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AI-Driven Energy Optimization in UAV-Assisted Routing for Enhanced Wireless Sensor Networks Performance

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Computers, Materials & Continua 2024年第9期80卷 4085-4110页

作者： Syed Kamran Haider Abbas Ahmed Noman Mujeeb Khan Ali Nauman Sung Won Kim college of Internet of Things(iot)engineering Hohai UniversityChangzhou213001China Department of Electrical and Electronics engineering Beaconhouse International CollegeIslamabad44000Pakistan School of Computer Science and engineering Yeungnam UniversityGyeongsan38428Republic of Korea

In recent advancements within wireless sensor networks(WSN),the deployment of unmanned aerial vehicles(UAVs)has emerged as a groundbreaking strategy for enhancing routing efficiency and overall network *** research introduces a sophisticated framework,driven by computational intelligence,that merges clustering techniques with UAV mobility to refine routing strategies in *** proposed approach divides the sensor field into distinct sectors and implements a novel weighting system for the selection of cluster heads(CHs).This system is primarily aimed at reducing energy consumption through meticulously planned routing and path *** a greedy algorithm for inter-cluster dialogue,our framework orchestrates CHs into an efficient communication *** comparative analysis,the proposed model demonstrates a marked improvement over traditional methods such as the cluster chain mobile agent routing(CCMAR)and the energy-efficient cluster-based dynamic algorithms(ECCRA).Specifically,it showcases an impressive 15%increase in energy conservation and a 20%reduction in data transmission time,highlighting its advanced ***,this paper investigates the impact of various network parameters on the efficiency and robustness of the WSN,emphasizing the vital role of sophisticated computational strategies in optimizing network operations.

关键词： UAV trajectory clustering next-generation wireless sensor network(NGWSN) energy efficiency mobile sink

Improvement of Microstructure and Mechanical Properties of Rapid Cooling Friction Stir-welded A1050 Pure Aluminum

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Journal of Wuhan university of Technology(Materials Science) 2024年第1期39卷 134-141页

作者：许楠 LIU Lutao SONG Qining ZHAO Jianhua BAO Yefeng college of Materials Science and engineering Hohai UniversityChangzhou 213200China

Two-mm thick A1050 pure aluminum plates were successfully joined by conventional and rapid cooling friction stir welding(FSW), respectively. The microstructure and mechanical properties of the welded joints were investigated by electron backscatter diffraction characterization, Vickers hardness measurements, and tensile testing. The results showed that liquid CO_(2) coolant significantly reduced the peak temperature and increased the cooling rate, so the rapidly cooled FSW joint exhibited fine grains with a large number of dislocations. The grain refinement mechanism of the FSW A1050 pure aluminum joint was primarily attributed to the combined effects of continuous dynamic recrystallization, grain subdivision, and geometric dynamic recrystallization. Compared with conventional FSW, the yield strength, ultimate tensile strength, and fracture elongation of rapidly cooled FSW joint were significantly enhanced, and the welding efficiency was increased from 80% to 93%. The enhanced mechanical properties and improved synergy of strength and ductility were obtained due to the increased dislocation density and remarkable grain refinement. The wear of the tool can produce several WC particles retained in the joint, and the contribution of second phase strengthening to the enhanced strength should not be ignored.

关键词： aluminum alloy friction stir welding recrystallization microstructure mechanical properties

Robust Forecasting-Aided State Estimation Considering Uncertainty in Distribution System

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1632-1641页

作者： Dongchen Hou Yonghui Sun Linchuang Zhang Sen Wang college of Energy and Electrical engineering Hohai UniversityNanjing 210098China

With the development of the smart grid,the distribution system operation conditions become more complex and ***,due to the influence of observation outliers and uncertain noise statistics,it is more difficult to grasp the dynamic operation characteristics of distribution *** order to address these problems,by using projection statistics and the noise covariance updating technology based on the Sage-Husa noise estimator,for distribution power system with outliers and uncertain noise statistics,a robust adaptive cubature Kalman filter forecasting-aided state estimation method is proposed based on generalized-maximum likelihood type ***,an adaptive strategy,which can enhance the filtering accuracy under normal conditions,is *** the simulation part,the branch parameters and node load parameters of the test system are appropriately modified to simulate the asymmetry of the three-phase branch parameters and the asymmetry of the three-phase ***,through simulation experiments on the improved test system,it is verified that the robust forecasting-aided state estimation method,presented in this paper,can effectively perceive the actual operating state of the distribution network in different simulation scenarios.

关键词： Cubature Kalman filter distribution power system forecasting-aided state estimation projection statistics

Fluid-structure interaction simulation of dynamic response and wake of floating offshore wind turbine considering tower shadow effect

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Acta Mechanica Sinica 2024年第8期40卷 67-84页

作者： Songyang Liu Zhiqiang Xin Lei Wang Zhiming Cai college of Mechanics and engineering Science HoHai UniversityNanjing211100China

The comprehensive numerical simulation of the tower shadow effect on floating offshore wind turbines(FOWTs),an area less explored compared to fixed-bottom wind turbines,is presented in this *** atmospheric boundary layer inflow and the joint north sea wave project random wave are used as the operating conditions for *** combination of computational fluid dynamics(CFD)software simulator for wind farm applications and turbine simulation tool OpenFAST is used to implement fluid-structure interaction *** output power,platform motion,wake velocity deficit and vortex structures are analyzed to reveal the influence of the tower shadow effect on the *** results indicate that due to the fluctuation caused by the turbulent wind and the floating platform motion,the tower shadow effect of FOWT is less significant for its periodic power decay than that of fixed-bottom wind *** according to the velocity deficit analysis,the influence area of the tower shadow effect on the wake is mainly in the near wake region.

关键词： Floating offshore wind turbine Tower shadow effect Atmospheric boundary layer inflow JONSWAP wave Wind turbine wake

Numerical simulation of transient characteristics in a bulb turbine during the load rejection process

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Journal of Hydrodynamics 2024年第1期36卷 170-183页

作者： Yue Lu Yu-quan Zhang Zhong-wei He Yuan Zheng college of Water Conservancy and Hydropower engineering Hohai UniversityNanjing210098China college of Energy and Electrical engineering Hohai UniversityNanjing210098China Huadong engineering Corporation Ltd. Hangzhou311122China

To evaluate the safety of the bulb tubular turbine,the dynamic hydraulic characteristics of a hydropower station system during the load rejection process are studied through numerical simulations and a prototype *** the developed model,a dynamic grid technology(DGT)controls the closure of the guide vane and the blade,whilst the moment balance equation and the user-defined function(UDF)provide the runner’s rotation *** 3-D transient simulation method can well predict the rotation speed and mass flow curves in the state of load *** simulation outcomes of the system performance are basically consistent with the measurement data of the *** observed,the runner is subjected to the reversely increased torque and axial force,the system is in a braking phase,and the maximum speed peaks at 144.6%of the rated ***,the internal flow of the runner is greatly affected by the closure of the guide vane,and the draft tube forms an eccentric spiral vortex *** breaks downstream,aggravating the instability of the draft ***,the transient characteristics span for the first five seconds,demonstrating the importance of establishing an efficient governing *** obtained results are useful for designing the turbine’s flow channel with a double regulating function and comprehending the turbine’s transient characteristics.

关键词： Bulb tubular turbine load rejection numerical simulation dynamic grid prototype test

Synthesis of NO by rotating sliding arc discharge reactor with conical-spiral electrodes

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Plasma Science and Technology 2024年第9期26卷 97-108页

作者： Bingyan CHEN Qi LIU Xu LI Chunyang ZHANG Xiangbin GUO Qingzhou YU Zhicheng TANG Xiang HE Wei SU Yongfeng JIANG college of Mechanics and engineering Science Hohai UniversityNanjing 211100People’s Republic of China college of Mechanical and Electrical engineering Hohai UniversityChangzhou 213200People’s Republic of China college of Materials Science and engineering Hohai UniversityChangzhou 213200People’s Republic of China college of Information Science and engineering Hohai UniversityChangzhou 213200People’s Republic of China

The present work investigates the potential applications of nitrogen oxides(NO_(x)),particularly nitric oxide(NO)and nitrogen dioxide(NO_(2)),generated through discharge plasma in diverse sectors such as medicine,nitrogen fixation,energy,and environmental *** this study,a rotating sliding arc discharge reactor was initially employed to produce high concentrations of gaseous NO_(x),followed by the utilization of a molybdenum wire redox reactor for NO_(2)-to-NO *** outcomes reveal that the discharge states and generations of NO_(x) are affected by varying parameters,including the applied energies,frequencies and airflow states(1.3-2.6 m/s are the laminar flow,2.6-5.2 m/s are the transition state,5.2-6.5 m/s are the turbulent flow),and the concentrations of NO_(x) within the arc discharge are higher than that in the spark ***,the concentrations of NO,NO_(2) and NO_(x) gradually increased,and the concentration ratios of NO/NO_(2) and NO_(x)/NO_(2) decreased with increasing the applied energy for one cycle from 14.8 mJ to 24.3 ***,the concentrations of NO,NO_(2) and NO_(x) gradually decreased,and the concentration ratios of NO/NO_(2) and NO_(x)/NO_(2) first decreased and then increased with increasing the applied frequencies from 5.0 kHz to 9.0 ***,the concentrations of NO,NO_(2) and NO_(x) gradually decreased,and the concentration ratios of NO/NO_(2) and NO_(x)/NO_(2) first increased and then decreased with increasing the air flow speeds from 1.3 m/s to 6.5 m/***,the concentrations of NO increased and NO_(2) decreased with increasing temperature from 25℃ to 400℃ using molybdenum *** findings provide experimental support for the application of plasma in the fields of medicine,nitrogen fixation,energy and environmental protection.

关键词： rotating sliding arc discharge NO_(x) synthesis of NO redox reaction

Microscopic ensemble bootstrap in phase space

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Communications in Theoretical Physics 2024年第6期76卷 72-76页

作者： Yu Zhang college of Mechanics and engineering Science Hohai UniversityNanjing 211100China

The bootstrap method which has been studied under many quantum mechanical models turns out to be feasible in microcanonical ensembles as *** the approach of Nakayama(2022 ***.A 372250054)produces a sector when energy is negative,in this paper we report a method that has stronger constraints and results in a smaller *** also study other models to demonstrate the effectiveness of our method.

关键词： numerical bootstrap microcanonical ensemble Poisson bracket bootstrap oscillator

An analytical transient coal permeability model:Sorption non-equilibrium index-based swelling switch

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Journal of Rock Mechanics and Geotechnical engineering 2024年第4期16卷 1175-1191页

作者： Xingxing Liu Jishan Liu Liang Chen Jinchang Sheng Huimin Wang college of Civil and Transportation engineering Hohai UniversityNanjing210098China School of engineering The University of Western Australia35 Stirling HighwayCrawleyWA6009Australia college of Water Conservancy and Hydropower engineering Hohai UniversityNanjing210098China

Long-term permeability experiments have indicated that sorption-induced swelling can switch from internal to bulk depending on the evolutive sorption ***,this sorption swelling switch mechanism has not been considered in current analytical permeability *** study introduces a normalized sorption non-equilibrium index(SNEI)to characterize the sorption status,quantify the dynamical variations of matrix swelling accumulation and internal swelling partition,and formulate the sorption swelling switch *** incorporation of this index into the extended total effective stress concept leads to an analytical transient coal permeability *** results show that the sorption swelling switch itself results in the permeability switch under stress-constrained conditions,while the confined bulk swelling suppresses the permeability recovery to the continuous reduction under displacement-constrained *** verifications show that current experimental observations correspond to the early stages of the transient process,and they could be extended to the whole process with these *** study demonstrates the importance of the sorption swelling switch in determining permeability evolution using simple boundary *** provides new insights into experimentally revealing the sorption swelling switch in the future,and underscores the requirement of a rigorous model for complex coupled processes in large-scale coal seams.

关键词： Coal permeability Sorption swelling switch Sorption non-equilibrium Boundary conditions

Customizable multifunctional metasurface absorber based on bidirectional deep neural networks covering the quasi-entire terahertz band

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Chinese Optics Letters 2024年第6期22卷 182-190页

作者： Zhipeng Ding Wei Su Lipeng’an Ye Yuanhang Zhou Wenlong Li Riaz Ali Bin Tang Hongbing Yao college of Mechanics and engineering Science Hohai UniversityNanjing 211100China School of Microelectronics and Control engineering Changzhou UniversityChangzhou 213164China

In this work, we propose a novel approach that combines a bidirectional deep neural network(BDNN) with a multifunctional metasurface absorber(MMA) for inverse design, which can effectively address the challenge of on-demand customization for absorbers. The inverse design of absorption peak frequencies can be achieved from 0.5 to 10 terahertz(THz), covering the quasi-entire THz band. Based on this, the BDNN is extended to broadband absorption, and the inverse design yields an MMA at the desired frequency. This work provides a broadly applicable approach to the custom design of multifunctional devices that can facilitate the evaluation and design of metasurfaces in electromagnetic absorption.

关键词： terahertz inverse design bidirectional deep neural network metasurface