This paper introduces an optimization method(SCE-SR)that combines shuffled complex evolution(SCE)and stochastic ranking(SR)to solve constrained reservoir scheduling problems,ranking individuals with both objectives an...This paper introduces an optimization method(SCE-SR)that combines shuffled complex evolution(SCE)and stochastic ranking(SR)to solve constrained reservoir scheduling problems,ranking individuals with both objectives and constrains considered.A specialized strategy is used in the evolution process to ensure that the optimal results are feasible individuals.This method is suitable for handling multiple conflicting constraints,and is easy to implement,requiring little parameter tuning.The search properties of the method are ensured through the combination of deterministic and probabilistic approaches.The proposed SCE-SR was tested against hydropower scheduling problems of a single reservoir and a multi-reservoir system,and its performance is compared with that of two classical methods(the dynamic programming and genetic algorithm).The results show that the SCE-SR method is an effective and efficient method for optimizing hydropower generation and locating feasible regions quickly,with sufficient global convergence properties and robustness.The operation schedules obtained satisfy the basic scheduling requirements of reservoirs.展开更多
In order to improve the thermostability of β- 1,3-1,4-glucanase, evolutionary molecular engineering was used to evolve the β-1,3-1,4-glucanase from Bacillus subtilis ZJF-1A5. The process involves random mutation by ...In order to improve the thermostability of β- 1,3-1,4-glucanase, evolutionary molecular engineering was used to evolve the β-1,3-1,4-glucanase from Bacillus subtilis ZJF-1A5. The process involves random mutation by error-prone PCR and DNA shuffling followed by screening on the filter-based assay. Two mutants, EGsl and EGs2, were found to have four and five amino acid substitutions, respectively. These substitutions resulted in an increase in melting temperature from Tm=62.5℃ for the wild-type enzyme to Tm=65.5℃ for the mutant EGsl and 67.5℃ for the mutant EGs2. However, the two mutated enzymes had opposite approaches to produce reducing sugar from lichenin with either much higher （28%） for the former or much lower （21.6%） for the latter in comparison with their parental enzymes. The results demonstrate that directed evolution is an effective approach to improve the thermostability of a mesophilic enzyme.展开更多
Holding strategies are among the most commonly used operation control strategies. This paper presents an improved holding strategy. In the strategy, a mathematical model aiming to minimize the total waiting times of p...Holding strategies are among the most commonly used operation control strategies. This paper presents an improved holding strategy. In the strategy, a mathematical model aiming to minimize the total waiting times of pas- sengers at the current stop and at the following stops is con- structed and a new heuristic algorithm, shuffled complex evo- lution method developed at the University of Arizona （SCE- UA）, is adopted to optimize the holding times of early buses. Results show that the improved holding strategy can provide better performance compared with a traditional schedule- based holding strategy and no-control strategy. The compu- tational results are also evidence of the feasibility of using SCE-UA in optimizing the holding times of early buses at a stop.展开更多
Hirudin gene was mutated by error\|prone PCR and DNA shuffling.The shuffled genes were inserted into phagemid pCANTAB\|5G8.After the introduction of the recombinant DNA into E.coli TG1,the hirudin mutants were display...Hirudin gene was mutated by error\|prone PCR and DNA shuffling.The shuffled genes were inserted into phagemid pCANTAB\|5G8.After the introduction of the recombinant DNA into E.coli TG1,the hirudin mutants were displayed on the surface of bacteriophage M13.A mutant with increased specific activity of antithrombin was selected by two rounds of panning with decreased amounts of thrombin,and was identified as N47K.Activity analysis of HV2 and its mutants N47K,N26S,D5A,P46L/S50G suggested that K47,P46 were important to the interaction of hirudin and thrombin.Hirudin mutants with improved properties could be hopefully aquired through directed evolution by DNA shuffling.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2016YFC0401702)the Fundamental Research Funds for the Central Universities(Grant No.2018B11214)the National Natural Science Foundation of China(Grants No.51379059 and 51579002)
文摘This paper introduces an optimization method(SCE-SR)that combines shuffled complex evolution(SCE)and stochastic ranking(SR)to solve constrained reservoir scheduling problems,ranking individuals with both objectives and constrains considered.A specialized strategy is used in the evolution process to ensure that the optimal results are feasible individuals.This method is suitable for handling multiple conflicting constraints,and is easy to implement,requiring little parameter tuning.The search properties of the method are ensured through the combination of deterministic and probabilistic approaches.The proposed SCE-SR was tested against hydropower scheduling problems of a single reservoir and a multi-reservoir system,and its performance is compared with that of two classical methods(the dynamic programming and genetic algorithm).The results show that the SCE-SR method is an effective and efficient method for optimizing hydropower generation and locating feasible regions quickly,with sufficient global convergence properties and robustness.The operation schedules obtained satisfy the basic scheduling requirements of reservoirs.
基金Project supported by the National Natural Science Foundation of China (No. 20276064) and Natural Science Foundation of ZhejiangProvince (No. Z304076), China
文摘In order to improve the thermostability of β- 1,3-1,4-glucanase, evolutionary molecular engineering was used to evolve the β-1,3-1,4-glucanase from Bacillus subtilis ZJF-1A5. The process involves random mutation by error-prone PCR and DNA shuffling followed by screening on the filter-based assay. Two mutants, EGsl and EGs2, were found to have four and five amino acid substitutions, respectively. These substitutions resulted in an increase in melting temperature from Tm=62.5℃ for the wild-type enzyme to Tm=65.5℃ for the mutant EGsl and 67.5℃ for the mutant EGs2. However, the two mutated enzymes had opposite approaches to produce reducing sugar from lichenin with either much higher （28%） for the former or much lower （21.6%） for the latter in comparison with their parental enzymes. The results demonstrate that directed evolution is an effective approach to improve the thermostability of a mesophilic enzyme.
文摘Holding strategies are among the most commonly used operation control strategies. This paper presents an improved holding strategy. In the strategy, a mathematical model aiming to minimize the total waiting times of pas- sengers at the current stop and at the following stops is con- structed and a new heuristic algorithm, shuffled complex evo- lution method developed at the University of Arizona （SCE- UA）, is adopted to optimize the holding times of early buses. Results show that the improved holding strategy can provide better performance compared with a traditional schedule- based holding strategy and no-control strategy. The compu- tational results are also evidence of the feasibility of using SCE-UA in optimizing the holding times of early buses at a stop.
文摘Hirudin gene was mutated by error\|prone PCR and DNA shuffling.The shuffled genes were inserted into phagemid pCANTAB\|5G8.After the introduction of the recombinant DNA into E.coli TG1,the hirudin mutants were displayed on the surface of bacteriophage M13.A mutant with increased specific activity of antithrombin was selected by two rounds of panning with decreased amounts of thrombin,and was identified as N47K.Activity analysis of HV2 and its mutants N47K,N26S,D5A,P46L/S50G suggested that K47,P46 were important to the interaction of hirudin and thrombin.Hirudin mutants with improved properties could be hopefully aquired through directed evolution by DNA shuffling.
