Evolutionary computation is a rapidly evolving field and the related algorithms have been successfully used to solve various real-world optimization problems.The past decade has also witnessed their fast progress to s...Evolutionary computation is a rapidly evolving field and the related algorithms have been successfully used to solve various real-world optimization problems.The past decade has also witnessed their fast progress to solve a class of challenging optimization problems called high-dimensional expensive problems(HEPs).The evaluation of their objective fitness requires expensive resource due to their use of time-consuming physical experiments or computer simulations.Moreover,it is hard to traverse the huge search space within reasonable resource as problem dimension increases.Traditional evolutionary algorithms(EAs)tend to fail to solve HEPs competently because they need to conduct many such expensive evaluations before achieving satisfactory results.To reduce such evaluations,many novel surrogate-assisted algorithms emerge to cope with HEPs in recent years.Yet there lacks a thorough review of the state of the art in this specific and important area.This paper provides a comprehensive survey of these evolutionary algorithms for HEPs.We start with a brief introduction to the research status and the basic concepts of HEPs.Then,we present surrogate-assisted evolutionary algorithms for HEPs from four main aspects.We also give comparative results of some representative algorithms and application examples.Finally,we indicate open challenges and several promising directions to advance the progress in evolutionary optimization algorithms for HEPs.展开更多
Group scheduling problems have attracted much attention owing to their many practical applications.This work proposes a new bi-objective serial-batch group scheduling problem considering the constraints of sequence-de...Group scheduling problems have attracted much attention owing to their many practical applications.This work proposes a new bi-objective serial-batch group scheduling problem considering the constraints of sequence-dependent setup time,release time,and due time.It is originated from an important industrial process,i.e.,wire rod and bar rolling process in steel production systems.Two objective functions,i.e.,the number of late jobs and total setup time,are minimized.A mixed integer linear program is established to describe the problem.To obtain its Pareto solutions,we present a memetic algorithm that integrates a population-based nondominated sorting genetic algorithm II and two single-solution-based improvement methods,i.e.,an insertion-based local search and an iterated greedy algorithm.The computational results on extensive industrial data with the scale of a one-week schedule show that the proposed algorithm has great performance in solving the concerned problem and outperforms its peers.Its high accuracy and efficiency imply its great potential to be applied to solve industrial-size group scheduling problems.展开更多
In the current environment of increasingly fierce competition in the tourism industry,service quality has become crucial for enhancing the competitiveness of scenic spots.This paper uses the SERVQUAL model to design a...In the current environment of increasingly fierce competition in the tourism industry,service quality has become crucial for enhancing the competitiveness of scenic spots.This paper uses the SERVQUAL model to design a service quality evaluation questionnaire that captures the gap between tourists’expectations and perceptions,using the Ciqikou Scenic Spot as a case study.Data collected from field surveys are used to comprehensively and meticulously evaluate the service quality of the Ciqikou Scenic Spot.The analysis results show that the scenic spot,with its unique folk culture experience and beautiful ecological environment,has certain advantages in terms of service quality.However,significant deficiencies exist in infrastructure and environmental hygiene.Accordingly,targeted improvement suggestions are proposed to further enhance the service quality of the Ciqikou Scenic Spot and meet the increasingly diverse and personalized needs of tourists.This study provides not only a specific service quality improvement strategy for the Ciqikou Scenic Spot but also a valuable reference for other tourist attractions.展开更多
Power is an important part of the energy industry,relating to national economy and people’s livelihood,and it is of great significance to ensure the security and stability in operation of power transmission and distr...Power is an important part of the energy industry,relating to national economy and people’s livelihood,and it is of great significance to ensure the security and stability in operation of power transmission and distribution system.Based on Wireless Sensor Network technology(WSN)and combined with the monitoring and operating requirements of power transmission and distribution system,this paper puts forward an application system for monitoring,inspection,security,and interactive service of layered power transmission and distribution system.Furthermore,this paper demonstrates the system verification projects in Wuxi,Jiangsu Province and Lianxiangyuan Community in Beijing,which have been widely used nationwide.展开更多
The addition of a small amount of oxygen improves the mechanical properties,especially plasticity,of Ti_(45.7)Zr_(33)Ni_(3)Cu_(5.8)Be_(12.5) amorphous alloy composites(AACs)at room temperature(298 K).Compared to the p...The addition of a small amount of oxygen improves the mechanical properties,especially plasticity,of Ti_(45.7)Zr_(33)Ni_(3)Cu_(5.8)Be_(12.5) amorphous alloy composites(AACs)at room temperature(298 K).Compared to the plasticity of AACs without added O(5%),the plasticity of the composites with 0.73 at.%O(nominal composition)was much higher(11%).Even at O content higher than 0.73 at.%,the AACs exhibited good plasticity.The highest plasticity of∼12.3%was observed with 2.87 at.%O.Two distinct mechanisms are proposed to explain the enhanced plasticity of the AACs.At low O content,although deformation-induced phase transformation was suppressed,a substantial amount of α" martensite was formed.The microstructural features of α" martensite,such as thinner laths and homogeneous distribution,induced the formation of multiple shear bands in the amorphous matrix.At high O content,deformation-induced phase transformation was seriously suppressed.A dispersed nanoωphase was formed during rapid solidification in AACs with O content higher than 1.45 at.%.This resulted in a weakening in the anisotropy ofβdendrites and led to their homogenous deformation.Furthermore,multiple shear bands were formed in the amorphous matrix.Apart from plasticity,the strength of the AACs also increased with an increase in the O content.This phenomenon was explained in terms of three mechanisms,viz.the solid-solution-strengthening effect of O,fine-grain strengthening of β dendrites,and secondary phase strengthening by the nano ω phase.展开更多
基金supported in part by the Natural Science Foundation of Jiangsu Province(BK20230923,BK20221067)the National Natural Science Foundation of China(62206113,62203093)+1 种基金Institutional Fund Projects Provided by the Ministry of Education and King Abdulaziz University(IFPIP-1532-135-1443)FDCT(Fundo para o Desen-volvimento das Ciencias e da Tecnologia)(0047/2021/A1)。
文摘Evolutionary computation is a rapidly evolving field and the related algorithms have been successfully used to solve various real-world optimization problems.The past decade has also witnessed their fast progress to solve a class of challenging optimization problems called high-dimensional expensive problems(HEPs).The evaluation of their objective fitness requires expensive resource due to their use of time-consuming physical experiments or computer simulations.Moreover,it is hard to traverse the huge search space within reasonable resource as problem dimension increases.Traditional evolutionary algorithms(EAs)tend to fail to solve HEPs competently because they need to conduct many such expensive evaluations before achieving satisfactory results.To reduce such evaluations,many novel surrogate-assisted algorithms emerge to cope with HEPs in recent years.Yet there lacks a thorough review of the state of the art in this specific and important area.This paper provides a comprehensive survey of these evolutionary algorithms for HEPs.We start with a brief introduction to the research status and the basic concepts of HEPs.Then,we present surrogate-assisted evolutionary algorithms for HEPs from four main aspects.We also give comparative results of some representative algorithms and application examples.Finally,we indicate open challenges and several promising directions to advance the progress in evolutionary optimization algorithms for HEPs.
基金supported by the National Natural Science Foundation of China(U1862111,U1232119)Sichuan Provincial International Cooperation Project(2017HH0030)the Innovative Research Team of Sichuan Province(2016TD0011)~~
基金This work was supported by the China Scholarship Council Scholarship,the National Key Research and Development Program of China(2017YFB0306400)the National Natural Science Foundation of China(62073069)the Deanship of Scientific Research(DSR)at King Abdulaziz University(RG-48-135-40).
文摘Group scheduling problems have attracted much attention owing to their many practical applications.This work proposes a new bi-objective serial-batch group scheduling problem considering the constraints of sequence-dependent setup time,release time,and due time.It is originated from an important industrial process,i.e.,wire rod and bar rolling process in steel production systems.Two objective functions,i.e.,the number of late jobs and total setup time,are minimized.A mixed integer linear program is established to describe the problem.To obtain its Pareto solutions,we present a memetic algorithm that integrates a population-based nondominated sorting genetic algorithm II and two single-solution-based improvement methods,i.e.,an insertion-based local search and an iterated greedy algorithm.The computational results on extensive industrial data with the scale of a one-week schedule show that the proposed algorithm has great performance in solving the concerned problem and outperforms its peers.Its high accuracy and efficiency imply its great potential to be applied to solve industrial-size group scheduling problems.
文摘In the current environment of increasingly fierce competition in the tourism industry,service quality has become crucial for enhancing the competitiveness of scenic spots.This paper uses the SERVQUAL model to design a service quality evaluation questionnaire that captures the gap between tourists’expectations and perceptions,using the Ciqikou Scenic Spot as a case study.Data collected from field surveys are used to comprehensively and meticulously evaluate the service quality of the Ciqikou Scenic Spot.The analysis results show that the scenic spot,with its unique folk culture experience and beautiful ecological environment,has certain advantages in terms of service quality.However,significant deficiencies exist in infrastructure and environmental hygiene.Accordingly,targeted improvement suggestions are proposed to further enhance the service quality of the Ciqikou Scenic Spot and meet the increasingly diverse and personalized needs of tourists.This study provides not only a specific service quality improvement strategy for the Ciqikou Scenic Spot but also a valuable reference for other tourist attractions.
基金The project was supported by the National Science and Technology Major Project of the Ministry of Science and Technology of the People’s Republic of China.
文摘Power is an important part of the energy industry,relating to national economy and people’s livelihood,and it is of great significance to ensure the security and stability in operation of power transmission and distribution system.Based on Wireless Sensor Network technology(WSN)and combined with the monitoring and operating requirements of power transmission and distribution system,this paper puts forward an application system for monitoring,inspection,security,and interactive service of layered power transmission and distribution system.Furthermore,this paper demonstrates the system verification projects in Wuxi,Jiangsu Province and Lianxiangyuan Community in Beijing,which have been widely used nationwide.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51771049 and 51790484)。
文摘The addition of a small amount of oxygen improves the mechanical properties,especially plasticity,of Ti_(45.7)Zr_(33)Ni_(3)Cu_(5.8)Be_(12.5) amorphous alloy composites(AACs)at room temperature(298 K).Compared to the plasticity of AACs without added O(5%),the plasticity of the composites with 0.73 at.%O(nominal composition)was much higher(11%).Even at O content higher than 0.73 at.%,the AACs exhibited good plasticity.The highest plasticity of∼12.3%was observed with 2.87 at.%O.Two distinct mechanisms are proposed to explain the enhanced plasticity of the AACs.At low O content,although deformation-induced phase transformation was suppressed,a substantial amount of α" martensite was formed.The microstructural features of α" martensite,such as thinner laths and homogeneous distribution,induced the formation of multiple shear bands in the amorphous matrix.At high O content,deformation-induced phase transformation was seriously suppressed.A dispersed nanoωphase was formed during rapid solidification in AACs with O content higher than 1.45 at.%.This resulted in a weakening in the anisotropy ofβdendrites and led to their homogenous deformation.Furthermore,multiple shear bands were formed in the amorphous matrix.Apart from plasticity,the strength of the AACs also increased with an increase in the O content.This phenomenon was explained in terms of three mechanisms,viz.the solid-solution-strengthening effect of O,fine-grain strengthening of β dendrites,and secondary phase strengthening by the nano ω phase.