Managing Constraints and Preferences: Constrained Tradeoffs-Enhanced Conditional Preference Networks (CTCP-NETS)

In this thesis, a new framework for constraint and preference representation and reasoning is proposed, including the related definitions, algorithms and implementations. A Conditional Preference Network (CP-Net) is a widely used graph model to present the preferences among various outcomes. It allows users to describe their preferences of values over different variables. However, a CP-Net does not express the relations between variables, thus making the orders of outcomes incomplete. Because of this limitation, an extension of the CP-Net called Tradeoffs-enhanced Conditional Preference Network (TCP-Net) has been proposed to express the relative importance between variables. Nonetheless, TCP-Nets have the following drawbacks. 1. Currently there is no research work reporting on the implementation of TCPNets as a solver. In other words, there is no study on the applicability of TCP-Nets in real world applications. 2. TCP-Nets only deal with preferences (soft constraints). Hard constraints are not considered. This is a real limitation when dealing with a wide variety of real life problems. Due to the above limitations, we propose a new model integrating TCP-Nets with the well known Constraint Satisfaction Problem (CSP) framework for constraint processing. The new model is called Constrained TCP-Net (CTCP-Net). This model has been implemented as a three-layer architecture system using Java and provides a GUI for users to freely describe their problem as a set of constraints and preferences. The system will then solve the problem and return the solutions in a reasonable time. Moreover, depending on the problem description, our system offers the capability to represent the given application using CP-Nets, TCP-Nets, Constrained CP-Nets or Constrained TCP-Nets. This allows the users to deal with many real world problems including scheduling and planning, online shopping, auctions and many others. Finally, this thesis provides information for other researchers who are interested in CSPs and graphical models for preferences from the theoretical and practical aspects.

Name thesis:degree_name

Master of Science (MSc)

Level thesis:degree_level

Master's

Discipline thesis:degree_discipline

Computer Science

Grantor dc:publisher

Faculty of Graduate Studies and Research, University of Regina

Year dc:date.issued

2014

Author dc:creator

• Zhang, Shu

Advisors dc:contributor.advisor

• Mouhoub, Malek
• Sadaoui-Mouhoub, Samira

Committee member dc:contributor.committeemember

• Fan, Lisa L.

Language dc:language.iso

en

DOI

https://doi.org/10.82465/3742

OAI identifier oai:identifier

oai:uregina.scholaris.ca:10294/5842