A Novel User Intent Prediction System for Improved Ad Targeting Strategies
Rian Khetani and Pranav Kulkarni
Abstract: Predicting customer intent in real time is a challenge in ecommerce. Failing to correctly identify whether a user is browsing or on the verge of purchase typically results in inefficient ad targeting and wasted impressions. Accurately determining customer intent allows for more effective ad allocation, saves costs, and improves conversion rates. In this study, we present a novel user intent prediction system that leverages customer interaction logs and item properties to classify sessions based on intent. By modeling these behaviors, the system aims to accurately determine the customer's intent which allows for better aligned ads with the customer's intent and buying stage, leading to higher conversion rates and improved ROI. Using the publicly available Retailrocket recommender system dataset that contains web events, item metadata, and category hierarchy, we employ multi-snapshot augmentation, session-level and prefix-based feature engineering, historical conversion rate features, categorical encoding, leaky feature removal, and median imputation combined with time-aware data splitting and LightGBM with class-imbalance weighting and F1-based threshold optimization. We achieve a high overall accuracy of 0.979, AUC of 0.906, and a PR-AUC of 0.296 (over 4x better than baseline of 0.07). While the high accuracy is driven by the dominance of non-purchase sessions ( 93% of dataset), the system is able to meaningfully distinguish purchase intent under class imbalance. These results demonstrate that the model can effectively flag valuable users for ad targeting, offering a significant improvement over baselines. The system represents a step toward practical real-time intent detection and is designed to evolve toward deep learning and sequence based models, where the order and timing of interactions (views, clicks, add-to-cart, purchases) may offer richer predictive signals than static features alone. Aside from ad targeting, our system has applications in personalized product recommendation, A/B testing, and general domains like finance or streaming platforms where behavior prediction is critical.
Keyframe Selection Strategies for Balancing Global Accuracy and Local Stability in Endoscopic SLAM
Hyeon-Seo Kim, Seokmin Hong, and Byungjeon Kang
Abstract: This study evaluates the effect of keyframe selection strategies on endoscopic simultaneous localization and mapping (SLAM) using the trans t2 b sequence of the C3VD dataset. Six strategies, including Fixed-interval, Adaptive baseline, Adaptive kf25/50/100, and Sharp-photo only, were compared. The Fixed-interval method achieved the highest global accuracy, reporting the lowest errors in ATE Sim(3) (11.43 mm) and ATE SE(3) (16.30 mm). In contrast, Adaptive kf50 exhibited the largest global error (18.38 mm and 18.63 mm, respectively). For local stability, the Sharp-photo only strategy demonstrated the best rotational precision with Rotation RPE Δ = 1: 0.36° and Δ = 5: 1.14°, whereas Adaptive kf25 showed the largest rotational deviation at Δ = 5 (1.30°). In terms of translational stability, Adaptive Kf50 achieved the lowest Translation RPE Δ = 1 (2.95 mm), while Sharp-photo only maintained the best performance at Δ = 5 (5.53 mm). Overall, these results highlight a trade-off between global trajectory accuracy and local motion stability, suggesting that while adaptive scheduling enhances frame efficiency, Fixed-interval and Sharp-photo only approaches provide more consistent and robust performance under endoscopic imaging conditions.
A PDMS-Based Acoustic Fresnel Lens for Vortex Trapping of Microparticles
Viet Hoang Nguyen; Hiep Xuan Cao, Daewon Jung, Jong-oh Park; Byungjeon Kang
Abstract: Acoustic tweezers have gained increasing attention as a contactless method for particle manipulation, yet most existing implementations rely on bulky standing-wave devices or complex phased transducer arrays that restrict their practicality. In this study, we propose and demonstrate a PDMS-based acoustic lens inspired by the principle of a Fresnel zone plate. The lens was fabricated using a simple and low-cost mold-casting process, highlighting its scalability and suitability for compact acoustic systems. Numerical simulations and experimental validations confirmed the effectiveness of the proposed lens, demonstrating its ability to generate a vortex trap and to stably confine a 3D-printed spherical particle with a diameter of 750 μm. These findings establish the PDMS acoustic lens as a practical and cost-effective alternative for acoustic manipulation, while also opening opportunities for its future integration into biomedical, diagnostic, and microfluidic platforms.
Mode-Switching-Based Control Algorithm in Acoustic Actuator for 3D Microrobot Manipulation in Nonhomogeneous Medium
Hiep Xuan Cao, Daewon Jung, Hoang Viet Nguyen, Seokmin Hong, Jong-oh Park, and Byungjeon Kang
Abstract: Acoustic technologies offer a promising and versatile toolkit for tracking and manipulating both synthetic and biological objects, ranging from nanometer to millimeter sizes, within complex biological environments. This work reports a Mode-Switching-Based Control Algorithm was developed to precisely control a microrobot. We developed an integrated system employing a single acoustic actuator capable of both transmitting and receiving signals, thereby streamlining the hardware architecture. Experimental results demonstrated a 22.7% enhancement in peak acoustic pressure. Positional accuracy was validated with mean deviations of 80 ± 75 micrometers, 71 ± 70 micrometers, and 204 ± 200 micrometers along the X, Y, and Z axes, respectively well below the microrobot's 600 micrometers body length indicating high-fidelity control. This proof-of-concept highlights the potential for dual-function acoustic devices to enable simultaneous tracking and manipulation, paving the way for advanced biomedical applications.
On-Device Vision Language Model Based Natural Language Mission Execution Framework
Seunggyu Lee, Seungjun Oh, Sangwoo Jeon, Youngju Park, Siwon Lee, Ghilmo Choi, and Dae-Sung Jang
Abstract: This work presents a framework that enables robots to assist with everyday tasks by leveraging Vision-Language Models (VLMs). Our framework takes both environmental information and natural language commands from users as inputs. An on-device VLM generates and validates a behavioral plan, represented as a sequence of pseudo-functions, using an actor-critic structure. These pseudo-functions are then connected to the low-level control system of a UGV to demonstrate the feasibility of the approach. Experimental results show that the framework can reliably interpret and execute user commands, highlighting its potential as a step toward practical robot assistance in daily life.
Situation-Aware Risk Quantification for UAV-Satellite Communications using Semantic Anomaly Detection
Junbeom Park, Zizung Yoon, and Jongsou Park
Abstract: Unmanned Aerial Vehicle (UAV)–satellite communications are increasingly critical for mission operations yet remain vulnerable to diverse packet-level and protocol-level threats, including jamming and spoofing. Existing intrusion detection systems (IDSs), however, lack situational awareness, often assessing anomalies with static severity regardless of mission context. This study introduces a semantic detection approach that integrates DistilBERT-based packet classification with a mission-phase–aware risk score to provide situationally adaptive anomaly assessment. The proposed framework is evaluated on a custom dataset extended to six traffic classes, embedding packet-level symptoms of threats across both the packet and protocol layers. Experimental results demonstrate that DistilBERT achieves 99.0% accuracy and a 98.9% macro-F1 score, while maintaining an inference latency of 26.2ms per packet—making it suitable for on-board deployment. More importantly, the proposed Situational Risk Score effectively differentiates threat criticality across mission phases. It reveals that spoofing and privilege abuse are most critical during takeoff and landing, whereas jamming poses the greatest risk during mission execution. These findings confirm that combining semantic anomaly detection with situational context not only ensures high accuracy but also delivers operationally relevant risk quantification for UAV–satellite systems.
Design, fabrication and evaluation of 6R-Pantograph Antenna mechanism
Hyeongseok Kang and Byungkyu Kim
Abstract: Research on the development of satellite antenna technologies for rapidly transmitting large volumes of data has been actively conducted. Since the performance of an antenna is determined by the size of its aperture, the development of large antenna deployment mechanisms is essential. Accordingly, the 6R-Pantograph Antenna, which combines the conventional 6R Ring-truss antenna structure with a pantograph module is proposed. To verify the performance and feasibility of the proposed antenna mechanism, synchronization and deployment performance were evaluated with three different deployment methods (1. free deployment using torsion springs; 2. deployment speed control using a wire; 3. deployment using the pantograph module). Conclusively, experimental results showed that the pantograph module driven deployment method enables stable synchronized deployment.