Title：Solving the Salinity Control Problem in a Potable Water System Using Constraint Programming

Speaker：Jimmy Lee

Time：14：00,Jan.28,2010

Venue：Lecture Room, State Key Lab of Computer Science, Level 3 Building #5 

Abstract：

Salinity is the relative concentration of salts in water. In a city of southern China, the local water supply company pumps water from a nearby river for potable use. During the winter dry season, the intrusion of sea water raises the salinity of the river to a high level and affects approximately the daily life of 450,000 residents of the city. This talk reports the application of constraint programming (CP) to optimize the logistical operations of the raw water system so as to satisfy the daily water consumption requirement of the city and to keep the potable salinity below a desirable level for as many days as possible. CP is the key to the success of the project for its separation of concerns and powerful constraint language that allows for rapid construction of a functional prototype and production system. Flexibility and adaptiveness allow us to deal with our clients' many changes in the requirements. Deriving good variable and value ordering heuristics, and generating useful implied constraints, we demonstrate that branch-and-bound search with constraint propagation can cope with an optimization problem of large size and great difficulty.

Biograhy：

Jimmy Lee is a Professor and Graduate Division Head in the Department of Computer Science and Engineering, the Chinese University of Hong Kong. Jimmy's research focuses on the theory and practice of constraint satisfaction and optimization with applications in combinatorial optimization, scheduling, and resource allocation. In particular, he is interested in problem modeling, stochastic local search, symmetry breaking, global constraints, and over-constrained problems. In recent years, he started researching on novel Web-based learning platforms and accompanying pedagogies, particularly in the design and development of educational games. He is on the editorial board of the CONSTRAINTS journal, Springer, and the Journal of Discrete Algorithms, Elsevier. See http://www.cse.cuhk.edu.hk/~jlee/ for more details.