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1st IEEE International Conference on Advances in Computing, Communication and Networking, ICAC2N 2024

作者： Kumar, Vinod Jain, Isha Dongla, Durga Sritha Rai, Shivangi Rastogi, Vani Kaushik, Eva Kaushik, Rohit George Washington University School of Engineering and Applied Science WashingtonDC United States Dr. Akhilesh Das Gupta Institute of Technology and Management Computer Science and Engineering Department New Delhi India Gandhi Institute of Technology and Management Computer Science and Engineering Department Andhra Pradesh Visakhapatnam India Data Scientist DXC Technology Noida India Data Analytics Program University of Illinois CS and Mathematics Department Springfield United States

ISBN: (纸本)9798350356816

Skin pathologies encompass a spectrum of conditions, with malignancies such as melanoma representing a critical diagnostic urgency. This investigation delineates the deployment of Convolutional Neural Networks (CNNs) for the classification of dermatological anomalies, benchmarking CNN diagnostic fidelity against dermatological expert evaluations. The study underscores the efficacy of CNN classifiers in expediting the diagnostic workflow for various cutaneous disorders. Advocating for an automated diagnostic framework, the research introduces a CNN-based system aimed at reducing human diagnostic load, accelerating diagnostic timelines, and enhancing survival outcomes. Utilizing advanced image processing algorithms and deep learning architectures, the research presents an automated classification system for skin pathologies, addressing both benign and malignant presentations. The classification matrix includes nine dermatological conditions: actinic keratosis, basal cell carcinoma, benign keratosis, dermatofibroma, melanoma, nevus, seborrheic keratosis, squamous cell carcinoma, and vascular lesions. The objective is to engineer a CNN model with robust diagnostic performance across a diverse lesion dataset, ensuring accurate identification and categorization of dermatological conditions. © 2024 IEEE.

关键词： Convolutional neural networks

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Room-temperature third-order nonlinear Hall effect in Weyl semimetal TalrTe4

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National science Review 2022年第12期9卷 177-184页

作者： Cong Wang Rui-Chun Xiao Huiying Liu Zhaowei Zhang Shen Lai Chao Zhu Hongbing Cai Naizhou Wang Shengyao Chen Ya Deng Zheng Liu Shengyuan A.Yang Wei-Bo Gao College of Mathematics and Physics Beijing University of Chemical Technology Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Institute of Physical Science and Information Technology Anhui University Research Laboratory for Quantum Materials Singapore University of Technology and Design School of Materials Science and Engineering Nanyang Technological University CAS Center for Excellence in Nanoscience National Center for Nanoscience and Technology The Photonics Institute and Centre for Disruptive Photonic Technologies Nanyang Technological University

The second-order nonlinear Hall effect observed in the time-revers al symmetric system has not only shown abundant physical content,but also exhibited potential application ***,a third-order nonlinear Hall effect has been observed in MoTe2and ***,few-layer MoTe2and WTe2are usually unstable in air and the observed third-order nonlinear Hall effect can be measured only at low temperature,which hinders further investigation as well as potential ***,exploring new air-stable material systems with a sizable third-order nonlinear Hall effect at room temperature is an urgent ***,in type-Ⅱ Weyl semimetal TaIrTe4,we observed a pronounced third-order nonlinear Hall effect,which can exist at room temperature and remain stable for *** third-order nonlinear Hall effect is connected to the Berry-connection polarizability tensor instead of the Berry *** possible me chanism of the observation of the third-order nonlinear Hall effe ct in TaIrTe4at room temperature has been *** findings will open an avenue towards exploring room-temperature nonlinear devices in new quantum materials.

关键词： topological material third-order nonlinear Hall effect room temperature Berry connection polarizability tensor

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Photoionization process of the hydrogenlike carbon ion embedded in warm and hot dense plasmas

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Physical Review E 2024年第5期109卷 055205-055205页

作者： S. M. Lu F. Y. Zhou L. Y. Xie Y. L. Ma G. P. Zhao X. Gao Y. Wu J. G. Wang Institute of Modern Physics National Key Laboratory of Computational Physics Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province and College of Physics and Electronic Engineering College of Data Science School of Physics and Information Technology Center for Applied Physics and Technology College of Engineering

Complicated many-body interactions between ions and surrounding particles exist in warm and hot dense plasmas. It will significantly alter the atomic structures and dynamic properties of the embedded ions. Recently, the atomic-state-dependent (ASD) screening model has been proposed and shown to be valid for investigating the screening effect in warm and hot dense plasmas over a wide range of electron densities and temperatures. By employing the ASD model, we investigate the photoionization process for the hydrogenlike carbon ion embedded in warm and hot dense plasmas with corresponding Coulomb coupling parameter ranges of 0.05 ≤ Γ ≤ 1.16, where Γ characterizes the ratio of the average potential to thermal energy. It is found that there are stronger plasma screening effects on the ionization energy and photoionization cross section due to the negative-energy electron distributions considered in the ASD model compared to those considering only free electrons. The present results from the ASD model show reasonable agreement with the classical Debye-Hückel (DH) model in weakly coupled plasmas. However, significant deviations of the ionization energy and cross section between these two models are observed in moderately and strongly coupled plasmas, due to the approximate treatment of the plasma-electron density distribution of the DH model. In the region of low photoelectron energies, the positions of the shape resonance peaks of the cross sections obtained from the ASD model differ significantly from those of the DH model due to the different screening effects.

关键词： Atomic & molecular collisions Single- and few-photon ionization & excitation Hot dense plasma Ions

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CONVERGENCE ANALYSIS FOR A NONLOCAL GRADIENT DESCENT METHOD VIA DIRECTIONAL GAUSSIAN SMOOTHING

arXiv

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arXiv 2023年

作者： Tran, Hoang Du, Qiang Zhang, Guannan Computer Science and Mathematics Division Oak Ridge National Laboratory Oak RidgeTN37831 United States Department of Applied Physics and Applied Mathematics Data Science Institute Columbia University New YorkNY10027 United States

We analyze the convergence of a nonlocal gradient descent method for minimizing a class of high-dimensional non-convex functions, where a directional Gaussian smoothing (DGS) is proposed to define the nonlocal gradient (also referred to as the DGS gradient). The method was first proposed in [42], in which multiple numerical experiments showed that replacing the traditional local gradient with the DGS gradient can help the optimizers escape local minima more easily and significantly improve their performance. However, a rigorous theory for the efficiency of the method on nonconvex landscape is lacking. In this work, we investigate the scenario where the objective function is composed of a convex function, perturbed by a oscillating noise. We provide a convergence theory under which the iterates exponentially converge to a tightened neighborhood of the solution, whose size is characterized by the noise wavelength. We also establish a correlation between the optimal values of the Gaussian smoothing radius and the noise wavelength, thus justify the advantage of using moderate or large smoothing radius with the method. Furthermore, if the noise level decays to zero when approaching global minimum, we prove that DGS-based optimization converges to the exact global minimum with linear rates, similarly to standard gradient-based method in optimizing convex functions. Several numerical experiments are provided to confirm our theory and illustrate the superiority of the approach over those based on the local gradient. Copyright © 2023, The Authors. All rights reserved.

关键词： Gradient methods

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Global Well-Posedness and Stability of Classical Solutions to The Pressureless Navier-Stokes System in 3d

SSRN

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SSRN 2024年

作者： Guo, Boling Tang, Houzhi Zhao, Bin Institute of Applied Physics and Computational Mathematics Beijing100088 China Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China

In this paper, we consider the Cauchy problem of the pressureless Navier-Stokes system which can be derived by taking the high Mach number limit for compressible Navier-Stokes equations. Due to the absence of pressure, the classical perturbation theory developed by Matsumura and Nishida ([J. Math. Kyoto Univ., 20(1):67-104, 1980]) is not applicable to this model. The major difficulty lies in lack of the uniform boundedness of density. To solve this problem, we employ the spectral analysis and energy method to obtain the L2 time-decay rates of velocity under the additional assumption that the initial velocity is small in the L1 norm. Then combining the time-decay rates of velocity yields the uniform boundedness of density. Furthermore, it is proved that the velocity of pressureless flow decays to the motionless state at an optimal time-decay rate of (1 + t)−3/4 in the L2-norm. © 2024, The Authors. All rights reserved.

关键词： Spectrum analysis

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Lp MAXIMAL ESTIMATES FOR WEYL SUMS WITH k ≥ 3 ON T

arXiv

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arXiv 2024年

作者： Chen, Xuezhi Miao, Changxing Yuan, Jiye Zhao, Tengfei Institute of Applied Physics and Computational Mathematics Beijing100088 China Beijing100083 China School of Mathematics and Physics University of Science and Technology Beijing Beijing100083 China

In this paper, we study the Lp maximal estimates for the Weyl sums ∑N/n=1e2πi(nx+nkt) with higher-order k ≥ 3 on T, and obtain the positive and negative results. Especially for the case k = 3, our result is sharp up to the endpoint. The main idea is to investigate the structure of the set where large values of Weyl sums are achieved by making use of the rational approximation and the refined estimate for the exponential *** Codes 42B25, 42B37, 35Q41 © 2024, CC BY.

关键词： Schrodinger equation

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Machine learning-based interatomic potential for simulating irradiation damage mechanisms in ZrC

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Journal of Materials science & Technology 2026年 242卷 75-91页

作者： Chang-jie Ding Xiao-yang Wang Xiang-yan Li Wei-shu Yang Xiao-lin Li Yan-ge Zhang Yi-chun Xu Chang-song Liu Xuebang Wu Institute of Solid State Physics Hefei Institutes of Physical Science Chinese Academy of Sciences Hefei 230031 China University of Science and Technology of China Hefei 230026 China Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics Beijing 100088 China

Molecular dynamics simulation of irradiation damage is critical for understanding microstructural evolution and defect formation in zirconium carbide (ZrC). However, the absence of a suitable interatomic potential remains a challenge. Here, we develop a precise deep-neural-network based machine learning interatomic potential tailored for investigating irradiation damage in ZrC. Our model accurately reproduces the energetics and kinetics of native point defects, thermodynamics properties, surface energies, and generalized stacking fault energies. We further explore collision cascades spanning a range of primary knock-on atom energies (from 1 keV to 40 keV), types (C and Zr), and directions (〈100〉, 〈010〉, and 〈111〉) at 300 K. The results reveal carbon interstitial atoms and vacancies as the dominant point defects, consistent with first-principles calculations, with the notable formation of carbon-rich clusters within collision cascades. These carbon-rich defect clusters, resembling “black-dot” structures in experimental observations, emerge directly in collision cascades and remain thermodynamically stable at low temperatures due to the low mobility of Zr interstitial atoms. In contrast to the absence of dislocation loops in the collision cascade simulations, our results suggest a thermally-driven mechanism for the formation and transformation of 1/3 〈111〉 and 1/2 〈110〉 dislocation loops. This work enriches our understanding of the irradiation damage mechanism in ZrC and other carbide ceramics.

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GLOBAL WEAK SOLUTIONS TO THE α-MODEL REGULARIZATION FOR 3D COMPRESSIBLE EULER-POISSON EQUATIONS

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Acta Mathematica Scientia 2021年第3期41卷 679-702页

作者： Yabo REN Boling GUO Shu WANG Faculty of Science Beijing University of TechnologyBeijing 100124China Institute of Applied Physics and Computational Mathematics P.O.Box 8009Beijing 100088China

Global in time weak solutions to the α-model regularization for the three dimensional Euler-Poisson equations are considered in this paper. We prove the existence of global weak solutions to α-model regularization for the three dimension compressible EulerPoisson equations by using the Fadeo-Galerkin method and the compactness arguments on the condition that the adiabatic constant satisfies γ >4/3.

关键词： Global weak solutions α-model regularization for Euler-Poisson equations Faedo-Galerkin method

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Shortening of the results of machine translation using paraphrasing dataset 23

Shortening of the results of machine translation using parap...

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23rd Conference Information Technologies - Applications and Theory, ITAT 2023

作者： Perković, Andrej Vičič, Jernej Javorský, Dávid Bojar, Ondřej University of Primorska Faculty of Mathematics Natural Science and Information Technologies Glagoljaska 8 Koper6000 Slovenia Charles University Faculty of Mathematics and Physics Institute of Formal and Applied Linguistics Malostranské nám. 25 Prague118 00 Czech Republic

As machine translation applications continue to expand into the realm of real-time events, the need for faster and more concise translation becomes increasingly important. One such application is simultaneous speech translation, an emission of subtitles in the target language given speech in the source language. In this work, we focus on easing reader's comprehension of subtitles by making the translation shorter while preserving its informativeness. For this, we use the S, M and L version of the Paraphrase database (PPDB), and exploit their property that some of the paraphrasing rules differ in length of the left and right side. Selecting rules that make the output shorter, we fine-tune an MT model to naturally generate shorter translations. The results show that the model's conciseness improves by up to 0.61%, which leaves the space for improvements using bigger versions of PPDB in future work. © 2023 Copyright for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0). CEUR Workshop Proceedings (***)

关键词： Computational linguistics

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Two-plasmon-decay instability stimulated by dual laser beams in inertial confinement fusion

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Matter and Radiation at Extremes 2025年第1期10卷 48-56页

作者： C.-W.Lian Y.Ji R.Yan J.Li L.-F.Wang Y.-K.Ding J.Zheng Department of Modern Mechanics University of Science and Technology of ChinaHefeiAnhui 230026China Collaborative Innovation Center of IFSA Shanghai Jiao Tong UniversityShanghai 200240China Department of Plasma Physics and Fusion Engineering University of Science and Technology of ChinaHefei 230026China Institute of Applied Physics and Computational Mathematics Beijing 100088China

Two-plasmon-decay instability(TPD)poses a critical target preheating risk in direct-drive inertial confinement *** this paper,TPD collectively driven by dual laser beams consisting of a normal-incidence laser beam(Beam-N)and a large-angle-incidence laser beam(Beam-L)is investigated via particle-in-cell *** is found that significant TPD growth can develop in this regime at previously unexpected low laser intensities if the intensity of Beam-L exceeds the large-angle-incidence *** beams contribute to the growth of TPD in a“seed-amplification”manner in which the absolute instability driven by Beam-L provides the seeds that are convectively amplified by Beam-N,making TPD energetically important and causing significant pump depletion and hot-electron generation.

关键词： laser pump decay

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