Lot scheduling problem with idle time transfer between processes to minimize mean flow time is very important because to minimize mean flow time is to minimize work in process. But the problem is NP hard and no polyn...Lot scheduling problem with idle time transfer between processes to minimize mean flow time is very important because to minimize mean flow time is to minimize work in process. But the problem is NP hard and no polynomial algorithm exists to guarantee optimal solution. Based the analysis the mathematical structure of the problem, the paper presents a new heuristic algorithm. Computer simulation shows that the proposed heuristic algorithm performs well in terms of both quality of solution and execution speed.展开更多
This paper integrated a two-dimensional axisymmetrical transient model applicable to cold-start emission applications. The model can be used to simulate and explain effects of the flow and temperature distribution on ...This paper integrated a two-dimensional axisymmetrical transient model applicable to cold-start emission applications. The model can be used to simulate and explain effects of the flow and temperature distribution on performance of a converter. The evolutions of distribution of the temperature and concentration in the monolith during the cold-start period and the effects of flow distribution in the monolith on the cold-start performance are simulated in terms of the integrated model. The investigation indicates that the axial and radial gradients of temperature of the solid become steeper as the inlet gas temperature ramp increases; this furthermore results in the movement of reaction region in the monolith, and the flow distribution in the monolith affects the radial distribution of temperature of the solid;the radial gradients of temperature of the solid become greater as the flow uniformity index decreases, whereas the light-off time doesn't always increase as the flow uniformity index decreases. The analyses on the distribution of temperature and concentration in the monolith show that the catalytic reaction zone concentrates in central area near the front face. The predicted curves of the velocity distribution have a good agreement with the experimental data.展开更多
The traction motor of electric vehicle is differing from the general industry traction motor completely. Not only frequently start, parking, accelerate, decelerate and low speed, but also high torque in climbing slope...The traction motor of electric vehicle is differing from the general industry traction motor completely. Not only frequently start, parking, accelerate, decelerate and low speed, but also high torque in climbing slope, low torque in high speed and wide range speed are requested. Base on the theory of sound intensi- ty, the experiment of noise are study through the measurement at discrete points. The sizing grid is 10mm × 10mm, The sound intensity map of traction motor are protracted at 1000r/min and the result show that the main noise sources are fan, gear-box and the traction motor in turn.展开更多
This paper extends the single-task n-Vehicle Exploration Problem to Multitask n-Vehicle Exploration Problem （MTNVEP）, by combining n-Vehicle Exploration Problem with Job Scheduling Problem. At first, the authors pro...This paper extends the single-task n-Vehicle Exploration Problem to Multitask n-Vehicle Exploration Problem （MTNVEP）, by combining n-Vehicle Exploration Problem with Job Scheduling Problem. At first, the authors prove that MTNVEP is NP-hard for fixed number of tasks, and it is strongly NP-hard for general number of tasks. Then they propose an improved accurate algorithm with computing time O（n3n）, which is better than O（n!） as n becomes sufficiently large. Moreover, four heuristic algorithms are proposed. Effectiveness of the heuristic algorithms is illustrated by experiments at last.展开更多
文摘Lot scheduling problem with idle time transfer between processes to minimize mean flow time is very important because to minimize mean flow time is to minimize work in process. But the problem is NP hard and no polynomial algorithm exists to guarantee optimal solution. Based the analysis the mathematical structure of the problem, the paper presents a new heuristic algorithm. Computer simulation shows that the proposed heuristic algorithm performs well in terms of both quality of solution and execution speed.
基金PhD Discipline Foundation of Educational Department of China (No. 20010248003).
文摘This paper integrated a two-dimensional axisymmetrical transient model applicable to cold-start emission applications. The model can be used to simulate and explain effects of the flow and temperature distribution on performance of a converter. The evolutions of distribution of the temperature and concentration in the monolith during the cold-start period and the effects of flow distribution in the monolith on the cold-start performance are simulated in terms of the integrated model. The investigation indicates that the axial and radial gradients of temperature of the solid become steeper as the inlet gas temperature ramp increases; this furthermore results in the movement of reaction region in the monolith, and the flow distribution in the monolith affects the radial distribution of temperature of the solid;the radial gradients of temperature of the solid become greater as the flow uniformity index decreases, whereas the light-off time doesn't always increase as the flow uniformity index decreases. The analyses on the distribution of temperature and concentration in the monolith show that the catalytic reaction zone concentrates in central area near the front face. The predicted curves of the velocity distribution have a good agreement with the experimental data.
基金Supported by the National High Technology Research and Development Programme of China （No. 2007AA11A105）, the National Natural Science Foundation of China （ No. 60974063）.
文摘The traction motor of electric vehicle is differing from the general industry traction motor completely. Not only frequently start, parking, accelerate, decelerate and low speed, but also high torque in climbing slope, low torque in high speed and wide range speed are requested. Base on the theory of sound intensi- ty, the experiment of noise are study through the measurement at discrete points. The sizing grid is 10mm × 10mm, The sound intensity map of traction motor are protracted at 1000r/min and the result show that the main noise sources are fan, gear-box and the traction motor in turn.
基金partly supported by Daqing Oilfield Company Project of PetroCHINA under Grant No.dqc- 2010-xdgl-ky-002Key Laboratory of Management,Decision and Information Systems,Chinese Academy of Sciences
文摘This paper extends the single-task n-Vehicle Exploration Problem to Multitask n-Vehicle Exploration Problem （MTNVEP）, by combining n-Vehicle Exploration Problem with Job Scheduling Problem. At first, the authors prove that MTNVEP is NP-hard for fixed number of tasks, and it is strongly NP-hard for general number of tasks. Then they propose an improved accurate algorithm with computing time O（n3n）, which is better than O（n!） as n becomes sufficiently large. Moreover, four heuristic algorithms are proposed. Effectiveness of the heuristic algorithms is illustrated by experiments at last.
