Nuno Machado

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We present Symbiosis: a concurrency debugging technique based on novel <i>differential schedule projections</i> (DSPs). A DSP shows the small set of memory operations and dataflows responsible for a failure, as well as a reordering of those elements that avoids the failure. To build a DSP, Symbiosis first generates a <i>full, failing, multithreaded(More)
Type 2 diabetes (T2D) is considered a major risk factor for Alzheimer's disease (AD). To elucidate the links between both pathological conditions, we compared behavioral and cognitive functions, cerebral amyloid-β peptide (Aβ) levels and vasculature integrity of 11-month-old T2D and AD mice. For this purpose, we performed behavioral tests (open field,(More)
This paper presents CoopREP, a system that provides support for fault replication of concurrent programs, based on cooperative recording and partial log combination. CoopREP employs partial recording to reduce the amount of information that a given program instance is required to store in order to support deterministic replay. This allows to substantially(More)
Deterministic replay tools are a useful asset when it comes to pinpoint hard-to-reproduce bugs. However, no sweet spot has yet been found with respect to the trade-off between recording overhead and bug reproducibility, especially in the context of search-based deterministic replay techniques, which rely on inference mechanisms. In this paper, we argue(More)
This paper presents property-driven partial logging, a novel information partition scheme that takes into account load balancing and shared variable properties to optimize the replay of Java concurrency bugs through partial log combination. Preliminary evaluation with standard benchmarks and a real-world application provides initial evidence of the(More)
Recent models of semantic memory propose that the semantic representation of concepts is based, in part, on a network of features. In this view, a feature that is distinctive for an object (a zebra has stripes) is processed differently from a feature that is shared across many objects (a zebra has four legs). The goal of this paper is to determine whether(More)
The peer-to-peer (P2P) paradigm has emerged as a viable alternative to overcome limitations of the client-server model namely, in terms of scalability, fault-tolerance, and even operational costs. This paradigm has gained significant popularity with its successful application in the context of file sharing applications. The success of these applications is(More)
A distributed system is often built on top of an overlay network. Overlay networks enable network topology transparency while, at the same time, can be designed to provide efficient data dissemination, load balancing, and even fault tolerance. They are constructed by defining logical links between nodes creating a node graph. In practice, this is(More)