Search for p-mode Frequencies on Procyon A

Following the recent evidence for the presence of an excess of power around 1 mHz in the frequency spectrum of the Doppler shift measurements for Procyon (Martic et al., 1999), we searched for individual frequencies of p-modes from three independent observing runs (5, 10 and 15 nights). All observations (December 1997, November 1998, January 1999) were made with the ELODIE spectrograph on the 1.93 m telescope at Observatoire de Haute Provence. The individual peaks in cleaned power spectra of each time series in the interval of excess power are compared with the predicted p-mode frequencies from stellar models (Chaboyer et al., 1999) for Procyon A.

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Solar-Like Oscillations of Procyon A: Stellar Models and Time Series Simulations versus Observations

International Astronomical Union Colloquium ◽

10.1017/s0252921100058437 ◽

2000 ◽

Vol 176 ◽

pp. 461-462

Author(s):

C. Barban ◽

E. Michel ◽

M. Martic ◽

J. Schmitt ◽

J. C. Lebrun ◽

...

Keyword(s):

Time Series ◽

Power Spectrum ◽

Numerical Simulations ◽

Observational Data ◽

Theoretical Predictions ◽

Stellar Models ◽

Excess Power ◽

New Evidence

AbstractThe aim of this paper (further developed in Barban et al. 1999) is to present new evidence of the possible stellar origin of the observed excess power in the power spectrum of Procyon A presented in Martic et al. (1999) by comparing these observational data with theoretical predictions and numerical simulations.

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Analysis of power spectra of Doppler shift time series as a diagnostic tool for quiescent coronal loops

Astronomy and Astrophysics ◽

10.1051/0004-6361:20066069 ◽

2006 ◽

Vol 462 (1) ◽

pp. 331-340 ◽

Cited By ~ 9

Author(s):

Y. Taroyan ◽

R. Erdélyi ◽

J. G. Doyle ◽

S. J. Bradshaw

Keyword(s):

Time Series ◽

Diagnostic Tool ◽

Doppler Shift ◽

Power Spectra ◽

Coronal Loops

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Linear and Nonlinear Smooth Orthogonal Decomposition to Reconstruct Local Fatigue Dynamics: A Comparison

Volume 5: 22nd International Conference on Design Theory and Methodology; Special Conference on Mechanical Vibration and Noise ◽

10.1115/detc2010-28852 ◽

2010 ◽

Author(s):

David B. Segala ◽

David Chelidze ◽

Deanna Gates ◽

Jonathan Dingwell

Keyword(s):

Time Series ◽

Muscle Fatigue ◽

Power Spectra ◽

Dimensional Subspace ◽

Orthogonal Decomposition ◽

Muscle Injuries ◽

Data Set ◽

Individual Muscle ◽

The Individual ◽

Smooth Orthogonal Decomposition

Identifying physiological fatigue is important for the development of more robust training protocols, better energy supplements, and/or reduction of muscle injuries. Current fatigue measurement technologies are usually invasive and/or impractical, and may not be realizable in out of laboratory settings. A fatigue identification methodology that only uses motion kinematics measurements has a great potential for field applications. Phase space warping (PSW) features of motion kinematic time series analyzed through smooth orthogonal decomposition (SOD) have tracked individual muscle fatigue. In this paper, the performance of a standard SOD analysis is compared to its nonlinear extension using a new experimental data set. Ten healthy right-handed subjects (27 ± 2.8 years; 1.71 ± 0.10 m height; and 69.91 ± 18.26 kg body mass) perform a sawing motion by pushing a weighted handle back and forth until voluntary exhaustion. Three sets of joint kinematic angles are measured from the elbow, wrist and shoulder as well as surface Electromyography (EMG) from ten different muscle groups. A vector-valued feature time series is generated using PSW metrics estimated from movement kinematics. Dominant SOD coordinates of these features are extracted to track the individual muscle fatigue trends as indicated by mean and median frequencies of the corresponding EMG power spectra. Cross subject variability shows that considerably fewer nonlinear SOD coordinates are needed to track EMG-based fatigue markers, and that nonlinear SOD methodology captures fatigue dynamics in a lower-dimensional subspace than its linear counterpart.

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Spectral Pitch Similarity is a Predictor of Perceived Change in Sound- as Well as Note-Based Music

Music & Science ◽

10.1177/2059204319847351 ◽

2019 ◽

Vol 2 ◽

pp. 205920431984735

Author(s):

Roger T. Dean ◽

Andrew J. Milne ◽

Freya Bailes

Keyword(s):

Time Series ◽

Piano Music ◽

Individual Response ◽

Discrete Events ◽

Acoustic Intensity ◽

Spectral Parameters ◽

Cross Sectional ◽

Perceived Change ◽

Predictive Role ◽

The Individual

Spectral pitch similarity (SPS) is a measure of the similarity between spectra of any pair of sounds. It has proved powerful in predicting perceived stability and fit of notes and chords in various tonal and microtonal instrumental contexts, that is, with discrete tones whose spectra are harmonic or close to harmonic. Here we assess the possible contribution of SPS to listeners’ continuous perceptions of change in music with fewer discrete events and with noisy or profoundly inharmonic sounds, such as electroacoustic music. Previous studies have shown that time series of perception of change in a range of music can be reasonably represented by time series models, whose predictors comprise autoregression together with series representing acoustic intensity and, usually, the timbral parameter spectral flatness. Here, we study possible roles for SPS in such models of continuous perceptions of change in a range of both instrumental (note-based) and sound-based music (generally containing more noise and fewer discrete events). In the first analysis, perceived change in three pieces of electroacoustic and one of piano music is modeled, to assess the possible contribution of (de-noised) SPS in cooperation with acoustic intensity and spectral flatness series. In the second analysis, a broad range of nine pieces is studied in relation to the wider range of distinctive spectral predictors useful in previous perceptual work, together with intensity and SPS. The second analysis uses cross-sectional (mixed-effects) time series analysis to take advantage of all the individual response series in the dataset, and to assess the possible generality of a predictive role for SPS. SPS proves to be a useful feature, making a predictive contribution distinct from other spectral parameters. Because SPS is a psychoacoustic “bottom up” feature, it may have wide applicability across both the familiar and the unfamiliar in the music to which we are exposed.

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Benchmarking homogenization algorithms for monthly data

Climate of the Past ◽

10.5194/cp-8-89-2012 ◽

2012 ◽

Vol 8 (1) ◽

pp. 89-115 ◽

Cited By ~ 202

Author(s):

V. K. C. Venema ◽

O. Mestre ◽

E. Aguilar ◽

I. Auer ◽

J. A. Guijarro ◽

...

Keyword(s):

Time Series ◽

Performance Metrics ◽

Linear Trend ◽

Simulated Data ◽

Integrated Approach ◽

Global Network ◽

Temperature And Precipitation ◽

Skill Scores ◽

Simulated Network ◽

The Individual

Abstract. The COST (European Cooperation in Science and Technology) Action ES0601: advances in homogenization methods of climate series: an integrated approach (HOME) has executed a blind intercomparison and validation study for monthly homogenization algorithms. Time series of monthly temperature and precipitation were evaluated because of their importance for climate studies and because they represent two important types of statistics (additive and multiplicative). The algorithms were validated against a realistic benchmark dataset. The benchmark contains real inhomogeneous data as well as simulated data with inserted inhomogeneities. Random independent break-type inhomogeneities with normally distributed breakpoint sizes were added to the simulated datasets. To approximate real world conditions, breaks were introduced that occur simultaneously in multiple station series within a simulated network of station data. The simulated time series also contained outliers, missing data periods and local station trends. Further, a stochastic nonlinear global (network-wide) trend was added. Participants provided 25 separate homogenized contributions as part of the blind study. After the deadline at which details of the imposed inhomogeneities were revealed, 22 additional solutions were submitted. These homogenized datasets were assessed by a number of performance metrics including (i) the centered root mean square error relative to the true homogeneous value at various averaging scales, (ii) the error in linear trend estimates and (iii) traditional contingency skill scores. The metrics were computed both using the individual station series as well as the network average regional series. The performance of the contributions depends significantly on the error metric considered. Contingency scores by themselves are not very informative. Although relative homogenization algorithms typically improve the homogeneity of temperature data, only the best ones improve precipitation data. Training the users on homogenization software was found to be very important. Moreover, state-of-the-art relative homogenization algorithms developed to work with an inhomogeneous reference are shown to perform best. The study showed that automatic algorithms can perform as well as manual ones.

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Nonlinear analysis of the occurrence of hurricanes in the Gulf of Mexico and the Caribbean Sea

Nonlinear Processes in Geophysics ◽

10.5194/npg-25-291-2018 ◽

2018 ◽

Vol 25 (2) ◽

pp. 291-300 ◽

Cited By ~ 1

Author(s):

Berenice Rojo-Garibaldi ◽

David Alberto Salas-de-León ◽

María Adela Monreal-Gómez ◽

Norma Leticia Sánchez-Santillán ◽

David Salas-Monreal

Keyword(s):

Time Series ◽

Gulf Of Mexico ◽

Nonlinear Analysis ◽

Chaotic Behavior ◽

Caribbean Sea ◽

Historical Record ◽

Nonlinear Analyses ◽

The North ◽

The Caribbean ◽

The Individual

Abstract. Hurricanes are complex systems that carry large amounts of energy. Their impact often produces natural disasters involving the loss of human lives and materials, such as infrastructure, valued at billions of US dollars. However, not everything about hurricanes is negative, as hurricanes are the main source of rainwater for the regions where they develop. This study shows a nonlinear analysis of the time series of the occurrence of hurricanes in the Gulf of Mexico and the Caribbean Sea obtained from 1749 to 2012. The construction of the hurricane time series was carried out based on the hurricane database of the North Atlantic basin hurricane database (HURDAT) and the published historical information. The hurricane time series provides a unique historical record on information about ocean–atmosphere interactions. The Lyapunov exponent indicated that the system presented chaotic dynamics, and the spectral analysis and nonlinear analyses of the time series of the hurricanes showed chaotic edge behavior. One possible explanation for this chaotic edge is the individual chaotic behavior of hurricanes, either by category or individually regardless of their category and their behavior on a regular basis.

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An Experimental Study of the Forced Response of Pre- and Post-Critical Plates

Volume 3A: 15th Biennial Conference on Mechanical Vibration and Noise — Vibration of Nonlinear, Random, and Time-Varying Systems ◽

10.1115/detc1995-0310 ◽

1995 ◽

Author(s):

Kevin D. Murphy ◽

Lawrence N. Virgin ◽

Stephen A. Rizzi

Keyword(s):

Experimental Study ◽

Time Series ◽

Lyapunov Exponent ◽

Small Amplitude ◽

Narrow Band ◽

Power Spectra ◽

Forced Response ◽

Acoustic Excitation ◽

Rectangular Plates ◽

Auto Correlation

Abstract Experimental results are presented which characterize the dynamic response of homogeneous, fully clamped, rectangular plates to narrow band acoustic excitation and uniform thermal loads. Using time series, pseudo-phase projections, power spectra and auto-correlation functions, small amplitude vibrations are considered about both the pre- and post-critical states. These techniques are then employed to investigate the snap-through response. The results for snap-through suggest that the motion is temporally complex and a Lyapunov exponent calculation confirms that the motion is chaotic. Finally, a snap-through boundary is mapped in the (ω, SPL) parameter space separating the regions of snap-through and no snap-through.

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Determination of the complex frequencies for the normal modes below 1mHz after the 2010 Maule and 2011 Tohoku earthquakes

Annals of Geophysics ◽

10.4401/ag-6400 ◽

2014 ◽

Vol 56 (5) ◽

Author(s):

Hao Ding ◽

Wen-Bin Shen

Keyword(s):

Time Series ◽

Normal Modes ◽

Power Spectra ◽

Tohoku Earthquake ◽

Superconducting Gravimeter ◽

Width Ratio ◽

Maule Earthquake ◽

Attenuation Models ◽

First Time

Based upon SG (superconducting gravimeter) records, the autoregressive method proposed by Chao and Gilbert [1980] is used to determine the frequencies of the singlets of seven spheroidal modes (0S2, 2S1, 0S3, 0S4, 1S2, 0S0, and 3S1) and the degenerate frequencies of three toroidal modes (0T2, 0T3, and 0T4) below 1 mHz after two recent huge earthquakes, the 2010 Mw8.8 Maule earthquake and the 2011 Mw9.1 Tohoku earthquake. The corresponding quality factor Qs are also determined for those modes, of which the Qs of the five singlets of 1S2 and the five singlets (m=0, m=±2, and m=±3) of 0S4 are estimated for the first time using the SG observations. The singlet m=0 of 3S1 is clearly observed from the power spectra of the SG time series without using other special spectral analysis methods or special time series from pole station records. In addition, the splitting width ratio R of 3S1 is 0.99, and consequently we conclude that 3S1 is normally split. The frequencies and Qs of the modes below 1mHz may contribute to refining the 3D density and attenuation models of the Earth.

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Doppler Shift of Radio Signals Transmitted between Orbiting Satellites

Australian Journal of Physics ◽

10.1071/ph820155 ◽

1982 ◽

Vol 35 (2) ◽

pp. 155 ◽

Cited By ~ 1

Author(s):

PL Dyson ◽

JA Bennett

Keyword(s):

Electron Concentration ◽

Doppler Shift ◽

Rate Of Change ◽

Line Of Sight ◽

Concentration Gradients ◽

Mean Velocity ◽

Radio Signals ◽

The Mean ◽

The Moment ◽

The Individual

A general expression, applicable at VHF and above, is derived for the Doppler shift of radio signals transmitted between two satellites embedded in the ionosphere. The Doppler shift is made up of several contributions which depend on (a) the rate of change of the free space path between the satellites, (b) the components, perpendicular to the line of sight between the satellites, of both the mean velocity of the satellites and the electron concentration gradients, (c) the moment of the perpendicular electron concentration gradients and the deviations from the mean of the individual satellite perpendicular velocities, (d) the velocity components along the line of sight between the satellites, and the electron concentration values at each satellite, and (e) changes occurring in the ionosphere with time.

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Acute Promyelocytic Leukemia (APL): Seasonal Behavior in Colombia for the Period 2009-2019

Blood ◽

10.1182/blood-2020-143191 ◽

2020 ◽

Vol 136 (Supplement 1) ◽

pp. 38-39

Author(s):

Humberto Martínez Cordero ◽

Juan Ospina Idarraga ◽

Xiomara Castañeda Contreras ◽

Alejandro Rico Mendoza ◽

Henry Idrobo ◽

...

Keyword(s):

Time Series ◽

Acute Promyelocytic Leukemia ◽

Progressive Increase ◽

Promyelocytic Leukemia ◽

Early Mortality ◽

Main Diagnosis ◽

Cure Rate ◽

Seasonal Behavior ◽

Seasonal Indices ◽

The Individual

Background Acute promyelocytic leukemia (APL) is a malignant hematologic disease with a high cure rate, but unfortunately it produces several serious complications at the onset of the disease that explain the high early mortality. Based on clinical experience and the papers that precede this document, it has been observed that the incidence of this type of hematological cancer tends to increase at certain times of the year. The present study aims to determine the possible variations in the time intervals of the prevalence of promyelocytic leukemia in Colombia in the decade 2009 to 2019, in order to identify the behavior of the event, seasonality and cyclicality. Methods With data from the individual records of service provision (RIPS) of the official Colombian health system, the prevalence of APL in Colombia from 2009 to 2019 was identified. A filter was made by people attended, main diagnosis, C924 - promyelocytic leukemia acute, by year, semester and month. The analysis was performed with RStudio, R version 4.0.2 (2020-06-22); The fpp2 library was used, the analysis of the monthly and quarterly time series was carried out, the decomposition of the time series was carried out, trying through this process to evaluate the seasonal indices through additive and multiplicative types. Results During the entire period 2009 to 2019, 2,986 APL diagnoses were found throughout the national territory of Colombia. A progressive increase in prevalence was determined in the period studied (Graph 1). Cycles of increasing cases were observed every 10 months in the period 2009 to 2015 and in the cycle from 2016 to 2019 there was a prolongation of the cycle every 17 months, which strongly suggested that APL has cyclical behavior. Quarterly seasonality was identified by the multiplicative method with increases and decreases that behave in a similar way throughout the period studied (Graph 2). Conclusion APL is a highly curable disease that requires adequate support at the onset of the disease to avoid early mortality. The data from this study allow us to conclude that for the period 2009 to 2019 there is a seasonal behavior of this malignant hemopathy. The possibility of predicting during which months of the year the incidence of the disease will increase can serve to properly plan the health services in charge of treating this disease. Additional studies are required to determine what is the cause of the cyclical and seasonal behavior of this APL Disclosures Idrobo: Amgen:Honoraria, Speakers Bureau;Takeda:Honoraria, Speakers Bureau;Janssen:Honoraria, Speakers Bureau;Tecnofarma:Honoraria, Speakers Bureau;Abbvie:Honoraria, Speakers Bureau.

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