24,516 research outputs found
Cross-layer system reliability assessment framework for hardware faults
System reliability estimation during early design phases facilitates informed decisions for the integration of effective protection mechanisms against different classes of hardware faults. When not all system abstraction layers (technology, circuit, microarchitecture, software) are factored in such an estimation model, the delivered reliability reports must be excessively pessimistic and thus lead to unacceptably expensive, over-designed systems. We propose a scalable, cross-layer methodology and supporting suite of tools for accurate but fast estimations of computing systems reliability. The backbone of the methodology is a component-based Bayesian model, which effectively calculates system reliability based on the masking probabilities of individual hardware and software components considering their complex interactions. Our detailed experimental evaluation for different technologies, microarchitectures, and benchmarks demonstrates that the proposed model delivers very accurate reliability estimations (FIT rates) compared to statistically significant but slow fault injection campaigns at the microarchitecture level.Peer ReviewedPostprint (author's final draft
Memory Vulnerability: A Case for Delaying Error Reporting
To face future reliability challenges, it is necessary to quantify the risk
of error in any part of a computing system. To this goal, the Architectural
Vulnerability Factor (AVF) has long been used for chips. However, this metric
is used for offline characterisation, which is inappropriate for memory. We
survey the literature and formalise one of the metrics used, the Memory
Vulnerability Factor, and extend it to take into account false errors. These
are reported errors which would have no impact on the program if they were
ignored. We measure the False Error Aware MVF (FEA) and related metrics
precisely in a cycle-accurate simulator, and compare them with the effects of
injecting faults in a program's data, in native parallel runs. Our findings
show that MVF and FEA are the only two metrics that are safe to use at runtime,
as they both consistently give an upper bound on the probability of incorrect
program outcome. FEA gives a tighter bound than MVF, and is the metric that
correlates best with the incorrect outcome probability of all considered
metrics
Human experience in the natural and built environment : implications for research policy and practice
22nd IAPS conference. Edited book of abstracts. 427 pp. University of Strathclyde, Sheffield and West of Scotland Publication. ISBN: 978-0-94-764988-3
Flora robotica -- An Architectural System Combining Living Natural Plants and Distributed Robots
Key to our project flora robotica is the idea of creating a bio-hybrid system
of tightly coupled natural plants and distributed robots to grow architectural
artifacts and spaces. Our motivation with this ground research project is to
lay a principled foundation towards the design and implementation of living
architectural systems that provide functionalities beyond those of orthodox
building practice, such as self-repair, material accumulation and
self-organization. Plants and robots work together to create a living organism
that is inhabited by human beings. User-defined design objectives help to steer
the directional growth of the plants, but also the system's interactions with
its inhabitants determine locations where growth is prohibited or desired
(e.g., partitions, windows, occupiable space). We report our plant species
selection process and aspects of living architecture. A leitmotif of our
project is the rich concept of braiding: braids are produced by robots from
continuous material and serve as both scaffolds and initial architectural
artifacts before plants take over and grow the desired architecture. We use
light and hormones as attraction stimuli and far-red light as repelling
stimulus to influence the plants. Applied sensors range from simple proximity
sensing to detect the presence of plants to sophisticated sensing technology,
such as electrophysiology and measurements of sap flow. We conclude by
discussing our anticipated final demonstrator that integrates key features of
flora robotica, such as the continuous growth process of architectural
artifacts and self-repair of living architecture.Comment: 16 pages, 12 figure
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