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Wai Cheung Chu

from San Jose, CA
Age ~75
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Also known as:
Wai C Chu, Billy C Chu, Billy W Chu, Billy Wai Cheung
Related to:
Mable ChuSusan Wong, 64Suei Ng, 40Judy Ng
Connected to:
Ada Chu, 44Andy H Chu, 61Becky M Chu, 69Bincy B Chu, 51Bo Chu, 85Bosco C Chu, 40Bradley J Chu, 53Caly Chu, 32Carl K Chu, 91Casey C Chu, 45

Wai Chu Phones & Addresses

  • San Jose, CA
  • Milpitas, CA
  • Minneapolis, MN

Resumes

Resumes

Wai Chu Photo 1

Engineering Staff Member

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Location:
San Francisco, CA
Industry:
Computer Software
Work:
Amazon Lab126
Engineering Staff Member
Aod Tech Aug 2008 - Nov 2010
Chief Technology Officer
Shotspotter, Inc. Apr 2007 - Aug 2008
Senior Scientist
Magnum Semiconductor Jun 2006 - Apr 2007
Consultant
Docomo Usa Labs Oct 2001 - May 2006
Senior Research Engineer
Education:
Penn State University
Doctorates, Doctor of Philosophy, Electrical Engineering Stevens Institute of Technology
Masters, Electrical Engineering, Engineering Universidad Simón Bolívar
Skills:
Digital Signal Processors
Algorithms
Signal Processing
Embedded Software
C++
C
Programming
Digital Signal Processing
Image Processing
Embedded Systems
Matlab
Software Engineering
Arm
Pattern Recognition
Microcontrollers
Object Oriented Design
Machine Learning
System Architecture
Firmware
Hardware Architecture
Debugging
H.264
Microprocessors
Jpeg
Compression
Mp3
Watermarking
Architecture
Java
Speech Processing
Audio Processing
Pcb Design
Computer Vision
Manufacturing
Speech Coding
Digital Electronics
Rtos
Analog
Embedded Linux
Device Drivers
Audio
Assembly
Optimization
Interests:
Social Services
Children
Economic Empowerment
Politics
Environment
Poverty Alleviation
Science and Technology
Disaster and Humanitarian Relief
Human Rights
Animal Welfare
Health
Wai Chu Photo 2

Wai Chu

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Industry:
Marketing And Advertising
Work:
Les Brasseries Du Cameroun 2013 - 2015
Job Seeker
Wai Chu Photo 3

Wai Chu

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Wai Chu Photo 4

Wai Chu

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Wai Chu Photo 5

Wai Chu

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Wai Chu Photo 6

Wai Chu

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Location:
United States

Business Records

Name / Title
Company / Classification
Phones & Addresses
Wai K. Chu
Partner
Full Moon Seafood House
Eating Place
2042 Macarthur Blvd, Oakland, CA 94602
(510) 530-1868
Wai C. Chu
Managing
Waicchu Consulting LLC
Engineering Consulting and Import/Export
1336 Tanaka Dr, San Jose, CA 95131
2880 Zanker Rd, San Jose, CA 95134

Publications

Isbn (Books And Publications)

Speech Coding Algorithms: Foundation and Evolution of Standardized Coders

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Author

Wai C. Chu

ISBN #

0471373125

Us Patents

Secure Oblivious Watermarking Using Key-Dependent Mapping Functions

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US Patent:
6901514, May 31, 2005
Filed:
Jun 1, 2000
Appl. No.:
09/583903
Inventors:
Siu-Leong Iu - San Jose CA, US
Wai Chu - Fremont CA, US
Assignee:
Digital Video Express, L.P. - Richmond VA
International Classification:
H04L009/00
H04K001/02
US Classification:
713176, 380252, 380254
Abstract:
A method for embedding a watermark into content is disclosed. The content contains content samples. The method including the steps of: receiving the content, creating a continuous watermark sequence from the watermark, and for each content sample in a first predetermined order: calculating a sample mean, calculating a sample variance, and normalizing the content. Further steps include generating a set of content coefficients from the content, generating a set of watermark coefficients from the watermark sequence, embedding the watermark in the content by adjusting the amplitude of the watermark coefficients so that the distortion between the content coefficients and the associated watermark coefficients are minimized using a secret mapping function, and outputting the content. The mapping functions may be controlled by a key-dependent random sequence to protect the watermarks.

Gradient Descent Optimization Of Linear Prediction Coefficients For Speech Coders

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US Patent:
7200552, Apr 3, 2007
Filed:
Apr 29, 2002
Appl. No.:
10/134281
Inventors:
Wai C. Chu - San Jose CA, US
Khosrow Lashkari - Freemont CA, US
Assignee:
NTT DoCoMo, Inc. - Tokyo
International Classification:
G10L 19/12
US Classification:
704219, 704220
Abstract:
An optimization algorithm is provided for linear prediction based speech coding systems. The optimization algorithm minimizes the error between original speech samples and synthesized speech samples. Optimized linear prediction coefficients are computed directly from a system difference equation without converting the coefficients into the root-domain.

Method And Apparatus For Gradient-Descent Based Window Optimization For Linear Prediction Analysis

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US Patent:
7231344, Jun 12, 2007
Filed:
Oct 29, 2002
Appl. No.:
10/282966
Inventors:
Wai C. Chu - San Jose CA, US
Assignee:
NTT DoCoMo, Inc. - Tokyo
International Classification:
G10L 19/00
G10L 19/14
US Classification:
704219, 704211
Abstract:
The shape of windows used during linear predictive analysis can be optimized through the use of gradient-descent based window optimization procedures. Window optimization may be achieved fairly precisely through the use of a primary optimization procedure, or less precisely through the use of an alternate optimization procedure. Both optimization procedures use the principle of gradient-descent to find a window sequence that will either minimize the prediction error energy or maximize the segmental prediction gain. However, the primary optimization procedure uses a Levinson-Durbin based algorithm to determine the gradient while the alternate optimization procedure uses an estimate of the gradient based on the basic definition of a derivative. These optimization procedures can be implemented as computer readable software code. Additionally, the optimization procedures may be implemented in a window optimization device which generally includes a window optimization unit and may also include an interface unit.

Optimized Windows And Methods Therefore For Gradient-Descent Based Window Optimization For Linear Prediction Analysis In The Itu-T G.723.1 Speech Coding Standard

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US Patent:
7389226, Jun 17, 2008
Filed:
Dec 17, 2002
Appl. No.:
10/322909
Inventors:
Wai C. Chu - San Jose CA, US
Assignee:
NTT Docomo, Inc. - Tokyo
International Classification:
G10L 19/14
US Classification:
704211, 704219, 704224
Abstract:
Primary and alternate optimization procedures are used to improve the ITU-T G. 723. 1 speech coding standard (the “Standard”) by replacing the Hamming window of the Standard with an optimized window, with two windows, or with two windows and an additional performance of an autocorrelation method. When two windows replace the Hamming window, at least one of which is an optimized window, generally the first is used to determine optimized unquantized LP coefficients which are used to define an optimized perceptual weighting filter, and the second is used to determine optimized unquantized LP coefficients which are used to determine optimized synthesis coefficients. Optimized windows created using the primary and alternate optimization procedures and used in the Standard yield improvements in the objective and subjective quality of synthesized speech produced by the Standard. The improved Standard, methods, and window can all be implemented as computer readable software code.

Energy-Based Nonuniform Time-Scale Modification Of Audio Signals

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US Patent:
7426470, Sep 16, 2008
Filed:
Oct 3, 2002
Appl. No.:
10/264042
Inventors:
Wai C. Chu - San Jose CA, US
Khosrow Lashkari - Fremont CA, US
Assignee:
NTT Docomo, Inc. - Tokyo
International Classification:
G10L 21/04
US Classification:
704503, 704500, 370521
Abstract:
A method for energy based, non-uniform time-scale compression of audio signals includes receiving a frame of data corresponding to an input audio signal and segmenting the data into a plurality of segments. The method further includes estimating a value related to energy of the frame of data, determining a peak energy estimate for the frame, determining an energy threshold based on the peak energy estimate of the frame and comparing the value related to energy of the frame of the data with the energy threshold to control time-scale compression of the audio data.

Optimized Windows And Methods Therefore For Gradient-Descent Based Window Optimization For Linear Prediction Analysis In The Itu-T G.723.1 Speech Coding Standard

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US Patent:
7512534, Mar 31, 2009
Filed:
Nov 9, 2006
Appl. No.:
11/595415
Inventors:
Wai C. Chu - San Jose CA, US
Assignee:
NTT DoCoMo, Inc. - Tokyo
International Classification:
G10L 19/14
G10L 19/00
US Classification:
704211, 704219, 704224
Abstract:
Primary and alternate optimization procedures are used to improve the ITU-T G. 723. 1 speech coding standard (the “Standard”) by replacing the Hamming window of the Standard with an optimized window, with two windows, or with two windows and an additional performance of an autocorrelation method. When two windows replace the Hamming window, at least one of which is an optimized window, generally the first is used to determine optimized unquantized LP coefficients which are used to define an optimized perceptual weighting filter, and the second is used to determine optimized unquantized LP coefficients which are used to determine optimized synthesis coefficients. Optimized windows created using the primary and alternate optimization procedures and used in the Standard yield improvements in the objective and subjective quality of synthesized speech produced by the Standard. The improved Standard, methods, and widow can all be implemented as computer readable software code.

Illuminated Umbrella

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US Patent:
7571736, Aug 11, 2009
Filed:
Aug 22, 2008
Appl. No.:
12/197189
Inventors:
Wai Chuen Chu - San Mateo CA, US
International Classification:
A45B 3/04
US Classification:
135 16, 135 28, 135910, 362102
Abstract:
An umbrella or parasol having a plurality of LEDs (Light-Emitting Diodes) or other lightweight, energy conservative, light sources mounted proximate the distal ends of stretcher struts spreading and tensioning a ribbed umbrella canopy is described for both brightly illuminating the carrier and lighting an area surrounding the carrier on dark, rainy nights.

Method And Apparatus For Acclimating Aquatic Organisms To A New Environment

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US Patent:
8156898, Apr 17, 2012
Filed:
Nov 20, 2008
Appl. No.:
12/275130
Inventors:
Le Quan Luong - San Jose CA, US
Wai C. Chu - San Jose CA, US
International Classification:
A01K 63/02
US Classification:
119251
Abstract:
An apparatus for acclimating an aquatic organism, contained in a partially water filled plastic bag, to an environment in an aquarium includes an aquarium frame comprising a first portion exterior to the aquarium and a second portion interior to the aquarium. A bag holder is operable to hold a top of the plastic bag in an open position. The bag holder is positioned on the second portion where the top of the plastic bag is above a top level of water in the aquarium and a substantial portion of the plastic bag is below the top level. A dripping cup is operable to release water obtained from the aquarium into the plastic bag. The dripping cup is joinable to the first portion, whereby the aquatic organism is acclimated to a chemistry and temperature of the water in the aquarium.
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Wai Cheung Chu from San Jose, CA, age ~75 Get Report