路由芯片中的微流水设计

微流水技术是异步电路中实现流水线设计的有效方法,而路由芯片是高速通信网络中的重要硬件部件。文中首先介绍了微流水设计的基本结构和控制,然后介绍了采用 洞机制的路由芯片的工作机理,并给出了利用微流水实现ＡＳＩＣ路由芯片的具体应用,该芯片达到了简单、高效、可靠的设计目标,文中的最后还给出了在线较复杂的电路系统中实现微流水所需要进一步研究的问题。     

移动Ad Hoc网络安全按需路由协议

Ad Hoc网络的安全性问题越来越引起人们的关注,如何确保Ad Hoc网络路由协议的安全成为Ad Hoc研究的一项关键技术。提出一种适用于移动Ad Hoc网络的安全按需源路由协议,利用移动节点之间的会话密钥和基于散列函数的消息鉴别码HMAC一起来验证路由发现和路由应答的有效性。提出的邻居节点维护机制通过把MAC地址和每个节点的ID绑定来防御各种复杂的攻击如虫洞攻击。NS-2仿真表明该协议能有效地探测和阻止针对Ad Hoc网络的大部分攻击。     

致密碳酸盐岩酸蚀蚓孔研究

基质酸化是碳酸盐岩储层最早使用的解除储层污染的增产技术之一。但现场实践表明,对于微裂缝不发育的致密碳酸盐岩储层,基质酸化效果往往不佳。该文利用压裂酸化工作液动态滤失实验系统,进行了系统的岩心驱替实验。通过改变酸液注入速率、实验温度及使用不同酸液体系等方法,对致密碳酸盐岩储层孔隙基质在酸化过程中蚓孔产生的可能性进行了实验研究。研究表明：对于致密碳酸盐岩,由于基质渗透率非常低,在10MPa的驱替压差下．酸液仍然很难进入岩心基质,所以酸岩反应仅能在岩石表面进行,即使部分酸液进入基质孔隙内,由于残酸难以快速滤失,所以鲜酸难以迅速补充,使得酸岩反应的类型仅能停留在密集型溶蚀阶段,难以形成深穿透的酸蚀蚓孔。此外,通过岩心流动实验对比,分析了高渗露头及致密岩心的流动反应特点,证实酸液在高渗透岩心表面及天然裂缝发育处能形成酸蚀蚓孔。最后,通过理论分析认为．对于致密碳酸盐岩储层基质酸化很难形成深穿透的酸蚀蚓孔。     

大规模并行处理系统互连通信的新技术研究

本文综述了大规模并行处理系统研究了工作的概况，指出其研究热点和关键技术是实现高效的互连通信。文中重点介绍了该领域的研究内容：结点结构、网络接口、切换技术，拓扑结构，路由算法，通信机制，通信协议，计算模型等。     

Multipath-Based Multicasting Strategies for Wormhole-Routed Star Graph Interconnection Networks

The star graph interconnection network has been recognized as an attractive alternative to the popular hypercube network. In this paper, we present a multipath-based multicast routing model for wormholerouted star graph networks, propose two efficient multipath routing schemes, and contrast the performance of the proposed schemes with the performance of the scheme presented in our previous work. Both of the two proposed schemes have been proven to be deadlock-free. The first scheme, simple multipath routing, uses multiple independent paths for concurrent multicasting. The second scheme, two-phase multipath routing, includes two phases: source-to-relay and relay-to-destination. For each phase, multicasting is carried out using simple multipath routing. Experimental results show that, for short and medium messages with small message startup latencies, the proposed schemes reduce multicast latency more efficiently than other schemes.     

All-To-All Personalized Communication in Wormhole-Routed 2D/3D Meshes and Multidimensional Interconnection Networks

2004.29计算机工程与应用1INTRODUCTIONInamessage-passingmulti-computernetwork,processorsoftenneedtocommunicatewitheachotherforvariousrea-sons,suchasloadbalancing,eventsynchronization,anddataexchange.Basedonthenumberofsendingandreceivingpro-cessors,thesecommunicationscanbeclassifiedintocommuni-cationpatternssuchasone-to-one(unicast),one-to-many(multicast),one-to-all(broadcast),andall-to-all.Thenatureofthemessagetobesentcanbeclassifiedaspersonalizedornon-personalized.Theall-to-allpersonalized…     

Adaptive Multimodule Routers for Multiprocessor Architectures

Recent multiprocessors such as Cray T3D support interprocessor communication using partitioned dimension-order routers (PDRs). In a PDR implementation, the routing logic and switching hardware is partitioned into multiple modules, with each module suitable for implementation as a chip. This paper proposes a method to incorporate adaptivity into such routers with simple changes to the router structure and logic. We show that with as few as two virtual channels per physical channel, adaptivity can be provided to handle nonuniform traffic in multidimensional meshes.     

A Performance Model of Adaptive Wormhole Routing in k-Ary n-Cubes in the Presence of Digit-Reversal Traffic

Several analytical models of fully adaptive routing in wormhole-routed k-ary n-cubes under the uniform traffic pattern have recently been proposed in the literature. Although the uniform reference model has been widely used by researchers, it is not always true in practice as there are many applications that exhibit traffic nonuniformity. There has hardly been any study that describes an analytical model of fully adaptive routing under nonuniform traffic conditions. This paper describes the first analytical model of fully adaptive routing in k-ary n-cubes in the presence of nonuniform traffic generated by the digit-reversal permutation, which is an important communication operation found in many matrix computation problems. Results obtained through simulation experiments confirm that the model predicts message latency with a good degree of accuracy under different working conditions.