About Me


Who is CCJ ? Curriculum Vitae Education at AAU


www.kom.auc.dk

During my education as "M.Sc.E.E signalprocessing with specialization in acoustics", I have experienced the process of working problem oriented in project groups. On the engineering education at AAU, every semester has a specific theme and the students work together in groups of 4-7 members on a project revolving around this theme. The project work is documented in a report, which is evaluated during an oral examination where the entire project group participate.



I have participated in the projects that are enlisted below.

1. semester Theme: ''Reality and Models''
Project title: Loudspeaker Enclosure Simulation
On this semester, the project I worked on was to analyze a loudspeaker enclosure simulator program called LSPcad Lite.
During this project, focus was on investigation of the principle behind acoustical transducers and loudspeaker systems. This revolved around modelling electroacoustic loudspeakers, both in an infinite baffle and in a conventional sealed enclosure. Furthermore, different enclosure types were investigated.

 

2. semester Theme: ''Reality of Models''
Project title: Steering of a DC Motor
This project was focused on the modelling of a DC motor attached to a robotic arm. Doing this modelling and simulating the model using MATLAB, the robotic arm movements were investigated, with the purpose of understanding basic transduction principles between the elctrical and and mechanical domain. This project involved Laplace transformation and LTI system modelleing.
 

 

3. semester Theme: ''Analog and Digital Electronics''
Project title: Optical Detection and Counting
During this semester, extensive courses in analog and digital electronics were given. The project I worked on was the design and implementation of an optical detector with the purpose of detecting and counting objects, passing through a specific area. This involved transistor and operational amplifier couplings, use of a LED and a optoelectric diode / transistor, a 555 timer and a counter.

 

 

4. semester Theme: ''Microprocessors''
Project title: ECG Registration & Monitoring
The project I worked on was the design and implementation of an ECG-monitor, by using a PC for display and a microprocessor for processing of the data from the analog units. This involved assembler programming of a Motorola (68000) microprocessor, C programming of a user interface and a RS232C interface between the microprocessor board and the PC and construction of analog electronics for picking up the ECG. The project in pdf format can be downloaded here.

 

5. semester Theme: ''System Design / Construction''
Project title: ''Ship Collision Detection''
On this semester, the project I worked on was the design and implementation of an Ship Collision Detector, based on the GPS-communication and use of an VHF-radio. Design of a realtime algorith and GUI was made using C and JAVA. During this project, object oriented programming and design was used for the JAVA program, and the C program was designed using "Structured Program Development". Furthermore the project involved reading extensive protocols and implementation of a Intel 8051 microcontroller and additional software for picking up the data frames. Report in pdf format

 

6. semester Theme: ''Signal Processing Systems''
Project title: Digital & Analog Guitar Effects
On this semester, the project I worked on was the design and implementation of guitar effects, by use of analog electronics a three band equalizer and a distortion effect was made, and a DSP for processing of digital effects like reverb, compressor and flanger. Ofcourse all programs were made in assembler language for the used DSP (TMS320C26). Click here to download the report in pdf format.

By clicking the links beneath, you can see pictures of the system.

  • Codec: Implementation of the CS4218 from Crystal.
  • DSP: Implementation of TMS320C26 from Texas Instruments.
  • Distortion: Implementation of the distortion effect.
  • Input stage: The shielded input stage for the DSP.
  • The system: Rack & guitar.

Beneath, you can find samples of the guitar effects

Distortion Equalizer Flanger Compressor Reverb
"soft clipping" 12 dB bass boost 1Hz period "low" "short"
"hard clipping" 12 dB midrange boost 0.6Hz period "medium" "medium"
"asymmetrical clipping" 12 dB tweeter boost 0.38Hz period "high" "long"

7. semester Theme: ''Adaptive Systems''
Project title: Bandwidth Expansion in Speech Coders
The project I worked on was the design and implementation of a bandwidth expansion system of an existing telephone signal. For this project we used linear predictive coding, codebook generating and seach, mel frequency cepstral coefficients and auditory scales (Bark & Mel), line spectral frequencies, homomorphic deconvolution.
No report was written, but a scientific paper and a poster was made.

 

8. semester Theme: ''Adaptive Filtering Applied to Signals of Acoustic Origin''
Project title: Equalization of Room & Loudspeaker System
This project involved a variety of different signal processing tools, such as inverse filtering & deconvolution, design of elliptical, Chebychew and Butterworth IIR filters, adaptive LMS algorithm, polyphase filtering, upsampling and downsampling. Furthermore, knowledge about room acoustics, perception of sound, auditory scales, loudspeaker principles and loudspeaker system constructions was obtained in order to have the nescessary background knowledge. Besides, different adaptive algorithms, such as RLS, normalized LMS and the affine projection algorithm was investigated with the purpose of choosing the most suited one. The system was implemented on a DSP from Texas Instruments (TMS320C50) using assembler programming.
The project report can be downloaded here.

 

9. semester Theme: ''Acoustic Perception''
Project title: Crosstalk Cancellation For Playback of Binaural Recordings
During this project I obtained knowledge about binaural signals, perception, processing of binaural signals and playback of these. Furthermore, several measurements were performed both inside an anechoic environment and a listening room.
An investigation of the different crosstalk cancellation schemes: Atal-Schroeder crosstalk cancellation, Shuffler crosstalk cancellation and the recursive crosstalk cancellation was made in order to choose the optimal solution.
The choice of bandwith in which to perform the crosstalk cancellation was made on an investigation of the basic principle of crosstalk cancellation and the way humans perceive sound (especially localization)
The project report can be downloaded here.

 

10. semester Theme: ''Acoustics''
Project title: Evaluation of Filter Topologies Utilized in Passive Loudspeaker Systems
My master thesis was based on my own project proposal and revolved around an investigation of series / parallel filter solution and the hypothesis was that series filter solutions in certain situations had a superior sonic quality.
Enclosures for a three way loudspeaker system (right and left channel) was made and three different filters were made: A solution using series filtering, a solution using parallel filters and a hybrid filter solution (using both parallel and series filtering) was made.
The project work involved electrical circuit modelling, infinte baffle measurements of THD, impedance and acoustical magnitude transfer functions, Thiele-Small parameter calculation and lumped parameter modelling, measurements of response inside a listening room and an anechoic chamber etc.
These three filter solutions were tested by use of both an subjective (listening test) and measurements. The serial and the parallel filter solution both had a constant amplitude response, but the listening test indicated that the serial filter solution was superior.
Feel free to send me an e-mail if you are interested in downloading the master thesis (263 pages).



Courses
During each semester, there is a certain amount of courses that must be passed at an individual written or oral exam (SE-courses). Click the link to read a thorough description of the course content.

Semester   Course Title
1  Matematik 1A, Datalogi.
2  Matematik, Fysik.
3  Kredsløbsteori 1, Kredsløbsteori 2,  Matematik 1.
4  Matematik 2, Elektromagnetisme og Feltteori.
5  Tilbagekoblingsteori 2, Signalbehandling, Modulationsteori.
6  Sandsynlighedsregning, Statistik 1, Stokastiske Processer 1, Numeriske Metoder, Virksomhedsledelse.
7  Lineær Algebra, Systemidentifikation, Statistik 2, Stokastiske Processer 2.
8  Fundamentals of Acoustics, Acoustical Transducers Joint Time-Frequency Analysis, Engineering Responsibilities, Inverse Filtering and Deconvolution.
9  Architectural Acoustics, Acoustic Noise, Human Sound Perception and Psychometry.
10  No courses scheduled.

Besides the SE courses, PE courses related to the theme of the semester, are scheduled. These are enlisted below:

Semester

  Course Title
1 No courses scheduled.
2 No courses scheduled.
3 Analog Elektronik, Basal Digitalteknik, Tilbagekoblingsteori, Måleteknik.
4 Metoder for Systemkonstruktion, Systemarkitektur og -Integration, C Programmering, Algoritmer og Datastrukturer.
5 EMC, Multiprogrammering, Sandtidssystemer, Objektorienteret Analyse og Design, Objektorienteret Programmering med JAVA, Netværk og Datakommunikation.
6 Analoge Filtre, Signalers Oprindelse og Registrering, Analog og Digital Regneteknik, Realisation af Signalbehandlingssystemer.
7 Videnskabelig Arbejdsmetode og -Kommunikation, Avancerede Netværk,  Signalanalyse og -detektion, Algoritmers Repræsentation og Nøjagtighed.
8 Digital Audio, Acoustical Measurement Technique, Adaptive Systems, Heterogeneous Signal Processing Systems.
9  Auralisation and Virtual Reality Sound, Biostatistics, Audio engineering.
10 No courses scheduled.