180 research outputs found

    Dependable Embedded Systems

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    This Open Access book introduces readers to many new techniques for enhancing and optimizing reliability in embedded systems, which have emerged particularly within the last five years. This book introduces the most prominent reliability concerns from today’s points of view and roughly recapitulates the progress in the community so far. Unlike other books that focus on a single abstraction level such circuit level or system level alone, the focus of this book is to deal with the different reliability challenges across different levels starting from the physical level all the way to the system level (cross-layer approaches). The book aims at demonstrating how new hardware/software co-design solution can be proposed to ef-fectively mitigate reliability degradation such as transistor aging, processor variation, temperature effects, soft errors, etc. Provides readers with latest insights into novel, cross-layer methods and models with respect to dependability of embedded systems; Describes cross-layer approaches that can leverage reliability through techniques that are pro-actively designed with respect to techniques at other layers; Explains run-time adaptation and concepts/means of self-organization, in order to achieve error resiliency in complex, future many core systems

    NGF Abstracts and Proceedings

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    Abstracts of manuscripts submitted in 1990 for publication

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    This volume contans the abstracts of manuscripts submitted for publication during calendar year 1990 by the staff and students of the Woods Hole Oceanographic Institution. We identify the journal of those manuscripts which are in press or have been published. The volume is intended to be informative, but not a bibliography. The abstracts are listed by title in the Table of Contents and are grouped into one of our five deparments, Marine Policy Center, Coastal Research Center, or the student category. An author index is presented in the back to facilitate locating specific papers

    Mass-wasting episodes in the geological evolution of the Azores islands : timing, recurrence, mechanisms and consequence

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    Tese de doutoramento (co-tutela), Geologia (Geodinâmica Interna), Faculdade de Ciências da Universidade de Lisboa, Faculté des Sciences D’Orsay-Université Paris-Sud, 2014Large-scale flank collapses are recurrent in the geological evolution of volcanic ocean islands. Such catastrophic episodes of destabilization can be voluminous and generate large tsunamis, which may cause considerable damage and thus represent extremely hazardous events. The Azores islands east of the Mid-Atlantic Ridge are located on the Eurasia(Eu)/Nubia(Nu) plate boundary, and therefore subject to structural control and seismic activity (historical events of magnitude up to ca. 7). However, prior to MEGAHazards Project (PTDC/CTE-GIX/108149/2008, funded by FCT, Portugal), large-scale flank collapses in the Azores were considered to be lacking, mainly due to the small dimension of the volcanic edifices. Here, we conclude unequivocally on the occurrence of such events in the Azores. The present PhD thesis addresses the evolution of the Pico-Faial steep volcanic ridge, which sits on a major normal fault associated with the Eu/Nu diffuse boundary, focusing especially on the large-scale flank failures in Pico Island. Based on high-resolution sub-aerial and submarine Digital Elevation Models, new structural and stratigraphic data, and highresolution K-Ar dating on separated volcanic groundmass, we: (1) constrain the volcano stratigraphy of Pico; (2) reconstruct the major phases of growth and destruction in Pico and Faial islands in the last 200 kyr; (3) reconstruct the ca. 125 kyr evolution of the currently active large-scale slump in the SE of Pico Island; (4) provide new structural data/interpretations regarding the scarp that sharply cuts the S flank of Pico Stratovolcano; (5) report on the occurrence of large-scale failures in the N and S flanks of the Pico Island between ca. 125 and 70 ka, which generated large submarine debris deposits; and (6) propose that the role of the Pico-Faial ridge as a structure accommodating part of the extension on the diffuse Nu/Eu boundary has been consolidated in the last ca. 125 kyr. Many factors favouring the development of such large-scale flank instabilities have been proposed in the literature, but their exact role and mutual contribution remain poorly understood. We here present an analytical solution for the cohesive Coulomb Critical Wedge theory applied to gravitational instabilities, and associated analogue simulations to test some structural implications of the model. We investigate the impact of several variables on the stability of volcanic flanks, including: wedge slope and dimensions, cohesion, internal friction along the basal detachment, and fluid overpressure. We conclude that: (1) the steepening of the volcanic flanks and basal detachment lead to a decrease in the fluid overpressure ratio (fluid overpressure divided by lithostatic pressure) necessary to produce failure. (2) The decrease of the stabilizing effect of cohesion with increasing depth of the basal detachment favours the occurrence of deep-seated large-scale gravitational destabilization in basal detachments deeper than ca. 2000-2500 m (in volcanic edifices necessarily higher than 2500 m). For shallower basal detachments, the overpressure ratios required to induce failure are comparatively larger. For shallower basal detachments, steeper flanks and stronger edifice materials, shallow failure parallel to the edifice flank surface is favoured, instead of deep-seated deformation. (3) With increasingly deeper basal detachments (possible in larger volcanic edifices), while the impact of cohesion diminishes, the relative importance of basal internal friction for the stability of the edifice increases. The investigation of the occurrence of large-scale mass-wasting in the Azores islands, and the modelling of the variables controlling the stability of the volcanic edifices are only at their first steps and will be further developed in the future.Fundação para a Ciência e a Tecnologia (FCT

    Geotechnical Engineering for the Preservation of Monuments and Historic Sites III

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    The conservation of monuments and historic sites is one of the most challenging problems facing modern civilization. It involves, in inextricable patterns, factors belonging to different fields (cultural, humanistic, social, technical, economical, administrative) and the requirements of safety and use appear to be (or often are) in conflict with the respect of the integrity of the monuments. The complexity of the topic is such that a shared framework of reference is still lacking among art historians, architects, structural and geotechnical engineers. The complexity of the subject is such that a shared frame of reference is still lacking among art historians, architects, architectural and geotechnical engineers. And while there are exemplary cases of an integral approach to each building element with its static and architectural function, as a material witness to the culture and construction techniques of the original historical period, there are still examples of uncritical reliance on modern technology leading to the substitution from earlier structures to new ones, preserving only the iconic look of the original monument. Geotechnical Engineering for the Preservation of Monuments and Historic Sites III collects the contributions to the eponymous 3rd International ISSMGE TC301 Symposium (Naples, Italy, 22-24 June 2022). The papers cover a wide range of topics, which include:   - Principles of conservation, maintenance strategies, case histories - The knowledge: investigations and monitoring - Seismic risk, site effects, soil structure interaction - Effects of urban development and tunnelling on built heritage - Preservation of diffuse heritage: soil instability, subsidence, environmental damages The present volume aims at geotechnical engineers and academics involved in the preservation of monuments and historic sites worldwide

    Genetic analysis of a candidate region for psychiatric illness on chromosone 4p

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    Psychiatric illnesses are debilitating conditions for those affected and place a significant burden on the National Health Service, the social services and the family. Here I describe genetic analysis, physical mapping and transcript mapping of a region of chromosome 4p that is linked to psychiatric illness, including bipolar and unipolar affective disorders and schizophrenia.I have studied four families that show linkage of psychiatric illness to chromosome 4p. Linkage was first observed in a large family, F22, segregating bipolar affective disorder (BPAD) and recurrent major depression (RMD). Subsequently, a smaller family, F59, segregating affective disorders (Blackwood et al, 1996a), and two families (F50 & F48) segregating schizophrenia (SCZ), schizoaffective disorder and BPAD confirmed this linkage.Previously, comparison of the haplotypes inherited with illness in each family allowed prioritisation of two sub-regions for detailed study. Minimal Region One (MR1) is defined by overlap of the disease chromosomes from three Celtic families (F22, F59 & F50). Minimal Region Two (MR2) is defined by the two largest families F22 and F48, as well as F50. The sequence available from the human genome sequencing project for these two regions is largely complete. Here, I describe an extension to the BAC map in the repetitive telomeric end of MR1. The telomeric end of MR1 is defined by a recombination event in an individual from F50. I mapped clones, designed markers and refined the position of the recombination breakpoint. I also refined the position of the recombination breakpoint at the centromeric end of MR1, as defined by a member of F59.I describe construction of a transcript map of MR land 2 using bioinformatics methods, RT-PCR and cDNA library screening. I then selected two candidate genes from this region: orphan g-protein-coupled receptor 78 (GPR78) and superoxide dismutase 3 (SOD3), for further study. Firstly, I identified SNPs in the genes from the linked families, and then carried out a preliminary association study on 95 SCZ in patients, 93 BPAD patients 95 controls. The linkage disequilibrium (LD) between the markers was measured and, using a low stringency significant p-value cut off, revealed a positive association in GPR78. SNPs were then tested on a larger population for association. This work adds to the case for studying the role of chromosome 4 in the genetic susceptibility to affective disorder

    Tracing back the source of contamination

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    From the time a contaminant is detected in an observation well, the question of where and when the contaminant was introduced in the aquifer needs an answer. Many techniques have been proposed to answer this question, but virtually all of them assume that the aquifer and its dynamics are perfectly known. This work discusses a new approach for the simultaneous identification of the contaminant source location and the spatial variability of hydraulic conductivity in an aquifer which has been validated on synthetic and laboratory experiments and which is in the process of being validated on a real aquifer
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