title: Repairing Conflicts among MVCC Transactions

abstract:
  The optimistic variants of MVCC (Multi-Version Concurrency Control) avoid
blocking concurrent transactions at the cost of having a validation phase. Upon
failure in the validation phase, the transaction is usually aborted and
restarted from scratch. The "abort and restart" approach becomes a performance
bottleneck for the use cases with high contention objects or long running
transactions. In addition, restarting from scratch creates a negative feedback
loop in the system, because the system incurs additional overhead that may
create even further conflicts.
  In this paper, we propose a novel approach for conflict resolution in MVCC
for in-memory databases. This low overhead approach summarizes the transaction
programs in the form of a dependency graph. The dependency graph also contains
the constructs used in the validation phase of the MVCC algorithm. Then, in the
case of encountering conflicts among transactions, the conflict locations in
the program are quickly detected, and the conflicting transactions are
partially re-executed. This approach maximizes the reuse of the computations
done in the initial execution round, and increases the transaction processing
throughput.


title: Bond chaos in spin glasses revealed through thermal boundary conditions

abstract:
  Spin glasses have competing interactions that lead to a rough energy
landscape which is highly susceptible to small perturbations. These chaotic
effects strongly affect numerical simulations and, as such, gaining a deeper
understanding of chaos in spin glasses is of much importance. The use of
thermal boundary conditions is an effective approach to study chaotic
phenomena. Here, we generalize population annealing Monte Carlo, combined with
thermal boundary conditions, to study bond chaos due to small perturbations in
the spin-spin couplings of the three-dimensional Edwards-Anderson Ising spin
glass. We show that bond and temperature-induced chaos share the same scaling
exponents and that bond chaos is stronger than temperature chaos.


title: On the capacity of information processing systems

abstract:
  We propose and analyze a family of information processing systems, where a
finite set of experts or servers are employed to extract information about a
stream of incoming jobs. Each job is associated with a hidden label drawn from
some prior distribution. An inspection by an expert produces a noisy outcome
that depends both on the job's hidden label and the type of the expert, and
occupies the expert for a finite time duration. A decision maker's task is to
dynamically assign inspections so that the resulting outcomes can be used to
accurately recover the labels of all jobs, while keeping the system stable.
Among our chief motivations are applications in crowd-sourcing, diagnostics,
and experiment designs, where one wishes to efficiently learn the nature of a
large number of items, using a finite pool of computational resources or human
agents.
  We focus on the capacity of such an information processing system. Given a
level of accuracy guarantee, we ask how many experts are needed in order to
stabilize the system, and through what inspection architecture. Our main result
provides an adaptive inspection policy that is asymptotically optimal in the
following sense: the ratio between the required number of experts under our
policy and the theoretical optimal converges to one, as the probability of
error in label recovery tends to zero.


title:
The NANOGrav Nine-year Data Set: Mass and Geometric Measurements of
  Binary Millisecond Pulsars

abstract:
  We analyze 24 binary radio pulsars in the North American Nanohertz
Observatory for Gravitational Waves (NANOGrav) nine-year data set. We make
fourteen significant measurements of Shapiro delay, including new detections in
four pulsar-binary systems (PSRs J0613$-$0200, J2017+0603, J2302+4442, and
J2317+1439), and derive estimates of the binary-component masses and orbital
inclination for these MSP-binary systems. We find a wide range of binary pulsar
masses, with values as low as $m_{\rm p} =
1.18^{+0.10}_{-0.09}\text{M}_{\odot}$ for PSR J1918$-$0642 and as high as
$m_{\rm p} = 1.928^{+0.017}_{-0.017}\text{M}_{\odot}$ for PSR J1614$-$2230
(both 68.3\% credibility). We make an improved measurement of the Shapiro
timing delay in the PSR J1918$-$0642 and J2043+1711 systems, measuring the
pulsar mass in the latter system to be $m_{\rm p} =
1.41^{+0.21}_{-0.18}\text{M}_{\odot}$ (68.3\% credibility) for the first time.
We measure secular variations of one or more orbital elements in many systems,
and use these measurements to further constrain our estimates of the pulsar and
companion masses whenever possible. In particular, we used the observed Shapiro
delay and periastron advance due to relativistic gravity in the PSR J1903+0327
system to derive a pulsar mass of $m_{\rm p} =
1.65^{+0.02}_{-0.02}\text{M}_{\odot}$ (68.3\% credibility). We discuss the
implications that our mass measurements have on the overall neutron-star mass
distribution, and on the "mass/orbital-period" correlation due to extended mass
transfer.


title:
US-Cut: Interactive Algorithm for rapid Detection and Segmentation of
  Liver Tumors in Ultrasound Acquisitions

abstract:
  Ultrasound (US) is the most commonly used liver imaging modality worldwide.
It plays an important role in follow-up of cancer patients with liver
metastases. We present an interactive segmentation approach for liver tumors in
US acquisitions. Due to the low image quality and the low contrast between the
tumors and the surrounding tissue in US images, the segmentation is very
challenging. Thus, the clinical practice still relies on manual measurement and
outlining of the tumors in the US images. We target this problem by applying an
interactive segmentation algorithm to the US data, allowing the user to get
real-time feedback of the segmentation results. The algorithm has been
developed and tested hand-in-hand by physicians and computer scientists to make
sure a future practical usage in a clinical setting is feasible. To cover
typical acquisitions from the clinical routine, the approach has been evaluated
with dozens of datasets where the tumors are hyperechoic (brighter), hypoechoic
(darker) or isoechoic (similar) in comparison to the surrounding liver tissue.
Due to the interactive real-time behavior of the approach, it was possible even
in difficult cases to find satisfying segmentations of the tumors within
seconds and without parameter settings, and the average tumor deviation was
only 1.4mm compared with manual measurements. However, the long term goal is to
ease the volumetric acquisition of liver tumors in order to evaluate for
treatment response. Additional aim is the registration of intraoperative US
images via the interactive segmentations to the patient's pre-interventional CT
acquisitions.


title: Computing Linear Systems on Metric Graphs

abstract:
  The linear system $|D|$ of a divisor $D$ on a metric graph has the structure
of a cell complex. We introduce the anchor divisors and anchor cells in it -
they serve as the landmarks for us to compute the f-vector of the complex and
find all cells in the complex. A linear system can also be identified as a
tropical convex hull of rational functions. We compute its extremal generators
using the landmarks. We apply these methods to some examples - namely the
canonical linear systems of some small trivalent graphs.


abstract:
  We study the Euler obstruction of essentially isolated determinantal
singularities (EIDS). The EIDS were defined by W. Ebeling and S. Gusein-Zade,
as a generalization of isolated singularity. We obtain some formulas to
calculate the Euler obstruction for the determinantal varieties with singular
set an ICIS.


title:
Common Origin of Kinetic Scale Turbulence and the Electron Halo in the
  Solar Wind -- Connection to Nanoflares

abstract:
  We summarize our recent studies on the origin of solar wind kinetic scale
turbulence and electron halo in the electron velocity distribution function.
Increasing observations of nanoflares and microscopic type III radio bursts
strongly suggest that nanoflares and accelerated electron beams are common in
the corona. Based on particle-in-cell simulations, we show that both the
core-halo feature and kinetic scale turbulence observed in the solar wind can
be produced by the nonlinear evolution of electron two-stream instability
driven by nanoflare accelerated electron beams. The energy exchange between
waves and particles reaches equilibrium in the inner corona and the key
features of the turbulence and velocity distribution are preserved as the solar
wind escapes into interplanetary space along open magnetic field lines.
Observational tests of the model and future theoretical work are discussed.


title: Synthesized Classifiers for Zero-Shot Learning

abstract:
  Given semantic descriptions of object classes, zero-shot learning aims to
accurately recognize objects of the unseen classes, from which no examples are
available at the training stage, by associating them to the seen classes, from
which labeled examples are provided. We propose to tackle this problem from the
perspective of manifold learning. Our main idea is to align the semantic space
that is derived from external information to the model space that concerns
itself with recognizing visual features. To this end, we introduce a set of
"phantom" object classes whose coordinates live in both the semantic space and
the model space. Serving as bases in a dictionary, they can be optimized from
labeled data such that the synthesized real object classifiers achieve optimal
discriminative performance. We demonstrate superior accuracy of our approach
over the state of the art on four benchmark datasets for zero-shot learning,
including the full ImageNet Fall 2011 dataset with more than 20,000 unseen
classes.


title:
Correlation effects on electron-phonon coupling in semiconductors:
  many-body theory along thermal lines

abstract:
  A method is proposed for the inclusion of electron correlation in the
calculation of the temperature dependence of band structures arising from
electron-phonon coupling. It relies on an efficient exploration of the
vibrational phase space along the recently introduced thermal lines. Using the
$G_0W_0$ approximation, the temperature dependence of the direct gaps of
diamond, silicon, lithium fluoride, magnesium oxide, and titanium dioxide is
calculated. Within the proposed formalism, a single calculation at each
temperature of interest is sufficient to obtain results of the same accuracy as
in alternative, more expensive methods. It is shown that many-body
contributions beyond semi-local density functional theory modify the
electron-phonon coupling strength by almost $50$% in diamond, silicon, and
titanium dioxide, but by less than $5$% in lithium flouride and magnesium
oxide. The results reveal a complex picture regarding the validity of
semi-local functionals for the description of electron-phonon coupling.


title:
Demonstrating the likely neutron star nature of five M31 globular
  cluster sources with Swift-NuSTAR spectroscopy

abstract:
  We present the results of a joint Swift-NuSTAR spectroscopy campaign on M31.
We focus on the five brightest globular cluster X-ray sources in our fields.
Two of these had previously been argued to be black hole candidates on the
basis of apparent hard-state spectra at luminosities above those for which
neutron stars are in hard states. We show that these two sources are likely to
be Z-sources (i.e. low magnetic field neutron stars accreting near their
Eddington limits), or perhaps bright atoll sources (low magnetic field neutron
stars which are just a bit fainter than this level) on the basis of
simultaneous Swift and NuSTAR spectra which cover a broader range of energies.
These new observations reveal spectral curvature above 6-8 keV that would be
hard to detect without the broader energy coverage the NuSTAR data provide
relative to Chandra and XMM-Newton. We show that the other three sources are
also likely to be bright neutron star X-ray binaries, rather than black hole
X-ray binaries. We discuss why it should already have been realized that it was
unlikely that these objects were black holes on the basis of their being
persistent sources, and we re-examine past work which suggested that tidal
capture products would be persistently bright X-ray emitters. We discuss how
this problem is likely due to neglecting disk winds in older work that predict
which systems will be persistent and which will be transient.


abstract:
  We investigate how the dimensionless ratio given by the Chern-Simons
diffusion rate $\Gamma_{\textrm{CS}}$ divided by the product of the entropy
density $s$ and temperature $T$ behaves across different kinds of phase
transitions in the class of bottom-up non-conformal Einstein-dilaton
holographic models originally proposed by Gubser and Nellore. By tuning the
dilaton potential, one is able to holographically mimic a first order, a second
order, or a crossover transition. In a first order phase transition,
$\Gamma_{\textrm{CS}}/sT$ jumps at the critical temperature (as previously
found in the holographic literature), while in a second order phase transition
it develops an infinite slope. On the other hand, in a crossover,
$\Gamma_{\textrm{CS}}/sT$ behaves smoothly, although displaying a fast
variation around the pseudo-critical temperature. In all the cases,
$\Gamma_{\textrm{CS}}/sT$ increases with decreasing $T$. The behavior of the
Chern-Simons diffusion rate across different phase transitions is expected to
play a relevant role for the chiral magnetic effect around the QCD critical end
point, which is a second order phase transition point connecting a crossover
band to a line of first order phase transition. Our findings in the present
work add to the literature the first predictions for the Chern-Simons diffusion
rate across second order and crossover transitions in strongly coupled
non-conformal, non-Abelian gauge theories.


title:
Selecting the pre-detection characteristics for effective fiber coupling
  of entangled photon sources

abstract:
  Photon modes have an important role in characterizing the quantum sources of
light. Proper coupling of various photon modes obtained in spontaneous
parametric down conversion (SPDC) process in optical fibers is essential to
generate an effective source of entangled photons. The two main pre-detection
factors affecting the biphoton mode coupling in SPDC are the pump beam focusing
parameter and the crystal thickness. We present the numerical and experimental
results on the effect of pump focusing on conditional down-converted photon
modes for a Type-I BBO crystal. We experimentally verify that biphoton coupling
efficiency decreases asymptotically with pump beam focusing parameter. We
attribute this behaviour to (a) the asymmetry in the spatial distribution of
down-converted photons with the pump beam focusing parameter and (b) the
ellipticity of biphoton modes introduced due to the focusing of the pump beam.
We also show experimentally the ellipticity as well as quantify the asymmetry
with the pump focusing parameter. These results may be useful in selecting
optimum conditions in the down-conversion process for generating efficient
sources of entangled photons for quantum information applications.


title:
Superplot: a graphical interface for plotting and analysing MultiNest
  output

abstract:
  We present an application, Superplot, for calculating and plotting
statistical quantities relevant to parameter inference from a "chain" of
samples drawn from a parameter space, produced by e.g. MultiNest. A simple
graphical interface allows one to browse a chain of many variables quickly, and
make publication quality plots of, inter alia, one- and two-dimensional profile
likelihood, posterior pdf (with kernel density estimation), confidence
intervals and credible regions. In this short manual, we document installation
and basic usage, and define all statistical quantities and conventions. The
code is fully compatible with Linux, Windows and Mac OSX. Furthermore, if
preferred, all functionality is available through the command line rather than
a graphical interface.


title:
Instability for the rotation set of diffeomorphisms of the torus
  homotopic to the identity

abstract:
  The aim of this short note is to explain how the arguments of the "closing
lemma with time control" of F. Abdenur and S. Crovisier (arXiv:1111.4206) can
be used to answer Question 1 of the article "Instability for the rotation set
of homeomorphisms of the torus homotopic to the identity" of S. Addas-Zanata.


title:
First-order patterning transitions on a sphere as a route to cell
  morphology

abstract:
  We propose a general theory for surface patterning in many different
biological systems, including mite and insect cuticles, pollen grains, fungal
spores, and insect eggs. The patterns of interest are often intricate and
diverse, yet an individual pattern is robustly reproducible by a single species
and a similar set of developmental stages produces a variety of patterns. We
argue that the pattern diversity and reproducibility may be explained by
interpreting the pattern development as a first-order phase transition to a
spatially modulated phase. Brazovskii showed that for such transitions on a
flat, infinite sheet, the patterns are uniform striped or hexagonal. Biological
objects, however, have finite extent and offer different topologies, such as
the spherical surfaces of pollen grains. We consider Brazovskii transitions on
spheres and show that the patterns have a richer phenomenology than simple
stripes or hexagons. We calculate the free energy difference between the
unpatterned state and the many possible patterned phases, taking into account
fluctuations and the system's finite size. The proliferation of variety on a
sphere may be understood as a consequence of topology, which forces defects
into perfectly ordered phases. The defects are then accommodated in different
ways. We also argue that the first-order character of the transition is
responsible for the reproducibility and robustness of the pattern formation.


title:
Site-selective NMR for odd-frequency Cooper pairs around vortex in
  chiral p-wave superconductors

abstract:
  In order to identify the pairing symmetry with chirality, we study
site-selective NMR in chiral p-wave superconductors. We calculate local nuclear
relaxation rate 1/T_1 in the vortex lattice state by Eilenberger theory,
including the applied magnetic field dependence. We find that 1/T_1 in the NMR
resonance line shape is different between two chiral states
p_{pm}(=p_x{pm}ip_y), depending on whether the chirality is parallel or
anti-parallel to the vorticity. Anomalous suppression of 1/T_1 occurs around
the vortex core in the chiral p_- wave due to the negative coherence term
coming from the odd-frequency s-wave Cooper pair induced around the vortex with
Majorana state.


title:
Strong decay mode $J/\psi p$ of hidden charm pentaquark states
  $P_c^+(4380)$ and $P_c^+(4450)$ in $\Sigma_c \bar{D}^*$ molecular scenario

abstract:
  We study the strong decay channels $P_c^+(4380) \to J/\psi p$ and
$P_c^+(4450) \to J/\psi p$ under $\Sigma_c \bar{D}^*$ molecular state ansatz.
With various spin-parity assignments, the partial decay widths of $J/\psi p$
final state are calculated. Our results show that all the $P$ wave $\Sigma_c
{\bar D}^*$ assignments are excluded, while $S$ wave $\Sigma_c {\bar D}^*$
pictures for $P_c(4380)$ and $P_c(4450)$ are both allowed by present
experimental data. The $J^P=3/2^-$ $\Sigma_c^* \bar{D}$ and $\Sigma_c^*
\bar{D}^*$ molecules are also discussed in the heavy quark limit, and find that
the $\Sigma_c^* \bar{D}$ system for $P_c(4380)$ is possible. More experimental
information on spin-parities and partial decay widths and theoretical
investigations on other decay modes are needed to clarify the nature of the two
$P_c$ states.


title:
Learnt quasi-transitive similarity for retrieval from large collections
  of faces

abstract:
  We are interested in identity-based retrieval of face sets from large
unlabelled collections acquired in uncontrolled environments. Given a baseline
algorithm for measuring the similarity of two face sets, the meta-algorithm
introduced in this paper seeks to leverage the structure of the data corpus to
make the best use of the available baseline. In particular, we show how partial
transitivity of inter-personal similarity can be exploited to improve the
retrieval of particularly challenging sets which poorly match the query under
the baseline measure. We: (i) describe the use of proxy sets as a means of
computing the similarity between two sets, (ii) introduce transitivity
meta-features based on the similarity of salient modes of appearance variation
between sets, (iii) show how quasi-transitivity can be learnt from such
features without any labelling or manual intervention, and (iv) demonstrate the
effectiveness of the proposed methodology through experiments on the
notoriously challenging YouTube database and two successful baselines from the
literature.


title:
An integral-factorized implementation of the driven similarity
  renormalization group second-order multireference perturbation theory

abstract:
  We report an efficient implementation of a second-order multireference
perturbation theory based on the driven similarity renormalization group
(DSRG-MRPT2) [C. Li and F. A. Evangelista, J. Chem. Theory Comput. 11, 2097
(2015)]. Our implementation employs factorized two-electron integrals to avoid
storage of large four-index intermediates. It also exploits the block structure
of the reference density matrices to reduce the computational cost to that of
second-order M{\o}ller$-$Plesset perturbation theory. Our new DSRG-MRPT2
implementation is benchmarked on ten naphthyne isomers using basis sets up to
quintuple-$\zeta$ quality. We find that the singlet-triplet splittings
($\Delta_\text{ST}$) of the naphthyne isomers strongly depend on the
equilibrium structures. For a consistent set of geometries, the
$\Delta_\text{ST}$ values predicted by the DSRG-MRPT2 are in good agreements
with those computed by the reduced multireference coupled cluster theory with
singles, doubles, and perturbative triples.


title: Optimal Auctions for Negatively Correlated Items

abstract:
  We consider the problem of designing revenue-optimal auctions for selling two
items and bidders' valuations are independent among bidders but negatively
correlated among items.
  In this paper, we obtain the closed-form optimal auction for this setting, by
directly addressing the two difficulties above. In particular, the first
difficulty is that when pointwise maximizing virtual surplus under
multi-dimensional feasibility (i.e., the Border feasibility), (1) neither the
optimal interim allocation is trivially monotone in the virtual value, (2) nor
the virtual value is monotone in the bidder's type. As a result, the optimal
interim allocations resulting from virtual surplus maximization no longer
guarantees BIC. To address (1), we prove a generalization of Border's theorem
and show that optimal interim allocation is indeed monotone in the virtual
value. To address (2), we adapt Myerson's ironing procedure to this setting by
redefining the (ironed) virtual value as a function of the lowest utility
point. The second difficulty, perhaps a more challenging one, is that the
lowest utility type in general is no longer at the endpoints of the type
interval. To address this difficulty, we show by construction that there exist
an allocation rule and an induced lowest utility type such that they form a
solution of the virtual surplus maximization and in the meanwhile guarantees
IIR. In the single bidder case, the optimal auction consists of a randomized
bundle menu and a deterministic bundle menu; while in the multiple bidder case,
the optimal auction is a randomization between two extreme mechanisms. The
optimal solutions of our setting can be implemented by a Bayesian IC and IR
auction, however, perhaps surprisingly, the revenue of this auction cannot be
achieved by any (dominant-strategy) IC and IR auction.


title: Optically Thin Metallic Films for High-radiative-efficiency Plasmonics

abstract:
  Plasmonics enables deep-subwavelength concentration of light and has become
important for fundamental studies as well as real-life applications. Two major
existing platforms of plasmonics are metallic nanoparticles and metallic films.
Metallic nanoparticles allow efficient coupling to far field radiation, yet
their synthesis typically leads to poor material quality. Metallic films offer
substantially higher quality materials, but their coupling to radiation is
typically jeopardized due to the large momentum mismatch with free space. Here,
we propose and theoretically investigate optically thin metallic films as an
ideal platform for high-radiative-efficiency plasmonics. For far-field
scattering, adding a thin high-quality metallic substrate enables a higher
quality factor while maintaining the localization and tunability that the
nanoparticle provides. For near-field spontaneous emission, a thin metallic
substrate, of high quality or not, greatly improves the field overlap between
the emitter environment and propagating surface plasmons, enabling high-Purcell
(total enhancement > $10^4$), high-quantum-yield (> 50 %) spontaneous emission,
even as the gap size vanishes (3$\sim$5 nm). The enhancement has almost
spatially independent efficiency and does not suffer from quenching effects
that commonly exist in previous structures.


title:
Asymptotic behavior of $\ell_p$-based Laplacian regularization in
  semi-supervised learning

abstract:
  Given a weighted graph with $N$ vertices, consider a real-valued regression
problem in a semi-supervised setting, where one observes $n$ labeled vertices,
and the task is to label the remaining ones. We present a theoretical study of
$\ell_p$-based Laplacian regularization under a $d$-dimensional geometric
random graph model. We provide a variational characterization of the
performance of this regularized learner as $N$ grows to infinity while $n$
stays constant, the associated optimality conditions lead to a partial
differential equation that must be satisfied by the associated function
estimate $\hat{f}$. From this formulation we derive several predictions on the
limiting behavior the $d$-dimensional function $\hat{f}$, including (a) a phase
transition in its smoothness at the threshold $p = d + 1$, and (b) a tradeoff
between smoothness and sensitivity to the underlying unlabeled data
distribution $P$. Thus, over the range $p \leq d$, the function estimate
$\hat{f}$ is degenerate and "spiky," whereas for $p\geq d+1$, the function
estimate $\hat{f}$ is smooth. We show that the effect of the underlying density
vanishes monotonically with $p$, such that in the limit $p = \infty$,
corresponding to the so-called Absolutely Minimal Lipschitz Extension, the
estimate $\hat{f}$ is independent of the distribution $P$. Under the assumption
of semi-supervised smoothness, ignoring $P$ can lead to poor statistical
performance, in particular, we construct a specific example for $d=1$ to
demonstrate that $p=2$ has lower risk than $p=\infty$ due to the former penalty
adapting to $P$ and the latter ignoring it. We also provide simulations that
verify the accuracy of our predictions for finite sample sizes. Together, these
properties show that $p = d+1$ is an optimal choice, yielding a function
estimate $\hat{f}$ that is both smooth and non-degenerate, while remaining
maximally sensitive to $P$.


title: An open day in the metric space

abstract:
  We report on a workshop for grade eleven high school students, which took
place in the framework of a university open day. During the workshop the
participants first discovered the key properties of the intuitive concept of
distance from real life examples. After this preparation, the formal definition
of a metric space was introduced and discussed in small groups by means of
problem-oriented exercise sessions.


title:
Point Counting on Non-Hyperelliptic Genus 3 Curves with Automorphism
  Group $\mathbb{Z} / 2 \mathbb{Z}$ using Monsky-Washnitzer Cohomology

abstract:
  We describe an algorithm to compute the zeta function of any
non-hyperelliptic genus 3 plane curve $C$ over a finite field with automorphism
group $G = \mathbb{Z} / 2 \mathbb{Z}$. This algorithm computes in the
Monsky-Washnitzer cohomology of~the curve. Using the relation between the
Monsky-Washnitzer cohomology of $C$ and its quotient $E := C/G$, the
computation splits into 2 parts: one in a subspace of the Monsky-Washnitzer
cohomology and a second which reduces to the point counting on an elliptic
curve $E$. The former corresponds to the dimension $2$ abelian surface
$\mathrm{ker}(\mathrm{Jac}(C) \rightarrow E)$, on which we can compute with
lower precision and with matrices of smaller dimension. Hence we obtain a
faster algorithm than working directly on the curve $C$.


title: MacroBase: Prioritizing Attention in Fast Data

abstract:
  As data volumes continue to rise, manual inspection is becoming increasingly
untenable. In response, we present MacroBase, a data analytics engine that
prioritizes end-user attention in high-volume fast data streams. MacroBase
enables efficient, accurate, and modular analyses that highlight and aggregate
important and unusual behavior, acting as a search engine for fast data.
MacroBase is able to deliver order-of-magnitude speedups over alternatives by
optimizing the combination of explanation and classification tasks and by
leveraging a new reservoir sampler and heavy-hitters sketch specialized for
fast data streams. As a result, MacroBase delivers accurate results at speeds
of up to 2M events per second per query on a single core. The system has
delivered meaningful results in production, including at a telematics company
monitoring hundreds of thousands of vehicles.


title:
The Value of A Statistical Life in Absence of Panel Data: What can we
  do?

abstract:
  In this paper I show how reliable estimates of the Value of a Statistical
Life (VSL) can be obtained using cross sectional data using Garen's
instrumental variable (IV) approach. The increase in the range confidence
intervals due to the IV setup can be reduced by a factor of 3 by using a proxy
to risk attitude. In order state the "precision" of the cross sectional VSL
estimates I estimate the VSL using Chilean panel data and use them as benchmark
for different cross sectional specifications. The use of the proxy eliminates
need for using hard-to-find instruments for the job risk level and narrows the
confidence intervals for the workers in the Chilean labor market for the year
2009.


title:
An Application of the Nash-Moser Theorem to the Vacuum Boundary Problem
  of Gaseous Stars

abstract:
  We have been studying spherically symmetric motions of gaseous stars with
physical vacuum boundary governed either by the Euler-Poisson equations in the
non-relativistic theory or by the Einstein-Euler equations in the relativistic
theory. The problems are to construct solutions whose first approximations are
small time-periodic solutions to the linearized problem at an equilibrium and
to construct solutions to the Cauchy problem near an equilibrium. These
problems can be solved when $1/(\gamma-1)$ is an integer, where $\gamma$ is the
adiabatic exponent of the gas near the vacuum, by the formulation by R.
Hamilton of the Nash-Moser theorem. We discuss on an application of the
formulation by J. T. Schwartz of the Nash-Moser theorem to the case in which
$1/(\gamma-1)$ is not an integer but sufficiently large.


title:
Without-Replacement Sampling for Stochastic Gradient Methods:
  Convergence Results and Application to Distributed Optimization

abstract:
  Stochastic gradient methods for machine learning and optimization problems
are usually analyzed assuming data points are sampled \emph{with} replacement.
In practice, however, sampling \emph{without} replacement is very common,
easier to implement in many cases, and often performs better. In this paper, we
provide competitive convergence guarantees for without-replacement sampling,
under various scenarios, for three types of algorithms: Any algorithm with
online regret guarantees, stochastic gradient descent, and SVRG. A useful
application of our SVRG analysis is a nearly-optimal algorithm for regularized
least squares in a distributed setting, in terms of both communication
complexity and runtime complexity, when the data is randomly partitioned and
the condition number can be as large as the data size per machine (up to
logarithmic factors). Our proof techniques combine ideas from stochastic
optimization, adversarial online learning, and transductive learning theory,
and can potentially be applied to other stochastic optimization and learning
problems.


title: A workshop for high school students on naive set theory

abstract:
  In this article we present the prototype of a workshop on naive set theory
designed for high school students in or around the seventh year of primary
education. Our concept is based on two events which the author organized in
2006 and 2010 for students of elementary school and high school, respectively.
The article also includes a practice report on the two workshops.


title:
Hierarchical Role-Based Access Control with Homomorphic Encryption for
  Database as a Service

abstract:
  Database as a service provides services for accessing and managing customers
data which provides ease of access, and the cost is less for these services.
There is a possibility that the DBaaS service provider may not be trusted, and
data may be stored on untrusted server. The access control mechanism can
restrict users from unauthorized access, but in cloud environment access
control policies are more flexible. However, an attacker can gather sensitive
information for a malicious purpose by abusing the privileges as another user
and so database security is compromised. The other problems associated with the
DBaaS are to manage role hierarchy and secure session management for query
transaction in the database. In this paper, a role-based access control for the
multitenant database with role hierarchy is proposed. The query is granted with
least access privileges, and a session key is used for session management. The
proposed work protects data from privilege escalation and SQL injection. It
uses the partial homomorphic encryption (Paillier Encryption) for the
encrypting the sensitive data. If a query is to perform any operation on
sensitive data, then extra permissions are required for accessing sensitive
data. Data confidentiality and integrity are achieved using the role-based
access control with partial homomorphic encryption.


title: A jammer's perspective of reachability and LQ optimal control

abstract:
  This article treats two problems dealing with control of linear systems in
the presence of a jammer that can sporadically turn off the control signal. The
first problem treats the standard reachability problem, and the second treats
the standard linear quadratic regulator problem under the above class of
jamming signals. We provide necessary and sufficient conditions for optimality
based on a nonsmooth Pontryagin maximum principle.


title: Periodically Driven Adiabatic Bipolarons

abstract:
  Small lattice bipolarons driven by external harmonic fields are considered in
the adiabatic approximation. Resonant excitation of ions modulates the trapping
potential and promotes hole transfer between neighboring atomic layers. It
leads to a dramatic decrease of the apparent bipolaron mass compared to the
undriven case. This effect offers an explanation for dynamic stabilization of
superconductivity at high temperatures recently observed in layered cuprates.


title:
Soft gamma-ray repeaters and anomalous X-ray pulsars as highly
  magnetized white dwarfs

abstract:
  We explore the possibility that soft gamma-ray repeaters (SGRs) and anomalous
X-ray pulsars (AXPs) are powered by highly magnetized white dwarfs (B-WDs). We
take a sample of SGRs and AXPs and provide the possible parameter space in
mass, radius, and surface magnetic field based on their observed properties
(period and its derivative) and the assumption that these sources obey the
mass-radius relation derived for the B-WDs. The radius and magnetic field of
B-WDs are adequate to explain energies in SGRs/AXPs as the rotationally powered
energy. In addition, B-WDs also adequately explain the perplexing radio
transient GCRT J1745-3009 as a white dwarf pulsar. Note that the radius and
magnetic fields of B-WDs are neither extreme (unlike of highly magnetized
neutron stars) nor ordinary (unlike of magnetized white dwarfs, yet following
the Chandrasekhar's mass-radius relation (C-WDs)). In order to explain
SGRs/AXPs, while the highly magnetized neutron stars require an extra,
observationally not well established yet, source of energy, the C-WDs predict
large ultra-violet luminosity which is observationally constrained from a
strict upper limit. Finally, we provide a set of basic differences between the
magnetar and B-WD hypotheses for SGRs/AXPs.


title: Distributed Estimation of Dynamic Parameters : Regret Analysis

abstract:
  This paper addresses the estimation of a time- varying parameter in a
network. A group of agents sequentially receive noisy signals about the
parameter (or moving target), which does not follow any particular dynamics.
The parameter is not observable to an individual agent, but it is globally
identifiable for the whole network. Viewing the problem with an online
optimization lens, we aim to provide the finite-time or non-asymptotic analysis
of the problem. To this end, we use a notion of dynamic regret which suits the
online, non-stationary nature of the problem. In our setting, dynamic regret
can be recognized as a finite-time counterpart of stability in the mean- square
sense. We develop a distributed, online algorithm for tracking the moving
target. Defining the path-length as the consecutive differences between target
locations, we express an upper bound on regret in terms of the path-length of
the target and network errors. We further show the consistency of the result
with static setting and noiseless observations.


title:
Haagerup's inequality and additivity violation of the Minimum Output
  Entropy

abstract:
  We give a simple and conceptual proof of the fact that random unitary
channels yield violation of the Minimum Output Entropy additivity. The proof
relies on strong convergence of random unitary matrices and Haagerup's
inequality.


title:
Flag-transitive point-primitive non-symmetric 2-(v,k,2) designs with
  alternating socle

abstract:
  This paper studies flag-transitive point-primitive non-symmetric
$2$-($v,k,2$) designs. We prove that if $\mathcal{D}$ is a non-trivial
non-symmetric $2$-$(v,k,2)$ design admitting a flag-transitive point-primitive
automorphism group $G$ with $Soc(G)=A_{n}$ for $n\geq5$, then $\mathcal{D}$ is
a $2$-$(6,3,2)$ or $2$-$(10,4,2)$ design.


title: The Effects of Orographic Geometry on Supercell Thunderstorms

abstract:
  The effect of elongated bell-shaped mountain orientation on supercell
thunderstorms is numerically investigated using the Bryan Cloud Model 1 (CM1).
The orography is varied by three mountain heights and is varied in four
different positions, effectively producing 12 different terrain configurations.
It is found that the different orientations produce variations in the supercell
life cycle with shorter cycles for higher inflow rates. Furthermore, these
cycles are associated with the storm reaching its minimum intensity just after
a peak rain period. Moreover, the effect of stronger inflow was seen before
direct storm-terrain interactions started. The higher inflow also played a
significant role in increasing rainfall rate and areal extent, to the point
that further convection, associated with the cold pool, was triggered adding to
rainfall amount. Using a stricter form of the National Weather Service Tornado
Detection Algorithm to investigate the tornadic nature of simulated supercells;
it is found that terrain blocking effects are dominative and that elongating
the terrain axis approximately parallel to the propagation vector produced the
strongest potential to generate a tornadic supercell thunderstorm. Although the
simulated case with the highest mountain produced the most tornadic
thunderstorms it is seen that increasing the terrain height alone is not
sufficient to make tornadogenesis more probable as more tornadic supercells
were simulated with lower heights compared to moderate terrain heights.


title: Colored Spanning Graphs for Set Visualization

abstract:
  We study an algorithmic problem that is motivated by ink minimization for
sparse set visualizations. Our input is a set of points in the plane which are
either blue, red, or purple. Blue points belong exclusively to the blue set,
red points belong exclusively to the red set, and purple points belong to both
sets. A \emph{red-blue-purple spanning graph} (RBP spanning graph) is a set of
edges connecting the points such that the subgraph induced by the red and
purple points is connected, and the subgraph induced by the blue and purple
points is connected.
  We study the geometric properties of minimum RBP spanning graphs and the
algorithmic problems associated with computing them. Specifically, we show that
the general problem can be solved in polynomial time using matroid techniques.
In addition, we discuss more efficient algorithms for the case in which points
are located on a line or a circle, and also describe a fast $(\frac
12\rho+1)$-approximation algorithm, where $\rho$ is the Steiner ratio.


title: A Repeating Fast Radio Burst

abstract:
  Fast Radio Bursts are millisecond-duration astronomical radio pulses of
unknown physical origin that appear to come from extragalactic distances.
Previous follow-up observations have failed to find additional bursts at the
same dispersion measures (i.e. integrated column density of free electrons
between source and telescope) and sky position as the original detections. The
apparent non-repeating nature of the fast radio bursts has led several authors
to hypothesise that they originate in cataclysmic astrophysical events. Here we
report the detection of ten additional bursts from the direction of FRB121102,
using the 305-m Arecibo telescope. These new bursts have dispersion measures
and sky positions consistent with the original burst. This unambiguously
identifies FRB121102 as repeating and demonstrates that its source survives the
energetic events that cause the bursts. Additionally, the bursts from FRB121102
show a wide range of spectral shapes that appear to be predominantly intrinsic
to the source and which vary on timescales of minutes or shorter. While there
may be multiple physical origins for the population of fast radio bursts, the
repeat bursts with high dispersion measure and variable spectra specifically
seen from FRB121102 support models that propose an origin in a young, highly
magnetised, extragalactic neutron star.


title: The equivalence of two Seiberg-Witten Floer homologies

abstract:
  We show that monopole Floer homology (as defined by Kronheimer and Mrowka) is
isomorphic to the S^1-equivariant homology of the Seiberg-Witten Floer spectrum
constructed by the second author.


title:
Some essential skills and their combination in an architecture for a
  cognitive and interactive robot

abstract:
  The topic of joint actions has been deeply studied in the context of
Human-Human interaction in order to understand how humans cooperate. Creating
autonomous robots that collaborate with humans is a complex problem, where it
is relevant to apply what has been learned in the context of Human-Human
interaction. The question is what skills to implement and how to integrate them
in order to build a cognitive architecture, allowing a robot to collaborate
efficiently and naturally with humans. In this paper, we first list a set of
skills that we consider essential for Joint Action, then we analyze the problem
from the robot's point of view and discuss how they can be instantiated in
human-robot scenarios. Finally, we open the discussion on how to integrate such
skills into a cognitive architecture for human-robot collaborative problem
solving and task achievement.


title: Floer homology and covering spaces

abstract:
  We prove a Smith-type inequality for regular covering spaces in monopole
Floer homology. Using the monopole Floer / Heegaard Floer correspondence, we
deduce that if a 3-manifold Y admits a p^n-sheeted regular cover that is a
Z/pZ-L-space (for p prime), then Y is a Z/pZ-L-space. Further, we obtain
constraints on surgeries on a knot being regular covers over other surgeries on
the same knot, and over surgeries on other knots.


title: Optimal Scheduling for Incentive WiFi Offloading under Energy Constraint

abstract:
  WiFi offloading, where mobile device users (e.g., smart phone users) transmit
packets through WiFi networks rather than cellular networks, is a promising
solution to alleviating the heavy traffic burden of cellular networks due to
data explosion. However, since WiFi networks are intermittently available, a
mobile device user in WiFi offloading usually needs to wait for WiFi connection
and thus experiences longer delay of packet transmission. To motivate users to
participate in WiFi offloading, cellular network operators give incentives
(rewards like coupons, e-coins) to users who wait for WiFi connection and
transmit packets through WiFi networks.
  In this paper, we aim at maximizing users' rewards while meeting constraints
on queue stability and energy consumption. However, we face scheduling
challenges from random packet arrivals, intermittent WiFi connection and time
varying wireless link states. To address these challenges, we first formulate
the problem as a stochastic optimization problem. We then propose an optimal
scheduling policy, named Optimal scheduling Policy under Energy Constraint
(OPEC), which makes online decisions as to when to delay packet transmission to
wait for WiFi connection and which wireless link (WiFi link or cellular link)
to transmit packets on. OPEC automatically adapts to random packet arrivals and
time varying wireless link states, not requiring a priori knowledge of packet
arrival and wireless link probabilities. As verified by simulations, OPEC
scheduling policy can achieve the maximum rewards while keeping queue stable
and meeting energy consumption constraint.


title: Galactic Spiral Arms by Swing Amplification

abstract:
  Based on the swing amplification model of Julian and Toomre (1966), we
investigate the formation and structure of stellar spirals in disk galaxies. We
calculate the pitch angle, wavelengths, and amplification factor of the most
amplified mode. We also obtain the fitting formulae of these quantities as a
function of the epicycle frequency and Toomre's $Q$. As the epicycle frequency
increases, the pitch angle and radial wavelength increases, while the azimuthal
wavelength decreases. The pitch angle and radial wavelength increases with $Q$,
while the azimuthal wavelength weakly depends on $Q$. The amplification factor
decreases with $Q$ rapidly. In order to confirm the swing amplification model,
we perform local $N$-body simulations. The wavelengths and pitch angle by the
swing amplification model are in good agreement with those by $N$-body
simulations. The dependence of the amplification factor on the epicycle
frequency in $N$-body simulations is generally consistent with that in the
swing amplification model. Using these results, we estimate the number of
spiral arms as a function of the shear rate. The number of spiral arms
increases with the shear rate if the disk to halo mass ratio is fixed.


title:
A Theorem on Multi-Objective Optimization Approach for Bit Allocation of
  Scalable Coding

abstract:
  In the current work, we have formulated the optimal bit-allocation problem
for a scalable codec of images or videos as a constrained vector-valued
optimization problem and demonstrated that there can be many optimal solutions,
called Pareto optimal points. In practice, the Pareto points are derived via
the weighted sum scalarization approach. An important question which arises is
whether all the Pareto optimal points can be derived using the scalarization
approach? The present paper provides a sufficient condition on the
rate-distortion function of each resolution of a scalable codec to address the
above question. The result indicated that if the rate-distortion function of
each resolution is strictly decreasing and convex and the Pareto points form a
continuous curve, then all the optimal Pareto points can be derived by using
the scalarization method.


title: Decapitation via Digital Epidemics: A Bio-Inspired Transmissive Attack

abstract:
  The evolution of communication technology and the proliferation of electronic
devices have rendered adversaries powerful means for targeted attacks via all
sorts of accessible resources. In particular, owing to the intrinsic
interdependency and ubiquitous connectivity of modern communication systems,
adversaries can devise malware that propagates through intermediate hosts to
approach the target, which we refer to as transmissive attacks. Inspired by
biology, the transmission pattern of such an attack in the digital space much
resembles the spread of an epidemic in real life. This paper elaborates
transmissive attacks, summarizes the utility of epidemic models in
communication systems, and draws connections between transmissive attacks and
epidemic models. Simulations, experiments, and ongoing research challenges on
transmissive attacks are also addressed.


title:
Generalized Analysis of Convergence of Absolute Trust in Peer to Peer
  Networks

abstract:
  Open and anonymous nature of peer to peer networks provides an opportunity to
malicious peers to behave unpredictably in the network. This leads the lack of
trust among the peers. To control the behavior of peers in the network,
reputation system can be used. In a reputation system, aggregation of trust is
a primary issue. Algorithm for aggregation of trust should be designed such
that, it can converge to a certain finite value. Absolute Trust is one of the
algorithm, which is used for the aggregation of trust in peer to peer networks.
In this letter, we present the generalized analysis of convergence of the
Absolute Trust algorithm.


title: Hyperbolic type distances in starlike domains

abstract:
  We study the growth of hyperbolic type distances in starlike domains. We
derive estimates for various hyperbolic type distances and consider the
asymptotic sharpness of the estimates.


title:
Removal of phase transition of the Chebyshev quadratic and
  thermodynamics of H\'enon-like maps near the first bifurcation

abstract:
  We treat a problem at the interface of dynamical systems and equilibrium
statistical physics. It is well-known that the geometric pressure function
$$t\in\mathbb R\mapsto \sup_{\mu}\left\{h_\mu(T_2)-t\int\log
|dT_2(x)|d\mu(x)\right\}$$ of the Chebyshev quadratic map $T_2(x)=1-2x^2$
$(x\in\mathbb R)$ is not differentiable at $t=-1$. We show that this phase
transition can be "removed", by an arbitrarily small singular perturbation of
the map $T_2$ into H\'enon-like diffeomorphisms. A proof of this result relies
on an elaboration of the well-known inducing techniques adapted to H\'enon-like
dynamics near the first bifurcation.


title:
Optical diffraction tomography techniques for the study of cell
  pathophysiology

abstract:
  Three-dimensional imaging of biological cells is crucial for the
investigation of cell biology, provide valuable information to reveal the
mechanisms behind pathophysiology of cells and tissues. Recent advances in
optical diffraction tomography (ODT) have demonstrated the potential for the
study of various cells with its unique advantages of quantitative and
label-free imaging capability. To provide insight on this rapidly growing field
of research and to discuss its applications in biology and medicine, we present
the summary of the ODT principle and highlight recent studies utilizing ODT
with the emphasis on the applications to the pathophysiology of cells.


title:
Scattering optical elements: stand-alone optical elements exploiting
  multiple light scattering

abstract:
  Optical design and fabrication techniques are crucial for making optical
elements. From conventional lenses to diffractive optical elements, and to
recent metasurfaces, various types of optical elements have been proposed to
manipulate light where optical materials are fabricated into desired
structures. Here, we propose a scattering optical element (SOE) which exploits
multiple light scattering and wavefront shaping. Instead of fabricating optical
materials, the SOE consists of a disordered medium and a photopolymer-based
wavefront recorder, with shapes the wavefront of impinging light on demand.
With the proposed stand-alone SOEs, we experimentally demonstrate control of
various properties of light, including intensity, polarisation, spectral
frequency and near field. Due to the tremendous freedom brought about by
disordered media, the proposed approach will provide unexplored routes to
manipulate arbitrary optical fields in stand-alone optical elements.


title:
Schr\"odinger Operators with $\delta$-interactions in a Space of
  Vector-Valued Functions

abstract:
  We study spectral properties of Schr\"odinger operators with
$\delta$-interactions on a semi-axis by using the theory of boundary triplets
and the corresponding Weyl functions. We establish a connection between
spectral properties (deficiency indices, self-adjointness, semiboundedness,
discreteness of spectra, resolvent comparability etc.) of Schr\"odinger
operators with point interactions and a special class of block Jacobi matrices.


title: Gravitation, holographic principle, and extra dimensions

abstract:
  Within the context of Newton's theory of gravitation, restricted to
point-like test particles and central bodies, stable circular orbits in
ordinary space are related to stable circular paths on a massless, unmovable,
undeformable vortex-like surface, under the action of a tidal gravitational
field along the symmetry axis. An interpretation is made in the light of a
holographic principle, in the sense that motions in ordinary space are
connected with motions on a selected surface and vice versa. Then ordinary
space is conceived as a 3-hypersurface bounding a $n$-hypervolume where
gravitation takes origin, within a $n$-hyperspace. The extension of the
holographic principle to extra dimensions implies the existence of a minimum
distance where test particles may still be considered as distinct from the
central body. Below that threshold, it is inferred test particles lose theirs
individuality and "glue" to the central body via unification of the four known
interactions and, in addition, (i) particles can no longer be conceived as
point-like but e.g., strings or membranes, and (ii) quantum effects are
dominant and matter turns back to a pre-big bang state. A more detailed
formulation including noncircular motions within the context of general
relativity, together with further knowledge on neutron stars, quark stars and
black holes, would provide further insight on the formulation of quantum
gravity.


title: Randomly Weighted Averages: A Multivariate Case

abstract:
  Stochastic linear combinations of some random vectors are studied where the
distribution of the random vectors and the joint distribution of their
coefficients are Dirichlet. A method is provided for calculating the
distribution of these combinations which has been studied before by some
authors. Our main result is a generalization of some existing results with a
simpler proof.


title:
Arbitrarily small perturbations of Dirichlet Laplacians are quantum
  unique ergodic

abstract:
  Given an Euclidean domain with very mild regularity properties, we prove that
there exist perturbations of the Dirichlet Laplacian of the form
$-(I+S_\epsilon)\Delta$ with $\|S_\epsilon\|_{L^2\to L^2}\leq \epsilon$ whose
high energy eigenfunctions are quantum uniquely ergodic (QUE). Moreover, if we
impose stronger regularity on the domain, the same result holds with
$\|S_\epsilon\|_{L^2\to H^\gamma}\leq \epsilon$ for $\gamma>0$ depending on the
domain. We also give a proof of a local Weyl law for domains with rough
boundaries.


title:
CP violation in the extension of SM with a complex singlet scalar and
  vector quarks

abstract:
  We consider the simplest extension of the SM with a complex singlet and a
pair of heavy doublet vector quarks, the so-called cSMCS model. In this model,
the CP violation can emerge spontaneously as a consequence of the
time-dependent phase of the complex singlet vacuum expectation value and the
mass mixing of the SM and heavy vector quarks. In our model, the CP-violating
time-dependent phase depends on the Higgs field within the bubble-wall via the
Higgs-singlet coupling that can directly explain the observed baryon-to-entropy
ratio $\sim 9\times 10^{-11}$. Additionally, as a result of the mixing between
vector quarks and SM quarks, the tree level Flavour Changing Neutral Currents
and the charged-current decay channels $t' \to Wb, \, Zt, \, h_{i} t$ and $b'
\to Wt, \, Zb, \, h_{i} b$ would arise that are well constrained by
experimental data. We investigate the implications of these constraints on the
total cross-section for the production of heavy vector quark pairs via $pp \to
t'\bar{t'}$ and $pp \to b'\bar{b'}$ channels and obtain the bounds on the heavy
quark masses for this model. Accordingly, we show the contribution of these
heavy quarks in the Higgs bosons signal strength, $\mathcal{R}_{\gamma\gamma}$,
as well as corrections to the gauge boson propagators.


title:
Error correction in multi-fidelity molecular dynamics simulations using
  functional uncertainty quantification

abstract:
  We use functional, Fr\'echet, derivatives to quantify how thermodynamic
outputs of a molecular dynamics (MD) simulation depend on the potential used to
compute atomic interactions. Our approach quantifies the sensitivity of the
quantities of interest with respect to the input functions as opposed to its
parameters as is done in typical uncertainty quantification methods. We show
that the functional sensitivity of the average potential energy and pressure in
isothermal, isochoric MD simulations using Lennard-Jones two-body interactions
can be used to accurately predict those properties for other interatomic
potentials (with different functional forms) without re-running the
simulations. This is demonstrated under three different thermodynamic
conditions, namely a crystal at room temperature, a liquid at ambient pressure,
and a high pressure liquid. The method provides accurate predictions as long as
the change in potential can be reasonably described to first order and does not
significantly affect the region in phase space explored by the simulation. The
functional uncertainty quantification approach can be used to estimate the
uncertainties associated with constitutive models used in the simulation and to
correct predictions if a more accurate representation becomes available.


title: Decentralized Detection in Energy Harvesting Wireless Sensor Networks

abstract:
  We consider a decentralized hypothesis testing problem in which several
peripheral energy harvesting sensors are arranged in parallel. Each sensor
makes a noisy observation of a time varying phenomenon, and sends a message
about the present hypothesis towards a fusion center at each time instance t.
The fusion center, using the aggregate of the received messages during the time
instance t, makes a decision about the state of the present hypothesis. We
assume that each sensor is an energy harvesting device and is capable of
harvesting all the energy it needs to communicate from its environment. Our
contribution is to formulate and analyze the decentralized detection problem
when the energy harvesting sensors are allowed to form a long term energy usage
policy. Our analysis is based on a queuing-theoretic model for the battery.
Then, by using numerical simulations, we show how the resulting performance
differs from the energy unconstrained case.


title: Construction of schemoids from posets

abstract:
  A schemoid is a generalization of association schemes from the point of view
of small categories. In this article, we discuss schemoid structures for two
kinds of small categories; the canonical small category defined by a poset, and
another small category which arises a poset. We also discuss the schemoid
algebra, that is an analogue of the Bose--Mesner algebra for an association
scheme, for them.


title: MHz Gravitational Waves from Short-term Anisotropic Inflation

abstract:
  We reveal the universality of short-term anisotropic inflation. As a
demonstration, we study inflation with an exponential type gauge kinetic
function which is ubiquitous in models obtained by dimensional reduction from
higher dimensional fundamental theory. It turns out that an anisotropic
inflation universally takes place in the later stage of conventional inflation.
Remarkably, we find that primordial gravitational waves with a peak amplitude
around $10^{-26}$ ~ $10^{-27}$ are copiously produced in high-frequency bands
10MHz~100MHz. If we could detect such gravitational waves in future, we would
be able to probe higher dimensional fundamental theory.


title: Measurements of the Soft Gamma-ray Emission from SN2014J with Suzaku

abstract:
  The hard X-ray detector (HXD) onboard {\it Suzaku} measured soft
$\gamma$-rays from the Type Ia supernova SN2014J at $77\pm2$ days after the
explosion. Although the confidence level of the signal is about 90\% (i.e., $2
\sigma$), the $3 \sigma$ upper limit has been derived at $< 2.2 \times10^{-4}$
ph s$^{-1}$ cm$^{-2}$ in the 170 -- 250 keV band as the first independent
measurement of soft $\gamma$-rays with an instrument other than {\it INTEGRAL}.
For this analysis, we have examined the reproducibility of the NXB model of
HXD/GSO using blank sky data. We find that the residual count rate in the 90 --
500 keV band is distributed around an average of 0.19\% with a standard
deviation of 0.42\% relative to the NXB rate. The averaged residual signals are
consistent with that expected from the cosmic X-ray background. The flux of
SN2014J derived from {\it Suzaku} measurements taken in one snapshot at
$t=77\pm2$ days after the explosion is consistent with the {\it INTEGRAL}
values averaged over the period between $t=$50 and 100 days and also with
explosion models of single or double degenerate scenarios. Being sensitive to
the total ejecta mass surrounding the radioactive material, the ratio between
continuum and line flux in the soft gamma-ray regime might distinguish
different progenitor models. The {\it Suzaku} data have been examined with this
relation at $t=77\pm2$ days, but could not distinguish models between single
and double degenerate-progenitors. We disfavor explosion models with larger
$^{56}$Ni masses than 1 $M_\odot$, from our $1 \sigma$ error on the 170-250 keV
X-ray flux of $(1.2\pm0.7) \times10^{-4}$ ph s$^{-1}$ cm$^{-2}$.


title:
Search for anomalous couplings via single top quark production in
  association with a photon at LHC

abstract:
  Considering the experimental constraints given by CMS collaboration at
$\sqrt{s} = 8$ TeV on the strength of top quark flavour-changing
neutral-current (FCNC) couplings $tq\gamma$ and $tqg$, we investigate the
production of top quark in association with a photon and carry out a full
simulation for the signals $\ell\nu b\gamma$ and $jjb\gamma$ at 14 TeV LHC. In
our numerical analysis, the contributions of single top production with a
photon radiation off the top decay products are also included. The discovery
potential for anomalous couplings $tq\gamma$ and $tqg$ with an integrated
luminosity of 100 fb$^{-1}$ are examined in detail.


title:
Blocking temperature of interacting magnetic nanoparticles with uniaxial
  and cubic anisotropies from Monte Carlo simulations

abstract:
  The low temperature behavior of densely packed interacting spherical single
domain nanoparticles (MNP) is investigated by Monte Carlo simulations in the
framework of an effective one spin model. The particles are distributed through
a hard sphere like distribution with periodic boundary conditions and interact
through the dipole dipole interaction (DDI) with an anisotropy energy including
both cubic and uniaxial symmetry components. The cubic component is shown to
play a sizable role on the value of the blocking temperature $T_b$ only when
the MNP easy axes are parallel to the cubic easy direction ([111] direction for
a negative cubic anisotropy constant). The nature of the collective low
temperature state, either ferromagnetic or spin glass like, is found to depend
on the ratio of the anisotropy to the dipolar energies characterizing partly
the disorder in the system.


title:
Pressure-induced phonon freezing in the ZnSeS II-VI mixed crystal:
  phonon-polaritons and ab initio calculations

abstract:
  Near-forward Raman scattering combined with ab initio phonon and bond length
calculations is used to study the phonon-polariton transverse optical modes
(with mixed electrical and mechanical character) of the II-VI ZnSeS mixed
crystal under pressure. The goal of the study is to determine the pressure
dependence of the poorly resolved percolation-type Zn-S Raman doublet of the
three oscillator [1(Zn-Se),2(Zn-S)] ZnSe68S32 mixed crystal, which exhibits a
phase transition at approximately the same pressure as its two end compounds
(~14 GPa, zincblende-to-rocksalt), as determined by high-pressure x-ray
diffraction. We find that the intensity of the lower Zn-S sub-mode of
ZnSe68S32, due to Zn-S bonds vibrating in their own (S-like) environment,
decreases under pressure (Raman scattering), whereas its frequency
progressively converges onto that of the upper Zn- S sub-mode, due to Zn-S
vibrations in the foreign (Se-like) environment (ab initio calculations).
Ultimately, only the latter sub-mode survives. A similar phonon freezing was
earlier evidenced with the well-resolved percolation-type Be-Se doublet of
ZnBeSe [Pradhan et al. Phys. Rev. B 81, 115207 (2010)], that exhibits a large
contrast in the pressure-induced structural transitions of its end compounds.
We deduce that the above collapse and convergence process is intrinsic to the
percolation doublet of a short bond under pressure, at least in a ZnSe-based
mixed crystal, and not due to any pressure-induced structural transition.


title:
Calibration Requirements for Detecting the 21 cm Epoch of Reionization
  Power Spectrum and Implications for the SKA

abstract:
  21 cm Epoch of Reionization observations promise to transform our
understanding of galaxy formation, but these observations are impossible
without unprecedented levels of instrument calibration. We present end-to-end
simulations of a full EoR power spectrum analysis including all of the major
components of a real data processing pipeline: models of astrophysical
foregrounds and EoR signal, frequency-dependent instrument effects, sky-based
antenna calibration, and the full PS analysis. This study reveals that
traditional sky-based per-frequency antenna calibration can only be implemented
in EoR measurement analyses if the calibration model is unrealistically
accurate. For reasonable levels of catalog completeness, the calibration
introduces contamination in otherwise foreground-free power spectrum modes,
precluding a PS measurement. We explore the origin of this contamination and
potential mitigation techniques. We show that there is a strong joint
constraint on the precision of the calibration catalog and the inherent
spectral smoothness of antennae, and that this has significant implications for
the instrumental design of the SKA and other future EoR observatories.


title: Distributive and trimedial quasigroups of order 243

abstract:
  We enumerate three classes of non-medial quasigroups of order $243=3^5$ up to
isomorphism. There are $17004$ non-medial trimedial quasigroups of order $243$
(extending the work of Kepka, B\'en\'eteau and Lacaze), $92$ non-medial
distributive quasigroups of order $243$ (extending the work of Kepka and
N\v{e}mec), and $6$ non-medial distributive Mendelsohn quasigroups of order
$243$ (extending the work of Donovan, Griggs, McCourt, Opr\v{s}al and
Stanovsk\'y).
  The enumeration technique is based on affine representations over commutative
Moufang loops, on properties of automorphism groups of commutative Moufang
loops, and on computer calculations with the \texttt{LOOPS} package in
\texttt{GAP}.


title: Multiple strain-induced phase transitions in LaNiO3 thin films

abstract:
  Strain effects on epitaxial thin films of LaNiO3 grown on different single
crystalline substrates are studied by Raman scattering and first-principles
simulation. New Raman modes, not present in bulk or fully-relaxed films, appear
under both compressive and tensile strains, indicating symmetry reductions.
Interestingly, the Raman spectra and the underlying crystal symmetry for
tensile and compressively strained films are different. Extensive mapping of
LaNiO3 phase stability is addressed by simulations, showing that a variety of
crystalline phases are indeed stabilized under strain which may impact the
electronic orbital hierarchy. The calculated Raman frequencies reproduce the
principal features of the experimental spectra, supporting the validity of the
multiple strain-driven structural transitions predicted by the simulations.


title: Hercules and Wolf 630 Stellar Streams and Galactic Bar Kinematics

abstract:
  We have identified the four most significant features in the UV velocity
distribution of solar neighborhood stars: H1, H2 in the Hercules stream and W1,
W2 in the Wolf 630 stream. We have formulated the problem of determining
several characteristics of the central Galactic bar independently from each of
the identified features by assuming that the Hercules and Wolf 630 streams are
of a bar-induced dynamical nature. The problem has been solved by constructing
2:1 resonant orbits in the rotating bar frame for each star in these streams.
Analysis of the resonant orbits found has shown that the bar pattern speed is
45-55 km/s/kpc, while the bar angle lies within the range 40-60 degrees. The
results obtained are consistent with the view that the Hercules and Wolf 630
streams could be formed by a long-term influence of the Galactic bar leading to
a characteristic bimodal splitting of the UV velocity plane.


title: Exactly realizable desired trajectories

abstract:
  Trajectory tracking of nonlinear dynamical systems with affine open-loop
controls is investigated. The control task is to enforce the system state to
follow a prescribed desired trajectory as closely as possible. We introduce
exactly realizable desired trajectories as these trajectories which can be
tracked exactly by an appropriate control. Exactly realizable trajectories are
characterized mathematically by means of Moore-Penrose projectors constructed
from the input matrix. The approach leads to differential-algebraic systems of
equations and is considerably simpler than the related concept of system
inversion. Furthermore, we identify a particularly simple class of nonlinear
affine control systems. Systems in this class satisfy the so-called linearizing
assumption and share many properties with linear control systems. For example,
conditions for controllability can be formulated in terms of a rank condition
for a controllability matrix analogously to the Kalman rank condition for
linear time-invariant systems.


title:
Gradient Estimates via Rearrangements for Solutions of Some
  Schr\"odinger Equations

abstract:
  In this article, by applying the well known method for dealing with
$p$-Laplace type elliptic boundary value problems, the authors establish a
sharp estimate for the decreasing rearrangement of the gradient of solutions to
the Dirichlet and the Neumann boundary value problems of a class of
Schr\"odinger equations, under the weak regularity assumption on the boundary
of domains. As applications, gradient estimates of these solutions in Lebesgue
spaces and Lorentz spaces are obtained.


title: On a bound of Hoeffding in the complex case

abstract:
  It was proved by Hoeffding in 1963 that a real random variable X confined to
[a, b] satisfies E e^(X--E X) $\le$ e^((b--a)^2/8). We generalise this to
complex random variables.


title:
Electric-Field-Induced Spin Resonance in Antiferromagnetic Insulators:
  Inverse Process of the Dynamical Chiral Magnetic Effect

abstract:
  We propose a realization of the electric-field-induced antiferromagnetic
resonance. We consider three-dimensional antiferromagnetic insulators with
spin-orbit coupling characterized by the existence of a topological term called
the $\theta$ term. By solving the Landau-Lifshitz-Gilbert equation in the
presence of the $\theta$ term, we show that, in contrast to conventional
methods using ac magnetic fields, the antiferromagnetic resonance state is
realized by ac electric fields along with static magnetic fields. This
mechanism can be understood as the inverse process of the dynamical chiral
magnetic effect, an alternating current generation by magnetic fields. In other
words, we propose a way to electrically induce the dynamical axion field in
condensed matter. We discuss a possible experiment to observe our proposal,
which utilizes the spin pumping from the antiferromagnetic insulator into a
heavy metal contact.

categories: cond-mat.str-el cond-mat.mes-hall cond-mat.mtrl-sci hep-lat hep-ph


title:
Orientifold ABJM Matrix Model: Chiral Projections and Worldsheet
  Instantons

abstract:
  We study the partition function of the orientifold ABJM theory, which is a
superconformal Chern-Simons theory associated with the orthosymplectic
supergroup. We find that the partition function associated with any
orthosymplectic supergroup can be realized as the partition function of a Fermi
gas system whose density matrix is identical to that associated with the
corresponding unitary supergroup with a projection to the even or odd
chirality. Furthermore we propose an identity which gives directly all of the
Gopakumar-Vafa invariants for the worldsheet instanton effects in the chirally
projected theories.


title:
Near-forward Raman selection rules of the phonon-polariton created by
  alloying in (Zn,Be)Se

abstract:
  The Raman selection rules of the (ZnSe, BeSe) mixed phonon polariton created
by alloying in the three mode (1ZnSe, 2BeSe) ZnBeSe system, whose dramatic S
like dispersion covers the large frequency gap between the ZnSe and BeSe
spectral ranges, is studied in its wave vector dependence by near forward
scattering. Both the collapse regime away from the Brillouin zone centre and
the reinforcement regime near the Brillouin zone centre are addressed, using
appropriate laser lines and Be contents. We find that in both regimes the
considered phonon polariton, in fact a transverse mode with mixed mechanical
and electrical character, obeys the same nominal Raman selection rules as its
purely mechanical variant commonly observed in the backscattering geometry.
Besides, marked differences in the phonon polariton Raman lineshapes in the two
regimes give a hint about how the phonon polariton electrical field E develops
while descending the S like dispersion towards the Brillouin zone centre. In
the reinforcement regime E is large, leading to intramode on top of intermode
transfers of oscillator strength mediated by E between the two BeSe modes, that
both exhibit a fine structure on account of the alloy disorder. In contrast, in
the collapse regime E remains weak, as testified by the absence of intramode
transfer. The discussion is supported by contour modeling of the multi phonon
polariton Raman lineshapes in their wave vector dependence within the linear
dielectric approach.


title:
Removing the stabilization parameter in fitted and unfitted symmetric
  Nitsche formulations

abstract:
  In many situations with finite element discretizations it is desirable or
necessary to impose boundary or interface conditions not as essential
conditions -- i.e. through the finite element space -- but through the
variational formulation. One popular way to do this is Nitsche's method. In
Nitsche's method a stabilization parameter $\lambda$ has to be chosen
"sufficiently large" to provide a stable formulation. Sometimes discretizations
based on a Nitsche formulation are criticized because of the need to manually
choose this parameter. While in the discontinuous Galerkin community variants
of the Nitsche method -- known as "interior penalty" method in the DG context
-- are known which do not require such a manually chosen stabilization
parameter, this has not been considered for Nitsche formulations in other
contexts. We introduce and analyse such a parameter-free variant for two
applications of Nitsche's method. First, the classical Nitsche formulation for
the imposition of boundary conditions with fitted meshes and secondly, an
unfitted finite element discretizations for the imposition of interface
conditions is considered. The introduced variants of corresponding Nitsche
formulations do not change the sparsity pattern and can easily be implemented
into existing finite element codes. The benefit of the new formulations is the
removal of the Nitsche stabilization parameter $\lambda$ while keeping the
stability properties of the original formulations for a "sufficiently large"
stabilization parameter $\lambda$.


title: Okounkov bodies and Zariski decompositions on surfaces

abstract:
  The purpose of this paper is to investigate the close relation between
Okounkov bodies and Zariski decompositions of pseudoeffective divisors on
smooth projective surfaces. Firstly, we completely determine the limiting
Okounkov bodies on such surfaces, and give applications to Nakayama constants
and Seshadri constants. Secondly, we study how the shapes of Okounkov bodies
change as we vary the divisors in the big cone.


title: Porting Code Across Simple Mobile Robots

abstract:
  The StarL programming framework aims to simplify development of distributed
robotic applications by providing easy-to-use language constructs for
communication and control. It has been used to develop applications such as
formation control, distributed tracking, and collaborative search. In this
paper, we present a complete redesign of the StarL language and its runtime
system which enables us to achieve portability of robot programs across
platforms. Thus, the same application program, say, for distributed tracking,
can now be compiled and deployed on multiple, heterogeneous robotic platforms.
Towards portability, this we first define the semantics of StarL programs in a
way that is largely platform independent, except for a few key
platform-dependent parameters that capture the worst-case execution and sensing
delays and resolution of sensors. Next, we present a design of the StarL
runtime system, including a robot controller, that meets the above semantics.
The controller consists of a platform-independent path planner implemented
using RRTs and a platform-dependent way-point tracker that is implemented using
the control commands available for the platform. We demonstrate portability of
StarL applications using simulation results for two different robotic
platforms, and several applications.


title: Cotunneling into a Kondo lattice with odd hybridization

abstract:
  Cotunneling into Kondo systems, where an electron enters a $f$-electron
material via a cotunneling process through the local-moment orbital, has been
proposed to explain the characteristic lineshapes observed in
scanning-tunneling-spectroscopy (STS) experiments. Here we extend the theory of
electron cotunneling to Kondo-lattice systems where the bulk hybridization
between conduction and $f$ electrons is odd under inversion, being particularly
relevant to Kondo insulators. Compared to the case of even hybridization, we
show that the interference between normal tunneling and cotunneling processes
is fundamentally altered: it is entirely absent for layered, i.e.,
quasi-two-dimensional materials, while its energy dependence is strongly
modified for three-dimensional materials. We discuss implications for STS
experiments.


title: Incompatibility boundaries for properties of community partitions

abstract:
  We prove the incompatibility of certain desirable properties of community
partition quality functions. Our results generalize the impossibility result of
[Kleinberg 2003] by considering sets of weaker properties. In particular, we
use an alternative notion to solve the central issue of the consistency
property. (The latter means that modifying the graph in a way consistent with a
partition should not have counterintuitive effects). Our results clearly show
that community partition methods should not be expected to perfectly satisfy
all ideally desired properties.
  We then proceed to show that this incompatibility no longer holds when
slightly relaxed versions of the properties are considered, and we provide in
fact examples of simple quality functions satisfying these relaxed properties.
An experimental study of these quality functions shows a behavior comparable to
established methods in some situations, but more debatable results in others.
This suggests that defining a notion of good partition in communities probably
requires imposing additional properties.


title: PLATO: Policy Learning using Adaptive Trajectory Optimization

abstract:
  Policy search can in principle acquire complex strategies for control of
robots and other autonomous systems. When the policy is trained to process raw
sensory inputs, such as images and depth maps, it can also acquire a strategy
that combines perception and control. However, effectively processing such
complex inputs requires an expressive policy class, such as a large neural
network. These high-dimensional policies are difficult to train, especially
when learning to control safety-critical systems. We propose PLATO, an
algorithm that trains complex control policies with supervised learning, using
model-predictive control (MPC) to generate the supervision, hence never in need
of running a partially trained and potentially unsafe policy. PLATO uses an
adaptive training method to modify the behavior of MPC to gradually match the
learned policy in order to generate training samples at states that are likely
to be visited by the learned policy. PLATO also maintains the MPC cost as an
objective to avoid highly undesirable actions that would result from strictly
following the learned policy before it has been fully trained. We prove that
this type of adaptive MPC expert produces supervision that leads to good
long-horizon performance of the resulting policy. We also empirically
demonstrate that MPC can still avoid dangerous on-policy actions in unexpected
situations during training. Our empirical results on a set of challenging
simulated aerial vehicle tasks demonstrate that, compared to prior methods,
PLATO learns faster, experiences substantially fewer catastrophic failures
(crashes) during training, and often converges to a better policy.


title: An upper bound to multiscale roughness-induced adhesion enhancement

abstract:
  Recently Guduru and coworkers have demonstrated with neat theory and
experiments that both increase of strength and of toughness are possible in the
contact of a rigid sphere with concentric single scale of waviness, against a
very soft material. The present note tries to answer the question of a
multiscale enhancement of adhesion, considering a Weierstrass series to
represent the multiscale roughness, and analytical results only are used. It is
concluded that the enhancement is bounded for low fractal dimensions but it can
happen, and possibly to very high values, whereas it is even unbounded for high
fractal dimensions, but it is also much less likely to occur, because of
separated contacts.


title:
Critical stress statistics and a fold catastrophe in intermittent
  crystal plasticity

abstract:
  The statistics and origin of the first discrete plastic event in a one
dislocation dynamics simulation are studied. This is done via a linear
stability analysis of the evolving dislocation configuration up to the onset of
irreversible plasticity. It is found, via a fold catastrophe, the dislocation
configuration prior to loading directly determines the stress at which the
plastic event occurs and that between one and two trigger dislocations are
involved. The resulting irreversible plastic strain arising from the
instability is found to be highly correlated with these triggering
dislocations.


title:
The ISLANDS project I: Andromeda XVI, An Extremely Low Mass Galaxy not
  Quenched by Reionization

abstract:
  Based on data aquired in 13 orbits of HST time, we present a detailed
evolutionary history of the M31 dSph satellite Andromeda XVI, including its
life-time star formation history, the spatial distribution of its stellar
populations, and the properties of its variable stars. And XVI is characterized
by prolonged star formation activity from the oldest epochs until star
formation was quenched ~6 Gyr ago, and, notably, only half of the mass in stars
of And XVI was in place 10 Gyr ago. And XVI appears to be a low mass galaxy for
which the early quenching by either reionization or starburst feedback seems
highly unlikely, and thus, is most likely due to an environmental effect (e.g.,
an interaction), possibly connected to a late infall in the densest regions of
the Local Group. Studying the star formation history as a function of
galactocentric radius, we detect a mild gradient in the star formation history:
the star formation activity between 6 and 8 Gyr ago is significantly stronger
in the central regions than in the external regions, although the quenching age
appears to be the same, within 1 Gyr. We also report the discovery of 9 RR
Lyrae stars, 8 of which belong to And XVI. The RR Lyrae stars allow a new
estimate of the distance, (m-M)0= 23.72+/-0.09 mag, which is marginally larger
than previous estimates based on the tip of the red giant branch.


title:
Energy filtering enhancement of thermoelectric performance of
  nanocrystalline Cr-Si composites

abstract:
  We report on thermoelectric properties of nanocrystalline Cr$_{\rm
1-x}$Si$_{\rm x}$ composite films. As-deposited amorphous films were
transformed into a nanocrystalline state with average grain size of 10--20~nm
by annealing during in-situ thermopower and electrical resistivity
measurements. The partially crystallized films, i.e. the films consisting of
crystalline grains dispersed in the amorphous matrix, are a new type of the
heterogeneous material where the nanocrystalline phase plays the role of
scattering centers giving rise to a large contribution to the thermopower. We
show that the thermopower enhancement is related to the energy dependent
scattering (energy filtering) of the charge carriers on the nanograin
interfaces.


title: Temporal evolution of resonant transmission under telegraph noise

abstract:
  The environment of a quantum dot, which is connected to two leads, is modeled
by telegraph noise, i.e. random Markovian jumps of the (spinless) electron
energy on the dot between two levels. The temporal evolutions of the charge on
the dot and of the currents in the leads are studied using a recently developed
single-particle basis approach, which is particularly convenient for the
averaging over the histories of the noise. In the steady state limit we recover
the Landauer formula. At a very fast jump rate between the two levels, the
noise does not affect the transport. As the jump rate decreases, the effective
average transmission crosses over from the transmission through a single
(average) level to an incoherent sum of the transmissions through the two
levels. 13 pages, 6 figuresThe transient temporal evolution towards the steady
state is dominated by the displacement current at short times, and by the
Landauer current at long times. It contains oscillating terms, which decay to
zero faster than for the case without noise. When the average chemical
potential on the leads equals the dot's "original" energy, without the noise,
the oscillations disappear completely and the transient evolution becomes
independent of the noise.


title:
Maximal surfaces in Anti-de Sitter space, width of convex hulls and
  quasiconformal extensions of quasisymmetric homeomorphisms

abstract:
  We give upper bounds on the principal curvatures of a maximal surface of
nonpositive curvature in three-dimensional Anti-de Sitter space, which only
depend on the width of the convex hull of the surface. Moreover, given a
quasisymmetric homeomorphism $\phi$, we study the relation between the width of
the convex hull of the graph of $\phi$, as a curve in the boundary of infinity
of Anti-de Sitter space, and the cross-ratio norm of $\phi$.
  As an application, we prove that if $\phi$ is a quasisymmetric homeomorphism
of $\mathbb{R}\mathrm{P}^1$ with cross-ratio norm $||\phi||$, then $\ln K\leq
C||\phi||$, where $K$ is the maximal dilatation of the minimal Lagrangian
extension of $\phi$ to the hyperbolic plane.


title:
Reply to Comment on "New formulas for the $(-2)$ moment of the
  photo-absorption cross section, $\sigma_{_{-2}}$"

abstract:
  This is a Reply to a Comment on my paper: New formulas for the (-2) moment of
the photo-absorption cross section, sigma-2.


title:
Spectroscopic investigation of phase transitions in 1-nonanol and
  1-decanol

abstract:
  FTIR spectra of monohydric alcohols 1-nonanol (C9H19OH) and 1-decanol
(C10H21OH) were registered in the spectral region from 500 cm-1 to 4000 cm-1 at
temperatures from -50 to + 25 {\deg}C for 1-nonanol and +100 {\deg}C for
1-decanol. Temperature-induced spectra changes were compared for these two
alcohols. The authors link the observed changes with the transformations of
cluster structure occurring during phase transitions.


title:
Norm-variation of ergodic averages with respect to two commuting
  transformations

abstract:
  We study double ergodic averages with respect to two general commuting
transformations and establish a sharp quantitative result on their convergence
in the norm. We approach the problem via real harmonic analysis, using recently
developed methods for bounding multilinear singular integrals with certain
entangled structure. A byproduct of our proof is a bound for a two-dimensional
bilinear square function related to the so-called triangular Hilbert transform.


title:
ALE-SUPG finite element method for convection-diffusion problems in
  time-dependent domains: Non-conservative form

abstract:
  Stability estimates for Streamline Upwind Petrov-Galerkin (SUPG) finite
element method with different time integration schemes for the solution of a
scalar transient convection-diffusion-reaction equation in a time-dependent
domain are derived. The deformation of the domain is handled with the arbitrary
Lagrangian-Eulerian (ALE) approach. In particular, the non-conservative form of
the ALE scheme is considered. The implicit Euler, the Crank-Nicolson, and the
backward-difference~(BDF-2) methods are used for temporal discretization. It is
shown that the stability of the semi-discrete (continuous in time) ALE-SUPG
equation is independent of the mesh velocity, whereas the stability of the
fully discrete problem is only conditionally stable. The theoretical
considerations are illustrated by a numerical example. Further, the dependence
of numerical solution on the choice of stabilization parameter $\delta_k$ is
also presented.


title: Big Data Processing in Complex Hierarchical Network Systems

abstract:
  This article covers the problem of processing of Big Data that describe
process of complex networks and network systems operation. It also introduces
the notion of hierarchical network systems combination into associations and
conglomerates alongside with complex networks combination into multiplexes. The
analysis is provided for methods of global network structures study depending
on the purpose of the research. Also the main types of information flows in
complex hierarchical network systems being the basic components of associations
and conglomerates are covered. Approaches are proposed for creation of
efficient computing environments, distributed computations organization and
information processing methods parallelization at different levels of system
hierarchy.


title: Beta generated Kumaraswamy-G and other new families of distributions

abstract:
  A new generalization of the family of Kumaraswamy-G (Cordeiro and de Castro,
2011) distribution that includes three recently proposed families namely the
Garhy generated family (Elgarhy et al., 2016), Beta-Dagum and
Beta-Singh-Maddala distribution (Domma and Condino, 2016) is proposed by
constructing beta generated Kumaraswamy-G distribution. Useful expansions of
the pdf and the cdf of the proposed family is derived and seen as infinite
mixtures of the Kumaraswamy-G distribution. Order statistics, Probability
weighted moments, moment generating function, R\'enyi entropies, quantile power
series, random sample generation, asymptotes and shapes are also investigated.
Two methods of parameter estimation are presented. Suitability of the proposed
model in comparisons to its sub models is carried out considering two real life
data sets. Finally, some new classes of beta generated families are proposed
for future investigations.


title:
Spectral shift and dephasing of electromagnetically induced transparency
  in an interacting Rydberg gas

abstract:
  We perform spectroscopic measurements of electromagnetically induced
transparency (EIT) in a strongly interacting Rydberg gas, and observe a
significant spectral shift of the transparency from the single-atom EIT
resonance as well as a spectral dephasing of the same order. We characterize
the shift and dephasing as a function of atomic density, probe Rabi frequency,
and principal quantum number of Rydberg states, and demonstrate that the
observed spectral shift and dephasing are reduced if the size of a Gaussian
atomic cloud is increased. We simulate our experiment with a semi-analytical
model, which gives results in good agreement with our experimental data.


title: Semi-Automated Design Space Exploration for Formal Modelling

abstract:
  Refinement based formal methods allow the modelling of systems through
incremental steps via abstraction. Discovering the right levels of abstraction,
formulating correct and meaningful invariants, and analysing faulty models are
some of the challenges faced when using this technique. Here, we propose Design
Space Exploration, an approach that aims to assist a designer by automatically
providing high-level modelling guidance in real-time. More specifically,
through the combination of common patterns of modelling with techniques from
automated theory formation and automated reasoning, different design
alternatives are explored and suitable models that deal with faults are
proposed.


title: Strong field gravitational lensing by a charged Galileon black hole

abstract:
  Strong field gravitational lensings are dramatically disparate from those in
the weak field by representing relativistic images due to light winds one to
infinity loops around a lens before escaping. We study such a lensing caused by
a charged Galileon black hole, which is expected to have possibility to evade
no-hair theorem. We calculate the angular separations and time delays between
different relativistic images of the charged Galileon black hole. All these
observables can potentially be used to discriminate a charged Galileon black
hole from others. We estimate the magnitudes of these observables for the
closest supermassive black hole Sgr A*. The strong field lensing observables of
the charged Galileon black hole can be close to those of a tidal
Reissner-Nordstr\"{o}m black hole or those of a Reissner-Nordstr\"{o}m black
hole. It will be helpful to distinguish these black holes if we can separate
the outermost relativistic images and determine their angular separation,
brightness difference and time delay, although it requires techniques beyond
the current limit.


title:
Investigating the alpha-clustering on the surface of $^{120}$Sn via
  ($p$,$p\alpha$) reaction and the validity of the factorization approximation

abstract:
  The $^{120}$Sn($p$,$p\alpha$)$^{116}$Cd reaction at 392 MeV is investigated
with the distorted wave impulse approximation (DWIA) framework. We show that
this reaction is very peripheral mainly because of the strong absorption of
$\alpha$ by the reaction residue $^{116}$Cd, and the $\alpha$-clustering on the
nuclear surface can be probed clearly. We investigate also the validity of the
so-called factorization approximation that has frequently been used so far. It
is shown that the kinematics of $\alpha$ in the nuclear interior region is
significantly affected by the distortion of $^{116}$Cd, but it has no effect on
the reaction observables because of the strong absorption in that region.


title:
Quantum simulation of traversable wormhole spacetimes in a dc-SQUID
  array

abstract:
  We present an analog quantum simulator of spacetimes containing traversable
wormholes. A suitable spatial dependence in the external bias of a dc-SQUID
array mimics the propagation of light in a 1D wormhole background. The
impedance of the array places severe limitations on the type of spacetime that
we are able to implement. However, we find that wormhole throat radius in the
sub-mm range are achievable. We show how to modify this spacetime in order to
allow the existence of closed timelike curves. The quantum fluctuations of the
phase associated to the finite array impedance might be seen as an analogue of
Hawking's chronology protection mechanism.