1,848 research outputs found
Orientations of hamiltonian cycles in large digraphs
We prove that, with some exceptions, every digraph with n ≥ 9 vertices and at least (n - 1) (n - 2) + 2 arcs contains all orientations of a Hamiltonian cycle
Rb and Rc Crises
The Rb and Rc crises described by Kaoru Hagiwara in hep-ph/9512425 [2] can be resolved by the T-quark mass value of 130 GeV and the αs(MZ) value of 0.106 of the D4 − D5 − E6 model described in hep-ph/9501252 [5] and quant-ph/9503009 [6]. c○1995 Frank D. (Tony) Smith, Jr., Cartersville, Georgia USA1 Introduction. During 1995, precision electroweak data have confirmed the predictions of the Standard Model, with no new physics, with the possible exception of the two observables Rb and Rc. In his recent review, Kaoru Hagiwara [2] has described the situation i
Stochastic simulations of conditional states of partially observed systems, quantum and classical
In a partially observed quantum or classical system the information that we
cannot access results in our description of the system becoming mixed even if
we have perfect initial knowledge. That is, if the system is quantum the
conditional state will be given by a state matrix and if classical
the conditional state will be given by a probability distribution
where is the result of the measurement. Thus to determine the evolution of
this conditional state under continuous-in-time monitoring requires an
expensive numerical calculation. In this paper we demonstrating a numerical
technique based on linear measurement theory that allows us to determine the
conditional state using only pure states. That is, our technique reduces the
problem size by a factor of , the number of basis states for the system.
Furthermore we show that our method can be applied to joint classical and
quantum systems as arises in modeling realistic measurement.Comment: 16 pages, 11 figure
Frequency Tracking and Parameter Estimation for Robust Quantum State-Estimation
In this paper we consider the problem of tracking the state of a quantum
system via a continuous measurement. If the system Hamiltonian is known
precisely, this merely requires integrating the appropriate stochastic master
equation. However, even a small error in the assumed Hamiltonian can render
this approach useless. The natural answer to this problem is to include the
parameters of the Hamiltonian as part of the estimation problem, and the full
Bayesian solution to this task provides a state-estimate that is robust against
uncertainties. However, this approach requires considerable computational
overhead. Here we consider a single qubit in which the Hamiltonian contains a
single unknown parameter. We show that classical frequency estimation
techniques greatly reduce the computational overhead associated with Bayesian
estimation and provide accurate estimates for the qubit frequencyComment: 6 figures, 13 page
ANT SPECIES DIVERSITY AND COMPOSITION AT MLINGANO MANGO ORCHARD IN TANZANIA
ABSTRACT: Ants are major decomposers and they are sensitive to any human influence in our environment. Presence or absence of ants in cropland habitat is resulted from alteration of forest habitat into cropland. Ant's species diversity in mango orchard was considered as an important biodiversity indicator due to alteration of the primary forest into cropland habitat. Ants were sampled from mango trees searching species of ants from tree bases to 2M high. Dental rolls with 10% sugar as attractant bait were also used to attract ground preference of ant species. Attractant bait was placed on a tree base for 30 minutes and thereafter inspected for data collection. This study has revealed that ant species composition in mango orchard varies according to cropping system. Dominance of species was Crematogaster followed by Pheidole megacephala and the least was Oecopyhlla longinoda ants. Comparison of species composition revealed that there were significant differences. Species with low representative individuals were considered as extinct or rare species. The intended study was carried out at Mlingano mango orchard with the aim to determine the ant's species diversity and composition. The results from this work will help in developing sustainable biodiversity conservation programmes as well as for future research
UAV photogrammetry and structure from motion to assess calving dynamics at Store Glacier, a large outlet draining the Greenland ice sheet
This study presents the application of a cost-effective, unmanned aerial
vehicle (UAV) to investigate calving dynamics at a major marine-terminating
outlet glacier draining the western sector of the Greenland ice sheet. The
UAV was flown over Store Glacier on three sorties during summer 2013 and
acquired over 2000 overlapping, geotagged images of the calving front at an
~40 cm ground sampling distance. Stereo-photogrammetry
applied to these images enabled the extraction of high-resolution digital elevation models (DEMs) with vertical accuracies of ± 1.9 m which were used
to quantify glaciological processes from early July to late August 2013. The
central zone of the calving front advanced by ~500 m, whilst
the lateral margins remained stable. The orientation of crevasses and the
surface velocity field derived from feature tracking indicates that lateral
drag is the primary resistive force and that ice flow varies across the
calving front from 2.5 m d−1 at the margins to in excess of
16 m d−1 at the centreline. Ice flux through the calving front is 3.8 × 107 m3 d−1,
equivalent to 13.9 Gt a−1 and comparable to
flux-gate estimates of Store Glacier's annual discharge. Water-filled
crevasses were present throughout the observation period but covered a
limited area of between 0.025 and 0.24% of the terminus and did not appear
to exert any significant control over fracture or calving. We conclude that
the use of repeat UAV surveys coupled with the processing techniques
outlined in this paper have great potential for elucidating the complex
frontal dynamics that characterise large calving outlet glaciers
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