The large scale and complex manufacturing systems have a hierarchical structure where a system is composed several lines with some stations and each station also have several machines and so on. In such a hierarchical...The large scale and complex manufacturing systems have a hierarchical structure where a system is composed several lines with some stations and each station also have several machines and so on. In such a hierarchical structure, the controllers are geographically distributed according to their physical structure. So it is desirable to realize the hierarchical and distributed control. In this paper, a methodology is presented using Petri nets for hierarchical and distributed control. The Petri net representation of discrete event manufacturing processes is decomposed and distributed into the machine controllers, which are coordinated through communication between the coordinator and machine controllers so that the decomposed transitions fire at the same time. Implementation of a hierarchical and distributed control system is described for an example robotic manufacturing system. The demonstrations show that the proposed system can be used as an effective tool for consistent modeling and control of large and complex manufacturing systems.展开更多
This paper aims at developing a novel method of constructing a class of multi-wing chaotic and hyperchaotic system by introducing a unified step function. In order to overcome the essential difficulties in iteratively...This paper aims at developing a novel method of constructing a class of multi-wing chaotic and hyperchaotic system by introducing a unified step function. In order to overcome the essential difficulties in iteratively adjusting multiple parameters of conventional multi-parameter control, this paper introduces a unified step function controlled by a single parameter for constructing various multi-wing chaotic and hyperchaotic systems. In particular, to the best of the authors＇ knowledge, this is also the first time to find a non-equilibrium multi-wing hyperchaotic system by means of the unified step function control. According to the heteroclinic loop Shilnikov theorem, some properties for multi-wing attractors and its chaos mechanism are further discussed and analyzed. A circuit for multi-wing systems is designed and implemented for demonstration, which verifies the effectiveness of the proposed approach.展开更多
随着食品安全问题日益受到重视,危害分析与关键控制点(Hazard Analysis and Critical Control Point,HACCP)体系作为保障食品安全的重要手段,其有效实施与监控显得尤为重要。基于此,本文阐述了HACCP体系的内涵,分析了HACCP体系有效实施...随着食品安全问题日益受到重视,危害分析与关键控制点(Hazard Analysis and Critical Control Point,HACCP)体系作为保障食品安全的重要手段,其有效实施与监控显得尤为重要。基于此,本文阐述了HACCP体系的内涵,分析了HACCP体系有效实施的路径,包括建立前提条件、确定关键控制点、设立监控程序等。同时,分析了HACCP体系在实施监控中存在的问题,如企业重视程度不足、监控手段落后等,并针对这些问题提出了相应的改进建议,旨在为食品企业和监管部门提供一些参考和借鉴,促进食品安全管理水平的提升。展开更多
A system-Asynchronous JavaScript and XML(AJAX)and a Model-View-Controller(MVC)pattern algorithm were proposed for design and implementation of an office automation(OA)system.Adopting the.NET framework as development p...A system-Asynchronous JavaScript and XML(AJAX)and a Model-View-Controller(MVC)pattern algorithm were proposed for design and implementation of an office automation(OA)system.Adopting the.NET framework as development platform,the system modifies the classic MVC pattern,induces AJAX in the ASP.NET 2.0,and includes several modules,namely login,messaging,notice board,personal work,research management,document management,personnel information and maintenance.We discussed the overall structure of the system,functional and database design.The main functions of several modules and their final realization are explained in details.The system yields high efficiency,along with features of clear frame,easy maintainability,reliability,etc.展开更多
The implementation method of the IEEE 802.11 Medium Access Control (MAC) protocol is mainly based on DSP (Digital Signal Processor)/ ARM (Advanced Reduced instruction set computer Machine) processor or DSP/ARM IP (Int...The implementation method of the IEEE 802.11 Medium Access Control (MAC) protocol is mainly based on DSP (Digital Signal Processor)/ ARM (Advanced Reduced instruction set computer Machine) processor or DSP/ARM IP (Intellectual Property) core. This paper presents a method based on Nios II soft-core processor embedded in Altera’s Cyclone FPGA (Field Programmable Gate Array) and MicroC/OS-II RTOS (Real-Time Operation System). The benefits and drawbacks of above methods are compared, and then the method presented in this paper is described. The hardware and software partitioning are discussed; the hardware architecture is also illustrated and the MAC software programming is described in detail. The presented method has some advantages, such as low cost, easy-implementation and very suitable for the implementation of IEEE 802.11 MAC in research stage.展开更多
基金Supported by National Naturai Science Foundation of China （61273104, 61021002, 61104097）, and Projects of Major Interna-tional （Regional） Joint Research Program National Natural Science Foundation of China （61120106010）
文摘The large scale and complex manufacturing systems have a hierarchical structure where a system is composed several lines with some stations and each station also have several machines and so on. In such a hierarchical structure, the controllers are geographically distributed according to their physical structure. So it is desirable to realize the hierarchical and distributed control. In this paper, a methodology is presented using Petri nets for hierarchical and distributed control. The Petri net representation of discrete event manufacturing processes is decomposed and distributed into the machine controllers, which are coordinated through communication between the coordinator and machine controllers so that the decomposed transitions fire at the same time. Implementation of a hierarchical and distributed control system is described for an example robotic manufacturing system. The demonstrations show that the proposed system can be used as an effective tool for consistent modeling and control of large and complex manufacturing systems.
基金Project supported by the National Natural Science Foundation of China(Grant No.61403143)the Natural Science Foundation of Guangdong Province,China(Grant No.2014A030313739)+1 种基金the Science and Technology Foundation Program of Guangzhou City,China(Grant No.201510010124)the Excellent Doctorial Dissertation Foundation of Guangdong Province,China(Grant No.XM080054)
文摘This paper aims at developing a novel method of constructing a class of multi-wing chaotic and hyperchaotic system by introducing a unified step function. In order to overcome the essential difficulties in iteratively adjusting multiple parameters of conventional multi-parameter control, this paper introduces a unified step function controlled by a single parameter for constructing various multi-wing chaotic and hyperchaotic systems. In particular, to the best of the authors＇ knowledge, this is also the first time to find a non-equilibrium multi-wing hyperchaotic system by means of the unified step function control. According to the heteroclinic loop Shilnikov theorem, some properties for multi-wing attractors and its chaos mechanism are further discussed and analyzed. A circuit for multi-wing systems is designed and implemented for demonstration, which verifies the effectiveness of the proposed approach.
文摘随着食品安全问题日益受到重视,危害分析与关键控制点(Hazard Analysis and Critical Control Point,HACCP)体系作为保障食品安全的重要手段,其有效实施与监控显得尤为重要。基于此,本文阐述了HACCP体系的内涵,分析了HACCP体系有效实施的路径,包括建立前提条件、确定关键控制点、设立监控程序等。同时,分析了HACCP体系在实施监控中存在的问题,如企业重视程度不足、监控手段落后等,并针对这些问题提出了相应的改进建议,旨在为食品企业和监管部门提供一些参考和借鉴,促进食品安全管理水平的提升。
基金Shanghai Leading Academic Discipline Project,China(No.J50103)
文摘A system-Asynchronous JavaScript and XML(AJAX)and a Model-View-Controller(MVC)pattern algorithm were proposed for design and implementation of an office automation(OA)system.Adopting the.NET framework as development platform,the system modifies the classic MVC pattern,induces AJAX in the ASP.NET 2.0,and includes several modules,namely login,messaging,notice board,personal work,research management,document management,personnel information and maintenance.We discussed the overall structure of the system,functional and database design.The main functions of several modules and their final realization are explained in details.The system yields high efficiency,along with features of clear frame,easy maintainability,reliability,etc.
文摘The implementation method of the IEEE 802.11 Medium Access Control (MAC) protocol is mainly based on DSP (Digital Signal Processor)/ ARM (Advanced Reduced instruction set computer Machine) processor or DSP/ARM IP (Intellectual Property) core. This paper presents a method based on Nios II soft-core processor embedded in Altera’s Cyclone FPGA (Field Programmable Gate Array) and MicroC/OS-II RTOS (Real-Time Operation System). The benefits and drawbacks of above methods are compared, and then the method presented in this paper is described. The hardware and software partitioning are discussed; the hardware architecture is also illustrated and the MAC software programming is described in detail. The presented method has some advantages, such as low cost, easy-implementation and very suitable for the implementation of IEEE 802.11 MAC in research stage.
