1,121 results on '"Chang Yu-Cheng"'
Search Results
2. A Self-Constructing Multi-Expert Fuzzy System for High-dimensional Data Classification
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Ren, Yingtao, Chang, Yu-Cheng, Do, Thomas, Cao, Zehong, and Lin, Chin-Teng
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Computer Science - Machine Learning - Abstract
Fuzzy Neural Networks (FNNs) are effective machine learning models for classification tasks, commonly based on the Takagi-Sugeno-Kang (TSK) fuzzy system. However, when faced with high-dimensional data, especially with noise, FNNs encounter challenges such as vanishing gradients, excessive fuzzy rules, and limited access to prior knowledge. To address these challenges, we propose a novel fuzzy system, the Self-Constructing Multi-Expert Fuzzy System (SOME-FS). It combines two learning strategies: mixed structure learning and multi-expert advanced learning. The former enables each base classifier to effectively determine its structure without requiring prior knowledge, while the latter tackles the issue of vanishing gradients by enabling each rule to focus on its local region, thereby enhancing the robustness of the fuzzy classifiers. The overall ensemble architecture enhances the stability and prediction performance of the fuzzy system. Our experimental results demonstrate that the proposed SOME-FS is effective in high-dimensional tabular data, especially in dealing with uncertainty. Moreover, our stable rule mining process can identify concise and core rules learned by the SOME-FS.
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- 2024
3. iFuzzyTL: Interpretable Fuzzy Transfer Learning for SSVEP BCI System
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Jiang, Xiaowei, Cao, Beining, Ou, Liang, Chang, Yu-Cheng, Do, Thomas, and Lin, Chin-Teng
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Computer Science - Human-Computer Interaction ,Computer Science - Machine Learning - Abstract
The rapid evolution of Brain-Computer Interfaces (BCIs) has significantly influenced the domain of human-computer interaction, with Steady-State Visual Evoked Potentials (SSVEP) emerging as a notably robust paradigm. This study explores advanced classification techniques leveraging interpretable fuzzy transfer learning (iFuzzyTL) to enhance the adaptability and performance of SSVEP-based systems. Recent efforts have strengthened to reduce calibration requirements through innovative transfer learning approaches, which refine cross-subject generalizability and minimize calibration through strategic application of domain adaptation and few-shot learning strategies. Pioneering developments in deep learning also offer promising enhancements, facilitating robust domain adaptation and significantly improving system responsiveness and accuracy in SSVEP classification. However, these methods often require complex tuning and extensive data, limiting immediate applicability. iFuzzyTL introduces an adaptive framework that combines fuzzy logic principles with neural network architectures, focusing on efficient knowledge transfer and domain adaptation. iFuzzyTL refines input signal processing and classification in a human-interpretable format by integrating fuzzy inference systems and attention mechanisms. This approach bolsters the model's precision and aligns with real-world operational demands by effectively managing the inherent variability and uncertainty of EEG data. The model's efficacy is demonstrated across three datasets: 12JFPM (89.70% accuracy for 1s with an information transfer rate (ITR) of 149.58), Benchmark (85.81% accuracy for 1s with an ITR of 213.99), and eldBETA (76.50% accuracy for 1s with an ITR of 94.63), achieving state-of-the-art results and setting new benchmarks for SSVEP BCI performance.
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- 2024
4. A Fuzzy-based Approach to Predict Human Interaction by Functional Near-Infrared Spectroscopy
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Jiang, Xiaowei, Ou, Liang, Chen, Yanan, Ao, Na, Chang, Yu-Cheng, Do, Thomas, and Lin, Chin-Teng
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Computer Science - Artificial Intelligence ,Quantitative Biology - Neurons and Cognition - Abstract
The paper introduces a Fuzzy-based Attention (Fuzzy Attention Layer) mechanism, a novel computational approach to enhance the interpretability and efficacy of neural models in psychological research. The proposed Fuzzy Attention Layer mechanism is integrated as a neural network layer within the Transformer Encoder model to facilitate the analysis of complex psychological phenomena through neural signals, such as those captured by functional Near-Infrared Spectroscopy (fNIRS). By leveraging fuzzy logic, the Fuzzy Attention Layer is capable of learning and identifying interpretable patterns of neural activity. This capability addresses a significant challenge when using Transformer: the lack of transparency in determining which specific brain activities most contribute to particular predictions. Our experimental results demonstrated on fNIRS data from subjects engaged in social interactions involving handholding reveal that the Fuzzy Attention Layer not only learns interpretable patterns of neural activity but also enhances model performance. Additionally, the learned patterns provide deeper insights into the neural correlates of interpersonal touch and emotional exchange. The application of our model shows promising potential in deciphering the subtle complexities of human social behaviors, thereby contributing significantly to the fields of social neuroscience and psychological AI.
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- 2024
5. Thermal spectrometer for superconducting circuits
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Satrya, Christoforus Dimas, Chang, Yu-Cheng, Upadhyay, Rishabh, Makinen, Ilari K., Peltonen, Joonas T., Karimi, Bayan, and Pekola, Jukka P.
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Quantum Physics ,Condensed Matter - Mesoscale and Nanoscale Physics ,Condensed Matter - Materials Science ,Condensed Matter - Other Condensed Matter ,Condensed Matter - Superconductivity - Abstract
Superconducting circuits provide a versatile and controllable platform for studies of fundamental quantum phenomena as well as for quantum technology applications. A conventional technique to read out the state of a quantum circuit or to characterize its properties is based on rf measurement schemes involving costly and complex instrumentation. Here we demonstrate a simple dc measurement of a thermal spectrometer to investigate properties of a superconducting circuit, in this proof-of-concept experiment a coplanar waveguide resonator. A fraction of the microwave photons in the resonator is absorbed by an on-chip bolometer, resulting in a measurable temperature rise. By monitoring the dc signal of the thermometer due to this process, we are able to determine the resonance frequency and the lineshape (quality factor) of the resonator. The demonstrated scheme, which is a simple dc measurement, has a wide band up to 200 GHz, well exceeding that of the typical rf spectrometer. Moreover, the thermal measurement yields a highly frequency independent reference level of the Lorentzian absorption signal, unlike the conventional rf measurement. In the low power regime, the measurement is fully calibration-free. Our technique thus offers an alternative spectrometer for quantum circuits, which is in many ways superior with respect to conventional methods., Comment: 13 pages and 10 figures
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- 2024
6. Enhancing End-to-End Autonomous Driving Systems Through Synchronized Human Behavior Data
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Duan, Yiqun, Zhuang, Zhuoli, Zhou, Jinzhao, Chang, Yu-Cheng, Wang, Yu-Kai, and Lin, Chin-Teng
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Computer Science - Robotics ,Computer Science - Human-Computer Interaction - Abstract
This paper presents a pioneering exploration into the integration of fine-grained human supervision within the autonomous driving domain to enhance system performance. The current advances in End-to-End autonomous driving normally are data-driven and rely on given expert trials. However, this reliance limits the systems' generalizability and their ability to earn human trust. Addressing this gap, our research introduces a novel approach by synchronously collecting data from human and machine drivers under identical driving scenarios, focusing on eye-tracking and brainwave data to guide machine perception and decision-making processes. This paper utilizes the Carla simulation to evaluate the impact brought by human behavior guidance. Experimental results show that using human attention to guide machine attention could bring a significant improvement in driving performance. However, guidance by human intention still remains a challenge. This paper pioneers a promising direction and potential for utilizing human behavior guidance to enhance autonomous systems.
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- 2024
7. Masked EEG Modeling for Driving Intention Prediction
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Zhou, Jinzhao, Sia, Justin, Duan, Yiqun, Chang, Yu-Cheng, Wang, Yu-Kai, and Lin, Chin-Teng
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Computer Science - Machine Learning ,Computer Science - Artificial Intelligence - Abstract
Driving under drowsy conditions significantly escalates the risk of vehicular accidents. Although recent efforts have focused on using electroencephalography to detect drowsiness, helping prevent accidents caused by driving in such states, seamless human-machine interaction in driving scenarios requires a more versatile EEG-based system. This system should be capable of understanding a driver's intention while demonstrating resilience to artifacts induced by sudden movements. This paper pioneers a novel research direction in BCI-assisted driving, studying the neural patterns related to driving intentions and presenting a novel method for driving intention prediction. In particular, our preliminary analysis of the EEG signal using independent component analysis suggests a close relation between the intention of driving maneuvers and the neural activities in central-frontal and parietal areas. Power spectral density analysis at a group level also reveals a notable distinction among various driving intentions in the frequency domain. To exploit these brain dynamics, we propose a novel Masked EEG Modeling framework for predicting human driving intentions, including the intention for left turning, right turning, and straight proceeding. Extensive experiments, encompassing comprehensive quantitative and qualitative assessments on public dataset, demonstrate the proposed method is proficient in predicting driving intentions across various vigilance states. Specifically, our model attains an accuracy of 85.19% when predicting driving intentions for drowsy subjects, which shows its promising potential for mitigating traffic accidents related to drowsy driving. Notably, our method maintains over 75% accuracy when more than half of the channels are missing or corrupted, underscoring its adaptability in real-life driving.
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- 2024
8. Towards Linguistic Neural Representation Learning and Sentence Retrieval from Electroencephalogram Recordings
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Zhou, Jinzhao, Duan, Yiqun, Zhao, Ziyi, Chang, Yu-Cheng, Wang, Yu-Kai, Do, Thomas, and Lin, Chin-Teng
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Computer Science - Computation and Language ,Computer Science - Artificial Intelligence ,Computer Science - Machine Learning - Abstract
Decoding linguistic information from non-invasive brain signals using EEG has gained increasing research attention due to its vast applicational potential. Recently, a number of works have adopted a generative-based framework to decode electroencephalogram (EEG) signals into sentences by utilizing the power generative capacity of pretrained large language models (LLMs). However, this approach has several drawbacks that hinder the further development of linguistic applications for brain-computer interfaces (BCIs). Specifically, the ability of the EEG encoder to learn semantic information from EEG data remains questionable, and the LLM decoder's tendency to generate sentences based on its training memory can be hard to avoid. These issues necessitate a novel approach for converting EEG signals into sentences. In this paper, we propose a novel two-step pipeline that addresses these limitations and enhances the validity of linguistic EEG decoding research. We first confirm that word-level semantic information can be learned from EEG data recorded during natural reading by training a Conformer encoder via a masked contrastive objective for word-level classification. To achieve sentence decoding results, we employ a training-free retrieval method to retrieve sentences based on the predictions from the EEG encoder. Extensive experiments and ablation studies were conducted in this paper for a comprehensive evaluation of the proposed approach. Visualization of the top prediction candidates reveals that our model effectively groups EEG segments into semantic categories with similar meanings, thereby validating its ability to learn patterns from unspoken EEG recordings. Despite the exploratory nature of this work, these results suggest that our method holds promise for providing more reliable solutions for converting EEG signals into text.
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- 2024
9. Breaking the Ceiling of the LLM Community by Treating Token Generation as a Classification for Ensembling
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Yu, Yao-Ching, Kuo, Chun-Chih, Ye, Ziqi, Chang, Yu-Cheng, and Li, Yueh-Se
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Computer Science - Computation and Language ,Computer Science - Artificial Intelligence - Abstract
Ensembling multiple models has always been an effective approach to push the limits of existing performance and is widely used in classification tasks by simply averaging the classification probability vectors from multiple classifiers to achieve better accuracy. However, in the thriving open-source Large Language Model (LLM) community, ensembling methods are rare and typically limited to ensembling the full-text outputs of LLMs, such as selecting the best output using a ranker, which leads to underutilization of token-level probability information. In this paper, we treat the Generation of each token by LLMs as a Classification (GaC) for ensembling. This approach fully exploits the probability information at each generation step and better prevents LLMs from producing early incorrect tokens that lead to snowballing errors. In experiments, we ensemble state-of-the-art LLMs on several benchmarks, including exams, mathematics and reasoning, and observe that our method breaks the existing community performance ceiling. Furthermore, we observed that most of the tokens in the answer are simple and do not affect the correctness of the final answer. Therefore, we also experimented with ensembling only key tokens, and the results showed better performance with lower latency across benchmarks., Comment: Accepted to EMNLP 2024
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- 2024
10. Contrastive learning-based agent modeling for deep reinforcement learning
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Ma, Wenhao, Chang, Yu-Cheng, Yang, Jie, Wang, Yu-Kai, and Lin, Chin-Teng
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Computer Science - Multiagent Systems ,Computer Science - Artificial Intelligence - Abstract
Multi-agent systems often require agents to collaborate with or compete against other agents with diverse goals, behaviors, or strategies. Agent modeling is essential when designing adaptive policies for intelligent machine agents in multiagent systems, as this is the means by which the ego agent understands other agents' behavior and extracts their meaningful policy representations. These representations can be used to enhance the ego agent's adaptive policy which is trained by reinforcement learning. However, existing agent modeling approaches typically assume the availability of local observations from other agents (modeled agents) during training or a long observation trajectory for policy adaption. To remove these constrictive assumptions and improve agent modeling performance, we devised a Contrastive Learning-based Agent Modeling (CLAM) method that relies only on the local observations from the ego agent during training and execution. With these observations, CLAM is capable of generating consistent high-quality policy representations in real-time right from the beginning of each episode. We evaluated the efficacy of our approach in both cooperative and competitive multi-agent environments. Our experiments demonstrate that our approach achieves state-of-the-art on both cooperative and competitive tasks, highlighting the potential of contrastive learning-based agent modeling for enhancing reinforcement learning., Comment: 8 pages, 6 figures
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- 2023
11. Dendritic cell vaccine for glioblastoma: an updated meta-analysis and trial sequential analysis
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Wong, Chia-En, Chang, Yu, Chen, Pei-Wen, Huang, Yan-Ta, Chang, Yu-Cheng, Chiang, Cho-Han, Wang, Liang-Chao, Lee, Po-Hsuan, Huang, Chi-Chen, Hsu, Heng-Juei, and Lee, Jung-Shun
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- 2024
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12. Thromboprophylaxis for outpatients with COVID-19: a Systematic Review and Meta-analysis
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Chiang, Cho-Han, Ahmed, Omer, Liu, Weitao, See, Xin Ya, Chang, Yu-Cheng, Peng, Chun-Yu, Wang, Zihan, Chiang, Cho-Hsien, Hsia, Yuan Ping, and Chiang, Cho-Hung
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- 2024
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13. BELT:Bootstrapping Electroencephalography-to-Language Decoding and Zero-Shot Sentiment Classification by Natural Language Supervision
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Zhou, Jinzhao, Duan, Yiqun, Chang, Yu-Cheng, Wang, Yu-Kai, and Lin, Chin-Teng
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Computer Science - Artificial Intelligence ,Computer Science - Computation and Language ,Electrical Engineering and Systems Science - Signal Processing - Abstract
This paper presents BELT, a novel model and learning framework for the pivotal topic of brain-to-language translation research. The translation from noninvasive brain signals into readable natural language has the potential to promote the application scenario as well as the development of brain-computer interfaces (BCI) as a whole. The critical problem in brain signal decoding or brain-to-language translation is the acquisition of semantically appropriate and discriminative EEG representation from a dataset of limited scale and quality. The proposed BELT method is a generic and efficient framework that bootstraps EEG representation learning using off-the-shelf large-scale pretrained language models (LMs). With a large LM's capacity for understanding semantic information and zero-shot generalization, BELT utilizes large LMs trained on Internet-scale datasets to bring significant improvements to the understanding of EEG signals. In particular, the BELT model is composed of a deep conformer encoder and a vector quantization encoder. Semantical EEG representation is achieved by a contrastive learning step that provides natural language supervision. We achieve state-of-the-art results on two featuring brain decoding tasks including the brain-to-language translation and zero-shot sentiment classification. Specifically, our model surpasses the baseline model on both tasks by 5.45% and over 10% and archives a 42.31% BLEU-1 score and 67.32% precision on the main evaluation metrics for translation and zero-shot sentiment classification respectively., Comment: We decided to redraw the manuscript because of the multi-error in the paper due to poor writing and inspection
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- 2023
14. MatrixWorld: A pursuit-evasion platform for safe multi-agent coordination and autocurricula
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Sun, Lijun, Chang, Yu-Cheng, Lyu, Chao, Lin, Chin-Teng, and Shi, Yuhui
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Computer Science - Multiagent Systems - Abstract
Multi-agent reinforcement learning (MARL) achieves encouraging performance in solving complex tasks. However, the safety of MARL policies is one critical concern that impedes their real-world applications. Popular multi-agent benchmarks focus on diverse tasks yet provide limited safety support. Therefore, this work proposes a safety-constrained multi-agent environment: MatrixWorld, based on the general pursuit-evasion game. Particularly, a safety-constrained multi-agent action execution model is proposed for the software implementation of safe multi-agent environments based on diverse safety definitions. It (1) extends the vertex conflict among homogeneous / cooperative agents to heterogeneous / adversarial settings, and (2) proposes three types of resolutions for each type of conflict, aiming at providing rational and unbiased feedback for safe MARL. Besides, MatrixWorld is also a lightweight co-evolution framework for the learning of pursuit tasks, evasion tasks, or both, where more pursuit-evasion variants can be designed based on different practical meanings of safety. As a brief survey, we review and analyze the co-evolution mechanism in the multi-agent setting, which clearly reveals its relationships with autocurricula, self-play, arms races, and adversarial learning. Thus, MatrixWorld can also serve as the first environment for autocurricula research, where ideas can be quickly verified and well understood.
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- 2023
15. The implication of serum HLA-G in angiogenesis of multiple myeloma
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Wang, Chi, Su, Nai-Wen, Hsu, Kate, Kao, Chen-Wei, Chang, Ming-Chih, Chang, Yi-Fang, Lim, Ken-Hong, Chiang, Yi-Hao, Chang, Yu-Cheng, Sung, Meng-Ta, Wu, Hsueh-Hsia, and Chen, Caleb G.
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- 2024
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16. Microwave quantum diode
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Upadhyay, Rishabh, Golubev, Dmitry S., Chang, Yu-Cheng, Thomas, George, Guthrie, Andrew, Peltonen, Joonas T., and Pekola, Jukka P.
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- 2024
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17. Analysis of mutation profiles in extranodal NK/T-cell lymphoma: clinical and prognostic correlations
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Chang, Yu-Cheng, Tsai, Hui-Jen, Huang, To-Yu, Su, Nai-Wen, Su, Ying-Wen, Chang, Yi-Fang, Chen, Caleb Gon-Shen, Lin, Johnson, Chang, Ming-Chih, Chen, Shu-Jen, Chen, Hua-Chien, Lim, Ken-Hong, Chang, Kung-Chao, and Kuo, Sung-Hsin
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- 2024
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18. Domain-Specific Denoising Diffusion Probabilistic Models for Brain Dynamics
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Duan, Yiqun, Zhou, Jinzhao, Wang, Zhen, Chang, Yu-Cheng, Wang, Yu-Kai, and Lin, Chin-Teng
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Computer Science - Human-Computer Interaction - Abstract
The differences in brain dynamics across human subjects, commonly referred to as human artifacts, have long been a challenge in the field, severely limiting the generalizability of brain dynamics recognition models. Traditional methods for human artifact removal typically employ spectrum filtering or blind source separation, based on simple prior distribution assumptions, which ultimately constrain the capacity to model each subject's domain variance. In this paper, we propose a novel approach to model human artifact removal as a generative denoising process, capable of simultaneously generating and learning subject-specific domain variance and invariant brain signals. We introduce the Domain Specific Denoising Diffusion Probabilistic Model (DS-DDPM), which decomposes the denoising process into subject domain variance and invariant content at each step. By incorporating subtle constraints and probabilistic design, we formulate domain variance and invariant content into orthogonal spaces and further supervise the domain variance with a subject classifier. This method is the first to explicitly separate human subject-specific variance through generative denoising processes, outperforming previous methods in two aspects: 1) DS-DDPM can learn more accurate subject-specific domain variance through domain generative learning compared to traditional filtering methods, and 2) DS-DDPM is the first approach capable of explicitly generating subject noise distribution. Comprehensive experimental results indicate that DS-DDPM effectively alleviates domain distribution bias for cross-domain brain dynamics signal recognition.
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- 2023
19. Microwave quantum diode
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Upadhyay, Rishabh, Golubev, Dmitry S., Chang, Yu-Cheng, Thomas, George, Guthrie, Andrew, Peltonen, Joonas T., and Pekola, Jukka P.
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Quantum Physics ,Condensed Matter - Superconductivity - Abstract
The fragile nature of quantum circuits is a major bottleneck to scalable quantum applications. Operating at cryogenic temperatures, quantum circuits are highly vulnerable to amplifier backaction and external noise. Non-reciprocal microwave devices such as circulators and isolators are used for this purpose. These devices have a considerable footprint in cryostats, limiting the scalability of quantum circuits. We present a compact microwave diode architecture, which exploits the non-linearity of a superconducting flux qubit. At the qubit degeneracy point we experimentally demonstrate a significant difference between the power levels transmitted in opposite directions. The observations align with the proposed theoretical model. At -99 dBm input power, and near the qubit-resonator avoided crossing region, we report the transmission rectification ratio exceeding 90% for a 50 MHz wide frequency range from 6.81 GHz to 6.86 GHz, and over 60% for the 250 MHz range from 6.67 GHz to 6.91 GHz. The presented architecture is compact, and easily scalable towards multiple readout channels, potentially opening up diverse opportunities in quantum information, microwave read-out and optomechanics., Comment: 13 pages, 8 figures
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- 2023
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20. Generalizing Multimodal Variational Methods to Sets
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Zhou, Jinzhao, Duan, Yiqun, Chen, Zhihong, Chang, Yu-Cheng, and Lin, Chin-Teng
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Computer Science - Artificial Intelligence - Abstract
Making sense of multiple modalities can yield a more comprehensive description of real-world phenomena. However, learning the co-representation of diverse modalities is still a long-standing endeavor in emerging machine learning applications and research. Previous generative approaches for multimodal input approximate a joint-modality posterior by uni-modality posteriors as product-of-experts (PoE) or mixture-of-experts (MoE). We argue that these approximations lead to a defective bound for the optimization process and loss of semantic connection among modalities. This paper presents a novel variational method on sets called the Set Multimodal VAE (SMVAE) for learning a multimodal latent space while handling the missing modality problem. By modeling the joint-modality posterior distribution directly, the proposed SMVAE learns to exchange information between multiple modalities and compensate for the drawbacks caused by factorization. In public datasets of various domains, the experimental results demonstrate that the proposed method is applicable to order-agnostic cross-modal generation while achieving outstanding performance compared to the state-of-the-art multimodal methods. The source code for our method is available online https://anonymous.4open.science/r/SMVAE-9B3C/., Comment: First Submission
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- 2022
21. Improving CCA Algorithms on SSVEP Classification with Reinforcement Learning Based Temporal Filtering
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Ou, Liang, Do, Thomas, Tran, Xuan-The, Leong, Daniel, Chang, Yu-Cheng, Wang, Yu-Kai, Lin, Chin-Teng, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Liu, Tongliang, editor, Webb, Geoff, editor, Yue, Lin, editor, and Wang, Dadong, editor
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- 2024
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22. Stratified assessment of an FDA-cleared deep learning algorithm for automated detection and contouring of metastatic brain tumors in stereotactic radiosurgery.
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Wang, Jen-Yeu, Qu, Vera, Hui, Caressa, Sandhu, Navjot, Mendoza, Maria, Panjwani, Neil, Chang, Yu-Cheng, Liang, Chih-Hung, Lu, Jen-Tang, Wang, Lei, Kovalchuk, Nataliya, Gensheimer, Michael, Soltys, Scott, and Pollom, Erqi
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Female ,Humans ,Male ,Algorithms ,Artificial Intelligence ,Brain Neoplasms ,Deep Learning ,Radiosurgery ,Retrospective Studies ,Young Adult ,Adult ,Middle Aged ,Aged ,Aged ,80 and over - Abstract
PURPOSE: Artificial intelligence-based tools can be leveraged to improve detection and segmentation of brain metastases for stereotactic radiosurgery (SRS). VBrain by Vysioneer Inc. is a deep learning algorithm with recent FDA clearance to assist in brain tumor contouring. We aimed to assess the performance of this tool by various demographic and clinical characteristics among patients with brain metastases treated with SRS. MATERIALS AND METHODS: We randomly selected 100 patients with brain metastases who underwent initial SRS on the CyberKnife from 2017 to 2020 at a single institution. Cases with resection cavities were excluded from the analysis. Computed tomography (CT) and axial T1-weighted post-contrast magnetic resonance (MR) image data were extracted for each patient and uploaded to VBrain. A brain metastasis was considered detected when the VBrain- predicted contours overlapped with the corresponding physician contours (ground-truth contours). We evaluated performance of VBrain against ground-truth contours using the following metrics: lesion-wise Dice similarity coefficient (DSC), lesion-wise average Hausdorff distance (AVD), false positive count (FP), and lesion-wise sensitivity (%). Kruskal-Wallis tests were performed to assess the relationships between patient characteristics including sex, race, primary histology, age, and size and number of brain metastases, and performance metrics such as DSC, AVD, FP, and sensitivity. RESULTS: We analyzed 100 patients with 435 intact brain metastases treated with SRS. Our cohort consisted of patients with a median number of 2 brain metastases (range: 1 to 52), median age of 69 (range: 19 to 91), and 50% male and 50% female patients. The primary site breakdown was 56% lung, 10% melanoma, 9% breast, 8% gynecological, 5% renal, 4% gastrointestinal, 2% sarcoma, and 6% other, while the race breakdown was 60% White, 18% Asian, 3% Black/African American, 2% Native Hawaiian or other Pacific Islander, and 17% other/unknown/not reported. The median tumor size was 0.112 c.c. (range: 0.010-26.475 c.c.). We found mean lesion-wise DSC to be 0.723, mean lesion-wise AVD to be 7.34% of lesion size (0.704 mm), mean FP count to be 0.72 tumors per case, and lesion-wise sensitivity to be 89.30% for all lesions. Moreover, mean sensitivity was found to be 99.07%, 97.59%, and 96.23% for lesions with diameter equal to and greater than 10 mm, 7.5 mm, and 5 mm, respectively. No other significant differences in performance metrics were observed across demographic or clinical characteristic groups. CONCLUSION: In this study, a commercial deep learning algorithm showed promising results in segmenting brain metastases, with 96.23% sensitivity for metastases with diameters of 5 mm or higher. As the software is an assistive AI, future work of VBrain integration into the clinical workflow can provide further clinical and research insights.
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- 2023
23. Federated Fuzzy Neural Network with Evolutionary Rule Learning
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Zhang, Leijie, Shi, Ye, Chang, Yu-Cheng, and Lin, Chin-Teng
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Computer Science - Machine Learning ,Computer Science - Neural and Evolutionary Computing - Abstract
Distributed fuzzy neural networks (DFNNs) have attracted increasing attention recently due to their learning abilities in handling data uncertainties in distributed scenarios. However, it is challenging for DFNNs to handle cases in which the local data are non-independent and identically distributed (non-IID). In this paper, we propose a federated fuzzy neural network (FedFNN) with evolutionary rule learning (ERL) to cope with non-IID issues as well as data uncertainties. The FedFNN maintains a global set of rules in a server and a personalized subset of these rules for each local client. ERL is inspired by the theory of biological evolution; it encourages rule variations while activating superior rules and deactivating inferior rules for local clients with non-IID data. Specifically, ERL consists of two stages in an iterative procedure: a rule cooperation stage that updates global rules by aggregating local rules based on their activation statuses and a rule evolution stage that evolves the global rules and updates the activation statuses of the local rules. This procedure improves both the generalization and personalization of the FedFNN for dealing with non-IID issues and data uncertainties. Extensive experiments conducted on a range of datasets demonstrate the superiority of the FedFNN over state-of-the-art methods.
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- 2022
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24. Hierarchical fuzzy neural networks with privacy preservation for heterogeneous big data
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Zhang, Leijie, Shi, Ye, Chang, Yu-Cheng, and Lin, Chin-Teng
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Computer Science - Machine Learning ,Computer Science - Artificial Intelligence ,Computer Science - Cryptography and Security - Abstract
Heterogeneous big data poses many challenges in machine learning. Its enormous scale, high dimensionality, and inherent uncertainty make almost every aspect of machine learning difficult, from providing enough processing power to maintaining model accuracy to protecting privacy. However, perhaps the most imposing problem is that big data is often interspersed with sensitive personal data. Hence, we propose a privacy-preserving hierarchical fuzzy neural network (PP-HFNN) to address these technical challenges while also alleviating privacy concerns. The network is trained with a two-stage optimization algorithm, and the parameters at low levels of the hierarchy are learned with a scheme based on the well-known alternating direction method of multipliers, which does not reveal local data to other agents. Coordination at high levels of the hierarchy is handled by the alternating optimization method, which converges very quickly. The entire training procedure is scalable, fast and does not suffer from gradient vanishing problems like the methods based on back-propagation. Comprehensive simulations conducted on both regression and classification tasks demonstrate the effectiveness of the proposed model.
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- 2022
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25. Toward multi-target self-organizing pursuit in a partially observable Markov game
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Sun, Lijun, Chang, Yu-Cheng, Lyu, Chao, Shi, Ye, Shi, Yuhui, and Lin, Chin-Teng
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Computer Science - Multiagent Systems ,Computer Science - Artificial Intelligence - Abstract
The multiple-target self-organizing pursuit (SOP) problem has wide applications and has been considered a challenging self-organization game for distributed systems, in which intelligent agents cooperatively pursue multiple dynamic targets with partial observations. This work proposes a framework for decentralized multi-agent systems to improve the implicit coordination capabilities in search and pursuit. We model a self-organizing system as a partially observable Markov game (POMG) featured by large-scale, decentralization, partial observation, and noncommunication. The proposed distributed algorithm: fuzzy self-organizing cooperative coevolution (FSC2) is then leveraged to resolve the three challenges in multi-target SOP: distributed self-organizing search (SOS), distributed task allocation, and distributed single-target pursuit. FSC2 includes a coordinated multi-agent deep reinforcement learning (MARL) method that enables homogeneous agents to learn natural SOS patterns. Additionally, we propose a fuzzy-based distributed task allocation method, which locally decomposes multi-target SOP into several single-target pursuit problems. The cooperative coevolution principle is employed to coordinate distributed pursuers for each single-target pursuit problem. Therefore, the uncertainties of inherent partial observation and distributed decision-making in the POMG can be alleviated. The experimental results demonstrate that by decomposing the SOP task, FSC2 achieves superior performance compared with other implicit coordination policies fully trained by general MARL algorithms. The scalability of FSC2 is proved that up to 2048 FSC2 agents perform efficient multi-target SOP with almost 100 percent capture rates. Empirical analyses and ablation studies verify the interpretability, rationality, and effectiveness of component algorithms in FSC2.
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- 2022
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26. Air plasma-treated titanium dioxide nanotubes for enhanced photoelectrochemical and photocatalytic properties
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Chang, Yu-Cheng, Lai, Pin-Ru, Yang, Jason Hsiao Chun, and Hayashi, Nobuya
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- 2024
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27. Construction of In2S3–In(OH)3–ZnS nanofibers for boosting photocatalytic hydrogen evolution
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Chang, Yu-Cheng, Syu, Shih-Yue, and Hsu, Po-Chun
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- 2024
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28. Investigation of Weighted Least Squares Methods for Multitarget Tracking with Multisensor Data Fusion
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Chang, Dah-Chung and Chang, Yu-Cheng
- Published
- 2023
- Full Text
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29. Radio frequency Coulomb blockade thermometry
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Blanchet, Florian, Chang, Yu-Cheng, Karimi, Bayan, Peltonen, Joonas T., and Pekola, Jukka P.
- Subjects
Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
We present a scheme and demonstrate measurements of a Coulomb blockade thermometer (CBT) in a microwave transmission setup. The sensor is embedded in an $LCR$ resonator, where $R$ is determined by the conductance of the junction array of the CBT. A transmission measurement yields a signal that is directly proportional to the conductance of the CBT, thus enabling the calibration-free operation of the thermometer. This is verified by measuring an identical sensor simultaneously in the usual dc setup. The important advantage of the rf measurement is its speed: the whole bias dependence of the CBT conductance can now be measured in a time of about 100\,ms, which is thousand times faster than in a standard dc measurement. The achieved noise equivalent temperature of this first rf primary measurement is about 1 mK/$\sqrt{{\rm Hz}}$ at the bath temperature $T=200\,$mK.
- Published
- 2021
30. A Cooper-Pair Box Coupled to Two Resonators: An Architecture for a Quantum Refrigerator
- Author
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Guthrie, Andrew, Satrya, Christoforus Dimas, Chang, Yu-Cheng, Menczel, Paul, Nori, Franco, and Pekola, Jukka P.
- Subjects
Quantum Physics ,Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
Superconducting circuits present a promising platform with which to realize a quantum refrigerator. Motivated by this, we fabricate and perform spectroscopy of a gated Cooper-pair box, capacitively coupled to two superconducting coplanar waveguide resonators with different frequencies. We experimentally demonstrate the strong coupling of a charge qubit to two superconducting resonators, with the ability to perform voltage driving of the qubit at GHz frequencies. We go on to discuss how the measured device could be modified to operate as a cyclic quantum refrigerator by terminating the resonators with normal-metal resistors acting as heat baths.
- Published
- 2021
- Full Text
- View/download PDF
31. Effects of corticosteroids on severe community-acquired pneumonia: a closer look at the evidence
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Chiang, Cho-Han, See, Xin Ya, Wang, Tsu Hsien, Chang, Yu-Cheng, Lo, Jui-En, Liu, Wei-Tao, Choo, Cheryn Yu Wei, Chiang, Cho-Hsien, Hsia, Yuan Ping, and Chiang, Cho-Hung
- Published
- 2023
- Full Text
- View/download PDF
32. Improving CCA Algorithms on SSVEP Classification with Reinforcement Learning Based Temporal Filtering
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Ou, Liang, primary, Do, Thomas, additional, Tran, Xuan-The, additional, Leong, Daniel, additional, Chang, Yu-Cheng, additional, Wang, Yu-Kai, additional, and Lin, Chin-Teng, additional
- Published
- 2023
- Full Text
- View/download PDF
33. Robust strong coupling architecture in circuit quantum electrodynamics
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Upadhyay, Rishabh, Thomas, George, Chang, Yu-Cheng, Golubev, Dmitry S., Guthrie, Andrew, Gubaydullin, Azat, Peltonen, Joonas T., and Pekola, Jukka P.
- Subjects
Quantum Physics ,Condensed Matter - Superconductivity - Abstract
We report on a robust method to achieve strong coupling between a superconducting flux qubit and a high-quality quarter-wavelength coplanar waveguide resonator. We demonstrate the progression from the strong to ultrastrong coupling regime by varying the length of a shared inductive coupling element, ultimately achieving a qubit-resonator coupling strength of 655 MHz, $10\%$ of the resonator frequency. We derive an analytical expression for the coupling strength in terms of circuit parameters and also discuss the maximum achievable coupling within this framework. We experimentally characterize flux qubits coupled to superconducting resonators using one and two-tone spectroscopy methods, demonstrating excellent agreement with the proposed theoretical model., Comment: 9 pages, 6 figures
- Published
- 2021
- Full Text
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34. Effect of metformin on outcomes of patients treated with immune checkpoint inhibitors: a retrospective cohort study
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Chiang, Cho-Han, Chen, Yuan-Jen, Chiang, Cho-Hsien, Chen, Cheng-Ying, Chang, Yu-Cheng, Wang, Shih-Syuan, See, Xin Ya, Horng, Chuan-Sheng, Peng, Chun-Yu, Hsia, Yuan Ping, Peng, Cheng-Ming, and Chiang, Cho-Hung
- Published
- 2023
- Full Text
- View/download PDF
35. Defect-synergetic effect enhanced CO2 photoreduction efficiency of TiO2 nanostructures with Fe dopants
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Lo, An-Ya, Wang, Chih-Chiang, Huang, Juifa, Chung, Yi-Chen, and Chang, Yu-Cheng
- Published
- 2024
- Full Text
- View/download PDF
36. PbS dendrites/graphene membranes as efficient solar steam generators
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Chang, Chi-Jung, Pundi, Arul, Hsieh, Shao-Ching, Tsay, Chien-Yie, Chang, Yu-Cheng, and Wang, Chih-Feng
- Published
- 2024
- Full Text
- View/download PDF
37. $S^3$: Learnable Sparse Signal Superdensity for Guided Depth Estimation
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Huang, Yu-Kai, Liu, Yueh-Cheng, Wu, Tsung-Han, Su, Hung-Ting, Chang, Yu-Cheng, Tsou, Tsung-Lin, Wang, Yu-An, and Hsu, Winston H.
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
Dense depth estimation plays a key role in multiple applications such as robotics, 3D reconstruction, and augmented reality. While sparse signal, e.g., LiDAR and Radar, has been leveraged as guidance for enhancing dense depth estimation, the improvement is limited due to its low density and imbalanced distribution. To maximize the utility from the sparse source, we propose $S^3$ technique, which expands the depth value from sparse cues while estimating the confidence of expanded region. The proposed $S^3$ can be applied to various guided depth estimation approaches and trained end-to-end at different stages, including input, cost volume and output. Extensive experiments demonstrate the effectiveness, robustness, and flexibility of the $S^3$ technique on LiDAR and Radar signal., Comment: CVPR 2021
- Published
- 2021
38. Dual-Awareness Attention for Few-Shot Object Detection
- Author
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Chen, Tung-I, Liu, Yueh-Cheng, Su, Hung-Ting, Chang, Yu-Cheng, Lin, Yu-Hsiang, Yeh, Jia-Fong, Chen, Wen-Chin, and Hsu, Winston H.
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
While recent progress has significantly boosted few-shot classification (FSC) performance, few-shot object detection (FSOD) remains challenging for modern learning systems. Existing FSOD systems follow FSC approaches, ignoring critical issues such as spatial variability and uncertain representations, and consequently result in low performance. Observing this, we propose a novel \textbf{Dual-Awareness Attention (DAnA)} mechanism that enables networks to adaptively interpret the given support images. DAnA transforms support images into \textbf{query-position-aware} (QPA) features, guiding detection networks precisely by assigning customized support information to each local region of the query. In addition, the proposed DAnA component is flexible and adaptable to multiple existing object detection frameworks. By adopting DAnA, conventional object detection networks, Faster R-CNN and RetinaNet, which are not designed explicitly for few-shot learning, reach state-of-the-art performance in FSOD tasks. In comparison with previous methods, our model significantly increases the performance by 47\% (+6.9 AP), showing remarkable ability under various evaluation settings.
- Published
- 2021
39. Situation and Behavior Understanding by Trope Detection on Films
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Chang, Chen-Hsi, Su, Hung-Ting, Hsu, Jui-heng, Wang, Yu-Siang, Chang, Yu-Cheng, Liu, Zhe Yu, Chang, Ya-Liang, Cheng, Wen-Feng, Wang, Ke-Jyun, and Hsu, Winston H.
- Subjects
Computer Science - Computation and Language ,Computer Science - Artificial Intelligence - Abstract
The human ability of deep cognitive skills are crucial for the development of various real-world applications that process diverse and abundant user generated input. While recent progress of deep learning and natural language processing have enabled learning system to reach human performance on some benchmarks requiring shallow semantics, such human ability still remains challenging for even modern contextual embedding models, as pointed out by many recent studies. Existing machine comprehension datasets assume sentence-level input, lack of casual or motivational inferences, or could be answered with question-answer bias. Here, we present a challenging novel task, trope detection on films, in an effort to create a situation and behavior understanding for machines. Tropes are storytelling devices that are frequently used as ingredients in recipes for creative works. Comparing to existing movie tag prediction tasks, tropes are more sophisticated as they can vary widely, from a moral concept to a series of circumstances, and embedded with motivations and cause-and-effects. We introduce a new dataset, Tropes in Movie Synopses (TiMoS), with 5623 movie synopses and 95 different tropes collecting from a Wikipedia-style database, TVTropes. We present a multi-stream comprehension network (MulCom) leveraging multi-level attention of words, sentences, and role relations. Experimental result demonstrates that modern models including BERT contextual embedding, movie tag prediction systems, and relational networks, perform at most 37% of human performance (23.97/64.87) in terms of F1 score. Our MulCom outperforms all modern baselines, by 1.5 to 5.0 F1 score and 1.5 to 3.0 mean of average precision (mAP) score. We also provide a detailed analysis and human evaluation to pave ways for future research., Comment: WWW 2021. The first two authors contributed equally to this work
- Published
- 2021
40. End-to-End Video Question-Answer Generation with Generator-Pretester Network
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Su, Hung-Ting, Chang, Chen-Hsi, Shen, Po-Wei, Wang, Yu-Siang, Chang, Ya-Liang, Chang, Yu-Cheng, Cheng, Pu-Jen, and Hsu, Winston H.
- Subjects
Computer Science - Multimedia ,Computer Science - Computation and Language ,Computer Science - Computer Vision and Pattern Recognition - Abstract
We study a novel task, Video Question-Answer Generation (VQAG), for challenging Video Question Answering (Video QA) task in multimedia. Due to expensive data annotation costs, many widely used, large-scale Video QA datasets such as Video-QA, MSVD-QA and MSRVTT-QA are automatically annotated using Caption Question Generation (CapQG) which inputs captions instead of the video itself. As captions neither fully represent a video, nor are they always practically available, it is crucial to generate question-answer pairs based on a video via Video Question-Answer Generation (VQAG). Existing video-to-text (V2T) approaches, despite taking a video as the input, only generate a question alone. In this work, we propose a novel model Generator-Pretester Network that focuses on two components: (1) The Joint Question-Answer Generator (JQAG) which generates a question with its corresponding answer to allow Video Question "Answering" training. (2) The Pretester (PT) verifies a generated question by trying to answer it and checks the pretested answer with both the model's proposed answer and the ground truth answer. We evaluate our system with the only two available large-scale human-annotated Video QA datasets and achieves state-of-the-art question generation performances. Furthermore, using our generated QA pairs only on the Video QA task, we can surpass some supervised baselines. We apply our generated questions to Video QA applications and surpasses some supervised baselines using generated questions only. As a pre-training strategy, we outperform both CapQG and transfer learning approaches when employing semi-supervised (20%) or fully supervised learning with annotated data. These experimental results suggest the novel perspectives for Video QA training., Comment: Accepted to TCSVT
- Published
- 2021
41. Computational Intelligence and AI-FML Experience Model for Pre-university Student Learning and Practice
- Author
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Lee, Chang-Shing, Wang, Mei-Hui, Chang, Rin-Pin, Liu, Hsiao-Chi, Chiu, Szu-Chi, Chang, Yu-Cheng, Lin, Lu-An, Chen, Shen-Chien, Howlett, Robert J., Series Editor, Jain, Lakhmi C., Series Editor, Kondo, Kazuhiro, editor, Horng, Mong-Fong, editor, Pan, Jeng-Shyang, editor, and Hu, Pei, editor
- Published
- 2023
- Full Text
- View/download PDF
42. One-pot microwave-assisted synthesis of In2S3/In2O3 nanosheets as highly active visible light photocatalysts for seawater splitting
- Author
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Lin, Ying-Ru, Chang, Yu-Cheng, and Ko, Fu-Hsiang
- Published
- 2024
- Full Text
- View/download PDF
43. Controllable medium layer of ZnS or CdS nanostructures as cocatalyst onto CuO-ZnO heterojunction for enhancing photocatalytic activity
- Author
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Chang, Yu-Cheng, Guo, Jin-You, Chen, Chin-Yi, and Tsay, Chien-Yie
- Published
- 2024
- Full Text
- View/download PDF
44. Resveratrol attenuates advanced glycation end product-induced senescence and inflammation in human gingival fibroblasts
- Author
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Huang, Chao-Yen, Chen, Szu-Han, Lin, Taichen, Liao, Yi-Wen, Chang, Yu-Cheng, Chen, Chun-Cheng, Yu, Cheng-Chia, and Chen, Chun-Jung
- Published
- 2024
- Full Text
- View/download PDF
45. Electron-phonon coupling of epigraphene at millikelvin temperatures
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Karimi, Bayan, He, Hans, Chang, Yu-Cheng, Wang, Libin, Pekola, Jukka P., Yakimova, Rositsa, Shetty, Naveen, Peltonen, Joonas T., Lara-Avila, Samuel, and Kubatkin, Sergey
- Subjects
Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
We investigate the basic charge and heat transport properties of charge neutral epigraphene at sub-kelvin temperatures, demonstrating nearly logarithmic dependence of electrical conductivity over more than two decades in temperature. Using graphene's sheet conductance as in-situ thermometer, we present a measurement of electron-phonon heat transport at mK temperatures and show that it obeys the $T^4$ dependence characteristic for clean two-dimensional conductor. Based on our measurement we predict the noise-equivalent power of $\sim 10^{-22}~{\rm W}/\sqrt{{\rm Hz}}$ of epigraphene bolometer at the low end of achievable temperatures.
- Published
- 2020
46. Efficient and Phase-aware Video Super-resolution for Cardiac MRI
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Lin, Jhih-Yuan, Chang, Yu-Cheng, and Hsu, Winston H.
- Subjects
Electrical Engineering and Systems Science - Image and Video Processing ,Computer Science - Computer Vision and Pattern Recognition - Abstract
Cardiac Magnetic Resonance Imaging (CMR) is widely used since it can illustrate the structure and function of heart in a non-invasive and painless way. However, it is time-consuming and high-cost to acquire the high-quality scans due to the hardware limitation. To this end, we propose a novel end-to-end trainable network to solve CMR video super-resolution problem without the hardware upgrade and the scanning protocol modifications. We incorporate the cardiac knowledge into our model to assist in utilizing the temporal information. Specifically, we formulate the cardiac knowledge as the periodic function, which is tailored to meet the cyclic characteristic of CMR. In addition, the proposed residual of residual learning scheme facilitates the network to learn the LR-HR mapping in a progressive refinement fashion. This mechanism enables the network to have the adaptive capability by adjusting refinement iterations depending on the difficulty of the task. Extensive experimental results on large-scale datasets demonstrate the superiority of the proposed method compared with numerous state-of-the-art methods., Comment: MICCAI 2020
- Published
- 2020
47. Toward multi-target self-organizing pursuit in a partially observable Markov game
- Author
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Sun, Lijun, Chang, Yu-Cheng, Lyu, Chao, Shi, Ye, Shi, Yuhui, and Lin, Chin-Teng
- Published
- 2023
- Full Text
- View/download PDF
48. WS2–TiO2 hetero-photocatalysts for efficient hydrogen evolution via plasmon-induced resonance energy transfer
- Author
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Lyu, Lian-Ming, Hsiao, Kai-Yuan, Lin, Cheng-Yi, Tseng, Yu-Han, Chang, Yu-Cheng, and Lu, Ming-Yen
- Published
- 2023
- Full Text
- View/download PDF
49. Norisoboldine exerts antiallergic effects on IgE/ovalbumin-induced allergic asthma and attenuates FcεRI-mediated mast cell activation
- Author
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Chang, Jer-Hwa, Chuang, Hsiao-Chi, Fan, Chia-Kwung, Hou, Tsung-Yun, Chang, Yu-Cheng, and Lee, Yueh-Lun
- Published
- 2023
- Full Text
- View/download PDF
50. Utilization of the Superconducting Transition for Characterizing Low-Quality-Factor Superconducting Resonators
- Author
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Chang, Yu-Cheng, Karimi, Bayan, Senior, Jorden, Ronzani, Alberto, Peltonen, Joonas T., Goan, Hsi-Sheng, Chen, Chii-Dong, and Pekola, Jukka P.
- Subjects
Condensed Matter - Superconductivity - Abstract
Characterizing superconducting microwave resonators with highly dissipative elements is a technical challenge, but a requirement for implementing and understanding the operation of hybrid quantum devices involving dissipative elements, e.g. for thermal engineering and detection. We present experiments on $\lambda/4$ superconducting niobium coplanar waveguide (CPW) resonators, terminating at the antinode by a dissipative copper microstrip via aluminum leads, such that the resonator response is difficult to measure in a typical microwave environment. By measuring the transmission both above and below the superconducting transition of aluminum, we are able to isolate the resonance. We then experimentally verify this method with copper microstrips of increasing thicknesses, from 50 nm to 150 nm, and measure quality factors in the range of $10\sim67$ in a consistent way.
- Published
- 2019
- Full Text
- View/download PDF
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