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Feedback Mechanism-driven Mutation Reptile Search Algorithm for Optimizing Interpolation Developable Surfaces

Journal of Bionic engineering 2024年第1期21卷 527-571页

作者： Gang Hu Jiao Wang Xiaoni Zhu Muhammad Abbas Department of Applied Mathematics Xi'an University of TechnologyXi'an 710054China School of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an 710048China Department of Mathematics University of SargodhaSargodha 40100Pakistan

Curvature lines are special and important curves on *** is of great significance to construct developable surface interpolated on curvature lines in engineering *** this paper,the shape optimization of generalized cubic ball developable surface interpolated on the curvature line is studied by using the improved reptile search ***,based on the curvature line of generalized cubic ball curve with shape adjustable,this paper gives the construction method of SGC-Ball developable surface interpolated on the ***,the feedback mechanism,adaptive parameters and mutation strategy are introduced into the reptile search algorithm,and the Feedback mechanism-driven improved reptile search algorithm effectively improves the solving *** IEEE congress on evolutionary computation 2014,2017,2019 and four engineering design problems,the feedback mechanism-driven improved reptile search algorithm is compared with other representative methods,and the result indicates that the solution performance of the feedback mechanism-driven improved reptile search algorithm is *** last,taking the minimum energy as the evaluation index,the shape optimization model of SGC-Ball interpolation developable surface is *** developable surface with the minimum energy is achieved with the help of the feedback mechanism-driven improved reptile search algorithm,and the comparison experiment verifies the superiority of the feedback mechanism-driven improved reptile search algorithm for the shape optimization problem.

关键词： Reptile search algorithm Feedback mechanism Adaptive parameter Mutation strategy SGC-Ball interpolation developable surface Shape optimization

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Towards end-to-end structure determination from x-ray diffraction data using deep learning

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npj Computational Materials 2024年第1期10卷 1048-1059页

作者： Gabe Guo Judah Goldfeder Ling Lan Aniv Ray Albert Hanming Yang Boyuan Chen Simon J.L.Billinge Hod Lipson Department of Computer Science Columbia UniversityNew YorkNY10027USA Department of Applied Physics and Applied Mathematics Columbia UniversityNew YorkNY10027USA Department of Mechanical Engineering and Materials Science Duke UniversityDurhamNC27708USA Department of Mechanical Engineering Columbia UniversityNew YorkNY10027USA

Powder crystallography is the experimental science of determining the structure of molecules provided in crystalline-powder form,by analyzing their x-ray diffraction(XRD)*** many materials are readily available as crystalline powder,powder crystallography is of growing usefulness to many ***,powder crystallography does not have an analytically known solution,and therefore the structural inference typically involves a laborious process of iterative design,structural refinement,and domain knowledge of skilled experts.A key obstacle to fully automating the inference process computationally has been formulating the problem in an end-to-end quantitative form that is suitable for machine learning,while capturing the ambiguities around molecule orientation,symmetries,and reconstruction *** we present an ML approach for structure determination from powder diffraction *** works by estimating the electron density in a unit cell using a variational coordinate-based deep neural *** demonstrate the approach on computed powder x-ray diffraction(PXRD),along with partial chemical composition information,as *** evaluated on theoretically simulated data for the cubic and trigonal crystal systems,the system achieves up to 93.4%average similarity(as measured by structural similarity index)with the ground truth on unseen materials,both with known and partially-known chemical composition information,showing great promise for successful structure solution even from degraded and incomplete input *** approach does not presuppose a crystalline structure and the approach are readily extended to other situations such as nanomaterials and textured samples,paving the way to reconstruction of yet unresolved nanostructures.

关键词： structure powder crystalline

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Propulsion of a three-sphere microrobot in a porous medium

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Physical Review E 2024年第6期109卷 065106-065106页

作者： Chih-Tang Liao Andrew Lemus Ali Gürbüz Alan C. H. Tsang On Shun Pak Abdallah Daddi-Moussa-Ider Department of Mechanical Engineering Department of Applied Mathematics School of Mathematics and Statistics

Microorganisms and synthetic microswimmers often encounter complex environments consisting of networks of obstacles embedded into viscous fluids. Such settings include biological media, such as mucus with filamentous networks, as well as environmental scenarios, including wet soil and aquifers. A fundamental question in studying their locomotion is how the impermeability of these porous media impacts their propulsion performance compared with the case of that in a purely viscous fluid. Previous studies showed that the additional resistance due to the embedded obstacles leads to an enhanced propulsion of different types of swimmers, including undulatory swimmers, helical swimmers, and squirmers. In this paper, we employ a canonical three-sphere swimmer model to probe the impact of propulsion in porous media. The Brinkman equation is utilized to model a sparse network of stationary obstacles embedded into an incompressible Newtonian liquid. We present both a far-field theory and numerical simulations to characterize the propulsion performance of the swimmer in such porous media. In contrast to enhanced propulsion observed in other swimmer models, our results reveal that both the propulsion speed and efficiency of the three-sphere swimmer are largely reduced by the impermeability of the porous medium. We attribute the substantial reduction in propulsion performance to the screened hydrodynamic interactions among the spheres due to the more rapid spatial decays of flows in Brinkman media. These results highlight how enhanced or hindered propulsion in porous media is largely dependent on individual propulsion mechanisms. The specific example and physical insights provided here may guide the design of synthetic microswimmers for effective locomotion in porous media in their potential biological and environmental applications.

关键词： Microswimmers

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Data-driven discovery and extrapolation of parameterized pattern-forming dynamics

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Physical Review Research 2023年第4期5卷 L042017-L042017页

作者： Zachary G. Nicolaou Guanyu Huo Yihui Chen Steven L. Brunton J. Nathan Kutz Department of Applied Mathematics University of Washington Seattle Washington 98195 USA Department of Mechanical Engineering University of Washington Seattle Washington 98195 USA

Pattern-forming systems can exhibit a diverse array of complex behaviors as external parameters are varied, enabling a variety of useful functions in biological and engineered systems. First-principles derivations of the underlying transitions can be characterized using bifurcation theory on model systems whose governing equations are known. In contrast, data-driven methods for more complicated and realistic systems whose governing evolution dynamics are unknown have only recently been developed. Here, we develop a data-driven approach, the sparse identification for nonlinear dynamics with control parameters (SINDyCP), to discover dynamics for systems with adjustable control parameters, such as an external driving strength. We demonstrate the method on systems of varying complexity, ranging from discrete maps to systems of partial differential equations. To mitigate the impact of measurement noise, we also develop a weak formulation of SINDyCP and assess its performance on noisy data. We demonstrate applications including the discovery of universal pattern-formation equations, and their bifurcation dependencies, directly from data accessible from experiments and the extrapolation of predictions beyond the weakly nonlinear regime near the onset of an instability.

关键词： Bifurcations Control theory Pattern formation Spatiotemporal chaos Data analysis Machine learning

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A dive into spectral inference networks: improved algorithms for self-supervised learning of continuous spectral representations

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applied mathematics and Mechanics(English Edition) 2023年第7期44卷 1199-1224页

作者： J.WU S.F.WANG P.PERDIKARIS Graduate Group in Applied Mathematics and Computational Science University of Pennsylvania PhiladelphiaPA 19104U.S.A. Department of Mechanical Engineering and Applied Mechanics University of Pennsylvania PhiladelphiaPA 19104U.S.A.

We propose a self-supervising learning framework for finding the dominant eigenfunction-eigenvalue pairs of linear and self-adjoint *** represent target eigenfunctions with coordinate-based neural networks and employ the Fourier positional encodings to enable the approximation of high-frequency *** formulate a self-supervised training objective for spectral learning and propose a novel regularization mechanism to ensure that the network finds the exact eigenfunctions instead of a space spanned by the ***,we investigate the effect of weight normalization as a mechanism to alleviate the risk of recovering linear dependent modes,allowing us to accurately recover a large number of *** effectiveness of our methods is demonstrated across a collection of representative benchmarks including both local and non-local diffusion operators,as well as high-dimensional time-series data from a video *** results indicate that the present algorithm can outperform competing approaches in terms of both approximation accuracy and computational cost.

关键词： spectral learning partial differential equation(PDE) neural network slow features analysis

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Machine learning potential assisted exploration of complex defect potential energy surfaces

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npj Computational Materials 2024年第1期10卷 3017-3023页

作者： Chao Jiang Chris A.Marianetti Marat Khafizov David H.Hurley Computational Mechanics and Materials Department Idaho National LaboratoryIdaho FallsID 83415USA Department of Applied Physics and Applied Mathematics Columbia UniversityNew YorkNY 10027USA Department of Mechanical and Aerospace Engineering The Ohio State UniversityColumbusOH 43210USA Materials Science and Engineering Department Idaho National LaboratoryIdaho FallsID 83415USA

Atomic-scale defects generated in materials under both equilibrium and irradiation conditions can significantly impact their physical and mechanical *** the energetically most favorable ground-state configurations of these defects is an important step towards the fundamental understanding of their influence on the performance of materials ranging from photovoltaics to advanced nuclear ***,using fluorite-structured thorium dioxide(ThO_(2))as an exemplar,we demonstrate how density functional theory and machine learning interatomic potential can be synergistically combined into a powerful tool that enables exhaustive exploration of the large configuration spaces of small point defect *** study leads to several unexpected discoveries,including defect polymorphism and ground-state structures that defy our physical *** physical origins of these unexpected findings are elucidated using a local cluster expansion model developed in this work.

关键词： properties defect potential

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Fuzzy Game Approach Network Data Envelopment Analysis Models for the Waste Management Performance Evaluation

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International Journal of Fuzzy Systems 2023年第8期25卷 3193-3203页

作者： Liu, F.-B. Hu, C.-F. Department of Mechanical and Automation Engineering I-Shou University Kaohsiung City Taiwan Department of Applied Mathematics National Chiayi University Chiayi City Taiwan

Measuring the performance of national wastes is essential for ensuing the environmental protection and moving toward the circular economy objective. To cope with the uncertainty involving in many circular indicators, this study first proposed a fuzzy game approach network data envelopment analysis model for the waste management evaluation. The proposed model considers maximizing the potential joint efficiencies of the production and recycling processes simultaneously from the centralized control and circular economy perspective. A real-case study on assessing the waste management performance of European Union countries is provided. The factor efficiency analysis and associated ranks of the process efficiencies provide a guidance for identifying the factor dominance in the production and recycling processes. A comparison of the proposed method with other approaches is also included. Our results provide the European Union policy makers a valuable information to move waste management up the European Union waste hierarchy by allowing reusing, recycling, and recovering energy from the waste. © 2023, The Author(s) under exclusive licence to Taiwan Fuzzy Systems Association.

关键词： Uncertainty analysis

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MULTIOBJECTIVE OPTIMIZATION OF CASCADE REFRIGERATION SYSTEM USING NH3-CO2 AND NH3-N2O REFRIGERANT PAIRS

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International Journal of Energy for a Clean Environment 2023年第3期24卷 27-40页

作者： Singh, Kaushalendra Kumar Kumar, Rajesh Gupta, Anjana Department of Mechanical Engineering Delhi Technological University Delhi India Department of Mechanical Engineering G L Bajaj Institute of Technology and Management UP Greater Noida India Department of Applied Mathematics Delhi Technological University Delhi India

In this paper a comparative analysis based on multiobjective optimization of a cascade refrigeration system using NH3-CO2 and NH3-N2O refrigerant pairs has been done. Exergetic effciciency and overall cost rate have been taken as the two conflicting objective functions, and evaporator temperature, condenser temperature, LTC condenser temperature, and cascade heat exchanger temperature difference are the four design variables. The optimization work has been carried out using genetic algorithm, which results in a nondominated optimal solution represented in the form of pareto-optimal curve, and the technique for order performance by similarity to ideal solution (TOPSIS) method is used to select a unique solution. The results show that NH3-N2O is a better alternative as compared to NH3-CO2 refrigerant pair from a multiobjective optimization point of view. The corresponding optimal operating conditions have also been suggested for both the refrigerant pairs. © 2023 by Begell House, Inc.

关键词： Multiobjective optimization

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An Investigation on mechanical and Sliding Wear Properties of Titanium Oxide-Basalt Fiber-Based Hybrid PLA Composites Using Gray-Taguchi Approach

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Journal of The Institution of Engineers (India): Series D 2024年第3期105卷 1515-1525页

作者： Kumar, Sandeep Gangil, Brijesh Ranakoti, Lalit Bhandari, Prabhakar Gupta, Deepak Gupta, Manoj Kumar Department of Mechanical Engineering School of Engineering and Technology HNBGU Pauri Garhwal Uttarakhand Srinagar246174 India Department of Mechanical Engineering Graphic Era Deemed to Be University Uttarakhand Clementon Dehradun248002 India Department of Mechanical Engineering School of Engineering and Technology K. R. Mangalam University Haryana Gurugram122103 India Department of Mathematics Applied Sciences and Humanities Faculty of Engineering and Technology University of Lucknow Lucknow India

In the present study, the influence of titanium oxide (TiO2) nano-filler was investigated for the mechanical and sliding wear properties of basalt–PLA hybrid composites. The TiO2 in the form of nano-filler was hybridized at different weight percent (0, 3, 6, and 9 wt. %) while keeping the basalt fiber weight percentage is fixed at 10 wt. % in all composition of PLA composites. After performing the testing of specimen, observation revealed that both tensile and flexural strength increased at lower percentage of TiO2 content i.e., from 0 to 6 wt. %. But, at higher loading i.e., at 9 wt. % of TiO2, the same decreased owing to uneven distribution and particle agglomeration. Moderate improvement was observed in the hardness of composites with an increase in the nano-fillers content, and the highest value for the same was obtained as 30.22 Hv at 9 wt. % TiO2 reinforcement. Sliding wear measurement was carried out by using Taguchi (L16) orthogonal arrays considering various parameters viz: sliding velocities (2–5 m/s), TiO2 content (0–9 wt. %), and normal load (10–40N). Further, Gray relational analysis was used for analyzing the impact of control parameters on the multiple output responses (mechanical and specific wear rate) suggesting the optimum process parameter for the present study as sliding velocity (2 m/s), TiO2 content (6 wt. %), and normal load (40N). Scanning electron micrographs (SEM) were utilized for the examination of wear mechanism under the assumed conditions that support the optimum findings. © The Institution of Engineers (India) 2023.

关键词： Titanium dioxide

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Deciphering of solvent fraction, thermal relaxation and cubic autocatalysis in unsteady nonlinear radiative ternary nanoliquid flow over a slow rotating disk

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Multiscale and Multidisciplinary Modeling, Experiments and Design 2025年第6期8卷 1-15页

作者： Kumar, Thanesh Deevi Reddy, Prabhakara Reddy Reddy, Anitha Deevi Remidi, Srinivas Chohan, Jasgurpreet Singh Kedia, Ankit Mathematics and Computing Skills Unit University of Technology and Applied Sciences - Nizwa Nizwa Oman School of Mechanical Engineering Rayat Bahra University Mohali India Faculty of Engineering Sohar University Sohar Oman Department of Mechanical and Aerospace Engineering NIMS Institute of Engineering & Technology NIMS University Rajasthan Jaipur India

The present study explores the consequence of homogeneous–heterogeneous chemical reactions on the unsteady flow of Boger ternary nanoliquid via a slow rotating disk with the porous medium, suction, and non-linear thermal radiation. Additionally, the temperature equation is modelled using the Cattaneo–Christov heat flux theory. Fluid flow past revolving disk concepts are utilized in various technical applications, including gas turbine engines, flywheels, gears, and brakes. The analysis considers titanium dioxide, cobalt ferrite, and magnesium oxide nanoparticles that are suspended in water. Using similarity variables, the governing partial differential equations (PDEs) are converted to dimensionless ordinary differential equations (ODEs). Further, the resultant ODEs are numerically solved using the finite difference method (FDM). The impact of several parameters on the velocity, thermal, and concentration profiles are depicted with the graphical illustrations. The velocity profiles decline as the ratio of relaxation time and porous parameter values rise. An increase in the solvent fraction parameter enhances the velocity profiles. The velocity profiles diminish as the suction parameter increases. As the radiation parameter values increase, the temperature profile rises. The concentration profile diminishes as the intensity of the homogeneous and heterogeneous reaction parameters escalates. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.

关键词： Stream flow

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