In this paper we develop distributed approaches for power allocation and scheduling in wireless access networks. We consider a model where users communicate over a set of parallel multi-access fading channels, as in a...
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ISBN:
(纸本)076952267X
In this paper we develop distributed approaches for power allocation and scheduling in wireless access networks. We consider a model where users communicate over a set of parallel multi-access fading channels, as in an OFDM or multi-carrier system. At each time, each user must decide which channels to transmit on and how to allocate its power over these channels. We give distributed power allocation and scheduling policies where each user's actions depend only on knowledge of their own channel gains. We characterize an optimal policy which maximizes the system throughput and also give a simpler sub-optimal policy which is shown to have the optimal scaling behavior in several asymptotic regimes.
Divisible load applications consist of a load, that is input data and associated computation, that can be divided arbitrarily into independent pieces. Such applications arise in many fields and are ideally suited to a...
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ISBN:
(纸本)0769523129
Divisible load applications consist of a load, that is input data and associated computation, that can be divided arbitrarily into independent pieces. Such applications arise in many fields and are ideally suited to a master-worker execution, but they pose several scheduling challenges. While the "Divisible Load Scheduling" (DLS) problem has been studied extensively from a theoretical standpoint, in this paper we focus on practical issues: we extend a production Grid application execution environment, APST, to support divisible load applications;we implement previously proposed DLS algorithms as part of APST;we evaluate and compare these algorithms on a real-world two-cluster platform;we show in a case study how a user can easily and effectively run a real-world divisible load application;and we uncover several issues that are critical for using DLS theory in practice. To the best of our knowledge the software resulting from this work, APST-DV, is the first usable and generic tool for deploying divisible load applications on distributed computing platforms.
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.
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.
One of the most serious security threats in the Internet are distributed Denial of Service (DDoS) attacks, due to the significant service disruption they can create and the difficulty to prevent them. In this paper, w...
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ISBN:
(纸本)0769523129
One of the most serious security threats in the Internet are distributed Denial of Service (DDoS) attacks, due to the significant service disruption they can create and the difficulty to prevent them. In this paper, we propose new deterministic packet marking models in order to characterize DDoS attack streams. Such common characterization can be used to make filtering near the victim more effective. In this direction we propose a rate control scheme that protects destination domains by limiting the amount of traffic during an attack, while leaving a large percentage of legitimate traffic unaffected. The above features enable providers to offer enhanced security protection against such attacks as a value-added service to their customers, hence offer positive incentives for them to deploy the proposed models. We evaluate the proposed marking models using a snapshot of the actual Internet topology, in terms of how well they differentiate attack traffic from legitimate traffic in cases of full and partial deployment.
We describe the design and implementation of MOCCA, a distributed CCA framework implemented using the H2O metacomputing system. Motivated by the quest for appropriate metasystem programming models for large scale scie...
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ISBN:
(纸本)0769523129
We describe the design and implementation of MOCCA, a distributed CCA framework implemented using the H2O metacomputing system. Motivated by the quest for appropriate metasystem programming models for large scale scientific applications, MOCCA combines the advantages of component orientation with the flexible and reconfigurable H2O middleware. By exploiting unique capabilities in H2O, including client-provider separation, security, and negotiable transport protocols, enhancements to both functionality and performance could be attained. The design and implementation of MOCCA highlights the natural match between CCA components and H2O pluglets, both in structure and invocation methodology. An outline of how native CCA modules can be supported in the MOCCA framework describes the potential for future deployment of legacy codes on metacomputing systems. We also report on preliminary experiences with test applications and sample performance measurements that favorably compare MOCCA to alternative component frameworks for tightly- and loosely-coupled metacomputing systems.
Fat-trees are a special case of multistage interconnection networks with quite good static fault tolerance capabilities. They are however straightforwardly unable to provide local dynamic fault tolerance. In this pape...
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ISBN:
(纸本)0769523129
Fat-trees are a special case of multistage interconnection networks with quite good static fault tolerance capabilities. They are however straightforwardly unable to provide local dynamic fault tolerance. In this paper we propose a network topology based on the fat-tree using two parallel networks with crossover links between them in an effort to enable dynamic fault tolerance. We evaluate and compare this topology with two other similar fat-tree topologies and show through simulations that the new topology is able to improve slightly upon the ability to tolerate faults statically. More importantly, we show that the new network topology is the only one of the evaluated topologies able to tolerate one fault dynamically, with a superior network performance in the face of dynamically handled faults.
Dynamic reconfigurable processor based on ALU array architecture for consumer appliances is described. To implement reconfigurable system on portable or mobile products, we have tried to develop smaller and powerful r...
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ISBN:
(纸本)0769523129
Dynamic reconfigurable processor based on ALU array architecture for consumer appliances is described. To implement reconfigurable system on portable or mobile products, we have tried to develop smaller and powerful reconfigurable processor. We have proposed the ALU array architecture with the limitation on the interconnection for area reduction. By the proposed architecture, we could reduce gate size by 63% on interconnections. Also, we have shown that the performance of proposed architecture is almost the same as one without limitations. The proposed processor is a parallelprocessing processor that consists of a sequencer and an ALU array, adopted multi threading technology. We have developed compilation tools from source codes written in C language for the proposed processor. We demonstrate the software model of the processor using MPEG-4 video decoding application.
A novel parallel optical proximity correction (OPC) technique is proposed for process distortion compensation of layout mask in design and fabrication of very large scale integration (VLSI) circuits. Based on a geneti...
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ISBN:
(纸本)0769523129
A novel parallel optical proximity correction (OPC) technique is proposed for process distortion compensation of layout mask in design and fabrication of very large scale integration (VLSI) circuits. Based on a genetic algorithm (GA), rule- and model-based correction methods, and domain decomposition algorithms, a parallel OPC system is successfully developed for the layout mask correction of VLSI circuits on a Linux-based PC cluster with the message passing interface (MPI) libraries. Tested on several layout patterns, the implemented pattern-based partition scheme shows good accuracy for the OPC-corrected layout mask of VLSI designs. Computational and parallel benchmarks, such as speedup and efficiency, are achieved and exhibit excellent performance of the developed system. Our approach provides an alternative in developing advanced computer aided design (CAD) tools and benefits design and fabrication of system-on-chip (SoC).
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