Results 1  10
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148
Svmknn: Discriminative nearest neighbor classification for visual category recognition
 in CVPR
, 2006
"... We consider visual category recognition in the framework of measuring similarities, or equivalently perceptual distances, to prototype examples of categories. This approach is quite flexible, and permits recognition based on color, texture, and particularly shape, in a homogeneous framework. While n ..."
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Cited by 210 (7 self)
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We consider visual category recognition in the framework of measuring similarities, or equivalently perceptual distances, to prototype examples of categories. This approach is quite flexible, and permits recognition based on color, texture, and particularly shape, in a homogeneous framework. While nearest neighbor classifiers are natural in this setting, they suffer from the problem of high variance (in biasvariance decomposition) in the case of limited sampling. Alternatively, one could use support vector machines but they involve timeconsuming optimization and computation of pairwise distances. We propose a hybrid of these two methods which deals naturally with the multiclass setting, has reasonable computational complexity both in training and at run time, and yields excellent results in practice. The basic idea is to find close neighbors to a query sample and train a local support vector machine that preserves the distance function on the collection of neighbors. Our method can be applied to large, multiclass data sets for which it outperforms nearest neighbor and support vector machines, and remains efficient when the problem becomes intractable for support vector machines. A wide variety of distance functions can be used and our experiments show stateoftheart performance on a number of benchmark data sets for shape and texture classification (MNIST, USPS, CUReT) and object recognition (Caltech101). On Caltech101 we achieved a correct classification rate of 59.05%(±0.56%) at 15 training images per class, and 66.23%(±0.48%) at 30 training images. 1.
In defense of onevsall classification
 Journal of Machine Learning Research
, 2004
"... Editor: John ShaweTaylor We consider the problem of multiclass classification. Our main thesis is that a simple “onevsall ” scheme is as accurate as any other approach, assuming that the underlying binary classifiers are welltuned regularized classifiers such as support vector machines. This the ..."
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Cited by 202 (0 self)
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Editor: John ShaweTaylor We consider the problem of multiclass classification. Our main thesis is that a simple “onevsall ” scheme is as accurate as any other approach, assuming that the underlying binary classifiers are welltuned regularized classifiers such as support vector machines. This thesis is interesting in that it disagrees with a large body of recent published work on multiclass classification. We support our position by means of a critical review of the existing literature, a substantial collection of carefully controlled experimental work, and theoretical arguments.
The Entire Regularization Path for the Support Vector Machine
, 2004
"... In this paper we argue that the choice of the SVM cost parameter can be critical. We then derive an algorithm that can fit the entire path of SVM solutions for every value of the cost parameter, with essentially the same computational cost as fitting one SVM model. ..."
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Cited by 148 (9 self)
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In this paper we argue that the choice of the SVM cost parameter can be critical. We then derive an algorithm that can fit the entire path of SVM solutions for every value of the cost parameter, with essentially the same computational cost as fitting one SVM model.
Learning the kernel function via regularization
 Journal of Machine Learning Research
, 2005
"... We study the problem of finding an optimal kernel from a prescribed convex set of kernels K for learning a realvalued function by regularization. We establish for a wide variety of regularization functionals that this leads to a convex optimization problem and, for square loss regularization, we ch ..."
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Cited by 96 (7 self)
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We study the problem of finding an optimal kernel from a prescribed convex set of kernels K for learning a realvalued function by regularization. We establish for a wide variety of regularization functionals that this leads to a convex optimization problem and, for square loss regularization, we characterize the solution of this problem. We show that, although K may be an uncountable set, the optimal kernel is always obtained as a convex combination of at most m+2 basic kernels, where m is the number of data examples. In particular, our results apply to learning the optimal radial kernel or the optimal dot product kernel. 1.
Kernel Logistic Regression and the Import Vector Machine
 Journal of Computational and Graphical Statistics
, 2001
"... The support vector machine (SVM) is known for its good performance in binary classification, but its extension to multiclass classification is still an ongoing research issue. In this paper, we propose a new approach for classification, called the import vector machine (IVM), which is built on ker ..."
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Cited by 91 (3 self)
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The support vector machine (SVM) is known for its good performance in binary classification, but its extension to multiclass classification is still an ongoing research issue. In this paper, we propose a new approach for classification, called the import vector machine (IVM), which is built on kernel logistic regression (KLR). We show that the IVM not only performs as well as the SVM in binary classification, but also can naturally be generalized to the multiclass case. Furthermore, the IVM provides an estimate of the underlying probability. Similar to the "support points" of the SVM, the IVM model uses only a fraction of the training data to index kernel basis functions, typically a much smaller fraction than the SVM. This gives the IVM a computational advantage over the SVM, especially when the size of the training data set is large. 1
Classification of Multiple Cancer Types by Multicategory Support Vector Machines Using Gene Expression Data
 JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION
, 2002
"... Monitoring gene expression profiles is a novel approach in cancer diagnosis. Several studies showed that prediction of cancer types using gene expression data is promising and very informative. The Support Vector Machine (SVM) is one of the classification methods successfully applied to the cancer d ..."
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Cited by 88 (4 self)
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Monitoring gene expression profiles is a novel approach in cancer diagnosis. Several studies showed that prediction of cancer types using gene expression data is promising and very informative. The Support Vector Machine (SVM) is one of the classification methods successfully applied to the cancer diagnosis problems using gene expression data. However, its optimal extension to more than two classes was not obvious, which might impose limitations in its application to multiple tumor types. In this paper, we analyze a couple of published multiple cancer types data sets by the multicategory SVM, which is a recently proposed extension of the binary SVM.
Everything Old Is New Again: A Fresh Look at Historical Approaches
 in Machine Learning. PhD thesis, MIT
, 2002
"... 2 Everything Old Is New Again: A Fresh Look at Historical ..."
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Cited by 88 (6 self)
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2 Everything Old Is New Again: A Fresh Look at Historical
Support vector machines and the Bayes rule in classification
 Data Mining Knowledge Disc
, 2002
"... Abstract. The Bayes rule is the optimal classification rule if the underlying distribution of the data is known. In practice we do not know the underlying distribution, and need to “learn ” classification rules from the data. One way to derive classification rules in practice is to implement the Bay ..."
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Cited by 84 (13 self)
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Abstract. The Bayes rule is the optimal classification rule if the underlying distribution of the data is known. In practice we do not know the underlying distribution, and need to “learn ” classification rules from the data. One way to derive classification rules in practice is to implement the Bayes rule approximately by estimating an appropriate classification function. Traditional statistical methods use estimated log odds ratio as the classification function. Support vector machines (SVMs) are one type of large margin classifier, and the relationship between SVMs and the Bayes rule was not clear. In this paper, it is shown that the asymptotic target of SVMs are some interesting classification functions that are directly related to the Bayes rule. The rate of convergence of the solutions of SVMs to their corresponding target functions is explicitly established in the case of SVMs with quadratic or higher order loss functions and spline kernels. Simulations are given to illustrate the relation between SVMs and the Bayes rule in other cases. This helps understand the success of SVMs in many classification studies, and makes it easier to compare SVMs and traditional statistical methods.
Ranking with large margin principle: Two approaches
 In Proceedings of Advances in Neural Information Processing Systems
, 2002
"... We discuss the problem of ranking instances with the use of a “large margin ” principle. We introduce two main approaches: the first is the “fixed margin ” policy in which the margin of the closest neighboring classes is being maximized — which turns out to be a direct generalization of SVM to ranki ..."
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Cited by 65 (0 self)
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We discuss the problem of ranking instances with the use of a “large margin ” principle. We introduce two main approaches: the first is the “fixed margin ” policy in which the margin of the closest neighboring classes is being maximized — which turns out to be a direct generalization of SVM to ranking learning. The second approach allows for different margins where the sum of margins is maximized. This approach is shown to reduce toSVM when the number of classes. Both approaches are optimal in size of where is the total number of training examples. Experiments performed on visual classification and “collaborative filtering ” show that both approaches outperform existing ordinal regression algorithms applied for ranking and multiclass SVM applied to general multiclass classification. 1
Combining svms with various feature selection strategies
 Taiwan University
, 2005
"... Feature selection is an important issue in many research areas. There are some reasons for selecting important features such as reducing the learning time, improving the accuracy, etc. This thesis investigates the performance of combining support vector machines (SVM) and various feature selection s ..."
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Cited by 58 (0 self)
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Feature selection is an important issue in many research areas. There are some reasons for selecting important features such as reducing the learning time, improving the accuracy, etc. This thesis investigates the performance of combining support vector machines (SVM) and various feature selection strategies. The first part of the thesis mainly describes the existing feature selection methods and our experience on using those methods to attend a competition. The second part studies more feature selection strategies using the SVM. ii �ì��¬¡÷ � ��å�ç¢�ß��� � selection)��¥ì����£��È�� ����È������Ú���£����æÁ ç��£�����û�� ì�Öù�¡�È��(feature é£�æÁ©Â����℄���� � �Ü � ����Æ���È��℄�¡��û���℄�ø�¢�§���� �(Support Vector Machine) iii