title:
Extremely local electric field enhancement and light confinement in
  dielectric waveguide

abstract:
  The extremely local electric field enhancement and light confinement is
demonstrated in dielectric waveguide with corner and gap geometry. The
numerical results reveal the local electric field enhancement in the vicinity
of the apex of fan-shaped waveguide. Classical electromagnetic theory predicts
that the field enhancement and confinement abilities increase with decreasing
radius of rounded corner ($r$) and gap ($g$), and show singularity for
infinitesimal $r$ and $g$. For practical parameters with $r=g=10\,\mathrm{nm}$,
the mode area of opposing apex-to-apex fan-shaped waveguides can be as small as
$4\times10^{-3}A_{0}$ ($A_{0}=\lambda^{2}/4$), far beyond the diffraction
limit. This way of breaking diffraction limit with no loss outperforms
plasmonic waveguides, where light confinement is realized at the cost of huge
intrinsic loss in the metal. Furthermore, we propose a structure with
dielectric bow-tie antenna on a silicon-on-insulator waveguide, whose field
enhancement increases by one order. The lossless dielectric corner and gap
structures offer an alternative method to enhance the light-matter interaction
without metal nano-structure, and will find applications in quantum
electrodynamics, sensors and nano-particle trapping.


title: Optical conductivity of curved graphene

abstract:
  We compute the optical conductivity for an out-of-plane deformation in
graphene using an approach based on solutions of the Dirac equation in curved
space. Different examples of periodic deformations along one direction
translates into an enhancement of the optical conductivity peaks in the region
of the far and mid infrared frequencies for periodicities $\sim100\,$nm. The
width and position of the peaks can be changed by dialling the parameters of
the deformation profiles. The enhancement of the optical conductivity is due to
intraband transitions and the translational invariance breaking in the
geometrically deformed background. Furthemore, we derive an analytical solution
of the Dirac equation in a curved space for a general deformation along one
spatial direction. For this class of geometries, it is shown that curvature
induces an extra phase in the electron wave function, which can also be
explored to produce interference devices of the Aharonov-Bohm type.


title: An Event Structure Model for Probabilistic Concurrent Kleene Algebra

abstract:
  We give a new true-concurrent model for probabilistic concurrent Kleene
algebra. The model is based on probabilistic event structures, which combines
ideas from Katoen's work on probabilistic concurrency and Varacca's
probabilistic prime event structures. The event structures are compared with a
true-concurrent version of Segala's probabilistic simulation. Finally, the
algebraic properties of the model are summarised to the extent that they can be
used to derive techniques such as probabilistic rely/guarantee inference rules.


title:
On the viscosity solutions to a degenerate parabolic differential
  equation

abstract:
  In this work, we study some properties of the viscosity solutions to a
degenerate parabolic equation involving the non-homogeneous infinity-Laplacian.


title: The Firefighter Problem: A Structural Analysis

abstract:
  We consider the complexity of the firefighter problem where b>=1 firefighters
are available at each time step. This problem is proved NP-complete even on
trees of degree at most three and budget one (Finbow et al.,2007) and on trees
of bounded degree b+3 for any fixed budget b>=2 (Bazgan et al.,2012). In this
paper, we provide further insight into the complexity landscape of the problem
by showing that the pathwidth and the maximum degree of the input graph govern
its complexity. More precisely, we first prove that the problem is NP-complete
even on trees of pathwidth at most three for any fixed budget b>=1. We then
show that the problem turns out to be fixed parameter-tractable with respect to
the combined parameter "pathwidth" and "maximum degree" of the input graph.


title:
Socially-Optimal Design of Service Exchange Platforms with Imperfect
  Monitoring

abstract:
  In service exchange platforms, anonymous users exchange services with each
other: clients request services and are matched to servers who provide
services. Because providing good-quality services requires effort, in any
single interaction a server will have no incentive to exert effort and will
shirk. We show that if current servers will later become clients and want
good-quality services, shirking can be eliminated by rating protocols, which
maintain ratings for each user, prescribe behavior in each client-server
interaction, and update ratings based on whether observed/reported behavior
conforms with prescribed behavior. The rating protocols proposed are the first
to achieve social optimum even when observation/reporting is imperfect (quality
is incorrectly assessed/reported or reports are lost). The proposed protocols
are remarkably simple, requiring only binary ratings and three possible
prescribed behaviors. Key to the efficacy of the proposed protocols is that
they are nonstationary, and tailor prescriptions to both current and past
rating distributions.


title:
Interface Effects on Tunneling Magnetoresistance in Organic Spintronics
  with Flexible Amine-Au Links

abstract:
  Organic spintronics is a promising emerging field, but the sign of the
tunneling magnetoresistance (TMR) is highly sensitive to interface effects, a
crucial hindrance to applications. A key breakthrough in molecular electronics
was the discovery of amine-Au link groups that give reproducible conductance.
Using first principles calculations, we predict that amine-Au links give
improved reproducibility in organic spintronics junctions with Au-covered Fe
leads. The Au layers allow only states with sp character to tunnel into the
molecule, and the flexibility of amine-Au links results in a narrow range of
TMR for fixed number of Au layers. Even as the Au thickness changes, TMR
remains positive as long as the number of Au layers is the same on both sides
of the junction. Since the number of Au layers on Fe surfaces or Fe
nanoparticles can now be experimentally controlled, amine-Au links provide a
route towards robust TMR in organic spintronics.


title:
Fabrication and Characterization of Aluminum Airbridges for
  Superconducting Microwave Circuits

abstract:
  Superconducting microwave circuits based on coplanar waveguides (CPW) are
susceptible to parasitic slotline modes which can lead to loss and decoherence.
We motivate the use of superconducting airbridges as a reliable method for
preventing the propagation of these modes. We describe the fabrication of these
airbridges on superconducting resonators, which we use to measure the loss due
to placing airbridges over CPW lines. We find that the additional loss at
single photon levels is small, and decreases at higher drive powers.


title:
Photometric study of single-shot energy-dispersive X-ray diffraction at
  a laser plasma facility

abstract:
  The low repetition rates and possible shot-to-shot variations in laser-plasma
studies place a high value on single-shot diagnostics. For example, white-beam
scattering methods based on broadband backlighter x-ray sources are used to
determine changes in the structure of laser-shocked crystalline materials by
the evolution of coincidences of reciprocal lattice vectors and
kinematically-allowed momentum transfers. Here, we demonstrate that white-beam
techniques can be extended to strongly-disordered dense plasma and warm dense
matter (WDM) systems where reciprocal space is only weakly structured and
spectroscopic detection is consequently needed to determine the static
structure factor and thus the ion-ion radial distribution function.
Specifically, we report a photometric study of energy-dispersive diffraction
(ED-XRD) for structural measurement of high energy density systems at
large-scale laser facilities such as OMEGA and the National Ignition Facility.
We find that structural information can be obtained in single-shot ED-XRD
experiments using established backlighter and spectrometer technologies.


title:
Theory of the Two-Particle Emission from Superfluid Fermi Gases in the
  BCS-BEC Crossover

abstract:
  We present a theory of the emission of fermion pairs from a superfluid Fermi
gas induced by a photon absorption. In the solid state physics, this type of
process is called double photo-emission (DPE). The spectrum of the induced
two-particle current (or DPE current) provides a direct insight into the
pair-correlation of condensate fermion pairs. We develop a general formalism
for two-particle current induced by DPE by treating the coupling of two Fermi
gases with the time-dependent perturbation theory. This formalism is used to
calculate energy distributions of DPE current from the superfluid Fermi gas in
the BCS-BEC crossover at T=0. We show that the DPE current has distinct
contributions of the condensed pair components and uncorrelated pair states. We
also calculate the angular dependence of DPE current in the BCS-BEC crossover.
The DPE current of the tightly-bound molecules in the BEC regime is found to be
quite deferent from that of the weakly-bound Cooper pairs.


title: A note on linear prediction of large chaotic systems

abstract:
  Reliable prediction of large chaotic sytems in the short to middle time range
is of interest in a number of fields, including climate, ecology, seismology,
and economics. In this paper, results from chaos theory, and statistical theory
are combined to suggest rulse for building linear predictive models of chaotic
systems. The rules are tested on a problems identified as hard in the climate
literature, interseasonal to interannual prediction of regional seasonal
precipitation. In a test of prediction the method yields third season ahead
predictions in 4 regions over 5 seasons which beat the NOAA climate prediction
centers half season predictions for the same region and seasons. In a test
using dimensionless climate patterns to infer parameters of the climate system,
remarkably accurate estimates of increase in average global surface air
temperature are produced.


title:
Algebraic independence of local conjugacies and related questions in
  polynomial dynamics

abstract:
  Let $K$ be an algebraically closed field of characteristic 0 and $f\in K[t]$
a polynomial of degree $d\geq 2$. There exists a local conjugacy $\psi_f(t)\in
tK[[1/t]]$ such that $\psi_f(t^d)=f(\psi_f(t))$. It has been known that
$\psi_f$ is transcendental over $K(t)$ if $f$ is not conjugate to $t^d$ or a
constant multiple of the Chebyshev polynomial. In this paper, we study the
algebraic independence of $\psi_{f_1}$,\ldots,$\psi_{f_n}$ using a recent
result of Medvedev-Scanlon. Related questions in transcendental number theory
and canonical heights in arithmetic dynamics are also discussed.


title:
Exact Riemann solver for ideal magnetohydrodynamics that can handle all
  types of intermediate shocks and switch-on/off waves

abstract:
  We have built a code to obtain the exact solutions of Riemann problems in
ideal magnetohydrodynamics (MHD) for an arbitrary initial condition. The code
can handle not only regular waves but also switch-on/off rarefactions and all
types of non-regular shocks: intermediate shocks and switch-on/off shocks.
Furthermore, the initial conditions with vanishing normal or transverse
magnetic fields can be handled although the code is partly based on the
algorithm proposed by Torrilhon (2002) (Torrilhon 2002 Exact Solver and
Uniqueness Condition for Riemann problems of Ideal Magnetohydrodynamics.
Research report 2002-06, Seminar for Applied Mathematics, ETH, Zurich), which
cannot deal with all types of non-regular waves nor the initial conditions
without normal or transverse magnetic fields. Our solver can find all the
solutions for a given Riemann problem and hence, as demonstrated in this paper,
one can investigate the structure of the solution space in detail. Therefore
the solver is a powerful instrument to solve the outstanding problem of the
existence and uniqueness of solutions of MHD Riemann problems. Moreover, the
solver may be applied to numerical MHD schemes like the Godunov scheme in the
future.


title:
Chargeless spin current for switching and coupling of domain walls in
  magnetic nanowires

abstract:
  The demonstration of the generation and control of a pure spin current
(without net charge flow) by electric fields and/or temperature gradient has
been an essential leap in the quest for low-power consumption electronics. The
key issue of whether and how such a current can be utilized to drive and
control information stored in magnetic domain walls (DWs) is still outstanding
and is addressed here. We demonstrate that pure spin current acts on DWs in a
magnetic stripe with an effective spin-transfer torque resulting in a mutual
DWs separation dynamics and picosecond magnetization reversal. In addition,
long-range ($\sim$ mm) antiferromagnetic DWs coupling emerges. If one DW is
pinned by geometric constriction, the spin current induces a dynamical spin
orbital interaction that triggers an internal electric field determined by
$\vec{E} \sim \hat{e}_{x} \cdot (\vec{n}_{1} \times \vec{n}_{2})$ where
$\vec{n}_{1/2}$ are the effective DWs orientations and $\hat{e}_{x} $ is their
spatial separation vector. This leads to charge accumulation or persistent
electric current in the wire. As DWs are routinely realizable and tuneable, the
predicted effects bear genuine potential for power-saving spintronics devices.


title: Middle-Solving F4 to Compute Grobner bases for Cryptanalysis over GF(2)

abstract:
  Algebraic cryptanalysis usually requires to recover the secret key by solving
polynomial equations. Faugere's F4 is a well-known Grobner bases algorithm to
solve this problem. However, a serious drawback exists in the Grobner bases
based algebraic attacks, namely, any information won't be got if we couldn't
work out the Grobner bases of the polynomial equations system. In this paper,
we in-depth research the F4 algorithm over GF(2). By using S-polynomials to
replace critical pairs and computing the normal form of the productions with
respect to the field equations in certain steps, many "redundant" reductors are
avoided during the computation process of the F4 algorithm. By slightly
modifying the logic of F4 algorithm, we solve the univariate polynomials
appeared in the algorithm and then back-substitute the values of the solved
variables at each iteration of the algorithm. We call our improvements
Middle-Solving F4. The heuristic strategy of Middle-Solving overcomes the
drawback of algebraic attacks and well suits algebraic attacks. It has never
been applied to the Grobner bases algorithm before. Experiments to some Hidden
Field Equation instances and some classical benchmarks (Cyclic 6, Gonnet83)
show that Middle-Solving F4 is faster and uses less memory than Faugere's F4.


title: Electron doping evolution of the magnetic excitations in BaFe2-xNixAs2

abstract:
  We use inelastic neutron scattering (INS) spectroscopy to study the magnetic
excitations spectra throughout the Brioullion zone in electron-doped iron
pnictide superconductors BaFe$_{2-x}$Ni$_{x}$As$_{2}$ with $x=0.096,0.15,0.18$.
While the $x=0.096$ sample is near optimal superconductivity with $T_c=20$ K
and has coexisting static incommensurate magnetic order, the $x=0.15,0.18$
samples are electron-overdoped with reduced $T_c$ of 14 K and 8 K,
respectively, and have no static antiferromagnetic (AF) order. In previous INS
work on undoped ($x=0$) and electron optimally doped ($x=0.1$) samples, the
effect of electron-doping was found to modify spin waves in the parent compound
BaFe$_2$As$_2$ below $\sim$100 meV and induce a neutron spin resonance at the
commensurate AF ordering wave vector that couples with superconductivity. While
the new data collected on the $x=0.096$ sample confirms the overall features of
the earlier work, our careful temperature dependent study of the resonance
reveals that the resonance suddenly changes its $Q$-width below $T_c$ similar
to that of the optimally hole-doped iron pnictides
Ba$_{0.67}$K$_{0.33}$Fe$_2$As$_2$. In addition, we establish the dispersion of
the resonance and find it to change from commensurate to transversely
incommensurate with increasing energy. Upon further electron-doping to
overdoped iron pnictides with $x=0.15$ and 0.18, the resonance becomes weaker
and transversely incommensurate at all energies, while spin excitations above
$\sim$100 meV are still not much affected. Our absolute spin excitation
intensity measurements throughout the Brillouin zone for $x=0.096,0.15,0.18$
confirm the notion that the low-energy spin excitation coupling with itinerant
electron is important for superconductivity in these materials, even though the
high-energy spin excitations are weakly doping dependent.


title: Spin resonance in AFe2Se2 with s-wave pairing symmetry

abstract:
  We study spin resonance in the superconducting state of recently discovered
alkali-intercalated iron selenide materials A_xFe_(2-y)Se_2 (A=K,Rb,Cs) in
which the Fermi surface has only electron pockets. Recent angle-resolved
photoemission spectroscopy (ARPES) studies [M. Xu et al., Phys. Rev. B 85,
220504(R) (2012)] were interpreted as strong evidence for s-wave gap in these
materials, while the observation of the resonance peak in neutron scattering
measurements [G. Friemel et al., Phys. Rev. B 85, 140511 (2012)] suggests that
the gap must have different signs at Fermi surface points connected by the
momentum at which the resonance has been observed. We consider recently
proposed unconventional s+- superconducting state of A_xFe_(2-y)Se_2 with
superconducting gap changing sign between the hybridized electron pockets. We
argue that such a state supports a spin resonance. We compute the dynamical
structure factor and show that it is consistent with the results of inelastic
neutron scattering.


title:
Solvable Many-Body Models of Goldfish Type with One-, Two- and
  Three-Body Forces

abstract:
  The class of solvable many-body problems "of goldfish type" is extended by
including (the additional presence of) three-body forces. The solvable $N$-body
problems thereby identified are characterized by Newtonian equations of motion
featuring 19 arbitrary "coupling constants". Restrictions on these constants
are identified which cause these systems - or appropriate variants of them - to
be isochronous or asymptotically isochronous, i.e. all their solutions to be
periodic with a fixed period (independent of the initial data) or to have this
property up to contributions vanishing exponentially as $t\rightarrow\infty$.


title:
Universal Limit Theorems in Graph Coloring Problems With Connections to
  Extremal Combinatorics

abstract:
  This paper proves limit theorems for the number of monochromatic edges in
uniform random colorings of general random graphs. These can be seen as
generalizations of the birthday problem (what is the chance that there are two
friends with the same birthday?). It is shown that if the number of colors
grows to infinity, the asymptotic distribution is either a Poisson mixture or a
Normal depending solely on the limiting behavior of the ratio of the number of
edges in the graph and the number of colors. This result holds for any graph
sequence, deterministic or random. On the other hand, when the number of colors
is fixed, a necessary and sufficient condition for asymptotic normality is
determined. Finally, using some results from the emerging theory of dense graph
limits, the asymptotic (non-normal) distribution is characterized for any
converging sequence of dense graphs. The proofs are based on moment
calculations which relate to the results of Erd\H os and Alon on extremal
subgraph counts. As a consequence, a simpler proof of a result of Alon,
estimating the number of isomorphic copies of a cycle of given length in graphs
with a fixed number of edges, is presented.


title:
Exact Pathwise and Mean--Square Asymptotic Behaviour of Stochastic
  Affine Volterra and Functional Differential Equations

abstract:
  The almost sure rate of exponential-polynomial growth or decay of affine
stochastic Volterra and affine stochastic finite-delay equations is
investigated. These results are achieved under suitable smallness conditions on
the intensities of the deterministic and stochastic perturbations diffusion,
given that the asymptotic behaviour of the underlying deterministic resolvent
is determined by the zeros of its characteristic equation. The results rely
heavily upon a stochastic variant of the admissibility theory for linear
Volterra operators.


title: Certified proofs in programs involving exceptions

abstract:
  Exception handling is provided by most modern programming languages. It
allows to deal with anomalous or exceptional events which require special
processing. In computer algebra, exception handling is an efficient way to
implement the dynamic evaluation paradigm: for instance, in linear algebra,
dynamic evaluation can be used for applying programs which have been written
for matrices with coefficients in a field to matrices with coefficients in a
ring. Thus, a proof system for computer algebra should include a treatement of
exceptions, which must rely on a careful description of a semantics of
exceptions. The categorical notion of monad can be used for formalizing the
raising of exceptions: this has been proposed by Moggi and implemented in
Haskell. In this paper, we provide a proof system for exceptions which involves
both raising and handling, by extending Moggi's approach. Moreover, the core
part of this proof system is dual to a proof system for side effects in
imperative languages, which relies on the categorical notion of comonad. Both
proof systems are implemented in the Coq proof assistant.


title:
Long Memory and Financial Market Bubble Dynamics in Affine Stochastic
  Differential Equations with Average Functionals

abstract:
  In this paper we consider the growth, large fluctuations and memory
properties of an affine stochastic functional differential equation with an
average functional where the contributions of the average and instantaneous
terms are parameterised. An asymptotic analysis of the solution of this
equation is conducted for all values of the parameters of the equation. When
solutions are recurrent, we show that the autocovariance function of the
solution decays at a polynomial rate, even though the solution is
asymptotically equal to another asymptotically stationary process whose
autocovariance function decays exponentially. It is shown that when solutions
grow, they do so at either a polynomial or exponential rate in time depending
on the sign of a parameter of the model, modulo some exceptional parameter
sets. On these exceptional sets, solutions are recurrent on the real line with
large fluctuations consistent with the Law of the Iterated logarithm, or
exhibit subexponential yet superpolynomial growth.


title: Filamentation instability of counter-streaming laser-driven plasmas

abstract:
  Filamentation due to the growth of a Weibel-type instability was observed in
the interaction of a pair of counter-streaming, ablatively-driven plasma flows,
in a supersonic, collisionless regime relevant to astrophysical collisionless
shocks. The flows were created by irradiating a pair of opposing plastic (CH)
foils with 1.8 kJ, 2-ns laser pulses on the OMEGA EP laser system. Ultrafast
laser-driven proton radiography was used to image the Weibel-generated
electromagnetic fields. The experimental observations are in good agreement
with the analytical theory of the Weibel instability and with particle-in-cell
simulations.


title:
Improved Coincident and Coherent Detection Statistics for Searches for
  Gravitational Wave Ringdown Signals

abstract:
  We study an improved method for detecting gravitational wave (GW) signals
from perturbed black holes by earth-based detectors in the quest for searching
for intermediate-mass black holes (IMBHs). Such signals, called ringdowns, are
damped sinusoids whose frequency and damping constant can be used to measure a
black hole's mass and spin. Utilizing the output from a matched filter analysis
pipeline, we present an improved statistic for the detection of a ringdown
signal that is found to be coincident in multiple detectors. The statistic
addresses the non-Gaussianity of the data without the use of an additional
signal-based waveform consistency test. We also develop coherent network
statistics to check for consistency of signal amplitudes and phases in the
different detectors with their different orientations and signal arrival times.
We find that the detection efficiency can be improved at least by a few tens of
percent by applying these multi-detector statistics primarily because of the
ineffectiveness of single-detector based discriminators of non-stationary
noise, such as the chi-square test, in the case of ringdown signals studied
here.


title: Dejavu: An Accurate Energy-Efficient Outdoor Localization System

abstract:
  We present Dejavu, a system that uses standard cell-phone sensors to provide
accurate and energy-efficient outdoor localization suitable for car navigation.
Our analysis shows that different road landmarks have a unique signature on
cell-phone sensors; For example, going inside tunnels, moving over bumps, going
up a bridge, and even potholes all affect the inertial sensors on the phone in
a unique pattern. Dejavu employs a dead-reckoning localization approach and
leverages these road landmarks, among other automatically discovered abundant
virtual landmarks, to reset the accumulated error and achieve accurate
localization. To maintain a low energy profile, Dejavu uses only
energy-efficient sensors or sensors that are already running for other
purposes. We present the design of Dejavu and how it leverages crowd-sourcing
to automatically learn virtual landmarks and their locations. Our evaluation
results from implementation on different android devices in both city and
highway driving show that Dejavu can localize cell phones to within 8.4m median
error in city roads and 16.6m on highways. Moreover, compared to GPS and other
state-of-the-art systems, Dejavu can extend the battery lifetime by 347%,
achieving even better localization results than GPS in the more challenging
in-city driving conditions.


title:
On the Classification of the Asymptotic Behaviour of Solutions of
  Globally Stable Scalar Differential Equations with Respect to
  State--Independent Stochastic Perturbations

abstract:
  In this paper we characterise the global stability, global boundedness and
recurrence of solutions of a scalar nonlinear stochastic differential equation.
The differential equation is a perturbed version of a globally stable
autonomous equation with unique equilibrium where the diffusion coefficient is
independent of the state. We give conditions which depend on the rate of decay
of the noise intensity under which solutions either (a) tend to the equilibrium
almost surely, (b) are bounded almost surely but tend to zero with probability
zero, (c) or are recurrent on the real line almost surely. We also show that no
other types of asymptotic behaviour are possible. Connections between the
conditions which characterise the various classes of long--run behaviour and
simple sufficient conditions are explored, as well as the relationship between
the size of fluctuations and the strength of the mean reversion and diffusion
coefficient, in the case when solutions are a.s. bounded.


title:
Extinction of the N=20 neutron-shell closure for 32Mg examined by direct
  mass measurements

abstract:
  The 'island of inversion' around $^{32}$Mg is one of the most important
paradigm for studying the disappearance of the stabilizing 'magic' of a shell
closure. We present the first Penning-trap mass measurements of the exotic
nuclides $^{29-31}$Na and $^{30-34}$Mg, which allow a precise determination of
the empirical shell gap for $^{32}$Mg. The new value of 1.10(3) MeV is the
lowest observed shell gap for any nuclide with a canonical magic number.


title:
Classification of the Asymptotic Behaviour of Globally Stable Linear
  Differential Equations with Respect to State-independent Stochastic
  Perturbations

abstract:
  In this paper we consider the global stability of solutions of an affine
stochastic differential equation. The differential equation is a perturbed
version of a globally stable linear autonomous equation with unique zero
equilibrium where the diffusion coefficient is independent of the state. We
find necessary and sufficient conditions on the rate of decay of the noise
intensity for the solution of the equation to be globally asymptotically
stable, stable but not asymptotically stable, and unstable, each with
probability one. In the case of stable or bounded solutions, or when solutions
are a.s. unstable asymptotically stable in mean square, it follows that the
norm of the solution has zero liminf, by virtue of the fact that $\|X\|^2$ has
zero pathwise average a.s. Sufficient conditions guaranteeing the different
types of asymptotic behaviour which are more readily checked are developed. It
is also shown that noise cannot stabilise solutions, and that the results can
be extended in all regards to affine stochastic differential equations with
periodic coefficients.


title: Two principles in many-valued logic

abstract:
  Classically, two propositions are logically equivalent precisely when they
are true under the same logical valuations. Also, two logical valuations are
distinct if, and only if, there is a formula that is true according to one
valuation, and false according to the other. By a real-valued logic we mean a
many-valued logic in the sense of Petr H\'ajek that is complete with respect to
a subalgebra of truth values of a BL-algebra given by a continuous triangular
norm on [0, 1]. Abstracting the two foregoing properties from classical logic
leads us to two principles that a real-valued logic may or may not satisfy. We
prove that the two principles are sufficient to characterise {\L}ukasiewicz and
G\"odel logic, to within extensions. We also prove that, under the additional
assumption that the set of truth values be closed in the Euclidean topology of
[0,1], the two principles also afford a characterisation of Product logic.


title:
Classification of the Asymptotic Behaviour of Globally Stable
  Differential Equations with Respect to State-independent Stochastic
  Perturbations

abstract:
  In this paper we consider the global stability of solutions of a nonlinear
stochastic differential equation. The differential equation is a perturbed
version of a globally stable linear autonomous equation with unique zero
equilibrium where the diffusion coefficient is independent of the state.
Contingent on a dissipative condition characterising the asymptotic stability
of the unperturbed equation, necessary and sufficient conditions on the rate of
decay of the noise intensity for the solution of the equation to be a.s.
globally asymptotically stable, contingent on some weak and noise independent
reversion towards the equilibrium when the solution is far from equilibrium.
Under a stronger equilibrium reverting condition, we may classify whether the
solution globally asymptotically stable, stable but not asymptotically stable,
and unstable, each with probability one purely in terms of the asymptotic
intensity of the noise. Sufficient conditions guaranteeing the different types
of asymptotic behaviour which are more readily checked are developed.


title:
Multifractal Analysis of Ergodic Averages in Some Nonuniformly
  Hyperbolic Systems

abstract:
  This article is devoted to the study of the multifractal analysis of ergodic
averages in some nonuniformly hyperbolic systems. In particular, our results
hold for the robust classes of multidimensional nonuniformly expanding local
diffeomorphisms and Viana maps.


title:
On the almost sure running maxima of solutions of affine neutral
  stochastic functional differential equations

abstract:
  This paper studies the large fluctuations of solutions of finite--dimensional
affine stochastic neutral functional differential equations with finite memory,
as well as related nonlinear equations. We find conditions under which the
exact almost sure growth rate of the running maximum of each component of the
system can be determined, both for affine and nonlinear equations. The proofs
exploit the fact that an exponentially decaying fundamental solution of the
underlying deterministic equation is sufficient to ensure that the solution of
the affine equation converges to a stationary Gaussian process.


title: The Generalized Traveling Salesman Problem solved with Ant Algorithms

abstract:
  A well known N P-hard problem called the Generalized Traveling Salesman
Problem (GTSP) is considered. In GTSP the nodes of a complete undirected graph
are partitioned into clusters. The objective is to find a minimum cost tour
passing through exactly one node from each cluster. An exact exponential time
algorithm and an effective meta-heuristic algorithm for the problem are
presented. The meta-heuristic proposed is a modified Ant Colony System (ACS)
algorithm called Reinforcing Ant Colony System (RACS) which introduces new
correction rules in the ACS algorithm. Computational results are reported for
many standard test problems. The proposed algorithm is competitive with the
other already proposed heuristics for the GTSP in both solution quality and
computational time.


title: Algebraic Message Authentication Codes

abstract:
  This paper suggests a message authentication scheme, which can be efficiently
used for secure digital signature creation. The algorithm used here is an
adjusted union of the concepts which underlie projective geometry and group
structure on circles. The authentication is done through a key, which iterates
over the complete message string to produce the signature. The iteration is not
only based on the frequency distribution of the message string alphabet, but
also on the probability of occurrence of another given reference string in the
message. The complete process can be easily computed in a small time, producing
signatures which are highly dependent on the message string. Consequently, the
odds in favor of existence of a forgery are highly reduced.


title:
On the Existence and Uniqueness of Solutions of Stochastic Equations of
  Neutral Type

abstract:
  This paper considers some the existence and uniqueness of strong solutions of
stochastic neutral functional differential equations. The conditions on the
neutral functional relax those commonly used to establish the existence and
uniqueness of solutions of NSFDEs for many important classes of functional, and
parallel the conditions used to ensure existence and uniqueness of solutions of
related deterministic neutral equations. Exponential estimates on the almost
sure and p--th mean rate of growth of solutions under the weaker existence
conditions are also given.


title: A note on the 3-rainbow index of $K_{2,t}$

abstract:
  A tree $T$, in an edge-colored graph $G$, is called {\em a rainbow tree} if
no two edges of $T$ are assigned the same color. For a vertex subset $S\in
V(G)$, a tree that connects $S$ in $G$ is called an $S$-tree. A {\em
$k$-rainbow coloring} of $G$ is an edge coloring of $G$ having the property
that for every set $S$ of $k$ vertices of $G$, there exists a rainbow $S$-tree
$T$ in $G$. The minimum number of colors needed in a $k$-rainbow coloring of
$G$ is the {\em $k$-rainbow index of $G$}, denoted by $rx_k(G)$. In this paper,
we obtain the exact values of $rx_3(K_{2,t})$ for any $t\geq 1$.


title: Quality of Service Games for Spectrum Sharing

abstract:
  Today's wireless networks are increasingly crowded with an explosion of
wireless users, who have greater and more diverse quality of service (QoS)
demands than ever before. However, the amount of spectrum that can be used to
satisfy these demands remains finite. This leads to a great challenge for
wireless users to effectively share the spectrum to achieve their QoS
requirements. This paper presents a game theoretic model for spectrum sharing,
where users seek to satisfy their QoS demands in a distributed fashion. Our
spectrum sharing model is quite general, because we allow different wireless
channels to provide different QoS, depending upon their channel conditions and
how many users are trying to access them. Also, users can be highly
heterogeneous, with different QoS demands, depending upon their activities,
hardware capabilities, and technology choices. Under such a general setting, we
show that it is NP hard to find a spectrum allocation which satisfies the
maximum number of users' QoS requirements in a centralized fashion. We also
show that allowing users to self-organize through distributed channel
selections is a viable alternative to the centralized optimization, because
better response updating is guaranteed to reach a pure Nash equilibria in
polynomial time. By bounding the price of anarchy, we demonstrate that the
worst case pure Nash equilibrium can be close to optimal, when users and
channels are not very heterogenous. We also extend our model by considering the
frequency spatial reuse, and consider the user interactions as a game upon a
graph where players only contend with their neighbors. We prove that better
response updating is still guaranteed to reach a pure Nash equilibrium in this
more general spatial QoS satisfaction game.


title: Some upper bounds for 3-rainbow index of graphs

abstract:
  A tree $T$, in an edge-colored graph $G$, is called {\em a rainbow tree} if
no two edges of $T$ are assigned the same color. A {\em $k$-rainbow coloring}of
$G$ is an edge coloring of $G$ having the property that for every set $S$ of
$k$ vertices of $G$, there exists a rainbow tree $T$ in $G$ such that
$S\subseteq V(T)$. The minimum number of colors needed in a $k$-rainbow
coloring of $G$ is the {\em $k$-rainbow index of $G$}, denoted by $rx_k(G)$. In
this paper, we consider 3-rainbow index $rx_3(G)$ of $G$. We first show that
for connected graph $G$ with minimum degree $\delta(G)\geq 3$, the tight upper
bound of $rx_3(G)$ is $rx_3(G[D])+4$, where $D$ is the connected 2-dominating
set of $G$. And then we determine a tight upper bound for $K_{s,t}(3\leq s\leq
t)$ and a better bound for $(P_5,C_5)$-free graphs. Finally, we obtain a sharp
bound for 3-rainbow index of general graphs.


title:
Exact growth rates of solutions of delay--dominated differential
  equations with regularly varying coefficients

abstract:
  In this paper we determine the exact rate of growth of the solution of a
deterministic delay differential equation in which the delayed term is
regularly varying at infinity and dominates, and determine criteria to
characterise this dominance. The preservation of growth rates using a uniform
step size Euler scheme is also discussed.


title:
SurpriseMe: an integrated tool for network community structure
  characterization using Surprise maximization

abstract:
  Detecting communities, densely connected groups may contribute to unravel the
underlying relationships among the units present in diverse biological networks
(e.g., interactome, coexpression networks, ecological networks, etc.). We
recently showed that communities can be very precisely characterized by
maximizing Surprise, a global network parameter. Here we present SurpriseMe, a
tool that integrates the outputs of seven of the best algorithms available to
estimate the maximum Surprise value. SurpriseMe also generates distance
matrices that allow to visualize the relationships among the solutions
generated by the algorithms. We show that the communities present in small and
medium-sized networks, with up to 10.000 nodes, can be easily characterized: on
standard PC computers, these analyses take less than an hour. Also, four of the
algorithms may quite rapidly analyze networks with up to 100.000 nodes, given
enough memory resources. Because of its performance and simplicity, SurpriseMe
is a reference tool for community structure characterization.


title:
On the Dynamic Consistency of the Split Step Method for Classifying the
  Asymptotic Behaviour of Globally Stable Differential Equations perturbed by
  State--independent Stochastic terms

abstract:
  In this paper we classify the pathwise asymptotic behaviour of the
discretisation of a general autonomous scalar differential equation which has a
unique and globally stable equilibrium. The underlying continuous equation is
subjected to a stochastic perturbation whose intensity is state--independent.
In the main result, it is shown that when the split--step--method is applied to
the resulting stochastic differential equation, and the stochastic intensity is
decreasing, the solutions of the discretised equation inherit the asymptotic
behaviour of the continuous equation, regardless of whether the continuous
equation has stable, bounded but unstable, or unbounded solutions, provided the
step size is chosen sufficiently small.


title: Ioana's superrigidity theorem and orbit equivalence relations

abstract:
  In this expository article, we give a survey of Adrian Ioana's cocycle
superrigidity theorem for profinite actions of Property (T) groups, and its
applications to ergodic theory and set theory. In addition to a statement and
proof of Ioana's theorem, this article features:
  * An introduction to rigidity, including a crash course in Borel cocycles and
a summary of some of the best-known superrigidity theorems;
  * Some easy applications of superrigidity, both to ergodic theory (orbit
equivalence) and set theory (Borel reducibility); and
  * A streamlined proof of Simon Thomas's theorem that the classification of
torsion-free abelian groups of finite rank is intractable.


title: Memoryless nonlinear response: A simple mechanism for the 1/f noise

abstract:
  Discovering the mechanism underlying the ubiquity of $"1/f^{\alpha}"$ noise
has been a long--standing problem. The wide range of systems in which the
fluctuations show the implied long--time correlations suggests the existence of
some simple and general mechanism that is independent of the details of any
specific system. We argue here that a {\it memoryless nonlinear response}
suffices to explain the observed non--trivial values of $\alpha$: a random
input noisy signal $S(t)$ with a power spectrum varying as $1/f^{\alpha'}$,
when fed to an element with such a response function $R$ gives an output
$R(S(t))$ that can have a power spectrum $1/f^{\alpha}$ with $\alpha <
\alpha'$. As an illustrative example, we show that an input Brownian noise
($\alpha'=2$) acting on a device with a sigmoidal response function $R(S)=
\sgn(S)|S|^x$, with $x<1$, produces an output with $\alpha = 3/2 +x$, for $0
\leq x \leq 1/2$. Our discussion is easily extended to more general types of
input noise as well as more general response functions.


title: Survey on Modelling Methods Applicable to Gene Regulatory Network

abstract:
  Gene Regulatory Network (GRN) plays an important role in knowing insight of
cellular life cycle. It gives information about at which different
environmental conditions genes of particular interest get over expressed or
under expressed. Modelling of GRN is nothing but finding interactive
relationships between genes. Interaction can be positive or negative. For
inference of GRN, time series data provided by Microarray technology is used.
Key factors to be considered while constructing GRN are scalability,
robustness, reliability and maximum detection of true positive interactions
between genes. This paper gives detailed technical review of existing methods
applied for building of GRN along with scope for future work.


title: Geodesic completeness of generalized space-times

abstract:
  We define the notion of geodesic completeness for semi-Riemannian metrics of
low regularity in the framework of the geometric theory of generalized
functions. We then show completeness of a wide class of impulsive gravitational
wave space-times.


title:
Atomic mechanism of phase transition between metallic and semiconducting
  MoS2 single-layers

abstract:
  Structural transformation between metallic (1T) and semiconducting (2H)
phases of single-layered MoS2 was systematically investigated by an in situ
STEM with atomic precision. The 1T/2H phase transition is comprised of S and/or
Mo atomic-plane glides, and requires an intermediate phase ({\alpha}-phase) as
an indispensable precursor. Migration of two kinds of boundaries ({\beta} and
{\gamma}-boundaries) is also found to be responsible for the growth of the
second phase. The 1T phase can be intentionally introduced in the 2H matrix by
using a high dose of incident electron beam during heating the MoS2
single-layers up to 400~700{\deg}C in high vacuum and indeed controllable in
size. This work may lead to the possible fabrication of composite nano-devices
made of local domains with distinct electronic properties.


title: On the phase transition of the 3D random field Ising model

abstract:
  We present numerical simulations of the random field Ising model in three
dimensions at zero temperature. The critical exponents are found to agree with
previous results. We study the magnetic susceptibility by applying a small
magnetic field perturbation. We find that the critical amplitude ratio of the
magnetic susceptibilities to be very large, equal to 233.1 \pm 1.5. We find
strong sample to sample fluctuations which obey finite size scaling. The
probability distribution of the size of small energy excitations is maximally
non-self averaging, obeying a double peak distribution, and is finite size
scaling invariant. We also study the approach to the thermodynamic limit of the
ground state magnetization at the phase transition.


title: The Unified Approach For Organizational Network Vulnerability Assessment

abstract:
  The present business network infrastructure is quickly varying with latest
servers, services, connections, and ports added often, at times day by day, and
with a uncontrollably inflow of laptops, storage media and wireless networks.
With the increasing amount of vulnerabilities and exploits coupled with the
recurrent evolution of IT infrastructure, organizations at present require more
numerous vulnerability assessments. In this paper new approach the Unified
process for Network vulnerability Assessments hereafter called as a unified NVA
is proposed for network vulnerability assessment derived from Unified Software
Development Process or Unified Process, it is a popular iterative and
incremental software development process framework.


title:
Properties of Individual Dopant Atoms in Single-Layer MoS2: Atomic
  Structure, Migration, and Enhanced Reactivity

abstract:
  The differences in the behavior of Re (n-type) and Au (p-type) dopant atoms
in single-layered MoS2 were investigated by in situ scanning transmission
electron microscopy. Re atoms tend to occupy Mo sites, while Au atoms exist as
adatoms and show larger mobility under the electron beam. Re substituted to Mo
site showed enhanced chemical affinity, evidenced by agglomeration of Re
adatoms around these sites. This may explain the difficulties in achieving a
high compositional rate of homogeneous Re doping in MoS2. In addition, an in
situ coverage experiment together with density functional theory calculations
discovered a high surface reactivity and agglomeration of other impurity atoms
such as carbon at the Re doped sites.


title: Handy Annotations within Oracle 10g

abstract:
  This paper describes practical observations during the Database system Lab.
Oracle 10g DBMS is used in the data base system lab and performed SQL queries
based many concepts like Data Definition Language Commands (DDL), Data
Modification Language Commands ((DML), Views, Integrity Constraints, Aggregate
functions, Joins and Abstract type . While performing practical during the lab
session, many problems occurred, in order to solve them many text books and
websites referred but could not obtain expected help from them. Even though by
spending much time in the database labs with Oracle 10g, tried in numerous
ways, as a final point expected output is achieved. This paper describes
annotations which were experimentally proved in the Database lab.


title: Laundering Money Online: a review of cybercriminals methods

abstract:
  Money laundering is a critical step in the cyber crime process which is
experiencing some changes as hackers and their criminal colleagues continually
alter and optimize payment mechanisms. Conducting quantitative research on
underground laundering activity poses an inherent challenge: Bad guys and their
banks do not share information on criminal pursuits. However, by analyzing
forums, we have identified two growth areas in money laundering: online gaming
and micro laundering.


title: Semi Symmetric Method Of SAN Storage Virtualization

abstract:
  Virtualization is one of the biggest buzzwords of the technology industry
right at this moment. The fast growth in storage capacity and processing power
in enterprise installations coupled with the need for high availability,
requires Storage Area Network (SAN) architecture to provide seamless addition
of storage and performance elements without downtime. The usual goal of
virtualization is to centralize administrative tasks while improving
scalability and work loads. This paper, describing about new proposed method
for virtualization, which would be overcome limitations of existed methods for
storage virtualization


title: On Milnor classes via invariants of singular subschemes

abstract:
  We derive a formula for the Milnor class of scheme-theoretic global complete
intersections (with arbitrary singularities) in a smooth variety in terms of
the Segre class of its singular scheme. In codimension one the formula recovers
a formula of Aluffi for the Milnor class of a hypersurface.


title: No greedy bases for matrix spaces with mixed $\ell_p$ and $\ell_q$ norms

abstract:
  We show that non of the spaces $(\bigoplus_{n=1}^\infty\ell_p)_{\ell_q}$,
$1\le p\not= q<\infty$, have a greedy basis. This solves a problem raised by
Dilworth, Freeman, Odell and Schlumprect. Similarly, the spaces
$(\bigoplus_{n=1}^\infty\ell_p)_{c_0}$, $1\le p<\infty$, and
$(\bigoplus_{n=1}^\infty c_o)_{\ell_q}$, $1\le q<\infty$, do not have greedy
bases. It follows from that and known results that a class of Besov spaces on
$\R^n$ lack greedy bases as well.


title: Bias-Hardened CMB Lensing with Polarization

abstract:
  Polarization data will soon provide the best avenue for measurements of the
CMB lensing potential, although it is potentially sensitive to several
instrumental effects including beam asymmetry, polarization angle
uncertainties, sky coverage, as well as analysis choices such as masking. We
derive "bias-hardened" lensing estimators to mitigate these effects, at the
expense of somewhat larger reconstruction noise, and test them numerically on
simulated data. We find that the mean-field bias from masking is significant
for the EE quadratic lensing estimator, however the bias-hardened estimator
combined with filtering techniques can mitigate the mean field. On the other
hand, the EB estimator does not significantly suffer from the mean-field from
the point source masking and survey window function. The contamination from
beam asymmetry and polarization angle uncertainties, however, can generate
mean-field biases for the EB estimator. These can also be mitigated using
bias-hardened estimators, with at most a factor of ~ 3 degradation of noise
level compared to the conventional approach.


title: Multiferroicity in the geometrically frustrated FeTe2O5Cl

abstract:
  The layered FeTe2O5Cl compound was studied by specific-heat, muon spin
relaxation, nuclear magnetic resonance, dielectric, as well as neutron and
synchrotron x-ray diffraction measurements, and the results were compared to
isostructural FeTe2O5Br. We find that the low-temperature ordered state,
similarly as in FeTe2O5Br, is multiferroic - the elliptical amplitude-modulated
magnetic cycloid and the electric polarization simultaneously develop below 11
K. However, compared to FeTe2O5Br, the magnetic elliptical envelop rotates by
75(4) deg and the orientation of the electric polarization is much more
sensitive to the applied electric field. We propose that the observed
differences between the two isostructural compounds arise from geometric
frustration, which enhances the effects of otherwise subtle Fe3+ (S = 5/2)
magnetic anisotropies. Finally, x-ray diffraction results imply that, on the
microscopic scale, the magnetoelectric coupling is driven by shifts of the O1
atoms, as a response to the polarization of the Te4+ lone-pair electrons
involved in the Fe-O-Te-O-Fe exchange bridges.


title: Covariant perturbations through a simple non-singular bounce

abstract:
  In this paper we study the evolution of cosmological perturbations through a
nonsingular bouncing universe using covariant perturbation theory and examine
the validity of linear perturbation theory. The bounce is modeled by a two
component perfect fluid. Gauge invariant perturbations are defined in terms of
the comoving observers. The scalar and vector perturbations become singular at
the turning point, which is the boundary of the spacetime region where the null
energy condition is violated. Nonadiabatic modes of comoving curvature
perturbation diverge at the turning point. The gravitational waves oscillate
around the bounce and the turning point. By computing the growth of linearity
parameters, it has been shown that the perturbations do not remain linear at
the turning point. We also study the matching conditions on scalar
perturbations and $\mv$, related to the spatial curvature perturbation, is
found to be the appropriate variable to be matched across transition surface.


title: Web Usage Mining: Pattern Discovery and Forecasting

abstract:
  Web usage mining: automatic discovery of patterns in clickstreams and
associated data collected or generated as a result of user interactions with
one or more Web sites. This paper describes web usage mining for our college
log files to analyze the behavioral patterns and profiles of users interacting
with a Web site. The discovered patterns are represented as clusters that are
frequently accessed by groups of visitors with common interests. In this paper,
the visitors and hits were forecasted to predict the further access statistics.


title: Constraints on millicharged particles from Planck

abstract:
  We revisit cosmic microwave background (CMB) constraints on the abundance of
millicharged particles based on the Planck data. The stringent limit
Omega_{mcp}h^2 < 0.001 (95% CL) may be set using the CMB data alone if
millicharged particles participate in the acoustic oscillations of
baryon-photon plasma at the recombination epoch. The latter condition is valid
for a wide region of charges and masses of the particles. Adding the
millicharged component to LCDM shifts prefered scalar spectral index of
primordial perturbations to somewhat larger values as compared to minimal
model, even approaching Harrison-Zeldovich spectrum under some assumptions.


title:
Number theoretic applications of a class of Cantor series fractal
  functions,I

abstract:
  Suppose that $(P,Q) \in \mathbb{N}_2^{\mathbb{N}} \times
\mathbb{N}_2^{\mathbb{N}}$ and $x=E_0.E_1E_2\cdots$ is the $P$-Cantor series
expansion of $x \in \mathbb{R}$. We define $\psi_{P,Q}(x):=\sum_{n=1}^\infty
\frac {\min(E_n,q_n-1)} {q_1 \cdots q_n}$. The functions $\psi_{P,Q}$ are used
to construct many pathological examples of normal numbers. These constructions
are used to give the complete containment relation between the sets of
$Q$-normal, $Q$-ratio normal, and $Q$-distribution normal numbers and their
pairwise intersections for fully divergent $Q$ that are infinite in limit. We
analyze the H\"older continuity of $\psi_{P,Q}$ restricted to some judiciously
chosen fractals. This allows us to compute the Hausdorff dimension of some sets
of numbers defined through restrictions on their Cantor series expansions. In
particular, the main theorem of a paper by Y. Wang {\it et al.}
\cite{WangWenXi} is improved.
  Properties of the functions $\psi_{P,Q}$ are also analyzed. Multifractal
analysis is given for a large class of these functions and continuity is fully
characterized. We also study the behavior of $\psi_{P,Q}$ on both rational and
irrational points, monotonicity, and bounded variation. For different classes
of ergodic shift invariant Borel probability measures $\mu_1$ and $\mu_2$ on
$\mathbb{N}_2^{\mathbb{N}}$, we study which of these properties $\psi_{P,Q}$
satisfies for $\mu_1 \times \mu_2$-almost every $(P,Q) \in
\mathbb{N}_2^{\mathbb{N}} \times \mathbb{N}_2^{\mathbb{N}}$. Related classes of
random fractals are also studied.


title: Irrelevant Vertices for the Planar Disjoint Paths Problem

abstract:
  The Disjoint Paths Problem asks, given a graph $G$ and a set of pairs of
terminals $(s_{1},t_{1}),\ldots,(s_{k},t_{k})$, whether there is a collection
of $k$ pairwise vertex-disjoint paths linking $s_{i}$ and $t_{i}$, for
$i=1,\ldots,k.$ In their $f(k)\cdot n^{3}$ algorithm for this problem,
Robertson and Seymour introduced the irrelevant vertex technique according to
which in every instance of treewidth greater than $g(k)$ there is an
"irrelevant" vertex whose removal creates an equivalent instance of the
problem. This fact is based on the celebrated Unique Linkage Theorem, whose -
very technical - proof gives a function $g(k)$ that is responsible for an
immense parameter dependence in the running time of the algorithm. In this
paper we give a new and self-contained proof of this result that strongly
exploits the combinatorial properties of planar graphs and achieves
$g(k)=O(k^{3/2}\cdot 2^{k}).$ Our bound is radically better than the bounds
known for general graphs.


title:
Number theoretic applications of a class of Cantor series fractal
  functions, II

abstract:
  It is well known that all numbers that are normal of order $k$ in base $b$
are also normal of all orders less than $k$. Another basic fact is that every
real number is normal in base $b$ if and only if it is simply normal in base
$b^k$ for all $k$. This may be interpreted to mean that a number is normal in
base $b$ if and only if all blocks of digits occur with the desired relative
frequency along every infinite arithmetic progression. We reinterpret these
theorems for the $Q$-Cantor series expansions and show that they are no longer
true in a particularly strong way. The main theoretical result of this paper
will be to reduce the problem of constructing normal numbers with certain
pathological properties to the problem of solving a system of Diophantine
relations.


title: A universal operator on the Gurarii space

abstract:
  We construct a nonexpansive linear operator on the Gurarii space that
"captures" all nonexpansive linear operators between separable Banach spaces.
Some additional properties involving its restrictions to finite-dimensional
subspaces describe this operator uniquely up to an isometry.


title:
MDR Codes: A New Class of RAID-6 Codes with Optimal Rebuilding and
  Encoding

abstract:
  As storage systems grow in size, device failures happen more frequently than
ever before. Given the commodity nature of hard drives employed, a storage
system needs to tolerate a certain number of disk failures while maintaining
data integrity, and to recover lost data with minimal interference to normal
disk I/O operations. RAID-6, which can tolerate up to two disk failures with
the minimum redundancy, is becoming widespread. However, traditional RAID-6
codes suffer from high disk I/O overhead during recovery. In this paper, we
propose a new family of RAID-6 codes, the Minimum Disk I/O Repairable (MDR)
codes, which achieve the optimal disk I/O overhead for single failure
recoveries. Moreover, we show that MDR codes can be encoded with the minimum
number of bit-wise XOR operations. Simulation results show that MDR codes help
to save about half of disk read operations than traditional RAID-6 codes, and
thus can reduce the recovery time by up to 40%.


title: Large time behavior of the heat kernel

abstract:
  In this paper, we study the large time behavior of the heat kernel on
complete Riemannian manifolds with nonnegative Ricci curvature, which was
studied by P. Li with additional maximum volume growth assumption. Following Y.
Ding's original strategy, by blowing down the metric, using Cheeger and
Colding's theory about limit spaces of Gromov-Hausdorff convergence, combining
with the Gaussian upper bound of heat kernel on limit spaces, we succeed in
reducing the limit behavior of the heat kernel on manifold to the values of
heat kernels on tangent cones at infinity of manifold with renormalized
measure. As one application, we get the consistent large time limit of heat
kernel in more general context, which generalizes the former result of P. Li.
Furthermore, by choosing different sequences to blow down the suitable metric,
we show the first example manifold whose heat kernel has inconsistent limit
behavior, which answers an open question posed by P. Li negatively.


title:
Stationary Wigner Equation with Inflow Boundary Conditions: Will a
  Symmetric Potential Yield a Symmetric Solution?

abstract:
  Based on the well-posedness of the stationary Wigner equation with inflow
boundary conditions given in (A. Arnold, H et al. J. Math. Phys., 41, 2000), we
prove without any additional prerequisite conditions that the solution of the
Wigner equation with symmetric potential and inflow boundary conditions will be
symmetric. This improve the result in (D. Taj et al. Europhys. Lett., 74, 2006)
which depends on the convergence of solution formulated in the Neumann series.
By numerical studies, we present the convergence of the numerical solution to
the symmetric profile for three different numerical schemes. This implies that
the upwind schemes can also yield a symmetric numerical solution, on the
contrary to the argument given in (D. Taj et al. Europhys. Lett., 74, 2006).


title:
Constraints on cosmic strings from the LIGO-Virgo gravitational-wave
  detectors

abstract:
  Cosmic strings can give rise to a large variety of interesting astrophysical
phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by
cusps are a promising observational signature. In this Letter we present a
search for GWs from cosmic string cusps in data collected by the LIGO and Virgo
gravitational wave detectors between 2005 and 2010, with over 625 days of live
time. We find no evidence of GW signals from cosmic strings. From this result,
we derive new constraints on cosmic string parameters, which complement and
improve existing limits from previous searches for a stochastic background of
GWs from cosmic microwave background measurements and pulsar timing data. In
particular, if the size of loops is given by the gravitational backreaction
scale, we place upper limits on the string tension $G\mu$ below $10^{-8}$ in
some regions of the cosmic string parameter space.


title:
Topological Interference Management with Alternating Connectivity: The
  Wyner-Type Three User Interference Channel

abstract:
  Interference management in a three-user interference channel with alternating
connectivity with only topological knowledge at the transmitters is considered.
The network has a Wyner-type channel flavor, i.e., for each connectivity state
the receivers observe at most one interference signal in addition to their
desired signal. Degrees of freedom (DoF) upper bounds and lower bounds are
derived. The lower bounds are obtained from a scheme based on joint encoding
across the alternating states. Given a uniform distribution among the
connectivity states, it is shown that the channel has 2+ 1/9 DoF. This provides
an increase in the DoF as compared to encoding over each state separately,
which achieves 2 DoF only.


title:
Improved approximation algorithm for k-level UFL with penalties, a
  simplistic view on randomizing the scaling parameter

abstract:
  The state of the art in approximation algorithms for facility location
problems are complicated combinations of various techniques. In particular, the
currently best 1.488-approximation algorithm for the uncapacitated facility
location (UFL) problem by Shi Li is presented as a result of a non-trivial
randomization of a certain scaling parameter in the LP-rounding algorithm by
Chudak and Shmoys combined with a primal-dual algorithm of Jain et al. In this
paper we first give a simple interpretation of this randomization process in
terms of solving an aux- iliary (factor revealing) LP. Then, armed with this
simple view point, Abstract. we exercise the randomization on a more
complicated algorithm for the k-level version of the problem with penalties in
which the planner has the option to pay a penalty instead of connecting chosen
clients, which results in an improved approximation algorithm.


title: Approximability of Connected Factors

abstract:
  Finding a d-regular spanning subgraph (or d-factor) of a graph is easy by
Tutte's reduction to the matching problem. By the same reduction, it is easy to
find a minimal or maximal d-factor of a graph. However, if we require that the
d-factor is connected, these problems become NP-hard - finding a minimal
connected 2-factor is just the traveling salesman problem (TSP).
  Given a complete graph with edge weights that satisfy the triangle
inequality, we consider the problem of finding a minimal connected $d$-factor.
We give a 3-approximation for all $d$ and improve this to an
(r+1)-approximation for even d, where r is the approximation ratio of the TSP.
This yields a 2.5-approximation for even d. The same algorithm yields an
(r+1)-approximation for the directed version of the problem, where r is the
approximation ratio of the asymmetric TSP. We also show that none of these
minimization problems can be approximated better than the corresponding TSP.
  Finally, for the decision problem of deciding whether a given graph contains
a connected d-factor, we extend known hardness results.


title:
On the Gross-Pitaevskii equation with pumping and decay: stationary
  states and their stability

abstract:
  We investigate the behavior of solutions of the complex Gross-Pitaevskii
equation, a model that describes the dynamics of pumped decaying Bose-Einstein
condensates. The stationary radially symmetric solutions of the equation are
studied and their linear stability with respect to two-dimensional
perturbations is analyzed. Using numerical continuation, we calculate not only
the ground state of the system, but also a number of excited states. Accurate
numerical integration is employed to study the general nonlinear evolution of
the system from the unstable stationary solutions to the formation of stable
vortex patterns.


title: Double Blue Straggler sequences in GCs: the case of NGC 362

abstract:
  We used high-quality images acquired with the WFC3 on board the HST to probe
the blue straggler star (BSS) population of the Galactic globular cluster NGC
362. We have found two distinct sequences of BSS: this is the second case,
after M 30, where such a feature has been observed. Indeed the BSS location,
their extension in magnitude and color and their radial distribution within the
cluster nicely resemble those observed in M 30, thus suggesting that the same
interpretative scenario can be applied: the red BSS sub-population is generated
by mass transfer binaries, the blue one by collisions. The discovery of four
new W UMa stars, three of which lying along the red-BSS sequence, further
supports this scenario. We also found that the inner portion of the density
profile deviates from a King model and is well reproduced by either a mild
power-law (\alpha -0.2) or a double King profile. This feature supports the
hypothesis that the cluster is currently undergoing the core collapse phase.
Moreover, the BSS radial distribution shows a central peak and monotonically
decreases outward without any evidence of an external rising branch. This
evidence is a further indication of the advanced dynamical age of NGC 362: in
fact, together with M 30, NGC 362 belongs to the family of dynamically old
clusters (Family III) in the "dynamical clock" classification proposed by
Ferraro et al. (2012). The observational evidence presented here strengthens
the possible connection between the existence of a double BSS sequence and a
quite advanced dynamical status of the parent cluster.


title: On the density of nice Friedmans

abstract:
  A Friedman number is a positive integer which is the result of an expression
combining all of its own digits by use of the four basic operations,
exponentiation and digit concatenation. A "nice" Friedman number is a Friedman
number for which the expression constructing the number from its own digits can
be represented with the original order of the digits unchanged. One of the
fundamental questions regarding Friedman numbers, and particularly regarding
nice Friedman numbers, is how common they are among the integers. In this
paper, we prove that nice Friedman numbers have density 1, when considered in
binary, ternary or base four.


title:
Non-equilibrium structure and dynamics in a microscopic model of thin
  film active gels

abstract:
  In the presence of ATP, molecular motors generate active force dipoles that
drive suspensions of protein filaments far from thermodynamic equilibrium,
leading to exotic dynamics and pattern formation. Microscopic modelling can
help to quantify the relationship between individual motors plus filaments to
organisation and dynamics on molecular and supra-molecular length scales. Here
we present results of extensive numerical simulations of active gels where the
motors and filaments are confined between two infinite parallel plates. Thermal
fluctuations and excluded-volume interactions between filaments are included. A
systematic variation of rates for motor motion, attachment and detachment,
including a differential detachment rate from filament ends, reveals a range of
non-equilibrium behaviour. Strong motor binding produces structured filament
aggregates that we refer to as asters, bundles or layers, whose stability
depends on motor speed and differential end-detachment. The gross features of
the dependence of the observed structures on the motor rate and the filament
concentration can be captured by a simple one-filament model. Loosely bound
aggregates exhibit super-diffusive mass transport, where filament translocation
scales with lag time with non-unique exponents that depend on motor kinetics.
An empirical data collapse of filament speed as a function of motor speed and
end-detachment is found, suggesting a dimensional reduction of the relevant
parameter space. We conclude by discussing the perspectives of microscopic
modelling in the field of active gels.


title: Thermoelectric efficiency of critical quantum junctions

abstract:
  We derive the efficiency at maximal power of a scale-invariant (critical)
quantum junction in exact form. Both Fermi and Bose statistics are considered.
We show that time-reversal invariance is spontaneously broken. For fermions we
implement a new mechanism for efficiency enhancement above the Curzon-Ahlborn
bound, based on a shift of the particle energy in each heat reservoir,
proportional to its temperature. In this setting fermionic junctions can even
reach at maximal power the Carnot efficiency. The bosonic junctions at maximal
power turn out to be less efficient then the fermionic ones.

categories: cond-mat.stat-mech cond-mat.mes-hall math-ph math.MP quant-ph


title: A simple decoder for topological codes

abstract:
  Here we study an efficient algorithm for decoding the topological codes. It
is based on a simple principle, which should allow straightforward
generalization to complex decoding problems. It is benchmarked with the planar
code for both i.i.d. and spatially correlated errors and is found to compare
well with existing methods.


title:
Toward Calculations with Spectroscopic Accuracy: the 2s2.2p 2Po_{3/2} -
  2s2p2 4P_{5/2} Excitation Energy in Boron

abstract:
  No lines have been observed for transitions between the doublet and quartet
levels of B I. Consequently, energy levels based on observation for the latter
are obtained through extrapolation of wavelengths along the iso-electronic
sequence for the 2s2.2p 2Po_{3/2} - 2s2p2 4P_{5/2} transition. In this paper,
accurate theoretical excitation energies from a newly developed partitioned
correlation function interaction (PCFI) method are reported for B I that
include both relativistic effects in the Breit-Pauli approximation and a finite
mass correction. Results are compared with extrapolated values from observed
data. For B I our estimate of the excitation energy, 28959 +/- 5 cm^{-1}, is in
better agreement with the values obtained by Edl\'en et al. (1969) than those
reported by Kramida and Ryabtsev (2007). Our method is validated by applying
the same procedure to the separation of these levels in C II


title: Interchange reconnection between an active region and a corona hole

abstract:
  With the data from the Atmospheric Imaging Assembly (AIA) and the
Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory
(SDO), we present a magnetic interaction between an isolated coronal hole (CH)
and an emerging active region (AR). The AR emerged nearby the CH and interacted
with it. Bright loops constantly formed between them, which led to a continuous
retreat of the CH boundaries (CHBs). Meanwhile, two coronal dimmings
respectively appeared at the negative polarity of the AR and the east boundary
of the bright loops, and the AR was partly disturbed. Loop eruptions followed
by a flare occurred in the AR. The interaction was also accompanied by many
jets and an arc-shaped brightening that appeared to be observational signatures
of magnetic reconnection at the CHBs. By comparing the observations with the
derived coronal magnetic configuration, it is suggested that the interaction
between the CH and the AR excellently fitted in with the model of interchange
reconnection. It appears that our observations provide obvious evidences for
interchange reconnection.


title:
A necessary and sufficient condition for two relations to induce the
  same definable set family

abstract:
  In Pawlak rough sets, the structure of the definable set families is simple
and clear, but in generalizing rough sets, the structure of the definable set
families is a bit more complex. There has been much research work focusing on
this topic. However, as a fundamental issue in relation based rough sets, under
what condition two relations induce the same definable set family has not been
discussed. In this paper, based on the concept of the closure of relations, we
present a necessary and sufficient condition for two relations to induce the
same definable set family.


title: On Minty's theorem in the Heisenberg group

abstract:
  In this paper we extend some classical results of Convex Analysis to the
sub-Riemannian setting of the Heisenberg group. In particular, we provide a
horizontal version of Minty's theorem concerning maximal H-monotone operators
defined in the Heisenberg group with values in the first layer of its Lie
algebra.


title:
Stochastic stability of Lyapunov exponents and Oseledets splittings for
  semi-invertible matrix cocycles

abstract:
  We establish (i) stability of Lyapunov exponents and (ii) convergence in
probability of Oseledets spaces for semi-invertible matrix cocycles, subjected
to small random perturbations. The first part extends results of Ledrappier and
Young to the semi-invertible setting. The second part relies on the study of
evolution of subspaces in the Grassmannian.


title:
Existence of nontrivial solutions for asymptotically linear periodic
  Schr\"odinger equations

abstract:
  We study the Schr\"{o}dinger equation: \begin{equation} - \Delta
u+V(x)u=f(x,u) ,\qquad u\in H^{1}(\mathbb{R}^{N}),\nonumber \end{equation}
where $V$ is periodic and $f$ is periodic in the $x$-variables, 0 is in a gap
of the spectrum of the operator $-\Delta+V$ and $f$ is asymptotically linear as
$|u|\rightarrow+\infty.$ We prove that under some asymptotically linear
assumptions for $f$, this equation has a nontrivial solution. Our assumptions
for $f$ are different from the classical assumptions raised by G. B. Li and A.
Szulkin in


title:
HIFISTARS Herschel/HIFI observations of VY Canis Majoris. Molecular-line
  inventory of the envelope around the largest known star

abstract:
  To gain insight into the physical conditions and kinematics of the warm
(100-1000 K) gas around the red hyper-giant VY CMa, we performed sensitive high
spectral resolution observations of molecular lines in the sub-mm/FIR using the
HIFI instrument of the Herschel Space Observatory. We observed CO, H2O, and
other molecular species, sampling excitation energies from a few tens to a few
thousand K. These observations are part of the Herschel Guaranteed Time Key
Program HIFISTARS. We detected the J=6-5, J=10-9, and J=16-15 lines of 12CO and
13CO at about 100, 300, and 750K above the ground state (and the 13CO J=9-8
line). These lines are crucial for improving the modelling of the internal
layers of the envelope around VY CMa. We also detected 27 lines of H2O and its
isotopomers, and 96 lines of species such as NH3, SiO, SO, SO2 HCN, OH and
others, some of them originating from vibrationally excited levels. Three lines
were not unambiguously assigned. Our observations confirm that VY CMa's
envelope must consist of two or more detached components. The molecular
excitation in the outer layers is significantly lower than in the inner ones,
resulting in strong self-absorbed profiles in molecular lines that are
optically thick in this outer envelope, for instance, low-lying lines of H2O.
Except for the most abundant species, CO and H2O, most of the molecular
emission detected at these sub-mm/FIR wavelengths arise from the central parts
of the envelope. The spectrum of VY CMa is very prominent in vibrationally
excited lines, which are caused by the strong IR pumping present in the central
regions. Compared with envelopes of other massive evolved stars, VY CMa's
emission is particularly strong in these vibrationally excited lines, as well
as in the emission from less abundant species such as H13CN, SO, and NH3.


title: Understanding Color Confinement

abstract:
  Some aspects are discussed of the mechanism of color confinement in QCD by
condensation of magnetic monopoles in the vacuum.


title: Self-organized pattern formation in laser-induced multiphoton ionization

abstract:
  We use finite-difference time-domain modelling to investigate plasma
generation induced by multi-photon absorption of intense laser light in
dielectrics with tiny inhomogenities. Plasma generation is found to be strongly
amplified around nanometer-sized inhomogeneities as present in glasses. Each
inhomogeneity acts as the seed of a plasma structure growing against the
direction of light propagation. Plasma structures originating from randomly
distributed inhomogeneities are found to interact strongly and to organize in
regularly spaced planes oriented perpendicularly to the laser polarization. We
discuss similarities between our results and nanogratings in fused silica
written by laser beams with spatially homogeneous as well as radial and
azimuthal polarization.


title: Infinitely many algebras derived equivalent to a block

abstract:
  We give a construction that in many cases gives a simple way to construct
infinite families of algebras that are not Morita equivalent, but are all
derived equivalent to the same block algebra of a finite group, and apply it to
some small blocks. We make some remarks relating this construction to Donovan's
Conjecture and Broue's Abelian Defect Group Conjecture.


title: Weak backward error analysis for overdamped Langevin processes

abstract:
  We consider numerical approximations of overdamped Langevin stochastic
differential equations by implicit methods. We show a weak backward error
analysis result in the sense that the generator associated with the numerical
solution coincides with the solution of a modified Kolmogorov equation up to
high order terms with respect to the stepsize. This implies that every measure
of the numerical scheme is close to a modified invariant measure obtained by
asymptotic expansion. Moreover, we prove that, up to negligible terms, the
dynamic associated with the implicit scheme considered is exponentially mixing.


title:
Multi-channel parallel continuous variable quantum key distribution with
  Gaussian modulation

abstract:
  We propose a novel scheme for continuous variable quantum key
distribution(CV-QKD) using the subcarrier multiplexing technique which was
employed in microwave photonics. This scheme allows to distribute N channels
independent Gaussian modulated CV-QKD in parallel with one laser source and
several phase modulators. We analyze the influence of nonlinear signal mixing
and the security in the asymptotic limit. Results indicate that by using this
multiplexing technique, each channel will be introduced a non-Gaussian extra
source noise, resulting slightly short of the maximum transmission distance,
while the total secret key rate can be considerably increased. This scheme
could also be used for key distribution for multi-users and combined with the
WDM devices it has the potential to construct a CV-QKD network.


title:
Improved Collective Thomson Scattering measurements of fast ions at
  ASDEX Upgrade

abstract:
  Understanding the behaviour of the confined fast ions is important in both
current and future fusion experiments. These ions play a key role in heating
the plasma and will be crucial for achieving conditions for burning plasma in
next-step fusion devices. Microwave-based Collective Thomson Scattering (CTS)
is well suited for reactor conditions and offers such an opportunity by
providing measurements of the confined fast-ion distribution function resolved
in space, time and 1D velocity space. We currently operate a CTS system at
ASDEX Upgrade using a gyrotron which generates probing radiation at 105 GHz. A
new setup using two independent receiver systems has enabled improved
subtraction of the background signal, and hence the first accurate
characterization of fast-ion properties. Here we review this new dual-receiver
CTS setup and present results on fast-ion measurements based on the improved
background characterization. These results have been obtained both with and
without NBI heating, and with the measurement volume located close to the
centre of the plasma. The measurements agree quantitatively with predictions of
numerical simulations. Hence, CTS studies of fast-ion dynamics at ASDEX Upgrade
are now feasible. The new background subtraction technique could be important
for the design of CTS systems in other fusion experiments.


title:
An asymptotic expansion of the Casorati determinant and its application
  to discrete integrable systems

abstract:
  The Hankel determinant appears in the representation of solutions to several
integrable systems. Asymptotic expansion of the Hankel determinant thus plays a
key role for investigating asymptotic analysis of such integrable system. In
this paper, an asymptotic expansion formula of a certain Casorati determinant
is presented as an extension of the Hankel case. It is also shown that an
application of it to an asymptotic analysis of the discrete hungry
Lotka-Volterra system, which is one of basic models in mathematical biology.


title:
Improved Bayesian Logistic Supervised Topic Models with Data
  Augmentation

abstract:
  Supervised topic models with a logistic likelihood have two issues that
potentially limit their practical use: 1) response variables are usually
over-weighted by document word counts; and 2) existing variational inference
methods make strict mean-field assumptions. We address these issues by: 1)
introducing a regularization constant to better balance the two parts based on
an optimization formulation of Bayesian inference; and 2) developing a simple
Gibbs sampling algorithm by introducing auxiliary Polya-Gamma variables and
collapsing out Dirichlet variables. Our augment-and-collapse sampling algorithm
has analytical forms of each conditional distribution without making any
restricting assumptions and can be easily parallelized. Empirical results
demonstrate significant improvements on prediction performance and time
efficiency.


title: Discriminative Relational Topic Models

abstract:
  Many scientific and engineering fields involve analyzing network data. For
document networks, relational topic models (RTMs) provide a probabilistic
generative process to describe both the link structure and document contents,
and they have shown promise on predicting network structures and discovering
latent topic representations. However, existing RTMs have limitations in both
the restricted model expressiveness and incapability of dealing with imbalanced
network data. To expand the scope and improve the inference accuracy of RTMs,
this paper presents three extensions: 1) unlike the common link likelihood with
a diagonal weight matrix that allows the-same-topic interactions only, we
generalize it to use a full weight matrix that captures all pairwise topic
interactions and is applicable to asymmetric networks; 2) instead of doing
standard Bayesian inference, we perform regularized Bayesian inference
(RegBayes) with a regularization parameter to deal with the imbalanced link
structure issue in common real networks and improve the discriminative ability
of learned latent representations; and 3) instead of doing variational
approximation with strict mean-field assumptions, we present collapsed Gibbs
sampling algorithms for the generalized relational topic models by exploring
data augmentation without making restricting assumptions. Under the generic
RegBayes framework, we carefully investigate two popular discriminative loss
functions, namely, the logistic log-loss and the max-margin hinge loss.
Experimental results on several real network datasets demonstrate the
significance of these extensions on improving the prediction performance, and
the time efficiency can be dramatically improved with a simple fast
approximation method.


title:
Sparse signal recovery by $\ell_q$ minimization under restricted
  isometry property

abstract:
  In the context of compressed sensing, the nonconvex $\ell_q$ minimization
with $0<q<1$ has been studied in recent years. In this paper, by generalizing
the sharp bound for $\ell_1$ minimization of Cai and Zhang, we show that the
condition $\delta_{(s^q+1)k}<\dfrac{1}{\sqrt{s^{q-2}+1}}$ in terms of
\emph{restricted isometry constant (RIC)} can guarantee the exact recovery of
$k$-sparse signals in noiseless case and the stable recovery of approximately
$k$-sparse signals in noisy case by $\ell_q$ minimization. This result is more
general than the sharp bound for $\ell_1$ minimization when the order of RIC is
greater than $2k$ and illustrates the fact that a better approximation to
$\ell_0$ minimization is provided by $\ell_q$ minimization than that provided
by $\ell_1$ minimization.


title:
The pristine atomic structure of MoS2 monolayer protected from electron
  radiation damage by graphene

abstract:
  Materials can, in principle, be imaged at the level of individual atoms with
aberration corrected transmission electron microscopy. However, such resolution
can be attained only with very high electron doses. Consequently, radiation
damage is often the limiting factor when characterizing sensitive materials.
Here, we demonstrate a simple and effective method to increase the electron
radiation tolerance of materials by using graphene as protective coating. This
leads to an improvement of three orders of magnitude in the radiation tolerance
of monolayer MoS2. Further on, we construct samples in different
heterostructure configurations to separate the contributions of different
radiation damage mechanisms.


title: Miras or SRA'S - the Transient Type Variables

abstract:
  The group of Mira-type and semi-regular variables with similar periodicity
(multiperiodicty) is analyzed. They have periods of 230-260 days and 140-150
days and show intervals of periodical (Mira-type) variability with relatively
high amplitude and "semi-regular" (SR-type) small-amplitude oscillations.
Results of periodogram analysis are represented.


title: Towards understanding thermal jet quenching via lattice simulations

abstract:
  After reviewing how simulations employing classical lattice gauge theory
permit to test a conjectured Euclideanization property of a light-cone Wilson
loop in a thermal non-Abelian plasma, we show how Euclidean data can in turn be
used to estimate the transverse collision kernel, C(k_perp), characterizing the
broadening of a high-energy jet. First results, based on data produced recently
by Panero et al, suggest that C(k_perp) is enhanced over the known NLO result
in a soft regime k_perp < a few T. The shape of k_perp^3 C(k_perp) is
consistent with a Gaussian at small k_perp.


title: A New 1.4GHz Radio Continuum Map of the Sky South of Declination +25 deg

abstract:
  Archival data from the HI Parkes All-Sky Survey (HIPASS) and the HI Zone of
Avoidance (HIZOA) survey have been carefully reprocessed into a new 1.4GHz
continuum map of the sky south of declination +25 deg. The wide sky coverage,
high sensitivity of 40mK (limited by confusion), resolution of 14'.4 (compared
to 51' for the Haslam et al. 408MHz and 35' for the Reich et al. 1.4GHz
surveys), and low level of artefacts makes this map ideal for numerous studies,
including: merging into interferometer maps to complete large-scale structures;
decomposition of thermal and non-thermal emission components from Galactic and
extragalactic sources; and comparison of emission regions with other
frequencies. The new map is available for download.


title:
Dynamics of Natural Killer cell receptor revealed by quantitative
  analysis of photoswitchable protein

abstract:
  Natural Killer (NK) cell activation is dynamically regulated by numerous
activating and inhibitory surface receptors that accumulate at the immune
synapse. Quantitative analysis of receptor dynamics has been limited by
methodologies which rely on indirect measurements such as fluorescence recovery
after photobleaching. Here, we report a novel approach to study how proteins
traffic to and from the immune synapse using NK cell receptors tagged with the
photoswitchable fluorescent protein tdEosFP, which can be irreversibly
photoswitched from a green to red fluorescent state by ultraviolet light. Thus,
following a localized switching event, the movement of the photoswitched
molecules can be temporally and spatially resolved by monitoring fluorescence
in two regions of interest. By comparing images with mathematical models, we
evaluated the diffusion coefficient of the receptor KIR2DL1 (0.23 +- 0.06
micron^2/s) and assessed how synapse formation affects receptor dynamics. Our
data conclude that the inhibitory NK cell receptor KIR2DL1 is continually
trafficked into the synapse and remains surprisingly stable there. Unexpectedly
however, in NK cells forming synapses with multiple target cells
simultaneously, KIR2DL1 at one synapse can relocate to another synapse. Thus,
our results reveal a previously undetected inter-synaptic exchange of protein.


title: Strong divisibility and lcm-sequences

abstract:
  Let $R$ be a gcd-domain (for example let $R$ be a unique factorization
domain), and let $(a_n)_{n\geqslant1}$ be a sequence of nonzero elements in
$R$. We prove that $\gcd(a_n,a_m)=a_{\gcd(n,m)}$ for all $n,m\geqslant1$ if and
only if $$a_n=\prod\limits_{d\mid n} c_d\quad\mbox{for} \ n\geqslant1, $$ where
$c_1=a_1$ and
$c_n=\mbox{lcm}(a_1,a_2,\dots,a_n)/\mbox{lcm}(a_1,a_2,\dots,a_{n-1})$ for
$n\geqslant2$. All equalities with gcd and lcm are determined up to units of
$R$.


title:
Measurement of negatively charged pion spectra in inelastic p+p
  interactions at $p_{lab}$ = 20, 31, 40, 80 and 158 GeV/c

abstract:
  We present experimental results on inclusive spectra and mean multiplicities
of negatively charged pions produced in inelastic p+p interactions at incident
projectile momenta of 20, 31, 40, 80 and 158 GeV/c ($\sqrt{s} = $ 6.3, 7.7,
8.8, 12.3 and 17.3 GeV, respectively). The measurements were performed using
the large acceptance NA61/SHINE hadron spectrometer at the CERN Super Proton
Synchrotron.
  Two-dimensional spectra are determined in terms of rapidity and transverse
momentum. Their properties such as the width of rapidity distributions and the
inverse slope parameter of transverse mass spectra are extracted and their
collision energy dependences are presented. The results on inelastic p+p
interactions are compared with the corresponding data on central Pb+Pb
collisions measured by the NA49 experiment at the CERN SPS.
  The results presented in this paper are part of the NA61/SHINE ion program
devoted to the study of the properties of the onset of deconfinement and search
for the critical point of strongly interacting matter. They are required for
interpretation of results on nucleus-nucleus and proton-nucleus collisions.


title: Linear Algorithm for Digital Euclidean Connected Skeleton

abstract:
  The skeleton is an essential shape characteristic providing a compact
representation of the studied shape. Its computation on the image grid raises
many issues. Due to the effects of discretization, the required properties of
the skeleton - thinness, homotopy to the shape, reversibility, connectivity -
may become incompatible. However, as regards practical use, the choice of a
specific skeletonization algorithm depends on the application. This allows to
classify the desired properties by order of importance, and tend towards the
most critical ones. Our goal is to make a skeleton dedicated to shape matching
for recognition. So, the discrete skeleton has to be thin - so that it can be
represented by a graph -, robust to noise, reversible - so that the initial
shape can be fully reconstructed - and homotopic to the shape. We propose a
linear-time skeletonization algorithm based on the squared Euclidean distance
map from which we extract the maximal balls and ridges. After a thinning and
pruning process, we obtain the skeleton. The proposed method is finally
compared to fairly recent methods.


title: Fast radio bursts may originate from nearby flaring stars

abstract:
  Six cases of fast radio bursts (FRBs) have recently been discovered. The FRBs
are bright (~0.1 - 1 Jy) and brief (~ 1 ms) pulses of radio emission with
dispersion measures (DMs) that exceed Galactic values, and hence FRBs have been
interpreted to be at cosmological distances. We propose, instead, that FRBs are
rare eruptions of flaring main-sequence stars within ~1 kpc. Rather than
associating their excess DM with the intergalactic medium, we relate it to a
blanket of coronal plasma around their host stars. We have monitored at optical
bands the stars within the radio beams of three of the known FRBs. In one
field, we find a bright (V=13.6 mag) variable star (0.2 mag peak-to-trough)
with a main-sequence G-type spectrum and a period P = 7.8 hr, likely a
W-UMa-type contact binary. Analysis of our data outside of the FRB beams
indicates a 5% chance probability of finding a variable star of this brightness
and amplitude within the FRB beams. We find no unusual variable stars in the
other two FRB fields. Further observations are needed to investigate if similar
nearby (<~ 800 pc) stars are the sources of FRBs.


title: Strong Band Hybridization between Silicene and Ag(111)Substrate

abstract:
  By using first-principles calculations, we systematically investigated
several observed phases of silicene on Ag(111) substrates and their electronic
structures. We find that the original Dirac cone of silicene is about 1.5-1.7
eV deeply below the Fermi level and severely destroyed by the band
hybridization between silicene and Ag in all the examined phases. Thus,
silicene synthesized on Ag(111) substrates could not preserve its excellent
electronic property and new method is needed to develop in synthesizing
silicene with its Dirac cone surviving.


title:
Coupling of single quantum emitters to plasmons propagating on
  mechanically etched wires

abstract:
  We demonstrate the coupling of a single nitrogen vacancy center in a
nanodiamond to propagating plasmonic modes of mechanically etched silver
nanowires. The mechanical etch is performed on single crystalline silver
nanoplates by the tip of an atomic force microscope cantilever to produce wires
with pre-designed lengths. We show that single plasmon propgation can be
obtained in these wires, thus making these structures a platform for quantum
information processing.


title:
Analysis of the X(3872), Z_c(3900) and Z_c(3885) as axial-vector
  tetraquark states with QCD sum rules

abstract:
  In this article, we distinguish the charge conjunctions of the interpolating
currents, calculate the contributions of the vacuum condensates up to
dimension-10 in a consistent way in the operator product expansion, study the
masses and pole residues of the $J^{PC}=1^{+\pm}$ hidden charmed tetraquark
states with the QCD sum rules, and explore the energy scale dependence in
details for the first time. The predictions
$M_{X}=3.87^{+0.09}_{-0.09}\,\rm{GeV}$ and
$M_{Z}=3.91^{+0.11}_{-0.09}\,\rm{GeV}$ support assigning the $X(3872)$ and
$Z_c(3900)$ (or $Z_c(3885)$) as the $1^{++}$ and $1^{+-}$ diquark-antidiquark
type tetraquark states, respectively.


title: Cohomology associated to a Poisson structure on Weil bundles

abstract:
  Let M be a paracompact smooth manifold of dimension n; A a Weil algebra and
M^A the Weil bundle associated. We define and describe the notion of
\widetilded-Poisson cohomology and of \widetilded^A -Poisson cohomology on M^A.


title: Generalized constructive tree weights

abstract:
  The Loop Vertex Expansion (LVE) is a quantum field theory (QFT) method which
explicitly computes the Borel sum of Feynman perturbation series. This LVE
relies in a crucial way on symmetric tree weights which define a measure on the
set of spanning trees of any connected graph. In this paper we generalize this
method by defining new tree weights. They depend on the choice of a partition
of a set of vertices of the graph, and when the partition is non-trivial, they
are no longer symmetric under permutation of vertices. Nevertheless we prove
they have the required positivity property to lead to a convergent LVE; in
fact, we formulate this positivity property precisely for the first time. Our
generalized tree weights are inspired by the Brydges-Battle-Federbush work on
cluster expansions and could be particularly suited to the computation of
connected functions in QFT. Several concrete examples are explicitly given.