scholarly journals Estimation of Probability Distributions of Geoacoustic Signal Characteristics

2021 ◽  
Vol 2096 (1) ◽  
pp. 012018
Author(s):  
M I Gapeev ◽  
Yu I Senkevich ◽  
O O Lukovenkova
Keyword(s):  
Probability Distributions ◽  
Maximum Amplitude ◽  
Kamchatka Peninsula ◽  
Test Site ◽  
Pulse Interval ◽  
Time Intervals ◽  
Pulse Envelope ◽  
Geoacoustic Emission ◽  
Emission Signal ◽  
Signal Characteristics

Abstract The paper presents an estimation of probability distributions of geoacoustic signal characteristics. The studied signals have a pulsed nature. The ones have been recording at the geodynamic test site of the IKIR FEB RAS (Kamchatka Peninsula) for more than 20 years. To estimate the distribution of characteristics, such time intervals were determined in which histograms of the distribution did not change. The following characteristics were chosen for the estimation: maximum amplitude, the position of pulse envelope maximum, duration, filling frequency, and pulse-to-pulse interval. The obtained estimates made it possible to develop an empirical model of the geoacoustic emission signal. The model can help to test new and existing algorithms for the processing and analysis of geoacoustic signals. The paper also shows that the formalization of the selected characteristics makes it possible to search for anomalies, including those associated with seismic events, by the characteristic variations.

scholarly journals Probability distributions of COVID-19 tweet posted trends use a nonhomogeneous Poisson process

2020 ◽  
Vol 1 (4) ◽  
pp. 229-238
Author(s):  
Devi Munandar ◽  
Sudradjat Supian ◽  
Subiyanto Subiyanto
Keyword(s):  
Social Media ◽  
Poisson Process ◽  
Exponential Distribution ◽  
Probability Distributions ◽  
Nonhomogeneous Poisson Process ◽  
Time Interval ◽  
Initial State ◽  
Time Intervals ◽  
Time Parameters ◽  
Parameter Values

The influence of social media in disseminating information, especially during the COVID-19 pandemic, can be observed with time interval, so that the probability of number of tweets discussed by netizens on social media can be observed. The nonhomogeneous Poisson process (NHPP) is a Poisson process dependent on time parameters and the exponential distribution having unequal parameter values and, independently of each other. The probability of no occurrence an event in the initial state is one and the probability of an event in initial state is zero. Using of non-homogeneous Poisson in this paper aims to predict and count the number of tweet posts with the keyword coronavirus, COVID-19 with set time intervals every day. Posting of tweets from one time each day to the next do not affect each other and the number of tweets is not the same. The dataset used in this study is crawling of COVID-19 tweets three times a day with duration of 20 minutes each crawled for 13 days or 39 time intervals. The result of this study obtained predictions and calculated for the probability of the number of tweets for the tendency of netizens to post on the situation of the COVID-19 pandemic.

scholarly journals Early Manifestations of Short-Term Precursors in Stress-Strain State Dynamics of Southern California

2021 ◽  
Vol 57 (4) ◽  
pp. 508-519
Author(s):  
V. G. Bondur ◽  
M. B. Gokhberg ◽  
I. A. Garagash ◽  
D. A. Alekseev
Keyword(s):  
Strain State ◽  
Southern California ◽  
Surrounding Medium ◽  
Maximum Amplitude ◽  
Theoretical Models ◽  
Time Intervals ◽  
Stress Strain ◽  
Epicentral Zone ◽  
Stress Strain State ◽  
Shear Strains

Abstract—The stress-strain state before the М = 7.1 Ridgecrest earthquake in Southern California is analyzed based on spatiotemporal distribution of shear strains calculated in the geomechanical model within local ~100 × 100 km crustal segments at a depth of 3–7 km. In the epicentral zone of the earthquake, starting from three years before the event, a successive series of the time intervals, up to the occurrence of the earthquake, when shear deformations are completely absent and rocks are farthest from ultimate strength—the so-called quiescence zones—are established. The spatial distribution of shear strains in the vicinity of the epicentral zone is analyzed during the quiescence intervals and subsequent bursts of maximum amplitude in the epicentral zone itself. The time intervals of the bursts are called excursions. The successive emergence of maxima in shear strain amplitudes in the epicentral zone and surrounding medium during the excursions corresponds to the situation of a swing when the entire preparation region of a future earthquake is rocking up to the moment of event. Consistency of the obtained results with the existing theoretical models of earthquake preparation is discussed.

scholarly journals Features of the Earth surface deformations in the Kamchatka peninsula and their relation to geoacoustic emission

Solid Earth ◽  
2014 ◽  
Vol 5 (2) ◽  
pp. 1293-1300 ◽  
Author(s):  
I. A. Larionov ◽  
Y. V. Marapulets ◽  
B. M. Shevtsov
Keyword(s):  
Michelson Interferometer ◽  
Kamchatka Peninsula ◽  
Frequency Range ◽  
Near Surface ◽  
Geoacoustic Emission ◽  
Direction Change ◽  
The Earth ◽  
Deformation Processes ◽  
Rock Deformations ◽  
Artificial Water

Abstract. The paper presents the results of investigations of deformation processes in the near-surface sedimentary rocks, which have been carried out in a seismically active region of the Kamchatka peninsula since 2007. The peculiarity of the experiments on registration of geodeformations is the application of a laser strainmeter–interferometer constructed according to the Michelson interferometer scheme. Besides rock deformations, geoacoustic emission in the frequency range from several hertz to the first tens of kilohertz is under investigation. Piezoceramic hydrophones installed in artificial water reservoirs are applied. It is shown that periods of primary rock compression and tension with a duration of up to several months are distinguished in the geodeformation process at the observation site. During the direction change in the deformations, when the geodeformation process rate grows, an increase in geoacoustic radiation is observed.

scholarly journals Urn models for regulated gene expression yield physically intuitive solutions for probability distributions of single-cell counts

2020 ◽  
Author(s):  
Krishna Choudhary ◽  
Atul Narang
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Single Cell ◽  
Hypergeometric Functions ◽  
Probability Distributions ◽  
Time Intervals ◽  
Probability Mass ◽  
Regulated Gene Expression ◽  
Short Time ◽  
Mass Functions

AbstractFitting the probability mass functions from analytical solutions of stochastic models of gene expression to the count distributions of mRNA and protein molecules in single cells can yield valuable insights into mechanisms of gene regulation. Solutions of chemical master equations are available for various kinetic schemes but, even for the models of regulation with a basic ON-OFF switch, they take complex forms with generating functions given as hypergeometric functions. Gene expression studies that have used these to fit the data have interpreted the parameters as burst size and frequency. However, this is consistent with the hypergeometric functions only if a gene stays active for short time intervals separated by relatively long intervals of inactivity. Physical insights into the probability mass functions are essential to ensure proper interpretations but are lacking for models of gene regulation. We fill this gap by developing urn models for regulated gene expression, which are of immense value to interpret probability distributions. Our model consists of a master urn, which represents the cytosol. We sample RNA polymerases and ribosomes from it and assign them to recipient urns of two or more colors, which represent time intervals with a homogeneous propensity for gene expression. Colors of the recipient urns represent sub-systems of the promoter states, and the assignments to urns of a specific color represent gene expression. We use elementary principles of discrete probability theory to derive the solutions for a range of kinetic models, including the Peccoud-Ycart model, the Shahrezaei-Swain model, and models with an arbitrary number of promoter states. For activated genes, we show that transcriptional lapses, which are events of gene inactivation for short time intervals separated by long active intervals, quantify the transcriptional dynamics better than bursts. Our approach reveals the physics underlying the solutions, which has important implications for single-cell data analysis.

First observation of multi-groundwater level responses to the strongest worldwide seismicity in Central Apennines (Central Italy).

2020 ◽  
Author(s):  
Marino Domenico Barberio ◽  
Francesca Gori ◽  
Maurizio Barbieri ◽  
Andrea Billi ◽  
Stefania Franchini ◽  
...  
Keyword(s):  
Water Level ◽  
Groundwater Level ◽  
Central Italy ◽  
Maximum Amplitude ◽  
Test Site ◽  
Observation Point ◽  
Seismic Events ◽  
Monitoring Site ◽  
Central Apennines ◽  
The World

<p>Earthquakes are the main natural processes which are able to cause the strongest crustal perturbations in the world. Seismic events change crustal stress, both static and dynamic, in the co-seismic and post-seismic phases. In particular, hydrogeological and hydrogeochemical responses include: changes in water level, temperature, chemical composition, stream flow, and gas geochemistry. Among these parameters water level changes is the most recorded signal because of its fast acquisition and easy instrumentation. Depending on the involved mechanism, groundwater level variation is different. In particular, previous studies have highlighted permanent and transient signals which are characterized by step and spike changes both upward and/or downward. Only few studies have reported groundwater level variations induced by earthquakes that are very far away from the observation point and they are known as “teleseism”. In order to investigate relationship between groundwater properties and seismic cycle, since July 2014 we installed a multiparameter probe in a 100 m deep groundwater well (PF60.3) in Central Apennines (Central Italy). This monitoring well is part of a more complex monitored test site developed for this aim and it has recorded already hydrogeochemical anomalies related to Amatrice-Norcia 2016-2017 seismic sequence. The occurrence of the strongest earthquakes in the world (≈M<sub>w</sub>>7.5), from the well probe installation (July 2014) until January 2020, has caused significant changes in groundwater level data. We analysed groundwater level behaviour in relationship to the occurrence of all 218 seismic events with M<sub>w</sub>>6.5. We identified 16 interactions, where groundwater level is characterized by an anomalous spike change both upward and/or downward. In particular, we observed a significant interaction between signals for all the strongest seismic events with a M<sub>w</sub>≥7.6, except for those happened in Papua Nuova Guinea and for those with ipocenter depth greater than 150 kilometers. We also found some interactions for less strong seismic events (6.5<M<sub>w</sub><7.5) but closer to the monitoring site. Among the observed correlations, 5 are characterized by a M<sub>w</sub> between 8 and 8.2 meanwhile the others have a M<sub>w</sub> between 6.5 and 7.9. The ipocenter depths of the considered 16 events are within 100 km, except two events that are deeper. We calculated the maximum amplitude of the perturbation and its duration. In this study we present our results with the main aim of expanding our understanding about perturbations due to distant earthquakes in the upper crust and in particular the relative fluid migration.</p>

scholarly journals The use of the empirical mode decomposition method to clean and restavration acoustic emission signal

2018 ◽  
Vol 62 ◽  
pp. 03008 ◽  
Author(s):  
Yury Senkevich
Keyword(s):  
Empirical Mode Decomposition ◽  
Comparative Evaluation ◽  
Decomposition Method ◽  
Low Frequency ◽  
Average Value ◽  
Geoacoustic Emission ◽  
Emission Signal ◽  
Mode Decomposition ◽  
Useful Signal ◽  
Empirical Mode Decomposition Method

The results of the study of the possibility of using the empirical mode decomposition method for cleaning geoacoustic emission signals from various types of noise are presented. It is shown that the application of the method allows to increase the ratio of the signal noise 3-6 dB depending on the ratio of signal dispersion and noise in the input signal. The examples demonstrate the ability to remove trends and harmonic interference, as well as the ability to highlight a useful signal when masking its powerful noise. A comparative evaluation of the method in relation to the low-frequency filtration is carried out. The limitation of the method applicability in the case of processing of pulse signals asymmetric with respect to its average value is indicated.

scholarly journals Features of the Earth surface deformations in Kamchatka peninsula and their relation with geoacoustic emission

2014 ◽  
Vol 6 (2) ◽  
pp. 2401-2422 ◽  
Author(s):  
I. A. Larionov ◽  
Yu. V. Marapulets ◽  
B. M. Shevtsov
Keyword(s):  
Michelson Interferometer ◽  
Kamchatka Peninsula ◽  
Frequency Range ◽  
Observation Site ◽  
Near Surface ◽  
Geoacoustic Emission ◽  
Direction Change ◽  
The Earth ◽  
Rock Deformations ◽  
Artificial Water

Abstract. The paper presents the results of investigations of deformation process in the near surface sedimentary rocks, which has been carried out in a seismically active region of Kamchatka peninsular since 2007. The peculiarity of the experiments on registration of geodeformations is the application of a laser strainmeter-interferometer constructed according to the Michelson interferometer scheme. Besides rock deformations, geoacoustic emission in the frequency range from several hertz to the first tens of kilohertz is under the investigation. Piezoceramic hydrophones installed in artificial water reservoirs are applied. It is shown that periods of primary rock compression and tension with the duration up to several months are distinguished in the geodeformation process at the observation site. During the direction change in the deformations, when geodeformation process rate grows, the increase of geoacoustic radiation is observed.

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