论文标题
可跟踪弱模型的分析特性
Analytic Properties of Trackable Weak Models
论文作者
论文摘要
我们提出了一些新的结果,该结果涉及在强烈的可跟踪弱模型中推断隐藏状态的可行性。在这里,弱模型是一个有向图,其中每个节点被分配一组颜色,该颜色可能会在访问该节点时发出。假设是与给定颜色序列一致的节点序列。如果此类假设的最坏情况数在序列长度中作为多项式增长,则据说弱模型是可追踪的。我们表明,强烈连接的可跟踪模型中的假设数量是由常数界定的,并给出了该常数的表达。我们还考虑了重建哪个分支在具有相同颜色外邻居的节点上进行的问题,并表明,如果模型牢固地连接和跟踪,则最终可以识别哪个分支。我们通过分配过渡概率和采用标准工具来分析马尔可夫链来说明这些属性。此外,我们根据弱模型的熵率提出了新的结果。这些定理表明,跟踪性和强连通性的组合极大地简化了重建哪些节点的任务。这项工作对任何问题都具有影响,可以用横穿彩色图的代理来描述,例如隐藏的马尔可夫模型(HMM)中隐藏状态的重建。
We present several new results on the feasibility of inferring the hidden states in strongly-connected trackable weak models. Here, a weak model is a directed graph in which each node is assigned a set of colors which may be emitted when that node is visited. A hypothesis is a node sequence which is consistent with a given color sequence. A weak model is said to be trackable if the worst case number of such hypotheses grows as a polynomial in the sequence length. We show that the number of hypotheses in strongly-connected trackable models is bounded by a constant and give an expression for this constant. We also consider the problem of reconstructing which branch was taken at a node with same-colored out-neighbors, and show that it is always eventually possible to identify which branch was taken if the model is strongly connected and trackable. We illustrate these properties by assigning transition probabilities and employing standard tools for analyzing Markov chains. In addition, we present new results for the entropy rates of weak models according to whether they are trackable or not. These theorems indicate that the combination of trackability and strong connectivity dramatically simplifies the task of reconstructing which nodes were visited. This work has implications for any problem which can be described in terms of an agent traversing a colored graph, such as the reconstruction of hidden states in a hidden Markov model (HMM).