Inferring Rankings Using Constrained Sensing
Inferring Rankings Using Constrained Sensing
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DOI:
10.1109/tit.2011.2165827
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发表时间:
2011-11-01
影响因子:
2.5
通讯作者:
Shah, Devavrat
中科院分区:
文献类型:
--
作者:
Jagabathula, Srikanth;Shah, Devavrat
We consider the problem of recovering a function over the space of permutations (or, the symmetric group) over n elements from given partial information; the partial information we consider is related to the group theoretic Fourier Transform of the function. This problem naturally arises in several settings such as ranked elections, multi-object tracking, ranking systems, and recommendation systems. Inspired by the work of Donoho and Stark in the context of discrete-time functions, we focus on non-negative functions with a sparse support (support size infinity. l(0) optimization is computationally hard. Therefore, the popular compressive sensing literature considers solving the convex relaxation, l(1) optimization, to find the sparsest solution. However, we show that l(1) optimization fails to recover a function (even with constant sparsity) generated using the random model with a high probability as n -> infinity. In order to overcome this problem, we propose a novel iterative algorithm for the recovery of functions that satisfy the sufficient conditions. Finally, using an Information Theoretic framework, we study necessary conditions for exact recovery to be possible.