- About
-
The Global ETD Search service is a free service for researchers
to find electronic theses and dissertations. This service is
provided by the
Networked Digital Library of Theses and Dissertations.
Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
Search results
Showing 1 to 7 of 7 (0.016 seconds)| 1 |
Z formaliuju metodu panaudojimas informaciniu sistemu projektavime / The use of Z for informational systems designPaulauskaitė, Agnė 20 May 2005 (has links)
Summary
Still today informal methods are the most common for informational systems design. They don‘t allows unambiguously understand formulating tasks, moreover availably specifications not always are complete. Because of this informational system does not correspond to users needs. Using informal methods specification transformation to software code isn‘t always possible.
In real time informational systems problematic domain is varying in time. Thus are changing requirements for informational systems. Using informal methods, to solve this problem, usually we need to rewrite software. Using formal methods we don‘t have to rewrite software, it is enough organization business instructions specified in Z transform to software code.
In this paper we present research results about Z specification method use for formal requirements specification for informational systems design. Using Z/EVES - an interactive system for composing, checking, and analyzing Z specifications, was accomplished Z specification validation, theretofore reviewing the list of available Z specification validation tools. Z specification language was compared with object-oriented language Object–Z to find out advantages and disadvantages of these two formal specification languages. Were discussed questions about Z specification transformation to Object-Z, which facilities an object-oriented specification extension to object-oriented programming languages. In this paper transformation methodology from object-Z... [to full text]
|
| 2 |
Couplage de notations semi-formelles et formelles pour la spécification des systèmes d'informationDupuy, Sophie 22 September 2000 (has links) (PDF)
Les notations semi-formelles et formelles semblant complémentaires, leur couplage semble un cadre intéressant pour pouvoir bénéficier de leurs avantages respectifs tout en diminuant leurs points faibles. En effet, d'une part, les notations semi-formelles qui pêchent par leur précision sont de bons vecteurs de communication dont le coût de formation est raisonnable ; d'autre part, les langages formels apportent la précision et le potentiel de raisonnement manquant aux notations semi-formelles. Dans ce travail, nous proposons une approche de traduction de modèles semi-formels objet en des spécifications formelles en Z ou en Object-Z afin de fournir un couplage bénéfique de ces deux types de spécifications. Nous cherchons à rendre nos propositions les plus utilisables possible en en montrant trois bénéfices avérés : un guide méthodologique pour l'expression des contraintes annotant un modèle objet, une aide à la vérification des modèles et de leurs contraintes et des raisonnements informels sur la sémantique de modèles simples. Nous avons aussi développé un outil de support à notre approche, RoZ qui permet de faire cohabiter les notations semi-formelles et formelles. Enfin nous étudions une autre approche de couplage, la vérification de cohérence par méta-modélisation pour laquelle nous proposons des règles de cohérence entre le modèle objet et Z. Ce travail nous permet de comparer cette approche avec notre stratégie de traduction afin de mieux comprendre leurs avantages et leurs inconvénients.
|
| 3 |
Towards the formalisation of use case mapsDongmo, Cyrille 11 1900 (has links)
Formal specification of software systems has been very promising. Critics against the end
results of formal methods, that is, producing quality software products, is certainly rare. Instead,
reasons have been formulated to justify why the adoption of the technique in industry
remains limited. Some of the reasons are:
• Steap learning curve; formal techniques are said to be hard to use.
• Lack of a step-by-step construction mechanism and poor guidance.
• Difficulty to integrate the technique into the existing software processes.
Z is, arguably, one of the successful formal specification techniques that was extended to
Object-Z to accommodate object-orientation. The Z notation is based on first-order logic
and a strongly typed fragment of Zermelo-Fraenkel set theory. Some attempts have been
made to couple Z with semi-formal notations such as UML. However, the case of coupling
Object-Z (and also Z) and the Use Case Maps (UCMs) notation is still to be explored.
A Use Case Map (UCM) is a scenario-based visual notation facilitating the requirements
definition of complex systems. A UCM may be generated either from a set of informal
requirements, or from use cases normally expressed in natural language. UCMs have the
potential to bring more clarity into the functional description of a system. It may furthermore
eliminate possible errors in the user requirements. But UCMs are not suitable to reason
formally about system behaviour.
In this dissertation, we aim to demonstrate that a UCM can be transformed into Z and
Object-Z, by providing a transformation framework. Through a case study, the impact of
using UCM as an intermediate step in the process of producing a Z and Object-Z specification
is explored. The aim is to improve on the constructivity of Z and Object-Z, provide more
guidance, and address the issue of integrating them into the existing Software Requirements
engineering process. / Computer Science / M. Sc. (Computer Science)
|
| 4 |
Towards the formalisation of use case mapsDongmo, Cyrille 11 1900 (has links)
Formal specification of software systems has been very promising. Critics against the end
results of formal methods, that is, producing quality software products, is certainly rare. Instead,
reasons have been formulated to justify why the adoption of the technique in industry
remains limited. Some of the reasons are:
• Steap learning curve; formal techniques are said to be hard to use.
• Lack of a step-by-step construction mechanism and poor guidance.
• Difficulty to integrate the technique into the existing software processes.
Z is, arguably, one of the successful formal specification techniques that was extended to
Object-Z to accommodate object-orientation. The Z notation is based on first-order logic
and a strongly typed fragment of Zermelo-Fraenkel set theory. Some attempts have been
made to couple Z with semi-formal notations such as UML. However, the case of coupling
Object-Z (and also Z) and the Use Case Maps (UCMs) notation is still to be explored.
A Use Case Map (UCM) is a scenario-based visual notation facilitating the requirements
definition of complex systems. A UCM may be generated either from a set of informal
requirements, or from use cases normally expressed in natural language. UCMs have the
potential to bring more clarity into the functional description of a system. It may furthermore
eliminate possible errors in the user requirements. But UCMs are not suitable to reason
formally about system behaviour.
In this dissertation, we aim to demonstrate that a UCM can be transformed into Z and
Object-Z, by providing a transformation framework. Through a case study, the impact of
using UCM as an intermediate step in the process of producing a Z and Object-Z specification
is explored. The aim is to improve on the constructivity of Z and Object-Z, provide more
guidance, and address the issue of integrating them into the existing Software Requirements
engineering process. / Computer Science / M. Sc. (Computer Science) / D. Phil. (Computer Science)
|
| 5 |
From specification through refinement to implementation : a comparative studyVan Coppenhagen, Ingrid H. M. 30 June 2002 (has links)
This dissertation investigates the role of specification, refinement and implementation in the software development cycle. Both the structured and object-oriented paradigms are looked at. Particular emphasis is placed on the role of the refinement process.
The requirements for the product (system) are determined, the specifications are drawn up, the product is designed, specified, implemented and tested. The stage between the (formal) specification of the system and the implementation of the system is the refinement stage.
The refinement process consists out of data refinement, operation refinement, and operation decomposition. In this dissertation, Z, Object-Z and UML (Unified Modelling Language) are used as specification languages and C, C++, Cobol and Object-Oriented Cobol are used as implementation languages.
As an illustration a small system, The ITEM System, is specified in Z and UML and implemented in Object-Oriented Cobol. / Computing / M. Sc. (Information Systems)
|
| 6 |
Formalising non-functional requirements embedded in user requirements notation (URN) modelsDongmo, Cyrille 11 1900 (has links)
The growing need for computer software in different sectors of activity, (health, agriculture,
industries, education, aeronautic, science and telecommunication) together with the
increasing reliance of the society as a whole on information technology, is placing a heavy
and fast growing demand on complex and high quality software systems. In this regard, the
anticipation has been on non-functional requirements (NFRs) engineering and formal methods.
Despite their common objective, these techniques have in most cases evolved separately.
NFRs engineering proceeds firstly, by deriving measures to evaluate the quality of the constructed
software (product-oriented approach), and secondarily by improving the engineering
process (process-oriented approach). With the ability to combine the analysis of both functional
and non-functional requirements, Goal-Oriented Requirements Engineering (GORE)
approaches have become de facto leading requirements engineering methods. They propose
through refinement/operationalisation, means to satisfy NFRs encoded in softgoals at an
early phase of software development. On the other side, formal methods have kept, so far,
their promise to eliminate errors in software artefacts to produce high quality software products
and are therefore particularly solicited for safety and mission critical systems for which
a single error may cause great loss including human life.
This thesis introduces the concept of Complementary Non-functional action (CNF-action)
to extend the analysis and development of NFRs beyond the traditional goals/softgoals
analysis, based on refinement/operationalisation, and to propagate the influence of NFRs
to other software construction phases. Mechanisms are also developed to integrate the formal
technique Z/Object-Z into the standardised User Requirements Notation (URN) to
formalise GRL models describing functional and non-functional requirements, to propagate
CNF-actions of the formalised NFRs to UCMs maps, to facilitate URN construction process
and the quality of URN models. / School of Computing / D. Phil (Computer Science)
|
| 7 |
From specification through refinement to implementation : a comparative studyVan Coppenhagen, Ingrid H. M. 30 June 2002 (has links)
This dissertation investigates the role of specification, refinement and implementation in the software development cycle. Both the structured and object-oriented paradigms are looked at. Particular emphasis is placed on the role of the refinement process.
The requirements for the product (system) are determined, the specifications are drawn up, the product is designed, specified, implemented and tested. The stage between the (formal) specification of the system and the implementation of the system is the refinement stage.
The refinement process consists out of data refinement, operation refinement, and operation decomposition. In this dissertation, Z, Object-Z and UML (Unified Modelling Language) are used as specification languages and C, C++, Cobol and Object-Oriented Cobol are used as implementation languages.
As an illustration a small system, The ITEM System, is specified in Z and UML and implemented in Object-Oriented Cobol. / Computing / M. Sc. (Information Systems)
|
Page generated in 0.0282 seconds