Expert systems for real-time monitoring and fault diagnosis

Methods for building real-time onboard expert systems were investigated, and the use of expert systems technology was demonstrated in improving the performance of current real-time onboard monitoring and fault diagnosis applications. The potential applications of the proposed research include an expert system environment allowing the integration of expert systems into conventional time-critical application solutions, a grammar for describing the discrete event behavior of monitoring and fault diagnosis systems, and their applications to new real-time hardware fault diagnosis and monitoring systems for aircraft

Pattern operators for grid

The definition and programming of distributed applications has become a major research issue due to the increasing availability of (large scale) distributed platforms and the requirements posed by the economical globalization. However, such a task requires a huge effort due to the complexity of the distributed environments: large amount of users may communicate and share information across different authority domains; moreover, the “execution environment” or “computations” are dynamic since the number of users and the computational infrastructure change in time. Grid environments, in particular, promise to be an answer to deal with such complexity, by providing high performance execution support to large amount of users, and resource sharing across different organizations. Nevertheless, programming in Grid environments is still a difficult task. There is a lack of high level programming paradigms and support tools that may guide the application developer and allow reusability of state-of-the-art solutions. Specifically, the main goal of the work presented in this thesis is to contribute to the simplification of the development cycle of applications for Grid environments by bringing structure and flexibility to three stages of that cycle through a commonmodel. The stages are: the design phase, the execution phase, and the reconfiguration phase. The common model is based on the manipulation of patterns through pattern operators, and the division of both patterns and operators into two categories, namely structural and behavioural. Moreover, both structural and behavioural patterns are first class entities at each of the aforesaid stages. At the design phase, patterns can be manipulated like other first class entities such as components. This allows a more structured way to build applications by reusing and composing state-of-the-art patterns. At the execution phase, patterns are units of execution control: it is possible, for example, to start or stop and to resume the execution of a pattern as a single entity. At the reconfiguration phase, patterns can also be manipulated as single entities with the additional advantage that it is possible to perform a structural reconfiguration while keeping some of the behavioural constraints, and vice-versa. For example, it is possible to replace a behavioural pattern, which was applied to some structural pattern, with another behavioural pattern. In this thesis, besides the proposal of the methodology for distributed application development, as sketched above, a definition of a relevant set of pattern operators was made. The methodology and the expressivity of the pattern operators were assessed through the development of several representative distributed applications. To support this validation, a prototype was designed and implemented, encompassing some relevant patterns and a significant part of the patterns operators defined. This prototype was based in the Triana environment; Triana supports the development and deployment of distributed applications in the Grid through a dataflow-based programming model. Additionally, this thesis also presents the analysis of a mapping of some operators for execution control onto the Distributed Resource Management Application API (DRMAA). This assessment confirmed the suitability of the proposed model, as well as the generality and flexibility of the defined pattern operatorsDepartamento de Informática and Faculdade de Ciências e Tecnologia of the Universidade Nova de Lisboa; Centro de Informática e Tecnologias da Informação of the FCT/UNL; Reitoria da Universidade Nova de Lisboa; Distributed Collaborative Computing Group, Cardiff University, United Kingdom; Fundação para a Ciência e Tecnologia; Instituto de Cooperação Científica e Tecnológica Internacional; French Embassy in Portugal; European Union Commission through the Agentcities.NET and Coordina projects; and the European Science Foundation, EURESCO

Pattern Operators for Grid Environments

The definition and programming of distributed applications has become a major research issue due to the increasing availability of (large scale) distributed platforms and the requirements posed by the economical globalization. However, such a task requires a huge effort due to the complexity of the distributed environments: large amount of users may communicate and share information across different authority domains; moreover, the “execution environment” or “computations” are dynamic since the number of users and the computational infrastructure change in time. Grid environments, in particular, promise to be an answer to deal with such complexity, by providing high performance execution support to large amount of users, and resource sharing across different organizations. Nevertheless, programming in Grid environments is still a difficult task. There is a lack of high level programming paradigms and support tools that may guide the application developer and allow reusability of state-of-the-art solutions. Specifically, the main goal of the work presented in this thesis is to contribute to the simplification of the development cycle of applications for Grid environments by bringing structure and flexibility to three stages of that cycle through a commonmodel. The stages are: the design phase, the execution phase, and the reconfiguration phase. The common model is based on the manipulation of patterns through pattern operators, and the division of both patterns and operators into two categories, namely structural and behavioural. Moreover, both structural and behavioural patterns are first class entities at each of the aforesaid stages. At the design phase, patterns can be manipulated like other first class entities such as components. This allows a more structured way to build applications by reusing and composing state-of-the-art patterns. At the execution phase, patterns are units of execution control: it is possible, for example, to start or stop and to resume the execution of a pattern as a single entity. At the reconfiguration phase, patterns can also be manipulated as single entities with the additional advantage that it is possible to perform a structural reconfiguration while keeping some of the behavioural constraints, and vice-versa. For example, it is possible to replace a behavioural pattern, which was applied to some structural pattern, with another behavioural pattern. In this thesis, besides the proposal of the methodology for distributed application development, as sketched above, a definition of a relevant set of pattern operators was made. The methodology and the expressivity of the pattern operators were assessed through the development of several representative distributed applications. To support this validation, a prototype was designed and implemented, encompassing some relevant patterns and a significant part of the patterns operators defined. This prototype was based in the Triana environment; Triana supports the development and deployment of distributed applications in the Grid through a dataflow-based programming model. Additionally, this thesis also presents the analysis of a mapping of some operators for execution control onto the Distributed Resource Management Application API (DRMAA). This assessment confirmed the suitability of the proposed model, as well as the generality and flexibility of the defined pattern operatorsDepartamento de Informática and Faculdade de Ciências e Tecnologia of the Universidade Nova de Lisboa; Centro de Informática e Tecnologias da Informação of the FCT/UNL; Reitoria da Universidade Nova de Lisboa; Distributed Collaborative Computing Group, Cardiff University, United Kingdom; Fundação para a Ciência e Tecnologia; Instituto de Cooperação Científica e Tecnológica Internacional; French Embassy in Portugal; European Union Commission through the Agentcities.NET and Coordina projects; and the European Science Foundation, EURESCO

Characterization of polysaccharide multilayered capsules for tissue engineering applications

Cell encapsulation has been widely studied as an alternative therapy for almost every human diseases and disorders. This technique enables the inclusion of various types of living cells inside spherical systems which, among other capabilities, mimic the environment provided by the extracellular matrix. This new therapeutic approach has already proved to be successful either in vitro or in vivo studies, thus becoming one of the most promising tools in tissue engineering and regenerative medicine. The main goal of this thesis was to explore some of the potential of cell encapsulation using simple and versatile techniques that can be performed in physiological and friendly conditions to the cells. In a first approach, cells were encapsulated in liquid-core capsules using a three step methodology: (i) the precipitation of a polymer solution of alginate into a bath of calcium chloride (ionotropic gelation), (ii) deposition of polyelectrolyte multilayers onto the surface of the beads, in a process called layer-by-layer. (iii) use of EDTA to liquefy the alginate core. Two different natural-based polymers were used, alginate, the most studied copolymer for cell encapsulation and chitosan, a polymer widely explored in a variety of biomedical applications. Both polymers were proved to be biocompatible, biodegradable and can be manipulated under physiological conditions. All the capsules produced exhibited spherical shape, smooth surface and liquid-core. The results shown that encapsulated cells were viable and proliferating few days after the alginate-chitosan multilayer buildup, which suggests that the develop capsules posses a semipermeable membrane which allows the correct diffusion of nutrients and metabolites. A preliminary study was started to test the feasibility of culturing anchorage-dependent cells in PLLA solid microparticles previously treated with human serum fibronectin followed by the encapsulation of the whole set in alginate-chitosan liquid-core capsules. The results are still very incipient but very promising

Contemporary Surface Architecture : The correspondence between surface and space

This thesis aims to investigate aspects of contemporary architecture that concentrate on the role of surface, in sense of demateriality. The word 'demateriality' denotes the spatiality rather than a physical substance; it does not refer to the actual absence of matter or the abolishment of the solid materials of construction. Rather it describes the phenomenal perception of a particular spatialisation that the surface creates through either the way it is formed or through the optical quality of its materials. The terms surface and surface architecture discussed in this thesis thus have specific meanings beyond the generally received understanding of 'architectural surface', 'material surface' and so on. What is focused on is the particular role of surface architecture as a spatial boundary, especially between inside and outside spaces. In this context, the research aims to explore the correspondence between the surface and space, between the forms of the surface and the experience that they induce. As a programme of PhD with design, this research includes both theoretical and practical approaches, including a design research project supported by an extensive literature review and theoretical argument. The thesis mainly consists of five parts. It begins from an Introduction including subject and questions, context, definition and methodology of the research. Chapter One is about a critical review of history of surface-space architecture, both in theory and design will be considered first. This will mainly focus on the architecture of 20th century modernism. Chapter Two focus on contemporary theories and practices of surface architecture, as well as the conception of surface in other intellectual areas such as philosophy and cultural theory. Based on a rigorous theoretical framework built by the historical and contemporary research, a series of design works will be developed in Chapter Three, and attempt to offer a further understanding and rethinking of the knowledge gained from the first phase. Finally, at the end of the thesis, there is a brief Conclusion