1644414
A 2-slot time-division multiplexing (TDM) interconnect network for gigascale integration (GSI)
In many wire-limited VLSI digital systems the time delay of the longest global interconnect can be a significant percentage of the clock period. However, because semi-global and global wires with shorter wire lengths can have a much smaller time delay, they can remain idle (i.e. not switching) for a significant portion of the clock period even after their data has been transmitted. To capitalize on this phenomenon, this paper proposes that a low-overhead 2-slot Time Division Multiplexing (TDM) network should be incorporated into the multilevel interconnect architectures of future GSI systems to help reduce the escalating manufacturing costs that are primarily due to the projected increase in the number of metal layers. Using system-level interconnect prediction (SLIP) techniques, it is shown that a 20% reduction in the number of metal levels could be achieved for a 100M transistor VLSI system with only a 5-10% increase in power dissipation.
6625273
Wave-pipelined 2-slot time division multiplexed (WP/2-TDM) routing
The ever-increasing number of transistors on a chip has resulted in very large scale integration (VLSI) systems whose performance and manufacturing costs are driven by on-chip wiring needs. This paper proposes a low overhead wave-pipelined two-slot time division multiplexed (WP/2-TDM) routing technique that harnesses the inherent intra-clock period wire idleness to implement wire sharing in combination with wave-pipelined circuit techniques. It is illustrated in this paper that WP/2-TDM routing can be readily incorporated into future gigascale integration (GSI) systems to reduce the number of interconnect routing channels in an attempt to contain escalating manufacturing costs. Two case studies, one at the circuit level and one at the system level, are presented to illustrate the advantages of WP/2-TDM routing. The circuit level implementation exhibits more than 40% reduction in wire area, a 30% reduction in silicon area with no increase in dynamic power and no loss of throughput performance.
11638124
Measuring benchmark similarity using inherent program characteristics
This paper proposes a methodology for measuring the similarity between programs based on their inherent microarchitecture-independent characteristics, and demonstrates two applications for it: 1) finding a representative subset of programs from benchmark suites and 2) studying the evolution of four generations of SPEC CPU benchmark suites. Using the proposed methodology, we find a representative subset of programs from three popular benchmark suites - SPEC CPU2000, MediaBench, and MiBench. We show that this subset of representative programs can be effectively used to estimate the average benchmark suite IPC, L1 data cache miss-rates, and speedup on 11 machines with different ISAs and microarchitectures - this enables one to save simulation time with little loss in accuracy. From our study of the similarity between the four generations of SPEC CPU benchmark suites, we find that, other than a dramatic increase in the dynamic instruction count and increasingly poor temporal data locality, the inherent program characteristics have more or less remained unchanged
5485929
ITTALKS: A Case Study in the Semantic Web and DAML
Effective use of the vast quantity of information now available on the web will require the use of "Semantic Web" markup languages such as the DARPA Agent Markup Language (DAML). Such languages will enable the automated gathering and processing of much information that is currently available but insufficiently utilized. Effectively, such languages will facilitate the integration of multi-agent systems with the existing information infrastructure. As part of our exploration of Semantic Web technology, and DAML in particular, we have constructed ITTALKS, a web-based system for automatic and intelligent notification of information technology talks. In this paper, we describe the ITTALKS system, and discuss the numerous ways in which the use of Semantic Web concepts and DAML extend its ability to provide an intelligent online service to both the human community and the agents assisting them.
3018861
Using peer-to-peer data routing for infrastructure-based wireless networks
A mobile ad-hoc network is an autonomous system of mobile routers that are self-organizing and completely decentralized with no requirements for dedicated infrastructure support. Wireless infrastructure in terms of base stations is often available in many popular areas offering highspeed data connectivity to a wired network. In this paper we describe an approach where infrastructure components utilize passing by mobile nodes to route data to other devices that are out of range. In our scheme, base stations track user mobility and determine data usage patterns of users as they pass by. Based on this, base stations predict the future data needs for a passing mobile device. These base stations then collaborate (over the wired network) to identify other mobile devices with spare capacity whose routes intersect that of a needy device and use these carriers to transport the needed data. When such a carrier meets a needy device, they form ad hoc peer-to-peer communities to transfer this data. In this paper, we describe the motivation behind our approach and the different component interactions. We present the results of simulation work that we have done to validate the viability of our approach. We also describe, Numi, our framework for supporting collaborative infrastructure and ad hoc computing along with a sample application built on top of this highlighting the benefits of our proposed approach.
1552091
Phrase Structure Trees Bear More Fruit than You Would Have Thought
In this paper we will present several results concerning phrase structure trees. These results show that phrase structure trees, when viewed in certain ways, have much more descriptive power than one would have thought. We have given a brief account of local constraints on structural descriptions and an intuitive proof of a theorem about local constraints. We have compared the local constraints approach to some aspects of Gazdar's framework and that of Peters and Ritchie and of Karttunen. We have also presented some results on skeletons (phrase structure trees without labels) which show that phrase structure trees, even when deprived of the labels, retain in a certain sense all the structural information. This result has implications for grammatical inference procedures.
6301369
Secure Routing and Intrusion Detection in Ad Hoc Networks
Numerous schemes have been proposed for secure routing and intrusion detection for ad hoc networks. Yet, little work exists in actually implementing such schemes on small handheld devices. In this paper, we present a proof-of-concept implementation of a secure routing protocol based on AODV over IPv6, further reinforced by a routing protocol independent intrusion detection system (IDS) for ad hoc networks. Security features in the routing protocol include mechanisms for nonrepudiation and authentication, without relying on the availability of a certificate authority (CA) or a key distribution center (KDC). We present the design and implementation details of our system, the practical considerations involved, and how these mechanisms can be used to detect and thwart malicious attacks. We discuss several scenarios where the secure routing and intrusion detection mechanisms isolate and deny network resources to nodes deemed malicious. We also discuss shortcomings in our approach, and conclude with lessons learned and ideas for future work