Showing papers in "Performance Evaluation in 2011"

TL;DR: This work proposes a novel class of algorithms called Join-Idle-Queue (JIQ) for distributed load balancing in large systems, which effectively results in a reduced system load and produces 30-fold reduction in queueing overhead compared to Power-of-Two at medium to high load.

TL;DR: The Markov Reward Model Checker is a software tool for verifying properties over probabilistic models that supports PCTL and CSL model checking, and their reward extensions.

TL;DR: A model is proposed that can accurately capture the popularity dynamics of collections of recently-uploaded videos as they age, including key measures such as hot set churn statistics, and the evolution of the viewing rate and total views distributions over time.

TL;DR: NS2-CRAHN, an extension of the NS-2 simulator, is described, which is designed to support realistic simulation of CRAHNs and contains an accurate yet flexible modeling of the activities of PUs and of the cognitive cycle implemented by each CR user.

TL;DR: This paper studies the balking behavior of customers in the single-server queue with generally distributed service and vacation times and identifies equilibrium strategies and socially optimal strategies under two distinct information assumptions.

TL;DR: In this article, an energy aware routing protocol (EARP) is proposed to minimize a performance metric that combines the total consumed power in the network and the QoS that is specified for the flows.

TL;DR: An improved computation method of maximum likelihood estimation for phase-type (PH) distributions with a number of phases with a uniformization-based procedure for computing a convolution integral of the matrix exponential and an improvement of the forward–backward algorithm using time intervals is proposed.

TL;DR: The question of how to choose the number of reserves, and the up and down thresholds, is answered by analyzing a suitable queueing model and heuristics and numerical results are presented.

TL;DR: It is shown that when the perturbations are carefully chosen, PMW is able to achieve a utility that is within O(1/V) of the optimal value for any V>=1, while ensuring an average network backlog of O(V).

TL;DR: This work employs mean-field analysis techniques for the evaluation of gossip protocols, which approximates the behaviour of very large gossip networks, and can be evaluated using simple matrix-vector multiplications.

TL;DR: In this paper, the authors presented simple closed-form approximations for the mean waiting times in polling systems with renewal arrival processes, performing well for all workloads, using heavy traffic limits and newly developed light traffic limits, which may prove to be extremely useful for system design and optimisation in application areas as diverse as telecommunications, maintenance, manufacturing and transportation.

TL;DR: In this article, the authors focus on the feed-forward RNN model and its ability to solve classification problems and provide guidance to identify some gaps in the RNN's related literature and suggest directions for future research.

TL;DR: A new index rule for Markovian time-varying channels gives rise to a simple opportunistic scheduling rule for flow-level scheduling in wireless downlink systems, and suggests that information about the channels steady state is often enough to achieve near-optimality.

TL;DR: The initiative to collect and classify a bibliography on G-networks, which is the unified model for queueing networks and neural networks, is reported.

TL;DR: A comprehensive, longitudinal characterization study of the file hosting ecosystem using HTTP traces collected from a large campus network over a one-year period, which compares and contrast these services with each other as well as with peer-to-peer file sharing and other media sharing services.

TL;DR: Numerically, it is shown that for the exponentially distributed job sizes the myopic approach, ignoring the future arrivals, yields an efficient and robust policy when compared to other heuristics, however, in the case of highly asymmetric service rates, an FPI based policy outperforms it.

TL;DR: A fundamental formula is computed from which an entire gamut of known as well as new results regarding the buffer content of batch-service queues can be extracted and various quantities with regard to the customer delay are calculated.

TL;DR: The main theorem shows that, when the number of providers is small, oligopolistic equilibria can be extremely inefficient; however, as theNumber of providers N grows, the oligopolist equilibrian become increasingly efficient (at a rate of 1/N).

TL;DR: The proposed coupled thermal-performance model, which takes into account the complex relationship between the performance of servers, the allocation of workloads, the temperature of the air supplied by the conditioning unit and the heat distribution in the server room, is presented.

TL;DR: This paper has analyzed three non-intrusive models to measure and monitor voice quality using Random Neural Networks (RNN) and found that the simple feed-forward architecture has produced the most accurate results compared to the other two architectures.

TL;DR: This work characterize the growth rate of the mean response time under SRPT in the M/GI/1 system under general job size distributions and shows that the heavy traffic growth rate can be used to provide an accurate approximation formean response time outside of heavy traffic regime.

TL;DR: Two approaches to neighbor discovery are examined: direct discovery where each node explicitly discovers its neighbors, and gossip-based discovery where nodes exchange information about their already discovered neighbors via simulations.

TL;DR: This paper investigates packet scheduling in the context of Self-Optimizing Networks, and demonstrates how to improve coverage dynamically by adjusting the scheduling strategy, and proposes a coverage-capacity self-optimization algorithm based on @a-fair schedulers.

TL;DR: This work considers a saturated random-access network on a general conflict graph, and proves that for every feasible combination of throughputs, there exists a unique vector of back-off rates that achieves this throughput vector.

TL;DR: This work investigates the trade-off between performance and power consumption in servers hosting virtual machines running IT services through Generalized Processor Sharing queues enhanced with a green speed-scaling mechanism that controls the processing capacity to use depending on the number of active virtual machines.

TL;DR: The ''Price of Forgetting'' (PoF), the ratio between the minimum response times achieved by a probabilistic broker and a broker with memory, is shown to be unbounded or arbitrarily close to one depending on the coefficient of variation of the service time distributions.

TL;DR: Stability conditions for discrete-time queueing systems with preemptive server interruptions are investigated and sufficient conditions for the positive recurrence of the single-server and multiserver queueing processes are established for the preemptive repeat different and theemptive resume service disciplines.

TL;DR: A mathematical model is developed to quantitatively analyze a scalable region-based hierarchical group key management protocol integrated with intrusion detection to deal with both outsider and insider security attacks for group communication systems (GCSs) in mobile ad hoc networks (MANETs).

TL;DR: In this article, the fundamental capacity of a multiuser wireless downlink under two assumptions: (1) channels are not explicitly measured and thus instantaneous states are unknown; (2) Channels are modeled as ON/OFF Markov chains.