Stephen D Coffman

US Patent:

6965564, Nov 15, 2005

Filed:

Feb 14, 2003

Appl. No.:

10/371335

Inventors:

Stephen Blaine Coffman - Anaheim CA, US

Assignee:

America Online, Inc. - Dulles VA

International Classification:

H04L001/00

US Classification:

370231, 370282, 370311

Abstract:

Systems are provided for sequencing, delivery acknowledgement, and throttling of data packets over a network layer, such as UDP and SMS. To support devices with limited battery resources, the invention incorporates asymmetric retry logic and/or acknowledgements with overlapping ranges, to minimize the transmissions required for the device. The sender of a data-bearing frame does not need to wait for a frame to be acknowledged before sending the next, such that many frames can be “in flight” at once.

US Patent:

51875390, Feb 16, 1993

Filed:

Sep 23, 1991

Appl. No.:

7/763784

Inventors:

Iwao P. Adachi - Westminster CA
Stephen B. Coffman - Anaheim Hills CA

Assignee:

Rockwell International Corporation - Seal Beach CA

International Classification:

G01B 1127

US Classification:

356124

Abstract:

An apparatus and method are disclosed for characterizing the surface of mirrors in which a cross-grid type phase grating is illuminated from behind by light reflected from the mirror so as to create a grid-like interference pattern when observed along an observation axis. The fringe lines in the generated or observed interference pattern are correlated to the grating and observed for relative displacement from the grating axis. Apparent fringe index numbers for the fringe lines are used to determine coefficients for a plurality of monomial series which are in turn used to derive Zernike coefficients from which a wavefront contour is obtained. In order to reduce alignment errors during analysis, each fringe line is subtracted from the next lower order line and before monomial coefficients are determined. In further embodiments of the invention, the fringe pattern is transferred, using one or more lenses, to an image digitizer such as a CCD camera which is coupled to a digital computation device that analyzes the observed fringes and computes the series coefficients and then translates them into Zernike coefficient values which are used to reconstruct the mirror surface contours.