Amplitude Factor Research Articles

Open-Circuit Fault Diagnosis Method in NPC Rectifiers Using Fault-Assumed Strategy

This article proposes a new open-circuit (OC) fault diagnosis method for power switches in three-level neutral-point-clamped (NPC) rectifiers. This method is based on fault assumption by introducing a new voltage deviation for diagnosis, which is the difference between the switching-state-based voltage and the fault-assumed-based voltage, where the fault-assumed-based voltage is the estimated pole voltage when all inner switches are assumed to be in the OC state. After average and sum operations, diagnostic variables are developed from three-phase voltage deviations without extra hardware and precise modeling. Since the fault characteristics of each switch reflected by diagnostic variables are not changed by other concurrent OC faults, multiple-switch faults can be diagnosed in the same way as single-switch faults. As a result, the proposed method can detect both single-switch and multiple-switch faults without complex diagnostic rules and procedures. Besides, adaptive thresholds are designed by considering voltage imbalance, current amplitude, and power factor. Owing to the self-adjusting characteristics of thresholds, the proposed method provides reliable diagnostic results in various operating states of NPC rectifiers and has good robustness against transient changes. Experiments are performed to confirm its effectiveness and robustness.

Simulation and Experiment of Sieving Process of Sieving Device for Tiger Nut Harvester

In order to realize mechanized and efficient harvesting of tiger nuts, study the efficient screening technology of beans and soil in a mechanized harvesting operation and improve the harvesting operation efficiency of crawler-type tiger nut harvesters, a theoretical analysis of the motion process of detritus particles on a sieve surface was conducted to determine the main factors affecting the motion of the particles on the sieve surface. A numerical simulation of the sieving process using the discrete element method was conducted to improve the screening efficiency of tiger nuts. The transport law of the debris particle population was analyzed from different perspectives, such as the average velocity of particle motion, particle distribution rate, screening efficiency and loss rate. The effects of factors such as screen amplitude (SA), vibration frequency (VF) and inclination angle (IA) on the sieving performance of the tiger nut threshing and screening device were investigated. The results show that sieving performance evaluation indexes, such as the average speed of particle movement, particle distribution rate, screening efficiency and loss rate, are non-linearly related to the factors of screen amplitude, vibration frequency and screen inclination angle; the effects of amplitude and frequency on the distribution particle size are consistent and show a gradual increase, with the distribution particle size reaching 3.32 mm at an amplitude of 14 mm and 3.46 mm at a frequency of 22 Hz. In the sieving process, the average velocity of the particle population decreases gradually along the direction of motion, and the influence of each factor on the average velocity of the particle population in the motion of the detritus is similar, all showing an increasing trend. This study can provide a reference for exploring the transport law of particles and the efficient screening technology of tiger nuts. Field harvesting tests showed that the screening efficiency and loss rate were 92.87% and 0.83%, respectively, at a screen amplitude of 14 mm, a vibration frequency of 10 Hz and an inclination angle of 2°, and the test results corresponded to the simulation results and met the design requirements of the tiger nut harvester. This study can provide reference for the investigation of the particle transport law and efficient screening technology for tiger nuts.

The influence of pressure waves in tidal gravity records

For the reduction of atmospheric effects, observed gravity has initially been corrected by using the computed barometric admittance k of the in situ measured pressure, expressed in nms−2/hPa units and estimated by least squares method. However, the local pressure changes alone cannot account for the atmospheric mass attraction and loading when the coherent pressure field exceeds a specific size, i.e., with increasing periodicities. To overcome this difficulty, it is necessary to compute the total atmospheric effect at each station using the global pressure field. However, the direct subtraction of the total gravity effect, provided by the models of pressure correction, is not yet satisfactory for S2 and other tidal components, such as K2 and P1, which include solar heating pressure tides. This paper identifies the origin of the problem and presents strategies to obtain a satisfactory solution.First, we set up a difference vector between the tidal factors of M2 and S2 after correction of the pressure and ocean tides effects. This vector, hereafter denoted as RES, presents the advantage of being practically insensitive to calibration errors. The minimum discrepancy between the tidal parameters of M2 and S2 corresponds to the minimum of the RES vector norm d.Secondly we adopt the hybrid pressure correction method, separating the local and the global pressure contribution of the models and replacing the local contribution by the pressure measured at the station multiplied by an admittance kATM.We tested this procedure on 8 stations from the IGETS superconducting gravimeters network (former GGP network). For stations at an altitude lower than 1000 m, the value of dopt is always smaller than 0.0005. The discrepancy between the tidal parameters of the M2 and S2 waves is always lower than 0.05% on the amplitude factors and 0.025° on the phases. For these stations, a correlation exists between the altitude and the value kopt. The results at the three Central European stations Conrad, Pecny and Vienna are in excellent agreement (0.05%) with the DDW99NH model for all the main tidal waves.

Insights on the Hydrodynamics of Chiari Malformation.

Background: We propose that the appearance of a ptosis of the cerebellar tonsils and syringomyelia is linked to its own hemohydrodynamic mechanisms. We aimed to quantify cerebrospinal fluid (CSF) and cerebral blood flow to highlight how neurofluid is affected by Chiari malformations type 1(CMI) and its surgery. Methods: We retrospectively included 21 adult patients with CMI who underwent pre- and postoperative phase contrast MRI (PCMRI) during the period from 2001 to 2017. We analyzed intraventricular CSF, subarachnoid spaces CSF, blood, and tonsils pulsatilities. Results: In preoperative period, jugular venous drainage seems to be less preponderant in patients with syringomyelia than other patients (venous correction factor: 1.49 ± 0.4 vs. 1.19 ± 0.1, p = 0.05). After surgery, tonsils pulsatility decreased significantly (323 ± 175 μL/cardiac cycle (CC) vs. 194 ± 130 μL/CC, p = 0.008) and subarachnoid CSF pulsatility at the foramen magnum increased significantly (201 ± 124 μL/CC vs. 363 ± 231 μL/CC, p = 0.02). After surgery, we found a decrease in venous flow amplitude (5578 ± 2469 mm3/s vs. 4576 ± 2084 mm3/s, p = 0.008) and venous correction factor (1.98 ± 0.3 vs. 1.20 ± 0.3 mm3/s, p = 0.004). Conclusions: Phase-contrast MRI could be a useful additional tool for postoperative evaluation and follow-up, and is complementary to morphological imaging.

Efficiency characteristics for changes in amplitude and power factor of diode‐clamped linear amplifier unequally divided voltage power supply

AbstractA diode‐clamped linear amplifier (DCLA) is proposed to realize low electromagnetic interference (EMI) caused by switching operations. A new concept of the DCLA, namely the higher efficiency unequally divided voltage power supply DCLA (DCLA‐UeDV), is proposed. In previous studies, the optimal voltage ratio was derived, and a 1.7% points improvement in efficiency was realized for a rated unity power factor load. However, it has not been examined whether the conversion efficiency can be improved, except during the rated operation. In this study, operation of the DCLA is analyzed for changes in the amplitude of the output voltage and load power factor. Then, the advantageous operating region of the DCLA‐UeDV against DCLA‐eDV is clarified.

Compensating Method of Equivalent Current Sources of LSI-Core Macromodel Considering Voltage Fluctuations in On-Chip Power Distribution Network

Electro-magnetic compatibility (EMC) macromodels of a large-scale integrated (LSI) circuit core have been proposed to predict conducted RF emission and power integrity issues not only on a printed circuit board but also inside an LSI. They are equivalent circuit models that consist of lumped element impedance blocks of an LSI-core and equivalent current sources expressing internal switching activities. In conventional macromodeling, equivalent current sources have been extracted under ideal power supply conditions, i.e., with constant supply voltage. However, there exists transient supply voltage fluctuations in an actual on-chip power distribution network (PDN), and the operating current and its equivalent current sources are expected to vary with such fluctuations. Such issues with transient supply voltage fluctuations have not been extensively investigated. We propose a method of compensating the equivalent current sources of a macromodel by introducing amplitude and time correction factors, taking into account the voltage fluctuations in an on-chip PDN.

An improved one-dimensional sinusoidal band-stop filter using weighted techniques

In this paper, the weighting techniques are directly acted on traditional 1D sinusoidal electromagnetic bandgap (EBG) structures. The proposed 1D weighted EBG band-stop filter is theoretically designed by using coupled-mode theory, and the coupling coefficient amplitudes of the 1D sinusoidal EBG structure are directly weighted using window functions. The passband ripple, reflected sidelobes, and bandwidth of the band-stop filter are improved using weighted window functions, and the bandgap depth is adjusted by changing the amplitude factor of weighting functions. For validation, the fabrication and measurements have also been done for the proposed filter. The measurement and simulation results have a close match, and the design concept is verified.

Derived brackets in bosonic string sigma-model

We study the worldsheet theory of bosonic string from the point of view of the BV formalism. We explicitly describe the derived Poisson structure which arises when we expand the Master Action near a Lagrangian submanifold. The resulting higher Poisson brackets are all degenerate and essentially constant along their symplectic leaves. Deformations of the worldsheet complex structures define a family of Lagrangian submanifolds, parametrized by Beltrami differential. The worldsheet action depends nonlinearly on the Beltrami differential, but the structure of nonlinearity is governed by the BV Master Equation. This helps to clarify the mechanism of holomorphic factorization of string amplitudes.

Near Field 3-D Millimeter-Wave SAR Image Enhancement and Detection with Application of Antenna Pattern Compensation

In this paper, a novel near-field high-resolution image focusing technique is proposed. With the emergence of Millimeter-wave (mmWave) devices, near-field synthetic aperture radar (SAR) imaging is widely used in automotive-mounted SAR imaging, UAV imaging, concealed threat detection, etc. Current research is mainly confined to the laboratory environment, thus ignoring the adverse effects of the non-ideal experimental environment on imaging and subsequent detection in real scenarios. To address this problem, we propose an optimized Back-Projection Algorithm (BPA) that considers the loss path of signal propagation among space by converting the amplitude factor in the echo model into a beam-weighting. The proposed algorithm is an image focusing algorithm for arbitrary and irregular arrays, and effectively mitigates sparse array imaging ghosts. We apply the 3DRIED dataset to construct image datasets for target detection, comparing the kappa coefficients of the proposed scheme with those obtained from classic BPA and Range Migration Algorithm (RMA) with amplitude loss compensation. The results show that the proposed algorithm attains a high-fidelity image reconstruction focus.

Development of a validation technique for road surface profile applicable to point cloud data

In recent years, various information and communication technology (ICT) devices measuring three-dimensional (3D) point cloud data have been developed and widely used for the application of pavement surface investigation. However, ICT devices have generally been developed not only for measuring road surface profiles but for various geo-reference point clouds. In this background, the validation of surface profiles acquired with ICT devices fulfils an important role in proving the reliability of measurement result composed by point clouds. This study proposes a wavelet transform agreement (WTA) which involves a normalization factor of profile amplitude for further improvement in the wavelet-based coherence technique. The WTA analysis allows evaluating similarity/dissimilarity of two profiles considering both the location and wavelength simultaneously. For this purpose, a terrestrial laser scanner (TLS), a mobile mapping system (MMS), and an unmanned aerial vehicle (UAV) are employed to prove the advantage of WTA in practical applications. As a result, the advantages of WTA analysis are clearly recognized in the optimization for the measurement interval of TLS, the multi-line measurement of MMS for ride quality improvement of a pavement, and the efficient operation of UAV in terms of the flight altitude. This paper also shows the identification of aging development for surface roughness over time in terms of locations and wavelengths. These findings help not only to guarantee the accuracy of profile measurements but to realize the sophisticated way of using 3D point clouds acquired with ICT devices. The outcomes of this study contribute to the increase of productivity for pavement works with improving the quality of surface profile measurement. • Wavelet agreement modifies wavelet transform coherence for road profile analysis. • Profile validation becomes reliable with wavelet agreement analysis. • Wavelet agreement performs profile validation keeping locations and wavelengths. • Wavelet-based method has an affinity with three-dimensional point clouds. • Profile validation improves operational efficiency of ICT devices.

"Dual use of alcohol and cannabis among college students: A reinforcer pathologies approach." Correction to Reed et al. (2021).

Reports an error in "Dual use of alcohol and cannabis among college students: A reinforcer pathologies approach" by Gideon P. Naudé, Derek D. Reed, Tyler J. Thornton and Michael Amlung (Experimental and Clinical Psychopharmacology, 2021[Aug], Vol 29[4], 407-417). In the original article, in the Method section under Principal Components Analyses, it reads "We used a loading of ≥ 4.0 ... " when it should read "≥ 0.40." The correct loading criterion is listed in the Table 3 note. Analyses were run using the correct criterion. In Table 3, the loading for BP1 under the alcohol amplitude factor is "-0.4" when it should be "-0.04." The online version of this article has been corrected. (The following abstract of the original article appeared in record 2020-25392-001). The reinforcer pathologies model proposes 2 behavioral economic constructs interact in addiction: operant demand and delay discounting. These constructs manifest as behavioral markers of addiction in the form of excessive reinforcer value and strong preference for immediate access and consumption of this reinforcer despite suboptimal long-term outcomes. The first aim of this investigation was to identify the degree to which delay discounting (of money and alcohol) and demand for alcohol differ between college student drinkers (N = 185) who do and do not co-use cannabis. As a second aim, we sought to replicate the 2-factor solution for alcohol and cannabis demand within a college sample. Results suggest dual users have significantly stronger Persistence and Amplitude for alcohol, demonstrate steeper delay discounting of alcoholic drinks, and are at greater risk for alcohol use disorder than individuals who drink yet do not use cannabis. These results provide further support for the reinforcer pathologies model and contribute to the literature on dual-substance use in the college population. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Asymptotic solution for interface crack between two materials governed by dipolar gradient elasticity: Amplitude factor evaluation

The procedure of assessing the amplitude factors in the asymptotic solution for the interface crack between the materials obeying the isotropic gradient elasticity is developed. The boundary conditions at tip of the crack are applied to assemble the eigenvalue problem from which the stress exponents with the appropriate eigenvectors of the regular and auxiliary solutions are evaluated. The amplitude factors of the asymptotic solution are computed from the two-state integrals in which the regular, auxiliary and particular finite element solution represent the independent equilibrium states. The concept of the two-state integral method is based on Betti’s reciprocal theorem, which is frequently utilized in classical fracture mechanics. The present work extends its application to the general fracture problem in strain gradient elasticity.

Linear Nash-Greene fluctuations on the evolution of S_8 and H_0 tensions

We present the perturbation equations in an embedded four space-time from the linear Nash-Greene fluctuations of background metric. In the context of a five-dimensional bulk, we show that the cosmological perturbations are only propagated by the gravitational tensorial field equation. In Newtonian conformal gauge, we study the matter density evolution in sub-horizon regime and on how such scale may be affected by the extrinsic curvature. We apply a joint likelihood analysis to the data by means of the Markov Chain Monte Carlo (MCMC) method for parameter estimation using a pack of recent datasets as the Pantheon Supernovae type Ia, the Baryon Acoustic Oscillations (BAO) from DR12 galaxy sample and Dark Energy Survey (DESY1). We discuss the tensions on the Hubble constant H_0 and the growth amplitude factor S_8 of the observations from Planck 2018 Cosmic Microwave Background (CMB) and the local measurements of H_0 with Hubble Space Telescope (HST) photometry and Gaia EDR3. As a result, we obtain an alleviation below sim 1sigma in the contours (S_8-varOmega _m) at 68.4% confidence level (CL) when compared with DESY1 data. On the other hand, the H_0 tension persists with sim 2.6sigma at 68.4% CL and 1.95sigma at 95.7% CL, aggravated with the inclusion of BAO data.

Personalized Neurophysiological and Neuropsychological Assessment of Patients with Left and Right Hemispheric Damage in Acute Ischemic Stroke.

The leading factors of post-stroke disability are motor disorders and cognitive dysfunctions. The aim of the study was to identify and provide a rationale for the variable early cognitive dysfunction in right and left hemispheric damage in patients with acute stroke. The study included 80 patients diagnosed with ischemic stroke. All patients were assessed for cognitive status, depression, fatigue and anxiety. For objectification, the method of evoked potentials (P300) and neuroimaging were used. Our findings revealed distinguishing features of cognitive dysfunction and identified a combination of the most informative markers characteristic of right and left hemispheric damage in patients with acute ischemic stroke. In patients with damage to the left hemisphere, a predominance of dysregulation syndrome (decrease in executive function and attention) was revealed, accompanied by various disorders such as severe anxiety and fatigue. The causes of this cognitive dysfunction may be directly related to stroke (damage to subcortical structures), as well as to a preexisting reduction in higher mental functions associated with age and vascular conditions. Cognitive impairments in patients with lesions of the right hemisphere were characterized by polymorphism and observed in the mental praxis, speech (with predominant semantic component) and abstract thinking domains. They are closely linked to each other and are more related to the lateralization of the lesion and preexisting neurodegeneration than to the localization of the ischemic lesion. The study of P300-evoked potentials is a good tool for confirming cognitive dysfunction. The latent period of the P300 wave is more sensitive to neurodegeneration, while the amplitude factor characterizes vascular pathology to a greater extent. The results of the study provide a rationale for a comprehensive assessment of lateralization, stroke localization, underlying diseases, neurophysiological parameters and identified cognitive impairments when developing a plan of rehabilitation and neuropsychological measures aimed at cognitive and emotional recovery of patients both in the acute phase of ischemic stroke and when selecting further personalized rehabilitation programs.

Effect of the conical diffuser angle on the confined swirling flow induced Precessing Vortex Core

This paper presents the effect of the conical diffuser angle (θ=0°,2°,4°) on the Precessing Vortex Core (PVC) induced in confined swirling airflows generated by axial swirlers with two swirl number (Sw=1.1,0.7). Planar Particle Image Velocimetry (2D-PIV) synchronized with unsteady wall pressure fluctuation measurements are performed to identify the Strouhal number of the precession frequency and pressure fluctuations amplitude induced by the PVC, as well as the PVC parameters related to its phase-averaged vortex structure. Furthermore, the distribution of pressure recovery rate based on the mass flow averaged pressure, and the relationship between the local axial pressure gradient and the local PVC structure is also investigated to understand the relationship between the PVC parameters and pipe geometries. These relationships are derived from transient simulations with the Shear Stress Transport Curvature Correction model, since the pressure field data cannot be obtained from the experiments conducted in this paper. Experimental and numerical results in pipe configurations 1 (diffuser followed by a straight pipe) and 2 (diffuser followed by an open exit) clarify the diffuser angle effect. As the diffuser angle increases, the Strouhal number decreases, whereas the pressure fluctuations amplitude increases. Moreover, the PVC parameters are also affected by increased diffuser angle: the vortex trajectory radius is enlarged, and the helical vortex pitch is shortened. In addition, the geometry change (from diffuser to straight pipe) leads to a sudden change in the vortex pitch and a modification of the pressure recovery rate evolution. The vortex structure in the conical diffuser is affected by a difference in the diffuser angle, but the latter does not affect the vortex structure in the downstream straight pipe. This highlights that the local vortex pitch depends only on the local pipe geometry. Finally, a theoretical model of the relationship between the pressure fluctuation amplitude and PVC parameters is proposed, and the relationship between the local pressure gradient and the local vortex trajectory radius gradient is clarified. The amplitude factor Cp∗ is a function of the dimensionless vortex trajectory radius r∗. Positive or negative local pressure gradient leads to the mitigation or promotion of the PVC development.

U-Channel Color Transparency Observables

The paper proposes to study the onset of color transparency in hard exclusive reactions in the backward regime. Guided by the encouraging Jefferson Laboratory (JLab) results on backward π and ω electroproduction data at moderate virtuality Q2, which may be interpreted as the signal of an early scaling regime, where the scattering amplitude factorizes in a hard coefficient function convoluted with nucleon to meson transition distribution amplitudes, the study shows that investigations of these channels on nuclear targets opens a new opportunity to test the appearance of nuclear color transparency for a fast-moving nucleon.

Amplitude-initiated open hysteresis loop of <i>P</i>-wave attenuation in sandstone: experimental study

In the area of solid state physics and materials science, new knowledge has been attained in recent years about micro-nano-plasticity using high-precision measurements at low stresses and strain. Rock microplasticity is currently poorly understood, but in the future it may prove useful in resolving problems of a fundamental and applied nature. This study examines the effect of cyclically varying pulse amplitude and wave velocity on the attenuation parameters of longitudinal wave (P-wave) in sandstone. Laboratory measurements were performed on rock specimens using the reflected wave method in the frequency range of 0.5–1.4 MHz at five values of strain amplitude ~ (0.5-2.0)10 –6 . Trial simulations were performed, in order to establish the effect of amplitude-dependent wave velocity on the parameters of wave attenuation in the sandstone. Wave attenuation behavior under combined action of the amplitude-dependent factor and wave velocity deviation is complex. The change in strain amplitude shifts the attenuation peak 1/ Q p ( f ) in the attenuation-frequency coordinates. The maximum change in peak attenuation value due to the amplitude factor and wave velocity deviation reaches 3–4 %. An open wave attenuation hysteresis loop was identified as a consequence of the closed amplitude cycle A1(+) --- A1(+) --- A1(–), where A1(+) = A1(–). Open attenuation hysteresis occurs both in the cases of constant and variable wave velocities. The length of the open part of the attenuation hysteresis loop relative to the peak value of the attenuation is as follows: for constant wave speed, 62.63 %, in the mode of increasing wave speed, 91.58 %; and, in the mode of decreasing wave speed, 47.01 %. The effect of open hysteresis of wave attenuation in sandstone can be explained by the action of microplastic deformation detected in the experiments.

Test of ocean tide loading models on the basis of strain data measured at the Vyhne Tidal Station, Slovakia

Tidal strain time series recorded at the Vyhne Tidal Station are used to test thirteen different ocean tide loading models. Ten models have been calculated using SPOTL: EOT11a, HAMTIDE11a, OSU.TPXO72atlas, OSU.TPXO72, TPX070, DTU10, CSR4.0, FES2004, FES95.2.1, SCHW1 and three other models were chosen from the Free Ocean Tide Loading Provider (FOTLP) created by Scherneck and Bos: FES2012, FES2014b, GOT00.2. Hourly sampled strain data, corrected for temperature, were subjected to correction for ocean tide loading. The test of models was focused on the diurnal and semi-diurnal tidal harmonic constituents O1, P1, K1 and M2. A negligible difference between the individual global ocean tide loading models was only found mainly due to using different Earth models and Green functions. The amplitude factors for O1, P1, K1 and M2 derived from the measurements are 1.019, 1.226, 0.842 and 1.131, respectively. The average amplitude factors for these tidal components were obtained after ocean load correction using SPOTL routines: 1.121, 1.332, 0.916, 1.283, and in the case of the three models using FOTLP: 1.046, 1.486, 1.067, 1.317. The corrected amplitude factor became closer to the theoretical value only for K1.

KLT factorization of nonrelativistic string amplitudes

We continue our study of the Kawai-Lewellen-Tye (KLT) factorization of winding string amplitudes in [1]. In a toroidal compactification, amplitudes for winding closed string states factorize into products of amplitudes for open strings ending on an array of D-branes localized in the compactified directions; the specific D-brane configuration is determined by the closed string data. In this paper, we study a zero Regge slope limit of the KLT relations between winding string amplitudes. Such a limit of string theory requires a critically tuned Kalb-Ramond field in a compact direction, and leads to a self-contained corner called nonrelativistic string theory. This theory is unitary, ultraviolet complete, and its string spectrum and spacetime S-matrix satisfy nonrelativistic symmetry. Moreover, the asymptotic closed string states in nonrelativistic string theory necessarily carry nonzero windings. First, starting with relativistic string theory, we construct a KLT factorization of amplitudes for winding closed strings in the presence of a critical Kalb-Ramond field. Then, in the zero Regge limit, we uncover a KLT relation for amplitudes in nonrelativistic string theory. Finally, we show how such a relation can be reproduced from first principles in a purely nonrelativistic string theory setting. We will also discuss connections to the amplitudes of string theory in the discrete light cone quantization (DLCQ), a method that is relevant for Matrix theory.

Modeling of structured light projection on vibrating surfaces: Amplitude and phase mapping by fringe visibility evaluation

Vibration analysis is an extremely important issue in many fields of production systems like quality control as well as maintenance procedures. In this work it is theoretically studied the behavior of structured light in the form of straight sinusoidal fringes projected on vibrating objects. It was shown that by time averaging the moving fringes on the vibrating surface the resulting light pattern can be described with the help of the zero-order Bessel function of the vibration amplitude and constant factors related to the optical setup geometry. A simple formula was derived allowing to determine the Bessel function by combining the projected light patterns in different object configurations. The amplitude distribution in turn was retrieved from the Bessel function with the help of the explicit Euler method. It was also demonstrated that the phase mapping can be carried out by illuminating the object with a properly oscillating light pattern. The vibration analyses of a rectangular bar and of a square plate was simulated and its possible applications were pointed out.