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arXiv 1801.02701cs.ITmath.IT
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群测试的新的不可能性结果

Novel Impossibility Results for Group-Testing

Abhishek Agarwal, Sidharth Jaggi, Arya Mazumdar

摘要:

在这项工作中,我们证明了非平凡的不可能的结果,也许是最简单的非线性估计问题,{ \it组测试}(GT),通过最近开发的Madiman-Tetali不等式。分组测试涉及通过$t$ {分离/合并}测量(“分组测试”)从一组$n$项目中识别隐藏的一组$d$缺陷项目。我们认为线性稀疏制度,即$d = δn$的任何常数$δ>0$,迄今很少探索(虽然自然)制度。在一个标准的信息理论的设置,测试需要是非自适应的,并允许一个小概率的重建错误,我们的下限$t$是{ \it第一},提高了经典的计数下限,$t/n \geq H(δ)$,其中$H(\cdot)$是二进制熵函数。作为我们结果的推论,我们表明:(i)对于$δ\gtrsim 0.347$,个体测试基本上是最优的,即,$t \geq n(1-o(1))$ ;以及(ii)存在{自适应间隙},因为对于$δ\in (0.3471,0.3819)$,已知的{自适应} GT算法需要比$n$测试更少的测试来重建${\cal D}$,而我们的界限意味着最佳非自适应算法必须本质上是每个元素的单独测试。也许最重要的是,我们的工作提供了一个框架,组合和信息理论的方法来推导出非平凡的各种非线性估计问题的下限。

英文摘要:

In this work we prove non-trivial impossibility results for perhaps the simplest non-linear estimation problem, that of {\it Group Testing} (GT), via the recently developed Madiman-Tetali inequalities. Group Testing concerns itself with identifying a hidden set of $d$ defective items from a set of $n$ items via $t$ {disjunctive/pooled} measurements ("group tests"). We consider the linear sparsity regime, i.e. $d = δn$ for any constant $δ>0$, a hitherto little-explored (though natural) regime. In a standard information-theoretic setting, where the tests are required to be non-adaptive and a small probability of reconstruction error is allowed, our lower bounds on $t$ are the {\it first} that improve over the classical counting lower bound, $t/n \geq H(δ)$, where $H(\cdot)$ is the binary entropy function. As corollaries of our result, we show that (i) for $δ\gtrsim 0.347$, individual testing is essentially optimal, i.e., $t \geq n(1-o(1))$; and (ii) there is an {adaptivity gap}, since for $δ\in (0.3471,0.3819)$ known {adaptive} GT algorithms require fewer than $n$ tests to reconstruct ${\cal D}$, whereas our bounds imply that the best nonadaptive algorithm must essentially be individual testing of each element. Perhaps most importantly, our work provides a framework for combining combinatorial and information-theoretic methods for deriving non-trivial lower bounds for a variety of non-linear estimation problems.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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