I optimize AI models — LLM · TTS · ASR · voice conversion · speech enhancement — tearing models apart (quantization, SIMD, speculative decoding, pure-C rewrites) and building the serving around them so they run in production.
Preprints
- faster-enhancer.c: A Dependency-Free int8 Runtime for Streaming Speech Enhancement on Commodity CPUs Gyeongmin Kim. arXiv:2607.25350, Jul 2026. [arXiv] [code]
- Extracting Voice Styles from Frozen TTS Models via Gradient-Based Inverse Optimization Gyeongmin Kim. arXiv:2607.25351, Jul 2026. [arXiv] [code]
Under review
- Why One Small Fixed Tree Suffices: The Cost Geometry of Draft Trees for a Multi-Token-Prediction Drafter Gyeongmin Kim, Ayoung Moon, Seung Jin Lee. Under review, 2026.
- NC AI (Seongnam, South Korea) — Data Engineering Team (May 2026 – ) LLM inference optimization & serving — MoE quantization (W8A16), speculative decoding for a data-generation pipeline, and a distributed vLLM serving gateway in Go.
- Yonsei University Health System (YUHS) (Seoul, South Korea) — Research Engineer (Mar 2025 – Oct 2025) Led dev for NGS clinical report pipeline & SICU false-alarm monitoring desktop app.
- NCSOFT (Seongnam, South Korea) — Audio Data Team (Jul 2024 – Jan 2025) Built end-to-end audio post-processing automation for TTS data pipelines.
- Taiyaki Studios (USA, Remote) — AI Team (Jan 2023 – Jul 2023) Built a complete TTS training toolkit and production inference pipeline.
Model Optimization (Nov 2024 – present) — speech models re-implemented in dependency-free pure C, running in real time on-device
- nemotron-asr-streaming.c — 0.6B streaming ASR (FastConformer + RNN-T). Cache-aware streaming, W8A8 quantization with custom "Q8P" 4-row tile packing, NEON/AVX2 SIMD, up to 16 threads. [docs] [quantized model]
- LILAC — Zero-shot real-time voice conversion from a 3s reference (OpenVoice v2 port). Streaming HiFi-GAN decoder, 2-thread SPSC audio pipeline, RNNoise SIMD. RTF 0.7–0.8 on CPU, 270–330 ms end-to-end. [optimizations]
- MossTTS-Nano.c — 100M TTS model. NEON/SSE SIMD, KV cache, pthread parallelism — 30× speedup (68s → 2.3s), 1.8× faster than PyTorch CPU, RTF 0.33. [optimizations]
- DeepFilterNet3.c.wasm — Noise-reduction model in pure C/WASM, real-time in mobile browsers. ~1 ms/frame on MacBook M2, ~4 ms on Galaxy S23. [optimizations]
Axcellworks (JP) — real-time voice conversion intelligibility, remote collaboration (Nov 2023 – Feb 2024)
- Diagnosed chunk-boundary artifacts as receptive-field truncation; removed them with overlap-save chunk inference (neighbor-chunk context, keep center) at no added latency.
Multilingual TTS (Oct 2022 – Feb 2025)
- Data — BGM removal (Kim Vocal) → speaker diarization (pyannote) → VAD segmentation → Whisper transcription: ~30k clips (3–10 s).
- Models — VITS derivatives: JA2ML-VITS (19-language speech from Japanese-only data), JK-VITS (KO/JA bilingual), RVC-VITS (RVC-converted training data).
- Services — ProsekaTTS (2.3M+ visitors, 60 developer duplicates, Jul 2026) · ShirokoTTS (EN/KO/JA).
G2P Packages (Jun 2023 – Dec 2023)
- g2pk3 — Korean/Japanese/English → Korean pronunciation. [PyPI]
- ko2kana — Korean/English pronunciation → Katakana. [PyPI]
Japanese Translation Tools (Dec 2020 – Apr 2022)
- novel-reader — Android app translating novels from 7 Japanese sites with a proper-noun dictionary system.
- EhndWebTranslate — Async Japanese web page translator with real-time/document/novel modes.
- UserDict4Papago — Proper-noun dictionary overlay for Papago KR-JP translation.
Founded El Nino (university startup club → sole proprietorship) and built Knoc, a real-time translation subtitle service for classes and conferences — launched Mar 2026, covered by Multilingual.com.
- Rewrote the Python prototype in Go for large-scale WebSocket handling; Redis Pub/Sub subtitle rooms, distributed architecture, user/admin dashboards with PAYG & subscription billing.
- Knoc-Overlay desktop subtitle overlay (Electron) · elnino.kr website.
- Selected for MOE U300+ student startup track (2024) · served Konkuk Univ. winter school & KSRT conference.
- Hanyang University, Seoul, South Korea — B.S. in Computer Science (Mar 2023 – Present, Leave of Absence since Jul 2024)