10,216 research outputs found
Model transformations in Converge
Model transformations are currently the focus of much interest and research due to the OMGās QVT initiative. Current proposals for model transformation languages
can be divided into two main camps: those taking a ādeclarativeā approach, and those opting for an āimperativeā approach. In this paper we detail an imperative, meta-circular, object orientated, pattern matching programming language Converge which is enriched with features pioneered by the Icon programming language,
amongst them: success/failure, generators and goal-directed evaluation. By presenting these features in a language suitable for representing models, we show
that we are able to gain some of the advantages of declarative approaches in an imperative setting
Icon: A Interpreter-Based Approach
This paper introduces the Icon programming language in a simplified form using a lisp-like syntax to represent an interesting subset of the language. The paper also discusses the semantics and implementation of some of Icon\u27s advanced features with emphasis on generators and goal-directed evaluation. The organization of the paper resembles a chapter in the book ``Programming Languages: An Interpreter-Based Approach\u27\u27 by Samuel Kamin. This paper can serve as a supplement to that book, allowing comparative programming language instructors who use the Kamin text to efficiently teach the Icon programming languag
Survey of currently available high-resolution raster graphics systems
Presented are data obtained on high-resolution raster graphics engines currently available on the market. The data were obtained through survey responses received from various vendors and also from product literature. The questionnaire developed for this survey was basically a list of characteristics desired in a high performance color raster graphics system which could perform real-time aircraft simulations. Several vendors responded to the survey, with most reporting on their most advanced high-performance, high-resolution raster graphics engine
Differential geometry, Palatini gravity and reduction
The present article deals with a formulation of the so called (vacuum)
Palatini gravity as a general variational principle. In order to accomplish
this goal, some geometrical tools related to the geometry of the bundle of
connections of the frame bundle are used. A generalization of
Lagrange-Poincar\'e reduction scheme to these types of variational problems
allows us to relate it with the Einstein-Hilbert variational problem. Relations
with some other variational problems for gravity found in the literature are
discussed.Comment: 28 pages, no figures. (v3) Remarks, discussion and references adde
The Infati Data
The ability to perform meaningful empirical studies is of essence in research
in spatio-temporal query processing. Such studies are often necessary to gain
detailed insight into the functional and performance characteristics of
proposals for new query processing techniques.
We present a collection of spatio-temporal data, collected during an
intelligent speed adaptation project, termed INFATI, in which some two dozen
cars equipped with GPS receivers and logging equipment took part. We describe
how the data was collected and how it was "modified" to afford the drivers some
degree of anonymity.
We also present the road network in which the cars were moving during data
collection.
The GPS data is publicly available for non-commercial purposes. It is our
hope that this resource will help the spatio-temporal research community in its
efforts to develop new and better query processing techniques
Routh reduction and Cartan mechanics
In the present work a Cartan mechanics version for Routh reduction is
considered, as an intermediate step toward Routh reduction in field theory.
Motivation for this generalization comes from an scheme for integrable systems
[12], used for understanding the occurrence of Toda field theories in so called
Hamiltonian reduction of WZNW field theories [11]. As a way to accomplish with
this intermediate aim, this article also contains a formulation of the
Lagrangian Adler-Kostant-Symes systems discussed in [12] in terms of Routh
reduction.Comment: 46 pages, comments are welcome. Version 2 contains an additional
section concerning reduced equations of motion in quasicoordinate
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