A survey of compiler development aids

A theoretical background was established for the compilation process by dividing it into five phases and explaining the concepts and algorithms that underpin each. The five selected phases were lexical analysis, syntax analysis, semantic analysis, optimization, and code generation. Graph theoretical optimization techniques were presented, and approaches to code generation were described for both one-pass and multipass compilation environments. Following the initial tutorial sections, more than 20 tools that were developed to aid in the process of writing compilers were surveyed. Eight of the more recent compiler development aids were selected for special attention - SIMCMP/STAGE2, LANG-PAK, COGENT, XPL, AED, CWIC, LIS, and JOCIT. The impact of compiler development aids were assessed some of their shortcomings and some of the areas of research currently in progress were inspected

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

Gentleman : a lightweight web-based projectional editor

Lors de la conception et la manipulation de logiciel par modélisation, il est avantageux de bénéficier d’un grand degré de liberté au niveau de la présentation afin de comprendre l’information et prendre une action en exerçant peu d’effort cognitif et physique. Cette caractéristique doit aussi s’étendre aux outils que nous employons afin que ceux-ci augmentent nos capacités, plutôt que les restreindre. En génie logiciel, nous travaillons présentement à rehausser encore le niveau d’abstraction afin de réduire le rôle central du code décrit avec un langage de programmation à usage général. Ceci permettrait d’inclure les experts non techniques dans les activités de développement de logiciel. Cette approche, centralisée sur le domaine et l’expert, s’inscrit dans l’ingénierie dirigée par les modèles (IDM), où un modèle est produit et manipulé par divers experts et utilisateurs. Le modèle est alors décrit avec un langage créé spécifiquement pour un domaine d’application ou une tache, appelé langage dédié (DSL). Une technique utilisée pour créer ces modèles et leurs DSL est le projectional editing, qui permet d’utiliser des notations diverses interchangeables et d’étendre et composer facilement un langage. Toutefois, les solutions actuelles sont lourdes, spécifiques à une plateforme, et manquent considérablement d’utilisabilité, limitant ainsi l’usage et l’exploitation de cette approche. Pour mieux refléter les avantages du paradigme IDM avec le style projectionnel, nous introduisons dans cette thèse Gentleman, un éditeur projectionnel léger sur le web. Avec Gentleman, le développeur crée un modèle en combinant des concepts utilisés pour définir la structure du modèle et des projections pour les manipuler dans l’éditeur. Nous avons évalué Gentleman à travers une étude basée sur un groupe d’utilisateur. L’étude a confirmé sa capacité à créer et manipuler des modèles efficacement. Les participants ont noté qu’il est facile de prendre en main Gentleman et que l’interface est très intuitive comparativement aux éditeurs existants. Nous avons aussi intégré Gentleman avec succès à une plateforme web, démontrant ainsi ses capacités d’interopérabilité et l’avantage d’une solution web.In software activities and, more specifically, when modeling, the modeler should benefit from as much freedom as possible to understand the presented information and take action with minimal cognitive and mechanical effort. This characteristic should also apply to the tools used in the process so that they extend our capabilities rather than limit them. In the field of software engineering, current work aims to push the level of abstraction past general-purpose programming language into domain-specific modeling. This enables domain experts with various backgrounds to participate in software development activities. This vision is central to model-driven engineering (MDE) where, instead of code, various experts and users produce and manipulate domain-specific language (DSL). In recent years, projectional editing has proven to be a valid approach to creating and manipulating DSLs, as it supports various easily interchangeable notations and enables language extension and composition. However, current solutions are heavyweight, platform-specific, and suffer from poor usability. To better support this paradigm and minimize the risk of accidental complexity in terms of expressiveness, in this thesis, we introduce Gentleman, a lightweight web-based projectional editor. With Gentleman, a developer creates a model by combining concepts used to define its structure and projections to interact and manipulate them in the editor. We have evaluated Gentleman through a user study. The evaluation confirmed its capacity to create and manipulate models effectively. Most participants noted that the editor is very user-friendly and intuitive compared to existing editors. We have also successfully integrated Gentleman into a web application, demonstrating its interoperability and the benefit of a web solution

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

Design Concepts for Automating Maintenance Instructions

This research task was performed under the Technology for Readiness and Sustainment (TRS) contract (F33615-99-D-6001) for the Air Force Research Laboratory (AFRL), Sustainment Logistics Branch (HESS) at Wright-Patterson AFB, OH. The period of performance spanned one year starting 29 January 1999. The objective of this task was to develop and demonstrate a framework that can support the automated validation and verification of aircraft maintenance Technical Orders (TOs). The research team examined all stages ofTO generation to determine which tasks most warranted further research. From that investigation, validation and verification of appropriate, safe, and correct procedure steps emerged as the primary research target. This process would be based on available computer-aided design (CAD) data, procedure step ordering from existing sources, and human models. This determination was based on which tasks could yield the greatest impact on the authoring process and offer the greatest potential economic benefits. The team then developed a research roadmap and outlined specific technologies to be addressed in possible subsequent Air Force research tasks. To focus on the potential technology integration of the validation and verification component into existing or future TO generation procedures, we defined a demonstration scenario. Using the Front Uplock Hook assembly from an F/A-18 as the subject, we examined task procedure steps and failures that could be exposed by automated validation tools. These included hazards to personnel, damage to equipment, and incorrect disassembly order. Using the Parameterized Action Representation (PAR) developed on previous projects for actions and equipment behaviors, we characterized procedure steps and their positive and negative consequences. Finally, we illustrated a hypothetical user interface extension to a typical Interactive Electronic Technical Manual (IETM) authoring system to demonstrate how this process might appear to the TO author

Constructing 3D faces from natural language interface

This thesis presents a system by which 3D images of human faces can be constructed using a natural language interface. The driving force behind the project was the need to create a system whereby a machine could produce artistic images from verbal or composed descriptions. This research is the first to look at constructing and modifying facial image artwork using a natural language interface. Specialised modules have been developed to control geometry of 3D polygonal head models in a commercial modeller from natural language descriptions. These modules were produced from research on human physiognomy, 3D modelling techniques and tools, facial modelling and natural language processing. [Continues.

Any tool works if you are using the language: the role of knowledge in ICT integration in a Johannesburg private school

A research report submitted to the Wits School of Education, Faculty of Humanities, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements of the degree of Master of Education by combination of coursework and research. Johannesburg 2016Increasingly teachers are expected to integrate ICTs into their teaching practice. Recent studies have focused on the role played by teachers’ technological pedagogical content knowledge in explaining how they exploit the affordances offered by the new digital technologies, and yet the pace of integration has been far slower than expected. Education is founded on the business of knowledge, and yet there is a knowledge blindness in educational research. This study tries to discern what effect subject specialization and knowledge has on teacher’s adoption of ICTs into their pedagogical practice, using the framework of Legitimation Code Theory, in particular semantic waves. Seeing ICT practices as affording both knower and knowledge practices, and as affording gravitation or levitation allows us to start to unpack further how the forms knowledge takes influences decisions around ICT adoption.MT201

Baltic Journal of English Language, Literature and Culture, Vol.10

Kontorslokaler nyttjas generellt cirka 2500 av årets 8760 timmar. Ett vanligt problem med kontorslokaler är det termiska klimatet, antingen är det för varmt, för kallt, eller så drar det. Höga temperaturer, över ca 26°C, bidrar till trötthet, nedsatt koncentration och gör att luften känns mindre fräsch. Stora variationen av lasten mellan dag och nattetid kan också resultera i att lokalerna överventileras under nattetid och underventileras under dagtid. Syftet med examensarbetet var att undersöka och jämföra Ecoclimes komforttaks lösning med andra olika värme och kylsystem i kontorslokaler. Att undersöka vilka eventuella fördelar Ecoclimes komforttak har gällande komfort, kyla, ventilation och ur energisynpunkt. Simuleringsprogrammet IDA ICE har använts för att simulera komforten och rumstemperaturer för ett kontor och ett konferensrum i en byggnad placerad i centrala Umeå. Resultaten från simuleringar indikerar att Ecoclimes komforttak, sänker den operativa temperaturen och höjer komforten med en mindre andel missnöjda i sitt rum jämfört med andra system trots samma rumstemperatur. För att bedömma andelen missnöjda i ett rum har komfortindexet PMV(Predicted mean vote) och PPD(Predicted percentage dissatisfied) använts. Den höga passiva effekten bidrar också till mindre energianvändning av ventilationsfläktar ifall ett VAV-system med rumstempertaurreglering används. Vidare har en känslighetsanalys genomförts på komforttaken där det undersöks hur kyleffekten påverkar kyltider, temperatur och komfort. Känslighetsanalysen visar att en ökning eller minskning av kyleffekten med 10% påverkar resultaten mest under en mycket varm dag jämfört med en normalvarm. Skillnaden i komfort var dock liten, endast 0,2 procentenheter från grundfallet

Pattern-based segmentation of digital documents: model and implementation

This thesis proposes a new document model, according to which any document can be segmented in some independent components and transformed in a pattern-based projection, that only uses a very small set of objects and composition rules. The point is that such a normalized document expresses the same fundamental information of the original one, in a simple, clear and unambiguous way. The central part of my work consists of discussing that model, investigating how a digital document can be segmented, and how a segmented version can be used to implement advanced tools of conversion. I present seven patterns which are versatile enough to capture the most relevant documents’ structures, and whose minimality and rigour make that implementation possible. The abstract model is then instantiated into an actual markup language, called IML. IML is a general and extensible language, which basically adopts an XHTML syntax, able to capture a posteriori the only content of a digital document. It is compared with other languages and proposals, in order to clarify its role and objectives. Finally, I present some systems built upon these ideas. These applications are evaluated in terms of users’ advantages, workflow improvements and impact over the overall quality of the output. In particular, they cover heterogeneous content management processes: from web editing to collaboration (IsaWiki and WikiFactory), from e-learning (IsaLearning) to professional printing (IsaPress)