4,434 research outputs found

    Two-way digital driver/receiver uses one set of lines

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    Two-way /bilateral/ digital driver/receiver system using MOS circuits was designed for a multiprocess computer having several subsystems at relatively close locations. The system requires only a single set of communication lines between subsystems, thus achieving lower cost with increased reliability

    Answer Set Planning Under Action Costs

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    Recently, planning based on answer set programming has been proposed as an approach towards realizing declarative planning systems. In this paper, we present the language Kc, which extends the declarative planning language K by action costs. Kc provides the notion of admissible and optimal plans, which are plans whose overall action costs are within a given limit resp. minimum over all plans (i.e., cheapest plans). As we demonstrate, this novel language allows for expressing some nontrivial planning tasks in a declarative way. Furthermore, it can be utilized for representing planning problems under other optimality criteria, such as computing ``shortest'' plans (with the least number of steps), and refinement combinations of cheapest and fastest plans. We study complexity aspects of the language Kc and provide a transformation to logic programs, such that planning problems are solved via answer set programming. Furthermore, we report experimental results on selected problems. Our experience is encouraging that answer set planning may be a valuable approach to expressive planning systems in which intricate planning problems can be naturally specified and solved

    Boundary quantum critical phenomena with entanglement renormalization

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    We extend the formalism of entanglement renormalization to the study of boundary critical phenomena. The multi-scale entanglement renormalization ansatz (MERA), in its scale invariant version, offers a very compact approximation to quantum critical ground states. Here we show that, by adding a boundary to the scale invariant MERA, an accurate approximation to the critical ground state of an infinite chain with a boundary is obtained, from which one can extract boundary scaling operators and their scaling dimensions. Our construction, valid for arbitrary critical systems, produces an effective chain with explicit separation of energy scales that relates to Wilson's RG formulation of the Kondo problem. We test the approach by studying the quantum critical Ising model with free and fixed boundary conditions.Comment: 8 pages, 12 figures, for a related work see arXiv:0912.289

    Simulation of anyons with tensor network algorithms

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    Interacting systems of anyons pose a unique challenge to condensed matter simulations due to their non-trivial exchange statistics. These systems are of great interest as they have the potential for robust universal quantum computation, but numerical tools for studying them are as yet limited. We show how existing tensor network algorithms may be adapted for use with systems of anyons, and demonstrate this process for the 1-D Multi-scale Entanglement Renormalisation Ansatz (MERA). We apply the MERA to infinite chains of interacting Fibonacci anyons, computing their scaling dimensions and local scaling operators. The scaling dimensions obtained are seen to be in agreement with conformal field theory. The techniques developed are applicable to any tensor network algorithm, and the ability to adapt these ansaetze for use on anyonic systems opens the door for numerical simulation of large systems of free and interacting anyons in one and two dimensions.Comment: Fixed typos, matches published version. 16 pages, 21 figures, 4 tables, RevTeX 4-1. For a related work, see arXiv:1006.247

    Safety Performance Evaluation of the Steel Backed Wood Rail to Bridge Rail Transition

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    The safety performance of the Steel Backed Wood Rail to Bridge Rail Transition was evaluated as part of the federally sponsored Guardrail Testing Program II. During this evaluation, which included 5 full-scale vehicle crash tests, a number of modifications were made to improve the safety of the system. The tests were conducted, reported, and evaluated in accordance with requirements specified for guardrail to bridge rail transitions in the National Cooperative Highway Research Program (NCHRP) Report No. 230, Recommended Procedures for the Safety Performance Evaluation of Highway Appurtenances. Upon implementation of the design changes described herein, the performance of the Steel Backed Wood Rail to Bridge Rail Transition was determined to be acceptable according to these guidelines

    GUARDRAIL CUTTING TERMINAL

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    To reduce the danger of bodily harm to occupants of vehicles that leave the roadway, a guardrail system included a guardrail terminal and a guardrail. The guardrail terminal includes cutting means positioned to cut said guardrail as guardrail moves within said guardrail terminal and the guardrail termail moves respect to the guardrail to cut the guardrail when impacted by a vehicle

    First order wetting of rough substrates and quantum unbinding

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    Replica and functional renormalization group methods show that, with short range substrate forces or in strong fluctuation regimes, wetting of a self-affine rough wall in 2D turns first-order as soon as the wall roughness exponent exceeds the anisotropy index of bulk interface fluctuations. Different thresholds apply with long range forces in mean field regimes. For bond-disordered bulk, fixed point stability suggests similar results, which ultimately rely on basic properties of quantum bound states with asymptotically power-law repulsive potentials.Comment: 11 pages, 1 figur
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