Oceania
Active SLAM: A Review On Last Decade
Ahmed, Muhammad Farhan, Masood, Khayyam, Fremont, Vincent, Fantoni, Isabelle
This article presents a comprehensive review of the Active Simultaneous Localization and Mapping (A-SLAM) research conducted over the past decade. It explores the formulation, applications, and methodologies employed in A-SLAM, particularly in trajectory generation and control-action selection, drawing on concepts from Information Theory (IT) and the Theory of Optimal Experimental Design (TOED). This review includes both qualitative and quantitative analyses of various approaches, deployment scenarios, configurations, path-planning methods, and utility functions within A-SLAM research. Furthermore, this article introduces a novel analysis of Active Collaborative SLAM (AC-SLAM), focusing on collaborative aspects within SLAM systems. It includes a thorough examination of collaborative parameters and approaches, supported by both qualitative and statistical assessments. This study also identifies limitations in the existing literature and suggests potential avenues for future research. This survey serves as a valuable resource for researchers seeking insights into A-SLAM methods and techniques, offering a current overview of A-SLAM formulation.
Selective Nonparametric Regression via Testing
Noskov, Fedor, Fishkov, Alexander, Panov, Maxim
Prediction with the possibility of abstention (or selective prediction) is an important problem for error-critical machine learning applications. While well-studied in the classification setup, selective approaches to regression are much less developed. In this work, we consider the nonparametric heteroskedastic regression problem and develop an abstention procedure via testing the hypothesis on the value of the conditional variance at a given point. Unlike existing methods, the proposed one allows to account not only for the value of the variance itself but also for the uncertainty of the corresponding variance predictor. We prove non-asymptotic bounds on the risk of the resulting estimator and show the existence of several different convergence regimes. Theoretical analysis is illustrated with a series of experiments on simulated and real-world data.
Beyond Reverse KL: Generalizing Direct Preference Optimization with Diverse Divergence Constraints
Wang, Chaoqi, Jiang, Yibo, Yang, Chenghao, Liu, Han, Chen, Yuxin
The increasing capabilities of large language models (LLMs) raise opportunities for artificial general intelligence but concurrently amplify safety concerns, such as potential misuse of AI systems, necessitating effective AI alignment. Reinforcement Learning from Human Feedback (RLHF) has emerged as a promising pathway towards AI alignment but brings forth challenges due to its complexity and dependence on a separate reward model. Direct Preference Optimization (DPO) has been proposed as an alternative, and it remains equivalent to RLHF under the reverse KL regularization constraint. This paper presents $f$-DPO, a generalized approach to DPO by incorporating diverse divergence constraints. We show that under certain $f$-divergences, including Jensen-Shannon divergence, forward KL divergences and $\alpha$-divergences, the complex relationship between the reward and optimal policy can also be simplified by addressing the Karush-Kuhn-Tucker conditions. This eliminates the need for estimating the normalizing constant in the Bradley-Terry model and enables a tractable mapping between the reward function and the optimal policy. Our approach optimizes LLMs to align with human preferences in a more efficient and supervised manner under a broad set of divergence constraints. Empirically, adopting these divergences ensures a balance between alignment performance and generation diversity. Importantly, $f$-DPO outperforms PPO-based methods in divergence efficiency, and divergence constraints directly influence expected calibration error (ECE).
Towards a Causal Probabilistic Framework for Prediction, Action-Selection & Explanations for Robot Block-Stacking Tasks
Cannizzaro, Ricardo, Routley, Jonathan, Kunze, Lars
Uncertainties in the real world mean that is impossible for system designers to anticipate and explicitly design for all scenarios that a robot might encounter. Thus, robots designed like this are fragile and fail outside of highly-controlled environments. Causal models provide a principled framework to encode formal knowledge of the causal relationships that govern the robot's interaction with its environment, in addition to probabilistic representations of noise and uncertainty typically encountered by real-world robots. Combined with causal inference, these models permit an autonomous agent to understand, reason about, and explain its environment. In this work, we focus on the problem of a robot block-stacking task due to the fundamental perception and manipulation capabilities it demonstrates, required by many applications including warehouse logistics and domestic human support robotics. We propose a novel causal probabilistic framework to embed a physics simulation capability into a structural causal model to permit robots to perceive and assess the current state of a block-stacking task, reason about the next-best action from placement candidates, and generate post-hoc counterfactual explanations. We provide exemplar next-best action selection results and outline planned experimentation in simulated and real-world robot block-stacking tasks.
How artificial intelligence is helping keep Indigenous languages alive
LEARNING a language used to mean sitting in a classroom and memorising hundreds of words. But thanks to apps like Duolingo, you can take a quick French lesson on your phone between meetings. Or you can use Google Translate to help you read French instead. As miraculous as these apps are, they don't work for everyone – especially if you speak an Indigenous language in regions like North America or New Zealand, where European settlers made …
Generative Semi-supervised Learning with Meta-Optimized Synthetic Samples
Semi-supervised learning (SSL) is a promising approach for training deep classification models using labeled and unlabeled datasets. However, existing SSL methods rely on a large unlabeled dataset, which may not always be available in many real-world applications due to legal constraints (e.g., GDPR). In this paper, we investigate the research question: Can we train SSL models without real unlabeled datasets? Instead of using real unlabeled datasets, we propose an SSL method using synthetic datasets generated from generative foundation models trained on datasets containing millions of samples in diverse domains (e.g., ImageNet). Our main concepts are identifying synthetic samples that emulate unlabeled samples from generative foundation models and training classifiers using these synthetic samples. To achieve this, our method is formulated as an alternating optimization problem: (i) meta-learning of generative foundation models and (ii) SSL of classifiers using real labeled and synthetic unlabeled samples. For (i), we propose a meta-learning objective that optimizes latent variables to generate samples that resemble real labeled samples and minimize the validation loss. For (ii), we propose a simple unsupervised loss function that regularizes the feature extractors of classifiers to maximize the performance improvement obtained from synthetic samples. We confirm that our method outperforms baselines using generative foundation models on SSL. We also demonstrate that our methods outperform SSL using real unlabeled datasets in scenarios with extremely small amounts of labeled datasets. This suggests that synthetic samples have the potential to provide improvement gains more efficiently than real unlabeled data.
Unsupervised Movement Detection in Indoor Positioning Systems of Production Halls
Flossdorf, Jonathan, Meyer, Anne, Artjuch, Dmitri, Schneider, Jaques, Jentsch, Carsten
Consider indoor positioning systems (IPS) in production There exist various survey papers of different technological halls where objects equipped with sensors send their current approaches and potentials [6, 7, 8]. Beside its large volume, the analyzation of focus on the particular application of IPS in production the resulting raw data is challenging due to the susceptibility halls of manufacturing companies where satellites are attached towards noise. Reasons are accuracy issues and at various points of the hall and communicate with undesired awakenings of sensors that occur due to the mobile receivers equipped with sensors which can locate dynamics of logistic processes (e.g. We propose a tailor-made statistical procedure components can be individually tracked. Beside obvious for these challenges and combine visual analytics with benefits like reduced search efforts, these systems have movement detection. Contrary to common stay-point algorithms, secondary advantages on assistance systems, fault management we do not only distinguish between stops and or production control [9, 10]. This leads to a more detailed interpretation scheme offering 1.1 Data and Problem Specification usages for online (e.g.
The Creator review – vast and exhilarating sci-fi actioner rages against the AI machine
This colossal sci-fi thriller from Gareth Edwards features John David Washington and Gemma Chan in vast mysterious panoramas and vertiginous vistas which deserve to be shown at Imax-plus scale; it also shows that Christopher Nolan isn't the only British director in Hollywood thinking (and acting) big. After a stint making franchise movies such as Godzilla and the enjoyable and underrated Rogue One: A Star Wars Story, Edwards has now crafted this ambitious original picture, co-written with Chris Weitz, which is closer in spirit to his ingenious 2010 debut Monsters. The Creator is an old-fashioned science-fiction actioner with some ideas to match to state-of-the-art digital effects, in the tradition of Ridley Scott's Blade Runner or Neill Blomkamp's District 9, with a creeping colonialist's fear of the unknown to match that in Coppola's Apocalypse Now. And given that Edwards has served some time aboard the Star Wars mother ship, it shouldn't be too surprising to find some holograms in the mix and a certain dustbin-sized droid which whimpers something poignant about what an honour it's been to serve his comrades before lumbering out to face the enemy on a kamikaze mission. Washington shows us some more of that distinctive self-possession and even slight hauteur as a performer, in playing Josh, a US army special forces undercover officer, fighting a strange, dirty war in a postnuclear world upended by the dominance of artificial intelligence.
Learning Stable and Robust Linear Parameter-Varying State-Space Models
Verhoek, Chris, Wang, Ruigang, Tóth, Roland
This paper presents two direct parameterizations of stable and robust linear parameter-varying state-space (LPV-SS) models. The model parametrizations guarantee a priori that for all parameter values during training, the allowed models are stable in the contraction sense or have their Lipschitz constant bounded by a user-defined value $\gamma$. Furthermore, since the parametrizations are direct, the models can be trained using unconstrained optimization. The fact that the trained models are of the LPV-SS class makes them useful for, e.g., further convex analysis or controller design. The effectiveness of the approach is demonstrated on an LPV identification problem.
FDLS: A Deep Learning Approach to Production Quality, Controllable, and Retargetable Facial Performances
Ma, Wan-Duo Kurt, Ghifary, Muhammad, Lewis, J. P., Choi, Byungkuk, Eom, Haekwang
Visual effects commonly requires both the creation of realistic synthetic humans as well as retargeting actors' performances to humanoid characters such as aliens and monsters. Achieving the expressive performances demanded in entertainment requires manipulating complex models with hundreds of parameters. Full creative control requires the freedom to make edits at any stage of the production, which prohibits the use of a fully automatic ``black box'' solution with uninterpretable parameters. On the other hand, producing realistic animation with these sophisticated models is difficult and laborious. This paper describes FDLS (Facial Deep Learning Solver), which is Weta Digital's solution to these challenges. FDLS adopts a coarse-to-fine and human-in-the-loop strategy, allowing a solved performance to be verified and edited at several stages in the solving process. To train FDLS, we first transform the raw motion-captured data into robust graph features. Secondly, based on the observation that the artists typically finalize the jaw pass animation before proceeding to finer detail, we solve for the jaw motion first and predict fine expressions with region-based networks conditioned on the jaw position. Finally, artists can optionally invoke a non-linear finetuning process on top of the FDLS solution to follow the motion-captured virtual markers as closely as possible. FDLS supports editing if needed to improve the results of the deep learning solution and it can handle small daily changes in the actor's face shape. FDLS permits reliable and production-quality performance solving with minimal training and little or no manual effort in many cases, while also allowing the solve to be guided and edited in unusual and difficult cases. The system has been under development for several years and has been used in major movies.