دانلود مقاله ISI انگلیسی شماره 29016
عنوان فارسی مقاله

# دیدگاه هندسی در یادگیری ساختار شبکه های بیزی

کد مقاله سال انتشار مقاله انگلیسی ترجمه فارسی تعداد کلمات
29016 2010 14 صفحه PDF سفارش دهید 10998 کلمه
خرید مقاله
پس از پرداخت، فوراً می توانید مقاله را دانلود فرمایید.
عنوان انگلیسی
A geometric view on learning Bayesian network structures
منبع

Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)

Journal : International Journal of Approximate Reasoning, Volume 51, Issue 5, June 2010, Pages 573–586

کلمات کلیدی
یادگیری شبکه های بیزی - استاندارد - محله ورود به مطالعه - محله هندسی - الگوریتم -
کلمات کلیدی انگلیسی
Learning Bayesian networks, Standard imset, Inclusion neighborhood, Geometric neighborhood, GES algorithm,
پیش نمایش مقاله

#### چکیده انگلیسی

We recall the basic idea of an algebraic approach to learning Bayesian network (BN) structures, namely to represent every BN structure by a certain (uniquely determined) vector, called a standard imset. The main result of the paper is that the set of standard imsets is the set of vertices (=extreme points) of a certain polytope. Motivated by the geometric view, we introduce the concept of the geometric neighborhood for standard imsets, and, consequently, for BN structures. Then we show that it always includes the inclusion neighborhood, which was introduced earlier in connection with the greedy equivalence search (GES) algorithm. The third result is that the global optimum of an affine function over the polytope coincides with the local optimum relative to the geometric neighborhood. To illustrate the new concept by an example, we describe the geometric neighborhood in the case of three variables and show it differs from the inclusion neighborhood. This leads to a simple example of the failure of the GES algorithm if data are not “generated” from a perfectly Markovian distribution. The point is that one can avoid this failure if the search technique is based on the geometric neighborhood instead. We also found out what is the geometric neighborhood in the case of four and five variables.

خرید مقاله
پس از پرداخت، فوراً می توانید مقاله را دانلود فرمایید.