Results 41 to 50 of about 4,278 (200)

Eliminating Recursion from Monadic Datalog Programs on Trees

, 2015
We study the problem of eliminating recursion from monadic datalog programs on trees with an infinite set of labels. We show that the boundedness problem, i.e., determining whether a datalog program is equivalent to some nonrecursive one is undecidable ...
D Calvanese, Filip Mazowiecki, G Hillebrand, H Gaifman, Henrik Björklund, J Naughton, J Naughton, Michael Benedikt, Mikołaj Bojańczyk, O Shmueli, S Abiteboul, S Ceri, Y Sagiv   +12 more
core   +1 more source

Imaging of Biphoton States: Fundamentals and Applications

Advanced Functional Materials, EarlyView.
Quantum states of two photons exhibit a rich polarization and spatial structure, which provides a fundamental resource of strongly correlated and entangled states. This review analyzes the physics of these intriguing properties and explores the various techniques and technologies available to measure them, including the state of the art of their ...
Alessio D'Errico, Ebrahim Karimi
wiley   +1 more source

2D Magnetic and Topological Quantum Materials and Devices for Ultralow Power Spintronics

Advanced Functional Materials, EarlyView.
2D magnets and topological quantum materials enable ultralow‐power spintronics by combining robust magnetic order with symmetry‐protected, Berry‐curvature‐driven transport. Fundamentals of 2D anisotropy and spin‐orbit‐coupling induced band inversion are linked to scalable growth and vdW stacking.
Brahmdutta Dixit, Yifei Yang, Shawn Li, Yu‐Chia Chen, Qi Jia, Jian‐Ping Wang   +5 more
wiley   +1 more source

Challenges for Efficient Query Evaluation on Structured Probabilistic Data

, 2016
Query answering over probabilistic data is an important task but is generally intractable. However, a new approach for this problem has recently been proposed, based on structural decompositions of input databases, following, e.g., tree decompositions ...
A Amarilli, A Darwiche, B Courcelle, D Berwanger, E Grädel, G Gottlob, H Andréka, HL Bodlaender, HL Bodlaender, N Dalvi, S Arnborg, SL Lauritzen   +11 more
core   +3 more sources

From Clinic to Computation: Multiscale Bioengineering Strategies for Durable Biological Aortic Valve Replacements

Advanced Functional Materials, EarlyView.
Bioprosthetic aortic valves have revolutionized the treatment of aortic stenosis, but their durability is limited by structural valve deterioration (SVD). This review focuses on the pericardial tissue at the heart of these valves, examining how its mechanical properties and calcification drive fatigue and failure.
Gabriele Greco, Pierfrancesco Gaziano, Serena Anglese, Simone Morganti, Carlo de Vincentiis, Ferdinando Auricchio, Michele Marino, Michele Conti   +7 more
wiley   +1 more source

View Selection in Semantic Web Databases [PDF]

, 2011
We consider the setting of a Semantic Web database, containing both explicit data encoded in RDF triples, and implicit data, implied by the RDF semantics. Based on a query workload, we address the problem of selecting a set of views to be materialized in
François Goasdoué, François Goasdoué, Ioana Manolescu, Julien Leblay, Julien Leblay, Konstantinos Karanasos, Konstantinos Karanasos, Équipes-projets Leo   +7 more
core   +10 more sources

Boundedness for Unions of Conjunctive Regular Path Queries over Simple Regular Expressions

Proceedings of the TwentyFirst International Conference on Principles of Knowledge Representation and Reasoning
The problem of whether a recursive query can be rewritten as query without recursion is a fundamental reasoning task, known as the boundedness problem. Here we study the boundedness problem for Unions of Conjunctive Regular Path Queries (UCRPQs), a navigational query language extensively used in ontology and graph database querying.
Figueira, Diego, Krishna, S., Mishra, Om Swostik, Padmanabha, Anantha   +3 more
openaire   +2 more sources

Elucidating the Role of Surface Ligands on the Oxidative Etching of Au Bipyramids During Photothermia Using Liquid Cell Transmission Electron Microscopy

Advanced Functional Materials, EarlyView.
Gold bipyramids can act as efficient plasmonic nanoheaters, but they often reshape during laser heating. This study shows that oxygen nanobubbles drive oxidative etching and that surface ligands control stability. CTAB‐ and citrate‐coated particles blunt and lose optical performance, whereas polystyrene sulfonate preserves shape and heating by ...
Irene López‐Sicilia, Valentina Girelli Consolaro, Sophie Marbach, Nancy Rahbany, Grégoire Petit, Ovidiu Ersen, Juan J. Giner‐Casares, Ali Abou‐Hassan   +7 more
wiley   +1 more source

Acyclic Conjunctive Regular Path Queries are no Harder than Corresponding Conjunctive Queries

We present an output-sensitive algorithm for evaluating an acyclic Conjunctive Regular Path Query (CRPQ). Its complexity is written in terms of the input size, the output size, and a well-known parameter of the query that is called the "free-connex fractional hypertree width". Our algorithm improves upon the complexity of the recently introduced output-
Khamis, Mahmoud Abo, Hurjui, Alexandru-Mihai, Kara, Ahmet, Olteanu, Dan, Suciu, Dan   +4 more
openaire   +2 more sources

Approximation and Semantic Tree-Width of Conjunctive Regular Path Queries

, 2023
We show that the problem of whether a query is equivalent to a query of tree-width k is decidable, for the class of Unions of Conjunctive Regular Path Queries with two-way navigation (UC2RPQs). A previous result by Barceló, Romero, and Vardi [Pablo Barceló et al., 2016] has shown decidability for the case k = 1, and here we show that decidability in ...
Figueira, Diego, Morvan, Rémi
openaire   +2 more sources