39,945 research outputs found
Specification and Construction of Control Flow Semantics
In this paper we propose a visual language CFSL for specifying control flow semantics of programming languages. We also present a translation from CFSL to graph production systems (GPS) for flow graph construction; that is, any CFSL specification, say for a language L, gives rise to a GPS that constructs from any L-program (represented as an abstract syntax graph) the corresponding flow graph. The specification language is rich enough to capture complex language constructs, including all of Java
Layout Specification on the Concrete and Abstract Syntax Level of a Diagram Language
A visual language consists of several visual component types, e.g. states or transitions in DFAs. Nowadays, the language itself is usually specified via a meta model.
To make a diagram look nice, a layouter is required.
This layouter may either operate on the concrete syntax level, i.e., on the visual components, or on the abstract syntax level, i.e., on the model instance.
In this paper we present an approach that is capable of specifying a flexible layout on both, the concrete as well as the abstract syntax level of a diagram. The approach uses pattern-based transformations. Besides structured editing, it also supports free-hand editing, a challenging task for the layouter. We introduce how such a specification can be created and examine the advantages and shortcomings of each of either operating on the concrete syntax level or on the abstract syntax level
Generating Correctness-Preserving Editing Operations for Diagram Editors
In previous work it has already been shown that syntax-directed and free-hand editing can be gainfully integrated into a single diagram editor. That way, the user can arrange diagram components on the screen without any restrictions in free-hand editing mode, whereas syntax-directed editing operations provide powerful assistance. So far, editing operations had to be specified or programmed by the editor developer. In contrast, this paper proposes an approach where diagram-specific editing operations are generated on the fly during the editing process and without any additional specification effort. These operations provably preserve the correctness of the diagram. The proposed approach requires a specification of the visual language by a hypergraph grammar
Distributed event graphs: Formalizing component-based modelling and simulation
Proceedings of the Workshop on Visual Languages and Formal Methods (VLFM 2004), Visual Languages and Formal Methods 2004In this work an extension to the classical Event Graphs formalism for discrete-event simulation is presented. The extensions are oriented towards the specification of component-based models. The abstract syntax has been defined through meta-modelling. Several methodological issues are discussed, concerning the use of two different meta-modelling levels or collapsing the language into a single one, where āinstance-ofā relationships are used between processes and their classes. The operational semantics have been defined through graph transformation. This formal definition enables analysis before code is generated from the model. The syntax and semantics of the visual language have been implemented in the multi-paradigm tool AToM3, together with a code generator that produces stand-alone applications able to run the analysed models in real-time.Iād like to thank the three anonymous referees for their comments, and the
sponsors of this work: the Spanish Ministry of Science and Technology (TIC2002-
01948) and the Santander Central Hispano Bank
Drawing OWL 2 ontologies with Eddy the editor
In this paper we introduce Eddy, a new open-source tool for the graphical editing of OWL~2 ontologies. Eddy is specifically designed for creating ontologies in Graphol, a completely visual ontology language that is equivalent to OWL~2. Thus, in Eddy ontologies are easily drawn as diagrams, rather than written as sets of formulas, as commonly happens in popular ontology design and engineering environments.
This makes Eddy particularly suited for usage by people who are more familiar with diagramatic languages for conceptual modeling rather than with typical ontology formalisms, as is often required in non-academic and industrial contexts. Eddy provides intuitive functionalities for specifying Graphol diagrams, guarantees their syntactic correctness, and allows for exporting them in standard OWL 2 syntax. A user evaluation study we conducted shows that Eddy is perceived as an easy and intuitive tool for ontology specification
Managing QoS in a NGN using a PBM approach
Next Generation Network (NGN) management
represents an enormous challenge due to the large number of
managed elements, the variety of roles the managed entities
play in the network and the difficulty of orchestrating
management actions. Several NGN standardization bodies
point toward Policy Based Management as the best approach
for NGN network management.
This paper describes a management solution for a NGN IP
Multimedia Subsystem (IMS) QoS management scenario based
on WBEM technology. The proposal is for a WBEM-based
policy server, a graphical policy editor application and
instrumentation logic for the NGN QoS Management. The
graphical policy editor reduces the learning curve imposed by
the policy specification language, allowing the specification of
policies through a rich and user-friendly visual interface,
hiding the CIM syntax complexity but keeping CIMās
potential
On the role of domain ontologies in the design of domain-specific visual modeling langages
Domain-Specific Visual Modeling Languages should provide notations and abstractions that suitably support problem solving in well-defined application domains. From their userās perspective, the languageās modeling primitives must be intuitive and expressive enough in capturing all intended aspects of domain conceptualizations. Over the years formal and explicit representations of domain conceptualizations have been developed as domain ontologies. In this paper, we show how the design of these languages can benefit from conceptual tools developed by the ontology engineering community
NITELIGHT: A Graphical Tool for Semantic Query Construction
Query formulation is a key aspect of information retrieval, contributing to both the efficiency and usability of many semantic applications. A number of query languages, such as SPARQL, have been developed for the Semantic Web; however, there are, as yet, few tools to support end users with respect to the creation and editing of semantic queries. In this paper we introduce a graphical tool for semantic query construction (NITELIGHT) that is based on the SPARQL query language specification. The tool supports end users by providing a set of graphical notations that represent semantic query language constructs. This language provides a visual query language counterpart to SPARQL that we call vSPARQL. NITELIGHT also provides an interactive graphical editing environment that combines ontology navigation capabilities with graphical query visualization techniques. This paper describes the functionality and user interaction features of the NITELIGHT tool based on our work to date. We also present details of the vSPARQL constructs used to support the graphical representation of SPARQL queries
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