134,637 research outputs found
Towards Model-Driven Development of Access Control Policies for Web Applications
We introduce a UML-based notation for graphically modeling
systems’ security aspects in a simple and intuitive
way and a model-driven process that transforms graphical
specifications of access control policies in XACML. These
XACML policies are then translated in FACPL, a policy
language with a formal semantics, and the resulting policies
are evaluated by means of a Java-based software tool
Expressing and enforcing user-defined constraints of AADL models
The Architecture Analysis and Design Language AADL allows one to model complete systems, but also to define specific extensions through property sets and library of models. Yet, it does not define an explicit mechanism to enforce some semantics or consistency checks to ensure property sets are correctly used. In this paper, we present REAL (Requirements and Enforcements Analysis Language) as an integrated solution to this issue. REAL is defined as an AADL annex language. It adds the possibility to express constraints as theorems based on set theory to enforce implicit semantics of property sets or AADL models. We illustrate the use of the language on case studies we developed with industrial partners
XSRL: An XML web-services request language
One of the most serious challenges that web-service enabled e-marketplaces face is the lack of formal support for expressing service requests against UDDI-resident web-services in order to solve a complex business problem. In this paper we present a web-service request language (XSRL) developed on the basis of AI planning and the XML database query language XQuery. This framework is designed to handle and execute XSRL requests and is capable of performing planning actions under uncertainty on the basis of refinement and revision as new service-related information is accumulated (via interaction with the user or UDDI) and as execution circumstances necessitate change
Metamodel-based model conformance and multiview consistency checking
Model-driven development, using languages such as UML and BON, often makes use of multiple diagrams (e.g., class and sequence diagrams) when modeling systems. These diagrams, presenting different views of a system of interest, may be inconsistent. A metamodel provides a unifying framework in which to ensure and check consistency, while at the same time providing the means to distinguish between valid and invalid models, that is, conformance. Two formal specifications of the metamodel for an object-oriented modeling language are presented, and it is shown how to use these specifications for model conformance and multiview consistency checking. Comparisons are made in terms of completeness and the level of automation each provide for checking multiview consistency and model conformance. The lessons learned from applying formal techniques to the problems of metamodeling, model conformance, and multiview consistency checking are summarized
Web and Semantic Web Query Languages
A number of techniques have been developed to facilitate
powerful data retrieval on the Web and Semantic Web. Three categories
of Web query languages can be distinguished, according to the format
of the data they can retrieve: XML, RDF and Topic Maps. This article
introduces the spectrum of languages falling into these categories
and summarises their salient aspects. The languages are introduced using
common sample data and query types. Key aspects of the query
languages considered are stressed in a conclusion
Open Programming Language Interpreters
Context: This paper presents the concept of open programming language
interpreters and the implementation of a framework-level metaobject protocol
(MOP) to support them. Inquiry: We address the problem of dynamic interpreter
adaptation to tailor the interpreter's behavior on the task to be solved and to
introduce new features to fulfill unforeseen requirements. Many languages
provide a MOP that to some degree supports reflection. However, MOPs are
typically language-specific, their reflective functionality is often
restricted, and the adaptation and application logic are often mixed which
hardens the understanding and maintenance of the source code. Our system
overcomes these limitations. Approach: We designed and implemented a system to
support open programming language interpreters. The prototype implementation is
integrated in the Neverlang framework. The system exposes the structure,
behavior and the runtime state of any Neverlang-based interpreter with the
ability to modify it. Knowledge: Our system provides a complete control over
interpreter's structure, behavior and its runtime state. The approach is
applicable to every Neverlang-based interpreter. Adaptation code can
potentially be reused across different language implementations. Grounding:
Having a prototype implementation we focused on feasibility evaluation. The
paper shows that our approach well addresses problems commonly found in the
research literature. We have a demonstrative video and examples that illustrate
our approach on dynamic software adaptation, aspect-oriented programming,
debugging and context-aware interpreters. Importance: To our knowledge, our
paper presents the first reflective approach targeting a general framework for
language development. Our system provides full reflective support for free to
any Neverlang-based interpreter. We are not aware of any prior application of
open implementations to programming language interpreters in the sense defined
in this paper. Rather than substituting other approaches, we believe our system
can be used as a complementary technique in situations where other approaches
present serious limitations
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