BACKGROUND AND PURPOSE Most intramedullary astrocytomas have been known to exhibit at least some enhancement on MR imaging regardless of cell type or tumor grade. The purpose of this study was to evaluate the incidence of nonenhancing intramedullary astrocytomas through a retrospective study within our institutions and a systematic review of the medical literature. MATERIALS AND METHODS A tot...

since mammography images are in low-contrast, applying enhancement techniques as a pre-processing step are wisely recommended in classification of the abnormal lesions into benign or malignant. a new kind of structural enhancement is proposed by morphological operator which introduces an optimal gaussian kernel primitive, the kernel parameters are optimized the use of genetic algorithm­­. we al...

background: to enhance the dose to tumor, the use of high atomic number elements has been proposed. objective: the aim of this study is to investigate the effect of gold nanoparticle distribution on dose enhancement in tumor when the tumor is irradiated by typical monoenergetic x-ray beams by considering homogeneous and inhomogeneous distributions of gold nanoparticles (gnps) in the tumor. meth...

in this paper, experimentally derived correlations of heat transfer and pressure drop are used in a pareto based multi-objective optimization (moo) approach to find the best possible combinations of heat transfer and pressure drop of tio2-water nanofluid flow in tubes fitted with multiple twisted tape inserts in different arrangement. in this study there are four independent design variables: t...

in this paper, we propose a novel algorithm to enhance the noisy speech in the framework of dual-channel speech enhancement. the new method is a hybrid optimization algorithm, which employs the  combination of  the  conventional θ-pso and the shuffled sub-swarms particle optimization (sspso) technique. it is known that the θ-pso algorithm has better optimization performance than standard pso al...

expansive soils may cause disaster if not adequately taken care of. lime continues to be commonly used for modification of these types of soils although it may have limited success in some applications. thus, the present study was performed to address the viability of using silica fume (sf) as industrial waste to modify the behavior of expansive soils. this achieves the double objectives of ove...