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Science, engineering and Business for Sustainable Development Goals (SEB-SDG), International Conference on

作者： Bankola Gbenga Ogunware Ezekiel Olaoluwa Omole Adefunke Bosede Familua Peter Onu Ridwanulahi Iyanda Abdlganiy Femi Emmanuel Amoyedo Kehinde Peter Ajewole Patrick Moses Edoma Department of Mathematics and Statistics Joseph Ayo Babalola University Ikeji - Arakeji Nigeria Department of Physical Sciences Mathematics Programme Landmark University Omu-Aran Nigeria Department of Mathematics First Technical University Ibadan Oyo State Nigeria Department of Mechanical Engineering (Mechatronics) Landmark University Omu-Aran Nigeria Distant Learning Institute University of Lagos Lagos State Nigeria Department of Statistics Federal University of Technology Akure Ondo State Nigeria

ISBN: (数字)9798350358155

ISBN: (纸本)9798350358162

This paper investigates a distinct numerical algorithm for the solution of first and second orders initial value problems. The new method was developed using interpolation and collocation approach, with power series approximate solution used as interpolating polynomials. The numerical integrators of the block were obtained by evaluating the non-interpolation points within the chosen integration interval. To assess the efficiency of the proposed block method, it was tested on some first and second orders ordinary differential equations with initial value problems, and the results produced outperformed existing methods in terms of accuracy.

关键词： Interpolation Accuracy Ordinary differential equations Approximation algorithms Polynomials Sustainable development Business

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Analysis and Research on Energy Transfer from Wind to Waves Based on the SWAN Model

Analysis and Research on Energy Transfer from Wind to Waves ...

引用

2024 International Conference on New Power System and Power Electronics, NPSPE 2024

作者： Wang, Lei Li, Ying Zhang, Lei Zhang, Feng Zheng, Chongwei Luo, Chenghan Sichuan University of Science & Engineering College of Mathematics and Statistics Yibin China Navigation College of Dalian Maritime University Dalian China People's Liberation Army Unit 91001 Beijing China Minjiang University College of Physics & Electronic Information Engineering Fuzhou China Chinese People's Liberation Army Dalian Naval Academy Department of Navigation Dalian China

ISBN: (纸本)9798350389869

The mechanisms of energy transfer, storage, and dissipation at the ocean-atmosphere interface are crucial scientific issues in physical oceanography. In this paper, ten numerical experiments are systematically designed based on the SWAN ocean model to investigate the wind-to-wave energy transfer under constant wind field. The SWAN model employs its default wind stress drag coefficient to furnish the sea surface wind field across varying wind speeds, constructing a theoretically infinite-width and infinite-depth model, featuring free inflow and outflow boundaries for current and waves. In the numerical experiments, after the model reaches stability, wave energy experiences a rapid growth phase at wind speeds of 5-30 m/s. At around 10 m/s, corresponding to the wind speeds of monsoons and cold surges, the energy of the water column waves per unit area reaches 4.59x103 J (joules). At wind speeds of 3050 m/s, corresponding to typhoon-level wind speeds, the wave energy growth trend slows down. Finally, a parameterization scheme for the flux (WA) of atmospheric kinetic energy entering waves with respect to wind speed (U) under constant wind speeds is presented. This research has a substantial influence on atmospheric and oceanic circulation, and it is crucial for precise computation and practical prediction in numerical models. © 2024 IEEE.

关键词： Kinetic energy

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Deep reinforcement learning for the dynamic vehicle dispatching problem: An event-based approach

arXiv

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arXiv 2023年

作者： Cordeiro, Edyvalberty Alenquer Pitombeira-Neto, Anselmo R. Department of Applied Mathematics and Statistics Federal University of Ceará Fortaleza Brazil Department of Industrial Engineering Federal University of Ceará Fortaleza Brazil

The dynamic vehicle dispatching problem corresponds to deciding which vehicles to assign to requests that arise stochastically over time and space. It emerges in diverse areas, such as in the assignment of trucks to loads to be transported;in emergency systems;and in ride-hailing services. In this paper, we model the problem as a semi-Markov decision process, which allows us to treat time as continuous. In this setting, decision epochs coincide with discrete events whose time intervals are random. We argue that an event-based approach substantially reduces the combinatorial complexity of the decision space and overcomes other limitations of discrete-time models often proposed in the literature. In order to test our approach, we develop a new discrete-event simulator and use double deep q-learning to train our decision agents. Numerical experiments are carried out in realistic scenarios using data from New York City. We compare the policies obtained through our approach with heuristic policies often used in practice. Results show that our policies exhibit better average waiting times, cancellation rates and total service times, with reduction in average waiting times of up to 50% relative to the other tested heuristic policies. Copyright © 2023, The Authors. All rights reserved.

关键词： Reinforcement learning

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The origin of vorticity in viscous incompressible flows

arXiv

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arXiv 2025年

作者： Xiang, Tianrui Eyink, Gregory L. Zaki, Tamer A. Department of Mechanical Engineering Johns Hopkins University BaltimoreMD21218 United States Department of Applied Mathematics and Statistics Johns Hopkins University BaltimoreMD21218 United States

In inviscid, incompressible flows, the evolution of vorticity is exactly equivalent to that of an infinitesimal material line-element, and hence vorticity can be traced forward or backward in time in a Lagrangian fashion. This elegant and powerful description is not possible in viscous flows due to the action of diffusion. Instead, a stochastic Lagrangian interpretation is required and was recently introduced, where the origin of vorticity at a point is traced back in time as an expectation over the contribution from stochastic trajectories. We herein introduce for the first time an Eulerian, adjoint-based approach to quantify the back-in-time origin of vorticity in viscous, incompressible flows. The adjoint variable encodes the advection, tilting and stretching of the earlier-in-time vorticity that ultimately leads to the target value. Precisely, the adjoint vorticity is the volume-density of the mean Lagrangian deformation of the earlier vorticity. The formulation can also account for the injection of vorticity into the domain at solid boundaries. We demonstrate the mathematical equivalence of the adjoint approach and the stochastic Lagrangian approach. We then provide an example from turbulent channel flow, where we analyze the origin of high-stress events and relate them to Lighthill’s mechanism of stretching of near-wall vorticity. © 2025, CC BY.

关键词： Stochastic systems

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Experiments at the JSI TRIGA Research Reactor for Validation of Nuclear Fuel Depletion Calculations

Experiments at the JSI TRIGA Research Reactor for Validation...

引用

2024 International Conference on Physics of Reactors, PHYSOR 2024

作者： Anže, Pungerčič Vladimir, Radulović Alireza, Haghighat Luka, Snoj Reactor Physics Department "Jožef Stefan" Institute Jamova cesta 39 Ljubljana1000 Slovenia Faculty of Mathematics and Physics University of Ljubljana Jadranska ul. 19 Ljubljana1000 Slovenia Nuclear Engineering Program Mechanical Engineering Dept. Virginia Tech 900 N. Glebe Road United States

ISBN: (纸本)9780894487972

Importance of experimental methods at research reactors for validation of depletion calculation is discussed. The validation of fuel burnup and nuclide inventory, calculated with stochastic Serpent-2 and hybrid RAPID code system, is performed at JSI TRIGA research reactor. Three different experimental method for indirect burnup determination are presented. The experiments are simulated using Serpent-2 and RAPID depletion codes. First experiment is the fuel rod reactivity worth experiment, in which seven differently burned rods were inserted in the reactor and change in core reactivity was measured. Each insertion was simulated with both codes and great agreement (within 1σ) is observed for both codes. Core's excess reactivity reduction due to burnup was analyzed on three mixed TRIGA cores. Burnup reactivity coefficient was studied with both codes and accurate predictions of reactivity change were obtained. Finally, depleted nuclide inventory is used to simulate dosimetry experiment. Axial profile of 197Au(n, γ)198Au reaction rates was studied using MCNP, where fresh fuel model was compared to the burned fuel model. Fuel burnup was obtained from Serpent-2 and RAPID. The results indicate a 6 % better agreement when Serpent-2 and RAPID's burnup is used. All three experiments indicate a method on how research reactor can be used to in-directly determine and validate nuclear fuel burnup without the use of destructive methods. © 2024 AMERICAN NUCLEAR SOCIETY. All rights reserved.

关键词： Research reactors

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MoS Modified Screen Printed Carbon Electrode Based Flexible Electrochemical Sensor for Detection of Copper Ions in Water

引用

IEEE Sensors Journal 2023年第8期23卷 8146-8153页

作者： Neethipathi, Deepan Kumar Beniwal, Ajay Bass, Adrian M. Scott, Marian Dahiya, Ravinder University of Glasgow School of Engineering GlasgowG12 8QQ United Kingdom University of Glasgow School of Geography and Earth Science GlasgowG12 8QQ United Kingdom University of Glasgow School of Mathematics and Statistics GlasgowG12 8QQ United Kingdom Group Electrical and Computer Engineering Department BostonMA02115 United States

Heavy metal ions (HMI), such as Cu $^{{2}+}$ , are harmful to the environment and our health. Such ions are typically measured using glassy carbon electrode (GCE)-based electrochemical sensors developed on rigid substrates. However, several emerging applications require such sensors on flexible, and even disposable, substrates. Herein, we present a molybdenum disulfide (MoS2)-modified screen-printed carbon electrode (SPCE)-based flexible electrochemical sensor for the detection of copper ions in the water. The sensor exhibits excellent response with a limit of detection (LOD) of $5.43 \mu \text{M}$ for Cu ions in the range of $5 \mu \text{M}$ - 5 mM. The developed sensor is compared with MoS2-modified conventional GCE using electrochemical impedance spectroscopy (EIS). The comparative studies show better linearity ( ${R}^{{2}}$ value $\sim $ 0.99) for SPCE-based sensor and underline how easily they can detect Cu ions. The interference study, i.e., detection of copper ions in the presence of other HMI-based analytes, also shows the excellent response of SPCE-based flexible electrochemical sensor - thus, demonstrating their practical application is the detection of Cu in water. © 2001-2012 IEEE.

关键词： Carbon

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A Uniform Accurate Boundary Treatment for the One-Dimensional Non-Local Models

引用

Journal of Peridynamics and Nonlocal Modeling 2023年第2期5卷 155-182页

作者： Pang, Gang Ji, Songsong Zhang, Jiwei Qian, Dong School of Mathematical Science Beihang University Beijing 100083 China HEDPS CAPT and LTCS College of Engineering Peking University Beijing 100871 China School of Mathematics and Statistics and Hubei Key Laboratory of Computational Science Wuhan University Wuhan 430072 China Department of Mechanical Engineering University of Texas at Dallas Richardson 75080-3021 TX United States

A uniform boundary treatment is proposed to construct the exact artificial boundary conditions for the one-dimensional non-local models. To this end, we first convert the governing equation of the non-local model into a semi-discretized version, and then an accurate numerical method is proposed for computing the Green’s function for the semi-discretized non-local model. These Green’s functions are then used to build the exact boundary conditions corresponding to the semi-discretized model. The numerical method is applied for three non-local models. The numerical results illustrate the efficiency of the boundary conditions. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.

关键词： Boundary treatment Green’s functions Recursive relationship Semi-discretized non-local models

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Integrable Fractional Modified Korteweg-de Vries, Sine-Gordon, and Sinh-Gordon Equations

arXiv

引用

arXiv 2022年

作者： Ablowitz, Mark J. Been, Joel B. Carr, Lincoln D. Department of Applied Mathematics University of Colorado BoulderCO United States Department of Applied Mathematics and Statistics Department of Physics Colorado School of Mines GoldenCO United States Quantum Engineering Program Department of Applied Mathematics and Statistics Department of Physics Colorado School of Mines GoldenCO United States

The inverse scattering transform allows explicit construction of solutions to many physically significant nonlinear wave equations. Notably, this method can be extended to fractional nonlinear evolution equations characterized by anomalous dispersion using completeness of suitable eigenfunctions of the associated linear scattering problem. In anomalous diffusion, the mean squared displacement is proportional to tα, α > 0, while in anomalous dispersion, the speed of localized waves is proportional to Aα, where A is the amplitude of the wave. Fractional extensions of the modified Korteweg-deVries (mKdV), sine-Gordon (sineG) and sinh-Gordon (sinhG) and associated hierarchies are obtained. Using symmetries present in the linear scattering problem, these equations can be connected with a scalar family of nonlinear evolution equations of which fractional mKdV (fmKdV), fractional sineG (fsineG), and fractional sinhG (fsinhG) are special cases. Completeness of solutions to the scalar problem is obtained and, from this, the nonlinear evolution equation is characterized in terms of a spectral expansion. In particular, fmKdV, fsineG, and fsinhG are explicitly written. One-soliton solutions are derived for fmKdV and fsineG using the inverse scattering transform and these solitons are shown to exhibit anomalous dispersion. © 2022, CC BY.

关键词： Dispersion (waves)

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A Guaranteed Cost Approach to Dynamic Output Feedback Control for Neutral-Type Markovian Jumping Stochastic Systems

引用

Journal of Systems Science & Complexity 2021年第4期34卷 1487-1500页

作者： LI Yanbo KAO Binghua XIE Jing KAO Yonggui School of Information and Statistics Guangxi University of Finance and EconomicsNanning 530003China Department of Mathematics Harbin Institute of Technology(Weihai)Weihai 264209China School of Information and Control Engineering Qingdao University of TechnologyQingdao 266520China

This paper is devoted to investigating the dynamic output feedback(DOF)control problem of Markovian jump neutral-type stochastic systems with a guaranteed cost *** of the state and measurement equations contain time ***-dependent DOF controllers are first designed such that the closed-loop system is asymptotically stable in mean-square and an adequate performance level of this system is ***,sufficient conditions for the solvability of this problem are derived in the form of linear matrix inequalities(LMIs).A numerical example is presented to reveal the effectiveness of our findings.

关键词： Guaranteed cost control linear matrix inequality Markovian jump neutral stochastic systems output feedback control time delay

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Young Measure Relaxation Gaps for Controllable Systems with Smooth State Constraints

SSRN

引用

SSRN 2025年

作者： Augier, Nicolas Korda, Milan Rios-Zertuche, Rodolfo LAAS-CNRS Toulouse France Faculty of Electrical Engineering Czech Technical University Prague Czech Republic Department of Mathematics and Statistics UiT The Arctic University of Norway Norway

In this article, we tackle the problem of the existence of a gap corresponding to Young measure relaxations for state-constrained optimal control problems. We provide a counterexample proving that a gap may occur in a very regular setting, namely for a smooth controllable system state-constrained to the closed unit ball, provided that the Lagrangian density (i.e., the running cost) is non-convex in the control variables. The example is constructed in the setting of sub-Riemannian geometry with the core ingredient being an unusual admissible curve that exhibits a certain form of resistance to state-constrained approximation. Specifically, this curve cannot be approximated by neighboring admissible curves while obeying the state constraint due to the intricate nature of the dynamics near the boundary of the constraint set. Our example also presents an occupation measure relaxation gap. © 2025, The Authors. All rights reserved.

关键词： Controllability

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