Explaining the density of post-communist interest group populations—resources, constituencies, and regime change

The article tests the energy–stability–area (ESA) model of interest group population density on a sample of different 2018 Czech, Hungarian, Polish and Slovenian energy, higher education and health care interest organisation populations. The unique context of recent simultaneous political, economic and in the cases of Czechia and Slovenia, national transitions present a hard test for population ecology theory. Besides the area (constituency size) and energy (resources, issue certainty) terms, the article brings the stability term back into the center of analysis. The stability term, that is, the effect of a profound change or shock to the polity is operationalised as Communist-era population densities. As all three policy domains are heavily state controlled and tightly regulated, the effect of neocorporatist interest intermediation is also tested. The article finds strong support for the energy and neocorporatism hypotheses and provides evidence for the effect of communist-era organisational population density on post-transition densities: The size of 2018 organisational populations is found to be dependent on pre-transition densities. The relationship is, however, not linear but curvilinear. Nevertheless, the analysis indicates that the effect of pre-transition population size is moderated by other environmental level factors.

ABOUT THE INFLUENCE OF VIBRATIONS OF THE CONVEYED LIQUID ON THE AREA OF STABILITY OF A CLOSED SYSTEM AUTOMATIC VEHICLE COURSE CONTROL

The existing publications that investigate vehicle course stability optimization were analyzed. A mathematical model, which describes the disturbed movement of a car with a tank, was compiled. This model allows to consider the liquid free surface oscillations and determine their effect on the car course stability during constant motion or emergency braking. There was described the main information regarding the car that was used to perform mathematical calculations. An algorithm was developed for deriving the characteristic equation for a complex system of differential equations describing dynamic changes in the movement parameters of a car, oscillations of partial layers of liquid in a tank and the operation of an electromagnetic drive of the control valve and an electronic PID controller for a two-circuit system for ensuring course stability. Based on the developed mathematical model, the influence of forced oscillations of the fluid on the stability area of the system built in the plane of variable parameters of the controller is investigated. It is shown that low-frequency oscillations of the free surface of a liquid lead to a significant reduction in the stability area, which indicates the need to consider such oscillations when solving problems of analysis and synthesis of this system. It was found that for a car with a tank, where low-frequency transverse oscillations of the liquid occur, which are accompanied by a redistribution of mass and disturb the movement, an increase of the speed unambiguously leads to a deterioration in directional stability. That enables exclusion of speed from the number of variable parameters and significantly simplify the problem being solved. The calculations for cases with different loading levels were performed. It was found out that the level of liquid in the tank, considering its relationship with the speed, has an ambiguous effect on the car course stability, and it is unacceptable to limit the research calculations to the case with 50 % load. Instead of this, it is necessary to find a line that bends from above the stability boundaries that correspond to many liquid levels. Keywords: fluid vibrations; exchange rate stability system; area of stability; tank; PID-controller; parameters.

Stabilizing and Robust Fractional PID Controller Synthesis for Uncertain First-Order plus Time-Delay Systems

In this paper, by using the noninteger P I λ D μ controllers, we conduct an investigation into the subject of robust stability area of time-delay interval process. Our method is based on setting up of the noninteger interval closed-loop characteristic equation using the inferior and superior bounds of uncertain parameters into several vertexes. We have combined the composition of the value set of vertex with the zero exclusion principle to analyse the stability of the uncertain process. A generalized version of the Hermite–Biehler theorem, applicable to fractional quasipolynomials, is exploited to determine the stability region of each vertex. The robust stability region of the noninteger regulator can be given by the crossing of the stability area of all the vertex characteristic noninteger quasipolynomials. By using the value set method and zero exclusion theory, the effectiveness of the stability region can be tested. Also, we propose a suitable procedure to determine the whole of stabilizing parameters for an interval process. An explicative example is given to point out the advantage and reliability of the approach.

The Stability Analyze of KM. Rejeki Baru Kharisma of Tarakan – Tanjung Selor Route

Ship stability that is not according to the IMO standard will make the ship capsize when operating. The purpose of this research is to determine the cause of the overturn in terms of the stability criteria of the ship. The method used is software of simulation. Stability analysis is carried out with the load case that occurs in the field when an accident occurs and the ideal loadcase according to PM 104 2017 standards about’s the transportation of operation. The results showed is cargo of goods placed on the roof top (loadcase 1) based on the criteria of Intact Stability; area of the stability arm curve at heeling 0° ~ 30° = 0.9417 m.deg, area 0° ~ 40° = 1,0200 m.deg, 30° ~ 40° = 0.0783 m.deg, GZ value at heeling 30° = 0.029 m, angle of occurrence of maximum GZ = 21.8°, and the initial GMt value = 0.135 m, the results stated that all did not meet the Intact Stability code A.749 criteria, while in it was obtained cargo of goods placed in the hull (loadcase 2) based on Intact Stability; area of the stability arm curve at heeling 0° ~ 30° = 4.5338 m.deg, area 0° ~ 40° = 7.1643 m.deg, area 30° ~ 40° = 2.6305 m.deg, GZ value at heeling 30° = 0.265 m, angle of occurrence of maximum GZ = 34.5°, and the initial GMt value = 0.621 m, the results stated that all met the Intact Stability code A.749 criteria

Stability area of a synchronous generator nonlinear model with multiparametric excitation controller

We take as the research object the well-known system of nonlinear differential and functional equations that describes a synchronous generator. PIDD2-control was carried out through the excitation block. Effective values of the steady state in relative units and the preliminary settings of suboptimal controllers were obtained earlier using a linearized model. Disturbing surges (spikes and slump) in bus voltages were modeled as line impedance changes. The system stabilization was studied at various surges values and controller parameters by means series of numerical experiments; the calculations were carried out by the methods of Runge-Kutta and Dorman-Prince. The main attention was paid to various transient types, both stabilizing and diverging, as well as a configuration of the stability region boundary in the controller parameters of and a surge magnitude; the paper presents the results for the proportional control parameter are as the most informative. We've identified five types of transients and several important features of the model's behavior near the stabilization area boundary. Thus, the nonlinear model turned out to be unstable to small and stable to bigger perturbations in the unstable area of its linearization. The steady-state oscillations at the boundary have a lower amplitude with increasing of an initial perturbation, etc.

Влияние нелинейности закона намагничивания феррожидкости на неустойчивость Кельвина--Гельмгольца

We study Kelvin-Helmholtz instability which develops when a homogenous gas flow is moving over a horizontal surface of a ferrofluid of given physical properties moving in the same direction, in presence of a homogeneous magnetic field parallel to this direction. Magnetic field intensity range includes the values that correspond to the interval where magnetization curve reaches magnetization saturation level. Stability area is constructed in the “magnetic field intensity – dimensionless relative velocity of fluids” parameter plane.

AUTHENTICATION OF PERSONAL COMPUTERS WITH UNSTABLE INTERNAL NOISE

The article is devoted to the study of the stability authentication signs of personal computers; possibility of authentication follows from their physical differences as complex electronic devices. This approach provides the ability to remotely automatic authentication in real time. The authentication template was calculated from the sequence of values of the auto-correlation function of the internal electrical noise. It was demonstrated that the noise instability of noise leads to the error in the computer authentication. In order to reduce the error's probability, it was proposed to use the form-factor of autocorrelation function histogram for automatic sorting of noise files. The character of the noise instability had allowed the use of several authentication templates for one computer with instable noise. Each template was designed for the separate stability area. The probability of false authentication was reduced by using two authentication templates for one computer with instable noise, it was 30%. The recommendations were made about determining the priority of access to confidential information for computer with instable noise.

The Relationship Between Postural Stability, Anthropometry Measurements, Body Composition, and Sport Experience in Judokas with Visual Impairment

Background: Postural stability is quite mandatory when practicing high-performance sports. Investigations of postural stability and related variables in judokas with visual impairment can lead to new training plans targeting the improvement of postural stability and ultimately to enhanced performance. Objectives: To investigate postural stability and its relationship with anthropometric measurements, body composition, and experience in judokas with visual impairment. Methods: Seventeen judokas (70.6% men) with visual impairment participated in this cross-sectional study. The athletes were grouped based on the functional classification of partial (B2/B3, n = 10) and total visual impairment (B1, n = 7). Postural stability was assessed using the elliptical area of the 95% confidence interval (Area) and the average displacement velocity (Vavg) while remaining in a bipedal stance with eyes closed and blindfolded. Body mass, height, circumferences, skinfold thickness and diameters were measured and used to estimate body composition. Between-group comparisons were evaluated using the Mann-Whitney test. Bivariate correlations were determined with Spearman’s correlation coefficient with bootstrap analysis and 95% confidence interval (95% CI) from 500 resamplings. Results: No significant difference was observed between the B1 and B2/B3 groups in relation to postural stability (Area; P = 1.00; Vavg; P = 0.85). Postural stability (Area but not Vavg) correlated positively and moderately (P < 0.05) with anthropometric measurements and negatively with judo experience (practice time). Conclusions: The postural stability of judokas was unrelated to the degree of visual impairment. Postural instability was correlated with anthropometric measurements, mainly body fat and height, and judo experience.

The Relationship Between Trunk Muscle Thickness and Static Postural Balance in Older Adults

Trunk muscles are required for safety of movement in aging. The authors aimed to investigate the relationship between trunk muscle thickness and the static postural balance in older adults. A total of 31 females and 23 males with a mean age of 73.39 ± 6.09 completed the study. The thickness of the trunk muscles was determined with ultrasound imaging. Postural balance was assessed with force plate. There was a positive weak correlation between right and left upper rectus abdominis muscle thickness and anterior stability area (p < .05, r > .3). The negative and moderate correlation was determined between the left lower rectus abdominis and the perturbated stability sway value (p < .01, r > .5). The increase in trunk muscle thickness in older adults increases the postural stability area and decreases the postural sway especially in the mediolateral direction.