Support Vector Machines
Machine learning Training in Hyderabad
Work towards building a strong knowledge based career foundation in the leading analytics platform of Machine Learning by availing our Analytics Path top-notch Machine Learning Training In Hyderabad. Our experts trainers will be working towards transforming our students into complete career ready professionals. By the time of course completion, our students will become well capable to handling all the real-world complex challenges of the Machine Learning domain. Students will be gaining expertise towards working on the advanced concepts like Support Vector Machines, Naive Bayes Classification, Logistic Regression, Decision Tree Algorithms, K-Means Clustering and more. Machine Learning is the most challenging & innovative platform in the present days analytics domain.
Chapter 2 : SVM (Support Vector Machine) -- Theory
Welcome to the second stepping stone of Supervised Machine Learning. Again, this chapter is divided into two parts. Part 2 (here) we take on small coding exercise challenge. If you haven't read the Naive Bayes, I would suggest you to read it thorough here. A Support Vector Machine (SVM) is a discriminative classifier formally defined by a separating hyperplane.
Support vector clustering - Scholarpedia
The objective of clustering is to partition a data set into groups according to some criterion in an attempt to organize data into a more meaningful form. There are many ways of achieving this goal. Clustering may proceed according to some parametric model or by grouping points according to some distance or similarity measure as in hierarchical clustering. A natural way to put cluster boundaries is in regions in data space where there is little data, i.e. in "valleys" in the probability distribution of the data. This is the path taken in support vector clustering (SVC), which is based on the support vector approach (see Ben-Hur et al., 2001).
Individuals have unique muscle activation signatures as revealed during gait and pedaling
Although it is known that the muscle activation patterns used to produce even simple movements can vary between individuals, these differences have not been considered to prove the existence of individual muscle activation strategies (or signatures). We used a machine learning approach (support vector machine) to test the hypothesis that each individual has unique muscle activation signatures. Eighty participants performed a series of pedaling and gait tasks, and 53 of these participants performed a second experimental session on a subsequent day. Myoelectrical activity was measured from eight muscles: vastus lateralis and medialis, rectus femoris, gastrocnemius lateralis and medialis, soleus, tibialis anterior, and biceps femoris-long head. The classification task involved separating data into training and testing sets.
Vector
They are also relied upon heavily to make up the basis for some machine learning techniques as well. One example in particular is support vector machines. A support vector machine analyzes vectors across an n-dimensional space to find the optimal hyperplane for a given data set. In essence, a support vector machine will attempt to find a line that have the maximum distance between data sets of both classes. This allows for future data points to be classified with ore confidence, due to increased reinforcement.
Bounding Data-driven Model Errors in Power Grid Analysis
Liu, Yuxiao, Xu, Bolun, Botterud, Audun, Zhang, Ning, Kang, Chongqing
Data-driven models analyze power grids under incomplete physical information, and their accuracy has been mostly validated empirically using certain training and testing datasets. This paper explores error bounds for data-driven models under all possible training and testing scenarios, and proposes an evaluation implementation based on Rademacher complexity theory. We answer key questions for data-driven models: how much training data is required to guarantee a certain error bound, and how partial physical knowledge can be utilized to reduce the required amount of data. Our results are crucial for the evaluation and application of data-driven models in power grid analysis. We demonstrate the proposed method by finding generalization error bounds for two applications, i.e. branch flow linearization and external network equivalent under different degrees of physical knowledge. Results identify how the bounds decrease with additional power grid physical knowledge or more training data.
Jupyter Notebooks: Fundamentals of Machine Learning and Deep Learning
Jupyter notebooks that walk you through the fundamentals of Machine Learning and Deep Learning in Python using Scikit-Learn, Keras and TensorFlow 2. You can access this material here. For other free tutorials (including from Berkeley, Harvard, Columbia, Google, Microsoft and so on), follow this link.
Exploring Kernel Functions in the Softmax Layer for Contextual Word Classification
Gao, Yingbo, Herold, Christian, Wang, Weiyue, Ney, Hermann
Prominently used in support vector machines and logistic regressions, kernel functions (kernels) can implicitly map data points into high dimensional spaces and make it easier to learn complex decision boundaries. In this work, by replacing the inner product function in the softmax layer, we explore the use of kernels for contextual word classification. In order to compare the individual kernels, experiments are conducted on standard language modeling and machine translation tasks. We observe a wide range of performances across different kernel settings. Extending the results, we look at the gradient properties, investigate various mixture strategies and examine the disambiguation abilities.
Harnessing the Power of Infinitely Wide Deep Nets on Small-data Tasks
Arora, Sanjeev, Du, Simon S., Li, Zhiyuan, Salakhutdinov, Ruslan, Wang, Ruosong, Yu, Dingli
Recent research shows that the following two models are equivalent: (a) infinitely wide neural networks (NNs) trained under l2 loss by gradient descent with infinitesimally small learning rate (b) kernel regression with respect to so-called Neural Tangent Kernels (NTKs) (Jacot et al., 2018). An efficient algorithm to compute the NTK, as well as its convolutional counterparts, appears in Arora et al. (2019a), which allowed studying performance of infinitely wide nets on datasets like CIFAR-10. However, super-quadratic running time of kernel methods makes them best suited for small-data tasks. We report results suggesting neural tangent kernels perform strongly on low-data tasks. 1. On a standard testbed of classification/regression tasks from the UCI database, NTK SVM beats the previous gold standard, Random Forests (RF), and also the corresponding finite nets. 2. On CIFAR-10 with 10 - 640 training samples, Convolutional NTK consistently beats ResNet-34 by 1% - 3%. 3. On VOC07 testbed for few-shot image classification tasks on ImageNet with transfer learning (Goyal et al., 2019), replacing the linear SVM currently used with a Convolutional NTK SVM consistently improves performance. 4. Comparing the performance of NTK with the finite-width net it was derived from, NTK behavior starts at lower net widths than suggested by theoretical analysis(Arora et al., 2019a). NTK's efficacy may trace to lower variance of output.
Understanding and Quantifying Adversarial Examples Existence in Linear Classification
State-of-art deep neural networks (DNN) are vulnerable to attacks by adversarial examples: a carefully designed small perturbation to the input, that is imperceptible to human, can mislead DNN. To understand the root cause of adversarial examples, we quantify the probability of adversarial example existence for linear classifiers. Previous mathematical definition of adversarial examples only involves the overall perturbation amount, and we propose a more practical relevant definition of strong adversarial examples that separately limits the perturbation along the signal direction also. We show that linear classifiers can be made robust to strong adversarial examples attack in cases where no adversarial robust linear classifiers exist under the previous definition. The quantitative formulas are confirmed by numerical experiments using a linear support vector machine (SVM) classifier. The results suggest that designing general strong-adversarial-robust learning systems is feasible but only through incorporating human knowledge of the underlying classification problem.