aggregation

The main approaches for the formation of generalized conclusions about operation quality of complex hierarchical network systems are analyzed.  Advantages and drawbacks of the ``weakest'' element method and a weighted linear aggregation method are determined.  Nonlinear aggregation method is proposed for evaluating the quality of the system, which consists of elements of the same priority.  Hybrid approaches to form generalized conclusions are developed based on the main aggregation methods.  It is shown that they allow us to obtain more reliable generalized conclusions.

IP traffic is growing and seting new tasks for improving the quality of telecommunications services. To resolve this problem in this paper has been proposed IP over OTN over DWDM network architecture, which peculiarity is OTN level that separates the logical and physical topology in IP / MPLS and DWDM networks with MPLS control plane. In the proposed architecture IP / MPLS routers has been connected to multyservice optical transport platforms.

The formation of aggregates of a fraction of asphaltenes extracted from Brazilian crude oil was investigated by measuring the interfacial tension and kinematic viscosity of their solutions prepared in different solvents. The interfacial tension results indicate the existence of critical micelle concentration (CMC) levels of the asphaltenes in solvents with solubility parameters sufficiently different from those of the asphaltene tested. The kinematic viscosity measures revealed the formation of aggregates at concentrations above the CMC.

The results are given for studying the coal tar carbonaceous dispersed phase with a number of microscopes of various principles of operation. High trend is shown for the dispersed particles to form stabile aggregates and to adsorb other tar compounds on their surface. The conclusion is made that the selective extraction of the dispersed phase from the coal tar is fundamentally impossible. The well-founded hypothesis is expressed about the technological practicability of the tar dispersed phase aggregates destruction for the quality upgrading of the tar-based products.

It has been shown that two types of nanofiller aggregation processes are realized during polymer/carbon nanotubes nanocomposites production: formation of nanotubes ropes and their bending. The first one from the indicated processes is realized at carbon nanotubes contents larger than the percolation threshold. The ultrasound affects only carbon nanotubes aggregation of the second type.

It has been shown that aggregation (tangled coils formation) of carbon nanotubes begins at their very small contents. This factor strongly reduces reinforcement degree of polymer/carbon nanotube nanocomposites. Estimation of the main parameters that influenced elasticity modulus of the mentioned nanocomposites was fulfilled. Theoretical calculations showed high potential of nanocomposites filled with nanotubes.