title:
Stability of 3D Gaussian vortices in an unbounded, rotating,
  vertically-stratified, Boussinesq flow: Linear analysis

abstract:
  The linear stability of three-dimensional (3D) vortices in rotating,
stratified flows has been studied by analyzing the non-hydrostatic inviscid
Boussinesq equations. We have focused on a widely-used model of geophysical and
astrophysical vortices, which assumes an axisymmetric Gaussian structure for
pressure anomalies in the horizontal and vertical directions. For a range of
Rossby number ($-0.5 < Ro < 0.5$) and Burger number ($0.02 < Bu < 2.3$)
relevant to observed long-lived vortices, the growth rate and spatial structure
of the most unstable eigenmodes have been numerically calculated and presented
as a function of $Ro-Bu$. We have found neutrally-stable vortices only over a
small region of the $Ro-Bu$ parameter space: cyclones with $Ro \sim 0.02-0.05$
and $Bu \sim 0.85-0.95$. However, we have also found that anticyclones in
general have slower growth rates compared to cyclones. In particular, the
growth rate of the most unstable eigenmode for anticyclones in a large region
of the parameter space (e.g., $Ro<0$ and $0.5 \lesssim Bu \lesssim 1.3$) is
slower than $50$ turn-around times of the vortex (which often corresponds to
several years for ocean eddies). For cyclones, the region with such slow growth
rates is confined to $0<Ro<0.1$ and $0.5 \lesssim Bu \lesssim 1.3$. While most
calculations have been done for $f/\bar{N}=0.1$ (where $f$ and $\bar{N}$ are
the Coriolis and background Brunt-V\"ais\"al\"a frequencies), we have
numerically verified and explained analytically, using non-dimensionalized
equations, the insensitivity of the results to reducing $f/\bar{N}$ to the more
ocean-relevant value of $0.01$. The results of this paper provide a
steppingstone to study the more complicated problems of the stability of
geophysical (e.g., those in the atmospheres of giant planets) and astrophysical
vortices (in accretion disks).


title: Controlling Chaotic Maps by Feedback Control Modulation

abstract:
  This paper deals whith the stabilization of any UPO of a chaotic map by
modulation of a control parameter. It concentrates on proportional and delayed
feedback control methods. Alternative types of these methods are proposed and
their achievments are investigated analyticaly and numerically.


title:
Role of Pressure in the Growth of Hexagonal Boron Nitride Thin Films
  from Ammonia-Borane

abstract:
  We analyze the optical, chemical, and electrical properties of chemical vapor
deposition (CVD) grown hexagonal boron nitride (h-BN) using the precursor
ammonia-borane ($H_3N-BH_3$) as a function of $Ar/H_2$ background pressure
($P_{TOT}$). Films grown at $P_{TOT}$ less than 2.0 Torr are uniform in
thickness, highly crystalline, and consist solely of h-BN. At larger $P_{TOT}$,
with constant precursor flow, the growth rate increases, but the resulting h-BN
is more amorphous, disordered, and $sp^3$ bonded. We attribute these changes in
h-BN grown at high pressure to incomplete thermolysis of the $H_3N-BH_3$
precursor from a passivated Cu catalyst. A similar increase in h-BN growth rate
and amorphization is observed even at low $P_{TOT}$ if the $H_3N-BH_3$ partial
pressure is initially greater than the background pressure $P_{TOT}$ at the
beginning of growth. h-BN growth using the $H_3N-BH_3$ precursor reproducibly
can give large-area, crystalline h-BN thin films, provided that the total
pressure is under 2.0 Torr and the precursor flux is well-controlled.


title: Segmentation of real algebraic plane curves

abstract:
  In this article we give an implementation of the standard algorithm to
segment a real algebraic plane curve defined implicitly. Our implementation is
efficient and simpler than previous. We use global information to count the
number of half-branches at a critical point.


title: Self-expressive Dictionary Learning for Dynamic 3D Reconstruction

abstract:
  We target the problem of sparse 3D reconstruction of dynamic objects observed
by multiple unsynchronized video cameras with unknown temporal overlap. To this
end, we develop a framework to recover the unknown structure without sequencing
information across video sequences. Our proposed compressed sensing framework
poses the estimation of 3D structure as the problem of dictionary learning,
where the dictionary is defined as an aggregation of the temporally varying 3D
structures. Given the smooth motion of dynamic objects, we observe any element
in the dictionary can be well approximated by a sparse linear combination of
other elements in the same dictionary (i. e. self-expression). Moreover, the
sparse coefficients describing a locally linear 3D structural interpolation
reveal the local sequencing information. Our formulation optimizes a biconvex
cost function that leverages a compressed sensing formulation and enforces both
structural dependency coherence across video streams, as well as motion
smoothness across estimates from common video sources. We further analyze the
reconstructability of our approach under different capture scenarios, and its
comparison and relation to existing methods. Experimental results on large
amounts of synthetic data as well as real imagery demonstrate the effectiveness
of our approach.


title:
On sensitivity to initial conditions and uniqueness of conjugacies for
  structurally stable diffeomorphisms

abstract:
  In this paper we study $C^1$-structurally stable diffeomorphisms, that is,
$C^1$ Axiom A diffeomorphisms with the strong transversality condition. In
contrast to the case of dynamics restricted to a hyperbolic basic piece,
structurally stable diffeomorphisms are in general not expansive and the
conjugacies between $C^1$-close structurally stable diffeomorphisms may be
non-unique, even if there are assumed $C^0$-close to the identity. Here we give
a necessary and sufficient condition for a structurally stable diffeomorphism
to admit a dense subset of points with expansiveness and sensitivity to initial
conditions. Morever, we prove that the set of conjugacies between elements in
the same conjugacy class is homeomorphic to the $C^0$-centralizer of the
dynamics. Finally, we use this fact to deduce that any two $C^1$-close
structurally stable diffeomorphismsare conjugated by a unique conjugacy
$C^0$-close to the identity if and only if these are Anosov.


title:
ROSIE: Runtime Optimization of SPARQL Queries Using Incremental
  Evaluation

abstract:
  Relational databases are wildly adopted in RDF (Resource Description
Framework) data management. For efficient SPARQL query evaluation, the legacy
query optimizer needs reconsiderations. One vital problem is how to tackle the
suboptimal query plan caused by error-prone cardinality estimation. Consider
the schema-free nature of RDF data and the Join-intensive characteristic of
SPARQL query, determine an optimal execution order before the query actually
evaluated is costly or even infeasible, especially for complex queries on
large-scale data. In this paper, we propose ROSIE, a Runtime Optimization
framework that iteratively re-optimize SPARQL query plan according to the
actual cardinality derived from Incremental partial query Evaluation. By
introducing an approach for heuristic-based plan generation, as well as a
mechanism to detect cardinality estimation error at runtime, ROSIE relieves the
problem of biased cardinality propagation in an efficient way, and thus is more
resilient to complex query evaluation. Extensive experiments on real and
benchmark data show that compared to the state-of-the-arts, ROSIE consistently
outperformed on complex queries by orders of magnitude.


title:
Regularizing Random Points: Complementary Mat\'ern Hard-Core Point
  Process

abstract:
  In this paper we present a tractable approach for regularizing randomly
placed points, by splitting them into two subsets: the first is generated by
means of the Mat\'ern hard-core point process, while the remaining points
constitute the complementary Mat\'ern hard-core point process. We study the
characteristics of these processes, deriving its pair-correlation functions,
and the distribution of the distance to the nearest neighbour. The results have
several applications in wireless communications, including the modeling of
wireless sensor networks, where we investigate an example of regularizing such
networks and illustrate its advantage in reducing the energy consumption of
wireless nodes.


title: Toda chain from the kink-antikink lattice

abstract:
  In this paper, we have studied the kink and antikink solutions in several
neutral scalar models in 1+1 dimension. We follow the standard approach to
write down the leading order and the second order force between long distance
separated kink and antikink. The leading order force is proportional to
exponential decay with respect to the distance between the two nearest kinks or
antikinks. The second order force have a similar behavior with the larger decay
factor, namely $3\over 2$. We make use of these properties to construct the
kink lattice. The dynamics of the kink lattice with leading order force can be
identified as ordinary nonperiodic Toda lattice. Also the periodic Toda lattice
can be obtained when the number of kink lattice is even. The system of kink
lattice with force up to the next order corresponds to a new specific
deformation of Toda lattice system. There is no well study on this deformation
in the integrable literatures.We found that the deformed Toda system are near
integrable system, since the integrability are hindered by high order
correction terms. Our work provides a effective theory for kink interactions
and a new near or quasi integrable model.


title:
Decidable models of integer-manipulating programs with recursive
  parallelism (technical report)

abstract:
  We study safety verification for multithreaded programs with recursive
parallelism (i.e. unbounded thread creation and recursion) as well as unbounded
integer variables. Since the threads in each program configuration are
structured in a hierarchical fashion, our model is state-extended ground-tree
rewrite systems equipped with shared unbounded integer counters that can be
incremented, decremented, and compared against an integer constant. Since the
model is Turing-complete, we propose a decidable underapproximation. First,
using a restriction similar to context-bounding, we underapproximate the global
control by a weak global control (i.e. DAGs possibly with self-loops), thereby
limiting the number of synchronisations between different threads. Second, we
bound the number of reversals between non-decrementing and non-incrementing
modes of the counters. Under this restriction, we show that reachability
becomes NP-complete. In fact, it is poly-time reducible to satisfaction over
existential Presburger formulas, which allows one to tap into highly optimised
SMT solvers. Our decidable approximation strictly generalises known decidable
models including (i) weakly-synchronised ground-tree rewrite systems, and (ii)
synchronisation/reversal-bounded concurrent pushdown systems systems with
counters. Finally, we show that, when equipped with reversal-bounded counters,
relaxing the weak control restriction by the notion of senescence results in
undecidability.


title:
Soft X-ray Absorption Spectroscopy Study of Multiferroic Bi-substituted
  Ba(1-x)Bi(x)Ti(0.9)Fe(0.1)O(3)

abstract:
  The electronic structures of multiferroic oxides of
Ba(1-x)Bi(x)Ti(0.9)Fe(0.1)O(3) (0 < x < 0.12) have been investigated by
employing photoemission spectroscopy and soft x-ray absorption spectroscopy
(XAS). The measured Fe and Ti 2p XAS spectra show that Ti ions are in the Ti4+
states for all x and that Fe ions are Fe2+-Fe3+ mixed-valent for x > 0. The
valence states of Fe ions are found to be nearly trivalent for x=0, and
decreases with increasing x from being nearly trivalent (v(Fe)~ 3) for x=0 to
v(Fe)~ 2.6 for x=0.12. The valence states of both Ti and Ba ions do not change
for all x < 0.12. Based on the obtained valence states of Fe ions, the
electronic and magnetic properties of Ba(1-x)Bi(x)Ti(0.9)Fe(0.1)O(3) are
explored.


title:
Theory of storage and retrieval of intense-broadband pulses at room
  temperature: analytical and numerical solutions

abstract:
  We analyze the storage and retrieval of intense-broadband pulses with the
added effects of Doppler broadening and detuning in a $\Lambda$ configuration.
We compute analytical solutions via the inverse scattering technique and show
how the signal field is transferred to a spin-wave in the atomic medium and
later retrieved by the interaction of a control pulse. Due to the intensity of
the pulses, the pulse area (as defined for self-induced transparency) plays a
key role in the interaction, as it determines the location of the spin wave
within the medium. Additionally, we compare our results to non-ideal conditions
by considering pulses of finite length and the effect of spontaneous emission.


title:
Predicted value of $0 \, \nu \beta \beta$-decay effective Majorana mass
  with error of lightest neutrino mass

abstract:
  Assuming that the lightest neutrino mass $ m_0 $ is measured, we study the
influence of error of the measured $ m_0 $ on the uncertainty of the predicted
value of the neutrinoless double beta decay ($0 \, \nu \beta \beta$) effective
Majorana mass $ \vert m_{ee} \vert $. The error of the predicted value of
effective Majorana mass $ \sigma ( \vert m_{ee} \vert ) $ due to the error $
\sigma (m_0) $ is obtained by use of the propagation of errors. We investigate
in detail how $ \sigma ( \vert m_{ee} \vert ) $ behaves when the Majorana
phases $ \beta $ and $ \alpha $ change, and also when the size of the lightest
neutrino mass changes. It is shown that $ \sigma ( \vert m_{ee} \vert ) $ does
not exceed $ \sigma (m_0) $, and that the minimum value of $ \sigma ( \vert
m_{ee} \vert ) $ in the $ \beta - \alpha $ plane can be zero if the size of $
m_0 $ is rather small. In the normal mass ordering case, the maximum value of $
\sigma ( \vert m_{ee} \vert ) $ in the $ \beta - \alpha $ plane becomes about $
0.68 \, \sigma (m_0) $ if $ m_0 (= m_1 ) $ is very small, while in the inverted
mass ordering case, it becomes about $ 0.02 \, \sigma (m_0) $ if $ m_0 (= m_3 )
$ is very small. By use of the calculated $ \sigma ( \vert m_{ee} \vert ) $, we
also discuss the minimum condition for the relative error of the lightest
neutrino mass to raise the possibility of obtaining the information on $ \beta
$ and $ \alpha $.


title: Stable windings at the origin

abstract:
  In 1996, Bertoin and Werner [5] demonstrated a functional limit theorem,
characterising the windings of pla- nar isotropic stable processes around the
origin for large times, thereby complementing known results for planar Brownian
mo- tion. The question of windings at small times can be handled us- ing
scaling. Nonetheless we examine the case of windings at the the origin using
new techniques from the theory of self-similar Markov processes. This allows us
to understand upcrossings of (not necessarily symmetric) stable processes over
the origin for large and small times in the one-dimensional setting.


title: Numerical analysis of a hysteresis model in perovskite solar cells

abstract:
  Previously, we proposed that the polarization and capacitive charge in
\ce{CH3NH3PbI3} screens the external electric field that hinders charge
transport. We argue here that this screening effect is in significant part
responsible for the power conversion characteristics and hysteresis in
\ce{CH3NH3PbI3} photovoltaic cells. In this paper, we implement capacitive
charge and polarization charge into the numerical model that we have developed
for perovskite solar cells. Fields induced by these two charges screen the
applied hindering field, promote charge transport, and improve solar cell's
performance, especially in solar cells with short diffusion lengths. This is
the reason why perovskite solar cells made from simple fabrication methods can
achieve high performance. More importantly, with relaxations of capacitive
charge and polarization charge, we quantitatively reproduce experimental
"anomalous" hysteresis J-V curves. This reveals that both polarization
relaxation and ions relaxation could contribute to anomalous hysteresis in
perovskite solar cells.


title:
A new pair of non-cobordant surface-links which the Orr invariant, the
  Cochran sequence, the Sato-Levine invariant, and the alinking number cannot
  find

abstract:
  We submit a new way to detect pairs of non-cobordant surface-links. We find a
new example of a pair of non-cobordant surface-links with the following
properties: Orr invariant, Cochran sequence, Sato-Levine invariant, the
alinking number and one of Stallings's theorems cannot distinguish them.
However our new way can distinguish them.


title: Transport in quantum spin Hall edges in contact to a quantum dot

abstract:
  We study the transport mechanisms taking place in a quantum spin Hall bar
with an embedded quantum dot, where electrons localize and experience Coulomb
interaction U as well as spin-flip processes {\lambda}. We solve the problem
with non-equilibrium Green functions. We focus on the linear response regime
and treat the many-body interactions with quantum Monte Carlo. The effects of U
and {\lambda} are competitive and the induced transport takes place through
different channels. The two mechanisms can be switched by changing the
occupation of the dot with a gate voltage.


title: Three-dimensional Statistical Jet Fragmentation

abstract:
  We reproduce the distribution of the longitudinal and transverse components
of momenta of charged hadrons stemming from jets created in proton-proton
collisions at s^1/2 = 7 TeV by a statistical fragmentation model. Our
hadronization model is based on microcanonical statistics and negative binomial
multiplicity fluctuations. We describe the scale dependence of the fit
parameters of the model with formulas obtained by approximating the exact
solution of the DGLAP equation in the phi^3 theory with leading order splitting
function and 1-loop coupling.


title:
Second harmonic generation at 399 nm resonant on the
  $^{1}S_{0}-^{1}P_{1}$ transition of ytterbium using a periodically poled
  LiNbO$_{3}$ waveguide

abstract:
  We demonstrate a compact and robust method for generating a 399-nm light
resonant on the $^{1}S_{0}-^{1}P_{1}$ transition in ytterbium using a
single-pass periodically poled LiNbO$_{3}$ waveguide for second harmonic
generation (SHG). The obtained output power at 399 nm was 25 mW when a 798-nm
fundamental power of 380 mW was coupled to the waveguide. We observed no
degradation of the SHG power for 13 hours with a low power of 6 mW. The
obtained SHG light has been used as a seed light for injection locking, which
provides sufficient power for laser cooling ytterbium.


title:
Mask-CNN: Localizing Parts and Selecting Descriptors for Fine-Grained
  Image Recognition

abstract:
  Fine-grained image recognition is a challenging computer vision problem, due
to the small inter-class variations caused by highly similar subordinate
categories, and the large intra-class variations in poses, scales and
rotations. In this paper, we propose a novel end-to-end Mask-CNN model without
the fully connected layers for fine-grained recognition. Based on the part
annotations of fine-grained images, the proposed model consists of a fully
convolutional network to both locate the discriminative parts (e.g., head and
torso), and more importantly generate object/part masks for selecting useful
and meaningful convolutional descriptors. After that, a four-stream Mask-CNN
model is built for aggregating the selected object- and part-level descriptors
simultaneously. The proposed Mask-CNN model has the smallest number of
parameters, lowest feature dimensionality and highest recognition accuracy when
compared with state-of-the-arts fine-grained approaches.


title:
Using Kepler Candidates to Examine the Properties of Habitable Zone
  Exoplanets

abstract:
  An analysis of the currently known exoplanets in the habitable zones (HZs) of
their host stars is of interest in both the wake of the NASA Kepler mission and
with prospects for expanding the known planet population through future ground-
and space-based projects. In this paper we compare the empirical distributions
of the properties of stellar systems with transiting planets to those with
transiting HZ planets. This comparison includes two categories:
confirmed/validated transiting planet systems, and Kepler planet and candidate
planet systems. These two categories allow us to present quantitative analyses
on both a conservative dataset of known planets and a more optimistic and
numerous sample of Kepler candidates. Both are subject to similar instrumental
and detection biases, and vetted against false positive detections. We examine
whether the HZ distributions vary from the overall distributions in the Kepler
sample with respect to planetary radius as well as stellar mass, effective
temperature, and metallicity. We find that while the evidence is strongest in
suggesting a difference between the size distributions of planets in the HZ and
the overall size distribution, none of the statistical results provide strong
empirical evidence for HZ planets or HZ planet-hosting stars to be
significantly different from the full Kepler sample with respect to these
properties.


title:
A possible framework of the Lipkin model obeying the su(n)-algebra in
  arbitrary fermion number. II --- Two subalgebras in the su(n)-Lipkin model
  and an approach to the construction of linearly independent basis ---

abstract:
  Standing on the results for the minimum weight states obtained in the
previous paper (I), an idea how to construct the linearly independent basis is
proposed for the su(n)-Lipkin model. This idea starts in setting up m
independent su(2)-subalgebras in the cases with n=2m and n=2m+1 (m=2,3,4,...).
The original representation is re-formed in terms of the spherical tensors for
the su(n)-generators built under the su(2)-subalgebras. Through this
re-formation, the su(m)-subalgebra can be found. For constructing the linearly
independent basis, not only the su(2)-algebras but also the su(m)-subalgebra
play a central role. Some concrete results in the cases with n=2, 3, 4 and 5
are presented.


title: John Ellipsoid and the Center of Mass of a Convex Body

abstract:
  It is natural to ask whether the center of mass of a convex body $K\subset
\mathbb{R}^n$ lies in its John ellipsoid $B_K$, i.e., in the maximal volume
ellipsoid contained in $K$. This question is relevant to the efficiency of many
algorithms for convex bodies. In this paper, we obtain an unexpected negative
result. There exists a convex body $K\subset \mathbb{R}^n$ such that its center
of mass does not lie in the John ellipsoid $B_K$ inflated
$(1-C\sqrt{\frac{\log(n)} {n}})n$ times about the center of $B_K$. Moreover,
there exists a polytope $P \subset \mathbb{R}^n$ with $O(n^2)$ facets whose
center of mass is not contained in the John ellipsoid $B_P$ inflated
$O(\frac{n}{\log(n)})$ times about the center of $B_P$.


title: Distributed Local Multi-Aggregation and Centrality Approximation

abstract:
  We study local aggregation and graph analysis in distributed environments
using the message passing model. We provide a flexible framework, where each of
the nodes in a set $S$--which is a subset of all nodes in the network--can
perform a large range of common aggregation functions in its $k$-neighborhood.
We study this problem in the CONGEST model, where in each synchronous round,
every node can transmit a different (but short) message to each of its
neighbors. While the $k$-neighborhoods of nodes in $S$ might overlap and
aggregation could cause congestion in this model, we present an algorithm that
needs time $O(|S|+k)$ even when each of the nodes in $S$ performs a different
aggregation on its $k$-neighborhood. The framework is not restricted to
aggregation-trees such that it can be used for more advanced graph analysis. We
demonstrate this by providing efficient approximations of centrality measures
and approximation of minimum routing cost trees.


title:
A low-field temperature-dependent EPR signal in terraced MgO:Mn2+
  nanoparticles: an enhanced Zeeman splitting in the wide-bandgap oxide

abstract:
  Mn2+ ion doping is used as an electron paramagnetic resonance (EPR) probe to
investigate the influence of low-coordination structural defects such as step
edges at the surface of terraced (001) MgO nanoparticles on the electronic
properties. Beside the well-known hyperfine sextet of Mn2+ ions in the cubic
crystal field of MgO, an additional EPR feature with a striking non-monotonous
temperature dependent shift of the g-factor is observed in terraced
nanoparticles in the temperature range from 4K to room temperature. By linking
the difference in the temperature dependence of the Mn2+ sextet intensity in
cubic and terraced nanoparticles with the possible s-d exchange shift and
enhanced Zeeman splitting we conclude that the novel EPR feature originates
from the loosely trapped charge-compensating carriers at the abundant
structural defects at the surface of terraced nanoparticles due to their
exchange interaction with neighboring Mn2+ ions.


title:
Mobile Cloud Computing with a UAV-Mounted Cloudlet: Optimal Bit
  Allocation for Communication and Computation

abstract:
  Mobile cloud computing relieves the tension between compute-intensive mobile
applications and battery-constrained mobile devices by enabling the offloading
of computing tasks from mobiles to a remote processors. This paper considers a
mobile cloud computing scenario in which the "cloudlet" processor that provides
offloading opportunities to mobile devices is mounted on unmanned aerial
vehicles (UAVs) to enhance coverage. Focusing on a slotted communication system
with frequency division multiplexing between mobile and UAV, the joint
optimization of the number of input bits transmitted in the uplink by the
mobile to the UAV, the number of input bits processed by the cloudlet at the
UAV, and the number of output bits returned by the cloudlet to the mobile in
the downlink in each slot is carried out by means of dual decomposition under
maximum latency constraints with the aim of minimizing the mobile energy
consumption. Numerical results reveal the critical importance of an optimized
bit allocation in order to enable significant energy savings as compared to
local mobile execution for stringent latency constraints.


title: Bridging Category-level and Instance-level Semantic Image Segmentation

abstract:
  We propose an approach to instance-level image segmentation that is built on
top of category-level segmentation. Specifically, for each pixel in a semantic
category mask, its corresponding instance bounding box is predicted using a
deep fully convolutional regression network. Thus it follows a different
pipeline to the popular detect-then-segment approaches that first predict
instances' bounding boxes, which are the current state-of-the-art in instance
segmentation. We show that, by leveraging the strength of our state-of-the-art
semantic segmentation models, the proposed method can achieve comparable or
even better results to detect-then-segment approaches. We make the following
contributions. (i) First, we propose a simple yet effective approach to
semantic instance segmentation. (ii) Second, we propose an online bootstrapping
method during training, which is critically important for achieving good
performance for both semantic category segmentation and instance-level
segmentation. (iii) As the performance of semantic category segmentation has a
significant impact on the instance-level segmentation, which is the second step
of our approach, we train fully convolutional residual networks to achieve the
best semantic category segmentation accuracy. On the PASCAL VOC 2012 dataset,
we obtain the currently best mean intersection-over-union score of 79.1%. (iv)
We also achieve state-of-the-art results for instance-level segmentation.


title: Stochastic Patching Process

abstract:
  Stochastic partition models tailor a product space into a number of
rectangular regions such that the data within each region exhibit certain types
of homogeneity. Due to constraints of partition strategy, existing models may
cause unnecessary dissections in sparse regions when fitting data in dense
regions. To alleviate this limitation, we propose a parsimonious partition
model, named Stochastic Patching Process (SPP), to deal with multi-dimensional
arrays. SPP adopts an "enclosing" strategy to attach rectangular patches to
dense regions. SPP is self-consistent such that it can be extended to infinite
arrays. We apply SPP to relational modeling and the experimental results
validate its merit compared to the state-of-the-arts.


title:
Emerging giant resonant exciton induced by Ta-substitution in anatase
  TiO$_{2}$: a tunable correlation effect

abstract:
  Titanium dioxide (TiO$_2$) has rich physical properties with potential
implications in both fundamental physics and new applications. Up-to-date, the
main focus of applied research is to tune its optical properties, which is
usually done via doping and/or nano-engineering. However, understanding the
role of $d$-electrons in materials and possible functionalization of
$d$-electron properties are still major challenges. Herewith, within a
combination of an innovative experimental technique, high energy optical
conductivity, and of the state-of-the-art {\it ab initio} electronic structure
calculations, we report an emerging, novel resonant exciton in the deep
ultraviolet region of the optical response. The resonant exciton evolves upon
low concentration Ta-substitution in anatase TiO$_{2}$ films. It is
surprisingly robust and related to strong electron-electron and electron-hole
interactions. The $d$- and $f$- orbitals localization, due to Ta-substitution,
plays an unexpected role, activating strong electronic correlations and
dominating the optical response under photoexcitation. Our results shed light
on a new optical phenomenon in anatase TiO$_{2}$ films and on the possibility
of tuning electronic properties by Ta substitution.


title: Arithmetic genus of integral space curves

abstract:
  We give an estimation for the arithmetic genus of an integral space curve,
which are not contained in a surface of degree $k-1$. Our main technique is the
Bogomolov-Gieseker type inequality for $\mathbb{P}^3$ proved by Macri.


title: Generalised differences and multiplier operators in $L^2({\mathbb R})$

abstract:
  Given two real numbers, the $L^2$ functions whose Fourier transforms vanish
with a certain rapidity near the given numbers are characterised as those that
are expressible as the sum of a certain number of generalised finite
differences that is independent of the function. These generalised differences
can be regarded as approximating the appropriate powers of first order ordinary
differential operators. The upshot of this is that for operators in a certain
class of ordinary differential operators that have polynomial multipliers,
their ranges on the Sobolev spaces corresponding to the operators are those
functions expressible as a finite sum of corresponding generalised differences,
so that the latter form a weighted $L^2$ space under the Fourier transform.
There is a connection with the continuity properties of invariant forms on
$L^2$ spaces. The results presented here complement results previously obtained
for the $L^2$ space of the circle group.


title:
Electron doping evolution of the neutron spin resonance in
  NaFe$_{1-x}$Co$_{x}$As

abstract:
  Neutron spin resonance, a collective magnetic excitation coupled to
superconductivity, is one of the most prominent features shared by a broad
family of unconventional superconductors including copper oxides, iron
pnictides, and heavy fermions. In this work, we study the doping evolution of
the resonances in NaFe$_{1-x}$Co$_x$As covering the entire superconducting
dome. For the underdoped compositions, two resonance modes coexist. As doping
increases, the low-energy resonance gradually loses its spectral weight to the
high-energy one but remains at the same energy. By contrast, in the overdoped
regime we only find one single resonance, which acquires a broader width in
both energy and momentum, but retains approximately the same peak position even
when $T_c$ drops by nearly a half compared to optimal doping. These results
suggest that the energy of the resonance in electron overdoped
NaFe$_{1-x}$Co$_x$As is neither simply proportional to $T_c$ nor the
superconducting gap, but is controlled by the multi-orbital character of the
system and doped impurity scattering effect.


title:
Dimension of the singularity category of a variety with rational
  singularities

abstract:
  In this paper, we study the Rouquier dimension of the singularity category of
a variety with rational singularity. We construct an upper bound for the
dimension of $\mathrm{D}_{\mathrm{sg}}(X)$ if $X$ has at worst rational
singularities and $\dim X_{\mathrm{sing}} \leq 1$.


title:
Accelerated Randomized Mirror Descent Algorithms For Composite
  Non-strongly Convex Optimization

abstract:
  We consider the problem of minimizing the sum of an average function of a
large number of smooth convex components and a general, possibly
non-differentiable, convex function. Although many methods have been proposed
to solve this problem with the assumption that the sum is strongly convex, few
methods support the non-strongly convex case. Adding a small quadratic
regularization is a common devise used to tackle non-strongly convex problems;
however, it may cause loss of sparsity of solutions or weaken the performance
of the algorithms. Avoiding this devise, we propose an accelerated randomized
mirror descent method for solving this problem without the strongly convex
assumption. Our method extends the deterministic accelerated proximal gradient
methods of Paul Tseng and can be applied even when proximal points are computed
inexactly. We also propose a scheme for solving the problem when the component
functions are non-smooth.


title: Large transverse Hall-like signal in topological Dirac semimetal Cd3As2

abstract:
  Cadmium arsenide ($\rm Cd_3As_2$) is known for its inverted band structure
and ultra-high electron mobility. It has been theoretically predicted and also
confirmed by ARPES experiments to exhibit a 3D Dirac semimetal phase containing
degenerate Weyl nodes. From magneto-transport measurements in high quality
single crystals of $\rm Cd_3As_2$, a small effective mass $m^* \approx$ 0.05
$m_e$ is determined from the Shubnikov-de Haas (SdH) oscillations. In certain
field orientations, we find a splitting of the SdH oscillation frequency in the
FFT spectrum suggesting a possible lifting of the double degeneracy in accord
with the helical spin texture at outer and inner Fermi surfaces with opposite
chirality predicted by our \textit{ab initio} calculations. Strikingly, a large
antisymmetric magnetoresistance with respect to the applied magnetic fields is
uncovered over a wide temperature range in needle crystal of $\rm Cd_3As_2$
with its long axis along [112] crystal direction. It reveals a possible
contribution of intrinsic anomalous velocity term in the transport equation
resulting from a unique 3D Rashba-like spin splitted bands that can be obtained
from band calculations with the inclusion of Cd antisite defects.


title: DLAU: A Scalable Deep Learning Accelerator Unit on FPGA

abstract:
  As the emerging field of machine learning, deep learning shows excellent
ability in solving complex learning problems. However, the size of the networks
becomes increasingly large scale due to the demands of the practical
applications, which poses significant challenge to construct a high performance
implementations of deep learning neural networks. In order to improve the
performance as well to maintain the low power cost, in this paper we design
DLAU, which is a scalable accelerator architecture for large-scale deep
learning networks using FPGA as the hardware prototype. The DLAU accelerator
employs three pipelined processing units to improve the throughput and utilizes
tile techniques to explore locality for deep learning applications.
Experimental results on the state-of-the-art Xilinx FPGA board demonstrate that
the DLAU accelerator is able to achieve up to 36.1x speedup comparing to the
Intel Core2 processors, with the power consumption at 234mW.


title: Dense Molecular Cores Being Externally Heated

abstract:
  We present results of our study on eight dense cores, previously classified
as starless, using infrared (3-160 {\micron}) imaging observations with
\textit{AKARI} telescope and molecular line (HCN and N$_2$H$^+$) mapping
observations with \textit{KVN} telescope. Combining our results with the
archival IR to mm continuum data, we examined the starless nature of these
eight cores. Two of the eight cores are found to harbor faint protostars having
luminosity of $\sim0.3-4.4$ L$_{\odot}$. The other six cores are found to
remain as starless and probably are in a dynamically transitional state. The
temperature maps produced using multi-wavelength images show an enhancement of
about 3-6 K towards the outer boundary of these cores, suggesting that they are
most likely being heated externally by nearby stars and/or interstellar
radiation fields. Large virial parameters and an over-dominance of red
asymmetric line profiles over the cores may indicate that the cores are set
into either an expansion or an oscillatory motion, probably due to the external
heating. Most of the starless cores show coreshine effect due to the scattering
of light by the micron-size dust grains. This may imply that the age of the
cores is of the order of $\sim10^{5}$ years, being consistent with the
timescale required for the cores to evolve into an oscillatory stage due to the
external perturbation. Our observational results support the idea that the
external feedback from nearby stars and/or interstellar radiation fields may
play an important role in the dynamical evolution of the cores.


title: On fractional Schrodinger systems of Choquard type

abstract:
  In this article, we first employ the concentration compactness techniques to
prove existence and stability results of standing waves for nonlinear
fractional Schr\"{o}dinger-Choquard equation \[ i\partial_t\Psi +
(-\Delta)^{\alpha}\Psi = a |\Psi|^{s-2}\Psi+\lambda \left(
\frac{1}{|x|^{N-\beta}} \star |\Psi|^p \right)|\Psi|^{p-2}\Psi\ \ \
\mathrm{in}\ \mathbb{R}^{N+1}, \] where $N\geq 2$, $\alpha\in (0,1)$, $\beta\in
(0, N)$, $s\in (2, 2+\frac{4\alpha}{N})$, $p\in [2,
1+\frac{2\alpha+\beta}{N})$, and the constants $a, \lambda$ are nonnegative
satisfying $a+\lambda > 0.$ We then extend the arguments to establish similar
results for coupled standing waves of nonlinear fractional Schr\"{o}dinger
systems of Choquard type. The same argument works for equations with an
arbitrary number of combined nonlinearities and when $|x|^{\beta-N}$ is
replaced by a more general convolution potential $\mathcal{K}:\mathbb{R}^N\to
[0, \infty)$ under certain assumptions. The same arguments can be applied and
the results are identical for the case $\alpha=1$ as well.


title: Baryogenesis in false vacuum

abstract:
  The null result in the LHC may indicate that the standard model is not
drastically modified up to very high scales such as the GUT/string scale.
Having this in the mind, we suggest a novel leptogenesis scenario realized in
the false vacuum of the Higgs field. If the Higgs field develops a large vacuum
expectation value in the early universe, a lepton number violating process is
enhanced, which we use for baryogenesis. To demonstrate the scenario, several
models are discussed. For example, we show that the observed baryon asymmetry
is successfully generated in the standard model with higher-dimensional
operators.


title: Social and Spatial Clustering of People at Humanity's Largest Gathering

abstract:
  Macroscopic behavior of scientific and societal systems results from the
aggregation of microscopic behaviors of their constituent elements, but
connecting the macroscopic with the microscopic in human behavior has
traditionally been difficult. Manifestations of homophily, the notion that
individuals tend to interact with others who resemble them, have been observed
in many small and intermediate size settings. However, whether this behavior
translates to truly macroscopic levels, and what its consequences may be,
remains unknown. Here, we use call detail records (CDRs) to examine the
population dynamics and manifestations of social and spatial homophily at a
macroscopic level among the residents of 23 states of India at the Kumbh Mela,
a 3-month-long Hindu festival. We estimate that the festival was attended by 61
million people, making it the largest gathering in the history of humanity.
While we find strong overall evidence for both types of homophily for residents
of different states, participants from low-representation states show
considerably stronger propensity for both social and spatial homophily than
those from high-representation states. These manifestations of homophily are
amplified on crowded days, such as the peak day of the festival, which we
estimate was attended by 25 million people. Our findings confirm that
homophily, which here likely arises from social influence, permeates all scales
of human behavior.


title:
Quantum critical behavior influenced by measurement backaction in
  ultracold gases

abstract:
  Recent realizations of quantum gas microscope offer the possibility of
continuous monitoring of the dynamics of a quantum many-body system at the
single-particle level. By analyzing effective non-Hermitian Hamiltonians of
interacting bosons in an optical lattice and continuum, we demonstrate that the
backaction of quantum measurement shifts the quantum critical point and gives
rise to a unique critical phase beyond the terrain of the standard universality
class. We perform mean-field and strong-coupling-expansion analyses and show
that non-Hermitian contributions shift the superfluid--to-Mott-insulator
transition point. Using a low-energy effective field theory, we discuss
critical behavior of the one-dimensional interacting Bose gas subject to the
measurement backaction. We derive an exact ground state of the effective
non-Hermitian Hamiltonian and find a unique critical behavior beyond the
Tomonaga-Luttinger liquid universality class. We propose experimental
implementations of post-selections using quantum gas microscopes to simulate
the non-Hermitian dynamics and argue that our results can be investigated with
current experimental techniques in ultracold atoms.


title: Fast Stochastic Methods for Nonsmooth Nonconvex Optimization

abstract:
  We analyze stochastic algorithms for optimizing nonconvex, nonsmooth
finite-sum problems, where the nonconvex part is smooth and the nonsmooth part
is convex. Surprisingly, unlike the smooth case, our knowledge of this
fundamental problem is very limited. For example, it is not known whether the
proximal stochastic gradient method with constant minibatch converges to a
stationary point. To tackle this issue, we develop fast stochastic algorithms
that provably converge to a stationary point for constant minibatches.
Furthermore, using a variant of these algorithms, we show provably faster
convergence than batch proximal gradient descent. Finally, we prove global
linear convergence rate for an interesting subclass of nonsmooth nonconvex
functions, that subsumes several recent works. This paper builds upon our
recent series of papers on fast stochastic methods for smooth nonconvex
optimization [22, 23], with a novel analysis for nonconvex and nonsmooth
functions.


title:
Decomposition of the rank 3 Kac-Moody Lie algebra $F$ with respect to
  the rank 2 hyperbolic subalgebra $Fib$

abstract:
  In 1983 Feingold-Frenkel studied the structure of a rank 3 hyperbolic
Kac-Moody algebra $\mathcal{F}$ containing the affine KM algebra $A^{(1)}_1$.
In 2004 Feingold-Nicolai showed that $\mathcal{F}$ contains all rank 2
hyperbolic KM algebras with symmetric Cartan matrices,
$A=\left[\begin{array}{cc} 2 & -a \\ -a & 2 \\ \end{array}\right], a\geq 3$.
The case when $a=3$ is called $\mathcal{F}ib$ because of its connection with
the Fibonacci numbers (Feingold 1980). Some important structural results about
$\mathcal{F}$ come from the decomposition with respect to its affine subalgebra
$A^{(1)}_1$. Here we study the decomposition of $\mathcal{F}$ with respect to
its subalgebra $\mathcal{F}ib$. We find that $\mathcal{F}$ has a grading by
$\mathcal{F}ib$-level, and prove that each graded piece, $\mathcal{F}ib(m)$ for
$m\in\mathbb{Z}$, is an integrable $\mathcal{F}ib$-module. We show that for
$|m|>2$, $\mathcal{F}ib(m)$ completely reduces as a direct sum of highest- and
lowest-weight modules, and for $|m|\leq 2$, $\mathcal{F}ib(m)$ contains one
irreducible non-standard quotient module $V^{\Lambda_m}=V(m)\Big/U(m)$. We then
prove that the quotient $\mathcal{F}ib(m)\Big/V(m)$ completely reduces as a
direct sum of one trivial module (on level 0), and standard modules. We give an
algorithm for determining the inner multiplicities of any irreducible
$\mathcal{F}ib$-module, in particular the non-standard modules on levels
$|m|\leq 2$. We show that multiplicities of non-standard modules on levels
$|m|=1,2$ do not follow the Kac-Peterson recursion, but instead appear to
follow a recursion similar to Racah-Speiser. We then use results of Borcherds
and Frenkel-Lepowsky-Meurman and construct vertex algebras from the root
lattices of $\mathcal{F}$ and $\mathcal{F}ib$, and study the decomposition
within this setting.


title:
Crystallizing highly-likely subspaces that contain an unknown quantum
  state of light

abstract:
  In continuous-variable tomography, with finite data and limited computation
resources, reconstruction of a quantum state of light is performed on a
finite-dimensional subspace. No systematic method was ever developed to assign
such a reconstruction subspace---only ad hoc methods that rely on
hard-to-certify assumptions about the source and strategies. We provide a
straightforward and numerically feasible procedure to uniquely determine the
appropriate reconstruction subspace for any given unknown quantum state of
light and measurement scheme. This procedure makes use of the celebrated
statistical principle of maximum likelihood, along with other validation tools,
to grow an appropriate seed subspace into the optimal reconstruction subspace,
much like the nucleation of a seed into a crystal. Apart from using the
available measurement data, no other spurious assumptions about the source or
ad hoc strategies are invoked. As a result, there will no longer be
reconstruction artifacts present in state reconstruction, which is a usual
consequence of a bad choice of reconstruction subspace. The procedure can be
understood as the maximum-likelihood reconstruction for quantum subspaces,
which is an analog to, and fully compatible with that for quantum states.


title: Building Cyber-Physical Energy Systems

abstract:
  The built environment, as hallmark of modern society, has become one of the
key drivers of energy demand. This makes for meaningful application of novel
paradigms, such as cyber-physical systems, with large scale impact for both
primary energy consumption reduction as well as (micro-) grid stability
problems. In a bottom-up approach we analyze the drivers of CPS design,
deployment and adoption in smart buildings. This ranges from low-level embedded
and real time system challenges, instrumentation and control issues, up to ICT
security layers protecting information in a world of ubiquitous connectivity. A
modeling and predictive control framework is also discussed with outlook of
deployment for HVAC optimization to a new facility for research from our
campus.


title: PROJECTION Algorithm for Motif Finding on GPUs

abstract:
  Motif finding is one of the NP-complete problems in Computational Biology.
Existing nondeterministic algorithms for motif finding do not guarantee the
global optimality of results and are sensitive to initial parameters. To
address this problem, the PROJECTION algorithm provides a good initial estimate
that can be further refined using local optimization algorithms such as EM,
MEME or Gibbs. For large enough input (600-1000 bp per sequence) or for
challenging motif finding problems, the PROJECTION algorithm may run in an
inordinate amount of time. In this paper we present a parallel implementation
of the PROJECTION algorithm in Graphics Processing Units (GPUs) using CUDA. We
also list down several major issues we have encountered including performing
space optimizations because of the GPU's space limitations.


title: Symmetry of solutions of a mean field equation on flat tori

abstract:
  We study symmetry of solutions of the mean field equation \[ \Delta u
+\rho(\frac{Ke^u}{\int_{T_\epsilon} Ke^u} -\frac{1}{|T_\epsilon|} )=0\] on the
flat torus $T_\epsilon=[-\frac{1}{2\epsilon}, \frac{1}{2\epsilon}] \times
[-\frac{1}{2}, \frac{1}{2}]$ with $0<\epsilon \leq 1$, where $K\in
C^2({T}_\epsilon)$ is a positive function with $-\Delta \ln K \leq
\frac{\rho}{|T_\epsilon|}$ and $\rho \leq 8\pi$. We prove that if $(x_0,y_0)$
is a critical point of the function $u+ln(K)$, then $u$ is evenly symmetric
about the lines $x=x_0$ and $y=y_0$, provided $K$ is evenly symmetric about
these lines. In particular we show that all solutions are one-dimensional if
$K\equiv 1$ and $\rho \leq 8\pi$. The results are sharp and answer a conjecture
of Lin and Lucia affirmatively. We also prove some symmetry results for mean
field equations on annulus.


title: On a critical Kirchhoff problem in high dimensions

abstract:
  In this paper, we consider the following Kirchhoff problem $$ \left\{\aligned
-\bigg(a+b\int_{\Omega}|\nabla u|^2dx\bigg)\Delta u&= \lambda u^{q-1} + \mu
u^{2^*-1}, &\quad \text{in }\Omega, \\ u&>0,&\quad\text{in }\Omega,\\
u&=0,&\quad\text{on }\partial\Omega, \endaligned \right.\eqno{(\mathcal{P})} $$
where $\Omega\subset \bbr^N(N\geq4)$ is a bounded domain, $2\leq q<2^*$,
$2^*=\frac{2N}{N-2}$ is the critical Sobolev exponent and $a$, $b$, $\lambda$,
$\mu$ are positive parameters. By using the variational method, we obtain some
existence and nonexistence results to $(\mathcal{P})$ for all $N\geq4$ with
some further conditions on the parameters $a$, $b$, $\lambda$, $\mu$, which
partially improve some known results in the literatures. Furthermore, Our
result for $N=4$ and $q>2$, together with our previous works
\cite{HLW15,HLW151}, gives an almost positive answer to Neimen's open question
[J. Differential Equations, 257 (2014), 1168--1193].


title:
Electrical Transport Property of ZnO Thin Films in High H2 Pressure up
  to 20 bar

abstract:
  We have investigated the H2 pressure-dependent (from vacuum to 20 bar)
current-voltage characteristics of ZnO thin films prepared by spin coating
method. The gas pressure effect on conductance (G) was subtracted using He gas.
The G increased as applying 2 bar of H2 pressure, and then it monotonously
decreased with the further increment of H2 pressure. Using X-ray diffraction
patterns and X-ray photoelectron spectroscopy before and after H2 exposure, we
found that the H2 spillover effect plays an important role in the variation of
G of ZnO film.


title: Relaxion window

abstract:
  We investigate cosmological constraints on the original relaxion scenario
proposed by Graham, Kaplan and Rajendran. We first discuss the appropriate sign
choice of the terms in the scalar potential, when the QCD axion is the relaxion
with a relaxion-inflaton coupling proposed in the original paper. We next
derive the cosmologically consistent ranges of the mass and a coupling of the
relaxion for both the QCD relaxion and non-QCD relaxion. The mass range is
obtained by $10^{-5}$ eV $\ll m_{\phi} \lesssim 10^4$ eV. We also find that a
strong correlation between the Hubble parameter at the relaxion stabilization
and the scale $\Lambda$ of non-QCD strong dynamics, which generates the
non-perturbative relaxion cosine potential. For a higher relaxion mass, a large
scale $\Lambda$ becomes available. However, for its lower mass, $\Lambda$
should be small and constructing such a particle physics model is challenging.


title:
Unitarizability, Maurey--Nikishin factorization, and Polish groups of
  finite type

abstract:
  Let $\Gamma$ be a countable discrete group, and let $\pi\colon \Gamma\to
{\rm{GL}}(H)$ be a representation of $\Gamma$ by invertible operators on a
separable Hilbert space $H$. We show that the semidirect product group
$G=H\rtimes_{\pi}\Gamma$ is SIN ($G$ admits a two-sided invariant metric
compatible with its topology) and unitarily representable ($G$ embeds into the
unitary group $\mathcal{U}(\ell^2(\mathbb N))$), if and only if $\pi$ is
uniformly bounded, and that $\pi$ is unitarizable if and only if $G$ is of
finite type: that is, $G$ embeds into the unitary group of a II$_1$-factor.
Consequently, we show that a unitarily representable Polish SIN groups need not
be of finite type, answering a question of Sorin Popa. The key point in our
argument is an equivariant version of the Maurey--Nikishin factorization
theorem for continuous maps from a Hilbert space to the space $L^0(X,m)$ of all
measurable maps on a probability space.


title:
Ultradifferentiable functions of class $M_p^{\t,\s}$ and microlocal
  regularity

abstract:
  We study spaces of ultradifferentiable functions which contain Gevrey
classes. Although the corresponding defining sequences do not satisfy Komatsu's
condition (M.2)', we prove appropriate continuity properties under the action
of (ultra)differentiable operators. Furthermore, we study convenient
localization procedure which leads to the concept of wave-front set with
respect to our regularity conditions. As an application, we identify the
standard projections of intersections/unions of wave-front sets as singular
supports of suitable spaces of ultradifferentiable functions.


title:
A representation for the derivative with respect to the initial data of
  the solution of an SDE with a non-regular drift and a Gaussian noise

abstract:
  We consider a multidimensional SDE with a Gaussian noise and a drift vector
being a vector function of bounded variation. We prove the existence of
generalized derivative of the solution with respect to the initial conditions
and represent the derivative as a solution of a linear SDE with coefficients
depending on the initial process. The representation obtained is a natural
generalization of the expression for the derivative in the smooth case. The
theory of continuous additive functionals is used.


title: Approximations for the Caputo Derivative (I)

abstract:
  In this paper we construct approximations for the Caputo derivative of order
$1-\alpha,2-\alpha,2$ and $3-\alpha$. The approximations have weights
$0.5\left((k+1)^{-\alpha}-(k-1)^{-\alpha}\right)/\Gamma(1-\alpha)$ and
$k^{-1-\alpha}/\Gamma(-\alpha)$, and the higher accuracy is achieved by
modifying the initial and last weights using the expansion formulas for the
left and right endpoints. The approximations are applied for computing the
numerical solution of ordinary fractional differential equations. The
properties of the weights of the approximations of order $2-\alpha$ are similar
to the properties of the $L1$ approximation. In all experiments presented in
the paper the accuracy of the numerical solutions using the approximation of
order $2-\alpha$ which has weights $k^{-1-\alpha}/\Gamma(-\alpha)$ is higher
than the accuracy of the numerical solutions using the $L1$ approximation for
the Caputo derivative.


title:
An octahedral deformation with six alpha particles at the Z = 12 system,
  Mg nuclides: Third nucleons, Alpharons

abstract:
  We suggest that the emergence of a large deformation in the magnesium, Mg,
nuclides, especially at the Z = 12, N = 12, should be associated with an
octahedral deformed shape. Within the framework of molecular geometrical
symmetry, we find a possibility that the Z = 12, N = 12 system would form an
octahedral structure consisting of six points of alpha(4He) particles, yielding
the ground collectivity. With this point of view, we draw the following serial
molecular structures; the Z = 10, N = 10, 20Ne, corresponds to a hexahedral,
the Z = 8, N = 8, 16O, does to a tetrahedral, and the Z = 6, N = 6, 12C, does
to a trigonal symmetry. Moreover, the Z = 2, N = 2, 4He(alpha), fits into a
tetrahedral symmetry with four points of nucleons; two protons and two
neutrons. The enhanced deformation at Z = 12 with N > 20 would be explained by
a deformed shape related to an Ethene(Ethylene)-like skeleton with six alpha
particles. The deformation at Z = 10, with N = 10 and 12, can be interpreted as
being attributed to a hexahedral shape combined by five alpha particles as
well. By noticing that the Z = 4, N = 4 system is unstable to the ground state
under two-body system with two alpha particles, we conclude that alpha
particles, rather than the eight-protons-neutrons nucleon, govern the 8Be
stability. Accordingly, the alpha particle should be a third nucleon, like a
proton or a neutron, in a nucleus. We name it the 'Alpharon'. With this
picture, we are able to open a new gate toward understanding of nuclear
many-body systems; nucleon-nucleon interaction, shell structures,
nucleon-synthesis, and nuclear matters. We argue that nature favors three-body
systems; three quarks for a nucleon, three nucleons for a nucleus.


title: Embedding based on function approximation for large scale image search

abstract:
  The objective of this paper is to design an embedding method that maps local
features describing an image (e.g. SIFT) to a higher dimensional representation
useful for the image retrieval problem. First, motivated by the relationship
between the linear approximation of a nonlinear function in high dimensional
space and the stateof-the-art feature representation used in image retrieval,
i.e., VLAD, we propose a new approach for the approximation. The embedded
vectors resulted by the function approximation process are then aggregated to
form a single representation for image retrieval. Second, in order to make the
proposed embedding method applicable to large scale problem, we further derive
its fast version in which the embedded vectors can be efficiently computed,
i.e., in the closed-form. We compare the proposed embedding methods with the
state of the art in the context of image search under various settings: when
the images are represented by medium length vectors, short vectors, or binary
vectors. The experimental results show that the proposed embedding methods
outperform existing the state of the art on the standard public image retrieval
benchmarks.


title: Group cubization (with an appendix by Mikael Pichot)

abstract:
  We present a procedure of group cubization: It results in a group whose some
features resemble the ones of a given group, and which acts without fixed
points on a CAT(0) cubical complex. As a main application we establish lack of
Kazhdan's property (T) for Burnside groups.


title:
Efficient Hybrid White Organic Light-Emitting Diodes for Application of
  Triplet Harvesting with Simple Structure

abstract:
  In this study, we fabricated hybrid white organic light-emitting diodes
(WOLEDs) based on triplet harvesting with simple structure. All the hole
transporting material and host in emitting layer (EML) of devices were utilized
with same material by using
N,N'-di-1-naphthalenyl-N,N'-diphenyl-[1,1':4',1":4",1"'-quaterphenyl]-4,4"'-diamine
(4P-NPD) which were known to be blue fluorescent material. Simple hybrid WOLEDs
were fabricated three color with blue fluorescent and green, red phosphorescent
materials. We was investigated the effect of triplet harvesting (TH) by exciton
generation zone on simple hybrid WOLEDs. Characteristic of simple hybrid WOLEDs
were dominant hole mobility, therefore exciton generation zone was expected in
EML. Additionally, we was optimization thickness of hole transporting layer and
electron transporting layer was fabricated a simple hybrid WOLEDs. Simple
hybrid WOLED exhibits maximum luminous efficiency of 29.3 cd/A and maximum
external quantum efficiency of 11.2%. Commission Internationale de l'Eclairage
(International Commission on Illumination) coordinates of (0.45, 0.43) at about
10,000 cd/m^2.


title:
Thin annuli property and exponential distribution of return times for
  Weakly Markov systems

abstract:
  We deal with the problem of asymptotic distribution of first return times to
shrinking balls under iteration generated by a large general class of dynamical
systems called weakly Markov. Our ultimate main result is that these
distributions converge to the exponential law when the balls shrink to points.
We apply this result to many classes of smooth dynamical systems that include
conformal iterated function systems, rational functions on the Riemann sphere
$\widehat{\mathbb C}$, and transcendental meromorphic functions on the complex
plane $\mathbb{C}$. We also apply them to expanding repellers and holomorphic
endomorphisms of complex projective spaces.
  One of the key ingredients in our approach is to solve the well known, in
this field of mathematics, problem of appropriately estimating the measures of,
suitably defined, large class of geometric annuli. We successfully do it. This
problem is, in the existing literature, differently referred to by different
authors; we call it the Thick Thin Annuli Property.
  Having this property established, we prove that for non--conformal systems
the aforementioned distributions converge to the exponential one along sets of
radii whose relative Lebesgue measure converges fast to one.
  But this is not all. In the context of conformal iterated function systems,
we establish the Full Thin Annuli Property, which gives the same estimates for
all radii. ln this way, we solve a long standing problem. As a result, we prove
that the convergence to the exponential law holds along all radii for
essentially all conformal iterated function systems and, with the help of the
techniques of first return maps, for all aforementioned conformal dynamical
systems.


title: On the Roman domination number of generalized Sierpinski graphs

abstract:
  A map $f : V \rightarrow \{0, 1, 2\}$ is a Roman dominating function on a
graph $G=(V,E)$ if for every vertex $v\in V$ with $f(v) = 0$, there exists a
vertex $u$, adjacent to $v$, such that $f(u) = 2$. The weight of a Roman
dominating function is given by $f(V) =\sum_{u\in V}f(u)$. The minimum weight
of a Roman dominating function on $G$ is called the Roman domination number of
$G$. In this article we study the Roman domination number of Generalized
Sierpi\'{n}ski graphs $S(G,t)$. More precisely, we obtain a general upper bound
on the Roman domination number of $S(G,t)$ and we discuss the tightness of this
bound. In particular, we focus on the cases in which the base graph $G$ is a
path, a cycle, a complete graph or a graph having exactly one universal vertex.


title: The correlation theory of the chemical bond

abstract:
  The quantum mechanical description of the chemical bond is generally given in
terms of delocalized bonding orbitals, or, alternatively, in terms of
correlations of occupations of localised orbitals. However, in the latter case,
multiorbital correlations were treated only in terms of two-orbital
correlations, although the structure of multiorbital correlations is far
richer; and, in the case of bonds established by more than two electrons,
multiorbital correlations represent a more natural point of view. Here, for the
first time, we introduce the true multiorbital correlation theory, consisting
of a framework for handling the structure of multiorbital correlations, a
toolbox of true multiorbital correlation measures, and the formulation of the
multiorbital correlation clustering, together with an algorithm for obtaining
that. These make it possible to characterise quantitatively, how well a bonding
picture describes the chemical system. As proof of concept, we apply the theory
for the investigation of the bond structures of several molecules. We show that
the non-existence of well-defined multiorbital correlation clustering provides
a reason for debated bonding picture.

categories: quant-ph cond-mat.str-el math-ph math.MP physics.chem-ph


title:
A Thickness Dependent Enhancement of Optical Resolution in the Vicinity
  of an Epsilon-near-zero Slab

abstract:
  Recent studies reports that an epsilon-near-zero (ENZ) thin slab between a
specimen and a substrate contributes in enhancing the spatial resolution of the
optical system. Here, we investigate the ENZ thickness dependence of the
resolution enhancement. By employing the edge response function, the resolution
of the optical system is directly measured when imaging a sharp edge of a metal
film. We found that the optimum ENZ slab thickness was 700 nm and the achieved
resolution was 11 {\mu}m at the wavelength of 8 {\mu}m. Owing to the enhanced
resolution by ENZ slab, we successfully imaged the subwavelength slit arrays.


title: Generative Choreography using Deep Learning

abstract:
  Recent advances in deep learning have enabled the extraction of high-level
features from raw sensor data which has opened up new possibilities in many
different fields, including computer generated choreography. In this paper we
present a system chor-rnn for generating novel choreographic material in the
nuanced choreographic language and style of an individual choreographer. It
also shows promising results in producing a higher level compositional
cohesion, rather than just generating sequences of movement. At the core of
chor-rnn is a deep recurrent neural network trained on raw motion capture data
and that can generate new dance sequences for a solo dancer. Chor-rnn can be
used for collaborative human-machine choreography or as a creative catalyst,
serving as inspiration for a choreographer.


title: Quantitative C^1 - estimates on manifolds

abstract:
  We prove a $\mathsf{C}^1$-elliptic estimate of the form $ \sup_{B(x,r/2)}
|\mathrm{grad} (\psi) | \leq C \left\{ \sup_{B(x,r)} |\Delta \psi| +
\sup_{B(x,r)} |\psi| \right\}, $ valid on any complete Riemannian manifold $M$
and for any smooth function $\psi$ which is defined in a nighbourhood of
$B(x,r)$, with an explicit quantitative control on the constant $C=C(B(x,r))$
in terms of the curvature of the geodesic ball $B(x,r)\subset M$.


title:
Leptonic and Lepto-Hadronic Modeling of the Nov. 2010 flare from 3C
  454.3

abstract:
  In this study, we use a one-zone leptonic and a lepto-hadronic model to
investigate the multi-wavelength emission and the prominent flare of the flat
spectrum radio quasar 3C 454.3 in Nov 2010. We perform a parameter study with
both models to obtain broadband fits to the spectral energy distribution of 3C
454.3. Starting with the baseline parameters obtained from the fits, we then
investigate different flaring scenarios for both models to explain an extreme
outburst and spectral hardening of 3C 454.3 that occurred in Nov 2010. We find
that the one zone lepto-hadronic model can successfully explain both the
broadband multi-wavelength spectral energy distribution and light curves in the
optical R, Swift XRT and Fermi gamma-ray bandpasses for 3C 454.3 during
quiescence and the peak of the Nov. 2010 flare. We also find that the one-zone
leptonic model produces poor fits to the broadband spectra in the X-ray and
high energy gamma-ray band passes for the Nov. 2010 flare.


title:
Scaling approach to tight-binding transport in realistic graphene
  devices: the case of transverse magnetic focusing

abstract:
  Ultra-clean graphene sheets encapsulated between hexagonal boron nitride
crystals host two-dimensional electron systems in which low-temperature
transport is solely limited by the sample size. We revisit the theoretical
problem of carrying out microscopic calculations of non-local ballistic
transport in such micron-scale devices. By employing the Landauer-Buttiker
scattering theory, we propose a novel scaling approach to tight-binding
non-local transport in realistic graphene devices. We test our numerical method
against experimental data on transverse magnetic focusing (TMF), a textbook
example of non-local ballistic transport in the presence of a transverse
magnetic field. This comparison enables a clear physical interpretation of all
the observed features of the TMF signal, including its oscillating sign.


title:
Neural Sampling by Irregular Gating Inhibition of Spiking Neurons and
  Attractor Networks

abstract:
  A long tradition in theoretical neuroscience casts sensory processing in the
brain as the process of inferring the maximally consistent interpretations of
imperfect sensory input. Recently it has been shown that Gamma-band inhibition
can enable neural attractor networks to approximately carry out such a sampling
mechanism. In this paper we propose a novel neural network model based on
irregular gating inhibition, show analytically how it implements a Monte-Carlo
Markov Chain (MCMC) sampler, and describe how it can be used to model networks
of both neural attractors as well as of single spiking neurons. Finally we show
how this model applied to spiking neurons gives rise to a new putative
mechanism that could be used to implement stochastic synaptic weights in
biological neural networks and in neuromorphic hardware.


title:
NMR Tracing of Hyperfine-Mediated Nuclear Spin Diffusion in Fractional
  Quantum Hall Domain Phases

abstract:
  We present an enhanced diffusion of nuclear spin polarization in fractional
quantum Hall domain phases at $\nu = 2/3$. Resistively-detected NMR mediated by
electrically driven domain-wall motion is used as a probe of local nuclear
polarization, manifesting pumping-dependent signal saturation behavior. This
reveals that a relatively homogeneous polarization profile spreads even to
places distant from pinning centers of the domain walls. We attribute this to
the fact that the pumped nuclear polarization near the domain walls rapidly
diffuses into the domains where nuclei experience Knight fields on comparable
levels. The anomalous enhancement of nuclear diffusion may be interpreted in
terms of indirect hyperfine-mediated interaction between nuclear spins in the
domains.


title: MDS Codes with Progressive Engagement Property for Cloud Storage Systems

abstract:
  Fast and efficient failure recovery is a new challenge for cloud storage
systems with a large number of storage nodes. A pivotal recovery metric upon
the failure of a storage node is repair bandwidth cost which refers to the
amount of data that must be downloaded for regenerating the lost data. Since
all the surviving nodes are not always accessible, we intend to introduce a
class of maximum distance separable (MDS) codes that can be re-used when the
number of selected nodes varies yet yields close to optimal repair bandwidth.
Such codes provide flexibility in engaging more surviving nodes in favor of
reducing the repair bandwidth without redesigning the code structure and
changing the content of the existing nodes. We call this property of MDS codes
progressive engagement. This name comes from the fact that if a failure occurs,
it is shown that the best strategy is to incrementally engage the surviving
nodes according to their accessing cost (delay, number of hops, traffic load or
availability in general) until the repair-bandwidth or accessing cost
constraints are met. We argue that the existing MDS codes fail to satisfy the
progressive engagement property. We subsequently present a search algorithm to
find a new set of codes named rotation codes that has both progressive
engagement and MDS properties. Furthermore, we illustrate how the existing
permutation codes can provide progressive engagement by modifying the original
recovery scheme. Simulation results are presented to compare the repair
bandwidth performance of such codes when the number of participating nodes
varies as well as their speed of single failure recovery.


title: DroidLink: Automated Generation of Deep Links for Android Apps

abstract:
  The mobile application (app) has become the main entrance to access the
Internet on handheld devices. Unlike the Web where each webpage has a global
URL to reach directly, a specific "content page" of an app can be opened only
by exploring the app with several operations from the landing page. The
interoperability between apps is quite fixed and thus limits the value-added
"linked data" between apps. Recently, deep link has been proposed to enable
targeting and opening a specific page of an app externally with an accessible
uniform resource identifier (URI). However, implementing deep link for mobile
apps requires a lot of manual efforts by app developers, which can be very
error-prone and time-consuming. In this paper, we propose DroidLink to
automatically generating deep links for existing Android apps. We design a deep
link model suitable for automatic generation. Then we explore the transition of
pages and build a navigation graph based on static and dynamic analysis of
Android apps. Next, we realize an updating mechanism that keeps on revisiting
the target app and discover new pages, and thus generates deep links for every
single page of the app. Finally, we repackage the app with deep link supports,
but requires no additional deployment requirements. We generate deep links for
some popular apps and demonstrate the feasibility of DroidLink.


title: $\gamma_5$ in Dimensional Regularization: a Novel Approach

abstract:
  A new Dimensional Regularization of $\gamma_5$ is proposed. Cyclicity and
Lorentz covariance are enforced. The extension to generic dimension is based on
the integral representation of the trace of gamma's, presented in a previous
paper.


title: On the planar Brownian Green's function for stopping times

abstract:
  It has been known for some time that the Green's function of a planar domain
can be defined in terms of the exit time of Brownian motion, and this
definition has been extended to stopping times more general than exit times. In
this paper, we extend the notion of conformal invariance of Green's function to
analytic functions which are not injective, and use this extension to calculate
the Green's function for a stopping time defined by the winding of Brownian
motion. These considerations lead to a new proof of the Riemann mapping
theorem. We also show how this invariance can be used to deduce several
identities, including the standard infinite product representations of several
trigonometric functions.


title:
An Information Criterion for Inferring Coupling in Distributed Dynamical
  Systems

abstract:
  The behaviour of many real-world phenomena can be modelled by nonlinear
dynamical systems whereby a latent system state is observed through a filter.
We are interested in interacting subsystems of this form, which we model by a
set of coupled maps as a synchronous update graph dynamical systems.
Specifically, we study the structure learning problem for spatially distributed
dynamical systems coupled via a directed acyclic graph. Unlike established
structure learning procedures that find locally maximum posterior probabilities
of a network structure containing latent variables, our work exploits the
properties of dynamical systems to compute globally optimal approximations of
these distributions. We arrive at this result by the use of time delay
embedding theorems. Taking an information-theoretic perspective, we show that
the log-likelihood has an intuitive interpretation in terms of information
transfer.


title:
Controlling the phase locking of unstable magnetic bits for ultra-low
  power computation

abstract:
  When fabricating magnetic memories, one of the main challenges is to maintain
the bit stability while downscaling. Indeed, for magnetic volumes of a few
thousand nm3, the energy barrier between magnetic configurations becomes
comparable to the thermal energy at room temperature. Then, switches of the
magnetization spontaneously occur. These volatile, superparamagnetic
nanomagnets are generally considered useless. But what if we could use them as
low power computational building blocks? Remarkably, they can oscillate without
the need of any external dc drive, and despite their stochastic nature, they
can beat in unison with an external periodic signal. Here we show that the
phase locking of superparamagnetic tunnel junctions can be induced and
suppressed by electrical noise injection. We develop a comprehensive model
giving the conditions for synchronization, and predict that it can be achieved
with a total energy cost lower than 10-^13 J. Our results open the path to
ultra-low power computation based on the controlled synchronization of
oscillators.


title: Stable topological insulators achieved using high energy electron beams

abstract:
  Topological insulators are transformative quantum solids with
immune-to-disorder metallic surface states having Dirac band structure.
Ubiquitous charged bulk defects, however, pull the Fermi energy into the bulk
bands, denying access to surface charge transport. Here we demonstrate that
irradiation with swift ($\sim 2.5$ MeV energy) electron beams allows to
compensate these defects, bring the Fermi level back into the bulk gap, and
reach the charge neutrality point (CNP). Controlling the beam fluence we tune
bulk conductivity from \textit{p}- (hole-like) to \textit{n}-type
(electron-like), crossing the Dirac point and back, while preserving the Dirac
energy dispersion. The CNP conductance has a two-dimensional (2D) character on
the order of ten conductance quanta $G_0 =e^2/h$, and reveals, both in
Bi$_2$Te$_3$ and Bi$_2$Se$_3$, the presence of only two quantum channels
corresponding to two topological surfaces. The intrinsic quantum transport of
the topological states is accessible disregarding the bulk size.


title:
Efficient laser noise reduction by locking to an actively stabilized
  fiber interferometer with 10 km arm imbalance

abstract:
  We report a laser noise reduction method by locking it to an actively
stabilized fiber-based Mach Zehnder interferometer with 10 km optical fiber to
achieve large arm imbalance. An acousto optic modulator is used for
interferometer stabilization and heterodyne detection. The out-of-loop
frequency noise is reduced by more than 90 dB for Fourier frequency at 1 Hz.
This structure presents an efficient laser noise reduction method both at high
Fourier frequency and low Fourier frequency. The signal of stabilized laser is
transferred via a 10 km fiber link with a fractional frequency stability of
1.12 times 10-16 at 1 s. Compared with the fractional frequency stability of
that when the interferometer is not stabilized, more than one order of
magnitude is improved.


title: Eclipses of the inner satellites of Jupiter observed in 2015

abstract:
  During the 2014-2015 campaign of mutual events, we recorded ground-based
photometric observations of eclipses of Amalthea (JV) and, for the first time,
Thebe (JXIV) by the Galilean moons. We focused on estimating whether the
positioning accuracy of the inner satellites determined with photometry is
sufficient for dynamical studies. We observed two eclipses of Amalthea and one
of Thebe with the 1 m telescope at Pic du Midi Observatory using an IR filter
and a mask placed over the planetary image to avoid blooming features. A third
observation of Amalthea was taken at Saint-Sulpice Observatory with a 60 cm
telescope using a methane filter (890 nm) and a deep absorption band to
decrease the contrast between the planet and the satellites. After background
removal, we computed a differential aperture photometry to obtain the light
flux, and followed with an astrometric reduction. We provide astrometric
results with an external precision of 53 mas for the eclipse of Thebe, and 20
mas for that of Amalthea. These observation accuracies largely override
standard astrometric measurements. The (O-C)s for the eclipse of Thebe are 75
mas on the X-axis and 120 mas on the Y-axis. The (O-C)s for the total eclipses
of Amalthea are 95 mas and 22 mas, along the orbit, for two of the three
events. Taking into account the ratio of (O-C) to precision of the astrometric
results, we show a significant discrepancy with the theory established by
Avdyushev and Ban'shikova in 2008, and the JPL JUP 310 ephemeris.


title: Composite systems and state transformations in topos quantum theory

abstract:
  Topos quantum theory provides representations of quantum states as direct
generalizations of the probability distribution, namely probability valuation.
In this article, we consider extensions of a known bijective correspondence
between quantum states and probability valuations to composite systems and to
state transformations. We show that multipartite probability valuations on
composite systems have a bijective correspondence to positive over pure tensor
states, according to a candidate definition of the composite systems in topos
quantum theory. Among the multipartite probability valuations, a special
attention is placed to Markov chains which are defined by generalizing
classical Markov chains from probability theory. We find an incompatibility
between the multipartite probability valuations and a monogamy property of
quantum states, which trivializes the Markov chains to product probability
valuations. Several observations on the transformations of probability
valuations are deduced from the results on multipartite probability valuations,
through duality relations between multipartite states and state
transformations.


title:
Diagrammatic approach to cellular automata and the emergence of form
  with inner structure

abstract:
  We present a diagrammatic method to build up sophisticated cellular automata
(CAs) as models of complex physical systems. The diagrams complement the
mathematical approach to CA modeling, whose details are also presented here,
and allow CAs in rule space to be classified according to their hierarchy of
layers. Since the method is valid for any discrete operator and only depends on
the alphabet size, the resulting conclusions, of general validity, apply to CAs
in any dimension or order in time, arbitrary neighborhood ranges and topology.
We provide several examples of the method, illustrating how it can be applied
to the mathematical modeling of the emergence of order out of disorder.
Specifically, we show how the the majority CA rule can be used as a building
block to construct more complex cellular automata in which separate domains
(with substructures having different dynamical properties) are able to emerge
out of disorder and coexist in a stable manner.


title: No value restriction is needed for algebraic effects and handlers

abstract:
  We present a straightforward, sound Hindley-Milner polymorphic type system
for algebraic effects and handlers in a call-by-value calculus, which allows
type variable generalisation of arbitrary computations, not just values. This
result is surprising. On the one hand, the soundness of unrestricted
call-by-value Hindley-Milner polymorphism is known to fail in the presence of
computational effects such as reference cells and continuations. On the other
hand, many programming examples can be recast to use effect handlers instead of
these effects. Analysing the expressive power of effect handlers with respect
to state effects, we claim handlers cannot express reference cells, and show
they can simulate dynamically scoped state.


title: Single electron multiplication distribution in GEM avalanches

abstract:
  In this paper, measurement results and experimental methodology are presented
on the determination of multiplication distributions of avalanches initiated by
single electron in GEM foils. The measurement relies on the amplification of
photoelectrons by the GEM under study, which is subsequently amplified in an
MWPC for signal enhancement and readout. The intrinsic detector resolution,
namely the sigma-over-mean ratio of the multiplication. distribution is also
elaborated. Small gain dependence of the shape of the avalanche response
distribution is observed in the range of net effective gain of 15 to 100. The
distribution has an exponentially decaying tail at large amplitudes. At small
amplitudes, the applied working gas is seen to have a well visible effect on
the shape of the multiplication distribution. Equivalently, the working gas has
an influence on the intrinsic detector resolution of GEMs via suppression of
the low amplitude responses. A sigma-over-mean ratio of 0.75 was reached using
a neon based mixture, whereas other gases provided an intrinsic detector
resolution closer to 1, meaning a multiplication distribution closer to the
low-field limit exponential case.


title: Elastic Solver: Balancing Solution Time and Energy Consumption

abstract:
  Combinatorial decision problems arise in many different domains such as
scheduling, routing, packing, bioinformatics, and many more. Despite recent
advances in developing scalable solvers, there are still many problems which
are often very hard to solve. Typically the most advanced solvers include
elements which are stochastic in nature. If a same instance is solved many
times using different seeds then depending on the inherent characteristics of a
problem instance and the solver, one can observe a highly-variant distribution
of times spanning multiple orders of magnitude. Therefore, to solve a problem
instance efficiently it is often useful to solve the same instance in parallel
with different seeds. With the proliferation of cloud computing, it is natural
to think about an elastic solver which can scale up by launching searches in
parallel on thousands of machines (or cores). However, this could result in
consuming a lot of energy. Moreover, not every instance would require thousands
of machines. The challenge is to resolve the tradeoff between solution time and
energy consumption optimally for a given problem instance. We analyse the
impact of the number of machines (or cores) on not only solution time but also
on energy consumption. We highlight that although solution time always drops as
the number of machines increases, the relation between the number of machines
and energy consumption is more complicated. In many cases, the optimal energy
consumption may be achieved by a middle ground, we analyse this relationship in
detail. The tradeoff between solution time and energy consumption is studied
further, showing that the energy consumption of a solver can be reduced
drastically if we increase the solution time marginally. We also develop a
prediction model, demonstrating that such insights can be exploited to achieve
faster solutions times in a more energy efficient manor.


title:
The Role of SrTiO3 Phonon Penetrating into thin FeSe Films in the
  Enhancement of Superconductivity

abstract:
  The significant role of interfacial coupling on the superconductivity
enhancement in FeSe films on SrTiO3 has been widely recognized. But the
explicit origination of this coupling is yet to be identified. Here by surface
phonon measurements using high resolution electron energy loss spectroscopy, we
found electric field generated by Fuchs-Kliewer (F-K) phonon modes of SrTiO3
can penetrate into FeSe films and strongly interact with electrons therein. The
mode-specific electron-phonon coupling (EPC) constant for the ~92 meV F-K
phonon is ~0.25 in the single-layer FeSe on SrTiO3. With increasing FeSe
thickness, the penetrating field intensity decays exponentially, which matches
well the observed exponential decay of the superconducting gap. It is
unambiguously shown that the SrTiO3 F-K phonon penetrating into FeSe is
essential in the interfacial superconductivity enhancement.


title:
An extreme planetary system around HD219828. One long-period super
  Jupiter to a hot-neptune host star

abstract:
  With about 2000 extrasolar planets confirmed, the results show that planetary
systems have a whole range of unexpected properties. We present a full
investigation of the HD219828 system, a bright metal-rich star for which a hot
neptune has previously been detected. We used a set of HARPS, SOPHIE, and
ELODIE radial velocities to search for the existence of orbiting companions to
HD219828. A dynamical analysis is also performed to study the stability of the
system and to constrain the orbital parameters and planet masses. We announce
the discovery of a long period (P=13.1years) massive (msini=15.1MJup) companion
(HD219828c) in a very eccentric orbit (e=0.81). The same data confirms the
existence of a hot-neptune, HD219828b, with a minimum mass of 21 MEarth and a
period of 3.83days. The dynamical analysis shows that the system is stable. The
HD219828 system is extreme and unique in several aspects. First, among all
known exoplanet systems it presents an unusually high mass ratio. We also show
that systems like HD219828, with a hot neptune and a long-period massive
companion are more frequent than similar systems with a hot jupiter instead.
This suggests that the formation of hot neptunes follows a different path than
the formation of their hot jovian counterparts. The high mass, long period, and
eccentricity of HD219828c also make it a good target for Gaia astrometry as
well as a potential target for atmospheric characterisation, using direct
imaging or high-resolution spectroscopy. Astrometric observations will allow us
to derive its real mass and orbital configuration. If a transit of HD219828b is
detected, we will be able to fully characterise the system, including the
relative orbital inclinations. With a clearly known mass, HD219828c may become
a benchmark object for the range in between giant planets and brown dwarfs.


title: Dynamic Landau Theory for Supramolecular Self-Assembly

abstract:
  Although pathway-specific kinetic theories are fundamentally important to
describe and under- stand reversible polymerisation kinetics, they come in
principle at a cost of having a large number of system-specific parameters.
Here, we construct a dynamical Landau theory to describe the kinetics of
activated linear supramolecular self-assembly, which drastically reduces the
number of parameters and still describes most of the interesting and generic
behavior of the system in hand. This phenomenological approach hinges on the
fact that if nucleated, the polymerisation transition resembles a phase
transition. We are able to describe hysteresis, overshooting, undershooting and
the existence of a lag time before polymerisation takes o?, and pinpoint the
conditions required for observing these types of phenomenon in the assembly and
disassembly kinetics. We argue that the phenomenological kinetic parameter in
our theory is a pathway controller, i.e., it controls the relative weights of
the molecular pathways through which self-assembly takes place.


title:
Computing minimal free resolutions of right modules over noncommutative
  algebras

abstract:
  In this paper we propose a general method for computing a minimal free right
resolution of a finitely presented graded right module over a finitely
presented graded noncommutative algebra. In particular, if such module is the
base field of the algebra then one obtains its graded homology. The approach is
based on the possibility to obtain the resolution via the computation of
syzygies for modules over commutative algebras. The method behaves
algorithmically if one bounds the degree of the required elements in the
resolution. Of course, this implies a complete computation when the resolution
is a finite one. Finally, for a monomial right module over a monomial algebra
we provide a bound for the degrees of the non-zero Betti numbers of any single
homological degree in terms of the maximal degree of the monomial relations of
the module and the algebra.


title: Circular Coloring of Random Graphs: Statistical Physics Investigation

abstract:
  Circular coloring is a constraints satisfaction problem where colors are
assigned to nodes in a graph in such a way that every pair of connected nodes
has two consecutive colors (the first color being consecutive to the last). We
study circular coloring of random graphs using the cavity method. We identify
two very interesting properties of this problem. For sufficiently many color
and sufficiently low temperature there is a spontaneous breaking of the
circular symmetry between colors and a phase transition forwards a
ferromagnet-like phase. Our second main result concerns 5-circular coloring of
random 3-regular graphs. While this case is found colorable, we conclude that
the description via one-step replica symmetry breaking is not sufficient. We
observe that simulated annealing is very efficient to find proper colorings for
this case. The 5-circular coloring of 3-regular random graphs thus provides a
first known example of a problem where the ground state energy is known to be
exactly zero yet the space of solutions probably requires a full-step replica
symmetry breaking treatment.


title: Brownian representations of cylindrical continuous local martingales

abstract:
  In this paper we give necessary and sufficient conditions for a cylindrical
continuous local martingale to be the stochastic integral with respect to a
cylindrical Brownian motion. In particular we consider the class of cylindrical
martingales with closed operator-generated covariations. We also prove that for
every cylindrical continuous local martingale $M$ there exists a time change
$\tau$ such that $M\circ \tau$ is Brownian representable.


title: Killing spinor-valued forms and the cone construction

abstract:
  On a pseudo-Riemannian manifold $\mathcal{M}$ we introduce a system of
partial differential Killing type equations for spinor-valued differential
forms, and study their basic properties. We discuss the relationship between
solutions of Killing equations on $\mathcal{M}$ and parallel fields on the
metric cone over $\mathcal{M}$ for spinor-valued forms.


title: Shintani relation for base change: unitary and elliptic representations

abstract:
  Let $E/F$ be a cyclic extension of $p$-adic fields and $n$ a positive
integer. Arthur and Clozel constructed a base change process $\pi\mapsto \pi_E$
which associates to a smooth irreducible representation of $GL_n(F)$ a smooth
irreducible representation of $GL_n(E)$, invariant under $Gal(E/F)$. When $\pi$
is tempered, $\pi_E$ is tempered and is characterized by an identity (the
Shintani character relation) relating the character of $\pi$ to the character
of $\pi_E$ twisted by the action of $Gal(E/F)$. In this paper we show that the
Shintani relation also holds when $\pi$ is unitary or elliptic. We prove
similar results for the extension $C/R$. As a corollary we show that for a
cyclic extension $E/F$ of number fields the base change for automorphic
residual representations of the ad\`ele group $GL_n(A_F)$ respects the Shintani
relation at each place of $F$.


title: Crumpling Damaged Graphene

abstract:
  Through molecular mechanics we find that non-covalent interactions modify the
fractality of crumpled damaged graphene. Pristine graphene membranes are
damaged by adding random vacancies and carbon-hydrogen bonds. Crumpled
membranes exhibit a fractal dimension of $ 2.71 \pm 0.02$ when all interactions
between carbon atoms are considered, and $2.30 \pm 0.05$ when non-covalent
interactions are suppressed. The transition between these two values, obtained
by switching on/off the non-covalent interactions of equilibrium
configurations, is shown to be reversible and independent on thermalisation. In
order to explain this transition, we propose a theoretical model that is
compatible with our numerical findings. Finally, we also compare damaged
graphene membranes with other crumpled structures, as for instance, polymerised
membranes and paper sheets, that share similar scaling properties.


title: A Sub-Quadratic Exact Medoid Algorithm

abstract:
  We present a new algorithm, trimed, for obtaining the medoid of a set, that
is the element of the set which minimises the mean distance to all other
elements. The algorithm is shown to have, under certain assumptions, expected
run time O(N^(3/2)) in R^d where N is the set size, making it the first
sub-quadratic exact medoid algorithm for d>1. Experiments show that it performs
very well on spatial network data, frequently requiring two orders of magnitude
fewer distance calculations than state-of-the-art approximate algorithms. As an
application, we show how trimed can be used as a component in an accelerated
K-medoids algorithm, and then how it can be relaxed to obtain further
computational gains with only a minor loss in cluster quality.


title: Local and Distributed Quantum Computation

abstract:
  Experimental groups are now fabricating quantum processors powerful enough to
execute small instances of quantum algorithms and definitively demonstrate
quantum error correction that extends the lifetime of quantum data, adding
urgency to architectural investigations. Although other options continue to be
explored, effort is coalescing around topological coding models as the most
practical implementation option for error correction on realizable
microarchitectures. Scalability concerns have also motivated architects to
propose distributed memory multicomputer architectures, with experimental
efforts demonstrating some of the basic building blocks to make such designs
possible. We compile the latest results from a variety of different systems
aiming at the construction of a scalable quantum computer.


title:
Fabrication, phase formation and microstructure of Ni4Nb2O9 ceramics by
  using two-stage sintering technique

abstract:
  The potential utilization of two-stage sintering for the production of highly
dense and pure nickel diniobate (Ni4Nb2O9) ceramics with low firing temperature
was demonstrated. Effects of designed sintering conditions on phase formation,
densification and microstructure of the ceramics were characterized by X-ray
diffraction (XRD), Archimedes method and scanning electron microscopy (SEM),
respectively. It has been found that minor phase of columbite NiNb2O6 tended to
form together with the desired Ni4Nb2O9 phase, depending on sintering
conditions. The optimization of sintering conditions could lead to a
single-phase Ni4Nb2O9 ceramics with orthorhombic structure. The ceramics doubly
sintered at 950/1250 {\deg}C for 4 h exhibited maximum density value of 92%.
Microstructures with denser angular grain-packing were generally found in both
sets of the sintered Ni4Nb2O9 ceramics. However, the grains were irregular in
shape when the samples are sintered at 1050/1250 {\deg}C. Two-stage sintering
was also found to enhance ferroelectric behavior of Ni4Nb2O9 ceramic.