title:
A diagrammer's note on DC conductivity of anisotropic Fermi liquids for
  beginners: Maebashi-Fukuyama formula and Taylor formula

abstract:
  Formal but exact DC conductivity formulae for anisotropic Fermi liquids are
reviewed. One is the Maebashi-Fukuyama formula based on the Fermi-surface
harmonics. The other is the Taylor formula based on the scattering
eigenfunction. In comparison to these two formulae the
current-vertex-correction in the fluctuation-exchange approximation is shown to
be a bad vision caused by an inconsistent approximation.


title: The source structure of 0642+449 detected from the CONT14 observations

abstract:
  The CONT14 campaign with state-of-the-art VLBI data has observed the source
0642+449 with about one thousand observables each day during a continuous
observing period of fifteen days, providing tens of thousands of closure
delays---the sum of the delays around a closed loop of baselines. The closure
delay is independent of the instrumental and propagation delays and provides
valuable additional information about the source structure. We demonstrate the
use of this new "observable" for the determination of the structure in the
radio source 0642+449. This source, as one of the defining sources in the
second realization of the International Celestial Reference Frame (ICRF2), is
found to have two point-like components with a relative position offset of -426
microarcseconds in right ascension and -66 microarcseconds in declination. The
two components are almost equally bright with a flux-density ratio of 0.92. The
standard deviation of closure delays for source 0642+449 was reduced from 139
ps to 90 ps by using this two-component model. Closure delays larger than one
nanosecond are found to be related to the source structure, demonstrating that
structure effects for a source with this simple structure could be up to tens
of nanoseconds. The method described in this paper does not rely on a priori
source structure information, such as knowledge of source structure determined
from direct (Fourier) imaging of the same observations or observations at other
epochs. We anticipate our study to be a starting point for more effective
determination of the structure effect in VLBI observations.


title:
Properties of strongly magnetized ultradense matter and their imprints
  on magnetar pulsations

abstract:
  We investigate the effect of strong magnetic fields on the adiabatic radial
oscillations of hadronic stars. We describe magnetized hadronic matter within
the framework of the relativistic nonlinear Walecka model and integrate the
equations of relativistic radial oscillations to determine the fundamental
pulsation mode. We consider that the magnetic field increases, in a density
dependent way, from the surface, where it has a typical magnetar value of
$10^{15}$ G, to the interior of the star where it can be as large as $3 \times
10^{18}$ G. We show that magnetic fields of the order of $10^{18}$ G at the
stellar core produce a significant change in the frequency of neutron star
pulsations with respect to unmagnetized objects. If radial pulsations are
excited in magnetar flares, they can leave an imprint in the flare lightcurves
and open a new window for the study of highly magnetized ultradense matter.


title:
Spiral Structure and Differential Dust Size Distribution in the LkHa 330
  Disk

abstract:
  Dust trapping accelerates the coagulation of dust particles, and thus it
represents an initial step toward the formation of planetesimals. We report
$H$-band (1.6 um) linear polarimetric observations and 0.87 mm interferometric
continuum observations toward a transitional disk around LkHa 330. As results,
a pair of spiral arms were detected in the $H$-band emission and an asymmetric
(potentially arm-like) structure was detected in the 0.87 mm continuum
emission. We discuss the origin of the spiral arm and the asymmetric structure,
and suggest that a massive unseen planet is the most plausible explanation. The
possibility of dust trapping and grain growth causing the asymmetric structure
was also investigated through the opacity index (beta) by plotting the observed
SED slope between 0.87 mm from our SMA observation and 1.3 mm from literature.
The results imply that grains are indistinguishable from ISM-like dust in the
east side ($beta = 2.0 pm 0.5$), but much smaller in the west side $beta =
0.7^{+0.5}_{-0.4}$, indicating differential dust size distribution between the
two sides of the disk. Combining the results of near-infrared and submillimeter
observations, we conjecture that the spiral arms exist at the upper surface and
an asymmetric structure resides in the disk interior. Future observations at
centimeter wavelengths and differential polarization imaging in other bands (Y
to K) with extreme AO imagers are required to understand how large dust grains
form and to further explore the dust distribution in the disk.


title:
The vanishing discount problem and viscosity Mather measures. Part 2:
  boundary value problems

abstract:
  In arXiv:1603.01051 (Part 1 of this series), we have introduced a variational
approach to studying the vanishing discount problem for fully nonlinear,
degenerate elliptic, partial differential equations in a torus. We develop this
approach further here to handle boundary value problems. In particular, we
establish new representation formulas for solutions of discount problems,
critical values, and use them to prove convergence results for the vanishing
discount problems.


title: A Descending Price Auction for Matching Markets

abstract:
  This work presents a descending-price-auction algorithm to obtain the maximum
market-clearing price vector (MCP) in unit-demand matching markets with m items
by exploiting the combinatorial structure. With a shrewd choice of goods for
which the prices are reduced in each step, the algorithm only uses the
combinatorial structure, which avoids solving LPs and enjoys a strongly
polynomial runtime of $O(m^4)$. Critical to the algorithm is determining the
set of under-demanded goods for which we reduce the prices simultaneously in
each step of the algorithm. This we accomplish by choosing the subset of goods
that maximize a skewness function, which makes the bipartite graph series
converges to the combinatorial structure at the maximum MCP in $O(m^2)$ steps.
A graph coloring algorithm is proposed to find the set of goods with the
maximal skewness value that yields $O(m^4)$ complexity.


title:
Scanning tunneling spectroscopy as a probe of multi-Q magnetic states of
  itinerant magnets

abstract:
  The combination of electronic correlations and Fermi surfaces with multiple
nesting vectors can lead to the appearance of complex multi-Q magnetic ground
states, hosting unusual states such as chiral density-waves and quantum Hall
insulators. Distinguishing single-Q and multi-Q magnetic phases is however a
notoriously difficult experimental problem. Here we propose theoretically that
the local density of states near a magnetic impurity, whose orientation may be
controlled by an external magnetic field, can be used to map out the detailed
magnetic configuration of an itinerant system and distinguish unambiguously
between single-Q and multi-Q phases. We demonstrate this concept by computing
and contrasting the LDOS near a magnetic impurity embedded in three different
magnetic ground states relevant to iron-based superconductors -- one single-Q
and two double-Q phases. Our results open a promising avenue to investigate
complex magnetic configurations in itinerant systems via standard scanning
tunneling spectroscopy, without requiring spin-resolved capability.


title:
Application of the Allan Variance to Time Series Analysis in Astrometry
  and Geodesy: A Review

abstract:
  The Allan variance (AVAR) was introduced 50 years ago as a statistical tool
for assessing of the frequency standards deviations. For the past decades, AVAR
has increasingly being used in geodesy and astrometry to assess the noise
characteristics in geodetic and astrometric time series. A specific feature of
astrometric and geodetic measurements, as compared with the clock measurements,
is that they are generally associated with uncertainties; thus, an appropriate
weighting should be applied during data analysis. Besides, some physically
connected scalar time series naturally form series of multi-dimensional
vectors. For example, three station coordinates time series $X$, $Y$, and $Z$
can be combined to analyze 3D station position variations. The classical AVAR
is not intended for processing unevenly weighted and/or multi-dimensional data.
Therefore, AVAR modifications, namely weighted AVAR (WAVAR), multi-dimensional
AVAR (MAVAR), and weighted multi-dimensional AVAR (WMAVAR), were introduced to
overcome these deficiencies. In this paper, a brief review is given of the
experience of using AVAR and its modifications in processing astro-geodetic
time series.


title:
Instability of Charged Gauss-Bonnet Black Hole in de Sitter Spacetime at
  Large $D$

abstract:
  We study the stabilities of (A)dS charged Gauss-Bonnet(GB) black holes in the
large $D$ dimensions. After integrating the equation of motion with respect to
the radial direction, we obtain the effective equations at large $D$ to
describe the nonlinear dynamical deformations of the black hole. From the
perturbation analysis of the effective equations, we get the analytic
expressions of the frequencies for the quasinormal modes of scalar type.
Furthermore we show that the charged GB black hole becomes unstable only if the
cosmological constant is positive, otherwise the black hole is always stable.
At the onset of instabilities there is a non-trivial static zero-mode
perturbation, which suggests the existence of a new non-spherical symmetric
solution branch of static dS charged GB black holes. We construct the
non-spherical symmetric static solution of the large $D$ effective equations
explicitly.


title:
Section Chern number for a 3D photonic crystal and the bulk-edge
  correspondence

abstract:
  We have characterized the robust propagation modes of electromagnetic waves
in helical structures by the section Chern number that is defined for a
two-dimensional (2D) section of the three- dimensional (3D) Brillouin zone. The
Weyl point in the photonic bands is associated with a dis- continuous jump of
the section Chern number. A spatially localized Gaussian basis set is used to
calculate the section Chern numbers where we have implemented the
divergence-free condition on each basis function in 3D. The validity of the
bulk-edge correspondence in a 3D photonic crystal is discussed in relation to
the broken inversion symmetry.


title: Loop super-Virasoro Lie conformal superalgebra

abstract:
  The loop super-Virasoro conformal superalgebra $\mathfrak{cls}$ associated
with the loop super-Virasoro algebra is constructed in the present paper. The
conformal superderivation algebra of $\mathfrak{cls}$ is completely determined,
which is shown to consist of inner superderivations. And nontrivial free and
free $\mathbb{Z}$-graded $\mathfrak{cls}$-modules of rank two are classified.
We also give a classification of irreducible free $\mathfrak{cls}$-modules of
rank two and all irreducible submodules of each free $\mathbb{Z}$-graded
$\mathfrak{cls}$-module of rank two.


title:
Measurement of spin pumping voltage separated from extrinsic microwave
  effects

abstract:
  Conversions between spin and charge currents are core technologies in recent
spintronics. In this article, we provide methods for estimating inverse spin
Hall effects (ISHEs) induced by using microwave-driven spin pumping (SP) as a
spin-current generator. ISHE and SP induce an electromotive force at the
ferromagnetic or spin-wave resonance, which offers a valuable electric way to
study spin physics in materials. At the resonance, a microwave for exciting the
magnetization dynamics induces an additional electromotive force via rf-current
rectification and thermoelectric effects. We discuss methods to separate the
signals generated from such extrinsic microwave effects by controlling sample
structures and configurations. These methods are helpful in performing accurate
measurements on ISHE induced by SP, enabling quantitative studies on the
conversion between spin and charge currents on various kinds of materials.


abstract:
  Irreducibilities of Verma modules over a class of Block type Lie algebras are
completely determined. The approach developed in the present paper can be used
to deal with non-weight modules.


title: A Note on Field Redefinitions and Higher-Spin Equations

abstract:
  In this note we provide some details on the quasi-local field redefinitions
which map interactions extracted from Vasiliev's equations to those obtained
via holographic reconstruction. Without loss of generality, we focus on the
source to the Fronsdal equations induced by current interactions quadratic in
the higher-spin linearised curvatures.


title: On the triharmonic Lane-Emden equation

abstract:
  We derive a monotonicity formula and classify finite Morse index solutions
(positive or sign-changing, radial or not) to the following triharmonic
Lane-Emden equation: \begin{equation}\nonumber (-\Delta)^3 u=|u|^{p-1}u \hbox{
in } \mathbb{R}^n, \end{equation} where $p$ is below the Joseph-Lundgren
exponent. As a byproduct we also obtain a new monotonicity formula for the
triharmonic maps.


title:
Comment on "Supercurrent in a room temperature Bose-Einstein magnon
  condensate"

abstract:
  The comment explains that the preprint arXiv:1503.0042 has not presented
persuasive theoretical or experimental arguments of existence of spin
supercurrents in a magnon condensate prepared in a room temperature
yttrium-iron-garnet magnetic film because the authors did not check known
criteria for existence of spin supercurrents in magnetically ordered materials.
Also they did not compare their supercurrent interpretation with a competing
and more realistic scenario of transport by spin diffusion.


title:
Core spaces, sector spaces and fan spaces: a topological approach to
  domain theory

abstract:
  We present old and new characterizations of core spaces, alias worldwide web
spaces, originally defined by the existence of supercompact neighborhood bases.
The patch spaces of core spaces, obtained by joining the original topology with
a second topology having the dual specialization order, are the so-called
sector spaces, which have good convexity and separation properties and
determine the original space. The category of core spaces is shown to be
concretely isomorphic to the category of fan spaces; these are certain
quasi-ordered spaces having neighborhood bases of so-called fans, obtained by
deleting a finite number of principal filters from a principal filter. This
approach has useful consequences for domain theory. In fact, endowed with the
Scott topology, the continuous domains are nothing but the sober core spaces,
and endowed with the Lawson topology, they are the corresponding fan spaces. We
generalize the characterization of continuous lattices as meet-continuous
lattices with T$_2$ Lawson topology and extend the Fundamental Theorem of
Compact Semilattices to non-complete structures. Finally, we investigate
cardinal invariants like density and weight of the involved objects.


title:
Novel multilevel preconditioners for the systems arising from plane wave
  discretization of Helmholtz equations with large wave numbers

abstract:
  In this paper we are concerned with fast algorithms for the systems arising
from the plane wave discretizations for two-dimensional Helmholtz equations
with large wave numbers. We consider the plane wave weighted least squares
(PWLS) method and the plane wave discontinuous Galerkin (PWDG) method. The main
goal of this paper is to construct multilevel parallel preconditioners for
solving the resulting Helmholtz systems. To this end, we first build a
multilevel overlapping space decomposition for the plane wave discretization
space based on a multilevel overlapping domain decomposition method. Then,
corresponding to the space decomposition, we construct an additive multilevel
preconditioner for the underlying Helmholtz systems. Further, we design both
additive and multiplicative multilevel preconditioners with smoothers, which
are different from the standard multigrid preconditioners. We apply the
proposed multilevel preconditioners with a {\it constant} coarsest mesh size to
solve two dimensional Helmholtz systems generated by PWLS method or PWDG
method, and we find that the new preconditioners possess nearly stable
convergence, i.e., the iteration counts of the preconditioned iterative methods
(PCG or PGMRES) with the preconditioners increase very slowly when the wave
number increases (and the fine mesh size decreases).


title:
Coherent control of optical spin-to-orbital angular momentum conversion
  in metasurface

abstract:
  We propose and experimentally demonstrate that a metasurface consisting of
Pancharatnam-Berry phase optical elements can enable the full control of
optical spin-to-orbital angular momentum conversion. Our approach relies on the
critical interference between the transmission and reflection upon the
metasurfaceto create actively tunable and controllable conversion with a high
output via coherent control of the two incident beams. The introduced control
methodology is general and could be an important step toward the development of
functional optical devices for practical applications.


title:
The metastable minima of the Heisenberg spin glass in a random magnetic
  field

abstract:
  We have studied zero temperature metastable states in classical $m$-vector
component spin glasses in the presence of $m$-component random fields (of
strength $h_{r}$) for a variety of models, including the Sherrington
Kirkpatrick (SK) model, the Viana Bray (VB) model and the randomly diluted
one-dimensional models with long-range power law interactions. For the SK model
we have calculated analytically its complexity (the log of the number of
minima) for both the annealed case and the quenched case, both for fields above
and below the de Almeida Thouless (AT) field ($h_{AT} > 0$ for $m>2$). We have
done quenches starting from a random initial state by putting spins parallel to
their local fields until convergence and found that in zero field it always
produces minima which have zero overlap with each other. For the $m=2$ and
$m=3$ cases in the SK model the final energy reached in the quench is very
close to the energy $E_c$ at which the overlap of the states would acquire
replica symmetry breaking features. These minima have marginal stability and
will have long-range correlations between them. In the SK limit we have
analytically studied the density of states $\rho(\lambda)$ of the Hessian
matrix in the annealed approximation. Despite the absence of continuous
symmetries, the spectrum extends down to zero with the usual $\sqrt{\lambda}$
form for the density of states for $h_{r}<h_{AT}$. However, when
$h_{r}>h_{AT}$, there is a gap in the spectrum which closes up as $h_{AT}$ is
approached. For the VB model and the other models our numerical work shows that
there always exist some low-lying eigenvalues and there never seems to be a
gap. There is no sign of the AT transition in the quenched states reached from
infinite temperature for any model but the SK model, which is the only model
which has zero complexity above $h_{AT}$.


title: Probability of Partially Decoding Network-Coded Messages

abstract:
  In the literature there exists analytical expressions for the probability of
a receiver decoding a transmitted source message that has been encoded using
random linear network coding. In this work, we look into the probability that
the receiver will decode at least a fraction of the source message, and present
an exact solution to this problem for both non-systematic and systematic
network coding. Based on the derived expressions, we investigate the potential
of these two implementations of network coding for information-theoretic secure
communication and progressive recovery of data.


title:
Forward Hadron Productions in Proton-Proton Collisions in Small-$x$
  Formalism

abstract:
  Employing the so-called hybrid formalism, we calculate the cross section of
inclusive hadron production in proton-proton collisions at forward rapidity in
small-$x$ formalism at one-loop order. For the case of hadron production at
forward rapidity, we can uses collinear parton distributions for projectile
proton and $k_\perp$ dependent gluon distribution for target proton. We show
that collinear divergences associated with initial and final state parton
radiations are renormalized into parton distributions and fragmentation
functions in terms of the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution
equation, respectively. Furthermore, rapidity divergence can be absorbed into
the wave function of target proton which gives rise to the well-known
Balitsky-Fadin-Kuraev-Lipatov equation. These divergences are completely
separated from the short distance partonic hard parts, which is now finite at
the next-to-leading order accuracy. The result presented in this paper can be
reckoned as a baseline calculation without any non-linear QCD effects in
small-$x$ formalism. As a consistency check, we compare our results with the
previous calculation for non-linear proton-nucleus collisions in the small-$x$
formalism and find complete agreement in the dilute and large $N_c$ limit. In
phenomenology, the direct comparison of the above two separate calculations can
reveal the role and strength of the non-linear dynamics in high energy QCD, and
thus help us reliably study the onset of gluon saturation when genuine
non-linear interactions become important.


title:
On Chebyshev type Inequalities using Generalized k-Fractional Integral
  Operator

abstract:
  In this paper, using generalized k-fractional integral operator (in terms of
the Gauss hypergeometric function), we establish new results on generalized
k-fractional integral inequalities by considering the extended Chebyshev
functional in case of synchronous function and some other inequalities.


title: Cost and dimension of words of zero topological entropy

abstract:
  Let $A^*$ denote the free monoid generated by a finite nonempty set $A.$ In
this paper we introduce a new measure of complexity of languages $L\subseteq
A^*$ defined in terms of the semigroup structure on $A^*.$ For each $L\subseteq
A^*,$ we define its {\it cost} $c(L)$ as the infimum of all real numbers
$\alpha$ for which there exist a language $S\subseteq A^*$ with
$p_S(n)=O(n^\alpha)$ and a positive integer $k$ with $L\subseteq S^k.$ We also
define the {\it cost dimension} $d_c(L)$ as the infimum of the set of all
positive integers $k$ such that $L\subseteq S^k$ for some language $S$ with
$p_S(n)=O(n^{c(L)}).$ We are primarily interested in languages $L$ given by the
set of factors of an infinite word $x=x_0x_1x_2\cdots \in A^\omega$ of zero
topological entropy, in which case $c(L)<+\infty.$ We establish the following
characterisation of words of linear factor complexity: Let $x\in A^\omega$ and
$L=$Fac$(x)$ be the set of factors of $x.$ Then $p_x(n)=\Theta(n)$ if and only
$c(L)=0$ and $d_c(L)=2.$ In other words, $p_x(n)=O(n)$ if and only if
Fac$(x)\subseteq S^2$ for some language $S\subseteq A^+$ of bounded complexity
(meaning $\limsup p_S(n)<+\infty).$ In general the cost of a language $L$
reflects deeply the underlying combinatorial structure induced by the semigroup
structure on $A^*.$ For example, in contrast to the above characterisation of
languages generated by words of sub-linear complexity, there exist non
factorial languages $L$ of complexity $p_L(n)=O(\log n)$ (and hence of cost
equal to $0)$ and of cost dimension $+\infty.$ In this paper we investigate the
cost and cost dimension of languages defined by infinite words of zero
topological entropy.


title: Embedding LTE-U within Wi-Fi Bands for Spectrum Efficiency Improvement

abstract:
  Driven by growing spectrum shortage, Long-term Evolution in unlicensed
spectrum (LTE-U) has recently been proposed as a new paradigm to deliver better
performance and experience for mobile users by extending the LTE protocol to
unlicensed spectrum. In the paper, we first present a comprehensive overview of
the LTE-U technology, and discuss the practical challenges it faces. We
summarize the existing LTE-U operation modes and analyze several means for
LTE-U coexistence with Wi-Fi medium access control protocols. We further
propose a novel hyper access-point (HAP) that integrates the functionalities of
LTE small cell base station and commercial Wi-Fi AP for deployment by cellular
network operators. Our proposed LTE-U access embedding within the Wi-Fi
protocol is non-disruptive to unlicensed Wi-Fi nodes and demonstrates
performance benefits as a seamless and novel LTE and Wi-Fi coexistence
technology in unlicensed band. We provide results to demonstrate the
performances advantage of this novel LTE-U proposal.


title: Spatio-Temporal Saliency Networks for Dynamic Saliency Prediction

abstract:
  Computational saliency models for still images have gained significant
popularity in recent years. Saliency prediction from videos, on the other hand,
has received relatively little interest from the community. Motivated by this,
in this work, we study the use of deep learning for dynamic saliency prediction
and propose the so-called spatio-temporal saliency networks. The key to our
models is the architecture of two-stream networks where we investigate
different fusion mechanisms to integrate spatial and temporal information. We
evaluate our models on the DIEM and UCF-Sports datasets and present highly
competitive results against the existing state-of-the-art models. We also carry
out some experiments on a number of still images from the MIT300 dataset by
exploiting the optical flow maps predicted from these images. Our results show
that considering inherent motion information in this way can be helpful for
static saliency estimation.


title: Weakly supervised object detection using pseudo-strong labels

abstract:
  Object detection is an import task of computer vision.A variety of methods
have been proposed,but methods using the weak labels still do not have a
satisfactory result.In this paper,we propose a new framework that using the
weakly supervised method's output as the pseudo-strong labels to train a
strongly supervised model.One weakly supervised method is treated as black-box
to generate class-specific bounding boxes on train dataset.A de-noise method is
then applied to the noisy bounding boxes.Then the de-noised pseudo-strong
labels are used to train a strongly object detection network.The whole
framework is still weakly supervised because the entire process only uses the
image-level labels.The experiment results on PASCAL VOC 2007 prove the validity
of our framework, and we get result 43.4% on mean average precision compared to
39.5% of the previous best result and 34.5% of the initial
method,respectively.And this frame work is simple and distinct,and is promising
to be applied to other method easily.


title: Difference Index of Quasi-Prime Difference Algebraic Systems

abstract:
  This paper is devoted to studying difference indices of quasi-prime
difference algebraic systems. We define the quasi dimension polynomial of a
quasi-prime difference algebraic system. Based on this, we give the definition
of the difference index of a quasi-prime difference algebraic system through a
family of pseudo-Jacobian matrices. Some properties of difference indices are
proved. In particular, an upper bound of difference indices is given. As
applications, an upper bound of the Hilbert-Levin regularity and an upper bound
of orders for difference ideal membership problem are deduced.


title: Stirrers and movers actuated by oscillating fields

abstract:
  Locomotion via cyclic moves presents a challenge to mesoscopic objects in
overdamped environments, where time reversibility may prevent directed motion.
Most reported cyclic movers exploit anisotropic drag to push themselves
forward. Under an oscillating drive, however, anisotropic drag enables
locomotion only if the objects can change their shape. Here, we present a
strategy that unexpectedly enables structurally invariant objects to move under
oscillating fields. The objects are self-assembled clusters of magnetic
particles that exhibit an off-centered dipole moment. By theoretical modeling
and in experiments with magnetic Janus particles, we demonstrate that the
interaction between such anisotropic particles in the cluster breaks time
reversibility. Experimentally, we show that the magnetic configuration of a
cluster determines its motion path. We realize stirrers and steerable movers
with helical or directed path using the same particle system. The presented
strategy based on internal interactions establishes a counterpart to locomotion
via anisotropic drag.


title: Interaction patterns and diversity in assembled ecological communities

abstract:
  The assembly of ecological communities from a pool of species is central to
ecology, but the effect of this process on properties of community interaction
networks is still largely unknown. Here, we use a systematic analytical
framework to describe how assembly from a species pool gives rise to community
network properties that differ from those of the pool: Compared to the pool,
the community shows a bias towards higher carrying capacities, weaker
competitive interactions and stronger beneficial interactions. Moreover, even
if interactions between all pool species are completely random, community
networks are more structured, with correlations between interspecies
interactions, and between interactions and carrying capacities. Nonetheless, we
show that these properties are not sufficient to explain the coexistence of all
community species, and that it is a simple relation between interactions and
species abundances that is responsible for the diversity within a community.


title:
Stochastic Recursive Inclusions with Non-Additive Iterate-Dependent
  Markov Noise

abstract:
  In this paper we study the asymptotic behavior of stochastic approximation
schemes with set-valued drift function and non-additive iterate-dependent
Markov noise. We show that a linearly interpolated trajectory of such a
recursion is an asymptotic pseudotrajectory for the flow of a limiting
differential inclusion obtained by averaging the set-valued drift function of
the recursion w.r.t. the stationary distributions of the Markov noise. The
limit set theorem in [1] is then used to characterize the limit sets of the
recursion in terms of the dynamics of the limiting differential inclusion. We
then state two variants of the Markov noise assumption under which the analysis
of the recursion is similar to the one presented in this paper. Scenarios where
our recursion naturally appears are presented as applications. These include
controlled stochastic approximation, subgradient descent, approximate drift
problem and analysis of discontinuous dynamics all in the presence of
non-additive iterate-dependent Markov noise.


title: Tail dependence of the Gaussian copula revisited

abstract:
  Tail dependence refers to clustering of extreme events. In the context of
financial risk management, the clustering of high-severity risks has a
devastating effect on the well-being of firms and is thus of pivotal importance
in risk analysis.When it comes to quantifying the extent of tail dependence, it
is generally agreed that measures of tail dependence must be independent of the
marginal distributions of the risks but rather solely copula-dependent. Indeed,
all classical measures of tail dependence are such, but they investigate the
amount of tail dependence along the main diagonal of copulas, which has often
little in common with the concentration of extremes in the copulas' domain of
definition.In this paper we urge that the classical measures of tail dependence
may underestimate the level of tail dependence in copulas. For the Gaussian
copula, however, we prove that the classical measures are maximal. The
implication of the result is two-fold: On the one hand, it means that in the
Gaussian case, the (weak) measures of tail dependence that have been reported
and used are of utmost prudence, which must be a reassuring news for
practitioners. On the other hand, it further encourages substitution of the
Gaussian copula with other copulas that are more tail dependent.


title:
A form of multivariate Pareto distribution with applications to
  financial risk measurement

abstract:
  A new multivariate distribution possessing arbitrarily parametrized and
positively dependent univariate Pareto margins is introduced. Unlike the
probability law of Asimit et al. (2010) [Asimit, V., Furman, E. and Vernic, R.
(2010) On a multivariate Pareto distribution. Insurance: Mathematics and
Economics 46(2), 308-316], the structure in this paper is absolutely continuous
with respect to the corresponding Lebesgue measure. The distribution is of
importance to actuaries through its connections to the popular frailty models,
as well as because of the capacity to describe dependent heavy-tailed risks.
The genesis of the new distribution is linked to a number of existing
probability models, and useful characteristic results are proved. Expressions
for, e.g., the decumulative distribution and probability density functions,
(joint) moments and regressions are developed. The distributions of minima and
maxima, as well as, some weighted risk measures are employed to exemplify
possible applications of the distribution in insurance.


title: Towards a Common Format for Computational Material Science Data

abstract:
  Information and data exchange is an important aspect of scientific progress.
In computational materials science, a prerequisite for smooth data exchange is
standardization, which means using agreed conventions for, e.g., units, zero
base lines, and file formats. There are two main strategies to achieve this
goal. One accepts the heterogeneous nature of the community which comprises
scientists from physics, chemistry, bio-physics, and materials science, by
complying with the diverse ecosystem of computer codes and thus develops
"converters" for the input and output files of all important codes. These
converters then translate the data of all important codes into a standardized,
code-independent format. The other strategy is to provide standardized open
libraries that code developers can adopt for shaping their inputs, outputs, and
restart files, directly into the same code-independent format. We like to
emphasize in this paper that these two strategies can and should be regarded as
complementary, if not even synergetic. The main concepts and software
developments of both strategies are very much identical, and, obviously, both
approaches should give the same final result. In this paper, we present the
appropriate format and conventions that were agreed upon by two teams, the
Electronic Structure Library (ESL) of CECAM and the NOMAD (NOvel MAterials
Discovery) Laboratory, a European Centre of Excellence (CoE). This discussion
includes also the definition of hierarchical metadata describing
state-of-the-art electronic-structure calculations.


title: Multiple risk factor dependence structures: Distributional properties

abstract:
  We introduce a class of dependence structures, that we call the Multiple Risk
Factor (MRF) dependence structures. On the one hand, the new constructions
extend the popular CreditRisk+ approach, and as such they formally describe
default risk portfolios exposed to an arbitrary number of fatal risk factors
with conditionally exponential and dependent hitting (or occurrence) times. On
the other hand, the MRF structures can be seen as an encompassing family of
multivariate probability distributions with univariate margins distributed
Pareto of the 2nd kind, and in this role they can be used to model insurance
risk portfolios of dependent and heavy tailed risk components.


title: Cascaded forward Brillouin scattering to all Stokes orders

abstract:
  Inelastic scattering processes such as Brillouin scattering can often
function in cascaded regimes and this is likely to occur in certain integrated
opto-acoustic devices. We develop a Hamiltonian formalism for cascaded
Brillouin scattering valid for both quantum and classical regimes. By regarding
Brillouin scattering as the interaction of a single acoustic envelope and a
single optical envelope that covers all Stokes and anti-Stokes orders, we
obtain a compact model that is well suited for numerical implementation,
extension to include other optical nonlinearities or short pulses, and
application in the quantum-optics domain. We then theoretically analyze
intra-mode forward Brillouin scattering (FBS) for arbitrary waveguides with and
without optical dispersion. In the absence of optical dispersion, we find an
exact analytical solution. With a perturbative approach, we furthermore solve
the case of weak optical dispersion. Our work leads to several key results on
intra-mode FBS. For negligible dispersion, we show that cascaded intra-mode FBS
results in a pure phase modulation and discuss how this necessitates specific
experimental methods for the observation of fibre-based and integrated FBS.
Further, we discuss how the descriptions that have been established in these
two classes of waveguides connect to each other and to the broader context of
cavity opto-mechanics and Raman scattering. Finally, we draw an unexpected
striking similarity between FBS and discrete diffraction phenomena in waveguide
arrays, which makes FBS an interesting candidate for future research in
quantum-optics.


title: Flag Algebras: A First Glance

abstract:
  The theory of flag algebras, introduced by Razborov in 2007, has opened the
way to a systematic approach to the development of computer-assisted proofs in
extremal combinatorics. It makes it possible to derive bounds for parameters in
extremal combinatorics with the help of a computer, in a semi-automated manner.
This article describes the main points of the theory in a complete way, using
Mantel's theorem as a guiding example.


title:
Special values of Gauss's hypergeometric series derived from Appell's
  series $F_1$ with closed forms

abstract:
  In a previous work ([Eb]), the author proposed a method employing contiguity
relations to derive hypergeometric series in closed form. In [Eb], this method
was used to derive Gauss's hypergeometric series $_2F_1$ possessing closed
forms. Here, we consider the application of this method to Appell's
hypergeometetric series $F_1$ and derive several $F_1$ possessing closed forms.
Moreover, analyzing these $F_1$, we obtain values of $_2F_1$ with no free
parameters. Some of these results provide new examples of algebraic values of
$_2F_1$.
  Key Words and Phrases: Gauss's hypergeometric series, algebraic value,
Appell's hypergeometric series, hypergeometric identity.


title:
Electronic properties of SnTe-class topological crystalline insulator
  materials

abstract:
  The rise of topological insulators in recent years has broken new ground both
in the conceptual cognition of condensed matter physics and the promising
revolution of the electronic devices. It also stimulates the explorations of
more topological states of matter. Topological crystalline insulator is a new
topological phase, which combines the electronic topology and crystal symmetry
together. In this article, we review the recent progress in the studies of
SnTe-class topological crystalline insulator materials. Starting from the
topological identifications in the aspects of the bulk topology, surface states
calculations and experimental observations, we present the electronic
properties of topological crystalline insulators under various perturbations,
including native defect, chemical doping, strain, and thickness-dependent
confinement effects, and then discuss their unique quantum transport
properties, such as valley-selective filtering and helicity-resolved
functionalities for Dirac fermions. The rich properties and high tunability
make SnTe-class materials promising candidates for novel quantum devices.


title:
Note on the representation of the gap formation probability for real and
  quaternion Wishart matrices

abstract:
  Wishart random matrices are often used to model multivariate systems in
physics, finance, biology and wireless communication. Extreme value statistics,
such as those of the smallest eigenvalue, can be used to test the accuracy of
the model. In this article we study the gap formation probability (cumulative
distribution function of the smallest eigenvalue) for real and quaternion
$N\times \left(N+\nu\right)$ Wishart random matrices in the large $N$ limit. We
derive compact expression in terms of determinants of known functions. As a
consequence of this representation, the gap formation probabilities solve the
Toda lattice equation, in the index $\nu$ for $\nu$ even and for $\nu$ odd
separately.


title:
A Posteriori Error Analysis for the Optimal Control of Magneto-Static
  Fields

abstract:
  This paper is concerned with the analysis and numerical analysis for the
optimal control of first-order magneto-static equations. Necessary and
sufficient optimality conditions are established through a rigorous Hilbert
space approach. Then, on the basis of the optimality system, we prove
functional a posteriori error estimators for the optimal control, the optimal
state, and the adjoint state. 3D numerical results illustrating the theoretical
findings are presented.


title:
Accurate semilocal density functional for condensed matter physics and
  quantum chemistry

abstract:
  Most density functionals have been developed by imposing the known exact
constraints on the exchange-correlation energy, or by a fit to a set of
properties of selected systems, or by both. However, accurate modeling of the
conventional exchange hole presents a great challenge, due to the
delocalization of the hole. Making use of the property that the hole can be
made localized under a general coordinate transformation, here we derive an
exchange hole from the density matrix expansion, while the correlation part is
obtained by imposing the low-density limit constraint. From the hole, a
semilocal exchange-correlation functional is calculated. Our comprehensive test
shows that this functional can achieve remarkable accuracy for diverse
properties of molecules, solids and solid surfaces, substantially improving
upon the nonempirical functionals proposed in recent years. Accurate semilocal
functionals based on their associated holes are physically appealing and
practically useful for developing nonlocal functionals.


title:
Learning Social Circles in Ego Networks based on Multi-View Social
  Graphs

abstract:
  In social network analysis, automatic social circle detection in ego-networks
is becoming a fundamental and important task, with many potential applications
such as user privacy protection or interest group recommendation. So far, most
studies have focused on addressing two questions, namely, how to detect
overlapping circles and how to detect circles using a combination of network
structure and network node attributes. This paper asks an orthogonal research
question, that is, how to detect circles based on network structures that are
(usually) described by multiple views? Our investigation begins with crawling
ego-networks from Twitter and employing classic techniques to model their
structures by six views, including user relationships, user interactions and
user content. We then apply both standard and our modified multi-view spectral
clustering techniques to detect social circles in these ego-networks. Based on
extensive automatic and manual experimental evaluations, we deliver two major
findings: first, multi-view clustering techniques perform better than common
single-view clustering techniques, which only use one view or naively integrate
all views for detection, second, the standard multi-view clustering technique
is less robust than our modified technique, which selectively transfers
information across views based on an assumption that sparse network structures
are (potentially) incomplete. In particular, the second finding makes us
believe a direct application of standard clustering on potentially incomplete
networks may yield biased results. We lightly examine this issue in theory,
where we derive an upper bound for such bias by integrating theories of
spectral clustering and matrix perturbation, and discuss how it may be affected
by several network characteristics.


title:
Canonical dual method for mixed integer fourth-order polynomial
  minimization problems with fixed cost terms

abstract:
  We study a canonical duality method to solve a mixed-integer nonconvex
fourth-order polynomial minimization problem with fixed cost terms. This
constrained nonconvex problem can be transformed into a continuous concave
maximization dual problem without duality gap. The global optimality conditions
are proposed and the existence and uniqueness criteria are discussed.
Application to a decoupled mixed-integer problem is illustrated and analytic
solution for a global minimum is obtained under some suitable conditions.
Several examples are given to show the method is effective.


title:
Lifetimes and wave functions of ozone metastable vibrational states near
  the dissociation limit in full symmetry approach

abstract:
  Energies and lifetimes (widths) of vibrational states above the lowest
dissociation limit of $^{16}$O$_3$ were determined using a previously-developed
efficient approach, which combines hyperspherical coordinates and a complex
absorbing potential. The calculations are based on a recently-computed
potential energy surface of ozone determined with a spectroscopic accuracy [J.
Chem. Phys. {\bf 139}, 134307 (2013)]. The effect of permutational symmetry on
rovibrational dynamics and the density of resonance states in O$_3$ is
discussed in detail. Correspondence between quantum numbers appropriate for
short- and long-range parts of wave functions of the rovibrational continuum is
established. It is shown, by symmetry arguments, that the allowed purely
vibrational ($J=0$) levels of $^{16}$O$_3$ and $^{18}$O$_3$, both made of
bosons with zero nuclear spin, cannot dissociate on the ground state potential
energy surface. Energies and wave functions of bound states of the ozone
isotopologue $^{16}$O$_3$ with rotational angular momentum $J=0$ and 1 up to
the dissociation threshold were also computed. For bound levels, good agreement
with experimental energies is found: The RMS deviation between observed and
calculated vibrational energies is 1~\cm. Rotational constants were determined
and used for a simple identification of vibrational modes of calculated levels.


title: Remarks on Automorphy of Residually Dihedral Representations

abstract:
  We prove automorphy lifting results for geometric representations $\rho:G_F
\rightarrow GL_2(\mathcal{O})$, with $F$ a totally real field, and
$\mathcal{O}$ the ring of integers of a finite extension of $\mathbb{Q}_p$ with
$p$ an odd prime, such that the residual representation $\bar{\rho}$ is totally
odd and induced from a character of the absolute Galois group of the quadratic
subfield $K$ of $F(\zeta_p)/F$. Such representations fail the Taylor-Wiles
hypothesis and the patching techniques to prove automorphy do not work. We
apply this to automorphy of elliptic curves $E$ over $F$, when $E$ has no $F$
rational 7-isogeny and such that the image of $G_F$ acting on $E[7]$ normalizes
a split Cartan subgroup of $GL_2(\mathbb{F}_7)$.


title:
Fast Simulation of Hyperplane-Truncated Multivariate Normal
  Distributions

abstract:
  We introduce a fast and easy-to-implement simulation algorithm for a
multivariate normal distribution truncated on the intersection of a set of
hyperplanes, and further generalize it to efficiently simulate random variables
from a multivariate normal distribution whose covariance (precision) matrix can
be decomposed as a positive-definite matrix minus (plus) a low-rank symmetric
matrix. Example results illustrate the correctness and efficiency of the
proposed simulation algorithms.


title:
Finite-time and finite-size scalings in the evaluation of
  large-deviation functions: Analytical study using a birth-death process

abstract:
  The Giardin\`a-Kurchan-Peliti algorithm is a numerical procedure that uses
population dynamics in order to calculate large deviation functions associated
to the distribution of time-averaged observables. To study the numerical errors
of this algorithm, we explicitly devise a stochastic birth-death process that
describes the time evolution of the population probability. From this
formulation, we derive that systematic errors of the algorithm decrease
proportionally to the inverse of the population size. Based on this
observation, we propose a simple interpolation technique for the better
estimation of large deviation functions. The approach we present is detailed
explicitly in a two-state model.


title: How Much Do Downlink Pilots Improve Cell-Free Massive MIMO?

abstract:
  In this paper, we analyze the benefits of including downlink pilots in a
cell-free massive MIMO system. We derive an approximate per-user achievable
downlink rate for conjugate beamforming processing, which takes into account
both uplink and downlink channel estimation errors, and power control. A
performance comparison is carried out, in terms of per-user net throughput,
considering cell-free massive MIMO operation with and without downlink
training, for different network densities. We take also into account the
performance improvement provided by max-min fairness power control in the
downlink. Numerical results show that, exploiting downlink pilots, the
performance can be considerably improved in low density networks over the
conventional scheme where the users rely on statistical channel knowledge only.
In high density networks, performance improvements are moderate.


title:
Joint Optimization of Coverage, Capacity and Load Balancing in
  Self-Organizing Networks

abstract:
  This paper develops an optimization framework for self-organizing networks
(SON). The objective is to ensure efficient network operation by a joint
optimization of different SON functionalities, which includes capacity,
coverage and load balancing. Based on the axiomatic framework of monotone and
strictly subhomogeneous function, we formulate an optimization problem for the
uplink and propose a two-step optimization scheme using fixed point iterations:
i) per base station antenna tilt optimization and power allocation, and ii)
cluster-based base station assignment of users and power allocation. We then
consider the downlink, which is more difficult to handle due to coupled
variables, and show downlink-uplink duality relationship. As a result, a
solution for the downlink is obtained by solving the uplink problem.
Simulations show that our approach achieves a good trade-off between coverage,
capacity and load balancing.


title: High-dimensional approximate $r$-nets

abstract:
  The construction of $r$-nets offers a powerful tool in computational and
metric geometry. We focus on high-dimensional spaces and present a new
randomized algorithm which efficiently computes approximate $r$-nets with
respect to Euclidean distance. For any fixed $\epsilon>0$, the approximation
factor is $1+\epsilon$ and the complexity is polynomial in the dimension and
subquadratic in the number of points. The algorithm succeeds with high
probability. More specifically, the best previously known LSH-based
construction of Eppstein et al.\ \cite{EHS15} is improved in terms of
complexity by reducing the dependence on $\epsilon$, provided that $\epsilon$
is sufficiently small. Our method does not require LSH but, instead, follows
Valiant's \cite{Val15} approach in designing a sequence of reductions of our
problem to other problems in different spaces, under Euclidean distance or
inner product, for which $r$-nets are computed efficiently and the error can be
controlled. Our result immediately implies efficient solutions to a number of
geometric problems in high dimension, such as finding the
$(1+\epsilon)$-approximate $k$th nearest neighbor distance in time subquadratic
in the size of the input.


title: Hereditarily normal manifolds of dimension > 1 may all be metrizable

abstract:
  P.J. Nyikos has asked whether it is consistent that every hereditarily normal
manifold of dimension > 1 is metrizable, and proved it is if one assumes the
consistency of a supercompact cardinal, and, in addition, that the manifold is
hereditarily collectionwise Hausdorff. We are able to omit these extra
assumptions.


title: ADD-OPT: Accelerated Distributed Directed Optimization

abstract:
  In this paper, we consider distributed optimization problems where the goal
is to minimize a sum of objective functions over a multi-agent network. We
focus on the case when the inter-agent communication is described by a
strongly-connected, \emph{directed} graph. The proposed algorithm, ADD-OPT
(Accelerated Distributed Directed Optimization), achieves the best known
convergence rate for this class of problems,~$O(\mu^{k}),0<\mu<1$, given
strongly-convex, objective functions with globally Lipschitz-continuous
gradients, where~$k$ is the number of iterations. Moreover, ADD-OPT supports a
wider and more realistic range of step-sizes in contrast to existing work. In
particular, we show that ADD-OPT converges for arbitrarily small (positive)
step-sizes. Simulations further illustrate our results.


title: Projective configuration theorems: old wine into new wineskins

abstract:
  This is a survey of select recent results by a number of authors, inspired by
the classical configuration theorems of projective geometry.


title:
New version of Gram-Schmidt Process with inverse for Signal and Image
  Processing

abstract:
  The Gram-Schmidt Process (GSP) is used to convert a non-orthogonal basis (a
set of linearly independent vectors, matrices, etc) into an orthonormal basis
(a set of orthogonal, unit-length vectors, bi or tri dimensional matrices). The
process consists of taking each array and then subtracting the projections in
common with the previous arrays. This paper introduces an enhanced version of
the Gram-Schmidt Process (EGSP) with inverse, which is useful for Digital
Signal and Image Processing, among others applications.


title:
Design and implementation of image processing system for Lumen social
  robot-humanoid as an exhibition guide for Electrical Engineering Days 2015

abstract:
  Lumen Social Robot is a humanoid robot development with the purpose that it
could be a good friend to all people. In this year, the Lumen Social Robot is
being developed into a guide in the exhibition and in the seminar of the Final
Exam of undergraduate and graduate students in Electrical Engineering ITB,
named Electrical Engineering Days 2015. In order to be the guide in that
occasion, Lumen is supported by several things. They are Nao robot components,
servers, and multiple processor systems. The image processing system is a
processing application system that allows Lumen to recognize and determine an
object from the image taken from the camera eye. The image processing system is
provided with four modules. They are face detection module to detect a person's
face, face recognition module to recognize a person's face, face tracking
module to follow a person's face, and human detection module to detect humans
based on the upper parts of person's body. Face detection module and human
detection module are implemented by using the library harcascade.xml on EMGU
CV. Face recognition module is implemented by adding the database for the face
that has been detected and store it in that database. Face tracking module is
implemented by using the Smooth Gaussian filter to the image.
  -----
  Lumen Sosial Robot merupakan sebuah pengembangan robot humanoid agar dapat
menjadi teman bagi banyak orang. Sistem pengolahan citra merupakan sistem
aplikasi pengolah yang bertujuan Lumen dapat mengenali dan mengetahui suatu
objek pada citra yang diambil dari camera mata Lumen. System pengolahan citra
dilengkapi dengan empat buah modul, yaitu modul face detection untuk mendeteksi
wajah seseorang, modul face recognition untuk mengenali wajah orang tersebut,
modul face tracking untuk mengikuti wajah seseorang, dan modul human detection
untuk mendeteksi manusia berdasarkan bagian tubuh atas orang


title:
Non-monotonic temperature dependence of chaos-assisted diffusion in
  driven periodic systems

abstract:
  The spreading of a cloud of independent Brownian particles typically proceeds
more effectively at higher temperatures, as it derives from the commonly known
Sutherland-Einstein relation for systems in thermal equilibrium. Here, we
report on a non-equilibrium situation in which the diffusion of a periodically
driven Brownian particle moving in a periodic potential decreases with
increasing temperature within a finite temperature window. We identify as the
cause for this non-intuitive behaviour a dominant deterministic mechanism
consisting of a few unstable periodic orbits embedded into a chaotic attractor
together with thermal noise-induced dynamical changes upon varying temperature.
The presented analysis is based on extensive numerical simulations of the
corresponding Langevin equation describing the studied setup as well as on a
simplified stochastic model formulated in terms of a three-state Markovian
process. Because chaos exists in many natural as well as in artificial systems
representing abundant areas of contemporary knowledge, the described mechanism
may potentially be discovered in plentiful different contexts.


title:
Quantum Entanglement as a Diagnostic of Phase Transitions in Disordered
  Fractional Quantum Hall Liquids

abstract:
  We investigate the disorder-driven phase transition from a fractional quantum
Hall state to an Anderson insulator using quantum entanglement methods. We find
that the transition is signaled by a sharp increase in the sensitivity of a
suitably averaged entanglement entropy with respect to disorder -- the
magnitude of its disorder derivative appears to diverge in the thermodynamic
limit. We also study the level statistics of the entanglement spectrum as a
function of disorder. However, unlike the dramatic phase-transition signal in
the entanglement entropy derivative, we find a gradual reduction of level
repulsion only deep in the Anderson insulating phase.


title:
Design and implementation of computational platform for social-humanoid
  robot Lumen as an exhibition guide in Electrical Engineering Days 2015

abstract:
  Social Robot Lumen is an Artificial Intelligence development project that
aims to create an Artificial Intelligence (AI) which allows a humanoid robot to
communicate with human being naturally. In this study, Lumen will be developed
to be a tour guide in Electrical Engineering Days 2015 exhibition. In
developing an AI, there are a lot of modules that need to be developed
separately. To make the development easier, we need a computational platform
which becomes basis for all developers to give easiness in developing the
modules in parallel way. That computational platform that developed by the
writer is called Lumen Server. Lumen Server has two main function, which are to
be a bridge between all Lumen intelligence modules with NAO robot, and to be
the communication bridge between those Lumen intelligence modules. For the
second function, Lumen Server implements the AMQP protocol using RabbitMQ.
Besides that, writer also developed a control system for robot movement called
Lumen Motion. Lumen motion is implemented by modelling the movement of NAO
robot and also by creating a control system using fuzzy logic controller.
Writer also developed a program that connects all Lumen intelligence modules so
that Lumen can act like a tour guide. The implementation of this program uses
FSM and event-driven program. From implementation result, all the features
which were designed are successfully implemented. By the developing of this
computational platform, it can ease the development of Lumen in the future. For
next development, it must be focused on creating integration system so that
Lumen can be more responsive to the environment.
  -----
  Sosial Robot Lumen adalah proyek pengembangan kecerdasan buatan yang
bertujuan untuk menciptakan kecerdasan buatan atau artificial intelligence (AI)
yang memungkinkan robot untuk dapat berkomunikasi dengan manusia secara alami.


title:
On the representations of a positive integer by certain classes of
  quadratic forms in eight variables

abstract:
  In this paper we use the theory of modular forms to find formulas for the
number of representations of a positive integer by certain class of quadratic
forms in eight variables, viz., forms of the form $a_1x_1^2 + a_2 x_2^2 + a_3
x_3^2 + a_4 x_4^2 + b_1(x_5^2+x_5x_6 + x_6^2) + b_2(x_7^2+x_7x_8 + x_8^2)$,
where $a_1\le a_2\le a_3\le a_4$, $b_1\le b_2$ and $a_i$'s $\in \{1,2,3\}$,
$b_i$'s $\in \{1,2,4\}$. We also determine formulas for the number of
representations of a positive integer by the quadratic forms
$(x_1^2+x_1x_2+x_2^2) + c_1(x_3^2+x_3x_4+x_4^2) + c_2(x_5^2+x_5x_6+x_6^2) +
c_3(x_7^2+x_7x_8+x_8^2)$, where $c_1,c_2,c_3\in \{1,2,4,8\}$, $c_1\le c_2\le
c_3$.


title:
Design and implementation of audio communication system for
  social-humanoid robot Lumen as an exhibition guide in Electrical Engineering
  Days 2015

abstract:
  Social Robot Lumen is a humanoid robot created to act like human and be human
friend. In this study, Lumen scenario is limited on Lumen as an exhibition
guide in Electrical Engineering Days 2015, a seminar and exhibition of
electrical engineering undergraduate and graduate student of Bandung Institute
of Technology. To be an exhibition guide, Lumen is equipped by Nao robot, a
server, and processing applications. Audio communication system is one of the
processing applications. The purpose of the system is to create verbal
communication that allow Lumen to receive human voice and respond naturally to
it. To be able to communicate like a human, audio communication system is built
with speech recognition module to transform speech data into text, speech
synthesizer module to transform text data into speech, and gender
identification module to distinguish adult female and male voice. Speech
recognition module is implemented using Google Speech Recognition API, speech
synthesizer module is implemented using Acapela engine, and gender
identification module implemented by utilizing speech signal feature that is
extracted using Fast Fourier Transform algorithm. Hardware used for
implementation are Nao robot, computer, and wireless modem.
  -----
  Lumen Robot Sosial Robot merupakan robot humanoid yang diciptakan agar dapat
bersikap seperti manusia dan menjadi teman bagi manusia. Sistem komunikasi
audio merupakan salah satu aplikasi pengolah yang bertujuan agar Lumen dapat
menerima suara manusia dan meresponnya dengan natural, yaitu seperti cara
manusia merespon manusia lainnya. Untuk dapat berkomunikasi seperti manusia,
sistem komunikasi audio dilengkapi dengan tiga buah modul: speech recognition
untuk mengubah data suara menjadi teks, speech synthesizer untuk mengubah data
teks menjadi suara, dan gender identification untuk membedakan suara wanita dan
pria.


title: Centers of mass of Poncelet polygons, 200 years after

abstract:
  The locus of the centers of mass of the family of Poncelet polygons,
inscribed into a conic $\Gamma$ and circumscribed about a conic $\gamma$, is a
conic homothetic to $\Gamma$.


title:
Optimized Automatic Code Generation for Geometric Algebra Based
  Algorithms with Ray Tracing Application

abstract:
  Automatic code generation for low-dimensional geometric algorithms is capable
of producing efficient low-level software code through a high-level geometric
domain specific language. Geometric Algebra (GA) is one of the most suitable
algebraic systems for being the base for such code generator. This work
presents an attempt at realizing such idea in practice. A novel GA-based
geometric code generator, called GMac, is proposed. Comparisons to similar
GA-based code generators are provided. The possibility of fully benefiting from
the symbolic power of GA while obtaining good performance and maintainability
of software implementations is illustrated through a ray tracing application.


title: Hoffmann-Ostenhof's conjecture for traceable cubic graphs

abstract:
  It was conjectured by Hoffmann-Ostenhof that the edge set of every connected
cubic graph can be decomposed into a spanning tree, a matching and a family of
cycles. In this paper, we show that this conjecture holds for traceable cubic
graphs.


title: Effective equidistribution of horocycle lifts

abstract:
  We give a rate of equidistribution of lifts of horocycles from the space
$\mathrm{SL}(2,\mathbb Z)\backslash \mathrm{SL}(2, \mathbb R)$ to the space
$\mathrm{ASL}(2,\mathbb Z)\backslash \mathrm{ASL}(2,\mathbb R)$, making
effective a theorem of Elkies and McMullen. This result constitutes an
effective version of Ratner's measure classification theorem for measures
supported on general horocycle lifts. The method used relies on Weil's
resolution of the Riemann hypothesis for function fields in one variable and
generalizes the approach of Str\"ombergsson to the case of linear lifts and
that of Browning and the author to rational quadratic lifts.


title:
Shesop Healthcare: Stress and influenza classification using support
  vector machine kernel

abstract:
  Shesop is an integrated system to make human lives more easily and to help
people in terms of healthcare. Stress and influenza classification is a part of
Shesop's application for a healthcare devices such as smartwatch, polar and
fitbit. The main objective of this paper is to classify a new data and inform
whether you are stress, depressed, caught by influenza or not. We will use the
heart rate data taken for months in Bandung, analyze the data and find the
Heart rate variance that constantly related with the stress and flu level.
After we found the variable, we will use the variable as an input to the
support vector machine learning. We will use the lagrangian and kernel
technique to transform 2D data into 3D data so we can use the linear
classification in 3D space. In the end, we could use the machine learning's
result to classify new data and get the final result immediately: stress or
not, influenza or not.


title:
Shesop Healthcare: Android application to monitor heart rate variance,
  display influenza and stress condition using Polar H7

abstract:
  Shesop is an integrated system to make human lives more easily and to help
people in terms of healthcare. Stress and influenza classification is a part of
Shesop's application for a healthcare devices such as smartwatch, polar and
fitbit. The main objective of this paper is to create a proper application to
implement the stress and influenza classification. The application use Android
studio, XML and Java. Also, while creating this application, all design and
program is considered to be available for future updates. The application needs
an android smartphone with Bluetooth Low Energy technology (bluetooth v4.0 or
above). SheSop application will accommodate data entry, device picker, data
gathering process, result and saving the result. In the end, we could use the
polar H7 and this application to get a real-time heart rate, Heart rate
variability and diagnose our stress and influenza condition.


title: The Approachability Ideal Without a Maximal Set

abstract:
  We develop a forcing poset with finite conditions which adds a partial square
sequence on a given stationary set, with adequate sets of models as side
conditions. We then develop a kind of side condition product forcing for
simultaneously adding partial square sequences on multiple stationary sets. We
show that certain quotients of such forcings have the $\omega_1$-approximation
property. We apply these ideas to prove, assuming the consistency of a greatly
Mahlo cardinal, that it is consistent that the approachability ideal
$I[\omega_2]$ does not have a maximal set modulo clubs.


title:
Construction of extended 3D field of views of the internal bladder wall
  surface: a proof of concept

abstract:
  3D extended field of views (FOVs) of the internal bladder wall facilitate
lesion diagnosis, patient follow-up and treatment traceability. In this paper,
we propose a 3D image mosaicing algorithm guided by 2D cystoscopic video-image
registration for obtaining textured FOV mosaics. In this feasibility study, the
registration makes use of data from a 3D cystoscope prototype providing, in
addition to each small FOV image, some 3D points located on the surface. This
proof of concept shows that textured surfaces can be constructed with minimally
modified cystoscopes. The potential of the method is demonstrated on numerical
and real phantoms reproducing various surface shapes. Pig and human bladder
textures are superimposed on phantoms with known shape and dimensions. These
data allow for quantitative assessment of the 3D mosaicing algorithm based on
the registration of images simulating bladder textures.


title: Perfect Single-Sided Radiation and Absorption without Mirrors

abstract:
  Highly directional radiation from photonic structures is important for many
applications, including high power photonic crystal surface emitting lasers,
grating couplers, and light detection and ranging devices. However, previous
dielectric, few-layer designs only achieved moderate asymmetry ratios, and a
fundamental understanding of bounds on asymmetric radiation from arbitrary
structures is still lacking. Here, we show that breaking the 180$^\circ$
rotational symmetry of the structure is crucial for achieving highly asymmetric
radiation. We develop a general temporal coupled-mode theory formalism to
derive bounds on the asymmetric decay rates to the top and bottom of a photonic
crystal slab for a resonance with arbitrary in-plane wavevector. Guided by this
formalism, we show that infinite asymmetry is still achievable even without the
need of back-reflection mirrors, and we provide numerical examples of designs
that achieve asymmetry ratios exceeding $10^4$. The emission direction can also
be rapidly switched from top to bottom by tuning the wavevector or frequency.
Furthermore, we show that with the addition of weak material absorption loss,
such structures can be used to achieve perfect absorption with single-sided
illumination, even for single-pass absorption rates less than $0.5\%$ and
without back-reflection mirrors. Our work provides new design principles for
achieving highly directional radiation and perfect absorption in photonics.


title: The Security of Organizations and Individuals in Online Social Networks

abstract:
  The serious privacy and security problems related to online social networks
(OSNs) are what fueled two complementary studies as part of this thesis. In the
first study, we developed a general algorithm for the mining of data of
targeted organizations by using Facebook (currently the most popular OSN) and
socialbots. By friending employees in a targeted organization, our active
socialbots were able to find new employees and informal organizational links
that we could not find by crawling with passive socialbots. We evaluated our
method on the Facebook OSN and were able to reconstruct the social networks of
employees in three distinct, actual organizations. Furthermore, in the crawling
process with our active socialbots we discovered up to 13.55% more employees
and 22.27% more informal organizational links in contrast to the crawling
process that was performed by passive socialbots with no company associations
as friends.
  In our second study, we developed a general algorithm for reaching specific
OSN users who declared themselves to be employees of targeted organizations,
using the topologies of organizational social networks and utilizing
socialbots. We evaluated the proposed method on targeted users from three
actual organizations on Facebook, and two actual organizations on the Xing OSN
(another popular OSN platform). Eventually, our socialbots were able to reach
specific users with a success rate of up to 70% on Facebook, and up to 60% on
Xing.


title:
Identification of Successive "Unobservable" Cyber Data Attacks in Power
  Systems Through Matrix Decomposition

abstract:
  This paper presents a new framework of identifying a series of cyber data
attacks on power system synchrophasor measurements. We focus on detecting
"unobservable" cyber data attacks that cannot be detected by any existing
method that purely relies on measurements received at one time instant.
Leveraging the approximate low-rank property of phasor measurement unit (PMU)
data, we formulate the identification problem of successive unobservable cyber
attacks as a matrix decomposition problem of a low-rank matrix plus a
transformed column-sparse matrix. We propose a convex-optimization-based method
and provide its theoretical guarantee in the data identification. Numerical
experiments on actual PMU data from the Central New York power system and
synthetic data are conducted to verify the effectiveness of the proposed
method.


title: The complexity of tropical graph homomorphisms

abstract:
  A tropical graph $(H,c)$ consists of a graph $H$ and a (not necessarily
proper) vertex-colouring $c$ of $H$. Given two tropical graphs $(G,c_1)$ and
$(H,c)$, a homomorphism of $(G,c_1)$ to $(H,c)$ is a standard graph
homomorphism of $G$ to $H$ that also preserves the vertex-colours. We initiate
the study of the computational complexity of tropical graph homomorphism
problems. We consider two settings. First, when the tropical graph $(H,c)$ is
fixed; this is a problem called $(H,c)$-COLOURING. Second, when the colouring
of $H$ is part of the input; the associated decision problem is called
$H$-TROPICAL-COLOURING. Each $(H,c)$-COLOURING problem is a constraint
satisfaction problem (CSP), and we show that a complexity dichotomy for the
class of $(H,c)$-COLOURING problems holds if and only if the Feder-Vardi
Dichotomy Conjecture for CSPs is true. This implies that $(H,c)$-COLOURING
problems form a rich class of decision problems. On the other hand, we were
successful in classifying the complexity of at least certain classes of
$H$-TROPICAL-COLOURING problems.


title: Equations of Riemann surfaces with automorphisms

abstract:
  We present an algorithm for computing equations of canonically embedded
Riemann surfaces with automorphisms. A variant of this algorithm with many
heuristic improvements is used to produce equations of Riemann surfaces $X$
with large automorphism groups (that is, $|\mathrm{Aut}(X)| > 4(g_X-1)$) for
genus $4 \leq g_X \leq 7$. The main tools are the Eichler trace formula for the
character of the action of $\mathrm{Aut}(X)$ on holomorphic differentials,
algorithms for producing matrix generators of a representation of a finite
group with a specified irreducible character, and Gr\"obner basis techniques
for computing flattening stratifications.


title:
Bulk viscosity for pion and nucleon thermal fluctuation in the hadron
  resonance gas model

abstract:
  We have calculated microscopically bulk viscosity of hadronic matter, where
equilibrium thermodynamics for all hadrons in medium are described by Hadron
Resonance Gas (HRG) model. Considering pions and nucleons as abundant medium
constituents, we have calculated their thermal widths, which inversely control
the strength of bulk viscosities for respective components and represent their
in-medium scattering probabilities with other mesonic and baryonic resonances,
present in the medium. Our calculations show that bulk viscosity increases with
both temperature and baryon chemical potential, whereas viscosity to entropy
density ratio decreases with temperature and with baryon chemical potential,
the ratio increases first and then decreases. The decreasing nature of the
ratio with temperature is observed in most of the earlier investigations with
few exceptions. We find that the temperature dependence of bulk viscosity
crucially depends on the structure of the relaxation time. Along the chemical
freeze-out line in nucleus-nucleus collisions with increasing collision energy,
bulk viscosity as well as the bulk viscosity to entropy density ratio
decreases, which also agrees with earlier references. Our results indicate the
picture of a strongly coupled hadronic medium.


title:
Exploiting Multi-modal Curriculum in Noisy Web Data for Large-scale
  Concept Learning

abstract:
  Learning video concept detectors automatically from the big but noisy web
data with no additional manual annotations is a novel but challenging area in
the multimedia and the machine learning community. A considerable amount of
videos on the web are associated with rich but noisy contextual information,
such as the title, which provides weak annotations or labels about the video
content. To leverage the big noisy web labels, this paper proposes a novel
method called WEbly-Labeled Learning (WELL), which is established on the
state-of-the-art machine learning algorithm inspired by the learning process of
human. WELL introduces a number of novel multi-modal approaches to incorporate
meaningful prior knowledge called curriculum from the noisy web videos. To
investigate this problem, we empirically study the curriculum constructed from
the multi-modal features of the videos collected from YouTube and Flickr. The
efficacy and the scalability of WELL have been extensively demonstrated on two
public benchmarks, including the largest multimedia dataset and the largest
manually-labeled video set. The comprehensive experimental results demonstrate
that WELL outperforms state-of-the-art studies by a statically significant
margin on learning concepts from noisy web video data. In addition, the results
also verify that WELL is robust to the level of noisiness in the video data.
Notably, WELL trained on sufficient noisy web labels is able to achieve a
comparable accuracy to supervised learning methods trained on the clean
manually-labeled data.


title: Definable versions of Menger's conjecture

abstract:
  Menger's conjecture that Menger spaces are /sigma-compact is false; it is
true for analytic subspaces of Polish spaces and undecidable for more complex
definable subspaces of Polish spaces. For non-metrizable spaces, analytic
Menger spaces are /sigma-compact, but Menger continuous images of co-analytic
spaces need not be. The general co-analytic case is still open, but many
special cases are undecidable, in particular, Menger topological groups. We
also prove that if there is a Michael space, then productively Lindelof
Cech-complete spaces are /sigma-compact. We also give numerous
characterizations of proper K-Lusin spaces. Our methods include the Axiom of
Co-analytic Determinacy, non-metrizable descriptive set theory, and
Arhangel'skii's work on generalized metric spaces.


title:
Perturbative approach to Dynamical Casimir effect in an interface of
  dielectric mediums

abstract:
  Electromagnetic field quantization in the presence of two semi-infinite
dielectrics with moving interface is investigated in $1+1$-dimensional
space-time. The moving interface is modeled for small displacements and the
field equation is solved perturbatively. Input-output relations and spectral
distribution of emitted photons are obtained and the effect of small
transitions trough the interface discussed.


title:
First Model-Independent Measurement of the Spin Triplet $p\Lambda$
  Scattering Length from Final State Interaction in the $\vec{p}p \rightarrow
  pK^{+}\Lambda$ Reaction

abstract:
  The $\vec{p}p \rightarrow pK^{+}\Lambda$ reaction has been measured with the
COSY-TOF detector at a beam momentum of $2.7\,\mathrm{GeV}/c$. The polarized
proton beam enables the measurement of the beam analyzing power by the
asymmetry of the produced kaon ($A_N^{K}$). This observable allows the
$p\Lambda$ spin triplet scattering length to be extracted for the first time
model independently from the final-state interaction in the reaction. The
obtained value is $a_{t} = (-2.55 ^{+0.72}_{-1.39} {}_{\textrm{stat.}} \pm
0.6_{\textrm{syst.}} \pm 0.3_{\textrm{theo.}})\mathrm{fm}$. This value is
compatible with theoretical predictions and results from model-dependent
analyses.


title:
Optical and ultraviolet spectroscopic analysis of SN 2011fe at late
  times

abstract:
  We present optical spectra of the nearby Type Ia supernova SN 2011fe at 100,
205, 311, 349, and 578 days post-maximum light, as well as an ultraviolet
spectrum obtained with Hubble Space Telescope at 360 days post-maximum light.
We compare these observations with synthetic spectra produced with the
radiative transfer code PHOENIX. The day +100 spectrum can be well fit with
models which neglect collisional and radiative data for forbidden lines.
Curiously, including this data and recomputing the fit yields a quite similar
spectrum, but with different combinations of lines forming some of the stronger
features. At day +205 and later epochs, forbidden lines dominate much of the
optical spectrum formation; however, our results indicate that recombination,
not collisional excitation, is the most influential physical process driving
spectrum formation at these late times. Consequently, our synthetic optical and
UV spectra at all epochs presented here are formed almost exclusively through
recombination-driven fluorescence. Furthermore, our models suggest that the
ultraviolet spectrum even as late as day +360 is optically thick and consists
of permitted lines from several iron-peak species. These results indicate that
the transition to the "nebular" phase in Type Ia supernovae is complex and
highly wavelength-dependent.


title: On the almost eigenvectors of random regular graphs

abstract:
  Let $d\geq 3$ be fixed and $G$ be a large random $d$-regular graph on $n$
vertices. We show that if $n$ is large enough then the entry distribution of
every almost eigenvector $v$ of $G$ (with entry sum 0 and normalized to have
length $\sqrt{n}$) is close to some Gaussian distribution $N(0,\sigma)$ in the
weak topology where $0\leq\sigma\leq 1$. Our theorem holds even in the stronger
sense when many entries are looked at simultaneously in small random
neighborhoods of the graph. Furthermore, we also get the Gaussianity of the
joint distribution of several almost eigenvectors if the corresponding
eigenvalues are close. Our proof uses graph limits and information theory. Our
results have consequences for factor of i.i.d.\ processes on the infinite
regular tree.


title: Phase Transitions of the Multifractal Spectrum

abstract:
  We consider the multifractal analysis of the pointwise dimension for Gibbs
measures on countable Markov shifts. Our paper analyses the set of non-analytic
points or phase transitions of the multifractal spectrum. By Sarig's
thermodynamic formalism for countable Markov shifts and Iommi's expression of
the multifractal spectrum, we apply analyticity arguments on the pressure
function for the countable shift. Finally, we apply our results about the phase
transitions of the multifractal spectrum to the Gauss map.


title: Robust algorithms with polynomial loss for near-unanimity CSPs

abstract:
  An instance of the Constraint Satisfaction Problem (CSP) is given by a family
of constraints on overlapping sets of variables, and the goal is to assign
values from a fixed domain to the variables so that all constraints are
satisfied. In the optimization version, the goal is to maximize the number of
satisfied constraints. An approximation algorithm for CSP is called robust if
it outputs an assignment satisfying a $(1-g(\varepsilon))$-fraction of
constraints on any $(1-\varepsilon)$-satisfiable instance, where the loss
function $g$ is such that $g(\varepsilon)\rightarrow 0$ as
$\varepsilon\rightarrow 0$.
  We study how the robust approximability of CSPs depends on the set of
constraint relations allowed in instances, the so-called constraint language.
All constraint languages admitting a robust polynomial-time algorithm (with
some $g$) have been characterised by Barto and Kozik, with the general bound on
the loss $g$ being doubly exponential, specifically
$g(\varepsilon)=O((\log\log(1/\varepsilon))/\log(1/\varepsilon))$. It is
natural to ask when a better loss can be achieved: in particular, polynomial
loss $g(\varepsilon)=O(\varepsilon^{1/k})$ for some constant $k$. In this
paper, we consider CSPs with a constraint language having a near-unanimity
polymorphism. We give two randomized robust algorithms with polynomial loss for
such CSPs: one works for any near-unanimity polymorphism and the parameter $k$
in the loss depends on the size of the domain and the arity of the relations in
$\Gamma$, while the other works for a special ternary near-unanimity operation
called dual discriminator with $k=2$ for any domain size. In the latter case,
the CSP is a common generalisation of Unique Games with a fixed domain and
2-SAT. In the former case, we use the algebraic approach to the CSP. Both cases
use the standard semidefinite programming relaxation for CSP.


title:
Fast and Bounded Probabilistic Collision Detection in Dynamic
  Environments for High-DOF Trajectory Planning

abstract:
  We present a novel approach to perform probabilistic collision detection
between a high-DOF robot and high-DOF obstacles in dynamic, uncertain
environments. In dynamic environments with a high-DOF robot and moving
obstacles, our approach efficiently computes accurate collision probability
between the robot and obstacles with upper error bounds. Furthermore, we
describe a prediction algorithm for future obstacle position and motion that
accounts for both spatial and temporal uncertainties. We present a trajectory
optimization algorithm for high-DOF robots in dynamic, uncertain environments
based on probabilistic collision detection. We highlight motion planning
performance in challenging scenarios with robot arms operating in environments
with dynamically moving human obstacles.


title: Sieving for closest lattice vectors (with preprocessing)

abstract:
  Lattice-based cryptography has recently emerged as a prime candidate for
efficient and secure post-quantum cryptography. The two main hard problems
underlying its security are the shortest vector problem (SVP) and the closest
vector problem (CVP). Various algorithms have been studied for solving these
problems, and for SVP, lattice sieving currently dominates in terms of the
asymptotic time complexity: one can heuristically solve SVP in time
$2^{0.292d}$ in high dimensions $d$ [BDGL'16]. Although several SVP algorithms
can also be used to solve CVP, it is not clear whether this also holds for
heuristic lattice sieving methods. The best time complexity for CVP is
currently $2^{0.377d}$ [BGJ'14].
  In this paper we revisit sieving algorithms for solving SVP, and study how
these algorithms can be modified to solve CVP and its variants as well. Our
first method is aimed at solving one problem instance and minimizes the overall
time complexity for a single CVP instance with a time complexity of
$2^{0.292d}$. Our second method minimizes the amortized time complexity for
several instances on the same lattice, at the cost of a larger preprocessing
cost. We can solve the closest vector problem with preprocessing (CVPP) with
$2^{0.636d}$ space and preprocessing, in $2^{0.136d}$ time, while the query
complexity can even be reduced to $2^{\epsilon d}$ at the cost of preprocessing
time and memory complexities of $(1/\epsilon)^{O(d)}$.
  For easier variants of CVP, such as approximate CVP and bounded distance
decoding (BDD), we further show how the preprocessing method achieves even
better complexities. For instance, we can solve approximate CVPP with large
approximation factors $k$ with polynomial-sized advice in polynomial time if $k
= \Omega(\sqrt{d/\log d})$, heuristically closing the gap between the
decision-CVPP result of [AR'04] and the search-CVPP result of [DRS'14].


title:
Lower consistency bounds for mutual stationarity with divergent
  uncountable cofinalities

abstract:
  We prove that the upper bounds for the consistency strength of certain
instances of mutual stationarity considered by Liu-Shelah~\cite{MR1469093} are
close to optimal. We also consider some related and, as it turns out, stronger
properties.


title:
Relativistic Dynamics of Relative Motions (I): Post-Newtonian Extension
  of the Hill-Clohessy-Wiltshire Equations

abstract:
  With continuous advances in technologies related to deep space ranging and
satellite gravity gradiometry, corrections from general relativity to the
dynamics of relative orbital motions will certainly become important. In this
work, we extend,in a systematic way, the Hill-Clohessy-Wiltshire Equations to
include the complete first order post-Newtonian effects from general
relativity. Within certain short time limit, post-Newtonian corrections to
general periodic solutions of the Hill-Clohessy-Wiltshire Equations are also
worked out.


title:
Unconventional ratiometric-enhanced optical sensing of oxygen by
  mixed-phase TiO2

abstract:
  We show that mixed-phase titanium dioxide (TiO2) can be effectively employed
as an unconventional, inorganic, dual-emitting and ratiometric optical sensor
of O2. Simultaneous availability of rutile and anatase TiO2 PL and their
peculiar anti-correlated PL responses to O2 allow using their ratio as
measurement parameter associated to O2 concentration, leading to an
experimental responsivity being by construction larger than the one obtainable
for single-phase PL detection. A proof of this concept in given, showing a
two-fold enhancement of the optical responsivity provided by the ratiometric
approach. Besides the peculiar ratiometric-enhanced responsivity, other
characteristics of mixed phase TiO2 can be envisaged as favorable for O2
optical probing, namely: a) low production costs, b) absence of heterogeneous
components, c) self-supporting properties. These characteristics encourage
experimenting its use for applications requiring high indicator quantities at
competitive price, possibly also tackling the need to develop supporting
matrixes that carry the luminescent probes and avoiding issues related to the
use of different components for ratiometric sensing.


title: Learning to Decode Linear Codes Using Deep Learning

abstract:
  A novel deep learning method for improving the belief propagation algorithm
is proposed. The method generalizes the standard belief propagation algorithm
by assigning weights to the edges of the Tanner graph. These edges are then
trained using deep learning techniques. A well-known property of the belief
propagation algorithm is the independence of the performance on the transmitted
codeword. A crucial property of our new method is that our decoder preserved
this property. Furthermore, this property allows us to learn only a single
codeword instead of exponential number of code-words. Improvements over the
belief propagation algorithm are demonstrated for various high density parity
check codes.


title:
Detailed crystallographic analysis of the ice VI to ice XV hydrogen
  ordering phase transition

abstract:
  The D2O ice VI to ice XV hydrogen ordering phase transition at ambient
pressure is investigated in detail with neutron diffraction. The lattice
constants are found to be sensitive indicators for hydrogen ordering. The a and
b lattice constants contract whereas a pronounced expansion in c is found upon
hydrogen ordering. Overall, the hydrogen ordering transition goes along with a
small increase in volume which explains why the phase transition is more
difficult to observe upon cooling under pressure. Slow-cooling ice VI at 1.4
GPa gives essentially fully hydrogen-disordered ice VI. Consistent with earlier
studies, the ice XV obtained after slow-cooling at ambient pressure is best
described with P-1 space group symmetry. Using a new computational approach, we
achieve the atomistic reconstruction of a supercell structure that is
consistent with the average partially ordered structure derived from Rietveld
refinements. This shows that C-type networks are most prevalent in ice XV but
other structural motifs outside of the classifications of the fully
hydrogen-ordered networks are identified as well. The recently proposed Pmmn
structural model for ice XV is found to be incompatible with our diffraction
data and we argue that only structural models that are capable of describing
full hydrogen order should be used.


title: Superconducting State and Phase Transitions

abstract:
  From the days when superconductivity was discovered its science was entangled
by the unresolved problem of the relationship between superconductive state,
its crystal structure and its phase transitions. The problem was exacerbated by
the adjacent scientific area - solid state phase transitions - that offered to
divide phase transitions into first and second order. Adding to that the
conclusion (turned out erroneous)on the structural identity of the
superconductor and normal phases, the whole issue was uncertain and confusing.
This article straights it out.


title:
Objective Bayesian modelling of insurance risks with the skewed
  Student-t distribution

abstract:
  Insurance risks data typically exhibit skewed behaviour. In this paper, we
propose a Bayesian approach to capture the main features of these datasets.
This work extends the methodology introduced in Villa and Walker (2014a) by
considering an extra parameter which captures the skewness of the data. In
particular, a skewed Student-t distribution is considered. Two datasets are
analysed: the Danish fire losses and the US indemnity loss. The analysis is
carried with an objective Bayesian approach. For the discrete parameter
representing the number of the degrees of freedom, we adopt a novel prior
recently introduced in Villa and Walker (2014b).


title: Admissible Spaces for the Sturm-Liouville Equation

abstract:
  We consider the equation
  \begin{equation} -y''(x)+q(x)y(x)=f(x),\quad x\in \mathbb R
  \end{equation}
  where $ f \in L_p^{loc}(\mathbb R),$ $p \in [1,\infty) $ and $ 0 < q \in
L_1^{loc}(\mathbb R).$ By a solution of this equation we mean any function $
y,$ absolutely continuous together with its derivative and satisfying the
equation almost everywhere in $ \mathbb R.$ Let positive and continuous
functions $ \mu(x) $ and $ \theta(x) $ for $ x \in \mathbb R $ be given. Let us
introduce the spaces
  $ L_p(\mathbb R,\mu) = \{f \in L_p^{loc}(\mathbb R): ||f||_{L_p(\mathbb
R,\mu)}^p =\int_{-\infty}^\infty|\mu(x)f(x)|^p dx < \infty\}, $
  $ L_p(\mathbb R,\theta) = \{f\in L_p^{loc}(\mathbb R):||f||_{L_p(\mathbb
R,\theta)}^p = \int_{-\infty}^\infty|\theta(x)f(x)|^p dx < \infty\}. $
  In the present paper, we obtain requirements to the functions $\mu,\theta$
and $q$ under which
  1) for every function $f \in L_p(\mathbb R,\theta) $ there exists a unique
solution of the equation $y \in L_p(\mathbb R,\mu)$ ;
  2) there is an absolute constant $ c(p) \in (0,\infty) $ such that regardless
of he choice of a function $ f \in L_p(\mathbb R,\theta) $ the solution of the
equation satisfies the inequality
  $$ \|y\|_{L_p(\mathbb R,\mu)} < c(p)\|f\|_{L_p(\mathbb R,\theta)}. $$


title: Distributed Localization of Tree-structured Scattered Sensor Networks

abstract:
  Many of the distributed localization algorithms are based on relaxed
optimization formulations of the localization problem. These algorithms
commonly rely on first-order optimization methods, and hence may require many
iterations or communications among computational agents. Furthermore, some of
these distributed algorithms put a considerable computational demand on the
agents. In this paper, we show that for tree-structured scattered sensor
networks, which are networks that their inter-sensor range measurement graphs
have few edges (few range measurements among sensors) and can be represented
using a tree, it is possible to devise an efficient distributed localization
algorithm that solely relies on second-order methods. Particularly, we apply a
state-of-the-art primal-dual interior-point method to a semidefinite relaxation
of the maximum-likelihood formulation of the localization problem. We then show
how it is possible to exploit the tree-structure in the network and use
message-passing or dynamic programming over trees, to distribute computations
among different computational agents. The resulting algorithm requires far
fewer iterations and communications among agents to converge to an accurate
estimate. Moreover, the number of required communications among agents, seems
to be less sensitive and more robust to the number of sensors in the network,
the number of available measurements and the quality of the measurements. This
is in stark contrast to distributed algorithms that rely on first-order
methods. We illustrate the performance of our algorithm using experiments based
on simulated and real data.


title: The Shear Viscosity in an Anisotropic Unitary Fermi Gas

abstract:
  We consider a system consisting of a strongly interacting, ultracold unitary
Fermi gas under harmonic confinement. Our analysis suggests the possibility of
experimentally studying, in this system, an anisotropic shear viscosity tensor
driven by the anisotropy in the trapping potential. In particular, we suggest
that this experimental setup could mimic some features of anisotropic
geometries that have recently been studied for strongly coupled field theories
which have a gravitational dual. Results using the AdS/CFT correspondence in
these theories show that in systems with a background linear potential, certain
viscosity components can be made much smaller than the entropy density,
parametrically violating the bound proposed by Kovtun, Son and Starinets (KSS).
This intuition, along with results from a Boltzmann analysis that we perform,
suggests that a violation of the KSS bound can perhaps occur in the unitary
Fermi gas system when it is subjected to a suitable anisotropic trapping
potential which may be approximated to be linear in a suitable range of
parameters.
  We give a concrete proposal for an experimental setup where an anisotropic
shear viscosity tensor may arise. In such situations, it may also be possible
to observe a reduction in the spin one component of the shear viscosity from
its lowest value observed so far in ultracold Fermi gases. In extreme
anisotropic situations, the reduction may be enough to reduce the shear
viscosity to entropy ratio below the proposed KSS bound, although this regime
is difficult to analyze in a theoretically controlled manner.