11,509 research outputs found

    The Buffered \pi-Calculus: A Model for Concurrent Languages

    Full text link
    Message-passing based concurrent languages are widely used in developing large distributed and coordination systems. This paper presents the buffered π\pi-calculus --- a variant of the π\pi-calculus where channel names are classified into buffered and unbuffered: communication along buffered channels is asynchronous, and remains synchronous along unbuffered channels. We show that the buffered π\pi-calculus can be fully simulated in the polyadic π\pi-calculus with respect to strong bisimulation. In contrast to the π\pi-calculus which is hard to use in practice, the new language enables easy and clear modeling of practical concurrent languages. We encode two real-world concurrent languages in the buffered π\pi-calculus: the (core) Go language and the (Core) Erlang. Both encodings are fully abstract with respect to weak bisimulations

    Intermediate-pressure phases of cerium studied by an LDA + Gutzwiller method

    Full text link
    The thermodynamic stable phase of cerium metal in the intermediate pressure regime (5.0--13.0 GPa) is studied in detail by the newly developed local-density approximation (LDA)+ Gutzwiller method, which can include the strong correlation effect among the 4\textit{f} electrons in cerium metal properly. Our numerical results show that the α"\alpha" phase, which has the distorted body-centered-tetragonal structure, is the thermodynamic stable phase in the intermediate pressure regime and all the other phases including the α′\alpha' phase (α\alpha-U structure), α\alpha phase (fcc structure), and bct phases are either metastable or unstable. Our results are quite consistent with the most recent experimental data.Comment: 17 pages, 7 figure

    On a one-dimensional optimization problem derived from the efficiency analysis of Newton-PCG-like algorithms

    Get PDF
    AbstractThe Newton-PCG (preconditioned conjugate gradient) like algorithms are usually very efficient. However, their efficiency is mainly supported by the numerical experiments. Recently, a new kind of Newton-PCG-like algorithms is derived in (J. Optim. Theory Appl. 105 (2000) 97; Superiority analysis on truncated Newton method with preconditioned conjugate gradient technique for optimization, in preparation) by the efficiency analysis. It is proved from the theoretical point of view that their efficiency is superior to that of Newton's method for the special cases where Newton's method converges with precise Q-order 2 and α(⩾2), respectively. In the process of extending such kind of algorithms to the more general case where Newton's method has no fixed convergence order, the first is to get the solutions to the one-dimensional optimization problems with many different parameter values of α. If these problems were solved by numerical method one by one, the computation cost would reduce the efficiency of the Newton-PCG algorithm, and therefore is unacceptable. In this paper, we overcome the difficulty by deriving an analytic expression of the solution to the one-dimensional optimization problem with respect to the parameter α

    The Accounting Methods of the Local Government Department Output by Factor Analysis

    Get PDF
    In this paper, using the 2011 national economic accounting data of the provinces, we evaluated the government department performance by factor analysis. And then calculated the local government department's total output taking advantage of the labor production efficiency. And the labor production efficiency of government department concludes the performance information. Which will improved the method of accounting government department's output by cost
    • …
    corecore