The European Physical Journal Special Topics最新文献_第4页

Ternary hybrid nanofluid flow and heat transfer at a permeable stretching sheet with slip boundary conditions 具有滑移边界条件的渗透性拉伸片上的三元混合纳米流体流动与传热

The European Physical Journal Special Topics Pub Date : 2024-08-19 DOI: 10.1140/epjs/s11734-024-01295-z

K. Varatharaj, R. Tamizharasi, K. Vajravelu

{"title":"Ternary hybrid nanofluid flow and heat transfer at a permeable stretching sheet with slip boundary conditions","authors":"K. Varatharaj, R. Tamizharasi, K. Vajravelu","doi":"10.1140/epjs/s11734-024-01295-z","DOIUrl":"https://doi.org/10.1140/epjs/s11734-024-01295-z","url":null,"abstract":"This study investigates the optimization of heat transfer using a ternary hybrid nanofluid, an innovative advancement in nanofluid technology. The primary objective is to analyze the effects of first-order boundary slip conditions, thermal radiation, porous media, viscous dissipation, and Joule heating on the thermal dynamics of the nanofluid. The ternary hybrid nanofluid, consisting of silver (Ag), titanium dioxide ((TiO_2)), and alumina ((Al_2O_3)) nanoparticles suspended in water ((H_2O)), is selected for its potential to enhance heat transfer and thermal efficiency in various applications, including cooling systems, food processing, and refrigeration. The research employs magneto-hydrodynamics combined with the ternary hybrid nanofluid to improve energy and mass transfer processes. Through a similarity transformation, the governing equations are converted into a set of nonlinear ordinary differential equations, which are then solved numerically using the shooting technique integrated with MATLAB. Graphical representations and tabulated data illustrate the impact of different parameters on velocity and temperature fields, skin-friction coefficient, and local Nusselt number. Key findings indicate that increased values of radiation and magnetic parameters result in a thicker thermal boundary layer. The study also reveals that the velocity of the hybrid nanofluid can be effectively controlled by adjusting the magnetic field, porous media, and nanoparticle volume fraction. Notably, the ternary hybrid nanofluid ((Ag-Al_2O_3-TiO_2/H_2O)) demonstrates superior performance compared to hybrid nanofluids with a single component ((Ag-Al_2O_3/H_2O)). Comparisons with pre-existing data show favorable alignment, underscoring the robustness of the results. This research has significant implications for engineering, healthcare, and biomedical technology.","PeriodicalId":501403,"journal":{"name":"The European Physical Journal Special Topics","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A U-shaped CNN with type-2 fuzzy pooling layer and dynamical feature extraction for colorectal polyp applications 带有 2 型模糊池层和动态特征提取的 U 型 CNN 在结直肠息肉应用中的应用

The European Physical Journal Special Topics Pub Date : 2024-08-19 DOI: 10.1140/epjs/s11734-024-01298-w

S. B. Tharun, S. Jagatheswari

引用次数: 0

Observer-based control for consensus tracking of non-linear synchronous generators system using sliding mode method and a radial basis function neural network 利用滑模方法和径向基函数神经网络，为非线性同步发电机系统的一致跟踪提供基于观测器的控制

The European Physical Journal Special Topics Pub Date : 2024-08-19 DOI: 10.1140/epjs/s11734-024-01281-5

Alireza Sharifi, Amin Sharafian, Qian Ai

{"title":"Observer-based control for consensus tracking of non-linear synchronous generators system using sliding mode method and a radial basis function neural network","authors":"Alireza Sharifi, Amin Sharafian, Qian Ai","doi":"10.1140/epjs/s11734-024-01281-5","DOIUrl":"https://doi.org/10.1140/epjs/s11734-024-01281-5","url":null,"abstract":"This paper presents a novel neuro-sliding mode observer-based control strategy for addressing disturbances, model uncertainties, and unmodeled dynamics in practical multi-agent systems (MAS). The focus is on achieving consensus tracking in non-linear MAS, specifically in the context of synchronous generators. A distributed protocol based on sliding mode approach is proposed to handle unknown model structures and parameters of follower agents influenced by the dynamics of synchronous generators. To achieve consensus tracking under these conditions, a hybrid radial basis function (RBF) neural network is employed to identify the unmodeled dynamics of the follower agents. The neural network’s update law algorithm is adjusted using the errors from both the observer and the controller. The stability of the proposed method is guaranteed by employing Lyapunov theory, ensuring that the consensus error and the error between the states of the consensus error dynamic and its estimator asymptotically converge to a neighborhood of zero. To validate the theoretical results, Matlab simulations are conducted to assess the effectiveness of the proposed approach, providing evidence of its capability and practical applicability.","PeriodicalId":501403,"journal":{"name":"The European Physical Journal Special Topics","volume":"307 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimal control analysis of fractional order delayed SIQR model for COVID-19 COVID-19 分阶延迟 SIQR 模型的优化控制分析

The European Physical Journal Special Topics Pub Date : 2024-08-19 DOI: 10.1140/epjs/s11734-024-01294-0

S. Suganya, V. Parthiban

引用次数: 0

Machine learning in experimental neutrino physics 中微子物理实验中的机器学习

The European Physical Journal Special Topics Pub Date : 2024-08-19 DOI: 10.1140/epjs/s11734-024-01280-6

N. Poonthottathil

引用次数: 0

Reservoir computing for predicting pm 2.5 dynamics in a metropolis 预测大都市 pm 2.5 动态的水库计算

The European Physical Journal Special Topics Pub Date : 2024-08-19 DOI: 10.1140/epjs/s11734-024-01287-z

Aleksandr Sergeev, Andrey Shichkin, Alexander Buevich, Elena Baglaeva

{"title":"Reservoir computing for predicting pm 2.5 dynamics in a metropolis","authors":"Aleksandr Sergeev, Andrey Shichkin, Alexander Buevich, Elena Baglaeva","doi":"10.1140/epjs/s11734-024-01287-z","DOIUrl":"https://doi.org/10.1140/epjs/s11734-024-01287-z","url":null,"abstract":"Recently, researchers have used various methods for time-series forecasting based on artificial neural network models. Among these approaches, one of the most effective ones is the Echo State Network (ESN). An ESN is a variant of recurrent neural networks (RNNs) that are used in environmental studies. In this work, we propose models to predict the dynamics of dust particles (PM 2.5) using reservoir computing. The model was based on data on the content of PM 2.5 obtained in Seoul, Republic of Korea, collected between January 2017 and August 2017. Hourly data for this period were averaged over a 6-h interval to reduce variability in the source data. For training, 800 samples of the time series were selected; for the test set, 50 samples (part 1 of the work) and 100 samples (part 2 of the work) were used. Prediction accuracy was assessed using several accuracy indices and a Taylor diagram. The application of the proposed approach demonstrated the effectiveness of reservoir calculations for predicting dust content in megacities. The accuracy and the quality of the models improved from 9 to 67%, depending on the evaluation indicator. It was also found that the accuracy of the model decreased when the predicted time interval exceeded 6% of the training time interval.","PeriodicalId":501403,"journal":{"name":"The European Physical Journal Special Topics","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Quantum genetic algorithm-based memory state feedback control for T–S fuzzy system 基于量子遗传算法的 T-S 模糊系统记忆状态反馈控制

The European Physical Journal Special Topics Pub Date : 2024-08-16 DOI: 10.1140/epjs/s11734-024-01293-1

K. Sanjay, R. Vijay Aravind, P. Balasubramaniam

引用次数: 0

Chaos, synchronization, and emergent behaviors in memristive hopfield networks: bi-neuron and regular topology analysis 记忆跳场网络中的混沌、同步和突发行为：双神经元和规则拓扑分析

The European Physical Journal Special Topics Pub Date : 2024-08-16 DOI: 10.1140/epjs/s11734-024-01297-x

Bertrand Frederick Boui A Boya, Sishu Shankar Muni, José Luis Echenausía-Monroy, Jacques Kengne

{"title":"Chaos, synchronization, and emergent behaviors in memristive hopfield networks: bi-neuron and regular topology analysis","authors":"Bertrand Frederick Boui A Boya, Sishu Shankar Muni, José Luis Echenausía-Monroy, Jacques Kengne","doi":"10.1140/epjs/s11734-024-01297-x","DOIUrl":"https://doi.org/10.1140/epjs/s11734-024-01297-x","url":null,"abstract":"This paper investigates the dynamics of a Hopfield inertial bi-neuron with double memristive synaptic weights. The dynamical behavior of the system is investigated with both numerical and analytical studies to characterize the proposed model, which has up to thirty-nine equilibrium points. In this model, numerical simulations show many behaviors such as chaos, antimonotonicity of periodic and chaotic bubbles, and bursting oscillation (regular and irregular). Moreover, this system showed multiple coexistence of up to six different attractors, with the attractor basins confirming this phenomenon. A ring and star network of Hopfield neurons was also considered. We found interesting spatio-temporal regimes, including chimera and cluster states. Moreover, we showed a striking coexistence of synchronized, chimera, and cluster states in the network. The integration of multiple memristors in neural network systems holds promise for improving our understanding of the brain and developing more sophisticated artificial intelligence technologies that can better mimic human cognitive abilities.","PeriodicalId":501403,"journal":{"name":"The European Physical Journal Special Topics","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Group theory in physics: an introduction with mathematica 物理学中的群论：Mathematica 入门

The European Physical Journal Special Topics Pub Date : 2024-08-13 DOI: 10.1140/epjs/s11734-024-01245-9

Balasubramanian Ananthanarayan, Souradeep Das, Amitabha Lahiri, Suhas Sheikh, Sarthak Talukdar

引用次数: 0

Long short-term memory and Kalman filter with attention mechanism as approach for covariance shift problem in water leakage 长短期记忆和带有注意力机制的卡尔曼滤波器作为解决漏水协方差偏移问题的方法

The European Physical Journal Special Topics Pub Date : 2024-08-13 DOI: 10.1140/epjs/s11734-024-01285-1

C. Pandian, P. J. A. Alphonse

{"title":"Long short-term memory and Kalman filter with attention mechanism as approach for covariance shift problem in water leakage","authors":"C. Pandian, P. J. A. Alphonse","doi":"10.1140/epjs/s11734-024-01285-1","DOIUrl":"https://doi.org/10.1140/epjs/s11734-024-01285-1","url":null,"abstract":"Urban water systems continue to face a major problem with water leakage, which results in substantial waste, shortages, damage to infrastructure, and monetary losses. While deep learning models have been effective in locating and identifying leaks, overfitting may result from their complexity over several training epochs. By including an attention mechanism, prominent features are given priority, improving model performance without compromising simplicity. Furthermore, layer normalization reduces problems in long short-term memory networks such as exploding gradients. Notable F1-scores are achieved by the proposed approach, demonstrating strong performance in both leak detection and localization tasks. Performance analysis under three different conditions for leak detection task such as source adaptation, target adaptation and adversarial simulation have shown an increase with scores of 91.59, 86.25 and 82.51 yielding 8.2%, 8.7% and 6.8% of improvement in F1-score, respectively. Similarly, performance analysis under three different conditions for leak localization task such as source adaptation, target adaptation and adversarial simulation has shown an increase with scores of 89.86, 84.39 and 80.77, yielding 7.4%, 8.5% and 8.6% of improvement in F1-score, respectively. Also, analysis using Wasserstein distance indicates reduced covariate shift through significant increase in accuracy (around 6.5%–9.5%, respectively), which is essential for adapting to varying water demand scenarios. The effectiveness of the proposed approach in urban water management is underscored by these results, emphasizing its potential for enhancing resource conservation and infrastructure sustainability.","PeriodicalId":501403,"journal":{"name":"The European Physical Journal Special Topics","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0