in this paper the problem of minimizing the total transmitting power subject to a fixedtotal bit rate in ofdm systems is considered. upper bounds on transmitting power and bit rate ofeach subcarrier can also be taken into account. in practice, the number of bits of each subcarriershould be integer and nonnegative. in this paper an analytical optimal solution is derived for thecase of assuming t...

In this paper, we investigate multi-symplectic Runge-Kutta-Nyström (RKN) methods for nonlinear Schrödinger equations. Concatenating symplecitc Nyström methods in spatial direction and symplecitc Runge-Kutta methods in temporal direction for nonlinear Schrödinger equations leads to multi-symplecitc integrators, i.e. to numerical methods which preserve the multi-symplectic conservation law (MSCL)...

In recent years, a number of models of lexical access based on attractor networks have appeared. These models reproduce a number of effects seen in psycholinguistic experiments, but all suffer from unrealistic representations of lexical semantics. In an effort to improve this situation we are looking at techniques developed in the information retrieval literature that use the statistics found i...

Currently, the research of emergency supplies distribution and decision models mostly focus on deterministic models and exact algorithm. A few of studies have been done on the multi-level distribution network and matheuristic algorithm. In this paper, random processes theory is adopted to establish emergency supplies distribution and decision model for multi-level network. By analyzing the char...