About

Jin Sam Cho (ValleyJin) standing by a lakeside in Korea
Daejeon · Korea

I'm Jin Sam Cho (ValleyJin) — an engineer and builder from Korea working where software meets business. My north star is simple: Coding + Business. Across two decades I've gone from national research labs to founding startups, and today I lead AI at K3I.

Launched

  • 2026 — Present

    Kyopo AI

    Solo · designed & builtkyopo.ai

    Multilingual batch document translation into 50+ languages, designed and built end-to-end. Translates Excel, Word, HWPX, PowerPoint, PDF, and Google Workspace files in one pass while keeping tables and layout intact (files up to 5 GB). Sentence-level caching cuts cost up to 80%, with glossary control and text-to-speech in 40+ languages.

Experience

  • 2026 — Present

    K3I Co., Ltd

    AX Leadk3i.co.kr

    Planning and building agentic AI applications, leading the company's AI transformation.

  • 2022 — 2025

    Tokamak Network

    Product Manager & UI/UX Plannertokamak.network

    Product and UX for decentralized applications on Ethereum / OP-stack Layer-2 infrastructure.

  • 2020 — Present

    OnTown Metaverse

    Founder & CEOOn.Town

    Built metaverse sites for startups and 10+ Technoparks.

  • 2017 — Present

    TechValue

    Cofounder & CEOtechvalue.co.kr

    Built TechValue, online startup-valuation software.

  • 2013 — 2015

    KAIST — Research Center for Future Strategy

    Senior Researcherkaist.ac.kr

    Built the Corporate Future Readiness Index (CFRI), a KAIST–JoongAng Ilbo joint project offering an alternative to conventional company valuation.

  • 2003 — 2013

    KAERI — Korea Atomic Energy Research Institute

    Senior Researcherkaeri.re.kr

    Project manager of Korea's first 100 MeV proton accelerator; ran regional tech-transfer cooperation programs and evaluated the economic benefit of developed technology.

Skills

01 AI & Network Science

  • Agentic AI applications on graph databases
  • Deep Persona application development

02 Simulation

  • ABM & Generative ABM (gABM)
  • Parallel computing in Python
  • 20+ yrs of technology-valuation Monte Carlo simulation

03 Web

  • React.js · Node.js
  • Java Spring framework

04 Blockchain

  • dApp development in Solidity

05 Foundations

  • Bankruptcy forecasting with AI (CNN & GANN)
  • Advanced computer science

Education

  • KAIST — Ph.D. Candidate, Graduate Program for Futures Strategy2016 — Present
  • KAIST — M.S., Graduate Program for Futures Strategy2013 — 2016
  • Kyungpook National University — Ph.D. Candidate, Business Administration2009 — 2012
  • Kyungpook National University — M.A., Business Administration1998 — 2003
  • Kyungpook National University — B.A., Business Administration1990 — 1998

Recognition

36Published articles
2Books authored
10+Korean patents
  • 2005

    Minister's Commendation

    Ministry of Trade, Industry & Energy

    Awarded for contribution to Korea's 100 MeV proton accelerator development and to radioactive-waste facility site selection.

  • 2003

    MBC Campus Music Festival — Grand Prize

    Composerlisten

    Awarded the grand prize as composer of the winning song.

Also: 10+ Korean patents (AI — bankruptcy forecasting with CNN & GANN; blockchain — contribution proof via smart contracts), bilingual in Korean and English, and a certified TCB analyst (Korea Technology Finance Corporation).

This site

A working journal. Posts are written in the open and the homepage stays in sync with my GitHub activity automatically. Find me on GitHub, Medium, and X.