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Integrating Chemical Information into Reinforcement Learning for Enhanced Molecular Geometry Optimization

Journal of chemical theory and computation 2023年第23期19卷 8598-8609页

作者： Yu-Cheng Chang Yi-Pei Li Department of Chemical Engineering National Taiwan University No. 1 Sect. 4 Roosevelt Road Taipei 10617 Taiwan. Taiwan International Graduate Program on Sustainable Chemical Science and Technology (TIGP-SCST) Academia Sinica No. 128 Sec. 2 Academia Road Taipei 11529 Taiwan.

Geometry optimization is a crucial step in computational chemistry, and the efficiency of optimization algorithms plays a pivotal role in reducing computational costs. In this study, we introduce a novel reinforcement-learning-based optimizer that surpasses traditional methods in terms of efficiency. What sets our model apart is its ability to incorporate chemical information into the optimization process. By exploring different state representations that integrate gradients, displacements, primitive type labels, and additional chemical information from the SchNet model, our reinforcement learning optimizer achieves exceptional results. It demonstrates an average reduction of about 50% or more in optimization steps compared to the conventional optimization algorithms that we examined when dealing with challenging initial geometries. Moreover, the reinforcement learning optimizer exhibits promising transferability across various levels of theory, emphasizing its versatility and potential for enhancing molecular geometry optimization. This research highlights the significance of leveraging reinforcement learning algorithms to harness chemical knowledge, paving the way for future advancements in computational chemistry.

关键词： Algorithms Geometry optimization Mathematical methods Molecules Optimization

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Gravitational-wave constraints on scalar-tensor gravity from a neutron star and black-hole binary GW200115

arXiv

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arXiv 2023年

作者： Takeda, Hiroki Tsujikawa, Shinji Nishizawa, Atsushi Department of Physics Kyoto University Kyoto606-8502 Japan Department of Physics Waseda University 3-4-1 Okubo Shinjuku Tokyo169-8555 Japan Physics Program Graduate School of Advanced Science and Engineering Hiroshima University Hiroshima Higashi-Hiroshima739-8526 Japan

In nonminimally coupled theories where a scalar field is coupled to the Ricci scalar, neutron stars (NSs) can have scalar charges through an interaction with matter mediated by gravity. On the other hand, the same theories do not give rise to hairy black hole (BH) solutions. The observations of gravitational waves (GWs) emitted from an inspiralling NS-BH binary system allows a possibility of constraining the NS scalar charge. Moreover, the nonminimally coupled scalar-tensor theories generate a breathing scalar mode besides two tensor polarizations. Using the GW200115 data of the coalescence of a BH-NS binary, we place observational constraints on the NS scalar charge as well as the nonminimal coupling strength for a subclass of massless Horndeski theories with a luminal GW propagation. Unlike past related works, we exploit a waveform for a mixture of tensor and scalar polarizations. Taking the breathing mode into account, the scalar charge is more tightly constrained in comparison to the analysis of the tensor GWs alone. In nonminimally coupled theories including Brans-Dicke gravity and spontaneous scalarization scenarios with/without a kinetic screening, we put new bounds on model parameters of each theory. Copyright © 2023, The Authors. All rights reserved.

关键词： Gravity waves

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Advanced Under-Rails Fiber-Optic Sensor for Detection of Rolling Stock and Axles in Tram Transport

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IEEE Transactions on Instrumentation and Measurement 2025年 74卷

作者： Fajkus, Marcel Jargus, Jan Nedoma, Jan Kepak, Stanislav Krizan, Daniel Cubik, Jakub Krenzelok, Tomas Leal, Arnaldo Marques, Carlos VSB—Technical University of Ostrava Faculty of Electrical Engineering and Computer Science Department of Telecommunications Ostrava708 00 Czech Republic Prodin a.s. Pardubice530 02 Czech Republic Graduate Program in Electrical Engineering Federal University of Espirito Santo Vitoria29075-910 Brazil University of Aveiro CICECO—Aveiro Institute of Materials Physics Department Aveiro3810-193 Portugal VSB—Technical University of Ostrava Department of Physics Ostrava708 00 Czech Republic

This article describes the implementation of an advanced fiber-optic intensity sensor for the comprehensive detection of axles and bogies of rail vehicles in tram transport. The sensor uses the principle of optical fiber bending, where the intensity of transmitted light is modulated due to mechanical stress on the fiber caused by the passage of a tram and the subsequent reversible deformation of the rail. The innovative design of the sensor allows for its easy installation under the rail foot, between the rail and the sleeper, replacing conventional anti-vibration pads, and includes specially designed deformable elements which the optical fiber bends and modulates the transmitted light intensity. During long-term testing (11 months in various weather conditions) conducted in the real tram depot (Ostrava, Czech Republic), 20602 tram passages were secured and analyzed. The sensor demonstrated success in detecting bogies, achieving 100% accuracy with no false positives (FPs) or false negatives (FNs). Axle detection showed an average success rate of 86.1%, with variability among different tram types up to 97.8%. The signal modulation was also subjected to detailed analysis, revealing differences in responses between various tram types, which can be attributed to differences in bogie construction and vehicle weight. Due to its electromagnetic immunity, the implemented fiber-optic sensor offers the potential for more reliable detection and broad application possibilities, including track occupancy monitoring, speed measurement, or determining the direction of travel on single-track lines. With slight optimization, the sensor could also be used to weigh rail vehicles or as an axle counter in railway or light rail transport. © 1963-2012 IEEE.

关键词： Bogies (railroad rolling stock)

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Temperature Dependent Anomalous Threshold Voltage Modulation of a-IGZO TFT by Incorporating Variant Gate Stresses

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ECS Journal of Solid State science and Technology 2024年第6期13卷 065008-065008页

作者： Aslam, Muhammad Chang, Shu-Wei Chen, Yi-Ho Lee, Yao-Jen Li, Yiming Lee, Wen-Hsi Electrical Engineering and Computer Science International Graduate Program National Yang Ming Chiao Tung University Hsinchu 300093 Taiwan Department of Electrical Engineering National Cheng Kung University Tainan 701401 Taiwan Graduate Degree Program of College of Electrical and Computer Engineering National Yang Ming Chiao Tung University Hsinchu 300093 Taiwan Institute of Pioneer Semiconductor Innovation Industry Academic Innovation School National Yang Ming Chiao Tung University Hsinchu 300093 Taiwan Department of Electronics and Electrical Engineering National Yang Ming Chiao Tung University Hsinchu 300093 Taiwan

Amorphous indium gallium zinc oxide (a-IGZO) has recently made significant advancement as a key material for electronic component design owing to its compatibility with complementary metal oxide semiconductor technologies. A comprehensive analysis of reliability-related issues is required to determine the true potential of a-IGZO-based devices for next-generation electronics applications. To address this objective, we electrically characterize scaled-channel a-IGZO thin film transistors (TFTs) under positive bias (temperature) stress (PB(T)S). Both PBS and PBTS are characterized by positive and negative V_th shift, respectively, during the various gate stresses. In particular, the negative V_th shift is explained by the generation of donor-like traps stimulated by ionization of oxygen vacancy/hydrogen at elevated temperature. The TFTs exhibit relatively decent stability during the PBS operation. The analysis of devices with variant channel dimensions implies that long-channel devices exhibit relatively higher stability and performance compared to the short-channel ones. We also observe that the V_th can be controllably adjusted by employing the top gate (TG) with bottom gate sweep. Moreover, the stress-induced partial recovery mechanism is experimentally observed owing to detrapping of charges. Generally, the reported results infer a perceptive understanding of scaled-channel a-IGZO-TFTs which helps with shaping performance-enhancement strategies. © 2024 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited

关键词： amorphous IGZO-TFT electrical instabilities hydrogen-impact scaling impact on reliability

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Health risk assessment of soil contamination with heavy metals in a child care center co-located in vicinity to small scale industrial area: Case study of Thailand

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Case Studies in Chemical and Environmental engineering 2024年 9卷

作者： Simatupang, Cathleen Ariella Santhaweesuk, Kanitthika Strezov, Vladimir Pongkiatkul, Prapat Boontanon, Narin Jindal, Ranjna Boontanon, Suwanna Kitpati Graduate Program in Environmental and Water Resources Engineering Department of Civil and Environmental Engineering Faculty of Engineering Mahidol University Nakhon Pathom 73170 Thailand School of Natural Sciences Faculty of Science and Engineering Macquarie University 2109 NSW Australia Department of Environmental Engineering King Mongkut's University of Technology Thonburi Bangkok 10800 Thailand Faculty of Environment and Resource Studies Mahidol University Nakhon Pathom 73170 Thailand Environmental Engineering and Management Program Department of Energy Environment and Climate Change School of Environment and Resources Development Asian Institute of Technology Pathumthani 12120 Thailand Graduate School of Global Environmental Studies Kyoto University Yoshida Sakyo-Ku Kyoto 606-8501 Japan

Environmental impacts of small scale industries are still not well investigated, especially for estates where multiple small scale industries are clustered causing cumulative effects potentially impacting most vulnerable groups. This study aimed to investigate the concentrations of heavy metals (Mn, Fe, Ni, Cu, Pb, Al, Zn, and Cr) and the metalloid (As) in surface soils near the intensely active small-scale industrial area in Thailand, assess the contamination levels in the co-located child care center, and estimate potential human health risks from exposure to the heavy metals. Surface soil heavy metal(loid) elements were evaluated across a background area, area near main roads, a small-scale industrial area, and a child care centre. The concentrations of Al were found be the highest at all investigation sites, with the most elevated concentrations observed in the small-scale industrial area. The concentration of Pb in the industrial area reached 1176 mg/kg, exceeding the national standard and acceptable limit. Moreover, the contamination level for Cu, Pb, and Zn in the industrial area imply a considerable risk with enrichment factor EF > 40, and geo-accumulation index Igeo ≥5. Heavy metal levels (Ni, Cu, Pb) in the soil near the road and the child care center were similar, suggesting shared contamination sources. Conversely, Al, Zn, As, and Cr in the child care center had slightly higher concentrations than near the road but lower than the small-scale industrial area, indicating potential industrial influence on metal levels within the child care center. The principal component analysis showed Mn and Fe distributed in the background, while As, Pb, Ni, Cu, Al, Zn, and Cr accumulated in the small-scale industrial area. The findings indicate that small-scale industrial activities contribute to elevated levels of heavy metals in the soil, particularly within the child care center, posing significant ingestion risks, especially for children (HI > 1). Implementing conta

关键词： Children Contamination sources Environmental impact PCA Surface soil

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Waste Valorization from Brazilian Nepheline Syenite Processing as a Strategic Approach to Advancing the Circular Economy

SSRN

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SSRN 2023年

作者： Santos, Diego Haltiery Rosa, Laura Pereira Alves, Cleidson Rosa Simão, Lisandro Arcaro, Sabrina Klegues Montedo, Oscar Rubem Raupp-Pereira, Fabiano Graduate Program in Materials Science and Engineering University of the Extreme South of Santa Catarina Criciúma88806-000 Brazil Department of Civil Engineering Federal Institute of Santa Catarina Criciúma88813-600 Brazil Research Group on Sustainability and Waste Management Postgraduate Program in Environmental Technology University of Ribeirão Preto Ribeirão Preto14096-900 Brazil Brazil

The growing disparity between the high extraction of natural resources and low use of waste as alternative mineral resources will aggravate the scarcity of natural reserves. Therefore, the current linear economy model must be converted to sustainable economic models, such as the circular economy. To achieve this transition, it is important that waste recovery strategies are implemented with a continuous search for solutions for these materials. Thus, this study investigates the waste from the processing of nepheline syenite stone, to promote its valorization as an alternative mineral resource. The classification, potentiality, quantity/viability and applicability (CPQvA) criteria are used as tools to aid decision-making for the waste valorization. The environmental, physical, chemical, morphological, and durability characteristics of nepheline syenite waste (NSW) are analyzed. The results showed evidence for the substitution of NSW for up to 100% of fine aggregates and 25% of Portland cement in civil construction. Furthermore, NSW yields recoveries of more than 90% of potassium for use in agriculture, and up to 70% of iron ore for use in steelworks. Therefore, the results indicate that NSW is viable for different applications, contributing to industrial symbiosis and a strategy for advancing the circular economy. © 2023, The Authors. All rights reserved.

关键词： Sustainable development

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TODIM and TOPSIS with Z-numbers

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Frontiers of Information Technology & Electronic engineering 2019年第2期20卷 283-291页

作者： Renato A.KROHLING André G.C.PACHECO Guilherme A.dos SANTOS Department of Production Engineering Federal University of Espirito Santo Graduate Program in Computer Science Federal University of Espirito Santo

In this paper, we present an approach that can handle Z-numbers in the context of multi-criteria decision-making problems. The concept of Z-number as an ordered pair Z=(A, B) of fuzzy numbers A and B is used, where A is a linguistic value of a variable of interest and B is a linguistic value of the probability measure of A. As human beings, we communicate with each other by means of natural language using sentences like "the journey from home to university most likely takes about half an hour." The Z-numbers are converted to fuzzy numbers. Then the Z-TODIM and Z-TOPSIS are presented as a direct extension of the fuzzy TODIM and fuzzy TOPSIS, respectively. The proposed methods are applied to two case studies and compared with the standard approach using crisp values. The results obtained show the feasibility of the approach.

关键词： Multi-criteria decision-making TODIM TOPSIS Fuzzy number Z-number

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Reliable Extrapolation of Deep Neural Operators Informed by Physics or Sparse Observations

SSRN

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SSRN 2023年

作者： Zhu, Min Zhang, Handi Jiao, Anran Karniadakis, George Em Lu, Lu Department of Chemical and Biomolecular Engineering University of Pennsylvania PhiladelphiaPA19104 United States Graduate Group in Applied Mathematics and Computational Science University of Pennsylvania PhiladelphiaPA19104 United States Department of Computer and Information Science University of Pennsylvania PhiladelphiaPA19104 United States Division of Applied Mathematics Brown University ProvidenceRI02912 United States School of Engineering Brown University ProvidenceRI02912 United States

Deep neural operators can learn nonlinear mappings between infinite-dimensional function spaces via deep neural networks. As promising surrogate solvers of partial differential equations (PDEs) for real-time prediction, deep neural operators such as deep operator networks (DeepONets) provide a new simulation paradigm in science and engineering. Pure data-driven neural operators and deep learning models, in general, are usually limited to interpolation scenarios, where new predictions utilize inputs within the support of the training set. However, in the inference stage of real-world applications, the input may lie outside the support, i.e., extrapolation is required, which may result to large errors and unavoidable failure of deep learning models. Here, we address this challenge of extrapolation for deep neural operators. First, we systematically investigate the extrapolation behavior of DeepONets by quantifying the extrapolation complexity via the 2-Wasserstein distance between two function spaces and propose a new strategy of bias-variance trade-off for extrapolation with respect to model capacity. Subsequently, we develop a complete workflow, including extrapolation determination, and we propose five reliable learning methods that guarantee a safe prediction under extrapolation by requiring additional information-the governing PDEs of the system or sparse new observations. The proposed methods are based on either fine-tuning a pre-trained DeepONet or multifidelity learning. We demonstrate the effectiveness of the proposed framework for various types of parametric PDEs. Our systematic comparisons provide practical guidelines for selecting a proper extrapolation method depending on the available information, desired accuracy, and required inference speed. © 2023, The Authors. All rights reserved.

关键词： Extrapolation

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New Energy Levels of Atomic Holmium Discovered by Laser Spectroscopy in the Near Infrared Spectral Range

SSRN

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SSRN 2024年

作者： Kın Barka, Seda Başar, Günay Kröger, Sophie Başar, Gönül Istanbul Technical University Graduate School Physics Engineering Program Maslak IstanbulTR-34469 Turkey Acibadem Mehmet Ali Aydinlar University Vocational School of Health Services Opticianry Program Atasehir IstanbulTR-34752 Turkey Istanbul Technical University Faculty of Science and Letters Physics Engineering Department Maslak IstanbulTR-34469 Turkey Hochschule für Technik und Wirtschaft Berlin Wilhelminenhofstr. 75A BerlinD-12459 Germany Istanbul University Faculty of Science Physics Department Vezneciler IstanbulTR-34134 Turkey

A combination of optogalvanic spectroscopy and laser-induced fluorescence spectroscopy with a continuous wave tunable single mode Ti-Sa laser was applied to find new energy levels of atomic holmium. Free and excited holmium atoms were produced in a liquid nitrogen-cooled hollow-cathode lamp. In this study, we examined 35 spectral lines of Ho I in the near-infrared wavelength range from 698 nm to 833 nm. Altogether, 16 new energy levels have been discovered, 5 levels of even parity and 11 levels of odd parity. Another four energy levels have been discovered but have already been published by another research group. Data on the hyperfine structure for the new levels are presented. Additionally, hyperfine structure data of three known levels of even parity were determined for the first *** existence of the new energy levels was confirmed by analyzing 60 lines of previously measured Fourier transform spectra to precisely determine the energy of the levels. © 2024, The Authors. All rights reserved.

关键词： Laser spectroscopy

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Improving Electrically Evoked Compound Action Potential Based on Electrical Field Imaging and Electrode Interfaces

Improving Electrically Evoked Compound Action Potential Base...

引用

IEEE Conference on Electromagnetic Field Computation

作者： Charles T.M. Choi Chun Ting Ke Jelani Lawrence Alexander C. C. Wang Department of Electronics and Electrical Engineering College of Electrical & Computer Engineering National Yang Ming Chiao Tung University Hsinchu Taiwan Institute of Electrical and Control Engineering College of Electrical & Computer Engineering National Yang Ming Chiao Tung University Hsinchu Taiwan Institute of Biomedical Engineering College of Electrical & Computer Engineering National Yang Ming Chiao Tung University Hsinchu Taiwan Electrical Engineering & Computer Science International Graduate Program College of Electrical & Computer Engineering National Yang Ming Chiao Tung University Hsinchu Taiwan

ISBN: (数字)9798350348958

ISBN: (纸本)9798350348965

The electrically evoked compound action potential (ECAP) has been used in various clinical studies and has become a key physiological signal for cochlear implants (CI). This study used four sensing electrodes to record ECAP signals based on the alternating polarity approach. An electrical field imaging (EFI) result based on the finite element method was used to obtain the interface impedance, then ECAP simulation results were computed and compared with a patient's clinical ECAP measurements. Preliminary modeling results show that the interface impedance obtained by this EFI-based technique can improve the simulation accuracy of the ECAP model. The ECAP modeling result will be compared with clinical ECAP measurements to validate the model in the full paper.

关键词： Electrodes Action potentials Impedance measurement computational modeling Simulation Imaging Finite element analysis

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