pinecone/core-2020-05-10-deduplication huggingface dataset:
A Solution Merging Heuristic for the Steiner Problem in Graphs Using
  Tree Decompositions

Fixed parameter tractable algorithms for bounded treewidth are known to exist
for a wide class of graph optimization problems. While most research in this
area has been focused on exact algorithms, it is hard to find decompositions of
treewidth sufficiently small to make these al- gorithms fast enough for
practical use. Consequently, tree decomposition based algorithms have limited
applicability to large scale optimization. However, by first reducing the input
graph so that a small width tree decomposition can be found, we can harness the
power of tree decomposi- tion based techniques in a heuristic algorithm, usable
on graphs of much larger treewidth than would be tractable to solve exactly. We
propose a solution merging heuristic to the Steiner Tree Problem that applies
this idea. Standard local search heuristics provide a natural way to generate
subgraphs with lower treewidth than the original instance, and subse- quently
we extract an improved solution by solving the instance induced by this
subgraph. As such the fixed parameter tractable algorithm be- comes an
efficient tool for our solution merging heuristic. For a large class of sparse
benchmark instances the algorithm is able to find small width tree
decompositions on the union of generated solutions. Subsequently it can often
improve on the generated solutions fast
‘Inside Out’: The politics of enumerating the nation by ethnicity

Since the 1990s, state practices of counting and classifying populations by ethnicity have come under increased scrutiny within the social sciences (Arel 2002 ; Kertzer and Arel 2002 ; Nobles 2000 ; Perlmann and Waters 2002 ; Petersen 1997 ; Statistics Canada and U.S. Census Bureau 1993 ). A number of excellent case studies have provided critical insights into how and why ethnic enumeration is pursued in particular times and places. ¹ However, with some notable exceptions (Morning 2008 ; Rallu
et al. 2006 ), little attention has been given to theorizing or empirically testing a global
model of ethnic classifi cation and counting. Consequently, there is a limited understanding
about the general conditions that impede or encourage state recognition of ethnicity in the national census and the forms that such recognition takes
A Scalable, Linear-Time Dynamic Cutoff Algorithm for Molecular Dynamics

Recent results on supercomputers show that beyond 65K cores, the efficiency
of molecular dynamics simulations of interfacial systems decreases
significantly. In this paper, we introduce a dynamic cutoff method (DCM) for
interfacial systems of arbitrarily large size. The idea consists in adopting a
cutoff-based method in which the cutoff is cho- sen on a particle-by-particle
basis, according to the distance from the interface. Computationally, the
challenge is shifted from the long-range solvers to the detection of the
interfaces and to the computation of the particle-interface distances. For
these tasks, we present linear-time algorithms that do not rely on global
communication patterns. As a result, the DCM algorithm is suited for large
systems of particles and mas- sively parallel computers. To demonstrate its
potential, we integrated DCM into the LAMMPS open-source molecular dynamics
package, and simulated large liquid/vapor systems on two supercomputers:
SuperMuc and JUQUEEN. In all cases, the accuracy of DCM is comparable to the
traditional particle-particle particle-mesh (PPPM) algorithm, while the
performance is considerably superior for large numbers of particles. For
JUQUEEN, we provide timings for simulations running on the full system (458,
752 cores), and show nearly perfect strong and weak scaling.Comment: in ISC High Performance 201
Biografo: An integrated tool for forensic writer identification

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-20125-2_17The design and performance of a practical integrated tool for writer identification in forensic scenarios is presented. The tool has been designed to help forensic examiners along the complete identification process: from the data acquisition to the recognition itself, as well as with the management of large writer-related databases. The application has been implemented using JavaScript running over a relational database which provides the whole system with some very desirable and unique characteristics such as the possibility to perform all type of queries (e.g., find individuals with some very discriminative character, find a specific document, display all the samples corresponding to one writer, etc.), or a complete control over the set of parameters we want to use in a specific recognition task (e.g., users in the database to be used as control set, set of characters to be used in the identification, size of the ranked list we want as final result, etc.). The identification performance of the tool is evaluated on a real-case forensic database showing some very promising results.This work has been partially supported by the Spanish Dirección General de la Guardia Civil, and projects Contexts (S2009/TIC-1485) from CAM, Bio-Challenge (TEC2009-11186) from Spanish MICINN, BBfor2 (ITN-2008-238803) from the European Commision, and Cátedra UAM-Telefónica
A study of identification performance of facial regions from CCTV images

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-20125-2_8This paper focuses on automatic face identification for forensic applications. Forensic examiners compare different parts of the face image obtained from a closed-circuit television (CCTV) image with a database of mug shots or good quality image(s) taken from the suspect. In this work we study and compare the discriminative capabilities of different facial regions (also referred to as facial features) such as eye, eyebrow, mouth, etc. It is useful because it can statistically support the current practice of forensic facial comparison. It is also of interest to biometrics as a more robust general-purpose face recognition system can be built by fusing the similarity scores obtained from the comparison of different individual parts of the face. For experiments with automatic systems, we simulate a very challenging recognition scenario by using a database of 130 subjects each having only one gallery image. Gallery images are frontal mug shots while probe set consist of low quality CCTV camera images. Face images in gallery and probe sets are first segmented using eye locations and recognition experiments are performed for the different face regions considered. We also study and evaluate an improved recognition approach based on AdaBoost algorithm with Linear Discriminant Analysis (LDA) as a week learner and compare its performance with the baseline Eigenface method for automatic facial feature recognition.This work is carried out during the secondment of the first author at ATVS, Autonomous University of Madrid. The research is funded by the European commission as a Marie-Curie ITN-project (FP7-PEOPLE-ITN-2008) under grant agreement number 238803 and the Spanish Direccion General de la Guardia Civil (DGGC). The authors would like to thank Nicomedes Exposito, Francisco J. Vega, Patricio Leston and Pedro A. Martinez for their valuable comments
Schwinger's Quantum Action Principle: From Dirac's formulation through
  Feynman's path integrals, the Schwinger-Keldysh method, quantum field theory,
  to source theory

Starting from the earlier notions of stationary action principles, we show
how Julian Schwinger's Quantum Action Principle descended from Dirac's
formulation, which independently led Feynman to his path-integral formulation
of quantum mechanics. The connection between the two is brought out, and
applications are discussed. The Keldysh-Schwinger time-cycle method of
extracting matrix elements in nonequilibrium situations is described. The
variational formulation of quantum field theory and the development of source
theory constitute the latter part of this work. In this document, derived from
Schwinger's lectures over four decades, the continuity of concepts, such as
that of Green's functions, becomes apparent.Comment: 116 pages, submitted to SpringerBriefs. Very substantially updated
  version of 1402.3762, with new chapters on Quantum Field Theory and Source
  Theor
Deterministic Abelian Sandpile and square-triangle tilings

The Abelian Sandpile Model, seen as a deterministic lattice automaton, on
two-dimensional periodic graphs generates complex regular patterns displaying
(fractal) self-similarity. In particular, on a variety of lattices and initial
conditions, at all sizes, there appears what we call an exact Sierpinski
structure: the volume is filled with periodic patterns, glued together along
straight lines, with the topology of a triangular Sierpinski gasket. Various
lattices (square, hexagonal, kagome,...), initial conditions, and toppling
rules show Sierpinski structures which are apparently unrelated and involve
different mechanisms. As will be shown elsewhere, all these structures fall
under one roof, and are in fact different projections of a unique mechanism
pertinent to a family of deterministic surfaces in a 4-dimensional lattice.
This short note gives a description of this surface, and of the combinatorics
associated to its construction
Torsion in the homology of Milnor fibers of hyperplane arrangements

As is well-known, the homology groups of the complement of a complex
hyperplane arrangement are torsion-free. Nevertheless, as we showed in a recent
paper [arXiv:1209.3414] the homology groups of the Milnor fiber of such an
arrangement can have non-trivial integer torsion. We give here a brief account
of the techniques that go into proving this result, outline some of its
applications, and indicate some further questions that it brings to light.Comment: To appear in Combinatorial Methods in Topology and Algebra, Springer
  INdAM Series, vol. 12, 2015. arXiv admin note: text overlap with
  arXiv:1209.341
Ultrafast control of strong-field electron dynamics in solids

We review theoretical foundations and some recent progress related to the
quest of controlling the motion of charge carriers with intense laser pulses
and optical waveforms. The tools and techniques of attosecond science enable
detailed investigations of a relatively unexplored regime of nondestructive
strong-field effects. Such extremely nonlinear effects may be utilized to steer
electron motion with precisely controlled optical fields and switch electric
currents at a rate that is far beyond the capabilities of conventional
electronics.Comment: This manuscript was prepared for a book "Ultrafast Ionization
  Dynamics", which is to be published by Springe
Decision Tree-Based Multiple Classifier Systems: An FPGA Perspective

Combining a hardware approach with a multiple classifier method can deeply improve system performance, since the multiple classifier system can successfully enhance the classification accuracy with respect to a single classifier, and a hardware implementation would lead to systems able to classify samples with high throughput and with a short latency. To the best of our knowledge, no paper in the literature takes into account the multiple classifier scheme as additional design parameter, mainly because of lack of efficient hardware combiner architecture.\ud
\ud
In order to fill this gap, in this paper we will first propose a novel approach for an efficient hardware implementation of the majority voting combining rule. Then, we will illustrate a design methodology to suitably embed in a digital device a multiple classifier system having Decision Trees as base classifiers and a majority voting rule as combiner. Bagging, Boosting and Random Forests will be taken into account. We will prove the effectiveness of the proposed approach on two real case studies related to Big Data issues
Supporting cross-device web search with social navigation-based mobile touch interactions

© Springer International Publishing Switzerland 2015. The wide adoption of smartphones eliminates the time and location barriers for people’s daily information access, but also limits users’ information exploration activities due to the small mobile screen size. Thus, cross-device web search, where people initialize information needs on one device but complete them on another device, is frequently observed in modern search engines, especially for exploratory information needs. This paper aims to support the cross-device web search, on top of the commonly used context-sensitive retrieval framework, for exploratory tasks. To better model users’ search context, our method not only utilizes the search history (query history and click-through) but also employs the mobile touch interactions (MTI) on mobile devices. To be more specific, we combine MTI’s ability of locating relevant subdocument content [10] with the idea of social navigation that aggregates MTIs from other users who visit the same page. To demonstrate the effectiveness of our proposed approach, we designed a user study to collect cross-device web search logs on three different types of tasks from 24 participants and then compared our approach with two baselines: a traditional full text based relevance feedback approach and a self-MTI based subdocument relevance feedback approach. Our results show that the social navigation-based MTIs outperformed both baselines. A further analysis shows that the performance improvements are related to several factors, including the quality and quantity of click-through documents, task types and users’ search conditions
Adenosine A2A receptors: localization and function

Adenosine is an endogenous purine nucleoside present in all mammalian tissues, that originates from the breakdown of ATP. By binding to its four receptor subtypes (A1, A2A, A2B, and A3), adenosine regulates several important physiological functions at both the central and peripheral levels. Therefore, ligands for the different adenosine receptors are attracting increasing attention as new potential drugs to be used in the treatment of several diseases. This chapter is aimed at providing an overview of adenosine metabolism, adenosine receptors localization and their signal transduction pathways. Particular attention will be paid to the biochemistry and pharmacology of A2A receptors, since antagonists of these receptors have emerged as promising new drugs for the treatment of Parkinson's disease. The interactions of A2A receptors with other nonadenosinergic receptors, and the effects of the pharmacological manipulation of A2A receptors on different body organs will be discussed, together with the usefulness of A2A receptor antagonists for the treatment of Parkinson's disease and the potential adverse effects of these drugs
Editing to a planar graph of given degrees.

We consider the following graph modification problem. Let the input consist of a graph G=(V,E), a weight function w:V∪E→N, a cost function c:V∪E→N and a degree function δ:V→N0, together with three integers kv, ke and C. The question is whether we can delete a set of vertices of total weight at most kv and a set of edges of total weight at most ke so that the total cost of the deleted elements is at most C and every non-deleted vertex v has degree δ(v) in the resulting graph G′. We also consider the variant in which G′ must be connected. Both problems are known to be NP-complete and W[1]-hard when parameterized by kv+ke. We prove that, when restricted to planar graphs, they stay NP-complete but have polynomial kernels when parameterized by kv+ke
A column generation approach to the discrete lot sizing and scheduling problem on parallel machines

In this work, we study the discrete lot sizing and scheduling problem (DSLP) in identical parallel resources with (sequence-independent) setup costs and inventory holding costs. We propose a Dantzig-Wolfe decomposition of a known formulation and describe a branch-and-price and column generation procedure to solve the problem to optimality. The results show that the lower bounds provided by the reformulated model are stronger than the lower bounds provided by the linear programming (LP) relaxation of the original model.info:eu-repo/semantics/publishedVersio
Optimization clustering techniques on register unemployment data

An important strategy for data classification consists in organising data
points in clusters. The k-means is a traditional optimisation method applied to
cluster data points. Using a labour market database, aiming the segmentation of this
market taking into account the heterogeneity resulting from different unemployment
characteristics observed along the Portuguese geographical space, we suggest the
application of an alternative method based on the computation of the dominant
eigenvalue of a matrix related with the distance among data points. This approach
presents results consistent with the results obtained by the k-means.info:eu-repo/semantics/publishedVersio
Efficiency and productivity assessment of wind farms

This study develops a framework to provide insights regarding the
performance of the farms of an energy player in the Portuguese wind sector. The
focus of the wind farm performance assessment is on the operating stage which
corresponds to the electrical energy generation process, during 2010 and 2011.
In a first stage, Data Envelopment Analysis is used to measure the efficiency of
wind farms in generating electrical energy from the resources available and nondiscretionary
variables. This analysis enables the identification of the best practices
of the efficient farms which can be emulated by inefficient ones. In a second
stage, changes in wind farms productivity are investigated using Malmquist index.
Bootstrap procedures are applied to obtain statistical inference on the efficiency
estimates. We conclude that almost all farms decreased overall productivity levels,
mainly due to the decline in the productivity levels of the frontier, which is in
accordance with the decrease in wind availability observed in 2011.info:eu-repo/semantics/publishedVersio
Theoretical Pore Growth Models for Nanoporous Alumina

Nanoporous alumina has been extensively used in a wide range of applications, including template materials for various types of nanomaterials, high surface-area structures for energy conversation and storage, bio/chemo sensors, electronic/photonic devices, and so on. However, the formation mechanism of the nanopores and the subsequent pore growth process towards self-ordered pore arrangements have been under investigation for several decades without clear conclusions. The present models may be divided into two main groups in terms of the driving force for pore initialization, as well as the subsequent pore growth process. One group considers that the driving force is the high electric field across the oxide barrier layer at the bottom of the pore channels, which assists metal oxidation at the metal/oxide interface, and oxide dissolution at the oxide/electrolyte interface. The other group of models assumes that the driving force is mechanical stress originating from the volume expansion of the metal oxidation process. This chapter reviews the development of these models for nanoporous alumina formation, and discusses their advantages and shortcomings. A recent model proposed by us is also described, and potential directions for further development are discussed.postprin
On the cohomology of pseudoeffective line bundles

39 pages. This survey is a written account of a lecture given at the Abel Symposium, Trondheim, July 2013International audienceThe goal of this survey is to present various results concerning the cohomology of pseudoeffective line bundles on compact Kähler manifolds, and related properties of their multiplier ideal sheaves. In case the curvature is strictly positive, the prototype is the well known Nadel vanishing theorem, which is itself a generalized analytic version of the fundamental Kawamata-Viehweg vanishing theorem of algebraic geometry. We are interested here in the case where the curvature is merely semipositive in the sense of currents, and the base manifold is not necessarily projective. In this situation, one can still obtain interesting information on cohomology, e.g. a Hard Lefschetz theorem with pseudoeffective coefficients, in the form of a surjectivity statement for the Lefschetz map. More recently, Junyan Cao, in his PhD thesis defended in Grenoble, obtained a general Kähler vanishing theorem that depends on the concept of numerical dimension of a given pseudoeffective line bundle. The proof of these results depends in a crucial way on a general approximation result for closed (1,1)-currents, based on the use of Bergman kernels, and the related intersection theory of currents. Another important ingredient is the recent proof by Guan and Zhou of the strong openness conjecture. As an application, we discuss a structure theorem for compact Kähler threefolds without nontrivial subvarieties, following a joint work with F.Campana and M.Verbitsky. We hope that these notes will serve as a useful guide to the more detailed and more technical papers in the literature; in some cases, we provide here substantially simplified proofs and unifying viewpoints
Comparative study on efficiency of mirror retroreflectors

Here we study retroreflectors based on specular reflections. Two kinds of asymptotically perfect specular retroreflectors in two dimensions, Notched angle and Tube, are known at present. We conduct comparative study of their efficiency, assuming that the reflection coefficient is slightly less than 1. We also compare their efficiency with the one of the retroreflector Square corner (the 2D analogue of the well-known and widely used Cube corner). The study is partly analytic and partly uses numerical simulations. We conclude that the retro-reflectivity of Notched angle is normally much greater than those of Tube and the Square corner. Additionally, simple Notched angle shapes are constructed, whose efficiency is significantly higher than that of the Square corner
The alternating least-squares algorithm for CDPCA

Clustering and Disjoint Principal Component Analysis (CDP CA) is a constrained principal component analysis recently proposed for clustering of objects and partitioning of variables, simultaneously, which we have implemented in R language. In this paper, we deal in detail with the alternating least-squares algorithm for CDPCA and highlight its algebraic features for constructing both interpretable principal components and clusters of objects. Two applications are given to illustrate the capabilities of this new methodology
MEMS technologies for energy harvesting

The objective of this chapter is to introduce the technology of Microelectromechanical Systems, MEMS, and their application to emerging energy harvesting devices. The chapter begins with a general introduction to the most common MEMS fabrication processes. This is followed with a survey of design mechanisms implemented in MEMS energy harvesters to provide nonlinear mechanical actuations. Mechanisms to produce bistable potential will be studied, such as introducing fixed magnets, buckling of beams or using slightly slanted clamped-clamped beams. Other nonlinear mechanisms are studied such as impact energy transfer, or the design of nonlinear springs. Finally, due to their importance in the field of MEMS and their application to energy harvesters, an introduction to actuation using piezoelectric materials is given. Examples of energy harvesters found in the literature using this actuation principle are also presented.Postprint (author's final draft