3,523 research outputs found

    A pp-adic RanSaC algorithm for stereo vision using Hensel lifting

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    A pp-adic variation of the Ran(dom) Sa(mple) C(onsensus) method for solving the relative pose problem in stereo vision is developped. From two 2-adically encoded images a random sample of five pairs of corresponding points is taken, and the equations for the essential matrix are solved by lifting solutions modulo 2 to the 2-adic integers. A recently devised pp-adic hierarchical classification algorithm imitating the known LBG quantisation method classifies the solutions for all the samples after having determined the number of clusters using the known intra-inter validity of clusterings. In the successful case, a cluster ranking will determine the cluster containing a 2-adic approximation to the "true" solution of the problem.Comment: 15 pages; typos removed, abstract changed, computation error remove

    Frequency down conversion through Bose condensation of light

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    We propose an experimental set up allowing to convert an input light of wavelengths about 12μm1-2 \mu m into an output light of a lower frequency. The basic principle of operating relies on the nonlinear optical properties exhibited by a microcavity filled with glass. The light inside this material behaves like a 2D interacting Bose gas susceptible to thermalise and create a quasi-condensate. Extension of this setup to a photonic bandgap material (fiber grating) allows the light to behave like a 3D Bose gas leading, after thermalisation, to the formation of a Bose condensate. Theoretical estimations show that a conversion of 1μm1 \mu m into 1.5μm1.5 \mu m is achieved with an input pulse of about 1ns1 ns with a peak power of 103W10^3 W, using a fiber grating containing an integrated cavity of size about 500μm×100μm2500 \mu m \times 100 \mu m^2.Comment: 4 pages, 1 figure

    Exploring How Counselor Education Programs Support Site Supervisors

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    CACREP standards require counselor education programs to provide site supervisors with orientation, consultation, and professional development opportunities (PD). Using a nonexperimental descriptive design, we collected data from a national sample of CACREP-accredited programs (N=46, 13.3% response rate) via an online descriptive survey to explore how programs provide such opportunities to site supervisors. The survey contained open-ended and multiple-choice items addressing orientation, consultation, PD, and participants’ opinions on how their program addressed the three domains. We analyzed numerical data using descriptive statistics and open-ended responses using content analysis. We found that most programs offered orientation, consultation, and PD, though site supervisor engagement and methods of implementation varied considerably. Implications for research and practice are discussed in light of the findings

    Amplification of High-Order Rainbows of a Cylinder with an Elliptical Cross Section

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    The intensity of high-order rainbows for normally incident light and certain rotation angles of a cylinder with an elliptical cross section is greatly amplified with respect to the intensity for a circular cross-sectional cylinder. The amplification is due to a number of the internal reflections occurring past the critical angle for total internal reflection, and the effect is especially strong for odd-order rainbows, beginning with the third order. Experimentally, the fourth-and the fifth-order rainbows of a nearly elliptical cross-sectional glass rod were observed and analyzed. (C) 1998 Optical Society of America

    Sarcoidosis: Hiding in Plain Sight

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    Introduction: Sarcoidosis is a systemic disease that can masquerade as many conditions. Due to its often patchy distribution, myocardial biopsy is only ∼30% sensitive. Herein we present a case of sarcoidosis diagnosed from an extra-cardiac biopsy years after the onset of cardiomyopathy. Case Report: A 54 year old man initially presented with dyspnea and fatigue due to new onset HFrEF of 20%. He had a significant family history of SCD. His workup revealed non-obstructive CAD, a myxomatous mitral valve with bileaflet prolapse and moderate regurgitation, and a cystic structure attached to the tricuspid valve. Given his frequent ventricular ectopy, he was discharged on guideline therapy for HFrEF and a wearable cardioverter defibrillator. Genetic testing for dilated cardiomyopathies revealed EYA4 and TTN variants of unknown significance. A cardiac MRI a few months later demonstrated no abnormal late gadolinium enhancement and persistent systolic dysfunction, so he underwent AICD implant. His course was further complicated by recurrent admissions for supraventricular and ventricular tachyarrhythmias. A cardiopulmonary exercise stress test demonstrated low-risk results. Further evaluation noted prolonged AV conduction. A RHC revealed mild post-capillary pulmonary hypertension and a mildly decreased cardiac index at 2.01 L/min/m2. Months later, he underwent CRT-D upgrade. He started improving functionally until he developed left eyelid swelling, initially thought to be lymphoma. An orbital biopsy revealed non-caseating granulomas. A PET/CT demonstrated FDG uptake within subcarinal lymph nodes but no cardiac uptake. Initially he declined immunomodulatory therapy, but as his symptoms worsened, he started corticosteroids and transitioned to mycophenolate mofetil due to intolerance of methotrexate. Due to disease progression on repeat FDG-PET, he was switched to infliximab. The diagnosis of sarcoidosis can be difficult due to its variable presentation, including heart block, heart failure, ventricular arrhythmias and sudden cardiac death. Cardiac involvement occurs in 25% of cases. Our case was complicated by a cMRI that was negative for cardiac involvement, which emphasizes the importance of complimentary inflammatory imaging with FDG-PET. A multidisciplinary approach is needed that engages sarcoid specialists for earlier diagnosis to ensure rapid initiation of therapy to reduce end-organ dysfunction
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