We report the DC electrical transport properties in the conducting Langmuir-Blodgett (LB) films formed by a molecular association of the electroactive donor molecule bis(ethylenedioxy)tetrathiafulvalene (BEDO-TTF) and...
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We report the DC electrical transport properties in the conducting Langmuir-Blodgett (LB) films formed by a molecular association of the electroactive donor molecule bis(ethylenedioxy)tetrathiafulvalene (BEDO-TTF) and stearic acid CH3(CH2)(16)COOH. The DC resistivity is 1.25 x 10(-2) Omegacm at 300 K and the temperature variation is metallic. A logarithmic increase of the DC resistivity and the negative magnetoresistance are observed below 120 K. They are interpreted by the weak localization (WL) of a two-dimensional (2D) electronic system confined within the homogeneous conducting layer with molecular size thickness of BEDO-TTF. The existence of the WL indicates that the system is essentially in the coherent regime. A mesoscopic scale of the electronic length with phase memory provides evidence of the 2D coherent charge transport in the conducting LB films. (C) 2002 Elsevier Science B.V. All rights reserved.
The design and implementation of a fuzzy logic controller on a computer disk drive track-following servo system with the Texas Instruments TMS320C30 digital signal processor board is presented in this paper. The resea...
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The design and implementation of a fuzzy logic controller on a computer disk drive track-following servo system with the Texas Instruments TMS320C30 digital signal processor board is presented in this paper. The research is part of the ongoing effort to design a single fuzzy logic controller which will handle both the track following and seeking motions of the disk head servo mechanism. The integrated fuzzy logic controller is expected to reduce the switching transients between the following and the seeking motions, which is the bottleneck for current disk head servo controller design. A Zentek 3100 disk drive is modified to accommodate the fuzzy logic control loop. The control rules are constructed by considering the track error and the track-crossing error. The experimental results are presented, which show that the proposed fuzzy logic controller can achieve satisfactory performance.
Content-centric networking (CCN) advocates a new transport model tailored to named-data communication. Three features distinguish CCN transport from the TCP/IP model: unique endpoint at the receiver, pull-based data r...
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ISBN:
(纸本)9781450314190
Content-centric networking (CCN) advocates a new transport model tailored to named-data communication. Three features distinguish CCN transport from the TCP/IP model: unique endpoint at the receiver, pull-based data retrieval in a point to multi-point fashion and in-path caching. The definition of transport control mechanisms is of fundamental importance within the CCN architectural design and beyond, in the broader scope of information-centric networks. In this work, we propose a joint Hop-by-hop and Receiver-driven Interest Control Protocol (HR-ICP) to regulate user requests (Interests) either at the receiver and at intermediate nodes via Interest shaping. We prove that HR- ICP is stable and converges to an efficient and max-min fair equilibrium. Compared to controlling traffic only at the receiver, HR-ICP accelerates congestion reaction and reduces the loss rate, as we show by means of CCN packet-level simulations. In different network scenarios, we highlight the advantages of our solution in terms of faster convergence to the optimal throughput, robustness against misbehaving receivers and flow protection of delay-sensitive applications. Copyright 2012 ACM.
In the functional programming literature, compiling is often expressed as a translation between source and target program calculi. In recent work, Sabry and Wadler proposed the notion of a reflection as a basis for re...
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ISBN:
(纸本)9783540633983
In the functional programming literature, compiling is often expressed as a translation between source and target program calculi. In recent work, Sabry and Wadler proposed the notion of a reflection as a basis for relating the source and target calculi. A reflection elegantly describes the situation where there is a kernel of the source language that is isomorphic to the target language. However, we believe that the reflection criteria is so strong that it often excludes the usual situation in compiling where one is compiling from a higher-level to a lower-level language. We give a detailed analysis of several translations commonly used in compiling that fail to be reflections. We conclude that, in addition to the notion of reflection, there are several relations weaker a reflection that are useful for characterizing translations. We show that several familiar translations (that are not naturally reflections) form what we call a reduction correspondence. We introduce the more general notion of a (R1, R2, R3, R4 correspondence as a framework for describing relations between source and target calculi.
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