Gang X Xu

US Patent:

7676352, Mar 9, 2010

Filed:

Apr 19, 2005

Appl. No.:

11/109840

Inventors:

David J. Van Peursem - Irvine CA, US
Gang Xu - Corona CA, US

Assignee:

Invensys Systems, Inc. - Foxboro MA

International Classification:

G06F 9/455

US Classification:

703 9, 703 2, 73 2501, 137828

Abstract:

A method of estimating a thermophysical property of a fluid using a local model is disclosed herein. The method includes generating, for use within the local model, a series expansion of thermodynamic equations relating to the thermophysical property and one or more derivatives involving the thermophysical property. The method further includes evaluating, based upon a set of specified values of parameters of the fluid, a first order term of the series expansion and a second order term of the series expansion. The values of the first order term and the second order term are then compared. A value of the thermophysical property is then automatically updated when the values of the first order term and the second order term are found to differ by more than a predefined amount.

US Patent:

7987082, Jul 26, 2011

Filed:

Feb 1, 2010

Appl. No.:

12/698063

Inventors:

David J. Van Peursem - Irvine CA, US
Gang Xu - Corona CA, US

Assignee:

Invensys Systems, Inc. - Foxboro MA

International Classification:

G06F 9/455

US Classification:

703 9, 73 2501

Abstract:

A method of estimating a thermophysical property of a fluid using a local model is disclosed herein. The method includes generating, for use within the local model, a series expansion of thermodynamic equations relating to the thermophysical property and one or more derivatives involving the thermophysical property. The method further includes evaluating, based upon a set of specified values of parameters of the fluid, a first order term of the series expansion and a second order term of the series expansion. The values of the first order term and the second order term are then compared. A value of the thermophysical property is then automatically updated when the values of the first order term and the second order term are found to differ by more than a predefined amount.

US Patent:

8165860, Apr 24, 2012

Filed:

Aug 25, 2009

Appl. No.:

12/547145

Inventors:

Gang Xu - Irvine CA, US
David Bluck - Yorba Linda CA, US
David J. Van Peursem - Irvine CA, US
Ian H. Boys - Vista CA, US

Assignee:

Invensys Systems, Inc - Foxboro MA

International Classification:

G06F 9/455

US Classification:

703 12

Abstract:

A system for thermodynamic modeling is provided. The system comprises a computer having a processor, a thermodynamic process simulation application, and a thermodynamic equation of state application. When executed by the processor, the thermodynamic equation of state application determines a density root based on a first and second point of departure from an equation of state and based on a first and a second extrapolation equation. The first departure point satisfies the equation.

US Patent:

8364316, Jan 29, 2013

Filed:

Sep 15, 2009

Appl. No.:

12/560134

Inventors:

Gang Xu - Irvine CA, US
David Bluck - Yorba Linda CA, US

Assignee:

Invensys Systems, Inc. - Foxboro MA

International Classification:

G01N 15/06
G01N 33/00
G01N 33/48

US Classification:

700270, 700 1, 700266, 702 22, 702 30, 702 31, 702127

Abstract:

A method of modeling phase characteristics of thermodynamic systems utilizing pseudo-properties strategy and a reduced number of variables is disclosed herein. The method describes a means of determining the probability of phase splitting of mixtures of materials at a given temperature, pressure, and composition by characterizing the functions that describe the system via pseudo-properties, and also by describing the system in n−1 or fewer variables, where n represents the number of components in the system of interest. In an embodiment, a multi-component system is characterized in one variable, thereby providing simplified thermodynamic models in a time-efficient manner. In addition, the information generated by this reduced-variable calculation can further be used as a starting point for calculations of equations of state.

US Patent:

20090168459, Jul 2, 2009

Filed:

Dec 27, 2007

Appl. No.:

11/965644

Inventors:

Robert L. Holman - Evanston IL, US
Matt Sampsell - Chicago IL, US
Russell Wayne Gruhlke - Mulpitas CA, US
Gang Xu - Cupertino CA, US
Marek Mienko - San Jose CA, US

Assignee:

QUALCOMM Incorporated - San Diego CA

International Classification:

F21V 7/04
H01J 9/02

US Classification:

362623, 445 24

Abstract:

In various embodiments described herein, a front light guide panel comprises a plurality surface relief features having a variety of different sloping surface portions. Light injected into an edge of the light guide propagates though the light guide until it strikes one of the surface relief features. The light is then turned by total internal reflection such that the light is directed onto a reflective modulator array rearward of the light guide panel. The light reflects from the modulator array and is transmitted back through the surface features of the light guide panel. However, depending upon where the light is incident on the surface features, the light will be refracted at different angles by the different sloping surface portions. As a result, light reflected from a single point on the modulator array appears to originate from different locations, and ghost images appear. To reduce such ghosting, a conjugate film having equal and opposite surface relief features is disposed forward of the light guide panel. Light reflected from the modulator array and passing through surface relief features on the light guide panel is refracted a second time by the conjugate film to return the rays to their original trajectory.

US Patent:

20100182308, Jul 22, 2010

Filed:

Oct 5, 2007

Appl. No.:

12/444156

Inventors:

Robert L. Holman - Evanston IL, US
Matt Sampsell - Chicago IL, US
Russell Wayne Gruhlke - Milpitas CA, US
Marek Mienko - San Jose CA, US
Gang Xu - Cupertino CA, US
Ion Bita - San Jose CA, US

International Classification:

G06F 3/038
F21V 7/04
H01J 9/00

US Classification:

345214, 362609, 445 23

Abstract:

An illumination apparatus includes a light bar, a plurality of indentations in the light bar on a first side of the light bar, and a contoured reflective surface including a plurality of protruding surface portions, such that the surface portions reflect light transmitted through sloping sidewalls of the indentations. The light bar has a first end for receiving light from a light source. The light bar includes material that supports propagation of the light along the length of the light bar. The turning microstructure is configured to turn at least a substantial portion of the light incident on the first side and to direct the portion of light out the second opposite side of the light bar. The protrusions on the contoured reflective surface and the indentations on the light bar can have complimentary shapes and/or aligned in certain embodiments.

US Patent:

20200050158, Feb 13, 2020

Filed:

Oct 18, 2019

Appl. No.:

16/657833

Inventors:

- Lake Forest CA, US
Gang Xu - Irvine CA, US

International Classification:

G05B 17/02

Abstract:

Simulation of process control environments, including dynamic properties, with a modified first-order Taylor series expansion. By using more linear calculations, a physical dynamic property is approximated in less time and with fewer computing resources. By adjusting the approximation to introduce curvature, a physical dynamic property is represented over a wider range than with basic linear series expansions. A comparison to a basic linear first-order series expansion identifies conditions when a rigorous update of a dynamic property is needed.

US Patent:

20170115644, Apr 27, 2017

Filed:

Oct 22, 2015

Appl. No.:

14/919887

Inventors:

- Foxboro MA, US
Gang Xu - Irvine CA, US

Assignee:

Invensys Systems, Inc. - Foxboro MA

International Classification:

G05B 17/02

Abstract:

Simulation of process control environments, including dynamic properties, with a modified first-order Taylor series expansion. By using more linear calculations, a physical dynamic property is approximated in less time and with fewer computing resources. By adjusting the approximation to introduce curvature, a physical dynamic property is represented over a wider range than with basic linear series expansions. A comparison to a basic linear first-order series expansion identifies conditions when a rigorous update of a dynamic property is needed.