期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
One-Class Support Vector Machine with Relative Comparisons 被引量:1
1
作者 顾弘 赵光宙 裘君 《Tsinghua Science and Technology》 SCIE EI CAS 2010年第2期190-197,共8页
One-class support vector machines (one-class SVMs) are powerful tools that are widely used in many applications. This paper describes a semi-supervised one-class SVM that uses supervision in terms of relative compar... One-class support vector machines (one-class SVMs) are powerful tools that are widely used in many applications. This paper describes a semi-supervised one-class SVM that uses supervision in terms of relative comparisons. The analysis uses a hypersphere version of one-class SVMs with a penalty term appended to the objective function. The method simultaneously finds the minimum sphere in the feature space that encloses most of the target points and considers the relative comparisons. The result is a standard convex quadratic programming problem, which can be solved by adapting standard methods for SVM training, i.e., sequential minimal optimization. This one-class SVM can be applied to semi-supervised clustering and multi-classification problems. Tests show that this method achieves higher accuracy and better generalization performance than previous SVMs. 展开更多
关键词 one-class support vector machines semi-supervised learning relative comparisons clustering multic/ass classification
原文传递
Relative volume comparison of Ricci flow 被引量:1
2
作者 Gang Tian Zhenlei Zhang 《Science China Mathematics》 SCIE CSCD 2021年第9期1937-1950,共14页
In this paper we derive a relative volume comparison of Ricci flow under a certain local curvature condition.It is a refinement of Perelman’s no local collapsing theorem in Perelman(2002).
关键词 Ricci flow relative volume comparison local entropy
原文传递
Online Metric Learning for Relevance Feedback in E-Commerce Image Retrieval Applications 被引量:1
3
作者 顾弘 赵光宙 裘君 《Tsinghua Science and Technology》 SCIE EI CAS 2011年第4期377-385,共9页
Relevance feedback plays a key role in multiple feature-based image retrieval applications. This paper describes an online metric learning approach for a set of ranking functions. In the feedback round, the most relev... Relevance feedback plays a key role in multiple feature-based image retrieval applications. This paper describes an online metric learning approach for a set of ranking functions. In the feedback round, the most relevant and most nonrelevant images related to the target image are selected to construct a relative comparison triplet. The weighting parameters of the multiple ranking functions are updated by minimizing a quadratic objective function constrained by the triplet. The approach unifies the learning algorithm for the most commonly used ranking functions. Thus, multiple features with their own ranking function can easily be employed in the ranking module without feature reconstruction. The method is computationally inexpensive and appropriate for large-scale e-commerce image retrieval applications. Customized ranking functions are well supported. Practically, simplified ranking functions yield better results when the number of query rounds is relatively small. Experiments with an image dataset from a real e-commerce platform show the superiority of the proposed approach. 展开更多
关键词 metric learning image ranking relevance feedback relative comparison
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部