Pacific Ocean
TPRNN: A Top-Down Pyramidal Recurrent Neural Network for Time Series Forecasting
Time series refer to a series of data points indexed in time order, which can be found in various fields, e.g., transportation, healthcare, and finance. Accurate time series forecasting can enhance optimization planning and decision-making support. Time series have multi-scale characteristics, i.e., different temporal patterns at different scales, which presents a challenge for time series forecasting. In this paper, we propose TPRNN, a Top-down Pyramidal Recurrent Neural Network for time series forecasting. We first construct subsequences of different scales from the input, forming a pyramid structure. Then by executing a multi-scale information interaction module from top to bottom, we model both the temporal dependencies of each scale and the influences of subsequences of different scales, resulting in a complete modeling of multi-scale temporal patterns in time series. Experiments on seven real-world datasets demonstrate that TPRNN has achieved the state-of-the-art performance with an average improvement of 8.13% in MSE compared to the best baseline.
BioinspiredLLM: Conversational Large Language Model for the Mechanics of Biological and Bio-inspired Materials
Luu, Rachel K., Buehler, Markus J.
The study of biological materials and bio-inspired materials science is well established; however, surprisingly little knowledge has been systematically translated to engineering solutions. To accelerate discovery and guide insights, an open-source autoregressive transformer large language model (LLM), BioinspiredLLM, is reported. The model was finetuned with a corpus of over a thousand peer-reviewed articles in the field of structural biological and bio-inspired materials and can be prompted to recall information, assist with research tasks, and function as an engine for creativity. The model has proven that it is able to accurately recall information about biological materials and is further enhanced with enhanced reasoning ability, as well as with retrieval-augmented generation to incorporate new data during generation that can also help to traceback sources, update the knowledge base, and connect knowledge domains. BioinspiredLLM also has been shown to develop sound hypotheses regarding biological materials design and remarkably so for materials that have never been explicitly studied before. Lastly, the model showed impressive promise in collaborating with other generative artificial intelligence models in a workflow that can reshape the traditional materials design process. This collaborative generative artificial intelligence method can stimulate and enhance bio-inspired materials design workflows. Biological materials are at a critical intersection of multiple scientific fields and models like BioinspiredLLM help to connect knowledge domains.
'Fox News Sunday' on December 3, 2023
Chairman of the Joint Chiefs of Staff Gen. Charles Q. Brown Jr. joins'Fox News Sunday' to discuss a new survey that revealed 74% of Americans are concerned about a war between the U.S. and China. This is a rush transcript of'Fox News Sunday' on December 3, 2023. This copy may not be in its final form and may be updated. A special hour on the state of defense, a report card on America's military readiness to meet the challenges of an increasingly dangerous world. Israel's war with Hamas, the latest conflict to ignite instability, turbo- charging attacks on our forces in the region from Iranian proxies. We'll get reaction from National Security Council Communications Coordinator John Kirby about the restart of the war and the headwinds the Biden White House faces from Democrats over conditioning future aid to Israel. GENERAL C.Q. BROWN, JOINT CHIEFS CHAIRMAN: We want to be so good at what we do that our adversaries go, not today, not tomorrow, not ever. General C.Q. Brown joins me here at the Reagan Library. And before serving in Congress, they served several tours of duty on the ground in two of America's longest wars. We sit down with Congressman Michael Waltz and Seth Moulton, veterans for both sides of the aisle, as the fight over defense spending is coming up against the stark deadline. Plus -- JENNIFER GRIFFIN, FOX NEWS NATIONAL SECURITY CORRESPONDENT: Is it cool to be patriotic now? UNIDENTIFIED MALE: It's always been cool to be contrarian and I think right now, it's -- it's been a little contrarian to be very patriotic. BREAM: Our inside look at how cutting-edge technology is shaping the future of warfare and battlefields worldwide. Here are the top headlines making news today. Israel is widening its evacuation orders for Palestinians in southern Gaza, including in and around the cities of Khan Younis and Rafah, which both reported heavy bombardment overnight. Israeli Prime Minister Benjamin Netanyahu calling for a total victory against Hamas and pushing back against White House calls to allow the Palestinian Authority to ultimately govern Gaza, claiming the group also calls for Israel's destruction. Meanwhile, in Paris, French authorities are looking into whether terrorism was to blame for a knife and hammer attack on tourists near the Eiffel Tower, leaving a German man dead and two others injured. A 26-year-old French national has been arrested. Let's turn now to Trey Yingst in southern Israel with the very latest on the war in Gaza. After a week-long ceasefire saw more than 100 hostages freed from Gaza, fighting has resumed for a third day. Israeli officials say the ground and air campaign in the second phase of this war against the strip could last for months. New airstrikes overnight targeted tunnel shafts and weapon storage facilities.
Coupled Multiwavelet Neural Operator Learning for Coupled Partial Differential Equations
Xiao, Xiongye, Cao, Defu, Yang, Ruochen, Gupta, Gaurav, Liu, Gengshuo, Yin, Chenzhong, Balan, Radu, Bogdan, Paul
Coupled partial differential equations (PDEs) are key tasks in modeling the complex dynamics of many physical processes. Recently, neural operators have shown the ability to solve PDEs by learning the integral kernel directly in Fourier/Wavelet space, so the difficulty for solving the coupled PDEs depends on dealing with the coupled mappings between the functions. Towards this end, we propose a coupled multiwavelets neural operator (CMWNO) learning scheme by decoupling the coupled integral kernels during the multiwavelet decomposition and reconstruction procedures in the Wavelet space. The proposed model achieves significantly higher accuracy compared to previous learning-based solvers in solving the coupled PDEs including Gray-Scott (GS) equations and the non-local mean field game (MFG) problem. According to our experimental results, the proposed model exhibits a 2ˆ 4ˆ improvement relative L2 error compared to the best results from the state-of-the-art models. Human perception relies on detecting and processing waves. While our eyes detect waves of electromagnetic radiation, our ears detect waves of compression in the surrounding air.
Adaptive Dependency Learning Graph Neural Networks
Sriramulu, Abishek, Fourrier, Nicolas, Bergmeir, Christoph
Graph Neural Networks (GNN) have recently gained popularity in the forecasting domain due to their ability to model complex spatial and temporal patterns in tasks such as traffic forecasting and region-based demand forecasting. Most of these methods require a predefined graph as input, whereas in real-life multivariate time series problems, a well-predefined dependency graph rarely exists. This requirement makes it harder for GNNs to be utilised widely for multivariate forecasting problems in other domains such as retail or energy. In this paper, we propose a hybrid approach combining neural networks and statistical structure learning models to self-learn the dependencies and construct a dynamically changing dependency graph from multivariate data aiming to enable the use of GNNs for multivariate forecasting even when a well-defined graph does not exist. The statistical structure modeling in conjunction with neural networks provides a well-principled and efficient approach by bringing in causal semantics to determine dependencies among the series. Finally, we demonstrate significantly improved performance using our proposed approach on real-world benchmark datasets without a pre-defined dependency graph.
Interpretable Mechanistic Representations for Meal-level Glycemic Control in the Wild
Wang, Ke Alexander, Fox, Emily B.
Diabetes encompasses a complex landscape of glycemic control that varies widely among individuals. However, current methods do not faithfully capture this variability at the meal level. On the one hand, expert-crafted features lack the flexibility of data-driven methods; on the other hand, learned representations tend to be uninterpretable which hampers clinical adoption. In this paper, we propose a hybrid variational autoencoder to learn interpretable representations of CGM and meal data. Our method grounds the latent space to the inputs of a mechanistic differential equation, producing embeddings that reflect physiological quantities, such as insulin sensitivity, glucose effectiveness, and basal glucose levels. Moreover, we introduce a novel method to infer the glucose appearance rate, making the mechanistic model robust to unreliable meal logs. On a dataset of CGM and self-reported meals from individuals with type-2 diabetes and pre-diabetes, our unsupervised representation discovers a separation between individuals proportional to their disease severity. Our embeddings produce clusters that are up to 4x better than naive, expert, black-box, and pure mechanistic features. Our method provides a nuanced, yet interpretable, embedding space to compare glycemic control within and across individuals, directly learnable from in-the-wild data.
Evaluating eVTOL Network Performance and Fleet Dynamics through Simulation-Based Analysis
Onat, Emin Burak, Bulusu, Vishwanath, Chakrabarty, Anjan, Hansen, Mark, Sengupta, Raja, Sridar, Banavar
Urban Air Mobility (UAM) represents a promising solution for future transportation. In this study, we introduce VertiSim, an advanced event-driven simulator developed to evaluate e-VTOL transportation networks. Uniquely, VertiSim simultaneously models passenger, aircraft, and energy flows, reflecting the interrelated complexities of UAM systems. We utilized VertiSim to assess 19 operational scenarios serving a daily demand for 2,834 passengers with varying fleet sizes and vertiport distances. The study aims to support stakeholders in making informed decisions about fleet size, network design, and infrastructure development by understanding tradeoffs in passenger delay time, operational costs, and fleet utilization. Our simulations, guided by a heuristic dispatch and charge policy, indicate that fleet size significantly influences passenger delay and energy consumption within UAM networks. We find that increasing the fleet size can reduce average passenger delays, but this comes at the cost of higher operational expenses due to an increase in the number of repositioning flights. Additionally, our analysis highlights how vertiport distances impact fleet utilization: longer distances result in reduced total idle time and increased cruise and charge times, leading to more efficient fleet utilization but also longer passenger delays. These findings are important for UAM network planning, especially in balancing fleet size with vertiport capacity and operational costs. Simulator demo is available at: https://tinyurl.com/vertisim-vis
DRAFT: Dense Retrieval Augmented Few-shot Topic classifier Framework
With the growing volume of diverse information, the demand for classifying arbitrary topics has become increasingly critical. To address this challenge, we introduce DRAFT, a simple framework designed to train a classifier for few-shot topic classification. DRAFT uses a few examples of a specific topic as queries to construct Customized dataset with a dense retriever model. Multi-query retrieval (MQR) algorithm, which effectively handles multiple queries related to a specific topic, is applied to construct the Customized dataset. Subsequently, we fine-tune a classifier using the Customized dataset to identify the topic. To demonstrate the efficacy of our proposed approach, we conduct evaluations on both widely used classification benchmark datasets and manually constructed datasets with 291 diverse topics, which simulate diverse contents encountered in real-world applications. DRAFT shows competitive or superior performance compared to baselines that use in-context learning, such as GPT-3 175B and InstructGPT 175B, on few-shot topic classification tasks despite having 177 times fewer parameters, demonstrating its effectiveness.
Kunyu: A High-Performing Global Weather Model Beyond Regression Losses
Over the past year, data-driven global weather forecasting has emerged as a new alternative to traditional numerical weather prediction. This innovative approach yields forecasts of comparable accuracy at a tiny fraction of computational costs. Regrettably, as far as I know, existing models exclusively rely on regression losses, producing forecasts with substantial blurring. Such blurring, although compromises practicality, enjoys an unfair advantage on evaluation metrics. In this paper, I present Kunyu, a global data-driven weather forecasting model which delivers accurate predictions across a comprehensive array of atmospheric variables at 0.35{\deg} resolution. With both regression and adversarial losses integrated in its training framework, Kunyu generates forecasts with enhanced clarity and realism. Its performance outpaces even ECMWF HRES in some aspects such as the estimation of anomaly extremes, while remaining competitive with ECMWF HRES on evaluation metrics such as RMSE and ACC. Kunyu is an important step forward in closing the utility gap between numerical and data-driven weather prediction.
Generative Powers of Ten
Wang, Xiaojuan, Kontkanen, Janne, Curless, Brian, Seitz, Steve, Kemelmacher, Ira, Mildenhall, Ben, Srinivasan, Pratul, Verbin, Dor, Holynski, Aleksander
We present a method that uses a text-to-image model to generate consistent content across multiple image scales, enabling extreme semantic zooms into a scene, e.g., ranging from a wide-angle landscape view of a forest to a macro shot of an insect sitting on one of the tree branches. We achieve this through a joint multi-scale diffusion sampling approach that encourages consistency across different scales while preserving the integrity of each individual sampling process. Since each generated scale is guided by a different text prompt, our method enables deeper levels of zoom than traditional super-resolution methods that may struggle to create new contextual structure at vastly different scales. We compare our method qualitatively with alternative techniques in image super-resolution and outpainting, and show that our method is most effective at generating consistent multi-scale content.