一种基于吉布斯采样算法的马尔可夫背景模型编码的研究
n Improved Gibbs Sampling Based Method with Markov chain background Model for Motif Discovery
当前有许多用于预测模体的算法,但没有一种算法能有效地应用在所有场合。目前在模体查找方面使用最多的是改进吉布斯采样算法的方法,最有效的方法就是采用3阶马尔可夫背景模型来去除噪声,体现临近核苷酸对模体元素的影响。然而在背景模型的条件概率值实现上还存在一些讨论,本文提出一种新颖的编码方式来实现3阶马尔可夫背景模型。可以较为便捷地建立需要的马尔可夫背景参数。同时引入了马尔可夫因子的概念,改进了最大后验判定概率(MAP)的算法,从而有效降低了数值计算的误差影响,改进了数值计算的算法,使背景模型的数值敏感性降低。数值试验表明该算法有效改善了吉布斯采样算法的局部收敛性,提高了收敛的速度和效率,降低了预测假阳性。
Many motif-finding programs have been developed, but no program is clearly superior in all situations. In this paper, an improved Gibbs sample algorithm is proposed to discover motif with the new method markov chain background. The improved approach can overcome the local convergence of Gibbs sample algorithm and also can accelerate the speed of the convergent course. A new method is been proposed to encode the candidate motif. This method make the modeling of the background with markov chain easily and conveniently. The markov factor is adapted to reduce the error which have a great fluence on the result of the computer. The verified biologcal data are used to test the feasibility and effectiveness of improved approach. Compared with results given by the experiment, our algorithm raise effectively the accuracy, flexibility and stability for the motif discovery.
饶妮妮、匡斌、袁祚勇、韩凤君
分子生物学计算技术、计算机技术
吉布斯采样,模体,位置权重矩阵 模体寻找 马尔可夫背景模型
Gibbs samplingmotifPWMMotif discoveryMarkov chain Background
饶妮妮,匡斌,袁祚勇,韩凤君 .一种基于吉布斯采样算法的马尔可夫背景模型编码的研究[EB/OL].(2007-01-24)[2025-08-18].http://www.paper.edu.cn/releasepaper/content/200701-336.点此复制
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