集群序列数据与混合马尔科夫链与共变量使用多个简单的受约束优化程序 (MSiCOR)
Priyam Das1, Deborshee Sen2, Debsurya De3
1Department of Biostatistics, Virginia Commonwealth University, Richmond, VA.
概括
一种新的全局优化方法提高了混合马尔科夫模型 (MMM) 对聚类事件序列的性能,超过了预期最大化 (EM) 算法. 该技术用于根据治疗数据识别多发性硬化症 (MS) 患者的子组.
科学领域:
- 计算统计学 计算统计学
- 机器学习 机器学习
- 生物统计学 生物统计学
背景情况:
- 混合马尔科夫模型 (MMM) 对聚类事件序列有价值,但由于多模式性,在概率最大化方面面临挑战.
- 通常用于MMM参数估计的预期-最大化 (EM) 算法不能保证趋同.
- 在受约束的参数空间上最大化MMM概率带来了显著的计算困难.
研究的目的:
- 开发一种强大的全球优化技术,以最大限度地提高混合马尔科夫模型的可能性.
- 为了提高混合马尔科夫模型在聚类复杂事件序列的性能.
- 根据疾病修饰疗法 (DMT) 序列和临床共变量,将改进的MMM应用于聚类多发性硬化症 (MS) 患者.
主要方法:
- 开发了一种基于模式搜索的全局优化技术,能够优化对象函数的简单集合.
- 使用这种技术来最大限度地提高混合马尔科夫模型的概率函数.
- 利用DMT处方数据和相关的临床特征 (共变量) 应用增强型MMM对MS患者进行集群.
主要成果:
- 提出的基于模式搜索的全球优化方法,与现有的全球优化技术相比,表现优越.
- 在模拟实验中,新方法在混合马尔科夫模型估计中超过了预期最大化 (EM) 算法.
- 对多发性硬化症患者进行集群研究,发现基于DMT序列和共变体的三个不同的子组,在各个集群中发现了显著差异.
结论:
- 基于模式搜索的新型全球优化技术有效地解决了混合马尔科夫模型概率最大化的挑战.
- 与传统的EM算法相比,这种方法为MMM参数估计提供了更好的准确性和可靠性.
- 对多发性硬化患者数据的应用成功确定了临床相关的子组,为个性化治疗策略铺平了道路.
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