In this study, we propose a new temperature compensation control strategy for a multi-cavity hot runner injection molding system, At first, the melt filling time of each cavity can be measured by installing temperatur...In this study, we propose a new temperature compensation control strategy for a multi-cavity hot runner injection molding system, At first, the melt filling time of each cavity can be measured by installing temperature sensors on the position around end filling area, and filling time difference between the various cavities can be calculated. Then the melt temperature of each hot nozzle can be adjusted automatically by a control strategy established based on the Fuzzy Theory and a program compiled with LABVIEW software. Temperature changes the melt mobility, so the adjustment of temperature can equalize the filling time of the melt in each cavity, which can reduced the mass deviation between each cavity and make product properties of each cavity consistent. The conclusion of the experiment is as follows： For this contact lens box of a four-cavity Hot Runner mold, by applying hot runner temperature compensation control system, time difference can be reduced from 0.05 s to 0.01 s at each cavity, and the mass Standard deviation of the four cavity can be improved from 0.006 to 0.002. The ratio of imbalance can be reduced from 20% to 4%. Hence, the hot runner temperature compensation control system has significant feasibility and high potential in improving melt flow balance of multi-cavity molding application.展开更多
This paper studies an M/M/1 queueing-inventory system with batch demands. Customers arrive in the system according to a compound Poisson process, where the size of the batch demands for each arrival is a random variab...This paper studies an M/M/1 queueing-inventory system with batch demands. Customers arrive in the system according to a compound Poisson process, where the size of the batch demands for each arrival is a random variable that follows a geometric distribution. The inventory is replenished according to the standard （s, S） policy. The replenishment time follows an exponential distribution. Two models are considered. In the first model, if the on-hand inventory is less than the size of the batch demands of an arrived customer, the customer takes away all the items in the inventory, and a part of the customer＇s batch demands is lost. In the second model, if the on-hand inventory is less than the size of the batch demands of an arrived customer, the customer leaves without taking any item from the inventory, and all of the customer＇s batch demands are lost. For these two models, the authors derive the stationary conditions of the system. Then, the authors derive the stationary distributions of the product-form of the joint queue length and the on-hand inventory process. Besides this, the authors obtain some important performance measures and the average cost functions by using these stationary distributions. The results are illustrated by numerical examples.展开更多
This paper presents an infeasible-interior-point algorithm for aclass of nonmonotone complementarity problems, and analyses its convergence and computational complexity. The results indicate that the proposed algorith...This paper presents an infeasible-interior-point algorithm for aclass of nonmonotone complementarity problems, and analyses its convergence and computational complexity. The results indicate that the proposed algorithm is a polynomial-time one.展开更多
An M/G/1 retrial queue with a first-come-first-served (FCFS) orbit,general retrial time,two-phase service and server breakdown is investigated in this paper.Customers are allowed to balkand renege at particular times....An M/G/1 retrial queue with a first-come-first-served (FCFS) orbit,general retrial time,two-phase service and server breakdown is investigated in this paper.Customers are allowed to balkand renege at particular times.Assume that the customers who find the server busy are queued inthe orbit in accordance with an FCFS discipline.All customers demand the first 'essential' service,whereas only some of them demand the second 'optional' service,and the second service is multi-optional.During the service,the server is subject to breakdown and repair.Assume that the retrialtime,the service time,and the repair time of the server are all arbitrarily distributed.By using thesupplementary variables method,the authors obtain the steady-state solutions for both queueing andreliability measures of interest.展开更多
文摘In this study, we propose a new temperature compensation control strategy for a multi-cavity hot runner injection molding system, At first, the melt filling time of each cavity can be measured by installing temperature sensors on the position around end filling area, and filling time difference between the various cavities can be calculated. Then the melt temperature of each hot nozzle can be adjusted automatically by a control strategy established based on the Fuzzy Theory and a program compiled with LABVIEW software. Temperature changes the melt mobility, so the adjustment of temperature can equalize the filling time of the melt in each cavity, which can reduced the mass deviation between each cavity and make product properties of each cavity consistent. The conclusion of the experiment is as follows： For this contact lens box of a four-cavity Hot Runner mold, by applying hot runner temperature compensation control system, time difference can be reduced from 0.05 s to 0.01 s at each cavity, and the mass Standard deviation of the four cavity can be improved from 0.006 to 0.002. The ratio of imbalance can be reduced from 20% to 4%. Hence, the hot runner temperature compensation control system has significant feasibility and high potential in improving melt flow balance of multi-cavity molding application.
基金supported in part by the Natural Science Foundation of Hebei Province,China under Grant No.A2017203078Natural Science Research Project of the Education Department of Henan Province,China under Grant No.2011C110002
文摘This paper studies an M/M/1 queueing-inventory system with batch demands. Customers arrive in the system according to a compound Poisson process, where the size of the batch demands for each arrival is a random variable that follows a geometric distribution. The inventory is replenished according to the standard （s, S） policy. The replenishment time follows an exponential distribution. Two models are considered. In the first model, if the on-hand inventory is less than the size of the batch demands of an arrived customer, the customer takes away all the items in the inventory, and a part of the customer＇s batch demands is lost. In the second model, if the on-hand inventory is less than the size of the batch demands of an arrived customer, the customer leaves without taking any item from the inventory, and all of the customer＇s batch demands are lost. For these two models, the authors derive the stationary conditions of the system. Then, the authors derive the stationary distributions of the product-form of the joint queue length and the on-hand inventory process. Besides this, the authors obtain some important performance measures and the average cost functions by using these stationary distributions. The results are illustrated by numerical examples.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 19971065) .
文摘This paper presents an infeasible-interior-point algorithm for aclass of nonmonotone complementarity problems, and analyses its convergence and computational complexity. The results indicate that the proposed algorithm is a polynomial-time one.
基金supported by the National Natural Science Foundation of China under Grant No. 10871020
文摘An M/G/1 retrial queue with a first-come-first-served (FCFS) orbit,general retrial time,two-phase service and server breakdown is investigated in this paper.Customers are allowed to balkand renege at particular times.Assume that the customers who find the server busy are queued inthe orbit in accordance with an FCFS discipline.All customers demand the first 'essential' service,whereas only some of them demand the second 'optional' service,and the second service is multi-optional.During the service,the server is subject to breakdown and repair.Assume that the retrialtime,the service time,and the repair time of the server are all arbitrarily distributed.By using thesupplementary variables method,the authors obtain the steady-state solutions for both queueing andreliability measures of interest.
