53 results about "Cauchy boundary condition" patented technology

The invention relates to a method for carrying out parallelization numerical simulation on hydrodynamic force conditions of a river provided with a cascade hydropower station. According to the method, a closed equation set is established for each course by setting an upper level or a flow-level relation of a river channel structure as a lower boundary condition of an upper reach and supposing that a lower level of the structure is used as an upper boundary condition of a lower reach; and each equation set only comprises variables of the same reach, a coefficient matrix formed by adopting an implicit difference scheme to carry out dispersion are still kept having the banded characteristics and the physically related reaches are relatively independent on the aspect of value, so that the variables of the reaches can be solved by applying the banded matrix and the aim of ensuring the flows at both sides of the structure equal is fulfilled by iterating and correcting the lower level of the structure. Compared with the conventional method of solving the hydrodynamic conditions of the river by the single course, the method disclosed by the invention has the advantages that the rapid parallel solution of the multi-course river hydrodynamic conditions can be implemented without modifying an original sequence program of solving the river hydrodynamic conditions on a large scale; the operation process has short time consumption; and the efficiency is high.

A method and apparatus for interpolating values for a color space from an input color value. A unit hypercube enclosing the input value is generated based on values from a look up table. A set of boundary conditions are then imposed on the unit hypercube. To perform the actual interpolation, an initial barycentric projection is performed from a selected vertex of the unit hypercube through the input value onto a boundary of the unit hypercube. If the projection satisfies one of the boundary conditions, an interpolated value is calculated using the projection by back substitution. If the initial projection does not satisfy a boundary condition, an intermediate value is generated from the previous projection and successive barycentric projections are performed using respectively different vertices of the unit hypercube through intermediate values onto a boundary of the unit hypercube until a projection satisfies one of the boundary conditions.

In a method for operation of a magnetic resonance system, at least one control device is fashioned for image data acquisition and corresponding components, and only three first control parameters defining primary boundary conditions are selected by an operator of the system, namely the contrast response, the spatial orientation of the at least one image data set to be acquired and the examination organ. Additional, second control parameters, required to control the components for image acquisition and defining secondary boundary conditions, are automatically determined by the control device using the first control parameters.

Systems and methods of simulating an explosion in time-marching finite element analysis are disclosed in the present invention. A method is configured for increasing user (e.g., engineer or scientist) productivity by reducing computation time of simulating fluid-structure interaction due to an explosion. The method comprises a creation of a finite element analysis model that includes structure, surrounding fluid, a blast source of the explosion and a single layer of ambient elements each having a segment representing a boundary of the fluid facing the blast source. Each ambient element is associated with a particular finite element representing the fluid at the boundary. The ambient elements are configured to be situated between the blast source and the structure such that the simulation can be carried on a set of boundary conditions specified thereon. The boundary conditions comprise a set of nodal velocities that are determined from the empirical formula (e.g., Friedlander equation).