Transcript Digital Representation of Audio Information

Signal Processing and Us
Kevin D. Donohue
Databeam Professor
Electrical and Computer Engineering Department
University of Kentucky
Lexington, KY, USA
Engineering Raw Materials
 Energy
Thomas Alva Edison
Charles Proteus
Steinmetz
http://chem.ch.huji.ac.il/~eugeniik/history/steinmetz.html
http://sln.fi.edu/franklin/inventor/bell.html
 Information
Alexander Graham
Bell
Norbert Wiener
Claude Elwood
Shannon
http://en.wikipedia.org/wiki/Norbert_Wiener
http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Shannon.html
Signal Processing
 Modeling, Extracting, and Using
Information from Signals
 Radar Signal Processing
 Ultrasonic Non-Destructive Evaluation
 Medical Imaging and Signal Processing (Ultrasonic,
MRI, X-ray, SPECT)
 Senor system development for characterizing
animal behavior
 Image and Audio Signal Compression and
Processing
 Psychometrics (modeling/measuring human
response to visual and audio stimulus)
Ultrasonic NDE
Title: Nondestructive Inspection
Techniques for the 500N Fuel Tank
Supports.
Description: Perform ultrasonic and
thermal imaging on support contacts in a
new plastic gas tank design. Correlate
ultrasonic parameters with thermal
imaging features, and breaking force of
the imaged contact.
Ultrasonic NDE
Computer
Controlled
Instrumentation
Y-Direction
X-Direction
EVOH interface
Transducer
Water for
ultrasonic
propagation.
A-scan
path
Kiss
Area
EVOH interface
Ultrasonic NDE
Thickness Map
0.2
1.6
1.4
1.2
0.15
Inches
1
0.8
0.6
0.1
0.4
0.2
0
-0.2
0
0.2
0.4
0.6
0.8
Inches
1
1.2
1.4
0.05
Ultrasonic NDE
Ripple Map
0.02
1.6
0.015
1.4
0.01
1.2
0.005
Inches
1
0.8
0
0.6
-0.005
0.4
-0.01
0.2
-0.015
0
-0.2
0
0.2
0.4
0.6
0.8
Inches
1
1.2
1.4
-0.02
Signal (Information) Processing
Instrumentation
and Electronics
Probe event with
signal/energy
Measure
response/changes
Process
measurements to
extract information
Phenomenon or
Event
Physics,
Chemistry
and Math
Statistics,
Math,
Physics,
Computer
Present/send
information in
usable format
Math, Psychophysics,
Communications
Ultrasonic RF Signal
A-scan from liver tissue
Propagation
path
effects
0
Scatterer
Response
0
1
2
3
Microseconds
Pressure
Pressure
Imaging Pulse
0
0
50
100
Microseconds
150
Pressure
A-scan section from liver tissue
0
82
84
86
88
90
92
Microseconds
94
96
98
100
Examples of RF segments in Specular Analysis windows
In Situ and Invasive Ductal Carcinoma
600
8
400
7.5
7
0
MHz
rf amplitudes
200
-200
6.5
6
-400
5.5
-600
5
5
-800
0
0.5
1
1.5
mm
2
2.5
5.5
6
6.5
MHz
7
7.5
5.5
6
6.5
MHz
7
7.5
8
3
Dense Stromal Fibrosis
400
8
300
7.5
7
100
MHz
rf amplitudes
200
0
6.5
6
-100
5.5
-200
5
5
-300
0
0.5
1
1.5
mm
2
2.5
3
8
Classification Parameters (Interior)
Select ROI as Largest Rectangle
Inside Suspicious Mass
Subdivide ROI into Analysis
Windows (50% overlap)
Compute Regular Likelihood
Statistic in Each Analysis Window
Regular
Compute
Spacing and
Regular
Likelihood
Threshold
Test
Not
Compute PSD
Slope and
Center
Frequency
Compute Specular Likelihood
Statistic in each Analysis Window
Diffuse
Specular
Threshold
Test
Compute CA
Slope and
Specular
Likelihood
Class Support for Signal Processing
Circuits II (EE221)
Transfer functions (describes how circuits/systems change
signals from input to output)
Probability Theory (MA 321)
Models for variability and uncertainty, Foundations of
Statistics, Information, and Communication Theory
Signals and Systems I (EE421)
Frequency domain representations, Probability models for
noise, Signal interaction with systems/phenomena
Signals and Systems II (EE422)
Digital Signal Processing (DSP) models, Feedback and
Control Systems
Electives for Signal Processing
 Introduction to Communication Systems (EE 511)
 Digital Communication Systems (EE 512)
 Feedback Control Design (EE 571)
 Digital Control of Dynamic Systems (EE 572)




Introduction to Numerical Methods (MA 321)
Matrix Algebra and Its Applications (MA 322)
Methods of Applied Mathematics I (MA 432G)
Introduction to Complex Variable (MA 433G)
 Intro. Program Design, Abstraction, & Problem Solving (CS 215)
 Introduction to Software Engineering (CS 216)
 Algorithm Design and Analysis (CS 315)
 Introduction to Engineering Statistics (STA 381)
 Probability (STA 524)
 Introductory Statistical Inference (STA 525)
 Any of the computer engineering courses …
Microphone Array Processing
Use signals received over spatially
distributed microphones to identify and
locate the number of speakers in a room.
Microphone Array Processing
8 microphone outputs:
20 milliseconds from 2 Speakers
Steered
Response
Power
Processing
Resulting Acoustic Image for
Sound Source Location
Example Listings
• Title: Research Engineer - Interactive Audio Technology Skills:
This position is in the Research Division of Dolby Laboratories and
involves the creation of innovative audio signal processing
technologies from conception to proof of concept. The position offers
the possibility of working in cooperation with other technology
developers and researchers, as well as the opportunity to develop and
propose independent ideas for further investigation.
Dolby Laboratories is looking for a self-motivated, highly talented
individual with in-depth understanding of the way the audio is
designed, mixed, and/or rendered for gaming or other interactive
entertainment applications. Work will be performed in a small
collaborative team environment involving interaction with internal
groups and external users of the target technology.
Example Listings
• Requirements:
PhD or MS in electrical engineering .
Proficient in digital signal processing theory.
Proficient in C language programming.
Proficient and experienced in the fundamentals of digital audio
processing.
Expertise in a minimum of two or more of the following:
- speech, audio, or video bit-rate reduction technology
- psychoacoustics
- C++ or Matlab programming
- DSP implementation issues, such as word length issues,
MIPS/memory constraints, and so on
- software development team experience including software version
control
- technical writing and presentations
Excellent communication skills.
Team-oriented work ethic.
Interest or experience in music and/or high-fidelity sound.
Strong interest in learning new technologies.
Example Listings
•
Title: Signal/Image Processing Research Engineer Skills: Research, Engineer ,
performance, analysis, systems, computer, algorithms, data analysis, Physics,
Engineering , simulation, security, system, MATLAB, C
•
Job Description:
Assists in the design and performance analysis of radar, electro-optical, communications
or biological detection systems. Implements computer simulations for predicting the
performance of such systems and of advanced signal processing algorithms. Plots and
analyzes simulated or measured data. Assists in data analysis, and in the preparation and
presentation of technical briefings and reports.
Education:
Bachelors degree in Physics, Engineering , Mathematics, or similar
discipline required. Advanced degree is preferred.
Required Skills:
Requires a minimum of 1+ years relevant experience., Experience with
computer simulation and signal or image processing. Must be a U.S.
Citizen and qualified to obtain security clearance.
Desired Skills:
A background in signal processing, image processing, statistical
detection theory , or system design, will be extremely useful.
Knowledge of MATLAB or C++ is also very desirable. The ability to
interact with customers and excellent writing skills.
Example Listings
•
Title: Signal Processing Engineer Skills: Engineer , algorithm, engineers ,
hardware, software, Engineering , Physics, MATLAB, programming
•
Job Description:
Signal processing engineer focused on algorithm design and support of
subsequent algortithm implementation in the areas of communications
and sensors. This position involves working with other signal
processing engineers, as well as hardware and software engineers , to
develop innovative concepts and then advance these concepts through
the technology prototype stage.
Education:
BS in Electrical Engineering , Physics or other technical field.
Required Skills:
2 or more years of experience in the singal processing field is
required, may include coursework and internships. Familiarity with the
MATLAB programming environment is expected. Specific experience with
the digital and analog communication techniques, adaptive filtering
and estimation is desirable.
Example Listings
•
Title: Signal Processing Engineer Skills: Engineer , algorithms, development, applications,
acoustic, analysis, Matlab, modeling, system, security, Engineering , foundation, mathematical,
software
•
Job Description:
Develop signal and image processing algorithms to support the development of a wide range of
applications. These applications require the processing of data generated by sensors in spectrums that
range from acoustic to X-Ray. The candidate will be responsible for developing techniques for object
detection, imaging, pattern matching, and pattern generation. The candidate will apply principles of
image processing, such as covariance analysis, Maximum likelihood estimation, Hough/Radon
Transforms, and Kalman filters for tracking. the candidate will work with sensors such as sonar,
radar, SAR, multi-static radar, visible and IR cameras. The candidate should also be facile with the
Matlab modeling system.
•
Education:
Masters Degree in Engineering or related discipline is required.
Required Skills:
Must have 6+ years of relevant experience. A thorough understanding of
image and signal processing techniques. A strong foundation in the
mathematical underpinnings of those techniques. The candidate should
be familiar with the Matlab modeling system. Ability to work
effectively with a team is required.
Desired Skills:
Capability to develop software in a real-time environment. A strong understanding of radar and SAR
processing techniques. Ability to interact and present technical information verbally and in writing
(briefings, presentations, training, etc) to internal and external customers. A PhD in Engineering and
2+ years of experience is
preferred.