Genre
A Brief Overview of Outlier Detection Techniques – Towards Data Science – Medium
Outliers are extreme values that deviate from other observations on data, they may indicate a variability in a measurement, experimental errors or a novelty. In other words, an outlier is an observation that diverges from an overall pattern on a sample. Outliers can be of two kinds: univariate and multivariate. Univariate outliers can be found when looking at a distribution of values in a single feature space. Multivariate outliers can be found in a n-dimensional space (of n-features).
Booking.com Buys Evature for Its Chatbot Talent
Booking.com acquired a tiny software company called Evature, which is based in Tel Aviv and offers natural language and chatbot-related technologies for hotels, airlines, travel agencies, and airports. The companies did not disclose the terms of the deal, but only a small sum was likely involved. The company is said to have raised $5 million in funding, and the deal has all the appearances of being an acqui-hire. A Booking.com spokesperson said that the company acquired Evature "to support research-and-development efforts generally, but also specifically in the area of deep learning and artificial intelligence. All of this is a part of Booking's ongoing dedication to testing new areas of technology innovation."
Four deep learning trends from ACL 2017
This is the second of a two-part post in which I describe four broad research trends that I observed at ACL 2017. In Part One I explored the shifting assumptions we make about language, both at the sentence and the word level, and how these shifts are prompting both a comeback of linguistic structure and a re-evaluation of word embeddings. In this part, I will discuss two more very inter-related themes: interpretability and attention. Throughout, green links are ordinary hyperlinks, while blue links lead to papers, and offer bibliographic information when you hover over them (not supported on mobile). I've been thinking about interpretability a lot recently, and I'm not alone – among deep learning practitioners, the dreaded "black box" quality of neural networks makes them notoriously hard to control, hard to debug and thus hard to develop.
Alzheimer's Spotted Early through Machine-Learning Technique GEN
Case Western Reserve University scientists have developed a new machine learning program that looks like it may be able to diagnose Alzheimer's disease before symptoms begin to interfere with day-to-day activities. While there is no cure for Alzheimer's, a number of drugs can delay or prevent symptoms from worsening for up to five years or more, Early diagnosis and treatment--the goal of the new computer-based program--is key to allowing those with the disease to remain independent longer, according to the researchers. In two successive stages, the algorithm selects the most pertinent to predict who has Alzheimer's. The team published its study ("Cascaded Multi-view Canonical Correlation (CaMCCo) for Early Diagnosis of Alzheimer's Disease via Fusion of Clinical, Imaging and Omic Features") in Scientific Reports. "The introduction of mild cognitive impairment (MCI) as a diagnostic category adds to the challenges of diagnosing Alzheimer's Disease (AD). No single marker has been proven to accurately categorize patients into their respective diagnostic groups," write the investigators.
Random Forests of Interaction Trees for Estimating Individualized Treatment Effects in Randomized Trials
Su, Xiaogang, Peña, Annette T., Liu, Lei, Levine, Richard A.
Assessing heterogeneous treatment effects has become a growing interest in advancing precision medicine. Individualized treatment effects (ITE) play a critical role in such an endeavor. Concerning experimental data collected from randomized trials, we put forward a method, termed random forests of interaction trees (RFIT), for estimating ITE on the basis of interaction trees (Su et al., 2009). To this end, we first propose a smooth sigmoid surrogate (SSS) method, as an alternative to greedy search, to speed up tree construction. RFIT outperforms the traditional `separate regression' approach in estimating ITE. Furthermore, standard errors for the estimated ITE via RFIT can be obtained with the infinitesimal jackknife method. We assess and illustrate the use of RFIT via both simulation and the analysis of data from an acupuncture headache trial.
Informed Non-convex Robust Principal Component Analysis with Features
Xue, Niannan, Deng, Jiankang, Panagakis, Yannis, Zafeiriou, Stefanos
Many machine learning and artificial intelligence tasks involve the separation of a data matrix into a low-rank structure and a sparse part capturing different information. Robust principal component analysis (RPCA) Candes et al. [2011], Chandrasekaran et al. [2011] is a popular framework that logically characterizes this matrix separation problem. Nevertheless, prior side information, oftentimes in the form of features, may also be present in practice. For instance, features are available for the following tasks: - Collaborative filtering: apart from ratings of an item by other users, the profile of the user and the description of the item can also be exploited in making recommendations Chiang et al. [2015]; - Relationship prediction: user behaviours and message exchanges can assist in finding missing links on social media networks Xu et al. [2013]; - Person-specific facial deformable models: an orthonormal subspace learnt from manually annotated data captured in-the-wild, when fed into an im-1 age congealing procedure, can help produce more correct fittings Sagonas et al. [2014]. It is thus reasonable to investigate how propitious it is for RPCA to exploit the available features. Indeed, recent results Liu et al. [2017] indicate that features are not redundant at all. In the setting of multiple subspaces, RPCA degrades as the number of subspaces grows because of the increased row-coherence. On the other hand, the use of feature dictionaries allows accurate low-rank recovery by removing the dependency on row-coherence.
Interpretable Graph-Based Semi-Supervised Learning via Flows
Rustamov, Raif M., Klosowski, James T.
In this paper, we consider the interpretability of the foundational Laplacian-based semi-supervised learning approaches on graphs. We introduce a novel flow-based learning framework that subsumes the foundational approaches and additionally provides a detailed, transparent, and easily understood expression of the learning process in terms of graph flows. As a result, one can visualize and interactively explore the precise subgraph along which the information from labeled nodes flows to an unlabeled node of interest. Surprisingly, the proposed framework avoids trading accuracy for interpretability, but in fact leads to improved prediction accuracy, which is supported both by theoretical considerations and empirical results. The flow-based framework guarantees the maximum principle by construction and can handle directed graphs in an out-of-the-box manner.