Friedman＇s plucking model of business fluctuations suggests that output cannot exceed an upper limit, but it is occasionally ＂plucked＂ downward below trends as a result of economic recessions. This paper investigat...Friedman＇s plucking model of business fluctuations suggests that output cannot exceed an upper limit, but it is occasionally ＂plucked＂ downward below trends as a result of economic recessions. This paper investigates China＇s business fluetuations using quarterly real GDP data for the period 1978 2009. Our results show some evidence supporting Friedman＇s plucking model. We find that a ceiling effect of real output exists, and that negative asymmetric shocks significantly affect the transitory component, which captures the plucking downward behavior during the recession. The results also suggest that the basic asymmetric unobserved component model is not appropriate for directly modeling China＇s real output because the business＂ cycle is inaccurately measured, but it works quite well when considering a structural break in the second quarter of 1992. The results reveal that although China＇s economy strengthened in the second quarter of 2009, it is essential for China＇s government to take further positive and effective measures to maintain sustainable development of the economy.展开更多
This paper considers a Geo/Geo/1 queueing system with infinite capacity, in which the service rate changes depending on the workload. Initially, when the number of customers in the system is less than a certain thresh...This paper considers a Geo/Geo/1 queueing system with infinite capacity, in which the service rate changes depending on the workload. Initially, when the number of customers in the system is less than a certain threshold L, low service rate is provided for cost saving. On the other hand, the high service rate is activated as soon as L customers accumulate in the system and such service rate is preserved until the system becomes completely empty even if the number of customers falls below L. The steady-state probability distribution and the expected number of customers in the system are derived. Through the first-step argument, a recursive algorithm for computing the first moment of the conditional sojourn time is obtained. Furthermore, employing the results of regeneration cycle analysis, the direct search method is also implemented to determine the optimal value of L for minimizing the long-run average cost rate function.展开更多
<em>G</em><sub><em>0</em></sub><em>/G</em><sub><em>1</em></sub> “gaps” joint the <em>S</em> phase and<em> M</em> phase ...<em>G</em><sub><em>0</em></sub><em>/G</em><sub><em>1</em></sub> “gaps” joint the <em>S</em> phase and<em> M</em> phase to form the cell cycle. The dynamics of enzyme reaction to drive the target protein production in <em>M</em> phase is analyzed mathematically. Time delay is introduced since the signal transmission need time in <em>G</em><sub><em>0</em></sub><em>/G</em><sub><em>1</em></sub> “gaps” phase. Hopf bifurcation of DDEs model is analyzed by applying geometrical analytical method. The instability oscillating periodic solutions arise as subcritical Hopf bifurcation occurs. The Hysteresis phenomena of the limit cycle are also observed underlying the saddle-node bifurcation of the limit cycle. Due to stability switching, interestingly, the bifurcating periodical solution dies out near the vicinity of Hopf lines. By Lyapunov-Schmidt reduction scheme, the normal form is computed on the center manifold. Finally, it is verified that the theory analytical results are in coincidence with the numerical simulation.展开更多
For the advantages of easy realization and rapidly intelligent response,the one-cycle control was applied in five-phase six-leg switching power amplifier for magnetic bearing.This paper improves the one-cycle control ...For the advantages of easy realization and rapidly intelligent response,the one-cycle control was applied in five-phase six-leg switching power amplifier for magnetic bearing.This paper improves the one-cycle control considering resistance voltage drop and derives its mathematical models.The improved algorithm is compared with the former one.The simulation and experimental results show that the improved algorithm can effectively reduce the output current ripple,achieve good tracking of the given current,improve the control accuracy,and verify the effectiveness and superiority of the method.展开更多
文摘Friedman＇s plucking model of business fluctuations suggests that output cannot exceed an upper limit, but it is occasionally ＂plucked＂ downward below trends as a result of economic recessions. This paper investigates China＇s business fluetuations using quarterly real GDP data for the period 1978 2009. Our results show some evidence supporting Friedman＇s plucking model. We find that a ceiling effect of real output exists, and that negative asymmetric shocks significantly affect the transitory component, which captures the plucking downward behavior during the recession. The results also suggest that the basic asymmetric unobserved component model is not appropriate for directly modeling China＇s real output because the business＂ cycle is inaccurately measured, but it works quite well when considering a structural break in the second quarter of 1992. The results reveal that although China＇s economy strengthened in the second quarter of 2009, it is essential for China＇s government to take further positive and effective measures to maintain sustainable development of the economy.
文摘This paper considers a Geo/Geo/1 queueing system with infinite capacity, in which the service rate changes depending on the workload. Initially, when the number of customers in the system is less than a certain threshold L, low service rate is provided for cost saving. On the other hand, the high service rate is activated as soon as L customers accumulate in the system and such service rate is preserved until the system becomes completely empty even if the number of customers falls below L. The steady-state probability distribution and the expected number of customers in the system are derived. Through the first-step argument, a recursive algorithm for computing the first moment of the conditional sojourn time is obtained. Furthermore, employing the results of regeneration cycle analysis, the direct search method is also implemented to determine the optimal value of L for minimizing the long-run average cost rate function.
文摘<em>G</em><sub><em>0</em></sub><em>/G</em><sub><em>1</em></sub> “gaps” joint the <em>S</em> phase and<em> M</em> phase to form the cell cycle. The dynamics of enzyme reaction to drive the target protein production in <em>M</em> phase is analyzed mathematically. Time delay is introduced since the signal transmission need time in <em>G</em><sub><em>0</em></sub><em>/G</em><sub><em>1</em></sub> “gaps” phase. Hopf bifurcation of DDEs model is analyzed by applying geometrical analytical method. The instability oscillating periodic solutions arise as subcritical Hopf bifurcation occurs. The Hysteresis phenomena of the limit cycle are also observed underlying the saddle-node bifurcation of the limit cycle. Due to stability switching, interestingly, the bifurcating periodical solution dies out near the vicinity of Hopf lines. By Lyapunov-Schmidt reduction scheme, the normal form is computed on the center manifold. Finally, it is verified that the theory analytical results are in coincidence with the numerical simulation.
基金supported by the National Science Foundation of China(No.51607096)。
文摘For the advantages of easy realization and rapidly intelligent response,the one-cycle control was applied in five-phase six-leg switching power amplifier for magnetic bearing.This paper improves the one-cycle control considering resistance voltage drop and derives its mathematical models.The improved algorithm is compared with the former one.The simulation and experimental results show that the improved algorithm can effectively reduce the output current ripple,achieve good tracking of the given current,improve the control accuracy,and verify the effectiveness and superiority of the method.
