1,693 research outputs found
A Reasoner for Calendric and Temporal Data
Calendric and temporal data are omnipresent in countless
Web and Semantic Web applications and Web services. Calendric and
temporal data are probably more than any other data a subject to
interpretation, in almost any case depending on some cultural, legal,
professional, and/or locational context. On the current Web, calendric
and temporal data can hardly be interpreted by computers. This article
contributes to the Semantic Web, an endeavor aiming at enhancing
the current Web with well-defined meaning and to enable computers to
meaningfully process data. The contribution is a reasoner for calendric
and temporal data. This reasoner is part of CaTTS, a type language for
calendar definitions. The reasoner is based on a \theory reasoning" approach
using constraint solving techniques. This reasoner complements
general purpose \axiomatic reasoning" approaches for the Semantic Web
as widely used with ontology languages like OWL or RDF
A Reasoner for Calendric and Temporal Data
Calendric and temporal data are omnipresent in countless
Web and Semantic Web applications and Web services. Calendric and
temporal data are probably more than any other data a subject to
interpretation, in almost any case depending on some cultural, legal,
professional, and/or locational context. On the current Web, calendric
and temporal data can hardly be interpreted by computers. This article
contributes to the Semantic Web, an endeavor aiming at enhancing
the current Web with well-defined meaning and to enable computers to
meaningfully process data. The contribution is a reasoner for calendric
and temporal data. This reasoner is part of CaTTS, a type language for
calendar definitions. The reasoner is based on a "theory reasoning" approach
using constraint solving techniques. This reasoner complements
general purpose "axiomatic reasoning" approaches for the Semantic Web
as widely used with ontology languages like OWL or RDF
Standard Model Parton Distributions at Very High Energies
We compute the leading-order evolution of parton distribution functions for
all the Standard Model fermions and bosons up to energy scales far above the
electroweak scale, where electroweak symmetry is restored. Our results include
the 52 PDFs of the unpolarized proton, evolving according to the SU(3), SU(2),
U(1), mixed SU(2) x U(1) and Yukawa interactions. We illustrate the numerical
effects on parton distributions at large energies, and show that this can lead
to important corrections to parton luminosities at a future 100 TeV collider.Comment: 30 pages, 7 figures. Improved treatment of input PDFs at 100 GeV.
Adjusted plotting style to show features more clearly. Main results and
conclusions unchange
Review of research in feature-based design
Research in feature-based design is reviewed. Feature-based design is regarded as a key factor towards CAD/CAPP integration from a process planning point of view. From a design point of view, feature-based design offers possibilities for supporting the design process better than current CAD systems do. The evolution of feature definitions is briefly discussed. Features and their role in the design process and as representatives of design-objects and design-object knowledge are discussed. The main research issues related to feature-based design are outlined. These are: feature representation, features and tolerances, feature validation, multiple viewpoints towards features, features and standardization, and features and languages. An overview of some academic feature-based design systems is provided. Future research issues in feature-based design are outlined. The conclusion is that feature-based design is still in its infancy, and that more research is needed for a better support of the design process and better integration with manufacturing, although major advances have already been made
Report on the formal specification and partial verification of the VIPER microprocessor
The formal specification and partial verification of the VIPER microprocessor is reviewed. The VIPER microprocessor was designed by RSRE, Malvern, England, for safety critical computing applications (e.g., aircraft, reactor control, medical instruments, armaments). The VIPER was carefully specified and partially verified in an attempt to provide a microprocessor with completely predictable operating characteristics. The specification of VIPER is divided into several levels of abstraction, from a gate-level description up to an instruction execution model. Although the consistency between certain levels was demonstrated with mechanically-assisted mathematical proof, the formal verification of VIPER was never completed
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Extended Functional Unification ProGrammars
Functional Unification Grammars (PUGs) are popular for natural language applications because the formalism uses very few primitives and is uniform and expressive. In our work on text generation, we have found that it also has annoying limitations: it is not adapted to the expression of simple yet very common taxonomic relations and it does not allow easy manipulation of complex data-structures like lists or sets. We present in this paper a set of extensions that keep the desirable properties of the formalism but make it more flexible and easier to use. We first introduce the notion of typed features and typed constituents. Types define a structure over the set of primitive symbols used by the formalism. We then introduce extended unification: specialized unification methods can be defined for user-defined data-types. This extends the power of the system to handle complex data-structures efficiently. Taking advantage of a structured set of primitives and of specialized unification methods, the resulting formalism is more flexible, easier to use and produces better documented grammars than traditional functional unification. It can therefore be used to address deeper levels of text generation than was possible before
Automatic Calculation of supersymmetric Renormalization Group Equations and Self Energies
SARAH is a Mathematica package for studying supersymmetric models. It
calculates for a given model the masses, tadpole equations and all vertices at
tree-level. Those information can be used by \SARAH to write model files for
CalcHep/CompHep or FeynArts/FormCalc. In addition, the second version of SARAH
can derive the renormalization group equations for the gauge couplings,
parameters of the superpotential and soft-breaking parameters at one and
two-loop level. Furthermore, it calculates the one-loop self energies and the
one-loop corrections to the tadpoles. SARAH can handle all N=1 SUSY models
whose gauge sector is a direct product of SU(N) and U(1) gauge groups. The
particle content of the model can be an arbitrary number of chiral superfields
transforming as any irreducible representation with respect to the gauge
groups. To implement a new model, the user has just to define the gauge sector,
the particle, the superpotential and the field rotations to mass eigenstates.Comment: 32 pages, some typoes corrected, matches published versio
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