  Spark plasma sintering (SPS) technique is applied in combination with
hydrogen decrepitation process for the recycling of SmCo5 magnets. The SmCo5
magnets for recycling were first decrepitated by hydrogen gas of a pressure of
4 bar for 3 hours to produce decrepitated powder. This powder was then used to
prepare isotropic sintered magnets using the SPS technique, by sintering at
800-1000 oC for 1 minute. Full densification of the SPS-ed magnets was possible
at a temperature of 1000 oC. The sample sintered at 900 oC showed the best
internal coercivity (jHc) of higher than 1500 kA/m with high remanence (Br)
value of 0.47 T and energy product (BH(max)) of 43.4 kJ/m3. The properties of
the SPS-ed sample sintered at 900 oC were compared with conventionally sintered
(CVS-ed) sample prepared by using fresh SmCo5 powder. The results showed the
improvement of the magnetic properties of the SPS-ed sample in comparison to
the CVS-ed sample at room temperature, and the possibility to use the SPS-ed
sample at high temperature of 180 oC, where the sample showed good magnetic
properties of jHc of 1502 kA/m, Br of 0.44 T and BH(max) of 36.4 kJ/m3. The
microstructure and X-ray diffraction patterns of the SPS-ed and the CVS-ed
samples were studied; where the samples showed to basically consist of SmCo5
matrix phase with Sm2Co7 and Sm-oxides.


  We study the orbital angular momentum (OAM) $L_z$ in two dimensional chiral
$(p_x+ip_y)^{\nu}$-wave superfluids (SF) of $N$ fermions on a disc at zero
temperature, in terms of spectral asymmetry and spectral flow. It is shown that
$L_z=\nu N/2$ for any integer $\nu$, in the BEC regime. In contrast, in the BCS
limit, while the OAM is $L_z=N/2$ for the $p+ip$-wave SF, for chiral SF with
$\nu\geq2$, the OAM is remarkably suppressed as $L_z=N\times
O(\Delta_0/\varepsilon_F)\ll N$, where $\Delta_0$ is the gap amplitude and
$\varepsilon_F$ is the Fermi energy. We demonstrate that the difference between
the $p+ip$-wave SF and the other chiral SFs in the BCS regimes originates from
the nature of edge modes and related depairing effects.


  We propose a scheme of enhancement of Rabi coupling between two identical
atomic ensembles trapped inside an optical cavity in a membrane-in-the-middle
set up. The cavity modes dispersively interact with the ensembles and the
effective interaction between the ensembles is governed by the tunnelling rate
of the cavity modes through the oscillating membrane. We have shown that this
interaction can be made large enough such that the Rabi oscillation occurs in a
time-scale, much smaller than the relevant decay time-scales of the cavity
modes and of the membrane. We present the detailed analytical and numerical
results and assess the feasibility of the scheme using currently available
technology.


  In this note I show that a pi-1-2 singleton R of L-degree strictly between 0
and 0# can be obtained so as to be the unique solution to a pi-1-2 formula
which provably has at most one solution, in the theory ZFC+(*) where (*) has
the approximate strength of an ineffable cardinal.


  We study almost universal spacetimes - spacetimes for which the field
equations of any generalized gravity with the Lagrangian constructed from the
metric, the Riemann tensor and its covariant derivatives of arbitrary order
reduce to one single differential equation and one algebraic condition for the
Ricci scalar. We prove that all d-dimensional Kundt spacetimes of Weyl type III
and traceless Ricci type N are almost universal. Explicit examples of Weyl type
II almost universal Kundt metrics are also given. The considerable
simplification of the field equations of higher-order gravity theories for
almost universal spacetimes is then employed to study new Weyl type II, III,
and N vacuum solutions to quadratic gravity in arbitrary dimension and
six-dimensional conformal gravity. Necessary conditions for almost universal
metrics are also studied.


  We compare two major approaches to variable selection in clustering: model
selection and regularization. Based on previous results, we select the method
of Maugis et al. (2009b), which modified the method of Raftery and Dean (2006),
as a current state of the art model selection method. We select the method of
Witten and Tibshirani (2010) as a current state of the art regularization
method. We compared the methods by simulation in terms of their accuracy in
both classification and variable selection. In the first simulation experiment
all the variables were conditionally independent given cluster membership. We
found that variable selection (of either kind) yielded substantial gains in
classification accuracy when the clusters were well separated, but few gains
when the clusters were close together. We found that the two variable selection
methods had comparable classification accuracy, but that the model selection
approach had substantially better accuracy in selecting variables. In our
second simulation experiment, there were correlations among the variables given
the cluster memberships. We found that the model selection approach was
substantially more accurate in terms of both classification and variable
selection than the regularization approach, and that both gave more accurate
classifications than $K$-means without variable selection.


  Let $\mathcal{D}$ be a Hom-finite, Krull-Schmidt, 2-Calabi-Yau triangulated
category with a rigid object $R$. Let
$\Lambda=\operatorname{End}_{\mathcal{D}}R$ be the endomorphism algebra of $R$.
We introduce the notion of mutation of maximal rigid objects in the two-term
subcategory $R\ast R[1]$ via exchange triangles, which is shown to be
compatible with mutation of support $\tau$-tilting $\Lambda$-modules. In the
case that $\mathcal{D}$ is the cluster category arising from a punctured marked
surface, it is shown that the graph of mutations of support $\tau$-tilting
$\Lambda$-modules is isomorphic to the graph of flips of certain collections of
tagged arcs on the surface, which is moreover proved to be connected. As a
direct consequence, the mutation graph of support $\tau$-tilting modules over a
skew-gentle algebra is connected.


  In digital-based information boom, the fuzzy covering rough set model is an
important mathematical tool for artificial intelligence, and how to build the
bridge between the fuzzy covering rough set theory and Pawlak's model is
becoming a hot research topic. In this paper, we first present the
$\gamma-$fuzzy covering based probabilistic and grade approximation operators
and double-quantitative approximation operators. We also study the
relationships among the three types of $\gamma-$fuzzy covering based
approximation operators. Second, we propose the $\gamma^{\ast}-$fuzzy coverings
based multi-granulation probabilistic and grade lower and upper approximation
operators and multi-granulation double-quantitative lower and upper
approximation operators. We also investigate the relationships among these
types of $\gamma-$fuzzy coverings based approximation operators. Finally, we
employ several examples to illustrate how to construct the lower and upper
approximations of fuzzy sets with the absolute and relative quantitative
information.


  We consider the problem of extending a conformal metric of negative
curvature, given outside a neighbourhood of 0 in the unit disk $\DD$, to a
conformal metric of negative curvature in $\DD$. We give conditions under which
such an extension is possible, and also give obstructions to such an extension.
The methods we use are based on a maximum principle and the Ahlfors--Schwarz
Lemma. We apply these considerations to compactification of Riemann surfaces.


  Synthetic data describing coherent random fluctuations have widely been used
to validate numerical sim- ulations against experimental observations or to
examine the reliability of extracting statistical properties of plasma
turbulence via correlation functions. Estimating correlation time or lengths
based on correlation functions implicitly assumes that the observed data are
stationary and homogeneous. It is, therefore, impor- tant that synthetic data
also satisfy the stationary process and homogeneous state. Based on the
synthetic data with randomly generated moving Gaussian shaped fluctuations both
in time and space, the correlation function depending on the size of averaging
time window is analytically derived. Then, the smallest possible spatial window
size of synthetic data satisfying the stationary process and homogeneous state
is proposed, thereby reducing the computation time to generate proper synthetic
data and providing a constraint on the minimum size of simulation domains when
using synthetic diagnostics to compare with experiment. This window size is
also numerically confirmed with 1D synthetic data with various parameter scans.


  Data-driven deep learning (DL) techniques developed for automatic modulation
classification (AMC) of wireless signals are vulnerable to adversarial attacks.
This poses a severe security threat to the DL-based wireless systems,
specifically for edge applications of AMC. In this work, we address the joint
problem of developing optimized DL models that are also robust against
adversarial attacks. This enables efficient and reliable deployment of DL-based
AMC on edge devices. We first propose two optimized models using knowledge
distillation and network pruning, followed by a computationally efficient
adversarial training process to improve the robustness. Experimental results on
five white-box attacks show that the proposed optimized and adversarially
trained models can achieve better robustness than the standard (unoptimized)
model. The two optimized models also achieve higher accuracy on clean
(unattacked) samples, which is essential for the reliability of DL-based
solutions at edge applications.


  A nonlinear parabolic equation of sixth order is analyzed. The equation
arises as a reduction of a model from quantum statistical mechanics, and also
as the gradient flow of a second-order information functional with respect to
the $L^2$-Wasserstein metric. First, we prove global existence of weak
solutions for initial conditions of finite entropy by means of the
time-discrete minimizing movement scheme. Second, we calculate the
linearization of the dynamics around the unique stationary solution, for which
we can explicitly compute the entire spectrum. A key element in our approach is
a particular relation between the entropy, the Fisher information and the
second order functional that generates the gradient flow under consideration.


  A new method is proposed for the correction of confidence intervals when the
original interval does not have the correct nominal coverage probabilities in
the frequentist sense. The proposed method is general and does not require any
distributional assumptions. It can be applied to both frequentist and Bayesian
inference where interval estimates are desired. We provide theoretical results
for the consistency of the proposed estimator, and give two complex examples,
on confidence interval correction for composite likelihood estimators and in
approximate Bayesian computation (ABC), to demonstrate the wide applicability
of the new method. Comparison is made with the double-bootstrap and other
methods of improving confidence interval coverage.


  The paper presents the importance of research which characterizes the natural
forest structure for the forest management. The lessons learned in these
particular forest ecosystems can be integrated by the forest management
objectives, in order to increase the sustainability of this type of resources.
The project NATFORMAN was focused on the structure of the natural forest, thus
research methodologies and modern technology (such as Field-Map) investigation
and determination were used in order to record information on forest structural
parameters. The results obtained refer to these structural parameters and to
the possibility of transferring such information in practice, in order to
achieve forest sustainable management.


  The Ricochet experiment seeks to measure Coherent (neutral-current) Elastic
Neutrino-Nucleus Scattering using dark-matter-style detectors with sub-keV
thresholds placed near a neutrino source, such as the MIT (research) Reactor
(MITR), which operates at 5.5 MW generating approximately 2.2e18
neutrinos/second in its core. Currently, Ricochet is characterizing the
backgrounds at MITR, the main component of which comes in the form of neutrons
emitted from the core simultaneous with the neutrino signal. To characterize
this background, we wrapped Bonner cylinders around a He-3 thermal neutron
detector, whose data was then unfolded via a Markov Chain Monte Carlo (MCMC) to
produce a neutron energy spectrum across several orders of magnitude. We
discuss the resulting spectrum and its implications for deploying Ricochet at
the MITR site as well as the feasibility of reducing this background level via
the addition of polyethylene shielding around the detector setup.


  Second-order optimization approaches like the generalized Gauss-Newton method
are considered more powerful as they utilize the curvature information of the
objective function with preconditioning matrices. Albeit offering tempting
theoretical benefits, they are not easily applicable to modern deep learning.
The major reason is due to the quadratic memory and cubic time complexity to
compute the inverse of the matrix. These requirements are infeasible even with
state-of-the-art hardware. In this work, we propose Ginger, an
eigendecomposition for the inverse of the generalized Gauss-Newton matrix. Our
method enjoys efficient linear memory and time complexity for each iteration.
Instead of approximating the conditioning matrix, we directly maintain its
inverse to make the approximation more accurate. We provide the convergence
result of Ginger for non-convex objectives. Our experiments on different tasks
with different model architectures verify the effectiveness of our method. Our
code is publicly available.


  We study a certain class of bulk-boundary systems in the Batalin-Vilkovisky
(BV) formalism. We construct factorization algebras of observables for such
bulk-boundary systems, and show that these factorization algebras have a
natural Poisson bracket of cohomological degree 1.


  The probability representation of states in standard quantum mechanics where
the quantum states are associated with fair probability distributions (instead
of wave function or density matrix) is shortly commented and bibliography
related to the probability representation is given.


  We consider tunneling processes in QFT induced by collisions of elementary
particles. We propose a semiclassical method for estimating the probability of
these processes in the limit of very high collision energy. As an illustration,
we evaluate the maximum probability of induced tunneling between different
vacua in a (1+1)-dimensional scalar model with boundary interaction.


  In this thesis, we consider several aspects of over-extended and
very-extended Kac-Moody algebras in relation with theories of gravity coupled
to matter. In the first part, we focus on the occurrence of KM algebras in the
cosmological billiards. We analyse the billiards in the simplified situation of
spatially homogeneous cosmologies. The most generic cases lead to the same
algebras as those met in the general inhomogeneous case, but also sub-algebras
of the "generic" ones appear. Next, we consider particular gravitational
theories which, upon toroidal compactification to D=3 space-time dimensions,
reduce to a theory of gravity coupled to a symmetric space non-linear
sigma-model. We show that the billiard analysis gives direct information on
possible dimensional oxidations (or on their obstructions) and field content of
the oxidation endpoint. We also consider all hyperbolic Kac-Moody algebras and
completely answer the question of whether or not a specific theory exists
admitting a billiard characterised by the given hyperbolic algebra. In the
second part, we turn to the set up of such gravity-matter theories through the
building of an action explicitly invariant under a Kac-Moody group. As a first
step to include fermions, we check the compatibility of the presence of a Dirac
fermion with the (hidden duality) symmetries appearing in the toroidal
compactification down to 3 space-time dimensions. Next, we investigate how the
fermions (with spin 1/2 or 3/2) fit in the conjecture for hidden over-extended
symmetry G++. Finally, in the context of G+++ invariant actions, we derive all
the possible signatures for all the GB++ theories that can be obtained from the
conventional one (1,D-1) by "dualities" generated by Weyl reflections. This
generalizes the results obtained for E8++.


  The paper addresses problem of data allocation in two-layer computer storage
while taking into account dynamic digraph(s) over computing tasks. The basic
version of data file allocation on parallel hard magnetic disks is considered
as special bin packing model. Two problems of the allocation solution
reconfiguration (restructuring) are suggested: (i) one-stage restructuring
model, (ii) multistage restructuring models. Solving schemes are based on
simplified heuristics. Numerical examples illustrate problems and solving
schemes.


  We study real affine hypersurfaces $f\colon M\rightarrow \mathbb{R}^{2n+2}$
with an almost paracontact structure $(\varphi ,\xi,\eta)$ induced by a
$\widetilde{J}$-tangent transversal vector filed, where $\widetilde{J}$ is the
canonical paracomplex structure on $\mathbb{R}^{2n+2}$. We give a
classification of hypersurfaces for which an induced almost paracontact
structure is metric relative to the second fundamental form. Some other
properties of such hypersurfaces are also studied.


  Deep Neural Networks have shown promising classification performance when
predicting certain biomarkers from Whole Slide Images in digital pathology.
However, the calibration of the networks' output probabilities is often not
evaluated. Communicating uncertainty by providing reliable confidence scores is
of high relevance in the medical context. In this work, we compare three neural
network architectures that combine feature representations on patch-level to a
slide-level prediction with respect to their classification performance and
evaluate their calibration. As slide-level classification task, we choose the
prediction of Microsatellite Instability from Colorectal Cancer tissue
sections. We observe that Transformers lead to good results in terms of
classification performance and calibration. When evaluating the classification
performance on a separate dataset, we observe that Transformers generalize
best. The investigation of reliability diagrams provides additional insights to
the Expected Calibration Error metric and we observe that especially
Transformers push the output probabilities to extreme values, which results in
overconfident predictions.


  Motivated by the need for parametric families of rich and yet tractable
distributions in financial mathematics, both in pricing and risk management
settings, but also considering wider statistical applications, we investigate a
novel technique for introducing skewness or kurtosis into a symmetric or other
distribution. We use a "transmutation" map, which is the functional composition
of the cumulative distribution function of one distribution with the inverse
cumulative distribution (quantile) function of another. In contrast to the
Gram-Charlier approach, this is done without resorting to an asymptotic
expansion, and so avoids the pathologies that are often associated with it.
Examples of parametric distributions that we can generate in this way include
the skew-uniform, skew-exponential, skew-normal, and skew-kurtotic-normal.


  We study the cluster combinatorics of $d-$cluster tilting objects in
$d-$cluster categories. By using mutations of maximal rigid objects in
$d-$cluster categories which are defined similarly for $d-$cluster tilting
objects, we prove the equivalences between $d-$cluster tilting objects, maximal
rigid objects and complete rigid objects. Using the chain of $d+1$ triangles of
$d-$cluster tilting objects in [IY], we prove that any almost complete
$d-$cluster tilting object has exactly $d+1$ complements, compute the extension
groups between these complements, and study the middle terms of these $d+1$
triangles. All results are the extensions of corresponding results on cluster
tilting objects in cluster categories established in [BMRRT] to $d-$cluster
categories. They are applied to the Fomin-Reading's generalized cluster
complexes of finite root systems defined and studied in [FR2] [Th] [BaM1-2],
and to that of infinite root systems [Zh3].


  The top quark, discovered in 1995 by the CDF and D0 collaborations at the
Tevatron collider at Fermilab, is the heaviest known elementary particle today.
Due to its high mass and short lifetime, the top quark plays a special role in
searching for physics beyond the Standard Model. In this article, recent
results of searches for new physics in the top sector, performed by CDF and D0,
are presented. In particular, we discuss the search for ttbar resonances, for
tj resonances, the search for heavy fourth generation quarks, for dark matter
produced in association with single tops, the study of anomalous couplings, the
search for boosted top quarks as well as the analysis of Lorentz Invariance
violation in the top quark sector.


  Although stochastic gradient descent (SGD) method and its variants (e.g.,
stochastic momentum methods, AdaGrad) are the choice of algorithms for solving
non-convex problems (especially deep learning), there still remain big gaps
between the theory and the practice with many questions unresolved. For
example, there is still a lack of theories of convergence for SGD and its
variants that use stagewise step size and return an averaged solution in
practice. In addition, theoretical insights of why adaptive step size of
AdaGrad could improve non-adaptive step size of {\sgd} is still missing for
non-convex optimization. This paper aims to address these questions and fill
the gap between theory and practice. We propose a universal stagewise
optimization framework for a broad family of {\bf non-smooth non-convex}
(namely weakly convex) problems with the following key features: (i) at each
stage any suitable stochastic convex optimization algorithms (e.g., SGD or
AdaGrad) that return an averaged solution can be employed for minimizing a
regularized convex problem; (ii) the step size is decreased in a stagewise
manner; (iii) an averaged solution is returned as the final solution that is
selected from all stagewise averaged solutions with sampling probabilities {\it
increasing} as the stage number. Our theoretical results of stagewise AdaGrad
exhibit its adaptive convergence, therefore shed insights on its faster
convergence for problems with sparse stochastic gradients than stagewise SGD.
To the best of our knowledge, these new results are the first of their kind for
addressing the unresolved issues of existing theories mentioned earlier.
Besides theoretical contributions, our empirical studies show that our
stagewise SGD and ADAGRAD improve the generalization performance of existing
variants/implementations of SGD and ADAGRAD.


  Antibody-functionalized carbon nanotube devices have been suggested for use
as bacterial detectors for monitoring of food purity in transit from the farm
to the kitchen. Here we report progress towards that goal by demonstrating
specific detection of Salmonella in complex nutrient broth solutions using
nanotube transistors functionalized with covalently-bound anti-Salmonella
antibodies. The small size of the active device region makes them compatible
with integration in large-scale arrays. We find that the on-state current of
the transistor is sensitive specifically to the Salmonella concentration and
saturates at low concentration (<1000 cfu/ml). In contrast, the carrier
mobility is affected comparably by Salmonella and other bacteria types, with no
sign of saturation even at much larger concentrations (10^8 cfu/ml).


  We propose a new fast fully unsupervised method to discover semantic
patterns. Our algorithm is able to hierarchically find visual categories and
produce a segmentation mask where previous methods fail. Through the modeling
of what is a visual pattern in an image, we introduce the notion of "semantic
levels" and devise a conceptual framework along with measures and a dedicated
benchmark dataset for future comparisons. Our algorithm is composed by two
phases. A filtering phase, which selects semantical hotsposts by means of an
accumulator space, then a clustering phase which propagates the semantic
properties of the hotspots on a superpixels basis. We provide both qualitative
and quantitative experimental validation, achieving optimal results in terms of
robustness to noise and semantic consistency. We also made code and dataset
publicly available.


  Augmentation of task-oriented dialogues has followed standard methods used
for plain-text such as back-translation, word-level manipulation, and
paraphrasing despite its richly annotated structure. In this work, we introduce
an augmentation framework that utilizes belief state annotations to match turns
from various dialogues and form new synthetic dialogues in a bottom-up manner.
Unlike other augmentation strategies, it operates with as few as five examples.
Our augmentation strategy yields significant improvements when both adapting a
DST model to a new domain, and when adapting a language model to the DST task,
on evaluations with TRADE and TOD-BERT models. Further analysis shows that our
model performs better on seen values during training, and it is also more
robust to unseen values. We conclude that exploiting belief state annotations
enhances dialogue augmentation and results in improved models in n-shot
training scenarios.


  We report the result of a blinded search for Weakly Interacting Massive
Particles (WIMPs) using the majority of the SuperCDMS Soudan dataset. With an
exposure of 1690 kg days, a single candidate event is observed, consistent with
expected backgrounds. This analysis (combined with previous Ge results) sets an
upper limit on the spin-independent WIMP--nucleon cross section of $1.4 \times
10^{-44}$ ($1.0 \times 10^{-44}$) cm$^2$ at 46 GeV/$c^2$. These results set the
strongest limits for WIMP--germanium-nucleus interactions for masses $>$12
GeV/$c^2$.


  In this paper we give a symbolical formula and a cancellation-free formula
for the Schur elements associated to the simple modules of the degenerate
cyclotomic Hecke algebras. As some direct applications, we show that the Schur
elements are symmetric with respect to the natural symmetric group action and
are integral coefficients polynomials and we give a different proof of
Ariki-Mathas-Rui's criterion on the semi-simplicity of degenerate cyclotomic
Hecke algebras.


  The high luminosity that will be accumulated at the LHC will enable precise
differential measurements of the hadronic production of a top--antitop-quark
pair in association with a $\text{W}$ boson. Therefore, an accurate description
of this process is needed for realistic final states. In this work we combine
for the first time the NLO QCD and electroweak corrections to the full
off-shell $\text{t}\overline{\text{t}}{\text{W}}^+$ production at the LHC in
the three-charged-lepton channel, including all spin correlations, non-resonant
effects, and interferences. To this end, we have computed the NLO electroweak
radiative corrections to the leading QCD order as well as the NLO QCD
corrections to both the QCD and the electroweak leading orders.


  Binaries play key roles in determining stellar parameters and exploring
stellar evolution models. We build a catalog of 88 eclipsing binaries with
spectroscopic information, taking advantage of observations from both the Large
Sky Area Multi-Object fiber Spectroscopic Telescope (LAMOST) and the Palomar
Transient Factory (PTF) surveys. A software pipeline is constructed to identify
binary candidates by examining their light curves. The orbital periods of
binaries are derived from the Lomb-Scargle method. The key distinguishing
features of eclipsing binaries are recognized by a new filter \textit{Flat
Test}. We classify the eclipsing binaries by applying Fourier analysis on the
light curves. Among all the binary stars, 13 binaries are identified as
eclipsing binaries for the first time. The catalog contains information:
position, primary eclipsing magnitude and time, eclipsing depth, the number of
photometry and radial velocity observations, largest radial velocity
difference, binary type, the effective temperature of observable star $T_{\rm
eff}$, and surface gravity of observable star log \emph{g}. The false-positive
probability is calculated by using both a Monte Carlo simulation and real data
from the SDSS Stripe 82 Standard Catalog. The binaries in the catalog are
mostly with a period of less than one day. The period distribution shows a
0.22-day cut-off which is consistent with the low probability of an eclipsing
binary rotating with such a period.


  One of the most direct way to constrain the matter density of the universe
$\Omega_M$ is to measure the baryon content in X-Rays clusters of galaxies.
Typical value of the mean gas mass fraction is $\fg \sim 0.15h^{-3/2}$ which
leads to $\omM <0.4$. In this talk I will discuss the issue of the gas fraction
radial distribution inside a cluster and foccus on the apparent discrepancy
between the theoretical shape predicted by numerical simulations and the
observations. I will show that a significant part of this discrepancy is due to
several systematics in both the gas mass and total mass determinations.
Revising the gas as well as the binding masses removes such a discrepancy and
results in a lower baryon mass fraction of $\fb(r_{500}) \sim 10 %$ (Sadat &
Blanchard 2001). Finally, I will discuss the cosmological constraints we obtain
when we combine the revised baryon fraction with primordial fluctuations.


  We discuss different representations of the White noise spaces $(E)_{\beta}$,
$0 \leq \beta < 1$ by introducing generalized Wick tensors. As an application
we state a generalization of the Mehler formula for the Ornstein-Uhlenbeck
semigroup.


  2048 is an engaging single-player, nondeterministic video puzzle game, which,
thanks to the simple rules and hard-to-master gameplay, has gained massive
popularity in recent years. As 2048 can be conveniently embedded into the
discrete-state Markov decision processes framework, we treat it as a testbed
for evaluating existing and new methods in reinforcement learning. With the aim
to develop a strong 2048 playing program, we employ temporal difference
learning with systematic n-tuple networks. We show that this basic method can
be significantly improved with temporal coherence learning, multi-stage
function approximator with weight promotion, carousel shaping, and redundant
encoding. In addition, we demonstrate how to take advantage of the
characteristics of the n-tuple network, to improve the algorithmic
effectiveness of the learning process by i) delaying the (decayed) update and
applying lock-free optimistic parallelism to effortlessly make advantage of
multiple CPU cores. This way, we were able to develop the best known 2048
playing program to date, which confirms the effectiveness of the introduced
methods for discrete-state Markov decision problems.


  Recently, variational approximations such as the mean field approximation
have received much interest. We extend the standard mean field method by using
an approximating distribution that factorises into cluster potentials. This
includes undirected graphs, directed acyclic graphs and junction trees. We
derive generalized mean field equations to optimize the cluster potentials. We
show that the method bridges the gap between the standard mean field
approximation and the exact junction tree algorithm. In addition, we address
the problem of how to choose the graphical structure of the approximating
distribution. From the generalised mean field equations we derive rules to
simplify the structure of the approximating distribution in advance without
affecting the quality of the approximation. We also show how the method fits
into some other variational approximations that are currently popular.


  The advent of miniaturized biologging devices has provided ecologists with
unprecedented opportunities to record animal movement across scales, and led to
the collection of ever-increasing quantities of tracking data. In parallel,
sophisticated tools have been developed to process, visualize and analyze
tracking data, however many of these tools have proliferated in isolation,
making it challenging for users to select the most appropriate method for the
question in hand. Indeed, within the R software alone, we listed 58 packages
created to deal with tracking data or 'tracking packages'. Here we reviewed and
described each tracking package based on a workflow centered around tracking
data (i.e. spatio-temporal locations (x,y,t)), broken down into three stages:
pre-processing, post-processing and analysis, the latter consisting of data
visualization, track description, path reconstruction, behavioral pattern
identification, space use characterization, trajectory simulation and others.
Supporting documentation is key to render a package accessible for users. Based
on a user survey, we reviewed the quality of packages' documentation, and
identified 11 packages with good or excellent documentation. Links between
packages were assessed through a network graph analysis. Although a large group
of packages showed some degree of connectivity (either depending on functions
or suggesting the use of another tracking package), one third of the packages
worked in isolation, reflecting a fragmentation in the R movement-ecology
programming community. Finally, we provide recommendations for users when
choosing packages, and for developers to maximize the usefulness of their
contribution and strengthen the links within the programming community.


  Applying basic physical principles to recent observational results, we derive
upper and lower limits on microwave anisotropy from point sources over the
range of frequencies 10-1000 GHz. We examine the level of noise in the
observations as a possible indication of source confusion at subarcminute
scales. We also derive an upper limit on microwave anisotropy caused by the
sources responsible for the Far-Infrared Background radiation detected in FIRAS
data. Our upper limit on point source confusion of DeltaT/T=10^{-5} for a 10'
beam at 100 GHz would cause severe foreground contamination for CMB anisotropy
observations, although the actual contamination level is probably much lower.
This upper limit constrains the long-feared possibility of an undetected
population of sources with emission peaking near 100 GHz. Source detections
closer to 100 GHz are needed to improve our knowledge of galaxy evolution at
high redshift and to predict the level of point source confusion.


  Recently many methods have been proposed to create the vector fields, due to
the academic interest and a variety of attractive applications such as for
particle acceleration, optical trapping, particle manipulation, and
fluorescence imaging. For the most of the created vector fields, the spatial
distribution in states of polarization (SoPs) is dependent of azimuthal angle
only. It is very interesting and crucial that if we can introduce the radial
controlling freedom, which undoubtedly opens a new way to provide the
flexibility for creating the desired vector fields and for fulfilling the
requirement on a variety of applications. Here we present a new idea to create
a new kind of vector filed with the radial-variant SoPs. This idea also permits
to create flexibly vector fields with arbitrarily complex distribution of SoPs,
based on a combination of radial and azimuthal dependency. This realization in
both principle and experiment is paramount to be able to implement the focusing
engineering for applications in a variety of realms. Specially arranging the
SoPs of vector fields, purposefully and carefully, is anticipated to lead to
new effects and phenomena that can expand the functionality and enhance the
capability of optical systems, such as the optical trapping.


  Supersymmetric models with a Dirac gluino have been shown to be considerably
less constrained from LHC searches than models with a Majorana gluino. In this
paper, we generalize this discussion to models with a "Mixed Gluino", that
acquires both Dirac and Majorana masses, as well as models in which electroweak
gauginos contribute to squark production. Our primary interest is the degree of
suppression of the cross section for first generation squarks compared with a
gluino with a pure Majorana mass. We find that not all Majorana masses are
alike -- a Majorana mass for the gluino can suppress the squark production
cross section, whereas a Majorana mass for the adjoint fermion partner leads to
an increased cross section, compared with a pure Dirac gluino. In the presence
of electroweak gauginos, squark production can increase by at most a factor of
a few above the pure Dirac gluino case when the electroweak gauginos have
purely Majorana masses near to the squark masses. This unusual set of gaugino
masses is interesting since the usual Higgs quartic coupling would not be
suppressed. When the electroweak gaugino masses are much lighter than the
squarks, there is a negligible change to the squark production cross section.
We explain both of these cases in detail by considering the various
subprocesses for squark production at the LHC. Continued searches for squark
production with cross sections much smaller than expected in the MSSM are
absolutely warranted, and we suggest new simplified models to fully
characterize the collider constraints.


  Monadic decomposability is a notion of variable independence, which asks
whether a given formula in a first-order theory is expressible as a Boolean
combination of monadic predicates in the theory. Recently, Veanes et al. showed
the usefulness of monadic decomposability in the context of SMT (i.e. the input
formula is quantifier-free), and found various interesting applications
including string analysis. However, checking monadic decomposability is
undecidable in general. Decidability for certain theories is known (e.g.
Presburger Arithmetic, Tarski's Real-Closed Field), but there are very few
results regarding their computational complexity. In this paper, we study
monadic decomposability of integer linear arithmetic in the setting of SMT. We
show that this decision problem is coNP-complete and, when monadically
decomposable, a formula admits a decomposition of exponential size in the worst
case. We provide a new application of our results to string constraint solving
with length constraints. We then extend our results to variadic
decomposability, where predicates could admit multiple free variables (in
contrast to monadic decomposability). Finally, we give an application to
quantifier elimination in integer linear arithmetic where the variables in a
block of quantifiers, if independent, could be eliminated with an exponential
(instead of the standard doubly exponential) blow-up.


  The relaxation times over which dissipative fluxes restore their steady state
values have been evaluated for a pion gas using the 14-moment method. The
effect of the medium has been implemented through a temperature dependent pi-pi
cross-section in the collision integral which is obtained by including one-loop
self-energies in the propagators of the exchanged rho and sigma mesons. To
account for chemical freeze out in heavy ion collisions, a temperature
dependent pion chemical potential has been introduced in the distribution
function. The temperature dependence of the relaxation times for shear and bulk
viscous flows as well as the heat flow is significantly affected.


  This paper presents a new definition of the community structure of a network,
which takes also into account how communities are stratified. In particular, we
extend the standard concept of clustering coefficient and provide the local
$l$-adjacency clustering coefficient of a node $i$. We define it as an
opportunely weighted mean of the clustering coefficients of nodes which are at
distance $l$ from $i$. The stratus of the community associated to node $i$ is
identified by the distance $l$ from $i$, so that the standard clustering
coefficient is a peculiar local $l$-adjacency clustering coefficient at stratus
$l=0$. As the distance $l$ varies, the local $l$-adjacency clustering
coefficient is then used to infer insights on the community structure of the
entire network. Empirical experiments on special business networks are carried
out. In particular, the analysis of air traffic networks validate the
theoretical proposal and provide supporting arguments on its usefulness.


  Magnetic entropy and adiabatic temperature changes in and above the
room-temperature region has been measured for La0.7Sr0.3Mn1-xM'xO3 (M' = Al,
Ti) by means of magnetization and heat capacity measurements in magnetic fields
up to 6 T. The magnetocaloric effect becomes largest at the ferromagnetic
ordering temperature Tc that is tuned to ~300 K by the substitution of Al or Ti
for Mn. While the substitution of Al for Mn drastically reduces the entropy
change, it extends considerably the working temperature span and improves the
relative cooling power. The magnetocaloric effect seems to be only lightly
affected by Ti substitution. Although manganites have been considered potential
for magnetic refrigerants, the magnetocaloric effect in these materials is
limited due to the existence of short-range ferromagnetic correlations above
Tc.


  TThe transition temperature (TC) between normal and superconducting states
usually exhibits a dramatic increase or decrease with increasing applied
pressure. Here we present, in contrast, a new kind of superconductor that
exhibits the exotic feature that TC is robust against large volume shrinkages
induced by applied pressure (here naming them as "RSAVS superconductors").
Extraordinarily, the TC in these materials stays almost constant over a large
pressure range, e.g. over 136 GPa in the (TaNb)0.67(HfZrTi)0.33 high entropy
alloy and 141 GPa in the NbTi commercial alloy. We show that the RSAVS behavior
also exists in another high entropy alloy (ScZrNbTa)0.6(RhPd)0.4, and in
superconducting elemental Ta and Nb, indicating that this behavior, which has
never previously been identified or predicted by theory, occurs universally in
some conventional superconductors. Our electronic structure calculations
indicate that although the electronic density of state (DOS) at the Fermi level
in the RSAVS state is dominated by the electrons from the degenerate dxy, dxz
and dyz orbitals, these electrons decrease in influence with increasing
pressure. In contrast, however, the contribution of the degenerate dx2-y2 and
dz2 orbital electrons remains almost unchanged at the Fermi level, suggesting
that these are the electrons that may play a crucial role in stabilizing the TC
in the RSAVS state.


  We derive a relation for the steepening of blazar gamma-ray spectra between
the multi-GeV Fermi energy range and the TeV energy range observed by
atmospheric Cerenkov telescopes. The change in spectral index is produced by
two effects: (1) an intrinsic steepening, independent of redshift, owing to the
properties of emission and absorption in the source, and (2) a
redshift-dependent steepening produced by intergalactic pair production
interactions of blazar gamma-rays with low energy photons of the intergalactic
background light (IBL). Given this relation, with good enough data on the mean
gamma-ray SED of TeV selected BL Lacs, the redshift evolution of the IBL can,
in principle, be determined independently of stellar evolution models. We apply
our relation to the results of new Fermi observations of TeV selected blazars.


  In this paper we study the distributed average consensus problem in
multi-agent systems with directed communication links that are subject to
quantized information flow. Specifically, we present and analyze a distributed
averaging algorithm which operates exclusively with quantized values (i.e., the
information stored, processed and exchanged between neighboring agents is
subject to deterministic uniform quantization) and relies on event-driven
updates (e.g., to reduce energy consumption, communication bandwidth, network
congestion, and/or processor usage). The main idea of the proposed algorithm is
that each node (i) models its initial state as two quantized fractions which
have numerators equal to the node's initial state and denominators equal to
one, and (ii) transmits one fraction randomly while it keeps the other stored.
Then, every time it receives one or more fractions, it averages their
numerators with the numerator of the fraction it stored, and then transmits
them to randomly selected out-neighbors. We characterize the properties of the
proposed distributed algorithm and show that its execution, on any static and
strongly connected digraph, allows each agent to reach in finite time a fixed
state that is equal (within one quantisation level) to the average of the
initial states. We extend the operation of the algorithm to achieve finite-time
convergence in the presence of a dynamic directed communication topology
subject to some connectivity conditions. Finally, we provide examples to
illustrate the operation, performance, and potential advantages of the proposed
algorithm. We compare against state-of-the-art quantized average consensus
algorithms and show that our algorithm's convergence speed significantly
outperforms most existing protocols.


  We report the detection, based on HST and Keck data, of two peculiar
absorbers in the Ly-alpha forest of the quasar PKS 0454+039. These clouds, at
redshifts z=0.6248 and 0.9315 respectively, display both MgII and FeII
absorption lines in addition to the Ly-alpha line. Based upon photoionization
models, these are inferred to be photoionized by the intergalactic UV
background, and to have HI column densities in the range 15.8 < N(HI) < 16.8.
Furthermore, if one supposes that the relative abundances of heavy elements is
similar to that of depleted clouds of our galaxy, the abundances of these two
absorbers are greater than the solar value, which is a unique case for
absorbers which are not associated to the quasar. We tentatively suggest that
these absorbers may select giant low surface brightness galaxies.


  We consider the problem of learning the underlying graph of a sparse Ising
model with $p$ nodes from $n$ i.i.d. samples. The most recent and best
performing approaches combine an empirical loss (the logistic regression loss
or the interaction screening loss) with a regularizer (an L1 penalty or an L1
constraint). This results in a convex problem that can be solved separately for
each node of the graph. In this work, we leverage the cardinality constraint L0
norm, which is known to properly induce sparsity, and further combine it with
an L2 norm to better model the non-zero coefficients. We show that our proposed
estimators achieve an improved sample complexity, both (a) theoretically, by
reaching new state-of-the-art upper bounds for recovery guarantees, and (b)
empirically, by showing sharper phase transitions between poor and full
recovery for graph topologies studied in the literature, when compared to their
L1-based state-of-the-art methods.


  Pore-network models (PNMs) have become an important tool in the study of
fluid flow in porous media over the last few decades, and the accuracy of their
results highly depends on the extraction of pore networks. Traditional methods
of pore-network extraction are based on pixels and require images with high
quality. Here, a pixel-free method called the flashlight search medial axis
(FSMA) algorithm is proposed for pore-network extraction in a continuous space.
The search domain in a two-dimensional space is a line, whereas a surface
domain is searched in a three-dimensional scenario. Thus, the FSMA algorithm
follows the dimensionality reduction idea; the medial axis can be identified
using only a few points instead of calculating every point in the void space.
In this way, computational complexity of this method is greatly reduced
compared to that of traditional pixel-based extraction methods, thus enabling
large-scale pore-network extraction. Based on cases featuring two- and
three-dimensional porous media, the FSMA algorithm performs well regardless of
the topological structure of the pore network or the positions of the pore and
throat centers. This algorithm can also be used to examine both closed- and
open-boundary cases. Finally, the FSMA algorithm can search dead-end pores,
which is of great significance in the study of multiphase flow in porous media.


  The present manuscript discusses a remarkable phenomenon concerning
non-linear and non-integrable field theories in $(3+1)$-dimensions, living at
finite density and possessing non-trivial topological charges and non-Abelian
internal symmetries (both local and global). With suitable types of ans\"atze,
one can construct infinite-dimensional families of analytic solutions with
non-vanishing topological charges (representing the Baryonic number) labelled
by both two integers numbers and by free scalar fields in $(1+1)$-dimensions.
These exact configurations represent $(3+1)$-dimensional topological solitons
hosting $(1+1)$-dimensional chiral modes localized at the energy density peaks.
First, we analyze the Yang-Mills-Higgs model, in which the fields depend on all
the space-time coordinates (to keep alive the topological Chern-Simons charge),
but in such a way to reduce the equations system to the field equations of
two-dimensional free massless chiral scalar fields. Then, we move to the
non-linear sigma model, showing that a suitable ansatz reduces the field
equations to the one of a two-dimensional free massless scalar field. Then, we
discuss the Skyrme model concluding that the inclusion of the Skyrme term gives
rise to a chiral two-dimensional free massless scalar field (instead of a free
massless field in two dimensions as in the non-linear sigma model) describing
analytically spatially modulated Hadronic layers and tubes. The comparison of
the present approach both with the instantons-dyons liquid approach and with
Lattice QCD is shortly outlined.


  The Bell inequality is derived under the assumption of three physical data
sets, random or deterministic. The data sets represent a laboratory realization
of the three probability based variables used by Bell. For physical data as can
be written on paper, the derivation of the inequality results only from
principles of algebra and is independent of assumptions of locality, hidden
variables and even randomness. Cross correlations of thee data sets carried out
as Bell correlated three random variables results in the same inequality that
is identically satisfied even by deterministic data. However, to obtain three
data sets on two particles destroyed by measurement, two experimental runs are
required, followed by data matching to reduce four data sets to three. If
quantum mechanical probabilities are used to describe the data frequencies, the
Bell inequality is satisfied. The situation is analogous to performing two sets
of coin flips to compare the effect of two different coin loadings on the
probabilities for heads and tails.


  Recent works showed that the absorbing material in broad absorption line
(BAL) quasars is optically thick to major resonant absorption lines. This
material may contribute significantly to the polarization in the absorption
lines. In this paper, we present a detailed study of the resonant line
scattering process using Monte-Carlo method to constrain the optical depth, the
geometry and the kinematics of BAL Region (BALR). By comparing our results with
observed polarized spectra of BAL quasars, we find: (1) Resonant scattering can
produce polarization up to 9% at the absorption trough for doublet transitions
and up to 20% for singlet transitions in radially accelerated flows. To explain
the large polarization degree in the CIV, NV absorption line troughs detected
in a small fraction of BAL QSOs, a nonmonotonic velocity distribution along the
line of sight or/and additional contribution from the electron scattering
region is required. (2) The rotation of the flow can lead to the rotation of
the polarization position angle (PA) in the line trough. Large extending angle
of BALR is required to produce the observed large PA rotation in a few BAL
QSOs. (3) A large extending angle of BALR is required to explain a sub-trough
in the polarized flux that was observed in a number of BAL QSOs. (4) The
resonant-scattering can contribute a significant part of NV emission line in
some QSOs, and may give rise to anomalous strong NV lines in these quasars. (5)
The polarized flux and PA rotation produced by the resonant scattering in
non-BAL is uniquely asymmetric, which may be used to test the presence of BALR
in non-BAL QSOs.


  The liquid-phase exfoliation (LPE) of black phosphorus (BP) is a strategic
route for the large-scale production of phosphorene and few-layer BP (FL-BP)
flakes. The exploitation of this exfoliated material in cutting-edge
technologies, e.g., in flexible electronics and energy storage, is however
limited by the fact that the LPE of BP is usually carried out at a high boiling
point and in toxic solvents. In fact, the solvent residual is detrimental to
device performance in real applications; thus, complete solvent removal is
critical. Here, we tackle these issues by exfoliating BP in different low
boiling-point solvents. Among these solvents, we find that acetone also
provides a high concentration of exfoliated BP, leading to the production of
FL-BP flakes with an average lateral size and thickness of c.a. 30 and 7 nm,
respectively. The use of acetone to produce less defective few-layer BP flakes
(FL-BPacetone) from bulk crystals is a straightforward process which enables
the rapid preparation of homogeneous thin films thanks to the fast solvent
evaporation. The ratio of edge to bulk atoms for the BP flakes here produced,
combined with the use of low-boiling-point solvents for the exfoliation process
suggests that these thin films are promising anodes for lithium-ion batteries.
To this end, we tested Li-ion half cells with FL-BPacetone anodes achieving a
reversible specific capacity of 480 mAh/g at a current density of 100 mA/g,
over 100 charge/discharge cycles. Moreover, a reversible specific capacity of
345 mAh/g is achieved for the FL-BPacetone-based anode at a high current
density (i.e., 1 A/g). These findings indicate that the FL-BPacetone-based
battery is promising with regards to the design of fast charge/discharge
devices. Overall, the presented process is a step forward toward the
fabrication of phosphorene-based devices.


  Fragmentation of a spiral arm is thought to drive the formation of giant
clumps in galaxies. Using linear perturbation analysis for self-gravitating
spiral arms, we derive an instability parameter and define the conditions for
clump formation. We extend our analysis to multi-component systems that consist
of gas and stars in an external potential. We then perform numerical
simulations of isolated disc galaxies with isothermal gas, and compare the
results with the prediction of our analytic model. Our model describes
accurately the evolution of the spiral arms in our simulations, even when
spiral arms dynamically interact with one another. We show that most of the
giant clumps formed in the simulated disc galaxies satisfy the instability
condition. The clump masses predicted by our model are in agreement with the
simulation results, but the growth time-scale of unstable perturbations is
overestimated by a factor of a few. We also apply our instability analysis to
derive scaling relations of clump properties. The expected scaling relation
between the clump size, velocity dispersion, and circular velocity is slightly
different from that given by the Toomre instability analysis, but neither is
inconsistent with currently available observations. We argue that the
spiral-arm instability is a viable formation mechanism of giant clumps in
gas-rich disc galaxies.


  Human motions (especially dance motions) are very noisy, and it is hard to
analyze and edit the motions. To resolve this problem, we propose a new method
to decompose and modify the motions using the Hilbert-Huang transform (HHT).
First, HHT decomposes a chromatic signal into "monochromatic" signals that are
the so-called Intrinsic Mode Functions (IMFs) using an Empirical Mode
Decomposition (EMD) [6]. After applying the Hilbert Transform to each IMF, the
instantaneous frequencies of the "monochromatic" signals can be obtained. The
HHT has the advantage to analyze non-stationary and nonlinear signals such as
human-joint-motions over FFT or Wavelet transform.
  In the present paper, we propose a new framework to analyze and extract some
new features from a famous Japanese threesome pop singer group called
"Perfume", and compare it with Waltz and Salsa dance. Using the EMD, their
dance motions can be decomposed into motion (choreographic) primitives or IMFs.
Therefore we can scale, combine, subtract, exchange, and modify those IMFs, and
can blend them into new dance motions self-consistently. Our analysis and
framework can lead to a motion editing and blending method to create a new
dance motion from different dance motions.


  We calculate a $\mathrm{G}_2$-period of a Fourier coefficient of a cuspidal
Eisenstein series on the split simply-connected group $\mathrm{E}_6$, and
relate this period to the Ginzburg-Rallis period of cusp forms on
$\mathrm{GL}_6$. This gives us a relation between the Ginzburg-Rallis period
and the central value of the exterior cube L-function of $\mathrm{GL}_6$


  Metasurface-based optical elements typically manipulate light waves by
imparting space-variant changes in the amplitude and phase with a dense array
of scattering nanostructures. The highly-localized and low
optical-quality-factor (Q) modes of nanostructures are beneficial for
wavefront-shaping as they afford quasi-local control over the electromagnetic
fields. However, many emerging imaging, sensing, communication, display, and
non-linear optics applications instead require flat, high-Q optical elements
that provide notable energy storage and a much higher degree of spectral
control over the wavefront. Here, we demonstrate high-Q, nonlocal metasurfaces
with atomically-thin metasurface elements that offer notably enhanced
light-matter interaction and fully-decoupled optical functions at different
wavelengths. We illustrate a possible use of such a flat optic in eye tracking
for eye-wear. Here, a metasurface patterned on a regular pair of eye-glasses
provides an unperturbed view of the world across the visible spectrum and
redirects near-infrared light to a camera to allow imaging of the eye.


  It is well known that some spacetime singularities of low energy effective
action can be resolved by the effective loop corrections. However, the known
potentials for the loop corrections fail to regulate the singularity of three
dimensional black string. An alternative method is to introduce an extra flat
spatial direction and boost away the singularity by using the
$O\left(d,d\right)$ rotation with the special Kalb-Ramond field. In this paper,
we investigate a new set of non-local dilaton potentials for the effective loop
corrections. The result shows that the singularity of three dimensional black
string can be consistently resolved by the loop corrections.


  We cast encryption via classical block ciphers in terms of operator spreading
in a dual space of Pauli strings, a formulation which allows us to characterize
classical ciphers by using tools well known in the analysis of quantum
many-body systems. We connect plaintext and ciphertext attacks to out-of-time
order correlators (OTOCs) and quantify the quality of ciphers using measures of
delocalization in string space such as participation ratios and corresponding
entropies obtained from the wave function amplitudes in string space. The
saturation of the string-space information entropy is accompanied by the
vanishing of OTOCs. Together these signal irreversibility and chaos, which we
take to be the defining properties of good classical ciphers. More precisely,
we define a good cipher by requiring that the OTOCs vanish to exponential
precision and that the string entropies saturate to the values associated with
a random permutation, which are computed explicitly in the paper. We argue that
these conditions can be satisfied by $n$-bit block ciphers implemented via
random reversible circuits with ${\cal O}(n \log n)$ gates arranged on a tree
structure, with layers of $n/3$ 3-bit gates, for which a "key" specifies
uniquely the sequence of gates that comprise the circuit. We show that in order
to reach this "speed limit" one must employ a three-stage circuit consisting of
a stage implemented by layers of nonlinear gates that proliferate the number of
strings, flanked by two other stages, each deploying layers of a special set of
linear "inflationary" gates that accelerate the growth of small individual
strings. A shallow, ${\cal O}(\log n)$-depth cipher of the type described here
can be used in constructing a polynomial-overhead scheme for computation on
encrypted data proposed in another publication as an alternative to Homomorphic
Encryption.


  The main stated contribution of the Deformable Parts Model (DPM) detector of
Felzenszwalb et al. (over the Histogram-of-Oriented-Gradients approach of Dalal
and Triggs) is the use of deformable parts. A secondary contribution is the
latent discriminative learning. Tertiary is the use of multiple components. A
common belief in the vision community (including ours, before this study) is
that their ordering of contributions reflects the performance of detector in
practice. However, what we have experimentally found is that the ordering of
importance might actually be the reverse. First, we show that by increasing the
number of components, and switching the initialization step from their
aspect-ratio, left-right flipping heuristics to appearance-based clustering,
considerable improvement in performance is obtained. But more intriguingly, we
show that with these new components, the part deformations can now be
completely switched off, yet obtaining results that are almost on par with the
original DPM detector. Finally, we also show initial results for using multiple
components on a different problem -- scene classification, suggesting that this
idea might have wider applications in addition to object detection.


  A theoretical treatment of deeply supercooled liquids is difficult because
their properties emerge from spatial inhomogeneities that are self-induced,
transient, and nanoscopic. I use computer simulations to analyse self-induced
static and dynamic heterogeneity in equilibrium systems approaching the
experimental glass transition. I characterise the broad sample-to-sample
fluctuations of salient dynamic and thermodynamic properties in elementary
mesoscopic systems. Findings regarding local lifetimes and distributions of
dynamic heterogeneity are in excellent agreement with recent single molecule
studies. Surprisingly broad thermodynamic fluctuations are also found, which
correlate well with dynamics fluctuations, thus providing a local test of the
thermodynamic origin of slow dynamics.


  Stable fold maps are fundamental tools in a generalization of the theory of
Morse functions on smooth manifolds
  and its application to studies of geometric properties of smooth manifolds.
Round fold maps were introduced as stable fold
  maps such that the sets of all of the singular values of them are concentric
spheres by the author
  in 2013-4. Topological properties of such maps and topological information of
their source manifolds such as homology
  and homotopy groups have been studied under appropriate conditions by the
author.
  In this paper, we redefine round fold maps respecting the definition. As more
precise information of manifolds admitting round fold maps, we study the
topologies and differentiable structures of manifolds admitting such maps under
appropriate differential topological conditions.


  We extend the quantum discord to continuous variable systems and evaluate
Gaussian quantum discord C(\rho) for bipartite Gaussian states. In particular,
for squeezed thermal states (STS), we explicitly maximize the extractable
information over Gaussian measurements: C(\rho) is minimized by a generalized
measurement rather than a projective one. Almost all STS have nonzero Gaussian
discord: they may be either separable or entangled if the discord is below the
threshold C(\rho)=1, whereas they are all entangled above the threshold. We
elucidate the general role of state parameters in determining the discord and
discuss its evolution in noisy channels.


  In the VKS2 (von K\'arm\'an Sodium 2) successful dynamo experiment of
September 2006, the magnetic field that was observed showed a strong
axisymmetric component, implying that non axisymmetric components of the flow
field were acting. By modeling the induction effect of the spiraling flow
between the blades of the impellers in a kinematic dynamo code, we find that
the axisymmetric magnetic mode is excited and becomes dominant in the vicinity
of the dynamo threshold. % The control parameters are the magnetic Reynolds
number of the mean flow, the coefficient measuring the induction effect,
$\alpha$, and the type of boundary conditions (vacuum for steel impellers and
normal field for soft iron impellers). We show that using realistic values of
$\alpha$, the observed critical magnetic Reynolds number, $Rm^c \approx 32$,
can be reached easily with ferromagnetic boundary conditions. We conjecture
that the dynamo action achieved in this experiment may not be related to the
turbulence in the bulk of the flow, but rather to the alpha effect induced by
the impellers.


  The quasielastic (e,e$^\prime$p) reaction was studied on targets of
deuterium, carbon, and iron up to a value of momentum transfer $Q^2$ of 8.1
(GeV/c)$^2$. A nuclear transparency was determined by comparing the data to
calculations in the Plane-Wave Impulse Approximation. The dependence of the
nuclear transparency on $Q^2$ and the mass number $A$ was investigated in a
search for the onset of the Color Transparency phenomenon. We find no evidence
for the onset of Color Transparency within our range of $Q^2$. A fit to the
world's nuclear transparency data reflects the energy dependence of the free
proton-nucleon cross section.


  We formulate and establish a generalization of Koll\'ar's injectivity theorem
for adjoint bundles twisted by suitable multiplier ideal sheaves. As
applications, we generalize Koll\'ar's torsion-freeness, Koll\'ar's vanishing
theorem, and a generic vanishing theorem for pseudo-effective line bundles. Our
approach is not Hodge theoretic but analytic, which enables us to treat
singular Hermitian metrics with nonalgebraic singularities. For the proof of
the main injectivity theorem, we use $L^{2}$-harmonic forms on noncompact
K\"ahler manifolds. For applications, we prove a Bertini-type theorem on the
restriction of multiplier ideal sheaves to general members of free linear
systems.


  Thermodynamics is one of the fascinating branches of traditional physics to
certify the occurrence of many natural processes. On the other hand, quantum
theory is the most acceptable description of the microscopic world. In the
present work, we have studied how the structure of quantum theory prohibits
cloning or masking of several thermodynamic quantities, viz., work and energy
stored in a quantum state. Our results have important consequences in quantum
partial cloning, quantum masking and on the action of quantum channels.


  A radial velocity follow-up of the long-period sdOB+G1V type spectroscopic
binary SB 744 revealed strong lines of fluorine and lead in the optical
spectrum of the sdOB star and subsolar metallicity in the G1V companion. With
high-quality observations and Gaia astrometric data, we aim at measuring the
chemical composition and Galactic kinematics of the system to put it in context
with known populations of hot subdwarfs. Such binary systems have high
potential, as they give insights into the late stages of binary evolution as
well as into the mysterious formation of stripped core helium-burning stars. We
have analyzed the optical spectra with homogeneous atmospheric models to derive
surface parameters of the binary members from a direct wavelength space
decomposition and independently measured the atmospheric properties of the cool
companion. The two independent methods reached consistent results, which,
amended with constraints from spectral energy distributions provided a subdwarf
mass. The Gaia astrometry allowed us to derive the Galactic kinematics of the
system. SB 744 turned out to be an old, Population II system, that has gone
through dramatic events. The hot subdwarf star belongs to the heavy-metal
subclass of sdOB stars and we report super-solar abundances of lead, based on
Pb III/IV lines. The He abundance of the hot subdwarf is the lowest among the
known heavy-metal sdOB stars. The presence of fluorine implies that SB 744 was
once a hierarchical triple system and the inner binary has merged in the near
past. As an alternative scenario, single-star evolution through late core
helium flash and atmospheric mixing can also produce the observed fluorine
abundances. The atmospheric metal over-abundances currently observed are
perhaps the results of a combination of mixing processes during formation and
radiative support.


  We investigate charge ordering in the presence of electron-phonon coupling
for quarter-filled ladder systems by using Exact Diagonalization. As an example
we consider NaV2O5 using model parameters obtained from first-principles
band-structure calculations. The relevant Holstein coupling to the lattice
considerably reduces the critical value of the nearest-neighbor Coulomb
repulsion at which formation of the zig-zag charge-ordered state occurs, which
is then accompanied by a static lattice distortion. Energy and length of a
kink-like excitation on the background of the distorted lattice are calculated.
Spin and charge spectra on ladders with and without static distortion are
obtained, and the charge gap and the effective spin-spin exchange parameter J
are extracted. J agrees well with experimental results. Analysis of the
dynamical Holstein model, restricted to a small number of phonons, shows that
low frequency lattice vibrations increase the charge order, accompanied by
dynamically produced zig-zag lattice distortions.


  The integration of renewable generation poses operational and economic
challenges for the electricity grid. For the core problem of power balance, the
legacy paradigm of tailoring supply to follow random demand may be
inappropriate under deep penetration of uncertain and intermittent renewable
generation. In this situation, there is an emerging consensus that the
alternative approach of controlling demand to follow random supply offers
compelling economic benefits in terms of reduced regulation costs. This
approach exploits the flexibility of demand side resources and requires
sensing, actuation, and communication infrastructure; distributed control
algorithms; and viable schemes to compensate participating loads. This paper
considers rate-constrained energy services which are a specific paradigm for
flexible demand. These services are characterized by a specified delivery
window, the total amount of energy that must be supplied over this window, and
the maximum rate at which this energy may be delivered. We consider a forward
market where rate-constrained energy services are traded. We explore allocation
policies and market decisions of a supplier in this market. The supplier owns a
generation mix that includes some uncertain renewable generation and may also
purchase energy in day-ahead and real-time markets to meet customer demand. The
supplier must optimally select the portfolio of rate-constrained services to
sell, the amount of day-ahead energy to buy, and the policies for making
real-time energy purchases and allocations to customers to maximize its
expected profit. We offer solutions to the supplier's decision and control
problems to economically provide rate constrained energy services.


  The Epstein--Glaser type T-subtraction introduced by one of the authors in a
previous paper is extended to the Lorentz invariant framework. The advantage of
using our subtraction instead of Epstein and Glaser's standard W-subtraction
method is especially important when working in Minkowski space, as then the
counterterms necessary to keep Lorentz invariance are simplified. We show how
T-renormalization of primitive diagrams in the Lorentz invariant framework
directly relates to causal Riesz distributions. A covariant subtraction rule in
momentum space is found, sharply improving upon the BPHZL method for massless
theories.


  Using a chiral unitary approach for meson-baryon scattering in the
strangeness zero sector, where the $N^*(1535)$ resonance is dynamically
generated, we study the reactions $\gamma p \to \pi^0 \eta p$ and $\gamma p \to
\pi^0 K^0 \Sigma^+$ at photon energies at which the final states are produced
close to threshold. Among several reaction mechanisms, we find the most
important is the excitation of the $\Delta^*(1700)$ state which subsequently
decays into a pseudoscalar meson and a baryon belonging to the $\Delta(1232)$
decuplet. Hence, the reaction provides useful information with which to test
current theories of the dynamical generation of the low-lying $3/2^-$ states.
The first reaction is shown to lead to sizable cross sections and the
$N^*(1535)$ resonance shape is seen clearly in the $\eta p$ invariant mass
distribution. The same dynamical model is shown to lead to much smaller cross
sections at low energies in the second reaction. Predictions are made for cross
sections and invariant mass distributions which can be compared with
forthcoming experiments at ELSA.


  We present a general deconstruction procedure aimed at recognizing whether a
given conformal model may be obtained as an orbifold of another one, and to
identify the twist group and the original model in terms of some readily
available characteristics. The ideas involved are illustrated on the maximal
deconstruction of the Ashkin-Teller model $\mathtt{AT}_{16}$.


  We investigate the cosmological and the local tests of the f(R) theory of
modified gravity via the observations of (1) the cosmic expansion and (2) the
cosmic structures and via (3) the solar-system experiments. To fit the possible
cosmic expansion histories under consideration, for each of them we reconstruct
f(R), known as "designer f(R)". We then test the designer f(R) via the
cosmic-structure constraints on the metric perturbation ratio Psi/Phi and the
effective gravitational coupling G_eff and via the solar-system constraints on
the Brans-Dicke theory with the chameleon mechanism. We find that among the
designer f(R) models specified by the CPL effective equation of state w_eff,
only the model closely mimicking general relativity with a cosmological
constant (LambdaCDM) can survive all the tests. Accordingly, these tests rule
out the frequently studied "w_eff = -1" designer f(R) models which are distinct
in cosmic structures from LambdaCDM. When considering only the cosmological
tests, we find that the surviving designer f(R) models, although exist for a
variety of w_eff, entail fine-tuning.


  The dynamical evolution of planetary systems leaves observable signatures in
debris disks. Optical images trace micron-sized grains, which are strongly
affected by stellar radiation and need not coincide with their parent body
population. Observations of mm-size grains accurately trace parent bodies, but
previous images lack the resolution and sensitivity needed to characterize the
ring's morphology. Here we present ALMA 350 GHz observations of the Fomalhaut
debris ring. These observations demonstrate that the parent body population is
13-19 AU wide with a sharp inner and outer boundary. We discuss three possible
origins for the ring, and suggest that debris confined by shepherd planets is
the most consistent with the ring's morphology.


  Stabilization is a key dependability property for dealing with unanticipated
transient faults, as it guarantees that even in the presence of such faults,
the system will recover to states where it satisfies its specification. One of
the desirable attributes of stabilization is the use of bounded space for each
variable. In this paper, we present an algorithm that transforms a stabilizing
program that uses variables with unbounded domain into a stabilizing program
that uses bounded variables and (practically bounded) physical time. While
non-stabilizing programs (that do not handle transient faults) can deal with
unbounded variables by assigning large enough but bounded space, stabilizing
programs that need to deal with arbitrary transient faults cannot do the same
since a transient fault may corrupt the variable to its maximum value. We show
that our transformation algorithm is applicable to several problems including
logical clocks, vector clocks, mutual exclusion, leader election, diffusing
computations, Paxos based consensus, and so on. Moreover, our approach can also
be used to bound counters used in an earlier work by Katz and Perry for adding
stabilization to a non-stabilizing program. By combining our algorithm with
that earlier work by Katz and Perry, it would be possible to provide
stabilization for a rich class of problems, by assigning large enough but
bounded space for variables.


  The current and next observation seasons will detect hundreds of
gravitational waves (GWs) from compact binary systems coalescence at
cosmological distances. When combined with independent electromagnetic
measurements, the source redshift will be known, and we will be able to obtain
precise measurements of the Hubble constant $H_0$ via the distance-redshift
relation. However, most observed mergers are not expected to have
electromagnetic counterparts, which prevents a direct redshift measurement. In
this scenario, one of the possibilities is to use the dark sirens method that
statistically marginalizes over all the potential host galaxies within the GW
location volume to provide a probabilistic redshift to the source. Here we
presented $H_{0}$ measurements using two new dark sirens compared to previous
analyses using DECam data, GW190924$\_$021846 and GW200202$\_$154313. The
photometric redshifts of the possible host galaxies of these two events are
acquired from the DECam Local Volume Exploration Survey (DELVE) carried out on
the Blanco telescope at Cerro Tololo in Chile. The combination of the $H_0$
posterior from GW190924$\_$021846 and GW200202$\_$154313 together with the
bright siren GW170817 leads to $H_{0} = 68.84^{+15.51}_{-7.74}\,
\rm{km/s/Mpc}$. Including these two dark sirens improves the 68% confidence
interval (CI) by 7% over GW170817 alone. This demonstrates that the inclusion
of well-localized dark sirens in such analysis improves the precision with
which cosmological measurements can be made. Using a sample containing 10
well-localized dark sirens observed during the third LIGO/Virgo observation
run, we determine a measurement of $H_{0} = 76.00^{+17.64}_{-13.45}\, \rm{km
/s/Mpc}$.


  Millimeter wave (mmWave) and massive MIMO systems are intrinsic components of
5G and beyond. These systems rely on using beamforming codebooks for both
initial access and data transmission. Current beam codebooks, however,
generally consist of a large number of narrow beams that scan all possible
directions, even if these directions are never used. This leads to very large
training overhead. Further, these codebooks do not normally account for the
hardware impairments or the possible non-uniform array geometries, and their
calibration is an expensive process. To overcome these limitations, this paper
develops an efficient online machine learning framework that learns how to
adapt the codebook beam patterns to the specific deployment, surrounding
environment, user distribution, and hardware characteristics. This is done by
designing a novel complex-valued neural network architecture in which the
neuron weights directly model the beamforming weights of the analog phase
shifters, accounting for the key hardware constraints such as the
constant-modulus and quantized-angles. This model learns the codebook beams
through online and self-supervised training avoiding the need for explicit
channel state information. This respects the practical situations where the
channel is either unavailable, imperfect, or hard to obtain, especially in the
presence of hardware impairments. Simulation results highlight the capability
of the proposed solution in learning environment and hardware aware beam
codebooks, which can significantly reduce the training overhead, enhance the
achievable data rates, and improve the robustness against possible hardware
impairments.


  Under Martin's Axiom we construct a Boolean countably compact topological
group whose square is not countably pracompact.


  The transport of spin information has been studied in various materials, such
as metals, semiconductors and graphene. In these materials, spin is transported
by diffusion of conduction electrons. Here we study the diffusion and
relaxation of spin in a magnetic insulator, where the large bandgap prohibits
the motion of electrons. Spin can still be transported, however, through the
diffusion of non-equilibrium magnons, the quanta of spin wave excitations in
magnetically ordered materials. Here we show experimentally that these magnons
can be excited and detected fully electrically in linear response, and can
transport spin angular momentum through the magnetic insulator yttrium iron
garnet (YIG) over distances as large as 40 micrometer. We identify two
transport regimes: the diffusion limited regime for distances shorter than the
magnon relaxation length, and the relaxation limited regime for larger
distances. With a model similar to the diffusion-relaxation model for electron
spin transport in (semi)conducting materials, we extract the magnon relaxation
length lambda = 9.4 micrometer in a 200 nm thin YIG film at room temperature.


  Using the pair-count implementaion from the Corrfunc package we show that
with a low discrepency sequence we can calculate the two-point correlation
function more accurately than with random points at no extra computational
cost.


  We explicitly evaluate the heat kernel for the Laplacian of arbitrary spin
tensor fields on the thermal quotient of (Euclidean) $AdS_N$ for $N\geq 3$
using the group theoretic techniques employed for $AdS_3$ in arXiv:0911.5085.
Our approach is general and can be used, in principle, for other quotients as
well as other symmetric spaces.


  We study the Riemannian optimization methods on the embedded manifold of low
rank matrices for the problem of matrix completion, which is about recovering a
low rank matrix from its partial entries. Assume $m$ entries of an $n\times n$
rank $r$ matrix are sampled independently and uniformly with replacement. We
first prove that with high probability the Riemannian gradient descent and
conjugate gradient descent algorithms initialized by one step hard thresholding
are guaranteed to converge linearly to the measured matrix provided
\begin{align*} m\geq C_\kappa n^{1.5}r\log^{1.5}(n), \end{align*} where
$C_\kappa$ is a numerical constant depending on the condition number of the
underlying matrix. The sampling complexity has been further improved to
\begin{align*} m\geq C_\kappa nr^2\log^{2}(n) \end{align*} via the resampled
Riemannian gradient descent initialization. The analysis of the new
initialization procedure relies on an asymmetric restricted isometry property
of the sampling operator and the curvature of the low rank matrix manifold.
Numerical simulation shows that the algorithms are able to recover a low rank
matrix from nearly the minimum number of measurements.


  We have studied the time evolution of the electron spin polarization under
continuous photoexcitation in remotely n-doped semiconductor quantum wells. The
doped region allows us to get the necessary excess of free electrons to form
trions. We have considered electron resonant photoexcitation at free, exciton
and trion electron energy levels. Also, we have studied the relative effect of
photoexcitation energy density and doping concentration. In order to obtain the
two-dimensional density evolution of the different species, we have performed
dynamic calculations through the matrix density formalism. Our results indicate
that photoexcitation of free electron level leads to a higher spin
polarization. Also, we have found that increasing the photoexcitation energy or
diminishing the doping enhances spin polarization.


  This paper proposes and studies new quantum version of $f$-divergences, a
class of convex functionals of a pair of probability distributions including
Kullback-Leibler divergence, Rnyi-type relative entropy and so on. There are
several quantum versions so far, including the one by Petz. We introduce
another quantum version ($\mathrm{D}_{f}^{\max}$, below), defined as the
solution to an optimization problem, or the minimum classical $f$- divergence
necessary to generate a given pair of quantum states. It turns out to be the
largest quantum $f$-divergence. The closed formula of $\mathrm{D}_{f}^{\max}$
is given either if $f$ is operator convex, or if one of the state is a pure
state. Also, concise representation of $\mathrm{D}_{f}^{\max}$ as a pointwise
supremum of linear functionals is given and used for the clarification of
various properties of the quality.
  Using the closed formula of $\mathrm{D}_{f}^{\max}$, we show: Suppose $f$ is
operator convex. Then the\ maximum $f\,$- divergence of the probability
distributions of a measurement under the state $\rho$ and $\sigma$ is strictly
less than $\mathrm{D}_{f}^{\max}\left( \rho\Vert\sigma\right) $. This statement
may seem intuitively trivial, but when $f$ is not operator convex, this is not
always true. A counter example is $f\left( \lambda\right) =\left\vert
1-\lambda\right\vert $, which corresponds to total variation distance.
  We mostly work on finite dimensional Hilbert space, but some results are
extended to infinite dimensional case.


  We investigate magnetic monopole solutions of the non-abelian DBI action
describing 2 coincident non-BPS D9-branes in flat space. Just as in the case of
kink and vortex solitonic tachyon solutions of the full DBI non-BPS actions, as
previously analyzed by Sen, these monopole configurations are singular in the
first instance and require regularization. We discuss a suitable non-abelian
ansatz and show it solves the equations of motion to leading order in the
regularization parameter. Fluctuations are studied and shown to describe a
codimension 3 BPS D6-brane. A formula is derived for its tension. We comment on
the implication to our results from both the trace (Tr) and symmetrized trace
(Str) prescriptions of the non-abelian DBI action of coincident non-BPS
D9-branes.


  The EnVision and VERITAS missions to Venus will fly with X and Ka band
telecommunications channels which can be used to conduct radio occultation
studies of Venus' atmosphere. While link attenuation measurements during prior
S and X band occultation experiments have been used to determine vertical
profiles of H$_2$SO$_4$ vapor abundance, the addition of the Ka band channel
introduces greater sensitivity to the abundances of H$_2$SO$_4$ aerosols and
SO$_2$ gas, permitting retrieval of their vertical profiles from dual band
measurements. Such measurements would be valuable in the assessment of chemical
and dynamical processes governing short and long-term variability in Venus'
atmosphere. This paper considers the sensitivity of the X/Ka band radio
attenuation measurement to these atmospheric constituents, as well as
uncertainties and regularization approaches for conducting retrievals of these
atmospheric sulfur species from future occultation experiments. We introduce
methods for seeding maximum likelihood estimation retrievals using shape models
and simple atmospheric transport constraints. From simulated retrievals, we
obtain mean errors of the order of 0.5 ppm, 20 ppm, and 10 mg/m$^3$ for
H$_2$SO$_4$ vapor, SO$_2$, and H$_2$SO$_4$ aerosol abundances, respectively,
for simultaneous retrieval.


  Anyons are two dimensional particles with fractional exchange statistics that
emerge as elementary excitations of fractional quantum Hall phases.
Experimentally, anyonic statistics manifest directly in the edge-state
Fabry-P\'erot interferometer geometry, where the presence of $N_{qp}$ localized
anyons in the interferometer bulk contributes a phase $N_{qp} \theta_a$ to the
observed interference pattern, where $\theta_a$ is twice the statistical
exchange phase. Here, we report a measurement of $\theta_a$ in a monolayer
graphene Fabry-P\'erot interferometer at $\nu$ = 1/3. We find a preponderance
of phase slips with magnitudes $\Delta \theta \approx 2 \pi / 3$, confirming
the result of past experiments in GaAs quantum wells and consistent with
expectations for the tunneling of Abelian anyons into the interferometer bulk.
In contrast to prior work, however, single anyon tunneling events manifest as
instantaneous and irreversible phase slips, indicative of quasiparticle
equilibration times exceeding 20 minutes in some cases. We use the discrepancy
between the quasiparticle equilibration rate and our measurement speed to vary
the interferometer area and $N_{qp}$ independently, allowing us to precisely
determine the interferometer phase and monitor the entry and exit of individual
anyons to the interferometer loop in the time domain. Besides providing a
replication of previous interferometric measurements sensitive to $\theta_a$ in
GaAs, our results bring anyon dynamics into the experimental regime and suggest
that the average `topological charge' of a mesoscopic quantum Hall device can
be held constant over hour long timescales.


  We present the mass distribution at the core of SDSS J1531+3414, a
strong-lensing cluster at z=0.335. We find that the mass distribution is well
described by two cluster-scale halos with a contribution from cluster-member
galaxies. New HST observations of SDSS J1531+3414 reveal a signature of ongoing
star formation associated with the two central galaxies at the core of the
cluster, in the form of a chain of star forming regions at the center of the
cluster. Using the lens model presented here, we place upper limits on the
contribution of a possible lensed image to the flux at the center region, and
rule out that this emission is coming from a background source.


  We demonstrate spin-accumulation signals controlled by the gate voltage in a
metal-oxide-semiconductor field effect transistor structure with a Si channel
and a CoFe/$n^{+}$-Si contact at room temperature. Under the application of a
back-gate voltage, we clearly observe the three-terminal Hanle-effect signal,
i.e., spin-accumulation signal. The magnitude of the spin-accumulation signals
can be reduced with increasing the gate voltage. We consider that the gate
controlled spin signals are attributed to the change in the carrier density in
the Si channel beneath the CoFe/$n^{+}$-Si contact. This study is not only a
technological jump for Si-based spintronic applications with gate structures
but also reliable evidence for the spin injection into the semiconducting Si
channel at room temperature.


  Distributional identities for a L\'evy process $X_t$, its quadratic variation
process $V_t$ and its maximal jump processes, are derived, and used to make
"small time" (as $t\downarrow0$) asymptotic comparisons between them. The
representations are constructed using properties of the underlying Poisson
point process of the jumps of $X$. Apart from providing insight into the
connections between $X$, $V$, and their maximal jump processes, they enable
investigation of a great variety of limiting behaviours. As an application, we
study "self-normalised" versions of $X_t$, that is, $X_t$ after division by
$\sup_{0<s\le t}\Delta X_s$, or by $\sup_{0<s\le t}| \Delta X_s|$. Thus, we
obtain necessary and sufficient conditions for $X_t/\sup_{0<s\le t}\Delta X_s$
and $X_t/\sup_{0<s\le t}| \Delta X_s|$ to converge in probability to 1, or to
$\infty$, as $t\downarrow0$, so that $X$ is either comparable to, or dominates,
its largest jump. The former situation tends to occur when the singularity at 0
of the L\'evy measure of $X$ is fairly mild (its tail is slowly varying at 0),
while the latter situation is related to the relative stability or attraction
to normality of $X$ at 0 (a steeper singularity at 0). An important component
in the analyses is the way the largest positive and negative jumps interact
with each other. Analogous "large time" (as $t\to \infty$) versions of the
results can also be obtained.


  In this article, we present numerical enhancements of a multiscale domain
decomposition strategy based on a LaTIn solver and dedicated to the computation
of the debounding in laminates. We show that the classical scale separation is
irrelevant in the process zones, which results in a drop in the convergence
rate of the strategy. The scalability is restored by performing nonlinear
subresolutions in the vincinity of the front of the crack, at each prediction
stage of the iterative solver.


  We construct a class of closed timelike curves (CTCs) using a compactified
extra dimension $u$. A nonzero metric element $g_{tu}(u)$ enables particles to
travel backwards in global time $t$. The compactified dimension guarantees that
the geodesic curve closes in $u$. The effective 2D ($t$ and $u$) nature of the
metric ensures that spacetime is flat, therein satisfying all the classical
stability conditions as expressed by the energy conditions. Finally,
stationarity of the metric guarantees that a particle's energy is conserved.
The pathologies that plague many hypothesized metrics admitting CTCs, e.g. an
infinite cylinder of matter, a negative energy-distribution, particle
acceleration/blue-shifting along the CTC, do not occur within our metric class.


  Understanding the physics of nonequilibrium systems remains as one of the
major challenges of theoretical physics. This problem can be cracked in part by
investigating the macroscopic fluctuations of the currents characterizing
nonequilibrium behavior, their statistics and associated structures. This
fundamental line of research has been severely hampered by the overwhelming
complexity of this problem. However, during the last years two new general
methods have appeared to investigate fluctuating behavior that are changing
radically our understanding of nonequilibrium physics: a powerful macroscopic
fluctuation theory (MFT) and a set of advanced computational techniques to
measure rare events. In this work we study the statistics of current
fluctuations in nonequilibrium diffusive systems, using macroscopic fluctuation
theory as theoretical framework, and advanced Monte Carlo simulations of
several stochastic lattice gases as a laboratory to test the emerging picture.
Our quest will bring us from (1) the confirmation of an additivity conjecture
in one and two dimensions, which considerably simplifies the MFT complex
variational problem to compute the thermodynamics of currents, to (2) the
discovery of novel isometric fluctuation relations, which opens an unexplored
route toward a deeper understanding of nonequilibrium physics by bringing
symmetry principles to the realm of fluctuations, and to (3) the observation of
coherent structures in fluctuations, which appear via dynamic phase transitions
involving a spontaneous symmetry breaking event at the fluctuating level. The
clear-cut observation, measurement and characterization of these unexpected
phenomena, well described by MFT, strongly support this theoretical scheme as
the natural theory to understand the thermodynamics of currents in
nonequilibrium diffusive media, opening new avenues of research in
nonequilibrium physics.


  Let K be the closure of a bounded open set with smooth boundary in C^n. A
Fekete configuration of order p for K is a finite subset of K maximizing the
Vandermonde determinant associated with polynomials of degree at most p. A
recent theorem by Berman, Boucksom and Witt Nystrom implies that Fekete
configurations for K are asymptotically equidistributed with respect to a
canonical equilibrium measure, as p tends to infinite. We give here an explicit
estimate for the speed of convergence. The result also holds in a general
setting of Fekete points associated with an ample line bundle over a projective
manifold. Our approach requires a new estimate on Bergman kernels for line
bundles and quantitative results in pluripotential theory which are of
independent interest.


  With the widespread use of shared-nothing clusters of servers, there has been
a proliferation of distributed object stores that offer high availability,
reliability and enhanced performance for MapReduce-style workloads. However,
relational workloads cannot always be evaluated efficiently using MapReduce
without extensive data migrations, which cause network congestion and reduced
query throughput. We study the problem of computing data placement strategies
that minimize the data communication costs incurred by typical relational query
workloads in a distributed setting.
  Our main contribution is a reduction of the data placement problem to the
well-studied problem of {\sc Graph Partitioning}, which is NP-Hard but for
which efficient approximation algorithms exist. The novelty and significance of
this result lie in representing the communication cost exactly and using
standard graphs instead of hypergraphs, which were used in prior work on data
placement that optimized for different objectives (not communication cost).
  We study several practical extensions of the problem: with load balancing,
with replication, with materialized views, and with complex query plans
consisting of sequences of intermediate operations that may be computed on
different servers. We provide integer linear programs (IPs) that may be used
with any IP solver to find an optimal data placement. For the no-replication
case, we use publicly available graph partitioning libraries (e.g., METIS) to
efficiently compute nearly-optimal solutions. For the versions with
replication, we introduce two heuristics that utilize the {\sc Graph
Partitioning} solution of the no-replication case. Using the TPC-DS workload,
it may take an IP solver weeks to compute an optimal data placement, whereas
our reduction produces nearly-optimal solutions in seconds.