title:
New spectroscopic binary companions of giant stars and updated
  metallicity distribution for binary systems

abstract:
  We report the discovery of 24 spectroscopic binary companions to giant stars.
We fully constrain the orbital solution for 6 of these systems. We cannot
unambiguously derive the orbital elements for the remaining stars because the
phase coverage is incomplete. Of these stars, 6 present radial velocity trends
that are compatible with long-period brown dwarf companions.The orbital
solutions of the 24 binary systems indicate that these giant binary systems
have a wide range in orbital periods, eccentricities, and companion masses. For
the binaries with restricted orbital solutions, we find a range of orbital
periods of between $\sim$ 97-1600 days and eccentricities of between $\sim$
0.1-0.4. In addition, we studied the metallicity distribution of single and
binary giant stars. We computed the metallicity of a total of 395 evolved
stars, 59 of wich are in binary systems. We find a flat distribution for these
binary stars and therefore conclude that stellar binary systems, and
potentially brown dwarfs, have a different formation mechanism than
planets.This result is confirmed by recent works showing that extrasolar
planets orbiting giants are more frequent around metal-rich stars. Finally, we
investigate the eccentricity as a function of the orbital period. We analyzed a
total of 130 spectroscopic binaries, including those presented here and systems
from the literature. We find that most of the binary stars with periods
$\lesssim$ 30 days have circular orbits, while at longer orbital periods we
observe a wide spread in their eccentricities.


title: Interference Power Bound Analysis of a Network of Wireless Robots

abstract:
  We consider a fundamental problem concerning the deployment of a wireless
robotic network: to fulfill various end-to-end performance requirements, a
"sufficient" number of robotic relays must be deployed to ensure that links are
of acceptable quality. Prior work has not addressed how to find this number. We
use the properties of Carrier Sense Multiple Access (CSMA) based wireless
communication to derive an upper bound on the spacing between any
transmitter-receiver pair, which directly translates to a lower bound on the
number of robots to deploy. We focus on SINR-based performance requirements due
to their wide applicability. Next, we show that the bound can be improved by
exploiting the geometrical structure of a network, such as linearity in the
case of flow-based robotic router networks. Furthermore, we also use the bound
on robot count to formulate a lower bound on the number of orthogonal codes
required for a high probability of interference free communication. We
demonstrate and validate our proposed bounds through simulations.


title: Vicious Circle Principle and Formation of Sets in ASP Based Languages

abstract:
  The paper continues the investigation of Poincare and Russel's Vicious Circle
Principle (VCP) in the context of the design of logic programming languages
with sets. We expand previously introduced language Alog with aggregates by
allowing infinite sets and several additional set related constructs useful for
knowledge representation and teaching. In addition, we propose an alternative
formalization of the original VCP and incorporate it into the semantics of new
language, Slog+, which allows more liberal construction of sets and their use
in programming rules. We show that, for programs without disjunction and
infinite sets, the formal semantics of aggregates in Slog+ coincides with that
of several other known languages. Their intuitive and formal semantics,
however, are based on quite different ideas and seem to be more involved than
that of Slog+.


title: TASEP on a ring in sub-relaxation time scale

abstract:
  Interacting particle systems in the KPZ universality class on a ring of size
$L$ with $O(L)$ number of particles are expected to change from KPZ dynamics to
equilibrium dynamics at the so-called relaxation time scale $t=O(L^{3/2})$. In
particular the system size is expected to have little effect to the particle
fluctuations in the sub-relaxation time scale $t\ll L^{3/2}$. We prove that
this is indeed the case for the totally asymmetric simple exclusion process
(TASEP) with two types of initial conditions. For flat initial condition, we
show that the particle fluctuations are given by the Airy$_1$ process as in the
infinite TASEP with flat initial condition. On the other hand, the TASEP on a
ring with step initial condition is equivalent to the periodic TASEP with a
certain shock initial condition. We compute the fluctuations explicitly both
away from and near the shocks for the infinite TASEP with same initial
condition, and then show that the periodic TASEP has same fluctuations in the
sub-relaxation time scale.


title:
Asymmetric soliton mobility in competing linear-nonlinear PT-symmetric
  lattices

abstract:
  We address the transverse mobility of spatial solitons in competing
parity-time-symmetric linear and nonlinear lattices. The competition between
out-of-phase linear and nonlinear lattices results in a drastic mobility
enhancement within a range of soliton energies. We show that within such range,
the addition of even a small imaginary part in the linear potential makes
soliton mobility strongly asymmetric. The minimal phase tilt required for
setting solitons into radiationless motion across the lattice in the direction
opposite to that of the internal current drops to nearly zero, while the
minimal phase tilt required for motion in the opposite direction notably
increases. For a given initial phase tilt, the velocity of soliton motion grows
with an increase of the balanced gain/losses. In this regime of enhanced
mobility, tilted solitons can efficiently drag other solitons that were
initially at rest, to form moving soliton pairs.


title: About Learning in Recurrent Bistable Gradient Networks

abstract:
  Recurrent Bistable Gradient Networks are attractor based neural networks
characterized by bistable dynamics of each single neuron. Coupled together
using linear interaction determined by the interconnection weights, these
networks do not suffer from spurious states or very limited capacity anymore.
Vladimir Chinarov and Michael Menzinger, who invented these networks, trained
them using Hebb's learning rule. We show, that this way of computing the
weights leads to unwanted behaviour and limitations of the networks
capabilities. Furthermore we evince, that using the first order of Hintons
Contrastive Divergence algorithm leads to a quite promising recurrent neural
network. These findings are tested by learning images of the MNIST database for
handwritten numbers.


title: Visualizing and Understanding Sum-Product Networks

abstract:
  Sum-Product Networks (SPNs) are recently introduced deep tractable
probabilistic models by which several kinds of inference queries can be
answered exactly and in a tractable time. Up to now, they have been largely
used as black box density estimators, assessed only by comparing their
likelihood scores only. In this paper we explore and exploit the inner
representations learned by SPNs. We do this with a threefold aim: first we want
to get a better understanding of the inner workings of SPNs; secondly, we seek
additional ways to evaluate one SPN model and compare it against other
probabilistic models, providing diagnostic tools to practitioners; lastly, we
want to empirically evaluate how good and meaningful the extracted
representations are, as in a classic Representation Learning framework. In
order to do so we revise their interpretation as deep neural networks and we
propose to exploit several visualization techniques on their node activations
and network outputs under different types of inference queries. To investigate
these models as feature extractors, we plug some SPNs, learned in a greedy
unsupervised fashion on image datasets, in supervised classification learning
tasks. We extract several embedding types from node activations by filtering
nodes by their type, by their associated feature abstraction level and by their
scope. In a thorough empirical comparison we prove them to be competitive
against those generated from popular feature extractors as Restricted Boltzmann
Machines. Finally, we investigate embeddings generated from random
probabilistic marginal queries as means to compare other tractable
probabilistic models on a common ground, extending our experiments to Mixtures
of Trees.


title: Learning and Inferring Relations in Cortical Networks

abstract:
  A pressing scientific challenge is to understand how brains work. Of
particular interest is the neocortex,the part of the brain that is especially
large in humans, capable of handling a wide variety of tasks including visual,
auditory, language, motor, and abstract processing. These functionalities are
processed in different self-organized regions of the neocortical sheet, and yet
the anatomical structure carrying out the processing is relatively uniform
across the sheet. We are at a loss to explain, simulate, or understand such a
multi-functional homogeneous sheet-like computational structure - we do not
have computational models which work in this way. Here we present an important
step towards developing such models: we show how uniform modules of excitatory
and inhibitory neurons can be connected bidirectionally in a network that, when
exposed to input in the form of population codes, learns the input encodings as
well as the relationships between the inputs. STDP learning rules lead the
modules to self-organize into a relational network, which is able to infer
missing inputs,restore noisy signals, decide between conflicting inputs, and
combine cues to improve estimates. These networks show that it is possible for
a homogeneous network of spiking units to self-organize so as to provide
meaningful processing of its inputs. If such networks can be scaled up, they
could provide an initial computational model relevant to the large scale
anatomy of the neocortex.


title: On the Market-Neutrality of Optimal Pairs-Trading Strategies

abstract:
  We consider the problem of optimal investment in a market with two
cointegrated stocks and an agent with CRRA utility. We extend the findings of
Liu and Timmermann [The Review of Financial Studies, 26(4):1048-1086, 2013] by
paying special attention to when/if the associated stochastic control problem
is well-posed and providing a verification result. Our new findings lead to a
sharp well-posedness condition which is, surprisingly, also the necessary and
sufficient condition for the optimal investment to be market-neutral (i.e.
having offsetting long/short positions in the stocks). Hence, we provide a
theoretical justification for market-neutral pairs-trading which, despite
having a strong practical relevance, has been lacking a theoretical ground.


title:
Lattice statistical models for the nematic transitions in
  liquid-crystalline systems

abstract:
  We investigate the connections between some simple Maier-Saupe lattice
models, with a discrete choice of orientations of the microscopic directors,
and a recent proposal of a two-tensor formalism to describe the phase diagrams
of nematic liquid-crystalline systems. This two-tensor proposal is used to
formulate the statistical problem in terms of fully-connected lattice
Hamiltonians, with the local nematic directors restricted to the Cartesian
axes. Depending on the choice of interaction parameters, we regain all of the
main features of the original mean-field two-tensor calculations. With a
standard choice of parameters, we obtain the well-known sequence of isotropic,
uniaxial, and biaxial nematic structures, with a Landau multicritical point.
With another suitably chosen set of parameters, we obtain two tricritical
points, according to some recent predictions of the two-tensor calculations.
The simple statistical lattice models are quite easy to work with, for all
values of parameters, and the present calculations can be carried out beyond
the mean-field level.


title: Multiplicative functions commutable with sums of squares

abstract:
  Let $k$ be an integer greater than or equal $4$. We show that if a
multiplicative function $f$ satisfies \[ f(x_1^2 + x_2^2 + \dots + x_k^2) =
f(x_1)^2 + f(x_2)^2 + \dots + f(x_k)^2 \] for all positive integers $x_i$'s,
then $f$ is the identity function.


title: On the geometry of regular icosahedral capsids containing disymmetrons

abstract:
  Icosahedral virus capsids are composed of symmetrons, organized arrangements
of capsomers. There are three types of symmetrons: disymmetrons, trisymmetrons,
and pentasymmetrons, which have different shapes and are centered on the
icosahedral 2-fold, 3-fold and 5-fold axes of symmetry, respectively. In 2010
[Sinkovits & Baker] gave a classification of all possible ways of building an
icosahedral structure solely from trisymmetrons and pentasymmetrons, which
requires the triangulation number T to be odd. In the present paper we
incorporate disymmetrons to obtain a geometric classification of icosahedral
viruses formed by regular penta-, tri-, and disymmetrons. For every class of
solutions, we further provide formulas for symmetron sizes and parity
restrictions on h, k, and T numbers. We also present several methods in which
invariants may be used to classify a given configuration.


title: The Expectation Value of S(1).S(2)-Wave Functions Don't Matter

abstract:
  We consider the expectation value of the quantity [3+ \sigma (1).\sigma
(2)]/4 . This has a value +1 for 2 nucleons with spin S=1and zero for S=0. We
show that for the jj coupling 2 particle configuration [j(1) j(2)]^{J} the
expectation value has the structure A+B J(J+1) where A and B are constants. We
then show that for a 2proton-2neutron configuration with total angular momentum
I the expectation value per pair is independent of the details of the wave
function and has a similar structure A' +B' I(I+1) with B'=B/6.


title: Highest Weights for Categorical Representations

abstract:
  We present a criterion for establishing Morita equivalence of monoidal
categories, and apply it to the categorical representation theory of reductive
groups $G$. We show that the "de Rham group algebra" $\mathcal D(G)$ (the
monoidal category of $\mathcal D$-modules on $G$) is Morita equivalent to the
universal Hecke category $\mathcal D(N \backslash G/N)$ and to its monodromic
variant $\widetilde{\mathcal D}(B \backslash G / B)$. In other words, de Rham
$G$-categories, i.e., module categories for $\mathcal D(G)$, satisfy a "highest
weight theorem" - they all appear in the decomposition of the universal
principal series representation $\mathcal D(G/N)$ or in twisted $\mathcal
D$-modules on the flag variety $\widetilde{\mathcal D}(G/B)$


title:
Unitary evolution of a pair of Unruh-DeWitt detectors calculated
  efficiently to an arbitrary perturbative order

abstract:
  Unruh-DeWitt Hamiltonian couples a scalar field with a two-level atom serving
as a particle detector model. Two such detectors held by different observers
following general trajectories can be used to study entanglement behavior in
quantum field theory. Lacking other methods, the unitary evolution must be
studied perturbatively which is considerably time-consuming even to a low
perturbative order. Here we completely solve the problem and present a simple
algorithm for a perturbative calculation based on a solution of a system of
linear Diophantine equations. The algorithm runs polynomially with the
perturbative order. This should be contrasted with the number of perturbative
contributions of the scalar phi^4 theory that is known to grow factorially.
  Speaking of the phi^4 model, a welcome collateral result is obtained to
mechanically (almost mindlessly) calculate the interacting scalar phi^n theory
without resorting to Feynman diagrams. We demonstrate it on a typical textbook
example of two interacting fields for n=3,4.


title: Linear and nonlinear dynamics of isospectral granular chains

abstract:
  We study the dynamics of isospectral granular chains that are highly tunable
due to the nonlinear Hertz contact law interaction between the granular
particles. The system dynamics can thus be tuned easily from being linear to
strongly nonlinear by adjusting the initial compression applied to the chain.
In particular, we introduce both discrete and continuous spectral
transformation schemes to generate a family of granular chains that are
isospectral in their linear limit. Inspired by the principle of supersymmetry
in quantum systems, we also introduce a methodology to add or remove certain
eigenfrequencies, and we demonstrate numerically that the corresponding
physical system can be constructed in the setting of one-dimensional granular
crystals. In the linear regime, we highlight the commonalities and differences
in the elastic wave transmission characteristics of such isospectral systems,
and emphasize that the presented mathematical framework allows one to suitably
tailor the wave transmission through a general class of granular chains.
Moreover, we show how the dynamic response of these structures deviates from
its linear limit as we introduce Hertzian nonlinearity in the chain and how
nonlinearity breaks the notion of linear isospectrality.


title: Van der Waals universality in homonuclear atom-dimer elastic collisions

abstract:
  The universal aspects of atom-dimer elastic collisions are investigated
within the framework of Faddeev equations. The two-body interactions between
the neutral atoms are approximated by the separable potential approach. Our
analysis considers a pure van der Waals potential tail as well as soft-core van
der Waals interactions permitting us in this manner to address the universally
general features of atom-dimer resonant spectra. In particular, we show that
the atom-dimer resonances are solely associated with the {\it excited} Efimov
states. Furthermore, the positions of the corresponding resonances for a
soft-core potentials with more than 5 bound states are in good agreement with
the corresponding results from an infinitely deep pure van der Waals tail
potential.


title: Self-Interacting Dark Matter with Naturally Light Mediator

abstract:
  A promising proposal for resolving the cusp-core anomaly in the density
profile of dwarf galaxies is to allow dark matter to interact with itself
through a light mediator of mass much less than a GeV. The theoretical
challenge is to have a complete renormalizable theory where this happens
naturally even though dark matter itself may be of the electroweak scale, i.e.
100 GeV to 1 TeV. I propose here such a model, with just two neutral complex
scalar singlets under a softly broken dark global U(1) symmetry.


title:
Optimal Deployment of Resources for Maximizing Impact in Spreading
  Processes

abstract:
  The effective use of limited resources for controlling spreading processes on
networks is of prime significance in diverse contexts, ranging from the
identification of "influential spreaders" for maximizing information
dissemination and targeted interventions in regulatory networks, to the
development of mitigation policies for infectious diseases and financial
contagion in economic systems. Solutions for these optimization tasks that are
based purely on topological arguments are not fully satisfactory; in realistic
settings the problem is often characterized by heterogeneous interactions and
requires interventions over a finite time window via a restricted set of
controllable nodes. The optimal distribution of available resources hence
results from an interplay between network topology and spreading dynamics. We
show how these problems can be addressed as particular instances of a universal
analytical framework based on a scalable dynamic message-passing approach and
demonstrate the efficacy of the method on a variety of real-world examples.


title:
Thermal and Tensile Strength Testing of Thermally-Conductive Adhesives
  and Carbon Foam

abstract:
  Future collider detectors, including silicon tracking detectors planned for
the High Luminosity LHC, will require components and mechanical structures
providing unprecedented strength-to-mass ratios, thermal conductivity, and
radiation tolerance. This paper studies carbon foam used in conjunction with
thermally conductive epoxy and thermally conductive tape for such applications.
Thermal performance and tensile strength measurements of aluminum-carbon
foam-adhesive stacks are reported, along with initial radiation damage test
results.


title: Confinement effects on the properties of Janus dimers

abstract:
  Confinement has been suggested as a tool to tune the self-assembly properties
of nanoparticles, surfactants, polymers and colloids. In this way, we explore
the phase diagram of Janus nanoparticles using Molecular Dynamics simulations.
The nanoparticle was modeled as a dimer made by one monomer that interacts by a
standard Lennard Jones potential and another monomer that is modeled using a
two-length scale shoulder potential. This specific design of nanoparticle
exhibits in bulk distinct self-assembled structures and water-like diffusion
anomaly. Our results indicate that besides the aggregates observed in bulk, new
structures are observed under confinement. Also, the dynamic and thermodynamic
behavior of the fluid phase are affected. The systems show a reentrant fluid
phase and density anomaly. None of these two features were observed in bulk.
Our results show that geometrical confinement leads to new structural,
thermodynamical and dynamical behavior for this Janus nanoparticle.


title:
Soliton pulse propagation in the presence of disorder-induced multiple
  scattering in photonic crystal waveguides

abstract:
  We introduce a new coupled mode theory to model nonlinear Schr\"odinger
equations for contra- propagating Bloch modes that include disorder-induced
multiple scattering effects on nonlinear soliton propagation in photonic
crystal waveguides. We also derive sub unit-cell coupling coefficients and use
these to introduce a generalized length scale associated with each coupling
effect. In particular, we define a multiple-scattering length scale that
quantifies the spatial extent of a disorder- induced cavity mode. Our numerical
simulations of nonlinear pulse propagation are in excellent qualitative
agreement with recent experiments and provide insight into how disorder
inhibits soliton propagation and other nonlinear propagation effects in
photonic crystal waveguides.


title: Infinite-Dimensional Triangularization

abstract:
  The goal of this paper is to generalize the theory of triangularizing
matrices to linear transformations of an arbitrary vector space, without
placing any restrictions on the dimension of the space or on the base field. We
define a transformation T of a vector space V to be "triangularizable" if V has
a well-ordered basis such that T sends each vector in that basis to the
subspace spanned by basis vectors no greater than it. We then show that the
following conditions (among others) are equivalent: (1) T is triangularizable,
(2) every finite-dimensional subspace of V is annihilated by f(T) for some
polynomial f that factors into linear terms, (3) there is a maximal
well-ordered set of subspaces of V that are invariant under T, (4) T can be put
into a crude version of the Jordan canonical form. We also show that any finite
collection of commuting triangularizable transformations is simultaneously
triangularizable, we describe the closure of the set of triangularizable
transformations in the standard topology on the algebra of all transformations
of V , and we extend to transformations that satisfy a polynomial the classical
fact that the double-centralizer of a matrix is the algebra generated by that
matrix.


title: Risk measures and Margining control

abstract:
  This document constitutes the final report of the contractual activity
between Directa SIM and Dipartimento di Automatica e Informatica, Politecnico
di Torino, on the research topic titled "quantificazione del rischio di un
portafoglio di strumenti finanziari per trading online su device fissi e
mobili."


title:
Study of galaxies in the Lynx-Cancer void. VI. HI-observations with the
  Nancay Radio Telescope

abstract:
  Context. Void population consists mainly of late-type and low surface
brightness (LSB) dwarf galaxies whose atomic hydrogen is the main component of
their baryonic matter. Therefore, observations of void galaxy HI are mandatory
in order to understand their evolution and dynamics.
  Aims. Our aim was to obtain integrated HI parameters for a fainter part of
the nearby Lynx-Cancer void galaxy sample (total of 45 objects) with the Nancay
Radio Telescope (NRT) and to conduct the comparative analysis of all the 103
void galaxies with known HI data with a sample of similar galaxies residing in
denser environments of the Local Volume.
  Methods. For HI observations we used the NRT with its sensitive
antenna/receiver system FORT and standard processing. The comparison of the
void and control samples on the parameter M(HI)/L_B is conducted with the
non-parametric method `The 2x2 Contingency Table test'.
  Results. We obtained new HI data for about 40% of the Lynx-Cancer galaxy
sample. Along with data from the literature, we use these new data for further
analysis of 103 void objects. The proxy of the evolutional parameter M(HI)/L_B
of the void sample is compared with that of 82 galaxies of morphological types
8--10 residing in the Local Volume (LV) groups and aggregates.
  Conclusions. At the confidence level of P = 0.988, we conclude that for the
same luminosity, these void galaxies are systematically gas-richer, on average
by ~39%. This result is consistent with the authors' earlier conclusion on the
smaller gas metallicities and evidence for the slower low-mass galaxy evolution
in voids.


title: Integrating multiple random sketches for singular value decomposition

abstract:
  The singular value decomposition (SVD) of large-scale matrices is a key tool
in data analytics and scientific computing. The rapid growth in the size of
matrices further increases the need for developing efficient large-scale SVD
algorithms. Randomized SVD based on one-time sketching has been studied, and
its potential has been demonstrated for computing a low-rank SVD. Instead of
exploring different single random sketching techniques, we propose a Monte
Carlo type integrated SVD algorithm based on multiple random sketches. The
proposed integration algorithm takes multiple random sketches and then
integrates the results obtained from the multiple sketched subspaces. So that
the integrated SVD can achieve higher accuracy and lower stochastic variations.
The main component of the integration is an optimization problem with a matrix
Stiefel manifold constraint. The optimization problem is solved using
Kolmogorov-Nagumo-type averages. Our theoretical analyses show that the
singular vectors can be induced by population averaging and ensure the
consistencies between the computed and true subspaces and singular vectors.
Statistical analysis further proves a strong Law of Large Numbers and gives a
rate of convergence by the Central Limit Theorem. Preliminary numerical results
suggest that the proposed integrated SVD algorithm is promising.


title:
Free-energy barrier of filling a spherical cavity in the presence of
  line tension: Implication to the energy barrier between the Cassie and Wenzel
  state on a superhydrophobic surface with spherical cavities

abstract:
  The free-energy barrier of filling a spherical cavity having an inner wall of
various wettabiities is studied. The morphology and free energy of a
lens-shaped droplet are determined from the minimum of the free energy. The
effect of line tension on the free energy is also studied. Then, the
equilibrium contact angle of the droplet is determined from the generalized
Young's equation. By increasing the droplet volume within the spherical cavity,
the droplet morphology changes from spherical with an equilibrium contact angle
of $180^{\circ}$ to a lens with a convex meniscus, where the morphological
complete drying transition occurs. By further increasing the droplet volume,
the meniscus changes from convex to concave. Then, the lens-shaped droplet with
concave meniscus spreads over the whole inner wall resulting in an equilibrium
contact angle of $0^{\circ}$ to leave a spherical bubble, where the
morphological complete wetting transition occurs. Finally, the whole cavity is
filled with liquid. The free energy shows a barrier from complete drying to
complete wetting as a function of droplet volume, which corresponds to the
energy barrier between the Cassie and Wenzel state of the superhydrophobic
surface with spherical cavities. The free-energy maximum occurs when the
meniscus of the droplet becomes flat and it is given by an analytic formula.
The effect of line tension is expressed by the scaled line tension, and this
effect is largest at the free-energy maximum. The positive line tension
increases the free-energy maximum, which thus, increases the stability of the
Cassie superhydrophobic state, whereas the negative line tension destabilizes
the superhydrophobic state.


title: Modified Double Poisson Brackets

abstract:
  We propose a non skew-symmetric generalization of the original definition of
double Poisson Bracket by M. Van den Bergh. It allows one to explicitly
construct more general class of H0-Poisson structures on finitely generated
associative algebras. We show that modified double Poisson brackets inherit
certain major properties of the double Poisson brackets.


title: The m=1 amplituhedron and cyclic hyperplane arrangements

abstract:
  The (tree) amplituhedron A(n,k,m) is the image in the Grassmannian Gr(k,k+m)
of the totally nonnegative part of Gr(k,n), under a (map induced by a) linear
map which is totally positive. It was introduced by Arkani-Hamed and Trnka in
2013 in order to give a geometric basis for the computation of scattering
amplitudes in N=4 supersymmetric Yang-Mills theory. When k+m=n, the
amplituhedron is isomorphic to the totally nonnegative Grassmannian, and when
k=1, the amplituhedron is a cyclic polytope. While the case m=4 is most
relevant to physics, the amplituhedron is an interesting mathematical object
for any m. In this paper we study it in the case m=1. We start by taking an
orthogonal point of view and define a related "B-amplituhedron" B(n,k,m), which
we show is isomorphic to A(n,k,m). We use this reformulation to describe the
amplituhedron in terms of sign variation. We then give a cell decomposition of
the amplituhedron A(n,k,1) using the images of a collection of distinguished
cells of the totally nonnegative Grassmannian. We also show that A(n,k,1) can
be identified with the complex of bounded faces of a cyclic hyperplane
arrangement, and describe how its cells fit together. We deduce that A(n,k,1)
is homeomorphic to a ball.


title:
M\"{o}bius disjointness for topological models of ergodic systems with
  discrete spectrum

abstract:
  We provide a criterion for a point satisfying the required disjointness
condition in Sarnak's M\"obius Disjointness Conjecture. As a direct
application, we have that the conjecture holds for any topological model of an
ergodic system with discrete spectrum.


title: Whitney equisingularity of families of surfaces in $\mathbb{C}^3$

abstract:
  In this work, we study families of singular surfaces in $\mathbb{C}^3$
parametrized by $\mathcal{A}$-finitely determined map germs. We consider the
topological triviality and Whitney equisingularity of an unfolding $F$ of a
finitely determined map germ $f:(\mathbb{C}^2,0)\rightarrow(\mathbb{C}^3,0)$.
We investigate the following conjecture: topological triviality implies Whitney
equisingularity of the unfolding $F$? We provide a complete answer to this
conjecture, given counterexamples showing how the conjecture can be false.


title: Gaussian Process Models for Mortality Rates and Improvement Factors

abstract:
  We develop a Gaussian process ("GP") framework for modeling mortality rates
and mortality improvement factors. GP regression is a nonparametric,
data-driven approach for determining the spatial dependence in mortality rates
and jointly smoothing raw rates across dimensions, such as calendar year and
age. The GP model quantifies uncertainty associated with smoothed historical
experience and generates full stochastic trajectories for out-of-sample
forecasts. Our framework is well suited for updating projections when newly
available data arrives, and for dealing with "edge" issues where credibility is
lower. We present a detailed analysis of Gaussian process model performance for
US mortality experience based on the CDC datasets. We investigate the
interaction between mean and residual modeling, Bayesian and non-Bayesian GP
methodologies, accuracy of in-sample and out-of-sample forecasting, and
stability of model parameters. We also document the general decline, along with
strong age-dependency, in mortality improvement factors over the past few
years, contrasting our findings with the Society of Actuaries ("SOA") MP-2014
and -2015 models that do not fully reflect these recent trends.


title:
Robust Energy Storage Scheduling for Imbalance Reduction of
  Strategically Formed Energy Balancing Groups

abstract:
  Imbalance (on-line energy gap between contracted supply and actual demand,
and associated cost) reduction is going to be a crucial service for a Power
Producer and Supplier (PPS) in the deregulated energy market. PPS requires
forward market interactions to procure energy as precisely as possible in order
to reduce imbalance energy. This paper presents, 1) (off-line) an effective
demand aggregation based strategy for creating a number of balancing groups
that leads to higher predictability of group-wise aggregated demand, 2)
(on-line) a robust energy storage scheduling that minimizes the imbalance for a
particular balancing group considering the demand prediction uncertainty. The
group formation is performed by a Probabilistic Programming approach using
Bayesian Markov Chain Monte Carlo (MCMC) method after applied on the historical
demand statistics. Apart from the group formation, the aggregation strategy
(with the help of Bayesian Inference) also clears out the upper-limit of the
required storage capacity for a formed group, fraction of which is to be
utilized in on-line operation. For on-line operation, a robust energy storage
scheduling method is proposed that minimizes expected imbalance energy and cost
(a non-linear function of imbalance energy) while incorporating the demand
uncertainty of a particular group. The proposed methods are applied on the real
apartment buildings' demand data in Tokyo, Japan. Simulation results are
presented to verify the effectiveness of the proposed methods.


title:
Measurement of the transfer function for a spoke cavity of C-ADS
  Injector I

abstract:
  The spoke cavities mounted in the China Accelerator Driven sub-critical
System (C-ADS) have high quality factor(Q) and very small bandwidth, making
them very sensitive to mechanical perturbations whether external or
self-induced. The transfer function is used to characterize the response of the
cavity eigen frequency to the perturbations. This paper describes a method to
measure the transfer function of a spoke cavity. The measured Lorentz transfer
function shows there are 206 Hz and 311 Hz mechanical eigenmodes excited by
Lorentz force in the cavity of C-ADS, and the measured piezo fast tuner
transfer function shows there are 12 mechanical eigenmodes from 0 to 500 Hz.
According to these results, some effective measures have been taken to weaken
the influence from helium pressure fluctuation, avoid mechanical resonances and
improve the reliability of RF system.


title:
Gutzwiller's Semiclassical Trace Formula and Maslov-Type Index Theory
  for Symplectic Paths

abstract:
  Gutzwiller's famous semiclassical trace formula plays an important role in
theoretical and experimental quantum mechanics with tremendous success. We
review the physical derivation of this deep periodic orbit theory in terms of
the phase space formulation with an view towards the Hamiltonian dynamical
systems. The Maslov phase appearing in the trace formula is clarified by
Meinrenken as Conley-Zhender index for periodic orbits of Hamiltonian systems.
We also survey and compare various versions of Maslov indices to establish this
fact. A refinement and improvement to Conley-Zehnder's index theory which we
will recall all essential ingredients is the Maslov-type index theory for
symplectic paths developed by Long and his collaborators which would shed new
light on the computations and understandings on the semiclassical trace
formula. The insights in Gutzwiller's work also seems plausible to the studies
on Hamiltonian systems.

categories: math.DS math.SG math.SP nlin.CD quant-ph


title: Generalized torsion elements and bi-orderability of 3-manifold groups

abstract:
  It is known that a bi-orderable group has no generalized torsion element, but
the converse does not hold in general. We conjecture that the converse holds
for the fundamental groups of 3-manifolds, and verify the conjecture for
non-hyperbolic, geometric 3-manifolds. We also confirm the conjecture for some
infinite families of closed hyperbolic 3-manifolds. In the course of the proof,
we prove that each standard generator of the Fibonacci group F(2,m) (m>2) is a
generalized torsion element.


title: Hurwitz Number Fields

abstract:
  The canonical covering maps from Hurwitz varieties to configuration varieties
are important in algebraic geometry. The scheme-theoretic fiber above a
rational point is commonly connected, in which case it is the spectrum of a
Hurwitz number field. We study many examples of such maps and their fibers,
finding number fields whose existence contradicts standard mass heuristics.


title: On the metallicity distribution of the peculiar globular cluster M22

abstract:
  In our previous study, we showed that the peculiar globular cluster (GC) M22
contains two distinct stellar populations, namely the Ca-w and Ca-s groups with
different physical properties, having different chemical compositions, spatial
distributions and kinematics. We proposed that M22 is most likely formed via a
merger of two GCs with heterogeneous metallicities in a dwarf galaxy
environment and accreted later to our Galaxy. In their recent study,
Mucciarelli et al. claimed that M22 is a normal mono-metallic globular cluster
without any perceptible metallicity spread among the two groups of stars, which
challenges our results and those of others. We devise new strategies for the
local thermodynamic equilibrium (LTE) abundance analysis of red giant branch
(RGB) stars in GCs and show there exists a spread in the iron abundance
distribution in M22.


title: Neutrino Masses, Scale-Dependent Growth, and Redshift-Space Distortions

abstract:
  Massive neutrinos leave a unique signature in the large scale clustering of
matter. We investigate the wavenumber dependence of the growth factor arising
from neutrino masses and use a Fisher analysis to determine the aspects of a
galaxy survey needed to measure this scale dependence.


title:
Spectral cluster bounds for orthonormal systems and oscillatory integral
  operators in Schatten spaces

abstract:
  We generalize the $L^p$ spectral cluster bounds of Sogge for the
Laplace-Beltrami operator on compact Riemannian manifolds to systems of
orthonormal functions. The optimality of these new bounds is also discussed.
These spectral cluster bounds follow from Schatten-type bounds on oscillatory
integral operators.


title:
Experimental fast quantum random number generation using
  high-dimensional entanglement with entropy monitoring

abstract:
  A quantum random number generator (QRNG) generates genuine randomness from
the intrinsic probabilistic nature of quantum mechanics. The central problems
for most QRNGs are estimating the entropy of the genuine randomness and
producing such randomness at high rates. Here we propose and demonstrate a
proof-of-concept QRNG that operates at a high rate of 24 Mbit/s by means of a
high-dimensional entanglement system, in which the user monitors the entropy in
real time via the observation of a nonlocal quantum interference, without a
detailed characterization of the devices. Our work provides an important
approach to a robust QRNG with trusted but error-prone devices.


title: A Proof of Onsager's Conjecture

abstract:
  For any $\alpha < 1/3$, we construct weak solutions to the $3D$
incompressible Euler equations in the class $C_tC_x^\alpha$ that have nonempty,
compact support in time on ${\mathbb R} \times {\mathbb T}^3$ and therefore
fail to conserve the total kinetic energy. This result, together with the proof
of energy conservation for $\alpha > 1/3$ due to [Eyink] and [Constantin, E,
Titi], solves Onsager's conjecture that the exponent $\alpha = 1/3$ marks the
threshold for conservation of energy for weak solutions in the class
$L_t^\infty C_x^\alpha$. The previous best results were solutions in the class
$C_tC_x^\alpha$ for $\alpha < 1/5$, due to the author, and in the class $L_t^1
C_x^\alpha$ for $\alpha < 1/3$ due to Buckmaster, De Lellis and
Sz\'{e}kelyhidi, both based on the method of convex integration developed for
the incompressible Euler equations by De Lellis and Sz\'ekelyhidi. The present
proof combines the method of convex integration and a new "gluing
approximation" technique. The convex integration part of the proof relies on
the "Mikado flows" introduced by [Daneri, Sz\'ekelyhidi] and the framework of
estimates developed in the author's previous work.


title: Hurwitz-Belyi Maps

abstract:
  The study of the moduli of covers of the projective line leads to the theory
of Hurwitz varieties covering configuration varieties. Certain one-dimensional
slices of these coverings are particularly interesting Belyi maps. We present
systematic examples of such "Hurwitz-Belyi maps." Our examples illustrate a
wide variety of theoretical phenomena and computational techniques.


title:
Wigner spectrum and coherent feedback control of continuous-mode
  single-photon Fock states

abstract:
  Single photons are very useful resources in quantum information science. In
real applications it is often required that the photons have a well-defined
spectral (or equivalently temporal) modal structure. For example, a rising
exponential pulse is able to fully excite a two-level atom while a Gaussian
pulse cannot. This motivates the study of continuous-mode single-photon Fock
states. Such states are characterized by a spectral (or temporal) pulse shape.
In this paper we investigate the statistical property of continuous-mode
single-photon Fock states. Instead of the commonly used normal ordering (Wick
order), the tool we proposed is the Wigner spectrum. The Wigner spectrum has
two advantages: 1) it allows to study continuous-mode single-photon Fock states
in the time domain and frequency domain simultaneously; 2) because it can deal
with the Dirac delta function directly, it has the potential to provide more
information than the normal ordering where the Dirac delta function is always
discarded. We also show how various control methods in particular coherent
feedback control can be used to manipulate the pulse shapes of continuous-mode
single-photon Fock states.


title:
Information-carrying Hawking radiation and the number of microstate for
  a black hole

abstract:
  We present a necessary and sufficient condition to falsify whether a Hawking
radiation spectrum indicates unitary emission process or not from the
perspective of information theory. With this condition, we show the precise
values of Bekenstein-Hawking entropies for Schwarzschild black holes and
Reissner-Nordstr\"om black holes can be calculated by counting the microstates
of their Hawking radiations. In particular, for the extremal
Reissner-Nordstr\"om black hole, its number of microstate and the corresponding
entropy we obtain are found to be consistent with the string theory results.
Our finding helps to refute the dispute about the Bekenstein-Hawking entropy of
extremal black holes in the semiclassical limit.


title:
Utilizing Large Scale Vision and Text Datasets for Image Segmentation
  from Referring Expressions

abstract:
  Image segmentation from referring expressions is a joint vision and language
modeling task, where the input is an image and a textual expression describing
a particular region in the image; and the goal is to localize and segment the
specific image region based on the given expression. One major difficulty to
train such language-based image segmentation systems is the lack of datasets
with joint vision and text annotations. Although existing vision datasets such
as MS COCO provide image captions, there are few datasets with region-level
textual annotations for images, and these are often smaller in scale. In this
paper, we explore how existing large scale vision-only and text-only datasets
can be utilized to train models for image segmentation from referring
expressions. We propose a method to address this problem, and show in
experiments that our method can help this joint vision and language modeling
task with vision-only and text-only data and outperforms previous results.


title:
Machine Learning in Downlink Coordinated Multipoint in Heterogeneous
  Networks

abstract:
  We propose a method for downlink coordinated multipoint (DL CoMP) in
heterogeneous fifth generation New Radio (NR) networks. The primary
contribution of our paper is an algorithm to enhance the trigger of DL CoMP
using online machine learning. We use support vector machine (SVM) classifiers
to enhance the user downlink throughput in a realistic frequency division
duplex network environment. Our simulation results show improvement in both the
macro and pico base station downlink throughputs due to the informed triggering
of the multiple radio streams as learned by the SVM classifier.


title:
Discriminating cosmic muons and radioactivity using a liquid
  scintillation fiber detector

abstract:
  In the case of underground experiments for neutrino physics or rare event
searches, the background caused by cosmic muons contributes significantly and
therefore must be identified and rejected. We proposed and optimized a new
detector using liquid scintillator with wavelenghth-shifting fibers which can
be employed as a veto detector for cosmic muons background rejection. From the
prototype study, it has been found that the detector has good performances and
is capable of discriminating between muons induced signals and environmental
radiation background. Its muons detection efficiency is greater than 98$\%$,
and on average, 58 photo-electrons (p.e.) are collected when a muon passes
through the detector. To optimize the design and enhance the collection of
light, the reflectivity of the coating materials has been studied in detail. A
Monte Carlo simulation of the detector has been developed and compared to the
performed measurements showing a good agreement between data and simulation
results.


title:
Thermalization of oscillator chains with onsite anharmonicity and
  comparison with kinetic theory

abstract:
  We perform microscopic molecular dynamics simulations of particle chains with
an onsite anharmonicity to study relaxation of spatially homogeneous states to
equilibrium, and directly compare the simulations with the corresponding
Boltzmann-Peierls kinetic theory. The Wigner function serves as common
interface between the microscopic and kinetic level. We demonstrate
quantitative agreement after an initial transient time interval. In particular,
besides energy conservation, we observe the additional quasi-conservation of
the phonon density, defined via an ensemble average of the related microscopic
field variables and exactly conserved by the kinetic equations. On
super-kinetic time scales, density quasi-conservation is lost while energy
remains conserved, and we find evidence for eventual relaxation of the density
to its canonical ensemble value. However, the precise mechanism remains unknown
and is not captured by the Boltzmann-Peierls equations.


title: Hyperbolic Dehn filling in dimension four

abstract:
  We introduce and study some deformations of complete finite-volume hyperbolic
four-manifolds that may be interpreted as four-dimensional analogues of
Thurston's hyperbolic Dehn filling.
  We construct in particular an analytic path of complete, finite-volume cone
four-manifolds $M_t$ that interpolates between two hyperbolic four-manifolds
$M_0$ and $M_1$ with the same volume $\frac {8}3\pi^2$. The deformation looks
like the familiar hyperbolic Dehn filling paths that occur in dimension three,
where the cone angle of a core simple closed geodesic varies monotonically from
$0$ to $2\pi$. Here, the singularity of $M_t$ is an immersed geodesic surface
whose cone angles also vary monotonically from $0$ to $2\pi$. When a cone angle
tends to $0$ a small core surface (a torus or Klein bottle) is drilled
producing a new cusp.
  We show that various instances of hyperbolic Dehn fillings may arise,
including one case where a degeneration occurs when the cone angles tend to
$2\pi$, like in the famous figure-eight knot complement example.
  The construction makes an essential use of a family of four-dimensional
deforming hyperbolic polytopes recently discovered by Kerckhoff and Storm.


title:
The influence of chiral chemical potential, parallel electric and
  magnetic fields on the critical temperature of QCD

abstract:
  We study the influence of external electric, $E$, and magnetic, $B$, fields
parallel to each other, and of a chiral chemical potential, $\mu_5$, on the
chiral phase transition of Quantum Chromodynamics. Our theoretical framework is
a Nambu-Jona-Lasinio model with a contact interaction. Within this model we
compute the critical temperature of chiral symmetry restoration, $T_c$, as a
function of the chiral chemical potential and field strengths. We find that the
fields inhibit and $\mu_5$ enhances chiral symmetry breaking, in agreement with
previous studies.


title:
A Characterization of Lyapunov Inequalities for Stability of Switched
  Systems

abstract:
  We study stability criteria for discrete-time switched systems and provide a
meta-theorem that characterizes all Lyapunov theorems of a certain canonical
type. For this purpose, we investigate the structure of sets of LMIs that
provide a sufficient condition for stability. Various such conditions have been
proposed in the literature in the past fifteen years. We prove in this note
that a family of languagetheoretic conditions recently provided by the authors
encapsulates all the possible LMI conditions, thus putting a conclusion to this
research effort. As a corollary, we show that it is PSPACE-complete to
recognize whether a particular set of LMIs implies stability of a switched
system. Finally, we provide a geometric interpretation of these conditions, in
terms of existence of an invariant set.


title:
New concept for pairing anti-halo effect as a localized wave packet of
  quasi-particle

abstract:
  The pairing anti-halo effect is a phenomenon that a pairing correlation
suppresses a divergence of nuclear radius, which happens for single-particle
states with orbital angular momenta of $l$ = 0 and 1 in the limit of vanishing
binding energy. While this effect has mainly been discussed in terms of
Hartree-Fock-Bogoliubov (HFB) theory, we here use a three-body model and
provide its new intuitive concept as a localized wave packet for a
quasi-particle, that is, a coherent superposition of a weakly bound and
continuum wave functions due to a pairing interaction. We show that the
one-particle density in the three-body model can be directly expressed with
such quasi-particle wave functions, which have a close analog to wave functions
in the HFB approximation.


title:
Sub-channel Assignment, Power Allocation and User Scheduling for
  Non-Orthogonal Multiple Access Networks

abstract:
  In this paper, we study the resource allocation and user scheduling problem
for a downlink nonorthogonal multiple access network where the base station
allocates spectrum and power resources to a set of users. We aim to jointly
optimize the sub-channel assignment and power allocation to maximize the
weighted total sum-rate while taking into account user fairness. We formulate
the sub-channel allocation problem as equivalent to a many-to-many two-sided
user-subchannel matching game in which the set of users and sub-channels are
considered as two sets of players pursuing their own interests. We then propose
a matching algorithm which converges to a two-side exchange stable matching
after a limited number of iterations. A joint solution is thus provided to
solve the sub-channel assignment and power allocation problems iteratively.
Simulation results show that the proposed algorithm greatly outperforms the
orthogonal multiple access scheme and a previous non-orthogonal multiple access
scheme.


title: Evolution of natal dispersal in spatially heterogenous environments

abstract:
  Understanding the evolution of dispersal is an important issue in
evolutionary ecology. For continuous time models in which individuals disperse
throughout their lifetime, it has been shown that a balanced dispersal
strategy, which results in an ideal free distribution, is evolutionary stable
in spatially varying but temporally constant environments. Many species,
however, primarily disperse prior to reproduction (natal dispersal) and less
commonly between reproductive events (breeding dispersal). As demographic and
dispersal terms combine in a multiplicative way for models of natal dispersal,
rather than the additive way for the previously studied models, we develop new
mathematical methods to study the evolution of natal dispersal for
continuous-time and discrete-time models. A fundamental ecological dichotomy is
identified for the non-trivial equilibrium of these models: (i) the per-capita
growth rates for individuals in all patches is equal to zero, or (ii)
individuals in some patches experience negative per-capita growth rates, while
individuals in other patches experience positive per-capita growth rates. The
first possibility corresponds to an ideal-free distribution, while the second
possibility corresponds to a "source-sink" spatial structure. We prove that
populations with a dispersal strategy leading to an ideal-free distribution
displace populations with dispersal strategy leading to a source-sink spatial
structure. When there are patches which can not sustain a population,
ideal-free strategies can be achieved by sedentary populations, and we show
that these populations can displace populations with any irreducible dispersal
strategy. Collectively, these results support that evolution selects for natal
or breeding dispersal strategies which lead to ideal-free distributions in
spatially heterogenous, but temporally homogenous, environments.


title:
Direct calculation of the linear thermal expansion coefficients of MoS2
  via symmetry-preserving deformations

abstract:
  Using density-functional perturbation theory and the Gr\"uneisen formalism,
we directly calculate the linear thermal expansion coefficients (TECs) of a
hexagonal bulk system MoS$_2$ in the crystallographic $a$ and $c$ directions.
The TEC calculation depends critically on the evaluation of a
temperature-dependent quantity $I_i(T)$, which is the integral of the product
of heat capacity and $\Gamma_i(\nu)$, of frequency $\nu$ and strain type $i$,
where $\Gamma_i(\nu)$ is the phonon density of states weighted by the
Gr\"uneisen parameters. We show that to determine the linear TECs we may use
minimally two uniaxial strains in the $z$ direction, and either the $x$ or $y$
direction. However, a uniaxial strain in either the $x$ or $y$ direction
drastically reduces the symmetry of the crystal from a hexagonal one to a
base-centered orthorhombic one. We propose to use an efficient and accurate
symmetry-preserving biaxial strain in the $xy$ plane to derive the same result
for $\Gamma(\nu)$. We highlight that the Gr\"uneisen parameter associated with
a biaxial strain may not be the same as the average of Gr\"uneisen parameters
associated with two separate uniaxial strains in the $x$ and $y$ directions due
to possible preservation of degeneracies of the phonon modes under a biaxial
deformation. Large anisotropy of TECs is observed where the linear TEC in the
$c$ direction is about $1.8$ times larger than that in the $a$ or $b$ direction
at high temperatures. Our theoretical TEC results are compared with experiment.
The symmetry-preserving approach adopted here may be applied to a broad class
of two lattice-parameter systems such as hexagonal, trigonal, and tetragonal
systems, which allows many complicated systems to be treated on a
first-principles level.


title: Toward a Zero-Parameter Model for Galaxy Rotation Curve Data

abstract:
  Modeling the luminous mass components of spiral galaxies in standard gravity
poses a challenge due to the missing mass problem. However, with the addition
of cold dark matter, the missing mass problem can be circumvented at the cost
of additional free parameters to the theory. The Luminous Convolution Model
(LCM) reconsiders how we interpret rotation curve data, such that
Doppler-shifted spectra measurements can constrain luminous mass discovery. For
a sample of 25 galaxies of varying morphologies and sizes, we demonstrate an
ansatz for relative galaxy curvatures that can explain the missing mass. We
solve for the LCM free parameter, which we report as a ratio of radial
densities of the emitter, to receiver galaxy baryonic mass, to an exponent of
$1.63$. Here, we show that this exponent is sensitive to which Milky Way
luminous mass model one chooses. We then make a first prediction regarding the
Milky Way mass profile in the inner one kpc.
  Thus, with a bound on the LCM free parameter, we pave the way for future
work, where the LCM will tested as a zero-parameter model to predict luminous
mass from rotation curve data.


title:
$\sigma$-SCF: A Direct Energy-targeting Method To Mean-field Excited
  States

abstract:
  The mean-field solutions of electronic excited states are much less
accessible than ground state (e.g.\ Hartree-Fock) solutions. Energy-based
optimization methods for excited states, like $\Delta$-scf, tend to fall into
the lowest solution consistent with a given symmetry -- a problem known as
"variational collapse". In this work, we combine the ideas of direct
energy-targeting and variance-based optimization in order to describe excited
states at the mean-field level. The resulting method, $\sigma$-scf, has several
advantages. First, it allows one to target any desired excited state by
specifying a single parameter: a guess of the energy of that state. It can
therefore, in principle, find \emph{all} excited states. Second, it avoids
variational collapse by using a variance-based, unconstrained local
minimization. As a consequence, all states -- ground or excited -- are treated
on an equal footing. Third, it provides an alternate approach to locate
$\Delta$-scf solutions that are otherwise inaccessible by the usual non-aufbau
configuration initial guess. We present results for this new method for small
atoms (He, Be) and molecules (H2, HF).


title:
A Note on Choosing the Threshold for Large Covariance Estimations in
  Factor Models

abstract:
  This note shows that for i.i.d. data, estimating large covariance matrices in
factor models can be casted using a simple plug-in method to choose the
threshold: $$
\mu_{jl}=\frac{c_0}{\sqrt{n}}\Phi^{-1}(1-\frac{\alpha}{2p^2})\sqrt{\frac{1}{n}\sum_{i=1}^n\hat
u_{ji}^2\hat u_{li}^2}.$$ This is motivated by the tuning parameter suggested
by Belloni et al. (2012) in the lasso literature. It also leads to the minimax
rate of convergence of the large covariance matrix estimator. Previously, the
minimaxity is achievable only when $n=o(p\log p)$ by Fan et al. (2013), and now
this condition is weakened to $n=o(p^2\log p)$. Here $n$ denotes the sample
size and $p$ denotes the dimension.


title: On the minimal degree of morphisms between algebraic curves

abstract:
  Given smooth, projective, geometrically integral algebraic curves $X$ and $Y$
defined over a number field $K$, assuming that there is a non-constant
$K$-morphism $\varphi \colon X \to Y$, we give an upper bound on the minimum of
the degrees of such morphisms. The proof is based on isogeny estimates between
abelian varieties.


title: When the Cauchy inequality becomes a formula

abstract:
  In this note we revisit the classical geometric-arithmetic mean inequality
and find a formula for the difference of the arithmetic and the geometric means
of given $n\in\mathbb N$ nonnegative numbers $x_1,x_2,\dots,x_n$. The formula
yields new stronger versions of the geometric-arithmetic mean inequality. We
also find a second version of a strong geometric-arithmetic mean inequality and
show that all inequalities are optimal in some sense. Anther striking novelty
is, that the equality in all new inequalities holds not only in the case when
all $n$ numbers are equal, but also in other cases.


title:
Simulation based approach for solving Unequal Area Facility Layout
  Problems in Stochastic condition by Genetic Algorithm

abstract:
  In this study we introduce a new method to solve the Dynamics Facility Layout
Problems (DFLPs). To represent each layout, we use the slicing tree method
integrated with our proposed heuristic to obtain promising initial solutions.
Then, we consider the case of adding new departments into the current layout
with stochastic flows. We use simulation to model the complexity of stochastic
nature of the problem. To improve the quality of the initial solution a genetic
algorithm is joined with the simulation module. Finally, to demonstrate the
performance of our method, we solve several cases existing in the literature to
show the efficiency of our algorithm.


title:
Largest values of the Stern sequence, alternating binary expansions and
  continuants

abstract:
  We study the largest values of the $r$th row of Stern's diatomic array. In
particular, we prove some conjectures of Lansing. Our main tool is the
connection between the Stern sequence, alternating binary expansions and
continuants. This allows us to reduce the problem of ordering the elements of
the Stern sequence to the problem of ordering continuants. We describe an
operation that increases the value of a continuant, allowing us to reduce the
problem of largest continuants to ordering continuants of very special shape.
Finally, we order these special continuants using some identities and
inequalities involving Fibonacci numbers.


title:
Markov bases for two-way change-point models of ladder determinantal
  tables

abstract:
  To evaluate a fitting of a statistical model to given data, calculating a
conditional $p$ value by a Markov chain Monte Carlo method is one of the
effective approaches. For this purpose, a Markov basis plays an important role
because it guarantees the connectivity of the chain for unbiasedness of the
estimation, and therefore is investigated in various settings such as
incomplete tables or subtable sum constraints. In this paper, we consider the
two-way change-point model for the ladder determinantal table, which is an
extension of these two previous works. Our main result is based on the theory
of Groebner basis for the distributive lattice. We give a numerical example for
actual data.


title: Topological Drawings of Complete Bipartite Graphs

abstract:
  Topological drawings are natural representations of graphs in the plane,
where vertices are represented by points, and edges by curves connecting the
points. Topological drawings of complete graphs and of complete bipartite
graphs have been studied extensively in the context of crossing number
problems. We consider a natural class of simple topological drawings of
complete bipartite graphs, in which we require that one side of the vertex set
bipartition lies on the outer boundary of the drawing.
  We investigate the combinatorics of such drawings. For this purpose, we
define combinatorial encodings of the drawings by enumerating the distinct
drawings of subgraphs isomorphic to $K_{2,2}$ and $K_{3,2}$, and investigate
the constraints they must satisfy. We prove that a drawing of $K_{k,n}$ exists
if and only if some simple local conditions are satisfied by the encodings.
This directly yields a polynomial-time algorithm for deciding the existence of
such a drawing given the encoding. We show the encoding is equivalent to
specifying which pairs of edges cross, yielding a similar polynomial-time
algorithm for the realizability of abstract topological graphs.
  We also completely characterize and enumerate such drawings of $K_{k,n}$ in
which the order of the edges around each vertex is the same for vertices on the
same side of the bipartition. Finally, we investigate drawings of $K_{k,n}$
using straight lines and pseudolines, and consider the complexity of the
corresponding realizability problems.


title: Contact categories of disks

abstract:
  In the first part of the paper we associate a pre-additive category
$\mathcal{C}(\Sigma)$ to a closed oriented surface $\Sigma$, called the {\em
contact category} and constructed from contact structures on
$\Sigma\times[0,1]$. There are also $\mathcal{C}(\Sigma,F)$, where $\Sigma$ is
a compact oriented surface with boundary and $F\subset \partial\Sigma$ is a
finite oriented set of points which bounds a submanifold of $\partial\Sigma$,
and universal covers $\widetilde{\mathcal{C}}(\Sigma)$ and
$\widetilde{\mathcal{C}}(\Sigma,F)$ of $\mathcal{C}(\Sigma)$ and
$\mathcal{C}(\Sigma,F)$. In the second part of the paper we prove that the
universal cover of the contact category of a disk admits an embedding into its
"triangulated envelope."


title:
Optimal damping ratios of multi-axial perfectly matched layers for
  elastic-wave modeling in general anisotropic media

abstract:
  The conventional Perfectly Matched Layer (PML) is unstable for certain kinds
of anisotropic media. This instability is intrinsic and independent of PML
formulation or implementation. The Multi-axial PML (MPML) removes such
instability using a nonzero damping coefficient in the direction parallel with
the interface between a PML and the investigated domain. The damping ratio of
MPML is the ratio between the damping coefficients along the directions
parallel with and perpendicular to the interface between a PML and the
investigated domain. No quantitative approach is available for obtaining these
damping ratios for general anisotropic media. We develop a quantitative
approach to determining optimal damping ratios to not only stabilize PMLs, but
also minimize the artificial reflections from MPMLs. Numerical tests based on
finite-difference method show that our new method can effectively provide a set
of optimal MPML damping ratios for elastic-wave propagation in 2D and 3D
general anisotropic media.


title:
Multiple Magnetization Plateaus and the Magnetic Structures in $S=1/2$
  Heisenberg Model on the Checkerboard Lattice

abstract:
  We study the ground state of $S = 1/2$ Heisenberg model on the checkerboard
lattice in a magnetic field by the density matrix renormalization group (DMRG)
method with the sine-square deformation. We obtain magnetization plateaus at
$M/M_{\rm sat}=$0, 1/4, 3/8, 1/2, and 3/4 where $M_{\rm sat}$ is the saturated
magnetization. The obtained 3/4 plateau state is consistent with the exact
result, and the 1/2 plateau is found to have a four-spin resonating loop
structure similar to the six-spin loop structure of the 1/3 plateau of the
kagome lattice. Different four-spin loop structures are obtained in the 1/4 and
3/8 plateaus but no corresponding states exist in the kagome lattice. The 3/8
plateau has a unique magnetic structure of three types of four-spin local
quantum states in a $4\sqrt{2}\times2\sqrt{2}$ magnetic unit cell with a
16-fold degeneracy.


title:
All-order calculations of the spectra of superheavy elements E113 and
  E114

abstract:
  We apply a recently developed method (V. A. Dzuba, PRA 90, 012517 (2014); J.
S. M. Ginges and V. A. Dzuba, PRA 91, 042505 (2015)) to calculate energy levels
of superheavy elements Uut (Z = 113), Fl (Z = 114), and Fl+. The method
combines the linearized single-double coupledcluster technigue, the all-order
correlation potential method and configuration interaction method. Breit and
quantum electrodynamic corrections are included. The role of relativistic and
correlation effects is discussed. Similar calculations for Tl, Pb and Pb+ are
used to gauge the accuracy of the calculations.


title:
Qudit-Based Measurement-Device-Independent Quantum Key Distribution
  Using Linear Optics

abstract:
  Measurement-device-independent (MDI) method is a way to solve all detector
side-channel attacks in quantum key distribution (QKD). However, very little
work has been done on experimentally feasible qudit-based MDI-QKD scheme
although the famous (qudit-based) round-robin differential-phase-shift (RRDPS)
scheme is vulnerable to attacks on uncharacterized detectors. Here we report a
mother-of-all QKD protocol on which all provably secure qubit-based QKD schemes
known to date including the RRDPS and the so-called Chau15 schemes are based.
We also report an experimentally feasible MDI system via optical implementation
of entanglement swapping based on a recent qudit teleportation proposal by
Goyal et al. In this way, we show that all provably secure qudit-based QKD
schemes discovered to date can be made MDI.


title: Static Trace-Based Deadlock Analysis for Synchronous Mini-Go

abstract:
  We consider the problem of static deadlock detection for programs in the Go
programming language which make use of synchronous channel communications. In
our analysis, regular expressions extended with a fork operator capture the
communication behavior of a program. Starting from a simple criterion that
characterizes traces of deadlock-free programs, we develop automata-based
methods to check for deadlock-freedom. The approach is implemented and
evaluated with a series of examples.


title:
Analysis of Home Location Estimation with Iteration on Twitter Following
  Relationship

abstract:
  User's home locations are used by numerous social media applications, such as
social media analysis. However, since the user's home location is not generally
open to the public, many researchers have been attempting to develop a more
accurate home location estimation. A social network that expresses
relationships between users is used to estimate the users' home locations. The
network-based home location estimation method with iteration, which propagates
the estimated locations, is used to estimate more users' home locations. In
this study, we analyze the function of network-based home location estimation
with iteration while using the social network based on following relationships
on Twitter. The results indicate that the function that selects the most
frequent location among the friends' location has the best accuracy. Our
analysis also shows that the 88% of users, who are in the social network based
on following relationships, has at least one correct home location within
one-hop (friends and friends of friends). According to this characteristic of
the social network, we indicate that twice is sufficient for iteration.


title:
Coupling between Fano and Bragg bands in photonic band structure of
  two-dimensional metallic photonic structures

abstract:
  Frequency and transmission spectrum of two-dimensional array of metallic rods
is investigated numerically. Based on the recent analysis of the band structure
of two-dimensional photonic crystal with dielectric rods [P. Marko\v{s}, Phys.
Rev. A 92 043814 (2015)] we identify two types of bands in the frequency
spectrum: Bragg (P) bands resulting from a periodicity and Fano (F) bands which
arise from Fano resonances associated with each of the cylinders within the
periodic structure. It is shown that the existence of Fano band in a certain
frequency range is manifested by a Fano resonance in the transmittance. In
particular, we re-examine the symmetry properties of the H- polarized band
structure in the frequency range where the spectrum consists of the localized
modes associated with the single scatterer resonances and we explore process of
formation of Fano bands by identifying individual terms in the expansion of the
LCAO states. We demonstrate how the interplay between the two scattering
mechanisms affects properties of the resulting band structure when the radius
of cylinders is increased. We show that a different character of both kinds of
bands is reflected in the spatial distribution of the magnetic field which
displays patterns corresponding to the corresponding irreducible symmetry
representations.


title:
Singular-Value-Decomposition Analysis of Associative Memory in a Neural
  Network

abstract:
  We evaluate performance of associative memory in a neural network by based on
the singular value decomposition (SVD) of image data stored in the network. We
consider the situation in which the original image and its highly
coarse-grained one by SVD are stored in the network and the intermediate one is
taken as an input. We find that the performance is characterized by the
snapshot-entropy scaling inherent in the SVD: the network retrieves the
original image when the entropy of the input image is larger than the critical
value determined from the scaling. The result indicates efficiency of the SVD
as a criterion of the performance and also indicates universality of the
scaling for realistic problems beyond theoretical physics.


title: Egocentric Meets Top-view

abstract:
  Thanks to the availability and increasing popularity of Egocentric cameras
such as GoPro cameras, glasses, and etc. we have been provided with a plethora
of videos captured from the first person perspective. Surveillance cameras and
Unmanned Aerial Vehicles(also known as drones) also offer tremendous amount of
videos, mostly with top-down or oblique view-point. Egocentric vision and
top-view surveillance videos have been studied extensively in the past in the
computer vision community. However, the relationship between the two has yet to
be explored thoroughly. In this effort, we attempt to explore this relationship
by approaching two questions. First, having a set of egocentric videos and a
top-view video, can we verify if the top-view video contains all, or some of
the egocentric viewers present in the egocentric set? And second, can we
identify the egocentric viewers in the content of the top-view video? In other
words, can we find the cameramen in the surveillance videos? These problems can
become more challenging when the videos are not time-synchronous. Thus we
formalize the problem in a way which handles and also estimates the unknown
relative time-delays between the egocentric videos and the top-view video. We
formulate the problem as a spectral graph matching instance, and jointly seek
the optimal assignments and relative time-delays of the videos. As a result, we
spatiotemporally localize the egocentric observers in the top-view video. We
model each view (egocentric or top) using a graph, and compute the assignment
and time-delays in an iterative-alternative fashion.


title: Non-relativistic fermionic energy gap in the non-abelian gauge systems

abstract:
  We demonstrate that the non-relativistic fermions open the energy gap when
the SU(N) gauge bosons, mediating the interaction between fermions, acquire the
mass. Surprisingly, even though there is the SU(N) gauge symmetry, there is
always one fermionic energy gap which is not degenerate to the rest of the
$N-1$ fermions for $N \ge 3$ in the fundamental representation.


title: Low-rank Multi-view Clustering in Third-Order Tensor Space

abstract:
  The plenty information from multiple views data as well as the complementary
information among different views are usually beneficial to various tasks,
e.g., clustering, classification, de-noising. Multi-view subspace clustering is
based on the fact that the multi-view data are generated from a latent
subspace. To recover the underlying subspace structure, the success of the
sparse and/or low-rank subspace clustering has been witnessed recently. Despite
some state-of-the-art subspace clustering approaches can numerically handle
multi-view data, by simultaneously exploring all possible pairwise correlation
within views, the high order statistics is often disregarded which can only be
captured by simultaneously utilizing all views. As a consequence, the
clustering performance for multi-view data is compromised. To address this
issue, in this paper, a novel multi-view clustering method is proposed by using
\textit{t-product} in third-order tensor space. Based on the circular
convolution operation, multi-view data can be effectively represented by a
\textit{t-linear} combination with sparse and low-rank penalty using
"self-expressiveness". Our extensive experimental results on facial, object,
digits image and text data demonstrate that the proposed method outperforms the
state-of-the-art methods in terms of many criteria.


title: Data Dependent Convergence for Distributed Stochastic Optimization

abstract:
  In this dissertation we propose alternative analysis of distributed
stochastic gradient descent (SGD) algorithms that rely on spectral properties
of the data covariance. As a consequence we can relate questions pertaining to
speedups and convergence rates for distributed SGD to the data distribution
instead of the regularity properties of the objective functions. More precisely
we show that this rate depends on the spectral norm of the sample covariance
matrix. An estimate of this norm can provide practitioners with guidance
towards a potential gain in algorithm performance. For example many sparse
datasets with low spectral norm prove to be amenable to gains in distributed
settings. Towards establishing this data dependence we first study a
distributed consensus-based SGD algorithm and show that the rate of convergence
involves the spectral norm of the sample covariance matrix when the underlying
data is assumed to be independent and identically distributed (homogenous).
This dependence allows us to identify network regimes that prove to be
beneficial for datasets with low sample covariance spectral norm. Existing
consensus based analyses prove to be sub-optimal in the homogenous setting. Our
analysis method also allows us to find data-dependent convergence rates as we
limit the amount of communication. Spreading a fixed amount of data across more
nodes slows convergence; in the asymptotic regime we show that adding more
machines can help when minimizing twice-differentiable losses. Since the
mini-batch results don't follow from the consensus results we propose a
different data dependent analysis thereby providing theoretical validation for
why certain datasets are more amenable to mini-batching. We also provide
empirical evidence for results in this thesis.


title:
Doping-Induced Alterations in Electronic Structure of Copper Oxide
  Superconductors and a New Horizon for Higher Tc materials

abstract:
  By paying special attention to the fact that the doped holes induce
deformation of CuO6 octahedrons (or CuO5 pyramids) in cuprate superconductors,
we develop a non-rigid band theory treating doping-induced alterations of
energy-band structures in copper oxide superconductors. Thanks to this theory,
we obtain a complete picture of the doping-induced alteration in the electronic
structure of La2CuO4, from the spin-disordered insulating phase to the metallic
phase. We conclude that the Fermi surface structure of this cuprate in the
underdoped region consists of Fermi pockets in the antinodal region and Fermi
arcs in the nodal region, and thus that the origin of a so-called pseudogap is
closely related to the existence of Fermi pockets. Moreover, we show that the
carriers on the Fermi pockets contribute to the phonon mechanism in d-wave
superconductivity. Finally, we discuss how one will be able to find higher Tc
materials, based on the conclusions mentioned above.


title:
American Sign Language fingerspelling recognition from video: Methods
  for unrestricted recognition and signer-independence

abstract:
  In this thesis, we study the problem of recognizing video sequences of
fingerspelled letters in American Sign Language (ASL). Fingerspelling comprises
a significant but relatively understudied part of ASL, and recognizing it is
challenging for a number of reasons: It involves quick, small motions that are
often highly coarticulated; it exhibits significant variation between signers;
and there has been a dearth of continuous fingerspelling data collected. In
this work, we propose several types of recognition approaches, and explore the
signer variation problem. Our best-performing models are segmental
(semi-Markov) conditional random fields using deep neural network-based
features. In the signer-dependent setting, our recognizers achieve up to about
8% letter error rates. The signer-independent setting is much more challenging,
but with neural network adaptation we achieve up to 17% letter error rates.


title: The statistical properties of sea ice velocity fields

abstract:
  By arguing that the surface pressure field over the Arctic Ocean can be
treated as an isotropic, stationary, homogeneous, Gaussian random field,
Thorndike estimated a number of covariance functions from two years of data
(1979 and 1980). Given the active interest in changes of general circulation
quantities and indices in the polar regions during the recent few decades, the
spatial correlations in sea ice velocity fields are of particular interest. It
is thus natural to ask; "how persistent are these correlations?" To this end, a
multi-fractal stochastic treatment is developed to analyze observed Arctic sea
ice velocity fields from satellites and buoys for the period 1978 - 2015.
Having previously found that the Arctic Equivalent Ice Extent (EIE) has a white
noise structure on annual to bi-annual time scales, the connection between EIE
and ice motion is assessed. The long-term stationarity of the spatial
correlation structure of the velocity fields, and the robustness of their white
noise structure on multiple time scales is demonstrated, which (a) combine to
explain the white noise characteristics of the EIE on annual to biannual time
scales, and (b) explain why the fluctuations in the ice velocity are
proportional to fluctuations in the geostrophic winds on time scales of days to
months. Moreover, it is shown that the statistical structure of these two
quantities is commensurate from days up to years, which may be related to the
increasing prevalence of free drift in the ice pack.


title: Cooperativity and modularity in protein folding

abstract:
  A simple statistical mechanical model proposed by Wako and Sait$\hat{\rm o}$
has explained the aspects of protein folding surprisingly well. This model was
systematically applied to multiple proteins by Mu$\tilde{\rm n}$oz and Eaton
and has since been referred to as the Wako-Sait$\hat{\rm o}$-Mu$\tilde{\rm
n}$oz-Eaton (WSME) model. The success of the WSME model in explaining the
folding of many proteins has verified the hypothesis that the folding is
dominated by native interactions, which makes the energy landscape globally
biased toward native conformation. Using the WSME and other related models,
Sait$\hat{\rm o}$ emphasized the importance of the hierarchical pathway in
protein folding; folding starts with the creation of contiguous segments having
a native-like configuration and proceeds as growth and coalescence of these
segments. The $\phi$-values calculated for barnase with the WSME model
suggested that segments contributing to the folding nucleus are similar to the
structural modules defined by the pattern of native atomic contacts. The WSME
model was extended to explain folding of multi-domain proteins having a complex
topology, which opened the way to comprehensively understanding the folding
process of multi-domain proteins. The WSME model was also extended to describe
allosteric transitions, indicating that the allosteric structural movement does
not occur as a deterministic sequential change between two conformations but as
a stochastic diffusive motion over the dynamically changing energy landscape.
Statistical mechanical viewpoint on folding, as highlighted by the WSME model,
has been renovated in the context of modern methods and ideas, and will
continue to provide insights on equilibrium and dynamical features of proteins.


title:
A New Paradigm of Software Service Engineering in the Era of Big Data
  and Big Service

abstract:
  Servitization is one of the most significant trends that reshapes the
information world and society in recent years. The requirement of
collecting,storing, processing, and sharing of the Big Data has led to massive
software resources being developed and made accessible as web-based services to
facilitate such process. These services that handle the Big Data come from
various domains and heterogeneous networks, and converge into a huge
complicated service network (or ecosystem), called the Big Service.The key
issue facing the big data and big service ecosystem is how to optimally
configure and operate the related service resources to serve the specific
requirements of possible applications, i.e., how to reuse the existing service
resources effectively and efficiently to develop the new applications or
software services, to meet the massive individualized requirements of
end-users.Based on analyzing the big service ecosystem, we present in this
paper a new paradigm for software service engineering, RE2SEP
(Requirement-Engineering Two-Phase of Service Engineering Paradigm), which
includes three components: service-oriented requirement engineering,
domain-oriented service engineering, and software service development approach.
RE2SEP enables the rapid design and implementation of service solutions to
match the requirement propositions of massive individualized customers in the
Big Service ecosystem. A case study on people's mobility service in a smart
city environment is given to demonstrate the application of RE2SEP.RE2SEP can
potentially revolutionize the traditional life-cycle oriented software
engineering, leading to a new approach to software service engineering.


title: Association schemes all of whose symmetric fusion schemes are integral

abstract:
  In this paper we aim to characterize association schemes all of whose
symmetric fusion schemes have only integral eigenvalues, and classify those
obtained from a regular action of a finite group by taking its orbitals.


title: Bending-induced extension in two-dimensional crystals

abstract:
  According to the classical theory of elasticity, a plate subjected to a
bending moment always deflects with symmetric tensile and compressive strains
in its two sides, without overall deformation perpendicular to the bending
moment. Here, we find by ab initio simulations that significant overall tensile
strain can be induced by pure bending in a wide range of two-dimensional
crystals perpendicular to the bending moment, just like an accordion being bent
to open. This accordion effect is raised by asymmetric response of chemical
bonds and electron density to the bending curvature, with the tensile strain
being a power function of the curvature.


title: Material Screening with HPGe Counting Station for PandaX Experiment

abstract:
  A gamma counting station based on high-purity germanium (HPGe) detector was
set up for the material screening of the PandaX dark matter experiments in the
China Jinping Underground Laboratory. Low background gamma rate of 2.6
counts/min within the energy range of 20 to 2700 keV is achieved due to the
well-designed passive shield. The sentivities of the HPGe detetector reach
mBq/kg level for isotopes like K, U, Th, and even better for Co and Cs,
resulted from the low-background rate and the high relative detection
efficiency of 175%. The structure and performance of the counting station are
described in this article. Detailed counting results for the radioactivity in
materials used by the PandaX dark-matter experiment are presented. The
upgrading plan of the counting station is also discussed.


title: A family of fast exact pattern matching algorithms

abstract:
  A family of comparison-based exact pattern matching algorithms is described.
They utilize multi-dimensional arrays in order to process more than one
adjacent text window in each iteration of the search cycle. This approach leads
to a lower average time complexity by the cost of space. The algorithms of this
family perform well for short patterns and middle size alphabets. In such case
the shift of the window by several pattern lengths at once is quite probable,
which is the main factor of algorithm success. Our algorithms outperform the
Boyer-Moore-Horspool algorithm, either in the original version or with Sunday's
Quick search modification, in a wide area of pattern length - alphabet size
plane. In some subareas the proposed algorithms are the fastest among all known
exact pattern matching algorithms. Namely, they perform best when alphabet size
is about 30-40 and pattern length is about 4-10. Such parameters are typical
for search in natural language text databases.


title:
Bayesian Adaptive Lasso with Variational Bayes for Variable Selection in
  High-dimensional Generalized Linear Mixed Models

abstract:
  This article describes a full Bayesian treatment for simultaneous
fixed-effect selection and parameter estimation in high-dimensional generalized
linear mixed models. The approach consists of using a Bayesian adaptive Lasso
penalty for signal-level adaptive shrinkage and a fast Variational Bayes scheme
for estimating the posterior mode of the coefficients. The proposed approach
offers several advantages over the existing methods, for example, the adaptive
shrinkage parameters are automatically incorporated, no Laplace approximation
step is required to integrate out the random effects. The performance of our
approach is illustrated on several simulated and real data examples. The
algorithm is implemented in the R package glmmvb and is made available online.


title: On Concentration Properties of Partially Observed Chaotic Systems

abstract:
  This article presents results on the concentration properties of the
smoothing and filtering distributions of some partially observed chaotic
dynamical systems. We show that, rather surprisingly, for the geometric model
of the Lorenz equations, as well as some other chaotic dynamical systems, the
smoothing and filtering distributions do not concentrate around the true
position of the signal, as the number of observations tends to infinity.
Instead, under various assumptions on the observation noise, we show that the
expected value of the diameter of the support of the smoothing and filtering
distributions remains lower bounded by a constant times the standard deviation
of the noise, independently of the number of observations. Conversely, under
rather general conditions, the diameter of the support of the smoothing and
filtering distributions are upper bounded by a constant times the standard
deviation of the noise. To some extent, applications to the three dimensional
Lorenz 63' model and to the Lorenz 96' model of arbitrarily large dimension are
considered.


title: On corrected formula for graphene quantum conductivity

abstract:
  Graphene membrane irradiated by weak activating periodic electric field in
terahertz range is considered. The corrected formula for the graphene quantum
conductivity is found. The obtained formula gives complex conjugate results
when radiation polarization direction is clockwise or it is opposite clockwise.
The found formula allows us to see that the graphene membrane is an oscillating
contour. Its eigen frequency coincides with a singularity point of the
conductivity and depends on the electrons concentration. So the graphene
membrane could be used as an antenna or a transistor and its eigen frequency
could be tuned by doping in a large terahertz-infrared frequency range. The
obtained formula allows us also to calculate the graphene membrane quantum
inductivity and capacitance. The found dependence on electrons concentration is
consistent with experiments. The method of the proof is based on the study of
the time-dependent density matrix. The exact solution of the von Neumann
equation for density matrix is found for our case in linear approximation on
the external field. On this basis the induced current is studied and then the
formula for quantum conductivity as a function of external field frequency and
temperature is obtained. The method of the proof suggested in this paper could
be used to study other problems. The found formula for quantum conductivity can
be used to correct the SPPs Dispersion Relation and for the description of
radiation process. It would be useful to take the obtained results into account
when constructing devices containing graphene membrane nanoantenna. Such
project could make it possible to create wireless communications among
nanosystems. This would be promising research area of energy harvesting
applications.


title: Rotation and Mass in the Milky Way and Spiral Galaxies

abstract:
  [PASJ Review Paper]
  Rotation curves are the basic tool for deriving the distribution of mass in
spiral galaxies. In this review, we describe various methods to measure
rotation curves in the Milky Way and spiral galaxies. We then describe two
major methods to calculate the mass distribution using the rotation curve. By
the direct method, the mass is calculated from rotation velocities without
employing mass models. By the decomposition method, the rotation curve is
deconvolved into multiple mass components by model fitting assuming a black
hole, bulge, exponential disk and dark halo. The decomposition is useful for
statistical correlation analyses among the dynamical parameters of the mass
components. We also review recent observations and derived results.
  ( Full resolution copy is available at URL:
http://www.ioa.s.u-tokyo.ac.jp/~sofue/htdocs/PASJreview2016/ )


title: Entangled spins and ghost-spins

abstract:
  We study patterns of quantum entanglement in systems of spins and ghost-spins
regarding them as simple quantum mechanical toy models for theories containing
negative norm states. We define a single ghost-spin as in arXiv:1602.06505
[hep-th] as a 2-state spin variable with an indefinite inner product in the
state space. We find that whenever the spin sector is disentangled from the
ghost-spin sector (both of which could be entangled within themselves), the
reduced density matrix obtained by tracing over all the ghost-spins gives rise
to positive entanglement entropy for positive norm states, while negative norm
states have an entanglement entropy with a negative real part and a constant
imaginary part. However when the spins are entangled with the ghost-spins,
there are new entanglement patterns in general. For systems where the number of
ghost-spins is even, it is possible to find subsectors of the Hilbert space
where positive norm states always lead to positive entanglement entropy after
tracing over the ghost-spins. With an odd number of ghost-spins however, we
find that there always exist positive norm states with negative real part for
entanglement entropy after tracing over the ghost-spins.


title: Superconductivity in the ternary iridium-arsenide BaIr2As2

abstract:
  Here we report the synthesis and discovery of superconductivity in a novel
ternary iridium-arsenide compound BaIr2As2. The polycrystalline BaIr2As2 sample
was synthesized by a high temperature and high pressure method. Crystal
structural analysis indicates that BaIr2As2 crystallizes in the ThCr2Si2-type
layered tetragonal structure with space group I4/mmm (No. 139), and the lattice
parameters were refined to be a = 4.052(9) {\AA} and c = 12.787(8) {\AA}. By
the electrical resistivity and magnetic susceptibility measurements we found
type-II superconductivity in the new BaIr2As2 compound with a Tc (critical
temperature) of 2.45 K, and an upper critical field u0Hc2(0) about 0.2 T. Low
temperature specific heat measurements gave a Debye temperature about 202 K and
a distinct specific jump with delta Ce/{\gamma}Tc = 1.36, which is close to the
value of BCS weak coupling limit and confirms the bulk superconductivity in
this new BaIr2As2 compound.


title:
A short review and primer on event-related potentials in human computer
  interaction applications

abstract:
  The application of psychophysiology in human-computer interaction is a
growing field with significant potential for future smart personalised systems.
Working in this emerging field requires comprehension of an array of
physiological signals and analysis techniques.
  Event-related potentials, termed ERPs, are a stimulus- or action-locked
waveform indicating a characteristic neural response. ERPs derived from
electroencephalography have been extensively studied in basic research, and
have been applied especially in the field of brain-computer interfaces. For
ecologically-valid settings there are considerable challenges to application,
however recent work shows some promise for ERPs outside the lab. Here we
present a short review on the application of ERPs in human-computer
interaction.
  This paper aims to serve as a primer for the novice, enabling rapid
familiarisation with the latest core concepts. We put special emphasis on
everyday human-computer interface applications to distinguish from the more
common clinical or sports uses of psychophysiology.
  This paper is an extract from a comprehensive review of the entire field of
ambulatory psychophysiology, including 12 similar chapters, plus application
guidelines and systematic review. Thus any citation should be made using the
following reference:
  B. Cowley, M. Filetti, K. Lukander, J. Torniainen, A. Henelius, L. Ahonen, O.
Barral, I. Kosunen, T. Valtonen, M. Huotilainen, N. Ravaja, G. Jacucci. The
Psychophysiology Primer: a guide to methods and a broad review with a focus on
human-computer interaction. Foundations and Trends in Human-Computer
Interaction, vol. 9, no. 3-4, pp. 150--307, 2016.