When the nodes or links of communication networks are destroyed,
its effectiveness decreases. Thus, we must design the communication network as stable as possible, not only with respect to the initial disruption, but also with respect to the possible reconstruction of the network. A graph is considered as a modeling network, many graph theoretic parameters have been ušed to describe the stability of communication networks, including connectivity, integrity, tenacity. Several of these deal with two fundamental questions about the resulting graph. How many vertices can still communicate? How difficult is it to reconnect the graph? Stability numbers of a graph measure its durability respect to break down. The neighbour-integrity of a graph is a measure of graph vulnerability. In the neighbour-integrity, it is considered that any failure vertex effects its neighbour vertices. In this work, we define the accessible sets and accessibility number and we consider the neighbour-integrity of Generalised Petersen graphs and the relation with its accessibility number.
Lead administered to laboratory rats in drinking water (0.1-0.8 %) as lead acetate solution tends to accumulate in collagen-rich tissues such as tendons and the skin. The amount of lead deposited (and also zinc present in the tissue without its supplementation) correlates with the blood supply to the tissue investigated. The highest deposits of lead were observed in placenta and chorionic membranes, though here only about 60% are collagen-bound. No differences in the drinking habits of the animals were observed and also at lower concentrations of lead in the drinking water no dose dependence was revealed. However, at 0.8 % of lead in drinking water considerable accumulation of lead was observed in all tissues investigated.
Problems related to accuracy of tilt measurements realized during experimental studies of miniature tilt sensors (including MEMS devices) are minutely discussed. The measurements are performed by means of a custom computer controlled test rig, over the full range of pitch and roll. Accuracy of the test rig is determined in terms of uncertainty of the measurements involved. Ways of improving performance of the test rig are briefly introduced. Exemplary results of experimental works are presented. and Obsahuje seznam literatury
This paper presents development of a day ahead load forecasting (DALF) model for Turkish power system with an artificial neural network (ANN). Effects of special holidays including national and religious days, and hourly random load deviations observed in Turkish power system due to significant arc furnace loads are discussed. Performance of the ANN is investigated in the sense of both DALF performance - in terms of both daily mean absolute percentage error (MAPE) and hourly absolute percentage error (APE) - and hourly secondary reserves required to ensure supply/demand adequacy of the system. The most sensitive cities to DALF in terms of daily city temperature forecasts are ranked in order to reduce the input of the developed ANN and thereby to improve execution of the model. Candidate cities are determined based on both their placement with respect to climatic zones of the country and their contribution to the system load during peak hours. The results show that, although a well-trained ANN could provide very satisfactory daily MAPEs at non-special days, such as ~1%, the hourly absolute percentage errors (APE) could be significant due to large random load disturbances, which necessitate special attention during the day ahead allocation of hourly secondary reserves. By limiting the temperature data set with major cities, the input of ANN reduces significantly while not disturbing the MAPEs. Main contributions of the study are; addressing both benefits of the prioritizing the cities in a power system in the sense of their temperature forecast effects on the DALF performance and assessing the performance of DALF in the sense of necessary amount of secondary reserves in power systems which include significant random load deviations (e.g., large arc furnace loads).
Precise relative gravimeters achieve the internal precision about a few μGal 1, even in field conditions. Nevertheless this precision is in fact concerned with the instant of measurement and can not be confused with the accuracy of the gravity at the gravity station, which is influenced by other effects. The best approach of these two values is question of high-quality elimination of instrumental errors and time-variable disturbing effects affecting the relative gravity measurements., Martin Lederer., and Obsahuje bibliografii
Wire myograph is a device for the in vitro investigation of both, active and passive properties of arteries. Arteries from a variety of animal species, pathological states, and vascular beds were investigated using this method. We focus on the normalization procedure which is aimed to standardize experimental settings and, in part, to simulate physiological conditions. During normalization, it is determined the internal circumference of a vessel stretched to a tension that corresponds to the transmural pressure of 100 mm Hg (IC100). Once it is determined, the internal circumference is traditionally set to (0.9 ⋅ IC100). However, this constant 0.9, called also the normalization factor (NF), was experimentally determined for rat small mesenteric arteries only. Therefore, the aim of our work was to show the influence of different NFs on the passive tension and reactivity of both, rat femoral arteries (FA) an d the first branches of superior mesenteric arteries (MA). We found out that the maximal active wall tension of the FA was achieved at the NF value of 1.1, and that of the MA at 0.9. Considering the values of the active wall tension we suggest that higher reactivity and better signal-to- noise ratio in FA can be achieved when the NF is set at least to 1.0., P. Slezák, I. Waczulíková, P. Bališ, A. Púzserová., and Obsahuje bibliografii