The job shop scheduling problem is a classical combinatorial optimization challenge frequently encountered in manufacturing systems.It involves determining the optimal execution sequences for a set of jobs on various ...The job shop scheduling problem is a classical combinatorial optimization challenge frequently encountered in manufacturing systems.It involves determining the optimal execution sequences for a set of jobs on various machines to maximize production efficiency and meet multiple objectives.The Non-dominated Sorting Genetic Algorithm Ⅲ(NSGA-Ⅲ)is an effective approach for solving the multi-objective job shop scheduling problem.Nevertheless,it has some limitations in solving scheduling problems,including inadequate global search capability,susceptibility to premature convergence,and challenges in balancing convergence and diversity.To enhance its performance,this paper introduces a strengthened dominance relation NSGA-Ⅲ algorithm based on differential evolution(NSGA-Ⅲ-SD).By incorporating constrained differential evolution and simulated binary crossover genetic operators,this algorithm effectively improves NSGA-Ⅲ’s global search capability while mitigating pre-mature convergence issues.Furthermore,it introduces a reinforced dominance relation to address the trade-off between convergence and diversity in NSGA-Ⅲ.Additionally,effective encoding and decoding methods for discrete job shop scheduling are proposed,which can improve the overall performance of the algorithm without complex computation.To validate the algorithm’s effectiveness,NSGA-Ⅲ-SD is extensively compared with other advanced multi-objective optimization algorithms using 20 job shop scheduling test instances.The experimental results demonstrate that NSGA-Ⅲ-SD achieves better solution quality and diversity,proving its effectiveness in solving the multi-objective job shop scheduling problem.展开更多
Indoor heating with an electrical heating cable,which has no harmful emissions to the environment,is an attractive way for radiant floor heating.To improve the heat transfer efficiency,a novel structure of the heating...Indoor heating with an electrical heating cable,which has no harmful emissions to the environment,is an attractive way for radiant floor heating.To improve the heat transfer efficiency,a novel structure of the heating cable was designed by proposing the concept of the aluminum finned sheath.The transient heat transfer model from the embedded heating cables to the floor is established to validate the feasibility of this novel cable.The effects of the fin number and shape on the cable’s temperature and heat flux distribution were analyzed.The results show that,with the specific volume of the sheath,increasing the number of fins can enhance the thermal diffusion capacity of the heating cable and reduce its temperature.Rectangular fins exhibit higher performance for heat dissipation than triangular fins due to their larger surface area.The simulation result shows that the floor temperature above the cable rises from 5°C to 22.5°C after a 2-h heating process,which was validated with experimental results.The results and suggestions can provide reference to guide the design of the heating cable.展开更多
The problem of capacity shortage in some airports needs to be dealt with sustainable solutions including a more efficient use of the existing runway slots at the airports. The Collaborative Decision Making(CDM) is a...The problem of capacity shortage in some airports needs to be dealt with sustainable solutions including a more efficient use of the existing runway slots at the airports. The Collaborative Decision Making(CDM) is an important approach applied to Air Traffic Management(ATM)to achieve this efficient use of the slots allocation. Using the Matching approach for two-sided markets of Game theory, the Top Trading Cycle CDM(TTC-CDM) algorithm developed in this research is an extension of the CDM approach aggregating the Ground Delay Program(GDP)of the air sector. The paper compared the developed TTC-CDM model to the existing models such as the conventional Compression algorithm in CDM, the Trade Cycle algorithm and the Deferred Acceptance CDM(DA-CDM) model to evaluate the performance of the proposed model. Through a case study, the results show the effective application of TTC-CDM model to slot allocation in ATM and also presents the advantage of considering the preferences of airport managers beside ATC controllers and airlines in the decision processing.展开更多
Mg alloy AZ31 with ~79% (volume fraction of scattering less than 30°) basal-fiber texture through hot extrusion exhibits strong grain-size dependent yield strength, Samples with grain sizes varying from 4,5 to ...Mg alloy AZ31 with ~79% (volume fraction of scattering less than 30°) basal-fiber texture through hot extrusion exhibits strong grain-size dependent yield strength, Samples with grain sizes varying from 4,5 to 22,3 μm were obtained by altering annealing time durations, The Hall-Petch relations of tension and compression are σ.2 = 86+200d^-1/2 and σ0.2 = 17 + 327d^-1/2, respectively, Considering the correlation between grain orientation and deformation modes, a novel weighted average method of calculating friction stress Cro was proposed, and results of calculation agreed with the experimental ones, which can reasonably understand the yielding behavior in tension and compression,展开更多
基金in part supported by the Key Research and Development Project of Hubei Province(Nos.2020BAB1141,2023BAB094)the Key Project of Science and Technology Research ProgramofHubei Educational Committee(No.D20211402)+1 种基金the Teaching Research Project of Hubei University of Technology(No.XIAO2018001)the Project of Xiangyang Industrial Research Institute of Hubei University of Technology(No.XYYJ2022C04).
文摘The job shop scheduling problem is a classical combinatorial optimization challenge frequently encountered in manufacturing systems.It involves determining the optimal execution sequences for a set of jobs on various machines to maximize production efficiency and meet multiple objectives.The Non-dominated Sorting Genetic Algorithm Ⅲ(NSGA-Ⅲ)is an effective approach for solving the multi-objective job shop scheduling problem.Nevertheless,it has some limitations in solving scheduling problems,including inadequate global search capability,susceptibility to premature convergence,and challenges in balancing convergence and diversity.To enhance its performance,this paper introduces a strengthened dominance relation NSGA-Ⅲ algorithm based on differential evolution(NSGA-Ⅲ-SD).By incorporating constrained differential evolution and simulated binary crossover genetic operators,this algorithm effectively improves NSGA-Ⅲ’s global search capability while mitigating pre-mature convergence issues.Furthermore,it introduces a reinforced dominance relation to address the trade-off between convergence and diversity in NSGA-Ⅲ.Additionally,effective encoding and decoding methods for discrete job shop scheduling are proposed,which can improve the overall performance of the algorithm without complex computation.To validate the algorithm’s effectiveness,NSGA-Ⅲ-SD is extensively compared with other advanced multi-objective optimization algorithms using 20 job shop scheduling test instances.The experimental results demonstrate that NSGA-Ⅲ-SD achieves better solution quality and diversity,proving its effectiveness in solving the multi-objective job shop scheduling problem.
文摘Indoor heating with an electrical heating cable,which has no harmful emissions to the environment,is an attractive way for radiant floor heating.To improve the heat transfer efficiency,a novel structure of the heating cable was designed by proposing the concept of the aluminum finned sheath.The transient heat transfer model from the embedded heating cables to the floor is established to validate the feasibility of this novel cable.The effects of the fin number and shape on the cable’s temperature and heat flux distribution were analyzed.The results show that,with the specific volume of the sheath,increasing the number of fins can enhance the thermal diffusion capacity of the heating cable and reduce its temperature.Rectangular fins exhibit higher performance for heat dissipation than triangular fins due to their larger surface area.The simulation result shows that the floor temperature above the cable rises from 5°C to 22.5°C after a 2-h heating process,which was validated with experimental results.The results and suggestions can provide reference to guide the design of the heating cable.
基金partially supported by the Brazilian National Council for Scientific and Technological Development(CNPq Grant No.304903/2013-2)
文摘The problem of capacity shortage in some airports needs to be dealt with sustainable solutions including a more efficient use of the existing runway slots at the airports. The Collaborative Decision Making(CDM) is an important approach applied to Air Traffic Management(ATM)to achieve this efficient use of the slots allocation. Using the Matching approach for two-sided markets of Game theory, the Top Trading Cycle CDM(TTC-CDM) algorithm developed in this research is an extension of the CDM approach aggregating the Ground Delay Program(GDP)of the air sector. The paper compared the developed TTC-CDM model to the existing models such as the conventional Compression algorithm in CDM, the Trade Cycle algorithm and the Deferred Acceptance CDM(DA-CDM) model to evaluate the performance of the proposed model. Through a case study, the results show the effective application of TTC-CDM model to slot allocation in ATM and also presents the advantage of considering the preferences of airport managers beside ATC controllers and airlines in the decision processing.
基金the support of the National Natural Science Foundation of China(51271046 and 51471041)
文摘Mg alloy AZ31 with ~79% (volume fraction of scattering less than 30°) basal-fiber texture through hot extrusion exhibits strong grain-size dependent yield strength, Samples with grain sizes varying from 4,5 to 22,3 μm were obtained by altering annealing time durations, The Hall-Petch relations of tension and compression are σ.2 = 86+200d^-1/2 and σ0.2 = 17 + 327d^-1/2, respectively, Considering the correlation between grain orientation and deformation modes, a novel weighted average method of calculating friction stress Cro was proposed, and results of calculation agreed with the experimental ones, which can reasonably understand the yielding behavior in tension and compression,