title: User Selection and Power Allocation in Full Duplex Multi-Cell Networks

abstract:
  Full duplex (FD) communications has the potential to double the capacity of a
half duplex (HD) system at the link level. However, in a cellular network, FD
operation is not a straightforward extension of half duplex operations. The
increased interference due to a large number of simultaneous transmissions in
FD operation and realtime traffic conditions limits the capacity improvement.
Realizing the potential of FD requires careful coordination of resource
allocation among the cells as well as within the cell. In this paper, we
propose a distributed resource allocation, i.e., joint user selection and power
allocation for a FD multi-cell system, assuming FD base stations (BSs) and HD
user equipment (UEs). Due to the complexity of finding the globally optimum
solution, a sub-optimal solution for UE selection, and a novel geometric
programming based solution for power allocation, are proposed. The proposed
distributed approach converges quickly and performs almost as well as a
centralized solution, but with much lower signaling overhead. It provides a
hybrid scheduling policy which allows FD operations whenever it is
advantageous, but otherwise defaults to HD operation. We focus on small cell
systems because they are more suitable for FD operation, given practical
self-interference cancellation limits.With practical self-interference
cancellation, it is shown that the proposed hybrid FD system achieves nearly
two times throughput improvement for an indoor multi-cell scenario, and about
65% improvement for an outdoor multi-cell scenario compared to the HD system.


title:
Cosmic ray muon computed tomography of spent nuclear fuel in dry storage
  casks

abstract:
  Radiography with cosmic ray muon scattering has proven to be a successful
method of imaging nuclear material through heavy shielding. Of particular
interest is monitoring dry storage casks for diversion of plutonium contained
in spent reactor fuel. Using muon tracking detectors that surround a
cylindrical cask, cosmic ray muon scattering can be simultaneously measured
from all azimuthal angles, giving complete tomographic coverage of the cask
interior. This paper describes the first application of filtered back
projection algorithms, typically used in medical imaging, to cosmic ray muon
imaging. The specific application to monitoring spent nuclear fuel in dry
storage casks is investigated via GEANT4 simulations. With a cylindrical muon
tracking detector surrounding a typical spent fuel cask, the cask contents can
be confirmed with high confidence in less than two days exposure. Similar
results can be obtained by moving a smaller detector to view the cask from
multiple angles.


title: Gravitational Wave - Gauge Field Oscillations

abstract:
  Gravitational waves propagating through a stationary gauge field transform
into gauge field waves and back again. When multiple families of flavor-space
locked gauge fields are present, the gravitational and gauge field waves
exhibit novel dynamics. At high frequencies, the system behaves like coupled
oscillators in which the gravitational wave is the central pacemaker. Due to
energy conservation and exchange among the oscillators, the wave amplitudes lie
on a multidimensional sphere, reminiscent of neutrino flavor oscillations. This
phenomenon has implications for cosmological scenarios based on flavor-space
locked gauge fields.


title: Comparison estimates for linear forms in additive number theory

abstract:
  Let $R$ be a commutative ring $R$ with $1_R$ and with group of units
$R^{\times}$. Let $\Phi = \Phi(t_1,\ldots, t_h) = \sum_{i=1}^h \varphi_it_i$ be
an $h$-ary linear form with nonzero coefficients $\varphi_1,\ldots, \varphi_h
\in R$. Let $M$ be an $R$-module. For every subset $A$ of $M$, the image of $A$
under $\Phi$ is \[ \Phi(A) = \{ \Phi(a_1,\ldots, a_h) : (a_1,\ldots, a_h) \in
A^h \}. \] For every subset $I$ of $\{1,2,\ldots, h\}$, there is the subset sum
$ s_I = \sum_{i\in I} \varphi_i. $ Let $ \mathcal{S} (\Phi) = \{s_I: \emptyset
\neq I \subseteq \{1,2,\ldots, h\} \}. $
  Theorem. Let $\Upsilon(t_1,\ldots, t_g) = \sum_{i=1}^g \upsilon_it_i$ and
$\Phi(t_1,\ldots, t_h) = \sum_{i=1}^h \varphi_it_i$ be linear forms with
nonzero coefficients in the ring $R$. If $\{0, 1\} \subseteq \mathcal{S}
(\Upsilon)$ and $\mathcal{S} (\Phi) \subseteq R^{\times}$, then for every
$\varepsilon > 0$ and $c > 1$ there exist a finite $R$-module $M$ with $|M| >
c$ and a subset $A$ of $M$ such that $\Upsilon(A \cup \{0\}) = M$ and
$|\Phi(A)| < \varepsilon |M|$.


title: Ultraharmonics and Secondary Spiral Wakes Induced by a Planet

abstract:
  We investigate the ultraharmonics response of a protoplanetary disk to an
orbiting planet. We find that the multi-armed spiral structure can be excited
by the higher-order forcing due to nonlinear mode-coupling. In particular, the
preferential excitation of gas response with small azimuthal wavenumber $(m\sim
2)$ is a direct consequence of mode-coupling among linear waves. The presence
of multiple Fourier components in a planet's potential is a distinct feature
compared to the previous studies in the context of spiral galaxies, which turns
out to be crucial for the generation of ultraharmonics waves. This analysis may
shed light on understanding some results regarding the spiral structures
excited by a massive planet.


title: Early Time Dynamics of Gluon Fields in High Energy Nuclear Collisions

abstract:
  Nuclei colliding at very high energy create a strong, quasi-classical gluon
field during the initial phase of their interaction. We present an analytic
calculation of the initial space-time evolution of this field in the limit of
very high energies using a formal recursive solution of the Yang-Mills
equations. We provide analytic expressions for the initial chromo-electric and
chromo-magnetic fields and for their energy-momentum tensor. In particular, we
discuss event-averaged results for energy density and energy flow as well as
for longitudinal and transverse pressure of this system. Our results are
generally applicable if $\tau < 1/Q_s$. The transverse energy flow of the gluon
field exhibits hydrodynamic-like contributions that follow transverse gradients
of the energy density. In addition, a rapidity-odd energy flow also emerges
from the non-abelian analog of Gauss' Law and generates non-vanishing angular
momentum of the field. We will discuss the space-time picture that emerges from
our analysis and its implications for observables in heavy ion collisions.


title:
Minimax optimal convex methods for Poisson inverse problems under
  $\ell_q$-ball sparsity

abstract:
  In this paper, we study the minimax rates and provide an implementable convex
algorithm for Poisson inverse problems under weak sparsity and physical
constraints. In particular we assume the model $y_i \sim
\mbox{Poisson}(Ta_i^{\top}f^*)$ for $1 \leq i \leq n$ where $T \in
\mathbb{R}_+$ is the intensity, and we impose weak sparsity on $f^* \in
\mathbb{R}^p$ by assuming $f^*$ lies in an $\ell_q$-ball when rotated according
to an orthonormal basis $D \in \mathbb{R}^{p \times p}$. In addition, since we
are modeling real physical systems we also impose positivity and
flux-preserving constraints on the matrix $A = [a_1, a_2,...,a_n]^{\top}$ and
the function $f^*$. We prove minimax lower bounds for this model which scale as
$R_q (\frac{\log p}{T})^{1 - q/2}$ where it is noticeable that the rate depends
on the intensity $T$ and not the sample size $n$. We also show that a
$\ell_1$-based regularized least-squares estimator achieves this minimax lower
bound, provided a suitable restricted eigenvalue condition is satisfied.
Finally we prove that provided $n \geq \tilde{K} \log p$ where $\tilde{K} =
O(R_q (\frac{\log p}{T})^{- q/2})$ represents an approximate sparsity level,
our restricted eigenvalue condition and physical constraints are satisfied for
random bounded ensembles. We also provide numerical experiments that validate
our mean-squared error bounds. Our results address a number of open issues from
prior work on Poisson inverse problems that focuses on strictly sparse models
and does not provide guarantees for convex implementable algorithms.


title:
On the Complexity of Solving Zero-Dimensional Polynomial Systems via
  Projection

abstract:
  Given a zero-dimensional polynomial system consisting of n integer
polynomials in n variables, we propose a certified and complete method to
compute all complex solutions of the system as well as a corresponding
separating linear form l with coefficients of small bit size. For computing l,
we need to project the solutions into one dimension along O(n) distinct
directions but no further algebraic manipulations. The solutions are then
directly reconstructed from the considered projections. The first step is
deterministic, whereas the second step uses randomization, thus being
Las-Vegas.
  The theoretical analysis of our approach shows that the overall cost for the
two problems considered above is dominated by the cost of carrying out the
projections. We also give bounds on the bit complexity of our algorithms that
are exclusively stated in terms of the number of variables, the total degree
and the bitsize of the input polynomials.


title:
Asymmetric mass acquisition in LaBi - a new topological semimetal
  candidate

abstract:
  We use our high resolution He-lamp based, tunable laser-based ARPES
measurements and density functional theory calculations to study the electronic
properties of LaBi, a binary system that was proposed to be a member of a new
family of topological semimetals. Both bulk and surface bands are present in
the spectra. The dispersion of the surface state is highly unusual. It
resembles a Dirac cone, but upon closer inspection we can clearly detect an
energy gap. The bottom band follows roughly a parabolic dispersion. The
dispersion of the top band remains very linear, "V" shape like, with the tip
approaching very closely to the extrapolated location of Dirac point. Such
asymmetric mass acquisition is highly unusual and opens a possibility of a new
topological phenomena that has yet to be understood.


title:
Isotropy-Violation Diagnostics for $B$-mode Polarization Foregrounds to
  the Cosmic Microwave Background

abstract:
  Isotropy-violation statistics can highlight polarized galactic foregrounds
that contaminate primordial $B$-modes in the Cosmic Microwave Background (CMB).
We propose a particular isotropy-violation test and apply it to polarized
Planck 353 GHz data, constructing an map that indicates $B$-mode foreground
dust power over the sky. We build our main isotropy test in harmonic space via
the bipolar spherical harmonic basis, and our method helps us to identify the
least-contaminated directions. By this measure, there are regions of low
foreground in and around the BICEP field, near the South Galactic Pole, and in
the Northern Galactic Hemisphere. There is also a possible foreground feature
in the BICEP field. We compare our results to those based on the local power
spectrum, which is computed on discs using a version of the method of Planck
Int.~XXX (2016). The discs method is closely related to our isotropy-violation
diagnostic. We pay special care to the treatment of noise, including chance
correlations with the foregrounds. Currently we use our isotropy tool to assess
the cleanest portions of the sky, but in the future such methods will allow
isotropy-based null tests for foreground contamination in maps purported to
measure primordial $B$-modes, particularly in cases of limited frequency
coverage.


title:
L\'evy area with a drift as a renormalization limit of Markov chains on
  periodic graphs

abstract:
  A careful look at rough path topology applied to Brownian motion reveals new
possible properties of the well-known L\'evy area, in particular the presence
of an intrinsic drift of this area. Using renormalization limit of Markov
chains on periodic graphs, we present a construction of such a non-trivial
drift and give an explicit formula for it. Several examples for which explicit
computations are made are included.


title: Ca$_3$Ir$_4$Sn$_{13}$: A weakly correlated nodeless superconductor

abstract:
  We report detailed Seebeck coefficient, Hall resistivity as well as specific
heat measurement on Ca$_3$Ir$_4$Sn$_{13}$ single crystals. The Seebeck
coefficient exhibits a peak corresponding to the anomaly in resistivity at
$T^*$, and the carrier density is suppressed significantly below $T^*$. This
indicates a significant Fermi surface reconstruction and the opening of the
charge density wave gap at the supperlattice transition. The magnetic field
induced enhancement of the residual specific heat coefficient $\gamma(H)$
exhibits a nearly linear dependence on magnetic field, indicating a nodeless
gap. In the temperature range close to $T_c$ the Seebeck coefficient can be
described well by the diffusion model. The zero-temperature extrapolated
thermoelectric power is very small, implying large normalized Fermi
temperature. Consequently the ratio $\frac{T_c}{T_F}$ is very small. Our
results indicate that Ca$_3$Ir$_4$Sn$_{13}$ is a weakly correlated nodeless
superconductor.


title: Joint Statistics of Random Walk on $Z^1$ and Accumulation of Visits

abstract:
  We obtain the joint distribution $P_N (X, K|Z)$ of the location $X$ of a
one-dimensional symmetric next neighbor random walk on the integer lattice, and
the number of times the walk has visited a specified site $Z$. This
distribution has a simple form in terms of the one variable distribution
$p_{N'}(X')$, where $N'=N-K$ and $X'$ is a function of $X, K$, and $Z$. The
marginal distribution of $X$ and $K$ are obtained, as well as their diffusion
scaling limits.


title:
Honolulu Rail Transit: International Lessons from Barcelona in Linking
  Urban Form, Design, and Transportation

abstract:
  The city of Honolulu, Hawaii is currently planning and developing a new rail
transit system. While Honolulu has supportive density and topography for rail
transit, questions remain about its ability to effectively integrate urban
design and accessibility across the system. Every transit trip begins and ends
with a walking trip from origins and to destinations: transportation planning
must account for pedestrian safety, comfort, and access. Ildefons Cerda's 19th
century utopian plan for Barcelona's Eixample district produced a renowned,
livable urban form. The Eixample, with its well-integrated rail transit, serves
as a model of urban design, land use, transportation planning, and
pedestrian-scaled streets working in synergy to produce accessibility. This
study discusses the urban form of Honolulu and the history and planning of its
new rail transit system. Then it reviews the history of Cerda's plan for the
Eixample and discusses its urban form and performance today. Finally it draws
several lessons from Barcelona's urban design, accessibility, and rail transit
planning and critically discusses their applicability to policy and design in
Honolulu. This discussion is situated within wider debates around livable
cities and social justice as it contributes several form and design lessons to
the livability and accessibility literature while identifying potential
concerns with privatization and displacement.


title: Predicting the direction of stock market prices using random forest

abstract:
  Predicting trends in stock market prices has been an area of interest for
researchers for many years due to its complex and dynamic nature. Intrinsic
volatility in stock market across the globe makes the task of prediction
challenging. Forecasting and diffusion modeling, although effective can't be
the panacea to the diverse range of problems encountered in prediction,
short-term or otherwise. Market risk, strongly correlated with forecasting
errors, needs to be minimized to ensure minimal risk in investment. The authors
propose to minimize forecasting error by treating the forecasting problem as a
classification problem, a popular suite of algorithms in Machine learning. In
this paper, we propose a novel way to minimize the risk of investment in stock
market by predicting the returns of a stock using a class of powerful machine
learning algorithms known as ensemble learning. Some of the technical
indicators such as Relative Strength Index (RSI), stochastic oscillator etc are
used as inputs to train our model. The learning model used is an ensemble of
multiple decision trees. The algorithm is shown to outperform existing algo-
rithms found in the literature. Out of Bag (OOB) error estimates have been
found to be encouraging. Key Words: Random Forest Classifier, stock price
forecasting, Exponential smoothing, feature extraction, OOB error and
convergence.


title:
Tidal stirring of satellites with shallow density profiles prevents them
  from being too big to fail

abstract:
  The "too big to fail" problem is revisited by studying the tidal evolution of
populations of dwarf satellites with different density profiles. The high
resolution cosmological $\rm \Lambda CDM$ "ErisMod" set of simulations is used.
These simulations can model both the stellar and dark matter components of the
satellites, and their evolution under the action of the tides of a MW-sized
host halo at a force resolution better than 10 pc. The stronger tidal mass loss
and re-shaping of the mass distribution induced in satellites with $\gamma=0.6$
dark matter density distributions, as those resulting from the effect of
feedback in hydrodynamical simulations of dwarf galaxy formation, is sufficient
to bring the circular velocity profiles in agreement with the kinematics of
MW's dSphs. In contrast, in simulations in which the satellites retain cusps at
$z=0$ there are several "massive failures" with circular velocities in excess
of the observational constraints. Various sources of deviations in the
conventionally adopted relation between the circular velocity at the half light
radius and the one dimensional line-of-sight velocity dispersions are found.
Such deviations are caused by the response of circular velocity profiles to
tidal effects, which also varies depending on the initially assumed inner
density profile, and by the complexity of the stellar kinematics, which include
residual rotation and anisotropy. In addition tidal effects naturally induce
large deviations in the stellar mass-halo mass relation for halo masses below
$\rm 10^9 ~ M_{\odot}$, preventing any reliable application of the abundance
matching technique to dwarf galaxy satellites.


title: A non-Abelian Black Ring

abstract:
  We construct a supersymmetric black ring solution of SU(2) N=1, d=5
Super-Einstein-Yang-Mills (SEYM) theory by adding a distorted BPST instanton to
an Abelian black ring solution of the same theory. The change cannot be
observed from spatial infinity: neither the mass, nor the angular momenta or
the values of the scalars at infinity differ from those of the Abelian ring.
The entropy is, however, sensitive to the presence of the non-Abelian
instanton, and it is smaller than that of the Abelian ring, in analogy to what
happens in the supersymmetric coloured black holes recently constructed in the
same theory and in N=2, d=4 SEYM. By taking the limit in which the two angular
momenta become equal we derive a non-Abelian generalization of the BMPV
rotating black-hole solution.


title: The multiplicity of 250-$\mu$m Herschel sources in the COSMOS field

abstract:
  We investigate the multiplicity of extragalactic sources detected by the
Herschel Space Observatory in the COSMOS field. Using 3.6- and 24-$\mu$m
catalogues, in conjunction with 250-$\mu$m data from Herschel, we seek to
determine if a significant fraction of Herschel sources are composed of
multiple components emitting at 250 $\mu$m. We use the XID+ code, using
Bayesian inference methods to produce probability distributions of the possible
contributions to the observed 250-$\mu$m flux for each potential component. The
fraction of Herschel flux assigned to the brightest component is highest for
sources with total 250-$\mu$m fluxes < 45 mJy; however, the flux in the
brightest component is still highest in the brightest Herschel sources. The
faintest 250-$\mu$m sources (30-45 mJy) have the majority of their flux
assigned to a single bright component; the second brightest component is
typically significantly weaker, and contains the remainder of the 250-$\mu$m
source flux. At the highest 250-$\mu$m fluxes (45-110 mJy), the brightest and
second brightest components are assigned roughly equal fluxes, and together are
insufficient to reach 100 per cent of the 250-$\mu$m source flux. This
indicates that additional components are required, beyond the brightest two
components, to reproduce the observed flux. 95 per cent of the sources in our
sample have a second component that contains more than 10 per cent of the total
source flux. Particularly for the brightest Herschel sources, assigning the
total flux to a single source may overestimate the flux contributed by around
150 per cent.


title:
Bounds on the local energy density of holographic CFTs from bulk
  geometry

abstract:
  The stress tensor is a basic local operator in any field theory; in the
context of AdS/CFT, it is the operator which is dual to the bulk geometry
itself. Here we exploit this feature by using the bulk geometry to place
constraints on the local energy density in static states of holographic
$(2+1)$-dimensional CFTs living on a closed (but otherwise generally curved)
spatial geometry. We allow for the presence of a marginal scalar deformation,
dual to a massless scalar field in the bulk. For certain vacuum states in which
the bulk geometry is well-behaved at zero temperature, we find that the bulk
equations of motion imply that the local energy density integrated over
specific boundary domains is negative. In the absence of scalar deformations,
we use the inverse mean curvature flow to show that if the CFT spatial geometry
has spherical topology but non-constant curvature, the local energy density
must be positive somewhere. This result extends to other topologies, but only
for certain types of vacuum; in particular, for a generic toroidal boundary,
the vacuum's bulk dual must be the zero-temperature limit of a toroidal black
hole.


title: Lensing of Fast Radio Bursts as a Probe of Compact Dark Matter

abstract:
  The possibility that part of the dark matter is made of massive compact halo
objects (MACHOs) remains poorly constrained over a wide range of masses, and
especially in the $20-100\, M_\odot$ window. We show that strong gravitational
lensing of extragalactic fast radio bursts (FRBs) by MACHOs of masses larger
than $\sim20\,M_\odot$ would result in repeated FRBs with an observable time
delay. Strong lensing of an FRB by a lens of mass $M_L$ induces two images,
separated by a typical time delay $\sim$ few $\times(M_L/30\, M_\odot)$
milliseconds. Considering the expected FRB detection rate by upcoming
experiments, such as CHIME, of $10^4$ FRBs per year, we should observe from
tens to hundreds of repeated bursts yearly, if MACHOs in this window make up
all the dark matter. A null search for echoes with just $10^4$ FRBs, would
constrain the fraction $f_{\rm DM}$ of dark matter in MACHOs to $f_{\rm
DM}\lesssim 0.08$ for $M_L\gtrsim 20\,M_\odot$.


title:
A large difference in the progenitor masses of active and passive
  galaxies in the EAGLE simulation

abstract:
  Cumulative number density matching of galaxies is a method to observationally
connect descendent galaxies to their typical main progenitors at higher
redshifts and thereby to assess the evolution of galaxy properties. The
accuracy of this method is limited due to galaxy merging and scatter in the
stellar mass growth history of individual galaxies. Behroozi et al. (2013) have
introduced a refinement of the method, based on abundance matching of observed
galaxies to the Bolshoi dark-matter-only simulation. The EAGLE cosmological
hydro-simulation is well suited to test this method, because it reproduces the
observed evolution of the galaxy stellar mass function and the passive
fraction. We find agreement with the Behroozi et al. (2013) method for the
complete sample of main progenitors of z = 0 galaxies, but we also find a
strong dependence on the current star formation rate. Passive galaxies with a
stellar mass up to 10^10.75 Msun have a completely different median mass
history than active galaxies of the same mass. This difference persists if we
only select central galaxies. This means that the cumulative number density
method should be applied separately to active and passive galaxies. Even then,
the typical main progenitor of a z = 0 galaxy already spans two orders of
magnitude in stellar mass at z = 2.


title: Coulomb branches for rank 2 gauge groups in 3d N=4 gauge theories

abstract:
  The Coulomb branch of 3-dimensional N=4 gauge theories is the space of bare
and dressed BPS monopole operators. We utilise the conformal dimension to
define a fan which, upon intersection with the weight lattice of a GNO-dual
group, gives rise to a collection of semi-groups. It turns out that the unique
Hilbert bases of these semi-groups are a sufficient, finite set of monopole
operators which generate the entire chiral ring. Moreover, the knowledge of the
properties of the minimal generators is enough to compute the Hilbert series
explicitly. The techniques of this paper allow an efficient evaluation of the
Hilbert series for general rank gauge groups. As an application, we provide
various examples for all rank two gauge groups to demonstrate the novel
interpretation.


title:
How well can new particles interacting with neutrinos be constrained
  after a galactic supernova?

abstract:
  A supernova event in our own galaxy will result in a large number of
neutrinos detected on Earth within the time-frame of a few seconds. These
neutrinos will have been produced thermally with, in principle, three distinct
temperatures for the electron, anti-electron and remaining heavy flavours
respectively. We revisit the possibility that new MeV-mass particles $\chi$ are
also produced thermally during the event, which scatter with the neutrinos and
alter their temperatures. Our main emphasis is on the detectability of this
effect using the neutrino spectrum, given the large uncertainty on the
temperature and density profiles of the stellar matter. By marginalising over
the parameters of a simple analytic model for the stellar profile, we find that
Super Kamiokande could place an upper limit on the scattering cross section at
the level of $\sigma_{\chi \nu} \sim 10^{-40} \cdot (T / \mathrm{MeV})^2$
cm$^2$ for 10 MeV mass particles at 90% confidence. A direct-detection-like
experiment would be less susceptible to systematic uncertainties in the
neutrino production and mixing, but this would need a target mass around 100
tonnes in order to acquire enough statistics to compete with Super Kamiokande.


title: How many hypersurfaces does it take to cut out a Segre class?

abstract:
  We prove an identity of Segre classes for zero-schemes of compatible sections
of two vector bundles. Applications include bounds on the number of equations
needed to cut out a scheme with the same Segre class as a given subscheme of
(for example) a projective variety, and a `Segre-Bertini' theorem controlling
the behavior of Segre classes of singularity subschemes of hypersurfaces under
general hyperplane sections.
  These results interpolate between an observation of Samuel concerning
multiplicities along components of a subscheme and facts concerning the
integral closure of corresponding ideals. The Segre-Bertini theorem has
applications to characteristic classes of singular varieties. The main results
are motivated by the problem of computing Segre classes explicitly and
applications of Segre classes to enumerative geometry.


title:
The LHC Diphoton excess at 750 GeV in the framework of the Constrained
  Minimal Supersymmetric Standard Model

abstract:
  We examine the observed diphoton excess at 750 GeV in the framework of
constrained Minimal Supersymmetric Standard Model (cMSSM). The consistency of
cMSSM with the discovery of a 125 GeV Higgs boson and PLANCK/WMAP data for dark
matter relic density (RD) demands large mixing in the scalar top (stop) sector
and consequently, the existence of a light stop quasi-degenerate with the
lightest neutralino. Small decay width due to kinematic and loop suppression of
such a stop allows for the existence of stop-antistop bound states (stoponia).
Identifying the particular part of cMSSM parameter space consistent with Higgs
boson mass as well as RD, we study stoponia as the source of the diphoton
excess.


title:
String-Theory-Based Predictions for Nonhydrodynamic Collective Modes in
  Strongly Interacting Fermi Gases

abstract:
  Very different strongly interacting quantum systems such as Fermi gases,
quark-gluon plasmas formed in high energy ion collisions and black holes
studied theoretically in string theory are known to exhibit quantitatively
similar damping of hydrodynamic modes. It is not known if such similarities
extend beyond the hydrodynamic limit. Do non-hydrodynamic collective modes in
Fermi gases with strong interactions also match those from string theory
calculations? In order to answer this question, we use calculations based on
string theory to make predictions for novel types of modes outside the
hydrodynamic regime in trapped Fermi gases. These predictions are amenable to
direct testing with current state-of-the-art cold atom experiments.


title:
Nonparametric M-estimation for right censored regression model with
  stationary ergodic data

abstract:
  The present paper deals with a nonparametric M-estimation for right censored
regression model with stationary ergodic data. Defined as an implicit function,
a kernel type estimator of a family of robust regression is considered when the
covariate take its values in R^d (d >= 1) and the data are sampled from
stationary ergodic process. The strong consistency (with rate) and the
asymptotic distribution of the estimator are established under mild
assumptions. Moreover, a usable confidence interval is provided which does not
depend on any unknown quantity. Our results hold without any mixing condition
and do not require the existence of marginal densities. A comparison study
based on simulated data is also provided.


title:
First Limits on the 21 cm Power Spectrum during the Epoch of X-ray
  heating

abstract:
  We present first results from radio observations with the Murchison Widefield
Array seeking to constrain the power spectrum of 21 cm brightness temperature
fluctuations between the redshifts of 11.6 and 17.9 (113 and 75 MHz). Three
hours of observations were conducted over two nights with significantly
different levels of ionospheric activity. We use these data to assess the
impact of systematic errors at low frequency, including the ionosphere and
radio-frequency interference, on a power spectrum measurement. We find that
after the 1-3 hours of integration presented here, our measurements at the
Murchison Radio Observatory are not limited by RFI, even within the FM band,
and that the ionosphere does not appear to affect the level of power in the
modes that we expect to be sensitive to cosmology. Power spectrum detections,
inconsistent with noise, due to fine spectral structure imprinted on the
foregrounds by reflections in the signal-chain, occupy the spatial Fourier
modes where we would otherwise be most sensitive to the cosmological signal. We
are able to reduce this contamination using calibration solutions derived from
autocorrelations so that we achieve an sensitivity of $10^4$ mK on comoving
scales $k\lesssim 0.5 h$Mpc$^{-1}$. This represents the first upper limits on
the $21$ cm power spectrum fluctuations at redshifts $12\lesssim z \lesssim 18$
but is still limited by calibration systematics. While calibration improvements
may allow us to further remove this contamination, our results emphasize that
future experiments should consider carefully the existence of and their ability
to calibrate out any spectral structure within the EoR window.


title: deepMiRGene: Deep Neural Network based Precursor microRNA Prediction

abstract:
  Since microRNAs (miRNAs) play a crucial role in post-transcriptional gene
regulation, miRNA identification is one of the most essential problems in
computational biology. miRNAs are usually short in length ranging between 20
and 23 base pairs. It is thus often difficult to distinguish miRNA-encoding
sequences from other non-coding RNAs and pseudo miRNAs that have a similar
length, and most previous studies have recommended using precursor miRNAs
instead of mature miRNAs for robust detection. A great number of conventional
machine-learning-based classification methods have been proposed, but they
often have the serious disadvantage of requiring manual feature engineering,
and their performance is limited as well. In this paper, we propose a novel
miRNA precursor prediction algorithm, deepMiRGene, based on recurrent neural
networks, specifically long short-term memory networks. deepMiRGene
automatically learns suitable features from the data themselves without manual
feature engineering and constructs a model that can successfully reflect
structural characteristics of precursor miRNAs. For the performance evaluation
of our approach, we have employed several widely used evaluation metrics on
three recent benchmark datasets and verified that deepMiRGene delivered
comparable performance among the current state-of-the-art tools.


title: Integrable M\"obius invariant evolutionary lattices of second order

abstract:
  We solve the classification problem for integrable lattices of the form
$u_{,t}=f(u_{-2},\dots,u_2)$ under the additional assumption of invariance with
respect to the group of linear-fractional transformations. The obtained list
contains 5 equations, including 3 new. Difference Miura type substitutions are
found which relate these equations with known polynomial lattices. We also
present some classification results for the generic lattices.


title: Sharp Bounds Between Two R\'enyi Entropies of Distinct Positive Orders

abstract:
  Many axiomatic definitions of entropy, such as the R\'enyi entropy, of a
random variable are closely related to the $\ell_{\alpha}$-norm of its
probability distribution. This study considers probability distributions on
finite sets, and examines the sharp bounds of the $\ell_{\beta}$-norm with a
fixed $\ell_{\alpha}$-norm, $\alpha \neq \beta$, for $n$-dimensional
probability vectors with an integer $n \ge 2$. From the results, we derive the
sharp bounds of the R\'enyi entropy of positive order $\beta$ with a fixed
R\'enyi entropy of another positive order $\alpha$. As applications, we
investigate sharp bounds of Ariomoto's mutual information of order $\alpha$ and
Gallager's random coding exponents for uniformly focusing channels under the
uniform input distribution.


title: Locally Repairable Regenerating Code Constructions

abstract:
  In this work, we give locally repairable regenerating code (LRRC) [1]-[3],
[5], [6] constructions that can protect the file size promised by the graph
analysis of the modified family helper selection (MFHS) scheme [1] at the
minimum-bandwidth-regenerating (MBR) point.


title:
deBInfer: Bayesian inference for dynamical models of biological systems
  in R

abstract:
  1. Understanding the mechanisms underlying biological systems, and
ultimately, predicting their behaviours in a changing environment requires
overcoming the gap between mathematical models and experimental or
observational data. Differential equations (DEs) are commonly used to model the
temporal evolution of biological systems, but statistical methods for comparing
DE models to data and for parameter inference are relatively poorly developed.
This is especially problematic in the context of biological systems where
observations are often noisy and only a small number of time points may be
available. 2. The Bayesian approach offers a coherent framework for parameter
inference that can account for multiple sources of uncertainty, while making
use of prior information. It offers a rigorous methodology for parameter
inference, as well as modelling the link between unobservable model states and
parameters, and observable quantities. 3. We present deBInfer, a package for
the statistical computing environment R, implementing a Bayesian framework for
parameter inference in DEs. deBInfer provides templates for the DE model, the
observation model and data likelihood, and the model parameters and their prior
distributions. A Markov chain Monte Carlo (MCMC) procedure processes these
inputs to estimate the posterior distributions of the parameters and any
derived quantities, including the model trajectories. Further functionality is
provided to facilitate MCMC diagnostics, the visualisation of the posterior
distributions of model parameters and trajectories, and the use of compiled DE
models for improved computational performance. 4. The templating approach makes
deBInfer applicable to a wide range of DE models. We demonstrate its
application to ordinary and delay DE models for population ecology.


title:
Viscous effects on the Rayleigh-Taylor instability with background
  temperature gradient

abstract:
  The growth rate of the compressible Rayleigh-Taylor instability is studied in
the presence of a background temperature gradient, $\Theta$, using a normal
mode analysis. The effect of $\Theta$ variation is examined for three interface
types corresponding to combinations of the viscous properties of the fluids
(inviscid-inviscid, viscous-viscous and viscous-inviscid) at different Atwood
numbers, $At$, and, when at least one of the fluids' viscosity is non-zero, as
a function of the Grashof number. For the general case, the resulting ordinary
differential equations are solved numerically; however, dispersion relations
for the growth rate are presented for several limiting cases. An analytical
solution is found for the inviscid-inviscid interface and the corresponding
dispersion equation for the growth rate is obtained in the limit of a large
$\Theta$. For the viscous-inviscid case, a dispersion relation is derived in
the incompressible limit and $\Theta=0$. Compared to $\Theta=0$ case, the role
of $\Theta<0$ (hotter light fluid) is destabilizing and becomes stabilizing
when $\Theta>0$ (colder light fluid). The most pronounced effect when
$\Theta\neq 0$ is found at low $At$ and/or at large perturbation wavelengths
relative to the domain size for all interface types. On the other hand, at
small perturbation wavelengths relative to the domain size, the growth rate for
$\Theta<0$ case exceeds the infinite domain incompressible constant density
result. The results are applied to two practical examples, using sets of
parameters relevant to Inertial Confinement Fusion coasting stage and solar
corona plumes. The role of viscosity on the growth rate reduction is discussed
together with highlighting the range of wavenumbers most affected by viscosity.
The viscous effects further increase in the presence of background temperature
gradient, when the viscosity is temperature dependent.


title: Shaping a single photon without interacting with it

abstract:
  Complete control over the properties of light up to the level of single
photons is an invaluable tool for quantum information science and fundamental
studies of light-matter interaction. The crucial prerequisite is the ability to
create a spatio-temporal distribution of single-photon electromagnetic field
with the desired characteristics, i.e. to shape a photon by design. Despite the
ever-growing demand for tuneable single-photon sources, there is a lack of
practical, efficient and scalable methods for photon shaping. Here we put
forward a novel generic method that enables lossless shaping of single photons
with respect to any degree of freedom or several degrees of freedom
simultaneously. Shaping is performed in a heralded manner, which ensures
flexibility and scalability of the scheme. Our method can be directly
integrated with the current technologies: this enables experimental realization
of numerous proposals involving shaped single photons and opens up
qualitatively new opportunities in the future.


title:
Intermittency for the Hyperbolic Anderson Model with rough noise in
  space

abstract:
  In this article, we consider the stochastic wave equation on the real line
driven by a linear multiplicative Gaussian noise, which is white in time and
whose spatial correlation corresponds to that of a fractional Brownian motion
with Hurst index $H\in (\frac14,\frac12)$. Initial data are assumed to be
constant. First, we prove that this equation has a unique solution (in the
Skorohod sense) and obtain an exponential upper bound for the $p$-th moment of
the solution, for any $p\geq 2$. Condition $H>\frac14$ turns out to be
necessary for the existence of solution. Secondly, we show that this solution
coincides with the one obtained by the authors in a recent publication, in
which the solution is interpreted in the It\^o sense. Finally, we prove that
the solution of the equation in the Skorohod sense is weakly intermittent.


title:
Impact of guided reflection with peers on the development of effective
  problem solving strategies and physics learning

abstract:
  Students must learn effective problem solving strategies in order to develop
expertise in physics. Effective problem solving strategies include a conceptual
analysis of the problem followed by planning of the solution, and then
implementation, evaluation and reflection upon the process. Research suggests
that converting a problem from the initial verbal representation to other
suitable representation, e.g., diagrammatic representation, during the initial
conceptual analysis can facilitate further analysis of the problem.6 But
without guidance, many introductory physics students solve problems using
superficial clues and cues and do not perceive problem solving as an
opportunity for learning. Here, we describe a study which suggests that
engaging students in reflection with peers about effective problem solving
strategies while effective approaches are modeled for them and prompt feedback
is provided may enhance desirable skills.


title:
A Distributed Model Predictive Control Framework for Road-Following
  Formation Control of Car-like Vehicles (Extended Version)

abstract:
  This work presents a novel framework for the formation control of multiple
autonomous ground vehicles in an on-road environment. Unique challenges of this
problem lie in 1) the design of collision avoidance strategies with obstacles
and with other vehicles in a highly structured environment, 2) dynamic
reconfiguration of the formation to handle different task specifications. In
this paper, we design a local MPC-based tracking controller for each individual
vehicle to follow a reference trajectory while satisfying various constraints
(kinematics and dynamics, collision avoidance, \textit{etc.}). The reference
trajectory of a vehicle is computed from its leader's trajectory, based on a
pre-defined formation tree. We use logic rules to organize the collision
avoidance behaviors of member vehicles. Moreover, we propose a methodology to
safely reconfigure the formation on-the-fly. The proposed framework has been
validated using high-fidelity simulations.


title: Nature's Book Keeping System

abstract:
  Establishing how one should describe and study natures fundamental degrees of
freedom is a notoriously difficult problem. It is tempting to assume that the
number of bits (or qubits) needed in a given Planckian 3-volume, or perhaps
2-volume, is a fixed finite number, but this ansatz does not make the problem
much easier. We come not even close to solving this problem, but we propose
various ingredients in phrasing the questions, possibilities and limitations
that may serve as starting points.


title: Confinement of Vibrational Modes in Nanocrystalline Silicon

abstract:
  It is possible to confine vibrational modes to silicon nanocrystals by
encapsulating them within hydrogenated amorphous silicon. This is not because
of the small impedance mismatch between materials but, rather, is due to higher
order moments in the distribution of density and stiffness in the amorphous
phase--i.e. it is a result of material substructure. The concept is elucidated
using an idealized one-dimensional setting and then demonstrated for a
realistic nanocrystalline geometry. Beyond the immediate focus on amorphous
encapsulation, this offers the prospect of specifically engineering higher
order property distributions as an alternate means of managing phonons. The
approach could be applied, for instance, to design deterministically ordered
materials which exploit this means of control.


title:
Multi-Atlas Segmentation using Partially Annotated Data: Methods and
  Annotation Strategies

abstract:
  Multi-atlas segmentation is a widely used tool in medical image analysis,
providing robust and accurate results by learning from annotated atlas
datasets. However, the availability of fully annotated atlas images for
training is limited due to the time required for the labelling task.
Segmentation methods requiring only a proportion of each atlas image to be
labelled could therefore reduce the workload on expert raters tasked with
annotating atlas images. To address this issue, we first re-examine the
labelling problem common in many existing approaches and formulate its solution
in terms of a Markov Random Field energy minimisation problem on a graph
connecting atlases and the target image. This provides a unifying framework for
multi-atlas segmentation. We then show how modifications in the graph
configuration of the proposed framework enable the use of partially annotated
atlas images and investigate different partial annotation strategies. The
proposed method was evaluated on two Magnetic Resonance Imaging (MRI) datasets
for hippocampal and cardiac segmentation. Experiments were performed aimed at
(1) recreating existing segmentation techniques with the proposed framework and
(2) demonstrating the potential of employing sparsely annotated atlas data for
multi-atlas segmentation.


title:
Optimization of multilayered nanotubes for maximal scattering
  cancellation

abstract:
  An optimization for multilayered nanotubes that minimizes the scattering
efficiency for a given polarization is derived. The cylindrical nanocavities
have a radially periodic distribution, and the marginal layers that play a
crucial role particularly in the presence of nonlocalities are disposed to
reduce the scattering efficiency up to two orders of magnitude in comparison
with previous proposals. The predominant causes leading to such invisibility
effect are critically discussed. A transfer-matrix formalism is additionally
developed for the fast estimation of the scattering efficiency of the
nanostructures.


title: Deep Convolutional Neural Networks on Cartoon Functions

abstract:
  Wiatowski and B\"olcskei, 2015, proved that deformation stability and
vertical translation invariance of deep convolutional neural network-based
feature extractors are guaranteed by the network structure per se rather than
the specific convolution kernels and non-linearities. While the translation
invariance result applies to square-integrable functions, the deformation
stability bound holds for band-limited functions only. Many signals of
practical relevance (such as natural images) exhibit, however, sharp and curved
discontinuities and are, hence, not band-limited. The main contribution of this
paper is a deformation stability result that takes these structural properties
into account. Specifically, we establish deformation stability bounds for the
class of cartoon functions introduced by Donoho, 2001.


title: Edge phonons in black phosphorus

abstract:
  Exfoliated black phosphorus has recently emerged as a new two-dimensional
crystal that, due to its peculiar and anisotropic crystalline and electronic
band structures, may have potentially important applications in electronics,
optoelectronics and photonics. Despite the fact that the edges of layered
crystals host a range of singular properties whose characterization and
exploitation are of utmost importance for device development, the edges of
black phosphorus remain poorly characterized. In this work, the atomic
structure and the behavior of phonons near different black phosphorus edges are
experimentally and theoretically studied using Raman spectroscopy and density
functional theory calculations. Polarized Raman results show the appearance of
new modes at the edges of the sample, and their spectra depend on the atomic
structure of the edges (zigzag or armchair). Theoretical simulations confirm
that the new modes are due to edge phonon states that are forbidden in the
bulk, and originated from the lattice termination rearrangements.


title: A framework for philosophical biology

abstract:
  Advances in biology have mostly relied on theories that were subsequently
revised, expanded or eventually refuted using experimental and other means.
Theoretical biology used to primarily provide a basis to rationally examine the
frameworks within which biological experiments were carried out and to shed
light on overlooked gaps in understanding. Today, however, theoretical biology
has generally become synonymous with computational and mathematical biology.
This could in part be explained by a relatively recent tendency in which a
"data first", rather than a "theory first", approach is preferred. Moreover,
generating hypotheses has at times become procedural rather than theoretical.
This situation leaves our understanding enmeshed in data, which should be
disentangled from much noise. Given the many unresolved questions in biology
and medicine, it seems apt to revive the role of pure theory in the biological
sciences. This paper makes the case for a "philosophical biology"
(philbiology), distinct from but quite complementary to philosophy of biology
(philobiology), which would entail biological investigation through
philosophical approaches. Philbiology would thus be a reincarnation of
theoretical biology, adopting the true sense of the word "theory" and making
use of a rich tradition of serious philosophical approaches in the natural
sciences. A philbiological investigation, after clearly defining a given
biological problem, would aim to propose a set of empirical questions, along
with a class of possible solutions, about that problem. Importantly, whether or
not the questions can be tested using current experimental paradigms would be
secondary to whether the questions are inherently empirical or not. The final
goal of a philbiological investigation would be to develop a theoretical
framework that can lead observational and/or interventional experimental
studies of the defined problem.


title: Crystallization in two dimensions and a discrete Gauss-Bonnet theorem

abstract:
  We show that the emerging field of discrete differential geometry can be
usefully brought to bear on crystallization problems. In particular, we give a
simplified proof of the Heitmann-Radin crystallization theorem (R. C. Heitmann,
C. Radin, J. Stat. Phys. 22, 281-287, 1980), which concerns a system of $N$
identical atoms in two dimensions interacting via the idealized pair potential
$V(r)=+\infty$ if $r<1$, $-1$ if $r=1$, $0$ if $r>1$. This is done by endowing
the bond graph of a general particle configuration with a suitable notion of
{\it discrete curvature}, and appealing to a {\it discrete Gauss-Bonnet
theorem} (O. Knill, Elem. Math. 67, 1-17, 2012) which, as its continuous
cousins, relates the sum/integral of the curvature to topological invariants.
This leads to an exact geometric decomposition of the Heitmann-Radin energy
into (i) a combinatorial bulk term, (ii) a combinatorial perimeter, (iii) a
multiple of the Euler characteristic, and (iv) a natural topological energy
contribution due to defects. An analogous exact geometric decomposition is also
established for soft potentials such as the Lennard-Jones potential
$V(r)=r^{-6}-2r^{-12}$, where two additional contributions arise, (v) elastic
energy and (vi) energy due to non-bonded interactions.


title: Special cases of the planar least gradient problem

abstract:
  We study two special cases of the planar least gradient problem. In the first
one, the boundary conditions are imposed on a part of the strictly convex
domain. In the second case, we impose the Dirichlet data on the boundary of a
rectangle, an example of convex but not strictly convex domain. We show the
existence of solutions and study their properties for particular cases of data.


title: BCFW-type recurrent relations for tree amplitudes of D=11 supergravity

abstract:
  We propose the on-shell superfield description for tree amplitudes of D=11
supergravity and the BCFW (Britto-Cachazo-Feng-Witten)-type recurrent relations
for these superamplitudes.


title: Exo-Higgs at 750 GeV and Genesis of Baryons

abstract:
  We propose that the diphoton excess at 750 GeV reported by ATLAS and CMS is
due to the decay of an ${\it exo-Higgs}$ scalar $\eta$ associated with the
breaking of a new $SU(2)_e$ symmetry, dubbed ${\it exo-spin}$. New fermions,
${\it exo-quarks}$ and ${\it exo-leptons}$, get TeV-scale masses through Yukawa
couplings with $\eta$ and generate its couplings to gluons and photons at
1-loop. The matter content of our model yields a $B-L$ anomaly under $SU(2)_e$,
whose breaking we assume entails a first order phase transition. A non-trivial
$B-L$ asymmetry may therefore be generated in the early universe, potentially
providing a baryogenesis mechanism through the Standard Model (SM) sphaleron
processes. The spontaneous breaking of $SU(2)_e$ can in principle directly lead
to electroweak symmetry breaking, thereby accounting for the proximity of the
mass scales of the SM Higgs and the exo-Higgs. Our model can be distinguished
from those comprising a singlet scalar and vector fermions by the discovery of
TeV scale exo-vector bosons, corresponding to the broken $SU(2)_e$ generators,
at the LHC.


title: Anticommutation in the Presentations of Theta-Deformed Spheres

abstract:
  We consider an analogue of the theta-deformed even spheres, modifying the
relations demanded of the self-adjoint generator x in the usual presentation.
In this analogue, x is given anticommutation relations with all of the other
generators, as opposed to being central. Using even K-theory, we show that
noncommutative Borsuk-Ulam theorems hold for these algebras.


title:
Nonzero-sum stochastic differential games with impulse controls: a
  verification theorem with applications

abstract:
  We consider a general nonzero-sum impulse game with two players. The main
mathematical contribution of the paper is a verification theorem which
provides, under some regularity conditions, a suitable system of
quasi-variational inequalities for the value functions and the optimal
strategies of the two players. As an application, we study an impulse game with
a one-dimensional state variable, following a real-valued scaled Brownian
motion, and two players with linear and symmetric running payoffs. We fully
characterize a Nash equilibrium and provide explicit expressions for the
optimal strategies and the value functions. We also prove some asymptotic
results with respect to the intervention costs. Finally, we consider two
further non-symmetric examples where a Nash equilibrium is found numerically.


title: MWStat: A Modulated Web-Based Statistical System

abstract:
  In this paper we present the development of a modulated web based statistical
system, hereafter MWStat, which shifts the statistical paradigm of analyzing
data into a real time structure. The MWStat system is useful for both online
storage data and questionnaires analysis, as well as to provide real time
disposal of results from analysis related to several statistical methodologies
in a customizable fashion. Overall, it can be seem as a useful technical
solution that can be applied to a large range of statistical applications,
which needs of a scheme of devolution of real time results, accessible to
anyone with internet access. We display here the step-by-step instructions for
implementing the system. The structure is accessible, built with an easily
interpretable language and it can be strategically applied to online
statistical applications. We rely on the relationship of several free
languages, namely, PHP, R, MySQL database and an Apache HTTP server, and on the
use of software tools such as phpMyAdmin. We expose three didactical examples
of the MWStat system on institutional evaluation, statistical quality control
and multivariate analysis. The methodology is also illustrated in a real
example on institutional evaluation.


title:
Friedmann dynamics recovered from compactified Einstein-Gauss-Bonnet
  cosmology

abstract:
  In this paper cosmological dynamics in Einstein-Gauss-Bonnet gravity with a
perfect fluid source in arbitrary dimension is studied. A systematic analysis
is performed for the case that the theory does not admit maximally symmetric
solutions. Considering two independent scale factors, namely one for the three
dimensional space and one for the extra dimensional space, is found that a
regime exists where the two scale factors tend to a constant value via damped
oscillations for not too negative pressure of the fluid, so that asymptotically
the evolution of the $(3+1)$-dimensional Friedmann model with perfect fluid is
recovered. At last, it is worth emphasizing that the present numerical results
strongly support a 't Hooft-like interpretation of the parameter $1/D$ (where
$D$ is the number of extra dimensions) as a small expansion parameter in very
much the same way as it happens in the large $N$ expansion of gauge theories
with $1/N$. Indeed, the dependence on $D$ of many of the relevant physical
quantities computed here manifests a clear WKB-like pattern, as expected on the
basis of large $N$ arguments.


title: Improved Sparse Low-Rank Matrix Estimation

abstract:
  We address the problem of estimating a sparse low-rank matrix from its noisy
observation. We propose an objective function consisting of a data-fidelity
term and two parameterized non-convex penalty functions. Further, we show how
to set the parameters of the non-convex penalty functions, in order to ensure
that the objective function is strictly convex. The proposed objective function
better estimates sparse low-rank matrices than a convex method which utilizes
the sum of the nuclear norm and the $\ell_1$ norm. We derive an algorithm (as
an instance of ADMM) to solve the proposed problem, and guarantee its
convergence provided the scalar augmented Lagrangian parameter is set
appropriately. We demonstrate the proposed method for denoising an audio signal
and an adjacency matrix representing protein interactions in the `Escherichia
coli' bacteria.


title:
Global Existence and Regularity Results for Large Cross Diffusion Models
  on Planar Domains

abstract:
  The global existence of classical solutions to cross diffusion systems of
more than 2 equations given on a planar domain is established. The results can
apply to generalized Shigesada-Kawasaki-Teramoto (SKT) and food pyramid models
whose diffusion and reaction can have polynomial growth of any order.


title:
Stably positive Lyapunov exponents for symplectic linear cocycles over
  partially hyperbolic diffeomorphisms

abstract:
  We consider symplectic cocycles over two classes of partially hyperbolic
diffeomorphisms: having compact center leaves and time one maps of Anosov
flows. We prove that the Lyapunov exponents are non-zero in an open and dense
set in the H\"older topology.


title: Routability in 3D IC Design: Monolithic 3D vs. Skybridge 3D CMOS

abstract:
  Conventional 2D CMOS technology is reaching fundamental scaling limits, and
interconnect bottleneck is dominating integrated circuit (IC) power and
performance. While 3D IC technologies using Through Silicon Via or Monolithic
Inter-layer Via alleviate some of these challenges, they follow a similar
layout and routing mindset as 2D CMOS. This is insufficient to address routing
requirements in high-density 3D ICs and even causes severe routing congestion
at large-scale designs, limiting their benefits and scalability. Skybridge is a
recently proposed fine-grained 3D IC fabric relying on vertical nanowires that
presents a paradigm shift for scaling, while addressing associated 3D
connectivity and manufacturability challenges. Skybridge's core fabric
components enable a new 3D IC design approach with vertically-composed logic
gates, and provide a greater degree of routing flexibility compared to
conventional 2D and 3D ICs leading to much larger benefits and future
scalability. In this paper, we present a methodology using relevant metrics to
evaluate and quantify the benefits of Skybridge vs. state-of-the-art
transistor-level monolithic 3D IC (T-MI) and 2D in terms of routability and its
impact on large-scale circuits. This is enabled by a new device-to-system
design flow with commercial CAD tools that we developed for large-scale
Skybridge IC designs in 16nm node. Evaluation for standard benchmark circuits
shows that Skybridge yields up to 1.6x lower routing demand against T-MI with
no routing congestion (routing demand to resource ratio < 1) at all metal
layers. This 3D routability in conjunction with compact vertical gate design in
Skybridge translate into benefits of up to 3x lower power and 11x higher
density over 2D CMOS, while TLM-3DIC approach only has up to 22% power saving
and 2x density improvement over 2D CMOS.


title:
The Hawaii SCUBA-2 Lensing Cluster Survey: Number Counts and
  Submillimeter Flux Ratios

abstract:
  We present deep number counts at 450 and 850 $\mu$m using the SCUBA-2 camera
on the James Clerk Maxwell Telescope. We combine data for six lensing cluster
fields and three blank fields to measure the counts over a wide flux range at
each wavelength. Thanks to the lensing magnification, our measurements extend
to fluxes fainter than 1 mJy and 0.2 mJy at 450 $\mu$m and 850 $\mu$m,
respectively. Our combined data highly constrain the faint end of the number
counts. Integrating our counts shows that the majority of the extragalactic
background light (EBL) at each wavelength is contributed by faint sources with
$L_{\rm IR} < 10^{12} L_{\odot }$, corresponding to luminous infrared galaxies
(LIRGs) or normal galaxies. By comparing our result with the 500 $\mu$m
stacking of $K$-selected sources from the literature, we conclude that the
$K$-selected LIRGs and normal galaxies still cannot fully account for the EBL
that originates from sources with $L_{\rm IR} < 10^{12} L_{\odot }$. This
suggests that many faint submillimeter galaxies may not be included in the UV
star formation history. We also explore the submillimeter flux ratio between
the two bands for our 450 $\mu$m and 850 $\mu$m selected sources. At 850
$\mu$m, we find a clear relation between the flux ratio and the observed flux.
This relation can be explained by a redshift evolution, where galaxies at
higher redshifts have higher luminosities and star formation rates. In
contrast, at 450 $\mu$m, we do not see a clear relation between the flux ratio
and the observed flux.


title: Induced Forests in Bipartite Planar Graphs

abstract:
  Akiyama and Watanabe conjectured that every simple planar bipartite graph on
$n$ vertices contains an induced forest on at least $5n/8$ vertices. We apply
the discharging method to show that every simple bipartite planar graph on $n$
vertices contains an induced forest on at least $\lceil (4n+3)/7 \rceil$
vertices.


title:
Recommended Thermal Rate Coefficients for the C + H$_3^+$ Reaction and
  Some Astrochemical Implications

abstract:
  We have incorporated our experimentally derived thermal rate coefficients for
C + H$_3^+$ forming CH$^+$ and CH$_2^+$ into a commonly used astrochemical
model. We find that the Arrhenius-Kooij equation typically used in chemical
models does not accurately fit our data and use instead a more versatile
fitting formula. At a temperature of 10 K and a density of 10$^4$ cm$^{-3}$, we
find no significant differences in the predicted chemical abundances, but at
higher temperatures of 50, 100, and 300 K we find up to factor of 2 changes.
Additionally, we find that the relatively small error on our thermal rate
coefficients, $\sim15\%$, significantly reduces the uncertainties on the
predicted abundances compared to those obtained using the currently implemented
Langevin rate coefficient with its estimated factor of 2 uncertainty.


title: Some new perspectives on d-orthogonal polynomials

abstract:
  The aim of this paper is twofold. The first part is concerned with the
associated and the so-called co-polynomials, i.e. new sequences obtained when
finite perturbations of the recurrence coefficients are considered. In the
second part we present nice Casorati determinants with co-polynomials entries.
We look at Darboux factorization of lower Hessenberg matrices and the
corresponding polynomials, then combine it with totally nonnegative matrices to
find out sufficient conditions for zeros to be real and distinct. In addition,
kernel polynomials, d-symmetric sequences as well as quasi-orthogonality from
linear combination are discussed as well. Therefore, new characterization of
the d-quasi-orthogonality which corresponds to the first structure relation in
the standard case is constructed.


title:
DSP Implementation of a Direct Adaptive Feedfoward Control Algorithm for
  Rejecting Repeatable Runout in Hard Disk Drives

abstract:
  A direct adaptive feedforward control method for tracking repeatable runout
(RRO) in bit patterned media recording (BPMR) hard disk drives (HDD) is
proposed. The technique estimates the system parameters and the residual RRO
simultaneously and constructs a feedforward signal based on a known regressor.
An improved version of the proposed algorithm to avoid matrix inversion and
reduce computation complexity is given. Results for both MATLAB simulation and
digital signal processor (DSP) implementation are provided to verify the
effectiveness of the proposed algorithm.


title:
ALMA Science Verification Data: Millimeter Continuum Polarimetry of the
  Bright Radio Quasar 3C 286

abstract:
  We present full-polarization observations of the compact, steep-spectrum
radio quasar 3C~286 made with the ALMA at 1.3~mm. These are the first
full-polarization ALMA observations, which were obtained in the framework of
Science Verification. A bright core and a south-west component are detected in
the total intensity image, similar to previous centimeter images. Polarized
emission is also detected toward both components. The fractional polarization
of the core is about 17\%, this is higher than the fractional polarization at
centimeter wavelengths, suggesting that the magnetic field is even more ordered
in the millimeter radio core than it is further downstream in the jet. The
observed polarization position angle (or EVPA) in the core is
$\sim$\,$39^{\circ}$, which confirms the trend that the EVPA slowly increases
from centimeter to millimeter wavelengths. With the aid of multi-frequency VLBI
observations, we argue that this EVPA change is associated with the
frequency-dependent core position. We also report a serendipitous detection of
a sub-mJy source in the field of view, which is likely to be a submillimeter
galaxy.


title: InterActive: Inter-Layer Activeness Propagation

abstract:
  An increasing number of computer vision tasks can be tackled with deep
features, which are the intermediate outputs of a pre-trained Convolutional
Neural Network. Despite the astonishing performance, deep features extracted
from low-level neurons are still below satisfaction, arguably because they
cannot access the spatial context contained in the higher layers. In this
paper, we present InterActive, a novel algorithm which computes the activeness
of neurons and network connections. Activeness is propagated through a neural
network in a top-down manner, carrying high-level context and improving the
descriptive power of low-level and mid-level neurons. Visualization indicates
that neuron activeness can be interpreted as spatial-weighted neuron responses.
We achieve state-of-the-art classification performance on a wide range of image
datasets.


title:
Origin of Pressure-induced Superconducting Phase in
  K$_{x}$Fe$_{2-y}$Se$_{2}$ studied by Synchrotron X-ray Diffraction and
  Spectroscopy

abstract:
  Pressure dependence of the electronic and crystal structures of
K$_{x}$Fe$_{2-y}$Se$_{2}$, which has pressure-induced two superconducting domes
of SC I and SC II, was investigated by x-ray emission spectroscopy and
diffraction. X-ray diffraction data show that compressibility along the c-axis
changes around 12 GPa, where a new superconducting phase of SC II appears. This
suggests a possible tetragonal to collapsed tetragonal phase transition. X-ray
emission spectroscopy data also shows the change in the electronic structure
around 12 GPa. These results can be explained by the scenario that the two SC
domes under pressure originate from the change of Fermi surface topology.
Present results here show that the nesting condition plays a key role in
stabilizing the superconducting state helping to address outstanding
fundamental question as to why the SC II appears under pressure.


title:
Finsler geometry modeling of phase separation in multi-component
  membranes

abstract:
  Finsler geometric surface model is studied as a coarse-grained model for
membranes of three-component such as DOPC, DPPC and Cholesterol. To understand
the phase separation of liquid ordered (DPPC rich) $L_o$ and the liquid
disordered (DOPC rich) $L_d$, we introduce a variable $\sigma (\in \{1,-1\})$
in the triangulated surface model. We numerically find that there appear two
circulars and stripe domains on the surface and that these two morphologies are
separated by a phase transition. The morphological change from the one to the
other with respect to the variation of the area fraction of $L_o$ is consistent
with existing experimental results. This gives us a clear understanding of the
origin of the line tension energy, which has been used to understand those
morphological changes in the three-component membranes. In addition to these
two circulars and stripe domains, raft-like domain and budding domain are also
observed, and the corresponding several phase diagrams are obtained. Technical
details of the Finsler geometry modeling are also shown.


title: DisturbLabel: Regularizing CNN on the Loss Layer

abstract:
  During a long period of time we are combating over-fitting in the CNN
training process with model regularization, including weight decay, model
averaging, data augmentation, etc. In this paper, we present DisturbLabel, an
extremely simple algorithm which randomly replaces a part of labels as
incorrect values in each iteration. Although it seems weird to intentionally
generate incorrect training labels, we show that DisturbLabel prevents the
network training from over-fitting by implicitly averaging over exponentially
many networks which are trained with different label sets. To the best of our
knowledge, DisturbLabel serves as the first work which adds noises on the loss
layer. Meanwhile, DisturbLabel cooperates well with Dropout to provide
complementary regularization functions. Experiments demonstrate competitive
recognition results on several popular image recognition datasets.


title:
Finsler geometry modeling and Monte Carlo study of 3D liquid crystal
  elastomer

abstract:
  We study a three-dimensional ($3D$) liquid crystal elastomer (LCE) in the
context of Finsler geometry (FG) modeling, where FG is a mathematical framework
for describing anisotropic phenomena. The LCE is a $3D$ rubbery object and has
remarkable properties, such as the so-called soft elasticity and elongation,
the mechanisms of which are unknown at present. To understand these anisotropic
phenomena, we introduce a variable $\sigma$, which represents the directional
degrees of freedom of a liquid crystal (LC) molecule. This variable $\sigma$ is
used to define the Finsler metric for the interaction between the LC molecules
and bulk polymers. Performing Monte Carlo (MC) simulations for a cylindrical
body between two parallel plates, we numerically find the soft elasticity in MC
data such that the tensile stress and strain are consistent with reported
experimental results. Moreover, the elongation is also observed in the results
of MC simulations of a spherical body with free boundaries, and the data
obtained from the MC simulations are also consistent with existing experimental
results.


title:
Distributed Cell Association for Energy Harvesting IoT Devices in Dense
  Small Cell Networks: A Mean-Field Multi-Armed Bandit Approach

abstract:
  The emerging Internet of Things (IoT)-driven ultra-dense small cell networks
(UD-SCNs) will need to combat a variety of challenges. On one hand, massive
number of devices sharing the limited wireless resources will render
centralized control mechanisms infeasible due to the excessive cost of
information acquisition and computations. On the other hand, to reduce energy
consumption from fixed power grid and/or battery, many IoT devices may need to
depend on the energy harvested from the ambient environment (e.g., from RF
transmissions, environmental sources). However, due to the opportunistic nature
of energy harvesting, this will introduce uncertainty in the network operation.
In this article, we study the distributed cell association problem for energy
harvesting IoT devices in UD-SCNs. After reviewing the state-of-the-art
research on the cell association problem in small cell networks, we outline the
major challenges for distributed cell association in IoT-driven UD-SCNs where
the IoT devices will need to perform cell association in a distributed manner
in presence of uncertainty (e.g., limited knowledge on channel/network) and
limited computational capabilities. To this end, we propose an approach based
on mean-field multi-armed bandit games to solve the uplink cell association
problem for energy harvesting IoT devices in a UD-SCN. This approach is
particularly suitable to analyze large multi-agent systems under uncertainty
and lack of information. We provide some theoretical results as well as
preliminary performance evaluation results for the proposed approach.


title: Strongly Refuting Random CSPs Below the Spectral Threshold

abstract:
  Random constraint satisfaction problems (CSPs) are known to exhibit threshold
phenomena: given a uniformly random instance of a CSP with $n$ variables and
$m$ clauses, there is a value of $m = \Omega(n)$ beyond which the CSP will be
unsatisfiable with high probability. Strong refutation is the problem of
certifying that no variable assignment satisfies more than a constant fraction
of clauses; this is the natural algorithmic problem in the unsatisfiable regime
(when $m/n = \omega(1)$).
  Intuitively, strong refutation should become easier as the clause density
$m/n$ grows, because the contradictions introduced by the random clauses become
more locally apparent. For CSPs such as $k$-SAT and $k$-XOR, there is a
long-standing gap between the clause density at which efficient strong
refutation algorithms are known, $m/n \ge \widetilde O(n^{k/2-1})$, and the
clause density at which instances become unsatisfiable with high probability,
$m/n = \omega (1)$.
  In this paper, we give spectral and sum-of-squares algorithms for strongly
refuting random $k$-XOR instances with clause density $m/n \ge \widetilde
O(n^{(k/2-1)(1-\delta)})$ in time $\exp(\widetilde O(n^{\delta}))$ or in
$\widetilde O(n^{\delta})$ rounds of the sum-of-squares hierarchy, for any
$\delta \in [0,1)$ and any integer $k \ge 3$. Our algorithms provide a smooth
transition between the clause density at which polynomial-time algorithms are
known at $\delta = 0$, and brute-force refutation at the satisfiability
threshold when $\delta = 1$. We also leverage our $k$-XOR results to obtain
strong refutation algorithms for SAT (or any other Boolean CSP) at similar
clause densities. Our algorithms match the known sum-of-squares lower bounds
due to Grigoriev and Schonebeck, up to logarithmic factors.
  Additionally, we extend our techniques to give new results for certifying
upper bounds on the injective tensor norm of random tensors.


title: Resonant algebras and gravity

abstract:
  The $S$-expansion framework is analyzed in the context of a freedom in
closing the multiplication tables for the abelian semigroups. Including the
possibility of the zero element in the resonant decomposition and associating
the Lorentz generator with the semigroup identity element leads to the wide
class of the expanded Lie algebras introducing interesting modifications to the
gauge gravity theories. Among the results, we find all the Maxwell algebras of
type $\mathfrak{B}_m$, $\mathfrak{C}_m$, and recently introduced
$\mathfrak{D}_m$. The additional new examples complete resulting generalization
of the bosonic enlargements to an arbitrary number of the Lorentz-like and
translational-like generators. Some further prospects concerning enlarging the
algebras are discussed, along with providing all the necessary constituents for
constructing the gravity actions based on the obtained results.


title: Relationship Queries on Large graphs using Pregel

abstract:
  Large-scale graph-structured data arising from social networks, databases,
knowledge bases, web graphs, etc. is now available for analysis and mining.
Graph-mining often involves 'relationship queries', which seek a ranked list of
interesting interconnections among a given set of entities, corresponding to
nodes in the graph. While relationship queries have been studied for many
years, using various terminologies, e.g., keyword-search, Steiner-tree in a
graph etc., the solutions proposed in the literature so far have not focused on
scaling relationship queries to large graphs having billions of nodes and
edges, such are now publicly available in the form of 'linked-open-data'. In
this paper, we present an algorithm for distributed keyword search (DKS) on
large graphs, based on the graph-parallel computing paradigm Pregel. We also
present an analytical proof that our algorithm produces an optimally ranked
list of answers if run to completion. Even if terminated early, our algorithm
produces approximate answers along with bounds. We describe an optimized
implementation of our DKS algorithm along with time-complexity analysis.
Finally, we report and analyze experiments using an implementation of DKS on
Giraph the graph-parallel computing framework based on Pregel, and demonstrate
that we can efficiently process relationship queries on large-scale subsets of
linked-open-data.


title: EW scale DM models with dark gauge symmetries

abstract:
  In this talk, I describe a class of electroweak (EW) scale dark matter (DM)
models where its stability or longevity are the results of underlying dark
gauge symmetries: stable due to unbroken local dark gauge symmetry or topology,
or long-lived due to the accidental global symmetry of dark gauge theories.
Compared with the usual phenomenological dark matter models (including DM EFT
or simplified DM models), DM models with local dark gauge symmetries include
dark gauge bosons, dark Higgs bosons and sometimes excited dark matter. And
dynamics among these fields are completely fixed by local gauge principle. The
idea of singlet portals including the Higgs portal can thermalize these hidden
sector dark matter very efficiently, so that these DM could be easily thermal
DM. I also discuss the limitation of the usual DM effective field theory or
simplified DM models without the full SM gauge symmetry, and emphasize the
importance of the full SM gauge symmetry and renormalizability especially for
collider searches for DM.


title:
Generalization of the tensor renormalization group approach to 3-D or
  higher dimensions

abstract:
  In this paper, a way of generalizing the tensor renormalization group(TRG) is
proposed. Mathematically, the connection between patterns of tensor
renormalization group and the concept of truncation sequence in polytope
geometry is discovered. A theoretical contraction framework is therefore
proposed. Furthermore, the canonical polyadic decomposition is introduced to
tensor network theory. A lowest order numerical verification of this method on
the 3-D Ising model is carried out.


title:
Long Range Correlation in Higgs Boson Plus Two Jets Production at the
  LHC

abstract:
  We study Higgs boson plus two high energy jets production at the LHC in the
kinematics where the two jets are well separated in rapidity. The partonic
processes are dominated by the t-channel weak boson fusion (WBF) and gluon
fusion (GF) contributions. We derive the associated QCD resummation formalism
for the correlation analysis where the total transverse momentum q_\perp of the
Higgs boson and two jets is small. Because of different color structures, the
resummation results lead to distinguished behaviors: the WBF contribution peaks
at relative low q_\perp while all GF channel contributions are strongly
de-correlated and spread to a much wider q_\perp range. By applying a kinematic
cut on q_\perp, one can effectively increase the WBF signal to the GF
background by a significant factor. This greatly strengthens the ability to
investigate the WBF channel in Higgs boson production and study the couplings
of Higgs to electroweak bosons.


title: Higher Order Recurrent Neural Networks

abstract:
  In this paper, we study novel neural network structures to better model long
term dependency in sequential data. We propose to use more memory units to keep
track of more preceding states in recurrent neural networks (RNNs), which are
all recurrently fed to the hidden layers as feedback through different weighted
paths. By extending the popular recurrent structure in RNNs, we provide the
models with better short-term memory mechanism to learn long term dependency in
sequences. Analogous to digital filters in signal processing, we call these
structures as higher order RNNs (HORNNs). Similar to RNNs, HORNNs can also be
learned using the back-propagation through time method. HORNNs are generally
applicable to a variety of sequence modelling tasks. In this work, we have
examined HORNNs for the language modeling task using two popular data sets,
namely the Penn Treebank (PTB) and English text8 data sets. Experimental
results have shown that the proposed HORNNs yield the state-of-the-art
performance on both data sets, significantly outperforming the regular RNNs as
well as the popular LSTMs.


title: Improved Algorithms for the Evacuation Route Planning Problem

abstract:
  Emergency evacuation is the process of movement of people away from the
threat or actual occurrence of hazards such as natural disasters, terrorist
attacks, fires and bombs. In this paper, we focus on evacuation from a
building, but the ideas can be applied to city and region evacuation. We define
the problem and show how it can be modeled using graphs. The resulting
optimization problem can be formulated as an integer linear program. Though
this can be solved exactly, this approach does not scale well for graphs with
thousands of nodes and several hundred thousands of edges. This is impractical
for large graphs.
  We study a special case of this problem, where there is only a single source
and a single sink. For this case, we give an improved algorithm \emph{Single
Source Single Sink Evacuation Route Planner (SSEP)}, whose evacuation time is
always at most that of a famous algorithm \emph{Capacity Constrained Route
Planner (CCRP)}, and whose running time is strictly less than that of CCRP. We
prove this mathematically and give supporting results by extensive experiments.
We also study randomized behavior model of people and give some interesting
results.


title:
Angular Momentum Independence of the Entropy Sum and Entropy Product for
  AdS Rotating Black Holes In All Dimensions

abstract:
  In this paper, we investigate the angular momentum independence of the
entropy sum and product for AdS rotating black holes based on the first law of
thermodynamics and a mathematical lemma related to Vandermonde determinant. The
advantage of this method is that the explicit forms of the spacetime metric,
black hole mass and charge are not needed but the Hawking temperature and
entropy formula on the horizons are necessary for static black holes, while our
calculations require the expressions of metric and angular velocity formula. We
find that the entropy sum is always independent of angular momentum for all
dimensions and the angular momentum-independence of entropy product only holds
for the dimensions $d>4$ with at least one rotation parameter $a_i=0$, while
the mass-free of entropy sum and entropy product for rotating black holes only
stand for higher dimensions ($d>4$) and for all dimensions, respectively. On
the other hand, we find that the introduction of a negative cosmological
constant does not affect the angular momentum-free of entropy sum and product
but the criterion for angular momentum-independence of entropy product will be
affected.


title: Basic noise mechanisms of heat-assisted-magnetic recording

abstract:
  Heat-assisted magnetic recording (HAMR) is expected to be a key technology to
significantly increase the areal storage density of magnetic recording devices.
At high temperatures thermally induced noise becomes a major problem, which
must be overcome in order to reliably write magnetic bits with narrow
transitions. We propose an elementary model based on the effective recording
time window (ERTW) to compute the switching probability of bits during HARM of
bit-patterned media. With few assumptions this analytical model allows to gain
deeper insights into the basic noise mechanisms like AC and DC noise. Finally,
we discuss strategies to reduce noise and to increase the areal storage density
of both bit-patterned as well as granular media.


title:
Improved measurement of the absolute branching fraction of
  $D^{+}\rightarrow \bar K^0 \mu^{+}\nu_{\mu}$

abstract:
  By analyzing 2.93 fb$^{-1}$ of data collected at $\sqrt s=3.773$ GeV with the
BESIII detector, we measure the absolute branching fraction ${\mathcal
B}(D^{+}\rightarrow\bar K^0\mu^{+}\nu_{\mu})=(8.72 \pm 0.07_{\rm stat.} \pm
0.18_{\rm sys.})\%$, which is consistent with previous measurements within
uncertainties but with significantly improved precision. Combining the Particle
Data Group values of ${\mathcal B}(D^0\to K^-\mu^+\nu_\mu)$, ${\mathcal
B}(D^{+}\rightarrow\bar K^0 e^{+}\nu_{e})$, and the lifetimes of the $D^0$ and
$D^+$ mesons with the value of ${\mathcal B}(D^{+}\rightarrow\bar K^0
\mu^{+}\nu_{\mu})$ measured in this work, we determine the following ratios of
partial widths: $\Gamma(D^0\to K^-\mu^+\nu_\mu)/\Gamma(D^{+}\rightarrow\bar
K^0\mu^{+}\nu_{\mu})=0.963\pm0.044$ and $\Gamma(D^{+}\rightarrow\bar K^0
\mu^{+}\nu_{\mu})/\Gamma(D^{+}\rightarrow\bar K^0 e^{+}\nu_{e})=0.988\pm0.033$.


title: Community Evolution

abstract:
  The continuous interest in the social network area contributes to the fast
development of this field. The new possibilities of obtaining and storing data
facilitate deeper analysis of the entire social network, extracted social
groups and single individuals as well. One of the most interesting research
topic is the network dynamics and dynamics of social groups in particular, it
means analysis of group evolution over time. It is the natural step forward
after social community extraction. Having communities extracted, appropriate
knowledge and methods for dynamic analysis may be applied in order to identify
changes as well as to predict the future of all or some selected groups.
Furthermore, knowing the most probably change of a given group some additional
steps may be performed in order to change this predicted future according to
specific needs. Such ability would be a powerful tool in the hands of human
resource managers, personnel recruitment, marketing, telecommunication
companies, etc.


title: On the skein polynomial for links

abstract:
  We give characterizations of the skein polynomial for links (as well as Jones
and Alexander-Conway polynomials derivable from it), avoiding the usual
"smoothing of a crossing" move. As by-products we have characterizations of
these polynomials for knots, and for links with any given number of components.


title:
The Homotopy Method Revisited: Computing Solution Paths of
  $\ell_1$-Regularized Problems

abstract:
  $ \ell_1 $-regularized linear inverse problems are frequently used in signal
processing, image analysis, and statistics. The correct choice of the
regularization parameter $ t \in \mathbb{R}_{\geq 0} $ is a delicate issue.
Instead of solving the variational problem for a fixed parameter, the idea of
the homotopy method is to compute a complete solution path $ u(t) $ as a
function of $ t $. In a celebrated paper by Osborne, Presnell, and Turlach, it
has been shown that the computational cost of this approach is often comparable
to the cost of solving the corresponding least squares problem. Their analysis
relies on the one-at-a-time condition, which requires that different indices
enter or leave the support of the solution at distinct regularization
parameters. In this paper, we introduce a generalized homotopy algorithm based
on a nonnegative least squares problem, which does not require such a
condition, and prove its termination after finitely many steps. At every point
of the path, we give a full characterization of all possible directions. To
illustrate our results, we discuss examples in which the standard homotopy
method either fails or becomes infeasible. To the best of our knowledge, our
algorithm is the first to provably compute a full solution path for an
arbitrary combination of an input matrix and a data vector.


title: Short interval results for a class of arithmetic functions

abstract:
  Using estimates on Hooley's $\Delta$-function and a short interval version of
the celebrated Dirichlet hyperbola principle, we derive an asymptotic formula
for a class of arithmetic functions over short segments. Numerous examples are
also given.


title: The group $G_{n}^{2}$ with a parity and with points

abstract:
  In~\cite{Ma} Manturov studied groups $G_{n}^{k}$ for fixed integers $n$ and
$k$ such that $k<n$. In particular, $G_{n}^{2}$ is isomorphic to the group of
free braids of $n$-stands. In~\cite{KiMa} Manturov and the author studied an
invariant valued in free groups not only for free braids but also for free
tangles, which is derived from the group $G_{n}^{2}$. On the other hands,
in~\cite{FeMa} Manturov and Fedoseev studied groups $Br_{2}^{n}$ of virtual
braids with parity and groups $Br_{d}^{n}$ of virtual braids with dots. They
showed that there is a monomorphism from $Br_{2}^{n}$ to $Br_{d}^{n}$ and it is
deduced that a parity of the braid can be represented by a geometric object,
dots on strands. In this paper we study $G_{n}^{2}$ with structures, which are
corresponded to parity and points on a braid, which are denoted by
$G_{n,p}^{2}$ and $G_{n,d}^{2}$, respectively. In section 3, it is proved that
there is a monomorphism from $G_{n}^{2}$ to $G_{n,p}^{2}$ and that there is a
monomorphism from $G_{n,p}^{2}$ to $G_{n,d}^{2}$. By the homomorphism from
$G_{n}^{2}$ to $G_{n,p}^{2}$, it can be deduced that a given parity of a braid
has geometric representation, which is the number of points on the braid. In
section 4, it can be proved that for each element $\beta$ in $G_{n,d}^{2}$, an
element in $G_{n+1}^{2}$ obtained by adding another strand by tracing points on
$\beta$. That is, a parity of free braid of $n$-stands is represented not only
by points on strands, but also by an $n+1$-th strand. Conversely, for a braid
of $n+1$-strands, a braid of $n$-strands is obtained by deleting one strand of
the braid of $n+1$-strand. Finally, we will simply discuss about the way to
adjust the previous observations to know whether a given braid is Brunnian or
not.


title: Markov properties of the magnetic field in the quiet solar photosphere

abstract:
  The observed magnetic field on the solar surface is characterized by a very
complex spatial and temporal behaviour. Although feature-tracking algorithms
have allowed us to deepen our understanding of this behaviour, subjectivity
plays an important role in the identification, tracking of such features. In
this paper we study the temporal stochasticity of the magnetic field on the
solar surface \textit{without} relying neither on the concept of magnetic
feature nor on subjective assumptions about their identification and
interaction. The analysis is applied to observations of the magnetic field of
the quiet solar photosphere carried out with the IMaX instrument on-board the
stratospheric balloon {\sc Sunrise}. We show that the joint probability
distribution functions of the longitudinal ($B_\parallel$) and transverse
($B_\perp$) components of the magnetic field, as well as of the magnetic
pressure ($B^2=B^2_\perp+B^2_\parallel$), verify the necessary and sufficient
condition for the Markov chains. Therefore we establish that the magnetic
field, as seen by IMaX with a resolution of 0.15\arcsec-0.18\arcsec and
$33$~sec cadence, can be considered as a memoryless temporal fluctuating
quantity.


title: Deep Colorization

abstract:
  This paper investigates into the colorization problem which converts a
grayscale image to a colorful version. This is a very difficult problem and
normally requires manual adjustment to achieve artifact-free quality. For
instance, it normally requires human-labelled color scribbles on the grayscale
target image or a careful selection of colorful reference images (e.g.,
capturing the same scene in the grayscale target image). Unlike the previous
methods, this paper aims at a high-quality fully-automatic colorization method.
With the assumption of a perfect patch matching technique, the use of an
extremely large-scale reference database (that contains sufficient color
images) is the most reliable solution to the colorization problem. However,
patch matching noise will increase with respect to the size of the reference
database in practice. Inspired by the recent success in deep learning
techniques which provide amazing modeling of large-scale data, this paper
re-formulates the colorization problem so that deep learning techniques can be
directly employed. To ensure artifact-free quality, a joint bilateral filtering
based post-processing step is proposed. We further develop an adaptive image
clustering technique to incorporate the global image information. Numerous
experiments demonstrate that our method outperforms the state-of-art algorithms
both in terms of quality and speed.


title: Asynchronous Optimization Over Heterogeneous Networks via Consensus ADMM

abstract:
  This paper considers the distributed optimization of a sum of locally
observable, non-convex functions. The optimization is performed over a
multi-agent networked system, and each local function depends only on a subset
of the variables. An asynchronous and distributed alternating directions method
of multipliers (ADMM) method that allows the nodes to defer or skip the
computation and transmission of updates is proposed in the paper. The proposed
algorithm utilizes different approximations in the update step, resulting in
proximal and majorized ADMM variants. Both variants are shown to converge to a
local minimum, under certain regularity conditions. The proposed asynchronous
algorithms are also applied to the problem of cooperative localization in
wireless ad hoc networks, where it is shown to outperform the other
state-of-the-art localization algorithms.


title:
On the large $\Omega$-deformations in the Nekrasov-Shatashvili limit of
  $\mathcal N=2^{*}$ SYM

abstract:
  We study the multi-instanton partition functions of the $\Omega$-deformed
$\mathcal N =2^{*}$ $SU(2) $ gauge theory in the Nekrasov-Shatashvili (NS)
limit. They depend on the deformation parameters $\epsilon_{1}$, the scalar
field expectation value $a$, and the hypermultiplet mass $m$. At fixed
instanton number $k$, they are rational functions of $\epsilon_{1}, a, m$ and
we look for possible regularities that admit a parametrical description in the
number of instantons. In each instanton sector, the contribution to the
deformed Nekrasov prepotential has poles for "large" deformation parameters. To
clarify the properties of these singularities we exploit Bethe/gauge
correspondence and examine the special ratios $m/\epsilon_{1}$ at which the
associated spectral problem is $n$-gap. At these special points we illustrate
several structural simplifications occurring in the partition functions. After
discussing various tools to compute the prepotential, we analyze the
non-perturbative corrections up to $k=24$ instantons and present various closed
expressions for the coefficients of the singular terms. Both the regular and
singular parts of the prepotential are resummed over all instantons and
compared successfully with the exact prediction from the spectral theory of the
Lam\'e equation, showing that the pole singularities are an artifact of the
instanton expansion. The analysis is fully worked out in the 1-gap case, but
the final pole cancellation is proved for a generic ratio $m/\epsilon_{1}$
relating it to the gap width of the Lam\'e equation.


title:
Characteristic box dimension of unit-time map near nilpotent singularity
  of planar vector field and applications

abstract:
  This article shows how box dimension of the unit-time map can be used in
studying the multiplicity of nilpotent singularities of planar vector fields.
Using unit-time map on the characteristic curve of nilpotent singularity we
define characteristic map and characteristic box dimension of the unit-time
map. We study connection between the box dimension of discrete orbits generated
by the unit-time map of planar vector fields on the characteristic or invariant
curves, and the multiplicity of singularities. Nilpotent singularities which
are studied are nilpotent node, focus and cusp. Also, we show how box dimension
of the Poincar\' e map near the nilpotent focus on the characteristic curve
reveals the upper bound for cyclicity. Moreover, we study the characteristic
box dimension of nilpotent cusp at infinity which is connected to the order of
cusp. At the end, we applied the results of box dimension of unit-time map to
the Bogdanov-Takens bifurcation.