Semantics-driven dataflow diagram processing.

Dataflow diagram is a commonly used tool of structured analysis and design techniques in specifications and design of a software system, and in analysis of an existing system as well. While automatic generating dataflow diagram saves system designers from tedious drawing and help them develop a new system, simulating dataflow diagrams provides system analysts with a dynamic graph and help them understand an existing system. CASE tools for dataflow diagrams play an important role in software engineering. Methodologies applied to the tools are dominant issues extensively evaluated by tools designers. Executable specifications with dataflow diagrams turn out an opportunity to execute graphic dataflow diagrams for systems analysts to simulate the behavior of a system. In this thesis, a syntax representation of dataflow diagram was developed, and a formal specification for dataflow diagram was established. A parser of this developed CASE tool translates the syntax representation of DFDs into their semantic representation. An interpreter of this tool then analyzes the DFDs semantic notations and builds a set of services of a system represented by the DFDs. This CASE tool can be used to simulate system behavior, check equivalence of two systems and detect deadlock. Based on its features, this tool can be used in every phase through entire software life cycle. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1998 .Z46. Source: Masters Abstracts International, Volume: 39-02, page: 0535. Adviser: Indra A. Tjandra. Thesis (M.Sc.)--University of Windsor (Canada), 1998

Formalizing graphical notations

The thesis describes research into graphical notations for software engineering, with a principal interest in ways of formalizing them. The research seeks to provide a theoretical basis that will help in designing both notations and the software tools that process them. The work starts from a survey of literature on notation, followed by a review of techniques for formal description and for computational handling of notations. The survey concentrates on collecting views of the benefits and the problems attending notation use in software development; the review covers picture description languages, grammars and tools such as generic editors and visual programming environments. The main problem of notation is found to be a lack of any coherent, rigorous description methods. The current approaches to this problem are analysed as lacking in consensus on syntax specification and also lacking a clear focus on a defined concept of notated expression. To address these deficiencies, the thesis embarks upon an exploration of serniotic, linguistic and logical theory; this culminates in a proposed formalization of serniosis in notations, using categorial model theory as a mathematical foundation. An argument about the structure of sign systems leads to an analysis of notation into a layered system of tractable theories, spanning the gap between expressive pictorial medium and subject domain. This notion of 'tectonic' theory aims to treat both diagrams and formulae together. The research gives details of how syntactic structure can be sketched in a mathematical sense, with examples applying to software development diagrams, offering a new solution to the problem of notation specification. Based on these methods, the thesis discusses directions for resolving the harder problems of supporting notation design, processing and computer-aided generic editing. A number of future research areas are thereby opened up. For practical trial of the ideas, the work proceeds to the development and partial implementation of a system to aid the design of notations and editors. Finally the thesis is evaluated as a contribution to theory in an area which has not attracted a standard approach

Surface interaction : separating direct manipulation interfaces from their applications.

To promote both quality and economy in the production of applications and their interactive interfaces, it is desirable to delay their mutual binding. The later the binding, the more separable the interface from its application. An ideally separated interface can factor tasks from a range of applications, can provide a level of independence from hardware I/O devices, and can be responsive to end-user requirements. Current interface systems base their separation on two different abstractions. In linguistic architectures, for example User Interface Management Systems in the Seeheim model, the dialogue or syntax of interaction is abstracted in a separate notation. In agent architectures like Toolkits, interactive devices, at various levels of complexity, are abstracted into a class or call hierarchy. This Thesis identifies an essential feature of the popular notion of direct manipulation: directness requires that the same object be used both for output and input. In practice this compromises the separation of both dialogue and devices. In addition, dialogue cannot usefully be abstracted from its application functionality, while device abstraction reduces the designer's expressive control by binding presentation style to application semantics. This Thesis proposes an alternative separation, based on the abstraction of the medium of interaction, together with a dedicated user agent which allows direct manipulation of the medium. This interactive medium is called the surface. The Thesis proposes two new models for the surface, the first of which has been implemented as Presenter, the second of which is an ideal design permitting document quality interfaces. The major contribution of the Thesis is a precise specification of an architecture (UMA), whereby a separated surface can preserve directness without binding in application semantics, and at the same time an application can express its semantics on the surface without needing to manage all the details of interaction. Thus UMA partitions interaction into Surface Interaction, and deep interaction. Surface Interaction factors a large portion of the task of maintaining a highly manipulable interface, and brings the roles of user and application designer closer