期刊文献+
共找到7,830篇文章
< 1 2 250 >
每页显示 20 50 100
Back analysis of rock mass parameters in mechanized twin tunnels based on coupled auto machine learning and multi-objective optimization algorithm
1
作者 Chengwen Wang Xiaoli Liu +4 位作者 Jiubao Li Enzhi Wang Nan Hu Wenli Yao Zhihui He 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第11期7038-7055,共18页
Accurate determination of rock mass parameters is essential for ensuring the accuracy of numericalsimulations. Displacement back-analysis is the most widely used method;however, the reliability of thecurrent approache... Accurate determination of rock mass parameters is essential for ensuring the accuracy of numericalsimulations. Displacement back-analysis is the most widely used method;however, the reliability of thecurrent approaches remains unsatisfactory. Therefore, in this paper, a multistage rock mass parameterback-analysis method, that considers the construction process and displacement losses is proposed andimplemented through the coupling of numerical simulation, auto-machine learning (AutoML), andmulti-objective optimization algorithms (MOOAs). First, a parametric modeling platform for mechanizedtwin tunnels is developed, generating a dataset through extensive numerical simulations. Next, theAutoML method is utilized to establish a surrogate model linking rock parameters and displacements.The tunnel construction process is divided into multiple stages, transforming the rock mass parameterback-analysis into a multi-objective optimization problem, for which multi-objective optimization algorithmsare introduced to obtain the rock mass parameters. The newly proposed rock mass parameterback-analysis method is validated in a mechanized twin tunnel project, and its accuracy and effectivenessare demonstrated. Compared with traditional single-stage back-analysis methods, the proposedmodel decreases the average absolute percentage error from 12.73% to 4.34%, significantly improving theaccuracy of the back-analysis. Moreover, although the accuracy of back analysis significantly increaseswith the number of construction stages considered, the back analysis time is acceptable. This studyprovides a new method for displacement back analysis that is efficient and accurate, thereby paving theway for precise parameter determination in numerical simulations. 展开更多
关键词 Back analysis of rock parameters Auto machine learning multi-objective optimization algorithm Mechanized twin tunnels Parametric modeling
在线阅读 下载PDF
A modified back analysis method for deep excavation with multi-objective optimization procedure
2
作者 Chenyang Zhao Le Chen +2 位作者 Pengpeng Ni Wenjun Xia Bin Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第4期1373-1387,共15页
Real-time prediction of excavation-induced displacement of retaining pile during the deep excavation process is crucial for construction safety.This paper proposes a modified back analysis method with multi-objective ... Real-time prediction of excavation-induced displacement of retaining pile during the deep excavation process is crucial for construction safety.This paper proposes a modified back analysis method with multi-objective optimization procedure,which enables a real-time prediction of horizontal displacement of retaining pile during construction.As opposed to the traditional stage-by-stage back analysis,time series monitoring data till the current excavation stage are utilized to form a multi-objective function.Then,the multi-objective particle swarm optimization (MOPSO) algorithm is applied for parameter identification.The optimized model parameters are immediately adopted to predict the excavation-induced pile deformation in the continuous construction stages.To achieve efficient parameter optimization and real-time prediction of system behavior,the back propagation neural network (BPNN) is established to substitute the finite element model,which is further implemented together with MOPSO for automatic operation.The proposed approach is applied in the Taihu tunnel excavation project,where the effectiveness of the method is demonstrated via the comparisons with the site monitoring data.The method is reliable with a prediction accuracy of more than 90%.Moreover,different optimization algorithms,including non-dominated sorting genetic algorithm (NSGA-II),Pareto Envelope-based Selection Algorithm II (PESA-II) and MOPSO,are compared,and their influences on the prediction accuracy at different excavation stages are studied.The results show that MOPSO has the best performance for high dimensional optimization task. 展开更多
关键词 multi-objective optimization Back analysis Surrogate model multi-objective particle swarm optimization(MOPSO) Deep excavation
在线阅读 下载PDF
Ultra-simplified design and quantitative analysis for the optical system of compact laser-induced breakdown spectroscopy
3
作者 Jiujiang YAN Ke LIU +3 位作者 Jinxiu MA Yang LI Kailong LI Hongwei WEI 《Plasma Science and Technology》 2025年第3期87-93,共7页
Optimization and simplification of optical systems represent a milestone in advancing the development of handheld and portable laser-induced breakdown spectroscopy(LIBS)systems towards smaller,more integrated forms.Th... Optimization and simplification of optical systems represent a milestone in advancing the development of handheld and portable laser-induced breakdown spectroscopy(LIBS)systems towards smaller,more integrated forms.This research,for the first time,conducted a comprehensive optimization design and comparative analysis of three compact LIBS system optical paths:the paraxial optical path(OP),the off-axis OP,and the reflective OP.The differences in spectral intensity and stability among these paths were revealed,providing a scientific basis for selecting the optimal OP for LIBS systems.The research found that the paraxial OP excels in spectral performance and quantitative analysis accuracy,making it the preferred choice for compact LIBS systems.Specifically,the paraxial OP significantly enhances spectral intensity,achieving a 6 times improvement over the off-axis OP and an even more remarkable 150 times increase compared to the reflective OP,greatly enhancing detection sensitivity.Additionally,the relative standard deviation,spectral stability index,maintains a consistently low level,ranging from 10.9%to 13.4%,significantly outperforming the other two OPs and ensuring the reliability of analytical results.In the field of quantitative analysis,the paraxial OP also demonstrates higher accuracy,precision,and sensitivity,comparing to other OPs.The quantitative analysis models for Si,Cu,and Ti elements exhibit excellent fitting,providing users with high-quality quantitative analysis results that are of great significance for applications in material science,environmental monitoring,industrial inspection,and other fields.In summary,this study not only confirms the enormous application potential of the paraxial OP in compact LIBS systems but also provides valuable practical experience and theoretical support for the miniaturization and integration of LIBS systems.Looking ahead,with continuous technological advancements,the design of the paraxial OP is expected to further propel the widespread adoption of LIBS technology in portable,on-site detection applications. 展开更多
关键词 compact LIBS optical path design spectral stability quantitative analysis
在线阅读 下载PDF
Multi-Objective Loosely Synchronized Search for Multi-Objective Multi-Agent Path Finding with Asynchronous Actions
4
作者 DU Haikuo GUO Zhengyu +1 位作者 ZHANG Lulu CAI Yunze 《Journal of Shanghai Jiaotong university(Science)》 EI 2024年第4期667-677,共11页
In recent years,the path planning for multi-agent technology has gradually matured,and has made breakthrough progress.The main difficulties in path planning for multi-agent are large state space,long algorithm running... In recent years,the path planning for multi-agent technology has gradually matured,and has made breakthrough progress.The main difficulties in path planning for multi-agent are large state space,long algorithm running time,multiple optimization objectives,and asynchronous action of multiple agents.To solve the above problems,this paper first introduces the main problem of the research:multi-objective multi-agent path finding with asynchronous action,and proposes the algorithm framework of multi-objective loose synchronous(MO-LS)search.By combining A*and M*,MO-LS-A*and MO-LS-M*algorithms are respectively proposed.The completeness and optimality of the algorithm are proved,and a series of comparative experiments are designed to analyze the factors affecting the performance of the algorithm,verifying that the proposed MO-LS-M*algorithm has certain advantages. 展开更多
关键词 multi-agent path finding multi-objective path planning asynchronous action loosely synchronous search
原文传递
Correlation and Pathway Analysis of the Carbon,Nitrogen,and Phosphorus in Soil-Microorganism-Plant with Main Quality Components of Tea(Camellia sinensis)
5
作者 Chun Mao Ji He +3 位作者 Xuefeng Wen Yangzhou Xiang Jihong Feng Yingge Shu 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第3期487-502,共16页
The contents of carbon(C),nitrogen(N),and phosphorus(P)in soil-microorganisms-plant significantly affect tea quality by altering the main quality components of tea,such as tea polyphenols,amino acids,and caffeine.Howev... The contents of carbon(C),nitrogen(N),and phosphorus(P)in soil-microorganisms-plant significantly affect tea quality by altering the main quality components of tea,such as tea polyphenols,amino acids,and caffeine.However,few studies have quantified the effects of these factors on the main quality components of tea.The study aimed to explore the interactions of C,N,and P in soil-microorganisms-plants and the effects of these factors on the main quality components of tea by using the path analysis method.The results indicated that(1)The contents of C,N,and P in soil,microorganisms,and tea plants were highly correlated and collinear,and showed significant correlations with the main quality components of tea.(2)Optimal regression equations were established to esti-mate tea polyphenol,amino acid,catechin,caffeine,and water extract content based on C,N,and P contents in soil,microorganisms,and tea plants(R^(2)=0.923,0.726,0.954,0.848,and 0.883,respectively).(3)Pathway analysis showed that microbial biomass phosphorus(MBP),root phosphorus,branch nitrogen,and microbial biomass carbon(MBC)were the largest direct impact factors on tea polyphenol,catechin,water extracts,amino acid,and caffeine content,respectively.Leaf carbon,root phosphorus,and leaf nitrogen were the largest indirect impact factors on tea polyphenol,catechin,and water extract content,respectively.Leaf carbon indirectly affected tea polyphenol content mainly by altering MBP content.Root phosphorus indirectly affected catechin content mainly by altering soil organic carbon content.Leaf nitrogen indirectly affected water extract content mainly by altering branch nitrogen content.The research results provide the scientific basis for reasonable fertilization in tea gardens and tea quality improvement. 展开更多
关键词 Soil-microorganisms-plant system CARBON NITROGEN PHOSPHORUS tea quality path analysis
在线阅读 下载PDF
Path Analysis of High-Quality Development of Regional Economy The Role and Impact of Industrial Policies
6
作者 Nan Zhou 《Proceedings of Business and Economic Studies》 2024年第2期198-204,共7页
With China’s economic development entering a new normal,high-quality regional economic development has become an important goal of current economic development.As one of the important means to promote high-quality de... With China’s economic development entering a new normal,high-quality regional economic development has become an important goal of current economic development.As one of the important means to promote high-quality development of the regional economy,industrial policies are increasingly receiving attention in terms of their role and impact.This article mainly conducts an in-depth analysis of the mechanism and impact path of industrial policies,exploring the role and impact of industrial policies in promoting high-quality regional economic development.Firstly,industrial policies play an important role in promoting high-quality regional economic development.Secondly,the impact path of industrial policies on the high-quality development of the regional economy mainly includes promoting industrial structure upgrading,promoting technological innovation,guiding resource allocation,and enhancing enterprise competitiveness.Therefore,it is necessary to increase research and practice on industrial policies,continuously optimize policy measures,and promote high-quality development of the regional economy. 展开更多
关键词 Industrial policy Regional economy High-quality development path analysis
在线阅读 下载PDF
Feasibility and Path Analysis of Integrating Innovation and Entrepreneurship Education into“One-Stop”Student Communities
7
作者 Yuming Zhang 《Journal of Contemporary Educational Research》 2024年第5期200-206,共7页
The“one-stop”student community provides new support for innovation and entrepreneurship education in universities.Integrating innovation and entrepreneurship education into the“one-stop”student community work enri... The“one-stop”student community provides new support for innovation and entrepreneurship education in universities.Integrating innovation and entrepreneurship education into the“one-stop”student community work enriches course materials,integrates teacher resources,improves students’participation in innovation and entrepreneurship,and solves problems such as low student participation,lack of course resources,insufficient teacher resources,and single evaluation methods in traditional classrooms.Through various means such as exploring course resources,innovating management models,and strengthening team construction,the role of“one-stop”student communities in innovation and entrepreneurship education has been fully utilized,promoting the development of innovation and entrepreneurship education. 展开更多
关键词 Innovation and entrepreneurship “One-stop”student community FEASIBILITY path analysis
在线阅读 下载PDF
Thermal–structure coupling analysis and multi-objective optimization of motor rotor in MSPMSM 被引量:6
8
作者 Luxin ZHAI Jinji SUN +2 位作者 Xin MA Weitao HAN Xiaosan LUO 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2019年第7期1733-1747,共15页
With the high speed, the rotor of magnetically suspended permanent magnet synchronous motor(MSPMSM) suffers great thermal stress and mechanical stress resulting from the temperature rise problem caused by rotor losses... With the high speed, the rotor of magnetically suspended permanent magnet synchronous motor(MSPMSM) suffers great thermal stress and mechanical stress resulting from the temperature rise problem caused by rotor losses, which leads to instability and inefficiency.In this paper, the mechanical–temperature field coupling analysis is conducted to analyze the relationship between the temperature field and structure, and multi-objective optimization of a rotor is performed to improve the design reliability and efficiency. Firstly, the temperature field is calculated by the 2 D finite element model of MSPMSM and the method of applying the 2 D temperature result to the 3 D finite element model of the motor rotor equivalently is proposed. Then the thermal–structure coupling analysis is processed through mathematic method and finite element method(FEM),in which the 3 D finite element model is established precisely in a way and approaches the practical operation state further. Moreover, the impact produced by the temperature and structure on the mechanical strength is analyzed in detail. Finally, the optimization mathematical model of the motor rotor is established with Sequential Quadratic Programming-NLPQL selected in the optimization scheme. Through optimization, the strength of the components in the motor rotor increases obviously and satisfies the design requirement, which to a great extend enhances the service life of the MSPMSM rotor. 展开更多
关键词 FEM MSPMSM multi-objective optimization THERMAL STRESS Thermal–structure COUPLING analysis
原文传递
Aerodynamic multi-objective integrated optimization based on principal component analysis 被引量:13
9
作者 Jiangtao HUANG Zhu ZHOU +2 位作者 Zhenghong GAO Miao ZHANG Lei YU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2017年第4期1336-1348,共13页
Based on improved multi-objective particle swarm optimization(MOPSO) algorithm with principal component analysis(PCA) methodology, an efficient high-dimension multiobjective optimization method is proposed, which,... Based on improved multi-objective particle swarm optimization(MOPSO) algorithm with principal component analysis(PCA) methodology, an efficient high-dimension multiobjective optimization method is proposed, which, as the purpose of this paper, aims to improve the convergence of Pareto front in multi-objective optimization design. The mathematical efficiency,the physical reasonableness and the reliability in dealing with redundant objectives of PCA are verified by typical DTLZ5 test function and multi-objective correlation analysis of supercritical airfoil,and the proposed method is integrated into aircraft multi-disciplinary design(AMDEsign) platform, which contains aerodynamics, stealth and structure weight analysis and optimization module.Then the proposed method is used for the multi-point integrated aerodynamic optimization of a wide-body passenger aircraft, in which the redundant objectives identified by PCA are transformed to optimization constraints, and several design methods are compared. The design results illustrate that the strategy used in this paper is sufficient and multi-point design requirements of the passenger aircraft are reached. The visualization level of non-dominant Pareto set is improved by effectively reducing the dimension without losing the primary feature of the problem. 展开更多
关键词 Aerodynamic optimization Dimensional reduction Improved multi-objective particle swarm optimization(MOPSO) algorithm multi-objective Principal component analysis
原文传递
Modal Analysis and Multi-objective Optimization of Pressurizing Pipeline 被引量:2
10
作者 WANG Yeping LI Hang 《Journal of Donghua University(English Edition)》 EI CAS 2020年第1期43-49,共7页
The pressurizing pipeline of hot press resonates under the excitation load,which poses a serious hidden danger to the safety of the equipment and the operator.In order to increase the natural frequency of the pressuri... The pressurizing pipeline of hot press resonates under the excitation load,which poses a serious hidden danger to the safety of the equipment and the operator.In order to increase the natural frequency of the pressurizing pipeline,modal analysis of the pressurizing pipeline is carried out to study the mechanism of pipeline vibration and common vibration reduction measures.A method of increasing the natural frequency of the pressurizing pipeline was analyzed.The influence of pipeline clamp assembly stiffness,pipeline clamp number and pipeline clamp installation position on the mode of the pressurizing pipeline is studied.Sensitivity analysis is carried out to study the influence of the various parameters on the mode of the pressurizing pipeline.Genetic algorithm based on Pareto optimality is introduced for multi-objective optimization of pressurizing pipeline.The optimization results show that the natural frequency of the pressurizing pipeline increases by 2.4%and the displacement response is reduced by 17.7%. 展开更多
关键词 pressurizing PIPELINE MODAL analysis sensitivity analysis PARETO OPTIMALITY genetic algorithm multi-objective optimization
在线阅读 下载PDF
Analysis of Energy Storage Operation Configuration of Power System Based on Multi-Objective Optimization 被引量:1
11
作者 Linyao Zhou Tengfei Ma 《Journal of Electronic Research and Application》 2022年第4期13-37,共25页
Driven by the goal of“carbon neutrality,”the increase in use of renewable energy power systems will be inevitable in the future.Uncontrolled output power and random volatility make it difficult to balance power in r... Driven by the goal of“carbon neutrality,”the increase in use of renewable energy power systems will be inevitable in the future.Uncontrolled output power and random volatility make it difficult to balance power in real time during system operation.Therefore,energy storage is considered to be an effective way to ensure the real-time balance of system power.However,cost of energy storage is relatively expensive.As a solution,energy storage can be used to balance the system power in order to reduce system operating costs.Taking the high proportion of wind power systems as an example,the impact of the“supply side”low-carbon transformation on the economics and reliability of power system operation is explored.In order to solve the problem of power system operation configuration optimization under the background of“carbon neutrality,”this paper establishes a multi-objective programming model. 展开更多
关键词 multi-objective planning Energy storage analysis Carbon-neutral Carbon neutrality multi-objective programming model
在线阅读 下载PDF
Optimizing the thermal energy storage performance of shallow aquifers based on gray correlation analysis and multi-objective optimization
12
作者 Yu Shi Qiliang Cui +3 位作者 Zijiang Yang Xianzhi Song Qing Liu Tianyi Lin 《Natural Gas Industry B》 2023年第5期476-489,共14页
The operation parameters and well layout parameters of aquifer thermal energy storage(ATES)system directly influence the thermal energy storage performance.How to optimize the parameters to obtain the optimal process ... The operation parameters and well layout parameters of aquifer thermal energy storage(ATES)system directly influence the thermal energy storage performance.How to optimize the parameters to obtain the optimal process scheme is of great significance to promote thefield application of ATES.Taking the thermal storage performance of shallow aquifer as the optimization objective,this paper compares the influence degrees of key factors on thermal storage performance by means of gray correlation analysis(GCA),and prepares the optimal thermal storage scheme by using the multi-objective optimization method.The following results are obtained.First,the great difference between inlet temperature and aquifer weakens the thermal storage capacity of the system,while the thermal interference between thermal storage wells of the same type is favorable for thermal storage capacity instead.Second,aquifer thickness and well number have a greater impact on the thermal loss rate,while injection rate and well spacing have a significant influence on the thermal recoveryrate.The inlet temperature has the least effect on both of them.Third,the optimal thermal storage scheme is the single well system with inlet temperature of 25 ℃,aquifer thickness of 106.597 m and injection rate of 30 kg/s.In conclusion,the influence degrees of the key parameters on thermal loss rate and thermal recovery rate are different,so in order to improve the thermal storage performance,equilibrium optimization is necessary between both of them.In addition,the optimization scheme effectively expands the thermal storagevolume,and reduces the heat loss while improving the thermal recovery,with thermal loss rate and thermal recovery rate of the whole system optimized by 12.69%and 3.19%respectively on the basic case,which can provide a reference for the rational design of ATES system. 展开更多
关键词 Geothermal energy Aquifer thermal energy storage(ATES) Numerical simulation Gray correlation analysis multi-objective optimization Thermal recovery rate Thermal loss rate Parameter sensitivity analysis
在线阅读 下载PDF
Correlation and path coefficient analysis for phenotypic traits of noble scallop Chlamys nobilis 被引量:2
13
作者 李俊辉 杜晓东 +1 位作者 邓岳文 王庆恒 《Marine Science Bulletin》 CAS 2010年第2期55-60,共6页
In April of 2006, a base population of the noble scallop Chlamys nobilis was established by collecting parental breeders from the stocks in Wushi, Zhanjiang. In December of 2006, 200 individuals were randomly sampled ... In April of 2006, a base population of the noble scallop Chlamys nobilis was established by collecting parental breeders from the stocks in Wushi, Zhanjiang. In December of 2006, 200 individuals were randomly sampled from the base population and subjected for correlation and path coefficient analysis. It was found that there were statistically significant phenotypic correlations among the traits (P 〈 0.01). Total weight was significantly and positively correlated with the shell length (r = 0.934 3), shell height (r = 0.895 9), shell width (r = 0.899 1 ), muscle weight (r = 0.882 0) and shell weight (r = 0.937 9), respectively. Shell length, shell width, muscle weight, shell height and shell weight had positive and direct effects on the total weight, with values of 0.397 1, 0.321 9, 0.172 1, 0.089 6 and 0.066 9, respectively. Shell length, shell width and muscle weight had higher direct effects on the total weight than shell height and shell weight. A combined evaluation of correlation, direct effects and indirect effects showed that direct selection for shell length, shell width, muscle weight, shell height and shell weight would be effective to improving the total weight. It was concluded that these traits could be regarded as the selection criteria in breeding programs of the species. 展开更多
关键词 Chlamys nobilis phenotypic traits CORRELATION path coefficient analysis
在线阅读 下载PDF
Correlation Analysis and Path Analysis between Yield and Yield-Related Traits of Yunmai 52 被引量:1
14
作者 赵红 刘琨 +7 位作者 李宏生 崔永祯 田玉仙 顾坚 李绍祥 杨木军 浦秋红 丁明亮 《Agricultural Science & Technology》 CAS 2017年第3期407-410,431,共5页
[Objective] This study was tween yield-related traits and yield of conducted to understand the relationship be- Yunmai 52 which is a high-quality high-yield multi-resistant new wheat variety, and make contribution of ... [Objective] This study was tween yield-related traits and yield of conducted to understand the relationship be- Yunmai 52 which is a high-quality high-yield multi-resistant new wheat variety, and make contribution of yield-related traits to the yield of Yunmai 52 clear. [Method] Wheat variety regional trial data in Yunnan Province in 2005-2007 were subjected to correlation analysis and path analysis in the paper. [Result] Correlationanalysis showed that the yield of Yunmai 52 was in- very significant positive correlation with spikelet number per ear, maximum tiller number and grains per ear (r=0.726^**, 0.717^** and 0.695^**, respectively), in signif- icant positive correlation with 1 000-grain weight (r=0.491^*), but in significant nega- tive correlation with sterile spikelet number per ear, and in non-significant correlation with basic seedlings, effective ears and percentage of ear bearing tillers. Partial correlation analysis showed that the yield of Yunmai 52 was in very significant posi- tive correlation with spikelet number per ear (r=0.711^**), significant positive correla- tion with 1 000-grain weight (r=0.641 =), but in non-significant correlation with other 6 traits. Path analysis showed that spikelet number per ear (P=-0.595), maximum tiller number (P=0.462) and t 000-grain weight (P=0.263) had more contribution to yield of Yunmai 52. [Conclusion] Therefore, in extension and application of Yunmal 52 that is a high-quality high-yield multi-resistant new wheat variety, supply of fertilizer and water should be increased in tillering stage and jointing stage, to ensure its characteristics of high tilledng ability and large ear, as well as high 1 000-grain weight, and coordinated development of other yield-related traits is beneficial to im- provement of yield of Yunmai 52. 展开更多
关键词 Yunmai 52 YIELD Yield-related traits Correlation analysis path analysis
在线阅读 下载PDF
Path Analysis on the Meteorological Factors Impacting Soil Respiration Rate of Wheat Field 被引量:2
15
作者 江晓东 李永秀 《Agricultural Science & Technology》 CAS 2009年第1期74-76,156,共4页
[Objective]The experiment aimed to study the effects of meteorological factors under different weather conditions on soil respiration. [ Method] The path analysis was used to analyze meteorological factors which influ... [Objective]The experiment aimed to study the effects of meteorological factors under different weather conditions on soil respiration. [ Method] The path analysis was used to analyze meteorological factors which influenced soil respiration of wheat field under different weather condition and at jointing stage. [ Result] In sunny day, the correlations between ground temperature at 5 cm, solar radiation, air relative humidity, air temperature and soil respiration were all at significant level while solar radiation and ground temperature at 5 cm were the major factors which influenced soil respiration. In cloudy day, solar radiation was a major factor which influenced soil respiration.[ Conclusion] The soil respiration and surplus path coefficient in sunny day were all higher than these in cloudy day, which demonstrated that except influenced by ground temperature, air temperature, solar radiation and air relative humidity, the soil respiration was also influenced by other factors especially biological factor. 展开更多
关键词 Soil respiration Wheat meteorological factors path analysis
在线阅读 下载PDF
Multi-Robot Task Allocation Using Multimodal Multi-Objective Evolutionary Algorithm Based on Deep Reinforcement Learning 被引量:4
16
作者 苗镇华 黄文焘 +1 位作者 张依恋 范勤勤 《Journal of Shanghai Jiaotong university(Science)》 EI 2024年第3期377-387,共11页
The overall performance of multi-robot collaborative systems is significantly affected by the multi-robot task allocation.To improve the effectiveness,robustness,and safety of multi-robot collaborative systems,a multi... The overall performance of multi-robot collaborative systems is significantly affected by the multi-robot task allocation.To improve the effectiveness,robustness,and safety of multi-robot collaborative systems,a multimodal multi-objective evolutionary algorithm based on deep reinforcement learning is proposed in this paper.The improved multimodal multi-objective evolutionary algorithm is used to solve multi-robot task allo-cation problems.Moreover,a deep reinforcement learning strategy is used in the last generation to provide a high-quality path for each assigned robot via an end-to-end manner.Comparisons with three popular multimodal multi-objective evolutionary algorithms on three different scenarios of multi-robot task allocation problems are carried out to verify the performance of the proposed algorithm.The experimental test results show that the proposed algorithm can generate sufficient equivalent schemes to improve the availability and robustness of multi-robot collaborative systems in uncertain environments,and also produce the best scheme to improve the overall task execution efficiency of multi-robot collaborative systems. 展开更多
关键词 multi-robot task allocation multi-robot cooperation path planning multimodal multi-objective evo-lutionary algorithm deep reinforcement learning
原文传递
Multi-objective optimization and evaluation of supercritical CO_(2) Brayton cycle for nuclear power generation 被引量:4
17
作者 Guo-Peng Yu Yong-Feng Cheng +1 位作者 Na Zhang Ping-Jian Ming 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第2期183-209,共27页
The supercritical CO_(2) Brayton cycle is considered a promising energy conversion system for Generation IV reactors for its simple layout,compact structure,and high cycle efficiency.Mathematical models of four Brayto... The supercritical CO_(2) Brayton cycle is considered a promising energy conversion system for Generation IV reactors for its simple layout,compact structure,and high cycle efficiency.Mathematical models of four Brayton cycle layouts are developed in this study for different reactors to reduce the cost and increase the thermohydraulic performance of nuclear power generation to promote the commercialization of nuclear energy.Parametric analysis,multi-objective optimizations,and four decision-making methods are applied to obtain each Brayton scheme’s optimal thermohydraulic and economic indexes.Results show that for the same design thermal power scale of reactors,the higher the core’s exit temperature,the better the Brayton cycle’s thermo-economic performance.Among the four-cycle layouts,the recompression cycle(RC)has the best overall performance,followed by the simple recuperation cycle(SR)and the intercooling cycle(IC),and the worst is the reheating cycle(RH).However,RH has the lowest total cost of investment(C_(tot))of$1619.85 million,and IC has the lowest levelized cost of energy(LCOE)of 0.012$/(kWh).The nuclear Brayton cycle system’s overall performance has been improved due to optimization.The performance of the molten salt reactor combined with the intercooling cycle(MSR-IC)scheme has the greatest improvement,with the net output power(W_(net)),thermal efficiencyη_(t),and exergy efficiency(η_(e))improved by 8.58%,8.58%,and 11.21%,respectively.The performance of the lead-cooled fast reactor combined with the simple recuperation cycle scheme was optimized to increase C_(tot) by 27.78%.In comparison,the internal rate of return(IRR)increased by only 7.8%,which is not friendly to investors with limited funds.For the nuclear Brayton cycle,the molten salt reactor combined with the recompression cycle scheme should receive priority,and the gas-cooled fast reactor combined with the reheating cycle scheme should be considered carefully. 展开更多
关键词 Supercritical CO_(2)Brayton cycle Nuclear power generation Thermo-economic analysis multi-objective optimization Decision-making methods
在线阅读 下载PDF
Causal Analysis Between Rice Growth and Cadmium Accumulation and Transfer under Arbuscular Mycorrhizal Inoculation 被引量:2
18
作者 ZHAO Ting WANG Li +1 位作者 YANG Jixian MA Fang 《Rice science》 SCIE CSCD 2024年第2期226-236,共11页
Cadmium(Cd)contamination in rice has been a serious threat to human health.To investigate the effects of arbuscular mycorrhizal fungi(AMF)on the Cd translocation in rice,a controlled pot experiment was conducted.The r... Cadmium(Cd)contamination in rice has been a serious threat to human health.To investigate the effects of arbuscular mycorrhizal fungi(AMF)on the Cd translocation in rice,a controlled pot experiment was conducted.The results indicated that AMF significantly increased rice biomass,with an increase of up to 40.0%,particularly in root biomass by up to 68.4%.Notably,the number of prominent rice individuals also increased,and their plasticity was enhanced following AMF inoculation.AMF led to an increase in the net photosynthetic rate and antioxidant enzyme activity of rice.In the AMF treatment group,the Cd concentration in the rice roots was significantly higher(19.1%‒68.0%)compared with that in the control group.Conversely,the Cd concentration in the rice seeds was lower in the AMF treatment group,indicating that AMF facilitated the sequestration of Cd in rice roots and reduced Cd accumulation in the seeds.Path coefficients varied across different treatments,suggesting that AMF inoculation reduced the direct impact of soil Cd concentration on the total Cd accumulation in seeds.The translocation of Cd was consistently associated with simultaneous growth dilution and compensatory accumulation as a result of mycorrhizal effects.Our study quantitatively analyzed this process through path analysis and clarified the causal relationship between rice growth and Cd transfer under the influence of AMF. 展开更多
关键词 cadmium transfer dilution effect heavy metal immobilization mycorrhizal effect path analysis phenotypic plasticity
在线阅读 下载PDF
Study of Multi-objective Fuzzy Optimization for Path Planning 被引量:12
19
作者 WANG Yanyang WEI Tietao QU Xiangju 《Chinese Journal of Aeronautics》 SCIE EI CSCD 2012年第1期51-56,共6页
During path planning, it is necessary to satisfy the requirements of multiple objectives. Multi-objective synthesis is based on the need of flight mission and subjectivity inclination of decision-maker. The decision-m... During path planning, it is necessary to satisfy the requirements of multiple objectives. Multi-objective synthesis is based on the need of flight mission and subjectivity inclination of decision-maker. The decision-maker, however, has illegibility for under- standing the requirements of multiple objectives and the subjectivity inclination. It is important to develop a reasonable cost performance index for describing the illegibility of the decision-maker in multi-objective path planning. Based on Voronoi dia- gram method for the path planning, this paper studies the synthesis method of the multi-objective cost performance index. Ac- cording to the application of the cost performance index to the path planning based on Voronoi diagram method, this paper ana- lyzes the cost performance index which has been referred to at present. The analysis shows the insufficiency of the cost per- formance index at present, i.e., it is difficult to synthesize sub-objective flmctions because of the great disparity of the sub-objective fimctions. Thus, a new approach is developed to optimize the cost performance index with the multi-objective fuzzy optimization strategy, and an improved performance index is established, which could coordinate the weight conflict of the sub-objective functions. Finally, the experimental result shows the effectiveness of the proposed approach. 展开更多
关键词 flight paths path planning cost performance index synthesis of multi-objective fuzzy inference Voronoi diagram
原文传递
Impact of climate factors on runoff in the Kaidu River watershed:path analysis of 50-year data 被引量:10
20
作者 XueMei LI LanHai LI +3 位作者 LingPeng GUO FeiYun ZHANG Suwannee ADSAVAKULCHAI Ming SHANG 《Journal of Arid Land》 SCIE 2011年第2期132-140,共9页
Runoff formation is a complex meteorological-hydrological process impacted by many factors,especially in the inland river basin.Based on the data of daily mean air temperature,precipitation and runoff during the perio... Runoff formation is a complex meteorological-hydrological process impacted by many factors,especially in the inland river basin.Based on the data of daily mean air temperature,precipitation and runoff during the period of 1958-2007 in the Kaidu River watershed,this paper analyzed the changes in air temperature,precipitation and runoff and revealed the direct and indirect impacts of daily air temperature and precipitation on daily runoff by path analysis.The results showed that mean temperature time series of the annual,summer and autumn had a significant fluctuant increase during the last 50 years(P 0.05).Only winter precipitation increased significantly(P 0.05) with a rate of 1.337 mm/10a.The annual and winter runoff depthes in the last 50 years significantly increased with the rates of 7.11 mm/10a and 1.85 mm/10a,respectively.The driving function of both daily temperature and precipitation on daily runoff in annual and seasonal levels is significant in the Kaidu River watershed by correlation analysis.The result of path analysis showed that the positive effect of daily air temperature on daily runoff depth is much higher than that of daily precipitation in annual,spring,autumn and winter,however,the trend is opposite in summer. 展开更多
关键词 climate factors runoff formation inland river Kaidu River watershed path analysis
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部