Balancing time,cost,and quality is crucial in intelligent manufacturing.However,finding the optimal value of production parameters is a challengingnon-deterministic polynomial(NP)-hard problem.In the actual production...Balancing time,cost,and quality is crucial in intelligent manufacturing.However,finding the optimal value of production parameters is a challengingnon-deterministic polynomial(NP)-hard problem.In the actual production process,the production process has the characteristics of multi-stage parallel.Therefore,aiming at the difficult problem of multi-stage nonlinear production process optimization,this paper proposes a workflow optimization algorithm based on virtualization and nonlinear production quality under time constraints(T-OVQT).The algorithm proposed in this paper first abstracts the actual production process into a virtual workflow model,which is divided into three layers:The bottom production process collection layer,the middle layer of service node partial order composition layer,and the high level of virtual node collection layer.Then,the virtual technology is used to reconstruct the node set and divide the task interval.The optimal solution is obtained through inverse iterative normalization and forward scheduling,and the global optimal solution is obtained by algorithm integration.Experimental results demonstrate that this algorithm better meets actual production requirements than the traditional minimum critical path(MCP)algorithm.展开更多
We propose a self-organized optimization mechanism to improve the transport capacity of complex gradient networks. We find that, regardless of network topology, the congestion pressure can be strongly reduced by the s...We propose a self-organized optimization mechanism to improve the transport capacity of complex gradient networks. We find that, regardless of network topology, the congestion pressure can be strongly reduced by the self-organized optimization mechanism. Furthermore, the random scale-free topology is more efficient to reduce congestion compared with the random Poisson topology under the optimization mechanism. The reason is that the optimization mechanism introduces the correlations between the gradient field and the local topology of the substrate network. Due to the correlations, the cutoff degree of the gradient network is strongly reduced and the number of the nodes exerting their maximal transport capacity consumedly increases. Our work presents evidence supporting the idea that scale-free networks can efficiently improve their transport capacity by self- organized mechanism under gradient-driven transport mode.展开更多
To deploy sensor nodes over the area of interest,a scheme,named node scattering manipulation,was proposed.It adopted the following method:during node scattering,the initial states of every node,including the velocity ...To deploy sensor nodes over the area of interest,a scheme,named node scattering manipulation,was proposed.It adopted the following method:during node scattering,the initial states of every node,including the velocity and direction,were manipulated so that it would land in a region with a certain probability;every sensor was relocated in order to improve the coverage and connectivity.Simultaneously,to easily analyze the process of scattering sensors,a trajectory model was also proposed.Integrating node scattering manipulation with trajectory model,the node deployment in wireless sensor network was thoroughly renovated,that is,this scheme can scatter sensors.In practice,the scheme was operable compared with the previous achievements.The simulation results demonstrate the superiority and feasibility of the scheme,and also show that the energy consumption for sensors relocation is reduced.展开更多
An Ad hoc network is composed of wireless mobile nodes.Because there is no other wired infrastructure such as base stations,the ad hoc network,unlike other wireless networks such as Wireless Local Area Network(WLAN),h...An Ad hoc network is composed of wireless mobile nodes.Because there is no other wired infrastructure such as base stations,the ad hoc network,unlike other wireless networks such as Wireless Local Area Network(WLAN),has to face attacks from both the control plane and the data plane.Ad hoc should ensure the routing security on the control plane,and the secure forwarding of packets on the data plane.The distributed network protocol should operate safely,and peer-to-peer nodes should have trusting relations for each other.For this purpose,a complete security solution should include three parts:security on the control plane,security on the data plane,and security of key management.展开更多
B. Network Architectures This section describes the main types of industrial and utility communication network topologies and protocols, in preparation for the discussion of specific security issues in the later secti...B. Network Architectures This section describes the main types of industrial and utility communication network topologies and protocols, in preparation for the discussion of specific security issues in the later sections. Communication networks for industrial automation are typically built in hierarchi-展开更多
1. Introduction The installation and administration of large heterogeneous IT infrastructures, for enterprises as well industrial automation systems, are becoming more and more complex and time consuming. The growing ...1. Introduction The installation and administration of large heterogeneous IT infrastructures, for enterprises as well industrial automation systems, are becoming more and more complex and time consuming. The growing number of interconnections between networks, the development of new intelligent IT devices, and increasingly sophisticated computer hard-展开更多
针对机械式穴播器装配线上在制品(Work In Process,WIP)主要依靠管理人员经验进行定性控制的问题,采用多点控制的方法对装配线上在制品进行定量优化。首先运用约束理论(Theory Of Constraint,TOC)结合推、拉两种生产方式对装配线进行分...针对机械式穴播器装配线上在制品(Work In Process,WIP)主要依靠管理人员经验进行定性控制的问题,采用多点控制的方法对装配线上在制品进行定量优化。首先运用约束理论(Theory Of Constraint,TOC)结合推、拉两种生产方式对装配线进行分段研究,在分段节点设立瓶颈缓冲区、并联缓冲区和风险缓冲区;然后根据工位故障持续时间与物料消耗速度计算出缓冲区最优容量,得出机械式穴播器装配线在制品多点控制优化方案。通过对某企业机械式穴播器装配系统进行Flex Sim仿真,验证了方案的可行性。展开更多
基金supported by Heilongjiang Provincial Natural Science Foundation of China(LH2021F030)。
文摘Balancing time,cost,and quality is crucial in intelligent manufacturing.However,finding the optimal value of production parameters is a challengingnon-deterministic polynomial(NP)-hard problem.In the actual production process,the production process has the characteristics of multi-stage parallel.Therefore,aiming at the difficult problem of multi-stage nonlinear production process optimization,this paper proposes a workflow optimization algorithm based on virtualization and nonlinear production quality under time constraints(T-OVQT).The algorithm proposed in this paper first abstracts the actual production process into a virtual workflow model,which is divided into three layers:The bottom production process collection layer,the middle layer of service node partial order composition layer,and the high level of virtual node collection layer.Then,the virtual technology is used to reconstruct the node set and divide the task interval.The optimal solution is obtained through inverse iterative normalization and forward scheduling,and the global optimal solution is obtained by algorithm integration.Experimental results demonstrate that this algorithm better meets actual production requirements than the traditional minimum critical path(MCP)algorithm.
基金Supported by the Education Foundation of Hubei Province under Grant No D20120104
文摘We propose a self-organized optimization mechanism to improve the transport capacity of complex gradient networks. We find that, regardless of network topology, the congestion pressure can be strongly reduced by the self-organized optimization mechanism. Furthermore, the random scale-free topology is more efficient to reduce congestion compared with the random Poisson topology under the optimization mechanism. The reason is that the optimization mechanism introduces the correlations between the gradient field and the local topology of the substrate network. Due to the correlations, the cutoff degree of the gradient network is strongly reduced and the number of the nodes exerting their maximal transport capacity consumedly increases. Our work presents evidence supporting the idea that scale-free networks can efficiently improve their transport capacity by self- organized mechanism under gradient-driven transport mode.
基金Project(2007AA01Z224) supported by National High-Tech Research and Development Program of China
文摘To deploy sensor nodes over the area of interest,a scheme,named node scattering manipulation,was proposed.It adopted the following method:during node scattering,the initial states of every node,including the velocity and direction,were manipulated so that it would land in a region with a certain probability;every sensor was relocated in order to improve the coverage and connectivity.Simultaneously,to easily analyze the process of scattering sensors,a trajectory model was also proposed.Integrating node scattering manipulation with trajectory model,the node deployment in wireless sensor network was thoroughly renovated,that is,this scheme can scatter sensors.In practice,the scheme was operable compared with the previous achievements.The simulation results demonstrate the superiority and feasibility of the scheme,and also show that the energy consumption for sensors relocation is reduced.
基金This work was funded by the National Basic Research Program (973 Program) of China under Grant 2007CB310704.
文摘An Ad hoc network is composed of wireless mobile nodes.Because there is no other wired infrastructure such as base stations,the ad hoc network,unlike other wireless networks such as Wireless Local Area Network(WLAN),has to face attacks from both the control plane and the data plane.Ad hoc should ensure the routing security on the control plane,and the secure forwarding of packets on the data plane.The distributed network protocol should operate safely,and peer-to-peer nodes should have trusting relations for each other.For this purpose,a complete security solution should include three parts:security on the control plane,security on the data plane,and security of key management.
文摘B. Network Architectures This section describes the main types of industrial and utility communication network topologies and protocols, in preparation for the discussion of specific security issues in the later sections. Communication networks for industrial automation are typically built in hierarchi-
文摘1. Introduction The installation and administration of large heterogeneous IT infrastructures, for enterprises as well industrial automation systems, are becoming more and more complex and time consuming. The growing number of interconnections between networks, the development of new intelligent IT devices, and increasingly sophisticated computer hard-
文摘针对机械式穴播器装配线上在制品(Work In Process,WIP)主要依靠管理人员经验进行定性控制的问题,采用多点控制的方法对装配线上在制品进行定量优化。首先运用约束理论(Theory Of Constraint,TOC)结合推、拉两种生产方式对装配线进行分段研究,在分段节点设立瓶颈缓冲区、并联缓冲区和风险缓冲区;然后根据工位故障持续时间与物料消耗速度计算出缓冲区最优容量,得出机械式穴播器装配线在制品多点控制优化方案。通过对某企业机械式穴播器装配系统进行Flex Sim仿真,验证了方案的可行性。
