Progressing problems from requirements to specifications in problem frames

One of the problems with current practice in software development is that often customer requirements are not well captured, understood and analysed, and there is no clear traceable path from customer requirements to software specifications. This often leads to a mismatch between what the customer needs and what the software developer understands the customer needs. In addition to capturing, understanding and analysing requirements, requirements engineering (RE) aims to provide methods to allow software development practitioners to derive software specifications from requirements. Although work exists towards this aim, the systematic derivation of specifications from requirements is still an open problem. This thesis provides practical techniques to implement the idea of problem progression as the basis for transforming requirements into specifications. The techniques allow us to progress a software problem towards identifying its solution by carefully investigating the problem context and re-expressing the requirement statement until a specification is reached. We develop two classes of progression techniques, one formal, based on Hoare’s Communicating Sequential Processes (CSP), and one semi-formal, based on a notion of causality between events. The case studies in this thesis provide some validation for the techniques we have developed

Applications of CSP solving in computer games (camera control)

While camera control systems of commercial 3D games have improved greatly in recent years, they are not as fully developed as are other game components such as graphics and physics engines. Bourne and Sattar (2006) have proposed a reactive constraint based third person perspective camera control system. We have extended the capability of their system to handle occlusion while following the main character, and have used camera cuts to find appropriate camera positions for a few difficult situations. We have developed a reactive constraint based third person perspective chase camera control system to follow a character in a 3D environment. The camera follows the character from (near) optimal positions defined by a camera profile. The desired values of the height and distance constraints of the camera profile are changed appropriately whenever the character enters a semi-enclosed or an enclosed area, and the desired value of the orientation constraint of the camera profile is changed incrementally whenever theoptimal camera view is obstructed. Camera cuts are used whenever the main character backs up to a wall or any other obstructions, or comes out of a semi-enclosed or an enclosed area. Two auxiliary cameras to observe the main camera positions from top and side views have been added. The chase camera control system achieved real-time performance while following the main character in a typical 3D environment, and maintained an optimal view based on a user specified/selected camera profile

KNOWLEDGE-BASED APPROACH FOR THE FORMATION OF RE-CONFIGURABLE ASSEMBLY CELLS-A USE CASE STUDY

The current market turbulence has forced the companies to increase their productivity in order to remain in business, not only to remain competitive. Companies that make high volume products involving labour-intensive assembly operation normally use automated assembly since it may reduce the company cost and increase productivity. Improving productivity is focused in the assembly area since it contributes a bigger portion of manufacturing cos

Declarative modeling based on knowledge

Les nouvelles technologies de l'image 3D permettent la création de mondes virtuels et des créatures qui les peuplent avec un tel niveau de détails, que pour les effets spéciaux de cinéma, il est difficile de distinguer les éléments sont générés par ordinateur. Cependant, cette technologie est dans les mains habiles de designers, artistes et programmeurs, pour lesquels il faut des semaines à plusieurs années pour se former aux outils et obtenir ces résultats. La Modélisation Déclarative est une méthode qui permet de créer des modèles en fournissant les propriétés donnant la description des composants du modèle. Appliquée à l’infographie, la modélisation déclarative est utilisée pour générer le monde virtuel, en déterminant le contexte nécessaire à l'animation et à la conception de la scène, en calculant la position de chaque objet relativement aux relations spatiales, et en générant le rendu de la scène, utilisé par une système d'animation et de visualisation. Ce mémoire présente les travaux de recherche consacrés à l'utilisation de la modélisation déclarative pour créer des environnements virtuels, en tirant partie des connaissances sur le contexte de la scène. Les connaissances sont utilisées afin de faciliter la tâche de description, en automatisant ce qui peut être déduit, comme les usages et les fonctionnalités habituelles. Elles sont également fondamentales pour que le résultat produit corresponde le mieux possible à ce qui est attendu par le concepteur à partir de la description fournie. Les connaissances sont enfin nécessaires pour faciliter la transition entre le modèle de données et l'architecture qui aura la charge d'animer et de faire évoluer la scène.Modern technology has allowed the creation and presentation or VirtualWorlds and creatures with such a high level of detail, that when used in movies, sometimes it is difficult to tell which elements arecomputer-generated and which not. Also, video-games had reached a level close to photographicrealism. However, such technology is at the hands of skillful designer, artists, and programmers, for whom ittakes from weeks to years to complete these results.Declarative modeling is a method which allows to create models specifying just a few properties for the model’s components. Applied to VW creation, declarative modeling can be used to construct theVW, establishing the layout for the objects, generating the necessary context to provide animation and scene design, and generate the outputs used by a visualization/animation system.This document present a research devoted to explore the use of declarative modeling to create VirtualEnvironments, using knowledge exploitation to support the process and ease the transition from the data model to an underlaying architecture which take the task of animating and evolving the scene

Using formal methods to support testing

Formal methods and testing are two important approaches that assist in the development of high quality software. While traditionally these approaches have been seen as rivals, in recent years a new consensus has developed in which they are seen as complementary. This article reviews the state of the art regarding ways in which the presence of a formal specification can be used to assist testing