A common frustration we’ve encountered is the lack of adequate tooling around ontology and knowledge graph schema design. Many tools exist– some are overly complex, some are very expensive, and none allow one to work visually, collaboratively and in real time on a document with multiple concurrent users. That is why we took half a dozen Capsenta engineers and spent over two years to design and develop a solution.

The result is Gra.fo, a visual, collaborative, and real-time ontology and knowledge graph schema editor. For more info check out the launch blog post.

Industry graph database implement query languages are not composable: graphs in and NOT graphs out. Without a composable query language, graph databases lack key features such as subqueries and views. Imagine if we could design a graph query language from scratch. Furthermore imagine we could create a group of really smart people coming from academia and industry, from theory and systems and work together for over 2 years in order to help shape the future of graph query languages.

We argue that existing graph database management systems should consider supporting two key characteristics. First, it should be composable, meaning, that graphs are the input and the output of queries. Second, the graph query language should treat paths as first-class citizens. Our result is G-CORE, a powerful graph that makes these goals, and strikes a careful balance between expressivity and evaluation complexity.

More info: http://g-core.org/

Selected Publications

• Renzo Angles, Marcelo Arenas, Pablo Barceló, Peter A. Boncz, George H. L. Fletcher, Claudio Gutierrez, Tobias Lindaaker, Marcus Paradies, Stefan Plantikow, Juan F. Sequeda, Oskar van Rest, Hannes Voigt. G-CORE: A Core for Future Graph Query Languages. SIGMOD Conference 2018: 1421-1432

Capsenta is an early-stage enterprise software startup, founded by my PhD advisor Daniel Miranker and myself. The company spun out from the Department of Computer Science at the University of Texas at Austin in 2015. Capsenta is commercializing Ultrawrap, the technology developed during my PhD research. Ultrawrap virtualizes relational databases as semantic web data sources (RDF, OWL, SPARQL) which has enabled us to develop a semantic data virtualization platform used for data integration. At Capsenta, we are changing the way enterprises models, governs and integrates data.

I am lucky to have the opportunity to work with our customers and identify socio-technical research challenges in enterprise data integration which we will continue to investigate.

More info: https://capsenta.com/

Selected Publications

• Juan F. Sequeda and Daniel P. Miranker. A Pay-As-You-Go Methodology for Ontology-Based Data Access. IEEE Internet Computing 21(2): 92-96 (2017)

The Semantic Web’s promise to achieve web-wide data integration requires the inclusion of legacy relational data as RDF, which, in turn, requires the execution of SPARQL queries on the legacy relational database. In this research, we explore a hypothesis: existing commercial relational databases already subsume the algorithms and optimizations needed to support effective SPARQL execution on existing relationally stored data .

Ultrawrap is a Relational Database to RDF (RDB2RDF) system, which encodes a logical representation of the database as a graph using SQL views and a simple syntactic translation of SPARQL queries to SQL queries on those views. Thus, in the course executing a SPARQL query, the SQL optimizer both instantiates a mapping of relational data to RDF and optimizes its execution. Other approaches, such as D2RQ, typically implement aspects of query optimization and execution outside the SQL environment.

Ultrawrap has been evaluated with the Barton and Berlin SPARQL Benchmark across the three major relational database management systems. We identify two important optimizations: detection of unsatisfiable conditions and self-join elimination, such that, when applied, SPARQL queries execute at nearly the same speed as semantically equivalent native SQL queries.

Ultrawrap is currently being commercialized by Capsenta. Please contact ultrawrap@capsenta.com for inquiries.

More info: https://capsenta.com/

Selected Publications

• Juan F. Sequeda, Marcelo Arenas, Daniel P. Miranker. OBDA: Query Rewriting or Materialization? In Practice, Both! ISWC 2014
• Juan F. Sequeda, Daniel P. Miranker. Ultrawrap: SPARQL execution on relational data. J. Web Sem. 22: 19-39 (2013)
• Juan F. Sequeda, Marcelo Arenas, Daniel P. Miranker. On directly mapping relational databases to RDF and OWL. WWW 2012

Constitutional design and redesign is constant. Over the last 200 years, countries have replaced their constitutions an average of every 19 years and some have amended them almost yearly. A basic problem in the drafting of these documents is the search and analysis of model text deployed in other jurisdictions. Traditionally, this process has been ad hoc and the results suboptimal. As a result, drafters generally lack systematic information about the institutional options and choices available to them. In order to address this informational need, we have developed a web application, Constitute, with the use of semantic technologies. Constitute provides searchable access to the world’s constitutions using the conceptualization, texts, and data developed by the Comparative Constitutions Project. An OWL ontology represents 330 “topics” –e.g. right to health– with which we have tagged relevant provisions of nearly all constitutions in force. The tagged texts were then converted to an RDF representation using R2RML mappings and Capsenta’s Ultrawrap. The portal implements semantic search features to allow constitutional drafters to read, search, and compare the world’s constitutions. The goal of the project is to improve the efficiency and systemization of constitutional design and, thus, to support the independence and self-reliance of constitutional drafters.

More info: https://www.constituteproject.org/

Selected Publications

• Zachary Elkins, Tom Ginsburg, James Melton, Robert Shaffer, Juan F. Sequeda, Daniel P. Miranker. Constitute: The world's constitutions to read, search, and compare. J. Web Sem. 27: 10-18 (2014)