Overview
Pairwise Relations Discriminator for Unsupervised Raven's Progressive Matrices
Kiat, Nicholas Quek Wei, Wang, Duo, Jamnik, Mateja
Abstract reasoning is a key indicator of intelligence. The ability to hypothesise, develop abstract concepts based on concrete observations and apply this hypothesis to justify future actions has been paramount in human development. An existing line of research in outfitting intelligent machines with abstract reasoning capabilities revolves around the Raven's Progressive Matrices (RPM), a multiple-choice visual puzzle where one must identify the missing component which completes the pattern. There have been many breakthroughs in supervised approaches to solving RPM in recent years. However, since this process requires external assistance, we cannot claim that machines have achieved reasoning ability comparable to humans. Namely, when the RPM rule that relations can only exist row/column-wise is properly introduced, humans can solve RPM problems without supervision or prior experience. In this paper, we introduce a pairwise relations discriminator (PRD), a technique to develop unsupervised models with sufficient reasoning abilities to tackle an RPM problem. PRD reframes the RPM problem into a relation comparison task, which we can solve without requiring the labelling of the RPM problem. We can identify the optimal candidate by adapting the application of PRD on the RPM problem. The previous state-of-the-art approach "mcpt" in this domain achieved 28.5% accuracy on the RAVEN dataset "drt", a standard dataset for computational work on RPM. Our approach, the PRD, establishes a new state-of-the-art benchmark with an accuracy of 50.74% on the same dataset, presenting a significant improvement and a step forward in equipping machines with abstract reasoning.
Interpreting Graph Drawing with Multi-Agent Reinforcement Learning
Safarli, Ilkin, Zhou, Youjia, Wang, Bei
Applying machine learning techniques to graph drawing has become an emergent area of research in visualization. In this paper, we interpret graph drawing as a multi-agent reinforcement learning (MARL) problem. We first demonstrate that a large number of classic graph drawing algorithms, including force-directed layouts and stress majorization, can be interpreted within the framework of MARL. Using this interpretation, a node in the graph is assigned to an agent with a reward function. Via multi-agent reward maximization, we obtain an aesthetically pleasing graph layout that is comparable to the outputs of classic algorithms. The main strength of a MARL framework for graph drawing is that it not only unifies a number of classic drawing algorithms in a general formulation but also supports the creation of novel graph drawing algorithms by introducing a diverse set of reward functions.
Deep Learning for Text Attribute Transfer: A Survey
Jin, Di, Jin, Zhijing, Mihalcea, Rada
Driven by the increasingly larger deep learning models, neural language generation (NLG) has enjoyed unprecedentedly improvement and is now able to generate a diversity of human-like texts on demand, granting itself the capability of serving as a human writing assistant. Text attribute transfer is one of the most important NLG tasks, which aims to control certain attributes that people may expect the texts to possess, such as sentiment, tense, emotion, political position, etc. It has a long history in Natural Language Processing but recently gains much more attention thanks to the promising performance brought by deep learning models. In this article, we present a systematic survey on these works for neural text attribute transfer. We collect all related academic works since the first appearance in 2017. We then select, summarize, discuss, and analyze around 65 representative works in a comprehensive way. Overall, we have covered the task formulation, existing datasets and metrics for model development and evaluation, and all methods developed over the last several years. We reveal that existing methods are indeed based on a combination of several loss functions with each of which serving a certain goal. Such a unique perspective we provide could shed light on the design of new methods. We conclude our survey with a discussion on open issues that need to be resolved for better future development.
An Overview of Multi-Agent Reinforcement Learning from Game Theoretical Perspective
Following the remarkable success of the AlphaGO series, 2019 was a booming year that witnessed significant advances in multi-agent reinforcement learning (MARL) techniques. MARL corresponds to the learning problem in a multi-agent system in which multiple agents learn simultaneously. MARL is an interdisciplinary domain with a long history that includes game theory, machine learning, stochastic control, psychology, and optimisation. Although MARL has achieved considerable empirical success in solving real-world games, there is a lack of a self-contained overview in the literature that elaborates the game theoretical foundations of modern MARL methods and summarises the recent advances. In fact, the majority of existing surveys are outdated and do not fully cover the recent developments since 2010. In this work, we provide a monograph on MARL that covers both the fundamentals and the latest developments in the research frontier. The goal of our monograph is to provide a self-contained assessment of the current state-of-the-art MARL techniques from a game theoretical perspective. We expect this work to serve as a stepping stone for both new researchers who are about to enter this fast-growing domain and existing domain experts who want to obtain a panoramic view and identify new directions based on recent advances.
A Level-wise Taxonomic Perspective on Automated Machine Learning to Date and Beyond: Challenges and Opportunities
Santu, Shubhra Kanti Karmaker, Hassan, Md. Mahadi, Smith, Micah J., Xu, Lei, Zhai, ChengXiang, Veeramachaneni, Kalyan
Automated machine learning (AutoML) is essentially automating the process of applying machine learning to real-world problems. The primary goals of AutoML tools are to provide methods and processes to make Machine Learning available for non-Machine Learning experts (domain experts), to improve efficiency of Machine Learning and to accelerate research on Machine Learning. Although automation and efficiency are some of AutoML's main selling points, the process still requires a surprising level of human involvement. A number of vital steps of the machine learning pipeline, including understanding the attributes of domain-specific data, defining prediction problems, creating a suitable training data set etc. still tend to be done manually by a data scientist on an ad-hoc basis. Often, this process requires a lot of back-and-forth between the data scientist and domain experts, making the whole process more difficult and inefficient. Altogether, AutoML systems are still far from a "real automatic system". In this review article, we present a level-wise taxonomic perspective on AutoML systems to-date and beyond, i.e., we introduce a new classification system with seven levels to distinguish AutoML systems based on their level of autonomy. We first start with a discussion on how an end-to-end Machine learning pipeline actually looks like and which sub-tasks of Machine learning Pipeline has indeed been automated so far. Next, we highlight the sub-tasks which are still done manually by a data-scientist in most cases and how that limits a domain expert's access to Machine learning. Then, we introduce the novel level-based taxonomy of AutoML systems and define each level according to their scope of automation support. Finally, we provide a road-map of future research endeavor in the area of AutoML and discuss some important challenges in achieving this ambitious goal.
A Practical Guide to Graph Neural Networks
Ward, Isaac Ronald, Joyner, Jack, Lickfold, Casey, Rowe, Stash, Guo, Yulan, Bennamoun, Mohammed
NN variants have been designed to increase performance in certain problem domains; the convolutional neural network (CNN) excels in the context of image-based tasks, and the recurrent neural network (RNN) in the space of natural language processing and time series analysis. NNs have also been leveraged as components in composite DL frameworks -- they have been used as trainable generators and discriminators in generative adversarial networks (GANs), and as encoders and decoders in transformers [46]. Although they seem unrelated, the images used as inputs in computer vision, and the sentences used as inputs in natural language processing can both be represented by a single, general data structure: the graph (see Figure 1). Formally, a graph is a set of distinct vertices (representing items or entities) that are joined optionally to each other by edges (representing relationships). The learning architecture that has been designed to process said graphs is the titular graph neural network (GNN). Uniquely, the graphs fed into a GNN (during training and evaluation) do not have strict structural requirements per se; the number of vertices and edges between input graphs can change. In this way, GNNs can handle unstructured, non-Euclidean data [4], a property which makes them valuable in certain problem domains where graph data is abundant. Conversely, NN-based algorithms are typically required to operate on structured inputs with strictly defined dimensions.
From cloud to device: The future of AI and machine learning on the Edge
For a more comprehensive survey, read our full paper on this topic. We are surrounded by smart devices: from mobile phones and watches to glasses, jewelry, and even clothes. But while these devices are small and powerful, they are merely the tip of a computing iceberg that starts at your fingertips and ends in giant data and compute centers across the world. Data is transmitted from devices to the cloud where it is used to train models that are then transmitted back to be deployed back on the device. Unless used for learning simple concepts like wake words or recognizing your face to unlock your phone, machine learning is computationally expensive and data has no choice but to travel these thousands of miles before it can be turned into useful information.
The Mathematical Foundations of Manifold Learning
This is an edited version of my undergraduate thesis, submitted to the Harvard Mathematics Department in May 2020. It differs from the original thesis in one major respect, namely that this version omits the proofs of a number of theorems that are readily-available in other expositions. Whereas the original version reproduced these proofs in full, this version simply contains references to these proofs in other works. This thesis is built upon an extensive body of prior work in learning theory, graph theory, differential geometry, and manifold learning. In particular, I would like to thank Professors Lorenzo Rosasco and Tomaso Poggio for their lectures on statistical learning theory, Professor Daniel Spielman for his notes on spectral graph theory, Professor Yaiza Canzani for her notes on analysis on manifolds, and Professor Mikhail Belkin for his work on manifold learning. Finally, I wish to thank those people without whom I could never have written this thesis: my family, friends, and wonderful advisor Professor Arjun Manrai. Unlike the manifolds discussed herein, their support was truly boundless. I hope you enjoy and learn something from this thesis! If you have comments, corrections, or would like to contact me for anything else, feel free to email me.
Artificial intelligence (AI)-aided disease prediction
In this review article the authors Chenxi Liu, Dian Jiao and Zhe Liu, from Tianjin University, Tianjin, China consider artificial intelligence (AI) aided disease prediction. Artificial intelligence (AI) is widely used in clinical medicine and is increasingly applied to the fields of AI-aided image analysis, AI-aided lesion determination and AI-assisted healthcare management. In this article the authors discuss the emerging applications of AI-related medicine and AI-assisted visualized medicine, including novel diagnostic approaches, metadata analytical methods, and versatile AI-aided treatment applications in preclinical and clinical uses. BIO Integration is fully open access journal which will allow for the rapid dissemination of multidisciplinary views driving the progress of modern medicine. As part of its mandate to help bring interesting work and knowledge from around the world to a wider audience, BIOI will actively support authors through open access publishing and through waiving author fees in its first years.
Domain adaptation under structural causal models
Domain adaptation (DA) arises as an important problem in statistical machine learning when the source data used to train a model is different from the target data used to test the model. Recent advances in DA have mainly been application-driven and have largely relied on the idea of a common subspace for source and target data. To understand the empirical successes and failures of DA methods, we propose a theoretical framework via structural causal models that enables analysis and comparison of the prediction performance of DA methods. This framework also allows us to itemize the assumptions needed for the DA methods to have a low target error. Additionally, with insights from our theory, we propose a new DA method called CIRM that outperforms existing DA methods when both the covariates and label distributions are perturbed in the target data. We complement the theoretical analysis with extensive simulations to show the necessity of the devised assumptions. Reproducible synthetic and real data experiments are also provided to illustrate the strengths and weaknesses of DA methods when parts of the assumptions of our theory are violated.