Academic literature on the topic 'Time and Frequency Plot (TAFPLOT)'
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Journal articles on the topic "Time and Frequency Plot (TAFPLOT)"
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Peng, Fu Min, and Bin Fang. "Stabilizing Gain Regions of PID Controller for Time Delay Systems." Applied Mechanics and Materials 313-314 (March 2013): 432–37. http://dx.doi.org/10.4028/www.scientific.net/amm.313-314.432.
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Based on the inverse Nyquist plot, this paper proposes a method to determine stabilizing gain regions of PID controller for time delay systems. According to the frequency characteristic of the inverse Nyquist plot, it is confirmed that the frequency range is used for stability analysis, and the abscissas of two kind key points are obtained in this range. PID gain is divided into several regions by abscissas of key points. Using an inference and two theorems presented in the paper, the stabilizing PID gain regions are determined by the number of intersections of the inverse Nyquist plot and the vertical line in the frequency range. This method is simple and convenient. It can solve the problem of getting the stabilizing gain regions of PID controller for time delay system.
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Piedad, Eduardo Jr, Yu-Tung Chen, Hong-Chan Chang, and Cheng-Chien Kuo. "Frequency Occurrence Plot-Based Convolutional Neural Network for Motor Fault Diagnosis." Electronics 9, no. 10 (October 18, 2020): 1711. http://dx.doi.org/10.3390/electronics9101711.
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A novel motor fault diagnosis using only motor current signature is developed using a frequency occurrence plot-based convolutional neural network (FOP-CNN). In this study, a healthy motor and four identical motors with synthetically applied fault conditions—bearing axis deviation, stator coil inter-turn short circuiting, a broken rotor strip, and outer bearing ring damage—are tested. A set of 150 three-second sampling stator current signals from each motor fault condition are taken under five artificial coupling loads (0, 25%, 50%, 75% and 100%). The sampling signals are collected and processed into frequency occurrence plots (FOPs) which later serve as CNN inputs. This is done first by transforming the time series signals into its frequency spectra then convert these into two-dimensional FOPs. Fivefold stratified sampling cross-validation is performed. When motor load variations are considered as input labels, FOP-CNN predicts motor fault conditions with a 92.37% classification accuracy. It precisely classifies and recalls bearing axis deviation fault and healthy conditions with 99.92% and 96.13% f-scores, respectively. When motor loading variations are not used as input data labels, FOP-CNN still satisfactorily predicts motor condition with an 80.25% overall accuracy. FOP-CNN serves as a new feature extraction technique for time series input signals such as vibration sensors, thermocouples, and acoustics.
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Yusof, M. F. M., Mahadzir, Mohd Fairusham Ghazali, and Mohd Rafiqul Islam. "Analysis of an Air Borne Acoustic Signatures from Welding Process Using Empirical Mode Decomposition." Advanced Materials Research 889-890 (February 2014): 770–75. http://dx.doi.org/10.4028/www.scientific.net/amr.889-890.770.
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This work present the application of Empirical Mode Decomposition (EMD) to analyze the air borne acoustic signatures commenced during welding process. In order to achieve goals, bead-on plate welding was done onto the carbon steel specimen using Metal Inert Gas Welding. At the same moment, the microphone with operating frequency of 31.5 Hz to 8 kHz used to collect air borne acoustic signatures. In analysis part, Empirical Mode Decomposition has been applied to the acoustic signals and the selected Intrinsic Mode Function (IMF) was presented in frequency-distance plot using spectrogram. Based on the analysis results, there were 3 significant IMF has been found. Those were IMF mode 3, mode 5 and mode 8 which lie within the frequency of 1500 Hz to 4500 Hz, 200 Hz to 800 Hz, and 40 Hz to 80 Hz respectively. The frequency-distance plot from spectrogram of IMF mode 3 showed a significant pattern which can be related with the discontinuity of welding. The discontinuity appears wherever low amplitude power detected in the frequency-distance plot of IMF mode 3. Moreover, the frequency-distance plot of IMF mode 5 and mode 8 can be significantly related with the spatter and weld pool oscillation condition. High power amplitude in frequency-distance plot of IMF mode 8 can indicates the offset of weld pool oscillation frequency and cause the existence of higher amount of spatter which resulting the high power amplitude in frequency-distance plot of IMF mode 5. In summary, it can be conclude that the application of EMD in the analysis of air borne acoustic signatures allow the detection of several phenomena in welding process which might lead to defect once in a time. This was found to be significant in the process of developing the online welding quality monitoring.
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Carrasco, M. J. Gaitán, R. González, S. "Correlation among Poincare´plot indexes and time and frequency domain measures of heart rate variability." Journal of Medical Engineering & Technology 25, no. 6 (January 2001): 240–48. http://dx.doi.org/10.1080/03091900110086651.
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Chen, Shih Tsung, Chia Yi Chou, and Li Ho Tseng. "Recurrence Plot Analysis of HRV for Exposure to Low-Frequency Noise." Advanced Materials Research 1044-1045 (October 2014): 1251–57. http://dx.doi.org/10.4028/www.scientific.net/amr.1044-1045.1251.
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Previous studies have indicated that the chronic effects of exposure to low-frequency noise causes annoyance. However, during the past two decades, most studies have employed questionnaires to characterize the effects of noise on psychosomatic responses. This study investigated cardiovascular activity changes in exposure to low-frequency noise for various noise intensities by using recurrence plot analysis of heart rate variability (HRV) estimation. The authors hypothesized that distinct noise intensities affect cardiovascular activity, which would be reflected in the HRV and recurrence quantification analysis (RQA) parameters. The test intensities of noises were no noise, 70-dBC, 80-dBC, and 90-dBC. Each noise level was sustained for 5 min, and the electrocardiogram (ECG) was recorded simultaneously. The cardiovascular responses were evaluated using RQA of the beat-to-beat (RR) intervals obtained from ECG signals. The results showed that the mean RR interval variability and mean blood pressure did not substantially change relative to the noise levels. However, the length of the longest diagonal line (Lmax) of the RQA of the background noise (no noise) condition was significantly lower than the 70-dBC, 80-dBC, and 90-dBC noise levels. The laminarity showed significant changes in the noise levels of various intensities. In conclusion, the RQA-based measures appear to be an effective tool for exposure to low-frequency noise, even in short-term HRV time series.
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Georgieva-Tsaneva, Galya, Evgeniya Gospodinova, Mitko Gospodinov, and Krasimir Cheshmedzhiev. "Cardio-Diagnostic Assisting Computer System." Diagnostics 10, no. 5 (May 19, 2020): 322. http://dx.doi.org/10.3390/diagnostics10050322.
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The mathematical analysis and the assessment of heart rate variability (HRV) based on computer systems can assist the diagnostic process with determining the cardiac status of patients. The new cardio-diagnostic assisting computer system created uses the classic Time-Domain, Frequency-Domain, and Time-Frequency analysis indices, as well as the nonlinear methods (Poincaré plot, Recurrence plot, Hurst R/S method, Detrended Fluctuation Analysis (DFA), Multi-Fractal DFA, Approximate Entropy and Sample Entropy). To test the feasibility of the software developed, 24-hour Holter recordings of four groups of people were analysed: healthy subjects and patients with arrhythmia, heart failure and syncope. Time-Domain (SDNN < 50 ms, SDANN < 100 ms, RMSSD < 17 ms) and Frequency-Domain (the spectrum of HRV in the LF < 550 ms2, and HF < 540 ms2) parameter values decreased in the cardiovascular disease groups compared to the control group as a result of lower HRV due to decreased parasympathetic and increased sympathetic activity. The results of the nonlinear analysis showed low values of (SD1 < 56 ms, SD2 < 110 ms) at Poincaré plot (Alpha < 90 ms) at DFA in patients with diseases. Significantly reducing these parameters are markers of cardiac dysfunction. The examined groups of patients showed an increase in the parameters (DET% > 95, REC% > 38, ENTR > 3.2) at the Recurrence plot. This is evidence of a pathological change in the regulation of heart rhythm. The system created can be useful in making the diagnosis by the cardiologist and in bringing greater accuracy and objectivity to the treatment.
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Brennan, Michael, Marimuthu Palaniswami, and Peter Kamen. "Poincaré plot interpretation using a physiological model of HRV based on a network of oscillators." American Journal of Physiology-Heart and Circulatory Physiology 283, no. 5 (November 1, 2002): H1873—H1886. http://dx.doi.org/10.1152/ajpheart.00405.2000.
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In this paper, we develop a physiological oscillator model of which the output mimics the shape of the R-R interval Poincaré plot. To validate the model, simulations of various nervous conditions are compared with heart rate variability (HRV) data obtained from subjects under each prescribed condition. For a variety of sympathovagal balances, our model generates Poincaréplots that undergo alterations strongly resembling those of actual R-R intervals. By exploiting the oscillator basis of our model, we detail the way that low- and high-frequency modulation of the sinus node translates into R-R interval Poincaré plot shape by way of simulations and analytic results. With the use of our model, we establish that the length and width of a Poincaré plot are a weighted combination of low- and high-frequency power. This provides a theoretical link between frequency-domain spectral analysis techniques and time-domain Poincaré plot analysis. We ascertain the degree to which these principles apply to real R-R intervals by testing the mathematical relationships on a set of data and establish that the principles are clearly evident in actual HRV records.
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Alqamari, Muhammad, Chairani Hanum, and Hamidah Hanum. "PERTUMBUHAN DAN HASIL TIGA VARIETAS CABAI MERAH (Capsicum annuum L.) DENGAN APLIKASI KALIUM SULFAT." Jurnal Pertanian Tropik 3, no. 3 (December 1, 2016): 249–55. http://dx.doi.org/10.32734/jpt.v3i3.2984.
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This research was conducted in the experimental field of Agricultural Faculty of North Sumatra Muhammadiyah University with a height of ± 27 meters dpl, held in july - nov 2012. This study aims to determine the best dose frequency of k2so4 on growth and the result of red chili varieties. This research was conducted using the split plot design with two factors; the varieties factor as the main plot with 3 kinds of varieties, named, V1 = TM 999, V2 = Lado, V3 = Landung; and the dose and frequency factors of k2so4 as subplot with 10 stages of treatment which is: K0 = 0, dose = 1.5 g / liter frequency 6 x (K1), 9 x (K2) and 12 x (K3), dose = 3 grams / liter frequency 6 x (K4), 9 x (K5) and 12 x (K6), dose = 4.5 g / liter frequency 6 x (K7), 9 x (K8) and 12 x (K9). The fertilizing was cunducted in the morning at 06.30 am - 08.30 am. The measured variables are plant height, numbers of chlorophyll, age of flower, numbers of flower, the percentage of deciduous fruit, weight of fruit/plot. Varieties show significant differences in plant height, numbers of chlorophyll leaf, age of flower, numbers of flower, the percentage of deciduous fruit, numbers of fruit, weight of fruit, weight of fruit per plot, moisture content and storability. Dose and frequency treatment of potassium sulfate is significantly different from controls. The best dose and frequency of this research is K9 which is 4.5 g/liter k2so4 with 12 time frequency during the growing season in TM 999 and Landung while the varieties of Lado are at dose of 3 g/liter of water with 12 times in giving (K5).
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Marino, Stefano, and Arturo Alvino. "Detection of Spatial and Temporal Variability of Wheat Cultivars by High-Resolution Vegetation Indices." Agronomy 9, no. 5 (May 5, 2019): 226. http://dx.doi.org/10.3390/agronomy9050226.
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An on-farm research study was carried out on two small-plots cultivated with two cultivars of durum wheat (Odisseo and Ariosto). The paper presents a theoretical approach for investigating frequency vegetation indices (VIs) in different areas of the experimental plot for early detection of agronomic spatial variability. Four flights were carried out with an unmanned aerial vehicle (UAV) to calculate high-resolution normalized difference vegetation index (NDVI) and optimized soil-adjusted vegetation index (OSAVI) images. Ground agronomic data (biomass, leaf area index (LAI), spikes, plant height, and yield) have been linked to the vegetation indices (VIs) at different growth stages. Regression coefficients of all samplings data were highly significant for both the cultivars and VIs at anthesis and tillering stage. At harvest, the whole plot (W) data were analyzed and compared with two sub-areas characterized by high agronomic performance (H) yield 20% higher than the whole plot, and low performances (L), about 20% lower of yield related to the whole plot). The whole plot and two sub-areas were analyzed backward in time comparing the VIs frequency curves. At anthesis, more than 75% of the surface of H sub-areas showed a VIs value higher than the L sub-plot. The differences were evident also at the tillering and seedling stages, when the 75% (third percentile) of VIs H data was over the 50% (second percentile) of the W curve and over the 25% (first percentile) of L sub-plot. The use of high-resolution images for analyzing the frequency value of VIs in different areas can be a useful approach for the detection of agronomic constraints for precision agriculture purposes.
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Zhan, Wen Lian, and Jing Fang Wang. "Voice Activity Detection Based on Nonlinear Processing Techniques." Applied Mechanics and Materials 198-199 (September 2012): 1560–66. http://dx.doi.org/10.4028/www.scientific.net/amm.198-199.1560.
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Hilbert-Huang transform is developed in recent years dealing with nonlinear, non-stationary signal analysis of the complete local time-frequency method, recurrence plot method is a recursive nonlinear dynamic behavior of time series method of reconstruction. In this paper, Hilbert-Huang Transform empirical mode decomposition (EMD) and the recurrence plot (RP) method, a new voice activity detection algorithm. Firstly, through the speech and noise based on the empirical mode decomposition and multi-scale features of the different intrinsic mode function (IMF) on a time scale filtering and nonlinear dynamic behavior of the recurrence plot method, quantitative Recursive analysis of statistical uncertainty for endpoint detection. Simulation results show that the method has a strong non-steady-state dynamic analysis capabilities, in low SNR environment more accurately than the traditional method to extract the start and end point of the speech signal, robustness.
Dissertations / Theses on the topic "Time and Frequency Plot (TAFPLOT)"
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Saboisky, Julian Peter Clinical School Prince of Wales Hospital Faculty of Medicine UNSW. "Neural drive to human respiratory muscles." Publisher:University of New South Wales. Clinical School - Prince of Wales Hospital, 2008. http://handle.unsw.edu.au/1959.4/42792.
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This thesis addresses the organisation of drive to human upper airway and inspiratory pump muscles. The characterisation of single motor unit activity is important as the discharge frequency or timing of discharge of each motor unit directly reflects the output of single motoneurones. Thus, the firing properties of a population of motor units is indicative of the neural drive to the motoneurone pool. The experiments presented in Chapter 2 measured the recruitment time of five inspiratory pump muscles (diaphragm, scalene, second parasternal intercostal, and third and fifth dorsal external intercostal muscles) during normal quiet breathing and quantified the timing and magnitude of drive reaching each muscle. Chapter 3 examined the EMG activity of a major upper airway muscle (the genioglossus). The single motor units of the genioglossus display activity that can be grouped into six types based on its association or lack of association with respiration. The types of activity are termed: Inspiratory Phasic, Inspiratory Tonic, Expiratory Phasic, Expiratory Tonic, Tonic, and Tonic Other. A new method is presented in Chapter 4 to illustrate large amounts of data from single motor units recorded from respiratory muscles in a concise manner. This single figure displays for each motor unit, the recruitment time and firing frequency, the peak discharge frequency and its time, and the derecruitment time and its frequency. This method, termed the time-and-frequency plot, is used to demonstrate differences in behaviour between populations of diaphragm (Chapter 2) and genioglossus (Chapter 3) motoneurones. In Chapter 5, genioglossus activity during quiet breathing is compared between a group of patients with severe OSA and healthy control subjects. The distribution of central drive is identical between the OSA and control subjects with the same proportion of the six types of motor unit activity in both groups. However, there are alterations in the onset time of Inspiratory Phasic and Inspiratory Tonic motor units in OSA subjects and their peak discharge rates are also altered. Single motor unit action potentials in OSA subjects showed an increased area. This suggests the presence of neurogenic changes and may provide a pathophysiological explanation for the increased multiunit electromyographic activity reported in OSA subjects during wakefulness.
Books on the topic "Time and Frequency Plot (TAFPLOT)"
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Mauldin, Erin Stewart. Accelerating Change. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780190865177.003.0005.
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Emancipation proved to be a far-reaching ecological event. Whereas the ecological regime of slavery had reinforced extensive land-use practices, the end of slavery weakened them. Freedpeople dedicated less time to erosion control and ditching and used contract negotiations and sharecropping arrangements to avoid working in a centrally directed gang. Understandably, freedpeople preferred to direct their own labor on an individual plot of land. The eventual proliferation of share-based or tenant contracts encouraged the physical reorganization of plantations. The combination of these two progressive alterations to labor relations tragically undermined African Americans’ efforts to achieve economic independence by tightening natural limits on cotton production and reducing blacks’ access to the South’s internal provisioning economy. The cessation, or even reduced frequency, of land maintenance on farms exacerbated erosion, flooding, and crops’ susceptibility to drought.
Book chapters on the topic "Time and Frequency Plot (TAFPLOT)"
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Saraswat, Monika, A. K. Wadhwani, and Sulochana Wadhwani. "Non-invasive Estimation of HRV Performance for Diabetes Mellitus with Cardiac Disorder on the Basis of Time-Frequency and Poincare Plot Analysis." In Intelligent Computing Applications for Sustainable Real-World Systems, 454–66. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-44758-8_42.
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Elsner, James B., and Thomas H. Jagger. "Frequency Models." In Hurricane Climatology. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199827633.003.0011.
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Here in Part II, we focus on statistical models for understanding and predicting hurricane climate. This chapter shows you how to model hurricane occurrence. This is done using the annual count of hurricanes making landfall in the United States. We also consider the occurrence of hurricanes across the basin and by origin. We begin with exploratory analysis and then show you how to model counts with Poisson regression. Issues of model fit, interpretation, and prediction are considered in turn. The topic of how to assess forecast skill is examined including how to perform cross-validation. Alternatives to the Poisson regression model are considered. Logistic regression and receiver operating characteristics (ROCS) are also covered. You use the data set US.txt which contains a list of tropical cyclone counts by year (see Chapter 2). The counts indicate the number of hurricanes hitting in the United States (excluding Hawaii). Input the data, save them as a data frame object, and print out the first six lines by typing . . . > H = read.table("US.txt", header=TRUE) > head(H) . . . The columns include year Year, number of U.S. hurricanes All, number of major U.S. hurricanes MUS, number of U.S. Gulf coast hurricanes G, number of Florida hurricanes FL, and number of East coast hurricanes E. Save the total number of years in the record as n and the average number hurricanes per year as rate. . . . > n = length(H$Year); rate = mean(H$All) > n; rate [1] 160 [1] 1.69 . . . The average number of U.S. hurricanes is 1.69 per year over these 160 years. First plot a time series and a distribution of the annual counts. Together, the two plots provide a nice summary of the information in your data relevant to any modeling effort. . . . > par(las=1) > layout(matrix(c(1, 2), 1, 2, byrow=TRUE), + widths=c(3/5, 2/5)) > plot(H$Year, H$All, type="h", xlab="Year", + ylab="Hurricane Count") > grid() > mtext("a", side=3, line=1, adj=0, cex=1.1) > barplot(table(H$All), xlab="Hurricane Count", + ylab="Number of Years", main="") > mtext("b", side=3, line=1, adj=0, cex=1.1) . . . The layout function divides the plot page into rows and columns as specified in the matrix function (first argument).
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Martinho Simões, José A., and Manuel Minas da Piedade. "Kinetics in Solution." In Molecular Energetics. Oxford University Press, 2008. http://dx.doi.org/10.1093/oso/9780195133196.003.0019.
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The main equations used to extract thermochemical data from rate constants of reactions in solution were presented in section 3.2. Here, we illustrate the application of those equations with several examples quoted from the literature. First, however, recall that the rate constant for any elementary reaction in solution, defined in terms of concentrations, is related to the activation parameters through equations 15.1 or 15.2. Equation 15.1 yields the enthalpy and the entropy of activation respectively from the slope and the intercept of a ln(k/T) versus 1/T plot (an Eyring plot). Equation 15.2 leads to the Arrhenius activation energy and the frequency factor, respectively, from the slope and the intercept of a ln k versus 1/T plot (an Arrhenius plot). All the parameters refer to the mean temperature of the plot, and Δ‡Ho is related to Ea by equation 15.3. Finally, recall that if the activation parameters are available for the forward (subscript 1) and the reverse (subscript −1) reaction, the enthalpy of this reaction is calculated by equation 15.4. In the preceding chapter on equilibrium in solution, it was pointed out that any analytical method suitable for determining equilibrium compositions of a reaction mixture at several temperatures can be used to obtain the enthalpy and entropy of that reaction. A similar statement can be made here: Any analytical method suitable for monitoring concentration changes with time at several temperatures can be used to derive the activation parameters of a reaction. Therefore, the analytical techniques used in equilibrium experiments are also applied in nonequilibrium (kinetics) studies. However, in this case, the choice of the analytical method will have an additional and important restriction, for it must consider the reaction rate. An instrumental technique suitable for determining the concentration of a given species under equilibrium conditions may be inappropriate for determining a fast concentration change of the same species.
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Jana, Tamonash, Anirban Mitra, and Prasanta Sahoo. "Static and Dynamic Analysis of Deformable Fractal Surface in Contact With Rigid Flat." In Handbook of Research on Advancements in Manufacturing, Materials, and Mechanical Engineering, 141–74. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-4939-1.ch007.
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The chapter consists of static and dynamic analyses of a fractal rough surface in contact with a rigid flat. The fractal surface is constructed using modified Weierstrass-Mandelbrot function. A rigid flat surface touches the topmost point of the rough surface, which moves towards the rough surface and deforms it. Different contact parameters (e.g., contact force, contact area, contact stress, etc. for varying fractal and material properties are obtained through finite element based static analysis. A parameter denoting the degree of nonlinearity of the contact system is extracted from the force-displacement plot of the surface. This parameter is utilized to explain the dynamic behaviour of the fractal surface which vibrates under the influence of the externally excited rigid flat surface. The dynamic analysis of the contact system is carried out by modelling the contact interface as a single degree of freedom (SDOF) spring-mass-damper system. The dynamic behavior of the system is investigated in terms of frequency response curves, time-displacement plots, and phase plots.
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Sivachidambaram, P., Raghuraman Srinivasan, and Venkatraman Ramamoorthy. "Pulsed TIG Welding of Al–SiC Composite: Welding Parameter Optimization." In Encyclopedia of Aluminum and Its Alloys. Boca Raton: CRC Press, 2019. http://dx.doi.org/10.1201/9781351045636-140000275.
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Pulse on time, pulse frequency, peak current, and base current are the important parameters to be optimized in pulsed current tungsten inert gas (PCTIG) welding of Al–SiC metal matrix composite. Experiments were designed and conducted using the L9 orthogonal array technique. The regression equation was developed using Design Expert® statistical software package to predict the weld center’s micro hardness, yield strength, ultimate strength, elongation (%), bending load, weld depth, weld width, cooling rate, and peak temperature near the weld zone of Al-8% SiC composite, welded using PCTIG welding. Correlation coefficient shows 0.9 for all the mechanical properties. This showed that the regression equation and the mathematical model developed were adequate. Analysis of contour plot, interaction effect, signal-to-noise ratio, and mean response were developed, the influence of each pulsed current parameter was evaluated at each level, and the percentage of influence was calculated by using pulsed current parameters. Ultimate tensile strength and bending load values depend on the microstructure. When the cooling rate is higher, fine microstructures are observed due to grain refinement; higher tensile strength and bending load are also observed. Due to the decreased cooling rate, coarse microstructures are observed, which result in poor tensile strength and bending load. PCTIG welding parameters are responsible for the change in the cooling rate of the weld zone. The optimization of the PCTIG welding parameters shows that the peak current and base current should be 160 and 60 A, respectively. Pulse on time is recommended to be 50%–55% and pulse frequency to be 5 Hz.
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Elsner, James B., and Thomas H. Jagger. "Impact Models." In Hurricane Climatology. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199827633.003.0017.
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In this chapter, we show some broader applications of our models and methods. We focus on impact models. Hurricanes are capable of generating large financial losses. We begin with a model that estimates extreme losses conditional on climate covariates. We then describe a method for quantifying the relative change in potential losses over the decades. Financial losses from hurricanes are to some extent directly related to fluctuations in climate. Environmental factors influence the frequency and intensity of hurricanes at the coast as detailed throughout this book (see for example Chapters 7 and 8). So, it is not surprising that these same environmental signals appear in estimates of losses. Here loss is the economic damage associated with a hurricane’s direct impact. A normalization procedure adjusts the loss estimate from a past hurricane to what it would be if the same cyclone struck in a recent year by accounting for inflation and changes in wealth and population over the intervening time, plus a factor to account for changes in the number of housing units exceeding population growth. The method produces loss estimates that can be compared over time (Pielke et al. 2008). Here you focus on losses exceeding one billion ($ U.S.) that have been adjusted to 2005. The loss data are available in Losses.txt in JAGS format (see Chapter 9). Input the data by typing . . . > source("Losses.txt"). . . The log-transformed loss amounts are in the column labeled ‘y’. The annual number of loss events are in the column labeled ‘L’. The data cover the period 1900–2007. More details about these data are given in Jagger et al. (2011). You begin by plotting a time series of the number of losses and a histogram of total loss per event. . . . > layout(matrix(c(1, 2), 1, 2, byrow=TRUE), + widths=c(3/5, 2/5)) > plot(1900:2007, L, type="h", xlab="Year", + ylab="Number of Loss Events") > grid() > mtext("a", side=3, line=1, adj=0, cex=1.1) > hist(y, xlab="Loss Amount ($ log)", + ylab="Frequency", main="") > mtext("b", side=3, line=1, adj=0, cex=1.1) . . .
Conference papers on the topic "Time and Frequency Plot (TAFPLOT)"
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Jianguo Yang and Wanqing Song. "Extracting noise using time-frequency profile plot." In 2010 International Conference on Mechanic Automation and Control Engineering (MACE). IEEE, 2010. http://dx.doi.org/10.1109/mace.2010.5536679.
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Mesa, F., and L. M. Marin. "A CABRI plot generator to describe frequency and time domain properties of SOPTD responses." In EUROCON 2005 - The International Conference on "Computer as a Tool". IEEE, 2005. http://dx.doi.org/10.1109/eurcon.2005.1629915.
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Zee, Bernice, Wen Qiu, Fangjie Foo, Brian Lai, Jim Vickers, and David Tien. "Improved Phase Data Acquisition for Thermal Emissions Analysis of 2.5D IC." In ISTFA 2018. ASM International, 2018. http://dx.doi.org/10.31399/asm.cp.istfa2018p0017.
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Abstract Lock-in thermography (LIT) phase data is used to generate phase shift versus applied lock-in frequency plots to estimate defect depth in semiconductor packages. Typically, samples need to be tested for an extended time to ensure data consistency. Furthermore, determining the specific point on the thermal emission site to collect data from can be challenging, especially if it is large and dispersive. This paper describes how the use of new computational algorithms along with streamlined and automated workflows, such as self-adjusting thermal emission site positioning and phase measurement auto-stop, can result in improvements to data repeatability and accuracy as well as faster time to results. The new software is applied to generate the empirical phase shift versus applied lock-in frequency plot using 2.5D IC devices with known defect location. Subsequently, experimental phase shift data from reject 2.5D IC devices with unknown defect locations are obtained and compared against the empirical phase shift plot. The defect Z-depth of these devices are determined by comparing where the experimental phase shift data points lies with respect to empirical phase shift plot and validated with physical failure analysis (PFA).
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Roberts, Thomas C. H., and Patrick J. Cunningham. "Fuel Cell Frequency Response Function Modeling for Control Applications." In ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33178.
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This paper provides the framework for first-order transfer function modeling of a fuel cell for controls use. It is shown that under specific conditions a fuel cell can be modeled as a first-order system. With a first order model, it is possible to determine how the fuel cell responds dynamically on a systems level before incorporating it into a larger more complex system. Current data sheets for fuel cells provide limited information of the output of the fuel cell, and a polarization curve based on static operation. This is vital information, but gives no insight into how the fuel cell responds under dynamic conditions. Dynamic responses are important when incorporating fuel cells as a power source in larger systems, such as automobiles, as loads and conditions are constantly changing. The modeling technique used in this research is the frequency response function. In this approach an experimental frequency response, or Bode plot, is computed from a frequency rich input signal and corresponding output signal. Here the controlled input is the Hydrogen flow and the output is the fuel cell voltage. During these tests, the fuel cell was connected to a constant resistance load. Using the frequency response function approach, a family of first-order transfer function models was created for a fuel cell at different operating temperatures and reactant relative humidity. These models are validated through comparison to experimental step responses. From this family of models the variations in the first-order model parameters of static gain and time constant are quantified. Static gain varied from 0.675 to 0.961 and the time constant ranged between 4.5 seconds and 10.5 seconds.
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Lu, Ping, Y. Kevin Chou, and Raymond G. Thompson. "Short-Time Fourier Transform Method in AE Signal Analysis for Diamond Coating Failure Monitoring in Machining Applications." In ASME 2010 International Manufacturing Science and Engineering Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/msec2010-34305.
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Coating failures due to delaminations are the primary life-limiting criteria of diamond-coated tools in machining. Process monitoring to capture coating failures is thus desired to prevent from poor part quality and possible production disruption. Following previous studies of AE signal analysis for diamond coating failure monitoring in machining applications, this research applied a short-time Fourier transformation (STFT) method to capture the coating failure transition during cutting. The method uses sub-divided signal segments, in a continuous manner, for the fast Fourier transform (FFT) analysis and computes the amplitude ratio of high vs. low frequencies as a function of cutting time during a cutting pass. The results show that during the coating failure pass, a clear sharp increase of amplitude ratio (value change over one) of high/low frequency occurs along the cutting time. On the other hand, the amplitude ratio only exhibits a certain low range fluctuations in other passes, e.g., initial cutting and prior to failure passes. Thus, it can be suggested that the applied STFT method has a potential for diamond coating failure monitoring. However, for coating failure associated with a smaller tool wear (less than 0.8 mm flank wear-land width), the amplitude ratio plot from the STFT analysis may not clearly show the failure transition.
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Cohn, Marvin J., Fatma G. Faham, and Dipak Patel. "Frequency Distribution Curves for Main Steam Piping Multiaxial Stresses." In ASME 2014 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/pvp2014-28471.
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A high energy piping (HEP) asset integrity management program is important for the safety of plant personnel and reliability of the generating unit. HEP weldment failures have resulted in serious injuries, fatalities, extensive damage of components, and significant lost generation. The main steam (MS) piping system is one of the most critical HEP systems. Creep damage assessment in MS piping systems should include the evaluation of multiaxial stresses associated with field conditions and significant anomalies, such as malfunctioning supports and significant displacement interferences. This paper presents empirical data illustrating that lead-the-fleet girth welds of MS piping systems have creep failures which can be successfully ranked by a multiaxial stress parameter, such as maximum principal stress. Both the as-found elastic (initial) stress and inelastic (redistributed) stress at the piping outside diameter surface are evaluated for the base metal of three MS piping systems. Frequency distribution curves are then developed for the initial and redistributed piping stresses. The frequency distribution curves are subsequently included on a Larson Miller Parameter (LMP) plot for the applicable material, revealing the few critical (lead-the-fleet) girth welds selected for nondestructive examination (NDE). By including an evaluation of significant field anomalies, multiaxial operating stress on the outside surface, and weldment performance, it is shown that there is a good correlation of calculated creep stress versus the operating time of observed creep damage. This process also reveals the large number of MS piping girth welds that have insufficient applied stress to have substantial creep damage within the expected unit life time (assuming no major fabrication defects). API 579 recommends an effective stress to compute the creep rupture life using the LMP. This constitutive stress equation includes a combination of the maximum principal, von Mises, and hydrostatic stresses. Considering the stresses in these three MS piping systems, this paper reveals that when the axial and hoop stresses are nearly the same values, the API 579 effective stress may be 10% greater than the maximum principal stress. However, the maximum principal stresses are greater than the API 579 effective stresses at the maximum stress locations in the three MS piping systems, because the axial stresses are significantly greater than the hoop stresses. This study also provides a comparison of the results of a conventional American Society of Mechanical Engineers (ASME) B31.1 Code as-designed sustained stress analysis versus the redistributed maximum principal stresses for a complete set of MS piping system nodes. A comparison of Code-sustained load versus redistributed maximum principal stress results are illustrated on frequency distribution curves.
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van ’t Veer, R., and M. Gachet. "Dynamic Positioning: Early Design, Capability and Offsets—A Novel Approach." In ASME 2011 30th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2011. http://dx.doi.org/10.1115/omae2011-49354.
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Many vessels use a Dynamic Positioning (DP) system that automatically controls vessel position and heading with its own propulsion system. The limiting environment in which a vessel can maintain heading and position under DP operation is typically shown in a capability plot. Capability is usually evaluated assuming constant environmental forces — the static DP approach. In this paper we discuss the methodology of how such a capability assessment can be made early in the vessel design stage. The insights obtained in the heading and position variability over time, and the effects of the environmental forces varying with time can be assessed through model tests and time domain simulations: the dynamic DP approach. This implies that the DP system characteristics are modeled. In a numerical approach, the time variable wind load and low-frequency drift forces are included in the assessment. This paper presents a novel approach on how static DP capability calculations can be corrected to account for the time variable wind and wave drift forces. This leads to a DP capability plot that provides a more realistic insight in the actual DP capability of the vessel in the dynamic environment.
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Lee, Young S., Gae¨tan Kerschen, Alexander F. Vakakis, Panagiotis Panagopoulos, Lawrence A. Bergman, and D. Michael McFarland. "Surprisingly Complicated Dynamics of a Single-Degree-of-Freedom Linear Oscillator Coupled to a Nonlinear Attachment." In ASME 2005 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/detc2005-84688.
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We study the dynamics of a two-degree-of-freedom nonlinear system consisting of a linear oscillator with an essentially nonlinear attachment. For the undamped system, we perform a numerical study based on non-smooth temporal transformations to determine its periodic solutions in a frequency-energy plot. It turns out that there is a sequence of periodic solutions bifurcating from the main backbone curve of the plot. We then study analytically the periodic orbits of the undamped system using the complexification / averaging technique in order to determine the frequency contents of the various branches of solutions, and to understand the types of oscillation performed by the system at the different regimes of the motion. The transient responses of the weakly damped system are then examined, and numerical wavelet transforms are used to study the time evolutions of their harmonic components. We show that the structure of periodic orbits of the undamped system greatly influences the damped dynamics, as it causes complicated transitions between modes in the damped transient motion. In addition, there is the possibility of strong passive energy transfer from the linear oscillator to the nonlinear attachment if certain periodic orbits of the undamped dynamics are excited by the initial conditions.
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Liang, J. W., and B. F. Feeny. "Wavelet Analysis of Stick-Slip in an Oscillator With Dry Friction." In ASME 1995 Design Engineering Technical Conferences collocated with the ASME 1995 15th International Computers in Engineering Conference and the ASME 1995 9th Annual Engineering Database Symposium. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/detc1995-0352.
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Abstract The dynamic behavior of the transition between slipping and sticking motions of a mass-spring system with dry friction is studied numerically and experimentally. Three mathematical models of dry friction are incorporated in the forced oscillator’s equation of motion. The wavelet transform is used to analyze response signals for both high and low frequency contents. For the simulated dynamical response, the wavelet transform can efficiently depict the transition characteristics in the time/frequency domain. The signatures observed in wavelet contour plot are compared to experimental results to evaluate the mathematical friction models. The wavelet transform can also be used to detect the dynamics of the sensor. The low-frequency experimental friction behavior is somewhat like the Coulomb friction model and its smooth version.
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Fong, Jeffrey T., N. Alan Heckert, James J. Filliben, and Marvin J. Cohn. "Uncertainty in Multi-Scale Creep Rupture Life Modeling and a New Approach to Estimating Frequency of In-Service Inspection of Components at Elevated Temperatures." In ASME 2018 Symposium on Elevated Temperature Application of Materials for Fossil, Nuclear, and Petrochemical Industries. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/etam2018-6711.
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Uncertainty in modeling the creep rupture life of a full-scale component using experimental data at microscopic (Level 1), specimen (Level 2), and full-size (Level 3) scales, is addressed by applying statistical theory of prediction intervals, and that of tolerance intervals based on the concept of coverage, p. Using a nonlinear least squares fit algorithm and the physical assumption that the one-sided Lower Tolerance Limit ( LTL ), at 95 % confidence level, of the creep rupture life, i.e., the minimum time-to-failure, minTf, of a full-scale component, cannot be negative as the lack or “Failure” of coverage ( Fp ), defined as 1 - p, approaches zero, we develop a new creep rupture life model, where the minimum time-to-failure, minTf, at extremely low “Failure” of coverage, Fp, can be estimated. Since the concept of coverage is closely related to that of an inspection strategy, and if one assumes that the predominent cause of failure of a full-size component is due to the “Failure” of inspection or coverage, it is reasonable to equate the quantity, Fp, to a Failure Probability, FP, thereby leading to a new approach of estimating the frequency of in-service inspection of a full-size component. To illustrate this approach, we include a numerical example using the published creep rupture time data of an API 579-1/ASME FFS-1 Grade 91 steel at 571.1 C (1060 F) (API-STD-530, 2007), and a linear least squares fit to generate the necessary uncertainties for ultimately performing a dynamic risk analysis, where a graphical plot of an estimate of risk with uncertainty vs. a predicted most likely date of a high consequence failure event due to creep rupture becomes available for a risk-informed inspection strategy associated with an energy-generation or chemical processing plant equipment.
Reports on the topic "Time and Frequency Plot (TAFPLOT)"
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Leis, Sherry. Vegetation community monitoring at Lincoln Boyhood National Memorial: 2011–2019. National Park Service, April 2021. http://dx.doi.org/10.36967/nrr-2284711.
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Lincoln Boyhood National Memorial celebrates the lives of the Lincoln family including the final resting place of Abraham’s mother, Nancy Hanks Lincoln. Lincoln’s childhood in Indiana was a formative time in the life our 16th president. When the Lincoln family arrived in Indiana, the property was covered in the oak-hickory forest type. They cleared land to create their homestead and farm. Later, designers of the memorial felt that it was important to restore woodlands to the site. The woodlands would help visitors visualize the challenges the Lincoln family faced in establishing and maintaining their homestead. Some stands of woodland may have remained, but significant restoration efforts included extensive tree planting. The Heartland Inventory and Monitoring Network began monitoring the woodland in 2011 with repeat visits every four years. These monitoring efforts provide a window into the composition and structure of the wood-lands. We measure both overstory trees and the ground flora within four permanently located plots. At these permanent plots, we record each species, foliar cover estimates of ground flora, diameter at breast height of midstory and overstory trees, and tree regeneration frequency (tree seedlings and saplings). The forest species composition was relatively consistent over the three monitoring events. Climatic conditions measured by the Palmer Drought Severity Index indicated mild to wet conditions over the monitoring record. Canopy closure continued to indicate a forest structure with a closed canopy. Large trees (>45 cm DBH) comprised the greatest amount of tree basal area. Sugar maple was observed to have the greatest basal area and density of the 23 tree species observed. The oaks characteristic of the early woodlands were present, but less dominant. Although one hickory species was present, it was in very low abundance. Of the 17 tree species recorded in the regeneration layer, three species were most abundant through time: sugar maple (Acer saccharum), red bud (Cercis canadensis), and ash (Fraxinus sp.). Ash recruitment seemed to increase over prior years and maple saplings transitioned to larger size classes. Ground flora diversity was similar through time, but alpha and gamma diversity were slightly greater in 2019. Percent cover by plant guild varied through time with native woody plants and forbs having the greatest abundance. Nonnative plants were also an important part of the ground flora composition. Common periwinkle (Vinca minor) and Japanese honeysuckle (Lonicera japonica) continued to be the most abundant nonnative species, but these two species were less abundant in 2019 than 2011. Unvegetated ground cover was high (mean = 95%) and increased by 17% since 2011. Bare ground increased from less than 1% in 2011 to 9% in 2019, but other ground cover elements were similar to prior years. In 2019, we quantified observer error by double sampling two plots within three of the monitoring sites. We found total pseudoturnover to be about 29% (i.e., 29% of the species records differed between observers due to observer error). This 29% pseudoturnover rate was almost 50% greater than our goal of 20% pseudoturnover. The majority of the error was attributed to observers overlooking species. Plot frame relocation error likely contributed as well but we were unable to separate it from overlooking error with our design.