Many sequential decision-making problems can be formulated as shortest-path problems, where the objective is to reach a goal state from a given starting state. Heuristic search is a standard approach for solving such problems, relying on a heuristic function to estimate the cost to the goal from any given state. Recent approaches leverage reinforcement learning to learn heuristics by applying deep approximate value iteration. These methods typically rely on single-step Bellman updates, where the heuristic of a state is updated based on its best neighbor and the corresponding edge cost. This work proposes a generalized approach that enhances both state sampling and heuristic updates by performing limited-horizon searches and updating each state's heuristic based on the shortest path to the search frontier, incorporating both edge costs and the heuristic values of frontier states.

Self-efficacy is a critical component of self-regulated learning (SRL), which empowers youth to overcome challenges and achieve learn- ing goals. In this study, we designed ALLURE, a multimodal artifi- cial intelligence (AI)-driven platform embodied with an XAI-driven chatbot to teach youth to solve a pathfinding problem, i.e., the Rubik's Cube, with the goal of improving their self-efficacy. Using ALLURE as a use case, we examine how various personas inter- act with an XAI-driven chatbot and how these interactions shape youths’ self-efficacy. Personas offer a valuable design and evalua- tion strategy for modeling learner variability, enabling designers to represent and respond to differences in cognitive styles, motiva- tional profiles, and affective states, especially in early-stage systems like XAI-driven chatbots. Through interviews, think-alouds, and observational notes from usability testing, the results of this pre- liminary study indicate that while XAI-driven chatbots enhance self-efficacy, their effectiveness is not uniform across all youth. Findings underscore the need for educational chatbots to accom- modate diverse learning needs and preferences. Further, study findings offer implications for developing XAI-driven chatbots that provide transparent, tailored interactions to foster self-efficacy and competency in educational contexts.

In the context of pathfinding, first-order logic allows for the expressive specification of goals. Using negation as failure, one can specify what must not be true in a goal state instead of what must be true, which can result in succinct goal specifications while also being computationally advantageous. However, due to non-monotonicity, integration of negation as failure can be cumbersome. To address this problem, we introduce conflict-driven goal reaching (CDGR), a conflict-driven algorithm for reaching goals specified with non-monotonic logic that refines a search for a goal state based on conflicts encountered during search. Our results show that CDGR results in significantly shorter paths and can significantly speed up search when compared to not taking conflicts into consideration. Furthermore, our results show that finding paths to goals can be much more efficient when goals are specified with negation as failure instead of without negation as failure.

Recently, methods such as DeepCubeA have used deep reinforcement learning to learn domain-specific heuristic functions in a largely domain-independent fashion. However, such methods either assume a predetermined goal or assume that goals will be given as fully-specified states. Therefore, specifying a set of goal states to these learned heuristic functions is often impractical. To address this issue, we introduce a method of training a heuristic function that estimates the distance between a given state and a set of goal states represented as a set of ground atoms in first-order logic. Furthermore, to allow for more expressive goal specification, we introduce techniques for specifying goals as answer set programs and using answer set solvers to discover sets of ground atoms that meet the specified goals. In our experiments with the Rubik's cube, sliding tile puzzles, and Sokoban, we show that we can specify and reach different goals without any need to re-train the heuristic function. Our code is publicly available at https://github.com/forestagostinelli/SpecGoal.

Modern artificial intelligence (AI) methods have been used to solve problems that many humans struggle to solve. This opens up new opportunities for knowledge discovery and education. We demonstrate ALLURE, an educational AI system for learning to solve the Rubik’s cube that is designed to help students improve their problem solving skills. ALLURE can both find and explain its own strategies for solving the Rubik’s cube as well as build on user-provided strategies. Collaboration between AI and user happens using visual and natural language modalities.

Developing the problem solving skills of children is a challenging problem that is crucial for the future of our society. Given that artificial intelligence (AI) has been used to solve problems across a wide variety of domains, AI offers unique opportunities to develop problem solving skills using a multitude of tasks that pique the curiosity of children. To make this a reality, it is necessary to address the uninterpretable “black-box” that AI often appears to be. Towards this goal, we design a collaborative artificial intelligence algorithm that uses a human-in-the-loop approach to allow students to discover their own personalized solutions to problems. This collaborative algorithm builds on state-of-the-art AI algorithms and leverages additional interpretable structures, namely knowledge graphs and decision trees, to create a fully interpretable process that is able to explain solutions in their entirety. We describe this algorithm when applied to solving the Rubik’s cube as well as our planned user-interface and assessment methods.

In this paper, we develop a new aggregation technique to reduce the cost of surveying. Our method aims to jointly estimate a vector of target quantities such as public opinion or voter intent across time and maintain good estimates when using only a fraction of the data. Inspired by the James-Stein estimator, we resolve this challenge by shrinking the estimates to a global mean which is assumed to have a sparse representation in some known basis. This assumption has lead to two different methods for estimating the global mean: orthogonal matching pursuit and deep learning. Both of which significantly reduce the number of samples needed to achieve good estimates of the true means of the data and, in the case of presidential elections, can estimate the outcome of the 2012 United States elections while saving hundreds of thousands of samples and maintaining accuracy.

MOTIVATION: Circadian rhythms date back to the origins of life, are found in virtually every species and every cell, and play fundamental roles in functions ranging from metabolism to cognition. Modern high-throughput technologies allow the measurement of concentrations of transcripts, metabolites and other species along the circadian cycle creating novel computational challenges and opportunities, including the problems of inferring whether a given species oscillate in circadian fashion or not, and inferring the time at which a set of measurements was taken. RESULTS: We first curate several large synthetic and biological time series datasets containing labels for both periodic and aperiodic signals. We then use deep learning methods to develop and train BIO_CYCLE, a system to robustly estimate which signals are periodic in high-throughput circadian experiments, producing estimates of amplitudes, periods, phases, as well as several statistical significance measures. Using the curated data, BIO_CYCLE is compared to other approaches and shown to achieve state-of-the-art performance across multiple metrics. We then use deep learning methods to develop and train BIO_CLOCK to robustly estimate the time at which a particular single-time-point transcriptomic experiment was carried. In most cases, BIO_CLOCK can reliably predict time, within approximately 1 h, using the expression levels of only a small number of core clock genes. BIO_CLOCK is shown to work reasonably well across tissue types, and often with only small degradation across conditions. BIO_CLOCK is used to annotate most mouse experiments found in the GEO database with an inferred time stamp. AVAILABILITY AND IMPLEMENTATION: All data and software are publicly available on the CircadiOmics web portal: circadiomics.igb.uci.edu/ CONTACTS: [email protected] or [email protected] SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Bioinformatics (2016) 32(12), i8–i17 doi: 10.1093/bioinformatics/btw243 The authors wish to correct the following errors in the above article: In Section 2.1.2, Arabdiposis should read Arabidopsis, in Sections 2.1.2 and 4.4.1, Cyr1 should read Cry1, and in Section 3.1.5, V ;> ;V(i) should read V(i) ;> ;V. The authors apologize for these errors.

Stacked sparse denoising auto-encoders (SSDAs) have recently been shown to be successful at removing noise from corrupted images. However, like most denoising techniques, the SSDA is not robust to variation in noise types beyond what it has seen during training. We present the multi-column stacked sparse denoising autoencoder, a novel technique of combining multiple SSDAs into a multi-column SSDA (MC-SSDA) by combining the outputs of each SSDA. We eliminate the need to determine the type of noise, let alone its statistics, at test time. We show that good denoising performance can be achieved with a single system on a variety of different noise types, including ones not seen in the training set. Additionally, we experimentally demonstrate the efficacy of MC-SSDA denoising by achieving MNIST digit error rates on denoised images at close to that of the uncorrupted images.