[Colloquium] Gao/Dissertation Defense/2-13-06

[Margaret Jaffey]

	Department of Computer Science/The University of Chicago

			*** Dissertation Defense ***

Candidate: Han Gao

Date: Monday, February 13, 2006

Time and Location:  10:00 a.m. in Ryerson 276

Title:  Network Services: The Future of Advanced Collaborative  
Environments

Abstract:

The purpose of this research was to design an infrastructure of the
network services which support a seamless integration of collaborative
environments. Since conventional cooperative software require particular
configurations from users, many individuals and groups are hampered from
using these tools due to technical and resource limitations. Therefore,
the expectation of the infrastructure was to lower the barriers to using
the collaborative environments by creating the middleware that  
provides a
set of services for capability negotiation and data stream processing as
an approach of bridging the technology mismatch between required
equipments and limited resources. The study concentrated mainly on the
design of network services and its infrastructure, matchmaking in  
resource
management, performance modeling, monitoring and assessing, and overlay
network topology analysis.

Our research has two basic assumptions: high computational  
performance and
plentiful network provisions; group-oriented collaboration settings. The
thesis first proposes a multiple layered, hierarchical system  
architecture
for the development and the utilization of the network services. It
supports the semantics of the network services and ensures that they run
smoothly under its environment.

Secondly, the thesis defines a mathematical model of capability matching
for three-party agreements: requests from users, resources, and the
network services. Based on the mathematical model, we provide a general
approach for capability matching. The research also presents a new
language schema for capability descriptions.

Because many real-time cooperative works choose multicast networks as
backbone, the dissertation argues two sets of multicast metrics  
according
to the conceptual differences between IP multicast and overlay mesh
multicast. The metrics improve the quality of performance monitoring and
assessment substantially.

A hybrid overlay mesh is an approach to extend collaborative  
applications
via unicast and multicast networks. This research developed a heuristic
algorithm which combines k-best links strategy and clustering for
constructions of the hybrid overlay mesh. The experimental results
proved a positive impact on this study.

The dissertation concludes that management modules support the
infrastructure of the network services effectively. The further  
conclusion
is that based on the accomplished management models, the network  
services
and their infrastructure play a significant role in the development of
advanced collaborative environments.

Candidate's Advisor: Prof. Rick Stevens

A draft copy of Mr. Gao's dissertation will be available shortly in  
Ry 161A.


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Margaret P. Jaffey                             margaret at cs.uchicago.edu
Department of Computer Science
Student Support Rep (Ry 161A)        (773) 702-6011
The University of Chicago                  http://www.cs.uchicago.edu
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