1,797 research outputs found

    Digital Measurement of Differential Time Delay of Pseudo Random Coded Signals Scientific Report No. 6

    Get PDF
    Digital measurement of differential time delay of pseudorandom coded signal

    On the time required for group multiplication

    Get PDF
    Group multiplication of logical elements by networks having limited inputs and unit delay in computing output functio

    A Class of Codes for Multiple-access Satellite Communication Systems

    Get PDF
    Codes for multiple-access communication satellite systems using time-frequency multiplexin

    Formulas vs. Circuits for Small Distance Connectivity

    Full text link
    We give the first super-polynomial separation in the power of bounded-depth boolean formulas vs. circuits. Specifically, we consider the problem Distance k(n)k(n) Connectivity, which asks whether two specified nodes in a graph of size nn are connected by a path of length at most k(n)k(n). This problem is solvable (by the recursive doubling technique) on {\bf circuits} of depth O(logk)O(\log k) and size O(kn3)O(kn^3). In contrast, we show that solving this problem on {\bf formulas} of depth logn/(loglogn)O(1)\log n/(\log\log n)^{O(1)} requires size nΩ(logk)n^{\Omega(\log k)} for all k(n)loglognk(n) \leq \log\log n. As corollaries: (i) It follows that polynomial-size circuits for Distance k(n)k(n) Connectivity require depth Ω(logk)\Omega(\log k) for all k(n)loglognk(n) \leq \log\log n. This matches the upper bound from recursive doubling and improves a previous Ω(loglogk)\Omega(\log\log k) lower bound of Beame, Pitassi and Impagliazzo [BIP98]. (ii) We get a tight lower bound of sΩ(d)s^{\Omega(d)} on the size required to simulate size-ss depth-dd circuits by depth-dd formulas for all s(n)=nO(1)s(n) = n^{O(1)} and d(n)logloglognd(n) \leq \log\log\log n. No lower bound better than sΩ(1)s^{\Omega(1)} was previously known for any d(n)O(1)d(n) \nleq O(1). Our proof technique is centered on a new notion of pathset complexity, which roughly speaking measures the minimum cost of constructing a set of (partial) paths in a universe of size nn via the operations of union and relational join, subject to certain density constraints. Half of our proof shows that bounded-depth formulas solving Distance k(n)k(n) Connectivity imply upper bounds on pathset complexity. The other half is a combinatorial lower bound on pathset complexity

    A Note on W Production at HERA

    Full text link
    We discuss W boson production at HERA including NLO QCD corrections.Comment: 2 pages, latex, 2 figures, Contribution to the 3rd UK Phenomenology Workshop on HERA Physics, Durham, 20-25 Sep. 199

    Operant conditioning in older adults with Alzheimer\u27s disease

    Get PDF
    Behavioral interventions are commonly implemented to manage agitation in older adults with dementia. However, the extent to which operant conditioning can occur in this population is unclear. The present study used a button-pressing task to evaluate the sensitivity of the responding of individuals with probable Alzheimer\u27s disease to changes in schedules of reinforcement. Results indicate that operant conditioning can occur in older adults with AD. Specifically, three participants with AD exhibited responding that was highly sensitive to a transition from a fixed interval schedule to an extinction schedule. One participant\u27s responding was sensitive to a more subtle transition. Comparison data is presented from older controls and college students. Clinical implications of findings and suggestions for future research are presented

    Squark and Gluino Production at Hadron Colliders

    Get PDF
    We have determined the theoretical predictions for the cross-sections of squark and gluino production at \ppb and pppp colliders (Tevatron and LHC) in next-to-leading order of supersymmetric QCD. By reducing the dependence on the renormalization/factorization scale considerably, the theoretically predicted values for the cross-sections are much more stable if these higher-order corrections are implemented. If squarks and gluinos are discovered, this improved stability translates into a reduced error on the masses, as extracted experimentally from the size of the production cross-sections. The cross-sections increase significantly if the next-to-leading order corrections are included at a renormalization/factorization scale near the average mass of the produced massive particles. This rise results in improved lower bounds on squark and gluino masses. By contrast, the shape of the transverse-momentum and rapidity distributions remains nearly unchanged when the next-to-leading order corrections are included.Comment: 60 pages, Latex2e, 24 figures (uses epsfig.sty

    Higgs radiation off quarks in supersymmetric theories at e^+e^- colliders

    Get PDF
    Yukawa couplings between Higgs bosons and quarks in supersymmetric theories can be measured in the processes e^+e^- -> Q Qbar + Higgs. We have determined the cross sections of these processes in the minimal supersymmetric model including the complete set of next-to-leading order QCD corrections for all channels.Comment: 12 pages, latex, 3 figure

    Differential Pollen‐Tube Growth Rates And Nonrandom Fertilization In Hibiscus Moscheutos (Malvaceae)

    Full text link
    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141504/1/ajb212608.pd
    corecore