Materials
TMoE-P: Towards the Pareto Optimum for Multivariate Soft Sensors
Pan, Licheng, Wang, Hao, Chen, Zhichao, Huang, Yuxing, Liu, Xinggao
Multi-variate soft sensor seeks accurate estimation of multiple quality variables using measurable process variables, which have emerged as a key factor in improving the quality of industrial manufacturing. The current progress stays in some direct applications of multitask network architectures; however, there are two fundamental issues remain yet to be investigated with these approaches: (1) negative transfer, where sharing representations despite the difference of discriminate representations for different objectives degrades performance; (2) seesaw phenomenon, where the optimizer focuses on one dominant yet simple objective at the expense of others. In this study, we reformulate the multi-variate soft sensor to a multi-objective problem, to address both issues and advance state-of-the-art performance. To handle the negative transfer issue, we first propose an Objective-aware Mixture-of-Experts (OMoE) module, utilizing objective-specific and objective-shared experts for parameter sharing while maintaining the distinction between objectives. To address the seesaw phenomenon, we then propose a Pareto Objective Routing (POR) module, adjusting the weights of learning objectives dynamically to achieve the Pareto optimum, with solid theoretical supports. We further present a Task-aware Mixture-of-Experts framework for achieving the Pareto optimum (TMoE-P) in multi-variate soft sensor, which consists of a stacked OMoE module and a POR module. We illustrate the efficacy of TMoE-P with an open soft sensor benchmark, where TMoE-P effectively alleviates the negative transfer and seesaw issues and outperforms the baseline models.
GAUCHE: A Library for Gaussian Processes in Chemistry
Griffiths, Ryan-Rhys, Klarner, Leo, Moss, Henry B., Ravuri, Aditya, Truong, Sang, Stanton, Samuel, Tom, Gary, Rankovic, Bojana, Du, Yuanqi, Jamasb, Arian, Deshwal, Aryan, Schwartz, Julius, Tripp, Austin, Kell, Gregory, Frieder, Simon, Bourached, Anthony, Chan, Alex, Moss, Jacob, Guo, Chengzhi, Durholt, Johannes, Chaurasia, Saudamini, Strieth-Kalthoff, Felix, Lee, Alpha A., Cheng, Bingqing, Aspuru-Guzik, Alán, Schwaller, Philippe, Tang, Jian
We introduce GAUCHE, a library for GAUssian processes in CHEmistry. Gaussian processes have long been a cornerstone of probabilistic machine learning, affording particular advantages for uncertainty quantification and Bayesian optimisation. Extending Gaussian processes to chemical representations, however, is nontrivial, necessitating kernels defined over structured inputs such as graphs, strings and bit vectors. By defining such kernels in GAUCHE, we seek to open the door to powerful tools for uncertainty quantification and Bayesian optimisation in chemistry. Motivated by scenarios frequently encountered in experimental chemistry, we showcase applications for GAUCHE in molecular discovery and chemical reaction optimisation. The codebase is made available at https://github.com/leojklarner/gauche
Machine learning for the prediction of safe and biologically active organophosphorus molecules
Hu, Hang, Ooi, Hsu Kiang, Ghaemi, Mohammad Sajjad, Hu, Anguang
Drug discovery is a complex process with a large molecular space to be considered. By constraining the search space, the fragment-based drug design is an approach that can effectively sample the chemical space of interest. Here we propose a framework of Recurrent Neural Networks (RNN) with an attention model to sample the chemical space of organophosphorus molecules using the fragment-based approach. The framework is trained with a ZINC dataset that is screened for high druglikeness scores. The goal is to predict molecules with similar biological action modes as organophosphorus pesticides or chemical warfare agents yet less toxic to humans. The generated molecules contain a starting fragment of PO2F but have a bulky hydrocarbon side chain limiting its binding effectiveness to the targeted protein.
A Statistically-Based Approach to Feedforward Neural Network Model Selection
McInerney, Andrew, Burke, Kevin
Feedforward neural networks (FNNs) can be viewed as non-linear regression models, where covariates enter the model through a combination of weighted summations and non-linear functions. Although these models have some similarities to the models typically used in statistical modelling, the majority of neural network research has been conducted outside of the field of statistics. This has resulted in a lack of statistically-based methodology, and, in particular, there has been little emphasis on model parsimony. Determining the input layer structure is analogous to variable selection, while the structure for the hidden layer relates to model complexity. In practice, neural network model selection is often carried out by comparing models using out-of-sample performance. However, in contrast, the construction of an associated likelihood function opens the door to information-criteria-based variable and architecture selection. A novel model selection method, which performs both input- and hidden-node selection, is proposed using the Bayesian information criterion (BIC) for FNNs. The choice of BIC over out-of-sample performance as the model selection objective function leads to an increased probability of recovering the true model, while parsimoniously achieving favourable out-of-sample performance. Simulation studies are used to evaluate and justify the proposed method, and applications on real data are investigated.
The Future of Mining: How Technology is Driving Increased Productivity - Isrg KB
Mining is an important sector in India, contributing to the country's economic growth. The Indian mining industry encompasses exploration, extraction, and processing of minerals and metallic and non-metallic minerals. With increasing demand for minerals, the mining industry in India has seen significant growth in recent years. In this report, we will analyze the current state of mining technology in India and its impact on the mining industry. The mining industry in India has made significant advancements in recent years, with the introduction of modern technology.
Rapid Design of Top-Performing Metal-Organic Frameworks with Qualitative Representations of Building Blocks
Comlek, Yigitcan, Pham, Thang Duc, Snurr, Randall, Chen, Wei
Data-driven materials design often encounters challenges where systems require or possess qualitative (categorical) information. Metal-organic frameworks (MOFs) are an example of such material systems. The representation of MOFs through different building blocks makes it a challenge for designers to incorporate qualitative information into design optimization. Furthermore, the large number of potential building blocks leads to a combinatorial challenge, with millions of possible MOFs that could be explored through time consuming physics-based approaches. In this work, we integrated Latent Variable Gaussian Process (LVGP) and Multi-Objective Batch-Bayesian Optimization (MOBBO) to identify top-performing MOFs adaptively, autonomously, and efficiently without any human intervention. Our approach provides three main advantages: (i) no specific physical descriptors are required and only building blocks that construct the MOFs are used in global optimization through qualitative representations, (ii) the method is application and property independent, and (iii) the latent variable approach provides an interpretable model of qualitative building blocks with physical justification. To demonstrate the effectiveness of our method, we considered a design space with more than 47,000 MOF candidates. By searching only ~1% of the design space, LVGP-MOBBO was able to identify all MOFs on the Pareto front and more than 97% of the 50 top-performing designs for the CO$_2$ working capacity and CO$_2$/N$_2$ selectivity properties. Finally, we compared our approach with the Random Forest algorithm and demonstrated its efficiency, interpretability, and robustness.
Topology-Controlled Self-Assembly of Amphiphilic Block Copolymers
Contemporary synthetic chemistry approaches can be used to yield a range of distinct polymer topologies with precise control. The topology of a polymer strongly influences its self-assembly into complex nanostructures however a clear mechanistic understanding of the relationship between polymer topology and self-assembly has not yet been developed. In this work, we use atomistic molecular dynamics simulations to provide a nanoscale picture of the self-assembly of three poly(ethylene oxide)-poly(methyl acrylate) block copolymers with different topologies into micelles. We find that the topology affects the ability of the micelle to form a compact hydrophobic core, which directly affects its stability. Also, we apply unsupervised machine learning techniques to show that the topology of a polymer affects its ability to take a conformation in response to the local environment within the micelles.
Spectroscopy and Chemometrics/Machine-Learning News Weekly #6, 2023 – [:en]NIR Calibration Model[:de]NIR Calibration Model[:it]Modelli di Calibrazione NIR
Get the Spectroscopy and Chemometrics News Weekly in real time on Twitter @ CalibModel and follow us. "Component Prediction of Antai Pills Based on One-Dimensional Convolutional Neural Network and Near-Infrared Spectroscopy" LINK "Moisture content monitoring in withering leaves during black tea processing based on electronic eye and near infrared spectroscopy" LINK "Hyperspectral technique combined with stacking and blending ensemble learning method for detection of cadmium content in oilseed rape leaves" LINK "Capacitance spectroscopy enables realtime monitoring of early cell death in mammalian cell culture" LINK "Detection of bruised loquats based on reflectance, absorbance and Kubelka-Munk spectra" LINK "Longitudinal alterations of pulmonary [… formula…] O2 on-kinetics during moderate-intensity exercise in competitive youth cyclists are related to alterations in the …" LINK
Paraphrase Acquisition from Image Captions
Gohsen, Marcel, Hagen, Matthias, Potthast, Martin, Stein, Benno
We propose to use image captions from the Web as a previously underutilized resource for paraphrases (i.e., texts with the same "message") and to create and analyze a corresponding dataset. When an image is reused on the Web, an original caption is often assigned. We hypothesize that different captions for the same image naturally form a set of mutual paraphrases. To demonstrate the suitability of this idea, we analyze captions in the English Wikipedia, where editors frequently relabel the same image for different articles. The paper introduces the underlying mining technology, the resulting Wikipedia-IPC dataset, and compares known paraphrase corpora with respect to their syntactic and semantic paraphrase similarity to our new resource. In this context, we introduce characteristic maps along the two similarity dimensions to identify the style of paraphrases coming from different sources. An annotation study demonstrates the high reliability of the algorithmically determined characteristic maps.
Design of Bistable Soft Deployable Structures via a Kirigami-inspired Planar Fabrication Approach
Mungekar, Mrunmayi, Ma, Leixin, Yan, Wenzhong, Kackar, Vishal, Shokrzadeh, Shyan, Jawed, M. Khalid
Fully soft bistable mechanisms have shown extensive applications ranging from soft robotics, wearable devices, and medical tools, to energy harvesting. However, the lack of design and fabrication methods that are easy and potentially scalable limits their further adoption into mainstream applications. Here a top-down planar approach is presented by introducing Kirigami-inspired engineering combined with a pre-stretching process. Using this method, Kirigami-Pre-stretched Substrate-Kirigami trilayered precursors are created in a planar manner; upon release, the strain mismatch -- due to the pre-stretching of substrate -- between layers would induce an out-of-plane buckling to achieve targeted three dimensional (3D) bistable structures. By combining experimental characterization, analytical modeling, and finite element simulation, the effect of the pattern size of Kirigami layers and pre-stretching on the geometry and stability of resulting 3D composites is explored. In addition, methods to realize soft bistable structures with arbitrary shapes and soft composites with multistable configurations are investigated, which could encourage further applications. Our method is demonstrated by using bistable soft Kirigami composites to construct two soft machines: (i) a bistable soft gripper that can gently grasp delicate objects with different shapes and sizes and (ii) a flytrap-inspired robot that can autonomously detect and capture objects.