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In present paper we develop the description of massless fields on the
basis of space-time algebra of sixteen-component sedeons. The generalized
sedeonic second-order equation for unified gravito-electromagnetic (GE) field
describing simultaneously weak gravity and electromagnetism is proposed. The
relations for the GE field energy, momentum and Lorentz invariants are derived.
The special case of GE field described by first-order sedeonic wave equation is
It is very important in pollution treatment to clarify the space-time distribution of water quality in Dianchi Lake. Based on the sample data obtained from 10 observation stations every month from 2008 to 2009, it uses space-time semi-variogram and ordinary kriging method to simulate the space-time variance and distribution of water quality indictors (TN, TP, BOD, CODMn, DO, Chlorophyl-α, etc.). Because the space-time semivariogram also has a certain of ex-trapolation function. From the simulation results, the pollution is mainly concentrated at the North (Caohai) and the Southwest area (Haikou), and water pollution has a increase trend.
In this short survey, we give a complete
list of the most important results obtained by El Naschie’s E-infinity
Cantorian space-time theory in the realm of quantum physics and cosmology.
Special attention is paid to his recent result on dark energy and revising
Einstein’s famous formula .
Full-rate is very important in
any data transmission coding. For transmitting data at low bit rate than
full-rate code, higher modulation scheme is required. But it is impossible to
design full rate orthogonal designs with complex constellation for more than
two transmit antennas. Only Alamouti code provides full-rate for two transmit
antennas. In this paper, Bit Error Rate (BER) is calculated for
Quasi-Orthogonal Space-time Block Coding (QOSTBC). Here we work with Rayleigh
fading channel. We consider the codes which decodes pairs of symbols instead of
simple separate decoding like Orthogonal Space-Time Block Coding. In
Quasi-Orthogonal Space-time Block Code full-rate is achieved but full-diversity
is sacrificed. Diversity is the most important techniques for providing
reliable communication over fading channels. One of the diversity techniques
that uses multiple transmit and/or receive antennas is space diversity.
Multiple antenna technique provides a space diversity to struggle with the
fading without necessarily sacrificing bandwidth resources, so the excellent
solutions of removing the fading of the channel for broadband wireless
communications is using space diversity. Then, with the constellation rotation
of the symbol, rotated version of Quasi-Orthogonal Space-Time Block Code is
generated. It provides full diversity. We simulate BER for QOSTBC, rotated
QOSTBC, orthogonal STBC and for uncoded system. The simulation result shows
that QOSTBC and rotated QOSTBC perform better than other systems. It shows that
QOSTBC provides a full transmission rate but that rotated QOSTBC provides the full
rate with the full diversity.
We discuss the generalized
Lagrange structure of a deformed Minkowski space (DMS), , namely a
(four-dimensional) generalization of the (local) space-time based on an
energy-dependent “deformation” of the usual
Minkowski geometry. In , local
Lorentz invariance is naturally violated, due to the energy dependence of the
deformed metric. Moreover, the generalized Lagrange structure
of allows one to endow the deformed space-time
with both curvature and torsion.