Noise reduction in a shop floor is one of the important parts of greenmanufacturing. In a shop floor machine tools are the main noise sources in a shop floor. A newapproach is discovered by investigation that the nois...Noise reduction in a shop floor is one of the important parts of greenmanufacturing. In a shop floor machine tools are the main noise sources in a shop floor. A newapproach is discovered by investigation that the noise can be obviously reduced in a shop floor byoptimizing the scheduling between work pieces and machine tools. Based on the discovery, a newmethod of noise reduction is proposed. A noise reduction scheduling model in a shop floor isestablished, and the application of the model is also discussed. A case is studied, which shows thatthe method and model are practical.展开更多
Because of an unexpected signal noise within the network or an unpredictedfault with personal computers (PCs), many problems emerge in the implementation of distributednumerical control (DNC) with PCs-based network. T...Because of an unexpected signal noise within the network or an unpredictedfault with personal computers (PCs), many problems emerge in the implementation of distributednumerical control (DNC) with PCs-based network. To solve the problems, an industrial solution ofinvolving the field-bus technology in DNC communicating area is provided. A kind of advancedField-bus, named controller area network (CAN), is originally developed to support cheap and rathersimple automotive applications. However, because of its good performance and low cost, it is alsobeing considered in automated-manufacturing and process control environments to interconnectintelligent devices, such as modem sensors and actuators. Recently it creates a new role for CANBusin DNC that brings new thinking to DNC. CAN is used as the network platform for connecting machinetools to share information with each other reliably. Additionally, thanks to also applying of'plug-in' technology and a special interface of hardware, this solution exhibits some highcompatibility with different pedigree numerical control (NC) systems, such as Fanuc, Siemens,Cincinnati and so on. In order to improve CANBus for DNC application, a communicating competitionmodel of the basic CAN protocol, called CC model, is then highlighted. This model is able to satisfythe requirements that different machine tools share the communicating bandwidth fairly when theyrun concurrently. Finally the novel view of the latest advancement in CANBus-based DNC incombination with the manufacturing paradigm is also presented.展开更多
Based on the definition of passivity extended from deterministic system, the sufficient condition on passivity of stochastic jump system is given against unknown state time delay. By means of memoryless state feedback...Based on the definition of passivity extended from deterministic system, the sufficient condition on passivity of stochastic jump system is given against unknown state time delay. By means of memoryless state feedback, a class of state delayed stochastic jump systems may be led to passive. The feedback controllers are mode-dependent and can be constructed in terms of the solutions of a set of coupled linear matrix inequalities. A numerical example illustrates the results.展开更多
Objective: to explore the impact of the flipped interactive teaching mode of rain classroom live broadcast on the teaching quality in psychiatric nursing teaching. Methods: a total of 60 nursing students were enrolled...Objective: to explore the impact of the flipped interactive teaching mode of rain classroom live broadcast on the teaching quality in psychiatric nursing teaching. Methods: a total of 60 nursing students were enrolled in this study from February to October 2019. Randomly divided into groups, 30 cases in each group. The control group chose conventional mode to carry out rain classroom live broadcast online teaching, while the observation group chose rain classroom live broadcast combined with flipped interactive teaching mode to compare the application effects of different teaching modes and students' evaluation of the teaching mode. Results: the scores of the two groups were higher in the observation group than in the control group (P < 0.05). There was a significant difference in students' satisfaction with the teaching mode between the two groups, and the observation group was relatively higher (P < 0.05). There were significant differences between the two groups in single video learning duration, clicks and number of effective bullet screen in class, and the mean values of observation group were higher than those of control group (P < 0.05). Conclusion: in online teaching of psychiatric nursing, the flipped interactive teaching mode of rain classroom live broadcast can obtain ideal application effect. On the one hand, it can enhance students' participation in learning and strengthen teaching quality. Students give high evaluation to the teaching mode, which has the value of promotion and application.展开更多
Generalized H2 control problem is considered for a class of linear time-delay systems covering linear timeinvariant (LTI) case and time-varying but norm-bounded linear differential inclusion (NLDI) case. The issues fo...Generalized H2 control problem is considered for a class of linear time-delay systems covering linear timeinvariant (LTI) case and time-varying but norm-bounded linear differential inclusion (NLDI) case. The issues focus on the synthesis of so-called generalized H2 controller, which guarantees internal/robust stability and a certain performance level of generalized H2 norm of resulting closed-loop system. By using Lyapunov functional technique, sufficient conditions for the existence of such a kind of controllers are obtained in terms of two linear matrix inequalities (LMIs). In the state space, for memoryless state feedback case, we treat the controller design in a unified framework for both LTI and NLDI. The presented results are illustrated by numerical examples.展开更多
文摘Noise reduction in a shop floor is one of the important parts of greenmanufacturing. In a shop floor machine tools are the main noise sources in a shop floor. A newapproach is discovered by investigation that the noise can be obviously reduced in a shop floor byoptimizing the scheduling between work pieces and machine tools. Based on the discovery, a newmethod of noise reduction is proposed. A noise reduction scheduling model in a shop floor isestablished, and the application of the model is also discussed. A case is studied, which shows thatthe method and model are practical.
基金Science and Technology Program Foundation of Chongqing(No.7210)
文摘Because of an unexpected signal noise within the network or an unpredictedfault with personal computers (PCs), many problems emerge in the implementation of distributednumerical control (DNC) with PCs-based network. To solve the problems, an industrial solution ofinvolving the field-bus technology in DNC communicating area is provided. A kind of advancedField-bus, named controller area network (CAN), is originally developed to support cheap and rathersimple automotive applications. However, because of its good performance and low cost, it is alsobeing considered in automated-manufacturing and process control environments to interconnectintelligent devices, such as modem sensors and actuators. Recently it creates a new role for CANBusin DNC that brings new thinking to DNC. CAN is used as the network platform for connecting machinetools to share information with each other reliably. Additionally, thanks to also applying of'plug-in' technology and a special interface of hardware, this solution exhibits some highcompatibility with different pedigree numerical control (NC) systems, such as Fanuc, Siemens,Cincinnati and so on. In order to improve CANBus for DNC application, a communicating competitionmodel of the basic CAN protocol, called CC model, is then highlighted. This model is able to satisfythe requirements that different machine tools share the communicating bandwidth fairly when theyrun concurrently. Finally the novel view of the latest advancement in CANBus-based DNC incombination with the manufacturing paradigm is also presented.
文摘Based on the definition of passivity extended from deterministic system, the sufficient condition on passivity of stochastic jump system is given against unknown state time delay. By means of memoryless state feedback, a class of state delayed stochastic jump systems may be led to passive. The feedback controllers are mode-dependent and can be constructed in terms of the solutions of a set of coupled linear matrix inequalities. A numerical example illustrates the results.
文摘Objective: to explore the impact of the flipped interactive teaching mode of rain classroom live broadcast on the teaching quality in psychiatric nursing teaching. Methods: a total of 60 nursing students were enrolled in this study from February to October 2019. Randomly divided into groups, 30 cases in each group. The control group chose conventional mode to carry out rain classroom live broadcast online teaching, while the observation group chose rain classroom live broadcast combined with flipped interactive teaching mode to compare the application effects of different teaching modes and students' evaluation of the teaching mode. Results: the scores of the two groups were higher in the observation group than in the control group (P < 0.05). There was a significant difference in students' satisfaction with the teaching mode between the two groups, and the observation group was relatively higher (P < 0.05). There were significant differences between the two groups in single video learning duration, clicks and number of effective bullet screen in class, and the mean values of observation group were higher than those of control group (P < 0.05). Conclusion: in online teaching of psychiatric nursing, the flipped interactive teaching mode of rain classroom live broadcast can obtain ideal application effect. On the one hand, it can enhance students' participation in learning and strengthen teaching quality. Students give high evaluation to the teaching mode, which has the value of promotion and application.
文摘Generalized H2 control problem is considered for a class of linear time-delay systems covering linear timeinvariant (LTI) case and time-varying but norm-bounded linear differential inclusion (NLDI) case. The issues focus on the synthesis of so-called generalized H2 controller, which guarantees internal/robust stability and a certain performance level of generalized H2 norm of resulting closed-loop system. By using Lyapunov functional technique, sufficient conditions for the existence of such a kind of controllers are obtained in terms of two linear matrix inequalities (LMIs). In the state space, for memoryless state feedback case, we treat the controller design in a unified framework for both LTI and NLDI. The presented results are illustrated by numerical examples.
