In order to design the press bend forming path of aircraft integral panels,a novel optimization method was proposed, which integrates FEM equivalent model based on previous study,the artificial neural network response...In order to design the press bend forming path of aircraft integral panels,a novel optimization method was proposed, which integrates FEM equivalent model based on previous study,the artificial neural network response surface,and the genetic algorithm.First,a multi-step press bend forming FEM equivalent model was established,with which the FEM experiments designed with Taguchi method were performed.Then,the BP neural network response surface was developed with the sample data from the FEM experiments.Furthermore,genetic algorithm was applied with the neural network response surface as the objective function. Finally,verification was carried out on a simple curvature grid-type stiffened panel.The forming error of the panel formed with the optimal path is only 0.098 39 and the calculating efficiency has been improved by 77%.Therefore,this novel optimization method is quite efficient and indispensable for the press bend forming path designing.展开更多
The arbitrary space-shape free form deformation （FFD） method developed in this paper is based on non-uniform rational B-splines （NURBS） basis function and used for the integral parameterization of nacelle-pylon ge...The arbitrary space-shape free form deformation （FFD） method developed in this paper is based on non-uniform rational B-splines （NURBS） basis function and used for the integral parameterization of nacelle-pylon geometry. The multi-block structured grid deformation technique is established by Delaunay graph mapping method. The optimization objects of aerodynamic characteristics are evaluated by solving NavierStokes equations on the basis of multi-block structured grid. The advanced particle swarm optimization （PSO） is utilized as search algorithm, which com-bines the Kriging model as surrogate model during optimization. The optimization system is used for optimizing the nacelle location of DLR-F6 wing-body-pylon-nacelle. The results indicate that the aerodynamic interference between the parts is significantly reduced. The optimization design system established in this paper has extensive applications and engineering value.展开更多
In the long-term symbiotic evolution process,the town areas along the Yangtze River and its natural and cultural landscapes have presented a sound "city-scene" landscape form. But with the implementation of ...In the long-term symbiotic evolution process,the town areas along the Yangtze River and its natural and cultural landscapes have presented a sound "city-scene" landscape form. But with the implementation of the Three Gorges project,the town relocation as well as the flooding in the natural and human landscape area,the original harmonious "city-scene" pattern started to collapse and fell into the situation of "fragmentation" and "islanding". The differentiation between city and landscape,uncoordinated scale and fractured urban context become pressing issues that affect the integral form optimization of the town areas. This paper aims at responding to the call of the government about proceeding the construction of the Yangtze River economic belt under the ecological and green strategy and seeking an attuned "cityscene" relationship of the town area. Based on the analysis of the dynamic evolution of the "city-scene" relationship,the paper also pointed out that the urban construction around the reservoir area in the postThree Gorges era was the key stage of "scene-city" integration and symbiosis while the maintenance of scenery pattern,the harmony of space scale and the protection of living culture should be applied as the vital strategies.展开更多
The structure stiffness of presses has great effects on the forming precision of workpieces, especially in near-net or net shape forming. Conventionally the stiffness specification of presses is empirically determined...The structure stiffness of presses has great effects on the forming precision of workpieces, especially in near-net or net shape forming. Conventionally the stiffness specification of presses is empirically determined, resulting in poor designs with insufficient or over sufficient stiffness of press structures. In this paper, an approach for the structure design of hydraulic presses is proposed, which is forming-precision-driven and can make presses costeffective by lightweight optimization. The approach consists of five steps:(1)the determination of the press stiffness specification in terms of the forming precision requirement of workpieces;(2)the conceptual design of the press structures according to the stiffness and workspace specifications, and the structure configuration of the press;(3)the prototype design of the press structures by equivalently converting the conceptual design to prototypes;(4)the selection of key structure parameters by sensitivity analysis of the prototype design; and(5)the optimization of the prototype design. The approach is demonstrated and validated through a case study of the structure design of a 100 MN hydraulic press.展开更多
With the advancements in computer technology,the simulation-based design(SBD)technology has emerged as a highly effective method for hull form optimization.The SBD approach often employs various methods to evaluate th...With the advancements in computer technology,the simulation-based design(SBD)technology has emerged as a highly effective method for hull form optimization.The SBD approach often employs various methods to evaluate the hydrodynamic performance of the sample ships.Although the surrogate model is applied to SBD method to replace time-consuming evaluation,many high-fidelity data are typically required to guarantee the accuracy of the surrogate model,resulting in significant computational costs.To improve the optimization efficiency and reduce computational burdens,we propose a novel hull form optimization framework utilizing the multi-fidelity deep neural network(MFDNN),leveraging multi-source data fusion and transfer learning.This framework constructs an accurate multi-fidelity surrogate model which correlates design parameters with hydrodynamic performance of the hull by blending data with different fidelity.Besides,computational fluid dynamics(CFD)evaluations based on viscous flow are served as the high-fidelity model,while potential-theory evaluations represent the low-fidelity model.Then,this framework is validated using mathematical functions to prove its practicability in optimization.Finally,the optimization design of the resistance of the DTMB-5415 ship is carried out.Our findings demonstrate that this framework can take into account both efficiency and accuracy,which is preferable in optimization tasks.The optimized hull form obtained by the framework has better resistance performance.展开更多
The design and optimization of ship hull forms play a crucial role in enhancing the performance and efficiency of marine vessels.This study focuses on integrating a cylindrical central body part within a conventional ...The design and optimization of ship hull forms play a crucial role in enhancing the performance and efficiency of marine vessels.This study focuses on integrating a cylindrical central body part within a conventional ship hull to explore its impact on hydrodynamic characteristics and overall vessel performance.The research employs hydrodynamical concepts,parametric studies,and optimization algorithms to analyze the design space systematically.The aim of including the cylindrical central body is to investigate its influence on reducing resistance,improving fuel efficiency,and enhancing maneuverability.A new optimization model based on the cylindrical body inclusion in the hull form is developed.The existing generalized reduced gradient(GRG)optimization method is also adopted to determine the accuracy of the proposed methodology.It is revealed that the resistance predicted by the GRG method is much closer to the original result of the parent hull form.A container vessel is taken as a case study example.The new,simplified,approach developed here provides a greater reduction in the resistance values of the case study vessel.Hence,the adoption of a cylindrical hull form in ship design can improve hydrodynamic performance.Although the results from the GRG method and the new scheme agree within the speed range of 0-5 m/s,some deviations are noted.In conclusion,it is observed that although the inclusion of the cylindrical body together with the adoption of the optimum design scheme is capable of improving the resistance performance of a ship,further studies are necessary to understudy the effects of this approach on the other vessel performance metrics.展开更多
Hydrodynamic optimization of the hull forms can be realized through the implementation and integration of computational tools that consist of a hydrodynamic module, a hull surface representation and modification modul...Hydrodynamic optimization of the hull forms can be realized through the implementation and integration of computational tools that consist of a hydrodynamic module, a hull surface representation and modification module, and an optimization module. In the present paper, a new bulbous bow generation and modification technique has been developed and integrated into the hull surface representation and modification module. A radial basis function based surrogate model is developed to approximate the objective functions and reduce the computing cost. A multi-objective artificial bee colony optimization algorithm is implemented and integra- ted into the optimization module. To illustrate the integrated hydrodynamic optimization tools, a cargo ship is optimized for reduced drag. The optimal hull forms obtained are then validated computationally and experimentally. Validation results show that the prese- nt tools can be used efficiently and effectively in the simulation based design of the hull forms for reduced drag.展开更多
This review paper presents an overview of simulation-based hydrodynamic design optimization of ship hull forms. A computational tool that is aimed to accomplishing early-stage simulation-based design in terms of hydro...This review paper presents an overview of simulation-based hydrodynamic design optimization of ship hull forms. A computational tool that is aimed to accomplishing early-stage simulation-based design in terms of hydrodynamic performance is discussed in detail. The main components of this computational tool consist of a hydrodynamic module, a hull surface modeling module, and an optimization module. The hydrodynamic module includes both design-oriented simple CFD tools and high-fidelity CFD tools. These integrated CFD tools are used for evaluating hydrodynamic performances at different design stages. The hull sur- face modeling module includes various techniques for ship hull surface representation and modification. This module is used to automatically produce hull forms or modify existing hull forms in terms of hydrodynamic performance and design constraints. The optimization module includes various optimization algorithms and surrogate models, which are used to determine optimal designs in terms of given hydrodynamic performance. As an illustration of the computational tool, a Series 60 hull is optimized for reduced drag using three different modification strategies to outline the specific procedure for conducting simulation-based hydrodynamic design of ship hull forms using the present tool. Numerical results show that the present tool is well suited for the hull form design optimization at early design stage because it can produce effective optimal designs within a short period of time.展开更多
Australia’s national energy system is heavily reliant on coal-fired power plants and requires quick action to de-crease CO_(2)emissions in order to meet the Paris climate change agreement by 2030.As a good alternativ...Australia’s national energy system is heavily reliant on coal-fired power plants and requires quick action to de-crease CO_(2)emissions in order to meet the Paris climate change agreement by 2030.As a good alternative to coal power,renewable resources can produce the required energy for Australia while keeping the environment clean.The annual amount of falling solar irradiation in Australia is a few thousand times higher than its energy consumption,but the amount of the collected solar energy is unsatisfactory.In Perth,the sunniest city in Aus-tralia,one-third of the residential dwellings have roof-mounted solar collector systems.However,there have been limited studies into the integration of these systems in building design and it is still unknown which roof design can deliver maximum efficiency based on the local environmental conditions.Therefore,the aims of this study are to determine the optimum residential roof design in Perth,Western Australia and to maximise extracted solar power throughout a year.To reach this aim,a combination of analytical modelling,numerical simulation,and evolutionary algorithm methods have been selected.At first,a series of detailed mathematical calculations were performed in Excel to find the optimum solar collector mounting settings.In the numerical simulation,the exam-ination was repeated in the Rhino-Grasshopper interface to verify the earlier findings and calibrate the chosen simulation package with the help of parametric architecture.In the last step,a wide range of housing roof shapes has been tested by evolutionary algorithm plugin-Galapagos,to find the optimum roof shape design in the given context.Our results show that,unlike the traditional approach and common belief,a roof shape with a 25-degree tilt angle,170-175 azimuth angle,and aspect ratio of 1:1.2 is optimum to gain maximum solar gaining annually.Moreover,this study advances the knowledge of solar capturing by suggesting a new parameter-oblique angle-in finding the optimum roof shape design.After evaluating the importance of the mentioned factors,it is found that,after tilt angle,the oblique angle is the most effective parameter in rooftop solar gaining,higher than roof aspect ratio and azimuth angle.In conclusion,our results demonstrate that an‘oblique shed roof design’can generate 15.7%higher solar radiation compared to the base case.The findings of this study can be applied by architects,construction companies,and householders to optimize the solar gaining in the future of the residential building in Perth.展开更多
The performance of ground moving target detection for distributed satellites will be affected signifi-cantly when there is an image registration error,clutter decorrelation and array error.In this paper,a new approach...The performance of ground moving target detection for distributed satellites will be affected signifi-cantly when there is an image registration error,clutter decorrelation and array error.In this paper,a new approach to moving target detection and relocation is proposed based on multi-channel and multi-pixel adap-tive signal processing in an image domain.First,multi-channel and multi-pixel joint data are equated to a simple array model.Given that there is an image registration error,the real steering vector of the moving target can be estimated through a space projection approach.The optimal beam forming approach is used to cancel clutter,and at the same time the cross-track velocity of the mov-ing target can be determined by searching for the peak value of the cost function.The moving target can then be relocated on the SAR image.The simulation results indicate that this method has a good robustness to image registration error,clutter decorrelation and array error.The detection performance and the estimation accuracy are significantly improved.展开更多
Purpose:The purpose of this paper is to develop a novel interval Multi-Objective Optimization by a Ratio Analysis plus the Full Multiplicative Form(MULTIMOORA)with combination weights to evaluate the employment qualit...Purpose:The purpose of this paper is to develop a novel interval Multi-Objective Optimization by a Ratio Analysis plus the Full Multiplicative Form(MULTIMOORA)with combination weights to evaluate the employment quality of college graduates,where the criteria are expressed by interval numbers and the weights of criteria are completely unknown.Design/methodology/approach:Firstly,considering the subjective uncertainty of the weights of the criteria,the interval best worst method(I-BWM)was present to determine the subjective weights of the criteria.Secondly,bythe improvedinterval numberdistance measure,an improved interval deviationmaximizationmethod(I-MDM)was introduced to detemine the objective weights.In the following,based on the I-BWM and the improved I-MDM,a combination weighting method that takes into account the subjective and objective weights is proposed.Finally,a multi-criteria decision-making method based on the interval MULTIMOORA with combination weights is present toevaluate the employment quality of college graduates,and then a comparative analysis withsome of the existing distance measures of interval numberswas conducted to illustrate the flexibility.Findings:According to the data of the Report on Employment Quality of Chinese College Graduats released by MycosResearchInstitutein2016:2020and2021:2022,theproposedmethodwasusedtoevaluate theemployment quality of college graduates during the period before and after the COVID-19 epidemic.The results verify that the method is more reasonable because the subjective and objective weights of the criteria can be fully considered.Finally,the feasibility and practicability of the proposed method are further verified by varying parameters.Originality/value:Present an evaluation method on the employment quality of college graduates based on the Interval MULTIMOORA with combination weights considering the subjective and objective weights.And the proposed method is proved that it can provide a more reasonable evaluation results.At the same time,it is verified that the feasibility and the practicability of the proposed method are affected by varying parameters in the paper.展开更多
基金Project(20091102110021)supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China
文摘In order to design the press bend forming path of aircraft integral panels,a novel optimization method was proposed, which integrates FEM equivalent model based on previous study,the artificial neural network response surface,and the genetic algorithm.First,a multi-step press bend forming FEM equivalent model was established,with which the FEM experiments designed with Taguchi method were performed.Then,the BP neural network response surface was developed with the sample data from the FEM experiments.Furthermore,genetic algorithm was applied with the neural network response surface as the objective function. Finally,verification was carried out on a simple curvature grid-type stiffened panel.The forming error of the panel formed with the optimal path is only 0.098 39 and the calculating efficiency has been improved by 77%.Therefore,this novel optimization method is quite efficient and indispensable for the press bend forming path designing.
文摘The arbitrary space-shape free form deformation （FFD） method developed in this paper is based on non-uniform rational B-splines （NURBS） basis function and used for the integral parameterization of nacelle-pylon geometry. The multi-block structured grid deformation technique is established by Delaunay graph mapping method. The optimization objects of aerodynamic characteristics are evaluated by solving NavierStokes equations on the basis of multi-block structured grid. The advanced particle swarm optimization （PSO） is utilized as search algorithm, which com-bines the Kriging model as surrogate model during optimization. The optimization system is used for optimizing the nacelle location of DLR-F6 wing-body-pylon-nacelle. The results indicate that the aerodynamic interference between the parts is significantly reduced. The optimization design system established in this paper has extensive applications and engineering value.
基金Sponsored by:National Key Technology of China(2012BAJ15B00)Efficiency Optimization of Key Technology Research on High Urban Population Density Space(2012BAJ15B03)
文摘In the long-term symbiotic evolution process,the town areas along the Yangtze River and its natural and cultural landscapes have presented a sound "city-scene" landscape form. But with the implementation of the Three Gorges project,the town relocation as well as the flooding in the natural and human landscape area,the original harmonious "city-scene" pattern started to collapse and fell into the situation of "fragmentation" and "islanding". The differentiation between city and landscape,uncoordinated scale and fractured urban context become pressing issues that affect the integral form optimization of the town areas. This paper aims at responding to the call of the government about proceeding the construction of the Yangtze River economic belt under the ecological and green strategy and seeking an attuned "cityscene" relationship of the town area. Based on the analysis of the dynamic evolution of the "city-scene" relationship,the paper also pointed out that the urban construction around the reservoir area in the postThree Gorges era was the key stage of "scene-city" integration and symbiosis while the maintenance of scenery pattern,the harmony of space scale and the protection of living culture should be applied as the vital strategies.
基金Supported by the National Natural Science Foundation of China(No.50805101 and No.51275347)the National Key S&T Special Projects of China on CNC Machine Tools and Fundamental Manufacturing Equipment(No.2010ZX04001-191 and No.2011ZX04002-032)the Science and Technology R&D Program of Tianjin(No.13JCZDJC35000 and No.12ZCDZGX45000)
文摘The structure stiffness of presses has great effects on the forming precision of workpieces, especially in near-net or net shape forming. Conventionally the stiffness specification of presses is empirically determined, resulting in poor designs with insufficient or over sufficient stiffness of press structures. In this paper, an approach for the structure design of hydraulic presses is proposed, which is forming-precision-driven and can make presses costeffective by lightweight optimization. The approach consists of five steps:(1)the determination of the press stiffness specification in terms of the forming precision requirement of workpieces;(2)the conceptual design of the press structures according to the stiffness and workspace specifications, and the structure configuration of the press;(3)the prototype design of the press structures by equivalently converting the conceptual design to prototypes;(4)the selection of key structure parameters by sensitivity analysis of the prototype design; and(5)the optimization of the prototype design. The approach is demonstrated and validated through a case study of the structure design of a 100 MN hydraulic press.
基金Project supported by the National Natural Science Foundation of China(Grant No.52131102).
文摘With the advancements in computer technology,the simulation-based design(SBD)technology has emerged as a highly effective method for hull form optimization.The SBD approach often employs various methods to evaluate the hydrodynamic performance of the sample ships.Although the surrogate model is applied to SBD method to replace time-consuming evaluation,many high-fidelity data are typically required to guarantee the accuracy of the surrogate model,resulting in significant computational costs.To improve the optimization efficiency and reduce computational burdens,we propose a novel hull form optimization framework utilizing the multi-fidelity deep neural network(MFDNN),leveraging multi-source data fusion and transfer learning.This framework constructs an accurate multi-fidelity surrogate model which correlates design parameters with hydrodynamic performance of the hull by blending data with different fidelity.Besides,computational fluid dynamics(CFD)evaluations based on viscous flow are served as the high-fidelity model,while potential-theory evaluations represent the low-fidelity model.Then,this framework is validated using mathematical functions to prove its practicability in optimization.Finally,the optimization design of the resistance of the DTMB-5415 ship is carried out.Our findings demonstrate that this framework can take into account both efficiency and accuracy,which is preferable in optimization tasks.The optimized hull form obtained by the framework has better resistance performance.
文摘The design and optimization of ship hull forms play a crucial role in enhancing the performance and efficiency of marine vessels.This study focuses on integrating a cylindrical central body part within a conventional ship hull to explore its impact on hydrodynamic characteristics and overall vessel performance.The research employs hydrodynamical concepts,parametric studies,and optimization algorithms to analyze the design space systematically.The aim of including the cylindrical central body is to investigate its influence on reducing resistance,improving fuel efficiency,and enhancing maneuverability.A new optimization model based on the cylindrical body inclusion in the hull form is developed.The existing generalized reduced gradient(GRG)optimization method is also adopted to determine the accuracy of the proposed methodology.It is revealed that the resistance predicted by the GRG method is much closer to the original result of the parent hull form.A container vessel is taken as a case study example.The new,simplified,approach developed here provides a greater reduction in the resistance values of the case study vessel.Hence,the adoption of a cylindrical hull form in ship design can improve hydrodynamic performance.Although the results from the GRG method and the new scheme agree within the speed range of 0-5 m/s,some deviations are noted.In conclusion,it is observed that although the inclusion of the cylindrical body together with the adoption of the optimum design scheme is capable of improving the resistance performance of a ship,further studies are necessary to understudy the effects of this approach on the other vessel performance metrics.
基金sponsored by the Office of Naval Research (ONR)sponsored by the National Natural Science Foundation of China (Grant Nos. 51279147, 51179143 and 51479150)
文摘Hydrodynamic optimization of the hull forms can be realized through the implementation and integration of computational tools that consist of a hydrodynamic module, a hull surface representation and modification module, and an optimization module. In the present paper, a new bulbous bow generation and modification technique has been developed and integrated into the hull surface representation and modification module. A radial basis function based surrogate model is developed to approximate the objective functions and reduce the computing cost. A multi-objective artificial bee colony optimization algorithm is implemented and integra- ted into the optimization module. To illustrate the integrated hydrodynamic optimization tools, a cargo ship is optimized for reduced drag. The optimal hull forms obtained are then validated computationally and experimentally. Validation results show that the prese- nt tools can be used efficiently and effectively in the simulation based design of the hull forms for reduced drag.
文摘This review paper presents an overview of simulation-based hydrodynamic design optimization of ship hull forms. A computational tool that is aimed to accomplishing early-stage simulation-based design in terms of hydrodynamic performance is discussed in detail. The main components of this computational tool consist of a hydrodynamic module, a hull surface modeling module, and an optimization module. The hydrodynamic module includes both design-oriented simple CFD tools and high-fidelity CFD tools. These integrated CFD tools are used for evaluating hydrodynamic performances at different design stages. The hull sur- face modeling module includes various techniques for ship hull surface representation and modification. This module is used to automatically produce hull forms or modify existing hull forms in terms of hydrodynamic performance and design constraints. The optimization module includes various optimization algorithms and surrogate models, which are used to determine optimal designs in terms of given hydrodynamic performance. As an illustration of the computational tool, a Series 60 hull is optimized for reduced drag using three different modification strategies to outline the specific procedure for conducting simulation-based hydrodynamic design of ship hull forms using the present tool. Numerical results show that the present tool is well suited for the hull form design optimization at early design stage because it can produce effective optimal designs within a short period of time.
基金This work was supported by the University of Western Australia and the Government of Western AustralianThe first author also gratefully acknowledges the Science-Industry Fellowship form the Western Aus-tralia Department of Jobs,Tourism,Science and Innovation(Awarded to S.K.E).
文摘Australia’s national energy system is heavily reliant on coal-fired power plants and requires quick action to de-crease CO_(2)emissions in order to meet the Paris climate change agreement by 2030.As a good alternative to coal power,renewable resources can produce the required energy for Australia while keeping the environment clean.The annual amount of falling solar irradiation in Australia is a few thousand times higher than its energy consumption,but the amount of the collected solar energy is unsatisfactory.In Perth,the sunniest city in Aus-tralia,one-third of the residential dwellings have roof-mounted solar collector systems.However,there have been limited studies into the integration of these systems in building design and it is still unknown which roof design can deliver maximum efficiency based on the local environmental conditions.Therefore,the aims of this study are to determine the optimum residential roof design in Perth,Western Australia and to maximise extracted solar power throughout a year.To reach this aim,a combination of analytical modelling,numerical simulation,and evolutionary algorithm methods have been selected.At first,a series of detailed mathematical calculations were performed in Excel to find the optimum solar collector mounting settings.In the numerical simulation,the exam-ination was repeated in the Rhino-Grasshopper interface to verify the earlier findings and calibrate the chosen simulation package with the help of parametric architecture.In the last step,a wide range of housing roof shapes has been tested by evolutionary algorithm plugin-Galapagos,to find the optimum roof shape design in the given context.Our results show that,unlike the traditional approach and common belief,a roof shape with a 25-degree tilt angle,170-175 azimuth angle,and aspect ratio of 1:1.2 is optimum to gain maximum solar gaining annually.Moreover,this study advances the knowledge of solar capturing by suggesting a new parameter-oblique angle-in finding the optimum roof shape design.After evaluating the importance of the mentioned factors,it is found that,after tilt angle,the oblique angle is the most effective parameter in rooftop solar gaining,higher than roof aspect ratio and azimuth angle.In conclusion,our results demonstrate that an‘oblique shed roof design’can generate 15.7%higher solar radiation compared to the base case.The findings of this study can be applied by architects,construction companies,and householders to optimize the solar gaining in the future of the residential building in Perth.
基金supported by the National Natural Science Foundation of China(Grant No.60472097).
文摘The performance of ground moving target detection for distributed satellites will be affected signifi-cantly when there is an image registration error,clutter decorrelation and array error.In this paper,a new approach to moving target detection and relocation is proposed based on multi-channel and multi-pixel adap-tive signal processing in an image domain.First,multi-channel and multi-pixel joint data are equated to a simple array model.Given that there is an image registration error,the real steering vector of the moving target can be estimated through a space projection approach.The optimal beam forming approach is used to cancel clutter,and at the same time the cross-track velocity of the mov-ing target can be determined by searching for the peak value of the cost function.The moving target can then be relocated on the SAR image.The simulation results indicate that this method has a good robustness to image registration error,clutter decorrelation and array error.The detection performance and the estimation accuracy are significantly improved.
基金supported in part by the National Natural Science Foundation of China(No.11371130)the Youth Innovation Fund of Xiamen City(3-502Z20206020).
文摘Purpose:The purpose of this paper is to develop a novel interval Multi-Objective Optimization by a Ratio Analysis plus the Full Multiplicative Form(MULTIMOORA)with combination weights to evaluate the employment quality of college graduates,where the criteria are expressed by interval numbers and the weights of criteria are completely unknown.Design/methodology/approach:Firstly,considering the subjective uncertainty of the weights of the criteria,the interval best worst method(I-BWM)was present to determine the subjective weights of the criteria.Secondly,bythe improvedinterval numberdistance measure,an improved interval deviationmaximizationmethod(I-MDM)was introduced to detemine the objective weights.In the following,based on the I-BWM and the improved I-MDM,a combination weighting method that takes into account the subjective and objective weights is proposed.Finally,a multi-criteria decision-making method based on the interval MULTIMOORA with combination weights is present toevaluate the employment quality of college graduates,and then a comparative analysis withsome of the existing distance measures of interval numberswas conducted to illustrate the flexibility.Findings:According to the data of the Report on Employment Quality of Chinese College Graduats released by MycosResearchInstitutein2016:2020and2021:2022,theproposedmethodwasusedtoevaluate theemployment quality of college graduates during the period before and after the COVID-19 epidemic.The results verify that the method is more reasonable because the subjective and objective weights of the criteria can be fully considered.Finally,the feasibility and practicability of the proposed method are further verified by varying parameters.Originality/value:Present an evaluation method on the employment quality of college graduates based on the Interval MULTIMOORA with combination weights considering the subjective and objective weights.And the proposed method is proved that it can provide a more reasonable evaluation results.At the same time,it is verified that the feasibility and the practicability of the proposed method are affected by varying parameters in the paper.
