scholarly journals The approximation of an isolated epidemic process wave using a combination of exponents

2021 ◽  
Vol 57 (4) ◽  
pp. 391-400
Author(s):  
A. N. Avlas ◽  
A. K. Demenchuk ◽  
S. V. Lemeshevskii ◽  
E. K. Makarov
Keyword(s):  
Nonstationary Processes ◽  
Short Term ◽  
Infected People ◽  
Epidemic Process ◽  
Discrete Equations ◽  
Term Forecast ◽  
Long Term Forecasting ◽  
The Republic ◽  
Logistic Functions

The most commonly used methods for the medium- and long-term forecasting of epidemic processes are based on the classical SIR (susceptible – infected – recovered) model and its numerous modifications. In this approach, the dynamics of the epidemic is approximated using the solutions of differential or discrete equations. The forecasting methods based on the approximation of data by functions of a given class are usually focused on obtaining a short-term forecast. They are not used for the long-term forecasts of epidemic processes due to their insufficient efficiency for forecasting nonstationary processes. In this paper, we formulated a hypothesis that the primary waves of the COVID-19 pandemic, which took place in a number of European countries, including the Republic of Belarus, in the spring-summer of 2020 are isolated and therefore can be regarded as processes close to stationary. On the basis of this hypothesis, a method of approximating isolated epidemic process waves by means of generalized logistic functions with an increased number of exponents was proposed. The developed approach was applied to predict the number of infected people in the Republic of Belarus for the period until August 2020 based on data from the beginning of the epidemic until June 12, 2020.

scholarly journals COVID-19 Pandemic Development in Jordan—Short-Term and Long-Term Forecasting

Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 728
Author(s):  
Tareq Hussein ◽  
Mahmoud H. Hammad ◽  
Pak Lun Fung ◽  
Marwan Al-Kloub ◽  
Issam Odeh ◽  
...  
Keyword(s):  
Early Stage ◽  
Middle Eastern ◽  
Forecast Model ◽  
Third Wave ◽  
Short Term ◽  
Model Based ◽  
Model Merging ◽  
Term Forecast ◽  
Long Term Forecasting

In this study, we proposed three simple approaches to forecast COVID-19 reported cases in a Middle Eastern society (Jordan). The first approach was a short-term forecast (STF) model based on a linear forecast model using the previous days as a learning data-base for forecasting. The second approach was a long-term forecast (LTF) model based on a mathematical formula that best described the current pandemic situation in Jordan. Both approaches can be seen as complementary: the STF can cope with sudden daily changes in the pandemic whereas the LTF can be utilized to predict the upcoming waves’ occurrence and strength. As such, the third approach was a hybrid forecast (HF) model merging both the STF and the LTF models. The HF was shown to be an efficient forecast model with excellent accuracy. It is evident that the decision to enforce the curfew at an early stage followed by the planned lockdown has been effective in eliminating a serious wave in April 2020. Vaccination has been effective in combating COVID-19 by reducing infection rates. Based on the forecasting results, there is some possibility that Jordan may face a third wave of the pandemic during the Summer of 2021.

scholarly journals A survey of short-term and long-term stability of tube parameters in a mammography unit

2014 ◽  
Vol 29 (4) ◽  
pp. 321-325
Author(s):  
Jovica Praskalo ◽  
Jasna Davidovic ◽  
Biljana Kocic ◽  
Monika Zivkovic ◽  
Svetlana Pejovic
Keyword(s):  
Screening Program ◽  
Short Term ◽  
X Ray ◽  
Term Stability ◽  
Long Term Stability ◽  
Mammography Screening Program ◽  
The Republic ◽  
Set Up ◽  
The Given

In order to set up a successful mammography screening program in the Republic of Srpska, a Siemens Mammomat 1000 X-ray machine was selected for analysis as the said mammography system is widely used in clinical practice. The variations in tube parameters (specific air kerma, high-voltage accuracy and reproducibility, linearity between exposure and dose exposure time) were monitored over a five-year period, from 2008 to 2012. In addition, due to observed daily fluctuations for chosen parameters, a series of measurements were performed three times a day within a single-month period (mainly October 2012). The goal of such an experimental set up is to assess short-term and long-term stability of tube parameters in the given mammography unit and to make a comparison between them. The present paper shows how an early detection of significant parameter fluctuations can help eliminate irregularities and optimize the performance of mammography systems.

USE OF REGRESSION ANALYSIS IN FORECAST TASKS

2020 ◽  
pp. 22-27
Author(s):  
E.S. Lartseva ◽  
◽  
A.D. Kuznetsova
Keyword(s):  
Regression Analysis ◽  
Animal Population ◽  
Short Term ◽  
Statistical Estimates ◽  
Term Forecast ◽  
Applied Software ◽  
The Family ◽  
The Russian Federation

Based on official statistics on the number, of representatives of the family of non-ruminant cloven-hoofed animals (Artiodactyl) on the territory of the Russian Federation. Using the example of two species: domestic pigs and wild boars, the dynamics of the indicator for the long term is analyzed. Multidirectional trends were revealed for each species. Mathematical models of the dynamics of the livestock were obtained using the methods of regression analysis and applied software. Statistical estimates of the quality of animal population models were obtained. The short-term forecast for 2020 has been fulfilled.

Integration of geological and seismological data in earthquakes occurrence models for Italy: towards a unified model for different forecast perspectives

2019 ◽  
Vol 219 (3) ◽  
pp. 2148-2164
Author(s):  
A M Lombardi
Keyword(s):  
Aftershock Sequence ◽  
Earthquake Forecasting ◽  
Short Term ◽  
Background Rate ◽  
Etas Model ◽  
Term Forecast ◽  
Earthquake Predictability ◽  
Background Seismicity ◽  
Different Types

SUMMARY The operational earthquake forecasting (OEF) is a procedure aimed at informing communities on how seismic hazard changes with time. This can help them live with seismicity and mitigate risk of destructive earthquakes. A successful short-term prediction scheme is not yet produced, but the search for it should not be abandoned. This requires more research on seismogenetic processes and, specifically, inclusion of any information about earthquakes in models, to improve forecast of future events, at any spatio-temporal-magnitude scale. The short- and long-term forecast perspectives of earthquake occurrence followed, up to now, separate paths, involving different data and peculiar models. But actually they are not so different and have common features, being parts of the same physical process. Research on earthquake predictability can help to search for a common path in different forecast perspectives. This study aims to improve the modelling of long-term features of seismicity inside the epidemic type aftershock sequence (ETAS) model, largely used for short-term forecast and OEF procedures. Specifically, a more comprehensive estimation of background seismicity rate inside the ETAS model is attempted, by merging different types of data (seismological instrumental, historical, geological), such that information on faults and on long-term seismicity integrates instrumental data, on which the ETAS models are generally set up. The main finding is that long-term historical seismicity and geological fault data improve the pseudo-prospective forecasts of independent seismicity. The study is divided in three parts. The first consists in models formulation and parameter estimation on recent seismicity of Italy. Specifically, two versions of ETAS model are compared: a ‘standard’, previously published, formulation, only based on instrumental seismicity, and a new version, integrating different types of data for background seismicity estimation. Secondly, a pseudo-prospective test is performed on independent seismicity, both to test the reliability of formulated models and to compare them, in order to identify the best version. Finally, a prospective forecast is made, to point out differences and similarities in predicting future seismicity between two models. This study must be considered in the context of its limitations; anyway, it proves, beyond argument, the usefulness of a more sophisticated estimation of background rate, inside short-term modelling of earthquakes.

Variations revealed by INFREP Radio Network in correspondence of six earthquakes with MW greater than 5.0 occurred in the Balkan Peninsula and Adriatic Sea on 26 and 27 November, 2019

2020 ◽  
Author(s):  
Pier Francesco Biagi ◽  
Alexandra Nina ◽  
Anita Ermini ◽  
Giovanni Nico
Keyword(s):  
Adriatic Sea ◽  
Technological Development ◽  
Signal Amplitude ◽  
Balkan Peninsula ◽  
Ministry Of Education ◽  
Short Term ◽  
Before And After ◽  
The Republic ◽  
Education Science

<p>In this work we analyse variations in VLF/LF radio signal amplitudes recorded by the INFREP network in the period 16 November – 6 December, 2019 characterized by very intensive seismic activities in the Balkan peninsula, Crete, and Adriatic, Aegean and Black seas. Namely, 38 earthquakes with magnitude greater than 4.0 occurred in this area during the noticed period; the most intensive of them occurred on 26 and 27 November: three events in Albania (M<sub>w</sub>= 6.4, 5.3, 5.1), one in Crete (M<sub>w</sub>= 6), one in Bosnia and Herzegovina (M<sub>w</sub>= 5.4) and two in Adriatic sea (M<sub>w</sub>= 5.4, 5.3). We study both long- and short- term variations that are already recorded in earlier studies. The long-term variations relate to changes in the amplitude intensities in periods of several days and their existence is shown in many previous studies. The recent analyses also indicate short-term variations in signal amplitude noises started about several tents of minutes before the earthquake (Nina et al. 2020). In this work, we analyse different areas using INFREP network, which allow us to study local changes in the atmosphere. In order to examine possible precursors we considered longer time started and ended 10 days before and after the most intensive of the considered earthquakes, respectively.</p><p>This research is supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia, under the projects 176002 and III44002.</p><p>References</p><p>Nina, A., S. Pulinets, P. F. Biagi, G. Nico, S. T. Mitrović, M. Radovanović and L. Č. Popović. Science of the Total Environment 710 (2020) 136406</p>

scholarly journals Comparative Analysis of Executive Compensation in the Republic of Serbia and EU Countries

2019 ◽  
Vol 57 (2) ◽  
pp. 181-200
Author(s):  
Ivana Marinović Matović
Keyword(s):  
Comparative Analysis ◽  
Executive Compensation ◽  
High Capacity ◽  
Business Organization ◽  
Business Organizations ◽  
Short Term ◽  
Eu Countries ◽  
Strong Motivation ◽  
The Republic

AbstractExecutive compensations have a strong motivation role in contemporary business organizations. Adequate models of compensation enable attracting and retaining the high-capacity managers. This way, business organization conquers and maintains the competitive position in the context of globalization. It is necessary to align the executive compensation with the business organization’s strategy, which requires careful process of planning, done by the highest levels of management and ownership. The main objective of the paper is to explore and compare the structure and the level of executive compensation in the Republic of Serbia and EU countries. The paper focuses on executive compensation components, primarily long-term and short-term incentives, as well as sallary and benefits. A comparative analysis of executive compensation models was performed to explain the differences in the observed countries.The study found large and disproportionate differences in the executive compensation levels, conditioned mostly by the economic development of the observed economies.

scholarly journals ON THE POSSIBILITY OF LONG-TERM FORECASTING OF SEASONAL HYDROMETEOROLOGICAL PHENOMENA

2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Svetlana Morozova ◽  
Mariya Alimpieva
Keyword(s):  
Statistical Methods ◽  
European Part ◽  
The South ◽  
Term Forecast ◽  
Long Term Forecasting ◽  
Model Region ◽  
Three Phases

In present paper the expanding application possibility of physical-statistical methods in long-term forecast are viewed.A nonparametric discriminate analyzing model has been constructed on the South-East of EPR (European part ofRussia). The model is based on consideration of asynchronous bonds between the condition of circulating systems of theAtlantic-Eurasian hemisphere sector and the period of seasonal hydrotermeological events onset on South-East of ЕPR.This model allows distinguishing three cluster areas which associate with three phases of predicted event; commonly,only two cluster areas are distinguished. We would like to present results of predictions testing of training and controlsets. The conclusion of our model region appliance effectiveness is also represented in paper.

scholarly journals Financial Investment In The Republic Of Uzbekistan: Concept, Objectives, Accounting And Reporting

2011 ◽  
Vol 3 ◽  
Author(s):  
Saidjamol Mahmudov
Keyword(s):  
Financial Reporting ◽  
Short Term ◽  
Financial Investment ◽  
Financial Investments ◽  
The Republic

The concept of economic essence of financial investments has been defined. Recommendations on improving accounting of long-term and short-term securities have been worked out. Necessity of improving securities accounting, their reflection in the financial reporting, organization of accounting reporting in the part of financial investments accounting has been highlighted. Analytical accounting on the accounts of long-term investments accounting (0600) is conducted on the types of long-term investments and objects, in which these investments are made. Correspondingly compilation of analytical accounting must provide possibility of receiving data about long-term investments in the objects located in theterritoryofUzbekistanand outside it. Financial placements are accepted for accounting as the sum of actual costs for an investor.

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