title: Evaluation of Uncertain Inference Models I: PROSPECTOR

abstract:
  This paper examines the accuracy of the PROSPECTOR model for uncertain
reasoning. PROSPECTOR's solutions for a large number of computer-generated
inference networks were compared to those obtained from probability theory and
minimum cross-entropy calculations. PROSPECTOR's answers were generally
accurate for a restricted subset of problems that are consistent with its
assumptions. However, even within this subset, we identified conditions under
which PROSPECTOR's performance deteriorates.


title: On Implementing Usual Values

abstract:
  In many cases commonsense knowledge consists of knowledge of what is usual.
In this paper we develop a system for reasoning with usual information. This
system is based upon the fact that these pieces of commonsense information
involve both a probabilistic aspect and a granular aspect. We implement this
system with the aid of possibility-probability granules.


title: On the Combinality of Evidence in the Dempster-Shafer Theory

abstract:
  In the current versions of the Dempster-Shafer theory, the only essential
restriction on the validity of the rule of combination is that the sources of
evidence must be statistically independent. Under this assumption, it is
permissible to apply the Dempster-Shafer rule to two or mere distinct
probability distributions.


title:
GUI Database for the Equipment Store of the Department of Geomatic
  Engineering, KNUST

abstract:
  The geospatial analyst is required to apply art, science, and technology to
measure relative positions of natural and man-made features above or beneath
the earths surface, and to present this information either graphically or
numerically. The reference positions for these measurements need to be well
archived and managed to effectively sustain the activities in the spatial
industry. The research herein described highlights the need for an information
system for the Land Surveyors Equipment Store. Such a system is a database
management system with a user friendly graphical interface. This paper
describes one such system that has been developed for the Equipment Store of
the Department of Geomatic Engineering, Kwame Nkrumah University of Science and
Technology, Ghana. The system facilitates efficient management and location of
instruments, as well as easy location of beacons together with their attribute
information, it provides multimedia information about instruments in an
Equipment Store. Digital camera was used capture the pictorial descriptions of
the beacons. Geographic Information System software was employed to visualize
the spatial location of beacons and to publish the various layers for the
Graphical User Interface. The aesthetics of the interface was developed with
user interface design tools and coded by programming. The developed Suite,
powered by a reliable and fully scalable database, provides an efficient way of
booking and analyzing transactions in an Equipment Store.


title: Decomposing Petri nets

abstract:
  In recent work, the second and third authors introduced a technique for
reachability checking in 1-bounded Petri nets, based on wiring decompositions,
which are expressions in a fragment of the compositional algebra of nets with
boundaries. Here we extend the technique to the full algebra and introduce the
related structural property of decomposition width on directed hypergraphs.
Small decomposition width is necessary for the applicability of the
reachability checking algorithm. We give examples of families of nets with
constant decomposition width and develop the underlying theory of
decompositions.


title: Planck 2013 results support the cyclic universe

abstract:
  We show that results from the Planck satellite reported in 2013 are
consistent with the simplest cyclic models for natural parameter ranges i.e.,
order unity dimensionless coefficients, assuming the standard entropic
mechanism for generating curvature perturbations. With improved precision,
forthcoming results from Planck and other experiments should be able to test
the parameter ranges by confirming or refuting the core predictions - i.e., no
observable primordial B-mode polarization and detectable local non-gaussianity.
A new prediction, given the Planck 2013 constraints on the bispectrum, is a
sharp constraint on the local trispectrum parameter g_{NL}; namely, the
simplest models predict it is negative, with g_{NL} < -1700.


title:
The binary companion mass ratio distribution: an imprint of the star
  formation process?

abstract:
  We explore the effects of dynamical evolution in dense clusters on the
companion mass ratio distribution (CMRD) of binary stars. Binary systems are
destroyed by interactions with other stars in the cluster, lowering the total
binary fraction and significantly altering the initial semi-major axis
distribution. However, the shape of the CMRD is unaffected by dynamics; an
equal number of systems with high mass ratios are destroyed compared to systems
with low mass ratios. We might expect a weak dependence of the survivability of
a binary on its mass ratio because its binding energy is proportional to both
the primary and secondary mass components of the system. However, binaries are
broken up by interactions in which the perturbing star has a significantly
higher energy (by a factor of >10, depending on the particular binary
properties) than the binding energy of the binary, or through multiple
interactions in the cluster. We therefore suggest that the shape of the
observed binary CMRD is an outcome of the star formation process, and should be
measured in preference to the distributions of orbital parameters, such as the
semi-major axis distribution.


title:
The impact of global environment on galaxy mass functions at low
  redshift

abstract:
  We study the galaxy stellar mass function in different environments in the
local Universe, considering both the total mass function and that of individual
galaxy morphological types. We compare the mass functions of galaxies with $\rm
log_{10} M_{\star}/M_{\odot} \geq 10.25$ in the general field and in galaxy
groups, binary and single galaxy systems from the Padova-Millennium Galaxy and
Group Catalogue at $z=0.04-0.1$ with the mass function of galaxy clusters of
the WIde-field Nearby Galaxy-Cluster Survey at $z=0.04-0.07$. Strikingly, the
variations of the mass function with global environment, overall, are small and
subtle. The shapes of the mass functions of the general field and clusters are
indistinguishable, and only small, statistically insignificant variations are
allowed in groups. Only the mass function of our single galaxies, representing
the least massive haloes and comprising less than a third of the general field
population, is proportionally richer in low-mass galaxies than other
environments. The most notable environmental effect is a progressive change in
the upper galaxy mass, with very massive galaxies found only in the most
massive environments. This environment-dependent mass cut-off is unable to
affect the Schechter parameters and the K-S test, and can only be revealed by
an ad-hoc analysis. Finally, we show how, in each given environment, the mass
function changes with morphological type, and that galaxies of the same
morphological type can have different mass functions in different environments.


title: Debris discs around M stars: non-existence versus non-detection

abstract:
  Motivated by the reported dearth of debris discs around M stars, we use
survival models to study the occurrence of planetesimal discs around them.
These survival models describe a planetesimal disc with a small number of
parameters, determine if it may survive a series of dynamical processes and
compute the associated infrared excess. For the WISE satellite, we demonstrate
that the dearth of debris discs around M stars may be attributed to the small
semi-major axes generally probed if either: 1. the dust grains behave like
blackbodies emitting at a peak wavelength coincident with the observed one; 2.
or the grains are hotter than predicted by their blackbody temperatures and
emit at peak wavelengths that are shorter than the observed one. At these small
distances from the M star, planetesimals are unlikely to survive or persist for
time scales of 300 Myr or longer if the disc is too massive. Conversely, our
survival models allow for the existence of a large population of low-mass
debris discs that are too faint to be detected with current instruments.
However, our interpretation becomes less clear and large infrared excesses are
allowed if only one of these scenarios holds: 3. the dust grains are hotter
than blackbody and predominantly emit at the observed wavelength; 4. or are
blackbody in nature and emit at peak wavelengths longer than the observed one.
Both scenarios imply that the parent planetesimals reside at larger distances
from the star than inferred if the dust grains behaved like blackbodies. In all
scenarios, we show that the infrared excesses detected at 22 and 70 microns
from AU Mic are easily reconciled with its young age. We elucidate the
conditions under which stellar wind drag may be neglected when considering dust
populations around M stars. The WISE satellite should be capable of detecting
debris discs around young M stars with ages on the order of 10 Myr.


title: Towards Holographic Spintronics

abstract:
  We study transport phenomena of total angular momentum in holography, as a
first step toward holographic understanding of spin transport phenomena. Spin
current, which has both the local Lorentz index for spins and the space-time
vector index for current, couples naturally to the bulk spin connection.
Therefore the bulk spin connection becomes the source for the boundary spin
current. This allows us to evaluate the spin current holographically, with a
relation to the stress tensor and metric fluctuations in the bulk. We examine
the spin transport coefficients and the thermal spin Hall conductivity in a
simple holographic setup.


title:
A New Approach to Identifying the Most Powerful Gravitational Lensing
  Telescopes

abstract:
  The best gravitational lenses for detecting distant galaxies are those with
the largest mass concentrations and the most advantageous configurations of
that mass along the line of sight. Our new method for finding such
gravitational telescopes uses optical data to identify projected concentrations
of luminous red galaxies (LRGs). LRGs are biased tracers of the underlying mass
distribution, so lines of sight with the highest total luminosity in LRGs are
likely to contain the largest total mass. We apply this selection technique to
the Sloan Digital Sky Survey and identify the 200 fields with the highest total
LRG luminosities projected within a 3.5' radius over the redshift range 0.1 < z
< 0.7. The redshift and angular distributions of LRGs in these fields trace the
concentrations of non-LRG galaxies. These fields are diverse; 22.5% contain one
known galaxy cluster and 56.0% contain multiple known clusters previously
identified in the literature. Thus, our results confirm that these LRGs trace
massive structures and that our selection technique identifies fields with
large total masses. These fields contain 2-3 times higher total LRG
luminosities than most known strong-lensing clusters and will be among the best
gravitational lensing fields for the purpose of detecting the highest redshift
galaxies.


title: Star Formation & Dust Heating in the FIR Bright Sources of M83

abstract:
  We investigate star formation and dust heating in the compact FIR bright
sources detected in the Herschel maps of M83. We use the source extraction code
GETSOURCES to detect and extract sources in the FIR, as well as their
photometry in the MIR and H{\alpha}. By performing infrared SED fitting and
applying an H{\alpha} based star formation rate (SFR) calibration, we derive
the dust masses and temperatures, SFRs, gas masses and star formation
efficiencies (SFEs). The detected sources lie exclusively on the spiral arms
and represent giant molecular associations (GMAs), with gas masses and sizes of
10^6-10^8 solar masses and 200-300 pc, respectively. The inferred parameters
show little to no radial dependence and there is only a weak correlation
between the SFRs and gas masses, which suggests that more massive clouds are
less efficient at forming stars. Dust heating is mainly due to local star
formation. However, although the sources are not optically thick, the total
intrinsic young stellar population luminosity can almost completely account for
the dust luminosity. This suggests that other radiation sources contribute to
the dust heating as well and approximately compensate for the unabsorbed
fraction of UV light.


title: Folding defect affine Toda field theories

abstract:
  A folding process is applied to fused a^(1)_r defects to construct defects
for the non-simply laced affine Toda field theories of c^(1)_n, d^(2)_n and
a^(2)_2n at the classical level. Support for the hypothesis that these defects
are integrable in the folded theories is provided by the observation that
transmitted solitons retain their form. Further support is given by the
demonstration that energy and momentum are conserved.


title: Striped Order in AdS/CFT

abstract:
  We study the formation of inhomogeneous order in the Einstein-Maxwell-axion
system, dual to a 2+1 dimensional field theory that exhibits a spontaneously
generated current density, momentum density and modulated scalar operator.
Below the critical temperature, the Reissner-Nordstrom-AdS black hole becomes
unstable and stripes form in the bulk and on the boundary. The bulk geometry
possesses striking geometrical features, including a modulated horizon that
tends to pinch off as T -> 0. On a domain of fixed length, we find a second
order phase transition to the striped solution in each of the grand canonical,
canonical and microcanonical ensembles, with modulated charges that grow and
saturate as we lower the temperature and descend into the inhomogeneous phase.
For the black hole on an infinite domain, a similar second order transition
occurs, and the width of the dominant stripe increases in the zero temperature
limit.


title:
The Effects of Radiative Transfer on the PDFs of Molecular MHD
  Turbulence

abstract:
  We study the effects of radiative transfer on the Probability Distribution
Functions (PDFs) of simulations of magnetohydrodynamic turbulence in the widely
studied $^{13}$CO 2-1 transition. We find that the integrated intensity maps
generally follow a log-normal distribution, with the cases that have $\tau
\approx 1$ best matching the PDF of the column density. We fit a 2D
variance-sonic Mach number relationship to our logarithmic PDFs of the form
$\sigma_{ln(\Sigma/\Sigma_0)}^2=A\times ln(1+b^2{\cal M}_s^2)$ and find that,
for parameter $b=1/3$, parameter $A$ depends on the radiative transfer
environment. We also explore the variance, skewness, and kurtosis of the linear
PDFs finding that higher moments reflect both higher sonic Mach number and
lower optical depth. Finally, we apply the Tsallis incremental PDF function and
find that the fit parameters depend on both Mach numbers, but also are
sensitive to the radiative transfer parameter space, with the $\tau \approx 1$
case best fitting the incremental PDF of the true column density. We conclude
that, for PDFs of low optical depth cases, part of the gas is always
sub-thermally excited so that the spread of the line intensities exceeds the
spread of the underlying column densities and hence the PDFs do not reflect the
true column density. Similarly, PDFs of optically thick cases are dominated by
the velocity dispersion and therefore do not represent the true column density
PDF. Thus, in the case of molecules like carbon monoxide, the dynamic range of
intensities, structures observed and consequently, the observable PDFs, are
less determined by turbulence and more-often determined by radiative transfer
effects.


title: The de Rham cohomology of Drinfeld's half space

abstract:
  Let X be Drinfeld's half space over a p-adic field K. The de Rham cohomology
of X was first computed by Schneider and Stuhler. Afterwards there were given
different proofs by Alon, de Shalit, Iovita and Spiess. This paper presents yet
another approach for the determination of these invariants by analysing the de
Rham complex of X from the viewpoint of recent results by the author.


title: Reconnection Diffusion, Star Formation and Numerical Simulations

abstract:
  We consider fast magnetic reconnection that takes place within turbulent
magnetic flux and show that the process results in diffusion of magnetic fields
and matter, which we term reconnection diffusion. The process of reconnection
diffusion is based on the model of 3D reconnection of weakly turbulent magnetic
fields and is applicable to both fully ionized and partially ionized gas. The
rate of reconnection diffusion does not depend on the level of ionization and
therefore the usually employed ambipolar diffusion idea gets irrelevant for
magnetic field transport in turbulent fluids. We claim that the reconnection
diffusion process is a manifestation of the violation of flux conservation in
highly conducting turbulent fluids. We discuss the consequences of reconnection
diffusion for star formation and stress. We show that reconnection diffusion on
large scales is independent of small scale magnetic field dynamics of magnetic
fields. We conclude that numerical simulations correctly represents the
diffusion of actual astrophysical magnetic fields in flows with substantially
larger Lundquist numbers if these simulated regions regions are turbulent.

categories: astro-ph.GA astro-ph.SR physics.plasm-ph physics.space-ph


title: TCLOUD: Challenges and Best Practices for Cloud Computing

abstract:
  Cloud computing has achieved an unbelievable adoption response rate but still
its infancy stage is not over. It is an emerging paradigm and amazingly gaining
popularity. The size of the market shared of the applications provided by cloud
computing is still not much behind the expectations. It provides the
organizations with great potential to minimize the cost and maximizes the
overall operating effectiveness of computing required by an organization.
Despite its growing popularity, still it is faced with security, privacy, and
portability issues, which in one or the other way create hurdles in the fast
acceptance of this new technology for the computing community. This paper
provides a concise all around analysis of the challenges faced by cloud
computing community and also presents the solutions available to these
challenges.


title: Maximizing Matching in Double-sided Auctions

abstract:
  In this paper, we introduce a novel, non-recursive, maximal matching
algorithm for double auctions, which aims to maximize the amount of commodities
to be traded. It differs from the usual equilibrium matching, which clears a
market at the equilibrium price. We compare the two algorithms through
experimental analyses, showing that the maximal matching algorithm is favored
in scenarios where trading volume is a priority and that it may possibly
improve allocative efficiency over equilibrium matching as well. A
parameterized algorithm that incorporates both maximal matching and equilibrium
matching as special cases is also presented to allow flexible control on how
much to trade in a double auction.


title: Effective Congruences for Mock Theta Functions

abstract:
  Let M(q)=\sum c(n) q^n be one of Ramanujan's mock theta functions. We
establish the existence of infinitely many linear congruences of the form
c(An+B) \equiv 0 (mod \ell^j), where A is a multiple of \ell and an auxiliary
prime p. Moreover, we give an effectively computable upper bound on the
smallest such p for which these congruences hold. The effective nature of our
results is based on prior works of Lichtenstein and Treneer.


title: Higher-derivative couplings in string theory: dualities and the B-field

abstract:
  The first quantum correction to the IIA string effective action arises at the
eight-derivative level and takes the schematic form (t_8 t_8 - 1/8
\epsilon\epsilon)R^4 + B_2 \wedge X_8. This correction, however, cannot be
complete by itself, as it is neither supersymmetric nor T-duality covariant. We
reexamine these eight-derivative couplings and conjecture that the simple
replacement R -> R(\Omega_+), where \Omega_+ = \Omega + 1/2 H is the connection
with torsion, nearly completely captures their dependence on the B-field. The
exception is in the odd-odd spin structure sector, where additional terms are
needed. We present here a complete result at the level of the five-point
function and a partial one for the six-point function. Further evidence for
this conjecture comes from considering T-duality as well as heterotic/IIA
duality beyond leading order. Finally, we discuss the eleven-dimensional lift
of the modified one-loop type IIA couplings.


title: Sustainable Cooperative Coevolution with a Multi-Armed Bandit

abstract:
  This paper proposes a self-adaptation mechanism to manage the resources
allocated to the different species comprising a cooperative coevolutionary
algorithm. The proposed approach relies on a dynamic extension to the
well-known multi-armed bandit framework. At each iteration, the dynamic
multi-armed bandit makes a decision on which species to evolve for a
generation, using the history of progress made by the different species to
guide the decisions. We show experimentally, on a benchmark and a real-world
problem, that evolving the different populations at different paces allows not
only to identify solutions more rapidly, but also improves the capacity of
cooperative coevolution to solve more complex problems.


title: The Complexity of Approximating Vertex Expansion

abstract:
  We study the complexity of approximating the vertex expansion of graphs $G =
(V,E)$, defined as \[ \Phi^V := \min_{S \subset V} n \cdot \frac{|N(S)|}{|S| |V
\backslash S|}. \]
  We give a simple polynomial-time algorithm for finding a subset with vertex
expansion $O(\sqrt{OPT \log d})$ where $d$ is the maximum degree of the graph.
Our main result is an asymptotically matching lower bound: under the Small Set
Expansion (SSE) hypothesis, it is hard to find a subset with expansion less
than $C\sqrt{OPT \log d}$ for an absolute constant $C$. In particular, this
implies for all constant $\epsilon > 0$, it is SSE-hard to distinguish whether
the vertex expansion $< \epsilon$ or at least an absolute constant. The
analogous threshold for edge expansion is $\sqrt{OPT}$ with no dependence on
the degree; thus our results suggest that vertex expansion is harder to
approximate than edge expansion. In particular, while Cheeger's algorithm can
certify constant edge expansion, it is SSE-hard to certify constant vertex
expansion in graphs.
  Our proof is via a reduction from the {\it Unique Games} instance obtained
from the \SSE hypothesis to the vertex expansion problem. It involves the
definition of a smoother intermediate problem we call {\sf Analytic Vertex
Expansion} which is representative of both the vertex expansion and the
conductance of the graph. Both reductions (from the UGC instance to this
problem and from this problem to vertex expansion) use novel proof ideas.


title:
On PROGRESS Operation. How to Make Object-Oriented Programming System
  More Object-Oriented (DRAFT)

abstract:
  A system, which implements persistent objects, has to provide different
opportunities to change the objects in arbitrary ways during their existence. A
traditional realization of OO paradigm in modern programming systems has
fundamental drawbacks which complicate an implementation of persistent
modifiable objects considerably. There is alternative realization that does not
have these drawbacks. In the article the PROGRESS operation is offered, which
modify existing object within an existing inheritance hierarchy.


title:
Advanced holographic nondestructive testing system for residual stress
  analysis

abstract:
  The design and operating of a portable holographic interferometer for
residual stress analysis by creating a small scratch along with a new
mathematical algorithm of calculations are discussed. Preliminary data of the
stress investigations on aluminum and steel alloys have been obtained by the
automatic processing of the interference pattern using a notebook computer. A
phase-shift compensation technique in real-time reflection interferometry is
used to measure the out-of-plane stress release surface displacement
surrounding a small scratch (25 um depth and 0.5 mm width) in a plate with
residual stress of around 50 MPa. Comparison between theoretical models for a
rectangular and triangular shaped scratch with the experimental data are
presented.


title: The Lick-Index Calibration of the GEMINI Multi-Object Spectrographs

abstract:
  We present the calibration of the spectroscopic Lick/IDS standard line-index
system for measurements obtained with the Gemini Multi-Object Spectrographs
known as GMOS-North and GMOS- South. We provide linear correction functions for
each of the 25 standard Lick line indices for the B600 grism and two
instrumental setups, one with 0.5 arcsecond slit width and 1x1 CCD pixel
binning (corresponding to ~2.5 Angstroem spectral resolution) and the other
with 0.75 arcsecond slit width and 2x2 binning (~4 Angstroem). We find small
and well-defined correction terms for the set of Balmer indices Hbeta, HgammaA,
and HdeltaA along with the metallicity sensitive indices Fe5015, Fe5270,
Fe5335, Fe5406, Mg2 and Mgb that are widely used for stellar population
diagnostics of distant stellar systems. We find other indices that sample
molecular absorption bands, such as TiO1 and TiO2, with very wide wavelength
coverage or indices that sample very weak molecular and atomic absorption
features, such as Mg1, as well as indices with particularly narrow passband
definitions, such as Fe4384, Ca4455, Fe4531, Ca4227, and Fe5782, less robustly
calibrated. These indices should be used with caution.


title:
A Novel Construction of Complex-valued Gaussian Processes with Arbitrary
  Spectral Densities and its Application to Excitation Energy Transfer

abstract:
  The recent experimental discoveries about excitation energy transfer (EET) in
light harvesting antenna (LHA) attract a lot of interest. As an open
non-equilibrium quantum system, the EET demands more rigorous theoretical
framework to understand the interaction between system and environment and
therein the evolution of reduced density matrix. A phonon is often used to
model the fluctuating environment and convolutes the reduced quantum system
temporarily. In this paper, we propose a novel way to construct complex-valued
Gaussian processes to describe thermal quantum phonon bath exactly by
converting the convolution of influence functional into the time correlation of
complex Gaussian random field. Based on the construction, we propose a rigorous
and efficient computational method, the covariance decomposition (CD) and
conditional propagation scheme, to simulate the temporarily entangled reduced
system.
  The new method allows us to study the non-Markovian effect without
perturbation under the influence of different spectral densities of the linear
system-phonon coupling coefficients. Its application in the study of EET in the
Fenna-Matthews-Olson (FMO) model Hamiltonian under four different spectral
densities is discussed. Since the scaling of our algorithm is linear due to its
Monte Carlo nature, the future application of the method for large LHA systems
is attractive. In addition, this method can be used to study the effect of
correlated initial condition on the reduced dynamics in the future.


title: Logical Probability Preferences

abstract:
  We present a unified logical framework for representing and reasoning about
both probability quantitative and qualitative preferences in probability answer
set programming, called probability answer set optimization programs. The
proposed framework is vital to allow defining probability quantitative
preferences over the possible outcomes of qualitative preferences. We show the
application of probability answer set optimization programs to a variant of the
well-known nurse restoring problem, called the nurse restoring with probability
preferences problem. To the best of our knowledge, this development is the
first to consider a logical framework for reasoning about probability
quantitative preferences, in general, and reasoning about both probability
quantitative and qualitative preferences in particular.


title: Exact Algorithms for Weighted and Unweighted Borda Manipulation Problems

abstract:
  Both weighted and unweighted Borda manipulation problems have been proved
$\mathcal{NP}$-hard. However, there is no exact combinatorial algorithm known
for these problems. In this paper, we initiate the study of exact combinatorial
algorithms for both weighted and unweighted Borda manipulation problems. More
precisely, we propose $O^*((m\cdot 2^m)^{t+1})$time and
$O^*(t^{2m})$time\footnote{$O^*()$ is the $O()$ notation with suppressed
factors polynomial in the size of the input.} combinatorial algorithms for
weighted and unweighted Borda manipulation problems, respectively, where $t$ is
the number of manipulators and $m$ is the number of candidates. Thus, for $t=2$
we solve one of the open problems posted by Betzler et al. [IJCAI 2011]. As a
byproduct of our results, we show that the {{unweighted Borda manipulation}}
problem admits an algorithm of running time $O^*(2^{9m^2\log{m}})$, based on an
integer linear programming technique. Finally, we study the {{unweighted Borda
manipulation}} problem under single-peaked elections and present
polynomial-time algorithms for the problem in the case of two manipulators, in
contrast to the $\mathcal{NP}$-hardness of this case in general settings.


title: Standardized network reconstruction of CHO cell metabolism

abstract:
  We have created a genome-scale network reconstruction of chinese hamster
ovary (CHO) cell metabolism. Existing reconstructions were improved in terms of
annotation standards, to facilitate their subsequent use in dynamic modelling.
The resultant network is available from ChoNet (http://cho.sf.net/).


title: Packing and Self-assembly of Truncated Triangular Bipyramids

abstract:
  Motivated by breakthroughs in the synthesis of faceted nano- and colloidal
particles, as well as theoretical and computational studies of their packings,
we investigate a family of truncated triangular bipyramids. We report dense
periodic packings with small unit cells that were obtained via numerical and
analytical optimization. The maximal packing fraction $\phi_{\max}$ changes
continuously with the truncation parameter $t$. Eight distinct packings are
identified based on discontinuities in the first and second derivatives of
$\phi_{\max}(t)$. These packings differ in the number of particles in the
fundamental domain (unit cell) and the type of contacts between the particles.
In particular, we report two packings with four particles in the unit cell for
which both $\phi_{\max}(t)$ and $\phi'_{\max}(t)$ are continuous and the
discontinuity occurs in the second derivative only. In the self-assembly
simulations that we perform for larger boxes with 2048 particles, only one out
of eight packings is found to assemble. In addition, the degenerate
quasicrystal reported previously for triangular bipyramids without truncation
[{http://prl.aps.org/abstract/PRL/v107/i21/e215702}{Haji-Akbari \emph{et al.},
\emph{Phys. Rev. Lett.} \textbf{107}: 215702 (2011)}] assembles for truncations
as high as 0.45. The self-assembly propensities for the structures formed in
the thermodynamic limit are explained using the isoperimetric quotient of the
particles and the coordination number in the disordered fluid and in the
assembled structure.


title: A Toolkit of the Stop Search via the Chargino Decay

abstract:
  The top squark (stop) may dominantly decay to a bottom quark and a chargino
if the mass difference between the stop and the lightest neutralino is
comparable or less than the top quark mass. Such a moderately compressed
spectrum is a challenging scenario for the stop search at the Large Hadron
Collider, because it is difficult to separate the signals from the top and
anti-top background. In this paper we focus on the di-leptonic decay channel,
and consider many kinematic variables as possible discriminators. These include
several MT2 variables and new "compatible-masses" variables which fully utilize
all kinematic information of the background. We use several sample spectra with
different characteristics to study the efficiencies of these variables in
distinguishing the signal from the background. The finding is that different
combinations of variables or strategies should be used for different spectra to
maximally enhance the signal significance and expand the reach of the stop
search in this scenario. The new variables that we proposed in this paper are
also useful for other new physics searches with di-leptonic top and anti-top
events as the dominant background.


title: Counting bats

abstract:
  We demonstrate an algorithm that reconstructs the number of walkers in an
unknown graph from observations of their returns to a fixed point.


title:
On the $L^p$-estimates of Riesz transforms on forms over complete
  Riemanian manifolds

abstract:
  In our previous paper \cite{Li2010}, we proved a martingale transform
representation formula for the Riesz transforms on forms over complete
Riemannian manifolds, and proved some explicit $L^p$-norm estimates for the
Riesz transforms on complete Riemannian manifolds with suitable curvature
conditions. In this paper we correct a gap contained in \cite{Li2010} and prove
that the main result obtained in \cite{Li2010} on the $L^p$-norm estimates for
the Riesz transforms on forms remain valid. Moreover, we prove a time reversal
martingale transform representation formula for the Riesz transforms on forms.
Finally, we extend our approach and result to the Riesz transforms acting on
Euclidean vector bundles over complete Riemannian manifolds with suitable
curvature conditions.


title:
Solar Cycle Propagation, Memory, and Prediction: Insights from a Century
  of Magnetic Proxies

abstract:
  The solar cycle and its associated magnetic activity are the main drivers
behind changes in the interplanetary environment and the Earth's upper
atmosphere (commonly referred to as space weather). These changes have a direct
impact on the lifetime of space-based assets and can create hazards to
astronauts in space. In recent years there has been an effort to develop
accurate solar cycle predictions (with aims at predicting the long-term
evolution of space weather), leading to nearly a hundred widely spread
predictions for the amplitude of solar cycle 24. A major contributor to the
disagreement is the lack of direct long-term databases covering different
components of the solar magnetic field (toroidal vs.\ poloidal). Here we use
sunspot area and polar faculae measurements spanning a full century (as our
toroidal and poloidal field proxies), to study solar cycle propagation, memory,
and prediction. Our results substantiate predictions based on the polar
magnetic fields, whereas we find sunspot area to be uncorrelated to cycle
amplitude unless multiplied by area-weighted average tilt. This suggests that
the joint assimilation of tilt and sunspot area is a better choice (with aims
to cycle prediction) than sunspot area alone, and adds to the evidence in favor
of active region emergence and decay as the main mechanism of poloidal field
generation (i.e. the Babcock-Leighton mechanism). Finally, by looking at the
correlation between our poloidal and toroidal proxies across multiple cycles,
we find solar cycle memory to be limited to only one cycle.


title:
Greatly Enhanced Eccentricity Oscillations in Quadruple Systems Composed
  of Two Binaries: Implications for Stars, Planets, and Transients

abstract:
  We study the orbital evolution of hierarchical quadruple systems composed of
two binaries on a long mutual orbit, where each binary acts as a Kozai-Lidov
(KL) perturber on the other. We find that the coupling between the two binaries
qualitatively changes the behavior of their KL cycles. The binaries can
experience coherent eccentricity oscillations as well as excursions to very
high eccentricity that occur over a much larger fraction of the parameter space
than in triple systems. For a ratio of outer to inner semi-major axes of 10 to
20, about 30 to 50% of equal-mass quadruples reach eccentricity 1-e < 10^{-3}
in one of the binaries. This is about 4 to 12 times more than for triples with
equivalent parameters. Orbital "flips" and collisions without previous tidal
interaction are similarly enhanced in quadruples relative to triples. We argue
that the frequency of evolutionary paths influenced by KL cycles is comparable
in the triple and quadruple populations even though field quadruples are a
factor of ~5 less frequent than triples. Additionally, quadruples might be a
non-negligible source of triples and provide fundamentally new evolutionary
outcomes involving close binaries, mergers, collisions, and associated
transients, which occur without any fine tuning of parameters. Finally, we
study the perturbations to a planetary orbit due to a distant binary and we
find that the fraction of orbital flips is a factor of 3 to 4 higher than for
the corresponding triple system given our fiducial parameters with implications
for hot Jupiters and star-planet collisions.


title: R-matrix analysis of reactions in the 9B compound system

abstract:
  Recent activity in solving the 'lithium problem' in big bang nucleosynthesis
has focused on the role that putative resonances may play in resonance-enhanced
destruction of 7Li. Particular attention has been paid to the reactions
involving the 9B compound nuclear system, d+7Be->9B. These reactions are
analyzed via the multichannel, two-body unitary R-matrix method using code
(EDA) developed by Hale and collaborators. We employ much of the known elastic
and reaction data, in a four-channel treatment. The data include elastic
3He+6Li differential cross sections from 0.7 to 2.0 MeV, integrated reaction
cross sections for energies from 0.7 to 5.0 MeV for 6Li(3He,p)8Be* and from 0.4
to 5.0 MeV for the 6Li(3He,d)7Be reaction. Capture data have been added to an
earlier analysis with integrated cross section measurements from 0.7 to 0.825
MeV for 6Li(3He,gamma)9B. The resulting resonance parameters are compared with
tabulated values, and previously unidentified resonances are noted. Our results
show that there are no near d+7Be threshold resonances with widths that are
10's of keV and reduce the likelihood that a resonance-enhanced mass-7
destruction mechanism, as suggested in recently published work, can explain the
7Li problem.


title:
An infinite cardinal version of Gallai's Theorem for colorings of the
  plane

abstract:
  We generalize a result of Tibor Gallai as follows: for any finite set of
points $\mathcal{S}$ in the plane, if the plane is colored in finitely many
colors, then there exist $2^{\aleph_0}$ monochromatic subsets of the plane
homothetic to $\mathcal{S}$. Furthermore, we prove an even stronger result for
$n$-dimensional Euclidean space.


title: The Superluminal Tunneling Story

abstract:
  Since 1992 experimental evidence of superluminal (faster than light, FTL)
signals are causing much excitement in the physical community and in the media.
Superluminal signal velocity and zero time tunneling was first observed in an
analog tunneling experiment with microwaves. Recently, the conjectured zero
time of electron was claimed to be observed in ionizing helium. The FTL signal
velocity was reproduced with infrared light and with various tunneling barriers
in several laboratories worldwide. Remarkable, it was shown that the tunneling
time is a universal quantity for elastic and for electromagnetic fields. Many
theoretical physicists predicted this FTL nature of the tunneling process.
However, even with this background many members of the physics community did
not accept the superluminal signal velocity interpretation of the experimental
results and they also ignored the universal tunneling time. The predicted and
measured zero tunneling time was taken as a fantastic nonsense. A brief
explanation of the misleading theoretical approaches against FTL signals due to
the tunneling process is presented eventually.


title: Data Secrecy in Distributed Storage Systems under Exact Repair

abstract:
  The problem of securing data against eavesdropping in distributed storage
systems is studied. The focus is on systems that use linear codes and implement
exact repair to recover from node failures.The maximum file size that can be
stored securely is determined for systems in which all the available nodes help
in repair (i.e., repair degree $d=n-1$, where $n$ is the total number of nodes)
and for any number of compromised nodes. Similar results in the literature are
restricted to the case of at most two compromised nodes. Moreover, new explicit
upper bounds are given on the maximum secure file size for systems with
$d<n-1$. The key ingredients for the contribution of this paper are new results
on subspace intersection for the data downloaded during repair. The new bounds
imply the interesting fact that the maximum data that can be stored securely
decreases exponentially with the number of compromised nodes.


title:
Analysis of Citizens Acceptance for E-government Services: Applying the
  UTAUT Model

abstract:
  E-government services aims to provide citizens with more accessible,
accurate, real-time and high quality services and information. Although the
public sectors in Kingdom of Saudi Arabia (KSA) have promoted their
e-Government services for many years, its uses and achievements are few.
Therefore, this paper explores the key factors of Saudi citizens acceptance
through a research survey and by gathering empirical evidence based on the
Unified Theory of Acceptance and the Use of Technology (UTAUT). Survey Data
collected from 400 respondents was examined using structural equation modelling
(SEM) technique and utilized AMOS tools. The study results explored the factors
that affect the acceptance of e-government services in KSA based on UTAUT
model. Moreover, as a result of this study an amended UTAUT model was proposed.
Such a model contributes to the discussion and development of adoption models
for technology.


title: Quotients of Gaussian primes

abstract:
  It has been observed many times, both in the Monthly and elsewhere, that the
set of all quotients of prime numbers is dense in the positive real numbers. In
this short note we answer the related question: "Is the set of all quotients of
Gaussian primes dense in the complex plane?"


title:
Efficient Solution of Backward Jump-Diffusion PIDEs with Splitting and
  Matrix Exponentials

abstract:
  We propose a new, unified approach to solving jump-diffusion partial
integro-differential equations (PIDEs) that often appear in mathematical
finance. Our method consists of the following steps. First, a second-order
operator splitting on financial processes (diffusion and jumps) is applied to
these PIDEs. To solve the diffusion equation, we use standard finite-difference
methods, which for multi-dimensional problems could also include splitting on
various dimensions. For the jump part, we transform the jump integral into a
pseudo-differential operator. Then for various jump models we show how to
construct an appropriate first and second order approximation on a grid which
supersets the grid that we used for the diffusion part. These approximations
make the scheme to be unconditionally stable in time and preserve positivity of
the solution which is computed either via a matrix exponential, or via P{\'a}de
approximation of the matrix exponent. Various numerical experiments are
provided to justify these results.


title:
The influence of relatives on the efficiency and error rate of familial
  searching

abstract:
  We investigate the consequences of adopting the criteria used by the state of
California, as described by Myers et al. (2011), for conducting familial
searches. We carried out a simulation study of randomly generated profiles of
related and unrelated individuals with 13-locus CODIS genotypes and YFiler
Y-chromosome haplotypes, on which the Myers protocol for relative
identification was carried out. For Y-chromosome sharing first degree
relatives, the Myers protocol has a high probability (80 - 99%) of identifying
their relationship. For unrelated individuals, there is a low probability that
an unrelated person in the database will be identified as a first-degree
relative. For more distant Y-haplotype sharing relatives (half-siblings, first
cousins, half-first cousins or second cousins) there is a substantial
probability that the more distant relative will be incorrectly identified as a
first-degree relative. For example, there is a 3 - 18% probability that a first
cousin will be identified as a full sibling, with the probability depending on
the population background. Although the California familial search policy is
likely to identify a first degree relative if his profile is in the database,
and it poses little risk of falsely identifying an unrelated individual in a
database as a first-degree relative, there is a substantial risk of falsely
identifying a more distant Y-haplotype sharing relative in the database as a
first-degree relative, with the consequence that their immediate family may
become the target for further investigation. This risk falls disproportionately
on those ethnic groups that are currently overrepresented in state and federal
databases.


title:
Large enhancement of transport critical current density of ex-situ PIT
  Ag/(Ba,K)Fe2As2 tapes achieved by applying cycles of cold deformation and
  heat treatment

abstract:
  We report that high transport critical current density exceeding 104 A/cm2 at
4.2 K and 10 T can be obtained with good reproducibility for Ag sheathed
(Ba,K)Fe2As2 (Ba 122) tapes by modifying the ex-situ powder-in-tube (PIT)
method. The process involves cycles of the cold deformation and subsequent heat
treatment. The intermediate cycles of flat rolling and heat treatment produce
uniform fine-grained structure, resulting in an enhancement of transport Jc in
applied magnetic fields. However, the rolled tapes contain cracks running
traverse to the tape axis, which still limit the current pass along the tape
axis. We found that the application of uniaxial pressing with small reduction
rate at the final stage is very effective to heal those cracks, resulting in an
extraordinary increase of the transport Jc. We achieved the highest Jc (at 4.2
K and 10 T) of 2.1x104 A/cm2 among the PIT processed Fe based wires and tapes
reported so far. The Jc-H curves measured at higher temperatures maintains a
small filed dependence up to around 20 K, suggesting that the tapes are
promising for applications at higher temperatures as well as in liquid helium.


title:
Principal Component Analysis and Higher Correlations for Distributed
  Data

abstract:
  We consider algorithmic problems in the setting in which the input data has
been partitioned arbitrarily on many servers. The goal is to compute a function
of all the data, and the bottleneck is the communication used by the algorithm.
We present algorithms for two illustrative problems on massive data sets: (1)
computing a low-rank approximation of a matrix $A=A^1 + A^2 + \ldots + A^s$,
with matrix $A^t$ stored on server $t$ and (2) computing a function of a vector
$a_1 + a_2 + \ldots + a_s$, where server $t$ has the vector $a_t$; this
includes the well-studied special case of computing frequency moments and
separable functions, as well as higher-order correlations such as the number of
subgraphs of a specified type occurring in a graph. For both problems we give
algorithms with nearly optimal communication, and in particular the only
dependence on $n$, the size of the data, is in the number of bits needed to
represent indices and words ($O(\log n)$).


title: On piecewise smooth cohomology of locally trivial Lie groupoids

abstract:
  Mishchenko-Oliveira proved the piecewise smooth cohomology and Lie algebroid
cohomology of a Lie algebroid on a combinatorial compact manifold are
isomorphic. In this paper, we describe an application of that result locally
trivial Lie groupoids on combinatorial manifolds to obtain an isomorphism
between de Rham cohomology and piecewise de Rham cohomology of left invariants
forms.


title:
Effect of anisotropic Fermi surface on the flux-flow resistivity under
  rotating magnetic field

abstract:
  We numerically investigate the effect of in-plane anisotropic Fermi surface
(FS) on the flux-flow resistivity $\rho_{\rm f}$ under rotating magnetic field
on the basis of the quasiclassical Green's function method. We demonstrate that
one can detect the phase in pairing potential of Cooper pair through the
field-angular dependence of $\rho_{\rm f}$ even if the FS has in-plane
anisotropy. In addition, we point out one can detect the gap-node directions
irrespective of the FS anisotropy by measuring $\rho_{\rm f}$ under rotating
field.


title:
Photometric variability in a warm, strongly magnetic DQ white dwarf,
  SDSS J103655.39+652252.2

abstract:
  We present the discovery of photometric variability in the DQ white dwarf
SDSS J103655.39+652252.2 (SDSS J1036+6522). Time-series photometry reveals a
coherent monoperiodic modulation at a period of 1115.64751(67) s with an
amplitude of 0.442% +/- 0.024%; no other periodic modulations are observed with
amplitudes >~0.13%. The period, amplitude, and phase of this modulation are
constant within errors over 16 months. The spectrum of SDSS J1036+6522 shows
magnetic splitting of carbon lines, and we use Paschen-Back formalism to
develop a grid of model atmospheres for mixed carbon and helium atmospheres.
Our models, while reliant on several simplistic assumptions, nevertheless match
the major spectral and photometric properties of the star with a
self-consistent set of parameters: Teff~15,500 K, log g ~9, log(C/He)=-1.0, and
a mean magnetic field strength of 3.0 +/- 0.2 MG. The temperature and
abundances strongly suggest that SDSS J1036+6522 is a transition object between
the hot, carbon-dominated DQs and the cool, He-dominated DQs. The variability
of SDSS J1036+6522 has characteristics similar to those of the variable hot
carbon-atmosphere white dwarfs (DQVs), however, its temperature is
significantly cooler. The pulse profile of SDSS J1036+6522 is nearly
sinusoidal, in contrast with the significantly asymmetric pulse shapes of the
known magnetic DQVs. If the variability in SDSS J1036+6522 is due to the same
mechanism as other DQVs, then the pulse shape is not a definitive diagnostic on
the absence of a strong magnetic field in DQVs. It remains unclear whether the
root cause of the variability in SDSS J1036+6522 and the other hot DQVs is the
same.


title: Quantum Storage and Retrieval of Light by Sweeping the Atomic Frequency

abstract:
  We propose a quantum memory protocol based on dynamically changing the
resonance frequency of an ensemble of two-level atoms. By sweeping the atomic
frequency in an adiabatic fashion, photons are reversibly transferred into
atomic coherences. We present a polaritonic description for this type of
storage, which shares some similarities with Electromagnetically Induced
Transparency (EIT) based quantum memories. On the other hand the proposed
memory is also linked to the Gradient Echo Memory (GEM) due to the effective
spatial gradient that pulses experience in the medium. We discuss a possible
implementation of the protocol in hollow-core photonic crystal fibers.


title:
Dynamics of the solar tachocline III: Numerical solutions of the Gough
  and McIntyre model

abstract:
  We present the first numerical simulations of the solar interior to exhibit a
tachocline consistent with the Gough and McIntyre (1998) model. We find
nonlinear, axisymmetric, steady-state numerical solutions in which: (1) a
large-scale primordial field is confined within the radiation zone by
downwelling meridional flows that are gyroscopically pumped in the convection
zone (2) the radiation zone is in almost-uniform rotation, with a rotation rate
consistent with observations (3) the bulk of the tachocline is magnetic free,
in thermal-wind balance and in thermal equilibrium and (4) the interaction
between the field and the flows takes place within a very thin magnetic
boundary layer, the tachopause, located at the bottom of the tachocline. We
show that the thickness of the tachocline scales with the amplitude of the
meridional flows exactly as predicted by Gough and McIntyre. We also determine
the parameter conditions under which such solutions can be obtained, and
provide a simple explanation for the failure of previous numerical attempts at
reproducing the Gough and McIntyre model. Finally, we discuss the implications
of our findings for future numerical models of the solar interior, and for
future observations of the Sun and other stars.


title:
Powering of cool filaments in cluster cores by buoyant bubbles. I.
  Qualitative model

abstract:
  Cool-core clusters (e.g., Perseus or M87) often possess a network of bright
gaseous filaments, observed in radio, infrared, optical and X-ray bands. We
propose that these filaments are powered by the reconnection of the magnetic
field in the wakes of buoyant bubbles. AGN-inflated bubbles of relativistic
plasma rise buoyantly in the cluster atmosphere, stretching and amplifying the
field in the wake to values of $\displaystyle \beta =8\pi P_{gas}/B^2\sim 1$.
The field lines in the wake have opposite directions and are forced together as
the bubble motion stretches the filament. This setup bears strong similarity to
the coronal loops on the Sun or to the Earth's magneto-tail. The reconnection
process naturally explains both the required level of local dissipation rate in
filaments and the overall luminosity of filaments. The original source of power
for the filaments is the potential energy of buoyant bubbles, inflated by the
central AGN.


title: The Computational Complexity of Random Serial Dictatorship

abstract:
  In social choice settings with linear preferences, random dictatorship is
known to be the only social decision scheme satisfying strategyproofness and ex
post efficiency. When also allowing indifferences, random serial dictatorship
(RSD) is a well-known generalization of random dictatorship that retains both
properties. RSD has been particularly successful in the special domain of
random assignment where indifferences are unavoidable. While executing RSD is
obviously feasible, we show that computing the resulting probabilities is
#P-complete and thus intractable, both in the context of voting and assignment.


title:
The generalized Kupershmidt deformation for constructing new discrete
  integrable systems

abstract:
  KdV6 equation can be described as the Kupershmidt deformation of the KdV
equation (see 2008, Phys. Lett. A 372: 263). In this paper, starting from the
bi-Hamiltonian structure of the discrete integrable system, we propose a
generalized Kupershmidt deformation to construct new discrete integrable
systems. Toda hierarchy, Kac-van Moerbeke hierarchy and Ablowitz-Ladik
hierarchy are considered. The Lax representations for these new deformed
systems are presented. The generalized Kupershmidt deformation for the discrete
integrable systems provides a new way to construct new discrete integrable
systems.


title: Exploring the Interstellar Media of Optically Compact Dwarf Galaxies

abstract:
  We present new Very Large Array HI spectral line, archival Sloan Digital Sky
Survey, and archival Spitzer Space Telescope imaging of eight star-forming blue
compact dwarf galaxies that were selected to be optically compact (optical
radii less than 1 kpc). These systems have faint blue absolute magnitudes (M_B
>= -17), ongoing star formation (based on emission-line selection by the H
alpha or [OIII] lines), and are nearby (mean velocity = 3315 km/s = 45 Mpc).
One galaxy in the sample, ADBS 113845+2008, is found to have an HI halo that
extends 58 r-band scale lengths from its stellar body. In contrast, the rest of
the sample galaxies have HI radii to optical-scale-length ratios ranging from
9.3 to 26. The size of the HI disk in the "giant disk" dwarf galaxy ADBS
113845+2008 appears to be unusual as compared to similarly compact stellar
populations.


title: Buffer Management of Multi-Queue QoS Switches with Class Segregation

abstract:
  In this paper, we focus on buffer management of multi-queue QoS switches in
which packets of different values are segregated in different queues. Our model
consists of $m$ queues and $m$ packet values $0 < v_{1} < v_{2} < ... < v_{m}$.
Recently, Al-Bawani and Souza [IPL 113(4), pp.145-150, 2013] presented an
online algorithm GREEDY for buffer management of multi-queue QoS switches with
class segregation and showed thatif $m$ queues have the same size, then the
competitive ratio of GREEDY is $1+r$, where $r=\max_{1 \leq i \leq m-1}
v_{i}/v_{i+1}$. In this paper, we precisely analyze the behavior of GREEDY and
show that it is $(1+r)$-competitive for the case that $m$ queues do not
necessarily have the same size.


title:
Influence of secondary gas on control characteristics of ICP-RF plasma
  torches

abstract:
  Thermal plasma characteristics inside an atmospheric pressure Radio-Frequency
Argon plasma torch have been studied by numerically solving axis-symmetric 2-D
Magnetohydrodynamics equations, energy transport equations and species
conservation equation coupled with 2D Maxwell equations in the vector potential
form. A renormalization group k - epsilon model was employed to study the
turbulence within the torch. Helium is mixed with Argon for injection as the
sheath gas, and its effect on the control characteristics of the torch has been
studied. A control volume approach and semi-implicit pressure linked equations
revised (SIMPLER) algorithm was used to solve the above set of equations to
obtain the flow, temperature, turbulence and EM source fields within the torch.
Finally, a comparison of the results obtained in our present calculation has
been made with other works of similar nature. The torch geometry, flow rates
and power dissipation values used in the present calculation are similar to the
standard ones available in literature.


title:
The LAMOST Survey of Background Quasars in the Vicinity of the Andromeda
  and Triangulum Galaxies -- II. Results from the Commissioning Observations
  and the Pilot Surveys

abstract:
  We present new quasars discovered in the vicinity of the Andromeda and
Triangulum galaxies with the LAMOST during the 2010 and 2011 observational
seasons. Quasar candidates are selected based on the available SDSS, KPNO 4 m
telescope, XSTPS optical, and WISE near infrared photometric data. We present
509 new quasars discovered in a stripe of ~135 sq. deg from M31 to M33 along
the Giant Stellar Stream in the 2011 pilot survey datasets, and also 17 new
quasars discovered in an area of ~100 sq. deg that covers the central region
and the southeastern halo of M31 in the 2010 commissioning datasets. These 526
new quasars have i magnitudes ranging from 15.5 to 20.0, redshifts from 0.1 to
3.2. They represent a significant increase of the number of identified quasars
in the vicinity of M31 and M33. There are now 26, 62 and 139 known quasars in
this region of the sky with i magnitudes brighter than 17.0, 17.5 and 18.0
respectively, of which 5, 20 and 75 are newly-discovered. These bright quasars
provide an invaluable collection with which to probe the kinematics and
chemistry of the ISM/IGM in the Local Group of galaxies. A total of 93 quasars
are now known with locations within 2.5 deg of M31, of which 73 are newly
discovered. Tens of quasars are now known to be located behind the Giant
Stellar Stream, and hundreds behind the extended halo and its associated
substructures of M31. The much enlarged sample of known quasars in the vicinity
of M31 and M33 can potentially be utilized to construct a perfect astrometric
reference frame to measure the minute PMs of M31 and M33, along with the PMs of
substructures associated with the Local Group of galaxies. Those PMs are some
of the most fundamental properties of the Local Group.


title: Microscopic optical potential from chiral nuclear forces

abstract:
  The energy- and density-dependent single-particle potential for nucleons is
constructed in a medium of infinite isospin-symmetric nuclear matter starting
from realistic nuclear interactions derived within the framework of chiral
effective field theory. The leading-order terms from both two- and
three-nucleon forces give rise to real, energy-independent contributions to the
nucleon self-energy. The Hartree-Fock contribution from the two-nucleon force
is attractive and strongly momentum dependent, in contrast to the contribution
from the three-nucleon force which provides a nearly constant repulsive mean
field that grows approximately linearly with the nuclear density. Together, the
leading-order perturbative contributions yield an attractive single-particle
potential that is however too weak compared to phenomenology. Second-order
contributions from two- and three-body forces then provide the additional
attraction required to reach the phenomenological depth. The imaginary part of
the optical potential, which is positive (negative) for momenta below (above)
the Fermi momentum, arises at second-order and is nearly inversion-symmetric
about the Fermi surface when two-nucleon interactions alone are present. The
imaginary part is strongly absorptive and requires the inclusion of an
effective mass correction as well as self-consistent single-particle energies
to attain qualitative agreement with phenomenology.


title:
Comparing gravitational waves from nonprecessing and precessing black
  hole binaries in the corotating frame

abstract:
  Previous analytic and numerical calculations suggest that, at each instant,
the emission from a precessing black hole binary closely resembles the emission
from a nonprecessing analog. In this paper we quantitatively explore the
validity and limitations of that correspondence, extracting the radiation from
a large collection of roughly two hundred generic black hole binary merger
simulations both in the simulation frame and in a corotating frame that tracks
precession. To a first approximation, the corotating-frame waveforms resemble
nonprecessing analogs, based on similarity over a band-limited frequency
interval defined using a fiducial detector (here, advanced LIGO) and the
source's total mass $M$. By restricting attention to masses $M\in 100, 1000
M_\odot$, we insure our comparisons are sensitive only to our simulated
late-time inspiral, merger, and ringdown signals. In this mass region, every
one of our precessing simulations can be fit by some physically similar member
of the \texttt{IMRPhenomB} phenomenological waveform family to better than 95%;
most fit significantly better. The best-fit parameters at low and high mass
correspond to natural physical limits: the pre-merger orbit and post-merger
perturbed black hole. Our results suggest that physically-motivated synthetic
signals can be derived by viewing radiation from suitable nonprecessing
binaries in a suitable nonintertial reference frame. While a good first
approximation, precessing systems have degrees of freedom (i.e., the transverse
spins) which a nonprecessing simulation cannot reproduce. We quantify the
extent to which these missing degrees of freedom limit the utility of synthetic
precessing signals for detection and parameter estimation.


title:
On the Relation between Context-Free Grammars and Parsing Expression
  Grammars

abstract:
  Context-Free Grammars (CFGs) and Parsing Expression Grammars (PEGs) have
several similarities and a few differences in both their syntax and semantics,
but they are usually presented through formalisms that hinder a proper
comparison. In this paper we present a new formalism for CFGs that highlights
the similarities and differences between them. The new formalism borrows from
PEGs the use of parsing expressions and the recognition-based semantics. We
show how one way of removing non-determinism from this formalism yields a
formalism with the semantics of PEGs. We also prove, based on these new
formalisms, how LL(1) grammars define the same language whether interpreted as
CFGs or as PEGs, and also show how strong-LL(k), right-linear, and LL-regular
grammars have simple language-preserving translations from CFGs to PEGs.


title: XYZ quantum Heisenberg models with p-orbital bosons

abstract:
  We demonstrate how the spin-1/2 XYZ quantum Heisenberg model can be realized
with bosonic atoms loaded in the p band of an optical lattice in the Mott
regime. The combination of Bose statistics and the symmetry of the p-orbital
wave functions leads to a nonintegrable Heisenberg model with antiferromagnetic
couplings. Moreover, the sign and relative strength of the couplings
characterizing the model are shown to be experimentally tunable. We display the
rich phase diagram in the one-dimensional case and discuss finite size effects
relevant for trapped systems. Finally, experimental issues related to
preparation, manipulation, detection, and imperfections are considered.


title:
Joint Precoding and Multivariate Backhaul Compression for the Downlink
  of Cloud Radio Access Networks

abstract:
  This work studies the joint design of precoding and backhaul compression
strategies for the downlink of cloud radio access networks. In these systems, a
central encoder is connected to multiple multi-antenna base stations (BSs) via
finite-capacity backhaul links. At the central encoder, precoding is followed
by compression in order to produce the rate-limited bit streams delivered to
each BS over the corresponding backhaul link. In current state-of-the-art
approaches, the signals intended for different BSs are compressed
independently. In contrast, this work proposes to leverage joint compression,
also referred to as multivariate compression, of the signals of different BSs
in order to better control the effect of the additive quantization noises at
the mobile stations (MSs). The problem of maximizing the weighted sum-rate with
respect to both the precoding matrix and the joint correlation matrix of the
quantization noises is formulated subject to power and backhaul capacity
constraints. An iterative algorithm is proposed that achieves a stationary
point of the problem. Moreover, in order to enable the practical implementation
of multivariate compression across BSs, a novel architecture is proposed based
on successive steps of minimum mean-squared error (MMSE) estimation and per-BS
compression. Robust design with respect to imperfect channel state information
is also discussed. From numerical results, it is confirmed that the proposed
joint precoding and compression strategy outperforms conventional approaches
based on the separate design of precoding and compression or independent
compression across the BSs.


title:
Unification and refinements of Jordan, Adamovi\'c-Mitrinovi\'cand and
  Cusa's inequalities

abstract:
  In this paper, we find some new sharp bounds for $\left(\sin x\right) /x$,
which unify and refine Jordan, Adamovi\'{c}-Mitrinovi\'{c}and and Cusa's
inequalities. As applications of main results, some new Shafer-Fink type
inequalities for arc sine function and ones for certain bivariate means are
established, and a simpler but more accurate estimate for sine integral is
derived.


title:
Noether current from surface term, Virasoro algebra and black hole
  entropy in bigravity

abstract:
  We consider the static, spherically symmetric black hole solutions in
bigravity theory for minimal model with a condition $f_{\mu \nu} = C^{2} g_{\mu
\nu}$ and evaluate the entropy for black holes. In this condition, we show that
there exists the Schwarzschild solution for $C^{2} = 1$, which is unique
consistent solution. We examine how the massive spin-2 field contributes and
affects to the Bekenstein-Hawking entropy corresponding to Einstein gravity. In
order to obtain the black hole entropy, we use a recently proposed approach
which use Virasoro algebra and central charge corresponding to surface term in
the gravitational action.


title: Natural NMSSM confronting with the LHC7-8

abstract:
  The natural supersymmetry (SUSY) requires that stop, sbottom, and gluino be
around one TeV or lighter. By using the direct SUSY search bounds from both
ATLAS and CMS Collaborations, we examine the constraints on the natural SUSY in
the Next to Minimal Supersymmetric Standard Model (NMSSM). We consider two
cases of interpretations for the Higgs boson data: (1) the Standard Model (SM)
like Higgs boson is the lightest CP-even Higgs boson; (2) the SM like Higgs
boson is the second lightest CP-even Higgs boson. We find that the direct SUSY
searches at the LHC impose a strong constraint on the light gluino scenarios,
and in both cases the gluino can not be lighter than 1.1 TeV with sbottom mass
up to 600 GeV and stop mass up to 550 GeV.


title:
Characterization of Downlink Transmit Power Control during Soft Handover
  in WCDMA Systems

abstract:
  This paper presents the characterization of power control in WCDMA systems.
We know that CDMA is an interference limited system. It is shown that the
unbalance scheme is reliable and successful for both 2-way and 3-way soft
handover. Unbalance scheme minimizes interference and speed up the soft
handover algorithm to support more users quickly. Furthermore it requires
minimum time to make decision for proper power control in soft handover status.


title: New minimal surfaces in S^3 desingularizing the Clifford tori

abstract:
  For each integer m>1 and l>0 we construct a pair of compact embedded minimal
surfaces of genus 1+4m(m-1)l. These surfaces desingularize the m Clifford tori
meeting each other along a great circle at the angle of \pi/m. They are
invariant under a finite group of screw motions and have no reflection symmetry
across a great sphere.


title:
Optical and mid-infrared neon abundance determinations in star-forming
  regions

abstract:
  We employed observational spectroscopic data of star-forming regions compiled
from the literature and photoionization models to analyse the neon ionic
abundances obtained using both optical and mid-infrared emission-lines.
Comparing Ne++/H+ ionic abundances from distinct methods, we found that, in
average, the abundances obtained via IR emission-lines are higher than those
obtained via optical lines by a factor of 4. Photoionization models with
abundance variations along the radius of the hypothetical nebula provide a
possible explanation for a large part of the difference between ionic
abundances via optical and infrared emission-lines. Ionization Correction
Factor (ICF) for the neon is obtained from direct determinations of ionic
fractions using infrared emission-lines. A constant Ne/O ratio (logNe/O \approx
-0.70) for a large range of metallicity, independently of the ICF used to
compute the neon total abundance is derived.


title:
Implications of the kinematical structure of circumnuclear star-forming
  regions on their derived properties

abstract:
  [Abbreviated] We review the results of high dispersion spectroscopy of 17
circumnuclear starforming regions (CNSFRs) in 3 nearby early spiral galaxies,
NGC2903, NGC3310 and NGC3351. We find that single Gaussian fitting to the
H$\beta$ and [OIII]5007A line profiles results in velocity dispersions around
32km/s and 52km/s, respectively, while the IR CaII triplet cross-correlation
technique provides stellar velocity dispersion values close to 50km/s. Even
though multiple kinematical components are present, the relation between gas
velocity dispersion and Balmer emission line luminosity (L-sigma relation)
reproduces the correlation for disk giant HII regions albeit with a larger
scatter. The scatter in the L-sigma relation is considerably reduced when
theoretical evolutionary corrections are applied suggesting that an age range
is present in the sample of CNSFRs. To analyse the observed complex profiles,
we performed multiple Gaussian component fits to the Hbeta and [OIII]?5007A
lines obtaining optimal fits with two Gaussians of different width. These best
fits indicate that the narrower component has average velocity dispersion close
to 23km/s while the broader component shows average values in the range
50-60km/s for both lines, close to the observed stellar velocity dispersions.
The fluxes of the broad and narrow Hbeta components are similar. This is not
the case for [OIII]5007A for which the broad components have higher fluxes than
the narrow ones, thus producing a clear segregation in their [OIII]/Hbeta
ratios. We suggest a possible scenario for understanding the behaviour of
CNSFRs in the L-sigma and sigma_gas-sigma_star diagrams involving an inner
gaseous disk responsible for the narrow component of the emission lines.


title: Ordered Partitions Avoiding a Permutation of Length 3

abstract:
  An ordered partition of $[n]=\{1, 2, \ldots, n\}$ is a partition whose blocks
are endowed with a linear order. Let $\mathcal{OP}_{n,k}$ be set of ordered
partitions of $[n]$ with $k$ blocks and $\mathcal{OP}_{n,k}(\sigma)$ be set of
ordered partitions in $\mathcal{OP}_{n,k}$ that avoid a pattern $\sigma$.
Recently, Godbole, Goyt, Herdan and Pudwell obtained formulas for the number of
ordered partitions of $[n]$ with 3 blocks and the number of ordered partitions
of $[n]$ with $n-1$ blocks avoiding a permutation pattern of length 3. They
showed that $|\mathcal{OP}_{n,k}(\sigma)|=|\mathcal{OP}_{n,k}(123)|$ for any
permutation $\sigma$ of length 3, and raised the question concerning the
enumeration of $\mathcal{OP}_{n,k}(123)$. They also conjectured that the number
of ordered partitions of $[2n]$ with blocks of size 2 avoiding a permutation
pattern of length 3 satisfied a second order linear recurrence relation. In
answer to the question of Godbole, et al., we obtain the generating function
for $|\mathcal{OP}_{n,k}(123)|$ and we prove the conjecture on the recurrence
relation.


title: Developing AMS measurement of $^{59}$Ni at CIAE

abstract:
  Accelerator mass spectrometry (AMS) measurement of $^{59}$Ni has been
established at CIAE with the HI-13 tandem accelerator and the recently
developed $\Delta E$-Q3D detection system. $^{59}$Ni standard and commercial
NiO samples were measured to check the performance of the $\Delta E$-Q3D
detection system on $^{59}$Ni isobar separation and suppression. An overall
suppression factor of about 10$^{7}$ for the interfering isobar $^{59}$Co
resulting in detection sensitivity as low as 3.8$\times 10^{-13}$ atomic ratio
($^{59}$Ni/Ni) has been obtained. Based on these techniques, the AMS
measurement method of $^{59}$Ni with high sensitivity is developed.


title: Multifractality can be a universal signature of phase transitions

abstract:
  Macroscopic systems often display phase transitions where certain physical
quantities are singular or self-similar at different (spatial) scales. Such
properties of systems are currently characterized by some order parameters and
a few critical exponents. Nevertheless, recent studies show that the
multifractality, where a large number of exponents are needed to quantify
systems, appears in many complex systems displaying self-similarity. Here we
propose a general approach and show that the appearance of the multifractality
of an order parameter related quantity is the signature of a physical system
transiting from one phase to another. The distribution of this quantity
obtained within suitable (time) scales satisfies a $q$-Gaussian distribution
plus a possible Cauchy distributed background. At the critical point the
$q$-Gaussian shifts between Gaussian type with narrow tails and
L$\acute{\text{e}}$vy type with fat tails. Our results suggest that the Tsallis
$q$-statistics, besides the conventional Boltzmann-Gibbs statistics, may play
an important role during phase transitions.


title: Non-Hermitian Hamiltonians in decoherence and equilibrium theory

abstract:
  There are many formalisms to describe quantum decoherence. However, many of
them give a non general and ad hoc definition of "pointer basis" or "moving
preferred basis", and this fact is a problem for the decoherence program. In
this paper we will consider quantum systems under a general theoretical
framework for decoherence and we will present a tentative definition of the
moving preferred basis. These ideas are implemented in a well-known open system
model. The obtained decoherence and the relaxation times are defined and
compared with those of the literature for the Lee- Friedrichs model.


title: On L\'evy processes conditioned to avoid zero

abstract:
  The purpose of this paper is to construct the law of a L\'evy process
conditioned to avoid zero, under mild technicals conditions, two of them being
that the point zero is regular for itself and the L\'evy process is not a
compound Poisson process. Two constructions are proposed, the first lies on the
method of $h$-transformation, which requires a deep study of the associated
excessive function; while in the second it is obtained by conditioning the
underlying L\'evy process to avoid zero up to an independent exponential time
whose parameter tends to $0.$ The former approach generalizes some of the
results obtained by Yano \cite{Yano10} in the symmetric case and recovers some
of main results in Yano's work \cite{Yano13}, while the latter is reminiscent
of \cite{Chaumont-Doney05}. We give some properties of the resulting process
and we describe in some detail two examples: alpha stable and spectrally
negative L\'evy processes.


title:
Rotational Projection Statistics for 3D Local Surface Description and
  Object Recognition

abstract:
  Recognizing 3D objects in the presence of noise, varying mesh resolution,
occlusion and clutter is a very challenging task. This paper presents a novel
method named Rotational Projection Statistics (RoPS). It has three major
modules: Local Reference Frame (LRF) definition, RoPS feature description and
3D object recognition. We propose a novel technique to define the LRF by
calculating the scatter matrix of all points lying on the local surface. RoPS
feature descriptors are obtained by rotationally projecting the neighboring
points of a feature point onto 2D planes and calculating a set of statistics
(including low-order central moments and entropy) of the distribution of these
projected points. Using the proposed LRF and RoPS descriptor, we present a
hierarchical 3D object recognition algorithm. The performance of the proposed
LRF, RoPS descriptor and object recognition algorithm was rigorously tested on
a number of popular and publicly available datasets. Our proposed techniques
exhibited superior performance compared to existing techniques. We also showed
that our method is robust with respect to noise and varying mesh resolution.
Our RoPS based algorithm achieved recognition rates of 100%, 98.9%, 95.4% and
96.0% respectively when tested on the Bologna, UWA, Queen's and Ca' Foscari
Venezia Datasets.


title: Abstract Weyl-type Theorems

abstract:
  In this paper, we give a new approach for the study of Weyl-type theorems.
Precisely we introduce the concepts of spectral valued and spectral
partitioning functions. Using two natural order relations on the set of
spectral valued functions, we reduce the question of relationship between
Weyl-type theorems to the study of the set difference between the parts of the
spectrum that are involved. This study solves completely the question of
relationship between two spectral valued functions, comparable for one or the
other order relation. Then several known results about Weyl-type theorems
becomes corollaries of the results obtained.


title: Non-Markovianity during quantum Zeno effect

abstract:
  We examine the Zeno and anti-Zeno effects in the context of non-Markovian
dynamics in entangled spin-boson systems in contact with noninteracting
reservoirs. We identify enhanced non-Markovian signatures in specific two-qubit
partitions of a Bell-like initial state, with results showing that the
intra-qubit Zeno effect or anti-Zeno effect occurs in conjunction with
inter-qubit non-Markovian dynamics for a range of system parameters. The time
domain of effective Zeno or anti-Zeno dynamics is about the same order of
magnitude as the non-Markovian time scale of the reservoir correlation
dynamics, and changes in decay rate due to the Zeno mechanism appears
coordinated with information flow between specific two-qubit partitions. We
extend our analysis to examine the Zeno mechanism-non-Markovianity link using
the tripartite states arising from a donor-acceptor-sink model of
photosynthetic biosystems.


title: Rare Decays of K and B Mesons Revisited

abstract:
  The rare decays of mesons are higher order effects in weak interactions. The
main contributions to such decay processes are from the Z-penguin, the
photonpenguin and the box diagram. At the quark level, these contributions are
well known. However, when considering the corresponding physical hadronic
processes, a knowledge of how hadronic states are expressed in terms of quarks.
In this paper, we suggest a simplistic way to relate the quark level process to
the hadronic process. For simplicity, we consider here only the decays of
pseudoscalar mesons. The meson-quark coupling is described in terms of a
gamma-5 coupling with a constant coupling constant. We apply the model to
processes in which meson M1 decays to meson M2 with the emissions of neutrino
pair and charged lepton pair. In calculating the decay rates, a cut-off
momentum lamda is introduced to control the divergent triangle integral over
the internal momentum. The results of our calculation is compared to
experimental data on the decay rates for K- and B-meson decays.


title: Artificial color perception using microwaves

abstract:
  We report the feasibility of artificial color perception under microwave
illumination using a standard microwave source and an antenna. We have sensed
transmitted microwave power through color objects and have distinguished the
colors by analyzing the sensed transmitted power. Experiments are carried out
using a Gunn diode as the microwave source, some colored liquids as the objects
and a microwave diode as the detector. Results are presented which open up an
unusual but new way of perceiving colors using microwaves.


title: Weil-Petersson Teichm\"uller space

abstract:
  The paper presents some recent results on the Weil-Petersson geometry theory
of the universal Teichm\"uller space, a topic which is important in
Teichm\"uller theory and has wide applications to various areas such as
mathematical physics, differential equation and computer vision.
  \noindent (1) It is shown that a sense-preserving homeomorphism $h$ on the
unit circle belongs to the Weil-Petersson class, namely, $h$ can be extended to
a quasiconformal mapping to the unit disk whose Beltrami coefficient is
squarely integrable in the Poincar\'e metric if and only if $h$ is absolutely
continuous such that $\log h'$ belongs to the Sobolev class $H^{\frac 12}$.
This solves an open problem posed by Takhtajan-Teo [TT2] in 2006 and
investigated later by Figalli [Fi], Gay-Balmaz-Marsden-Ratiu ([GMR], [GR]) and
others.
  \noindent The intrinsic characterization (1) of the Weil-Petersson class has
the following applications which are also explored in this paper:
  \noindent (2) It is proved that there exists a quasisymmetric homeomorphism
of the Weil-Petersson class which belongs neither to the Sobolev class
$H^{\frac 32}$ nor to the Lipschitz class $\Lambda^1$, which was conjectured
very recently by Gay-Balmaz-Ratiu [GR] when studying the classical
Euler-Poincar\'e equation in the new setting that the involved sense-preserving
homeomorphisms on the unit circle belong to the Weil-Petersson class.
  \noindent (3) It is proved that the flows of the $H^{\frac 32}$ vector fields
on the unit circle are contained in the Weil-Petersson class, which was also
conjectured by Gay-Balmaz-Ratiu [GR] during their above mentioned research.
  \noindent (4) A new metric is introduced on the Weil-Petersson Teichm\"uller
space and is shown to be topologically equivalent to the Weil-Petersson metric.


title:
Approximate controllability and optimal control of impulsive fractional
  semilinear delay differential equations with non-local conditions

abstract:
  In this paper we study the approximate controllability and existence of
optimal control of impulsive fractional semilinear delay differential equations
with non-local conditions. We use Sadovskii's fixed point theorem, semigroup
theory of linear operators and direct method for minimizing a functional to
establish our results. At the end we give an example to illustrate our
analytical findings.


title: On the exponent of distribution of the ternary divisor function

abstract:
  We show that the exponent of distribution of the ternary divisor function
$d_3$ in arithmetic progressions to prime moduli is at least 1/2+1/46,
improving results of Heath-Brown and Friedlander--Iwaniec. Furthermore, when
averaging over a fixed residue class, we prove that this exponent is increased
to 1/2 +1/34.


title:
An Approach to Solve Linear Equations Using a Time-Variant Adaptation
  Based Hybrid Evolutionary Algorithm

abstract:
  For small number of equations, systems of linear (and sometimes nonlinear)
equations can be solved by simple classical techniques. However, for large
number of systems of linear (or nonlinear) equations, solutions using classical
method become arduous. On the other hand evolutionary algorithms have mostly
been used to solve various optimization and learning problems. Recently,
hybridization of evolutionary algorithm with classical Gauss-Seidel based
Successive Over Relaxation (SOR) method has successfully been used to solve
large number of linear equations; where a uniform adaptation (UA) technique of
relaxation factor is used. In this paper, a new hybrid algorithm is proposed in
which a time-variant adaptation (TVA) technique of relaxation factor is used
instead of uniform adaptation technique to solve large number of linear
equations. The convergence theorems of the proposed algorithms are proved
theoretically. And the performance of the proposed TVA-based algorithm is
compared with the UA-based hybrid algorithm in the experimental domain. The
proposed algorithm outperforms the hybrid one in terms of efficiency.


title:
CR-structures of codimension 2 on tangent bundles in Riemann-Finsler
  geometry

abstract:
  We determine a 2-codimensional CR-structure on the slit tangent bundle $T_0M$
of a Finsler manifold $(M, F)$ by imposing a condition regarding the almost
complex structure $\Psi$ associated to $F$ when restricted to the structural
distribution of a framed $f$-structure. This condition is satisfied when $(M,
F)$ is of scalar flag curvature (particularly flat) and in the Riemannian case
$(M, g)$ this last condition means that $g$ is of constant curvature. This
CR-structure is finally generalized by using one positive number but under more
difficult conditions.


title: Ergodicity of laminations with singularities in K\"ahler surfaces

abstract:
  If $\mathcal{L}$ is a laminations with hyperbolic singularities, embedded in
a compact homogeneous K\"ahler surface, without directed closed positive
currents. Then, $\mathcal{L}$ has a unique directed positive harmonic current
of mass one. This result was previously obtained by Fornaess and Sibony for
$\mathbb{CP}^2$ and we generalize it for the rest of compact homogeneous
K\"ahler surfaces.


title: Cloud Computing Research Challenges

abstract:
  In recent times cloud computing has appeared as a new model for hosting and
conveying services over the Internet. This model is striking to business
vendors as it eradicates the requirement for users to plan in advance, and it
permits the organization to start from low level and then add more resources
only if there is an increase in the service demand. Even though cloud computing
presents greater opportunities not only to information technology industry, but
every organization involved in utilizing the computing in one way or the other,
it is still in infancy with many problems to be fixed. The paper discusses
research challenges in cloud computing.


title:
Field induced phase transitions and phase diagrams in BiFeO_3-like
  multiferroics

abstract:
  The incommensurate magnetic structures and phase diagrams of multiferroics
has been explored on the basis of accurate micromagnetic analysis taking into
account the spin flexoelecric interaction (Lifshitz invariant). The objects of
the study are BiFeO_3-like single crystals and epitaxial films grown on the
<111> substrates. The main control parameters are the magnetic field, the
magnetic anisotropy, and the epitaxial strain in the case of films. We predict
novel quasi-cycloidal structures induced by external magnetic field or by
epitaxial strain in the BiFeO_3-films. Phase diagrams representing the regions
of homogeneous magnetic states and incommensurate structures stability are
constructed for the two essential geometries of magnetic field (magnetic field
oriented parallel to the principal crystal axis C_3 and perpendicular to this
direction C_3). It is shown that the direction of applied magnetic field
substantially affects a set of magnetic phases, properties of incommensurate
structures, character of phase transitions. Novel conical type of cycloidal
ordering is revealed during the transition from incommensurate cycloidal
structure into homogeneous magnetic state. Elaborated phase diagrams allow
estimate appropriate combination of control parameters (magnetic field,
magnetic anisotropy, exchange stiffness) required to the destruction of
cycloidal ordering corresponding to the transition into homogeneous structure.
The results show that the magnitude of critical magnetic field suppressing
cycloid is lowered in multiferroics films comparing to single crystals, it can
be also lowered by the selection of orientation of magnetic field. Our results
can be useful for strain engineering of new multiferroic functional materials
on demand.


title:
Search for the Lepton Flavor Violation Process $J/\psi \to e\mu$ at
  BESIII

abstract:
  We search for the lepton-flavor-violating decay of the $J/\psi$ into an
electron and a muon using $(225.3\pm2.8)\times 10^{6}$ $J/\psi$ events
collected with the BESIII detector at the BEPCII collider. Four candidate
events are found in the signal region, consistent with background expectations.
An upper limit on the branching fraction of $\mathcal{B}(J/\psi \to e\mu)< 1.5
\times 10^{-7}$ (90% C.L.) is obtained.


title:
Multivariate Generalized Gaussian Distribution: Convexity and Graphical
  Models

abstract:
  We consider covariance estimation in the multivariate generalized Gaussian
distribution (MGGD) and elliptically symmetric (ES) distribution. The maximum
likelihood optimization associated with this problem is non-convex, yet it has
been proved that its global solution can be often computed via simple fixed
point iterations. Our first contribution is a new analysis of this likelihood
based on geodesic convexity that requires weaker assumptions. Our second
contribution is a generalized framework for structured covariance estimation
under sparsity constraints. We show that the optimizations can be formulated as
convex minimization as long the MGGD shape parameter is larger than half and
the sparsity pattern is chordal. These include, for example, maximum likelihood
estimation of banded inverse covariances in multivariate Laplace distributions,
which are associated with time varying autoregressive processes.


title:
Continuous-wave coherent imaging with terahertz quantum cascade lasers
  using electro-optic harmonic sampling

abstract:
  We demonstrate a coherent imaging system based on a terahertz (THz) frequency
quantum cascade laser (QCL) phase-locked to a near-infrared fs-laser comb. The
phase locking enables coherent electro-optic sampling of the continuous-wave
radiation emitted by the QCL through the generation of a heterodyne beat-note
signal. We use this beat-note signal to demonstrate raster scan coherent
imaging using a QCL emitting at 2.5 THz. At this frequency the detection noise
floor of our system is of 3 pW/Hz and the long-term phase stability is <3
degrees/h, limited by the mechanical stability of the apparatus.


title: From Constraints to Resolution Rules, Part I: Conceptual Framework

abstract:
  Many real world problems naturally appear as constraints satisfaction
problems (CSP), for which very efficient algorithms are known. Most of these
involve the combination of two techniques: some direct propagation of
constraints between variables (with the goal of reducing their sets of possible
values) and some kind of structured search (depth-first, breadth-first,...).
But when such blind search is not possible or not allowed or when one wants a
'constructive' or a 'pattern-based' solution, one must devise more complex
propagation rules instead. In this case, one can introduce the notion of a
candidate (a 'still possible' value for a variable). Here, we give this
intuitive notion a well defined logical status, from which we can define the
concepts of a resolution rule and a resolution theory. In order to keep our
analysis as concrete as possible, we illustrate each definition with the well
known Sudoku example. Part I proposes a general conceptual framework based on
first order logic; with the introduction of chains and braids, Part II will
give much deeper results.


title:
Improvement studies on neutron-gamma separation in HPGe detectors by
  using neural networks

abstract:
  The neutrons emitted in heavy-ion fusion-evaporation (HIFE) reactions
together with the gamma-rays cause unwanted backgrounds in gamma-ray spectra.
Especially in the nuclear reactions, where relativistic ion beams (RIBs) are
used, these neutrons are serious problem. They have to be rejected in order to
obtain clearer gamma-ray peaks. In this study, the radiation energy and three
criteria which were previously determined for separation between neutron and
gamma-rays in the HPGe detectors have been used in artificial neural network
(ANN) for improving of the decomposition power. According to the preliminary
results obtained from ANN method, the ratio of neutron rejection has been
improved by a factor of 1.27 and the ratio of the lost in gamma-rays has been
decreased by a factor of 0.50.


title:
From Constraints to Resolution Rules, Part II: chains, braids,
  confluence and T&E

abstract:
  In this Part II, we apply the general theory developed in Part I to a
detailed analysis of the Constraint Satisfaction Problem (CSP). We show how
specific types of resolution rules can be defined. In particular, we introduce
the general notions of a chain and a braid. As in Part I, these notions are
illustrated in detail with the Sudoku example - a problem known to be
NP-complete and which is therefore typical of a broad class of hard problems.
For Sudoku, we also show how far one can go in 'approximating' a CSP with a
resolution theory and we give an empirical statistical analysis of how the
various puzzles, corresponding to different sets of entries, can be classified
along a natural scale of complexity. For any CSP, we also prove the confluence
property of some Resolution Theories based on braids and we show how it can be
used to define different resolution strategies. Finally, we prove that, in any
CSP, braids have the same solving capacity as Trial-and-Error (T&E) with no
guessing and we comment this result in the Sudoku case.


title: Qualitative Analysis of Rupture Solutions for an MEMS Problem

abstract:
  We prove a sharp H\"older continuity estimates of rupture sets for sequences
of solutions of the following nonlinear problem with negative exponent $$
\Delta u= \frac{1}{u^p}, \ p>1, \ \mbox{in} \ \Omega .$$ As a consequence, we
prove the existence of rupture solutions with isolated ruptures in a bounded
convex domain in $\R^2$.


title: Eigenvalues of the Witten-Laplacian on compact Riemannian manifolds

abstract:
  In this paper we study eigenvalues of the closed eigenvalue problem of the
Witten-Laplacian on an $n$-dimensional compact Riemannian manifold. Estimates
for eigenvalues are given. As applications, we give a sharp upper bound for the
$k^{\text{th}}$ eigenvalue and for isoparametric minimal hypersurfaces in the
unit sphere, an explicit upper bound of the $(n+3)^{\text{th}}$ eigenvalue of
the Laplacian is obtained. Furthermore, we generalize the Reilly's result on
the first eigenvalue of the Laplacian.


title: The AuScope Geodetic VLBI Array

abstract:
  The AuScope geodetic Very Long Baseline Interferometry array consists of
three new 12 m radio telescopes and a correlation facility in Australia. The
telescopes at Hobart (Tasmania), Katherine (Northern Territory) and Yarragadee
(Western Australia) are co-located with other space geodetic techniques
including Global Navigation Satellite Systems (GNSS) and gravity
infrastructure, and in the case of Yarragadee, Satellite Laser Ranging (SLR)
and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS)
facilities. The correlation facility is based in Perth (Western Australia).
  This new facility will make significant contributions to improving the
densification of the International Celestial Reference Frame in the Southern
Hemisphere, and subsequently enhance the International Terrestrial Reference
Frame through the ability to detect and mitigate systematic error. This,
combined with the simultaneous densification of the GNSS network across
Australia will enable the improved measurement of intraplate deformation across
the Australian tectonic plate.
  In this paper we present a description of this new infrastructure and present
some initial results, including telescope performance measurements and
positions of the telescopes in the International Terrestrial Reference Frame.
We show that this array is already capable of achieving centimetre precision
over typical long-baselines and that network and reference source systematic
effects must be further improved to reach the ambitious goals of VLBI2010.