基于等效电路模型的Mesh结构P/G网布线优化方法

本文在对供电用串联电阻链的等效电路模型进行详细论证的基础上，根据Mesh结构P／G网所具有的结构特点，将P／G网电阻网络加以等效变换，得到比原网络规模小得多的等效简化网络。然后用现有的布线优化方法来优化简化网络，速度可提高至少一个数量级。     

Mesh结构P/G布线网络层次化快速分析方法

本文提出了一个基于网络划分的P／G布线网络层次化快速分析方法。其中，对于子网运算，通过对Cholesky分解法三角化对称正定阵的图模型分析，并基于Mesh结构网络的自身特点，提出了一个基于图顶点排序的加速子网分析运算策略；并用基于MPI的并行结构实现了P／G布线网络分析的并行运算。     

LSI版图设计中的一种P／G网布线法

本文提出了一种有效的P/G网布线算法和在积木块式布图系统中实现的策略。与以往算法比较,此算法允许每条电源网具有多个馈电脚存在。其策略包括四个部分:(1)一种有效的层次式自上而下的P/G网平面性分析和拓扑路径分配算法;(2)P/G网线宽的确定;(3)总体压缩和再布线后P/G网布线信息的动态修改;(4)与信号网一起的平面性无网格电源网通道详细嵌入。实验结果表明我们的P/G网布线方法可获得令人满意的布线结果。     

VLSI版图综合中的P／G网实体优化布线

本文提出了一种在通道内将Ｐ／Ｇ网与信号网的实体布线一体化考虑的优化布线策略，目的是在保证１００％布通的前提下，完成Ｐ／Ｇ网的平面化实体嵌入和信号网的实体布线，并使Ｐ／Ｇ走线对信号网走线的影响尽可能小。算法以提高布线区利用率、减小通道高度和减少通孔数为目标，实现总体性能的优化。系统实现的结果表明，本文算法所采用的策略是可行的、有效的。     

TEOS等离子CVD膜形成中加氟气体的效果

一、前言用LSI多层布线技术的器件表面台阶形状越来越趋于复杂化、高纵横尺寸比化。因此，面对层间绝缘膜的要求，如何消除高纵横尺寸比布线间的掩埋和布线台阶问题，一年比一年要求严格，而使网复杂的层间绝缘膜成膜。本义介绍的内容就是上述的掩埋工艺技术。以往，人们都使用具有叠层结构的工艺，而这种叠层结构是由等离子TEOS／SOG／等离子TEOS或者等离于TEOS／臭氧TEOS／等离子TEOS等组合而成的。但是，到了亚微米时代，即使用以上那样的工艺亦可得到布线间的优良的膜质，而且能防止产生间隙，么是一个难题。由于间隙的存在…     

Cisco扩展千兆位和布线室解决方案

CiscoSystems公司近日推出两个适用于布线室的CiscoCatalyst智能解决方案系列新成员：Catalyst400O和Catalyst2948G。这两个新平台使用与Catalyst5500系列相同的软件，扩展了Catalyst解决方案提供的投资保护，帮助网络管理人员降低了总体拥有成本。Catalyst系列的这两个新成员是模块结构的Catalyst4003和固定配置的Catalyst2849G。这些新解决方案是专为满足从48到96端口的10／IO0或高密度千兆位的布线室需求而设计的，它以可实现高性能10／100／1000Mbps以太网连接性的无阻塞交换体系结构为基础。Cisco同时也宣布了对Catalyst5500所…     

分场景2G／3G互操作与功率参数优化

互操作优化目标就是把2G／3G网络有效结合起来,针对现网具体情况,我们将全网小区按照覆盖场景不同进行划分,对不同厂商设备规定统一标准的互操作参数及功率参数,从而保证2G／3G互操作的规范性、准确性,同时提升优化工作效率。实践证明,经过分场景2G／3G互操作与功率参数优化后,切换成功率、掉话率等指标有较大提高,客户感知也得到提升。     

时延驱动的整平面整体布线算法

本文结出了一个新的时延驱动的整体布线算法．算法采用了整平面布线技术，从而具有快速求解的特点且无网序问题的困扰．算法优化的目标是使所有线网的最大时延之和最小，尤其是在关键路径上的线网实际电路的布线结果表明该算法可有效地改善关键路径上线网的时延．     

基于DeviceNet的PowerFlex40变频器在无尘纸生产系统中的应用

本文设计了三层网络无尘纸生产控制系统，重点介绍PowerFlex40变频器一卡多机通讯对DeviceNet网络的优化，并给出DeviceNet变频器设备网软硬件实现方法。采用最少的硬件设备和简单布线实现了系统控制要求，大大降低了硬件成本，优化了网络结构，提高了系统性能。[第一段]     

2G／3G互操作方案思考

文章介绍了中国联通2G网元进行2G／3G互操作的功能需求描述,使现有的GSM／GPRS网设备具备2G／3G互操作功能,从而保证3G用户在GSM／GPRS网和WCDMA网中的业务使用连续性。     

无线Mesh网络可靠多播路由

无线Mesh网络多播路由是无线路由必须解决的关键技术。部分研究者对网络资源和服务质量（QoS）进行研究,提出了建立最短路径树、最小开销树、负载感知、信道分配多播等多播算法;有的算法考虑链路可靠性,建立备用路径。将结合网络资源和可靠性对多播路由算法进行研究,提出了建立可靠多播树（RT,Reliable Tree）的多播路由算法：可靠多播树是一个多树结构,由一棵首选多播树和一棵多径树构成,多径树提供可靠多路径,以提高网络吞吐量。     

The core-assisted mesh protocol

The core-assisted mesh protocol (CAMP) is introduced for multicast routing in ad hoc networks. CAMP generalizes the notion of core-based trees introduced for internet multicasting into multicast meshes that have much richer connectivity than trees. A shared multicast mesh is defined for each multicast group; the main goal of using such meshes is to maintain the connectivity of multicast groups even while network routers move frequently, CAMP consists of the maintenance of multicast meshes and loop-free packet forwarding over such meshes. Within the multicast mesh of a group, packets from any source in the group are forwarded along the reverse shortest path to the source, just as in traditional multicast protocols based on source-based trees. CAMP guarantees that within a finite time, every receiver of a multicast group has a reverse shortest path to each source of the multicast group. Multicast packets for a group are forwarded along the shortest paths front sources to receivers defined within the group's mesh. CAMP uses cores only to limit the traffic needed for a router to join a multicast group; the failure of cores does not stop packet forwarding or the process of maintaining the multicast meshes     

Surface trees – Representation of boundary surfaces using a tree descriptor

Many applications in fields as diverse as computer graphics, medical imaging or pattern recognition require the usage of the boundary of digital objects, or discrete surface. A discrete surface is a set of orthogonal quadrilaterals connected to each other that is typically represented either as a face adjacency graph or as a polygon mesh. In this work we propose a new method, named surface trees, to represent discrete surfaces. Surface trees allow the representation of any discrete surface by coding a tree structure contained in the face adjacency graph. This method uses an alphabet of nine symbols, in addition to the parenthesis notation, to codify trees of maximum degree four. Surface trees are a compact way of representing any discrete surface at the same time they preserve geometrical information and provide invariance under translation and rotation. We demonstrate our method on synthetic surfaces as well as others obtained from real data.     

The Shuffled Mesh: a flexible and efficient model for parallel computing

In this work an efficient model for parallel computing, called Shuffled Mesh (SM), is introduced. This bounded degree model has the mesh as subgraph and it is based on the union of mesh and shuffle‐exchange topologies. It is shown that an N‐processor SM combines the features of mesh, shuffle‐exchange, hypercubic networks, mesh of trees and hypercube, and is able to support all the algorithms designed for such topologies with constant or logarithmic time performance degradation. Finally, it is proved that the VLSI layout of a SM is the same as of a shuffle exchange of the same size. This revised version was published online in June 2006 with corrections to the Cover Date.     

Adaptive multicast on mobile ad hoc networks using tree-based meshes with variable density of redundant paths

Multicasting has been extensively studied for mobile ad hoc networks (MANETs) because it is fundamental to many ad hoc network applications requiring close collaboration of multiple nodes in a group. A general approach is to construct an overlay structure such as multicast tree or mesh and to deliver a multicast packet to multiple receivers over the overlay structure. However, it either incurs a lot of overhead (multicast mesh) or performs poorly in terms of delivery ratio (multicast tree). This paper proposes an adaptive multicast scheme, called tree-based mesh with k-hop redundant paths (TBM _k ), which constructs a multicast tree and adds some additional links/nodes to the multicast structure as needed to support redundancy. It is designed to make a prudent tradeoff between the overhead and the delivery efficiency by adaptively controlling the path redundancy depending on network traffic and mobility. In other words, when the network is unstable with high traffic and high mobility, a large k is chosen to provide more robust delivery of multicast packets. On the other hand, when the network traffic and the mobility are low, a small k is chosen to reduce the overhead. It is observed via simulation that TBM _k improves the packet delivery ratio as much as 35% compared to the multicast tree approach. On the other hand, it reduces control overhead by 23–87% depending on the value of k compared to the multicast mesh approach. In general, TBM _k with the small value of k offers more robust delivery mechanism but demands less overhead than multicast trees and multicast meshes, respectively.     

A novel approach for multicast call acceptance in multi-channel multi-radio wireless mesh networks

Multicasting is an efficient data transmission approach for group communication applications in multi-channel multi-radio wireless mesh networks. In this paper we have studied the problem of accepting on-line multicast requests, which is quite important for supporting multimedia applications. Our proposed algorithm investigates the acceptance of an arrived call in two phases. In the first phase, a loop-free mesh backbone is constructed. In this mesh, the set of possible parents of each node is limited to the neighbors that are one hop closer to the source node. The neighbors with the same distance from the source node are also acceptable under the circumstance that two neighboring nodes cannot be the possible parents of each other. Next, a sub-optimal mathematical model has been proposed for tree construction over the obtained mesh. The derived multicast trees utilize the minimum amount of bandwidth; are load-balanced; and exploit wireless broadcast advantage. The results show that the proposed algorithm improves the rate of multicast call acceptance by 40% on average compared to previous algorithms in a short running time.     

Scalable Multicasting: The Core-Assisted Mesh Protocol

Most of the multicast routing protocols for ad hoc networks today are based on shared or source-based trees; however, keeping a routing tree connected for the purpose of data forwarding may lead to a substantial network overhead. A different approach to multicast routing consists of building a shared mesh for each multicast group. In multicast meshes, data packets can be accepted from any router, as opposed to trees where data packets are only accepted from routers with whom a tree branch has been established. The difference among multicast routing protocols based on meshes is in the method used to build these structures. Some mesh-based protocols require the flooding of sender or receiver announcements over the whole network. This paper presents the Core-Assisted Mesh Protocol, which uses meshes for data forwarding, and avoids flooding by generalizing the notion of core-based trees introduced for internet multicasting. Group members form the mesh of a group by sending join requests to a set of cores. Simulation experiments show that meshes can be used effectively as multicast routing structures without the need for flooding control packets.     

Progressive transmission of single-resolution mesh image

A concept to simplify a triangle mesh image through its triangle list is introduced. On this basis, a single-resolution mesh data structure, which supports mesh image progressive transmission, is constructed, and the construction approach is considerably simple and applicable to arbitrary triangle mesh image.     

Theoretical underpinnings for the efficiency of restorable networksusing preconfigured cycles (“p-cycles”)

Previous work on restorable networks has shown experimentally that one can support 100% restoration with an optimized set of closed cycles of spare capacity while requiring little or no increase in spare capacity relative to a span-restorable mesh network. This is important and unexpected because it implies that future restoration schemes could be as capacity efficient as a mesh network, while being as fast as ring-based networks because there is no real-time work at any nodes other than the two failure nodes. This paper complements the prior work by giving a greater theoretical basis and insight to support the prior results. We are able to show in a bounding-type of argument that the proposed protection cycles (“p-cycles”) have as high a restoration efficiency as it is possible to expect for any type of preconfigured pattern, and are categorically superior to preconfigured linear segments or trees. We are also able to show that the capacity efficiency of a fully preconfigured p-cycle network has the same well-known lower bound as that of a span restorable mesh network which is cross-connected on-demand. These results provide a theoretical underpinning for the efficiency of p-cycles and confirmation of the experimental observations     

Semi-regular representation and progressive compression of 3-D dynamic mesh sequences.

We propose an algorithm that represents three-dimensional dynamic objects with a semi-regular mesh sequence and compresses the sequence using the spatiotemporal wavelet transform. Given an irregular mesh sequence, we construct a semi-regular mesh structure for the first frame and then map it to subsequent frames based on the hierarchical motion estimation. The regular structure of the resulting mesh sequence facilitates the application of advanced coding schemes and other signal processing techniques. To encode the mesh sequence compactly, we develop an embedded coding scheme, which supports signal-to-noise ratio and temporal scalability modes. Simulation results demonstrate that the proposed algorithm provides significantly better compression performance than the static mesh coder, which encodes each frame independently.