Youngwoo Kim

Sep 2021 - Oct 2023ResearcherWork Experience

Underwood Computational Neuroscience Laboratory

Institute of Human Complexity and Systems Science (HCSS), Yonsei University

Seoul, South Korea 🇰🇷

• [Research] Developed an image data preprocessor for diffusion MRI scans (DICOM, NIfTI), which included algorithms to approximate diffusion tensors for each MRI voxel using Least-Squares Fit and Gradient Descent methods. Contributed in development of high-order solvers for human brain white matter deterministic tractography. #c++#matlab#python
• [Server Software Mgmt.] Managed laboratory servers for large-scale calculation. Enforced security by configuring firewall policies to limit IP sources and automatically ban clients with repeated SSH authentication attempt failures. Set up Slurm Workload Manager for managing batch job submissions from multiple users, and to balance load across all compute nodes. #linux#bash_scripting
[DevOps] Oversaw all code version control operations using Git: managed forked repositories, approved PRs, and resolved merge conflicts. While managing forked repositories, periodically checked upstream repo for new commits and merged the updates to the downstream repo, resolving any merge conflicts that occurred by communicating with the researcher in charge of the affected module. Also led periodic lab-wide meetings to consolidate downstream changes and create PRs, and then collaborated with upstream repo admins to merge the PRs to the upstream repo. #git#github#gitlab
[Networking Mgmt.] Configured network switches to create subnets for better firewall policy management. One subnet consisted of 5 workstations and a NAS for storing research data, and another consisted of security cameras and a NAS for storing security footage. Also configured router port-forwarding and firewall rules to allow remote access from trusted sources.
[Server H/W Mgmt.] Managed regular maintenance and replacement of server equipments including workstations, NVIDA GPUs, and Uninterruptible Power Supplies(UPS).
Advisor: Dr. Sehun Chun (Assistant Professor of Applied Mathematics, Integrated Science and Engineering Division, Yonsei University)

Jun 2023 - Aug 2023Postbachelorette AppointeeWork Experience

Mathematics and Computer Science Division

Argonne National Laboratory

Lemont, IL, USA 🇺🇸

• [Reserach] Developed an algorithm for processing raw brain diffusion MRI scan data for brain white matter tractography. Implemented parallel processing capabilities on certain functions using MPI, and tested them on large clustered systems with distributed memory. Increased algorithm accuracy by 15%, and improved execution time up to 40% compared to serial processing.#c++#mpi
• [Collaboration] Participated in daily lab meetings for progress reports and future planning. Visualized test results using MATLAB to plot accuracy and execution times. Shared insights on algorithm optimization techniques to improve execution times (e.g. quasi-Newton methods for gradient descent problems). #matlab
[Teamwork] Worked closely and formed close relationships with supervisors, researchers, and students from various cultural/educational backgrounds (U.S., Canada, India, Taiwan, Italy, Greece, UK, S. Korea etc.). In addition to daily lab meetings, participated in after-hours study sessions with fellow interns every weekend for studying related theories and research papers.

Mar 2022 - Apr 2023Chief Technology OfficerWork Experience

Development

Facade Inc.

• CTO and lead backend developer in developing a web platform,Sigmate,that provided investment information on NFTs and blockchains. Funded byRepublic of Korea Ministry of SMEs and Startups.
• [Development-Overview] Implemented a REST API server that were dockerized and deployed on AWS EC2 instances. Features included OAuth login stategies, JWT authentication, wiki content auditing/version control, and data fetching/caching from blockchains and SNS platforms. Modeled MYSQL, and Document (NoSQL) DBs for data storage, and AWS S3 bucket for static file hosting. #nodejs#typescript#docker#aws#mysql#nosql#redis
[System Design] Designed and deployed a web server architecture on Amazon Web Services (AWS) to ensure service continuity, and enforce security. Achieved less than 1% service downtime after official launch for a year, with 125 active users and average 5.2K API calls per day. Detected and mitigated average 1.2K malicious requests per day (SSH access, SQL injection and XSR attempts). (Click here to view system architecture diagram) #aws#aws-ec2#aws-rds#aws-dynamo-db#aws-s3#aws-cloudwatch#aws-route-53#ssl-tls#aws-certificate-manager#aws-vpc
[Development-SQL] Modeled a relational database with MYSQL and deployed it on AWS RDS. 52 SQL tables were created to support application features such as user authentication, rewards system, blockchain and SNS data aggregation, NFT minting event schedule tracking, wiki content moderation and much more. Made necessary table alters such as constraints and indexes to improve query performance after log analysis.#mysql#aws-rds
[Development-NoSQL] Implemented a NoSQL database for storing wiki content and edit logs. Implemented hash key(partition key) and range key(sort key) generation algorithms for DB entries to optimize speed and traffic for frequent select queries and support sharding to limit partition sizes.#nosql#aws-dynamo-db
[Development-Wiki Engine] Developed a wiki engine with version control and content verification. Version control supported version history comparison (diff), rollback feature for moderators and reward system for content contributors. Content verification features allowed readers to vote on certain sections of the wiki article to express their opinions on whether the article content was accurate or not.#typescript#mysql#nosql
[Development-Logging] Designed a custom logging system for analytics and debugging purposes. Collaborated with PMs and designers to implement loggers that collected information on peak activity time periods, user join rates, client device information and more to improve UX, evaluate marketing operation results, and make tweaks to UI elements. Collected debugging information such as API response times and error rates, and set up monitoring on AWS CloudWatch that automatically alerted developers on increased error rates, or critical database failures using email and Slack Integration.#typescript#aws-cloudwatch

Mar 2021 - Dec 2021Frontend MentorClub Activity

Web Frontend Development

CEOS

• Taught select new members of the club (around 10-15 members), who had little or no knowledge in web front end programming, how to use the React JS framework to develop a responsive single-page application(SPA) service.
• Increased the skill level of web programming of new club members so that they were able to develop a fully functional prototype over a course of 1-2 months, working in a team of developers, designers, and planners

Feb 2019 - Dec 2020Staff Sergeant / Language SpecialistMilitary Service

ROKAF SSgt

R.O.K. - U.S. Combined Forces Command

USAG Yongsan-Casey, South Korea

• [Language Abilities] Simultaneous/sequential English→Korean and Korean→English interpretation without script on a daily basis, participating in 2-3 meetings every day that each lasted 1-2 hours. Meeting interpretation on site, over phone and over video conference calls in the presence of colonel(O-6) - major general(O-8) ranking officers from various units subordinate to United States Forces Korea(USFK) and Republic of Korea Armed Forces.
• [Language Abilities] Translation of military analysis reports, report slides/scripts and meeting minutes in both English and Korean. Translated around 500-1000 words of text per day on average, and reported to Republic of Korea (ROK) and US officers.
[Driving Change] Developed a program using MS Excel that automatically generates reports based on data received from military defense systems. Started the development after feeling that too much time was being wasted on writing and translating reports during crisis responses. Persuaded ROK and US solidiers and officers to try out the program in a mock training session, and reported the improved response times to get approval to use the program. Improved work efficiency allowed the original hourly situation reports to be created every 20 minutes, and received a certificate from a ROK major-general ranking officer.

Mar 2018 - Feb 2019Vice Chief Residential AssistantWork Experience

Yonsei Residential College

Yonsei University

• Developed and implemented a web app, YREMS, that allowed over 340 students to sign up for house activities and provided student information/cancellation/attendance administration features for RAs. Front end development in HTML, CSS and Javascript. Featured responsive web design and back end database processing server in PHP and MYSQL. Frequently updated website based on student and RA feedbacks. #html#css#vanilla-js#jquery#php#mysql
• Responsible for 29 first year college students and provided continuous one-on-one counseling upon request for 14 of them for troubles or conflicts between house residents from various educational and cultural backgrounds, and adjusting to college life.
Managed over 12 million KRW of budget per semester dedicated for residential house programs and residents
Planned, managed, and ran residential house programs targeted to over 340 students with various educational and cultural backgrounds
Participated actively in weekly meetings where decision-making process involved reaching consensus of 10 fellow RAs and 1 Residential Master (Professor) from 4 different countries, who each has education experience in a different country.
Organized a house program “Coding Zellers” to teach Python. Went from basic grammar to web crawling, natural language processing and machine learning. Received successful programming assignment builds from all students, where 31 out of 39 students submitted without any kind of aid from instructor.
Supervised work distribution on house programs and dormitory duties among fellow 10 RAs
Established extensive timeline and cue sheets for each house programs, each with over 30 staff members and over 300 attending students