Lean construction has been newly applied to construction industry. The best performance of a project can be achieved through the precise definition of construction product, rational work break structure, lean supply c...Lean construction has been newly applied to construction industry. The best performance of a project can be achieved through the precise definition of construction product, rational work break structure, lean supply chain, decrease of resources waste, objective control and so forth. Referring to the characteristics of schedule planning of construction projects and lean construction philosophy, we proposed optimizing methodology of real-time and dynamic schedule of construction projects based on lean construction. The basis of the methodology is process reorganization and lean supply in construction enterprises. The traditional estimating method of the activity duration is fuzzy and random;however, a newly proposed lean forecasting method employs multi-components linear-regression, back-propagation artificial neural networks and learning curve. Taking account of the limited resources and the fixed duration of a project, the optimizing method of the real-time and dynamic schedule adopts the concept of resource driving. To optimize the schedule of a construction project timely and effectively, an intellectualized schedule management system was developed. It can work out the initial schedule, optimize the real-time and dynamic schedule, and display the schedule with the Gant Chart, the net-work graph and the space-time line chart. A case study was also presented to explain the proposed method.展开更多
The design process for integrated inductors generally requires a geometry optimization step. During this step, many geometries must be simulated and fast and accurate formulae are therefore required for the computatio...The design process for integrated inductors generally requires a geometry optimization step. During this step, many geometries must be simulated and fast and accurate formulae are therefore required for the computation of self and mutual inductances of turns. This paper especially deals with numerical evaluation of the mutual inductance of two coaxial circular wire loops. Several computation methods are presented and compared. Finally, an expression is built-up and proven to be very few computing time consuming and 1% accurate for any kind of geometry. The application of this expression to integrated inductive components modelization is recalled to mind, however, this work gives a general and fast computable solution to the electromagnetic problem.展开更多
Based on the rapid genetic algorithm(RGA),the band gap structures of square lattices with square scatters are optimized.In the optimizing process,gene codes are used to express square scatters and the fitting function...Based on the rapid genetic algorithm(RGA),the band gap structures of square lattices with square scatters are optimized.In the optimizing process,gene codes are used to express square scatters and the fitting function adopts the relative values of the largest absolute photonic band gaps(PBGs).By changing the value of filling factor,three cell forms with large photonic band gaps are obtained.In addition,the comparison between the rapid genetic algorithm and the general genetic algorithm(GGA) is analyzed.展开更多
The combination of batteries and ultracapacitors has become an effective solution to satisfy the requirements of high power density and high energy density for the energy-storage system of electric vehicles.Three aspe...The combination of batteries and ultracapacitors has become an effective solution to satisfy the requirements of high power density and high energy density for the energy-storage system of electric vehicles.Three aspects of such combination efforts were considered for evaluating the four types of hybrid energy-storage system(HESS)topologies.First,a novel optimization framework was proposed and implemented to optimize the voltage level of a battery pack and an ultracapacitor pack for the four types of HESS topologies.During the optimization process,the dynamic programming(DP)algorithm was iteratively applied to determine the optimal control actions.The simulation results with DP were used to evaluate the energy efficiency of different HESS topologies at different voltage levels.Second,the optimized voltage level of the battery and ultracapacitor in each topology indicates that a higher voltage level usually results in a better system performance.The simulation results also illustrate that the optimized rated voltage level of the battery pack is approximately 499.5 V,while for the ultracapacitor pack,the optimized voltage level is at its maximum allowed value.Note that the constraint of the battery voltage is initialized at200–600 V.Third,the control rules for different HESS topologies were obtained through the systematic analysis of the simulation results.In addition,advantages and disadvantages of the four topologies were summarized through evaluation of the efficiency and operating currents of the batteries and the ultracapacitor.展开更多
文摘Lean construction has been newly applied to construction industry. The best performance of a project can be achieved through the precise definition of construction product, rational work break structure, lean supply chain, decrease of resources waste, objective control and so forth. Referring to the characteristics of schedule planning of construction projects and lean construction philosophy, we proposed optimizing methodology of real-time and dynamic schedule of construction projects based on lean construction. The basis of the methodology is process reorganization and lean supply in construction enterprises. The traditional estimating method of the activity duration is fuzzy and random;however, a newly proposed lean forecasting method employs multi-components linear-regression, back-propagation artificial neural networks and learning curve. Taking account of the limited resources and the fixed duration of a project, the optimizing method of the real-time and dynamic schedule adopts the concept of resource driving. To optimize the schedule of a construction project timely and effectively, an intellectualized schedule management system was developed. It can work out the initial schedule, optimize the real-time and dynamic schedule, and display the schedule with the Gant Chart, the net-work graph and the space-time line chart. A case study was also presented to explain the proposed method.
文摘The design process for integrated inductors generally requires a geometry optimization step. During this step, many geometries must be simulated and fast and accurate formulae are therefore required for the computation of self and mutual inductances of turns. This paper especially deals with numerical evaluation of the mutual inductance of two coaxial circular wire loops. Several computation methods are presented and compared. Finally, an expression is built-up and proven to be very few computing time consuming and 1% accurate for any kind of geometry. The application of this expression to integrated inductive components modelization is recalled to mind, however, this work gives a general and fast computable solution to the electromagnetic problem.
基金supported by the Natural Science Collaborating Foundation of Jiaying College and Meizhou Science and Techonolgy Bureau(No. 2009KJ08)
文摘Based on the rapid genetic algorithm(RGA),the band gap structures of square lattices with square scatters are optimized.In the optimizing process,gene codes are used to express square scatters and the fitting function adopts the relative values of the largest absolute photonic band gaps(PBGs).By changing the value of filling factor,three cell forms with large photonic band gaps are obtained.In addition,the comparison between the rapid genetic algorithm and the general genetic algorithm(GGA) is analyzed.
基金supported by the Beijing Institute of Technology Research Fund Program for Young Scholarsthe Excellent Young Scholars Research Fund of Beijing Institute of Technologythe National Science & Technology Pillar Program(Grant No.2013BAG05B00)
文摘The combination of batteries and ultracapacitors has become an effective solution to satisfy the requirements of high power density and high energy density for the energy-storage system of electric vehicles.Three aspects of such combination efforts were considered for evaluating the four types of hybrid energy-storage system(HESS)topologies.First,a novel optimization framework was proposed and implemented to optimize the voltage level of a battery pack and an ultracapacitor pack for the four types of HESS topologies.During the optimization process,the dynamic programming(DP)algorithm was iteratively applied to determine the optimal control actions.The simulation results with DP were used to evaluate the energy efficiency of different HESS topologies at different voltage levels.Second,the optimized voltage level of the battery and ultracapacitor in each topology indicates that a higher voltage level usually results in a better system performance.The simulation results also illustrate that the optimized rated voltage level of the battery pack is approximately 499.5 V,while for the ultracapacitor pack,the optimized voltage level is at its maximum allowed value.Note that the constraint of the battery voltage is initialized at200–600 V.Third,the control rules for different HESS topologies were obtained through the systematic analysis of the simulation results.In addition,advantages and disadvantages of the four topologies were summarized through evaluation of the efficiency and operating currents of the batteries and the ultracapacitor.
