凸风险最小化与条件概率估计Convex Risk Minimization and Conditional Probability Estimation |
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课程网址: | http://videolectures.net/colt2015_telgarsky_conditional_probabili... |
主讲教师: | Matus Telgarsky |
开课单位: | 加州大学 |
开课时间: | 2015-09-09 |
课程语种: | 英语 |
中文简介: | 这篇文章加强了凸风险最小化和条件概率估计之间的联系,这一联系在建立一致性结果方面已经非常显著(Friedman等人,2000;张,2004 b;巴特利特等人,2006)。具体地说,这篇文章首先表明了损失函数、预测器的线性空间和概率测度共同定义了一个唯一的最优条件概率模型,而且这个模型可以通过通常的凸风险最小化得到。这一结果在无限维的情况下得到了证明,从而给出了一个具体的收敛目标的非正则化方法,如提升,可能没有最小化。其次,该收敛结果在有限多个维度上得到改进,以保持经验风险最小化。这种一致收敛的结果不依赖于其预测器的范数,因此可以证明最小正则化优化方案的实际有效性。 |
课程简介: | This manuscript strengthens the link between convex risk minimization and conditional probability estimation, a connection already notable for establishing consistency results (Friedman et al., 2000; Zhang, 2004b; Bartlett et al., 2006). Specifically, this manuscript first shows that a loss function, linear space of predictors, and probability measure together define a unique optimal conditional probability model, moreover one which may be attained by the usual convex risk minimization. This result is proved in infinite dimensions, and thus gives a concrete convergence target for unregularized methods like boosting which can fail to have minimizers. Second, this convergence result is refined in finitely many dimensions to hold for empirical risk minimization. This uniform convergence result exhibits no dependence on the norms of its predictors, and thus can justify the practical effectiveness of minimally-regularized optimization schemes. |
关 键 词: | 凸风险最小化; 条件概率估计; 收敛目标 |
课程来源: | 视频讲座网 |
数据采集: | 2022-12-05:chenjy |
最后编审: | 2023-05-11:chenjy |
阅读次数: | 35 |