1,295,053 research outputs found
Ontology-based semantic interpretation of cylindricity specification in the next-generation GPS
Cylindricity specification is one of the most important geometrical specifications in geometrical product development. This specification can be referenced from the rules and examples in tolerance standards and technical handbooks in practice. These rules and examples are described in the form of natural language, which may cause ambiguities since different designers may have different understandings on a rule or an example.
To address the ambiguous problem, a categorical data model of cylindricity specification in the next-generation Geometrical Product Specifications (GPS) was proposed at the University of Huddersfield. The modeling language used in the categorical data model is category
language. Even though category language can develop a syntactically correct data model, it is difficult to interpret the semantics of the cylindricity specification explicitly. This paper proposes an ontology-based approach to interpret the semantics of cylindricity specification on
the basis of the categorical data model. A scheme for translating the category language to the OWL 2 Web Ontology Language (OWL 2) is presented in this approach. Through such a scheme, the categorical data model is translated into a semantically enriched model, i.e. an OWL 2
ontology for cylindricity specification. This ontology can interpret the semantics of cylindricity specification explicitly. As the benefits of such semantic interpretation, consistency checking, inference procedures and semantic queries can be performed on the OWL 2 ontology. The proposed approach could be easily extended to support the semantic interpretations of other kinds of geometrical specifications
A test generation framework for quiescent real-time systems
We present an extension of Tretmans theory and algorithm for test generation for input-output transition systems to real-time systems. Our treatment is based on an operational interpretation of the notion of quiescence in the context of real-time behaviour. This gives rise to a family of implementation relations parameterized by observation durations for quiescence. We define a nondeterministic (parameterized) test generation algorithm that generates test cases that are sound with respect to the corresponding implementation relation. Also, the test generation is exhaustive in the sense that for each non-conforming implementation a test case can be generated that detects the non-conformance
Electroweak Theory without a Higgs potential: Radiative Effects
We examine the one loop effective potential in a recently proposed (by
Chernodub et. al.) alternative approach to mass generation in the Higgs-gauge
sector of the electroweak theory, which does not make use of a classical Higgs
potential. We show that the interpretation given by these authors, of the Higgs
boson as the conformal degree of freedom in a background conformal gravity
theory, is invalidated because genuine one loop radiative effects cancel the
local functional measure of the Higgs field taken to be the basis of this
interpretation. Functional evaluation of the one loop effective Higgs potential
leads to a minimum away from the origin, thereby providing yet another
radiative mass generation scheme for weak gauge bosons. In arriving at the one
loop effective potential we make use of the gauge free formulation of
electrodynamics introduced by us earlier, which obviates any need for gauge
fixing.Comment: 8 Pages Latex 2e with one eps figur
High resolution spectroscopy in the microwave and far infrared
High resolution rotational spectroscopy has long been central to remote sensing techniques in atmospheric sciences and astronomy. As such, laboratory measurements must supply the required data to make direct interpretation of data for instruments which sense atmospheres using rotational spectra. Spectral measurements in the microwave and far infrared regions are also very powerful tools when combined with infrared measurements for characterizing the rotational structure of vibrational spectra. In the past decade new techniques were developed which have pushed high resolution spectroscopy into the wavelength region between 25 micrometers and 2 mm. Techniques to be described include: (1) harmonic generation of microwave sources, (2) infrared laser difference frequency generation, (3) laser sideband generation, and (4) ultrahigh resolution interferometers
The interrelation between the generation of large-scale electric fields and that of large-scale magnetic fields during inflation
The interrelation between the generation of large-scale electric fields and
that of large-scale magnetic fields due to the breaking of the conformal
invariance of the electromagnetic field in inflationary cosmology is studied.
It is shown that if large-scale magnetic fields with a sufficiently large
amplitude are generated during inflation, the generation of large-scale
electric fields is suppressed, and vice versa. Furthermore, a physical
interpretation of the result and its cosmological significance are considered.Comment: 12 pages, no figure, title changed, typos correcte
On the variations of the principal eigenvalue with respect to a parameter in growth-fragmentation models
We study the variations of the principal eigenvalue associated to a
growth-fragmentation-death equation with respect to a parameter acting on
growth and fragmentation. To this aim, we use the probabilistic
individual-based interpretation of the model. We study the variations of the
survival probability of the stochastic model, using a generation by generation
approach. Then, making use of the link between the survival probability and the
principal eigenvalue established in a previous work, we deduce the variations
of the eigenvalue with respect to the parameter of the model
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