My recent research interests can be categorized to two related
themes: (i) Knowledge representation, reasoning and declarative
problem solving, and (ii) Actions, change and histories: formal
theories and applications.

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KNOWLEDGE REPRESENTATION, REASONING and DECLARATIVE PROBLEM
SOLVING

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Representing knowledge and reasoning with it is fundamental to many
tasks and many disciplines. Knowledge comes in various forms from
common-sense knowledge that guide us not to get wet in the rain to
specific domain knowledge that tell us to buy a ticket before
taking a plane to declarative knowledge about what it means to be
a good parent and so on. One important facet of intelligent
systems is to be able to represent knowledge and reason with it
to behave intelligently. This leads to the fundamental quest of
developing a good (or appropriate) knowledge representation language.

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To many the role of such a language is as fundamental as
`Calculus' is to Engineering and Mathematics.

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I have explored and contributed to the development of many
alternative knowledge representation languages and in recent years
have settled on the language AnsProlog. My book titled `Knowledge
representation, reasoning and declarative problem solving' in
press at Cambridge University Press (comes out in Jan 2003) is a
graduate level text book cum compendium of various results about
this language. I am currently working on further development of
this language and also in using it for various applications. In
particular, I am working on learning AnsProlog rules from large
data sets and extending AnsProlog to incorporate probabilities. In
the application side I am working on applications such as ontology
representation, combinatorial auctions, biological knowledge
representation, and problem solving related to shuttle control and
autonomous agents.

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ACTIONS, CHANGE and HISTORIES: FORMAL THEORIES and APPLICATIONS
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An action normally changes the state of the world. For example,
the action of `short-circuiting' may blow up a fuse; the action of
a `ligand coming in contact with a cell membrane' may change the
state of many elements inside the cell; the action of `buying a
ticket' changes the state of the availability of tickets; etc.
More general actions such as `sensing' or `testing' often change
the state of the knowledge of the agent doing the action with or
without changing the state of the world. Representing actions,
reasoning about their impact on the world and/or the agent's
knowledge about the world is important to formulate notions such
as `planning to achieve something', `controlling a dynamical
system', `diagnosing or finding explanations to observed
behavior', `predicting the outcome of a series of actions and
events', `predicting how the world would evolve', etc. Formulating
these is a first step in solving them.

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My research in this area can be categorized into several parts:
(a) Developing languages for representing actions, the structure
of the world, and the effects of the actions on the world. (b)
Developing languages for expressing goals or directives. (c)
Developing ways to achieve (b) given (a), and developing execution
languages and verifying correctness (using (a)) of execution
programs in these languages for a given (b).

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Among the particular applications that I am currently working on
are (i) the actions involved in shuttle control and (ii) the actions
and environment surrounding signal pathways in cells.

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Chitta Baral 11/7/02