检索结果-南通市图书馆

Chinese j.urnal of Electrical Engineering 2024年第1期10卷 1-2页

作者： Li j. Mei H. Li s. Tianj.n University China Tsinghua shenzhen International Graduate school China Lanzhou j.aotong University China

The rapid development of clean and renewable energy technologies represented by wind and solar energy,as well as the continuous growth of load demand,have put forward higher requirements for the safe operation of the power *** performance of power equipment based on traditional dielectric materials is often limited by various defects generated during molding,transportation,assembly,and operation,which cannot meet the reliability requirements of power systems in the new *** detection is an essential technical method in industrial development,which can detect and evaluate the defect and damage status of in-service equipment,key components,and materials without damaging the obj.ct.

关键词： service Application operation

Value Function Mechanism in WsNs-Based Mango Plantation Monitoring system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials and Continua 2024年第3期80卷 3733-3759页

作者： sung W.-T. Isa I.G.T. Hsiao s.-j. Department of Electrical Engineering National Chin-Yi University of Technology Taichung 411030 Taiwan Department of Informatics Management Politeknik Negeri Sriwijaya Palembang 30139 Indonesia Department of Information Technology Takming University of Science and Technology Taipei City 11451 Taiwan

Mango fruit is one of the main fruit commodities that contributes to Taiwan’s income. The implementation of technology is an alternative to increasing the quality and quantity of mango plantation product productivity. In this study, a Wireless sensor Networks (“WsNs”)-based intelligent mango plantation monitoring system will be developed that implements deep reinforcement learning (DRL) technology in carrying out prediction tasks based on three classifications: “optimal,” “sub-optimal,” or “not-optimal” conditions based on three parameters including humidity, temperature, and soil moisture. The key idea is how to provide a precise decision-making mechanism in the real-time monitoring system. A value function-based will be employed to perform DRL model called deep Q-network (DQN) which contributes in optimizing the future reward and performing the precise decision recommendation to the agent and system behavior. The WsNs experiment result indicates the system’s accuracy by capturing the real-time environment parameters is 98.39%. Meanwhile, the results of comparative accuracy model experiments of the proposed DQN, individual Q-learning, uniform coverage (UC), and Naïve Bayes classifier (NBC) are 97.60%, 95.30%, 96.50%, and 92.30%, respectively. From the results of the comparative experiment, it can be seen that the proposed DQN used in the study has the most optimal accuracy. Testing with 22 test scenarios for “optimal,” “sub-optimal,” and “not-optimal” conditions was carried out to ensure the system runs well in the real-world data. The accuracy percentage which is generated from the real-world data reaches 95.45%. From the results of the cost analysis, the system can provide a low-cost system compared to the conventional system. Copyright © 2024 The Authors. Published by Tech science Press.

关键词： deep Q-network (DQN) deep reinforcement learning (DRL) Intelligent monitoring system wireless sensor networks (WsNs)

Generalized polynomial chaos expansion by reanalysis using static condensation based on substructuring

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 819-836页

作者： D.LEE s.CHANG j.LEE Department of Automotive Engineering Hanyang UniversitySeoul 04763Republic of Korea school of Mechanical Engineering Chungnam National UniversityDaejeon 34134Republic of Korea Department of Mechanical Robotics and Energy EngineeringDongguk UniversitySeoul 04620Republic of Korea

This paper presents a new computational method for forward uncertainty quantification(UQ)analyses on large-scale structural systems in the presence of arbitrary and dependent random *** method consists of a generalized polynomial chaos expansion(GPCE)for statistical moment and reliability analyses associated with the stochastic output and a static reanalysis method to generate the input-output data *** the reanalysis,we employ substructuring for a structure to isolate its local regions that vary due to random *** allows for avoiding repeated computations of invariant substructures while generating the input-output data *** substructuring with static condensation further improves the computational efficiency of the reanalysis without losing ***,the GPCE with the static reanalysis method can achieve significant computational saving,thus mitigating the curse of dimensionality to some degree for UQ under high-dimensional *** numerical results obtained from a simple structure indicate that the proposed method for UQ produces accurate solutions more efficiently than the GPCE using full finite element analyses(FEAs).We also demonstrate the efficiency and scalability of the proposed method by executing UQ for a large-scale wing-box structure under ten-dimensional(all-dependent)random inputs.

关键词： forward uncertainty quantification(UQ) generalized polynomial chaos expansion(GPCE) static reanalysis method static condensation substructuring

seismogenic model of the 2023 MW5.5 Pingyuan earthquake in North China Plain and its tectonic implications

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Earthquake science 2024年第6期37卷 499-513页

作者： Wang s. Han L. Xie j. Fan L. Huang X. Bi j. Yang H. Fang L. Institute of Geophysics China Earthquake Administration Beijing 10081 China Tianj.n Earthquake Agency Tianjin 300201 China Earth system science Programme The Chinese University of Hong Kong Hong Kong Shatin 999077 China Beij.ng Baij.atuan Earth science National Observation and Research station Beijing 100095 China

The 6 August 2023 MW5.5 Pingyuan earthquake is the largest earthquake in the central North China Plain (NCP) over the past two decades. Due to the thick sedimentary cover, no corresponding active faults have been reported yet in the epicenter area. Thus, this earthquake presents a unique opportunity to delve into the buried active faults beneath the NCP. By integrating strong ground motion records, high-precision aftershock sequence relocation, and focal mechanism solutions, we gain insights into the seismotectonics of the Pingyuan earthquake. The aftershocks are clustered at depths ranging from 15 to 20 km and delineate a NE-sW trend, consistent with the distribution of ground motion records. A NE-sW nodal plane (226°) of the focal mechanism solutions is also derived from regional waveform inversion, suggesting that the mainshock was dominated by strike-slip motion with minor normal faulting component. Integrating regional geological data, we propose that an unrecognized fault between the NE-sW trending Gaotang and Lingxian-Yangxin faults is the seismogenic fault of this event. Based on the s-wave velocity structure beneath the NCP, this fault probably extends into the lower crust with a high angle. Considering the tectonic regime and stress state, we speculate that the interplay of shear strain between the Amurian and south China blocks and the hot upwelling magma from the subducted paleo Pacific flat slab significantly contributed to the generation of the Pingyuan earthquake. © 2024 The Authors

关键词： aftershock relocation focal mechanism North China Plain Pingyuan earthquake s-wave velocity structure

Influence of Formulation and Hot-Pressing Conditions on the Performance of Bio-Based Molasses Adhesive for Plywood

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

j.urnal of Renewable Materials 2024年第8期12卷 1383-1397页

作者： s.tiawan j. syahfitri A. Kusumah s.s. Hermawan D. sari R.K. Hakim L. Mardawati E. Lubis M.A.R. Research Center for Biomass and Bioproducts National Research and Innovation Agency Cibinong 16911 Indonesia Forest Product Department Faculty of Forestry and Environment IPB University Bogor 16680 Indonesia Department of Forest Products Faculty of Forestry Universitas Sumatera Utara Medan 20155 Indonesia Research Collaboration Center for Biomass and Biorefinery BRIN and Universitas Padjadjaran Bandung 40600 Indonesia Department of Agro-Industrial Technology Universitas Padjadjaran Bandung 40600 Indonesia

Molasses can serve as a natural adhesive for plywood and particleboard. However, several disadvantages remain, including lower dimensional stability and low bonding strength compared to other adhesives. Therefore, modifications are needed to use molasses as an adhesive for plywood. This research aims to improve bio-based molasses (MO) adhesive for plywood using citric acid (CA) adhesive. In addition, this research aims to analyze the effect of adding citric acid and to investigate the optimum hot-pressing temperature to produce the best quality plywood. In the first stage, the molasses and citric acid were combined in a ratio of 100:0, 75:25, 50:50, 25:75, 0:100 w/w%. Then, the second stage focuses on analyzing the influences of pressing temperature based on an optimum first stage. The research demonstrated that the addition of CA altered the gelation time, solid content, visc-osity, and pH of the molasses adhesives. In addition, the thermal properties of molasses adhesives were changed after mixing with citric acid. These phenomena indicate changes in characteristics, such as the curing of adhesive. Overall, the characteristics of plywood showed a steady improvement as the CA ratio increased but revealed a significant decline for the 25:75 MO-CA ratio. By raising the pressing temperature from 180°C to 200°C, the quality of plywood was effectively improved. The plywood that was bonded using adhesives with a 50:50 MO-CA ratio exhibited superior mechanical properties and improved dimensional stability compared to the plywood bonded solely with MO. Furthermore, the optimal mechanical and physical properties resulted in plywood bonded with a 50:50 MO-CA ratio when subj.cted to a pressing temperature of 200°C. The Thermal and FTIR measurements revealed that CA established ester bonds with both the MO and wood veneers. In conclusion, the mechanical characteristics of plywood were improved, while maintaining its excellent dimensional stability. © 2024 The Authors.

关键词： Citric acid composite molasses plywood pressing temperature

Background removal from global auroral images:Data-driven dayglow modeling

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2024年第1期8卷 247-257页

作者： A.Ohma M.Madelaire K.M.Laundal j.P.Reistad s.M.Hatch s.Gasparini s.j.Walker Birkeland Centre for space science Department of Physics and TechnologyUniversity of BergenBergenNorway

Global images of auroras obtained by cameras on spacecraft are a key tool for studying the near-Earth ***,the cameras are sensitive not only to auroral emissions produced by precipitating particles,but also to dayglow emissions produced by photoelectrons induced by *** emissions and scattered sunlight can contribute to the background *** fully utilize such images in space science,background contamination must be removed to isolate the auroral *** we outline a data-driven approach to modeling the background intensity in multiple images by formulating linear inverse problems based on B-splines and spherical *** approach is robust,flexible,and iteratively deselects outliers,such as auroral *** final model is smooth across the terminator and accounts for slow temporal variations and large-scale asymmetries in the *** demonstrate the model by using the three far ultraviolet cameras on the Imager for Magnetopause-to-Aurora Global Exploration(IMAGE)*** method can be applied to historical missions and is relevant for upcoming missions,such as the solar wind Magnetosphere Ionosphere Link Explorer(sMILE)mission.

关键词： aurora dayglow modeling global auroral images far ultraviolet images dayglow removal

Mathematical modeling and simulations of stress mitigation by coating polycrystalline particles in lithium-ion batteries

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 947-962页

作者： N.IQBAL j.CHOI s.F.sHAH C.LEE s.LEE Department of Mechanical Roboticsand Energy EngineeringDongguk University-SeoulSeoul 04620Republic of Korea

A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary NMC particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more ***,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress *** paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of NMC active particles mitigates stress levels.

关键词： lithium-ion battery(LIB) polycrystalline particle coating finite element simulation Ni-rich LiNixMnyCo_(z)O_(2)(x>0.8)(NMC)

Comparison of Adaptive simulation Observation Experiments of the Heavy Rainfall in south China and sichuan Basin

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric sciences 2024年第11期41卷 2173-2191页

作者： He L. Peng W. Zhang Y. Miao s. Chen s. Li j. shao D. Zhang X. College of Ocean and Meteorology Guangdong Ocean University Zhanjiang 524088 China Chinese Academy of Meteorology sciences Beijing 100081 China Institute of Urban Meteorology China Meteorological Administration Beijing 100089 China school of Marine sciences Nanjing University of Information Science and Technology Nanjing 210044 China Da1lian Marine Center Ministry of Nature Resources of the People’s Republic of China Dalian 116001 China

This study examines the effectiveness of adaptive observation experiments using the ensemble transformation sensitivity (ETs) method to improve precipitation forecasts during heavy rainfall events in south China and the sichuan Basin. High-resolution numerical models are employed to simulate adaptive observations. By identifying the sensitive areas of key weather system positions 42 hours before heavy rainfall events, the adaptive observations improve the prediction of j.t streams, strong winds, and shear lines, which are essential for accurate heavy rainfall forecasting. This improvement is reflected in both the precipitation structure and location accuracy within the verification region. In south China, targeted observations enhance rainfall predictions by improving water vapor transport. In the sichuan Basin, adaptive observations refine water vapor transport and adj.st vortex dynamics. This research highlights the importance of accurately predicting shear lines and j.t streams for forecasting heavy rainfall in these areas. Overall, this study found that adaptive observation enhances the precipitation forecast skills of the structure and location for heavy rainfall in south China and the sichuan Basin, emphasizing their potential utility in operational numerical weather prediction. © Institute of Atmospheric Physics/Chinese Academy of sciences, and science Press 2024.

关键词： adaptive observation data assimilation ensemble transform sensitivity rainfall

Mathematical modelling of ball and plate system with experimental and correlation function-based model validation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Control Theory and Technology 2024年第2期22卷 326-341页

作者： T.R.Dil Kumar s.j.Mij. Department of Electrical Engineering National Institute of Technology CalicutKozhikode673601KeralaIndia

The ball and plate system is an inherently nonlinear under actuated benchmark system used for validating the performance of various control schemes. A mathematical model depicting the dynamics close to that of the system is very much required for such a test bed. In this correspondence, the complete nonlinear model, a simplified nonlinear model, and a linearized model of the ball and plate system are developed. The system comprises a ball and plate mechanism and a rotary servo unit. The ball and plate mechanism is modelled using the Euler–Lagrange method, whereas the rotary servo subsystem is modelled from the first principles. The nonlinear model of the combined system is developed by including the dynamics of the servo motor with gear and rolling resistance between the ball and the plate. The simplified nonlinear model of the system is obtained with suitable assumptions. The model is linearized around the operating point using the j.cobian. The validity of the developed models is investigated through correlation function analysis. The open-loop response of the three models, viz., nonlinear, simplified nonlinear, and linearized models, is analyzed in the MATLAB/simulink platform. since the open-loop system is unstable, the experimental validation of the model is performed with a double-loop PsO (particle swarm optimization) PID control scheme.

关键词： Ball and plate system Correlation function Model validation Particle swarm optimization(PsO) PsO PID controller

Generalized Hopf Bifurcation in a Delay Model of Neutrophil Cells Model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International j.urnal of Modern Nonlinear Theory and Application 2024年第2期13卷 11-28页

作者： suqi Ma s. j. Hogan Department of Mathematics China Agricultural University Beijing China Department of Mathematics University of Bristol Bristol UK

The DDE-Biftool software is applied to solve the dynamical stability and bifurcation problem of the neutrophil cells model. Based on Hopf point finding with the stability property of the equilibrium solution loss, the continuation of the bifurcating periodical solution starting from Hopf point is exploited. The generalized Hopf point is tracked by seeking for the critical value of free parameter of the switching phenomena of the open loop, which describes the lineup of bifurcating periodical solutions from Hopf point. The normal form near the generalized Hopf point is computed by Lyapunov-schimdt reduction scheme combined with the center manifold analytical technique. The near dynamics is classified by geometrically different topological phase portraits.

关键词： Generalized Hopf Bifurcation DDE-Biftool software Norm Form