检索结果-内蒙古大学图书馆

Examining finite-time behaviors in the fractional Gray–Scott model: Stability, synchronization, and simulation analysis

引用

International Journal of Cognitive Computing in Engineering 2025年 6卷 380-390页

作者： Momani, Shaher Batiha, Iqbal M. Bendib, Issam Ouannas, Adel Hioual, Amel Mohamed, Dalah Department of Mathematics Faculty of Science The University of Jordan Amman11942 Jordan Ajman University Ajman United Arab Emirates Department of Mathematics Al Zaytoonah University of Jordan Amman11733 Jordan Applied Mathematics & Modeling Laboratory Department of Mathematics Faculty of Exact Sciences University of Brothers Mentouri Constantine25000 Algeria Department of Mathematics and Computer Science University of Oum El Bouaghi Oum El Bouaghi04000 Algeria

This paper investigates the behavior and stability of the fractional-order Gray–Scott model, with a specific focus on achieving finite-time stability and synchronization. It introduces essential concepts, including the Gamma function, the Riemann–Liouville fractional-order integral operator, the Caputo fractional derivative, and the Mittag-Leffler function, to establish a foundational framework for subsequent analysis. Equilibrium points are defined, distinguishing between initial and finite-time equilibria, and the conditions for finite-time stability, including settling time, are precisely outlined. Stability results for this model are presented through theorems with detailed proofs, elucidating the roles of Lyapunov functions, class functions, and other system parameters. Furthermore, the paper explores finite-time synchronization schemes in master–slave systems, providing a mathematical framework for understanding and achieving synchronization within a finite time frame. This framework illuminates synchronization dynamics and their practical implications for controlling complex systems. Additionally, numerical examples illustrate finite-time stability and synchronization within the Gray–Scott reaction–diffusion model. © 2025 The Authors

关键词： Lyapunov functions

来源：评论

学校读者我要写书评

暂无评论

Availability assessment of repairable linear consecutive k-out-of-n: F systems incorporating uncertainty and multiple failure modes

引用

Life Cycle Reliability and Safety Engineering 2025年 1-10页

作者： Khati, Amisha Singh, S.B. Department of Mathematics Statistics and Computer Science G. B. Pant University of Agriculture and Technology Pantnagar India Department of Applied Science and Humanities RIT Roorkee India

This study evaluates the interval-valued availability of a linear consecutive k-out-of-n: F system while considering uncertainty, where the probability that the system will perform as intended is not known with precision. The proposed system is susceptible to µ number of different failure modes and undergoes periodic inspections. Each failure mode has a randomly assigned failure time, and upon failure due to the mth failure mode, an immediate corrective repair is carried out, taking an arbitrary length of time ψm (m = 1, 2,…, µ). By integrating these factors, this research establishes theorems describing point and steady-state availability bounds. Subsequently, it conducts a sensitivity assessment to evaluate how variations in the inspection period affect the system’s availability. The findings are demonstrated with an instance of an oil pipeline system. This study offers valuable insights into the reliability and availability modelling of complex systems under uncertainty, with applications across diverse engineering domains. © The Author(s), under exclusive licence to Society for Reliability and Safety (SRESA) 2025.

关键词： Interval valued point availability Interval valued steady state availability Linear consecutive k-out-of n: F system Multiple failure modes Sensitivity analysis Uncertainty

来源：评论

学校读者我要写书评

暂无评论

Strongly coupled two-scale system with nonlinear dispersion: weak solvability and numerical simulation

引用

Zeitschrift fur Angewandte Mathematik und Physik 2025年第3期76卷 1-26页

作者： Raveendran, Vishnu Nepal, Surendra Lyons, Rainey Eden, Michael Muntean, Adrian Institute for Numerical Simulation University of Bonn Bonn Germany Department of Mathematics and Computer Science Karlstad University Karlstad Sweden Department of Applied Mathematics University of Colorado Boulder Boulder CO United States

We investigate a two-scale system featuring an upscaled parabolic dispersion–reaction equation intimately linked to a family of elliptic cell problems. The system is strongly coupled through a dispersion tensor, which depends on the solutions to the cell problems, and via the cell problems themselves, where the solution of the parabolic problem interacts nonlinearly with the drift term. This particular mathematical structure is motivated by a rigorously derived upscaled reaction–diffusion–convection model that describes the evolution of a population of interacting particles pushed by a large drift through an array of periodically placed obstacles (i.e., through a regular porous medium). We prove the existence and uniqueness of weak solutions to our system by means of an iterative scheme, where particular care is needed to ensure the uniform positivity of the dispersion tensor. Additionally, we use finite element-based approximations for the same iteration scheme to perform multiple simulation studies. Finally, we highlight how the choice of micro-geometry (building the regular porous medium) and of the nonlinear drift coupling affects the macroscopic dispersion of particles. © The Author(s) 2025.

关键词： Iterative scheme Nonlinear dispersion Simulation Two-scale system Weak solutions

来源：评论

学校读者我要写书评

暂无评论

Metrics of Success: Evaluating User Satisfaction in AI Chatbots 24

Metrics of Success: Evaluating User Satisfaction in AI Chatb...

引用

8th International Conference on Advances in Artificial Intelligence, ICAAI 2024

作者： Møller, Cecilie Grace Ang, Ke En de Lourdes Bongiovanni, María Khalid, Md Saifuddin Wu, Jiayan Department of Digitalization Copenhagen Business School Fredriksberg Denmark Department of Applied Mathematics and Computer Science Danmarks Tekniske Universitet Lyngby Denmark

ISBN: (纸本)9798400718014

The rapid advancement of Artificial Intelligence (AI), particularly through Large Language Models (LLMs), has catalysed a technological revolution, leading to the widespread adoption of AI-driven chatbots across industries. OpenAI’s customisable generative pretrained transformer (GPT) offerings have popularised generative AI, enabling organisations of all sizes to implement chatbots for customer support. This development presents an opportunity for businesses to offer 24/7, cost-efficient customer service that can overcome the historical limitations of chatbots that lack a "human element." However, despite the proliferation of AI chatbots, there remains a crucial need to evaluate their effectiveness in meeting user needs and preferences for human-like interaction. Current service quality assessment tools, such as SERVQUAL and E-SERVQUAL, are unable to evaluate AI-specific capabilities like language intelligence and recognition. Existing research also lacks information on factors that affect user satisfaction and the continued use of AI chatbots. Based on a mixed-methods study, this paper proposes a new instrument for measuring user satisfaction with AI chatbots, specifically for customer support roles. Using the Stanford five-step Design Thinking Process, this study devised a customer support AI chatbot evaluation instrument through a literature review, Cheatstorming, and SCAMPER techniques, followed by testing in a Danish company. The research employs Prentice and Nguyen’s three-stage scale development process to ensure content, reliability, and construct validity, addressing gaps in current scholarship and advancing understanding of AI chatbot user satisfaction. © 2024 Copyright held by the owner/author(s).

关键词： Sales

来源：评论

学校读者我要写书评

暂无评论

Some Results on Ricci-Yamabe Soliton and Its Cosmological Models

引用

IAENG International Journal of applied mathematics 2025年第4期55卷 979-983页

作者： Pandey, Pankaj Yadav, Santosh Kumar Sharma, Kamakshi Chaturvedi, Braj Bhushan Department of Mathematics School of Chemical Engineering and Physical Sciences Lovely Professional University Punjab Phagwara144411 India Department of Mathematics School of Computer Science & Artificial Intelligence SR University Telangana Warangal506371 India Department of Pure & Applied Mathematics Guru Ghasidas Vishwavidyalaya Chhattisgarh Bilaspur495009 India

This article aims to investigate the characteristics of Ricci-Yamabe Soliton (briefly: (RYS)n). We study the cosmological models on (RYS)4 under Lorentzian para Sasakian (LPS)4 spacetime. Parallel Ricci tensor, Poisson structure and gradient property also reveal on (RYS)n. Example of (RYS)4 constructed to verify the results. © (2025), (International Association of Engineers). All rights reserved.

关键词： Solitons

来源：评论

学校读者我要写书评

暂无评论

On Error-Based Step Size Control for Discontinuous Galerkin Methods for Compressible Fluid Dynamics

引用

应用数学与计算数学学报 2025年第1期7卷 3-39页

作者： Hendrik Ranocha Andrew R.Winters Hugo Guillermo Castro Lisandro Dalcin Michael Schlottke-Lakemper Gregor J.Gassner Matteo Parsani Applied Mathematics University of HamburgBundesstr.5520146 HamburgGermany Department of Mathematics Applied Mathematics Linköping UniversityLinköpingSweden Extreme Computing Research Center(ECRC) Computer Electrical and Mathematical Science and Engineering Division(CEMSE)King Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Saudi Arabia Applied and Computational Mathematics RWTH Aachen UniversityAachenGermany High-Performance Computing Center Stuttgart University of StuttgartStuttgartGermany Department of Mathematics and Computer Science University of CologneCologneGermany Center for Data and Simulation Science University of CologneCologneGermany Extreme Computing Research Center(ECRC) Computer Electrical and Mathematical Science and Engineering Division(CEMSE)King Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Saudi Arabia Physical Science and Engineering Division(PSE) King Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Saudi Arabia

We study a temporal step size control of explicit Runge-Kutta(RK)methods for com-pressible computational fluid dynamics(CFD),including the Navier-Stokes equations and hyperbolic systems of conservation laws such as the Euler *** demonstrate that error-based approaches are convenient in a wide range of applications and compare them to more classical step size control based on a Courant-Friedrichs-Lewy(CFL)*** numerical examples show that the error-based step size control is easy to use,robust,and efficient,e.g.,for(initial)transient periods,complex geometries,nonlinear shock captur-ing approaches,and schemes that use nonlinear entropy *** demonstrate these properties for problems ranging from well-understood academic test cases to industrially relevant large-scale computations with two disjoint code bases,the open source Julia pack-ages *** with *** and the C/Fortran code SSDC based on PETSc.

关键词： Explicit Runge-Kutta(RK)methods Step size control Compressible fluid dynamics Adaptivity in space and time Shock capturing

来源：评论

学校读者我要写书评

暂无评论

Comparative analysis of carbon dioxide and hydrogen plume migration in aquifers inspired by the FluidFlower benchmark study

引用

International Journal of Hydrogen Energy 2025年 135卷 56-68页

作者： Misaghi Bonabi, Amin van Rooijen, Willemijn Al Kobaisi, Mohammed Vuik, Cornelis Hajibeygi, Hadi Department of Applied Mathematics Faculty of Electrical Engineering Mathematics and Computer Science Delft University of Technology Delft Netherlands Department of Geoscience and Engineering Faculty of Civil Engineering and Geosciences Delft University of Technology Delft Netherlands

Large-scale geological storages of hydrogen (H2) and carbon dioxide (CO2) in saline aquifers present feasible options for a sustainable energy future. We compared the plume migration of CO2 and H2 in aquifers using the FluidFlower benchmark, incorporating the state-of-the-art thermophysical and petrophysical properties. The H2 plume, with its higher buoyancy and mobility compared to CO2, remains predominantly in the gas phase due to its lower solubility, increasing the chances of escaping through fractures or migration to distant regions. This additionally leads to a higher pressurized reservoir, which, along with higher buoyancy, increases the chance of caprock penetration. Dissolution trapping of CO2 into brine increases over time due to its fingering, while H2 does not show fingering. Our findings show that while geological carbon storage (GCS) benefits significantly from all structural, dissolution, and residual trapping, underground hydrogen storage (UHS) relies mainly on structural trapping, making the integrity of sealing elements of the system a key factor in its performance. © 2025 The Authors

关键词： Two phase flow

来源：评论

学校读者我要写书评

暂无评论

Simulation of Electromagnetic Wave Propagation in Graphene-Coated 1D Photonic Crystals Using the Finite Volume Method

Simulation of Electromagnetic Wave Propagation in Graphene-C...

引用

2024 International Conference on Interdisciplinary Physics, ICIPs 2024

作者： Negara, Teguh Puja Hardhienata, Hendradi Alatas, Husin Study Program of Computer Science Faculty of Mathematics and Natural Science Universitas Pakuan Bogor Indonesia Theoretical Physics Division Department of Physics Faculty of Mathematics and Natural Science IPB University Bogor Indonesia

A numerical study on the interaction of electromagnetic waves with photonic crystals with one-dimensional periodicity has been carried out using the Finite Volume method. The photonic crystals with one-dimensional periodicity consists of 7 alternating layers of and with thicknesses of and, respectively. Electromagnetic field components have been simulated to propagate through the photonic crystal structure, experiencing reflection and transmission at each layer of the structure. The simulation results show the occurrence of absorption precisely at the Bragg frequency by the photonic crystal, which is referred to as the photonic band gap (PBG). A comparison of the simulation results has been conducted using different fluxes, such as the Lax-Friedrichs and upwind schemes, under PBG conditions. The results show smoother absorption using the Lax-Friedrichs scheme. Additionally, the use of a single-layer graphene on the front side of the photonic crystal has shown more perfect absorption compared to without the single-layer graphene. Therefore, the integrated graphene-photonic crystal system can be used as a perfect reflector. The simulation runs well using effective absorbing boundary conditions (ABCs) to reduce wave reflections at the edges of the computational window. Based on the simulation results, the Finite Volume method has been proven to be a powerful tool in describing electromagnetic wave propagation through photonic crystal systems with or without graphene. These findings provide a foundational model for fabrication approaches and holds potential for future advancements in sensor technologies, moreover two-dimensional and three-dimensional structures. © 2025 Institute of Physics Publishing. All rights reserved.

关键词： Photonic band gap

来源：评论

学校读者我要写书评

暂无评论

Queueing Model with Correlated Arrival Process, Simultaneous Service of a Finite Number of Customers, and Pre-processing, Post-processing and Co-processing of Customers 23rd

Queueing Model with Correlated Arrival Process, Simultaneou...

引用

23rd International Conference on Information Technologies and Mathematical Modelling, ITMM 2024

作者： Dudin, Alexander Dudina, Olga Department of Applied Mathematics and Computer Science Belarusian State University Minsk 220030 Belarus

ISBN: (纸本)9783031883064

In this paper, we analyse a queueing model with a Markov arrival process and the possibility of simultaneous service of a finite number of customers defined by the multidimensional Markov chain. Service in this system is implemented in cooperation with another, infinite-server, queueing system. The variants when service in the infinite-server system is implemented before, after, and in parallel with service in the main system are considered. An explicit form of the generator of the multidimensional Markov chains describing the analysed variants of the queueing system is obtained. It is shown that in all these variants, the system is stable. The way for solving the problem of the stationary distribution computation in these variants is outlined as well. The results can be used for optimization of the choice of the system parameters. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.

关键词： ergodicity MAP simultaneous service stationary distribution tandem queue

来源：评论

学校读者我要写书评

暂无评论

Integrative Analysis of Gene Co-Expression Networks Combined with Flux Balance Analysis of Metabolic Models for Insights into Chronic Obstructive Pulmonary Disease 10

Integrative Analysis of Gene Co-Expression Networks Combined...

引用

10th International Conference on Digital Arts, Media and Technology and 8th ECTI Northern Section Conference on Electrical, Electronics, computer and Telecommunications Engineering, ECTI DAMT and NCON 2025

作者： Paklao, Thummarat Suratanee, Apichat Plaimas, Kitiporn Chulalongkorn University Faculty of Science Department of Mathematics and Computer Science Bangkok Thailand King Mongkut's University of Technology North Bangkok Faculty of Applied Science Department of Mathematics Bangkok Thailand

ISBN: (纸本)9798331543273

Chronic obstructive pulmonary disease (COPD) is a complex respiratory condition involving multifaceted molecular mechanisms. Differential gene expression analysis has identified genes with significant up-regulation and down-regulation in COPD patients compared to healthy controls, as well as those exhibiting high expression variability. However, relying solely on gene expression analysis is insufficient to fully understand these mechanisms. Therefore, in this study, we propose combining gene expression analysis, its co-expression network, and flux balance-based metabolic models to gain a deeper understanding of the disease's complexity. This integration has revealed several metabolic subsystems associated with COPD and established a concordance between flux values and gene expression in COPD-related clusters. It demonstrates how effectively computational approaches can capture the molecular and metabolic alterations underlying COPD and align with experimental outcomes. The findings also offer biomarkers and pathways that can serve as a foundation for the development of COPD treatments. In summary, this study highlights the efficacy of an integrative computational approach that merges gene expression analysis, co-expression networks, and flux balance-based metabolic models. This methodology establishes connections between gene expression and metabolic flux while providing a valuable framework for future computational investigations and therapeutic strategies targeting COPD. © 2025 IEEE.

关键词： Transcription

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：