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Identification method of shoulder torque of screw-on curve of premium threaded connections for OCTG
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作者 PENG Zhiniu WANG Minghua 《Baosteel Technical Research》 CAS 2024年第3期29-32,共4页
The meaning of each part of the screw-on curve,the definition of shoulder torque,and the common characteristics of the screw-on curve are introduced.Moreover,the principle and shortcomings of the commonly used method ... The meaning of each part of the screw-on curve,the definition of shoulder torque,and the common characteristics of the screw-on curve are introduced.Moreover,the principle and shortcomings of the commonly used method of curve curvature radius are discussed.A new method of sealing surface deformation is proposed based on the requirements of shoulder torque recognition.The calculation method and principle of PW value are elucidated and the advantages of this method are summarized.The proposed method considers the difference value of tightening torque and calculates the elastic deformation of the sealing surface,accurately reflecting the state of the thread compound and the correlation between torque change and elastic deformation of the sealing surface after compression. 展开更多
关键词 screw-on shoulder torque identification method smooth torque curve
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Analysis of identification methods of key nodes in transportation network 被引量:5
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作者 Qiang Lai Hong-Hao Zhang 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第6期782-789,共8页
The identification of key nodes plays an important role in improving the robustness of the transportation network.For different types of transportation networks,the effect of the same identification method may be diff... The identification of key nodes plays an important role in improving the robustness of the transportation network.For different types of transportation networks,the effect of the same identification method may be different.It is of practical significance to study the key nodes identification methods corresponding to various types of transportation networks.Based on the knowledge of complex networks,the metro networks and the bus networks are selected as the objects,and the key nodes are identified by the node degree identification method,the neighbor node degree identification method,the weighted k-shell degree neighborhood identification method(KSD),the degree k-shell identification method(DKS),and the degree k-shell neighborhood identification method(DKSN).Take the network efficiency and the largest connected subgraph as the effective indicators.The results show that the KSD identification method that comprehensively considers the elements has the best recognition effect and has certain practical significance. 展开更多
关键词 transportation network key node identification KSD identification method network efficiency
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Numerical and experimental evaluation on methods for parameter identification of thermal response tests 被引量:3
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作者 王沣浩 冯琛琛 +1 位作者 颜亮 王新轲 《Journal of Central South University》 SCIE EI CAS 2012年第3期816-823,共8页
Several parameter identification methods of thermal response test were evaluated through numerical and experimental study.A three-dimensional finite-volume numerical model was established under the assumption that the... Several parameter identification methods of thermal response test were evaluated through numerical and experimental study.A three-dimensional finite-volume numerical model was established under the assumption that the soil thermal conductivity had been known in the simulation of thermal response test.The thermal response curve was firstly obtained through numerical calculation.Then,the accuracy of the numerical model was verified with measured data obtained through a thermal response test.Based on the numerical and experimental thermal response curves,the thermal conductivity of the soil was calculated by different parameter identification methods.The calculated results were compared with the assumed value and then the accuracy of these methods was evaluated.Furthermore,the effects of test time,variable data quality,borehole radius,initial ground temperature,and heat injection rate were analyzed.The results show that the method based on cylinder-source model has a low precision and the identified thermal conductivity decreases with an increase in borehole radius.For parameter estimation,the measuring accuracy of the initial temperature of the deep ground soil has greater effect on identified thermal conductivity. 展开更多
关键词 ground source heat pump thermal response parameter identification method numerical simulation
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Multi-source Data-driven Identification of Urban Functional Areas:A Case of Shenyang,China 被引量:3
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作者 XUE Bing XIAO Xiao +2 位作者 LI Jingzhong ZHAO Bingyu FU Bo 《Chinese Geographical Science》 SCIE CSCD 2023年第1期21-35,共15页
Urban functional area(UFA)is a core scientific issue affecting urban sustainability.The current knowledge gap is mainly reflected in the lack of multi-scale quantitative interpretation methods from the perspective of ... Urban functional area(UFA)is a core scientific issue affecting urban sustainability.The current knowledge gap is mainly reflected in the lack of multi-scale quantitative interpretation methods from the perspective of human-land interaction.In this paper,based on multi-source big data include 250 m×250 m resolution cell phone data,1.81×105 Points of Interest(POI)data and administrative boundary data,we built a UFA identification method and demonstrated empirically in Shenyang City,China.We argue that the method we built can effectively identify multi-scale multi-type UFAs based on human activity and further reveal the spatial correlation between urban facilities and human activity.The empirical study suggests that the employment functional zones in Shenyang City are more concentrated in central cities than other single functional zones.There are more mix functional areas in the central city areas,while the planned industrial new cities need to develop comprehensive functions in Shenyang.UFAs have scale effects and human-land interaction patterns.We suggest that city decision makers should apply multi-sources big data to measure urban functional service in a more refined manner from a supply-demand perspective. 展开更多
关键词 human-land relationship multi-source big data urban functional area identification method Shenyang City
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General Situation of Traditional Chinese Medicine Identification Methods
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作者 Peng LI Pingfeng LI +3 位作者 Liuyuan FAN Miao ZHANG Ruiting HE Hua ZHU 《Agricultural Biotechnology》 CAS 2018年第1期117-119,共3页
Traditional Chinese medicines are the material basis for the treatment of diseases under theoretical direction, as well as the raw materials of traditional Chinese medicine decoction pieces and Chinese patent medicine... Traditional Chinese medicines are the material basis for the treatment of diseases under theoretical direction, as well as the raw materials of traditional Chinese medicine decoction pieces and Chinese patent medicines. The quality of traditional Chinese medicine directly influences clinical efficacy. Therefore, the identification of traditional Chinese medicine is the responsibility of medicinal workers. The identification method develops from observation, tasting, smelling and listening to firing method and testing with water, and the construction of fingerprints of traditional Chinese medicines and molecular biological techniques. The development and evolution of traditional Chinese medicine identification methods was reviewed in this paper. 展开更多
关键词 Traditional Chinese medicine identification method
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Comparison of methods for identification of cold tolerance of rice
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作者 LIU Yanzhuo CHEN Zhaoming ZHANG Xu LIN Daoxuan KONG Qingui Rice Research Institute,Guangdong Academy of Agricultural Sciences,Guangzhou 510640,China 《Chinese Rice Research Newsletter》 1991年第3期3-4,共2页
Under low temperature stress,theplasmamembrane and chloroplast of plant cellsare impaired,resulting in electrolyte leakage and al-teration of chlorophyll fluorescence which can bemeasured with conductometer and fluore... Under low temperature stress,theplasmamembrane and chloroplast of plant cellsare impaired,resulting in electrolyte leakage and al-teration of chlorophyll fluorescence which can bemeasured with conductometer and fluoremeter.The cold tolerance of excised leaves of several ricevarieties were determined with these two instru-ments at seedling and heading stages to compare 展开更多
关键词 Comparison of methods for identification of cold tolerance of rice
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Identification of constitutive model parameters for nickel aluminum bronze in machining 被引量:2
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作者 付中涛 杨文玉 +2 位作者 曾思琪 郭步鹏 胡树兵 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第4期1105-1111,共7页
The material of nickel aluminum bronze (NAB) presents superior properties such as high strength, excellent wear resistance and stress corrosion resistance and is extensively used for marine propellers. In order to est... The material of nickel aluminum bronze (NAB) presents superior properties such as high strength, excellent wear resistance and stress corrosion resistance and is extensively used for marine propellers. In order to establish the constitutive relation of NAB under high strain rate condition, a new methodology was proposed to accurately identify the constitutive parameters of Johnson?Cook model in machining, combining SHPB tests, predictive cutting force model and orthogonal cutting experiment. Firstly, SHPB tests were carried out to obtain the true stress?strain curves at various temperatures and strain rates. Then, an objective function of the predictive and experimental flow stresses was set up, which put the identified parameters of SHPB tests as the initial value, and utilized the PSO algorithm to identify the constitutive parameters of NAB in machining. Finally, the identified parameters were verified to be sufficiently accurate by comparing the values of cutting forces calculated from the predictive model and FEM simulation. 展开更多
关键词 nickel aluminum bronze constitutive parameter Johnson-Cook model identification method
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Novel Model of Proton Exchange Membrane Fuel Cell with Predictive Control Using Hildreth Algorithm Based on Fractional-order Dynamic Model
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作者 Chu Kaihui Qi Zhidong +1 位作者 Qin Hao Shan Liang 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2024年第3期122-135,共14页
Considering the multivariable and fractional-order characteristics of proton exchange membrane fuel cells(PEMFCs),a fractional-order subspace identification method(FOSIM)is proposed in this paper to establish a fracti... Considering the multivariable and fractional-order characteristics of proton exchange membrane fuel cells(PEMFCs),a fractional-order subspace identification method(FOSIM)is proposed in this paper to establish a fractionalorder state space(FOSS)model,which can be expressed as a multivariable configuration with two inputs,hydrogenflow rate and stack current,and two outputs,cell voltage and power.Based on this model,a novel constrained optimal control law named the Hildreth model predictive control(H-MPC)strategy is created,which employs a Hildreth quadratic programming algorithm to adjust the output power of fuel cells through adaptively regulating hydrogen flow and stack current.dSPACE semi-physical simulation results demonstrate that,compared with proportional-integral-derivative and quadratic programming MPC(QP-MPC),the proposed H-MPC exhibits better tracking ability and strong robustness against variations of PEMFC power. 展开更多
关键词 PEMFC fractional-order subspace identification method fractional-order state space H-MPC
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Rapid identification of landslide,collapse and crack based on low-altitude remote sensing image of UAV 被引量:11
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作者 LIAN Xu-gang LI Zou-jun +4 位作者 YUAN Hong-yan LIU Ji-bo ZHANG Yan-jun LIU Xiao-yu WU Yan-ru 《Journal of Mountain Science》 SCIE CSCD 2020年第12期2915-2928,共14页
Landslides,collapses and cracks are the main types of geological hazards,which threaten the safety of human life and property at all times.In emergency surveying and mapping,it is timeconsuming and laborious to use th... Landslides,collapses and cracks are the main types of geological hazards,which threaten the safety of human life and property at all times.In emergency surveying and mapping,it is timeconsuming and laborious to use the method of field artificial investigation and recognition and using satellite image to identify ground hazards,there are some problems,such as time lag,low resolution,and difficult to select the map on demand.In this paper,a10 cm per pixel resolution photogrammetry of a geological hazard-prone area of Taohuagou,Shanxi Province,China is carried out by DJ 4 UAV.The digital orthophoto model(DOM),digital surface model(DSM) and three-dimensional point cloud model(3 DPCM) are generated in this region.The method of visual interpretation of cracks based on DOM(as main)-3 DPCM(as auxiliary) and landslide and collapse based on 3 DPCM(as main)-DOM and DSM(as auxiliary) are proposed.Based on the low altitude remote sensing image of UAV,the shape characteristics,geological characteristics and distribution of the identified hazards are analyzed.The results show that using UAV low altitude remote sensing image,the method of combination of main and auxiliary data can quickly and accurately identify landslide,collapse and crack,the accuracy of crack identification is 93%,and the accuracy of landslide and collapse identification is 100%.It mainly occurs in silty clay and mudstone geology and is greatly affected by slope foot excavation.This study can play a great role in the recognition of sudden hazards by low altitude remote sensing images of UAV. 展开更多
关键词 UAV Low altitude remote sensing image Geological hazards identification method
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Identification method of crowded passenger flow based on automatic fare collection data of Nanjing Metro 被引量:2
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作者 Lu Jia Ren Gang Xu Linghui 《Journal of Southeast University(English Edition)》 EI CAS 2019年第2期236-241,共6页
To relieve traffic congestion in urban rail transit stations,a new identification method of crowded passenger flow based on automatic fare collection data is proposed.First,passenger travel characteristics are analyze... To relieve traffic congestion in urban rail transit stations,a new identification method of crowded passenger flow based on automatic fare collection data is proposed.First,passenger travel characteristics are analyzed by observing the temporal distribution of inflow passengers each hour and the spatial distribution concerning cross-section passenger flow.Secondly,the identification method of crowded passenger flow is proposed to calculate the threshold via the probability density function fitted by Matlab and classify the early-warning situation based on the threshold obtained.Finally,a case study of Xinjiekou station is conducted to prove the validity and practicability of the proposed method.Compared to the traditional methods,the proposed comprehensive method can remove defects such as efficiency and delay.Furthermore,the proposed method is suitable for other rail transit companies equipped with automatic fare collection systems. 展开更多
关键词 travel characteristic identification method crowded passenger flow automatic fare collection
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Objective identification research on cold vortex and mid-summer rainy periods in Northeast China 被引量:1
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作者 龚志强 封泰晨 房一禾 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第4期571-580,共10页
Considering the differences between the Northeast China Cold Vortex (CV) and the Mid-Summer (MS) rainy period and their corresponding atmospheric circulations are comprehensively analyzed, and the objective identi... Considering the differences between the Northeast China Cold Vortex (CV) and the Mid-Summer (MS) rainy period and their corresponding atmospheric circulations are comprehensively analyzed, and the objective identification methods of defining the annual beginning and ending dates of Northeast China CV and MS rainy periods are developed respectively. The annual beginning date of the CV (MS) rainy period is as follows. In a period from April to August, if daily regional mean precipitation ryi is larger than yearly regional mean precipitation R (or 2R) on a certain day, the station precipitation rs is larger than the station yearly mean precipitation (r/ (or 2(r)) in at least 50% of stations in Northeast China, and this condition is satisfied in the following 2 (7) days, then this date is defined as the beginning date of the CV (MS) rainy period. While the definition of the ending date of the MS rainy period shows the opposite process to its beginning date. With this objective identification method, the multi-year average (1981-2010) beginning date of the CV rainy period is May 3, the beginning date of the MS rainy period is June 27, the ending day of the CV rainy period is defined as the day before the beginning date of the MS rainy period, and the ending date of the MS rainy period is August 29. Meanwhile, corresponding anomaly analysis at a 500-hPa geopotential height, 850-hPa wind, Omega and relative humidity fields all show that the definitions of the average beginning and ending dates of the CV and MS rainy periods have a certain circulation meaning. Furthermore, the daily evolution of the CV index, meridional and zonal wind index, etc. all show that these objectively defined beginning and ending dates of the CV and MS rainy periods have climate significance. 展开更多
关键词 Northeast China cold vortex rainy period mid-summer rain period objective identification method
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Physical Parameter Identification Method Based on Modal Analysis for Two-axis On-road Vehicles:Theory and Simulation 被引量:3
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作者 ZHENG Minyi ZHANG Bangji +1 位作者 ZHANG Jie ZHANG Nong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第4期756-764,共9页
Physical parameters are very important for vehicle dynamic modeling and analysis.However,most of physical parameter identification methods are assuming some physical parameters of vehicle are known,and the other unkno... Physical parameters are very important for vehicle dynamic modeling and analysis.However,most of physical parameter identification methods are assuming some physical parameters of vehicle are known,and the other unknown parameters can be identified.In order to identify physical parameters of vehicle in the case that all physical parameters are unknown,a methodology based on the State Variable Method(SVM) for physical parameter identification of two-axis on-road vehicle is presented.The modal parameters of the vehicle are identified by the SVM,furthermore,the physical parameters of the vehicle are estimated by least squares method.In numerical simulations,physical parameters of Ford Granada are chosen as parameters of vehicle model,and half-sine bump function is chosen to simulate tire stimulated by impulse excitation.The first numerical simulation shows that the present method can identify all of the physical parameters and the largest absolute value of percentage error of the identified physical parameter is 0.205%;and the effect of the errors of additional mass,structural parameter and measurement noise are discussed in the following simulations,the results shows that when signal contains 30 d B noise,the largest absolute value of percentage error of the identification is 3.78%.These simulations verify that the presented method is effective and accurate for physical parameter identification of two-axis on-road vehicles.The proposed methodology can identify all physical parameters of 7-DOF vehicle model by using free-decay responses of vehicle without need to assume some physical parameters are known. 展开更多
关键词 Parameter identification free-decay response state variable method modal parameter physical parameter
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RESEARCH ON AUTOMATIC FOG IDENTIFICATION TECHNOLOGY BY METEOROLOGICAL SATELLITE REMOTE SENSING 被引量:1
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作者 周红妹 葛伟强 +2 位作者 柏桦 刘冬韡 杨引明 《Journal of Tropical Meteorology》 SCIE 2009年第1期28-37,共10页
There is an urgent need for the development of a method that can undertake rapid, effective, and accurate monitoring and identification of fog by satellite remote sensing, since heavy fog can cause enormous disasters ... There is an urgent need for the development of a method that can undertake rapid, effective, and accurate monitoring and identification of fog by satellite remote sensing, since heavy fog can cause enormous disasters to China’s national economy and people's lives and property in the urban and coastal areas. In this paper, the correlative relationship between the reflectivity of land surface and clouds in different time phases is found, based on the analysis of the radiative and satellite-based spectral characteristics of fog. Through calculation and analyses of the relative variability of the reflectivity in the images, the threshold to identify quasi-fog areas is generated automatically. Furthermore, using the technique of quick image run-length encoding, and in combination with such practical methods as analyzing texture and shape fractures, smoothness, and template characteristics, the automatic identification of fog and fog-cloud separation using meteorological satellite remote sensing images are studied, with good results in application. 展开更多
关键词 meteorological satellites remote sensing fog dynamic monitoring rapid and automatic identification methods
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Non-probabilistic information fusion technique for structural damage identification based on measured dynamic data with uncertainty 被引量:2
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作者 Xiao-Jun Wang Chen Yang Zhi-Ping Qiu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2013年第2期202-210,共9页
Based on measured natural frequencies and acceleration responses,a non-probabilistic information fusion technique is proposed for the structural damage detection by adopting the set-membership identification(SMI) an... Based on measured natural frequencies and acceleration responses,a non-probabilistic information fusion technique is proposed for the structural damage detection by adopting the set-membership identification(SMI) and twostep model updating procedure.Due to the insufficiency and uncertainty of information obtained from measurements,the uncertain problem of damage identification is addressed with interval variables in this paper.Based on the first-order Taylor series expansion,the interval bounds of the elemental stiffness parameters in undamaged and damaged models are estimated,respectively.The possibility of damage existence(PoDE) in elements is proposed as the quantitative measure of structural damage probability,which is more reasonable in the condition of insufficient measurement data.In comparison with the identification method based on a single kind of information,the SMI method will improve the accuracy in damage identification,which reflects the information fusion concept based on the non-probabilistic set.A numerical example is performed to demonstrate the feasibility and effectiveness of the proposed technique. 展开更多
关键词 Damage identification·Information fusion technique·Set-membership identification(SMI)·Uncertainty·Interval analysis method
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IMPROVED COVARIANCE DRIVEN BLIND SUBSPACE IDENTIFICATION METHOD
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作者 ZHANG Zhiyi FAN Jiangling HUA Hongxing 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2006年第4期548-553,共6页
An improved covariance driven subspace identification method is presented to identify the weakly excited modes. In this method, the traditional Hankel matrix is replaced by a reformed one to enhance the identifiabilit... An improved covariance driven subspace identification method is presented to identify the weakly excited modes. In this method, the traditional Hankel matrix is replaced by a reformed one to enhance the identifiability of weak characteristics. The robustness of eigenparameter estimation to noise contamination is reinforced by the improved Hankel matrix, in combination with component energy index (CEI) which indicates the vibration intensity of signal components, an alternative stabilization diagram is adopted to effectively separate spurious and physical modes. Simulation of a vibration system of multiple-degree-of-freedom and experiment of a frame structure subject to wind excitation are presented to demonstrate the improvement of the proposed blind method. The performance of this blind method is assessed in terms of its capability in extracting the weak modes as well as the accuracy of estimated parameters. The results have shown that the proposed blind method gives a better estimation of the weak modes from response signals of small signal to noise ratio (SNR)and gives a reliable separation of spurious and physical estimates. 展开更多
关键词 Subspace identification method Weak modes Hankel matrix Component energy index (CEI) Stabilization diagram
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RECONSTRUCTION OF PART OF AN ACTUAL BLAST-WAVE FLOW FIELD TO AGREE WITH EXPERIMENTAL DATA BY USING NUMERICAL METHOD WITH HIGH IDENTIFICATION
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作者 吴清松 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1989年第10期925-932,共8页
In this paper, on the basis of experimental data of two kinds of chemical explosions, the piston-pushing model of spherical blast-waves and the second-order Godunov-type scheme of finite difference methods with high i... In this paper, on the basis of experimental data of two kinds of chemical explosions, the piston-pushing model of spherical blast-waves and the second-order Godunov-type scheme of finite difference methods with high identification to discontinuity are used to the numerical reconstruction of part of an actual hemispherical blast-wave flow field by properly adjusting the moving bounary conditions of a piston. This method is simple and reliable. It is suitable to the evaluation of effects of the blast-wave flow field away from the explosion center. 展开更多
关键词 RECONSTRUCTION OF PART OF AN ACTUAL BLAST-WAVE FLOW FIELD TO AGREE WITH EXPERIMENTAL DATA BY USING NUMERICAL METHOD WITH HIGH identificATION ANFO TNT
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A Review of Identity Methods of Internet of Things (IOT)
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作者 Sana Abdelaziz Bkheet Johnson I. Agbinya 《Advances in Internet of Things》 2021年第4期153-174,共22页
The Internet of Things (IOT) is a recent technology originating from the field of sensor networks. It has received significant attention because it is involved in most aspects of our daily lives. The IOT vision makes ... The Internet of Things (IOT) is a recent technology originating from the field of sensor networks. It has received significant attention because it is involved in most aspects of our daily lives. The IOT vision makes objects of various kinds become part of the Internet by assigning each object a unique identifier, enabling objects to communicate with each other in the same or different environments. IOT can collect, process, and exchange data via a data communication network. There are many methods for identifying objects;some have existed since the beginning of IOT innovation, such as Radio Frequency Identification (RFID), Barcode/2D code, IP address, Electronic Product Codes (EPC), etc. Continuous development in IOT domain and the large number of objects connected to the Internet daily require an improved identification method to cope with the rapid development in this field. Many modern methods have been proposed recently, based on various technologies such as computer vision, fingerprinting, and machine learning. This paper introduces an overview of IOT and discusses its fundamental elements;it mainly focuses on identification of IOT which is considered the main part that the IOT systems rely on. The paper discusses the existing identification methods for IOT. Moreover, it provides a review of the modern identification methods proposed in recent literature. 展开更多
关键词 IOT IOT Elements Wireless Sensor Network (WSN) identification methods
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Vortex analysis of water flow through gates by different vortex identification methods 被引量:1
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作者 Chun-ying Shen Rui-guo Yang +1 位作者 Shan Qing Shi-hua He 《Journal of Hydrodynamics》 SCIE EI CSCD 2023年第1期112-124,共13页
The pre-gate suction vortex,gate-bottom-edge transverse vortex,gate-slot vertical vortex,and downstream-of-gate return vortex are important factors affecting the flow instability of flat gates,which may lead to fatigu... The pre-gate suction vortex,gate-bottom-edge transverse vortex,gate-slot vertical vortex,and downstream-of-gate return vortex are important factors affecting the flow instability of flat gates,which may lead to fatigue failure in severe cases.This study used the volume of fluid(VOF)model and large eddy simulation(LES)method to accurately capture the transient turbulence characteristics of flow under different water flow conditions and reveal the flow field and vortex structure.The Q—criterion,Omega(Ω)method,and latest third-generation Liutex vortex identification method were used to analyze and compare the pre-gate suction vortex,gate-slot vertical vortex,and downstream-of-gate return vortex,focusing on the ability of each vortex identification method to capture the flow field information and vortex characteristics.The results reveal that theΩmethod and Liutex method are less dependent on the threshold value,and the Liutex method captures a wide range of pre-gate vortices.Different flow conditions cause changes in the vortex structure of over-gate flow.When the relative opening of the gate is smaller,the intensity of the vortices in the flow field around the gate is greater,the return vortices downstream of the gate are more disordered,and the vortex changes are more violent,which in turn affects the efficient and stable operation of the gate. 展开更多
关键词 Vortex features vortex identification methods Liutex Ωmethod Q-criterion large eddy simulation(LES)
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Vortex identification based on the Liutex method and its effect on fish passage upstream
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作者 Chun-ying Shen Rui-guo Yang +2 位作者 Xiao-tao Shi Ming-ming Wang Shi-hua He 《Journal of Hydrodynamics》 SCIE EI CSCD 2024年第1期130-141,共12页
Fishway research is important for mitigating the fragmentation of river habitats caused by hydraulic projects.The vertical slit fishway is a broadly used fishway type because of its high efficiency and adaptability to... Fishway research is important for mitigating the fragmentation of river habitats caused by hydraulic projects.The vertical slit fishway is a broadly used fishway type because of its high efficiency and adaptability to water levels.However,the resulting vortex current disrupts the fish passage hence directly affecting fish migration.This study aims to accurately capture the vortex structure in the fishway and analyze the effect of vortex elements(vortex structure,vortex intensity,etc.)on fish.We conducted an analysis of the 3-D current flow field in the fishway through the utilization of an experimental model and the large eddy simulation(LES)method.Moreover,we captured the vortex information in the fishway at different flow rates using the Liutex vortex identification method and investigated the effect of the vortex on fish migration.The results revealed that the structures inside the fishway pool occupy most of the room,however,the areas with higher vortex strength were primarily located in the vortex near the vertical seam and the mainstream,the vortex strength inside the fishway gradually increases with increasing flow,suppressing fish migration.Fish experienced significantly increased resistance when encountering strong vortices.This suggests that the vortex may act as a physical barrier to fish migration.These findings highlight the potential negative effects of vortex on fish movement and reiterate the importance of understanding vortex dynamics for aquatic environmental management.As an effective tool for identifying vortices in fluid flow,the Liutex method demonstrates features of vortex within the fishway,thereby providing important insights into the interaction between fluid dynamics and aquatic organisms. 展开更多
关键词 Vertical slit fishway vortex identification method Liutex large eddy simulation(LES) fish experiment computational fluid dynamics
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An Overview of Calibration Technology of Industrial Robots 被引量:27
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作者 Zhibin Li Shuai Li Xin Luo 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2021年第1期23-36,共14页
With the continuous improvement of automation,industrial robots have become an indispensable part of automated production lines.They widely used in a number of industrial production activities,such as spraying,welding... With the continuous improvement of automation,industrial robots have become an indispensable part of automated production lines.They widely used in a number of industrial production activities,such as spraying,welding,handling,etc.,and have a great role in these sectors.Recently,the robotic technology is developing towards high precision,high intelligence.Robot calibration technology has a great significance to improve the accuracy of robot.However,it has much work to be done in the identification of robot parameters.The parameter identification work of existing serial and parallel robots is introduced.On the one hand,it summarizes the methods for parameter calibration and discusses their advantages and disadvantages.On the other hand,the application of parameter identification is introduced.This overview has a great reference value for robot manufacturers to choose proper identification method,points further research areas for researchers.Finally,this paper analyzes the existing problems in robot calibration,which may be worth researching in the future. 展开更多
关键词 Absolute pose accuracy identification method industrial robots parameter identification robot calibration technology robot parameters
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