As a new type of marine structure,floating breakwater can provide suitable water area for coastal residents.In this paper,a multi-module floating breakwater with three cylinders was designed.According to the character...As a new type of marine structure,floating breakwater can provide suitable water area for coastal residents.In this paper,a multi-module floating breakwater with three cylinders was designed.According to the characteristics of each module,the elastic connector was created.The cabins with functions such as living,generating electricity and entertainment were arranged.A linear spring constrained design wave(LSCDW)method for strength analysis of floating marine structures with multi-module elastic connections was proposed.The numerical model was verified by 1:50 similarity ratio in the test tank.According to the analysis of design wave and extreme wave conditions,considering the mooring loads and environmental loads and connector loads,the overall strength of breakwater was analyzed by LSCDW method.These studies can provide new insights and theoretical guidance for the design of multi-module floating structures.展开更多
Accurate estimations of grain output in the agriculturally important region of Northeast China are of great strategic significance for guaranteeing food security.New prediction models for maize and rice yields are bui...Accurate estimations of grain output in the agriculturally important region of Northeast China are of great strategic significance for guaranteeing food security.New prediction models for maize and rice yields are built in this paper based on the spring North Atlantic Oscillation index and the Bering Sea ice cover index.The year-to-year increment is first forecasted and then the original yield value is obtained by adding the historical yield of the previous year.The multivariate linear prediction model of maize shows good predictive ability,with a low normalized root-mean-square error（NRMSE）of 13.9%,and the simulated yield accounts for 81%of the total variance of the observation.To improve the performance of the multivariate linear model,a combined forecasting model of rice is built by considering the weight of the predictors.The NRMSE of the model is 12.9%and the predicted rice yield explains 71%of the total variance.The corresponding cross-validation test and independent samples test further demonstrate the efficiency of the models.It is inferred that the statistical models established here by applying year-to-year increment approach could make rational prediction for the maize and rice yield in Northeast China before harvest.The present study may shed new light on yield prediction in advance by use of antecedent large-scale climate signals adequately.展开更多
The sensitivity analysis investigates the effect of particles shape(made by sphere,multi-spheres or polyhedral)for various contact force models on the calibration procedure via ring shear test.Experimental shear tests...The sensitivity analysis investigates the effect of particles shape(made by sphere,multi-spheres or polyhedral)for various contact force models on the calibration procedure via ring shear test.Experimental shear tests were performed using a Schulze Ring Shear Tester RST-01 with spherical and cubic particles.Pre-shear stress and vertical lid position behaviour were observed using Hertz-Mindlin and Linear Spring contact models.The findings confirm the necessity to include not only the shear force but also the compress behaviour of the particles in the shear test calibration.The results clearly indicate that the position of the shear lid provides discrete element method users with an important overview of the fundamental deformation behaviour and particle displacement during the pre-shear process.The results reveal differences between particle and contact force models considering the changes due to increased shear velocity useable for different representation of real-life particulate materials.The research is intended to provide DEM modellers with general information on which parameters are affected by changing the input data for each contact force model and particle shape.These insights enhance calibration procedures in both industrial and academic settings serving as a foundation for not only time optimizing DEM models and improving their accuracy.展开更多
基金the National Natural Science Foundation of China(No.52071161)。
文摘As a new type of marine structure,floating breakwater can provide suitable water area for coastal residents.In this paper,a multi-module floating breakwater with three cylinders was designed.According to the characteristics of each module,the elastic connector was created.The cabins with functions such as living,generating electricity and entertainment were arranged.A linear spring constrained design wave(LSCDW)method for strength analysis of floating marine structures with multi-module elastic connections was proposed.The numerical model was verified by 1:50 similarity ratio in the test tank.According to the analysis of design wave and extreme wave conditions,considering the mooring loads and environmental loads and connector loads,the overall strength of breakwater was analyzed by LSCDW method.These studies can provide new insights and theoretical guidance for the design of multi-module floating structures.
基金Supported by the National Natural Science Foundation of China(41210007 and 41421004)Basic Research and Operation Fund of Chinese Academy of Meteorological Sciences(2016Y007)
文摘Accurate estimations of grain output in the agriculturally important region of Northeast China are of great strategic significance for guaranteeing food security.New prediction models for maize and rice yields are built in this paper based on the spring North Atlantic Oscillation index and the Bering Sea ice cover index.The year-to-year increment is first forecasted and then the original yield value is obtained by adding the historical yield of the previous year.The multivariate linear prediction model of maize shows good predictive ability,with a low normalized root-mean-square error（NRMSE）of 13.9%,and the simulated yield accounts for 81%of the total variance of the observation.To improve the performance of the multivariate linear model,a combined forecasting model of rice is built by considering the weight of the predictors.The NRMSE of the model is 12.9%and the predicted rice yield explains 71%of the total variance.The corresponding cross-validation test and independent samples test further demonstrate the efficiency of the models.It is inferred that the statistical models established here by applying year-to-year increment approach could make rational prediction for the maize and rice yield in Northeast China before harvest.The present study may shed new light on yield prediction in advance by use of antecedent large-scale climate signals adequately.
基金This paper was created as part of the project No.CZ.02.01.01/00/22_008/0004631 Materials and technologies for sustainable development within the Jan Amos Komensky Operational Program financed by the European Union and from the state budget of the Czech Republic,and project The European Just Transition Fund supported this work within the Operational Programme Just Transition under the aegis of the Ministry of the Environment of the Czech Republic,project CirkArena,number CZ.10.03.01/00/22_003/0000045supported by Grant of SGS No.SP2025/005 Development of measuring apparatus for determination of thermodynamic properties of mineral raw materials for design of process and treatment plants,Faculty of Mining and Geology,VSB-Technical University Ostrava,Czech Republic.
文摘The sensitivity analysis investigates the effect of particles shape(made by sphere,multi-spheres or polyhedral)for various contact force models on the calibration procedure via ring shear test.Experimental shear tests were performed using a Schulze Ring Shear Tester RST-01 with spherical and cubic particles.Pre-shear stress and vertical lid position behaviour were observed using Hertz-Mindlin and Linear Spring contact models.The findings confirm the necessity to include not only the shear force but also the compress behaviour of the particles in the shear test calibration.The results clearly indicate that the position of the shear lid provides discrete element method users with an important overview of the fundamental deformation behaviour and particle displacement during the pre-shear process.The results reveal differences between particle and contact force models considering the changes due to increased shear velocity useable for different representation of real-life particulate materials.The research is intended to provide DEM modellers with general information on which parameters are affected by changing the input data for each contact force model and particle shape.These insights enhance calibration procedures in both industrial and academic settings serving as a foundation for not only time optimizing DEM models and improving their accuracy.
