title: Generating Natural Language Inference Chains

abstract:
  The ability to reason with natural language is a fundamental prerequisite for
many NLP tasks such as information extraction, machine translation and question
answering. To quantify this ability, systems are commonly tested whether they
can recognize textual entailment, i.e., whether one sentence can be inferred
from another one. However, in most NLP applications only single source
sentences instead of sentence pairs are available. Hence, we propose a new task
that measures how well a model can generate an entailed sentence from a source
sentence. We take entailment-pairs of the Stanford Natural Language Inference
corpus and train an LSTM with attention. On a manually annotated test set we
found that 82% of generated sentences are correct, an improvement of 10.3% over
an LSTM baseline. A qualitative analysis shows that this model is not only
capable of shortening input sentences, but also inferring new statements via
paraphrasing and phrase entailment. We then apply this model recursively to
input-output pairs, thereby generating natural language inference chains that
can be used to automatically construct an entailment graph from source
sentences. Finally, by swapping source and target sentences we can also train a
model that given an input sentence invents additional information to generate a
new sentence.


title:
Electrical characterization of chemical and dielectric passivation of
  InAs nanowires

abstract:
  The native oxide at the surface of III-V nanowires, such as InAs, can be a
major source of charge noise and scattering in nanowire-based electronics,
particularly for quantum devices operated at low temperatures. Surface
passivation provides a means to remove the native oxide and prevent its
regrowth. Here, we study the effects of surface passivation and conformal
dielectric deposition by measuring electrical conductance through nanowire
field effect transistors treated with a variety of surface preparations. By
extracting field effect mobility, subthreshold swing, threshold shift with
temperature, and the gate hysteresis for each device, we infer the relative
effects of the different treatments on the factors influencing transport. It is
found that a combination of chemical passivation followed by deposition of an
aluminum oxide dielectric shell yields the best results compared to the other
treatments, and comparable to untreated nanowires. Finally, it is shown that an
entrenched, top-gated device using an optimally treated nanowire can
successfully form a stable double quantum dot at low temperatures. The device
has excellent electrostatic tunability owing to the conformal dielectric layer
and the combination of local top gates and a global back gate.


title:
A nanostructured surface increases friction exponentially at the
  solid-gas interface

abstract:
  According to Stokes' law, a moving solid surface experiences dissipation that
is linearly related to its velocity and the viscosity of the medium. This
linear dependence on viscosity forms the basis for many characterization
techniques for liquids. Unlike viscosities of different liquids, viscosities of
gases vary only in a narrow range which limits their use as an effective
characterization parameter using moving structures. Here we report experimental
results of dissipation showing exponential dependence on viscosity for
oscillating surfaces modified with nanostructures. The surface nanostructures
alter solid-gas interplay greatly, amplifying the dissipation response
exponentially for even minute variations in viscosity. Nanostructured resonator
thus allows discrimination of otherwise narrow range of gaseous viscosity
making it an ideal detection parameter for analysis. We attribute the observed
exponential enhancement to the stochastic nature of interactions of many
coupled nanostructures with the gas media.


title:
Rapid estimation of drifting parameters in continuously measured quantum
  systems

abstract:
  We investigate the determination of a Hamiltonian parameter in a quantum
system undergoing continuous measurement. We demonstrate a computationally
rapid yet statistically optimal method to estimate an unknown and possibly
time-dependent parameter, where we maximize the likelihood of the observed
stochastic readout. By dealing directly with the raw measurement record rather
than the quantum state trajectories, the estimation can be performed while the
data is being acquired, permitting continuous tracking of the parameter during
slow drifts in real time. Furthermore, we incorporate realistic nonidealities,
such as decoherence processes and measurement inefficiency. As an example, we
focus on estimating the value of the Rabi frequency of a continuously measured
qubit, and compare maximum likelihood estimation to a simpler fast Fourier
transform. Using this example, we discuss how the quality of the estimation
depends on both the strength and duration of the measurement; we also discuss
the trade-off between the accuracy of the estimate and the sensitivity to drift
as the estimation duration is varied.


title:
Phase transition and thermodynamic stability in extended phase space and
  charged Ho\v{r}ava-Lifshitz black holes

abstract:
  For charged black holes in Horava-Lifshitz gravity, a second order phase
transition takes place in extended phase space where the cosmological constant
is taken as thermodynamic pressure. We relate the second order nature of phase
transition to the fact that the phase transition occurs at a sharp temperature
and not over a temperature interval. Once we know the continuity of the first
derivatives of the Gibbs free energy, we show that all the Ehrenfest equations
are readily satisfied. We study the effect of the perturbation of the
cosmological constant as well as the perturbation of the electric charge on
thermodynamic stability of Horava-Lifshitz black hole. We also use
thermodynamic geometry to study phase transition in extended phase space. We
investigate the behavior of scalar curvature of Weinhold, Ruppeiner, and
Quevedo metric in extended phase space of charged Horava-Lifshitz black holes.
It is checked if these curvatures could reproduce the result of specific heat
for the phase transition.


title: Weak associativity and deformation quantization

abstract:
  Non-commutativity and non-associativity are quite natural in string theory.
For open strings it appear due to the presence of non-vanishing background
two-form in the world volume of Dirichlet brane, while in closed string theory
the flux compactifications with non-vanishing three-form also lead to
non-geometric backgrounds. In this paper, working in the framework of
deformation quantization, we study the violation of associativity imposing the
condition that the associator of three elements should vanish whenever each two
of them are equal. The corresponding star products are called alternative and
satisfy an important for physical applications properties like the Moufang
identities, alternative identities, Artin's theorem, etc. The condition of
alternativity is invariant under the gauge transformations, just like it
happens in the associative case. The price to pay is the restriction on the
non-associative algebra which can be represented by the alternative star
product, it should satisfy the Malcev identity. The example of nontrivial
Malcev algebra is the algebra of imaginary octonions. For this case we
construct an explicit expression of the non-associative and alternative star
product. We also discuss the quantization of Malcev-Poisson algebras of general
form, study its properties and provide the lower order expression for the
alternative star product. To conclude we define the integration on the algebra
of the alternative star products and show that the integrated associator
vanishes.


title: Constraining the surface properties of effective Skyrme interactions

abstract:
  The purpose of this study is threefold: first, to identify a scheme for the
determination of the surface energy coefficient a_surf that offers the best
compromise between robustness, precision, and numerical efficiency; second, to
analyze the correlation between values for a_surf and the characteristic
energies of the fission barrier of Pu240; and third, to lay out a procedure how
the deformation properties of the Skyrme energy density functional (EDF) can be
constrained during the parameter fit.
  There are several frequently used possibilities to define and calculate the
surface energy coefficient a_surf of effective interactions. The most direct
access is provided by the model system of semi-infinite nuclear matter, but
a_surf can also be extracted from the systematics of binding energies of finite
nuclei. Calculations can be carried out either self-consistently (HF), which
incorporates quantal shell effects, or in one of the semi-classical Extended
Thomas-Fermi (ETF) or Modified Thomas-Fermi (MTF) approximations.
  The surface energy coefficient of 76 parameterizations of the Skyrme EDF have
been calculated. Values obtained with the HF, ETF and MTF methods are not
identical, but differ by fairly constant systematic offsets.
  Despite having some drawbacks compared to the other methods studied here, the
MTF approach provides sufficiently precise values for a_surf such that it can
be used as a very robust constraint on surface properties during a parameter
fit at negligible additional cost. Through the construction of a series of
eight parameterizations SLy5s1-SLy5s8 of the standard Skyrme EDF with
systematically varied a_surf value it is shown how to arrive at a fit with
realistic deformation properties.
  [Note: The abstract has been abbreviated because of length restrictions
imposed by the arXiv. See the paper for the full abstract.]


title:
Scale bridging description of coherent phase equilibria in the presence
  of surfaces and interfaces

abstract:
  We investigate phase separation including elastic coherency effects in the
bulk and at surfaces and find a reduction of the solubility limit in the
presence of free surfaces. This mechanism favours phase separation near free
surfaces even in the absence of external stresses. We apply the theory to
hydride formation in nickel, iron and niobium and obtain a reduction of the
solubility limit by up to two orders of magnitude at room temperature in the
presence of free surfaces. These effects are concisely expressed through a
solubility modification factor, which transparently expresses the long-ranged
elastic effects in a terminology accessible e.g. to ab initio calculations.


title: Distance Metric Ensemble Learning and the Andrews-Curtis Conjecture

abstract:
  Motivated by the search for a counterexample to the Poincar\'e conjecture in
three and four dimensions, the Andrews-Curtis conjecture was proposed in 1965.
It is now generally suspected that the Andrews-Curtis conjecture is false, but
small potential counterexamples are not so numerous, and previous work has
attempted to eliminate some via combinatorial search. Progress has however been
limited, with the most successful approach (breadth-first-search using
secondary storage) being neither scalable nor heuristically-informed. A
previous empirical analysis of problem structure examined several heuristic
measures of search progress and determined that none of them provided any
useful guidance for search. In this article, we induce new quality measures
directly from the problem structure and combine them to produce a more
effective search driver via ensemble machine learning. By this means, we
eliminate 19 potential counterexamples, the status of which had been unknown
for some years.


title: Superconducting $\pi$-ring metamaterials

abstract:
  We develop the concept of fractal metamaterials which consist of arrays of
nano and micron sized rings containing Josephson junctions which play the role
of "atoms" in such artificial materials. We show that if some of the junctions
have $\pi$-shifts in the Josephson phases that the "atoms" become magnetic and
their arrays can have tuned positive or negative permeabilty. Each individual
"$\pi$-ring" - the Josephson ring with one $\pi$-junction - can be in one of
two energetically degenerate magnetic states in which the supercurrent flows in
the clockwise or counter-clockwise direction. This results in magnetic moments
that point downwards or upwards, respectively. The value of the total
magnetization of such a metamaterial may display fractal features. We describe
the magnetic properties of such superconducting metamaterials, including the
magnetic field distribution in them (i.e. in the network that is made up of
these rings). We also describe the way that the magnetic flux penetrates into
the Josephson network and how it is strongly dependent on the geometry of the
system.


title: Solutions of the hexagon equation for abelian anyons

abstract:
  We address the problem of determining the obstruction to the existence of
solutions of the hexagon equation for abelian fusion rules and the
classification of prime abelian anyons.


title:
Predictions of canonical wall bounded turbulent flows via a modified
  $k-\omega$ equation

abstract:
  A major challenge in computation of engineering flows is to derive and
improve turbulence models built on turbulence physics. Here, we present a
physics-based modified $k-\omega$ equation for canonical wall bounded turbulent
flows (boundary layer, channel and pipe), predicting both mean velocity profile
(MVP) and streamwise mean kinetic energy profile (SMKP) with high accuracy over
a wide range of Reynolds number ($Re$). The result builds on a multi-layer
quantification of wall flows, which allows a significant modification of the
$k-\omega$ equation. Three innovations are introduced: First, an adjustment of
the Karman constant to 0.45 is set for the overlap region with a logarithmic
MVP. Second, a wake parameter models the turbulent transport near the
centerline. Third, an anomalous dissipation factor represents the effect of a
meso layer in the overlap region. Then, a highly accurate (above 99\%)
prediction of MVPs is obtained in Princeton pipes, improving the original model
prediction by up to 10\%. Moreover, the entire SMKP, including the newly
observed outer peak, is predicted. With a slight change of the wake parameter,
the model also yields accurate predictions for channels and boundary layers.


title:
Online Power Control Optimization for Wireless Transmission with Energy
  Harvesting and Storage

abstract:
  We consider wireless transmission over fading channel powered by energy
harvesting and storage devices. Assuming a finite battery storage capacity, we
design an online power control strategy aiming at maximizing the long-term
time-averaged transmission rate under battery operational constraints for
energy harvesting. We first formulate the stochastic optimization problem, and
then develop techniques to transform this problem and employ techniques from
Lyapunov optimization to design the online power control solution. In
particular, we propose an approach to handle unbounded channel fade which
cannot by directly dealt with by Lyapunov framework. Our proposed algorithm
determines the transmission power based only on the current energy state of the
battery and channel fade conditions,without requiring any knowledge of the
statistics of energy arrivals and fading channels. Our online power control
solution is a three-stage closed-form solution depending on the battery energy
level. It not only provides strategic energy conservation through the battery
energy control, but also reveals an opportunistic transmission style based on
fading condition, both of which improve the long-term time-averaged
transmission rate. We further characterize the performance bound of our
proposed algorithm to the optimal solution with a general fading distribution.
Simulation results demonstrate a significant performance gain of our proposed
online algorithm over alternative online approaches.


title: MECO In An Exponential Metric

abstract:
  Magnetic Eternally Collapsing Objects (MECO) have been proposed as the
central engines of galactic black hole candidates (GBHC) and supermassive
active galactic nuclei (AGN). Previous work has shown that their luminosities
and spectral and timing characteristics are in good agreement with
observations. These features and the formation of jets are generated primarily
by the interactions of accretion disks with an intrinsically magnetic central
MECO. The interaction of accretion disks with the anchored magnetic fields of
the central objects permits a unified description of properties for GBHC, AGN,
neutron stars in low mass x-ray binaries and dwarf novae systems. The
previously published MECO models have been based on a quasistatic Schwarzschild
metric of General Relativity; however, the only essential feature of this
metric is its ability to produce extreme gravitational redshifts. For reasons
discussed in this article, an alternative development based on a quasistatic
exponential metric is considered here.


title:
Alpha invariant for general polarization of del Pezzo surfaces of degree
  1

abstract:
  For an arbitrary ample divisor A in smooth del Pezzo surface S of degree 1,
we verify the condition of the polarization (S,A) to be K-stable and it is a
simple numerical condition.


title: One-dimensional Cutting Stock Problem with Divisible Items

abstract:
  This paper considers the one-dimensional cutting stock problem with divisible
items, which is a new problem in the cutting stock literature. The problem
exists in steel industries. In the new problem, each item can be divided into
smaller pieces, then they can be recombined again by welding. The objective is
to minimize both the trim loss and the number of the welds. We present a
mathematical model and a dynamic programming based heuristic for the problem.
Furthermore, a software, which is based on the proposed heuristic algorithm, is
developed to use in MKA company, and its performance is analyzed by solving
real-life problems in the steel industry. The computational experiments show
the efficiency of the proposed algorithm.


title: Lagrangian Relations and Linear Point Billiards

abstract:
  Motivated by the high-energy limit of the $N$-body problem we construct
non-deterministic billiard process. The billiard table is the complement of a
finite collection of linear subspaces within a Euclidean vector space. A
trajectory is a constant speed polygonal curve with vertices on the subspaces
and change of direction upon hitting a subspace governed by `conservation of
momentum' (mirror reflection). The itinerary of a trajectory is the list of
subspaces it hits, in order. Two basic questions are: (A) Are itineraries
finite? (B) What is the structure of the space of all trajectories having a
fixed itinerary? In a beautiful series of papers Burago-Ferleger-Kononenko
[BFK] answered (A) affirmatively by using non-smooth metric geometry ideas and
the notion of a Hadamard space. We answer (B) by proving that this space of
trajectories is diffeomorphic to a Lagrangian relation on the space of lines in
the Euclidean space. Our methods combine those of BFK with the notion of a
generating family for a Lagrangian relation.


title:
Bounds for approximating lower envelopes with polynomials of degree at
  most $d$

abstract:
  Given a lower envelope in the form of an arbitrary sequence $u$, let $LSP(u,
d)$ denote the maximum length of any subsequence of $u$ that can be realized as
the lower envelope of a set of polynomials of degree at most $d$. Let $sp(m,
d)$ denote the minimum value of $LSP(u, d)$ over all sequences $u$ of length
$m$. We derive bounds on $sp(m, d)$ using another extremal function for
sequences.
  A sequence $u$ is called $v$-free if no subsequence of $u$ is isomorphic to
$v$. Given sequences $u$ and v, let $LSS(u, v)$ denote the maximum length of a
$v$-free subsequence of $u$. Let $ss(m, v)$ denote the minimum of $LSS(u, v)$
over all sequences $u$ of length $m$. By bounding $ss(m, v)$ for alternating
sequences $v$, we prove quasilinear bounds in $m^{1/2}$ on $sp(m,d)$ for all $d
> 0$.


title:
Estimate of the reproduction number of the 2015 Zika virus outbreak in
  Barranquilla, Colombia, and estimation of the relative role of sexual
  transmission

abstract:
  Background: In 2015, the Zika arbovirus (ZIKV) began circulating in the
Americas, rapidly expanding its global geographic range in explosive outbreaks.
Unusual among mosquito-borne diseases, ZIKV has been shown to also be sexually
transmitted, although sustained autochthonous transmission due to sexual
transmission alone has not been observed, indicating the reproduction number
(R0) for sexual transmission alone is less than 1. Critical to the assessment
of outbreak risk, estimation of the potential attack rates, and assessment of
control measures, are estimates of the basic reproduction number, R0. Methods:
We estimated the R0 of the 2015 ZIKV outbreak in Barranquilla, Colombia,
through an analysis of the exponential rise in clinically identified ZIKV cases
(n = 359 to the end of November, 2015). Findings: The rate of exponential rise
in cases was rho=0.076 days-1, with 95 percent CI [0.066,0.087] days-1. We used
a vector-borne disease model with additional direct transmission to estimate
the R0; assuming the R0 of sexual transmission alone is less than 1, we
estimated the total R0 = 3.8 [2.4,5.6], and that the fraction of cases due to
sexual transmission was 0.23 [0.01,0.47] with 95 percent confidence.
Interpretation: This is among the first estimates of R0 for a ZIKV outbreak in
the Americas, and also among the first quantifications of the relative impact
of sexual transmission.


title: Alternating strings and clusters in suspensions of charged colloids

abstract:
  We report the formation of alternating strings and clusters in a binary
suspension of repulsive charged colloids with double layers larger than the
particle size. Within a binary cell model we include many-body and
charge-regulation effects under the assumption of a constant surface potential,
and consider their repercussions on the two-particle interaction potential. We
find that the formation of induced dipoles close to a charge-reversed state may
explain the formation of these structures. Finally, we will touch upon the
formation of dumbbells and small clusters in a one-component system, where the
effective electrostatic interaction is always repulsive.


title: The exact information-based complexity of smooth convex minimization

abstract:
  We obtain a new lower bound on the information-based complexity of
first-order minimization of smooth and convex functions. We show that the bound
matches the worst-case performance of the recently introduced Optimized
Gradient Method, thereby establishing that the bound is tight and can be
realized by an efficient algorithm. The proof is based on a novel construction
technique of smooth and convex functions.


title:
Using Multimedia Presentations to Improve Digital Forensic
  Understanding: A Pilot Study

abstract:
  Improving employees' understanding of digital forensic technical terms and
concepts within an organisation is likely to increase the potential of
successful collaboration during a cyber security incident (e.g. data breach)
investigation within that organisation. In this paper, we seek to determine
whether multimedia presentations, in this case videos, are an effective tool in
improving a learner's technical understanding of digital forensic terms and
concepts. Using the cognitive theory of multimedia learning as the underlying
theoretical lens, we surveyed nine participants from the financial sector who
have cyber security-related responsibilities. With the exception of one
participant, the study found that the use of multimedia presentations can
improve participants' understanding of technical digital forensic terms and
concepts. Potential future research questions are also identified.


title: Multimodal Game Bot Detection using User Behavioral Characteristics

abstract:
  As the online service industry has continued to grow, illegal activities in
the online world have drastically increased and become more diverse. Most
illegal activities occur continuously because cyber assets, such as game items
and cyber money in online games, can be monetized into real currency. The aim
of this study is to detect game bots in a Massively Multiplayer Online Role
Playing Game (MMORPG). We observed the behavioral characteristics of game bots
and found that they execute repetitive tasks associated with gold farming and
real money trading. We propose a game bot detection methodology based on user
behavioral characteristics. The methodology of this paper was applied to real
data provided by a major MMORPG company. Detection accuracy rate increased to
96.06% on the banned account list.


title:
Using Collaborative Visual Analytics for Innovative Industry-inspired
  Learning Activities

abstract:
  Inspired by the leading industry practices, this paper describes an
innovative learning activity that combines data visualization and collaboration
structured around sharing, co-creation and negotiation of
departmental/disciplinary insights across data silos, using both internal and
external data. This activity was designed within a much larger project aiming
to translate practitioner stories and experiences in using visual analytics
into educational scenarios and innovative industry-informed learning activities
for students. In addition to giving students access to state-of-the-art tools
for visualization (SAS-VA) and collaboration (Yammer), an even more important
educational objective is to expose students to current industry practices with
individual data-driven disciplinary insights no longer considered to sufficient
when dealing with complex multi-disciplinary challenges. Starting from a
data-informed business scenario, the paper describes the main steps of our
innovative data visualisation and collaboration activity, discusses possible
alternative software platforms and offers some ideas for the future work.


title:
Exploring Risk and Fraud Scenarios in Affiliate Marketing Technologies
  from the Advertisers perspective

abstract:
  Affiliate Marketing (AM) has become an important and cost effective tool for
e-commerce. There are numerous risks and vulnerabilities that are typically
associated with AM. Though a well-planned AM model can greatly benefit the
e-commerce strategies of an enterprise, a haphazardly implemented system can
expose a business enterprise to major risks and vulnerabilities, which can lead
to great financial losses through fraudulent activities. This
research-in-progress has identified some of the risks and the technical
background of those scenarios. The research will now move on to build a
functional prototype of an AM network to design and test solutions to control
the identified risks.


title: Brief review on black hole loop quantization

abstract:
  Here, we present a review about the quantization of spherically-symmetric
spacetimes adopting loop quantum gravity techniques. Several models that have
been studied so far share similar properties: the resolution of the classical
singularity and some of them an intrinsic discretization of the geometry. We
also explain the extension to Reissner---Nordstr\"om black holes. Besides, we
review how quantum test fields on these quantum geometries allow us to study
phenomena, like the Casimir effect or Hawking radiation. Finally, we briefly
describe a recent proposal that incorporates spherically-symmetric matter,
discussing its relevance for the understanding of black hole evolution.


title: Visualizing the invisible the relentless pursuit of MTech Imaging

abstract:
  This teaching case describes the challenges faced by MTech Imaging, a
Singapore small and medium enterprise (SME) that specializes in providing
thermal imaging solutions. In recent years, the company has relentlessly
strived to become a digital innovative solution provider. This push has led to
the development of a disruptive digital innovation called the AXION platform.
Students are provided with vivid accounts of the journey undertaken by MTech to
develop the AXION platform, the industry it competes in, and the challenges it
faces in attempting to disrupt its industry through the introduction of the
AXION platform. The case seeks to achieve three learning objectives: (1) allow
students to learn from MTechs experiences in developing disruptive digital
innovation; (2) immerse students as senior management of MTech to substantiate
the best digital innovation strategy to adopt in order to disrupt its industry;
and (3) expose students to the challenges of driving the adoption of such
digital innovation in the market. It is hoped that the case can inspire
students to become effective digital innovation entrepreneurs.


title:
Leveraging ERP Implementation to Create Intellectual Capital: the Role
  of Organizational Learning Capability

abstract:
  The extent to which enterprise resource planning (ERP) systems deliver value
for organizations has been debated. In this study, we argue that the presence
of appropriate organizational resources is essential for capturing the
potential of ERP implementation. We investigate the relationship between ERP
implementation and two organizational resources, specifically, Intellectual
Capital (IC) and Organizational Learning Capability (OLC) to enrich the
understanding of the way the value of ERP implementations can be realized. A
sample of 226 manufacturing firms in Vietnam was surveyed to test the
theoretical model. Structural equation modelling with partial least square
method and two approaches for moderation analysis were used to analyze the
data. The results indicate that ERP implementation scope has a positive impact
on intellectual capital (IC). However, firms need to build a certain level of
OLC to utilize ERP implementation for the enhancement of IC.


title:
How to be a Good Frand in China: an Exploratory Study of Effective
  Social Media Behaviours for Foreign Brands

abstract:
  Many foreign companies see social media as a low cost marketing space for
entering the vast Chinese market. This is fraught with complexity, requiring an
understanding of social media behaviour, social media marketing, and the
Chinese context. In this exploratory pilot study, we develop the notion of
franding (online freinding of brands) as a unifying metaphor, and suggest that
effective social media brand strategies resemble effective online friend
behaviours. Based on this we develop some propositions and evaluate them
qualitatively in interviews with young Chinese consumers. Our study suggests
that conceptualizing brand social media relationships as a type of online
friendship can assist in harmonizing disparate literature and provide useful
insights for organizations operating in this complex area.


title:
Brundlefly at SemEval-2016 Task 12: Recurrent Neural Networks vs. Joint
  Inference for Clinical Temporal Information Extraction

abstract:
  We submitted two systems to the SemEval-2016 Task 12: Clinical TempEval
challenge, participating in Phase 1, where we identified text spans of time and
event expressions in clinical notes and Phase 2, where we predicted a relation
between an event and its parent document creation time.
  For temporal entity extraction, we find that a joint inference-based approach
using structured prediction outperforms a vanilla recurrent neural network that
incorporates word embeddings trained on a variety of large clinical document
sets. For document creation time relations, we find that a combination of date
canonicalization and distant supervision rules for predicting relations on both
events and time expressions improves classification, though gains are limited,
likely due to the small scale of training data.


title:
Appropriation of social media for knowledge sharing by patients with
  chronic illness

abstract:
  Social media technologies are increasingly utilized by patients, leading to
development of online social groups where patients share experiences and offer
support to their peers on these platforms. There is limited research
investigating actual use of social media platforms by patients, issues faced in
using such platforms and how appropriation of these platforms impact patient
outcomes. A conceptual model based on social support theory and model of
technology appropriation is proposed in order to investigate factors that
influence this phenomenon. The authors propose that social support theory and
model of technology appropriation could explain the determining factors, both
enablers and barriers that drive appropriation and knowledge sharing behaviours
of patients on social media platforms.


title:
Patterns of patterns of synchronization: Noise induced attractor
  switching in rings of coupled nonlinear oscillators

abstract:
  Following the long-lived qualitative-dynamics tradition of explaining
behavior in complex systems via the architecture of their attractors and
basins, we investigate the patterns of switching between qualitatively distinct
trajectories in a network of synchronized oscillators. Our system, consisting
of nonlinear amplitude-phase oscillators arranged in a ring topology with
reactive nearest neighbor coupling, is simple and connects directly to
experimental realizations. We seek to understand how the multiple stable
synchronized states connect to each other in state space by applying Gaussian
white noise to each of the oscillators' phases. To do this, we first identify a
set of locally stable limit cycles at any given coupling strength. For each of
these attracting states, we analyze the effect of weak noise via the covariance
matrix of deviations around those attractors. We then explore the noise-induced
attractor switching behavior via numerical investigations. For a ring of three
oscillators we find that an attractor-switching event is always accompanied by
the crossing of two adjacent oscillators' phases. For larger numbers of
oscillators we find that the distribution of times required to stochastically
leave a given state falls off exponentially, and we build an attractor
switching network out of the destination states as a coarse-grained description
of the high-dimensional attractor-basin architecture.


title:
The Use of ICT to preserve Australian Indigenous Culture and Language -
  a Preliminary Proposal using the Activity Theory Framework

abstract:
  Propinquity between Australian Indigenous communities' social structures and
ICT purposed for cultural preservation is a modern area of research;
historically hindered by the "digital divide" thus limiting plentiful
literature and existing information systems in this field in theoretical and
practical applications. Henceforth, community consultation is mandatory in
deriving and delivering empirically effective processes in a cultural and
language preservation IS tool designed to teach future generations of
Indigenous Australians about native culture and language. More than 100 out of
250 languages spoken by Indigenous have become extinct since 1788 (Harrington,
2014) which inaugurates the urgency of this preservation tool. ICT has been
identified as the best provision method; by its capacity to best collect,
eternize and teach cultural knowledge and language. The aim of this research is
to specify requirements and considerations for the development of a socially
integrated, culturally conscious, end-user driven IS to preserve Indigenous
culture in Australia.


title: Shuffling large decks of cards and the Bernoulli-Laplace urn model

abstract:
  In card games, in casino games with multiple decks of cards and in
cryptography, one is sometimes faced with the following problem: how can a
human (as opposed to a computer) shuffle a large deck of cards? The procedure
we study is to break the deck into several reasonably sized piles, shuffle each
thoroughly, recombine the piles, do some simple deterministic operation, for
instance a cut, and repeat. This process can also be seen as a generalised
Bernoulli-Laplace urn model. We use coupling arguments and spherical function
theory to derive upper and bounds on the mixing times of these Markov chains.


title:
Deformation quantization with separation of variables on a
  super-K\"ahler manifold

abstract:
  We construct deformation quantizations with separation of variables on a
split super-K\"ahler manifold and describe their canonical supertrace
densities.


title: Are we ready for spray-on carbon nanotubes?

abstract:
  Earlier this year, British sculptor, Anish Kapoor was given exclusive rights
to use a new spray-on carbon nanotube-based paint. The material, produced by
UK-based Surrey NanoSystems and marketed as Vantablack S-VIS, can be applied to
a range of surfaces, and absorbs well over 99% of the light that falls onto it.
It is claimed to be the world's blackest paint, and there is growing interest
in its use in works of art and high-end consumer products. It's easy to see the
appeal of Vantablack S-VIS. Apart from technical applications where stray
reflections need to be suppressed, this is a material that potentially enables
manufacturers and artists to give their products a unique aesthetic edge. Yet,
having worked on carbon nanotube safety for some years, I was intrigued to see
the material in a spray-paint designed to coat objects that people may possibly
come into contact with. It was, after all, only a few years ago that
journalists were asking if carbon nanotubes were the next asbestos. And while
this is unlikely, concerns over the possible health impacts of the material
persist.


title:
A benchmark of the He-like triplet for ions with $6\leq Z\leq 14$ in
  Maxwellian and non-Maxwellian plasmas

abstract:
  After an extensive assessment of the effective collision strengths available
to model the He-like triplet of C V, N VI, O VII, Ne IX, Mg XI and Si XIII in
collisionally dominated plasmas, new accurate effective collision strengths are
reported for Ne IX. The uncertainty intervals of the density and temperature
diagnostics due to the atomic data errors are also determined for both
Maxwell-Boltzmann and $\kappa$ electron-energy distributions. It is shown that
these uncertainty bands limit the temperature range where the temperature
line-ratio diagnostic can be applied and its effectiveness to discern the
electron-energy distribution type. These findings are benchmarked with Chandra
and XMM-Newton spectra of stellar coronae and with tokamak measurements.


title: Correlation and Substitution in SPARQL

abstract:
  In the current SPARQL specification the notion of correlation and
substitution are not well defined. This problem triggers several ambiguities in
the semantics. In fact, implementations as Fuseki and Virtuoso assume different
semantics.
  In this technical report, we provide a semantics of correlation and
substitution following the classic philosophy of substitution and correlation
in logic, programming languages and SQL. We think this proposal not only fix
the current ambiguities and problems, but helps to set a safe formal base to
further extensions of the language.
  This work is part of an ongoing work of Daniel Hernandez. These anomalies in
the W3C Specification of SPARQL 1.1 were detected early and reported no later
than 2014, when two erratas were registered (cf.
https://www.w3.org/2013/sparql-errata#errata-query-8 and
https://www.w3.org/2013/sparql-errata#errata-query-10).


title: Functional It\^o formula for fractional Brownian motion

abstract:
  We develop the functional It\^o/path-dependent calculus with respect to
fractional Brownian motion with Hurst parameter $H> \frac{1}{2}$. Firstly, two
types of integrals are studied. The first type is Stratonovich integral, and
the second type is Wick-It\^o integral. Then we establish the functional It\^o
formulas for fractional Brownian motion, which extend the functional It\^o
formulas in Dupire (2009) and Cont-Fourni\'e (2013) to the case of
non-semimartingale. Finally, as an application, we deal with a class of
fractional backward stochastic differential equations (BSDEs). A relation
between fractional BSDEs and path-dependent partial differential equations
(PDEs) is established.


title: Filters in the partition lattice

abstract:
  Given a filter $\Delta$ in the poset of compositions of $n$, we form the
filter $\Pi^{*}_{\Delta}$ in the partition lattice. We determine all the
reduced homology groups of the order complex of $\Pi^{*}_{\Delta}$ as
${\mathfrak S}_{n-1}$-modules in terms of the reduced homology groups of the
simplicial complex $\Delta$ and in terms of Specht modules of border shapes. We
also obtain the homotopy type of this order complex. These results generalize
work of Calderbank--Hanlon--Robinson and Wachs on the $d$-divisible partition
lattice. Our main theorem applies to a plethora of examples, including filters
associated to integer knapsack partitions and filters generated by all
partitions having block sizes $a$ or~$b$. We also obtain the reduced homology
groups of the filter generated by all partitions having block sizes belonging
to the arithmetic progression $a, a + d, \ldots, a + (a-1) \cdot d$, extending
work of Browdy.


title:
Thinking Out Loud and e-Health for Coordinated Care Lessons from User
  Requirements Gathering in the 4C Project

abstract:
  e-Health is a core part of Australias strategy to address rising costs and
changing demands for healthcare services. With over $1bn spent and only 6% of
Australians registered, the personally controlled electronic health record
(PCEHR) suggests user challenges remain. While evidence confirms the benefits
from involving users in systems development there is a need for more examples
of how to engage effectively in healthcare settings. This research describes
the use of an agile development methodology combined with the thinking out loud
technique to deliver a solution that exceeded user requirements in supporting a
new model of care. The 4C project solution connected Aged Care institutions
with general practices, hospitals and specialist services in Tasmanias
north-west region. It was underpinned by a model of Technology Mediated Social
Participation (TMSP). As a trial project for the PCEHR it remains unclear why
lessons learned appear not to have been deployed more explicitly in the
National roll-out.


title: Information Technology Platforms: Definition and Research Directions

abstract:
  The concept of an information technology (IT) related platform is broad and
covers phenomena ranging from the operating system Linux to the Internet. Such
platforms are of increasing importance to innovation and value creation across
many facets of industry and daily life. There is, however, a lack of common
understanding in both research and industry about what is mean by the term
platform when related to IT. This lack of consensus is detrimental to research
and knowledge development. Thus, the aims of this study are to: (i) provide a
sound definition of the IT-platform concept by identifying its distinguishing
dimensions; and (ii) identify important current research directions for the
IT-platform concept. To achieve these aims a systematic literature review was
undertaken with 133 relevant articles taken from major information systems
journals, conferences, and business publications. The study contributes by
providing a sound base for future research into IT-platforms.


title: The chord index, its definitions, applications and generalizations

abstract:
  In this paper we study the chord index of virtual knots, which can be thought
of as an extension of the chord parity. We show how to use the chord index to
define finite type invariants of virtual knots. The notions of indexed Jones
polynomial and indexed quandle are introduced, which generalize the classical
Jones polynomial and knot quandle respectively. Some applications of these new
invariants are discussed. We also study how to define a generalized chord index
via a fixed finite biquandle. Finally the chord index and its applications in
twisted knot theory are discussed.


title: Antecedents for Successful Collaboration in Requirements Engineering

abstract:
  The main focus of the requirements engineering (RE) literature has been on
the technical aspects related to the RE projects. Furthermore, research has
mainly focused on the specific methods for collecting the requirements for an
information system. To fill this gap, this paper studies the contribution of
social factors, such as social ties, knowledge sharing and flexibility, to
successful collaboration in RE teams. Data were collected from a successful RE
and development project in a public sector company in Finland. The results
suggest that human-related issues, such as flexibility and transactive memory,
were important for collaborative work in the RE team studied. The paper
concludes by discussing the implications for theory and suggesting practical
guidelines to enhance collaborative work in RE teams.


title:
Evaluating the Utility of Research Articles for Teaching Information
  Security Management

abstract:
  Research articles can support teaching by introducing the latest expert
thinking on relevant topics and trends and describing practical real-world case
studies to encourage discussion and analysis. However, from the point of view
of the instructor, a common challenge is identifying the most suitable papers
for classroom teaching amongst a very large pool of potential candidates that
are not typically written for teaching purposes. Further, even in
practice-oriented disciplines such as Information Security Management (ISM),
high-quality journals emphasise theoretical contribution and research method
rather than relevance to practice. Our review of the relevant literature did
not find a comprehensive set of criteria to assist instructors in evaluating
the suitability of research articles to teaching. Therefore, this
research-in-progress paper presents a framework to support academics in the
process of evaluating the suitability of research articles for their teaching
programs.


title:
Conceptual Knowledge Relationship Model of Enterprise Architecture and
  Top Management Roles

abstract:
  Enterprise Architecture (EA) continues to gain global recognition as a
management tool that would improve the organizations performance. However,
based on literature, it was found that the lack of EA knowledge of top
management (TM) hinders the assimiliation of EA. This study aims to gauge EA
knowledge required for TM for providing a comprehensive support towards EA
assimiliation. A semi-structured interviews were conducted with several
personnels in an organization. Data were analyzed using the constant
comparative method. This study found two sets of EA knowledge of TM; business
knowledge and technology knowledge. A conceptual knowledge relationship model
is proposed through synthesizing the roles of EA and TM in supporting the TM in
identifying the EA knowledge required. The findings gave contribution to
academicians and practitioners with knowledge of how to improve EA
assimiliation and a structured roadmap for understanding EA to achieve high
business value.


title:
Understanding Knowledge Leakage & BYOD (Bring Your Own Device): A Mobile
  Worker Perspective

abstract:
  Knowledge sharing drives innovation and the opportunity to develop a
sustainable competitive advantage. However, in the extant knowledge management
and information security literature, leakage from sharing activities is
neglected. The risk of knowledge leakage is exacerbated with the pervasive use
of mobile devices and the adoption of BYOD (Bring Your Own Device). Thus, this
research-in-progress paper examines the role of the behavior of mobile workers
that engage in accidental knowledge leakage through the use of BYOD. We use the
Decomposed Theory of Planned Behavior (DTPB) to explain the causes behind this
phenomenon and how it negatively impacts organization's competitive advantage.
The contributions of this study are the following. First, it posits that the
reasons of knowledge leakage by mobile workers through BYOD can be explained
using DTPB. Second, the paper proposes a conceptual model for research based on
DTPB constructs whilst adding other variables such as BYOD and mobile device
usage context. Finally, the conceptual study outlines the potential
contributions and implications of this research.


title:
Liveness of Randomised Parameterised Systems under Arbitrary Schedulers
  (Technical Report)

abstract:
  We consider the problem of verifying liveness for systems with a finite, but
unbounded, number of processes, commonly known as parameterised systems.
Typical examples of such systems include distributed protocols (e.g. for the
dining philosopher problem). Unlike the case of verifying safety, proving
liveness is still considered extremely challenging, especially in the presence
of randomness in the system. In this paper we consider liveness under arbitrary
(including unfair) schedulers, which is often considered a desirable property
in the literature of self-stabilising systems. We introduce an automatic method
of proving liveness for randomised parameterised systems under arbitrary
schedulers. Viewing liveness as a two-player reachability game (between
Scheduler and Process), our method is a CEGAR approach that synthesises a
progress relation for Process that can be symbolically represented as a
finite-state automaton. The method is incremental and exploits both
Angluin-style L*-learning and SAT-solvers. Our experiments show that our
algorithm is able to prove liveness automatically for well-known randomised
distributed protocols, including Lehmann-Rabin Randomised Dining Philosopher
Protocol and randomised self-stabilising protocols (such as the Israeli-Jalfon
Protocol). To the best of our knowledge, this is the first fully-automatic
method that can prove liveness for randomised protocols.


title:
Maturity of the Internet of Things Research Field: Or Why Choose
  Rigorous Keywords

abstract:
  Periodically researchers examine their fields of research in order to test
the fields maturity, to determine theories and methods used, and to uncover
areas of research emphasis. Research articles for these studies are generally
located through keyword search, then manually read and coded in order to
summarise the research field. This research tests using metadata analysis
alone, on the internet of things (IoT) research field, using data extracted
from three academic databases. The metadata analysis was proposed to reduce
time in analysis, and allow for testing of a much larger sample of articles.
Findings indicated that the IoT research field was immature, with experimental
methods dominating research outputs. However, difficulties with keyword
metadata included synonyms, abbreviations, lack of accuracy, and method and
theory not being included in metadata. A keyword schema is suggested in order
to relieve these problems in future articles, and to assist researchers in
locating relevant literature.


title:
An Interactive Medical Image Segmentation Framework Using Iterative
  Refinement

abstract:
  Image segmentation is often performed on medical images for identifying
diseases in clinical evaluation. Hence it has become one of the major research
areas. Conventional image segmentation techniques are unable to provide
satisfactory segmentation results for medical images as they contain
irregularities. They need to be pre-processed before segmentation. In order to
obtain the most suitable method for medical image segmentation, we propose a
two stage algorithm. The first stage automatically generates a binary marker
image of the region of interest using mathematical morphology. This marker
serves as the mask image for the second stage which uses GrabCut on the input
image thus resulting in an efficient segmented result. The obtained result can
be further refined by user interaction which can be done using the Graphical
User Interface (GUI). Experimental results show that the proposed method is
accurate and provides satisfactory segmentation results with minimum user
interaction on medical as well as natural images.


title: IT outsourcing decision factors in research and practice: a case study

abstract:
  The concurrent effect of various internal and external factors on IT
Outsourcing (ITO) decision making has seldom been investigated in a single
study. Furthermore, research on external factors is scarce and there is no
comprehensive theory that can fully explain ITO decisions made in practice.
This paper explains how key decision factors, both internal and external,
influence ITO decision making in a large Australian University. We also tested
the feasibility of a highly regarded descriptive model of ITO decisions as the
basic foundation of an ITO decision theory. The model failed to fully explain
ITO decisions in our case organisation. We draw researchers' attention to the
need for more exploration of external factors as well as clarification of
contingency factors that may explain inconsistencies between ITO decision
theories and practice, and call for more research for 'practicable' ITO
decision aids. Implications for practice are also discussed in the paper.


title: Multimodal Residual Learning for Visual QA

abstract:
  Deep neural networks continue to advance the state-of-the-art of image
recognition tasks with various methods. However, applications of these methods
to multimodality remain limited. We present Multimodal Residual Networks (MRN)
for the multimodal residual learning of visual question-answering, which
extends the idea of the deep residual learning. Unlike the deep residual
learning, MRN effectively learns the joint representation from vision and
language information. The main idea is to use element-wise multiplication for
the joint residual mappings exploiting the residual learning of the attentional
models in recent studies. Various alternative models introduced by
multimodality are explored based on our study. We achieve the state-of-the-art
results on the Visual QA dataset for both Open-Ended and Multiple-Choice tasks.
Moreover, we introduce a novel method to visualize the attention effect of the
joint representations for each learning block using back-propagation algorithm,
even though the visual features are collapsed without spatial information.


title:
Open Food Network: the Role of ICT to Support Regional Food Supply
  Chains in Australia

abstract:
  Many organizations have introduced various ICT-enabled innovations to improve
economic, environmental and social performance. The Open Food Network (OFN) is
an example of ICT-enabled innovation that has the potential to enhance the
sustainability of regional food supply chain by improving farmers access to
local and regional markets and consumers access to fresh local produce, as well
as optimizing the regional food distribution and improving local community
welfare. OFN has just been recently launched in Australia and currently there
is a limited understanding of the actual impacts and appropriate strategies to
encourage wider adoption. This research in progress aims to evaluate the
effectiveness of the OFN system in connecting and supporting the sustainability
of regional food supply chain communities in Australia that will help devise
strategies for expanding the use beyond Australia. Through a preliminary focus
group with a number of early adopters of the OFN, this study identifies the
actual use of OFN, benefits to main stakeholders and a number of challenges.
The findings contribute to a longer term research program that investigates how
ICT can support sustainability initiatives within organizations and supply
chains.


title: Approximately Envy-Free Spectrum Allocation with Complementarities

abstract:
  With spectrum auctions as our prime motivation, in this paper we analyze
combinatorial auctions where agents' valuations exhibit complementarities.
Assuming that the agents only value bundles of size at most $k$ and also
assuming that we can assess prices, we present a mechanism that is efficient,
approximately envy-free, asymptotically strategy-proof and that has
polynomial-time complexity. Modifying an iterative rounding procedure from
assignment problems, we use the primal and dual optimal solutions to the linear
programming relaxation of the auction problem to construct a lottery for the
allocations and to assess the prices to bundles. The allocations in the lottery
over-allocate goods by at most $k-1$ units, and the dual prices are shown to be
(approximately) envy-free irrespective of the allocation chosen. We conclude
with a detailed numerical investigation of a specific spectrum allocation
problem.


title: Casimir switch: steering optical transparency with vacuum forces

abstract:
  The Casimir force, originating from vacuum zero-point energy, is one of the
most intriguing purely quantum effects. It has attracted renewed interests in
current field of nanomechanics, due to the rapid size decrease of on-chip
devices. Here we study the optomechanically-induced transparency (OMIT) with a
tunable Casimir force. We find that the optical output rate can be
significantly altered by the vacuum force, even terminated and then restored,
indicating a highly-controlled optical switch. Our result addresses the
possibility of designing exotic optical nano-devices by harnessing the power of
vacuum.


title: Ulrich Bundles on Enriques Surfaces

abstract:
  We study Ulrich bundles and their moduli on unnodal Enriques surfaces. In
particular, we prove that unnodal Enriques surfaces are of wild representation
type by constructing moduli spaces of stable Ulrich bundles of arbitrary rank
and arbitrarily large dimension.


title: Nighttime Haze Removal with Illumination Correction

abstract:
  Haze removal is important for computational photography and computer vision
applications. However, most of the existing methods for dehazing are designed
for daytime images, and cannot always work well in the nighttime. Different
from the imaging conditions in the daytime, images captured in nighttime haze
condition may suffer from non-uniform illumination due to artificial light
sources, which exhibit low brightness/contrast and color distortion. In this
paper, we present a new nighttime hazy imaging model that takes into account
both the non-uniform illumination from artificial light sources and the
scattering and attenuation effects of haze. Accordingly, we propose an
efficient dehazing algorithm for nighttime hazy images. The proposed algorithm
includes three sequential steps. i) It enhances the overall brightness by
performing a gamma correction step after estimating the illumination from the
original image. ii) Then it achieves a color-balance result by performing a
color correction step after estimating the color characteristics of the
incident light. iii) Finally, it remove the haze effect by applying the dark
channel prior and estimating the point-wise environmental light based on the
previous illumination-balance result. Experimental results show that the
proposed algorithm can achieve illumination-balance and haze-free results with
good color rendition ability.


title: Ballistic Orbits and Front Speed Enhancement for ABC Flows

abstract:
  We study the two main types of trajectories of the ABC flow in the
near-integrable regime: spiral orbits and edge orbits. The former are helical
orbits which are perturbations of similar orbits that exist in the integrable
regime, while the latter exist only in the non-integrable regime. We prove
existence of ballistic (i.e., linearly growing) spiral orbits by using the
contraction mapping principle in the Hamiltonian formulation, and we also find
and analyze ballistic edge orbits. We discuss the relationship of existence of
these orbits with questions concerning front propagation in the presence of
flows, in particular, the question of linear (i.e., maximal possible) front
speed enhancement rate for ABC flows.


title:
Asymptotic properties of a stochastic Gilpin-Ayala model under regime
  switching

abstract:
  In this paper, a stochastic Gilpin-Ayala population model with regime
switching and white noise is considered. All parameters are influenced by
stochastic perturbations. The existence of global positive solution, asymptotic
stability in probability, $p$th moment exponential stability, extinction, weak
persistence, stochastic permanence and stationary distribution of the model are
investigated, which generalize some results in the literatures. Moreover, the
conditions presented for the stochastic permanence and the existence of
stationary distribution improve the previous results.


title:
Specializing varieties and their cohomology from characteristic $0$ to
  characteristic $p$

abstract:
  We present a semicontinuity result, proven in recent joint work with Morrow
and Scholze, relating the mod $p$ singular cohomology of a smooth projective
complex algebraic variety X to the de Rham cohomology of a smooth
characteristic $p$ specialization of X: the rank of the former is bounded above
by that of the latter. The path to this result passes through $p$-adic Hodge
theory and perfectoid geometry, so we survey the relevant aspects of those
subjects as well.


title: Motion-corrected Fourier ptychography

abstract:
  Fourier ptychography (FP) is a recently proposed computational imaging
technique for high space-bandwidth product imaging. In real setups such as
endoscope and transmission electron microscope, the common sample motion
largely degrades the FP reconstruction and limits its practicability. In this
paper, we propose a novel FP reconstruction method to efficiently correct for
unknown sample motion. Specifically, we adaptively update the sample's Fourier
spectrum from low spatial-frequency regions towards high spatial-frequency
ones, with an additional motion recovery and phase-offset compensation
procedure for each sub-spectrum. Benefiting from the phase retrieval redundancy
theory, the required large overlap between adjacent sub-spectra offers an
accurate guide for successful motion recovery. Experimental results on both
simulated data and real captured data show that the proposed method can correct
for unknown sample motion with its standard deviation being up to 10% of the
field-of-view scale. We have released our source code for non-commercial use,
and it may find wide applications in related FP platforms such as endoscopy and
transmission electron microscopy.


title: Numerical Study of Nonlinear Dispersive Wave Models with SpecTraVVave

abstract:
  In nonlinear dispersive evolution equations, the competing effects of
nonlinearity and dispersion make a number of interesting phenomena possible. In
the current work, the focus is on the numerical approximation of traveling-wave
solutions of such equations. We describe our efforts to write a dedicated
Python code which is able to compute traveling-wave solutions of nonlinear
dispersive equations of the general form \begin{equation*} u_t + [f(u)]_{x} +
\mathcal{L} u_x = 0, \end{equation*} where $\mathcal{L}$ is a self-adjoint
operator, and $f$ is a real-valued function with $f(0) = 0$.
  The SpectraVVave code uses a continuation method coupled with a spectral
projection to compute approximations of steady symmetric solutions of this
equation. The code is used in a number of situations to gain an understanding
of traveling-wave solutions. The first case is the Whitham equation, where
numerical evidence points to the conclusion that the main bifurcation branch
features three distinct points of interest, namely a turning point, a point of
stability inversion, and a terminal point which corresponds to a cusped wave.
  The second case is the so-called modified Benjamin-Ono equation where the
interaction of two solitary waves is investigated. It is found that is possible
for two solitary waves to interact in such a way that the smaller wave is
annihilated. The third case concerns the Benjamin equation which features two
competing dispersive operators. In this case, it is found that bifurcation
curves of periodic traveling-wave solutions may cross and connect high up on
the branch in the nonlinear regime.


title:
Intranight Optical Variability of Radio-Quiet Weak Emission Line
  Quasars-IV

abstract:
  We report an extension of our program to search for radio-quiet BL Lac
candidates using intra-night optical variability (INOV) as a probe. The present
INOV observations cover a well-defined representative set of 10 `radio-quiet
weak-emission-line quasars' (RQWLQs), selected from a newly published sample of
46 such sources, derived from the Sloan Digital Sky Survey (Data release 7).
Intra-night CCD monitoring of the 10 RQWLQs was carried out in 18 sessions
lasting at least 3.5 hours. For each session, differential light curves (DLCs)
of the target RQWLQ were derived relative to two steady comparison stars
monitored simultaneously. Combining these new data with those already published
by us for 15 RQWLQs monitored in 30 sessions, we estimate an INOV duty cycle of
$\sim 3\%$ for the RQWLQs, which appears inconsistent with BL Lacs. However,
the observed INOV events (which occurred in just two of the sessions) are
strong (with a fractional variability amplitude $\psi >$ 10\%), hence
blazar-like. We briefly point out the prospects of an appreciable rise in the
estimated INOV duty cycle for RQWLQs with a relatively modest increase in
sensitivity for monitoring these rather faint objects.


title: Deep Q-Networks for Accelerating the Training of Deep Neural Networks

abstract:
  In this paper, we propose a principled deep reinforcement learning (RL)
approach that is able to accelerate the convergence rate of general deep neural
networks (DNNs). With our approach, a deep RL agent (synonym for optimizer in
this work) is used to automatically learn policies about how to schedule
learning rates during the optimization of a DNN. The state features of the
agent are learned from the weight statistics of the optimizee during training.
The reward function of this agent is designed to learn policies that minimize
the optimizee's training time given a certain performance goal. The actions of
the agent correspond to changing the learning rate for the optimizee during
training. As far as we know, this is the first attempt to use deep RL to learn
how to optimize a large-sized DNN. We perform extensive experiments on a
standard benchmark dataset and demonstrate the effectiveness of the policies
learned by our approach.


title: Two Dimensional Classification of the Swift/BAT GRBs

abstract:
  Using Gaussian Mixture Model and Expectation Maximization algorithm, we have
performed a density estimation in the framework of $T_{90}$ versus hardness
ratio for 296 Swift/BAT GRBs with known redshift. Here, Bayesian Information
Criterion has been taken to compare different models. Our investigations show
that two instead of three or more Gaussian components are favoured in both the
observer and rest frames. Our key findings are consistent with some previous
results.


title:
On the classification of 4-dimensional $(m,\rho)$-quasi-Einstein
  manifolds with harmonic Weyl curvature

abstract:
  In this paper we study 4-dimensional $(m,\rho)$-quasi-Einstein manifolds with
harmonic Weyl curvature when $m\notin\{0,\pm1,-2,\pm\infty\}$ and
$\rho\notin\{\frac{1}{4},\frac{1}{6}\}$. We prove that a non-trivial
$(m,\rho)$-quasi-Einstein metric $g$ (not necessarily complete) is locally
isometric to one of the followings: (i) $\mathcal{B}^2_\frac{R}{2(m+2)}\times
\mathbb{N}^2_\frac{R(m+1)}{2(m+2)}$ where $\mathcal{B}^2_\frac{R}{2(m+2)}$ is a
northern hemisphere in the 2-dimensional sphere
$\mathbb{S}^2_\frac{R}{2(m+2)}$, $\mathbb{N}_\delta$ is the 2-dimensional
Riemannian manifold with constant curvature $\delta$ and $R$ is the constant
scalar curvature of $g$, (ii)
$\mathcal{D}^2_\frac{R}{2(m+2)}\times\mathbb{N}^2_\frac{R(m+1)}{2(m+2)}$ where
$\mathcal{D}^2_\frac{R}{2(m+2)}$ is one half (cut by a hyperbolic line) of the
hyperbolic plane $\mathbb{H}^2_\frac{R}{2(m+2)}$, (iii)
$\mathbb{H}^2_\frac{R}{2(m+2)}\times\mathbb{N}^2_\frac{R(m+1)}{2(m+2)}$, (iv) a
certain singular metric with $\rho=0$, (vi) a locally conformally flat metric.
By applying this local classification, we obtain a classification of complete
$(m,\rho)$-quasi-Einstein manifolds under the harmonic Weyl curvature
condition. Our result can be viewed as a local classification of gradient
Einstein-type manifolds. One corollary of our result is the classification of
$(\lambda,4+m)$-Einstein manifolds which can be viewed as
$(m,0)$-quasi-Einstein manifolds.


title:
Enhanced superconductivity accompanying a Lifshitz transition in
  electron-doped FeSe monolayer

abstract:
  The origin of enhanced superconductivity over 50 K in the recently discovered
FeSe monolayer films grown on SrTiO$_{3}$ (STO), as compared to 8 K in bulk
FeSe, is intensely debated. As with the ferrochalcogenides
A$_{x}$Fe$_{2-y}$Se$_{2}$ and potassium doped FeSe, which also have a
relatively high superconducting critical temperature ($T_c$), the Fermi surface
(FS) of the FeSe/STO monolayer films is free of hole-like FS, suggesting that a
Lifshitz transition by which these hole FSs vanish may help increasing $T_c$.
However, the fundamental reasons explaining this increase of $T_c$ remain
unclear. Here we report a 15 K jump of $T_c$ accompanying a second Lifshitz
transition, characterized by the emergence of an electron pocket at the
Brillouin zone (BZ) centre, that is triggered by high electron doping following
in-situ deposition of potassium on FeSe/STO monolayer films. Our results
suggest that the pairing interactions are orbital-dependent with the $d_{xy}$
orbital playing a determining role in generating enhanced superconductivity in
FeSe.


title:
MUSE integral-field spectroscopy towards the Frontier Fields cluster
  Abell S1063: II. Properties of low luminosity Lyman alpha emitters at z>3

abstract:
  In spite of their conjectured importance for the Epoch of Reionization, the
properties of low-mass galaxies are currently still under large debate. In this
article, we study the stellar and gaseous properties of faint, low-mass
galaxies at z>3. We observed the Frontier Fields cluster Abell S1063 with MUSE
over a 2 arcmin^2 field, and combined integral-field spectroscopy with
gravitational lensing to perform a blind search for intrinsically faint Lya
emitters (LAEs). We determined in total the redshift of 172 galaxies of which
14 are lensed LAEs at z=3-6.1. We increased the number of
spectroscopically-confirmed multiple-image families from 6 to 17 and updated
our gravitational-lensing model accordingly. The lensing-corrected Lya
luminosities are with L(Lya) <= 10^41.5 erg/s among the lowest for
spectroscopically confirmed LAEs at any redshift. We used expanding gaseous
shell models to fit the Lya line profile, and find low column densities and
expansion velocities. This is to our knowledge the first time that gaseous
properties of such faint galaxies at z>=3 are reported. We performed SED
modelling to broadband photometry from the U-band through the infrared to
determine the stellar properties of these LAEs. The stellar masses are very low
(10^{6-8} Msun), and are accompanied by very young ages of 1-100 Myr. The very
high specific star formation rates (~100 Gyr^-1) are characteristic of
starburst galaxies. The UV-continuum slopes beta are low in our sample, with
beta<-2 for all galaxies with M_star<10^8 Msun. We conclude that our low-mass
galaxies at 3<z<6 are forming stars at higher rates when correcting for stellar
mass effects than seen locally or in more massive galaxies. The young stellar
populations with high star-formation rates and low HI column densities lead to
continuum slopes and LyC-escape fractions expected for a scenario where low
mass galaxies reionise the Universe.


title: Interpretable Dynamic Treatment Regimes

abstract:
  Precision medicine is currently a topic of great interest in clinical and
intervention science. One way to formalize precision medicine is through a
treatment regime, which is a sequence of decision rules, one per stage of
clinical intervention, that map up-to-date patient information to a recommended
treatment. An optimal treatment regime is defined as maximizing the mean of
some cumulative clinical outcome if applied to a population of interest. It is
well-known that even under simple generative models an optimal treatment regime
can be a highly nonlinear function of patient information. Consequently, a
focal point of recent methodological research has been the development of
flexible models for estimating optimal treatment regimes. However, in many
settings, estimation of an optimal treatment regime is an exploratory analysis
intended to generate new hypotheses for subsequent research and not to directly
dictate treatment to new patients. In such settings, an estimated treatment
regime that is interpretable in a domain context may be of greater value than
an unintelligible treatment regime built using "black-box" estimation methods.
We propose an estimator of an optimal treatment regime composed of a sequence
of decision rules, each expressible as a list of "if-then" statements that can
be presented as either a paragraph or as a simple flowchart that is immediately
interpretable to domain experts. The discreteness of these lists precludes
smooth, i.e., gradient-based, methods of estimation and leads to non-standard
asymptotics. Nevertheless, we provide a computationally efficient estimation
algorithm, prove consistency of the proposed estimator, and derive rates of
convergence. We illustrate the proposed methods using a series of simulation
examples and application to data from a sequential clinical trial on bipolar
disorder.


title: Confidence Intervals for Algorithmic Leveraging in Linear Regression

abstract:
  The age of big data has produced data sets that are computationally expensive
to analyze and store. Algorithmic leveraging proposes that we sample
observations from the original data set to generate a representative data set
and then perform analysis on the representative data set. In this paper, we
present efficient algorithms for constructing finite sample confidence
intervals for each algorithmic leveraging estimated regression coefficient,
with asymptotic coverage guarantees. In simulations, we confirm empirically
that the confidence intervals have the desired coverage probabilities, while
bootstrap confidence intervals may not.


title:
$B \to K^* \ell \ell$ Standard Model contributions -- Zooming in on high
  $q^2$

abstract:
  To further precision studies with $B \to K^{(*)} \ell \ell$ decays in the
high-$q^2$ window uncertainties related to the operator product expansion (OPE)
need to be scrutinized. How well can the OPE describe $B \to K^* (\to K \pi)
\ell \ell$ angular distributions for a given binning in view of the local charm
resonance structure? We present a data-driven method to access this
quantitatively. Our analysis suggests that the bins which are near the
kinematic endpoint are best described by the OPE and should be pursued for
precision studies. At the same time measurements with finer binning help
controlling the uncertainties.


title:
New conserved currents for vacuum space-times in dimension four with a
  Killing vector

abstract:
  A new family of conserved currents for vacuum space-times with a Killing
vector is presented. The currents are constructed from the superenergy tensor
of the Mars-Simon tensor and using the positivity properties of the former we
find that the conserved charges associated to the currents have natural
positivity properties in certain cases. Given the role played by the Mars-Simon
tensor in local and semi-local characterisations of the Kerr solution, the
currents presented in this work are useful to construct non-negative scalar
quantities characterising Kerr initial data (known in the literature as
non-Kerrness) which in addition are conserved charges.


title:
Generation and removal of apparent singularities in linear ordinary
  differential equations with polynomial coefficients

abstract:
  We discuss several examples of generating apparent singular points as a
result of differentiating particular homogeneous linear ordinary differential
equations with polynomial coefficients and formulate two general conjectures on
the generation and removal of apparent singularities in arbitrary Fuchsian
differential equations with polynomial coefficients. We consider a model
problem in polymer physics.


title:
Enhanced critical-current in P-doped BaFe2As2 thin films on metal
  substrates arising from poorly aligned grain boundaries

abstract:
  Thin films of the iron-based superconductor BaFe2(As1-xPx)2 (Ba122:P) were
fabricated on polycrystalline metal-tape substrates with two kinds of in-plane
grain boundary alignments (well aligned (4 deg.) and poorly aligned (8 deg.))
by pulsed laser deposition. The poorly aligned substrate is not applicable to
cuprate-coated conductors because the in-plane alignment >4 deg. results in
exponential decay of the critical current density (Jc). The Ba122:P film
exhibited higher Jc at 4 K when grown on the poorly aligned substrate than on
the well-aligned substrate even though the crystallinity was poorer. It was
revealed that the misorientation angles of the poorly aligned samples were less
than 6 deg., which are less than the critical angle of an iron-based
superconductor, cobalt-doped BaFe2As2 (~9 deg.), and the observed strong
pinning in the Ba122:P is attributed to the high-density grain boundaries with
the misorientation angles smaller than the critical angle. This result reveals
a distinct advantage over cuprate-coated conductors because well-aligned
metal-tape substrates are not necessary for practical applications of the
iron-based superconductors.


title: All states are nonclassical: entanglement of joint statistics

abstract:
  Joint measurements of two observables reveal that every state is
nonclassical, with the only trivial exception of the state with density matrix
proportional to the identity. This naturally includes states considered
universally as classical-like, such as SU(2) and Glauber coherent states. We
show that this holds because we can always find a joint measurement whose
statistics is not separable.


title: Short range networks of wearables for safer mobility in smart cities

abstract:
  Ensuring safe and efficient mobility is a critical issue for smart city
operators. Increasing safety not only reduces the likelihood of road injuries
and fatalities, but also reduces traffic congestion and disruptions caused by
accidents, increasing efficiency. While new vehicles are increasingly equipped
with semi-automation, the added costs will initially limit the penetration rate
of these systems. An inexpensive way to replace or augment these systems is to
create networks of wearables (smart glasses, watches) that exchange positional
and path data at a very fast rate between all users, identify collision risks
and feedback collision resolution information to all users in an intuitive way
through their smart glasses.


title: Constraining the production of cosmic rays by pulsars

abstract:
  One of the possible sources of hadronic cosmic rays (CRs) are newborn
pulsars. If this is indeed the case, they should feature diffusive gamma-ray
halos produced by interactions of CRs with interstellar gas. In this paper we
try to identify extended gamma-ray emission around young pulsars, making use of
the 7-year Fermi-LAT data. For this purpose we select and analyze a set of
eight pulsars that are most likely to possess detectable gamma-ray halos. We
find extended emission that might be interpreted as a gamma-ray halo only in
the case of PSR J0007+7303. Its luminosity accords with the total energy of
injected cosmic rays $\sim 10^{50}$ erg, although other interpretations of this
source are possible. Irrespectively of the nature of this source we put bounds
on the luminosity of gamma-ray halos which suggest that pulsars' contribution
to the overall energy budget of galactic CRs is subdominant in the GeV-TeV
range.


title: Better Image Segmentation by Exploiting Dense Semantic Predictions

abstract:
  It is well accepted that image segmentation can benefit from utilizing
multilevel cues. The paper focuses on utilizing the FCNN-based dense semantic
predictions in the bottom-up image segmentation, arguing to take semantic cues
into account from the very beginning. By this we can avoid merging regions of
similar appearance but distinct semantic categories as possible. The semantic
inefficiency problem is handled. We also propose a straightforward way to use
the contour cues to suppress the noise in multilevel cues, thus to improve the
segmentation robustness. The evaluation on the BSDS500 shows that we obtain the
competitive region and boundary performance. Furthermore, since all individual
regions can be assigned with appropriate semantic labels during the
computation, we are capable of extracting the adjusted semantic segmentations.
The experiment on Pascal VOC 2012 shows our improvement to the original
semantic segmentations which derives directly from the dense predictions.


title: An improved method for polarimetric image restoration in interferometry

abstract:
  Interferometric radio astronomy data require the effects of limited coverage
in the Fourier plane to be accounted for via a deconvolution process. For the
last 40 years this process, known as `cleaning', has been performed almost
exclusively on all Stokes parameters individually as if they were independent
scalar images. However, here we demonstrate for the case of the linear
polarisation $\mathcal{P}$, this approach fails to properly account for the
complex vector nature resulting in a process which is dependant on the axis
under which the deconvolution is performed. We present here an improved method,
`Generalised Complex CLEAN', which properly accounts for the complex vector
nature of polarised emission and is invariant under rotations of the
deconvolution axis. We use two Australia Telescope Compact Array datasets to
test standard and complex CLEAN versions of the H\"{o}gbom and SDI CLEAN
algorithms. We show that in general the Complex CLEAN version of each algorithm
produces more accurate clean components with fewer spurious detections and
lower computation cost due to reduced iterations than the current methods. In
particular we find that the Complex SDI CLEAN produces the best results for
diffuse polarised sources as compared with standard CLEAN algorithms and other
Complex CLEAN algorithms. Given the move to widefield, high resolution
polarimetric imaging with future telescopes such as the Square Kilometre Array,
we suggest that Generalised Complex CLEAN should be adopted as the
deconvolution method for all future polarimetric surveys and in particular that
the complex version of a SDI CLEAN should be used.


title:
Exponential decay estimates of the eigenvalues for the
  Neumann-Poincar\'e operator on analytic boundaries in two dimensions

abstract:
  We show that the eigenvalues of the Neumann-Poincar\'e operator on analytic
boundaries of simply connected bounded planar domains tend to zero
exponentially fast, and the exponential convergence rate is determined by the
maximal Grauert radius of the boundary. We present a few examples of boundaries
to show that the estimate is optimal.


title: Relaxation of the EM Algorithm via Quantum Annealing

abstract:
  The EM algorithm is a novel numerical method to obtain maximum likelihood
estimates and is often used for practical calculations. However, many of
maximum likelihood estimation problems are nonconvex, and it is known that the
EM algorithm fails to give the optimal estimate by being trapped by local
optima. In order to deal with this difficulty, we propose a deterministic
quantum annealing EM algorithm by introducing the mathematical mechanism of
quantum fluctuations into the conventional EM algorithm because quantum
fluctuations induce the tunnel effect and are expected to relax the difficulty
of nonconvex optimization problems in the maximum likelihood estimation
problems. We show a theorem that guarantees its convergence and give numerical
experiments to verify its efficiency.

categories: stat.ML cond-mat.stat-mech math.ST physics.comp-ph quant-ph stat.TH


title: The rate of weak convergence of the n-point motions of Harris flows

abstract:
  In this paper we discuss the Wasserstein distance between the n-point motions
of Harris flows whose covariance functions have compact support. We prove that
it can be estimated by the diameters of their support provided the latter are
sufficiently small.


title: Controlling electromagnetic scattering with wire metamaterial resonators

abstract:
  Manipulation of radiation is required for enabling a span of electromagnetic
applications. Since properties of antennas and scatterers are very sensitive to
a surrounding environment, macroscopic artificially created materials are good
candidates for shaping their characteristics. In particular, metamaterials
enable controlling both dispersion and density of electromagnetic states,
available for scattering from an object. As the result, properly designed
electromagnetic environment could govern waves' phenomena. Here electromagnetic
properties of scattering dipoles, situated inside a wire medium (metamaterial)
are analyzed both numerically and experimentally. Impact of the metamaterial
geometry, dipole arrangement inside the medium, and frequency of the incident
radiation on scattering phenomena was studied. It was shown that the resonance
of the dipole hybridizes with Fabry-Perot modes of the metamaterial, giving
rise to a complete reshaping of electromagnetic properties. Regimes of
controlled scattering suppression and super-scattering were observed. Numerical
analysis is in an agreement with experiments, performed at the GHz spectral
range. The reported approach to scattering control with metamaterials could be
directly mapped into optical and infrared spectral ranges by employing
scalability properties of Maxwell's equations.


title: Bounds for Vector-Valued Function Estimation

abstract:
  We present a framework to derive risk bounds for vector-valued learning with
a broad class of feature maps and loss functions. Multi-task learning and
one-vs-all multi-category learning are treated as examples. We discuss in
detail vector-valued functions with one hidden layer, and demonstrate that the
conditions under which shared representations are beneficial for multi- task
learning are equally applicable to multi-category learning.


title:
Dynamical systems with a prescribed attracting set and applications to
  conservative dynamics

abstract:
  We provide an explicit method to construct dynamical systems which admit an
a-priori prescribed attracting set. As application, we provide a method to
construct perturbations of conservative dynamical systems, which admit an
a-priori prescribed leafwise attracting set.


title:
Two-nucleon scattering in a modified Weinberg approach with a
  symmetry-preserving regularization

abstract:
  We consider the nucleon-nucleon scattering problem by applying time-ordered
perturbation theory to the Lorentz invariant formulation of baryon chiral
perturbation theory. Using a symmetry preserving higher derivative form of the
effective Lagrangian, we exploit the freedom of the choice of the
renormalization condition and obtain an integral equation for the scattering
amplitude with an improved ultraviolet behavior. The resulting formulation is
used to quantify finite regulator artifacts in two-nucleon phase shifts as well
as in the chiral extrapolations of the S-wave scattering lengths and the
deuteron binding energy. This approach can be straightforwardly extended to
analyze few-nucleon systems and processes involving external electroweak
sources.


title: A Quantized Spacetime Based on $Spin(3,1)$ Symmetry

abstract:
  We introduce a new type of the spacetime quantization based on the spinorial
description suggested by loop quantum gravity. Specifically, we build our
theory on a string theory inspired $Spin(3,1)$ worldsheet action. Because of
its connection with quantum gravity theories, our proposal may in principle
link back to string theory, connect to loop quantum gravity where $SU(2)$ is
suggested as the fundamental symmetry, or serve as a Lorentzian spin network.
We derive the generalized uncertainty principle and demonstrate the holographic
nature of our theory. Due to the quantization of spacetime, geodesics in our
theory are fuzzy, but the fuzziness is shown to be much below conceivable
astrophysical bounds.


title:
Stochastic optimal control problem with infinite horizon driven by
  G-Brownian motion

abstract:
  The present paper considers a stochastic optimal control problem, in which
the cost function is defined through a backward stochastic differential
equation with infinite horizon driven by G-Brownian motion. Then we study the
regularities of the value function and establish the dynamic programming
principle. Moreover, we prove that the value function is the uniqueness
viscosity solution of the related HJBI equation.


title: Vector Dark Matter Detection using the Quantum Jump of Atoms

abstract:
  The hidden sector U(1) vector bosons created from inflationary fluctuations
can be a substantial fraction of dark matter if their mass is around
$10^{-5}$eV. The creation mechanism makes the vector bosons' energy spectral
density $\rho_{cdm}/\Delta E$ very high. Therefore, the dark electric dipole
transition rate in atoms is boosted if the energy gap between atomic states
equals the mass of the vector bosons. By using the Zeeman effect, the energy
gap between the 2S state and the 2P state in hydrogen atoms or hydrogen like
ions can be tuned. The $2S$ state can be populated with electrons due to its
relatively long life, which is about $1/7$s. When the energy gap between the
semi-ground $2S$ state and the 2P state matches the mass of the cosmic vector
bosons, induced transitions occur and the 2P state subsequently decays into the
1S state. The $2P\to1S$ decay emitted Lyman-$\alpha$ photons can then be
registered. The choices of target atoms depend on the experimental facilities
and the mass ranges of the vector bosons. Because the mass of the vector boson
is connected to the inflation scale, the proposed experiment may provide a
probe to inflation.

categories: hep-ph astro-ph.CO hep-ex physics.atom-ph physics.ins-det


title: A note on the order of the Schur multiplier of p-groups

abstract:
  Let $G$ be a finite $p$-group of order $p^n$ with $|G'| = p^k$. Let $M(G)$
denotes the Schur multiplier of $G$. A classical result of Green states that
$|M(G)| \leq p^{\frac{1}{2}n(n-1)}$. In 2009, Niroomand, improving Green's and
other bounds on $|M(G)|$ for a non-abelain $p$-group $G$, proved that $|M(G)|
\leq p^{\frac{1}{2}(n-k-1)(n+k-2)+1}$. In this article we note that a bound,
obtained earlier, by Ellis and Weigold is more general than the bound of
Niroomand. We derive from the bound of Ellis and Weigold that $|M(G)| \leq
p^{\frac{1}{2}(d(G)-1)(n+k-2)+1}$ for a non-abelain $p$-group $G$. Moreover, we
sharpen the bound of Ellis and Weigold and as a consequence derive that if
$G^{ab}$ is not homocyclic then $|M(G)| \leq p^{\frac{1}{2}(d(G)-1)(n+k-3)+1}$.
We further note an improvement in an old bound given by Vermani. Finally we
note, for a $p$-group of coclass $r$, that $|M(G)| \leq
p^{\frac{1}{2}(r^2-r)+kr+1}$. This improves a bound by Moravec.


title:
On the thermal line emission from the outflows in ultraluminous X-ray
  sources

abstract:
  The atomic features in the X-ray spectra of the ultraluminous X-ray source
(ULX) may be associated with the outflow (Middleton et al. 2015), which may
provide a way to explore the physics of the ULXs. We construct a conical
outflow model, and calculate the thermal X-ray Fe emission lines from the
outflows. Our results show that thermal line luminosity decreases with
increasing outflow velocity or/and opening angle of the outflow for a fixed
kinetic power of the outflows. Assuming the kinetic power of the outflows to be
comparable with the accretion power in the ULXs, we find that the equivalent
width can be several eV for the thermal X-ray Fe emission line from the
outflows in the ULXs with stellar mass black holes. The thermal line luminosity
is proportional to 1/M (M is the black hole mass of the ULX). The equivalent
width decreases with the black hole mass, which implies that the Fe line
emission from the outflows can hardly be detected if the ULXs contain
intermediate mass black holes. Our results suggest that the thermal X-ray Fe
line emission should be preferentially be detected in the ULXs with high
kinetic power slowly moving outflows from the accretion disks surrounding
stellar mass black holes/neutron stars. The recent observed X-ray atomic
features of the outflows in the ULX may imply that it contains a stellar mass
black hole/neutron star (Pinto et al. 2016).


title:
The Problem of Calibrating an Agent-Based Model of High-Frequency
  Trading

abstract:
  Agent-based models, particularly those applied to financial markets,
demonstrate the ability to produce realistic, simulated system dynamics,
comparable to those observed in empirical investigations. Despite this, they
remain fairly difficult to calibrate due to their tendency to be
computationally expensive, even with recent advances in technology. For this
reason, financial agent-based models are frequently validated by demonstrating
an ability to reproduce well-known log return time series and central limit
order book stylized facts, as opposed to being rigorously calibrated to
transaction data. We thus apply an established financial agent-based model
calibration framework to a simple model of high- and low-frequency trader
interaction and demonstrate possible inadequacies of a stylized fact-centric
approach to model validation. We further argue for the centrality of
calibration to the validation of financial agent-based models and possible
pitfalls of current approaches to financial agent-based modeling.


title: Bakry-\'Emery curvature functions of graphs

abstract:
  We study the Bakry-\'Emery curvature function
$\mathcal{K}_{G,x}:(0,\infty]\to \mathbb{R}$ of a vertex $x$ in a locally
finite graph $G$ systematically. Here $\mathcal{K}_{G,x}(\mathcal{N})$ is
defined as the optimal curvature lower bound $\mathcal{K}$ in the Bakry-\'Emery
curvature-dimension inequality $CD(\mathcal{K},\mathcal{N})$ that $x$
satisfies. We prove the curvature functions of the Cartesian product of two
graphs $G_1,G_2$ equal an abstract product of curvature functions of $G_1,G_2$.
We relate the curvature functions of $G$ with various spectral properties of
(weighted) graphs constructed from local structures of $G$. We explore the
curvature functions of Cayley graphs, strongly regular graphs, and many
particular (families of) examples including Johnson graphs and complete
bipartite graphs. We construct an infinite family of $6$-regular graphs which
satisfy $CD(0,\infty)$ but are not Cayley graphs.


title:
Epsilon factors as algebraic characters on the smooth dual of
  $\mathrm{GL}_n$

abstract:
  Let $K$ be a non-archimedean local field and let $G = \mathrm{GL}_n(K)$. We
have shown in previous work that the smooth dual $\mathbf{Irr}(G)$ admits a
complex structure: in this article we show how the epsilon factors interface
with this complex structure. The epsilon factors, up to a constant term, factor
as invariant characters through the corresponding complex tori. For the
arithmetically unramified smooth dual of $\mathrm{GL}_n$, we provide explicit
formulas for the invariant characters.


title: Entropic fluctuations in thermally driven harmonic networks

abstract:
  We consider a general network of harmonic oscillators driven out of thermal
equilibrium by coupling to several heat reservoirs at different temperatures.
The action of the reservoirs is implemented by Langevin forces. Assuming the
existence and uniqueness of the steady state of the resulting process, we
construct a canonical entropy production functional which satisfies the
Gallavotti--Cohen fluctuation theorem, i.e., a global large deviation principle
with a rate function I(s) obeying the Gallavotti--Cohen fluctuation relation
I(-s)-I(s)=s for all s. We also consider perturbations of our functional by
quadratic boundary terms and prove that they satisfy extended fluctuation
relations, i.e., a global large deviation principle with a rate function that
typically differs from I(s) outside a finite interval. This applies to various
physically relevant functionals and, in particular, to the heat dissipation
rate of the network. Our approach relies on the properties of the maximal
solution of a one-parameter family of algebraic matrix Riccati equations. It
turns out that the limiting cumulant generating functions of our functional and
its perturbations can be computed in terms of spectral data of a Hamiltonian
matrix depending on the harmonic potential of the network and the parameters of
the Langevin reservoirs. This approach is well adapted to both analytical and
numerical investigations.

categories: math-ph math.DS math.MP math.PR physics.class-ph


title: Metacoatings for wavelength scale, high NA plano-concave focusing lenses

abstract:
  We design plano-concave silicon lenses with coupled gradient-index plasmonic
metacoatings for ultrawide apertured focusing utilizing a reduced region of
$\sim 20 \lambda^2$. The anomalous refraction induced in the planar input side
of the lens and in the boundary of the wavelength-scale focal region boosts the
curvature of the emerging wavefront, thus significantly enhancing the
resolution of the tightly-focused optical wave. The formation of a light tongue
with dimensions approaching those of the concave opening is here evidenced.
This scheme is expected to have potential applications in optical trapping and
detection.


title:
Efficient tensor completion for color image and video recovery: Low-rank
  tensor train

abstract:
  This paper proposes a novel approach to tensor completion, which recovers
missing entries of data represented by tensors. The approach is based on the
tensor train (TT) rank, which is able to capture hidden information from
tensors thanks to its definition from a well-balanced matricization scheme.
Accordingly, new optimization formulations for tensor completion are proposed
as well as two new algorithms for their solution. The first one called simple
low-rank tensor completion via tensor train (SiLRTC-TT) is intimately related
to minimizing a nuclear norm based on TT rank. The second one is from a
multilinear matrix factorization model to approximate the TT rank of a tensor,
and is called tensor completion by parallel matrix factorization via tensor
train (TMac-TT). A tensor augmentation scheme of transforming a low-order
tensor to higher-orders is also proposed to enhance the effectiveness of
SiLRTC-TT and TMac-TT. Simulation results for color image and video recovery
show the clear advantage of our method over all other methods.