellar objects (YSOs) We find that the dust disk quickly
settles into a steady state and that, compared to a disk with interstellar
medium (ISM) dust-to-gas mass ratio and micron-sized dust, the dust mass in the
steady-state decreases by a factor of 1/2 to 1/3, and the dust thermal emission
decreases by a factor of 1/3 to 1/5. The latter decrease is caused by dust
depletion and opacity decrease owing to dust growth. Our results suggest that
the masses of gravitationally unstable disks in the Class 0/I YSOs are
underestimated by a factor of 1/3 to 1/5 when calculated from the dust thermal
emission assuming an ISM dust-to-gas mass ratio and micron-sized dust opacity,
and that a larger fraction of disks in Class 0/I YSOs is gravitationally
unstable than was previously believed. We also investigate the orbital radius
$r_{\rm P}$ within which planetesimals form via coagulation of porous dust
aggregates and show that $r_{\rm P}$ becomes $\sim 20$ AU for a gravitationally
unstable disk around a solar mass star. Because $r_{\rm P}$ increases as the
gas surface density increases and a gravitationally unstable disk has a maximum
gas surface density, $r_{\rm P}\sim 20$ AU is the theoretical maximum radius.
We suggest that planetesimals formation in the Class 0/I phase is preferable to
that in the Class II phase because large gas surface density is expected and
large amount of dust is supplied by envelope-to-disk accretion.


title:
Mining Fashion Outfit Composition Using An End-to-End Deep Learning
  Approach on Set Data

abstract:
  Composing fashion outfits involves deep understanding of fashion standards
while incorporating creativity for choosing multiple fashion items (e.g.,
Jewelry, Bag, Pants, Dress). In fashion websites, popular or high-quality
fashion outfits are usually designed by fashion experts and followed by large
audiences. In this paper, we propose a machine learning system to compose
fashion outfits automatically. The core of the proposed automatic composition
system is to score fashion outfit candidates based on the appearances and
meta-data. We propose to leverage outfit popularity on fashion oriented
websites to supervise the scoring component. The scoring component is a
multi-modal multi-instance deep learning system that evaluates instance
aesthetics and set compatibility simultaneously. In order to train and evaluate
the proposed composition system, we have collected a large scale fashion outfit
dataset with 195K outfits and 368K fashion items from Polyvore. Although the
fashion outfit scoring and composition is rather challenging, we have achieved
an AUC of 85% for the scoring component, and an accuracy of 77% for a
constrained composition task.


title: Testing Assignments to Constraint Satisfaction Problems

abstract:
  For a finite relational structure A, let CSP(A) denote the CSP instances
whose constraint relations are taken from A. The resulting family of problems
CSP(A) has been considered heavily in a variety of computational contexts. In
this article, we consider this family from the perspective of property testing:
given an instance of a CSP and query access to an assignment, one wants to
decide whether the assignment satisfies the instance, or is far from so doing.
While previous works on this scenario studied concrete templates or restricted
classes of structures, this article presents comprehensive classification
theorems.
  Our first contribution is a dichotomy theorem completely characterizing the
structures A such that CSP(A) is constant-query testable: (i) If A has a
majority polymorphism and a Maltsev polymorphism, then CSP(A) is constant-query
testable with one-sided error. (ii) Else, testing CSP(A) requires a
super-constant number of queries. Let $\exists$CSP(A) denote the extension of
CSP(A) to instances which may include existentially quantified variables.
  Our second contribution is to classify all structures A in terms of the
number of queries needed to test assignments to instances of $\exists$CSP(A),
with one-sided error. More specifically, we show the following trichotomy: (i)
If A has a majority polymorphism and a Maltsev polymorphism, then
$\exists$CSP(A) is constant-query testable with one-sided error. (ii) Else, if
A has a $(k + 1)$-ary near-unanimity polymorphism for some $k \geq 2$, and no
Maltsev polymorphism then $\exists$CSP(A) is not constant-query testable (even
with two-sided error) but is sublinear-query testable with one-sided error.
(iii) Else, testing $\exists$CSP(A) with one-sided error requires a linear
number of queries.


title:
Qualitative breakdown of the non-crossing approximation for the
  symmetric one-channel Anderson impurity model at all temperatures

abstract:
  The Anderson impurity model is studied by means of the self-consistent
hybridization expansions in its non-crossing (NCA) and one-crossing (OCA)
approximations. We have found that for the one-channel spin-$1/2$ particle-hole
symmetric Anderson model, the NCA results are qualitatively wrong for any
temperature, even when the approximation gives the exact threshold exponents of
the ionic states. Actually, the NCA solution describes an overscreened Kondo
effect, because it is the same as for the two-channel infinite-$U$ single level
Anderson model. We explicitly show that the NCA is unable to distinguish
between these two very different physical systems, independently of
temperature. Using the impurity entropy as an example, we show that the low
temperature values of the NCA entropy for the symmetric case yield the limit
$S_{imp}(T=0)\rightarrow \ln\sqrt{2},$ which corresponds to the zero
temperature entropy of the overscreened Kondo model. Similar pathologies are
predicted for any other thermodynamic property. On the other hand, we have
found that the OCA approach lifts the artificial mapping between the models and
restores correct properties of the ground-state, for instance, a vanishing
entropy at low enough temperatures $S_{imp}(T=0)\rightarrow0$. Our results
indicate that the very well known NCA should be used with caution close to the
symmetric point of the Anderson model.


title:
Stability analysis for the incompressible Navier-Stokes equations with
  Navier boundary conditions

abstract:
  This paper concerns the instability and stability of the trivial steady
states of the incompressible Navier-Stokes equations with Navier-slip boundary
conditions in a slab domain in dimension two. The main results show that the
stability (or instability) of this constant equilibrium depends crucially on
whether the boundaries dissipate energy and the strengthen of the viscosity and
slip length. It is shown that in the case that when all the boundaries are
dissipative, then nonlinear asymptotic stability holds true, otherwise, there
is a sharp critical viscosity, which distinguishes the nonlinear stability from
instability.


title:
Nuclear charge radii: Density functional theory meets Bayesian neural
  networks

abstract:
  The distribution of electric charge in atomic nuclei is fundamental to our
understanding of the complex nuclear dynamics and a quintessential observable
to validate nuclear structure models. We explore a novel approach that combines
sophisticated models of nuclear structure with Bayesian neural networks (BNN)
to generate predictions for the charge radii of thousands of nuclei throughout
the nuclear chart. A class of relativistic energy density functionals is used
to provide robust predictions for nuclear charge radii. In turn, these
predictions are refined through Bayesian learning for a neural network that is
trained using residuals between theoretical predictions and the experimental
data. Although predictions obtained with density functional theory provide a
fairly good description of experiment, our results show significant improvement
(better than 40%) after BNN refinement. Moreover, these improved results for
nuclear charge radii are supplemented with theoretical error bars. We have
successfully demonstrated the ability of the BNN approach to significantly
increase the accuracy of nuclear models in the predictions of nuclear charge
radii. However, as many before us, we failed to uncover the underlying physics
behind the intriguing behavior of charge radii along the calcium isotopic
chain.


title:
Ernst formulation of axisymmetric fields in $f(R)$ gravity: applications
  to neutron stars and gravitational waves

abstract:
  The Ernst formulation of the Einstein equations is generalised to accommodate
$f(R)$ theories of gravity. It is shown that, as in general relativity, the
axisymmetric $f(R)$ field equations for a vacuum spacetime that is either
stationary or cylindrically symmetric reduce to a single, non-linear
differential equation for a complex-valued scalar function. As a worked
example, we apply the generalised Ernst equations to derive a $f(R)$
generalisation of the Zipoy-Voorhees metric, which may be used to describe the
gravitational field outside of an ellipsoidal neutron star. We also apply the
theory to investigate the phase speed of large-amplitude gravitational waves in
$f(R)$ gravity in the context of soliton-like solutions that display shock-wave
behaviour across the causal boundary.


title:
Dynamic Principal Component Analysis: Identifying the Relationship
  between Multiple Air Pollutants

abstract:
  The dynamic nature of air quality chemistry and transport makes it difficult
to identify the mixture of air pollutants for a region. In this study of air
quality in the Houston metropolitan area we apply dynamic principal component
analysis (DPCA) to a normalized multivariate time series of daily concentration
measurements of five pollutants (O3, CO, NO2, SO2, PM2.5) from January 1, 2009
through December 31, 2011 for each of the 24 hours in a day. The resulting
dynamic components are examined by hour across days for the 3 year period.
Diurnal and seasonal patterns are revealed underlining times when DPCA performs
best and two principal components (PCs) explain most variability in the
multivariate series. DPCA is shown to be superior to static principal component
analysis (PCA) in discovery of linear relations among transformed pollutant
measurements. DPCA captures the time-dependent correlation structure of the
underlying pollutants recorded at up to 34 monitoring sites in the region. In
winter mornings the first principal component (PC1) (mainly CO and NO2)
explains up to 70% of variability. Augmenting with the second principal
component (PC2) (mainly driven by SO2) the explained variability rises to 90%.
In the afternoon, O3 gains prominence in the second principal component. The
seasonal profile of PCs' contribution to variance loses its distinction in the
afternoon, yet cumulatively PC1 and PC2 still explain up to 65% of variability
in ambient air data. DPCA provides a strategy for identifying the changing air
quality profile for the region studied.


title: Stochastic Rank-1 Bandits

abstract:
  We propose stochastic rank-$1$ bandits, a class of online learning problems
where at each step a learning agent chooses a pair of row and column arms, and
receives the product of their values as a reward. The main challenge of the
problem is that the individual values of the row and column are unobserved. We
assume that these values are stochastic and drawn independently. We propose a
computationally-efficient algorithm for solving our problem, which we call
Rank1Elim. We derive a $O((K + L) (1 / \Delta) \log n)$ upper bound on its
$n$-step regret, where $K$ is the number of rows, $L$ is the number of columns,
and $\Delta$ is the minimum of the row and column gaps; under the assumption
that the mean row and column rewards are bounded away from zero. To the best of
our knowledge, we present the first bandit algorithm that finds the maximum
entry of a rank-$1$ matrix whose regret is linear in $K + L$, $1 / \Delta$, and
$\log n$. We also derive a nearly matching lower bound. Finally, we evaluate
Rank1Elim empirically on multiple problems. We observe that it leverages the
structure of our problems and can learn near-optimal solutions even if our
modeling assumptions are mildly violated.


title: Modeling Efficiency of Foreign Aid Allocation in Malawi

abstract:
  The Open Aid Malawi initiative has collected an unprecedented database that
identifies as much location-specific information as possible for each of over
2500 individual foreign aid donations to Malawi since 2003. Ensuring efficient
use and distribution of that aid is important to donors and to Malawi citizens.
However, because of individual donor goals and difficulty in tracking donor
coordination, determining presence or absence of efficient aid allocation is
difficult. We compare several Bayesian spatial generalized linear mixed models
to relate aid allocation to various economic indicators within seven donation
sectors. We find that the spatial gamma regression model best predicts current
aid allocation. Using this model, first we use inferences on coefficients to
examine whether or not there is evidence of efficient aid allocation within
each sector. Second, we use this model to determine a more efficient aid
allocation scenario and compare this scenario to the current allocation to
provide insight for future aid donations.


title: POLARBEAR-2: an instrument for CMB polarization measurements

abstract:
  POLARBEAR-2 (PB-2) is a cosmic microwave background (CMB) polarization
experiment that will be located in the Atacama highland in Chile at an altitude
of 5200 m. Its science goals are to measure the CMB polarization signals
originating from both primordial gravitational waves and weak lensing. PB-2 is
designed to measure the tensor to scalar ratio, r, with precision {\sigma}(r) <
0.01, and the sum of neutrino masses, {\Sigma}m{\nu}, with
{\sigma}({\Sigma}m{\nu}) < 90 meV. To achieve these goals, PB-2 will employ
7588 transition-edge sensor bolometers at 95 GHz and 150 GHz, which will be
operated at the base temperature of 250 mK. Science observations will begin in
2017.


title:
Towards Visual Type Theory as a Mathematical Tool and Mathematical User
  Interface

abstract:
  A visual type theory is a cognitive tool that has much in common with
language, and may be regarded as an exceptional form of spatial text adjunct. A
mathematical visual type theory, called NPM, has been under development that
can be viewed as an early-stage project in mathematical knowledge management
and mathematical user interface development. We discuss in greater detail the
notion of a visual type theory, report on progress towards a usable
mathematical visual type theory, and discuss the outlook for future work on
this project.


title: Dimensions of three types of BCH codes over GF(q)

abstract:
  BCH codes have been studied for over fifty years and widely employed in
consumer devices, communication systems, and data storage systems. However, the
dimension of BCH codes is settled only for a very small number of cases. In
this paper, we study the dimensions of BCH codes over finite fields with three
types of lengths $n$, namely $n=q^m-1$, $n=(q^m-1)/(q-1)$ and $n=q^m+1$. For
narrow-sense primitive BCH codes with designed distance $\delta$, we
investigate their dimensions for $\delta$ in the range $1\le \delta \le
q^{\lceil\frac{m}{2}\rceil+1}$. For non-narrow sense primitive BCH codes, we
provide two general formulas on their dimensions and give the dimensions
explicitly in some cases. Furthermore, we settle the minimum distances of some
primitive BCH codes. We also explore the dimensions of the BCH codes of lengths
$n=(q^m-1)/(q-1)$ and $n=q^m+1$ over finite fields.


title:
Revisiting the b1 pi and rho pi decay modes of the 1-+ light hybrid
  state with light-cone QCD sum rules

abstract:
  We study the $\rho\pi$ and $b_1\pi$ decay modes of the $1^{-+}$ light hybrid
state within the framework of light-cone QCD sum rules. We use both the tensor
current $\bar\psi\sigma_{\mu\nu}\psi$ and the derivative current
$\bar{\psi}\overleftrightarrow{D}_\mu\gamma_5\psi$ as interpolating currents to
calculate the partial decay width of the $b_1\pi$ decay mode. Comparing the sum
rules obtained by using different currents, we obtain $\Gamma(\pi_1\to b_1\pi)$
= 8--23, 32--86 and 52--151\,MeV for $m_{1^{-+}}$ = 1.6, 1.8 and 2.0\,GeV
respectively, which favour the results from the flux tube models and lattice
simulations. We also use the tensor current to study the $\rho\pi$ decay mode,
and although an extended stability criterion is needed, our results suggest a
small partial decay width.


title:
Topologically entangled Rashba-split Shockley states on the surface of
  grey arsenic

abstract:
  We discover a pair of spin-polarized surface bands on the (111) face of grey
arsenic by using angle-resolved photoemission spectroscopy (ARPES). In the
occupied side, the pair resembles typical nearly-free-electron Shockley states
observed on noble-metal surfaces. However, pump-probe ARPES reveals that the
spin-polarized pair traverses the bulk band gap and that the crossing of the
pair at $\bar\Gamma$ is topologically unavoidable. First-principles
calculations well reproduce the bands and their non-trivial topology; the
calculations also support that the surface states are of Shockley type because
they arise from a band inversion caused by crystal field. The results provide
compelling evidence that topological Shockley states are realized on As(111).


title: Hierarchical Character-Word Models for Language Identification

abstract:
  Social media messages' brevity and unconventional spelling pose a challenge
to language identification. We introduce a hierarchical model that learns
character and contextualized word-level representations for language
identification. Our method performs well against strong base- lines, and can
also reveal code-switching.


title:
Slepian Spatial-Spectral Concentration Problem on the Sphere: Analytical
  Formulation for Limited Colatitude-Longitude Spatial Region

abstract:
  In this paper, we develop an analytical formulation for the Slepian
spatial-spectral concentration problem on the sphere for a limited
colatitude-longitude spatial region on the sphere, defined as the Cartesian
product of a range of positive colatitudes and longitudes. The solution of the
Slepian problem is a set of functions that are optimally concentrated and
orthogonal within a spatial or spectral region. These properties make them
useful for applications where measurements are taken within a spatially limited
region of the sphere and/or a signal is only to be analyzed within a region of
the sphere. To support localized spectral/spatial analysis, and estimation and
sparse representation of localized data in these applications, we exploit the
expansion of spherical harmonics in the complex exponential basis to develop an
analytical formulation for the Slepian concentration problem for a limited
colatitude-longitude spatial region. We also extend the analytical formulation
for spatial regions that are comprised of a union of rotated limited
colatitude-longitude subregions. By exploiting various symmetries of the
proposed formulation, we design a computationally efficient algorithm for the
implementation of the proposed analytical formulation. Such a reduction in
computation time is demonstrated through numerical experiments. We present
illustrations of our results with the help of numerical examples and show that
the representation of a spatially concentrated signal is indeed sparse in the
Slepian basis.


title:
Segmentation and Estimation of Change-point Models: False Positive
  Control and Confidence Regions

abstract:
  To segment a sequence of independent random variables at an unknown number of
change-points, we introduce new procedures that are based on thresholding the
likelihood ratio statistic. We also study confidence regions based on the
likelihood ratio statistic for the change-points and joint confidence regions
for the change-points and the parameter values. Applications to segment array
CGH data are discussed.


title:
Joint pricing and inventory control for a stochastic inventory system
  with Brownian motion demand

abstract:
  In this paper, we consider an infinite horizon, continuous-review, stochastic
inventory system in which cumulative customers' demand is price-dependent and
is modeled as a Brownian motion. Excess demand is backlogged. The revenue is
earned by selling products and the costs are incurred by holding/shortage and
ordering, the latter consists of a fixed cost and a proportional cost. Our
objective is to simultaneously determine a pricing strategy and an inventory
control strategy to maximize the expected long-run average profit.
Specifically, the pricing strategy provides the price $p_t$ for any time
$t\geq0$ and the inventory control strategy characterizes when and how much we
need to order. We show that an $(s^*,S^*,p^*)$ policy is optimal and obtain the
equations of optimal policy parameters, where $p^*=\{p_t^*:t\geq 0\}$.
Furthermore, we find that at each time $t$, the optimal price $p_t^*$ depends
on the current inventory level $z$, and it is increasing in $[s^*,z^*]$ and is
decreasing in $[z^*,\infty)$, where $z^*$ is a negative level.


title:
Error estimates for structure-preserving discretization of the
  incompressible MHD system

abstract:
  In this paper, we carry out the error analysis for the structure-preserving
discretization of the incompressible MHD system. This system, as a coupled
system of Navier-Stokes equations and Maxwell's equations, is nonlinear. We use
its energy estimate and the underlying physical structure to facilitate the
error analysis. Under certain CFL conditions, we prove the optimal order of
convergence. To support the theoretical results, we also present numerical
tests.


title:
The Effects of Accretion Flow Dynamics on the Black Hole Shadow of
  Sagittarius A$^{*}$

abstract:
  A radiatively inefficient accretion flow (RIAF), which is commonly
characterized by its sub-Keplerian nature, is a favored accretion model for the
supermassive black hole at Galactic center, Sagittarius A$^{*}$. To investigate
the observable features of a RIAF, we compare the modeled shadow images,
visibilities, and spectra of three flow models with dynamics characterized by
(i) a Keplerian shell which is rigidly-rotating outside the innermost stable
circular orbit (ISCO) and infalling with a constant angular momentum inside
ISCO, (ii) a sub-Keplerian motion, and (iii) a free-falling motion with zero
angular momentum at infinity. At near-mm wavelengths the emission is dominated
by the flow within several Schwarzschild radii. The energy shift due to the
flow dynamics becomes important and distinguishable, suggesting that the flow
dynamics are an important model parameter for interpreting the mm/submillimeter
very long baseline interferometric observations with the forthcoming, fully
assembled Event Horizon Telescope (EHT). As an example, we demonstrate that
structural variations of Sagittarius A$^{*}$ on event horizon-scales detected
in previous EHT observations can be explained by the non-stationary dynamics of
a RIAF.


title:
Universal Simulation of Directed Systems in the abstract Tile Assembly
  Model Requires Undirectedness

abstract:
  As a mathematical model of self-assembling systems, Winfree's abstract Tile
Assembly Model (aTAM) is a remarkable platform for studying the behaviors and
powers of self-assembling systems. Capable of Turing universal computation, the
aTAM allows algorithmic self-assembly, in which the components can be designed
so that the rules governing their behaviors force them to inherently execute
prescribed algorithms as they combine. Adding to its completeness, the aTAM was
shown to also be intrinsically universal, which means that there exists a
single tile set such that for any arbitrary input aTAM system, that tile set
can be configured into a seed structure which will then cause self-assembly
using that tile set to simulate the input system, capturing its full dynamics
modulo only a scale factor. However, the universal simulator previously given
makes use of nondeterminism in terms of tile types placed in several key
locations when different assembly sequences are followed, even when simulating
a directed system, meaning one that has exactly one unique terminal assembly.
The question then became whether or not that nondeterminism is fundamentally
required. Here, we answer that in the affirmative: the class of directed
systems in the aTAM is not intrinsically universal, meaning there is no
universal simulator for directed systems which itself is always directed. This
provides insight into the role of nondeterminism in self-assembly, which is
itself a fundamentally nondeterministic process. To achieve this result we
leverage powerful results of computational complexity hierarchies, including
tight bounds on both best and worst-case complexities of decidable languages,
to design systems with precisely controllable space resources available to
embedded computations. We also develop novel techniques for designing systems
containing subsystems with disjoint, mutually exclusive computational powers.


title: Highly Efficient Compact Pose SLAM with SLAM++

abstract:
  Maximum likelihood estimation (MLE) is a well-known estimation method used in
many robotic and computer vision applications. Under Gaussian assumption, the
MLE converts to a nonlinear least squares (NLS) problem. Efficient solutions to
NLS exist and they are based on iteratively solving sparse linear systems until
convergence. In general, the existing solutions provide only an estimation of
the mean state vector, the resulting covariance being computationally too
expensive to recover. Nevertheless, in many simultaneous localisation and
mapping (SLAM) applications, knowing only the mean vector is not enough. Data
association, obtaining reduced state representations, active decisions and next
best view are only a few of the applications that require fast state covariance
recovery. Furthermore, computer vision and robotic applications are in general
performed online. In this case, the state is updated and recomputed every step
and its size is continuously growing, therefore, the estimation process may
become highly computationally demanding. This paper introduces a general
framework for incremental MLE called SLAM++, which fully benefits from the
incremental nature of the online applications, and provides efficient
estimation of both the mean and the covariance of the estimate. Based on that,
we propose a strategy for maintaining a sparse and scalable state
representation for large scale mapping, which uses information theory measures
to integrate only informative and non-redundant contributions to the state
representation. SLAM++ differs from existing implementations by performing all
the matrix operations by blocks. This led to extremely fast matrix manipulation
and arithmetic operations. Even though this paper tests SLAM++ efficiency on
SLAM problems, its applicability remains general.


title: Probing the out-of-equilibrium dynamics of two interacting atoms

abstract:
  We study the out-of-equilibrium dynamics of two interacting atoms in a
one-dimensional harmonic trap after a quench by a tightly pinned impurity atom.
We make use of an approximate variational calculation called the Lagrange-mesh
method to solve the Schr\"odinger equation as a function of inter-particle
interaction and impurity quench strength. We investigate the out-of-equilibrium
dynamics by calculating the Loschmidt echo which quantifies the irreversibility
of the system following the quench, while its probability distribution after
long times can be used to identify distinct dynamical regimes. These quantities
are related to the spectral function which describes the full dynamical
spectrum, and we show through a thorough examination of the parameter space the
existence of distinct scattering states and collective oscillations. This work
demonstrates how these dynamics are strongly dependent on the interaction
strength between the atoms and may be tuned to reach the orthogonality
catastrophe in few-body systems.


title:
Self-referenced coherent diffraction x-ray movie of Angstrom- and
  femtosecond-scale atomic motion

abstract:
  Time-resolved femtosecond x-ray diffraction patterns from laser-excited
molecular iodine are used to create a movie of intramolecular motion with time
and space resolution of $30~$fs and $0.3$ \AA . The high spatial fidelity is
due to interference between the moving excitation and the static initial charge
distribution. This x-ray interference has not been employed to image internal
motion in molecules before. The initial state is used as the local oscillator
for heterodyne amplification of the excited charge distribution to retrieve
real-space movies of atomic motion on \AA ngstrom and femtosecond scales.
Coherent vibrational motion and dispersion, dissociation, and rotational
dephasing are all clearly visible in the data, thereby demonstrating the
stunning sensitivity of heterodyne methods.


title: Majority Colourings of Digraphs

abstract:
  We prove that every digraph has a vertex 4-colouring such that for each
vertex $v$, at most half the out-neighbours of $v$ receive the same colour as
$v$. We then obtain several results related to the conjecture obtained by
replacing 4 by 3.


title: The Effect of Tides on the Population of PN from Interacting Binaries

abstract:
  We have used the tidal equations of Zahn to determine the maximum orbital
distance at which companions are brought into Roche lobe contact with their
giant primary, when the primary expands during the giant phases. This is a key
step when determining the rates of interaction between giants and their
companions. Our stellar structure calculations are presented as maximum radii
reached during the red and asymptotic giant branch (RGB and AGB, respectively)
stages of evolution for masses between 0.8 and 4.0 Mo (Z=0.001 - 0.04) and
compared with other models to gauge the uncertainty on radii deriving from
details of these calculations. We find overall tidal capture distances that are
typically 1-4 times the maximum radial extent of the giant star, where
companions are in the mass range from 1 Jupiter mass to a mass slightly smaller
than the mass of the primary. We find that only companions at initial orbital
separations between ~320 and ~630 Ro will be typically captured into a Roche
lobe-filling interaction or a common envelope on the AGB. Comparing these
limits with the period distribution for binaries that will make PN, we deduce
that in the standard scenario where all ~1-8 Mo stars make a PN, at most 2.5
per cent of all PN should have a post-common envelope central star binary, at
odds with the observational lower limit of 15-20 per cent. The observed
over-abundance of post-interaction central stars of PN cannot be easily
explained considering the uncertainties. We examine a range of explanations for
this discrepancy.


title:
LTE/LTE-A Random Access for Massive Machine-Type Communications in Smart
  Cities

abstract:
  Massive Machine-Type Communications (MTC) over cellular networks is expected
to be an integral part of wireless "Smart City" applications. The Long Term
Evolution (LTE)/LTE-Advanced (LTE-A) technology is a major candidate for
provisioning of MTC applications. However, due to the diverse characteristics
of payload size, transmission periodicity, power efficiency, and quality of
service (QoS) requirement, MTC poses huge challenges to LTE/LTE-A technologies.
In particular, efficient management of massive random access is one of the most
critical challenges. In case of massive random access attempts, the probability
of preamble collision drastically increases, thus the performance of LTE/LTE-A
random access degrades sharply. In this context, this article reviews the
current state-of-the-art proposals to control massive random access of MTC
devices in LTE/LTE-A networks. The proposals are compared in terms of five
major metrics, namely, access delay, access success rate, power efficiency, QoS
guarantee, and the effect on Human-Type Communications (HTC). To this end, we
propose a novel collision resolution random access model for massive MTC over
LTE/LTE-A. Our proposed model basically resolves the preamble collisions
instead of avoidance, and targets to manage massive and bursty access attempts.
Simulations of our proposed model show huge improvements in random access
success rate compared to the standard slotted-Aloha-based models. The new model
can also coexist with existing LTE/LTE-A Medium Access Control (MAC) protocol,
and ensure high reliability and time-efficient network access.


title: Oscillation Revisited

abstract:
  In previous work by Beer and Levi [8, 9], the authors studied the oscillation
$\Omega (f,A)$ of a function $f$ between metric spaces $\langle X,d \rangle$
and $\langle Y,\rho \rangle$ at a nonempty subset $A$ of $X$, defined so that
when $A =\{x\}$, we get $\Omega (f,\{x\}) = \omega (f,x)$, where $\omega (f,x)$
denotes the classical notion of oscillation of $f$ at the point $x \in X$. The
main purpose of this article is to formulate a general joint continuity result
for $(f,A) \mapsto \Omega (f,A)$ valid for continuous functions.


title: Streaming Applications on Heterogeneous Platforms

abstract:
  Using multiple streams can improve the overall system performance by
mitigating the data transfer overhead on heterogeneous systems. Currently, very
few cases have been streamed to demonstrate the streaming performance impact
and a systematic investigation of streaming necessity and how-to over a large
number of test cases remains a gap. In this paper, we use a total of 56
benchmarks to build a statistical view of the data transfer overhead, and give
an in-depth analysis of the impacting factors. Among the heterogeneous codes,
we identify two types of non-streamable codes and three types of streamable
codes, for which a streaming approach has been proposed. Our experimental
results on the CPU-MIC platform show that, with multiple streams, we can
improve the application performance by up 90%. Our work can serve as a generic
flow of using multiple streams on heterogeneous platforms.


title: Combinatorial Inference for Graphical Models

abstract:
  We propose a new family of combinatorial inference problems for graphical
models. Unlike classical statistical inference where the main interest is point
estimation or parameter testing, combinatorial inference aims at testing the
global structure of the underlying graph. Examples include testing the graph
connectivity, the presence of a cycle of certain size, or the maximum degree of
the graph. To begin with, we develop a unified theory for the fundamental
limits of a large family of combinatorial inference problems. We propose new
concepts including structural packing and buffer entropies to characterize how
the complexity of combinatorial graph structures impacts the corresponding
minimax lower bounds. On the other hand, we propose a family of novel and
practical structural testing algorithms to match the lower bounds. We provide
thorough numerical results on both synthetic graphical models and brain
networks to illustrate the usefulness of these proposed methods.


title: Identifying close binary central stars of PN with Kepler

abstract:
  Six planetary nebulae (PN) are known in the Kepler space telescope field of
view, three newly identified. Of the 5 central stars of PN with useful Kepler
data, one, J193110888+4324577, is a short-period, post common envelope binary
exhibiting relativistic beaming effects. A second, the central star of the
newly identified PN Pa5, has a rare O(He) spectral type and a periodic
variability consistent with an evolved companion, where the orbital axis is
almost aligned with the line of sight. The third PN, NGC~6826 has a fast
rotating central star, something that can only be achieved in a merger. Fourth,
the central star of the newly identified PN Kn61, has a PG1159 spectral type
and a mysterious semi-periodic light variability which we conjecture to be
related to the interplay of binarity with a stellar wind. Finally, the central
star of the circular PN A61 does not appear to have a photometric variability
above 2 mmag. With the possible exception of the variability of Kn61, all other
variability behaviour, whether due to binarity or not, would not easily have
been detected from the ground. We conclude, based on very low numbers, that
there may be many more close binary or close binary products to be discovered
with ultra-high precision photometry. With a larger number of high precision
photometric observations we will be able to determine how much higher than the
currently known 15 per cent, the short period binary fraction for central stars
of PN is likely to be.


title: Computational Limitations of First-Order Repressor Systems

abstract:
  Almost all current approaches for engineering modular logic components in
synthetic biology use first-order regulators, including most CRISPR/CAS, TAL,
zinc finger, and RNA interference systems. Many practitioners understand
intuitively that second and higher order binding is necessary for scalability,
and this is easy to show for single-input single-output systems. However, no
study to date has analysed whether a more complex system, utilizing e.g.
feedback or error correction, can produce scalable computation from first-order
regulators. We prove here that first order repressor systems cannot support
bistability. In the process, we introduce a function G to measure signal
quality in molecular systems, and we show that G always decreases in dynamic
feedback systems as well as static feed-forward logic cascades of first-order
repressors. As a result, first order repressors cannot build memory or signal
buffering elements. Finally, we suggest G as a potential new property for
characterization of standard biological parts.


title:
Electron structure of superheavy elements Uut, Fl and Uup ($Z$=113 to
  115)

abstract:
  We use recently developed method of accurate atomic calculations which
combines linearized single-double coupled cluster method with the configuration
interaction technique to calculate ionisation potentials, excitation energies,
static polarizabilities and valence electron densities for superheavy elements
Uut, Fl and Uup ($Z$=113 to 115) and their ions. The accuracy of the
calculations is controlled by comparing similar calculations for lighter
analogs of the superheavy elements, Tl, Pb and Bi with experiment. The role of
relativistic effects and correlations is discussed and comparison with earlier
calculations is presented.


title: Fashion Landmark Detection in the Wild

abstract:
  Visual fashion analysis has attracted many attentions in the recent years.
Previous work represented clothing regions by either bounding boxes or human
joints. This work presents fashion landmark detection or fashion alignment,
which is to predict the positions of functional key points defined on the
fashion items, such as the corners of neckline, hemline, and cuff. To encourage
future studies, we introduce a fashion landmark dataset with over 120K images,
where each image is labeled with eight landmarks. With this dataset, we study
fashion alignment by cascading multiple convolutional neural networks in three
stages. These stages gradually improve the accuracies of landmark predictions.
Extensive experiments demonstrate the effectiveness of the proposed method, as
well as its generalization ability to pose estimation. Fashion landmark is also
compared to clothing bounding boxes and human joints in two applications,
fashion attribute prediction and clothes retrieval, showing that fashion
landmark is a more discriminative representation to understand fashion images.


title:
A curvature identity on a 6-dimensional Riemannian Manifold and its
  applications

abstract:
  We derive a curvature identity that holds on any 6-dimensional Riemannian
manifold, from the Chern-Gauss-Bonnet theorem for a 6-dimensional closed
Riemannian manifold. We also introduce some applications of this curvature
identity.


title: Search for low-lying lattice QCD eigenstates in the Roper regime

abstract:
  The positive-parity nucleon spectrum is explored in $2 + 1$-flavour lattice
QCD in a search for new low-lying energy eigenstates near the energy regime of
the Roper resonance. In addition to conventional three-quark operators, we
consider novel, local five-quark meson-baryon type interpolating fields that
hold the promise to reveal new eigenstates that may have been missed in
previous analyses. Drawing on phenomenological insight, five-quark operators
based on $\sigma{N}$, $\pi{N}$ and $a_0{N}$ channels are constructed. Spectra
are produced in a high-statistics analysis on the PACS-CS dynamical gauge-field
configurations with $m_{\pi} = 411\textrm{ MeV}$ via variational analyses of
several operator combinations. Despite the introduction of qualitatively
different interpolating fields, no new states are observed in the energy regime
of the Roper resonance. This result provides further evidence that the
low-lying finite-volume scattering states are not localised, and strengthens
the interpretation of the Roper as a coupled-channel, dynamically-generated
meson-baryon resonance.


title: Analytic solutions for the approximation of $p$-Laplacian problem

abstract:
  This paper mainly investigates the analytic solutions for the approximation
of $p$-Laplacian problem. Through an approximation mechanism, we convert the
nonlinear partial differential equation with Dirichlet boundary into a sequence
of minimization problems. And a sequence of analytic minimizers can be obtained
by applying the canonical duality theory. Moreover, the nonlinear canonical
transformation gives a sequence of perfect dual maximization(minimization)
problems, and further discussion shows the global extrema for both primal and
dual problems.


title:
Dynamic structure of stock communities: A comparative study between
  stock returns and turnover rates

abstract:
  The detection of community structure in stock market is of theoretical and
practical significance for the study of financial dynamics and portfolio risk
estimation. We here study the community structures in Chinese stock markets
from the aspects of both price returns and turnover rates, by using a
combination of the PMFG and infomap methods based on a distance matrix. We find
that a few of the largest communities are composed of certain specific industry
or conceptional sectors and the correlation inside a sector is generally larger
than the correlation between different sectors. In comparison with returns, the
community structure for turnover rates is more complex and the sector effect is
relatively weaker. The financial dynamics is further studied by analyzing the
community structures over five sub-periods. Sectors like banks, real estate,
health care and New Shanghai take turns to compose a few of the largest
communities for both returns and turnover rates in different sub-periods.
Several specific sectors appear in the communities with different rank orders
for the two time series even in the same sub-period. A comparison between the
evolution of prices and turnover rates of stocks from these sectors is
conducted to better understand their differences. We find that stock prices
only had large changes around some important events while turnover rates surged
after each of these events relevant to specific sectors, which may offer a
possible explanation for the complexity of stock communities for turnover
rates.


title:
On the Completeness of Selective Unification in Concolic Testing of
  Logic Programs

abstract:
  Concolic testing is a popular dynamic validation technique that can be used
for both model checking and automatic test case generation. We have recently
introduced concolic testing in the context of logic programming. In contrast to
previous approaches, the key ingredient in this setting is a technique to
generate appropriate run-time goals by considering all possible ways an atom
can unify with the heads of some program clauses. This is called "selective"
unification. In this paper, we show that the existing algorithm is not complete
and explore different alternatives in order to have a sound and complete
algorithm for selective unification.


title: A relative $m$-cover of a Hermitian surface is a relative hemisystem

abstract:
  An $m$-cover of the Hermitian surface $H(3,q^2)$ of $PG(3,q^2)$ is a set
$\mathcal{S}$ of lines of $H(3,q^2)$ such that every point of $H(3,q^2)$ lies
on exactly $m$ lines of $\mathcal{S}$, and $0<m<q+1$. Segre (1965) proved that
if $q$ is odd, then $m=(q+1)/2$, and called such a set $\mathcal{S}$ of lines a
hemisystem. Penttila and Williford (2011) introduced the notion of a relative
hemisystem: a set of lines $\mathcal{R}$ of $H(3,q^2)$, $q$ even, disjoint from
a symplectic subgeometry $W(3,q)$ such that every point of $H(3,q^2)\setminus
W(3,q)$ lies on exactly $q/2$ elements of $\mathcal{R}$. In this paper, we
provide an analogue of Segre's result by introducing relative $m$-covers of
$H(3,q^2)$ with respect to a symplectic subgeometry and proving that $m$ must
necessarily be $q/2$.


title: Beam-Induced Damage Mechanisms and their Calculation

abstract:
  The rapid interaction of highly energetic particle beams with matter induces
dynamic responses in the impacted component. If the beam pulse is sufficiently
intense, extreme conditions can be reached, such as very high pressures,
changes of material density, phase transitions, intense stress waves, material
fragmentation and explosions. Even at lower intensities and longer time-scales,
significant effects may be induced, such as vibrations, large oscillations, and
permanent deformation of the impacted components. These lectures provide an
introduction to the mechanisms that govern the thermomechanical phenomena
induced by the interaction between particle beams and solids and to the
analytical and numerical methods that are available for assessing the response
of impacted components. An overview of the design principles of such devices is
also provided, along with descriptions of material selection guidelines and the
experimental tests that are required to validate materials and components
exposed to interactions with energetic particle beams.


title: Long-time asymptotics for the short pulse equation

abstract:
  In this paper, we analyze the long-time behavior of the solution of the
initial value problem (IVP) for the short pulse (SP) equation. As the SP
equation is a complete integrable system, which posses a Wadati-Konno-Ichikawa
(WKI)-type Lax pair, we formulate a $2\times 2$ matrix Riemann-Hilbert problem
to this IVP by using the inverse scattering method. Since the spectral variable
$k$ is the same order in the WKI-type Lax pair, we construct the solution of
this IVP parametrically in the new scale $(y,t)$, whereas the original scale
$(x,t)$ is given in terms of functions in the new scale, in terms of the
solution of this Riemann-Hilbert problem. However, by employing the nonlinear
steepest descent method of Deift and Zhou for oscillatory Riemann-Hilbert
problem, we can get the explicit leading order asymptotic of the solution of
the short pulse equation in the original scale $(x,t)$ as time $t$ goes to
infinity.


title: Dynamic portfolio strategy using clustering approach

abstract:
  The problem of portfolio optimization is one of the most important issues in
asset management. This paper proposes a new dynamic portfolio strategy based on
the time-varying structures of MST networks in Chinese stock markets, where the
market condition is further considered when using the optimal portfolios for
investment. A portfolio strategy comprises two stages: selecting the portfolios
by choosing central and peripheral stocks in the selection horizon using five
topological parameters, i.e., degree, betweenness centrality, distance on
degree criterion, distance on correlation criterion and distance on distance
criterion, then using the portfolios for investment in the investment horizon.
The optimal portfolio is chosen by comparing central and peripheral portfolios
under different combinations of market conditions in the selection and
investment horizons. Market conditions in our paper are identified by the
ratios of the number of trading days with rising index or the sum of the
amplitudes of the trading days with rising index to the total number of trading
days. We find that central portfolios outperform peripheral portfolios when the
market is under a drawup condition, or when the market is stable or drawup in
the selection horizon and is under a stable condition in the investment
horizon. We also find that the peripheral portfolios gain more than central
portfolios when the market is stable in the selection horizon and is drawdown
in the investment horizon. Empirical tests are carried out based on the optimal
portfolio strategy. Among all the possible optimal portfolio strategy based on
different parameters to select portfolios and different criteria to identify
market conditions, $65\%$ of our optimal portfolio strategies outperform the
random strategy for the Shanghai A-Share market and the proportion is $70\%$
for the Shenzhen A-Share market.


title: 2D materials and van der Waals heterostructures

abstract:
  The physics of two-dimensional (2D) materials and heterostructures based on
such crystals has been developing extremely fast. With new 2D materials, truly
2D physics has started to appear (e.g. absence of long-range order, 2D
excitons, commensurate-incommensurate transition, etc). Novel heterostructure
devices are also starting to appear - tunneling transistors, resonant tunneling
diodes, light emitting diodes, etc. Composed from individual 2D crystals, such
devices utilize the properties of those crystals to create functionalities that
are not accessible to us in other heterostructures. We review the properties of
novel 2D crystals and how their properties are used in new heterostructure
devices.


title: Mass estimates for very cold (< 8 K) gas in molecular cloud cores

abstract:
  The mass of prestellar cores is an essential ingredient to understand the
onset of star formation in the core. The low level of emission from cold dust
may keep parts of it hidden from observation. We aim to determine the fraction
of core mass in the temperature range < 8 K that can be expected for typical
low- and high-mass star formation regions. We calculate the dust temperature
within standard spherically symmetric prestellar cores for a grid of density
powerlaws in the outer core regions, core masses, and variation in the external
multi-component radiation field. The dust is assumed to be composed of
amorphous silicate and carbon, and variations of its optical properties are
discussed. As measure for the distribution of cores and clumps, we use core
mass functions derived for various environments. In view of the high densities
in very cold central regions, dust and gas temperatures are assumed to be
equal. We find that the fraction of mass with temperatures < 8 K in typical
low- and high-mass cores is < 20\%. It is possible to obtain higher fractions
of very cold gas by placing intermediate- or high-mass cores in a typical
low-mass star formation environment. We show that the mass uncertainty arising
from FIR to mm modeling of very cold dust emission is smaller than the mass
uncertainty due to the unknown dust opacities.


title:
Incorporating Emotion and Personality-Based Analysis in User-Centered
  Modelling

abstract:
  Understanding complex user behaviour under various conditions, scenarios and
journeys can be fundamental to the improvement of the user-experience for a
given system. Predictive models of user reactions, responses -- and in
particular, emotions -- can aid in the design of more intuitive and usable
systems. Building on this theme, the preliminary research presented in this
paper correlates events and interactions in an online social network against
user behaviour, focusing on personality traits. Emotional context and tone is
analysed and modelled based on varying types of sentiments that users express
in their language using the IBM Watson Developer Cloud tools. The data
collected in this study thus provides further evidence towards supporting the
hypothesis that analysing and modelling emotions, sentiments and personality
traits provides valuable insight into improving the user experience of complex
social computer systems.


title: SUSY Dark Matter in Universal and Nonuniversal Gaugino Mass Models

abstract:
  We review the phenomenology of SUSY dark matter in various versions of MSSM,
with universal and nonuniversal gaugino masses at the GUT scale. We start with
the universal case (CMSSM), where the cosmologically compatible dark matter
relic density is achieved only over some narrow regions of parameter space,
involving some fine-tuning. Moreover, most of these regions are seriously
challenged by the constraints from collider and direct dark matter detection
experiments. Then we consider some simple and predictive nonuniversal gaugino
mass models, based on SU(5) GUT. Several of these models offer viable SUSY dark
matter candidates, which are compatible with the cosmic dark matter relic
density and the above mentioned experimental constraints. They can be probed at
the present and future collider and dark matter search experiments. Finally, we
consider the nonuniversal gaugino mass model arising from anomaly mediated SUSY
breaking. In this case the cosmologically compatible dark matter relic density
requires dark matter mass of a few TeV, which puts it beyond the scope of
collider and direct dark matter detection experiments. However, it has
interesting predictions for some indirect dark matter detection experiments.


title: X-ray transforms in pseudo-Riemannian geometry

abstract:
  We study the problem of recovering a function on a pseudo-Riemannian manifold
from its integrals over all null geodesics in three geometries:
pseudo-Riemannian products of Riemannian manifolds, Minkowski spaces and tori.
We give proofs of uniqueness anc characterize non-uniqueness in different
settings. Reconstruction is sometimes possible if the signature $(n_1,n_2)$
satisfies $n_1\geq1$ and $n_2\geq2$ or vice versa and always when
$n_1,n_2\geq2$. The proofs are based on a Pestov identity adapted to null
geodesics (product manifolds) and Fourier analysis (other geometries). The
problem in a Minkowski space of any signature is a special case of recovering a
function in a Euclidean space from its integrals over all lines with any given
set of admissible directions, and we describe sets of lines for which this is
possible. Characterizing the kernel of the null geodesic ray transform on tori
reduces to solvability of certain Diophantine systems.


title:
The age-metallicity relation in the solar neighbourhood from a pilot
  sample of white dwarf-main sequence binaries

abstract:
  The age-metallicity relation (AMR) is a fundamental observational constraint
for understanding how the Galactic disc formed and evolved chemically in time.
However, there is not yet an agreement on the observational properties of the
AMR for the solar neighbourhood, primarily due to the difficulty in obtaining
accurate stellar ages for individual field stars. We have started an
observational campaign for providing the much needed observational input by
using wide white dwarf-main sequence (WDMS) binaries. White dwarfs are natural
clocks and can be used to derive accurate ages. Metallicities can be obtained
from the main sequence companions. Since the progenitors of white dwarfs and
the main sequence stars were born at the same time, WDMS binaries provide a
unique opportunity to observationally constrain in a robust way the properties
of the AMR. In this work we present the AMR derived from analysing a pilot
sample of 23 WDMS binaries and provide clear observational evidence for the
lack of correlation between age and metallicity at young and intermediate ages
(0-7 Gyrs).


title:
An assessment of orthographic similarity measures for several African
  languages

abstract:
  Natural Language Interfaces and tools such as spellcheckers and Web search in
one's own language are known to be useful in ICT-mediated communication. Most
languages in Southern Africa are under-resourced, however. Therefore, it would
be very useful if both the generic and the few language-specific NLP tools
could be reused or easily adapted across languages. This depends on the notion,
and extent, of similarity between the languages. We assess this from the angle
of orthography and corpora. Twelve versions of the Universal Declaration of
Human Rights (UDHR) are examined, showing clusters of languages, and which are
thus more or less amenable to cross-language adaptation of NLP tools, which do
not match with Guthrie zones. To examine the generalisability of these results,
we zoom in on isiZulu both quantitatively and qualitatively with four other
corpora and texts in different genres. The results show that the UDHR is a
typical text document orthographically. The results also provide insight into
usability of typical measures such as lexical diversity and genre, and that the
same statistic may mean different things in different documents. While NLTK for
Python could be used for basic analyses of text, it, and similar NLP tools,
will need considerable customization.


title:
Object Detection, Tracking, and Motion Segmentation for Object-level
  Video Segmentation

abstract:
  We present an approach for object segmentation in videos that combines
frame-level object detection with concepts from object tracking and motion
segmentation. The approach extracts temporally consistent object tubes based on
an off-the-shelf detector. Besides the class label for each tube, this provides
a location prior that is independent of motion. For the final video
segmentation, we combine this information with motion cues. The method
overcomes the typical problems of weakly supervised/unsupervised video
segmentation, such as scenes with no motion, dominant camera motion, and
objects that move as a unit. In contrast to most tracking methods, it provides
an accurate, temporally consistent segmentation of each object. We report
results on four video segmentation datasets: YouTube Objects, SegTrackv2,
egoMotion, and FBMS.


title:
Improving the energy-extraction efficiency of laser-plasma accelerator
  driven free-electron laser using transverse-gradient undulator with focusing
  optics and longitudinal tapering

abstract:
  It is reported that [Z. Huang et al., Phys. Rev. Lett. 109, 204801 (2012)],
high-gain free-electron laser (FEL) can be generated by transverse-dispersed
electron beams from laser-plasma accelerators (LPAs) using transverse-gradient
undulator (TGU) assuming an ideal constant dispersion function without focusing
optics. The constant dispersion function keeps electrons beyond the resonant
energy bandwidth still being on resonant with the FEL radiation. Instead, in
this paper, the case with focusing optics in an LPA-driven FEL using TGU is
numerically studied, in which the dispersion function should be monotonously
decreasing along the undulator. Even though the FEL resonance is not always
satisfied for off-energy electrons in this case, through subtly optimizing the
initial dispersion and focusing parameters, it is feasible to achieve a similar
radiation power to the case assuming an ideal constant dispersion function
without focusing optics, and meanwhile, to attain a good transverse coherence.
Moreover, higher radiation power could be expected if longitudinally tapering,
transverse-gradient variation in different sections are systematically
conducted, which is demonstrated with intense global multiparameters
optimizations based on GENESIS simulation.


title: Creating arbitrary quantum vibrational states in a carbon nanotube

abstract:
  We theoretically study the creation of single- and multi-phonon Fock states
and arbitrary superpositions of quantum phonon states in a nanomechanical
carbon nanotube (CNT) resonator. In our model, a doubly clamped CNT resonator
is initialized in the ground state and a single electron is trapped in a
quantum dot which is formed by a electric gate potential and brought into the
magnetic field of a micro-magnet. The preparation of arbitrary quantum phonon
states is based on the coupling between the mechanical motion of the CNT and
the electron spin which acts as a non-linearity. We assume that electrical
driving pulses with different frequencies are applied on the system. The
quantum information is transferred from the spin qubit to the mechanical motion
by the spin-phonon coupling and the electron spin qubit can be reset by the
single-electron spin resonance. We describe Wigner tomography which can be
applied at the end to obtain the phase information of the prepared phonon
states.


title: Variational Bayes with Synthetic Likelihood

abstract:
  Synthetic likelihood is an attractive approach to likelihood-free inference
when an approximately Gaussian summary statistic for the data, informative for
inference about the parameters, is available. The synthetic likelihood method
derives an approximate likelihood function from a plug-in normal density
estimate for the summary statistic, with plug-in mean and covariance matrix
obtained by Monte Carlo simulation from the model. In this article, we develop
alternatives to Markov chain Monte Carlo implementations of Bayesian synthetic
likelihoods with reduced computational overheads. Our approach uses stochastic
gradient variational inference methods for posterior approximation in the
synthetic likelihood context, employing unbiased estimates of the log
likelihood. We compare the new method with a related likelihood free
variational inference technique in the literature, while at the same time
improving the implementation of that approach in a number of ways. These new
algorithms are feasible to implement in situations which are challenging for
conventional approximate Bayesian computation (ABC) methods, in terms of the
dimensionality of the parameter and summary statistic.


title: Optimal routing in two-queue polling systems

abstract:
  We consider a polling system with two queues, exhaustive service, no
switch-over times and exponential service times. The waiting cost depends on
the position of the queue relative to the server: It costs a customer c per
time unit to wait in the busy queue (where the server is) and d per time unit
in the idle queue (where no server is). Customers arrive according to a Poisson
process. We study the control problem of how arrivals should be routed to the
two queues in order to minimize expected waiting costs and characterize
individually and socially optimal routing policies under three scenarios of
available information at decision epochs: no, partial and complete information.
In the complete information case, we develop a new iterative algorithm to
determine individually optimal policies, and show that such policies can be
described by a switching curve. We conjecture that a linear switching curve is
socially optimal, and prove that this policy is indeed optimal for the fluid
version of the two-queue polling system.


title:
Junction of three off-critical quantum Ising chains and two-channel
  Kondo effect in a superconductor

abstract:
  We show that a junction of three off-critical quantum Ising chains can be
regarded as a quantum spin chain realization of the two-channel spin-1/2
overscreened Kondo effect with two superconducting leads. We prove that, as
long as the Kondo temperature is larger than the superconducting gap, the
equivalent Kondo model flows towards the 2 channel Kondo fixed point. We argue
that our system provides the first controlled realization of 2 channel Kondo
effect with superconducting leads. This, besides its the theoretical interest,
is of importance for potential applications to a number of context, including
the analysis of the quantum entanglement properties of a Kondo system.


title:
Holographic entanglement entropy close to crossover/phase transition in
  strongly coupled systems

abstract:
  We investigate the behavior of entanglement entropy in the holographic QCD
model proposed by Gubser et al. By choosing suitable parameters of the scalar
self-interaction potential, this model can exhibit various types of phase
structures: crossover, first order and second order phase transitions. We use
entanglement entropy to probe the crossover/phase transition, and find that it
drops quickly/suddenly when the temperature approaches the critical point which
can be seen as a signal of confinement. Moreover, the critical behavior of the
entanglement entropy suggests that we may use it to characterize the
corresponding phase structures.


title: Ranking Competitors Using Degree-Neutralized Random Walks

abstract:
  Competition is ubiquitous in many complex biological, social, and
technological systems, playing an integral role in the evolutionary dynamics of
the systems. It is often useful to determine the dominance hierarchy or the
rankings of the components of the system that compete for survival and success
based on the outcomes of the competitions between them. Here we propose a
ranking method based on the random walk on the network representing the
competitors as nodes and competitions as directed edges with asymmetric
weights. We use the edge weights and node degrees to define the gradient on
each edge that guides the random walker towards the weaker (or the stronger)
node, which enables us to interpret the steady-state occupancy as the measure
of the node's weakness (or strength) that is free of unwarranted degree-induced
bias. We apply our method to two real-world competition networks and explore
the issues of ranking stabilization and prediction accuracy, finding that our
method outperforms other methods including the baseline win--loss differential
method in sparse networks.


title: The Venus Hypothesis

abstract:
  Current models indicate that Venus may have been habitable. Complex life may
have evolved on the highly irradiated Venus, and transferred to Earth on
asteroids. This model fits the pattern of pulses of highly developed life
appearing, diversifying and going extinct with astonishing rapidity through the
Cambrian and Ordovician periods, and also explains the extraordinary genetic
variety which appeared over this period.


title:
3D Human Pose Estimation Using Convolutional Neural Networks with 2D
  Pose Information

abstract:
  While there has been a success in 2D human pose estimation with convolutional
neural networks (CNNs), 3D human pose estimation has not been thoroughly
studied. In this paper, we tackle the 3D human pose estimation task with
end-to-end learning using CNNs. Relative 3D positions between one joint and the
other joints are learned via CNNs. The proposed method improves the performance
of CNN with two novel ideas. First, we added 2D pose information to estimate a
3D pose from an image by concatenating 2D pose estimation result with the
features from an image. Second, we have found that more accurate 3D poses are
obtained by combining information on relative positions with respect to
multiple joints, instead of just one root joint. Experimental results show that
the proposed method achieves comparable performance to the state-of-the-art
methods on Human 3.6m dataset.


title:
Hong-Ou-Mandel Interference between Two Deterministic Collective
  Excitations in an Atomic Ensemble

abstract:
  We demonstrate deterministic generation of two distinct collective
excitations in one atomic ensemble, and we realize the Hong-Ou-Mandel
interference between them. Using Rydberg blockade we create single collective
excitations in two different Zeeman levels, and we use stimulated Raman
transitions to perform a beam-splitter operation between the excited atomic
modes. By converting the atomic excitations into photons, the two-excitation
interference is measured by photon coincidence detection with a visibility of
0.89(6). The Hong-Ou-Mandel interference witnesses an entangled NOON state of
the collective atomic excitations, and we demonstrate its two times enhanced
sensitivity to a magnetic field compared with a single excitation. Our work
implements a minimal instance of Boson sampling and paves the way for further
multi-mode and multi-excitation studies with collective excitations of atomic
ensembles.


title:
Fractional-compact numerical algorithms for Riesz spatial fractional
  reaction-dispersion equations

abstract:
  It is well known that using high-order numerical algorithms to solve
fractional differential equations leads to almost the same computational cost
with low-order ones but the accuracy (or convergence order) is greatly
improved, due to the nonlocal properties of fractional operators. Therefore,
developing some high-order numerical approximation formulas for fractional
derivatives play a more important role in numerically solving fractional
differential equations. This paper focuses on constructing (generalized)
high-order fractional-compact numerical approximation formulas for Riesz
derivatives. Then we apply the developed formulas to the one- and two-dimension
Riesz spatial fractional reaction-dispersion equations. The stability and
convergence of the derived numerical algorithms are strictly studied by using
the energy analysis method. Finally, numerical simulations are given to
demonstrate the efficiency and convergence orders of the presented numerical
algorithms.


title:
Lower Bounds for On-line Interval Coloring with Vector and Cardinality
  Constraints

abstract:
  We propose two strategies for Presenter in the on-line interval graph
coloring games. Specifically, we consider a setting in which each interval is
associated with a $d$-dimensional vector of weights and the coloring needs to
satisfy the $d$-dimensional bandwidth constraint, and the $k$-cardinality
constraint. Such a variant was first introduced by Epstein and Levy and it is a
natural model for resource-aware task scheduling with $d$ different shared
resources where at most $k$ tasks can be scheduled simultaneously on a single
machine.
  The first strategy forces any on-line interval coloring algorithm to use at
least $(5m-3)\frac{d}{\log d + 3}$ different colors on an $m(\frac{d}{k} +
\log{d} + 3)$-colorable set of intervals. The second strategy forces any
on-line interval coloring algorithm to use at least
$\lfloor\frac{5m}{2}\rfloor\frac{d}{\log d + 3}$ different colors on an
$m(\frac{d}{k} + \log{d} + 3)$-colorable set of unit intervals.


title: Beam Loss Monitors at LHC

abstract:
  One of the main functions of the LHC beam loss measurement system is the
protection of equipment against damage caused by impacting particles creating
secondary showers and their energy dissipation in the matter. Reliability
requirements are scaled according to the acceptable consequences and the
frequency of particle impact events on equipment. Increasing reliability often
leads to more complex systems. The downside of complexity is a reduction of
availability; therefore, an optimum has to be found for these conflicting
requirements. A detailed review of selected concepts and solutions for the LHC
system will be given to show approaches used in various parts of the system
from the sensors, signal processing, and software implementations to the
requirements for operation and documentation.


title: The classical theory of calculus of variations for generalized functions

abstract:
  We present an extension of the classical theory of calculus of variations to
generalized functions. The framework is the category of generalized smooth
functions, which includes Schwartz distributions while sharing many nonlinear
properties with ordinary smooth functions. We prove full connections between
extremals and Euler-Lagrange equations, classical necessary and sufficient
conditions to have a minimizer, the necessary Legendre condition, Jacobi's
theorem on conjugate points and Noether's theorem. We close with an application
to low regularity Riemannian geometry.


title:
On Hodges' Superefficiency and Merits of Oracle Property in Model
  Selection

abstract:
  The oracle property of model selection procedures has attracted a large
volume of favorable publications in the literature, but also faced criticisms
of being ineffective and misleading in applications. In this paper, we
introduce a class of estimators that can easily produce model selection
procedures possessing the oracle property and discuss the merits of the oracle
property by analyzing the performance of such estimators in finite sample size
theoretically.
  Specifically, we propose a new type of Hodges' estimators capable of reducing
the asymptotic variance of any given estimator over a multi-dimensional
subspace of the parameter space, which can easily produce model selection
procedures with the oracle and some other desired properties. This new type of
oracle estimators, however, perform poorly at some values of the parameters for
estimation, and there is no convincing reason to declare that oracle estimators
are better than the traditional estimators such as the MLE and LSE.
Consequently, the merits of the oracle property for model selection as claimed
in the literature are probably grossly overstated, and the criticisms of the
oracle property are justifiable.


title:
Resonant driving of a single photon emitter embedded in a mechanical
  oscillator

abstract:
  Coupling a microscopic mechanical resonator to a nano-scale quantum system
enables control of the mechanical resonator via the quantum system, and vice
versa. The coupling is usually achieved through functionalization of the
mechanical resonator but this results in additional mass and dissipation
channels. An alternative is an intrinsic coupling based on strain. We employ
here a monolithic semiconductor system. The nano-scale quantum system is a
quantum dot; the mechanical resonator a microscopic trumpet which
simultaneously optimizes the mechanical and photonic properties. The quantum
dot transition is driven resonantly. Via the resonance fluorescence, we observe
mechanical Brownian motion even at 4K, and demonstrate a coupling to mechanical
modes of different types. We identify a mechanical mode with a cooperativity
larger than one. We show analytically that the Heisenberg limit on displacement
measurement can be reached with an embedded two-level system in the case of a
transform-limited optical emitter with perfect photon detection. We argue that
operation close to the Heisenberg limit is achievable with state-of-the-art
quantum dot devices.


title:
Rough differential equations containing path-dependent bounded variation
  terms

abstract:
  We consider rough differential equations whose coefficients contain
path-dependent bounded variation terms and prove the existence of solutions.
These equations include classical path-dependent SDEs containing running
maximum processes and normal reflection terms. We also prove a continuity
property of solution mappings at smooth rough paths which is useful to
determine the topological support of the solution processes.


title: Hierarchy of multipartite nonlocality in the nonsignaling scenario

abstract:
  We propose a hierarchy of Bell-type inequalities for arbitrary $n$-partite
systems that identify the different degrees of nonlocality ranging from
standard to genuine multipartite nonlocality. After introducing the definition
of nonsignaling $m$-locality, we show that the observed joint probabilities in
any nonsignaling $m$-local realistic models should satisfy the $(m-1)$-th
Bell-type inequality. When $m=2$ the corresponding inequality reduces to the
one shown in [Phys. Rev. Lett. 112, 140404 (2014)] whose violation indicates
genuine multipartite nonlocality, and when $m=n$ the corresponding inequality
is just Hardy's inequality whose violation indicates standard multipartite
nonlocality. Furthermore, several examples are provided to demonstrate their
hierarchy of multipartite nonlocality.


title:
Some remarks on rigid sheaves, helices and exceptional vector bundles on
  Fano varieties over arbitrary fields

abstract:
  In this paper we study the connection between rigid sheaves and
separable-exceptional objects on Fano varieties over arbitrary fields. We give
criteria for a rigid vector bundle on a Fano variety to be the direct sum of
separable-exceptional bundles and for a separable-exceptional vector bundle to
be part of a full separable-exceptional collection.


title:
Measurement of $W^+W^-$ production in association with one jet in
  proton--proton collisions at $\sqrt{s} =8$ TeV with the ATLAS detector

abstract:
  The production of $W$ boson pairs in association with one jet in $pp$
collisions at $\sqrt{s} = 8$ TeV is studied using data corresponding to an
integrated luminosity of 20.3 fb$^{-1}$ collected by the ATLAS detector during
2012 at the CERN Large Hadron Collider. The cross section is measured in a
fiducial phase-space region defined by the presence of exactly one electron and
one muon, missing transverse momentum and exactly one jet with a transverse
momentum above 25 GeV and a pseudorapidity of $|\eta|<4.5$. The leptons are
required to have opposite electric charge and to pass transverse momentum and
pseudorapidity requirements. The fiducial cross section is found to be
$\sigma^{\mathrm{fid,1\textrm{-}jet}}_{WW}=136\pm6($stat$)\pm14($syst$)\pm3($lumi$)$
fb. In combination with a previous measurement restricted to leptonic final
states with no associated jets, the fiducial cross section of $WW$ production
with zero or one jet is measured to be
$\sigma^{\mathrm{fid,}\leq\mathrm{1\textrm{-}jet}}_{WW}=511\pm9($stat$)\pm26($syst$)\pm10($lumi$)$
fb. The ratio of fiducial cross sections in final states with one and zero jets
is determined to be $0.36\pm0.05$. Finally, a total cross section extrapolated
from the fiducial measurement of $WW$ production with zero or one associated
jet is reported. The measurements are compared to theoretical predictions and
found in good agreement.