We consider an extension of ordinary linear programming (LP) that adds weighted logarithmic barrier terms for some variables. The resulting problem generalizes both LP and the problem of finding the weighted analytic center of a polytope. We show that the problem has a dual of the same form and give complexity results for several different interior-point algorithms. We obtain an improved comple...

background: the purpose of this study was to investigate the application of the monte carlo technique to calculate and analysis of dosimetric parameters for electron beams used in radiotherapy. this technique is based on statistical method and has a powerful role in different radiotherapy aspects. materials and methods: the simulated medical linear accelerator was the varian clinac 2100c. the e...

We show how the CSF program design approach can be used to synthesize the classical linear programming algorithm as well as Seidel’s external algorithm.

We discuss capabilities, computational procedures, and recent improvements in the accelerator design code PARMILA. The name PARMILA stands for Phase and Radial Motion in Ion Linear Accelerators. We discuss the algorithms used in PARMILA, how the code designs individual linac sections to achieve efficient acceleration, and how it determines the distance between linac segments. We also discuss th...

Operational experience with model-driven steering in the linac of the Stanford Linear Collider is discussed. Important issues include two-beam steering, sensitivity of algorithms to faulty components, sources of disagreement with the model, and the effects of the finite resolution of beam position monitors. Methods developed to make the steering algorithms more robust in the presence of such co...

The Next Linear Collider main linacs are 13 km linear accelerators which each contain approximately 750 hybrid iron/permanent-magnet quadrupoles in a FODO array. The small amount of vertical emittance dilution permitted in the main linacs implies a tight tolerance on the RMS distance between the beam and the centers of the quads. We describe two methods for measuring the offsets between the qua...

A new GPU-based Monte Carlo dose calculation algorithm (GPUMCD), devel-oped by the vendor Elekta for the Monaco treatment planning system (TPS), is capable of modeling dose for both a standard linear accelerator and an Elekta MRI linear accelerator. We have experimentally evaluated this algorithm for a standard Elekta Agility linear accelerator. A beam model was developed in the Monaco TPS (res...

Recently, computational results demonstrated remarkable superiority of a so-called “largest-distance” rule and “nested pricing” rule to other major rules commonly used in practice, such as Dantzig’s original rule, the steepest-edge rule and Devex rule. Our computational experiments show that the simplex algorithm using a combination of these rules turned out to be even more efficient. Mathemati...