Developing a distributed electronic health-record store for India

The DIGHT project is addressing the problem of building a scalable and highly available information store for the Electronic Health Records (EHRs) of the over one billion citizens of India

Two Steps Towards Kairos-Awareness

This thesis describes a research inspired by a concept of the classical discipline of rhetoric: kairos, the right moment to deliver a message in order to maximize its effect. The research followed two threads that, ultimately, lead to the same ending: the maximization of the potential of technology to deliver the right interaction at the right time. The first research thread is an operationalization of the concept of kairos. It entailed the development of EveWorks and EveXL, a framework for capturing daily life events in mobile devices and a domain-specific language to express them, respectively. The largely extended use of mobile devices and their proximity with their owners offers exceptional potential for capturing opportunity for interaction. Leveraging on this potential, the EveWorks-EveXL dyad was developed to allow mobile application programmers to specify the precise delivery circumstances of an interaction in order to maximize its potential, i.e., to specify its kairos. Contrasting to most event processing engines found in the literature that implement data-based event models, the EveWorks-EveXL dyad proposes a model based on temporality, through the articulation of intervals of time. This is a more natural way of representing a concept as broad as “daily life events” since, across cultures, temporal concepts like duration and time intervals are fundamental to the way people make sense of their experience. The results of the present work demonstrate that the EveWorks-EveXL dyad makes for an adequate and interesting way to express contextual events, in a way that is “closer” to our everyday understanding of daily life. Ultimately, in user centered applications, kairos can be influenced by the user’s emotional state, thereby making emotion assessment relevant. Addressing this, as well as the growing interest in the topic of emotions by the scientific community, the second research thread of the present thesis led to the development of the CAAT, a widget designed to perform quick and reliable assessments of affective states – a paramount task in a variety of scientific fields, including HCI. While there are already a number of tools for this purpose, in psychology, emotion assessments are largely conducted through the use of pen-and-paper questionnaires applied after the affective experience has occurred. As emotional states vary significantly over time, this entails the loss of important details, warranting the need for immediate, in situ, measurements of affect. In line with this requirement, the CAAT enables quick emotion assessment in a reliable fashion, as attested by the results of then validation studies conducted in order to assess its overall viability along relevant dimensions of usability and psychometrics. As such, aside from being a good fit for longitudinal studies and applications whenever the quick assessment of emotions is required, the CAAT has the potential to be integrated as one of EveWorks’ sensors to enhance its ability to find that sometimes elusive opportunity for interaction, i.e., their kairos. In this way, it becomes apparent how the two threads of research of the current work may be intertwined into a consolidated contribution to the HCI field

MORPH: A Reference Architecture for Configuration and Behaviour Self-Adaptation

An architectural approach to self-adaptive systems involves runtime change of system configuration (i.e., the system's components, their bindings and operational parameters) and behaviour update (i.e., component orchestration). Thus, dynamic reconfiguration and discrete event control theory are at the heart of architectural adaptation. Although controlling configuration and behaviour at runtime has been discussed and applied to architectural adaptation, architectures for self-adaptive systems often compound these two aspects reducing the potential for adaptability. In this paper we propose a reference architecture that allows for coordinated yet transparent and independent adaptation of system configuration and behaviour

A model-based approach for automatic recovery from memory leaks in enterprise applications

Large-scale distributed computing systems such as data centers are hosted on heterogeneous and networked servers that execute in a dynamic and uncertain operating environment, caused by factors such as time-varying user workload and various failures. Therefore, achieving stringent quality-of-service goals is a challenging task, requiring a comprehensive approach to performance control, fault diagnosis, and failure recovery. This work presents a model-based approach for fault management, which integrates limited lookahead control (LLC), diagnosis, and fault-tolerance concepts that: (1) enables systems to adapt to environment variations, (2) maintains the availability and reliability of the system, (3) facilitates system recovery from failures. We focused on memory leak errors in this thesis. A characterization function is designed to detect memory leaks. Then, a LLC is applied to enable the computing system to adapt efficiently to variations in the workload, and to enable the system recover from memory leaks and maintain functionality

Engineering framework for service-oriented automation systems

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

Architecture of a pan-European framework for Integrated Soil Water Erosion Assessment

Soil erosion implications on future food security are gaining global attention because in many areas worldwide there is an imbalance between soil loss and its subsequent deposition. Soil erosion is a complex phenomenon affected by many factors such as climate, topography and land cover (in particular forest resources, natural vegetation and agriculture) while directly influencing water sediment transport, the quality of water resources and water storage loss. A modeling architecture, based on the Revised Universal Soil Loss Equation, is proposed and applied to evaluate and validate at regional scale potential and actual soil water erosion, enabling it to be linked to other involved natural resources. The methodology benefits from the array programming paradigm with semantic constraints (lightweight array behavioural contracts provided by the Mastrave library) to concisely implement models as composition of interoperable modules and to process heterogeneous data.JRC.H.3-Forest Resources and Climat

Dynamic reconfiguration of GCM components

We detail in this report past research and current/future developments in formal specification of Grid component systems by temporal logic and consequent resolution technique, for an automated dynamic reconfiguration of components. It is analysed the specification procedure of GCM (Grid Component Model) components and infrastructure in respect to their state behaviour, and the verification process in a dynamic and reconfigurable distributed system. Furthermore it is demonstrated how an automata based method is used to achieve the specification, as well as how the enrichment of the temporal specification language of Computation Tree Logic CTL with the ability to capture norms, allows to formally define the concept of reconfiguration

Computing homomorphic program invariants

Program invariants are properties that are true at a particular program point or points. Program invariants are often undocumented assertions made by a programmer that hold the key to reasoning correctly about a software verification task. Unlike the contemporary research in which program invariants are defined to hold for all control flow paths, we propose \textit{homomorphic program invariants}, which hold with respect to a relevant equivalence class of control flow paths. For a problem-specific task, homomorphic program invariants can form stricter assertions. This work demonstrates that the novelty of computing homomorphic program invariants is both useful and practical. Towards our goal of computing homomorphic program invariants, we deal with the challenge of the astronomical number of paths in programs. Since reasoning about a class of program paths must be efficient in order to scale to real-world programs, we extend prior work to efficiently divide program paths into equivalence classes with respect to control flow events of interest. Our technique reasons about inter-procedural paths, which we then use to determine how to modify a program binary to abort execution at the start of an irrelevant program path. With off-the-shelf components, we employ the state-of-the-art in fuzzing and dynamic invariant detection tools to mine homomorphic program invariants. To aid in the task of identifying likely software anomalies, we develop human-in-the-loop analysis methodologies and a toolbox of human-centric static analysis tools. We present work to perform a statically-informed dynamic analysis to efficiently transition from static analysis to dynamic analysis and leverage the strengths of each approach. To evaluate our approach, we apply our techniques to three case study audits of challenge applications from DARPA\u27s Space/Time Analysis for Cybersecurity (STAC) program. In the final case study, we discover an unintentional vulnerability that causes a denial of service (DoS) in space and time, despite the challenge application having been hardened against static and dynamic analysis techniques