pinecone/core-2020-05-10-deduplication huggingface dataset:
Electron spin as a spectrometer of nuclear spin noise and other
  fluctuations

This chapter describes the relationship between low frequency noise and
coherence decay of localized spins in semiconductors. Section 2 establishes a
direct relationship between an arbitrary noise spectral function and spin
coherence as measured by a number of pulse spin resonance sequences. Section 3
describes the electron-nuclear spin Hamiltonian, including isotropic and
anisotropic hyperfine interactions, inter-nuclear dipolar interactions, and the
effective Hamiltonian for nuclear-nuclear coupling mediated by the electron
spin hyperfine interaction. Section 4 describes a microscopic calculation of
the nuclear spin noise spectrum arising due to nuclear spin dipolar flip-flops
with quasiparticle broadening included. Section 5 compares our explicit
numerical results to electron spin echo decay experiments for phosphorus doped
silicon in natural and nuclear spin enriched samples.Comment: Book chapter in "Electron spin resonance and related phenomena in low
  dimensional structures", edited by Marco Fanciulli. To be published by
  Springer-Verlag in the TAP series. 35 pages, 9 figure
Quantitative Treatment of Decoherence

We outline different approaches to define and quantify decoherence. We argue
that a measure based on a properly defined norm of deviation of the density
matrix is appropriate for quantifying decoherence in quantum registers. For a
semiconductor double quantum dot qubit, evaluation of this measure is reviewed.
For a general class of decoherence processes, including those occurring in
semiconductor qubits, we argue that this measure is additive: It scales
linearly with the number of qubits.Comment: Revised version, 26 pages, in LaTeX, 3 EPS figure
Shimura curve computations via K3 surfaces of Neron-Severi rank at least 19

It is known that K3 surfaces S whose Picard number rho (= rank of the Neron-Severi group of S) is at least 19 are parametrized by modular curves X, and these modular curves X include various Shimura modular curves associated with congruence subgroups of quaternion algebras over Q. In a family of such K3 surfaces, a surface has rho=20 if and only if it corresponds to a CM point on X. We use this to compute equations for Shimura curves, natural maps between them, and CM coordinates well beyond what could be done by working with the curves directly as we did in "Shimura Curve Computations" (1998).Mathematic
Verifiable multi-secret sharing schemes for multiple threshold access structures

A multi-secret sharing scheme allows several secrets to be shared amongst a group of participants. In 2005, Shao and Cao developed a verifiable multi-secret sharing scheme where each participant’s share can be used several times which reduces the number of interactions between the dealer and the group members. In addition some secrets may require a higher security level than others involving the need for different threshold values. Recently Chan and Chang designed such a scheme but their construction only allows a single secret to be shared per threshold value.\ud
\ud
In this article we combine the previous two approaches to design a multiple time verifiable multi-secret sharing scheme where several secrets can be shared for each threshold value. Since the running time is an important factor for practical applications, we will provide a complexity comparison of our combined approach with respect to the previous schemes
Black Holes, Black Rings and their Microstates

In this review article we describe some of the recent progress towards the
construction and analysis of three-charge configurations in string theory and
supergravity. We begin by describing the Born-Infeld construction of
three-charge supertubes with two dipole charges, and then discuss the general
method of constructing three-charge solutions in five dimensions. We explain in
detail the use of these methods to construct black rings, black holes, as well
as smooth microstate geometries with black hole and black ring charges, but
with no horizon. We present arguments that many of these microstate geometries
are dual to boundary states that belong to the same sector of the D1-D5-P CFT
as the typical states. We end with an extended discussion of the implications
of this work for the physics of black holes in string theory.Comment: 96 pages, 10 figures, 17 exercises, LaTeX. Review article based on
  lectures presented at the Winter School on the Attractor Mechanism (Frascati,
  March 20-24, 2006). v2. Improved discussion of smoothness and regularity of
  microstate geometries. References adde
A Tale of Two Object Recognition Methods for Mobile Robots

This original publication is available at www.springerlink.comObject recognition is a key feature for building robots capable of moving and performing tasks in human environments. However, current object recognition research largely ignores the problems that the mobile robots context introduces. This work addresses the problem of applying these techniques to mobile robotics in a typical household scenario. We select two state-of-the-art object recognition methods, which are suitable to be adapted to mobile robots, and we evaluate them on a challenging dataset of typical household objects that caters to these requirements. The different advantages and drawbacks found for each method are highlighted, and some ideas for extending them are proposed. Evaluation is done comparing the number of detected objects and false positives for both approaches.This work has been partially funded by the FI grant and the BE grant from the AGAUR, the European Social Fund, the 2005/SGR/00093 project, supported by the Generalitat de Catalunya , the MIDCBR project grant TIN\ud
200615140C0301, TIN 200615308C0202 and FEDER funds.Peer reviewe
Automatic initialization for facial analysis in interactive robotics

The human face plays an important role in communication as it allows to discern different interaction partners and provides non-verbal feedback. In this paper, we present a soft real-time vision system that enables an interactive robot to analyze faces of interaction partners not only to identify them, but also to recognize their respective facial expressions as a dialog-controlling non-verbal cue. In order to assure applicability in real world environments, a robust detection scheme is presented which detects faces and basic facial features such as the position of the mouth, nose, and eyes. Based on these detected features, facial parameters are extracted using active appearance models (AAMs) and conveyed to support vector machine (SVM) classifiers to identify both persons and facial expressions. This paper focuses on four different initialization methods for determining the initial shape for the AAM algorithm and their particular performance in two different classification tasks with respect to either the facial expression DaFEx database and to the real world data obtained from a robot’s point of view
Distributed PLR-Based Backup Path Computation in MPLS Networks

International audienceIn this article, we provide mechanisms enabling the backup path computation to be performed on-line and locally by the Points of Local Repair (PLRs), in the context of the MPLS-TE fast reroute. To achieve a high degree of bandwidth sharing, the Backup Path Computation Entities (BPCEs), running on PLRs, require the knowledge and maintenance of a great quantity of bandwidth information (non aggre-gated link information or per path information) which is undesirable in distributed environments. To get around this problem, we propose a distributed PLR (Point of Local Repair)-based heuristic (DPLRH) which aggregates and noticeably decreases the size of the bandwidth information advertised in the network while maintaining the bandwidth sharing high. DPLRH is scalable, easy to be deployed and balances equitably computations on the network routers. Simulations show that with the transmission of a small quantity of aggregated information per link, the ratio of rejected backup paths is low and close to the ideal
Synchronization of grammars

International audienceDeterministic graph grammars are finite devices which generate the transition graphs of pushdown automata. We define the notion of synchronization by grammars, generalizing previous sub-classes such as visibly and height-deterministic pushdown automata. The languages recognized by grammars synchronized by a given grammar form an effective boolean algebra lying between regular languages and deterministic context-free languages. We also provide a sufficient condition to obtain the closure under concatenation and its iteration
On the Complexity of Membership and Counting in Height-Deterministic Pushdown Automata

The original publication is available at www.springerlink.com.International audienceWhile visibly pushdown languages properly generalise regular languages and are properly contained in deterministic context-free languages, the complexity of their membership problem is equivalent to that of regular languages. However, the corresponding counting problem could be harder than counting paths in a non-deterministic finite automaton: it is only known to be in LogDCFL. We investigate the membership and counting problems for generalisations of visibly pushdown automata, defined using the notion of height-determinism. We show that, when the stack-height of a given pda can be computed using a finite transducer, both problems have the same complexity as for visibly pushdown languages. We also show that when allowing pushdown transducers instead of finite-state ones, both problems become LogDCFL-complete; this uses the fact that pushdown transducers are sufficient to compute the stack heights of all real-time height-deterministic pushdown automata, and yields a candidate arithmetization of LogDCFL that is no harder than LogDCFL (our main result)
How many conflicts does it need to be unsatisfiable?

A pair of clauses in a CNF formula constitutes a conflict if there is a variable that occurs positively in one clause and negatively in the other. Clearly, a CNF formula has to have conflicts in order to be unsatisfiable—in fact, there have to be many conflicts, and it is the goal of this paper to quantify how many.\ud
\ud
An unsatisfiable k-CNF has at least 2^k clauses; a lower bound of 2^k for the number of conflicts follows easily. We improve on this trivial bound by showing that an unsatisfiable k-CNF formula requires Ω(2.32^k) conflicts. On the other hand there exist unsatisfiable k-CNF formulas with O((4^k(log k)^3)/k) conflicts. This improves the simple bound O(4^k) arising from the unsatisfiable k-CNF formula with the minimum number of clauses
Feature Selection with Fuzzy Decision Reducts

C. Cornelis, G. Hurtado Martin, R. Jensen and D. Slezak. Feature Selection with Fuzzy Decision Reducts. To appear in: Proceedings of the Third International Conference on Rough Sets and Knowledge Technology (RSKT08), 2008.In this paper, within the context of fuzzy rough set theory, we generalize the classical rough set framework for data-based attribute selection and reduction, based on the notion of fuzzy decision reducts. Experimental analysis confirms the potential of the approach.preprintpreprin
Ontology: Use and abuse

The final publication is available at Springer via http://dx.doi.org/110.1007/978-3-540-79860-6_2Revised Selected Papers of 5th International Workshop, AMR 2007, Paris, France, July 5-6, 2007This paper is a critical analysis of the use of ontology as an instrument to specify the semantics of a document. The paper argue that not only is a logic of the type used in ontology insufficient for such a purpose, but that the very idea that meaning is a property of a document that can be expressed and stored independently of the interpretation activity is misguided.
The paper proposes, in very general lines, a possible alternative view of meaning as modification of context and shows that many current approaches to meaning, from ontology to emergent semantics, can be seen as spacial cases of this approach, and can be analyzed from a very general theoretical framework
Calculating invariants as coreflexive bisimulations

Invariants, bisimulations and assertions are the main ingredients of coalgebra theory applied to software systems. In this paper we reduce the first to a particular case of the second and show how both together pave the way to a theory of coalgebras which regards invariant predicates as types. An outcome of such a theory is a calculus of invariants’ proof obligation discharge, a fragment of which is presented in the paper.
The approach has two main ingredients: one is that of adopting relations as “first class citizens” in a pointfree reasoning style; the other lies on a synergy found between a relational construct, Reynolds’ relation on functions involved in the abstraction theorem on parametric polymorphism and the coalgebraic account of bisimulations and invariants. This leads to an elegant proof of the equivalence between two different definitions of bisimulation found in coalgebra literature (due to B. Jacobs and Aczel & Mendler, respectively) and to their instantiation to the classical Park-Milner definition popular in process algebra.Partially supported by the Fundacao para a Ciencia e a Tecnologia, Portugal, under grant number SFRH/BD/27482/2006
A meshless technique based on integrated radial basis function networks for elliptic partial differential equations

This paper presents a meshless technique based on radial basis function networks (RBFNs) for solving Dirichlet boundary value problems governed by the Poisson and biharmonic equations. The technique employs integrated RBFNs (IRBFNs) to approximate the field variable and point collocation to discretize the PDE. The boundary conditions are incorporated into IRBFNs via integration constants, which occurs prior to the transformation of the\ud
network-weight spaces into the physical space. Several linear and nonlinear test problems are considered to demonstrate the attractiveness of the present meshless technique
Lower and upper covariance

We give a definition for lower and upper covariance in Walley's theory of imprecise probabilities (or coherent lower previsions) that is direct, i.e., does not refer to credal sets. It generalizes Walley's definition for lower and upper variance. Just like Walley's definition of lower and upper variance, our definition for lower and upper covariance is compatible with the credal set approach; i.e., we also provide a covariance envelope theorem. Our approach mirrors the one taken by Walley: we first reformulate the calculation of a covariance as an optimization problem and then generalize this optimization problem to lower and upper previsions. We also briefly discuss the still unclear meaning of lower and upper (co)variances and mention some ideas about generalizations to other central moments
Adaptive Spam Detection Inspired by a Cross-Regulation Model of Immune
  Dynamics: A Study of Concept Drift

This paper proposes a novel solution to spam detection inspired by a model of
the adaptive immune system known as the crossregulation model. We report on the
testing of a preliminary algorithm on six e-mail corpora. We also compare our
results statically and dynamically with those obtained by the Naive Bayes
classifier and another binary classification method we developed previously for
biomedical text-mining applications. We show that the cross-regulation model is
competitive against those and thus promising as a bio-inspired algorithm for
spam detection in particular, and binary classification in general
Quantum Nash Equilibria and Quantum Computing

In this paper we review our earlier work on quantum computing and the Nash
Equilibrium, in particular, tracing the history of the discovery of new Nash
Equilibria and then reviewing the ways in which quantum computing may be
expected to generate new classes of Nash equilibria. We then extend this work
through a substantive analysis of examples provided by Meyer, Flitney, Iqbal
and Weigert and Cheon and Tsutsui with respect to quantized games, quantum game
strategies and the extension of Nash Equilibrium to solvable games in Hilbert
space. Finally, we review earlier work by Sato, Taiji and Ikegami on non-linear
computation and computational classes by way of reference to coherence,
decoherence and quantum computating systems.Comment: 18 Pages, 6th International Conference on Complex Systems. Available
  from http://necsi.org/events/iccs6/papers/12dc335ba096f7ee3cf094c55489.pd
Recent developments in the constituent quark model including
  quark-antiquark pairs

We present the formalism for a new generation of unquenched quark models for
baryons in which the effects of quark-antiquark pairs (u anti-u, d anti-d and s
anti-s) are taken into account in an explicit form via a microscopic,
QCD-inspired, quark-antiquark creation mechaniscm. The present approach is an
extension of the flux-tube breaking model of Geiger and Isgur in which now the
contributions of quark-antiquark pairs an be studied for any initial baryon and
for any flavor of the q anti-q pair. It is shown that the inclusion of q anti-q
paris leads to a large contribution of orbital angular momentum to the proton
spin.Comment: 5 pages, 4 figures, 2 tables, NSTAR2007, Proceedings of the 11th
  Workshop on the Physics of Excited Nucleons, Springer, 200
Critical review of the blended learning models based on Maslow's and Vygotsky's educational theory

Blended learning involves the combination of two fields of concern:
education and educational technology. To gain the scholarly recognition from
educationists, it is necessary to revisit its models and educational theory
underpinned. This paper respond to this issue by reviewing models related to
blended learning based on two prominent educational theorists, Maslow’s and
Vygotsky’s view. Four models were chosen due to their holistic ideas or vast
citations related to blended learning: (1) E-Moderation Model emerging from
Open University of UK; (2) Learning Ecology Model by Sun Microsoft System;
(3) Blended Learning Continuum in University of Glamorgan; and (4) Inquirybased
Framework by Garrison and Vaughan. The discussion of each model
concerning pedagogical impact to learning and teaching are made. Critical
review of the models in accordance to Maslow or Vygotsky is argued. Such
review is concluded with several key principles for the design and practice in blended learning
Modelling the aerodynamics of coaxial helicopters : from an isolated rotor to a complete aircraft

This paper provides an overview of recent research on the aerodynamics of coaxial rotors at the Rotorcraft Aeromechanics Laboratory of the Glasgow University Rotorcraft Laboratories. The Laboratory's comprehensive rotorcraft code, known as the Vorticity Transport Model, has been used to study the aerodynamics of various coaxial rotor systems. Modelled coaxial rotor systems have ranged from a relatively simple twin two-bladed teetering configuration to a generic coaxial helicopter with a stiff main rotor system, a tail-mounted propulsor, and a horizontal stabiliser. Various studies have been performed to investigate the ability of the Vorticity Transport Model to reproduce the detailed effect of the rotor wake on the aerodynamics and performance of coaxial systems, and its ability to capture the aerodynamic interactions that arise between the various components of realistic, complex, coaxial helicopter configurations. It is suggested that the use of such a numerical technique not only allows insight into the performance of such rotor systems but might also eventually allow the various aeromechanical problems that often beset new helicopter designs of this type to be circumvented at an early stage in their design
Mobile payment: towards a customer-centric model

Mobile payment normally occurs as a wireless transaction of monetary value and includes the initiation, authorization and the realization of the payment. Such transactions are facilitated by purpose-built mobile payment systems that are part of the service infrastructure supporting the functioning of mobile business applications. A number of stakeholder groups may be involved in concluding a mobile payment transaction, among them customers, mobile operators, financial institutions, merchants, and intermediaries. In this paper, mobile payment systems are characterised from the point of view of the stakeholder groups. Building on existing work, a supply and demand model for the investigation of mPayment services is presented, and applied to a case study
Managing benefits in the public pector. Surveying expectations and outcomes in Norwegian government agencies

Published version of a chapter in Lecture Notes in Computer Science, 5184, 98-110. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-540-85204-9_9Government agencies currently experience increasing pressure to document benefits from spending on eGovernment efforts. Hence, structured methods for benefits management (BM) are being developed. However, hardly any studies have investigated how such approaches are used and experienced. This study addresses this practice-research gap by reporting a study of a project involving 30 Norwegian government agencies using a common BM approach.A questionnaire was answered by project managers. Results show that that some 80 % of the managers considered their early quantifications of expected benefits to be realistic. Further, the managers found the approach useful. They felt projects became more focused, and expect to continue working with a BM approach. While the benefits that were identified and quantified in the reported projects represent estimates and not measurements, this study shows that BM can be useful – and even welcomed – in eGovernment projects and that demonstrating benefits from such projects can be accomplished
VPOET: Using a distributed collaborative platform for Semantic Web applications

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-540-85257-5_17Proceedings of the 2nd International Symposium on Intelligent Distributed Computing – IDC 2008, Catania, Italy, 2008This paper describes a distributed collaborative wiki-based platform that has been designed to facilitate the development of Semantic Web applications. The applications designed using this platform are able to build semantic data through the cooperation of different developers and to exploit that semantic data. The paper shows a practical case study on the application VPOET, and how an application based on Google Gadgets has been designed to test VPOET and let human users exploit the semantic data created. This practical example can be used to show how different Semantic Web technologies can be integrated into a particular Web application, and how the knowledge can be cooperatively improved.This  work  has  been  supported  by  TIN  2005-06885,  TIN  2007-64718  and  TIN
2007-65989
Numerical approximation of partial differential equations

This is the softcover reprint of the very popular hardcover edition. This book deals with the numerical approximation of partial differential equations. Its scope is to provide a thorough illustration of numerical methods, carry out their stability and convergence analysis, derive error bounds, and discuss the algorithmic aspects relative to their implementation. A sound balancing of theoretical analysis, description of algorithms and discussion of applications is one of its main features. Many kinds of problems are addressed. A comprehensive theory of Galerkin method and its variants, as wel
Searching for Temporal Patterns in AmI Sensor Data

International audienceData streams emanating from sensors in AmI scenarios often exhibit interesting temporal patterns that point to semantically meaningful events. In this paper we explore two methodologies to uncover this hidden temporal structure: compression-based pattern extractors utilize temporal ordering whereas T-patterns attempt to include estimates for the inter-event times. We suggest improvements to simplify the statistical underpinnings of T-patterns and discuss the relative merits of both methodologies in the light of a number of simulation experiments