Dependent rounding is a useful technique for optimization problems with hard budget constraints. This framework naturally leads to negative correlation properties. However, what if an application naturally calls for dependent rounding on the one hand, and desires positive correlation on the other? More generally, we develop algorithms that guarantee the… (More)
Knapsack median is a generalization of the classic k-median problem in which we replace the cardinality constraint with a knapsack constraint. It is currently known to be 32-approximable. We improve on the best known algorithms in several ways, including adding randomization and applying spar-sification as a preprocessing step. The latter improvement… (More)
We describe the design, implementation, and evaluation of EMBERS, an automated, 24x7 continuous system for forecasting civil unrest across 10 countries of Latin America using open source indicators such as tweets, news sources, blogs, economic indicators, and other data sources. Unlike retrospective studies, EMBERS has been making forecasts into the future… (More)
Rounding. Dependent rounding is useful. Negative correlation is useful. Near-independence used. Entropy maximization often yields useful distributions. Goal of this paper is to explore if entropy maximization can be used to obtain distributions with near-independence properties.
k-median is a classic optimization problem which has been studied extensively in the last few decades. The current best known approximation ratio for this problem is (2.675 +). A more generalized version of this problem also considers the capacities of the given facilities. That is, each facility cannot serve more clients than its own capacity.… (More)
In this paper, we study a real-world variant of the Vehicle Routing Problem, arising from the work of distributing products of an industrial corporation. Given information about vehicles, depots, types of products, and the location of customers, we wish to determine the minimum number of vehicles required to pick up and deliver products to customers within… (More)
In this paper, we represent an empirical study of multipass decoding for Vietnamese LVCSR. We report our experiments with N-best, lattice and consensus decoding on the VNBN data. Results from this study indicate that our acoustic model for Vietnamese was precise. The results could be investigated in further steps to improve the performance of our system.