A key emerging and popular communication paradigm, primarily employed for information dissemination, is peer-to-peer (P2P) networking. In this paper, we model the spread of malware in decentralized, Gnutella type of p...
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Given the high computation demand for cryptography and hashing algorithms there is a need to develop flexible and high performance architectures. This paper proposes a methodology to derive processing elements as a st...
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ISBN:
(纸本)9781424416936
Given the high computation demand for cryptography and hashing algorithms there is a need to develop flexible and high performance architectures. This paper proposes a methodology to derive processing elements as a starting point for the state-of-the-art reconfigurable computing and presents a case-study to show that application-specific reconfigurable computing has performance benefits close to fully-custom designs in addition to the intended reconfigurablity. We use hashing algorithms as a case study to propose a novel application-specific reconfigurable architecture based on a balanced mixture of coarse and fine grained processing elements with a tuned interconnect structure. For that purpose we introduce a methodology to derive hybrid grained processing elements and expose both fine and coarse grain parallelism based on a new common and recurring computation pattern extraction tool. After extracting the recurring patterns between SHA-1 and MD5 algorithms, we derive the unified interconnect architecture tailored to the control data dependencies of both the algorithms. That way the amount of reconfiguration on the proposed architecture when switching between the two algorithms is minimized. The proposed reconfigurable architecture is synthesized using the Synopsys design compiler targeted at TSMC 250 nm libraries. We compare its performance with ASIC technology on SHA-1 and MD5 algorithms. Results show that the proposed architecture which is reconfigurable between the two hashing algorithms has frequency of operation close to ASIC implementation of the individual algorithms for iterative and pipelined versions and results with 35% savings in area.
parallel invocation of edge servers within a Web infrastructure has been shown to provide benefits, in terms of system responsiveness, for both content delivery applications and non-transactional Web services. This is...
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ISBN:
(纸本)0769525083
parallel invocation of edge servers within a Web infrastructure has been shown to provide benefits, in terms of system responsiveness, for both content delivery applications and non-transactional Web services. This is achieved thanks to the exploitation of path-diversity proper of multi-hop networks over the Internet, which typically reduces the likelihood of client perceived link congestion. In this work we address parallel invocation of geographically spread edge servers in the context of transactional Web-based applications. Actually, parallel invocation protocols are not trivial for this type of applications, since we need to deal with a set of issues not present in classical content delivery, applications, such as (i) non-idempotent business logic and (ii) increase of the workload on the data centers. In this paper we propose a simple and lightweight parallel invocation protocol for distributed transactions over the Web, which addresses all those issues in a scalable manner by requiring no form of coordination among (geographically spread) edge servers. The results of a simulation study are also reported to show the advantages from our protocol in terms of user-perceived system responsiveness.
Graphics processing units provide a large computational power at a very low price which position them as an ubiquitous accelerator. General purpose programming on the graphics processing units (GPGPU) is best suited f...
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This paper presents a distributed file-system for the present day medium-sized network. Existing servers and workstations pool their unused storage resources to form a communal share. Erasure codes provide fault toler...
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In a grid computing environment, resources are autonomous, wide-area distributed, and what's more, they are usually not free. These unique characteristics make scheduling in a self-sustainable and market-like grid...
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ISBN:
(纸本)0769523129
In a grid computing environment, resources are autonomous, wide-area distributed, and what's more, they are usually not free. These unique characteristics make scheduling in a self-sustainable and market-like grid highly challenging. The goal of our work is to build such a global computational grid that every participant has enough incentive to stay and play in it. There are two parties in the grid: resource consumers and resource providers. Thus the performance objective of scheduling is two-fold: for consumers, high successful execution rate of jobs, and for providers, fair allocation of benefits. We propose an incentive-based grid scheduling, GridIS, which is composed of a P2P decentralized scheduling framework and incentive-based scheduling algorithms. Simulation results show that GridIS guarantees the incentive of every participant to a satisfying extent.
More and more pieces of hardware are being connected to the Internet every day. Technologies such as Bluetooth or Wi-Fi make this evolution even faster. To make these equipments cooperate and communicate with each oth...
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ISBN:
(纸本)0769523129
More and more pieces of hardware are being connected to the Internet every day. Technologies such as Bluetooth or Wi-Fi make this evolution even faster. To make these equipments cooperate and communicate with each other several paradigms such as mobile codes, mobile agents and remote procedure calls are particularly well adapted. These paradigms enable to execute a code that is either coming from somewhere over the network, or that is local but managed remotely. Security is then one of the main concerns that has to be dealt with. We believe that smart cards, and more precisely Java Cards can help to cope with this challenge. This is a position paper where we present the first results obtained on a Java Card based platform that we have set up for experimentation purpose. These experiments raise many questions we are currently working on.
The Simultaneous Optical Multiprocessor Exchange Bus (SOME-Bus) is a low-latency, high-bandwidth interconnection network that directly links arbitrary pairs of processor nodes without contention, and can efficiently i...
Data-driven computing and using data for strategic advantages are exemplified by communication systems, and the speech intelligibility in communication systems is generally interrupted by interfering noise. This inter...
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ISBN:
(纸本)9781479941162
Data-driven computing and using data for strategic advantages are exemplified by communication systems, and the speech intelligibility in communication systems is generally interrupted by interfering noise. This interference comes from the environmental noise, so we can reduce them intelligibility by masking the interested signal [1, 2]. An important work in communication systems is to extract speech from noisy speech and inhibiting background noise. In this paper, the subspace algorithm theory is introduced into a speech noise reduction system. We first analyze the principle of LMS adaptive speech noise reduction algorithm with the subspace algorithm, and then, we merge the subspace algorithm into the VS-LMS algorithm and propose a combined algorithm for an adaptive speech noise reduction system. Furthermore, we analyze the combined algorithm, which can decrease musical noise, as well as generate a suitable step-size factor to resolve the contradiction. This issue cannot be resolved by the current LMS algorithm [31], which has less convergence speed and larger residual noise than our system. Our simulation results demonstrate that our algorithm can get 3 to 10 times better than original algorithm in low SNR (-5 similar to 0db) and high SNR (0 similar to + 5db).
Due to the increasing complexity, the behavior of large-scale distributed systems becomes difficult to predict. The ability of on-line identification and autotuning of adaptive control systems has made the adaptive co...
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ISBN:
(纸本)0769523129
Due to the increasing complexity, the behavior of large-scale distributed systems becomes difficult to predict. The ability of on-line identification and autotuning of adaptive control systems has made the adaptive control theoretical design an attractive approach for quality of service (QoS) guarantee. However, there is an inherent constraint in adaptive control systems, i.e. a conflict between asymptotically good control and asymptotically good parameter estimates. This paper addresses these limitations via sensitivity analysis. The simulation study demonstrates that the adaptive control theoretical design depends on the excitation signal, environment uncertainty, and a priori knowledge on the system. In addition, this paper proposes an adaptive dual control framework for mitigating these constraints in QoS design. By incorporating the existing uncertainty of the on-line prediction into the control strategy, the dual adaptive control framework optimizes the tradeoff between the control goal and the uncertainty.
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