Solving dynamic combinatorial problems poses a particular challenge to optimisation algorithms. Optimising a problem that does not notify the solver when a change has been made is very difficult for most well-known algorithms. Extremal Optimisation is a recent addition to the group of biologically inspired optimisation algorithms. Due to its extremely simple functionality, it is likely that the...

The popularity of direct methods for solving large sparse linear systems of equations Ax = b stems from their generality and robustness. Indeed, if numerical pivoting is properly incorporated, direct solvers rarely fail for numerical reasons; the main reason for failure is a lack of memory. Although increasing amounts of main memory have enabled direct solvers to solve many problems that were p...

background: photon attenuation as an inevitable physical phenomenon influences on the diagnostic information of spect images and results to errors in accuracy of quantitative measurements. this can be corrected via different physical or mathematical approaches. as the correction equation in mathematical approaches is nonlinear, in this study a new method of linearization called ‘piece wise line...

Nowadays, powerful parallel SAT solvers are based on an algorithm portfolio. The alternative approach, (iterative) search space partitioning, cannot keep up, although, according to the literature, iterative partitioning systems should scale better than portfolio solvers. This rises often! In this paper we identify key problems in current parallel cooperative SAT solving approaches, most importa...

Conventional iterative solvers for partial differential equations impose strict data dependencies between each solution point and its neighbors. When implemented in OpenMP, they repeatedly execute barrier synchronization in each iterative step to ensure that data dependencies are strictly satisfied. We propose new parallel annotations to support an asynchronous computation model for iterative s...

this paper presents a class of theoretical and iterative method for linear partial differential equations. an algorithm and analytical solution with a initial condition is obtained using the reduced differential transform method. in this technique, the solution is calculated in the form of a series with easily computable components. there test modeling problems from mathematical mechanic, physi...

This article introduces an iterative constraint solver for rigid body dynamics with contact. Our algorithm requires linear time and space and is easily expressed in vector form for fast execution on vector processors. The use of an iterative algorithm opens up the possibility for exploiting temporal coherence. A method for caching contact forces is presented that allows contact points to move f...

The paper presents a Generalized Aggregation Multilevel (GAM) solver, which automatically constructs nearly optimal auxiliary coarse models based on the information available in the source grid only. GAM solver is a hybrid solution scheme where approximation space of each aggregate (group of neighboring elements) is adaptively and automatically selected depending on the spectral characteristics...