title: A model with Darwinian dynamics on a rugged landscape

abstract:
  We discuss the population dynamics with selection and random diffusion,
keeping the total population constant, in a fitness landscape associated with
Constraint Satisfaction, a paradigm for difficult optimization problems. We
obtain a phase diagram in terms of the size of the population and the diffusion
rate, with a glass phase inside which the dynamics keeps searching for better
configurations, and outside which deleterious `mutations' spoil the
performance. The phase diagram is analogous to that of dense active matter in
terms of temperature and drive.


title:
Non-negative matrix factorization-based subband decomposition for
  acoustic source localization

abstract:
  A novel non-negative matrix factorization (NMF) based subband decomposition
in frequency spatial domain for acoustic source localization using a microphone
array is introduced. The proposed method decomposes source and noise subband
and emphasises source dominant frequency bins for more accurate source
representation. By employing NMF, delay basis vectors and their subband
information in frequency spatial domain for each frame is extracted. The
proposed algorithm is evaluated in both simulated noise and real noise with a
speech corpus database. Experimental results clearly indicate that the
algorithm performs more accurately than other conventional algorithms under
both reverberant and noisy acoustic environments.


title:
The statistics of low frequency radio interference at the Murchison
  Radio-astronomy Observatory

abstract:
  We characterize the low frequency radio-frequency interference (RFI)
environment at the Murchison Radio-astronomy Observatory (MRO), the location
selected for the low-frequency component of the Square Kilometre Array. Data
were collected from the BIGHORNS instrument, located at the MRO, which records
a contiguous bandwidth between 70 and 300 MHz, between November 2014 to March
2015 inclusive. The data were processed to identify RFI, and we describe a
series of statistics in both the time and frequency domain, including modeling
of the RFI occupancy and signal power as a series of distribution functions,
with the goal of aiding future scientists and operation staff in observation
planning.


title: Dynamical Conductivity of Dirac Materials

abstract:
  For graphene (a Dirac material) it has been theoretically predicted and
experimentally observed that DC resistivity is proportional to $ T^4$ when the
temperature is much less than Bloch- Gr\"{u}neisen ($\Theta_{BG}$) temperature
and T linear in opposite case ($T>>\Theta_{BG}$). Going beyond the DC case, we
investigate the dynamical conductivity in graphene using the powerful method of
memory function formalism. In the DC (zero frequency regime) limit, we obtained
the above mention behavior which was previously obtained using the
Bloch-Boltzmann kinetic equation. In the finite frequency regime, we obtained
several new results: (1) the generalized Drude scattering rate, in the zero
temperature limit, shows $\omega^4 $ behavior at low frequencies ($\omega <<
k_B \Theta_{BG}/ \hbar$) and saturates at higher frequencies. We also observed
the Holstein Mechanism, however, with different power laws from that in the
case of metals; (2) At higher frequencies, $\omega>>k_B \Theta_{BG}/ \hbar$,
and higher temperatures $T>>\Theta_{BG}$, we observed that the generalized
Drude scattering rate is linear in temperature. In addition, several other
results are also obtained. With the experimental advancement of this field,
these results should be experimentally tested.


title:
A fast semi-discrete Kansa method to solve the two-dimensional
  spatiotemporal fractional diffusion

abstract:
  Anomalous diffusion is a common phenomenon observed in underground solute
transport, soil water infiltration and sediment movement, etc. Time and space
fractional derivative advection-dispersion equation (FADE) has been widely
employed as the governing equation to characterize above mentioned anomalous
diffusion related processes. However, a main problem in application of time and
space FADE model to describe the real-world mass transport processes, is its
low computation efficiency for long-time range and large irregular domain
cases. This study offers a new algorithm in which the Kansa method is used for
vector space fractional derivative term discretization and then analytical
approach for resulted time fractional ordinary system. The influence of node
distribution mode and node numbers on accuracy and convergence rate are
analysed through the numerical examples in one and two dimensional cases. To
test the application potentials of present methods, we offer the numerical
results of two dimensional time and space FADE models in continuous and
discrete cases. It shows that the solute plumes in heterogeneous and
anisotropic media, can be well simulated by using present method compared with
the previous time-consumed particle Monte-Carlo methods.


title: Equationally extremal semilattices

abstract:
  In the current paper we study extremal semilattices with respect to their
equational properties. In the class $\mathbf{S}_n$ of all semilattices of order
$n$ we find semilattices which have maximal (minimal) number of consistent
equations. Moreover, we find a semilattice in $\mathbf{S}_n$ with maximal sum
of numbers of solutions of equations.


title: Dynamics of piecewise translation maps

abstract:
  In this paper, we introduce a generalized piecewise translation map on the
Euclidean space. We provide a special case when this map is always of finite
type. For a finite type map in this case, we form conjectures on the
semi-continuity of the attractor. Moreover, we also provide some conjectures
and pictures on piecewise translations on a two dimensional torus.


title:
Littlewood-Paley theorem, Nikolskii inequality, Besov spaces, Fourier
  and spectral multipliers on graded Lie groups

abstract:
  In this paper we investigate Besov spaces on graded Lie groups. We prove a
Nikolskii type inequality (or the Reverse H\"older inequality) on graded Lie
groups and as consequence we obtain embeddings of Besov spaces. We prove a
version of the Littlewood-Paley theorem on graded Lie groups. The results are
applied to obtain embedding properties of Besov spaces and multiplier theorems
for both spectral and Fourier multipliers in Besov spaces on graded Lie groups.
In particular, we give a number of sufficient conditions for the boundedness of
Fourier multipliers in Besov spaces.


title:
Optimal Distributed Stochastic Mirror Descent for Strongly Convex
  Optimization

abstract:
  In this paper we consider convergence rate problems for stochastic
strongly-convex optimization in the non-Euclidean sense with a constraint set
over a time-varying multi-agent network. We propose two efficient non-Euclidean
stochastic subgradient descent algorithms based on the Bregman divergence as
distance-measuring function rather than the Euclidean distances that were
employed by the standard distributed stochastic projected subgradient
algorithms. For distributed optimization of nonsmooth and strongly convex
functions whose only stochastic subgradients are available, the first algorithm
recovers the best previous known rate of O(ln(T)/T) (where T is the total
number of iterations). The second algorithm is an epoch variant of the first
algorithm that attains the optimal convergence rate of O(1/T), matching that of
the best previously known centralized stochastic subgradient algorithm.
Finally, we report some simulation results to illustrate the proposed
algorithms.


title:
Wire active microrheology to differentiate viscoelastic liquids from
  soft solids

abstract:
  Viscoelastic liquids are characterized by a finite static viscosity and a
zero yield stress, whereas soft solids have an infinite viscosity and a
non-zero yield stress. The rheological nature of viscoelastic materials has
long been a challenge, and it is still a matter of debate. Here, we provide for
the first time the constitutive equations of linear viscoelasticity for
magnetic wires in yield stress materials, together with experimental
measurements using Magnetic Rotational Spectroscopy (MRS). With MRS, the wires
are submitted to a rotational magnetic field as a function of frequency and the
wire motion is monitored by time-lapse microscopy. The soft solids studied are
gel-forming polysaccharide aqueous dispersions (gellan gum) at concentrations
above the gelification point. It is found that soft solids exhibit a clear and
distinctive signature compared to viscous and viscoelastic liquids. In
particular, the wire average rotation velocity equals zero over a broad
frequency range. We also show the MRS technique is quantitative. From the wire
oscillation amplitudes, the equilibrium elastic modulus is retrieved and agrees
with polymer dynamics theory.


title: Wave-front error breakdown in LGS MOAO validated on-sky by CANARY

abstract:
  CANARY is the multi-object adaptive optics (MOAO) on-sky pathfinder developed
in the perspective of Multi-Object Spectrograph on Extremely Large
Telescopes~(ELTs). In 2013, CANARY was operated on-sky at the William Herschel
telescope~(WHT), using three off-axis natural guide stars~(NGS) and four
off-axis Rayleigh laser guide stars~(LGS), in open-loop, with the on-axis
compensated turbulence observed with a H-band imaging camera and a Truth
wave-front sensor~(TS) for diagnostic purposes. Our purpose is to establish a
reliable and accurate wave-front error breakdown for LGS MOAO. This will enable
a comprehensive analysis of \cana on-sky results and provide tools for
validating simulations of MOAO systems for ELTs. To evaluate the MOAO
performance, we compared the CANARY on-sky results running in MOAO, in Single
Conjugated Adaptive Optics~(SCAO) and in Ground Layer Adaptive Optics~(GLAO)
modes, over a large set of data acquired in 2013. We provide a statistical
study of the seeing. We also evaluated the wave-front error breakdown from both
analytic computations, one based on a MOAO system modelling and the other on
the measurements from the CANARY TS. We have focussed especially on the
tomographic error and we detail its vertical error decomposition~(VED). We show
that CANARY obtained 30.1\%, 21.4\% and 17.1\% H-band Strehl ratios in SCAO,
MOAO and GLAO respectively, for median seeing conditions with 0.66" of total
seeing including 0.59" at the ground. Moreover, we get 99\% of correlation over
4,500 samples, for any AO modes, between two analytic computations of residual
phase variance. Based on these variances, we obtain a reasonable
Strehl-ratio~(SR) estimation when compared to the measured IR image SR. We
evaluate the gain in compensation for the altitude turbulence brought by MOAO
when compared to GLAO.


title: CMOS-Memristor Hybrid Integrated Pixel Sensors

abstract:
  Increase in image resolution require the ability of image sensors to pack an
increased number of circuit components in a given area. On the the other hand a
high speed processing of signals from the sensors require the ability of pixel
to carry out pixel parallel operations. In the paper, we propose a modified 3T
and 4T CMOS wide dynamic range pixels, which we refer as 2T-M and 3T-M
configurations, comprising of MOSFETS and memristors. The low leakage currents
and low area of memristors helps to achieve the objective of reducing the area,
while the possibility to create arrays of memristors and MOSFETs across
different layers within the chip, ensure the possibility to scale the circuit
architecture.


title: Connected components of the moduli of elliptic K3 surfaces

abstract:
  The combinatorial type of an elliptic K3 surface with a zero section is the
pair of the ADE -type of singular fibers and the torsion part of the
Mordell-Weil group. We determine the set of connected components of the moduli
of elliptic K3 surfaces with fixed combinatorial type. Our method relies on the
theory of Miranda and Morrison on the structure of a genus of even indefinite
lattices, and computer-aided calculations of p-adic quadratic forms.


title:
Reasoning in the Bernays-Schoenfinkel-Ramsey Fragment of Separation
  Logic

abstract:
  Separation Logic (SL) is a well-known assertion language used in Hoare-style
modular proof systems for programs with dynamically allocated data structures.
In this paper we investigate the fragment of first-order SL restricted to the
Bernays-Schoenfinkel-Ramsey quantifier prefix $\exists^*\forall^*$, where the
quantified variables range over the set of memory locations. When this set is
uninterpreted (has no associated theory) the fragment is PSPACE-complete, which
matches the complexity of the quantifier-free fragment. However, SL becomes
undecidable when the quantifier prefix belongs to $\exists^*\forall^*\exists^*$
instead, or when the memory locations are interpreted as integers with linear
arithmetic constraints, thus setting a sharp boundary for decidability within
SL. We have implemented a decision procedure for the decidable fragment of
$\exists^*\forall^*$SL as a specialized solver inside a DPLL($T$) architecture,
within the CVC4 SMT solver. The evaluation of our implementation was carried
out using two sets of verification conditions, produced by (i) unfolding
inductive predicates, and (ii) a weakest precondition-based verification
condition generator. Experimental data shows that automated quantifier
instantiation has little overhead, compared to manual model-based
instantiation.


title: Adiabatic Quantum Computation

abstract:
  The quantum adiabatic theorem ensures that a slowly changing system,
initially prepared in its ground state, will evolve to its final ground state
with arbitrary precision. As a first result this thesis extends the original
theorem to projection operators keeping the statement valid for Hamiltonians
with degenerate ground spaces.
  Yet the main focus of this work lies in studying the efficiency of quantum
circuit simulations by adabatic quantum computation. The standard Hamiltonian
construction by Kitaev is based on a path graph reflecting the $L$ computation
steps and influencing the scaling of the necessary evolution time by its
spectral gap of $\mathcal{O}\left(\frac{1}{L^2}\right)$. Aspiring to an
improved running time we generalize Kitaev's Hamiltonian to so-called standard
graph Hamiltonians based on graph families with a different spectral gap.
  In this generalized construction the first two time derivatives of the
Hamiltonian and the fraction of initial vertices appear as additional
parameters of running time. In a first step the time derivatives can be proven
to be constant. Expansion results from spectral graph theory however impose a
trade-off between the spectral gap and the fraction of initial vertices as well
as the fraction of final vertices which corresponds to the probability for
obtaining the correct computational output. Graphs with spectral gap
$\mathcal{O}\left(\frac{1}{L^k}\right)$, $k<2$, turn out to contradict very
likely, graphs with $k<1$ even for sure at least one of the efficiency
criterias for running time, output probability or Hamiltonian implementation.
  The above results may also be obstacles for a possible quantum PCP-theorem in
complexity theory claiming the local Hamiltonian problem with constant gap to
be QMA-complete since the very same Kitaev Hamiltonian is constructed in the
QMA-hardness proof for the Local Hamiltonian problem.


title: A model for periodic blazars

abstract:
  We describe a scenario to explain blazar periodicities with timescales of
$\sim$ few years. The scenario is based on a binary super-massive black hole
(SMBH) system in which one of the two SMBH carries a jet. We discuss the
various mechanisms that can cause the jet to precess and produce corkscrew
patterns through space with a scale of $\sim$ few pc. It turns out that the
dominant mechanism responsible for the precession is simply the imprint of the
jet-carrying SMBH orbital speed on the jet. Gravitational deflection and
Lense-Thirring precession (due to the gravitational field of the other SMBH)
are second order effects.
  We complement the scenario with a kinematical jet model which is inspired to
the spine-sheath structure observed in M87. One of the main advantages of such
a structure is that it allows the peak of the synchrotron emission to scale
with frequency according to $\nu F\propto \nu^{\xi}$ as the viewing angle is
changed, where $\xi$ is not necessarily 3 or 4 as in the case of jets with
uniform velocity, but can be $\xi \sim 1$.
  Finally, we apply the model to the source PG1553+113, which has been recently
claimed to show a $T_{\rm obs}=(2.18\pm 0.08)\text{ yr}$ periodicity. We are
able to reproduce the optical and gamma-ray light curves and multiple
synchrotron spectra simultaneously. We also give estimates of the source mass
and size.


title:
Criteria of irreducibility of the Koopman representations for the group
  ${\rm GL}_0(2\infty,{\mathbb R})$

abstract:
  Our aim is to find the irreducibility criteria for the Koopman
representation, when the group acts on some space with a measure (Conjecture
1.5). Some general necessary conditions of the irreducibility of this
representation are established. In the particular case of the group ${\rm
GL}_0(2\infty,{\mathbb R})$ $= \varinjlim_{n}{\rm GL}(2n-1,{\mathbb R})$, the
inductive limit of the general linear groups we prove that these conditions are
also the necessary ones. The corresponding measure is infinite tensor products
of one-dimensional arbitrary Gaussian non-centered measures. The corresponding
$G$-space $X_m$ is a subspace of the space ${\rm Mat}(2\infty,{\mathbb R})$ of
infinite in both directions real matrices. In fact, $X_m$ is a collection of
$m$ infinite in both directions rows. This result was announced in [20]. We
give the proof only for $m\leq 2$. The general case will be studied later.


title: A $2\ell k$ Kernel for $\ell$-Component Order Connectivity

abstract:
  In the $\ell$-Component Order Connectivity problem ($\ell \in \mathbb{N}$),
we are given a graph $G$ on $n$ vertices, $m$ edges and a non-negative integer
$k$ and asks whether there exists a set of vertices $S\subseteq V(G)$ such that
$|S|\leq k$ and the size of the largest connected component in $G-S$ is at most
$\ell$. In this paper, we give a kernel for $\ell$-Component Order Connectivity
with at most $2\ell k$ vertices that takes $n^{\mathcal{O}(\ell)}$ time for
every constant $\ell$. On the way to obtaining our kernel, we prove a
generalization of the $q$-Expansion Lemma to weighted graphs. This
generalization may be of independent interest.


title: A Near-Linear Pseudopolynomial Time Algorithm for Subset Sum

abstract:
  Given a set $Z$ of $n$ positive integers and a target value $t$, the Subset
Sum problem asks whether any subset of $Z$ sums to $t$. A textbook
pseudopolynomial time algorithm by Bellman from 1957 solves Subset Sum in time
$O(nt)$. This has been improved to $O(n \max Z)$ by Pisinger [J. Algorithms'99]
and recently to $\tilde O(\sqrt{n} t)$ by Koiliaris and Xu [SODA'17].
  Here we present a simple randomized algorithm running in time $\tilde
O(n+t)$. This improves upon a classic algorithm and is likely to be
near-optimal, since it matches conditional lower bounds from Set Cover and
k-Clique.
  We then use our new algorithm and additional tricks to improve the best known
polynomial space solution from time $\tilde O(n^3 t)$ and space $\tilde O(n^2)$
to time $\tilde O(nt)$ and space $\tilde O(n \log t)$, assuming the Extended
Riemann Hypothesis. Unconditionally, we obtain time $\tilde O(n
t^{1+\varepsilon})$ and space $\tilde O(n t^\varepsilon)$ for any constant
$\varepsilon > 0$.


title: SP-rings with zero-divisors

abstract:
  We characterize the commutative rings whose ideals (resp. regular ideals) are
products of radical ideals.


title: A New Perspective on Randomized Gossip Algorithms

abstract:
  In this short note we propose a new approach for the design and analysis of
randomized gossip algorithms which can be used to solve the average consensus
problem. We show how that Randomized Block Kaczmarz (RBK) method - a method for
solving linear systems - works as gossip algorithm when applied to a special
system encoding the underlying network. The famous pairwise gossip algorithm
arises as a special case. Subsequently, we reveal a hidden duality of
randomized gossip algorithms, with the dual iterative process maintaining a set
of numbers attached to the edges as opposed to nodes of the network. We prove
that RBK obtains a superlinear speedup in the size of the block, and
demonstrate this effect through experiments.


title: Spin excitations in an all-organic double quantum dot molecule

abstract:
  We realize a strongly coupled double quantum dot in a single all-organic
molecule by introducing a non-conjugated bridge in between two identical
conjugated moieties. Spin-1/2 Kondo and Kondo enhanced low-energy excitations
for respectively the odd and even electron occupation are observed in
off-resonant transport. The ground state in the even occupation can be the
singlet or the triplet state varying between samples. This observation suggests
that both anti-ferromagnetic and ferromagnetic interactions between spins are
of the same order of magnitude.


title:
Bloch Oscillations in Optical and Zeeman Lattices in the Presence of
  Spin-Orbit Coupling

abstract:
  We address Bloch oscillations of a spin-orbit coupled atom in periodic
potentials of two types: Optical and Zeeman lattices. We show that in optical
lattices the spin-orbit coupling allows controlling the direction of atomic
motion and may lead to complete suppression of the oscillations at specific
values of the coupling strength. In Zeeman lattices the energy bands are found
to cross each other at the boundaries of the Brillouin zone, resulting in
period-doubling of the oscillations. In all cases, the oscillations are
accompanied by rotation of the pseudo-spin, with a dynamics that is determined
by the strength of the spin-orbit coupling. The predicted effects are discussed
also in terms of a Wannier-Stark ladder, which in optical lattices consist of
two mutually-shifted equidistant sub-ladders.


title:
Study of Lambda polarization in relativistic nuclear collisions at
  sqrt{s}_NN = 7.7-200 GeV

abstract:
  We present a calculation of the global polarization of Lambda hyperons in
relativistic Au-Au collisions at RHIC Beam Energy Scan range sqrt{s}_NN = 7.7 -
200 GeV with a 3+1 dimensional cascade + viscous hydro + cascade model,
UrQMD+vHLLE. Within this model, the mean polarization of Lambda in the
out-of-plane direction is predicted to decrease rapidly with collision energy
from a top value of about 2% at the lowest energy examined. We explore the
connection between the polarization signal and thermal vorticity and estimate
the feed-down contribution to Lambda polarization due to the decay of higher
mass hyperons.


title:
Generalization of metric classification algorithms for sequences
  classification and labelling

abstract:
  The article deals with the issue of modification of metric classification
algorithms. In particular, it studies the algorithm k-Nearest Neighbours for
its application to sequential data. A method of generalization of metric
classification algorithms is proposed. As a part of it, there has been
developed an algorithm for solving the problem of classification and labelling
of sequential data. The advantages of the developed algorithm of classification
in comparison with the existing one are also discussed in the article. There is
a comparison of the effectiveness of the proposed algorithm with the algorithm
of CRF in the task of chunking in the open data set CoNLL2000.


title: Ideal Relaxation of the Hopf Fibration

abstract:
  Ideal MHD relaxation is the topology-conserving reconfiguration of a magnetic
field into a lower energy state where the net force is zero. This is achieved
by modeling the plasma as perfectly conducting viscous fluid. It is an
important tool for investigating plasma equilibria and is often used to study
the magnetic configurations in fusion devices and astrophysical plasmas. We
study the equilibrium reached by a localized magnetic field through the
topology conserving relaxation of a magnetic field based on the Hopf fibration
in which magnetic field lines are closed circles that are all linked with one
another. Magnetic fields with this topology have recently been shown to occur
in non-ideal numerical simulations. Our results show that any localized field
can only attain equilibrium if there is a finite external pressure, and that
for such a field a Taylor state is unattainable. We find an equilibrium plasma
configuration that is characterized by a lowered pressure in a toroidal region,
with field lines lying on surfaces of constant pressure. Therefore, the field
is in a Grad-Shafranov equilibrium. Localized helical magnetic fields are found
when plasma is ejected from astrophysical bodies and subsequently relaxes
against the background plasma, as well as on earth in plasmoids generated by
e.g.\ a Marshall gun. This work shows under which conditions an equilibrium can
be reached and identifies a toroidal depression as the characteristic feature
of such a configuration.


title:
Vibration-induced coherence enhancement of the performance of a
  biological quantum heat engine

abstract:
  Photosynthesis has been a long-standing research interest due to its
fundamental importance. Recently, studies on photosynthesis processes also have
inspired attention from a thermodynamical aspect when considering
photosynthetic apparatuses as biological quantum heat engines. Quantum
coherence is shown to play a crucial role in enhancing the performance of these
quantum heat engines. Based on the experimentally reported structure, we
propose a quantum heat engine model with a non-Markovian vibrational mode. We
show that one can obtain a performance enhancement easily for a wide range of
parameters in the presence of the vibrational mode. Our results provide
insights into the photosynthetic processes and a design principle mimicking
natural organisms.


title:
Acoustically tuneable optical transmission through a subwavelength hole
  with a bubble

abstract:
  Efficient manipulation of light with sound in subwavelength-sized volumes is
important for applications in photonics, phononics and biophysics, but remains
elusive. We theoretically demonstrate the control of light with MHz-range
ultrasound in a subwavelength, 300 nm wide water-filled hole with a 100 nm
radius air bubble. Ultrasound-driven pulsations of the bubble modulate the
effective refractive index of the hole aperture, which gives rise to spectral
tuning of light transmission through the hole. This control mechanism opens up
novel opportunities for tuneable acousto-optic and optomechanical
metamaterials, and all-optical ultrasound transduction.

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


title:
Control of birhythmicity through conjugate self-feedback: Theory and
  experiment

abstract:
  Birhythmicity arises in several physical, biological and chemical systems.
Although, many control schemes are proposed for various forms of
multistability, only a few exist for controlling birhythmicity. In this paper
we investigate the control of birhythmic oscillation by introducing a
self-feedback mechanism that incorporates the variable to be controlled and its
canonical conjugate. Using a detailed analytical treatment, bifurcation
analysis and experimental demonstrations we establish that the proposed
technique is capable of eliminating birhythmicity and generates monorhythmic
oscillation. Further, the detailed parameter space study reveals that, apart
from monorhythmicity, the system shows transition between birhythmicity and
other dynamical forms of bistability. This study may have practical
applications in controlling birhythmic behavior of several systems, in
particular in biochemical and mechanical processes.


title:
Assembly and speed control in ion exchange based modular phoretic
  micro-swimmers

abstract:
  We report an experimental study on ion-exchange based modular micro-swimmers
in low-salt water. Cationic ion-exchange particles and passive cargo particles
assemble into self-propelling complexes, showing self-propulsion at speeds of
several microns per second over extended distances and times. We quantify the
assembly and speed of the complexes for different combinations of ion exchange
particles and cargo particles, substrate types, salt types and concentrations,
and cell geometries. Irrespective of experimental boundary conditions, we
observe a regular development of the assembly shape with increasing number of
cargo. Moreover, the swimming speed increases stepwise upon increasing the
number of cargo and then saturates at a maximum speed, indicating an active
role of cargo in modular swimming. We propose a geometric model of
self-assembly to describe the experimental observations in a qualitative way.
Our study also provides some constraints for future theoretical modelling and
simulation.


title:
Concentration-compactness at the mountain pass level for nonlocal
  Schr\"{o}dinger equations

abstract:
  The aim of this paper is to study a concentration-compactness principle for
inhomogeneous fractional Sobolev space $H^s (\mathbb{R}^N)$ for $0<s\leq N/2.$
As an application we establish Palais-Smale compactness for the Lagrangian
associated to the fractional Schr\"{o}dinger equation $(-\Delta)^{s} u + a(x)u=
f(x,u)$ for $0<s<1.$ Moreover, we prove the existence of nontrivial nonnegative
solutions to this class of elliptic equations for a wide class of possible
singular potentials $a(x)$; not necessarily bounded away from zero. We consider
possible oscillatory nonlinearities and that may not satisfy the
Ambrosetti-Rabinowitz condition and for both cases; subcritical and critical
growth range which are superlinear at origin.


title: Incremental One-Class Models for Data Classification

abstract:
  In this paper we outline a PhD research plan. This research contributes to
the field of one-class incremental learning and classification in case of
non-stationary environments. The goal of this PhD is to define a new
classification framework able to deal with very small learning dataset at the
beginning of the process and with abilities to adjust itself according to the
variability of the incoming data which create large scale datasets. As a
preliminary work, incremental Covariance-guided One-Class Support Vector
Machine is proposed to deal with sequentially obtained data. It is inspired
from COSVM which put more emphasis on the low variance directions while keeping
the basic formulation of incremental One-Class Support Vector Machine
untouched. The incremental procedure is introduced by controlling the possible
changes of support vectors after the addition of new data points, thanks to the
Karush-Kuhn-Tucker conditions, that have to be maintained on all previously
acquired data. Comparative experimental results with contemporary incremental
and non-incremental one-class classifiers on numerous artificial and real data
sets show that our method results in significantly better classification
performance.


title:
Microscopic folding model analysis of the radiative $(n,\gamma)$
  reactions near the $Z=28$ shell-closure and the weak s-process

abstract:
  The radiative thermal neutron capture cross sections over the range of
thermal energies from 1 keV to 1 MeV are studied in statistical Hauser-Feshbach
formalism. The optical model potential is constructed by folding the density
dependent M3Y nucleon-nucleon interaction with radial matter densities of
target nuclei obtained from relativistic-mean-field (RMF) theory. The standard
nuclear reaction code TALYS1.8 is used for calculation of cross sections. The
nuclei studied in the present work reside near the $Z=28$ proton shell closure
and are of astrophysical interests taking part in p-, s-, and r-process of
nucleosynthesis. The Maxwellian-averaged cross-section (MACS) values for
energies important for astrophysical applications are presented.


title: Gapless spin-liquid ground state in the $S = 1/2$ kagome antiferromagnet

abstract:
  Frustrated quantum magnetism has moved to the forefront of physics research,
posing fundamental questions concerning quantum disordered states,
entanglement, topology and the nature of the quantum wavefunction. The defining
problem in the field is one of the simplest, the ground state of the
nearest-neighbour $S = 1/2$ antiferromagnetic Heisenberg model on the kagome
lattice, but has defied all theoretical and numerical methods employed to date.
We apply the formalism of tensor-network states (TNS), specifically the method
of projected entangled simplex states (PESS), whose combination of a correct
accounting for multipartite entanglement and infinite system size provides
qualitatively new insight. By studying the ground-state energy, the staggered
magnetization we find at all finite tensor bond dimensions and the effects of a
second-neighbour coupling, we demonstrate that the ground state is a gapless
spin liquid. We discuss the comparison with other numerical studies and the
physical interpretation of the gapless ground state.


title: Shadows and quantum invariants

abstract:
  This is a PhD thesis about low dimensional topology, in particular knot thory
in 3-manifolds also different from the 3-sphere, topological applications of
quantum invariants, and Turaev's shadows. There is an introduction and a survey
for these topics. The thesis uses skein theory and focues on the connected sum
of copies of S^1xS^2 and on the 3-tours as ambient manifolds. The skein space
of the 3-torus is computed. The Tait conjecture and Eisermann's theorem have
been extended to the connected sums of copies of S^1xS^2. The knots and links
in S^1xS^2 whose crossing number is at most 3 are tabulated.


title: A Radiative Neutrino Model with $SU(2)_L$ Triplet Fields

abstract:
  We propose a loop induced neutrino mass model, in which we introduce several
exotic fermions and bosons with $SU(2)_L$ multiplet, and discuss various
phenomenologies such as lepton flavor violations, muon anomalous magnetic
moment, nonstandard interacting neutrinoless double beta decay, relic density
of dark matter, and the possibility of the spin independent direct detection
searches, imposing the constraints of oblique parameters. And we show a
benchmark point to satisfy all the constraints and discuss our predictions.


title: Inferring Person-to-person Proximity Using WiFi Signals

abstract:
  Today's societies are enveloped in an ever-growing telecommunication
infrastructure. This infrastructure offers important opportunities for sensing
and recording a multitude of human behaviors. Human mobility patterns are a
prominent example of such a behavior which has been studied based on cell phone
towers, Bluetooth beacons, and WiFi networks as proxies for location. However,
while mobility is an important aspect of human behavior, understanding complex
social systems requires studying not only the movement of individuals, but also
their interactions. Sensing social interactions on a large scale is a technical
challenge and many commonly used approaches---including RFID badges or
Bluetooth scanning---offer only limited scalability. Here we show that it is
possible, in a scalable and robust way, to accurately infer person-to-person
physical proximity from the lists of WiFi access points measured by smartphones
carried by the two individuals. Based on a longitudinal dataset of
approximately 800 participants with ground-truth interactions collected over a
year, we show that our model performs better than the current state-of-the-art.
Our results demonstrate the value of WiFi signals in social sensing as well as
potential threats to privacy that they imply.


title:
Proton-proton correlations in distinguishing the two-proton emission
  mechanism of $^{23}$Al and $^{22}$Mg

abstract:
  The proton-proton momentum correlation functions ($C_{pp}(q)$) for
kinematically complete decay channels of $^{23}$Al $\rightarrow$ p + p +
$^{21}$Na and $^{22}$Mg $\rightarrow$ p + p + $^{20}$Ne have been measured at
the RIKEN RI Beam Factory. From the very different correlation strength of
$C_{pp}(q)$ for $^{23}$Al and $^{22}$Mg, the source size and emission time
information were extracted from the $C_{pp}(q)$ data by assuming a Gaussian
source profile in the correlation function calculation code (CRAB). The results
indicated that the mechanism of two-proton emission from $^{23}$Al was mainly
sequential emission, while that of $^{22}$Mg was mainly three-body simultaneous
emission. By combining our earlier results of the two-proton relative momentum
and the opening angle, it is pointed out that the mechanism of two-proton
emission could be distinguished clearly.


title:
Anomalous Cooling of Coronal Loops with Turbulent Suppression of Thermal
  Conduction

abstract:
  We investigate the impact of turbulent suppression of parallel heat
conduction on the cooling of post-flare coronal loops. Depending on the value
of the mean free path $\lambda_T$ associated with the turbulent scattering
process, we identify four main cooling scenarios. The overall temperature
evolution, from an initial temperature in excess of $10^7$~K, is modeled in
each case, highlighting the evolution of the dominant cooling mechanism
throughout the cooling process. Comparison with observed cooling times allows
the value of $\lambda_T$ to be constrained, and interestingly this range
corresponds to situations where collision-dominated conduction plays a very
limited role, or even no role at all, in the cooling of post-flare coronal
loops.


title:
Initial partonic eccentricity fluctuations in a multi-phase transport
  model

abstract:
  Initial partonic eccentricities in Au+Au collisions at center-of-mass energy
$\sqrt{s_{NN}}$ = 200 GeV are investigated using a multi-phase transport model
with string melting scenario. The initial eccentricities in different order of
harmonics are studied using participant and cumulant definitions. Eccentricity
in terms of second-, fourth- and sixth order cumulants as a function of number
of participant nucleons are compared systematically with the traditional
participant definition. The ratio of the cumulant eccentricities
$\varepsilon\left\{4\right\}/\varepsilon\left\{2\right\}$ and
$\varepsilon\left\{6\right\}/\varepsilon\left\{4\right\}$ are studied in
comparison with the ratio of the corresponding flow harmonics. The conversion
coefficients ($v_n/\varepsilon_n$) are explored up to fourth order harmonic
based on cumulant method. Furthermore, studies on transverse momentum ($p_T$)
and pseudo-rapidity ($\eta$) dependencies of eccentricities and their
fluctuations are presented. As in ideal hydrodynamics initial eccentricities
are expected to be closely related to the final flow harmonics in relativistic
heavy-ion collisions, studies of the fluctuating initial condition in the AMPT
model will shed light on the tomography properties of the initial source
geometry.


title: Geometric Model of Topological Insulators from the Maxwell Algebra

abstract:
  We propose a novel geometric model of three-dimensional topological
insulators in presence of an external electromagnetic field. The gapped
boundary of these systems supports relativistic quantum Hall states and is
described by a Chern-Simons theory with a gauge connection that takes values in
the Maxwell algebra. This represents a non-central extension of the Poincar\'e
algebra and takes into account both the Lorentz and magnetic-translation
symmetries of the surface states. In this way, we derive a relativistic version
of the Wen-Zee term, and we show that the non-minimal coupling between the
background geometry and the electromagnetic field in the model is in agreement
with the main properties of the relativistic quantum Hall states in the flat
space.


title:
Critical behaviour in the optimal generation of multipartite
  entanglement

abstract:
  Two systems whose correlations cannot be classically accounted for display
the simplest instance of quantum entanglement. Although this two-party
association has caused a revolution in the foundations and uses of quantum
mechanics, genuine entanglement among several parties unveils a whole new class
of phenomena and applications. In this work we suggest a way to prepare Dicke
states from a tunable source of bipartite entanglement to investigate
foundational issues. The scheme has the following distinctive features: (i) it
relies on controlled information loss and {\it unentangled} measurements; (ii)
irrespective of the source entanglement, whenever a Dicke state is produced, it
is ideal; (iii) the optimal entanglement of the bipartite source undergoes a
second-order-like transition depending on the parameters of the Dicke state to
be produced. These properties lead to asymptotic results on the entanglement
between any qubit belonging to a Dicke state and the remaining qubits.


title:
Thermal and transport properties in central heavy-ion reactions around a
  few hundred MeV/nucleon

abstract:
  Thermalization process of nuclear matter in central fireball region of
heavy-ion collisions is investigated by employing an extension model of
Boltzmann-Uehling-Uhlenbeck, namely the Van der Waals
Boltzmann-Uehling-Uhlenbeck (VdWBUU) model. Temperature ($T$) is extracted by
the quantum Fermion fluctuation approach and other thermodynamic quantities,
such as density ($\rho$), entropy density ($s$), shear viscosity ($\eta$),
isospin diffusivity ($D_{I}$) and heat conductivity ($\kappa$), are also
deduced. The liquid-like and gas-like phase signs are discussed through the
behavior of shear viscosity during heavy-ion collisions process with the VdWBUU
model.


title: Coherent spin dynamics in gadolinium-doped CaWO4 crystal

abstract:
  We report the first observation of Rabi oscillations in the spin-7/2 ensemble
of trivalent gadolinium ions hosted in CaWO$_4$ single crystal. A number of
transitions within the lowest electronic multiplet $^8S_{7/2}$ of Gd$^{3+}$ ion
are studied using a combination of continuous-wave and pulsed electron
paramagnetic resonance spectroscopy. The corresponding Rabi damping curves and
the spin coherence times are detected at varying strengths of the microwave
field. These data are well reproduced by a theoretical model which accounts for
the intrinsic inhomogeneity of the microwave field within the microwave
resonator and the magnetic dipole interactions in the diluted spin ensemble.
The results indicate that the studied 8-level ground manifold of Gd$^{3+}$ ion
can represent an effective three qubit quantum system.


title:
A $p$-Laplacian Neumann problem with a possibly supercritical
  nonlinearity

abstract:
  We look for nonconstant, positive, radially nondecreasing solutions of the
quasilinear equation $-\Delta_p u+u^{p-1}=f(u)$ with $p>2$, in the unit ball
$B$ of $\mathbb R^N$, subject to homogeneous Neumann boundary conditions. The
assumptions on the nonlinearity $f$ are very mild and allow it to be possibly
supercritical in the sense of Sobolev embeddings. The main tools used are the
truncation method and a mountain pass-type argument. In the pure power case,
i.e., $f(u)=u^{q-1}$, we detect the limit profile of the solutions of the
problems as $q\to\infty$.


title:
Thermodynamic bounds on equilibrium fluctuations of a global or local
  order parameter

abstract:
  We analyze thermodynamic bounds on equilibrium fluctuations of an order
parameter, which are analogous to relations, which have been derived recently
in the context of non-equilibrium fluctuations of currents. We discuss the case
of {\it global} fluctuations when the order parameter is measured in the full
system of interest, and {\it local} fluctuations, when the order parameter is
evaluated only in a sub-part of the system. Using isometric fluctuation
theorems, we derive thermodynamic bounds on the fluctuations of the order
parameter in both cases. These bounds could be used to infer the value of
symmetry breaking field or the relative size of the observed sub-system to the
full system from {\it local} fluctuations.


title: A Scalar Curvature Formula For the Noncommutative 3-Torus

abstract:
  We compute the scalar curvature of a curved noncommutative 3-torus. To
perturb the flat metric, the standard volume form on the noncommutative 3-torus
is conformally perturbed and the corresponding perturbed Laplacian is analyzed.
  Using Connes' pseudodifferential calculus for the noncommutative 3-torus, we
explicitly compute the first three terms of the small time heat kernel
expansion for the perturbed Laplacian. The third term of the expansion gives a
local formula for the scalar curvature. Finally, we show that in the classical
limit when the deformation parameters vanish, our formula coincides with the
formula for the commutative case.


title: Drawing graphs using a small number of obstacles

abstract:
  An obstacle representation of a graph $G$ is a set of points in the plane
representing the vertices of $G$, together with a set of polygonal obstacles
such that two vertices of $G$ are connected by an edge in $G$ if and only if
the line segment between the corresponding points avoids all the obstacles. The
obstacle number ${\rm obs}(G)$ of $G$ is the minimum number of obstacles in an
obstacle representation of $G$.
  We provide the first non-trivial general upper bound on the obstacle number
of graphs by showing that every $n$-vertex graph $G$ satisfies ${\rm obs}(G)
\leq n\lceil\log{n}\rceil-n+1$. This refutes a conjecture of Mukkamala, Pach,
and P\'alv\"olgyi. For $n$-vertex graphs with bounded chromatic number, we
improve this bound to $O(n)$. Both bounds apply even when the obstacles are
required to be convex.
  We also prove a lower bound $2^{\Omega(hn)}$ on the number of $n$-vertex
graphs with obstacle number at most $h$ for $h<n$ and a lower bound
$\Omega(n^{4/3}M^{2/3})$ for the complexity of a collection of $M \geq
\Omega(n\log^{3/2}{n})$ faces in an arrangement of line segments with $n$
endpoints. The latter bound is tight up to a multiplicative constant.


title:
Effective-one-body waveforms for binary neutron stars using surrogate
  models

abstract:
  Gravitational-wave observations of binary neutron star systems can provide
information about the masses, spins, and structure of neutron stars. However,
this requires accurate and computationally efficient waveform models that take
<1s to evaluate for use in Bayesian parameter estimation codes that perform
10^7 - 10^8 waveform evaluations. We present a surrogate model of a nonspinning
effective-one-body waveform model with l = 2, 3, and 4 tidal multipole moments
that reproduces waveforms of binary neutron star numerical simulations up to
merger. The surrogate is built from compact sets of effective-one-body waveform
amplitude and phase data that each form a reduced basis. We find that 12
amplitude and 7 phase basis elements are sufficient to reconstruct any binary
neutron star waveform with a starting frequency of 10Hz. The surrogate has
maximum errors of 3.8% in amplitude (0.04% excluding the last 100M before
merger) and 0.043 radians in phase. The version implemented in the LIGO
Algorithm Library takes ~0.07s to evaluate for a starting frequency of 30Hz and
~0.8s for a starting frequency of 10Hz, resulting in a speed-up factor of ~10^3
- 10^4 relative to the original Matlab code. This allows parameter estimation
codes to run in days to weeks rather than years, and we demonstrate this with a
Nested Sampling run that recovers the masses and tidal parameters of a
simulated binary neutron star system.


title: Star Streams and the Assembly History of the Galaxy

abstract:
  Thin halo star streams originate from the evaporation of globular clusters
and therefore provide information about the early epoch globular cluster
population. The observed tidal tails from halo globular clusters in the Milky
Way are much more shorter than expected from a star cluster orbiting for
10~Gyr. The discrepancy is likely the result of the assumption that the
clusters have been orbiting in a non-evolving galactic halo for a Hubble time.
As a first step towards more realistic stream histories, a toy model that
combines an idealized merger model with a simplified model of the internal
collisional relaxation of individual star clusters is developed. On the
average, the velocity dispersion increases with distance causing the density of
the stream to decline with distance. Consequently, the streams visible in
current data will normally be some fraction of the entire stream. Nevertheless,
the high surface density segment of the stellar streams created from the
evaporation of the more massive globular clusters should all be visible in low
obscuration parts of the sky if closer than about 30~kpc. The Pan-STARRS1 halo
volume is used to compare the numbers of halo streams and globular clusters.


title:
Hook formulas for skew shapes II. Combinatorial proofs and enumerative
  applications

abstract:
  The Naruse hook-length formula is a recent general formula for the number of
standard Young tableaux of skew shapes, given as a positive sum over excited
diagrams of products of hook-lengths. In 2015 we gave two different
$q$-analogues of Naruse's formula: for the skew Schur functions, and for
counting reverse plane partitions of skew shapes. In this paper we give an
elementary proof of Naruse's formula based on the case of border strips. For
special border strips, we obtain curious new formulas for the Euler and
$q$-Euler numbers in terms of certain Dyck path summations.


title:
Heat, temperature and Clausius inequality in a model for active brownian
  particles

abstract:
  Methods of stochastic thermodynamics and hydrodynamics are applied to the a
recently introduced model of active particles. The model consists of an
overdamped particle subject to Gaussian coloured noise. Inspired by stochastic
thermodynamics, we derive from the system's Fokker-Planck equation the average
exchanges of heat and work with the active bath and the associated entropy
production. We show that a Clausius inequality holds, with the local
(non-uniform) temperature of the active bath replacing the uniform temperature
usually encountered in equilibrium systems. Furthermore, by restricting the
dynamical space to the first velocity moments of the local distribution
function we derive a hydrodynamic description where local pressure, kinetic
temperature and internal heat fluxes appear and are consistent with the
previous thermodynamic analysis. The procedure also shows under which
conditions one obtains the unified coloured noise approximation (UCNA): such an
approximation neglects the fast relaxation to the active bath and therefore
yields detailed balance and zero entropy production. In the last part, by using
multiple time-scale analysis, we provide a constructive method (alternative to
UCNA) to determine the solution of the Kramers equation and go beyond the
detailed balance condition determining negative entropy production.


title:
Measurements of the Inclusive Neutrino and Antineutrino Charged Current
  Cross Sections in MINERvA Using the Low-$\nu$ Flux Method

abstract:
  The total cross sections are important ingredients for the current and future
neutrino oscillation experiments. We present measurements of the total
charged-current neutrino and antineutrino cross sections on scintillator (CH)
in the NuMI low-energy beamline using an {\em in situ} prediction of the shape
of the flux as a function of neutrino energy from 2--50 GeV. This flux
prediction takes advantage of the fact that neutrino and antineutrino
interactions with low nuclear recoil energy ($\nu$) have a nearly constant
cross section as a function of incident neutrino energy. This measurement is
the lowest energy application of the low-$\nu$ flux technique, the first time
it has been used in the NuMI antineutrino beam configuration, and demonstrates
that the technique is applicable to future neutrino beams operating at
multi-GeV energies. The cross section measurements presented are the most
precise measurements to date below 5 GeV.


title:
Comment on "Critical point scaling of Ising spin glasses in a magnetic
  field" by J. Yeo and M.A. Moore

abstract:
  In a section of a recent publication, [J. Yeo and M.A. Moore, Phys. Rev. B
91, 104432 (2015)], the authors discuss some of the arguments in the paper by
Parisi and Temesv\'ari [Nuclear Physics B 858, 293 (2012)]. In this comment, it
is shown how these arguments are misinterpreted, and the existence of the
Almeida-Thouless transition in the upper critical dimension 6 reasserted.


title: On thermal production of self-interacting dark matter

abstract:
  We consider thermal production mechanisms of self-interacting dark matter in
models with gauged $Z_3$ symmetry. A complex scalar dark matter is stabilized
by the $Z_3$, that is the remnant of a local dark $U(1)_d$. Light dark matter
with large self-interaction can be produced from thermal freeze-out in the
presence of SM-annihilation, SIMP and/or forbidden channels. We show that dark
photon and/or dark Higgs should be relatively light for unitarity and then
assist the thermal freeze-out. We identify the constraints on the parameter
space of dark matter self-interaction and mass in cases that one or some of the
channels are important in determining the relic density.


title:
On the frequency distribution of neutral particles from low-energy
  strong interactions

abstract:
  The rejection of the contamination, or background, from low-energy strong
interactions at hadron collider experiments is a topic that has received
significant attention in the field of particle physics. This article builds on
a particle-level view of collision events, in line with recently-proposed
subtraction methods. While conventional techniques in the field usually
concentrate on probability distributions, our study is, to our knowledge, the
first attempt at estimating the frequency distribution of background particles
across the kinematic space inside individual collision events. In fact, while
the probability distribution can generally be estimated given a model of
low-energy strong interactions, the corresponding frequency distribution inside
a single event typically deviates from the average and cannot be predicted a
priori. We present preliminary results in this direction, and establish a
connection between our technique and the particle weighting methods that have
been the subject of recent investigation at the Large Hadron Collider.


title: On generalized trigonometric functions and series of rational functions

abstract:
  Here we introduce a way to construct generalized trigonometric functions
associated with any complex polynomials, and the well known trigonometric
functions can be seen to associate with polynomial $x^2-1$. We will show that
those generalized trigonometric functions have algebraic identities which
generalizes the well known $\sin^2(x)+\cos^2(x)=1$. One application of the
generalized trigonometric functions is evaluating infinite series of rational
functions.


title: Unsupervised clustering under the Union of Polyhedral Cones (UOPC) model

abstract:
  In this paper, we consider clustering data that is assumed to come from one
of finitely many pointed convex polyhedral cones. This model is referred to as
the Union of Polyhedral Cones (UOPC) model. Similar to the Union of Subspaces
(UOS) model where each data from each subspace is generated from a (unknown)
basis, in the UOPC model each data from each cone is assumed to be generated
from a finite number of (unknown) \emph{extreme rays}.To cluster data under
this model, we consider several algorithms - (a) Sparse Subspace Clustering by
Non-negative constraints Lasso (NCL), (b) Least squares approximation (LSA),
and (c) K-nearest neighbor (KNN) algorithm to arrive at affinity between data
points. Spectral Clustering (SC) is then applied on the resulting affinity
matrix to cluster data into different polyhedral cones. We show that on an
average KNN outperforms both NCL and LSA and for this algorithm we provide the
deterministic conditions for correct clustering. For an affinity measure
between the cones it is shown that as long as the cones are not very coherent
and as long as the density of data within each cone exceeds a threshold, KNN
leads to accurate clustering. Finally, simulation results on real datasets
(MNIST and YaleFace datasets) depict that the proposed algorithm works well on
real data indicating the utility of the UOPC model and the proposed algorithm.


title:
Preserving the value of large scale data analytics over time through
  selective re-computation

abstract:
  A pervasive problem in Data Science is that the knowledge generated by
possibly expensive analytics processes is subject to decay over time, as the
data used to compute it drifts, the algorithms used in the processes are
improved, and the external knowledge embodied by reference datasets used in the
computation evolves. Deciding when such knowledge outcomes should be refreshed,
following a sequence of data change events, requires problem-specific functions
to quantify their value and its decay over time, as well as models for
estimating the cost of their re-computation. What makes this problem
challenging is the ambition to develop a decision support system for informing
data analytics re-computation decisions over time, that is both generic and
customisable. With the help of a case study from genomics, in this vision paper
we offer an initial formalisation of this problem, highlight research
challenges, and outline a possible approach based on the collection and
analysis of metadata from a history of past computations.


title: Black hole feeding and feedback: the physics inside the "subgrid"

abstract:
  Black holes (BHs) are believed to be a key ingredient of galaxy formation.
However, the galaxy-BH interplay is challenging to study due to the large
dynamical range and complex physics involved. As a consequence, hydrodynamical
cosmological simulations normally adopt sub-grid models to track the unresolved
physical processes, in particular BH accretion; usually the spatial scale where
the BH dominates the hydrodynamical processes (the Bondi radius) is unresolved,
and an approximate Bondi-Hoyle accretion rate is used to estimate the growth of
the BH. By comparing hydrodynamical simulations at different resolutions (300,
30, 3 pc) using a Bondi-Hoyle approximation to sub-parsec runs with
non-parameterized accretion, our aim is to probe how well an approximated Bondi
accretion is able to capture the BH accretion physics and the subsequent
feedback on the galaxy. We analyse an isolated galaxy simulation that includes
cooling, star formation, Type Ia and Type II supernovae, BH accretion and AGN
feedback (radiation pressure, Compton heating/cooling) where mass, momentum,
and energy are deposited in the interstellar medium through conical winds. We
find that on average the approximated Bondi formalism can lead to both over-
and under-estimations of the BH growth, depending on resolution and on how the
variables entering into the Bondi-Hoyle formalism are calculated.


title:
Three-dimensional contact of TITH cartilage layers, a closed-form
  solution

abstract:
  Inhomogeneity and anisotropy play a crucial role in attributing articular
cartilage its properties. The frictionless contact model constructed here
consists in two thin biphasic transversely isotropic transversely homogeneous
(TITH) cartilage layers firmly attached onto rigid substrates and shaped as
elliptic paraboloids of different radii. Using asymptotic techniques, a
solution to the deformation problem of such material has been recently obtained
extending previous ones referred to homogeneous materials. The layer itself is
thin in comparison with the size of the contact area and the observed time is
shorter than the hydrogel characteristic time. The emerging three-dimensional
contact problem is solved in closed-form and numerical benchmarks for constant
and oscillating loads are given. The results are shown in terms of contact
pressure and approach of the bones. The latter is derived to be directly
proportional to the contact area. Existing experimental data are reinterpreted
in view of the current model formulation. Comparisons are made with existing
solutions for homogeneous biphasic materials in order to underline the
functional importance of inhomogeneity in spreading the contact pressure
distribution across the contact area. Particular attention is paid to the
applicability of the retrieved formulas for interpreting measurements of in
vivo experiments. Future directions are also prospected.


title:
An extremality of the translation-invariant Gibbs measure for the
  HC-model on a Cayley tree

abstract:
  In this paper we study the extremality of translation-invariant Gibbs measure
for the HC-model on a Cayley tree. It is known that for this model the
translation-invariant measure is unique. We give a new proof of this statement
and found regions of the extremality of this measure on the Cayley tree of
order k.


title:
Stability, instability, and blowup for time fractional and other
  non-local in time semilinear subdiffusion equations

abstract:
  We consider non-local in time semilinear subdiffusion equations on a bounded
domain, where the kernel in the integro-differential operator belongs to a
large class, which covers many relevant cases from physics applications, in
particular the important case of fractional dynamics. The elliptic operator in
the equation is given in divergence form with bounded measurable coefficients.
We prove a well-posedness result in the setting of bounded weak solutions and
study the stability and instability of the zero function in the special case
where the nonlinearity vanishes at 0. We also establish a blowup result for
positive convex and superlinear nonlinearities.


title: Magnetic liquids under high electric fields as optical diodes

abstract:
  We show and give examples of how unidirectional propagation of light rays in
the limit of geometric optics could arise in some magnetic fluids due to the
magnetoelectric effect under weak DC magnetic fields and strong DC electric
fields around half of their dielectric breakdown. For such liquids as kerosene
and transformer oils, one-way propagation of light may occur for 30 nm diameter
magnetic nanoparticles (e.g. cobalt) and concentrations of 2% or larger.


title:
Sensing Emotions in Text Messages: An Application and Deployment Study
  of EmotionPush

abstract:
  Instant messaging and push notifications play important roles in modern
digital life. To enable robust sense-making and rich context awareness in
computer mediated communications, we introduce EmotionPush, a system that
automatically conveys the emotion of received text with a colored push
notification on mobile devices. EmotionPush is powered by state-of-the-art
emotion classifiers and is deployed for Facebook Messenger clients on Android.
The study showed that the system is able to help users prioritize interactions.


title: Localized attack on clustering networks

abstract:
  Clustering network is one of which complex network attracting plenty of
scholars to discuss and study the structures and cascading process. We
primarily analyzed the effect of clustering coefficient to other various of the
single clustering network under localized attack. These network models
including double clustering network and star-like NON with clustering and
random regular (RR) NON of ER networks with clustering are made up of at least
two networks among which exist interdependent relation among whose degree of
dependence is measured by coupling strength. We show both analytically and
numerically, how the coupling strength and clustering coefficient effect the
percolation threshold, size of giant component, critical coupling point where
the behavior of phase transition changes from second order to first order with
the increase of coupling strength between the networks. Last, we study the two
types of clustering network: one type is same with double clustering network in
which each subnetwork satisfies identical degree distribution and the other is
that their subnetwork satisfies different degree distribution. The former type
is treated both analytically and numerically while the latter is treated only
numerically. In each section, we compared two results obtained from localized
attack and random attack according to Shao et al:[22].


title: Uncertainty Estimates in the Heston Model via Fisher Information

abstract:
  We address the information content of European option prices about volatility
in terms of the Fisher information matrix. We assume that observed option
prices are centred on the theoretical price provided by Heston's model
disturbed by additive Gaussian noise. We fit the likelihood function on the
components of the VIX, i.e., near- and next-term put and call options on the
S&P 500 with more than 23 days and less than 37 days to expiration and
non-vanishing bid, and compute their Fisher information matrices from the
Greeks in the Heston model. We find that option prices allow reliable estimates
of volatility with negligible uncertainty as long as volatility is large
enough. Interestingly, if volatility drops below a critical value, inferences
from option prices become impossible because Vega, the derivative of a European
option w.r.t. volatility, nearly vanishes.


title:
Sound and Automated Synthesis of Digital Stabilizing Controllers for
  Continuous Plants

abstract:
  Modern control is implemented with digital microcontrollers, embedded within
a dynamical plant that represents physical components. We present a new
algorithm based on counter-example guided inductive synthesis that automates
the design of digital controllers that are correct by construction. The
synthesis result is sound with respect to the complete range of approximations,
including time discretization, quantization effects, and finite-precision
arithmetic and its rounding errors. We have implemented our new algorithm in a
tool called DSSynth, and are able to automatically generate stable controllers
for a set of intricate plant models taken from the literature within minutes.


title:
On the general form of linear functionals on the Hardy spaces $H^1$ over
  compact Abelian groups and some of its applications

abstract:
  The celebrated Fefferman's theorems on the general form of linear functionals
on the Hardy space $H^1$ over the circle group is generalized to the case of an
arbitrary compact Abelian group with totally ordered dual. Several corollaries
that can be applied to multiple lacunary Fourier series and atomic
decomposition on the two dimensional torus are obtained.


title:
A Symplectic Multi-Particle Tracking Model for Self-Consistent
  Space-Charge Simulation

abstract:
  Symplectic tracking is important in accelerator beam dynamics simulation. So
far, to the best of our knowledge, there is no self-consistent symplectic
space-charge tracking model available in the accelerator community. In this
paper, we present a two-dimensional and a three-dimensional symplectic
multi-particle spectral model for space-charge tracking simulation. This model
includes both the effect from external fields and the effect of self-consistent
space-charge fields using a split-operator method. Such a model preserves the
phase space structure and shows much less numerical emittance growth than the
particle-in-cell model in the illustrative examples.


title:
Global in Time Classical Solutions to the 3D Quasi-geostrophic System
  for Large Initial Data

abstract:
  In this paper, the authors show the existence of global in time classical
solutions to the 3D quasi-geostrophic system with Ekman pumping for any smooth
initial value (possibly large). This system couples an inviscid transport
equation in $\mathbb{R}^3_+$ with an equation on the boundary satisfied by the
trace. The proof combines the De Giorgi regularization effect on the boundary
$z=0$ -similar to the so called surface quasi-geostrophic equation- with
Beale-Kato-Majda techniques to propagate regularity for $z>0$. A potential
theory argument is used to strengthen the regularization effect on the trace up
to the Besov space $\mathring{B}_{\infty,\infty}^1$.


title: High energy effects in multi-jet production at LHC

abstract:
  We study differential cross sections for the production of three and four
jets in multi-Regge kinematics, the main interest lying on azimuthal angle
dependences. The theoretical setup is the jet production from a single BFKL
ladder with a convolution of two/three BFKL Green functions, where two
forward/backward jets are always tagged in the final state. Furthermore, we
require the tagging of one/two further jets in more central regions of the
detectors with a relative separation in rapidity. We found, as result, that the
dependence on transverse momenta and rapidities of the central jets can be
considered as a distinct signal of the onset of BFKL dynamics.


title: La-doped CH3NH3BaI3 : A Promising Transparent Conductor

abstract:
  Hybrid perovskites (CH3NH3PbI3) is one of the most promising novel materials
for solar harvesting. Toxicity of lead (Pb), however, has always remained a
concern. We investigated the electronic structure of complete replacement of Pb
by alkaline earths (Ca, Sr, Ba) and found it to be wide band gapped (Eg)
semiconductors (band gap ~ 3.7 to 4.0 eV), and hence not suitable as absorber
material. This opens up a new avenue to explore these materials as transparent
conductor (TC). We doped CH3NH3BaI3 (largest Eg) with La, which shifts its
Fermi level (EF) at conduction band bottom and induces states at EF for
conduction. This is precisely what is required for a transparent conductor.
Optical and transport properties simulated from linear response (within Density
Functional Theory (DFT)) calculations suggested it to be a very good TC
material with a high figure of merit ({\sigma}/{\alpha}), where {\sigma} is the
electrical conductivity and {\alpha} is the optical absorption coefficient.
This claim is also supported by our calculated results on density of states at
EF, effective mass, carrier concentration etc. at various La-doping. We propose
CH3NH3(Ba1-xLax)I3 (x~12.5%) to be a good TC material to be used in a all
perovskite solar cell.


title: Parking 3-sphere swimmer. I. Energy minimizing strokes

abstract:
  The paper is about the parking 3-sphere swimmer ($\text{sPr}_3$). This is a
low-Reynolds number model swimmer composed of three balls of equal radii. The
three balls can move along three horizontal axes (supported in the same plane)
that mutually meet at the center of $\text{sPr}_3$ with angles of $120^{\circ}$
. The governing dynamical system is introduced and the implications of its
geometric symmetries revealed. It is then shown that, in the first order range
of small strokes, optimal periodic strokes are ellipses embedded in 3d space,
i.e. closed curves of the form $t\in [0,2\pi] \mapsto (\cos t)u + (\sin t)v$
for suitable orthogonal vectors $u$ and $v$ of $\mathbb{R}^3$. A simple
analytic expression for the vectors $u$ and $v$ is derived. The results of the
paper are used in a second article where the real physical dynamics of
$\text{sPr}_3$ is analyzed in the asymptotic range of very long arms.


title: The logical complexity of finitely generated commutative rings

abstract:
  We characterize those finitely generated commutative rings which are
(parametrically) bi-interpretable with arithmetic: a finitely generated
commutative ring $A$ is bi-interpretable with $(\mathbb N,{+},{\times})$ if and
only if the space of non-maximal prime ideals of $A$ is nonempty and connected
in the Zariski topology and the nilradical of $A$ has a nontrivial annihilator
in $\mathbb Z$. Notably, by constructing a nontrivial derivation on a
nonstandard model of arithmetic we show that the ring of dual numbers over
$\mathbb Z$ is not bi-interpretable with $\mathbb N$.


title:
Optimal sampling rates for approximating analytic functions from
  pointwise samples

abstract:
  We consider the problem of approximating an analytic function on a compact
interval from its values at $M+1$ distinct points. When the points are
equispaced, a recent result (the so-called impossibility theorem) has shown
that the best possible convergence rate of a stable method is root-exponential
in $M$, and that any method with faster exponential convergence must also be
exponentially ill-conditioned at a certain rate. This result hinges on a
classical theorem of Coppersmith & Rivlin concerning the maximal behaviour of
polynomials bounded on an equispaced grid. In this paper, we first generalize
this theorem to arbitrary point distributions. We then present an extension of
the impossibility theorem valid for general nonequispaced points, and apply it
to the case of points that are equidistributed with respect to (modified)
Jacobi weight functions. This leads to a necessary sampling rate for stable
approximation from such points. We prove that this rate is also sufficient, and
therefore exactly quantify (up to constants) the precise sampling rate for
approximating analytic functions from such node distributions with stable
methods. Numerical results -- based on computing the maximal polynomial via a
variant of the classical Remez algorithm -- confirm our main theorems. Finally,
we discuss the implications of our results for polynomial least-squares
approximations. In particular, we theoretically confirm the well-known
heuristic that stable least-squares approximation using polynomials of degree
$N < M$ is possible only once $M$ is sufficiently large for there to be a
subset of $N$ of the nodes that mimic the behaviour of the $N$th set of
Chebyshev nodes.


title:
Semi-Supervised Source Localization on Multiple-Manifolds with
  Distributed Microphones

abstract:
  The problem of source localization with ad hoc microphone networks in noisy
and reverberant enclosures, given a training set of prerecorded measurements,
is addressed in this paper. The training set is assumed to consist of a limited
number of labelled measurements, attached with corresponding positions, and a
larger amount of unlabelled measurements from unknown locations. However,
microphone calibration is not required. We use a Bayesian inference approach
for estimating a function that maps measurement-based feature vectors to the
corresponding positions. The central issue is how to combine the information
provided by the different microphones in a unified statistical framework. To
address this challenge, we model this function using a Gaussian process with a
covariance function that encapsulates both the connections between pairs of
microphones and the relations among the samples in the training set. The
parameters of the process are estimated by optimizing a maximum likelihood (ML)
criterion. In addition, a recursive adaptation mechanism is derived where the
new streaming measurements are used to update the model. Performance is
demonstrated for 2-D localization of both simulated data and real-life
recordings in a variety of reverberation and noise levels.


title: $CP$ violation in $D$ meson decays at Belle

abstract:
  $CP$ violation and branching fraction measurements in $D$ decays are
interesting topics as any difference with respect to the Standard Model
prediction would be an indication of new physics. With the large data sample
collected by the Belle detector, which sits at the interaction point of KEKB
asymmetric $e^{+} e^{-}$ collider in Japan, we present the results of searches
for $CP$ violation in $D^{0}\rightarrow V\gamma~(V = \phi, \overline{K}^{*0},
\rho^{0})$ decay and the rare $D$ decay $D^{0}\rightarrow \gamma \gamma$.


title:
Near field asymptotics for the porous medium equation in exterior
  domains. The critical two-dimensional case

abstract:
  We consider the porous medium equation in an exterior two-dimensional domain
which excludes a hole, with zero Dirichlet data on its boundary. Gilding and
Goncerzewicz proved in [Gilding-Goncerzewicz-2007] that in the far field scale,
$x=\xi t^{\frac1{2m}}/(\log t)^{\frac{m-1}{2m}}$, $\xi\ne 0$, solutions to this
problem with an integrable and compactly supported initial data behave as an
instantaneous point-source solution for the equation with a variable mass that
decays to 0 in a precise way, determined by the initial data and the hole.
However, their result does not say much about the behavior when
$|x|=o\big(t^{\frac1{2m}}/(\log t)^{\frac{m-1}{2m}}\big)$, in the so called
near field scale, except that the solution is $o\big((t\log t)^{-\frac1m}\big)$
there. In particular, it does not give a sharp decay rate, neither a nontrivial
asymptotic profile, on compact sets. In this paper we characterize the large
time behavior in such scale, thus completing the results of
[Gilding-Goncerzewicz-2007].


title: Evolution without evolution, and without ambiguities

abstract:
  In quantum theory it is possible to explain time, and dynamics, in terms of
entanglement. This is the timeless approach to time, which assumes that the
universe is in a stationary state, where two non-interacting subsystems, the
clock and the rest, are entangled. As a consequence, by choosing a suitable
observable of the clock, the relative state of the rest of the universe evolves
unitarily with respect to the variable labelling the clock observable's
eigenstates, which is then interpreted as time. This model for an evolution
without evolution (Page and Wootters, 1983), albeit elegant, has never been
developed further, because it was criticised for generating severe ambiguities
in the dynamics of the rest of the universe. In this paper we show that there
are no such ambiguities, we also update the model, making it amenable to
possible new applications.


title:
Stakeholder Involvement: A Success Factor for Achieving Better UX
  Integration

abstract:
  Stakeholder involvement is one of the major success factors in integrating
user experience (UX) practices into software development processes and
organizations. It is also a necessity for agile software development. However,
practitioners still have limited access to guidelines on successful involvement
of UX stakeholders in agile settings. Moreover, agile UX literature does not
well address the specific characteristics of UX and it does not clearly
differentiate between UX and usability work. This paper presents two guidelines
for supporting stakeholder involvement in both UX integration and the daily UX
work. In particular, we focus on the special characteristics of UX: being
dynamic, subjective, holistic, and context-dependent. The guidelines clarify
practical implications of these characteristics for practitioners. In addition,
they can help researchers in addressing these characteristics better in agile
UX research.


title:
Signature of enhanced spin-orbit interaction in the magnetoresistance of
  LaTiO$_3$/SrTiO$_3$ interfaces on $\delta$-doping

abstract:
  We present a study of modulation of spin-orbit interaction (SOI) at the
interface of LaTiO$_3$/SrTiO$_3$ by $\delta$-doping with an iso-structural
ferromagnetic perovskite LaCoO$_3$. The sheet carrier density at the interface
decreases exponentially with $\delta$-doping thickness. We have explored that
the spin-orbit scattering time ($\tau_{so}$) can be decreased by nearly 3
orders of magnitude, whereas the inelastic scattering time ($\tau_{i}$) remains
almost constant with $\delta$-doping thickness. We have also observed that the
$\tau_{i}$ varies almost inversely proportional to temperature and $\tau_{so}$
remains insensitive to temperature, which suggest that the spin relaxation in
these interfaces follows D'yakonov-Perel mechanism. The observed in-plane
anisotropic magnetoresistance is attributed to the mixing of the spin up and
spin down states of d-band at Fermi level due to SOI.


title:
Fatou's Lemma, Galerkin Approximations and the Existence of Walrasian
  Equilibria in Infinite Dimensions

abstract:
  This essay has three objectives: (i) to report recent generalizations of
Fatou's lemma to multi-functions taking values in a Banach space, and framed in
terms of both Bochner and Gelfand integration; (ii) to delineate the importance
of Galerkin approximations in Walrasian general equilibrium theory with a
continuum of agents and commodities; and thereby (iii) to present two new
results on the existence of a Walrasian equilibrium in economies where the
continuum of agents is formalized as a saturated measure space.


title:
An Alternative Strategy to Control the Electronic Properties of Bilayer
  Graphene: Semi-metal to Metal Transition and a 2D Material with Dirac Cone

abstract:
  The AB-stacked bilayer graphene (BLG) is a pure semiconductor whose band gap
and properties can be tuned by various methods such as doping or applying gate
voltage. Here we show an alternative method to control the electronic
properties of BLG; intercalation of transition metal atoms between the two
monolayers graphene (MLG). A theoretical investigation has been performed on
two-dimensional MLG, BLG, BLG-intercalated nanostructured materials, all of
which are energetically stable. Our study reveals that only MLG and
BLG-intercalated with one Vanadium (V) atom (BLG-1V) materials have a Dirac
Cone at the K-point. This study reveals a new strategy to control the material
properties of BLG to exhibit various behaviors, including: metallic,
semi-metallic, and semiconducting by varying the concentration and spin
arrangement of the V atoms in BLG. In all the cases, the present DFT
calculations show that the 2p$_z$ sub-shells of C atoms in graphene and the
3d$_{yz}$ sub-shells of the V atoms provide the electron density near the Fermi
level controlling the material properties of the BLG-intercalated materials.
Thus we prove that out-of-plane atoms can influence in plane electronic
densities in BLG.


title: On rectangular HOMFLY for twist knots

abstract:
  As a new step in the study of rectangularly-colored knot polynomials, we
reformulate the prescription of arXiv:1606.06015 for twist knots in the
double-column representations $R=[rr]$ in terms of skew Schur polynomials.
These, however, are mysteriously shifted from the standard topological locus,
what makes further generalization to arbitrary $R=[r^s]$ not quite
straightforward.


title:
Remarks to the paper "Control system for reducing energy consumption in
  backbone computer network" from "Concurrency and Computation: Practice and
  Experience" journal

abstract:
  This paper indicates two errors in the formulation of the main optimization
model in the article "Control system for reducing energy consumption in
backbone computer network" by Niewiadomska-Szynkiewicz et al. and shows how to
fix them.


title: Flat Engineered Multi-Channel Reflectors

abstract:
  Recent advances in engineered gradient metasurfaces have enabled
unprecedented opportunities for light manipulation using optically thin sheets,
such as anomalous refraction, reflection, or focusing of an incident beam. Here
we introduce a concept of multi-channel functional metasurfaces, which are able
to control incoming and outgoing waves in a number of propagation directions
simultaneously. In particular, we reveal a possibility to engineer
multi-channel reflectors. Under the assumption of reciprocity and energy
conservation, we find that there exist three basic functionalities of such
reflectors: Specular, anomalous, and retro reflections. Multi-channel response
of a general flat reflector can be described by a combination of these
functionalities. To demonstrate the potential of the introduced concept, we
design and experimentally test three different multi-channel reflectors: Three-
and five-channel retro-reflectors and a three-channel power splitter.
Furthermore, by extending the concept to reflectors supporting higher-order
Floquet harmonics, we forecast the emergence of other multiple-channel flat
devices, such as isolating mirrors, complex splitters, and multi-functional
gratings.


title:
Past of a particle inside an interferometer: the two-state vector
  approach

abstract:
  Hashmi et al. [J. Phys. A 49, 345302 (2016)] claimed that the approach to the
past of a quantum particle introduced by Vaidman [Phys. Rev. A 87, 052104
(2013)] has difficulties in certain examples and that it even can be refuted.
Here I reply to their criticism showing that the approach provides a good
explanation of all examples they considered. It is fully consistent with
standard quantum mechanics and provides a useful tool for analyzing
interference experiments.


title: An Adaptive Test of Independence with Analytic Kernel Embeddings

abstract:
  A new computationally efficient dependence measure, and an adaptive
statistical test of independence, are proposed. The dependence measure is the
difference between analytic embeddings of the joint distribution and the
product of the marginals, evaluated at a finite set of locations (features).
These features are chosen so as to maximize a lower bound on the test power,
resulting in a test that is data-efficient, and that runs in linear time (with
respect to the sample size n). The optimized features can be interpreted as
evidence to reject the null hypothesis, indicating regions in the joint domain
where the joint distribution and the product of the marginals differ most.
Consistency of the independence test is established, for an appropriate choice
of features. In real-world benchmarks, independence tests using the optimized
features perform comparably to the state-of-the-art quadratic-time HSIC test,
and outperform competing O(n) and O(n log n) tests.


title: Similarity Learning for Time Series Classification

abstract:
  Multivariate time series naturally exist in many fields, like energy,
bioinformatics, signal processing, and finance. Most of these applications need
to be able to compare these structured data. In this context, dynamic time
warping (DTW) is probably the most common comparison measure. However, not much
research effort has been put into improving it by learning. In this paper, we
propose a novel method for learning similarities based on DTW, in order to
improve time series classification. Making use of the uniform stability
framework, we provide the first theoretical guarantees in the form of a
generalization bound for linear classification. The experimental study shows
that the proposed approach is efficient, while yielding sparse classifiers.


title: On the ideal case of a conjecture of Auslander and Reiten

abstract:
  A celebrated conjecture of Auslander and Reiten claims that a finitely
generated module $M$ that has no extensions with $M\oplus \Lambda$ over an
Artin algebra $\Lambda$ must be projective. This conjecture is widely open in
general, even for modules over commutative Noetherian local rings. Over such
rings, we prove that a large class of ideals satisfy the extension condition
proposed in the aforementioned conjecture of Auslander and Reiten. Along the
way we obtain a new characterization of regularity in terms of the injective
dimensions of certain ideals.


title: Tight Approximation Bounds for the Seminar Assignment Problem

abstract:
  The seminar assignment problem is a variant of the generalized assignment
problem in which items have unit size and the amount of space allowed in each
bin is restricted to an arbitrary set of values. The problem has been shown to
be NP-complete and to not admit a PTAS. However, the only constant factor
approximation algorithm known to date is randomized and it is not guaranteed to
always produce a feasible solution.
  In this paper we show that a natural greedy algorithm outputs a solution with
value within a factor of $(1 - e^{-1})$ of the optimal, and that unless
$NP\subseteq DTIME(n^{\log\log n})$, this is the best approximation guarantee
achievable by any polynomial time algorithm.


title:
V-type Near-Earth asteroids: dynamics, close encounters and impacts with
  terrestrial planets

abstract:
  Asteroids colliding with planets vary in composition and taxonomical type.
Among Near-Earth Asteroids (NEAs) are the V-types, basaltic asteroids that are
classified via spectroscopic observations. In this work, we study the
probability of
  V-type NEAs colliding with Earth, Mars and Venus, as well as the Moon. We
perform a correlational analysis of possible craters produced by V-type NEAs.
To achieve this, we performed numerical simulations and statistical analysis of
close encounters and impacts between V-type NEAs and the terrestrial planets
over the next 10 Myr. We find that V-type NEAs can indeed have impacts with all
the planets, the Earth in particular, at an average rate of once per 12 Myr.
  There are four candidate craters on Earth that were likely caused by V-type
NEAs.


title:
Recovering the Missing Link: Predicting Class-Attribute Associations for
  Unsupervised Zero-Shot Learning

abstract:
  Collecting training images for all visual categories is not only expensive
but also impractical. Zero-shot learning (ZSL), especially using attributes,
offers a pragmatic solution to this problem. However, at test time most
attribute-based methods require a full description of attribute associations
for each unseen class. Providing these associations is time consuming and often
requires domain specific knowledge. In this work, we aim to carry out
attribute-based zero-shot classification in an unsupervised manner. We propose
an approach to learn relations that couples class embeddings with their
corresponding attributes. Given only the name of an unseen class, the learned
relationship model is used to automatically predict the class-attribute
associations. Furthermore, our model facilitates transferring attributes across
data sets without additional effort. Integrating knowledge from multiple
sources results in a significant additional improvement in performance. We
evaluate on two public data sets: Animals with Attributes and aPascal/aYahoo.
Our approach outperforms state-of-the-art methods in both predicting
class-attribute associations and unsupervised ZSL by a large margin.


title:
A conducting nano-filament (CNF) network as a precursor to the origin of
  superconductivity in electron-doped copper oxides

abstract:
  Emergency of superconductivity at the instabilities of antiferromagnetism has
been widely recognized in unconventional superconductors. In copper-oxide
superconductors, spin fluctuations play a predominant role in electron pairing
with electron dopants yet composite orders veil the nature of superconductivity
for hole-doped family. However, in electron-doped copper oxide superconductors
(cuprates) the AFM critical end point is still in controversy for different
probes, demonstrating high sensitivity to oxygen content. Here, by carefully
tuning the oxygen content, a systematic study of the Hall signal and
magnetoresistivity up to 58 Tesla on LCCO thin films identifies two
characteristic temperatures. The former is quite robust, whereas the latter
becomes flexible with increasing magnetic field, thereby linking respectively
to two- and three-dimensional AFM, evident from the multidimensional phase
diagram as a function of oxygen and Ce dopants. A rigorous theoretical analysis
of the presented data suggest the existence of conductive nano-filamentary
structures that effectively corroborate all previously reported field studies.
The new findings provide a uniquely consistent alternative picture in
understanding the interactions between AFM and superconductivity in
electron-doped cuprates and offer a consolidating interpretation to the
pioneering scaling law in cuprates recently established by Bozovic et al.
(Nature, 2016)


title:
Bsmooth: Learning from user feedback to disambiguate query terms in
  interactive data retrieval

abstract:
  There is great interest in supporting imprecise queries (e.g., keyword search
or natural language queries) over databases today. To support such queries, the
database system is typically required to disambiguate parts of the
user-specified query against the database, using whatever resources are
intrinsically available to it (the database schema, data values distributions,
natural language models etc). Often, systems will also have a user-interaction
log available, which can serve as an extrinsic resource to supplement their
model based on their own intrinsic resources. This leads to a problem of how
best to combine the system's prior ranking with insight derived from the
user-interaction log. Statistical inference techniques such as maximum
likelihood or Bayesian updates from a subjective prior turn out not to apply in
a straightforward way due to possible noise from user search behavior and to
encoding biases endemic to the system's models. In this paper, we address such
learning problem in interactive data retrieval, with specific focus on type
classification for user-specified query terms. We develop a novel Bayesian
smoothing algorithm, Bsmooth, which is simple, fast, flexible and accurate. We
analytically establish some desirable properties and show, through experiments
against an independent benchmark, that the addition of such a learning layer
performs much better than standard methods.


title: Prioritized Garbage Collection: Explicit GC Support for Software Caches

abstract:
  Programmers routinely trade space for time to increase performance, often in
the form of caching or memoization. In managed languages like Java or
JavaScript, however, this space-time tradeoff is complex. Using more space
translates into higher garbage collection costs, especially at the limit of
available memory. Existing runtime systems provide limited support for
space-sensitive algorithms, forcing programmers into difficult and often
brittle choices about provisioning.
  This paper presents prioritized garbage collection, a cooperative programming
language and runtime solution to this problem. Prioritized GC provides an
interface similar to soft references, called priority references, which
identify objects that the collector can reclaim eagerly if necessary. The key
difference is an API for defining the policy that governs when priority
references are cleared and in what order. Application code specifies a priority
value for each reference and a target memory bound. The collector reclaims
references, lowest priority first, until the total memory footprint of the
cache fits within the bound. We use this API to implement a space-aware
least-recently-used (LRU) cache, called a Sache, that is a drop-in replacement
for existing caches, such as Google's Guava library. The garbage collector
automatically grows and shrinks the Sache in response to available memory and
workload with minimal provisioning information from the programmer. Using a
Sache, it is almost impossible for an application to experience a memory leak,
memory pressure, or an out-of-memory crash caused by software caching.


title: Cocenters of $p$-adic groups, I: Newton decomposition

abstract:
  In this paper, we introduce the Newton decomposition on a connected reductive
$p$-adic group $G$. Based on it we give a nice decomposition of the cocenter of
its Hecke algebra. Here we consider both the ordinary cocenter associated to
the usual conjugation action on $G$ and the twisted cocenter arising from the
theory of twisted endoscopy.
  We give Iwahori-Matsumoto type generators on the Newton components of the
cocenter. Based on it, we prove a generalization of Howe's conjecture on the
restriction of (both ordinary and twisted) invariant distributions. Finally we
give an explicit description of the structure of the rigid cocenter.


title:
First multicolour polarimetry of TeV gamma-ray binary HESS J0632+057
  close to periastron passage

abstract:
  We present the results of UBVRI polarimetry of the TeV gamma-ray binary HESS
J0632+057 obtained on 2015 March 24 (JD 2457106) and 2015 December 12 (JD
2457369). The detected polarisation values of HESS J0632+057, just after
periastron passage (March 24), are higher than all previously published values
(p(V) ~ 4.2%) and the position angle (theta ~ 171-172 degrees) is also
different by ~6-10 degrees from previously published values. The data obtained
just before the subsequent periastron passage (December 12) show statistically
lower polarisation in all photometric bands (p(V) ~ 3.9%) and a different
position angle theta ~ 167-168 degrees. From observations of a nearby field
star, the interstellar component of the measured polarisation was estimated as
p_is(V) ~ 0.65% and theta_is ~ 153 degrees. This estimate was used with the
previous "V"-band estimation by "field-stars method" (p(V) ~ 2% and theta_is ~
165 degrees) of Yudin (2014) to identify the wavelength dependence of the
intrinsic polarisation in HESS J0632+057. It was found that after subtraction
of the interstellar component (for both p_is estimates), the wavelength
dependence of the intrinsic polarisation in HESS J0632+057 is essentially flat.
We propose that the formation of an additional source of polarisation or some
perturbation of circumstellar material at this orbital phase can explain the
changes in the level of polarisation in HESS J0632+057 close to periastron
passage.


title: Low Power Wide Area Network Analysis: Can LoRa Scale?

abstract:
  Low Power Wide Area (LPWA) networks are making spectacular progress from
design, standardisation, to commercialisation. At this time of fast-paced
adoption, it is of utmost importance to analyse how well these technologies
will scale as the number of devices connected to the Internet of Things (IoT)
inevitably grows. In this letter, we provide a stochastic geometry framework
for modelling the performance of a single gateway LoRa network, a leading LPWA
technology. Our analysis formulates unique peculiarities of LoRa, including its
chirp spread-spectrum modulation technique, regulatory limitations on radio
duty cycle, and use of ALOHA protocol on top, all of which are not as common in
today's commercial cellular networks. We show that the coverage probability
drops exponentially as the number of end-devices grows due to interfering
signals using the same spreading sequence. We conclude that this fundamental
limiting factor is perhaps more significant towards LoRa scalability than for
instance spectrum restrictions. Our derivations for co-spreading factor
interference found in LoRa networks enables rigorous scalability analysis of
such networks.