Goto

Collaborating Authors

 Education


California Berkeley university campus worker finds human skeleton in unused residence building: police

FOX News

Fox News Flash top headlines are here. Check out what's clicking on Foxnews.com. Skeletonized human remains were found in an unused residence hall on the campus of University of California, Berkeley last week, officials said. The skeleton was found in the shuttered graffiti-ridden building on the Clark Kerr Campus on Jan. 10, but it remains unclear how many years the remains were there, police said. FILE: A view of the UC Berkeley campus is seen from this drone view in Berkeley, Calif., on Monday, Nov. 28, 2022.


Explainable Data Poison Attacks on Human Emotion Evaluation Systems based on EEG Signals

arXiv.org Artificial Intelligence

The major aim of this paper is to explain the data poisoning attacks using label-flipping during the training stage of the electroencephalogram (EEG) signal-based human emotion evaluation systems deploying Machine Learning models from the attackers' perspective. Human emotion evaluation using EEG signals has consistently attracted a lot of research attention. The identification of human emotional states based on EEG signals is effective to detect potential internal threats caused by insider individuals. Nevertheless, EEG signal-based human emotion evaluation systems have shown several vulnerabilities to data poison attacks. The findings of the experiments demonstrate that the suggested data poison assaults are model-independently successful, although various models exhibit varying levels of resilience to the attacks. In addition, the data poison attacks on the EEG signal-based human emotion evaluation systems are explained with several Explainable Artificial Intelligence (XAI) methods, including Shapley Additive Explanation (SHAP) values, Local Interpretable Model-agnostic Explanations (LIME), and Generated Decision Trees. And the codes of this paper are publicly available on GitHub.


Monotonicity for AI ethics and society: An empirical study of the monotonic neural additive model in criminology, education, health care, and finance

arXiv.org Artificial Intelligence

Algorithm fairness in the application of artificial intelligence (AI) is essential for a better society. As the foundational axiom of social mechanisms, fairness consists of multiple facets. Although the machine learning (ML) community has focused on intersectionality as a matter of statistical parity, especially in discrimination issues, an emerging body of literature addresses another facet -- monotonicity. Based on domain expertise, monotonicity plays a vital role in numerous fairness-related areas, where violations could misguide human decisions and lead to disastrous consequences. In this paper, we first systematically evaluate the significance of applying monotonic neural additive models (MNAMs), which use a fairness-aware ML algorithm to enforce both individual and pairwise monotonicity principles, for the fairness of AI ethics and society. We have found, through a hybrid method of theoretical reasoning, simulation, and extensive empirical analysis, that considering monotonicity axioms is essential in all areas of fairness, including criminology, education, health care, and finance. Our research contributes to the interdisciplinary research at the interface of AI ethics, explainable AI (XAI), and human-computer interactions (HCIs). By evidencing the catastrophic consequences if monotonicity is not met, we address the significance of monotonicity requirements in AI applications. Furthermore, we demonstrate that MNAMs are an effective fairness-aware ML approach by imposing monotonicity restrictions integrating human intelligence.


Enhancing Self-Training Methods

arXiv.org Artificial Intelligence

Semi-supervised learning approaches train on small sets of labeled data along with large sets of unlabeled data. Self-training is a semi-supervised teacher-student approach that often suffers from the problem of "confirmation bias" that occurs when the student model repeatedly overfits to incorrect pseudo-labels given by the teacher model for the unlabeled data. This bias impedes improvements in pseudo-label accuracy across self-training iterations, leading to unwanted saturation in model performance after just a few iterations. In this work, we describe multiple enhancements to improve the self-training pipeline to mitigate the effect of confirmation bias. We evaluate our enhancements over multiple datasets showing performance gains over existing self-training design choices. Finally, we also study the extendability of our enhanced approach to Open Set unlabeled data (containing classes not seen in labeled data).


BERT-ERC: Fine-tuning BERT is Enough for Emotion Recognition in Conversation

arXiv.org Artificial Intelligence

Previous works on emotion recognition in conversation (ERC) follow a two-step paradigm, which can be summarized as first producing context-independent features via fine-tuning pretrained language models (PLMs) and then analyzing contextual information and dialogue structure information among the extracted features. However, we discover that this paradigm has several limitations. Accordingly, we propose a novel paradigm, i.e., exploring contextual information and dialogue structure information in the fine-tuning step, and adapting the PLM to the ERC task in terms of input text, classification structure, and training strategy. Furthermore, we develop our model BERT-ERC according to the proposed paradigm, which improves ERC performance in three aspects, namely suggestive text, fine-grained classification module, and two-stage training. Compared to existing methods, BERT-ERC achieves substantial improvement on four datasets, indicating its effectiveness and generalization capability. Besides, we also set up the limited resources scenario and the online prediction scenario to approximate real-world scenarios. Extensive experiments demonstrate that the proposed paradigm significantly outperforms the previous one and can be adapted to various scenes.


The SwaNNFlight System: On-the-Fly Sim-to-Real Adaptation via Anchored Learning

arXiv.org Artificial Intelligence

Reinforcement Learning (RL) agents trained in simulated environments and then deployed in the real world are often sensitive to the differences in dynamics presented, commonly termed the sim-to-real gap. With the goal of minimizing this gap on resource-constrained embedded systems, we train and live-adapt agents on quadrotors built from off-the-shelf hardware. In achieving this we developed three novel contributions. (i) SwaNNFlight, an open-source firmware enabling wireless data capture and transfer of agents' observations. Fine-tuning agents with new data, and receiving and swapping onboard NN controllers -- all while in flight. We also design SwaNNFlight System (SwaNNFS) allowing new research in training and live-adapting learning agents on similar systems. (ii) Multiplicative value composition, a technique for preserving the importance of each policy optimization criterion, improving training performance and variability in learnt behavior. And (iii) anchor critics to help stabilize the fine-tuning of agents during sim-to-real transfer, online learning from real data while retaining behavior optimized in simulation. We train consistently flight-worthy control policies in simulation and deploy them on real quadrotors. We then achieve live controller adaptation via over-the-air updates of the onboard control policy from a ground station. Our results indicate that live adaptation unlocks a near-50\% reduction in power consumption, attributed to the sim-to-real gap. Finally, we tackle the issues of catastrophic forgetting and controller instability, showing the effectiveness of our novel methods. Project Website: https://github.com/BU-Cyber-Physical-Systems-Lab/SwaNNFS


Online Filtering over Expanding Graphs

arXiv.org Artificial Intelligence

Data processing tasks over graphs couple the data residing over the nodes with the topology through graph signal processing tools. Graph filters are one such prominent tool, having been used in applications such as denoising, interpolation, and classification. However, they are mainly used on fixed graphs although many networks grow in practice, with nodes continually attaching to the topology. Re-training the filter every time a new node attaches is computationally demanding; hence an online learning solution that adapts to the evolving graph is needed. We propose an online update of the filter, based on the principles of online machine learning. To update the filter, we perform online gradient descent, which has a provable regret bound with respect to the filter computed offline. We show the performance of our method for signal interpolation at the incoming nodes. Numerical results on synthetic and graph-based recommender systems show that the proposed approach compares well to the offline baseline filter while outperforming competitive approaches. These findings lay the foundation for efficient filtering over expanding graphs.


Convergence of First-Order Algorithms for Meta-Learning with Moreau Envelopes

arXiv.org Artificial Intelligence

In this work, we consider the problem of minimizing the sum of Moreau envelopes of given functions, which has previously appeared in the context of meta-learning and personalized federated learning. In contrast to the existing theory that requires running subsolvers until a certain precision is reached, we only assume that a finite number of gradient steps is taken at each iteration. As a special case, our theory allows us to show the convergence of First-Order Model-Agnostic Meta-Learning (FO-MAML) to the vicinity of a solution of Moreau objective. We also study a more general family of first-order algorithms that can be viewed as a generalization of FO-MAML. Our main theoretical achievement is a theoretical improvement upon the inexact SGD framework. In particular, our perturbed-iterate analysis allows for tighter guarantees that improve the dependency on the problem's conditioning. In contrast to the related work on meta-learning, ours does not require any assumptions on the Hessian smoothness, and can leverage smoothness and convexity of the reformulation based on Moreau envelopes. Furthermore, to fill the gaps in the comparison of FO-MAML to the Implicit MAML (iMAML), we show that the objective of iMAML is neither smooth nor convex, implying that it has no convergence guarantees based on the existing theory.


Bag of States: A Non-sequential Approach to Video-based Engagement Measurement

arXiv.org Artificial Intelligence

Automatic measurement of student engagement provides helpful information for instructors to meet learning program objectives and individualize program delivery. Students' behavioral and emotional states need to be analyzed at fine-grained time scales in order to measure their level of engagement. Many existing approaches have developed sequential and spatiotemporal models, such as recurrent neural networks, temporal convolutional networks, and three-dimensional convolutional neural networks, for measuring student engagement from videos. These models are trained to incorporate the order of behavioral and emotional states of students into video analysis and output their level of engagement. In this paper, backed by educational psychology, we question the necessity of modeling the order of behavioral and emotional states of students in measuring their engagement. We develop bag-of-words-based models in which only the occurrence of behavioral and emotional states of students is modeled and analyzed and not the order in which they occur. Behavioral and affective features are extracted from videos and analyzed by the proposed models to determine the level of engagement in an ordinal-output classification setting. Compared to the existing sequential and spatiotemporal approaches for engagement measurement, the proposed non-sequential approach improves the state-of-the-art results. According to experimental results, our method significantly improved engagement level classification accuracy on the IIITB Online SE dataset by 26% compared to sequential models and achieved engagement level classification accuracy as high as 66.58% on the DAiSEE student engagement dataset.


Top 16 Artificial Intelligence Applications: 14 Uses of AI

#artificialintelligence

Artificial intelligence (AI) is hailed as the disruptive technology that is set to revolutionize the 21st century. The function and popularity of this technology are soaring by the day. It has the potential to solve many of humanity's most pressing problems. AI is an umbrella term for technologies that can display some kind of intelligence such as machine learning computer vision, natural language processing, etc… These intelligent agents are algorithms trained using vast amounts of data to give machines some kind of reasoning ability. Instead of purely logical processing that computers usually perform, intelligent agents are designed around human thinking patterns and problem-solving skills. Artificial intelligence technologies create intelligent systems capable of self-learning and adapting to any new challenge. These specification has led to the rapid adoption of AI across different fields and industries around the world. Artificial intelligence has been around for decades, but its applications are only now opening up as more and more resources are dedicated to it. Over the last few years, AI has significantly evolved and is being extensively used in different aspects of human life and industry. Companies have begun using intelligent machines to mine data to optimize just about everything within their business operations. Artificial intelligence is a branch of computer science that aims to create intelligent machines that work and react like humans. It is the broad term for any device that is capable of performing a task normally restricted to human intelligence. AI combines several disciplines such as computer science, cognitive psychology, and neuroscience. The concept underlying AI is to get a non-human entity to make decisions just as an intelligent human would. Artificial intelligence research is about the creation of computer systems capable of visual perception, speech recognition, decision-making, and translation between languages. So many fields are using AI nowadays, from research and home automation to data processing and analysis. The technology is used to solve problems in many different ways and it is found in many types of systems such as household appliances, automobiles, financial systems, medical applications, and many other common tools. AI has undergone rapid development over the past decades, fueled by significant research and trail-blazing technological advancements. Nowadays, it is often used to make computer programs better than humans at perception and cognition tasks. AI technologies are on an exponential level of development and are becoming so advanced that it is entering nearly every field of modern life.