124 research outputs found
Representations of Materials for Machine Learning
High-throughput data generation methods and machine learning (ML) algorithms
have given rise to a new era of computational materials science by learning
relationships among composition, structure, and properties and by exploiting
such relations for design. However, to build these connections, materials data
must be translated into a numerical form, called a representation, that can be
processed by a machine learning model. Datasets in materials science vary in
format (ranging from images to spectra), size, and fidelity. Predictive models
vary in scope and property of interests. Here, we review context-dependent
strategies for constructing representations that enable the use of materials as
inputs or outputs of machine learning models. Furthermore, we discuss how
modern ML techniques can learn representations from data and transfer chemical
and physical information between tasks. Finally, we outline high-impact
questions that have not been fully resolved and thus, require further
investigation.Comment: 20 pages, 5 figures, To Appear in Annual Review of Materials Research
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Multi-task shape optimization using a 3D point cloud autoencoder as unified representation
Algorithms and the Foundations of Software technolog
Computation in Complex Networks
Complex networks are one of the most challenging research focuses of disciplines, including physics, mathematics, biology, medicine, engineering, and computer science, among others. The interest in complex networks is increasingly growing, due to their ability to model several daily life systems, such as technology networks, the Internet, and communication, chemical, neural, social, political and financial networks. The Special Issue “Computation in Complex Networks" of Entropy offers a multidisciplinary view on how some complex systems behave, providing a collection of original and high-quality papers within the research fields of: • Community detection • Complex network modelling • Complex network analysis • Node classification • Information spreading and control • Network robustness • Social networks • Network medicin
Unveiling the frontiers of deep learning: innovations shaping diverse domains
Deep learning (DL) enables the development of computer models that are
capable of learning, visualizing, optimizing, refining, and predicting data. In
recent years, DL has been applied in a range of fields, including audio-visual
data processing, agriculture, transportation prediction, natural language,
biomedicine, disaster management, bioinformatics, drug design, genomics, face
recognition, and ecology. To explore the current state of deep learning, it is
necessary to investigate the latest developments and applications of deep
learning in these disciplines. However, the literature is lacking in exploring
the applications of deep learning in all potential sectors. This paper thus
extensively investigates the potential applications of deep learning across all
major fields of study as well as the associated benefits and challenges. As
evidenced in the literature, DL exhibits accuracy in prediction and analysis,
makes it a powerful computational tool, and has the ability to articulate
itself and optimize, making it effective in processing data with no prior
training. Given its independence from training data, deep learning necessitates
massive amounts of data for effective analysis and processing, much like data
volume. To handle the challenge of compiling huge amounts of medical,
scientific, healthcare, and environmental data for use in deep learning, gated
architectures like LSTMs and GRUs can be utilized. For multimodal learning,
shared neurons in the neural network for all activities and specialized neurons
for particular tasks are necessary.Comment: 64 pages, 3 figures, 3 table
SketchSeeker : Finding Similar Sketches
Searching is an important tool for managing and navigating the massive amounts of data available in today’s information age. While new searching methods have be-come increasingly popular and reliable in recent years, such as image-based searching, these methods are more limited than text-based means in that they don’t allow generic user input. Sketch-based searching is a method that allows users to draw generic search queries and return similar drawn images, giving more user control over their search content. In this thesis, we present Sketchseeker, a system for indexing and searching across a large number of sketches quickly based on their similarity. The system includes several stages. First, sketches are indexed according to efficient and compact sketch descriptors. Second, the query retrieval subsystem considers sketches based on shape and structure similarity. Finally, a trained support vector machine classifier provides semantic filtering, which is then combined with median filtering to return the ranked results. SketchSeeker was tested on a large set of sketches against existing sketch similarity metrics, and it shows significant improvements in both speed and accuracy when compared to existing known techniques. The focus of this thesis is to outline the general components of a sketch retrieval system to find near similar sketches in real time
MACHINE LEARNING AND SOFTWARE SOLUTIONS FOR DATA QUALITY ASSESSMENT IN CERN’S ATLAS EXPERIMENT
The Large Hadron Collider (LHC) is home to multiple particle physics experiments designed to verify the standard model and push our understanding of the universe to its limits. The ATLAS detector is one of the large general-purpose experiments that make use of the LHC and generates a significant amount of data as part of its regular operations. Prior to physics analysis, this data is cleaned through a data assessment process which involves significant operator resources. With the evolution of the field of machine learning and anomaly detection, there is great opportunity to upgrade the ATLAS Data Quality Monitoring Framework to include automated, machine learning based solutions to reduce operator requirements and improve data quality for physics analysis. This thesis provides an infrastructure, theoretical foundation and a unique machine learning approach to automate this process. It accomplishes this by combining 2 heavily documented algorithms (Autoencoders and DBScan) and organizing the dataset around geometric descriptor features. The results of this work are released as code and software solutions for the benefit of current and future data quality assessment, research, and collaborations in the ATLAS experiment
Learning-based generative representations for automotive design optimization
In automotive design optimizations, engineers intuitively look for suitable representations of CAE models that can be used across different optimization problems. Determining a suitable compact representation of 3D CAE models facilitates faster search and optimization of 3D designs. Therefore, to support novice designers in the automotive design process, we envision a cooperative design system (CDS) which learns the experience embedded in past optimization data and is able to provide assistance to the designer while performing an engineering design optimization task. The research in this thesis addresses different aspects that can be combined to form a CDS framework.
First, based on the survey of deep learning techniques, a point cloud variational autoencoder (PC-VAE) is adapted from the literature, extended and evaluated as a shape generative model in design optimizations. The performance of the PC-VAE is verified with respect to state-of-the-art architectures. The PC-VAE is capable of generating a continuous low-dimensional search space for 3D designs, which further supports the generation of novel realistic 3D designs through interpolation and sampling in the latent space. In general, while designing a 3D car design, engineers need to consider multiple structural or functional performance criteria of a 3D design. Hence, in the second step, the latent representations of the PC-VAE are evaluated for generating novel designs satisfying multiple criteria and user preferences. A seeding method is proposed to provide a warm start to the optimization process and improve convergence time. Further, to replace expensive simulations for performance estimation in an optimization task, surrogate models are trained to map each latent representation of an input 3D design to their respective geometric and functional performance measures. However, the performance of the PC-VAE is less consistent due to additional regularization of the latent space.
Thirdly, to better understand which distinct region of the input 3D design is learned by a particular latent variable of the PC-VAE, a new deep generative model is proposed (Split-AE), which is an extension of the existing autoencoder architecture. The Split-AE learns input 3D point cloud representations and generates two sets of latent variables for each 3D design. The first set of latent variables, referred to as content, which helps to represent an overall underlying structure of the 3D shape to discriminate across other semantic shape categories. The second set of latent variables refers to the style, which represents the unique shape part of the input 3D shape and this allows grouping of shapes into shape classes. The reconstruction and latent variables disentanglement properties of the Split-AE are compared with other state-of-the-art architectures. In a series of experiments, it is shown that for given input shapes, the Split-AE is capable of generating the content and style variables which gives the flexibility to transfer and combine style features between different shapes. Thus, the Split-AE is able to disentangle features with minimum supervision and helps in generating novel shapes that are modified versions of the existing designs.
Lastly, to demonstrate the application of our initial envisioned CDS, two interactive systems were developed to assist designers in exploring design ideas. In the first CDS framework, the latent variables of the PC-VAE are integrated with a graphical user interface. This framework enables the designer to explore designs taking into account the data-driven knowledge and different performance measures of 3D designs. The second interactive system aims to guide the designers to achieve their design targets, for which past human experiences of performing 3D design modifications are captured and learned using a machine learning model. The trained model is then used to guide the (novice) engineers and designers by predicting the next step of design modification based on the current applied changes
Graph signal processing for machine learning: A review and new perspectives
The effective representation, processing, analysis, and visualization of
large-scale structured data, especially those related to complex domains such
as networks and graphs, are one of the key questions in modern machine
learning. Graph signal processing (GSP), a vibrant branch of signal processing
models and algorithms that aims at handling data supported on graphs, opens new
paths of research to address this challenge. In this article, we review a few
important contributions made by GSP concepts and tools, such as graph filters
and transforms, to the development of novel machine learning algorithms. In
particular, our discussion focuses on the following three aspects: exploiting
data structure and relational priors, improving data and computational
efficiency, and enhancing model interpretability. Furthermore, we provide new
perspectives on future development of GSP techniques that may serve as a bridge
between applied mathematics and signal processing on one side, and machine
learning and network science on the other. Cross-fertilization across these
different disciplines may help unlock the numerous challenges of complex data
analysis in the modern age
Advancing Wound Filling Extraction on 3D Faces: A Auto-Segmentation and Wound Face Regeneration Approach
Facial wound segmentation plays a crucial role in preoperative planning and
optimizing patient outcomes in various medical applications. In this paper, we
propose an efficient approach for automating 3D facial wound segmentation using
a two-stream graph convolutional network. Our method leverages the Cir3D-FaIR
dataset and addresses the challenge of data imbalance through extensive
experimentation with different loss functions. To achieve accurate
segmentation, we conducted thorough experiments and selected a high-performing
model from the trained models. The selected model demonstrates exceptional
segmentation performance for complex 3D facial wounds. Furthermore, based on
the segmentation model, we propose an improved approach for extracting 3D
facial wound fillers and compare it to the results of the previous study. Our
method achieved a remarkable accuracy of 0.9999986\% on the test suite,
surpassing the performance of the previous method. From this result, we use 3D
printing technology to illustrate the shape of the wound filling. The outcomes
of this study have significant implications for physicians involved in
preoperative planning and intervention design. By automating facial wound
segmentation and improving the accuracy of wound-filling extraction, our
approach can assist in carefully assessing and optimizing interventions,
leading to enhanced patient outcomes. Additionally, it contributes to advancing
facial reconstruction techniques by utilizing machine learning and 3D
bioprinting for printing skin tissue implants. Our source code is available at
\url{https://github.com/SIMOGroup/WoundFilling3D}
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