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94th Annual Meeting of the International Association of Applied mathematics and Mechanics, GAMM 2024

作者： Pulch, Roland Institute of Mathematics and Computer Science University of Greifswald Greifswald Germany

We consider reaction-diffusion equations, which are parabolic systems of partial differential equations. Assuming periodic boundary conditions in space, a multidimensional Fourier transform can be used. A spectral method yields an initial value problem of a stiff system of ordinary differential equations for time-dependent Fourier coefficients. We investigate the application of Rosenbrock-WannerW-schemes in the time integration of the ordinary differential equations including step size selection. Results of numerical computations are presented using a Turing system in two space dimensions. © 2024 The Author(s).

关键词： Partial differential equations

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An optimal control problem with respect to variable thicknesses for a vibrating elastic plate in a contact with a rigid obstacle

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SeMA Journal 2025年第2期82卷 251-266页

作者： Bock, Igor Institute of Computer Science and Mathematics FEI Slovak University of Technology Ilkovičova 3 Bratislava 81219 Slovakia

We deal with an optimal control problem governed by a hyperbolic variational inequality describing perpendicular vibrations of a simply supported anisotropic elastic plate against a rigid obstacle. A variable thickness of a plate plays the role of a control variable. The state problem is not uniquely solved. In order to overcome the problem of a priori estimates of states we restrict the admissible set to solutions obtained through a penalization method. We verify the existence of an optimal thickness function as a limit of the sequence of thicknesses solving the case of the penalized state problem. © The Author(s) 2025.

关键词： Optimal control Penalization Rigid obstacle Variable thickness Vibrating elastic plate

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Analysis of environmental impact factors in urban road traffic accidents: logistic regression model

Advances in Transportation Studies

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Advances in Transportation Studies 2024年第SPECIAL ISSUE期3卷 39-50页

作者： Zhao, X.J. Li, S.Y. Guan, H.B. College of Mathematics and Information Science Anyang institute of Technology Anyang455000 China School of Computer Science and Information Engineering Anyang Institute of Technology Anyang455000 China College of Mathematics and Information Science Zhengzhou University of Light Industry Zhengzhou450002 China

The traditional methods for analyzing environmental impact factors in urban road traffic accidents suffer from issues such as low recall, poor precision, and time-consuming processes. To address these challenges, a novel analysis method based on the logistic regression model is proposed. This method utilizes the MIFP-Apriori algorithm to collect urban road traffic accident data and incorporates the EM algorithm for data filling and processing. Principal component analysis is then employed to screen the environmental impact factors in urban road traffic accidents. These selected factors are input into the logistic regression model to conduct a comprehensive analysis. The results reveal that environmental impact factors like road conditions and meteorological factors have a significant influence on traffic accidents. Experimental results show that the proposed method achieves an average recall rate of 96.98%, an average precision rate of 97.66%, and the analysis time for environmental factors ranges from 0.12s to 0.52s. © 2024, Aracne Editrice. All rights reserved.

关键词： Environmental impact factors Logistic regression model Mifp-apriori algorithm Principal component analysis method Traffic accident Urban road

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Thin-shell gravastar model in f(Q,T)gravity

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Chinese Physics C 2023年第9期47卷 162-173页

作者： Sneha Pradhan Debasmita Mohanty P.K.Sahoo Department of Mathematics Birla Institute of Technology and Science-PilaniHyderabad CampusHyderabad-500078India Faculty of Mathematics&Computer Science Transilvania University of BrasovEroilor 29BrasovRomania

In the last few decades,gravastars have been proposed as an alternative to black *** stability of a gravastar has been examined in many modified theories of gravity along with Einstein's *** f(Q,T)gravity,a successfully modified theory of gravity for describing the current accelerated expansion of the universe,has been used in this study to examine gravastar in different *** to Mazur and Mottola[***.101,9545(2004);Gravitational condensate stars:An alternative to black holes,I12-011,(2002)],a gravastar has three regions with three different equations of *** this study,we examined the interior of a gravastar by consid-ering p=-ρ EoS to describe the dark sector for the interior *** next region is a thin shell of ultrarelativistic stiff fluid,in which we investigated several physical properties,including proper length,energy,entropy,and surface energy ***,we examined the surface redshift and speed of sound to check the potential stability of our proposed thin-shell gravastar ***,we used the entropy maximization technique to verify the stability of the gravastar model.A gravastar's outer region is a complete vacuum described by exterior Schwarzschild ***,we presented a stable gravastar model,which is singularity-free and devoid of any incom-pleteness in classical black hole theory.

关键词： gravastar stability f(Q,T)gravity

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On Batch Teaching Without Collusion

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Journal of Machine Learning Research 2023年第1期24卷 1-33页

作者： Fallat, Shaun Kirkpatrick, David Simon, Hans U. Soltani, Abolghasem Zilles, Sandra Department of Mathematics and Statistics University of Regina Canada Department of Computer Science University of British Columbia Canada Max Planck Institute for Informatics Germany Department of Computer Science University of Regina Canada

Formal models of learning from teachers need to respect certain criteria to avoid collusion. The most commonly accepted notion of collusion-avoidance was proposed by Goldman and Mathias (1996), and various teaching models obeying their criterion have been studied. For each model M and each concept class C, a parameter M-TD(C) refers to the teaching dimension of concept class C in model M—defined to be the number of examples required for teaching a concept, in the worst case over all concepts in C. This paper introduces a new model of teaching, called no-clash teaching, together with the corresponding parameter NCTD(C). No-clash teaching is provably optimal in the strong sense that, given any concept class C and any model M obeying Goldman and Mathias’s collusion-avoidance criterion, one obtains NCTD(C) ≤ M-TD(C). We also study a corresponding notion NCTD+ for the case of learning from positive data only, establish useful bounds on NCTD and NCTD+, and discuss relations of these parameters to other complexity parameters of interest in computational learning theory. We further argue that Goldman and Mathias’s collusion-avoidance criterion may in some settings be too weak in that it admits certain forms of interaction between teacher and learner that could be considered collusion in practice. Therefore, we introduce a strictly stronger notion of collusion-avoidance and demonstrate that the well-studied notion of Preference-based Teaching is optimal among all teaching schemes that are strongly collusion-avoiding on all finite subsets of a given concept class. ©2022 Shaun Fallat, David Kirkpatrick, Hans U. Simon, Abolghasem Soltani, and Sandra Zilles.

关键词： Adversarial machine learning

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APPROXIMATELY ARTINIAN(NOETHERIAN)C*-ALGEBRAS

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Acta Mathematica Scientia 2024年第6期44卷 2485-2497页

作者： Mohammad ROUZBEHANI Massoud AMINI Mohammad B.ASADI School of Mathematics Statistics and Computer ScienceCollege of ScienceUniversity of TehranTehranIran Department of Mathematics Faculty of Mathematical SciencesTarbiat Modares UniversityTehran 14115-134Iran School of Mathematics Institute for Research in Fundamental Sciences(IPM)Tehran 19395-5746Iran

In this article,we introduce and study the class of approximately Artinian(Noetherian)C^(*)-algebras,called AR-algebras(AN-algebras),which is a simultaneous generalization of Artinian(Noetherian)C*-algebras and *** study properties such as the ideal property and topological dimension zero for *** particular,we show that a faithful AR or AN algebra is strongly purely infinite iff it is purely infinite iff it is weakly purely *** extends the Kirchberg's O_(∞)-absorption theorem,and implies that a weakly purely infinite C^(*)-algebra is Noetherian iff every its ideal has a full projection.

关键词： C^(*)-algebra graph C^(*)-algebra Artinian Noetherian inductive limit (weakly)purely infinite ideal property

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Robust Stability of Discrete-time Genetic Regulatory Networks with Reaction Diffusion

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IAENG International Journal of Applied mathematics 2024年第9期54卷 1756-1764页

作者： Zou, Chengye Yang, Yongwei Li, Haifeng Shang, Yubao Liu, Yunong Information Science and Engineering Yanshan University Qinhuangdao066004 China School of Mathematics and Computer Science Tongling University Anhui Tongling244000 China Computer and Information Science Qinghai Institute of Technology Xining810016 China Information Science and Engineering Yanshan University Qinhuangdao066004 China

In the realm of discrete-time modeling for gene regulatory networks, significant focus has been placed on addressing the time lags inherent in the process of DNA transcription to RNA and the subsequent translation of mRNA to proteins. These temporal delays have been consistently incorporated into discrete gene regulatory network models. However, true gene regulatory networks are also subject to spatial variables, due to the uneven distribution of protein and mRNA concentrations. The integration of reaction-diffusion terms is thus essential to fully represent the impact of spatial dynamics on gene regulatory networks. In such networks, reaction-diffusion dynamics highlight the complex interactions between neighboring spatial regions, where closeness leads to mutual influences on their functional activities. Based on this conceptual groundwork, this study introduces a discrete-time gene regulatory network model that includes the mutual interconnections between spatial areas. To guarantee the model's robust stability, we have established delay-dependent stability criteria using carefully designed Lyapunov-Krasovskii functions, framed within the context of linear matrix inequalities. The robustness and effectiveness of our approach are demonstrated through a numerical example presented in this work. © (2024), (International Association of Engineers). All Rights Reserved.

关键词： Stability criteria

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A module-based framework to emotion recognition by speech: a case study in clinical simulation

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Journal of Ambient Intelligence and Humanized Computing 2023年第11期14卷 15513-15522页

作者： Sawada, Luana Okino Mano, Leandro Yukio Torres Neto, José Rodrigues Ueyama, Jó Institute of Mathematical and Computer Sciences University of São Paulo São Paulo São Carlos Brazil Johann Bernoulli Institute for Mathematics and Computer Science University of Groningen Groningen Netherlands School of Eletrical Engineering and Computer Science University of Ottawa OttawaON Canada

Current research in human–computer interaction reveals the importance of taking into account emotional aspects in the interaction with computer systems. The main objective of promoting this emotional recognition is to contribute to the enhanced coherence, consistency and credibility of the computer reactions and responses during human interaction through the human–computer interface. In that context, computer systems can be explored that can identify and classify the user’s emotional condition. In this study, computer techniques are used to identify and classify emotional aspects based on the users’ discourse, aiming to assess the emotional behavior in the daily reality of critical care professionals. Hence, in the study of computer techniques and psychological theories, both areas can be related to classify emotion through a framework for the acquisition and classification of users’ discourse. The system developed was applied as an additional evaluation method in the development of simulated scenarios in the context of Clinical Simulation and demonstrated its efficiency as a new approach in health assessment. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.

关键词： Human computer interaction

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On picking sequences for chores 23

On picking sequences for chores

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24th ACM Conference on Economics and Computation, EC 2023

作者： Feige, Uriel Huang, Xin Computer Science and Applied Mathematics Weizmann Institute of Science Rehovot Israel Computer Science Technion - Israel Institute of Technology Haifa Israel

ISBN: (纸本)9798400701047

We consider the problem of allocating m indivisible chores to n agents with additive disvaluation (cost) functions. It is easy to show that there are picking sequences that give every agent (that uses the greedy picking strategy) a bundle of chores of disvalue at most twice her share value (maximin share, MMS, for agents of equal entitlement, and anyprice share, APS, for agents of arbitrary entitlement). Aziz, Li and Wu (2022) designed picking sequences that improve this ratio to 5/3 for the case of equal entitlement. We design picking sequences that improve the ratio to 1.733 for the case of arbitrary entitlement, and to 8/5 for the case of equal entitlement. (In fact, computer assisted analysis suggests that the ratio is smaller than 1.543 in the equal entitlement case.) We also prove a lower bound of 3/2 on the obtainable ratio when n is sufficiently *** results trivially imply that (for additive valuation over chores) in the arbitrary entitlement case, there always is an allocation that gives every agent at most 1.733APS, and in the equal entitlement case, there always is a distribution over allocations that gives every agent at most 1.6MMS ex-post, and at most the proportional share ex-ante. Neither of these implications were previously known to *** contributions of our work include improved guarantees in the equal entitlement case when n is small;introduction of the chore share as a convenient proxy to other share notions for chores;introduction of ex-ante notions of envy for risk averse agents, and enhancements to our picking sequences that eliminate such envy. © 2023 Owner/Author(s).

关键词： Additives

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Mutual Retinex: Combining Transformer and CNN for Image Enhancement

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IEEE Transactions on Emerging Topics in Computational Intelligence 2024年第3期8卷 2240-2252页

作者： Jiang, Kui Wang, Qiong An, Zhaoyi Wang, Zheng Zhang, Cong Lin, Chia-Wen Harbin Institute of Technology School of Computer Science and Technology Harbin150001 China Wuhan University National Engineering Research Center for Multimedia Software School of Computer Science Wuhan430072 China Wuhan Polytechnic University School of Mathematics and Computer Science Wuhan430024 China National Tsing Hua University Department of Electrical Engineering Institute of Communications Engineering Hsinchu30013 Taiwan

Images captured in low-light or underwater environments are often accompanied by significant degradation, which can negatively impact the quality and performance of downstream tasks. While convolutional neural networks (CNNs) and Transformer architectures have made significant progress in computer vision tasks, there are few efforts to harmonize them into a more concise framework for enhancing such images. To this end, this study proposes to aggregate the individual capability of self-attention (SA) and CNNs for accurate perturbation removal while preserving background contents. Based on this, we carry forward a Retinex-based framework, dubbed as Mutual Retinex, where a two-branch structure is designed to characterize the specific knowledge of reflectance and illumination components while removing the perturbation. To maximize its potential, Mutual Retinex is equipped with a new mutual learning mechanism, involving an elaborately designed mutual representation module (MRM). In MRM, the complementary information between reflectance and illumination components are encoded and used to refine each other. Through the complementary learning via the mutual representation, the enhanced results generated by our model exhibit superior color consistency and naturalness. Extensive experiments have shown the significant superiority of our mutual learning based method over thirteen competitors on the low-light task and ten methods on the underwater image enhancement task. In particular, our proposed Mutual Retinex respectively surpasses the state-of-the-art method MIRNet-v2 by 0.90 dB and 2.46 dB in PSNR on the LOL 1000 and FIVEK datasets, while with only 19.8% model parameters. © 2017 IEEE.

关键词： Image enhancement

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