The beam pumping unit(BPU)remains the most stable and reliable equipment for crude oil lifting.Despite its simple four-link mechanism,the structural design of the BPU presents a constrained single-objective optimizati...The beam pumping unit(BPU)remains the most stable and reliable equipment for crude oil lifting.Despite its simple four-link mechanism,the structural design of the BPU presents a constrained single-objective optimization problem.Currently,a comprehensive framework for the structural design and optimization of compound balanced BPUs is lacking.Therefore,this study proposes a novel structural design scheme for BPUs,aiming to meet the practical needs of designers and operators by sequentially optimizing both the dynamic characteristics and balance properties of the BPUs.A dynamic model of compound balanced BPU was established based on D'Alembert's principle.The constraints for structural dimensions were formulated based on the actual operational requirements and design experience with BPUs.To optimize the structure,three algorithms were employed:the particle swarm optimization(PSO)algorithm,the genetic algorithm(GA),and the gray wolf optimization(GWO)algorithm.Each newly generated individuals are regulated by constraints to ensure the rationality of the outcomes.Furthermore,the integration of three algorithms ensures the increased likelihood of attaining the global optimal solution.The polished rod acceleration of the optimized structure is significantly reduced,and the dynamic characteristics of the up and down strokes are essentially symmetrical.Additionally,these three algorithms are also applied to the balance optimization of BPUs based on the measured dynamometer card.The calculation results demonstrate that the GWO-based optimization method exhibits excellent robustness in terms of structural optimization by enhancing the operational smoothness of the BPU,as well as in balance optimization by achieving energy conservation.By applying the optimization scheme proposed in this paper,the CYJW7-3-23HF type of BPU was designed,achieving a maximum polished rod acceleration of±0.675 m/s^(2) when operating at a stroke of 6 min^(−1).When deployed in two wells,the root-mean-square(RMS)torque was minimized,reaching values of 7.539 kN·m and 12.921 kN·m,respectively.The proposed design method not only contributes to the personalized customization but also improves the design efficiency of compound balanced BPUs.展开更多
Additive manufacturing(AM),particularly fused deposition modeling(FDM),has emerged as a transformative technology in modern manufacturing processes.The dimensional accuracy of FDM-printed parts is crucial for ensuring...Additive manufacturing(AM),particularly fused deposition modeling(FDM),has emerged as a transformative technology in modern manufacturing processes.The dimensional accuracy of FDM-printed parts is crucial for ensuring their functional integrity and performance.To achieve sustainable manufacturing in FDM,it is necessary to optimize the print quality and time efficiency concurrently.However,owing to the complex interactions of printing parameters,achieving a balanced optimization of both remains challenging.This study examines four key factors affecting dimensional accuracy and print time:printing speed,layer thickness,nozzle temperature,and bed temperature.Fifty parameter sets were generated using enhanced Latin hypercube sampling.A whale optimization algorithm(WOA)-enhanced support vector regression(SVR)model was developed to predict dimen-sional errors and print time effectively,with non-dominated sorting genetic algorithm Ⅲ(NSGA-Ⅲ)utilized for multi-objective optimization.The technique for Order Preference by Similarity to Ideal Solution(TOPSIS)was applied to select a balanced solution from the Pareto front.In experimental validation,the parts printed using the optimized parameters exhibited excellent dimensional accuracy and printing efficiency.This study comprehensively considered optimizing the printing time and size to meet quality requirements while achieving higher printing efficiency and aiding in the realization of sustainable manufacturing in the field of AM.In addition,the printing of a specific prosthetic component was used as a case study,highlighting the high demands on both dimensional precision and printing efficiency.The optimized process parameters required significantly less printing time,while satisfying the dimensional accuracy requirements.This study provides valuable insights for achieving sustainable AM using FDM.展开更多
The conventional traveling beam balance pumping unit in the pumping unit has the following main characteristics in operation: (1) Simple structure;(2) Easy to repair;(3) Good stability in operation. The disadvantage i...The conventional traveling beam balance pumping unit in the pumping unit has the following main characteristics in operation: (1) Simple structure;(2) Easy to repair;(3) Good stability in operation. The disadvantage is that the bearing capacity in the operation process depends on the bending action torque to exert the action, which results in more difficulty in matching the loads of the pumping units, and the interaction balance rod of the pumping units is also subjected to strict restriction, which results in greater loss of material and energy in the operation process of the pumping units. Therefore, when the conventional traveling beam balance pumping units are reformed, It is required to start with the two major improvement models, namely, the downward bias barbell improvement model and the double horsehead improvement model. The two major improvement models are characterized by not changing the previous interaction balance model, which in turn results in the fact that the essential contradiction problem of the pumping unit has not been solved. In terms of the improvement of the driving force of the pumping unit, the author, based on the currently prevailing linear motor control equipment, carries out the improvement for the conventional traveling beam balance pumping unit, replacing the previous rotary motor control equipment with the linear motor control equipment to improve the overall efficiency contradiction problem of the old traditional type of pumping unit.展开更多
In the face of harsh natural environment applications such as earth-orbiting and deep space satellites, underwater sea vehicles, strong electromagnetic interference and temperature stress,the circuits faults appear ea...In the face of harsh natural environment applications such as earth-orbiting and deep space satellites, underwater sea vehicles, strong electromagnetic interference and temperature stress,the circuits faults appear easily. Circuit faults will inevitably lead to serious losses of availability or impeded mission success without self-repair over the mission duration. Traditional fault-repair methods based on redundant fault-tolerant technique are straightforward to implement, yet their area, power and weight cost can be excessive. Moreover they utilize all plug-in or component level circuits to realize redundant backup, such that their applicability is limited. Hence, a novel selfrepair technology based on evolvable hardware（EHW） and reparation balance technology（RBT） is proposed. Its cost is low, and fault self-repair of various circuits and devices can be realized through dynamic configuration. Making full use of the fault signals, correcting circuit can be found through EHW technique to realize the balance and compensation of the fault output-signals. In this paper, the self-repair model was analyzed which based on EHW and RBT technique, the specific self-repair strategy was studied, the corresponding self-repair circuit fault system was designed, and the typical faults were simulated and analyzed which combined with the actual electronic devices. Simulation results demonstrated that the proposed fault self-repair strategy was feasible. Compared to traditional techniques, fault self-repair based on EHW consumes fewer hardware resources, and the scope of fault self-repair was expanded significantly.展开更多
Sampling ports were firstly drilled on a ZGM95 coal mill in the power plant in China, and the coal samples from various points in the pulverizer were collected under the different operation conditions. The prop- erty ...Sampling ports were firstly drilled on a ZGM95 coal mill in the power plant in China, and the coal samples from various points in the pulverizer were collected under the different operation conditions. The prop- erty of the sampling material from the mill was analyzed, applying the float-sink test, size distribution analysis, proximate analysis and so on. It was indicated that the ＋250 I^m fraction in the pulverized fuel accounted for only 0.02%, while it was 83.2% in the new feed. The circulating ratio and coal flow in the separator and the cone zone were calculated using the mass balance of the circulating load. So, the cir- culating ratio in the separator of the pulverizer was between 8 and 13, and the circulating ratio, the feed flow of separator and cone zone all raised with the increase of the air volume. Furthermore, the parameters of the separation functions were obtained based on the fitting method. It was shown that the mean value of the shape factor B was 0.7617, and the parameter D which is the particle size at 50% cumulative yield in the separator almost kept unchanged.展开更多
Line configuration and balancing is to select the type of line and allot a given set of operations as well as machines to a sequence of workstations to realize high-efficiency production. Most of the current researche...Line configuration and balancing is to select the type of line and allot a given set of operations as well as machines to a sequence of workstations to realize high-efficiency production. Most of the current researches for machining line configuration and balancing problems are related to dedicated transfer lines with dedicated machine workstations. With growing trends towards great product variety and fluctuations in market demand, dedicated transfer lines are being replaced with flexible machining line composed of identical CNC machines. This paper deals with the line configuration and balancing problem for flexible machining lines. The objective is to assign operations to workstations and find the sequence of execution, specify the number of machines in each workstation while minimizing the line cycle time and total number of machines. This problem is subject to precedence, clustering, accessibility and capacity constraints among the features, operations, setups and workstations. The mathematical model and heuristic algorithm based on feature group strategy and polychromatic sets theory are presented to find an optimal solution. The feature group strategy and polychromatic sets theory are used to establish constraint model. A heuristic operations sequencing and assignment algorithm is given. An industrial case study is carried out, and multiple optimal solutions in different line configurations are obtained. The case studying results show that the solutions with shorter cycle time and higher line balancing rate demonstrate the feasibility and effectiveness of the proposed algorithm. This research proposes a heuristic line configuration and balancing algorithm based on feature group strategy and polychromatic sets theory which is able to provide better solutions while achieving an improvement in computing time.展开更多
Geothermal energy,a kind of clean and environmentally friendly energy source,is an important object of future natural resource development and utilization,among which,hot dry rock is one of the important deep geotherm...Geothermal energy,a kind of clean and environmentally friendly energy source,is an important object of future natural resource development and utilization,among which,hot dry rock is one of the important deep geothermal resources.In the current multi-objective optimization of heat extraction performance,reservoir production models are less considered and the effects of different optimization ideas are not compared comprehensively.To improve the heat extraction efficiency and prolong the exploitation life of geothermal reservoirs,this paper determines the appropriate operating parameters of geothermal system(injection temperature,injection rate,production pressure and injection-production well spacing)based on the coupled thermal-hydraulic-mechanical model of hot dry rock exploitation in the Gonghe area of Qinghai and three heat extraction optimization methods.In addition,the heat extraction performances of different schemes are comparatively evaluated.And the following research results are obtained.First,the sensitivity analysis of injection and production parameters shows that power generation and recovery factor are in a reverse relation with injection-production pressure difference,which is the direct reason for the adoption of multiobjective optimization.Second,the optimization scheme prepared on the basis of parametric study indicates that the shortest life of a geothermal reservoir is 10 years,the injection-production pressure difference is up to 67 MPa,there is a significant thermal breakthrough phenomenon and the reservoir safety faces challenges.Third,by virtue of multi-objective optimization and decision making integration,the optimal operation parameter combination of hot dry rock system is determined,the life of geothermal reservoirs can exceed 20 years and balanced optimization is achieved.In conclusion,the idea of multi-objective optimization is feasible and applicable to geothermal energy exploitation and this method provides a reference for the efficient geothermal energy development and utilization and is helpful to the realization of“double carbon”goal in China.展开更多
The working platforms supported with multiple extensible legs must be leveled before they come into operation.Although the supporting stiffness and reliability of the platform are improved with the increasing number o...The working platforms supported with multiple extensible legs must be leveled before they come into operation.Although the supporting stiffness and reliability of the platform are improved with the increasing number of the supporting legs,the increased overdetermination of the multi-leg platform systems leads to leveling coupling problem among legs and virtual leg problem in which some of the supporting legs bear zero or quasi zero loads.These problems make it quite complex and time consuming to level such a multi-leg platform.Based on rigid body kinematics,an approximate equation is formulated to rapidly calculate the leg extension for leveling a rigid platform,then a proportional speed control strategy is proposed to reduce the unexpected platform distortion and leveling coupling between supporting legs.Taking both the load coupling between supporting legs and the elastic flexibility of the working platform into consideration,an optimal balancing legs’ loads(OBLL) model is firstly put forward to deal with the traditional virtual leg problem.By taking advantage of the concept of supporting stiffness matrix,a coupling extension method(CEM) is developed to solve this OBLL problem for multi-leg flexible platform.At the end,with the concept of supporting stiffness matrix and static transmissibility matrix,an optimal load balancing leveling method is proposed to achieve geometric leveling and legs’ loads balancing simultaneously.Three numerical examples are given out to illustrate the performance of proposed methods.This paper proposes a method which can effectively quantify all of the legs’ extension at the same time,achieve geometric leveling and legs’ loads balancing simultaneously.By using the proposed methods,the stability,precision and efficiency of auto-leveling control process can be improved.展开更多
In order to realize an optimal balance between the efficiency and reliability requirements ofroad models,a road modeling method for digital maps based on cardinal spline is studied.First,the cardinal spline is chosen ...In order to realize an optimal balance between the efficiency and reliability requirements ofroad models,a road modeling method for digital maps based on cardinal spline is studied.First,the cardinal spline is chosen to establish an initial road model,which is specified by a series of control points and tension parameters.Then,in view of the initial road model,a gradual optimization algorithm,which can determine the reasonable control points and optimal tension parameters according to the degree of the change of road curvature,is proposed to determine the final road model.Finally,the proposed road modeling method is verified a d evaluated through experiments,and it is compared with the conventional method for digital maps based on the B-spline.The results show that the proposed method can resize a neaoptimal balance between the efficiency and reliability requirements.Compared with the conventional method based on the B-spline,this method occupies less data storage and achieves higher accuracy.展开更多
Reconfigurable products and manufacturing systems have enabled manufacturers to provide ＂cost effective＂ variety to the market. In spite of these new technologies, the expense of manufacturing makes it infeasible to...Reconfigurable products and manufacturing systems have enabled manufacturers to provide ＂cost effective＂ variety to the market. In spite of these new technologies, the expense of manufacturing makes it infeasible to supply all the possible variants to the market for some industries. Therefore, the determination of the right number of product variantsto offer in the product portfolios becomes an important consideration. The product portfolio planning problem had been independently well studied from marketing and engineering perspectives. However, advantages can be gained from using a concurrent marketing and engineering approach. Concurrent product development strategies specifically for reconfigurable products and manufacturing systems can allow manufacturers to select best product portfolios from marketing, product design and manufacturing perspectives. A methodology for the concurrent design of a product portfolio and assembly system is presented. The objective of the concurrent product portfolio planning and assembly system design problem is to obtain the product variants that will make up the product portfolio such that oversupply of optional modules is minimized and the assembly line efficiency is maximized. Explicit design of the assembly system is obtained during the solution of the problem. It is assumed that the demand for optional modules and the assembly times for these modules are known a priori. A genetic algorithm is used in the solution of the problem. The basic premise of this methodology is that the selected product portfolio has a significant impact on the solution of the assembly line balancing problem. An example is used to validate this hypothesis. The example is then further developed to demonstrate how the methodology can be used to obtain the optimal product portfolio. This approach is intended for use by manufacturers during the early design stages of product family design.展开更多
This article presents an improved Elman neural network for reducing building vibrations during earthquakes.The adjustment coefficient is proposed to be added to the Elman network’s output layer to improve the control...This article presents an improved Elman neural network for reducing building vibrations during earthquakes.The adjustment coefficient is proposed to be added to the Elman network’s output layer to improve the controller’s performance when used to minimize vibrations in buildings.The parameters of the proposed Elman neural network model are optimized using the Balancing Composite Motion Optimization algorithm.The effectiveness of the proposed method is assessed using a three-story structure with an active dampening mechanism on the first level.The study also takes into account two kinds of Elman neural network input variables:displacement and velocity data on the first floor,as well as displacement and velocity readings across all three floors.This research uses two measures of fitness functions in the optimal process,the structure’s peak displacement and acceleration,to determine the best parameters for the proposed model.The effectiveness of the proposed method is demonstrated in restraining the vibration of the structure under a variety of earthquakes.Furthermore,the findings indicate that the proposed model maintains sustainability even when the maximum value of the actuator device is dropped.展开更多
Circularly polarized light(CPL)detectors based on chiral organic materials or inorganic structures hold great potential for highly integrated on-chip applications;however,these devices usually have to seek an optimal ...Circularly polarized light(CPL)detectors based on chiral organic materials or inorganic structures hold great potential for highly integrated on-chip applications;however,these devices usually have to seek an optimal balance among the asymmetry factor(g),responsivity(R),and stability.Here,we aim to break such a limitation by combining chiral inorganic plasmonic metamaterials with electrical gain,by which one can enhance both g and R while simultaneously securing the stability.We demonstrate a CPL detector based on"S"-shaped chiral Ag nanowires/InAs/Si heterostructures,where the meticulous construction of the"S"-shaped chiral Ag nanowires with the overlaying InAs channel enables a substantial absorption asymmetry in InAs due to differentiated localized surface plasmon resonances excited by left-and right-circularly polarized(LCP and RCP)light.The InAs serves as a conductive channel,achieving significant electrical gain through photoconductive effects assisted by photogating,gate modulation,and trap effects.The proposed inorganic stable device exhibits a high electrical g of~1.56,an ultra-high R of~33,900 A W^(-1),a large specific detectivity of~1.8×10^(11) Jones,and an ultra-short response time of~23 ns,with the high performance achieved in a broad spectral range from 2μm to 2.8μm.Ultimately,by encoding ASCII code 1 and 0 onto LCP and RCP light,respectively,and leveraging the device's heightened discrimination and response performance to these polarizations,we demonstrate a simple yet key-free optical encryption communication scheme at the device level,highlighting its extensive potential for system-level applications.展开更多
基金supported by the Key Laboratory of Petroleum and Natural Gas Equipment,Ministry of Education(No.OGE202303-08)Engineering Technology Research Center for Industrial Internet of Things and Intelligent Sensing,Hubei Province(No.KXZ 202203).
文摘The beam pumping unit(BPU)remains the most stable and reliable equipment for crude oil lifting.Despite its simple four-link mechanism,the structural design of the BPU presents a constrained single-objective optimization problem.Currently,a comprehensive framework for the structural design and optimization of compound balanced BPUs is lacking.Therefore,this study proposes a novel structural design scheme for BPUs,aiming to meet the practical needs of designers and operators by sequentially optimizing both the dynamic characteristics and balance properties of the BPUs.A dynamic model of compound balanced BPU was established based on D'Alembert's principle.The constraints for structural dimensions were formulated based on the actual operational requirements and design experience with BPUs.To optimize the structure,three algorithms were employed:the particle swarm optimization(PSO)algorithm,the genetic algorithm(GA),and the gray wolf optimization(GWO)algorithm.Each newly generated individuals are regulated by constraints to ensure the rationality of the outcomes.Furthermore,the integration of three algorithms ensures the increased likelihood of attaining the global optimal solution.The polished rod acceleration of the optimized structure is significantly reduced,and the dynamic characteristics of the up and down strokes are essentially symmetrical.Additionally,these three algorithms are also applied to the balance optimization of BPUs based on the measured dynamometer card.The calculation results demonstrate that the GWO-based optimization method exhibits excellent robustness in terms of structural optimization by enhancing the operational smoothness of the BPU,as well as in balance optimization by achieving energy conservation.By applying the optimization scheme proposed in this paper,the CYJW7-3-23HF type of BPU was designed,achieving a maximum polished rod acceleration of±0.675 m/s^(2) when operating at a stroke of 6 min^(−1).When deployed in two wells,the root-mean-square(RMS)torque was minimized,reaching values of 7.539 kN·m and 12.921 kN·m,respectively.The proposed design method not only contributes to the personalized customization but also improves the design efficiency of compound balanced BPUs.
基金supporteded by Natural Science Foundation of Shanghai(Grant No.22ZR1463900)State Key Laboratory of Mechanical System and Vibration(Grant No.MSV202318)the Fundamental Research Funds for the Central Universities(Grant No.22120220649).
文摘Additive manufacturing(AM),particularly fused deposition modeling(FDM),has emerged as a transformative technology in modern manufacturing processes.The dimensional accuracy of FDM-printed parts is crucial for ensuring their functional integrity and performance.To achieve sustainable manufacturing in FDM,it is necessary to optimize the print quality and time efficiency concurrently.However,owing to the complex interactions of printing parameters,achieving a balanced optimization of both remains challenging.This study examines four key factors affecting dimensional accuracy and print time:printing speed,layer thickness,nozzle temperature,and bed temperature.Fifty parameter sets were generated using enhanced Latin hypercube sampling.A whale optimization algorithm(WOA)-enhanced support vector regression(SVR)model was developed to predict dimen-sional errors and print time effectively,with non-dominated sorting genetic algorithm Ⅲ(NSGA-Ⅲ)utilized for multi-objective optimization.The technique for Order Preference by Similarity to Ideal Solution(TOPSIS)was applied to select a balanced solution from the Pareto front.In experimental validation,the parts printed using the optimized parameters exhibited excellent dimensional accuracy and printing efficiency.This study comprehensively considered optimizing the printing time and size to meet quality requirements while achieving higher printing efficiency and aiding in the realization of sustainable manufacturing in the field of AM.In addition,the printing of a specific prosthetic component was used as a case study,highlighting the high demands on both dimensional precision and printing efficiency.The optimized process parameters required significantly less printing time,while satisfying the dimensional accuracy requirements.This study provides valuable insights for achieving sustainable AM using FDM.
文摘The conventional traveling beam balance pumping unit in the pumping unit has the following main characteristics in operation: (1) Simple structure;(2) Easy to repair;(3) Good stability in operation. The disadvantage is that the bearing capacity in the operation process depends on the bending action torque to exert the action, which results in more difficulty in matching the loads of the pumping units, and the interaction balance rod of the pumping units is also subjected to strict restriction, which results in greater loss of material and energy in the operation process of the pumping units. Therefore, when the conventional traveling beam balance pumping units are reformed, It is required to start with the two major improvement models, namely, the downward bias barbell improvement model and the double horsehead improvement model. The two major improvement models are characterized by not changing the previous interaction balance model, which in turn results in the fact that the essential contradiction problem of the pumping unit has not been solved. In terms of the improvement of the driving force of the pumping unit, the author, based on the currently prevailing linear motor control equipment, carries out the improvement for the conventional traveling beam balance pumping unit, replacing the previous rotary motor control equipment with the linear motor control equipment to improve the overall efficiency contradiction problem of the old traditional type of pumping unit.
基金supported by the National Natural Science Foundation of China (Nos. 61271153, 61372039)
文摘In the face of harsh natural environment applications such as earth-orbiting and deep space satellites, underwater sea vehicles, strong electromagnetic interference and temperature stress,the circuits faults appear easily. Circuit faults will inevitably lead to serious losses of availability or impeded mission success without self-repair over the mission duration. Traditional fault-repair methods based on redundant fault-tolerant technique are straightforward to implement, yet their area, power and weight cost can be excessive. Moreover they utilize all plug-in or component level circuits to realize redundant backup, such that their applicability is limited. Hence, a novel selfrepair technology based on evolvable hardware（EHW） and reparation balance technology（RBT） is proposed. Its cost is low, and fault self-repair of various circuits and devices can be realized through dynamic configuration. Making full use of the fault signals, correcting circuit can be found through EHW technique to realize the balance and compensation of the fault output-signals. In this paper, the self-repair model was analyzed which based on EHW and RBT technique, the specific self-repair strategy was studied, the corresponding self-repair circuit fault system was designed, and the typical faults were simulated and analyzed which combined with the actual electronic devices. Simulation results demonstrated that the proposed fault self-repair strategy was feasible. Compared to traditional techniques, fault self-repair based on EHW consumes fewer hardware resources, and the scope of fault self-repair was expanded significantly.
基金The financial support from the Australian Government as Part of the Asia-Pacific Partnership on Clean Development and Climate,and the National Natural Science Foundation of China (Nos. 51074156 and 51274196)
文摘Sampling ports were firstly drilled on a ZGM95 coal mill in the power plant in China, and the coal samples from various points in the pulverizer were collected under the different operation conditions. The prop- erty of the sampling material from the mill was analyzed, applying the float-sink test, size distribution analysis, proximate analysis and so on. It was indicated that the ＋250 I^m fraction in the pulverized fuel accounted for only 0.02%, while it was 83.2% in the new feed. The circulating ratio and coal flow in the separator and the cone zone were calculated using the mass balance of the circulating load. So, the cir- culating ratio in the separator of the pulverizer was between 8 and 13, and the circulating ratio, the feed flow of separator and cone zone all raised with the increase of the air volume. Furthermore, the parameters of the separation functions were obtained based on the fitting method. It was shown that the mean value of the shape factor B was 0.7617, and the parameter D which is the particle size at 50% cumulative yield in the separator almost kept unchanged.
基金Supported by Shanghai Municipal Science and Technology Commission(Grant No.12JC1408700)National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant Nos.2013ZX04012-071,2011ZX04015-022)
文摘Line configuration and balancing is to select the type of line and allot a given set of operations as well as machines to a sequence of workstations to realize high-efficiency production. Most of the current researches for machining line configuration and balancing problems are related to dedicated transfer lines with dedicated machine workstations. With growing trends towards great product variety and fluctuations in market demand, dedicated transfer lines are being replaced with flexible machining line composed of identical CNC machines. This paper deals with the line configuration and balancing problem for flexible machining lines. The objective is to assign operations to workstations and find the sequence of execution, specify the number of machines in each workstation while minimizing the line cycle time and total number of machines. This problem is subject to precedence, clustering, accessibility and capacity constraints among the features, operations, setups and workstations. The mathematical model and heuristic algorithm based on feature group strategy and polychromatic sets theory are presented to find an optimal solution. The feature group strategy and polychromatic sets theory are used to establish constraint model. A heuristic operations sequencing and assignment algorithm is given. An industrial case study is carried out, and multiple optimal solutions in different line configurations are obtained. The case studying results show that the solutions with shorter cycle time and higher line balancing rate demonstrate the feasibility and effectiveness of the proposed algorithm. This research proposes a heuristic line configuration and balancing algorithm based on feature group strategy and polychromatic sets theory which is able to provide better solutions while achieving an improvement in computing time.
基金National Natural Science Foundation of China(NSFC)“Theory and Technology of Complex Seam Network in High Temperature Rock for Storage”(No.52192621)National Key Research and Development Program(No.2018YFB1501804)+2 种基金Sichuan Science and Technology Program Project“Research on the Mechanism of Enhanced Heat Transfer between Geothermal Well Completion Structure and Downhole Heat Exchanger”(No.2021Ya1.389)National Key Research and Development Program(No.2021YJ0389)“Research on the Mechanism of Fracture Damage in Dry Hot Rock Extraction”(PRP/open-2110)of the State Key Laboratory of Oil and Gas Resources and Exploration,China University of Petroleum(Beijing).
文摘Geothermal energy,a kind of clean and environmentally friendly energy source,is an important object of future natural resource development and utilization,among which,hot dry rock is one of the important deep geothermal resources.In the current multi-objective optimization of heat extraction performance,reservoir production models are less considered and the effects of different optimization ideas are not compared comprehensively.To improve the heat extraction efficiency and prolong the exploitation life of geothermal reservoirs,this paper determines the appropriate operating parameters of geothermal system(injection temperature,injection rate,production pressure and injection-production well spacing)based on the coupled thermal-hydraulic-mechanical model of hot dry rock exploitation in the Gonghe area of Qinghai and three heat extraction optimization methods.In addition,the heat extraction performances of different schemes are comparatively evaluated.And the following research results are obtained.First,the sensitivity analysis of injection and production parameters shows that power generation and recovery factor are in a reverse relation with injection-production pressure difference,which is the direct reason for the adoption of multiobjective optimization.Second,the optimization scheme prepared on the basis of parametric study indicates that the shortest life of a geothermal reservoir is 10 years,the injection-production pressure difference is up to 67 MPa,there is a significant thermal breakthrough phenomenon and the reservoir safety faces challenges.Third,by virtue of multi-objective optimization and decision making integration,the optimal operation parameter combination of hot dry rock system is determined,the life of geothermal reservoirs can exceed 20 years and balanced optimization is achieved.In conclusion,the idea of multi-objective optimization is feasible and applicable to geothermal energy exploitation and this method provides a reference for the efficient geothermal energy development and utilization and is helpful to the realization of“double carbon”goal in China.
基金supported by Shandong Provincial Natural Science Foundation of China(Grant No.ZR2010EL003)
文摘The working platforms supported with multiple extensible legs must be leveled before they come into operation.Although the supporting stiffness and reliability of the platform are improved with the increasing number of the supporting legs,the increased overdetermination of the multi-leg platform systems leads to leveling coupling problem among legs and virtual leg problem in which some of the supporting legs bear zero or quasi zero loads.These problems make it quite complex and time consuming to level such a multi-leg platform.Based on rigid body kinematics,an approximate equation is formulated to rapidly calculate the leg extension for leveling a rigid platform,then a proportional speed control strategy is proposed to reduce the unexpected platform distortion and leveling coupling between supporting legs.Taking both the load coupling between supporting legs and the elastic flexibility of the working platform into consideration,an optimal balancing legs’ loads(OBLL) model is firstly put forward to deal with the traditional virtual leg problem.By taking advantage of the concept of supporting stiffness matrix,a coupling extension method(CEM) is developed to solve this OBLL problem for multi-leg flexible platform.At the end,with the concept of supporting stiffness matrix and static transmissibility matrix,an optimal load balancing leveling method is proposed to achieve geometric leveling and legs’ loads balancing simultaneously.Three numerical examples are given out to illustrate the performance of proposed methods.This paper proposes a method which can effectively quantify all of the legs’ extension at the same time,achieve geometric leveling and legs’ loads balancing simultaneously.By using the proposed methods,the stability,precision and efficiency of auto-leveling control process can be improved.
基金The National Natural Science Foundation of China(No.61273236)the National Key Research and Development Plan of China(No.2016YFC0802706,2017YFC0804804)+1 种基金the Program for Special Talents in Six Major Fields of Jiangsu Province(No.2017JXQC-003)the Project of Beijing Municipal Science and Technology Commission(No.Z161100001416001)
文摘In order to realize an optimal balance between the efficiency and reliability requirements ofroad models,a road modeling method for digital maps based on cardinal spline is studied.First,the cardinal spline is chosen to establish an initial road model,which is specified by a series of control points and tension parameters.Then,in view of the initial road model,a gradual optimization algorithm,which can determine the reasonable control points and optimal tension parameters according to the degree of the change of road curvature,is proposed to determine the final road model.Finally,the proposed road modeling method is verified a d evaluated through experiments,and it is compared with the conventional method for digital maps based on the B-spline.The results show that the proposed method can resize a neaoptimal balance between the efficiency and reliability requirements.Compared with the conventional method based on the B-spline,this method occupies less data storage and achieves higher accuracy.
文摘Reconfigurable products and manufacturing systems have enabled manufacturers to provide ＂cost effective＂ variety to the market. In spite of these new technologies, the expense of manufacturing makes it infeasible to supply all the possible variants to the market for some industries. Therefore, the determination of the right number of product variantsto offer in the product portfolios becomes an important consideration. The product portfolio planning problem had been independently well studied from marketing and engineering perspectives. However, advantages can be gained from using a concurrent marketing and engineering approach. Concurrent product development strategies specifically for reconfigurable products and manufacturing systems can allow manufacturers to select best product portfolios from marketing, product design and manufacturing perspectives. A methodology for the concurrent design of a product portfolio and assembly system is presented. The objective of the concurrent product portfolio planning and assembly system design problem is to obtain the product variants that will make up the product portfolio such that oversupply of optional modules is minimized and the assembly line efficiency is maximized. Explicit design of the assembly system is obtained during the solution of the problem. It is assumed that the demand for optional modules and the assembly times for these modules are known a priori. A genetic algorithm is used in the solution of the problem. The basic premise of this methodology is that the selected product portfolio has a significant impact on the solution of the assembly line balancing problem. An example is used to validate this hypothesis. The example is then further developed to demonstrate how the methodology can be used to obtain the optimal product portfolio. This approach is intended for use by manufacturers during the early design stages of product family design.
基金funded by Hanoi University of Science and Technology,Vietnam(No.T2023-PC-013).
文摘This article presents an improved Elman neural network for reducing building vibrations during earthquakes.The adjustment coefficient is proposed to be added to the Elman network’s output layer to improve the controller’s performance when used to minimize vibrations in buildings.The parameters of the proposed Elman neural network model are optimized using the Balancing Composite Motion Optimization algorithm.The effectiveness of the proposed method is assessed using a three-story structure with an active dampening mechanism on the first level.The study also takes into account two kinds of Elman neural network input variables:displacement and velocity data on the first floor,as well as displacement and velocity readings across all three floors.This research uses two measures of fitness functions in the optimal process,the structure’s peak displacement and acceleration,to determine the best parameters for the proposed model.The effectiveness of the proposed method is demonstrated in restraining the vibration of the structure under a variety of earthquakes.Furthermore,the findings indicate that the proposed model maintains sustainability even when the maximum value of the actuator device is dropped.
基金The National Natural Science Foundation of China(62105126,62120106001,and 62205227)the Natural Science Foundation of Jiangsu Province(BK20210454),the China Postdoctoral Science Foundation(2023M731449)+3 种基金the Undergraduate Training Program for Innovation and Entrepreneurship,Soochow University(202310285116Y)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(22KJB140005)the Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province,Soochow University(ZZ2311)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.
文摘Circularly polarized light(CPL)detectors based on chiral organic materials or inorganic structures hold great potential for highly integrated on-chip applications;however,these devices usually have to seek an optimal balance among the asymmetry factor(g),responsivity(R),and stability.Here,we aim to break such a limitation by combining chiral inorganic plasmonic metamaterials with electrical gain,by which one can enhance both g and R while simultaneously securing the stability.We demonstrate a CPL detector based on"S"-shaped chiral Ag nanowires/InAs/Si heterostructures,where the meticulous construction of the"S"-shaped chiral Ag nanowires with the overlaying InAs channel enables a substantial absorption asymmetry in InAs due to differentiated localized surface plasmon resonances excited by left-and right-circularly polarized(LCP and RCP)light.The InAs serves as a conductive channel,achieving significant electrical gain through photoconductive effects assisted by photogating,gate modulation,and trap effects.The proposed inorganic stable device exhibits a high electrical g of~1.56,an ultra-high R of~33,900 A W^(-1),a large specific detectivity of~1.8×10^(11) Jones,and an ultra-short response time of~23 ns,with the high performance achieved in a broad spectral range from 2μm to 2.8μm.Ultimately,by encoding ASCII code 1 and 0 onto LCP and RCP light,respectively,and leveraging the device's heightened discrimination and response performance to these polarizations,we demonstrate a simple yet key-free optical encryption communication scheme at the device level,highlighting its extensive potential for system-level applications.
