Thesis full text (PDF) - Politecnico di Milano

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2. Background 2.1 Model Driven Architecture (MDA) 2.1.1 Review of MDA The MDA defines an approach to IT system specification that separates the specification of system functionality from the specification of the implementation of that functionality on a specific technology platform. To this end, the MDA defines an architecture for models that provides a set of guidelines for structuring specifications expressed as models. The MDA is a new way of writing specifications, based on a platform-independent model. A complete MDA specification consists of a definitive platform-independent base UML model, plus one or more platform-specific models and interface definition sets, each describing how the base model is implemented on a different middleware platform. The MDA approach and the standards that support it allow the same model specifying system functionality to be realized on multiple platforms through auxiliary mapping standards, or through point mappings to specific platforms, and allow different applications to be integrated by explicitly relating their models, enabling integration and interoperability and supporting system evolution as platform technologies come and go. 2.1.2 Basic concepts Systems notions Two different system notions exist: the teleological and the ontological system notion [4]. The teleological system notion is about the function and the (external) behavior of a system. This notion can be visualized with a black-box model. The teleological system notion is adequate for the purpose of using or controlling a system. The ontological system notion, on the other side, can be used for building or changing a system. It is about the construction and operation of a system and can be modeled with a white-box model. 10
Both the teleological and the ontological system notion are relevant for designing a system [4]. In other words: both the functional and the constructional perspective of a system are relevant. In software, the terms functional design and technical design are often used to refer to these perspectives. Model A model of a system is a description or specification of that system and its environment for some certain purpose. A model is often presented as a combination of drawings and text. The text may be in a modeling language or in a natural language [5]. Viewpoint A viewpoint on a system is a technique for abstraction using a selected set of architectural concepts and structuring rules, in order to focus on particular concerns within that system. Here ‘abstraction' is used to mean the process of suppressing selected detail to establish a simplified model [5]. Platform A platform is a set of subsystems and technologies that provide a coherent set of functionality through interfaces and specified usage patterns, which any application supported by that platform can use without concern for the details of how the functionality provided by the platform is implemented [5]. In principle a platform is a place to launch software on. Examples of platforms are operation systems, the Java Virtual Machine, runtime libraries of programming languages, etc. Platform Independence Platform independence is a quality, which a model may exhibit. This is the quality that the model is independent of the features of a platform of any particular type. Like most qualities, platform independence is a matter of degree. So, one model might only assume availability of features of a very general type of platform, such as remote invocation, while another model might assume the availability a particular set of tools for the CORBA platform. Likewise, one model might assume 11
Page 1 and 2: POLITECNICO DI MILANO V Facoltà di
Page 3 and 4: Table of Contents Abstract ........
Page 5 and 6: 1. Introduction At present the Web
Page 7 and 8: • Definition of the formal repres
Page 9: This approach overcomes the develop
Page 13 and 14: consists of a data schema, describi
Page 15 and 16: high-level business rules, written
Page 17 and 18: Thanks to the automatic generation
Page 19 and 20: 2.4.2 RDF Resource Description Fram
Page 21 and 22: Third, besides the aforementioned r
Page 23 and 24: The XMI serialization of UML [33] e
Page 25 and 26: 2.9.2.1 Pellet Pellet 1 [47] is an
Page 27 and 28: 3. Semantics Web based Recommendati
Page 29 and 30: them by invoking respectively the c
Page 31 and 32: etrieves the properties by their ca
Page 33 and 34: Figure 3.6: Instance Component 3.1.
Page 35 and 36: 3.1.8 Add Components The Add compon
Page 37 and 38: Add Class Component ClassDisjointOf
Page 39 and 40: PropertyDisjointOfProperty (for ins
Page 41 and 42: first-class citizens, we have more
Page 43 and 44: Figure 3.17: Remove Datatype Compon
Page 45 and 46: 3.1.19 Remove Instance component Th
Page 47 and 48: 3.2.4 Export-XMI-from-KB component
Page 49 and 50: 3.3.1.2 Properties of a class patte
Page 51 and 52: 3.3.1.5 Instances of a class assumi
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Page 55 and 56: 3.3.2.2 Remove property value for a
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Send Group Invitation Actor: Group
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A user can recommend friend as Frie
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In the figure 3.37, a User browsing
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Through the entry unit in figure 4.
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Figure 4.2: Example of WebML hypert
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Description Classes Hierarchy Unit
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Add PropertyValueAxiom Input: manda
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4.4. The top segment of the page is
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page otherwise it will go to the er
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We are showing current user’s inf
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current user is sending a friend in
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The information of a particular gro
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Figure 4.20: HTML view to Post New
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the application domain as extended
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Knowledge Instances Yes Yes Yes Yes
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OWL DL KB Framework CLASS HIERARCHI
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of a specific group members of the
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[22] OMG UML (2007), Unified Modeli
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[56] BRAMBILLA, M., CERI, S., FRATE
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