title: Exact Post-Selection Inference for Sequential Regression Procedures

abstract:
  We propose new inference tools for forward stepwise regression, least angle
regression, and the lasso. Assuming a Gaussian model for the observation vector
y, we first describe a general scheme to perform valid inference after any
selection event that can be characterized as y falling into a polyhedral set.
This framework allows us to derive conditional (post-selection) hypothesis
tests at any step of forward stepwise or least angle regression, or any step
along the lasso regularization path, because, as it turns out, selection events
for these procedures can be expressed as polyhedral constraints on y. The
p-values associated with these tests are exactly uniform under the null
distribution, in finite samples, yielding exact type I error control. The tests
can also be inverted to produce confidence intervals for appropriate underlying
regression parameters. The R package "selectiveInference", freely available on
the CRAN repository, implements the new inference tools described in this
paper.


title:
Analyzing Search Topology Without Running Any Search: On the Connection
  Between Causal Graphs and h+

abstract:
  The ignoring delete lists relaxation is of paramount importance for both
satisficing and optimal planning. In earlier work, it was observed that the
optimal relaxation heuristic h+ has amazing qualities in many classical
planning benchmarks, in particular pertaining to the complete absence of local
minima. The proofs of this are hand-made, raising the question whether such
proofs can be lead automatically by domain analysis techniques. In contrast to
earlier disappointing results -- the analysis method has exponential runtime
and succeeds only in two extremely simple benchmark domains -- we herein answer
this question in the affirmative. We establish connections between causal graph
structure and h+ topology. This results in low-order polynomial time analysis
methods, implemented in a tool we call TorchLight. Of the 12 domains where the
absence of local minima has been proved, TorchLight gives strong success
guarantees in 8 domains. Empirically, its analysis exhibits strong performance
in a further 2 of these domains, plus in 4 more domains where local minima may
exist but are rare. In this way, TorchLight can distinguish easy domains from
hard ones. By summarizing structural reasons for analysis failure, TorchLight
also provides diagnostic output indicating domain aspects that may cause local
minima.


title:
Multilevel Monte Carlo for the Feynman-Kac Formula for the Laplace
  Equation

abstract:
  Since its formulation in the late 1940s, the Feynman-Kac formula has proven
to be an effective tool for both theoretical reformulations and practical
simulations of differential equations. The link it establishes between such
equations and stochastic processes can be exploited to develop Monte Carlo
sampling methods that are effective, especially in high dimensions. There exist
many techniques of improving standard Monte Carlo sampling methods, a
relatively new development being the so-called Multilevel Monte Carlo method.
This paper investigates the applicability of multilevel ideas to the stochastic
representation of partial differential equations by the Feynman- Kac formula,
using the Walk on Sphere algorithm to generate the required random paths. We
focus on the Laplace equation, the simplest elliptic PDE, while mentioning some
extension possibilities.


title: Sequential Diagnosis by Abstraction

abstract:
  When a system behaves abnormally, sequential diagnosis takes a sequence of
measurements of the system until the faults causing the abnormality are
identified, and the goal is to reduce the diagnostic cost, defined here as the
number of measurements. To propose measurement points, previous work employs a
heuristic based on reducing the entropy over a computed set of diagnoses. This
approach generally has good performance in terms of diagnostic cost, but can
fail to diagnose large systems when the set of diagnoses is too large. Focusing
on a smaller set of probable diagnoses scales the approach but generally leads
to increased average diagnostic costs. In this paper, we propose a new
diagnostic framework employing four new techniques, which scales to much larger
systems with good performance in terms of diagnostic cost. First, we propose a
new heuristic for measurement point selection that can be computed efficiently,
without requiring the set of diagnoses, once the system is modeled as a
Bayesian network and compiled into a logical form known as d-DNNF. Second, we
extend hierarchical diagnosis, a technique based on system abstraction from our
previous work, to handle probabilities so that it can be applied to sequential
diagnosis to allow larger systems to be diagnosed. Third, for the largest
systems where even hierarchical diagnosis fails, we propose a novel method that
converts the system into one that has a smaller abstraction and whose diagnoses
form a superset of those of the original system; the new system can then be
diagnosed and the result mapped back to the original system. Finally, we
propose a novel cost estimation function which can be used to choose an
abstraction of the system that is more likely to provide optimal average cost.
Experiments with ISCAS-85 benchmark circuits indicate that our approach scales
to all circuits in the suite except one that has a flat structure not
susceptible to useful abstraction.


title: Most Relevant Explanation in Bayesian Networks

abstract:
  A major inference task in Bayesian networks is explaining why some variables
are observed in their particular states using a set of target variables.
Existing methods for solving this problem often generate explanations that are
either too simple (underspecified) or too complex (overspecified). In this
paper, we introduce a method called Most Relevant Explanation (MRE) which finds
a partial instantiation of the target variables that maximizes the generalized
Bayes factor (GBF) as the best explanation for the given evidence. Our study
shows that GBF has several theoretical properties that enable MRE to
automatically identify the most relevant target variables in forming its
explanation. In particular, conditional Bayes factor (CBF), defined as the GBF
of a new explanation conditioned on an existing explanation, provides a soft
measure on the degree of relevance of the variables in the new explanation in
explaining the evidence given the existing explanation. As a result, MRE is
able to automatically prune less relevant variables from its explanation. We
also show that CBF is able to capture well the explaining-away phenomenon that
is often represented in Bayesian networks. Moreover, we define two dominance
relations between the candidate solutions and use the relations to generalize
MRE to find a set of top explanations that is both diverse and representative.
Case studies on several benchmark diagnostic Bayesian networks show that MRE is
often able to find explanatory hypotheses that are not only precise but also
concise.


title: Efficient Multi-Start Strategies for Local Search Algorithms

abstract:
  Local search algorithms applied to optimization problems often suffer from
getting trapped in a local optimum. The common solution for this deficiency is
to restart the algorithm when no progress is observed. Alternatively, one can
start multiple instances of a local search algorithm, and allocate
computational resources (in particular, processing time) to the instances
depending on their behavior. Hence, a multi-start strategy has to decide
(dynamically) when to allocate additional resources to a particular instance
and when to start new instances. In this paper we propose multi-start
strategies motivated by works on multi-armed bandit problems and Lipschitz
optimization with an unknown constant. The strategies continuously estimate the
potential performance of each algorithm instance by supposing a convergence
rate of the local search algorithm up to an unknown constant, and in every
phase allocate resources to those instances that could converge to the optimum
for a particular range of the constant. Asymptotic bounds are given on the
performance of the strategies. In particular, we prove that at most a quadratic
increase in the number of times the target function is evaluated is needed to
achieve the performance of a local search algorithm started from the attraction
region of the optimum. Experiments are provided using SPSA (Simultaneous
Perturbation Stochastic Approximation) and k-means as local search algorithms,
and the results indicate that the proposed strategies work well in practice,
and, in all cases studied, need only logarithmically more evaluations of the
target function as opposed to the theoretically suggested quadratic increase.


title: On the Intertranslatability of Argumentation Semantics

abstract:
  Translations between different nonmonotonic formalisms always have been an
important topic in the field, in particular to understand the
knowledge-representation capabilities those formalisms offer. We provide such
an investigation in terms of different semantics proposed for abstract
argumentation frameworks, a nonmonotonic yet simple formalism which received
increasing interest within the last decade. Although the properties of these
different semantics are nowadays well understood, there are no explicit results
about intertranslatability. We provide such translations wrt. different
properties and also give a few novel complexity results which underlie some
negative results.


title:
The Opposite of Smoothing: A Language Model Approach to Ranking
  Query-Specific Document Clusters

abstract:
  Exploiting information induced from (query-specific) clustering of
top-retrieved documents has long been proposed as a means for improving
precision at the very top ranks of the returned results. We present a novel
language model approach to ranking query-specific clusters by the presumed
percentage of relevant documents that they contain. While most previous cluster
ranking approaches focus on the cluster as a whole, our model utilizes also
information induced from documents associated with the cluster. Our model
substantially outperforms previous approaches for identifying clusters
containing a high relevant-document percentage. Furthermore, using the model to
produce document ranking yields precision-at-top-ranks performance that is
consistently better than that of the initial ranking upon which clustering is
performed. The performance also favorably compares with that of a
state-of-the-art pseudo-feedback-based retrieval method.


title: Interpolable Formulas in Equilibrium Logic and Answer Set Programming

abstract:
  Interpolation is an important property of classical and many non-classical
logics that has been shown to have interesting applications in computer science
and AI. Here we study the Interpolation Property for the the non-monotonic
system of equilibrium logic, establishing weaker or stronger forms of
interpolation depending on the precise interpretation of the inference
relation. These results also yield a form of interpolation for ground logic
programs under the answer sets semantics. For disjunctive logic programs we
also study the property of uniform interpolation that is closely related to the
concept of variable forgetting. The first-order version of equilibrium logic
has analogous Interpolation properties whenever the collection of equilibrium
models is (first-order) definable. Since this is the case for so-called safe
programs and theories, it applies to the usual situations that arise in
practical answer set programming.


title: First-Order Stable Model Semantics and First-Order Loop Formulas

abstract:
  Lin and Zhaos theorem on loop formulas states that in the propositional case
the stable model semantics of a logic program can be completely characterized
by propositional loop formulas, but this result does not fully carry over to
the first-order case. We investigate the precise relationship between the
first-order stable model semantics and first-order loop formulas, and study
conditions under which the former can be represented by the latter. In order to
facilitate the comparison, we extend the definition of a first-order loop
formula which was limited to a nondisjunctive program, to a disjunctive program
and to an arbitrary first-order theory. Based on the studied relationship we
extend the syntax of a logic program with explicit quantifiers, which allows us
to do reasoning involving non-Herbrand stable models using first-order
reasoners. Such programs can be viewed as a special class of first-order
theories under the stable model semantics, which yields more succinct loop
formulas than the general language due to their restricted syntax.


title:
Representing and Reasoning with Qualitative Preferences for
  Compositional Systems

abstract:
  Many applications, e.g., Web service composition, complex system design, team
formation, etc., rely on methods for identifying collections of objects or
entities satisfying some functional requirement. Among the collections that
satisfy the functional requirement, it is often necessary to identify one or
more collections that are optimal with respect to user preferences over a set
of attributes that describe the non-functional properties of the collection.
  We develop a formalism that lets users express the relative importance among
attributes and qualitative preferences over the valuations of each attribute.
We define a dominance relation that allows us to compare collections of objects
in terms of preferences over attributes of the objects that make up the
collection. We establish some key properties of the dominance relation. In
particular, we show that the dominance relation is a strict partial order when
the intra-attribute preference relations are strict partial orders and the
relative importance preference relation is an interval order.
  We provide algorithms that use this dominance relation to identify the set of
most preferred collections. We show that under certain conditions, the
algorithms are guaranteed to return only (sound), all (complete), or at least
one (weakly complete) of the most preferred collections. We present results of
simulation experiments comparing the proposed algorithms with respect to (a)
the quality of solutions (number of most preferred solutions) produced by the
algorithms, and (b) their performance and efficiency. We also explore some
interesting conjectures suggested by the results of our experiments that relate
the properties of the user preferences, the dominance relation, and the
algorithms.


title: Decidability and Undecidability Results for Propositional Schemata

abstract:
  We define a logic of propositional formula schemata adding to the syntax of
propositional logic indexed propositions and iterated connectives ranging over
intervals parameterized by arithmetic variables. The satisfiability problem is
shown to be undecidable for this new logic, but we introduce a very general
class of schemata, called bound-linear, for which this problem becomes
decidable. This result is obtained by reduction to a particular class of
schemata called regular, for which we provide a sound and complete terminating
proof procedure. This schemata calculus allows one to capture proof patterns
corresponding to a large class of problems specified in propositional logic. We
also show that the satisfiability problem becomes again undecidable for slight
extensions of this class, thus demonstrating that bound-linear schemata
represent a good compromise between expressivity and decidability.


title: Defeasible Inclusions in Low-Complexity DLs

abstract:
  Some of the applications of OWL and RDF (e.g. biomedical knowledge
representation and semantic policy formulation) call for extensions of these
languages with nonmonotonic constructs such as inheritance with overriding.
Nonmonotonic description logics have been studied for many years, however no
practical such knowledge representation languages exist, due to a combination
of semantic difficulties and high computational complexity. Independently,
low-complexity description logics such as DL-lite and EL have been introduced
and incorporated in the OWL standard. Therefore, it is interesting to see
whether the syntactic restrictions characterizing DL-lite and EL bring
computational benefits to their nonmonotonic versions, too. In this paper we
extensively investigate the computational complexity of Circumscription when
knowledge bases are formulated in DL-lite_R, EL, and fragments thereof. We
identify fragments whose complexity ranges from P to the second level of the
polynomial hierarchy, as well as fragments whose complexity raises to PSPACE
and beyond.


title:
On the Link between Partial Meet, Kernel, and Infra Contraction and its
  Application to Horn Logic

abstract:
  Standard belief change assumes an underlying logic containing full classical
propositional logic. However, there are good reasons for considering belief
change in less expressive logics as well. In this paper we build on recent
investigations by Delgrande on contraction for Horn logic. We show that the
standard basic form of contraction, partial meet, is too strong in the Horn
case. This result stands in contrast to Delgrande's conjecture that orderly
maxichoice is the appropriate form of contraction for Horn logic. We then
define a more appropriate notion of basic contraction for the Horn case,
influenced by the convexity property holding for full propositional logic and
which we refer to as infra contraction. The main contribution of this work is a
result which shows that the construction method for Horn contraction for belief
sets based on our infra remainder sets corresponds exactly to Hansson's
classical kernel contraction for belief sets, when restricted to Horn logic.
This result is obtained via a detour through contraction for belief bases. We
prove that kernel contraction for belief bases produces precisely the same
results as the belief base version of infra contraction. The use of belief
bases to obtain this result provides evidence for the conjecture that Horn
belief change is best viewed as a hybrid version of belief set change and
belief base change. One of the consequences of the link with base contraction
is the provision of a representation result for Horn contraction for belief
sets in which a version of the Core-retainment postulate features.


title: Multi-Robot Adversarial Patrolling: Facing a Full-Knowledge Opponent

abstract:
  The problem of adversarial multi-robot patrol has gained interest in recent
years, mainly due to its immediate relevance to various security applications.
In this problem, robots are required to repeatedly visit a target area in a way
that maximizes their chances of detecting an adversary trying to penetrate
through the patrol path. When facing a strong adversary that knows the patrol
strategy of the robots, if the robots use a deterministic patrol algorithm,
then in many cases it is easy for the adversary to penetrate undetected (in
fact, in some of those cases the adversary can guarantee penetration).
Therefore this paper presents a non-deterministic patrol framework for the
robots. Assuming that the strong adversary will take advantage of its knowledge
and try to penetrate through the patrols weakest spot, hence an optimal
algorithm is one that maximizes the chances of detection in that point. We
therefore present a polynomial-time algorithm for determining an optimal patrol
under the Markovian strategy assumption for the robots, such that the
probability of detecting the adversary in the patrols weakest spot is
maximized. We build upon this framework and describe an optimal patrol strategy
for several robotic models based on their movement abilities (directed or
undirected) and sensing abilities (perfect or imperfect), and in different
environment models - either patrol around a perimeter (closed polygon) or an
open fence (open polyline).


title: Norm Estimates for Solutions of Elliptic BVPs of the Dirac Operator

abstract:
  We present norm estimates for solutions of first and second order elliptic
BVPs of the Dirac operator considered over a bounded and smooth domain of the
n-dimension Euclidean space. The solutions whose norms to be estimated are in
some Sobolev spaces and the boundary conditions as traces of solutions and
their derivatives are in some Slobodeckji spaces.


title:
MAPP: a Scalable Multi-Agent Path Planning Algorithm with Tractability
  and Completeness Guarantees

abstract:
  Multi-agent path planning is a challenging problem with numerous real-life
applications. Running a centralized search such as A* in the combined state
space of all units is complete and cost-optimal, but scales poorly, as the
state space size is exponential in the number of mobile units. Traditional
decentralized approaches, such as FAR and WHCA*, are faster and more scalable,
being based on problem decomposition. However, such methods are incomplete and
provide no guarantees with respect to the running time or the solution quality.
They are not necessarily able to tell in a reasonable time whether they would
succeed in finding a solution to a given instance. We introduce MAPP, a
tractable algorithm for multi-agent path planning on undirected graphs. We
present a basic version and several extensions. They have low-polynomial
worst-case upper bounds for the running time, the memory requirements, and the
length of solutions. Even though all algorithmic versions are incomplete in the
general case, each provides formal guarantees on problems it can solve. For
each version, we discuss the algorithms completeness with respect to clearly
defined subclasses of instances. Experiments were run on realistic game grid
maps. MAPP solved 99.86% of all mobile units, which is 18--22% better than the
percentage of FAR and WHCA*. MAPP marked 98.82% of all units as provably
solvable during the first stage of plan computation. Parts of MAPPs computation
can be re-used across instances on the same map. Speed-wise, MAPP is
competitive or significantly faster than WHCA*, depending on whether MAPP
performs all computations from scratch. When data that MAPP can re-use are
preprocessed offline and readily available, MAPP is slower than the very fast
FAR algorithm by a factor of 2.18 on average. MAPPs solutions are on average
20% longer than FARs solutions and 7--31% longer than WHCA*s solutions.


title:
Making Decisions Using Sets of Probabilities: Updating, Time
  Consistency, and Calibration

abstract:
  We consider how an agent should update her beliefs when her beliefs are
represented by a set P of probability distributions, given that the agent makes
decisions using the minimax criterion, perhaps the best-studied and most
commonly-used criterion in the literature. We adopt a game-theoretic framework,
where the agent plays against a bookie, who chooses some distribution from P.
We consider two reasonable games that differ in what the bookie knows when he
makes his choice. Anomalies that have been observed before, like time
inconsistency, can be understood as arising because different games are being
played, against bookies with different information. We characterize the
important special cases in which the optimal decision rules according to the
minimax criterion amount to either conditioning or simply ignoring the
information. Finally, we consider the relationship between updating and
calibration when uncertainty is described by sets of probabilities. Our results
emphasize the key role of the rectangularity condition of Epstein and
Schneider.


title:
Policy Invariance under Reward Transformations for General-Sum
  Stochastic Games

abstract:
  We extend the potential-based shaping method from Markov decision processes
to multi-player general-sum stochastic games. We prove that the Nash equilibria
in a stochastic game remains unchanged after potential-based shaping is applied
to the environment. The property of policy invariance provides a possible way
of speeding convergence when learning to play a stochastic game.


title:
Centrality-as-Relevance: Support Sets and Similarity as Geometric
  Proximity

abstract:
  In automatic summarization, centrality-as-relevance means that the most
important content of an information source, or a collection of information
sources, corresponds to the most central passages, considering a representation
where such notion makes sense (graph, spatial, etc.). We assess the main
paradigms, and introduce a new centrality-based relevance model for automatic
summarization that relies on the use of support sets to better estimate the
relevant content. Geometric proximity is used to compute semantic relatedness.
Centrality (relevance) is determined by considering the whole input source (and
not only local information), and by taking into account the existence of minor
topics or lateral subjects in the information sources to be summarized. The
method consists in creating, for each passage of the input source, a support
set consisting only of the most semantically related passages. Then, the
determination of the most relevant content is achieved by selecting the
passages that occur in the largest number of support sets. This model produces
extractive summaries that are generic, and language- and domain-independent.
Thorough automatic evaluation shows that the method achieves state-of-the-art
performance, both in written text, and automatically transcribed speech
summarization, including when compared to considerably more complex approaches.


title: Scheduling Bipartite Tournaments to Minimize Total Travel Distance

abstract:
  In many professional sports leagues, teams from opposing leagues/conferences
compete against one another, playing inter-league games. This is an example of
a bipartite tournament. In this paper, we consider the problem of reducing the
total travel distance of bipartite tournaments, by analyzing inter-league
scheduling from the perspective of discrete optimization. This research has
natural applications to sports scheduling, especially for leagues such as the
National Basketball Association (NBA) where teams must travel long distances
across North America to play all their games, thus consuming much time, money,
and greenhouse gas emissions. We introduce the Bipartite Traveling Tournament
Problem (BTTP), the inter-league variant of the well-studied Traveling
Tournament Problem. We prove that the 2n-team BTTP is NP-complete, but for
small values of n, a distance-optimal inter-league schedule can be generated
from an algorithm based on minimum-weight 4-cycle-covers. We apply our
theoretical results to the 12-team Nippon Professional Baseball (NPB) league in
Japan, producing a provably-optimal schedule requiring 42950 kilometres of
total team travel, a 16% reduction compared to the actual distance traveled by
these teams during the 2010 NPB season. We also develop a nearly-optimal
inter-league tournament for the 30-team NBA league, just 3.8% higher than the
trivial theoretical lower bound.


title: Topological Value Iteration Algorithms

abstract:
  Value iteration is a powerful yet inefficient algorithm for Markov decision
processes (MDPs) because it puts the majority of its effort into backing up the
entire state space, which turns out to be unnecessary in many cases. In order
to overcome this problem, many approaches have been proposed. Among them, ILAO*
and variants of RTDP are state-of-the-art ones. These methods use reachability
analysis and heuristic search to avoid some unnecessary backups. However, none
of these approaches build the graphical structure of the state transitions in a
pre-processing step or use the structural information to systematically
decompose a problem, whereby generating an intelligent backup sequence of the
state space. In this paper, we present two optimal MDP algorithms. The first
algorithm, topological value iteration (TVI), detects the structure of MDPs and
backs up states based on topological sequences. It (1) divides an MDP into
strongly-connected components (SCCs), and (2) solves these components
sequentially. TVI outperforms VI and other state-of-the-art algorithms vastly
when an MDP has multiple, close-to-equal-sized SCCs. The second algorithm,
focused topological value iteration (FTVI), is an extension of TVI. FTVI
restricts its attention to connected components that are relevant for solving
the MDP. Specifically, it uses a small amount of heuristic search to eliminate
provably sub-optimal actions; this pruning allows FTVI to find smaller
connected components, thus running faster. We demonstrate that FTVI outperforms
TVI by an order of magnitude, averaged across several domains. Surprisingly,
FTVI also significantly outperforms popular heuristically-informed MDP
algorithms such as ILAO*, LRTDP, BRTDP and Bayesian-RTDP in many domains,
sometimes by as much as two orders of magnitude. Finally, we characterize the
type of domains where FTVI excels --- suggesting a way to an informed choice of
solver.


title:
Inference on Self-Exciting Jumps in Prices and Volatility using High
  Frequency Measures

abstract:
  Dynamic jumps in the price and volatility of an asset are modelled using a
joint Hawkes process in conjunction with a bivariate jump diffusion. A state
space representation is used to link observed returns, plus nonparametric
measures of integrated volatility and price jumps, to the specified model
components; with Bayesian inference conducted using a Markov chain Monte Carlo
algorithm. An evaluation of marginal likelihoods for the proposed model
relative to a large number of alternative models, including some that have
featured in the literature, is provided. An extensive empirical investigation
is undertaken using data on the S&P500 market index over the 1996 to 2014
period, with substantial support for dynamic jump intensities - including in
terms of predictive accuracy - documented.


title:
Pinning modes of high magnetic field Wigner solids with controlled alloy
  disorder

abstract:
  For a series of samples with 2D electron systems in dilute Al_x Ga_{1-x}As,
with varying x from 0 to 0.8 %, we survey the pinning mode resonances of Wigner
solids at the low Landau filling termination of the fractional quantum Hall
effect (FQHE) series. For all x studied, the pinning modes are present with
frequencies, f_pk, that are consistent with collective weak pinning. For
x>=0.22% we find f_pk vs B exhibits a rapid increase that is not present for
x=0. We find the observed f_pk is much smaller than values calculated with a
simple Wigner solid model which neglects the effects of the disorder on the
charge distribution of a carrier.


title: Nonlinear interaction of electromagnetic field with quantum plasma

abstract:
  The analysis of nonlinear interaction of transversal electromagnetic field
with quantum collisionless plasma is carried out. Formulas for calculation
electric current in quantum collisionless plasma at any temperature are
deduced. It has appeared, that the nonlinearity account leads to occurrence of
the longitudinal electric current directed along a wave vector. This second
current is orthogonal to the known transversal classical current, received at
the classical linear analysis. The case of degenerate electronic plasma is
considered. It is shown, that for degenerate plasmas the electric current is
calculated under the formula, not containing quadratures. In this formula we
have allocated known Kohn's singularities (W. Kohn, 1959).


title: Progress and Issues in Hadronic Theory

abstract:
  A brief review of progress and issues in hadronic theory and phenomenology is
presented. New results for the $X(3872)$, $Z_c(3900)$, and $Z_c(4020)$ are
discussed and unresolved issues are highlighted. A series of open problems in
pQCD, NRQCD, and general phenomenology is given. It is argued that these
indicate that the current understanding of hadronic dynamics is poor. In
particular old ideas about quark annihilation and factorisation appear to be
incorrect, pQCD looks limited in scope, and the convergence of some NRQCD
computations appears jeapardised by the relative lightness of the charm quark
mass.


title: Community Detection in Networks using Graph Distance

abstract:
  The study of networks has received increased attention recently not only from
the social sciences and statistics but also from physicists, computer
scientists and mathematicians. One of the principal problem in networks is
community detection. Many algorithms have been proposed for community finding
but most of them do not have have theoretical guarantee for sparse networks and
networks close to the phase transition boundary proposed by physicists. There
are some exceptions but all have some incomplete theoretical basis. Here we
propose an algorithm based on the graph distance of vertices in the network. We
give theoretical guarantees that our method works in identifying communities
for block models and can be extended for degree-corrected block models and
block models with the number of communities growing with number of vertices.
Despite favorable simulation results, we are not yet able to conclude that our
method is satisfactory for worst possible case. We illustrate on a network of
political blogs, Facebook networks and some other networks.


title: Quantum Hamiltonian Complexity

abstract:
  Constraint satisfaction problems are a central pillar of modern computational
complexity theory. This survey provides an introduction to the rapidly growing
field of Quantum Hamiltonian Complexity, which includes the study of quantum
constraint satisfaction problems. Over the past decade and a half, this field
has witnessed fundamental breakthroughs, ranging from the establishment of a
"Quantum Cook-Levin Theorem" to deep insights into the structure of 1D
low-temperature quantum systems via so-called area laws. Our aim here is to
provide a computer science-oriented introduction to the subject in order to
help bridge the language barrier between computer scientists and physicists in
the field. As such, we include the following in this survey: (1) The
motivations and history of the field, (2) a glossary of condensed matter
physics terms explained in computer-science friendly language, (3) overviews of
central ideas from condensed matter physics, such as indistinguishable
particles, mean field theory, tensor networks, and area laws, and (4) brief
expositions of selected computer science-based results in the area. For
example, as part of the latter, we provide a novel information theoretic
presentation of Bravyi's polynomial time algorithm for Quantum 2-SAT.


title: Strong and radiative decays of heavy mesons in a covariant model

abstract:
  In this paper, we investigate symmetry breaking effects in strong and
radiative decays of heavy mesons. We study $1/m_Q$ corrections within the heavy
quark effective theory. These effects are studied in a covariant model for
heavy mesons. The numerical results are consistent with the experimental data
and some other theoretical calculations. These provide a vote of confidence for
the validity of this covariant model.


title: A universal law in human mobility

abstract:
  The intrinsic factor that drives the human movement remains unclear for
decades. While our observations from intra-urban and inter-urban trips both
demonstrate a universal law in human mobility. Be specific, the probability
from one location to another is inversely proportional to the number of
population living in locations which are closer than the destination. A simple
rank-based model is then presented, which is parameterless but predicts human
flows with a convincing fidelity. Besides, comparison with other models shows
that our model is more stable and fundamental at different spatial scales by
implying the strong correlation between human mobility and social relationship.


title:
Mapping the large scale structure around a z=1.46 galaxy cluster in 3-D
  using two adjacent narrow-band filters

abstract:
  We present a novel method to estimate accurate redshifts of star-forming
galaxies by measuring the flux ratio of the same emission line observed through
two adjacent narrow-band filters. We apply this method to our NB912 and new
NB921 data taken with Suprime-Cam on the Subaru Telescope of a galaxy cluster,
XMMXCS J2215.9-1738, at z=1.46 and its surrounding structures. We obtain
redshifts for 170 [OII] emission line galaxies at z~1.46, among which 41
galaxies are spectroscopically confirmed with MOIRCS and FMOS on the Subaru
mainly, showing an accuracy of $\sigma$((z-z_spec})/(1+z_spec))=0.002. This
allows us to reveal filamentary structures that penetrate towards the centre of
the galaxy cluster and intersect with other structures, consistent with the
picture of hierarchical cluster formation. We also find that the projected
celestial distribution does not precisely trace the real distribution of
galaxies, indicating the importance of the three dimensional view of structures
to properly identify and quantify galaxy environments. We investigate the
environmental dependence of galaxy properties with local density, confirming
that the median colour of galaxies becomes redder in higher density region
while the star-formation rate of star-forming galaxies does not depend strongly
on local environment in this structure. This implies that the star-forming
activity in galaxies is truncated on a relatively short time scale in the
cluster centre.


title:
Statistics of reversible transitions in two-state trajectories in
  force-ramp spectroscopy

abstract:
  A possible way to extract information about the reversible dissociation of a
molecular adhesion bond from force fluctuations observed in force ramp
experiments is discussed. For small loading rates the system undergoes a
limited number of unbinding and rebinding transitions observable in the
so-called force versus extension (FE) curves. The statistics of these transient
fluctuations can be utilized to estimate the parameters for the rebinding rate.
This is relevant in the experimentally important situation where the direct
observation of the reversed FE-curves is hampered, e.g. due to the presence of
soft linkers. I generalize the stochastic theory of the kinetics in two-state
models to the case of time-dependent kinetic rates and compute the relevant
distributions of characteristic forces. While for irreversible systems there is
an intrinsic relation between the rupture force distribution and the population
of the free-energy well of the bound state, the situation is slightly more
complex if reversible systems are considered. For a two-state model, a
'stationary' rupture force distribution that is proportional to the population
can be defined and allows to consistently discuss quantities averaged over the
transient fluctuations. While irreversible systems are best analyzed in the
soft spring limit of small pulling device stiffness and large loading rates,
here I argue to use the stiffness of the pulling device as a control parameter
in addition to the loading rate.


title:
A stochastic control approach to no-arbitrage bounds given marginals,
  with an application to lookback options

abstract:
  We consider the problem of superhedging under volatility uncertainty for an
investor allowed to dynamically trade the underlying asset, and statically
trade European call options for all possible strikes with some given maturity.
This problem is classically approached by means of the Skorohod Embedding
Problem (SEP). Instead, we provide a dual formulation which converts the
superhedging problem into a continuous martingale optimal transportation
problem. We then show that this formulation allows us to recover previously
known results about lookback options. In particular, our methodology induces a
new proof of the optimality of Az\'{e}ma-Yor solution of the SEP for a certain
class of lookback options. Unlike the SEP technique, our approach applies to a
large class of exotics and is suitable for numerical approximation techniques.


title:
Discrete Convexity and Stochastic Approximation for Cross-layer On-off
  Transmission Control

abstract:
  This paper considers the discrete convexity of a cross-layer on-off
transmission control problem in wireless communications. In this system, a
scheduler decides whether or not to transmit in order to optimize the long-term
quality of service (QoS) incurred by the queueing effects in the data link
layer and the transmission power consumption in the physical (PHY) layer
simultaneously. Using a Markov decision process (MDP) formulation, we show that
the optimal policy can be determined by solving a minimization problem over a
set of queue thresholds if the dynamic programming (DP) is submodular. We prove
that this minimization problem is discrete convex. In order to search the
minimizer, we consider two discrete stochastic approximation (DSA) algorithms:
discrete simultaneous perturbation stochastic approximation (DSPSA) and
L-natural-convex stochastic approximation (L-natural-convex SA). Through
numerical studies, we show that the two DSA algorithms converge significantly
faster than the existing continuous simultaneous perturbation stochastic
approximation (CSPSA) algorithm in multi-user systems. Finally, we compare the
convergence results and complexity of two DSA and CSPSA algorithms where we
show that DSPSA achieves the best trade-off between complexity and accuracy in
multi-user systems.


title: A Note On Characterizations of Spherical t-Designs

abstract:
  A set ${X}_{N}=\{x_1,\ldots,x_N\}$ of $N$ points on the unit sphere
$\mathbb{S}^d,\,d\geq 2$ is a spherical $t$-design if the average of any
polynomial of degree at most $t$ over the sphere is equal to the average value
of the polynomial over ${X}_{N}$. This paper extends characterizations of
spherical $t$-designs in previous paper from $\mathbb{S}^2$ to general
$\mathbb{S}^d$. We show that for $N\geq\dim(\mathbb{P}_{t+1})$, $X_N$ is a
stationary point set of a certain non-negative quantity $A_{N,\,t}$ and a
fundamental system for polynomial space over $\mathbb{S}^d$ with degree at most
$t$, then $X_N$ is a spherical $t$-design. In contrast, we present that with $N
\geq \dim( \mathbb{P}_{t})$, a fundamental system $X_N$ is a spherical
$t$-design if and only if non-negative quantity $D_{N,\,t}$ vanishes. In
addition, the still unanswered questions about construction of spherical
$t$-designs are discussed.


title: Crossover behavior of conductivity in a discontinuous percolation model

abstract:
  When conducting bonds are occupied randomly in a two-dimensional square
lattice, the conductivity of the system increases continuously as the density
of those conducting bonds exceeds the percolation threshold. Such a behavior is
well known in percolation theory; however, the conductivity behavior has not
been studied yet when the percolation transition is discontinuous. Here we
investigate the conductivity behavior through a discontinuous percolation model
evolving under a suppressive external bias. Using effective medium theory, we
analytically calculate the conductivity behavior as a function of the density
of conducting bonds. The conductivity function exhibits a crossover behavior
from a drastically to a smoothly increasing function beyond the percolation
threshold in the thermodynamic limit. The analytic expression fits well our
simulation data.


title:
Decompositions of Edge-Colored Digraphs: A New Technique in the
  Construction of Constant-Weight Codes and Related Families

abstract:
  We demonstrate that certain Johnson-type bounds are asymptotically exact for
a variety of classes of codes, namely, constant-composition codes, nonbinary
constant-weight codes and multiply constant-weight codes. This was achieved via
an interesting application of the theory of decomposition of edge-colored
digraphs.


title: Semistable Reduction of a Normal Crossing $\mathbb{Q}$-Divisor

abstract:
  In a previous work we have introduced the notion of embedded
$\mathbf{Q}$-resolution, which essentially consists in allowing the final
ambient space to contain abelian quotient singularities, and A'Campo's formula
was calculated in this setting. Here we study the semistable reduction
associated with an embedded $\mathbf{Q}$-resolution so as to compute the mixed
Hodge structure on the cohomology of the Milnor fiber in the isolated case
using a generalization of Steenbrink's spectral sequence. Examples of
Yomdin-L\^{e} surface singularities are presented as an application.


title: Magnet Quench 101

abstract:
  This paper gives a broad summary of the physical phenomena associated with
the quench of a superconducting magnet.


title:
Multiply Constant-Weight Codes and the Reliability of Loop Physically
  Unclonable Functions

abstract:
  We introduce the class of multiply constant-weight codes to improve the
reliability of certain physically unclonable function (PUF) response. We extend
classical coding methods to construct multiply constant-weight codes from known
$q$-ary and constant-weight codes. Analogues of Johnson bounds are derived and
are shown to be asymptotically tight to a constant factor under certain
conditions. We also examine the rates of the multiply constant-weight codes and
interestingly, demonstrate that these rates are the same as those of
constant-weight codes of suitable parameters. Asymptotic analysis of our code
constructions is provided.


title: On integration of multidimensional version of $n$-wave type equation

abstract:
  We represent a version of multidimensional quasilinear partial differential
equation (PDE) together with large manifold of particular solutions given in an
integral form. The dimensionality of constructed PDE can be arbitrary. We call
it the $n$-wave type PDE, although the structure of its nonlinearity differs
from that of the classical completely integrable (2+1)-dimensional $n$-wave
equation. The richness of solution space to such a PDE is characterized by a
set of arbitrary functions of several variables. However, this richness is not
enough to provide the complete integrability, which is shown explicitly. We
describe a class of multi-solitary wave solutions in details. Among examples of
explicit particular solutions, we represent a lump-lattice solution depending
on five independent variables. In Appendix, as an important supplemental
material, we show that our nonlinear PDE is reducible from the more general
multidimensional PDE which can be derived using the dressing method based on
the linear integral equation with the kernel of a special type (a modification
of the $\bar\partial$-problem). The dressing algorithm gives us a key for
construction of higher order PDEs, although they are not discussed in this
paper.


title: Beyond Mumford's theorem on normal surfaces

abstract:
  Beyond normal surfaces there are several open questions concerning 2-
dimensional spaces. We present some results and conjectures along this line.


title: Quench limits in the next generation of magnets

abstract:
  Several projects around the planet aim at building a new generation of
superconducting magnets for particle accelerators, relying on Nb3Sn conductor,
with peak fields in the range of 10-15 T. In this paper we give an overview of
the main challenges for protecting this new generation of magnets. The cases of
isolated short magnets, in which the energy can be extracted on an external
dump resistor, and chain of long magnets, which have to absorb their stored
energy and have to rely on quench heaters, are discussed. We show that this new
generation of magnets can pose special challenges, related to both the large
current density and to the energy densities.


title:
Polynomial normal forms of Constrained Differential Equations with three
  parameters

abstract:
  We study generic constrained differential equations (CDEs) with three
parameters, thereby extending Takens's classification of singularities of such
equations. In this approach, the singularities analyzed are the Swallowtail,
the Hyperbolic, and the Elliptic Umbilics. We provide polynomial local normal
forms of CDEs under topological equivalence. Generic CDEs are important in the
study of slow-fast (SF) systems. Many properties and the characteristic
behavior of the solutions of SF systems can be inferred from the corresponding
CDE. Therefore, the results of this paper show a first approximation of the
flow of generic SF systems with three slow variables.


title: Many-server heavy-traffic limit for queues with time-varying parameters

abstract:
  A many-server heavy-traffic FCLT is proved for the $G_t/M/s_t+\mathit {GI}$
queueing model, having time-varying arrival rate and staffing, a general
arrival process satisfying a FCLT, exponential service times and customer
abandonment according to a general probability distribution. The FCLT provides
theoretical support for the approximating deterministic fluid model the authors
analyzed in a previous paper and a refined Gaussian process approximation,
using variance formulas given here. The model is assumed to alternate between
underloaded and overloaded intervals, with critical loading only at the
isolated switching points. The proof is based on a recursive analysis of the
system over these successive intervals, drawing heavily on previous results for
infinite-server models. The FCLT requires careful treatment of the initial
conditions for each interval.


title: Quench protection analysis in accelerator magnets, a review of the tools

abstract:
  As accelerator magnets see the increase of their magnetic field and stored
energy, quench protection becomes a critical part of the magnet design. Due to
the complexity of the quench phenomenon interweaving magnetic, electrical and
thermal analysis, the use of numerical codes is a key component of the process.
In that respect, we propose here a review of several tools commonly used in the
magnet design community.


title: Algebraic rank on hyperelliptic graphs and graphs of genus $3$

abstract:
  Let $\bar{G} = (G, \omega)$ be a vertex-weighted graph, and $\delta$ a
divisor class on $G$. Let $r_{\bar{G}}(\delta)$ denote the combinatorial rank
of $\delta$. Caporaso has introduced the algebraic rank
$r_{\bar{G}}^{\operatorname{alg}}(\delta)$ of $\delta$, by using nodal curves
with dual graph $\bar{G}$. In this paper, when $\bar{G}$ is hyperelliptic or of
genus $3$, we show that $r_{\bar{G}}^{\operatorname{alg}}(\delta) \geq
r_{\bar{G}}(\delta)$ holds, generalizing our previous result. We also show
that, with respect to the specialization map from a non-hyperelliptic curve of
genus $3$ to its reduction graph, any divisor on the graph lifts to a divisor
on the curve of the same rank.


title: Cyber Security of Smart Grid Infrastructure

abstract:
  Smart grid security is crucial to maintain stable and reliable power system
operation during the contingency situation due to the failure of any critical
power system component. Ensuring a secured smart grid involves with a less
possibility of power grid collapse or equipment malfunction. Due to lack of the
proper security measures, a major blackout may occur which can even lead to a
cascading failure. Therefore, to protect this critical power system
infrastructure and to ensure a reliable and an uninterrupted power supply to
the end users, smart grid security issues must be addressed with high priority.
In a smart grid environment, electric power infrastructure is modernized by
incorporating the current and future requirements and advanced functionalities
to its consumers. To make the smart grid happen, cyber system is integrated
with the physical power system. Although adoption of cyber system has made the
grid more energy efficient and modernized, it has introduced cyber-attack
issues which are critical for national infrastructure security and customer
satisfaction. Due to the cyber-attack, power grid may face operational failures
and loss of synchronization. This operational failure may damage critical power
system components which may interrupt the power supply and make the system
unstable resulting high financial penalties. In this chapter, some recent cyber
attack related incidents into a smart grid environment are discussed. The
requirements and the state of the art of cyber security issues of a critical
power system infrastructure are illustrated elaborately.


title: Quench in high temperature superconductor magnets

abstract:
  High field superconducting magnets using high temperature superconductors are
being developed for high energy physics, nuclear magnetic resonance and energy
storage applications. Although the conductor technology has progressed to the
point where such large magnets can be readily envisioned, quench protection
remains a key challenge. It is well-established that quench propagation in HTS
magnets is very slow and this brings new challenges that must be addressed. In
this paper, these challenges are discussed and potential solutions, driven by
new technologies such as optical fiber based sensors and thermally conducting
electrical insulators, are reviewed.


title:
Robust Modulation Technique for Diffusion-based Molecular Communication
  in Nanonetworks

abstract:
  Diffusion-based molecular communication over nanonetworks is an emerging
communication paradigm that enables nanomachines to communicate by using
molecules as the information carrier. For such a communication paradigm,
Concentration Shift Keying (CSK) has been considered as one of the most
promising techniques for modulating information symbols, owing to its inherent
simplicity and practicality. CSK modulated subsequent information symbols,
however, may interfere with each other due to the random amount of time that
molecules of each modulated symbols take to reach the receiver nanomachine. To
alleviate Inter Symbol Interference (ISI) problem associated with CSK, we
propose a new modulation technique called Zebra-CSK. The proposed Zebra-CSK
adds inhibitor molecules in CSK-modulated molecular signal to selectively
suppress ISI causing molecules. Numerical results from our newly developed
probabilistic analytical model show that Zebra-CSK not only enhances capacity
of the molecular channel but also reduces symbol error probability observed at
the receiver nanomachine.


title:
Modeling heat transfer from quench protection heaters to superconducting
  cables in Nb3Sn magnets

abstract:
  We use a recently developed quench protection heater modeling tool for an
analysis of heater delays in superconducting high-field Nb3Sn accelerator
magnets. The results suggest that the calculated delays are consistent with
experimental data, and show how the heater delay depends on the main heater
design parameters.


title:
Nonparametric Latent Tree Graphical Models: Inference, Estimation, and
  Structure Learning

abstract:
  Tree structured graphical models are powerful at expressing long range or
hierarchical dependency among many variables, and have been widely applied in
different areas of computer science and statistics. However, existing methods
for parameter estimation, inference, and structure learning mainly rely on the
Gaussian or discrete assumptions, which are restrictive under many
applications. In this paper, we propose new nonparametric methods based on
reproducing kernel Hilbert space embeddings of distributions that can recover
the latent tree structures, estimate the parameters, and perform inference for
high dimensional continuous and non-Gaussian variables. The usefulness of the
proposed methods are illustrated by thorough numerical results.


title: Network Coding for $3$s$/n$t Sum-Networks

abstract:
  A sum-network is a directed acyclic network where each source independently
generates one symbol from a given field $\mathbb F$ and each terminal wants to
receive the sum $($over $\mathbb F)$ of the source symbols. For sum-networks
with two sources or two terminals, the solvability is characterized by the
connection condition of each source-terminal pair [3]. A necessary and
sufficient condition for the solvability of the $3$-source $3$-terminal
$(3$s$/3$t$)$ sum-networks was given by Shenvi and Dey [6]. However, the
general case of arbitrary sources/sinks is still open. In this paper, we
investigate the sum-network with three sources and $n$ sinks using a region
decomposition method. A sufficient and necessary condition is established for a
class of $3$s$/n$t sum-networks. As a direct application of this result, a
necessary and sufficient condition of solvability is obtained for the special
case of $3$s$/3$t sum-networks.


title: Jamming by Shape in Kinetically-Constrained Models

abstract:
  We derive expressions for the critical density for jamming in a
hyper-rhomboid system of arbitrary shape in any dimension for the Kob-Andersen
and Fredrickson-Andersen kinetically-constrained models. We find that changing
the system's shape without altering its total volume or particle density may
induce jamming. We also find a transition between shapes in which the
correlation length between jammed particles is infinite, and shapes that have a
finite correlation length.


title: Formation History of Polycyclic Aromatic Hydrocarbons in Galaxies

abstract:
  Polycyclic aromatic hydrocarbons (PAHs) are some of the major dust components
in the interstellar medium (ISM). We present our evolution models for the
abundance of PAHs in the ISM on a galaxy-evolution timescale. We consider
shattering of carbonaceous dust grains in interstellar turbulence as the
formation mechanism of PAHs while the PAH abundance can be reduced by
coagulation onto dust grains, destruction by supernova shocks, and
incorporation into stars. We implement these processes in a one-zone chemical
evolution model to obtain the evolution of the PAH abundance in a galaxy. We
find that PAH formation becomes accelerated above certain metallicity where
shattering becomes efficient. For PAH destruction, while supernova shock is the
primary mechanism in the metal-poor environment, coagulation is dominant in the
metal-rich environment. We compare the evolution of the PAH abundances in our
models with observed abundances in galaxies with a wide metallicity range. Our
models reproduce both the paucity of PAH detection in low metallicity galaxies
and the metallicity-dependence of the PAH abundance in high-metallicity
galaxies. The strong metallicity dependence of PAH abundance appears as a
result of the strong metallicity dependence of the dust mass increase by the
accretion of metals onto dust grains, which are eventually shattered into PAHs.
We conclude that the observational trend of the PAH abundance can be a natural
consequence of shattering of carbonaceous grains being the source of PAHs. To
establish our scenario of PAH formation, observational evidence of PAH
formation by shattering would be crucial.


abstract:
  A note on "Bayesian nonparametric estimators derived from conditional Gibbs
structures" by Antonio Lijoi, Igor Pr\"{u}nster, Stephen G. Walker
[arXiv:0808.2863].


title:
Distributed Remote Vector Gaussian Source Coding for Wireless Acoustic
  Sensor Networks

abstract:
  In this paper, we consider the problem of remote vector Gaussian source
coding for a wireless acoustic sensor network. Each node receives messages from
multiple nodes in the network and decodes these messages using its own
measurement of the sound field as side information. The node's measurement and
the estimates of the source resulting from decoding the received messages are
then jointly encoded and transmitted to a neighboring node in the network. We
show that for this distributed source coding scenario, one can encode a
so-called conditional sufficient statistic of the sources instead of jointly
encoding multiple sources. We focus on the case where node measurements are in
form of noisy linearly mixed combinations of the sources and the acoustic
channel mixing matrices are invertible. For this problem, we derive the
rate-distortion function for vector Gaussian sources and under covariance
distortion constraints.


title: Selective altruism in collective games

abstract:
  We study the emergence of altruistic behaviour in collective games. In
particular, we take into account Toral's version of collective Parrondo's
paradoxical games, in which the redistribution of capital between agents, who
can play different strategies, creates a positive trend of increasing capital.
In this framework, we insert two categories of players, altruistic and selfish
ones, and see how they interact and how their capital evolves. More in detail,
we analyse the positive effects of altruistic behaviour, but we also point out
how selfish players take advantage of that situation. The general result is
that altruistic behaviour is discouraged, because selfish players get richer
while altruistic ones get poorer. We also consider a smarter way of being
altruistic, based on reputation, called "selective altruism", which prevents
selfish players from taking advantage of altruistic ones. In this new situation
it is altruism, and not selfishness, to be encouraged and stabilized. Finally,
we introduce a mechanism of imitation between players and study how it
influences the composition of the population of both altruistic and selfish
players as a function of time for different initial conditions and network
topologies adopted.


title:
Scaling analysis of field-induced superconductor-insulator transition in
  two-dimensional tantalum thin films

abstract:
  The superconductor-insulator (SI) transition in two-dimensional Ta thin films
is investigated by controlling both film thickness and magnetic field. An
intriguing metallic phase intervening superconductor and an insulator phase is
observed within a narrow range of film thickness and magnetic field. Finite
scaling analysis has been performed to investigate the nature of the SI
transition in the thickness-tuned metallic and superconducting samples. The
critical exponents in the disorder-induced metallic samples are clearly
different from the exponents obtained in the superconducting samples. Dynamical
exponent z of the superconducting samples is consistent with the theoretical
predictions (z = 1), while the exponent for the metallic samples is
approximately 0.7. The discrepancy in the transition behaviors supports that
the disorder induced metallic phase cannot be classified to the same
universality class of the superconducting Ta thin films.


title: Bound states of massive fermions in the Aharonov--Bohm-like fields

abstract:
  Bound states of massive fermions in the Aharonov-Bohm like fields have
analytically been studied. The Hamiltonians with the Aharonov--Bohm like
potentials are essentially singular and therefore require specification of a
one-parameter self-adjoint extension. We construct self-adjoint Dirac
Hamiltonians with the Aharonov-Bohm (AB) potential in 2+1 dimensions that are
specified by boundary conditions at the origin. It is of interest that for some
range of extension parameter the AB potential can bind relativistic charged
massive fermions. The bound-state energy is determined by the AB magnetic flux
and depends upon fermion spin and extension parameter; it is a periodical
function of the magnetic flux. We also construct self-adjoint Hamiltonians for
the so-called Aharonov-Casher (AC) problem, show that nonrelativistic neutral
massive fermions can be bound by the Aharonov-Casher background, determine the
range of extension parameter in which fermion bound states exist and find their
energies as well as wave functions.


title: Parallel Texture Structures with Cofactor Zeros in Lepton Sector

abstract:
  In this paper we investigate the parallel texture structures with cofactor
zeros in the charged lepton and neutrino sectors. The textures can not be
obtained from arbitrary leptonic matrices by making weak basis transformations,
which therefore have physical meaning. The 15 parallel textures are grouped as
4 classes where each class has the same physical implications. It is founded
that one of them is not phenomenological viable and another is equivalent to
the texture zero structures extensively explored in previous literature. Thus
we focus on the other two classes of parallel texture structures and study the
their phenomenological implications. The constraints on the physical variables
are obtained for each class, which are essential for the model selection and
can be measured by future experiments. The model realization is illustrated in
a radiated lepton mass model.


title:
Acoustic detection in superconducting magnets for performance
  characterization and diagnostics

abstract:
  Quench diagnostics in superconducting accelerator magnets is essential for
understanding performance limitations and improving magnet design.
Applicability of the conventional quench diagnostics methods such as voltage
taps or quench antennas is limited for long magnets or complex winding
geometries, and alternative approaches are desirable. Here, we discuss acoustic
sensing technique for detecting mechanical vibrations in superconducting
magnets. Using LARP high-field Nb3Sn quadrupole HQ01 [1], we show how acoustic
data is connected with voltage instabilities measured simultaneously in the
magnet windings during provoked extractions and current ramps to quench.
Instrumentation and data analysis techniques for acoustic sensing are reviewed.


title: Beam Extraction and Transport

abstract:
  This chapter gives an introduction to low-energy beam transport systems, and
discusses the typically used magnetostatic elements (solenoid, dipoles and
quadrupoles) and electrostatic elements (einzel lens, dipoles and quadrupoles).
The ion beam emittance, beam space-charge effects and the physics of ion source
extraction are introduced. Typical computer codes for analysing and designing
ion optical systems are mentioned, and the trajectory tracking method most
often used for extraction simulations is described in more detail.


title:
Isoscalar giant monopole resonance for drip-line and super heavy nuclei
  in the framework of a relativistic mean field formalism with scaling
  calculation

abstract:
  We study the isoscalar giant monopole resonance for drip-lines and super
heavy nuclei in the frame work of a relativistic mean field theory with scaling
approach. The well known extended Thomas-Fermi approximation in the non-linear
$\sigma$-$\omega$ model is used to estimate the giant monopole excitation
energy for some selected light spherical nuclei starting from the region of
proton to neutron drip-lines. The application is extended to super heavy region
for Z=114 and 120, which are predicted by several models as the next proton
magic number beyond Z=82. We compared the excitation energy obtained by four
successful force parameters NL1, NL3, NL3$^*$ and FSUGold. The monopole energy
decreases toward the proton and neutron drip-lines in an isotopic chain for
lighter mass nuclei contrary to a monotonous decrease for super heavy isotopes.
The maximum and minimum monopole excitation energies are obtained for nuclei
with minimum and maximum isospin, respectively in an isotopic chain.


title: Q-alpha values in superheavy nuclei from the deformed Woods-Saxon model

abstract:
  Masses of superheavy (SH) nuclei with $Z=98-128$, including odd and odd-odd
nuclei, are systematically calculated within the microscopic-macroscopic model
based on the deformed Woods-Saxon potential. Ground states are found by
minimizing energy over deformations and configurations. Pairing in odd
particle-number systems is treated either by blocking or by adding the BCS
energy of the odd quasiparticle. Three new parameters are introduced which may
be interpreted as the constant mean pairing energies for even-odd, odd-even and
odd-odd nuclei. They are adjusted by a fit to masses of heavy nuclei. Other
parameters of the model, fixed previously by fitting masses of even-even heavy
nuclei, are kept unchanged. With this adjustment, the masses of SH nuclei are
predicted and then used to calculate $\alpha$-decay energies to be compared to
known measured values. It turns out that the agreement between calculated
$Q_{\alpha}$ values with data in SH nuclei is better than in the region of the
mass fit. The model overestimates $Q_{\alpha}$ for $Z=111-113$. Ground state
(g.s.) configurations in some SH nuclei hint to a possible $\alpha$-decay
hindrance. The calculated configuration-preserving transition energies show
that in some cases this might explain discrepancies, but more data is needed to
explain the situation.


title: The nucleon spin decomposition: news and experimental implications

abstract:
  Recently, many nucleon spin decompositions have been proposed in the
literature, creating a lot of confusion. This revived in particular old
controversies regarding the measurability of theoretically defined quantities.
We propose a brief overview of the different decompositions, discuss the
sufficient requirements for measurability and stress the experimental
implications.


title: Maximum allowable temperature during quench in Nb3Sn accelerator magnets

abstract:
  This note aims at understanding the maximum allowable temperature at the hot
spot during a quench in Nb3Sn accelerator magnets, through the analysis of
experimental results previously presented.


title:
Superlinear and sublinear urban scaling in geographical network model of
  the city

abstract:
  Using a geographical scale-free network to describe relations between people
in a city, we explain both superlinear and sublinear allometric scaling of
urban indicators that quantify activities or performances of the city. The
urban indicator $Y(N)$ of a city with the population size $N$ is analytically
calculated by summing up all individual activities produced by person-to-person
relationships. Our results show that the urban indicator scales superlinearly
with the population, namely, $Y(N)\propto N^{\beta}$ with $\beta>1$ if $Y(N)$
represents a creative productivity and the indicator scales sublinearly
($\beta<1$) if $Y(N)$ is related to the degree of infrastructure development.
These coincide with allometric scaling observed in real-world urban indicators.
We also show how the scaling exponent $\beta$ depends on the strength of the
geographical constraint in the network formation.


title: Exact and Approximate Determinization of Discounted-Sum Automata

abstract:
  A discounted-sum automaton (NDA) is a nondeterministic finite automaton with
edge weights, valuing a run by the discounted sum of visited edge weights. More
precisely, the weight in the i-th position of the run is divided by
$\lambda^i$, where the discount factor $\lambda$ is a fixed rational number
greater than 1. The value of a word is the minimal value of the automaton runs
on it. Discounted summation is a common and useful measuring scheme, especially
for infinite sequences, reflecting the assumption that earlier weights are more
important than later weights. Unfortunately, determinization of NDAs, which is
often essential in formal verification, is, in general, not possible. We
provide positive news, showing that every NDA with an integral discount factor
is determinizable. We complete the picture by proving that the integers
characterize exactly the discount factors that guarantee determinizability: for
every nonintegral rational discount factor $\lambda$, there is a
nondeterminizable $\lambda$-NDA. We also prove that the class of NDAs with
integral discount factors enjoys closure under the algebraic operations min,
max, addition, and subtraction, which is not the case for general NDAs nor for
deterministic NDAs. For general NDAs, we look into approximate determinization,
which is always possible as the influence of a word's suffix decays. We show
that the naive approach, of unfolding the automaton computations up to a
sufficient level, is doubly exponential in the discount factor. We provide an
alternative construction for approximate determinization, which is singly
exponential in the discount factor, in the precision, and in the number of
states. We also prove matching lower bounds, showing that the exponential
dependency on each of these three parameters cannot be avoided. All our results
hold equally for automata over finite words and for automata over infinite
words.


title: Experimental results and analysis from the 11 T Nb3Sn DS dipole

abstract:
  FNAL and CERN are developing a 5.5-m-long twin-aperture Nb3Sn dipole suitable
for installation in the LHC. A 2-m-long single-aperture demonstrator dipole
with 60 mm bore, a nominal field of 11 T at the LHC nominal current of 11.85 kA
and 20% margin has been developed and tested. This paper presents the results
of quench protection analysis and protection heater study for the Nb3Sn
demonstrator dipole. Extrapolations of the results for long magnet and
operation in LHC are also presented.


title:
Electric field driven magnetic domain wall motion in
  ferromagnetic-ferroelectric heterostructures

abstract:
  We investigate magnetic domain wall (MDW) dynamics induced by applied
electric fields in ferromagnetic-ferroelectric thin-film heterostructures. In
contrast to conventional driving mechanisms where MDW motion is induced
directly by magnetic fields or electric currents, MDW motion arises here as a
result of strong pinning of MDWs onto ferroelectric domain walls (FDWs) via
local strain coupling. By performing extensive micromagnetic simulations, we
find several dynamical regimes, including instabilities such as spin wave
emission and complex transformations of the MDW structure. In all cases, the
time-averaged MDW velocity equals that of the FDW, indicating the absence of
Walker breakdown.


title:
Models and experimental results from the wide aperture Nb-Ti magnets for
  the LHC upgrade

abstract:
  MQXC is a Nb-Ti quadrupole designed to meet the accelerator quality
requirements needed for the phase-1 LHC upgrade, now superseded by the high
luminosity upgrade foreseen in 2021. The 2-m-long model magnet was tested at
room temperature and 1.9 K. The technology developed for this magnet is
relevant for other magnets currently under development for the high-luminosity
upgrade, namely D1 (at KEK) and the large aperture twin quadrupole Q4 (at CEA).
In this paper we present MQXC test results, some of the specialized heat
extraction features, spot heaters, temperature sensor mounting and voltage tap
development for the special open cable insulation. We look at some problem
solving with noisy signals, give an overview of electrical testing, look at how
we calculate the coil resistance during at quench and show that the heaters are
not working We describe the quench signals and its timing, the development of
the quench heaters and give an explanation of an Excel quench calculation and
its comparison including the good agreement with the MQXC test results. We
propose an improvement to the magnet circuit design to reduce voltage to ground
values by factor 2. The program is then used to predict quench Hot-Spot and
Voltages values for the D1 dipole and the Q4 quadrupole.


title: Protection of the 13 T Nb3Sn Fresca II dipole

abstract:
  The EuCARD project aims on construction of a 19 T hybrid dipole; it will be
made of a 6 T HTS dipole associated to a 13 T outsert Nb3Sn dipole [1]. This
paper reviews the quench analysis and protection of the 13 T Nb3Sn dipole.


title: Terzan 5: a pristine fragment of the Galactic Bulge?

abstract:
  Terzan 5 is a stellar system located in the inner Bulge of the Galaxy and has
been historically catalogued as a globular cluster. However, recent photometric
(Ferraro et al. 2009) and spectroscopic (Origlia et al. 2011; Origlia et al.
2013) investigations have shown that it hosts at least three stellar
populations with different iron abundances (with a total spread of
Delta[Fe/H]>1 dex) thus demonstrating that Terzan 5 is not a genuine globular
cluster. In addition, the striking similarity between the chemical patterns of
this system and those of its surrounding environment, the Galactic Bulge, from
the point of view of both the metallicity distribution and the alpha-element
enrichment, suggests that Terzan 5 could be a pristine fragment of the Bulge
itself.


title: Series of Tests of a Constraint on Asymptotically Free Gauge Theories

abstract:
  In 1999 Thomas Appelquist, Andrew G. Cohen, and Martin Schmaltz (ACS)
proposed a constraint on the structure of asymptotically-free field theories.
This constraint limits the number of degrees of freedom of asymptotically-free
gauge theories in the infrared ($IR$) region relative to those in the
ultra-violet ($UV$) region. In their paper ACS checked various examples, both
supersymmetric and non-supersymmetric, but checked only one case of interacting
$IR$ fixed point with superpotential - the case of Seiberg-dual of $SU(N_{c})$
gauge theory. Here we will verify the conjecture for two new cases -
$SO(N_{c})$ and $Sp(2N_{c})$ gauge groups around the Banks-Zaks fixed points.
In addition, we subject the ACS inequality to a series of nontrivial tests in
theories with conjectured accidental symmetries in the $IR$ and dramatically
different dynamics caused by superpotential deformations. We start with
$ADE$-type deformations then move on to check three chiral theories by
estimating their decoupled invariants from the chiral ring using a-maximization
and unitarity considerations. Remarkably, we found no violation of the ACS
conjecture.


title: Vector-boson pair production and electroweak corrections in HERWIG++

abstract:
  The detailed study of vector-boson pair production processes at the LHC will
lead to a better understanding of electroweak physics. As pointed out before, a
consistent inclusion of higher-order electroweak effects in the analysis of
corresponding experimental data may be crucial to properly predict the relevant
phenomenological features of these important reactions. Those contributions
lead to dramatic distortions of invariant-mass and angular distributions at
high energies, but may also significantly affect the cross section near
threshold, as is the case e.g. for Z-pairs. For this reason, we present an
analysis of the next-to-leading-order electroweak corrections to WW, WZ and ZZ
production at the LHC, taking into account mass effects as well as leptonic
decays. Hence, our predictions are valid in the whole kinematic reach of the
LHC and, moreover, respect the spin correlations of the leptonic decay products
at NLO accuracy. Starting from these fixed-order results, a simple and
straight-forward method is motivated to combine the electroweak corrections
with state-of-the-art Monte Carlo predictions, focusing on a meaningful
combination of higher-order electroweak and QCD effects. To illustrate our
approach, the electroweak corrections are implemented in the HERWIG++
generator, and their phenomenological effects within a QCD environment are
studied explicitly.


title: Mirror dark matter: Cosmology, galaxy structure and direct detection

abstract:
  A simple way to accommodate dark matter is to postulate the existence of a
hidden sector. That is, a set of new particles and forces interacting with the
known particles predominantly via gravity. In general this leads to a large set
of unknown parameters, however if the hidden sector is an exact copy of the
standard model sector, then an enhanced symmetry arises. This symmetry, which
can be interpreted as space-time parity, connects each ordinary particle ($e, \
\nu, \ p, \ n, \ \gamma, ....)$ with a mirror partner ($e', \ \nu', \ p', \ n',
\ \gamma', ...)$. If this symmetry is completely unbroken, then the mirror
particles are degenerate with their ordinary particle counterparts, and would
interact amongst themselves with exactly the same dynamics that govern ordinary
particle interactions. The only new interaction postulated is photon - mirror
photon kinetic mixing, whose strength $\epsilon$, is the sole new fundamental
(Lagrangian) parameter relevant for astrophysics and cosmology. It turns out
that such a theory, with suitably chosen initial conditions effective in the
very early Universe, can provide an adequate description of dark matter
phenomena provided that $\epsilon \sim 10^{-9}$. This review focuses on three
main developments of this mirror dark matter theory during the last decade:
Early universe cosmology, galaxy structure and the application to direct
detection experiments.


title:
Absence of quasiclassical coherence in mean-field dynamics of bosons in
  a kinetically frustrated regime

abstract:
  We study numerically the dynamics of bosons on a triangular lattice after
quenching both the on-site interactions and the external trapping potential to
negative values. In a similar situation on the square lattice, the dynamics can
be understood in terms of an effectively reversed Hamiltonian. On the
triangular lattice, however, the kinetic part of the reversed Hamiltonian is
frustrated and whether coherence can develop is an open question. The strength
of the frustration can be changed by tuning the ratio of the hopping rates
along different directions. We calculate time-of-flight images at different
times after the quench for different values of the hopping anisotropy. We
observe peaks at the maxima of the original non-interacting dispersion relation
both in the isotropic case and also in the rhombic limit of high hopping
anisotropy. For an intermediate value, however, no coherence develops up to the
longest simulation times. These results imply that experiments along similar
lines could study unconventional superfluidity of bosons and aspects of the
conjectured spin-liquid behavior in the hard-core limit.


title: Protection of the 6 T YBCO insert in the 13 T Nb3Sn Fresca II dipole

abstract:
  In the EuCARD project, we aim to construct a dipole magnet in YBCO producing
6 T in the background field of a 13 T Nb3Sn dipole FRESCA II. This paper
reviews the quench analysis and protection of the YBCO coil. In addition, a
recommendation for the protection system of the YBCO coil is presented.


title:
Role of the SU($2$) and SU($3$) subgroups in observing confinement in
  the G($2$) gauge group

abstract:
  Applying the domain model to the G($2$) gauge group and the thick center
vortex model to the SU($2$) and SU($3$) subgroups of G($2$), we calculate the
potentials between static sources, as well as some parameters of the vortex
profile. Comparing the results obtained from G($2$) and its subgroups, we argue
that SU($2$) and SU($3$) gauge groups have important roles in observing
confinement in the G($2$) gauge group.


title: Precise Phase Measurements using an Entangled Coherent State

abstract:
  Quantum entanglement offers the possibility of making measurements beyond the
classical limit, however some issues still need to be overcome before it can be
applied in realistic lossy systems. Recent work has used the quantum Fisher
information (QFI) to show that entangled coherent states (ECSs) may be useful
for this purpose as they combine sub-classical phase precision capabilities
with robustness (Joo et al., 2011). However, to date no effective scheme for
measuring a phase in lossy systems using an ECS has been devised. Here we
present a scheme that does just this. We show how one could measure a phase to
a precision significantly better than that attainable by both unentangled
"classical" states and highly-entangled NOON states over a wide range of
different losses. This brings quantum metrology closer to being a realistic and
practical technology.


title: The hadronic origin of hard gamma-ray spectrum from blazar 1ES 1101-232

abstract:
  The very hard $\gamma$-ray spectrum from distant blazars challenges the
traditional synchrotron self-Compton (SSC) model, which may indicate that there
is the contribution of an additional high-energy component beyond the SSC
emission. In this paper, we study the possible origin of the hard $\gamma$-ray
spectrum from distant blazars. We develop a model to explain the hard
$\gamma$-ray spectrum from blazar 1ES 1101-232. In the model, the optical and
X-ray radiation would come from the synchrotron radiation of primary electrons
and secondary pairs, the GeV emission would be produced by the SSC process,
however, the hard $\gamma$-ray spectrum would originate from the decay of
neutral pion produced through proton-photon interactions with the synchrotron
radiation photons within the jet. Our model can explain the observed SED of 1ES
1101-232 well, especially the very hard $\gamma$-ray spectrum. However, our
model requires the very large proton power to efficiently produce the
$\gamma$-ray through proton-photon interactions.


title:
The behaviour of copper in view of radiation damage in the LHC
  luminosity upgrade

abstract:
  In view of the safe operation of the quadrupoles in the luminosity upgrade of
the LHC accelerator, the response of the copper stabilizer at low temperatures
to the various high energy radiation sources is of primary importance. The
present study takes into account the expected high energy spectrum of the
simultaneous radiation by neutrons, protons, pions, electrons and photons,
calculated using the FLUKA code by F. Cerutti (CERN) as well as on literature
values. It was found that proton irradiation causes a considerably higher
damage than neutron irradiation: in spite of a 3.8% proton fraction, the
measured damage is of the order of 20%, which fits with the calculations of N.
Mokhov (Fermilab) on the contribution of protons to the dpa. The same
calculations indicate that the total effect of protons, pions and electrons is
at least as high as that of neutrons. Since recent neutron experiments of
Nakamoto et al. show that the RRR of Cu is reduced from 200 to 50-120 for a
fluence of 10^{21} n/cm^{2}, it follows that the inclusion of all high energy
sources would lead to RRR values well below 50, thus endangering stability and
protection. This result confirms the necessity of including a tungsten shield
inside the quadrupoles.


title: On massive sets for subordinated random walks

abstract:
  We study massive (reccurent) sets with respect to a certain random walk
$S_\alpha $ defined on the integer lattice $\mathbb{Z} ^d$, $d=1,2$. Our random
walk $S_\alpha $ is obtained from the simple random walk $S$ on $\mathbb{Z} ^d$
by the procedure of discrete subordination. $S_\alpha $ can be regarded as a
discrete space and time counterpart of the symmetric $\alpha $-stable L\'{e}vy
process in $\mathbb{R}^d$.
  In the case $d=1$ we show that some remarkable proper subsets of $\mathbb{Z}$
, e.g. the set $\mathcal{P}$ of primes, are massive whereas some proper subsets
of $\mathcal{P}$ such as Leitmann primes $\mathcal{P}_h$ are
massive/non-massive depending on the function $h$. Our results can be regarded
as an extension of the results of McKean (1961) about massiveness of the set of
primes for the simple random walk in $\mathbb{Z}^3$.
  In the case $d=2$ we study massiveness of thorns and their proper subsets.


title:
An Empirical Evaluation of Similarity Measures for Time Series
  Classification

abstract:
  Time series are ubiquitous, and a measure to assess their similarity is a
core part of many computational systems. In particular, the similarity measure
is the most essential ingredient of time series clustering and classification
systems. Because of this importance, countless approaches to estimate time
series similarity have been proposed. However, there is a lack of comparative
studies using empirical, rigorous, quantitative, and large-scale assessment
strategies. In this article, we provide an extensive evaluation of similarity
measures for time series classification following the aforementioned
principles. We consider 7 different measures coming from alternative measure
`families', and 45 publicly-available time series data sets coming from a wide
variety of scientific domains. We focus on out-of-sample classification
accuracy, but in-sample accuracies and parameter choices are also discussed.
Our work is based on rigorous evaluation methodologies and includes the use of
powerful statistical significance tests to derive meaningful conclusions. The
obtained results show the equivalence, in terms of accuracy, of a number of
measures, but with one single candidate outperforming the rest. Such findings,
together with the followed methodology, invite researchers on the field to
adopt a more consistent evaluation criteria and a more informed decision
regarding the baseline measures to which new developments should be compared.


title:
Towards Complete Phase Diagrams of a Holographic P-wave Superconductor
  Model

abstract:
  We study in detail the phase structure of a holographic p-wave superconductor
model in a five dimensional Einstein-Maxwell-complex vector field theory with a
negative cosmological constant. To construct complete phase diagrams of the
model, we consider both the soliton and black hole backgrounds. In both two
cases, there exist second order, first order and zeroth order phase
transitions, and the so-called "retrograde condensation" also happens. In
particular, in the soliton case with the mass of the vector field being beyond
a certain critical value, we find a series of phase transitions happen such as
"insulator/superconductor/insulator/superconductor", as the chemical potential
continuously increases. We construct complete phase diagrams in terms of
temperature and chemical potential and find some new phase boundaries.


title: Homotopy colimits of nilpotent spaces

abstract:
  We show that cellular approximations of nilpotent Postnikov stages are always
nilpotent Postnikov stages, in particular classifying spaces of nilpotent
groups are turned into classifying spaces of nilpotent groups. We use a
modified Bousfield-Kan homology completion tower z_k X whose terms we prove are
all X-cellular for any X. As straightforward consequences, we show that if X is
K-acyclic and nilpotent for a given homology theory K, then so are all its
Postnikov sections, and that any nilpotent space for which the space of pointed
self-maps map_*(X,X) is "canonically" discrete must be aspherical.


title:
Chemical abundances of blue straggler stars in Galactic Globular
  Clusters

abstract:
  By using the high resolution spectrograph FLAMES@VLT we performed the first
systematic campaign devoted to measure chemical abundances of blue straggler
stars (BSSs). These stars, whose existence is not predicted by the canonical
stellar evolutionary theory, are likely the product of the interactions between
stars in the dense environment of Globular Clusters. Two main scenarios for BSS
formation (mass transfer in binary systems and stellar collisions) have been
proposed and hydrodynamical simulations predict different chemical patterns in
the two cases, in particular C and O depletion for mass transfer BSSs. In this
contribution, the main results for BSS samples in 6 Globular Clusters and their
interpretation in terms of BSS formation processes are discussed. For the first
time, evidence of radiative levitation in the shallow envelopes of BSSs hotter
than $\sim$8000 K has been found. C and O depletion for some BSSs has been
detected in 47 Tucanae, M30 and $\omega$ Centauri thus suggesting a mass
transfer origin for these BSSs. The low percentage of CO-depleted BSSs suggests
that depletion might be a transient phenomenon.


title: The Leptonic CP Phase from Muon Decay at Rest with Two Detectors

abstract:
  We propose a novel experimental setup for the determination of the leptonic
CP-violating phase delta using the decay at rest (DAR) of mu+ from a single
source located at distances of 10 and 30 km from two 20 kton organic liquid
scintillator detectors. The mu+ are created by bombarding a target with a 9 mA
beam of 800 MeV protons. With this proposal delta can be determined with a
precision of about 20 (15) degrees in 6 (12) years. In contrast with the
DAEdALUS project, only a single source is required and it runs with a duty
factor of 100 percent. Therefore 9 mA is the maximum instanteous current,
greatly reducing both the technological challenges and the costs.


title:
Dynamical decoupling and dynamical isolation in temporally modulated
  coupled pendulums

abstract:
  We theoretically study the dynamics of a pair of coupled pendulums subject to
a periodic temporal modulation of their oscillation frequency. Inspired from
analogous developments in quantum mechanics, we anticipate dynamical
localization and dynamical isolation effects, as well as the occurrence of
non-trivial coupling phases. Perspectives in the direction of studying
synthetic gauge fields in a classical mechanics context are outlined.


title: Elastic director vibrations in nematic liquid crystals

abstract:
  Recently Biscari, DiCarlo and Turzi ["Anisotropic wave propagation in nematic
liquid crystals", to appear (arXiv:1311.1802)] proposed a theory for
nematoacustics which models nematic liquid crystals as nematic elastomers with
molecular relaxation. Here, we extend the analysis of this theory to account
for the director motion possibly induced by the propagation of a sound wave. We
find that the director vibration is related to the - usually small - anisotropy
of the molecular distribution, thus providing a justification to the relative
high ultrasonic intensities required to observe non-negligible acousto-optic
responses.


title:
Constraining models of $f(R)$ gravity with Planck and WiggleZ power
  spectrum data

abstract:
  In order to explain cosmic acceleration without invoking "dark" physics, we
consider $f(R)$ modified gravity models, which replace the standard
Einstein-Hilbert action in General Relativity with a higher derivative theory.
We use data from the WiggleZ Dark Energy survey to probe the formation of
structure on large scales which can place tight constraints on these models. We
combine the large-scale structure data with measurements of the cosmic
microwave background from the Planck surveyor. After parameterising the
modification of the action using the Compton wavelength parameter $B_0$, we
constrain this parameter using ISiTGR, assuming an initial non-informative log
prior probability distribution of this cross-over scale. We find that the
addition of the WiggleZ power spectrum provides the tightest constraints to
date on $B_0$ by an order of magnitude, giving ${\rm log}_{10}(B_0) < -4.07$ at
95% confidence limit. Finally, we test whether the effect of adding the lensing
amplitude $A_{\rm Lens}$ and the sum of the neutrino mass $\sum m_\nu$ is able
to reconcile current tensions present in these parameters, but find $f(R)$
gravity an inadequate explanation.


abstract:
  We study $\phi_\epsilon$-coordinated modules for vertex algebras, where
$\phi_\epsilon$ with $\epsilon$ an integer parameter is a family of associates
of the one-dimensional additive formal group. As the main results, we obtain a
Jacobi type identity and a commutator formula for $\phi_\epsilon$-coordinated
modules. We then use these results to study $\phi_\epsilon$-coordinated modules
for vertex algebras associated to Novikov algebras by Primc.


title:
De la caract\'erisation matricielle des drapeaux complets d'extensions
  riemanniennes aux feuilletages riemanniens transversalement diagonaux sur une
  vari\'et\'e compacte connexe

abstract:
  In this paper we characterise with the matrix the complete flag of riemannian
extension (see d\'efinition) on a riemannian compact manifold whose metric is
bundlelike for any foliation F_{s} of this flag. This study show us that a
foliation of a complete flag of riemannian extension on a riemannian compact
manifold whose metric is bundlelike for any foliation of this flag is a
transversely diagonal riemannian foliation (see d\'efinition).


title:
Shot noise and magnetism of Pt atomic chains: accumulation of points at
  the boundary

abstract:
  Pt is known to show spontaneous formation of monatomic chains upon breaking a
metallic contact. From model calculations, these chains are expected to be spin
polarized. However, direct experimental evidence for or against magnetism is
lacking. Here, we investigate shot noise as a potential source of information
on the magnetic state of Pt atomic chains. We observe a remarkable structure in
the distribution of measured shot-noise levels, where the data appear to be
confined to the region of nonmagnetic states. While this suggests a nonmagnetic
ground state for the Pt atomic chains, from calculations we find that the
magnetism in Pt chains is due to 'actor' electron channels, which contribute
very little to ballistic conductance and noise. On the other hand, there are
weakly polarized 'spectator' channels, which carry most of the current and are
only slightly modified by the magnetic state.


title: NLO light-cone sum rules for the nucleon electromagnetic form factors

abstract:
  We study the electromagnetic nucleon form factors within the approach based
on light-cone sum rules. We include the next-to-leading-order corrections for
the contributions of twist-three and twist-four operators and a consistent
treatment of the nucleon mass corrections in our calculation. It turns out that
a self-consistent picture arises when the three valence quarks carry
$40\%:30\%:30\%$ of the proton momentum.


title:
Engineering the Hardware/Software Interface for Robotic Platforms - A
  Comparison of Applied Model Checking with Prolog and Alloy

abstract:
  Robotic platforms serve different use cases ranging from experiments for
prototyping assistive applications up to embedded systems for realizing
cyber-physical systems in various domains. We are using 1:10 scale miniature
vehicles as a robotic platform to conduct research in the domain of
self-driving cars and collaborative vehicle fleets. Thus, experiments with
different sensors like e.g.~ultra-sonic, infrared, and rotary encoders need to
be prepared and realized using our vehicle platform. For each setup, we need to
configure the hardware/software interface board to handle all sensors and
actors. Therefore, we need to find a specific configuration setting for each
pin of the interface board that can handle our current hardware setup but which
is also flexible enough to support further sensors or actors for future use
cases. In this paper, we show how to model the domain of the configuration
space for a hardware/software interface board to enable model checking for
solving the tasks of finding any, all, and the best possible pin configuration.
We present results from a formal experiment applying the declarative languages
Alloy and Prolog to guide the process of engineering the hardware/software
interface for robotic platforms on the example of a configuration complexity up
to ten pins resulting in a configuration space greater than 14.5 million
possibilities. Our results show that our domain model in Alloy performs better
compared to Prolog to find feasible solutions for larger configurations with an
average time of 0.58s. To find the best solution, our model for Prolog performs
better taking only 1.38s for the largest desired configuration; however, this
important use case is currently not covered by the existing tools for the
hardware used as an example in this article.