WDM网络中一种支持优先级的波长分配算法

有效的算法能大大的提高波长利用率,文中研究了WDM光网络在固定路由无波长转换条件下的波长分配算法,以便充分挖掘WDM网络的带宽资源。提出了一种基于RLI并考虑通道优先级的波长分配算法,并给出了该算法的具体实现步骤。最后的仿真结果表明,与RLI算法相比该算法显著的降低了网络的阻塞率,有利于提高网络资源的利用率。     

Integrated procedure of balancing and sequencing for mixed-model assembly lines: a multi-objective evolutionary approach

A mixed-model assembly line is a type of production line which is used to assemble a variety of product models with a certain level of similarity in operational characteristics. This variety causes workload variance among other problems resulting in low efficiency and line stops. To cope with these problems, a hierarchical design procedure for line balancing and model sequencing is proposed. It is structured in terms of an amelioration procedure. On the basis of our evolutionary algorithm, a genetic encoding procedure entitled priority-based multi-chromosome (PMC) is proposed. It features a multi-functional chromosome and provides efficient representation of task assignment to workstations and model sequencing. The lean production perspective recognises the U-shape assembly line system as more advanced and beneficial compared to the traditional straight line system. To assure the effectiveness of the proposed procedure, both straight and U-shape assembly lines are examined under two major performance criteria, i.e., number of workstations (or line efficiency) as static criterion and variance of workload (line and models) as dynamic criterion. The results of simulation experiments suggest that the proposed procedure is an effective management tool of a mixed-model assembly line system.     

一种新的GEO/LEO双层星座路由算法

针对多层卫星星座网络的复杂通信环境和特殊应用背景,提出一种新的基于优先级的星上分布式路由算法( PDRA)。 PDRA算法采用新的分层管理策略,根据信息重要程度设置优先级,在拓扑快照起始时刻进行路由计算与更新,信息传输过程中采用拥塞回避策略。理论分析和仿真验证表明,PDRA算法与现有典型卫星星座网络路由算法相比性能优越,能够很好地利用GEO/LEO双层星座特点,有较低的数据丢包率和较高的吞吐量,可有效避免链路拥塞,并能保证重要信息实时可靠传输。     

IoT-based networking for humanoid robots

Abstract

In this paper, a new network communication approach, named real-time network (RTNET), is designed and implemented for humanoid robots. The proposed five network objects – alarm, condition, message, mail, and file are used to represent the task and priority of the communication data. Compared to the existing protocols, the network scheduling mechanism of RTNET arranges, more efficiently, the priority and flow control of the five network communication objects to meet real-time requirements for the limited bandwidth of the local area network. RTNET can be further integrated with other protocols, such as EtherCAT or controller area networks (CAN Bus) for local control systems, e.g. robot arms, to improve the communication mechanism. The RTNET can also be used over Ethernet to connect each subsystem and to exchange information among those systems. Also, an Internet of things (IoT) network structure based on RTNET is proposed in this paper. The information of each subsystems is collected through RTNET and users can access all components in the IoT network. In this paper, the concept of RTNET is presented and RTNET has been implemented on a National Taiwan University (NTU) humanoid robot control system with CAN Bus.     

总线控制网络中基于优先级CSMA/CD协议的改进

总线控制网络的MAC层协议对网络实时特性具有重要影响。结合优先级CSMA／CD协议的等级原则与Token Bus协议的均衡思想，提出了一种改进的总线优先级轮循CSMA／CD协议。其高级别的总线优先级类似于Token Bus协议中的令牌，在各节点之间轮循传递；使控制网络在遵循整体分级的原则下，相同类型节点的性能局部能够相对均衡。详细阐明了该改进基本思想，概述其具体实现方式，并给出了对比仿真结果。该改进协议对于CAN等基于优先级CSMA／CD协议的总线控制网络具有一定实用价值。     

一种新的WDM网状网中的动态子通路保护算法

论文研究了业务量疏导WDM网状网中的生存性问题,提出一种新的基于优先级的自适用子通路保护算法(PASPP)。该算法在为子通路寻找保护通路时,高优先级业务可以通过抢占低优先级的业务保护通路来提高其连通率,而同时对低优先级业务也能提供部分保护。仿真结果表明,该算法有较好的性能。     

A Scalable Priority-Based Multi-Path Routing Protocol for Wireless Sensor Networks

In this paper, a scalable priority-based multi-path routing protocol (PRIMP) is proposed for wireless sensor networks to offer extended network lifetime and robust network fault tolerance, under the context of stringent energy constraint and vulnerability of sensors to dynamic environmental conditions. A novel interest dissemination strategy which invokes an on-demand virtual source technique is designed in PRIMP to minimize communication overheads and energy wastage. In routing, data traffic is distributed over multiple braided data paths simultaneously by a priority-based probabilistic approach at each hop to achieve the robustness against the unreliable transmission due to frequent node failures. Extensive simulations validate that PRIMP exhibits significantly better performance in energy conservation, load-balancing and data delivery than comparable schemes, while at the same time PRIMP achieves a nice scalability feature in terms of energy dissipation with various network sizes and network densities. Last but not least, PRIMP addresses the slow startup problem that is prevalent in data-centric routing schemes.     

统计优先级多址接入协议的改进与仿真

统计优先级的多址接入（Statistical Priority-based Multiple Access,SPMA）协议的优良性能符合未来数据链的发展趋势。经典的SPMA协议中存在固定门限设置导致的吞吐量下降、退避时间设置过于简单和低优先级分组“饥饿”等三个问题。针对这些问题,提出了统计差值退避算法和虚拟时间戳排队算法。统计差值退避算法使用负载统计量和优先级门限的差值,计算出合理的分组退避时间。虚拟时间戳排队算法根据接入带宽的最低要求,按照虚拟完成时间大小进行分组接入。结合这两个算法,设计了基于SPMA的介质访问控制层改进协议,并使用OPNET软件对改进协议进行了仿真。仿真结果表明,相比于SPMA协议的传统算法,改进协议的系统吞吐量更大且更稳定,优先级平均时延更低,同时保证了低优先级业务的最小带宽接入需求。