title:
The possibility to observe the non-standard interaction by the
  Hyperkamiokande atmospheric neutrino experiment

abstract:
  It was suggested that a tension between the mass-squared differences obtained
from the solar neutrino and KamLAND experiments can be solved by introducing
the non-standard flavor-dependent interaction in neutrino propagation. In this
paper we discuss the possibility to test such a hypothesis by atmospheric
neutrino observations at the future Hyper-Kamiokande experiment. Assuming that
the mass hierarchy is known, we find that the best-fit value from the solar
neutrino and KamLAND data can be tested at more than 8 $\sigma$, while the one
from the global analysis can be examined at 5.0 $\sigma$ (1.4 $\sigma$) for the
normal (inverted) mass hierarchy.


title: Random multiplicative walks on the residues modulo n

abstract:
  We introduce a new arithmetic function $a(n)$ defined to be the number of
random multiplications by residues modulo $n$ before the running product is
congruent to 0 modulo $n$. We give several formulas for computing the values of
this function and analyze its asymptotic behavior. We find that it is closely
related to $P_1(n)$, the largest prime divisor of $n$. In particular, $a(n)$
and $P_1(n)$ have the same average order asymptotically. Furthermore, the
difference between the functions $a(n)$ and $P_1(n)$ is $o(1)$ as $n$ tends to
infinity on a set with density approximately $0.623$. On the other hand
however, we see that (except on a set of density zero) the difference between
$a(n)$ and $P_1(n)$ tends to infinity on the integers outside this set. Finally
we consider the asymptotic behaviour of the difference between these two
functions and find that $\sum_{n\leq x}\big( a(n)-P_1(n)\big) \sim
\left(1-\frac{\pi}{4}\right)\sum_{n\leq x} P_2(n)$, where $P_2(n)$ is the
second largest divisor of $n$.


title: A method to reduce the rejection rate in Monte Carlo Markov Chains

abstract:
  We present a method for Monte Carlo sampling on systems with discrete
variables (focusing in the Ising case), introducing a prior on the candidate
moves in a Metropolis-Hastings scheme which can significantly reduce the
rejection rate, called the reduced-rejection-rate (RRR) method. The method
employs same probability distribution for the choice of the moves as
rejection-free schemes such as the method proposed by Bortz, Kalos and Lebowitz
(BKL) [Bortz et al. J.Comput.Phys. 1975]; however, it uses it as a prior in an
otherwise standard Metropolis scheme: it is thus not fully rejection-free, but
in a wide range of scenarios it is nearly so. This allows to extend the method
to cases for which rejection-free schemes become inefficient, in particular
when the graph connectivity is not sparse, but the energy can nevertheless be
expressed as a sum of two components, one of which is computed on a sparse
graph and dominates the measure. As examples of such instances, we demonstrate
that the method yields excellent results when performing Monte Carlo
simulations of quantum spin models in presence of a transverse field in the
Suzuki-Trotter formalism, and when exploring the so-called robust ensemble
which was recently introduced in Baldassi et al. [PNAS 2016]. Our code for the
Ising case is publicly available [https://github.com/carlobaldassi/RRRMC.jl],
and extensible to user-defined models: it provides efficient implementations of
standard Metropolis, the RRR method, the BKL method (extended to the case of
continuous energy specra), and the waiting time method [Dall and Sibani
Comput.Phys.Commun. 2001].


title: A String Model of Liquidity in Financial Markets

abstract:
  We consider a dynamic market model of liquidity where unmatched buy and sell
limit orders are stored in order books. The resulting net demand surface
constitutes the sole input to the model. We prove that generically there is no
arbitrage in the model when the driving noise is a stochastic string. Under the
equivalent martingale measure, the clearing price is a martingale, and options
can be priced under the no-arbitrage hypothesis. We consider several
parameterized versions of the model, and show some advantages of specifying the
demand curve as quantity as a function of price (as opposed to price as a
function of quantity). We calibrate our model to real order book data, compute
option prices by Monte Carlo simulation, and compare the results to observed
data.


title: Partial Breaking of Three-Fold Symmetry via Percolation of a Domain Wall

abstract:
  We show that suppression of vortex strings splits the order-disorder
transition in the three-state Potts ferromagnet on a simple cubic lattice and
opens up an intermediate phase characterized by partial breaking of the
three-fold symmetry and long-range order. In contrast, suppression of vortices
in the same model on a square lattice results in an intermediate phase with
enhanced U(1) symmetry and quasi-long-range order. We show that the difference
between the two phases originates from distinct patterns of domain wall
proliferation. A domain wall, separating the two most populous spin states,
percolates on its own in the former phase but remains at a percolation
threshold in the latter.


title: Electric transport in three-dimensional Skyrmion/monopole crystal

abstract:
  We study theoretically the transport properties of a three-dimensional spin
texture made from three orthogonal helices, which is essentially a lattice of
monopole-antimonopole pairs connected by Skyrmion strings. This spin structure
is proposed for MnGe based on the neutron scattering experiment as well as the
Lorentz transmission electron microscopy observation. Equipped with a
sophisticated spectral analysis method, we adopt finite temperature Green's
function technique to calculate the longitudinal dc electric transport in such
system. We consider conduction electrons interacting with spin waves of the
topologically nontrivial spin texture, wherein fluctuations of monopolar
emergent magnetic field enter. We study in detail the behavior of electric
resistivity under the influence of temperature, external magnetic field and a
characteristic monopole motion, especially a novel magnetoresistivity effect
describing the latest experimental observations in MnGe, wherein a topological
phase transition signifying strong correlation is identified.


title:
Multiple periodic solutions of Lagrangian systems of relativistic
  oscillators

abstract:
  Let $B_L$ the open ball in ${\bf R}^n$ centered at $0$, of radius $L$, and
let $\phi$ be a homeomorphism from $B_L$ onto ${\bf R}^n$ such that $\phi(0)=0$
and $\phi=\nabla\Phi$, where the function $\Phi:\bar {B_L}\to ]-\infty,0]$ is
continuous and strictly convex in $\bar {B_L}$, and of class $C^1$ in $B_L$.
Moreover, let $F:[0,T]\times {\bf R}^n\to {\bf R}$ be a function which is
measurable in $[0,T]$, of class $C^1$ in ${\bf R}^n$ and such that $\nabla_xF$
satisfies the $L^1$-Carath\'eodory conditions. Set $$K=\{u\in Lip([0,T],{\bf
R}^n) : |u'(t)|\leq L\ for\ a.e.\ t\in [0,T] , u(0)=u(T)\}\ ,$$ and define the
functional $I:K\to {\bf R}$ by $$I(u)=\int_0^T(\Phi(u'(t))+F(t,u(t)))dt$$ for
all $u\in K$. In [1], Brezis and Mawhin proved that any global minimum of $I$
in $K$ is a solution of the problem $$\cases{(\phi(u'))'=\nabla_xF(t,u) & in
$[0,T]$\cr & \cr u(0)=u(T)\ , u'(0)=u'(T)\ .\cr}$$ In the present paper, we
provide a set of conditions under which the functional $I$ has at least two
global minima in $K$. This seems to be the first result of this kind. The main
tool of our proof is the well-posedness result obtained in [3].


title: Evolution of Supernova Remnants near the Galactic Center

abstract:
  Supernovae near the galactic center evolve differently from regular galactic
supernovae. This is mainly due to the environment into which the supernova
remnants propagate. Instead of a static, uniform density medium, SNRs near the
galactic center propagate into a wind swept environment with a velocity away
from the galactic center, and a graded density profile. This causes these SNRs
to be non - spherical, and to evolve faster than their galactic counterparts.
We develop an analytic theory for the evolution of explosions within a stellar
wind, and verify it using a hydrodynamic code. We show that such explosions can
evolve in one of three possible morphologies. Using these results we discuss
the association between the two SNRs (SGR East and SGR A's bipolar radio/X-ray
Lobes) and the two neutron stars (the cannonball and SGR J1745-2900) near the
galactic center. We show that, given the morphologies of the SNR and positions
of the neutron stars, the only possible association is between SGR A's bipolar
radio/X-ray Lobes and SGR J1745-2900. The compact object created in the
explosion of SGR East remains undetected, and the SNR of the supernova that
created the cannonball has already disappeared.


title: Pivotal structures of the Drinfeld center of a finite tensor category

abstract:
  We classify the pivotal structures of the Drinfeld center
$\mathcal{Z}(\mathcal{C})$ of a finite tensor category $\mathcal{C}$. As a
consequence, every pivotal structure of $\mathcal{Z}(\mathcal{C})$ can be
obtained from a pair $(\beta, j)$ consisting of an invertible object $\beta$ of
$\mathcal{C}$ and an isomorphism $j: \beta \otimes (-) \otimes \beta^* \to
(-)^{**}$ of monoidal functors.


title:
Two-loop QCD Correction to Massive Spin-2 Resonance $ \to q ~ \bar{q} ~
  g $

abstract:
  Two-loop QCD correction to massive spin-2 Graviton decaying to $q ~ + ~
\bar{q}~ + ~g$ is presented considering a generic universal spin-2 coupling to
the SM through the conserved energy-momentum tensor. Such a massive spin-2
particle can arise in extra-dimensional models. The ultraviolet and infrared
structure of the QCD amplitudes are studied. In dimensional regularisation, the
infrared pole structure is in agreement with Catani's proposal, confirming the
universal factorization property of QCD amplitudes, even with the spin-2
tensorial coupling. This computation now completes the full two-loop QCD
corrections for the production of a spin-2 in association with a jet.


title:
The Regularization Theory of the Krylov Iterative Solvers LSQR, CGLS,
  LSMR and CGME For Linear Discrete Ill-Posed Problems

abstract:
  For the large-scale linear discrete ill-posed problem $\min\|Ax-b\|$ or
$Ax=b$ with $b$ contaminated by a white noise, Lanczos bidiagonalization based
LSQR and its mathematically equivalent CGLS are most commonly used. They have
intrinsic regularizing effects, where the number $k$ of iterations plays the
role of regularization parameter. However, hitherto there has been no answer to
the long-standing fundamental concern of Bj\"{o}rck and Eld\'{e}n in 1979: {\em
for which kinds of problems LSQR and CGLS can find best possible regularized
solutions}? Here a best possible regularized solution means that it is at least
as accurate as the best regularized solution obtained by the truncated singular
value decomposition (TSVD) method or by standard-form Tikhonov regularization
and cannot be improved under certain conditions. In this paper we make a
detailed analysis on the regularization of LSQR for severely, moderately and
mildly ill-posed problems. For the first two kinds of problems, we prove that
LSQR finds best possible solutions at semi-convergence and the following
results hold until semi-convergence: (i) the $k$-step Lanczos bidiagonalization
always generates a near best rank $k$ approximation to $A$; (ii) the $k$ Ritz
values always approximate the first $k$ large singular values of $A$ in natural
order; (iii) the $k$-step LSQR always captures the $k$ dominant SVD components
of $A$; (iv) the diagonals and subdiagonals of the bidiagonal matrices
generated by Lanczos bidiagonalization decay as fast as the singular values of
$A$. However, for the third kind of problem, the above results do not hold
generally. We also analyze the regularization of the other two Krylov solvers
LSMR and CGME, proving that LSMR has similar regularizing effects to LSQR for
each kind of problem and both are superior to CGME. Numerical experiments
confirm our theory on LSQR.


title:
The Goldstino Brane, the Constrained Superfields and Matter in N=1
  Supergravity

abstract:
  We show that different (brane and constrained superfield) descriptions for
the Volkov-Akulov goldstino coupled to N=1, D=4 supergravity with matter
produce similar wide classes of models with spontaneously broken local
supersymmetry and discuss the relation between the different formulations. As
with the formulations with irreducible constrained superfields, the geometric
goldstino brane approach has the advantage of being manifestly off-shell
supersymmetric without the need to introduce auxiliary fields. It provides an
explicit solution of the nilpotent superfield constraints and avoids issues
with non-Gaussian integration of auxiliary fields. We describe general
couplings of the supersymmetry breaking sector, including the goldstino and
other non-supersymmetric matter, to supergravity and matter supermultiplets.
Among various examples, we discuss a goldstino brane contribution to the
gravitino mass term and the supersymmetrization of the anti-D3-brane
contribution to the effective theory of type IIB warped flux compactifications.


title:
Anomalous Conductance of a strongly interacting Fermi Gas through a
  Quantum Point Contact

abstract:
  In this work we study the particle conductance of a strongly interacting
Fermi gas through a quantum point contact. With an atom-molecule two-channel
model, we compute the contribution to particle conductance by both the
fermionic atoms and the bosonic molecules using the Keldysh formalism. Focusing
on the regime above the Fermi superfluid transition temperature, we find that
the fermionic contribution to the conductance is reduced by interaction
compared with the quantized value for the non-interacting case; while the
bosonic contribution to the conductance exhibits a plateau with non-universal
values that is larger than the quantized conductance. This feature is
particularly profound at temperature close to the superfluid transition. We
emphasize that the enhanced conductance arises because of the bosonic nature of
closed channel molecules and the low-dimensionality of the quantum point
contact.


title:
Mining of health and disease events on Twitter: validating search
  protocols within the setting of Indonesia

abstract:
  This study seeks to validate a search protocol of ill health-related terms
using Twitter data which can later be used to understand if, and how, Twitter
can reveal information on the current health situation. We extracted
conversations related to health and disease postings on Twitter using a set of
pre-defined keywords, assessed the prevalence, frequency, and timing of such
content in these conversations, and validated how this search protocol was able
to detect relevant disease tweets. Classification and Regression Trees (CART)
algorithm was used to train and test search protocols of disease and health
hits comparing to those identified by our team. The accuracy of predictions
showed a good validity with AUC beyond 0.8. Our study shows that monitoring of
public sentiment on Twitter can be used as a real-time proxy for health events.


title:
Magnetic instability and $f-d$ hybridization in CeFe$_2$ on substituting
  Cr, Ag and Au for Fe

abstract:
  Hybridization between Ce $f$ and conduction $d$ states has been speculatively
known to be one of the mechanisms responsible for magnetic instability of the
ferromagnetic ground state of CeFe$_2$. Substituting Fe by small amounts of
certain elements stabilizes it to an antiferromagnetic state below the Curie
temperature via a first-order second phase transition. In the present work, we
seek any direct relation between the $f-d$ hybridization and the second
transition by measuring primarily dc magnetization and Ce M$_{4,5}$ edge x-ray
absorption spectra of Ce(Fe$_{1-x}$M$_x$)$_2$ pseudobinaries, with M = Cr, Ag
and Au. X-ray diffraction and x-ray photoelectron spectroscopy measurements are
also performed essentially to monitor the quality of the samples. Whereas Cr
impurity is found to cause the second transition, Ag and Au apparently do not
induce any. In the former, the Curie and second transition temperatures vary
systematically, but differently, with $x$. Our results imply that there is a
definite proportionality between the $x$ dependences of the second transition
temperature and the $f-d$ hybridization strength estimated qualitatively from
the absorption spectra.


title: Canonical lifts of families of elliptic curves

abstract:
  We show that the canonical-lift construction for ordinary elliptic curves
over perfect fields of characteristic $p>0$ extends uniquely to arbitrary
families of ordinary elliptic curves, even over $p$-adic formal schemes. In
particular, the universal ordinary elliptic curve has a canonical lift. The
existence statement is largely a formal consequence of the universal property
of Witt vectors applied to the moduli space of ordinary elliptic curves, at
least with enough level structure. As an application, we show how this point of
view allows for more formal proofs of recent results of Finotti and
Erdo\u{g}an.


title: The Adequate Bootstrap

abstract:
  There is a fundamental disconnect between what is tested in a model adequacy
test, and what we would like to test. The usual approach is to test the null
hypothesis "Model M is the true model." However, Model M is never the true
model. A model might still be useful even if we have enough data to reject it.
In this paper, we present a technique to assess the adequacy of a model from
the philosophical standpoint that we know the model is not true, but we want to
know if it is useful.
  Our solution to this problem is to measure the parameter uncertainty in our
estimates caused by the model uncertainty. We use bootstrap inference on
samples of a smaller size, for which the model cannot be rejected. We use a
model adequacy test to choose a bootstrap size with limited probability of
rejecting the model and perform inference for samples of this size based on a
nonparametric bootstrap. Our idea is that if we base our inference on a sample
size at which we do not reject the model, then we should be happy with this
inference, because we would have been confident in it if our original dataset
had been this size.


title: Dynamics of Active Rouse Chains

abstract:
  We consider how active forces modeled as non-thermal random noise affect the
average dynamical properties of a Rouse polymer. As the power spectrum of the
noise is not known we keep the analytical treatment as generic as possible and
then present results for a few examples of active noise. We discuss the
connection between our results and recent experimental studies of dynamics of
labeled DNA telomeres in living cells, and propose new chromatin tracking
experiments that will allow one to determine the statistical properties of the
active forces associated with chromatin remodeling processes.


title: On the algebraic structure of Killing superalgebras

abstract:
  We study the algebraic structure of the Killing superalgebra of a
supersymmetric background of $11$-dimensional supergravity and show that it is
isomorphic to a filtered deformation of a $\mathbb Z$-graded subalgebra of the
Poincar\'e superalgebra. We are able to map the classification problem for
highly supersymmetric backgrounds (i.e., those which preserve more than half
the supersymmetry) to the classification problem of a certain class of filtered
deformations of graded subalgebras of the Poincar\'e superalgebra. We show that
one can reconstruct a highly supersymmetric background from its Killing
superalgebra; in so doing, we relate the bosonic field equations of
$11$-dimensional supergravity to the Jacobi identity of the Killing
superalgebra and show in this way that preserving more than half the
supersymmetry implies the bosonic field equations.


title:
Neural Networks and Chaos: Construction, Evaluation of Chaotic Networks,
  and Prediction of Chaos with Multilayer Feedforward Networks

abstract:
  Many research works deal with chaotic neural networks for various fields of
application. Unfortunately, up to now these networks are usually claimed to be
chaotic without any mathematical proof. The purpose of this paper is to
establish, based on a rigorous theoretical framework, an equivalence between
chaotic iterations according to Devaney and a particular class of neural
networks. On the one hand we show how to build such a network, on the other
hand we provide a method to check if a neural network is a chaotic one.
Finally, the ability of classical feedforward multilayer perceptrons to learn
sets of data obtained from a dynamical system is regarded. Various Boolean
functions are iterated on finite states. Iterations of some of them are proven
to be chaotic as it is defined by Devaney. In that context, important
differences occur in the training process, establishing with various neural
networks that chaotic behaviors are far more difficult to learn.


title:
Self-Adaptive Trade-off Decision Making for Autoscaling Cloud-Based
  Services

abstract:
  Elasticity in the cloud is often achieved by on-demand autoscaling. In such
context, the goal is to optimize the Quality of Service (QoS) and cost
objectives for the cloud-based services. However, the difficulty lies in the
facts that these objectives, e.g., throughput and cost, can be naturally
conflicted, and the QoS of cloud-based services often interfere due to the
shared infrastructure in cloud. Consequently, dynamic and effective trade-off
decision making of autoscaling in the cloud is necessary, yet challenging. In
particular, it is even harder to achieve well-compromised trade-offs, where the
decision largely improves the majority of the objectives, while causing
relatively small degradations to others. In this paper, we present a
self-adaptive decision making approach for autoscaling in the cloud. It is
capable to adaptively produce autoscaling decisions that lead to
well-compromised trade-offs without heavy human intervention. We leverage on
ant colony inspired multi-objective optimization for searching and optimizing
the trade-offs decisions, the result is then filtered by compromise-dominance,
a mechanism that extracts the decisions with balanced improvements in the
trade-offs. We experimentally compare our approach to four state-of-the-arts
autoscaling approaches: rule, heuristic, randomized and multi-objective genetic
algorithm based solutions. The results reveal the effectiveness of our approach
over the others, including better quality of trade-offs and significantly
smaller violation of the requirements.


title: On several kinds of sums of balancing numbers

abstract:
  The balancing numbers $B_n$ ($n=0,1,\cdots$) are solutions of the binary
recurrence $B_n=6B_{n-1}-B_{n-2}$ ($n\ge 2$) with $B_0=0$ and $B_1=1$. In this
paper we show several relations about the sums of product of two balancing
numbers of the type $\sum_{m=0}^n B_{k m+r}B_{k(n-m)+r}$ ($k>r\ge 0$) and the
alternating sum of reciprocal of balancing numbers
$\left\lfloor\left(\sum_{k=n}^\infty\frac{1}{B_{l
k}}\right)^{-1}\right\rfloor$. Similar results are also obtained for
Lucas-balancing numbers $C_n$ ($n=0,1,\cdots$), satisfying the binary
recurrence $C_n=6C_{n-1}-C_{n-2}$ ($n\ge 2$) with $C_0=1$ and $C_1=3$. Some
binomial sums involving these numbers are also explored.


title: Emergent Inter-particle Interactions in Thermal Amorphous Solids

abstract:
  Amorphous media at finite temperatures, be them liquids, colloids or glasses,
are made of interacting particles that move chaotically due to thermal energy,
colliding and scattering continuously off each other. When the average
configuration in these systems relaxes only at long times, one can introduce
{\em effective interactions} that keep the {\em mean positions} in mechanical
equilibrium. We introduce a new framework to determine these effective
force-laws that define an effective Hessian that can be employed to discuss
stability properties and density of states of the amorphous system. We
exemplify the approach with a thermal glass of hard spheres; these feel zero
forces when not in contact and infinite forces when they touch. The present
approach recaptures the effective interactions which for sufficiently dense
spheres at temperature $T$ depends on the gap $h$ between spheres as $T/h$ [C.
Brito and M. Wyart, Europhys. Lett. 76 149 (2006)]. In systems at lower
densities or with longer microscopic interaction (say like Lennard-Jones), the
emergent force laws will include ternary, quaternary and generally higher order
many-body terms, even if the microscopic interactions are strictly binary.


title: A Topological Study of Chaotic Iterations. Application to Hash Functions

abstract:
  Chaotic iterations, a tool formerly used in distributed computing, has
recently revealed various interesting properties of disorder leading to its use
in the computer science security field. In this paper, a comprehensive study of
its topological behavior is proposed. It is stated that, in addition to being
chaotic as defined in the Devaney's formulation, this tool possesses the
property of topological mixing. Additionally, its level of sensibility,
expansivity, and topological entropy are evaluated. All of these properties
lead to a complete unpredictable behavior for the chaotic iterations. As it
only manipulates binary digits or integers, we show that it is possible to use
it to produce truly chaotic computer programs. As an application example, a
truly chaotic hash function is proposed in two versions. In the second version,
an artificial neural network is used, which can be stated as chaotic according
to Devaney.


title:
Probabilistic Knowledge Graph Construction: Compositional and
  Incremental Approaches

abstract:
  Knowledge graph construction consists of two tasks: extracting information
from external resources (knowledge population) and inferring missing
information through a statistical analysis on the extracted information
(knowledge completion). In many cases, insufficient external resources in the
knowledge population hinder the subsequent statistical inference. The gap
between these two processes can be reduced by an incremental population
approach. We propose a new probabilistic knowledge graph factorisation method
that benefits from the path structure of existing knowledge (e.g. syllogism)
and enables a common modelling approach to be used for both incremental
population and knowledge completion tasks. More specifically, the probabilistic
formulation allows us to develop an incremental population algorithm that
trades off exploitation-exploration. Experiments on three benchmark datasets
show that the balanced exploitation-exploration helps the incremental
population, and the additional path structure helps to predict missing
information in knowledge completion.


title: Nonminimal coupling and inflationary attractors

abstract:
  We show explicitly how the T model, E model, and Hilltop inflations are
obtained from the general scalar-tensor theory of gravity with arbitrary
conformal factors in the strong coupling limit. We argue that $\xi$ attractors
can give any observables $n_s$ and $r$ by this method. The existence of
attractors imposes a challenge to distinguish different models.


title:
Managing The Dynamics Of A Harmonic Potential Field-Guided Robot In A
  Cluttered Environment

abstract:
  This paper demonstrates the ability of the harmonic potential field, HPF,
planning method to generate a well-behaved constrained path for a robot with
second order dynamics in a cluttered environment. It is shown that HPF-based
controllers may be developed for holonomic as well as nonholonomic robots to
effectively suppress the effect of inertial forces on the robot trajectory
while maintaining all the attractive features of a purely kinematic HPF
planner. The capabilities of the suggested navigation controller are
demonstrated using simulation results. Comparisons are also supplied with other
approaches used for converting the guidance signal from a purely kinematic HPF
planner into a navigation control signal.


title: Congruences and Concurrent Lines in Multi-View Geometry

abstract:
  We present a new framework for multi-view geometry in computer vision. A
camera is a mapping between $\mathbb{P}^3$ and a line congruence. This model,
which ignores image planes and measurements, is a natural abstraction of
traditional pinhole cameras. It includes two-slit cameras, pushbroom cameras,
catadioptric cameras, and many more. We study the concurrent lines variety,
which consists of $n$-tuples of lines in $\mathbb{P}^3$ that intersect at a
point. Combining its equations with those of various congruences, we derive
constraints for corresponding images in multiple views. We also study
photographic cameras which use image measurements and are modeled as rational
maps from $\mathbb{P}^3$ to $\mathbb{P}^2$ or $\mathbb{P}^1\times
\mathbb{P}^1$.


title: Higher-order identities for balancing numbers

abstract:
  Let $B_n$ be the $n$-th balancing number. In this paper, we give some
explicit expressions of $\sum_{l=0}^{2 r-3}(-1)^l\binom{2
r-3}{l}\sum_{j_1+\cdots+j_r=n-2 l\atop j_1,\dots,j_r\ge 1}B_{j_1}\cdots
B_{j_r}$ and $\sum_{j_1+\cdots+j_r=n\atop j_1,\dots,j_r\ge 1}B_{j_1}\cdots
B_{j_r}$. We also consider the convolution identities with binomial
coefficients: $$ \sum_{k_1+\cdots+k_r=n\atop k_1,\dots,k_r\ge
1}\binom{n}{k_1,\dots,k_r}B_{k_1}\cdots B_{k_r} $$ This type can be
generalized, so that $B_n$ is a special case of the number $u_n$, where $u_n=a
u_{n-1}+b u_{n-2}$ ($n\ge 2$) with $u_0=0$ and $u_1=1$.


title:
Bridging Ecology and Cloud: Transposing Ecological Prespective to Enable
  Better Cloud Autoscaling

abstract:
  Elastic autoscaling is the fundamental mechanism that enables the cloud-based
services to continually evolve themselves - through changing the related
software configurations and hardware resource provisions - under time-varying
workloads. However, given the increasingly complex dynamic, uncertainty and
trade-offs related to the runtime QoS and cost/energy of services, cloud
autoscaling system is becoming one of the most complex artifacts constructed by
human and thus its effectiveness is difficult to be preserved. In this article,
we present novel ideas for facilitating cloud autoscaling. Our hypothesis that
cloud ecosystem, represented by a collection of cloud-based services, bears
many similarities with the natural ecosystem. As such, we in- tend to
investigate how ecological view can be adopted to better explain how the
cloud-based services evolve, and to explore what are the key factors that drive
stable and sustainable cloud-based services in the cloud. To achieve this goal,
we aim to transpose ecological principles, theories and models into cloud
autoscaling analogues and spontaneously improve long-term stability and
sustainability of cloud ecosystem.


title:
Expressing the statement of the Feit-Thompson theorem with diagrams in
  the category of finite groups

abstract:
  We reformulate the statement of the Feit-Thompson theorem in terms of
diagrams in the category of finite groups, namely iterations of the Quillen
lifting property with respect to particular morphisms.


title: Quality Analysis of a Chaotic Proven Keyed Hash Function

abstract:
  Hash functions are cryptographic tools, which are notably involved in
integrity checking and password storage. They are of primary importance to
improve the security of exchanges through the Internet. However, as security
flaws have been recently identified in the current standard in this domain, new
ways to hash digital data must be investigated. In this document an original
keyed hash function is evaluated. It is based on asynchronous iterations
leading to functions that have been proven to be chaotic. It thus possesses
various topological properties as uniformity and sensibility to its initial
condition. These properties make our hash function satisfies established
security requirements in this field. This claim is qualitatively proven and
experimentally verified in this research work, among other things by realizing
a large number of simulations.


title:
Invariances of the operator properties of frame multipliers under
  perturbations of frames and symbol

abstract:
  Let $\Phi$ and $\Psi$ be frames for $\cal H$ and let $M_{m,\Phi,\Psi}$ be a
frame multiplier with the symbol $m$. In this paper, we restrict our
investigation to show that the operator properties of $M_{m,\Phi,\Psi}$ are
stable under the perturbations of $\Phi$, $\Psi$ and $m$. Also, special
attention is devoted to the study of invertible frame multipliers. These
results are not only of interest in their own right, but also they pave the way
for obtaining some new results for Gabor multipliers which have been studied
mostly by Hans Georg Feichtinger and his coauthors in recent years.


title:
FPGA Design for Pseudorandom Number Generator Based on Chaotic Iteration
  used in Information Hiding Application

abstract:
  Lots of researches indicate that the inefficient generation of random numbers
is a significant bottleneck for information communication applications.
Therefore, Field Programmable Gate Array (FPGA) is developed to process a
scalable fixed-point method for random streams generation. In our previous
researches, we have proposed a technique by applying some well-defined discrete
chaotic iterations that satisfy the reputed Devaney's definition of chaos,
namely chaotic iterations (CI). We have formerly proven that the generator with
CI can provide qualified chaotic random numbers. In this paper, this generator
based on chaotic iterations is optimally redesigned for FPGA device. By doing
so, the generation rate can be largely improved. Analyses show that these
hardware generators can also provide good statistical chaotic random bits and
can be cryptographically secure too. An application in the information hiding
security field is finally given as an illustrative example.


title: Planning With Discrete Harmonic Potential Fields

abstract:
  In this work a discrete counterpart to the continuous harmonic potential
field approach is suggested. The extension to the discrete case makes use of
the strong relation HPF-based planning has to connectionist artificial
intelligence (AI). Connectionist AI systems are networks of simple,
interconnected processors running in parallel within the confines of the
environment in which the planning action is to be synthesized. It is not hard
to see that such a paradigm naturally lends itself to planning on weighted
graphs where the processors may be seen as the vertices of the graph and the
relations among them as its edges. Electrical networks are an effective
realization of connectionist AI. The utility of the discrete HPF (DHPF)
approach is demonstrated in three ways. First, the capability of the DHPF
approach to generate new, abstract, planning techniques is demonstrated by
constructing a novel, efficient, optimal, discrete planning method called the
M* algorithm. Also, its ability to augment the capabilities of existing
planners is demonstrated by suggesting a generic solution to the lower bound
problem faced by the A* algorithm. The DHPF approach is shown to be useful in
solving specific planning problems in communication. It is demonstrated that
the discrete HPF paradigm can support routing on-the-fly while the network is
still in a transient state. It is shown by simulation that if a path to the
target always exist and the switching delays in the routers are negligible, a
packet will reach its destination despite the changes in the network which may
simultaneously take place while the packet is being routed.


title:
An Ocean Drum: quasi-geostrophic energetics from a Riemann geometry
  perspective

abstract:
  We revisit the discussion of the energetics of quasi-geostrophic flows from a
geometric perspective based on the introduction of an effective metric, built
in terms of the flow stratification and the Coriolis parameter. In particular,
an appropriate notion of normal modes is defined through a spectral geometry
problem in the ocean basin (a compact manifold with boundary) for the
associated Laplace-Beltrami scalar operator. This spectral problem can be used
to systematically encode non-local aspects of stratification and topography. As
examples of applications we revisit the isotropy assumption in geostrophic
turbulence, identify (a patch of) the hyperbolic space $\mathbb{H}^3$ as the
leading-order term in the effective geometry for the deep mesoscale ocean and,
finally, discuss some diagnostic tools based on a simple statistical mechanics
toy-model to be used in numerical simulations and/or observations of
quasi-geostrophic flows.

categories: physics.flu-dyn cond-mat.stat-mech gr-qc math-ph math.MP


title: Detecting ultralight axion dark matter wind with laser interferometers

abstract:
  The ultralight axion with mass around $10^{-22}$ eV is known as a candidate
of dark matter. A peculiar feature of the ultralight axion is oscillating
pressure in time, which produces oscillation of gravitational potentials. Since
the solar system moves through the dark matter halo at the velocity of about $v
\sim 300 \, \text{km} / \text{s} = 10^{-3}$, there exists axion wind, which
looks like scalar gravitational waves for us. Hence, there is a chance to
detect ultralight axion dark matter with a wide mass range by using laser
interferometer detectors. We calculate the detector signal induced by the
oscillating pressure of the ultralight axion field, which would be detected by
future laser interferometer experiments. We also argue that the detector signal
can be enhanced due to the resonance in modified gravity theory explaining the
dark energy.


title:
Spatial Modeling of Oil Exploration Areas Using Neural Networks and
  ANFIS in GIS

abstract:
  Exploration of hydrocarbon resources is a highly complicated and expensive
process where various geological, geochemical and geophysical factors are
developed then combined together. It is highly significant how to design the
seismic data acquisition survey and locate the exploratory wells since
incorrect or imprecise locations lead to waste of time and money during the
operation. The objective of this study is to locate high-potential oil and gas
field in 1: 250,000 sheet of Ahwaz including 20 oil fields to reduce both time
and costs in exploration and production processes. In this regard, 17 maps were
developed using GIS functions for factors including: minimum and maximum of
total organic carbon (TOC), yield potential for hydrocarbons production (PP),
Tmax peak, production index (PI), oxygen index (OI), hydrogen index (HI) as
well as presence or proximity to high residual Bouguer gravity anomalies,
proximity to anticline axis and faults, topography and curvature maps obtained
from Asmari Formation subsurface contours. To model and to integrate maps, this
study employed artificial neural network and adaptive neuro-fuzzy inference
system (ANFIS) methods. The results obtained from model validation demonstrated
that the 17x10x5 neural network with R=0.8948, RMS=0.0267, and kappa=0.9079 can
be trained better than other models such as ANFIS and predicts the potential
areas more accurately. However, this method failed to predict some oil fields
and wrongly predict some areas as potential zones.


title: Outer Disk Star Formation in HI selected Galaxies

abstract:
  The HI in galaxies often extends past their conventionally defined optical
extent. I report results from our team which has been probing low intensity
star formation in outer disks using imaging in H-alpha and ultraviolet. Using a
sample of hundreds of HI selected galaxies, we confirm that outer disk HII
regions and extended UV disks are common. Hence outer disks are not dormant but
are dimly forming stars. Although the ultraviolet light in galaxies is more
centrally concentrated than the HI, the UV/HI ratio (the Star Formation
Efficiency) is nearly constant, with a slight dependency on surface brightness.
This result is well accounted for in a model where disks maintain a constant
stability parameter Q. This model also accounts for how the ISM and star
formation are distributed in the bright parts of galaxies, and how HI appears
to trace the distribution of dark matter in galaxy outskirts.


title: Two Security Layers for Hierarchical Data Aggregation in Sensor Networks

abstract:
  Due to resource restricted sensor nodes, it is important to minimize the
amount of data transmission among sensor networks. To reduce the amount of
sending data, an aggregation approach can be applied along the path from
sensors to the sink. However, as sensor networks are often deployed in
untrusted and even hostile environments, sensor nodes are prone to node
compromise attacks. Hence, an end-to-end secure aggregation approach is
required to ensure a healthy data reception. In this paper, we propose two
layers for secure data aggregation in sensor networks. Firstly, we provide an
end-to-end encryption scheme that supports operations over cypher-text. It is
based on elliptic curve cryptography that exploits a smaller key size, allows
the use of higher number of operations on cypher-texts, and prevents the
distinction between two identical texts from their cryptograms. Secondly, we
propose a new watermarking-based authentication that enables sensor nodes to
ensure the identity of other nodes they are communicating with. Our experiments
show that our hybrid approach of secure data aggregation enhances the security,
significantly reduces computation and communication overhead, and can be
practically implemented in on-the-shelf sensor platforms.


title: Spin correlation functions and quasiparticle decay

abstract:
  We study one-dimensional anisotropic XXZ spin-$\frac12$ model with
ferromagnetic sign of the coupling and $z-z$ exchange constant $J_z = \Delta
J$, where $\Delta < 1$, and $J$ is the coupling within XY spin plane. We
calculate damping of low-energy excitations with $\omega \ll T $ due to their
scattering from thermal excitation bath with temperature $T \ll J$, taking into
account nonzero curvature of the excitation spectrum, $\epsilon(q) = u q +
\delta\epsilon(q)$. We calculate also longitudinal spin-spin correlation
function $\langle S^z(x,t)S^z(0,0) \rangle$ at $x \approx ut$ and find the
shape of the spreading "wave packet".


title:
On smoothing singularities of elliptic orbital integrals on GL(n) and
  Beyond Endoscopy

abstract:
  Recent work of Altu\u{g} continues the preliminary analysis of Langlands'
Beyond Endoscopy proposal for $GL(2)$ by removing the contribution of the
trivial representation to the trace formula using a Poisson summation formula.
We show that Altu\u{g}'s method of smoothing real elliptic orbital integrals by
an approximate functional equation extends to $GL(n)$. We also discuss the case
of an arbitrary reductive group, and remaining obstructions for applying
Poisson summation.


title: Compactifications of Adjoint Orbits and their Hodge Diamonds

abstract:
  A recent theorem of [GGSM1] showed that adjoint orbits of semisimple Lie
algebras have the structure of symplectic Lefschetz fibrations. We investigate
the behaviour of their fibrewise compactifications. Expressing adjoint orbits
and fibres as affine varieties in their Lie algebra, we compactify them to
projective varieties via homogenisation of the defining ideals. We find that
their Hodge diamonds vary wildly according to the choice of homogenisation, and
that extensions of the potential to the compactification must acquire
degenerate singularities.


title: Eternal Family Trees and Dynamics on Unimodular Random Graphs

abstract:
  This paper is centered on covariant dynamics on unimodular random graphs and
random networks, namely maps from the set of vertices to itself which are
preserved by graph or network isomorphisms. Such dynamics are referred to as
vertex-shifts here. The first result of the paper is a classification of
vertex-shifts on unimodular random networks. Each such vertex-shift partitions
the vertices into a collection of connected components and foils. The latter
are discrete analogues the stable manifold of the dynamics. The classification
is based on the cardinality of the connected components and foils. Up to an
event of zero probability, there are three classes of foliations in a connected
component: F/F (with finitely many finite foils), I/F (infinitely many finite
foils), and I/I (infinitely many infinite foils). An infinite connected
component of the graph of a vertex-shift on a random network forms an infinite
tree with one selected end which is referred to as an Eternal Family Tree. Such
trees can be seen as stochastic extensions of branching processes. Unimodular
Eternal Family Trees can be seen as extensions of critical branching processes.
The class of offspring-invariant Eternal Family Trees, which is introduced in
the paper, allows one to analyze dynamics on networks which are not necessarily
unimodular. These can be seen as extensions of non-necessarily critical
branching processes. Several construction techniques of Eternal Family Trees
are proposed, like the joining of trees or moving the root to a far descendant.
Eternal Galton-Watson Trees and Eternal Multi-type Galton-Watson Trees are also
introduced as special cases of Eternal Family Trees satisfying additional
independence properties. These examples allow one to show that the results on
Eternal Family Trees unify and extend to the dependent case several well known
theorems of the literature on branching processes.


title: Uniqueness of the Fock quantization of Dirac fields in 2+1 dimensions

abstract:
  We study the Fock quantization of a free Dirac field in 2+1-dimensional
backgrounds which are conformally ultrastatic, with a time-dependent conformal
factor. As it is typical for field theories, there is an infinite ambiguity in
the Fock representation of the canonical anticommutation relations. Different
choices may lead to unitarily inequivalent theories that describe different
physics. To remove this ambiguity one usually requires that the vacuum be
invariant under the unitary transformations that implement the symmetries of
the equations of motion. However, in non-stationary backgrounds, where time
translation is not a symmetry transformation, the requirement of vacuum
invariance is in general not enough to fix completely the Fock representation.
We show that this problem is overcome in the considered scenario by demanding,
in addition, a unitarily implementable quantum dynamics. The combined
imposition of these conditions selects a unique family of equivalent Fock
representations. Moreover, one also obtains an essentially unique splitting of
the time variation of the Dirac field into an explicit dependence on the
background scale factor and a quantum evolution of the corresponding creation
and annihilation operators.


title: A constructive approach to a conjecture by Voskresenskii

abstract:
  Voskresenskii conjectured that stably rational tori are rational. Klyachko
proved this assertion for a wide class of tori by general principles. We
re-prove Klyachko's result by providing simple explicit birational
isomorphisms, and elaborate on some links to torus-based cryptography.


title: Conformal vector fields on Lie groups

abstract:
  In this paper, we investigated the behavior of left-invariant conformal
vector fields on Lie groups with left-invariant pseudo-Riemannian metrics.
First of all, we prove that conformal vector fields on pseudo-Riemannian
unimodular Lie groups are Killing. Then we obtain a necessary condition for a
pseudo-Rimennian non-unimodular Lie group admitting a non-Killing conformal
vector field. Finally, we give examples of non-Killing conformal vector fields
and Yamabe solitons on non-unimodular Lorentzian Lie groups based on the above
study.


title: New examples of maximal surfaces in Loretnz-Minkowski space

abstract:
  We use the Bj\"orling problem in Lorentz-Minkowski space to obtain explicit
parametrizations of maximal surfaces containing a circle and a helix. We
investigate the Weierstrass representation of these surfaces.


title:
Theoretical design and circuit implementation of integer domain chaotic
  systems

abstract:
  In this paper, a new approach for constructing integer domain chaotic systems
(IDCS) is proposed, and its chaotic behavior is mathematically proven according
to the Devaney's definition of chaos. Furthermore, an analog-digital hybrid
circuit is also developed for realizing the designed basic IDCS. In the IDCS
circuit design, chaos generation strategy is realized through a sample-hold
circuit and a decoder circuit so as to convert the uniform noise signal into a
random sequence, which plays a key role in circuit implementation. The
experimental observations further validate the proposed systematic methodology
for the first time.


title:
Enhancing a slow and weak optomechanical nonlinearity with delayed
  quantum feedback

abstract:
  One of the central goals of quantum optics is to generate large interactions
between single photons. Light interacting with motion in an optomechanical
system can sense minute fluctuations in displacement, and also impart a force
via radiation pressure. Taken together, these two effects mean that two photons
can "sense" each other's presence in an interaction mediated by motion. It is
accepted that for an optomechanical system to mediate strong interactions
between single photons, the mechanical system must respond before the photon is
lost ($\omega_m > \kappa$), and the radiation pressure force must generate a
displacement large enough to change the optical properties of the system ($g_0
> \kappa$). The challenge of achieving this "vacuum strong coupling" has
prevented experiments from demonstrating single-photon interactions. In this
work we show that by adding a coherent feedback channel to a slow mechanical
system ($\omega_m < \kappa$) that is weakly nonlinear ($g_0 < \kappa$), two
spatially separated single photons can be made to effectively interact with
each other deterministically through the mechanical motion of a resonator. To
numerically analyze our system, we must solve Schr\"odinger's equation for the
state of an optomechanical system coupled to a long waveguide feeback channel.
We implement a matrix product state approach to keep track of and evolve the
complete quantum state of the system in an efficient way. We analyze the
process semiclassically and then solve the full quantum dynamics numerically to
find a cross-over between the semiclassical and quantum regimes of
optomechanics. Finally we analyze the experimental prospects for implementing
this protocol.


title: Hybrid Models in Loop Quantum Cosmology

abstract:
  In the framework of Loop Quantum Cosmology, inhomogeneous models are usually
quantized by means of a hybrid approach that combines loop quantization
techniques with standard quantum field theory methods. This approach is based
on a splitting of the phase space in a homogeneous sector, formed by global,
zero-modes, and an inhomogeneous sector, formed by the remaining, infinite
number of modes, that describe the local degrees of freedom. Then, the hybrid
quantization is attained by adopting a loop representation for the homogeneous
gravitational sector, while a Fock representation is used for the
inhomogeneities. The zero-mode of the Hamiltonian constraint operator couples
the homogeneous and inhomogeneous sectors. The hybrid approach, therefore, is
expected to provide a suitable quantum theory in regimes where the main quantum
effects of the geometry are those affecting the zero-modes, while the
inhomogeneities, still being quantum, can be treated in a more conventional
way. This hybrid strategy was first proposed for the simplest cosmological
midisuperspaces: the Gowdy models, and it has been later applied to the case of
cosmological perturbations. This paper reviews the construction and main
applications of hybrid Loop Quantum Cosmology


title: On geometry of deformed black holes: I. Majumdar-Papapetrou binary

abstract:
  Although black holes are eminent manifestations of very strong gravity, the
geometry of space-time around and even inside them can be significantly
affected by additional bodies present in their surroundings. We study such an
influence within static and axially symmetric (electro-)vacuum space-times
described by exact solutions of Einstein's equations, considering
astrophysically motivated configurations (such as black holes surrounded by
rings) as well as those of pure academic interest (such as specifically "tuned"
systems of multiple black holes). The geometry is represented by the simplest
invariants determined by the metric (the lapse function) and its gradient
(gravitational acceleration), with special emphasis given to curvature (the
Kretschmann and Ricci-square scalars). These quantities are analyzed and their
level surfaces plotted both above and below the black-hole horizons, in
particular near the central singularities. Estimating that the black hole could
be most strongly affected by the other black hole, we focus, in this first
paper, on the Majumdar--Papapetrou solution for a binary black hole and compare
the deformation caused by "the other" hole (and the electrostatic field) with
that induced by rotational dragging in the well-known Kerr and Kerr--Newman
solutions.


title: Distributed Representations for Biological Sequence Analysis

abstract:
  Biological sequence comparison is a key step in inferring the relatedness of
various organisms and the functional similarity of their components. Thanks to
the Next Generation Sequencing efforts, an abundance of sequence data is now
available to be processed for a range of bioinformatics applications. Embedding
a biological sequence over a nucleotide or amino acid alphabet in a lower
dimensional vector space makes the data more amenable for use by current
machine learning tools, provided the quality of embedding is high and it
captures the most meaningful information of the original sequences. Motivated
by recent advances in the text document embedding literature, we present a new
method, called seq2vec, to represent a complete biological sequence in an
Euclidean space. The new representation has the potential to capture the
contextual information of the original sequence necessary for sequence
comparison tasks. We test our embeddings with protein sequence classification
and retrieval tasks and demonstrate encouraging outcomes.


title: High-performance graphene photodetector by interfacial gating

abstract:
  Graphene based photo-detecting has received great attentions and the
performance of such detector is stretching to both ends of high sensitivity and
ultra-fast response. However, limited by the current photo-gating mechanism,
the price for achieving ultra-high sensitivity is sacrificing the response
time. Detecting weak signal within short response time is crucial especially in
applications such as optical positioning, remote sensing, and biomedical
imaging. In this work, we bridge the gap between ultra-fast response and
ultra-high sensitivity by employing a graphene/SiO2/lightly-doped-Si
architecture with revolutionary interfacial gating mechanism. Such device is
capable to detect < 1 nW signal (with responsivity of ~1000 A W-1) and the
spectral response extends from visible to near-infrared. More importantly, the
photoresponse time of our device has been pushed to ~400 ns. The current device
structure does not need complicated fabrication process and is fully compatible
with the silicon technology. This work will not only open up a route to
graphene-based high performance optoelectronic devices, but also have great
potential in ultra-fast weak signal detection.


title:
Epidemiological Approach for Data Survivability in Unattended Wireless
  Sensor Networks

abstract:
  Unattended Wireless Sensor Networks (UWSNs) are Wireless Sensor Networks
characterized by sporadic sink presence and operation in hostile settings. The
absence of the sink for period of time, prevents sensor nodes to offload data
in real time and offer greatly increased opportunities for attacks resulting in
erasure, modification, or disclosure of sensor-collected data. In this paper,
we focus on UWSNs where sensor nodes collect and store data locally and try to
upload all the information once the sink becomes available. One of the most
relevant issues pertaining UWSNs is to guarantee a certain level of information
survivability in an unreliable network and even in presence of a powerful
attackers. In this paper, we first introduce an epidemic-domain inspired
approach to model the information survivability in UWSN. Next, we derive a
fully distributed algorithm that supports these models and give the correctness
proofs.


title:
Coexistence of antiferromagnetic and ferromagnetic spin correlations in
  Ca(Fe1-xCox)2As2 revealed by 75As nuclear magnetic resonance

abstract:
  Recent nuclear magnetic resonance (NMR) measurements revealed the coexistence
of stripe-type antiferromagnetic (AFM) and ferromagnetic (FM) spin correlations
in both the hole- and electron-doped BaFe$_2$As$_2$ families of iron-pnictide
superconductors by a Korringa ratio analysis. Motivated by the NMR work, we
investigate the possible existence of FM fluctuations in another iron pnictide
superconducting family, Ca(Fe$_{1-x}$Co$_x$)$_2$As$_2$. We re-analyzed our
previously reported data in terms of the Korringa ratio and found clear
evidence for the coexistence of stripe-type AFM and FM spin correlations in the
electron-doped CaFe$_2$As$_2$ system. These NMR data indicate that FM
fluctuations exist in general in iron-pnictide superconducting families and
thus must be included to capture the phenomenology of the iron pnictides.


title: On the static Casimir effect with parity-breaking mirrors

abstract:
  We study the Casimir interaction energy due to the vacuum fluctuations of the
Electromagnetic (EM) field in the presence of two mirrors, described by
$2+1$-dimensional, generally nonlocal actions, which may contain both
parity-conserving and parity-breaking terms. We compare the results with the
ones corresponding to Chern-Simons boundary conditions, and evaluate the
interaction energy for several particular situations.


title: Causality in thermoelectric systems: Insights from block diagrams

abstract:
  While Carnot's model engines demonstrate ideal performances regarding
conversion efficiency, they cannot be actually used as energy converters since
they are non causal systems. Such an unphysical behavior indeed restrains the
working conditions to a single point where, in the case of a refrigerator
(generator), the cooling power (output power) vanishes. Focusing on the example
of a thermoelectric refrigerator, we study the impact of different dissipation
sources on the causality of such systems. Basing our analysis on the block
diagram description of this system, we discuss particularly the fact that heat
conduction cannot ensure causality.


title: Some Characterizations for Composition Operators on the Fock Space

abstract:
  We study composition operators on the Fock spaces
$\mathcal{F}^2_\alpha(\mathbb{C}^n)$, problems considered include the essential
norm, normality, spectra, cyclicity and membership in the Schatten classes. We
give perfect answers for these basic properties, which present lots of
different characterizations with the composition operators on the Hardy space
or the weighted Bergman spaces.


title:
Unusual interlayer quantum transport behavior caused by the zeroth
  Landau level in YbMnBi2

abstract:
  Relativistic fermions in topological quantum materials are characterized by
linear energy-momentum dispersion near band crossing points. Under magnetic
field, relativistic fermions acquire Berry phase of {\pi} in cyclotron motion,
leading to a zeroth Landau level (LL) at the crossing point. Such
field-independent zeroth LL, which distinguishes relativistic fermions from
conventional electron systems, is hardly probed in transport measurements since
the Fermi energy (EF) is usually not right at the band crossing points in most
topological materials. Here we report the observation of exotic quantum
transport behavior resulting from the zeroth LL in a multiband topological
semimetal YbMnBi2 which possesses linear band crossings both at and away from
the Fermi level (FL). We show that the Dirac bands with the crossing points
being above or below the FL leads to Shubnikov de-Haas oscillations in the
in-plane magnetoresistance, whereas the Dirac bands with the crossing points
being at the FL results in unusual angular dependences of the out-of-plane
magnetoresistance and in-plane Hall resistivity due to the dependence of the
zeroth LL's degeneracy on field orientation. Our results shed light on the
transport mechanism of the zeroth LL's relativistic fermions in layered
materials.


title:
Observation of a Charge Density Wave Incommensuration Near the
  Superconducting Dome in CuxTiSe2

abstract:
  X-ray diffraction was employed to study the evolution of the charge density
wave (CDW) in CuxTiSe2 as a function of copper intercalation in order to
clarify the relationship between the CDW and superconductivity. The results
show a CDW incommensuration arising at an intercalation value coincident with
the onset of superconductivity at around x=0.055(5). Additionally, it was found
that the charge density wave persists to higher intercalant concentrations than
previously assumed, demonstrating that the CDW does not terminate inside the
superconducting dome. A charge density wave peak was observed in samples up to
x=0.091(6), the highest copper concentration examined in this study. The phase
diagram established in this work suggests that charge density wave
incommensuration may play a role in the formation of the superconducting state.


title: Non-singular Brans-Dicke collapse in deformed phase space

abstract:
  We study the collapse process of a homogeneous perfect fluid (in FLRW
background) with a barotropic equation of state in Brans-Dicke (BD) theory in
the presence of phase space deformation effects. Such a deformation is
introduced as a particular type of non-commutativity between phase space
coordinates. For the commutative case, it has been shown in the literature [1],
that the dust collapse in BD theory leads to the formation of a spacetime
singularity which is covered by an event horizon. In comparison to general
relativity (GR), the authors concluded that the final state of black holes in
BD theory is identical to the GR case but differs from GR during the dynamical
evolution of the collapse process. However, the presence of non-commutative
effects influences the dynamics of the collapse scenario and consequently a
non-singular evolution is developed in the sense that a bounce emerges at a
minimum radius, after which an expanding phase begins. Such a behavior is
observed for positive values of the BD coupling parameter. For large positive
values of the BD coupling parameter, when non-commutative effects are present,
the dynamics of collapse process differs from the GR case. Finally, we show
that for negative values of the BD coupling parameter, the singularity is
replaced by an oscillatory bounce occurring at a finite time, with the
frequency of oscillation and amplitude being damped at late times.


title: Quantum state transfer for multi-input linear quantum systems

abstract:
  Effective state transfer is one of the most important problems in quantum
information processing. Typically, a quantum information device is composed of
many subsystems with multi-input ports. In this paper, we develop a general
theory describing the condition for perfect state transfer from the multi-input
ports to the internal system components, for general passive linear quantum
systems. The key notion used is the zero of the transfer function matrix.
Application to entanglement generation and distribution in a quantum network is
also discussed.


title:
Emergent facilitation behavior in a distinguishable-particle lattice
  model of glass

abstract:
  We propose an interacting lattice gas model of structural glass characterized
by particle distinguishability and site-particle-dependent random
nearest-neighboring particle interactions. This incorporates disorder quenched
in the configuration space rather than in the physical space. The model
exhibits non-trivial energetics while still admitting exact equilibrium states
directly constructible at arbitrary temperature and density. The dynamics is
defined by activated hopping following standard kinetic Monte Carlo approach
without explicit facilitation rule. Kinetic simulations show emergent dynamic
facilitation behaviors in the glassy phase in which motions of individual voids
are significant only when accelerated by other voids nearby. This provides a
microscopic justification for the dynamic facilitation picture of structural
glass.


title:
On geometry of deformed black holes: II. Schwarzschild hole surrounded
  by a Bach-Weyl ring

abstract:
  We continue to study the response of black-hole space-times on the presence
of additional strong sources of gravity. Restricting ourselves to static and
axially symmetric (electro-)vacuum exact solutions of Einstein's equations, we
first considered the Majumdar--Papapetrou solution for a binary of extreme
black holes in a previous paper, while here we deal with a Schwarzschild black
hole surrounded by a concentric thin ring described by the Bach--Weyl solution.
The geometry is again revealed on the simplest invariants determined by the
metric (lapse function) and its gradient (gravitational acceleration), and by
curvature (Kretschmann scalar). Extending the metric inside the black hole
along null geodesics tangent to the horizon, we mainly focus on the black-hole
interior (specifically, on its sections at constant Killing time) where the
quantities behave in a way indicating a surprisingly strong influence of the
external source. Being already distinct on the level of potential and
acceleration, this is still more pronounced on the level of curvature: for a
sufficiently massive and/or nearby (small) ring, the Kretschmann scalar even
becomes negative in certain toroidal regions mostly touching the horizon from
inside. Such regions have been interpreted as those where magnetic-type
curvature dominates, but here we deal with space-times which do {\em not}
involve rotation and the negative value is achieved due to the {\em
electric}-type components of the Riemann/Weyl tensor. The Kretschmann scalar
also shapes rather non-trivial landscapes {\em outside} the horizon.


title:
Super-resolved 3-D imaging of live cells organelles from bright-field
  photon transmission micrographs

abstract:
  Current biological and medical research is aimed at obtaining a detailed
spatiotemporal map of a live cell's interior to describe and predict cell's
physiological state. We present here an algorithm for complete 3-D modelling of
cellular structures from a z-stack of images obtained using label-free
wide-field bright-field light-transmitted microscopy. The method visualizes 3-D
objects with a volume equivalent to the area of a camera pixel multiplied by
the z-height. The computation is based on finding pixels of unchanged
intensities between two consecutive images of an object spread function. These
pixels represent strongly light-diffracting, light-absorbing, or light-emitting
objects. To accomplish this, variables derived from R\'{e}nyi entropy are used
to suppress camera noise. Using this algorithm, the detection limit of objects
is only limited by the technical specifications of the microscope setup--we
achieve the detection of objects of the size of one camera pixel. This method
allows us to obtain 3-D reconstructions of cells from bright-field microscopy
images that are comparable in quality to those from electron microscopy images.


title: A perspective on Black Hole Horizons from the Quantum Charged Particle

abstract:
  Black hole apparent horizons possess a natural notion of stability, whose
spectral characterization can be related to the problem of the stationary
quantum charged particle. Such mathematical relation leads to an "analyticity
conjecture" on the dependence of the spectral properties on a complex
"fine-structure-constant" parameter, that can reduce the study of the spectrum
of the (non-selfadjoint) MOTS-stability operator to that of the (selfadjoint)
Hamiltonian of the quantum charged particle. Moreover, this perspective might
open an avenue to the spinorial treatment of apparent horizon (MOTS-)stability
and to the introduction of semiclassical tools to explore some of the
qualitative aspects of this black hole spectral problem.


title:
Malliavin Calculus for non Gaussian differentiable measures and surface
  measures in Hilbert spaces

abstract:
  We construct surface measures in a Hilbert space endowed with a probability
measure $\nu$. The theory fits for invariant measures of some stochastic
partial differential equations such as Burgers and reaction--diffusion
equations. Other examples are weighted Gaussian measures and special product
measures $\nu$ of non Gaussian measures; in this case we exhibit a Markov
process having $\nu$ as invariant measure. In any case we prove integration by
parts formulae on sublevel sets of good functions (including spheres and
hyperplanes) that involve surface integrals.


title:
Transient exchange fluctuation theorems for heat using Hamiltonian
  framework: Classical and Quantum

abstract:
  We investigate the statistics of heat exchange between a finite system
coupled to reservoir(s). We have obtained analytical results for heat
fluctuation theorem in the transient regime considering the Hamiltonian
dynamics of the composite system consisting of the system of interest and the
heat bath(s). The system of interest is driven by an external protocol. We
first derive it in the context of a single heat bath. The result is in exact
agreement with known result. We then generalize the treatment to two heat
baths. We further extend the study to quantum systems and show that relations
similar to the classical case hold in the quantum regime. For our study we
invoke von Neumann two point projective measurement in quantum mechanics in the
transient regime. Our result is a generalisation of Jarzynski-W$\grave{o}$jcik
heat fluctuation theorem.


title:
KidsTube: Detection, Characterization and Analysis of Child Unsafe
  Content & Promoters on YouTube

abstract:
  YouTube draws large number of users who contribute actively by uploading
videos or commenting on existing videos. However, being a crowd sourced and
large content pushed onto it, there is limited control over the content. This
makes malicious users push content (videos and comments) which is inappropriate
(unsafe), particularly when such content is placed around cartoon videos which
are typically watched by kids. In this paper, we focus on presence of unsafe
content for children and users who promote it. For detection of child unsafe
content and its promoters, we perform two approaches, one based on supervised
classification which uses an extensive set of video-level, user-level and
comment-level features and another based Convolutional Neural Network using
video frames. Detection accuracy of 85.7% is achieved which can be leveraged to
build a system to provide a safe YouTube experience for kids. Through detailed
characterization studies, we are able to successfully conclude that unsafe
content promoters are less popular and engage less as compared with other
users. Finally, using a network of unsafe content promoters and other users
based on their engagements (likes, subscription and playlist addition) and
other factors, we find that unsafe content is present very close to safe
content and unsafe content promoters form very close knit communities with
other users, thereby further increasing the likelihood of a child getting
getting exposed to unsafe content.


title:
Manipulating antiferromagnets with magnetic fields: ratchet motion of
  multiple domain walls induced by asymmetric field pulses

abstract:
  Future applications of antiferromagnets (AFs) in many spintronics devices
rely on the precise manipulation of domain walls. The conventional approach
using static magnetic fields is inefficient due to the low susceptibility of
AFs. Recently proposed electrical manipulation with spin-orbit torques is
restricted to metals with a specific crystal structure.
  Here we propose an alternative, broadly applicable approach: using asymmetric
magnetic field pulses to induce controlled ratchet motion of AF domain walls.
  The efficiency of this approach is based on three peculiarities of AF
dynamics. First, a time-dependent magnetic field couples with an AF order
parameter stronger than a static magnetic field, which leads to higher mobility
of the domain walls. Second, the rate of change of the magnetic field couples
with the spatial variation of the AF order parameter inside the domain and this
enables synchronous motion of multiple domain walls with the same structure.
Third, tailored asymmetric field pulses in combination with static friction can
prevent backward motion of domain walls and thus lead to the desired controlled
ratchet effect.
  The proposed use of an external field, rather than internal spin-orbit
torques, avoids any restrictions on size, conductivity, and crystal structure
of the AF material.
  We believe that our approach paves a way for the development of new AF-based
devices based on controlled motion of AF domain walls.


title: Coulomb-blockade effect in nonlinear mesoscopic capacitors

abstract:
  We consider an interacting quantum dot working as a coherent source of single
electrons. The dot is tunnel coupled to a reservoir and capacitively coupled to
a gate terminal with an applied ac potential. At low frequencies, this is the
quantum analog of the RC circuit with a purely dynamical response. We
investigate the quantized dynamics as a consequence of ac pulses with large
amplitude. Within a Keldysh-Green function formalism we derive the
time-dependent current in the Coulomb blockade regime. Our theory thus extends
previous models that considered either noninteracting electrons in nonlinear
response or interacting electrons in the linear regime. We prove that the
electron emission and absorption resonances undergo a splitting when the
charging energy is larger than the tunnel broadening. For very large charging
energies, the additional peaks collapse and the original resonances are
recovered, though with a reduced amplitude. Quantization of the charge emitted
by the capacitor is reduced due to Coulomb repulsion and additional plateaus
arise. Additionally, we discuss the differential capacitance and resistance as
a function of time. We find that to leading order in driving frequency the
current can be expressed as a weighted sum of noninteracting currents shifted
by the charging energy.


title:
Quantitative results on the Ishikawa iteration of Lipschitz
  pseudo-contractions

abstract:
  We compute uniform rates of metastability for the Ishikawa iteration of a
Lipschitz pseudo-contractive self-mapping of a compact convex subset of a
Hilbert space. This extraction is an instance of the proof mining program that
aims to apply tools from mathematical logic in order to extract the hidden
quantitative content of mathematical proofs. We prove our main result by
applying methods developed by Kohlenbach, the first author and Nicolae for
obtaining quantitative versions of strong convergence results for generalized
Fej\'er monotone sequences in compact subsets of metric spaces.


title:
Overview on the phenomenon of two-qubit entanglement revivals in
  classical environments

abstract:
  The occurrence of revivals of quantum entanglement between separated open
quantum systems has been shown not only for dissipative non-Markovian quantum
environments but also for classical environments in absence of back-action.
While the phenomenon is well understood in the first case, the possibility to
retrieve entanglement when the composite quantum system is subject to local
classical noise has generated a debate regarding its interpretation. This
dynamical property of open quantum systems assumes an important role in quantum
information theory from both fundamental and practical perspectives. Hybrid
quantum-classical systems are in fact promising candidates to investigate the
interplay among quantum and classical features and to look for possible control
strategies of a quantum system by means of a classical device. Here we present
an overview on this topic, reporting the most recent theoretical and
experimental results about the revivals of entanglement between two qubits
locally interacting with classical environments. We also review and discuss the
interpretations provided so far to explain this phenomenon, suggesting that
they can be cast under a unified viewpoint.


title: STFCN: Spatio-Temporal FCN for Semantic Video Segmentation

abstract:
  This paper presents a novel method to involve both spatial and temporal
features for semantic video segmentation. Current work on convolutional neural
networks(CNNs) has shown that CNNs provide advanced spatial features supporting
a very good performance of solutions for both image and video analysis,
especially for the semantic segmentation task. We investigate how involving
temporal features also has a good effect on segmenting video data. We propose a
module based on a long short-term memory (LSTM) architecture of a recurrent
neural network for interpreting the temporal characteristics of video frames
over time. Our system takes as input frames of a video and produces a
correspondingly-sized output; for segmenting the video our method combines the
use of three components: First, the regional spatial features of frames are
extracted using a CNN; then, using LSTM the temporal features are added;
finally, by deconvolving the spatio-temporal features we produce pixel-wise
predictions. Our key insight is to build spatio-temporal convolutional networks
(spatio-temporal CNNs) that have an end-to-end architecture for semantic video
segmentation. We adapted fully some known convolutional network architectures
(such as FCN-AlexNet and FCN-VGG16), and dilated convolution into our
spatio-temporal CNNs. Our spatio-temporal CNNs achieve state-of-the-art
semantic segmentation, as demonstrated for the Camvid and NYUDv2 datasets.


title: Low Algorithmic Complexity Entropy-deceiving Graphs

abstract:
  In estimating the complexity of objects, in particular of graphs, it is
common practice to rely on graph- and information-theoretic measures. Here,
using integer sequences with properties such as Borel normality, we explain how
these measures are not independent of the way in which an object, such as a
graph, can be described or observed. From observations that can reconstruct the
same graph and are therefore essentially translations of the same description,
we will see that when applying a computable measure such as Shannon Entropy,
not only is it necessary to pre-select a feature of interest where there is
one, and to make an arbitrary selection where there is not, but also that more
general properties, such as the causal likelihood of a graph as a measure
(opposed to randomness), can be largely misrepresented by computable measures
such as Entropy and Entropy rate. We introduce recursive and non-recursive
(uncomputable) graphs and graph constructions based on these integer sequences,
whose different lossless descriptions have disparate Entropy values, thereby
enabling the study and exploration of a measure's range of applications and
demonstrating the weaknesses of computable measures of complexity.


title: Irreversible Samplers from Jump and Continuous Markov Processes

abstract:
  In this paper, we propose irreversible versions of the Metropolis Hastings
(MH) and Metropolis adjusted Langevin algorithm (MALA) with a main focus on the
latter. For the former, we show how one can simply switch between different
proposal and acceptance distributions upon rejection to obtain an irreversible
jump sampler (I-Jump). The resulting algorithm has a simple implementation akin
to MH, but with the demonstrated benefits of irreversibility. We then show how
the previously proposed MALA method can also be extended to exploit
irreversible stochastic dynamics as proposal distributions in the I-Jump
sampler. Our experiments explore how irreversibility can increase the
efficiency of the samplers in different situations.


title: Stationary Charged Scalar Clouds around Black Holes in String Theory

abstract:
  It was reported that Kerr-Newman black holes can support linear charged
scalar fields in their exterior regions. These stationary massive charged
scalar fields can form bound states, which are called stationary scalar clouds.
In this paper, we show that Kerr-Sen black holes can also support stationary
massive charged scalar clouds by matching the near- and far-region solutions of
the radial part of the Klein-Gordon wave equation. We also review stationary
scalar clouds within the background of static electrically charged black hole
solutions in the low-energy limit of heterotic string field theory, namely, the
Gibbons-Maeda-Garfinkle-Horowitz-Strominger black holes.


title:
Third harmonic generation from graphene lying on different substrates:
  Optical-phonon resonances and interference effects

abstract:
  Graphene is a nonlinear material which can be used as a saturable absorber,
frequency mixer and frequency multiplier. We investigate the third harmonic
generation from graphene lying on different substrates, consisting of a
dielectric (dispersionless or polar), metalized or non-metalized on the back
side. We show that the third harmonic intensity emitted from graphene lying on
a substrate, can be increased by orders of magnitude as compared to the
isolated graphene, due the LO-phonon resonances in a polar dielectric or due to
the interference effects in the substrates metalized on the back side. In some
frequency intervals, the presence of the polar dielectric substrate compensates
the strongly decreasing with $\omega$ frequency dependence of the third-order
conductivity of graphene making the response almost frequency independent.


title:
Topological transitions and fractional charges induced by strain and
  magnetic field in carbon nanotubes

abstract:
  We show that carbon nanotubes (CNT) can be driven through a topological phase
transition using either strain or a magnetic field. This can naturally lead to
Jackiw-Rebbi soliton states carrying fractionalized charges, similar to those
found in a domain wall in the Su-Schrieffer-Heeger model, in a setup with a
spatially inhomogeneous strain and an axial field. Two types of fractionalized
states can be formed at the interface between regions with different strain: a
spin-charge separated state with integer charge and spin zero (or zero charge
and spin $\pm \hbar/2$), and a state with charge $\pm e/2$ and spin $\pm
\hbar/4$. The latter state requires spin-orbit coupling in the CNT. We show
that in our setup, the precise quantization of the fractionalized interface
charges is a consequence of the symmetry of the CNT under a combination of a
spatial rotation by $\pi$ and time reversal. Finally, we comment on the effects
of many-body interaction on this phenomena.


title: Lattice spin models for non-Abelian Chiral Spin Liquids

abstract:
  We suggest a class of two-dimensional lattice spin Hamiltonians describing
non-Abelian SU(2) chiral spin liquids - spin-analogues of fractional
non-Abelian quantum Hall states- with gapped bulk and gapless chiral edge
excitations described by the SU(2)$_n$ Wess-Zumino-Novikov-Witten conformal
field theory. The models are constructed from an array of a generalized
spin-$n/2$ ladders with multi-spin exchange interaction which are coupled by
isolated spins. Such models allow a controllable analytic treatment starting
from the one-dimensional limit and are characterized by a bulk gap and
non-Abelian SU(2)$_n$ gapless edge excitations.


title: Chiral EFT based nuclear forces: Achievements and challenges

abstract:
  During the past two decades, chiral effective field theory has become a
popular tool to derive nuclear forces from first principles. Two-nucleon
interactions have been worked out up to sixth order of chiral perturbation
theory and three-nucleon forces up to fifth order. Applications of some of
these forces have been conducted in nuclear few- and many-body systems---with a
certain degree of success. But in spite of these achievements, we are still
faced with great challenges. Among them is the issue of a proper uncertainty
quantification of predictions obtained when applying these forces in {\it ab
initio} calculations of nuclear structure and reactions. A related problem is
the order by order convergence of the chiral expansion. We start this review
with a pedagogical introduction and then present the current status of the
field of chiral nuclear forces. This is followed by a discussion of
representative examples for the application of chiral two- and three-body
forces in the nuclear many-body system including convergence issues.


title:
On the formation of a quasi-stationary twisted disc after a tidal
  disruption event

abstract:
  We investigate misaligned accretion discs formed after tidal disruption
events that occur when a star encounters a supermassive black hole. We employ
the linear theory of warped accretion discs to find the shape of a disc for
which the stream arising from the disrupted star provides a source of angular
momentum that is misaligned with that of the black hole. For quasi-steady
configurations we find that when the warp diffusion or propagation time is
large compared to the local mass accretion time and/or the natural disc
alignment radius is small, misalignment is favoured. These results have been
verified using SPH simulations. We also simulated 1D model discs including gas
and radiation pressure. As accretion rates initially exceed the Eddington limit
the disc is initially advection dominated. Assuming the $\alpha$ model for the
disc, where it can be thermally unstable it subsequently undergoes cyclic
transitions between high and low states. During these transitions the aspect
ratio varies from $\sim 1$ to $\sim 10^{-3}$ which is reflected in changes in
the degree of disc misalignment at the stream impact location. For maximal
black hole rotation and sufficiently large values of viscosity parameter
$\alpha > \sim 0.01-0.1$ the ratio of the disc inclination to that of the
initial stellar orbit is estimated to be $0.1-0.2$ in the advection dominated
state, while reaching of order unity in the low state. Misalignment descreases
with decrease of $\alpha$, but increases as the black hole rotation parameter
decreases. Thus, it is always significant when the latter is small.


title: Asymmetric Backscattering from the Hybrid Magneto-Electric Meta Particle

abstract:
  The optical theorem relates the total scattering cross-section of a given
structure with its forward scattering, but does not impose any restrictions on
other directions. Strong backward-forward asymmetry in scattering could be
achieved by exploring retarded coupling between particles, exhibiting both
electric and magnetic resonances. Here, a hybrid magneto-electric particle
(HMEP), consisting of a split ring resonator acting as a magnetic dipole and a
wire antenna acting as an electric dipole, is shown to possess asymmetric
scattering properties. When illuminated from opposite directions with the same
polarization of the electric field, the structure has exactly the same forward
scattering, while the backward scattering is drastically different. The
scattering cross section is shown to be as low as zero at a narrow frequency
range when illuminated from one side, while being maximal at the same frequency
range when illuminated from the other side. Theoretical predictions of the
phenomena are supported with both numerical and experimental conformations,
obtained at the GHz frequency range, and all are in a good agreement with each
other. HMEP meta-particles could be used as building blocks for various
metamaterials assembling solar cells, invisibility cloaks, holographic masks
and more.


title:
Towards Dependable Change Management and Traceability for Global
  Software Development

abstract:
  This paper reports on our definition of guidelines for managing global
software development (GSD) that implements the specific practice - manage
requirements changes - of the Capability Maturity Model Integration (CMMI)
Level 2. The guidelines present a model for change management and traceability
that supports the implementation of the specific CMMI Level 2 goal. Also, to
support the effective management of the system engineering processes, an
adaptation of the Project Management Body of Knowledge (PMBOK) process group
(PG) for project life-cycle practices is provided. We introduce a cloud-based
Reactive Middleware which provides services for managing GSD projects towards
dependable change management and traceability.


title:
Social Networks Analysis in Discovering the Narrative Structure of
  Literary Fiction

abstract:
  In our paper we would like to make a cross-disciplinary leap and use the
tools of network theory to understand and explore narrative structure in
literary fiction, an approach that is still underestimated. However, the
systems in fiction are sensitive to readers subjectivity and attention must to
be paid to different methods of extracting networks. The project aims at
investigating into different ways social interactions are read in texts by
comparing networks produced by automated algorithms-natural language processing
with those created by surveying more subjective human responses. Conversation
networks from fiction have been already extracted by scientists, but the more
general framework surrounding these interactions was missing. We propose
several NLP methods for detecting interactions and test them against a range of
human perceptions. In doing so, we have pointed to some limitations of using
network analysis to test literary theory, e.g. interaction, which corresponds
to the plot, does not form climax.


title: Inverting Variational Autoencoders for Improved Generative Accuracy

abstract:
  Recent advances in semi-supervised learning with deep generative models have
shown promise in generalizing from small labeled datasets
($\mathbf{x},\mathbf{y}$) to large unlabeled ones ($\mathbf{x}$). In the case
where the codomain has known structure, a large unfeatured dataset
($\mathbf{y}$) is potentially available. We develop a parameter-efficient, deep
semi-supervised generative model for the purpose of exploiting this untapped
data source. Empirical results show improved performance in disentangling
latent variable semantics as well as improved discriminative prediction on
Martian spectroscopic and handwritten digit domains.


title: Which activation function of cooperation describes human behavior?

abstract:
  Properties of cooperation's probability function in Prisoner`s Dilemma have
impact on evolution of game. Basic model defines that probability of
cooperation depends linearly, both on the player's altruism and the co-player's
reputation. I propose modification of activation function to smooth one
(hyperbolic tangent with scaling parameter a, which corresponds to its shape)
and observe three phases for different range of a. (1) For small a, strategies
seem to randomly change in time and situation of mixed choices (one cooperates
and second defects) dominate. (2) For medium a, players choose only one
strategy for given period of time (the common state can switch to opposite one
with some probability). (3) For large a, mixed strategy (once defect, once
cooperate) is coexisting with common strategies and no change is allowed. I
believe that proposed function characterizes better socio-economical phenomena
and especially phase 1 and 2 contain most of human behavior.


title: The Beta Generalized Marshall-Olkin-G Family of Distributions

abstract:
  In this paper we propose a new family of distribution considering Generalized
Marshal-Olkin distribution as the base line distribution in the Beta-G family
of Construction. The new family includes Beta-G (Eugene et al. 2002 and Jones,
2004) and (Jayakumar and Mathew, 2008) families as particular cases.
Probability density function (pdf) and the cumulative distribution function
(cdf) are expressed as mixture of the Marshal-Olkin (Marshal and Olkin, 1997)
distribution. Series expansions of pdf of the order statistics are also
obtained. Moments, moment generating function, R\'enyi entropies, quantile
power series, random sample generation and asymptotes are also investigated.
Parameter estimation by method of maximum likelihood and method of moment are
also presented. Finally proposed model is compared to the Generalized
Marshall-Olkin Kumaraswamy extended family (Handique and Chakraborty, 2015) by
considering three data fitting examples with real life data sets.


title: More on the Arens regularity of B(X)

abstract:
  We focus on a question raised by Daws [Arens regularity of the algebra of
operators on a Banach space, Bull. Lond. Math. Soc. 36 (2004), 493-503]
concerning the Arens regularity of B(X), the algebra of operators on a Banach
space X. Among other things, we show that B(X) is Arens regular if and only if
X is ultrareflexive .


title: The Kumaraswamy Generalized Marshall-Olkin-G family of distributions

abstract:
  Another new family of continuous probability distribution is proposed by
using Generalized Marshal-Olkin distribution as the base line distribution in
the Kumaraswamy-G distribution. This family includes (Cordeiro and de Castro,
2011) and (Jayakumar and Mathew, 2008) families special case besides a under of
other distributions. The probability density function (pdf) and the survival
function (sf) are expressed as series to observe as a mixture of the
Generalized Marshal-Olkin distribution. Series expansions pdf of order
statistics are also obtained. Moments, moment generating function, R\'enyi
entropies, quantile function, random sample generation and asymptotes are also
investigated. Parameter estimation by method of maximum likelihood and method
of moment are also presented. Finally the proposed model is compared to the
Generalized Marshall-Olkin Kumaraswamy extended family (Handique and
Chakraborty, 2015) by considering four examples of real life data modeling.


title:
Spinodal Decomposition-Enabled Halide Perovskite Double Heterostructure
  with Reduced Fr\"ohlich Electron-Phonon Coupling

abstract:
  Epitaxial III-V semiconductor heterostructures are key components in modern
microelectronics, electro-optics and optoelectronics. With superior
semiconducting properties, halide perovskite materials are rising as promising
candidates for coherent heterostructure devices. In this report, spinodal
decomposition is proposed and experimentally implemented to produce epitaxial
double heterostructures in halide perovskite system. Pristine epitaxial mixed
halide perovskites rods and films were synthesized via Van der Waals epitaxy by
chemical vapor deposition method. At room temperature, photon was applied as a
knob to regulate the kinetics of spinodal decomposition and classic coarsening.
By this approach, halide perovskite double heterostructures were created
carrying epitaxial interfaces and outstanding optical properties. Reduced
Fr\"ohlich electron-phonon coupling was discovered in coherent halide double
heterostructure, which is hypothetically attributed to the classic phonon
confinement effect widely existing in III-V double heterostructures. The
ability to develop coherent double heterostructures in halide perovskites paves
an avenue to exploring halide perovskite-based quantum wells and superlattices
for high-performance and low-cost optoelectronics, electro-optics and
microelectronics.


title:
Hidden orbital polarization in diamond, silicon, germanium, gallium
  arsenide and layered materials

abstract:
  It was previously believed that the Bloch electronic states of non-magnetic
materials with inversion symmetry cannot have finite spin polarizations.
However, since the seminal work by Zhang et al. [Nat. Phys. 10, 387-393 (2014)]
on local spin polarizations of Bloch states in non-magnetic, centrosymmetric
materials, the scope of spintronics has been significantly broadened. Here, we
show, using a framework that is universally applicable independent of whether
hidden spin polarizations are small (e.g., diamond, Si, Ge, and GaAs) or large
(e.g., MoS2 and WSe2), that the corresponding quantity arising from orbital -
instead of spin - degrees of freedom, the hidden orbital polarization, is (i)
much more abundant in nature since it exists even without spin-orbit coupling
and (ii) more fundamental since the interband matrix elements of the
site-dependent orbital angular momentum operator determines the hidden spin
polarization. We predict that the hidden spin polarization of transition metal
dichalcogenides is reduced significantly upon compression. We suggest
experimental signatures of hidden orbital polarization from photoemission
spectroscopies and demonstrate that the current-induced hidden orbital
polarization may play a far more important role than its spin counterpart in
antiferromagnetic information technology by calculating the current-driven
antiferromagnetism in compressed silicon.


title: Hermitian geometry on resolvent set(I)

abstract:
  For a tuple $A=(A_1,\ A_2,\ ...,\ A_n)$ of elements in a unital Banach
algebra ${\mathcal B}$, its projective joint spectrum $P(A)$ is the collection
of $z\in {\mathbb C}^n$ such that $A(z)=z_1A_1+z_2A_2+\cdots +z_nA_n$ is not
invertible. It is known that the ${\mathcal B}$-valued $1$-form
$\omega_A(z)=A^{-1}(z)dA(z)$ contains much topological information about the
joint resolvent set $P^c(A)$. This paper studies geometric properties of
$P^c(A)$ with respect to Hermitian metrics defined through the ${\mathcal
B}$-valued {\em fundamental form} $\Omega_A=-\omega^*_A\wedge \omega_A$ and its
coupling with faithful states $\phi$ on ${\mathcal B}$, i.e. $\phi(\Omega_A)$.
The connection between the tuple $A$ and the metric is the main subject of this
paper. In particular, it shows that the K\"{a}hlerness of the metric is tied
with the commutativity of the tuple, and its completeness is related to the
Fuglede-Kadison determinant.