Good quality communication in the family is a source of positive relations among its members. It is the most important characteristic of a well-functioning family. Very interesting perceptions of communication in the family are held by high achieving students. In those young people, communication in the family correlates negatively with their high grade point average. Also, they evaluate positively communication in the family as a whole but less positively one-to-one verbal interactions with the mother and the father. This observation is explained by the fact that the family forms a system. Moreover, communication is associated with positive relationships and attitudes such as acceptance and autonomy, but correlates negatively with control, over-demanding behaviour, and inconsistency in the parents of high achieving students.
The transient thermal model of the permanent magnet linear actuator (PMLA) has been considered. The characteristics of heating have been calculated including the main subdomains of the actuator. The carcasses from various materials have also been considered. The calculations have been verified experimentally and a good conformity was obtained.
The paper presents investigation results of the natural balancing phenomena in the flying-capacitor SEPIC converters. The SEPIC converters topologies can be reconfigured to the flying-capacitor topology. Owing to this modification the advantageous increase of frequency of the current in the chokes and the decrease of semiconductors voltages can be achieved which is shown in this paper. Similarly to other multilevel flying capacitor topologies the adequate voltage sharing of the flying capacitors is an important issue for safe operation of the converter. The paper focuses on the analysis of the flying capacitor voltages balancing in the converter by natural currents as well as by the application of the additional RLC balancing booster. The paper proves that the natural balancing can be achieved by the specific application of the balancing circuit in the flying-capacitor SEPIC topology and proves the specific differences in the balancing process by natural currents of converter and with the usage of the balancing circuit. An operation of the converter with the balancing circuit and the natural balancing ability is studied here.
In this study, a procedure for optimal selection of measurement points using the D-optimality criterion to find the best calibration curves of measurement sensors is proposed. The coefficients of calibration curve are evaluated by applying the classical Least Squares Method (LSM). As an example, the problem of optimal selection for standard pressure setters when calibrating a differential pressure sensor is solved. The values obtained from the D-optimum measurement points for calibration of the differential pressure sensor are compared with those from actual experiments. Comparison of the calibration errors corresponding to the D-optimal, A-optimal and Equidistant calibration curves is done.
The paper presents application of a modified, symmetrical Bouc-Wen model to simulate the mechanical behaviour of high-frequency piezoelectric actuators (PAs). In order to identify parameters of the model, a two-step algorithm was developed. In its first stage, the mechanical parameters were identified by taking into account their bilinear variability and using a square input voltage waveform. In the second step, the hysteresis parameters were determined based on a periodic excitation. Additionally, in order to reduce the influence of measurement errors in determination of selected derivatives the continuum wavelet transform (CWT) and translation-rotation transformation (TRT) methods were applied. The results proved that the modified symmetrical Bouc-Wen model is able to describe the mechanical behaviour of PAs across a wide frequency range.
Climate change has been affecting plants over the last century and caused
changes in life history features such as the flowering time. Herbarium specimens provide
a snapshot of the past environmental conditions during their collection. The collection
date in a herbarium specimen is a good proxy to determine the flowering period (phenology).
In this study, phenological data from subarctic plant specimens collected over
100 years were gathered by using one of the largest herbarium databases in the World.
The collection dates of 7146 herbarium specimens were analyzed and significant shifts
in the phenology of subarctic plants were detected. In this study, most of the analyzed
142 species in a subarctic biogeographic region tended to flower earlier in the 1950–2018
period compared to the 1900–1949 as a possible result of the climate change. Flowering
time shifted from 8 to 26 days in some species. Changes in flowering time may
alter species interactions, community composition, and species distribution in a region.
Therefore, results of this study may shed light on the possible shifts in phenology and
plant responses under the climate change.
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