Each vice president shall perform such duties and have such authority as from time to time may be delegated to him by the chief executive officer, the president or by the Board. The Board shall have the authority to append such prefixes as “executive,” “senior” and “assistant” to any vice president’s title as it shall determine. In the absence of the chief executive officer and the president or in the event of the president’s death, inability, or refusal to act, such vice president as shall have been designated by the Board or, in the absence of such designation, by the chief executive officer, shall perform the duties and be vested with the authority of the president.