Conference – 1992 Equation

r at = ( 1 τ ) i π 1 + π MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOCamaaBa aaleaacaqGHbGaaeiDaaqabaGccqGH9aqpdaWcaaqaamaabmaabaGa aGymaiabgkHiTiabes8a0bGaayjkaiaawMcaaiaabMgacqGHsislcq aHapaCaeaacaaIXaGaey4kaSIaeqiWdahaaaaa@45FA@