title:
MTS Sketch for Accurate Estimation of Set-Expression Cardinalities from
  Small Samples

abstract:
  Sketch-based streaming algorithms allow efficient processing of big data.
These algorithms use small fixed-size storage to store a summary ("sketch") of
the input data, and use probabilistic algorithms to estimate the desired
quantity. However, in many real-world applications it is impractical to collect
and process the entire data stream, the common practice is thus to sample and
process only a small part of it. While sampling is crucial for handling massive
data sets, it may reduce accuracy. In this paper we present a new framework
that can accurately estimate the cardinality of any set expression between any
number of streams using only a small sample of each stream. The proposed
framework consists of a new sketch, called Maximal-Term with Subsample (MTS),
and a family of algorithms that use this sketch. An example of a possible query
that can be efficiently answered using the proposed sketch is, How many
distinct tuples appear in tables $T_1$ and $T_2$, but not in $T_3$? The
algorithms presented in this paper answer such queries accurately, processing
only a small sample of the tuples in each table and using a constant amount of
memory. Such estimations are useful for the optimization of queries over very
large database systems. We show that all our algorithms are unbiased, and we
analyze their asymptotic variance.


title:
Constraining in-medium heavy-quark energy-loss mechanisms via angular
  correlations between heavy and light mesons

abstract:
  Two-particle correlations obtained from parton showers that pass the hot and
dense medium of the quark gluon plasma (QGP) can be used as an alternative
observable, in addition to the combination of the nuclear modification factor
$R_{AA}$ and the elliptic flow $v_2$, to study the mechanisms of in-medium
heavy quark energy-loss. In particular, angular correlations represent a
promising tool to distinguish between energy loss due to collisional and
radiative interactions of jet and medium particles. To this end, parton
cascades were created in Monte-Carlo simulations, where individual particles
can undergo both parton splitting as well as an effective jet-medium
interaction. A first model simulates the effects of induced radiations on
parton cascades. Its consequences on angular correlations of partons within
jets were studied in detail, with particular focus on angular broadening. The
results can be compared to a second model that effectively describes elastic
scatterings of jet and medium particles.


title: Neuro-Symbolic Program Synthesis

abstract:
  Recent years have seen the proposal of a number of neural architectures for
the problem of Program Induction. Given a set of input-output examples, these
architectures are able to learn mappings that generalize to new test inputs.
While achieving impressive results, these approaches have a number of important
limitations: (a) they are computationally expensive and hard to train, (b) a
model has to be trained for each task (program) separately, and (c) it is hard
to interpret or verify the correctness of the learnt mapping (as it is defined
by a neural network). In this paper, we propose a novel technique,
Neuro-Symbolic Program Synthesis, to overcome the above-mentioned problems.
Once trained, our approach can automatically construct computer programs in a
domain-specific language that are consistent with a set of input-output
examples provided at test time. Our method is based on two novel neural
modules. The first module, called the cross correlation I/O network, given a
set of input-output examples, produces a continuous representation of the set
of I/O examples. The second module, the Recursive-Reverse-Recursive Neural
Network (R3NN), given the continuous representation of the examples,
synthesizes a program by incrementally expanding partial programs. We
demonstrate the effectiveness of our approach by applying it to the rich and
complex domain of regular expression based string transformations. Experiments
show that the R3NN model is not only able to construct programs from new
input-output examples, but it is also able to construct new programs for tasks
that it had never observed before during training.


title:
A Comparison of the Triangle Algorithm and SMO for Solving the Hard
  Margin Problem

abstract:
  In this article we consider the problem of testing, for two finite sets of
points in the Euclidean space, if their convex hulls are disjoint and computing
an optimal supporting hyperplane if so. This is a fundamental problem of
classification in machine learning known as the hard-margin SVM. The problem
can be formulated as a quadratic programming problem. The SMO algorithm is the
current state of art algorithm for solving it, but it does not answer the
question of separability. An alternative to solving both problems is the
Triangle Algorithm, a geometrically inspired algorithm, initially described for
the convex hull membership problem, a fundamental problem in linear
programming. First, we describe the experimental performance of the Triangle
Algorithm for testing the intersection of two convex hulls. Next, we compare
the performance of Triangle Algorithm with SMO for finding the optimal
supporting hyperplane. Based on experimental results ranging up to 5000 points
in each set in dimensions up to 10000, the Triangle Algorithm outperforms SMO.


title: Groups and polytopes

abstract:
  In a series of papers the authors associated to an $L^2$-acyclic group
$\Gamma$ an invariant $\mathcal{P}(\Gamma)$ that is a formal difference of
polytopes in the vector space $H_1(\Gamma;\Bbb{R})$. This invariant is in
particular defined for most 3-manifold groups, for most 2-generator 1-relator
groups and for all free-by-cyclic groups. In most of the above cases the
invariant can be viewed as an actual polytope.
  In this survey paper we will recall the definition of the polytope invariant
$\mathcal{P}(\Gamma)$ and we state some of the main properties. We conclude
with a list of open problems.


title: Hidden Weyl Points in Centrosymmetric Paramagnetic Metals

abstract:
  The transition metal dipnictides TaAs2 , TaSb2 , NbAs2 and NbSb2 have
recently sparked interest for exhibiting giant magnetoresistance. While the
exact nature of magnetoresistance in these materials is still under active
investigation, there are experimental results indicating anisotropic negative
magnetoresistance. We study the effect of magnetic field on the band structure
topology of these materials by applying a Zeeman splitting. In the absence of
magnetic field, we find that the materials are weak topological insulators,
which is in agreement with previous studies. When the magnetic field is
applied, we find that type-II Weyl points form. This result is found first from
a symmetry argument, and then numerically for a k.p model of TaAs2 and a
tight-binding model of NbSb2. This effect can be of help in search for an
explanation of the anomalous magnetoresistance in these materials.


title: Raymond and instantons: some recollections and the use of ADHM

abstract:
  After the discovery of the BRST identities in 1974 Raymond spent some two
years mostly on instantons. In those years we had a small group at the Centre
Physique Th\'eorique in Marseille discussing the physics and mathematics of
instantons.
  The upshot of our discussions can be found in a set of lectures given by
Raymond in Erice in 1977 and a year later in a Physics Reports volume. I
present some recollections of that period; mostly how we were influenced by the
twistor approach. I discuss the Atiyah-Drinfeld-Hitchin-Manin (ADHM) method to
obtain instantons ("calorons") in thermal QCD following earlier work. The
building blocks are a prepotential and a gauge invariant propagator.
  Then I will give surprisingly simple results in terms of these building
blocks for the one loop vacuum response to a change in caloron parameters and
some physical consequences for the effective action, in particular screening
properties.


title: Spherically Symmetric Random Permutations

abstract:
  We consider random permutations which are spherically symmetric with respect
to a metric on the symmetric group $S_n$ and are consistent as $n$ varies. The
extreme infinitely spherically symmetric permutation-valued processes are
identified for the Hamming, Kendall-tau and Caley metrics. The proofs in all
three cases are based on a unified approach through stochastic monotonicity.


title: Hyperplane arrangements and tensor product invariants

abstract:
  In the first part of this paper, we consider, in the context of an arbitrary
hyperplane arrangement, the map between compactly supported cohomology to the
usual cohomology of a local system. A formula (i.e., an explicit algebraic de
Rham representative) for a generalized version of this map is obtained.
  These results are applied in the second part to invariant theory: Schechtman
and Varchenko connect invariant theoretic objects to the cohomology of local
systems on complements of hyperplane arrangements. The first part of this paper
is then used, following and completing arguments of Looijenga, to determine the
image of invariants in cohomology. In suitable cases (e.g., corresponding to
positive integral levels), the space of invariants is shown to acquire a mixed
Hodge structure over a cyclotomic field. We investigate the Hodge filtration on
the space of invariants, and characterize the subspace of conformal blocks in
Hodge theoretic terms.


title:
Helicity coherence in binary neutron star mergers and non-linear
  feedback

abstract:
  Neutrino flavor conversion studies based on astrophysical environments
usually implement neutrino mixings, neutrino interactions with matter and
neutrino self-interactions. In anisotropic media, the most general mean-field
treatment includes neutrino mass contributions as well, that introduce a
coupling between neutrinos and antineutrinos termed helicity or spin coherence.
We discuss resonance conditions for helicity coherence for Dirac and Majorana
neutrinos. We explore the role of these mean-field contributions on flavor
evolution in the context of a binary neutron star merger remnant. We find that
resonance conditions can be satisfied in neutron star merger scenarios while
adiabaticity is not sufficient for efficient flavor conversion. We analyse our
numerical findings by discussing general conditions to have multiple MSW-like
resonances, in presence of non-linear feedback, in astrophysical environments.


title:
Deeper H.E.S.S. observations of Vela Junior (RX J0852.0$-$4622):
  Morphology studies and resolved spectroscopy

abstract:
  Aims. We study gamma-ray emission from the shell-type supernova remnant (SNR)
RX J0852.0$-$4622 to better characterize its spectral properties and its
distribution over the SNR.
  Methods. The analysis of an extended High Energy Spectroscopic System
(H.E.S.S.) data set at very high energies (E > 100 GeV) permits detailed
studies, as well as spatially resolved spectroscopy, of the morphology and
spectrum of the whole RX J0852.0$-$4622 region. The H.E.S.S. data are combined
with archival data from other wavebands and interpreted in the framework of
leptonic and hadronic models. The joint Fermi-LAT-H.E.S.S. spectrum allows the
direct determination of the spectral characteristics of the parent particle
population in leptonic and hadronic scenarios using only GeV-TeV data.
  Results. An updated analysis of the H.E.S.S. data shows that the spectrum of
the entire SNR connects smoothly to the high-energy spectrum measured by
Fermi-LAT. The increased data set makes it possible to demonstrate that the
H.E.S.S. spectrum deviates significantly from a power law and is well described
by both a curved power law and a power law with an exponential cutoff at an
energy of $E_\mathrm{cut} = (6.7 \pm 1.2_\mathrm{stat} \pm 1.2_\mathrm{syst})$
TeV. The joint Fermi-LAT-H.E.S.S. spectrum allows the unambiguous
identification of the spectral shape as a power law with an exponential cutoff.
No significant evidence is found for a variation of the spectral parameters
across the SNR, suggesting similar conditions of particle acceleration across
the remnant. A simple modeling using one particle population to model the SNR
emission demonstrates that both leptonic and hadronic emission scenarios remain
plausible. It is also shown that at least a part of the shell emission is
likely due to the presence of a pulsar wind nebula around PSR J0855$-$4644.


title: Geometry of bisections of elliptic surfaces and Zariski $N$-plets II

abstract:
  In this article, we continue to study the geometry of bisections of certain
rational elliptic surfaces. As an application, we give examples of Zariski N +
1-plets of degree 2N + 4 whose irreducible components are an irreducible
quartic curve with 2 nodes and N smooth conics. Furthermore, by considering the
case of N = 2 and combining with known results, a new Zariski 5-plet for
reduced plane curves of degree 8 is given.


title:
On the Approximate Analysis of Energy Detection over n*Rayleigh Fading
  Channels through Cooperative Spectrum Sensing

abstract:
  In this letter, we consider the problem of energy detection of unknown
signals in an intervehicular communication (IVC) system over n*Rayleigh fading
channels (also known as cascaded Rayleigh). Novel tight approximations for the
probability of detection are derived for the no-diversity and the maximum ratio
combining (MRC)) diversity schemes. Moreover, we investigate the system
performance when cooperative spectrum sensing (CSS) is considered with and
without imperfect reporting channels. The analytical results show that the
detection reliability is decreased as the fading severity parameter n increases
but reliability is substantially improved when CSS employs MRC schemes.


title: Marciani Normal Form of context-free grammars

abstract:
  In this paper, we prove the semidecidability of the problem of saying whether
or not a context-free grammar generates a regular language. We introduce the
notion of context-free grammar in Marciani Normal Form. We prove that a
context-free grammar in Marciani Normal Form always generates a regular
language.


title: Latent Attention For If-Then Program Synthesis

abstract:
  Automatic translation from natural language descriptions into programs is a
longstanding challenging problem. In this work, we consider a simple yet
important sub-problem: translation from textual descriptions to If-Then
programs. We devise a novel neural network architecture for this task which we
train end-to-end. Specifically, we introduce Latent Attention, which computes
multiplicative weights for the words in the description in a two-stage process
with the goal of better leveraging the natural language structures that
indicate the relevant parts for predicting program elements. Our architecture
reduces the error rate by 28.57% compared to prior art. We also propose a
one-shot learning scenario of If-Then program synthesis and simulate it with
our existing dataset. We demonstrate a variation on the training procedure for
this scenario that outperforms the original procedure, significantly closing
the gap to the model trained with all data.


title: Truth Discovery with Memory Network

abstract:
  Truth discovery is to resolve conflicts and find the truth from
multiple-source statements. Conventional methods mostly research based on the
mutual effect between the reliability of sources and the credibility of
statements, however, pay no attention to the mutual effect among the
credibility of statements about the same object. We propose memory network
based models to incorporate these two ideas to do the truth discovery. We use
feedforward memory network and feedback memory network to learn the
representation of the credibility of statements which are about the same
object. Specially, we adopt memory mechanism to learn source reliability and
use it through truth prediction. During learning models, we use multiple types
of data (categorical data and continuous data) by assigning different weights
automatically in the loss function based on their own effect on truth discovery
prediction. The experiment results show that the memory network based models
much outperform the state-of-the-art method and other baseline methods.


title: Please Lower Small Cell Antenna Heights in 5G

abstract:
  In this paper, we present a new and significant theoretical discovery. If the
absolute height difference between base station (BS) antenna and user equipment
(UE) antenna is larger than zero, then the network capacity performance in
terms of the area spectral efficiency (ASE) will continuously decrease as the
BS density increases for ultra-dense (UD) small cell networks (SCNs). This
performance behavior has a tremendous impact on the deployment of UD SCNs in
the 5th-generation (5G) era. Network operators may invest large amounts of
money in deploying more network infrastructure to only obtain an even worse
network performance. Our study results reveal that it is a must to lower the
SCN BS antenna height to the UE antenna height to fully achieve the capacity
gains of UD SCNs in 5G. However, this requires a revolutionized approach of BS
architecture and deployment, which is explored in this paper too.


title:
Signals for Lorentz and CPT Violation in Atomic Spectroscopy Experiments
  and Other Systems

abstract:
  The prospects of studying nonminimal operators for Lorentz violation using
spectroscopy experiments with light atoms and muon spin-precession experiments
are presented. Possible improvements on bounds on minimal and nonminimal
operators for Lorentz violation are discussed.


title: Symmetry Energy III: Isovector Skins

abstract:
  Isoscalar density is a sum of neutron and proton densities and isovector is a
normalized difference. Here, we report on the experimental evidence for the
displacement of the isovector and isoscalar surfaces in nuclei, by $\sim$$0.9
\, \text{fm}$ from each other. We analyze data on quasielastic (QE) charge
exchange (p,n) reactions, concurrently with proton and neutron elastic
scattering data for the same target nuclei, following the concepts of the
isoscalar and isovector potentials combined into Lane optical potential. The
elastic data largely probe the geometry of the isoscalar potential and the
(p,n) data largely probe a relation between the geometries of the isovector and
isoscalar potentials. The targets include $^{48}$Ca, $^{90}$Zr, $^{120}$Sn and
$^{208}$Pb and projectile incident energy values span the range of
(10-50)$\,\text{MeV}$. In our fit to elastic and QE charge-exchange data, we
allow the values of isoscalar and isovector radii, diffusivities and overall
potential normalizations to float away from those in the popular Koning and
Delaroche parametrization. We find that the best-fit isovector radii are
consistently larger than isoscalar and the best-fit isovector surfaces are
steeper. Upon identifying the displacement of the potential surfaces with the
displacement of the surfaces for the densities in the Skyrme-Hartree-Fock
calculations, and by supplementing the results with those from analysing
excitation energies to isobaric analog states in the past, we arrive at the
slope and value of the symmetry energy at normal density of $70<L<101\,
\text{MeV}$ and $33.5<a_a^V<36.4\, \text{MeV}$, respectively.


title: Action2Activity: Recognizing Complex Activities from Sensor Data

abstract:
  As compared to simple actions, activities are much more complex, but
semantically consistent with a human's real life. Techniques for action
recognition from sensor generated data are mature. However, there has been
relatively little work on bridging the gap between actions and activities. To
this end, this paper presents a novel approach for complex activity recognition
comprising of two components. The first component is temporal pattern mining,
which provides a mid-level feature representation for activities, encodes
temporal relatedness among actions, and captures the intrinsic properties of
activities. The second component is adaptive Multi-Task Learning, which
captures relatedness among activities and selects discriminant features.
Extensive experiments on a real-world dataset demonstrate the effectiveness of
our work.


title: Geodetic Graphs Homeomorphic to a Given Geodetic Graph

abstract:
  This paper describes a new approach to the problem of generating the class of
all geodetic graphs homeomorphic to a given geodetic one. An algorithmic
procedure is elaborated to carry out a systematic finding of such a class of
graphs. As a result, the enumeration of the class of geodetic graphs
homeomorphic to certain Moore graphs has been performed.


title: Neural Machine Translation with Reconstruction

abstract:
  Although end-to-end Neural Machine Translation (NMT) has achieved remarkable
progress in the past two years, it suffers from a major drawback: translations
generated by NMT systems often lack of adequacy. It has been widely observed
that NMT tends to repeatedly translate some source words while mistakenly
ignoring other words. To alleviate this problem, we propose a novel
encoder-decoder-reconstructor framework for NMT. The reconstructor,
incorporated into the NMT model, manages to reconstruct the input source
sentence from the hidden layer of the output target sentence, to ensure that
the information in the source side is transformed to the target side as much as
possible. Experiments show that the proposed framework significantly improves
the adequacy of NMT output and achieves superior translation result over
state-of-the-art NMT and statistical MT systems.


title: Challenges of Feature Selection for Big Data Analytics

abstract:
  We are surrounded by huge amounts of large-scale high dimensional data. It is
desirable to reduce the dimensionality of data for many learning tasks due to
the curse of dimensionality. Feature selection has shown its effectiveness in
many applications by building simpler and more comprehensive model, improving
learning performance, and preparing clean, understandable data. Recently, some
unique characteristics of big data such as data velocity and data variety
present challenges to the feature selection problem. In this paper, we envision
these challenges of feature selection for big data analytics. In particular, we
first give a brief introduction about feature selection and then detail the
challenges of feature selection for structured, heterogeneous and streaming
data as well as its scalability and stability issues. At last, to facilitate
and promote the feature selection research, we present an open-source feature
selection repository (scikit-feature), which consists of most of current
popular feature selection algorithms.


title:
Approximate solutions of inverse problems for nonlinear space fractional
  diffusion equations with randomly perturbed data

abstract:
  This paper is concerned with backward problem for nonlinear space fractional
diffusion with additive noise on the right-hand side and the final value. To
regularize the instable solution, we develop some new regularized method for
solving the problem. In the case of constant coefficients, we use the
truncation methods. In the case of perturbed time dependent coefficients, we
apply a new quasi-reversibility method. We also show the convergence rate
between the regularized solution and the sought solution under some a priori
assumption on the sought solution.


title: Topological invariants for closed hypersurfaces

abstract:
  We consider closed and orientable immersed hypersurfaces of translational
manifolds. Given a vector field on such a hypersurface, we define a
perturbation of its Gauss map, which allows us to obtain topological invariants
for the immersion that depends on the geometry of the manifold and the ambient
space. We use these quantities to find obstructions to the existence of certain
codimension one foliations.


title:
Photoelectron angular distribution in two-pathway ionization of neon
  with femtosecond XUV pulses

abstract:
  We analyze the photoelectron angular distribution in two-pathway interference
between non\-resonant one-photon and resonant two-photon ionization of neon. We
consider a bichromatic femtosecond XUV pulse whose fundamental frequency is
tuned near the $2p^5 3s$ atomic states of neon. The time-dependent
Schr\"odinger equation is solved and the results are employed to compute the
angular distribution and the associated anisotropy parameters at the main
photoelectron line. We also employ a time-dependent perturbative approach,
which allows obtaining information on the process for a large range of pulse
parameters, including the steady-state case of continuous radiation, i.e., an
infinitely long pulse. The results from the two methods are in relatively good
agreement over the domain of applicability of perturbation theory.


title: Linear Sketching over $\mathbb F_2$

abstract:
  We initiate a systematic study of linear sketching over $\mathbb F_2$. For a
given Boolean function $f \colon \{0,1\}^n \to \{0,1\}$ a randomized $\mathbb
F_2$-sketch is a distribution $\mathcal M$ over $d \times n$ matrices with
elements over $\mathbb F_2$ such that $\mathcal Mx$ suffices for computing
$f(x)$ with high probability. We study a connection between $\mathbb
F_2$-sketching and a two-player one-way communication game for the
corresponding XOR-function. Our results show that this communication game
characterizes $\mathbb F_2$-sketching under the uniform distribution (up to
dependence on error). Implications of this result include: 1) a composition
theorem for $\mathbb F_2$-sketching complexity of a recursive majority
function, 2) a tight relationship between $\mathbb F_2$-sketching complexity
and Fourier sparsity, 3) lower bounds for a certain subclass of symmetric
functions. We also fully resolve a conjecture of Montanaro and Osborne
regarding one-way communication complexity of linear threshold functions by
designing an $\mathbb F_2$-sketch of optimal size.
  Furthermore, we show that (non-uniform) streaming algorithms that have to
process random updates over $\mathbb F_2$ can be constructed as $\mathbb
F_2$-sketches for the uniform distribution with only a minor loss. In contrast
with the previous work of Li, Nguyen and Woodruff (STOC'14) who show an
analogous result for linear sketches over integers in the adversarial setting
our result doesn't require the stream length to be triply exponential in $n$
and holds for streams of length $\tilde O(n)$ constructed through uniformly
random updates. Finally, we state a conjecture that asks whether optimal
one-way communication protocols for XOR-functions can be constructed as
$\mathbb F_2$-sketches with only a small loss.


title:
Inductive decision based Real Time Occupancy detector in University
  Buildings

abstract:
  The ability to estimate College Campus Occupancy for Classrooms and Labs in
real time has become one of the major concerns for various Academicians,
authorities and administrators,where still a manual attendance marking system
is being followed. Using a low budget multiple sensor setup installed in a
college auditorium, the goal is to build a real-time occupancy detector. This
paper presents an Inductive real time Decision tree based classifier using
multiple sensor dataset to detect occupancy. Using simple feature based
thresholds, Reverberation time which comes out to be a novel as well as most
distinguishing feature sampled at various frequencies over a given time
interval was used to detect the occupancy with an accuracy of %.Addition of
various other sensor data, decreased the accuracy of classification results.
The detector setup can be used in various college buildings to provide real
time centralised occupancy status thus automating the manual attendance system
being used.


title:
A Fast Iterative Method for Chandrasekhar's H-functions for General Laws
  of Scattering

abstract:
  This work shows that notable acceleration of the speed of calculating
Chandrasekhar's H-functions for general laws of scattering with an iterative
method can be realized by supplying a starting pproximation produced by the
following procedure: (i) in the cases of azimuth-angle independent Fourier
components, values of the isotropic scattering H-function given by an accurate
yet simple-to-apply formula, in particular, the one by Kawabata and Limaye
(Astrophys. and Space Sci. Vol. 332, 365-371, 2011 DOI
10.1007/s10509-010-0512-x; see also Astrophys. and Space Sci. Vol. 348, 601,
2013 DOI 10.1007/1009-013-1589-9, for erratum), and (ii) for azimuth-angle
dependent Fourier components, an already obtained solution of the next lower
order term. The paper has been published in Astrophys. and Space Sci. Vol. 358,
32-38 (2015) DOI 10.1007/s10509-015-2434-0, and the final publication is
available at link.springer.com.


title:
Classification of entire solutions of $(-\Delta)^N u + u^{-(4N-1)}= 0$
  with exact linear growth at infinity in $\mathbf R^{2N-1}$

abstract:
  In this paper, we study global positive $C^{2N}$-solutions of the
geometrically interesting equation $(-\Delta)^N u + u^{-(4N-1)}= 0$ in $\mathbf
R^{2N-1}$. We prove that any $C^{2N}$-solution $u$ of the equation having
linear growth at infinity must satisfy the integral equation \[ u(x) = c_0
\int_{\mathbf R^{2N-1}} {|x - y|{u^{-(4N-1)}}(y)dy} \] for some positive
constant $c_0$ and hence takes the following form \[ u(x) = (1+|x|^2)^{1/2} \]
in $\mathbf R^{2N-1}$ up to dilations and translations. We also provide several
non-existence results for positive $C^{2N}$-solutions of $(-\Delta)^N u =
u^{-(4N-1)}$ in $\mathbf R^{2N-1}$.


title: The classification of some generalised Bunce-Deddens algebras

abstract:
  We use $K$-theory to prove an isomorphism theorem for a large class of
generalised Bunce-Deddens algebras constructed by Kribs and Solel from a
directed graph $E$ and a sequence $\omega$ of positive integers. In particular,
we compute the torsion-free component of the $K_0$-group for a class of
generalised Bunce-Deddens algebras to show that supernatural numbers are a
complete invariant for this class.


title:
AC-BLSTM: Asymmetric Convolutional Bidirectional LSTM Networks for Text
  Classification

abstract:
  Recently deeplearning models have been shown to be capable of making
remarkable performance in sentences and documents classification tasks. In this
work, we propose a novel framework called AC-BLSTM for modeling sentences and
documents, which combines the asymmetric convolution neural network (ACNN) with
the Bidirectional Long Short-Term Memory network (BLSTM). Experiment results
demonstrate that our model achieves state-of-the-art results on five tasks,
including sentiment analysis, question type classification, and subjectivity
classification. In order to further improve the performance of AC-BLSTM, we
propose a semi-supervised learning framework called G-AC-BLSTM for text
classification by combining the generative model with AC-BLSTM.


title: Testing averaged cosmology with type Ia supernovae and BAO data

abstract:
  An important problem in precision cosmology is the determination of the
effects of averaging and backreaction on observational predictions,
particularly in view of the wealth of new observational data and improved
statistical techniques. In this paper, we discuss the observational viability
of a class of averaged cosmologies which consist of a simple parametrized
phenomenological two-scale backreaction model with decoupled spatial curvature
parameters. We perform a Bayesian model selection analysis and find that this
class of averaged phenomenological cosmological models is favored with respect
to the standard $\Lambda$CDM cosmological scenario when a joint analysis of
current SNe Ia and BAO data is performed. In particular, the analysis provides
observational evidence for non-trivial spatial curvature.


title:
An Information-Theoretic Framework for Fast and Robust Unsupervised
  Learning via Neural Population Infomax

abstract:
  A framework is presented for unsupervised learning of representations based
on infomax principle for large-scale neural populations. We use an asymptotic
approximation to the Shannon's mutual information for a large neural population
to demonstrate that a good initial approximation to the global
information-theoretic optimum can be obtained by a hierarchical infomax method.
Starting from the initial solution, an efficient algorithm based on gradient
descent of the final objective function is proposed to learn representations
from the input datasets, and the method works for complete, overcomplete, and
undercomplete bases. As confirmed by numerical experiments, our method is
robust and highly efficient for extracting salient features from input
datasets. Compared with the main existing methods, our algorithm has a distinct
advantage in both the training speed and the robustness of unsupervised
representation learning. Furthermore, the proposed method is easily extended to
the supervised or unsupervised model for training deep structure networks.

categories: cs.LG cs.AI cs.IT math.IT q-bio.NC stat.ML


title:
Sum-networks from incidence structures: construction and capacity
  analysis

abstract:
  A sum-network is an instance of a network coding problem over a directed
acyclic network in which each terminal node wants to compute the sum over a
finite field of the information observed at all the source nodes. Many
characteristics of the well-studied multiple unicast network communication
problem also hold for sum-networks due to a known reduction between instances
of these two problems. In this work, we describe an algorithm to construct
families of sum-network instances using incidence structures. The computation
capacity of several of these sum-network families is characterized. We
demonstrate that unlike the multiple unicast problem, the computation capacity
of sum-networks depends on the characteristic of the finite field over which
the sum is computed. This dependence is very strong; we show examples of
sum-networks that have a rate-1 solution over one characteristic but a rate
close to zero over a different characteristic. Additionally, a sum-network can
have an arbitrary different number of computation capacities for different
alphabets. This is contrast to the multiple unicast problem where it is known
that the capacity is independent of the network coding alphabet.


title: Boundary Terms and Three-Point Functions: An AdS/CFT Puzzle Resolved

abstract:
  ${\cal N} = 8$ superconformal field theories, such as the ABJM theory at
Chern-Simons level $k=1$ or $2$, contain 35 scalar operators ${\cal O}_{IJ}$
with $\Delta=1$ in the ${\bf 35}_v$ representation of SO(8). The 3-point
correlation function of these operators is non-vanishing, and indeed can be
calculated non-perturbatively in the field theory. But its AdS$_4$ gravity
dual, obtained from gauged ${\cal N}=8$ supergravity, has no cubic $A^3$
couplings in its Lagrangian, where $A^{IJ}$ is the bulk dual of ${\cal
O}_{IJ}$. So conventional Witten diagrams cannot furnish the field theory
result. We show that the extension of bulk supersymmetry to the AdS$_4$
boundary requires the introduction of a finite $A^3$ counterterm that does
provide a perfect match to the 3-point correlator. Boundary supersymmetry also
requires infinite counterterms which agree with the method of holographic
renormalization. The generating functional of correlation functions of the
$\Delta=1$ operators is the Legendre transform of the on-shell action, and the
supersymmetry properties of this functional play a significant role in our
treatment.


title:
Inverting OII 83.4 nm Dayglow Profiles Using Markov Chain Radiative
  Transfer

abstract:
  Emission profiles of the resonantly scattered OII~83.4~nm triplet can in
principle be used to estimate \(\mathrm{O}^+\) density profiles in the F2
region of the ionosphere. Given the emission source profile, solution of this
inverse problem is possible, but requires significant computation. The
traditional Feautrier solution to the radiative transfer problem requires many
iterations to converge, making it time-consuming to compute. A Markov chain
approach to the problem produces similar results by directly constructing a
matrix that maps the source emission rate to an effective emission rate which
includes scattering to all orders. The Markov chain approach presented here
yields faster results and therefore can be used to perform the \(\mathrm{O}^+\)
density retrieval with higher resolution than would otherwise be possible.


title:
OSMnx: New Methods for Acquiring, Constructing, Analyzing, and
  Visualizing Complex Street Networks

abstract:
  Urban scholars have studied street networks in various ways, but there are
data availability and consistency limitations to the current urban
planning/street network analysis literature. To address these challenges, this
article presents OSMnx, a new tool to make the collection of data and creation
and analysis of street networks simple, consistent, automatable and sound from
the perspectives of graph theory, transportation, and urban design. OSMnx
contributes five significant capabilities for researchers and practitioners:
first, the automated downloading of political boundaries and building
footprints; second, the tailored and automated downloading and constructing of
street network data from OpenStreetMap; third, the algorithmic correction of
network topology; fourth, the ability to save street networks to disk as
shapefiles, GraphML, or SVG files; and fifth, the ability to analyze street
networks, including calculating routes, projecting and visualizing networks,
and calculating metric and topological measures. These measures include those
common in urban design and transportation studies, as well as advanced measures
of the structure and topology of the network. Finally, this article presents a
simple case study using OSMnx to construct and analyze street networks in
Portland, Oregon.


title: Joint Multimodal Learning with Deep Generative Models

abstract:
  We investigate deep generative models that can exchange multiple modalities
bi-directionally, e.g., generating images from corresponding texts and vice
versa. Recently, some studies handle multiple modalities on deep generative
models, such as variational autoencoders (VAEs). However, these models
typically assume that modalities are forced to have a conditioned relation,
i.e., we can only generate modalities in one direction. To achieve our
objective, we should extract a joint representation that captures high-level
concepts among all modalities and through which we can exchange them
bi-directionally. As described herein, we propose a joint multimodal
variational autoencoder (JMVAE), in which all modalities are independently
conditioned on joint representation. In other words, it models a joint
distribution of modalities. Furthermore, to be able to generate missing
modalities from the remaining modalities properly, we develop an additional
method, JMVAE-kl, that is trained by reducing the divergence between JMVAE's
encoder and prepared networks of respective modalities. Our experiments show
that our proposed method can obtain appropriate joint representation from
multiple modalities and that it can generate and reconstruct them more properly
than conventional VAEs. We further demonstrate that JMVAE can generate multiple
modalities bi-directionally.


title:
Semiclassical asymptotics of $\operatorname{GL}_N(\mathbb{C})$ tensor
  products and quantum random matrices

abstract:
  The Littlewood--Richardson process is a discrete random point process arising
from the isotypic decomposition of tensor products of irreducible
representations of $\operatorname{GL}_N(\mathbb{C})$. Biane--Perelomov--Popov
matrices are quantum random matrices obtained as the geometric quantization of
random Hermitian matrices with deterministic eigenvalues and uniformly random
eigenvectors. As first observed by Biane, correlation functions of certain
global observables of the LR process coincide with correlation functions of
linear statistics of sums of classically independent BPP matrices, thereby
enabling a random matrix approach to the statistical study of
$\operatorname{GL}_N(\mathbb{C})$ tensor products. In this paper, we prove an
optimal result: classically independent BPP matrices become freely independent
in any semiclassical/large-dimension limit. This proves and generalizes a
conjecture of Bufetov and Gorin, and leads to a Law of Large Numbers for the
BPP observables of the LR process which holds in any and all semiclassical
scalings.


title:
${\cal N}=2$ heterotic string compactifications on orbifolds of
  $K3\times T^2$

abstract:
  We study ${\cal N}=2$ compactifications of $E_8\times E_8$ heterotic string
theory on orbifolds of $K3 \times T^2$ by $g'$ which acts as an $\mathbb{Z}_N$
automorphism of $K3$ together with a$1/N$ shift on a circle of $T^2$. The
orbifold action $g'$ corresponds to the $26$ conjugacy classes of the Mathieu
group $M_{24}$. We show that for the standard embedding the new supersymmetric
index for these compactifications can always be decomposed into the elliptic
genus of $K3$ twisted by $g'$. The difference in one-loop corrections to the
gauge couplings are captured by automorphic forms obtained by the theta lifts
of the elliptic genus of $K3$ twisted by $g'$. We work out in detail the case
for which $g'$ belongs to the equivalence class $2B$. We then investigate all
the non-standard embeddings for$K3$ realized as a $T^4/\mathbb{Z}_\nu$ orbifold
with $\nu = 2, 4$ and $g'$ the $2A$ involution. We show that for non-standard
embeddings the new supersymmetric index as well as the difference in one-loop
corrections to the gauge couplings are completely characterized by the
instanton numbers of the embeddings together with the difference in number of
hypermultiplets and vector multiplets in the spectrum.


title: Synchronization dynamics in a designed open system

abstract:
  We theoretically propose a unifying expression for synchronization dynamics
between two-level constituents. Although synchronization phenomena require some
substantial mediators, the distinct repercussions of their propagation delays
remain obscure, especially in open systems. Our scheme directly incorporates
the details of the constituents and mediators in an arbitrary environment. As
one example, we demonstrate the synchronization dynamics of optical emitters on
a dielectric microsphere. We reveal that the whispering gallery modes (WGMs)
bridge the well-separated emitters and accelerate the synchronized
fluorescence, known as superfluorescence. The emitters are found to overcome
the significant and nonuniform retardation, and to build up their pronounced
coherence by the WGMs, striking a balance between the roles of resonator and
intermediary. Our work directly illustrates the dynamical aspects of many-body
synchronizations and contributes to the exploration of research paradigms that
consider designed open systems.


title:
Design of a wavelength-tunable optical tweezer using a graded-index
  multimode optical fiber

abstract:
  A wavelength-tunable Optical Fiber Tweezer (OFT) based on a Graded Index
Multimode Fiber (GIMF) with a flat endface is proposed. It is shown that the
design can support a trapping position which is far from the tip of the GIMF
compared with other common optical tweezing methods, hence reducing the
possibility of a contact between the trapped particle and the fiber tip.
Moreover, because of the wavelength dependence of the GIMF design parameters
such the Numerical Aperture (NA), the trapping position can become
wavelength-dependent. Therefore, the trapping position can be tuned over a long
range using a common wave-length tunable laser. The proposed OFT differs from
previous fiber-based demonstrations by using a flat-endface fiber making the
fabrication and experiment quite easier than previously proposed
tapered-endface OFTs.


title:
Asymptotic boundary behavior of the Bergman curvatures of a pseudoconvex
  domain

abstract:
  We present a method of obtaining a lower bound estimate of the curvatures of
the Bergman metric without using the regularity of the kernel function on the
boundary. As an application, we prove the existence of an uniform lower bound
of the bisectional curvatures of the Bergman metric of a smooth bounded
pseudoconvex domain near the boundary with constant Levi rank.


title:
Unique catalytic decomposition and reduction of hydrogen peroxide and
  organic peroxides on magnesia (001) promoted by oxide-metal hybrid
  nanostructure

abstract:
  The detection, removal and reduction of hydrogen peroxide is of significant
importance for its increasing application in the areas of environment, food,
electrochemistry and clinical laboratory. Herein the dissociative adsorption
behavior of hydrogen peroxide on ultrathin magnesia (001) films deposited on
transition metal is uncovered for the first time by employing periodic
density-functional theory calculations with van der Waals corrections. The
hydrogen peroxide is dissociated smoothly and reduced to surface hydroxyls on
MgO(001)/TM, and the dissociative adsorption energies of all the considered
fragmentation configurations are substantially negative, demonstrating
dissociation and reduction of hydrogen peroxide on MgO(001)/TM is
thermodynamically favorable. The dissociative adsorption energy decreases
monotonously with increasing film thickness, demonstrating the lower reactivity
of thick oxide films. Moreover, we examined the suitability of several
transition metal slabs (molybdenum, silver, vanadium, tungsten and gold)
combined with magnesia for splitting hydrogen peroxide. The dissociative
adsorption energies enhance when the lattice constants of substrate slabs
increase, indicating the chemisorption strength can be tuned by category of
metal slabs as well as thickness of oxide film. The mechanism of reactivity
enhancement for energetically and dynamically favorable decomposition of
hydrogen peroxide on supported magnesia is elucidated by characterizing the
geometric structures and electronic properties. The fragmentation and reduction
of diethyl peroxide and peroxyacetone are also studied to reveal the catalytic
activity of ultrathin magnesia toward splitting organic peroxides. The results
are wished to provide useful clue for detecting and reducing hydrogen peroxide
and organic peroxides by employing oxide-metal hybrid nanostructure.


title:
An Extension of Chubanov's Polynomial-Time Linear Programming Algorithm
  to Second-Order Cone Programming

abstract:
  Recently, Chubanov proposed an interesting new polynomial-time algorithm for
linear program. In this paper, we extend his algorithm to second-order cone
programming.


title:
Dark energy equation of state parameter and its variation at low
  redshifts

abstract:
  In this paper, we constrain dark energy models using a compendium of
observations at low redshifts. We consider the dark energy as a barotropic
fluid, with the equation of state a constant as well the case where dark energy
equation of state is a function of time. The observations considered here are
Supernova Type Ia data, Baryonic Acoustic Oscillation data and Hubble parameter
measurements. We compare constraints obtained from these data and also do a
combined analysis. The combined observational constraints put strong limits on
variation of dark energy energy density with redshift. For varying dark energy
models, the range of parameters preferred by the supernova type Ia data is in
tension with the other low redshift distance measurements.


title:
Optimal rates for the regularized learning algorithms under general
  source condition

abstract:
  We consider the learning algorithms under general source condition with the
polynomial decay of the eigenvalues of the integral operator in vector-valued
function setting. We discuss the upper convergence rates of Tikhonov
regularizer under general source condition corresponding to increasing monotone
index function. The convergence issues are studied for general regularization
schemes by using the concept of operator monotone index functions in minimax
setting. Further we also address the minimum possible error for any learning
algorithm.


title: On $(1,2)$-step competition graphs of bipartite tournaments

abstract:
  In this paper, we study $(1,2)$-step competition graphs of bipartite
tournaments. A bipartite tournament means an orientation of a complete
bipartite graph. We show that the $(1,2)$-step competition graph of a bipartite
tournament has at most one non-trivial component or consists of exactly two
complete components of size at least three and, especially in the former, the
diameter of the nontrivial component is at most three if it exists. Based on
this result, we show that, among the connected non-complete graphs which are
triangle-free or the cycles of which are edge-disjoint, $K_{1,4}$ is the only
graph that can be represented as the $(1,2)$-step competition graph of a
bipartite tournament. We also completely characterize a complete graph and the
disjoint union of two complete graphs, respectively, which can be represented
as the $(1,2)$-step competition graph of a bipartite tournament. Finally we
present the maximum number of edges and the minimum number of edges which the
$(1,2)$-step competition graph of a bipartite tournament might have.


title:
Scalar curvature rigidity and Ricci Deturck flow on perturbations of
  Euclidean Space

abstract:
  We prove a rigidity result for non-negative scalar curvature perturbations of
the Euclidean metric on $\mathbb{R^n}$ , which may be regarded as a weak
version of the rigidity statement of the positive mass theorem. We prove our
result by analyzing long time solutions of Ricci DeTurck flow. As a byproduct
in doing so, we extend known $L^p$ bounds and decay rates for Ricci DeTurck
flow and prove regularity of the flow at the initial data.


title: Derived categories of graded gentle one-cycle algebras

abstract:
  Let $A$ be a graded algebra. It is shown that the derived category of dg
modules over $A$ (viewed as a dg algebra with trivial differential) is a
triangulated hull of a certain orbit category of the derived category of graded
$A$-modules. This is applied to study derived categories of graded gentle
one-cycle algebras.


title: On Edge Dimension of a Graph

abstract:
  Given a connected graph $G(V, E)$, the edge dimension, denoted
$\mathrm{edim}(G)$, is the least size of a set $S \subseteq V$ that
distinguishes every pair of edges of $G$, in the sense that the edges have
pairwise distinct tuples of distances to the vertices of $S$. The notation was
introduced by Kelenc, Tratnik, and Yero, and in their paper, they asked several
questions about properties of $\mathrm{edim}$. In this article we answer two of
these questions: we classify the graphs for which $\mathrm{edim}(G) = n-1$ and
show that $\frac{\mathrm{edim}(G)}{\dim(G)}$ isn't bounded from above (here
$\dim(G)$ is the standard metric dimension of $G$). We also compute
$\mathrm{edim}(G\Box P_m)$ and $\mathrm{edim}(G + K_1)$.


title: Some refinements of Hermite-Hadamard inequality and an open problem

abstract:
  We presented here a refinement of Hermite-Hadamard inequality as a linear
combination of its end-points. The problem of best possible constants is
closely connected with well known Simpson's rule in numerical integration. It
is solved here for a wide class of convex functions, but not in general. Some
supplementary results are also given.


title:
Scale-invariant perturbations from NEC violation: A new variant of
  Galilean Genesis

abstract:
  We propose a novel branch of the Galilean Genesis scenario as an alternative
to inflation, in which the universe starts expanding from Minkowski in the
asymptotic past with a gross violation of the null energy condition (NEC). This
variant, described by several functions and parameters within the Horndeski
scalar-tensor theory, shares the same background dynamics with the existing
Genesis models, but the nature of primordial quantum fluctuations is quite
distinct. In some cases, tensor perturbations grow on superhorizon scales. The
tensor power spectrum can be red, blue, or scale invariant, depending on the
model, while scalar perturbations are nearly scale invariant. This is in sharp
contrast to typical NEC-violating cosmologies, in which a blue tensor tilt is
generated. Though the primordial tensor and scalar spectra are both nearly
scale invariant as in the inflationary scenario, the consistency relation in
our variant of Galilean Genesis is non-standard.


title:
Privacy Preserving PageRank Algorithm By Using Secure Multi-Party
  Computation

abstract:
  In this work, we study the problem of privacy preserving computation on
PageRank algorithm. The idea is to enforce the secure multi party computation
of the algorithm iteratively using homomorphic encryption based on Paillier
scheme. In the proposed PageRank computation, a user encrypt its own graph data
using asymmetric encryption method, sends the data set into different parties
in a privacy-preserving manner. Each party computes its own encrypted entity,
but learns nothing about the data at other parties.


title:
Spreading in space-time periodic media governed by a monostable equation
  with free boundaries, Part 2: Spreading speed

abstract:
  This is Part 2 of our work aimed at classifying the long-time behavior of the
solution to a free boundary problem with monostable reaction term in space-time
periodic media. In Part 1 (see \cite{ddl}) we have established a theory on the
existence and uniqueness of solutions to this free boundary problem with
continuous initial functions, as well as a spreading-vanishing dichotomy. We
are now able to develop the methods of Weinberger \cite{w1, w2} and others
\cite{fyz,lyz,lz1,lz2,lui} to prove the existence of asymptotic spreading speed
when spreading happens, without knowing a priori the existence of the
corresponding semi-wave solutions of the free boundary problem. This is a
completely different approach from earlier works on the free boundary model,
where the spreading speed is determined by firstly showing the existence of a
corresponding semi-wave. Such a semi-wave appears difficult to obtain by the
earlier approaches in the case of space-time periodic media considered in our
work here.


title:
Spreading in space-time periodic media governed by a monostable equation
  with free boundaries, Part 1: Continuous initial functions

abstract:
  We aim to classify the long-time behavior of the solution to a free boundary
problem with monostable reaction term in space-time periodic media. Such a
model may be used to describe the spreading of a new or invasive species, with
the free boundary representing the expanding front. In time-periodic and space
homogeneous environment, as well as in space-periodic and time autonomous
environment, such a problem has been studied recently in \cite{dgp, dl}. In
both cases, a spreading-vanishing dichotomy has been established, and when
spreading happens, the asymptotic spreading speed is proved to exist by making
use of the corresponding semi-wave solutions. The approaches in \cite{dgp, dl}
seem difficult to apply to the current situation where the environment is
periodic in both space and time. Here we take a different approach, based on
the methods developed by Weinberger \cite{w1, w2} and others
\cite{fyz,lyz,lz1,lz2,lui}, which yield the existence of the spreading speed
without using traveling wave solutions.
  In Part 1 of this work, we establish the existence and uniqueness of
classical solutions for the free boundary problem with continuous initial data,
extending the existing theory which was established only for $C^2$ initial
data. This will enable us to develop Weinberger's method in Part 2 to determine
the spreading speed without knowing a priori the existence of the corresponding
semi-wave solutions. In Part 1 here, we also establish a spreading-vanishing
dichotomy.


title: Dust and Gas environment of the young embedded cluster IRAS 18511+0146

abstract:
  IRAS 18511+0146 is a young embedded (proto)cluster located at 3.5 kpc
surrounding what appears to be an intermediate mass protostar. In this paper,
we investigate the nature of cluster members (two of which are believed to be
the most massive and luminous) using imaging and spectroscopy in the near and
mid-infrared. The brightest point-like object associated with IRAS 18511+0146
is referred to as S7 in the present work (designated UGPS J185337.88+015030.5
in the UKIRT Galactic Plane survey). Seven of the nine objects show rising
spectral energy distributions (SED) in the near-infrared, with four objects
showing Br-gamma emission. Three members: S7, S10 (also UGPS
J185338.37+015015.3) and S11 (also UGPS J185338.72+015013.5) are bright in
mid-infrared with diffuse emission being detected in the vicinity of S11 in PAH
bands. Silicate absorption is detected towards these three objects, with an
absorption maximum between 9.6 and 9.7 um, large optical depths (1.8-3.2), and
profile widths of 1.6-2.1 um. The silicate profiles of S7 and S10 are similar,
in contrast to S11 (which has the largest width and optical depth). The cold
dust emission investigated using Herschel HiGal peaks at S7, with temperature
at 26 K and column density N(H2) ~ 7 x 10^(22) cm^(-2). The bolometric
luminosity of IRAS 18511 region is L ~ 1.8 x 10^4 L_sun. S7 is the main
contributor to the bolometric luminosity, with L (S7) > 10^4 L_sun. S7 is a
high mass protostellar object with ionised stellar winds, evident from the
correlation between radio and bolometric luminosity as well as the asymmetric
Br-gamma profile. The differences in silicate profiles of S7 and S11 could be
due to different radiation environment as we believe the former to be more
massive and in an earlier phase than the latter.


title: Me, Myself and My Killfie: Characterizing and Preventing Selfie Deaths

abstract:
  Over the past couple of years, clicking and posting selfies has become a
popular trend. However, since March 2014, 127 people have died and many have
been injured while trying to click a selfie. Researchers have studied selfies
for understanding the psychology of the authors, and understanding its effect
on social media platforms. In this work, we perform a comprehensive analysis of
the selfie-related casualties and infer various reasons behind these deaths. We
use inferences from incidents and from our understanding of the features, we
create a system to make people more aware of the dangerous situations in which
these selfies are taken. We use a combination of text-based, image-based and
location-based features to classify a particular selfie as dangerous or not.
Our method ran on 3,155 annotated selfies collected on Twitter gave 73%
accuracy. Individually the image-based features were the most informative for
the prediction task. The combination of image-based and location-based features
resulted in the best accuracy. We have made our code and dataset available at
http://labs.precog.iiitd.edu.in/killfie.


title:
Category specificity of N170 response recovery speeds for faces and
  Chinese characters

abstract:
  Neural selectivity of N170 responses is an important phenomenon in perceptual
processing; however, the recovery times of neural selective responses remain
unclear. In the present study, we used an adaptation paradigm to test the
recovery speeds of N170 responses to faces and Chinese characters. The results
showed that recovery of N170 responses elicited by faces occurred between 1400
and 1800 ms after stimuli onset, whereas recovery of N170 responses elicited by
Chinese characters occurred between 600 and 800 ms after stimuli onset. These
results demonstrate category-specific recovery speeds of N170 responses
involved in the processing of faces and Chinese characters.


title: The Compton-Schwarzschild relations in higher dimensions

abstract:
  In three spatial dimensions, the Compton wavelength $(R_C \propto M^{-1}$)
and Schwarzschild radius $(R_S \propto M$) are dual under the transformation $M
\rightarrow M_{P}^2/M$, where $M_{P}$ is the Planck mass. This suggests that
there is a fundamental link -- termed the Black Hole Uncertainty Principle or
Compton-Schwarzschild correspondence -- between elementary particles in the $M
< M_{P}$ regime and black holes in the $M > M_{P}$ regime. In the presence of
$n$ extra dimensions, compactified on some scale $R_E$, one expects $R_S
\propto M^{1/(1+n)}$ for $R < R_E$, which breaks this duality. However, it may
be restored in some circumstances because the effective Compton wavelength
depends on the form of the $(3+n)$-dimensional wavefunction. If this is
spherically symmetric, then one still has $R_C \propto M^{-1}$, as in the
$3$-dimensional case. The effective Planck length is then increased and the
Planck mass reduced, allowing the possibility of TeV quantum gravity and black
hole production at the LHC. However, if the wave function is pancaked in the
extra dimensions and maximally asymmetric, then $R_C \propto M^{-1/(1+n)}$, so
that the duality between $R_C$ and $R_S$ is preserved. In this case, the
effective Planck length is reduced but the Planck mass is unchanged, so TeV
quantum gravity is precluded and black holes cannot be generated in collider
experiments. Nevertheless, the extra dimensions could still have consequences
for the detectability of black hole evaporations and the enhancement of
pair-production at accelerators on scales below $R_E$. Though
phenomenologically general for higher-dimensional theories, our results are
shown to be consistent with string theory via the minimum positional
uncertainty derived from $D$-particle scattering amplitudes.


title: A jet-driven dynamo (JEDD) from jets-inflated bubbles in cooling flows

abstract:
  I suggest that the main process that amplifies magnetic fields in cooling
flows in clusters and group of galaxies is a jet-driven dynamo (JEDD). The main
processes that are behind the JEDD is the turbulence that is formed by the many
vortices formed in the inflation processes of bubbles, and the large scale
shear formed by the propagating jet. It is sufficient that a strong turbulence
exits in the vicinity of the jets and bubbles, just where the shear is large.
The typical amplification time of magnetic fields by the JEDD near the jets and
bubbles is approximately hundred million years. The amplification time in the
entire cooling flow region is somewhat longer. The vortices that create the
turbulence are those that also transfer energy from the jets to the
intra-cluster medium, by mixing shocked jet gas with the intra-cluster medium
gas, and by exciting sound waves. The JEDD model adds magnetic fields to the
cyclical behavior of energy and mass in the jet-feedback mechanism (JFM) in
cooling flows.


title:
On the numerical range of square matrices with coefficients in a degree
  2 Galois field extension

abstract:
  Let $L$ be a degree $2$ Galois extension of the field $K$ and $M$ an $n\times
n$ matrix with coefficients in $L$. Let $\langle \ ,\ \rangle : L^n\times
L^n\to L$ be the sesquilinear form associated to the involution $L\to L$ fixing
$K$. We use $\langle \ ,\ \rangle$ to define the numerical range $\mathrm{Num}
(M)$ of $M$ (a subset of $L$), extending the classical case $K=\mathbb {R}$,
$L=\mathbb {C}$ and the case of a finite field introduced by Coons, Jenkins,
Knowles, Luke and Rault. There are big differences with respect to both cases
for number fields and for all fields in which the image of the norm map $L\to
K$ is not closed by addition, e.g., $c\in L$ may be an eigenvalue of $M$, but
$c\notin \mathrm{Num} (M)$. We compute $\mathrm{Num} (M)$ in some case, mostly
with $n=2$.


title:
The Electronic States of a Double Carbon Vacancy Defect in Pyrene: A
  Model Study for Graphene

abstract:
  The electronic states occurring in a double vacancy defect for graphene
nanoribbons have been calculated in detail based on a pyrene model. Extended ab
initio calculations using the MR configuration interaction (MRCI) method have
been performed to describe in a balanced way the manifold of electronic states
derived from the dangling bonds created by initial removal of two neighboring
carbon atoms from the graphene network. In total, this study took into account
the characterization of 16 electronic states (eight singlets and eight
triplets) considering unrelaxed and relaxed defect structures. The ground state
was found to be of 1Ag character with around 50% closed shell character. The
geometry optimization process leads to the formation of two five-membered rings
in a pentagon octagon pentagon structure. The closed shell character increases
thereby to ~70%, the analysis of unpaired density shows only small
contributions confirming the chemical stability of that entity. For the
unrelaxed structure the first five excited states (3B3g, 3B2u, 3B1u, 3Au and
1Au) are separated from the ground state by less than 2.5 eV. For comparison,
unrestricted density functional theory (DFT) calculations using several types
of functionals have been performed within different symmetry subspaces defined
by the open shell orbitals. Comparison with the MRCI results gave good
agreement in terms of finding the 1Ag state as ground state and in assigning
the lowest excited states. Linear interpolation curves between the unrelaxed
and relaxed defect structures also showed good agreement between the two
classes of methods opening up the possibilities of using extended nanoflakes
for multistate investigations at DFT level.


title: Algebraic Multigrid Methods

abstract:
  This paper is to give an overview of AMG methods for solving large scale
systems of equations such as those from the discretization of partial
differential equations. AMG is often understood as the acronym of "Algebraic
Multi-Grid", but it can also be understood as "Abstract Muti-Grid". Indeed, as
it demonstrates in this paper, how and why an algebraic multigrid method can be
better understood in a more abstract level. In the literature, there are a
variety of different algebraic multigrid methods that have been developed from
different perspectives. In this paper, we try to develop a unified framework
and theory that can be used to derive and analyze different algebraic multigrid
methods in a coherent manner. Given a smoother $R$ for a matrix $A$, such as
Gauss-Seidel or Jacobi, we prove that the optimal coarse space of dimension
$n_c$ is the span of the eigen-vectors corresponding to the first $n_c$
eigenvalues of $\bar RA$ (with $\bar R=R+R^T-R^TAR$). We also prove that this
optimal coarse space can be obtained by a constrained trace-minimization
problem for a matrix associated with $\bar RA$ and demonstrate that coarse
spaces of most of existing AMG methods can be viewed some approximate solution
of this trace-minimization problem. Furthermore, we provide a general approach
to the construction of a quasi-optimal coarse space and we prove that under
appropriate assumptions the resulting two-level AMG method for the underlying
linear system converges uniformly with respect to the size of the problem, the
coefficient variation, and the anisotropy. Our theory applies to most existing
multigrid methods, including the standard geometric multigrid method, the
classic AMG, energy-minimization AMG, unsmoothed and smoothed aggregation AMG,
and spectral AMGe.


title:
Finite dimensional global attractor of the Cahn-Hilliard-Navier-Stokes
  system with dynamic boundary conditions

abstract:
  In this paper, we mainly consider the long-time behavior of solutions for the
Cahn-Hilliard-Navier-Stokes system with dynamic boundary conditions and two
polynomial growth nonlinearities of arbitrary order. We prove the existence of
a finite dimensional global attractor for the Cahn-Hilliard-Navier-Stokes
system with dynamic boundary conditions by using the $\ell$-trajectories
method.


title: Decision Tree Classification with Differential Privacy: A Survey

abstract:
  Data mining information about people is becoming increasingly important in
the data-driven society of the 21st century. Unfortunately, sometimes there are
real-world considerations that conflict with the goals of data mining;
sometimes the privacy of the people being data mined needs to be considered.
This necessitates that the output of data mining algorithms be modified to
preserve privacy while simultaneously not ruining the predictive power of the
outputted model. Differential privacy is a strong, enforceable definition of
privacy that can be used in data mining algorithms, guaranteeing that nothing
will be learned about the people in the data that could not already be
discovered without their participation. In this survey, we focus on one
particular data mining algorithm -- decision trees -- and how differential
privacy interacts with each of the components that constitute decision tree
algorithms. We analyze both greedy and random decision trees, and the conflicts
that arise when trying to balance privacy requirements with the accuracy of the
model.


title:
Higher order representation stability and ordered configuration spaces
  of manifolds

abstract:
  Using the language of twisted skew-commutative algebras, we define
\emph{secondary representation stability}, a stability pattern in the {\it
unstable} homology of spaces that are representation stable in the sense of
Church, Ellenberg, and Farb. We show that the rational homology of
configuration spaces of ordered points in noncompact manifolds satisfies
secondary representation stability. While representation stability for the
homology of configuration spaces involves stabilizing by introducing a point
``near infinity,'' secondary representation stability involves stabilizing by
introducing a pair of orbiting points -- an operation that relates homology
groups in different homological degrees. This result can be thought of as a
representation-theoretic analogue of \emph{secondary homological stability} in
the sense of Galatius, Kupers, and Randal-Williams. In the course of the proof
we establish some additional results: we give a new characterization of the
homology of the complex of injective words, and we give a new proof of integral
representation stability for configuration spaces of noncompact manifolds,
extending previous results to nonorientable manifolds.


title:
$p$-adic multiple zeta values and $p$-adic pro-unipotent harmonic
  actions : summary of parts I and II

abstract:
  This is a review on the two first parts of our work on $p$-adic multiple zeta
values at $N$-th roots of unity ($p$MZV$\mu_{N}$'s), the $p$-adic periods of
the crystalline pro-unipotent fundamental groupoid of $\mathbb{P}^{1} -
\{0,\mu_{N},\infty\}$ (where $N$ and $p$ are coprime). We restrict for
simplicity the review to the case of $N=1$, i.e. the case of $p$-adic multiple
zeta values ($p$MZV's). The main tools are new objects which we call $p$-adic
pro-unipotent harmonic actions. These are continuous group actions on a space
containing the non-commutative generating series of weighted multiple harmonic
sums, they are related to the motivic Galois action on
$\pi_{1}^{\un}(\mathbb{P}^{1} - \{0,1,\infty\})$ and to the Poisson-Ihara
bracket, and interrelated by some maps. They are defined in \cite{J2} and
\cite{J3} ; the definition relies on a simplification of the differential
equation of the Frobenius, proved as a preliminary technical fact by \cite{J1}.
Part I (\cite{J1},\cite{J2},\cite{J3}) is an explicit computation of the
Frobenius of $\pi_{1}^{\un,\crys}(\mathbb{P}^{1} - \{0,1,\infty\})$, and in
particular of $p$MZV's. We give formulas which keep a track of the motivic
Galois action. Part II (\cite{J4},\cite{J5},\cite{J6}) is a study of the
algebraic properties of $p$MZV's brought together with the formulas of part I.
We state an explicit elementary version of the Galois theory of $p$MZV's.


title:
Non-vanishing Superpotentials in Heterotic String Theory and Discrete
  Torsion

abstract:
  We study the non-perturbative superpotential in E_8 x E_8 heterotic string
theory on a non-simply connected Calabi-Yau manifold X, as well as on its
simply connected covering space \tilde{X}. The superpotential is induced by the
string wrapping holomorphic, isolated, genus 0 curves. According to the residue
theorem of Beasley and Witten, the non-perturbative superpotential must vanish
in a large class of heterotic vacua because the contributions from curves in
the same homology class cancel each other. We point out, however, that in
certain cases the curves treated in the residue theorem as lying in the same
homology class, can actually have different area with respect to the physical
Kahler form and can be in different homology classes. In these cases, the
residue theorem is not directly applicable and the structure of the
superpotential is more subtle. We show, in a specific example, that the
superpotential is non-zero both on \tilde{X} and on X. On the non-simply
connected manifold X, we explicitly compute the leading contribution to the
superpotential from all holomorphic, isolated, genus 0 curves with minimal
area. The reason for the non-vanishing of the superpotental on X is that the
second homology class contains a finite part called discrete torsion. As a
result, the curves with the same area are distributed among different torsion
classes and, hence, do not cancel each other.


title:
Investigation of Carrier Recombination Dynamics of InGaP/InGaAsP
  Multiple Quantum Wells for Solar Cells via Photoluminescence

abstract:
  The carrier recombination dynamics of InGaP/InGaAsP quantum wells are
reported for the first time. By studying the photoluminescence (PL) and
time-resolved PL decay of InGaP/InGaAsP multiple-quantum-well(MQW)
heterostructure samples, it is demonstrated that InGaP/InGaAsP MQWs have very
low non-radiative recombination rate and high radiative efficiency compared to
the control InGaP sample. Along with the analyses of PL emission spectrum and
external quantum efficiencies, it suggests that this is due to small
confinement potentials in the conduction band but high confinement potentials
in the valence band. These results explain several features found in
InGaP/InGaAsP MQW solar cells previously.


title:
On the classification of quadratic forms over an integral domain of a
  global function field

abstract:
  Let $C$ be a smooth projective curve defined over the finite field
$\mathbb{F}_q$ ($q$ is odd) and let $K=\mathbb{F}_q(C)$ be its function field.
Any finite set $S$ of closed points of $C$ gives rise to an integral domain
$\mathcal{O}_S:=\mathbb{F}_q[C-S]$ in $K$. We show that given an
$\mathcal{O}_S$-regular quadratic space $(V,q)$ of rank $n \geq 3$, the set of
genera in the proper classification of quadratic $\mathcal{O}_S$-spaces
isomorphic to $(V,q)$ in the flat or \'etale topology, is in $1:1$
correspondence with ${_2\text{Br}}(\mathcal{O}_S)$, thus there are $2^{|S|-1}$
such. If $(V,q)$ is isotropic, then $\text{Pic}(\mathcal{O}_S)/2$ classifies
the forms in the genus of $(V,q)$. For $n \geq 5$ this is true for all genera,
hence the full classification is via the abelian group
$H^2_{\text{\'et}}(\mathcal{O}_S,\underline{\mu}_2)$.


title: Resummations in PDF fits

abstract:
  In this contribution I discuss recent and ongoing progress on the inclusion
of resummation effects in the fit of parton distributions.


title: On commuting probability of finite rings II

abstract:
  The aim of this paper is to study the probability that the commutator of an
arbitrarily chosen pair of elements, each from two different subrings of a
finite non-commutative ring equals a given element of that ring. We obtain
several results on this probability including a computing formula, some bounds
and characterizations.


title: Data Unfolding Methods in High Energy Physics

abstract:
  A selection of unfolding methods commonly used in High Energy Physics is
compared. The methods discussed here are: bin-by-bin correction factors, matrix
inversion, template fit, Tikhonov regularisation and two examples of iterative
methods. Two procedures to choose the strength of the regularisation are
tested, namely the L-curve scan and a scan of global correlation coefficients.
The advantages and disadvantages of the unfolding methods and choices of the
regularisation strength are discussed using a toy example.


title:
The Noncommutative Index Theorem and the Periodic Table for Disordered
  Topological Insulators and Superconductors

abstract:
  We study a wide class of topological free-fermion systems on a hypercubic
lattice in spatial dimensions $d\ge 1$. When the Fermi level lies in a spectral
gap or a mobility gap, the topological properties, e.g., the integral
quantization of the topological invariant, are protected by certain symmetries
of the Hamiltonian against disorder. This generic feature is characterized by a
generalized index theorem which is a noncommutative analogue of the
Atiyah-Singer index theorem. The noncommutative index defined in terms of a
pair of projections gives a precise formula for the topological invariant in
each symmetry class in any dimension ($d \ge 1$). Under the assumption on the
nonvanishing spectral or mobility gap, we prove that the index formula
reproduces Bott periodicity and all of the possible values of topological
invariants in the classification table of topological insulators and
superconductors. We also prove that the indices are robust against
perturbations that do not break the symmetry of the unperturbed Hamiltonian.

categories: math-ph cond-mat.dis-nn cond-mat.supr-con hep-lat hep-th math.MP


title:
Averaged-DQN: Variance Reduction and Stabilization for Deep
  Reinforcement Learning

abstract:
  Instability and variability of Deep Reinforcement Learning (DRL) algorithms
tend to adversely affect their performance. Averaged-DQN is a simple extension
to the DQN algorithm, based on averaging previously learned Q-values estimates,
which leads to a more stable training procedure and improved performance by
reducing approximation error variance in the target values. To understand the
effect of the algorithm, we examine the source of value function estimation
errors and provide an analytical comparison within a simplified model. We
further present experiments on the Arcade Learning Environment benchmark that
demonstrate significantly improved stability and performance due to the
proposed extension.


title: Eigenvalue bounds for the magnetic Laplacian

abstract:
  We consider a compact Riemannian manifold M endowed with a potential 1-form A
and study the magnetic Laplacian associated with those data (with Neumann
magnetic boundary condition if the bpoundary of M is not empty). We first
establish a family of upper bounds for all the eigenvalues, compatible with the
Weyl law. When the potential is a closed 1-form, we get a sharp upper bound for
the first eigenvalue. In the second part, we consider only closed potentials,
and we establish a sharp lower bound for the first eigenvalue when the manifold
is a 2-dimensional Riemannian cylinder. The equality case characterizes the
situation where the metric is a product. We also look at the case of doubly
convex domains in the Euclidean plane.


title: Topological K-theory of Equivariant Singularity Categories

abstract:
  We study the topological K-theory spectrum of the dg singularity category
associated to a weighted projective complete intersection. We calculate the
topological K-theory of the dg singularity category of a weighted projective
hypersurface in terms of its Milnor fiber and monodromy operator, and, as an
application, we obtain a lift of the Atiyah-Bott-Shapiro construction to the
level of spectra.


title:
Simple Floquet-Wannier-Stark-Andreev viewpoint and emergence of
  low-energy scales in a voltage-biased three-terminal Josephson junction

abstract:
  A three-terminal Josephson junction consists of three superconductors coupled
coherently to a small nonsuperconducting island, such as a diffusive metal, a
single or double quantum dot. A specific resonant single quantum dot
three-terminal Josephson junction $(S_a,S_b,S_c)$ biased with voltages
$(V,-V,0)$ is considered, but the conclusions hold more generally for resonant
semi-conducting quantum wire set-ups. A simple physical picture of the steady
state is developed, using Floquet theory. It is shown that the equilibrium
Andreev bound states (for $V=0$) evolve into nonequilibrium
Floquet-Wannier-Stark-Andreev (FWS-Andreev) ladders of resonances (for $V\ne
0$). These resonances acquire a finite width due to multiple Andreev reflection
(MAR) processes. We also consider the effect of an extrinsic line-width
broadening on the quantum dot, introduced through a Dynes phenomenological
parameter. The DC-quartet current manifests a cross-over between the extrinsic
relaxation dominated regime at low voltage to an intrinsic relaxation due to
MAR processes at higher voltage. Finally, we study the coupling between the two
FWS-Andreev ladders due to Landau-Zener-St\"uckelberg transitions, and its
effect on the cross-over in the relaxation mechanism. Three important
low-energy scales are identified, and a perspective is to relate those
low-energy scales to a recent noise cross-correlation experiment [Y. Cohen {\it
et al.}, arXiv:1606.08436].


title:
Assessing composition gradients in multifilamentary superconductors by
  means of magnetometry methods

abstract:
  We present two magnetometry-based methods suitable for assessing gradients in
the critical temperature and hence the composition of multifilamentary
superconductors: AC magnetometry and Scanning Hall Probe Microscopy. The
novelty of the former technique lies in the iterative evaluation procedure we
developed, whereas the strength of the latter is the direct visualization of
the temperature dependent penetration of a magnetic field into the
superconductor. Using the example of a PIT Nb3Sn wire, we demonstrate the
application of these techniques, and compare the respective results to each
other and to EDX measurements of the Sn distribution within the sub-elements of
the wire.


title: On the Configuration-LP of the Restricted Assignment Problem

abstract:
  We consider the classical problem of Scheduling on Unrelated Machines. In
this problem a set of jobs is to be distributed among a set of machines and the
maximum load (makespan) is to be minimized. The processing time $p_{ij}$ of a
job $j$ depends on the machine $i$ it is assigned to. Lenstra, Shmoys and
Tardos gave a polynomial time $2$-approximation for this problem. In this paper
we focus on a prominent special case, the Restricted Assignment problem, in
which $p_{ij}\in\{p_j,\infty\}$. The configuration-LP is a linear programming
relaxation for the Restricted Assignment problem. It was shown by Svensson that
the multiplicative gap between integral and fractional solution, the
integrality gap, is at most $2 - 1/17 \approx 1.9412$. In this paper we
significantly simplify his proof and achieve a bound of $2 - 1/6 \approx
1.8333$. As a direct consequence this provides a polynomial $(2 - 1/6 +
\epsilon)$-estimation algorithm for the Restricted Assignment problem by
approximating the configuration-LP. The best lower bound known for the
integrality gap is $1.5$ and no estimation algorithm with a guarantee better
than $1.5$ exists unless $\mathrm{P} = \mathrm{NP}$.


title:
Skewness of citation impact data and covariates of citation
  distributions: A large-scale empirical analysis based on Web of Science data

abstract:
  Using percentile shares, one can visualize and analyze the skewness in
bibliometric data across disciplines and over time. The resulting figures can
be intuitively interpreted and are more suitable for detailed analysis of the
effects of independent and control variables on distributions than regression
analysis. We show this by using percentile shares to analyze so-called "factors
influencing citation impact" (FICs; e.g., the impact factor of the publishing
journal) across year and disciplines. All articles (n= 2,961,789) covered by
WoS in 1990 (n= 637,301), 2000 (n= 919,485), and 2010 (n= 1,405,003) are used.
In 2010, nearly half of the citation impact is accounted for by the 10%
most-frequently cited papers; the skewness is largest in the humanities (68.5%
in the top-10% layer) and lowest in agricultural sciences (40.6%). The
comparison of the effects of the different FICs (the number of cited
references, number of authors, number of pages, and JIF) on citation impact
shows that JIF has indeed the strongest correlations with the citation scores.
However, the correlation between FICs and citation impact is lower, if
citations are normalized instead of using raw citation counts.


title:
Discrimination of Graph Isomorphism Classes by Continuous Spectrum and
  Split Technique

abstract:
  The graph isomorphism problem is a main problem which has numerous
applications in different fields. Thus, finding an efficient and easy to
implement method to discriminate non-isomorphic graphs is valuable. In this
paper, a new method is introduced which is very simple and easy to implement,
but very efficient in discriminating non-isomorphic graphs, in practice. This
method does not need any heuristic attempt and based on the eigenvalues of a
new matrix representation for graphs. It, almost always, separates
non-isomorphic $n$-vertex graphs in time $O(n^3)$ and in worst cases such as
strongly regular graphs, in time $O(n^4)$. Here, we show that this method,
successfully, characterizes the isomorphism classes of studied instances of
strongly regular graphs (up to 64 vertices). Strongly regular graphs are
believed to be hard cases of the graph isomorphism problem.


title: Matrix Algebras over Strongly Non-Singular Rings

abstract:
  We consider some existing results regarding rings for which the classes of
torsion-free and non-singular right modules coincide. Here, a right $R$-module
$M$ is non-singular if $xI$ is nonzero for every nonzero $x \in M$ and every
essential right ideal $I$ of $R$, and a right $R$-module $M$ is torsion-free if
$Tor_{1}^{R}(M,R / Rr)=0$ for every $r \in R$. In particular, we consider a
ring $R$ for which the classes of torsion-free and non-singular right
$S$-modules coincide for every ring $S$ Morita-equivalent to $R$. We make use
of these results, as well as the existence of a Morita-equivalence between a
ring $R$ and the $n \times n$ matrix ring $Mat_{n}(R)$, to characterize rings
whose $n \times n$ matrix ring is a Baer-ring. A ring is Baer if every right
(or left) annihilator is generated by an idempotent. Semi-hereditary, strongly
non-singular, and Utumi rings will play an important role, and we explore these
concepts and relevant results as well.


title: Constructions of graphs and trees with partially prescribed spectrum

abstract:
  It is shown how a connected graph and a tree with partially prescribed
spectrum can be constructed. These constructions are based on a recent result
of Salez that every totally real algebraic integer is an eigenvalue of a tree.
Our result implies that for any (not necessarily connected) graph $G$, there is
a tree $T$ such that the characteristic polynomial $P(G,x)$ of $G$ can divide
the characteristic polynomial $P(T,x)$ of $T$, i.e., $P(G,x)$ is a divisor of
$P(T,x)$.


title:
Artificial-Noise-Aided Secure Transmission in Wiretap Channels with
  Transmitter-Side Correlation

abstract:
  This work for the first time examines the impact of transmitter-side
correlation on the artificial-noise-aided secure transmission, based on which a
new power allocation strategy for artificial noise (AN) is devised for physical
layer security enhancement. Specifically, we design a correlation-based power
allocation (CPA) for AN, of which the optimality in terms of achieving the
minimum secrecy outage probability is analytically proved in the large system
regime with the number of transmit antennas approaching infinity. In order to
fully reveal the benefits of the CPA, we derive easy-to-evaluate expressions
for the secrecy outage probability achieved by the CPA. Our study demonstrates
that the CPA is nearly optimal and significantly outperforms the widely-used
uniform power allocation (UPA) even for a moderately small number of correlated
transmit antennas. Furthermore, our numerical results reveal a fundamental
difference between the CPA and UPA. That is when the number of correlated
transmit antennas increases, the secrecy outage probability of the CPA always
reduces while the secrecy outage probability of the UPA suffers from a
saturation point.


title:
A chain rule formula for higher derivations and inverses of polynomial
  maps

abstract:
  The multidimensional chain rule formula for analytic functions and its
generalisation to higher derivatives perfectly work in the algebraic setting in
characteristic zero. In positive characteristic one runs into problems due to
denominators in these formulas. In this article we show a direct analog of
these formulas using higher derivations which are defined in any
characteristic. We also use these formulas to show how higher derivations to
different coordinate systems are related to each other. Finally, we apply this
to polynomial automorphisms in arbitrary characteristic and obtain a formula
for the inverse of such a polynomial automorphism.


title: The Beraha number $B_{10}$ is a chromatic root

abstract:
  This note exhibits graphs whose chromatic polynomials have the Beraha number
$B_{10} = (5 + \sqrt{5})/2$ as a root. It was previously known that no other
non-integer Beraha number is a chromatic root, and so these examples complete
the determination of precisely which Beraha numbers can be chromatic roots.


title:
DeepSense: A Unified Deep Learning Framework for Time-Series Mobile
  Sensing Data Processing

abstract:
  Mobile sensing applications usually require time-series inputs from sensors.
Some applications, such as tracking, can use sensed acceleration and rate of
rotation to calculate displacement based on physical system models. Other
applications, such as activity recognition, extract manually designed features
from sensor inputs for classification. Such applications face two challenges.
On one hand, on-device sensor measurements are noisy. For many mobile
applications, it is hard to find a distribution that exactly describes the
noise in practice. Unfortunately, calculating target quantities based on
physical system and noise models is only as accurate as the noise assumptions.
Similarly, in classification applications, although manually designed features
have proven to be effective, it is not always straightforward to find the most
robust features to accommodate diverse sensor noise patterns and user
behaviors. To this end, we propose DeepSense, a deep learning framework that
directly addresses the aforementioned noise and feature customization
challenges in a unified manner. DeepSense integrates convolutional and
recurrent neural networks to exploit local interactions among similar mobile
sensors, merge local interactions of different sensory modalities into global
interactions, and extract temporal relationships to model signal dynamics.
DeepSense thus provides a general signal estimation and classification
framework that accommodates a wide range of applications. We demonstrate the
effectiveness of DeepSense using three representative and challenging tasks:
car tracking with motion sensors, heterogeneous human activity recognition, and
user identification with biometric motion analysis. DeepSense significantly
outperforms the state-of-the-art methods for all three tasks. In addition,
DeepSense is feasible to implement on smartphones due to its moderate energy
consumption and low latency


title:
The exact phase diagram for a class of multispecies asymmetric exclusion
  processes

abstract:
  The asymmetric exclusion process is an idealised stochastic model of
transport, whose exact solution has given important insight into a general
theory of nonequilibrium statistical physics. In this work, we consider a
totally asymmetric exclusion process with multiple species of particles on a
one-dimensional lattice in contact with reservoirs. We derive the exact
nonequilibrium phase diagram for the system in the long time limit. We find two
new phenomena in certain regions of the phase diagram: when the density of a
species becomes zero throughout the system, and dynamical localisation when the
density of a species is nonzero only within an interval far from the
boundaries. We give a complete explanation of the macroscopic features of the
phase diagram using what we call nested fat shocks.

categories: cond-mat.stat-mech math-ph math.CO math.MP math.PR


title:
Optimal Drift Rate Control and Impulse Control for a Stochastic
  Inventory/Production System

abstract:
  In this paper, we consider joint drift rate control and impulse control for a
stochastic inventory system under long-run average cost criterion. Assuming the
inventory level must be nonnegative, we prove that a
$\{(0,q^{\star},Q^{\star},S^{\star}),\{\mu^{\star}(x): x\in[0, S^{\star}]\}\}$
policy is an optimal joint control policy, where the impulse control follows
the control band policy $(0,q^{\star},Q^{\star},S^{\star})$, that brings the
inventory level up to $q^{\star}$ once it drops to $0$ and brings it down to
$Q^{\star}$ once it rises to $S^{\star}$, and the drift rate only depends on
the current inventory level and is given by function $\mu^{\star}(x)$ for the
inventory level $x\in[0,S^{\star}]$. The optimality of the
$\{(0,q^{\star},Q^{\star},S^{\star}),\{\mu^{\star}(x): x\in[0,S^{\star}]\}\}$
policy is proven by using a lower bound approach, in which a critical step is
to prove the existence and uniqueness of optimal policy parameters. To prove
the existence and uniqueness, we develop a novel analytical method to solve a
free boundary problem consisting of an ordinary differential equation (ODE) and
several free boundary conditions. Furthermore, we find that the optimal drift
rate $\mu^{\star}(x)$ is firstly increasing and then decreasing as $x$
increases from $0$ to $S^{\star}$ with a turnover point between $Q^{\star}$ and
$S^{\star}$.


title: Western Mathematics in China from the 16th to the 20th Century

abstract:
  From the 16th to the 20th century, Western mathematics had a dramatic impact
in China. Firstly they triggered lexical developments, e.g. in the field of
geometry. Later, in the 19the century, even though Li Shanlan had invented his
own system of algebraic notations, however Western ones were enventually
adopted.


title: Fractions in the Suan Shu Shu (China, Beginning of the 2nd Century BCE)

abstract:
  The Su{\`a}n Sh{\`u} Sh{\=u} contains 301 instances of regular expressions
for fractions. They can be "mono-dimensional" (formed with one integer name
only) for unit fractions, "bidimensional" (with two integer names) for both
unit and non-unit fractions, or lexicalized only for 1/3, 1/2 and 2/3. The
present paper gives a complete description of the diversity of these forms.
Bidimensional expressions are predicative phrases: the name n f{\=e}n of a unit
fraction 1/n acts as subject and the numerator's name as predicate; according
to the syntactic context, the morpheme zh{\=i} can be used as an optional
marker of this predicative relation.


title:
SPECTRA -- a Maple library for solving linear matrix inequalities in
  exact arithmetic

abstract:
  This document describes our freely distributed Maple library {\sc spectra},
for Semidefinite Programming solved Exactly with Computational Tools of Real
Algebra. It solves linear matrix inequalities with symbolic computation in
exact arithmetic and it is targeted to small-size, possibly degenerate problems
for which symbolic infeasibility or feasibility certificates are required.


title: GRB Observational Properties

abstract:
  We summarize basic observational properties of gamma-ray bursts (GRBs),
including prompt emission properties, afterglow properties, and classification
schemes. We also briefly comment on the current physical understanding of these
properties.


title: The fractal nature of an approximate prime counting function

abstract:
  Prime number related fractal polygons and curves are derived by combining two
different aspects. One is an approximation of the prime counting function build
on an additive function. The other are prime number indexed basis entities
taken from the discrete or continuous Fourier basis.


title: Pilot Precoding and Combining in Multiuser MIMO Networks

abstract:
  Although the benefits of precoding and combining of data signals are widely
recognized, the potential of these techniques for pilot transmission is not
fully understood. This is particularly relevant for multiuser multiple-input
multiple-output (MU-MIMO) cellular systems using millimeter-wave (mmWave)
communications, where multiple antennas will have to be used both at the
transmitter and the receiver to overcome the severe path loss. In this paper,
we characterize the gains of pilot precoding and combining in terms of channel
estimation quality and achievable data rate. Specifically, we consider three
uplink pilot transmission scenarios in a mmWave MU-MIMO cellular system: 1)
non-precoded and uncombined, 2) precoded but uncombined, and 3) precoded and
combined. We show that a simple precoder that utilizes only the second-order
statistics of the channel reduces the variance of the channel estimation error
by a factor that is proportional to the number of user equipment (UE) antennas.
We also show that using a linear combiner designed based on the second-order
statistics of the channel significantly reduces multiuser interference and
provides the possibility of reusing some pilots. Specifically, in the large
antenna regime, pilot precoding and combining help to accommodate a large
number of UEs in one cell, significantly improve channel estimation quality,
boost the signal-to-noise ratio of the UEs located close to the cell edges,
alleviate pilot contamination, and address the imbalanced coverage of pilot and
data signals.


title:
Gender Differences in Undergraduate Physics Courses: A Comparative Study
  of Persistence

abstract:
  We have investigated the difference in persistence between male and female
students while taking undergraduatephysics courses. To quantify the persistence
of a certain group of students, we have defined 'persistence index' as the
inverseof the decrease rate of the number of that group of students while
taking a specific course. We have collected the data fromthree consecutive
workshops on various topics of physics. After plotting the number of
participations against the number ofdays attended, we have calculated the
decrease rates and persistence indices for both male and female student groups
on eachworkshop and compared the persistence indices on a bar diagram. The
comparative statistics show that the persistence indicesof female student
groups are significantly higher than that of male student groups. This leads us
to the conclusion that thefemale students are more persistent than male
students while taking an undergraduate physics course.