Xiyana Figuera
Contact

Engineering robots that understand what we mean and move with intent.

Robotics and AI researcher with 3+ years developing learning-based systems for embodied agents — reinforcement learning, imitation learning, and language-guided motion, taken from simulation to real humanoids. First-author at IROS 2024. Currently applying computer-vision and VLM systems to industrial automation at NTS Solutions.

CORE EXPERTISE
Embodied AI Reinforcement Learning (RLHF · PPO) Imitation Learning Motion Retargeting Computer Vision PyTorch
ALSO WORKED WITH
LLMs & VLMs Isaac Sim MuJoCo Unity Isaac Lab Hugging Face Stable-Baselines3
LANGUAGES
SpanishNative EnglishAdvanced · TOEFL 104 KoreanAdvanced · TOPIK 5
Available for Research Roles
Xiyana Figuera — professional profile photo
location_on Ulsan, South Korea
badge F-2-7 Visa

Research Projects

UNIST · AHRI LAB open_in_new
MR.HuBo · IROS 2024 · First Author

Redefining Data Pairing for Motion Retargeting Leveraging a Human Body Prior

IROS 2024 — the 40th IEEE/RSJ International Conference on Intelligent Robots and Systems, Abu Dhabi.

Data-driven motion retargeting is bottlenecked by the cost of human–robot pose data and the motion capture behind it. MR.HuBo inverts the pipeline: it samples robot poses straight from the robot's joint configuration space and exploits a human body prior (VPoser, a VAE) both as an inverse-kinematics solver — mapping each robot pose to a candidate human pose — and as a denoising filter that discards the infeasible ones, yielding 2 million clean pairs per robot with no motion capture. That enabled fully-supervised, end-to-end retargeting (a two-stage 6D-rotation network) where prior work was limited to unsupervised learning — scaling across three humanoids of different kinematics (Reachy, Coman, Nao), in real time on the real Reachy from a single RGB camera.

PyTorch VPoser MuJoCo PyBullet ROS2

A single human motion retargeted at once to three humanoids of different kinematics and size — Reachy, Coman, and Nao — with no motion-capture data behind any of them.

Deployed: Reachy Simulated: Coman · Nao
M.S. Thesis Core

RLHF Semantic Motion Refinement

tune

The core of my M.S. thesis, framed as an alignment problem for embodied agents. A robot can replicate a human's joint configuration exactly and still lose what the motion means: a retargeted "drinking" gesture that never reaches the mouth is kinematically correct but semantically wrong. I added a post-refinement stage where an agent learns per-joint adjustments for four key joints (shoulder, arm, forearm, wrist) via RLHF — a reward model trained on human-preference comparisons, optimized with PPO — recovering the semantic intent that pure kinematic retargeting discards. In a human survey, refined motions were consistently preferred over the un-refined baseline.

RLHF PPO Stable-Baselines3 Unity

Statistical significance confirmed (ANOVA + Tukey HSD)

Aligned with just 4 rounds of human feedback

menu_book Thesis
Schematic of the CLIP-style reward model: a Transformer motion encoder and a fine-tuned LLaMA language encoder map robot motion and a natural-language prompt into a shared embedding space, where their cosine similarity becomes the reward score — replacing costly human feedback.
2-Month Prototype

CLIP-Style Motion–Language Reward Model

hub

RLHF aligns motion to human intent, but human feedback is slow, costly, and doesn't scale — the bottleneck of my thesis. This prototype swaps the human evaluator for a learned one — RLAIF applied to robotics: a CLIP-style reward model that automatically scores how well a robot's motion matches the semantic intent of a natural-language description ("drinking motion", etc.), pairing a Transformer motion encoder with a fine-tuned LLaMA language encoder in a shared embedding space where cosine similarity becomes the reward. It turns a costly human-feedback reward model into a scalable, automatic one — the direction my thesis itself flagged as its missing piece.

CLIP-style Transformer LLaMA PyTorch Hugging Face Isaac Sim

Robot-motion & language embeddings aligned in a shared space to score semantic intent without human labels — replacing the human-feedback reward model in RLHF

Industry Projects

NTS SOLUTIONS
Object Detection + VLM OCR · On-Device

Legacy Equipment Video → Structured Manufacturing Data

precision_manufacturing

An end-to-end system that turns legacy-equipment HMI video into structured manufacturing data — with zero hardware modification. A YOLO/Ultralytics detection stack reads on-screen machine state, alarms, and buttons, while a vision-language model (Nanonets-OCR2-3B / Qwen2.5-VL) fine-tuned with 4-bit QLoRA reads lot IDs — lifting exact-match OCR from a 65.5% baseline to 100% on the held-out test set. I shipped it as a compiled, GPU-accelerated GUI app that runs fully on-device. Building the training dataset was a project in itself: dHash diverse-frame selection, targeted cropping, and an AI-assisted review loop that caught and corrected systematic OCR label noise.

Python PyTorch HuggingFace QLoRA YOLO OpenCV PyInstaller
100%
OCR exact-match (from 65.5%)
16 GB
Fully on-device · no cloud

Pipeline at a Glance

Detection · YOLO
machine state, alarms & buttons

OCR · VLM
lot IDs — Nanonets-OCR2-3B / Qwen2.5-VL · 4-bit QLoRA

On-device
16 GB VRAM · RTX 5070 Ti vs. DGX Spark (GB10) · no paid APIs

Detection + Classification · 11 Defect Classes

Semiconductor Wafer Defect Detection (AOI)

query_stats

An Automated Optical Inspection (AOI) pipeline for wafer-surface defects across 11 classes, lifting classification accuracy from a 66% baseline to 98.9% — 0% miss, 0.1% overkill — on a held-out evaluation set of ~1,000 images. I benchmarked three detection architectures (YOLOv8s, YOLOv11m, RT-DETR-L) with a custom detection-priority fitness function and per-class threshold optimization, and engineered the data workflow (Pascal-VOC→YOLO, K-fold cross-validation, class-merge/low-sample logic, duplicate/mislabel detection). A deep error investigation — a 10-category false-negative framework, ResNet50 + DBSCAN interclass-similarity clustering, and SAHI tiling — traced the remaining ceiling to labeling quality and localization, not classification.

PyTorch Ultralytics YOLO RT-DETR SAHI scikit-learn OpenCV
98.9%
Accuracy (from 66%)
0%
Miss rate · 0.1% overkill
CAREER

Experience

Bridging state-of-the-art robotics research and deployed industrial AI systems.

factory

AI Engineer

2025.06 – Present

NTS Solutions

Industrial process automation — computer-vision and VLM systems for semiconductor manufacturing (see Industry Projects above).

hub

AI & Robotics Researcher

2025.04 – 2025.05

UNIST — Ahri Lab

Designed and built a CLIP-style motion–language reward-model prototype for automatic semantic evaluation of robot motion — a scalable substitute for human feedback in RLHF (see Research above).

science

AI & Robotics Research Assistant

2022 – 2025

UNIST — Ahri Lab

Lead researcher on motion retargeting and RLHF-based motion refinement — an IROS 2024 first-author publication and the core of the M.S. thesis.

Academic Foundations

EXCELLENCE RECORD
school
Valedictorian 2022 — 2025

M.S. in Computer Science and Engineering

UNIST (Ulsan National Institute of Science and Technology)

3.99 / 4.3 GPA
workspace_premium
Summa Cum Laude 2018 — 2022

B.S. in Intelligent Mechanical Engineering

Silla University

4.39 / 4.5 GPA

Awards & Honors

RECOGNITION
military_tech
Government Scholarship 2017 — 2022

Global Korea Scholarship (GKS)

NIIED · Ministry of Education, Republic of Korea

verified View certificate
emoji_events
Academic Excellence 2021

Award for Outstanding Academic Achievement

Korean Ministry of Education

verified View certificate

Academic Service

COMMUNITY & TEACHING
rate_review

Peer Reviewer

Reviewed submissions for a top-tier robotics venue.

open_in_new ICRA 2025
volunteer_activism

Student Volunteer

Supported on-site operations at a flagship robotics conference.

open_in_new RSS 2023
school

Teaching Assistant

UNIST CS courses (Advanced Programming, Principles of Programming Languages, Intro to Algorithms, AI Toolkits), the STAR-MOOC course on Data Representation, and LG Electronics data-analysis training.

open_in_new STAR-MOOC UNIST · 2022 – 2025

Additional Projects

COURSEWORK & UNDERGRAD
Graduate Coursework
Multi-teacher knowledge-distillation pipeline: fine-tuned YOLOv6, YOLOv3-pedestrian and Progressive DETR teachers distilling into a YOLOv6 student for human detection.
visibility Fall 2023

Multi-Domain Knowledge Distillation for Robust Human Detection

A multi-teacher, multi-domain knowledge-distillation framework for human detection: three domain specialists — a fine-tuned YOLOv6 (indoor), YOLOv3-pedestrian (outdoor, EuroCity Persons) and Progressive DETR (crowded, CrowdHuman) — distill into a single YOLOv6 student via a novel object-detection distillation loss that pairs response-based classification distillation with a bounded loss for bounding-box regression, lifting mAP from 0.172 to 0.261 on CodaLab.

Knowledge Distillation Object Detection YOLOv6 DETR PyTorch
Illustration: the Spanish-only BETO model (left) and the multilingual XLM-RoBERTa model (right) moderating toxic social-media comments across Spanish, Turkish and French.
forum Spring 2022

Hate Speech Detection for Low-Resource Spanish with XLM-RoBERTa-CNN

A hate-speech detection system for Spanish — a low-resource language for this task — pairing the multilingual XLM-RoBERTa transformer with a CNN classification head. Instead of leaning on machine translation to fill the Spanish data gap, the project tests whether natural data from related languages (Spanish, French, Turkish) can carry the task on its own. It can — with enough fine-tuning, pure multilingual data gave the best Spanish results (F1 0.83, recall 0.85 at four epochs), outperforming the translation-based approach, while XLM-RoBERTa-CNN beat a Spanish-specific BETO-CNN on recall. Translation reached strong performance faster, in a single epoch, but it carries the cost of translating the datasets and degraded with longer training as translation bias set in.

NLP Hate Speech Detection XLM-RoBERTa CNN PyTorch
Undergraduate
The self-built robot car on the physical training track used for behavioral cloning.
directions_car Capstone · 2021

Vision-Based Self-Driving Car via Imitation Learning

A self-built robot car that learns to follow a track by behavioral cloning — a CNN maps camera frames to driving actions. Adapted NVIDIA PilotNet to a small (~1,900-frame) self-collected dataset by reframing steering as 3-class classification with a categorical NLL loss, swapping ReLU for PReLU, and using a lighter convolutional stack — raising validation accuracy from 57% to 81% and letting the car drive the track reliably on its own.

Imitation Learning CNN Computer Vision Raspberry Pi Keras
System architecture: Amazon Echo to Alexa Voice Service to a Node.js skill to PubNub cloud to Raspberry Pi to Arduino to the motors.
mic Team Lead · 2018

Voice-Controlled Robot Car via Amazon Alexa

A first-year embedded-systems team project (as team lead): a robot car driven by spoken commands. Built an end-to-end pipeline — Amazon Echo → Alexa Voice Service → a Node.js skill → PubNub cloud messaging → Raspberry Pi → Arduino → motors — and compared it against a lighter Bluetooth-app control path. Hands-on integration across JavaScript, Python and C++/Arduino, from cloud to hardware.

Amazon Alexa Arduino Raspberry Pi IoT Node.js