9,091 research outputs found

    Analytical method for designing grating compensated dispersion-managed soliton systems

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    This paper was published in Journal of Optical Society of America B and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.opticsinfobase.org/abstract.cfm?URI=JOSAB-21-4-706. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law. © 2004 The Optical Society.Peer reviewedPublisher PD

    BIRD CLASSIFICATION IN NOISY ENVIRONMENTS: THEORY, RESULTS AND COMPARATIVE STUDIES

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    Bird classification plays an important role in minimizing collisions between birds and aircraft. It is a challenging task to perform the sound-based classification correctly in a noisy environment. This paper addresses robust techniques that can improve the classification of bird in noisy environments. A complete recognition system is described and evaluated on a bird sound database containing 1547 bird sound files, with 11 bird species. Two types of features were extracted from the sound files: Mel Frequency Cepstral Coefficient (Mfcc) and RelAtive SpecTrAl (RASTA). Also, two statistical classifiers were developed using Gaussian Mixture Models (GMM) and Hidden Markov Models (HMM), respectively. The performance of these features and models are compared. Very good recognition rates (97% for clean data and 92% for 5dB signal-to-noise ratios) have been achieved when proper feature and model were selected

    BIRD CLASSIFICATION IN NOISY ENVIRONMENTS: THEORY, RESULTS AND COMPARATIVE STUDIES

    Get PDF
    Bird classification plays an important role in minimizing collisions between birds and aircraft. It is a challenging task to perform the sound-based classification correctly in a noisy environment. This paper addresses robust techniques that can improve the classification of bird in noisy environments. A complete recognition system is described and evaluated on a bird sound database containing 1547 bird sound files, with 11 bird species. Two types of features were extracted from the sound files: Mel Frequency Cepstral Coefficient (Mfcc) and RelAtive SpecTrAl (RASTA). Also, two statistical classifiers were developed using Gaussian Mixture Models (GMM) and Hidden Markov Models (HMM), respectively. The performance of these features and models are compared. Very good recognition rates (97% for clean data and 92% for 5dB signal-to-noise ratios) have been achieved when proper feature and model were selected

    The Radon Monitoring System in Daya Bay Reactor Neutrino Experiment

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    We developed a highly sensitive, reliable and portable automatic system (H3^{3}) to monitor the radon concentration of the underground experimental halls of the Daya Bay Reactor Neutrino Experiment. H3^{3} is able to measure radon concentration with a statistical error less than 10\% in a 1-hour measurement of dehumidified air (R.H. 5\% at 25^{\circ}C) with radon concentration as low as 50 Bq/m3^{3}. This is achieved by using a large radon progeny collection chamber, semiconductor α\alpha-particle detector with high energy resolution, improved electronics and software. The integrated radon monitoring system is highly customizable to operate in different run modes at scheduled times and can be controlled remotely to sample radon in ambient air or in water from the water pools where the antineutrino detectors are being housed. The radon monitoring system has been running in the three experimental halls of the Daya Bay Reactor Neutrino Experiment since November 2013

    Graft Suturing for Lenticule Dislocation after Descemet Stripping Automated Endothelial Keratoplasty

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    Purpose: To report the mid-term outcomes of graft suturing in a patient with lenticule dislocation after Descemet stripping automated endothelial keratoplasty (DSAEK). Case Report: A 78-year old woman was found to have graft dislocation involving the nasal half of the cornea after uneventful DSAEK. Graft repositioning, refilling the anterior chamber with air, and placement of four full-thickness 10/0 nylon sutures over the detached area were performed two weeks after the initial surgery. The sutures were removed 6 weeks later. Serial specular microscopy and anterior segment optical coherence tomography were performed. At 18 months, there was good lenticule apposition and a clear graft. Conclusion: Anchoring sutures seem to be effective for management of graft detachment following DSAEK

    Heisenberg-picture approach to the exact quantum motion of a time-dependent forced harmonic oscillator

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    In the Heisenberg picture, the generalized invariant and exact quantum motions are found for a time-dependent forced harmonic oscillator. We find the eigenstate and the coherent state of the invariant and show that the dispersions of these quantum states do not depend on the external force. Our formalism is applied to several interesting cases.Comment: 15 pages, two eps files, to appear in Phys. Rev. A 53 (6) (1996

    Halo Sampling, Local Bias and Loop Corrections

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    We develop a new test of local bias, by constructing a locally biased halo density field from sampling the dark matter-halo distribution. Our test differs from conventional tests in that it preserves the full scatter in the bias relation and it does not rely on perturbation theory. We put forward that bias parameters obtained using a smoothing scale R can only be applied to computing the halo power spectrum at scales k ~ 1/R. Our calculations can automatically include the running of bias parameters and give vanishingly small loop corrections at low-k. Our proposal results in much better agreement of the sampling and perturbation theory results with simulations. In particular, unlike the standard interpretation of local bias in the literature, our treatment of local bias does not generate a constant power in the low-k limit. We search for extra noise in the Poisson corrected halo power spectrum at wavenumbers below its turn-over and find no evidence of significant positive noise (as predicted by the standard interpretation) while we find evidence of negative noise coming from halo exclusion for very massive halos. Using perturbation theory and our non-perturbative sampling technique we also demonstrate that nonlocal bias effects discovered recently in simulations impact the power spectrum only at the few percent level in the weakly nonlinear regime.Comment: 25 pages, 14 figures; V2: significant revision including more details about halo exclusion and low-k noise. Conclusions unchange

    Addendum to a Case Study on Using Spreadsheets to Facilitate Committee Discussions and to Assist Committee Decisions in an Academic Setting: Graduate Admissions of Applicants with Degrees from Chinese Universities

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    This paper updates an Excel-based example in a recent case study published in Spreadsheets in Education. The original example was intended to assist graduate admission committees outside China in assessing the academic quality of individual Chinese universities in the application files. China being the top country of origin of international students in many English-speaking countries, the official implementation of China's Double First-Class Initiative (DFCI) in 2017, aimed at improving the global recognition of Chinese universities, has provided valuable additional information for such committees to consider. The additional information includes not only the names of all designated universities in two different categories, but also the corresponding discipline or disciplines in each university for existing strengths or future potentials. As an addendum to the original example, this paper first justifies the update. It then shows how publicly available information under the DFCI can be organized in an Excel setting for improving the original example

    Using Spreadsheets to Facilitate Committee Discussions and to Assist Committee Decisions in an Academic Setting: A Case Study

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    This paper is a case study on using spreadsheet tools to reduce the reliance on various manual tasks for committee work in an academic setting. Four types of tasks are covered. One of them is to establish collective preference rankings of candidates; it pertains to various committees. The remaining types are for graduate admissions. The coverage includes conversions of alternative test scores as achieved by individual applicants, a special case of university quality assessments, and record keeping in a rolling admission process. It is hoped that this paper can serve as a catalyst to generate interests among readers in exploring innovative ways to use spreadsheet tools in their own work settings. This paper is a case study on using spreadsheet tools to reduce the reliance on various manual tasks for committee work in an academic setting. Four types of tasks are covered. One of them is to establish collective preference rankings of candidates; it pertains to various committees. The remaining types are for graduate admissions. The coverage includes conversions of alternative test scores as achieved by individual applicants, a special case of university quality assessments, and record keeping in a rolling admission process. It is hoped that this paper can serve as a catalyst to generate interests among readers in exploring innovative ways to use spreadsheet tools in their own work settings
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