specification
Bayesian Inference of Temporal Task Specifications from Demonstrations
When observing task demonstrations, human apprentices are able to identify whether a given task is executed correctly long before they gain expertise in actually performing that task. Prior research into learning from demonstrations (LfD) has failed to capture this notion of the acceptability of an execution; meanwhile, temporal logics provide a flexible language for expressing task specifications. Inspired by this, we present Bayesian specification inference, a probabilistic model for inferring task specification as a temporal logic formula. We incorporate methods from probabilistic programming to define our priors, along with a domain-independent likelihood function to enable sampling-based inference. We demonstrate the efficacy of our model for inferring true specifications with over 90% similarity between the inferred specification and the ground truth, both within a synthetic domain and a real-world table setting task.
Variational Inference for Bayesian MIDAS Regression
We develop a Coordinate Ascent Variational Inference (CAVI) algorithm for Bayesian Mixed Data Sampling (MIDAS) regression with linear weight parameterizations. The model separates impact coeffcients from weighting function parameters through a normalization constraint, creating a bilinear structure that renders generic Hamiltonian Monte Carlo samplers unreliable while preserving conditional conjugacy exploitable by CAVI. Each variational update admits a closed-form solution: Gaussian for regression coefficients and weight parameters, Inverse-Gamma for the error variance. The algorithm propagates uncertainty across blocks through second moments, distinguishing it from naive plug-in approximations. In a Monte Carlo study spanning 21 data-generating configurations with up to 50 predictors, CAVI produces posterior means nearly identical to a block Gibbs sampler benchmark while achieving speedups of 107x to 1,772x (Table 9). Generic automatic differentiation VI (ADVI), by contrast, produces bias 714 times larger while being orders of magnitude slower, confirming the value of model-specific derivations. Weight function parameters maintain excellent calibration (coverage above 92%) across all configurations. Impact coefficient credible intervals exhibit the underdispersion characteristic of mean-field approximations, with coverage declining from 89% to 55% as the number of predictors grows a documented trade-off between speed and interval calibration that structured variational methods can address. An empirical application to realized volatility forecasting on S&P 500 daily returns cofirms that CAVI and Gibbs sampling yield virtually identical point forecasts, with CAVI completing each monthly estimation in under 10 milliseconds.
Learning Task Specifications from Demonstrations
In many settings (e.g., robotics) demonstrations provide a natural way to specify the sub-tasks. However, most methods for learning from demonstrations either do not provide guarantees that the artifacts learned for the sub-tasks can be safely recombined or limit the types of composition available. Motivated by this deficit, we consider the problem of inferring Boolean non-Markovian rewards (also known as logical trace properties or specifications) from demonstrations provided by an agent operating in an uncertain, stochastic environment. Crucially, specifications admit well-defined composition rules that are typically easy to interpret. In this paper, we formulate the specification inference task as a maximum a posteriori (MAP) probability inference problem, apply the principle of maximum entropy to derive an analytic demonstration likelihood model and give an efficient approach to search for the most likely specification in a large candidate pool of specifications. In our experiments, we demonstrate how learning specifications can help avoid common problems that often arise due to ad-hoc reward composition.
- North America > United States > California > Los Angeles County > Los Angeles (0.14)
- North America > United States > Massachusetts > Middlesex County > Lexington (0.04)
- North America > United States > Massachusetts > Middlesex County > Cambridge (0.04)
- (4 more...)
- Research Report > New Finding (1.00)
- Research Report > Experimental Study > Negative Result (0.67)
- Education > Educational Setting (1.00)
- Government > Military (0.93)
- Government > Regional Government > North America Government > United States Government (0.93)
- Information Technology > Artificial Intelligence > Robots (1.00)
- Information Technology > Artificial Intelligence > Machine Learning (1.00)
- Information Technology > Artificial Intelligence > Natural Language (0.93)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Logic & Formal Reasoning (0.90)
- North America > United States > California > San Francisco County > San Francisco (0.14)
- North America > United States > California > Los Angeles County > Los Angeles (0.14)
- North America > Canada > Ontario > Toronto (0.14)
- (11 more...)
- Information Technology > Artificial Intelligence > Representation & Reasoning (1.00)
- Information Technology > Artificial Intelligence > Machine Learning > Reinforcement Learning (1.00)
- Information Technology > Artificial Intelligence > Machine Learning > Learning Graphical Models > Undirected Networks > Markov Models (0.46)
- Europe > Germany > Baden-Württemberg > Tübingen Region > Tübingen (0.04)
- North America > United States (0.04)
- Information Technology (1.00)
- Transportation (0.67)
- Information Technology (0.93)
- Leisure & Entertainment > Games > Computer Games (0.69)
- Education (0.67)
- South America > Peru > Cusco Department > Cusco Province > Cusco (0.04)
- North America > United States > Pennsylvania > Allegheny County > Pittsburgh (0.04)
- Leisure & Entertainment (0.67)
- Education > Educational Setting > Online (0.67)
- Information Technology > Artificial Intelligence > Robots (1.00)
- Information Technology > Artificial Intelligence > Machine Learning > Reinforcement Learning (1.00)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Agents (0.67)
- Information Technology > Artificial Intelligence > Machine Learning > Neural Networks > Deep Learning (0.67)
- North America > United States (0.28)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.13)
- South America > Chile > Santiago Metropolitan Region > Santiago Province > Santiago (0.04)
- Research Report > Experimental Study (1.00)
- Research Report > New Finding (0.92)
- Workflow (0.67)
- Health & Medicine > Therapeutic Area > Oncology (1.00)
- Health & Medicine > Pharmaceuticals & Biotechnology (1.00)
- Health & Medicine > Epidemiology (0.93)