Existing elevator fault diagnosis algorithms have limited engineering applicability due to variations in working conditions and differences in equipment structures.To address this limitation,this study proposes an uns...Existing elevator fault diagnosis algorithms have limited engineering applicability due to variations in working conditions and differences in equipment structures.To address this limitation,this study proposes an unsupervised subdomain adaptation method based on a time-frequency feature attention mechanism,LMMD-based subdomain alignment,and contrastive local alignment.This enables the application of the diagnosis model across different working conditions and equipment types.First,a novel time-frequency feature attention mechanism assigns weights to vibration signals of varying dimensions.Second,the time series is transformed to obtain a three-channel time-frequency diagram.This diagram is input into the proposed dimension-segmentation cross-channel multihead self-attention framework to extract high-dimensional frequencydomain fault features.These features are concatenated with the time-domain features to obtain a global feature representation.Then,the extracted high-dimensional features are sent to the classification module to obtain the predicted labels for the source and target domains.Finally,after confidence filtering,the true labels from the source domain and the prediction labels from the target domain are fed into a dynamically weighted multilevel feature alignment module to promote proximity between similar fault features across domains while enhancing separation among different fault types.The validity and superiority of the proposed method were demonstrated through simulation experiments conducted on two types of manned escalator systems under multiple working conditions.For the most challenging transfer task,the proposed method achieved higher accuracy on the target domain test set than DANN,ADDA,C-CLCN,TFA-CCN,and TFA-LCN by 26.87%,24.72%,11.44%,28.94%,and 16.85%,respectively.展开更多
With the acceleration of urbanization and the increasing number of high-rise buildings,elevators,as key equipment for vertical transportation,have attracted significant attention regarding the safety,reliability,and e...With the acceleration of urbanization and the increasing number of high-rise buildings,elevators,as key equipment for vertical transportation,have attracted significant attention regarding the safety,reliability,and efficiency of their operation.This design develops a four-floor elevator control system based on S7-200PLC.It realizes the following functions:the second and third floors support both upward and downward request functions(with corresponding indicator lights turning on),the first floor only supports the upward request function,and the fourth floor only supports the downward request function.Meanwhile,the elevator automatically opens its door after arriving at each floor and closes the door automatically 6 seconds later.The design aims to achieve precise control and efficient operation of the elevator.展开更多
With the continuous development and wide application of modern technology,more enterprises and institutions in our country have begun to strengthen the research and manufacturing of intelligent elevators,aiming to bui...With the continuous development and wide application of modern technology,more enterprises and institutions in our country have begun to strengthen the research and manufacturing of intelligent elevators,aiming to build a new mode of modern manufacturing with the concept of green development as the core.Therefore,this paper takes green manufacturing as the background,analyzes the design significance of intelligent elevator lightweight,expounds its design ideas,and in the end introduces its specific design practice path.展开更多
This paper proposed a new libration decoupling analytical speed function(LD-ASF)in lieu of the classic analytical speed function to control the climber's speed along a partial space elevator to improve libration s...This paper proposed a new libration decoupling analytical speed function(LD-ASF)in lieu of the classic analytical speed function to control the climber's speed along a partial space elevator to improve libration stability in cargo transportation.The LD-ASF is further optimized for payload transportation efficiency by a novel coordinate game theory to balance competing control objectives among payload transport speed,stable end body's libration,and overall control input via model predictive control.The transfer period is divided into several sections to reduce computational burden.The validity and efficacy of the proposed LD-ASF and coordinate game-based model predictive control are demonstrated by computer simulation.Numerical results reveal that the optimized LD-ASF results in higher transportation speed,stable end body's libration,lower thrust fuel consumption,and more flexible optimization space than the classic analytical speed function.展开更多
The infrared channels of the FY-4B advanced geosynchronous radiation imagers(AGRI) play a crucial role in temperature and humidity analyses for mesoscale numerical weather prediction, particularly in enhancing the ini...The infrared channels of the FY-4B advanced geosynchronous radiation imagers(AGRI) play a crucial role in temperature and humidity analyses for mesoscale numerical weather prediction, particularly in enhancing the initial field quality and the forecasting accuracy of the model. This study assimilated FY-4B AGRI data into the CMA-MESO model and analyzed the bias characteristics and correction methods. Analysis of the AGRI data revealed a clear diurnal variation in the bias, which was positively correlated with the solar elevation angle. However, the diurnal variation in the bias lagged behind the solar elevation angle, likely owing to temperature changes and delayed instrument responses resulting from solar radiation. To address this issue, we propose a correction method that utilizes the solar elevation angle after an optimal time shift. Using the time-shifted solar elevation angle as a predictor effectively reduces the diurnal variation in bias and significantly improves the correction effect. This approach provides theoretical support for the assimilation of FY-4B AGRI data into mesoscale numerical weather predictions, thereby enhancing the reliability of the assimilation results.展开更多
Elevation patterns and assembly processes of soil microbial community structures are essential for understanding biogeo-chemical processes in mountain systems.Differences in soil properties caused by elevation gradien...Elevation patterns and assembly processes of soil microbial community structures are essential for understanding biogeo-chemical processes in mountain systems.Differences in soil properties caused by elevation gradients can regulate the spatial distribu-tion and network complexity of the community structure.To explore the variations in soil microbial community structures and their as-sembly mechanisms across different elevations of the Changbai Mountains,as well as their responses to environmental factors,we col-lected microbial samples along an elevational gradient(seven elevations containing four vegetation zones)on the western slope of the Changbai Mountains using the method of metagenomic sequencing.The results showed a significant difference(P<0.05)for the Chao1 index across different elevations,but no significant difference was observed for the Shannon and Simpson indices.With increasing elev-ation,the number of nodes and links in the microbial network gradually decreased.Acidobacteria were highly connected to many nodes.The microbial communities indicated a significant distance-decay relationship(P<0.001)and were affected more by stochastic pro-cesses along the elevation gradient.The results of the Structural Equation Model(SEM)showed that elevation had direct significant ef-fect on carbon(C,P<0.01),nitrogen(N,P<0.01),and phosphorus(P,P<0.05)and weak negative effect on their ecological stoi-chiometry.Elevation was one of the major variables contributing to microbial network topology.The contribution of C and N to micro-bial network complexity was higher than that of P.Our study provides valuable insights into the responses of soil microbial communit-ies to elevation variations.展开更多
Increasing atmospheric CO_(2)concentrations from~280 ppm in the pre-industrial era to over 420 ppm today, and projected to exceed 550 ppm by 2050(IPCC, 2023), are transforming the biochemical context of plant metaboli...Increasing atmospheric CO_(2)concentrations from~280 ppm in the pre-industrial era to over 420 ppm today, and projected to exceed 550 ppm by 2050(IPCC, 2023), are transforming the biochemical context of plant metabolism,causing restructuring of carbon and nitrogen balance in crops. Though elevated CO_(2)(eCO_(2)) increases photosynthetic efficacy and biomass accumulation in many C3crops, it also disrupts carbon-nitrogen balance, leading to nitrogen dilution in leaves and grains, eventually compromising food quality(Myers et al., 2014;Rezaei et al., 2023). Rice is a staple food that feeds nearly half of the world's population;it requires sustained yield gains, considering an estimated 35%-56%increase in demand by 2050, as the global population approaches 10 billion(Van Dijk et al., 2021), while reducing dependency on nitrogen fertilizers, whose production and overuse contribute significantly to greenhouse gas emission(Qian et al., 2023). Yet, most breeding programs remain regulated to present-day atmospheric conditions, overlooking the physiological and molecular adaptations required for future CO_(2)climates.展开更多
A new instrument for checking the quality of elevator guide rails is introduced.With this instrument,the general geometric errors such as straightness,flatness,squareness,twist,thickness and height can be measured aut...A new instrument for checking the quality of elevator guide rails is introduced.With this instrument,the general geometric errors such as straightness,flatness,squareness,twist,thickness and height can be measured automatically,simultaneously in a short time with high accuracy.It is very useful for elevator guide rail factories to improve their work efficiency and the quality of their products.展开更多
The aim of the study is to simulate actual operation of an elevator. First, it designed elevator scheduling algorithm for control ing operation of the elevator;second, it simulated elevator operation by the use of obj...The aim of the study is to simulate actual operation of an elevator. First, it designed elevator scheduling algorithm for control ing operation of the elevator;second, it simulated elevator operation by the use of object-oriented programming language, in which double buffering technology was used to solve the problem of elevator pictures flicker at refreshing; final y, test correctness and rationality of the system.展开更多
In this research, the vibration of elevator ropes, including the main rope and compensation rope are investigated simultaneously in a high-rise elevator system under earthquake excitation. Moreover, the paper presents...In this research, the vibration of elevator ropes, including the main rope and compensation rope are investigated simultaneously in a high-rise elevator system under earthquake excitation. Moreover, the paper presents a new control method to restrain the sway of both ropes. This study considers varying rope lengths during elevator operation which cause other system parameters such as natural frequency, and damping ratio to be time-variant variables. The dynamics of the ropes are analyzed by solving the governing non-stationary, nonlinear equation numerically. In order to mitigate the vibration of ropes in several motion conditions, particularly upwards movement, downward movement, stopped at the lowest position, and stopped at the highest position, an active equipment is installed at the compensation sheave. The stability of the system using the controller is analyzed at four states: without disturbance and static car, without disturbance and mobile car, including disturbance and static car, and including disturbance and mobile car. The efficiency of the controller used for dampening the vibration of elevator ropes is validated by numerical simulation results.展开更多
To make elevator group control system better follow the change of elevator traffic flow (ETF) in order to adjust the control strategy,the prediction method of support vector machine (SVM) in combination with phase spa...To make elevator group control system better follow the change of elevator traffic flow (ETF) in order to adjust the control strategy,the prediction method of support vector machine (SVM) in combination with phase space reconstruction has been proposed for ETF.Firstly,the phase space reconstruction for elevator traffic flow time series (ETFTS) is processed.Secondly,the small data set method is applied to calculate the largest Lyapunov exponent to judge the chaotic property of ETF.Then prediction model of ETFTS based on SVM is founded.Finally,the method is applied to predict the time series for the incoming and outgoing passenger flow respectively using ETF data collected in some building.Meanwhile,it is compared with RBF neural network model.Simulation results show that the trend of factual traffic flow is better followed by predictive traffic flow.SVM algorithm has much better prediction performance.The fitting and prediction of ETF with better effect are realized.展开更多
The computational flow rate feedback and control method, which can be used in proportional valve controlled hydraulic elevators, is discussed and analyzed. In a hydraulic elevator with this method, microprocessor rece...The computational flow rate feedback and control method, which can be used in proportional valve controlled hydraulic elevators, is discussed and analyzed. In a hydraulic elevator with this method, microprocessor receives pressure information from the pressure transducers and computes the flow rate through the proportional valve based on pressure-flow conversion real time algorithm. This hydraulic elevator is of lower cost and energy consumption than the conventional closed loop control hydraulic elevator whose flow rate is measured by a flow meter. Experiments arc carried out on a test rig which could simulate the load of hydraulic elevator. According to the experiment results, the means to modify the pressure-flow conversion algorithm are pointed out.展开更多
In order to discover the main causes of elevator group accidents in edge computing environment, a multi-dimensional data model of elevator accident data is established by using data cube technology, proposing and impl...In order to discover the main causes of elevator group accidents in edge computing environment, a multi-dimensional data model of elevator accident data is established by using data cube technology, proposing and implementing a method by combining classical Apriori algorithm with the model, digging out frequent items of elevator accident data to explore the main reasons for the occurrence of elevator accidents. In addition, a collaborative edge model of elevator accidents is set to achieve data sharing, making it possible to check the detail of each cause to confirm the causes of elevator accidents. Lastly the association rules are applied to find the law of elevator Accidents.展开更多
AIM： To describe the clinical features of congenital double elevator palsy（CDEP） and to evaluate various surgical outcomes between the standard Knapp and augmented Knapp procedures, based on improvements in primary...AIM： To describe the clinical features of congenital double elevator palsy（CDEP） and to evaluate various surgical outcomes between the standard Knapp and augmented Knapp procedures, based on improvements in primary eye position and ocular motility.METHODS： Twenty-two patients with CDEP at Shanghai Children＇s Hospital were enrolled from July 2014 to January 2018. The forced duction test（FDT） was negative in 21 patients, aged 8 mo to 12 y（mean 5.4 y）. Patients were divided into two treatment groups： 16 patients underwent the standard Knapp procedure（group A）, with or without horizontal squint procedure; and 5 patients underwent the augmented Knapp procedure（Foster procedure; group B）. One patient underwent inferior rectus recession in the affected eye and superior rectus recession in the sound eye because of a positive FDT. The pre-and postoperative vertical deviations in the primary position and ocular motility were compared in the two groups.RESULTS： Twenty-one eyes of the 22 patients（95%） were aligned within 10 prism diopters（PD）, and all patients（100%） reached ≥25% elevation improvement after surgery. The average corrected vertical deviation in group B was statistically better than that of group A. For group A, the vertical deviation in the primary position decreased from 24.75Δ±8.35Δ to 4.56Δ±8.07Δ after surgery, for an improvement of 23.06Δ±6.51Δ（P〈0.05）. In group B, the decrease was from 35.00Δ±5.00Δ（range 30Δ-40Δ） to 1.00Δ±2.24Δ, for an improvement of 34.00Δ±4.18Δ（P〈0.05）. There were significant differences between the pre-and postoperative elevation in each group（group A, P〈0.05; group B, P〈0.05）. The average scale of improved elevation in group B（1.80±0.45） was not significantly better than that of group A（1.69±0.87; Z=-0.732, P=0.548）. The average follow-up periods lasted 21 mo in group A and 18 mo in group B.CONCLUSION： For vertical deviations 〈30Δ, the standard Knapp procedure can be chosen. For deviations greater than 30Δ-40Δ, the Foster procedure should be chosen. Because of our early interference, the inferior rectus（IR） muscle did not show mechanical restriction. Monocular elevation deficiency（MED） should be diagnosed early so that complications will be reduced and the procedure will be easier for the surgeon.展开更多
In this paper, three different controllers are proposed and simulated for maglev guiding systems to have convenient and smooth elevator motion. The proposed controllers are PID, sliding mode, and PID sliding mode cont...In this paper, three different controllers are proposed and simulated for maglev guiding systems to have convenient and smooth elevator motion. The proposed controllers are PID, sliding mode, and PID sliding mode controllers. The advantages and disadvantages of the proposed controllers are discussed. Although, PID controller is fast, its response affected considerably by external disturbances. Unlike PID, the sliding mode controller is so robust, but its transient is unsuitable based on application conditions. However, an acceptable controller for ropeless elevator guiding system should guaranty the passengers safety and convenient. Consequently, the response of the system should be fast, robust, and without considerable overshoots and oscillations. These required advantages are compromised in the proposed parallel PID sliding mode controller. The affectivity of the introduced controllers for maglev guiding system is investigated through conducted simulations in MATLAB/Simulink environment. The obtained results illustrate that PID sliding mode controller is a so fast and robust controller for a ropeless elevator maglev guiding system.展开更多
In order to get a globally optimized solution for the Elevator Group Control System (EGCS) scheduling problem, an algorithm with an overall optimization function is needed. In this study, Real-time Particle Swarm Opti...In order to get a globally optimized solution for the Elevator Group Control System (EGCS) scheduling problem, an algorithm with an overall optimization function is needed. In this study, Real-time Particle Swarm Optimization (RPSO) is proposed to find an optimal solution to the EGCS scheduling problem. Different traffic patterns and controller mechanisms for EGCS are analyzed. This study focuses on up-peak traffic because of its critical importance to modern office buildings. Simulation results show that EGCS based on Multi-Agent Systems (MAS) using RPSO gives good results for up-peak EGCS scheduling problem. Besides, the elevator real-time scheduling and reallocation functions are realized based on RPSO in case new information is available or the elevator becomes busy because it is unavailable or full. This study contributes a new scheduling algorithm for EGCS, and expands the application of PSO.展开更多
The present work proposes a methodological approach for modeling decisions regarding energy reduction in an elevator. This is achieved with the integration of existing as well as acquired knowledge, in a decision modu...The present work proposes a methodological approach for modeling decisions regarding energy reduction in an elevator. This is achieved with the integration of existing as well as acquired knowledge, in a decision module implemented in the electronics of an elevator. So far, elevators do not exploit information regarding their recent usage. In the developed system decisions are driven based on information arising from monitoring the use of the elevator. Monitoring provides various records of usage which consequently are used to predict elevator’s future usage and to adapt accordingly its functioning. Till now, there are only elevators that encompass in their electronics algorithms with if then rules in order to control elevator’s functioning. However, these if then rules are based only on good practice knowledge of similar elevators installed in similar buildings. Even this knowledge which unavoidably is associated with uncertainty is not encoded in a mathematically consisted way in the algorithms. The design, the implementation and a first pilot evaluation study of an elevator’s intelligent decision module are presented. The study concludes that the presented application sufficiently reduces energy consumption through properly controlled functioning.展开更多
This paper studies the libration and stabilization of a parallel partial space elevator system in circular orbits. The system is made up of two paralleled partial space elevators, each of which consists of one main sa...This paper studies the libration and stabilization of a parallel partial space elevator system in circular orbits. The system is made up of two paralleled partial space elevators, each of which consists of one main satellite, one end body and a climber moving along the tether between them.The libration characteristics of the elevator are studied through numerical analysis by a new dynamic model, and a novel control strategy is proposed to stabilize the swing of the end body by projecting the climber speeds only. Optimal control method is used to implement the new control strategy in the case where the climbers move in opposite direction. The simulation results validate the effectiveness of the proposed control strategy whose application will neither sacrifice the transport efficiency nor exacerbate libration significantly.展开更多
A novel elevator door driven by tubular permanent magnet linear synchronous motor (TPMLSM) is presented. This TPMLSM applies axial magnet array topology of the secondary rod, air-cored armature windings and slotless s...A novel elevator door driven by tubular permanent magnet linear synchronous motor (TPMLSM) is presented. This TPMLSM applies axial magnet array topology of the secondary rod, air-cored armature windings and slotless structure of the forcer to improve the stability of the thrust. The influence of two major dimensions, the pitch and radius of the permanent magnet (PM), on magnetic field was studied and the best values were given by the finite element analysis (FEA). The magnetic field, back EMF and thrust of the motor were analyzed and the PM size was optimized to reduce the harmonic components of the magnetic field and improve the performance of the motor. Predicted results are validated by the experiment. It is shown that the performance of the motor and the novel elevator door system is satisfying.展开更多
Elevators used in ultra-high buildings are prone to vibrating due to their ultra-long traction ropes,which significantly affects the comfort and safety of high-speed elevators.Therefore,vibration of the elevator has a...Elevators used in ultra-high buildings are prone to vibrating due to their ultra-long traction ropes,which significantly affects the comfort and safety of high-speed elevators.Therefore,vibration of the elevator has always been a topic of research interest.This paper presents a theoretical model for analyzing the tension–torsion coupling vibration of the time-varying elevator traction system.The constitutive relations with the tension–torsion coupling effect of the wire rope are reduced by analyzing the deformation mechanism of the spiral winding wire rope.Based on Hamilton’s principle,the equations of motion and corresponding boundary conditions for the tension–torsion coupling vibration of the elevator traction system are derived.The Galerkin method is employed to account for the influence of nonlinear boundary conditions and to transform the equations of motion into discrete ones with variable coefficients of time,which are solved using the Newmark-βmethod.The accuracy of the proposed model is justified by the good agreement between theoretical predictions and experimental results,following which,the influence of the operation status and structural parameters of the elevator traction system on its vibration performance is discussed in detail.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.52375255,51935007)the Shanghai Rising-Star Program(Grant No.24QB2705000)。
文摘Existing elevator fault diagnosis algorithms have limited engineering applicability due to variations in working conditions and differences in equipment structures.To address this limitation,this study proposes an unsupervised subdomain adaptation method based on a time-frequency feature attention mechanism,LMMD-based subdomain alignment,and contrastive local alignment.This enables the application of the diagnosis model across different working conditions and equipment types.First,a novel time-frequency feature attention mechanism assigns weights to vibration signals of varying dimensions.Second,the time series is transformed to obtain a three-channel time-frequency diagram.This diagram is input into the proposed dimension-segmentation cross-channel multihead self-attention framework to extract high-dimensional frequencydomain fault features.These features are concatenated with the time-domain features to obtain a global feature representation.Then,the extracted high-dimensional features are sent to the classification module to obtain the predicted labels for the source and target domains.Finally,after confidence filtering,the true labels from the source domain and the prediction labels from the target domain are fed into a dynamically weighted multilevel feature alignment module to promote proximity between similar fault features across domains while enhancing separation among different fault types.The validity and superiority of the proposed method were demonstrated through simulation experiments conducted on two types of manned escalator systems under multiple working conditions.For the most challenging transfer task,the proposed method achieved higher accuracy on the target domain test set than DANN,ADDA,C-CLCN,TFA-CCN,and TFA-LCN by 26.87%,24.72%,11.44%,28.94%,and 16.85%,respectively.
基金College Students’Innovation and Entrepreneurship Training Program of Jinzhong University。
文摘With the acceleration of urbanization and the increasing number of high-rise buildings,elevators,as key equipment for vertical transportation,have attracted significant attention regarding the safety,reliability,and efficiency of their operation.This design develops a four-floor elevator control system based on S7-200PLC.It realizes the following functions:the second and third floors support both upward and downward request functions(with corresponding indicator lights turning on),the first floor only supports the upward request function,and the fourth floor only supports the downward request function.Meanwhile,the elevator automatically opens its door after arriving at each floor and closes the door automatically 6 seconds later.The design aims to achieve precise control and efficient operation of the elevator.
文摘With the continuous development and wide application of modern technology,more enterprises and institutions in our country have begun to strengthen the research and manufacturing of intelligent elevators,aiming to build a new mode of modern manufacturing with the concept of green development as the core.Therefore,this paper takes green manufacturing as the background,analyzes the design significance of intelligent elevator lightweight,expounds its design ideas,and in the end introduces its specific design practice path.
基金funded by the National Natural Science Foundation of China(12102487)Basic and Applied Basic Research Foundation of Guangdong Province,China(2023A1515012339)+1 种基金Shenzhen Science and Technology Program(ZDSYS20210623091808026)the Discovery Grant(RGPIN-2024-06290)of the Natural Sciences and Engineering Research Council of Canada。
文摘This paper proposed a new libration decoupling analytical speed function(LD-ASF)in lieu of the classic analytical speed function to control the climber's speed along a partial space elevator to improve libration stability in cargo transportation.The LD-ASF is further optimized for payload transportation efficiency by a novel coordinate game theory to balance competing control objectives among payload transport speed,stable end body's libration,and overall control input via model predictive control.The transfer period is divided into several sections to reduce computational burden.The validity and efficacy of the proposed LD-ASF and coordinate game-based model predictive control are demonstrated by computer simulation.Numerical results reveal that the optimized LD-ASF results in higher transportation speed,stable end body's libration,lower thrust fuel consumption,and more flexible optimization space than the classic analytical speed function.
基金National Key Research and Development Program of China (2022YFC3004004)National Natural Science Foundation of China (42075155,12241104)National Natural Science Foundation of China Joint Fund (U2342213)。
文摘The infrared channels of the FY-4B advanced geosynchronous radiation imagers(AGRI) play a crucial role in temperature and humidity analyses for mesoscale numerical weather prediction, particularly in enhancing the initial field quality and the forecasting accuracy of the model. This study assimilated FY-4B AGRI data into the CMA-MESO model and analyzed the bias characteristics and correction methods. Analysis of the AGRI data revealed a clear diurnal variation in the bias, which was positively correlated with the solar elevation angle. However, the diurnal variation in the bias lagged behind the solar elevation angle, likely owing to temperature changes and delayed instrument responses resulting from solar radiation. To address this issue, we propose a correction method that utilizes the solar elevation angle after an optimal time shift. Using the time-shifted solar elevation angle as a predictor effectively reduces the diurnal variation in bias and significantly improves the correction effect. This approach provides theoretical support for the assimilation of FY-4B AGRI data into mesoscale numerical weather predictions, thereby enhancing the reliability of the assimilation results.
基金Under the auspices of the National Natural Science Foundation of China(No.42430511,U20A2083)the National Key Research and Development Program of China(No.2022YFF1300900)the Science and Technology Development Program of Jilin Province(No.20210509037RQ,20230101348JC)。
文摘Elevation patterns and assembly processes of soil microbial community structures are essential for understanding biogeo-chemical processes in mountain systems.Differences in soil properties caused by elevation gradients can regulate the spatial distribu-tion and network complexity of the community structure.To explore the variations in soil microbial community structures and their as-sembly mechanisms across different elevations of the Changbai Mountains,as well as their responses to environmental factors,we col-lected microbial samples along an elevational gradient(seven elevations containing four vegetation zones)on the western slope of the Changbai Mountains using the method of metagenomic sequencing.The results showed a significant difference(P<0.05)for the Chao1 index across different elevations,but no significant difference was observed for the Shannon and Simpson indices.With increasing elev-ation,the number of nodes and links in the microbial network gradually decreased.Acidobacteria were highly connected to many nodes.The microbial communities indicated a significant distance-decay relationship(P<0.001)and were affected more by stochastic pro-cesses along the elevation gradient.The results of the Structural Equation Model(SEM)showed that elevation had direct significant ef-fect on carbon(C,P<0.01),nitrogen(N,P<0.01),and phosphorus(P,P<0.05)and weak negative effect on their ecological stoi-chiometry.Elevation was one of the major variables contributing to microbial network topology.The contribution of C and N to micro-bial network complexity was higher than that of P.Our study provides valuable insights into the responses of soil microbial communit-ies to elevation variations.
基金supported by the Guangdong-Hong Kong Joint Laboratory for Carbon Neutrality(No.2023B1212120003)the Guangdong Talent Program(No.2023JC10N060)+1 种基金the Guangdong Science and Technology Program(No.2022B1212040001)the Special Fund for Science and Technology Innovation Strategy of Guangdong Province(Grant No.2022660500250009604)。
文摘Increasing atmospheric CO_(2)concentrations from~280 ppm in the pre-industrial era to over 420 ppm today, and projected to exceed 550 ppm by 2050(IPCC, 2023), are transforming the biochemical context of plant metabolism,causing restructuring of carbon and nitrogen balance in crops. Though elevated CO_(2)(eCO_(2)) increases photosynthetic efficacy and biomass accumulation in many C3crops, it also disrupts carbon-nitrogen balance, leading to nitrogen dilution in leaves and grains, eventually compromising food quality(Myers et al., 2014;Rezaei et al., 2023). Rice is a staple food that feeds nearly half of the world's population;it requires sustained yield gains, considering an estimated 35%-56%increase in demand by 2050, as the global population approaches 10 billion(Van Dijk et al., 2021), while reducing dependency on nitrogen fertilizers, whose production and overuse contribute significantly to greenhouse gas emission(Qian et al., 2023). Yet, most breeding programs remain regulated to present-day atmospheric conditions, overlooking the physiological and molecular adaptations required for future CO_(2)climates.
文摘A new instrument for checking the quality of elevator guide rails is introduced.With this instrument,the general geometric errors such as straightness,flatness,squareness,twist,thickness and height can be measured automatically,simultaneously in a short time with high accuracy.It is very useful for elevator guide rail factories to improve their work efficiency and the quality of their products.
基金Supported by the Principal Fund Project of Tarim University(TDZKSSZD201207)~~
文摘The aim of the study is to simulate actual operation of an elevator. First, it designed elevator scheduling algorithm for control ing operation of the elevator;second, it simulated elevator operation by the use of object-oriented programming language, in which double buffering technology was used to solve the problem of elevator pictures flicker at refreshing; final y, test correctness and rationality of the system.
文摘In this research, the vibration of elevator ropes, including the main rope and compensation rope are investigated simultaneously in a high-rise elevator system under earthquake excitation. Moreover, the paper presents a new control method to restrain the sway of both ropes. This study considers varying rope lengths during elevator operation which cause other system parameters such as natural frequency, and damping ratio to be time-variant variables. The dynamics of the ropes are analyzed by solving the governing non-stationary, nonlinear equation numerically. In order to mitigate the vibration of ropes in several motion conditions, particularly upwards movement, downward movement, stopped at the lowest position, and stopped at the highest position, an active equipment is installed at the compensation sheave. The stability of the system using the controller is analyzed at four states: without disturbance and static car, without disturbance and mobile car, including disturbance and static car, and including disturbance and mobile car. The efficiency of the controller used for dampening the vibration of elevator ropes is validated by numerical simulation results.
基金Sponsored by the National Eleventh Five year Plan Key Project of Ministry of Science and Technology of China (Grant No. 2006BAJ03A05-05)
文摘To make elevator group control system better follow the change of elevator traffic flow (ETF) in order to adjust the control strategy,the prediction method of support vector machine (SVM) in combination with phase space reconstruction has been proposed for ETF.Firstly,the phase space reconstruction for elevator traffic flow time series (ETFTS) is processed.Secondly,the small data set method is applied to calculate the largest Lyapunov exponent to judge the chaotic property of ETF.Then prediction model of ETFTS based on SVM is founded.Finally,the method is applied to predict the time series for the incoming and outgoing passenger flow respectively using ETF data collected in some building.Meanwhile,it is compared with RBF neural network model.Simulation results show that the trend of factual traffic flow is better followed by predictive traffic flow.SVM algorithm has much better prediction performance.The fitting and prediction of ETF with better effect are realized.
基金This project is supported by State Scientific Project of the Tenth Five-year Plan of China(No.2002BA208B02)National Natural Science Foundation of China(No.50305032).
文摘The computational flow rate feedback and control method, which can be used in proportional valve controlled hydraulic elevators, is discussed and analyzed. In a hydraulic elevator with this method, microprocessor receives pressure information from the pressure transducers and computes the flow rate through the proportional valve based on pressure-flow conversion real time algorithm. This hydraulic elevator is of lower cost and energy consumption than the conventional closed loop control hydraulic elevator whose flow rate is measured by a flow meter. Experiments arc carried out on a test rig which could simulate the load of hydraulic elevator. According to the experiment results, the means to modify the pressure-flow conversion algorithm are pointed out.
文摘In order to discover the main causes of elevator group accidents in edge computing environment, a multi-dimensional data model of elevator accident data is established by using data cube technology, proposing and implementing a method by combining classical Apriori algorithm with the model, digging out frequent items of elevator accident data to explore the main reasons for the occurrence of elevator accidents. In addition, a collaborative edge model of elevator accidents is set to achieve data sharing, making it possible to check the detail of each cause to confirm the causes of elevator accidents. Lastly the association rules are applied to find the law of elevator Accidents.
文摘AIM： To describe the clinical features of congenital double elevator palsy（CDEP） and to evaluate various surgical outcomes between the standard Knapp and augmented Knapp procedures, based on improvements in primary eye position and ocular motility.METHODS： Twenty-two patients with CDEP at Shanghai Children＇s Hospital were enrolled from July 2014 to January 2018. The forced duction test（FDT） was negative in 21 patients, aged 8 mo to 12 y（mean 5.4 y）. Patients were divided into two treatment groups： 16 patients underwent the standard Knapp procedure（group A）, with or without horizontal squint procedure; and 5 patients underwent the augmented Knapp procedure（Foster procedure; group B）. One patient underwent inferior rectus recession in the affected eye and superior rectus recession in the sound eye because of a positive FDT. The pre-and postoperative vertical deviations in the primary position and ocular motility were compared in the two groups.RESULTS： Twenty-one eyes of the 22 patients（95%） were aligned within 10 prism diopters（PD）, and all patients（100%） reached ≥25% elevation improvement after surgery. The average corrected vertical deviation in group B was statistically better than that of group A. For group A, the vertical deviation in the primary position decreased from 24.75Δ±8.35Δ to 4.56Δ±8.07Δ after surgery, for an improvement of 23.06Δ±6.51Δ（P〈0.05）. In group B, the decrease was from 35.00Δ±5.00Δ（range 30Δ-40Δ） to 1.00Δ±2.24Δ, for an improvement of 34.00Δ±4.18Δ（P〈0.05）. There were significant differences between the pre-and postoperative elevation in each group（group A, P〈0.05; group B, P〈0.05）. The average scale of improved elevation in group B（1.80±0.45） was not significantly better than that of group A（1.69±0.87; Z=-0.732, P=0.548）. The average follow-up periods lasted 21 mo in group A and 18 mo in group B.CONCLUSION： For vertical deviations 〈30Δ, the standard Knapp procedure can be chosen. For deviations greater than 30Δ-40Δ, the Foster procedure should be chosen. Because of our early interference, the inferior rectus（IR） muscle did not show mechanical restriction. Monocular elevation deficiency（MED） should be diagnosed early so that complications will be reduced and the procedure will be easier for the surgeon.
文摘In this paper, three different controllers are proposed and simulated for maglev guiding systems to have convenient and smooth elevator motion. The proposed controllers are PID, sliding mode, and PID sliding mode controllers. The advantages and disadvantages of the proposed controllers are discussed. Although, PID controller is fast, its response affected considerably by external disturbances. Unlike PID, the sliding mode controller is so robust, but its transient is unsuitable based on application conditions. However, an acceptable controller for ropeless elevator guiding system should guaranty the passengers safety and convenient. Consequently, the response of the system should be fast, robust, and without considerable overshoots and oscillations. These required advantages are compromised in the proposed parallel PID sliding mode controller. The affectivity of the introduced controllers for maglev guiding system is investigated through conducted simulations in MATLAB/Simulink environment. The obtained results illustrate that PID sliding mode controller is a so fast and robust controller for a ropeless elevator maglev guiding system.
文摘In order to get a globally optimized solution for the Elevator Group Control System (EGCS) scheduling problem, an algorithm with an overall optimization function is needed. In this study, Real-time Particle Swarm Optimization (RPSO) is proposed to find an optimal solution to the EGCS scheduling problem. Different traffic patterns and controller mechanisms for EGCS are analyzed. This study focuses on up-peak traffic because of its critical importance to modern office buildings. Simulation results show that EGCS based on Multi-Agent Systems (MAS) using RPSO gives good results for up-peak EGCS scheduling problem. Besides, the elevator real-time scheduling and reallocation functions are realized based on RPSO in case new information is available or the elevator becomes busy because it is unavailable or full. This study contributes a new scheduling algorithm for EGCS, and expands the application of PSO.
文摘The present work proposes a methodological approach for modeling decisions regarding energy reduction in an elevator. This is achieved with the integration of existing as well as acquired knowledge, in a decision module implemented in the electronics of an elevator. So far, elevators do not exploit information regarding their recent usage. In the developed system decisions are driven based on information arising from monitoring the use of the elevator. Monitoring provides various records of usage which consequently are used to predict elevator’s future usage and to adapt accordingly its functioning. Till now, there are only elevators that encompass in their electronics algorithms with if then rules in order to control elevator’s functioning. However, these if then rules are based only on good practice knowledge of similar elevators installed in similar buildings. Even this knowledge which unavoidably is associated with uncertainty is not encoded in a mathematically consisted way in the algorithms. The design, the implementation and a first pilot evaluation study of an elevator’s intelligent decision module are presented. The study concludes that the presented application sufficiently reduces energy consumption through properly controlled functioning.
基金supported by the Discovery Grant (No. RGPIN2018-05991)Discovery Accelerate Supplement Grant (No. RGPAS-2018-522709) of Natural Sciences and Engineering Research Council of CanadaGuangdong Basic and Applied Basic Research Foundation (No. 2019A1515111056)。
文摘This paper studies the libration and stabilization of a parallel partial space elevator system in circular orbits. The system is made up of two paralleled partial space elevators, each of which consists of one main satellite, one end body and a climber moving along the tether between them.The libration characteristics of the elevator are studied through numerical analysis by a new dynamic model, and a novel control strategy is proposed to stabilize the swing of the end body by projecting the climber speeds only. Optimal control method is used to implement the new control strategy in the case where the climbers move in opposite direction. The simulation results validate the effectiveness of the proposed control strategy whose application will neither sacrifice the transport efficiency nor exacerbate libration significantly.
基金Project (No. 50607016) supported by the National Natural ScienceFoundation of China
文摘A novel elevator door driven by tubular permanent magnet linear synchronous motor (TPMLSM) is presented. This TPMLSM applies axial magnet array topology of the secondary rod, air-cored armature windings and slotless structure of the forcer to improve the stability of the thrust. The influence of two major dimensions, the pitch and radius of the permanent magnet (PM), on magnetic field was studied and the best values were given by the finite element analysis (FEA). The magnetic field, back EMF and thrust of the motor were analyzed and the PM size was optimized to reduce the harmonic components of the magnetic field and improve the performance of the motor. Predicted results are validated by the experiment. It is shown that the performance of the motor and the novel elevator door system is satisfying.
基金supported by the Guangdong Natural Science Foundation(No.2021A1515012037).
文摘Elevators used in ultra-high buildings are prone to vibrating due to their ultra-long traction ropes,which significantly affects the comfort and safety of high-speed elevators.Therefore,vibration of the elevator has always been a topic of research interest.This paper presents a theoretical model for analyzing the tension–torsion coupling vibration of the time-varying elevator traction system.The constitutive relations with the tension–torsion coupling effect of the wire rope are reduced by analyzing the deformation mechanism of the spiral winding wire rope.Based on Hamilton’s principle,the equations of motion and corresponding boundary conditions for the tension–torsion coupling vibration of the elevator traction system are derived.The Galerkin method is employed to account for the influence of nonlinear boundary conditions and to transform the equations of motion into discrete ones with variable coefficients of time,which are solved using the Newmark-βmethod.The accuracy of the proposed model is justified by the good agreement between theoretical predictions and experimental results,following which,the influence of the operation status and structural parameters of the elevator traction system on its vibration performance is discussed in detail.
