James F. Hoffmaster, COO of Cognex Corp., a Natick, Mass., machine-vision systems supplier, has been given the added title and responsibility of president of the company. Hoffmaster joined Cognex after being president of Fibersense, a Massachusetts-based company applying fiber optic technology to motion and position sensors. Before that, he was president of Fisher Rosemount Systems, a division of Emerson Electric. He will oversee both of Cognex's operating divisions and will be responsible for the company's worldwide sales and corporate services departments.    . . .    Harris Corp. and DigitalGlobe, a Longmont, Colo., supplier of satellite and aerial imagery, announced they will provide high-resolution, 3-D satellite imagery to NBC to support its coverage of the 2004 Olympics from Athens, Greece. Harris is using its ImageLinks TrueTerrain technology to enhance DigitalGlobe's satellite images of Athens; the companies will also use 3-D modeling to provide detailed views of Athens landmarks, the Olympic Village and sporting venues during NBC's broadcasts of the games, to be held August 13-29.    . . .    Peter Kepf, founder and president of Pilot Automation, of Alcoa, Tenn., has joined Avalon Vision Solutions LLC, a Lithia Springs, Ga.-based supplier of industrial machine vision products, as a business development manager. Pilot Automation, a provider of factory automation products, systems and services, will be fully integrated with Avalon. Kepf will be based in Knoxville and will focus on the mid-southern US.