Genre
Jackknife logistic and linear regression for clustering and predictions
This article discusses a far more general version of the technique described in our article The best kept secret about regression. Here we adapt our methodology so that it applies to data sets with a more complex structure, in particular with highly correlated independent variables. Our goal is to produce a regression tool that can be used as a black box, be very robust and parameter-free, and usable and easy-to-interpret by non-statisticians. It is part of a bigger project: automating many fundamental data science tasks, to make it easy, scalable and cheap for data consumers, not just for data experts. Readers are invited to further formalize the technology outlined here, and challenge my proposed methodology.
From the Turing Test to Deep Learning: Artificial Intelligence Goes Mainstream - Computer Business Review
This year, the Association for Computing Machinery (ACM) celebrates 50 years of the ACM Turing Award, the most prestigious technical award in the computing industry. The Turing Award, generally regarded as the'Nobel Prize of computing', is an annual prize awarded to "an individual selected for contributions of a technical nature made to the computing community". In celebration of the 50 year milestone, renowned computer scientist Melanie Mitchell spoke to CBR's Ellie Burns about artificial intelligence (AI) – the biggest breakthroughs, hurdles and myths surrounding the technology. EB: What are the most important examples of Artificial Intelligence in mainstream society today? MM: There are many important examples of AI in the mainstream; some very visible, others blended in so well with other methods that the AI part is nearly invisible.
Can Management Be Replaced By AI?
There are new advancements in AI every day and people are questioning what types of jobs will be taken over by this new technology. Some people may even ask, can AI replace management and managers? To answer this question we first have to look at what it is that managers do. Managers are put in place to enforce protocols, make tough decisions and lead teams. In my opinion, I think that AI could replace bad managers.
Create a chatbot and use cognitive (or artificial intelligence) services to enhance it
This tutorial series shows how you can create a chatbot that can be deployed on two messaging applications: Facebook and Slack. In this final tutorial, I explain how you can enhance the chatbot by using IBM Watson Services. The news chatbot in this series uses developerWorks content as an example, but you can modify the content source to meet your own needs. In a previous tutorial, I described the importance of artificial intelligence (AI) in your chatbots and explained how it's hard to build your own AI--it requires not only rock stars in data science, but also a massive amount of data to train models. A small company typically does not have these kinds of resources.
Clustering For Point Pattern Data
Tran, Quang N., Vo, Ba-Ngu, Phung, Dinh, Vo, Ba-Tuong
Clustering is one of the most common unsupervised learning tasks in machine learning and data mining. Clustering algorithms have been used in a plethora of applications across several scientific fields. However, there has been limited research in the clustering of point patterns - sets or multi-sets of unordered elements - that are found in numerous applications and data sources. In this paper, we propose two approaches for clustering point patterns. The first is a non-parametric method based on novel distances for sets. The second is a model-based approach, formulated via random finite set theory, and solved by the Expectation-Maximization algorithm. Numerical experiments show that the proposed methods perform well on both simulated and real data.
Sparse Algorithm for Robust LSSVM in Primal Space
Li Chen a,b, Shuisheng Zhou a, a School of Mathematics and Statistics, Xidian University, 266 Xinglong Section, Xifeng Road, Xi'an, China b Department of Basic Science, College of Information and Business, Zhongyuan Technology University, 41 Zhongyuan Middle Road, Zhengzhou, ChinaAbstract As enjoying the closed form solution, least squares support vector machine (LSSVM) has been widely used for classification and regression problems having the comparable performance with other types of SVMs. However, LSSVM has two drawbacks: sensitive to outliers and lacking sparseness. Robust LSSVM (R-LSSVM) overcomes the first partly via nonconvex truncated loss function, but the current algorithms for R-LSSVM with the dense solution are faced with the second drawback and are inefficient for training large-scale problems. In this paper, we interpret the robustness of R-LSSVM from a re-weighted viewpoint and give a primal R-LSSVM by the representer theorem. The new model may have sparse solution if the corresponding kernel matrix has low rank. Then approximating the kernel matrix by a low-rank matrix and smoothing the loss function by entropy penalty function, we propose a convergent sparse R-LSSVM (SR-LSSVM) algorithm to achieve the sparse solution of primal R-LSSVM, which overcomes two drawbacks of LSSVM simultaneously. The proposed algorithm has lower complexity than the existing algorithms and is very efficient for training large-scale problems. Many experimental results illustrate that SR-LSSVM can achieve better or comparable performance with less training time than related algorithms, especially for training large scale problems. Keywords: Primal LSSVM, Sparse solution, Re-weighted LSSVM, Low-rank approximation, Outliers 2010 MSC: 00-01, 99-00 1. Introduction Least squares support vector machine (LSSVM) was introduced by Suykens[1] and has been a powerful learning technique for classification and regression. It has been successfully used in many real world pattern recognition problems, such as disease diagnosis[2], fault detection[3], image classification [4], partial differential equations solving[5] and visual tracking[6]. LSSVM tries to minimize least squares errors on the training samples.
Adversarial Attacks on Neural Network Policies
Huang, Sandy, Papernot, Nicolas, Goodfellow, Ian, Duan, Yan, Abbeel, Pieter
Machine learning classifiers are known to be vulnerable to inputs maliciously constructed by adversaries to force misclassification. Such adversarial examples have been extensively studied in the context of computer vision applications. In this work, we show adversarial attacks are also effective when targeting neural network policies in reinforcement learning. Specifically, we show existing adversarial example crafting techniques can be used to significantly degrade test-time performance of trained policies. Our threat model considers adversaries capable of introducing small perturbations to the raw input of the policy. We characterize the degree of vulnerability across tasks and training algorithms, for a subclass of adversarial-example attacks in white-box and black-box settings. Regardless of the learned task or training algorithm, we observe a significant drop in performance, even with small adversarial perturbations that do not interfere with human perception. Videos are available at http://rll.berkeley.edu/adversarial.
Robust Clustering for Time Series Using Spectral Densities and Functional Data Analysis
Rivera-García, Diego, García-Escudero, Luis Angel, Mayo-Iscar, Agustín, Ortega, Joaquín
In this work a robust clustering algorithm for stationary time series is proposed. The algorithm is based on the use of estimated spectral densities, which are considered as functional data, as the basic characteristic of stationary time series for clustering purposes. A robust algorithm for functional data is then applied to the set of spectral densities. Trimming techniques and restrictions on the scatter within groups reduce the effect of noise in the data and help to prevent the identification of spurious clusters. The procedure is tested in a simulation study, and is also applied to a real data set.
Efficient fetal-maternal ECG signal separation from two channel maternal abdominal ECG via diffusion-based channel selection
Li, Ruilin, Frasch, Martin G., Wu, Hau-tieng
There is a need for affordable, widely deployable maternal-fetal ECG monitors to improve maternal and fetal health during pregnancy and delivery. Based on the diffusion-based channel selection, here we present the mathematical formalism and clinical validation of an algorithm capable of accurate separation of maternal and fetal ECG from a two channel signal acquired over maternal abdomen.
Truncated Variational EM for Semi-Supervised Neural Simpletrons
Inference and learning for probabilistic generative networks is often very challenging and typically prevents scalability to as large networks as used for deep discriminative approaches. To obtain efficiently trainable, large-scale and well performing generative networks for semi-supervised learning, we here combine two recent developments: a neural network reformulation of hierarchical Poisson mixtures (Neural Simpletrons), and a novel truncated variational EM approach (TV-EM). TV-EM provides theoretical guarantees for learning in generative networks, and its application to Neural Simpletrons results in particularly compact, yet approximately optimal, modifications of learning equations. If applied to standard benchmarks, we empirically find, that learning converges in fewer EM iterations, that the complexity per EM iteration is reduced, and that final likelihood values are higher on average. For the task of classification on data sets with few labels, learning improvements result in consistently lower error rates if compared to applications without truncation. Experiments on the MNIST data set herein allow for comparison to standard and state-of-the-art models in the semi-supervised setting. Further experiments on the NIST SD19 data set show the scalability of the approach when a manifold of additional unlabeled data is available.