Serbian Abstract: У раду се разматрају проблеми одређивања оптималног распореда слова на тастатури, који мора бити заснован на карактеристикама и специфичностима...

For proper valuation of risk to which the portfolio of financial assets is exposed, it is necessary to forecast the second moments of financial time series, that is variabilities. The empirical investigations show that financia time series are heteroskedastic, i.e. their volatility is not...