pinecone/core-2020-05-10-deduplication huggingface dataset:
Spacetime metric from local and linear electrodynamics: a new axiomatic
  scheme

We consider spacetime to be a 4-dimensional differentiable manifold that can
be split locally into time and space. No metric, no linear connection are
assumed. Matter is described by classical fields/fluids. We distinguish
electrically charged from neutral matter. Electric charge and magnetic flux are
postulated to be conserved. As a consequence, the inhomogeneous and the
homogeneous Maxwell equations emerge expressed in terms of the excitation H and
the field strength F, respectively. H and F are assumed to fulfill a local and
linear "spacetime relation" with 36 constitutive functions. The propagation of
electromagnetic waves is considered under such circumstances in the geometric
optics limit. We forbid birefringence in vacuum and find the light cone
including its Lorentzian signature. Thus the conformally invariant part of the
metric is recovered. If one sets a scale, one finds the pseudo-Riemannian
metric of spacetime.Comment: Latex, 27 pages, 8 eps figures (better quality files are available
  from the authors). Invited lecture, 339th WE Heraeus Seminar on Special
  Relativity, Potsdam, Germany, 13-18 February 2005, To be published in the
  Proceeding
Overview of the SME: Implications and Phenomenology of Lorentz Violation

The Standard Model Extension (SME) provides the most general
observer-independent field theoretical framework for investigations of Lorentz
violation. The SME lagrangian by definition contains all Lorentz-violating
interaction terms that can be written as observer scalars and that involve
particle fields in the Standard Model and gravitational fields in a generalized
theory of gravity. This includes all possible terms that could arise from a
process of spontaneous Lorentz violation in the context of a more fundamental
theory, as well as terms that explicitly break Lorentz symmetry. An overview of
the SME is presented, including its motivations and construction. Some of the
theoretical issues arising in the case of spontaneous Lorentz violation are
discussed, including the question of what happens to the Nambu-Goldstone modes
when Lorentz symmetry is spontaneously violated and whether a Higgs mechanism
can occur. A minimal version of the SME in flat Minkowski spacetime that
maintains gauge invariance and power-counting renormalizability is used to
search for leading-order signals of Lorentz violation. Recent Lorentz tests in
QED systems are examined, including experiments with photons, particle and
atomic experiments, proposed experiments in space and experiments with a
spin-polarized torsion pendulum.Comment: 40 pages, Talk presented at Special Relativity: Will it Survive the
  Next 100 Years? Potsdam, Germany, February, 200
Optimal Release Policy for Prophylactic Biological Control

International audienceIn this paper, we study the prophylactic biological control strategy for greenhouse crops protection. The method consists in the preventive installation of natural enemies to fight against an invading pest, using discrete augmentative (i.e. inondative) releases of the natural enemies. We consider a simple non negative prey (pest) -predator (natural enemy) model in ordinary differential equations together with discrete augmentation of the predator population at constant frequency. As-suming we have a fixed budget to spend in natural enemies releases per time unit, we show the stability and efficiency of the prophylactic biological control strategy (i.e. the pest is eradicated) if this budget is larger than some value. Then we show that the optimal strategy to minimize worst case damage is to use the most frequent (and thus smallest) releases
Slow Manifold of a Neuronal Bursting Model

Comparing neuronal bursting models (NBM) with slow-fast autonomous dynamical
systems (S-FADS), it appears that the specific features of a (NBM) do not allow
a determination of the analytical slow manifold equation with the singular
approximation method. So, a new approach based on Differential Geometry,
generally used for (S-FADS), is proposed. Adapted to (NBM), this new method
provides three equivalent manners of determination of the analytical slow
manifold equation. Application is made for the three-variables model of
neuronal bursting elaborated by Hindmarsh and Rose which is one of the most
used mathematical representation of the widespread phenomenon of oscillatory
burst discharges that occur in real neuronal cells.Comment: arXiv admin note: text overlap with arXiv:1408.171
Computability Logic: a formal theory of interaction

Computability logic is a formal theory of (interactive) computability in the
same sense as classical logic is a formal theory of truth. This approach was
initiated very recently in "Introduction to computability logic" (Annals of
Pure and Applied Logic 123 (2003), pp.1-99). The present paper reintroduces
computability logic in a more compact and less technical way. It is written in
a semitutorial style with a general computer science, logic or mathematics
audience in mind. An Internet source on the subject is available at
http://www.cis.upenn.edu/~giorgi/cl.html, and additional material at
http://www.csc.villanova.edu/~japaridz/CL/gsoll.html
Reaction kinetics of coarse-grained equilibrium polymers: a Brownian
  Dynamics study

Self-assembled linear structures like giant cylindrical micelles or discotic
molecules in solution stacked in flexible columns are systems reminiscent of
polydisperse polymer solutions.These supramolecular polymers have an
equilibrium length distribution, the result of a competition between the random
breakage of chains and the fusion of chains to generate longer ones. In the
present work, we review the basic theoretical concepts of these ``equilibrium
polymers" and some of the important results obtained by simulation approaches.
We propose a new version of a mesoscopic model in continuous space based on the
bead and FENE spring polymer model which is treated by Brownian Dynamics and
Monte-Carlo binding/unbinding reversible changes for adjacent monomers in
space, characterized by an attempt frequency parameter. For a dilute and a
moderately semi-dilute state-points which both correspond to dynamically
unentangled regimes, the dynamic properties are found to depend upon $\omega$
through the effective life time $\tau_b$ of the average size chain which, in
turn, yields the kinetic reaction coefficients of the mean-field kinetic model
proposed by Cates. Simple kinetic theories seem to work for times $ t \geq
\tau_b$ while at shorter time, strong dynamical correlation effects are
observed.Comment: 17 figures; Lecture notes in Physics, Springer, to be publishe
A formal metamodeling approach to a transformation between the UML state machine and object-z

A significant problem with currently suggested approaches for transforming between models in different languages is that the transformation is often described imprecisely, with the result that the overall transformation task may be imprecise, incomplete and inconsistent. This paper presents a formal metamodeling approach for transforming between UML and Object-Z. In the paper, the two languages are defined in terms of their formal metamodels, and a systematic transformation between the models is provided at the meta-level in terms of formal mapping functions. As a consequence, we can provide a precise, consistent and complete transformation between them
Use of logic to describe enhanced communications services

New functionality is added to telecommunications systems in the form of features or services. However, this is a very provider-centric approach, not giving much control to the user. We consider a logic that allows the user to express preferences as to how they wish calls to be handled. This logic is encapsulated in a user-friendly policy description language. The transferability of a policy description language (Ponder) developed for system management and access control is discussed.Peer-reviewedPost-print22nd International Conference on Formal Techniques for Networked and Distributed Systems, Houston, Texas, 11-14 November 2002
Simple and Efficient Bilayer Cross Counting

We consider the problem of counting the interior edge crossings when a bipartite graph G=(V,E) with node set V and edge set E is drawn such that the nodes of the two shores of the bipartition are on two parallel lines and the edges are straight lines. The efficient solution of this problem is important in layered graph drawing.Our main observation is that it can be reduced to counting the inversions of a certain sequence. This leads to an O(|E|+|C|) algorithm, where C denotes the set of pairwise interior edge crossings, as well as to a simple O(|E|log|V_{m small}|) algorithm, where V_{m small} is the smaller cardinality node set in the bipartition of the node set |V| of the graph. We present the algorithms and the results of computational experiments with these and other algorithms on a large collection of instances
IDS interoperability and correlation using IDMEF and commodity systems

Over the past decade Intrusion Detection Systems (IDS) have been steadily improving their efficiency and effectiveness in detecting attacks. This is particularly true with signature-based IDS due to progress in attack analysis and attack signature specification. At the same time system complexity, overall numbers of bugs and security vulnerabilities have increased. This has led to the recognition that in order to operate over the entire attack space, multiple IDS must be used, which need to interoperate with one another, and possibly also with other components of system security. This paper describes an experiment in IDS interoperation using the Intrusion Detection Message Exchange Format for the purpose of correlation analysis and in order to identify and address the problems associated with the effective use and management of multiple IDS. A study of the process of intrusion analysis demonstrates the benefits of multi-IDS interoperation and cooperation, as well as the significant benefits provided by alert analysis using a central relational database
Active Network Approach to Support Multimedia Relays

Proceedings of Joint International Workshops on Interactive Distributed Multimedia Systems and Protocols for Multimedia Systems, IDMS/PROMS 2002 Coimbra, Portugal, November 26-29, 2002.This paper summarizes a pragmatic technical approach to
active networks that supports prototyping of multimedia transport protocols.
One of the targets of the architecture defined is the extension
of the processing capabilities of existing routers trying to keep up the
forwarding performance of regular packets. This work presents practical
results obtained from the development of a Java execution environment
based on the design principles presented and proposes a method for the
transparent deployment of multimedia relays over a source-destination
path, tested in several experiments
Avoiding DAD for Improving Real-Time Communication in MIPv6 Environments

Joint International Workshops on Interactive Distributed Multimedia Systems and Protocols for Multimedia Systems, IDMS/PROMS 2002 Coimbra, Portugal, November 26–29, 2002 ProceedingsCurrent specification of address configuration mandates the execution of the Duplicate Address Detection (DAD) mechanism to prevent address duplication. However, a proper support for real time multimedia applications in mobile IPv6 nodes is undermined by the disruption imposed by DAD. In order to overcome this limitation, the usage of randomly generated IPv6 Interface Identifiers without previously performing DAD is proposed, based on the statistic uniqueness of the addresses generated through this method. The address duplication risk is quantified through the calculation of the probability of an Interface Identifier collision among the nodes sharing a link. The calculated probability is deemed to be negligible compared to other causes of communication failure, such as network outages.This research was supported by the LONG (Laboratories Over Next Generation Networks) project IST-1999-20393 and Moby Dick (Mobility and Differentiated Services in a Future IP Network) project IST-2000-25394
A comparison and a combination of SST and AGM algorithms for counting points of elliptic curves in characteristic 2

International audienceSince the first use of a p-adic method for counting points of elliptic curves, by Satoh in 1999, several variants of his algorithm have been proposed. In the current state, the AGM algorithm, proposed by Mestre is thought to be the fastest in practice, and the algorithm by Satoh­-Skjernaa­-Taguchi has the best asymptotic complexity but requires precomputations. We present an amelioration of the SST algorithm, borrowing ideas from the AGM. We make a precise comparison between this modified SST algorithm and the AGM, thus demonstrating that the former is faster by a significant factor, even for small cryptographic sizes
Towards Fewer Parameters for SAT Clause Weighting Algorithms

Considerable progress has recently been made in using clause weighting algorithms such as DLM and SDF to solve SAT benchmark problems. While these algorithms have outperformed earlier stochastic techniques on many larger problems, this improvement has been bought at the cost of extra parameters and the complexity of fine tuning these parameters to obtain optimal run-time performance. This paper examines the use of parameters, specifically in relation to DLM, to identify underlying features in clause weighting that can be used to eliminate or predict workable parameter settings. To this end we propose and empirically evaluate a simplified clause weighting algorithm that replaces the tabu list and flat moves parameter used in DLM. From this we show that our simplified clause weighting algorithm is competitive with DLM on the four categories of SAT problem for whichDLMhas already been optimised.Griffith Sciences, School of Information and Communication TechnologyFull Tex
An Investigation of Variable Relationships in 3-SAT problems

To date, several types of structure for finite Constraint Satisfaction Problems have been investigated with the goal of either improving the performance of problem solvers or allowing efficient problem solvers to be identified. Our aim is to extend the work in this area by performing a structural analysis in terms of variable connectivity for 3-SAT problems. Initially structure is defined in terms of the compactness of variable connectivity for a problem. Using an easily calculable statistic developed to measure this compactness, a test was then created for identifying 3-SAT problems as either compact, loose or unstructured (or uniform). A problem generator was constructed for generating 3-SAT problems with varying degrees of structure. Using problems from this problem generator and existing problems from SATLIB, we investigated the effects of this type of structure on satisfiability and solvability of 3-SAT problems. For the same problem length, it is demonstrated that satisfiability and solvability are different for structured and uniform problems generated by the problem generator.Griffith Sciences, School of Information and Communication TechnologyFull Tex
The Use of Patterns in Service Composition

E-services are services that can be invoked over the Internet. One likely use of e-services would be to build business applications that can employ e-services from different service providers. This potential use of composite services in business settings highlights the issues of payment mechanisms, reliability, trust, inter-operability and service guarantees between different service providers. It also becomes essential to choose e-services that best fulfil the requirements of a particular business application. We investigate how patterns can be used in service composition to help in the development of business applications based on e-services
ROSA: Realistic Open Security Architecture for active networks

Proceedings of IFIP-TC6 4th International Working Conference, IWAN 2002 Zurich, Switzerland, December 4–6, 2002.Active network technology enables fast deployment of new network
services tailored to the specific needs of end users, among other features.
Nevertheless, security is still a main concern when considering the industrial
adoption of this technology. In this article we describe an open security
architecture for active network platforms that follow the discrete approach. The
proposed solution provides all the required security features, and it also grants
proper scalability of the overall system, by using a distributed key-generation
algorithm. The performance of the proposal is validated with experimental data
obtained from a prototype implementation of the solution.Publicad
Statistical mechanics

The completely revised new edition of the classical book on Statistical Mechanics covers the basic concepts of equilibrium and non-equilibrium statistical physics. In addition to a deductive approach to equilibrium statistics and thermodynamics based on a single hypothesis - the form of the microcanonical density matrix - this book treats the most important elements of non-equilibrium phenomena. Intermediate calculations are presented in complete detail. Problems at the end of each chapter help students to consolidate their understanding of the material. Beyond the fundamentals, this text demonstrates the breadth of the field and its great variety of applications. Modern areas such as renormalization group theory, percolation, stochastic equations of motion and their applications to critical dynamics, kinetic theories, as well as fundamental considerations of irreversibility, are discussed. The text will be useful for advanced students of physics and other natural sciences; a basic knowledge of quantum mechanics is presumed
2-D wavelet transform enhancement on general-purpose microprocessors: memory hierarchy and SIMD parallelism exploitation

This paper addresses the implementation of a 2-D Discrete Wavelet Transform on general-purpose microprocessors, focusing on both memory hierarchy and SIMD parallelization issues. Both topics are somewhat related, since SIMD extensions are only useful if the memory hierarchy is efficiently exploited. In this work, locality has been significantly improved by means of a novel approach called pipelined computation, which complements previous techniques based on loop tiling and non-linear layouts. As experimental platforms we have employed a Pentium-III (P-III) and a Pentium-4 (P-4) microprocessor. However, our SIMD-oriented tuning has been exclusively performed at source code level. Basically, we have reordered some loops and introduced some modifications that allow automatic vectorization. Taking into account the abstraction level at which the optimizations are carried out, the speedups obtained on the investigated platforms are quite satisfactory, even though further improvement can be obtained by dropping the level of abstraction (compiler intrinsics or assembly code)
Price-Based Information Certificates for Minimal-Revelation Combinatorial Auctions

The equilibrium of the direct-revelation Vickrey-Clarke- Groves (VCG) mechanism for combinatorial auctions requires every agent to provide complete information about its preferences. Not only is this unreasonable in settings with costly preference evaluation, but moreover it is often possible to implement the same outcome with incomplete preference information. We formalize the problem of minimal-revelation mechanism design and introduce the concept of minimal information certificates. Linear programming duality theory proves that a class of price-based information certificates are both necessary and sufficient to compute an efficient allocation in a dominant strategy mechanism.Engineering and Applied Science
Architectural support for Global Smart Spaces

This work was supported by EPSRC grant GR/M78403/GR/M76225, “Supporting Internet Computation in Arbitrary Geographical Locations”.A GLObal Smart Space (GLOSS) provides support for interaction amongst people, artefacts and places while taking account of both context and movement on a global scale. Crucial to the definition of a GLOSS is the provision of a set of location-aware services that detect, convey, store and exploit location information. We use one of these services, hearsay, to illustrate the implementation dimensions of a GLOSS. The focus of the paper is on both local and global software architecture to support the implementation of such services. The local architecture is based on XML,pipelines and is used to construct location-aware components. The global architecture is based on a hybrid peer-to-peer routing scheme and provides the local architectures with the means to communicate in the global context.Postprin
Efficient software implementation of AES on 32-bit platforms

Rijndael is the winner algorithm of the AES contest; therefore it should become the most used symmetric-key cryptographic algorithm. One important application of this new standard is cryptography on smart cards. In this paper we present an optimisation of the Rijndael algorithm to speed up execution on 32-bits processors with memory constraints, such as those used in smart cards. First a theoretical analysis of the Rijndael algorithm and of the proposed optimisation is discussed, and then simulation results of the optimised algorithm on different processors are presented and compared with other reference implementations, as known from the technical literature
An Improved Pseudorandom Generator Based on Hardness of Factoring

We present a simple to implement and efficient pseudorandom generator based on the factoring assumption. It outputs more than pn/2 pseudorandom bits per p exponentiations, each with the same base and an exponent shorter than n/2 bits. Our generator is based on results by Hastad, Schrift and Shamir
[HSS93], but unlike their generator and its improvement by Goldreich and Rosen [GR00], it does not use hashing or extractors, and is thus simpler and somewhat more efficient.

In addition, we present a general technique that can be used to speed up pseudorandom generators based on iterating one-way permutations. We construct our generator by applying this technique to results of [HSS93]. We also show how the generator given by Gennaro [Gen00] can be simply derived from results of Patel and Sundaram [PS98a] using our technique.Engineering and Applied Science
Compact representation of knowledge bases in ILP

Many inductive systems, including ILP systems, learn from a knowledge base that is structured around examples. In practical situations this example-centered representation can cause a lot of redundancy. For instance, when learning from episodes (e.g. from games), the knowledge base contains consecutive states of a world. Each state is usually described completely even though consecutive states may differ only slightly. Similar redundancies occur when the knowledge base stores examples that share common structures (e.g. when representing complex objects as machines or molecules). These two types of redundancies can place a heavy burden on memory resources. In this paper we propose a method for representing knowledge bases in a more efficient way. This is accomplished by building a graph that implicitly defines examples in terms of other structures. We evaluate our method in the context of learning a Go heuristic.status: publishe
Solving order constraints in logarithmic space.

We combine methods of order theory, finite model theory, and universal algebra to study, within the constraint satisfaction framework, the complexity of some well-known combinatorial problems connected with a finite poset. We identify some conditions on a poset which guarantee solvability of the problems in (deterministic, symmetric, or non-deterministic) logarithmic space. On the example of order constraints we study how a certain algebraic invariance property is related to solvability of a constraint satisfaction problem in non-deterministic logarithmic space