title: Flat Helical Nanosieves

abstract:
  Compact and miniaturized devices with flexible functionalities are always
highly demanded in optical integrated systems. Plasmonic nanosieve has been
successfully harnessed as an ultrathin flat platform for complex manipulation
of light, including holography, vortex generation and non-linear processes.
Compared with most of reported single-functional devices, multi-functional
nanosieves might find more complex and novel applications across
nano-photonics, optics and nanotechnology. Here, we experimentally demonstrate
a promising roadmap for nanosieve-based helical devices, which achieves full
manipulations of optical vortices, including its generation, hybridization,
spatial multiplexing, focusing and non-diffraction propagation etc., by
controlling the geometric phase of spin light via over 121 thousands of
spatially-rotated nano-sieves. Thanks to such spin-conversion nanosieve helical
elements, it is no longer necessary to employ the conventional two-beam
interferometric measurement to characterize optical vortices, while the
interference can be realized natively without changing any parts of the current
setup. The proposed strategy makes the far-field manipulations of optical
orbital angular momentum within an ultrathin interface viable and bridges
singular optics and integrated optics. In addition, it enables more unique
extensibility and flexibility in versatile optical elements than traditional
phase-accumulated helical optical devices.


title:
Joint Face Detection and Alignment using Multi-task Cascaded
  Convolutional Networks

abstract:
  Face detection and alignment in unconstrained environment are challenging due
to various poses, illuminations and occlusions. Recent studies show that deep
learning approaches can achieve impressive performance on these two tasks. In
this paper, we propose a deep cascaded multi-task framework which exploits the
inherent correlation between them to boost up their performance. In particular,
our framework adopts a cascaded structure with three stages of carefully
designed deep convolutional networks that predict face and landmark location in
a coarse-to-fine manner. In addition, in the learning process, we propose a new
online hard sample mining strategy that can improve the performance
automatically without manual sample selection. Our method achieves superior
accuracy over the state-of-the-art techniques on the challenging FDDB and WIDER
FACE benchmark for face detection, and AFLW benchmark for face alignment, while
keeps real time performance.


title: An Extremal Series of Eulerian Synchronizing Automata

abstract:
  We present an infinite series of $n$-state Eulerian automata whose reset
words have length at least $(n^2-3)/2$. This improves the current lower bound
on the length of shortest reset words in Eulerian automata. We conjecture that
$(n^2-3)/2$ also forms an upper bound for this class and we experimentally
verify it for small automata by an exhaustive computation.


title:
A framework for computing effective boundary conditions at the interface
  between free fluid and a porous medium

abstract:
  Interfacial boundary conditions determined from empirical or ad-hoc models
remain the standard approach to model fluid flows over porous media, even in
situations where the topology of the porous medium is known. We propose a
non-empirical and accurate method to compute the effective boundary conditions
at the interface between a porous surface and an overlying flow. Using
multiscale expansion (homogenization) approach, we derive a tensorial
generalized version of the empirical condition suggested by Beavers & Joseph
(1967). The components of the tensors determining the effective slip velocity
at the interface are obtained by solving a set of Stokes equations in a small
computational domain near the interface containing both free flow and porous
medium. Using the lid-driven cavity flow with a porous bed, we demonstrate that
the derived boundary condition is accurate and robust by comparing an effective
model to direct numerical simulations. Finally, we provide an open source code
that solves the microscale problems and computes the velocity boundary
condition without free parameters over any porous bed.


title:
Weak and strong structures and the $T_{3.5}$ property for generalized
  topological spaces

abstract:
  We investigate weak and strong structures for generalized topological spaces,
among others products, sums, subspaces, quotients, and the complete lattice of
generalized topologies on a given set. Also we introduce $T_{3.5}$ generalized
topological spaces and give a necessary and sufficient condition for a
generalized topological space to be a $T_{3.5}$ space: they are exactly the
subspaces of powers of a certain natural generalized topology on $[0,1]$. For
spaces with at least two points here we can have even dense subspaces. Also,
$T_{3.5}$ generalized topological spaces are exactly the dense subspaces of
compact $T_4$ generalized topological spaces. We show that normality is
productive for generalized topological spaces. For compact generalized
topological spaces we prove the analogue of the Tychonoff product theorem. We
prove that also Lindel\"ofness (and $\kappa $-compactness) is productive for
generalized topological spaces. On any ordered set we introduce a generalized
topology and determine the continuous maps between two such generalized
topological spaces: for $|X|, |Y| \ge 2$ they are the monotonous maps
continuous between the respective order topologies. We investigate the relation
of sums and subspaces of generalized topological spaces to ways of defining
generalized topological spaces.


title:
Numerical study of renormalization group flows of nuclear effective
  field theory without pions on a lattice

abstract:
  We formulate the next-to-leading order nuclear effective field theory without
pions in the two-nucleon sector on a spatial lattice, and investigate
nonperturbative renormalization group flows in the strong coupling region by
diagonalizing the Hamiltonian numerically. The cutoff (proportional to the
inverse of the lattice constant) dependence of the coupling constants is
obtained by changing the lattice constant with the binding energy and the
asymptotic normalization constant for the groundstate being fixed. We argue
that the critical line can be obtained by looking at the finite-size dependence
of the groundstate energy. We determine the relevant operator and locate the
nontrivial fixed point, as well as the physical flow line corresponding to the
deuteron in the two-dimensional plane of dimensionless coupling constants. It
turns out that the location of the nontrivial fixed point is very close to the
one obtained by the corresponding analytic calculation, but the relevant
operator is quite different.


title:
Analysing health professionals' learning interactions in online social
  networks: A social network analysis approach

abstract:
  Online Social Networking may be a way to support health professionals' need
for continuous learning through interaction with peers and experts.
Understanding and evaluating such learning is important but difficult, and
Social Network Analysis (SNA) offers a solution. This paper demonstrates how
SNA can be used to study levels of participation as well as the patterns of
interactions that take place among health professionals in a large online
professional learning network. Our analysis has shown that their learning
network is highly centralised and loosely connected. The level of participation
is low in general, and most interactions are structured around a small set of
users consisting of moderators and core members. The structural patterns of
interaction indicates there is a chance of small group learning occurring and
requires further investigation to identify those potential learning groups.
This first stage of analysis, to be followed by longitudinal study of the
dynamics of interaction and complemented by content analysis of their
discussion, may contribute to greater sophistication in the analysis and
utilisation of new environments for health professional learning.


title: Quantum and Tunnelling Capacitance in Charge and Spin Qubits

abstract:
  We present a theoretical analysis of the capacitance of a double quantum dot
in the charge and spin qubit configurations probed at high-frequencies. We find
that in general the total capacitance of the system consists of two
state-dependent terms: The quantum capacitance arising from adiabatic charge
motion and the tunnelling capacitance that appears when repopulation occurs at
a rate comparable or faster than the probing frequency. The analysis of the
capacitance lineshape as a function of externally controllable variables offers
a way to characterize the qubits' charge and spin state as well as relevant
system parameters such as charge and spin relaxation times, tunnel coupling,
electron temperature and electron g-factor. Overall, our analysis provides a
formalism to understand dispersive qubit-resonator interactions which can be
applied to high-sensitivity and non-invasive quantum-state readout.


title:
Semantic 3D Reconstruction with Continuous Regularization and Ray
  Potentials Using a Visibility Consistency Constraint

abstract:
  We propose an approach for dense semantic 3D reconstruction which uses a data
term that is defined as potentials over viewing rays, combined with continuous
surface area penalization. Our formulation is a convex relaxation which we
augment with a crucial non-convex constraint that ensures exact handling of
visibility. To tackle the non-convex minimization problem, we propose a
majorize-minimize type strategy which converges to a critical point. We
demonstrate the benefits of using the non-convex constraint experimentally. For
the geometry-only case, we set a new state of the art on two datasets of the
commonly used Middlebury multi-view stereo benchmark. Moreover, our
general-purpose formulation directly reconstructs thin objects, which are
usually treated with specialized algorithms. A qualitative evaluation on the
dense semantic 3D reconstruction task shows that we improve significantly over
previous methods.


title:
Effective field theories for superconducting systems with multiple Fermi
  surfaces

abstract:
  In this work we investigate the description of superconducting systems with
multiple Fermi surfaces. For the case of one Fermi surface we re-obtain the
result that the superconductor is more precisely described as a topological
state of matter. Studying the case of more than one Fermi surface, we obtain
the effective theory describing a time reversal symmetric topological
superconductor. These results are obtained by employing a general procedure to
construct effective low energy actions describing states of electromagnetic
systems interacting with charges and defects. The procedure consists in taking
into account the proliferation or dilution of these charges and defects and its
consequences for the low energy description of the electromagnetic response of
the system. We find that the main ingredient entering the low energy
characterization of the system with more the one Fermi surface is a
non-conservation of the canonical supercurrent triggered by particular vortex
configurations.


title: Reasoning about Data Repetitions with Counter Systems

abstract:
  We study linear-time temporal logics interpreted over data words with
multiple attributes. We restrict the atomic formulas to equalities of attribute
values in successive positions and to repetitions of attribute values in the
future or past. We demonstrate correspondences between satisfiability problems
for logics and reachability-like decision problems for counter systems. We show
that allowing/disallowing atomic formulas expressing repetitions of values in
the past corresponds to the reachability/coverability problem in Petri nets.
This gives us 2EXPSPACE upper bounds for several satisfiability problems. We
prove matching lower bounds by reduction from a reachability problem for a
newly introduced class of counter systems. This new class is a succinct version
of vector addition systems with states in which counters are accessed via
pointers, a potentially useful feature in other contexts. We strengthen further
the correspondences between data logics and counter systems by characterizing
the complexity of fragments, extensions and variants of the logic. For
instance, we precisely characterize the relationship between the number of
attributes allowed in the logic and the number of counters needed in the
counter system.


title:
Non-linear variability in microquasars in relation with the winds from
  their accretion disks

abstract:
  The microquasar IGR J17091-3624, which is the recently discovered analogue of
the well known source GRS 1915+105, exhibits quasi-periodic outbursts, with a
period of 5-70 seconds, and regular amplitudes, referred to as "heartbeat
state". We argue that these states are plausibly explained by accretion disk
instability, driven by the dominant radiation pressure. Using our GLobal
Accretion DIsk Simulation hydrodynamical code, we model these outbursts
quantitatively. We also find a correlation between the presence of massive
outflows launched from the accretion disk and the stabilization of its
oscillations. We verify the theoretical predictions with the available timing
and spectral observations.
  Furthermore, we postulate that the underlying non-linear differential
equations that govern the evolution of an accretion disk are responsible for
the variability pattern of several other microquasars, including XTE J1550-564,
GX 339-4, and GRO J1655-40. This is based on the signatures of deterministic
chaos in the observed lightcurves of these sources, which we found using the
recurrence analysis method. We discuss these results in the frame of the
accretion disk instability model.


title: Origin of the Kohlrausch exponent

abstract:
  According to a recent numerical finding, the dynamics of a glass former is
exclusively due to the forces within the first coordination shell. This implies
that the Kohlrausch beta should be understandable in terms of the effective
nearest-neighbor potential.
  The present paper proposes a relation for the Kohlrausch beta based on the
Adam-Gibbs conjecture of a flow barrier proportional to the number of atoms or
molecules in a cooperatively rearranging region. The conjecture implies that
beta is given by the ratio of the structural entropy increase per particle to
the barrier increase per particle. Making use of a recent numerical
determination of the structural entropy per particle in Lennard-Jones-like
potentials, one can show that the relation leads to values between 0.3 and 0.6.


title:
Perpetual American options in diffusion-type models with running maxima
  and drawdowns

abstract:
  We study perpetual American option pricing problems in an extension of the
Black-Merton-Scholes model in which the dividend and volatility rates of the
underlying risky asset depend on the running values of its maximum and maximum
drawdown. The optimal exercise times are shown to be the first times at which
the underlying asset hits certain boundaries depending on the running values of
the associated maximum and maximum drawdown processes. We obtain closed-form
solutions to the equivalent free-boundary problems for the value functions with
smooth fit at the optimal stopping boundaries and normal reflection at the
edges of the state space of the resulting three-dimensional Markov process. The
optimal exercise boundaries for the perpetual American options on the maximum
of the market depth with fixed and floating strikes are determined as the
minimal solutions of certain first-order nonlinear ordinary differential
equations.


title: Density distributions in the $B$ meson

abstract:
  We report on a two-flavor lattice QCD study of the axial, charge and matter
distributions of the $B$ meson and its first radial excitation. As our
framework is the static limit of Heavy Quark Effective Theory (HQET), taking
their Fourier transform gives access to several form factors at the kinematical
point $q^2=0$. Moreover they provide some useful information on the nature of
an excited state, i.e. a radial excitation of a quark-antiquark bound state or
a multihadron state.


title: Distributed Technology-Sustained Pervasive Applications

abstract:
  Technology-sustained pervasive games, contrary to technology-supported
pervasive games, can be understood as computer games interfacing with the
physical world. Pervasive games are known to make use of 'non-standard input
devices' and with the rise of the Internet of Things (IoT), pervasive
applications can be expected to move beyond games. This dissertation is
requirements- and development-focused Design Science research for distributed
technology-sustained pervasive applications, incorporating knowledge from the
domains of Distributed Computing, Mixed Reality, Context-Aware Computing,
Geographical Information Systems and IoT. Computer video games have existed for
decades, with a reusable game engine to drive them. If pervasive games can be
understood as computer games interfacing with the physical world, can computer
game engines be used to stage pervasive games? Considering the use of
non-standard input devices in pervasive games and the rise of IoT, how will
this affect the architectures supporting the broader set of pervasive
applications? The use of a game engine can be found in some existing pervasive
game projects, but general research into how the domain of pervasive games
overlaps with that of video games is lacking. When an engine is used, a
discussion of, what type of engine is most suitable and what properties are
being fulfilled by the engine, is often not part of the discourse. This
dissertation uses multiple iterations of the method framework for Design
Science for the design and development of three software system architectures.
In the face of IoT, the problem of extending pervasive games into a fourth
software architecture, accommodating a broader set of pervasive applications,
is explicated. The requirements, for technology-sustained pervasive games, are
verified through the design, development and demonstration of the three
software system architectures. The ...


title:
Optical properties of an atomic ensemble coupled to a band edge of a
  photonic crystal waveguide

abstract:
  We study the optical properties of an ensemble of two-level atoms coupled to
a 1D photonic crystal waveguide (PCW), which mediates long-range coherent
dipole-dipole interactions between the atoms. We show that the long-range
interactions can dramatically alter the linear and nonlinear optical behavior,
as compared to a typical atomic ensemble. In particular, in the linear regime,
we find that the transmission spectrum reveals multiple transmission dips,
whose properties we show how to characterize. In the many-photon regime the
system response can be highly non-linear, and under certain circumstances the
ensemble can behave like a single two-level system, which is only capable of
absorbing and emitting a single excitation at a time. Our results are of direct
relevance to atom-PCW experiments that should soon be realizable.


title:
Integration based profile likelihood calculation for PDE constrained
  parameter estimation problems

abstract:
  Partial differential equation (PDE) models are widely used in engineering and
natural sciences to describe spatio-temporal processes. The parameters of the
considered processes are often unknown and have to be estimated from
experimental data. Due to partial observations and measurement noise, these
parameter estimates are subject to uncertainty. This uncertainty can be
assessed using profile likelihoods, a reliable but computationally intensive
approach. In this paper, we introduce an integration based approach for the
profile likelihood calculation for inverse problems with PDE constraints. While
existing approaches rely on repeated optimization, the proposed approach
exploits a dynamical system evolving along the likelihood profile. We derive
the dynamical system for the reduced and the full estimation problem and study
its properties. To evaluate the proposed method, we compare it with
state-of-the-art algorithms for a simple reaction-diffusion model for a
cellular patterning process. We observe a good accuracy of the method as well
as a significant speed up as compared to established methods. Integration based
profile calculation facilitates rigorous uncertainty analysis for
computationally demanding parameter estimation problems with PDE constraints.


title:
The StEllar Counterparts of COmpact high velocity clouds (SECCO) survey.
  II. Sensitivity of the survey and an Atlas of Synthetic Dwarf Galaxies

abstract:
  SECCO is a survey devoted to the search for stellar counterparts within Ultra
Compact High Velocity Clouds. In this contribution we present the results of a
set of simulations aimed at the quantitative estimate of the sensitivity of the
survey as a function of the total luminosity, size and distance of the stellar
systems we are looking for. For all our synthetic galaxies we assumed an
exponential surface brightness profile and an old and metal-poor population.
The synthetic galaxies are simulated both on the images and on the photometric
catalogs, taking into account all the observational effects. In the fields
where the available observational material is of the top quality we detect
synthetic galaxies as >=5 sigma over-densities of resolved stars down to
muV,h=30.0 mag/arcsec2, for D<=1.5 Mpc, and down to muV,h~29.5 mag/arcsec2, for
D<=2.5 Mpc. In the field with the worst observational material of the whole
survey we detect synthetic galaxies with muV,h<=28.8 mag/arcsec2 out to D<=1.0
Mpc, and those with muV,h<=27.5 mag/arcsec2 out to D<=2.5 Mpc. Dwarf galaxies
with MV=-10, with sizes in the range spanned by known dwarfs, are detected by
visual inspection of the images up to D=5 Mpc independently of the image
quality. In the best quality images dwarfs are partially resolved into stars up
to D=3.0 Mpc, and completely unresolved at D=5 Mpc. As an independent test of
the sensitivity of our images to low surface brightness galaxies we report on
the detection of several dwarf spheroidal galaxies probably located in the
Virgo cluster with MV<=-8.0 and muV,h<=26.8 mag/arcsec2. The nature of the
previously discovered SECCO 1 stellar system, also likely located in the Virgo
cluster, is re-discussed in comparison with these dwarfs. While specific for
the SECCO survey, our study may also provide general guidelines for detection
of faint stellar systems with 8m class telescopes.


title: Linear and algebraic independence of Generalized Euler-Briggs constants

abstract:
  Possible transcendental nature of Euler's constant $\gamma$ has been the
focus of study for sometime now. One possible approach is to consider $\gamma$
not in isolation, but as an element of the infinite family of generalised
Euler-Briggs constants. In a recent work \cite{GSS}, it is shown that the
infinite list of generalized Euler-Briggs constants can have at most one
algebraic number. In this paper, we study the dimension of spaces generated by
these generalized Euler-Briggs constants over number fields. More precisely, we
obtain non-trivial lower bounds (see \thmref{pre} and \thmref{linear-ind}) on
the dimension of these spaces and consequently establish the infinite
dimensionality of the space spanned. Further, we study linear and algebraic
independence of these constants over the field of all algebraic numbers.


title:
Obstacle problem for a class of parabolic equations of generalized
  $p$-Laplacian type

abstract:
  We study nonlinear parabolic PDEs with Orlicz-type growth conditions. The
main result gives the existence of a unique solution to the obstacle problem
related to these equations. To achieve this we show the boundedness of weak
solutions and that a uniformly bounded sequence of weak supersolutions
converges to a weak supersolution. Moreover, we prove that if the obstacle is
continuous, so is the solution.


title: Sparse Coding for Alpha Matting

abstract:
  Existing color sampling based alpha matting methods use the compositing
equation to estimate alpha at a pixel from pairs of foreground (F) and
background (B) samples. The quality of the matte depends on the selected (F,B)
pairs. In this paper, the matting problem is reinterpreted as a sparse coding
of pixel features, wherein the sum of the codes gives the estimate of the alpha
matte from a set of unpaired F and B samples. A non-parametric probabilistic
segmentation provides a certainty measure on the pixel belonging to foreground
or background, based on which a dictionary is formed for use in sparse coding.
By removing the restriction to conform to (F,B) pairs, this method allows for
better alpha estimation from multiple F and B samples. The same framework is
extended to videos, where the requirement of temporal coherence is handled
effectively. Here, the dictionary is formed by samples from multiple frames. A
multi-frame graph model, as opposed to a single image as for image matting, is
proposed that can be solved efficiently in closed form. Quantitative and
qualitative evaluations on a benchmark dataset are provided to show that the
proposed method outperforms current state-of-the-art in image and video
matting.


title:
Performance of a large size triple GEM detector at high particle rate
  for CBM Experiment at FAIR

abstract:
  In CBM Experiment at FAIR, dimuons will be detected by a Muon Chamber (MUCH)
consisting of segmented absorbers of varying widths and tracking chambers
sandwiched between the absorber-pairs. In this fixed target heavy-ion collision
experiment, operating at highest interaction rate of $10~MHz$ for $Au+Au$
collision, after the first MUCH detector station in its inner radial ring will
face a particle rate of $1~MHz/cm^2$. To operate at such a high particle
density, GEM technology based detectors have been selected for the first two
stations of MUCH. We have reported earlier the performance of several
small-size GEM detector prototypes built at VECC for use in MUCH. In this work,
we report on a large GEM chamber prototype tested with proton beam of momentum
$2.36~GeV/c$ at COSY-J\"{u}elich Germany. The detector was read out using
nXYTER ASIC operated in self-triggering mode. An efficiency higher than $96\%$
at $\Delta V_{GEM}~=~375.2~V$ was achieved. The variation of efficiency with
the rate of incoming protons has been found to vary within $2\%$ when tested up
to a maximum rate of $2.8~MHz/cm^2$. The gain was found to be stable at high
particle rate with a maximum variation of $\sim~9\%$.


title:
Inhomogeneous distribution of particles and temperature in
  self-gravitating system

abstract:
  Self-gravitating system are non-equilibrium a priory. A new approach is
proposed, which employs a non-equilibrium statistical operator into account
inhomogeneous distribution of particles and temperature. The method involves
the saddle - point procedure to find the dominant contribution to the partition
function and thus to obtain all thermodynamic parameters of the system.
Probable peculiar features in the behavior of self-gravitating system are
considered for various condition. The equation of state for self-gravitating
system has been obtained. A new length of statistical instability and parameter
of the spatial inhomogeneous distribution of particles and temperature are
obtained for real gravitating system.


title: New Strong Converse for Asymmetric Broadcast Channels

abstract:
  We consider the discrete memoryless asymmetric broadcast channels. We prove
that the error probability of decoding tends to one exponentially for rates
outside the capacity region and derive an explicit lower bound of this exponent
function. We shall demonstrate that the information spectrum approach is quite
useful for investigating this problem.


title: Statistics of RGBD Images

abstract:
  Cameras that can measure the depth of each pixel in addition to its color
have become easily available and are used in many consumer products worldwide.
Often the depth channel is captured at lower quality compared to the RGB
channels and different algorithms have been proposed to improve the quality of
the D channel given the RGB channels. Typically these approaches work by
assuming that edges in RGB are correlated with edges in D.
  In this paper we approach this problem from the standpoint of natural image
statistics. We obtain examples of high quality RGBD images from a computer
graphics generated movie (MPI-Sintel) and we use these examples to compare
different probabilistic generative models of RGBD image patches. We then use
the generative models together with a degradation model and obtain a Bayes
Least Squares (BLS) estimator of the D channel given the RGB channels. Our
results show that learned generative models outperform the state-of-the-art in
improving the quality of depth channels given the color channels in natural
images even when training is performed on artificially generated images.


title: Soft-wall modelling of meson spectra

abstract:
  The holographic methods inspired by the gauge/gravity correspondence from
string theory have been actively applied to the hadron spectroscopy in the last
eleven years. Within the phenomenological bottom-up approach, the linear
Regge-like trajectories for light mesons are naturally reproduced in the
so-called "Soft-wall" holographic models. I will give a very short review of
the underlying ideas and technical aspects related to the meson spectroscopy. A
generalization of soft-wall description of Regge trajectories to arbitrary
intercept is proposed. The problem of incorporation of the chiral symmetry
breaking is discussed.


title: Multi-Meson Model applied to $D^+ \to K^+ K^- K^+$

abstract:
  Matrix elements of weak currents involving light multi-meson states are
important in many hadronic decays of both heavy leptons and heavy mesons. In
this paper we focus on the latter case where the current size of the data set
demands better models. The specific case of three-kaon weak matrix elements is
considered and expressed as a relatively simple structure, which generalizes
naturally the concept of form factor. We propose a model for the decay $D^+ \to
K^+ K^- K^+$ as an alternative to isobar model, with free parameter predicted
by the theory to be fine-tuned by a fit to data. An important qualitative
outcome is that we encompass naturally all final states topologies, which
involve necessarily proper multi-particle structures and cannot be decomposed
into simpler two-body processes. This aspect represents a significant
improvement when compared to isobar model, often employed in analyses of
heavy-meson decay data.


title:
Effect of moir\'e superlattice reconstruction in the electronic
  excitation spectrum of graphene-metal heterostructures

abstract:
  We have studied the electronic excitation spectrum in periodically rippled
graphene on Ru(0001) and flat, commensurate graphene on Ni(111) by means of
high-resolution electron energy loss spectroscopy and a combination of density
functional theory and tight-binding approaches. We show that the periodic
moir\'e superlattice originated by the lattice mismatch in graphene/Ru(0001)
induces the emergence of an extra mode, which is not present in
graphene/Ni(111). Contrary to the ordinary intra-band plasmon of doped
graphene, the extra mode is robust in charge-neutral graphene/metal contacts,
having its origin in electron-hole inter-band transitions between van Hove
singularities that emerge in the reconstructed band structure, due to the
moir\'e pattern superlattice.


title: The vulnerability of the diameter of enhanced hypercubes

abstract:
  For an interconnection network $G$, the {\it $\omega$-wide diameter}
$d_\omega(G)$ is the least $\ell$ such that any two vertices are joined by
$\omega$ internally-disjoint paths of length at most $\ell$, and the {\it
$(\omega-1)$-fault diameter} $D_{\omega}(G)$ is the maximum diameter of a
subgraph obtained by deleting fewer than $\omega$ vertices of $G$.
  The enhanced hypercube $Q_{n,k}$ is a variant of the well-known hypercube.
Yang, Chang, Pai, and Chan gave an upper bound for $d_{n+1}(Q_{n,k})$ and
$D_{n+1}(Q_{n,k})$ and posed the problem of finding the wide diameters and
fault diameters of $Q_{n,k}$. By constructing internally disjoint paths between
any two vertices in the enhanced hypercube, for $n\ge3$ and $2\le k\le n$ we
prove $$ D_\omega(Q_{n,k})=d_\omega(Q_{n,k})=\begin{cases} d(Q_{n,k}) &
\textrm{for $1 \leq \omega < n-\lfloor\frac{k}{2}\rfloor$;}\\ d(Q_{n,k})+1 &
\textrm{for $n-\lfloor\frac{k}{2}\rfloor \leq \omega \leq n+1$.} \end{cases} $$
where $d(Q_{n,k})$ is the diameter of $Q_{n,k}$. These results mean that
interconnection networks modelled by enhanced hypercubes are extremely robust.


title:
Modeling and predicting measured response time of cloud-based web
  services using long-memory time series

abstract:
  Predicting cloud performance from user's perspective is a complex task,
because of several factors involved in providing the service to the consumer.
In this work, the response time of 10 real-world services is analyzed. We have
observed long memory in terms of the measured response time of the
CPU-intensive services and statistically verified this observation using
estimators of the Hurst exponent. Then, na\"ive, mean, autoregressive
integrated moving average (ARIMA) and autoregressive fractionally integrated
moving average (ARFIMA) methods are used to forecast the future values of
quality of service (QoS) at runtime. Results of the cross-validation over the
10 datasets show that the long-memory ARFIMA model provides the mean of 37.5 %
and the maximum of 57.8 % reduction in the forecast error when compared to the
short-memory ARIMA model according to the standard error measure of mean
absolute percentage error. Our work implies that consideration of the
long-range dependence in QoS data can help to improve the selection of services
according to their possible future QoS values.


title: Degree-associated edge-reconstruction numbers of double-brooms

abstract:
  An edge-deleted subgraph of a graph $G$ is an {\it edge-card}. A {\it decard}
consists of an edge-card and the degree of the missing edge. The {\it
degree-associated edge-reconstruction number} of a graph $G$, denoted
$\dern(G)$, is the minimum number of decards that suffice to reconstruct $G$.
The {\it adversary degree-associated edge-reconstruction number} $\adern(G)$ is
the least $k$ such that every set of $k$ decards determines $G$. We determine
these two parameters for all double-brooms. The answer is usually $1$ for
$\dern(G)$, and $2$ for $\adern(G)$ when $G$ is double-broom. But there are
exceptions in each case.


title:
Robust Individual Circadian Parameter Estimation for Biosignal-based
  Personalisation of Cancer Chronotherapy

abstract:
  In cancer treatment, chemotherapy is administered according a constant
schedule. The chronotherapy approach, considering chronobiological drug
delivery, adapts the chemotherapy profile to the circadian rhythms of the human
organism. This reduces toxicity effects and at the same time enhances
efficiency of chemotherapy. To personalize cancer treatment, chemotherapy
profiles have to be further adapted to individual patients. Therefore, we
present a new model to represent cycle phenomena in circadian rhythms. The
model enables a more precise modelling of the underlying circadian rhythms. In
comparison with the standard model, our model delivers better results in all
defined quality indices. The new model can be used to adapt the chemotherapy
profile efficiently to individual patients. The adaption to individual patients
contributes to the aim of personalizing cancer therapy.


title: Deep Gate Recurrent Neural Network

abstract:
  This paper introduces two recurrent neural network structures called Simple
Gated Unit (SGU) and Deep Simple Gated Unit (DSGU), which are general
structures for learning long term dependencies. Compared to traditional Long
Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU), both structures
require fewer parameters and less computation time in sequence classification
tasks. Unlike GRU and LSTM, which require more than one gates to control
information flow in the network, SGU and DSGU only use one multiplicative gate
to control the flow of information. We show that this difference can accelerate
the learning speed in tasks that require long dependency information. We also
show that DSGU is more numerically stable than SGU. In addition, we also
propose a standard way of representing inner structure of RNN called RNN
Conventional Graph (RCG), which helps analyzing the relationship between input
units and hidden units of RNN.


title:
Inner amenability, property Gamma, McDuff II_1 factors and stable
  equivalence relations

abstract:
  We say that a countable group $G$ is McDuff if it admits a free ergodic
probability measure preserving action such that the crossed product is a McDuff
II_1 factor. Similarly, $G$ is said to be stable if it admits such an action
with the orbit equivalence relation being stable. The McDuff property,
stability, inner amenability and property Gamma are subtly related and several
implications and non implications were obtained in
[Ef73,JS85,Va09,Ki12a,Ki12b]. We complete the picture with the remaining
implications and counterexamples.


title:
Study of the Pion-Nucleon Coupling Constant Charge Dependence on the
  Basis of the Low-Energy Data on Nucleon-Nucleon Interaction

abstract:
  We study relationship between the physical quantities that characterize
pion-nucleon and nucleon-nucleon interaction on the basis of the fact that
nuclear forces in the nucleon-nucleon system at low energies are mainly
determined by the one-pion exchange mechanism. By making use of the recommended
proton-proton low-energy scattering parameters, we obtain the following value
for the charged pion-nucleon coupling constant g$_{\pi ^{\pm }}^{2}/4\pi
=14.55(13)$. Calculated value of this quantity is in excellent agreement with
the experimental result g$_{\pi ^{\pm }}^{2}/4\pi =14.52(26)$ of the Uppsala
Neutron Research Group. At the same time, the obtained value of the charged
pion-nucleon coupling constant differs markedly from the value of the neutral
pion-nucleon coupling constant g$_{\pi ^{0}}^{2}/4\pi =13.55(13)$. Thus, our
results show considerable charge splitting of the pion-nucleon coupling
constant.


title: Novel third-order Lovelock wormhole solutions

abstract:
  In this work, we consider wormhole geometries in third-order Lovelock gravity
and investigate the possibility that these solutions satisfy the energy
conditions. In this framework, by applying a specific equation of state, we
obtain exact wormhole solutions, and by imposing suitable values for the
parameters of the theory, we find that these geometries satisfy the weak energy
condition in the vicinity of the throat, due to the presence of higher order
curvature terms. Finally, we trace out a numerical analysis, by assuming a
specific redshift function, and find asymptotically flat solutions that satisfy
the weak energy condition throughout the spacetime.


title:
A Study on the Electrode Protection System of an 100t Ultra High Power
  Electric Furnace

abstract:
  In this paper a method to design the electrode protection system using arc
current and voltage and pressure inside the hydraulic cylinder of electrode
lift device of an 100t ultra high power furnace (UHP furnace) and confident
factor(CF) and Lyapnov function, and then we validated our method through the
field experimentation.


title: Notes on the ambitwistor pure spinor string

abstract:
  In this work, some aspects of the ambitwistor pure spinor string are
investigated. The $b$ ghost is presented and its main properties are derived in
a simple way, very similar to the usual pure spinor $b$ ghost construction. The
heterotic case is also addressed with a new proposal for the BRST charge. The
BRST cohomology is shown to correctly describe the heterotic supergravity
spectrum and a semi-composite $b$ ghost is constructed.


title:
$\mu$SR Insight into the Impurity Problem in Quantum Kagome
  Antiferromagnets

abstract:
  Impurities, which are inherently present in any real material, may play an
important role in the magnetism of frustrated spin systems with spin-liquid
ground states. We address the impurity issue in quantum kagome antiferromagnets
by investigating ZnCu$_3$(OH)$_6$SO$_4$ (Zn-brochantite) by means of muon spin
spectroscopy. We show that muons couple to the impurity magnetism, originating
from Cu-Zn intersite disorder, and that the impurities are highly correlated
with the kagome spins, allowing us to probe the intrinsic kagome physics via a
Kondo-like effect. The low-temperature plateau in local susceptibility
identifies the spin-liquid ground state as being gapless. The corresponding
spin fluctuations exhibit an unconventional spectral density and an intriguing
field dependence.


title:
Gaussian Process Domain Experts for Model Adaptation in Facial Behavior
  Analysis

abstract:
  We present a novel approach for supervised domain adaptation that is based
upon the probabilistic framework of Gaussian processes (GPs). Specifically, we
introduce domain-specific GPs as local experts for facial expression
classification from face images. The adaptation of the classifier is
facilitated in probabilistic fashion by conditioning the target expert on
multiple source experts. Furthermore, in contrast to existing adaptation
approaches, we also learn a target expert from available target data solely.
Then, a single and confident classifier is obtained by combining the
predictions from multiple experts based on their confidence. Learning of the
model is efficient and requires no retraining/reweighting of the source
classifiers. We evaluate the proposed approach on two publicly available
datasets for multi-class (MultiPIE) and multi-label (DISFA) facial expression
classification. To this end, we perform adaptation of two contextual factors:
'where' (view) and 'who' (subject). We show in our experiments that the
proposed approach consistently outperforms both source and target classifiers,
while using as few as 30 target examples. It also outperforms the
state-of-the-art approaches for supervised domain adaptation.


title:
Asymptotic expansion of stationary distribution for reflected Brownian
  motion in the quarter plane via analytic approach

abstract:
  Brownian motion in R 2 + with covariance matrix $\Sigma$ and drift $\mu$ in
the interior and reflection matrix R from the axes is considered. The
asymptotic expansion of the stationary distribution density along all paths in
R 2 + is found and its main term is identified depending on parameters
($\Sigma$, $\mu$, R). For this purpose the analytic approach of Fayolle,
Iasnogorodski and Malyshev in [12] and [36], restricted essentially up to now
to discrete random walks in Z 2 + with jumps to the nearest-neighbors in the
interior is developed in this article for diffusion processes on R 2 + with
reflections on the axes.


title:
Noise Processing by MicroRNA-Mediated Circuits: the Incoherent
  Feed-Forward Loop, Revisited

abstract:
  The intrinsic stochasticity of gene expression is usually mitigated in higher
eukaryotes by post-transcriptional regulation channels that stabilise the
output layer, most notably protein levels. The discovery of small non-coding
RNAs (miRNAs) in specific motifs of the genetic regulatory network has led to
identifying noise buffering as the possible key function they exert in
regulation. Recent in vitro} and in silico studies have corroborated this
hypothesis. It is however also known that miRNA-mediated noise reduction is
hampered by transcriptional bursting in simple topologies. Here, using
stochastic simulations validated by analytical calculations based on van
Kampen's expansion, we revisit the noise-buffering capacity of the
miRNA-mediated Incoherent Feed Forward Loop (IFFL), a small module that is
widespread in the gene regulatory networks of higher eukaryotes, in order to
account for the effects of intermittency in the transcriptional activity of the
modulator gene. We show that bursting considerably alters the circuit's ability
to control static protein noise. By comparing with other regulatory
architectures, we find that direct transcriptional regulation significantly
outperforms the IFFL in a broad range of kinetic parameters. This suggests
that, under pulsatile inputs, static noise reduction may be less important than
dynamical aspects of noise and information processing in characterising the
performance of regulatory elements.


title:
The spin relaxation of nitrogen donors in 6H SiC crystals as studied by
  the electron spin echo method

abstract:
  We present the detailed study of the spin kinetics of the nitrogen (N) donor
electrons in 6H SiC wafers grown by Lely method and by sublimation "sandwich
method" (SSM) with a donor concentration of about 10^17 cm^-3 at T = 10-40 K.
The donor electrons of the N donors substituting quasi-cubic "k1" and "k2"
sites (Nk1,k2) in both types of the samples revealed the similar temperature
dependence of the spin-lattice relaxation rate (T1^-1), which was described by
the direct one-phonon and two-phonon processes induced by the acoustic phonons
proportional to T and to T^9, respectively. The character of the temperature
dependence of the T1^-1 for the donor electrons of N substituting hexagonal
("h") site (Nh) in both types of 6H SiC samples indicates that the donor
electrons relax through the fast-relaxing centers by means of the
cross-relaxation process. The observed enhancement of the phase memory
relaxation rate (Tm^-1) with the temperature increase for the Nh donors in both
types of the samples, as well as for the Nk1,k2 donors in Lely grown 6H SiC,
was explained by the growth of the free electron concentration with the
temperature increase and their exchange scattering at the N donor centers. The
observed significant shortening of the phase memory relaxation time Tm for the
Nk1,k2 donors in the SSM grown sample with the temperature lowering is caused
by hopping motion of the electrons between the occupied and unoccupied states
of the N donors at Nh and Nk1,k2 sites. The impact of the N donor pairs,
triads, distant donor pairs formed in n-type 6H SiC wafers on the spin
relaxation times was discussed.


title: Doubling of the critical temperature of FeSe observed in point contacts

abstract:
  Rise in superconducting critical temperature Tc more than two times
(exceeding 20 K) is discov- ered in point-contacts created between
iron-chalcogenide FeSe single crystal and Cu. The possible reasons of such Tc
increase in point-contacts are discussed. The most probable cause for this may
be the interfacial carriers doping and/or interfacial enhanced electron-phonon
interaction.


title:
Double-polarization observable G in neutral-pion photoproduction off the
  proton

abstract:
  This paper reports on a measurement of the double-polarization observable G
in $\pi^0$ photoproduction off the proton using the CBELSA/TAPS experiment at
the ELSA accelerator in Bonn. The observable G is determined from reactions of
linearly-polarized photons with longitudinally-polarized protons. The polarized
photons are produced by bremsstrahlung off a properly oriented diamond
radiator. A frozen spin butanol target provides the polarized protons. The data
cover the photon energy range from 617 to 1325 MeV and a wide angular range.
The experimental results for G are compared to predictions by the Bonn-Gatchina
(BnGa), J\"ulich-Bonn (J\"uBo), MAID and SAID partial wave analyses.
Implications of the new data for the pion photoproduction multipoles are
discussed.


title: Free nilpotent and nilpotent quadratic Lie algebras

abstract:
  In this paper we introduce an equivalence between the category of the
t-nilpotent quadratic Lie algebras with d generators and the category of some
symmetric invariant bilinear forms on the t-nilpotent free Lie algebra with d
generators. Taking into account this equivalence, t-nilpotent quadratic Lie
algebras with d generators are classified (up to isometric isomorphism, and
over any field of characteristic zero), in the following cases: d=2 and t<6,
d=3 and t<4.


title:
Particle Acceleration during Magnetic Reconnection in a Low-beta Pair
  Plasma

abstract:
  Plasma energization through magnetic reconnection in the
magnetically-dominated regime featured by low plasma beta ($\beta = 8 \pi
nkT_0/B^2 \ll 1$) and/or high magnetization ($\sigma = B^2/(4 \pi nmc^2) \gg
1$) is important in a series of astrophysical systems such as solar flares,
pulsar wind nebula, and relativistic jets from black holes, etc. In this paper,
we review the recent progress on kinetic simulations of this process and
further discuss plasma dynamics and particle acceleration in a low-$\beta$
reconnection layer that consists of electron-positron pairs. We also examine
the effect of different initial thermal temperatures on the resulting particle
energy spectra. While earlier papers have concluded that the spectral index is
smaller for higher $\sigma$, our simulations show that the spectral index
approaches $p=1$ for sufficiently low plasma $\beta$, even if $\sigma \sim 1$.
Since this predicted spectral index in the idealized limit is harder than most
observations, it is important to consider effects that can lead to a softer
spectrum such as open boundary simulations. We also remark that the effects of
3D reconnection physics and turbulence on reconnection need to be addressed in
the future.

categories: astro-ph.HE astro-ph.SR physics.plasm-ph physics.space-ph


title:
Multicarrier PAPR Reduction by Iteratively Shifting and Concentrating
  the Probability Measure

abstract:
  The peak power problem in multicarrier waveforms is well-known and imposes
substantial limitations on wireless communications. As the quest for
investigation of enabling technologies for the next generation of wireless
communication systems 5G is at its peak, the problem is re-emerging in a much
broader range of technologies. However, despite numerous publications on the
topic, there is no well-established structure available for the problem, which
motivates a boost in research. In this paper, a novel peak power reduction
algorithm is proposed which offers a substantial Peak-to-Average Power Ratio
(PAPR) reduction and exhibits high potential for further refinements.
Mathematical tractability of the algorithm is expected to be of particular
importance to this end. A remarkable early observation is a PAPR reduction of
about 4.5 dB for 64 subcarriers with a rate loss of 0.5 bits per complex data
symbol in an OFDM scheme, which is half the rate loss that other methods
require in this class of algorithms.


title: 2-Groups, 2-Characters, and Burnside Rings

abstract:
  We study 2-representations, i.e., actions of 2-groups on 2-vector spaces. Our
main focus is character theory for 2-representations. To this end we employ the
technique of extended Burnside rings. Our main theorem is that the
Ganter-Kapranov 2-character is a particular mark homomorphism of the Burnside
ring. As an application we give a new proof of Osorno formula for the
Ganter-Kapranov 2-character of a finite group.


title: Strong entropic uncertainty relations for multiple measurements

abstract:
  In this paper, we study entropic uncertainty relations on a
finite-dimensional Hilbert space and provide several tighter bounds for
multi-measurements, with some of them also valid for R\'{e}nyi and Tsallis
entropies besides the Shannon entropy. We employ majorization theory and
actions of the symmetric group to obtain an {\it admixture bound} for entropic
uncertainty relations for multi-measurements. Comparisons among all bounds for
multi-measurements are shown in figures in our favor.


title: Equivariant adjusted least squares estimator in two-line fitting model

abstract:
  We consider the two-line fitting problem. True points lie on two straight
lines and are observed with Gaussian perturbations. For each observed point, it
is not known on which line the corresponding true point lies. The parameters of
the lines are estimated. This model is a restriction of the conic section
fitting model because a couple of two lines is a degenerate conic section. The
following estimators are constructed: two projections of the adjusted least
squares estimator in the conic section fitting model, orthogonal regression
estimator, parametric maximum likelihood estimator in the Gaussian model, and
regular best asymptotically normal moment estimator. The conditions for the
consistency and asymptotic normality of the projections of the adjusted least
squares estimator are provided. All the estimators constructed in the paper are
equivariant. The estimators are compared numerically.


title: Solving Optimization Problems by the Public Goods Game

abstract:
  We introduce a method based on the Public Goods Game for solving optimization
tasks. In particular, we focus on the Traveling Salesman Problem, i.e. a
NP-hard problem whose search space exponentially grows increasing the number of
cities. The proposed method considers a population whose agents are provided
with a random solution to the given problem. In doing so, agents interact by
playing the Public Goods Game using the fitness of their solution as currency
of the game. Notably, agents with better solutions provide higher
contributions, while those with lower ones tend to imitate the solution of
richer agents for increasing their fitness. Numerical simulations show that the
proposed method allows to compute exact solutions, and suboptimal ones, in the
considered search spaces. As result, beyond to propose a new heuristic for
combinatorial optimization problems, our work aims to highlight the
potentiality of evolutionary game theory beyond its current horizons.


title:
Implementation of haptic communication in comanipulative tasks: a
  statistical state machine model

abstract:
  - This paper presents an experimental evaluation of physical human-human
interaction in lightweight condition using a one degree of freedom robotized
setup. It explores possible origins of Physical Human-Human communication, more
precisely, the hypothesis of a time based communication. To explore if the
communication is correlated to time a statistical state machine model based on
physical Human-Human interaction is proposed. The model is tested with 14
subjects and presents results that are close to human-human performances.


title:
Circular CNOT Circuits: Definition, Analysis and Application to
  Fault-Tolerant Quantum Circuits

abstract:
  The work proposes an extension of the quantum circuit formalism where qubits
(wires) are circular instead of linear. The left-to-right interpretation of a
quantum circuit is replaced by a circular representation which allows to select
the starting point and the direction in which gates are executed. The
representation supports all the circuits obtained after computing cyclic
permutations of an initial quantum gate list. Two circuits, where one has a
gate list which is a cyclic permutation of the other, will implement different
functions. The main question appears in the context of scalable quantum
computing, where multiple subcircuits are used for the construction of a larger
fault-tolerant one: can the same circular representation be used by multiple
subcircuits? The circular circuits are sufficient for constructing
computationally universal, fault-tolerant circuits formed entirely of qubit
initialisation, CNOT gates and qubit measurements. The main result of modelling
circular CNOT circuits is that a derived Boolean representation allows to
define a set of equations for $X$ and $Z$ stabiliser transformations. Through a
well defined set of steps it is possible to reduce the initial equations to a
set of stabiliser transformations given a series of cuts through the circular
circuit.


title: On the quasisymmetric H\"older-equivalence problem for Carnot groups

abstract:
  A variant of Gromov's H{\"o}lder-equivalence problem, motivated by a pinching
problem in Riemannian geometry, is discussed. A partial result is given. The
main tool is a general coarea inequality satisfied by packing energies of maps.


title:
A class of square-free monomial ideals associated to two integer
  sequences

abstract:
  Given two finite sequences of positive integers $\alpha$ and $\beta$, we
associate a square free monomial ideal $I_{\alpha,\beta}$ in a ring of
polynomials $S$, and we recursively compute the algebraic invariants of
$S/I_{\alpha,\beta}$. Also, we give precise formulas in special cases.


title: Solving the Team Orienteering Problem with Cutting Planes

abstract:
  The Team Orienteering Problem (TOP) is an attractive variant of the Vehicle
Routing Problem (VRP). The aim is to select customers and at the same time
organize the visits for a vehicle fleet so as to maximize the collected profits
and subject to a travel time restriction on each vehicle. In this paper, we
investigate the effective use of a linear formulation with polynomial number of
variables to solve TOP. Cutting planes are the core components of our solving
algorithm. It is first used to solve smaller and intermediate models of the
original problem by considering fewer vehicles. Useful information are then
retrieved to solve larger models, and eventually reaching the original problem.
Relatively new and dedicated methods for TOP, such as identification of
irrelevant arcs and mandatory customers, clique and independent-set cuts based
on the incompatibilities, and profit/customer restriction on subsets of
vehicles, are introduced. We evaluated our algorithm on the standard benchmark
of TOP. The results show that the algorithm is competitive and is able to prove
the optimality for 12 instances previously unsolved.


title:
Adding Semantic Information into Data Models by Learning Domain
  Expertise from User Interaction

abstract:
  Interactive visual analytic systems enable users to discover insights from
complex data. Users can express and test hypotheses via user interaction,
leveraging their domain expertise and prior knowledge to guide and steer the
analytic models in the system. For example, semantic interaction techniques
enable systems to learn from the user's interactions and steer the underlying
analytic models based on the user's analytical reasoning. However, an open
challenge is how to not only steer models based on the dimensions or features
of the data, but how to add dimensions or attributes to the data based on the
domain expertise of the user. In this paper, we present a technique for
inferring and appending dimensions onto the dataset based on the prior
expertise of the user expressed via user interactions. Our technique enables
users to directly manipulate a spatial organization of data, from which both
the dimensions of the data are weighted, and also dimensions created to
represent the prior knowledge the user brings to the system. We describe this
technique and demonstrate its utility via a use case.


title: Generalized Lagrangian mean curvature flows: the cotangent bundle case

abstract:
  In [SW2], we defined a generalized mean curvature vector field on any almost
Lagrangian submanifold with respect to a torsion connection on an almost
K\"ahler manifold. The short time existence of the corresponding parabolic flow
was established. In addition, it was shown that the flow preserves the
Lagrangian condition as long as the connection satisfies an Einstein condition.
In this article, we show that the canonical connection on the cotangent bundle
of any Riemannian manifold is an Einstein connection (in fact, Ricci flat). The
generalized mean curvature vector on any Lagrangian submanifold is related to
the Lagrangian angle defined by the phase of a parallel (n, 0) form, just like
the Calabi-Yau case. We also show that the corresponding Lagrangian mean
curvature flow in cotangent bundles preserves the exactness and the zero Maslov
class conditions. At the end, we prove a long time existence and convergence
result to demonstrate the stability of the zero section of the cotangent bundle
of spheres.


title:
PERCCOM: A Master Program in Pervasive Computing and COMmunications for
  Sustainable Development

abstract:
  This paper presents the Erasmus Mundus Joint Master Degree in Pervasive
Computing and Communications for Sustainable Development (PERCCOM). This
program brings together 11 academic partners and 8 industry partners to combine
advanced Information and Communication Technologies (ICT) with environmental
awareness to enable world-class education and unique competences for ICT
professionals who can build cleaner, greener, more resource and energy
efficient cyber-physical systems. First, this paper describes the rationale and
motivations for ICT education for sustainability challenges. It then details
the structure and contents of the programs including the courses offered at the
three teaching locations (Nancy France, Lappeenranta Finland, and Lulea
Sweden). The ways that the program has been running as well as students
selection, their thesis works, involvement of industry, are also discussed. The
program was built and managed using a solid academic standards and strategies
student-centered learning.


title: Flawlessness of $h$-vectors of broken circuit complexes

abstract:
  One of the major open questions in matroid theory asks whether the $h$-vector
$(h_0,h_1,\ldots,h_s)$ of the broken circuit complex of a matroid $M$ satisfies
the following inequalities: $$ h_0\leq h_1\leq \cdots\leq h_{\lfloor
s/2\rfloor} \quad \text{and}\qua h_i\le h_{s-i}\ \text{ for }\ 0\leq i \leq
\lfloor s/2\rfloor. $$ This paper affirmatively answers the question for
matroids that are representable over a field of characteristic zero.


title: On O'Grady's generalized Franchetta conjecture

abstract:
  We study relative zero cycles on the universal polarized $K3$ surface $X \to
\mathcal{F}_g$ of degree $2g - 2$. It was asked by O'Grady if the restriction
of any class in $\mathrm{CH}^2(X)$ to a closed fiber $X_s$ is a multiple of the
Beauville-Voisin canonical class $c_{X_s} \in \mathrm{CH}_0(X_s)$. Using Mukai
models, we give an affirmative answer to this question for $g \leq 10$ and $g =
12, 13, 16, 18, 20$.


title:
Topological phase transition and quantum spin Hall edge states of
  antimony few layers

abstract:
  While two-dimensional topological insulators (2D TI) initiated the field of
topological materials, only very few materials were discovered to date and the
direct access to their quantum spin Hall edge states has been challenging due
to material issues. Here, we introduce a new 2D TI material, Sb few layer
films. Electronic structures of ultrathin Sb islands grown on Bi2Te2Se are
investigated by scanning tunneling microscopy. The maps of local density of
states clearly identify robust edge electronic states over the thickness of
three bilayers in clear contrast to thinner islands. This indicates the
topological edge states emerged through a 2D topological phase transition
predicted between three and four bilayer films in recent theory. The
non-trivial phase transition and edge states are confirmed for epitaxial films
by extensive density-functional-theory calculations. This work provides an
important material platform to exploit miscroscopic aspects of the quantum spin
Hall phase and its quantum phase transition.


title: Mixing in modulated turbulence. Numerical results

abstract:
  Direct numerical simulations are carried out to investigate scalar mixing in
an isotropic turbulent flow with a time-periodic forcing. For high amplitudes
of the modulation, it is shown that the average mixing rate is negatively
affected at low frequencies. In this limit the mixing time scale increases,
whereas the typical velocity timescale decreases. We further determine the
frequency response of scalar statistics to a periodic scalar-forcing.


title:
The Stacked Lyman-Alpha Emission Profile from the Circum-Galactic Medium
  of z~2 Quasars

abstract:
  In the context of the FLASHLIGHT survey, we obtained deep narrow band images
of 15 $z\sim2$ quasars with GMOS on Gemini-South in an effort to measure
Ly$\alpha$ emission from circum- and inter-galactic gas on scales of hundreds
of kpc from the central quasar. We do not detect bright giant Ly$\alpha$
nebulae (SB~10$^{-17}$ erg s$^{-1}$ cm$^{-2}$ arcsec$^{-2}$ at distances >50
kpc) around any of our sources, although we routinely ($\simeq47$%) detect
smaller scale <50 kpc Ly$\alpha$ emission at this SB level emerging from either
the extended narrow emission line regions powered by the quasars or by
star-formation in their host galaxies. We stack our 15 deep images to study the
average extended Ly$\alpha$ surface brightness profile around $z\sim2$ quasars,
carefully PSF-subtracting the unresolved emission component and paying close
attention to sources of systematic error. Our analysis, which achieves an
unprecedented depth, reveals a surface brightness of SB$_{\rm
Ly\alpha}\sim10^{-19}$ erg s$^{-1}$ cm$^{-2}$ arcsec$^{-2}$ at $\sim200$ kpc,
with a $2.3\sigma$ detection of Ly$\alpha$ emission at SB$_{\rm
Ly\alpha}=(5.5\pm3.1)\times10^{-20}$ erg s$^{-1}$ cm$^{-2}$ arcsec$^{-2}$
within an annulus spanning 50 kpc <R< 500 kpc from the quasars. Assuming this
Ly$\alpha$ emission is powered by fluorescence from highly ionized gas
illuminated by the bright central quasar, we deduce an average volume density
of $n_{\rm H}=0.6\times10^{-2}$ cm$^{-3}$ on these large scales. Our results
are in broad agreement with the densities suggested by cosmological
hydrodynamical simulations of massive ($M\simeq10^{12.5}M_\odot$) quasar hosts,
however they indicate that the typical quasars at these redshifts are
surrounded by gas that is a factor of ~100 times less dense than the (~1
cm$^{-3}$) gas responsible for the giant bright Ly$\alpha$ nebulae around
quasars recently discovered by our group.


title:
Taming mismatches in inter-agent distances for the formation-motion
  control of second-order agents

abstract:
  This paper presents the analysis on the influence of distance mismatches on
the standard gradient-based rigid formation control for second-order agents. It
is shown that, similar to the first-order case as recently discussed in the
literature, these mismatches introduce two undesired group behaviors: a
distorted final shape and a steady-state motion of the group formation. We show
that such undesired behaviors can be eliminated by combining the standard
formation control law with distributed estimators. Finally, we show how the
mismatches can be effectively employed as design parameters in order to control
a combined translational and rotational motion of the formation.


title: Au-Ag-Cu nano-alloys: tailoring of permittivity

abstract:
  Precious metal alloys enables new possibilities to tailor materials for
specific optical functions. Here we present a systematic study of the effects
of a nanoscale alloying on the permittivity of Au-Ag-Cu metals at 38 different
atomic mixing ratios. The permittivity was measured and analyzed numerically by
applying the Drude model. X-ray diffraction (XRD) revealed the face centered
cubic lattice of the alloys. Both, optical spectra and XRD results point
towards an equivalent composition-dependent electron scattering behavior.
Correlation between the fundamental structural parameters of alloys and the
resulting optical properties is elucidated. Plasmonic properties of the
Au-Ag-Cu alloy nanoparticles were investigated by numerical simulations.
Guidelines for designing plasmonic response of nano- structures and their
patterns are presented from the material science perspective.


title: Fillings of genus-1 open books and 4-braids

abstract:
  We show that there are contact 3-manifolds of support genus one which admit
infinitely many Stein fillings, but do not admit arbitrarily large ones. These
Stein fillings arise from genus-1 allowable Lefschetz fibrations with distinct
homology groups, all filling a fixed minimal genus open book supporting the
boundary contact 3-manifold. In contrast, we observe that there are only
finitely many possibilities for the homology groups of Stein fillings of a
given contact 3-manifold with support genus zero. We also show that there are
4-strand braids which admit infinitely many distinct Hurwitz classes of
quasipositive factorizations, yielding in particular an infinite family of
knotted complex analytic annuli in the 4-ball bounding the same transverse link
up to transverse isotopy. These realize the smallest possible examples in terms
of the number of boundary components a genus-1 mapping class and the number of
strands a braid can have with infinitely many positive/quasipositive
factorizations.


title:
Kernel-based Sensor Fusion with Application to Audio-Visual Voice
  Activity Detection

abstract:
  In this paper, we address the problem of multiple view data fusion in the
presence of noise and interferences. Recent studies have approached this
problem using kernel methods, by relying particularly on a product of kernels
constructed separately for each view. From a graph theory point of view, we
analyze this fusion approach in a discrete setting. More specifically, based on
a statistical model for the connectivity between data points, we propose an
algorithm for the selection of the kernel bandwidth, a parameter, which, as we
show, has important implications on the robustness of this fusion approach to
interferences. Then, we consider the fusion of audio-visual speech signals
measured by a single microphone and by a video camera pointed to the face of
the speaker. Specifically, we address the task of voice activity detection,
i.e., the detection of speech and non-speech segments, in the presence of
structured interferences such as keyboard taps and office noise. We propose an
algorithm for voice activity detection based on the audio-visual signal.
Simulation results show that the proposed algorithm outperforms competing
fusion and voice activity detection approaches. In addition, we demonstrate
that a proper selection of the kernel bandwidth indeed leads to improved
performance.


title: High Dimensional Random Walks and Colorful Expansion

abstract:
  Random walks on bounded degree expander graphs have numerous applications,
both in theoretical and practical computational problems. A key property of
these walks is that they converge rapidly to their stationary distribution.
  In this work we {\em define high order random walks}: These are
generalizations of random walks on graphs to high dimensional simplicial
complexes, which are the high dimensional analogues of graphs. A simplicial
complex of dimension $d$ has vertices, edges, triangles, pyramids, up to
$d$-dimensional cells. For any $0 \leq i < d$, a high order random walk on
dimension $i$ moves between neighboring $i$-faces (e.g., edges) of the complex,
where two $i$-faces are considered neighbors if they share a common
$(i+1)$-face (e.g., a triangle). The case of $i=0$ recovers the well studied
random walk on graphs.
  We provide a {\em local-to-global criterion} on a complex which implies {\em
rapid convergence of all high order random walks} on it. Specifically, we prove
that if the $1$-dimensional skeletons of all the links of a complex are
spectral expanders, then for {\em all} $0 \le i < d$ the high order random walk
on dimension $i$ converges rapidly to its stationary distribution.
  We derive our result through a new notion of high dimensional combinatorial
expansion of complexes which we term {\em colorful expansion}. This notion is a
natural generalization of combinatorial expansion of graphs and is strongly
related to the convergence rate of the high order random walks.
  We further show an explicit family of {\em bounded degree} complexes which
satisfy this criterion. Specifically, we show that Ramanujan complexes meet
this criterion, and thus form an explicit family of bounded degree high
dimensional simplicial complexes in which all of the high order random walks
converge rapidly to their stationary distribution.


title:
Uniqueness for the electrostatic inverse boundary value problem with
  piecewise constant anisotropic conductivities

abstract:
  We discuss the inverse problem of determining the, possibly anisotropic,
conductivity of a body $\Omega\subset\mathbb{R}^{n}$ when the so-called
Neumann-to-Dirichlet map is locally given on a non empty curved portion
$\Sigma$ of the boundary $\partial\Omega$. We prove that anisotropic
conductivities that are \textit{a-priori} known to be piecewise constant
matrices on a given partition of $\Omega$ with curved interfaces can be
uniquely determined in the interior from the knowledge of the local
Neumann-to-Dirichlet map.


title: Ds-bounds for cyclic codes: new bounds for abelian codes

abstract:
  In this paper we develop a technique to extend any bound for cyclic codes
constructed from its defining sets (ds-bounds) to abelian (or multivariate)
codes. We use this technique to improve the searching of new bounds for abelian
codes.


title: Rota-Baxter coalgebras and Rota-Baxter bialgebras

abstract:
  We give a construction of Rota-Baxter coalgebras from Hopf module coalgebras
and also derive the structures of the pre-Lie coalgebras via Rota-Baxter
coalgebras of different weight. Finally, the notion of Rota-Baxter bialgebra is
introduced and some examples are provided.


title:
Reconstructing $f(R)$ gravity from viscous cosmology constrained by
  observations

abstract:
  In this paper, we reconstruct the $f(R)$ theory using the viscous $\omega$CDM
scenario (V-$\omega$CDM) constrained by several differently astrophysical
observations, including Type Ia supernovae (SNe Ia), observational Hubble
parameter data (OHD), Wilkinson Microwave Anisotropy Probe 9-year data
(WMAP-9), Planck observations and the single data point from the newest event
GW150914 (GW). We find that the joint constraints from SNe Ia+OHD+Planck+GW
data-sets give out a tighter restriction for the parameters of the
V-$\omega$CDM scenario than other constraints. Subsequently, we find that there
exists a substantially high degeneracy among these reconstructed $f(R)$
theories in the past, and that they start exhibiting differently evolutional
behaviors around the present epoch as well as much different in the distant
future. Furthermore, we make a comparison between the reconstructed $f(R)$
theory with the V-$\omega$CDM scenario and that with the $\omega$CDM scenario
constrained by using the SNe Ia+OHD+Planck+GW data-sets in the $f(R)-R$ plane,
and find that the two scenarios share an extremely high degeneracy, which
implies that the effect of bulk viscosity plays a negligible role in the
V-$\omega$CDM model during the whole evolutionary processes of the universe. In
addition, one can also find that the reconstructed $f(R)$ theories using the
two models just deviate from the standard Einstein gravity a little.


title: Dust Evolution and the Formation of Planetesimals

abstract:
  The solid content of circumstellar disks is inherited from the interstellar
medium: dust particles of at most a micrometer in size. Protoplanetary disks
are the environment where these dust grains need to grow at least 13 orders of
magnitude in size. Our understanding of this growth process is far from
complete, with different physics seemingly posing obstacles to this growth at
various stages. Yet, the ubiquity of planets in our galaxy suggests that planet
formation is a robust mechanism. This chapter focuses on the earliest stages of
planet formation, the growth of small dust grains towards the gravitationally
bound "planetesimals", the building blocks of planets. We will introduce some
of the key physics involved in the growth processes and discuss how they are
expected to shape the global behavior of the solid content of disks. We will
consider possible pathways towards the formation of larger bodies and conclude
by reviewing some of the recent observational advances in the field.


title:
Dynamics of energy transport and entropy production in ac-driven quantum
  electron systems

abstract:
  We analyze the time-resolved energy transport and the entropy production in
ac-driven quantum coherent electron systems coupled to multiple reservoirs at
finite temperature. At slow driving we formulate the first and second laws of
thermodynamics valid at each instant of time. We identify heat fluxes flowing
though the different pieces of the device and emphasize the importance of the
energy stored in the contact and central regions for the second law of
thermodynamics to be instantaneously satisfied. In addition, we discuss
conservative and dissipative contributions to the heat flux and to the entropy
production as a function of time. We illustrate these ideas with a simple model
corresponding to a driven level coupled to two reservoirs with different
chemical potentials.


title: A construction of Hom-Yetter-Drinfeld category

abstract:
  In continuation of our recent work about smash product Hom-Hopf algebras in
\cite{MLY}, we introduce Hom-Yetter-Drinfeld category $_H^H{\mathbb{YD}}$ via
Radford biproduct Hom-Hopf algebra, and prove that the Hom-Yetter-Drinfeld
modules can provide solutions of the Hom-Yang-Baxter equation and
$_H^H{\mathbb{YD}}$ is a pre-braided tensor category, where $(H, \b, S)$ is a
Hom-Hopf algebra. Furthermore, we obtain that $(A^{\natural}_{\diamond} H,\a\o
\b)$ is a Radford biproduct Hom-Hopf algebra if and only if $(A,\a)$ is a Hopf
algebra in the category $_H^H{\mathbb{YD}}$. At last, some examples and
applications are given.


title:
Comment on "Chaotic orbits for spinning particles in Schwarzschild
  spacetime"

abstract:
  The astrophysical relevance of chaos for a test particle with spin moving in
Schwarzschild spacetime was the objective of \cite{Verhaaren10}. Even if the
results of the study seem to be qualitatively in agreement with similar works,
the study presented in \cite{Verhaaren10} suffers both from theoretical and
technical issues. These issues are discussed in this comment.


title:
Fabrication of surface nanoscale axial photonics (SNAP) structures with
  a femtosecond laser

abstract:
  Surface nanoscale axial photonics (SNAP) structures are fabricated with a
femtosecond laser for the first time. The inscriptions introduced by the laser
pressurize the fiber and cause its nanoscale effective radius variation. We
demonstrate the subangstrom precise fabrication of individual and coupled SNAP
microresonators having the effective radius variation of several nanometers.
Our results pave the way to a novel ultraprecise SNAP fabrication technology
based on the femtosecond laser inscription.


title: From vertex detectors to inner trackers with CMOS pixel sensors

abstract:
  The use of CMOS Pixel Sensors (CPS) for high resolution and low material
vertex detectors has been validated with the 2014 and 2015 physics runs of the
STAR-PXL detector at RHIC/BNL. This opens the door to the use of CPS for inner
tracking devices, with 10-100 times larger sensitive area, which require
therefore a sensor design privileging power saving, response uniformity and
robustness. The 350 nm CMOS technology used for the STAR-PXL sensors was
considered as too poorly suited to upcoming applications like the upgraded
ALICE Inner Tracking System (ITS), which requires sensors with one order of
magnitude improvement on readout speed and improved radiation tolerance. This
triggered the exploration of a deeper sub-micron CMOS technology, Tower-Jazz
180 nm, for the design of a CPS well adapted for the new ALICE-ITS running
conditions. This paper reports the R&D results for the conception of a CPS well
adapted for the ALICE-ITS.


title: Thermal tuners on a Silicon Nitride platform

abstract:
  In this paper, the design trade-offs for the implementation of small
footprint thermal tuners on silicon nitride are presented, and explored through
measurements and supporting simulations of a photonic chip based on
Mach-Zehnder Interferometers. Firstly, the electrical properties of the tuners
are assessed, showing a compromise between compactness and deterioration.
Secondly, the different variables involved in the thermal efficiency, switching
power and heater dimensions, are analysed. Finally, with focus on exploring the
limits of this compact tuners with regards to on chip component density, the
thermal-cross talk is also investigated. Tuners with footprint of 270x5 {\mu}m
2 and switching power of 350 mW are reported, with thermal-cross talk, in terms
of induced phase change in adjacent devices of less than one order of magnitude
at distances over 20 {\mu}m. Paths for the improvement of thermal efficiency,
power consumption and resilience of the devices are also outlined


title: pMSSM SUSY and the ATLAS Z+jets+MET Excess

abstract:
  A possible explanation of the excesses observed by ATLAS in the Z+jets+MET
channel within the p(henomenological)MSSM is discussed. We have found that the
cascade of first/second generation squarks to binos to Higgsino LSPs, with
judiciously chosen sparticle masses, can provide a viable scenario that is
consistent with all other experimental constraints.


title:
Unified Stochastic Geometry Model for MIMO Cellular Networks with
  Retransmissions

abstract:
  This paper presents a unified mathematical paradigm, based on stochastic
geometry, for downlink cellular networks with multiple-input-multiple-output
(MIMO) base stations (BSs). The developed paradigm accounts for signal
retransmission upon decoding errors, in which the temporal correlation among
the signal-to-interference plus-noise-ratio (SINR) of the original and
retransmitted signals is captured. In addition to modeling the effect of
retransmission on the network performance, the developed mathematical model
presents twofold analysis unification for MIMO cellular networks literature.
First, it integrates the tangible decoding error probability and the abstracted
(i.e., modulation scheme and receiver type agnostic) outage probability
analysis, which are largely disjoint in the literature. Second, it unifies the
analysis for different MIMO configurations. The unified MIMO analysis is
achieved by abstracting unnecessary information conveyed within the interfering
signals by Gaussian signaling approximation along with an equivalent SISO
representation for the per-data stream SINR in MIMO cellular networks. We show
that the proposed unification simplifies the analysis without sacrificing the
model accuracy. To this end, we discuss the diversity-multiplexing tradeoff
imposed by different MIMO schemes and shed light on the diversity loss due to
the temporal correlation among the SINRs of the original and retransmitted
signals. Finally, several design insights are highlighted.


title:
Semiflexible Polymers Under Good Solvent Conditions Interacting With
  Repulsive Walls

abstract:
  Solutions of semiflexible polymers confined by repulsive planar walls are
studied by density functional theory and Molecular Dynamics simulations, to
clarify the competition between the chain alignment favored by the wall and the
depletion caused by the monomer-wall repulsion. A coarse-grained bead-spring
model with bond bending potential is studied, varying both the contour length
and the persistence length of the polymers, as well as the monomer
concentration in the solution (good solvent conditions are assumed throughout,
and solvent molecules are not included explicitly). The profiles of monomer
density and pressure tensor components near the wall are studied, and the
surface tension of the solution is obtained. While the surface tension slightly
decreases with chain length for flexible polymers, it clearly increases with
chain length for stiff polymers. Thus, at fixed density and fixed chain length
the surface tension also increases with increasing persistence length. Chain
ends always are enriched near the wall, but this effect is much larger for
stiff polymers than for flexible ones. Also the profiles of the mean square
gyration radius components near the wall and the nematic order parameter are
studied to clarify the conditions where wall-induced nematic order occurs.


title:
Landauer's formula with finite-time relaxation: Kramers' crossover in
  electronic transport

abstract:
  Landauer's formula is the standard theoretical tool to examine ballistic
transport in nano- and meso-scale junctions, but it necessitates that any
variation of the junction with time must be slow compared to characteristic
times of the system, e.g., the relaxation time of local excitations. Transport
through structurally dynamic junctions is, however, increasingly of interest
for sensing, harnessing fluctuations, and real-time control. Here, we calculate
the steady-state current when relaxation of electrons in the reservoirs is
present and demonstrate that it gives rise to three regimes of behavior: weak
relaxation gives a contact-limited current; strong relaxation localizes
electrons, distorting their natural dynamics and reducing the current; and in
an intermediate regime the Landauer view of the system only is recovered. We
also demonstrate that a simple equation of motion emerges, which is suitable
for efficiently simulating time-dependent transport.


title:
Observations of the stratorotational instability in rotating concentric
  cylinders

abstract:
  We study the stability of density stratified flow between co-rotating
vertical cylinders with rotation rates $\Omega_o < \Omega_i$ and radius ratio
$r_i/r_o=0.877$, where subscripts $o$ and $i$ refer to the outer and inner
cylinders. Just as in stellar and planetary accretion disks, the flow has
rotation, anticyclonic shear, and a stabilizing density gradient parallel to
the rotation axis. The primary instability of the laminar state leads not to
axisymmetric Taylor vortex flow but to the non-axisymmetric {\it
stratorotational instability} (SRI), so named by Shalybkov and R\"udiger
(2005). The present work extends the range of Reynolds numbers and buoyancy
frequencies ($N=\sqrt{(-g/\rho)(\partial \rho/\partial z)}$) examined in the
previous experiments by Boubnov and Hopfinger (1997) and Le Bars and Le Gal
(2007). Our observations reveal that the axial wavelength of the SRI
instability increases nearly linearly with Froude number, $Fr= \Omega_i/N$. For
small outer cylinder Reynolds number, the SRI occurs for inner inner Reynolds
number larger than for the axisymmetric Taylor vortex flow (i.e., the SRI is
more stable). For somewhat larger outer Reynolds numbers the SRI occurs for
smaller inner Reynolds numbers than Taylor vortex flow and even below the
Rayleigh stability line for an inviscid fluid. Shalybkov and R\"udiger (2005)
proposed that the laminar state of a stably stratified rotating shear flow
should be stable for $\Omega_o/ \Omega_i > r_i/r_o$, but we find that this
stability criterion is violated for $N$ sufficiently large; however, the
destabilizing effect of the density stratification diminishes as the Reynolds
number increases. At large Reynolds number the primary instability leads not to
the SRI but to a previously unreported nonperiodic state that mixes the fluid.


title: Central limit theorem analogues for multicolour urn models

abstract:
  The asymptotic behaviour of a generalised P\'olya--Eggenberger urn is
well--known to depend on the spectrum of its replacement matrix: If its
dominant eigenvalue $r$ is simple and no other eigenvalue is `large' in the
sense that its real part is greater than $r/2$, the normalized urn composition
is asymptotically normally distributed. However, if there is more than one
large eigenvalue, the first few random draws have a non--negligible effect on
the evolution of the urn process and almost sure random tendencies of order
larger than $\sqrt{n}$ typically prevent a classical central limit theorem. In
the present work, a central limit theorem analogue for the fluctuations of urn
models with regard to random linear drift and random periodic growth of order
larger than $\sqrt{n}$ is proved, covering the $m$-ary search tree and B-trees.
The proof builds on an eigenspace decomposition of the process in order to
separate components of different growth orders. By an accurately tailored
adaption of martingale techniques to the components, their joint limiting
behaviour is established and translated back to the urn process. Conveniently,
the approach encompasses results on small urn models and therefore provides a
unifying perspective on central limit theorems for certain urn models,
irrespective of their spectrum.


title: Shortest Recurrence Periods of Forced Novae

abstract:
  We revisit hydrogen shell burning on white dwarfs (WDs) with higher mass
accretion rates than the stability limit, \dot M_stable, above which hydrogen
burning is stable. Novae occur with mass accretion rates below the limit. For
an accretion rate > \dot M_stable, a first hydrogen shell flash occurs followed
by steady nuclear burning, so the shell burning will not be quenched as long as
the WD continuously accretes matter. On the basis of this picture, some
persistent supersoft X-ray sources can be explained by binary models with high
accretion rates. In some recent studies, however, the claim has been made that
no steady hydrogen shell burning exists even for accretion rates > \dot M_{\rm
stable}. We demonstrate that, in such cases, repetitive flashes occurred
because mass accretion was artificially controlled. If we stop mass accretion
during the outburst, no new nuclear fuel is supplied, so the shell burning will
eventually stop. If we resume mass accretion after some time, the next outburst
eventually occurs. In this way, we can design the duration of outburst and
interpulse time with manipulated mass accretion. We call such a controlled nova
a "forced nova." These forced novae, if they exist, could have much shorter
recurrence periods than "natural novae." We have obtained the shortest
recurrence periods for forced novae for various WD masses. Based on the
results, we revisit WD masses of some recurrent novae including T Pyx.


title: Analysing the Competency of Mathematical Modelling in Physics

abstract:
  A primary goal of physics is to create mathematical models that allow both
predictions and explanations of physical phenomena. We weave maths extensively
into our physics instruction beginning in high school, and the level and
complexity of the maths we draw on grows as our students progress through a
physics curriculum. Despite much research on the learning of both physics and
math, the problem of how to successfully teach most of our students to use
maths in physics effectively remains unsolved. A fundamental issue is that in
physics, we don't just use maths, we think about the physical world with it. As
a result, we make meaning with math-ematical symbology in a different way than
mathematicians do. In this talk we analyze how developing the competency of
mathematical modeling is more than just "learning to do math" but requires
learning to blend physical meaning into mathematical representations and use
that physical meaning in solving problems. Examples are drawn from across the
curriculum.


title: Three-Weight Ternary Linear Codes from a Family of Monomials

abstract:
  Based on a generic construction, two classes of ternary three-weight linear
codes are obtained from a family of power functions, including some APN power
functions. The weight distributions of these linear codes are determined
through studying the properties of some exponential sum related to the proposed
power functions.


title: On some results on the stability of Markov operators

abstract:
  We formulate a criterion for the existence of an invariant measure for a
Feller semigroup defined on a metric space with the e-property for bounded
continuous functions and use it to prove the asymptotic stability of a
semigroup satisfying a lower bound condition. Our results complement those of
A. Lasota and J. A. Yorke in proper metric spaces and of T. Szarek in Polish
spaces.


title: The Bernstein homomorphism via Aguiar-Bergeron-Sottile universality

abstract:
  If H is a commutative connected graded Hopf algebra over a commutative ring
k, then a certain canonical k-algebra homomorphism H -> H (x) QSym is defined,
where QSym denotes the Hopf algebra of quasisymmetric functions over k. This
homomorphism generalizes the "internal comultiplication" on QSym, and extends
what Hazewinkel (in Section 18.24 of his "Witt vectors") calls the Bernstein
homomorphism.
  We construct this homomorphism with the help of the universal property of
QSym as a combinatorial Hopf algebra (a well-known result by Aguiar, Bergeron
and Sottile) and extension of scalars (the commutativity of H allows us to
consider, for example, H (x) QSym as an H-Hopf algebra, and this change of
viewpoint significantly extends the reach of the universal property).


title: Efficient Pure State Quantum Tomography from Five Orthonormal Bases

abstract:
  For any finite dimensional Hilbert space, we construct explicitly five
orthonormal bases such that the corresponding measurements allow for efficient
tomography of an arbitrary pure quantum state. This means that such
measurements can be used to distinguish an arbitrary pure state from any other
state, pure or mixed, and the pure state can be reconstructed from the outcome
distribution in a feasible way. The set of measurements we construct is
independent of the unknown state, and therefore our results provide a fixed
scheme for pure state tomography, as opposed to the adaptive (state dependent)
scheme proposed by Goyeneche et al. in [Phys. Rev. Lett. 115, 090401 (2015)].
We show that our scheme is robust with respect to noise in the sense that any
measurement scheme which approximates these measurements well enough is equally
suitable for pure state tomography. Finally, we present two convex programs
which can be used to reconstruct the unknown pure state from the measurement
outcome distributions.


title: Achieving Energy Efficiency in Cloud Brokering

abstract:
  The proliferation of cloud providers has brought substantial interoperability
complexity to the public cloud market, in which cloud brokering has been
playing an important role. However, energy-related issues for public clouds
have not been well addressed in the literature. In this paper, we claim that
the broker is also situated in a perfect position where necessary actions can
be taken to achieve energy efficiency for public cloud systems, particularly
through job assignment and scheduling. We formulate the problem by a mixed
integer program and prove its NP-hardness. Based on the complexity analysis, we
simplify the problem by introducing admission control on jobs. In the sequel,
optimal job assignment can be done straightforwardly and the problem is
transformed into improving job admission rate by scheduling on two coupled
phases: data transfer and job execution. The two scheduling phases are further
decoupled and we develop efficient scheduling algorithm for each of them.
Experimental results show that the proposed solution can achieve significant
reduction on energy consumption with admission rates improved as well, even in
large-scale public cloud systems.


title: Magnetar field evolution and crustal plasticity

abstract:
  The activity of magnetars is believed to be powered by colossal magnetic
energy reservoirs. We sketch an evolutionary picture in which internal field
evolution in magnetars generates a twisted corona, form which energy may be
released suddenly in a single giant flare, or more gradually through smaller
outbursts and persistent emission. Given the ages of magnetars and the energy
of their giant flares, we suggest that their evolution is driven by a novel
mechanism: magnetic flux transport/decay due to persistent plastic flow in the
crust, which would invalidate the common assumption that the crustal lattice is
static and evolves only under Hall drift and Ohmic decay. We estimate the field
strength required to induce plastic flow as a function of crustal depth, and
the viscosity of the plastic phase. The star's superconducting core may also
play a role in magnetar field evolution, depending on the star's spindown
history and how rotational vortices and magnetic fluxtubes interact.


title:
The phase transition and holographic in modified Horava -Lifshitz black
  hole

abstract:
  In this paper, we take cosmological constant as a thermodynamical pressure
and it's conjugate quantity as a thermodynamical volume. This expression help
us to investigate the phase transition and holographic heat engine. So, in
order to have Van der Waals fluid behaviour in Horava -Lifshitz (HL) black
hole, we modified the solution of such black hole with some cosmology ansatz.
Also from holographic heat engine, we obtain Carnot efficiency for the HL black
hole. The phase transition of the system lead us to investigate the stability
condition for the corresponding black hole. In that case, we show that the
stability exist only in special region of black hole.


title: Molecular gas and star formation in the Tidal Dwarf Galaxy VCC 2062

abstract:
  The physical mechanisms driving star formation (SF) in galaxies are still not
fully understood. Tidal dwarf galaxies (TDGs), made of gas ejected during
galaxy interactions, seem to be devoid of dark matter and have a near-solar
metallicity. The latter makes it possible to study molecular gas and its link
to SF using standard tracers (CO, dust) in a peculiar environment. We present a
detailed study of a nearby TDG in the Virgo Cluster, VCC 2062, using new
high-resolution CO(1--0) data from the Plateau de Bure, deep optical imaging
from the Next Generation Virgo Cluster Survey (NGVS), and complementary
multiwavelength data. Until now, there was some doubt whether VCC 2062 was a
true TDG, but the new deep optical images from the NGVS reveal a stellar bridge
between VCC 2062 and its parent galaxy, NGC 4694, which is clear proof of its
tidal origin. Several high-resolution tracers (\halpha, UV, 8~\mi, and 24~\mi)
of the star formation rate (SFR) are compared to the molecular gas distribution
as traced by the CO(1-0). Coupled with the SFR tracers, the NGVS data are used
with the CIGALE code to model the stellar populations throughout VCC 2062,
yielding a declining SFR in the recent past, consistent with the low \halpha/UV
ratio, and a high burst strength. HI emission covers VCC 2062, whereas the CO
is concentrated near the HI maxima. The CO peaks correspond to two very
distinct regions: one with moderate SF to the NE and one with only slightly
weaker CO emission but with nearly no SF. Even where SF is clearly present, the
SFR is below the value expected from the surface density of the molecular and
the total gas as compared to spiral galaxies and other TDGs. After discussing
different possible explanations, we conclude that the low surface brightness is
a crucial parameter to understand the low SFR.