Energy
Depth analysis of battery performance based on a data-driven approach
Zhang, Zhen, Sun, Hongrui, Sun, Hui
Capacity attenuation is one of the most intractable issues in the current of application of the cells. The disintegration mechanism is well known to be very complex across the system. It is a great challenge to fully comprehend this process and predict the process accurately. Thus, the machine learning (ML) technology is employed to predict the specific capacity change of the cell throughout the cycle and grasp this intricate procedure. Different from the previous work, according to the WOA-ELM model proposed in this work (R2 = 0.9999871), the key factors affecting the specific capacity of the battery are determined, and the defects in the machine learning black box are overcome by the interpretable model. Their connection with the structural damage of electrode materials and battery failure during battery cycling is comprehensively explained, revealing their essentiality to battery performance, which is conducive to superior research on contemporary batteries and modification.
Solving AC Power Flow with Graph Neural Networks under Realistic Constraints
Böttcher, Luis, Wolf, Hinrikus, Jung, Bastian, Lutat, Philipp, Trageser, Marc, Pohl, Oliver, Ulbig, Andreas, Grohe, Martin
In this paper, we propose a graph neural network architecture to solve the AC power flow problem under realistic constraints. To ensure a safe and resilient operation of distribution grids, AC power flow calculations are the means of choice to determine grid operating limits or analyze grid asset utilization in planning procedures. In our approach, we demonstrate the development of a framework that uses graph neural networks to learn the physical constraints of the power flow. We present our model architecture on which we perform unsupervised training to learn a general solution of the AC power flow formulation independent of the specific topologies and supply tasks used for training. Finally, we demonstrate, validate and discuss our results on medium voltage benchmark grids. In our approach, we focus on the physical and topological properties of distribution grids to provide scalable solutions for real grid topologies. Therefore, we take a data-driven approach, using large and diverse data sets consisting of realistic grid topologies, for the unsupervised training of the AC power flow graph neural network architecture and compare the results to a prior neural architecture and the Newton-Raphson method. Our approach shows a high increase in computation time and good accuracy compared to state-of-the-art solvers. It also out-performs that neural solver for power flow in terms of accuracy.
Quantifying Process Quality: The Role of Effective Organizational Learning in Software Evolution
Real-world software applications must constantly evolve to remain relevant. This evolution occurs when developing new applications or adapting existing ones to meet new requirements, make corrections, or incorporate future functionality. Traditional methods of software quality control involve software quality models and continuous code inspection tools. These measures focus on directly assessing the quality of the software. However, there is a strong correlation and causation between the quality of the development process and the resulting software product. Therefore, improving the development process indirectly improves the software product, too. To achieve this, effective learning from past processes is necessary, often embraced through post mortem organizational learning. While qualitative evaluation of large artifacts is common, smaller quantitative changes captured by application lifecycle management are often overlooked. In addition to software metrics, these smaller changes can reveal complex phenomena related to project culture and management. Leveraging these changes can help detect and address such complex issues. Software evolution was previously measured by the size of changes, but the lack of consensus on a reliable and versatile quantification method prevents its use as a dependable metric. Different size classifications fail to reliably describe the nature of evolution. While application lifecycle management data is rich, identifying which artifacts can model detrimental managerial practices remains uncertain. Approaches such as simulation modeling, discrete events simulation, or Bayesian networks have only limited ability to exploit continuous-time process models of such phenomena. Even worse, the accessibility and mechanistic insight into such gray- or black-box models are typically very low. To address these challenges, we suggest leveraging objectively [...]
A Bayesian Framework for Digital Twin-Based Control, Monitoring, and Data Collection in Wireless Systems
Ruah, Clement, Simeone, Osvaldo, Al-Hashimi, Bashir
Commonly adopted in the manufacturing and aerospace sectors, digital twin (DT) platforms are increasingly seen as a promising paradigm to control, monitor, and analyze software-based, "open", communication systems. Notably, DT platforms provide a sandbox in which to test artificial intelligence (AI) solutions for communication systems, potentially reducing the need to collect data and test algorithms in the field, i.e., on the physical twin (PT). A key challenge in the deployment of DT systems is to ensure that virtual control optimization, monitoring, and analysis at the DT are safe and reliable, avoiding incorrect decisions caused by "model exploitation". To address this challenge, this paper presents a general Bayesian framework with the aim of quantifying and accounting for model uncertainty at the DT that is caused by limitations in the amount and quality of data available at the DT from the PT. In the proposed framework, the DT builds a Bayesian model of the communication system, which is leveraged to enable core DT functionalities such as control via multi-agent reinforcement learning (MARL), monitoring of the PT for anomaly detection, prediction, data-collection optimization, and counterfactual analysis. To exemplify the application of the proposed framework, we specifically investigate a case-study system encompassing multiple sensing devices that report to a common receiver. Experimental results validate the effectiveness of the proposed Bayesian framework as compared to standard frequentist model-based solutions.
Learning robotic milling strategies based on passive variable operational space interaction control
Hathaway, Jamie, Rastegarpanah, Alireza, Stolkin, Rustam
Abstract--This paper addresses the problem of robotic cutting a milling task online without user assistance. We develop a during disassembly of products for materials separation and framework for controlling a robot using this strategy that allows recycling. Waste handling applications differ from milling in the stiffness of the robot arm to be modulated over time to best manufacturing processes, as they engender considerable variety satisfy metrics of productivity (e.g. To address this challenge, we propose (e.g. by avoiding force limits), similarly to how a human operator a learning-based approach incorporating elements of interaction can vary muscular tension to accomplish different tasks. We control, in which the robot can adapt key parameters, such posit that the proposed method can substitute a trial-and-error as feed rate, depth of cut, and mechanical compliance during strategy of selecting process parameters for disassembly of novel task execution. We show how a mathematical model of cutting products, or integrated with existing planning approaches to mechanics, embedded in a simulation environment, can be used adjust the parameters of milling tasks online. The simulation approach control, passivity-based control, energy tank was validated on a real robot setup based on four case study materials with varying structural and mechanical properties.
Ontologies in Digital Twins: A Systematic Literature Review
Karabulut, Erkan, Pileggi, Salvatore F., Groth, Paul, Degeler, Victoria
Digital Twins (DT) facilitate monitoring and reasoning processes in cyber-physical systems. They have progressively gained popularity over the past years because of intense research activity and industrial advancements. Cognitive Twins is a novel concept, recently coined to refer to the involvement of Semantic Web technology in DTs. Recent studies address the relevance of ontologies and knowledge graphs in the context of DTs, in terms of knowledge representation, interoperability and automatic reasoning. However, there is no comprehensive analysis of how semantic technologies, and specifically ontologies, are utilized within DTs. This Systematic Literature Review (SLR) is based on the analysis of 82 research articles, that either propose or benefit from ontologies with respect to DT. The paper uses different analysis perspectives, including a structural analysis based on a reference DT architecture, and an application-specific analysis to specifically address the different domains, such as Manufacturing and Infrastructure. The review also identifies open issues and possible research directions on the usage of ontologies and knowledge graphs in DTs.
The Future of Fundamental Science Led by Generative Closed-Loop Artificial Intelligence
Zenil, Hector, Tegnér, Jesper, Abrahão, Felipe S., Lavin, Alexander, Kumar, Vipin, Frey, Jeremy G., Weller, Adrian, Soldatova, Larisa, Bundy, Alan R., Jennings, Nicholas R., Takahashi, Koichi, Hunter, Lawrence, Dzeroski, Saso, Briggs, Andrew, Gregory, Frederick D., Gomes, Carla P., Rowe, Jon, Evans, James, Kitano, Hiroaki, King, Ross
Recent advances in machine learning and AI, including Generative AI and LLMs, are disrupting technological innovation, product development, and society as a whole. AI's contribution to technology can come from multiple approaches that require access to large training data sets and clear performance evaluation criteria, ranging from pattern recognition and classification to generative models. Yet, AI has contributed less to fundamental science in part because large data sets of high-quality data for scientific practice and model discovery are more difficult to access. Generative AI, in general, and Large Language Models in particular, may represent an opportunity to augment and accelerate the scientific discovery of fundamental deep science with quantitative models. Here we explore and investigate aspects of an AI-driven, automated, closed-loop approach to scientific discovery, including self-driven hypothesis generation and open-ended autonomous exploration of the hypothesis space. Integrating AI-driven automation into the practice of science would mitigate current problems, including the replication of findings, systematic production of data, and ultimately democratisation of the scientific process. Realising these possibilities requires a vision for augmented AI coupled with a diversity of AI approaches able to deal with fundamental aspects of causality analysis and model discovery while enabling unbiased search across the space of putative explanations. These advances hold the promise to unleash AI's potential for searching and discovering the fundamental structure of our world beyond what human scientists have been able to achieve. Such a vision would push the boundaries of new fundamental science rather than automatize current workflows and instead open doors for technological innovation to tackle some of the greatest challenges facing humanity today.
Combining predictive distributions of electricity prices: Does minimizing the CRPS lead to optimal decisions in day-ahead bidding?
In order to mitigate risks or increase profits from trading in day-ahead power markets, market participants use data-driven decision support techniques [12, 16, 17, 28]. For years, these have relied on point forecasts of the major variables of interest: loads (or demand for electricity), generation from renewable energy sources (RES), and electricity prices [10, 30]. However, as recently shown by Uniejewski and Weron [27], decisions based on probabilistic price forecasts, i.e., quantiles, prediction intervals or whole predictive distributions, can yield significantly higher profits. For the quantile-based bidding strategies considered in the Polish day-ahead power market, the profit obtained was from 5% to 19% higher than for the strategy based on point forecasts alone. Point forecasts are far more popular in the electricity price forecasting (EPF) literature, not only in a decision support context. As reported by Maciejowska et al. [18], probabilistic EPF was not part of the mainstream literature until the Global Energy Forecasting Competition in 2014 [9], and even now,
Fukushima wastewater has been released, but other challenges, like removing melted nuclear fuel, remain
Fox News Flash top headlines are here. Check out what's clicking on Foxnews.com. At a small section of the Fukushima Daiichi nuclear plant's central control room, the treated water transfer switch is on. A graph on a computer monitor nearby shows a steady decrease of water levels as treated radioactive wastewater is diluted and released into the Pacific Ocean. In the coastal area of the plant, two seawater pumps are in action, gushing torrents of seawater through sky blue pipes into the big header where the treated water, which comes down through a much thinner black pipe from the hilltop tanks, is diluted hundreds of times before the release.
Sufficient Invariant Learning for Distribution Shift
Kim, Taero, Lim, Sungjun, Song, Kyungwoo
Machine learning algorithms have shown remarkable performance in diverse applications. However, it is still challenging to guarantee performance in distribution shifts when distributions of training and test datasets are different. There have been several approaches to improve the performance in distribution shift cases by learning invariant features across groups or domains. However, we observe that the previous works only learn invariant features partially. While the prior works focus on the limited invariant features, we first raise the importance of the sufficient invariant features. Since only training sets are given empirically, the learned partial invariant features from training sets might not be present in the test sets under distribution shift. Therefore, the performance improvement on distribution shifts might be limited. In this paper, we argue that learning sufficient invariant features from the training set is crucial for the distribution shift case. Concretely, we newly observe the connection between a) sufficient invariant features and b) flatness differences between groups or domains. Moreover, we propose a new algorithm, Adaptive Sharpness-aware Group Distributionally Robust Optimization (ASGDRO), to learn sufficient invariant features across domains or groups. ASGDRO learns sufficient invariant features by seeking common flat minima across all groups or domains. Therefore, ASGDRO improves the performance on diverse distribution shift cases. Besides, we provide a new simple dataset, Heterogeneous-CMNIST, to diagnose whether the various algorithms learn sufficient invariant features.