In a randomized study, subjects are randomly assigned to either a treated group or a control group. Random assignment ensures that the distribution of the covariates is the same in both groups and that the treatment effect can be estimated by directly comparing the outcomes for the subjects in the two groups. In contrast, subjects in an observational study are not randomly assigned. In order to...

Matching is a central problem in image analysis and pattern recognition. In order to develop a matching algorithm that provides the optimal fit (i.e. “center-on” fit attempting to position the model points at equal spacing from the target image) between the model and distorted target images, a hierarchical modified Chamfer matching system with the simulated annealing is proposed in this paper. ...

The problem of optimal approximation of members of a vector space by a linear combination of members of a large overcomplete library of vectors is of importance in many areas including image and video coding, image analysis, control theory, and statistics. Finding the optimal solution in the general case is mathematically intractable. Matching pursuit, and its orthogonal version, provide greedy...

Consider a two-stage matching problem, where edges of an input graph are revealed in two stages (batches) and in each stage we have to immediately and irrevocably extend our matching using the edges from that stage. The natural greedy algorithm is half competitive. Even though there is a huge literature on online matching in adversarial vertex arrival model, no positive results were previously ...

Perhaps the two most fundamental well-solved models in combinatorial optimization are the optimal matching problem and the optimal matroid intersection problem. We review the basic results for both, and describe some more recent advances. Then we discuss extensions of these models, in particular, two recent ones—jump systems and path-matchings.

Due to physiology and linguistic difference between speakers, the spectrum pattern for the same phoneme of two speakers can be quite dissimilar. Without appropriate alignment on the frequency axis, the misalignment will reduce the modeling efficiency resutling in performance degradation. In this paper, a novel data-driven framework is proposed to build the alignment of the frequency axes of two...

For the assignment game, we analyze the following mechanism: sellers, simultaneously, fix their prices first; then buyers, sequentially, decide which object to buy, if any, among the remaining objects. The first phase of the game determines the potential prices, while the second phase determines the actual matching. We prove that the set of subgame perfect equilibria in pure strategies in the s...

We study second-degree price discrimination in markets where the product traded by the monopolist is access to other agents. We derive necessary and suffi cient conditions for the welfareand the profit-maximizing mechanisms to employ a single network or a menu of non-exclusive networks. We characterize the optimal matching schedules under a wide range of preferences, derive implications for pri...