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https://www.readbyqxmd.com/read/28937641/measurement-of-non-stationary-characteristics-of-a-landfall-typhoon-at-the-jiangyin-bridge-site
#1
Xuhui He, Hongxi Qin, Tianyou Tao, Wenshuo Liu, Hao Wang
The wind-sensitive long-span suspension bridge is a vital element in land transportation. Understanding the wind characteristics at the bridge site is thus of great significance to the wind- resistant analysis of such a flexible structure. In this study, a strong wind event from a landfall typhoon called Soudelor recorded at the Jiangyin Bridge site with the anemometer is taken as the research object. As inherent time-varying trends are frequently captured in typhoon events, the wind characteristics of Soudelor are analyzed in a non-stationary perspective...
September 22, 2017: Sensors
https://www.readbyqxmd.com/read/28935899/decadal-radon-cycles-in-a-hot-spring
#2
Rui Yan, Heiko Woith, Rongjiang Wang, Guangcai Wang
A high-fidelity record covering nearly 40 years of water-dissolved radon from the hot spring site of BangLazhang (BLZ), Southwestern China is presented to study multi-year periodicities of radon. Ancillary observational data, i.e., water temperature, spring discharge rate, barometric pressure, combined with regional rainfall, galactic cosmic rays (GCR flux is modulated by solar wind and thus a proxy for solar activity) and regional seismicity from the same period are considered to identify potentially influencing factors controlling the changes in radon...
September 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28932236/quantitative-evaluation-of-temporal-regularizers-in-compressed-sensing-dynamic-contrast-enhanced-mri-of-the-breast
#3
Dong Wang, Lori R Arlinghaus, Thomas E Yankeelov, Xiaoping Yang, David S Smith
PURPOSE: Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is used in cancer imaging to probe tumor vascular properties. Compressed sensing (CS) theory makes it possible to recover MR images from randomly undersampled k-space data using nonlinear recovery schemes. The purpose of this paper is to quantitatively evaluate common temporal sparsity-promoting regularizers for CS DCE-MRI of the breast. METHODS: We considered five ubiquitous temporal regularizers on 4...
2017: International Journal of Biomedical Imaging
https://www.readbyqxmd.com/read/28930184/use-of-wavelet-transform-to-detect-compensated-and-decompensated-stages-in-the-congestive-heart-failure-patient
#4
Pratibha Sharma, Kimberly Newman, Carlin S Long, A J Gasiewski, Frank Barnes
This research work is aimed at improving health care, reducing cost, and the occurrence of emergency hospitalization in patients with Congestive Heart Failure (CHF) by analyzing heart and lung sounds to distinguish between the compensated and decompensated states. Compensated state defines stable state of the patient but with lack of retention of fluids in lungs, whereas decompensated state leads to unstable state of the patient with lots of fluid retention in the lungs, where the patient needs medication. Acoustic signals from the heart and the lung were analyzed using wavelet transforms to measure changes in the CHF patient's status from the decompensated to compensated and vice versa...
September 20, 2017: Biosensors
https://www.readbyqxmd.com/read/28928711/validation-of-a-step-detection-algorithm-during-straight-walking-and-turning-in-patients-with-parkinson-s-disease-and-older-adults-using-an-inertial-measurement-unit-at-the-lower-back
#5
Minh H Pham, Morad Elshehabi, Linda Haertner, Silvia Del Din, Karin Srulijes, Tanja Heger, Matthis Synofzik, Markus A Hobert, Gert S Faber, Clint Hansen, Dina Salkovic, Joaquim J Ferreira, Daniela Berg, Álvaro Sanchez-Ferro, Jaap H van Dieën, Clemens Becker, Lynn Rochester, Gerhard Schmidt, Walter Maetzler
INTRODUCTION: Inertial measurement units (IMUs) positioned on various body locations allow detailed gait analysis even under unconstrained conditions. From a medical perspective, the assessment of vulnerable populations is of particular relevance, especially in the daily-life environment. Gait analysis algorithms need thorough validation, as many chronic diseases show specific and even unique gait patterns. The aim of this study was therefore to validate an acceleration-based step detection algorithm for patients with Parkinson's disease (PD) and older adults in both a lab-based and home-like environment...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28926953/short-circuit-fault-detection-and-classification-using-empirical-wavelet-transform-and-local-energy-for-electric-transmission-line
#6
Nantian Huang, Jiajin Qi, Fuqing Li, Dongfeng Yang, Guowei Cai, Guilin Huang, Jian Zheng, Zhenxin Li
In order to improve the classification accuracy of recognizing short-circuit faults in electric transmission lines, a novel detection and diagnosis method based on empirical wavelet transform (EWT) and local energy (LE) is proposed. First, EWT is used to deal with the original short-circuit fault signals from photoelectric voltage transformers, before the amplitude modulated-frequency modulated (AM-FM) mode with a compactly supported Fourier spectrum is extracted. Subsequently, the fault occurrence time is detected according to the modulus maxima of intrinsic mode function (IMF₂) from three-phase voltage signals processed by EWT...
September 16, 2017: Sensors
https://www.readbyqxmd.com/read/28923711/identifying-the-arrival-of-extensional-and-flexural-wave-modes-using-wavelet-decomposition-of-ultrasonic-signals
#7
Arnab Gupta, John C Duke
In health monitoring applications of composite materials, the health state of specimens is often evaluated using naturally occurring and simulated Acoustic Emission stress waves. For such applications, identifying the arrival times of the extensional and flexural wave modes from acquired signals is a crucial step, and must be performed reliably and potentially on large sets of signals. This article proposes using the wavelet decomposition of a signal to develop a fast, algorithmic and automated approach to estimate the arrival times of the extensional and flexural wave modes...
September 9, 2017: Ultrasonics
https://www.readbyqxmd.com/read/28923710/spatiotemporal-drought-variability-on-the-mongolian-plateau-from-1980-2014-based-on-the-spei-pm-intensity-analysis-and-hurst-exponent
#8
Siqin Tong, Quan Lai, Jiquan Zhang, Yuhai Bao, A Lusi, Qiyun Ma, Xiangqian Li, Feng Zhang
Knowledge about variations of drought can provide a scientific basis for water resource planning and drought mitigation. In this study, the variations and patterns of drought identified by the Standardized Precipitation Evapotranspiration Index (SPEI) were investigated on the Mongolian Plateau for the period 1980-2014, based on intensity analysis, linear regression, the Mann-Kendall test, wavelet analysis, and Hurst exponent. The results show that: 1) the annual SPEI decreased at a rate of -0.0133/yr over the past 35years, and a major abrupt change occurred in 1999; 2) drought on the Mongolian Plateau intensified from 1980 to 2014, and the drought in Mongolia has been more serious than in Inner Mongolia since the beginning of the 21st century; 3) the rate of drought/wet changes in 1980s-1990s and 1990s-2000s were faster than in 2000s-2010s...
September 16, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28922119/pure-let-image-deconvolution
#9
Jizhou Li, Florian Luisier, Thierry Blu
We propose a non-iterative image deconvolution algorithm for data corrupted by Poisson or mixed Poisson-Gaussian noise. Many applications involve such a problem, ranging from astronomical to biological imaging. We parametrize the deconvolution process as a linear combination of elementary functions, termed as linear expansion of thresholds (LET). This parametrization is then optimized by minimizing a robust estimate of the true mean squared error, the Poisson unbiased risk estimate (PURE). Each elementary function consists of a Wiener filtering followed by a pointwise thresholding of undecimated Haar wavelet coefficients...
September 18, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28916149/wavelet-based-tracking-of-bacteria-in-unreconstructed-off-axis-holograms
#10
Zach Marin, J Kent Wallace, Jay Nadeau, Andre Khalil
We propose an automated wavelet-based method of tracking particles in unreconstructed off-axis holograms to provide rough estimates of the presence of motion and particle trajectories in digital holographic microscopy (DHM) time series. The wavelet transform modulus maxima segmentation method is adapted and tailored to extract Airy-like diffraction disks, which represent bacteria, from DHM time series. In this exploratory analysis, the method shows potential for estimating bacterial tracks in low-particle-density time series, based on a preliminary analysis of both living and dead Serratia marcescens, and for rapidly providing a single-bit answer to whether a sample chamber contains living or dead microbes or is empty...
September 12, 2017: Methods: a Companion to Methods in Enzymology
https://www.readbyqxmd.com/read/28913520/evidential-value-of-polymeric-materials-chemometric-tactics-for-spectral-data-compression-combined-with-likelihood-ratio-approach
#11
A Menżyk, A Martyna, G Zadora
Polymers have become a ubiquitous element of our culture. Therefore, these materials may play an important role in forensic investigations, serving as mute witnesses of occurrences such as car accidents. In this study, the possibilities provided by the likelihood ratio (LR) approach to estimate the evidential value of observed similarities and differences, and to discriminate among NIR spectral data originating from polypropylene automotive parts and household items, were investigated. Since the construction of LR models requires the introduction of only a few variables, the main objective was to reduce the dimensionality of registered spectra, which are characterised by over a thousand variables...
September 15, 2017: Analyst
https://www.readbyqxmd.com/read/28912073/mapping-of-ventricular-arrhythmias-using-a-novel-noninvasive-epicardial-and-endocardial-electrophysiology-system
#12
Alexey Tsyganov, Erik Wissner, Andreas Metzner, Sergey Mironovich, Maria Chaykovskaya, Vitaly Kalinin, Mikhail Chmelevsky, Christine Lemes, Karl-Heinz Kuck
INTRODUCTION: The aim of this study was to assess the use of a novel noninvasive epicardial and endocardial electrophysiology system (NEEES) for mapping of ventricular arrhythmias. METHODS: Eight patients (2 females, mean age 50±17 years) with ischemic (n=3) and nonischemic (n=5) cardiomyopathy and inducible ventricular arrhythmias during electrophysiology study were enrolled. Noninvasive mapping of ventricular arrhythmias was performed using the NEEES based on body-surface electrocardiograms and computed tomography imaging data...
August 1, 2017: Journal of Electrocardiology
https://www.readbyqxmd.com/read/28900815/wavelet-based-encoding-scheme-for-controlling-size-of-compressed-ecg-segments-in-telecardiology-systems
#13
Asiya M Al-Busaidi, Lazhar Khriji, Farid Touati, Mohd Fadlee Rasid, Adel Ben Mnaouer
One of the major issues in time-critical medical applications using wireless technology is the size of the payload packet, which is generally designed to be very small to improve the transmission process. Using small packets to transmit continuous ECG data is still costly. Thus, data compression is commonly used to reduce the huge amount of ECG data transmitted through telecardiology devices. In this paper, a new ECG compression scheme is introduced to ensure that the compressed ECG segments fit into the available limited payload packets, while maintaining a fixed CR to preserve the diagnostic information...
September 12, 2017: Journal of Medical Systems
https://www.readbyqxmd.com/read/28900626/emotion-recognition-from-eeg-signals-using-multidimensional-information-in-emd-domain
#14
Ning Zhuang, Ying Zeng, Li Tong, Chi Zhang, Hanming Zhang, Bin Yan
This paper introduces a method for feature extraction and emotion recognition based on empirical mode decomposition (EMD). By using EMD, EEG signals are decomposed into Intrinsic Mode Functions (IMFs) automatically. Multidimensional information of IMF is utilized as features, the first difference of time series, the first difference of phase, and the normalized energy. The performance of the proposed method is verified on a publicly available emotional database. The results show that the three features are effective for emotion recognition...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28900414/alterations-in-spectral-attributes-of-surface-electromyograms-after-utilization-of-a-foot-drop-stimulator-during-post-stroke-gait
#15
Rakesh Pilkar, Arvind Ramanujam, Karen J Nolan
BACKGROUND: A foot drop stimulator (FDS) is a rehabilitation intervention that stimulates the common peroneal nerve to facilitate ankle dorsiflexion at the appropriate time during post-stroke hemiplegic gait. Time-frequency analysis (TFA) of non-stationary surface electromyograms (EMG) and spectral variables such as instantaneous mean frequency (IMNF) can provide valuable information on the long-term effects of FDS intervention in terms of changes in the motor unit (MU) recruitment during gait, secondary to improved dorsiflexion...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28895021/k-band-doppler-radar-for-contact-less-overnight-sleep-marker-assessment-a-pilot-validation-study
#16
Rakesh Vasireddy, Corinne Roth, Johannes Mathis, Josef Goette, Marcel Jacomet, Andreas Vogt
An estimated 45 million persons in Europe are annually subjected to sleep-wake disorders. State-of-the-art polysomnography provides sophisticated insights into sleep (patho)physiology. A drawback of the method, however, is the obtrusive setting dependent on a clinical-based sleep laboratory with high operational costs. A contact-less prototype was developed to monitor limb movements and vital signs during sleep. A dual channel K-band Doppler radar transceiver captured limb movements and periodic chest wall motion due to respiration and heart activity...
September 11, 2017: Journal of Clinical Monitoring and Computing
https://www.readbyqxmd.com/read/28894589/automated-detection-of-heart-ailments-from-12-lead-ecg-using-complex-wavelet-sub-band-bi-spectrum-features
#17
Rajesh Kumar Tripathy, Samarendra Dandapat
The complex wavelet sub-band bi-spectrum (CWSB) features are proposed for detection and classification of myocardial infarction (MI), heart muscle disease (HMD) and bundle branch block (BBB) from 12-lead ECG. The dual tree CW transform of 12-lead ECG produces CW coefficients at different sub-bands. The higher-order CW analysis is used for evaluation of CWSB. The mean of the absolute value of CWSB, and the number of negative phase angle and the number of positive phase angle features from the phase of CWSB of 12-lead ECG are evaluated...
April 2017: Healthcare Technology Letters
https://www.readbyqxmd.com/read/28894460/an-automatic-gastrointestinal-polyp-detection-system-in-video-endoscopy-using-fusion-of-color-wavelet-and-convolutional-neural-network-features
#18
Mustain Billah, Sajjad Waheed, Mohammad Motiur Rahman
Gastrointestinal polyps are considered to be the precursors of cancer development in most of the cases. Therefore, early detection and removal of polyps can reduce the possibility of cancer. Video endoscopy is the most used diagnostic modality for gastrointestinal polyps. But, because it is an operator dependent procedure, several human factors can lead to misdetection of polyps. Computer aided polyp detection can reduce polyp miss detection rate and assists doctors in finding the most important regions to pay attention to...
2017: International Journal of Biomedical Imaging
https://www.readbyqxmd.com/read/28891524/semantic-category-based-decoding-of-human-brain-activity-using-a-gabor-based-model-by-estimating-intracranial-field-potential-range-in-temporal-cortex
#19
Fateme Zareayan Jahromy, Mohammed Reza Daliri
Predicting and decoding the recorded neural activity for visual stimuli is the topic of many studies. This prediction can be made by comparing the model's responses to different stimuli with the available recorded brain signal. The neural activities can be decoded then by finding the stimulus which has generated the nearest model's response to the recorded signal. In this study, a model is proposed which can estimate the response of human brain to images from different conceptual categories by inserting the visual stimuli as the model input after filtering by Gabor wavelets...
2017: Journal of Integrative Neuroscience
https://www.readbyqxmd.com/read/28889077/a-method-for-quantifying-recurrent-patterns-of-local-wavefront-direction-during-atrial-fibrillation
#20
James P Hummel, Alex Baher, Ben Buck, Manuel Fanarjian, Charles L Webber, Joseph G Akar
INTRODUCTION: Spiral wave reentry is a potential mechanism of atrial fibrillation (AF), but is difficult to differentiate clinically from multiple wavelet breakup using standard bipolar recordings. We developed a new methodology using bipolar recordings to estimate the direction of local activation wavefronts during AF by calculating the electrogram conformation (Egm-C). We subsequently used recurrence quantification analysis (RQA) of Egm-C to differentiate regions of spiral wave reentry from wavelet breakup...
September 1, 2017: Computers in Biology and Medicine
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