1,094 research outputs found

    Updated Methods for Traffic Impact Analysis, Including Evaluation of Innovative Intersection Designs: Volume II—Applicant’s Guide

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    The INDOT Applicant’s Guide to Traffic Impact Analysis (TIA) is a product of SPR-3605 Updated Methods for Traffic Impact Analysis . The purpose of this study was to review the Applicant’s and Reviewer’s Guides that were published in 1992 and make changes that would bring them in line with the methods and conditions that have emerged since then. This guide is intended to establish a standard framework for traffic impact analysis within Indiana, increasing consistency in study requests, preparation and review. A standardized procedure will enable the TIA study preparer to present the study findings and recommendations in a systematic manner consistent with the reviewer\u27s expectations. The guide is not intended to make things more complicated and time-consuming. On the contrary, with a standard framework, the time involved in the process will decrease for both parties. The Applicant\u27s Guide allows enough flexibility to the study preparer to use innovative methods based on sound engineering judgment and the conditions at a specific site. However, this should be done with the prior consent of the study reviewer(s)

    Updated Methods for Traffic Impact Analysis, Including Evaluation of Innovative Intersection Designs: Volume I—Technical Report

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    In 1992, an Applicant’s Guide and a Reviewer’s Guide to Traffic Impact Analyses to standardize the methodologies for conducting traffic impact analyses (TIAs) in Indiana were developed for the Indiana Department of Transportation (INDOT). The methodologies were meant to help streamline the process of preparing and reviewing TIAs. The methodology is applicable for other transportation and government entities as well. Because 20 years have passed since the publication of the guides, INDOT wished to evaluate how effective the guides have been, determine what in the guides has worked well, revise parts of the guides that have not worked well, and add improvements and changes that have occurred since the guides’ publication. Brief explanations of innovative intersection alternatives such as roundabouts, median U-turns (MUT), restricted-crossing U-turns (RCUT), displaced left-turns (DLT), and quadrant roadways (QR) are provided to increase awareness of these possible designs. Some of the innovative designs were compared against a two-way stop-controlled intersection and a conventional signalized intersection for varying volumes on minor street approaches. The median U-turn design seemed to perform better at higher, more balanced flows whereas the roundabout performed better for unbalanced flows. At times, a development affects roads in more than one jurisdiction. Ideas are presented that may facilitate the inclusion of all affected parties early in the development process to improve communication, address all possible effects of the development and better satisfy all affected parties

    Updated Methods for Traffic Impact Analysis, Including Evaluation of Innovative Intersection Designs: Volume III—Reviewer’s Guide

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    The INDOT Reviewer’s Guide to Traffic Impact Analysis (TIA) is a product of SPR-3605 Updated Methods for Traffic Impact Analysis. It is intended to provide guidance to individuals who are charged with the responsibility to evaluate the Traffic Impact Analysis (TIA) reports submitted to INDOT (or other public agencies). This guide replaces the 1992 Reviewer\u27s Guide for Traffic Impact Studies. The 1992 Guide was essentially an extended version of the 1992 Applicant\u27s Guide to Traffic Impact Studies. This time, the Reviewer’s Guide is written with the knowledge that the Applicant’s Guide is available to both applicants and reviewers. The 2013 Reviewer’s Guide focuses on added information that may help the reviewer assess the TIA report contents

    Magnetic field enhancement of superconductivity in ultra-narrow wires

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    We study the effect of an applied magnetic field on sub-10nm wide MoGe and Nb superconducting wires. We find that magnetic fields can enhance the critical supercurrent at low temperatures, and does so more strongly for narrower wires. We conjecture that magnetic moments are present, but their pair-breaking effect, active at lower magnetic fields, is suppressed by higher fields. The corresponding microscopic theory, which we have developed, quantitatively explains all experimental observations, and suggests that magnetic moments have formed on the wire surfaces.Comment: 4 pages, 3 figures, 1 tabl

    Carbon fibre tips for scanning probe microscopy based on quartz tuning fork force sensors

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    We report the fabrication and the characterization of carbon fibre tips for their use in combined scanning tunnelling and force microscopy based on piezoelectric quartz tuning fork force sensors. We find that the use of carbon fibre tips results in a minimum impact on the dynamics of quartz tuning fork force sensors yielding a high quality factor and consequently a high force gradient sensitivity. This high force sensitivity in combination with high electrical conductivity and oxidation resistance of carbon fibre tips make them very convenient for combined and simultaneous scanning tunnelling microscopy and atomic force microscopy measurements. Interestingly, these tips are quite robust against occasionally occurring tip crashes. An electrochemical fabrication procedure to etch the tips is presented that produces a sub-100 nm apex radius in a reproducible way which can yield high resolution images.Comment: 14 pages, 10 figure

    Fourier-Space Crystallography as Group Cohomology

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    We reformulate Fourier-space crystallography in the language of cohomology of groups. Once the problem is understood as a classification of linear functions on the lattice, restricted by a particular group relation, and identified by gauge transformation, the cohomological description becomes natural. We review Fourier-space crystallography and group cohomology, quote the fact that cohomology is dual to homology, and exhibit several results, previously established for special cases or by intricate calculation, that fall immediately out of the formalism. In particular, we prove that {\it two phase functions are gauge equivalent if and only if they agree on all their gauge-invariant integral linear combinations} and show how to find all these linear combinations systematically.Comment: plain tex, 14 pages (replaced 5/8/01 to include archive preprint number for reference 22

    Long-lived memory for mesoscopic quantum bits

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    We describe a technique to create long-lived quantum memory for quantum bits in mesoscopic systems. Specifically we show that electronic spin coherence can be reversibly mapped onto the collective state of the surrounding nuclei. The coherent transfer can be efficient and fast and it can be used, when combined with standard resonance techniques, to reversibly store coherent superpositions on the time scale of seconds. This method can also allow for ``engineering'' entangled states of nuclear ensembles and efficiently manipulating the stored states. We investigate the feasibility of this method through a detailed analysis of the coherence properties of the system.Comment: 4 pages, 2 figure

    Schrodinger cats and their power for quantum information processing

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    We outline a toolbox comprised of passive optical elements, single photon detection and superpositions of coherent states (Schrodinger cat states). Such a toolbox is a powerful collection of primitives for quantum information processing tasks. We illustrate its use by outlining a proposal for universal quantum computation. We utilize this toolbox for quantum metrology applications, for instance weak force measurements and precise phase estimation. We show in both these cases that a sensitivity at the Heisenberg limit is achievable.Comment: 10 pages, 5 figures; Submitted to a Special Issue of J. Opt. B on "Fluctuations and Noise in Photonics and Quantum Optics" (Herman Haus Memorial Issue

    Precision spectroscopy with two correlated atoms

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    We discuss techniques that allow for long coherence times in laser spectroscopy experiments with two trapped ions. We show that for this purpose not only entangled ions prepared in decoherence-free subspaces can be used but also a pair of ions that are not entangled but subject to the same kind of phase noise. We apply this technique to a measurement of the electric quadrupole moment of the 3d D5/2 state of 40Ca+ and to a measurement of the linewidth of an ultrastable laser exciting a pair of 40Ca+ ions
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