title:
Semi-Stochastic Frank-Wolfe Algorithms with Away-Steps for
  Block-Coordinate Structure Problems

abstract:
  We propose a semi-stochastic Frank-Wolfe algorithm with away-steps for
regularized empirical risk minimization and extend it to problems with
block-coordinate structure. Our algorithms use adaptive step-size and we show
that they converge linearly in expectation. The proposed algorithms can be
applied to many important problems in statistics and machine learning including
regularized generalized linear models, support vector machines and many others.
In preliminary numerical tests on structural SVM and graph-guided fused LASSO,
our algorithms outperform other competing algorithms in both iteration cost and
total number of data passes.


title:
Effect of doping and In-composition on gain of long wavelength
  III-nitride QDs

abstract:
  In this work, we calculate material gain for long wavelength III-nitride InN
and AlInN quantum dot (QD) structures. Strain and QD inhomogeneity are included
in the calculations. The study covers (800-2300 nm) wavelength range which is
important in optical communications. While p-doping is shown to be efficient to
increasing gain, changing QD size (especially QD radius) is more efficient to
vary wavelength. The results predicted that n-doped QD structures are promises
for broad band laser applications.


title: Correction of Data and Syndrome Errors by Stabilizer Codes

abstract:
  Performing active quantum error correction to protect fragile quantum states
highly depends on the correctness of error information--error syndromes. To
obtain reliable error syndromes using imperfect physical circuits, we propose
the idea of quantum data-syndrome (DS) codes that are capable of correcting
both data qubits and syndrome bits errors. We study fundamental properties of
quantum DS codes and provide several CSS-type code constructions of quantum DS
codes.


title: Four-wave mixing in long wavelength III-nitride QD-SOAs

abstract:
  Four wave mixing analysis is stated for quantum dot semiconductor optical
amplifiers (QD SOAs) using the propagation equations (including nonlinear
propagation contribution) coupled with the QD rate equations under the
saturation assumption. Long wavelength III-nitride InN and AlInN QD SOAs are
simulated. Asymmetric behavior due to linewidth enhancement factor is assigned.
P-doping increases efficiency. Lossless efficiency for InAlN QDs for longer
radii is obtained. Carrier heating is shown to have a considerable effect and a
detuning dependence is expected at most cases. InN QD SOAs shown to have higher
efficiency.


title:
Under a cloud of uncertainty: Legal questions affecting Internet storage
  and transmission of copyright-protected video content

abstract:
  The rapid growth of multimedia consumption has triggered technical, economic,
and business innovations that improve the quality and accessibility of content.
It has also opened new markets, promising large revenues for industry players.
However, new technologies also pose new questions regarding the legal aspects
of content delivery, which are often resolved through litigation between
copyright owners and content distributors. The precedents set by these cases
will act as a game changer in the content delivery industry and will shape the
existing offerings in the market in terms of how new technologies can be
deployed and what kind of pricing strategies can be associated with them. In
this paper, we offer a tutorial on key copyright and communications laws and
decisions related to storage and transmission of video content over the
Internet. We summarize legal limitations on the deployment of new technologies
and pricing mechanisms, and explain the implications of recent lawsuits.
Understanding these concerns is essential for engineers engaged in designing
the technical and economic aspects of video delivery systems.


title: Entangled Bloch Spheres: Bloch Matrix and Two Qubit State Space

abstract:
  We represent a two-qubit density matrix in the basis of Pauli matrix tensor
products, with the coefficients constituting a Bloch matrix, analogous to the
single qubit Bloch vector. We find the quantum state positivity requirements on
the Bloch matrix components, leading to three important inequalities, allowing
us to parametrize and visualize the two-qubit state space. Applying the
singular value decomposition naturally separates the degrees of freedom to
local and nonlocal, and simplifies the positivity inequalities. It also allows
us to geometrically represent a state as two entangled Bloch spheres with
superimposed correlation axes. It is shown that unitary transformations, local
or nonlocal, have simple interpretations as axis rotations or mixing of certain
degrees of freedom. The nonlocal unitary invariants of the state are then
derived in terms of local unitary invariants. The positive partial transpose
criterion for entanglement is generalized, and interpreted as a reflection, or
a change of a single sign. The formalism is used to characterize maximally
entangled states, and generalize two qubit isotropic and Werner states.


title: 1T`-MoTe2 single crystal: a possible topological superconductor

abstract:
  We measured the magnetoresistvity (MR) properties of the 1T`-MoTe2 single
crystal under the magnetic field up to 33 T.By analyzing the Shubnikov de Haas
oscillations of MR at the low temperature, single Fermi surface is
revealed.From the strong oscillatory component of the longitudinal resistance
{\Delta}Rxx,a linear dependence of the Landau index n on 1/B is obtained.The
intercept of the Landau index plot is between 3/8 and 1/2.This clearly reveals
a nontrivial {\pi} Berry`s phase, which is a distinguished feature of Dirac
fermions. Accompanied by the superconductivity observed at TC=0.1 K, 1T`-MoTe2
may be a promising candidate of the topological superconductor.


title:
Using XMM-Newton to study the energy dependent variability of H 1743-322
  during its 2014 outburst

abstract:
  Black hole transients during bright outbursts show distinct changes of their
spectral and variability properties as they evolve during an outburst, that are
interpreted as evidence for changes in the accretion flow and X-ray emitting
regions. We obtained an anticipated XMM-Newton ToO observation of H 1743-322
during its outburst in September 2014. Based on data of eight outbursts
observed in the last 10 years we expected to catch the start of the
hard-to-soft state transition. The fact that neither the general shape of the
observed power density spectrum nor the characteristic frequency show an energy
dependence implies that the source still stays in the low-hard state at the
time of our observation near outburst peak. The spectral properties agree with
the source being in the low-hard state and a Swift/XRT monitoring of the
outburst reveals that H 1743-322 stays in the low-hard state during the entire
outburst (a. k. a. 'failed outburst'). We derive the averaged QPO waveform and
obtain phase-resolved spectra. Comparing the phase-resolved spectra to the
phase averaged energy spectrum reveals spectral pivoting. We compare
variability on long and short time scales using covariance spectra and find
that the covariance ratio does not show an increase towards lower energies as
has been found in other black hole X-ray binaries. There are two possible
explanations: either the absence of additional disc variability on longer time
scales is related to the rather high inclination of H 1743-322 compared to
other black hole X-ray binaries or it is the reason why we observe H 1743-322
during a failed outburst. More data on failed outbursts and on high-inclination
sources will be needed to investigate these two possibilities further.


title:
New Residue Arithmetic Based Barrett Algorithms, Part I: Modular Integer
  Computations

abstract:
  In this paper, we derive new computational techniques for residue number
systems (RNS) based Barrett algorithm (BA). The focus of the work is an
algorithm that carries out the entire computation using only modular arithmetic
without conversion to large integers via the Chinese Remainder Theorem (CRT).
It also avoids the computationally expensive scaling-rounding operation
required in the earlier work. There are two parts to this work. First, we set
up a new BA using two constants other than powers of two. Second, a RNS based
BA is described. A complete mathematical framework is described including
proofs of the various steps in the computations and the validity of results.
Third, we present a computational algorithm for RNS based BA. Fourth, the RNS
based BA is used as a basis for new RNS based algorithms for MoM and MoE. The
applications we are dealing with are in the area of cryptography.


title:
Light Curve Solutions of an Eclipsing Binary OGLE-GD-ECL-04451 with a
  Dramatic Change in Amplitude

abstract:
  We present light curve solutions of the W UMa-type eclipsing binary
OGLE-GD-ECL-04451, observed by both the \emph{Optical Gravitational Lensing
Ex-periment} (\emph{OGLE}) program in 2006 and the \emph{Antarctica Survey
Telescope} (\emph{AST3-1}) in 2012 at Dome A. We analyzed this binary system
with the Wilson-Devinney(W-D) method 2013 version and derived the mass ratio
$q=2.91 \pm 0.07$, the inclination $i=76.86^\circ \pm 0.23^\circ$, and the
light variattion amplitud was $0^m.51$ based on the \emph{OGLE} data. From the
\emph{AST3-1}'s data, we find that the amplitude dropped to $0^m.44$(2012) and
the difference of magnitudes of the two light maxima is $0^m.03$. A hot spot
was then added on the surface of the secondary to demonstrate the amplitude
change and O'Conell effect of the binary system.


title:
New Residue Arithmetic Based Barrett Algorithms, Part II: Modular
  Polynomial Computations

abstract:
  In this paper, we derive a new computational algorithm for Barrett technique
for modular polynomial multiplication, termed BA-P. BA-P is then applied to a
new residue arithmetic based Barrett algorithm for modular polynomial
multiplication (BA-MPM). The focus of the work is an algorithm that carries out
the entire computation using only modular arithmetic without conversion to
large degree polynomials. There are several parts to this work. First, we set
up a new BA-P using polynomials other than u^alfa. Second, residue arithmetic
based BA-MPM is described. A complete mathematical framework is described
including proofs of the steps in the computations and the validity of results.
Third, we present a computational procedure for BA-MPM. Fourth, the BA-MPM is
used as a basis for algorithms for modular polynomial exponentiation (MPE).
Applications are in areas of signal security and cryptography.


title: Strong coupling in multimode quantum electromechanics

abstract:
  Cavity electro-(opto-)mechanics allows us to access not only single isolated
but also multiple mechanical modes in a massive object. Here we develop a
multi-mode electromechanical system in which a several membrane vibrational
modes are coupled to a three-dimensional loop-gap superconducting microwave
cavity. The tight confinement of the electric field across a
mechanically-compliant narrow-gap capacitor brings the system into the quantum
strong coupling regime under a red-sideband pump field. We demonstrate strong
coupling between two mechanical modes, which is induced by two-tone parametric
drives and mediated by a virtual photon in the cavity. The tunable
inter-mechanical-mode coupling can be used to generate entanglement between the
mechanical modes.


title:
Hubble Space Telescope Wide Field Camera 3 Observations of Escaping
  Lyman Continuum Radiation from Galaxies and Weak AGN at Redshifts
  $z$$\,\simeq\,$2.3-4.1

abstract:
  We present observations of escaping Lyman Continuum (LyC) radiation from 34
massive star-forming galaxies and 12 weak AGN with reliably measured
spectroscopic redshifts at $z$$\simeq$2.3-4.1. We analyzed Hubble Space
Telescope Wide Field Camera 3 (WFC3) mosaics of the Early Release Science field
in three UVIS filters to sample the rest-frame LyC over this redshift range.
With our best current assessment of the WFC3 systematics, we provide 1$\sigma$
upper limits for the average LyC emission of galaxies at $z$=2.35, 2.75, and
3.60 to $\sim$28.5, 28.1, and 30.7 mag in image stacks of 11-15 galaxies in the
WFC3/UVIS F225W, F275W, and F336W, respectively. The LyC flux of weak AGN at
$z$=2.62 and 3.32 are detected at 28.3 and 27.4 mag with SNRs of $\sim$2.7 and
2.5 in F275W and F336W for stacks of 7 and 3 AGN, respectively, while AGN at
$z$=2.37 are constrained to $\gtrsim$27.9 mag at 1$\sigma$ in a stack of 2 AGN.
The stacked AGN LyC light profiles are flatter than their corresponding
non-ionizing UV continuum profiles out to radii of r$\lesssim$0."9, which may
indicate a radial dependence of porosity in the ISM. With synthetic stellar
SEDs fit to UV continuum measurements longwards of Ly$\alpha$ and IGM
transmission models, we constrain the absolute LyC escape fractions to $f_{\rm
esc}^{\rm abs}$$\simeq$$22^{+44}_{-22}$% at $z$=2.35 and $\lesssim$55% at
$z$=2.75 and 3.60, respectively. All available data for galaxies, including
published work, suggests a more sudden increase of $f_{\rm esc}$ with redshift
at $z$$\simeq$2. Dust accumulating in (massive) galaxies over cosmic time
correlates with increased HI column density, which may lead to reducing $f_{\rm
esc}$ more suddenly at $z$$\lesssim$2. This may suggest that star-forming
galaxies collectively contributed to maintaining cosmic reionization at
redshifts $z$$\gtrsim$2-4, while AGN likely dominated reionization at
$z$$\lesssim$2.


title:
Magnetic anisotropy of the single-crystalline ferromagnetic insulator
  Cr2Ge2Te6

abstract:
  Cr2Ge2Te6 (CGT), a layered ferromagnetic insulator, has attracted a great
deal of interest recently owing to its potential for integration with Dirac
materials to realize the quantum anomalous Hall effect (QAHE) and to develop
novel spintronics devices. Here, we study the uniaxial magnetic anisotropy
energy of single-crystalline CGT and determine that the magnetic easy axis is
directed along the c-axis in its ferromagnetic phase. In addition, CGT is an
insulator below the Curie temperature. These properties make CGT a potentially
promising candidate substrate for integration with topological insulators for
the realization of the high-temperature QAHE.


title: An ensemble diversity approach to supervised binary hashing

abstract:
  Binary hashing is a well-known approach for fast approximate nearest-neighbor
search in information retrieval. Much work has focused on affinity-based
objective functions involving the hash functions or binary codes. These
objective functions encode neighborhood information between data points and are
often inspired by manifold learning algorithms. They ensure that the hash
functions differ from each other through constraints or penalty terms that
encourage codes to be orthogonal or dissimilar across bits, but this couples
the binary variables and complicates the already difficult optimization. We
propose a much simpler approach: we train each hash function (or bit)
independently from each other, but introduce diversity among them using
techniques from classifier ensembles. Surprisingly, we find that not only is
this faster and trivially parallelizable, but it also improves over the more
complex, coupled objective function, and achieves state-of-the-art precision
and recall in experiments with image retrieval.


title: Polynomial of an oriented surface-link diagram via quantum A_2 invariant

abstract:
  It is known that every surface-link can be presented by a marked graph
diagram, and such a diagram presentation is unique up to moves called Yoshikawa
moves. G. Kuperberg introduced a regular isotopy invariant, called the quantum
A_2 invariant, for tangled trivalent graph diagrams. In this paper, a
polynomial for a marked graph diagram is defined by use of the quantum A_2
invariant and it is studied how the polynomial changes under Yoshikawa moves.
The notion of a ribbon marked graph is introduced to show that this polynomial
is useful for an invariant of a ribbon 2-knot.


title: Superconducting circuit simulator of Bose-Hubbard model with a flat band

abstract:
  Recent advance in quantum simulations of interacting photons using
superconducting circuits offers opportunities for investigating the
Bose-Hubbard model in various geometries with hopping coefficients and
self-interactions tuned to both signs. Here we investigate phenomena related to
localized states associated with a flat-band supported by the saw-tooth
geometry. A localization-delocalization transition emerges in the
non-interacting regime as the sign of hopping coefficient is changed. In the
presence of interactions, patterns of localized states approach a uniform
density distribution for repulsive interactions while interesting localized
density patterns can arise in strongly attractive regime. The density patterns
indicate the underlying inhomogeneity of the simulator. Two-particle
correlations can further distinguish the nature of the localized states in
attractive and repulsive interaction regimes. We also survey possible
experimental implementations of the simulator.


title:
Online energy efficient packet scheduling for a common deadline with and
  without energy harvesting

abstract:
  The problem of online packet scheduling to minimize the required conventional
grid energy for transmitting a fixed number of packets given a common deadline
is considered. The total number of packets arriving within the deadline is
known, but the packet arrival times are unknown, and can be arbitrary. The
proposed algorithm tries to finish the transmission of each packet assuming all
future packets are going to arrive at equal time intervals within the left-over
time. The proposed online algorithm is shown to have competitive ratio that is
logarithmic in the number of packet arrivals. The hybrid energy paradigm is
also considered, where in addition to grid energy, energy is also available via
extraction from renewable sources. The objective here is to minimize the grid
energy use. A suitably modified version of the previous algorithm is also shown
to have competitive ratio that is logarithmic in the number of packet arrivals.


title: $k$-geometric graphs

abstract:
  A finite, simple and undirected graph $G = (V, E)$ with $p$ vertices and $q$
edges is said to be a $k$-geometric mean graph for a positive integer $k$ if
there is an injection $\psi :V(G)\to \{k,k+1,\dots,k+q\}$ such that, when each
edge $uv\in E(G)$ is assigned the label $\lfloor\sqrt{\psi(u)\psi(v)}\rfloor$
or $\lceil\sqrt{\psi(u)\psi(v)}\rceil$, the resulting edge label set is
$\{k,k+1,...,k+q-1\}$ and $\psi$ is called a \emph{$k$-geometric mean labeling}
of $G$. The special case $k=1$, a $1$-geometric mean labeling is called a
geometric mean labeling, and a $1$-geometric mean graph is called a geometric
mean graph.
  In this paper, we present new classes of geometric mean graphs. Then we
introduce $k$-geometric mean labeling and prove some classes of graphs are
$k$-geometric mean. We also study some classes of finite join of graphs that
admit geometric mean labeling.


title:
Highly efficient two photon generation from a coherently pumped quantum
  dot embedded in a microcavity

abstract:
  We propose a scheme to realize a highly efficient solid state source of
photon pairs using cavity-assisted stimulated Raman adiabatic passage (STIRAP)
in a single quantum dot, where a single photon from pump pulse and two stokes
photons from cavity mode drives the Raman transition. The Autler-Townes
doublet, generated by using a resonant continuous wave laser between biexciton
and exciton states, and two-photon-resonant transition through strongly coupled
cavity mode are utilized to facilitate (1+2)type Raman transition in the
quantum dot. We show in the case of weak pump although the probability of
generating two photons in cavity mode is small without cavity damping but
two-photon-resonant emission is enhanced by cavity damping within strong
coupling regime. We also discuss spectrum of the generated photon pair and
photon-photon correlations in the generated photon pair. The efficiency of two
photon source could be more than 80\% in current experimental conditions.


title: A Brief Review of Helmholtz Conditions

abstract:
  It is well known that the equations of motion obtained from Newtons second
law of motion can be obtained from a Lagrangian via the Euler-Lagrangian
formulation if and only if the equations of motion satisfy the Helmholtz
conditions. In this pedagogical article we give a simple proof of the above
statement and show its application to simple mechanical and dissipative
systems.


title:
Beam energy dependence of Hanbury-Brown-Twiss radii from a blast-wave
  model

abstract:
  The beam energy dependence of correlation lengths (the Hanbury-Brown-Twiss
radii) is calculated by using a blast-wave model and the results are comparable
with those from RHIC-STAR beam energy scan data as well as the LHC-ALICE
measurements. A set of parameter for the blast-wave model as a function of beam
energy under study are obtained by fit to the HBT radii at each energy point.
The transverse momentum dependence of HBT radii is presented with the extracted
parameters for Au + Au collision at $\sqrt{s_{NN}} = $ 200 GeV and for Pb+Pb
collisions at 2.76 TeV. From our study one can learn that particle emission
duration can not be ignored while calculating the HBT radii with the same
parameters. And tuning kinetic freeze-out temperature in a range will result in
system lifetime changing in the reverse direction as it is found in RHIC-STAR
experiment measurements.


title:
Context-Aware Scheduling of Joint Millimeter Wave and Microwave
  Resources for Dual-Mode Base Stations

abstract:
  One of the most promising approaches to overcome the drastic channel
variations of millimeter wave (mmW) communications is to deploy dual-mode base
stations that integrate both mmW and microwave (\muW) frequencies. Reaping the
benefits of a dual-mode operation requires scheduling mechanisms that can
allocate resources efficiently and jointly at both frequency bands. In this
paper, a novel resource allocation framework is proposed that exploits users'
context, in terms of user application (UA) delay requirements, to maximize the
quality-of-service (QoS) of a dual-mode base station. In particular, such a
context-aware approach enables the network to dynamically schedule UAs, instead
of users, thus providing more precise delay guarantees and a more efficient
exploitation of the mmW resources. The scheduling of UAs is formulated as a
one-to-many matching problem between UAs and resources and a novel algorithm is
proposed to solve it. The proposed algorithm is shown to converge to a
two-sided stable matching between UAs and network resources. Simulation results
show that the proposed approach outperforms classical CSI-based scheduling in
terms of the per UA QoS, yielding up to 36% improvement. The results also show
that exploiting mmW resources provides significant traffic offloads reaching up
to 43% from \muW band.


title: Testing Einstein's Weak Equivalence Principle With Gravitational Waves

abstract:
  A conservative constraint on the Einstein Weak Equivalence Principle (WEP)
can be obtained under the assumption that the observed time delay between
correlated particles from astronomical sources is dominated by the
gravitational fields through which they move. Current limits on the WEP are
mainly based on the observed time delays of photons with different energies. It
is highly desirable to develop more accurate tests that include the
gravitational wave (GW) sector. The detection by the advanced LIGO/VIRGO
systems of gravitational waves will provide attractive candidates for
constraining the WEP, extending the tests to gravitational interactions, with
potentially higher accuracy. Considering the capabilities of the advanced
LIGO/VIRGO network and the source direction uncertainty, we show that the joint
detection of GWs and electromagnetic signals could probe the WEP to an accuracy
down to $10^{-10}$, which is one order of magnitude tighter than previous
limits, and seven orders of magnitude tighter than the multi-messenger (photons
and neutrinos) results by supernova 1987A.


title: Testing Wireless Sensor Networks with Hybrid Simulators

abstract:
  Software development for Wireless Sensor Networks (WSNs) is challenging due
to characteristics of sensor nodes and the environment they are deployed in.
Testing software in a real WSN testbed allows users to get reliable test
results. However, real testbeds become more expensive as the number of sensor
nodes in the network grows. Simulation tools are alternatives to real testbeds.
They are cheaper, faster and repeatable. However, simulation results are not
reliable as that of testbeds. Therefore, there is a need for a testing tool
that can leverage the advantages of testbeds and simulation tools. These tools
are usually called hybrid simulators. In this survey, we discuss several hybrid
simulators that use real sensor motes integrated with a simulator to make
software development cheaper, repeatable and to make the results more reliable.


title: Proximal Cantor systems with topological rank 2 are residually scrambled

abstract:
  Downarowicz and Maass (2008) proposed topological ranks for all homeomorphic
Cantor minimal dynamical systems using properly ordered Bratteli diagrams. In
this study, we adopt this definition to the case of all essentially minimal
zero-dimensional systems. We consider the cases in which topological ranks are
2 and unique minimal sets are fixed points. Akin and Kolyada (2003), in their
study of Li--Yorke sensitivity, showed that if the unique minimal set of an
essentially minimal system is a fixed point, then the system must be proximal.
However, a finite topological rank implies expansiveness; furthermore, in the
case of proximal Cantor systems with topological rank 2, the expansiveness is
always from the lowest degree.
  Rank 2 zero-dimensional systems might be thought as a part of the rank 1
transformations that are considered in the vast field of ergodic theory.
However, these systems are also interesting from the perspective of topological
chaos theory; e.g., in this study, we show that all proximal Cantor systems
with topological rank 2 are residually scrambled. In addition, we investigate
the finite invariant measures on these systems. Evidently, such systems have at
most two ergodic measures. We present a necessary and sufficient condition for
the unique ergodicity of these systems. In addition, we show that the number of
ergodic measures of systems that are topologically mixing can be 1 and 2.
Moreover, we present examples that are topologically weakly mixing, not
topologically mixing, and uniquely ergodic. Finally, we show that the number of
ergodic measures of systems that are not weakly mixing can be 1 and 2.


title:
Unraveling the Rank-One Solution Mystery of Robust MISO Downlink
  Transmit Optimization: A Verifiable Sufficient Condition via a New Duality
  Result

abstract:
  This paper concentrates on a robust transmit optimization problem for the
multiuser multi-input single-output (MISO) downlink scenario and under
inaccurate channel state information (CSI). This robust problem deals with a
general-rank transmit covariance design, and it follows a safe rate-constrained
formulation under spherically bounded CSI uncertainties. Curiously, simulation
results in previous works suggested that the robust problem admits rank-one
optimal transmit covariances in most cases. Such a numerical finding is
appealing because transmission with rank-one covariances can be easily realized
by single-stream transmit beamforming. This gives rise to a fundamentally
important question, namely, whether we can theoretically identify conditions
under which the robust problem admits a rank-one solution. In this paper, we
identify one such condition. Simply speaking, we show that the robust problem
is guaranteed to admit a rank-one solution if the CSI uncertainties are not too
large and the multiuser channel is not too poorly conditioned. To establish the
aforementioned condition, we develop a novel duality framework, through which
an intimate relationship between the robust problem and a related maximin
problem is revealed. Our condition involves only a simple expression with
respect to the multiuser channel and other system parameters. In particular,
unlike other sufficient rank-one conditions that have appeared in the
literature, ours is verifiable. The application of our analysis framework to
several other CSI uncertainty models is also discussed.


title:
Transverse writing of three-dimensional tubular optical waveguides in
  glass with slit-shaped femtosecond laser beams

abstract:
  We report on fabrication of tubular optical waveguides buried in ZBLAN glass
based on transverse femtosecond laser direct writing. Irradiation in ZBLAN with
focused femtosecond laser pulses leads to decrease of refractive index in the
modified region. Tubular optical waveguides of variable mode areas are
fabricated by forming the four sides of the cladding with slit-shaped
femtosecond laser pulses, ensuring single mode waveguiding with a mode field
dimension as small as ~ 4 {\mu}m.


title:
The existence of bound states in a system of three particles in an
  optical lattice

abstract:
  We consider the hamiltonian $\mathrm{H}_{\mu},\mu\in \R$ of a system of
three-particles (two identical fermions and one different particle) moving on
the lattice ${\Z}^d ,\, d=1,2 $ interacting through repulsive $(\mu>0)$ or
attractive $(\mu<0)$ zero-range pairwise potential $\mu V$. We prove for any
$\mu\ne0$ the existence of bound state of the discrete three-particle
Schr\"odinger operator $H_{\mu}(K),\,K\in \T^d$ being the three-particle
quasi-momentum, associated to the hamiltonian $\mathrm{H}_{\mu}$.


title:
On smoothness of minimal models of quotient singularities by finite
  subgroups of $SL_n(\mathbb{C})$

abstract:
  We prove that a quotient singularity $\mathbb{C}^n/G $ by a finite subgroup
$G\subset SL_n(\mathbb{C})$ has a crepant resolution only if $G $ is generated
by junior elements. This is a generalization of the result of Verbitsky [V]. We
also give a procedure to compute the Cox ring of a minimal model of a given
$\mathbb{C}^n/G$ explicitly from information of $G$. As an application, we
investigate the smoothness of minimal models of some quotient singularities.
Together with work of Bellamy and Schedler, this completes the classification
of symplectically imprimitive quotient singularities which admit projective
symplectic resolutions.


title:
A reformulation of the generalized $q$-Painlev\'{e} VI system with
  $W(A^{(1)}_{2n+1})$ symmetry

abstract:
  In the previous work we introduced the higher order $q$-Painlev\'{e} system
$q$-$P_{(n+1,n+1)}$ as a generalization of the Jimbo-Sakai's $q$-Painlev\'{e}
VI equation. It is derived from a $q$-analogue of the Drinfeld-Sokolov
hierarchy of type $A^{(1)}_{2n+1}$ and admits a particular solution in terms of
the Heine's $q$-hypergeometric function ${}_{n+1}\phi_n$. However the obtained
system is insufficient as a generalization of $q$-$P_{\rm{VI}}$ due to some
reasons. In this article we rewrite the system $q$-$P_{(n+1,n+1)}$ to a more
suitable one.


title:
On the ferroelectric and magnetoelectric mechanisms in low Fe$^{3+}$
  doped TbMnO$_3$

abstract:
  This work addresses the effect of substituting Mn$^{3+}$ by Fe$^{3+}$ at the
octahedral site of TbMnO$_3$ on the magnetic phase sequence, ferroelectric and
magnetoelectric properties, keeping the Fe$^{3+}$ concentration below 5%. The
temperature dependence of the specific heat, dielectric permittivity and
electric polarization was studied as a function of Fe$^{3+}$ concentration and
applied magnetic field. From the experimental results a strong decrease of the
electric polarization with increasing Fe$^{3+}$ substitution is observed,
vanishing above a concentration of 4%. However, within this range, a
significant increase of the magnetic sensitivity of the electric polarization
is obtained by increasing Fe$^{3+}$ concentration. Above that value, a
non-polar, weak ferromagnetic phase emerges, in good agreement with the
predictions of the Dzyalowshinskii-Moriya model. This behavior reveals the
crucial effect of Fe$^{3+}$ substitution in octahedral sites on the magnetic
phase sequence, polar and magnetoelectric behavior of the
TbMn$_{1-x}$Fe$_x$O$_3$ system. From the results obtained in this work, it is
understood that this behavior is not associated with the eg electronic
configuration, but instead to the competition between ferromagnetic and
antiferromagnetic interactions, which is very sensitive to both local fields
and distortions.


title: An M dwarf Companion to an F-type Star in a young main-sequence binary

abstract:
  Only a few well characterized very low-mass M dwarfs are known today. Our
understanding of M dwarfs is vital as these are the most common stars in our
solar neighborhood. We aim to characterize the properties of a rare F+dM
stellar system for a better understanding of the low-mass end of the
Hertzsprung-Russel diagram. We used photometric light curves and radial
velocity follow-up measurements to study the binary. Spectro- scopic analysis
was used in combination with isochrone fitting to characterize the primary
star. The primary star is an early F-type main-sequence star with a mass of
(1.493 +- 0.073) Msun and a radius of (1.474 +- 0.040) Rsun. The companion is
an M dwarf with a mass of (0.188 +- 0.014) Msun and a radius of (0.234 +-
0.009) Rsun. The orbital period is (1.35121 +- 0:00001)d. The secondary star is
among the lowest-mass M dwarfs known to date. The binary has not reached a 1:1
spin-orbit synchronization. This indicates a young main-sequence binary with an
age below ~250 Myrs. The mass-radius relation of both components are in
agreement with this finding.


title:
A Factorized Recurrent Neural Network based architecture for medium to
  large vocabulary Language Modelling

abstract:
  Statistical language models are central to many applications that use
semantics. Recurrent Neural Networks (RNN) are known to produce state of the
art results for language modelling, outperforming their traditional n-gram
counterparts in many cases. To generate a probability distribution across a
vocabulary, these models require a softmax output layer that linearly increases
in size with the size of the vocabulary. Large vocabularies need a
commensurately large softmax layer and training them on typical laptops/PCs
requires significant time and machine resources. In this paper we present a new
technique for implementing RNN based large vocabulary language models that
substantially speeds up computation while optimally using the limited memory
resources. Our technique, while building on the notion of factorizing the
output layer by having multiple output layers, improves on the earlier work by
substantially optimizing on the individual output layer size and also
eliminating the need for a multistep prediction process.


title: New Coupled Codes Constructed by Overlapping Circular SC-LDPC Codes

abstract:
  In this paper, we propose new coupled codes constructed by overlapping
circular spatially-coupled low-density parity-check (SC-LDPC) codes, which show
better asymptotic and finite-length decoding performance compared to the
conventional SC-LDPC codes. The performance improvement comes from the property
that the proposed codes effectively split into two separated SC-LDPC codes with
shorter chain length during the decoding process. We verify that the property
of the proposed codes is valid in asymptotic setting via analysis tools such as
the density evolution and the expected graph evolution. Experimental results
show that the proposed codes also outperform the conventional SC-LDPC codes in
terms of the finite-length performance under belief propagation decoding.


title: Modeling the relation between income and commuting distance

abstract:
  We discuss the distribution of commuting distances and its relation to
income. Using data from Denmark, the UK, and the US, we show that the commuting
distance is (i) broadly distributed with a slow decaying tail that can be
fitted by a power law with exponent $\gamma \approx 3$ and (ii) an average
growing slowly as a power law with an exponent less than one that depends on
the country considered. The classical theory for job search is based on the
idea that workers evaluate the wage of potential jobs as they arrive
sequentially through time, and extending this model with space, we obtain
predictions that are strongly contradicted by our empirical findings. We
propose an alternative model that is based on the idea that workers evaluate
potential jobs based on a quality aspect and that workers search for jobs
sequentially across space. We also assume that the density of potential jobs
depends on the skills of the worker and decreases with the wage. The predicted
distribution of commuting distances decays as $1/r^{3}$ and is independent of
the distribution of the quality of jobs. We find our alternative model to be in
agreement with our data. This type of approach opens new perspectives for the
modeling of mobility.


title: Isospin properties of quark matter from a 3-flavor NJL model

abstract:
  We have studied the properties of hot and dense quark matter based on the
3-flavor Nambu-Jona-Lasinio (NJL) model as well as its Polyakov-loop extension
(pNJL) with scalar-isovector and vector-isovector couplings. Provided a
considerable large isospin asymmetry or isospin chemical potential, isospin
splittings of constituent mass, chiral phase transition boundary, and critical
point for $u$ and $d$ quarks can be observed for positive isovector coupling
constants but are suppressed for negative ones. The quark matter symmetry
energy decreases with the increasing isovector coupling constant, and is mostly
enhanced in the pNJL model than in the NJL model. A positive scalar-isovector
coupling constant is more likely to lead to an unstable isospin asymmetric
quark matter. The isovector coupling has been further found to affect particle
fractions as well as the equation of state in hybrid stars. Possible effects on
the isospin properties of quark matter have also been discussed if the
strangeness sector is further broken among the flavor symmetry.


title: Long-term Planning by Short-term Prediction

abstract:
  We consider planning problems, that often arise in autonomous driving
applications, in which an agent should decide on immediate actions so as to
optimize a long term objective. For example, when a car tries to merge in a
roundabout it should decide on an immediate acceleration/braking command, while
the long term effect of the command is the success/failure of the merge. Such
problems are characterized by continuous state and action spaces, and by
interaction with multiple agents, whose behavior can be adversarial. We argue
that dual versions of the MDP framework (that depend on the value function and
the $Q$ function) are problematic for autonomous driving applications due to
the non Markovian of the natural state space representation, and due to the
continuous state and action spaces. We propose to tackle the planning task by
decomposing the problem into two phases: First, we apply supervised learning
for predicting the near future based on the present. We require that the
predictor will be differentiable with respect to the representation of the
present. Second, we model a full trajectory of the agent using a recurrent
neural network, where unexplained factors are modeled as (additive) input
nodes. This allows us to solve the long-term planning problem using supervised
learning techniques and direct optimization over the recurrent neural network.
Our approach enables us to learn robust policies by incorporating adversarial
elements to the environment.


title: On the Construction of High Dimensional Simple Games

abstract:
  Voting is a commonly applied method for the aggregation of the preferences of
multiple agents into a joint decision. If preferences are binary, i.e., "yes"
and "no", every voting system can be described by a (monotone) Boolean function
$\chi\colon\{0,1\}^n\rightarrow \{0,1\}$. However, its naive encoding needs
$2^n$ bits. The subclass of threshold functions, which is sufficient for
homogeneous agents, allows a more succinct representation using $n$ weights and
one threshold. For heterogeneous agents, one can represent $\chi$ as an
intersection of $k$ threshold functions. Taylor and Zwicker have constructed a
sequence of examples requiring $k\ge 2^{\frac{n}{2}-1}$ and provided a
construction guaranteeing $k\le {n\choose {\lfloor n/2\rfloor}}\in 2^{n-o(n)}$.
The magnitude of the worst-case situation was thought to be determined by
Elkind et al.~in 2008, but the analysis unfortunately turned out to be wrong.
Here we uncover a relation to coding theory that allows the determination of
the minimum number $k$ for a subclass of voting systems. As an application, we
give a construction for $k\ge 2^{n-o(n)}$, i.e., there is no gain from a
representation complexity point of view.


title: SDCA without Duality, Regularization, and Individual Convexity

abstract:
  Stochastic Dual Coordinate Ascent is a popular method for solving regularized
loss minimization for the case of convex losses. We describe variants of SDCA
that do not require explicit regularization and do not rely on duality. We
prove linear convergence rates even if individual loss functions are
non-convex, as long as the expected loss is strongly convex.


title:
Simulation of the Efficiency of CdS/CdTe Tandem Multi-Junction Solar
  Cells

abstract:
  In this paper we study CdS/CdTe solar cells by means of AMPS-1D software.
First we study the effect of thickness of semiconductor layers on the output
parameters of the CdS/CdTe solar cell, such as density of short-circuit
current, open circuit voltage, fill factor and efficiency. Numerical simulation
shows that the highest efficiency of single-junction CdS/CdTe solar cell equal
to 18.3% is achieved when the CdTe layer thickness is 1000 nm and a CdS layer
is 60 nm. Then, in order to obtain the maximal value of the efficiency, new
tandem multi-junction structure consisting of layers of two solar cells
connected with each other back to back are designed and engineered taking into
account the results obtained for the single-junction solar cells. Numerical
simulations show that its highest efficiency in 31.8% can be obtained when the
thickness of CdS p-layer is equal to 50 nm, and the thickness of the CdS
n-layer is equal to 200 nm, while thicknesses of the CdTe n-layer and CdTe
p-layer are kept fixed and equal to 3000 nm and 1000 nm, respectively.


title:
Single-photon-driven high-order sideband transitions in an ultrastrongly
  coupled circuit quantum electrodynamics system

abstract:
  We report the experimental observation of high-order sideband transitions at
the single-photon level in a quantum circuit system of a flux qubit
ultrastrongly coupled to a coplanar waveguide resonator. With the coupling
strength reaching 10% of the resonator's fundamental frequency, we obtain clear
signatures of higher-order red and first-order blue-sideband transitions, which
are mainly due to the ultrastrong Rabi coupling. Our observation advances the
understanding of ultrastrongly-coupled systems and paves the way to study
high-order processes in the quantum Rabi model at the single-photon level.


title:
Ups and Downs: Modeling the Visual Evolution of Fashion Trends with
  One-Class Collaborative Filtering

abstract:
  Building a successful recommender system depends on understanding both the
dimensions of people's preferences as well as their dynamics. In certain
domains, such as fashion, modeling such preferences can be incredibly
difficult, due to the need to simultaneously model the visual appearance of
products as well as their evolution over time. The subtle semantics and
non-linear dynamics of fashion evolution raise unique challenges especially
considering the sparsity and large scale of the underlying datasets. In this
paper we build novel models for the One-Class Collaborative Filtering setting,
where our goal is to estimate users' fashion-aware personalized ranking
functions based on their past feedback. To uncover the complex and evolving
visual factors that people consider when evaluating products, our method
combines high-level visual features extracted from a deep convolutional neural
network, users' past feedback, as well as evolving trends within the community.
Experimentally we evaluate our method on two large real-world datasets from
Amazon.com, where we show it to outperform state-of-the-art personalized
ranking measures, and also use it to visualize the high-level fashion trends
across the 11-year span of our dataset.


title: Dephasing of an Electronic Two-Path Interferometer

abstract:
  This work was motivated by the quest for observing interference of
fractionally charged quasi particles. Here, we study the behavior of an
electronic Mach-Zehnder interferometer (MZI) at the integer quantum Hall effect
(IQHE) regime at filling factors greater than one. Both the visibility and the
drift velocity were measured, and were found to be highly correlated as
function of filling factor. As the filling factor approached unity, the
visibility quenched, not to recover for filling factors smaller than unity.
Alternatively, the velocity saturated around a minimal value at unity filling
factor. We highlight the significant role interactions between the interfering
edge and the bulk play, as well as that of the defining potential at the edge.
Shot noise measurements suggest that phase-averaging (due to phase
randomization), rather than single particle decoherence, is likely to be the
cause of the dephasing in the fractional regime.


title:
A Banach-Dieudonn\'e theorem for the space of bounded continuous
  functions on a separable metric space with the strict topology

abstract:
  Let X be a separable metric space and let \beta be the strict topology on the
space of bounded continuous functions on X, which has the space of
\tau-additive Borel measures as a continuous dual space. We prove a
Banach-Dieudonne\'{e} type result for the space of bounded continuous functions
equipped with \beta. As a consequence, this space is hypercomplete and a
Pt\'{a}k space. Additionally, the closed graph, inverse mapping and open
mapping theorems holds for linear maps between space of this type.


title:
Low-energy hypernuclear spectra with microscopic particle-rotor model
  with relativistic point coupling hyperon-nucleon interaction

abstract:
  We extend the microscopic particle-rotor model for hypernuclear low-lying
states by including the derivative and tensor coupling terms in the
point-coupling nucleon-$\Lambda$ particle ($N\Lambda$) interaction. Taking
$^{13}_{~\Lambda}$C as an example, we show that a good overall description for
excitation spectra is achieved with four sets of effective $N\Lambda$
interaction. We find that the $\Lambda$ hyperon binding energy decreases
monotonically with increasing the strengths of the high-order interaction
terms. In particular, the tensor coupling term decreases the energy splitting
between the first $1/2^-$ and $3/2^-$ states and increases the energy splitting
between the first $3/2^+$ and $5/2^+$ states in $^{13}_{~\Lambda}$C.


title:
Large diffusion lengths of excitons in perovskite and ${\it TiO_2}$
  heterojunction

abstract:
  Solar cells based on organometal halide perovskites have recently become very
promising among other materials because of their cost-effective character and
improvements in efficiency. Such performance is primarily associated with
effective light absorption and large diffusion length of charge carriers. Our
paper is devoted to the explanation of large diffusion lengths in these
systems. The transport mean free path of charged carriers in a perovskite/${\it
TiO_2}$ heterojunction that is an important constituent of the solar cells have
been analyzed. Large transport length is explained by the planar diffusion of
indirect excitons. Diffusion length of the coupled system increases by several
orders compared to single carrier length due to the correlated character of the
effective field acting on the exciton.


title: On nilpotent evolution algebras

abstract:
  The type and several invariant subspaces related to the upper annihilating
series of finite-dimensional nilpotent evolution algebras are introduced. These
invariants can be easily computed from any natural basis. Some families of
nilpotent evolution algebras, defined in terms of a nondegenerate symmetric
bilinear form and some commuting symmetric diagonalizable endomorphisms
relative to the form, are explicitly constructed. Both the invariants and these
families are used to review and complete the classification of nilpotent
evolution algebras up to dimension five over algebraically closed fields.


title: A Partial Proof of a Conjecture of Dris

abstract:
  Euler showed that if an odd perfect number $N$ exists, it must consist of two
parts $N=q^k n^2$, with $q$ prime, $q \equiv k \equiv 1 \pmod{4}$, and
gcd$(q,n)=1$. Dris conjectured that $q^k < n$. We first show that $q<n$ for all
odd perfect numbers. Afterwards, we show $q^k < n$ holds in many cases.


title: Algebras of partial triangulations

abstract:
  We introduce two classes of algebras coming from partial triangulations of
marked surfaces. The first one, called frozen algebra of a partial
triangulation, is generally of infinite rank and contains frozen Jacobian
algebras of triangulations of marked surfaces. The second one, called algebra
of a partial triangulation, is always of (explicit) finite rank and contains
classical Jacobian algebras of triangulations of marked surfaces and Brauer
graph algebras. We classify the partial triangulations, depending on the
complexity of their frozen algebras (some are free of finite rank, some are
lattices over a formal power series ring and most of them are not finitely
generated over their centre). For algebras of partial triangulations, we prove
that they are symmetric when the surface has no boundary. From a more
representation theoretical point of view, we prove that these algebras of
partial triangulations are of tame representation type and we define a
combinatorial operation on partial triangulation, generalizing Kauer moves of
Brauer graphs and flips of triangulations, which give derived equivalences of
the corresponding algebras.


title: Generalized solutions in PDE's and the Burgers' equation

abstract:
  In many situations, the notion of function is not sufficient and it needs to
be extended. A classical way to do this is to introduce the notion of weak
solution; another approach is to use generalized functions. Ultrafunctions are
a particular class of generalized functions that has been previously introduced
and used to define generalized solutions of stationary problems in
[4,7,9,11,12]. In this paper we generalize this notion in order to study also
evolution problems. In particular, we introduce the notion of Generalized
Ultrafunction Solution (GUS) for a large family of PDE's, and we confront it
with classical strong and weak solutions. Moreover, we prove an existence and
uniqueness result of GUS's for a large family of PDE's, including the nonlinear
Schroedinger equation and the nonlinear wave equation. Finally, we study in
detail GUS's of Burgers' equation, proving that (in a precise sense) the GUS's
of this equation provide a description of the phenomenon at microscopic level.


title: An interpretation and understanding of complex modular values

abstract:
  In contrast to that a weak value of an observable is usually divided into
real and imaginary parts, here we show that separation into modulus and
argument is important for modular values. We first show that modular values are
expressed by the average of dynamic phase factors with complex conditional
probabilities. We then relate, using the polar decomposition, the modulus of
the modular value to the relative change in the qubit pointer post-selection
probabilities, and relate the argument of the modular value to the summation of
a geometric phase and an intrinsic phase.


title: Many Languages, One Parser

abstract:
  We train one multilingual model for dependency parsing and use it to parse
sentences in several languages. The parsing model uses (i) multilingual word
clusters and embeddings; (ii) token-level language information; and (iii)
language-specific features (fine-grained POS tags). This input representation
enables the parser not only to parse effectively in multiple languages, but
also to generalize across languages based on linguistic universals and
typological similarities, making it more effective to learn from limited
annotations. Our parser's performance compares favorably to strong baselines in
a range of data scenarios, including when the target language has a large
treebank, a small treebank, or no treebank for training.


title: The local lifting problem for A_4

abstract:
  We solve the local lifting problem for the alternating group A_4, thus
showing that it is a local Oort group. Specifically, if k is an algebraically
closed field of characteristic 2, we prove that every A_4-extension of k[[s]]
lifts to characteristic zero. As a consequence, every A_4-branched cover of
smooth projective curves in characteristic 2 lifts to characteristic zero.


title: Wallach sets and squared Bessel particle systems

abstract:
  We determine the classical and the non-central Wallach sets $W_0$ and $W$ by
classical probabilistic methods. We prove the Mayerhofer conjecture on $W$. We
exploit the fact that $(x_0,\beta)\in W$ if and only if $x_0$ is the starting
point and $2\beta$ is the drift of a squared Bessel matrix process $X_t$ on the
cone $\bar{Sym^+(\mathbf{R},p)}$. Our methods are based on the study of SDEs
for the symmetric polynomials of $X_t$ and for the eigenvalues of $X_t$, i.e.
the squared Bessel particle systems.


title:
A robust high-order Lagrange-projection like scheme with large time
  steps for the isentropic Euler equations

abstract:
  We present an extension to high-order of a first-order Lagrange-projection
like method for the approximation of the Euler equations introduced in Coquel
{\it et al.} (Math. Comput., 79 (2010), pp.~1493--1533). The method is based on
a decomposition between acoustic and transport operators associated to an
implicit-explicit time integration, thus relaxing the constraint of acoustic
waves on the time step. We propose here to use a discontinuous Galerkin method
for the space approximation. Considering the isentropic Euler equations, we
derive conditions to keep positivity of the mean value of density and satisfy
an entropy inequality for the numerical solution in each element of the mesh at
any approximation order in space. These results allow to design limiting
procedures to restore these properties at nodal values within elements.
Numerical experiments support the conclusions of the analysis and highlight
stability and robustness of the present method, though it allows the use of
large time steps.


title:
Comparative Evaluation of Action Recognition Methods via Riemannian
  Manifolds, Fisher Vectors and GMMs: Ideal and Challenging Conditions

abstract:
  We present a comparative evaluation of various techniques for action
recognition while keeping as many variables as possible controlled. We employ
two categories of Riemannian manifolds: symmetric positive definite matrices
and linear subspaces. For both categories we use their corresponding nearest
neighbour classifiers, kernels, and recent kernelised sparse representations.
We compare against traditional action recognition techniques based on Gaussian
mixture models and Fisher vectors (FVs). We evaluate these action recognition
techniques under ideal conditions, as well as their sensitivity in more
challenging conditions (variations in scale and translation). Despite recent
advancements for handling manifolds, manifold based techniques obtain the
lowest performance and their kernel representations are more unstable in the
presence of challenging conditions. The FV approach obtains the highest
accuracy under ideal conditions. Moreover, FV best deals with moderate scale
and translation changes.


title: Design of Geometric Molecular Bonds

abstract:
  An example of a nonspecific molecular bond is the affinity of any positive
charge for any negative charge (like-unlike), or of nonpolar material for
itself when in aqueous solution (like-like). This contrasts specific bonds such
as the affinity of the DNA base A for T, but not for C, G, or another A. Recent
experimental breakthroughs in DNA nanotechnology demonstrate that a particular
nonspecific like-like bond ("blunt-end DNA stacking" that occurs between the
ends of any pair of DNA double-helices) can be used to create specific
"macrobonds" by careful geometric arrangement of many nonspecific blunt ends,
motivating the need for sets of macrobonds that are orthogonal: two macrobonds
not intended to bind should have relatively low binding strength, even when
misaligned.
  To address this need, we introduce geometric orthogonal codes that abstractly
model the engineered DNA macrobonds as two-dimensional binary codewords. While
motivated by completely different applications, geometric orthogonal codes
share similar features to the optical orthogonal codes studied by Chung,
Salehi, and Wei. The main technical difference is the importance of 2D geometry
in defining codeword orthogonality.


title:
Joint Recognition and Segmentation of Actions via Probabilistic
  Integration of Spatio-Temporal Fisher Vectors

abstract:
  We propose a hierarchical approach to multi-action recognition that performs
joint classification and segmentation. A given video (containing several
consecutive actions) is processed via a sequence of overlapping temporal
windows. Each frame in a temporal window is represented through selective
low-level spatio-temporal features which efficiently capture relevant local
dynamics. Features from each window are represented as a Fisher vector, which
captures first and second order statistics. Instead of directly classifying
each Fisher vector, it is converted into a vector of class probabilities. The
final classification decision for each frame is then obtained by integrating
the class probabilities at the frame level, which exploits the overlapping of
the temporal windows. Experiments were performed on two datasets: s-KTH (a
stitched version of the KTH dataset to simulate multi-actions), and the
challenging CMU-MMAC dataset. On s-KTH, the proposed approach achieves an
accuracy of 85.0%, significantly outperforming two recent approaches based on
GMMs and HMMs which obtained 78.3% and 71.2%, respectively. On CMU-MMAC, the
proposed approach achieves an accuracy of 40.9%, outperforming the GMM and HMM
approaches which obtained 33.7% and 38.4%, respectively. Furthermore, the
proposed system is on average 40 times faster than the GMM based approach.


title: Nonparaxial abruptly autofocusing beams

abstract:
  We study nonparaxial autofocusing beams with pre-engineered trajectories. We
consider the case of linearly polarized electric optical beams and examine
their focusing properties such as contrast, beam width, and numerical aperture.
Such beams are associated with larger intensity contrasts, can focus at smaller
distances, and have smaller spot sizes as compared to the paraxial regime.


title: Factoring groups into dense subsets

abstract:
  Let $G $ be a group of cardinality $\kappa>\aleph_0 $ endowed with a topology
$\tau $ such that $|U|=\kappa$ for every non-empty $U\in\tau$ and $\tau$ has a
base of cardinality $\kappa$. We prove that $G$ could be factorized $G=AB$
(i.e. each $g\in G$ has unique representation $g=ab$, $a\in A$, $b\in B$) into
dense subsets $A,B$, $|A|=|B|=\kappa$. We do not know if this statement holds
for $\kappa = \aleph_0$ even if $G$ is a topological group.


title: Modulation Instability and Phase-Shifted Fermi-Pasta-Ulam Recurrence

abstract:
  Instabilities are common phenomena frequently observed in nature, sometimes
leading to unexpected catastrophes and disasters in seemingly normal
conditions. The simplest form of instability in a distributed system is its
response to a harmonic modulation. Such instability has special names in
various branches of physics and is generally known as modulation instability
(MI). The MI is tightly related to Fermi-Pasta-Ulam (FPU) recurrence since
breather solutions of the nonlinear Schr\"odinger equation (NLSE) are known to
accurately describe growth and decay of modulationally unstable waves in
conservative systems. Here, we report theoretical, numerical and experimental
evidence of the effect of dissipation on FPU cycles in a super wave tank,
namely their shift in a determined order. In showing that ideal NLSE breather
solutions can describe such dissipative nonlinear dynamics, our results may
impact the interpretation of a wide range of new physics scenarios.


title:
NIKA 2: next-generation continuum/polarized camera at the IRAM 30 m
  telescope and its prototype

abstract:
  NIKA 2 (New Instrument of Kids Array) is a next generation continuum and
polarized instrument successfully installed in October 2015 at the IRAM 30 m
telescope on Pico-Veleta (Granada, Spain). NIKA 2 is a high resolution
dual-band camera, operating with frequency multiplexed LEKIDs (Lumped Element
Kinetic Inductance Detectors) cooled at 100 mK. Dual color images are obtained
thanks to the simultaneous readout of a 1020 pixels array at 2 mm and 1140 x 2
pixels arrays at 1.15 mm with a final resolution of 18 and 12 arcsec
respectively, and 6.5 arcmin of Field of View (FoV). The two arrays at 1.15 mm
allow us to measure the linear polarization of the incoming light. This will
place NIKA 2 as an instrument of choice to study the role of magnetic fields in
the star formation process. The NIKA experiment, a prototype for NIKA 2 with a
reduced number of detectors (about 400 LEKIDs) and FoV (1.8 arcmin), has been
successfully operated at the IRAM 30 telescope in several open observational
campaigns. The performance of the NIKA 2 polarization setup has been
successfully validated with the NIKA prototype.


title: Mittag-Leffler L\'evy Processes

abstract:
  In this article, we introduce Mittag-Leffler L\'evy process and provide two
alternative representations of this process. First, in terms of Laplace
transform of the marginal densities and next as a subordinated stochastic
process. Both these representations are useful in analyzing the properties of
the process. Since integer order moments for this process are not finite, we
obtain fractional order moments. Its density function and corresponding L\'evy
measure density is also obtained. Further, heavy tailed behavior of densities
and stochastic self-similarity of the process is demonstrated. Our results
generalize and complement the results available on Mittag-Leffler distribution
in several directions.


title: SALT observation of X-ray pulse reprocessing in 4U 1626-67

abstract:
  We investigate optical reprocessing of X-rays in the LMXB pulsar 4U 1626-67
in its current spin-up phase using observations with Southern African Large
Telescope (SALT), near-simultaneous observations with Swift-XRT and
non-simultaneous RXTE-PCA observations and present the results of timing
analysis. Using SALT observations carried out on 5th and 6th March, 2014, we
detect some interesting reprocessing signatures. We detect a weak optical Quasi
Periodic Oscillation (QPO) in the power density spectrum on March 5th at 48 mHz
with a fractional rms of 3.3% in spite of the fact that source shows no
corresponding X-ray QPO in the spin-up phase. In the light curve obtained on
March 5th, we detect a coherent pulsation at the spin period of ~7.677 s. A
previously known, slightly down-shifted side-band is also detected at 129.92
mHz. The frequency spacing between main pulse and this side-band is different
from earlier observations, though the statistical significance of the
difference is limited. The light curve of 6th March displays short time-scale
variability in the form of flares on timescales of a few minutes. Folded pulse
profiles resulting from data of this night show an interesting trend of pulse
peak drifting. This drift could be due to i) rapid changes in the reprocessing
agent, like orbital motion of an accretion disk warp around the neutron star or
ii) intrinsic pulse phase changes in X-rays. We also examine some X-ray light
curves obtained with RXTE-PCA during 2008-2010 for pulse shape changes in short
time scales during X-ray flares.


title: Appearance Based Robot and Human Activity Recognition System

abstract:
  In this work, we present an appearance based human activity recognition
system. It uses background modeling to segment the foreground object and
extracts useful discriminative features for representing activities performed
by humans and robots. Subspace based method like principal component analysis
is used to extract low dimensional features from large voluminous activity
images. These low dimensional features are then used to classify an activity.
An apparatus is designed using a webcam, which watches a robot replicating a
human fall under indoor environment. In this apparatus, a robot performs
various activities (like walking, bending, moving arms) replicating humans,
which also includes a sudden fall. Experimental results on robot performing
various activities and standard human activity recognition databases show the
efficacy of our proposed method.


title: Charge Qubit-Atom Hybrid

abstract:
  We investigate a novel hybrid system of a superconducting charge qubit
interacting directly with a single neutral atom via electric dipole coupling.
Interfacing of the macroscopic superconducting circuit with the microscopic
atomic system is accomplished by varying the gate capacitance of the charge
qubit. To achieve strong interaction, we employ two Rydberg states with an
electric-dipole allowed transition, which alters the polarizability of the
dielectric medium of the gate capacitor. Sweeping the gate voltage with
different rates leads to a precise control of hybrid quantum states.
Furthermore, we show a possible implementation of a universal two-qubit gate.


title:
The Degenerate Eisenstein Series Attached to the Heisenberg Parabolic
  Subgroups of Quasi-Split Forms of $Spin_8$

abstract:
  In previews works, joint with N. Gurevitch, a family of Rankin-Selberg
integrals were shown to represent the twisted standard $\mathcal{L}$-function
$\mathcal{L}\left(s,\pi,\chi,\mathfrak{st}\right)$ of a cuspidal representation
$ \pi$ of the exceptional group of type $G_2$. This integral representation
binds the analytic behavior of this $\mathcal{L}$-functions with that of a
degenerate Eisenstein series defined over the family of quasi-split forms of
$Spin_8$ associated to an induction from a character on the Heisenberg
parabolic subgroup.
  This paper is divided into two parts. In part 1 we study the poles of this
degenerate Eisenstein series in the right half plane $\mathfrak{Re}(s)>0$. In
part 2 we use the results of part 1 to give a criterion for $\pi$ to be a {\bf
CAP} representation with respect to the Borel subgroup in terms of poles of
$\mathcal{L}\left(s,\pi,\chi,\mathfrak{st}\right)$. We also settle a conjecture
of J. Hundley and D. Ginzburg and prove a few results relating the analytic
behavior of $\mathcal{L}\left(s,\pi,\chi,\mathfrak{st}\right)$ and the set of
Fourier coefficients supported by $\pi$.


title:
Solvent fluctuations induce non-Markovian kinetics in hydrophobic
  pocket-ligand binding

abstract:
  We investigate the impact of water fluctuations on the key-lock association
kinetics of a hydrophobic ligand (key) binding to a hydrophobic pocket (lock)
by means of a minimalistic stochastic model system. It describes the collective
hydration behavior of the pocket by bimodal fluctuations of a water-pocket
interface that dynamically couples to the diffusive motion of the approaching
ligand via the hydrophobic interaction. This leads to a set of overdamped
Langevin equations in 2D-coordinate-space, that is Markovian in each dimension.
Numerical simulations demonstrate locally increased friction of the ligand,
decelerated binding kinetics, and local non-Markovian (memory) effects in the
ligand's reaction coordinate as found previously in explicit-water molecular
dynamics studies of model hydrophobic pocket-ligand binding [1,2]. Our
minimalistic model elucidates the origin of effectively enhanced friction in
the process that can be traced back to long-time decays in the
force-autocorrelation function induced by the effective, spatially fluctuating
pocket-ligand interaction. Furthermore, we construct a generalized 1D-Langevin
description including a spatially local memory function that enables further
interpretation and a semi-analytical quantification of the results of the
coupled 2D-system.


title:
Evolutionary dynamics of selfish DNA generates pseudo-linguistic
  features of genomes

abstract:
  Since the sequencing of large genomes, many statistical features of their
sequences have been found. One intriguing feature is that certain subsequences
are much more abundant than others. In fact, abundances of subsequences of a
given length are distributed with a scale-free power-law tail, resembling
properties of human texts, such as the Zipf's law. Despite recent efforts, the
understanding of this phenomenon is still lacking. Here we find that selfish
DNA elements, such as those belonging to the Alu family of repeats, dominate
the power-law tail. Interestingly, for the Alu elements the power-law exponent
increases with the length of the considered subsequences. Motivated by these
observations, we develop a model of selfish DNA expansion. The predictions of
this model qualitatively and quantitatively agree with the empirical
observations. This allows us to estimate parameters for the process of selfish
DNA spreading in a genome during its evolution. The obtained results shed light
on how evolution of selfish DNA elements shapes non-trivial statistical
properties of genomes.


title: Generalized Pickands constants and stationary max-stable processes

abstract:
  Pickands constants play a crucial role in the asymptotic theory of Gaussian
processes. They are commonly defined as the limits of a sequence of
expectations involving fractional Brownian motions and, as such, their exact
value is often unknown. Recently, Dieker and Yakir (2014) derived a novel
representation of Pickands constant as a simple expected value that does not
involve a limit operation. In this paper we show that the notion of Pickands
constants and their corresponding Dieker-Yakir representations can be extended
to a large class of stochastic processes, including general Gaussian and L\'evy
processes. We furthermore provide a link to spatial extreme value theory and
show that Pickands-type constants coincide with certain constants arising in
the study of max-stable processes with mixed moving maxima representations.


title: Connectivity Scaling Laws in Wireless Networks

abstract:
  We present scaling laws that dictate both local and global connectivity
properties of bounded wireless networks. These laws are defined with respect to
the key system parameters of per-node transmit power and the number of antennas
exploited for diversity coding and/or beamforming at each node. We demonstrate
that the local probability of connectivity scales like $\mathcal{O}(z^\mathcal
C)$ in these parameters, where $\mathcal C$ is the ratio of the dimension of
the network domain to the path loss exponent, thus enabling efficient boundary
effect mitigation and network topology control.


title:
High spatial resolution imaging of SO and H2CO in AB Auriga: the first
  SO image in a transitional disk

abstract:
  Transitional disks are structures of dust and gas around young stars with
large inner cavities in which planet formation may occur. Lopsided dust
distributions are observed in the dust continuum emission at millimeter
wavelengths. These asymmetrical structures can be explained as the result of an
enhanced gas density vortex where the dust is trapped potentially promoting the
rapid growth to the planetesimal scale. AB Aur hosts a transitional disk with a
clear horseshoe morphology which strongly suggests the presence of a dust trap.
Our goal is to investigate its formation and the possible effects on the gas
chemistry. We used the NOEMA interferometer to image the 1mm continuum dust
emission and the 13CO J=2->1, C18O J=2->1, SO J=56->45 and H2CO J=303->202
rotational lines. Line integrated intensity ratio images are built to
investigate the chemical changes within the disk. We have used a single point
(n,T) chemical model to investigate the lifetime of gaseous CO, H2CO and SO in
the dust trap. Our model shows that for densities >10^7 cm^-3, the SO molecules
are depleted (directly frozen or converted into SO2 and then frozen out) in
less than 0.1 Myr. The lower SO abundance towards the dust trap could indicate
that a larger fraction of the gas is in a high density environment. Gas
dynamics, grain growth and gas chemistry are coupled in the planet formation
process. Because of the strong dependence of SO abundance on the gas density,
the sulfur chemistry can be used as a chemical diagnostic to detect the
birthsites of future planets. However, the large uncertainties inherent to
chemical models and the limited knowledge of the disk physical structure and
initial conditions are important drawbacks.


title:
FPGA Based Implementation of Deep Neural Networks Using On-chip Memory
  Only

abstract:
  Deep neural networks (DNNs) demand a very large amount of computation and
weight storage, and thus efficient implementation using special purpose
hardware is highly desired. In this work, we have developed an FPGA based
fixed-point DNN system using only on-chip memory not to access external DRAM.
The execution time and energy consumption of the developed system is compared
with a GPU based implementation. Since the capacity of memory in FPGA is
limited, only 3-bit weights are used for this implementation, and training
based fixed-point weight optimization is employed. The implementation using
Xilinx XC7Z045 is tested for the MNIST handwritten digit recognition benchmark
and a phoneme recognition task on TIMIT corpus. The obtained speed is about one
quarter of a GPU based implementation and much better than that of a PC based
one. The power consumption is less than 5 Watt at the full speed operation
resulting in much higher efficiency compared to GPU based systems.


title: The intricate labyrinth of Collatz sequences

abstract:
  In a previous article, we reduced the unsolved problem of the convergence of
Collatz sequences, to convergence of Collatz sequences of odd numbers, that are
divisible by 3. In this article, we further reduce this set to odd numbers that
are congruent to 21 mod 24. We also show that either the Collatz sequence of a
given odd number or an equivalent Collatz sequence reverses to a multiple of 3.
Moreover, we construct a network composed of Collatz sequences of all odd
numbers.


title: Quadratic Modules, C*-Algebras, and Free Convexity

abstract:
  Given a quadratic module, we construct its universal C*-algebra, and then use
methods and notions from the theory of C*-algebras to study the quadratic
module. We define residually finite-dimensional quadratic modules, and
characterize them in various ways, in particular via a Positivstellensatz. We
give unified proofs for several existing strong Positivstellens\"atze, and
prove some new ones. Our approach also leads naturally to interesting new
examples in free convexity. We show that the usual notion of a free convex hull
is not able to detect residual finite-dimensionality. We thus propose a new
notion of free convexity, which is coordinate-free. We characterize
semialgebraicity of free convex hulls of semialgebraic sets, and show that they
are not always semialgebraic, even at scalar level. This also shows that the
membership problem for quadratic modules has a negative answer in the
non-commutative setup.


title:
Distributed Power Allocation and Channel Access Probability Assignment
  for Cognitive Radio

abstract:
  In this paper, we present a framework for distributively optimizing the
transmission strategies of secondary users in an ad hoc cognitive radio
network. In particular, the proposed approach allows secondary users to set
their transmit powers and channel access probabilities such that, on average,
the quality of service of both the primary and secondary networks are
satisfied. The system under consideration assumes several primary and secondary
transceiver pairs and assumes no cooperation or information exchange between
neither primary and secondary users nor among secondary users. The outage
probability, and consequently the connection probability, is derived for the
system and is used in defining a new performance metric in the optimization
problem using tools from stochastic geometry. We refer to this metric as the
spatial density of successful transmission. We corroborate our derivations
through numerical evaluations. We further demonstrate that even in the absence
of any form of cooperation, an acceptable quality of service can be attained in
the cognitive radio environment.


title: A Green Enterprise Computing Architecture for Developing Countries

abstract:
  Developing countries often have access to limited energy resources, which
frequently results in power cuts and failures. During these power cuts,
enterprises rely on backup sources for power such as uninterruptible power
supplies (UPS) and electric generators. This paper proposes AnywareDC, an
architecture that builds on the recent work on Anyware to reduce energy
utilization in the presence of such intermittent power supplies. Anyware
reduces energy usage by providing enterprise users laptops instead of desktops,
while maintaining performance using a central compute cluster. Our basic
insight is that in the presence of power cuts, only the routers and the cluster
needs to be provided power: the laptops can continue to run on their own
batteries. This reduces both energy usage and UPS load allowing it to supply
power for longer, thus also saving generator fuel costs. Simulations show that
this architecture reduces energy usage by up to 80% compared to one not using
Anyware, and by up to 20% compared to Anyware.


title:
Frequency dependent visco-elastic properties of a water nanomeniscus :
  an AFM study in Force Feedback Mode

abstract:
  Recently, using an Atomic Force Microscope and a single cantilever excited at
different frequencies it was shown that water nanomeniscus can exhibit a
transition in mechanical responses when submitted to stimuli above few tens of
kHz. The use of a single cantilever to explore phenomena at frequencies far
from the cantilever resonance frequency is not a common and well-established
strategy, and because water meniscus are ubiquitous in nature, we have also
studied the water meniscus mechanical response, the stiffness G' (N/m) and the
dissipation G"(kg/s), as a function of frequency by using cantilevers with
different resonance frequencies. These results, based on classic dynamical AFM
technics, confirm the anomalous mechanical response of water nanomeniscus when
stimulated at frequencies high enough.


title:
A Hydrodynamic Approach to the Study of Anisotropic Instabilities in
  Dissipative Relativistic Plasmas

abstract:
  We develop a purely hydrodynamic formalism to describe collisional,
anisotropic instabilities in a relativistic plasma, that are usually described
with kinetic theory tools. Our main motivation is the fact that coarse-grained
models of high particle number systems give more clear and comprehensive
physical descriptions of those systems than purely kinetic approaches, and can
be more easily tested experimentally as well as numerically. In particular, we
aim at developing a theory that describes both a background non-equilibrium
fluid configurations and its perturbations, to be able to account for the
backreaction of the latter on the former. Our system of equations includes the
usual conservation laws for the energy-momentum tensor and for the electric
current, and the equations for two new tensors that encode the information
about dissipation. To make contact with kinetic theory, we write the different
tensors as the moments of a non-equilibrium one-particle distribution function
(1pdf) which, for illustrative purposes, we take in the form of a Grad-like
ansatz. Although this choice limits the applicability of the formalism to
states not far from equilibrium, it retains the main features of the underlying
kinetic theory. We assume the validity of the Vlasov-Boltzmann equation, with a
collision integral given by the Anderson-Witting prescription, which is more
suitable for highly relativistic systems than Marle's (or Bhatnagar, Gross and
Krook) form, and derive the conservation laws by taking its corresponding
moments. We apply our developments to study the emergence of instabilities in
an anisotropic, but axially symmetric background. For small departures of
isotropy we find the dispersion relation for normal modes, which admit unstable
solutions for a wide range of values of the parameter space.


title: Connectivity of Cooperative Ad hoc Networks

abstract:
  The connectivity properties of ad hoc networks have been extensively studied
over the past few years, from local observables, to global network properties.
In this paper we introduce a novel layer of network dynamics which lives and
evolves on top of the ad hoc network. Nodes are assumed selfish and a
snow-drift type game is defined dictating the way nodes decide to allocate
their cooperative resource efforts towards other nodes in the network. The
dynamics are strongly coupled with the physical network causing the cooperation
network topology to converge towards a stable equilibrium state, a global
maximum of the total pay-off. We study this convergence from a connectivity
perspective and analyse the inherent parameter dependence. Moreover, we show
that direct reciprocity can be an efficient incentive to promote cooperation
within the network and discuss the analogies between our simple yet tractable
framework with D2D proximity based services such as LTE-Direct. We argue that
cooperative network dynamics have many application in ICT, not just ad hoc
networks, and similar models as the one described herein can be devised and
studied in their own right.


title: Experimental Test of Hyper-Complex Quantum Theories

abstract:
  In standard quantum mechanics, complex numbers are used to describe the
wavefunction. Although complex numbers have proven sufficient to predict the
results of existing experiments, there is no apparent theoretical reason to
choose them over real numbers or generalizations of complex numbers, i.e.
hyper-complex numbers. Experiments performed to date have proven that real
numbers are insufficient, but whether or not hyper-complex numbers are required
remains an open question. Quantum theories based on hyper-complex numbers are
one example of a post-quantum theory, which must be put on a firm experimental
foundation. Here we experimentally probe hyper-complex quantum theories, by
studying one of their deviations from complex quantum theory: the
non-commutativity of phases. We do so by passing single photons through a
Sagnac interferometer containing two physically different phases, having
refractive indices of opposite sign. By showing that the phases commute with
high precision, we place limits on a particular prediction of hyper-complex
quantum theories.


title: Self-Transfer Learning for Fully Weakly Supervised Object Localization

abstract:
  Recent advances of deep learning have achieved remarkable performances in
various challenging computer vision tasks. Especially in object localization,
deep convolutional neural networks outperform traditional approaches based on
extraction of data/task-driven features instead of hand-crafted features.
Although location information of region-of-interests (ROIs) gives good prior
for object localization, it requires heavy annotation efforts from human
resources. Thus a weakly supervised framework for object localization is
introduced. The term "weakly" means that this framework only uses image-level
labeled datasets to train a network. With the help of transfer learning which
adopts weight parameters of a pre-trained network, the weakly supervised
learning framework for object localization performs well because the
pre-trained network already has well-trained class-specific features. However,
those approaches cannot be used for some applications which do not have
pre-trained networks or well-localized large scale images. Medical image
analysis is a representative among those applications because it is impossible
to obtain such pre-trained networks. In this work, we present a "fully" weakly
supervised framework for object localization ("semi"-weakly is the counterpart
which uses pre-trained filters for weakly supervised localization) named as
self-transfer learning (STL). It jointly optimizes both classification and
localization networks simultaneously. By controlling a supervision level of the
localization network, STL helps the localization network focus on correct ROIs
without any types of priors. We evaluate the proposed STL framework using two
medical image datasets, chest X-rays and mammograms, and achieve signiticantly
better localization performance compared to previous weakly supervised
approaches.


title: Spectral deferred corrections with fast-wave slow-wave splitting

abstract:
  The paper investigates a variant of semi-implicit spectral deferred
corrections (SISDC) in which the stiff, fast dynamics correspond to fast
propagating waves ("fast-wave slow-wave problem"). We show that for a scalar
test problem with two imaginary eigenvalues $i \lambda_{fast}$, $i
\lambda_{slow}$, having $\Delta t \left(\left| \lambda_{fast} \right| + \left|
\lambda_{slow} \right| \right) < 1$ is sufficient for the fast-wave slow-wave
SDC (FWSW-SDC) iteration to converge and that in the limit of infinitely fast
waves the convergence rate of the non-split version is retained. Stability
function and discrete dispersion relation are derived and show that the method
is stable for essentially arbitrary fast-wave CFL numbers as long as the slow
dynamics are resolved. The method causes little numerical diffusion and its
semi-discrete phase speed is accurate also for large wave number modes.
Performance is studied for an acoustic-advection problem and for the linearised
Boussinesq equations, describing compressible, stratified flow. FWSW-SDC is
compared to a diagonally implicit Runge-Kutta (DIRK) and IMEX Runge-Kutta
(IMEX) method and found to be competitive in terms of both accuracy and cost.


title: Covers of the arithmetic site

abstract:
  We give an explicit description of the Barr- and Diaconescu covers of the
arithmetic site, which are relevant to cohomology. Further, we construct the
arithmetic site as the commutative shadow of a non-commutative topological
space.


title: Fuzzy Object-Oriented Dynamic Networks. II

abstract:
  This article generalizes object-oriented dynamic networks to the fuzzy case,
which allows one to represent knowledge on objects and classes of objects that
are fuzzy by nature and also to model their changes in time. Within the
framework of the approach described, a mechanism is proposed that makes it
possible to acquire new knowledge on the basis of basic knowledge and
considerably differs from well-known methods used in existing models of
knowledge representation. The approach is illustrated by an example of
construction of a concrete fuzzy object-oriented dynamic network.


title:
Online and Global Network Optimization: Towards the Next-Generation of
  Routing Platforms

abstract:
  The computation power of SDN controllers fosters the development of a new
generation of control plane that uses compute-intensive operations to automate
and optimize the network configuration across layers. From now on, cutting-edge
optimization and machine learning algorithms can be used to control networks in
real-time. This formidable opportunity transforms the way routing systems
should be conceived and designed. This paper presents a candidate architecture
for the next generation of routing platforms built on three main pillars for
admission control, re-routing and monitoring that would have not been possible
in legacy control planes.


title: On algebraic integers in short intervals and near smooth curves

abstract:
  In 1970 A. Baker and W. Schmidt introduced regular systems of numbers and
vectors, showing that the set of real algebraic numbers forms a regular system
on any fixed interval. This fact was used to prove several important results in
the metric theory of transcendental numbers. In this paper the concept of a
regular system is applied to the set of algebraic integers $\alpha$ of height
$\leq Q$ in intervals of length depending on $Q$.


title:
On points with algebraically conjugate coordinates close to smooth
  curves

abstract:
  We show that for any sufficiently large integer $Q$ and a real
$0\leq\lambda\leq\frac34$ there exists a value $c(n,f,J)>0$ such that all
strips $L(Q,\lambda)=\{(x,y):|y-f(x)|<Q^{-\lambda}, x\in J=[a,b]\}$ contain at
least $c(n, f, J)Q^{n+1-\lambda}$ points $\bar{\gamma}=(\alpha,\beta)$ with
algebraically conjugate coordinates. We consider points $\bar{\gamma}$ such
that the minimal polynomial $P(x)$ of $\alpha,\beta$ is of degree $\deg P\leq
n,\ n\ge 2$, and height $H(P)\leq Q$. The proof is based on a metric theorem on
the measure of the set of vectors $(x,y)$ lying in a rectangle $\Pi$ of
dimensions $Q^{-s_1}\times Q^{-s_2}$ with $|P(x)|, |P(y)|$ bounded from above
and $|P'(x)|,|P'(y)|$ bounded from below, where $P(x)$ is a polynomial of
degree $\deg P\leq n$ and height $H(P)\leq Q$. This theorem is a generalization
of a result obtained by V. Bernik, F. G\"otze and O. Kukso for
$s_1=s_2=\frac12$ and $\lambda = \frac12$.


title:
Magnetic anisotropy in the frustrated spin chain compound
  $\beta$-TeVO$_4$

abstract:
  Isotropic and anisotropic magnetic behavior of the frustrated spin chain
compound $\beta$-TeVO$_4$ is reported. Three magnetic transitions observed in
zero magnetic field are tracked in fields applied along different
crystallographic directions using magnetization, heat capacity, and
magnetostriction measurements. Qualitatively different temperature-field
diagrams are obtained below 10 T for the field applied along $a$ or $b$ and
along $c$, respectively. In contrast, a nearly isotropic high-field phase
emerges above 18 T and persists up to the saturation that occurs around 22.5 T.
Upon cooling in low fields, the transitions at $T_{\rm N1}$ and $T_{\rm N2}$
toward the spin-density-wave and stripe phases are of the second order, whereas
the transition at $T_{\rm N3}$ toward the helical state is of the first order
and entails a lattice component. Our microscopic analysis identifies frustrated
$J_1-J_2$ spin chains with a sizable antiferromagnetic interchain coupling in
the $bc$ plane and ferromagnetic couplings along the $a$ direction. The
competition between these ferromagnetic interchain couplings and the helical
order within the chain underlies the incommensurate order along the
$a$-direction, as observed experimentally. Although a helical state is
triggered by the competition between $J_1$ and $J_2$ within the chain, the
plane of the helix is not uniquely defined because of competing magnetic
anisotropies. Using high-resolution synchrotron diffraction and $^{125}$Te
nuclear magnetic resonance, we also demonstrate that the crystal structure of
$\beta$-TeVO$_4$ does not change down to 10 K, and the orbital state of
V$^{4+}$ is preserved.


title:
Charged-particle distributions in $\sqrt{s}=13$ TeV $pp$ interactions
  measured with the ATLAS detector at the LHC

abstract:
  Charged-particle distributions are measured in proton-proton collisions at a
centre-of-mass energy of 13 TeV, using a data sample of nearly 9 million
events, corresponding to an integrated luminosity of 170 $\mu$b$^{-1}$,
recorded by the ATLAS detector during a special Large Hadron Collider fill. The
charged-particle multiplicity, its dependence on transverse momentum and
pseudorapidity and the dependence of the mean transverse momentum on the
charged-particle multiplicity are presented. The measurements are performed
with charged particles with transverse momentum greater than 500 MeV and
absolute pseudorapidity less than 2.5, in events with at least one charged
particle satisfying these kinematic requirements. Additional measurements in a
reduced phase space with absolute pseudorapidity less than 0.8 are also
presented, in order to compare with other experiments. The results are
corrected for detector effects, presented as particle-level distributions and
are compared to the predictions of various Monte Carlo event generators.


title: Arithmetic properties of sparse subsets of $\mathbb{Z}^n$

abstract:
  Arithmetic progressions of length $3$ may be found in compact subsets of the
reals that satisfy certain Fourier -- as well as Hausdorff -- dimensional
requirements. It has been shown that a very similar result holds in the
integers under analogous conditions, with Fourier dimension being replaced by
the decay of a discrete Fourier transform. In this paper we make this
correspondence more precise, using a well-known construction by Salem.
Specifically, we show that a subset of the integers can be mapped to a compact
subset of the continuum in a way which preserves certain dimensional properties
as well as arithmetic progressions of arbitrary length. The higher-dimensional
version of this construction is then used to show that certain parallelogram
configurations must exist in sparse subsets of $\mathbb{Z}^n$ satisfying
appropriate density and Fourier-decay conditions.


title:
A Generalised Quantifier Theory of Natural Language in Categorical
  Compositional Distributional Semantics with Bialgebras

abstract:
  Categorical compositional distributional semantics is a model of natural
language; it combines the statistical vector space models of words with the
compositional models of grammar. We formalise in this model the generalised
quantifier theory of natural language, due to Barwise and Cooper. The
underlying setting is a compact closed category with bialgebras. We start from
a generative grammar formalisation and develop an abstract categorical
compositional semantics for it, then instantiate the abstract setting to sets
and relations and to finite dimensional vector spaces and linear maps. We prove
the equivalence of the relational instantiation to the truth theoretic
semantics of generalised quantifiers. The vector space instantiation formalises
the statistical usages of words and enables us to, for the first time, reason
about quantified phrases and sentences compositionally in distributional
semantics.


title:
Isogeometric preconditioners based on fast solvers for the Sylvester
  equation

abstract:
  We consider large linear systems arising from the isogeometric discretization
of the Poisson problem on a single-patch domain. The numerical solution of such
systems is considered a challenging task, particularly when the degree of the
splines employed as basis functions is high. We consider a preconditioning
strategy which is based on the solution of a Sylvester-like equation at each
step of an iterative solver. We show that this strategy, which fully exploits
the tensor structure that underlies isogeometric problems, is robust with
respect to both mesh size and spline degree, although it may suffer from the
presence of complicated geometry or coefficients. We consider two popular
solvers for the Sylvester equation, a direct one and an iterative one, and we
discuss in detail their implementation and efficiency for 2D and 3D problems on
single-patch or conforming multi-patch NURBS geometries. Numerical experiments
for problems with different domain geometries are presented, which demonstrate
the potential of this approach.


title:
Pfaffian equations and contiguity relations of the hypergeometric
  function of type $(k+1, k+n+2)$ and their applications

abstract:
  We study the structures of Pfaffian equations and contiguity relations of the
hypergeometric function of type $(k+1,k+n+2)$ by using twisted cohomology
groups and the intersection form on them. We apply our results to algebraic
statistics; numerical evaluation of the normalizing constants of two way
contingency tables with fixed marginal sums.


title:
Order O(1) algorithm for first-principles transient current through open
  quantum systems

abstract:
  In the study the response time of ultrafast transistor and peak transient
current to prevent melt down of nano-chips, the first principles transient
current calculation plays an essential role in nanoelectronics. The first
principles calculation of transient current through nano-devices for a period
of time T is known to be extremely time consuming with the best scaling TN^3
where N is the dimension of the device. In this work, we provide an order O(1)
algorithm that reduces the computational complexity to T^0 N^3 for large
systems. Benchmark calculation has been done on graphene nanoribbons with N =
10^4 confirming the O(1) scaling. This breakthrough allows us to tackle many
large scale transient problems including magnetic tunneling junctions and
ferroelectric tunneling junctions that cannot be touched before.


title:
Sequential electron transport and vibrational excitations in an organic
  molecule coupled to few-kayer graphene electrodes

abstract:
  Graphene electrodes are promising candidates to improve reproducibility and
stability in molecular electronics through new electrode-molecule anchoring
strategies. Here we report sequential electron transport in few-layer graphene
transistors containing individual curcuminoid-based molecules anchored to the
electrodes via pi-pi orbital bonding. We show the coexistence of inelastic
co-tunneling excitations with single-electron transport physics owing to an
intermediate molecule-electrode coupling; we argue that an intermediate
electron-phonon coupling is the origin of these vibrational-assisted
excitations. These experimental observations are complemented with density
functional theory calculations to model electron transport and the interaction
between electrons and vibrational modes of the curcuminoid molecule. We find
that the calculated vibrational modes of the molecule are in agreement with the
experimentally observed excitations.