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We present an automatic iterative abstraction-re nement methodology in which the initial abstract model is generated by an automatic analysis of the control structures in the program to be veri ed. Abstract models may admit erroneous (or \spurious") counterexamples. We devise new symbolic techniques which analyze such counterexamples and re ne the abstract(More)
This paper introduces novel techniques for exact and approximate inference in Dynamic Bayesian Networks (DBNs) based on algorithms, data structures, and formalisms from the field of model checking. Model checking comprises a family of techniques from for formally verifying systems of concurrent reactive processes. We discuss: i) the use of temporal logics(More)
We used a hardware description language to construct a formal model of the cache coherence protocol described in the draft IEEE Futurebus+ standard. By applying temporal logic model checking techniques, we found several errors in the standard. The result of our project is a concise, comprehensible and unambiguous model of the protocol that should be useful(More)
Achieving high performance for distributed I/O on a wide-area network continues to be an elusive holy grail. Despite enhancements in network hardware as well as software stacks, achieving high-performance remains a challenge. In this paper, our worldwide team took a completely new and non-traditional approach to distributed I/O, called ParaMEDIC: Parallel(More)
BACKGROUND Short term and medium term survival predictive value of the Child-Turcotte-Pugh (CTP) and Model for End Stage Liver Disease (MELD) score has been established but their usefulness in predicting survival of hospitalized patients with decompensated cirrhosis is lacking. We compared the survival predictive value of these scoring systems in(More)
Derecho is an RDMA-based distributed computing framework that unifies group membership management, consistent data replication and persistence. Applications are structured as top-level groups which can be split into subgroups or automatically sharded in a regular manner. To preserve membership invariants, Derecho adjusts subgroup membership as parent-group(More)
Today’s platforms provide surprisingly little help to developers of high-performance scalable services. To address this, Derecho automates the creation of complex application structures in which each member plays a distinct role. Derecho’s data plane runs a novel RDMAbased multicast protocol that scales exceptionally well. The Derecho control plane(More)
Bounded-rate multi-mode systems are hybrid systems that can switch among a finite set of modes. Its dynamics is specified by a finite number of real-valued variables with mode-dependent rates that can vary within given bounded sets. Given an arbitrary piecewise linear trajectory, we study the problem of following the trajectory with arbitrary precision,(More)
Cloud computing frameworks replicate large objects for diverse reasons, often under time-pressure. RDMC (Reliable DMA Multicast) is a reliable data replication protocol that runs at exceptionally high speeds and low latencies, implementing multicast as a pattern of RDMA unicast operations using a novel approach that maximizes concurrency. Users with(More)
SAGAR JHA, Cornell University, USA JONATHAN BEHRENS, Cornell University, USA and MIT, USA THEO GKOUNTOUVAS, Cornell University, USA MATTHEW MILANO, Cornell University, USA WEIJA SONG, Cornell University, USA EDWARD TREMEL, Cornell University, USA SYDNEY ZINK, Cornell University, USA KENNETH P. BIRMAN, Cornell University, USA ROBBERT VAN RENESSE, Cornell(More)