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https://www.readbyqxmd.com/read/28208820/optimal-resonant-band-demodulation-based-on-an-improved-correlated-kurtosis-and-its-application-in-bearing-fault-diagnosis
#1
Xianglong Chen, Bingzhi Zhang, Fuzhou Feng, Pengcheng Jiang
The kurtosis-based indexes are usually used to identify the optimal resonant frequency band. However, kurtosis can only describe the strength of transient impulses, which cannot differentiate impulse noises and repetitive transient impulses cyclically generated in bearing vibration signals. As a result, it may lead to inaccurate results in identifying resonant frequency bands, in demodulating fault features and hence in fault diagnosis. In view of those drawbacks, this manuscript redefines the correlated kurtosis based on kurtosis and auto-correlative function, puts forward an improved correlated kurtosis based on squared envelope spectrum of bearing vibration signals...
February 13, 2017: Sensors
https://www.readbyqxmd.com/read/28208732/online-condition-monitoring-of-a-rail-fastening-system-on-high-speed-railways-based-on-wavelet-packet-analysis
#2
Jiahong Wei, Chong Liu, Tongqun Ren, Haixia Liu, Wenjing Zhou
The rail fastening system is an important part of a high-speed railway track. It is always critical to the operational safety and comfort of railway vehicles. Therefore, the condition detection of the rail fastening system, looseness or absence, is an important task in railway maintenance. However, the vision-based method cannot identify the severity of rail fastener looseness. In this paper, the condition of rail fastening system is monitored based on an automatic and remote-sensing measurement system. Meanwhile, wavelet packet analysis is used to analyze the acceleration signals, based on which two damage indices are developed to locate the damage position and evaluate the severity of rail fasteners looseness, respectively...
February 8, 2017: Sensors
https://www.readbyqxmd.com/read/28207900/classification-and-identification-of-rhodobryum-roseum-limpr-and-its-adulterants-based-on-fourier-transform-infrared-spectroscopy-ftir-and-chemometrics
#3
Zhen Cao, Zhenjie Wang, Zhonglin Shang, Jiancheng Zhao
Fourier-transform infrared spectroscopy (FTIR) with the attenuated total reflectance technique was used to identify Rhodobryum roseum from its four adulterants. The FTIR spectra of six samples in the range from 4000 cm-1 to 600 cm-1 were obtained. The second-derivative transformation test was used to identify the small and nearby absorption peaks. A cluster analysis was performed to classify the spectra in a dendrogram based on the spectral similarity. Principal component analysis (PCA) was used to classify the species of six moss samples...
2017: PloS One
https://www.readbyqxmd.com/read/28207404/a-noise-reduction-technique-based-on-nonlinear-kernel-function-for-heart-sound-analysis
#4
Ashok Mondal, Ishan Saxena, Hong Tang, Poulami Banerjee
The main difficulty encountered in interpretation of cardiac sound is interference of noise. The contaminated noise obscures the relevant information which are useful for recognition of heart diseases. The unwanted signals are produced mainly by lungs and surrounding environment. In this paper, a novel heart sound de-noising technique has been introduced based on a combined framework of wavelet packet transform (WPT) and singular value decomposition (SVD). The most informative node of wavelet tree is selected on the criteria of mutual information measurement...
February 13, 2017: IEEE Journal of Biomedical and Health Informatics
https://www.readbyqxmd.com/read/28199928/spectrophotometric-determination-of-meclizine-hydrochloride-and-pyridoxine-hydrochloride-in-laboratory-prepared-mixtures-and-in-their-pharmaceutical-preparation
#5
Maha M Ibrahim, Eman S Elzanfaly, Mohamed B El-Zeiny, Nesreen K Ramadan, Khadiga M Kelani
In this paper, three rapid, simple, accurate and precise spectrophotometric methods were developed for the determination of meclizine hydrochloride in the presence of pyridoxine hydrochloride without previous separation. The methods under study are dual wavelength (DWL), ratio difference (RD) and continuous wavelet transform (CWT). On the other hand, pyridoxine hydrochloride (PYH) was determined directly at 291nm. The methods obey Beer's law in the range of (5-50μg/mL) for both compounds. All the methods were validated according to the ICH guidelines where the accuracy was found to be 98...
February 8, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28198354/noise-robust-unsupervised-spike-sorting-based-on-discriminative-subspace-learning-with-outlier-handling
#6
Mohammad Reza Keshtkaran, Zhi Yang
OBJECTIVE: Spike sorting is a fundamental preprocessing step for many neuroscience studies which rely on the analysis of spike trains. Most of the feature extraction and dimensionality reduction techniques that have been used for spike sorting give a projection subspace which is not necessarily the most discriminative one. Therefore, the clusters which appear inherently separable in some discriminative subspace may overlap if projected using conventional feature extraction approaches leading to a poor sorting accuracy especially when the noise level is high...
February 15, 2017: Journal of Neural Engineering
https://www.readbyqxmd.com/read/28192170/a-new-approach-to-analyze-data-from-eeg-based-concealed-face-recognition-system
#7
A H Mehrnam, A M Nasrabadi, M Ghodoosi, A Mohammadian, Sh Torabi
The purpose of this study is to extend a feature set with non-linear features to improve classification rate of guilty and innocent subjects. Non-linear features can provide extra information about phase space. The Event-Related Potential (ERP) signals were recorded from 49 subjects who participated in concealed face recognition test. For feature extraction, at first, several morphological characteristics, frequency bands, and wavelet coefficients (we call them basic-features) are extracted from each single-trial ERP...
February 9, 2017: International Journal of Psychophysiology
https://www.readbyqxmd.com/read/28187898/vessel-segmentation-and-microaneurysm-detection-using-discriminative-dictionary-learning-and-sparse-representation
#8
Malihe Javidi, Hamid-Reza Pourreza, Ahad Harati
Diabetic retinopathy (DR) is a major cause of visual impairment, and the analysis of retinal image can assist patients to take action earlier when it is more likely to be effective. The accurate segmentation of blood vessels in the retinal image can diagnose DR directly. In this paper, a novel scheme for blood vessel segmentation based on discriminative dictionary learning (DDL) and sparse representation has been proposed. The proposed system yields a strong representation which contains the semantic concept of the image...
February 2017: Computer Methods and Programs in Biomedicine
https://www.readbyqxmd.com/read/28186890/3-d-solid-texture-classification-using-locally-oriented-wavelet-transforms
#9
Yashin Dicente Cid, Henning Muller, Alexandra Platon, Pierre Poletti, Adrien Depeursinge
Many image acquisition techniques used in biomedical imaging, material analysis, and structural geology are capable of acquiring 3-D solid images. Computational analysis of these images is complex but necessary since it is difficult for humans to visualize and quantify their detailed 3-D content. One of the most common methods to analyze 3-D data is to characterize the volumetric texture patterns. Texture analysis generally consists of encoding the local organization of image scales and directions, which can be extremely diverse in 3-D...
February 6, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28186494/oscillatory-pattern-of-acral-skin-blood-flow-within-thermoneutral-zone-in-healthy-humans
#10
Maja Elstad, Ilias Zilakos, Tone Bergersen
OBJECTIVE: The acral skin contains arteriovenous anastomoses, which probably is the main part of skin microcirculation for blood flow adjustments and thermoregulation in the thermoneutral zone. The objective was to investigate if an increase in sympathetic activation during cooling influences the oscillatory pattern of acral skin blood flow. APPROACH: We had measurements of bilateral acral skin blood flow (n=12) during lowering of ambient temperature from 32°C to 18°C...
February 10, 2017: Physiological Measurement
https://www.readbyqxmd.com/read/28178220/a-signal-processing-approach-with-a-smooth-empirical-mode-decomposition-to-reveal-hidden-trace-of-corrosion-in-highly-contaminated-guided-wave-signals-for-concrete-covered-pipes
#11
Javad Rostami, Jingming Chen, Peter W Tse
Ultrasonic guided waves have been extensively applied for non-destructive testing of plate-like structures particularly pipes in past two decades. In this regard, if a structure has a simple geometry, obtained guided waves' signals are easy to explain. However, any small degree of complexity in the geometry such as contacting with other materials may cause an extra amount of complication in the interpretation of guided wave signals. The problem deepens if defects have irregular shapes such as natural corrosion...
February 7, 2017: Sensors
https://www.readbyqxmd.com/read/28177924/adapted-wavelet-transform-improves-time-frequency-representations-a-study-of-auditory-elicited-p300-like-event-related-potentials-in-rats
#12
Nelly Richard, Bettina Laursen, Morten Grupe, Asbjørn M Drewes, Carina Graversen, Helge B D Sørensen, Jesper F Bastlund
OBJECTIVE: Active auditory oddball paradigms are simple tone discrimination tasks used to study the P300 deflection of event-related potentials (ERPs). These ERPs may be quantified by time-frequency analysis. As auditory stimuli cause early high frequency and late low frequency ERP oscillations, the continuous wavelet transform (CWT) is often chosen for decomposition due to its multi-resolution properties. However, as the conventional CWT traditionally applies only one mother wavelet to represent the entire spectrum, the time-frequency resolution is not optimal across all scales...
February 8, 2017: Journal of Neural Engineering
https://www.readbyqxmd.com/read/28173924/chemometric-analysis-of-comprehensive-two-dimensional-gas-chromatography-mass-spectrometry-metabolomics-data
#13
Yahya Izadmanesh, Elba Garreta-Lara, Jahan B Ghasemi, Silvia Lacorte, Victor Matamoros, Roma Tauler
Comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS) is a powerful tool for separation and identification of analytes in complex natural samples. In this paper, different chemometric methods were compared for fast non-targeted GC×GC-TOFMS metabolomic profiling of the crustaceous species Daphnia magna and a general chemometric strategy and workflow is proposed. The strategy proposed in this work combined the compression of GC×GC-TOFMS data matrices in the retention time direction using wavelets and the appropriate column-wise data matrix augmentation arrangement, and its modeling by Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS)...
January 23, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28155648/fast-processing-of-microscopic-images-using-object-based-extended-depth-of-field
#14
Apichart Intarapanich, Saowaluck Kaewkamnerd, Montri Pannarut, Philip J Shaw, Sissades Tongsima
BACKGROUND: Microscopic analysis requires that foreground objects of interest, e.g. cells, are in focus. In a typical microscopic specimen, the foreground objects may lie on different depths of field necessitating capture of multiple images taken at different focal planes. The extended depth of field (EDoF) technique is a computational method for merging images from different depths of field into a composite image with all foreground objects in focus. Composite images generated by EDoF can be applied in automated image processing and pattern recognition systems...
December 22, 2016: BMC Bioinformatics
https://www.readbyqxmd.com/read/28153390/nucleolin-staining-may-aid-in-the-identification-of-circulating-prostate-cancer-cells
#15
Heather J Chalfin, James E Verdone, Emma E van der Toom, Stephanie Glavaris, Michael A Gorin, Kenneth J Pienta
INTRODUCTION: Circulating tumor cells (CTCs) have great potential as circulating biomarkers for solid malignancies. Currently available assays for CTC detection rely on epithelial markers with somewhat limited sensitivity and specificity. We found that the staining pattern of nucleolin, a common nucleolar protein in proliferative cells, separates CTCs from white blood cells (WBCs) in men with metastatic prostate cancer. PATIENTS AND METHODS: Whole peripheral blood from 3 men with metastatic prostate cancer was processed with the AccuCyte CTC system (RareCyte, Seattle, WA)...
January 4, 2017: Clinical Genitourinary Cancer
https://www.readbyqxmd.com/read/28152063/a-wavelet-based-technique-to-predict-treatment-outcome-for-major-depressive-disorder
#16
Wajid Mumtaz, Likun Xia, Mohd Azhar Mohd Yasin, Syed Saad Azhar Ali, Aamir Saeed Malik
Treatment management for Major Depressive Disorder (MDD) has been challenging. However, electroencephalogram (EEG)-based predictions of antidepressant's treatment outcome may help during antidepressant's selection and ultimately improve the quality of life for MDD patients. In this study, a machine learning (ML) method involving pretreatment EEG data was proposed to perform such predictions for Selective Serotonin Reuptake Inhibitor (SSRIs). For this purpose, the acquisition of experimental data involved 34 MDD patients and 30 healthy controls...
2017: PloS One
https://www.readbyqxmd.com/read/28149991/exciton-vibrational-resonance-and-dynamics-of-charge-separation-in-the-photosystem-ii-reaction-center
#17
Vladimir I Novoderezhkin, Elisabet Romero, Javier Prior, Rienk van Grondelle
The dynamics of charge separation in the photosystem II reaction center (PSII-RC) in the presence of intramolecular vibrations with their frequency matching the energy gap between the exciton state acting as the primary electron donor and the first charge-transfer (CT) state are investigated. A reduced PSII-RC 4-state model explicitly including a CT state is analyzed within Redfield relaxation theory in the multidimensional exciton-vibrational (vibronic) basis. This model is used to study coherent energy/electron transfers and their spectral signatures obtained by two-dimensional electronic spectroscopy (2DES)...
February 2, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28144975/seasonality-and-predictability-shape-temporal-species-diversity
#18
Jonathan D Tonkin, Michael T Bogan, Núria Bonada, Blanca Rios-Touma, David A Lytle
Temporal environmental fluctuations, such as seasonality, exert strong controls on biodiversity. While the effects of seasonality are well known, the predictability of fluctuations across years may influence seasonality in ways that are less well understood. The ability of a habitat to support unique, non-nested assemblages of species at different times of the year should depend on both seasonality (occurrence of events at specific periods of the year) and predictability (the reliability of event recurrence) of characteristic ecological conditions...
January 31, 2017: Ecology
https://www.readbyqxmd.com/read/28139688/comparative-analysis-of-image-classification-methods-for-automatic-diagnosis-of-ophthalmic-images
#19
Liming Wang, Kai Zhang, Xiyang Liu, Erping Long, Jiewei Jiang, Yingying An, Jia Zhang, Zhenzhen Liu, Zhuoling Lin, Xiaoyan Li, Jingjing Chen, Qianzhong Cao, Jing Li, Xiaohang Wu, Dongni Wang, Wangting Li, Haotian Lin
There are many image classification methods, but it remains unclear which methods are most helpful for analyzing and intelligently identifying ophthalmic images. We select representative slit-lamp images which show the complexity of ocular images as research material to compare image classification algorithms for diagnosing ophthalmic diseases. To facilitate this study, some feature extraction algorithms and classifiers are combined to automatic diagnose pediatric cataract with same dataset and then their performance are compared using multiple criteria...
January 31, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28129152/a-new-sparse-representation-framework-for-reconstruction-of-an-isotropic-high-spatial-resolution-mr-volume-from-orthogonal-anisotropic-resolution-scans
#20
Yuanyuan Jia, Ali Gholipour, Zhongshi He, Simon Warfield
In magnetic resonance (MR), hardware limitations, scan time constraints, and patient movement often result in the acquisition of anisotropic 3D MR images with limited spatial resolution in the out-of-plane views. Our goal is to construct an isotropic high-resolution 3D MR image through upsampling and fusion of orthogonal anisotropic input scans. We propose a multi-frame super-resolution (SR) reconstruction technique based on sparse representation of MR images. Our proposed algorithm exploits the correspondence between the high-resolution slices and the low-resolution sections of the orthogonal input scans as well as the self-similarity of each input scan to train pairs of over-complete dictionaries that are used in a sparse land local model to upsample the input scans...
January 23, 2017: IEEE Transactions on Medical Imaging
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