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  • 11
    Publication Date: 2016-06-18
    Description: Fault diagnosis is important for the maintenance of rotating machinery. The detection of faults and fault patterns is a challenging part of machinery fault diagnosis. To tackle this problem, a model for deep statistical feature learning from vibration measurements of rotating machinery is presented in this paper. Vibration sensor signals collected from rotating mechanical systems are represented in the time, frequency, and time-frequency domains, each of which is then used to produce a statistical feature set. For learning statistical features, real-value Gaussian-Bernoulli restricted Boltzmann machines (GRBMs) are stacked to develop a Gaussian-Bernoulli deep Boltzmann machine (GDBM). The suggested approach is applied as a deep statistical feature learning tool for both gearbox and bearing systems. The fault classification performances in experiments using this approach are 95.17% for the gearbox, and 91.75% for the bearing system. The proposed approach is compared to such standard methods as a support vector machine, GRBM and a combination model. In experiments, the best fault classification rate was detected using the proposed model. The results show that deep learning with statistical feature extraction has an essential improvement potential for diagnosing rotating machinery faults.
    Electronic ISSN: 1424-8220
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Published by MDPI Publishing
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  • 12
    Publication Date: 2015-05-20
    Description: The research on calculation of torque and drag in highly deviated wells has demonstrated a significant gap against oil exploration and development; with the increasingly rigorous situation, the drill string dynamics and the contact or friction of drill pipe with borehole wall under the drill string action of dynamic need more attention and urgent research work. Based on full-hole system dynamics, three-dimensional nonlinear dynamic model and dynamic torque and drag model were established in highly deviated well by using the finite element method. An application of analyzing typical torque and drag problems presented here provides a means to more accurate description of the contact relation between drill string and wellbore. The results show that those models established in this paper have complete adaptability for a complex three-dimensional borehole trajectory. For the actual well application, it will help to evaluate security performance of drill string in complex working conditions.
    Print ISSN: 1024-123X
    Electronic ISSN: 1563-5147
    Topics: Mathematics , Technology
    Published by Hindawi
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  • 13
    Publication Date: 2015-07-09
    Description: Background: Dry eye syndrome (DES) is one of the key clinical features and possibly an early clinical presentation of Sjögren’s syndrome (SS). We explore DES prevalence and assess the likelihood of DES patients to develop SS in Taiwan through the National Health Insurance Research Database (NHIRD). Methods: Through a cohort comparison study, longitudinal data from the NHIRD (2000 to 2008) in Taiwan was used to probe the prevalence of DES and the odds that DES patients would later develop SS. Results: The prevalence of DES in the present study is 4.87%. The incidence rates of developing SS were 4.8% for the DES group and 1.5% for comparison group. The median age and interquartile range of DES and comparison patients was 49.8 (10) and 48.7 (15) years old, respectively. The crude hazard ratio (with 95% confidence interval) for DES patients to develop SS was 3.13 (3.10–3.50) for the DES group, and the adjusted hazard ratio (with 95% confidence interval) was 3.64 (3.43–3.87). The observation period and interquartile range for DES and comparison patients to develop SS later were 1418 (781–2316) versus 1641 (971–2512) days respectively. Conclusions: DES patients carried a higher risk for developing SS (hazard ratio 3.13) and presented for SS 3.88 years earlier than comparison group patients in this study.
    Print ISSN: 1661-7827
    Electronic ISSN: 1660-4601
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Published by MDPI Publishing
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  • 14
    Publication Date: 2012-04-16
    Description: Protein arginine methylation regulates a broad array of cellular processes. SERBP1 implicated in tumor progression through its putative involvement in the plaminogen activator protease cascade, is an RNA binding protein containing an RG-rich domain and an RGG box domain that might be methylated by protein arginine N-methyltransferases (PRMTs). Asymmetric dimethylarginine (aDMA) was detected in SERBP1 and an indirect methyltransferase inhibitor adenosine dialdehyde (AdOx) significantly reduced the methylation signals. Arginines in the middle RG and C-terminal RGG region of SERBP1 are methylated based on the analyses of different deletion constructs. The predominant type I protein arginine methyltransferase PRMT1 co-immunoprecipitated with SERBP1 and the level of bound PRMT1 decreased upon the addition of AdOx. Recombinant PRMT1 methylated SERBP1 and knockdown of PRMT1 significantly reduced the aDMA level of SERBP1, indicating that SERBP1 is specifically methylated by PRMT1. Immunofluorescent analyses of endogenous SERBP1 showed predominant cytoplasmic localization of SERBP1. Treatment of AdOx or PRMT1 siRNA increased the nuclear localization of SERBP1. Analyses of different deletions indicated that the middle RG region is important for the nuclear localization while both N- and C- terminus are required for nuclear export. Low methylation of the C-terminal RGG region also favors nuclear localization. In conclusion, the RG-rich and RGG box of SERBP1 is asymmetrically dimethylated by PRMT1 and the modification affects protein interaction and intracellular localization of the protein. These findings provide the basis for dissecting the roles of SERBP1. J. Cell. Biochem. © 2012 Wiley Periodicals, Inc.
    Electronic ISSN: 0091-7419
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Published by Wiley
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  • 15
    Publication Date: 2015-09-19
    Description: There are growing demands for condition-based monitoring of gearboxes, and techniques to improve the reliability, effectiveness and accuracy for fault diagnosis are considered valuable contributions. Feature selection is still an important aspect in machine learning-based diagnosis in order to reach good performance in the diagnosis system. The main aim of this research is to propose a multi-stage feature selection mechanism for selecting the best set of condition parameters on the time, frequency and time-frequency domains, which are extracted from vibration signals for fault diagnosis purposes in gearboxes. The selection is based on genetic algorithms, proposing in each stage a new subset of the best features regarding the classifier performance in a supervised environment. The selected features are augmented at each stage and used as input for a neural network classifier in the next step, while a new subset of feature candidates is treated by the selection process. As a result, the inherent exploration and exploitation of the genetic algorithms for finding the best solutions of the selection problem are locally focused. The Sensors 2015, 15 23904 approach is tested on a dataset from a real test bed with several fault classes under different running conditions of load and velocity. The model performance for diagnosis is over 98%.
    Electronic ISSN: 1424-8220
    Topics: Chemistry and Pharmacology , Electrical Engineering, Measurement and Control Technology
    Published by MDPI Publishing
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  • 16
    Publication Date: 2012-09-08
    Description: Author(s): Katsuyoshi Komatsu, Chuan Li, S. Autier-Laurent, H. Bouchiat, and S. Guéron We investigate the superconducting proximity effect through graphene in the long diffusive junction limit, at low and high magnetic field. The interface quality and sample phase coherence lead to a zero-resistance state at low temperature, zero magnetic field, and high doping. We find a striking sup... [Phys. Rev. B 86, 115412] Published Fri Sep 07, 2012
    Keywords: Surface physics, nanoscale physics, low-dimensional systems
    Print ISSN: 1098-0121
    Electronic ISSN: 1095-3795
    Topics: Physics
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  • 17
    Publication Date: 2012-06-06
    Description: Background: Accurate modeling of electrostatic potential and corresponding energies becomesincreasingly important for understanding properties of biological macromolecules and theircomplexes. However, this is not an easy task due to the irregular shape of biological entitiesand the presence of water and mobile ions. Results: Here we report a comprehensive suite for the well-known Poisson-Boltzmann solver, DelPhi,enriched with additional features to facilitate DelPhi usage. The suite allows for easydownload of both DelPhi executable files and source code along with a makefile for localinstallations. The users can obtain the DelPhi manual and parameter files required for thecorresponding investigation. Non-experienced researchers can download examples containingall necessary data to carry out DelPhi runs on a set of selected examples illustrating variousDelPhi features and demonstrating DelPhi's accuracy against analytical solutions. Conclusions: DelPhi suite offers not only the DelPhi executable and sources files, examples and parameterfiles, but also provides links to third party developed resources either utilizing DelPhi orproviding plugins for DelPhi. In addition, the users and developers are offered a forum toshare ideas, resolve issues, report bugs and seek help with respect to the DelPhi package. Theresource is available free of charge for academic users from URL:http://compbio.clemson.edu/delphi.php
    Electronic ISSN: 2046-1682
    Topics: Biology , Physics
    Published by BioMed Central
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  • 18
    Publication Date: 2011-03-03
    Description: The transversely isotropic magnetoelectroelastic solids plane problem in rectangular domain is derived to Hamiltonian system. In symplectic geometry space with the origin variables—displacements, electric potential, and magnetic potential, as well as their duality variables—lengthways stress, electric displacement, and magnetic induction, on the basis of the obtained eigensolutions of zero-eigenvalue, the eigensolutions of nonzero-eigenvalues are also obtained. The former are the basic solutions of Saint-Venant problem, and the latter are the solutions which have the local effect, decay drastically with respect to distance, and are covered in the Saint-Venant principle. So the complete solution of the problem is given out by the symplectic eigensolutions expansion. Finally, a few examples are selected and their analytical solutions are presented.
    Print ISSN: 1110-757X
    Electronic ISSN: 1687-0042
    Topics: Mathematics
    Published by Hindawi
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  • 19
    Publication Date: 2019
    Description: Hongze Lake is the first natural sink for transferring drinking water along the east route of the South-to-North Water Diversion Project in China. Thus, the assessment of health risk associated with sediment and soil in Hongze Lake is of vital importance in terms of protecting public health. This study surveyed the distribution of sixteen polycyclic aromatic hydrocarbons in different types of bank soils and sediments at the estuary area of Hongze Lake. The total concentrations of PAHs range between 562.4 and 1585.8 ng/g, and 3- and 4-ring PAHs are the majority in all samples, accounting for 78.2% to 92.3% of the total PAHs. Source analysis was conducted, and the results showed that PAHs in the estuary area mainly come from the burning of fossil fuels, leakage of oil products, low temperature combustion, biomass fuel, and transportation. The risk assessment of the study area showed that the K values of all the points were between 0.1~3, indicating that there was a low ecological risk. This study indicates that further policies for controlling pollution sources of PAHs are needed for reducing health risks associated with fresh water in Hongze Lake.
    Electronic ISSN: 2076-3298
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI
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  • 20
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