No description available.

No description available.

Drasil is a framework for generating high-quality documentation and code for Scientific Computing Software (SCS). Despite the tendency of SCS code to follow an Input-Calculate-Output design pattern, there are many design variabilities in SCS. Drasil should therefore allow its users to specify a design for their generated program. To this end, a language that encodes the design variabilities present in SCS was implemented in Drasil. Drasil's code generator was updated to generate code based on a user's design choices. A Generic Object-Oriented Language, GOOL, from which Python, Java, C#, or C++ code can be generated, was implemented. Drasil's code generator targets GOOL, enabling the choice of programming language to be included in the design language. Other choices included in the language are related to the modularity, the generation of record classes to bundle variables, the inlining of constants, the code types used to represent different mathematical spaces, which external library to use to solve ODEs, the behaviour when a constraint is violated, and the presence of documentation, logging, or a controller. The design language is implemented as a record type in Haskell, and is designed to be understandable, extensible, and usable. A design specification can be easily changed, to generate a different version of the same program, which would often require time-consuming refactoring if the program was written manually. During the regular build process of Drasil, working code is generated in all four target languages for three examples of SCS, each using a different design specification. / Thesis / Master of Applied Science (MASc)

Engineers in diverse fields are able to model their design and experiment with that design to determine how it responds to the environment and how it satisfies the requirements. Design tools for software engineering have become standardized and matured to allow for formal definition of software design. This paper tests the current state of design documentation to determine the quality of design testing available at the early stage of software design. / text

The work described in this thesis falls under the umbrella of the Aurora project (Aurora 2000). Aurora is a long-term research project which, through diverse studies, investigates the potential enhancement of the everyday lives of children with autism through the use of robots, and other interactive systems, in playful contexts. Autism is a lifelong pervasive disability which affects social interaction and communication. Importantly for this thesis, children with autism exhibit a deficit in narrative comprehension which adversely impacts their social world. The research agenda addressed by this thesis was to develop an interactive software system which promotes an understanding of narrative structure (and thus the social world) while addressing the needs of individual children. The conceptual approach developed was to break down narrative into proto-narrative components and address these components individually through the introduction of simple game-like tasks, called t-stories, presented in a human-computer interaction context. The overarching hypothesis addressed was that it is possible to help children with autism to improve their narrative skills by addressing proto-narrative components independently. An interactive software system called TouchStory was developed to present t-stories to children with autism. Following knowledge of the characteristics and preferences of this group of learners TouchStory maintained strong analogies with the concrete, physical world. The design approach was to keep things simple, introducing features only if necessary to provide a focussed and enjoyable game. TouchStory uses a touch-sensitive screen as the interaction device as it affords immediate direct manipulation of the t-story components. Socially mediated methods of requirements elicitation and software evaluation (such as focus groups, thinking aloud protocols, or intergenerational design teams) are not appropriate for use with children with autism who are not socially oriented and, in the case of children with ‗lower functioning‘ autism, may have very few words or no productive language. Therefore a new strategy was developed to achieve an inclusive, child-centred design; this was to interleave prototype development with evaluation over several long-term trials. The trials were carried out in the participants‘ own school environments to provide an ecologically valid contextual enquiry. In the first trial 18 participants were each seen individually once. The second and third trials were extended studies of 12 and 20 school visits with 12 and 6 participants respectively; each participant was seen individually on each school visit, provided that the participant was at school on the day of the visit. Evaluation was carried out on the basis of video recordings of the sessions and software logs of the on-screen interactions. Individual learning needs were addressed by adapting the set of t-stories presented to the participant on the basis of success during recent sessions. No ordering of difficulty among the proto-narrative categories could be known a priori for any individual child, and may vary from child to child. Therefore the intention was to gradually, over multiple sessions, increase the proportion of t-stories from proto-narrative categories which the individual participant found challenging, while retaining sufficient scope for the expression of skills already mastered for the session to be enjoyable and rewarding. The adaptation of the software was achieved by introducing a simple adaptive formula, evaluating it over successive long terms trials, and increasing the complexity of the formula only where necessary. Results indicate that individual participants found the interactive presentation of the simple game-like tasks engaging, even after repeated exposures on as many as 20 occasions. The adaptive formula developed in this study did, for engaged participants, focus on the proto-narrative categories which the participant needed to practice but was likely to succeed; that is it did target an effective learning zone. While little evidence was seen of learning with respect to the fully developed narratives encountered in everyday life, results strongly suggest that some participants were actively engaged in self-directed, curiosity-driven activity that functioned as learning in that they were able to transfer knowledge about the appropriateness of particular responses to previously unseen t-stories. This thesis was driven by the needs of children with autism; contributions are made in a number of cognate areas. A conceptual contribution was made by the introduction of the proto-narrative concept which was shown to identify narrative deficits in children with autism and to form a basis for learning. A contribution was made to computational adaptation by the development of a novel adaptive formula which was shown to present a challenging experience while maintaining sufficient predictability and opportunities for the expression of skills already mastered to provide a comfortable experience for children with autism. A contribution was made to software development by showing that children with autism may be included in the design process through iterative development combined with long term trials. A contribution was made to assistive technology by demonstrating that simplicity together with evaluation over long term trials engages children with autism and is a route to inclusion. We cannot expect any magic fixes for children with autism, progress will be made by small steps; this thesis forms a small but significant contribution.

Enterprise information systems are increasingly being developed as distributed information systems. Quality attributes of distributed information systems, as in the centralised case, should be evaluated as early and as accurately as possible in the software engineering process. In particular, software measures associated with quality attributes of such systems should consider the characteristics of modern distributed technologies. Early design decisions have a deep impact on the implementation of distributed enterprise information systems and thus, on the ultimate quality of the software as an operational entity. Due to the fact that the distributed-software engineering process affords software engineers a number of design alternatives, it is important to develop tools and guidelines that can be used to assess and compare design artefacts quantitatively. This dissertation makes a contribution to the field of Software Engineering by proposing and evaluating software design measures for distributed enterprise information systems. In previous research, measures developed for distributed software have been focused in code attributes, and thus, only provide feedback towards the end of the software engineering process. In contrast, this thesis proposes a number of specific design measures that provide quantitative information before the implementation. These measures capture attributes of the structure and behaviour of distributed information systems that are deemed important to assess their quality attributes, based on the analysis of the problem domain. The measures were evaluated theoretically and empirically as part of a well defined methodology. On the one hand, we have followed a formal framework based on the theory of measurement, in order to carry out the theoretical validation of the proposed measures. On the other hand, the suitability of the measures, to be used as indicators of quality attributes, was evaluated empirically with a robust statistical technique for exploratory research. The data sets analysed were gathered after running several experiments and replications with a distributed enterprise information system. The results of the empirical evaluation show that most of the proposed measures are correlated to the quality attributes of interest, and that most of these measures may be used, individually or in combination, for the estimation of these quality attributes-namely efficiency, reliability and maintainability. The design of a distributed information system is modelled as a combination of its structure, which reflects static characteristics, and its behaviour, which captures complementary dynamic aspects. The behavioural measures showed slightly better individual and combined results than the structural measures in the experimentation. This was in line with our expectations, since the measures were evaluated as indicators of non-functional quality attributes of the operational system. On the other hand, the structural measures provide useful feedback that is available earlier in the software engineering process. Finally, we developed a prototype application to collect the proposed measures automatically and examined typical real-world scenarios where the measures may be used to make design decisions as part of the software engineering process.

As the pace of business change increases, service-oriented (SO) solutions should facilitate easier maintainability as underlying business logic and rules change. To date, little effort has been dedicated to considering how the structural properties of coupling and cohesion may impact on the maintainability of SO software products. Moreover, due to the unique design characteristics of Service-Oriented Computing (SOC), existing Procedural and Object-Oriented (OO) software metrics are not sufficient for the accurate measurement of service-oriented design structures. This thesis makes a contribution to the field of SOC, and Software Engineering in general, by proposing and evaluating a suite of design-level coupling and cohesion metrics for predicting the maintainability of service-oriented software products early in the Software Development LifeCycle (SDLC). The proposed metrics can provide the following benefits: i) facilitate design decisions that could lead to the specification of quality SO designs that can be maintained more easily; ii) identify design problems that can potentially have a negative effect on the maintainability of existing service-oriented design structures; and iii) support more effective control of maintainability in the earlier stages of SDLC. More specifically, the following research was conducted as part of this thesis: - A formal mathematical model covering the structural and behavioural properties of service-oriented system design was specified. - Software metrics were defined in a precise, unambiguous, and formal manner using the above model. - The metrics were theoretically validated and empirically evaluated in order to determine the success of this thesis as follows: a. Theoretical validation was based on the property-based software engineering measurement framework. All the proposed metrics were deemed as theoretically valid. b. Empirical evaluation employed a controlled experimental study involving ten participants who performed a range of maintenance tasks on two SO systems developed (and measured using the proposed metrics) specifically for this study. The majority of the experimental outcomes compared favourably with our expectations and hypotheses. More specifically, the results indicated that most of the proposed metrics can be used to predict the maintainability of service-oriented software products early in the SDLC, thereby providing evidence for the validity and potential usefulness of the derived metrics. Nevertheless, a broader range of industrial scale experiments and analyses are required to fully demonstrate the practical applicability of the metrics. This has been left to future work.

Manufacturing intelligent agent simulation has not been widely applied in industry because of its application complexity. This complexity, which includes choosing priority machines or jobs, determining machine maintenance schedules, and allocating working shifts and breaks, requires intelligent decision making. Manufacturing systems are strongly influenced by intelligent decision makers. Especially for a fixed manufacturing layout, system performance improvement depends on intelligent manufacturing decision making. As a result, a manufacturing simulation can not be truly complete if intelligent decision making processes are not represented. This thesis describes an architecture which includes the representation of intelligent agents in manufacturing simulation model. An intelligent agent simulation environment (IASE) is developed under the concepts of distributed artificial intelligence and object oriented methodology. As an extension to an existing simulation environment, IASE inherits primary manufacturing simulation elements and material handling systems from object oriented manufacturing architecture (Beaumariage, 1990) and AGV simulation system (Beaumariage and Wang, 1995). In IASE, production operators, maintenance technicians and job releasers are created to represent manufacturing intelligent agents. Several basic elements such as the blackboard structure and knowledge base for supporting intelligent agent simulation are also developed. In contrast to traditional simulation environments designed for and in procedural programming languages, future extensions or modifications for IASE are eased since IASE is developed in an object oriented fashion. This paper introduces IASE structure both in the conceptual design and implementation methodology levels. At the end, two case studies are performed. The first case study is to verify IASE's implementation and results by comparing it with a model developed in SLAM II. The second case study, a mixed intelligent agent decision making example, demonstrates the intelligent agent simulation ability of IASE. / Graduation date: 1997

Software designers make decisions between alternate approaches early in the development of a software application and these decisions can be difficult to change later. Designers make these decisions based on estimates of how alternatives affect software qualities. One software quality that can be difficult to predict is performance, that is, the efficient use of resources in the system. It is particularly challenging to estimate the performance of large, interconnected software systems composed of components. With the proliferation of class libraries, middle-ware systems, web services, and third party components, many software projects rely on third party services to meet their requirements. Often choosing between services involves considering both the functionality and performance of the services. To help software developers compare their designs and third-party services, I propose using performance prototypes of alternatives and test suites to estimate performance trade-offs early in the development cycle, a process called Design-Time Performance Testing (DTPT).<p> Providing software designers with performance evidence based on prototypes will allow designers to make informed decisions regarding performance trade-offs. To show how DTPT can help inform real design decisions. In particular: a process for DTPT, a framework implementation written in Java, and experiments to verify and validate the process and implementation. The implemented framework assists when designing, running, and documenting performance test suites, allowing designers to make accurate comparisons between alternate approaches. Performance metrics are captured by instrumenting and running prototypes.<p> This thesis describes the process and framework for gathering software performance estimates at design-time using prototypes and test suites.

Software designers make decisions between alternate approaches early in the development of a software application and these decisions can be difficult to change later. Designers make these decisions based on estimates of how alternatives affect software qualities. One software quality that can be difficult to predict is performance, that is, the efficient use of resources in the system. It is particularly challenging to estimate the performance of large, interconnected software systems composed of components. With the proliferation of class libraries, middle-ware systems, web services, and third party components, many software projects rely on third party services to meet their requirements. Often choosing between services involves considering both the functionality and performance of the services. To help software developers compare their designs and third-party services, I propose using performance prototypes of alternatives and test suites to estimate performance trade-offs early in the development cycle, a process called Design-Time Performance Testing (DTPT).<p> Providing software designers with performance evidence based on prototypes will allow designers to make informed decisions regarding performance trade-offs. To show how DTPT can help inform real design decisions. In particular: a process for DTPT, a framework implementation written in Java, and experiments to verify and validate the process and implementation. The implemented framework assists when designing, running, and documenting performance test suites, allowing designers to make accurate comparisons between alternate approaches. Performance metrics are captured by instrumenting and running prototypes.<p> This thesis describes the process and framework for gathering software performance estimates at design-time using prototypes and test suites.