Bayesian Learning
Towards Continual Reinforcement Learning: A Review and Perspectives
Khetarpal, Khimya | Riemer, Matthew (a:1:{s:5:"en_US";s:42:"IBM Research, Mila, University of Montreal";}) | Rish, Irina | Precup, Doina
In this article, we aim to provide a literature review of different formulations and approaches to continual reinforcement learning (RL), also known as lifelong or non-stationary RL. We begin by discussing our perspective on why RL is a natural fit for studying continual learning. We then provide a taxonomy of different continual RL formulations by mathematically characterizing two key properties of non-stationarity, namely, the scope and driver non-stationarity. This offers a unified view of various formulations. Next, we review and present a taxonomy of continual RL approaches. We go on to discuss evaluation of continual RL agents, providing an overview of benchmarks used in the literature and important metrics for understanding agent performance. Finally, we highlight open problems and challenges in bridging the gap between the current state of continual RL and findings in neuroscience. While still in its early days, the study of continual RL has the promise to develop better incremental reinforcement learners that can function in increasingly realistic applications where non-stationarity plays a vital role. These include applications such as those in the fields of healthcare, education, logistics, and robotics.
Intelligent Autonomous Systems Engineer
My client, a world leader in the defence sector, requires an Machine Learning Algorithm Developer to join them in Bristol and work as part of a team on the development and evaluation of state-of-the-art algorithms for the guidance, control and navigation of their missile and weapon systems.
The Machine Learning Algorithm Developer will work within a team of Intelligent Systems, Autonomous Systems and Command and Control Engineers to develop and evaluate state-of-the-art algorithms across a range of domains from on-board, autonomous decision making to off-board algorithms. The work will involve the research, development, test, evaluation and implementation of algorithms that integrate into complex guided weapon systems products.
Algorithms are central to the design of sophisticated guided weapon systems products. These algorithms are developed throughout the lifecycle of the product and include research studies to investigate algorithms for future developments.
Machine Learning Algorithm Developers are involved in the lifecycle of projects, playing a pivotal role in our product developments including:
Technical development of specific algorithms or studies for key programmes.Feasibility studies, algorithm design and trade-off studies, preparing trials, trials analysis and reporting, defining architecture, validating algorithms and models.Technical assessments and investigations into a full range of issues and problems and prepare and develop solutions either solely or as a member of a project team.Engaging with the algorithm users, understanding and responding to their needs and ensure that the algorithms are fit for purpose.
You will gain exposure to a range of other related subject areas e.g. Simulation and Modelling, Software, Hardware-in-the Loop, Systems Design & Validation, Seekers & Sensors, Datalinks and Technical Quality and will be exposed to cutting-edge technological innovations, playing a meaningful role through the development of complex weapon systems.
To be considered for this role, applicants will ideally have completed (or be soon to complete) a PhD level in a related area with a good degree in a subject with strong mathematical content and programming skills e.g. Engineering, Mathematics, Physics, Computer Science, Information Engineering.
You will have previous experience in the development and practical application of algorithms, with experience in some of the following:
Robotics, data fusion, tracking/estimation, pattern discovery & recognition, statistical inference, optimisation and machine/deep learning algorithms along with real-time implementation, and/or validation & verification.
You will also have experience in some of the following: Matlab, Simulink, Stateflow, Python including PyTorch, TensorFlow, Open AI-Gym/Universe, Model Based Design.
Specific knowledge or experience in any of these areas would also be ideal:
Robotics, guidance and autonomous decision making, e.g. Routing and motion/trajectory planning, optimisation, co-ordinated guidance and control, decision theory, MDPs/POMDPs, specialist systems, game theory, decision support systems, multi-agent systemsData fusion and state estimation/tracking algorithms e.g. Kalman Filtering, multiple-model tracking methods, particle filters, grid-based estimation methods, Multi-Object-Multi-Sensor Fusion, data-association, random finite sets, Bayesian belief networks, Dempster-Shafer theory of evidenceMachine Learning for regression and pattern recognition/discovery problems e.g. Gaussian processes, latent variable methods, support vector machines, probabilistic/statistical models, neural networks, Bayesian inference, random-forests, novelty detection, clusteringDeep Learning e.g. Deep reinforcement learning, Monte-Carlo tree search, deep regression/classification, deep embeddings, recurrent Networks, natural language processingComputer Vision algorithms e.g. Structure from motion, image Based navigation, SLAM, pose estimation/recovery
Machine Learning Algorithm Developer
Bristol
Salary £35-50k plus benefits DOE
Key Skills: Intelligent Systems Engineer, Intelligent Autonomous Systems Engineer, IAS Engineer, PhD, Mathematics, Algorithms, Programming, Robotics, Autonomous Decision Making, Machine Learning, Deep Learning, Data Fusion, Pattern Discovery, Pattern Recognition, Computer Vision, Machine Vision, Matlab, Simulink, Stateflow, Python, PyTorch
Due to the nature of work undertaken at our client's site, incumbents of these positions are required to meet special nationality rules and therefore these vacancies are only open to sole British Citizens. Applicants who meet these criteria will also be required to undergo security clearance vetting, if not already security cleared to a minimum SC level.
Electus Recruitment Solutions provides specialist engineering and technical recruitment solutions to a number of high technology industries. We thank you for your interest in this vacancy. If you don't hear from us within 7 working days please presume your application has been unsuccessful on this occasion. You are of course free to resubmit your CV/details in the future and we shall assess your suitability at that time.
This role is a PERMANENT position
The Inverse of Exact Renormalization Group Flows as Statistical Inference
Berman, David S., Klinger, Marc S.
We build on the view of the Exact Renormalization Group (ERG) as an instantiation of Optimal Transport described by a functional convection-diffusion equation. We provide a new information theoretic perspective for understanding the ERG through the intermediary of Bayesian Statistical Inference. This connection is facilitated by the Dynamical Bayesian Inference scheme, which encodes Bayesian inference in the form of a one parameter family of probability distributions solving an integro-differential equation derived from Bayes' law. In this note, we demonstrate how the Dynamical Bayesian Inference equation is, itself, equivalent to a diffusion equation which we dub Bayesian Diffusion. Identifying the features that define Bayesian Diffusion, and mapping them onto the features that define the ERG, we obtain a dictionary outlining how renormalization can be understood as the inverse of statistical inference.
Debiased machine learning for estimating the causal effect of urban traffic on pedestrian crossing behaviour
Before the transition of AVs to urban roads and subsequently unprecedented changes in traffic conditions, evaluation of transportation policies and futuristic road design related to pedestrian crossing behavior is of vital importance. Recent studies analyzed the non-causal impact of various variables on pedestrian waiting time in the presence of AVs. However, we mainly investigate the causal effect of traffic density on pedestrian waiting time. We develop a Double/Debiased Machine Learning (DML) model in which the impact of confounders variable influencing both a policy and an outcome of interest is addressed, resulting in unbiased policy evaluation. Furthermore, we try to analyze the effect of traffic density by developing a copula-based joint model of two main components of pedestrian crossing behavior, pedestrian stress level and waiting time. The copula approach has been widely used in the literature, for addressing self-selection problems, which can be classified as a causality analysis in travel behavior modeling. The results obtained from copula approach and DML are compared based on the effect of traffic density. In DML model structure, the standard error term of density parameter is lower than copula approach and the confidence interval is considerably more reliable. In addition, despite the similar sign of effect, the copula approach estimates the effect of traffic density lower than DML, due to the spurious effect of confounders. In short, the DML model structure can flexibly adjust the impact of confounders by using machine learning algorithms and is more reliable for planning future policies.
Truncated Matrix Power Iteration for Differentiable DAG Learning
Zhang, Zhen, Ng, Ignavier, Gong, Dong, Liu, Yuhang, Abbasnejad, Ehsan M, Gong, Mingming, Zhang, Kun, Shi, Javen Qinfeng
Recovering underlying Directed Acyclic Graph (DAG) structures from observational data is highly challenging due to the combinatorial nature of the DAG-constrained optimization problem. Recently, DAG learning has been cast as a continuous optimization problem by characterizing the DAG constraint as a smooth equality one, generally based on polynomials over adjacency matrices. Existing methods place very small coefficients on high-order polynomial terms for stabilization, since they argue that large coefficients on the higher-order terms are harmful due to numeric exploding. On the contrary, we discover that large coefficients on higher-order terms are beneficial for DAG learning, when the spectral radiuses of the adjacency matrices are small, and that larger coefficients for higher-order terms can approximate the DAG constraints much better than the small counterparts. Based on this, we propose a novel DAG learning method with efficient truncated matrix power iteration to approximate geometric series based DAG constraints. Empirically, our DAG learning method outperforms the previous state-of-the-arts in various settings, often by a factor of $3$ or more in terms of structural Hamming distance.
Formalising the Robustness of Counterfactual Explanations for Neural Networks
Jiang, Junqi, Leofante, Francesco, Rago, Antonio, Toni, Francesca
The use of counterfactual explanations (CFXs) is an increasingly popular explanation strategy for machine learning models. However, recent studies have shown that these explanations may not be robust to changes in the underlying model (e.g., following retraining), which raises questions about their reliability in real-world applications. Existing attempts towards solving this problem are heuristic, and the robustness to model changes of the resulting CFXs is evaluated with only a small number of retrained models, failing to provide exhaustive guarantees. To remedy this, we propose {\Delta}-robustness, the first notion to formally and deterministically assess the robustness (to model changes) of CFXs for neural networks. We introduce an abstraction framework based on interval neural networks to verify the {\Delta}-robustness of CFXs against a possibly infinite set of changes to the model parameters, i.e., weights and biases. We then demonstrate the utility of this approach in two distinct ways. First, we analyse the {\Delta}-robustness of a number of CFX generation methods from the literature and show that they unanimously host significant deficiencies in this regard. Second, we demonstrate how embedding {\Delta}-robustness within existing methods can provide CFXs which are provably robust.
Combinatorial Causal Bandits
In combinatorial causal bandits (CCB), the learning agent chooses at most $K$ variables in each round to intervene, collects feedback from the observed variables, with the goal of minimizing expected regret on the target variable $Y$. We study under the context of binary generalized linear models (BGLMs) with a succinct parametric representation of the causal models. We present the algorithm BGLM-OFU for Markovian BGLMs (i.e. no hidden variables) based on the maximum likelihood estimation method, and show that it achieves $O(\sqrt{T}\log T)$ regret, where $T$ is the time horizon. For the special case of linear models with hidden variables, we apply causal inference techniques such as the do-calculus to convert the original model into a Markovian model, and then show that our BGLM-OFU algorithm and another algorithm based on the linear regression both solve such linear models with hidden variables. Our novelty includes (a) considering the combinatorial intervention action space and the general causal models including ones with hidden variables, (b) integrating and adapting techniques from diverse studies such as generalized linear bandits and online influence maximization, and (c) avoiding unrealistic assumptions (such as knowing the joint distribution of the parents of $Y$ under all interventions) and regret factors exponential to causal graph size in prior studies.
7 Best Certifications for Machine Learning You Must Know in 2023
Are you looking for the Best Certifications for Machine Learning? If yes, this article is for you. In this article, I listed the 7 Best Certifications for Machine Learning. So, give a few minutes to this article and find the Best Certifications for Machine Learning for you. Now without further ado, let's get started- In this Nanodegree Program, there are 4 courses and 5 Projects.
Generative Networks for Precision Enthusiasts
Butter, Anja, Heimel, Theo, Hummerich, Sander, Krebs, Tobias, Plehn, Tilman, Rousselot, Armand, Vent, Sophia
Generative networks are opening new avenues in fast event generation for the LHC. We show how generative flow networks can reach percent-level precision for kinematic distributions, how they can be trained jointly with a discriminator, and how this discriminator improves the generation. Our joint training relies on a novel coupling of the two networks which does not require a Nash equilibrium. We then estimate the generation uncertainties through a Bayesian network setup and through conditional data augmentation, while the discriminator ensures that there are no systematic inconsistencies compared to the training data.
Multimodal Learning for Multi-Omics: A Survey
Tabakhi, Sina, Suvon, Mohammod Naimul Islam, Ahadian, Pegah, Lu, Haiping
With advanced imaging, sequencing, and profiling technologies, multiple omics data become increasingly available and hold promises for many healthcare applications such as cancer diagnosis and treatment. Multimodal learning for integrative multi-omics analysis can help researchers and practitioners gain deep insights into human diseases and improve clinical decisions. However, several challenges are hindering the development in this area, including the availability of easily accessible open-source tools. This survey aims to provide an up-to-date overview of the data challenges, fusion approaches, datasets, and software tools from several new perspectives. We identify and investigate various omics data challenges that can help us understand the field better. We categorize fusion approaches comprehensively to cover existing methods in this area. We collect existing open-source tools to facilitate their broader utilization and development. We explore a broad range of omics data modalities and a list of accessible datasets. Finally, we summarize future directions that can potentially address existing gaps and answer the pressing need to advance multimodal learning for multi-omics data analysis.