title: ATLASGAL -- A Galaxy-wide sample of dense filamentary structures

abstract:
  [Abridged] Aims. We study the properties of filamentary structures from the
ATLASGAL survey.
  Methods. We use the DisPerSE algorithm to identify spatially coherent
structures located across the inner-Galaxy (300 < l < 60 and |b| < 1.5).
  Results. We have determined distances, masses and physical sizes for 241 of
the filamentary structures. We find a median distance of 3.8 kpc, a mean mass
of a few 10^3 m_sun, a mean length of ~6pc and a mass-to-length ratio of (M/L)
~200-2000M_sun/ pc. We also find that these filamentary structures are tightly
correlated with the spiral arms in longitude and velocity, and that their
semi-major axis is preferentially aligned parallel to the Galactic mid-plane
and therefore with the direction of large-scale Galactic magnetic field. We
find many examples where the dense filaments identified in ATLASGAL are
associated with larger scale filamentary structures (~100 pc), and argue that
this is likely to be common, and as such these may indicate a connection
between large-scale Galactic dynamics and star formation.
  Conclusions. We have produced a large and Galaxy-wide catalogue of dense
filamentary structures that are representative of a particular size and mass
range not previously well studied in the literature. Analyses of the properties
and distribution of these filaments reveals that they are correlated with the
spiral arms and make a significant contribution to star formation in the
Galaxy. Massive star formation is ongoing within ~20% of the filaments and is
strongly correlated with the filaments with the largest mass-to- length ratios.
The luminosity of the embedded sources has a similar distribution to the
Galactic-wide samples of young massive stars and can therefore be considered to
be representative.


title: The AGI Containment Problem

abstract:
  There is considerable uncertainty about what properties, capabilities and
motivations future AGIs will have. In some plausible scenarios, AGIs may pose
security risks arising from accidents and defects. In order to mitigate these
risks, prudent early AGI research teams will perform significant testing on
their creations before use. Unfortunately, if an AGI has human-level or greater
intelligence, testing itself may not be safe; some natural AGI goal systems
create emergent incentives for AGIs to tamper with their test environments,
make copies of themselves on the internet, or convince developers and operators
to do dangerous things. In this paper, we survey the AGI containment problem -
the question of how to build a container in which tests can be conducted safely
and reliably, even on AGIs with unknown motivations and capabilities that could
be dangerous. We identify requirements for AGI containers, available
mechanisms, and weaknesses that need to be addressed.


title:
Image Quality Assessment for Performance Evaluation of Focus Measure
  Operators

abstract:
  This paper presents the performance evaluation of eight focus measure
operators namely Image CURV (Curvature), GRAE (Gradient Energy), HISE
(Histogram Entropy), LAPM (Modified Laplacian), LAPV (Variance of Laplacian),
LAPD (Diagonal Laplacian), LAP3 (Laplacian in 3D Window) and WAVS (Sum of
Wavelet Coefficients). Statistical matrics such as MSE (Mean Squared Error),
PNSR (Peak Signal to Noise Ratio), SC (Structural Content), NCC (Normalized
Cross Correlation), MD (Maximum Difference) and NAE (Normalized Absolute Error)
are used to evaluate stated focus measures in this research. . FR (Full
Reference) method of the image quality assessment is utilized in this paper.
Results indicate that LAPD method is comparatively better than other seven
focus operators at typical imaging conditions.


title:
Isogeometric analysis for functionally graded microplates based on
  modified couple stress theory

abstract:
  Analysis of static bending, free vibration and buckling behaviours of
functionally graded microplates is investigated in this study. The main idea is
to use the isogeometric analysis in associated with novel four-variable refined
plate theory and quasi-3D theory. More importantly, the modified couple stress
theory with only one material length scale parameter is employed to effectively
capture the size-dependent effects within the microplates. Meanwhile, the
quasi-3D theory which is constructed from a novel seventh-order shear
deformation refined plate theory with four unknowns is able to consider both
shear deformations and thickness stretching effect without requiring shear
correction factors. The NURBS-based isogeometric analysis is integrated to
exactly describe the geometry and approximately calculate the unknown fields
with higher-order derivative and continuity requirements. The convergence and
verification show the validity and efficiency of this proposed computational
approach in comparison with those existing in the literature. It is further
applied to study the static bending, free vibration and buckling responses of
rectangular and circular functionally graded microplates with various types of
boundary conditions. A number of investigations are also conducted to
illustrate the effects of the material length scale, material index, and
length-to-thickness ratios on the responses of the microplates.


title:
Convex Estimation of the $\alpha$-Confidence Reachable Sets of Systems
  with Parametric Uncertainty

abstract:
  Accurately modeling and verifying the correct operation of systems
interacting in dynamic environments is challenging. By leveraging parametric
uncertainty within the model description, one can relax the requirement to
describe exactly the interactions with the environment; however, one must still
guarantee that the model, despite uncertainty, behaves acceptably. This paper
presents a convex optimization method to efficiently compute the set of
configurations of a polynomial dynamical system that are able to safely reach a
user defined target set despite parametric uncertainty in the model. Since
planning in the presence of uncertainty can lead to undesirable conservatives,
this paper computes those trajectories of the uncertain nonlinear systems which
are $\alpha$-probable of reaching the desired configuration. The presented
approach uses the notion of occupation measures to describe the evolution of
trajectories of a nonlinear system with parametric uncertainty as a linear
equation over measures whose supports coincide with the trajectories under
investigation. This linear equation is approximated with vanishing conservatism
using a hierarchy of semidefinite programs each of which is proven to compute
an approximation to the set of initial conditions that are $\alpha$-probable of
reaching the user defined target set safely in spite of uncertainty. The
efficacy of this method is illustrated on four systems with parametric
uncertainty.


title:
Josephson effects in an alternating current biased transition edge
  sensor

abstract:
  We report the experimental evidence of the ac Josephson effect in a
transition edge sensor (TES) operating in a frequency domain multiplexer and
biased by ac voltage at MHz frequencies. The effect is observed by measuring
the non-linear impedance of the sensor. The TES is treated as a weakly linked
superconducting system and within the resistively shunted junction model
framework. We provide a full theoretical explanation of the results by finding
the analytic solution of the non-inertial Langevian equation of the system and
calculating the non-linear response of the detector to a large ac bias current
in the presence of noise.


title: Minimal obstructions for tree-depth: A non-1-unique example

abstract:
  A k-ranking of a graph G is a labeling of the vertices of G with values from
1,...,k such that any path joining two vertices with the same label contains a
vertex having a higher label. The tree-depth of G is the smallest value of k
for which a k-ranking of G exists. The graph G is k-critical if it has
tree-depth k and every proper minor of G has smaller tree-depth.
  As defined in [M. D. Barrus, J. Sinkovic, Uniqueness and minimal obstructions
for tree-depth, Discrete Math 339 (2) (2015) 606-613], a graph G is 1-unique if
for every vertex v in G, there exists an optimal ranking of G in which v is the
unique vertex with label 1. In the above paper and [M. D. Barrus, J. Sinkovic,
Classes of critical graphs for tree-depth, arXiv:1502.0577] the authors showed
that several classes of critical graphs are 1-unique and asked whether all
critical graphs have this property. We answer in the negative by demonstrating
an infinite family of graphs which are critical but not 1-unique.


title:
A new family of transportation costs with applications to
  reaction-diffusion and parabolic equations with boundary conditions

abstract:
  This paper introduces a family of transportation costs between non-negative
measures. This family is used to obtain parabolic and reaction-diffusion
equations with drift, subject to Dirichlet boundary condition, as the gradient
flow of the entropy functional
$\int_{\Omega}\rho\log\rho+V\rho+1\hspace{1mm}dx$. In 2010, Alessio Figalli and
Nicola Gigli introduced a transportation cost that can be used to obtain
parabolic equations with drift subject to Dirichlet boundary condition.
However, the drift and the boundary condition are coupled in their work. The
costs in this paper allow the drift and the boundary condition to be detached.


title:
pH Prediction by Artificial Neural Networks for the Drinking Water of
  the Distribution System of Hyderabad City

abstract:
  In this research, feedforward ANN (Artificial Neural Network) model is
developed and validated for predicting the pH at 10 different locations of the
distribution system of drinking water of Hyderabad city. The developed model is
MLP (Multilayer Perceptron) with back propagation algorithm.The data for the
training and testing of the model are collected through an experimental
analysis on weekly basis in a routine examination for maintaining the quality
of drinking water in the city. 17 parameters are taken into consideration
including pH. These all parameters are taken as input variables for the model
and then pH is predicted for 03 phases;raw water of river Indus,treated water
in the treatment plants and then treated water in the distribution system of
drinking water. The training and testing results of this model reveal that MLP
neural networks are exceedingly extrapolative for predicting the pH of river
water, untreated and treated water at all locations of the distribution system
of drinking water of Hyderabad city. The optimum input and output weights are
generated with minimum MSE (Mean Square Error) < 5%.Experimental, predicted and
tested values of pH are plotted and the effectiveness of the model is
determined by calculating the coefficient of correlation (R2=0.999) of trained
and tested results.


title:
Development of TES-based detectors array for the X-ray Integral Field
  Unit (X-IFU) on the future x-ray observatory ATHENA

abstract:
  We are developing transition-edge sensor (TES)-based microcalorimeters for
the X-ray Integral Field Unit (XIFU) of the future European X-Ray Observatory
Athena. The microcalorimeters are based on TiAu TESs coupled to 250{\mu}m
squared, AuBi absorbers. We designed and fabricated devices with different
contact geometries between the absorber and the TES to optimise the detector
performance and with different wiring topology to mitigate the self-magnetic
field. The design is tailored to optimise the performance under Frequency
Domain Multiplexing. In this paper we review the main design feature of the
pixels array and we report on the performance of the 18 channels, 2-5MHz
frequency domain multiplexer that will be used to characterised the detector
array.


title: Scalability Model Based on the Concept of Granularity

abstract:
  In the recent years it can be observed increasing popularity of parallel
processing using multi-core processors, local clusters, GPU and others.
Moreover, currently one of the main requirements the IT users is the reduction
of maintaining cost of the computer infrastructure. It causes that the
performance evaluation of the parallel applications becomes one of the most
important problem. Then obtained results allows efficient use of available
resources. In traditional methods of performance evaluation the results are
based on wall-clock time measurements. This approach requires consecutive
application executions and includes a time-consuming data analysis. In the
paper an alternative approach is proposed. The decomposition of parallel
application execution time onto computation time and overheads related to
parallel execution is use to calculate the granularity of application and then
determine its efficiency. Finally the application scalability can be evaluates.


title:
Path Laplacian operators and superdiffusive processes on graphs. I.
  One-dimensional case

abstract:
  We consider a generalization of the diffusion equation on graphs. This
generalized diffusion equation gives rise to both normal and superdiffusive
processes on infinite one-dimensional graphs. The generalization is based on
the $k$-path Laplacian operators $L_{k}$, which account for the hop of a
diffusive particle to non-nearest neighbours in a graph. We first prove that
the $k$-path Laplacian operators are self-adjoint. Then, we study the
transformed $k$-path Laplacian operators using Laplace, factorial and Mellin
transforms. We prove that the generalized diffusion equation using the Laplace-
and factorial-transformed operators always produce normal diffusive processes
independently of the parameters of the transforms. More importantly, the
generalized diffusion equation using the Mellin-transformed $k$-path Laplacians
$\sum_{k=1}^{\infty}k^{-s}L_{k}$ produces superdiffusive processes when
$1<s<3$.


title:
Parametric Study of Nonlinear Adaptive Cruise Control for a Road Vehicle
  Model by MPC

abstract:
  MPC (Model Predictive Control) techniques, with constraints, are applied to a
nonlinear vehicle model for the development of an ACC (Adaptive Cruise Control)
system for transitional manoeuvres. The dynamic model of the vehicle is
developed in the continuous-time domain and captures the real dynamics of the
sub-vehicle models for steady-state and transient operations. A parametric
study for the MPC method is conducted to analyse the response of the ACC
vehicle for critical manoeuvres. The simulation results show the significant
sensitivity of the response of the vehicle model with ACC to controller
parameter and comparisons are made with a previous study. Furthermore, the
approach adopted in this work is believed to reflect the control actions taken
by a real vehicle.


title: SAM: Support Vector Machine Based Active Queue Management

abstract:
  Recent years have seen an increasing interest in the design of AQM (Active
Queue Management) controllers. The purpose of these controllers is to manage
the network congestion under varying loads, link delays and bandwidth. In this
paper, a new AQM controller is proposed which is trained by using the SVM
(Support Vector Machine) with the RBF (Radial Basis Function) kernal. The
proposed controller is called the support vector based AQM (SAM) controller.
The performance of the proposed controller has been compared with three
conventional AQM controllers, namely the Random Early Detection, Blue and
Proportional Plus Integral Controller. The preliminary simulation studies show
that the performance of the proposed controller is comparable to the
conventional controllers. However, the proposed controller is more efficient in
controlling the queue size than the conventional controllers.


title: Channel Equalization Using Multilayer Perceptron Networks

abstract:
  In most digital communication systems, bandwidth limited channel along with
multipath propagation causes ISI (Inter Symbol Interference) to occur. This
phenomenon causes distortion of the given transmitted symbol due to other
transmitted symbols. With the help of equalization ISI can be reduced. This
paper presents a solution to the ISI problem by performing blind equalization
using ANN (Artificial Neural Networks). The simulated network is a multilayer
feedforward Perceptron ANN, which has been trained by utilizing the error
back-propagation algorithm. The weights of the network are updated in
accordance with training of the network. This paper presents a very effective
method for blind channel equalization, being more efficient than the
pre-existing algorithms. The obtained results show a visible reduction in the
noise content.


title:
Relaxation-free and inertial switching in synthetic antiferromagnets
  subject to super-resonant excitation

abstract:
  Applications of magnetic memory devices greatly benefit from ultra-fast,
low-power switching. Here we propose how this can be achieved efficiently in a
nano-sized synthetic antiferromagnet by using perpendicular-to-the-plane
picosecond-range magnetic field pulses. Our detailed micromagnetic simulations,
supported by analytical results, yield the parameter space where inertial
switching and relaxation-free switching can be achieved in the system. We
furthermore discuss the advantages of dynamic switching in synthetic
antiferromagnets and, specifically, their relatively low-power switching as
compared to that in single ferromagnetic particles. Finally, we show how
excitation of spin-waves in the system can be used to significantly reduce the
post-switching spin oscillations for practical device geometries.


title:
New method of techno-economic analysis of radiation impact for nuclear
  industry

abstract:
  Bearing in mind physical and social aspects, health issues connected with
operation of nuclear facilities are under continuous control of national and
international regulatory institutions. The main purpose of doing so is to
reduce risk of ionizing radiation on human health. Under standard operation of
any controlled nuclear facility, direct injuries connected by nonstochastic
effects of ionizing radiation, such as Acute Radiation Syndrome (ARS) are
theoretically possible only if health and safety measures are violated. On the
other hand, the stochastic effect of radiation may cause tumors with increasing
probability of received radioactive dose. Nuclear facilities such as nuclear
power plants use certain formulas to calculate the cost of potential health
damage caused by ionizing radiation. These formulas are derived according to
Linear No-Threshold Relationship between the dose and cancer risk. However,
this Linear No-Threshold relationship (LNT) is becoming debatable with new
radiological research. Therefore, a new methodology of cost estimation of
health risks induced by ionizing radiation is introduced in this paper.


title: On the Conditional Distribution of the Multivariate $t$ Distribution

abstract:
  As alternatives to the normal distributions, $t$ distributions are widely
applied in robust analysis for data with outliers or heavy tails. The
properties of the multivariate $t$ distribution are well documented in Kotz and
Nadarajah's book, which, however, states a wrong conclusion about the
conditional distribution of the multivariate $t$ distribution. Previous
literature has recognized that the conditional distribution of the multivariate
$t$ distribution also follows the multivariate $t$ distribution. We provide an
intuitive proof without directly manipulating the complicated density function
of the multivariate $t$ distribution.


title: Reasoning About Pragmatics with Neural Listeners and Speakers

abstract:
  We present a model for pragmatically describing scenes, in which contrastive
behavior results from a combination of inference-driven pragmatics and learned
semantics. Like previous learned approaches to language generation, our model
uses a simple feature-driven architecture (here a pair of neural "listener" and
"speaker" models) to ground language in the world. Like inference-driven
approaches to pragmatics, our model actively reasons about listener behavior
when selecting utterances. For training, our approach requires only ordinary
captions, annotated _without_ demonstration of the pragmatic behavior the model
ultimately exhibits. In human evaluations on a referring expression game, our
approach succeeds 81% of the time, compared to a 69% success rate using
existing techniques.


title: Exploring the Origin and Dynamics of Solar Magnetic Fields

abstract:
  The Sun is a magnetically active star and is the source of the solar wind,
electromagnetic radiation and energetic particles which affect the heliosphere
and the Earths atmosphere. The magnetic field of the Sun is responsible for
most of the dynamic activity of the Sun. This thesis research seeks to
understand solar magnetic field generation and the role that magnetic fields
play in the dynamics of the solar atmosphere. Specifically, this thesis focuses
on two themes: in the first part, we study the origin and behaviour of solar
magnetic fields using magnetohydrodynamic dynamo theory and modelling, and in
the second part, utilizing observations and data analysis we study two major
problems in solar physics, namely, the coronal heating problem and initiation
mechanisms of solar flares.


title:
An Empirical Study of Irregular AG Block Turbo Codes over Fading
  Channels

abstract:
  This study will present the design, construction and implementation of
Algebraic Geometric Irregular Block Turbo Codes (AGIBTCs). Furthermore, we will
evaluate its performance over fast fading channels using different modulation
schemes (BPSK, QPSK, 16QAM and 64QAM). The idea behind the design of AGIBTC is
to overcome the high system complexity of Algebraic Geometric Block Turbo Codes
(AGBTCs) while maintaining a high Bit-Error Rate (BER) performance. This design
is inspired by the idea of unequal protection of information symbols which is
the core of IBTCs. Our experiments conducted over the worst case of fading
channels which is the fast fading channels; and this is done in order to show
the magnitude of gain in BER or the reduction in system complexity that can be
achieved by this design. Our experiments shows that despite a very slight
negative gain over BPSK and QPSK modulation schemes the system complexity is
significantly reduced. However, when applying higher modulation schemes a gain
in both BER and system complexity are achieved.


title:
A Statistical Block Fading Channel Model for Multiuser Massive MIMO
  System

abstract:
  This paper presents a statistical block fading channel model for multiuser
massive MIMO system. The proposed channel model is evolved from correlation
based stochastic channel model (CBSCM) but in addition to the properties of
CBSCM, it has capability of capturing channel variations along time or
frequency and along space simultaneously. It has a simplified analytical
expression, still being able to simulate underlying physical phenomena which
otherwise need a complex geometry based stochastic channel model (GBSCM). The
channel model is verified with reported measurement data of channel for massive
MIMO. Spatial determinism in channel, the basic cause of unfavorable
propagation, is modeled into controlling parameters of channel model. Channel
model uses only three controlling parameters; one parameter describes variation
in channel along resource block (along time or frequency) and remaining two
parameters describe spatial variation in channel. Modeling of simultaneous
variation along time and space belongs to a very common scenario where mobility
of mobile terminal and angular power distribution at base station receiver, are
key parameters. Additionally, simulation results reveal the hidden advantages
of spatial determinism in channel for multiuser massive MIMO.


title: Sharp uncertainty relations for number and angle

abstract:
  We study uncertainty relations for pairs of conjugate variables like number
and angle, of which one takes integer values and the other takes values on the
unit circle. The translation symmetry of the problem in either variable implies
that measurement uncertainty and preparation uncertainty coincide
quantitatively, and the bounds depend only on the choice of two metrics used to
quantify the difference of number and angle outputs, respectively. For each
type of observable we discuss two natural choices of metric, and discuss the
resulting optimal bounds with both numerical and analytic methods. We also
develop some simple and explicit (albeit not sharp) lower bounds, using an
apparently new method for obtaining certified lower bounds to ground state
problems.


title:
Design of a plasmonic-organic hybrid slot waveguide integrated with a
  bowtie-antenna for terahertz wave detection

abstract:
  Electromagnetic (EM) wave detection over a large spectrum has recently
attracted significant amount of attention. Traditional electronic EM wave
sensors use large metallic probes which distort the field to be measured and
also have strict limitations on the detectable RF bandwidth. To address these
problems, integrated photonic EM wave sensors have been developed to provide
high sensitivity and broad bandwidth. Previously we demonstrated a compact,
broadband, and sensitive integrated photonic EM wave sensor, consisting of an
organic electro-optic (EO) polymer refilled silicon slot photonic crystal
waveguide (PCW) modulator integrated with a gold bowtie antenna, to detect the
X band of the electromagnetic spectrum. However, due to the relative large RC
constant of the silicon PCW, such EM wave sensors can only work up to tens of
GHz. In this work, we present a detailed design and discussion of a new
generation of EM wave sensors based on EO polymer refilled plasmonic slot
waveguides in conjunction with bowtie antennas to cover a wider electromagnetic
spectrum from 1 GHz up to 10THz, including the range of microwave, millimeter
wave and even terahertz waves. This antenna-coupled plasmonic-organic hybrid
(POH) structure is designed to provide an ultra-small RC constant, a large
overlap between plasmonic mode and RF field, and strong electric field
enhancement, as well as negligible field perturbation. A taper is designed to
bridge silicon strip waveguide to plasmonic slot waveguide. Simulation results
show that our device can have an EM wave sensing ability up to 10 THz. To the
best of our knowledge, this is the first POH device for photonic terahertz wave
detection.


title:
Continuity bounds for information characteristics of quantum channels
  depending on input dimension

abstract:
  We show how to use properties of the quantum conditional mutual information
to obtain continuity bounds for information characteristics of quantum channels
depending on their input dimension.
  First we prove tight estimates for variation of the output Holevo quantity
with respect to simultaneous variations of a channel and of an input ensemble.
  Then we obtain tight continuity bounds for output conditional mutual
information for a single channel and for $n$ copies of a channel.
  As a result tight and close-to-tight continuity bounds for basic capacities
of quantum channels depending on the input dimension are obtained. They
complement the Leung-Smith continuity bounds depending on the output dimension.


title:
Implicit operators for networked mechanical and thermal systems with
  integer-order components

abstract:
  Complex systems are composed of a large number of simple components connected
to each other in the form of a network. It is shown that, for some network
configurations, the equivalent dynamic behavior of the system is governed by an
implicit integro-differential operator even though the individual components
themselves satisfy equations that use explicit operators of integer order. The
networks considered here are infinite trees and ladders, and each is composed
only of two types of integer-order components with potential-driven flows that
are repeated ad infinitum. In special cases the equivalent operator for the
system is a fractional-order derivative, but in general it is implicit and can
only be expressed as a solution of an operator equation. These implicit
operators, which are a generalization of fractional-order derivatives, play an
important role in the analysis and modeling of complex systems.


title: Online EM for Functional Data

abstract:
  A novel approach to perform unsupervised sequential learning for functional
data is proposed. Our goal is to extract reference shapes (referred to as
templates) from noisy, deformed and censored realizations of curves and images.
Our model generalizes the Bayesian dense deformable template model
(Allassonni\`ere et al., 2007), a hierarchical model in which the template is
the function to be estimated and the deformation is a nuisance, assumed to be
random with a known prior distribution. The templates are estimated using a
Monte Carlo version of the online Expectation-Maximization algorithm, extending
the work from Capp\'e and Moulines (2009). Our sequential inference framework
is significantly more computationally efficient than equivalent batch learning
algorithms, especially when the missing data is high-dimensional. Some
numerical illustrations on curve registration problem and templates extraction
from images are provided to support our findings.


title:
Stability of equilibrium shapes in some free boundary problems involving
  fluids

abstract:
  In this paper the motion of two-phase, incompressible, viscous fluids with
surface tension is investigated. Three cases are considered: (1) the case of
heat-conducting fluids, (2) the case of isothermal fluids, and (3) the case of
Stokes flows. In all three situations, the equilibrium states in the absence of
outer forces are characterized and their stability properties are analyzed. It
is shown that the equilibrium states correspond to the critical points of a
natural physical or geometric functional (entropy, available energy, surface
area) constrained by the pertinent conserved quantities (total energy, phase
volumes). Moreover, it is shown that solutions which do not develop
singularities exist globally and converge to an equilibrium state.


title: Spatio-temporal Modelling of Temperature Fields in the Pacific Northwest

abstract:
  The importance of modelling temperature fields goes beyond the need to
understand a region's climate and serves too as a starting point for
understanding their socioeconomic, and health consequences. The topography of
the study region contributes much to the complexity of modelling these fields
and demands flexible spatio-temporal models that are able to handle
nonstationarity and changes in trend. In this paper, we develop a flexible
stochastic spatio-temporal model for daily temperatures in the Pacific
Northwest, and describe a methodology for performing Bayesian spatial
prediction. A novel aspect of this model, an extension of the spatio-temporal
model proposed in Le and Zidek (1992), is its incorporation of site-specific
features of a spatio-temporal field in its spatio-temporal mean. Due to the
often surprising Pacific Northwestern weather, the analysis reported in the
paper shows the need to incorporate spatio-temporal interactions in that mean
in order to understand the rapid changes in temperature observed in nearby
locations and to get approximately stationary residuals for higher level
analysis. No structure is assumed for the spatial covariance matrix of these
residuals, thus allowing the model to capture any nonstationary spatial
structures remaining in those residuals.


title: Sharply 2-transitive groups in characteristic 0

abstract:
  We construct sharply 2-transitive groups of characteristic 0 without
non-trivial abelian normal subgroup. These groups act sharply 2-trnaisitvely by
conjugation on their involutions. This answers a longstanding open question.


title: Hyperbolic Weyl point in reciprocal chiral metamaterial

abstract:
  We report the existence of Weyl points in a class of non-central symmetric
metamaterials, which has time reversal symmetry, but does not have inversion
symmetry due to chiral coupling between electric and magnetic fields. This
class of metamaterial exhibits either type-I or type-II Weyl points depending
on its non-local response. We also provide a physical realization of such
metamaterial consisting of an array of metal wires in the shape of elliptical
helixes which exhibits type-II Weyl points.


title: AsicBoost - A Speedup for Bitcoin Mining

abstract:
  AsicBoost is a method to speed up Bitcoin mining by a factor of approximately
20%. The performance gain is achieved through a high-level optimization of the
Bitcoin mining algorithm which allows for drastic reduction in gate count on
the mining chip. AsicBoost is applicable to all types of mining hardware and
chip designs. This paper presents the idea behind the method and describes the
information flow in implementations of AsicBoost.


title: Throughput-Optimal Broadcast in Wireless Networks with Dynamic Topology

abstract:
  We consider the problem of throughput-optimal broadcast- ing in time-varying
wireless networks, whose underlying topology is restricted to Directed Acyclic
Graphs (DAG). Previous broadcast algorithms route packets along spanning trees.
In large networks with time-varying connectivities, these trees are difficult
to compute and maintain. In this paper we propose a new online
throughput-optimal broadcast algorithm which makes packet-by-packet scheduling
and routing decisions, obviating the need for maintaining any global
topological structures, such as spanning-trees. Our algorithm relies on
system-state information for making transmission decisions and hence, may be
thought of as a generalization of the well-known back-pressure algorithm which
makes point-to-point unicast transmission decisions based on queue-length
information, without requiring knowledge of end-to-end paths. Technically, the
back-pressure algorithm is derived by stochastically stabilizing the
network-queues. However, because of packet-duplications associated with
broadcast, the work-conservation principle is violated and queuing processes
are difficult to define in the broadcast problem. To address this fundamental
issue, we identify certain state-variables which behave like virtual queues in
the broadcast setting. By stochastically stabilizing these virtual queues, we
devise a throughput-optimal broadcast policy. We also derive new
characterizations of the broadcast-capacity of time-varying wireless DAGs and
derive an efficient algorithm to compute the capacity exactly under certain
assumptions of interference model, and a poly-time approximation algorithm for
computing the capacity under less restrictive assumptions.


title:
Symmetric (not Complete Intersection) Semigroups Generated by Five
  Elements

abstract:
  We consider symmetric (not complete intersection) numerical semigroups S_5,
generated by five elements, and derive inequalities for degrees of syzygies of
S_5 and find the lower bound F_5 for their Frobenius numbers. We study a
special case W_5 of such semigroups, which satisfy the Watanabe Lemma, and show
that the lower bound F_{5w} for the Frobenius number of the semigroup W_5 is
stronger than F_5.


title: Universal Deformation Rings and Quivers of Finite Representation Type

abstract:
  Let k be a field of arbitrary characteristic and let Q be a quiver of finite
representation type. In this paper we prove that if M is an indecomposable
kQ-module then the universal deformation ring of M over kQ is isomorphic to k.


title:
New Insights on Stacking Fault Behavior in Twin Induced Plasticity from
  Meta-Atom Molecular Dynamics Simulations

abstract:
  There is growing interest in promoting deformation twinning for plasticity in
advanced materials, as highly organized twin boundaries are beneficial to
better strength-ductility combination in contrast to disordered grain
boundaries. Twinning deformation typically involves the kinetics of stacking
faults, its interaction with dislocations, and dislocation - twin boundary
interactions. While the latter has been intensively investigated, the dynamics
of stacking faults has been less known. In this work, we report several new
insights on the stacking fault behavior in twin induced plasticity from our
meta-atom molecular dynamics simulation: The stacking fault interactions are
dominated by dislocation reactions taking place spontaneously, different from
the proposed mechanism in literatures; The competition among generating a
single stacking fault, a twinning partial and a trailing partial dislocation is
dependent on a unique parameter, i.e. stacking fault energy, which in turn
determines deformation twinning behaviors. The complex twin-slip and
twin-dislocation interactions demonstrate the dual role of deformation twins as
both dislocation barrier and storage, potentially contributing to the high
strength and ductility of advanced materials like TWIP steels where deformation
twinning dominated plasticity accounts for the superb strength-ductility
combination.


title: Rectifications of Convex Polyhedra

abstract:
  A convex polyhedron, that is, a compact convex subset of $\mathbb{R}^3$ which
is the intersection of finitely many closed half-spaces, can be rectified by
taking the convex hull of the midpoints of the edges of the polyhedron. We
derive expressions for the side lengths and areas of rectifications of regular
polygons in plane, and use these results to compute surface areas and volumes
of various convex polyhedra. We introduce rectification sequences and show that
there are exactly two disjoint pure rectification sequences generated by the
platonic solids.


title: A note on the spectral mapping theorem of quantum walk models

abstract:
  We discuss the description of eigenspace of a quantum walk model $U$ with an
associating linear operator $T$ in abstract settings of quantum walk including
the Szegedy walk on graphs. In particular, we provide the spectral mapping
theorem of $U$ without the spectral decomposition of $T$. Arguments in this
direction reveal the eigenspaces of $U$ characterized by the generalized
kernels of linear operators given by $T$.

categories: math-ph math.FA math.MP math.SP quant-ph


title:
Elevated Multiplexing and Signal Space Partitioning in the 2 User MIMO
  IC with Partial CSIT

abstract:
  The $2$ user MIMO interference channel with arbitrary antenna configurations
is studied under arbitrary levels of partial CSIT for each of the channels, to
find the degrees of freedom (DoF) achievable by either user while the other
user achieves his full interference-free DoF. The goal is to gain new insights
due to the inclusion of MIMO (multiple antennas at both transmitters and
receivers) into the signal space partitioning schemes associated with partial
CSIT. An interesting idea that emerges from this study is "elevated
multiplexing" where the signals are split into streams and transmitted from
separate antennas at elevated power levels, which allows these signals to be
jointly decoded at one receiver which has fewer spatial dimensions with lower
interference floors, while another receiver is simultaneously able to
separately decode these signals with a higher interference floor but across a
greater number of spatial dimensions. Remarkably, we find that there is a DoF
benefit from increasing the number of antennas at a transmitter even if that
transmitter already has more antennas than its desired receiver and has no
CSIT.


title:
A new approach to constructing efficient stiffly accurate exponential
  propagation iterative methods of Runge-Kutta type (EPIRK)

abstract:
  The structural flexibility of the exponential propagation iterative methods
of Runge-Kutta type (EPIRK) enables construction of particularly efficient
exponential time integrators. While the EPIRK methods have been shown to
perform well on stiff problems, all of the schemes proposed up to now have been
derived using classical order conditions. In this paper we extend the stiff
order conditions and the convergence theory developed for the exponential
Rosenbrock methods to the EPIRK integrators. We derive stiff order conditions
for the EPIRK methods and develop algorithms to solve them to obtain specific
schemes. Moreover, we propose a new approach to constructing particularly
efficient EPIRK integrators that are optimized to work with an adaptive Krylov
algorithm. We use a set of numerical examples to illustrate the computational
advantages that the newly constructed EPIRK methods offer compared to
previously proposed exponential integrators.


title: Representation varieties detect essential surfaces

abstract:
  Extending Culler-Shalen theory, Hara and the second author presented a way to
construct certain kinds of branched surfaces in a $3$-manifold from an ideal
point of a curve in the $\operatorname{SL}_n$-character variety. There exists
an essential surface in some $3$-manifold known to be not detected in the
classical $\operatorname{SL}_2$-theory. We prove that every connected essential
surface in a $3$-manifold is given by an ideal point of a rational curve in the
$\operatorname{SL}_n$-character variety for some $n$.


title:
Enhanced third-order and fifth-order Kerr nonlinearities in a cold
  atomic system via Rydberg-Rydberg interaction

abstract:
  We investigate the optical Kerr nonlinearities of an ensemble of cold Rydberg
atoms under the condition of electromagnetically induced transparency (EIT). By
using an approach beyond mean-field theory, we show that the system possesses
not only enhanced third-order nonlinear optical susceptibility, but also giant
fifth-order nonlinear optical susceptibility, which has a cubic dependence on
atomic density. Our results demonstrate that both the third-order and the
fifth-order nonlinear optical susceptibilities consist of two parts,
contributed respectively by photon-atom interaction and Rydberg-Rydberg
interaction. The Kerr nonlinearity induced by the Rydberg-Rydberg interaction
plays a leading role at high atomic density. We find that the fifth-order
nonlinear optical susceptibility in the Rydberg-EIT system may be five orders
of magnitude larger than that obtained in traditional EIT systems. The results
obtained may have promising applications in light and quantum information
processing and transmission at weak-light level.


title:
Prediction of a new ground state of superhard compound B6O at ambient
  conditions

abstract:
  Boron suboxide B6O, the hardest known oxide, has an R-3m crystal structure
({\alpha}-B6O) that can be described as an oxygen-intercalated structure of
{\alpha}-boron, or, equivalently, as a cubic close packing of B12 icosahedra
with two oxygen atoms occupying all octahedral voids in it. Here we show a new
ground state of this compound at ambient conditions, Cmcm-B6O (\b{eta}-B6O),
which in all quantum-mechanical treatments that we tested (GGA, LDA, and hybrid
functional HSE06) comes out to be slightly but consistently more stable.
Increasing pressure and temperature further stabilize it with respect to the
known {\alpha}-B6O structure. \b{eta}-B6O also has a slightly higher hardness
and may be synthesized using different experimental protocols. We suggest that
\b{eta}-B6O is present in mixture with {\alpha}-B6O, and its presence accounts
for previously unexplained bands in the experimental Raman spectrum.


title:
A note on periodicity of long-term variations of optical continuum in
  active galactic nuclei

abstract:
  Graham et al. found a sample of active galactic nuclei (AGNs) and quasars
from the Catalina Real-time Transient Survey (CRTS) that have long-term
periodic variations in optical continuum, the nature of the periodicity remains
uncertain. We investigate the periodic variability characteristics of the
sample by testing the relations of the observed variability periods with AGN
optical luminosity, black hole mass and accretion rates, and find no
significant correlations. We also test the observed periods in several
different aspects related to accretion disks surrounding single black holes,
such as the Keplerian rotational periods of 5100~\AA\ photon-emission regions
and self-gravity dominated regions and the precessing period of warped disks.
These tests shed new lights on understanding AGN variability in general. Under
the assumption that the periodic behavior is associated with SMBHB systems in
particular, we compare the separations ($\mathscr{D}_{\bullet}$) against
characteristic radii of broad-line regions ($R_{\rm BLR}$) of the binaries and
find $\mathscr{D}_{\bullet}$$\approx$ 0.05 $R_{\rm BLR}$. This interestingly
implies that these binaries have only circumbinary BLRs.


title:
Statistical QoS Analysis of Full Duplex and Half Duplex Heterogeneous
  Cellular Networks

abstract:
  In this paper, statistical Quality of Service provisioning in next generation
heterogeneous mobile cellular networks is investigated. To this aim, any active
entity of the cellular network is regarded as a queuing system, whose
statistical QoS requirements depend on the specific application. In this
context, by quantifying the performance in terms of effective capacity, we
introduce a lower bound for the system performance that facilitates an
efficient analysis. We exploit this analytical framework to give insights about
the possible improvement of the statistical QoS experienced by the users if the
current heterogeneous cellular network architecture migrates from a Half Duplex
to a Full Duplex mode of operation. Numerical results and analysis are
provided, where the network is modeled as a Mat\'ern point processes with a
hard core distance. The results demonstrate the accuracy and computational
efficiency of the proposed scheme, especially in large scale wireless systems.


title:
RAdNet-VE: An Interest-Centric Mobile Ad Hoc Network for Vehicular
  Environments

abstract:
  In this study, we propose a variation of the RAdNet for vehicular
environments (RAdNet-VE). The proposed scheme extends the message header,
mechanism for registering interest, and message forwarding mechanism of RAdNet.
To obtain results, we performed simulation experiments involving two use
scenarios and communication protocols developed from the Veins framework. Based
on results obtained from these experiments, we compare the performance of
RAdNet-VE against that of RAdNet, a basic content-centric network (CCN) using
reactive data routing, (CCN$_R$), and a basic CCN using proactive data routing,
CCN$_P$. These CCNs provide non-cacheable data services. Moreover, the
communication radio standards adopted in the scenarios 1 and 2 were
respectively IEEE 802.11n and IEEE 802.11p. The results shown that the
performance of the RAdNet-VE was superior to than those of RAdNet, CCN$_R$ and
CCN$_P$. In this sense, RAdNet-VE protocol (RVEP) presented low communication
latencies among nodes of just 20.4ms (scenario 1) and 2.87 ms (scenario 2). Our
protocol also presented high data delivery rates, i.e, 83.05\% (scenario 1) and
88.05\% (scenario 2). Based on these and other results presented in this study,
we argue that RAdNet-VE is a feasible alternative to CCNs as
information-centric network (ICN) model for VANET, because the RVEP satisfies
all of the necessary communication requirements.


title:
Preferential Attachment Model with Degree Bound and its Application to
  Key Predistribution in WSN

abstract:
  Preferential attachment models have been widely studied in complex networks,
because they can explain the formation of many networks like social networks,
citation networks, power grids, and biological networks, to name a few.
Motivated by the application of key predistribution in wireless sensor networks
(WSN), we initiate the study of preferential attachment with degree bound.
  Our paper has two important contributions to two different areas. The first
is a contribution in the study of complex networks. We propose preferential
attachment model with degree bound for the first time. In the normal
preferential attachment model, the degree distribution follows a power law,
with many nodes of low degree and a few nodes of high degree. In our scheme,
the nodes can have a maximum degree $d_{\max}$, where $d_{\max}$ is an integer
chosen according to the application. The second is in the security of wireless
sensor networks. We propose a new key predistribution scheme based on the above
model. The important features of this model are that the network is fully
connected, it has fewer keys, has larger size of the giant component and lower
average path length compared with traditional key predistribution schemes and
comparable resilience to random node attacks.
  We argue that in many networks like key predistribution and Internet of
Things, having nodes of very high degree will be a bottle-neck in
communication. Thus, studying preferential attachment model with degree bound
will open up new directions in the study of complex networks, and will have
many applications in real world scenarios.


title:
Quantifying Nonclassicality of Correlations based on the Concept of
  Nondisruptive Local State Identification

abstract:
  A bipartite state is classical with respect to party $A$ if and only if party
$A$ can perform nondisruptive local state identification (NDLID) by a
projective measurement. Motivated by this we introduce a class of quantum
correlation measures for an arbitrary bipartite state. The measures utilize the
general Schatten $p$-norm to quantify the amount of departure from the
necessary and sufficient condition of classicality of correlations provided by
the concept of NDLID. We show that for the case of Hilbert-Schmidt norm, i.e.
$p=2$, a closed formula is available for an arbitrary bipartite state. The
reliability of the proposed measures is checked from the information theoretic
perspective. Also, the monotonicity behavior of these measures under LOCC is
exemplified. The results reveal that for the general pure bipartite states
these measures have an upper bound which is an entanglement monotone in its own
right. This enables us to introduce a new measure of entanglement, for a
general bipartite state, by convex roof construction. Some examples and
comparison with other quantum correlation measures are also provided.


title:
The isoperimetric problem in the plane with the sum of two Gaussian
  densities

abstract:
  We consider the isoperimetric problem for the sum of two Gaussian densities
in the line and the plane. We prove that the double Gaussian isoperimetric
regions in the line are rays and that if the double Gaussian isoperimetric
regions in the plane are half-spaces, then they must be bounded by vertical
lines.


title: Collision between chemically-driven self-propelled drops

abstract:
  We consider analytically and numerically head-on collision between two
self-propelled drops. Each drop is driven by chemical reactions that produce or
consume the concentration isotropically. The isotropic distribution of the
concentration field is destabilized by motion of the drop which is itself made
by Marangoni flow from concentration-dependent surface tension. This
symmetry-breaking self-propulsion is distinct from other self-propulsion
mechanisms due to the intrinsic polarity such as squirmers and self-phoretic
motion; there is a bifurcation point below which the drop is stationary and
above which it moves spontaneously. When two drops moving along the same axis
with opposite direction, the interactions arise both from hydrodynamics and
concentration overlap. We found that two drops exhibit either elastic collision
or fusion depending on the distance from the bifurcation point controlled, for
instance, by viscosity. The elastic collision results from the balance between
dissipation and energy injection by chemical reactions. We derive the reduced
equations for the collision between two drops and analyze the contributions
from the two interactions. The concentration-mediated interaction is found to
dominate the hydrodynamic interaction.

categories: physics.flu-dyn cond-mat.soft nlin.PS physics.bio-ph


title: Two Dimensional Angle of Arrival Estimation

abstract:
  We present a new method for the estimation of two dimensional (2D) angles of
arrival (AOAs), namely, azimuth and incidence angles of multiple narrowband
signals of same frequency in the far field of antenna array.


title:
Non-spherically symmetric black string perturbations in the large D
  limit

abstract:
  We consider non-spherically symmetric perturbations of the uncharged black
string/flat black brane in the large dimension (D) limit of general relativity.
We express the perturbations in a simplified form using variables introduced by
Ishibashi and Kodama. We apply the large D limit to the equations, and show
that this leads to decoupling of the equations in the near-horizon and
asymptotic regions. It also enables use of matched asymptotic expansions to
obtain approximate analytical solutions and to analyze stability of the black
string/brane. For a large class of non-spherically symmetric perturbations, we
prove that there are no instabilities in the large D limit. For the rest, we
provide additional matching arguments that indicate that the black string/brane
is stable. In the \emph{static} limit, we show that for \emph{all}
non-spherically symmetric perturbations, there is no instability. This is proof
that the Gross-Perry-Yaffe mode for semiclassical black hole perturbations is
the unique unstable mode even in the large D limit. This work is also a direct
analytical indication that the only instability of the black string is the
Gregory-Laflamme instability.


title: Getting rich quick with the Axiom of Choice

abstract:
  This paper proposes new get-rich-quick schemes that involve trading in a
financial security with a non-degenerate price path. For simplicity the
interest rate is assumed zero. If the price path is assumed continuous, the
trader can become infinitely rich immediately after it becomes non-constant (if
it ever does). If it is assumed positive, he can become infinitely rich
immediately after reaching a point in time such that the variation of the log
price is infinite in any right neighbourhood of that point (whereas reaching a
point in time such that the variation of the log price is infinite in any left
neighbourhood of that point is not sufficient). The practical value of these
schemes is tempered by their use of the Axiom of Choice.


title:
On simulating processor schedules and network protocols within CPS using
  TrueTime

abstract:
  Studying cyber-physical system (CPS) for a given network protocol and
processor schedules is a challenging task. This investigation illustrates the
role of TrueTime a MATLAB package for simulating CPS encapsulating information
on processor schedules, and network protocols. Properties of CPS such as
temporal behaviors, performance and stability can be studied using the TrueTime
tool. Furthermore, these simulations can be used to benchmark design and
propose design alternatives. The procedure to use the toolbox for simulations
and instantiate various blocks to study CPS is illustrated in the paper.
Finally, an illustrative example has been presented of CPS simulation with
wireless network. Our example demonstrates that TrueTime is a useful tool for
studying CPS performance, timing behavior, schedulability analysis, and
studying suitable network protocols.


title: Structure Formation due to Antagonistic Salts

abstract:
  Antagonistic salts are composed of hydrophilic and hydrophobic ions. In a
mixture solvent (water-oil) such ion pairs are preferentially attracted to
water or oil, giving rise to a coupling between the charge density and the
composition. First, they form a large electric double layer at a water-oil
interface, reducing the surface tension and producing mesophases. Here, the
cations and anions are loosely bound by the Coulomb attraction across the
interface on the scale of the Debye screening length. Second, on solid
surfaces, hydrophilic (hydrophobic) ions are trapped in a water-rich (oil-rich)
adsorption layer, while those of the other species are expelled from the layer.
This yields a solvation mechanism of local charge separation near a solid. In
particular, near the solvent criticality, disturbances around solid surfaces
can become oscillatory in space. In mesophases, we calculate periodic
structures, which resemble those in experiments.


title: The 492 GHz emission of Sgr A* constrained by ALMA

abstract:
  We report linearly polarized continuum emission properties of Sgr A* at
$\sim$492 GHz, based on the Atacama Large Millimeter Array (ALMA) observations.
We used the observations of the likely unpolarized continuum emission of Titan,
and the observations of C\textsc{i} line emission, to gauge the degree of
spurious polarization. The Stokes I flux of 3.6$\pm$0.72 Jy during our run is
consistent with extrapolations from the previous, lower frequency observations.
We found that the continuum emission of Sgr A* at $\sim$492 GHz shows large
amplitude differences between the XX and the YY correlations. The observed
intensity ratio between the XX and YY correlations as a function of parallactic
angle may be explained by a constant polarization position angle of
$\sim$158$^{\circ}$$\pm$3$^{\circ}$. The fitted polarization percentage of Sgr
A* during our observational period is 14\%$\pm$1.2\%. The calibrator quasar
J1744-3116 we observed at the same night can be fitted to Stokes I = 252 mJy,
with 7.9\%$\pm$0.9\% polarization in position angle P.A. =
4.1$^{\circ}$$\pm$4.2$^{\circ}$. The observed polarization percentage and
polarization position angle in the present work appear consistent with those
expected from longer wavelength observations in the period of 1999-2005. In
particular, the polarization position angle at 492 GHz, expected from the
previously fitted 167$^{\circ}$$\pm$7$^{\circ}$ intrinsic polarization position
angle and (-5.6$\pm$0.7)$\times$10$^{5}$ rotation measure, is 155$^{+9}_{-8}$,
which is consistent with our new measurement of polarization position angle
within 1$\sigma$. The polarization percentage and the polarization position
angle may be varying over the period of our ALMA 12m Array observations, which
demands further investigation with future polarization observations.


title:
HyperNet: Towards Accurate Region Proposal Generation and Joint Object
  Detection

abstract:
  Almost all of the current top-performing object detection networks employ
region proposals to guide the search for object instances. State-of-the-art
region proposal methods usually need several thousand proposals to get high
recall, thus hurting the detection efficiency. Although the latest Region
Proposal Network method gets promising detection accuracy with several hundred
proposals, it still struggles in small-size object detection and precise
localization (e.g., large IoU thresholds), mainly due to the coarseness of its
feature maps. In this paper, we present a deep hierarchical network, namely
HyperNet, for handling region proposal generation and object detection jointly.
Our HyperNet is primarily based on an elaborately designed Hyper Feature which
aggregates hierarchical feature maps first and then compresses them into a
uniform space. The Hyper Features well incorporate deep but highly semantic,
intermediate but really complementary, and shallow but naturally
high-resolution features of the image, thus enabling us to construct HyperNet
by sharing them both in generating proposals and detecting objects via an
end-to-end joint training strategy. For the deep VGG16 model, our method
achieves completely leading recall and state-of-the-art object detection
accuracy on PASCAL VOC 2007 and 2012 using only 100 proposals per image. It
runs with a speed of 5 fps (including all steps) on a GPU, thus having the
potential for real-time processing.


title: Calibration of higher eigenmodes of cantilevers

abstract:
  A method is presented for calibrating the higher eigenmodes (resonance modes)
of atomic force microscopy cantilevers that can be performed prior to any
tip-sample interaction. The method leverages recent efforts in accurately
calibrating the first eigenmode by providing the higher-mode stiffness as a
ratio to the first mode stiffness. A one-time calibration routine must be
performed for every cantilever type to determine the power-law relationship
between stiffness and frequency, which is then stored for future use on similar
cantilevers. Then, future calibrations only require a measurement of the ratio
of resonance frequencies and the stiffness of the first mode. This method is
verified through stiffness measurements using three independent approaches:
interferometric measurement, AC approach-curve calibration, and finite element
analysis simulation. Power-law values for calibrating higher-mode stiffnesses
are reported for three popular multifrequency cantilevers. Once the higher-mode
stiffnesses are known, the amplitude of each mode can also be calibrated from
the thermal spectrum by application of the equipartition theorem.


title:
Convex Computation of the Basin of Stability to Measure the Likelihood
  of Falling: A Case Study on the Sit-to-Stand Task

abstract:
  Locomotion in the real world involves unexpected perturbations, and therefore
requires strategies to maintain stability to successfully execute desired
behaviours. Ensuring the safety of locomoting systems therefore necessitates a
quantitative metric for stability. Due to the difficulty of determining the set
of perturbations that induce failure, researchers have used a variety of
features as a proxy to describe stability. This paper utilises recent advances
in dynamical systems theory to develop a personalised, automated framework to
compute the set of perturbations from which a system can avoid failure, which
is known as the basin of stability. The approach tracks human motion to
synthesise a control input that is analysed to measure the basin of stability.
The utility of this analysis is verified on a Sit-to-Stand task performed by 15
individuals. The experiment illustrates that the computed basin of stability
for each individual can successfully differentiate between less and more stable
Sit-to-Stand strategies.


title: Chaos control of Hastings-Powell model by combining chaotic motions

abstract:
  In this paper, we propose a Parameter Switching (PS) algorithm as a new chaos
control method for the Hastings-Powell (HP) system. The PS algorithm is a
convergent scheme that switches the control parameter within a set of values
while the controlled system is numerically integrated. The attractor obtained
with the PS algorithm matches the attractor obtained by integrating the system
with the parameter replaced by the averaged value of the switched parameter
values. The switching rule can be applied periodically or randomly over a set
of given values. In this way, every stable cycle of the HP system can be
approximated if its underlying parameter value equalizes the average value of
the switching values. Moreover, the PS algorithm can be viewed as a
generalization of Parrondo's game, which is applied for the first time to the
HP system, by showing that losing strategy can win: "losing + losing =
winning". If "loosing" is replaced with "chaos" and, "winning" with "order" (as
the opposite to "chaos"), then by switching the parameter value in the HP
system within two values, which generate chaotic motions, the PS algorithm can
approximate a stable cycle so that symbolically one can write "chaos + chaos =
regular". Also, by considering a different parameter control, new complex
dynamics of the HP model are revealed.


title:
On the elliptic nonabelian Fourier transform for unipotent
  representations of p-adic groups

abstract:
  In this paper, we consider the relation between two nonabelian Fourier
transforms. The first one is defined in terms of the Langlands-Kazhdan-Lusztig
parameters for unipotent elliptic representations of a split p-adic group and
the second is defined in terms of the pseudocoefficients of these
representations and Lusztig's nonabelian Fourier transform for characters of
finite groups of Lie type. We exemplify this relation in the case of the p-adic
group of type G_2.


title: Mass spectra of dimesonic states in light flavour sector

abstract:
  Masses of the dimesonic (meson-antimeson) molecular states are calculated
using Yukawa like and meson exchange potential in semi-relativistic approach.
The digamma decay width of the dimesonic systems are evaluated using the
spectroscopic parameters. Many states such as $f{}_{0}$(980), $h{}_{1}$(1380),
$a{}_{0}$(1450), $f{}_{0}$(1500), $f{}_{2}'$(1525), $f{}_{2}$(1565),
$a{}_{2}$(1700), $f{}_{0}$(1710), $f{}_{2}$(1810), $f{}_{2}$(2010) have shown
the signature of dimesonic molecules. Their masses and digamma widths are in
good agreement with other theoretical results as well as experimental
measurements.


title: GAL: A Global-Attributes Assisted Labeling System for Outdoor Scenes

abstract:
  An approach that extracts global attributes from outdoor images to facilitate
geometric layout labeling is investigated in this work. The proposed
Global-attributes Assisted Labeling (GAL) system exploits both local features
and global attributes. First, by following a classical method, we use local
features to provide initial labels for all super-pixels. Then, we develop a set
of techniques to extract global attributes from 2D outdoor images. They include
sky lines, ground lines, vanishing lines, etc. Finally, we propose the GAL
system that integrates global attributes in the conditional random field (CRF)
framework to improve initial labels so as to offer a more robust labeling
result. The performance of the proposed GAL system is demonstrated and
benchmarked with several state-of-the-art algorithms against a popular outdoor
scene layout dataset.


title:
Recent Advances in Cloud Radio Access Networks: System Architectures,
  Key Techniques, and Open Issues

abstract:
  As a promising paradigm to reduce both capital and operating expenditures,
the cloud radio access network (C-RAN) has been shown to provide high spectral
efficiency and energy efficiency. Motivated by its significant theoretical
performance gains and potential advantages, C-RANs have been advocated by both
the industry and research community. This paper comprehensively surveys the
recent advances of C-RANs, including system architectures, key techniques, and
open issues. The system architectures with different functional splits and the
corresponding characteristics are comprehensively summarized and discussed. The
state-of-the-art key techniques in C-RANs are classified as: the fronthaul
compression, large-scale collaborative processing, and channel estimation in
the physical layer; and the radio resource allocation and optimization in the
upper layer. Additionally, given the extensiveness of the research area, open
issues and challenges are presented to spur future investigations, in which the
involvement of edge cache, big data mining, social-aware device-to-device,
cognitive radio, software defined network, and physical layer security for
C-RANs are discussed, and the progress of testbed development and trial test
are introduced as well.


title:
Production of Heavy neutrino in next-to-leading order QCD at the LHC and
  beyond

abstract:
  Majorana and pseudo-Dirac heavy neutrinos are introduced into the type-I and
inverse seesaw models, respectively, in explaining the naturally small neutrino
mass. TeV scale heavy neutrinos can also be accommodated to have a sizable
mixing with the Standard Model light neutrinos, through which they can be
produced and detected at the high energy colliders. In this paper we consider
the Next-to-Leading Order QCD corrections to the heavy neutrino production, and
study the scale variation in cross-sections as well as the kinematic
distributions with different final states at $14$ TeV LHC and also in the
context of $100$ TeV hadron collider. The repertoire of the Majorana neutrino
is realized through the characteristic signature of the same-sign dilepton
pair, whereas, due to a small lepton number violation, the pseudo-Dirac heavy
neutrino can manifest the trileptons associated with missing energy in the
final state. Using the $\sqrt{s}=8$ TeV, $20.3$ fb$^{-1}$ and $19.7$ fb$^{-1}$
data at the ATLAS and CMS respectively, we obtain prospective scale dependent
upper bounds of the light-heavy neutrino mixing angles for the Majorana heavy
neutrinos at the $14$ TeV LHC and $100$ TeV collider. Further exploiting a
recent study on the anomalous multilepton search by CMS at $\sqrt{s}=8$ TeV
with $19.5$ fb$^{-1}$ data, we also obtain the prospective scale dependent
upper bounds on the mixing angles for the pseudo-Dirac neutrinos. We thus
project a scale dependent prospective reach using the NLO processes at the $14$
TeV LHC.


title: The complexity of isomorphism between countably based profinite groups

abstract:
  A topological group G is profinite if it is compact and totally disconnected.
Equivalently, G is the inverse limit of a surjective system of finite groups
carrying the discrete topology. We discuss how to represent a countably based
profinite group as a point in a Polish space. Then we study the complexity of
isomorphism using the theory of Borel reducibility in descriptive set theory.
For topologically finitely generated profinite groups this complexity is the
same as the one of identity for reals. In general, it is the same as the
complexity of isomorphism for countable graphs.


title: Open descent and strong approximation

abstract:
  We give a new version of the open descent theory of Harari and Skorobogatov.
As an application of the new version, we prove that some algebraic varieties
satisfy strong approximation.


title:
Pointwise convergence of ergodic averages of bounded measurable
  functions for amenable groups

abstract:
  Given any amenable group $G$ (with a left Haar measure $|\cdot|$ or $dg$), we
can select out a \textit{F{\o}lner subnet} $\{F_\theta,\theta\in\Theta\}$ from
any left F{\o}lner net in $G$, which is \textit{$L^\infty$-admissible}, namely,
for any Borel $G$-space $(X,\mathscr{X})$ and any $\varphi\in
L^\infty(X,\mathscr{X})$, \begin{gather*}
\lim_{\theta\in\Theta}\frac{1}{|F_\theta|}\int_{F_\theta}\varphi(gx)dg=\varphi^*(x)\
\forall x\in X\quad {\textrm{and}}\quad \varphi^*=(g\varphi)^*\ \forall g\in G.
\end{gather*} Moreover, if $G$ is $\sigma$-compact such as a locally compact
second countable Hausdorff amenable group, then $\varphi^*\in
L^\infty(X,\mathscr{X})$, $\varphi^*(gx)=\varphi^*(x)$ \textit{a.e.}, and
$\varphi^*$ is \textit{a.e.} independent of the choice of the admissible
F{\o}lner net $\{F_\theta,\theta\in\Theta\}$ in $G$.
  Consequently, we may easily obtain the ergodic disintegration of invariant
probability measures for any $\sigma$-compact amenable group acting Borel on a
compact metric space $X$ by continuous transformations of $X$, and the
existence of $\sigma$-finite invariant Radon measures for any Borel action of
an amenable group on a locally compact, $\sigma$-compact, metric space $X$ by
continuous maps of $X$, and a $L^\infty$-pointwise multiple ergodic theorem.


title: A note on extremal results on directed acyclic graphs

abstract:
  The family of Directed Acyclic Graphs as well as some related graphs are
analyzed with respect to extremal behavior in relation with the family of
intersection graphs for families of boxes with transverse intersection.


title: Asteroseismology of the DBV star CBS 114

abstract:
  Asteroseismology is an unique and powerful tool to detect the internal
structure of stars. CBS 114 is the sixth known pulsating DBV star. It was
observed by Handler, Metcalfe, \& Wood at South African Astronomical
Observatory over 3 weeks in 2001. Then, it was observed by Metcalfe et al. at
Bohyunsan Optical Astronomy Observatory and McDonald Observatory respectively
for 7 nights in 2004. Totally 2 triplets, 4 doublets, and 5 singlets were
identified. The frequency splitting values are very different, from 5.2 $\mu$Hz
to 11.9 $\mu$Hz, which may reflect differential rotations. We evolve grids of
white dwarf models by \texttt{MESA}. Cores, added with He/C envelopes, of those
white dwarf models are inserted into \texttt{WDEC} to evolve grids of DBV star
models. With those DBV star models, we calculate eigenperiods. Those calculated
periods are used to fit observed periods. A best-fitting model is selected. The
parameters are $T_{eff}$ = 25000 K, $M_{*}$ = 0.740 $M_{\odot}$, and
log($M_{He}/M_{*}$) = -4.5. With the massive stellar mass, the effective
temperature is close to previous spectroscopic result. In addition, kinetic
energy distributions are calculated for the best-fitting model. We find that
the observed modes with large frequency splitting values are fitted by the
calculated modes with much kinetic energy distributed in C/O core. After
preliminary analysis, we suggest that the C/O core may rotate at least 2 times
faster than the helium layer for CBS 114.


title: Soliton collisions in soft magnetic nanotube with uniaxial anisotropy

abstract:
  The structure of stable magnetic solitons of various orders in soft magnetic
nanotube with uniaxial magnetic anisotropy has been studied using numerical
simulation. Solitons of even order are immobile in axially applied magnetic
field. Odd solitons show decreased mobility with respect to that of head-to
head domain wall. Solitons of various orders can participate in nanotube
magnetization reversal process. Various coalescence and decomposition processes
in soliton assembly are considered. It is shown that the general magnetization
state of magnetic nanotube consists of chains of magnetic solitons of various
orders.


title:
Influence of intrinsic decoherence on tripartite entanglement and
  bipartite fidelity of polar molecules in pendular states

abstract:
  An array of ultracold polar molecules trapped in an external electric field
is regarded as a promising carrier of quantum information. Under the action of
this field, molecules are compelled to undergo pendular oscillations by the
Stark effect. Particular attention has been paid to the influence of intrinsic
decoherence on the model of linear polar molecular pendular states, thereby we
evaluate the tripartite entanglement with negativity, as well as fidelity of
bipartite quantum systems for input and output signals using electric dipole
moments of polar molecules as qubits. According to this study, we consider
three typical initial states for both systems respectively, and investigate the
temporal evolution with variable values of the external field intensity, the
intrinsic decoherence factor and the dipole-dipole interaction. Thus we
demonstrate the sound selection of these three main parameters to obtain the
best entanglement degree and fidelity.


title: On Popoviciu-Ionescu functional equation

abstract:
  We study a functional equation first proposed by T. Popoviciu in 1955. It was
solved for the easiest case by Ionescu in 1956 and, for the general case, by
Ghiorcoiasiu and Roscau, and Rad\'o in 1962. Our solution is based on a
generalization of Rad\'o's theorem to distributions in a higher dimensional
setting and, as far as we know, is different than existing solutions. Finally,
we propose several related open problems.


title:
A Direct Elliptic Solver Based on Hierarchically Low-rank Schur
  Complements

abstract:
  A parallel fast direct solver for rank-compressible block tridiagonal linear
systems is presented. Algorithmic synergies between Cyclic Reduction and
Hierarchical matrix arithmetic operations result in a solver with $O(N \log^2
N)$ arithmetic complexity and $O(N \log N)$ memory footprint. We provide a
baseline for performance and applicability by comparing with well known
implementations of the $\mathcal{H}$-LU factorization and algebraic multigrid
with a parallel implementation that leverages the concurrency features of the
method. Numerical experiments reveal that this method is comparable with other
fast direct solvers based on Hierarchical Matrices such as $\mathcal{H}$-LU and
that it can tackle problems where algebraic multigrid fails to converge.


title: The Bishop-Phelps-Bollob\'as property for compact operators

abstract:
  We study the Bishop-Phelps-Bollob\'as property (BPBp for short) for compact
operators. We present some abstract techniques which allows to carry the BPBp
for compact operators from sequence spaces to function spaces. As main
applications, we prove the following results. Let $X$, $Y$ be Banach spaces. If
$(c_0,Y)$ has the BPBp for compact operators, then so do $(C_0(L),Y)$ for every
locally compact Hausdorff topological space $L$ and $(X,Y)$ whenever $X^*$ is
isometrically isomorphic to $\ell_1$. If $X^*$ has the Radon-Nikod\'ym property
and $(\ell_1(X),Y)$ has the BPBp for compact operators, then so does
$(L_1(\mu,X),Y)$ for every positive measure $\mu$; as a consequence,
$(L_1(\mu,X),Y)$ has the the BPBp for compact operators when $X$ and $Y$ are
finite-dimensional or $Y$ is a Hilbert space and $X=c_0$ or $X=L_p(\nu)$ for
any positive measure $\nu$ and $1< p< \infty$. For $1\leqslant p <\infty$, if
$(X,\ell_p(Y))$ has the BPBp for compact operators, then so does
$(X,L_p(\mu,Y))$ for every positive measure $\mu$ such that $L_1(\mu)$ is
infinite-dimensional. If $(X,Y)$ has the BPBp for compact operators, then so do
$(X,L_\infty(\mu,Y))$ for every $\sigma$-finite positive measure $\mu$ and
$(X,C(K,Y))$ for every compact Hausdorff topological space $K$.


title: Reconstruction of chaotic neural network from observed firing rates

abstract:
  Randomly coupled neural fields demonstrate chaotic variation of firing rates,
if the coupling is strong enough, as has been shown by Sompolinsky et. al
[Phys. Rev. Lett., v. 61, 259 (1988)]. We present a method for reconstruction
of the coupling matrix from the observations of the chaotic firing rates. The
approach is based on the particular property of the nonlinearity in the
coupling, as the latter is determined by a sigmoidal gain function. We
demonstrate that for a large enough data set, the method gives an accurate
estimation of the coupling matrix and of other parameters of the system,
including the gain function.


title: Gauge-invariant Lagrangians for mixed-antisymmetric higher spin fields

abstract:
  Lagrangian descriptions of irreducible and reducible integer higher-spin
representations of the Poincare group subject to a Young tableaux
$Y[\hat{s}_1,\hat{s}_2]$ with two columns are constructed within a metric-like
formulation in a $d$-dimensional flat space-time on the basis of a BRST
approach extending the results of [arXiv:1412.0200[hep-th]]. A
Lorentz-invariant resolution of the BRST complex within both the constrained
and unconstrained BRST formulations produces a gauge-invariant Lagrangian
entirely in terms of the initial tensor field $\Phi_{[\mu]_{\hat{s}_1},
[\mu]_{\hat{s}_2}}$ subject to $Y[\hat{s}_1,\hat{s}_2]$ with an additional
tower of gauge parameters realizing the $(\hat{s}_1-1)$-th stage of
reducibility with a specific dependence on the value
$(\hat{s}_1-\hat{s}_2)=0,1,...,\hat{s}_1$. Minimal BRST--BV action is
suggested, being proper solution to the master equation in the minimal sector
and providing objects appropriate to construct interacting Lagrangian
formulations with mixed-antisymmetric fields in a general framework.


title:
Modeling and study a general vacation queuing system with impatience
  customers

abstract:
  In this paper we models and studies a general vacation queueing model with
impatient customers. We first propose a sufficient condition for the existence
of the stationary workload process. We then give an integral equation for the
independent and identically distributed case. This integral equation is solved
when customers arrive according to a Poisson Point process. A relationship
between the tail of the waiting time distribution and the tail of service
distribution is also given.


title:
On a duality formula for certain sums of values of poly-Bernoulli
  polynomials and its application

abstract:
  We prove a duality formula for certain sums of values of poly-Bernoulli
polynomials which generalizes dualities for poly-Bernoulli numbers. We first
compute two types of generating functions for these sums, from which the
duality formula is apparent. Secondly we give an analytic proof of the duality
from the viewpoint of our previous study of zeta-functions of Arakawa-Kaneko
type. As an application, we give a formula that relates poly-Bernoulli numbers
to the Genocchi numbers.


title:
Interpreting the macroscopic pointer by analyzing the
  Einstein-Podolsky-Rosen steering of an entangled macroscopic superposition
  state

abstract:
  We examine Einstein-Podolsky-Rosen's (EPR) steering nonlocality for two
realisable Schrodinger cat-type states where a meso/ macroscopic system (called
the "cat"-system) is entangled with a spin-$1/2$ system. For large cat-systems,
we show that a local hidden state model is near-satisfied, meaning that the
cat-system can be consistent with being in a mixture of "dead" and "alive"
states despite that it is entangled with the spin system. We justify that a
rigorous signature of the Schrodinger cat-type paradox is the EPR-steering of
the cat-system and provide two experimental signatures. This leads to a hybrid
quantum/ classical interpretation of the macroscopic pointer of a measurement
device and suggests many Schrodinger cat-type paradoxes can be explained by
microscopic nonlocality.


title: Quantum cosmology with k-Essence theory

abstract:
  A class of $k$-Essence cosmological models, with a power law kinetic term, is
quantised in the mini-superspace. It is shown that for a specific
configuration, corresponding to a pressureless fluid, a Schr\"odinger-type
equation is obtained with the scalar field playing the r\^ole of time. The
resulting quantum scenario reveals a bounce, the classical behaviour being
recovered asymptotically.


title:
Assessment and Enhancement of {SAR} non-coherent Change Detection
  Techniques Following Oil Spills

abstract:
  In this study the detection of the oil spill using synthetic aperture radar
(SAR) imagery is considered. Detection of the oil spill is performed using
change detection algorithms between imagery acquired at different times. The
specific algorithms used are the correlation coefficient change statistic and
the intensity ratio change statistic algorithms. Therefore these algorithms and
the probabilistic selection of the threshold criteria is reviewed and
discussed. A recently offered change detection method which depends on the idea
of generating two different final change maps of two images in a sequence, is
used. First final change map is obtained by cumulatively adding the sequences
of change maps in such a manner that common change areas are excluded and
uncommon change areas are included. The second final change map is obtained by
comparing the first and the last images in the temporal sequence. This method
requires at least three images to be employed and can be generalized to longer
temporal image sequences. The purpose of this approach is to provide a double
check mechanism to the conventional approach and thus to reduce the probability
of false alarm and enhance the change detection. The algorithms mentioned are
applied to a 2010 Gulf of Mexico oil spill imagery together with the method
described. It is shown that intensity ratio change statistic is a better tool
for identification of the changes due to the oil spill compared to the
correlation coefficient change statistic. It is also shown that two final
change map method can reduce the probability of false alarm. The data used in
this study is acquired by the Japanese Aerospace Agency's Advanced Land
Observing Satellite (ALOS) through Alaska SAR Facility (ASF) at the University
of Alaska, Fairbanks, AK.


title:
Spin relaxation signature of colossal magnetic anisotropy in platinum
  atomic chains

abstract:
  Recent experimental data demonstrate emerging magnetic order in platinum
atomically thin nanowires. Furthermore, an unusual form of magnetic anisotropy
-- colossal magnetic anisotropy (CMA) -- was earlier predicted to exist in
atomically thin platinum nanowires. Using spin dynamics simulations based on
first-principles calculations, we here explore the spin dynamics of atomically
thin platinum wires to reveal the spin relaxation signature of colossal
magnetic anisotropy, comparing it with other types of anisotropy such as
uniaxial magnetic anisotropy (UMA). We find that the CMA alters the spin
relaxation process distinctly and, most importantly, causes a large speed-up of
the magnetic relaxation compared to uniaxial magnetic anisotropy. The magnetic
behavior of the nanowire exhibiting CMA should be possible to identify
experimentally at the nanosecond time scale for temperatures below 5 K. This
time-scale is accessible in e.g., soft x-ray free electron laser experiments.


title:
Handling missing data in large healthcare dataset: a case study of
  unknown trauma outcomes

abstract:
  Handling of missed data is one of the main tasks in data preprocessing
especially in large public service datasets. We have analysed data from the
Trauma Audit and Research Network (TARN) database, the largest trauma database
in Europe. For the analysis we used 165,559 trauma cases. Among them, there are
19,289 cases (13.19\%) with unknown outcome. We have demonstrated that these
outcomes are not missed `completely at random' and, hence, it is impossible
just to exclude these cases from analysis despite the large amount of available
data. We have developed a system of non-stationary Markov models for the
handling of missed outcomes and validated these models on the data of 15,437
patients which arrived into TARN hospitals later than 24 hours but within 30
days from injury. We used these Markov models for the analysis of mortality. In
particular, we corrected the observed fraction of death. Two na\"ive approaches
give 7.20\% (available case study) or 6.36\% (if we assume that all unknown
outcomes are `alive'). The corrected value is 6.78\%. Following the seminal
paper of Trunkey (1983) the multimodality of mortality curves has become a much
discussed idea. For the whole analysed TARN dataset the coefficient of
mortality monotonically decreases in time but the stratified analysis of the
mortality gives a different result: for lower severities the coefficient of
mortality is a non-monotonic function of the time after injury and may have
maxima at the second and third weeks. The approach developed here can be
applied to various healthcare datasets which experience the problem of lost
patients and missed outcomes.


title:
Accurate and fast fiber transfer delay measurement based on phase
  discrimination and frequency measurement

abstract:
  An accurate and fast fiber transfer delay measurement method is demonstrated.
As a key technique, a simple ambiguity resolving process based on phase
discrimination and frequency measurement is used to overcome the contradiction
between measurement accuracy and system complexity. The optimized system
achieves a high accuracy of 0.3 ps with a 0.1 ps resolution, and a large
dynamic range up to 50 km as well as no dead zone.


title:
Non-linear dynamics induced by linear wave interactions in multi-layered
  flows

abstract:
  Using simple kinematics, we propose a general theory of linear wave
interactions between the interfacial waves of a two dimensional (2D), inviscid,
multi-layered fluid system. The strength of our formalism is that one does not
have to specify the physics of the waves in advance. Wave interactions may lead
to instabilities, which may or may not be of the familiar "normal-mode" type.
Contrary to intuition, the underlying dynamical system describing linear wave
interactions is found to be non-linear. Specifically, a saw-tooth jet profile
with three interfaces possessing kinematic and geometric symmetry is explored.
Fixed points of the system for different ranges of a Froude number like control
parameter $\gamma$ are derived, and their stability evaluated. Depending upon
the initial condition and $\gamma$, the dynamical system may reveal transient
growth, weakly positive Lyapunov exponents, as well as different non-linear
phenomena such as formation of periodic and pseudo-periodic orbits. All these
occur for those ranges of $\gamma$ where normal-mode theory predicts neutral
stability. Such rich non-linear phenomena is not observed in 2D dynamical
system resulting from the $2$-wave problem, which only reveals stable and
unstable nodes.


title: Journey to the Center of the Earth

abstract:
  We survey some results on travel time tomography. The question is whether we
can determine the anisotropic index of refraction of a medium by measuring the
travel times of waves going through the medium. This can be recast as geometry
problems, the boundary rigidity problem and the lens rigidity problem. The
boundary rigidity problem is whether we can determine a Riemannian metric of a
compact Riemannian manifold with boundary by measuring the distance function
between boundary points. The lens rigidity problem problem is to determine a
Riemannian metric of a Riemannian manifold with boundary by measuring for every
point and direction of entrance of a geodesic the point of exit and direction
of exit and its length. The linearization of these two problems is tensor
tomography. The question is whether one can determine a symmetric two-tensor
from its integrals along geodesics. We emphasize recent results on boundary and
lens rigidity and in tensor tomography in the partial data case.


title: 0.5 keV soft X-ray attosecond continua

abstract:
  Attosecond light pulses in the extreme ultraviolet have drawn a great deal of
attention due to their ability to interrogate electronic dynamics in real time.
Nevertheless, to follow charge dynamics and excitations in materials, element
selectivity is a prerequisite, which demands such pulses in the soft X-ray
region, above 200 eV, to simultaneously cover several fundamental absorption
edges of the constituents of the materials. Here, we experimentally demonstrate
the exploitation of a transient phase matching regime to generate carrier
envelope controlled soft X-ray supercontinua with pulse energies up to 2.9 +/-
0.1 pJ and a flux of (7.3 +/- 0.1)x10^7 photons/s across the entire water
window and attosecond pulses with 13 as transform limit. Our results herald
attosecond science at the fundamental absorption edges of matter by bridging
the gap between ultrafast temporal resolution and element specific probing.


title:
Profiled spectral lines generated by Keplerian discs orbiting in the
  Bardeen and Ayon-Beato-Garcia spacetimes

abstract:
  Shape and frequency-shift map of direct and indirect images of Keplerian
discs orbiting in Bardeen and Ayon-Beato-Garcia (ABG) black hole and no-horizon
spacetimes are determined. Then profiles of spectral lines generated in the
innermost parts of the Keplerian discs in the Bardeen and ABG spacetimes are
constructed. The frequency-shift maps and profiled spectral lines are compared
to those generated in the field of Schwarzschild black holes and possible
observationally relevant signatures of the regular black hole and no-horizon
spacetimes are discussed. We demonstrate that differences relative to the
Schwarzschild spacetimes are for the no-horizon spacetimes much more profound
in comparison to the regular black hole spacetimes and increase with increasing
charge parameter of the spacetime. The differences are stronger for small and
large inclination angles than for mediate ones. For the no-horizon spacetimes,
the differences enable to distinguish the Bardeen and ABG spacetime, if
inclination angle to the distant observer is known. We also show that
contribution of the so called ghost images to the profiled lines increases with
increasing charge parameter of the spacetimes.


title: Positive solutions to sublinear elliptic problem

abstract:
  Let $L$ be a second order elliptic operator $L$ with smooth coefficients
defined on a domain $\Omega $ in $\mathbb{R}^d $, $d\geq3$, such that $L1\leq
0$. We study existence and properties of continuous solutions to the following
problem
  \begin{equation}\label{00} Lu=\varphi(\cdot,u),% & \hbox{in $\Omega $; in the
sens of distribution;} \\ \end{equation} in $\Omega,$ where $\Omega$ is a
Greenian domain for $L$ {(possibly unbounded)} in $\mathbb{R}^d$ and $\varphi $
is a nonnegative function on $\Omega\times [0,+\infty [$ increasing with
respect to the second variable. By means of thinness, we obtain a
characterization of $\varphi$ for which \eqref{00} has a nonnegative nontrivial
bounded solution.


title:
Optimizing the Diffusion System Based on Continuous-Time Consensus
  Algorithm

abstract:
  Traditionally, systems governed by linear Partial Differential Equations
(PDEs) are spatially discretized to exploit their algebraic structure and
reduce the computational effort for controlling them. Due to beneficial
insights of the PDEs, recently, the reverse of this approach is implemented
where a spatially-discrete system is approximated by a spatially-continuous
one, governed by linear PDEs forming diffusion equations. In the case of
distributed consensus algorithms, this approach is adapted to enhance its
convergence rate to the equilibrium. In previous studies within this context,
constant diffusion parameter is considered for obtaining the diffusion
equations. This is equivalent to assigning a constant weight to all edges of
the underlying graph in the consensus algorithm. Here, by relaxing this
restricting assumption, a spatially-variable diffusion parameter is considered
and by optimizing the obtained system, it is shown that significant
improvements are achievable in terms of the convergence rate of the obtained
spatially-continuous system. As a result of approximation, the system is
divided into two sections, namely, the spatially-continuous path branches and
the lattice core which connects these branches at one end. The optimized
weights and diffusion parameter for each of these sections are optimal
individually but considering the whole system, they are suboptimal. It is shown
that the symmetric star topology is an exception and the obtained results for
this topology are globally optimal. Furthermore, through variational method,
the results obtained for the symmetric star topology are validated and it is
shown that the variable diffusion parameter improves the robustness of the
system too.


title:
Quantum-inspired secure wireless communication protocol under spatial
  and local Gaussian noise assumptions

abstract:
  Inspired from quantum key distribution, we consider wireless communication
between Alice and Bob when the intermediate space between Alice and Bob is
controlled by Eve. That is, our model divides the channel noise into two parts,
the noise generated during the transmission and the noise generated in the
detector. Eve is allowed to control the former, but is not allowed to do the
latter. While the latter is assumed to be a Gaussian random variable, the
former is not assumed to be a Gaussian random variable. In this situation,
using backward reconciliation and the random sampling, we propose a protocol to
generate secure keys between Alice and Bob under the assumption that Eve's
detector has a Gaussian noise and Eve is out of Alice's neighborhood. In our
protocol, the security criteria are quantitatively guaranteed even with finite
block-length code based on the evaluation of error of the estimation of
channel.


title: On the Delay Performance of Interference Channels

abstract:
  A deep understanding of the queuing performance of wireless networks is
essential for the advancement of future wireless communications. The stochastic
nature of wireless channels in general gives rise to a time varying
transmission rate. In such an environment, interference is increasingly
becoming a key constraint. Obtaining an expressive model for offered service of
such channels has major implications in the design and optimization of future
networks. However, interference channels are not well-understood with respect
to their higher layer performance. The particular difficulty for handling
interference channels arises from the superposition of random fading processes
for the signals of the transmitters involved (i.e., for the signal of interest
and for the signals of the interferers). Starting from the distribution of the
signal-to-interference-plus-noise ratio (SINR), we derive a statistical
characterization of the underlying service process in terms of its Mellin
transform. Then, we adapt a recent stochastic network calculus approach for
fading channels to derive measures of the queuing performance of single- and
multi-hop wireless interference networks. Special cases of our solution include
noise-limited and interference-limited systems. A key finding of our analysis
is that for a given average signal and average sum interference power, the
performance of interfered systems not only depends on the relative strength of
the sum interference with respect to the signal-of-interest power, but also on
the interference structure (i.e., the number of interferers) as well as the
absolute levels.


title: CP Violation in the scalar sector

abstract:
  Models with an extended scalar sector may in principle provide new sources of
CP violation originating in the scalar potential. One of the simplest ways to
implement this idea is to have CP violation in a two-Higgs-doublet model. Here,
it leads to CP violation in trilinear weak gauge boson couplings. We discuss
how these couplings are becoming constrained in the alignment limit. In a model
with three Higgs doublets, subject to an $S_3$ symmetry, several complex vacua
are possible. Some of these, but not all, may lead to spontaneous CP violation.


title: The Number of Nodal Components of Arithmetic Random Waves

abstract:
  We study the number of nodal components (connected components of the set of
zeroes) of functions in the ensemble of arithmetic random waves, that is,
random eigenfunctions of the Laplacian on the flat $d$-dimensional torus
$\mathbb{T}^{d}$ ($d\ge2$). Let $f_{L}$ be a random solution to $\Delta
f+4\pi^{2}L^{2}f=0$ on $\mathbb{T}^{d}$, where $L^{2}$ is a sum of $d$ squares
of integers, and let $N_{L}$ be the random number of nodal components of
$f_{L}$. By recent results of Nazarov and Sodin, $\mathbb{E}\left\{
N_{L}/L^{d}\right\} $ tends to a limit $\nu>0$, depending only on $d$, as
$L\to\infty$ subject to a number-theoretic condition - the equidistribution on
the unit sphere of the normalized lattice points on the sphere of radius $L$.
This condition is guaranteed when $d\ge5$, but imposes restrictions on the
sequence of $L$ values when $2\le d\le4$. We prove the exponential
concentration of the random variables $N_{L}/L^{d}$ around their medians and
means (unconditionally) and around their limiting mean $\nu$ (under the
condition that it exists).