294 research outputs found
Machine learning in solar physics
The application of machine learning in solar physics has the potential to
greatly enhance our understanding of the complex processes that take place in
the atmosphere of the Sun. By using techniques such as deep learning, we are
now in the position to analyze large amounts of data from solar observations
and identify patterns and trends that may not have been apparent using
traditional methods. This can help us improve our understanding of explosive
events like solar flares, which can have a strong effect on the Earth
environment. Predicting hazardous events on Earth becomes crucial for our
technological society. Machine learning can also improve our understanding of
the inner workings of the sun itself by allowing us to go deeper into the data
and to propose more complex models to explain them. Additionally, the use of
machine learning can help to automate the analysis of solar data, reducing the
need for manual labor and increasing the efficiency of research in this field.Comment: 100 pages, 13 figures, 286 references, accepted for publication as a
Living Review in Solar Physics (LRSP
GBG++: A Fast and Stable Granular Ball Generation Method for Classification
Granular ball computing (GBC), as an efficient, robust, and scalable learning
method, has become a popular research topic of granular computing. GBC includes
two stages: granular ball generation (GBG) and multi-granularity learning based
on the granular ball (GB). However, the stability and efficiency of existing
GBG methods need to be further improved due to their strong dependence on
-means or -division. In addition, GB-based classifiers only unilaterally
consider the GB's geometric characteristics to construct classification rules,
but the GB's quality is ignored. Therefore, in this paper, based on the
attention mechanism, a fast and stable GBG (GBG++) method is proposed first.
Specifically, the proposed GBG++ method only needs to calculate the distances
from the data-driven center to the undivided samples when splitting each GB
instead of randomly selecting the center and calculating the distances between
it and all samples. Moreover, an outlier detection method is introduced to
identify local outliers. Consequently, the GBG++ method can significantly
improve effectiveness, robustness, and efficiency while being absolutely
stable. Second, considering the influence of the sample size within the GB on
the GB's quality, based on the GBG++ method, an improved GB-based -nearest
neighbors algorithm (GBNN++) is presented, which can reduce
misclassification at the class boundary. Finally, the experimental results
indicate that the proposed method outperforms several existing GB-based
classifiers and classical machine learning classifiers on public benchmark
datasets
Modelling tumbling ball milling based on DEM simulation and machine learning
Tumbling ball milling is a critical comminution process in materials and mineral processing industries. It is an energy intensive process with low energy efficiency. It is important that ball mills and the milling process are properly designed and operated. To achieve this, models at different scales are needed to provide accurate prediction of mill performance under various conditions.
This study aimed to develop a combined discrete element method (DEM) and machine learning (ML) modelling framework to link mill design, operation parameters with particle flow and mill efficiency. A scale-up model was developed based on DEM simulations to link mill size ratio, rotation rate, and filling level with power draw and grinding rate. Then, an ML model using the Support Vector Machine (SVM) algorithm was developed to predict the angle of repose (AoR) and collision energy based on various operation conditions. The ML model was trained by the data generated from the DEM simulations and able to predict the AoR and collision energy. In the process monitoring, an artificial neural network (ANN) was firstly proposed to predict internal particle flow properties of a rotating mill based on acoustic emission (AE) signal generated using the DEM. Main features of AE signals and power draw were fed into the ANN to predict flow properties such as particle size distributions, collision energy distribution and filling levels. Further, a convolution neural network (CNN) was used to replace the ANN to extract more efficient features of AE signals non-linearly based on different local frequency ranges in a ball milling process partially filled with steel balls and grinding particles. Last, a physics-informed ML model was developed based on continuous convolution neural network (CCNN) to learn particle contact mechanisms provided by DEM data at different rotation speeds. The ML model coupled with DEM simulation can accelerate DEM simulation to accurately predict particle flow in a long time series.
In summary, this work has demonstrated that combining physics-based numerical models DEM to ML models not only improves the efficiency and accuracy of predictions of complicated processes but also provides more insight to the process and makes predictions more transparent
Selected Papers from 2020 IEEE International Conference on High Voltage Engineering (ICHVE 2020)
The 2020 IEEE International Conference on High Voltage Engineering (ICHVE 2020) was held on 6–10 September 2020 in Beijing, China. The conference was organized by the Tsinghua University, China, and endorsed by the IEEE Dielectrics and Electrical Insulation Society. This conference has attracted a great deal of attention from researchers around the world in the field of high voltage engineering. The forum offered the opportunity to present the latest developments and different emerging challenges in high voltage engineering, including the topics of ultra-high voltage, smart grids, and insulating materials
Roles of Artificial Intelligence and Machine Learning in Enhancing Construction Processes and Sustainable Communities
Machine Learning (ML), a subset of Artificial Intelligence (AI), is gaining popularity in the architectural, engineering, and construction (AEC) sector. This systematic study aims to investigate the roles of AI and ML in improving construction processes and developing more sustainable communities. This study intends to determine the various roles played by AI and ML in the development of sustainable communities and construction practices via an in-depth assessment of the current literature. Furthermore, it intends to predict future research trends and practical applications of AI and ML in the built environment. Following the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines, this study highlights the roles that AI and ML technologies play in building sustainable communities, both indoors and out. In the interior environment, they contribute to energy management by optimizing energy usage, finding inefficiencies, and recommending modifications to minimize consumption. This contributes to reducing the environmental effect of energy generation. Similarly, AI and ML technologies aid in addressing environmental challenges. They can monitor air quality, noise levels, and waste management systems to quickly discover and minimize pollution sources. Likewise, AI and ML applications in construction processes enhance planning, scheduling, and facility management
Optimized EWT-Seq2Seq-LSTM with Attention Mechanism to Insulators Fault Prediction
Insulators installed outdoors are vulnerable to the accumulation of contaminants on their surface, which raise their conductivity and increase leakage current until a flashover occurs. To improve the reliability of the electrical power system, it is possible to evaluate the development of the fault in relation to the increase in leakage current and thus predict a shutdown might occur. This paper proposes the use of empirical wavelet transform (EWT) to reduce the influence of non-representative variations and combines the attention mechanism with long short-term memory (LSTM) recurrent network for prediction. The Optuna framework has been applied for hyperparameter optimization, resulting in a method called Optimized EWT-Seq2Seq-LSTM with Attention. The proposed model had a 10.17% lower mean square error (MSE) than the standard LSTM and a 5.36% lower MSE than the model without optimization, showing that the attention mechanism and hyperparameter optimization is a promising strategy
Multifunctional photoacoustic materials for neural engineering
Understanding the complex information transfer process of our nervous system is one of the most urgent needs in the biomedical community. Neuromodulation is a technique that can artificially influence or modulate the activity of the target neurons. It's an inevitable tool in both the neuroscience study but also the clinical treatment of neurological diseases. The conventional method for neural modulation is the electrical stimulation using implantable electrodes. However, its intrinsic current leakage problem is an obstacle for further improving its performance in clinical scenarios because of the finite spatial resolution and recording artifacts. In general, an ideal method should be able to modulate neural activities with a high spatial, temporal and functionality specificity but without biocompatibility and reliability issues even in long term.
Photoacoustic stimulation is an emerging light-mediated, non-genetic neural modulation method with high spatiotemporal resolution. Multiple devices have been designed in the past few years. But there are still several gaps to be filled to further expand its applications. One is the material mismatch, and another is that more function is needed, for example the capability of simultaneous recording. My research focused on the design and development of two new types of photoacoustic materials to expand the use of photoacoustic stimulation. A soft hydrogel film and a multifunctional fiber-based emitter for photoacoustic neuromodulation have been developed in my Ph.D. research. The study on these materials increased our knowledge to photoacoustic neurostimulation, also help us to investigate the effect of photoacoustic neuromodulation in the treatment of neurological and neurodegenerative diseases
Advanced Eco-friendly Wood-Based Composites
In collaboration with the MDPI publishing house, we are pleased to introduce the reader to our new project, a Special Issue entitled “Advanced Eco-friendly Wood-Based Composites”. This Special Issue provides an opportunity to investigate advanced eco-friendly wood-based composites from a broader perspective. The coronavirus pandemic and shutdown measures employed to contain it, as well as the ongoing war in Ukraine, have influenced and decelerated the world economy and adversely impacted research activities on most levels in all countries. Surprisingly, researchers in the field of wood-based composites have continued to make progress, which is also described in this Special Issue
Content-aware approach for improving biomedical image analysis: an interdisciplinary study series
Biomedicine is a highly interdisciplinary research area at the interface of sciences, anatomy, physiology, and medicine. In the last decade, biomedical studies have been greatly enhanced by the introduction of new technologies and techniques for automated quantitative imaging, thus considerably advancing the possibility to investigate biological phenomena through image analysis. However, the effectiveness of this interdisciplinary approach is bounded by the limited knowledge that a biologist and a computer scientist, by professional training, have of each other’s fields. The possible solution to make up for both these lacks lies in training biologists to make them interdisciplinary researchers able to develop dedicated image processing and analysis tools by exploiting a content-aware approach.
The aim of this Thesis is to show the effectiveness of a content-aware approach to automated quantitative imaging, by its application to different biomedical studies, with the secondary desirable purpose of motivating researchers to invest in interdisciplinarity. Such content-aware approach has been applied firstly to the phenomization of tumour cell response to stress by confocal fluorescent imaging, and secondly, to the texture analysis of trabecular bone microarchitecture in micro-CT scans. Third, this approach served the characterization of new 3-D multicellular spheroids of human stem cells, and the investigation of the role of the Nogo-A protein in tooth innervation. Finally, the content-aware approach also prompted to the development of two novel methods for local image analysis and colocalization quantification.
In conclusion, the content-aware approach has proved its benefit through building new approaches that have improved the quality of image analysis, strengthening the statistical significance to allow unveiling biological phenomena. Hopefully, this Thesis will contribute to inspire researchers to striving hard for pursuing interdisciplinarity
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