Current Research
My current research involves developing scalable combinatorial optimization algorithms for solving static and dynamic
resource
allocation problems. Most of these problems are intimately related to a class of combinatorial resource allocation problems that
have been studied extensively in various formulations such as the minimum distortion problem in data compression,
facility location assignments, optimal quadrature rules and discretization of partial differential equations, pattern
recognition, drug discovery, neural networks, and clustering analysis. In contrast, these problems are
relatively recent in the control literature, having arisen in coarse quantization, coverage control, mobile sensing
networks, and motion coordination algorithms.
Computationally, these problems are typically complex and time intensive, if not intractable. Complexity is further complicated by their inherent non-convex nature, and the curse of dimensionality. Additionally, the huge size of the underlying datasets, and distributed implementation calls for algorithms that are scalable.
We have used tools from information theory, graph theory, statistical physics and control theory to design such algorithms. We have implemented a Maximum Entropy based framework, and augmented it with additional constraints for addressing the issues of scalability and distributed implementation. We have successfully implemented these scalable algorithms for solving the library selection problems in combinatorial drug-discovery [1], by simultaneously addressing the key issues of diversity, representativeness, inclusion/exclusion and scalabilty. Similar framework is also used for solving the state-space discretization problem in quantized control.
Presently, we are working on the coverage and tracking problem with mobile sites and resources. We have developed a Maximum Entropy based algorithm for solving this dynamic locational optimization problem [2]. The emphasis is on developing algorithms that avoid local minima and are insensitive to the initial placement of resources. The algorithm ensures that the coverage metric (between the mobile sites and resources) is continuously improved.
Publications
- Sharma, P., Salapaka, S., and Beck, C., A Scalable Approach to Combinatorial Library Design for Drug Discovery
J. Chem. Inf. Model., 48, 1, 27 - 41, 2008. - Sharma, P., Salapaka, S., and Beck, C., Entropy Based Algorithm for Combinatorial Optimization Problems with
Mobile
Sites and Resources
Proc. of American Control Conference, 2008. - Sharma, P., Salapaka, S., and Beck, C., A Maximum Entropy Based Scalable Algorithm for Resource Allocation
Problems
Proc. of American Control Conference, 516-521, 2007. - Sharma, P., Salapaka, S., and Beck, C., A Scalable Deterministic Annealing Algorithm for Resource Allocation
Problems
Proc. of American Control Conference, 3092-3097, 2006. - Sharma, P., Salapaka, S., and Beck, C., A Deterministic Annealing Approach to Combinatorial Library Design for
Drug Discovery
Proc. of American Control Conference, 979- 984 vol. 2, 2005. - Sharma, P., and Beck, C., Modelling and distributed control of mobile offshore bases
Proc. of American Control Conference, 5238- 5243 vol.6, 2004. - Modelling and Distributed Control of Spatial Array Systems - Advisor: Prof. Carolyn Beck.
M.S. Thesis
