Browsing by Author "Michael Young, Committee Member"

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Affective Behavior Control for Lifelike Pedagogical Agents
(2002-08-21) Stelling, Gary Dean; James C. Lester, Committee Chair; Patrick FitzGerald, Committee Member; Michael Young, Committee Member
Lifelike pedagogical agents should be especially effective in constructivist learning environments in which students participate in active problem solving. We can simulate such a constructivist setting with personal computing using a well-designed, evocative graphical interface and the rich multimedia -- audio, video and animation -- currently available. Beyond such an authentic problem-solving context, constructivist learning employs a social aspect, centered on the interaction of learner and mentor. We submit that an animated pedagogical agent who delivers contextualized problem-solving advice can play the part of the expert. Further, we propose that an added measure of believability and motivation would result from giving these agents the ability to express situationally appropriate emotions. To test the promise of such an affective agent, we first identified the cognitive emotion types most useful in a problem-solving dialog. We then devised a structure to store the details of the learner's situation in order to determine the appropriate emotion from the pedagogical agent. These enhancements have been instantiated in a full-scale implementation of the lifelike pedagogical agent of DESIGN-A-PLANT, a learning environment developed in the domain of botanical anatomy and physiology for middle-school students. Evaluation by a focus group of students was encouraging. They preferred the emotional version of the agent and reported that his affective behavior was helpful in their problem solving.
Control and Protection for Distribution Networks with Distributed Generators
(2004-09-15) El-Markabi, Ismail Mohamed Shaker; Michael Young, Committee Member; Mo-Yuen Chow, Committee Member; Mesut Baran, Committee Chair; Joel Trussell, Committee Member
The connection of distributed generators to distribution networks greatly influences the performance and stability of such networks. The purpose of the dissertation has been to investigate and attempt to resolve the impacts of connecting distributed generators to distribution networks. Two main problems were defined and studied, which are the effect of distributed generators on the feeder voltage regulation and on the feeder protection schemes. A central supervisory controller designed to regulate the feeder's voltage is presented, and the architecture of the controller is shown along with test results illustrating the ability of the controller to regulate the voltage along a feeder with distributed generators with minimum cost. In an attempt to regulate the feeder's voltage without the need for the feeder's explicit model, a multi-agent based distributed controller is proposed. The multi-agent system structure and design are illustrated, and test results comparing the performance of the two proposed controllers are shown. The dissertation then presents an approach to extend conventional fault analysis studies to include inverter interfaced distributed generators. Such an approach is essential for the proper selection and coordination of protective devices for a feeder with distributed generators. Finally, the dissertation illustrates the extent of deterioration a DG can cause on the overcurrent protective relay performance. An approach to solve this problem and restore the overcurrent relay performance is presented.
A Framework for Real-time Synchronization in Intelligent Media Generators
(2004-04-02) Lee, Seung Yong; James Lester, Committee Chair; Michael Young, Committee Member; Patrick FitzGerald, Committee Member
Recent advances in computer graphics and multimedia technologies have contributed to the development of interactive media-rich systems that generate media elements dynamically in multiple modalities to present information in an effective and appealing manner to users. Utilizing media elements in an application that requires them to be temporally coordinated in real-time presents synchronization issues because the wrong timing or duration of media elements will be easily detected by the user. Most media-rich systems have solved various aspects of the media element synchronization problem. However, they have done so in an ad hoc manner without providing a generic reusable framework. This thesis proposes a framework for real-time synchronization in intelligent media generators. Our research addresses six primary issues that are essential to creating media-rich systems that do not utilize an ad hoc solution to their media element synchronization problems: synchronization of media elements, decoupling high-level and low-level processing, extensibility, media element sequencing, real-time performance, and domain-independence. The framework has been implemented in an agent-based multimedia generator for an intelligent tutoring system to demonstrate its feasibility.
Planning with Tradable Reservations in Mobile Assistants operating in Resource Constrained Environments
(2004-03-18) Muguda, Naveenkumar Vishwanath; Munindar Singh, Committee Member; Peter Wurman, Committee Chair; Michael Young, Committee Member
Mobile devices are hand held devices used to deliver time sensitive and locale specific information to the users. In multi-user environments with limited resources, agents running on mobile devices as assistants to their users improve the social welfare in the presence of tradable reservations. The purpose of this research is to show the benefits of planning in such an environment. By conducting various experiments we study the effects, when complex plans are generated to satisfy the user specified constraints and environment enforced constraints. We observe that with tradable reservations the social welfare increases with increase in planning horizon. We also observe that tradable reservations and clairvoyance help the users satisfy their preferences and constraints imposed by environment without loss in social welfare.