risk prediction plays an increasing role in financial risk management. this study aims to investigate existence of asymmetry and long memory volatility in tehran stock exchange index daily data over period of 1998-2006. 1467 daily index returns are used for volatility modeling via garch (long & short memory) processes for both normal and t-student innovations. the specification and forecasting ...

background lead poisoning impairs memory and learning. objectives the protective effect of natural zeolite clinoptilolite on memory and learning impairment in rats exposed to lead acetate was investigated. materials and methods 60 male wistar rats in six groups treated for 2 months with diets contained different ratios of natural zeolite(i.e. 5% or 12.5%), and %0.2 lead acetate (la) concentrati...

although investigating the factors that influence test scores is important, a majority of stakeholders show a paucity of attention towards individual learner differences due to having large classes of l2 learners. this study sought to explore the possible effect of working memory and cognitive style on l2 learners’ metaphorical test performance. the study was conducted in 2 phases. the first ph...

one of the most important items for better file system performance is efficient buffering of disk blocks in main memory. efficient buffering helps to reduce the widespeed gap between main memory and hard disks. in this buffering system, the block replacement policy is one of the most important design decisions that determines which disk block should be replaced when the buffer is full. to overc...