44 research outputs found
A Constructor-Based Reachability Logic for Rewrite Theories
Reachability logic has been applied to K
rewrite-rule-based language definitions as a
language-generic logic of programs. It has been proved
successful in verifying a wide range of sophisticated programs in
conventional languages. Here we study how reachability logic
can be made not just language-generic, but
rewrite-theory-generic to make it available not just
for conventional program verification, but also to verify rewriting-logic-based
programs and distributed system designs. A theory-generic
reachability logic is presented and proved sound for a wide class of
rewrite theories. Particular attention is given to increasing the
logic's automation by means of constructor-based semantic
unification, matching, and satisfiability procedures. The
relationships to Hoare logic and LTL are discussed, new methods for
proving invariants of possibly never terminating distributed systems
are developed, and experiments with a prototype implementation
illustrating the new methods are presented.Partially supported by NSF Grants CNS 13-19109 and CNS 14-09416, and AFOSR Contract FA8750-11-2-0084.Ope
Generalized Rewrite Theories and Coherence Completion
A new notion of generalized rewrite theory
suitable for symbolic reasoning and generalizing the standard notion
is motivated and defined.
Also, new requirements for symbolic executability
of generalized rewrite theories that extend those
for standard rewrite theories, including
a generalized notion of coherence, are given.
Finally, symbolic executability, including coherence,
is both ensured and made available for
a wide class of such theories by
automatable theory transformations.Partially supported by by NRL under contract number N00173-17-1-G002.Ope
Advanced Endoscopic Imaging Techniques for the Study of Colonic Mucosa in Patients with Inflammatory Bowel Disease
Background. Crohn’s disease and ulcerative colitis are inflammatory bowel diseases (IBD) associated with colorectal cancer risk in long-standing diseases. In order to assess the colonic mucosa and to discover dysplastic or neoplastic lesions, advanced endoscopic techniques are needed. Such techniques are detailed in this review: chromoendoscopy, autofluorescence imaging (AFI), narrow band imaging (NBI), i-SCAN, Fujinon Intelligent Color Enhancement (FICE) and confocal laser endomicroscopy (CLE)
Study on the obtaining of cobalt oxides by thermal decomposition of some complex combinations, undispersed and dispersed in SiO2 matrix
Tertiary tectonic evolution of the external Southern Carpathians and the adjacent Moesian platform (Romania)
Contribution of dynamic vegetation phenology to decadal climate predictability
In this study, the impact of coupling and initializing the leaf area index from the dynamic vegetation model Lund-Potsdam-Jena General Ecosystem Simulator (LPJ-GUESS) is analyzed on skill of decadal predictions in the fully coupled atmosphere-land-ocean-sea ice model, the European Consortium Earth System Model (EC-Earth). Similar to the impact of initializing the model with the observed oceanic state, initializing the leaf area index (LAI) fields obtained from an offline LPJ-GUESS simulation forced by the observed atmospheric state leads to a systematic drift.A different treatment of the water and soil moisture budget in LPJ-GUESS is a likely cause of this drift. The coupled system reduces the cold bias of the reference model over land by reducing LAI (and the associated evaporative cooling), particularly outside the growing season. The coupling with the interactive vegetation module implies more degrees of freedom in the coupled model, which generates more noise that can mask a portion of the extra signal that is generated. The forecast reliability improves marginally, particularly early in the forecast. Ranked probability skill scores are also improved slightly in most areas analyzed, but the signal is not fully coherent over the forecast interval because of the relatively low number of ensemble members. Methods to remove the LAI drift and allow coupling of other variables probably need to be implemented before significant forecast skill can be expected