1,344,198 research outputs found

    Andreev reflection between a normal metal and the FFLO superconductor

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    We consider a process of the Andreev reflection between a normal metal and the s-wave superconductor in the FFLO state. It is shown that the process takes place if the energy of the incoming electron is bound within the finite interval called the Andreev window. The position of the window determines the value of the non-zero total momentum of Cooper pairs and the value of the gap

    Asymptotic Approximations for TCP Compound

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    In this paper, we derive an approximation for throughput of TCP Compound connections under random losses. Throughput expressions for TCP Compound under a deterministic loss model exist in the literature. These are obtained assuming the window sizes are continuous, i.e., a fluid behaviour is assumed. We validate this model theoretically. We show that under the deterministic loss model, the TCP window evolution for TCP Compound is periodic and is independent of the initial window size. We then consider the case when packets are lost randomly and independently of each other. We discuss Markov chain models to analyze performance of TCP in this scenario. We use insights from the deterministic loss model to get an appropriate scaling for the window size process and show that these scaled processes, indexed by p, the packet error rate, converge to a limit Markov chain process as p goes to 0. We show the existence and uniqueness of the stationary distribution for this limit process. Using the stationary distribution for the limit process, we obtain approximations for throughput, under random losses, for TCP Compound when packet error rates are small. We compare our results with ns2 simulations which show a good match.Comment: Longer version for NCC 201

    Daylight in window design

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    This paper expands on a case study of a Ralph Erskine University building located in Cambridge, UK. It explores the relationship between daylight, visual perception and window design. The scope of this paper is to serve as a reminder that window design has an important influence in the quality and use of architectural space. The paper suggests that through an articulated use of window types the designer has the opportunity to extend the control on the function and perception of a space. The conclusion shows examples of this articulation and proposes an integration of the effects of window design at the onset of the design process

    On the long time behavior of the TCP window size process

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    The TCP window size process appears in the modeling of the famous Transmission Control Protocol used for data transmission over the Internet. This continuous time Markov process takes its values in [0,)[0,\infty), is ergodic and irreversible. It belongs to the Additive Increase Multiplicative Decrease class of processes. The sample paths are piecewise linear deterministic and the whole randomness of the dynamics comes from the jump mechanism. Several aspects of this process have already been investigated in the literature. In the present paper, we mainly get quantitative estimates for the convergence to equilibrium, in terms of the W1W_1 Wasserstein coupling distance, for the process and also for its embedded chain.Comment: Correction

    The Simple Exclusion Process on the Circle has a diffusive Cutoff Window

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    In this paper, we investigate the mixing time of the simple exclusion process on the circle with NN sites, with a number of particle k(N)k(N) tending to infinity, both from the worst initial condition and from a typical initial condition. We show that the worst-case mixing time is asymptotically equivalent to (8π2)1N2logk(8\pi^2)^{-1}N^2\log k, while the cutoff window, is identified to be N2N^2. Starting from a typical condition, we show that there is no cutoff and that the mixing time is of order N2N^2.Comment: 37 pages, 3 Figure

    Reserve requirements and the discount window in recent decades

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    Reserve requirements and the discount window have long supported open market operations in the monetary policy process. Focusing on the last four decades, the author first examines the effects of required reserves on policy implementation, bank behavior, and government revenues, giving special attention to the recent cuts in requirements. She then considers the rules governing access to the discount window and the factors influencing banks' use of the window.Bank reserves ; Discount window
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