title: Logical and inequality based contextuality for qudits

abstract:
  In this work we present a generalization of the recently developed Hardy-like
logical proof of contextuality and of the so-called KCBS contextuality
inequality for any qudit of dimension greater than three. Our approach uses
compatibility graphs that can only be satisfied by qudits. We find a
construction for states and measurements that satisfy these graphs and
demonstrate both logical and inequality based contextuality for qudits.
Interestingly, the quantum violation of the inequality is constant as dimension
increases. We also discuss the issue of imprecision in experimental
implementations of contextuality tests and a way of addressing this problem
using the notion of ontological faithfulness.


title: Hypergroups arising from characters of a compact group and its subgroup

abstract:
  The purpose of the present paper is to investigate a hypergroup arising from
irreducible characters of a compact group G and a closed subgroup of G with
finite index. The convolution of this hypergroup is introduced by inducing
irreducible representations and by restricting irreducible representations. The
method of proof relies on character formulae of induced representations of
compact groups and of Frobenius' reciprocity theorem.


title:
Simultaneous identification of specifically interacting paralogs and
  inter-protein contacts by Direct-Coupling Analysis

abstract:
  Understanding protein-protein interactions is central to our understanding of
almost all complex biological processes. Computational tools exploiting rapidly
growing genomic databases to characterize protein-protein interactions are
urgently needed. Such methods should connect multiple scales from evolutionary
conserved interactions between families of homologous proteins, over the
identification of specifically interacting proteins in the case of multiple
paralogs inside a species, down to the prediction of residues being in physical
contact across interaction interfaces. Statistical inference methods detecting
residue-residue coevolution have recently triggered considerable progress in
using sequence data for quaternary protein structure prediction; they require,
however, large joint alignments of homologous protein pairs known to interact.
The generation of such alignments is a complex computational task on its own;
application of coevolutionary modeling has in turn been restricted to proteins
without paralogs, or to bacterial systems with the corresponding coding genes
being co-localized in operons. Here we show that the Direct-Coupling Analysis
of residue coevolution can be extended to connect the different scales, and
simultaneously to match interacting paralogs, to identify inter-protein
residue-residue contacts and to discriminate interacting from noninteracting
families in a multiprotein system. Our results extend the potential
applications of coevolutionary analysis far beyond cases treatable so far.


title: Fast Graph-Based Object Segmentation for RGB-D Images

abstract:
  Object segmentation is an important capability for robotic systems, in
particular for grasping. We present a graph- based approach for the
segmentation of simple objects from RGB-D images. We are interested in
segmenting objects with large variety in appearance, from lack of texture to
strong textures, for the task of robotic grasping. The algorithm does not rely
on image features or machine learning. We propose a modified Canny edge
detector for extracting robust edges by using depth information and two simple
cost functions for combining color and depth cues. The cost functions are used
to build an undirected graph, which is partitioned using the concept of
internal and external differences between graph regions. The partitioning is
fast with O(NlogN) complexity. We also discuss ways to deal with missing depth
information. We test the approach on different publicly available RGB-D object
datasets, such as the Rutgers APC RGB-D dataset and the RGB-D Object Dataset,
and compare the results with other existing methods.


title: Aberration-free volumetric high-speed imaging of in vivo retina

abstract:
  Research and medicine rely on non-invasive optical techniques to image living
tissue with high resolution in space and time. But so far a single data
acquisition could not provide entirely diffraction-limited tomographic volumes
of rapidly moving or changing targets, which additionally becomes increasingly
difficult in the presence of aberrations, e.g., when imaging retina in vivo. We
show, that a simple interferometric setup based on parallelized optical
coherence tomography acquires volumetric data with 10 billion voxels per
second, exceeding previous imaging speeds by an order of magnitude. This allows
us to computationally obtain and correct defocus and aberrations resulting in
entirely diffraction-limited volumes. As demonstration, we imaged living human
retina with clearly visible nerve fiber layer, small capillary networks, and
photoreceptor cells, but the technique is also applicable to obtain
phase-sensitive volumes of other scattering structures at unprecedented
acquisition speeds.


title:
Chiral expansion and Macdonald deformation of two-dimensional Yang-Mills
  theory

abstract:
  We derive the analog of the large $N$ Gross-Taylor holomorphic string
expansion for the refinement of $q$-deformed $U(N)$ Yang-Mills theory on a
compact oriented Riemann surface. The derivation combines Schur-Weyl duality
for quantum groups with the Etingof-Kirillov theory of generalized quantum
characters which are related to Macdonald polynomials. In the unrefined limit
we reproduce the chiral expansion of $q$-deformed Yang-Mills theory derived by
de Haro, Ramgoolam and Torrielli. In the classical limit $q=1$, the expansion
defines a new $\beta$-deformation of Hurwitz theory wherein the refined
partition function is a generating function for certain parameterized Euler
characters, which reduce in the unrefined limit $\beta=1$ to the orbifold Euler
characteristics of Hurwitz spaces of holomorphic maps. We discuss the
geometrical meaning of our expansions in relation to quantum spectral curves
and $\beta$-ensembles of matrix models arising in refined topological string
theory.


title: The gonality sequence of complete graphs

abstract:
  The gonality sequence $(\gamma_r)_{r\geq1}$ of a finite graph / metric graph
/ algebraic curve comprises the minimal degrees $\gamma_r$ of linear systems of
rank $r$. For the complete graph $K_d$, we show that $\gamma_r = kd - h$ if
$r<g=\frac{(d-1)(d-2)}{2}$, where $k$ and $h$ are the uniquely determined
integers such that $r = \frac{k(k+3)}{2} - h$ with $1\leq k\leq d-3$ and $0
\leq h \leq k $. This shows that the graph $K_d$ has the gonality sequence of a
smooth plane curve of degree $d$. The same result holds for the corresponding
metric graphs.


title: The Goldreich-Schubert-Fricke instability in stellar radiative zones

abstract:
  The Goldreich-Schubert-Fricke (GSF) instability is a rotational instability
that is thought to contribute to the transfer of angular momentum in
differentially rotating stars. It has been included in recent codes of stellar
evolution in a diffusion-like approximation, under the assumption that the
kinematic viscosity $\nu$ is unimportant for the development of the
instability. As noted previously by other authors, for most stellar
applications this may not be a valid approximation. We discuss this issue in
detail, solving the dispersion relation of the perturbed modes for realistic
values of $\nu$ in the bulk of the radiative zone of the Sun and of three red
giant stars at various evolutionary stages. We find that the GSF instability is
triggered only in layers of extremely strong shear. In a simple case study, we
also investigate the effect of a small deviation from axisymmetry or a small
background magnetic field. We find that, like the viscosity, these have a
stabilising effect. We conclude that this instability is probably far less
efficient in transporting angular momentum than is often assumed, and may not
even be present.


title:
Nonparametric homogeneity tests and multiple change-point estimation for
  analyzing large Hi-C data matrices

abstract:
  We propose a novel nonparametric approach for estimating the location of
block boundaries (change-points) of non-overlapping blocks in a random
symmetric matrix which consists of random variables having their distribution
changing from one block to the other. Our method is based on a nonparametric
two-sample homogeneity test for matrices that we extend to the more general
case of several groups. We first provide some theoretical results for the two
associated test statistics and we explain how to derive change-point location
estimators. Then, some numerical experiments are given in order to support our
claims. Finally, our approach is applied to Hi-C data which are used in
molecular biology for better understanding the influence of the chromosomal
conformation on the cells functioning.


title:
Thermoelectric performance of spin Seebeck effect in Fe3O4/Pt-based thin
  film heterostructures

abstract:
  We report a systematic study on the thermoelectric performance of spin
Seebeck devices based on Fe3O4/Pt junction systems. We explore two types of
device geometries: a spin Hall thermopile and spin Seebeck multilayer
structures. The spin Hall thermopile increases the sensitivity of the spin
Seebeck effect, while the increase in the sample internal resistance has a
detrimental effect on the output power. We found that the spin Seebeck
multilayers can overcome this limitation since the multilayers exhibit the
enhancement of the thermoelectric voltage and the reduction of the internal
resistance simultaneously, therefore resulting in significant power
enhancement. This result demonstrates that the multilayer structures are useful
for improving the thermoelectric performance of the spin Seebeck effect.


title:
A new system of coordinates for the tilings $\{p,3\}$ and
  $\{p$$-$$2,4\}$

abstract:
  In this paper, we indicate a new way to define coordinates for the tiles of
the tilings $\{p,3\}$ and $\{p$$-$$2,4\}$ where the natural number $p$
satisfies $p\geq 7$.


title: Regression-based Intra-prediction for Image and Video Coding

abstract:
  By utilizing previously known areas in an image, intra-prediction techniques
can find a good estimate of the current block. This allows the encoder to store
only the error between the original block and the generated estimate, thus
leading to an improvement in coding efficiency. Standards such as AVC and HEVC
describe expert-designed prediction modes operating in certain angular
orientations alongside separate DC and planar prediction modes. Being designed
predictors, while these techniques have been demonstrated to perform well in
image and video coding applications, they do not necessarily fully utilize
natural image structures. In this paper, we describe a novel system for
developing predictors derived from natural image blocks. The proposed algorithm
is seeded with designed predictors (e.g. HEVC-style prediction) and allowed to
iteratively refine these predictors through regularized regression. The
resulting prediction models show significant improvements in estimation quality
over their designed counterparts across all conditions while maintaining
reasonable computational complexity. We also demonstrate how the proposed
algorithm handles the worst-case scenario of intra-prediction with no error
reporting.


title: Optimal Rate Allocation in Mismatched Multiterminal Source Coding

abstract:
  We consider a multiterminal source coding problem in which a source is
estimated at a central processing unit from lossy-compressed remote
observations. Each lossy-encoded observation is produced by a remote sensor
which obtains a noisy version of the source and compresses this observation
minimizing a local distortion measure which depends only on the marginal
distribution of its observation. The central node, on the other hand, has
knowledge of the joint distribution of the source and all the observations and
produces the source estimate which minimizes a different distortion measure
between the source and its reconstruction. In this correspondence, we
investigate the problem of optimally choosing the rate of each lossy-compressed
remote estimate so as to minimize the distortion at the central processing unit
subject to a bound on the overall communication rate between the remote sensors
and the central unit. We focus, in particular, on two models of practical
relevance: the case of a Gaussian source observed in additive Gaussian noise
and reconstructed under quadratic distortion, and the case of a binary source
observed in bit-flipping noise and reconstructed under Hamming distortion. In
both scenarios we show that there exist regimes under which having more remote
encoders does reduce the source distortion: in other words, having fewer,
high-quality remote estimates provides a smaller distortion than having more,
lower-quality estimates.


title: On $X$-coordinates of Pell equations which are repdigits

abstract:
  Let $b\ge 2$ be a given integer. In this paper, we show that there only
finitely many positive integers $d$ which are not squares, such that the Pell
equation $X^2-dY^2=1$ has two positive integer solutions $(X,Y)$ with the
property that their $X$-coordinates are base $b$-repdigits. Recall that a base
$b$-repdigit is a positive integer all whose digits have the same value when
written in base $b$. We also give an upper bound on the largest such $d$ in
terms of $b$.


title: The Dynamics of Emotions in Online Interaction

abstract:
  We study the changes in emotional states induced by reading and participating
in online discussions, empirically testing a computational model of online
emotional interaction. Using principles of dynamical systems, we quantify
changes in valence and arousal through subjective reports, as recorded in three
independent studies including 207 participants (110 female). In the context of
online discussions, the dynamics of valence and arousal are composed of two
forces: an internal relaxation towards baseline values independent of the
emotional charge of the discussion, and a driving force of emotional states
that depends on the content of the discussion. The dynamics of valence show the
existence of positive and negative tendencies, while arousal increases when
reading emotional content regardless of its polarity. The tendency of
participants to take part in the discussion increases with positive arousal.
When participating in an online discussion, the content of participants'
expression depends on their valence, and their arousal significantly decreases
afterwards as a regulation mechanism. We illustrate how these results allow the
design of agent-based models to reproduce and analyze emotions in online
communities. Our work empirically validates the microdynamics of a model of
online collective emotions, bridging online data analysis with research in the
laboratory.


title: Commutants of weighted shift directed graph operator algebras

abstract:
  We consider non-selfadjoint operator algebras $\mathfrak{L}(G,\lambda)$
generated by weighted creation operators on the Fock-Hilbert spaces of
countable directed graphs $G$. These algebras may be viewed as noncommutative
generalizations of weighted Bergman space algebras, or as weighted versions of
the free semigroupoid algebras of directed graphs. A complete description of
the commutant is obtained together with broad conditions that ensure the double
commutant property. It is also shown that the double commutant property may
fail for $\mathfrak{L}(G,\lambda)$ in the case of the single vertex graph with
two edges and a suitable choice of left weight function $\lambda$.


title:
Regular Bohr-Sommerfeld quantization rules for a h-pseudo-differential
  operator: The method of positive commutators

abstract:
  We revisit in this Note the well known Bohr-Sommerfeld quantization rule (BS)
for 1-D Pseudo-differential self-adjoint Hamiltonians within the algebraic and
microlocal framework of Helffer and Sj\"ostrand; BS holds precisely when the
Gram matrix consisting of scalar products of WKB solutions with respect to the
"flux norm" is not invertible.


title: Twisted reality condition for spectral triple on two points

abstract:
  Lowest dimensional spectral triples with twisted reality condition over the
function algebra on two points are discussed. The gauge perturbations
(fluctuations), chiral gauge perturbations, conformal rescalings, and
permutation of the two points are presented.


title:
Complete Interference Mitigation Through Receiver-Caching in Wyner's
  Networks

abstract:
  We present upper and lower bounds on the per-user multiplexing gain (MG) of
Wyner's circular soft-handoff model and Wyner's circular full model with
cognitive transmitters and receivers with cache memories. The bounds are tight
for cache memories with prelog $\mu\geq 2/3D$ in the soft-handoff model and for
$\mu \geq D$ in the full model, where $D$ denotes the number of possibly
demanded files. In these cases the per-user MG of the two models is $1+\mu/D$,
the same as for non-interfering point-to-point links with caches at the
receivers. Large receiver cache-memories thus allow to completely mitigate
interference in these networks.


title:
Influence of viscosity on acoustic streaming in sessile droplets: an
  experimental and a numerical study with a Streaming Source Spatial Filtering
  (SSSF) method

abstract:
  When an acoustic wave travels in a lossy medium such as a liquid, it
progressively transfers its pseudo-momentum to the fluid, which results in a
steady acoustic streaming. Remarkably, the phenomenon involves a balance
between sound attenuation and shear, such that viscosity vanishes in the final
expression of the velocity field. For this reason, the effect of viscosity has
long been ignored in acoustic streaming experiments. Here, we show
experimentally that the viscosity plays a major role in cavities such as the
streaming induced by surface acoustic waves in sessile droplets. We develop a
numerical model based on the spatial filtering of the streaming source term to
compute the induced flow motion with dramatically reduced computational
requirements. We evidence that acoustic fields in droplets are a superposition
of a chaotic field and a few powerful caustics. It appears that the caustics
drive the flow, which allows a qualitative prediction of the flow structure.
Finally, we reduce the problem to two dimensionless numbers related to the
surface and bulk waves attenuation and simulate hemispherical sessile droplets
resting on a lithium niobate substrate for a range of parameters. Even in such
a baseline configuration, we observe at least four distinct flow regimes. For
each of them, we establish a correlation of the average streaming speed in the
droplet, which is increasingly dependent on the bulk wave attenuation as the
viscosity increases. These correlations extend our results to a wide range of
fluids and actuation frequencies.


title:
Coverage Analysis In Downlink Poisson Cellular Network With
  $\kappa$-$\mu$ Shadowed Fading

abstract:
  The downlink coverage probability of a cellular network, when the base
station locations are modelled by a Poisson point process (PPP), is known when
the desired channel is Nakagami distributed with an integer shape parameter.
However, for many interesting fading distributions such as Rician, Rician
shadowing, $\kappa$-$\mu$, $\eta$-$\mu$, etc., the coverage probability is
unknown. $\kappa$-$\mu$ shadowed fading is a generic fading distribution whose
special cases are many of these popular distributions known so far. In this
letter, we derive the coverage probability when the desired channel experiences
$\kappa$-$\mu$ shadowed fading. Using numerical simulations, we verify our
analytical expressions.


title:
Direct Method for Training Feed-forward Neural Networks using Batch
  Extended Kalman Filter for Multi-Step-Ahead Predictions

abstract:
  This paper is dedicated to the long-term, or multi-step-ahead, time series
prediction problem. We propose a novel method for training feed-forward neural
networks, such as multilayer perceptrons, with tapped delay lines. Special
batch calculation of derivatives called Forecasted Propagation Through Time and
batch modification of the Extended Kalman Filter are introduced. Experiments
were carried out on well-known time series benchmarks, the Mackey-Glass chaotic
process and the Santa Fe Laser Data Series. Recurrent and feed-forward neural
networks were evaluated.


title:
Multiscale modeling of polycrystalline graphene: A comparison of
  structure and defect energies of realistic samples from phase field crystal
  models

abstract:
  We extend the phase field crystal (PFC) framework to quantitative modeling of
polycrystalline graphene. PFC modeling is a powerful multiscale method for
finding the ground state configurations of large realistic samples that can be
further used to study their mechanical, thermal or electronic properties. By
fitting to quantum-mechanical density functional theory (DFT) calculations, we
show that the PFC approach is able to predict realistic formation energies and
defect structures of grain boundaries. We provide an in-depth comparison of the
formation energies between PFC, DFT and molecular dynamics (MD) calculations.
The DFT and MD calculations are initialized using atomic configurations
extracted from PFC ground states. Finally, we use the PFC approach to
explicitly construct large realistic polycrystalline samples and characterize
their properties using MD relaxation to demonstrate their quality.


title:
Idealised hydrodynamic simulations of turbulent oxygen-burning shell
  convection in 4{\pi} geometry

abstract:
  This work investigates the properties of convection in stars with particular
emphasis on entrainment across the upper convective boundary (CB). Idealised
simulations of turbulent convection in the O-burning shell of a massive star
are performed in $4\pi$ geometry on $768^3$ and $1536^3$ grids, driven by a
representative heating rate. A heating series is also performed on the $768^3$
grid. The $1536^3$ simulation exhibits an entrainment rate at the upper CB of
$1.33\times10^{-6}~M_\odot~\mathrm{s}^{-1}$. The $768^3$ simulation with the
same heating rate agrees within 17 per cent. The entrainment rate at the upper
convective boundary is found to scale linearly with the driving luminosity and
with the cube of the shear velocity at the upper boundary, while the radial RMS
fluid velocity scales with the cube root of the driving luminosity, as
expected. The mixing is analysed in a 1D diffusion framework, resulting in a
simple model for CB mixing. The analysis confirms previous findings that
limiting the MLT mixing length to the distance to the CB in 1D simulations
better represents the spherically-averaged radial velocity profiles from the 3D
simulations and provides an improved determination of the reference diffusion
coefficient $D_0$ for the exponential diffusion CB mixing model in 1D. From the
3D simulation data we adopt as the convective boundary the location of the
maximum gradient in the horizontal velocity component which has $2\sigma$
spatial fluctuations of $\approx0.17 H_P$ . The exponentially decaying
diffusion CB mixing model with $f = 0.03$ reproduces the spherically-averaged
3D abundance profiles.


title:
The chiral S=-1 meson-baryon interaction with new constrains on the NLO
  contributions

abstract:
  We present a study of the $S=-1$ meson-baryon interaction, employing a chiral
SU(3) Lagrangian up to next-to-leading order (NLO) and implementing
unitarization in coupled channels. The parameters of the model have been fitted
to a large set of experimental scattering data in different two-body channels,
to threshold branching ratios, and to the precise SIDDHARTA value of the energy
shift and width of kaonic hidrogen. In contrast to other groups, we have taken
into consideration the $K^- p\to K^+\Xi^-, K^0\Xi^0$ reaction data, since we
found in a previous work to be especially sensitive to the NLO parameters of
the chiral Lagrangian. In the present work we also include the Born terms,
which usually have very little effect, and find them to be non-negligible in
the $K^- p\to K\Xi$ channels, correspondingly causing significant modifications
to the NLO parameters. We furthermore show that the importance of the Born
terms becomes more visible in the isospin projected amplitudes of the $K^-p \to
K\Xi$ reactions. The measurement of processes that filter single isospin
components, like the $K^0_L p \to K^+ \Xi^0$ reaction that could be measured at
the proposed secondary $K^0_L$ beam at Jlab, would put valuable constraints on
the chiral models describing the meson-baryon interaction in the $S=-1$ sector.


title: Adaptive Modulation with Impulsive Interference

abstract:
  In this letter, we analyze power and rate adaptation in a point-to-point link
with Rayleigh fading and impulsive interference. We model the impulsive
interference as a Bernoulli-Gaussian random process. Adaptation is used to
maximize the average spectral efficiency by changing power and rate of the
transmission subject to an average power and instantaneous probability of error
constraints. Without impulsive interference, it is well known that
water-filling is optimal for block fading. We provide two simple schemes that
show that the conventional water-filling algorithm is not optimal in an
impulsive interference channel.


title: Operator Space Structures on $\ell^1(n).$

abstract:
  We show that the complex normed linear space $\ell^1(n),$ $n>1,$ has no
isometric embedding into $k\times k$ complex matrices for any $k\in \mathbb{N}$
and discuss a class of infinite dimensional operator space structures on it.


title:
An Asynchronous Early Output Full Adder and a Relative-Timed Ripple
  Carry Adder

abstract:
  This article presents the design of a new asynchronous early output full
adder which when cascaded leads to a relative-timed ripple carry adder (RCA).
The relative-timed RCA requires imposing a very small relative-timing
assumption to overcome the problem of gate orphans associated with internal
carry propagation. The relative-timing assumption is however independent of the
RCA size. The primary benefits of the relative-timed RCA are processing of
valid data incurs data-dependent forward latency, while the processing of
spacer involves a very fast constant time reverse latency of just 1 full adder
delay which represents the ultimate in the design of an asynchronous RCA with
the fastest reset. The secondary benefits of the relative-timed RCA are it
achieves good optimization of power and area metrics simultaneously. A 32-bit
relative-timed RCA constructed using the proposed early output full adder
achieves respective reductions in forward latency by 67%, 10% and 3.5% compared
to the optimized strong-indication, weak-indication, and early output 32-bit
asynchronous RCAs existing in the literature. Based on a similar comparison,
the proposed 32-bit relative-timed RCA achieves corresponding reductions in
cycle time by 83%, 12.7% and 6.4%. In terms of area, the proposed 32-bit
relative-timed RCA occupies 27% less Silicon than its optimized
strong-indication counterpart and 17% less Silicon than its optimized
weak-indication counterpart, and features increased area occupancy by a meager
1% compared to the optimized early output 32-bit asynchronous RCA. The average
power dissipation of all the asynchronous 32-bit RCAs are found to be
comparable since they all satisfy the monotonic cover constraint. The
simulation results obtained correspond to a 32/28nm CMOS process.


title: A Fault Tolerance Improved Majority Voter for TMR System Architectures

abstract:
  For digital system designs, triple modular redundancy (TMR), which is a
3-tuple version of N-modular redundancy is widely preferred for many
mission-control and safety-critical applications. The TMR scheme involves
two-times duplication of the simplex system hardware, with a majority voter
ensuring correctness provided at least two out of three copies of the system
remain operational. Thus the majority voter plays a pivotal role in ensuring
the correct operation of the system. The fundamental assumption implicit in the
TMR scheme is that the majority voter does not become faulty, which may not
hold well for implementations based on latest technology nodes with dimensions
of the order of just tens of nanometers. To overcome the drawbacks of the
classical majority voter some new voter designs were put forward in the
literature with the aim of enhancing the fault tolerance. However, these voter
designs generally ensure the correct system operation in the presence of either
a faulty function module or the faulty voter, considered only in isolation.
Since multiple faults may no longer be excluded in the nanoelectronics regime,
simultaneous fault occurrences on both the function module and the voter should
be considered, and the fault tolerance of the voters have to be analyzed under
such a scenario. In this context, this article proposes a new fault-tolerant
majority voter which is found to be more robust to faults than the existing
voters in the presence of faults occurring internally and/or externally to the
voter. Moreover, the proposed voter features less power dissipation, delay, and
area metrics based on the simulation results obtained by using a 32/28nm CMOS
process.


title: SplitBox: Toward Efficient Private Network Function Virtualization

abstract:
  This paper presents SplitBox, a scalable system for privately processing
network functions that are outsourced as software processes to the cloud.
Specifically, providers processing the network functions do not learn the
network policies instructing how the functions are to be processed. We first
propose an abstract model of a generic network function based on match-action
pairs, assuming that this is processed in a distributed manner by multiple
honest-but-curious providers. Then, we introduce our SplitBox system for
private network function virtualization and present a proof-of-concept
implementation on FastClick -- an extension of the Click modular router --
using a firewall as a use case. Our experimental results show that SplitBox
achieves a throughput of over 2 Gbps with 1 kB-sized packets on average,
traversing up to 60 firewall rules.


title:
Unravelling the role of phoretic and hydrodynamic interactions in active
  colloidal suspensions

abstract:
  Active fluids comprise a variety of systems composed of elements immersed in
a fluid environment which can convert some form of energy into directed motion;
as such they are intrinsically out-of-equilibrium in the absence of any
external forcing. A fundamental problem in the physics of active matter
concerns the understanding of how the characteristics of the autonomous
propulsion and agent-agent interactions determine the collective dynamics of
the system. We study numerically suspensions of self-propelled diffusiophoretic
colloids, in (quasi)-2d configurations, accounting for both dynamically
resolved solute-mediated phoretic interactions and solvent-mediated
hydrodynamic interactions. Our results show that the system displays different
scenarios at changing the colloid-solute affinity and it develops a cluster
phase in the chemoattractive case. We study the statistics of cluster sizes and
cluster morphologies for different magnitudes of colloidal activity. Finally,
we provide evidences that hydrodynamics plays a relevant role in the
aggregation kinetics and cluster morphology, significantly hindering the
cluster growth.


title: Pure single photons from a trapped atom source

abstract:
  Single atoms or atom-like emitters are the purest source of on-demand single
photons, they are intrinsically incapable of multi-photon emission. To
demonstrate this degree of purity we have realized a tunable, on-demand source
of single photons using a single ion trapped at the common focus of high
numerical aperture lenses. Our trapped-ion source produces single-photon pulses
at a rate of 200 kHz with g$^2(0) = (1.9 \pm 0.2) \times 10^{-3}$, without any
background subtraction. The corresponding residual background is accounted for
exclusively by detector dark counts. We further characterize the performance of
our source by measuring the violation of a non-Gaussian state witness and show
that its output corresponds to ideal attenuated single photons. Combined with
current efforts to enhance collection efficiency from single emitters, our
results suggest that single trapped ions are not only ideal stationary qubits
for quantum information processing, but promising sources of light for scalable
optical quantum networks.


title: Multiphoton controllable transport between remote resonators

abstract:
  We develop a novel method for multiphoton controllable transport between
remote resonators. Specifically, an auxiliary resonator is used to control the
coherent long-range coupling of two spatially separated resonators, mediated by
a coupled-resonator chain of arbitrary length. In this manner, an arbitrary
multiphoton quantum state can be either transmitted through or reflected off
the intermediate chain on demand, with very high fidelity. We find, on using a
time-independent perturbative treatment, that quantum information leakage of an
arbitrary Fock state is limited by two upper bounds, one for the transmitted
case and the other for the reflected case. In principle, the two upper bounds
can be made arbitrarily small, which is confirmed by numerical simulations.


title:
Spiked solutions for Schr\"odinger systems with Sobolev critical
  exponent: the cases of competitive and weakly cooperative interactions

abstract:
  In this paper we deal with the nonlinear Schr\"odinger system \[ -\Delta u_i
=\mu_i u_i^3 + \beta u_i \sum_{j\neq i} u_j^2 + \lambda_i u_i, \qquad
u_1,\ldots, u_m\in H^1_0(\Omega) \] in dimension 4, a problem with critical
Sobolev exponent. In the competitive case ($\beta<0$ fixed or $\beta\to
-\infty$) or in the weakly cooperative case ($\beta\geq 0$ small), we
construct, under suitable assumptions on the Robin function associated to the
domain $\Omega$, families of positive solutions which blowup and concentrate at
different points as $\lambda_1,\ldots, \lambda_m\to 0$. This problem can be
seen as a generalization for systems of a Brezis-Nirenberg type problem.


title: On-chip generation of heralded photon-number states

abstract:
  Beyond the use of genuine monolithic integrated optical platforms, we report
here a hybrid strategy enabling on-chip generation of configurable heralded
two-photon states. More specifically, we combine two different fabrication
techniques, \textit{i.e.}, non-linear waveguides on lithium niobate for
efficient photon-pair generation and femtosecond-laser-direct-written
waveguides on glass for photon manipulation. Through real-time device
manipulation capabilities, a variety of path-coded heralded two-photon states
can be produced, ranging from product to entangled states. Those states are
engineered with high levels of purity, assessed by fidelities of 99.5$\pm$8\%
and 95.0$\pm$8\%, respectively, obtained via quantum interferometric
measurements. Our strategy therefore stands as a milestone for further
exploiting entanglement-based protocols, relying on engineered quantum states,
and enabled by scalable and compatible photonic circuits.


title: Frobenius restricted varieties in numerical semigroups

abstract:
  The common behaviour of many families of numerical semigroups led up to
defining, firstly, the Frobenius varieties and, secondly, the (Frobenius)
pseudo-varieties. However, some interesting families are still out of these
definitions. To overcome this situation, here we introduce the concept of
restricted Frobenius variety (or R-variety). We will generalize most of the
results for varieties and pseudo-varieties to R-varieties. In particular, we
will study the tree structure that arise within them.


title: Constant Envelope Signaling in MIMO Channels

abstract:
  The capacity of the point-to-point vector Gaussian channel under the peak
power constraint is not known in general. This paper considers a simpler
scenario in which the input signal vector is forced to have a constant envelope
(or norm). The capacity-achieving distribution for the non-identity $2\times 2$
MIMO channel when the input vector lies on a circle in $\mathbb{R}^2$ is
obtained and is shown to have a finite number of mass points on the circle.
Subsequently, it is shown that the degrees of freedom (DoF) of a full-rank $n$
by $n$ channel with constant envelope signaling is $n-1$ and it can be achieved
by a uniform distribution over the surface of the hypersphere whose radius is
defined by the constant envelope. Finally, for the 2 by 2 channel, the power
allocation scheme of the constant envelope signaling is compared with that of
the conventional case, in which the constraint is on the average transmitted
power. It is observed that when the condition number of the channel is close to
one, both schemes have a similar trend while this is not the case as the
condition number grows.


title: Categorification of quantum symmetric pairs I

abstract:
  We categorify a coideal subalgebra of the quantum group of
$\mathfrak{sl}_{2r+1}$ by introducing a $2$-category \`a la
Khovanov-Lauda-Rouquier, and show that self-dual indecomposable $1$-morphisms
categorify the canonical basis of this algebra. This allows us to define a
categorical action of this coideal algebra on the categories of modules over
cohomology rings of partial flag varieties and on the BGG category
$\mathcal{O}$ of type B/C.


title:
Gravitational waves from first order phase transitions as a probe of an
  early matter domination era and its inverse problem

abstract:
  We investigate the gravitational wave background from a first order phase
transition in a matter-dominated universe, and show that it has a unique
feature from which important information about the properties of the phase
transition and thermal history of the universe can be easily extracted. Also,
we discuss the inverse problem of such a gravitational wave background in view
of the degeneracy among macroscopic parameters governing the signal.


title:
A Decomposition Based Approach for Solving a General Bilevel Linear
  Programming

abstract:
  Bilevel optimization has been widely used in decision-making process.
However, there still lacks an efficient algorithm to determine an optimal
solution of a bilevel optimization problem, especially for a large-size
problem. To bridge the gap, this paper proposes an efficient decomposition
algorithm for a general bilevel linear programming(GBLP). The simulation
results on large-size testing system demonstrate its correctness and
efficiency.


title:
Integrating User eXperience Practices into Software Development
  Processes: Implications of Subjectivity and Emergent Nature of UX

abstract:
  Many software companies face challenges in their work with User eXperience
(UX) and how to integrate UX practices into existing development processes. A
better understanding of these challenges can help researchers and practitioners
better address them. Existing research does not analyse UX challenges in
relation to other software quality characteristics including usability. In this
empirical study, we have interviewed 17 practitioners from eight software
development companies. Their responses are coded and analysed with thematic
analysis. We report 11 challenges that practitioners face in their work with
UX. Some of these challenges partly overlap with those reported in existing
literature about usability or software quality characteristics. In contrast to
these overlaps, the participants of our study either view many of the
challenges unique to UX, or more severe than for usability or other quality
characteristics. Although at a superficial level challenges with UX and other
quality characteristics overlap, we differentiate these challenges at a deeper
level through two main aspects of UX: subjectivity and emergent nature. In
particular, we identify at least five issues that are essential to the very
nature of UX, and add at least seven extra difficulties to the work of
practitioners. These difficulties can explain why practitioners perceive the
challenges to be more severe than for other quality characteristics. Our
findings can be useful for researchers in identifying industrially relevant
research areas and for practitioners to learn from empirically investigated
challenges and base their improvement efforts on such knowledge. Investigating
the overlaps can help finding research areas not only for enhancing practice of
UX but also software quality in general. It also makes it easier for
practitioners to spot, better understand as well as find mitigation strategies
for UX challenges.


title: In-beam spectroscopy of medium- and high-spin states in $^{133}$Ce

abstract:
  Medium and high-spin states in $^{133}$Ce were investigated using the
$^{116}$Cd($^{22}$Ne, $5n$) reaction and the Gammasphere array. The level
scheme was extended up to an excitation energy of $\sim22.8$ MeV and spin 93/2
. Eleven bands of quadrupole transitions and two new dipole bands are
identified. The connections to low-lying states of the previously known,
high-spin triaxial bands were firmly established, thus fixing the excitation
energy and, in many cases, the spin parity of the levels. Based on comparisons
with cranked Nilsson-Strutinsky calculations and tilted axis cranking covariant
density functional theory, it is shown that all observed bands are
characterized by pronounced triaxiality. Competing multiquasiparticle
configurations are found to contribute to a rich variety of collective
phenomena in this nucleus.


title: Variable-length Non-overlapping Codes

abstract:
  We define a variable-length code having the property that no (non-empty)
prefix of each its codeword is a suffix of any other one, and vice versa. This
kind of code can be seen as an extension of two well-known codes in literature,
called respectively fix-free code and non-overlapping code. In this paper, some
constructive algorithms for such codes are presented as well as numerical
results about their cardinality.


title: Collisional excitation of HC3N by para- and ortho-H2

abstract:
  New calculations for rotational excitation of cyanoacetylene by collisions
with hydrogen molecules are performed to include the lowest 38 rotational
levels of HC3N and kinetic temperatures to 300 K. Calculations are based on the
interaction potential of Wernli et al. A&A, 464, 1147 (2007) whose accuracy is
checked against spectroscopic measurements of the HC3N-H2 complex. The quantum
coupled-channel approach is employed and complemented by quasi-classical
trajectory calculations. Rate coefficients for ortho-H2 are provided for the
first time. Hyperfine resolved rate coefficients are also deduced. Collisional
propensity rules are discussed and comparisons between quantum and classical
rate coefficients are presented. This collisional data should prove useful in
interpreting HC3N observations in the cold and warm ISM, as well as in
protoplanetary disks.


title:
A novel three-axis cylindrical hohlraum designed for inertial
  confinement fusion ignition

abstract:
  A novel ignition hohlraum for indirect-drive inertial confinement fusion is
proposed, which is named as three-axis cylindrical hohlraum (TACH). TACH is a
kind of 6 laser entrance holes (LEHs) hohlraum, which is made of three
cylindrical hohlraums orthogonally jointed. Laser beams are injected through
every entrance hole with the same incident angle of 55{\deg}. The view-factor
simulation result shows that the time-varying drive asymmetry of TACH is no
more than 1.0% in the whole drive pulse period without any supplementary
technology such as beam phasing etc. Its coupling efficiency of TACH is close
to that of 6 LEHs spherical hohlraum with corresponding size. Its
plasma-filling time is close to typical cylindrical ignition hohlraum. Its
laser plasma interaction has as low backscattering as the outer cone of the
cylindrical ignition hohlraum. Therefore, the proposed hohlraum provides a
competitive candidate for ignition hohlraum.


title: Synthetic magnetism for photon fluids

abstract:
  We develop a theory of artificial gauge fields in photon fluids for the cases
of both second-order and third-order optical nonlinearities. This applies to
weak excitations in the presence of pump fields carrying orbital angular
momentum, and is thus a type of Bogoliubov theory. The resulting artificial
gauge fields experienced by the weak excitations are an interesting
generalization of previous cases and reflect the PT-symmetry properties of the
underlying non-Hermitian Hamiltonian. We illustrate the observable consequences
of the resulting synthetic magnetic fields for examples involving both
second-order and third-order nonlinearities.

categories: cond-mat.quant-gas cond-mat.other physics.flu-dyn physics.optics quant-ph


title: Designs and codes in affine geometry

abstract:
  Classical designs and their (projective) q-analogs can both be viewed as
designs in matroids, using the matroid of all subsets of a set and the matroid
of linearly independent subsets of a vector space, respectively. Another
natural matroid is given by the point sets in general position of an affine
space, leading to the concept of an affine design. Accordingly, a t-(n, k,
$\lambda$) affine design of order q is a collection B of (k-1)-dimensional
spaces in the affine geometry A = AG(n-1, q) such that each (t-1)-dimensional
space in A is contained in exactly $\lambda$ spaces of B. In the case $\lambda$
= 1, as usual, one also refers to an affine Steiner system S(t, k, n).
  In this work we examine the relationship between the affine and the
projective q-analogs of designs. The existence of affine Steiner systems with
various parameters is shown, including the affine q-analog S(2, 3, 7) of the
Fano plane. Moreover, we consider various distances in matroids and geometries,
and we discuss the application of codes in affine geometry for error-control in
a random network coding scenario.


title: Aspects of the Bosonic Spectral Action: Successes and Challenges

abstract:
  A short introduction on elements of noncommutative geometry, which offers a
purely geometric interpretation of the Standard Model and implies a higher
derivative gravitational theory, is presented. Physical consequences of almost
commutative manifolds are briefly discussed and cosmological consequences of
the gravitational sector, which is shown not to be plagued by linear
instability, are highlighted. Successes and challenges are discussed. A novel
spectral action proposal based on zeta function regularisation is briefly
presented.


title:
On the convergence of a linesearch based proximal-gradient method for
  nonconvex optimization

abstract:
  We consider a variable metric linesearch based proximal gradient method for
the minimization of the sum of a smooth, possibly nonconvex function plus a
convex, possibly nonsmooth term. We prove convergence of this iterative
algorithm to a critical point if the objective function satisfies the
Kurdyka-Lojasiewicz property at each point of its domain, under the assumption
that a limit point exists. The proposed method is applied to a wide collection
of image processing problems and our numerical tests show that our algorithm
results to be flexible, robust and competitive when compared to recently
proposed approaches able to address the optimization problems arising in the
considered applications.


title: On the distribution of Satake parameters for Siegel modular forms

abstract:
  We prove a harmonically weighted equidistribution result for the $p$-th
Satake parameters of the family of automorphic cuspidal representations of
$\operatorname{PGSp}(2n)$ of fixed weight $\mathtt{k}$ and prime-to-$p$ level
$N\to \infty$. The main tool is a new asymptotic Petersson formula for
$\operatorname{GSp}(2n)$ in the level aspect.


title: Relativistic electrons from sparks in the laboratory

abstract:
  Discharge experiments were carried out at the Eindhoven University of
Technology in 2013. The experimental setup was designed to search for electrons
produced in meter-scale sparks using a 1 MV Marx generator. Negative voltage
was applied to the high voltage (HV) electrode. Five thin (1 mm) plastic
detectors (5 $\rm cm^2$ each) were distributed in various configurations close
to the spark gap. Earlier studies have shown (for HV negative) that X-rays are
produced when a cloud of streamers is developed 30-60 cm from the negative
electrode. This indicates that the electrons producing the X-rays are also
accelerated at this location, that could be in the strong electric field from
counterstreamers of opposite polarity. Comparing our measurements with modeling
results, we find that $\sim$300 keV electrons produced about 30-60 cm from the
negative electrode are the most likely source of our measurements. A
statistical analysis of expected detection of photon bursts by these fiber
detectors indicates that only 20%-45% of the detected bursts could be from soft
($\sim$10 keV) photons, which further supports that the majority of detected
bursts are produced by relativistic electrons.


title: Nonlocal phase transitions in homogeneous and periodic media

abstract:
  We discuss some results related to a phase transition model in which the
potential energy induced by a double-well function is balanced by a fractional
elastic energy. In particular, we present asymptotic results (such as
$\Gamma$-convergence, energy bounds and density estimates for level sets),
flatness and rigidity results, and the construction of planelike minimizers in
periodic media.
  Finally, we consider a nonlocal equation with a multiwell potential,
motivated by models arising in crystal dislocations, and we construct orbits
exhibiting symbolic dynamics, inspired by some classical results by Paul
Rabinowitz.


title: Exponential Machines

abstract:
  Modeling interactions between features improves the performance of machine
learning solutions in many domains (e.g. recommender systems or sentiment
analysis). In this paper, we introduce Exponential Machines (ExM), a predictor
that models all interactions of every order. The key idea is to represent an
exponentially large tensor of parameters in a factorized format called Tensor
Train (TT). The Tensor Train format regularizes the model and lets you control
the number of underlying parameters. To train the model, we develop a
stochastic Riemannian optimization procedure, which allows us to fit tensors
with 2^160 entries. We show that the model achieves state-of-the-art
performance on synthetic data with high-order interactions and that it works on
par with high-order factorization machines on a recommender system dataset
MovieLens 100K.


title: Another Generalization of the Reed-Muller Codes

abstract:
  The punctured binary Reed-Muller code is cyclic and was generalized into the
punctured generalized Reed-Muller code over $\gf(q)$ in the literature. The
major objective of this paper is to present another generalization of the
punctured binary Reed-Muller code. Another objective is to construct a family
of reversible cyclic codes that are related to the newly generalized
Reed-Muller codes.


title: Popular Conjectures as a Barrier for Dynamic Planar Graph Algorithms

abstract:
  The dynamic shortest paths problem on planar graphs asks us to preprocess a
planar graph $G$ such that we may support insertions and deletions of edges in
$G$ as well as distance queries between any two nodes $u,v$ subject to the
constraint that the graph remains planar at all times. This problem has been
extensively studied in both the theory and experimental communities over the
past decades and gets solved millions of times every day by companies like
Google, Microsoft, and Uber. The best known algorithm performs queries and
updates in $\tilde{O}(n^{2/3})$ time, based on ideas of a seminal paper by
Fakcharoenphol and Rao [FOCS'01]. A $(1+\varepsilon)$-approximation algorithm
of Abraham et al. [STOC'12] performs updates and queries in
$\tilde{O}(\sqrt{n})$ time. An algorithm with $O(polylog(n))$ runtime would be
a major breakthrough. However, such runtimes are only known for a
$(1+\varepsilon)$-approximation in a model where only restricted weight updates
are allowed due to Abraham et al. [SODA'16], or for easier problems like
connectivity.
  In this paper, we follow a recent and very active line of work on showing
lower bounds for polynomial time problems based on popular conjectures,
obtaining the first such results for natural problems in planar graphs. Such
results were previously out of reach due to the highly non-planar nature of
known reductions and the impossibility of "planarizing gadgets". We introduce a
new framework which is inspired by techniques from the literatures on distance
labelling schemes and on parameterized complexity.
  Using our framework, we show that no algorithm for dynamic shortest paths or
maximum weight bipartite matching in planar graphs can support both updates and
queries in amortized $O(n^{\frac{1}{2}-\varepsilon})$ time, for
$\varepsilon>0$, unless the classical APSP problem can be solved in truly
subcubic time, [...]


title: Transmission of spin waves in ordered FeRh epitaxial thin films

abstract:
  We report on B2-ordering dependence of magnetostatic surface spin waves in
ferromagnetic FeRh at room temperature. Spin waves transmit over a distance
longer than 21 {\mu}m in highly ordered FeRh alloys even with relatively large
spin-orbit interaction. The long-range transmission likely arises from the
induced Rh moments of the ordered FeRh due to ferromagnetic exchange
interaction between Fe and Rh. The results indicate a potential of using FeRh
in spintronic and magnonic applications by integrating with other fascinating
magnetic characteristics of FeRh such as electric field induced magnetic phase
transition.


title:
Conservative classical and quantum resolution limits for incoherent
  imaging

abstract:
  I propose classical and quantum limits to the statistical resolution of two
incoherent optical point sources from the perspective of minimax parameter
estimation. Unlike earlier results based on the Cram\'er-Rao bound, the limits
proposed here, based on the worst-case error criterion and a Bayesian version
of the Cram\'er-Rao bound, are valid for any biased or unbiased estimator and
obey photon-number scalings that are consistent with the behaviors of actual
estimators. These results prove that, from the minimax perspective, the
spatial-mode demultiplexing (SPADE) measurement scheme recently proposed by
Tsang, Nair, and Lu [Phys. Rev. X 6, 031033 (2016)] remains superior to direct
imaging for sufficiently high photon numbers.


title: Leggett modes and multi-band superconductivity in Sr2RuO4

abstract:
  Sr$_2$RuO$_4$ is a prototypical multi-band superconductor with three bands
crossing the Fermi level. These bands exhibit distinct dimensional
characteristics, with one quasi-2D $\gamma$-band and two quasi-1D $\alpha$- and
$\beta$-bands. This leads to the expectation that the superconductivity on the
$\gamma$-band may be only weakly Josephson-coupled to that on the other two
bands. Based on an explicit microscopic weak coupling calculation appropriate
for Sr$_2$RuO$_4$, we study the collective Leggett modes associated with the
relative phase oscillations between the bands and show that a relatively soft
Leggett mode exists due to the comparatively weaker inter-band Josephson
coupling. These calculations also provide insight into why the superconducting
gap magnitudes may be comparable on all three bands, despite the noticeable
differences between the $\gamma$ and $\alpha, \beta$ bands. The analyses can be
readily applied to other multi-band superconductors.


title: Analytic Hypoellipticity for Sums of Squares and the Treves Conjecture

abstract:
  We are concerned with the problem of real analytic regularity of the
solutions of sums of squares with real analytic coefficients. Treves conjecture
states that an operator of this type is analytic hypoelliptic if and only if
all the strata in the Poisson-Treves stratification are symplectic.
  We produce a model operator, $ P_{1} $, having a single symplectic stratum
and prove that it is Gevrey $ s_{0} $ hypoelliptic and not better. See Theorem
\ref{th:1} for a definition of $ s_{0} $. We also show that this phenomenon has
a microlocal character.
  We point out explicitly that this is a counterexample to the sufficient part
of Treves conjecture and not to the necessary part, which is still an open
problem.


title: Speed-dependent ice bandings in freezing colloidal suspensions

abstract:
  Formation mechanism of speed-dependent ice bandings in freezing colloidal
suspensions, of significance in frost heaving and materials science, remains a
mystery. With quantitative experiments, we propose a possible mechanism of
speed-dependent ice bandings by focusing on the particle packing density and
dynamic interface undercooling. The particle packing density ahead of the
freezing interface decreases with increasing pulling speeds, attributed to the
speed-dependent packing of particles. Through affecting the curvature
undercooling of pore ices, the speed-dependent packing of particles can be used
to explain speed-dependent thicknesses of ice bandings. The dynamic interface
undercooling was obtained to explore curvature undercooling of pore ices and
quantitative details of transient interface positions, speeds and undercooling
were given. All the evidences imply that the speed-dependent particle packing
and dynamic interface undercooling are responsible for speed-dependent ice
bandings.


title:
Improvements on Particle Tracking Velocimetry: model-free calibration
  and noiseless measurement of second order statistics of the velocity field

abstract:
  This article describes two independent developments aimed at improving the
Particle Tracking Method for measurements of flow or particle velocities.
First, a stereoscopic multicamera calibration method that does not require any
optical model is described and evaluated. We show that this new calibration
method gives better results than the most commonly-used technique, based on the
Tsai camera/optics model. Additionally, the methods uses a simple interpolant
to compute the transformation matrix and it is trivial to apply for any
experimental fluid dynamics visualization set up. The second contribution
proposes a solution to remove noise from Eulerian measurements of velocity
statistics obtained from Particle Tracking velocimetry, without the need of
filtering and/or windowing. The novel method presented here is based on
recomputing particle displacement measurements from two consecutive frames for
multiple different time-step values between frames. We show the successful
application of this new technique to recover the second order velocity
structure function of the flow. Increased accuracy is demonstrated by comparing
the dissipation rate of turbulent kinetic energy measured from the second order
structure function against previously validated measurements. These two
techniques for improvement of experimental fluid/particle velocity measurements
can be combined to provide high accuracy 3D particle and/or flow velocity
statistics and derived variables needed to characterize a turbulent flow.


title:
A Mid-level Video Representation based on Binary Descriptors: A Case
  Study for Pornography Detection

abstract:
  With the growing amount of inappropriate content on the Internet, such as
pornography, arises the need to detect and filter such material. The reason for
this is given by the fact that such content is often prohibited in certain
environments (e.g., schools and workplaces) or for certain publics (e.g.,
children). In recent years, many works have been mainly focused on detecting
pornographic images and videos based on visual content, particularly on the
detection of skin color. Although these approaches provide good results, they
generally have the disadvantage of a high false positive rate since not all
images with large areas of skin exposure are necessarily pornographic images,
such as people wearing swimsuits or images related to sports. Local feature
based approaches with Bag-of-Words models (BoW) have been successfully applied
to visual recognition tasks in the context of pornography detection. Even
though existing methods provide promising results, they use local feature
descriptors that require a high computational processing time yielding
high-dimensional vectors. In this work, we propose an approach for pornography
detection based on local binary feature extraction and BossaNova image
representation, a BoW model extension that preserves more richly the visual
information. Moreover, we propose two approaches for video description based on
the combination of mid-level representations namely BossaNova Video Descriptor
(BNVD) and BoW Video Descriptor (BoW-VD). The proposed techniques are
promising, achieving an accuracy of 92.40%, thus reducing the classification
error by 16% over the current state-of-the-art local features approach on the
Pornography dataset.


title: Detecting Relative Anomaly

abstract:
  System states that are anomalous from the perspective of a domain expert
occur frequently in some anomaly detection problems. The performance of
commonly used unsupervised anomaly detection methods may suffer in that
setting, because they use frequency as a proxy for anomaly. We propose a novel
concept for anomaly detection, called relative anomaly detection. It is
tailored to be robust towards anomalies that occur frequently, by taking into
account their location relative to the most typical observations. The
approaches we develop are computationally feasible even for large data sets,
and they allow real-time detection. We illustrate using data sets of potential
scraping attempts and Wi-Fi channel utilization, both from Google, Inc.


title:
Unraveling the CP phase of top-Higgs coupling in associated production
  at the LHC

abstract:
  We study the sensitivity of top polarization observables to the CP phase
$\zeta_t$ in the top Yukawa coupling in the process $pp\to thj$ at the 14 TeV
high-luminosity run of the Large Hadron Collider (HL-LHC). We calculate the top
polarization in this process as well as an azimuthal asymmetry of the charged
lepton arising from the decay of the top in the lab frame. We find that the
dependence of this lab-frame azimuthal asymmetry on the phase $\zeta_t$ closely
resembles the dependence of the top polarization on $\zeta_t$. As compared to
the cross section, which is sensitive to $\zeta_t$ for larger values, the
lepton azimuthal asymmetry can provide a sensitive measurement of $\zeta_t$ for
smaller values.


title:
On the number of non-zero character values in generalized blocks of
  symmetric groups

abstract:
  Given a generalized $e$-block $B$ of a symmetric group and an $e$-regular
conjugacy class $C$, we study the number of irreducible characters in $B$ which
do not vanish on $C$ and find lower bounds for it.


title: Looking Backward and Looking Forward

abstract:
  Filtering has had a profound impact as a device of perceiving information and
deriving agent expectations in dynamic economic models. For an abstract
economic system, this paper shows that the foundation of applying the filtering
method corresponds to the existence of a conditional expectation as an
equilibrium process. Agent-based rational behavior of looking backward and
looking forward is generalized to a conditional expectation process where the
economic system is approximated by a class of models, which can be represented
and estimated without information loss. The proposed framework elucidates the
range of applications of a general filtering device and is not limited to a
particular model class such as rational expectations.


title:
Heat and charge current fluctuations and the time dependent coefficient
  of performance for a nanoscale refrigerator

abstract:
  We theoretically investigate the coefficient of performance (COP) of a
mesoscopic thermoelectric refrigerator realized by using a tunnel junction. We
analyze the influence of particle and heat current fluctuations on the COP out
of the equilibrium regime. We calculate the average COP by using full counting
statistics and find that it depends on the measurement time $\tau$. The
deviation from the macroscopic COP value can be expressed with the Skellam
distribution at all times. This result enables us to improve the Gaussian
approximation valid within the linear response regime, which cannot predict the
average COP in the limit of $\tau \to 0$. We illustrate the time dependence of
the average COP and find that in the short-time regime, the average COP
possesses a minimum. In order to confirm the physical consistency far from
equilibrium, we propose checking the correlation coefficient between the
particle and the heat currents in addition to the positivity of the entropy
production rate.


title: Dynamical Tides Reexpressed

abstract:
  Zahn (1975) first put forward and calculated in detail the torque experienced
by stars in a close binary systems due to dynamical tides. His widely used
formula for stars with radiative envelopes and convective cores is expressed in
terms of the stellar radius, even though the torque is actually being applied
to the convective core at the core radius. This results in a large prefactor,
which is very sensitive to the global properties of the star, that multiplies
the torque. This large factor is compensated by a very small multiplicative
factor, $E_{2}$. Although this is mathematically accurate, depending on the
application this can lead to significant errors. The problem is even more
severe, since the calculation of $E_{2}$ itself is non-trivial, and different
authors have obtained inconsistent values of $E_{2}$. Moreover, many codes
(e.g. BSE, StarTrack, MESA) interpolate (and sometimes extrapolate) a fit of
$E_{2}$ values to the stellar mass, often in regimes where this is not sound
practice. We express the torque in an alternate form, cast in terms of
parameters at the envelope-core boundary and a dimensionless coefficient,
$\beta_{2}$. Previous attempts to express the torque in such a form are either
missing an important factor, which depends on the density profile of the star,
or are not easy to implement. We show that $\beta_{2}$ is almost independent of
the properties of the star and its value is approximately unity. Our formula
for the torque is simple to implement and avoids the difficulties associated
with the classic expression.


title: Decidability Results for Multi-objective Stochastic Games

abstract:
  We study stochastic two-player turn-based games in which the objective of one
player is to ensure several infinite-horizon total reward objectives, while the
other player attempts to spoil at least one of the objectives. The games have
previously been shown not to be determined, and an approximation algorithm for
computing a Pareto curve has been given. The major drawback of the existing
algorithm is that it needs to compute Pareto curves for finite horizon
objectives (for increasing length of the horizon), and the size of these Pareto
curves can grow unboundedly, even when the infinite-horizon Pareto curve is
small. By adapting existing results, we first give an algorithm that computes
the Pareto curve for determined games. Then, as the main result of the paper,
we show that for the natural class of stopping games and when there are two
reward objectives, the problem of deciding whether a player can ensure
satisfaction of the objectives with given thresholds is decidable. The result
relies on intricate and novel proof which shows that the Pareto curves contain
only finitely many points. As a consequence, we get that the two-objective
discounted-reward problem for unrestricted class of stochastic games is
decidable.


title:
Superconducting Properties of the Non-Centrosymmetric Superconductor
  Re6Hf

abstract:
  The synthesis and detailed characterization of the noncentrosymmetric
superconductor Re$_{6}$Hf using powder x-ray diffraction (XRD), magnetization,
transport and thermodynamic measurements are reported. XRD confirms the crystal
structure of Re$_{6}$Hf to be cubic noncentrosymmetric $\alpha$-\textit{Mn}
with a lattice parameter a = 9.6850(3)\text{\AA}. Resistivity, DC and AC
magnetization confirms the bulk superconducting transition T$_{c}^{onset} \sim
$ ~ 5.96 K. The lower critical field H$_{C1}(0)\approx$ 5.6 mT and upper
critical H$_{C2}(0)$ was found to be around 12.2 T which is greater than the
Pauli limiting field, indicating unconventional behavior in Re$_{6}$Hf and
leads to the possibility of triplet pairing. A sharp discontinuity in the
specific heat data was observed around T$_{c}$ indicating bulk
superconductivity, and the normalized specific heat jump is $\Delta
C_{el}$/$\gamma_{n}$T$_{c}$ = 1.53 which is in close agreement with BCS value.
Superconducting electronic specific heat data is fitted reasonably well for an
exponential relation with Sommerfeld coefficient ($\gamma$) showing a linear
relation with magnetic field suggesting that in Re$_{6}$Hf dominant pairing
channel is s-wave with isotropic superconducting gap parameter without nodes.


title:
Fixed-node and fixed-phase approximations and their relationship to
  variable spins in quantum Monte Carlo

abstract:
  We compare the fixed-phase approximation with the better known, but closely
related fixed-node approximation on several testing examples. We found that
both approximations behave very similarly with the fixed-phase results being
very close to the fixed-node method whenever nodes/phase were of high and
comparable accuracy. The fixed-phase exhibited larger biases when the trial
wave functions errors in the nodes/phase were intentionally driven to
unrealistically large values. We also present a formalism that enables to
describe wave functions with the full antisymmetry in spin-spatial degrees of
freedom using our recently developed method for systems with spins as fully
quantum variables. This opens new possibilities for simulations of fermionic
systems in the fixed-phase approximation formalism.


title:
Search for squarks and gluinos in final states with jets and missing
  transverse momentum at $\sqrt{s}=$ 13 TeV with the ATLAS detector

abstract:
  A search for squarks and gluinos in final states containing hadronic jets,
missing transverse momentum but no electrons or muons is presented. The data
were recorded in 2015 by the ATLAS experiment in $\sqrt{s}=$ 13 TeV
proton--proton collisions at the Large Hadron Collider. No excess above the
Standard Model background expectation was observed in 3.2 fb$^{-1}$ of analyzed
data. Results are interpreted within simplified models that assume R-parity is
conserved and the neutralino is the lightest supersymmetric particle. An
exclusion limit at the 95% confidence level on the mass of the gluino is set at
1.51 TeV for a simplified model incorporating only a gluino octet and the
lightest neutralino, assuming the lightest neutralino is massless. For a
simplified model involving the strong production of mass-degenerate first- and
second-generation squarks, squark masses below 1.03 TeV are excluded for a
massless lightest neutralino. These limits substantially extend the region of
supersymmetric parameter space excluded by previous measurements with the ATLAS
detector.


title:
Backward-Shifted Strategies Based on SVC for HTTP Adaptive Video
  Streaming

abstract:
  Although HTTP-based video streaming can easily penetrate firewalls and profit
from Web caches, the underlying TCP may introduce large delays in case of a
sudden capacity loss. To avoid an interruption of the video stream in such
cases we propose the Backward-Shifted Coding (BSC). Based on Scalable Video
Coding (SVC), BSC adds a time-shifted layer of redundancy to the video stream
such that future frames are downloaded at any instant. This pre-fetched content
maintains a fluent video stream even under highly variant network conditions
and leads to high Quality of Experience (QoE). We characterize this QoE gain by
analyzing initial buffering time, re-buffering time and content resolution
using the Ballot theorem. The probability generating functions of the playback
interruption and of the initial buffering latency are provided in closed form.
We further compute the quasi-stationary distribution of the video quality, in
order to compute the average quality, as well as temporal variability in video
quality. Employing these analytic results to optimize QoE shows interesting
trade-offs and video streaming at outstanding fluency.


title:
An existence proof of a symmetric periodic orbit in the octahedral
  six-body problem

abstract:
  We present a proof of the existence of a periodic orbit for the Newtonian
six-body problem with equal masses. This orbit has three double collisions each
period and no multiple collisions. Our proof is based on the minimization of
the Lagrangian action functional on a well chosen class of symmetric loops.


title: Spotting the diffusion of New Psychoactive Substances over the Internet

abstract:
  Online availability and diffusion of New Psychoactive Substances (NPS)
represent an emerging threat to healthcare systems. In this work, we analyse
drugs forums, online shops, and Twitter. By mining the data from these sources,
it is possible to understand the dynamics of drugs diffusion and their
endorsement, as well as timely detecting new substances. We propose a set of
visual analytics tools to support analysts in tackling NPS spreading and
provide a better insight about drugs market and analysis.


title:
Ramifications of topology and thermal fluctuations in quasi-2D
  condensates

abstract:
  We explore the topological transformation of quasi-2D Bose-Einstein
condensates of dilute atomic gases, and changes in the low-energy
quasiparticles associated with the geometry of the confining potential. In
particular, we show the density profile of the condensate and quantum
fluctuation follow the transition from a multiply to a simply connected
geometry of the confining potential. The thermal fluctuations, in contrast,
remain multiply connected. The genesis of the key difference lies in the
structure of the low-energy quasiparticles. For which we use the
Hartree-Fock-Bogoliubov, and study the evolution of quasiparticles, the dipole
or the Kohn mode in particular. We, then employ the Hartree-Fock-Bogoliubov
theory with the Popov approximation to investigate the density and the momentum
distribution of the thermal atoms.


title: Aftershocks in a frictional earthquake model

abstract:
  Inspired by spring-block models, we elaborate a "minimal" physical model of
earthquakes which reproduces two main empirical seismological laws, the
Gutenberg-Richter law and the Omori aftershock law. Our new point is to
demonstrate that the simultaneous incorporation of ageing of contacts in the
sliding interface and of elasticity of the sliding plates constitute the
minimal ingredients to account for both laws within the same frictional model.


title:
Effects of valence, geometry and electronic correlations on transport in
  transition metal benzene sandwich molecules

abstract:
  We study the impact of the valence and the geometry on the electronic
structure and transport properties of different transition metal-benzene
sandwich molecules bridging the tips of a Cu nanocontact. Our
density-functional calculations show that the electronic transport properties
of the molecules depend strongly on the molecular geometry which can be
controlled by the nanocontact tips. Depending on the valence of the transition
metal center certain molecules can be tuned in and out of half-metallic
behaviour facilitating potential spintronics applications. We also discuss our
results in the framework of an Anderson impurity model, indicating cases where
the inclusion of local correlations alters the ground state qualitatively. For
Co and V centered molecules we find indications of an orbital Kondo effect.


title: Crowd Counting Considering Network Flow Constraints in Videos

abstract:
  The growth of the number of people in the monitoring scene may increase the
probability of security threat, which makes crowd counting more and more
important. Most of the existing approaches estimate the number of pedestrians
within one frame, which results in inconsistent predictions in terms of time.
This paper, for the first time, introduces a quadratic programming model with
the network flow constraints to improve the accuracy of crowd counting.
Firstly, the foreground of each frame is segmented into groups, each of which
contains several pedestrians. Then, a regression-based map is developed in
accordance with the relationship between low-level features of each group and
the number of people in it. Secondly, a directed graph is constructed to
simulate constraints on people's flow, whose vertices represent groups of each
frame and arcs represent people moving from one group to another. Then, the
people flow can be viewed as an integer flow in the constructed digraph.
Finally, by solving a quadratic programming problem with network flow
constraints in the directed graph, we obtain consistency in people counting.
The experimental results show that the proposed method can reduce the crowd
counting errors and improve the accuracy. Moreover, this method can also be
applied to any ultramodern group-based regression counting approach to get
improvements.


title: The concept of entropic rectifier facing experiments

abstract:
  The transport of molecules in confined media is subject to entropic barriers.
So theoretically, asymmetry of the confinement length may lead to molecular
ratchets with entropy as the only driving force for the biased transport. We
address experimentally this question by performing alternative ionic current
measurements on electrolytes confined in neutral conical nanopores. In case
anions and cations widely differ in size, we show that rectification of ionic
current can be obtained that depends on ions size and cycle frequency,
consistently with the entropic ratchet mechanism.


title:
Control of body motion in an ideal fluid using the internal mass and the
  rotor in the presence of circulation around the body

abstract:
  In this paper we study the controlled motion of an arbitrary two-dimensional
body in an ideal fluid with a moving internal mass and an internal rotor in the
presence of constant circulation around the body. We show that by changing the
position of the internal mass and by rotating the rotor, the body can be made
to move to a given point, and discuss the influence of nonzero circulation on
the motion control. We have found that in the presence of circulation around
the body the system cannot be completely stabilized at an arbitrary point of
space, but fairly simple controls can be constructed to ensure that the body
moves near the given point.


title: Direction of arrival estimation using robust complex Lasso

abstract:
  The Lasso (Least Absolute Shrinkage and Selection Operator) has been a
popular technique for simultaneous linear regression estimation and variable
selection. In this paper, we propose a new novel approach for robust Lasso that
follows the spirit of M-estimation. We define $M$-Lasso estimates of regression
and scale as solutions to generalized zero subgradient equations. Another
unique feature of this paper is that we consider complex-valued measurements
and regression parameters, which requires careful mathematical characterization
of the problem. An explicit and efficient algorithm for computing the $M$-Lasso
solution is proposed that has comparable computational complexity as
state-of-the-art algorithm for computing the Lasso solution. Usefulness of the
$M$-Lasso method is illustrated for direction-of-arrival (DoA) estimation with
sensor arrays in a single snapshot case.


title: Discreteness of $F$-jumping numbers at isolated non-Q-Gorenstein points

abstract:
  We show that the $F$-jumping numbers of a pair $(X, \mathfrak a)$ in positive
characteristic have no limit points whenever the symbolic Rees algebra of
$-K_X$ is finitely generated outside an isolated collection of points. We also
give a characteristic zero version of this result, as well as a generalization
of the Hartshorne-Speiser-Lyubeznik-Gabber stabilization theorem describing the
non-$F$-pure locus of a variety.


title: Walrasian's Characterization and a Universal Ascending Auction

abstract:
  We introduce a novel characterization of all Walrasian price vectors in terms
of forbidden over- and under demanded sets for monotone gross substitute
combinatorial auctions.
  For ascending and descending auctions we suggest a universal framework for
finding the minimum or maximum Walrasian price vectors for monotone gross
substitute combinatorial auctions. An ascending (descending) auction is
guaranteed to find the minimum (maximum) Walrasian if and only if it follows
the suggested framework.


title:
Identifying detrimental effects for multi-orbital superconductivity -
  Application to Sr$_2$RuO$_4$

abstract:
  We propose a general scheme to probe the compatibility of arbitrary pairing
states with a given normal state Hamiltonian by the introduction of a concept
called superconducting fitness. This new quantity gives a direct measure of the
suppression of the superconducting critical temperature in presence of key
symmetry breaking fields. A merit of the superconducting fitness is that it can
be used as a tool to identify non-trivial mechanisms to suppress
superconductivity under various external influences, in particular, magnetic
fields or distortions, even in complex multi-orbital systems. In the light of
this new concept we analyse the multi-band superconductor Sr$_2$RuO$_4$ and
propose a new mechanism for the suppression of superconductivity in
multi-orbital systems, which we call inter-orbital effect, as a possible
explanation for the unusual limiting feature observed in the upper critical
field of this material.


title: Some Epistemic Extensions of G\"odel Fuzzy Logic

abstract:
  In this paper, we introduce some epistemic extensions of G\"odel fuzzy logic
whose Kripke-based semantics have fuzzy values for both propositions and
accessibility relations such that soundness and completeness hold. We adopt
belief as our epistemic operator, then survey some fuzzy implications to
justify our semantics for belief is appropriate. We give a fuzzy version of
traditional muddy children problem and apply it to show that axioms of positive
and negative introspections and Truth are not necessarily valid in our basic
epistemic fuzzy models. In the sequel, we propose a derivation system $K_F$ as
a fuzzy version of classical epistemic logic $K$. Next, we establish some other
epistemic-fuzzy derivation systems $ B_F, T_F, B_F^n$ and $T_F^n$ which are
extensions of $K_F$, and prove that all of these derivation systems are sound
and complete with respect to appropriate classes of Kripke-based models.


title: Neutrino physics and precision cosmology

abstract:
  I review the current status of structure formation bounds on neutrino
properties such as mass and energy density. I also discuss future cosmological
bounds as well as a variety of different scenarios for reconciling cosmology
with the presence of light sterile neutrinos.


title: Coherent pairs of measures and Markov-Bernstein inequalities

abstract:
  All the coherent pairs of measures associated to linear functionals $c_0$ and
$c_1$, introduced by Iserles et al in 1991, have been given by Meijer in 1997.
There exist seven kinds of coherent pairs. All these cases are explored in
order to give three term recurrence relations satisfied by polynomials. The
smallest zero $\mu_{1,n}$ of each of them of degree $n$ has a link with the
Markov-Bernstein constant $M_n$ appearing in the following Markov-Bernstein
inequalities: $$ c_1((p^\prime)^2) \le M_n^2 c_0(p^2), \quad \forall p \in
\mathcal{P}_n, $$ where $M_n=\frac{1}{\sqrt{\mu_{1,n}}}$. The seven kinds of
three term recurrence relations are given. In the case where $c_0 =e^{-x}
dx+\delta(0)$ and $c_1 =e^{-x} dx$, explicit upper and lower bounds are given
for $\mu_{1,n}$, and the asymptotic behavior of the corresponding
Markov-Bernstein constant is stated. Except in a part of one case, $\lim_{n \to
\infty} \mu_{1,n}=0$ is proved in all the cases.


title: A broad 750 GeV diphoton resonance? Not alone

abstract:
  The hint for a possible resonance in the diphoton channel with mass of
750~GeV disappeared in the data presented at ICHEP'16 by ATLAS and CMS.
However, the diphoton final state remains as one of the golden channels for new
physics discoveries at the TeV scale in the LHC experiments. This motivates us
to analyze model-independently the implications of an O(TeV) bump in the
$\gamma\gamma$ final state. By means of forward sum-rules for $\gamma\gamma$
scattering, we show that a spin-0 resonance with mass of the order of the TeV
and a sizable $\gamma\gamma$ partial width -of the order of a few GeV- must be
accompanied by higher spin resonances with $J_R\geq 2$ with similar properties,
as expected in strongly coupled extensions of the Standard Model or,
alternatively, in higher dimensional deconstructed duals. Furthermore,
independently of whether the putative O(TeV) candidate is a scalar or a tensor,
the large contribution to the forward sum-rules in the referred scenario
implies the presence of states in the spectrum with $J_R\geq 2$, these high
spin particles being a manifestation of new extra-dimensions or composite
states of a new strong sector.


title:
Polyglot Neural Language Models: A Case Study in Cross-Lingual Phonetic
  Representation Learning

abstract:
  We introduce polyglot language models, recurrent neural network models
trained to predict symbol sequences in many different languages using shared
representations of symbols and conditioning on typological information about
the language to be predicted. We apply these to the problem of modeling phone
sequences---a domain in which universal symbol inventories and
cross-linguistically shared feature representations are a natural fit.
Intrinsic evaluation on held-out perplexity, qualitative analysis of the
learned representations, and extrinsic evaluation in two downstream
applications that make use of phonetic features show (i) that polyglot models
better generalize to held-out data than comparable monolingual models and (ii)
that polyglot phonetic feature representations are of higher quality than those
learned monolingually.


title: Proper affine actions in non-swinging representations

abstract:
  For a semisimple real Lie group $G$ with an irreducible representation $\rho$
on a finite-dimensional real vector space $V$, we give a sufficient criterion
on $\rho$ for existence of a group of affine transformations of $V$ whose
linear part is Zariski-dense in $\rho(G)$ and that is free, nonabelian and acts
properly discontinuously on $V$.


title: Generalized dark energy interactions with multiple fluids

abstract:
  In the search for an explanation for the current acceleration of the
Universe, scalar fields are the most simple and useful tools to build models of
dark energy. This field, however, must in principle couple with the rest of the
world and not necessarily in the same way to different particles or fluids. We
provide the most complete dynamical system analysis to date, consisting of a
canonical scalar field conformally and disformally coupled to both dust and
radiation. We perform a detailed study of the existence and stability
conditions of the systems and comment on constraints imposed on the disformal
coupling from Big-Bang Nucleosynthesis and given current limits on the
variation of the fine-structure constant.


title:
Noisy Parallel Approximate Decoding for Conditional Recurrent Language
  Model

abstract:
  Recent advances in conditional recurrent language modelling have mainly
focused on network architectures (e.g., attention mechanism), learning
algorithms (e.g., scheduled sampling and sequence-level training) and novel
applications (e.g., image/video description generation, speech recognition,
etc.) On the other hand, we notice that decoding algorithms/strategies have not
been investigated as much, and it has become standard to use greedy or beam
search. In this paper, we propose a novel decoding strategy motivated by an
earlier observation that nonlinear hidden layers of a deep neural network
stretch the data manifold. The proposed strategy is embarrassingly
parallelizable without any communication overhead, while improving an existing
decoding algorithm. We extensively evaluate it with attention-based neural
machine translation on the task of En->Cz translation.


title: Weighted dependency graphs

abstract:
  The theory of dependency graphs is a powerful toolbox to prove asymptotic
normality of sums of random variables. In this article, we introduce a more
general notion of weighted dependency graphs and give normality criteria in
this context. We also provide generic tools to prove that some weighted graph
is a weighted dependency graph for a given family of random variables.
  To illustrate the power of the theory, we give applications to the following
objects: uniform random pair partitions, the random graph model $G(n,M)$,
uniform random permutations, the symmetric simple exclusion process and
multilinear statistics on Markov chains. The application to random permutations
gives a bivariate extension of a functional central limit theorem of Janson and
Barbour. On Markov chains, we answer positively an open question of Bourdon and
Vall\'ee on the asymptotic normality of subword counts in random texts
generated by a Markovian source.


title: Left symmetric algebras from DNA insertion

abstract:
  In this paper, we construct some left-symmetric algebras arising from the
operation of DNA insertion. We define a new operation of insertion by modifying
the simplified insertion as follows: $x\Rightarrow y:=f(\mid x\mid, \mid y
\mid)\sum\limits_{i=o}^{q} y_{1}y_{2}\cdots y_{i} x y_{i+1}\cdots y_{q}$ where
$x = x_{1}x_{2}\cdots x_{p}$ and $y = y_{1}y_{2}\cdots y_{q}$. Then it is
proved that $(x, y, z)_2= (y, x, z)_2$ if and only if $f$ satisfies the
following conditions: $$f(m, n) f(m+n, p)=f(n, p) f(m, n+p)= f(m, p) f(n,
m+p)$$ where $m, n, p\in \mathbb{N}$. The paper also give an important example:
$f(m, n)=\exp\{g(m, n)\}$, where $g(m, n)=k\cdot mn,$ $k$ is a fixed positive
number. We also give simple case to make clear that the intermediate version of
the insertion operation which is the open problem numbered [5] and the operator
of synchronized insertion given in the \cite{Bremner} by Bremner do not satisfy
the left-symmetric identities.


title: An Experimental Evaluation of Regret-Based Econometrics

abstract:
  Using data obtained in a controlled ad-auction experiment that we ran, we
evaluate the regret-based approach to econometrics that was recently suggested
by Nekipelov, Syrgkanis, and Tardos (EC 2015). We found that despite the weak
regret-based assumptions, the results were (at least) as accurate as those
obtained using classic equilibrium-based assumptions. En route we studied to
what extent humans actually minimize regret in our ad auction, and found a
significant difference between the "high types" (players with a high valuation)
who indeed rationally minimized regret and the "low types" who significantly
overbid. We suggest that correcting for these biases and adjusting the
regret-based econometric method may improve the accuracy of estimated values.


title:
GW150914: Spin based constraints on the merger time of the progenitor
  system

abstract:
  We explore the implications of the observed low spin of GW150914 within the
context of stellar astrophysics and progenitor models. We conclude that many of
the recently proposed scenarios are in marked tension with this observation. We
derive a simple model for the observed spin in the case that the progenitor
system was a field binary composed of a black hole (BH) and a Wolf-Rayet star
and explore the implications of the observed spin for this model. The spin
observation allows us to place a lower limit for the delay time between the
formation of the BH+BH binary and the actual merger, $t_{\textrm{merge}}$. We
use typical values for these systems to derive
$t_{\textrm{merge}}\gtrsim10^{8}\,\textrm{yr}$, which proves to be an important
diagnostic for different progenitor models. We anticipate the next series of
events, and the associated spin parameters, will ultimately yield critical
constraints on formation scenarios and on stellar parameters describing the
late-stage evolution of massive stars.


title:
Generating Point Configurations via Hypersingular Riesz Energy With an
  External Field

abstract:
  For a compact $ d $-dimensional rectifiable subset of $ \mathbb{R}^{p} $ we
study asymptotic properties as $ N\to\infty $ of $N$-point configurations
minimizing the energy arising from a Riesz $ s $-potential $ 1/r^s $ and an
external field in the hypersingular case $ s\geq d$. Formulas for the weak$ ^*
$ limit of normalized counting measures of such optimal point sets and the
first-order asymptotic values of minimal energy are obtained. As an
application, we derive a method for generating configurations whose normalized
counting measures converge to a given absolutely continuous measure supported
on a rectifiable subset of $ \mathbb{R}^{p} $. Results on separation and
covering properties of discrete minimizers are given. Our theorems are
illustrated with several numerical examples.


title:
On the homological dimensions of Leavitt path algebras with coefficients
  in commutative rings

abstract:
  In this paper, we give sharp bounds for the homological dimensions of the
Leavitt path algebra $L_K(E)$ of a finite graph $E$ with coefficients in a
commutative ring $K$, as well as establish a formula for calculating the
homological dimensions of $L_K(E)$ when $K$ is a commutative unital algebra
over a field.


title: Fredkin Spin Chain

abstract:
  We introduce a new model of interacting spin 1/2. It describes interaction of
three nearest neighbors. The Hamiltonian can be expressed in terms of Fredkin
gates. The Fredkin gate (also known as the CSWAP gate) is a computational
circuit suitable for reversible computing. Our construction generalizes the
work of Ramis Movassagh and Peter Shor.
  Our model can be solved by means of Catalan combinatorics in the form of
random walks on the upper half of a square lattice [Dyck walks]. Each Dyck path
can be mapped to a wave function of the spins. The ground state is an equally
weighted superposition of Dyck walks [instead of Motzkin walks]. We can also
express it as a matrix product state. We further construct the model of
interacting spins 3/2 and greater half-integer spins. The models with higher
spins require coloring of Dyck walks. We construct SU(k) symmetric model [here
k is the number of colors]. The leading term of the entanglement entropy is
then proportional to the square root of the length of the lattice [like in
Shor-Movassagh model]. The gap closes as a high power of the length of the
lattice.


title: Asymptotic sequential Rademacher complexity of a finite function class

abstract:
  For a finite function class we describe the large sample limit of the
sequential Rademacher complexity in terms of the viscosity solution of a
$G$-heat equation. In the language of Peng's sublinear expectation theory, the
same quantity equals to the expected value of the largest order statistics of a
multidimensional $G$-normal random variable. We illustrate this result by
deriving upper and lower bounds for the asymptotic sequential Rademacher
complexity.


title: Chromatographic separation of radioactive noble gases from xenon

abstract:
  The Large Underground Xenon (LUX) experiment operates at the Sanford
Underground Research Facility to detect nuclear recoils from the hypothetical
Weakly Interacting Massive Particles (WIMPs) on a liquid xenon target. Liquid
xenon typically contains trace amounts of the noble radioactive isotopes
$^{85}$Kr and $^{39}$Ar that are not removed by the in situ gas purification
system. The decays of these isotopes at concentrations typical of
research-grade xenon would be a dominant background for a WIMP search
exmperiment. To remove these impurities from the liquid xenon, a
chromatographic separation system based on adsorption on activated charcoal was
built. 400 kg of xenon was processed, reducing the average concentration of
krypton from 130 ppb to 3.5 ppt as measured by a cold-trap assisted mass
spectroscopy system. A 50 kg batch spiked to 0.001 g/g of krypton was processed
twice and reduced to an upper limit of 0.2 ppt.


title:
Driven polymer translocation in good and bad solvent: effects of
  hydrodynamics and tension propagation

abstract:
  We investigate the driven polymer translocation through a nanometer-scale
pore in the presence and absence of hydrodynamics both in good and bad solvent.
We present our results on tension propagating along the polymer segment on the
cis-side that is measured for the first time using our method that works also
in the presence of hydrodynamics. For simulations we use stochastic rotation
dynamics, also called multi-particle collision dynamics. We find that in the
good solvent the tension propagates very similarly whether hydrodynamics is
included or not. Only the tensed segment is by a constant factor shorter in the
presence of hydrodynamics. The shorter tensed segment and the hydrodynamic
interactions contribute to a smaller friction for the translocating polymer
when hydrodynamics is included, which shows as smaller waiting times and a
smaller exponent in the scaling of the translocation time with the polymer
length. In the bad solvent hydrodynamics has a minimal effect on polymer
translocation in contrast to the good solvent where it speeds up translocation.
We find that under bad-solvent conditions tension does not spread appreciably
along the polymer. Consequently, translocation time does not scale with the
polymer length. By measuring the effective friction in a setup where a polymer
in free solvent is pulled by a constant force at the end, we find that
hydrodynamics does speed up collective polymer motion in the bad solvent even
more effectively than in the good solvent. However, hydrodynamics has a
negligible effect on the motion of individual monomers within the highly
correlated globular conformation on the cis-side and hence on the entire driven
translocation under bad-solvent conditions.


title: Non-arithmetic lattices and the Klein quartic

abstract:
  We give an algebro-geometric construction of some of the non-arithmetic ball
quotients constructed by the author, Parker and Paupert. The new construction
reveals a relationship between the corresponding orbifold fundamental groups
and the automorphism group of the Klein quartic, and also with groups
constructed by Barthel-Hirzebruch-H\"ofer and Couwenberg-Heckman-Looijenga.