title: Vortex-bright solitons in a spin-orbit coupled spin-$1$ condensate

abstract:
  We study the vortex-bright solitons in a quasi-two-dimensional
spin-orbit-coupled (SO-coupled) hyperfine spin-1 three-component Bose-Einstein
condensate (BEC) using variational method and numerical solution of a
mean-field model. The ground state of these vortex-bright solitons is radially
symmetric for weak ferromagnetic and polar interactions. For a sufficiently
strong ferromagnetic interaction, we observe the emergence of an asymmetric
vortex-bright soliton as the ground state. We also numerically investigate
stable moving solitons and binary collision between them. The present
mean-field model is not Galilean invariant, and we use a Galilean-transformed
model for generating the moving solitons. At low velocities, the head-on
collision between two {\em in-phase} solitons results either in collapse or
fusion of the soliton pair. On the other hand, in head-on collision, the two
{\em out-of-phase} solitons strongly repel each other and trace back their
trajectories before the actual collision. At low velocities, in a collision
with an impact parameter, the {\em out-of-phase} solitons get deflected from
their original trajectory like two rigid classical disks. These {\em
out-of-phase solitons} behave like classical disks, and their collision
dynamics is governed by classical laws of motion. However, at large velocities
two SO-coupled spinor solitons, irrespective of phase difference, can pass
through each other in a head-on collision like two quantum solitons.


title: On quasi-categories of comodules and Landweber exactness

abstract:
  In this paper we study quasi-categories of comodules over coalgebras in a
stable homotopy theory. We show that the quasi-category of comodules over the
coalgebra associated to a Landweber exact S-algebra depends only on the height
of the associated formal group. We also show that the quasi-category of
E(n)-local spectra is equivalent to the quasi-category of comodules over the
coalgebra A\otimes A for any Landweber exact S_(p)-algebra A of height n at a
prime p. Furthermore, we show that the category of module objects over a
discrete model of the Morava E-theory spectrum in the K(n)-local discrete
symmetric G_n-spectra is a model of the K(n)-local category, where G_n is the
extended Morava stabilizer group.


title: A Character-Word Compositional Neural Language Model for Finnish

abstract:
  Inspired by recent research, we explore ways to model the highly
morphological Finnish language at the level of characters while maintaining the
performance of word-level models. We propose a new
Character-to-Word-to-Character (C2W2C) compositional language model that uses
characters as input and output while still internally processing word level
embeddings. Our preliminary experiments, using the Finnish Europarl V7 corpus,
indicate that C2W2C can respond well to the challenges of morphologically rich
languages such as high out of vocabulary rates, the prediction of novel words,
and growing vocabulary size. Notably, the model is able to correctly score
inflectional forms that are not present in the training data and sample
grammatically and semantically correct Finnish sentences character by
character.


title:
Generalized Fractional Kinetic Equations Involving the generalized
  modified $k$-Bessel function

abstract:
  Fractional kinetic equations are investigated in order to describe the
various phenomena governed by anomalous reaction in dynamical systems with
chaotic motion. Many authors have provided solutions for various families of
fractional kinetic equations involving special functions. Here, in this paper,
we aim at presenting solutions of certain general families of fractional
kinetic equations associated with the generalized modified $k$-Bessel function
of the first kind. It is also pointed out that the main results presented here
are general enough to be able to be specialized to yield many known and
(presumably) new solutions for fractional kinetic equations.


title: Generalized Deep Image to Image Regression

abstract:
  We present a Deep Convolutional Neural Network architecture which serves as a
generic image-to-image regressor that can be trained end-to-end without any
further machinery. Our proposed architecture: the Recursively Branched
Deconvolutional Network (RBDN) develops a cheap multi-context image
representation very early on using an efficient recursive branching scheme with
extensive parameter sharing and learnable upsampling. This multi-context
representation is subjected to a highly non-linear locality preserving
transformation by the remainder of our network comprising of a series of
convolutions/deconvolutions without any spatial downsampling. The RBDN
architecture is fully convolutional and can handle variable sized images during
inference. We provide qualitative/quantitative results on $3$ diverse tasks:
relighting, denoising and colorization and show that our proposed RBDN
architecture obtains comparable results to the state-of-the-art on each of
these tasks when used off-the-shelf without any post processing or
task-specific architectural modifications.


title: Demystifying the compressed top squark region with kinematic variables

abstract:
  The ongoing perplexing scenario with no hints of new physics at the Large
Hadron Collider can be elucidated amicably if the exotic particle spectrum in
many of the well-motivated theoretical models possesses degenerate mass. We
investigate the usefulness of different kinematic variables sensitive to the
compressed mass region, and propose a search strategy considering a
phenomenological supersymmetric scenario where the top squark undergoes a
four-body decay due to its extremely narrow mass difference with the lightest
supersymmetric particle. Considering a challenging but relatively clean
dileptonic decay channel, we demonstrate that one can effectively restrain the
significant background from the top quark, which provides a complementary
approach to the present CMS analysis. With the new strategic approach the
current limit can be extended to a phase-space region that was not explored
before.


title: Hebbian Plasticity for Improving Perceptual Decisions

abstract:
  Shibata et al. reported that humans could learn to repeatedly evoke a
stimulus-associated functional magnetic resonance imaging (fMRI) activity
pattern in visual areas V1/V2 through which visual perceptual learning was
achieved without stimulus presentation. Contrary to their attribution of visual
improvements to neuroplasticity in adult V1/V2, our Hebbian learning
interpretation of these data explains the attainment of better perceptual
decisions without plastic V1/V2.


title:
Optimal Design of Energy and Spectral Efficiency Tradeoff in One-Bit
  Massive MIMO Systems

abstract:
  This paper considers a single-cell massive multiple-input multiple-output
(MIMO) system equipped with a base station (BS) that uses one-bit quantization
and investigates the energy efficiency (EE) and spectral efficiency (SE)
trade-off. We first propose a new precoding scheme and downlink power
allocation strategy that results in uplink-downlink SINR duality for one-bit
MIMO systems. Taking into account the effect of the imperfect channel state
information, we obtain approximate closed-form expressions for the uplink and
downlink achievable rates under duality with maximum ratio
combining/matched-filter and zero-forcing processing. We then focus on joint
optimization of the competing SE and EE objectives over the number of users,
pilot training duration and operating power, using the weighted product method
to obtain the EE/SE Pareto boundary. Numerical results are presented to verify
our analytical resultsand demonstrate the fundamental tradeoff between EE and
SE for different parameter settings.


title:
Integral formulas for a metric-affine manifold with two complementary
  orthogonal distributions

abstract:
  We obtain integral formulas for a metric-affine space equipped with two
complementary orthogonal distributions. The integrand depends on the Ricci and
mixed scalar curvatures and invariants of the second fundamental forms and
integrability tensors of the distributions. The formulas under some conditions
yield splitting of manifolds (including submersions and twisted products) and
provide geometrical obstructions for existence of distributions and foliations
(or compact leaves of them).


title: Towards an Automated Image De-fencing Algorithm Using Sparsity

abstract:
  Conventional approaches to image de-fencing suffer from non-robust fence
detection and are limited to processing images of static scenes. In this
position paper, we propose an automatic de-fencing algorithm for images of
dynamic scenes. We divide the problem of image de-fencing into the tasks of
automated fence detection, motion estimation and fusion of data from multiple
frames of a captured video of the dynamic scene. Fences are detected
automatically using two approaches, namely, employing Gabor filter and a
machine learning method. We cast the fence removal problem in an optimization
framework, by modeling the formation of the degraded observations. The inverse
problem is solved using split Bregman technique assuming total variation of the
de-fenced image as the regularization constraint.


title: Comparative analysis of Debrecen sunspot catalogues

abstract:
  Sunspot area data are important for studying solar activity and its long term
variations. At the Debrecen Heliophysical Observatory, we compiled three
sunspot catalogues: the Debrecen Photoheliographic Data (DPD), the SDO/HMI
Debrecen Data (HMIDD), and the SOHO/MDI Debrecen Data. For comparison, we also
compiled an additional sunspot catalogue, the Greenwich Photoheliographic Data,
from the digitized Royal Greenwich Observatory images for the 1974-76. By
comparing these catalogues when they overlap in time, we can investigate how
various factors influence the measured area of the sunspots, and, in addition,
we can derive area cross-calibration factors for these catalogues.The main
findings are as follows. The poorer seeing increases the individual corrected
spot areas and decreases the number of the small spots. Interestingly, the net
result of these two effects for the total corrected spot area is zero. DPD
daily total corrected sunspot areas are 5 per cent smaller than the HMIDD ones.
Revised DPD daily total corrected umbra areas are 9 per cent smaller than those
of HMIDD. The Greenwich Photoheliographic Result areas are only a few per cent
smaller than DPD areas. A $0.2^{\circ}$ difference between the North directions
of the DPD and MDI images is found. This value is nearly the same as that was
found ($0.22^{\circ}$) by us in a previous paper comparing HMI and MDI images.
The Solar Observing Optical Network area measurement practice (spots smaller
than $10 mh$ were not directly measured but an area of $2 mh$ were assigned to
each) can not explain the large area deficit of the Solar Observing Optical
Network.


title:
Optical photometry and spectroscopy of the low-luminosity, broad-lined
  Ic supernova iPTF15dld

abstract:
  Core-collapse stripped-envelope supernova (SN) explosions reflect the
diversity of physical parameters and evolutionary paths of their massive star
progenitors. We have observed the type Ic SN iPTF15dld (z = 0.047), reported by
the Palomar Transient Factory. Spectra were taken starting 20 rest-frame days
after maximum luminosity and are affected by a young stellar population
background. Broad spectral absorption lines associated with the SN are detected
over the continuum, similar to those measured for broad-lined, highly energetic
SNe Ic. The light curve and maximum luminosity are instead more similar to
those of low luminosity, narrow-lined Ic SNe. This suggests a behavior whereby
certain highly-stripped-envelope SNe do not produce a large amount of Ni56, but
the explosion is sufficiently energetic that a large fraction of the ejecta is
accelerated to higher-than-usual velocities. We estimate SN iPTF15dld had a
main sequence progenitor of 20-25 Msun, produced a Ni56 mass of ~0.1-0.2 Msun,
had an ejecta mass of [2-10] Msun, and a kinetic energy of [1-18] e51 erg.


title:
Link between Alhassid-Levine and Hioe-Eberly formalisms of $SU(N)$
  equation of motion

abstract:
  Geometric representations of solutions provides intuitive physical insights.
To which end studying dynamics of Quantum systems via $su (n)$ Lie algebra
proves to be convenient way of obtaining geometric solution. In this paper link
is established between two formalisms that made use of Lie algebra to describe
equation of motion for quantum system. In both approaches the Hamiltonian and
the density matrix are expressed as a linear combination of the Lie group. To
exemplify the approach we consider a very well studied two level system coupled
by a laser pulse. Beyond establishing link between these two formalism we
obtained two constants of motion by assuming time dependent detuning whose time
profile is assumed to be same as the laser pulse. Consequently we have shown
how one can have two disjoint subspaces whose evolution vector is independent
of each other.


title: Data Curation APIs

abstract:
  Understanding and analyzing big data is firmly recognized as a powerful and
strategic priority. For deeper interpretation of and better intelligence with
big data, it is important to transform raw data (unstructured, semi-structured
and structured data sources, e.g., text, video, image data sets) into curated
data: contextualized data and knowledge that is maintained and made available
for use by end-users and applications. In particular, data curation acts as the
glue between raw data and analytics, providing an abstraction layer that
relieves users from time consuming, tedious and error prone curation tasks. In
this context, the data curation process becomes a vital analytics asset for
increasing added value and insights.
  In this paper, we identify and implement a set of curation APIs and make them
available (on GitHub) to researchers and developers to assist them transforming
their raw data into curated data. The curation APIs enable developers to easily
add features - such as extracting keyword, part of speech, and named entities
such as Persons, Locations, Organizations, Companies, Products, Diseases,
Drugs, etc.; providing synonyms and stems for extracted information items
leveraging lexical knowledge bases for the English language such as WordNet;
linking extracted entities to external knowledge bases such as Google Knowledge
Graph and Wikidata; discovering similarity among the extracted information
items, such as calculating similarity between string, number, date and time
data; classifying, sorting and categorizing data into various types, forms or
any other distinct class; and indexing structured and unstructured data - into
their applications.


title:
Improved prediction accuracy for disease risk mapping using Gaussian
  Process stacked generalisation

abstract:
  Maps of infectious disease---charting spatial variations in the force of
infection, degree of endemicity, and the burden on human health---provide an
essential evidence base to support planning towards global health targets.
Contemporary disease mapping efforts have embraced statistical modelling
approaches to properly acknowledge uncertainties in both the available
measurements and their spatial interpolation. The most common such approach is
that of Gaussian process regression, a mathematical framework comprised of two
components: a mean function harnessing the predictive power of multiple
independent variables, and a covariance function yielding spatio-temporal
shrinkage against residual variation from the mean. Though many techniques have
been developed to improve the flexibility and fitting of the covariance
function, models for the mean function have typically been restricted to simple
linear terms. For infectious diseases, known to be driven by complex
interactions between environmental and socio-economic factors, improved
modelling of the mean function can greatly boost predictive power. Here we
present an ensemble approach based on stacked generalisation that allows for
multiple, non-linear algorithmic mean functions to be jointly embedded within
the Gaussian process framework. We apply this method to mapping Plasmodium
falciparum prevalence data in Sub-Saharan Africa and show that the generalised
ensemble approach markedly out-performs any individual method.


title: Graph based linear error correcting codes

abstract:
  In this article we present a construction of error correcting codes, that
have representation as very sparse matrices and belong to the class of Low
Density Parity Check Codes. LDPC codes are in the classical Hamming metric.
They are very close to well known Shannon bound. The ability to use graphs for
code construction was first discussed by Tanner in 1981 and has been used in a
number of very effective implementations. We describe how to construct such
codes by using special a family of graphs introduced by Ustimenko and Woldar.
Graphs that we used are bipartite, bi-regular, very sparse and do not have
short cycles C 4 . Due to the very low density of such graphs, the obtained
codes are fast decodable. We describe how to choose parameters to obtain a
desired code rate. We also show results of computer simulations of BER (bit
error rate) of the obtained codes in order to compare them with other known
LDPC codes.


title: Coloring problem of signed interval graphs

abstract:
  The chromatic number of signed graphs is defined recently. The coloring and
clique problem of interval graphs has been studied and polynomial time
algorithms are established. Here we consider these problems for signed interval
graphs and prove that the coloring problem of signed interval graphs is
NP-complete whereas their ordinary clique problem is in P. We also study the
complexity of further related problems.


title: Random walks and diffusion on networks

abstract:
  Random walks are ubiquitous in the sciences, and they are interesting from
both theoretical and practical perspectives. They are one of the most
fundamental types of stochastic processes; can be used to model numerous
phenomena, including diffusion, interactions, and opinions among humans and
animals; and can be used to extract information about important entities or
dense groups of entities in a network. Random walks have been studied for many
decades on both regular lattices and (especially in the last couple of decades)
on networks with a variety of structures. In the present article, we survey the
theory and applications of random walks on networks, restricting ourselves to
simple cases of single and non-adaptive random walkers. We distinguish three
main types of random walks: discrete-time random walks, node-centric
continuous-time random walks, and edge-centric continuous-time random walks. We
first briefly survey random walks on a line, and then we consider random walks
on various types of networks. We extensively discuss applications of random
walks, including ranking of nodes (e.g., PageRank), community detection,
respondent-driven sampling, and opinion models such as voter models.


title:
Some remarks on derivations on the algebra of operators in Hilbert
  pro-C*-bimodules

abstract:
  Suppose $A$ is a pro-C*-algebra. Let $L_{A}(E)$ be the pro-C*-algebra of
adjointable operators on a Hilbert $A$-module $E$ and let $K_{A}(E)$ be the
closed two sided $*$-ideal of all compact operators on $E$. We prove that if
$E$ be a full Hilbert $A$-module, the innerness of derivations on $K_{A}(E)$
implies the innerness of derivations on $L_{A}(E)$. We show that if $A$ is a
commutative pro-C*-algebra and $E$ is a Hilbert $A$-bimodule then every
derivation on $K_{A}(E)$ is zero. Moreover, if $A$ is a commutative
$\sigma$-C*-algebra and $E$ is a Hilbert $A$-bimodule then every derivation on
$L_{A}(E)$ is zero, too.


title:
Records of sunspot and aurora activity during 581-959 CE in Chinese
  official histories in the periods of Su\'i, T\'ang, and the Five Dynasties
  and Ten Kingdoms

abstract:
  Recent studies of radioisotopes in tree rings or ice cores suggest that
extreme space weather events occurred in the pre-telescope age. Observational
records of naked-eye sunspots and low-latitude auroras in historical documents
in pre-telescopic age can provide useful information on past solar activity. In
this paper, we present the results of a comprehensive survey of records of
sunspots and auroras in Chinese official histories from the 6th century to the
10th century, in the period of Su\'i, T\'ang, the Five Dynasties and Ten
Kingdoms. These official histories contain records of continuous observations
with well-formatted reports conducted under the policy of the government. A
brief comparison of the frequency of observations of sunspots and auroras with
the observations of radioisotopes as an indicator of solar activity during the
corresponding periods is provided. Based on our data, we survey and compile the
records of sunspots and auroras in historical documents from variouslocations
and in several languages, and ultimately provide these as open data to the
scientific community.


title: Salient Object Detection with Convex Hull Overlap

abstract:
  Salient object detection plays an important part in a vision system to detect
important regions. Convolutional neural network (CNN) based methods directly
train their models with large-scale datasets, but what is the crucial feature
for saliency is still a problem. In this paper, we establish a novel bottom-up
feature named convex hull overlap (CHO), combining with appearance contrast
features, to detect salient objects. CHO feature is a kind of enhanced Gestalt
cue. Psychologists believe that surroundedness reflects objects overlap
relationship. An object which is on the top of the others is attractive. Our
method significantly differs from other earlier works in (1) We set up a
hand-crafted feature to detect salient object that our model does not need to
be trained by large-scale datasets; (2) Previous works only focus on appearance
features, while our CHO feature makes up the gap between the spatial object
covering and the object's saliency. Our experiments on a large number of public
datasets have obtained very positive results.


title:
Conceptual difficulties in the use of statistical inference in citation
  analysis

abstract:
  In this comment, I discuss the use of statistical inference in citation
analysis. In a recent paper, Williams and Bornmann argue in favor of the use of
statistical inference in citation analysis. I present a critical analysis of
their arguments and of similar arguments provided elsewhere in the literature.
My conclusion is that the use of statistical inference in citation analysis
involves major conceptual difficulties and, consequently, that the usefulness
of statistical inference in citation analysis is highly questionable.


title:
Gaussian fluctuations for edge counts in high-dimensional random
  geometric graphs

abstract:
  Consider a stationary Poisson point process in $\mathbb{R}^d$ and connect any
two points whenever their distance is less than or equal to a prescribed
distance parameter. This construction gives rise to the well known random
geometric graph. The number of edges of this graph is counted that have
midpoint in the $d$-dimensional unit ball. A quantitative central limit theorem
for this counting statistic is derived, as the space dimension $d$ and the
intensity of the Poisson point process tend to infinity simultaneously.


title: Atiyah-J\"anich theorem for $\sigma$-C*-algebras

abstract:
  K-theory for $ \sigma$-C*-algebras (countable inverse limits of C*-algebras)
has been investigated by N. C. Phillips [{\it K-Theory} {\bf 3} (1989),
441--478]. We use his representable K-theory to show that the space of Fredholm
modular operators with coefficients in an arbitrary unital $ \sigma$-C*-algebra
$A$, represents the functor $X \mapsto {\rm RK}_{0}(C(X, A))$ from the category
of countably compactly generated spaces to the category of abelian groups.


title:
Calculation of density of states of transition metals: from bulk sample
  to nanocluster

abstract:
  The technique is presented of restoring the electronic density of states of
the valence band from data of X-ray photoelectron spectroscopy. The originality
of the technique consists in using a stochastic procedure to solve an integral
equation relating the density of states and the experimental X-ray
photoelectron spectra. The results are presented for bulk sample of gold and
nanoclusters of tantalum; the possibility of using the results to determine the
density of states of low-dimensional structures, including ensembles of metal
nanoclusters, is demonstrated.


title: Configurational entropy of anti-de Sitter black holes

abstract:
  Recent studies indicate that the configurational entropy is an useful tool to
investigate the stability and (or) the relative dominance of states for diverse
physical systems. Recent examples comprise the connection between the variation
of this quantity and the relative fraction of light mesons and glueballs
observed in hadronic processes. Here we develop a technique for defining a
configurational entropy for an AdS-Schwarzschild black hole. The achieved
result corroborates consistency with the Hawking-Page phase transition. Namely,
the dominance of the black hole configurational entropy will be shown to
increase with the temperature. In order to verify the consistency of the new
procedure developed here, we also consider the case of black holes in flat
space-time. For such a black hole, it is known that evaporation leads to
instability. The configurational entropy obtained for the flat space case is
thoroughly consistent with the physical expectation. In fact, we show that the
smaller the black holes, the more unstable they are. So, the configurational
entropy furnishes a reliable measure for stability of black holes.


title: BMS Supertranslations and Memory in Four and Higher Dimensions

abstract:
  We consider the memory effect in even dimensional spacetimes of dimension $d
\ge 4$ arising from a burst of gravitational radiation. When $d=4$, the natural
frames in the stationary eras before and after the burst differ by the
composition of a boost and supertranslation, and this supertranslation
characterizes the "memory effect," i.e., the permanent displacement of test
particles near infinity produced by the radiation burst. However, we show that
when $d > 4$, this supertranslation and the corresponding memory effect vanish.
Consequently, when $d >4$, it is natural to impose stronger asymptotic
conditions at null infinity that reduce the asymptotic symmetry group to the
Poincare group. Conversely, when $d=4$, the asymptotic symmetry group at null
infinity must be taken to be the BMS group.


title:
$\tau^-\to\eta^{(\prime)}\pi^-\nu_\tau \gamma$ decays as backgrounds in
  the search for second class currents

abstract:
  Observation of $\tau^-\to\eta^{(\prime)}\pi^-\nu_\tau $ decays at Belle-II
would indicate either a manifestation of isospin symmetry breaking or genuine
second class currents (SCC) effects. The corresponding radiative
$\tau^-\to\eta^{(\prime)}\pi^-\nu_\tau \gamma$ decay channels are not
suppressed by $G$-parity considerations and may represent a serious background
in searches of SCC in the former. We compute the observables associated to
these radiative decays using Resonance Chiral Lagrangians and conclude that
vetoing photons with $E_\gamma>100$ MeV should get rid of this background in
the Belle-II environment searching for the $\tau^-\to\eta \pi^-\nu_\tau $
channel. Similar considerations hold inconclusive for decays involving the
$\eta^\prime$ given the theory uncertainties in the prediction of the
$\tau^-\to\eta^\prime\pi^-\nu_\tau$ branching ratio. Still, additional
kinematics-based cuts should be able to suppress this background in the
$\eta^\prime$ case to a negligible level.


title:
A Note on Some Recent Results for the Bernoulli Numbers of the Second
  Kind

abstract:
  In a recent issue of the Bulletin of the Korean Mathematical Society, Qi and
Zhang discovered an interesting integral representation for the Bernoulli
numbers of the second kind (also known as Gregory's coefficients, Cauchy
numbers of the first kind, and the reciprocal logarithmic numbers). The same
representation also appears in many other sources, either with no references to
its author, or with references to various modern researchers. In this short
note, we show that this representation is a rediscovery of an old result
obtained in the XIXth century by Ernst Schr\"oder. We also demonstrate that the
same integral representation may be readily derived by means of complex
integration. Moreover, we discovered that the asymptotics of these numbers were
also the subject of several rediscoveries, including very recent ones. In
particular, the first-order asymptotics, which are usually (and erroneously)
credited to Johan F. Steffensen, actually date back to the mid-XIXth century,
and probably were known even earlier.


title: The isoperimetric number of the incidence graph of PG(n,q)

abstract:
  Let $\Gamma_{n,q}$ be the point-hyperplane incidence graph of the projective
space $\operatorname{PG}(n,q)$, where $n \ge 2$ is an integer and $q$ a prime
power. We determine the order of magnitude of $1-i_V(\Gamma_{n,q})$, where
$i_V(\Gamma_{n,q})$ is the vertex-isoperimetric number of $\Gamma_{n,q}$. We
also obtain the exact values of $i_V(\Gamma_{2,q})$ and the related
incidence-free number of $\Gamma_{2,q}$ for $q \le 16$.


title: Simulation Study of Hemispheric Phase-Asymmetry in the Solar Cycle

abstract:
  Observations of the sun suggest that solar activities systematically create
north-south hemispheric asymmetries. For instance, the hemisphere in which the
sunspot activity is more active tends to switch after the early half of each
solar cycle. Svalgaard & Kamide (2013) recently pointed out that the time gaps
of polar field reversal between the north and south hemispheres are simply
consequences of the asymmetry of sunspot activity. However, the mechanism
underlying the asymmetric feature in solar cycle activities is not yet well
understood. In this paper, in order to explain the cause of the asymmetry from
the theoretical point of view, we investigate the relationship between the
dipole- and quadrupole-type components of the magnetic field in the solar cycle
using the mean-field theory based on the flux transport dynamo model. As a
result, we found that there are two different attractors of the solar cycle, in
which either the north or the south polar field is first reversed, and that the
flux transport dynamo model well explains the phase-asymmetry of sunspot
activity and the polar field reversal without any ad hoc source of asymmetry.


title:
Local Uniqueness and Refined Spike Profiles of Ground States for
  Two-Dimensional Attractive Bose-Einstein Condensates

abstract:
  We consider ground states of two-dimensional Bose-Einstein condensates in a
trap with attractive interactions, which can be described equivalently by
positive minimizers of the $L^2-$critical constraint Gross-Pitaevskii energy
functional. It is known that ground states exist if and only if $a< a^*:=
\|w\|_2^2$, where $a$ denotes the interaction strength and $w$ is the unique
positive solution of $\Delta w-w+w^3=0$ in $R^2$. In this paper, we prove the
local uniqueness and refined spike profiles of ground states as $a\nearrow
a^*$, provided that the trapping potential $h(x)$ is homogeneous and
$H(y)=\int_{R^2} h(x+y)w^2(x)dx$ admits a unique and non-degenerate critical
point.


title:
Long-range dispersion effects on the water/vapor interface simulated
  using the most common models

abstract:
  The long-range contribution to dispersion forces is known to have a major
impact on the properties of inhomogeneous fluids, and its correct treatment is
increasingly recognized as being a necessary requirement to avoid
cutoff-related artefacts. Although analytical corrections for quantities like
the surface tension are known, these can not take into account the structural
changes induced by the long-range contributions. Here, we analyze the
interfacial properties of seven popular water models, comparing the results
with the cut-off version of the dispersion potential. The differences in
surface tension estimates are in all cases found to be less than 2 mN/m.


title:
On warped product manifolds satisfying some pseudosymmetric type
  conditions

abstract:
  The object of the present paper is to study the characterization of warped
product manifolds satisfying some pseudosymmetric type conditions, especially,
due to projective curvature tensor. For this purpose we consider a warped
product manifold satisfying the pseudosymmetric type condition $R\cdot R = L_1
Q(g,R) + L_2 Q(S,R)$ and evaluate its characterization theorem. As special
cases of $L_1$ and $L_2$ we find out the necessary and sufficient condition for
a warped product manifold to satisfy various pseudosymmetric type, such as
pseudosymmetry, Ricci generalized pseudosymmetry, semisymmetry due to
projective curvature tensor ($P\cdot R = 0$), pseudosymmetry due to projective
curvature tensor ($P\cdot R = L Q(g,R)$) etc. Finally we present some suitable
examples of warped product manifolds satisfying such pseudosymmetric type
conditions.


title:
Polychromatic colorings of complete graphs with respect to 1-,2-factors
  and Hamiltonian cycles

abstract:
  If G is a graph and H is a set of subgraphs of G, then an edge-coloring of G
is called H-polychromatic if every graph from H gets all colors present in G on
its edges. The H-polychromatic number of G, denoted poly_H(G), is the largest
number of colors in an H-polychromatic coloring. In this paper, poly_H(G) is
determined exactly when G is a complete graph and H is the family of all
1-factors. In addition poly_H(G) is found up to an additive constant term when
G is a complete graph and H is the family of all 2-factors, or the family of
all Hamiltonian cycles.


title: Ideal Magnetohydrodynamics with Radiative Terms: Energy Conditions

abstract:
  Nowadays, the magnetic and radiation fields are very important to understand
the matter accretion into compact objects, the dynamics of binary systems, the
equilibrium configurations of neutron stars, the photon diffusion, etc. The
energy and the momentum associated to these fields, along with the matter one,
need to satisfy some conditions that guarantee an appropriate physical behavior
of the source and its gravitational field. Based on this fact, we present the
energy conditions for a perfect fluid with magnetic and radiation field, in
which the radiation part of the energy-momentum tensor is assumed to be
approximately isotropic, in accordance with the optically thick regime. In
order to find these conditions, the stress tensor of the system is written in
an orthonormal basis in which it becomes diagonal, and the energy conditions
are computed through contractions of the energy-momentum tensor with the four
velocity vector of an arbitrary observer. Finally, the conditions for a
magnetized fluid are presented as a particular case in which the radiation
contribution is zero.


title: A randomized FEAST algorithm for generalized eigenvalue problems

abstract:
  The FEAST algorithm, due to Polizzi, is a typical contour-integral based
eigensolver for computing the eigenvalues, along with their eigenvectors,
inside a given region in the complex plane. It was formulated under the
circumstance that the considered eigenproblem is Hermitian. The FEAST algorithm
is stable and accurate, and has attracted much attention in recent years.
However, it was observed that the FEAST algorithm may fail to find the target
eigenpairs when applying it to the non-Hermitian problems. Efforts have been
made to adapt the FEAST algorithm to non-Hermitian cases. In this work, we
develop a new non-Hermitian scheme for the FEAST algorithm. The mathematical
framework will be established, and the convergence analysis of our new method
will be studied. Numerical experiments are reported to demonstrate the
effectiveness of our method and to validate the convergence properties.


title: Gradient Coding

abstract:
  We propose a novel coding theoretic framework for mitigating stragglers in
distributed learning. We show how carefully replicating data blocks and coding
across gradients can provide tolerance to failures and stragglers for
Synchronous Gradient Descent. We implement our schemes in python (using MPI) to
run on Amazon EC2, and show how we compare against baseline approaches in
running time and generalization error.

categories: stat.ML cs.DC cs.IT cs.LG math.IT stat.CO


title:
An Extension of Generalized Linear Models to Finite Mixture Outcome
  Distributions

abstract:
  Finite mixture distributions arise in sampling a heterogeneous population.
Data drawn from such a population will exhibit extra variability relative to
any single subpopulation. Statistical models based on finite mixtures can
assist in the analysis of categorical and count outcomes when standard
generalized linear models (GLMs) cannot adequately account for variability
observed in the data. We propose an extension of GLM where the response is
assumed to follow a finite mixture distribution, while the regression of
interest is linked to the mixture's mean. This approach may be preferred over a
finite mixture of regressions when the population mean is the quantity of
interest; here, only a single regression function must be specified and
interpreted in the analysis. A technical challenge is that the mean of a finite
mixture is a composite parameter which does not appear explicitly in the
density. The proposed model is completely likelihood-based and maintains the
link to the regression through a certain random effects structure. We consider
typical GLM cases where means are either real-valued, constrained to be
positive, or constrained to be on the unit interval. The resulting model is
applied to two example datasets through a Bayesian analysis: one with
success/failure outcomes and one with count outcomes. Supporting the extra
variation is seen to improve residual plots and to appropriately widen
prediction intervals.


title:
Persistence of translational symmetry in the BCS model with radial pair
  interaction

abstract:
  We consider the two-dimensional BCS functional with a radial pair
interaction. We show that the translational symmetry is not broken in a certain
temperature interval below the critical temperature. In the case of vanishing
angular momentum our results carry over to the three-dimensional case.


title: On the generalized porous medium equation in Fourier-Besov spaces

abstract:
  We study a kind of generalized porous medium equation with fractional
Laplacian and abstract pressure term. For a large class of equations
corresponding to the form: $u_t+\nu \Lambda^{\beta}u=\nabla\cdot(u\nabla Pu)$,
we get their local well-posedness in Fourier-Besov spaces for large initial
data. If the initial data is small, then the solution becomes global.
Furthermore, we prove a blowup criterion for the solutions.


title:
Radiation Pattern of Radio and Optical Components of Extended Radio
  Sources

abstract:
  The relation between parameters the D/sqrt(I) and Ic/Isum and radiation
patterns of the optical and radio components of an extended radio source is
analyzed, where D and I are the apparent size and observed radiation intensity
of the source or its components respectively. The parameters of the pattern in
the optical and radio (1.4 GHz) ranges are estimated. The radiation pattern of
extended radio-emitting regions is close to spherical and the radiation of the
central component is concentrated in a 24 degrees wide beam. Its luminosity is
a factor of 4.58 higher than that of the extended component of the radio
source. The radiation pattern of the optical component of the radio source
turned out to be unexpectedly non-spherical: the main lobe of the pattern is
about 26 degrees wide. The g-band luminosity is 6.4-12.3 times higher than the
luminosity of the spherical fraction of the "optical" radiation pattern. A list
of 116 new giant radio sources is presented.


title: Arduino control of a pulsatile flow rig

abstract:
  This note describes the design and testing of a programmable pulsatile flow
pump using an Arduino micro-controller. The goal of this work is to build a
compact and affordable system that can relatively easily be programmed to
generate physiological waveforms. The system described here was designed to be
used in an in-vitro set-up for vascular access hemodynamics research, and hence
incorporates a gear pump that can deliver up to 1.5 l/min in a test flow loop.
After a number of simple identification experiments to assess the dynamic
behaviour of the system, a feed-forward control routine was implemented. The
resulting system was shown to be able to produce the targeted patient-specific
waveform with less than 3.6% error. Finally, we outline how to further increase
the accuracy of the system, and how to adapt it to specific user needs.


title:
Particle velocity based hydrofracturing algorithm for a penny-shaped
  crack

abstract:
  A universal particle velocity based algorithm for simulating hydraulic
fracture with leak-off, previously demonstrated for the PKN and KGD models, is
extended to obtain solutions for a penny-shaped crack. The numerical scheme is
capable of dealing with both the viscosity and toughness dominated regimes,
with the fracture being driven by a power-law fluid. The computational approach
utilizes two dependent variables; the fracture aperture and the reduced
particle velocity. The latter allows for the application of a local condition
of the Stefan type (the speed equation) to trace the fracture front. The
obtained numerical solutions are carefully tested using various methods, and
are shown to achieve a high level of accuracy. Simple, accurate,
semi-analytical approximations of the solution are provided for the zero
leak-off case. A comparison with other results available in the literature is
undertaken.


title: GraCT: A Grammar based Compressed representation of Trajectories

abstract:
  We present a compressed data structure to store free trajectories of moving
objects (ships over the sea, for example) allowing spatio-temporal queries. Our
method, GraCT, uses a $k^2$-tree to store the absolute positions of all objects
at regular time intervals (snapshots), whereas the positions between snapshots
are represented as logs of relative movements compressed with Re-Pair. Our
experimental evaluation shows important savings in space and time with respect
to a fair baseline.


title: Negative definite functions for C*-dynamical systems

abstract:
  Given an action $\alpha$ of a discrete group $G$ on a unital C*-algebra $A$,
we introduce a natural concept of $\alpha$-negative definiteness for functions
from $G$ to $A$, and examine some of the first consequences of such a notion.
In particular, we prove analogs of theorems due to Delorme-Guichardet and
Schoenberg in the classical case where $A$ is trivial. We also give a
characterization of the Haagerup property for the action $\alpha$ when $G$ is
countable.


title: MITHRA 1.0: A full-wave simulation tool for Free Electron Lasers

abstract:
  Free Electron Lasers (FELs) are a solution for providing intense, coherent
and bright radiation in the hard X-ray regime. Due to the low wall-plug
efficiency of FEL facilities, it is crucial and additionally very useful to
develop complete and accurate simulation tools for better optimizing a FEL
interaction. The highly sophisticated dynamics involved in a FEL process was
the main obstacle hindering the development of general simulation tools for
this problem. We present a numerical algorithm based on finite difference time
domain/Particle in cell (FDTD/PIC) in a Lorentz boosted coordinate system which
is able to fulfil a full-wave simulation of a FEL process. The developed
software offers a suitable tool for the analysis of FEL interactions without
considering any of the usual approximations. A coordinate transformation to
bunch rest frame makes the very different length scales of bunch size, optical
wavelengths and the undulator period transform to values with the same order.
Consequently, FDTD/PIC simulations in conjunction with efficient
parallelization techniques make the full-wave simulation feasible using the
available computational resources. Several examples of free electron lasers are
analyzed using the developed software, the results are benchmarked based on
standard FEL codes and discussed in detail.


title: Cyclic Cohomology Groups of Some Self-similar Sets

abstract:
  We define a variant of the Young integration on some kinds of self-similar
sets which are called cellular self-similar sets. This variant is an analogue
of the Young integration defined on the unit interval. We give the criteria of
the variant on cellular self-similar sets, and also show that the variant is a
cyclic 1-cocycle of the algebra of complex-valued H\"older continuous functions
on the cellular self-similar sets. This suggests that the cocycle is a variant
of currents.


title:
Monet: A User-oriented Behavior-based Malware Variants Detection System
  for Android

abstract:
  Android, the most popular mobile OS, has around 78% of the mobile market
share. Due to its popularity, it attracts many malware attacks. In fact, people
have discovered around one million new malware samples per quarter, and it was
reported that over 98% of these new malware samples are in fact "derivatives"
(or variants) from existing malware families. In this paper, we first show that
runtime behaviors of malware's core functionalities are in fact similar within
a malware family. Hence, we propose a framework to combine "runtime behavior"
with "static structures" to detect malware variants. We present the design and
implementation of MONET, which has a client and a backend server module. The
client module is a lightweight, in-device app for behavior monitoring and
signature generation, and we realize this using two novel interception
techniques. The backend server is responsible for large scale malware
detection. We collect 3723 malware samples and top 500 benign apps to carry out
extensive experiments of detecting malware variants and defending against
malware transformation. Our experiments show that MONET can achieve around 99%
accuracy in detecting malware variants. Furthermore, it can defend against 10
different obfuscation and transformation techniques, while only incurs around
7% performance overhead and about 3% battery overhead. More importantly, MONET
will automatically alert users with intrusion details so to prevent further
malicious behaviors.


title: Microphase Separation in Random Multiblock Copolymers

abstract:
  Microphase separation in random multiblock copolymers is studied with
mean-field theory assuming that long blocks of a copolymer are strongly
segregated, whereas short blocks are able to penetrate into "alien" domains and
exchange between the domains and interfacial layer. A bidisperse copolymer with
blocks of only two sizes (long and short) is considered as a model of
multiblock copolymers with high polydispersity in the block size. Short blocks
of the copolymer play an important role in microphase separation. First, their
penetration into the "alien" domains leads to the formation of joint long
blocks in their own domains. Second, short blocks localized at the interface
considerably change the interfacial tension. The possibility of penetration of
short blocks into the "alien" domains is controlled by the product chi*Nsh (chi
is the Flory-Huggins interaction parameter, Nsh is the short block length). At
not very large chi*Nsh, the domain size is larger than that for a regular
copolymer consisting of the same long blocks as in the considered random
copolymer. At a fixed mean block size, the domain size grows with an increase
in the block size dispersity, the rate of the growth being dependent of the
more detailed parameters of the block size distribution.


title:
Differential flatness for neuroscience population dynamics -- A
  preliminary study

abstract:
  The present document is devoted to structural properties of neural population
dynamics and especially their differential flatness. Several applications of
differential flatness in the present context can be envisioned, among which:
trajectory tracking, feedforward to feedback switching, cyclic character,
positivity and boundedness.


title: SUSY $N$-supergroups and their real forms

abstract:
  We study SUSY $N$-supergroups, $N=1,2$, their classification and explicit
realization, together with their real forms. In the end, we give the supergroup
of SUSY preserving automorphism of $\mathbf{C}^{1|1}$ and we identify it with a
subsupergroup of the SUSY preserving automorphisms of $\mathbf{P}^{1|1}$.


title: Label Visualization and Exploration in IR

abstract:
  There is a renaissance in visual analytics systems for data analysis and
sharing, in particular, in the current wave of big data applications. We
introduce RAVE, a prototype that automates the generation of an interface that
uses facets and visualization techniques for exploring and analyzing relevance
assessments data sets collected via crowdsourcing. We present a technical
description of the main components and demonstrate its use.


title:
Deformation in amorphous-crystalline nanolaminates -- an
  effective-temperature theory and interaction between defects

abstract:
  Experiments and atomic-scale simulations suggest that the transmission of
plasticity carriers in deforming amorphous-crystalline nanolaminates is
mediated by the biphase interface between the amorphous and crystalline layers.
In this paper, we present a micromechanics model for these biphase
nanolaminates that describes defect interactions through the
amorphous-crystalline interface (ACI). The model is based on an
effective-temperature framework to achieve a unified description of the slow,
configurational atomic rearrangements in both phases when driven out of
equilibrium. We show how the second law of thermodynamics constrains the
density of defects and the rate of configurational rearrangements, and apply
this framework to dislocations in crystalline solids and shear transformation
zones (STZs) in amorphous materials. The effective-temperature formulation
enables us to interpret the observed movement of dislocations to the ACI and
the production of STZs at the interface as a "diffusion" of configurational
disorder across the material. We demonstrate favorable agreement with
experimental findings reported in (Kim et al., Adv. Funct. Mater., 2011), and
demonstrate how the ACI acts as a sink of dislocations and a source of STZs.


title: Limits in Categories of Vietoris Coalgebras

abstract:
  Motivated by the need to reason about hybrid systems, we study limits in
categories of coalgebras whose underlying functor is a Vietoris polynomial one
- intuitively, the topological analogue of a Kripke polynomial functor. Among
other results, we prove that every Vietoris polynomial functor admits a final
coalgebra if it respects certain conditions concerning separation axioms and
compactness. When the functor is restricted to some of the categories induced
by these conditions the resulting categories of coalgebras are even complete.
As a practical application, we use these developments in the specification and
analysis of non-deterministic hybrid systems, in particular to obtain suitable
notions of stability, and behaviour.


title: Anytime Monte Carlo

abstract:
  Monte Carlo algorithms simulate some prescribed number of samples, taking
some random real time to complete the computations necessary. This work
considers the converse: to impose a real-time budget on the computation, which
results in the number of samples simulated being random. To complicate matters,
the real time taken for each simulation may depend on the sample produced, so
that the samples themselves are not independent of their number, and a length
bias with respect to compute time is apparent. This is especially problematic
when a Markov chain Monte Carlo (MCMC) algorithm is used and the final state of
the Markov chain -- rather than an average over all states -- is required,
which is the case in parallel tempering implementations of MCMC. The length
bias does not diminish with the compute budget in this case. It also occurs in
sequential Monte Carlo (SMC) algorithms, which is the focus of this paper. We
propose an anytime framework to address the concern, using a continuous-time
Markov jump process to study the progress of the computation in real time. We
first show that for any MCMC algorithm, the length bias of the final state's
distribution due to the imposed real-time computing budget can be eliminated by
using a multiple chain construction. The utility of this construction is then
demonstrated on a large-scale SMC^2 implementation, using four billion
particles distributed across a cluster of 128 graphics processing units on the
Amazon EC2 service. The anytime framework imposes a real-time budget on the
MCMC move steps within the SMC$^{2}$ algorithm, ensuring that all processors
are simultaneously ready for the resampling step, demonstrably reducing
idleness to due waiting times and providing substantial control over the total
compute budget.


title:
NuSTAR and XMM-Newton observations of the Arches cluster in 2015: fading
  hard X-ray emission from the molecular cloud

abstract:
  We present results of long NuSTAR (200 ks) and XMM-Newton (100 ks)
observations of the Arches stellar cluster, a source of bright thermal (kT~2
keV) X-rays with prominent Fe XXV K_alpha 6.7 keV line emission and a nearby
molecular cloud, characterized by an extended non-thermal hard X-ray continuum
and fluorescent Fe K_alpha 6.4 keV line of a neutral or low ionization state
material around the cluster. Our analysis demonstrates that the non-thermal
emission of the Arches cloud underwent a dramatic change, with its homogeneous
morphology, traced by fluorescent Fe K_alpha line emission, vanishing after
2012, revealing three bright clumps. The declining trend of the cloud emission,
if linearly fitted, is consistent with half-life decay time of ~8 years. Such
strong variations have been observed in several other molecular clouds in the
Galactic Centre, including the giant molecular cloud Sgr B2, and point toward a
similar propagation of illuminating fronts, presumably induced by the past
flaring activity of Sgr A*.


title: Rings beyond the giant planets

abstract:
  Until 2013, only the giant planets were known to host ring systems. In June
2013, a stellar occulation revealed the presence of narrow and dense rings
around Chariklo, a small Centaur object that orbits between Saturn and Uranus.
Meanwhile, the Cassini spacecraft revealed evidence for the possible past
presence of rings around the Saturnian satellites Rhea and Iapetus. Mars and
Pluto are expected to have tenuous dusty rings, though they have so far evaded
detection. More remotely, transit events observed around a star in 2007 may
have revealed for the first time exoplanetary rings around a giant planet
orbiting that star. So, evidence is building to show that rings are more common
features in the universe than previously thought. Several interesting issues
arising from the discovery (or suspicion) of new ring systems are described in
this chapter.


title: A new approach to ultrasensitive gravitational wave detection

abstract:
  We suggest here a method to detect gravitational waves (GW) different from
the interferometric approach. It is based on two critical steps: conversion of
the GW action into rotational motion and subsequent conversion into electric
current. The ability to detect extremely tiny currents empowers this suggested
approach in which the gravitational wave moves charges around closed loops.
This new method may allow detection of gravitational waves with strain
sensitivities beyond the reach of the interferometric approaches.


title: Sur l'annulation de la valeur centrale de la fonction L de Hecke

abstract:
  In this note, following results from Henri Cohen and Winfried Kohnen, we show
that for all integer k greater than 12 and divisible by 4, there exists a
cuspidal eigenform of weight k for the full modular group SL2(Z) such that its
Hecke L-function does not vanish on k/2.


title:
Fisher information of two superconducting charge qubits under dephasing
  noisy

abstract:
  The dynamics of a charged two-qubit system prepared initially in a maximum
entangled state is discussed, where each qubit interacts independently with a
dephasing channel. The Fisher information is used to estimate the channel and
the energy parameters. Moreover, the contribution from different parts of
Fisher information is discussed. We show that, the degree of estimation of any
parameter depends on the initial value of this parameter. It turns out that the
upper bounds of Fisher information with respect to the dephasing parameter
increase and that corresponding to coupling parameter decreases as the initial
energy of each qubit increases.


title:
Ribbon-move-unknotting-number-two 2-knots,
  pass-move-unknotting-number-two 1-knots, and high dimensional analogue

abstract:
  The (ordinary) unknotting-number of 1-dimensional knots, which is defined by
using the crossing-change, is a very basic and important invariant. It is very
natural to consider the `unknotting-number' associated with other local-moves
on n-dimensional knots, where n is a natural number. In this paper we prove the
following facts.
  For the ribbon-move on 2-knots, which is a kind of local-move on knots, we
have the following: There is a ribbon-move-unknotting-number-two 2-knot. The
ribbon-move-unknotting-number of 2-knots is unbounded.
  For the pass-move on 1-knots, which is a kind of local-move on knots, we have
the following: There is a pass-move-unknotting-number-two 1-knot whose
(ordinary) unknotting-number is 4. For any natural number n, there is a 1-knot
whose pass-move-unknotting-number is>n and whose (ordinary) unknotting-number
is 4n.
  For the high-dimensional-pass-move on high-dimensional knots, which is a kind
of local-move on knots, we have the following: There is a (2k+1,
2k+2)-pass-move-unknotting-number-two (4k+2)-knot. The (2k+1,
2k+2)-pass-move-unknotting-number of (4k+2)-knot is unbounded. There is a
(2k+1, 2k+1)-pass-move-unknotting-number-two (4k+1)-knot. The (2k+1,
2k+1)-pass-move-unknotting-number of (4k+1)-knot is unbounded. There is a
(4k+1)-knot whose twist-move-unknotting-number is n for any natural number n.


title: Richard Dedekind: Style and Influence

abstract:
  This text is based on an invited talk at the Dedekind Symposium at
Braunschweig in October 2016. It summarizes views from my recent commented
edition of Dedekinds two books on the foundations of mathematics.


title: Yosida Duality

abstract:
  In this note we prove Yosida duality --- that is: the category of compact
Hausdorff spaces with continuous maps is dually equivalent to the category of
uniformly complete Archimedean Riesz spaces with distinguished units and
unit-preserving Riesz homomorphisms between them.


title:
Knowledge Elicitation via Sequential Probabilistic Inference for
  High-Dimensional Prediction

abstract:
  Prediction in a small-sized sample with a large number of covariates, the
"small n, large p" problem, is challenging. This setting is encountered in
multiple applications, such as precision medicine, where obtaining additional
samples can be extremely costly or even impossible, and extensive research
effort has recently been dedicated to finding principled solutions for accurate
prediction. However, a valuable source of additional information, domain
experts, has not yet been efficiently exploited. We formulate knowledge
elicitation generally as a probabilistic inference process, where expert
knowledge is sequentially queried to improve predictions. In the specific case
of sparse linear regression, where we assume the expert has knowledge about the
values of the regression coefficients or about the relevance of the features,
we propose an algorithm and computational approximation for fast and efficient
interaction, which sequentially identifies the most informative features on
which to query expert knowledge. Evaluations of our method in experiments with
simulated and real users show improved prediction accuracy already with a small
effort from the expert.


title: Uniqueness of the $1$D Compressible to Incompressible Limit

abstract:
  Consider two compressible immiscible fluids in 1D in the isentropic
approximation. The first fluid is surrounded and in contact with the second
one. As the Mach number of the first fluid vanishes, the coupled dynamics of
the two fluids results as the compressible to incompressible limit and is known
to satisfy an ODE--PDE system. Below, a characterization of this limit is
provided, ensuring its uniqueness.


title:
Devil's Staircase Continuum in the Chiral Clock Spin Glass with
  Competing Ferromagnetic-Antiferromagnetic and Left-Right Chiral Interactions

abstract:
  The chiral clock spin-glass model with q=5 states, with both competing
ferromagnetic-antiferromagnetic and left-right chiral frustrations, is studied
in d=3 spatial dimensions by renormalization-group theory. The global phase
diagram is calculated in temperature, antiferromagnetic bond concentration p,
random chirality strength, and right-chirality concentration c. The system has
a ferromagnetic phase, a multitude of different chiral phases, a chiral
spin-glass phase, and a critical (algebraically) ordered phase. The
ferromagnetic and chiral phases accumulate at the disordered phase boundary and
form a spectrum of devil's staircases, where different ordered phases
characteristically intercede at all scales of phase-diagram space. Shallow and
deep reentrances of the disordered phase, bordered by fragments of regular and
temperature-inverted devil's staircases, are seen. The extremely rich phase
diagrams are presented as continuously and qualitatively changing videos.


title: Hadronic light-by-light contribution to the muon g-2

abstract:
  We have computed the hadronic light-by-light (LbL) contribution to the muon
anomalous magnetic moment $a_\mu$ in the frame of Chiral Perturbation Theory
with the inclusion of the lightest resonance multiplets as dynamical fields
(R$\chi$T). It is essential to give a more accurate prediction of this hadronic
contribution due to the future projects of J-Parc and FNAL on reducing the
uncertainty in this observable. We, therefore, computed the pseudoscalar
transition form factor and proposed the measurement of the
$e^+e^-\to\mu^+\mu^-\pi^0$ cross section and dimuon invariant mass spectrum to
determine more accurately its parameters. Then, we evaluated the pion exchange
contribution to $a_\mu$, obtaining $(6.66\pm0.21)\cdot10^{-10}$. By comparing
the pion exchange contribution and the pion-pole approximation to the
corresponding transition form factor ($\pi$TFF) we recalled that the latter
underestimates the complete $\pi$TFF by (15-20)\%. Then, we obtained the
$\eta^({}'^)$ TFF, obtaining a total contribution of the lightest pseudoscalar
exchanges of $(10.47\pm0.54)\cdot10^{-10}$, in agreement with previous results
and with smaller error.


title:
A counterexample to a strong variant of the Polynomial Freiman-Ruzsa
  conjecture in Euclidean space

abstract:
  The Polynomial Freiman-Ruzsa conjecture is one of the central open problems
in additive combinatorics. If true, it would give tight quantitative bounds
relating combinatorial and algebraic notions of approximate subgroups. In this
note, we restrict our attention to subsets of Euclidean space. In this regime,
the original conjecture considers approximate algebraic subgroups as the set of
lattice points in a convex body. Green asked in 2007 whether this can be
simplified to a generalized arithmetic progression, while not losing more than
a polynomial factor in the underlying parameters. We give a negative answer to
this question, based on a recent reverse Minkowski theorem combined with
estimates for random lattices.


title:
An Extended Cubic B-spline Finite Element Method for Solving Generalized
  Burgers-sher Equation

abstract:
  In this study collocation method based on the extended B-spline functions for
the numerical solutions of the Generalized Burhers Fisher equation is set up.
The approximate solution of the equation is constructed with the combination of
the extended B-splines. Some initial boundary value problems are solved by the
proposed method. The accuracy and validity and of the method is demonstrated by
measuring the error between the numerical solutions and the analytical
solutions, if exist.


title: Comment on "Motional Averaging of Nuclear Resonance in a Field Gradient"

abstract:
  In the Letter by Nanette N. Jarenwattananon and Louis-S. Bouchard [PRL 114,
197601 (2015)] an NMR experiment on gases in the presence of a magnetic-field
gradient has been considered. As distinct from the traditional description of
molecular self-diffusion, the authors calculate the decoherence of the signal
taking into account the histories of molecular displacements. For this purpose
the generalized Langevin equation (GLE) is applied. We show that the use of
this equation is inappropriate. The calculations performed in the Letter are
not correct and do not lead to the reported revised expression for line
broadening that takes into account the autocorrelation effects in the diffusion
process. The surprising temperature behavior of the observed NMR signal is thus
not explained. In particular, the linewidth does not follow the power law f ~
T^(-1/2) at high temperatures.
  We give also Remarks on the Jarenwattananon and Bouchard Reply [Phys. Rev.
Lett. 117, 249702 (2016)].


title: On the Capacity and Depth of Compact Surfaces

abstract:
  K. Borsuk in 1979, in the Topological Conference in Moscow, introduced the
concept of capacity and depth of a compactum. In this paper, we compute the
capacity and depth of compact surfaces. We show that the capacity and depth of
every compact orientable surface of genus $g\geq 0$ is equal to $g+2$. Also, we
prove that the capacity and depth of a compact non-orientable surface of genus
$g>0$ is $[\frac{g}{2}]+2$.


title:
Train Timetabling on double track and multiple station capacity railway
  with useful upper and lower bounds

abstract:
  Train scheduling is one of the significant issues in the railway industry in
recent years since it has an important role in efficacy of railway
infrastructure. In this paper, the timetabling problem of a multiple tracked
railway network is discussed. More specifically, a general model is presented
here in which a set of operational and safety requirements is considered. The
model handles the trains overtaking in stations and considers the stations
capacity. The objective function is to minimize the total travel time.
Unfortunately, the problem is NP-hard and real size problems cannot be solved
in an acceptable amount of time. In order to reduce the processing time, we
presented some heuristic rules, which reduce the number of binary variables.
These rules are based on problem's parameters such as travel time, dwell time
and safety time of stations and try to remove the impracticable areas of the
solution space. Furthermore, a Lagrangian Relaxation algorithm model is
presented in order to find a lower-bound. Finally, comprehensive numerical
experiments on the Tehran Metro case are reported. Results show the efficiency
of the heuristic rules and also the Lagrangian Relaxation method in a way that
for all analyzed problems the optimum value are obtained.


title:
Effect of meson cloud on the jet nuclear modification factor in $pA$
  collisions

abstract:
  We study the effect of the nucleon meson cloud on centrality dependence of
the jet nuclear modification factor $R_{pA}$. We find that the meson-baryon
Fock components may lead to a noticeable deviation of $R_{pA}$ from unity. Our
results for $R_{pA}$ show the same tendency as that observed by ATLAS in $p+Pb$
collisions at $\sqrt{s}=5.02$ TeV. The meson cloud suppresses the central jet
events and enhances the peripheral jet events. But quantitatively the effect is
somewhat smaller than in the data.


title:
Kondo Destruction in RKKY-Coupled Kondo Lattice and Multi-Impurity
  Systems

abstract:
  In a Kondo lattice, the spin exchange coupling between a local spin and the
conduction electrons acquires nonlocal contributions due to conduction electron
scattering from surrounding local spins and the subsequent RKKY interaction. It
leads to a hitherto unrecognized interference of Kondo screening and the RKKY
interaction beyond the Doniach scenario. We develop a renormalization group
theory for the RKKY-modified Kondo vertex. The Kondo temperature, $T_K(y)$, is
suppressed in a universal way, controlled by the antiferromagnetic RKKY
coupling parameter $y$. Complete spin screening ceases to exist beyond a
critical RKKY strength $y_c$ even in the absence of magnetic ordering. At this
breakdown point, $T_K(y)$ remains nonzero and is not defined for larger RKKY
couplings, $y>y_c$. The results are in quantitative agreement with STM
spectroscopy experiments on tunable two-impurity Kondo systems. The possible
implications for quantum critical scenarios in heavy-fermion systems are
discussed.


title:
A Primal-Dual Approximation Algorithm for Min-Sum Single-Machine
  Scheduling Problems

abstract:
  We consider the following single-machine scheduling problem, which is often
denoted $1||\sum f_{j}$: we are given $n$ jobs to be scheduled on a single
machine, where each job $j$ has an integral processing time $p_j$, and there is
a nondecreasing, nonnegative cost function $f_j(C_{j})$ that specifies the cost
of finishing $j$ at time $C_{j}$; the objective is to minimize $\sum_{j=1}^n
f_j(C_j)$. Bansal \& Pruhs recently gave the first constant approximation
algorithm with a performance guarantee of 16. We improve on this result by
giving a primal-dual pseudo-polynomial-time algorithm based on the recently
introduced knapsack-cover inequalities. The algorithm finds a schedule of cost
at most four times the constructed dual solution. Although we show that this
bound is tight for our algorithm, we leave open the question of whether the
integrality gap of the LP is less than 4. Finally, we show how the technique
can be adapted to yield, for any $\epsilon >0$, a $(4+\epsilon )$-approximation
algorithm for this problem.


title: Three pearls of Bernoulli numbers

abstract:
  The Bernoulli numbers are fascinating and ubiquitous numbers, they occur in
several domains of Mathematics like Number theory (FLT), Group theory, Calculus
and even in Physics. Since Bernoulli's work, they are yet studied to understand
their deep nature and particularly to find relationships between them. In this
paper, we give, firstly, a short response to a problem stated, in 1971, by
Carlitz and studied by many authors like Prodinger \cite{PRO}, the second pearl
is an answer to a question raised, in 2008, by Tom Apostol .The third pearl is
another proof of a relationship already given in 2011, by the authors.


title:
Estimating covariance functions of multivariate skew-Gaussian random
  fields on the sphere

abstract:
  This paper considers a multivariate spatial random field, with each component
having univariate marginal distributions of the skew-Gaussian type. We assume
that the field is defined spatially on the unit sphere embedded in
$\mathbb{R}^3$, allowing for modeling data available over large portions of
planet Earth. This model admits explicit expressions for the marginal and cross
covariances. However, the $n$-dimensional distributions of the field are
difficult to evaluate, because it requires the sum of $2^n$ terms involving the
cumulative and probability density functions of a $n$-dimensional Gaussian
distribution. Since in this case inference based on the full likelihood is
computationally unfeasible, we propose a composite likelihood approach based on
pairs of spatial observations. This last being possible thanks to the fact that
we have a closed form expression for the bivariate distribution. We illustrate
the effectiveness of the method through simulation experiments and the analysis
of a real data set of minimum and maximum temperatures.


title:
Hydrodynamic-type systems describing 2-dimensional polynomially
  integrable geodesic flows

abstract:
  Starting from a homogeneous polynomial in momenta of arbitrary order we
extract multi-component hydrodynamic-type systems which describe 2-dimensional
geodesic flows admitting the initial polynomial as integral. All these
hydrodynamic-type systems are semi-Hamiltonian, thus implying that they are
integrable according to the generalized hodograph method. Moreover, they are
integrable in a constructive sense as polynomial first integrals allow to
construct generating equations of conservation laws. According to the
multiplicity of the roots of the polynomial integral, we separate integrable
particular cases.


title: Oblivious Sorting and Queues

abstract:
  We present a deterministic oblivious LIFO (Stack), FIFO, double-ended and
double-ended priority queue as well as an oblivious mergesort and quicksort
algorithm. Our techniques and ideas include concatenating queues end-to-end,
size balancing of multiple arrays, several multi-level partitionings of an
array. Our queues are the first to enable executions of pop and push operations
without any change of the data structure (controlled by a parameter). This
enables interesting applications in computing on encrypted data such as hiding
confidential expressions. Mergesort becomes practical using our LIFO queue, ie.
it improves prior work (STOC '14) by a factor of (more than) 1000 in terms of
comparisons for all practically relevant queue sizes. We are the first to
present double-ended (priority) and LIFO queues as well as oblivious quicksort
which is asymptotically optimal. Aside from theortical analysis, we also
provide an empirical evaluation of all queues.


title:
Existence of martingale solutions and the incompressible limit for
  stochastic compressible flows on the whole space

abstract:
  We give an existence and asymptotic result for the so-called finite energy
weak martingale solution of the compressible isentropic Navier--Stokes system
driven by some random force in the whole spatial region. In particular, given a
general nonlinear multiplicative noise, we establish the convergence to the
incompressible system as the Mach number, representing the ratio between the
average flow velocity and the speed of sound, approaches zero.


title: Obfuscation using Encryption

abstract:
  Protecting source code against reverse engineering and theft is an important
problem. The goal is to carry out computations using confidential algorithms on
an untrusted party while ensuring confidentiality of algorithms. This problem
has been addressed for Boolean circuits known as `circuit privacy'. Circuits
corresponding to real-world programs are impractical. Well-known obfuscation
techniques are highly practicable, but provide only limited security, e.g., no
piracy protection. In this work, we modify source code yielding programs with
adjustable performance and security guarantees ranging from
indistinguishability obfuscators to (non-secure) ordinary obfuscation. The idea
is to artificially generate `misleading' statements. Their results are combined
with the outcome of a confidential statement using encrypted \emph{selector
variables}. Thus, an attacker must `guess' the encrypted selector variables to
disguise the confidential source code. We evaluated our method using more than
ten programmers as well as pattern mining across open source code repositories
to gain insights of (micro-)coding patterns that are relevant for generating
misleading statements. The evaluation reveals that our approach is effective in
that it successfully preserves source code confidentiality.


title:
Location, identification, and representability of monotone operators in
  locally convex spaces

abstract:
  In this paper we study, in the relaxed context of locally convex spaces,
intrinsic properties of monotone operators needed for the sum conjecture for
maximal monotone operators to hold under classical interiority-type domain
constraints.


title: Dual Moments and Risk Attitudes

abstract:
  In decision under risk, the primal moments of mean and variance play a
central role to define the local index of absolute risk aversion. In this
paper, we show that in canonical non-EU models dual moments have to be used
instead of, or on par with, their primal counterparts to obtain an equivalent
index of absolute risk aversion.


title:
The evolution of the radial gradient of Oxygen abundance in spiral
  galaxies

abstract:
  The aim of this work is to present our new series of chemical evolution
models computed for spiral and low mass galaxies of different total masses and
star formation efficiencies. We analyze the results of models, in particular
the evolution of the radial gradient of oxygen abundance. Furthermore, we study
the role of the infall rate and of the star formation history on the variations
of this radial gradient. The relations between the O/H radial gradient and
other spiral galaxies characteristics as the size or the stellar mass are also
shown. We find that the radial gradient is mainly a scale effect which
basically does not change with the redshift (or time) if it is measured within
the optical radius. Moreover, when it is measured as a function of a normalized
radius, show a similar value for all galaxies masses, showing a correlation
with a dispersion around an average value which is due to the differences star
formation efficiencies, in agreement with the idea of an universal O/H radial
gradient


title: An Empirical Study of ADMM for Nonconvex Problems

abstract:
  The alternating direction method of multipliers (ADMM) is a common
optimization tool for solving constrained and non-differentiable problems. We
provide an empirical study of the practical performance of ADMM on several
nonconvex applications, including l0 regularized linear regression, l0
regularized image denoising, phase retrieval, and eigenvector computation. Our
experiments suggest that ADMM performs well on a broad class of non-convex
problems. Moreover, recently proposed adaptive ADMM methods, which
automatically tune penalty parameters as the method runs, can improve algorithm
efficiency and solution quality compared to ADMM with a non-tuned penalty.


title:
Non-negative Factorization of the Occurrence Tensor from Financial
  Contracts

abstract:
  We propose an algorithm for the non-negative factorization of an occurrence
tensor built from heterogeneous networks. We use l0 norm to model sparse errors
over discrete values (occurrences), and use decomposed factors to model the
embedded groups of nodes. An efficient splitting method is developed to
optimize the nonconvex and nonsmooth objective. We study both synthetic
problems and a new dataset built from financial documents, resMBS.


title: Harmonic Maass forms associated to real quadratic fields

abstract:
  In this paper, we explicitly construct harmonic Maass forms that map to the
weight one theta series associated by Hecke to odd ray class group characters
of real quadratic fields. From this construction, we give precise arithmetic
information contained in the Fourier coefficients of the holomorphic part of
the harmonic Maass form, establishing the main part of a conjecture of the
second author.


title:
Fractional constitutive equation (FACE) for non-Newtonian fluid flow:
  Theoretical description

abstract:
  Non-Newtonian fluid flow might be driven by spatially nonlocal velocity, the
dynamics of which can be described by promising fractional derivative models.
This short communication proposes a space FrActional-order Constitutive
Equation (FACE) that links viscous shear stress with the velocity gradient, and
then interprets physical properties of non-Newtonian fluids for steady pipe
flow. Results show that the generalized FACE model contains previous
non-Newtonian fluid flow models as end-members by simply adjusting the order of
the fractional index, and a preliminary test shows that the FACE model
conveniently captures the observed growth of shear stress for various velocity
gradients. Further analysis of the velocity profile, frictional head loss, and
Reynolds number using the FACE model also leads to analytical tools and
criterion that can significantly extend standard models in quantifying the
complex dynamics of non-Newtonian fluid flow with a wide range of spatially
nonlocal velocities.


title: FOCA: A Methodology for Ontology Evaluation

abstract:
  Modeling an ontology is a hard and time-consuming task. Although
methodologies are useful for ontologists to create good ontologies, they do not
help with the task of evaluating the quality of the ontology to be reused. For
these reasons, it is imperative to evaluate the quality of the ontology after
constructing it or before reusing it. Few studies usually present only a set of
criteria and questions, but no guidelines to evaluate the ontology. The effort
to evaluate an ontology is very high as there is a huge dependence on the
evaluator's expertise to understand the criteria and questions in depth.
Moreover, the evaluation is still very subjective. This study presents a novel
methodology for ontology evaluation, taking into account three fundamental
principles: i) it is based on the Goal, Question, Metric approach for empirical
evaluation; ii) the goals of the methodologies are based on the roles of
knowledge representations combined with specific evaluation criteria; iii) each
ontology is evaluated according to the type of ontology. The methodology was
empirically evaluated using different ontologists and ontologies of the same
domain. The main contributions of this study are: i) defining a step-by-step
approach to evaluate the quality of an ontology; ii) proposing an evaluation
based on the roles of knowledge representations; iii) the explicit difference
of the evaluation according to the type of the ontology iii) a questionnaire to
evaluate the ontologies; iv) a statistical model that automatically calculates
the quality of the ontologies.


title: Resonant Raman imaging of MoS2-substrate interaction

abstract:
  We report a study of long-range MoS2-substrate interaction using resonant
Raman imaging. We observed a strong thickness-dependent peak shift of a
Raman-forbidden mode that can be used as a new method of determining the
thickness of multilayered MoS2 flakes. In addition, dependence of the Raman
scattering intensity on thickness is explained by the interference enhancement
theory. Finally, the resonant Raman spectra on different substrates are
analysed.


title: Stability of periodic orbits in no-slip billiards

abstract:
  Rigid bodies collision maps in dimension two, under a natural set of physical
requirements, can be classified into two types: the standard specular
reflection map and a second which we call, after Broomhead and Gutkin, no-slip.
This leads to the study of no-slip billiards--planar billiard systems in which
the moving particle is a disc (with rotationally symmetric mass distribution)
whose translational and rotational velocities can both change at each collision
with the boundary of the billiard domain.
  In this paper we greatly extend previous results on boundedness of orbits
(Broomhead and Gutkin) and linear stability of periodic orbits for a Sinai-type
billiard (Wojtkowski) for no-slip billiards. We show among other facts that:
(i) for billiard domains in the plane having piecewise smooth boundary and at
least one corner of inner angle less than $\pi$, no-slip billiard dynamics will
always contain elliptic period-$2$ orbits; (ii) polygonal no-slip billiards
always admit small invariant open sets and thus cannot be ergodic with respect
to the canonical invariant billiard measure; (iii) the no-slip version of a
Sinai billiard must contain linearly stable periodic orbits of period $2$ and,
more generally, we provide a curvature threshold at which a commonly occurring
period-$2$ orbit shifts from being hyperbolic to being elliptic; (iv) finally,
we make a number of observations concerning periodic orbits in a class of
polygonal billiards.


title:
The Majorana STM as a perfect detector of odd-frequency
  superconductivity

abstract:
  We propose a novel scanning tunneling microscope (STM) device in which the
tunneling tip is formed by a Majorana bound state (MBS). This peculiar bound
state exists at the boundary of a one-dimensional topological superconductor.
Since the MBS has to be effectively spinless and local, we argue that it is the
smallest unit that shows itself odd-frequency superconducting pairing.
Odd-frequency superconductivity is characterized by an anomalous Green function
which is an odd function of the time arguments of the two electrons forming the
Cooper pair. Interestingly, our Majorana STM can be used as the perfect
detector of odd-frequency superconductivity. The reason is that a supercurrent
between the Majorana STM and any other superconductor can only flow if the
latter system exhibits itself odd-frequency pairing. To illustrate our general
idea, we consider the tunneling problem of the Majorana STM coupled to a
quantum dot in vicinity to a conventional superconductor. In such a
(superconducting) quantum dot, the effective pairing can be tuned from even- to
odd-frequency behavior if an external magnetic field is applied to it.


title: Limited Feedback in MISO Systems with Finite-Bit ADCs

abstract:
  We analyze limited feedback in systems where a multiple-antenna transmitter
sends signals to single-antenna receivers with finite-bit ADCs. If channel
state information (CSI) is not available with high resolution at the
transmitter and the precoding is not well designed, the inter-user interference
is a big decoding challenge for receivers with low-resolution quantization. In
this paper, we derive achievable rates with finite-bit ADCs and finite-bit CSI
feedback. The performance loss compared to the case with perfect CSI is then
analyzed. The results show that the number of bits per feedback should increase
linearly with the ADC resolution to restrict the loss.


title:
A large arboreal Galois representation for a cubic postcritically finite
  polynomial

abstract:
  We give a complete description of the arboreal Galois representation of a
certain postcritically finite cubic polynomial over a large class of number
fields and for a large class of basepoints. This is the first such example that
is not conjugate to a power map, Chebyshev polynomial, or Latt\`es map. The
associated Galois action on an infinite ternary rooted tree has Hausdorff
dimension bounded strictly between that of the infinite wreath product of
cyclic groups and that of the infinite wreath product of symmetric groups. We
deduce a zero-density result for prime divisors in an orbit under this
polynomial. We also obtain a zero-density result for the set of places of
convergence of Newton's method for a certain cubic polynomial, thus resolving
the first nontrivial case of a conjecture of Faber and Voloch.


title:
Accurate representation of formation energies of crystalline alloys with
  many components

abstract:
  In this paper I propose a new model for representing the formation energies
of multicomponent crystalline alloys as a function of atom types. In the cases
when displacements of atoms from their equilibrium positions are not large, the
proposed method has a similar accuracy as the state-of-the-art cluster
expansion method, and a better accuracy when the fitting dataset size is small.
The proposed model has only two tunable parameters - one for the interaction
range and one for the interaction complexity.


title: Information Theory of Molecular Communication: Directions and Challenges

abstract:
  Molecular Communication (MC) is a communication strategy that uses molecules
as carriers of information, and is widely used by biological cells. As an
interdisciplinary topic, it has been studied by biologists, communication
theorists and a growing number of information theorists. This paper aims to
specifically bring MC to the attention of information theorists. To do this, we
first highlight the unique mathematical challenges of studying the capacity of
molecular channels. Addressing these problems require use of known, or
development of new mathematical tools. Toward this goal, we review a subjective
selection of the existing literature on information theoretic aspect of
molecular communication. The emphasis here is on the mathematical techniques
used, rather than on the setup or modeling of a specific paper. Finally, as an
example, we propose a concrete information theoretic problem that was motivated
by our study of molecular communication.


title:
An Energy-Efficient VCO-Based Matrix Multiplier Block to Support On-Chip
  Image Analysis

abstract:
  Images typically are represented as uniformly sampled data in the form of
matrix of pixels/voxels. Therefore, matrix multiply-and-accumulate (MAC) forms
the core of most state-of-the-art image analysis algorithms. While digital
implementation of MAC has generally been the preferred approach, high power
consumption is an impediment to adopting it for medical image analysis. In this
work, we present a time-domain signal processing architecture which performs
MAC operations with 7bit accuracy while consuming 400X lower energy than
digital implementation. The proposed architecture performs analog computation
using mostly digital circuits and is suitable for scaled CMOS technologies. The
proposed time-domain MAC architecture is expected to play a central role in
empowering the advancement of various on-chip image analysis operations.


title: Community Detection Algorithm Evaluation using Size and Hashtags

abstract:
  Understanding community structure in social media is critical due to its
broad applications such as friend recommendations, link predictions and
collaborative filtering. However, there is no widely accepted definition of
community in literature. Existing work use structure related metrics such as
modularity and function related metrics such as ground truth to measure the
performance of community detection algorithms, while ignoring an important
metric, size of the community. [1] suggests that the size of community with
strong ties in social media should be limited to 150. As we discovered in this
paper, the majority of the communities obtained by many popular community
detection algorithms are either very small or very large. Too small communities
don't have practical value and too large communities contain weak connections
therefore not stable. In this paper, we compare various community detection
algorithms considering the following metrics: size of the communities, coverage
of the communities, extended modularity, triangle participation ratio, and user
interest in the same community. We also propose a simple clique based algorithm
for community detection as a baseline for the comparison. Experimental results
show that both our proposed algorithm and the well-accepted disjoint algorithm
InfoMap perform well in all the metrics.


title:
Quantum dynamical entropy, chaotic unitaries and complex Hadamard
  matrices

abstract:
  We introduce two information-theoretical invariants for the projective
unitary group acting on a finite-dimensional complex Hilbert space: PVM- and
POVM-dynamical (quantum) entropies. They quantify the randomness of the
successive quantum measurement results in the case where the evolution of the
system between each two consecutive measurements is described by a given
unitary operator. We study the class of chaotic unitaries, i.e., the ones of
maximal entropy or, equivalently, such that they can be represented by suitably
rescaled complex Hadamard matrices in some orthonormal bases. We provide
necessary conditions for a unitary operator to be chaotic, which become also
sufficient for qubits and qutrits. These conditions are expressed in terms of
the relation between the trace and the determinant of the operator. We also
compute the volume of the set of chaotic unitaries in dimensions two and three,
and the average PVM-dynamical entropy over the unitary group in dimension two.
We prove that this mean value behaves as the logarithm of the dimension of the
Hilbert space, which implies that the probability that the dynamical entropy of
a unitary is almost as large as possible approaches unity as the dimension
tends to infinity.


title:
Technical Report: A Generalized Matching Pursuit Approach for
  Graph-Structured Sparsity

abstract:
  Sparsity-constrained optimization is an important and challenging problem
that has wide applicability in data mining, machine learning, and statistics.
In this paper, we focus on sparsity-constrained optimization in cases where the
cost function is a general nonlinear function and, in particular, the sparsity
constraint is defined by a graph-structured sparsity model. Existing methods
explore this problem in the context of sparse estimation in linear models. To
the best of our knowledge, this is the first work to present an efficient
approximation algorithm, namely, Graph-structured Matching Pursuit (Graph-Mp),
to optimize a general nonlinear function subject to graph-structured
constraints. We prove that our algorithm enjoys the strong guarantees analogous
to those designed for linear models in terms of convergence rate and
approximation accuracy. As a case study, we specialize Graph-Mp to optimize a
number of well-known graph scan statistic models for the connected subgraph
detection task, and empirical evidence demonstrates that our general algorithm
performs superior over state-of-the-art methods that are designed specifically
for the task of connected subgraph detection.


title:
Multiple Instance Learning: A Survey of Problem Characteristics and
  Applications

abstract:
  Multiple instance learning (MIL) is a form of weakly supervised learning
where training instances are arranged in sets, called bags, and a label is
provided for the entire bag. This formulation is gaining interest because it
naturally fits various problems and allows to leverage weakly labeled data.
Consequently, it has been used in diverse application fields such as computer
vision and document classification. However, learning from bags raises
important challenges that are unique to MIL. This paper provides a
comprehensive survey of the characteristics which define and differentiate the
types of MIL problems. Until now, these problem characteristics have not been
formally identified and described. As a result, the variations in performance
of MIL algorithms from one data set to another are difficult to explain. In
this paper, MIL problem characteristics are grouped into four broad categories:
the composition of the bags, the types of data distribution, the ambiguity of
instance labels, and the task to be performed. Methods specialized to address
each category are reviewed. Then, the extent to which these characteristics
manifest themselves in key MIL application areas are described. Finally,
experiments are conducted to compare the performance of 16 state-of-the-art MIL
methods on selected problem characteristics. This paper provides insight on how
the problem characteristics affect MIL algorithms, recommendations for future
benchmarking and promising avenues for research.


title:
Palomar Transient Factory and RR Lyrae: Metallicity-Light Curve Relation
  Based on ab-Type RR Lyrae in Kepler Field

abstract:
  The wide-field synoptic sky surveys, known as the Palomar Transient Factory
(PTF) and the intermediate Palomar Transient Factory (iPTF), will accumulate a
large number of known and new RR Lyrae. These RR Lyrae are good tracers to
study the substructure of the Galactic halo if their distance, metallicity, and
galactocentric velocity can be measured. Candidates of halo RR Lyrae can be
identified from their distance and metallicity before requesting spectroscopic
observations for confirmation. This is because both quantities can be obtained
via their photometric light curves, because the absolute V-band magnitude for
RR Lyrae is correlated with metallicity, and the metallicity can be estimated
using a metallicity-light curve relation. To fully utilize the PTF and iPTF
light-curve data in related future work, it is necessary to derive the
metallicity-light curve relation in the native PTF/iPTF R-band photometric
system. In this work, we derived such a relation using the known ab-type RR
Lyrae located in the Kepler field, and it is found to be $[Fe/H]_{PTF} = -4.089
- 7.346 P + 1.280 \phi_{31}$ (where $P$ is pulsational period and $\phi_{31}$
is one of the Fourier parameters describing the shape of the light curve), with
a dispersion of 0.118 dex. We tested our metallicity-light curve relation with
new spectroscopic observations of a few RR Lyrae in the Kepler field, as well
as several data sets available in the literature. Our tests demonstrated that
the derived metallicity-light curve relation could be used to estimate
metallicities for the majority of the RR Lyrae, which are in agreement with the
published values.


title: Asymptotic semi-stability of nilpotent orbits in p-adic Hodge theory

abstract:
  We consider nilpotent orbits on the period domains for the p-adic Hodge
structure analogous to the complex case. We show that, any nilpotent orbit in
the period domain of Hodge-Tate structures converges to a semistable point
(filtration). Furthermore the nilpotent orbits of the limit point are
asymptotic to the twisted period map. The estimates in the theorem are given
with respect to the non-archimedean metric. The result is analogous to the
orbit theorems of W. Schmid on complex Hodge structure. Our proof is based on a
GIT criteria for semi-stability (Kempf-Ness theorem) and estimates from p-adic
(Amice-Schneider) Fourier theory.


title: On the question of genericity of hyperbolic knots

abstract:
  A well-known conjecture in knot theory says that the percentage of hyperbolic
knots amongst all of the prime knots of $n$ or fewer crossings approaches $100$
as $n$ approaches infinity. In this paper, it is proved that this conjecture
contradicts several other plausible conjectures, including the 120-year-old
conjecture on additivity of the crossing number of knots under connected sum
and the conjecture that the crossing number of a satellite knot is not less
than that of its companion.