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arXiv cs/0509032cs.AIcond-mat.stat-mechcs.CC
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一种生成硬可满足序列的简单模型

A Simple Model to Generate Hard Satisfiable Instances

Ke Xu, Frederic Boussemart, Fred Hemery, Christophe Lecoutre

摘要:

本文试图进一步证明[Xu and Li,2000; 2003]提出的随机CSP实例模型具有理论和实际意义。事实上,这些被称为RB和RD的模型呈现了几个很好的特性。首先,生成任意arity的随机实例是相当容易的,因为在这样的实例中,没有特定的结构必须被集成,或者属性强制。然后,渐近相变的存在可以保证,同时施加有限的限制域的大小和约束的紧密性。在这种情况下,可以精确地定位阈值点,并且所有实例都保证在阈值处是硬的,即,具有指数树分辨率复杂度。接下来,形式化分析表明,它是可能的,以产生强制满足的实例,其硬度是类似于非强制满足的。这种分析是支持一些有代表性的结果,从密集的实验,我们已经进行了,使用完整和不完整的搜索方法。

英文摘要:

In this paper, we try to further demonstrate that the models of random CSP instances proposed by [Xu and Li, 2000; 2003] are of theoretical and practical interest. Indeed, these models, called RB and RD, present several nice features. First, it is quite easy to generate random instances of any arity since no particular structure has to be integrated, or property enforced, in such instances. Then, the existence of an asymptotic phase transition can be guaranteed while applying a limited restriction on domain size and on constraint tightness. In that case, a threshold point can be precisely located and all instances have the guarantee to be hard at the threshold, i.e., to have an exponential tree-resolution complexity. Next, a formal analysis shows that it is possible to generate forced satisfiable instances whose hardness is similar to unforced satisfiable ones. This analysis is supported by some representative results taken from an intensive experimentation that we have carried out, using complete and incomplete search methods.

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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