研究一类具有 N 车形式的探险问题.该问题要给出 N 辆车的行驶顺序,使得在该顺序下,N 辆车中至少有一辆车的行驶距离最远.通过建立模型,将原 N 车探险问题转化为一个关于 N 辆车的行车顺序的排序问题,该排序问题对应指数时间的复杂度....研究一类具有 N 车形式的探险问题.该问题要给出 N 辆车的行驶顺序,使得在该顺序下,N 辆车中至少有一辆车的行驶距离最远.通过建立模型,将原 N 车探险问题转化为一个关于 N 辆车的行车顺序的排序问题,该排序问题对应指数时间的复杂度.从两车情况入手,给出了两车探险问题的行驶距离最远的判定条件,并推广得到 N 车情况下探险问题的一个特例,给出该问题在特例情况下的有效算法,并证明了该算法可以求得特例的精确最优解.最后给出了计算实例.展开更多
The Coefficient of Variation(CV)of hectometer yarn's weight is one of the guidelines to evaluate its intrinsic quality.In the spinning manufacturing,the control of cotton yarn's weight unevenness is accomplish...The Coefficient of Variation(CV)of hectometer yarn's weight is one of the guidelines to evaluate its intrinsic quality.In the spinning manufacturing,the control of cotton yarn's weight unevenness is accomplished mainly in terms of a spot-check on semi-product and a succedent adjust in process parameters during spinning based on technicians' experience.However,it is theoretically believed among manufacturers that with fixed technical levels and parameters in the spinning process,the quality parameters of assorted cotton have a certain influence on the CV.In order to find out a rule of the influence that assorted cotton has on the CV,a GM(1,N)model,correlated raw cotton's quality parameter with the CV,has firstly been developed according to the modeling theory of grey system,and then been applied in the designing step to predict the CV.It has been approved by practical modeling and validation that the model could fit preferably an accrual CV value,and provide a method of quantitative predicting analysis for textile manufacturers to design cotton yarn's quality.展开更多
This paper is concerned with an optimal harvesting problem over an infinite horizon for age-dependent n-dimensional food chain model and the analysis of long-term behaviors of the optimal-controlled system. The existe...This paper is concerned with an optimal harvesting problem over an infinite horizon for age-dependent n-dimensional food chain model and the analysis of long-term behaviors of the optimal-controlled system. The existence of overtaking optimal policy is proved and a maximum principle is carefully derived by means of Dubovitskii-Milyutin functional analytical extremum theory. Weak and strong turnpike properties of optimal trajectories are established.展开更多
文摘研究一类具有 N 车形式的探险问题.该问题要给出 N 辆车的行驶顺序,使得在该顺序下,N 辆车中至少有一辆车的行驶距离最远.通过建立模型,将原 N 车探险问题转化为一个关于 N 辆车的行车顺序的排序问题,该排序问题对应指数时间的复杂度.从两车情况入手,给出了两车探险问题的行驶距离最远的判定条件,并推广得到 N 车情况下探险问题的一个特例,给出该问题在特例情况下的有效算法,并证明了该算法可以求得特例的精确最优解.最后给出了计算实例.
基金Hunan Provincial Basic Science Foundation of China(No.2007FJ3046)Key Scientific Research Fundof Hunan Provincial Education Department,China(No.07A048)
文摘The Coefficient of Variation(CV)of hectometer yarn's weight is one of the guidelines to evaluate its intrinsic quality.In the spinning manufacturing,the control of cotton yarn's weight unevenness is accomplished mainly in terms of a spot-check on semi-product and a succedent adjust in process parameters during spinning based on technicians' experience.However,it is theoretically believed among manufacturers that with fixed technical levels and parameters in the spinning process,the quality parameters of assorted cotton have a certain influence on the CV.In order to find out a rule of the influence that assorted cotton has on the CV,a GM(1,N)model,correlated raw cotton's quality parameter with the CV,has firstly been developed according to the modeling theory of grey system,and then been applied in the designing step to predict the CV.It has been approved by practical modeling and validation that the model could fit preferably an accrual CV value,and provide a method of quantitative predicting analysis for textile manufacturers to design cotton yarn's quality.
基金Acknowledgments This work is supported by the Nature Science Foundation of China （11061017） and the Nature Science Foundation of Gansu Province of China （1010RJZA075）.
文摘This paper is concerned with an optimal harvesting problem over an infinite horizon for age-dependent n-dimensional food chain model and the analysis of long-term behaviors of the optimal-controlled system. The existence of overtaking optimal policy is proved and a maximum principle is carefully derived by means of Dubovitskii-Milyutin functional analytical extremum theory. Weak and strong turnpike properties of optimal trajectories are established.
