Statistical Learning
Information Theoretic Meta Learning with Gaussian Processes
Titsias, Michalis K., Nikoloutsopoulos, Sotirios, Galashov, Alexandre
We formulate meta learning using information theoretic concepts such as mutual information and the information bottleneck. The idea is to learn a stochastic representation or encoding of the task description, given by a training or support set, that is highly informative about predicting the validation set. By making use of variational approximations to the mutual information, we derive a general and tractable framework for meta learning. We particularly develop new memorybased meta learning algorithms based on Gaussian processes and derive extensions that combine memory and gradient-based meta learning. We demonstrate our method on few-shot regression and classification by using standard benchmarks such as Omniglot, mini-Imagenet and Augmented Omniglot. Such systems require training deep neural networks from a set of tasks drawn from a common distribution, where each task is described by a small amount of experience, typically divided into a training or support set and a validation set. By sharing information across tasks the neural network can learn to rapidly adapt to new tasks and generalize from few examples at test time. Several few-shot learning algorithms use memory-based (Vinyals et al., 2016; Ravi & Larochelle, 2017) or gradient-based procedures (Finn et al., 2017; Nichol et al., 2018), with the gradient-based model agnostic meta learning algorithm (MAML) by Finn et al. (2017) being very influential in the literature. Despite the success of specific schemes, one fundamental issue in meta learning is concerned with deriving unified principles that can allow to relate different approaches and invent new schemes.
Learning Unbiased Representations via R\'enyi Minimization
Grari, Vincent, Hajouji, Oualid El, Lamprier, Sylvain, Detyniecki, Marcin
In recent years, significant work has been done to include fairness constraints in the training objective of machine learning algorithms. Many state-of the-art algorithms tackle this challenge by learning a fair representation which captures all the relevant information to predict the output Y while not containing any information about a sensitive attribute S. In this paper, we propose an adversarial algorithm to learn unbiased representations via the Hirschfeld-Gebelein-Renyi (HGR) maximal correlation coefficient. We leverage recent work which has been done to estimate this coefficient by learning deep neural network transformations and use it as a minmax game to penalize the intrinsic bias in a multi dimensional latent representation. Compared to other dependence measures, the HGR coefficient captures more information about the non-linear dependencies with the sensitive variable, making the algorithm more efficient in mitigating bias in the representation. We empirically evaluate and compare our approach and demonstrate significant improvements over existing works in the field.
Intro to Machine learning
It has been long understood that learning is a key element of intelligence. This holds both for natural intelligence - we all get smarter by learning and artificial intelligence. The roots of machine learning are in statistics, which can also be thought of as the art of extracting knowledge from data. Especially methods such as linear regression and Bayesian statistics, which are both already more than two centuries old (!), are even today at the heart of machine learning. For more examples and a brief history, see the timeline of machine learning (Wikipedia). Examples include predicting the number of people who will click a Google ad based on the ad content and data about the user's prior online behavior, predicting the number of traffic accidents based on road conditions and speed limit, or predicting the selling price of real estate based on its location, size, and condition.
Machine Learning Regression Masterclass in Python
Artificial Intelligence (AI) revolution is here! The technology is progressing at a massive scale and is being widely adopted in the Healthcare, defense, banking, gaming, transportation and robotics industries. Machine Learning is a subfield of Artificial Intelligence that enables machines to improve at a given task with experience. Machine Learning is an extremely hot topic; the demand for experienced machine learning engineers and data scientists has been steadily growing in the past 5 years. According to a report released by Research and Markets, the global AI and machine learning technology sectors are expected to grow from $1.4B to $8.8B by 2022 and it is predicted that AI tech sector will create around 2.3 million jobs by 2020.
Data Analytics Learning Path - Gift Course
This online tutorial teaches you complete MS Excel from the scratch covering all the essential topics such as Pivots, Macros and Analytics. Learning SQL for Data Analytics is now easy with this online tutorial. Enroll today to master SQL from the beginning by learning SQL commands and tools. Get started with this tutorial to master ML basics Machine Learning Basics: Classification models in Python Course. Get an insights into Machine Learning classification models using Python with this online tutorial.
How Does Image Classification Work?
How can your phone determine what an object is just by taking a photo of it? How do social media websites automatically tag people in photos? This is accomplished through AI-powered image recognition and classification. The recognition and classification of images is what enables many of the most impressive accomplishments of artificial intelligence. Yet how do computers learn to detect and classify images?
Active Learning++: Incorporating Annotator's Rationale using Local Model Explanation
Ghai, Bhavya, Liao, Q. Vera, Zhang, Yunfeng, Mueller, Klaus
We propose a new active learning (AL) framework, Active Learning++, which can utilize an annotator's labels as well as its rationale. Annotators can provide their rationale for choosing a label by ranking input features based on their importance for a given query. To incorporate this additional input, we modified the disagreement measure for a bagging-based Query by Committee (QBC) sampling strategy. Instead of weighing all committee models equally to select the next instance, we assign higher weight to the committee model with higher agreement with the annotator's ranking. Specifically, we generated a feature importance-based local explanation for each committee model. The similarity score between feature rankings provided by the annotator and the local model explanation is used to assign a weight to each corresponding committee model. This approach is applicable to any kind of ML model using model-agnostic techniques to generate local explanation such as LIME. With a simulation study, we show that our framework significantly outperforms a QBC based vanilla AL framework.
Hybrid Differentially Private Federated Learning on Vertically Partitioned Data
Wang, Chang, Liang, Jian, Huang, Mingkai, Bai, Bing, Bai, Kun, Li, Hao
We present HDP-VFL, the first hybrid differentially private (DP) framework for vertical federated learning (VFL) to demonstrate that it is possible to jointly learn a generalized linear model (GLM) from vertically partitioned data with only a negligible cost, w.r.t. training time, accuracy, etc., comparing to idealized non-private VFL. Our work builds on the recent advances in VFL-based collaborative training among different organizations which rely on protocols like Homomorphic Encryption (HE) and Secure Multi-Party Computation (MPC) to secure computation and training. In particular, we analyze how VFL's intermediate result (IR) can leak private information of the training data during communication and design a DP-based privacy-preserving algorithm to ensure the data confidentiality of VFL participants. We mathematically prove that our algorithm not only provides utility guarantees for VFL, but also offers multi-level privacy, i.e. DP w.r.t. IR and joint differential privacy (JDP) w.r.t. model weights. Experimental results demonstrate that our work, under adequate privacy budgets, is quantitatively and qualitatively similar to GLMs, learned in idealized non-private VFL setting, rather than the increased cost in memory and processing time in most prior works based on HE or MPC. Our codes will be released if this paper is accepted.
Fairness-Aware Online Personalization
Lal, G Roshan, Geyik, Sahin Cem, Kenthapadi, Krishnaram
Decision making in crucial applications such as lending, hiring, and college admissions has witnessed increasing use of algorithmic models and techniques as a result of a confluence of factors such as ubiquitous connectivity, ability to collect, aggregate, and process large amounts of fine-grained data using cloud computing, and ease of access to applying sophisticated machine learning models. Quite often, such applications are powered by search and recommendation systems, which in turn make use of personalized ranking algorithms. At the same time, there is increasing awareness about the ethical and legal challenges posed by the use of such data-driven systems. Researchers and practitioners from different disciplines have recently highlighted the potential for such systems to discriminate against certain population groups, due to biases in the datasets utilized for learning their underlying recommendation models. We present a study of fairness in online personalization settings involving the ranking of individuals. Starting from a fair warm-start machine-learned model, we first demonstrate that online personalization can cause the model to learn to act in an unfair manner if the user is biased in his/her responses. For this purpose, we construct a stylized model for generating training data with potentially biased features as well as potentially biased labels and quantify the extent of bias that is learned by the model when the user responds in a biased manner as in many real-world scenarios. We then formulate the problem of learning personalized models under fairness constraints and present a regularization based approach for mitigating biases in machine learning. We demonstrate the efficacy of our approach through extensive simulations with different parameter settings. Code: https://github.com/groshanlal/Fairness-Aware-Online-Personalization
Learning Inter- and Intra-manifolds for Matrix Factorization-based Multi-Aspect Data Clustering
Abstract--Clustering on the data with multiple aspects, such as multi-view or multi-type relational data, has become popular in recent years due to their wide applicability. The approach using manifold learning with the Nonnegative Matrix Factorization (NMF) framework, that learns the accurate low-rank representation of the multidimensional data, has shown effectiveness. We propose to include the inter-manifold in the NMF framework, utilizing the distance information of data points of different data types (or views) to learn the diverse manifold for data clustering. Empirical analysis reveals that the proposed method can find partial representations of various interrelated types and select useful features during clustering. Results on several datasets demonstrate that the proposed method outperforms the state-of-the-art multi-aspect data clustering methods in both accuracy and efficiency. This can be (1) multi-view data where samples For instance, in Figure 1.a, three intra-type relationship are represented by multiple views; or (2) multi-type matrices will store intra-similarities between Webpages, relational data (MTRD) where samples are represented by between Terms and between Hyperlinks, and three interrelationships different data types and their inherent relationships.