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IEEE International Conference on Cluster Computing

作者： A. Wagner Hyun-Wook Jin D.K. Panda R. Riesen Network-Based Computing Laboratory Department of Computer Science and Engineering Ohio State Uinversity USA Scalable Computing Systems Dept Sandia National Laboratories USA

Many of the modern networks used to interconnect nodes in cluster-based computing systems provide network-interface cards (NICs) that offer programmable processors. Substantial research has been done with the focus of offloading processing from the host to the NIC processor. However, the research has primarily focused on the static offload of specific features to the NIC, mainly to support the optimization of common collective and synchronization-based communications. We describe the design and implementation of a framework based on MP1CH-GM to support the dynamic NIC-based offload of user-defined modules for Myrinet clusters. We evaluate our implementation on a 16-node cluster using a NIC-based version of the common broadcast operation and we find a maximum factor of improvement of 1.2 with respect to total latency as well as a maximum factor of improvement of 2.2 with respect to average CPU utilization under conditions of process skew. In addition, we see that these improvements increase with system size, indicating that our NIC-based framework offers enhanced scalability when compared to a purely host-based approach.

关键词： computer networks Microprogramming Laboratories Delay computer science Broadcasting Multiprocessor interconnection networks Contracts Debugging Production systems

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Contributions to model characterization of geophone sensor

Contributions to model characterization of geophone sensor

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IEEE Instrumentation and Measurement Technology Conference

作者： X. Roset J. del Rio A. Manuel R. Palomera-Garcia SARTI Remote Acquisition Systems and Inlbrmation Processing ( IT Network ) University of Catalonia Vilanova i la GeltrU Spain Department of Electrical and Computer Engineering University of Puerto Rico Mayaguez Puerto Rico

In an oceanographic campaign of seismic prospecting it is often needed equipments with geophones to measure the motion of the sea bed. Normally, the signal is weak compared to the noise because the source is a few kilometres away from the sensor. The noise is due to the ambient in the ocean (seismic activity, currents, etc) and the electronic noise in the equipment (sensor, amplifier stage, A/D converter, hard disc and connexions). In order to characterize the electromagnetic geophone sensor and the performance with amplifier stage we have found models of a geophone sensor and we have simulated them with different amplifiers to improve the ratio S/N.

关键词： Sensor phenomena and characterization Geologic measurements Sea measurements Vibration measurement Oceans Frequency measurement Seismic measurements Circuit simulation Electromagnetic measurements Transfer functions

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Impact analysis of faults and attacks in large-scale networks

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IEEE Security and Privacy 2003年第5期1卷 49-54页

作者： Hariri, Salim Guangzhi, Q.U. Dharmagadda, Tushneem Ramkishore, Modukuri Raghavendra, Cauligi S. University of Arizona Tucson University of Southern California Department of Electrical and Computer Engineering University of Arizona Next Generation Network Centric Systems ITL Lab. University of Arizona Tucson AZ 85719 Analog Devices Company Wilmington MA Department of Electrical Engineering-Systems USC

An agent-based framework for the impact analysis of faults and attacks in large-scale networks is discussed. The framework is used to discover attack points and to examine the behavior of critical network components during an attack or system fault. The two common types of attacks are server attacks such as TCP SYN, and ICMP flood, and routing attacks, such as distributed denial-of-service (DDoS) attacks. In network attacks, attackers overwhelm the target system with a continuous flood of traffic designed to consume all system resources. The framework analyze the impact of multiple failures on overall system behavior and identify critical resources and vulnerabilities.

关键词： Telecommunication networks

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On the cost-quality tradeoff in topology-aware overlay path probing 11

On the cost-quality tradeoff in topology-aware overlay path ...

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11th IEEE International Conference on network Protocols, ICNP 2003

作者： Tang, Chiping McKinley, P.K. Software Engineering and Network Systems Laboratory Department of Computer Science and Engineering Michigan State University East LansingMI48824 United States

ISBN: (纸本)0769520243

Path probing is essential to maintaining an efficient overlay network topology. However, the cost of a full-scale probing is as high as O(n2), which is prohibitive in large-scale overlay networks. Several methods have been proposed to reduce probing overhead, although at a cost in terms of probing completeness. In this paper, an orthogonal solution is proposed that trades probing overhead for estimation accuracy in sparse networks such as the Internet. The proposed solution uses network-level path composition information (for example, as provided by a topology server) to infer path quality without full-scale probing. The inference metrics include latency, loss rate and available bandwidth. This approach is used to design several probing algorithms, which are evaluated through analysis and simulation. The results show that the proposed method can significantly reduce probing overhead while providing hounded quality estimations for all n × (n - 1) overlay paths. The solution is well suited to medium-scale overlay networks in the Internet. In other environments, it can be combined with extant probing algorithms to further improve performance. © 2003 IEEE.

关键词： Bandwidth

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A computationally efficient and secure time scheme for wireless applications

A computationally efficient and secure time scheme for wirel...

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58th IEEE Vehicular Technology Conference, VTC 2003-Fall

作者： Barnett, C.A. Liu, K.J.R. Hughes Network Systems GermantownMD United States Electrical and Computer Engineering Department University of Maryland College ParkMD United States

ISBN: (纸本)0780379543

Wireless mobile computing devices are used extensively to access the Internet for critical applications and services, which must be secured by computationally efficient algorithms and schemes. Computationally efficient security schemes, however, require accurate time synchronization between client and application servers, which is very challenging due to its susceptibility to stochastic noise on the transmission path and to message delay attacks where an adversary can intentionally delay measurement messages in order to compromise the scheme. In statistically noisy networks, accurate time synchronization requires filtering of a large number of measurements to reduce stochastic noise. Each measurement must be secured and, therefore, computationally efficient schemes are required to facilitate mobile computing. Efficient security schemes are also required to detect message delay attacks and to authenticate synchronization message sources (e.g. multicast host server and clients). We propose a computationally efficient time synchronization scheme, which achieves accurate and reliable time clock-offset estimates from a single measurement. This approach is based on a per node quality of service scheme, which can be easily incorporated into existing and emerging quality of service scheduling disciplines. It is designed to reduce stochastic noise by providing per node delay guarantee for synchronization. We also propose an efficient and reliable scheme to detect message delay attack. The proposed scheme compares synchronization messages round trip delay with predefined thresholds to ensure that they fall within expected limits, otherwise they are discarded. © 2004 IEEE.

关键词： Quality of service

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A requirements patterns-driven approach to specify systems and check properties

Lecture Notes in Computer Science (including subseries Lectu...

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Lecture Notes in computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 2003年 2648卷 18-33页

作者： Konrad, Sascha Campbell, Laura A. Cheng, Betty H. C. Deng, Min Software Engineering and Network Systems Laboratory Department of Computer Science and Engineering Michigan State University East Lansing MI 48824 United States

We previously developed a framework, Hydra, for adding formal semantics to a collection of UML diagrams that enable the automated derivation of formal language specifications for those diagrams. Recently, we have also identified a number of requirements patterns for embedded systems that includes sample UML structural and behavioral diagrams for modeling requirements and high-level design for embedded systems. This paper describes a requirements patterns-driven approach for developing UML diagrams for embedded systems, where each pattern has a constraints section to specify safety and other invariant properties. We show how the diagrams for an industrial automotive system, via specifications generated from Hydra, can be automatically analyzed for adherence to these formally specified constraints using the SPIN model checker. We developed the MINERVA framework to support the graphical construction of UML diagrams and to visualize the results from the SPIN analysis in terms of the original UML diagrams. © Springer-Verlag Berlin Heidelberg 2003.

关键词： Embedded systems

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DEVISE: a methodology for building Web services based infrastructure for collaborative enterprises

DEVISE: a methodology for building Web services based infras...

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IEEE International Workshop on Enabling Technologies: Infrastructure for Collaborative Enterprises (WET ICE)

作者： N. Dhyanesh G.C. Vineel S.V. Raghavan Network Systems Laboratory Department of Computer Science and Engineering Indian Institute of Technology Madras Chennai India

Web services define a new paradigm in present-day collaborative application development in enterprises, and span systems, networks, and organizations. Emerging computing infrastructures provide direct support for Web services technologies. A characteristic feature of the current efforts in the direction of Web services is the inclination towards providing rich and sophisticated tools for leveraging Web services functionality. Though this aids one in collaborative application "development" using Web services, from the point of view of application "design", it leaves much to be desired, when one considers closing in of the legendary "semantic gap" between a collaborative enterprise application and the infrastructure support. In this paper, we propose DEVISE: a methodology for building Web services based infrastructure for collaborative enterprises, comprising applications designed as a collection of Web services and a computer human interface.

关键词： Web services Application software Buildings Collaborative work Software engineering computer architecture Distributed computing Design methodology International collaboration Process design

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On the cost-quality tradeoff in topology-aware overlay path probing

On the cost-quality tradeoff in topology-aware overlay path ...

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International Conference on network Protocols

作者： Chiping Tang P.K. McKinley Software Engineering and Network Systems Laboratory Department of Computer Science and Engineering Michigan State University East Lansing MI USA

Path probing is essential to maintaining an efficient overlay network topology. However, the cost of a full-scale probing is as high as O(n/sup 2/), which is prohibitive in large-scale overlay networks. Several methods have been proposed to reduce probing overhead, although at a cost in terms of probing completeness. In this paper, an orthogonal solution is proposed that trades probing overhead for estimation accuracy in sparse networks such as the Internet. The proposed solution uses network-level path composition information (for example, as provided by a topology server) to infer path quality without full-scale probing. The inference metrics include latency, loss rate and available bandwidth. This approach is used to design several probing algorithms, which are evaluated through analysis and simulation. The results show that the proposed method can significantly reduce probing overhead while providing hounded quality estimations for all n /spl times/ (n - 1) overlay paths. The solution is well suited to medium-scale overlay networks in the Internet. In other environments, it can be combined with extant probing algorithms to further improve performance.

关键词： network topology Costs IP networks Algorithm design and analysis Large-scale systems network servers Web server Delay Bandwidth Inference algorithms

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Enhancing the fault-tolerance of nonmasking programs

Enhancing the fault-tolerance of nonmasking programs

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International Conference on Distributed Computing systems

作者： S.S. Kulkarni A. Ebnenasir Department of Computer Science and Engineering Software Engineering and Network Systems Laboratory Michigan State University East Lansing MI USA

In this paper we focus on automated techniques to enhance the fault-tolerance of a nonmasking fault-tolerant program to masking. A masking program continually satisfies its specification even if faults occur. By contrast, a nonmasking program merely guarantees that after faults stop occurring, the program recovers to states from where it continually satisfies its specification. Until the recovery is complete, however a nonmasking program can violate its (safety) specification. Thus, the problem of enhancing fault-tolerance from nonmasking to masking requires that safety be added and recovery be preserved. We focus on this enhancement problem for high atomicity programs-where each process can read all variables-and for distributed programs-where restrictions are imposed on what processes can read and write. We present a sound and complete algorithm for high atomicity programs and a sound algorithm for distributed programs. We also argue that our algorithms are simpler than previous algorithms, where masking fault-tolerance is added to a fault-intolerant program. Hence, these algorithms can partially reap the benefits of automation when the cost of adding masking fault-tolerance to a fault-intolerant program is high. To illustrate these algorithms, we show how the masking fault-tolerant programs for triple modular redundancy and Byzantine agreement can be obtained by enhancing the fault-tolerance of the corresponding nonmasking versions. We also discuss how the derivation of these programs is simplified when we begin with a nonmasking fault-tolerant program.

关键词： Fault tolerance Safety Fault tolerant systems Software engineering Laboratories computer science Automation Costs Redundancy engineering profession

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Architecture and operation of an adaptable communication substrate

Architecture and operation of an adaptable communication sub...

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IEEE Workshop on Future Trends of Distributed Computing systems

作者： S.M. Sadjadi P.K. McKinley E.P. Kasten Software Engineering and Network Systems Laboratory Department of Computer Science and Engineering Michigan State University East Lansing MI USA

This paper describes the internal architecture and operation of an adaptable communication component called the MetaSocket. MetaSockets are created using Adaptive Java, a reflective extension to Java that enables a component's internal architecture and behavior to be adapted at run time in response to external stimuli. This paper describes how adaptive behavior is implemented in MetaSockets, as well as how MetaSockets interact with other adaptive components, such as decision makers and event mediators. Results of experiments on a mobile computing testbed demonstrate how MetaSockets respond to dynamic wireless channel conditions in order to improve the quality of interactive audio streams delivered to iPAQ handheld computers.

关键词： Java computer architecture Handheld computers Application software Military computing computer languages Middleware Sockets Time factors Streaming media

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