59,416 research outputs found

    Quantum Gauss Jordan Elimination

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    In this paper we construct the Quantum Gau\ss Jordan Elimination (QGJE) Algorithm and estimate the complexity time of computation of Reduced Row Echelon Form (RREF) of an N×NN\times N matrix using QGJE procedure. The main theorem asserts that QGJE has computation time of order 2N/22^{N/2}

    Microlensing path parametrization for Earth-like Exoplanet detection around solar mass stars

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    We propose a new parametrization of the impact parameter u0 and impact angle {\alpha} for microlensing systems composed by an Earth-like Exoplanet around a Solar mass Star at 1 AU. We present the caustic topology of such system, as well as the related light curves generated by using such a new parametrization. Based on the same density of points and accuracy of regular methods, we obtain results 5 times faster for discovering Earth-like exoplanet. In this big data revolution of photometric astronomy, our method will impact future missions like WFIRST (NASA) and Euclid (ESA) and they data pipelines, providing a rapid and deep detection of exoplanets for this specific class of microlensing event that might otherwise be lost.Comment: 8 pages, 7 figures, accepted to be published in The Astronomical Journa

    Comparison of Visual Analog Pain Score Reported to Physician vs Nurse in Nonoperatively Treated Foot and Ankle Patients

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    Background: Patient reported outcome measures (PROMs) are taking a more prominent role in Orthopedics as health care seeks to define treatment outcomes. The Visual Analogue Scale (VAS) is considered a reliable measure of acute pain. A previous study found that operative candidates’ VAS pain score was significantly higher when reported to the surgeon compared to the nurse. This study’s aim is to examine whether this phenomenon occurs in nonoperative patients. We hypothesize that patients’ VAS scores reported to the surgeon and a nurse will be the same Methods: This study is a retrospective cohort of 201 consecutive nonoperative patients treated by a single surgeon. Patients were asked to rate pain intensity by a nurse followed by the surgeon using a horizontal VAS, 0 “no pain” to 10 worst pain”. Differences in reported pain levels were compared with data from the previous cohort of 201 consecutive operative patients. Results: The mean VAS score reported to the nurse was 3.2 whereas the mean VAS score reported to the surgeon was 4.2 (p\u3c.001). The mean difference in VAS scores reported for operative patients was 2.9, whereas the mean difference for nonoperative patients was 1.0 (p \u3c .001). Conclusion: This study found statistically significant differences between VAS scores reported to the surgeon versus the nurse in nonoperative patients which support the trend found in our previous study, where operative patients reported significantly higher scores to the surgeon. The mean difference between reported pain scores is significantly higher for operative patients compared to nonoperative patients

    Assessing Economic Complexity with Input-Output Based Measures

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    Economic complexity can be defined as the level of interdependence between the component parts of an economy. In input-output systems, intersectoral connectedness is a crucial feature of analysis, and there are many different methods for measuring it. Most of the measures, however, have drawbacks that prevent them from being used as a good indicator of economic complexity, because they were not explicitly made with this purpose in mind. In this paper, we present, discuss and compare empirically different indexes of economic complexity as intersectoral connectedness, using the interindustry tables of several OECD countries.input-output analysis; intersectoral connectedness; economic complexity

    Two novel evolutionary formulations of the graph coloring problem

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    We introduce two novel evolutionary formulations of the problem of coloring the nodes of a graph. The first formulation is based on the relationship that exists between a graph's chromatic number and its acyclic orientations. It views such orientations as individuals and evolves them with the aid of evolutionary operators that are very heavily based on the structure of the graph and its acyclic orientations. The second formulation, unlike the first one, does not tackle one graph at a time, but rather aims at evolving a `program' to color all graphs belonging to a class whose members all have the same number of nodes and other common attributes. The heuristics that result from these formulations have been tested on some of the Second DIMACS Implementation Challenge benchmark graphs, and have been found to be competitive when compared to the several other heuristics that have also been tested on those graphs.Comment: To appear in Journal of Combinatorial Optimizatio
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