This paper addresses the problem of critical point calculations for pairwise comparisons of three normal means. One-sided and two-sided pairwise comparisons are standard multiple comparisons procedures, and while tabl...
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This paper addresses the problem of critical point calculations for pairwise comparisons of three normal means. One-sided and two-sided pairwise comparisons are standard multiple comparisons procedures, and while tables of critical points exist for balanced situations with equal sample sizes, only limited tables of critical points exist for unbalanced cases. A new algorithm is developed in this paper using elementary methods which allows the critical points to be found in all situations using only a one-dimensional numerical integration. Programs have been developed to implement the algorithm which will allow experimenters to easily find the required critical points and p-values. (C) 2008 Elsevier B.V. All rights reserved.
With the growing popularity of the MPEG-1 Audio Layer 3 (MP3) format, handheld devices such as personal digital assistants (PDAs) and mobile phones have become important entertainment platforms. Unlike conventional au...
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With the growing popularity of the MPEG-1 Audio Layer 3 (MP3) format, handheld devices such as personal digital assistants (PDAs) and mobile phones have become important entertainment platforms. Unlike conventional audio equipment, mobile devices are characterized by limited processing power, battery life, and memory, as well as other constraints. Therefore, music-processing tasks like beat detection must be implemented using low-complexity algorithms to cope with the constraints of these mobile devices.
We present a system for streaming live entertainment content over the Internet originating from a single source to a scalable number of consumers without resorting to centralized or provider-provisioned resources. The...
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We present a system for streaming live entertainment content over the Internet originating from a single source to a scalable number of consumers without resorting to centralized or provider-provisioned resources. The system creates a peer-to-peer overlay network, which attempts to optimize use of existing capacity to ensure quality of service, delivering low startup delay and lag in playout of the live content. There are three main aspects of our solution: first, a swarming mechanism that constructs an overlay topology for minimizing propagation delays from the source to end consumers;second, a distributed overlay anycast system that uses a location-based search algorithm for peers to quickly find the closest peers in a given stream;and finally, a novel incentive mechanism that encourages peers to donate capacity even when the user is not actively consuming content.
In this paper we review some theoretical aspects of the dynamics of the mesoscale filaments extending along the magnetic field lines in the edge plasma, which are often called 'blobs'. We start with a brief hi...
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In this paper we review some theoretical aspects of the dynamics of the mesoscale filaments extending along the magnetic field lines in the edge plasma, which are often called 'blobs'. We start with a brief historical survey of experimental data and the main ideas on edge and SOL plasma transport, which finally evolved into the modern paradigm of convective very-intermittent cross-field edge plasma transport. We show that both extensive analytic treatments and numerical simulations demonstrate that plasma blobs with enhanced pressure can be convected coherently towards the wall. The mechanism of convection is related to an effective gravity force (e.g. owing to magnetic curvature effects), which causes plasma polarization and a corresponding E x B convection. The impacts of different effects (e.g. X-point magnetic geometry, plasma collisionality, plasma beta, etc.) on blob dynamics are considered. Theory and simulation predict, both for current tokamaks and for ITER, blob propagation speeds and cross-field sizes to be of the order of a few hundred meters per second and a centimeter, respectively, which are in reasonable agreement with available experimental data. Moreover, the concept of blobs as a fundamental entity of convective transport in the scrape-off layer provides explanations for observed outwards convective transport, intermittency and non-Gaussian statistics in edge plasmas, and enhanced wall recycling in both toroidal and linear machines.
This paper gives algorithms for determining real-valued univariate unimodal regressions, that is, for determining the optimal regression which is increasing and then decreasing. Such regressions arise in a wide variet...
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This paper gives algorithms for determining real-valued univariate unimodal regressions, that is, for determining the optimal regression which is increasing and then decreasing. Such regressions arise in a wide variety of applications. They are shape-constrained nonparametric regressions, closely related to isotonic regression. For unimodal regression on n weighted points our algorithm for the L-2 metric requires only Theta(n) time, while for the L-1 metric it requires Theta(n log n) time. For unweighted points our algorithm for the L. metric requires only Theta(n) time. All of these times are optimal. Previous algorithms were for the L-2 metric and required Omega(n(2)) time. All previous algorithms used multiple calls to isotonic regression, and our major contribution is to organize these into a prefix isotonic regression, determining the regression on all initial segments. The prefix approach reduces the total time required by utilizing the solution for one initial segment to solve the next. (C) 2008 Elsevier B.V. All rights reserved.
The random displacement of magnetic field lines in the presence of magnetic turbulence in plasmas is investigated from first principles. A two-component (slab/two-dimensional composite) model for the turbulence spectr...
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The random displacement of magnetic field lines in the presence of magnetic turbulence in plasmas is investigated from first principles. A two-component (slab/two-dimensional composite) model for the turbulence spectrum is employes. An analytical investigation of the asymptotic behavior of the field-line mean square displacement (FL-MSD) is carried out. It is shown that the magnetic field lines behave superdifusively for every large values of the position variable z, since the FL-MSD sigma varies as sigma similar to z(4/3). An intermediate diffusive regime may also possible exist for finite values of z under conditions which are explicitly determined in terms of the intrinsic turbulent plasma parameters. The superdiffusie asymptotic result is confirmed numerically via an iterative algorithm. The relevance to previous resuslts is discussed.
This paper investigates the satisfiability of Propositional Projection Temporal Logic (PPTL) with infinite models. A decision procedure for PPTL formulas is given. To this end, Normal Form (NF) and Labeled Normal Form...
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This paper investigates the satisfiability of Propositional Projection Temporal Logic (PPTL) with infinite models. A decision procedure for PPTL formulas is given. To this end, Normal Form (NF) and Labeled Normal Form Graph (LNFG) for PPTL formulas are defined, and algorithms for transforming a formula to its normal form and constructing the LNFG for the given formula are presented. Further, the finiteness of LNFGs is proved in details. Moreover, the decision procedure is extended to check the satisfiability of the formulas of Propositional Interval Temporal Logic. In addition, examples are also given to illustrate how the decision procedure works.
Recently, a variable step-size affine projection (VSS-AP) algorithm has been introduced. The algorithm provides faster convergence rate and lower misadjustment but has heavy computational complexity. Proposed is a new...
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Recently, a variable step-size affine projection (VSS-AP) algorithm has been introduced. The algorithm provides faster convergence rate and lower misadjustment but has heavy computational complexity. Proposed is a new variable step-size pseudo affine projection (VSS-PAP) algorithm, which not only has a much lower complexity than the VSS-AP algorithm but also provides performance comparable with the conventional algorithm. Simulation results confirm fast convergence rate and small misalignment of the proposed algorithm with less computational complexity.
Wireless mesh networking is an emerging technology for future broadband wireless access. Future wireless networking can benefit from a robust and reliable wire-less can less mesh backbone rendered by me routers, provi...
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Wireless mesh networking is an emerging technology for future broadband wireless access. Future wireless networking can benefit from a robust and reliable wire-less can less mesh backbone rendered by me routers, providing an all-wireless ambience. Due to the requisite multichannel communications for high-speed data transmissions, power allocation for opportunistically exploiting fading wireless channels, and packet scheduling for QoS provisioning, joint power-frequency-time resource allocation is indispensable. In this article we propose a low-complexity intracluster resource allocation algorithm, taking power allocation, subcarrier allocation, and packet scheduling into consideration. Numerical results demonstrate that our scheme is near optimal, and that our optimality-driven resource allocation approach outperforms a greedy algorithm, working out a better performance compromise among throughput, packet dropping rate, and packet delay.
Conventional messaging technologies have been designed for large transactional systems, making the prediction and calibration of their delay impractical. In this paper, we present a minimal messaging system, implement...
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Conventional messaging technologies have been designed for large transactional systems, making the prediction and calibration of their delay impractical. In this paper, we present a minimal messaging system, implemented in Java (TM), that is designed to enable the analysis, modeling, and calibration of the expected performance of these technologies. We describe the algorithms and protocols that underlie this messaging system, show how an analysis can be performed, and give the actual measured performance figures. We show that the system achieves a throughput of more than 100,000 messages per second with less than 120-millisecond maximum latency, in the test environment. At 10,000 messages per second, a maximum latency of 5 milliseconds is measured. The algorithms make use of lock-free data structures, which allow the throughput to scale on multi-core systems.
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