23,588 research outputs found
On the algebra of structured specifications
AbstractWe develop module algebra for structured specifications with model oriented denotations. Our work extends the existing theory with specification building operators for non-protecting importation modes and with new algebraic rules (most notably for initial semantics) and upgrades the pushout-style semantics of parameterized modules to capture the (possible) sharing between the body of the parameterized modules and the instances of the parameters. We specify a set of sufficient abstract conditions, smoothly satisfied in the actual situations, and prove the isomorphism between the parallel and the serial instantiation of multiple parameters. Our module algebra development is done at the level of abstract institutions, which means that our results are very general and directly applicable to a wide variety of specification and programming formalisms that are rigorously based upon some logical system
On the probabilities of local behaviors in abelian field extensions
For a number field K and a finite abelian group G, we determine the
probabilities of various local completions of a random G-extension of K when
extensions are ordered by conductor. In particular, for a fixed prime p of K,
we determine the probability that p splits into r primes in a random
G-extension of K that is unramified at p. We find that these probabilities are
nicely behaved and mostly independent. This is in analogy to Chebotarev's
density theorem, which gives the probability that in a fixed extension a random
prime of K splits into r primes in the extension. We also give the asymptotics
for the number of G-extensions with bounded conductor. In fact, we give a class
of extension invariants, including conductor, for which we obtain the same
counting and probabilistic results. In contrast, we prove that that neither the
analogy with the Chebotarev probabilities nor the independence of probabilities
holds when extensions are ordered by discriminant.Comment: 28 pages, submitte
An Algebra of Hierarchical Graphs
We define an algebraic theory of hierarchical graphs, whose axioms characterise graph isomorphism: two terms are equated exactly when they represent the same graph. Our algebra can be understood as a high-level language for describing graphs with a node-sharing, embedding structure, and it is then well suited for defining graphical representations of software models where nesting and linking are key aspects
Abstract State Machines 1988-1998: Commented ASM Bibliography
An annotated bibliography of papers which deal with or use Abstract State
Machines (ASMs), as of January 1998.Comment: Also maintained as a BibTeX file at http://www.eecs.umich.edu/gasm
The foundational legacy of ASL
Abstract. We recall the kernel algebraic specification language ASL and outline its main features in the context of the state of research on algebraic specification at the time it was conceived in the early 1980s. We discuss the most significant new ideas in ASL and the influence they had on subsequent developments in the field and on our own work in particular.
Specification Techniques for Multi-Modal Dialogues in the U-Wish Project
In this paper we describe the development of a specification\ud
technique for specifying interactive web-based services. We\ud
wanted to design a language that can be a means of\ud
communication between designers and developers of interactive services, that makes it easier to develop web-based services fitted to the users and that shortens the pathway from design to implementation. The language, still under development, is based on process algebra and can be\ud
connected to the results of task analysis. We have been\ud
working on the automatic generation of executable prototypes\ud
out of the specifications. In this way the specification\ud
language can establish a connection between users, design\ud
and implementation. A first version of this language is\ud
available as well as prototype tools for executing the specifications. Ideas will be given as to how to make the connection between specifications and task analysis
Evaluating openEHR for storing computable representations of electronic health record phenotyping algorithms
Electronic Health Records (EHR) are data generated during routine clinical
care. EHR offer researchers unprecedented phenotypic breadth and depth and have
the potential to accelerate the pace of precision medicine at scale. A main EHR
use-case is creating phenotyping algorithms to define disease status, onset and
severity. Currently, no common machine-readable standard exists for defining
phenotyping algorithms which often are stored in human-readable formats. As a
result, the translation of algorithms to implementation code is challenging and
sharing across the scientific community is problematic. In this paper, we
evaluate openEHR, a formal EHR data specification, for computable
representations of EHR phenotyping algorithms.Comment: 30th IEEE International Symposium on Computer-Based Medical Systems -
IEEE CBMS 201
A formal support to business and architectural design for service-oriented systems
Architectural Design Rewriting (ADR) is an approach for the design of software architectures developed within Sensoria by reconciling graph transformation and process calculi techniques. The key feature that makes ADR a suitable and expressive framework is the algebraic handling of structured graphs, which improves the support for specification, analysis and verification of service-oriented architectures and applications. We show how ADR is used as a formal ground for high-level modelling languages and approaches developed within Sensoria
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