Problems related to the existence of integral and rational points on cubic curves date back at least to Diophantus. A significant step in the modern theory of these equations was made by Siegel, who proved that a nonsingular plane cubic equation has only finitely many integral solutions. Examples show that simple equations can have inordinately large integral solutions in comparison to the size...

The traditional crossover operator used in genetic search exhibits a position-dependent bias called the dcfining-length bias. We show how this bias results in hidden biases that are difficult to anticipate and compensate for. We introduce a new crossover operator, shuffle crossover, that eliminates the position dependent bias of the traditional crossover operator by shuffling the representation...

In this paper, an iterative method is proposed for solving large general Sylvester matrix equation $AXB+CXD = E$, where $A in R^{ntimes n}$ , $C in R^{ntimes n}$ , $B in R^{stimes s}$ and  $D in R^{stimes s}$ are given matrices and $X in R^{stimes s}$  is the unknown matrix. We present a global conjugate gradient (GL-CG) algo- rithm for solving linear system of equations with multiple right-han...

there are various parameters that affect stability and expansion of failure zones in under pressure tunnels. among the important parameters that affect failure zones around the tunnels are cohesion and internal friction angle of the rock mass. in addition, the cross sectional shape is the considerable point in failure distribution around the tunnels. the stress analysis method is one of the app...

OBJECTIVE To evaluate the importance of food supplementation as incentive in improving preantiretroviral therapy (pre-ART) adherence, and second its impact on health of HIV-infected children by a clinic-based observational study. METHODS HIV-seropositive children aged between 2 and 12 years were followed-up sequentially for 2 years without and with food supplementation, respectively, with mon...

The displacement back analysis is an effective means on inversion of rock mechanical parameters. Differential evolution algorithm has many advantages and good prospects to solve problems of geotechnical parameters. The program is used to the simulation of the true tunnel with C++ language, while it is embedded into differential evolution algorithm to achieve the inversion parameter. Applying to...