2025/09/03 更新

ガルシア クリスティーナ
Christina Alvarez Garcia
Christina Alvarez Garcia
所属
研究本部 重点プロジェクトセンター ケアXDXセンター
職名
助教

取得学位

  • 九州工業大学  -  博士(工学)   2024年03月

学内職務経歴

  • 2024年11月 - 現在   九州工業大学   研究本部   重点プロジェクトセンター   ケアXDXセンター     助教

所属学会・委員会

論文

  • Summary of the Silent Speech Decoding Challenge Using EEG Data for Arabic Inner Speech Recognition 招待有り 査読有り 国際誌

    Muhammad E. H. Chowdhury, Rusab Sarmun, Diala Bushnaq, Malek Chabbouh, Raghad Aljindi, Shona Pedersen, Md. Ahasan Atick Faisal, Nazmun Nahid, Iqbal Hassan, Ryuya Munemoto, Christina Garcia, Sozo Inoue

    International Journal of Activity and Behavior Computing ( Care XDX Center, Kyushu Institute of Technology )   2025 ( 2 )   1 - 21   2025年08月

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    担当区分:責任著者   記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)

    Abu Dhabi, United Arab Emirates   https://abc-research.github.io/2025   2025年04月21日  -  2025年04月25日

    The Silent Speech Decoding Challenge, hosted as part of the ABC 2025 conference, was designed to advance the decoding of silent (inner) speech from electroencephalography (EEG) signals, specifically targeting Arabic language processing. Participants leveraged advanced machine learning (ML) and deep learning (DL) techniques to classify EEG data from a uniquely collected dataset. This dataset, gathered by Qatar University's Machine Learning Group, consisted of EEG recordings from ten subjects across multiple sessions, capturing both silent and overt speech for six distinct inner speech commands. Participants were tasked with developing robust ML/DL models to accurately decode these neural signals, addressing challenges such as generalization across subjects and robustness to noise and motion artifacts.

    DOI: https://doi.org/10.60401/ijabc.104

    DOI: https://doi.org/10.60401/ijabc.104

    その他リンク: https://autocare.ai/abc2025

  • Summary of the BeyondSmile Challenge on Detecting Depression Through Facial Behavior and Head Gestures 招待有り 査読有り 国際誌

    Rahul Islam, Tongze Zhang, Anlan Dong, Melik Ozolcer, Christina Garcia, Milyun Ni’ma Shoumi, Prerna Jamloki, Sozo Inoue, Sang Won Bae

    International Journal of Activity and Behavior Computing ( Care XDX Center, Kyushu Institute of Technology )   2025 ( 2 )   1 - 15   2025年08月

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    担当区分:責任著者   記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)

    Abu Dhabi, United Arab Emirates   https://abc-research.github.io/2025   2025年04月21日  -  2025年04月25日

    Early detection of depressive episodes is crucial in managing mental health disorders such as Major Depressive Disorder (MDD) and Bipolar Disorder. However, existing methods often necessitate active participation or are confined to clinical settings. While facial expressions have shown promise in laboratory settings for identifying depression, their potential in real-world applications remains largely unexplored. In this challenge we introduce a data collected state of the art facial behavior sensing system, that tracks different facial behavior primitives such as Action Units, Landmarks, Head Pose, Eye Open state and others for task of detecting depressive episode in the wild. The challenge duration was three months, from Dec 12, 2024 to Feb 28, 2025 and 8 teams participated. Among the final teams, Team Persistence (Team ID 160) achieved 0.77 AUROC for universal model and 0.88 AUROC for hybrid model and became the winner.

    DOI: https://doi.org/10.60401/ijabc.102

    DOI: https://doi.org/10.60401/ijabc.102

    その他リンク: https://autocare.ai/abc2025

  • Summary of the Virtual Data Generation for Complex Industrial Activity Recognition 招待有り 査読有り 国際誌

    Qingxin Xia, Christina Garcia, Umang Dobhal, Min Xinyi, Tanigaki Kei, Nagoya Yoshimura, Sozo Inoue, Takuya Maekawa, Kaishun Wu

    International Journal of Activity and Behavior Computing ( Care XDX Center, Kyushu Institute of Technology )   2025 ( 2 )   1 - 12   2025年05月

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    担当区分:責任著者   記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)

    Abu Dhabi, United Arab Emirates   https://abc-research.github.io/2025   2025年04月21日  -  2025年04月25日

    This paper presents a summary of the virtual data generation for complex industrial activity recognition Challenge, which focused on exploring virtual data generation techniques to improve the performance of human activity recognition (HAR) in complex industrial environments. The challenge utilized the OpenPack dataset, a large-scale multimodal collection of sensor data captured during real-world packaging operations. Participants were tasked with generating synthetic accelerometer data to augment a baseline HAR model.

    DOI: https://doi.org/10.60401/ijabc.101

    DOI: https://doi.org/10.60401/ijabc.101

    その他リンク: https://autocare.ai/abc2025

  • Toward Abnormal Activity Recognition of Developmentally Disabled Individuals Using Pose Estimation 査読有り 国際誌

    Taihei Fujioka, Christina Garcia, Sozo Inoue

    International Journal of Activity and Behavior Computing ( Care XDX Center, Kyushu Institute of Technology )   2025 ( 1 )   1 - 28   2025年05月

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    担当区分:責任著者   記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)

    Abu Dhabi, United Arab Emirates   https://abc-research.github.io/2025   2025年04月21日  -  2025年04月25日

    抄録
    In this study, we propose to optimize temporal parameters with pose estimation data of simulated abnormal activities of developmentally disabled individuals by incorporating behavior context to Large Language Models (LLMs). Facilities for the developmentally disabled face the challenge of detecting abnormal behaviors because of limited staff and the difficulty of spotting subtle movements. Traditional methods often struggle to identify these behaviors because abnormal actions are irregular and unpredictable, leading to frequent misses or misclassifications. The main contributions of this work is the creation of a unique dataset with labeled abnormal behaviors and the proposed application of LLMs to this dataset comparing results of Zero-Shot and Few-Shot. Our method leverages the context of the collected abnormal activity data to prompt LLMs to suggest window size, overlap rate, and LSTM model’s length sequence tailored to the specific characteristics of these activities.

    DOI: https://doi.org/10.60401/ijabc.39

    DOI: https://doi.org/10.60401/ijabc.39

    その他リンク: https://autocare.ai/abc2025

  • Nurse Activity Recognition in Gastrostomy Tube Feeding Using Video-Based Pose with Large Language Model-Guided Features 査読有り 国際誌

    Lingfeng Zhao, Christina Garcia, Shunsuke Komizunai, Noriyo Colley, Atsuko Sato, Mayumi Kouchiyama, Toshiko Nasu, Sozo Inoue

    International Journal of Activity and Behavior Computing ( Care XDX Center, Kyushu Institute of Technology )   2025 ( 1 )   1 - 28   2025年05月

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    担当区分:責任著者   記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)

    Abu Dhabi, United Arab Emirates   https://abc-research.github.io/2025   2025年04月21日  -  2025年04月25日

    抄録
    In this paper, we improve nursing activity recognition in gastrostomy tube feeding (GTF) with temporal variations and sequential errors by integrating activity context to Large Language Model (LLM) for guided feature selection and post-processing. GTF is a delicate nursing procedure that allows direct stomach access in children for supplemental feeding or medication, but it is underrepresented in datasets, posing challenges for accurate detection. Leveraging the contextual adaptability of LLMs, we generate new features suggested by the language model, combining them with hand-crafted features to optimize the model. For post-processing, a sliding window smoothing method based on majority voting is applied. To mitigate duration-based discrepancies, a priority handling is incorporated for short-duration activities to pre- serve their recognition accuracy while addressing repeated labels caused by long-duration actions.

    DOI: https://doi.org/10.60401/ijabc.38

    DOI: https://doi.org/10.60401/ijabc.38

    その他リンク: https://autocare.ai/abc2025

  • Toward Detecting and Explaining Stress of Nurses Using Wearable Devices and LLMs 査読有り 国際誌

    Naoya Miyake, Haru Kaneko, Elsen Ronando, Christina Garcia, Sozo Inoue

    Proceedings of the International Conference on Ubiquitous Computing and Ambient Intelligence (UCAmI 2024) ( Springer Cham )   1212   288 - 299   2024年12月

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    担当区分:責任著者   記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)

    Northern Ireland, United Kingdom   https://ucami.org/ucami2024/   2024年11月27日  -  2024年11月29日

    In this paper, we improve nurse stress detection using wearable device data by balancing the dataset through Large Language Models (LLMs). The rise in wearable technologies has spurred stress detection studies in both daily life and healthcare settings. However, integrating an LLM on stress detection with wearable devices is still emerging. Data imbalance and faulty sensor readings, especially from EDA sensors in devices like the E4, can significantly impact the accuracy of stress detection models. To address this, we utilize LLMs to mitigate data imbalance by generating relevant synthetic samples through varied contextual prompting strategies. We compared Zero-shot, Few-shot, Zero-shot CoT, and Few-shot CoT prompting ability on data generation. We benchmark the LLM approach against SMOTE and Random Sampling comparing overall performance on stress detection. Furthermore, we employ the RACCCA (Relevance, Accuracy, Completeness, Clarity, Coherence, Appropriateness) framework to assess the quality of prompting and output.

    DOI: https://doi.org/10.1007/978-3-031-77571-0_28

    DOI: https://doi.org/10.1007/978-3-031-77571-0_28

    その他リンク: https://link.springer.com/book/10.1007/978-3-031-77571-0

  • Synthetic Skeleton Data Generation using Large Language Model for Nurse Activity Recognition 査読有り 国際誌

    Umang Dobhal, Christina Garcia, Sozo Inoue

    In Companion of the 2024 on ACM International Joint Conference on Pervasive and Ubiquitous Computing (UbiComp '24) ( Association for Computing Machinery, New York )   2024   493 - 499   2024年10月

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    担当区分:責任著者   記述言語:英語   掲載種別:研究論文(国際会議プロシーディングス)

    Melbourne, Australia   https://www.ubicomp.org/ubicomp-iswc-2024/   2024年10月05日  -  2024年10月09日

    In this paper, we improve nurse activity recognition by employing a Large Language Model (LLM) to generate synthetic pose estimation data. Keypoint data extracted from recorded videos of a single nurse performing Endotracheal suctioning (ES) activities using You Only Look Once v7 (YOLOv7) is used as a database. We explore the issue of data imbalances that hinder the effectiveness of activity recognition algorithms. To counter this, we utilize LLMs to artificially augment the dataset by generating varied synthetic samples through prompting strategies with different content and context. Additionally, we generate synthetic datasets in equal volumes using Random Sampling and Generative Adversarial Networks (GAN) to benchmark against our LLM-based approach. To evaluate, we compared the performance between baseline data and different augmentation approaches. The similarity between original and synthetic data is measured using the Kolmogorov-Smirnov (K-S) test.

    DOI: https://doi.org/10.1145/3675094.3678445

    DOI: https://doi.org/10.1145/3675094.3678445

    その他リンク: https://dl.acm.org/doi/abs/10.1145/3675094.3678445

▼全件表示

口頭発表・ポスター発表等

  • Indoor Localization in Nursing Care Facility Using Large Language Models 招待有り

    Christina Garcia

    7th International Conference on Activity and Behavior Computing  2025年04月  7th International Conference on Activity and Behavior Computing

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    開催期間: 2025年04月21日 - 2025年04月25日   記述言語:英語   開催地:Abu Dhabi, United Arab Emirates   国名:アラブ首長国連邦  

    In this study, we use Large Language Models (LLMs) for room recognition in nursing facilities, leveraging contextual data to address data limitations. Traditional models struggle with Received Signal Strength Indicator (RSSI) variability and sparse data. LLMs offer a promising alternative by integrating domain knowledge to address signal inconsistencies and improve localization accuracy.

    その他リンク: https://abc-research.github.io/2025

学術関係受賞

  • Best Short Paper Awardee

    12th International Conference on Informatics, Electronics & Vision (ICIEV)   LLM-based Indoor Localization in Nursing Care Facility: A Zero-Shot Ablation Study   2025年05月29日

    Christina Garcia, Sozo Inoue

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    受賞国:日本国

    Awarded Best Short Paper for the work "LLM-based Indoor Localization in Nursing Care Facility: A Zero-Shot Ablation Study" presented during the 12th International Conference on Informatics, Electronics & Vision (ICIEV) in Japan last May 26-29, 2025.

  • Outstanding Contribution Awardee

    7th International Conference on Activity and Behavior Computing   Outstanding Contribution Awardee   2025年04月25日

    Christina Garcia

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    受賞国:アラブ首長国連邦

    Awarded with Outstanding Contribution for actively serving as Challenge Organization Chair co-hosting four coding challenges with various universities while also serving as the Publication Chair.

  • Excellent Paper Awardee

    5th International Conference on Activity and Behavior Computing   A Relabeling Approach to Signal Patterns for Beacon-based Indoor Localization in Nursing Care Facility   2023年09月09日

    Christina Garcia, Sozo Inoue

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    受賞国:ドイツ連邦共和国

    Awarded Excellent Paper for the work "A Relabeling Approach to Signal Patterns for Beacon-based Indoor Localization in Nursing Care Facility" presented in the 5th International Conference on Activity and Behavior Computing held in Kaiserslautern, Germany last September 7th - 9th, 2023.

  • Best Paper Awardee

    22nd World Conference on Applied Science, Engineering and Technology   Non-invasive Diabetes Detection using Facial Texture Features Captured in a Less Restrictive Environment   2019年09月27日

    Christina Garcia

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    受賞国:シンガポール共和国

    Awarded Best Paper for the work titled "Non-invasive Diabetes Detection using Facial Texture Features Captured in a Less Restrictive Environment" presented during the 22nd World Conference on Applied Science, Engineering and Technology held on September 2019 in Singapore.

  • Best Department Project Thesis Awardee

    Mindanao State University - Iligan Institute of Technology, College of Engineering   Fast Lock-in Time Phase Locked Loop Frequency Synthesizer for Continuous-Time Sigma-Delta ADC   2013年04月08日

    Christina Garcia, Stella Sofia Sabate

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    受賞国:フィリピン共和国

    Bachelor thesis implemented using Synopsis Industry tool grade for design. Frequency Detector with NOR gates and divide-by-64 with pseudo-NMOS divide-by-2 frequency divider is proposed, designed and simulated in TSMC 0.18 um 1P6M CMOS process technology to come up with minimum chip area and achieve fast lock-in time. This PLL design is specifically intended for Continuous-Time Sigma-Delta ADC operating at 640MHz frequency which is an important component of ICs used in electronics and communication devices whose clock rates and timing relationships are vital. This work has a lock-time of around 2.5 us which is a fast lock-in value for the lock-in time of ADC clock generator. T