603 research outputs found

    Service life design for infrastructure

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    In the past few years more and more attention has been devoted to the safety and serviceability as well as durability and sustainability of structures. Meanwhile there are intensive research and development activities going on, e.g. on materials properties, deterioration mechanisms, geometric- and structural design, execution aspect and maintenance. Furthermore, codes and standards on service life design are being discussed and partially established world wide. It is now time to present a focused picture of the current status and future trends in this field, including theory, practice and education. The aim of the symposium is to provide a forum to researchers and practitioners for presenting the newest findings and to discuss new ideas on service life design and serviceability of infrastructural Works, effectiveness of service life design methods and experiences from the practice

    A generation-oriented workbench for performance grammar: Capturing linear order variability in German and Dutch

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    We describe a generation-oriented workbench for the Performance Grammar (PG) formalism, highlighting the treatment of certain word order and movement constraints in Dutch and German. PG enables a simple and uniform treatment of a heterogeneous collection of linear order phenomena in the domain of verb constructions (variably known as Cross-serial Dependencies, Verb Raising, Clause Union, Extraposition, Third Construction, Particle Hopping, etc.). The central data structures enabling this feature are clausal “topologies”: one-dimensional arrays associated with clauses, whose cells (“slots”) provide landing sites for the constituents of the clause. Movement operations are enabled by unification of lateral slots of topologies at adjacent levels of the clause hierarchy. The PGW generator assists the grammar developer in testing whether the implemented syntactic knowledge allows all and only the well-formed permutations of constituents

    A generation-oriented workbench for performance grammar: Capturing linear order variability in German and Dutch

    Get PDF
    We describe a generation-oriented workbench for the Performance Grammar (PG) formalism, highlighting the treatment of certain word order and movement constraints in Dutch and German. PG enables a simple and uniform treatment of a heterogeneous collection of linear order phenomena in the domain of verb constructions (variably known as Cross-serial Dependencies, Verb Raising, Clause Union, Extraposition, Third Construction, Particle Hopping, etc.). The central data structures enabling this feature are clausal “topologies”: one-dimensional arrays associated with clauses, whose cells (“slots”) provide landing sites for the constituents of the clause. Movement operations are enabled by unification of lateral slots of topologies at adjacent levels of the clause hierarchy. The PGW generator assists the grammar developer in testing whether the implemented syntactic knowledge allows all and only the well-formed permutations of constituents

    Service life design for infrastructure

    Get PDF
    In the past few years more and more attention has been devoted to the safety and serviceability as well as durability and sustainability of structures. Meanwhile there are intensive research and development activities going on, e.g. on materials properties, deterioration mechanisms, geometric- and structural design, execution aspect and maintenance. Furthermore, codes and standards on service life design are being discussed and partially established world wide. It is now time to present a focused picture of the current status and future trends in this field, including theory, practice and education. The aim of the symposium is to provide a forum to researchers and practitioners for presenting the newest findings and to discuss new ideas on service life design and serviceability of infrastructural Works, effectiveness of service life design methods and experiences from the practice

    Generalized bisimulation metrics

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    International audienceThe pseudometric based on the Kantorovich lifting is one of the most popular notion of distance between probabilistic processes proposed in the literature. However, its application in verification is limited to linear properties. We propose a generalization which allows to deal with a wider class of properties, such as those used in security and privacy. More precisely, we propose a family of pseudometrics, parametrized on a notion of distance which depends on the property we want to verify. Furthermore, we show that the members of this family still characterize bisimilarity in terms of their kernel, and provide a bound on the corresponding distance between trace distributions. Finally, we study the instance corresponding to differential privacy, and we show that it has a dual form, easier to compute. We also prove that the typical process-algebra constructs are non-expansive, thus paving the way to a modular approach to verification

    Predicción de las propiedades mecánicas del cemento en la micro-escala

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    Prediction of the mechanical properties of cement paste at microscale has been done in this contribution by making use of 3D lattice fracture model. The microstructure of cement paste is simulated by HYMOSTRUC3D first, which is represented in terms of sphere particles. Then the microstructure is converted into a voxel-based image, and a lattice system is constructed based on the image of the microstructure through ImgLat (Image to Lattice). A virtual uni-axial tensile test is configured and the fracture process is simulated by GLAK (Generalized Lattice Analysis Kernel). The outputs of fracture process simulation are the load-displacement diagram and micro-cracks propagation. The load-displacement diagram reveals the tensile behavior of cement paste at microscale, from which the elastic modulus and tensile strength can be obtained. A numerical experiment is carried out to show how the model works, and the final results also demonstrate the feasibility of the above modeling procedure.En el presente trabajo se ha realizado una predicción de las propiedades mecánicas del cemento en la micro-escala, empleando un modelo de fractura reticular 3D. En primer lugar se simula la micro-estructura del cemento mediante el código HYMOSTRUC3D, representando dicha micro-estructura mediante partículas esféricas. A continuación, la micro-estructura generada se convierte en una imagen basada en “vóxeles”, y se construye un sistema reticular basado en esa imagen mediante el código ImgLat (Image to Lattice). Se define un ensayo de tensión uniaxial virtual, y se simula el proceso de fractura usando el código GLAK (Generalized Lattice Análisis Kernel). Los resultados obtenidos de esta simulación del proceso de fractura son diagramas de carga-desplazamiento y propagación de micro-roturas. El diagrama de carga-desplazamiento caracteriza el comportamiento a fractura de la pasta de cemento en la micro-escala, y a partir de éste se puede obtener la resistencia a fractura y el módulo de elasticidad del material. Con el objetivo de mostrar el funcionamiento de la simulación, se ha realizado un experimento teórico, cuyos resultados sirven para validar el modelo empleado

    Measurement of advancing and receding contact angles between mercury and cement-based materials

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    The selection of the incorrect value of contact angles is one of the important error sources in calculating the pore size in mercury porosimetry studies. However, from literature, it is difficult to find out an appropriate technique, which can be used to measure both advancing and receding contact angles. In this paper, a new method is proposed to measure the advancing and receding contact angles between mercury and cement-based materials. This method is demonstrated with a measurement on Portland cement paste with the water-to-cement ratio of 0.3. This method can give very consistent results with the standard deviation lower than 1 %. The measured advancing and receding contact angles range from 131.7° to 138.6° and from 123.3° to 128.2°, respectively, as curing age increases from 3 days to 28 days
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