collaborators

7 papers

cs.CL2026

Solar Open 2 Technical Report

Sungrae Park, Sanghoon Kim, Gyoungjin Gim +50

We present Solar Open 2, a 250B-A15B Mixture-of-Experts language model built for long-horizon agentic tasks, scaled up from Solar Open 1 (Solar Open 100B). To hold entire agent tra…

cs.LG2026

Multi-Step Likelihood-Ratio Correction for Reinforcement Learning with Verifiable Rewards

Deokgyu Yoon, Hyungkyu Kang, Joongkyu Lee +4

Reinforcement learning with verifiable rewards (RLVR) plays a pivotal role in improving the reasoning ability of large language models. However, widely used PPO surrogate objective…

cs.LG2026

MIDUS: Memory-Infused Depth Up-Scaling

Taero Kim, Hoyoon Byun, Youngjun Choi +2

Expanding pre-trained language models offers a practical way to increase capacity without training larger models from scratch. Depth Up-Scaling (DUS) does so by duplicating Transfo…

cs.CL2026

User-Oriented Multi-Turn Dialogue Generation with Tool Use at scale

Jungho Cho, Minbyul Jeong, Sungrae Park

The recent paradigm shift toward large reasoning models (LRMs) as autonomous agents has intensified the demand for sophisticated, multi-turn tool-use capabilities. Yet, existing da…

cs.CL2026

Solar Open Technical Report

Sungrae Park, Sanghoon Kim, Jungho Cho +34

We introduce Solar Open, a 102B-parameter bilingual Mixture-of-Experts language model for underserved languages. Solar Open demonstrates a systematic methodology for building compe…

cs.CL2025

ZERA: Zero-init Instruction Evolving Refinement Agent -- From Zero Instructions to Structured Prompts via Principle-based Optimization

Seungyoun Yi, Minsoo Khang, Sungrae Park

Automatic Prompt Optimization (APO) improves large language model (LLM) performance by refining prompts for specific tasks. However, prior APO methods typically focus only on user…