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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/28203366/sex-differences-in-variability-across-timescales-in-balb-c-mice
#5
Benjamin L Smarr, Azure D Grant, Irving Zucker, Brian J Prendergast, Lance J Kriegsfeld
BACKGROUND: Females are markedly underinvestigated in the biological and behavioral sciences due to the presumption that cyclic hormonal changes across the ovulatory cycle introduce excess variability to measures of interest in comparison to males. However, recent analyses indicate that male and female mice and rats exhibit comparable variability across numerous physiological and behavioral measures, even when the stage of the estrous cycle is not considered. Hormonal changes across the ovulatory cycle likely contribute cyclic, intra-individual variability in females, but the source(s) of male variability has, to our knowledge, not been investigated...
2017: Biology of Sex Differences
https://www.readbyqxmd.com/read/28199928/spectrophotometric-determination-of-meclizine-hydrochloride-and-pyridoxine-hydrochloride-in-laboratory-prepared-mixtures-and-in-their-pharmaceutical-preparation
#6
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
#7
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/28194648/epileptic-seizure-classifications-of-single-channel-scalp-eeg-data-using-wavelet-based-features-and-svm
#8
Suparerk Janjarasjitt
In this study, wavelet-based features of single-channel scalp EEGs recorded from subjects with intractable seizure are examined for epileptic seizure classification. The wavelet-based features extracted from scalp EEGs are simply based on detail and approximation coefficients obtained from the discrete wavelet transform. Support vector machine (SVM), one of the most commonly used classifiers, is applied to classify vectors of wavelet-based features of scalp EEGs into either seizure or non-seizure class. In patient-based epileptic seizure classification, a training data set used to train SVM classifiers is composed of wavelet-based features of scalp EEGs corresponding to the first epileptic seizure event...
February 13, 2017: Medical & Biological Engineering & Computing
https://www.readbyqxmd.com/read/28192170/a-new-approach-to-analyze-data-from-eeg-based-concealed-face-recognition-system
#9
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/28191461/three-class-mammogram-classification-based-on-descriptive-cnn-features
#10
M Mohsin Jadoon, Qianni Zhang, Ihsan Ul Haq, Sharjeel Butt, Adeel Jadoon
In this paper, a novel classification technique for large data set of mammograms using a deep learning method is proposed. The proposed model targets a three-class classification study (normal, malignant, and benign cases). In our model we have presented two methods, namely, convolutional neural network-discrete wavelet (CNN-DW) and convolutional neural network-curvelet transform (CNN-CT). An augmented data set is generated by using mammogram patches. To enhance the contrast of mammogram images, the data set is filtered by contrast limited adaptive histogram equalization (CLAHE)...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28187898/vessel-segmentation-and-microaneurysm-detection-using-discriminative-dictionary-learning-and-sparse-representation
#11
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
#12
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
#13
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
#14
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
#15
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/28174612/classification-of-epileptic-seizures-using-wavelet-packet-log-energy-and-norm-entropies-with-recurrent-elman-neural-network-classifier
#16
S Raghu, N Sriraam, G Pradeep Kumar
Electroencephalogram shortly termed as EEG is considered as the fundamental segment for the assessment of the neural activities in the brain. In cognitive neuroscience domain, EEG-based assessment method is found to be superior due to its non-invasive ability to detect deep brain structure while exhibiting superior spatial resolutions. Especially for studying the neurodynamic behavior of epileptic seizures, EEG recordings reflect the neuronal activity of the brain and thus provide required clinical diagnostic information for the neurologist...
February 2017: Cognitive Neurodynamics
https://www.readbyqxmd.com/read/28173924/chemometric-analysis-of-comprehensive-two-dimensional-gas-chromatography-mass-spectrometry-metabolomics-data
#17
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/28173806/ecg-signal-performance-de-noising-assessment-based-on-threshold-tuning-of-dual-tree-wavelet-transform
#18
Oussama El B'charri, Rachid Latif, Khalifa Elmansouri, Abdenbi Abenaou, Wissam Jenkal
BACKGROUND: Since the electrocardiogram (ECG) signal has a low frequency and a weak amplitude, it is sensitive to miscellaneous mixed noises, which may reduce the diagnostic accuracy and hinder the physician's correct decision on patients. METHODS: The dual tree wavelet transform (DT-WT) is one of the most recent enhanced versions of discrete wavelet transform. However, threshold tuning on this method for noise removal from ECG signal has not been investigated yet...
February 7, 2017: Biomedical Engineering Online
https://www.readbyqxmd.com/read/28169003/increased-calcium-leak-associated-with-reduced-calsequestrin-expression-in-hyperthyroid-cardiomyocytes
#19
David R de Alba-Aguayo, Natalia Pavón, Martha Mercado-Morales, Miyamin Miranda-Saturnino, Mavil López-Casamichana, Agustin Guerrero-Hernández, Angelica Rueda
INTRODUCTION: Calcium (Ca(2+)) leak during cardiac diastole is chiefly mediated by intracellular Ca(2+) channel/Ryanodine Receptors. Increased diastolic Ca(2+) leak has been proposed as the mechanism underlying the appearance of hereditary arrhythmias. However, little is known about alterations in diastolic Ca(2+) leak and the specific roles played by key intracellular Ca(2+)-handling proteins in hyperthyroidism, a known arrhythmogenic condition. AIM: We sought to determine whether there were modifications in diastolic Ca(2+) leak, based on the recording of Ca(2+) sparks and Ca(2+) waves; we also investigated changes in the expression and activity of key Ca(2+) handling proteins, including ryanodine receptors, Sarco-Endoplasmic Reticulum Ca(2+) ATPase pump and calsequestrin in isolated left-ventricular cardiomyocytes isolated from hyperthyroid rats...
January 23, 2017: Cell Calcium
https://www.readbyqxmd.com/read/28166511/a-solitary-feature-based-lung-nodule-detection-approach-for-chest-x-ray-radiographs
#20
Xuechen Li, Linlin Shen, Suhuai Luo
Lung cancer is one of the most deadly diseases. It has a high death rate and its incidence rate has been increasing all over the world. Lung cancer appears as a solitary nodule in chest x-ray radiograph (CXR). Therefore, lung nodule detection in CXR could have a significant impact on early detection of lung cancer. Radiologists define a lung nodule in chest x-ray radiographs as "solitary white nodule-like blob". However, the solitary feature has not been employed for lung nodule detection before. In this paper, a solitary feature-based lung nodule detection method was proposed...
January 31, 2017: IEEE Journal of Biomedical and Health Informatics
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