542 research outputs found

    Optical Music Recognition: State of the Art and Major Challenges

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    Optical Music Recognition (OMR) is concerned with transcribing sheet music into a machine-readable format. The transcribed copy should allow musicians to compose, play and edit music by taking a picture of a music sheet. Complete transcription of sheet music would also enable more efficient archival. OMR facilitates examining sheet music statistically or searching for patterns of notations, thus helping use cases in digital musicology too. Recently, there has been a shift in OMR from using conventional computer vision techniques towards a deep learning approach. In this paper, we review relevant works in OMR, including fundamental methods and significant outcomes, and highlight different stages of the OMR pipeline. These stages often lack standard input and output representation and standardised evaluation. Therefore, comparing different approaches and evaluating the impact of different processing methods can become rather complex. This paper provides recommendations for future work, addressing some of the highlighted issues and represents a position in furthering this important field of research

    Integrated impedance bridge for absolute capacitance measurements at cryogenic temperatures and finite magnetic fields

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    We developed an impedance bridge that operates at cryogenic temperatures (down to 60 mK) and in perpendicular magnetic fields up to at least 12 T. This is achieved by mounting a GaAs HEMT amplifier perpendicular to a printed circuit board containing the device under test and thereby parallel to the magnetic field. The measured amplitude and phase of the output signal allows for the separation of the total impedance into an absolute capacitance and a resistance. Through a detailed noise characterization, we find that the best resolution is obtained when operating the HEMT amplifier at the highest gain. We obtained a resolution in the absolute capacitance of 6.4~aF/Hz/\sqrt{\textrm{Hz}} at 77 K on a comb-drive actuator, while maintaining a small excitation amplitude of 15~kBT/ek_\text{B} T/e. We show the magnetic field functionality of our impedance bridge by measuring the quantum Hall plateaus of a top-gated hBN/graphene/hBN heterostructure at 60~mK with a probe signal of 12.8~kBT/ek_\text{B} T/e.Comment: 7 pages, 5 figure

    Improved Concretes for Corrosion Resistance

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    DTFH61-93-C-0028A major cause of concrete deterioration on bridge structures is the corrosion of the embedded steel reinforcement. In response to the continued problem of corrosion, the Federal Highway Administration (FHWA) initiated this research aimed at (1) quantifying the corrosive conditions fostering concrete bridge deterioration and (2) identifying concrete materials which consistently provide superior performance when used in bridge applications. The experimental phase of this research project was divided into three tasks: Task A - Corrosive Environment Studies, Task B - Concrete Chemical and Physical Properties, and Task C - Long-Term Corrosion Performance. This Interim Report reviews the results of Tasks A and B and provides recommendations for performing Task C. In Task A, laboratory experiments were conducted to characterize the corrosive environment and to establish boundary conditions for environmental variables of moisture content, chloride concentration, and temperature. Special test specimen design and test procedures were developed to permit uniform chloride diffusion to the steel surface. A full factorial matrix of experiments was performed for three levels each of chloride concentration, relative humidity, and temperature. A regression model was developed to predict corrosion rate and corrosion potential as a function of environment for two different concretes. In Task B, experiments were performed to identify the chemical components of concretes and to determine how they effect corrosion induced deterioration of concrete structures. The dependent variables of interest in examining corrosion induced deterioration of concrete are corrosion rate, corrosion potential, chloride permeability, electrical resistivity, and physical properties. The independent concrete design mix variables examined included: water-cement ratio, air content, coarse aggregate type, fine aggregate type, mineral admixture, and cement type. Because of the large number of independent variables and the number of levels of interest for the variables, an optimized experimental design was developed to permit the estimate of the main-effect terms for each independent variable. Models were developed to predict the effect of the independent variables on corrosion rate and corrosion potential in each of two environments, chloride permeability, resistivity, and compressive strength. The data developed were used to make recommendations for the concretes to be tested in the Task C long-term experiments

    G-BOOKシステム構成技術とトヨタ・カーマルチメディアの方向性

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    1. 本研究と本稿について 2. G-BOOK車載用システムの概要 3. DCMとCDMA2000 4. 車両位置情報検索とgpsOne 5. Windows CE for Automotive 6. GBIN (G-BOOK Information Network) 7. G-BOOK車載用システムの課題 8. 本研究のまとめと今後の研究

    Ultrafast voltage sampling using single-electron wavepackets

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    We demonstrate an ultrafast voltage sampling technique using a stream of electron wavepackets. Electrons are emitted from a single-electron pump and travel through electron waveguides towards a detector potential barrier. Our electrons sample an instantaneous voltage on the gate upon arrival at the detector barrier. Fast sampling is achieved by minimising the duration that the electrons interact with the barrier, which can be made as small as a few picoseconds. The value of the instan- taneous voltage can be determined by varying the gate voltage to match the barrier height to the electron energy, which is used as a stable reference. The test waveform can be reconstructed by shifting the electron arrival time against it. Although we find that the our current system is limited by the experimental line bandwidth to 12–18 GHz, we argue that this method has scope to increase the bandwidth of voltage sampling to 100 GHz and beyond

    Optical mapping apparatus with adjustable depth resolution and multiple functionality

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    WO 2004002298 A1 The present invention relates to a multiple channel optical mapping apparatus which can deliver one or simultaneously at least two images of different depth resolutions or sequentially, images with different depth resolutions, or a combination of these images, or a single image with adjustable depth resolution. The multiple channels could be either multiple confocal channel and one or two optical coherence tomography channel, or two optical coherence tomogrraphy channels, or two confocal channels. The channels, either OCT or confocal can operate on the same wavelength or on different wavelengths. The apparatus can display both transversal as well as longitudinal images in an object, particularly the eye

    Identification and quantification of microplastics in wastewater using focal plane array-based reflectance micro-FT-IR imaging

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    Microplastics (<5 mm) have been documented in environmental samples on a global scale. While these pollutants may enter aquatic environments via wastewater treatment facilities, the abundance of microplastics in these matrices has not been investigated. Although efficient methods for the analysis of microplastics in sediment samples and marine organisms have been published, no methods have been developed for detecting these pollutants within organic-rich wastewater samples. In addition, there is no standardized method for analyzing microplastics isolated from environmental samples. In many cases, part of the identification protocol relies on visual selection before analysis, which is open to bias. In order to address this, a new method for the analysis of microplastics in wastewater was developed. A pretreatment step using 30% hydrogen peroxide (H2O2) was employed to remove biogenic material, and focal plane array (FPA)-based reflectance micro-Fourier-transform (FT-IR) imaging was shown to successfully image and identify different microplastic types (polyethylene, polypropylene, nylon-6, polyvinyl chloride, polystyrene). Microplastic-spiked wastewater samples were used to validate the methodology, resulting in a robust protocol which was nonselective and reproducible (the overall success identification rate was 98.33%). The use of FPA-based micro-FT-IR spectroscopy also provides a considerable reduction in analysis time compared with previous methods, since samples that could take several days to be mapped using a single-element detector can now be imaged in less than 9 h (circular filter with a diameter of 47 mm). This method for identifying and quantifying microplastics in wastewater is likely to provide an essential tool for further research into the pathways by which microplastics enter the environment.This work is funded by a NERC (Natural Environment Research Council) CASE studentship (NE/K007521/1) with contribution from industrial partner Fera Science Ltd., United Kingdom. The authors would like to thank Peter Vale, from Severn Trent Water Ltd, for providing access to and additionally Ashley Howkins (Brunel University London) for providing travel and assistance with the sampling of the Severn Trent wastewater treatment plant in Derbyshire, UK. We are grateful to Emma Bradley and Chris Sinclair for providing helpful suggestions for our research

    Better prognosis in females with severe COVID-19 pneumonia: possible role of inflammation as potential mediator.

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    Objectives: Sex differences in COVID-19 severity and mortality have been described. Key aims of this analysis were to compare the risk of invasive mechanical ventilation (IMV) and mortality by sex and to explore whether variation in specific biomarkers could mediate this difference. Methods: This was a retrospective, observational cohort study among patients with severe COVID- 19 pneumonia. A survival analysis was conducted to compare time to the composite endpoint of IMV or death by sex. Interaction was formally tested to compare the risk difference by sex in subsets. Mediation analysis with a binary endpoint IMV or death (yes/no) by end of follow-up for a number of inflammation/coagulation biomarkers in the context of counterfactual prediction was also conducted. Results: Among 415 patients, 134 were females (32%) and 281 males (67%), median age 66 years (IQR 54-77). At admission, females showed a significantly less severe clinical and respiratory profiles with a higher PaO2/FiO2 (254 mmHg vs 191 mmHg; p=0.023). By 28 days from admission, 49.2% (95% CI: 39.6-58.9%) of males vs. 31.7% (17.9-45.4%) of females underwent IMV or death (log-rank pvalue&lt;0.0001) and this amounted to a difference in HR of 0.40 (0.26-0.63, p=0.0001). The AUC in Creactive protein (CRP) over the study period appeared to explain 85% of this difference in risk by sex. Conclusions: Our analysis confirms a difference in the risk of COVID-19 clinical progression by sex and provides a hypothesis for potential mechanisms leading to this. CRP showed a predominant role to mediate the difference in risk by sex
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