An Integrated Formal Task Specification Method for Smart Environments

This thesis is concerned with the development of interactive systems for smart environments. In such scenario different interaction paradigms need to be supported and according methods and development strategies need to be applied to comprise not only explicit interaction (e.g., pressing a button to adjust the light) but also implicit interactions (e.g., walking to the speaker’s desk to give a talk) to assist the user appropriately. A task-based modeling approach is introduced allowing basing the implementing of different interaction paradigms on the same artifact

Recent advances in petri nets and concurrency

CEUR Workshop Proceeding

Composition and Declassification in Possibilistic Information Flow Security

Formal methods for security can rule out whole classes of security vulnerabilities, but applying them in practice remains challenging. This thesis develops formal verification techniques for information flow security that combine the expressivity and scalability strengths of existing frameworks. It builds upon Bounded Deducibility (BD) Security, which allows specifying and verifying fine-grained policies about what information may flow when to whom. Our main technical result is a compositionality theorem for BD Security, providing scalability by allowing us to verify security properties of a large system by verifying smaller components. Its practical utility is illustrated by a case study of verifying confidentiality properties of a distributed social media platform. Moreover, we discuss its use for the modular development of secure workflow systems, and for the security-preserving enforcement of safety and security properties other than information flow control

Automatic generation of user interfaces from rigorous domain and use case models

Tese de doutoramento. Engenharia Informática. Faculdade de Engenharia. Universidade do Porto. 201

Evolutionary design assistants for architecture

In its parallel pursuit of an increased competitivity for design offices and more pleasurable and easier workflows for designers, artificial design intelligence is a technical, intellectual, and political challenge. While human-machine cooperation has become commonplace through Computer Aided Design (CAD) tools, a more improved collaboration and better support appear possible only through an endeavor into a kind of artificial design intelligence, which is more sensitive to the human perception of affairs. Considered as part of the broader Computational Design studies, the research program of this quest can be called Artificial / Autonomous / Automated Design (AD). The current available level of Artificial Intelligence (AI) for design is limited and a viable aim for current AD would be to develop design assistants that are capable of producing drafts for various design tasks. Thus, the overall aim of this thesis is the development of approaches, techniques, and tools towards artificial design assistants that offer a capability for generating drafts for sub-tasks within design processes. The main technology explored for this aim is Evolutionary Computation (EC), and the target design domain is architecture. The two connected research questions of the study concern, first, the investigation of the ways to develop an architectural design assistant, and secondly, the utilization of EC for the development of such assistants. While developing approaches, techniques, and computational tools for such an assistant, the study also carries out a broad theoretical investigation into the main problems, challenges, and requirements towards such assistants on a rather overall level. Therefore, the research is shaped as a parallel investigation of three main threads interwoven along several levels, moving from a more general level to specific applications. The three research threads comprise, first, theoretical discussions and speculations with regard to both existing literature and the proposals and applications of the thesis; secondly, proposals for descriptive and prescriptive models, mappings, summary illustrations, task structures, decomposition schemes, and integratory frameworks; and finally, experimental applications of these proposals. This tripartite progression allows an evaluation of each proposal both conceptually and practically; thereby, enabling a progressive improvement of the understanding regarding the research question, while producing concrete outputs on the way. Besides theoretical and interpretative examinations, the thesis investigates its subject through a set of practical and speculative proposals, which function as both research instruments and the outputs of the study. The first main output of the study is the “design_proxy” approach (d_p), which is an integrated approach for draft making design assistants. It is an outcome of both theoretical examinations and experimental applications, and proposes an integration of, (1) flexible and relaxed task definitions and representations (instead of strict formalisms), (2) intuitive interfaces that make use of usual design media, (3) evaluation of solution proposals through their similarity to given examples, and (4) a dynamic evolutionary approach for solution generation. The design_proxy approach may be useful for AD researchers that aim at developing practical design assistants, as has been examined and demonstrated with the two applications, i.e., design_proxy.graphics and design_proxy.layout. The second main output, the “Interleaved Evolutionary Algorithm” (IEA, or Interleaved EA) is a novel evolutionary algorithm proposed and used as the underlying generative mechanism of design_proxybased design assistants. The Interleaved EA is a dynamic, adaptive, and multi-objective EA, in which one of the objectives leads the evolution until its fitness progression stagnates; in the sense that the settings and fitness values of this objective is used for most evolutionary decisions. In this way, the Interleaved EA enables the use of different settings and operators for each of the objectives within an overall task, which would be the same for all objectives in a regular multi-objective EA. This property gives the algorithm a modular structure, which offers an improvable method for the utilization of domain-specific knowledge for each sub-task, i.e., objective. The Interleaved EA can be used by Evolutionary Computation (EC) researchers and by practitioners who employ EC for their tasks. As a third main output, the “Architectural Stem Cells Framework” is a conceptual framework for architectural design assistants. It proposes a dynamic and multi-layered method for combining a set of design assistants for larger tasks in architectural design. The first component of the framework is a layer-based, parallel task decomposition approach, which aims at obtaining a dynamic parallelization of sub-tasks within a more complicated problem. The second component of the framework is a conception for the development mechanisms for building drafts, i.e., Architectural Stem Cells (ASC). An ASC can be conceived as a semantically marked geometric structure, which contains the information that specifies the possibilities and constraints for how an abstract building may develop from an undetailed stage to a fully developed building draft. ASCs are required for re-integrating the separated task layers of an architectural problem through solution-based development. The ASC Framework brings together many of the ideas of this thesis for a practical research agenda and it is presented to the AD researchers in architecture. Finally, the “design_proxy.layout” (d_p.layout) is an architectural layout design assistant based on the design_proxy approach and the IEA. The system uses a relaxed problem definition (producing draft layouts) and a flexible layout representation that permits the overlapping of design units and boundaries. User interaction with the system is carried out through intuitive 2D graphics and the functional evaluations are performed by measuring the similarity of a proposal to existing layouts. Functioning in an integrated manner, these properties make the system a practicable and enjoying design assistant, which was demonstrated through two workshop cases. The d_p.layout is a versatile and robust layout design assistant that can be used by architects in their design processes

Theory-based knowledge acquisition for ontology development

This thesis concerns the problem of knowledge acquisition in ontology development. Knowledge acquisition is essential for developing useful ontologies but it is a complex and error-prone task. When capturing specific knowledge about a particular domain of interest, the problem of knowledge acquisition occurs due to linguistic, cognitive, modelling, and methodical difficulties. For overcoming these four difficulties, this research proposes a theory-based knowledge acquisition method. By studying the knowledge base, basic terms and concepts in the areas of ontology, ontology development, and knowledge acquisition are defined. A theoretical analysis of knowledge acquisition identifies linguistic, cognitive, modelling, and methodical difficulties, for which a survey of 15 domain ontologies provides further empirical evidence. A review of existing knowledge acquisition approaches shows their insufficiencies for reducing the problem of knowledge acquisition. As the underpinning example, a description of the domain of transport chains is provided. Correspondingly, a theory in business economics, i.e. the Contingency Approach, is selected. This theory provides the key constructs, relationships, and dependencies that can guide knowledge acquisition in the business domain and, thus, theoretically substantiate knowledge acquisition. Method construction uses an approach from the field of Method Engineering, which defines how to develop a tailored method with respect to specific requirements on method design, functionality, components, and the underlying assumptions. The development of the method for theory-based knowledge acquisition covers the specification of the (method and outcome) metamodel, activity model, outcomes, roles, and techniques. The evaluation comprises two descriptive approaches to demonstrate the proposed methods utility. First, a criteria-based approach evaluates the method with respect to design-related, functional, and component-related requirements. Second, a scenario-based evaluation applies the method within a scenario from the domain of intermodal transport chains for acquiring knowledge to build a domain ontology. The contribution of this research is a theory-based knowledge acquisition method for ontology development. The application and usefulness of this method is demonstrated for a particular domain (transport chains) and uses a particular theory of business economics (the Contingency Approach).Diese Arbeit befasst sich mit dem Problem der Wissensakquisition in der Ontologieentwicklung. Die Wissensakquisition ist von zentraler Bedeutung für die Entwicklung nützlicher Ontologien. Sie stellt jedoch eine komplexe und fehleranfällige Aufgabe dar. Bei der Akquisition von spezifischem Wissen über eine bestimmte Domäne tritt das Problem der Wissensakquisition in Form von linguistischen, kognitiven, modellbildenden und methodischen Schwierigkeiten auf. Um diese vier Schwierigkeiten zu überwinden entwickelt diese Arbeit eine Methode für die theorie-basierte Wissensakquisition. Die Untersuchung des Stands der Forschung beginnt mit der Definition der grundlegenden Begriffe und Konzepte aus den Bereichen Ontologien, Ontologieentwicklung und Wissensakquisition sowie der Darlegung dazugehöriger Annahmen. Nachfolgend wird das Problem der Wissensakquisition analysiert und die identifizierten linguistischen, kognitiven, modellbildenden und methodischen Schwierigkeiten charakterisiert. Die Bedeutung dieser Schwierigkeiten wird durch eine empirische Untersuchung von 15 Ontologien für die Domäne Transportlogistik nachgewiesen. Die Offenlegung der Forschungslücke erfolgt durch die Analyse bestehender Ansätze zur Wissensakquisition und deren Bewertung hinsichtlich des Problems der Wissensakquisition. Basierend auf der identifizierten Forschungslücke wird die Theorie-basierte Wissensakquisition für die Ontologieentwicklung als Lösungsansatz vorgeschlagen. Die Erhebung der Anforderungen als Basis der Gestaltung des Lösungsansatzes wird anhand des Beispiels der Domäne der Transportlogistik vorgenommen. Hierfür werden zunächst die charakteristischen Merkmale der Transportlogistik herausgearbeitet. Auf Grundlage dessen erfolgt die Untersuchung betriebswirtschaftlicher Theorien, d.h. von Organisationstheorien, die Modelle mit Wissen über die betrachtete Domäne in Form der zentralen Konstrukte, (Wechsel-)Beziehungen und Abhängigkeiten bereitstellen. Als Ergebnis der Analyse werden der Situative Ansatz und das ihm zugrundeliegende Modell ausgewählt. Dieses Modell dient als Basis für die Ableitung der Anforderungen und ist somit als Fundament der Theorie-basierten Wissensakquisition. Die Gestaltung der Methode zur Theorie-basierten Wissensakquisition beruht auf einem Konstruktionsansatz aus dem Bereich des Method Engineering. Dieser Ansatz erlaubt es, auf bestimmte Zwecke zugeschnitte Methoden entsprechend den Anforderungen und den dazugehörigen Annahmen zu gestalten. Die Definition der Anforderungen umfasst das Design, die Funktionalität und die Komponenten der Methode. Die Spezifikation der Theorie-basierten Wissens-akquisitionsmethode beinhaltet zwei Metamodelle als Grundlage zur Definition der Methode und deren Ergebnissen, ein Aktivitätsmodell zur Festlegung der Aktivitäten, die Definition der Ergebnisse dieser Aktivitäten sowie die zur Ausführung und Unterstützung der Wissensakquisition notwendigen Rollen und Techniken. Zur Evaluation der Nützlichkeit der entwickelten Wissensakquisitionsmethode werden die in Frage kommenden Evaluationsansätze auf Eignung und Anwendbarkeit untersucht. Als Ergebnis werden zwei deskriptive Ansätze merkmals-basierte und szenario-basierte Evaluation ausgewählt. Die merkmals-basierte Evaluation erfolgt im Hinblick auf Kriterien der gestaltungsorientierten Wirtschaftsinformatik-Forschung sowie den Anforderungen an das Design, der Funktionalität und Komponenten der Methode. In der szenario-basierten Evaluation wird ein Szenario der intermodalen Transportlogistik definiert, auf welches die Wissensakquisitionsmethode für die Entwicklung der Domänen-Ontologie angewendet wird. Der Beitrag der vorliegenden Arbeit ist eine Methode zur Theorie-basierten Wissens-akquisition für die Ontologieentwicklung mit dem Ziel, das Problem der Wissensakquisition, d.h. den damit einhergehenden linguistischen, kognitiven, modellbildenden und methodischen Schwierigkeiten entgegenzuwirken. Die Gestaltung und Evaluation dieser Methode erfolgt anhand der Domäne Transportlogistik und des Situativen Ansatzes als betriebs-wirtschaftliche Theorie. Die Arbeit zeigt die Nützlichkeit der Verwendung betriebswirtschaftlicher Theorien zur Verbesserung der Wissensakquisition für die Ontologieentwicklung

A visual analytics approach to feature discovery and subspace exploration in protein flexibility matrices

The vast amount of information generated by domain scientists makes the transi- tion from data to knowledge difficult and often impedes important discoveries. For example, the knowledge gained from protein flexibility data sets can speed advances in genetic therapies and drug discovery. However, these models generate so much data that large scale analysis by traditional methods is almost impossible. This hinders biomedical advances. Visual analytics is a new field that can help alleviate this problem. Visual analytics attempts to seamlessly integrate human abilities in pattern recognition, domain knowledge, and synthesis with automatic analysis techniques. I propose a novel, visual analytics pipeline and prototype which eases discovery, com- parison, and exploration in the outputs of complex computational biology datasets. The approach utilizes automatic feature extraction by image segmentation to locate regions of interest in the data, visually presents the features to users in an intuitive way, and provides rich interactions for multi-resolution visual exploration. Functional- ity is also provided for subspace exploration based on automatic similarity calculation and comparative visualizations. The effectiveness of feature discovery and subspace exploration is shown through a user study and user scenarios. Feedback from analysts confirms the suitability of the proposed solution to domain tasks