scholarly journals GEODYNAMICS

GEODYNAMICS ◽  
2021 ◽  
Vol 1(30)2021 (1(30)) ◽  
pp. 5-16
Author(s):  
Kornyliy Tretyak ◽  
◽  
Bogdan Palianytsia ◽  
Keyword(s):  
Time Series ◽  
Air Temperature ◽  
Practical Significance ◽  
Seasonal Temperature ◽  
Control Points ◽  
Technical Parameters ◽  
Vertical Displacements ◽  
Almost All ◽  
Gnss Time Series ◽  
Horizontal Displacements

The goal. Identify the relationship between seasonal temperature changes and vertical and horizontal displacements of GNSS control points based on data obtained by the automated monitoring system of the Dnipro HPP dam in the period from 2016 to 2020. Input data. The research used data of uninterrupted GNSS measurements obtained at 16 points of the Dnipro HPP dam from mid-2016 to mid-2020. Method. A specially developed software product analyzes the GNSS time series of measurements pre-processed by the GeoMoS system to determine the parameters of seasonal displacements and their relationship with seasonal changes in air temperature. The GNSS time series analysis. Based on the conducted research, the influence of environmental temperature has a decisive effect on the cyclicity of dam deformations. This applies to both horizontal and vertical displacements but in the absence of significant changes in the water level in the upper reservoir. Values of extreme displacements increase closer to the middle of the dam and decrease at the edges. This tendency is observed every year in the study period. According to the three-year GNSS dam monitoring, the amplitude of semi-annual horizontal oscillations of the control points relative to the dam axis is in the range of 15-18 mm. Almost all vectors of horizontal displacements are perpendicular to the axis of the arcuate dam. In the first half of the year, the vectors of horizontal displacements aim to widen the dam, and in the second half of the year - at compressing the dam. The analysis of the data represents that almost every year, extreme deviations, both horizontal and vertical, occur in February and August. Temperature extremes occur faster than excessive GNSS displacements. For the dam of the Dnipro HPP, the extreme horizontal displacements lag on average by 37 days, and the vertical ones - by 32 days from the extreme temperatures. The deformations of the dam are related to the concrete structure temperature, which changes with a certain delay relative to the air temperature. The magnitudes of extreme displacements and the epoch of their manifestation depend on the dam's design and its technical parameters. For each dam, these extreme displacements and the periods of their representation will be different. Accordingly, monitoring these displacements and their changes over time is one of the criteria for assessing the general condition of the dam. Scientific novelty and practical significance. The regularities of the connection between the change of temperature and the displacements of the GNSS points, revealed during the research, can be used for the further study of data processing and analysis of the hydraulic structures monitoring.

scholarly journals Identifying the sensitivity of GPS to non-tidal loadings at various time resolutions: examining vertical displacements from continental Eurasia

GPS Solutions ◽  
2021 ◽  
Vol 25 (3) ◽  
Author(s):  
Anna Klos ◽  
Henryk Dobslaw ◽  
Robert Dill ◽  
Janusz Bogusz
Keyword(s):  
Time Series ◽  
Seasonal Changes ◽  
System Modeling ◽  
Sea Level Changes ◽  
Observation Level ◽  
Earth System Modeling ◽  
Atmospheric Loading ◽  
Modeling Group ◽  
Vertical Displacements ◽  
Almost All

AbstractWe examine the sensitivity of the Global Positioning System (GPS) to non-tidal loading for a set of continental Eurasia permanent stations. We utilized daily vertical displacements available from the Nevada Geodetic Laboratory (NGL) at stations located at least 100 km away from the coast. Loading-induced predictions of displacements of earth’s crust are provided by the Earth-System-Modeling Group of the GFZ (ESMGFZ). We demonstrate that the hydrological loading, supported by barystatic sea-level changes to close the global mass budget (HYDL + SLEL), contributes to GPS displacements only in the seasonal band. Non-tidal atmospheric loading, supported by non-tidal oceanic loading (NTAL + NTOL), correlates positively with GPS displacements for almost all time resolutions, including non-seasonal changes from 2 days to 5 months, which are often considered as noise, intra-seasonal and seasonal changes with periods between 4 months and 1.4 years, and, also, inter-annual signals between 1.1 and 3.0 years. Correcting the GPS vertical displacements by NTAL leads to a reduction in the time series variances, evoking a whitening of the GPS stochastic character and a decrease in the standard deviation of noise. Both lead, on average, to an improvement in the uncertainty of the GPS vertical velocity by a factor of 2. To reduce its impact on the GPS displacement time series, we recommend that NTAL is applied at the observation level during the processing of GPS observations. HYDL might be corrected at the observation level or remain in the data and be applied at the stage of time series analysis.

scholarly journals Air temperature and precipitation variation trends of the Lancang river upstream from 1957 to 2011

2013 ◽  
Vol 17 (5) ◽  
pp. 1383-1388
Author(s):  
Ya-Nan Guo ◽  
Xiao-Hua Yang ◽  
Xiao-Juan Chen ◽  
Ying Mei ◽  
Chong-Li Di
Keyword(s):  
Time Series ◽  
Air Temperature ◽  
Practical Significance ◽  
Resources Allocation ◽  
Precipitation Time Series ◽  
Lancang River ◽  
Temperature And Precipitation ◽  
Precipitation Variation ◽  
Variation Trends ◽  
Kendall Method

Air temperature and precipitation variation trends of the upstream of Lancang river using the time series from 1957 to 2011 are evaluated. The Mann-Kendall method is applied to study the trend and climatic jump of the air temperature and precipitation time series. It shows that the temperature has an obvious uptrend with an increase of 0.023?C per year. The annual precipitation of the upstream of Lancang river is 954.96 mm without any change, however, the precipitation is gradually increased from upstream to downstream. This paper is significant for understanding the climate change over the years, and it has practical significance for water resources allocation and management in the future.

The Comparison of Land Subsidence between East and West Side of Bangkok, Thailand

2020 ◽  
Vol 17 (3) ◽  
pp. 1
Author(s):  
Angkana Pumpuang ◽  
Anuphao Aobpaet
Keyword(s):  
Time Series ◽  
Land Subsidence ◽  
Time Series Data ◽  
Series Data ◽  
Industrial Estates ◽  
Vertical Displacements ◽  
Land Deformation ◽  
Extensive Farming ◽  
Chao Phraya River ◽  
Set Up

The land deformation in line of sight (LOS) direction can be measured using time series InSAR. InSAR can successfully measure land subsidence based on LOS in many big cities, including the eastern and western regions of Bangkok which is separated by Chao Phraya River. There are differences in prosperity between both sides due to human activities, land use, and land cover. This study focuses on the land subsidence difference between the western and eastern regions of Bangkok and the most possible cause affecting the land subsidence rates. The Radarsat-2 single look complex (SLC) was used to set up the time series data for long term monitoring. To generate interferograms, StaMPS for Time Series InSAR processing was applied by using the PSI algorithm in DORIS software. It was found that the subsidence was more to the eastern regions of Bangkok where the vertical displacements were +0.461 millimetres and -0.919 millimetres on the western and the eastern side respectively. The districts of Nong Chok, Lat Krabang, and Khlong Samwa have the most extensive farming area in eastern Bangkok. Besides, there were also three major industrial estates located in eastern Bangkok like Lat Krabang, Anya Thani and Bang Chan Industrial Estate. By the assumption of water demand, there were forty-eight wells and three wells found in the eastern and western part respectively. The number of groundwater wells shows that eastern Bangkok has the demand for water over the west, and the pumping of groundwater is a significant factor that causes land subsidence in the area.Keywords: Subsidence, InSAR, Radarsat-2, Bangkok

scholarly journals Modelling spreading of an infection using time series by a novel family of models; fitting the time series of the confirmed cases of COVID-19 in China

2020 ◽  
Vol 9 (s1) ◽  
Author(s):  
Babak Jamshidi ◽  
Shahriar Jamshidi Zargaran ◽  
Mansour Rezaei
Keyword(s):  
Infectious Disease ◽  
Time Series ◽  
Communicable Disease ◽  
Time Series Models ◽  
Cumulative Number ◽  
The Novel ◽  
New Family ◽  
Two Samples ◽  
Almost All ◽  
Number Of Individuals

AbstractIntroductionTime series models are one of the frequently used methods to describe the pattern of spreading an epidemic.MethodsWe presented a new family of time series models able to represent the cumulative number of individuals that contracted an infectious disease from the start to the end of the first wave of spreading. This family is flexible enough to model the propagation of almost all infectious diseases. After a general discussion on competent time series to model the outbreak of a communicable disease, we introduced the new family through one of its examples.ResultsWe estimated the parameters of two samples of the novel family to model the spreading of COVID-19 in China.DiscussionOur model does not work well when the decreasing trend of the rate of growth is absent because it is the main presumption of the model. In addition, since the information on the initial days is of the utmost importance for this model, one of the challenges about this model is modifying it to get qualified to model datasets that lack the information on the first days.

scholarly journals An Analysis of Vertical Crustal Movements along the European Coast from Satellite Altimetry, Tide Gauge, GNSS and Radar Interferometry

2021 ◽  
Vol 13 (11) ◽  
pp. 2173
Author(s):  
Kamil Kowalczyk ◽  
Katarzyna Pajak ◽  
Beata Wieczorek ◽  
Bartosz Naumowicz
Keyword(s):  
Time Series ◽  
Satellite Altimetry ◽  
Tide Gauge ◽  
Measurement Techniques ◽  
Radar Interferometry ◽  
Vertical Movements ◽  
Persistent Scatterer ◽  
Gnss Time Series ◽  
Vertical Crustal Movements ◽  
European Coast

The main aim of the article was to analyse the actual accuracy of determining the vertical movements of the Earth’s crust (VMEC) based on time series made of four measurement techniques: satellite altimetry (SA), tide gauges (TG), fixed GNSS stations and radar interferometry. A relatively new issue is the use of the persistent scatterer InSAR (PSInSAR) time series to determine VMEC. To compare the PSInSAR results with GNSS, an innovative procedure was developed: the workflow of determining the value of VMEC velocities in GNSS stations based on InSAR data. In our article, we have compiled 110 interferograms for ascending satellites and 111 interferograms for descending satellites along the European coast for each of the selected 27 GNSS stations, which is over 5000 interferograms. This allowed us to create time series of unprecedented time, very similar to the time resolution of time series from GNSS stations. As a result, we found that the obtained accuracies of the VMEC determined from the PSInSAR are similar to those obtained from the GNSS time series. We have shown that the VMEC around GNSS stations determined by other techniques are not the same.

scholarly journals Adjoint-based direct data assimilation of GNSS time series for optimizing frictional parameters and predicting postseismic deformation following the 2003 Tokachi-oki earthquake

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Masayuki Kano ◽  
Shin’ichi Miyazaki ◽  
Yoichi Ishikawa ◽  
Kazuro Hirahara
Keyword(s):  
Time Series ◽  
Data Assimilation ◽  
Evaluation Method ◽  
Temporal Evolution ◽  
Recovery Process ◽  
Postseismic Deformation ◽  
Coseismic Slip ◽  
Megathrust Earthquakes ◽  
Spatio Temporal ◽  
Gnss Time Series

Abstract Postseismic Global Navigation Satellite System (GNSS) time series followed by megathrust earthquakes can be interpreted as a result of afterslip on the plate interface, especially in its early phase. Afterslip is a stress release process accumulated by adjacent coseismic slip and can be considered a recovery process for future events during earthquake cycles. Spatio-temporal evolution of afterslip often triggers subsequent earthquakes through stress perturbation. Therefore, it is important to quantitatively capture the spatio-temporal evolution of afterslip and related postseismic crustal deformation and to predict their future evolution with a physics-based simulation. We developed an adjoint data assimilation method, which directly assimilates GNSS time series into a physics-based model to optimize the frictional parameters that control the slip behavior on the fault. The developed method was validated with synthetic data. Through the optimization of frictional parameters, the spatial distributions of afterslip could roughly (but not in detail) be reproduced if the observation noise was included. The optimization of frictional parameters reproduced not only the postseismic displacements used for the assimilation, but also improved the prediction skill of the following time series. Then, we applied the developed method to the observed GNSS time series for the first 15 days following the 2003 Tokachi-oki earthquake. The frictional parameters in the afterslip regions were optimized to A–B ~ O(10 kPa), A ~ O(100 kPa), and L ~ O(10 mm). A large afterslip is inferred on the shallower side of the coseismic slip area. The optimized frictional parameters quantitatively predicted the postseismic GNSS time series for the following 15 days. These characteristics can also be detected if the simulation variables can be simultaneously optimized. The developed data assimilation method, which can be directly applied to GNSS time series following megathrust earthquakes, is an effective quantitative evaluation method for assessing risks of subsequent earthquakes and for monitoring the recovery process of megathrust earthquakes.

scholarly journals Teledermatology in Times of COVID-19 Confinement: Comparing Patients’ and Physicians’ Satisfaction by the Standardized Brest Teledermatology Questionnaire

Dermatology ◽  
2021 ◽  
pp. 1-6
Author(s):  
Joachim W. Fluhr ◽  
Annie Gueguen ◽  
Delphine Legoupil ◽  
Emilie Brenaut ◽  
Claire Abasq ◽  
...  
Keyword(s):  
Main Question ◽  
Chronic Patients ◽  
Dermatology Department ◽  
Global Satisfaction ◽  
Technical Parameters ◽  
Face To Face ◽  
Almost All ◽  
Outpatient Settings

The French government imposed the first COVID-19 pandemic lockdown from March 17 until May 11, 2020. Only emergency cases and teledermatology (TD) were allowed in outpatient settings. A standardized questionnaire was developed to compare the satisfaction level of patients and their treating physicians. Our main question was whether the patients would perceive TD as a valid alternative for direct physical face-to-face consultation. Eighty-two patients and their 4 treating dermatologists from one dermatology department participated in the study (43 females, 39 males) with a mean age of 46.6 years (SD ±23.9). The reason for TD was a chronic disease in the majority (87.8%), and mainly as a follow-up (96.3%). Regarding satisfaction, almost all categories rated around 9 on a 0–10 verbal analogue scale. The same level of global satisfaction could be seen between the patients and the physicians as well as for the quality of the patient-physician relation and whether all questions could be addressed during the TC. Physicians showed significantly higher scores than patients only for the category of “length” of the consultation. Gender, age, as well as distance between the clinic and home of the patient were not influencing factors for satisfaction. Regarding the technical parameters, the evaluation was mostly comparable for patients and physicians, but overall lower than the relational satisfaction parameters, especially for image quality. Patients were significantly more motivated to continue the TD after the lockdown than their treating dermatologists. We see an interest for implementing TD in specialized centers with chronic patients coming from remote places for regular follow-ups. TD cannot replace in-person patient-physician interaction, but was helpful during the lockdown. As a result, TD might become part of dermatology training to prepare for future lockdown situations.

Corporate Social Responsibility: Insights from Literature Review

2021 ◽  
Vol 25 (1) ◽  
pp. 26-35
Author(s):  
G.K. Deshmukh ◽  
Sanskrity Joseph ◽  
Asha Sahu
Keyword(s):  
Time Series ◽  
Corporate Social Responsibility ◽  
Social Responsibility ◽  
Time Series Analysis ◽  
Business Strategy ◽  
Net Worth ◽  
Series Analysis ◽  
Almost All ◽  
Corporate Social ◽  
The Impact

Corporate social Responsibility has become a buzz word in recent times. Its worldwide acceptance due to the social consciousness of enterprises coupled with legal orientation in developing countries like India has made it one of the most researched issue for researchers across continents. This paper is an attempt to review the development in the core concepts and theories which have been put forwarded by different researchers during the time period of 2010-2018. The paper undergoes a time series analysis for the selected period evaluating the evolution and impact assessment of CSR on core managerial concepts like marketing, finance and Human Resource management. The researchers after time series analysis have concluded that CSR is age long practice which has changed its orientation with the changes in objectives of business. It can be easily classified in three conceptual eras on the basis of its objectives. In the initial era it was a self-driven practice mainly influenced by the values of promoters of business. In the later stages it can be related with a business strategy of gaining goodwill. In the present era corporates have understood the value of societal obligation and it has again become a self-driven exercise. Further the impact of CSR has coupled with almost all functions of management which can be easily understood from the host of studies conducted during the selected period. The selected studies indicate that CSR has been instrumental in increasing net worth, customer satisfaction and employee retention.

scholarly journals Trends and regime shifts in climatic conditions and river runoff in Estonia during 1951–2015

2017 ◽  
Vol 8 (4) ◽  
pp. 963-976 ◽  
Author(s):  
Jaak Jaagus ◽  
Mait Sepp ◽  
Toomas Tamm ◽  
Arvo Järvet ◽  
Kiira Mõisja
Keyword(s):  
Time Series ◽  
Snow Cover ◽  
Atmospheric Circulation ◽  
Air Temperature ◽  
Large Scale ◽  
Regime Shifts ◽  
The Arctic ◽  
Dry Period ◽  
Snow Cover Duration ◽  
Large Scale Atmospheric Circulation

Abstract. Time series of monthly, seasonal and annual mean air temperature, precipitation, snow cover duration and specific runoff of rivers in Estonia are analysed for detecting of trends and regime shifts during 1951–2015. Trend analysis is realised using the Mann–Kendall test and regime shifts are detected with the Rodionov test (sequential t-test analysis of regime shifts). The results from Estonia are related to trends and regime shifts in time series of indices of large-scale atmospheric circulation. Annual mean air temperature has significantly increased at all 12 stations by 0.3–0.4 K decade−1. The warming trend was detected in all seasons but with the higher magnitude in spring and winter. Snow cover duration has decreased in Estonia by 3–4 days decade−1. Changes in precipitation are not clear and uniform due to their very high spatial and temporal variability. The most significant increase in precipitation was observed during the cold half-year, from November to March and also in June. A time series of specific runoff measured at 21 stations had significant seasonal changes during the study period. Winter values have increased by 0.4–0.9 L s−1 km−2 decade−1, while stronger changes are typical for western Estonia and weaker changes for eastern Estonia. At the same time, specific runoff in April and May have notably decreased indicating the shift of the runoff maximum to the earlier time, i.e. from April to March. Air temperature, precipitation, snow cover duration and specific runoff of rivers are highly correlated in winter determined by the large-scale atmospheric circulation. Correlation coefficients between the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) indices reflecting the intensity of westerlies, and the studied variables were 0.5–0.8. The main result of the analysis of regime shifts was the detection of coherent shifts for air temperature, snow cover duration and specific runoff in the late 1980s, mostly since the winter of 1988/1989, which are, in turn, synchronous with the shifts in winter circulation. For example, runoff abruptly increased in January, February and March but decreased in April. Regime shifts in annual specific runoff correspond to the alternation of wet and dry periods. A dry period started in 1964 or 1963, a wet period in 1978 and the next dry period at the beginning of the 21st century.

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