I have worked largely on two projects.
  1. Transparent Accountable Datamining Initiative, in joint collaboration with Decentralized Information Group, CSAIL, MIT. We worked on the following:
    1. Formalizing the AIR language, developed for describing and reasoning about accountability policies, e.g., for data usage. We defined a declarative semantics for the AIR language.
    2. Designing a new justification ontology to present the policy decisions, that is proofs for the decisions reached by the AIR reasoner.
    3. Defining a mapping from AIR to RIF-PRD, so that AIR rules can be exchanged using the semantic web standard interchange format, RIF.

  2. Ontology for Quantitative Descriptions of Natural, Physical Processes, internally funded by Tetherless World Constellation. Our method of attack:
    1. Identify a suitable logic formalism for quantitative descriptions of continuous processes/changes. We picked Event Calculus formalism.
    2. Analyze the formalism for improvements from knowledge representation perspective. We figured that descriptions of additive effects needed improvement. We used First-order Logic with aggregates, with a novel nonmonotonic reasoning strategy, to enable support for general and concise descriptions of additive effects in Event Calculus.
    3. Build a logic-cum-numerical reasoner, that combines logical reasoning with solving of ordinary differential equations, as none exists for any formalism. We are implementing a model builder for Event Calculus theories using answer-set solvers (DLV and DLVHEX) and Mathematica.
    4. Design an ontology (or an ontology language) for descriptions of continuous changes on semantic web, to complement the ontology languages (such as OWL) and ontologies for semantic web data. We defined a Web Ontology Language for descriptions of Continuous Changes, WOLCC.