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- Name: Jiyong Youn (윤지용)
- Nickname: HLETRD
- Contacts
- GitHub Email
- I do not usually check comments on this site. Please contact me by Email.
- Language
- Works
- Server Developer, Puzzle Monsters Inc. (2024. 04. -)
- System Engineer, Perigee Aerospace Inc. (2023. 11. – 2024. 04.)
- Educations
- Ph.D. candidate in Electrical and Computer Engineering, Seoul National University (2020 -)
- B.S. in Electrical and Computer Engineering, Seoul National University (2020)
- Graduated Gyeonggi Science High School (2016)
Hobbies
Motorcycle (2018-)
- 2019 KTM 390 DUKE (2021.02. -)
- 2017 Honda CB650F (2019.05. – 2021.02.)
- 2016 Yamaha MT-03 (2019.02. – 2019.05.)
- 2018 Honda Super Cub (2018.09. – 2019.02.)
Photography (2013-)
Astrophotography (2016-)
Equipments
Photography
- Sony A7R V
- Panasonic Lumix DMC-LX10
- Sony Cyber-shot DSC-HX99
- Sigma 24-70mm f/2.8 DG DN Art
- Sony FE 100-400mm f/4.5–5.6 GM OSS
- Sony FE Carl Zeiss Sonnar T* 55mm f/1.8 ZA
- Tamron SP 70-300mm f/4-5.6 Di VC USD
- Samyang 14mm f/2.8 ED AS IF UMC
- Samyang AF 35mm f/2.8 FE
- Samyang 85mm f/1.4 AS IF UMC
- Samyang 135mm f/2.0 ED UMC
- Canon EF 50mm f/1.8 STM
Sony A7 IISony A5000Sony Alpha SLT-A65Sony 18-55mm f/3.5-5.6 DT SAMSony FE 28-70mm f/3.5-5.6 OSSMinolta AF 70-210mm f/4Canon EF 200mm f/2.8 L USM II
Astrophotography
- QHY16200A
- QHY5L-II Mono
- Takahashi FSQ-106ED
- CRUX-170HD
Skills & Works
Hardwares
- From designing to manufacturing of electrical circuits, including PCB designing, and programming of embedded microcontrollers/FPGA.
- Experiences in STM32, FPGAs, ESP32, ESP8266 microcontrollers, AVRs, Arduinos, …
- PCB EDA: Prefer Altium Designer, EasyEDA as an EDA tool.
- 3D CAD/CAM: Prefer SolidWorks and Autodesk Fusion 360 for 3D product design and Autodesk AutoCAD for 2D design.
- Raspberry Pi
- Low performance and (relatively) low durability(compared to Cortex-M/R based controllers), but…it’s just cheap!
- Outsourced projects…
- Developed NanoFocus, an electronic focuser controller for astrophotography.
- Developed focusing system & filter control system for SNU CEOU 24inch telescope
Softwares
Python 2/3 (2015-)
- Also skilled in various frameworks. (Flask, Django, Numpy, Scipy, PyQt5, AstroPy …)
- Miscellaneous works are on my GitHub
- Intranet website based on Python 3, Django
- Spectral analysis tools for astronomy, based on Python and AstroPy.
- Website providing personalized stats & records of Jubeat Festo.
- Based on Python 2, Flask, MongoDB
- 500+ users
- Website providing personalized stats & records of Jubeat Clan.
- Based on Python 2, Flask, MongoDB
- 300+ users
- Website providing personalized stats & records of Jubeat Qubell.
- Based on Python 2, Flask, MongoDB
- 1000+ users
- Based on Python 3, Astropy, Numpy,
- Various scripts for processing observational data for astrophotography as well as astrophotometry.
Others
- Outsources projects. Below are projects done in 2019.
ARM Cortex M (2018-)
Golang (2021-)
- A forked Go-Ethereum client to support local replay of the entire blockchain.
C# (2017-)
NanoFocus ASCOM drivers
NanoFocus PC console
Outsourced projects
PHP5, PHP7, PHP8 (2014-)
- Automated weather monitor for SNU Astronomical Observatory
- Website provides personalized stats & records of Dance Dance Revolution.
- 200+ users
- Based on PHP, MySQL
- Fully encrypted file storage.
- Based on PHP, MySQL
- API providing water temperature of rivers in Korea.
RFLP Designer Demo
Java/Kotlin/Android (2014-)
- Make your Android phone to be used as a tablet(input device.)
- PC client is based on Visual Basic 6
Outsourced projects
Javascript (2013-)
- Developed front-end, using React
- DB dump & analysis tool for Ethereum blockchain
- Based on HTML5 + Javascript
- Awkward…
- Simple tool to memorize words fastly
- IME-independant typing tutor application, running in browser.
- Source code
- Based on Pebble.JS SDK
- Simple app displaying water temperature of nearest river, with KOSPI/KOSDAQ informations.
GPU computing (2015-)
- Moderately skilled in CUDA, OpenCL
- To practice CUDA…
- Found a lowest SHA1 hash (probably):
00000000000000c06d2e8c36f247206a9a4b1c63
- Based on C + OpenCL + GTK+ + CFITSIO
- Very fast CCD data reduction with GPU computing
- Based on C + OpenCL/CUDA
- Now holding records for known MD5 extreme values.
- Max:
md5(0DbB^a2hxjdc_JiyongYoun-HLETRD) = fffffffffffffec29931c5489a14a02e
- Min:
md5(08ni(g0u3ada_JiyongYoun-HLETRD) = 00000000000000d4a49581c7f0638557
- Popcount max:
md5()to0wzR*x[L{WJ^y5G>B-HLETRD) = fb9fdfff13efffffffdfffe2efeffaff
- Popcount min:
md5(hhQ1/'jy5W^G[zwJ*RBL-HLETRD) = 0000098a020401801208448010004024
- Bytesum max:
md5(wWrC--3mn-a000000000-HLETRD) = fffae5f0faf8f9f5e6f0fafbf7f8e7f6
- Bytesum min:
md5(Gs4u^x4mn{4000000000-HLETRD) = 0405041602140309020a3c071702070a
- …and a few other languages not listed above…
- C(2010-), C++(2011-), especially for OpenCL, CUDA, and embedded systems(ARM Cortex-M, AVR)
- Assembly newbie (x86, AVR, ARM Thumb/Thumb-2)
- Visual Basic(2009-)… for XP-compatible applications…
- HTML5, CSS, JS (For web dev)
BrainFuck
Others
Had prefered CentOS/RHEL than Ubuntu
- But Ubuntu is more convenient now…
- Prefer Git as VCS.
- Prefer MariaDB along various RDBMSs.
- Prefer MongoDB and Firebase along many NoSQLs.
- Love Adobe CC products, especially Photoshop, Lightroom, Premiere, and Audition.
- Use PixInsight as post-processing tool for astrophotography.
- Participant, and gold medal winner of IBO 2014
- Feel free to contact me if you are past IBO participant.
- Use Visual Studio Code as the main text editor.