Energy
Latent Linear Quadratic Regulator for Robotic Control Tasks
Zhang, Yuan, Yang, Shaohui, Ohtsuka, Toshiyuki, Jones, Colin, Boedecker, Joschka
Model predictive control (MPC) has played a more crucial role in various robotic control tasks, but its high computational requirements are concerning, especially for nonlinear dynamical models. This paper presents a $\textbf{la}$tent $\textbf{l}$inear $\textbf{q}$uadratic $\textbf{r}$egulator (LaLQR) that maps the state space into a latent space, on which the dynamical model is linear and the cost function is quadratic, allowing the efficient application of LQR. We jointly learn this alternative system by imitating the original MPC. Experiments show LaLQR's superior efficiency and generalization compared to other baselines.
Transformer-based Drum-level Prediction in a Boiler Plant with Delayed Relations among Multivariates
Su, Gang, Yang, Sun, Li, Zhishuai
Abstract--The steam drum water level is a critical parameter that directly impacts the safety and efficiency of power plant operations. There is usually physical information behind the complex interrelations: for I. Proper control of drum level is essential for B's outlet are shared via a same parent pipe; thus, their ensuring continuous steam production while adhering to safety outlet pressures are always in the same trend. However, achieving precise control of drum level to understand all the variables causal interrelation is critical to is a challenging task due to various process disturbances and predict the final drum level. Traditionally, control Moreover, given the long reaction chain, for example, strategies for drum level regulation have relied on feedback increasing pump A's inlet flow will take a long delay to be and feedforward control techniques, often employing Proportional reflected in the increasing drum level (usually the delay will Integral Derivative (PID [1]) controllers in conjunction be around 100 seconds and it varies to different variables and with rule-based feedforward controllers. While these strategies different boiler plant), so when predicting, pump A's inlet flow have been effective to some extent, they often struggle to at time step t should be used to predict the drum level at time adapt to changing operating conditions and fail to capture the step t + t In recent years, there has been a growing interest in In this study, we aim to develop a data-driven model leveraging advanced deep-learning techniques to predict the based on Transformer architecture for predicting drum level future drum level, which enhances the PID via feedforward variations in steam boilers.
Differentiable Neural-Integrated Meshfree Method for Forward and Inverse Modeling of Finite Strain Hyperelasticity
Du, Honghui, Guo, Binyao, He, QiZhi
The present study aims to extend the novel physics-informed machine learning approach, specifically the neural-integrated meshfree (NIM) method, to model finite-strain problems characterized by nonlinear elasticity and large deformations. To this end, the hyperelastic material models are integrated into the loss function of the NIM method by employing a consistent local variational formulation. Thanks to the inherent differentiable programming capabilities, NIM can circumvent the need for derivation of Newton-Raphson linearization of the variational form and the resulting tangent stiffness matrix, typically required in traditional numerical methods. Additionally, NIM utilizes a hybrid neural-numerical approximation encoded with partition-of-unity basis functions, coined NeuroPU, to effectively represent the displacement and streamline the training process. NeuroPU can also be used for approximating the unknown material fields, enabling NIM a unified framework for both forward and inverse modeling. For the imposition of displacement boundary conditions, this study introduces a new approach based on singular kernel functions into the NeuroPU approximation, leveraging its unique feature that allows for customized basis functions. Numerical experiments demonstrate the NIM method's capability in forward hyperelasticity modeling, achieving desirable accuracy, with errors among $10^{-3} \sim 10^{-5}$ in the relative $L_2$ norm, comparable to the well-established finite element solvers. Furthermore, NIM is applied to address the complex task of identifying heterogeneous mechanical properties of hyperelastic materials from strain data, validating its effectiveness in the inverse modeling of nonlinear materials. To leverage GPU acceleration, NIM is fully implemented on the JAX deep learning framework in this study, utilizing the accelerator-oriented array computation capabilities offered by JAX.
Separable Operator Networks
Yu, Xinling, Hooten, Sean, Liu, Ziyue, Zhao, Yequan, Fiorentino, Marco, Van Vaerenbergh, Thomas, Zhang, Zheng
Operator learning has become a powerful tool in machine learning for modeling complex physical systems. Although Deep Operator Networks (DeepONet) show promise, they require extensive data acquisition. Physics-informed DeepONets (PI-DeepONet) mitigate data scarcity but suffer from inefficient training processes. We introduce Separable Operator Networks (SepONet), a novel framework that significantly enhances the efficiency of physics-informed operator learning. SepONet uses independent trunk networks to learn basis functions separately for different coordinate axes, enabling faster and more memory-efficient training via forward-mode automatic differentiation. We provide theoretical guarantees for SepONet using the universal approximation theorem and validate its performance through comprehensive benchmarking against PI-DeepONet. Our results demonstrate that for the 1D time-dependent advection equation, when targeting a mean relative $\ell_{2}$ error of less than 6% on 100 unseen variable coefficients, SepONet provides up to $112 \times$ training speed-up and $82 \times$ GPU memory usage reduction compared to PI-DeepONet. Similar computational advantages are observed across various partial differential equations, with SepONet's efficiency gains scaling favorably as problem complexity increases. This work paves the way for extreme-scale learning of continuous mappings between infinite-dimensional function spaces.
Enhancing Multi-Step Brent Oil Price Forecasting with Ensemble Multi-Scenario Bi-GRU Networks
Alruqimi, Mohammed, Di Persio, Luca
However, the prediction of crude oil prices is renowned for its obscurity and complexity. The high degree of volatility, unpredictable, irregular events, and complex interconnections among market factors make it extremely challenging to accurately forecast the fluctuations in crude oil prices. The dynamic interplay of supply and demand and changes in oil prices are influenced by external factors such as economic growth, financial markets, geopolitical conflicts, warfare, and political considerations [1, 2, 3]. A variety of methodologies have been utilised for predicting crude oil prices, involving the application of econometric and statistical time series analysis techniques such as VAR [4], ARIMA, GARCH [5], VMD [6], and Walvet decomposition [7]. In more recent studies, there has been a prevalent use of machine learning models and hybrid approaches [2, 8, 9] in the literature. Nevertheless, achieving accurate oil price forecasting remains a challenging task, particularly in terms of multi-step forecasting. Traditional econometric and statistical methods are often inadequate for forecasting oil prices due to many challenges related to the irregular characteristics of energy markets, such as non-stationarity, multi-frequency, non-linearity, and chaotic properties [10].
Enhancing Multistep Brent Oil Price Forecasting with a Multi-Aspect Metaheuristic Optimization Approach and Ensemble Deep Learning Models
Alruqimi, Mohammed, Di Persio, Luca
Accurate crude oil price forecasting is crucial for various economic activities, including energy trading, risk management, and investment planning. Although deep learning models have emerged as powerful tools for crude oil price forecasting, achieving accurate forecasts remains challenging. Deep learning models' performance is heavily influenced by hyperparameters tuning, and they are expected to perform differently under various circumstances. Furthermore, price volatility is also sensitive to external factors such as world events. To address these limitations, we propose a hybrid approach combining metaheuristic optimisation and an ensemble of five popular neural network architectures used in time series forecasting. Unlike existing methods that apply metaheuristics to optimise hyperparameters within the neural network architecture, we exploit the GWO metaheuristic optimiser at four levels: feature selection, data preparation, model training, and forecast blending. The proposed approach has been evaluated for forecasting three-ahead days using real-world Brent crude oil price data, and the obtained results demonstrate that the proposed approach improves the forecasting performance measured using various benchmarks, achieving 0.000127 of MSE.
iHuman: Instant Animatable Digital Humans From Monocular Videos
Paudel, Pramish, Khanal, Anubhav, Chhatkuli, Ajad, Paudel, Danda Pani, Tandukar, Jyoti
Personalized 3D avatars require an animatable representation of digital humans. Doing so instantly from monocular videos offers scalability to broad class of users and wide-scale applications. In this paper, we present a fast, simple, yet effective method for creating animatable 3D digital humans from monocular videos. Our method utilizes the efficiency of Gaussian splatting to model both 3D geometry and appearance. However, we observed that naively optimizing Gaussian splats results in inaccurate geometry, thereby leading to poor animations. This work achieves and illustrates the need of accurate 3D mesh-type modelling of the human body for animatable digitization through Gaussian splats. This is achieved by developing a novel pipeline that benefits from three key aspects: (a) implicit modelling of surface's displacements and the color's spherical harmonics; (b) binding of 3D Gaussians to the respective triangular faces of the body template; (c) a novel technique to render normals followed by their auxiliary supervision. Our exhaustive experiments on three different benchmark datasets demonstrates the state-of-the-art results of our method, in limited time settings. In fact, our method is faster by an order of magnitude (in terms of training time) than its closest competitor. At the same time, we achieve superior rendering and 3D reconstruction performance under the change of poses.
Q-Sparse: All Large Language Models can be Fully Sparsely-Activated
Wang, Hongyu, Ma, Shuming, Wang, Ruiping, Wei, Furu
We introduce, Q-Sparse, a simple yet effective approach to training sparsely-activated large language models (LLMs). Q-Sparse enables full sparsity of activations in LLMs which can bring significant efficiency gains in inference. This is achieved by applying top-K sparsification to the activations and the straight-through-estimator to the training. The key results from this work are, (1) Q-Sparse can achieve results comparable to those of baseline LLMs while being much more efficient at inference time; (2) We present an inference-optimal scaling law for sparsely-activated LLMs; (3) Q-Sparse is effective in different settings, including training-from-scratch, continue-training of off-the-shelf LLMs, and finetuning; (4) Q-Sparse works for both full-precision and 1-bit LLMs (e.g., BitNet b1.58). Particularly, the synergy of BitNet b1.58 and Q-Sparse (can be equipped with MoE) provides the cornerstone and a clear path to revolutionize the efficiency, including cost and energy consumption, of future LLMs.
Leveraging Hybrid Intelligence Towards Sustainable and Energy-Efficient Machine Learning
Geissler, Daniel, Lukowicz, Paul
Hybrid intelligence aims to enhance decision-making, problem-solving, and overall system performance by combining the strengths of both, human cognitive abilities and artificial intelligence. With the rise of Large Language Models (LLM), progressively participating as smart agents to accelerate machine learning development, Hybrid Intelligence is becoming an increasingly important topic for effective interaction between humans and machines. This paper presents an approach to leverage Hybrid Intelligence towards sustainable and energy-aware machine learning. When developing machine learning models, final model performance commonly rules the optimization process while the efficiency of the process itself is often neglected. Moreover, in recent times, energy efficiency has become equally crucial due to the significant environmental impact of complex and large-scale computational processes. The contribution of this work covers the interactive inclusion of secondary knowledge sources through Human-in-the-loop (HITL) and LLM agents to stress out and further resolve inefficiencies in the machine learning development process.
Optical Diffusion Models for Image Generation
Oguz, Ilker, Dinc, Niyazi Ulas, Yildirim, Mustafa, Ke, Junjie, Yoo, Innfarn, Wang, Qifei, Yang, Feng, Moser, Christophe, Psaltis, Demetri
Diffusion models generate new samples by progressively decreasing the noise from the initially provided random distribution. This inference procedure generally utilizes a trained neural network numerous times to obtain the final output, creating significant latency and energy consumption on digital electronic hardware such as GPUs. In this study, we demonstrate that the propagation of a light beam through a semi-transparent medium can be programmed to implement a denoising diffusion model on image samples. This framework projects noisy image patterns through passive diffractive optical layers, which collectively only transmit the predicted noise term in the image. The optical transparent layers, which are trained with an online training approach, backpropagating the error to the analytical model of the system, are passive and kept the same across different steps of denoising. Hence this method enables high-speed image generation with minimal power consumption, benefiting from the bandwidth and energy efficiency of optical information processing.