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在基于相似性的投影空间学习[ ]转移的有用性

On the Usefulness of Similarity based Projection Spaces for Transfer Learning
课程网址: http://videolectures.net/simbad2011_morvant_transfer/  
主讲教师: Emilie Morvant
开课单位: 马赛基础计算机实验室
开课时间: 2011-08-17
课程语种: 法语
中文简介:
相似度函数广泛用于许多机器学习或模式识别任务中。我们在此考虑Balcan等人提出的最近的二元分类框架,允许基于良好的相似性函数在潜在的非几何空间中学习。该框架是支持向量机中使用的内核概念的概括,其允许使用不需要是正半有限也不对称的相似性函数。然后使用相似性来定义显式投影空间,其中可以学习具有良好泛化属性的线性分类器。在本文中,我们建议通过实验研究基于相似性的投影空间对转移学习问题的有用性。更确切地说,我们考虑域适应的问题,其中产生学习数据和测试数据的分布有些不同。我们认为没有关于测试标签的信息。我们表明,考虑到测试数据的良好相似性函数的简单重整化允许我们学习在目标分布上更难以适应问题的分类器。此外,当我们尝试将基于相似性的投影空间规则化以便更接近两个分布时,这种归一化总是有助于改进模型。我们提供有关玩具问题和真实图像注释任务的实验。
课程简介: Similarity functions are widely used in many machine learning or pattern recognition tasks. We consider here a recent framework for binary classifi cation, proposed by Balcan et al., allowing to learn in a potentially non geometrical space based on good similarity functions. This framework is a generalization of the notion of kernels used in support vector machines in the sense that allows one to use similarity functions that do not need to be positive semi-de finite nor symmetric. The similarities are then used to define an explicit projection space where a linear classifi er with good generalization properties can be learned. In this paper, we propose to study experimentally the usefulness of similarity based projection spaces for transfer learning issues. More precisely, we consider the problem of domain adaptation where the distributions generating learning data and test data are somewhat di fferent. We stand in the case where no information on the test labels is available. We show that a simple renormalization of a good similarity function taking into account the test data allows us to learn classifi ers more performing on the target distribution for difficult adaptation problems. Moreover, this normalization always helps to improve the model when we try to regularize the similarity based projection space in order to move closer the two distributions. We provide experiments on a toy problem and on a real image annotation task.
关 键 词: 模式识别; 计算机科学; 机器学习; 监督学习
课程来源: 视频讲座网
最后编审: 2020-05-31:吴雨秋(课程编辑志愿者)
阅读次数: 51