Comparison Of Waveforms Research Articles

TOMOGRAPHY S VELOCITY STRUCTURE BETWEEN WASHINGTON’S EARTHQUAKE C022801L AND OBSERVATIONAL STATION TUC THROUGH SEISMOGRAM ANALYSIS

In this research the S speed structure is investigated by seismogram analysis of Washington's earthquake, C022801L using data of TUC station, Tucson, Arizona, U.S.A. The seismogram comparison between the observed and the synthetic seismogram is conducted in time domain and three components simultaneously. The initially input for the calculation of synthetic seismogram is earth model of PREMAN and CMT solution from the earthquake. A low-pass Butterworth filter with corner frequency of 20 mHz is convolved to observed and synthetic seismogram. Waveform comparison shows a real deviation when travel time and waveform of some wave phase are compared, namely on S wave, surface wave of Love and Rayleigh and wave ScS and ScS-2. This research shows, how sensitive the waveform is to the earth model, better than the method of travel time or the dispersion analysis. Research hereinafter is addressed to finish the found discrepancies at S wave, surface wave of Love and Rayleigh and ScS and ScS-2 wave, in observation station TUC. To obtain the seismogram fitting, correction for S speed structure in earth model is needed, that are changes of earth crust thickness, the speed model ofb in upper mantle covering the speed gradient ofb h and value of zeroeth order coefficient for theb h andb v, for accomplishing the discrepancies at surface wave of Love and Rayleigh. Further correction on S speed is conducted to accomplish the deviation at S wave at earth layering systems from Upper Mantle up to a 630 km depth. Mean while for the ScS and ScS-2 wave phase the correction is carried out on S speed in the earth layers up to CMB. Fitting Seismogram is obtained at waveform of various wave phases that is S wave, surface wave of Love and Rayleigh and ScS, ScS-2 wave, either on travel time or especially also at oscillation number in Love wave. This result indicates that the anisotropy is occurred not only in upper mantle but till deeper earth layers, till CMB.

S WAVE VELOCITY STRUCTURE IN NONTECTONIC SE ASIA BY SEISMOGRAM ANALYSIS OF THE EARTHQUAKES IN SUMATRA–JAVA AT TATO STATION, TAIWAN

The S wave velocity structure beneath South-East Asia and South China Sea due to earthquakes in Sumatra–Java subduction zone has been investigated through seismogram analysis in time domain and three components simultaneously, using data recorded in TATO, Taiwan seismological station. The synthetic seismogram was calculated using the GEMINI method, which consists of the earth model and the CMT solution of the earthquake. A low-pass filter with corner frequency of 20 mHz is imposed to the seismograms. Response file inversion subjected on the measured seismogram will compare the measured and the synthetic seismogram in the same unit. The seismogram comparison indicated that the synthetic seismogram constructed from PREMAN earth model deviates greatly from the measured one. The deviation occurred on the arrival time of surface wave of Rayleigh and Love as well as S body waves.The S, Love, and Rayleigh waveform deviations on arrival time or oscillation number are solved by changing the gradient of βhinto positive in the upper mantle layers, and corrections for zero-order coefficients of β speed polynomial in every earth mantle layers.The interpretation results of seismogram analysis using waveform comparison indicate that the nontectonic South-East Asia area in front of subduction zone has strong negative correction of βvin the upper mantle and with smaller factor also at earth layers below. This result shows stronger vertical anisotropy than that indicated by the PREMAN earth model.

Feasibility of Dual Doppler Velocity Measurements to Estimate Volume Pulsations of an Arterial Segment

If volume flow was measured at each end of an arterial segment with no branches, any instantaneous differences would indicate that volume was increasing or decreasing transiently within the segment. This concept could provide an alternative method to assess the mechanical properties or distensibility of an artery noninvasively using ultrasound. The goal of this study was to determine the feasibility of using Doppler measurements of pulsatile velocity (opposed to flow) at two sites to estimate the volume pulsations of the intervening arterial segment. To test the concept over a wide range of dimensions, we made simultaneous measurements of velocity in a short 5 mm segment of a mouse common carotid artery and in a longer 20 cm segment of a human brachial-radial artery using a two-channel 20 MHz pulsed Doppler and calculated the waveforms and magnitudes of the volume pulsations during the cardiac cycle. We also estimated pulse wave velocity from the velocity upstroke arrival times and measured artery wall motion using tissue Doppler methods for comparison of magnitudes and waveforms. Volume pulsations estimated from Doppler velocity measurements were 16% for the mouse carotid artery and 4% for the human brachial artery. These values are consistent with the measured pulse wave velocities of 4.2 m/s and 10 m/s, respectively, and with the mouse carotid diameter pulsation. In addition, the segmental volume waveforms resemble diameter and pressure waveforms as expected. We conclude that with proper application and further validation, dual Doppler velocity measurements can be used to estimate the magnitude and waveform of volume pulsations of an arterial segment and to provide an alternative noninvasive index of arterial mechanical properties. (E-mail: cjhartley@ieee.org)

An expanded set of photoreceptors in the Eastern Pale Clouded Yellow butterfly, Colias erate

We studied the spectral and polarisation sensitivities of photoreceptors of the butterfly Colias erate by using intracellular electrophysiological recordings and stimulation with light pulses. We developed a method of response waveform comparison (RWC) for evaluating the effective intensity of the light pulses. We identified one UV, four violet-blue, two green and two red photoreceptor classes. We estimated the peak wavelengths of four rhodopsins to be at about 360, 420, 460 and 560 nm. The four violet-blue classes are presumably based on combinations of two rhodopsins and a violet-absorbing screening pigment. The green classes have reduced sensitivity in the ultraviolet range. The two red classes have primary peaks at about 650 and 665 nm, respectively, and secondary peaks at about 480 nm. The shift of the main peak, so far the largest amongst insects, is presumably achieved by tuning the effective thickness of the red perirhabdomal screening pigment. Polarisation sensitivity of green and red photoreceptors is higher at the secondary than at the main peak. We found a 20-fold variation of sensitivity within the cells of one green class, implying possible photoreceptor subfunctionalisation. We propose an allocation scheme of the receptor classes into the three ventral ommatidial types.

Comparison of Canine Stifle Kinematic Data Collected with Three Different Targeting Models

To model the kinematics of the canine stifle in 3 dimensions using the Joint Coordinate System (JCS) and compare the JCS method with linear and segmental models. In vivo biomechanical study. Normal adult mixed breed dogs (n=6). Dogs had 10 retroreflective markers affixed to the skin on the right pelvic limb. Dogs were walked and trotted 5 times through the calibrated space and the procedure was repeated 5 days later. Sagittal flexion and extension angle waveforms acquired during each trial with all 3 models (JCS, Linear, and Segmental) were produced simultaneously during each gait. The JCS method provided additional internal/external and abduction/adduction angles. Comparison of sagittal flexion and extension angle waveforms was performed with generalized indicator function analysis (GIFA) and Fourier analysis. A normalization procedure was performed. Each model provided consistent equivalent sagittal flexion-extension data. The JCS provided consistent additional internal/external and abduction/adduction. Sagittal waveform differences were found between methods and testing days for each dog at a walk and a trot with both GIFA and Fourier analysis. After normalization, differences were less with Fourier analysis and were unaltered with GIFA. Whereas all methods produced similar flexion-extension waveforms, JCS provided additional valuable data. The JCS model provided sagittal plane flexion/extension data as well as internal/external rotation and abduction/adduction data.

A pedagogical Web service-based interactive learning environment for a digital filter design course: An evolutionary approach

The course of digital filter design in electronic/electrical engineering involves complicated mathematical equations and dynamic waveform variations. It is a consensus among educators that using simulation tools assist in improving students' learning experiences. Previous studies on system simulation seemed to lack an appropriate approach to design such a course. Few emphasized the design of an interactive learning environment by using an evolutionary approach. This study integrated the design concept of an evolutionary approach and Web service-based technology into a simulation system entitled Pedagogical Web Service-Based Interactive Learning Environment (PEWSILE) was introduced. The PEWSILE system contained two interactive learning environments—a simple system and an advanced system. It offered a total of six pedagogical Web services. The simple interactive learning environment included text/color-based services, and text/color/diagram-based services. The advanced interactive learning environment included batch-based, interval change-based, comparison-based, and scroll bar-based services. The study also assessed the students' performance in six pedagogical Web services covering interaction and overall use, usefulness, and intention to use through a questionnaire survey and subsequent interviews. Three significant findings were reported. For example, in the advanced interactive learning environment, the designs of interval change-based and comparison-based services make it easier to observe differences in the outcome of parameter change, while batch-based services lacks the element of waveform comparison. In sum, the findings in this study provide helpful implications in designing engineering educational software. © 2010 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 423–433, 2010; View this article online at wileyonlinelibrary.com; DOI 10.1002/cae.20163

Discharge analysis and electrical modeling for the development of efficient dielectric barrier discharge

Dielectric-barrier discharges (DBDs) are characterized by the presence of at least one insulating layer in contact with the discharge between two planar or cylindrical electrodes connected to an AC/pulse power supply. The dielectric layers covering the electrodes act as current limiters and prevent the transition to an arc discharge. DBDs exist usually in filamentary mode, based on the streamer nature of the discharges. The main advantage of this type of electrical discharges is that nonequilibrium and non-thermal plasma conditions can be established at atmospheric pressure. VUV/UV sources based on DBDs are considered as promising alternatives of conventional mercury-based discharge plasmas, producing highly efficient VUV/UV radiation. The experiments have been performed using two coaxial quartz double barrier DBD tubes, which are filled with Xe/Ar at different pressures. A sinusoidal voltage up to 2.4 kV peak with frequencies from 20 to 100 kHz has been applied to the discharge electrodes for the generation of microdischarges. A stable and uniform discharge is produced in the gas gap between the dielectric barrier electrodes. By comparisons of visual images and electrical waveforms, the filamentary discharges for Ar tube while homogeneous discharge for Xe tube at the same conditions have been confirmed. The electrical modeling has been carried out to understand DBD phenomenon in variation of applied voltage waveforms. The simulated discharge characteristics have been validated by the experimental results.

Basic Characteristics of Double Stator Slot-type Permanent Magnet Generator

This paper discusses the basic characteristics of a double stator slot-type permanent magnet generator (DS-PMG). The PMG was basically operated in a single-phase and the flux direction in the air gap was radial. It was developed to optimize the magnetic flux linkage in a single-pole PMG. Simulation with the Finite Element Method (FEM) and calculations were used to analyze the PMG’s characteristics. In addition, the performance of the PMG prototype was evaluated to ensure the simulation results were accurate. The DS-PMG had a low Total Harmonic Distortion (THD) of 6% and high efficiency of 80% at the rated speed of 3000 rpm. Here, THD is a comparison of the fundamental waveform to its harmonic content. Its output power was three times that of the single PMG.

Analysis of two microearthquake swarms in Southeastern Sicily: evidence for active faults?

Two microearthquake swarms occurring in Southeastern Sicily during November 1999 and January 2000 were analysed with respect to their seismotectonic features. Given the low magnitude of the events fault plane solutions for only four major events were computed, which revealed normal fault and inverse fault mechanisms. From the comparison of waveforms and the relation of P- and S-wave peak amplitudes, two families of multiplets were identified, each representing a distinct type of seismic dislocation. Composite fault plane solutions for the two families showed the same trends as for the single major events. The small number of mismatches of the composite solutions supports the hypothesis of two distinct types of seismic dislocation during the whole sequence, i.e. a normal fault mechanism along E-W striking planes and an inverse fault mechanism along NE-SW striking planes.

Effects of Dextromethorphan/Quinidine on Auditory Event-Related Potentials in Multiple Sclerosis Patients With Pseudobulbar Affect

The purpose of this study was to characterize the brain activity and associated cortical structures involved in pseudobulbar affect (PBA), a condition characterized by uncontrollable episodes of laughing and/or crying in patients with multiple sclerosis before and after treatment with dextromethorphan/quinidine (DM/Q). Behavioral responses and event-related potentials (ERPs) in response to subjectively significant and neutral verbal stimuli were recorded from 2 groups: 6 multiple sclerosis patients with PBA before (PBA-preTx) and after (PBA-DM/Q) treatment with DM/Q and 6 healthy control (HC) subjects. Statistical nonparametric mapping comparisons of ERP source current density distributions between groups were conducted for subjectively significant and neutral stimuli separately before and after treatment with DM/Q. Treatment with DM/Q had a normalizing effect on the behavioral responses of PBA patients. Event-related potential waveform comparisons of PBA-preTx and PBA-DM/Q with HC, for both neutral and subjectively significant stimuli, revealed effects on early ERP components. Comparisons between PBA-preTx and HC, in response to subjectively significant stimuli, revealed both early and late effects. Source analysis comparisons between PBA-preTx and PBA-DM/Q indicated distinct activations in areas involved in emotional processing and high-level and associative visual processing in response to neutral stimuli and in areas involved in emotional, somatosensory, primary, and premotor processing in response to subjectively significant stimuli. In most cases, stimuli evoked higher current density in PBA-DM/Q compared with the other groups. In conclusion, differences in brain activity were observed before and after medication. Also, DM/Q administration resulted in normalization of behavioral and electrophysiological measures.

Simultaneous effects of slip and heat transfer on the peristaltic flow

Abstract Slip and heat transfer effects on the peristaltic flow in an asymmetric channel have been examined in this paper. The closed form solutions of momentum and energy equations are obtained for long wavelength and low Reynolds number approximations. Pumping and trapping phenomena are discussed by numerical integration. The variations of velocity and thermal slip parameters are particularly observed. Comparison of different wave forms for symmetric case is presented.

Using TDR Cables and GPS for Landslide Monitoring in High Mountain Area

Time domain reflectometry (TDR) is performed as a complement to the monitoring methods in subsurface deformation in slope together with the global positioning system (GPS) to monitor ground deformation of high-altitude landslides in Li-shan. Four TDR cables were installed in drill holes near the monitoring stations in the landslide area. According to the recorded TDR waveforms, there were shear and tensile zones under the B-5, B-9, C-1, and C-2 stations. A comparison of the TDR waveforms with the monitored data and boring log revealed that the subsurface sliding occurred between layers of colluvium and strongly weathered slate. Three GPS receivers were installed to measure ground displacement in the landslide area. The results from the GPS were compared with the surface extensometers data on-site. The two initial baseline lengths were 451,188.10 and 908,212.4 mm, respectively. The optimal data reduction achieved used a 3 h session with moving average for each hour's GPS data. The standard deviation values of the GPS were 2.16 and 2.44 mm, respectively, on-site. The results of TDR and GPS measurements showed their applicability in the deformation monitoring of high-mountain landslides.

Comparison of numerical and post-Newtonian waveforms for generic precessing black-hole binaries

We compare waveforms and orbital dynamics from the first long-term, fully nonlinear, numerical simulations of a generic black-hole binary configuration with post-Newtonian (PN) predictions. The binary has mass ratio q{approx}0.8 with arbitrarily oriented spins of magnitude S{sub 1}/m{sub 1}{sup 2}{approx}0.6 and S{sub 2}/m{sub 2}{sup 2}{approx}0.4 and orbits 9 times prior to merger. The numerical simulation starts with an initial separation of r{approx_equal}11M and orbital parameters determined by 2.5 PN and 3.5 PN evolutions of a quasi-circular binary starting from r=50M. The resulting binaries have very little eccentricity according to the 2.5 PN and 3.5 PN systems, but show eccentricities of e{approx}0.01-0.02 and e{approx}0.002-0.005 in the respective numerical simulations, thus demonstrating that 3.5 PN significantly reduces the eccentricity of the binary compared to 2.5 PN. We perform three numerical evolutions from r{approx_equal}11M with maximum resolutions of h=M/48, M/53.3, M/59.3, to verify numerical convergence. We observe a reasonably good agreement between the PN and numerical waveforms, with an overlap of nearly 99% for the first six cycles of the (l=2, m={+-}2) modes, 91% for the (l=2, m={+-}1) modes, and nearly 91% for the (l=3, m={+-}3) modes. The phase differences between numerical and post-Newtonian approximations appear to be independent of the (l,m) modesmore » considered and relatively small for the first 3-4 orbits. An advantage of the 3.5 PN model over the 2.5 PN one seems to be observed, which indicates that still higher PN order (perhaps even 4.0 PN) may yield significantly better waveforms. In addition, we identify features in the waveforms likely related to precession and precession-induced eccentricity.« less

Electrical modelling approach for discharge analysis of a coaxial DBD tube filled with argon

Dielectric barrier discharges (DBDs) occur in the presence of at least one insulating layer in contact with the discharge between two planar or cylindrical electrodes connected to a high voltage supply. A quartz coaxial DBD tube, filled with argon, has been studied and an electrical model characterizing the discharges has been proposed. The proposed model considers the geometry of the DBD tube, gas gap spacing and the properties of the dielectric barrier material. A sinusoidal voltage up to 2.4 kV peak with frequencies from 20 to 100 kHz has been applied to the discharge electrodes for the generation of microdischarges. By comparisons of visual images and electrical waveforms, the filamentary discharges have been confirmed. The simulated discharge characteristics have been validated by the experimental results. A good correlation between the experimental and simulated results was found, which is used to deduce the circuit impedance and other electrical parameters, in particular, the conduction current, charge accumulation, energy deposited and consumed power during discharges.

Gravitational-wave extraction from neutron-star oscillations: Comparing linear and nonlinear techniques

The main aim of this study is the comparison of gravitational waveforms obtained from numerical simulations which employ different numerical evolution approaches and different wave-extraction techniques. For this purpose, we evolve an oscillating, nonrotating, polytropic neutron-star model with two different approaches: a full nonlinear relativistic simulation (in three dimensions) and a linear simulation based on perturbation theory. The extraction of the gravitational-wave signal is performed via three methods: the gauge-invariant curvature-perturbation theory based on the Newman-Penrose scalar ${\ensuremath{\psi}}_{4}$; the gauge-invariant Regge-Wheeler-Zerilli-Moncrief metric-perturbation theory of a Schwarzschild space-time; some generalization of the quadrupole emission formula.

Analysis of Waveform from Magnetic Printed Perpendicular Hard Disk

A comparison of waveforms from edge printed and bit printed hard disks at various bit lengths has been discussed by using experimental and simulation studies. Experimental results show that the play-back signal from printed hard disk can be used without difficulty as servo signal when bit length is smaller than 0.4 μm. Simulation results and frequency spectra obtained by the Fast Fourier Transform show that the waveform from edge printed and bit printed media distorts as the bit length increases.

Inversion of crosshole seismic data in heterogeneous environments: Comparison of waveform and ray-based approaches

High-resolution tomographic imaging of the shallow subsurface is becoming increasingly important for a wide range of environmental, hydrological and engineering applications. Because of their superior resolution power, their sensitivity to pertinent petrophysical parameters, and their far reaching complementarities, both seismic and georadar crosshole imaging are of particular importance. To date, corresponding approaches have largely relied on asymptotic, ray-based approaches, which only account for a very small part of the observed wavefields, inherently suffer from a limited resolution, and in complex environments may prove to be inadequate. These problems can potentially be alleviated through waveform inversion. We have developed an acoustic waveform inversion approach for crosshole seismic data whose kernel is based on a finite-difference time-domain (FDTD) solution of the 2-D acoustic wave equations. This algorithm is tested on and applied to synthetic data from seismic velocity models of increasing complexity and realism and the results are compared to those obtained using state-of-the-art ray-based traveltime tomography. Regardless of the heterogeneity of the underlying models, the waveform inversion approach has the potential of reliably resolving both the geometry and the acoustic properties of features of the size of less than half a dominant wavelength. Our results do, however, also indicate that, within their inherent resolution limits, ray-based approaches provide an effective and efficient means to obtain satisfactory tomographic reconstructions of the seismic velocity structure in the presence of mild to moderate heterogeneity and in absence of strong scattering. Conversely, the excess effort of waveform inversion provides the greatest benefits for the most heterogeneous, and arguably most realistic, environments where multiple scattering effects tend to be prevalent and ray-based methods lose most of their effectiveness.

High speed scanning of terahertz pulse by a rotary optical delay line

We demonstrate high speed scanning of a time-domain terahertz pulse by a rotary optical delay line (RODL) incorporated into a photoconductive antenna based terahertz system. The delay line of RODL consists of six rotating convex reflective blades with a rotating speed controlled for a wide range of scan repetition rates. It can perform path length scans of 2.1 cm at a scanning speed of 8.4 m/s while maintaining linearity. The comparison of the terahertz temporal waveform and the frequency spectrum measured by using the RODL and a linear stage optical delay line confirms the linearity of the RODL up to 140 ps at high scan repetition rates of 400 scan/s. A high signal-to-noise ratio, up to a few thousand, can be obtained by averaging multiple terahertz pulses at a high scan speed.

Tsunami waveform inversion of the 2007 Bengkulu, southern Sumatra, earthquake

Asbtract We performed tsunami waveform inversions for the Bengkulu, southern Sumatra, earthquake on September 12, 2007 (M w 8.4 by USGS). The tsunami was recorded at many tide gauge stations around the Indian Ocean and by a DART system in the deep ocean. The observed tsunami records indicate that the amplitudes were less than several tens of centimeters at most stations, around 1 m at Padang, the nearest station to the source, and a few centimeters at the DART station. For the tsunami waveform inversions, we adopted 20-, 15- and 10-subfault models. The tsunami waveforms computed from the estimated slip distributions explain the observed waveforms at most stations, regardless of the subfault model. We found that large slips were consistently estimated at the deeper part (>24 km) of the fault plane, located more than 100 km from the trench axis. The largest slips of 6–9 m were located about 100–200 km northwest of the epicenter. The deep slips may have contributed to the relatively small tsunami for its earthquake size. The total seismic moment is calculated as 4.7 × 1021 N m (M w = 8.4) for the 10-subfault model, our preferred model from a comparison of tsunami waveforms at Cocos and the DART station.

OP02.11: Comparison of cardiovascular functional parameters and Doppler flow waveforms in fetuses with two‐vessel cord versus three‐vessel cord at 20–23 weeks gestational age

OP02.11: Comparison of cardiovascular functional parameters and Doppler flow waveforms in fetuses with two‐vessel cord versus three‐vessel cord at 20–23 weeks gestational age