Modeling of the Payload Signal Generator of the UAV Radio Transmitter based on the Phase Distortion Autocompensator

A block diagram of a payload signal generator of a UAV radio transmitter with an autocompensator for phase distortion of a digital computational synthesizer with improved spectral characteristics compared to known solutions is considered. Schematic diagrams and circuit design models of the main paths of the shaper in the Micro-Cap environment with the analysis of the characteristics of the necessary radio elements and microcircuits have been developed. The simulation of the device operation in the frequency domain is carried out. Based on the simulation results, the conditions for selecting the parameters of the shaper to achieve the greatest compensation of phase distortions are formulated

Algorithms for analysis of stability and dynamic characteristics of signal generators at the physical level in FANET networks

To ensure the reliability of the physical level of Flying Ad Hoc Networks (FANET), the article substantiates the relevance of the study of stability and dynamic processes of signal formation and processing paths in the terminal and intermediate network equipment. The limitations of the known methods of the theory of automatic control, which make it difficult to perform the analysis of essentially nonlinear high-order signal generators, are shown. To analyze the stability of such formations proposed algorithm based on the use of the Nyquist criterion and approximation of the characteristic polynomial of a device by continuous piecewise functions; to analyze the dynamic characteristics of the algorithm based on spectral method of the input signal approximation and the frequency characteristics of a device by continuous piecewise functions

Application of communication systems via the ultraviolet channel in FANET networks

The possibility of providing communication in difficult conditions on the basis of Flying Ad Hoc Networks (FANET) requires the use of non-electronic means of communication. It is proposed to use optical communication in the UV-C range in the absence of line-of-sight between the nodes of the FANET network. The general scheme of the optical transmitter and receiver of UV-C range is considered and the review of the components required for its implementation, taking into account the application possibility in highly mobile small-sized UAVs, is carried out. As a result of the analysis of FANET networks with UV-C channel, physical and channel level parameters critical for network performance are revealed. Methods of adaptive change of these parameters in the practical implementation of the UV-C communication system in FANET networks are proposed

Algorithms for analysis of stability and dynamic characteristics of signal generators at the physical level in FANET networks

To ensure the reliability of the physical level of Flying Ad Hoc Networks (FANET), the article substantiates the relevance of the study of stability and dynamic processes of signal formation and processing paths in the terminal and intermediate network equipment. The limitations of the known methods of the theory of automatic control, which make it difficult to perform the analysis of essentially nonlinear high-order signal generators, are shown. To analyze the stability of such formations proposed algorithm based on the use of the Nyquist criterion and approximation of the characteristic polynomial of a device by continuous piecewise functions; to analyze the dynamic characteristics of the algorithm based on spectral method of the input signal approximation and the frequency characteristics of a device by continuous piecewise functions

Application of communication systems via the ultraviolet channel in FANET networks

The possibility of providing communication in difficult conditions on the basis of Flying Ad Hoc Networks (FANET) requires the use of non-electronic means of communication. It is proposed to use optical communication in the UV-C range in the absence of line-of-sight between the nodes of the FANET network. The general scheme of the optical transmitter and receiver of UV-C range is considered and the review of the components required for its implementation, taking into account the application possibility in highly mobile small-sized UAVs, is carried out. As a result of the analysis of FANET networks with UV-C channel, physical and channel level parameters critical for network performance are revealed. Methods of adaptive change of these parameters in the practical implementation of the UV-C communication system in FANET networks are proposed

Hydrogeological monitoring of karst activity based on regime observations in the territory of karst lakes

This article shows that the most sensitive indicator of local and regional karst activity in territories of apparent karst processes is the behaviour of karst lakes. The authors propose a hydrogeological monitoring methodology for the karst process based on the phase-measuring geoelectric control method in the coastal zone of karst lakes. The geoelectric current control of hydrogeological changes in the medium at local levels uses a multi-frequency vertical electric sounding combined with a phase-measuring method of registering the geoelectric signal. These proven methods permit to distinguish variations of spatial parameters and the electric conductivity of several layers at a time. Moreover, they significantly increase the noise resistance and sensitivity of the measuring system. An adaptive algorithm function of the measuring complex for geoelectric monitoring of karst lakes’ coastal zones was developed to control the operation of facilities and data collection systems. Based on an example of a lake where karst processes are active, the key zones of hydrogeological control were identified depending on karst manifestations. The research confirmed the possibility of local and regional monitoring of the development and forecasting of destructive karst-suffosion processes based on hydrogeological regime observations of karst lakes

Ceruloplasmin: Macromolecular Assemblies with Iron-Containing Acute Phase Proteins

Copper-containing ferroxidase ceruloplasmin (Cp) forms binary and ternary complexes with cationic proteins lactoferrin (Lf) and myeloperoxidase (Mpo) during inflammation. We present an X-ray crystal structure of a 2Cp-Mpo complex at 4.7 A resolution. This structure allows one to identify major protein-protein interaction areas and provides an explanation for a competitive inhibition of Mpo by Cp and for the activation of p-phenylenediamine oxidation by Mpo. Small angle X-ray scattering was employed to construct low-resolution models of the Cp-Lf complex and, for the first time, of the ternary 2Cp-2Lf-Mpo complex in solution. The SAXS-based model of Cp-Lf supports the predicted 1ratio1 stoichiometry of the complex and demonstrates that both lobes of Lf contact domains 1 and 6 of Cp. The 2Cp-2Lf-Mpo SAXS model reveals the absence of interaction between Mpo and Lf in the ternary complex, so Cp can serve as a mediator of protein interactions in complex architecture. Mpo protects antioxidant properties of Cp by isolating its sensitive loop from proteases. The latter is important for incorporation of Fe(3+) into Lf, which activates ferroxidase activity of Cp and precludes oxidation of Cp substrates. Our models provide the structural basis for possible regulatory role of these complexes in preventing iron-induced oxidative damage