求英语大神给翻译一段话，谢谢了~~论文中要用，尽量翻译的有文采一些，拜托

求英语大神给翻译一段话，谢谢了~~论文中要用，尽量翻译的有文采一些，拜托
Abstract. We consider a plain vanilla,fixed-for-floating interest rateswap whose notional principal is equal to the outstanding principal of aloan.Since the outstanding principal of a loan decrease,so dose the notionalprincipal of the swap.In some cases the rate of repayment might be higher thanthe originally expected one,that is,arrears.Therefore it may happen that thetransition of the amount of outstanding principal differs from the originallyexpected one.To establish evaluation method of these risks is very importantfor financial institutions.We deduce an evaluation formula in an analytic formfor swap contracs including risks of prepayment an arreaes.We also swap ratesin analytic from for these swap contracts