检索结果-南通市图书馆

Predicting Traffic Flow Using Dynamic Spatial-Temporal Graph Convolution Networks

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第3期78卷 4343-4361页

作者： Yunchang Liu Fei Wan Chengwu Liang School of Computer and Data Science Henan University of Urban ConstructionPingdingshan467036China School of Electrical and Control engineering Henan University of Urban ConstructionPingdingshan467036China

Traffic flow prediction plays a key role in the construction of intelligent transportation ***,due to its complex spatio-temporal dependence and its uncertainty,the research becomes very *** of the existing studies are based on graph neural networks that model traffic flow graphs and try to use fixed graph structure to deal with the relationship between ***,due to the time-varying spatial correlation of the traffic network,there is no fixed node relationship,and these methods cannot effectively integrate the temporal and spatial *** paper proposes a novel temporal-spatial dynamic graph convolutional network(TSADGCN).The dynamic time warping algorithm(DTW)is introduced to calculate the similarity of traffic flow sequence among network nodes in the time dimension,and the spatiotemporal graph of traffic flow is constructed to capture the spatiotemporal characteristics and dependencies of traffic *** combining graph attention network and time attention network,a spatiotemporal convolution block is constructed to capture spatiotemporal characteristics of traffic *** on open data sets PEMSD4 and PEMSD8 show that TSADGCN has higher prediction accuracy than well-known traffic flow prediction algorithms.

关键词： Intelligent transportation graph convolutional network traffic flow DTW algorithm attention mechanism

Anti-windup-based Dynamic Controller Synthesis for Lipschitz Systems under Actuator Saturation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2015年第4期2卷 358-365页

作者： Naizhou Wang Hailong Pei Yong Tang Key laboratory of Autonomous Systems and Networked Control Ministry of EducationSouth China University of Technology Key laboratory of Surface functional structure Manufacturing of Guangdong Higher Education Institutes School of Mechanical and Automotive EngineeringSouth China University of Technology

This paper presents a new method for simultaneous synthesis of dynamic controller and static anti-windup compensator for saturated Lipschitz systems. Thanks to the reformulated Lipschitz property, the Lipschitz systems can be transformed into LPV (linear parameter-varying) systems whose system matrices are affine in a parameter matrix. Based on the modified sector condition dealing with saturation nonlinearity, the design of a nonlinear anti-windup-based controller leads to the solvability of a set of bilinear matrix inequalities (BMI) on the vertices of a bounded convex set which can be solved by the so-called iterative linear matrix inequality (ILMI) algorithm. A numerical example is presented to illustrate the effectiveness of the proposed method. © 2014 Chinese Association of Automation.

关键词： Controllers Iterative methods Linear algebra Matrix algebra Numerical methods Set theory Synthesis (chemical)

Crystal-Plasticity-Based Dynamic Constitutive Model of AZ31B Magnesium Alloy at Elevated Temperature and with Explicit Plastic-Strain-Rate Control

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2020年第1期33卷 31-50页

作者： Qijun Xie Zhiwu Zhu Guozheng Kang Key laboratory of Mountain Hazards and Earth Surface Processes Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041China State Key laboratory of Traction Power Southwest Jiaotong UniversityChengdu 610031China Applied Mechanics and structure Safety Key laboratory of Sichuan Province School of Mechanics and EngineeringSouthwest Jiaotong UniversityChengdu 610031China

In this study,a series of experiments were carried out on the AZ31B magnesium alloy,including both a macro-experiment(mechanical experiment)and a micro-experiment(dislocation observation).Next,based on the consideration of the deformation mechanism of magnesium alloys(dislocation slip and twinning),a dynamic constitutive model of the magnesium alloy was *** the developed model,the strain-rate-sensitivity control and the effect of temperature on the dynamic mechanical performance of the alloy were also *** model parameters were determined by fitting the macroscopic experimental ***,the evolution of the micro-deformation mechanism was calculated by the developed model,and the trend of macro-mechanical behavior was also discussed.

关键词： Magnesium alloy Constitutive model Microscopic mechanism Dynamic test Crystal plasticity

Inactivation efficiency of slightly acidic electrolyzed water against microbes on facility surfaces in a disinfection channel

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 Journal of Agricultural and Biological engineering 2017年第6期10卷 23-30页

作者： Zang Yitian Li Baoming Shi Zhengxiang Sheng Xiaowei Wu Hongxiang Shu Dengqun College of Animal Science and Technology Jiangxi Agricultural UniversityNanchang 330045China Key laboratory of structure and Environment in Agricultural engineering Ministry of AgricultureChina Agricultural UniversityBeijing 100083China

Slightly acidic electrolyzed water(SAEW,pH 6.0-6.5)is an ideal and environmentally-friendly disinfectant,which was used to prevent and control bacterial infections on *** work aims to investigate the inactivation effectiveness of SAEW in inactivating microbes in a disinfection *** bactericidal efficiency of SAEW on equipment surfaces was compared to two commercial disinfectants,Kuei A bromide solution(KAS,5:1000 v/v)and Glutaraldehyde solution(GS,5:1000 v/v).The disinfection effectiveness of SAEW in inactivating Salmonella enteritidis(***)on equipment surfaces in the disinfection channel was evaluated,and a model was developed using multiple linear regression *** indicated that SAEW was significantly(p0.05).In addition,available chlorine concentration(ACC)was an important factor than other factors,and the inactivation efficiency of Salmonella enteritidis sprayed by SAEW treatment was different between iron materials,kits and clothing surfaces(iron>kit>clothing).

关键词： slightly acidic electrolyzed water disinfection channel S.enteritidis disinfection bacterial infection prevention and control livestock farm

Theoretical prediction for effective properties and progressive failure of textile composites:a generalized multi-scale approach

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2021年第8期37卷 1222-1244,I0001页

作者： Haoyuan Dang Peng Liu Yinxiao Zhang Zhenqiang Zhao Liyong Tong Chao Zhang Yulong Li Department of Aeronautical structure engineering Northwestern Polytechnical UniversityXi’an 710072 China 2 Shaanxi Key laboratory of Impact Dynamics and Its engineering Applications Xi’an 710072 China 3 Joint International Research laboratory of Impact Dynamics and Its engineering Applications Xi’an 710072 China 4 School of Science Harbin Institute of TechnologyShenzhen 518055 China 5 School of Aerospace Mechanical and Mechatronic EngineeringThe University of SydneySydneyNSW 2006Australia

A generalized analytical model is developed to predict progressive failure behavior of several types of textile composites,including plain weave composites,twill weave composites,two-dimensional tri-axially braided composites and warpreinforced 2.5-dimensional braided *** this model,the unit cell(UC)of composite is firstly identified and reconstructed into a refined lamina structure with multiple equivalent lamina elements(ELEs)based on apt geometrical approximation and ***,two-way coupled stress-strain responses within the UC(macro-scale)and ELE(meso-scale)are established through a universal series-parallel model(SPM).Finally,a progressive damage model,which consists of damage initiation criteria and a stiffness evolution strategy,is employed to predict damage behavior of the *** analytical results including mechanical properties and progressive failure process are validated against the existing numerical and experimental ones in *** validated analytical model is then used to study the effects of global fiber volume fraction,braided angle,shear failure coefficient and selected failure criteria on stiffness,strength and failure *** present results demonstrate the efficiency and generic capability of the present analytical model for predicting the mechanical responses of a range of textile composites.

关键词： Textile composites Analytical model Series-parallel model Damage mechanics Strength

Preparation of multicolor carbon dots with thermally turn-on fluorescence for multidimensional information encryption

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第1期35卷 343-347页

作者： Chan Wang Jianfeng Huang Yimin He Guoxia Ran Qijun Song Key laboratory of Synthetic and Biological Colloids Ministry of EducationInternational Joint Research Center for Photoresponsive Molecules and MaterialsSchool of Chemical&Material EngineeringJiangnan UniversityWuxi 214122China Department of Radiation Oncology Affiliated Hospital of Jiangnan UniversityWuxi 214122China

Carbon dots(CDs)with superior fluorescence properties have attracted a growing number of research interests in ***,the preparation of CDs with thermally turn-on fluorescence and full-color-emitting in visible spectrum is still a big challenge due to the complicated reaction mechanism in the formation of ***,a simple precursor-oriented strategy for the preparation of multicolor CDs with heat-stimuli turn-on fluorescence is *** experimental characterizations and theoretical calculations revealed that the emission wavelength of CDs can be readily tuned from 460 nm to 654 nm with selected precursors,which was ascribed to the extent of conjugated sp2-domains(core states)and the amount of oxygen-and nitrogen-containing groups bound to sp2-domains(surface states).After simply mixing two or three kinds of CDs,a full-color range of fluorescence emission was realized,and the CDs-based fluorescence inks were successfully ***,all the printed patterns from the inkjet exhibited a thermal-induced enhancement in *** this basis,combining CDs with heating-induced“turn-off”fluorescence materials can lead to multidimensional and multistage *** results demonstrate that the thermochromic and photochromic CDs with much more enhanced security exhibit promising application in data storage and encryption.

关键词： Carbon dots Precursor-oriented structure Full-color fluorescence Turn-on thermosensitivity Advanced anti-counterfeiting

Neural network and support vector machine models for the prediction of the liquefaction-induced uplift displacement of tunnels

在线全文

学校读者我要写书评

暂无评论

Underground Space 2021年第2期6卷 126-133页

作者： Gang Zheng Wenbin Zhang Wengang Zhang Haizuo Zhou Pengbo Yang School of Civil engineering Tianjin UniversityTianjin 300072China Key laboratory of Coast Civil structure Safety Tianjin UniversityMinistry of EducationTianjin 300072China State Key laboratory of Hydraulic engineering Simulation and Safety Tianjin UniversityTianjin 300072China National Joint engineering Research Center of Geohazards Prevention in Reservoir Area Environment School of Civil EngineeringChongqing UniversityChongqing 400045China

Tunnels buried in liquefiable deposits are vulnerable to liquefaction-induced uplift damage during *** paper presents support vector machine(SVM)and artificial neural network(ANN)models to predict the liquefaction-induced uplift displacement of tunnels based on artificial databases generated by the finite difference *** performance of the SVM and ANN models was assessed using statistical parameters,including the coefficient of determination R^(2),the mean absolute error,and the root mean squared *** for the above-mentioned approaches are compared and discussed.A relative importance analysis was adopted to quantify the sensitivity of each input *** precision of the presented models is demonstrated using centrifuge test results from previous studies.

关键词： Artificial neural network Support vector machine Liquefaction Uplift displacement

Flexural Capacity Formula of Diaphragm-Through Joints of Concrete-Filled Square Steel Tubular Columns

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transactions of Tianjin University 2017年第3期23卷 258-266页

作者： Bin Rong Rui Liu Zhenyu Li Changxi Feng Guangchao You Fafitis Apostolos School of Civil engineering Tianjin UniversityTianjin 300072China Key laboratory of Coast Civil structure Safety Ministry of EducationTianjin 300072China Department of Civil and Environmental engineering Arizona State UniversityTempe 85287USA

Finite element analysis and parametric studies were performed to investigate the flexural capacity of the panel zone of diaphragm-through joints between concrete-filled square steel tubular columns and H-shaped steel beams. Through the comparisons of failure modes, load–displacement curves, and bearing capacity, it was found that the flexural capacity of the panel zone of diaphragm-through joints was determined by the tensile action and influence of the web of H-shaped steel beams, and the axial load should be taken into account. The steel tube and the diaphragm were the major parts of the joint that resisted the bending moment. The contribution of in-filled concrete had little influence on the flexural capacity of the panel zone of the joint and could be neglected. According to the results of these numerical studies, a formula that considered the influence of the web of H-shaped steel beams and the axial load was developed based on the yield lines in the diaphragm and the steel tube. The results of the proposed formula were in good agreement with the numerical data of this investigation. © 2017, Tianjin University and Springer-Verlag Berlin Heidelberg.

关键词： Axial loads Concretes Diaphragms Steel beams and girders Tubular steel structures Web crawler

Improvement of mechanical properties and investigation of strengthening mechanisms on the Ti_(3)AlC_(2) ceramic with nanosized WC addition

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2024年第6期13卷 861-876页

作者： Yi Zhong Ying Liu Qinkai Jiang Na Jin Zifeng Lin Jinwen Ye School of Materials Science&engineering Sichuan UniversityChengdu 610065China Yibin R&D Park Yibin Industrial Technology Research InstituteSichuan UniversityYibin 644005China

Ti_(3)AlC_(2) (TAC) has great potential for use as an ablation material in aerospace applications due to its great oxidation/ablation resistance, but its high-temperature strength and thermal shock resistance still have much room for simultaneous improvement under fast temperature variation conditions. Herein, we used Ti_(3)AlC_(2) and WC powders as raw materials and successfully fabricated textured (Ti,W)_(3)AlC_(2) ceramic with small amounts of TiC and Al_(2)O_(3), and room temperature mechanical properties such as flexural strength (1146±46.9 MPa), fracture toughness (11.78±0.44 MPa·m^(1/2)), and hardness (5.81±0.11 GPa) at 5 wt% WC addition were achieved. The high-temperature strength of the ceramic was significantly improved, and better thermal shock resistance from 298 to 1173 K was simultaneously acquired together with the regulation of the elastic modulus, thermal conductivity, and thermal expansion coefficient, providing (Ti,W)_(3)AlC_(2) with more possibilities for fast-temperature variation applications. Strengthening and toughening mechanisms were proposed. Scanning transmission electron microscopy high-angle annular dark-field imaging (STEM-HADDF) showed that W randomly replaced the Ti1 and Ti2 sites of Ti_(3)AlC_(2), providing a good reference for establishing crystal models, and further density functional theory (DFT) calculations based on these models indicated a higher fracture energy of (Ti,W)_(3)AlC_(2) along different crystal planes, providing superior resistance to transgranular fracture;a lower mismatch degree of (Ti,W)_(3)AlC_(2)/Al_(2)O_(3) resulted in stronger interface bonding, resulting in greater resistance to intergranular fracture as well as more balanced stress distributions at different interfaces.

关键词： mechanical properties solid solution MAX phase transmission electron microscopy(TEM) ceramic atomic structure