7 research outputs found

    Cell Pattern Generation in Artificial Development

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    Zero-maintenance of electronic systems: Perspectives, challenges, and opportunities

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    Self-engineering systems that are capable of repairing themselves in-situ without the need for human decision (or intervention) could be used to achieve zero-maintenance. This philosophy is synonymous to the way in which the human body heals and repairs itself up to a point. This article synthesises issues related to an emerging area of self-healing technologies that links software and hardware mitigations strategies. Efforts are concentrated on built-in detection, masking and active mitigation that comprises self-recovery or self-repair capability, and has a focus on system resilience and recovering from fault events. Design techniques are critically reviewed to clarify the role of fault coverage, resource allocation and fault awareness, set in the context of existing and emerging printable/nanoscale manufacturing processes. The qualitative analysis presents new opportunities to form a view on the research required for a successful integration of zero-maintenance. Finally, the potential cost benefits and future trends are enumerated

    An artificial development model for cell pattern generation

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    La formation de structures cellulaires a un rôle crucial dans le développement tant artificiel que naturel. Cette thèse présente un modèle de développement artificiel pour la génération de structures cellulaires basé sur le paradigme des automates cellulaires (AC). La croissance cellulaire est contrôlée par un génome comportant un réseau de régulation artificiel (RRA) et une série de gènes structurels. Ce génome a subi une évolution par algorithme génétique (AG) afin de produire des structures cellulaires en 2D grâce à l'activation et inhibition sélective des gènes. De plus des gradients morphogénétiques ont été utilisés pour fournir aux cellules une information de position permettant de contraindre leur reproduction. Après évolution d'un génome par algorithme génétique, une cellule unique est placée au milieu de la grille de l’AC où sa reproduction, contrôlée par le RRA, produit une structure cellulaire cible. Le modèle a été appliqué avec succès au problème classique de génération de la structure d’un drapeau français (French flag problem).Cell pattern formation has a crucial role in both artificial and natural development. This thesis presents an artificial development model for cell pattern generation based on the cellular automata (CA) paradigm. Cellular growth is controlled by a genome consisting of an artificial regulatory network (ARN) and a series of structural genes. The genome was evolved by a genetic algorithm (GA) in order to produce 2D cell patterns through the selective activation and inhibition of genes. Morphogenetic gradients were used to provide cells with positional information that constrained cellular replication. After a genome was evolved, a single cell in the middle of the CA lattice was allowed to reproduce controlled by the ARN until a cell pattern was formed. The model was applied to the canonical problem of growing a French flag pattern.

    Managing the Evolution of Dependability Cases for Systems of Systems

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    . Dependability is a composite property consisting of attributes such as reliability, availability, safety and security. The achievement of these attri~utes is often essential for the operational success of systems undertaking critical and complex tasks. .Assurance that the fmal system will demonstrate the required dependability qualities, can be crucial to the acceptance of the system into service. Safety cases are a well established c,oncept used to establish assurance about the safety properties of a system. However, safety cases focus only on one attribute of dependability. The principles and processes ofcreating an integrated dependability case - that assures all aspects of dependable system behaviour - are less well understood. A number of challenges are faced when attempting to support dependability case development. These include the systematic elicitation of dependability goals, the management and justification of trade-offs, and the evolution of multi-attribute arguments in step with the design process. This thesis addresses these challenges by defming a rigorous framework, accompanied by a set of methods, for establishing dependability cases. Firstly, a method for eliciting dependability requirements is defmed by extending existing safety deviational analysis techniques. Secondly, a method for systematically identifying and managing justified trade-offs is presented. Thirdly, the thesis describes the co-evolution of depen~bility . case arguments alongside system development - using a dependability case architecture that corresponds to system structures. Finally, the thesis unifies these contributions by defming a metamodel that captures and interrelates the 'concepts underlying the proposed methods. Evaluation of the work is presented by means of peer review, pilot studies and industrial examples

    Much to do about nothing: the desertification of public health nursing practice in relationship to water and its impact on health

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    The purposes of this phenomenological hermeneutics study were to gain an understanding of the meaning nine public health nurses (PHNs) in southern Alberta attach to their experience of promoting health related to safe and secure water; and to illuminate their emergent understanding of barriers and opportunities in that regard. Semi-structured interviews were conducted, and data analysis followed van Manen’s approach. Under an overarching theme, Being in the Desert, findings are presented through four themes: Desertification of the Practice Context; Desiccation of the PHN; Adaptation of the PHN; and Reclamation of Practice. Barriers to a role with water are central and embedded within the lived experience of PHNs; opportunities lie in the awareness that emerged through the discourse of the interviews. This discourse with PHNs must continue, so that they can begin to articulate an enhanced role in promoting health related to safe and secure water

    Design of Approaches for Dependability and Initial Prototypes

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    The aim of CONNECT is to achieve universal interoperability between heterogeneous Networked Systems. For this, the non-functional properties required at each side of the connection going to be established must be fulfilled. By the one inclusive term "CONNECTability" we comprehend properties belonging to all four non-functional concerns of interest for CONNECT, namely dependability, performance, security and trust. We model such properties in conformance with a meta-model which establishes the relevant concepts and their relations. Then, building on the conceptual models proposed in the first year in Deliverable D5.1, in this document we present the approaches developed for assuring CONNECTability both at synthesis time and at runtime. The contributions include: the Dependability&Performance analysis Enabler, for which we release a modular architecture supporting stochastic verification and state-based analysis; incremental verification and event-based monitoring for runtime analysis; a model-based approach to interoperable trust management; the Security-by-Contract-with-Trust framework, which guarantees and enforces the expected trust levels and security policies

    Evolving dependability

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