Machine Learning-Based Uncertainty Quantification and Design Optimization for Offset Compensation Sense Amplifiers in DRAMs

Aim: The majority of machine learning (ML) models in healthcare are built on retrospective data, much of which is collected without explicit patient consent for use in artificial intelligence (AI) and ML applications. The primary aim of this study was to evaluate whether clinicians and scientific researchers themselves consent to provide their own data for the training of ML models. Materials and Methods: This survey was conducted through an anonymous online survey, utilizing platforms such as Telegram, LinkedIn, and Viber. The target audience comprised specific international groups, primarily Russian, German, and English-speaking, of clinicians and scientific researchers. These participants ranged in their levels of expertise and experience, from beginners to veterans. The survey centered on a singular, pivotal question: “Do You Consent to the Use of Your Biological and Private Data for Training Machine Learning and AI Models?” Respondents had the option to choose from three responses: “Yes” and “No”. Results: The survey was conducted in January 2024. A total of 119 unique and verified individuals participated in the survey. The results revealed that only 50% of respondents (63 persons) expressed consent to provide their own data for the training of ML and AI models. Conclusion: In the development of ML and AI models, particularly open-source ones, it is crucial to ascertain whether participants are willing to provide their private data. While ML algorithms can transform the nature of data, it is important to remember that the primary owner of this data is the individual. Our findings show that in 50% of the cases, even participants from scientific research and clinical backgrounds – individuals typically accountable for ensuring data quality in AI and ML model development – do not consent to the use of their data in AI and ML settings. This highlights the need for more stringent consent processes and ethical considerations in the utilization of personal data in AI and ML research.

Shear viscosity, though being a fundamental property of all fluids, is computationally expensive to calculate from equilibrium molecular dynamics simulations. Recently, machine learning (ML) methods have been used to augment molecular simulations in many contexts, thus showing promise to estimate viscosity too in a relatively inexpensive manner. However, ML methods face significant challenges—such as overfitting, when the size of the data set is small, as is the case with viscosity. In this work, we train seven ML models to predict the shear viscosity of a Lennard–Jones fluid, with particular emphasis on addressing issues arising from a small data set. Specifically, the issues related to model selection, performance estimation and uncertainty quantification were investigated. First, we show that the widely used performance estimation procedure of using a single unseen data set shows a wide variability—in estimating the errors on—small data sets. In this context, the common practice of using cross validation (CV) to select the hyperparameters (model selection) can be adapted to estimate the generalization error (performance estimation) as well. We compare two simple CV procedures for their ability to do both model selection and performance estimation, and find that k-fold CV based procedure shows a lower variance of error estimates. Also, these CV procedures naturally lead to an ensemble of trained ML models. We discuss the role of performance metrics in training and evaluation and propose a method to rank the ML models based on multiple metrics. Finally, two methods for uncertainty quantification—Gaussian process regression (GPR) and ensemble method—were used to estimate the uncertainty on individual predictions. The uncertainty estimates from GPR were also used to construct an applicability domain using which the ML models provided even more reliable predictions on an independent viscosity data set generated in this work. Overall, the procedures prescribed in this work, together, lead to robust ML models for small data sets.

Batteries, recognized as effective energy storage solutions, are considered the main facilitators of the world-wide transition towards clean and renewable energy sources. Among different types of batteries, lithium-ion (Li-ion) variants offer higher energy densities and relatively longer life spans when compared to other types. Nonetheless, a primary concern with these batteries is their lifetime. Batteries undergo various degradation mechanisms under storage and use, significantly impacting their lifespan. To this end, it is crucial to predict the degradation and lifetime of Li-ion batteries under given conditions.Researchers use three main methodologies to perform battery health diagnostics and to predict the lifetime of batteries. One approach revolves around using mechanistic, first-principle electrochemical models, also known as physics-based models. If equipped with proper thermodynamic theories, such models can show promising capabilities; however, holistic degradation prediction with these models is still challenging due to the computational complexities and the multitude of parameters that need to be fine-tuned in this approach. The other common strategy is to use empirical models to predict battery degradation. These models generally entail fewer parameters to be identified and are computationally less intensive to solve. Nonetheless, empirical models can suffer from the accuracy point-of-view as they are constrained to predict degradation trends introduced by certain degradation modes. Another common technique in battery life prediction is to utilize purely data-driven methods, such as machine learning (ML) algorithms, which also have shown promising results in the literature on rapid health predictions. However, these methods require large volumes of experimental data for training and testing ML models to ensure accuracy. In addition, data-driven methods are likely to extrapolate poorly to conditions beyond their training data and are indifferent towards the underlying degradation mechanisms. Recently, physics-informed machine learning (PI-ML) methods have garnered significant attention. They integrate physics-based or empirical models (developed based on physics) with a data-driven approach and allow one to train ML models on a smaller set of experimental data.To the best of the authors’ knowledge, the performance comparison between first-principle and empirical models when integrated within PI-ML remains unclear. Therefore, in this work, we aim to compare these two models when applied to prognostics (capacity forecasting and remaining useful life prediction) of a set of Li-ion batteries. To perform this study, we generate aging data for 40 Li-ion coin cells cycled under randomized conditions. Each cell undergoes a three-step charging stage followed by a two-step discharge stage. After obtaining the aging data, we will develop two PI-ML models, one equipped with a physics-based model and another with a set of empirical models. Both PI-ML models in this work will follow the sequential integration approach, where the training data for the final PI-ML model come from both experimental and computational data, the latter of which are obtained from the physics-based or empirical models. The parameters for the physics-based and empirical models are identified from another set of experimental data. Finally, the PI-ML models will be tested with experimental data obtained at different cycling conditions. The data flow for the sequential architecture of PI-ML is shown in the attached figure. This comparative study will help identify the performance of physics-based and empirical models when integrated into PI-ML. The main performance metric considered in this work is each model’s ability to extrapolate beyond the experimental training data set, hence aiding the final PI-ML model in generalizing to conditions not covered by its experimental training data set. Figure 1

The future 6G network will be able to connect massive and various unmanned vehicles (UxVs) into the network, bringing novel requirements toward UxV network security and data privacy. Deploying machine learning (ML)-based intrusion detection on UxVs can be one promising approach. The conventional approach cannot fulfill security and privacy requirements, as the structure can be more flexible, and there may be a lack of a central node in the 6G-based UxV network. Moreover, UxV clients can exhibit high heterogeneity with extremely class-imbalanced training samples. With the presence of federated learning (FL), UxVs can collaborate to train and update ML models while preserving data privacy in the UxV security critical scenario. However, most past works focused on centralized approaches, using cloud servers to assist intrusion detection and service deployments. This article introduces an FL framework with a decentralized design for training ML models on UxVs using intrusion detection as a study case. This scheme can be more flexible, as UxV clients can collaborate to train and synchronize models without the central server. Simulation experiments were conducted to evaluate the efficiency of the proposed approach. Experimental results and theoretical analysis confirm that the proposed method outperforms baseline models with FedAvg and local-trained client models.

Dynamic Random-Access Memory (DRAM), as the core component of storage systems, offers a simple structure, high storage density, low unit cost, and fast read and write speeds. It is a key support for smart Internet of Things (IoT) devices to achieve low power consumption and high-density upgrades. Low-power, high-density DRAM technology has become a current research hotspot in the field of storage. In sense amplifiers, research focuses on offset compensation, noise immunity, and pre-sensing technology to improve accuracy under low-voltage operation and reduce power consumption. Using advanced Complementary Metal-Oxide-Semiconductor (CMOS) processes can reduce leakage current, lower operating voltage, and enhance process compatibility for high-density integration. 3D stacking technology breaks the physical limitations of planar DRAM through vertical integration that improves DRAM density and data retention capability. Starting from the above three major modules, this paper systematically reviews representative research achievements in low-power, high-density DRAM over the past few years. It analyzes the innovation paths and performance optimization effects of each module, and summarizes the development trends of low-power DRAM technology.

Empowered by promising artificial intelligence, the traditional Internet of Things is evolving into the Artificial Intelligence of Things (AIoT), which is an important enabling technology for Industry 4.0. Collaborative learning is a key technology for AIoT to build machine learning (ML) models on distributed datasets. However, there are two critical concerns of collaborative learning for AIoT: privacy leakage of sensitive data and dishonest computation. Specifically, data contains sensitive information of users, which cannot be openly shared for model learning. Furthermore, to protect the privacy of data or other selfish purposes, participants of collaborative learning may behave dishonestly, submitting dummy data or incorrect model computation. Therefore, it is important to guarantee privacy preservation of data and honest computation on collaborative learning. Our work tackles the two concerns wherein a model demander can securely train ML models with sensitive data and can regulate the computation of participants. To this end, we propose a secure and trusted collaborative learning framework called TrusCL. The framework guarantees privacy preservation via a delicate combination of homomorphic encryption (HE) and differential privacy (DP), achieving the trade-off between efficiency and accuracy. Furthermore, based on blockchain, in our design, the key steps of secure collaborative learning are recorded on blockchain so that malicious behaviors can be effectively tracked and choked in a timely manner to facilitate trusted computation. Experimental results validate the trade-off performance of Trus-CL between model training efficiency and trained model accuracy.

Surrogate-assisted hydraulic fracture optimization workflow with applications for shale gas reservoir development: a comparative study of machine learning models

Achieving operational excellence and efficiency is a constant goal in manufacturing and production, driven by the need to reduce waste and optimize processes in today’s competitive environment. The era of Industry 4.0 offers advanced technologies such as Artificial Intelligence (AI), robotics, IoT and cloud computing to support this pursuit, aligning with philosophies like lean manufacturing. However, modeling and optimizing complex production systems, which involve nonlinear behavior, interdependencies and time delays, remains a significant challenge. This research proposes a hybrid AI solution for optimizing production efficiency by combining Data Envelopment Analysis (DEA), Machine Learning (ML)-based simulation and Genetic Algorithms (GA). DEA is used to identify the efficient frontier of the production system based on historical or synthetic data. This data is used to train an ML model capable of simulating system behavior. GA is then applied to search for the optimal input configurations and control parameters to maximize efficiency, considering operational constraints. The methodology was applied and validated using real sensor data from a thermoelectric power plant. The process included data preparation with outlier removal using the Z-score method, calculation of relative efficiency using DEA-CCR, training ML models to predict outputs and efficiencies, and applying GA to identify ideal settings. The implementation resulted in significant improvements, with efficiency gains of 25% and 58% in two tested models, outperforming conventional closed-loop control systems. The approach also demonstrated that separating the optimization phase using GA from the DEA and ML training phases can significantly reduce computational time. As a result, the solution not only optimizes resource use and reduces production costs but also provides greater flexibility to production systems by reducing the direct dependency between high output levels and overall efficiency. The developed framework presents a practical, accessible and effective solution for production systems. It is adaptable to various industrial sectors and contributes to the data-driven digital transformation within the scope of Industry 4.0.

Streamflow predictions are essential for flood risk prevention and long-term water resource management. Extensive research has been dedicated to forecasting river discharge for gauged rivers, where discharge data is readily available. However, accurately predicting discharge in ungauged rivers continues to pose a substantial challenge. Recent advances in machine learning (ML) offer opportunities to develop and refine predictive models for ungauged rivers. This study addresses two key limitations of existing ML models: the exclusion of sensitive physical features and overconfidence in predictions. By integrating principles of mass conservation and robust uncertainty quantification (UQ) methods, we aim to enhance the reliability of ML-based streamflow forecasts. We propose a hybrid modeling approach that leverages insights from calibrated physics-based river-routing models, considers the causal effects of carefully selected features, and integrates UQ methods to obtain probabilistic discharge predictions in ungauged rivers. Three different UQ methods within the ML models are investigated. The results of a Colorado River upper basin demonstrate that our approach outperforms existing methods (i.e., purely data-driven method), reducing the prediction error by about 40% and offering credible uncertainty bounds for risk-informed decision making.

Reconstructing the emergence of the modern continental crust is crucial to understand the evolution of the crust, the onset of plate tectonics, elemental cycling, and long-term climate. However, it remains highly contentious about when and how the major subaerial continental crust emerged over time. Here, we used a machine learning (ML) model (XGBoost) to reveal the exposed history of continental crust over the last 3.8 billion years ago (Ga). First, we compiled ~10,000 modern subaerial or submarine basalts with major and trace elements to train the ML model. Then, the trained ML model (with resampling) was utilized to predict and calculate the mean proportions of subaerially erupted continental basaltic rocks since 3.8 Ga. The result suggested that the subaerial proportion only reached about 50% at ~2.5 Ga, indicating the exposure of the continental crust was far from the present-day level at the end of the Archean era. On the other hand, since ~1.8 Ga, the subaerial proportion of the continental crust exhibited a dynamic balance between ~60% and 80%, reaching the present-day level.

HADA: An automated tool for hardware dimensioning of AI applications

Federated learning enables privacy-preserving and data-efficient dimension prediction and part qualification across additive manufacturing factories

When establishing a safety case for a high-level nuclear waste repository, coupled thermal, hydraulic, mechanical and chemical (THMC) processes are modelled to assess radionuclide transport and the integrity of barriers. Modelling these processes requires numerous parameters, which are all subject to uncertainty. However, complex and extensive uncertainty quantification (UQ) methods can come at great computational cost, especially when performed on multi-parametric problems. Therefore, UQ methods are sought with manageable computational effort while still capturing the relevant information to allow a meaningful interpretation of the results. The aim of this study is the comparison of three different UQ methods with different levels of complexity and computational cost in terms of their results. Radionuclide transport and THM-calculations are performed by employing these methods to the French Callovo-Oxfordian claystone as a reference material. The three methods include: (1) a UQ method based on the complete sampling of input parameter distributions by a Monte Carlo approach, (2) a UQ method based on a minimal number of data points, by sampling quantiles of the input parameter distributions, as well as the bounds of the distributions’ intervals, and (3) a UQ method that involves a first-order second-moment reliability approach. The results depict the different limitations and benefits of the UQ methods analysed while highlighting that a comprehensive understanding of parameter sensitivity and modelling approach are key to choosing the appropriate UQ method. • Applicability of UQ methods depends on complexity of problem. • FOSM and quantile method can be appropriate for linear problems and non-coupled processes. • MC approach remains method of choice for complex non-linear analyses.

The burgeoning field of Machine Learning (ML) has revolutionized various aspects of our lives. However, the reliance on vast amounts of data, often containing personal information, raises concerns about individual privacy. Striking a balance between effective ML model training and protecting sensitive data is crucial for responsible development and ethical implementation. This paper explores the challenges and potential solutions for preserving privacy in ML training, focusing on differential privacy (DP). The advantages of implementing DP in ML training include robust protection of individual data, enabling meaningful insights from large datasets while maintaining privacy. This is essential for ethical and responsible data usage in machine learning applications. However, DP in ML training presents challenges including scalability issues and trade-offs between utility and privacy. The paper also covers the mathematical mechanisms of Laplace and Gaussian and their noise addition, followed by a comparative analysis of their efficiency within the dataset.

Enabled by a rich ecosystem of Machine Learning (ML) libraries, programming using learned models , i.e., Software-2.0 , has gained substantial adoption. However, we do not know what challenges developers encounter when they use ML libraries. With this knowledge gap, researchers miss opportunities to contribute to new research directions, tool builders do not invest resources where automation is most needed, library designers cannot make informed decisions when releasing ML library versions, and developers fail to use common practices when using ML libraries. We present the first large-scale quantitative and qualitative empirical study to shed light on how developers in Software-2.0 use ML libraries, and how this evolution affects their code. Particularly, using static analysis we perform a longitudinal study of 3,340 top-rated open-source projects with 46,110 contributors. To further understand the challenges of ML library evolution, we survey 109 developers who introduce and evolve ML libraries. Using this rich dataset we reveal several novel findings. Among others, we found an increasing trend of using ML libraries: The ratio of new Python projects that use ML libraries increased from 2% in 2013 to 50% in 2018. We identify several usage patterns including the following: (i) 36% of the projects use multiple ML libraries to implement various stages of the ML workflows, (ii) developers update ML libraries more often than the traditional libraries , (iii) strict upgrades are the most popular for ML libraries among other update kinds, (iv) ML library updates often result in cascading library updates, and (v) ML libraries are often downgraded (22.04% of cases). We also observed unique challenges when evolving and maintaining Software-2.0 such as (i) binary incompatibility of trained ML models and (ii) benchmarking ML models. Finally, we present actionable implications of our findings for researchers, tool builders, developers, educators, library vendors, and hardware vendors.