This portfolio document summarizes Steve Kyonglok Yoon's background and experience. Some key points: - Over 18 years of experience as a software engineer specializing in C/C++ and with skills in other languages like ARM7 assembly, C#, Java, Python and Perl. - Educational background includes a degree from Hongik University and having published academic papers on topics like image processing and iris recognition. - Professional experience includes developing software solutions for digital TV technologies like DVB-H, DRM, and DAB. He has supported mass production for companies in areas like mobile, set-top boxes, and automotive infotainment. - Other experience includes Bluetooth application development,

1. Portfolio
Steve Kyonglok, Yoon (윤경록|尹景祿)
steveyoon77@gmail.com

2. WHO AM I
1. Enjoying the job
- Making enjoyable job environment.
- Picture shows an event during DAB field test
trip in EU.
2. Outside activity
- Making connections with people who interest
better work practices
- Picture was taken in a seminar for non-violent
communication.
3. Self-development
- Heavy reader for self-development.
- Books stacked twice than the picture
4. Co-working
- Making drastic co-working for a result.
- The white board shows how to discuss fiercely
for designing buffer control algorithm.
me
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3. CRAFTSMANSHIP
More than 18 years’ experience as a
software engineer.
• High level: C/C++,
Capable: ARM7 assembly,
C#/Java/Python/Perl
• Familiar with RTOS and embedded system.
• Make beautiful codes complying with KISS
and DRY principles
See my MPEG2-TS demux codes.

4. WHAT I’VE DONE (undergraduate)
1996
1998
2001
2004
2006
Admission to
Hongik University
Military service in
Korean Army
Graduated
Studied Image Processing as an
undergraduate student and
contributed to publish some
academic papers
Papers:
2003 Microsoft Certified Professional
for VC++ 6.0

5. Microsoft Certified Solution Developer for VC++ 6
• Passed below exams to be qualified Microsoft
Certified Solution Developer in 2003

6. Paper: A vision system for the inspection of
automobile fuse boxes
• Study of vision system that exhibits automatic
examination of the conditions of fuses and relay
boxes using a camera.
• Wrote a Windows demo application in VC++
adopting image processing algorithms.

7. Paper: A feature extraction method for binary iris
code construction
• Study of a feature extraction method for binary iris
code construction.
• Contributed to design algorithm to extract iris
region
• Wrote Windows demo application and test
application in VC++ adopting image processing
algorithms.

8. WHAT I’VE DONE (for companies)
2005 2015
2009 2010
Developed DVB-H
software solution
Developed DRM
software solution
Developed X-CAS
software solution
Developed DAB
software solution
Newport Media Inc. Alticast Inc. Telechips Inc.
Supported
consumer BT
HID
Broadcom Ltd.
(Mobile) DVB-H/DRM (STB) CAS (Auto) DAB
2016
Cypress Semi. Co.
Supported
consumer
WICED BT app
2018
Supported
automotive BT
controller F/W
2019 2021
Nordic Semiconductor
- Support LTE Cat-M1/NB-
IoT certification in LGU+,
- Implement GNSS
application(enhancing
location estimation using
Linear Kalman filter and
fusing Cellular/GNSS/INS)

9. Digital Video Broadcasting - Handheld
• Developed DVB-H software solution and
supported mass production
• Developed ESG(Electronic Service Guide)
• Developed FLUTE(File delivery over unidirectional
transport) protocol
• Developed SDP(Session Description Protocol)
• Integrated CAS(Conditional Access System) of
Nagravision, Irdeto and NDS
• Supported mass production of mobile TV phones
for Samsung and LG electronics in Italy, Philippines,
and Russia

10. Digital Rights Management
• Developed OMA BCAST DRM software solution and
supported mass production
• Designed the total solution architecture
• Developed Key manager
• Developed a descrambler of ISMACryp and IPSec
• Supported mass production of Samsung mobile TV
phones in France

11. Exchangeable Conditional Access System
• XCAS(Exchangeable Conditional Access System) is
a software solution for STB based on OMA(Open
Mobile Alliance) DRM(Digital Rights Management)
specifications
• Developed XCAS
• Developed a XCAS manager and bootloader on an
embedded Linux STB
• XCAS client: descrambler of encrypted contents
• XCAS manager: version control of XCAS client
• XCAS monitor: management of XCAS client’s status
• XCAS bootloader: launcher of XCAS client
• Supported mass production
• T-Broad MSO(Multiple System Operator), Korea
• C&M MSO, Korea

12. Digital Audio Broadcasting
• Development of a DAB solution
• Developed the FIC(Fast Information Channel)
protocol
• Developed the MPEG-2 TS decoder
• Developed MOT(Multimedia Object Transfer)
protocol
• Developed Slide Show manager
• Developed EPG(Electronic Program Guide)
• Developed service following function
• Developed seamless switching function between
DAB and FM services
• Developed Traffic Announcement function
• Supporting Mass Production (Car audio and AVN)
• Hyundai motor group, Korea
• GM OPEL, German
• Mitsubishi-motors, Japan

13. DAB PC player
• Wrote DAB PC player in VC++ using wxWidgets
• Visualized and played data transmitted via DAB air
streaming
• Contributed
• To design architecture
• To write a decoder of ETI stream file to avoid total
RF system and to simulate functionalities
• To write decoders for each protocol stack and to
design database of each data

14. Bluetooth HID application
• Supported LGE Bluetooth Classic/Low Energy Remote
Controller projects
• Solved problems in ROM(read-only memory) codes
• Solved problems in I2C and SPI device driver
• Wrote patch code using ARM cortex M3 assembly
language
• Wrote peripheral's device driver
• Developed specific features on HID application
requested by customer

15. Cypress WICED/MODUS application
• Supported Cypress community issues on Bluetooth
WICED/MODUS SDK
• Cypress WICED/MODUS SDK is software solution
including IDE for Bluetooth. It consists of IDE, some
sample application codes, BT stand alone protocol
stack and BT controller firmware patch binary
• Answered Cypress community issues
• Seminars for customers
• Solved BT stack (stand alone protocol stack)
problems

16. Bluetooth Controller Firmware
• Supported Tier 1(HKMC, GM, Renault) automotive
Bluetooth controller firmware issues
• Analyzed BT baseband and link management
protocol using BT air sniffer
• Solved problems in BT core scheduler, link manager
and resource manager in ROM codes
• Made patches using ARM cortex M3/M4 assembly
language
• Solved 61% of customer issues and rest of issues
were solved by two other team members
• Released 23 documents to customers and internal
team members. Its potion is 92% of documents
that released by team members

17. QT Bluetooth test application
• Maintained Bluetooth sample application
implemented in QT creator
• Added and fixed functions to test Bluetooth
features

18. Location estimation Fusing GNSS/Cellular
• Implementation using linear Kalman filter
• Test:
• Go through metropolitan area
• Go through underground highway
• Go through tunnels
• Blue point indicates the estimated location
• Red point indicates the GNSS measured location
• Yellow point indicates the Cellular measured location
• Conclusion:
• Single cell location has big error
• Linear Kalman filter and fusing GNSS/cellular locati-
on has limitation in its accuracy
• For further enhancement, need to use Unscented K-
alman filter and fusing GNSS/INS

19. Location estimation Fusing GNSS/IMU
Thingy:91 Development Kit (GPS + Accelerometer) nRF9160 Development Kit (GPS) + GY-85 IMU
(Gyroscope+Accelerometer+Geomagnetic sensor)
Telit Bravo Cellular IoT Evaluation Kit
(GPS+Gyroscope+Accelerometer+Geomagnetic sensor)
Assumptions:
• Match of between car heading and
X-axis of accelerometer
• The roll and yaw rotation is
insignificant
Implementation: after calculating
velocity by considering only pitch
rotation, it estimates the position using
linear Kalman filter
Result: The error of estimation is big
Kraft or
Madgwick
Rote zacc Subtract g UKF
zIMU zacc zGPS
q Wzacc Wa p, v, a
• I have been implementing an algorithm in M. Roobeek’s ‘Motion
tracking in field sports using GPS and IMU’ thesis (2022/10/14)
• Devices
• nRF9160 DK+GY-85 IMU
• Telit Bravo Cellular IoT EVK

20. Reboot today
Thank you for listening.
Hope we could make relationship for
sustainable businesses.