Environmental Engineering Reference
In-Depth Information
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A format was defined for interaction and communication between agents
that employed a semistructured message format for defining a language
protocol for the agents.
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A strategy was formulated for distributing controls among agents. The
control strategy initiated by either the coordinator agent or the regular
specialist agent was driven by the requirements of the request or the task
at hand. In certain situations, control was distributed among the agents,
and in other situations, the coordinator agent assigned all tasks to a group
of specialist agents in the form of a semicentralized control framework.
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A policy for coordinating the activities of agents was employed. Our design
allowed the SSA to maintain a directory of the skills of all the agents
and dispense information on the location of other agents upon request. In
addition, SSA monitored the status of each agent and would reactivate,
clone, or migrate them when necessary.
4.1.3 The Human Computer Interface in AFLOAT
A major component of AFLOAT was the User Interface Agent (UIA). The
UIA was ultimately responsible for supporting dialogs and interactions with
outside users of the agent system. In reality, the UIA was a community of
agents, each with specific tasks. The UIA had a user agent that supported
multimodal interaction techniques. As an example, the user could communi-
cate with AFLOAT via typed text or spoken language. There was a Request
Analysis Agent that checked for ambiguities in the user's request, checked
spelling, filtered superfluous words, and performed pattern recognition and
context-dependent analysis. A major component of the UIA was the User
Modeling Agent. This agent was responsible for developing user profiles, clas-
sifying users, dynamically adapting to user behaviors and preferences, and
resolving ambiguities. The Results Management Agent was responsible for in-
teraction with the community of domain specialist agents, collection of results
of work done by the domain specialist agents, integration of results, and noti-
fication of users. The UIA also supported a local request server that provided
the UIA user-environment management, common services such as e-mail and
printing, and results-display support.
AFLOAT also provided an operational domain-restricted natural language
interface. The domain restriction is a requirement both for keeping the prob-
lem tractable and for performance reasons. This interface allowed users simply
to make requests in sentence form. For the grammar component of the natural
language interface, a “semantic” grammar was used. This can be defined as a
grammar in which the syntax and semantics are collapsed into a single uni-
form framework [
5
]. This grammar looks like a context-free grammar except
that it uses semantic categories for terminal symbols. There are several ben-
efits of using a semantic grammar, the main one being that there is no need
for separate processing of semantics. Semantic processing is done in parallel
with syntactic processing. This also means that this method is very ecient,
