SOME PROBLEMS WITH THE MATHEMATICAL MODELING OF ELECTROMAGNETIC VIBRATORS USED FOR TRANSPORTING BULK MATERIALS

Mathematical modeling with the original approach is used to study the dynamics of low-frequency electro-vibration machines while taking the technological load into account. Based on the mathematical analysis of differential equations describing the oscillatory motion of electromagnetic vibration exciters, the existing mathematical model has been corrected to describe the action of a semiconductor diode in the power circuits of single-cycle vibrators. Modeling nonlinear dynamic systems reveals the difficulties of obtaining the amplitude-frequency characteristics of the associated discrete change in the frequency of the driving force, as well as ways to overcome them

Influence of strong electromagnetic discharges on the dynamics of earthquakes time distribution in the Bishkek test area (Central Asia)

From 08/01/1983 to 28/03/1990, at the Bishkek ElectroMagnetic (EM) test site (Northern Tien Shan and Chu Val- ley area, Central Asia), strong currents, up to 2.5 kA, were released at a 4.5 km long electrical (grounded) dipole. This area is seismically active and a catalogue with about 14100 events from 1975 to 1996 has been analyzed. The seismic catalogue was divided into three parts: 1975-1983 first part with no EM experiments, 1983-1990 second part during EM experiments and 1988-1996 after experiments part. Qualitative and quantitative time series non- lin- ear analysis was applied to waiting times of earthquakes to the above three sub catalogue periods. The qualitative approach includes visual inspection of reconstructed phase space, Iterated Function Systems (IFS) and Recurrence Quantification Analysis (RQA). The quantitative approach followed correlation integral calculation of reconstruct- ed phase space of waiting time distribution, with noise reduction and surrogate testing methods. Moreover the Lem- pel-Ziv algorithmic complexity measure (LZC) was calculated. General dynamics of earthquakes' temporal distri- bution around the test area, reveals properties of low dimensional non linearity. Strong EM discharges lead to the increase in extent of regularity in earthquakes temporal distribution. After cessation of EM experiments the earth- quakes' temporal distribution becomes much more random than before experiments. To avoid non valid conclusions several tests were applied to our data set: differentiation of the time series was applied to check results not affected by non stationarity; the surrogate data approach was followed to reject the hypothesis that dynamics belongs to the colored noise type. Small earthquakes, below completeness threshold, were added to the analysis to check results robustness

Wine, Beer, Snuff, Medicine, and Loss of Diversity - Ethnobotanical travels in the Georgian Caucasus

Photo Essa

Socio-economic problems of return migration in Georgia

The book discusses the issues of migrants return and their reintegration against a background of the world’s financial and economic crisis, peculiarities of formation and functioning of the Georgian labour market. The concrete ways of economic reintegration and incentives for return migration expansion are determined. The book is designed for governmental and non-governmental structures, international organizations, scientific workers interested in the management of return migration. It is also designed for students and readers interested in territorial mobility of population.Introduction -- 1. Georgia’s external migration problems -- 2. Return Migration and Methodology for Its Study -- 3. Demographic structure and characteristics -- 4. Distribution of Returnees by Countries -- 5. Education Level and Qualification -- 6. Reasons for Emigration -- 7. Organization for Emigration -- 8. Returnees Health Conditions -- 9. Adaptation to Foreign Environment and Employment -- 10. Returnees Incomes Abroad and Remittances -- 11. Labour Migrants Links with Their Home Country -- 12. The Reasons for Return and Process for Return -- 13. Socio-Economic Reintegration Process -- 14. Returnees in Business -- 15. Ways of Returning to the Home Country for Our Compatriots Living Abroad -- Conclusion -- References