Energy
Open Challenges in Time Series Anomaly Detection: An Industry Perspective
Current research in time-series anomaly detection is using definitions that miss critical aspects of how anomaly detection is commonly used in practice. We list several areas that are of practical relevance and that we believe are either under-investigated or missing entirely from the current discourse. Based on an investigation of systems deployed in a cloud environment, we motivate the areas of streaming algorithms, human-in-the-loop scenarios, point processes, conditional anomalies and populations analysis of time series. This paper serves as a motivation and call for action, including opportunities for theoretical and applied research, as well as for building new dataset and benchmarks.
Real Time Control of Tandem-Wing Experimental Platform Using Concerto Reinforcement Learning
Minghao, Zhang, Xiaojun, Yang, Zhihe, Wang, Liang, Wang
Recent advancements in motor technology and f abrication techniques, have significantly enhanced the performance of hover - capable flapping - wing aircraft, thereby demonstrating greater application flexibility [1 - 7] . Dragonfly - inspired hover - capable flapping - wing aircraft utilize a unique four - wing independent drive mechanism, enhancing maneuverability [8 - 11], Consequently, various types of dragonfly - inspired aircraft have been developed in recent years, including those employing mechanical structures to generate the reciprocating motions necessary for lift and asymmetric wing movements for control torques [12 - 14], as well as direct - drive aircraft utilizing miniature servo motors to simultaneously achieve reciprocating motions for lift and asymmetric wing movements for control torques [8, 15] . Among these, direct - drive biomimetic aircraft, with control architectures and manipulations more akin to conventional robotics [16] and leveraging direct - drive characteristics [17 - 20] for improved performance, have attracted significant research interest [10, 21, 22] . A typical example is the DDD - 1 aircraft, developed by the authors' team and illustrated in Fig.1 [9, 10, 22 - 25] . This platform faces significant challenges due to nonlinear, unsteady aerodynamic interactions resulting from its tandem wings [9, 10, 25] . While sufficient lift is generated to enable vertical motion along a track, achieving stable hovering remains challenging owing to the need for more sophisticated control strategies in the presence of additional aerodynamic interference from closely spac ed tandem wings compared to direct - drive dual - wing aircraft. To address this issue and maintain similarity with the DDD - 1 while circumventing the limitations that existing experiments cannot directly apply results to airborne biomimetic aircraft [26, 27], the Direct - Drive Tandem - Wing Experiment Platform (DDTWEP), as shown in Fig.2, equipped with a six - component balance, has been developed to explore the pitch, roll, and yaw control strategies of four - wing direct - drive biomimetic aircraft under the nonline ar and unsteady aerodynamic interference of tandem wings.
Drones, cameras and metal detectors: Edison faces new scrutiny over start of Eaton fire
Armed with drones, long-distance camera lenses and metal detectors, a hillside in Eaton Canyon has become the focus of intense scrutiny over the last month by teams of private investigators now seeking clues on whether Southern California Edison equipment caused the massive fire that destroyed large swaths of Altadena. Some of the findings and theories of these privately hired teams of fire investigators and electrical engineers have emerged in more than 40 lawsuits that residents have filed against the utility. Much of the focus has been centered on a group of transmission towers where the first flames were seen just as the Eaton fire exploded. Earlier this week, a new lawsuit alleged that an idle transmission tower on the hillside -- one that has not been in use for more than 50 years -- might have sparked the devastating blaze. With more than 9,000 homes lost and 17 people killed, liability is going to be a costly question that could affect how Altadena is rebuilt.
Explained: Generative AI's environmental impact
In a two-part series, MIT News explores the environmental implications of generative AI. In this article, we look at why this technology is so resource-intensive. A second piece will investigate what experts are doing to reduce genAI's carbon footprint and other impacts. The excitement surrounding potential benefits of generative AI, from improving worker productivity to advancing scientific research, is hard to ignore. While the explosive growth of this new technology has enabled rapid deployment of powerful models in many industries, the environmental consequences of this generative AI "gold rush" remain difficult to pin down, let alone mitigate.
Smart windows take a page from nature's pinecone playbook
Keep your home comfortable without using a single watt of electricity. Have you ever wondered how a pine cone knows when to open and close? Now, researchers have taken this cue from nature to create something pretty cool for our homes. Let's dive into how this revolutionary window technology works, keeping your home comfortable without using a single watt of electricity. GET SECURITY ALERTS, EXPERT TIPS - SIGN UP FOR KURT'S NEWSLETTER - THE CYBERGUY REPORT HERE Pine cones have these amazing scales that respond to moisture.
Robust Reward Alignment via Hypothesis Space Batch Cutting
Xie, Zhixian, Zhang, Haode, Feng, Yizhe, Jin, Wanxin
Reward design for reinforcement learning and optimal control agents is challenging. Preference-based alignment addresses this by enabling agents to learn rewards from ranked trajectory pairs provided by humans. However, existing methods often struggle from poor robustness to unknown false human preferences. In this work, we propose a robust and efficient reward alignment method based on a novel and geometrically interpretable perspective: hypothesis space batched cutting. Our method iteratively refines the reward hypothesis space through "cuts" based on batches of human preferences. Within each batch, human preferences, queried based on disagreement, are grouped using a voting function to determine the appropriate cut, ensuring a bounded human query complexity. To handle unknown erroneous preferences, we introduce a conservative cutting method within each batch, preventing erroneous human preferences from making overly aggressive cuts to the hypothesis space. This guarantees provable robustness against false preferences. We evaluate our method in a model predictive control setting across diverse tasks, including DM-Control, dexterous in-hand manipulation, and locomotion. The results demonstrate that our framework achieves comparable or superior performance to state-of-the-art methods in error-free settings while significantly outperforming existing method when handling high percentage of erroneous human preferences.
Bilevel Multi-Armed Bandit-Based Hierarchical Reinforcement Learning for Interaction-Aware Self-Driving at Unsignalized Intersections
Peng, Zengqi, Wang, Yubin, Zheng, Lei, Ma, Jun
In this work, we present BiM-ACPPO, a bilevel multi-armed bandit-based hierarchical reinforcement learning framework for interaction-aware decision-making and planning at unsignalized intersections. Essentially, it proactively takes the uncertainties associated with surrounding vehicles (SVs) into consideration, which encompass those stemming from the driver's intention, interactive behaviors, and the varying number of SVs. Intermediate decision variables are introduced to enable the high-level RL policy to provide an interaction-aware reference, for guiding low-level model predictive control (MPC) and further enhancing the generalization ability of the proposed framework. By leveraging the structured nature of self-driving at unsignalized intersections, the training problem of the RL policy is modeled as a bilevel curriculum learning task, which is addressed by the proposed Exp3.S-based BiMAB algorithm. It is noteworthy that the training curricula are dynamically adjusted, thereby facilitating the sample efficiency of the RL training process. Comparative experiments are conducted in the high-fidelity CARLA simulator, and the results indicate that our approach achieves superior performance compared to all baseline methods. Furthermore, experimental results in two new urban driving scenarios clearly demonstrate the commendable generalization performance of the proposed method.
LLMs to Support a Domain Specific Knowledge Assistant
This work presents a custom approach to developing a domain specific knowledge assistant for sustainability reporting using the International Financial Reporting Standards (IFRS). In this domain, there is no publicly available question-answer dataset, which has impeded the development of a high-quality chatbot to support companies with IFRS reporting. The two key contributions of this project therefore are: (1) A high-quality synthetic question-answer (QA) dataset based on IFRS sustainability standards, created using a novel generation and evaluation pipeline leveraging Large Language Models (LLMs). This comprises 1,063 diverse QA pairs that address a wide spectrum of potential user queries in sustainability reporting. Various LLM-based techniques are employed to create the dataset, including chain-of-thought reasoning and few-shot prompting. A custom evaluation framework is developed to assess question and answer quality across multiple dimensions, including faithfulness, relevance, and domain specificity. The dataset averages a score range of 8.16 out of 10 on these metrics. (2) Two architectures for question-answering in the sustainability reporting domain - a RAG pipeline and a fully LLM-based pipeline. The architectures are developed by experimenting, fine-tuning, and training on the QA dataset. The final pipelines feature an LLM fine-tuned on domain specific data and an industry classification component to improve the handling of complex queries. The RAG architecture achieves an accuracy of 85.32% on single-industry and 72.15% on cross-industry multiple-choice questions, outperforming the baseline approach by 4.67 and 19.21 percentage points, respectively. The LLM-based pipeline achieves an accuracy of 93.45% on single-industry and 80.30% on cross-industry multiple-choice questions, an improvement of 12.80 and 27.36 percentage points over the baseline, respectively.
A data-driven two-microphone method for in-situ sound absorption measurements
Emmerich, Leon, Aste, Patrik, Brandรฃo, Eric, Nolan, Mรฉlanie, Cuenca, Jacques, Svensson, U. Peter, Maeder, Marcus, Marburg, Steffen, Zea, Elias
This work presents a data-driven approach to estimating the sound absorption coefficient of an infinite porous slab using a neural network and a two-microphone measurement on a finite porous sample. A 1D-convolutional network predicts the sound absorption coefficient from the complex-valued transfer function between the sound pressure measured at the two microphone positions. The network is trained and validated with numerical data generated by a boundary element model using the Delany-Bazley-Miki model, demonstrating accurate predictions for various numerical samples. The method is experimentally validated with baffled rectangular samples of a fibrous material, where sample size and source height are varied. The results show that the neural network offers the possibility to reliably predict the in-situ sound absorption of a porous material using the traditional two-microphone method as if the sample were infinite. The normal-incidence sound absorption coefficient obtained by the network compares well with that obtained theoretically and in an impedance tube. The proposed method has promising perspectives for estimating the sound absorption coefficient of acoustic materials after installation and in realistic operational conditions.
Dense Fixed-Wing Swarming using Receding-Horizon NMPC
Madabushi, Varun, Kopel, Yocheved, Polevoy, Adam, Moore, Joseph
Abstract-- In this paper, we present an approach for controlling a team of agile fixed-wing aerial vehicles in close proximity to one another. Our approach relies on recedinghorizon nonlinear model predictive control (NMPC) to plan maneuvers across an expanded flight envelope to enable interagent collision avoidance. To facilitate robust collision avoidance and characterize the likelihood of inter-agent collisions, we compute a statistical bound on the probability of the system leaving a tube around the planned nominal trajectory. Finally, we propose a metric for evaluating highly dynamic swarms and use this metric to evaluate our approach. We successfully demonstrated our approach through both simulation and hardware experiments, and to our knowledge, this the first time close-quarters swarming has been achieved with physical aerobatic fixed-wing vehicles.