The values of density and velocity in the samples of the predominant rocks from the Archaean section of the Kola superdeep borehole (SG-3) drilled in the northern frame of the Pechenga palaeorift structure have been studied. The main part of rocks of the SG-3 Archaean section is represented by gneisses, schists and amphibolites. Their main rock-forming minerals are plagioclase, hornblende, mica and quartz. The texture of the rocks is mainly medium-grained, the structure is nematogranoblastic and lepidogranoblastic. The parameters of elastic anisotropy were estimated by the acoustopolariscopy method, the density and velocity of compression and shear waves were determined in the lab and the mentioned characteristics were calculated by mineral composition. The measured sample velocities are unusually low, which can be explained by the decompaction effect of deep rocks. The values of the velocity characteristics that are close to those for the conditions of the rock deep occurrence were obtained by calculation with regard to their specific mineral composition. The average values of the velocity of compression and shear waves for gneisses were calculated by mineral composition are 6.38 ± 0.16 km/s and 3.52 ± 0.14 km/s, respectively. The average of the compression wave velocity for schists is 6.40 ± 0.13 km/s, of the shear wave velocity - 3.46 ± 0.09 km/s and for amphibolites 6.84±0.13 km/s and 3.82±0.08 km/s, respectively. The dynamic moduli in different rocks are lower in schists, medium in gneisses and higher in amphibolites., Olga Trishina, Feliks Gorbatsevich and Mikhail Kovalevskiy., and Obsahuje bibliografii
This paper describes the first attempt of hardware implementation of Multistream Compression (MSC) algorithm. The algorithm is transformed to series of Finite State Machines with Datapath using Register-Transfer methodology. Those state machines are then implemented in VHDL to selected FPGA platform. The algorithm utilizes a special tree data structure, called MSC tree. For storage purpose of the MSC tree a Left Tree Representation is introduced. Due to parallelism, the algorithm uses multiple port access to SDRAM memory.
A new kind of a deterministic pushdown automaton, called a \emph{Tree Compression Automaton}, is presented. The tree compression automaton represents a complete compressed index of a set of trees for subtrees and accepts all subtrees of given trees. The algorithm for constructing our pushdown automaton is incremental. For a single tree with n nodes, the automaton has at most n+1 states, its transition function cardinality is at most 4n and there are 2n+1 pushdown store symbols. If hashing is used for storing automaton's transitions, thus removing a factor of logn, the construction of the automaton takes linear time and space with respect to the length n of the input tree(s). Our pushdown automaton construction can also be used for finding all subtree repeats without augmenting the overall complexity.
Two elementary processes - unaxial compression and creep - were chosen to demonstrate some structural effects in the mechanical behaviour of particulate materials. Six aspects of it - density, grain crushing, angularity, water effect, diffusion and garlandlike creep - were dealt with using firstly theoretical hypotheses and verifying them afterwards by laboratory experiments. Granular clay, silica gel, sand and oat flakes were experimented with. It was shown that the effect of density can be masked by other factors, granulometrical curve may change - due to grain crushing - its shape from Gauss-Laplace to concave form, angularity may radically modify the stress-strain curves, water may initiate hydrocollapses, dry granular material if loaded may be subjected to diffusion and creep may acquire a hybrid form (mixture of diffusion and garlandlike varieties). Various species of nonstandard behaviour have been described. and Obsahuje seznam literatury