Alan F Shih

US Patent:

20100155555, Jun 24, 2010

Filed:

Dec 24, 2009

Appl. No.:

12/647372

Inventors:

Alan Shih - San Jose CA, US

International Classification:

F16M 13/00
G06F 1/16

US Classification:

2482292, 36167902

Abstract:

An attachment device for attaching an external object to a portable computer, comprising: a first clip for coupling the portable computer to the attachment device; a second clip for coupling the external object to the attachment device; and a member for connecting the first clip and the second clip.

US Patent:

59496053, Sep 7, 1999

Filed:

Mar 18, 1997

Appl. No.:

8/816769

Inventors:

Ho Seong Lee - Palo Alto CA
Alan SunTzi Shih - San Jose CA
Steven Wayne Burge - San Jose CA
Mark Andrew Pajdowski - Los Gatos CA

Assignee:

Seagate Technology, Inc.

International Classification:

G11B 5596

US Classification:

360 7704

Abstract:

An adaptive feedforward method of canceling and calibrating harmonic disturbances in a magnetic disk drive storage system includes expressing harmonic disturbances to the system as d(t) and expressing an output of the system as y(t). A control signal u(t) is used to cancel the harmonic disturbance d(t), where u(t) is the estimated value of d(t) such that u(t) is an estimated value of d(t). Estimated coefficients a. sub. i and b. sub. i of u(t) are updated using the derivatives of the estimated coefficients and a constant adaptation gain g. sub. i for the ith frequency component of the disturbance. The values of estimated coefficients are implemented in real time. The control signal u(t) is combined with the system output signal y(t) to cancel u(t) from y(t). The functions representing d(t), y(t), and u(t) are included in drive code for the system. A sine function is implemented by a polynomial curve fitting method and the sine function is approximated as a polynomial function for a quarter cycle of the sine function using only four data points.