94 citations · 328 across the 28 of their papers we have counts for
28 papers
The Linked Data Benchmark Council (LDBC): Driving competition and collaboration in the graph data management space
Gábor Szárnyas, Brad Bebee, Altan Birler +30
Graph data management is instrumental for several use cases such as recommendation, root cause analysis, financial fraud detection, and enterprise knowledge representation. Efficie…
Bridging graph data models: RDF, RDF-star, and property graphs as directed acyclic graphs
Ewout Gelling, George Fletcher, Michael Schmidt
Graph database users today face a choice between two technology stacks: the Resource Description Framework (RDF), on one side, is a data model with built-in semantics that was orig…
PG-Schema: Schemas for Property Graphs
Renzo Angles, Angela Bonifati, Stefania Dumbrava +18
Property graphs have reached a high level of maturity, witnessed by multiple robust graph database systems as well as the ongoing ISO standardization effort aiming at creating a ne…
Reasoning on Property Graphs with Graph Generating Dependencies
Larissa C. Shimomura, Nikolay Yakovets, George Fletcher
Graph Generating Dependencies (GGDs) informally express constraints between two (possibly different) graph patterns which enforce relationships on both graph's data (via property v…
The Banking Transactions Dataset and its Comparative Analysis with Scale-free Networks
Akrati Saxena, Yulong Pei, Jan Veldsink +3
We construct a network of 1.6 million nodes from banking transactions of users of Rabobank. We assign two weights on each edge, which are the aggregate transferred amount and the t…
GenCAT: Generating Attributed Graphs with Controlled Relationships between Classes, Attributes, and Topology
Seiji Maekawa, Yuya Sasaki, George Fletcher +1
Generating large synthetic attributed graphs with node labels is an important task to support various experimental studies for graph analysis methods. Existing graph generators fai…
A General Cardinality Estimation Framework for Subgraph Matching in Property Graphs
Wilco van Leeuwen, George Fletcher, Nikolay Yakovets
Many techniques have been developed for the cardinality estimation problem in data management systems. In this document, we introduce a framework for cardinality estimation of quer…
Threshold Queries in Theory and in the Wild
Angela Bonifati, Stefania Dumbrava, George Fletcher +7
Threshold queries are an important class of queries that only require computing or counting answers up to a specified threshold value. To the best of our knowledge, threshold queri…
[Technical Report] Combining Sampling and Synopses with Worst-Case Optimal Runtime and Quality Guarantees for Graph Pattern Cardinality Estimation
Kyoungmin Kim, Hyeonji Kim, George Fletcher +1
Graph pattern cardinality estimation is the problem of estimating the number of embeddings of a query graph in a data graph. This fundamental problem arises, for example, during qu…
How Fair is Fairness-aware Representative Ranking and Methods for Fair Ranking
Akrati Saxena, George Fletcher, Mykola Pechenizkiy
Rankings of people and items has been highly used in selection-making, match-making, and recommendation algorithms that have been deployed on ranging of platforms from employment w…
NodeSim: Node Similarity based Network Embedding for Diverse Link Prediction
Akrati Saxena, George Fletcher, Mykola Pechenizkiy
In real-world complex networks, understanding the dynamics of their evolution has been of great interest to the scientific community. Predicting future links is an essential task o…
Knowledge Scientists: Unlocking the data-driven organization
George Fletcher, Paul Groth, Juan Sequeda
Organizations across all sectors are increasingly undergoing deep transformation and restructuring towards data-driven operations. The central role of data highlights the need for…
GGDs: Graph Generating Dependencies
Larissa C. Shimomura, George Fletcher, Nikolay Yakovets
We propose Graph Generating Dependencies (GGDs), a new class of dependencies for property graphs. Extending the expressivity of state of the art constraint languages, GGDs can expr…
Language-aware Indexing for Conjunctive Path Queries
Yuya Sasaki, George Fletcher, Makoto Onizuka
Conjunctive path queries (CPQ) are one of the most frequently used queries for complex graph analysis. However, current graph indexes are not tailored to fully support the power of…
Novelty Producing Synaptic Plasticity
Anil Yaman, Giovanni Iacca, Decebal Constantin Mocanu +2
A learning process with the plasticity property often requires reinforcement signals to guide the process. However, in some tasks (e.g. maze-navigation), it is very difficult (or i…
Learning with Delayed Synaptic Plasticity
Anil Yaman, Giovanni Iacca, Decebal Constantin Mocanu +2
The plasticity property of biological neural networks allows them to perform learning and optimize their behavior by changing their configuration. Inspired by biology, plasticity c…
Evolving Plasticity for Autonomous Learning under Changing Environmental Conditions
Anil Yaman, Giovanni Iacca, Decebal Constantin Mocanu +3
A fundamental aspect of learning in biological neural networks is the plasticity property which allows them to modify their configurations during their lifetime. Hebbian learning i…
Limited Evaluation Cooperative Co-evolutionary Differential Evolution for Large-scale Neuroevolution
Anil Yaman, Decebal Constantin Mocanu, Giovanni Iacca +2
Many real-world control and classification tasks involve a large number of features. When artificial neural networks (ANNs) are used for modeling these tasks, the network architect…
struc2gauss: Structural Role Preserving Network Embedding via Gaussian Embedding
Yulong Pei, Xin Du, Jianpeng Zhang +2
Network embedding (NE) is playing a principal role in network mining, due to its ability to map nodes into efficient low-dimensional embedding vectors. However, two major limitatio…
Comparing Downward Fragments of the Relational Calculus with Transitive Closure on Trees
Jelle Hellings, Marc Gyssens, Yuqing Wu +4
Motivated by the continuing interest in the tree data model, we study the expressive power of downward navigational query languages on trees and chains. Basic navigational queries…
G-CORE: A Core for Future Graph Query Languages
Renzo Angles, Marcelo Arenas, Pablo Barceló +9
We report on a community effort between industry and academia to shape the future of graph query languages. We argue that existing graph database management systems should consider…
gMark: Schema-Driven Generation of Graphs and Queries
Guillaume Bagan, Angela Bonifati, Radu Ciucanu +3
Massive graph data sets are pervasive in contemporary application domains. Hence, graph database systems are becoming increasingly important. In the experimental study of these sys…
Structural characterizations of the navigational expressiveness of relation algebras on a tree
George H. L. Fletcher, Marc Gyssens, Jan Paredaens +2
Given a document D in the form of an unordered node-labeled tree, we study the expressiveness on D of various basic fragments of XPath, the core navigational language on XML docume…
Relative Expressive Power of Navigational Querying on Graphs
George H. L. Fletcher, Marc Gyssens, Dirk Leinders +5
Motivated by both established and new applications, we study navigational query languages for graphs (binary relations). The simplest language has only the two operators union and…