708 research outputs found

    Superlanguages: developing languages and applications with XMF.

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    Superlanguages offer a wide range of technologies that support application development. In particular Superlanguages support Language Oriented Programming and Domain Specific Languages through syntax extensions and meta-programming. XMF has been designed as a Superlanguage and can be downloaded from this web site. This book describes Superlanguage features and shows how XMF can be used to develop new languages and applications

    Applied metamodelling: a foundation for language driven development.

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    The motivation behind XMF was to develop a technology that would support a language driven approach to modelling and system development. Our starting point was that UML was not sufficiently flexible and in order to address this we designed an executable meta-language. This book describes the approach and provides an introduction to the key technologies: meta-models, language definition and mappings. The book concludes with a number of worked examples

    Beyond annotations: a proposal for extensible java (XJ).

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    The XMF system is based on a bespoke language that includes some features that are key to Language Oriented Programming: grammars; syntax classes; parsers; quasi-quotes. This paper discusses various technologies and approaches for LOP and concludes that standardization is one of the key features that will bring LOP and Domain Specific Languages to the mainstream. The paper proposes an extension to Java that incorporates the key LOP and DSL features of XMF. The essential Java extensions are discussed and the paper concludes with a couple of examples

    Cysts of the jaws

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    The clinical behaviour of cysts of the jaws has been under close scrutiny over the last few years as it has been found that there is in some types a distinct risk of recurrence. This recurrence may occur even after as long as 20 years, so that long term follow-up is essential. The clinical and histological features may be important clues in determining the prognosis and the risk of recurrence of the various jaw cysts. The data of jaw cysts seen at the Dental Department, St. Luke's Hospital, Malta during the decade 1960 – 1969 is collected in order to establish a base line for future comparative studies. There were 49 patients with cysts of the jaws and histological examination was made in 31 cases. The preponderance of periodontal cysts (30.6%) agrees with most large surveys reported, as does the percentage incidence (16.3%) of dentigerous cysts.peer-reviewe

    Corporate reputation and organisational performance: an Australian study

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    PURPOSE - To test for a relationship between corporate reputation and financial performance, using Australian data. DESIGN/METHODOLOGY/APPROACH - Econometric modelling. FINDINGS - No causal relationship between corporate reputation and financial performance (in either direction) was found. This is contrary to some findings in other countries. Reputation may not have a significant impact on performance in Australia. There may be weaknesses in the existing measure of reputation, or the finding may be due to unobserved variability in the intervening variable of managerial exploitation of the reputation. RESEARCH LIMITATIONS/IMPLICATIONS - The findings may be specific to Australia. In Australia, the linkage between reputation and performance may be too small to be significant in the available sample. It is argued that in corporate practice the link between reputation and performance proceeds via strategy and competitive advantage. Having a reputation resource is not enough; it needs to be managed well and exploited if it is to yield financial results. More work is needed to establish reliable measures of reputation. ORIGINALITY/VALUE - It is the first known study to investigate the link on Australian data. The discussion of the findings raises issues for the measurement and management of reputation

    Revised submission for MOF 2.0 query / views / transformations RFP.

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    This submission presents the QVT-Partners proposal for the MOF 2.0 QVT standard. The proposal consists of a number of key ingredients which we briefly discuss in this section. -Specification and implementation: A common scenario in the development of any artifact is to first create a specification of the form and behaviour of the the artifact, and then realise an implementation which satisfies the specification. The specification is characterised by a lack of implementation details, but having a close correspondence to the requirements; conversely an implementation may lack close correspondence to the requirements. This submission maintains this important distinction. Relations provide a specification oriented view of the relationship between models and are specified in a language that can be easily understood. They say what it means to translate between several models but without saying precisely how the translation is achieved. Those details are realised by mappings which characterise the means by which models are translated. It should be noted though, that while the mappings language is rich enough to provide an implementation of relations it also manages to maintain a requirements oriented focus. This may give rise to a scenario where developers prefer to omit relations and directly define mappings. -Scalability and reuse: Decomposition is a key approach to managing complexity. This submission provides a number of composition mechanisms whereby relations and mappings can be composed to form more complex specifications. These mechanisms also aid reuse since mappings and relations can be treated as reusable components which are composed for specific contexts. -Usability: Diagrammatic notations have been important to the success of many OMG standards. This proposal presents a diagrammatic notation which is an extension of collaboration object diagrams and is therefore familiar to many end users. A criticism often levelled at diagrammatic notations is their scalability. This submission also presents a textual syntax, constructs of the diagrammatic notations are closely aligned with its textual counterpart. Considering the domains of relations and mappings at the generic type level is often too limiting. Instead it often is specific-types of things that are of interest. This submission uses patterns to describe the domains of both relations and mappings. Patterns are a means of succinctly describing specific-types of model elements and enable domains of interest to be rapidly stated with ease. -Semantic soundness: By definition a standard should give rise to consistency across differing implementations. It is important that an end user can get the same results on two different implementations. For this reason, this submission goes to some effort to ensure that all the constructs have a well-defined semantic basis. This is achieved by treating the submission in two parts. The infrastructure part has a small number of constructs which can be easily and consistently understood from informal descriptions (although a mathematical semantics is given in Appendix B for the sake of completeness and rigour). The superstructure part uses the infrastructure as its semantic basis and defines the syntax that the end user deals with. The relationship between the superstructure and the infrastructure is expressed as a translation

    An action semantics for MML.

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    This paper describes an action semantics for UML based on the Meta-Modelling Language (MML) - a precise meta-modelling language designed for developing families of UML languages. Actions are de¯ned as computational procedures with side-e®ects. The action semantics are described in the MML style, with model, instance and semantic packages. Di®erent actions are described as specializations of the basic action in their own package. The aim is to show that by using a Catalysis like package extension mechanism, with precise mappings to a simple semantic domain, a well-structured and extensible model for an action language can be obtained

    Defining OCL expressions using templates.

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    OCL expressions are an essential part of UML. The current versions of OCL fail to have a meta-model which means that the integration of OCL with the UML meta-model cannot be formally defined [1]. This can result in ambiguous descriptions of systems which may compromise designs. The need to redesign the OCL has been addressed by a number of proposals submitted to the OMG. In this paper we demonstrate how a definition for OCL can be stamped out from a small number of templates. Such an approach enables a high level of reuse and an increased confidence that the definition is correct. This work forms part of the 2U consortium’s efforts for the definition of UML 2.0
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