By Michael S. Derby (Reuters) -Federal Reserve Bank of Dallas President Lorie Logan said Thursday the time has come for the central bank to modernize how it manages money market conditions to achieve its monetary policy objectives. To do this, Logan said the central bank’s long-standing practice of targeting the federal funds lending market needs to shift, with the Fed instead managing liquidity to control the trading level of the tri-party general collateral rate, or TGCR, given the vibrancy of that mar ...