title: Fake View Analytics in Online Video Services

abstract:
  Online video-on-demand(VoD) services invariably maintain a view count for
each video they serve, and it has become an important currency for various
stakeholders, from viewers, to content owners, advertizers, and the online
service providers themselves. There is often significant financial incentive to
use a robot (or a botnet) to artificially create fake views. How can we detect
the fake views? Can we detect them (and stop them) using online algorithms as
they occur? What is the extent of fake views with current VoD service
providers? These are the questions we study in the paper. We develop some
algorithms and show that they are quite effective for this problem.


title:
First-principles simulation of the optical response of bulk and
  thin-film \alpha-quartz irradiated with an ultrashort intense laser pulse

abstract:
  A computational method based on a first-principles multiscale simulation has
been used for calculating the optical response and the ablation threshold of an
optical material irradiated with an ultrashort intense laser pulse. The method
employs Maxwell's equations to describe laser pulse propagation and
time-dependent density functional theory to describe the generation of
conduction band electrons in an optical medium. Optical properties, such as
reflectance and absorption, were investigated for laser intensities in the
range $10^{10} \, \mathrm{W/cm^{2}}$ to $2 \times 10^{15} \, \mathrm{W/cm^{2}}$
based on the theory of generation and spatial distribution of the conduction
band electrons. The method was applied to investigate the changes in the
optical reflectance of $\alpha$-quartz bulk, half-wavelength thin-film and
quarter-wavelength thin-film and to estimate their ablation thresholds. Despite
the adiabatic local density approximation used in calculating the
exchange--correlation potential, the reflectance and the ablation threshold
obtained from our method agree well with the previous theoretical and
experimental results. The method can be applied to estimate the ablation
thresholds for optical materials in general. The ablation threshold data can be
used to design ultra-broadband high-damage-threshold coating structures.


title: Some non monotone schemes for Hamilton-Jacobi-Bellman equations

abstract:
  We extend the theory of Barles Jakobsen to develop numerical schemes for
Hamilton Jacobi Bellman equations. We show that the monotonicity of the schemes
can be relaxed still leading to the convergence to the viscosity solution of
the equation. We give some examples of such numerical schemes and show that the
bounds obtained by the framework developed are not tight. At last we test some
numerical schemes.


title:
Local orbit types of the isotropy representations for semisimple
  pseudo-Riemannian symmetric spaces

abstract:
  We list up all the possible local orbit types of hyperbolic or elliptic
orbits for the isotropy representations of semisimple pseudo-Riemannian
symmetric spaces. It is key to give a recipe to determine the local orbit types
of hyperbolic principal orbits by using three kind of restricted root systems
and Satake diagrams associated with semisimple pseudo-Riemannian symmetric
spaces.


title: Bayesian Geoadditive Expectile Regression

abstract:
  Regression classes modeling more than the mean of the response have found a
lot of attention in the last years. Expectile regression is a special and
computationally convenient case of this family of models. Expectiles offer a
quantile-like characterisation of a complete distribution and include the mean
as a special case. In the frequentist framework the impact of a lot of
covariates with very different structures have been made possible. We propose
Bayesian expectile regression based on the asymmetric normal distribution. This
renders possible incorporating for example linear, nonlinear, spatial and
random effects in one model. Furthermore a detailed inference on the estimated
parameters can be conducted. Proposal densities based on iterativly weighted
least squares updates for the resulting Markov chain Monte Carlo (MCMC)
simulation algorithm are proposed and the potential of the approach for
extending the flexibility of expectile regression towards complex
semiparametric regression specifications is discussed.


title: Lazarsfeld-Mukai bundles and applications. II

abstract:
  This paper is a continuation of arXiv:1205.4415. We focus on non-K3 surfaces
providing some improvements of known results.


title: Heating and Dynamics of Two Flare Loop Systems Observed by AIA and EIS

abstract:
  We investigate heating and evolution of flare loops in a C4.7 two-ribbon
flare on 2011 February 13. From SDO/AIA imaging observations, we can identify
two sets of loops. Hinode/EIS spectroscopic observations reveal blueshifts at
the feet of both sets of loops. The evolution and dynamics of the two sets are
quite different. The first set of loops exhibits blueshifts for about 25
minutes followed by redshifts, while the second set shows stronger blueshifts,
which are maintained for about one hour. The UV 1600 observation by AIA also
shows that the feet of the second set of loops brighten twice. These suggest
that continuous heating may be present in the second set of loops. We use
spatially resolved UV light curves to infer heating rates in the few tens of
individual loops comprising the two loop systems. With these heating rates, we
then compute plasma evolution in these loops with the "enthalpy-based thermal
evolution of loops" (EBTEL) model. The results show that, for the first set of
loops, the synthetic EUV light curves from the model compare favorably with the
observed light curves in six AIA channels and eight EIS spectral lines, and the
computed mean enthalpy flow velocities also agree with the Doppler shift
measurements by EIS. For the second set of loops modeled with twice-heating,
there are some discrepancies between modeled and observed EUV light curves in
low-temperature bands, and the model does not fully produce the prolonged
blueshift signatures as observed. We discuss possible causes for the
discrepancies.


title:
Urban Landscape is an Important Factor in Rising Inequality, Spatial
  Segregation, and Social Isolation

abstract:
  Urbanization has been the dominant demographic trend in the entire world,
during the last half century. Rural to urban migration, international
migration, and the re-classification or expansion of existing city boundaries
have been among the major reasons for increasing urban population. The
essentially fast growth of cities in the last decades urgently calls for a
profound insight into the common principles stirring the structure of urban
developments all over the world. We have discussed the graph representations of
urban spatial structures and suggested a computationally simple technique that
can be used in order to spot the relatively isolated locations and
neighborhoods, to detect urban sprawl, and to illuminate the hidden community
structures in complex urban textures. The approach may be implemented for the
detailed expertise of any urban pattern and the associated transport networks
that may include many transportation modes.


title:
A Platform for Teaching Applied Distributed Software Development: The
  Ongoing Journey of the Helsinki Software Factory

abstract:
  Teaching distributed software development (DSD) in project courses where
student teams are geographically distributed promises several benefits. One
main benefit is that in contrast to traditional classroom courses, students can
experience the effects of distribution and the mechanisms for coping with
distribution by themselves, therefore understanding their relevance for
software development. They can thus learn to take more care of distribution
challenges and risks when starting to develop software in industry. However,
providing a sustainable environment for such project courses is difficult. A
development environment is needed that can connect to different distributed
teams and an ongoing routine to conduct such courses needs to be established.
This article sketches a picture of the Software Factory, a platform that
supports teaching distributed student projects and that has now been
operational for more than three years. We describe the basic steps of
conducting Software Factory projects, and portray experiences from past factory
projects. In addition, we provide a short overview of related approaches and
future activities.


title: A taste of nonstandard methods in combinatorics of numbers

abstract:
  By presenting the proofs of a few sample results, we introduce the reader to
the use of nonstandard analysis in aspects of combinatorics of numbers.


title: Long-range spin transfer in triple quantum dots

abstract:
  Tunneling in a quantum coherent structure is not restricted to only nearest
neighbours. Hopping between distant sites is possible via the virtual
occupation of otherwise avoided intermediate states. Here we report the
observation of long range transitions in the transport through three quantum
dots coupled in series. A single electron is delocalized between the left and
right quantum dots while the centre one remains always empty. Superpositions
are formed and both charge and spin are exchanged between the outermost dots.
Detection of the process is achieved via the observation of narrow resonances,
insensitive to the transport Pauli spin blockade.


title: Teaching Software Process Modeling

abstract:
  Most university curricula consider software processes to be on the fringes of
software engineering (SE). Students are told there exists a plethora of
software processes ranging from RUP over V-shaped processes to agile methods.
Furthermore, the usual students' programming tasks are of a size that either
one student or a small group of students can manage the work. Comprehensive
processes being essential for large companies in terms of reflecting the
organization structure, coordinating teams, or interfaces to business processes
such as contracting or sales, are complex and hard to teach in a lecture, and,
therefore, often out of scope. We experienced tutorials on using Java or C#, or
on developing applications for the iPhone to gather more attention by students,
simply speaking, as these are more fun for them. So, why should students spend
their time in software processes? From our experiences and the discussions with
a variety of industrial partners, we learned that students often face trouble
when taking their first "real" jobs, even if the company is organized in a lean
or agile shape. Therefore, we propose to include software processes more
explicitly into the SE curricula. We designed and implemented a course at
Master's level in which students learn why software processes are necessary,
and how they can be analyzed, designed, implemented, and continuously improved.
In this paper, we present our course's structure, its goals, and corresponding
teaching methods. We evaluate the course and further discuss our experiences so
that lecturers and researchers can directly use our lessons learned in their
own curricula.


title:
Dispersive line shape in the vicinity of the {\nu} = 1 quantum Hall
  state: Coexistence of Knight shifted and unshifted resistively detected NMR
  responses

abstract:
  The frequency splitting between the dip and the peak of the resistively
detected nuclear magnetic resonance (RDNMR) dispersive line shape (DLS) has
been measured in the quantum Hall effect regime as a function of filling
factor, carrier density and nuclear isotope. The splitting increases as the
filling factor tends to {\nu} = 1 and is proportional to the hyperfine
coupling, similar to the usual Knight shift versus {\nu}-dependence. The peak
frequency shifts linearly with magnetic field throughout the studied filling
factor range and matches the unshifted substrate signal, detected by classical
NMR. Thus, the evolution of the splitting is entirely due to the changing
Knight shift of the dip feature. The nuclear spin relaxation time, T1, is
extremely long (hours) at precisely the peak frequency. These results are
consistent with the local formation of a {\nu} = 2 phase due to the existence
of spin singlet D$^-$ complexes.


title:
The effective potential of the confinement order parameter in the
  Hamiltonian Approach

abstract:
  The effective potential of the order parameter for confinement is calculated
within the variational approach to the Hamilton formulation of Yang-Mills
theory. Compactifying one spatial dimension and using a background gauge fixing
this potential is obtained by minimizing the energy density for a given
constant and color diagonal background field directed along the compactified
dimension. Using Gaussian type trial wave functionals I establish an analytic
relation between the propagators in the background gauge at finite temperature
and the corresponding zero temperature propagators in Coulomb gauge. In the
simplest truncation, neglecting the ghost and using the ultraviolet form of the
gluon energy one recovers the Weiss potential. On the other hand from the
infrared form of the gluon energy one finds an effective potential which yields
a vanishing Polyakov loop indicating the confined phase. From the full
non-perturbative potential (with the ghost included) one extracts a critical
temperature of the deconfinement phase transition of 269 MeV for the gauge
group SU(2) and 283 MeV for SU(3).


title: Frequency Multiplexing for Readout of Spin Qubits

abstract:
  We demonstrate a low loss, chip-level frequency multiplexing scheme for
readout of scaled-up spin qubit devices. By integrating separate bias tees and
resonator circuits on-chip for each readout channel, we realize dispersive
gate-sensing in combination with charge detection based on two rf quantum point
contacts (rf-QPCs). We apply this approach to perform multiplexed readout of a
double quantum dot in the few-electron regime, and further demonstrate
operation of a 10-channel multiplexing device. Limitations for scaling spin
qubit readout to large numbers of multiplexed channels is discussed.


title:
Rotational Tunneling States and the Non-Debye Specific Heat of Dipolar
  Glasses

abstract:
  Specific heat of dipolar glasses does not obey Debye law. It is of interest
to know if the non-Debye specific heat can be accounted for in terms of
Schottky-type specific heat arising from rotational tunneling states of the
dipoles. This paper deals with rotational tunneling spectra of NH$_{4}^{+}$
ions and the non-Debye specific heat of mixed salts (e.g.
(NH$_{4})_{x}$Rb$_{1-x}$Br) of ammonium and alkali halides which are known to
exhibit dipolar glass phase. We have measured specific heat of above mixed
salts at low temperatures (1.5 K $< T <$ 15 K). It is seen that while the
specific heat of pure salts obeys Debye law, the specific heat of mixed salts
does not obey Debye law. We have studied the effect of the NH$_{4}^{+}$ ion
concentration, first neighbor environment of NH$_{4}^{+}$ ion and the lattice
strain field on the non-Debye specific heat by carrying out measurements on
suitably chosen mixed salts. Independent of above, we have measured the
rotational tunneling spectra, $f(\omega $), of the NH$_{4}^{+}$ ions in above
salts using technique of neutron incoherent inelastic scattering. The above
studies show that both the non-Debye specific heat and the tunneling spectra of
the NH$_{4}^{+}$ ions depend on the NH$_{4}^{+}$ ion concentration, first
neighbor environment of NH$_{4}^{+}$ ions and the lattice strain field. We have
further shown that the temperature dependence of the measured specific heat can
be explained for all the samples in terms of a model that takes account of
contributions to the specific heat from the Debye phonons and the rotational
tunneling states of the NH$_{4}^{+}$ ions. To the best of our knowledge, this
is a first study where it is shown that measured specific heat of
(NH$_{4})_{x}$Rb$_{1-x}$Br can be quantitatively explained in terms of an
experimentally measured rotational tunneling spectra $f(\omega $) of the
NH$_{4}^{+}$ ions.


title: Functional Bipartite Ranking: a Wavelet-Based Filtering Approach

abstract:
  It is the main goal of this article to address the bipartite ranking issue
from the perspective of functional data analysis (FDA). Given a training set of
independent realizations of a (possibly sampled) second-order random function
with a (locally) smooth autocorrelation structure and to which a binary label
is randomly assigned, the objective is to learn a scoring function s with
optimal ROC curve. Based on linear/nonlinear wavelet-based approximations, it
is shown how to select compact finite dimensional representations of the input
curves adaptively, in order to build accurate ranking rules, using recent
advances in the ranking problem for multivariate data with binary feedback.
Beyond theoretical considerations, the performance of the learning methods for
functional bipartite ranking proposed in this paper are illustrated by
numerical experiments.


title: Rainbow path and color degree in edge colored graphs

abstract:
  Let $G$ be an edge colored graph. A {\it}{rainbow path} in $G$ is a path in
which all the edges are colored with distinct colors. Let $d^c(v)$ be the color
degree of a vertex $v$ in $G$, i.e. the number of distinct colors present on
the edges incident on the vertex $v$. Let $t$ be the maximum length of a
rainbow path in $G$. Chen and Li showed that if $d^c \geq k$, for every vertex
$v$ of $G$, then $t \geq \left \lceil \frac{3 k}{5}\right \rceil + 1$ (Long
heterochromatic paths in edge-colored graphs, The Electronic Journal of
Combinatorics 12 (2005), # R33, Pages:1-33.) Unfortunately, proof by Chen and
Li is very long and comes to about 23 pages in the journal version. Chen and Li
states in their paper that it was conjectured by Akira Saito, that $t \ge \left
\lceil \frac {2k} {3} \right \rceil$. They also states in their paper that they
believe $t \ge k - c$ for some constant $c$.
  In this note, we give a short proof to show that $t \ge \left \lceil \frac{3
k}{5}\right \rceil$, using an entirely different method. Our proof is only
about 2 pages long. The draw-back is that our bound is less by 1, than the
bound given by Chen and Li. We hope that the new approach adopted in this paper
would eventually lead to the settlement of the conjectures by Saito and/or Chen
and Li.


title:
Observation of Anticorrelation with Classical Light in a Linear Optical
  System

abstract:
  Two-photon anticorrelation is observed when laser and pseudothermal light
beams are incident to the two input ports of a Hong-Ou-Mandel interferometer,
respectively. The spatial second-order interference pattern of laser and
pseudothermal light beams is reported. Temporal Hong-Ou-Mandel dip is also
observed when these two detectors are at the symmetrical positions. These
results are helpful to understand the physics behind the second-order
interference of light.


title: Current signatures and search for Pop. III stars in the Local Universe

abstract:
  Recent numerical studies argue that low-mass stars can be formed even at
zero-metallicity environment. These low-mass Population III(Pop.~III) stars are
thought to be still shining and able to be observed in the Local Universe. Most
low-mass Pop.~III stars are thought to be formed as secondary companions in
binary systems. They can be escaped from their host mini-halos when their
primary companions explode as supernovae. In this paper, we estimate the escape
probability of the low-mass Pop.~III stars from their host mini-halos. We find
that $\sim 100$ Pop.~III stars are expected. We also compute spatial
distribution of these escaped Pop.~III survivors by means of the semi-analytic
hierarchical chemical evolution model. Typically, they are distributed around
$\sim 2$Mpc away from the Milky Way but 5 -- $35\%$ of the escaped stars fall
into the Milky Way halo. These escaped Pop.~III stars are possibly detected by
very large scaled surveys being planned.


title: The magnetic susceptibility in QCD

abstract:
  Recently much work has been devoted to the study of QCD coupled to a
background magnetic field. Strongly interacting matter acts as a magnetic
medium and it is natural to study the properties of this medium, in particular
to understand if it behaves like a diamagnetic or a paramagnetic material. A
serious difficulty in studying these properties by means of LQCD simulations is
the quantization of the magnetic field in a toroidal geometry. We will expose a
method to overcome this difficulty and we will present data obtained for the
$N_f=2$ theory that show that the QCD medium is paramagnetic.


title: Quantum speed limit for arbitrary initial states

abstract:
  We investigate the generic bound on the minimal evolution time of the open
dynamical quantum system. This quantum speed limit time is applicable to both
mixed and pure initial states. We then apply this result to the damped
Jaynes-Cummings model and the Ohimc-like dephasing model starting from a
general time-evolution state. The bound of this time-dependent state at any
point in time can be found. For the damped Jaynes-Cummings model, the
corresponding bound first decreases and then increases in the Markovian
dynamics. While in the non-Markovian regime, the speed limit time shows an
interesting periodic oscillatory behavior. For the case of Ohimc-like dephasing
model, this bound would be gradually trapped to a fixed value. In addition, the
roles of the relativistic effects on the speed limit time for the observer in
non-inertial frames are discussed.


title:
Trading Permutation Invariance for Communication in Multi-Party
  Non-Locality Distillation

abstract:
  Quantum theory puts forward phenomena unexplainable by classical physics - or
information, for that matter. A prominent example is non-locality. Non-local
correlations cannot be explained, in classical terms, by shared information but
only by communication. On the other hand, the phenomenon does not allow for
(potentially faster-than-light) message transmission. The fact that some
non-local and non-signaling correlations are predicted by quantum theory,
whereas others fail to be, asks for a criterion, as simple as possible, that
characterizes which joint input-output behaviors are ``quantum'' and which are
not. In the context of the derivation of such criteria, it is of central
importance to understand when non-local correlations can be amplified by a
non-interactive protocol, i.e., whether some types of weak non-locality can be
distilled into stronger by local operations. Since it has been recognized that
the searched-for criteria must inherently be multi-partite, the question of
distillation, extensively studied and understood two-party scenarios, should be
adressed in the multi-user setting, where much less is known. Considering the
space of intrinsically n-partite correlations, we show the possibility of
distilling weak non-local boxes to the algebraically maximal ones without any
communication. Our protocols improve on previously known methods which still
required partial communication. The price we have to pay for dropping the need
for communication entirely is the assumption of permutation invariance: Any
correlation that can be realized between some set of players is possible
between any such set. This assumption is very natural since the laws of physics
are invariant under spacial translation.


title:
Extrapolating the term structure of interest rates with parameter
  uncertainty

abstract:
  Pricing extremely long-dated liabilities market consistently deals with the
decline in liquidity of financial instruments on long maturities. The aim is to
quantify the uncertainty of rates up to maturities of a century. We assume that
the interest rates follow the affine mean-reverting Vasicek model. We model
parameter uncertainty by Bayesian distributions over the parameters. The
cross-sectional and time series parameters are obtained via the restricted
bivariate VAR(1) model. The empirical example shows extremely low confidence in
long term extrapolations due to the accumulated effect of the mean-reversion`s
behaviour close to the unit root.


title: Strong forms of linearization for Hopf monoids in species

abstract:
  A vector species is a functor from the category of finite sets with
bijections to vector spaces; informally, one can view this as a sequence of
$S_n$-modules. A Hopf monoid (in the category of vector species) consists of a
vector species with unit, counit, product, and coproduct morphisms satisfying
several compatibility conditions, analogous to a graded Hopf algebra. We say
that a Hopf monoid is strongly linearized if it has a "basis" preserved by its
product and coproduct in a certain sense. We prove several equivalent
characterizations of this property, and show that any strongly linearized Hopf
monoid which is commutative and cocommutative possesses four bases which one
can view as analogues of the classical bases of the algebra of symmetric
functions. There are natural functors which turn Hopf monoids into graded Hopf
algebras, and applying these functors to strongly linearized Hopf monoids
produces several notable families of Hopf algebras. For example, in this way we
give a simple unified construction of the Hopf algebras of superclass functions
attached to the maximal unipotent subgroups of three families of classical
Chevalley groups.


title:
Derivation of breakup probabilities from experimental elastic
  backscattering data

abstract:
  We suggest simple and useful method to extract breakup probabilities from the
experimental elastic backscattering probabilities in the reactions with toughly
and weakly bound nuclei.


title: Natural seesaw realization at the TeV scale

abstract:
  We summarize the phenomenological constraints on seesaw scenarios defined at
the TeV scale and provide a simple extension of the Standard Model which
naturally leads to a testable mechanism of neutrino mass generation.


title: A Gauss-Bonnet formula for moduli spaces of Riemann surfaces

abstract:
  We prove a Gauss-Bonnet theorem for (finite coverings of) moduli spaces of
Riemann surfaces endowed with the McMullen metric. The proof uses properties of
an exhaustion of moduli spaces by compact submanifolds with corners and the
Gauss-Bonnet formula of Allendoerfer and Weil for Riemannian polyhedra.


title:
Extremal densities and measures on groups and $G$-spaces and their
  combinatorial applications

abstract:
  This text contains lecture notes of the course taught to Ph.D. students of
Jagiellonian University in Krakow on 25-28 November, 2013.


title:
The behavior of transverse waves in nonuniform solar flux tubes. II.
  Implications for coronal loop seismology

abstract:
  Seismology of coronal loops using observations of damped transverse
oscillations in combination with results from theoretical models is a tool to
indirectly infer physical parameters in the solar atmospheric plasma. Existing
seismology schemes based on approximations to the period and damping time of
kink oscillations are often used beyond their theoretical range of
applicability. These approximations assume that the variation of density across
the loop is confined to a nonuniform layer much thinner than the radius of the
loop, but the results of the inversion problem often do not satisfy this
preliminary hypothesis. Here, we determine the accuracy of the analytic
approximations to the period and damping time, and its impact on seismology
estimates, when largely nonuniform loops are considered. We find that the
accuracy of the approximations when used beyond their range of applicability is
strongly affected by the form of the density profile across the loop, that is
observationally unknown and so must be arbitrarily imposed as part of the
theoretical model. The error associated with the analytic approximations can be
larger than 50% even for relatively thin nonuniform layers. This error directly
affects the accuracy of approximate seismology estimates compared to actual
numerical inversions. In addition, assuming different density profiles can
produce noncoincident intervals of the seismic variables in inversions of the
same event. The ignorance about the true shape of density variation across the
loop is an important source of error that may dispute the reliability of
parameters seismically inferred assuming an ad hoc density profile.


title: Research Directions in Network Service Chaining

abstract:
  Network Service Chaining (NSC) is a service deployment concept that promises
increased flexibility and cost efficiency for future carrier networks. NSC has
received considerable attention in the standardization and research communities
lately. However, NSC is largely undefined in the peer-reviewed literature. In
fact, a literature review reveals that the role of NSC enabling technologies is
up for discussion, and so are the key research challenges lying ahead. This
paper addresses these topics by motivating our research interest towards
advanced dynamic NSC and detailing the main aspects to be considered in the
context of carrier-grade telecommunication networks. We present design
considerations and system requirements alongside use cases that illustrate the
advantages of adopting NSC. We detail prominent research challenges during the
typical lifecycle of a network service chain in an operational
telecommunications network, including service chain description, programming,
deployment, and debugging, and summarize our security considerations. We
conclude this paper with an outlook on future work in this area.


title:
The Fundamental Manifold of spiral galaxies: ordered versus random
  motions and the morphology dependence of the Tully-Fisher relation

abstract:
  (Abridged) We investigate the morphology dependence of the Tully-Fisher
relation, and the expansion of the relation into a three-dimensional manifold
defined by luminosity, total circular velocity and a third dynamical parameter,
to fully characterise spiral galaxies across all morphological types. We use a
semi-analytic hierarchical model of galaxy evolution to build the theoretical
TF relation. With this tool, we analyse a unique dataset of galaxies for which
we cross-match luminosity with total circular velocity and central velocity
dispersion. We provide a theoretical framework to calculate such measurable
quantities from semi-analytic models. We establish the morphology dependence of
the TF relation in both model and data. We analyse the dynamical properties of
the model galaxies and determine that the parameter 'sigma/Vc', i.e. the ratio
between random and total motions defined by velocity dispersion and circular
velocity, accurately characterises the varying slope of the TF relation for
different model galaxy types. We apply these dynamical cuts to the observed
galaxies and find that such selection produces a differential slope of the TF
relation. The TF slope in different ranges of 'sigma/Vc' is consistent with
that for the photometric classification in Sa, Sb, Sc. We conclude that
'sigma/Vc' is a good parameter to classify galaxy type, and we argue that such
classification based on dynamics more closely mirrors the physical properties
of the observed galaxies, compared to visual classification. We also argue that
dynamical classification is useful for samples where eye inspection is not
reliable or impractical. We conclude that 'sigma/Vc' is a suitable parameter to
characterise the hierarchical assembly history that determines the
disk-to-bulge ratio, and to expand the TF relation into a three-dimensional
manifold, defined by luminosity, circular velocity and 'sigma/Vc'.


title:
Unexpected properties of bandwidth choice when smoothing discrete data
  for constructing a functional data classifier

abstract:
  The data functions that are studied in the course of functional data analysis
are assembled from discrete data, and the level of smoothing that is used is
generally that which is appropriate for accurate approximation of the
conceptually smooth functions that were not actually observed. Existing
literature shows that this approach is effective, and even optimal, when using
functional data methods for prediction or hypothesis testing. However, in the
present paper we show that this approach is not effective in classification
problems. There a useful rule of thumb is that undersmoothing is often
desirable, but there are several surprising qualifications to that approach.
First, the effect of smoothing the training data can be more significant than
that of smoothing the new data set to be classified; second, undersmoothing is
not always the right approach, and in fact in some cases using a relatively
large bandwidth can be more effective; and third, these perverse results are
the consequence of very unusual properties of error rates, expressed as
functions of smoothing parameters. For example, the orders of magnitude of
optimal smoothing parameter choices depend on the signs and sizes of terms in
an expansion of error rate, and those signs and sizes can vary dramatically
from one setting to another, even for the same classifier.


title: Testing chameleon gravity with the Coma cluster

abstract:
  We propose a novel method to test the gravitational interactions in the
outskirts of galaxy clusters. When gravity is modified, this is typically
accompanied by the introduction of an additional scalar degree of freedom,
which mediates an attractive fifth force. The presence of an extra
gravitational coupling, however, is tightly constrained by local measurements.
In chameleon modifications of gravity, local tests can be evaded by employing a
screening mechanism that suppresses the fifth force in dense environments.
While the chameleon field may be screened in the interior of the cluster, its
outer region can still be affected by the extra force, introducing a deviation
between the hydrostatic and lensing mass of the cluster. Thus, the chameleon
modification can be tested by combining the gas and lensing measurements of the
cluster. We demonstrate the operability of our method with the Coma cluster,
for which both a lensing measurement and gas observations from the X-ray
surface brightness, the X-ray temperature, and the Sunyaev-Zel'dovich effect
are available. Using the joint observational data set, we perform a Markov
chain Monte Carlo analysis of the parameter space describing the different
profiles in both the Newtonian and chameleon scenarios. We report competitive
constraints on the chameleon field amplitude and its coupling strength to
matter. In the case of f(R) gravity, corresponding to a specific choice of the
coupling, we find an upper bound on the background field amplitude of
|f_{R0}|<6*10^{-5}, which is currently the tightest constraint on cosmological
scales.


title: Elliptical instability of compressible flow in ellipsoids

abstract:
  Elliptical instability is due to a parametric resonance of two inertial modes
in a fluid velocity field with elliptical streamlines. This flow is a simple
model of the motion in a tidally deformed, rotating body. Elliptical
instability typically leads to three-dimensional turbulence. The associated
turbulent dissipation together with the dissipation of the large scale mode may
be important for the synchronization process in stellar and planetary binary
systems. In order to determine the influence of the compressibility on the
stability limits of tidal flows in stars or planets, we calculate the growth
rates of perturbations in flows with elliptical streamlines within ellipsoidal
boundaries of small ellipticity. In addition, the influence of the orbiting
frequency of the tidal perturber $\Omega_P$ and the viscosity of the fluid are
taken into account.


title: A complementary set theory for quaternary code designs

abstract:
  Quaternary code (QC) designs form an attractive class of nonregular factorial
fractions. We develop a complementary set theory for characterizing optimal QC
designs that are highly fractionated in the sense of accommodating a large
number of factors. This is in contrast to existing theoretical results which
work only for a relatively small number of factors. While the use of imaginary
numbers to represent the Gray map associated with QC designs facilitates the
derivation, establishing a link with foldovers of regular fractions helps in
presenting our results in a neat form.


title: Design of a 325MHz SC Spoke040 cavity at IHEP

abstract:
  The 325MHz, {\beta}=0.40 superconducting single spoke cavity (Spoke040) was
one of the most challenges for the China-ADS (Accelerator Driven System)
project. The design was finished, and the fabrication was in progressing. In
this paper, we studied the main radio frequency (RF) and mechanical parameters,
and compared the arc-shaped and plate-shaped end group structures.


title: A new combinatorial class of 3-manifold triangulations

abstract:
  We define a new combinatorial class of triangulations of closed 3-manifolds,
satisfying a weak version of 0-efficiency combined with a weak version of
minimality, and study them using twisted squares. As an application, we obtain
strong restrictions on the topology of a 3-manifold from the existence of
non-smooth maxima of the volume function on the space of circle-valued angle
structures.


title:
The eclipsing post-common envelope binary CSS21055: a white dwarf with a
  probable brown-dwarf companion

abstract:
  We report photometric observations of the eclipsing close binary CSS21055
(SDSS J141126+200911) that strongly suggest that the companion to the
carbon-oxygen white dwarf is a brown dwarf with a mass between 0.030 and 0.074
Msun. The measured orbital period is 121.73min and the totality of the eclipse
lasts 125s. If confirmed, CSS21055 would be the first detached eclipsing WD+BD
binary. Spectroscopy in the eclipse could provide information about the
companion's evolutionary state and atmospheric structure.


title:
Long-distance asymptotic behaviour of multi-point correlation functions
  in massless quantum models

abstract:
  We provide a microscopic model setting that allows us to readily access to
the large-distance asymptotic behaviour of multi-point correlation functions in
massless, one-dimensional, quantum models. The method of analysis we propose is
based on the form factor expansion of the correlation functions and does not
build on any field theory reasonings. It constitutes an extension of the
restricted sum techniques leading to the large-distance asymptotic behaviour of
two-point correlation functions obtained previously.

categories: math-ph cond-mat.stat-mech math.MP nlin.SI


title: Reflection of nanoparticles

abstract:
  This work is devoted to molecular dynamics modeling of collision of
nanoparticle having a small number of degrees of freedom with a structureless
plain. The new regularities are established that determine properties of such
particles. Generalized collision law is obtained where particle properties are
determined by two coefficient, on of which corresponds to restitution
coefficient. The discovered regularity predicts the existence of anomalous mode
of particle reflection from a massive plain. In this mode, velocity of
nanoparticle after reflection from a plain can exceed the initial one. The
criterion of realization of such mode is obtained. Anomalous collision mode was
observed during numerical modeling. Physical mechanism are discussed of
phenomena that are observed during numerical experiments.


title:
Discrete spectrum of kink velocities in Josephson structures: the
  nonlocal double sine-Gordon model

abstract:
  We study a model of Josephson layered structure which is characterized by two
peculiarities: (i) superconducting layers are thin; (ii) due to suppression of
superconducting states in superconducting layers the current-phase relation is
non-sinusoidal and is described by two sine harmonics. The governing equation
is a nonlocal generalization of double sine-Gordon (NDSG) equation. We argue
that the dynamics of fluxons in the NDSG model is unusual. Specifically, we
show that there exists a set of particular velocities for non-radiating fluxon
propagation. In dynamics the presence of these ``priveleged'' velocitied
results in phenomenon of quantization of fluxon velocities: in our numerical
experiments a travelling kink-like excitation radiates energy and slows down to
one of these particular velocities, taking a shape of predicted 2-pi-kink. This
situation differs from both, double sine-Gordon local model and the nonlocal
sine-Gordon model, considered before. We conjecture that the set of these
velocities is infinite and present an asymptotic formula for them.


title: Saddle-splay screening and chiral symmetry breaking in toroidal nematics

abstract:
  We present a theoretical study of director fields in toroidal geometries with
degenerate planar boundary conditions. We find spontaneous chirality: despite
the achiral nature of nematics the director configuration show a handedness if
the toroid is thick enough. In the chiral state the director field displays a
double twist, whereas in the achiral state there is only bend deformation. The
critical thickness increases as the difference between the twist and
saddle-splay moduli grows. A positive saddle-splay modulus prefers alignment
along the short circle of the bounding torus, and hence stimulates promotes a
chiral configuration. The chiral-achiral transition mimics the order-disorder
transition of the mean-field Ising model. The role of the magnetisation in the
Ising model is played by the degree of twist. The role of the temperature is
played by the aspect ratio of the torus. Remarkably, an external field does not
break the chiral symmetry explicitly, but shifts the transition. In the case of
toroidal cholesterics, we do find a preference for one chirality over the other
-- the molecular chirality acts as a field in the Ising analogy.


title: Octet magnetic Moments and their sum rules in statistical model

abstract:
  The statistical model is implemented to find the magnetic moments of all
octet baryons. The well-known sum rules like GMO and CG sum rules has been
checked in order to check the consistency of our approach. The small
discrepancy between the results suggests the importance of breaking in SU(3)
symmetry.


title: Anomalous Quark Chromomagnetic Moment and Dynamics of Elastic Scattering

abstract:
  We estimate the contribution of nonperturbative quark-gluon chromomagnetic
interaction to the high energy elastic proton-proton cross section at large
momentum transfer. It is shown that this contribution is very large in the
accessible kinematic region of the present experiments.
  We argue that Odderon which is the $P=C=-1$ partner of Pomeron, is governed
by the spin-flip component related to the nonperturbative three-gluon exchange
induced by the anomalous quark chromomagnetic moment. We discuss the possible
spin effects in the elastic proton-proton and proton-antiproton scattering
coming from the interference of spin-flip nonperturbative Odderon and
nonspin-flip Pomeron exchanges.


title: Transient Growth of Ekman-Couette Flow

abstract:
  Coriolis force effects on shear flows are important in geophysical and
astrophysical contexts. We here report a study on the linear stability and the
transient energy growth of the plane Couette flow with system rotation
perpendicular to the shear direction. External rotation causes linear
instability. At small rotation rates, the onset of linear instability scales
inversely with the rotation rate and the optimal transient growth in the
linearly stable region is slightly enhanced, ~Re^2. The corresponding optimal
initial perturbations are characterized by roll structures inclined in the
streamwise direction and are twisted under external rotation. At large rotation
rates, the transient growth is significantly inhibited and hence linear
stability analysis is a reliable indicator for instability.


title: Analysis of MIMO Systems used in planning a 4G-WiMAX Network in Ghana

abstract:
  With the increasing demand for mobile data services, Broadband Wireless
Access (BWA) is emerging as one of the fastest growing areas within mobile
communications. Innovative wireless communication systems, such as WiMAX, are
expected to offer highly reliable broadband radio access in order to meet the
increasing demands of emerging high speed data and multimedia services. In
Ghana, deployment of WiMAX technology has recently begun. Planning these high
capacity networks in the presence of multiple interferences in order to achieve
the aim of enabling users enjoy cheap and reliable internet services is a
critical design issue. This paper has used a deterministic approach for
simulating the Bit-Error-Rate (BER) of initial MIMO antenna configurations
which were considered in deploying a high capacity 4G-WiMAX network in Ghana.
The radiation pattern of the antenna used in the deploying the network has been
simulated with Genex-Unet and NEC and results presented. An adaptive 4x4 MIMO
antenna configuration with optimally suppressed sidelobes has been suggested
for future network deployment since the adaptive 2x2 MIMO antenna
configuration, which was used in the initial network deployment provides poor
estimates for average BER performance as compared to 4x4 antenna configuration
which seem less affected in the presence of multiple interferers.


title: A Cellular Automaton Based Controller for a Ms. Pac-Man Agent

abstract:
  Video games can be used as an excellent test bed for Artificial Intelligence
(AI) techniques. They are challenging and non-deterministic, this makes it very
difficult to write strong AI players. An example of such a video game is Ms.
Pac-Man. In this paper we will outline some of the previous techniques used to
build AI controllers for Ms. Pac-Man as well as presenting a new and novel
solution. My technique utilises a Cellular Automaton (CA) to build a
representation of the environment at each time step of the game. The basis of
the representation is a 2-D grid of cells. Each cell has a state and a set of
rules which determine whether or not that cell will dominate (i.e. pass its
state value onto) adjacent cells at each update. Once a certain number of
update iterations have been completed, the CA represents the state of the
environment in the game, the goals and the dangers. At this point, Ms. Pac-Man
will decide her next move based only on her adjacent cells, that is to say, she
has no knowledge of the state of the environment as a whole, she will simply
follow the strongest path. This technique shows promise and allows the
controller to achieve high scores in a live game, the behaviour it exhibits is
interesting and complex. Moreover, this behaviour is produced by using very
simple rules which are applied many times to each cell in the grid. Simple
local interactions with complex global results are truly achieved.


title: Beyond Reggeization for two- and three-loop QCD amplitudes

abstract:
  The high-energy factorization of gauge theory scattering amplitudes in terms
of universal impact factors and a Reggeized exchange in the $t$-channel,
corresponding to a Regge pole in the angular momentum plane, is know to
conflict with the structure of soft anomalous dimensions starting at the
two-loop level. We explore the implications of this violation of factorization
for two- and three-loop QCD amplitudes: first we propose criteria to organize
the amplitudes into factorizing and non-factorizing terms, then we test them by
recovering a known result for non-logarithmic terms at two loops. Finally we
predict the precise value of the leading non-factorizing energy logarithms at
three loops, and we uncover a set of all-order identities constraining infrared
finite terms in quark and gluon amplitudes.


title:
Simultaneous optical/gamma-ray observations of GRB 121217's prompt
  emission

abstract:
  Since the advent of the Swift satellite it has been possible to obtain
precise localisations of GRB positions of sub-arcsec accuracy within seconds,
facilitating ground-based robotic telescopes to automatically slew to the
target within seconds. This has yielded a plethora of observational data for
the afterglow phase of the GRB, but the quantity of data (<2 keV) covering the
initial prompt emission still remains small. Only in a handful of cases has it
been possible obtain simultaneous coverage of the prompt emission in a
multi-wavelength regime (gamma-ray to optical), as a result of: observing the
field by chance prior to the GRB (e.g. 080319B/naked-eye burst), long-prompt
emission (e.g., 080928, 110205A) or triggered on a pre-cursor (e.g., 041219A,
050820A, 061121). This small selection of bursts have shown both correlated and
uncorrelated gamma-ray and optical light curve behaviour, and the
multi-wavelength emission mechanism remains far from resolved (i.e. single
population synchrotron self-Component, electron distributions, additional
neutron components or residual collisions). Such multi-wavelength observations
during the GRB prompt phase are pivotal in providing further insight on the
poorly understood prompt emission mechanism. We add to this small sample the
Swift burst 121217A that had two distinct periods of prompt emission separated
by ~700 s, observed by Swift/BAT, Swift/XRT and Fermi/GBM. As a result of the
time delay of the second emission, it enabled optical imaging (from 3 to 7
bands) to be taken with the GROND instrument to a resolution as fine as 10s.
This multi-wavelength data will hopefully allow us to shed more light on the
current picture of prompt emission physics.


title: Effects of Noncommutativity on the Black Hole Entropy

abstract:
  In this paper the BTZ black hole geometry is probed with a noncommutative
scalar field which obeys the $\kappa$-Minkowski algebra. The entropy of the BTZ
black hole is calculated using the brick wall method. The contribution of the
noncommutativity to the black hole entropy is explicitly evaluated up to the
first order in the deformation parameter. We also argue that such a correction
to the black hole entropy can be interpreted as arising from the
renormalization of the Newton's constant due to the effects of the
noncommutativity.


title: Long term characterization of voltage references

abstract:
  We report here the characterization (temperature coefficients and noise
level) of selected voltage references in the frequency range from 10^(-5) to 10
Hz. The goal of this work is to update previous studies, with a
characterization at lower frequencies, and find voltage references that may be
suitable for the space-based interferometry mission eLISA. The requirements of
relative output stability of 1 ppm/$\sqrt{\text{Hz}}$ down to 0.1 mHz were not
met by any of the tested devices, but 4 references approaches the objective :
the AD587UQ, the MAX6126AASA50, the LT1021-BCN8-5 and the LT6655BHM. While the
first three were already identified as potential devices in previous studies,
the later is a new promising candidate using a different technology (bandgap).


title: Complex Statistics and Diffusion in Nonlinear Disordered Particle Chains

abstract:
  We investigate dynamically and statistically diffusive motion in a
Klein-Gordon particle chain in the presence of disorder. In particular, we
examine a low energy (subdiffusive) and a higher energy (self-trapping) case
and verify that subdiffusive spreading is always observed. We then carry out a
statistical analysis of the motion in both cases in the sense of the Central
Limit Theorem and present evidence of different chaos behaviors, for various
groups of particles. Integrating the equations of motion for times as long as
$10^9$, our probability distribution functions always tend to Gaussians and
show that the dynamics does not relax onto a quasi-periodic KAM torus and that
diffusion continues to spread chaotically for arbitrarily long times.


title:
Tests alternative to higher criticism for high-dimensional means under
  sparsity and column-wise dependence

abstract:
  We consider two alternative tests to the Higher Criticism test of Donoho and
Jin [Ann. Statist. 32 (2004) 962-994] for high-dimensional means under the
sparsity of the nonzero means for sub-Gaussian distributed data with unknown
column-wise dependence. The two alternative test statistics are constructed by
first thresholding $L_1$ and $L_2$ statistics based on the sample means,
respectively, followed by maximizing over a range of thresholding levels to
make the tests adaptive to the unknown signal strength and sparsity. The two
alternative tests can attain the same detection boundary of the Higher
Criticism test in [Ann. Statist. 32 (2004) 962-994] which was established for
uncorrelated Gaussian data. It is demonstrated that the maximal
$L_2$-thresholding test is at least as powerful as the maximal
$L_1$-thresholding test, and both the maximal $L_2$ and $L_1$-thresholding
tests are at least as powerful as the Higher Criticism test.


title: Relation of deformed nonlinear algebras with linear ones

abstract:
  The relation between nonlinear algebras and linear ones is established. For
one-dimensional nonlinear deformed Heisenberg algebra with two operators we
find the function of deformation for which this nonlinear algebra can be
transformed to a linear one with three operators. We also establish the
relation between Lie algebra of total angular momentum and corresponding
nonlinear one. This relation gives a possibility to simplify and to solve the
eigenvalue problem for the Hamiltonian in a nonlinear case using the reduction
of this problem to the case of linear algebra. It is demonstrated on the
example of harmonic oscillator.


title: Local correlation clustering

abstract:
  Correlation clustering is perhaps the most natural formulation of clustering.
Given $n$ objects and a pairwise similarity measure, the goal is to cluster the
objects so that, to the best possible extent, similar objects are put in the
same cluster and dissimilar objects are put in different clusters. Despite its
theoretical appeal, the practical relevance of correlation clustering still
remains largely unexplored, mainly due to the fact that correlation clustering
requires the $\Theta(n^2)$ pairwise similarities as input.
  In this paper we initiate the investigation into \emph{local} algorithms for
correlation clustering. In \emph{local correlation clustering} we are given the
identifier of a single object and we want to return the cluster to which it
belongs in some globally consistent near-optimal clustering, using a small
number of similarity queries. Local algorithms for correlation clustering open
the door to \emph{sublinear-time} algorithms, which are particularly useful
when the similarity between items is costly to compute, as it is often the case
in many practical application domains. They also imply $(i)$ distributed and
streaming clustering algorithms, $(ii)$ constant-time estimators and testers
for cluster edit distance, and $(iii)$ property-preserving parallel
reconstruction algorithms for clusterability.
  Specifically, we devise a local clustering algorithm attaining a $(3,
\varepsilon)$-approximation in time $O(1/\varepsilon^2)$ independently of the
dataset size. An explicit approximate clustering for all objects can be
produced in time $O(n/\varepsilon)$ (which is provably optimal). We also
provide a fully additive $(1,\varepsilon)$-approximation with local query
complexity $poly(1/\varepsilon)$ and time complexity $2^{poly(1/\varepsilon)}$.
The latter yields the fastest polynomial-time approximation scheme for
correlation clustering known to date.


title: Codes between MBR and MSR Points with Exact Repair Property

abstract:
  In this paper distributed storage systems with exact repair are studied. A
construction for regenerating codes between the minimum storage regenerating
(MSR) and the minimum bandwidth regenerating (MBR) points is given. To the best
of author's knowledge, no previous construction of exact-regenerating codes
between MBR and MSR points is done except in the work by Tian et al. On
contrast to their work, the methods used here are elementary.
  In this paper it is shown that in the case that the parameters $n$, $k$, and
$d$ are close to each other, the given construction is close to optimal when
comparing to the known functional repair capacity. This is done by showing that
when the distances of the parameters $n$, $k$, and $d$ are fixed but the actual
values approach to infinity, the fraction of the performance of constructed
codes with exact repair and the known capacity of codes with functional repair,
approaches to one. Also a simple variation of the constructed codes with almost
the same performance is given.


title:
On maximum-principle functions for flows by powers of the Gauss
  curvature

abstract:
  We consider flows with normal velocities equal to powers strictly larger than
one of the Gauss curvature. Under such flows closed strictly convex surfaces
converge to points. In his work on the square of the norm of the second
fundamental form, Schn\"urer proposes criteria for selecting quantities that
are suitable for proving convergence to a round point. Such monotone quantities
exist for many normal velocities, including the Gauss curvature, some powers
larger than one of the mean curvature, and some powers larger than one of the
norm of the second fundamental form. In this paper, we show that no such
quantity exists for any powers larger than one of the Gauss curvature.


title:
Large $3$-groups of automorphisms of algebraic curves in characteristic
  $3$

abstract:
  Let $S$ be a $p$-subgroup of the $\K$-automorphism group $\aut(\cX)$ of an
algebraic curve $\cX$ of genus $\gg\ge 2$ and $p$-rank $\gamma$ defined over an
algebraically closed field $\mathbb{K}$ of characteristic $p\geq 3$.In this
paper we prove that if $|S|>2(\gg-1)$ then one of the following cases occurs.
\begin{itemize} \item[(i)] $\gamma=0$ and the extension $\K(\cX)/\K(\cX)^S$
completely ramifies at a unique place, and does not ramify elsewhere.
\item[(ii)] $\gamma>0$, $p=3$, $\cX$ is a general curve, $S$ attains the
Nakajima's upper bound $3(\gamma-1)$ and $\K(\cX)$ is an unramified Galois
extension of the function field of a general curve of genus $2$ with equation
$Y^2=cX^6+X^4+X^2+1$ where $c\in\K^*$. \end{itemize} Case (i) was investigated
by Stichtenoth, Lehr, Matignon, and Rocher.


title:
Wideband Parameters Analysis and Validation for Indoor radio Channel at
  60/70/80GHz for Gigabit Wireless Communication employing Isotropic, Horn and
  Omni directional Antenna

abstract:
  Recently, applications of millimeter (mm) waves for high-speed broadband
wireless local area network communication systems in indoor environment are
increasingly gaining recognition as it provides gigabit-speed wireless
communications with carrier-class performances over distances of a mile or more
due to spectrum availability and wider bandwidth requirements. Collectively
referred to as E-Band, the millimeter wave wireless technology present the
potential to offer bandwidth delivery comparable to that of fiber optic, but
without the financial and logistic challenges of deploying fiber. This paper
investigates the wideband parameters using the ray tracing technique for indoor
propagation systems with rms delay spread for Omnidirectional and Horn Antennas
for Bent Tunnel at 80GHz. The results obtained were 2.03 and 1.95 respectively,
besides, the normalized received power with 0:55fix10^8 excess delay at 70GHz
for Isotropic Antenna was at 0.97.


title: Roles of the kinetic and dynamic mechanisms in the $L_p - E_p$ relation

abstract:
  The $L_p - E_p$ relation is a well-known relation in gamma-ray bursts. Its
implication remains unclear. We propose to investigate the underlying
mechanisms of this relation by considering the corresponding kinetic and
dynamic mechanisms separately. In this way, one can tell how much the kinetic
or dynamic mechanism contributes to the index of the relationship. Our analysis
gives rise to several conclusions. (1) The index of the kinetic effect in the
$L_p - E_p$ relation can simply be derived from the theory of special
relativity, which is generally larger than 2, depending on the situation
concerned. (2) The index of the dynamic effect in the relation can be deduced
from observation once a model of jets is adopted. According to current GRB
data, we find: the dynamic effect alone tends to make an anti-correlation
between $L_p$ and $E_p$; in terms of statistics, the dynamic effect is
obviously smaller than the kinetic effect; in the situation of jets with moving
discrete radio clouds which moves directly towards the observer, the index of
the dynamic effect is currently constrained within $(-1.6, -1)$, while in other
situations of jets, the constrains are different; both internal and external
shocks can account for the current data.


title:
Long Time No See: The Probability of Reusing Tags as a Function of
  Frequency and Recency

abstract:
  In this paper, we introduce a tag recommendation algorithm that mimics the
way humans draw on items in their long-term memory. This approach uses the
frequency and recency of previous tag assignments to estimate the probability
of reusing a particular tag. Using three real-world folksonomies gathered from
bookmarks in BibSonomy, CiteULike and Flickr, we show how adding a
time-dependent component outperforms conventional "most popular tags"
approaches and another existing and very effective but less theory-driven,
time-dependent recommendation mechanism. By combining our approach with a
simple resource-specific frequency analysis, our algorithm outperforms other
well-established algorithms, such as FolkRank, Pairwise Interaction Tensor
Factorization and Collaborative Filtering. We conclude that our approach
provides an accurate and computationally efficient model of a user's temporal
tagging behavior. We show how effective principles for information retrieval
can be designed and implemented if human memory processes are taken into
account.


title:
Fourth order compact schemes for variable coefficient parabolic problems
  with mixed derivatives

abstract:
  In this article, we have developed a higher order compact numerical method
for variable coefficient parabolic problems with mixed derivatives. The finite
difference scheme, presented here for two-dimensional domains, is based on
fourth order spatial discretization. The time discretization has been carried
out using using second order Crank-Nicolson. The present scheme shows good
dispersion relation preserving property and has been thoroughly investigated
for stability. The discrete Fourier analysis shows that the method is
unconditionally stable. The fact that the method has been particularly
developed for parabolic equations with mixed derivatives makes it suitable for
solving incompressible Navier-Stokes (N-S) equations in irregular domains. To
verify the proposed method, several problems with exact and benchmark solutions
has been investigated. The proposed compact discretization has been extended to
tackle flows of varying complexities governed by the two-dimensional unsteady
N-S equations in domain beyond rectangular. The results show good agreement for
all the problems considered.


title:
Multipolar, magnetic and vibrational lattice dynamics in the low
  temperature phase of uranium dioxide

abstract:
  We report the results of inelastic neutron scattering experiments performed
with triple-axis spectrometers to investigate the low-temperature collective
dynamics in the ordered phase of uranium dioxide. The results are in excellent
agreement with the predictions of mean-field RPA calculations emphasizing the
importance of multipolar superexchange interactions. By comparing neutron
scattering intensities in different polarization channels and at equivalent
points in different Brillouin zones, we show the mixed
magneto-vibrational-quadrupolar character of the observed excitations. The high
energy resolution afforded by the cold triple-axis spectrometer allowed us to
study in detail the magnon-phonon interaction giving rise to avoided crossings
along the $[00\xi]$ reciprocal space direction.


title:
A general theory of particle filters in hidden Markov models and some
  applications

abstract:
  By making use of martingale representations, we derive the asymptotic
normality of particle filters in hidden Markov models and a relatively simple
formula for their asymptotic variances. Although repeated resamplings result in
complicated dependence among the sample paths, the asymptotic variance formula
and martingale representations lead to consistent estimates of the standard
errors of the particle filter estimates of the hidden states.


title:
Robustness of quadratic hedging strategies in finance via backward
  stochastic differential equations with jumps

abstract:
  We consider a backward stochastic differential equation with jumps (BSDEJ)
which is driven by a Brownian motion and a Poisson random measure. We present
two candidate-approximations to this BSDEJ and we prove that the solution of
each candidate- approximation converges to the solution of the original BSDEJ
in a space which we specify. We use this result to investigate in further
detail the consequences of the choice of the model to (partial) hedging in
incomplete markets in finance. As an application, we consider models in which
the small variations in the price dynamics are modeled with a Poisson random
measure with infinite activity and models in which these small variations are
modeled with a Brownian motion. Using the convergence results on BSDEJs, we
show that quadratic hedging strategies are robust towards the choice of the
model and we derive an estimation of the model risk.


title: Sensitivity analysis in a market with memory

abstract:
  A general market model with memory is considered in terms of stochastic
functional differential equations. We aim at representation formulae for the
sensitivity analysis of the dependence of option prices on the memory. This
implies a generalization of the concept of delta.


title:
Comparison of two semiclassical expansions for a family of PT-symmetric
  oscillators

abstract:
  We show that a recently developed semiclassical expansion for the eigenvalues
of PT-symmetric oscillators of the form $V(x)=(ix)^{2N+1}+bix$ does not agree
with an earlier WKB expression for $V(x)=-(ix)^{2N+1}$ the case $b=0$. The
reason is due to the choice of different paths in the complex plane for the
calculation of the WKB integrals. We compare the Stokes and anti-Stokes lines
that apply to each case for the quintic oscillator and derive a general WKB
expression that contains the two earlier ones.


title: On improved fractional Sobolev-Poincar\'e inequalities

abstract:
  We prove a certain improved fractional Sobolev-Poincar\'e inequality on John
domains; the proof is based on the equivalence of the corresponding weak and
strong type inequalities. We also give necessary conditions for the validity of
an improved fractional Sobolev-Poincar\'e inequality, in particular, we show
that a domain having a finite measure and satisfying this inequality, and a
`separation property', is a John domain.


title:
Spectral statistics of large dimensional Spearman's rank correlation
  matrix and its application

abstract:
  Let $\mathbf{Q}=(Q_1,\ldots,Q_n)$ be a random vector drawn from the uniform
distribution on the set of all $n!$ permutations of $\{1,2,\ldots,n\}$. Let
$\mathbf{Z}=(Z_1,\ldots,Z_n)$, where $Z_j$ is the mean zero variance one random
variable obtained by centralizing and normalizing $Q_j$, $j=1,\ldots,n$. Assume
that $\mathbf {X}_i,i=1,\ldots ,p$ are i.i.d. copies of
$\frac{1}{\sqrt{p}}\mathbf{Z}$ and $X=X_{p,n}$ is the $p\times n$ random matrix
with $\mathbf{X}_i$ as its $i$th row. Then $S_n=XX^*$ is called the $p\times n$
Spearman's rank correlation matrix which can be regarded as a high dimensional
extension of the classical nonparametric statistic Spearman's rank correlation
coefficient between two independent random variables. In this paper, we
establish a CLT for the linear spectral statistics of this nonparametric random
matrix model in the scenario of high dimension, namely, $p=p(n)$ and $p/n\to
c\in(0,\infty)$ as $n\to\infty$. We propose a novel evaluation scheme to
estimate the core quantity in Anderson and Zeitouni's cumulant method in [Ann.
Statist. 36 (2008) 2553-2576] to bypass the so-called joint cumulant
summability. In addition, we raise a two-step comparison approach to obtain the
explicit formulae for the mean and covariance functions in the CLT. Relying on
this CLT, we then construct a distribution-free statistic to test complete
independence for components of random vectors. Owing to the nonparametric
property, we can use this test on generally distributed random variables
including the heavy-tailed ones.


title: BSDEs driven by time-changed L\'evy noises and optimal control

abstract:
  We study backward stochastic differential equations (BSDEs) for time-changed
L\'evy noises when the time-change is independent of the L\'evy process. We
prove existence and uniqueness of the solution and we obtain an explicit
formula for linear BSDEs and a comparison principle. BSDEs naturally appear in
control problems. Here we prove a sufficient maximum principle for a general
optimal control problem of a system driven by a time-changed L\'evy noise. As
an illustration we solve the mean-variance portfolio selection problem.


title: Oscillator tunneling dynamics in the Rabi model

abstract:
  The familiar Rabi model, comprising a two-level system coupled to a quantum
harmonic oscillator, continues to produce rich and surprising physics when the
coupling strength becomes comparable to the individual subsystem frequencies.
We construct approximate solutions for the regime in which the oscillator
frequency is small compared to that of the two-level system and the coupling
strength matches or exceeds the oscillator frequency. Relating our fully
quantum calculation to a previous semi-classical approximation, we find that
the dynamics of the oscillator can be considered to a good approximation as
that of a particle tunneling in a classical double-well potential, despite the
fundamentally entangled nature of the joint system. We assess the prospects for
observation of oscillator tunneling in the context of nano- or micro-mechanical
experiments and find that it should be possible if suitably high coupling
strengths can be engineered.


title:
X-ray observations of VY Scl type nova-like binaries in the high and low
  state

abstract:
  Four VY Scl-type nova-like systems were observed in X-rays both during the
low and the high optical states. They are BZ Cam, MV Lyr, TT Ari, and V794 Aql.
Using archival ROSAT, Swift and SUZAKU observations we found that the X-ray
flux for BZ Cam is higher during the low state, but there is no supersoft X-ray
source (SSS) that would indicate the thermonuclear burning predicted in a
previous article. The X-ray flux is lower by a factor 2-10 in the low than the
high state in other systems, and does not reflect the drop in $\dot{M}$
inferred from optical and UV data.
  The best fit model for the X-ray spectra is a collisionally ionized plasma
model. The X-ray flux may originate in a shocked wind or in accretion onto
polar caps in intermediate polar systems that continues even during the low
state.


title: On kernel smoothing for extremal quantile regression

abstract:
  Nonparametric regression quantiles obtained by inverting a kernel estimator
of the conditional distribution of the response are long established in
statistics. Attention has been, however, restricted to ordinary quantiles
staying away from the tails of the conditional distribution. The purpose of
this paper is to extend their asymptotic theory far enough into the tails. We
focus on extremal quantile regression estimators of a response variable given a
vector of covariates in the general setting, whether the conditional
extreme-value index is positive, negative, or zero. Specifically, we elucidate
their limit distributions when they are located in the range of the data or
near and even beyond the sample boundary, under technical conditions that link
the speed of convergence of their (intermediate or extreme) order with the
oscillations of the quantile function and a von-Mises property of the
conditional distribution. A simulation experiment and an illustration on real
data were presented. The real data are the American electric data where the
estimation of conditional extremes is found to be of genuine interest.


title:
Permuted NMF: A Simple Algorithm Intended to Minimize the Volume of the
  Score Matrix

abstract:
  Non-Negative Matrix Factorization, NMF, attempts to find a number of
archetypal response profiles, or parts, such that any sample profile in the
dataset can be approximated by a close profile among these archetypes or a
linear combination of these profiles. The non-negativity constraint is imposed
while estimating archetypal profiles, due to the non-negative nature of the
observed signal. Apart from non negativity, a volume constraint can be applied
on the Score matrix W to enhance the ability of learning parts of NMF. In this
report, we describe a very simple algorithm, which in effect achieves volume
minimization, although indirectly.


title: Wei-Norman equations for classical groups

abstract:
  We show that the non-linear autonomus Wei-Norman equations, expressing the
solution of a linear system of non-autonomous equations on a Lie algebra, can
be reduced to the hierarchy of matrix Riccati equations in the case of all
classical simple Lie algebras. The result generalizes our previous one
concerning the complex Lie algebra of the special linear group. We show that it
cannot be extended to all simple Lie algebras, in particular to the exceptional
$G_2$ algebra.


title:
On the least positive solution to a proportionally modular Diophantine
  inequality

abstract:
  Given three positive integers $a,b,c$, a proportionally modular Diophantine
inequality is an expression of the form $ax \mod{b} \le cx$. Our aim is to give
a recursive formula for the least solution to such an inequality. We then use
the formula to derive an algorithm. Finally, we apply our results to a question
of Rosales and Garc\'ia-S\'anchez.


title: Representations of $\bar{U}_q s\ell(2|1)$ at even roots of unity

abstract:
  We construct all projective modules of the restricted quantum group
$\bar{U}_q s\ell(2|1)$ at an even, $2p$th, root of unity. This
$64p^4$-dimensional Hopf algebra is a common double bosonization,
$B(X^*)\otimes B(X)\otimes H$, of two rank-2 Nichols algebras $B(X)$ with
fermionic generator(s), with $H=Z_{2p}\otimes Z_{2p}$. The category of
$\bar{U}_q s\ell(2|1)$-modules is equivalent to the category of
Yetter--Drinfeld $B(X)$-modules in $C_{\rho}={}^H_H\!YD$, where coaction is
defined by a universal $R$-matrix $\rho$. As an application of the projective
module construction, we find the associative algebra structure and the
dimension, $5p^2-p+4$, of the $\bar{U}_q s\ell(2|1)$ center.


title: The magnetic configuration of a delta-spot

abstract:
  Sunspots, which harbor both magnetic polarities within one penumbra, are
called delta-spots. They are often associated with flares. Nevertheless, there
are only very few detailed observations of the spatially resolved magnetic
field configuration. We present an investigation performed with the Tenerife
Infrared Polarimeter at the Vacuum Tower Telescope in Tenerife. We observed a
sunspot with a main umbra and several additional umbral cores, one of them with
opposite magnetic polarity (the delta-umbra). The delta-spot is divided into
two parts by a line along which central emissions of the spectral line Ca II
854.2 nm appear. The Evershed flow comming from the main umbra ends at this
line. In deep photospheric layers, we find an almost vertical magnetic field
for the delta-umbra, and the magnetic field decreases rapidly with height,
faster than in the main umbra. The horizontal magnetic field in the direction
connecting main and delta-umbra is rather smooth, but in one location next to a
bright penumbral feature at some distance to the delta-umbra, we encounter a
change of the magnetic azimuth by 90 degrees from one pixel to the next. Near
the delta-umbra, but just outside, we encounter a blue-shift of the spectral
line profiles which we interpret as Evershed flow away from the delta-umbra.
Significant electric current densities are observed at the dividing line of the
spot and inside the delta-umbra.


title: Deep Learning Embeddings for Discontinuous Linguistic Units

abstract:
  Deep learning embeddings have been successfully used for many natural
language processing problems. Embeddings are mostly computed for word forms
although a number of recent papers have extended this to other linguistic units
like morphemes and phrases. In this paper, we argue that learning embeddings
for discontinuous linguistic units should also be considered. In an
experimental evaluation on coreference resolution, we show that such embeddings
perform better than word form embeddings.


title: Composite Higgs: searches for new physics at future $e^+e^-$ colliders

abstract:
  In this proceeding, we extend a previous analysis concerning the prospects of
a future electron-positron collider in testing the 4-Dimensional Composite
Higgs Model. In particular, we introduce two motivated benchmarks and study
them in Higgs-Strahlung, for three possible energy stages and different
luminosity options of such a machine and confront our results to the expected
experimental accuracies in the various accessible Higgs decay channels.


title: Hitting probabilities for random convex bodies and lattices of triangles

abstract:
  In the first part of this paper, we obtain symmetric formulae for the
probabilities that a plane convex body hits exactly 1, 2, 3, 4, 5 or 6
triangles of a lattice of congruent triangles in the plane. Furthermore, a very
simple formula for the expectation of the number of hit triangles is derived.
In the second part, we calculate the hitting probabilities in the cases where
the convex body is a rectangle, an ellipse and a half disc. Already known
results for a line segment (needle) follow as special cases of the rectangle
and the ellipse.


title: Valuative and geometric characterizations of Cox sheaves

abstract:
  We give an intrinsic characterization of Cox sheaves on Krull schemes in
terms of their valuative algebraic properties. We also provide a geometric
characterization of their graded relative spectra in terms of good quotients of
graded schemes, extending the work of Arzhantsev, Derenthal, Hausen and Laface
on relative spectra of Cox sheaves on normal varieties. Moreover, we obtain an
irredundant characterization of Cox rings which in turn produces a normality
criterion for certain graded rings.


title:
Low latency search for Gravitational waves from BH-NS binaries in
  coincidence with Short Gamma Ray Bursts

abstract:
  We propose a procedure to be used in the search for gravitational waves from
black hole-neutron star coalescing binaries, in coincidence with short
gamma-ray bursts. It is based on two recently proposed semi-analytic fits, one
reproducing the mass of the remnant disk surrounding the black hole which forms
after the merging as a function of some binary parameters, the second relating
the neutron star compactness, i.e. the ratio of mass and radius, with its tidal
deformability. Using a Fisher matrix analysis and the two fits, we assign a
probability that the emitted gravitational signal is associated to the
formation of an accreting disk massive enough to supply the energy needed to
power a short gamma ray burst. This information can be used in low-latency data
analysis to restrict the parameter space searching for gravitational wave
signals in coincidence with short gamma-ray bursts, and to gain information on
the dynamics of the coalescing system and on the internal structure of the
components. In addition, when the binary parameters will be measured with high
accuracy, it will be possible to use this information to trigger the search for
off-axis gamma-ray bursts afterglows.


title:
Bosonic fractional quantum Hall states on the torus from conformal field
  theory

abstract:
  The Kalmeyer-Laughlin state, which is a lattice version of the bosonic
Laughlin state at filling factor one half, has attracted much attention due to
its topological and chiral spin liquid properties. Here we show that the
Kalmeyer-Laughlin state on the torus can be expressed in terms of a correlator
of conformal fields from the $SU(2)_1$ Wess-Zumino-Witten model. This reveals
an interesting underlying mathematical structure and provides a natural way to
generalize the Kalmeyer-Laughlin state to arbitrary lattices on the torus. We
find that the many-body Chern number of the states is unity for more different
lattices, which suggests that the topological properties of the states are
preserved when the lattice is changed. Finally, we analyze the symmetry
properties of the states on square lattices.


title: Successful strategies for a queens placing game on an n x n chess board

abstract:
  In his list of open problems, Martin Erickson described a certain game: "Two
players alternately put queens on an n x n chess board so that each new queen
is not in range of any queen already on the board (the color of the queens is
unimportant). The last player who can move wins." Then he asked: "Who should
win?"
  Obviously, for n up to 3, the first player wins, if he does not miss to start
at the central position in the case n=3.
  In this article, we give very simple always winning strategies for the first
player if n is 4 or odd.
  The additionally (in the source package) provided computer program QPGAME3
has been used to check that there are successful strategies for the first
player if n is 6 or 8, and for the second player if n is 10, 12, 14, or 16.
  As discovered during the submission process of the first version of this
article, Hassan A Noon presented consistent results concerning values of n
which are odd or at most 10, in his B.A. thesis and, together with Glen Van
Brummelen, in a journal article.


title: On a Family of Random Noble Means Substitutions

abstract:
  In 1989, Godreche and Luck introduced the concept of local mixtures of
primitive substitution rules along the example of the well-known Fibonacci
substitution and foreshadowed heuristic results on the topological entropy and
the spectral type of the diffraction measure of associated point sets. In this
contribution, we present a generalisation of this concept by regarding the
so-called 'noble means families', each consisting of finitely many primitive
substitution rules that individually all define the same two-sided discrete
dynamical hull. We report about results in the randomised case on topological
entropy, ergodicity of the two-sided discrete hull, and the spectral type of
the diffraction measure of related point sets.


title:
A conjugate class of random probability measures based on tilting and
  with its posterior analysis

abstract:
  This article constructs a class of random probability measures based on
exponentially and polynomially tilting operated on the laws of completely
random measures. The class is proved to be conjugate in that it covers both
prior and posterior random probability measures in the Bayesian sense.
Moreover, the class includes some common and widely used random probability
measures, the normalized completely random measures (James (Poisson process
partition calculus with applications to exchangeable models and Bayesian
nonparametrics (2002) Preprint), Regazzini, Lijoi and Pr\"{u}nster (Ann.
Statist. 31 (2003) 560-585), Lijoi, Mena and Pr\"{u}nster (J. Amer. Statist.
Assoc. 100 (2005) 1278-1291)) and the Poisson-Dirichlet process (Pitman and Yor
(Ann. Probab. 25 (1997) 855-900), Ishwaran and James (J. Amer. Statist. Assoc.
96 (2001) 161-173), Pitman (In Science and Statistics: A Festschrift for Terry
Speed (2003) 1-34 IMS)), in a single construction. We describe an augmented
version of the Blackwell-MacQueen P\'{o}lya urn sampling scheme (Blackwell and
MacQueen (Ann. Statist. 1 (1973) 353-355)) that simplifies implementation and
provide a simulation study for approximating the probabilities of partition
sizes.


title: Locating Multiple Ultrasound Targets in Chorus

abstract:
  Ranging by Time of Arrival (TOA) of Narrow-band ultrasound (NBU) has been
widely used by many locating systems for its characteristics of low cost and
high accuracy. However, because it is hard to support code division multiple
access in narrowband signal, to track multiple targets, existing NBU-based
locating systems generally need to assign exclusive time slot to each target to
avoid the signal conflicts. Because the propagation speed of ultrasound is slow
in air, dividing exclusive time slots on a single channel causes the location
updating rate for each target rather low, leading to unsatisfied tracking
performances as the number of targets increases. In this paper, we investigated
a new multiple target locating method using NBU, called UltraChorus, which is
to locate multiple targets while allowing them sending NBU signals
simultaneously, i.e., in chorus mode. It can dramatically increase the location
updating rate. In particular, we investigated by both experiments and
theoretical analysis on the necessary and sufficient conditions for resolving
the conflicts of multiple NBU signals on a single channel, which is referred as
the conditions for chorus ranging and chorus locating. To tackle the difficulty
caused by the anonymity of the measured distances, we further developed
consistent position generation algorithm and probabilistic particle filter
algorithm}to label the distances by sources, to generate reasonable location
estimations, and to disambiguate the motion trajectories of the multiple
concurrent targets based on the anonymous distance measurements. Extensive
evaluations by both simulation and testbed were carried out, which verified the
effectiveness of our proposed theories and algorithms.


title:
Quench in 1D Bose-Hubbard Model: Topological Defects and Excitations
  from Kosterlitz-Thouless Phase Transition Dynamics

abstract:
  Kibble-Zurek mechanism (KZM) uses critical scaling to predict density of
topological defects and other excitations created in second order phase
transitions. We point out that simply inserting asymptotic critical exponents
deduced from the immediate vicinity of the critical point to obtain KZM
predictions can lead to results that are inconsistent with a more careful
KZM-like analysis based on causality -- on the comparison of the relaxation
time of the order parameter with the time "distance" from the critical point.
As a result, scaling of quench-generated excitations with quench rates can
exhibit behavior that is locally (i.e., in the neighborhood of any given quench
rate) well approximated by the power law, but with exponents that depend on
that rate, and that are quite different from the naive prediction based on the
critical exponents relevant for asymptotically long quench times.
Kosterlitz-Thouless scaling (that governs e.g. Mott insulator to superfluid
transition in the Bose-Hubbard model in one dimension) is investigated as an
example of this phenomenon.


title: Free actions of free groups on countable structures and property (T)

abstract:
  We show that if $G$ is a non-archimedean, Roelcke precompact, Polish group,
then $G$ has Kazhdan's property (T). Moreover, if $G$ has a smallest open
subgroup of finite index, then $G$ has a finite Kazhdan set. Examples of such
$G$ include automorphism groups of countable $\omega$-categorical structures,
that is, the closed, oligomorphic permutation groups on a countable set. The
proof uses work of the second author on the unitary representations of such
groups, together with a separation result for infinite permutation groups. The
latter allows the construction of a non-abelian free subgroup of $G$ acting
freely in all infinite transitive permutation representations of $G$.


title: Automatic continuity for isometry groups

abstract:
  We present a general framework for automatic continuity results for groups of
isometries of metric spaces. In particular, we prove automatic continuity
property for the group of isometries of the Urysohn space and the Urysohn
sphere, i.e. that any homomorphism from either of these groups into a separable
group is continuous. As a consequence, we get that the group of isometries of
the Urysohn space has unique Polish group topology and the group of isometries
of the Urysohn sphere has unique separable group topology. Moreover, as an
application of our framework we obtain new proofs of the automatic continuity
property for the group $\mathrm{Aut}([0,1],\lambda)$, due to Ben Yaacov,
Berenstein and Melleray and for the unitary group of the infinite-dimensional
separable Hilbert space, due to Tsankov. The results and proofs are stated in
the language of model theory for metric structures.


title: A family of solutions of the Yang-Baxter equation

abstract:
  A new method to construct involutive non-degenerate set-theoretic solutions
$(X^n,r^{(n)})$ of the Yang-Baxter equation from an initial solution $(X,r)$ is
given. Furthermore, the permutation group $\mathcal{G}(X^n,r^{(n)})$ associated
to the solution $(X^n,r^{(n)})$ is isomorphic to a subgroup of
$\mathcal{G}(X,r)$, and in many cases $\mathcal{G}(X^n,r^{(n)})\cong
\mathcal{G}(X,r)$.


title:
The high-energy anomaly in ARPES spectra of the cuprates-many body or
  matrix element effect?

abstract:
  We used polarization-dependent angle-resolved photoemission spectroscopy
(ARPES) to study the high-energy anomaly (HEA) in the dispersion of
Nd2-xCexCuO4, (x=0.123). We have found that at particular photon energies the
anomalous, waterfalllike dispersion gives way to a broad, continuous band. This
suggests that the HEA is a matrix element effect: it arises due to a
suppression of the intensity of the broadened quasi-particle band in a narrow
momentum range. We confirm this interpretation experimentally, by showing that
the HEA appears when the matrix element is suppressed deliberately by changing
the light polarization. Calculations of the matrix element using atomic wave
functions and simulation of the ARPES intensity with one-step model
calculations provide further proof for this scenario. The possibility to detect
the full quasi-particle dispersion further allows us to extract the high-energy
self-energy function near the center and at the edge of the Brillouin zone.


title: Constraining the Origin of Magnetar Flares

abstract:
  Sudden relaxation of the magnetic field in the core of a magnetar produces
mechanical energy primarily in the form of shear waves which propagate to the
surface and enter the magnetosphere as relativistic Alfv\'en waves. Due to a
strong impedance mismatch, shear waves excited in the star suffer many
reflections before exiting the star. If mechanical energy is deposited in the
core and is converted {\em directly} to radiation upon propagation to the
surface, the rise time of the emission is at least seconds to minutes, and
probably minutes to hours for a realistic magnetic field geometry, at odds with
observed rise times of $\lap 10$ ms for both and giant flares. Mechanisms for
both small and giant flares that rely on the sudden relaxation of the magnetic
field of the core are rendered unviable by the impedance mismatch, requiring
the energy that drives these events to be stored in the magnetosphere just
before the flare. ends, unless the waves are quickly damped.


title:
New Formulation of Statistical Mechanics using Thermal Pure Quantum
  States

abstract:
  We formulate statistical mechanics based on a pure quantum state, which we
call a ``thermal pure quantum (TPQ) state''. A single TPQ state gives not only
equilibrium values of mechanical variables, such as magnetization and
correlation functions, but also those of genuine thermodynamic variables and
thermodynamic functions, such as entropy and free energy. Among many possible
TPQ states, we discuss the canonical TPQ state, the TPQ state whose temperature
is specified. % We also propose there are other TPQ states. In the TPQ
formulation of statistical mechanics, thermal fluctuations are completely
included in quantum-mechanical fluctuations. As a consequence, TPQ states have
much larger quantum entanglement than the equilibrium density operators of the
ensemble formulation. We also show that the TPQ formulation is very useful in
practical computations, by applying the formulation to a frustrated
two-dimensional quantum spin system.


title:
Can eccentric debris disks be long-lived? A first numerical
  investigation and application to $\zeta^2$ Reticuli

abstract:
  Imaging of debris disks has found evidence for both eccentric and offset
disks. One hypothesis is that these provide evidence for massive perturbers
that sculpt the observed structures. One such disk was recently observed in the
far-IR by the Herschel Space Observatory around $\zeta^2$ Ret. In contrast with
previously reported systems, the disk is significantly eccentric, and the
system is Gyr-old. We aim to investigate the long-term evolution of eccentric
structures in debris disks caused by a perturber on an eccentric orbit. Both
analytical predictions and numerical N-body simulations are used to investigate
the observable structures that could be produced by eccentric perturbers. The
long-term evolution of the disk geometry is examined, with particular
application to the $\zeta^2$ Ret system. In addition, synthetic images of the
disk are produced for comparison with Herschel observations. We show that an
eccentric companion can produce both the observed offsets and eccentric disks.
Such effects are not immediate and we characterise the timescale required for
the disk to develop to an eccentric state. For the case of $\zeta^2$ Ret, we
place limits on the mass and orbit of the companion required to produce the
observations. Synthetic images show that the pattern observed around $\zeta^2$
Ret can be produced by an eccentric disk seen close to edge-on, and allow us to
bring additional constraints on the disk parameters of our model (disk flux,
extent). We determine that eccentric planets or stellar companions can induce
long-lived eccentric structures in debris disks. Observations of such eccentric
structures provide potential evidence of the presence of such a companion in a
planetary system. We consider the example of $\zeta^2$ Ret, whose observed
eccentric disk can be explained by a distant companion at tens of AU, on an
eccentric orbit ($e_p\gtrsim 0.3$).


title:
Collective-field-corrected strong field approximation for
  laser-irradiated metal clusters

abstract:
  The strong field approximation (SFA) formulated in terms of so-called
"quantum orbits" led to much insight into intense-laser driven ionization
dynamics. In plain SFA, the emitted electron is treated as a free electron in
the laser field alone. However, with improving experimental techniques and more
advanced numerical simulations it becomes more and more obvious that the plain
SFA misses interesting effects even on a qualitative level. Examples are
holographic side lobes, the low-energy structure, radial patterns in
photoelectron spectra at low kinetic energies, and strongly rotated angular
distributions. For this reason increasing effort has been recently devoted to
Coulomb corrections of the SFA. In the current paper, we follow a similar line
but consider ionization of metal clusters. It is known that photoelectrons from
clusters can be much more energetic than those emitted from atoms or small
molecules, especially if the Mie resonance of the expanding cluster is evoked.
We develop a SFA that takes the collective field inside the cluster via the
simple rigid-sphere model into account. Our approach is based on
field-corrected quantum orbits so that the acceleration process (or any other
spectral feature of interest) can be investigated in detail.


title: Object Selection under Team Context

abstract:
  Context-aware database has drawn increasing attention from both industry and
academia recently by taking users' current situation and environment into
consideration. However, most of the literature focus on individual context,
overlooking the team users. In this paper, we investigate how to integrate team
context into database query process to help the users' get top-ranked database
tuples and make the team more competitive. We introduce naive and optimized
query algorithm to select the suitable records and show that they output the
same results while the latter is more computational efficient. Extensive
empirical studies are conducted to evaluate the query approaches and
demonstrate their effectiveness and efficiency.


title:
Chemical freeze-outs of strange and non-strange particles and residual
  chemical non-equilibrium

abstract:
  We propose an elaborate version of the hadron resonance gas model with the
combined treatment of separate chemical freeze-outs for strange and non-strange
hadrons and with an additional \gamma_{s} factor which accounts for the
remaining strange particle non-equilibration. Two sets of chemical freeze-outs
parameters are connected by the conservation laws of entropy, baryonic charge,
isospin projection and strangeness. The developed approach enables us to
perform a high-quality fit of the hadron multiplicity ratios for AGS, SPS and
RHIC energies with total \chi^2/dof \simeq 1.05. A special attention is paid to
a complete description of the Strangeness Horn. A well-known \bar p, \bar
\Lambda and \bar \Xi selective suppression problem is also discussed.


title: Semantic Jira - Semantic Expert Finder in the Bug Tracking Tool Jira

abstract:
  The semantic expert recommender extension for the Jira bug tracking system
semantically searches for similar tickets in Jira and recommends experts and
links to existing organizational (Wiki) knowledge for each ticket. This helps
to avoid redundant work and supports the search and collaboration with experts
in the project management and maintenance phase based on semantically enriched
tickets in Jira.


title:
$E_7 \subset Sp(56,R)$ irrep decompositions of interest for physical
  models

abstract:
  In this note we show how to obtain the projection matrix for the $E_7 \subset
C_{28}$ chain and we tabulate some decompositions of the symplectic algebra
$C_{28}$ representations into irreps of the $E_7$ subalgebra that are important
for various physical models.


title:
On Rigidity of hypersurfaces with constant curvature functions in warped
  product manifolds

abstract:
  In this paper, we first investigate several rigidity problems for
hypersurfaces in the warped product manifolds with constant linear combinations
of higher order mean curvatures as well as "weighted'' mean curvatures, which
extend the work \cite{Mon, Brendle,BE} considering constant mean curvature
functions. Secondly, we obtain the rigidity results for hypersurfaces in the
space forms with constant linear combinations of intrinsic Gauss-Bonnet
curvatures $L_k$. To achieve this, we develop some new kind of Newton-Maclaurin
type inequalities on $L_k$ which may have independent interest.