Компартментальное моделирование транспортных процессов в корне растения, учитывающее присутствие пограничных слоев
Basing on the information about the structure of the solution and asymptotic estimates in the problem of steady flow across the root, a system of algebraic relations similar to the commonly used compartment models is obtained. As compared with these, the method proposed has an important advantage making it possible to take into account the characteristic features of the anatomical structure of the root and the non-uniformity of the parameter distribution over its cross-section. This enables us to formulate simple finite relationships fitting with sufficient accuracy with the numerical solution obtained within the framework of the continuum model. The application of the approach proposed to solving specific problems is simpler than both the numerical solution based on the continuum model and the solution obtained by asymptotic methods.
The mathematical modelling is performed to study the effect of the permeability of the Casparian bands to water and solutes on the formation of the root pressure. It is shown that the pressure in the xylem vessels which stops the flow across a root cut (root pressure) decreases with increase in the permeability of the Casparian bands to solutes at a fixed hydraulic conductivity. However, if the Casparian bands are permeable to water alone and impermeable to solutes, then changes in the root pressure changes are not observed.
This book constitutes the joint refereed proceedings of the 15th International Conference on Next Generation Wired/Wireless Advanced Networks and Systems, NEW2AN 2015, and the 8th Conference on Internet of Things and Smart Spaces, ruSMART 2015, held in St. Petersburg, Russia, in August 2015. The 74 revised full papers were carefully reviewed and selected from numerous submissions. The 15 papers selected for ruSMART are organized in topical sections on IoT infrastructure, IoT platforms, smart spaces and IoT cases, and smart services and solutions. The 59 papers from NEW2AN deal with the following topics: streaming, video, and TCP applications, mobile "ad hoc" networks, security, and clouds, sensor networks and IoT, cellular systems, novel systems and techniques, business and services, signals and circuits, optical and satellite systems, and advanced materials and their properties.
A computational approach to the analysis of structural and dynamical properties of all components of model membranes - membrane proteins, lipids, water and ions - has been developed. It is established that local changes in the membrane environment play an important role in the binding of membrane-active peptides and peripherical membrane proteins, causing specific clustering of lipids and initiating the formation of defects in the membrane. It is shown for the first time that lipids make a significant contribution to the free energy of spontaneous dimerization of membrane proteins. The detailed balance of various energy contributions strongly depends on the composition of the membrane and the amino acid sequence of the protein. The assumption is made that the process of association of transmembrane alpha-helices in lipid bilayers has a predominantly entropic character.
While operators have finally started to deploy fourth generation broadband technology, many believe it will still be insufficient to meet the anticipated demand in mobile traffic over the coming years. Generally, the natural way to cope with traffic acceleration is to reduce cell size, and this can be done in many ways. The most obvious method is via picocells, but this requires additional CAPEX and OPEX investment to install and manage these new base stations. Another approach, which avoids this additional CAPEX/OPEX, involves offloading cellular traffic onto direct D2D connections whenever the users involved are in proximity. Given that most client devices are capable of establishing concurrent cellular and WiFi connections today, we expect the majority of immediate gains from this approach to come from the use of the unlicensed bands. However, despite its huge commercial success, WiFi-based direct connectivity may suffer from stringent session continuity limitations, excessive user contention, and cumbersome manual setup/security procedures. In this article, we detail our vision of integrating managed D2D communications into current cellular technology to overcome the limitations of WiFi. We also quantify the estimated network performance gains from offloading cellular traffic onto D2D connections. Our analysis is based on an advanced system-level simulation toolkit that captures the relevant details of the network environment, and a detailed characterization of dynamic D2D communications based on stochastic geometry. We conclude that D2D communications provide a significant boost to network capacity as well as user energy efficiency and quality of service perception.
A model for organizing cargo transportation between two node stations connected by a railway line which contains a certain number of intermediate stations is considered. The movement of cargo is in one direction. Such a situation may occur, for example, if one of the node stations is located in a region which produce raw material for manufacturing industry located in another region, and there is another node station. The organization of freight traﬃc is performed by means of a number of technologies. These technologies determine the rules for taking on cargo at the initial node station, the rules of interaction between neighboring stations, as well as the rule of distribution of cargo to the ﬁnal node stations. The process of cargo transportation is followed by the set rule of control. For such a model, one must determine possible modes of cargo transportation and describe their properties. This model is described by a ﬁnite-dimensional system of diﬀerential equations with nonlocal linear restrictions. The class of the solution satisfying nonlocal linear restrictions is extremely narrow. It results in the need for the “correct” extension of solutions of a system of diﬀerential equations to a class of quasi-solutions having the distinctive feature of gaps in a countable number of points. It was possible numerically using the Runge–Kutta method of the fourth order to build these quasi-solutions and determine their rate of growth. Let us note that in the technical plan the main complexity consisted in obtaining quasi-solutions satisfying the nonlocal linear restrictions. Furthermore, we investigated the dependence of quasi-solutions and, in particular, sizes of gaps (jumps) of solutions on a number of parameters of the model characterizing a rule of control, technologies for transportation of cargo and intensity of giving of cargo on a node station.
This proceedings publication is a compilation of selected contributions from the “Third International Conference on the Dynamics of Information Systems” which took place at the University of Florida, Gainesville, February 16–18, 2011. The purpose of this conference was to bring together scientists and engineers from industry, government, and academia in order to exchange new discoveries and results in a broad range of topics relevant to the theory and practice of dynamics of information systems. Dynamics of Information Systems: Mathematical Foundation presents state-of-the art research and is intended for graduate students and researchers interested in some of the most recent discoveries in information theory and dynamical systems. Scientists in other disciplines may also benefit from the applications of new developments to their own area of study.