Identification of Body Balance Deterioration of Gait in Women Using Accelerometers

This study presents a simple methodology for the evaluation of gait with accelerometers, for rapid and simple application, in which we employ current balance tests in clinical practice (Timed Up and Go, Chair Stand Test and Six-Minute Walk Test). The aim was to determine whether the accelerometric valuation of gait can detect alterations in balance. The sample of this cross-sectional research, made during the months of May and June 2018, was composed of 145 healthy adult women (x = 63.8 ± 8.41 years), from the city of Ourense (Spain). They walked with a triaxial accelerometer at the fourth lumbar vertebra for a distance of 20 m. The test was repeated three times, and the mean of the three measurements was used in the analysis. There was a reduction in the values of acceleration recorded along all three of the axes and in the root mean square as the age increased. This reduction was very significant for the minimum values registered along the vertical and transverse axes, and for the maximum values along the mediolateral axis. Only the maximum values of the vector module demonstrated significant differences among the three age groups. A regression model allowed us to identify the values that give more information on the Timed Up and Go Test, namely: the maximum values of the root mean square and the mediolateral axis. An exhaustive analysis of the vertical and mediolateral axes and the vector module allows for the detection of early alterations in the automatic gait pattern.

BINARY LINEAR TRANSFORMATIONS IN MODIFICATIONS OF RSA ALGORITHM OF IMAGES

The images are one of the most used kinds of the information in modern information company. Therefore actual problems is the organization of protection from unauthorized access and usage. An important characteristic of the image is the presence of contours in the image. The task of contour selection requires the use of operations on adjacent elements that are sensitive to change and suppress areas of constant levels of brightness, that is, contours are those areas where changes occur, becoming light, while other parts of the image remain dark. Mathematically, the ideal outline is to break the spatial function of the brightness levels in the image plane. Therefore, contour selection means finding the most dramatic changes, that is, the maxima of the gradient vector module. This is one of the reasons that the contours remain in the image when encrypted in the RSA system, since the encryption here is based on a modular elevation of some natural number. At the same time, on the contour and on the neighboring contours of the peak villages, the elevation of the brightness value gives an even bigger gap. Problem protect from unauthorized access is by more composite in matching with a problem protect from usage. Basis for organization of protection is the interpretation of the image as stochastic signal. It stipulates carry of methods of encoding of signals on a case of the images. But the images are a specific signal, which one in possesses, is padding to representative selfless creativeness, also by visual selfless creativeness. Therefore to methods of encoding, in case of their usage concerning the images, one more requirement – full noise of the coded image is put forward. It is necessary to make to impossible usage of methods of visual image processing. The algorithm RSA is one of the most used production specifications of encoding of signals. In attitude of the images there are some problems of its encoding, the contours on the coded image are in particular saved. Therefore actual problem is the mining of modification to a method RSA such, that: to supply stability to decoding; to supply full noise of the images. One of pathes of the solution of this problem is usage of affine transformations.

Complex ground diagnostic system for spacecraft electromechanical devices

One of the ways to make spacecraft electromechanical devices much reliable is the diagnostics of their technical condition during ground tests and identification of possible defects. Authors have viewed questions of spacecraft electromechanical devices’ diagnostics. There is an overview of the state-of-the-art applied diagnostic methods with the proposed complex diagnostic method, including, apart from vibration-based diagnostics, methods of the analysis of the vector module and vector hodograph of the electric engine’s equivalent current. Authors presented spectral characteristics of vibration acceleration signals and equivalent current, as well as hodographs. They also identified generic criteria for current diagnostics. The narration includes the description and function circuit of the ground complex diagnostic system for the engine of the electric pump unit (EPU) at the spacecraft thermal control system. It also includes the software interface for the system.

Двухфононная релаксация возбужденных состояний акцепторов бора в алмазе

The relaxation of holes in the excited states of boron acceptors in diamond is theoretically investigated when two optical phonons are emitted. An electron-like Hamiltonian with an isotropic effective mass was used to describe the wave function of the acceptor states. The wave function of the ground state was found by the quantum defect method. The transition probability was calculated in adiabatic approximation. The dispersion law of phonons was considered isotropic, and the frequency of phonons is quadratically dependent on the wave vector module, with the maximum value, omegamax, achieved in the center of the Brillouin zone, and the minimum, omegamin, at the edge of the Brillouin zone. The high sensitivity of the rates to the characteristic of phonon dispersion, omegamax-omegamin, especially for the transition energy, ET, in the 2homegamin≤ ET<homegamin +homegamax interval was revealed. Depending on the transition energy and dispersion of phonons, the rate of two-phonon relaxation in the low-temperature limit varies from ultra-low values (less than 108 s-1) near the threshold, ET=2homegamin, to ultra-high values (more than 1012 s-1) in the "resonance" region homegamin+homegamax≤ ET≤2homegamax.

Variability of geostrophic airflow over Poland, 1951-2014

The paper presents the analysis of the anemological conditions variability over Poland with the usage of geostrophic wind vector as an objective (and homogenous) information concerning the airflow over the area of research. The geostrophic wind vector components are calculated using SLP and air temperature (at sigma 995 level) at selected gridpoints which were subsequently interpolated to a central point thus describing the average flow over the research area. The data originated from NCEP/NCAR Reanalysis and its temporal range was 1951-2014. The analysis covers statistical characteristics of the overall annual cycle as well as trend analysis of the airflow features over Poland: geostrophic wind vector module (V), and its zonal (u) and meridional (v) components. Aside from general statistical characteristics for averages and extremes (quantiles 10% and 90%) GEV distribution was fitted to maximum annual/monthly geostrophic wind speed values which allowed the estimation of return levels for selected return periods. For the period 1951-2014 average geostrophic wind velocity over Poland equals 7.4 ms−1 and the 99% quantile exceeds 21 ms−1. Maximum speed ever recorded equalled 37.6 ms−1. Geostrophic wind vector module (V) and its components (u, v) exhibit clear annual cycle with the highest V values in winter. Positive (westerly) u values dominate in the colder part of the year. In spring the dominance of eastern advection appears and in summer the prevalence of westerly flow is only minimal. There exists a distinctive variability of decadal directional structure and this is clearly visible in the substantial increase in the share of western sector frequencies in 1981-1990 and following decade. Monthly V averages do not exhibit (except October) statistically significant trends whereas in spring and summer months as well as for annual averages of u component trend is significant. There are virtually no significant changes in the v values. GEV analysis allowed the year to be divided into two parts. Warm one with relatively low return levels – for many months not exceeding 20 ms−1 even for 50y return period. On the other hand winter months return level values exceed 30 ms−1 even for relatively short return periods (20y) with upper estimates for 100y return period closing to 40 ms−1.