The paper analyses the principal and the methods of the optimal design of refrigerating plants.It compares the method of the static characteristics with that of the thermo dynamics,and puts the stress on the discussio...The paper analyses the principal and the methods of the optimal design of refrigerating plants.It compares the method of the static characteristics with that of the thermo dynamics,and puts the stress on the discussion of the latter which is general researched and applied in the refrigeration field.展开更多
The goal of this effort was to provide a static and dynamic collaborative optimization （CO） model for the design of ship hull structure. The CO model integrated with static, mode and dynamic analyses. In the system-...The goal of this effort was to provide a static and dynamic collaborative optimization （CO） model for the design of ship hull structure. The CO model integrated with static, mode and dynamic analyses. In the system-level optimization model, a new objective function was advised, integrating all the subsystem-levels＇ objective functions, so as to eliminate the effects of dimensions and magnitude order. The proposed CO architecture enabled multi-objectives of the system and subsystem-level to be considered at both levels during optimization. A bi-level optimization strategy was advised, using the multi-island genetic algorithm. The proposed model was demonstrated with a deck optimization problem of container ship stern. The analysis progress and results of example show that the CO strategy is not only feasible and reliable, but also well suited for use in actual optimization problems of ship design.展开更多
To reduce resources consumption of parallel computation system, a static task scheduling opti- mization method based on hybrid genetic algorithm is proposed and validated, which can shorten the scheduling length of pa...To reduce resources consumption of parallel computation system, a static task scheduling opti- mization method based on hybrid genetic algorithm is proposed and validated, which can shorten the scheduling length of parallel tasks with precedence constraints. Firstly, the global optimal model and constraints are created to demonstrate the static task scheduling problem in heterogeneous distributed computing systems（HeDCSs）. Secondly, the genetic population is coded with matrix and used to search the total available time span of the processors, and then the simulated annealing algorithm is introduced to improve the convergence speed and overcome the problem of easily falling into local minimum point, which exists in the traditional genetic algorithm. Finally, compared to other existed scheduling algorithms such as dynamic level scheduling （ DLS）, heterogeneous earliest finish time （HEFr）, and longest dynamic critical path（ LDCP）, the proposed approach does not merely de- crease tasks schedule length, but also achieves the maximal resource utilization of parallel computa- tion system by extensive experiments.展开更多
A static and dynamic collaborative optimization method for materials and structure with uniform periodic microstructure is presented.The sensitivity formulae of hierarchical optimization,i.e.,material design,structure...A static and dynamic collaborative optimization method for materials and structure with uniform periodic microstructure is presented.The sensitivity formulae of hierarchical optimization,i.e.,material design,structure design and integrated design for porous metals,are given.On the base of the hierarchical optimization model,numerical experiments of an MBB beam and a cantilever one were carried out.Based on porous metals bearing multi-functionality,the differences and applicability of hierarchical optimization are discussed in the structure loading field.It is concluded that structure design is mainly oriented to structure efficiency,material design is mainly oriented to multi-functionality,and integrated design is oriented to structure efficiency and multi-functionality.This work provides some useful ideas for the selection of porous metals design method.展开更多
文摘The paper analyses the principal and the methods of the optimal design of refrigerating plants.It compares the method of the static characteristics with that of the thermo dynamics,and puts the stress on the discussion of the latter which is general researched and applied in the refrigeration field.
基金Knowledge-based Ship-design Hyper-integrated Platform(KSHIP) of Ministry of Education and Ministry of Finance,P. R. China(No.200512)
文摘The goal of this effort was to provide a static and dynamic collaborative optimization （CO） model for the design of ship hull structure. The CO model integrated with static, mode and dynamic analyses. In the system-level optimization model, a new objective function was advised, integrating all the subsystem-levels＇ objective functions, so as to eliminate the effects of dimensions and magnitude order. The proposed CO architecture enabled multi-objectives of the system and subsystem-level to be considered at both levels during optimization. A bi-level optimization strategy was advised, using the multi-island genetic algorithm. The proposed model was demonstrated with a deck optimization problem of container ship stern. The analysis progress and results of example show that the CO strategy is not only feasible and reliable, but also well suited for use in actual optimization problems of ship design.
基金Supported by the National Natural Science Foundation of China(No.61401496)
文摘To reduce resources consumption of parallel computation system, a static task scheduling opti- mization method based on hybrid genetic algorithm is proposed and validated, which can shorten the scheduling length of parallel tasks with precedence constraints. Firstly, the global optimal model and constraints are created to demonstrate the static task scheduling problem in heterogeneous distributed computing systems（HeDCSs）. Secondly, the genetic population is coded with matrix and used to search the total available time span of the processors, and then the simulated annealing algorithm is introduced to improve the convergence speed and overcome the problem of easily falling into local minimum point, which exists in the traditional genetic algorithm. Finally, compared to other existed scheduling algorithms such as dynamic level scheduling （ DLS）, heterogeneous earliest finish time （HEFr）, and longest dynamic critical path（ LDCP）, the proposed approach does not merely de- crease tasks schedule length, but also achieves the maximal resource utilization of parallel computa- tion system by extensive experiments.
基金supported by the National Basic Research Program of China ("973" Project) (Grant No. 2010CB832700)the Science and Technology Development Fundation of Academy of Engineering Physics(Grant No. 2008A0302011)
文摘A static and dynamic collaborative optimization method for materials and structure with uniform periodic microstructure is presented.The sensitivity formulae of hierarchical optimization,i.e.,material design,structure design and integrated design for porous metals,are given.On the base of the hierarchical optimization model,numerical experiments of an MBB beam and a cantilever one were carried out.Based on porous metals bearing multi-functionality,the differences and applicability of hierarchical optimization are discussed in the structure loading field.It is concluded that structure design is mainly oriented to structure efficiency,material design is mainly oriented to multi-functionality,and integrated design is oriented to structure efficiency and multi-functionality.This work provides some useful ideas for the selection of porous metals design method.
