Inductive Learning
Shuffle and Learn: Unsupervised Learning using Temporal Order Verification
Misra, Ishan, Zitnick, C. Lawrence, Hebert, Martial
In this paper, we present an approach for learning a visual representation from the raw spatiotemporal signals in videos. Our representation is learned without supervision from semantic labels. We formulate our method as an unsupervised sequential verification task, i.e., we determine whether a sequence of frames from a video is in the correct temporal order. With this simple task and no semantic labels, we learn a powerful visual representation using a Convolutional Neural Network (CNN). The representation contains complementary information to that learned from supervised image datasets like ImageNet. Qualitative results show that our method captures information that is temporally varying, such as human pose. When used as pre-training for action recognition, our method gives significant gains over learning without external data on benchmark datasets like UCF101 and HMDB51. To demonstrate its sensitivity to human pose, we show results for pose estimation on the FLIC and MPII datasets that are competitive, or better than approaches using significantly more supervision. Our method can be combined with supervised representations to provide an additional boost in accuracy.
Interactive Learning from Multiple Noisy Labels
Vembu, Shankar, Zilles, Sandra
We consider binary classification problems in the presence of a teacher, who acts as an intermediary to provide a learning algorithm with meaningful, well-chosen examples. This setting is also known as curriculum learning [1, 2, 3] or self-paced learning [4, 5, 6] in the literature. Existing practical methods [4, 7] that employ such a teacher operate by providing the learning algorithm with easy examples first and then progressively moving on to more difficult examples. Such a strategy is known to improve the generalization ability of the learning algorithm and/or alleviate local minima problems while optimizing non-convex objective functions. In this work, we propose a new method to quantify the notion of easiness of a training example.
Untangling AdaBoost-based Cost-Sensitive Classification. Part I: Theoretical Perspective
Landesa-Vázquez, Iago, Alba-Castro, José Luis
Boosting algorithms have been widely used to tackle a plethora of problems. In the last few years, a lot of approaches have been proposed to provide standard AdaBoost with cost-sensitive capabilities, each with a different focus. However, for the researcher, these algorithms shape a tangled set with diffuse differences and properties, lacking a unifying analysis to jointly compare, classify, evaluate and discuss those approaches on a common basis. In this series of two papers we aim to revisit the various proposals, both from theoretical (Part I) and practical (Part II) perspectives, in order to analyze their specific properties and behavior, with the final goal of identifying the algorithm providing the best and soundest results.
Robot takes on the role of scheduling nurse in a busy hospital labor ward
We hear plenty of stories about AI being used in medicine, whether it's discovering new drugs or helping diagnose diseases based on symptoms which may be imperceptible to even expert physicians. One area we've not previously heard about machines working in, however, is in the role of "resource nurse" in a hospital. A nurse in this position in the labor and delivery ward is responsible for making decisions about the rooms patients should be assigned to, or which physician should perform a C-section. That's work that researchers in MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL) attempted to replicate recently -- with a Nao robot trained to learn how these scheduling choices are made and make similar decisions on its own. "What we were able to show is that a system with only a few dozen training examples from people performing a task very well was able to make decisions which appear to be reasonable," Professor Julie Shah, of of the authors of the study, told Digital Trends.
Minimum Description Length Principle in Supervised Learning with Application to Lasso
Kawakita, Masanori, Takeuchi, Jun'ichi
The minimum description length (MDL) principle in supervised learning is studied. One of the most important theories for the MDL principle is Barron and Cover's theory (BC theory), which gives a mathematical justification of the MDL principle. The original BC theory, however, can be applied to supervised learning only approximately and limitedly. Though Barron et al. recently succeeded in removing a similar approximation in case of unsupervised learning, their idea cannot be essentially applied to supervised learning in general. To overcome this issue, an extension of BC theory to supervised learning is proposed. The derived risk bound has several advantages inherited from the original BC theory. First, the risk bound holds for finite sample size. Second, it requires remarkably few assumptions. Third, the risk bound has a form of redundancy of the two-stage code for the MDL procedure. Hence, the proposed extension gives a mathematical justification of the MDL principle to supervised learning like the original BC theory. As an important example of application, new risk and (probabilistic) regret bounds of lasso with random design are derived. The derived risk bound holds for any finite sample size $n$ and feature number $p$ even if $n\ll p$ without boundedness of features in contrast to the past work. Behavior of the regret bound is investigated by numerical simulations. We believe that this is the first extension of BC theory to general supervised learning with random design without approximation.
A Gentle Guide to Machine Learning MonkeyLearn Blog
Machine Learning is a subfield within Artificial Intelligence that builds algorithms that allow computers to learn to perform tasks from data instead of being explicitly programmed. We can make machines learn to do things! The first time I heard that, it blew my mind. That means that we can program computers to learn things by themselves! The ability of learning is one of the most important aspects of intelligence. Translating that power to machines, sounds like a huge step towards making them more intelligent. And in fact, Machine Learning is the area that is making most of the progress in Artificial Intelligence today; being a trendy topic right now and pushing the possibility to have more intelligent machines.
Overfitting In Machine Learning (IT Best Kept Secret Is Optimization)
Do you get what overfitting means in machine learning? If you don't, then you better learn about it if you want to use or leverage machine learning. Because overfitting can ruin the effectiveness of machine learning. I wrote this blog because I found existing explanations of overfitting to be too technical. I hope this one is more consumable by non specialists. Machine learning involves a fairly complex workflow, see Machine Learning Algorithm!
Overfitting In Machine Learning (IT Best Kept Secret Is Optimization)
Do you get what overfitting means in machine learning? If you don't, then you better learn about it if you want to use or leverage machine learning. Because overfitting can ruin the effectiveness of machine learning. I wrote this blog because I found existing explanations of overfitting to be too technical. I hope this one is more consumable by non specialists. Machine learning involves a fairly complex workflow, see Machine Learning Algorithm!
Roger Federer ties a Wimbledon record set by Jimmy Connors
Looking in fine form after two days of rest, Roger Federer equaled Jimmy Connors' Open-era record by reaching his 14th Wimbledon quarterfinal and added to his own mark by making it at least that far at a Grand Slam tournament for the 48th time. Federer, a seven-time champion at the All England Club, has not dropped a set in the tournament through four matches after beating unseeded American Steve Johnson 6-2, 6-3, 7-5 at Centre Court on Monday. Johnson was making his debut in the fourth round of a major. The No. 3-seeded Federer hadn't played since Friday, when he was the only man to finish a third-round match. He next faces No. 9 Marin Cilic, the 2014 US Open champion, who advanced when Kei Nishikori retired from their fourth-round match.
A small and easy introduction to Transductive Learning
Input: a) A set of labelled examples where every is the input vector, and is the corresponding output label. Output: The set of expected labels for all instances in . There are two ways (or rather, two philosophies) you could use, to solve this problem. Induction, in the context of learning, is the attempted discovery of rules/generalizations based on analysis of collected data. 'Attempted discovery' is the key term here – the generalizations are not facts, but approximations based on evidence you have gathered.