title: Minimax Optimal Estimation of Convex Functions in the Supreme Norm

abstract:
  Estimation of convex functions finds broad applications in engineering and
science, while convex shape constraint gives rise to numerous challenges in
asymptotic performance analysis. This paper is devoted to minimax optimal
estimation of univariate convex functions from the H\"older class in the
framework of shape constrained nonparametric estimation. Particularly, the
paper establishes the optimal rate of convergence in two steps for the minimax
sup-norm risk of convex functions with the H\"older order between one and two.
In the first step, by applying information theoretical results on probability
measure distance, we establish the minimax lower bound under the supreme norm
by constructing a novel family of piecewise quadratic convex functions in the
H\"older class. In the second step, we develop a penalized convex spline
estimator and establish the minimax upper bound under the supreme norm. Due to
the convex shape constraint, the optimality conditions of penalized convex
splines are characterized by nonsmooth complementarity conditions. By
exploiting complementarity methods, a critical uniform Lipschitz property of
optimal spline coefficients in the infinity norm is established. This property,
along with asymptotic estimation techniques, leads to uniform bounds for bias
and stochastic errors on the entire interval of interest. This further yields
the optimal rate of convergence by choosing the suitable number of knots and
penalty value. The present paper provides the first rigorous justification of
the optimal minimax risk for convex estimation under the supreme norm.


title:
On the Geodesics in the space of K\"ahler metrics with prescribed
  singularities

abstract:
  Motivated by the results of B. Berndtsson, in this memoir we use the new
estimates developed by W. He to extend a theorem of the second author on the
existence of weak $C^{1,1}$ geodesics between two smooth non-degenerate
K\"ahler potentials to the case where the metrics on the end points may have
singularities on some analytic set and may be positive semi-definite.


title: Smoothing splines with varying smoothing parameter

abstract:
  This paper considers the development of spatially adaptive smoothing splines
for the estimation of a regression function with non-homogeneous smoothness
across the domain. Two challenging issues that arise in this context are the
evaluation of the equivalent kernel and the determination of a local penalty.
The roughness penalty is a function of the design points in order to
accommodate local behavior of the regression function. It is shown that the
spatially adaptive smoothing spline estimator is approximately a kernel
estimator. The resulting equivalent kernel is spatially dependent. The
equivalent kernels for traditional smoothing splines are a special case of this
general solution. With the aid of the Green's function for a two-point boundary
value problem, the explicit forms of the asymptotic mean and variance are
obtained for any interior point. Thus, the optimal roughness penalty function
is obtained by approximately minimizing the asymptotic integrated mean square
error. Simulation results and an application illustrate the performance of the
proposed estimator.


title:
Adaptation of frequency-domain readout for Transition Edge Sensor
  bolometers for the POLARBEAR-2 Cosmic Microwave Background experiment

abstract:
  The POLARBEAR-2 CosmicMicrowave Background (CMB) experiment aims to observe
B-mode polarization with high sensitivity to explore gravitational lensing of
CMB and inflationary gravitational waves. POLARBEAR-2 is an upgraded experiment
based on POLARBEAR-1, which had first light in January 2012. For POLARBEAR-2,
we will build a receiver that has 7,588 Transition Edge Sensor (TES) bolometers
coupled to two-band (95 and 150 GHz) polarization-sensitive antennas. For the
large array's readout, we employ digital frequency-domain multiplexing and
multiplex 32 bolometers through a single superconducting quantum interference
device (SQUID). An 8-bolometer frequency-domain multiplexing readout has been
deployed on POLARBEAR-1 experiment. Extending that architecture to 32
bolometers requires an increase in the bandwidth of the SQUID electronics to 3
MHz. To achieve this increase in bandwidth, we use Digital Active Nulling (DAN)
on the digital frequency multiplexing platform. In this paper, we present
requirements and improvements on parasitic inductance and resistance of
cryogenic wiring and capacitors used for modulating bolometers. These
components are problematic above 1 MHz. We also show that our system is able to
bias a bolometer in its superconducting transition at 3 MHz.


title: The Cyan Language

abstract:
  This is the manual of Cyan, a prototype-based object-oriented language. Cyan
supports static typing, single inheritance, mixin objects (similar to mixin
classes with mixin inheritance), generic prototypes, and Java-like interfaces.
The language has several innovations: a completely object-oriented exception
system, statically-typed closures, a kind of graphical metaobjects called
codegs, optional dynamic typing, user-defined literal objects (an innovative
way of creating objects), context objects (a generalization of closures), and
grammar methods and message sends (which makes it easy to define Domain
Specific Languages).


title:
Two dimensional numerical simulations of Supercritical Accretion Flows
  revisited

abstract:
  We study the dynamics of super-Eddington accretion flows by performing
two-dimensional radiation-hydrodynamic simulations. Compared with previous
works, in this paper we include the $T_{\theta\phi}$ component of the viscous
stress and consider various values of the viscous parameter $\alpha$. We find
that when $T_{\theta\phi}$ is included, the rotational speed of the
high-latitude flow decreases, while the density increases and decreases at the
high and low latitudes, respectively. We calculate the radial profiles of
inflow and outflow rates. We find that the inflow rate decreases inward,
following a power law form of $\dot{M}_{\rm in}\propto r^s$. The value of $s$
depends on the magnitude of $\alpha$ and is within the range of $\sim 0.4-1.0$.
Correspondingly, the radial profile of density becomes flatter compared with
the case of a constant $\dot{M}(r)$. We find that the density profile can be
described by $\rho(r)\propto r^{-p}$, and the value of $p$ is almost same for a
wide range of $\alpha$ ranging from $\alpha=0.1$ to $0.005$. The inward
decrease of inflow accretion rate is very similar to hot accretion flows, which
is attributed to the mass loss in outflows. To study the origin of outflow, we
analyze the convective stability of slim disk. We find that depending on the
value of $\alpha$, the flow is marginally stable (when $\alpha$ is small) or
unstable (when $\alpha$ is large). This is different from the case of
hydrodynamical hot accretion flow where radiation is dynamically unimportant
and the flow is always convectively unstable. We speculate that the reason for
the difference is because radiation can stabilize convection. The origin of
outflow is thus likely because of the joint function of convection and
radiation, but further investigation is required.


title:
Applications of a nonlinear evolution equation I: the parton
  distributions in the proton

abstract:
  The parton distributions in the proton are evaluated dynamically using a
nonlinear QCD evolution equation - the DGLAP equation with twist-4 (the
GLR-MQ-ZSR) corrections - starting from a low scale $\mu^2$, where the nucleon
consists of valence quarks. We find that the negative nonlinear corrections can
improve the perturbative stability of the QCD evolution equation at low $Q^2$.
Our resulting parton distributions of the proton with four free parameters are
compatible with the existing databases.
  We show that the sea quark distributions exhibit a positive and flattish
behavior at small $x$ and low $Q^2$. This approach provides a powerful tool to
connect the quark models of the hadron and various non-perturbative effects on
them at scale $\mu^2$ with the measured structure functions at high scale
$Q^2>> \mu^2$.


title: High-throughput screening of small-molecule adsorption in MOF

abstract:
  Using high-throughput screening coupled with state-of-the-art van der Waals
density functional theory, we investigate the adsorption properties of four
important molecules, H_2, CO_2, CH_4, and H_2O in MOF-74-M with M = Be, Mg, Al,
Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Zr, Nb, Ru, Rh, Pd, La, W, Os,
Ir, and Pt. We show that high-throughput techniques can aid in speeding up the
development and refinement of effective materials for hydrogen storage, carbon
capture, and gas separation. The exploration of the configurational adsorption
space allows us to extract crucial information concerning, for example, the
competition of water with CO_2 for the adsorption "pockets." We find that only
a few noble metals---Rh, Pd, Os, Ir, and Pt---favor the adsorption of CO_2 and
hence are potential candidates for effective carbon-capture materials. Our
findings further reveal significant differences in the binding characteristics
of H_2, CO_2, CH_4, and H_2O within the MOF structure, indicating that
molecular blends can be successfully separated by these nano-porous materials.


title: Applications of a nonlinear evolution equation II: the EMC effect

abstract:
  The EMC effect is studied by using the GLR-MQ-ZSR equation with minimum
number of free parameters, where the nuclear shadowing effect is a dynamical
evolution result of the equation, and nucleon swelling and Fermi motion in the
nuclear environment deform the input parton distributions. Parton distributions
of both proton and nucleus are predicted in a unified framework. We show that
the parton recombination as a higher twist correction plays an essential role
in the evolution of parton distributions either of proton or nucleus. We find
that the nuclear antishadowing contributes a part of enhancement of the ratio
of the structure functions around $x\sim 0.1$, while the other part origins
from the deformation of the nuclear valence quark distributions. We point out
that the nuclear shadowing and antishadowing effects in the gluon distribution
are not stronger than that in the quark distributions.


title: Semidefinite relaxations for semi-infinite polynomial programming

abstract:
  This paper studies how to solve semi-infinite polynomial programming (SIPP)
problems by semidefinite relaxation method. We first introduce two SDP
relaxation methods for solving polynomial optimization problems with finitely
many constraints. Then we propose an exchange algorithm with SDP relaxations to
solve SIPP problems with compact index set. At last, we extend the proposed
method to SIPP problems with noncompact index set via homogenization. Numerical
results show that the algorithm is efficient in practice.


title: On two-dimensional Dirichlet spectrum

abstract:
  We define two-dimensional Dirichlet spectrum (with respect to Euclidean norm)
as
  D_2=\lambda\in\mathbf{R} | \exists \mathbf{v}=(v_1,v_2)\in \mathbf {R}^2:
\limsup\limits_{t\rightarrow\infty} {t\cdot\psi_{v}^2(t)}=\lambda, where
\psi_{v}(t)=\min\limits_{1\leqslant q\leqslant t}\sqrt{|q v_1|^2+|q v_2|^2} is
the two-dimensional "irrationality measure function". Our main result states
the equality
  D_2=[0; 2/sqrt{3}].


title: Communication is bounded by root of rank

abstract:
  We prove that any total boolean function of rank $r$ can be computed by a
deterministic communication protocol of complexity $O(\sqrt{r} \cdot \log(r))$.
Equivalently, any graph whose adjacency matrix has rank $r$ has chromatic
number at most $2^{O(\sqrt{r} \cdot \log(r))}$. This gives a nearly quadratic
improvement in the dependence on the rank over previous results.


title: Ideals of the core of C*-algebras associated with self-similar maps

abstract:
  We give a complete classification of the ideals of the core of the
C*-algebras associated with self-similar maps under a certain condition. Any
ideal is completely determined by the intersection with the coefficient algebra
C(K) of the self-similar set K. The corresponding closed subset of K is
described by the singularity structure of the self-similar map. In particular
the core is simple if and only if the self-similar map has no branch point. A
matrix representation of the core is essentially used to prove the
classification.


title:
Temperature Modulation of the Transmission Barrier in Quantum Point
  Contacts

abstract:
  We investigate near-equilibrium ballistic transport through a quantum point
contact (QPC) along a GaAs/AlGaAs heterojunction with a transfer matrix
technique, as a function of temperature and the shape of the potential barrier
in the QPC. Our analysis is based on a three-dimensional (3D)
quantum-mechanical variational model within the Hartree-Fock approximation that
takes into account the vertical depletion potential from ionized acceptors in
GaAs and the gate-induced transverse confinement potential that reduce to an
effective slowly-varying one-dimensional (1D) potential along the narrow
constriction. The calculated zero-temperature transmission exhibits a shoulder
ranging from 0.3 to 0.6 depending on the length of the QPC and the profile of
the barrier potential. The effect is a consequence of the compressibility peak
in the 1D electron gas and is enhanced for anti-ferromagnetic interaction among
electrons in the QPC, but is smeared out once temperature is increased by a few
tenths of a kelvin.


title:
Effect of Spin-Orbit Interaction on (4d)^3- and (5d)^3 -Based
  Transition-Metal Oxides

abstract:
  The effects of a spin-orbit interaction on transition-metal ions of (4d)^3-
and (5d)^3 -based oxides in which three electrons occupy t_{2g} orbitals are
studied. The amplitude of the magnetic moment of d electrons on the 5d and 4d
orbitals is estimated by numerical diagonalization. It is found that the
magnetic moment is reduced by the spin-orbit interaction. It is suggested that
(4d)^3- and (5d)^3 -based oxides are located in the middle of the L-S and J-J
coupling schemes.


title: Artificial Ant Species on Solving Optimization Problems

abstract:
  During the last years several ant-based techniques were involved to solve
hard and complex optimization problems. The current paper is a short study
about the influence of artificial ant species in solving optimization problems.
There are studied the artificial Pharaoh Ants, Lasius Niger and also artificial
ants with no special specificity used commonly in Ant Colony Optimization.


title:
Loss Distribution Approach for Operational Risk Capital Modelling under
  Basel II: Combining Different Data Sources for Risk Estimation

abstract:
  The management of operational risk in the banking industry has undergone
significant changes over the last decade due to substantial changes in
operational risk environment. Globalization, deregulation, the use of complex
financial products and changes in information technology have resulted in
exposure to new risks very different from market and credit risks. In response,
Basel Committee for banking Supervision has developed a regulatory framework,
referred to as Basel II, that introduced operational risk category and
corresponding capital requirements. Over the past five years, major banks in
most parts of the world have received accreditation under the Basel II Advanced
Measurement Approach (AMA) by adopting the loss distribution approach (LDA)
despite there being a number of unresolved methodological challenges in its
implementation. Different approaches and methods are still under hot debate. In
this paper, we review methods proposed in the literature for combining
different data sources (internal data, external data and scenario analysis)
which is one of the regulatory requirement for AMA.


title:
Gaussian Curvature and Global effects : gravitational Aharonov-Bohm
  effect revisited

abstract:
  Using the Gauss-Bonnet formula, integral of the Gaussian curvature over a
2-surface enclosed by a curve in the asymptotically flat region of a static
spacetime was found to be a measure of a gravitational analogue of
Aharonov-Bohm effect by Ford and Vilenkin in the linearized regime. Employing
the 1+3 formulation of spacetime decomposition we study the same effect in the
context of full Einstein field equations for stationary spacetimes. Applying
our approach to static tube-like and cylindrical distributions of dust not only
we recover their result but also obtain an extra term which is interpreted to
be representing the classical version of the Colella-Overhauser-Werner effect
(the COW experiment).


title:
1D+4D-VAR data assimilation of lightning with WRFDA system using
  nonlinear observation operators

abstract:
  This paper addresses the impact of assimilating data from the Earth Networks
Total Lightning Network (ENTLN) during two cases of severe weather. Data from
the ENTLN serve as a substitute for those from the upcoming launch of the GOES
Lightning Mapper (GLM). We use the Weather Research and Forecast (WRF) model
and variational data assimilation techniques at 9 km spatial resolution. The
main goal is to examine the potential impact of lightning observations from the
future GLM.
  Previous efforts to assimilate lightning observations mainly utilized nudging
approaches. We develop three more sophisticated approaches, 3D-VAR WRFDA and
1D+nD-VAR (n=3,4) WRFDA schemes that currently are being considered for
operational implementation by the National Centers for Environmental Prediction
(NCEP) and the Naval Research Laboratory (NRL). This research uses Convective
Available Potential Energy (CAPE) as a proxy between lightning data and model
variables.
  To test the performance of the aforementioned schemes, we assess the quality
of resulting analysis and forecasts of precipitation compared to those from a
control experiment and verify them against NCEP stage IV precipitation. Results
demonstrate that assimilating lightning observations improves precipitation
statistics during the assimilation window and for 3-7 h thereafter. The
1D+4D-VAR approach performs best, significantly improving precipitation root
mean square errors by 25% and 27.5% compared to the control during the
assimilation window on the two cases. This finding confirms that the
variational nD-VAR (n=3,4) assimilation of lightning observations improves the
accuracy of moisture analyses and forecasts. Finally, we briefly discuss
limitations inherent in the current lightning assimilation schemes, their
implications, and possible ways to improve them.


title:
A Note on the Multivariate CLT and Convergence of Levy Processes at Long
  and Short Times

abstract:
  We show that a necessary and sufficient condition for the sum of iid random
vectors to converge (under appropriate shifting and scaling) to a multivariate
Gaussian distribution is that the truncated second moment matrix is slowly
varying at infinity. This is more natural than the standard conditions, and
allows for the possibility that the limiting Gaussian distribution is
degenerate (so long as it is not concentrated at a point). We also give
necessary and sufficient conditions for a d-dimensional Levy process to
converge (under appropriate shifting and scaling) to a multivariate Gaussian
distribution as time approaches zero or infinity.


title:
Convergence and Optimality of Adaptive Methods for Poisson's Equation in
  the FEEC Framework

abstract:
  Finite Element Exterior Calculus (FEEC) was developed by Arnold, Falk,
Winther and others over the last decade to exploit the observation that mixed
variational problems can be posed on a Hilbert complex, and Galerkin-type mixed
methods can then be obtained by solving finite-dimensional subcomplex problems.
Chen, Holst, and Xu (Math. Comp. 78 (2009) 35-53) established convergence and
optimality of an adaptive mixed finite element method using Raviart-Thomas or
Brezzi-Douglas-Marini elements for Poisson's equation on contractible domains
in two dimensions, which can be viewed as a boundary problem on the de Rham
complex. Recently Demlow and Hirani (Found. Math. Comput. 14 (2014) 1337-1371)
developed fundamental tools for a posteriori analysis on the de Rham complex.
In this paper, we use tools in FEEC to construct convergence and complexity
results on domains with general topology and spatial dimension. In particular,
we construct a reliable and efficient error estimator and a sharper
quasi-orthogonality result using a novel technique. Without marking for data
oscillation, our adaptive method is a contraction with respect to a total error
incorporating the error estimator and data oscillation.


title:
High-Contrast Near-Infrared Imaging Polarimetry of the Protoplanetary
  Disk around RY Tau

abstract:
  We present near-infrared coronagraphic imaging polarimetry of RY Tau. The
scattered light in the circumstellar environment was imaged at H-band at a high
resolution (~0".05) for the first time, using Subaru-HiCIAO. The observed
polarized intensity (PI) distribution shows a butterfly-like distribution of
bright emission with an angular scale similar to the disk observed at
millimeter wavelengths. This distribution is offset toward the blueshifted jet,
indicating the presence of a geometrically thick disk or a remnant envelope,
and therefore the earliest stage of the Class II evolutionary phase. We perform
comparisons between the observed PI distribution and disk models with: (1) full
radiative transfer code, using the spectral energy distribution (SED) to
constrain the disk parameters; and (2) monochromatic simulations of scattered
light which explore a wide range of parameters space to constrain the disk and
dust parameters. We show that these models cannot consistently explain the
observed PI distribution, SED, and the viewing angle inferred by millimeter
interferometry. We suggest that the scattered light in the near-infrared is
associated with an optically thin and geometrically thick layer above the disk
surface, with the surface responsible for the infrared SED. Half of the
scattered light and thermal radiation in this layer illuminates the disk
surface, and this process may significantly affect the thermal structure of the
disk.


title: A Framework for Software-as-a-Service Selection and Provisioning

abstract:
  As cloud computing is increasingly transforming the information technology
landscape, organizations and businesses are exhibiting strong interest in
Software-as-a-Service (SaaS) offerings that can help them increase business
agility and reduce their operational costs. They increasingly demand services
that can meet their functional and non-functional requirements. Given the
plethora and the variety of SaaS offerings, we propose, in this paper, a
framework for SaaS provisioning, which relies on brokered Service Level
agreements (SLAs), between service consumers and SaaS providers. The Cloud
Service Broker (CSB) helps service consumers find the right SaaS providers that
can fulfil their functional and non-functional requirements. The proposed
selection algorithm ranks potential SaaS providers by matching their offerings
against the requirements of the service consumer using an aggregate utility
function. Furthermore, the CSB is in charge of conducting SLA negotiation with
selected SaaS providers, on behalf of service consumers, and performing SLA
compliance monitoring.


title: An Improved Structure Of Reversible Adder And Subtractor

abstract:
  In today's world everyday a new technology which is faster, smaller and more
complex than its predecessor is being developed. The increased number of
transistors packed onto a chip of a conventional system results in increased
power consumption that is why Reversible logic has drawn attention of
Researchers due to its less heat dissipating characteristics. Reversible logic
can be imposed over applications such as quantum computing, optical computing,
quantum dot cellular automata, low power VLSI circuits, DNA computing. This
paper presents the reversible combinational circuit of adder, subtractor and
parity preserving subtractor. The suggested circuit in this paper are designed
using Feynman, Double Feynman and MUX gates which are better than the existing
one in literature in terms of Quantum cost, Garbage output and Total logical
calculations.


title: Horizontal symmetries of leptons with a massless neutrino

abstract:
  Residual symmetry $G_\nu$ of neutrino mass matrix with a massless neutrino
and embedding of $G_\nu$ and the residual symmetry $G_l$ of the charged lepton
mass matrix into finite discrete groups $G$ is discussed. Massless neutrino
results if $G_\nu$ and hence $G$ are subgroups of $U(3)$ rather than of
$SU(3)$. Structure of the resulting leptonic mixing matrix $U_{PMNS}$ is
discussed in three specific examples based on groups (a) $\Sigma(3N^3)$, (b)
$\Sigma(2N^2)$ and (c) $S_4(2) \equiv A_4\rtimes Z_4$. $\Sigma(3N^3)$ groups
are able to reproduce either the second or the third column of $U_{PMNS}$
correctly. $\Sigma(2N^2)$ groups lead to prediction $\theta_{13}=0$,
$\theta_{23}=\frac{\pi}{4}$ for the reactor and atmospheric mixing angles
respectively if neutrino mass hierarchy is inverted. Solar angle remains
undetermined in this case. This also gets determined when $G=S_4(2)$ which can
give bi-maximal mixing for inverted hierarchy. Examples (b) and (c) provide a
good zeroth order approximation to realistic leptonic mixing with a massless
neutrino. We also present an example of the specific model based on $S_4(2)$
symmetry in which a massless neutrino and viable leptonic mixing angles are
obtained.


title:
An Analysis of Momentum Fractions of Quarks and Gluons in a model of
  Proton

abstract:
  Momentum sum rule can be used as an inequality to estimate the lower and
upper bounds of the momentum fractions of quarks and gluons in a model of
proton valid in a limited \textit{x} range. We compute such bounds in a
self-similarity based model of proton structure function valid in the range $
6.2\times 10^{-7} \leq x \leq 10^{-2} $. The results conform to the asymptotic
QCD expectations.


title: Symmetry breaking gives rise to energy spectra of three states of matter

abstract:
  A fundamental task of statistical physics is to start with a microscopic
Hamiltonian, predict the system's statistical properties and compare them with
observable data. A notable current fundamental challenge is to tell whether and
how an interacting Hamiltonian predicts different energy spectra, including
solid, liquid and gas phases. Here, we propose a new idea that enables a
unified description of all three states of matter. We introduce a generic form
of an interacting phonon Hamiltonian with ground state configurations
minimising the potential. Symmetry breaking, from the group of rotations in
reciprocal space to its subgroup, leads to emergence of energy gaps of shear
excitations as a consequence of the Goldstone theorem, and readily results in
the emergence of energy spectra of solid, liquid and gas phases.


title: Observation of a Berry phase anti-damping spin-orbit torque

abstract:
  Recent observations of current-induced magnetization switching at
ferromagnet/normal-conductor interfaces have important consequences for future
magnetic memory technology. In one interpretation, the switching originates
from carriers with spin-dependent scattering giving rise to a relativistic
anti-damping spin-orbit torque (SOT) in structures with broken space-inversion
symmetry. The alternative interpretation combines the relativistic spin Hall
effect (SHE), making the normal-conductor an injector of a spin-current, with
the non-relativistic spin-transfer torque (STT) in the ferromagnet. Remarkably,
the SHE in these experiments originates from the Berry phase effect in the band
structure of a clean crystal and the anti-damping STT is also based on a
disorder-independent transfer of spin from carriers to magnetization. Here we
report the observation of an anti-damping SOT stemming from an analogous Berry
phase effect to the SHE. The SOT alone can therefore induce magnetization
dynamics based on a scattering-independent principle. The ferromagnetic
semiconductor (Ga,Mn)As we use has a broken space-inversion symmetry in the
crystal. This allows us to consider a bare ferromagnetic element which
eliminates by design any SHE related contribution to the spin torque. We
provide an intuitive picture of the Berry phase origin of the anti-damping SOT
and a microscopic modeling of measured data.


title: Speckle Reduction with Adaptive Stack Filters

abstract:
  Stack filters are a special case of non-linear filters. They have a good
performance for filtering images with different types of noise while preserving
edges and details. A stack filter decomposes an input image into stacks of
binary images according to a set of thresholds. Each binary image is then
filtered by a Boolean function, which characterizes the filter. Adaptive stack
filters can be computed by training using a prototype (ideal) image and its
corrupted version, leading to optimized filters with respect to a loss
function. In this work we propose the use of training with selected samples for
the estimation of the optimal Boolean function. We study the performance of
adaptive stack filters when they are applied to speckled imagery, in particular
to Synthetic Aperture Radar (SAR) images. This is done by evaluating the
quality of the filtered images through the use of suitable image quality
indexes and by measuring the classification accuracy of the resulting images.
We used SAR images as input, since they are affected by speckle noise that
makes classification a difficult task.


title:
The categories $L$\textbf{-Top_0} and $L$\textbf{Sob} as epireflective
  hulls

abstract:
  We show that the category $L\textbf{-Top}_{0}$ of $T_{0}$-$L$-topological
spaces is the epireflective hull of Sierpinski $L$-topological space in the
category $L\textbf{-Top}$ of $L$-topological spaces and the category
$L\textbf{-Sob}$ of sober $L$-topological spaces is the epireflective hull of
Sierpinski $L$-topological space in the category $L\textbf{-Top}_{0}$.


title:
Flavor Dependence of Meson Melting Temperature in Relativistic Potential
  Model

abstract:
  We study the melting temperature of heavy mesons in the hot medium of light
quarks. By solving the covariant Schr\"odinger equations at finite temperature
for mesons $D$, $\phi$ and $J/\psi$, we obtained the temperature dependence of
their masses, binding energies and averaged sizes and found the flavor
dependence of the melting temperature: $T_D \simeq T_\phi < T_{J/\psi}$. The
sequential melting temperature can explain the difference in meson elliptic
flow observed in heavy ion collisions.


title: Decoherence, Entanglement and Cosmic Evolution

abstract:
  The possible imprint of quantum decoherence, in the framework of cosmology,
is here investigated. Particular attention is paid to the observational fact
that entanglement could lead to the interaction of different eras of cosmic
evolution. The role played by decoherence provides the existence of "quantum
entanglement" between cosmological eras giving, as observational results,
dynamical constraints on the corresponding cosmological models.


title:
Activity and Steady-State Kinetics of One-Dimensional Kinetic Ising
  Model

abstract:
  In this work we focused on the kinetics of a one-dimensional Ising system
(1DIS) with constant nearest-neighbor interaction (NNI). The exact solution of
both thermodynamics and kinetics of this system under quasi-chemical
approximation (QCA) had been shown in the literature, and the equilibrium
solution was exact. In this work, it was discussed why QCA applied the best in
the case of 1DIS with constant NNI. Furthermore, extension had been made to
discuss that due to this special reason, perhaps the kinetics of the system
under QCA is the correct steady-state kinetics. Inspired by this observation,
the activity and activity coefficients of the system was studied closely to
re-examine the form of the equation of motion under QCA. A novel concept---the
instantaneous activities and the corresponding instantaneous activity
coefficients---was introduced, and in terms of these quantities the kinetics
seemed to be much simpler and physically more meaningful. The chevron plot of
this system was also discussed and new way of looking at the \emph{rollover} of
chevron plots was presented.


title: Visibility graph analysis of solar wind velocity

abstract:
  We analyze in situ measurements of solar wind velocity obtained by Advanced
Composition Explorer (ACE) spacecraft and Helios spacecraft during the years
1998-2012 and 1975-1983 respectively. The data belong to mainly solar cycle 23
(1996-2008) and solar cycle 21 (1976-1986) respectively. We use Directed
Horizontal Visibility graph (DHVg) algorithm and estimate a graph functional,
namely, the degree distance (D) as the Kullback-Leibler divergence (KLD)
argument to understand time irreversibility of solar wind time series. We
estimate this degree distance irreversibility parameter for these time series
at different phases of solar activity cycle. Irreversibility parameter is first
established for known dynamical data and then applied for solar wind velocity
time series. It is observed that irreversibility in solar wind velocity
fluctuations show similar behaviour at 0.3 AU (Helios data) and 1 AU (ACE
data). Moreover it changes over the different phases of solar activity cycle.


title:
A dynamic symbolic geometry environment based on the Gr\"obnerCover
  algorithm for the computation of geometric loci and envelopes

abstract:
  An enhancement of the dynamic geometry system GeoGebra for the automatic
symbolic computation of algebraic loci and envelopes is presented. Given a
GeoGebra construction, the prototype, after rewriting the construction as a
polynomial system in terms of variables and parameters, uses an implementation
of the recent Gr\"obnerCover algorithm to obtain the algebraic description of
the sought locus/envelope as a locally closed set. The prototype shows the
applicability of these techniques in general purpose dynamic geometry systems.


title: Eventual Linear Ranking Functions

abstract:
  Program termination is a hot research topic in program analysis. The last few
years have witnessed the development of termination analyzers for programming
languages such as C and Java with remarkable precision and performance. These
systems are largely based on techniques and tools coming from the field of
declarative constraint programming. In this paper, we first recall an algorithm
based on Farkas' Lemma for discovering linear ranking functions proving
termination of a certain class of loops. Then we propose an extension of this
method for showing the existence of eventual linear ranking functions, i.e.,
linear functions that become ranking functions after a finite unrolling of the
loop. We show correctness and completeness of this algorithm.


title:
Wide range equation of state for fluid hydrogen within density
  functional theory

abstract:
  Wide range equation of state (EOS) for liquid hydrogen is ultimately built by
combining two kinds of density functional theory (DFT) molecular dynamics
simulations, namely, first-principles molecular dynamics simulations and
orbital-free molecular dynamics simulations. Specially, the present
introduction of short cutoff radius pseudopotentials enables the hydrogen EOS
to be available in the range $9.82\times10^{-4}$ to $1.347\times10^{3}$
g/cm$^{3}$ and up to $5\times10^{7}$ K. By comprehensively comparing with
various attainable experimental and theoretical data, we derive the conclusion
that our DFT-EOS can be readily and reliably conducted to hydrodynamic
simulations of the inertial confinement fusion.


title:
First-principles study of temperature-dependent diffusion coefficients
  for helium in $\alpha$-Ti

abstract:
  The temperature-dependent diffusion coefficients of interstitial helium atom
in $\alpha$-Ti are predicted using the transition state theory. The microscopic
parameters in the pre-factor and activation energy of the impurity diffusion
coefficients are obtained from first-principles total energy and phonon
calculations including the full coupling between the vibrational modes of the
diffusing atom and the host lattice. The climbing image nudged elastic band
(CINEB) method is used to search for the minimum energy pathways and associated
saddle point structures. It is demonstrated that the diffusion coefficients
within the \emph{xy} plane ($D_{xy}$) is always higher than that along the
\emph{z} axis ($D_{z}$), showing remarkable anisotropy. Also, it is found that
the formation of helium dimer centered at the octahedral site reduces the total
energy and confines the diffusion of helium atoms.


title:
Network Inference Using Steady State Data and Goldbeter-Koshland
  Kinetics

abstract:
  Network inference approaches are widely used to shed light on regulatory
interplay between molecular players such as genes and proteins. Biochemical
processes underlying networks of interest (e.g. gene regulatory or protein
signalling networks) are generally nonlinear. In many settings, knowledge is
available concerning relevant chemical kinetics. However, existing network
inference methods for continuous, steady-state data are typically rooted in
statistical formulations, which do not exploit chemical kinetics to guide
inference. Herein, we present an approach to network inference for steady-state
data that is rooted in non-linear descriptions of biochemical mechanism. We use
equilibrium analysis of chemical kinetics to obtain functional forms that are
in turn used to infer networks using steady-state data. The approach we propose
is directly applicable to conventional steady-state gene expression or
proteomic data and does not require knowledge of either network topology or any
kinetic parameters. We illustrate the approach in the context of protein
phosphorylation networks, using data simulated from a recent mechanistic model
and proteomic data from cancer cell lines. In the former, the true network is
known and used for assessment, whereas in the latter, results are compared
against known biochemistry. We find that the proposed methodology is more
effective at estimating network topology than methods based on linear models.


title:
Diffuse planar phase boundaries in a two-phase fluid with one
  incompressible phase

abstract:
  This note studies a family of Navier-Stokes-Allen-Cahn systems parameterized
by temperature. Derived from an internal energy that corresponds to one
incompressible and one compressible phase, this family is considered as a
simple model for water. Decreasing temperature across a critical value, a
transition takes places from a situation without towards one with planar
diffuse phase boundaries.


title: Qualified Trust, not Surveillance, is the Basis of a Stable Society

abstract:
  Peaceful citizens and hard-working taxpayers are under government
surveillance. Confidential communication of journalists is intercepted.
Civilians are killed by drones, without a chance to prove their innocence. How
could it come that far? And what are the alternatives?


title:
Analytical Coexistence Benchmark for Assessing the Utmost Interference
  Tolerated by IEEE 802.20

abstract:
  Whether it is crosstalk, harmonics, or in-band operation of wireless
technologies, interference between a reference system and a host of offenders
is virtually unavoidable. In past contributions, a benchmark has been
established and considered for coexistence analysis with a number of
technologies including FWA, UMTS, and WiMAX. However, the previously presented
model does not take into account the mobility factor of the reference node in
addition to a number of interdependent requirements regarding the link
direction, channel state, data rate and system factors; hence limiting its
applicability for the MBWA (IEEE 802.20) standard. Thus, over diverse modes, in
this correspondence we analytically derived the greatest aggregate interference
level tolerated for high-fidelity transmission tailored specifically for the
MBWA standard. Our results, in the form of benchmark indicators, should be of
particular interest to peers analyzing and researching RF coexistence scenarios
with this new protocol.


title: Plasmonic dark field microscopy with a polymer substrate

abstract:
  In this letter, a plasmonic dark field microscopy taking advantages of the
polymer loaded surface plasmon polariton waveguide (PLSPPW) is experimentally
demonstrated. The dye molecules (Rhodamine 6G, Rh6G) are doped in the PLSPPW to
launch the plasmonic waves or guided waves. Due to the localized property of
these waves, the near-field optical energy on the surface of PLSPPW can be
scattered into the far-field only in the presence of the objects. The
scattering signals then form the dark-field image of the objects. The proposed
technique just utilizes a chip-scale integrated plasmonic multilayered
structure which is highly compatible with the conventional optical microscopy.
The polymer film involved in the PLSPPW also brings about the merits of small
roughness, good stability and bio-compatibility


title: Temperature-dependent pressure-induced softening in Zn(CN)$_{2}$

abstract:
  We investigate the temperature dependence of the pressure-induced softening
in the negative thermal expansion material Zn(CN)$_2$ using neutron powder
diffraction and molecular dynamics simulations. Both the simulation and
experiment show that the pressure-induced softening only occurs above a minimum
temperature and also weakens at high temperatures.


title: Dark radiation from a unified dark fluid model

abstract:
  We present a unified dark fluid model to describe the possible evolutionary
behavior of $\Delta N_\mathrm{eff}$ in dark radiation. This model can be viewed
as an interacting model for the dark sectors, in which dark matter interacts
with dark radiation. We show that the evolution of $\Delta N_\mathrm{eff}$ can
be nicely explained without some drawbacks, such as the blowup of $\Delta
N_\mathrm{eff}$ and the non-vanishing interaction at the late time.


title: Searching for New Physics with bbar -> sbar Bs -> V_1 V_2 Penguin Decays

abstract:
  We present the most general (six-helicity) angular analysis of Bs -> V_1 (->
P_1P'_1) V_2 (-> P_2P'_2) (V_i is a vector meson, and P_i, P'_i are
pseudoscalars). We focus on final states accessible to both Bs and Bsbar --
these are mainly bbar -> sbar penguin decays. We also derive the most general
decay amplitude, and discuss the differences between it and that used by LHCb
in its analysis of Bs -> phi phi. In the standard model, all CP violation is
predicted to be small, so that the simple measurement of a sizeable
CP-violating observable indicates the presence of new physics. A full fit to
the data is not necessary. By determining which of the CP-violating observables
are nonzero, one can learn about the structure of the underlying NP. Finally,
we apply the angular analysis to Bs -> K^{*0} Kbar^{*0}, and show that there
are numerous CP-violating observables that remain in the untagged data sample.


title: Spectral perturbation theory and the two weights problem

abstract:
  The famous two weights problem consists in characterising all possible pairs
of weights such that the Hardy projection is bounded between the corresponding
weighted $L^2$ spaces. Koosis' theorem of 1980 gives a way to construct a
certain class of pairs of weights. We show that Koosis' theorem is closely
related to (in fact, is a direct consequence of) a spectral perturbation model
suggested by de Branges in 1962. Further, we show that de Branges' model
provides an operator-valued version of Koosis' theorem.


title: Emotional Expression Classification using Time-Series Kernels

abstract:
  Estimation of facial expressions, as spatio-temporal processes, can take
advantage of kernel methods if one considers facial landmark positions and
their motion in 3D space. We applied support vector classification with kernels
derived from dynamic time-warping similarity measures. We achieved over 99%
accuracy - measured by area under ROC curve - using only the 'motion pattern'
of the PCA compressed representation of the marker point vector, the so-called
shape parameters. Beyond the classification of full motion patterns, several
expressions were recognized with over 90% accuracy in as few as 5-6 frames from
their onset, about 200 milliseconds.


title: Propagation dynamics on the Fermi-Pasta-Ulam lattices

abstract:
  The spatiotemporal propagation of a momentum excitation on the finite
Fermi-Pasta-Ulam lattices is investigated. The competition between the solitary
wave and phonons gives rise to interesting propagation behaviors. For a
moderate nonlinearity, the initially excited pulse may propagate coherently
along the lattice for a long time in a solitary wave manner accompanied by
phonon tails. The lifetime of the long-transient propagation state exhibits a
sensitivity to the nonlinear parameter. The solitary wave decays exponentially
during the final loss of stability, and the decay rate varying with the
nonlinear parameter exhibits two different scaling laws. This decay is found to
be related to the largest Lyapunov exponent of the corresponding Hamiltonian
system, which manifests a transition from weak to strong chaos. The
mean-free-path of the solitary waves is estimated in the strong chaos regime,
which may be helpful to understand the origin of anomalous conductivity in the
Fermi-Pasta-Ulam lattice.


title: Perturbations of intermediate C*-subalgebras for simple C*-algebras

abstract:
  We study uniform perturbations of intermediate C*-subalgebras of inclusions
of simple C*-algebras. If a unital simple C*-algebra has a simple C*-subalgebra
of finite index, then sufficiently close simple intermediate C*-subalgebras are
unitarily equivalent. These C*-subalgebras need not to be nuclear. The unitary
can be chosen in the relative commutant algebra. An imediate corollary is the
following: If the relative commutant is trivial, then the set of intermediate
C*-subagebras is a finite set.


title:
Performance Evaluation of Low Power MIPS Crypto Processor based on
  Cryptography Algorithms

abstract:
  This paper presents the design and implementation of low power 32-bit
encrypted and decrypted MIPS processor for Data Encryption Standard (DES),
Triple DES, Advanced Encryption Standard (AES) based on MIPS pipeline
architecture. The organization of pipeline stages has been done in such a way
that pipeline can be clocked at high frequency. Encryption and Decryption
blocks of three standard cryptography algorithms on MIPS processor and
dependency among themselves are explained in detail with the help of a block
diagram. Clock gating technique is used to reduce the power consumption in MIPS
crypto processor. This approach results in processor that meets power
consumption and performance specification for security applications. Proposed
Implementation approach concludes higher system performance while reducing
operating power consumption. Testing results shows that the MIPS crypto
processor operates successfully at a working frequency of 218MHz and a
bandwidth of 664Mbits/s.


title: Translational and great Darboux cyclides

abstract:
  A surface that is the pointwise sum of circles with non-parallel planes in
Euclidean space contains no more than two circles through each point. A surface
that is smooth and the pointwise product of circles in the unit-quaternions
contains either two, four or five circles through each point. A surface in a
unit-sphere that contains two great circles through a general point must be
smooth and contains either four, six or infinitely many circles through each
point. These are some corollaries from our classification of translational and
great Darboux cyclides. We use the combinatorics associated to the set of low
degree curves on such surfaces modulo numerical equivalence.


title:
Loss of stability of a solitary wave through exciting a cnoidal wave on
  a Fermi-Pasta-Ulam ring

abstract:
  The spatiotemporal propagation behavior of a solitary wave is investigated on
a Fermi-Pasta-Ulam ring. We observe the emergence of a cnoidal wave excited by
the solitary wave. The cnoidal wave may coexist with the solitary wave for a
long time associated with the periodic exchange of energy between these two
nonlinear waves. The module of the cnoidal wave, which is considered as an
indicator of the nonlinearity, is found to oscillate with the same period of
the energy exchange. After the stage of coexistence, the interaction between
these two nonlinear waves leads to the destruction of the cnoidal wave by the
radiation of phonons. Finally, the interaction of the solitary wave with
phonons leads to the loss of stability of the solitary wave.


title: Practical Inlining of Functions with Free Variables

abstract:
  A long-standing practical challenge in the optimization of higher-order
languages is inlining functions with free variables. Inlining code statically
at a function call site is safe if the compiler can guarantee that the free
variables have the same bindings at the inlining point as they do at the point
where the function is bound as a closure (code and free variables). There have
been many attempts to create a heuristic to check this correctness condition,
from Shivers' kCFA-based reflow analysis to Might's Delta-CFA and anodization,
but all of those have performance unsuitable for practical compiler
implementations. In practice, modern language implementations rely on a series
of tricks to capture some common cases (e.g., closures whose free variables are
only top-level identifiers such as +) and rely on hand-inlining by the
programmer for anything more complicated.
  This work provides the first practical, general approach for inlining
functions with free variables. We also provide a proof of correctness, an
evaluation of both the execution time and performance impact of this
optimization, and some tips and tricks for implementing an efficient and
precise control-flow analysis.


title:
Properties of Galactic Dark Matter: Constraints from Astronomical
  Observations

abstract:
  The distributions of normal matter and of dark matter in the Galaxy are
coupled to each other as they both move in the common gravitational potential.
In order to fully exploit this interplay and to derive the various properties
of dark matter relevant to their direct and indirect detection, we have
comprehensively reviewed the astronomical observations of the spatial and
velocity distributions of the components of normal matter. We then postulate
that the phase-space distribution of dark matter follows a lowered-isothermal
form and self-consistently solve Poisson's equation to construct several models
for the spatial and velocity distributions of dark matter. In this paper, we
compute the total gravitational potential of the normal and dark matter
components and investigate their consistency with current observations of the
rotation curve of the Galaxy and of the spatial and velocity distributions of
blue horizontal-branch and blue straggler stars. Even with this demand of
consistency, a large number of models with a range of parameters characterizing
the dark matter distribution remain. We find the best choice of parameters,
within the range of allowed values, for the surface density of the disk 55
M$_\odot$ pc$^{-2}$, are the following: the dark matter density at the Galactic
center $\rho_{DM,c}\approx 100-250$ GeV cm$^{-3}$, the local dark matter
density $\rho_{DM}(R_0) \approx 0.56-0.72$ GeV cm$^{-3}$, and the
root-mean-speed of dark matter particles $< v_{DM}^{2}(R_0)>
^{1/2}\approx490-550$ km s$^{-1}$. We also discuss possible astronomical
observations that may further limit the range of the allowed models.


title:
Magnetic susceptibility and Landau diamagnetism of a quantum collisional
  Plasmas with arbitrary degree of degeneration of electronic gas

abstract:
  The kinetic description of magnetic susceptibility and Landau diamagnetism of
quantum collisional plasmas with any degeration of electronic gas is given. The
correct expression of electric conductivity of quantum collisional plasmas with
any degeration of electronic gas (see A. V. Latyshev and A. A. Yushkanov,
Transverse electrical conductivity of a quantum collisional plasma in the
Mermin approach. - Theor. and Math. Phys., V. 175(1):559-569 (2013)) is used.


title: Collaborative 20 Questions for Target Localization

abstract:
  We consider the problem of 20 questions with noise for multiple players under
the minimum entropy criterion in the setting of stochastic search, with
application to target localization. Each player yields a noisy response to a
binary query governed by a certain error probability. First, we propose a
sequential policy for constructing questions that queries each player in
sequence and refines the posterior of the target location. Second, we consider
a joint policy that asks all players questions in parallel at each time instant
and characterize the structure of the optimal policy for constructing the
sequence of questions. This generalizes the single player probabilistic
bisection method for stochastic search problems. Third, we prove an equivalence
between the two schemes showing that, despite the fact that the sequential
scheme has access to a more refined filtration, the joint scheme performs just
as well on average. Fourth, we establish convergence rates of the mean-square
error (MSE) and derive error exponents. Lastly, we obtain an extension to the
case of unknown error probabilities. This framework provides a mathematical
model for incorporating a human in the loop for active machine learning
systems.


title: Principal angles and approximation for quaternionic projections

abstract:
  We extend Jordan's notion of principal angles to work for two subspaces of
quaternionic space, and so have a method to analyze two orthogonal projections
in M_n(A) for A the real, complex or quaternionic field (or skew field). From
this we derive an algorithm to turn almost commuting projections into commuting
projections that minimizes the sum of the displacements of the two projections.
We quickly prove what we need using the universal real C*-algebra generated by
two projections.


title:
Micro-Pattern Gas Detectors for Charged-Particle Tracking and Muon
  Detection

abstract:
  In the context of the 2013 APS-DPF Snowmass summer study conducted by the
U.S. HEP community, this white paper outlines a roadmap for further development
of Micro-pattern Gas Detectors for tracking and muon detection in HEP
experiments. We briefly discuss technical requirements and summarize current
capabilities of these detectors with a focus of operation in experiments at the
energy frontier in the medium-term to long-term future. Some key directions for
future R&D on Micro-pattern Gas Detectors in the U.S. are suggested.


title:
Observation of Quantum Spin Hall States in InAs/GaSb Bilayers under
  Broken Time-Reversal Symmetry

abstract:
  Topological insulators (TIs) are a novel class of materials with nontrivial
surface or edge states. Time-reversal symmetry (TRS) protected TIs are
characterized by the Z2 topological invariant and their helical property
becomes lost in an applied magnetic field. Currently there exist extensive
efforts searching for TIs that are protected by symmetries other than TRS. Here
we show, a topological phase characterized by a spin Chern topological
invariant is realized in an inverted electron-hole bilayer engineered from
indium arsenide-gallium antimonide (InAs/GaSb) semiconductors which retains
robust helical edges under a strong magnetic field. Wide conductance plateaus
of 2e2/h value are observed; they persist to 12T applied in-plane magnetic
field without evidence for transition to a trivial insulator. In a
perpendicular magnetic field up to 8T, there exists no signature to the bulk
gap closing. While the Fermi energy remains inside the bulk gap, the
longitudinal conductance increases from 2e2/h in strong magnetic fields
suggesting a trend towards chiral edge transport. Our findings are first
evidences for a quantum spin Hall (QSH) insulator protected by a spin Chern
invariant. These results demonstrate that InAs/GaSb bilayers are a novel system
for engineering the robust helical edge channels much needed for spintronics
and for creating and manipulating Majorana particles in solid state.


title: Incremental Network Design with Minimum Spanning Trees

abstract:
  Given an edge-weighted graph $G=(V,E)$ and a set $E_0\subset E$, the
incremental network design problem with minimum spanning trees asks for a
sequence of edges $e'_1,\ldots,e'_T\in E\setminus E_0$ minimizing
$\sum_{t=1}^Tw(X_t)$ where $w(X_t)$ is the weight of a minimum spanning tree
$X_t$ for the subgraph $(V,E_0\cup\{e'_1,\ldots,e'_t\})$ and $T=\lvert
E\setminus E_0\rvert$. We prove that this problem can be solved by a greedy
algorithm.


title: Learning About Meetings

abstract:
  Most people participate in meetings almost every day, multiple times a day.
The study of meetings is important, but also challenging, as it requires an
understanding of social signals and complex interpersonal dynamics. Our aim
this work is to use a data-driven approach to the science of meetings. We
provide tentative evidence that: i) it is possible to automatically detect when
during the meeting a key decision is taking place, from analyzing only the
local dialogue acts, ii) there are common patterns in the way social dialogue
acts are interspersed throughout a meeting, iii) at the time key decisions are
made, the amount of time left in the meeting can be predicted from the amount
of time that has passed, iv) it is often possible to predict whether a proposal
during a meeting will be accepted or rejected based entirely on the language
(the set of persuasive words) used by the speaker.


title:
A Light-Weight Distributed System for the processing of Replicated
  Counter-like Objects

abstract:
  In order to increase availability in a distributed system some or all of the
data items are replicated and stored at separate sites. This is an issue of key
concern especially since there is such a proliferation of wireless technologies
and mobile users. However, the concurrent processing of transactions at
separate sites can generate inconsistencies in the stored information. We have
built a distributed service that manages updates to widely deployed
counter-like replicas. There are many heavy-weight distributed systems
targeting large information critical applications. Our system is intentionally,
relatively lightweight and useful for the somewhat reduced information critical
applications. The service is built on our distributed concurrency control
scheme which combines optimism and pessimism in the processing of transactions.
The service allows a transaction to be processed immediately (optimistically)
at any individual replica as long as the transaction satisfies a cost bound.
All transactions are also processed in a concurrent pessimistic manner to
ensure mutual consistency.


title:
Representation theorem for generators of BSDEs driven by G-Brownian
  motion and its applications

abstract:
  We obtain a representation theorem for the generators of BSDEs driven by
G-Brownian motions, and then we use the representation theorem to get a
converse comparison theorem for G-BSDEs and some equivalent results for
nonlinear expectations generated by G-BSDEs.


title: Correlation Functions of the SU(infinity) Principal Chiral Model

abstract:
  We obtain exact matrix elements of physical operators of the
(1+1)-dimensional nonlinear sigma model of an SU(N)-valued bare field, in the
't Hooft limit N goes to infinity. Specifically, all the form factors of the
Noether current and the stress-energy-momentum tensor are found with an
integrable bootstrap method. These form factors are used to find vacuum
expectation values of products of these operators.


title:
0-Hecke algebra action on the Stanley-Reisner ring of the Boolean
  algebra

abstract:
  We define an action of the 0-Hecke algebra of type A on the Stanley-Reisner
ring of the Boolean algebra. By studying this action we obtain a family of
multivariate noncommutative symmetric functions, which specialize to the
noncommutative Hall-Littlewood symmetric functions and their (q,t)-analogues
introduced by Bergeron and Zabrocki, and to a more general family of
noncommutative symmetric functions having parameters associated with paths in
binary trees introduced recently by Lascoux, Novelli, and Thibon. We also
obtain multivariate quasisymmetric function identities, which specialize to
results of Garsia and Gessel on generating functions of multivariate
distributions of permutation statistics.


title: Finite temperature Mott transition in a nonlocal PNJL model

abstract:
  We provide a novel calculation of the Mott effect in non-local PNJL models.
We find that the "deconfinement" transition temperature in these models is
lower than the Mott temperature. Furthermore, the mass and the width of the
$\sigma$ and the $\pi$ meson modes is calculated with the result that the width
in nonlocal models is in general reduced as compared to local models.
Difficulties encountered while attempting to "Wick rotate" covariant models are
carefully discussed.


title:
Testing the effects of gravity and motion on quantum entanglement in
  space-based experiments

abstract:
  We propose an experiment to test the effects of gravity and acceleration on
quantum entanglement in space-based setups. We show that the entanglement
between excitations of two Bose-Einstein condensates is degraded after one of
them undergoes a change in the gravitational field strength. This prediction
can be tested if the condensates are initially entangled in two separate
satellites while being in the same orbit and then one of them moves to a
different orbit. We show that the effect is observable in a typical orbital
manoeuvre of nanosatellites like CanX4 and CanX5.


title:
Derivation of the Dirac Equation from Principles of Information
  Processing

abstract:
  We show how the Dirac equation in three space-dimensions emerges from the
large-scale dynamics of the minimal nontrivial quantum cellular automaton
satisfying unitariety, locality, homogeneity, and discrete isotropy, without
using the relativity principle. The Dirac equation is recovered for small
wave-vector and inertial mass, whereas Lorentz covariance is distorted in the
ultra-relativistic limit. The automaton can thus be regarded as a theory
unifying scales from Planck to Fermi. A simple asymptotic approach leads to a
dispersive Schroedinger equation describing the evolution of narrow-band states
at all scales.


title:
On pseudocompact topological Brandt $\lambda^0$-extensions of
  semitopological monoids

abstract:
  In the paper we investigate topological properties of a topological Brandt
$\lambda^0$-extension $B^0_{\lambda}(S)$ of a semitopological monoid $S$ with
zero. In particular we prove that for every Tychonoff pseudocompact (resp.,
Hausdorff countably compact, Hausdorff compact) semitopological monoid $S$ with
zero there exists a unique semiregular pseudocompact (resp., Hausdorff
countably compact, Hausdorff compact) extension $B^0_{\lambda}(S)$ of $S$ and
establish theirs Stone-\v{C}ech and Bohr compactifications. We also describe a
category whose objects are ingredients in the constructions of pseudocompact
(resp., countably compact, sequentially compact, compact) topological Brandt
$\lambda^0$-extensions of pseudocompact (resp., countably compact, sequentially
compact, compact) semitopological monoids with zeros.


title:
On principles between $\Sigma_1$- and $\Sigma_2$-induction, and monotone
  enumerations

abstract:
  We show that many principles of first-order arithmetic, previously only known
to lie strictly between $\Sigma_1$-induction and $\Sigma_2$-induction, are
equivalent to the well-foundedness of $\omega^\omega$.
  Among these principles are the iteration of partial functions ($P\Sigma_1$)
of H\'ajek and Paris, the bounded monotone enumerations principle
(non-iterated, BME$_1$) by Chong, Slaman, and Yang, the relativized
Paris-Harrington principle for pairs, and the totality of the relativized
Ackermann-P\'eter function.
  With this we show that the well-foundedness of $\omega^\omega$ is a far more
widespread than usually suspected.
  Further, we investigate the $k$-iterated version of the bounded monotone
iterations principle (BME$_k$), and show that it is equivalent to the
well-foundedness of the $k+1$-height $\omega$-tower.


title: Does the first part of the second law also imply its second part?

abstract:
  Sommerfeld called the first part of the second law to be the entropy axiom,
which is about the existence of the state function entropy. It was usually
thought that the second part of the second law, which is about the
non-decreasing nature of entropy of thermally isolated systems, did not follow
from the first part. In this note, we point out the surprise that the first
part in fact implies the second part.


title: Evolutionary accessibility of modular fitness landscapes

abstract:
  A fitness landscape is a mapping from the space of genetic sequences, which
is modeled here as a binary hypercube of dimension $L$, to the real numbers. We
consider random models of fitness landscapes, where fitness values are assigned
according to some probabilistic rule, and study the statistical properties of
pathways to the global fitness maximum along which fitness increases
monotonically. Such paths are important for evolution because they are the only
ones that are accessible to an adapting population when mutations occur at a
low rate. The focus of this work is on the block model introduced by A.S.
Perelson and C.A. Macken [Proc. Natl. Acad. Sci. USA 92:9657 (1995)] where the
genome is decomposed into disjoint sets of loci (`modules') that contribute
independently to fitness, and fitness values within blocks are assigned at
random. We show that the number of accessible paths can be written as a product
of the path numbers within the blocks, which provides a detailed analytic
description of the path statistics. The block model can be viewed as a special
case of Kauffman's NK-model, and we compare the analytic results to simulations
of the NK-model with different genetic architectures. We find that the mean
number of accessible paths in the different versions of the model are quite
similar, but the distribution of the path number is qualitatively different in
the block model due to its multiplicative structure. A similar statement
applies to the number of local fitness maxima in the NK-models, which has been
studied extensively in previous works. The overall evolutionary accessibility
of the landscape, as quantified by the probability to find at least one
accessible path to the global maximum, is dramatically lowered by the modular
structure.


title:
A critique of Sadi Carnot's work and a mathematical theory of the
  caloric

abstract:
  In this work, Sadi Carnot;s fundamental work is critically examined, and
contrasted with modern thermodynamics. A mathematical theory of his work is
given on the basis of the observation that in caloric theory dQ is a perfect
differential.


title: Evidence for Helical Nuclear Spin Order in GaAs Quantum Wires

abstract:
  We present transport measurements of cleaved edge overgrowth GaAs quantum
wires. The conductance of the first mode reaches 2 e^2/h at high temperatures T
> 10 K, as expected. As T is lowered, the conductance is gradually reduced to 1
e^2/h, becoming T-independent at T < 0.1 K, while the device cools far below
0.1 K. This behavior is seen in several wires, is independent of density, and
not altered by moderate magnetic fields B. The conductance reduction by a
factor of two suggests lifting of the electron spin degeneracy in absence of B.
Our results are consistent with theoretical predictions for helical nuclear
magnetism in the Luttinger liquid regime.


title: Very Special Relativity and Lorentz Violating Theories

abstract:
  Very special relativity (VSR) keeps the main features of special relativity
but breaks rotational invariance. It can not be regarded as a fundamental
symmetry of nature because many observed phenomena depend on the existence of
Lorentz boosts. However, within the scope of Lorentz violating theories it can
have a role since it is breaking Lorentz symmetry in a very mild way. In this
context, when VSR terms are incorporated in a Lorentz invariant theory several
possibilities are allowed. In order to generate such terms systematically we
start with a formulation for a spinning particle in VSR. It is then coupled
minimally to the electromagnetic field and a gyromagnetic factor is added to
give rise to a magnetic moment. In order to analyze the effects of VSR in
Thomas precession a spin vector is then proposed in terms of the spinning
particle variables. It is then found the VSR contributions to the equation
which determines the spin precession angular velocity.


title:
Analytic solution of nonlinear fractional Burgers-type equation by
  invariant subspace method

abstract:
  In this paper we study the analytic solutions of Burgers-type nonlinear
fractional equations by means of the Invariant Subspace Method. We first study
a class of nonlinear equations directly related to the time-fractional Burgers
equation. Some generalizations linked to the forced time-fractional Burgers
equations and variable-coefficient diffusion are also considered. Finally we
study a Burgers-type equation involving both space and time-fractional
derivatives.


title: Dark Energy From Fifth Dimensional Brans-Dicke Theory

abstract:
  Following the approach of the induced-matter theory, we investigate the
cosmological implications of a five-dimensional Brans-Dicke theory, and propose
to explain the acceleration of the universe. After inducing in a
four-dimensional hypersurface, we classify the energy-momentum tensor into two
parts in a way that, one part represents all kind of the matter (the baryonic
and dark) and the other one contains every extra terms emerging from the scale
factor of the fifth dimension and the scalar field, which we consider as the
energy-momentum tensor of dark energy. We also separate the energy-momentum
conservation equation into two conservation equations, one for matter and the
other for dark energy. We perform this procedure for different cases, without
interacting term and with two particular (suitable) interacting terms between
the two parts. By assuming the parameter of the state equation for dark energy
to be constant, the equations of the model admit the power-law solutions.
Though, the non-interacting case does not give any accelerated universe, but
the interacting cases give both decelerated and accelerated universes. For the
interacting cases, we figure out analytically the acceptable ranges of some
parameters of the model, and also investigate the data analysis to test the
model parameter values consistency with the observational data of the distance
modulus of 580 SNe Ia compiled in Union2.1. For one of these interacting cases,
the best fitted values suggest that the Brans-Dicke coupling constant
({\omega}) is -7.75, however, it also gives the state parameter of dark energy
(wX) equal to -0.67. In addition, the model gives the Hubble and deceleration
parameters at the present time to be H0 = 69.4 (km/s)/Mpc and q0 = -0.38
(within their confidence intervals), where the scale factor of the fifth
dimension shrinks with the time.


title:
Systematic Effective Field Theory Analysis of the D=2+1 Quantum XY Model
  at Low Temperatures

abstract:
  The low-temperature properties of the (2+1)-dimensional quantum XY model are
studied within the framework of effective Lagrangians up to three-loop order.
At zero temperature, the system is characterized by a spontaneously broken spin
rotation symmetry, O(2) $\to$ 1, where the corresponding Goldstone bosons are
the spin waves or magnons. Even though there is no spontaneously broken order
at finite $T$, the low-temperature behavior of the system is still governed by
the spin waves. The partition function is evaluated and various thermodynamic
quantities, including the order parameter, are derived in the presence of a
weak external field. In particular, we show that the spin-wave interaction is
repulsive at low temperatures, its magnitude depending on the strength of the
external field. We compare our results with those for the (2+1)-dimensional
antiferromagnetic Heisenberg model which, at T=0, exhibits the spontaneously
broken spin rotation symmetry O(3) $\to$ O(2).


title: Automatic Abstraction in SMT-Based Unbounded Software Model Checking

abstract:
  Software model checkers based on under-approximations and SMT solvers are
very successful at verifying safety (i.e. reachability) properties. They
combine two key ideas -- (a) "concreteness": a counterexample in an
under-approximation is a counterexample in the original program as well, and
(b) "generalization": a proof of safety of an under-approximation, produced by
an SMT solver, are generalizable to proofs of safety of the original program.
In this paper, we present a combination of "automatic abstraction" with the
under-approximation-driven framework. We explore two iterative approaches for
obtaining and refining abstractions -- "proof based" and "counterexample based"
-- and show how they can be combined into a unified algorithm. To the best of
our knowledge, this is the first application of Proof-Based Abstraction,
primarily used to verify hardware, to Software Verification. We have
implemented a prototype of the framework using Z3, and evaluate it on many
benchmarks from the Software Verification Competition. We show experimentally
that our combination is quite effective on hard instances.


title: Nagy-Soper subtraction: a review

abstract:
  In this document, we present a review on an alternative NLO subtraction
scheme, based on the splitting kernels of an improved parton shower that
promises to facilitate the inclusion of higher order corrections into Monte
Carlo event generators. We give expressions for the scheme for massless
emitters, and point to work on the extension for massive cases. As an example,
we show results for the C parameter of the process e+ e- -> 3 jets at NLO which
have recently been published as a verification of this scheme. We equally
provide analytic expressions for integrated counterterms that have not been
presented in previous work, and comment on the possibility of analytic
approximations for the remaining numerical integrals


title: Detecting Useless Transitions in Pushdown Automata

abstract:
  Pushdown automata may contain transitions that are never used in any
accepting run of the automaton. We present an algorithm for detecting such
useless transitions. A finite automaton that captures the possible stack
content during runs of the pushdown automaton, is first constructed in a
forward procedure to determine which transitions are reachable, and then
employed in a backward procedure to determine which of these transitions can
lead to a final stat


title:
Link between quantum measurement and the i\epsilon\ term in the QFT
  propagator

abstract:
  Mensky has suggested to account for "continuous measurement" by attaching to
a path integral a weight function centered around the classical path that the
integral assigns a probability amplitude to. We show that in fact this weight
function doesn't have to be viewed as an additional ingredient put in by hand.
It can be derived instead from the conventional path integral if the
infinitesimal term i\epsilon\ in the propagator is made finite; the "classical
trajectory" is proportional to the current.


title:
A connection between anomalous Poisson-Nernst-Planck models and
  equivalent circuits with constant--phase elements

abstract:
  A connection between the impedance spectroscopy response of anomalous
Poisson-Nernst-Planck (PNPA) diffusional models and of equivalent circuits
containing constant phase elements (CPE) is established for a typical
electrolytic cell. The analysis is carried out in the limit of low frequency in
order to highlight the surface effects and to explore how they can be connected
to the presence of CPE in the circuit. It is shown that, depending on the
choice of the equivalent circuit, the action of these elements can be the same
as the one obtained by using integro-differential boundary conditions to
describe anomalous diffusive processes in the framework of PNPA models. The
predictions are also compared with an experimental data obtained from an
electrolytic solution.


title:
Reconstructing an atomic orthomodular lattice from the poset of its
  Boolean sublattices

abstract:
  We show that an atomic orthomodular lattice L can be reconstructed up to
isomorphism from the poset B(L) of Boolean subalgebras of L. A motivation comes
from quantum theory and the so-called topos approach, where one considers the
poset of Boolean sublattices of L=P(H), the projection lattice of the algebra
B(H) of bounded operators on Hilbert space.


title: Gauge Theory for Spectral Triples and the Unbounded Kasparov Product

abstract:
  We explore factorizations of noncommutative Riemannian spin geometries over
commutative base manifolds in unbounded KK-theory. After setting up the general
formalism of unbounded KK-theory and improving upon the construction of
internal products, we arrive at a natural bundle-theoretic formulation of gauge
theories arising from spectral triples. We find that the unitary group of a
given noncommutative spectral triple arises as the group of endomorphisms of a
certain Hilbert bundle; the inner fluctuations split in terms of connections
on, and endomorphisms of, this Hilbert bundle. Moreover, we introduce an
extended gauge group of unitary endomorphisms and a corresponding notion of
gauge fields. We work out several examples in full detail, to wit Yang--Mills
theory, the noncommutative torus and the $\theta$-deformed Hopf fibration over
the two-sphere.


title: Stability of stationary solutions for nonintegrable peakon equations

abstract:
  The Camassa-Holm equation with linear dispersion was originally derived as an
asymptotic equation in shallow water wave theory. Among its many interesting
mathematical properties, which include complete integrability, perhaps the most
striking is the fact that in the case where linear dispersion is absent it
admits weak multi-soliton solutions - "peakons" - with a peaked shape
corresponding to a discontinuous first derivative. There is a one-parameter
family of generalized Camassa-Holm equations, most of which are not integrable,
but which all admit peakon solutions. Numerical studies reported by Holm and
Staley indicate changes in the stability of these and other solutions as the
parameter varies through the family.
  In this article, we describe analytical results on one of these bifurcation
phenomena, showing that in a suitable parameter range there are stationary
solutions - "leftons" - which are orbitally stable.


title: A Formal Approach To Firewalls Testing Techniques

abstract:
  Traditional technologies of firewall testing are overlooked. A new formalized
approach is presented. Recommendations on optimization of test procedures are
given.


title:
Some Convergence And Stability Results For The Kirk Multistep And
  Kirk-Sp Fixed Point Iterative Algorithms For Contractive-Like Operators In
  Normed Linear Spaces

abstract:
  The purpose of this paper is to introduce a new Kirk type iterative algorithm
called Kirk multistep iteration and to study its convergence. We also prove
some theorems related with the stability results for the Kirk-multistep and
Kirk-SP iterative processes by employing certain contractive-like operators.
Our results generalize and unify some other results in the literature.


title:
The Formal Metabasis For Conformity Assessment of Information Security
  Software and Hardware

abstract:
  An approach to the development of security test procedures for information
security controls is presented. The recommendations for optimizing the test
procedure are obtained


title: Rendezvous of Two Robots with Constant Memory

abstract:
  We study the impact that persistent memory has on the classical rendezvous
problem of two mobile computational entities, called robots, in the plane. It
is well known that, without additional assumptions, rendezvous is impossible if
the entities are oblivious (i.e., have no persistent memory) even if the system
is semi-synchronous (SSynch). It has been recently shown that rendezvous is
possible even if the system is asynchronous (ASynch) if each robot is endowed
with O(1) bits of persistent memory, can transmit O(1) bits in each cycle, and
can remember (i.e., can persistently store) the last received transmission.
This setting is overly powerful.
  In this paper we weaken that setting in two different ways: (1) by
maintaining the O(1) bits of persistent memory but removing the communication
capabilities; and (2) by maintaining the O(1) transmission capability and the
ability to remember the last received transmission, but removing the ability of
an agent to remember its previous activities. We call the former setting
finite-state (FState) and the latter finite-communication (FComm). Note that,
even though its use is very different, in both settings, the amount of
persistent memory of a robot is constant.
  We investigate the rendezvous problem in these two weaker settings. We model
both settings as a system of robots endowed with visible lights: in FState, a
robot can only see its own light, while in FComm a robot can only see the other
robot's light. We prove, among other things, that finite-state robots can
rendezvous in SSynch, and that finite-communication robots are able to
rendezvous even in ASynch. All proofs are constructive: in each setting, we
present a protocol that allows the two robots to rendezvous in finite time.


title: (c-)AND: A new graph model

abstract:
  In this document, we study the scope of the following graph model: each
vertex is assigned to a box in a metric space and to a representative element
that belongs to that box. Two vertices are connected by an edge if and only if
its respective boxes contain the opposite representative element. We focus our
study on the case where boxes (and therefore representative elements)
associated to vertices are spread in the Euclidean line. We give both, a
combinatorial and an intersection characterization of the model. Based on these
characterizations, we determine graph families that contain the model (e. g.,
boxicity 2 graphs) and others that the new model contains (e. g., rooted
directed path). We also study the particular case where each representative
element is the center of its respective box. In this particular case, we
provide constructive representations for interval, block and outerplanar
graphs. Finally, we show that the general and the particular model are not
equivalent by constructing a graph family that separates the two cases.


title: Software Testing Models Against Information Security Requirements

abstract:
  An overview and classification of software testing models are done.
Recommendations on the choice of models are proposed


title: Pattern Recognition and Revealing using Parallel Coordinates Plot

abstract:
  Parallel coordinates plot (PCP) is an excellent tool for multivariate
visualization and analysis, but it may fail to reveal inherent structures for
datasets with a large number of items. In this paper, we propose a suite of
novel clustering, dimension ordering and visualization techniques based on PCP,
to reveal and highlight hidden structures. First, we propose a continuous
spline based polycurves design to extract and classify different cluster
aspects of the data. Then, we provide an efficient and optimal correlation
based sorting technique to reorder coordinates, as a helpful visualization tool
for data analysis. Various results generated by our framework visually
represent much structure, trend and correlation information to guide the user,
and improve the efficacy of analysis, especially for complex and noisy
datasets.


title: Hermite-Hadamard type inequalities for GA-s-convex functions

abstract:
  In this paper, The author introduces the concepts of the GA-s-convex
functions in the first sense and second sense and establishes some integral
inequalities of Hermite-Hadamard type related to the GA-s-convex functions.


title:
Response to Comment on Repulsive contact interactions make jammed
  particulate systems inherently nonharmonic'

abstract:
  This is a response to the comment on our manuscript "Repulsive contact
interactions make jammed particulate systems inherently nonharmonic" (Physical
Review Letters 107 (2011) 078301) by C. P. Goodrich, A. J. Liu, and S. R.
Nagel.


title: Dynamics in hybrid complex systems of switches and oscillators

abstract:
  While considerable progress has been made in the analysis of large systems
containing a single type of coupled dynamical component (e.g., coupled
oscillators or coupled switches), systems containing diverse components (e.g.,
both oscillators and switches) have received much less attention. We analyze
large, hybrid systems of interconnected Kuramoto oscillators and Hopfield
switches with positive feedback. In this system, oscillator synchronization
promotes switches to turn on. In turn, when switches turn on they enhance the
synchrony of the oscillators to which they are coupled. Depending on the choice
of parameters, we find theoretically coexisting stable solutions with either
(i) incoherent oscillators and all switches permanently off, (ii) synchronized
oscillators and all switches permanently on, or (iii) synchronized oscillators
and switches that periodically alternate between the on and off states.
Numerical experiments confirm these predictions. We discuss how transitions
between these steady state solutions can be onset deterministically through
dynamic bifurcations or spontaneously due to finite-size fluctuations.


title: Notes on the pure spinor b ghost

abstract:
  In this work, a particular BRST-exact class of deformations of the b ghost in
the non-minimal pure spinor formalism is investigated and the impact of this
construction in the $\mathcal{N}=2$ $\hat{c}=3$ topological string algebra is
analysed. As an example, a subclass of deformations is explicitly shown, where
the U(1) current appears in a conventional form, involving only the ghost
number currents. Furthermore, a c ghost like composite field is introduced, but
with an unusual construction.


title:
Formation of Feshbach molecules in the presence of artificial spin-orbit
  coupling and Zeeman fields

abstract:
  We derive general conditions for the emergence of singlet Feshbach molecules
in the presence of artificial Zeeman fields for arbritary mixtures of Rashba
and Dresselhaus spin-orbit orbit coupling in two or three dimensions. We focus
on the formation of two-particle bound states resulting from interactions
between ultra-cold spin-1/2 fermions, under the assumption that interactions
are short-ranged and occur only in the s-wave channel. In this case, we
calculate explicitly binding energies of Feshbach molecules and analyze their
dependence on spin-orbit couplings, Zeeman fields, interactions and center of
mass momentum, paying particular attention to the experimentally relevant case
of spin-orbit couplings with equal Rashba and Dresselhaus (ERD) amplitudes.


title:
A Raman-induced Feshbach resonance in an effectively single-component
  Fermi gas

abstract:
  Ultracold gases of interacting spin-orbit coupled fermions are predicted to
display exotic phenomena such as topological superfluidity and its associated
Majorana fermions. Here, we experimentally demonstrate a route to
strongly-interacting single-component atomic Fermi gases by combining an s-wave
Feshbach resonance (giving strong interactions) and spin-orbit coupling
(creating an effective p-wave channel). We identify the Feshbach resonance by
its associated atomic loss feature and show that, in agreement with our
single-channel scattering model, this feature is preserved and shifted as a
function of the spin-orbit coupling parameters.


title: Fermionic Isocurvature Perturbations

abstract:
  Isocurvature perturbations in the inflationary literature typically involve
quantum fluctuations of bosonic field degrees of freedom. In this work, we
consider isocurvature perturbations from fermionic quantum fluctuations during
inflation. When a stable massive fermion is coupled to a non-conformal sector
different from the scalar metric perturbations, observably large amplitude
scale invariant isocurvature perturbations can be generated. In addition to the
computation of the isocurvature two-point function, an estimate of the local
non-Gaussianities is also given and found to be promising for observations in a
corner of the parameter space. The results provide a new class of cosmological
probes for theories with stable massive fermions. On the technical side, we
explicitly renormalize the composite operator in curved spacetime and show that
gravitational Ward identities play an important role in suppressing certain
contributions to the fermionic isocurvature perturbations.


title: Matrix Partitions of Split Graphs

abstract:
  Matrix partition problems generalize a number of natural graph partition
problems, and have been studied for several standard graph classes. We prove
that each matrix partition problem has only finitely many minimal obstructions
for split graphs. Previously such a result was only known for the class of
cographs. (In particular, there are matrix partition problems which have
infinitely many minimal chordal obstructions.) We provide (close) upper and
lower bounds on the maximum size of a minimal split obstruction. This shows for
the first time that some matrices have exponential-sized minimal obstructions
of any kind (not necessarily split graphs). We also discuss matrix partitions
for bipartite and co-bipartite graphs.


title: First-principles predicted low-energy structures of NaSc(BH4)4

abstract:
  According to previous interpretations of experimental data, sodium-scandium
double-cation borohydride NaSc(BH$_4$)$_4$ crystallizes in the crystallographic
space group $Cmcm$ where each sodium (scandium) atom is surrounded by six
scandium (sodium) atoms. A careful investigation of this phase based on
\textit{ab initio} calculations indicates that the structure is dynamically
unstable and gives rise to an energetically and dynamically more favorable
phase with $C222_1$ symmetry and nearly identical x-ray diffraction pattern. By
additionally performing extensive structural searches with the minima-hopping
method we discover a class of new low-energy structures exhibiting a novel
structural motif in which each sodium (scandium) atom is surrounded by four
scandium (sodium) atoms arranged at the corners of either a rectangle with
nearly equal sides or a tetrahedron. These new phases are all predicted to be
insulators with band gaps of $7.9-8.2$ eV. Finally, we estimate the influence
of these structures on the hydrogen-storage performance of NaSc(BH$_4$)$_4$.


title:
Momentum-independent reflectionless transmission in the non-Hermitian
  time-reversal symmetric system

abstract:
  We theoretically study the non-Hermitian systems, the non-Hermiticity of
which arises from the unequal hopping amplitude (UHA) dimers. The
distinguishing features of these models are that they have full real spectra if
all of the eigenvectors are time-reversal (T) symmetric rather than
parity-time-reversal (PT) symmetric, and that their Hermitian counterparts are
shown to be an experimentally accessible system, which have the same
topological structures as that of the original ones but modulated hopping
amplitudes within the unbroken region. Under the reflectionless transmission
condition, the scattering behavior of momentum-independent reflectionless
transmission (RT) can be achieved in the concerned non-Hermitian system. This
peculiar feature indicates that, for a certain class of non-Hermitian systems
with a balanced combination of the RT dimers, the defects can appear fully
invisible to an outside observer.


title:
High-dimensional Fused Lasso Regression using Majorization-Minimization
  and Parallel Processing

abstract:
  In this paper, we propose a majorization-minimization (MM) algorithm for
high-dimensional fused lasso regression (FLR) suitable for parallelization
using graphics processing units (GPUs). The MM algorithm is stable and flexible
as it can solve the FLR problems with various types of design matrices and
penalty structures within a few tens of iterations. We also show that the
convergence of the proposed algorithm is guaranteed. We conduct numerical
studies to compare our algorithm with other existing algorithms, demonstrating
that the proposed MM algorithm is competitive in many settings including the
two-dimensional FLR with arbitrary design matrices. The merit of GPU
parallelization is also exhibited.


title: Semiregular automorphisms of edge-transitive graphs

abstract:
  The polycirculant conjecture asserts that every vertex-transitive digraph has
a semiregular automorphism, that is, a nontrivial automorphism whose cycles all
have the same length. In this paper we investigate the existence of semiregular
automorphisms of edge-transitive graphs. In particular, we show that any
regular edge-transitive graph of valency three or four has a semiregular
automorphism.


title: Commutators of small rank and reducibility of operator semigroups

abstract:
  It is easy to see that if $\cG$ is a non-abelian group of unitary matrices,
then for no members $A$ and $B$ of $\cG$ can the rank of $AB-BA$ be one. We
examine the consequences of the assumption that this rank is at most two for a
general semigroup $\cS$ of linear operators. Our conclusion is that under
obviously necessary, but trivial, size conditions, $\cS$ is reducible. In the
case of a unitary group satisfying the hypothesis, we show that it is contained
in the direct sum $\cG_1\oplus\cG_2$ where $\cG_1$ is at most $3\times 3$ and
$\cG_2$ is abelian.


title: Semigroups of Partial Isometries

abstract:
  We study self-adjoint semigroups of partial isometries on a Hilbert space.
These semigroups coincide precisely with faithful representations of abstract
inverse semigroups. Groups of unitary operators are specialized examples of
self-adjoint semigroups of partial isometries. We obtain a general structure
result showing that every self-adjoint semigroup of partial isometries consists
of "generalized weighted composition" operators on a space of square-integrable
Hilbert-space valued functions. If the semigroup is irreducible and contains a
compact operator then the underlying measure space is purely atomic, so that
the semigroup is represented as "zero-unitary" matrices. In this case it is not
even required that the semigroup be self-adjoint.


title: On matrix semigroups bounded above and below

abstract:
  An irreducible norm closed semigroup of complex matrices is simultaneously
similar to a semigroup of partial isometries if and only if (a) the norms of
all nonzero members of it are uniformly bounded above and below, and (b) its
idempotents commute. This is a generalization of the well-known result on
bounded groups.


title:
Quantum nucleation of effective Minkowski spacetime in hyperbolic
  metamaterials based on high Tc superconductors

abstract:
  We demonstrate that high Tc superconductors exhibit hyperbolic metamaterial
behavior in the far infrared and THz frequency ranges. In the THz range the
hyperbolic behavior occurs only in the normal state, while no propagating modes
exist in the superconducting state. Wave equation, which describes propagation
of extraordinary light inside a hyperbolic metamaterial exhibits 2+1
dimensional Lorentz symmetry. The role of time in the corresponding effective
3D Minkowski spacetime is played by the spatial coordinate aligned
perpendicular to the copper oxide layers. Such superconductor-based hyperbolic
metamaterials exhibit a quantum phase transition at T=0, in which the effective
Minkowski spacetime arise in the mixed state of the superconductor at some
critical value of external magnetic field. Nucleation of Minkowski spacetime
occurs via formation of quantized Abrikosov vortices, so that these vortices
play the role of effective Minkowski spacetime quanta.


title:
Corrections on energy spectrum and scatterings for fast neutron
  radiography at NECTAR facility

abstract:
  Neutron spectrum and scattered neutrons caused distortions are major problems
in fast neutron radiography and should be considered for improving the image
quality. This paper puts emphasis on the removal of these image distortions and
deviations for fast neutron radiography performed at the NECTAR facility of the
research reactor FRM-II in Technische Universit\"at M\"unchen (TUM), Germany.
The NECTAR energy spectrum is analyzed and established to modify the influence
caused by neutron spectrum, as well as the Point Scattered Function (PScF)
simulated by the Monte-Carlo program MCNPX is used to evaluate scattering
effects from the object and improve images qualities. Good analysis results
prove the sounded effects of above two corrections.


title:
Fidelity-Commensurability Tradeoff in Joint Embedding of Disparate
  Dissimilarities

abstract:
  In various data settings, it is necessary to compare observations from
disparate data sources. We assume the data is in the dissimilarity
representation and investigate a joint embedding method that results in a
commensurate representation of disparate dissimilarities. We further assume
that there are "matched" observations from different conditions which can be
considered to be highly similar, for the sake of inference. The joint embedding
results in the joint optimization of fidelity (preservation of within-condition
dissimilarities) and commensurability (preservation of between-condition
dissimilarities between matched observations). We show that the tradeoff
between these two criteria can be made explicit using weighted raw stress as
the objective function for multidimensional scaling. In our investigations, we
use a weight parameter, $w$, to control the tradeoff, and choose match
detection as the inference task. Our results show weights that are optimal
(with respect to the inference task) are different than equal weights for
commensurability and fidelity and the proposed weighted embedding scheme
provides significant improvements in statistical power.