Search

1 online ID: 766 Bibliographic Level Mode of Issuance: Monograph Includes bibliographical references and index. Also issued online. Electronic reproduction. Berlin : Springer-Verlag, 2004. Mode of access: World Wide Web. System requirements: Adobe Acrobat Reader or other PDF reader (latest version recommended) Internet Explorer or other browser (latest version recommended). Title from title screen. Mode of access: World Wide Web. English Contents: EU Funded Grid Development in Europe -- Pegasus: Mapping Scientific Workflows onto the Grid -- A Low-Cost Rescheduling Policy for Dependent Tasks on Grid Computing Systems -- An Advanced Architecture for a Commercial Grid Infrastructure -- Managing MPI Applications in Grid Environments -- Flood Forecasting in CrossGrid Project -- MPICH-G2 Implementation of an Interactive Artificial Neural Network Training -- OpenMolGRID, a GRID Based System for Solving Large-Scale Drug Design Problems -- Integration of Blood Flow Visualization on the Grid: The FlowFish/GVK Approach -- A Migration Framework for Executing Parallel Programs in the Grid -- Implementations of a Service-Oriented Architecture on Top of Jini, JXTA and OGSI -- Dependable Global Computing with JaWS++ -- Connecting Condor Pools into Computational Grids by Jini -- Overview of an Architecture Enabling Grid Based Application Service Provision -- A Grid-Enabled Adaptive Problem Solving Environment -- Workflow Support for Complex Grid Applications: Integrated and Portal Solutions -- Debugging MPI Grid Applications Using Net-dbx -- Towards an UML Based Graphical Representation of Grid Workflow Applications -- Support for User-Defined Metrics in the Online Performance Analysis Tool G-PM -- Software Engineering in the EU CrossGrid Project -- Monitoring Message-Passing Parallel Applications in the Grid with GRM and Mercury Monitor -- Lhcmaster – A System for Storage and Analysis of Data Coming from the ATLAS Simulations -- Using Global Snapshots to Access Data Streams on the Grid -- SCALEA-G: A Unified Monitoring and Performance Analysis System for the Grid -- Application Monitoring in CrossGrid and Other Grid Projects -- Grid Infrastructure Monitoring as Reliable Information Service -- Towards a Protocol for the Attachment of Semantic Descriptions to Grid Services -- Semantic Matching of Grid Resource Descriptions -- Enabling Knowledge Discovery Services on Grids -- A Grid Service Framework for Metadata Management in Self-e-Learning Networks. Summary: The 2nd European AcrossGrids Conference (AxGrids 2004) aimed to examine the state ofthe artinresearchandtechnologydevelopmentsinGridComputing, and provide a forum for the presentation and exchange of views on the latest grid-related research results and future work. The conference was organized by CrossGrid, a European Union-funded project on Grid research, GRIDSTART, the EU-sponsored initiative for consolidating technical advances in grids in - rope, and the University of Cyprus. It continued on from the successful 1st European Across Grids Conference, held in Santiago de Compostela, Spain, in February 2003. AxGrids 2004 was run in conjunction with the 2nd IST Conc- tation Meeting on Grid Research, which brought together representatives from allEU-funded projectsonGridresearchforanexchangeofexperiencesandideas regarding recent developments in European grid research. TheconferencewashostedinNicosia,thecapitalofCyprus,andattracted- thorsandattendeesfromalloverEurope,theUSA,andEastAsia. TheProgram Committee of the conference consisted of 37 people from both academia and - dustry, and there were 13 external reviewers. Overall, AxGrids 2004 attracted 57 paper submissions (42 full papers and 15 short posters). Papers underwent a thorough review by several Program Committee members and external - viewers. After the review, the Program Chair decided to accept 26 papers (out of 42) for regular presentations, 8 papers for short presentations, and 13 - pers for poster presentations. Accepted papers underwent a second review for inclusion this postproceedings volume, published as part of Springer’s Lecture Notes in Computer Science series.

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-34176-2_5, Revised Selected and Invited Papers, 4th International Symposium, AGTIVE 2011, Budapest, Hungary, October 4-7, 2011, Model-Driven Engineering promotes models as the principal artefacts of the development, hence model transformation techniques – like graph transformation – become key enablers for this development paradigm. In order to increase the adoption of Model-Driven Engineering in industrial practice, techniques aimed at raising the quality and productivity in model transformation development are needed. In this paper we bring elements from generic programming into graph transformation in order to define generic graph transformations that can be reused in different contexts. In particular, we propose the definition and instantiation of graph transformation templates whose requirements from generic types are specified through so-called concepts, as well as mixin layers that extend meta-models with the extra auxiliary elements needed by templates., Work funded by the Spanish Ministry of Economy and Competitivity (project TIN2011-24139) and the Region of Madrid (project S2009/TIC-1650)

We present a new classification system based on Evolutionary Algorithm (EA), OBLIC. This tool is an OBLIque Classification system whose function is to induce a set of classification rules no hierarchical from a database or training set. The core of the algorithm is a EA with real-coded and Pittsburgh approach. Each individual is composed by a no fixed classification rules set what split in regions the search space. The fitness of each classification is obtained by means of the exploration of these regions. The result of the tool is the best classification obtained in the evolutionary process.This paper describe and analyze this new method by comparing with other classification systems on UCI Repository databases. We conclude this paper with some observations and future projects.

Non-malleable codes, defined by Dziembowski, Pietrzak, and Wichs (ICS ’10), provide roughly the following guarantee: if a codeword $c$ encoding some message $x$ is tampered to $c' = f(c)$ such that $c' \neq c$ , then the tampered message $x'$ contained in $c'$ reveals no information about $x$ . The non-malleable codes have applications to immunizing cryptosystems against tampering attacks and related-key attacks. One cannot have an efficient non-malleable code that protects against all efficient tampering functions $f$ . However, in this paper we show “the next best thing”: for any polynomial bound $s$ given a-priori, there is an efficient non-malleable code that protects against all tampering functions $f$ computable by a circuit of size $s$ . More generally, for any family of tampering functions $ \mathcal {F}$ of size $| \mathcal {F}| \leq 2^{s}$ , there is an efficient non-malleable code that protects against all $f \in \mathcal {F} $ . The rate of our codes, defined as the ratio of message to codeword size, approaches 1. Our results are information-theoretic and our main proof technique relies on a careful probabilistic method argument using limited independence. As a result, we get an efficiently samplable family of efficient codes, such that a random member of the family is non-malleable with overwhelming probability. Alternatively, we can view the result as providing an efficient non-malleable code in the “common reference string” model. We also introduce a new notion of non-malleable key derivation, which uses randomness $x$ to derive a secret key $y = h(x)$ in such a way that, even if $x$ is tampered to a different value $x' = f(x)$ , the derived key $y' = h(x')$ does not reveal any information about $y$ . Our results for non-malleable key derivation are analogous to those for non-malleable codes. As a useful tool in our analysis, we rely on the notion of “leakage-resilient storage” of Davi, Dziembowski, and Venturi (SCN ’10), and, as a result of independent interest, we also significantly improve on the parameters of such schemes.

Date du colloque: 01/2012; International audience; This paper investigates the adaptive selection of operators in the context of Local Search. The utility of each operator is computed from the solution quality and distance of the candidate solution from the search trajectory. A number of utility measures based on the Pareto dominance relationship and the relative distances between the operators are proposed and evaluated on QAP instances using an implied or static target balance between exploitation and exploration. A refined algorithm with an adaptive target balance is then examined.

Date du colloque: 06/2012; International audience; The unconstrained binary quadratic programming (UBQP) problem is a general NP-hard problem with various applications. In this paper, we present a multilevel algorithm designed to approximate large UBQP instances. The proposed multilevel algorithm is composed of a backbone-based coarsening phase, an asymmetric uncoarsening phase and a memetic refinement phase, where the backbone-based procedure and the memetic refinement procedure make use of tabu search to obtain improved solutions. Evaluated on a set of 11 largest instances from the literature (with 5000 to 7000 variables), the proposed algorithm proves to be able to attain all the best known values with a computing effort less than any existing approach.

Emerging MPI libraries, such as VolpexMPI and P2P MPI, allow message passing parallel programs to execute effectively in heterogeneous volunteer environments despite frequent failures. However, the performance of message passing codes varies widely in a volunteer environment, depending on the application characteristics and the computation and communication characteristics of the nodes and the interconnection network. This paper has the dual goal of developing and validating a tool chain to estimate performance of MPI codes in a volunteer environment and analyzing the suitability of the class of computations represented by NAS benchmarks for volunteer computing. The framework is deployed to estimate performance in a variety of possible volunteer configurations, including some based on the measured parameters of a campus volunteer pool. The results show slowdowns by factors between 2 and 10 for different NAS benchmark codes for execution on a realistic volunteer campus pool as compared to dedicated clusters.

Date du colloque: 09/2012; International audience; The max-cut problem is to partition the vertices of a weighted graph G = (V,E) into two subsets such that the weight sum of the edges crossing the two subsets is maximized. This paper presents a memetic max-cut algorithm (MACUT) that relies on a dedicated multi-parent crossover operator and a perturbation-based tabu search procedure. Experiments on 30 G-set benchmark instances show that MACUT competes favorably with 6 state-of-the-art max-cut algorithms, and for 10 instances improves on the best known results ever reported in the literature.

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-15928-2_18, Proceedings of 5th International Conference, ICGT 2010, Enschede, The Netherlands, September 27–October 2, 2010, Graph transformation is being increasingly used to express the semantics of domain specific visual languages since its graphical nature makes rules intuitive. However, many application domains require an explicit handling of time in order to represent accurately the behaviour of the real system and to obtain useful simulation metrics. Inspired by the vast knowledge and experience accumulated by the discrete event simulation community, we propose a novel way of adding explicit time to graph transformation rules. In particular, we take the event scheduling discrete simulation world view and incorporate to the rules the ability of scheduling the occurrence of other rules in the future. Hence, our work combines standard, efficient techniques for discrete event simulation (based on the handling of a future event set) and the intuitive, visual nature of graph transformation. Moreover, we show how our formalism can be used to give semantics to other timed approaches., Work partially sponsored by the Spanish Ministry of Science and Innovation, under project “METEORIC” (TIN2008-02081) and mobility grants JC2009-00015 and PR2009-0019, as well as by the R&D programme of the Community of Madrid, project “e-Madrid” (S2009/TIC-1650). We are grateful to the anonymous reviewers, which helped in improving the paper

Membrane Computing is a new paradigm inspired from cellular communication. Until now, P systems have been used in research areas like modeling chemical process, several ecosystems, etc. In this paper, we apply P systems to Computational Topology within the context of the Digital Image. We work with a variant of P systems called tissue-like P systems to calculate in a general maximally parallel manner the homology groups of 2D images. In fact, homology computation for binary pixel-based 2D digital images can be reduced to connected component labeling of white and black regions. Finally, we use a software called Tissue Simulator to show with some examples how these systems work.

Date du colloque: 04/2009; International audience; This paper introduces a new tabu search algorithm for a two-dimensional (2D) Strip Packing Problem (2D-SPP). It integrates several key features: A direct representation of the problem, a satisfaction-based solving scheme, two different complementary neighborhoods, a diversification mechanism and a particular tabu structure. The representation allows inexpensive basic operations. The solving scheme considers the 2D-SPP as a succession of satisfaction problems. The goal of the combination of two neighborhoods is (to try) to reduce the height of the packing while avoiding solutions with (hard to fill) tall and thin wasted spaces. Diversification relies on a set of historically “interesting” packings. The tabu structure avoids visiting similar packings. To assess the proposed approach, experimental results are shown on a set of well-known benchmark instances and compared with previously reported tabu search algorithms as well as the best performing algorithms.

Date du colloque: 07/2008; International audience; The model of cognitive maps introduced by Tolman [1] provides a representation of an influence network between notions. A cognitive map can contain a lot of influences that makes difficult its exploitation. Moreover these influences are not always relevant for different uses of a map. This paper extends the cognitive map model by describing the validity context of each influence with a conceptual graph. A filtering mechanism of the influences according to a use context is provided so as to obtain a simpler and more adjusted map for a user. A prototype that implements this model of contextual cognitive map has been developed.

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-540-87405-8_29, Proceedings of 4th International Conference, ICGT 2008, Leicester, United Kingdom, September 7-13, 2008, We present a new, high-level approach for the specification of model-to-model transformations based on declarative patterns. These are (atomic or composite) constraints on triple graphs declaring the allowed or forbidden relationships between source and target models. In this way, a transformation is defined by specifying a set of triple graph constraints that should be satisfied by the result of the transformation. The description of the transformation is then compiled into lower-level operational mechanisms to perform forward or backward transformations, as well as to establish mappings between two existent models. In this paper we study one of such mechanisms based on the generation of operational triple graph grammar rules. Moreover, we exploit deduction techniques at the specification level in order to generate more specialized constraints (preserving the specification semantics) reflecting pattern dependencies, from which additional rules can be derived., Work supported by the Spanish Ministry of Education and Science, projects TSI2005-08225-C07-06 and TIN2006-09678.

The final publication is available at Springer via http://dx.doi.org/10.1007/11841883_25, Proceedings of Third International Conference, ICGT 2006 Natal, Rio Grande do Norte, Brazil, September 17-23, 2006, In this paper, we present our approach for model view management in the context of Multi-View Visual Languages (MVVLs). These are made of a number of diagram types (or viewpoints) that can be used for the specification of the different aspects of a system. Therefore, the user can build different system views conform to the viewpoints, which are merged in a repository in order to perform consistency checking. In addition, the user can define derived views by means of graph query patterns in order to extract information from a base model (a system view or the repository). We have provided automatic mechanisms to keep synchronized the base model and the derived view when the former changes. Predefined queries by the MVVL designer result in so-called audience-oriented views. Finally, semantic views are used for analysing the system by its translation into a semantic domain. Our approach is based on meta-modelling to describe the syntax of the MVVL and each viewpoint, and on triple graph transformation systems to synchronize and maintain correspondences between the system views and the repository, as well as between the derived, audience-oriented and semantic views and the base models. We illustrate these concepts by means of an example in the domain of security for web systems., This work has been sponsored by the Spanish Ministry of Science and Education, projects TSI2005-08225-C07-06 and TSI2004-03394.

Let Λ be a commutative ring, A an augmented differential graded algebra over Λ (briefly, DGA-algebra) and X be a relatively free resolution of Λ over A. The standard bar resolution of Λ over A, denoted by B(A), provides an example of a resolution of this kind. The comparison theorem gives inductive formulae f : B(A)→X and g : X→B(A) termed comparison maps. In case that fg=1 X and A is connected, we show that X is endowed a A ∞ -tensor product structure. In case that A is in addition commutative then (X,μ X ) is shown to be a commutative DGA-algebra with the product μ X =f*(g⊗g) (* is the shuffle product in B(A)). Furthermore, f and g are algebra maps. We give an example in order to illustrate the main results of this paper.

In this paper, algorithms for computing integer (co)homology of a simplicial complex of any dimension are designed, extending the work done in [1,2,3]. For doing this, the homology of the object is encoded in an algebraic-topological format (that we call AM-model). Moreover, in the case of 3D binary digital images, having as input AM-models for the images I and J, we design fast algorithms for computing the integer homology of I ∪J, I ∩J and I ∖J.

This paper introduces an algebraic framework for a topological analysis of time-varying 2D digital binary–valued images, each of them defined as 2D arrays of pixels. Our answer is based on an algebraic-topological coding, called AT–model, for a nD (n=2,3) digital binary-valued image I consisting simply in taking I together with an algebraic object depending on it. Considering AT–models for all the 2D digital images in a time sequence, it is possible to get an AT–model for the 3D digital image consisting in concatenating the successive 2D digital images in the sequence. If the frames are represented in a quadtree format, a similar positive result can be derived.

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-540-30212-4_15, Revised and Selected Papers of ECCV 2004 Workshop SMVP 2004, Prague, Czech Republic, May 16, 2004, The lack of sufficient machine readable images makes impossible the direct computation of natural image 4 × 4 block statistics and one has to resort to indirect approximated methods to reduce their domain space. A natural approach to this is to collect statistics over compressed images; if the reconstruction quality is good enough, these statistics will be sufficiently representative. However, a requirement for easier statistics collection is that the method used provides a uniform representation of the compression information across all patches, something for which codebook techniques are well suited. We shall follow this approach here, using a fractal compression–inspired quantization scheme to approximate a given patch B by a triplet (D B , μ B , σ B ) with σ B the patch’s contrast, μ B its brightness and D B a codebook approximation to the mean–variance normalization (B – μ B )/σ B of B. The resulting reduction of the domain space makes feasible the computation of entropy and mutual information estimates that, in turn, suggest a factorization of the approximation of p(B) ≃ p(D B , μ B , σ B ) as p(D B , μ B , σ B ) ≃ p(D B )p(μ)p(σ)Φ(|| ∇ ||), with Φ being a high contrast correction., With partial support of Spain’s CICyT, TIC 01–572

This paper is devoted to the study of graph embeddings in the grid of non-planar surfaces. We provide an adequate model for those embeddings and we study the complexity of minimizing the number of bends. In particular, we prove that testing whether a graph admits a rectilinear (without bends) embedding essentially equivalent to a given embedding, and that given a graph, testing if there exists a surface such that the graph admits a rectilinear embedding in that surface are NP-complete problems and hence the corresponding optimization problems are NP-hard.

Performance analysis is very important to understand the applications’ behavior and to identify bottlenecks. Performance analysis tools should facilitate the exploration of the data collected and help to identify where the analyst has to look. While this functionality can promote the tools usage on small and medium size environments, it becomes mandatory for large-scale and many-core systems where the amount of data is dramatically increased. This paper proposes a new methodology based on the integration of profilers and timeline tools to improve and facilitate the performance analysis process.