Introduction: Radiotherapy is one of the effective methods in the treatment of cancer. In the recent methods of radiotherapy, intensity modulated radiotherapy (IMRT) technique by compensators is used. when photon beam passes the compensator, scattered photons can be generated within the compensator. The presence of scattered photons may complicate the design of compensators as...

Recently the compensator has been shown to be an in expensive and reliable dose delivery device for photon beam intensity-modulated radiation therapy (IMRT). The goal of IMRT compensator design is to produce an optimized primary fluence profile at the patient's surface obtained from the optimization procedure. In this paper some of the problems associated with IMRT compensator design, specifica...

When a brass compensator is set in a treatment beam, beam hardening may take place. This variation of the energy spectrum may affect the accuracy of dose calculation by a treatment planning system and the results of dose measurement of brass compensator intensity modulated radiation therapy (IMRT). In addition, when X-rays pass the compensator, scattered photons are generated within the compens...

The two-stage compensator designs of linear system are investigated in the framework of the factorization approach. First, we give “full feedback” two-stage compensator design. Based on this result, various types of the two-stage compensator designs with partial feedbacks are derived. Keywords—Linear System, Factorization Approach, Two-Stage Compensator Design, Parametrization of Stabilizing Co...

The need to eliminate distortion from power networks has led to the development of various compensator topologies. The increasing cost of electrical energy requires the choice of the most cost-effective compensator operation. An investigation of a neural-network-based controller that chooses the most cost-effective compensator mode of operation on the basis of a continuous analysis of load cond...

Heave compensator is a system that mitigates transmission of heave movement from vessels to the equipment in the vessel. In drilling industry, a heave compensator enables drilling in offshore environments. Heave compensator attenuates movement transmitted from the vessel to the drill string and drill bit ensuring security and efficiency of the offshore drilling process. Common types of heave co...

Variable structure-based robust compensators are general approaches to deal with uncertain nonlinear dynamic systems. The bang-bang (discontinuous-type) compensator and the saturation (continuous-type) compensator are the two common robust compensators used in variable structure controllers. This paper presents a comparative study of these two nonsmooth time-invariant robust compensators with a...

The build-up dose in the megavoltage photon beams can be a limiting factor in intensity-modulated radiation therapy (IMRT) treatments. Excessive surface dose can cause patient discomfort and treatment interruptions, while underdosing may lead to tumor repopulation and local failure. Dose in the build-up region was investigated for IMRT delivery with solid brass compensator technique(compensator...

This paper focuses on the control techniques employed for Distribution Static Compensator. Distributed static compensator is a device used for power quality improvement. Here we considered voltage source converter based distributed static compensator. It describes to control distribution Static Compensator employed at the distribution end. The phase shift control and AC bus /DC link voltage sch...

In this paper symbolic quantifier elimination methods are used to explore the fragility of feedback compensators, and to design feedback systems with non-fragile compensators. A compensator is said to be fragile if given variations in compensator parameters result in significant deterioration of feedback performance. The issue of fragility is important in understanding the level of acurracy req...