This study applied a multivariate model based on three simulated sensors to estimating water quality variables in Shitoukoumen Reservoir,Changchun City,Jilin Province,China,including concentration of total suspended m...This study applied a multivariate model based on three simulated sensors to estimating water quality variables in Shitoukoumen Reservoir,Changchun City,Jilin Province,China,including concentration of total suspended matter,concentration of chlorophyll-a and non-pigment matter absorption.Two field campaigns for spectra measurements with a total of 40 samples were carried out on June 13 and September 23,2008.The in-situ spectra were recalculated to the spectral bands and sensitivities of the instruments applied in this paper,i.e.Landsat TM,Alos and P6,by using the average method.And the recalculated spectra were used for estimating water quality variables by the single model and multivariate model.The results show that the multivariate model is superior to the single model as the multivariate model takes the combined effects of water components into consideration and can estimate water quality variables simultaneously.According to R2 and RMSE,Alos is superior to other sensors for water quality variables estimation although the precision of non-pigment matter absorption inversion performed the second.展开更多
In this study, we propose a new temperature compensation control strategy for a multi-cavity hot runner injection molding system, At first, the melt filling time of each cavity can be measured by installing temperatur...In this study, we propose a new temperature compensation control strategy for a multi-cavity hot runner injection molding system, At first, the melt filling time of each cavity can be measured by installing temperature sensors on the position around end filling area, and filling time difference between the various cavities can be calculated. Then the melt temperature of each hot nozzle can be adjusted automatically by a control strategy established based on the Fuzzy Theory and a program compiled with LABVIEW software. Temperature changes the melt mobility, so the adjustment of temperature can equalize the filling time of the melt in each cavity, which can reduced the mass deviation between each cavity and make product properties of each cavity consistent. The conclusion of the experiment is as follows： For this contact lens box of a four-cavity Hot Runner mold, by applying hot runner temperature compensation control system, time difference can be reduced from 0.05 s to 0.01 s at each cavity, and the mass Standard deviation of the four cavity can be improved from 0.006 to 0.002. The ratio of imbalance can be reduced from 20% to 4%. Hence, the hot runner temperature compensation control system has significant feasibility and high potential in improving melt flow balance of multi-cavity molding application.展开更多
Impacts of returns on assets are not instantaneously felt, since there is lag period. In this paper we consider the problem of developing a model for the conditional QPDL （quantile polynomial distributed lag） and in...Impacts of returns on assets are not instantaneously felt, since there is lag period. In this paper we consider the problem of developing a model for the conditional QPDL （quantile polynomial distributed lag） and investigate the influences of the conditioning variables on the location, scale and shape parameters of the QPDL model. As an economic application, we consider the production of rubber and its price returns ofSri Lanka. From the analysis we observed that the QPDL model applications were better estimators than the PDL （Polynomial Distributed Lag） models.展开更多
There is one problem existing in gyroscope signal processing,which is that single models can＇ t adapt to change of carrier maneuvering process.Since it is difficult to identify the angular motion state of gyroscope c...There is one problem existing in gyroscope signal processing,which is that single models can＇ t adapt to change of carrier maneuvering process.Since it is difficult to identify the angular motion state of gyroscope carriers,interacting multiple model （IMM） is employed here to solve the problem.The Kalman filter-based IMM （IMMKF） algorithm is explained in detail and its application in gyro signal processing is introduced.And with the help of the Singer model,the system model set of gyro outputs is constructed.In order to demonstrate the effectiveness of the proposed approach,static experiment and dynamic experiment are carried out respectively.Simulation analysis results indicate that the IMMKF algorithm is excellent in eliminating gyro drift errors,which could adapt to the change of carrier maneuvering process well.展开更多
For the further design of the particular gearbox components, the alternating cycles of the respective application mean an often insufficient knowledge of the actual loads occuring in use. Especially for the applicatio...For the further design of the particular gearbox components, the alternating cycles of the respective application mean an often insufficient knowledge of the actual loads occuring in use. Especially for the application within lifting units, such dynamic load cycles are very difficult to pre-estimate. The so-called slack rope test represents the most critical point in the load cycle and provides a special challenge for the gearbox design. Because of this missing expert knowledge, a test bench of such an application is installed and applied to practical movement cycles. Besides the test bench, a multi-body simulation model of the whole system is mapped within the MBS （multi-body simulation） environment SIMPACK. To verify this simulation model, the results are compared with the respective measurements of the test bench. These comparisons show very good agreements. Thus, one of the major advantages of using such simulation tools is the possibility to re-evaluate the internal and external loads during the whole design process. Finally, these simulations serve as a clarification of the load spectrum of the different drivetrain components. Gearbox series or different modifications of the design can now be analyzed prospectively without extensive testing.展开更多
In order to solve the complex problem of evaluation of logistics capability in e-commerce environment, an index system model of logistics capability is established based on the method of Fuzzy-AHP in this paper. The r...In order to solve the complex problem of evaluation of logistics capability in e-commerce environment, an index system model of logistics capability is established based on the method of Fuzzy-AHP in this paper. The results show that the method of Fuzzy-AHP is a powerful and flexible multi-criteria decision-making tool for dealing with complex problems where both qualitative and quantitative aspects need to be considered, and the human preference model is uncertain and decision-makers are reluctant or unable to assign exact numerical values to the comparison judgments. The evaluation model of logistics capability based on method of Fuzzy-AHP can help to make an effective decision in the evaluation of logistics capability. By this way we can effectively deal with the uncertainty and vagueness in the evaluation process of logistics capability. Logistics companies can diagnose their own weaknesses in the area of logistics and enhance their competitiveness.展开更多
In this paper, we introduce the complex modulus to express the viscoelasticity of a medium. According to the correspondence principle, the Biot-Squirt （BISQ） equations in the steady-state case are presented for the ...In this paper, we introduce the complex modulus to express the viscoelasticity of a medium. According to the correspondence principle, the Biot-Squirt （BISQ） equations in the steady-state case are presented for the space-frequency domain described by solid displacements and fluid pressure in a homogeneous viscoelastic medium. The effective bulk modulus of a multiphase flow is computed by the Voigt formula, and the characteristic squirt-flow length is revised for the gas-included case. We then build a viscoelastic BISQ model containing a multiphase flow. Through using this model, wave dispersion and attenuation are studied in a medium with low porosity and low permeability. Furthermore, this model is applied to observed interwell seismic data. Analysis of these data reveals that the viscoelastic parameter tan6 is not a constant. Thus, we present a linear frequen- cy-dependent function in the interwell seismic frequency range to express tanG. This improves the fit between the observed data and theoretical results.展开更多
In this paper, a susceptible-exposed infective-recovered-susceptible （SEIRS） epidemic model with vaccination has been formulated. We studied the global stability of the corresponding single-group model, multi-group ...In this paper, a susceptible-exposed infective-recovered-susceptible （SEIRS） epidemic model with vaccination has been formulated. We studied the global stability of the corresponding single-group model, multi-group model with strongly connected network and multi-group model without strongly connected network by means of analyzing their basic reproduction numbers and the application of Lyapunov functionals. Finally, we provide some numerical simulations to illustrate our analysis results.展开更多
基金Under the auspices of Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-YW-340,KZCX2-YW-341)Key Project of Jilin Province Scientific and Technological Development Program (No. 20080425)
文摘This study applied a multivariate model based on three simulated sensors to estimating water quality variables in Shitoukoumen Reservoir,Changchun City,Jilin Province,China,including concentration of total suspended matter,concentration of chlorophyll-a and non-pigment matter absorption.Two field campaigns for spectra measurements with a total of 40 samples were carried out on June 13 and September 23,2008.The in-situ spectra were recalculated to the spectral bands and sensitivities of the instruments applied in this paper,i.e.Landsat TM,Alos and P6,by using the average method.And the recalculated spectra were used for estimating water quality variables by the single model and multivariate model.The results show that the multivariate model is superior to the single model as the multivariate model takes the combined effects of water components into consideration and can estimate water quality variables simultaneously.According to R2 and RMSE,Alos is superior to other sensors for water quality variables estimation although the precision of non-pigment matter absorption inversion performed the second.
文摘In this study, we propose a new temperature compensation control strategy for a multi-cavity hot runner injection molding system, At first, the melt filling time of each cavity can be measured by installing temperature sensors on the position around end filling area, and filling time difference between the various cavities can be calculated. Then the melt temperature of each hot nozzle can be adjusted automatically by a control strategy established based on the Fuzzy Theory and a program compiled with LABVIEW software. Temperature changes the melt mobility, so the adjustment of temperature can equalize the filling time of the melt in each cavity, which can reduced the mass deviation between each cavity and make product properties of each cavity consistent. The conclusion of the experiment is as follows： For this contact lens box of a four-cavity Hot Runner mold, by applying hot runner temperature compensation control system, time difference can be reduced from 0.05 s to 0.01 s at each cavity, and the mass Standard deviation of the four cavity can be improved from 0.006 to 0.002. The ratio of imbalance can be reduced from 20% to 4%. Hence, the hot runner temperature compensation control system has significant feasibility and high potential in improving melt flow balance of multi-cavity molding application.
文摘Impacts of returns on assets are not instantaneously felt, since there is lag period. In this paper we consider the problem of developing a model for the conditional QPDL （quantile polynomial distributed lag） and investigate the influences of the conditioning variables on the location, scale and shape parameters of the QPDL model. As an economic application, we consider the production of rubber and its price returns ofSri Lanka. From the analysis we observed that the QPDL model applications were better estimators than the PDL （Polynomial Distributed Lag） models.
基金Supported by the National High Technology Research and Development Program of China(No.2012AA061101)the Key Laboratory of Intelligent Perception and Systems for High-Dimensional Information(Nanjing University of Science and Technology),Ministry of Education(No.3092013012205)
文摘There is one problem existing in gyroscope signal processing,which is that single models can＇ t adapt to change of carrier maneuvering process.Since it is difficult to identify the angular motion state of gyroscope carriers,interacting multiple model （IMM） is employed here to solve the problem.The Kalman filter-based IMM （IMMKF） algorithm is explained in detail and its application in gyro signal processing is introduced.And with the help of the Singer model,the system model set of gyro outputs is constructed.In order to demonstrate the effectiveness of the proposed approach,static experiment and dynamic experiment are carried out respectively.Simulation analysis results indicate that the IMMKF algorithm is excellent in eliminating gyro drift errors,which could adapt to the change of carrier maneuvering process well.
文摘For the further design of the particular gearbox components, the alternating cycles of the respective application mean an often insufficient knowledge of the actual loads occuring in use. Especially for the application within lifting units, such dynamic load cycles are very difficult to pre-estimate. The so-called slack rope test represents the most critical point in the load cycle and provides a special challenge for the gearbox design. Because of this missing expert knowledge, a test bench of such an application is installed and applied to practical movement cycles. Besides the test bench, a multi-body simulation model of the whole system is mapped within the MBS （multi-body simulation） environment SIMPACK. To verify this simulation model, the results are compared with the respective measurements of the test bench. These comparisons show very good agreements. Thus, one of the major advantages of using such simulation tools is the possibility to re-evaluate the internal and external loads during the whole design process. Finally, these simulations serve as a clarification of the load spectrum of the different drivetrain components. Gearbox series or different modifications of the design can now be analyzed prospectively without extensive testing.
文摘In order to solve the complex problem of evaluation of logistics capability in e-commerce environment, an index system model of logistics capability is established based on the method of Fuzzy-AHP in this paper. The results show that the method of Fuzzy-AHP is a powerful and flexible multi-criteria decision-making tool for dealing with complex problems where both qualitative and quantitative aspects need to be considered, and the human preference model is uncertain and decision-makers are reluctant or unable to assign exact numerical values to the comparison judgments. The evaluation model of logistics capability based on method of Fuzzy-AHP can help to make an effective decision in the evaluation of logistics capability. By this way we can effectively deal with the uncertainty and vagueness in the evaluation process of logistics capability. Logistics companies can diagnose their own weaknesses in the area of logistics and enhance their competitiveness.
基金supported by the National Natural Sciences Foundation of China(Grant Nos.41390452 and 11002025)the National Science Foundation for Distinguished Young Scholars of China(Grant No.40725012)
文摘In this paper, we introduce the complex modulus to express the viscoelasticity of a medium. According to the correspondence principle, the Biot-Squirt （BISQ） equations in the steady-state case are presented for the space-frequency domain described by solid displacements and fluid pressure in a homogeneous viscoelastic medium. The effective bulk modulus of a multiphase flow is computed by the Voigt formula, and the characteristic squirt-flow length is revised for the gas-included case. We then build a viscoelastic BISQ model containing a multiphase flow. Through using this model, wave dispersion and attenuation are studied in a medium with low porosity and low permeability. Furthermore, this model is applied to observed interwell seismic data. Analysis of these data reveals that the viscoelastic parameter tan6 is not a constant. Thus, we present a linear frequen- cy-dependent function in the interwell seismic frequency range to express tanG. This improves the fit between the observed data and theoretical results.
基金This research is supported by National Natural Science Foundation of China （No. 11371111）, Weihai Science and Technology Development Plan Project （No. 2013DXGJ06） and Shandong Provincial Natural Science Foundation of China （No. ZR2015AM018）.
文摘In this paper, a susceptible-exposed infective-recovered-susceptible （SEIRS） epidemic model with vaccination has been formulated. We studied the global stability of the corresponding single-group model, multi-group model with strongly connected network and multi-group model without strongly connected network by means of analyzing their basic reproduction numbers and the application of Lyapunov functionals. Finally, we provide some numerical simulations to illustrate our analysis results.
