Juan F. Sequeda is the co-founder of Capsenta, a spin-off from his research, and the Senior Director of Capsenta Labs. He holds a PhD in Computer Science from the University of Texas at Austin.
His research interests are on the intersection of Logic and Data and in particular between the Semantic Web and Relational Databases for data integration, ontology based data access and semantic/graph data management.
Juan is the recipient of the NSF Graduate Research Fellowship, received 2nd Place in the 2013 Semantic Web Challenge for his work on ConstituteProject.org, Best Student Research Paper at the 2014 International Semantic Web Conference and the 2015 Best Transfer and Innovation Project awarded by Institute for Applied Informatics.
Juan is the PC chair of the ISWC 2017 In-Use track, is on the Editorial Board of the Journal of Web Semantics, member of multiple program committees (ISWC, ESWC, WWW, AAAI, IJCAI), organizer of the AMW Summer School and co-creator of the Consuming Linked Data Workshop series.
Juan is a member of the Graph Query Languages task force of the Linked Data Benchmark Council (LDBC) and has also been an invited expert member and standards editor at the World Wide Web Consortium (W3C).
Semantic Web, Linked Data, Databases, Data Integration, Ontology Based Data Access, Semantic and Graph Data Management
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 research challenges which we will continue to investigate.
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 firstname.lastname@example.org for inquiries.
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.