You can choose topics from the below, but not limited to:

Mathematics

Analysis
Algebra
Algorithm
Applied Mathematics
Computational Mathematics
Control Theory and Automation
Data Mining and Soft Computing
Geometry
Mathematical Chemistry and Biology
Optimization and Operational Research
Rough Set and Soft Set Theory
Statistics
Theoretical Computer Science

Optimization Methods

Linear and Nonlinear Optimization
Global Optimization
Semi-definite Optimization
Semi-infinite Optimization
Multi-objective Optimization
Stochastic Optimization
Derivative-free Optimization
Network Optimization
Scheduling Problems
Optimal Control
Inverse Problems
Automatic Differentiation
Optimization Software

Computing Methods and Advanced Computing

Pervasive Computing
Green Computing
Grid Computing
Soft Computing
Cloud Computing
Cyber Security
SOA
Data Mining
Semantic Web
DNA Computing
Gaming Models
Bio-Metrics
Nano Computing