40,071 results on '"Liu, PENG"'
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2. Exploring Musical Narratology: The Romeo and Juliet Myth in Music by Małgorzata Pawłowska (review)
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Liu, Peng
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- 2022
- Full Text
- View/download PDF
3. How Privacy-Savvy Are Large Language Models? A Case Study on Compliance and Privacy Technical Review
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Zhu, Xichou, Liu, Yang, Shen, Zhou, Liu, Yi, Li, Min, Chen, Yujun, John, Benzi, Ma, Zhenzhen, Hu, Tao, Yang, Bolong, Wang, Manman, Xie, Zongxing, Liu, Peng, Cai, Dan, and Wang, Junhui
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Computer Science - Computation and Language - Abstract
The recent advances in large language models (LLMs) have significantly expanded their applications across various fields such as language generation, summarization, and complex question answering. However, their application to privacy compliance and technical privacy reviews remains under-explored, raising critical concerns about their ability to adhere to global privacy standards and protect sensitive user data. This paper seeks to address this gap by providing a comprehensive case study evaluating LLMs' performance in privacy-related tasks such as privacy information extraction (PIE), legal and regulatory key point detection (KPD), and question answering (QA) with respect to privacy policies and data protection regulations. We introduce a Privacy Technical Review (PTR) framework, highlighting its role in mitigating privacy risks during the software development life-cycle. Through an empirical assessment, we investigate the capacity of several prominent LLMs, including BERT, GPT-3.5, GPT-4, and custom models, in executing privacy compliance checks and technical privacy reviews. Our experiments benchmark the models across multiple dimensions, focusing on their precision, recall, and F1-scores in extracting privacy-sensitive information and detecting key regulatory compliance points. While LLMs show promise in automating privacy reviews and identifying regulatory discrepancies, significant gaps persist in their ability to fully comply with evolving legal standards. We provide actionable recommendations for enhancing LLMs' capabilities in privacy compliance, emphasizing the need for robust model improvements and better integration with legal and regulatory requirements. This study underscores the growing importance of developing privacy-aware LLMs that can both support businesses in compliance efforts and safeguard user privacy rights., Comment: 8 pages, 4 figures
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- 2024
4. Joint Offloading and Beamforming Design in Integrating Sensing, Communication, and Computing Systems: A Distributed Approach
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Liu, Peng, Fei, Zesong, Wang, Xinyi, Huang, Jingxuan, Hu, Jie, and Zhang, J. Andrew
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Electrical Engineering and Systems Science - Signal Processing - Abstract
When applying integrated sensing and communications (ISAC) in future mobile networks, many sensing tasks have low latency requirements, preferably being implemented at terminals. However, terminals often have limited computing capabilities and energy supply. In this paper, we investigate the effectiveness of leveraging the advanced computing capabilities of mobile edge computing (MEC) servers and the cloud server to address the sensing tasks of ISAC terminals. Specifically, we propose a novel three-tier integrated sensing, communication, and computing (ISCC) framework composed of one cloud server, multiple MEC servers, and multiple terminals, where the terminals can optionally offload sensing data to the MEC server or the cloud server. The offload message is sent via the ISAC waveform, whose echo is used for sensing. We jointly optimize the computation offloading and beamforming strategies to minimize the average execution latency while satisfying sensing requirements. In particular, we propose a low-complexity distributed algorithm to solve the problem. Firstly, we use the alternating direction method of multipliers (ADMM) and derive the closed-form solution for offloading decision variables. Subsequently, we convert the beamforming optimization sub-problem into a weighted minimum mean-square error (WMMSE) problem and propose a fractional programming based algorithm. Numerical results demonstrate that the proposed ISCC framework and distributed algorithm significantly reduce the execution latency and the energy consumption of sensing tasks at a lower computational complexity compared to existing schemes., Comment: 15 pages, 12 figures, submitted to IEEE journals for possible publication
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- 2024
5. Bayesian Inference General Procedures for A Single-subject Test Study
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Li, Jie, Green, Gary, Carr, Sarah J. A., Liu, Peng, and Zhang, Jian
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Statistics - Applications - Abstract
This paper presents a Bayesian Inference General Procedures for A Single-Subject Test (BIGPAST), designed to mitigate the effects of skewness. BIGPAST operates under the null hypothesis that the single-subject follows the same distribution as the control group. We assess BIGPAST's performance against other methods through a series of simulation studies. The results demonstrate that BIGPAST is robust against deviations from normality and outperforms the existing approaches in terms of accuracy. This is because BIGPAST can effectively reduce model misspecification errors under the skewed Student's \( t \) assumption. We apply BIGPAST to a MEG dataset consisting of an individual with mild traumatic brain injury and an age and gender-matched control group, demonstrating its effectiveness in detecting abnormalities in the single-subject., Comment: 33 pages, 11 figures and 9 tables
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- 2024
6. Hide Your Malicious Goal Into Benign Narratives: Jailbreak Large Language Models through Neural Carrier Articles
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Wang, Zhilong, Wang, Haizhou, Luo, Nanqing, Zhang, Lan, Sun, Xiaoyan, Cao, Yebo, and Liu, Peng
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Computer Science - Cryptography and Security ,Computer Science - Artificial Intelligence - Abstract
Jailbreak attacks on Language Model Models (LLMs) entail crafting prompts aimed at exploiting the models to generate malicious content. This paper proposes a new type of jailbreak attacks which shift the attention of the LLM by inserting a prohibited query into a carrier article. The proposed attack leverage the knowledge graph and a composer LLM to automatically generating a carrier article that is similar to the topic of the prohibited query but does not violate LLM's safeguards. By inserting the malicious query to the carrier article, the assembled attack payload can successfully jailbreak LLM. To evaluate the effectiveness of our method, we leverage 4 popular categories of ``harmful behaviors'' adopted by related researches to attack 6 popular LLMs. Our experiment results show that the proposed attacking method can successfully jailbreak all the target LLMs which high success rate, except for Claude-3.
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- 2024
7. Beam Prediction based on Large Language Models
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Sheng, Yucheng, Huang, Kai, Liang, Le, Liu, Peng, Jin, Shi, and Li, Geoffrey Ye
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Computer Science - Machine Learning ,Computer Science - Artificial Intelligence - Abstract
Millimeter-wave (mmWave) communication is promising for next-generation wireless networks but suffers from significant path loss, requiring extensive antenna arrays and frequent beam training. Traditional deep learning models, such as long short-term memory (LSTM), enhance beam tracking accuracy however are limited by poor robustness and generalization. In this letter, we use large language models (LLMs) to improve the robustness of beam prediction. By converting time series data into text-based representations and employing the Prompt-as-Prefix (PaP) technique for contextual enrichment, our approach unleashes the strength of LLMs for time series forecasting. Simulation results demonstrate that our LLM-based method offers superior robustness and generalization compared to LSTM-based models, showcasing the potential of LLMs in wireless communications.
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- 2024
8. Theorem-Carrying-Transaction: Runtime Certification to Ensure Safety for Smart Contract Transactions
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Bjørner, Nikolaj S., Chen, Ashley J., Chen, Shuo, Chen, Yang, Guo, Zhongxin, Hsu, Tzu-Han, Liu, Peng, and Luo, Nanqing
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Computer Science - Cryptography and Security ,Computer Science - Programming Languages - Abstract
Security bugs and trapdoors in smart contracts have been impacting the Ethereum community since its inception. Conceptually, the 1.45-million Ethereum's contracts form a single "gigantic program" whose behaviors are determined by the complex reference-topology between the contracts. Can the Ethereum community be assured that this gigantic program conforms to its design-level safety properties, despite unforeseeable code-level intricacies? Static code verification is inadequate due to the program's gigantic scale and high polymorphism. In this paper, we present a viable technological roadmap for the community toward this ambitious goal. Our technology, called Theorem-Carrying-Transaction (TCT), combines the benefits of concrete execution and symbolic proofs. Under the TCT protocol, every transaction carries a theorem that proves its adherence to the specified properties in the invoked contracts, and the runtime system checks the theorem before executing the transaction. Once a property is specified in a contract, it can be treated confidently as an unconditional guarantee made by the contract. As case studies, we demonstrate that TCT secures token contracts without foreseeing code-level intricacies like integer overflow and reentrancy. TCT is also successfully applied to a Uniswap codebase, showcasing a complex decentralized finance (DeFi) scenario. Our prototype incurs a negligible runtime overhead, two orders of magnitude lower than a state-of-the-art approach.
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- 2024
9. Risk sharing with Lambda value at risk under heterogeneous beliefs
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Liu, Peng, Tsanakas, Andreas, and Wei, Yunran
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Quantitative Finance - Risk Management ,91B05 - Abstract
In this paper, we study the risk sharing problem among multiple agents using Lambda value at risk as their preferences under heterogenous beliefs, where the beliefs are represented by several probability measures. We obtain semi-explicit formulas for the inf-convolution of multiple Lambda value at risk under heterogenous beliefs and the explicit forms of the corresponding optimal allocations. To show the interplay among the beliefs, we consider three cases: homogeneous beliefs, conditional beliefs and absolutely continuous beliefs. For those cases, we find more explicit expressions for the inf-convolution, showing the influence of the relation of the beliefs on the inf-convolution. Moreover, we consider the inf-convolution of one Lambda value at risk and a general risk measure, including expected utility, distortion risk measures and Lambda value at risk as special cases, with different beliefs. The expression of the inf-convolution and the form of the optimal allocation are obtained. Finally, we discuss the risk sharing for another definition of Lambda value at risk., Comment: 31 pages
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- 2024
10. Using LLMs to Automate Threat Intelligence Analysis Workflows in Security Operation Centers
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Tseng, PeiYu, Yeh, ZihDwo, Dai, Xushu, and Liu, Peng
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Computer Science - Cryptography and Security - Abstract
SIEM systems are prevalent and play a critical role in a variety of analyst workflows in Security Operation Centers. However, modern SIEMs face a big challenge: they still cannot relieve analysts from the repetitive tasks involved in analyzing CTI (Cyber Threat Intelligence) reports written in natural languages. This project aims to develop an AI agent to replace the labor intensive repetitive tasks involved in analyzing CTI reports. The agent exploits the revolutionary capabilities of LLMs (e.g., GPT-4), but it does not require any human intervention.
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- 2024
11. OmChat: A Recipe to Train Multimodal Language Models with Strong Long Context and Video Understanding
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Zhao, Tiancheng, Zhang, Qianqian, Lee, Kyusong, Liu, Peng, Zhang, Lu, Fang, Chunxin, Liao, Jiajia, Jiang, Kelei, Ma, Yibo, and Xu, Ruochen
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Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Computation and Language - Abstract
We introduce OmChat, a model designed to excel in handling long contexts and video understanding tasks. OmChat's new architecture standardizes how different visual inputs are processed, making it more efficient and adaptable. It uses a dynamic vision encoding process to effectively handle images of various resolutions, capturing fine details across a range of image qualities. OmChat utilizes an active progressive multimodal pretraining strategy, which gradually increases the model's capacity for long contexts and enhances its overall abilities. By selecting high-quality data during training, OmChat learns from the most relevant and informative data points. With support for a context length of up to 512K, OmChat demonstrates promising performance in tasks involving multiple images and videos, outperforming most open-source models in these benchmarks. Additionally, OmChat proposes a prompting strategy for unifying complex multimodal inputs including single image text, multi-image text and videos, and achieving competitive performance on single-image benchmarks. To further evaluate the model's capabilities, we proposed a benchmark dataset named Temporal Visual Needle in a Haystack. This dataset assesses OmChat's ability to comprehend temporal visual details within long videos. Our analysis highlights several key factors contributing to OmChat's success: support for any-aspect high image resolution, the active progressive pretraining strategy, and high-quality supervised fine-tuning datasets. This report provides a detailed overview of OmChat's capabilities and the strategies that enhance its performance in visual understanding., Comment: 14 pages
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- 2024
12. Joint State and Parameter Estimation Using the Partial Errors-in-Variables Principle
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Liu, Peng, Li, Kailai, Hendeby, Gustaf, and Gustafsson, Fredrik
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Electrical Engineering and Systems Science - Signal Processing - Abstract
This letter proposes a new method for joint state and parameter estimation in uncertain dynamical systems. We exploit the partial errors-in-variables (PEIV) principle and formulate a regression problem in the sense of weighted total least squares, where the uncertainty in the parameter prior is explicitly considered. Based thereon, the PEIV regression can be solved iteratively through the Kalman smoothing and the regularized least squares for estimating the state and the parameter, respectively. The simulations demonstrate improved accuracy of the proposed method compared to existing approaches, including the joint maximum a posterior-maximum likelihood, the expectation maximisation, and the augmented state extended Kalman smoother., Comment: 5 pages
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- 2024
13. Protecting the 'Stop Using My Data' Right through Blockchain-assisted Evidence Generation
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Zhang, Fan and Liu, Peng
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Computer Science - Cryptography and Security - Abstract
In order to provide personalized services to users, Internet-based platforms collect and utilize user-generated behavioral data. Although the 'stop using my data' right should be a fundamental data right, which allows individuals to request their personal data to be no longer utilized by online platforms, the existing preventive data protection measures (e.g., cryptographic data elimination, differential privacy) are unfortunately not applicable. This work aims to develop the first Evidence Generation Framework for deterring post-acquisition data right violations. We formulated the 'stop using my data' problem, which captures a vantage facet of the multi-faceted notion of 'right to be forgotten'. We designed and implemented the first blockchain-assisted system to generate evidence for deterring the violations of the 'stop using my data' right. Our system employs a novel two-stage evidence generation protocol whose efficacy is ensured by a newly proposed Lemma. To validate our framework, we conducted a case study on recommendation systems with systematic evaluation experiments using two real-world datasets: the measured success rate exceeds 99%.
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- 2024
14. Robust Lambda-quantiles and extreme probabilities
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Han, Xia and Liu, Peng
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Quantitative Finance - Mathematical Finance ,91G10 - Abstract
In this paper, we investigate the robust models for $\Lambda$-quantiles with partial information regarding the loss distribution, where $\Lambda$-quantiles extend the classical quantiles by replacing the fixed probability level with a probability/loss function $\Lambda$. We find that, under some assumptions, the robust $\Lambda$-quantiles equal the $\Lambda$-quantiles of the extreme probabilities. This finding allows us to obtain the robust $\Lambda$-quantiles by applying the results of robust quantiles in the literature. Our results are applied to uncertainty sets characterized by three different constraints respectively: moment constraints, probability distance constraints via Wasserstein metric, and marginal constraints in risk aggregation. We obtain some explicit expressions for robust $\Lambda$-quantiles by deriving the extreme probabilities for each uncertainty set. Those results are applied to optimal portfolio selection under model uncertainty., Comment: 30 pages
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- 2024
15. An Imitative Reinforcement Learning Framework for Autonomous Dogfight
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Li, Siyuan, Zuo, Rongchang, Liu, Peng, and Zhao, Yingnan
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Computer Science - Machine Learning ,Computer Science - Robotics - Abstract
Unmanned Combat Aerial Vehicle (UCAV) dogfight, which refers to a fight between two or more UCAVs usually at close quarters, plays a decisive role on the aerial battlefields. With the evolution of artificial intelligence, dogfight progressively transits towards intelligent and autonomous modes. However, the development of autonomous dogfight policy learning is hindered by challenges such as weak exploration capabilities, low learning efficiency, and unrealistic simulated environments. To overcome these challenges, this paper proposes a novel imitative reinforcement learning framework, which efficiently leverages expert data while enabling autonomous exploration. The proposed framework not only enhances learning efficiency through expert imitation, but also ensures adaptability to dynamic environments via autonomous exploration with reinforcement learning. Therefore, the proposed framework can learn a successful dogfight policy of 'pursuit-lock-launch' for UCAVs. To support data-driven learning, we establish a dogfight environment based on the Harfang3D sandbox, where we conduct extensive experiments. The results indicate that the proposed framework excels in multistage dogfight, significantly outperforms state-of-the-art reinforcement learning and imitation learning methods. Thanks to the ability of imitating experts and autonomous exploration, our framework can quickly learn the critical knowledge in complex aerial combat tasks, achieving up to a 100% success rate and demonstrating excellent robustness.
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- 2024
16. BrainFounder: Towards Brain Foundation Models for Neuroimage Analysis
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Cox, Joseph, Liu, Peng, Stolte, Skylar E., Yang, Yunchao, Liu, Kang, See, Kyle B., Ju, Huiwen, and Fang, Ruogu
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Electrical Engineering and Systems Science - Image and Video Processing ,Computer Science - Computer Vision and Pattern Recognition ,Quantitative Biology - Neurons and Cognition - Abstract
The burgeoning field of brain health research increasingly leverages artificial intelligence (AI) to interpret and analyze neurological data. This study introduces a novel approach towards the creation of medical foundation models by integrating a large-scale multi-modal magnetic resonance imaging (MRI) dataset derived from 41,400 participants in its own. Our method involves a novel two-stage pretraining approach using vision transformers. The first stage is dedicated to encoding anatomical structures in generally healthy brains, identifying key features such as shapes and sizes of different brain regions. The second stage concentrates on spatial information, encompassing aspects like location and the relative positioning of brain structures. We rigorously evaluate our model, BrainFounder, using the Brain Tumor Segmentation (BraTS) challenge and Anatomical Tracings of Lesions After Stroke v2.0 (ATLAS v2.0) datasets. BrainFounder demonstrates a significant performance gain, surpassing the achievements of the previous winning solutions using fully supervised learning. Our findings underscore the impact of scaling up both the complexity of the model and the volume of unlabeled training data derived from generally healthy brains, which enhances the accuracy and predictive capabilities of the model in complex neuroimaging tasks with MRI. The implications of this research provide transformative insights and practical applications in healthcare and make substantial steps towards the creation of foundation models for Medical AI. Our pretrained models and training code can be found at https://github.com/lab-smile/GatorBrain., Comment: 19 pages, 5 figures, to be published in Medical Image Analysis
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- 2024
17. A Study of the Latest Updates of the Readout System for the Hybird-Pixel Detector at HEPS
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Li, Hangxu, Zhang, Jie, Wei, Wei, Li, Zhenjie, Ji, Xiaolu, Zhang, Yan, Yang, Xuanzheng, Zhang, Shuihan, Ma, Xueke, Liu, Peng, Wang, Zheng, and Chen, Yuanbai
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Physics - Instrumentation and Detectors ,Electrical Engineering and Systems Science - Systems and Control - Abstract
The High Energy Photon Source (HEPS) represents a fourth-generation light source. This facility has made unprecedented advancements in accelerator technology, necessitating the development of new detectors to satisfy physical requirements such as single-photon resolution, large dynamic range, and high frame rates. Since 2016, the Institute of High Energy Physics has introduced the first user-experimental hybrid pixel detector, progressing to the fourth-generation million-pixel detector designed for challenging conditions, with the dual-threshold single-photon detector HEPS-Beijing PIXel (HEPS-BPIX) set as the next-generation target. HEPS-BPIX will employ the entirely new Application-Specific Integrated Circuit (ASIC) BP40 for pixel information readout. Data flow will be managed and controlled through readout electronics based on a two-tier Field-Programmable Gate Array (FPGA) system: the Front-End Electronics (FEE) and the Input-Output Board (IOB) handle the fan-out for 12 ASICs, and the u4FCP is tasked with processing serial data on high-speed links, transferring pixel-level data to the back-end RTM and uTCA chassis, or independently outputting through a network port, enabling remote control of the entire detector. The new HEPS-BPIX firmware has undergone a comprehensive redesign and update to meet the electronic characteristics of the new chip and to improve the overall performance of the detector. We provide an overview of the core subunits of HEPS-BPIX, emphasizing the readout system, evaluating the new hardware and firmware, and highlighting some of its innovative features and characteristics.
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- 2024
18. A general design method for ultra-long optical path length multipass matrix cells
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Gai, Yiyun, Li, Wenjin, Yi, Kaihao, Ou, Xue, Liu, Peng, and Zhou, Xin
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Physics - Optics - Abstract
For the first time, we propose a general design method for ultra-long optical path length (OPL) multipass matrix cells (MMCs) based on multi-cycle mode of two-sided field mirrors. The design idea of the dual circulation mode with two-sided field mirrors is elaborated in detail with the example of MMC based on dual Pickett Bradley White cell (PBWC), and the simple design methods of the other three MMCs based on the dual circulation mode of PBWC and Bernstein Herzberg White cell (BHWC) are given. Further, we propose a general design method for ultra-long OPL MMCs with multi-cycle mode by adding cyclic elements. The OPL of the MMCs designed by this method can reach the order of kilometers or even tens of kilometers. The novel MMCs have the advantages of simple structure, strong spot formation regularity, easy expansion, high mirror utilization ratio, high reuse times of spot spatial position, good stability and extremely high ratio of the optical path length to the volume (RLV). In order to evaluate the performance of the new MMCs, an open-path methane gas sensor with the MMC based on triple PBWC was constructed, which was used to continuously measure the methane in the laboratory, and the feasibility, effectiveness and practicability of the new design method were verified. The design method proposed in this paper provides a new idea for the design of multipass cell (MPC), and the new MMCs designed have great potential application value in the field of high-precision trace gas monitoring.
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- 2024
19. Preference Optimization for Molecule Synthesis with Conditional Residual Energy-based Models
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Liu, Songtao, Dai, Hanjun, Zhao, Yue, and Liu, Peng
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Computer Science - Machine Learning ,Quantitative Biology - Biomolecules - Abstract
Molecule synthesis through machine learning is one of the fundamental problems in drug discovery. Current data-driven strategies employ one-step retrosynthesis models and search algorithms to predict synthetic routes in a top-bottom manner. Despite their effective performance, these strategies face limitations in the molecule synthetic route generation due to a greedy selection of the next molecule set without any lookahead. Furthermore, existing strategies cannot control the generation of synthetic routes based on possible criteria such as material costs, yields, and step count. In this work, we propose a general and principled framework via conditional residual energy-based models (EBMs), that focus on the quality of the entire synthetic route based on the specific criteria. By incorporating an additional energy-based function into our probabilistic model, our proposed algorithm can enhance the quality of the most probable synthetic routes (with higher probabilities) generated by various strategies in a plug-and-play fashion. Extensive experiments demonstrate that our framework can consistently boost performance across various strategies and outperforms previous state-of-the-art top-1 accuracy by a margin of 2.5%. Code is available at https://github.com/SongtaoLiu0823/CREBM., Comment: Accepted by ICML 2024(Oral)
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- 2024
20. GANcrop: A Contrastive Defense Against Backdoor Attacks in Federated Learning
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Gan, Xiaoyun, Gan, Shanyu, Su, Taizhi, and Liu, Peng
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Computer Science - Cryptography and Security ,Computer Science - Artificial Intelligence ,Computer Science - Distributed, Parallel, and Cluster Computing - Abstract
With heightened awareness of data privacy protection, Federated Learning (FL) has attracted widespread attention as a privacy-preserving distributed machine learning method. However, the distributed nature of federated learning also provides opportunities for backdoor attacks, where attackers can guide the model to produce incorrect predictions without affecting the global model training process. This paper introduces a novel defense mechanism against backdoor attacks in federated learning, named GANcrop. This approach leverages contrastive learning to deeply explore the disparities between malicious and benign models for attack identification, followed by the utilization of Generative Adversarial Networks (GAN) to recover backdoor triggers and implement targeted mitigation strategies. Experimental findings demonstrate that GANcrop effectively safeguards against backdoor attacks, particularly in non-IID scenarios, while maintaining satisfactory model accuracy, showcasing its remarkable defensive efficacy and practical utility.
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- 2024
21. Enhancing User Interest based on Stream Clustering and Memory Networks in Large-Scale Recommender Systems
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Liu, Peng, Wang, Nian, Xu, Cong, Zhao, Ming, Wang, Bin, and Ren, Yi
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Computer Science - Information Retrieval ,Computer Science - Machine Learning - Abstract
Recommender Systems (RSs) provide personalized recommendation service based on user interest, which are widely used in various platforms. However, there are lots of users with sparse interest due to lacking consumption behaviors, which leads to poor recommendation results for them. This problem is widespread in large-scale RSs and is particularly difficult to address. To solve this problem, we propose a novel solution named User Interest Enhancement (UIE) which enhances user interest including user profile and user history behavior sequences using the enhancement vectors and personalized enhancement vector generated based on stream clustering and memory networks from different perspectives. UIE not only remarkably improves model performance on the users with sparse interest but also significantly enhance model performance on other users. UIE is an end-to-end solution which is easy to be implemented based on ranking model. Moreover, we expand our solution and apply similar methods to long-tail items, which also achieves excellent improvement. Furthermore, we conduct extensive offline and online experiments in a large-scale industrial RS. The results demonstrate that our model outperforms other models remarkably, especially for the users with sparse interest. Until now, UIE has been fully deployed in multiple large-scale RSs and achieved remarkable improvements.
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- 2024
22. Scaffold-BPE: Enhancing Byte Pair Encoding with Simple and Effective Scaffold Token Removal
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Lian, Haoran, Xiong, Yizhe, Niu, Jianwei, Mo, Shasha, Su, Zhenpeng, Lin, Zijia, Liu, Peng, Chen, Hui, and Ding, Guiguang
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Computer Science - Computation and Language - Abstract
Byte Pair Encoding (BPE) serves as a foundation method for text tokenization in the Natural Language Processing (NLP) field. Despite its wide adoption, the original BPE algorithm harbors an inherent flaw: it inadvertently introduces a frequency imbalance for tokens in the text corpus. Since BPE iteratively merges the most frequent token pair in the text corpus while keeping all tokens that have been merged in the vocabulary, it unavoidably holds tokens that primarily represent subwords of complete words and appear infrequently on their own in the text corpus. We term such tokens as Scaffold Tokens. Due to their infrequent appearance in the text corpus, Scaffold Tokens pose a learning imbalance issue for language models. To address that issue, we propose Scaffold-BPE, which incorporates a dynamic scaffold token removal mechanism by parameter-free, computation-light, and easy-to-implement modifications to the original BPE. This novel approach ensures the exclusion of low-frequency Scaffold Tokens from the token representations for the given texts, thereby mitigating the issue of frequency imbalance and facilitating model training. On extensive experiments across language modeling tasks and machine translation tasks, Scaffold-BPE consistently outperforms the original BPE, well demonstrating its effectiveness and superiority.
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- 2024
23. DesTest: A Decentralised Testing Architecture for Improving Data Accuracy of Blockchain Oracle
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Zeng, Xueying, Xian, Youquan, Li, Chunpei, Hu, Zhengdong, and Liu, Peng
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Computer Science - Cryptography and Security ,Computer Science - Distributed, Parallel, and Cluster Computing - Abstract
Blockchain technology ensures secure and trustworthy data flow between multiple participants on the chain, but interoperability of on-chain and off-chain data has always been a difficult problem that needs to be solved. To solve the problem that blockchain systems cannot access off-chain data, oracle is introduced. however, existing research mainly focuses on the consistency and integrity of data, but ignores the problem that oracle nodes may be externally attacked or provide false data for selfish motives, resulting in the unresolved problem of data accuracy. In this paper, we introduce a new decentralized testing architecture (DesTest) that aims to improve data accuracy. A blockchain oracle random secret testing mechanism is first proposed to enhance the monitoring and verification of nodes by introducing a dynamic anonymized question-verification committee. Based on this, a comprehensive evaluation incentive mechanism is designed to incentivize honest work performance by evaluating nodes based on their reputation scores. The simulation results show that we successfully reduced the discrete entropy value of the acquired data and the real value of the data by 61.4%.
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- 2024
24. Zero-shot High-fidelity and Pose-controllable Character Animation
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Zhu, Bingwen, Wang, Fanyi, Lu, Tianyi, Liu, Peng, Su, Jingwen, Liu, Jinxiu, Zhang, Yanhao, Wu, Zuxuan, Qi, Guo-Jun, and Jiang, Yu-Gang
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Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Artificial Intelligence - Abstract
Image-to-video (I2V) generation aims to create a video sequence from a single image, which requires high temporal coherence and visual fidelity. However, existing approaches suffer from inconsistency of character appearances and poor preservation of fine details. Moreover, they require a large amount of video data for training, which can be computationally demanding. To address these limitations, we propose PoseAnimate, a novel zero-shot I2V framework for character animation. PoseAnimate contains three key components: 1) a Pose-Aware Control Module (PACM) that incorporates diverse pose signals into text embeddings, to preserve character-independent content and maintain precise alignment of actions. 2) a Dual Consistency Attention Module (DCAM) that enhances temporal consistency and retains character identity and intricate background details. 3) a Mask-Guided Decoupling Module (MGDM) that refines distinct feature perception abilities, improving animation fidelity by decoupling the character and background. We also propose a Pose Alignment Transition Algorithm (PATA) to ensure smooth action transition. Extensive experiment results demonstrate that our approach outperforms the state-of-the-art training-based methods in terms of character consistency and detail fidelity. Moreover, it maintains a high level of temporal coherence throughout the generated animations., Comment: 10 pages, 5 figures
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- 2024
25. An Off-Policy Reinforcement Learning Algorithm Customized for Multi-Task Fusion in Large-Scale Recommender Systems
- Author
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Liu, Peng, Xu, Cong, Zhao, Ming, Zhu, Jiawei, Wang, Bin, and Ren, Yi
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Computer Science - Information Retrieval ,Computer Science - Machine Learning - Abstract
As the last critical stage of RSs, Multi-Task Fusion (MTF) is responsible for combining multiple scores outputted by Multi-Task Learning (MTL) into a final score to maximize user satisfaction, which determines the ultimate recommendation results. Recently, to optimize long-term user satisfaction within a recommendation session, Reinforcement Learning (RL) is used for MTF in the industry. However, the off-policy RL algorithms used for MTF so far have the following severe problems: 1) to avoid out-of-distribution (OOD) problem, their constraints are overly strict, which seriously damage their performance; 2) they are unaware of the exploration policy used for producing training data and never interact with real environment, so only suboptimal policy can be learned; 3) the traditional exploration policies are inefficient and hurt user experience. To solve the above problems, we propose a novel method named IntegratedRL-MTF customized for MTF in large-scale RSs. IntegratedRL-MTF integrates off-policy RL model with our online exploration policy to relax overstrict and complicated constraints, which significantly improves its performance. We also design an extremely efficient exploration policy, which eliminates low-value exploration space and focuses on exploring potential high-value state-action pairs. Moreover, we adopt progressive training mode to further enhance our model's performance with the help of our exploration policy. We conduct extensive offline and online experiments in the short video channel of Tencent News. The results demonstrate that our model outperforms other models remarkably. IntegratedRL-MTF has been fully deployed in our RS and other large-scale RSs in Tencent, which have achieved significant improvements.
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- 2024
26. Diagnosing Emergent Isotropy in Anisotropic Holographic Systems using Quantum Information Measures
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Chen, Chong-Ye, Li, Mu-Jing, Yang, Zhe, Jin, Da-Ming, and Liu, Peng
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High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
This study presents a comprehensive investigation of anisotropy in a holographic p-wave superconductor model, revealing novel insights into the behavior of quantum information measures in strongly coupled systems. Through rigorous semi-analytical methods, we uncover the existence of an isotropic point emerging at a critical temperature $T_{II}$, marking a significant transition in the system's anisotropic properties. We offer a systematic analysis of the mechanisms driving anisotropy and isotropy transitions, finding that this phenomenon is unique to the p-wave model and absent in other anisotropic systems like anisotropic axion models with metal-insulator transitions. We propose that the explicit component dependence of the vector field manifesting anisotropy is the key driver of the emergent isotropy. Our analysis of holographic entanglement entropy (HEE), entanglement wedge cross-section (EWCS), and butterfly velocity demonstrates their distinct sensitivities to bulk anisotropy, with EWCS and butterfly velocity emerging as superior probes for detecting the isotropic point., Comment: 37 pages, 15 figures, minor revision, ref and technical details added
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- 2024
27. LoopAnimate: Loopable Salient Object Animation
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Wang, Fanyi, Liu, Peng, Hu, Haotian, Meng, Dan, Su, Jingwen, Xu, Jinjin, Zhang, Yanhao, Ren, Xiaoming, and Zhang, Zhiwang
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Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Artificial Intelligence - Abstract
Research on diffusion model-based video generation has advanced rapidly. However, limitations in object fidelity and generation length hinder its practical applications. Additionally, specific domains like animated wallpapers require seamless looping, where the first and last frames of the video match seamlessly. To address these challenges, this paper proposes LoopAnimate, a novel method for generating videos with consistent start and end frames. To enhance object fidelity, we introduce a framework that decouples multi-level image appearance and textual semantic information. Building upon an image-to-image diffusion model, our approach incorporates both pixel-level and feature-level information from the input image, injecting image appearance and textual semantic embeddings at different positions of the diffusion model. Existing UNet-based video generation models require to input the entire videos during training to encode temporal and positional information at once. However, due to limitations in GPU memory, the number of frames is typically restricted to 16. To address this, this paper proposes a three-stage training strategy with progressively increasing frame numbers and reducing fine-tuning modules. Additionally, we introduce the Temporal E nhanced Motion Module(TEMM) to extend the capacity for encoding temporal and positional information up to 36 frames. The proposed LoopAnimate, which for the first time extends the single-pass generation length of UNet-based video generation models to 35 frames while maintaining high-quality video generation. Experiments demonstrate that LoopAnimate achieves state-of-the-art performance in both objective metrics, such as fidelity and temporal consistency, and subjective evaluation results.
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- 2024
28. Factor risk measures
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Assa, Hirbod and Liu, Peng
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Quantitative Finance - Mathematical Finance ,91G70, 91B05 - Abstract
This paper introduces and studies factor risk measures. While risk measures only rely on the distribution of a loss random variable, in many cases risk needs to be measured relative to some major factors. In this paper, we introduce a double-argument mapping as a risk measure to assess the risk relative to a vector of factors, called factor risk measure. The factor risk measure only depends on the joint distribution of the risk and the factors. A set of natural axioms are discussed, and particularly distortion, quantile, linear and coherent factor risk measures are introduced and characterized. Moreover, we introduce a large set of concrete factor risk measures and many of them are new to the literature, which are interpreted in the context of regulatory capital requirement. Finally, the distortion factor risk measures are applied in the risk-sharing problem and some numerical examples are presented to show the difference between the Value-at-Risk and the quantile factor risk measures., Comment: 31 pages
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- 2024
29. Probing Berry phase effect in topological surface states
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Bai, Ya, Jiang, Yang, Zheng, Wenyang, Chen, Jiayin, Wang, Shuo, Liu, Candong, Li, Ruxin, and Liu, Peng
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Physics - Optics - Abstract
We have observed the Berry phase effect associated with interband coherence in topological surface states (TSSs) using two-color high-harmonic spectroscopy. This Berry phase accumulates along the evolution path of strong field-driven election-hole quasiparticles in electronic bands with strong spin-orbit coupling. By introducing a secondary weak field, we perturb the evolution of Dirac fermions in TSSs and thus provide access to the Berry phase. We observe a significant shift in the oscillation phase of the even-order harmonics from the spectral interferogram. We reveal that such a modulation feature is linked to the geometric phase acquired in the nonperturbative dynamics of TSSs. Furthermore, we show that the overwhelming Berry phase effect can significantly deform the quantum paths of electron-hole pairs, thus enhancing the ability to harness electron spin using lightwaves in quantum materials with strong spin-orbit interactions., Comment: 16 pages, 4 figures
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- 2024
30. AUEditNet: Dual-Branch Facial Action Unit Intensity Manipulation with Implicit Disentanglement
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Jin, Shiwei, Wang, Zhen, Wang, Lei, Liu, Peng, Bi, Ning, and Nguyen, Truong
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Computer Science - Computer Vision and Pattern Recognition - Abstract
Facial action unit (AU) intensity plays a pivotal role in quantifying fine-grained expression behaviors, which is an effective condition for facial expression manipulation. However, publicly available datasets containing intensity annotations for multiple AUs remain severely limited, often featuring a restricted number of subjects. This limitation places challenges to the AU intensity manipulation in images due to disentanglement issues, leading researchers to resort to other large datasets with pretrained AU intensity estimators for pseudo labels. In addressing this constraint and fully leveraging manual annotations of AU intensities for precise manipulation, we introduce AUEditNet. Our proposed model achieves impressive intensity manipulation across 12 AUs, trained effectively with only 18 subjects. Utilizing a dual-branch architecture, our approach achieves comprehensive disentanglement of facial attributes and identity without necessitating additional loss functions or implementing with large batch sizes. This approach offers a potential solution to achieve desired facial attribute editing despite the dataset's limited subject count. Our experiments demonstrate AUEditNet's superior accuracy in editing AU intensities, affirming its capability in disentangling facial attributes and identity within a limited subject pool. AUEditNet allows conditioning by either intensity values or target images, eliminating the need for constructing AU combinations for specific facial expression synthesis. Moreover, AU intensity estimation, as a downstream task, validates the consistency between real and edited images, confirming the effectiveness of our proposed AU intensity manipulation method.
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- 2024
31. Hidden You Malicious Goal Into Benign Narratives: Jailbreak Large Language Models through Logic Chain Injection
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Wang, Zhilong, Cao, Yebo, and Liu, Peng
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Computer Science - Cryptography and Security ,Computer Science - Artificial Intelligence - Abstract
Jailbreak attacks on Language Model Models (LLMs) entail crafting prompts aimed at exploiting the models to generate malicious content. Existing jailbreak attacks can successfully deceive the LLMs, however they cannot deceive the human. This paper proposes a new type of jailbreak attacks which can deceive both the LLMs and human (i.e., security analyst). The key insight of our idea is borrowed from the social psychology - that is human are easily deceived if the lie is hidden in truth. Based on this insight, we proposed the logic-chain injection attacks to inject malicious intention into benign truth. Logic-chain injection attack firstly dissembles its malicious target into a chain of benign narrations, and then distribute narrations into a related benign article, with undoubted facts. In this way, newly generate prompt cannot only deceive the LLMs, but also deceive human.
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- 2024
32. Understanding Language Modeling Paradigm Adaptations in Recommender Systems: Lessons Learned and Open Challenges
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Zhang, Lemei, Liu, Peng, Deldjoo, Yashar, Zheng, Yong, and Gulla, Jon Atle
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Computer Science - Information Retrieval - Abstract
The emergence of Large Language Models (LLMs) has achieved tremendous success in the field of Natural Language Processing owing to diverse training paradigms that empower LLMs to effectively capture intricate linguistic patterns and semantic representations. In particular, the recent "pre-train, prompt and predict" training paradigm has attracted significant attention as an approach for learning generalizable models with limited labeled data. In line with this advancement, these training paradigms have recently been adapted to the recommendation domain and are seen as a promising direction in both academia and industry. This half-day tutorial aims to provide a thorough understanding of extracting and transferring knowledge from pre-trained models learned through different training paradigms to improve recommender systems from various perspectives, such as generality, sparsity, effectiveness and trustworthiness. In this tutorial, we first introduce the basic concepts and a generic architecture of the language modeling paradigm for recommendation purposes. Then, we focus on recent advancements in adapting LLM-related training strategies and optimization objectives for different recommendation tasks. After that, we will systematically introduce ethical issues in LLM-based recommender systems and discuss possible approaches to assessing and mitigating them. We will also summarize the relevant datasets, evaluation metrics, and an empirical study on the recommendation performance of training paradigms. Finally, we will conclude the tutorial with a discussion of open challenges and future directions., Comment: Tutorial held at the 27th European Conference on Artificial Intelligence (ECAI) in Santiago de Compostela, Spain, on October 19-24, 2024
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- 2024
33. Biocatalytic enantioselective C(sp3)–H fluorination enabled by directed evolution of non-haem iron enzymes
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Zhao, Liu-Peng, Mai, Binh Khanh, Cheng, Lida, Gao, Fangqiu, Zhao, Yunlong, Guo, Rui, Wu, Hao, Zhang, Yongda, Liu, Peng, and Yang, Yang
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- 2024
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34. Dietary Structure and Nutritional Status of Chinese Beekeepers: Demographic Health Survey
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Wang, Boshi, Cheng, Zhangkai Jason, Xu, Qian, Zhu, Tiangang, Su, Lin, Xue, Mingshan, Pei, Lin, Zhu, Li, and Liu, Peng
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Public aspects of medicine ,RA1-1270 - Abstract
BackgroundBeekeeping and honey gathering are traditional forms of agricultural farming in China. However, only few studies have focused on the nutritional status and health level of this special occupational group. ObjectiveBy comparing the health status of apiculturists (beekeepers) and vegetable farmers in plain areas of Hubei Province, and analyzing the influence of dietary structure and intake on their nutritional level, this paper provides a scientific theoretical basis for the further development of health education and disease prevention for beekeepers. MethodsFrom February to April 2016, 191/236 beekeepers (80.9% of the total beekeepers) with large-scale breeding (300-500 colonies) and 182 vegetable farmers in the same area were sampled by the cluster sampling method. Their nutrient composition was analyzed using a human body composition analyzer, dietary structure information was collected using the dietary frequency query method, and cognitive function was investigated. In addition, blood samples of both groups were collected. ResultsA total of 362 valid questionnaires (beekeepers/vegetable farmers: 185/177) were collected, with an effective response rate of 97.1% (362/373). Both beekeepers and vegetable farmers were overweight, and the beekeepers’ grip strength was much stronger than that of the vegetable farmers’ regardless of gender. The dietary structure of beekeepers is very unique: 29.7% (55/185) of beekeepers indicated consuming royal jelly regularly for more than 10 years. Their main foods are grain, cereals, and fresh vegetables; 68.1% (126/185) of the beekeepers never drank milk and other dairy products, and their overall nutrient intake is unbalanced. The average intake of cellulose in this group was also significantly higher than that in the epidemiological survey in the same sex and age group. The intake of vitamin A and selenium in the beekeepers group was significantly higher than that in the vegetable-farmers group (all P
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- 2021
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35. Performance Characteristics of the NeuroEXPLORER, a Next-Generation Human Brain PET/CT Imager.
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Li, Hongdi, Badawi, Ramsey, Cherry, Simon, Fontaine, Kathryn, He, Liuchun, Henry, Shannan, Hillmer, Ansel, Hu, Lingzhi, Khattar, Nikkita, Leung, Edwin, Li, Tiantian, Li, Yusheng, Liu, Chi, Liu, Peng, Lu, Zhenrui, Majewski, Stanislaw, Matuskey, David, Morris, Evan, Mulnix, Tim, Omidvari, Negar, Samanta, Suranjana, Selfridge, Aaron, Sun, Xishan, Toyonaga, Takuya, Volpi, Tommaso, Zeng, Tianyi, Jones, Terry, Qi, Jinyi, and Carson, Richard
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DOI ,NEMA ,NeuroEXPLORER ,brain PET ,high resolution - Abstract
The collaboration of Yale, the University of California, Davis, and United Imaging Healthcare has successfully developed the NeuroEXPLORER, a dedicated human brain PET imager with high spatial resolution, high sensitivity, and a built-in 3-dimensional camera for markerless continuous motion tracking. It has high depth-of-interaction and time-of-flight resolutions, along with a 52.4-cm transverse field of view (FOV) and an extended axial FOV (49.5 cm) to enhance sensitivity. Here, we present the physical characterization, performance evaluation, and first human images of the NeuroEXPLORER. Methods: Measurements of spatial resolution, sensitivity, count rate performance, energy and timing resolution, and image quality were performed adhering to the National Electrical Manufacturers Association (NEMA) NU 2-2018 standard. The systems performance was demonstrated through imaging studies of the Hoffman 3-dimensional brain phantom and the mini-Derenzo phantom. Initial 18F-FDG images from a healthy volunteer are presented. Results: With filtered backprojection reconstruction, the radial and tangential spatial resolutions (full width at half maximum) averaged 1.64, 2.06, and 2.51 mm, with axial resolutions of 2.73, 2.89, and 2.93 mm for radial offsets of 1, 10, and 20 cm, respectively. The average time-of-flight resolution was 236 ps, and the energy resolution was 10.5%. NEMA sensitivities were 46.0 and 47.6 kcps/MBq at the center and 10-cm offset, respectively. A sensitivity of 11.8% was achieved at the FOV center. The peak noise-equivalent count rate was 1.31 Mcps at 58.0 kBq/mL, and the scatter fraction at 5.3 kBq/mL was 36.5%. The maximum count rate error at the peak noise-equivalent count rate was less than 5%. At 3 iterations, the NEMA image-quality contrast recovery coefficients varied from 74.5% (10-mm sphere) to 92.6% (37-mm sphere), and background variability ranged from 3.1% to 1.4% at a contrast of 4.0:1. An example human brain 18F-FDG image exhibited very high resolution, capturing intricate details in the cortex and subcortical structures. Conclusion: The NeuroEXPLORER offers high sensitivity and high spatial resolution. With its long axial length, it also enables high-quality spinal cord imaging and image-derived input functions from the carotid arteries. These performance enhancements will substantially broaden the range of human brain PET paradigms, protocols, and thereby clinical research applications.
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- 2024
36. A hybrid LLM workflow can help identify user privilege related variables in programs of any size
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Wang, Haizhou, Wang, Zhilong, and Liu, Peng
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Computer Science - Cryptography and Security ,Computer Science - Software Engineering - Abstract
Many programs involves operations and logic manipulating user privileges, which is essential for the security of an organization. Therefore, one common malicious goal of attackers is to obtain or escalate the privileges, causing privilege leakage. To protect the program and the organization against privilege leakage attacks, it is important to eliminate the vulnerabilities which can be exploited to achieve such attacks. Unfortunately, while memory vulnerabilities are less challenging to find, logic vulnerabilities are much more imminent, harmful and difficult to identify. Accordingly, many analysts choose to find user privilege related (UPR) variables first as start points to investigate the code where the UPR variables may be used to see if there exists any vulnerabilities, especially the logic ones. In this paper, we introduce a large language model (LLM) workflow that can assist analysts in identifying such UPR variables, which is considered to be a very time-consuming task. Specifically, our tool will audit all the variables in a program and output a UPR score, which is the degree of relationship (closeness) between the variable and user privileges, for each variable. The proposed approach avoids the drawbacks introduced by directly prompting a LLM to find UPR variables by focusing on leverage the LLM at statement level instead of supplying LLM with very long code snippets. Those variables with high UPR scores are essentially potential UPR variables, which should be manually investigated. Our experiments show that using a typical UPR score threshold (i.e., UPR score >0.8), the false positive rate (FPR) is only 13.49%, while UPR variable found is significantly more than that of the heuristic based method.
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- 2024
37. Antinetwork among China A-shares
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Liu, Peng
- Subjects
Quantitative Finance - Statistical Finance ,Economics - General Economics ,Physics - Physics and Society ,Quantitative Finance - General Finance - Abstract
The correlation-based financial networks, constructed with the correlation relationships among the time series of fluctuations of daily logarithmic prices of stocks, are intensively studied. However, these studies ignore the importance of negative correlations. This paper is the first time to consider the negative and positive correlations separately, and accordingly to construct weighted temporal antinetwork and network among stocks listed in the Shanghai and Shenzhen stock exchanges. For (anti)networks during the first 24 years of the 21st century, the node's degree and strength, the assortativity coefficient, the average local clustering coefficient, and the average shortest path length are analyzed systematically. This paper unveils some essential differences in these topological measurements between antinetwork and network. The findings of the differences between antinetwork and network have an important role in understanding the dynamics of a financial complex system. The observation of antinetwork is of great importance in optimizing investment portfolios and risk management. More importantly, this paper proposes a new direction for studying complex systems, namely the correlation-based antinetwork.
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- 2024
38. Robust Numerical Methods for Nonlinear Regression
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Liu, Peng and Meeker, William Q.
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Statistics - Methodology ,Statistics - Computation - Abstract
Many scientific and engineering applications require fitting regression models that are nonlinear in the parameters. Advances in computer hardware and software in recent decades have made it easier to fit such models. Relative to fitting regression models that are linear in the parameters, however, fitting nonlinear regression models is more complicated. In particular, software like the $\texttt{nls}$ R function requires care in how the model is parameterized and how initial values are chosen for the maximum likelihood iterations. Often special diagnostics are needed to detect and suggest approaches for dealing with identifiability problems that can arise with such model fitting. When using Bayesian inference, there is the added complication of having to specify (often noninformative or weakly informative) prior distributions. Generally, the details for these tasks must be determined for each new nonlinear regression model. This paper provides a step-by-step procedure for specifying these details for any appropriate nonlinear regression model. Following the procedure will result in a numerically robust algorithm for fitting the nonlinear regression model. We illustrate the methods with three different nonlinear models that are used in the analysis of experimental fatigue data and we include two detailed numerical examples.
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- 2024
39. On Equivalence of Likelihood-Based Confidence Bands for Fatigue-Life and Fatigue-Strength Distributions
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Liu, Peng, Hong, Yili, Escobar, Luis A., and Meeker, William Q.
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Statistics - Methodology ,Mathematics - Statistics Theory - Abstract
Fatigue data arise in many research and applied areas and there have been statistical methods developed to model and analyze such data. The distributions of fatigue life and fatigue strength are often of interest to engineers designing products that might fail due to fatigue from cyclic-stress loading. Based on a specified statistical model and the maximum likelihood method, the cumulative distribution function (cdf) and quantile function (qf) can be estimated for the fatigue-life and fatigue-strength distributions. Likelihood-based confidence bands then can be obtained for the cdf and qf. This paper provides equivalence results for confidence bands for fatigue-life and fatigue-strength models. These results are useful for data analysis and computing implementation. We show (a) the equivalence of the confidence bands for the fatigue-life cdf and the fatigue-life qf, (b) the equivalence of confidence bands for the fatigue-strength cdf and the fatigue-strength qf, and (c) the equivalence of confidence bands for the fatigue-life qf and the fatigue-strength qf. Then we illustrate the usefulness of those equivalence results with two examples using experimental fatigue data.
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- 2024
40. Real-time Transformer-based Open-Vocabulary Detection with Efficient Fusion Head
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Zhao, Tiancheng, Liu, Peng, He, Xuan, Zhang, Lu, and Lee, Kyusong
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Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Computation and Language - Abstract
End-to-end transformer-based detectors (DETRs) have shown exceptional performance in both closed-set and open-vocabulary object detection (OVD) tasks through the integration of language modalities. However, their demanding computational requirements have hindered their practical application in real-time object detection (OD) scenarios. In this paper, we scrutinize the limitations of two leading models in the OVDEval benchmark, OmDet and Grounding-DINO, and introduce OmDet-Turbo. This novel transformer-based real-time OVD model features an innovative Efficient Fusion Head (EFH) module designed to alleviate the bottlenecks observed in OmDet and Grounding-DINO. Notably, OmDet-Turbo-Base achieves a 100.2 frames per second (FPS) with TensorRT and language cache techniques applied. Notably, in zero-shot scenarios on COCO and LVIS datasets, OmDet-Turbo achieves performance levels nearly on par with current state-of-the-art supervised models. Furthermore, it establishes new state-of-the-art benchmarks on ODinW and OVDEval, boasting an AP of 30.1 and an NMS-AP of 26.86, respectively. The practicality of OmDet-Turbo in industrial applications is underscored by its exceptional performance on benchmark datasets and superior inference speed, positioning it as a compelling choice for real-time object detection tasks. Code: \url{https://github.com/om-ai-lab/OmDet}, Comment: Preprint
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- 2024
41. Yi: Open Foundation Models by 01.AI
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AI, 01., Young, Alex, Chen, Bei, Li, Chao, Huang, Chengen, Zhang, Ge, Zhang, Guanwei, Li, Heng, Zhu, Jiangcheng, Chen, Jianqun, Chang, Jing, Yu, Kaidong, Liu, Peng, Liu, Qiang, Yue, Shawn, Yang, Senbin, Yang, Shiming, Yu, Tao, Xie, Wen, Huang, Wenhao, Hu, Xiaohui, Ren, Xiaoyi, Niu, Xinyao, Nie, Pengcheng, Xu, Yuchi, Liu, Yudong, Wang, Yue, Cai, Yuxuan, Gu, Zhenyu, Liu, Zhiyuan, and Dai, Zonghong
- Subjects
Computer Science - Computation and Language ,Computer Science - Artificial Intelligence - Abstract
We introduce the Yi model family, a series of language and multimodal models that demonstrate strong multi-dimensional capabilities. The Yi model family is based on 6B and 34B pretrained language models, then we extend them to chat models, 200K long context models, depth-upscaled models, and vision-language models. Our base models achieve strong performance on a wide range of benchmarks like MMLU, and our finetuned chat models deliver strong human preference rate on major evaluation platforms like AlpacaEval and Chatbot Arena. Building upon our scalable super-computing infrastructure and the classical transformer architecture, we attribute the performance of Yi models primarily to its data quality resulting from our data-engineering efforts. For pretraining, we construct 3.1 trillion tokens of English and Chinese corpora using a cascaded data deduplication and quality filtering pipeline. For finetuning, we polish a small scale (less than 10K) instruction dataset over multiple iterations such that every single instance has been verified directly by our machine learning engineers. For vision-language, we combine the chat language model with a vision transformer encoder and train the model to align visual representations to the semantic space of the language model. We further extend the context length to 200K through lightweight continual pretraining and demonstrate strong needle-in-a-haystack retrieval performance. We show that extending the depth of the pretrained checkpoint through continual pretraining further improves performance. We believe that given our current results, continuing to scale up model parameters using thoroughly optimized data will lead to even stronger frontier models.
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- 2024
42. RFWave: Multi-band Rectified Flow for Audio Waveform Reconstruction
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Liu, Peng, Dai, Dongyang, and Wu, Zhiyong
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Computer Science - Sound ,Computer Science - Artificial Intelligence ,Electrical Engineering and Systems Science - Audio and Speech Processing - Abstract
Recent advancements in generative modeling have significantly enhanced the reconstruction of audio waveforms from various representations. While diffusion models are adept at this task, they are hindered by latency issues due to their operation at the individual sample point level and the need for numerous sampling steps. In this study, we introduce RFWave, a cutting-edge multi-band Rectified Flow approach designed to reconstruct high-fidelity audio waveforms from Mel-spectrograms or discrete tokens. RFWave uniquely generates complex spectrograms and operates at the frame level, processing all subbands simultaneously to boost efficiency. Leveraging Rectified Flow, which targets a flat transport trajectory, RFWave achieves reconstruction with just 10 sampling steps. Our empirical evaluations show that RFWave not only provides outstanding reconstruction quality but also offers vastly superior computational efficiency, enabling audio generation at speeds up to 97 times faster than real-time on a GPU. An online demonstration is available at: https://rfwave-demo.github.io/rfwave/.
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- 2024
43. DeepCRE: Transforming Drug R&D via AI-Driven Cross-drug Response Evaluation
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Wu, Yushuai, Zhang, Ting, Zhou, Hao, Wu, Hainan, Sunchu, Hanwen, Hu, Lei, Chen, Xiaofang, Zhao, Suyuan, Liu, Gaochao, Sun, Chao, Zhang, Jiahuan, Luo, Yizhen, Liu, Peng, and Nie, Zaiqing
- Subjects
Computer Science - Artificial Intelligence ,Computer Science - Machine Learning ,Quantitative Biology - Quantitative Methods - Abstract
The fields of therapeutic application and drug research and development (R&D) both face substantial challenges, i.e., the therapeutic domain calls for more treatment alternatives, while numerous promising pre-clinical drugs have failed in clinical trials. One of the reasons is the inadequacy of Cross-drug Response Evaluation (CRE) during the late stages of drug R&D. Although in-silico CRE models bring a promising solution, existing methodologies are restricted to early stages of drug R&D, such as target and cell-line levels, offering limited improvement to clinical success rates. Herein, we introduce DeepCRE, a pioneering AI model designed to predict CRE effectively in the late stages of drug R&D. DeepCRE outperforms the existing best models by achieving an average performance improvement of 17.7% in patient-level CRE, and a 5-fold increase in indication-level CRE, facilitating more accurate personalized treatment predictions and better pharmaceutical value assessment for indications, respectively. Furthermore, DeepCRE has identified a set of six drug candidates that show significantly greater effectiveness than a comparator set of two approved drugs in 5/8 colorectal cancer organoids. This demonstrates the capability of DeepCRE to systematically uncover a spectrum of drug candidates with enhanced therapeutic effects, highlighting its potential to transform drug R&D.
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- 2024
44. Dispersive-wave-agile optical frequency division
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Ji, Qing-Xin, Zhang, Wei, Liu, Peng, Jin, Warren, Guo, Joel, Peters, Jonathan, Wu, Lue, Feshali, Avi, Paniccia, Mario, Ilchenko, Vladimir, Bowers, John, Matsko, Andrey, and Vahala, Kerry
- Subjects
Physics - Optics - Abstract
The remarkable frequency stability of resonant systems in the optical domain (optical cavities and atomic transitions) can be harnessed at frequency scales accessible by electronics using optical frequency division. This capability is revolutionizing technologies spanning time keeping to high-performance electrical signal sources. A version of the technique called 2-point optical frequency division (2P-OFD) is proving advantageous for application to high-performance signal sources. In 2P-OFD, an optical cavity anchors two spectral endpoints defined by lines of a frequency comb. The comb need not be self-referenced, which greatly simplifies the system architecture and reduces power requirements. Here, a 2P-OFD microwave signal source is demonstrated with record-low phase noise using a microcomb. Key to this advance is a spectral endpoint defined by a frequency agile single-mode dispersive wave that is emitted by the microcomb soliton. Moreover, the system frequency reference is a compact all-solid-state optical cavity with a record Q-factor. The results advance integrable microcomb-based signal sources into the performance realm of much larger microwave sources.
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- 2024
45. Exact non-Hermitian mobility edges and robust flat bands in two-dimensional Lieb lattices with imaginary quasiperiodic potentials
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Jiang, Xiang-Ping, Zeng, Weilei, Hu, Yayun, and Liu, Peng
- Subjects
Condensed Matter - Disordered Systems and Neural Networks - Abstract
The mobility edge (ME) is a critical energy delineates the boundary between extended and localized states within the energy spectrum, and it plays a crucial role in understanding the metal-insulator transition in disordered or quasiperiodic systems. While there have been extensive studies on MEs in one-dimensional non-Hermitian (NH) quasiperiodic lattices recently, the investigation of exact NH MEs in two-dimensional (2D) cases remains rare. In the present study, we introduce a 2D dissipative Lieb lattice (DLL) model with imaginary quasiperiodic potentials applied solely to the vertices of the Lieb lattice. By mapping this DLL model to the 2D NH Aubry-Andr{\'e}-Harper (AAH) model, we analytically derive the exact ME and find it associated with the absolute eigenenergies. We find that the eigenvalues of extended states are purely imaginary when the quasiperiodic potential is strong enough. Additionally, we demonstrate that the introduction of imaginary quasiperiodic potentials does not disrupt the flat bands inherent in the system. Finally, we propose a theoretical framework for realizing our model using the Lindblad master equation. Our results pave the way for further investigation of exact NH MEs and flat bands in 2D dissipative quasiperiodic systems.
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- 2024
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46. Auxiliary Reward Generation with Transition Distance Representation Learning
- Author
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Li, Siyuan, Han, Shijie, Zhao, Yingnan, Liang, By, and Liu, Peng
- Subjects
Computer Science - Machine Learning ,Computer Science - Artificial Intelligence - Abstract
Reinforcement learning (RL) has shown its strength in challenging sequential decision-making problems. The reward function in RL is crucial to the learning performance, as it serves as a measure of the task completion degree. In real-world problems, the rewards are predominantly human-designed, which requires laborious tuning, and is easily affected by human cognitive biases. To achieve automatic auxiliary reward generation, we propose a novel representation learning approach that can measure the ``transition distance'' between states. Building upon these representations, we introduce an auxiliary reward generation technique for both single-task and skill-chaining scenarios without the need for human knowledge. The proposed approach is evaluated in a wide range of manipulation tasks. The experiment results demonstrate the effectiveness of measuring the transition distance between states and the induced improvement by auxiliary rewards, which not only promotes better learning efficiency but also increases convergent stability.
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- 2024
47. Safeguarding the Truth of High-Value Price Oracle Task: A Dynamically Adjusted Truth Discovery Method
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Xian, Youquan, Liu, Peng, Li, Dongcheng, and Zeng, Xueying
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Computer Science - Computer Science and Game Theory ,Computer Science - Computational Engineering, Finance, and Science ,Computer Science - Distributed, Parallel, and Cluster Computing - Abstract
In recent years, the Decentralized Finance (DeFi) market has witnessed numerous attacks on the price oracle, leading to substantial economic losses. Despite the advent of truth discovery methods opening up new avenues for oracle development, it falls short in addressing high-value attacks on price oracle tasks. Consequently, this paper introduces a dynamically adjusted truth discovery method safeguarding the truth of high-value price oracle tasks. In the truth aggregation stage, we enhance future considerations to improve the precision of aggregated truth. During the credibility update phase, credibility is dynamically assessed based on the task's value and the Cumulative Potential Economic Contribution (CPEC) of information sources. Experimental results demonstrate a significant reduction in data deviation by 65.8\% and potential economic loss by 66.5\%, compared to the baseline scheme, in the presence of high-value attacks., Comment: 10 pages, 7 figures
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- 2024
48. An objective comparison of methods for augmented reality in laparoscopic liver resection by preoperative-to-intraoperative image fusion
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Ali, Sharib, Espinel, Yamid, Jin, Yueming, Liu, Peng, Güttner, Bianca, Zhang, Xukun, Zhang, Lihua, Dowrick, Tom, Clarkson, Matthew J., Xiao, Shiting, Wu, Yifan, Yang, Yijun, Zhu, Lei, Sun, Dai, Li, Lan, Pfeiffer, Micha, Farid, Shahid, Maier-Hein, Lena, Buc, Emmanuel, and Bartoli, Adrien
- Subjects
Computer Science - Computer Vision and Pattern Recognition ,Computer Science - Artificial Intelligence ,Computer Science - Graphics ,Computer Science - Machine Learning - Abstract
Augmented reality for laparoscopic liver resection is a visualisation mode that allows a surgeon to localise tumours and vessels embedded within the liver by projecting them on top of a laparoscopic image. Preoperative 3D models extracted from CT or MRI data are registered to the intraoperative laparoscopic images during this process. In terms of 3D-2D fusion, most of the algorithms make use of anatomical landmarks to guide registration. These landmarks include the liver's inferior ridge, the falciform ligament, and the occluding contours. They are usually marked by hand in both the laparoscopic image and the 3D model, which is time-consuming and may contain errors if done by a non-experienced user. Therefore, there is a need to automate this process so that augmented reality can be used effectively in the operating room. We present the Preoperative-to-Intraoperative Laparoscopic Fusion Challenge (P2ILF), held during the Medical Imaging and Computer Assisted Interventions (MICCAI 2022) conference, which investigates the possibilities of detecting these landmarks automatically and using them in registration. The challenge was divided into two tasks: 1) A 2D and 3D landmark detection task and 2) a 3D-2D registration task. The teams were provided with training data consisting of 167 laparoscopic images and 9 preoperative 3D models from 9 patients, with the corresponding 2D and 3D landmark annotations. A total of 6 teams from 4 countries participated, whose proposed methods were evaluated on 16 images and two preoperative 3D models from two patients. All the teams proposed deep learning-based methods for the 2D and 3D landmark segmentation tasks and differentiable rendering-based methods for the registration task. Based on the experimental outcomes, we propose three key hypotheses that determine current limitations and future directions for research in this domain., Comment: 24 pages
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- 2024
49. Joint Transmitter Design for Robust Secure Radar-Communication Coexistence Systems
- Author
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Liu, Peng, Fei, Zesong, Wang, Xinyi, Zheng, Zhong, Li, Xiangnan, and Xu, Jie
- Subjects
Computer Science - Information Theory ,Electrical Engineering and Systems Science - Signal Processing - Abstract
This paper investigates the spectrum sharing between a multiple-input single-output (MISO) secure communication system and a multiple-input multiple-output (MIMO) radar system in the presence of one suspicious eavesdropper. We jointly design the radar waveform and communication beamforming vector at the two systems, such that the interference between the base station (BS) and radar is reduced, and the detrimental radar interference to the communication system is enhanced to jam the eavesdropper, thereby increasing secure information transmission performance. In particular, by considering the imperfect channel state information (CSI) for the user and eavesdropper, we maximize the worst-case secrecy rate at the user, while ensuring the detection performance of radar system. To tackle this challenging problem, we propose a two-layer robust cooperative algorithm based on the S-lemma and semidefinite relaxation techniques. Simulation results demonstrate that the proposed algorithm achieves significant secrecy rate gains over the non-robust scheme. Furthermore, we illustrate the trade-off between secrecy rate and detection probability.
- Published
- 2024
50. Diffusion-based Pose Refinement and Muti-hypothesis Generation for 3D Human Pose Estimaiton
- Author
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Kang, Hongbo, Wang, Yong, Liu, Mengyuan, Wu, Doudou, Liu, Peng, Yuan, Xinlin, and Yang, Wenming
- Subjects
Computer Science - Computer Vision and Pattern Recognition - Abstract
Previous probabilistic models for 3D Human Pose Estimation (3DHPE) aimed to enhance pose accuracy by generating multiple hypotheses. However, most of the hypotheses generated deviate substantially from the true pose. Compared to deterministic models, the excessive uncertainty in probabilistic models leads to weaker performance in single-hypothesis prediction. To address these two challenges, we propose a diffusion-based refinement framework called DRPose, which refines the output of deterministic models by reverse diffusion and achieves more suitable multi-hypothesis prediction for the current pose benchmark by multi-step refinement with multiple noises. To this end, we propose a Scalable Graph Convolution Transformer (SGCT) and a Pose Refinement Module (PRM) for denoising and refining. Extensive experiments on Human3.6M and MPI-INF-3DHP datasets demonstrate that our method achieves state-of-the-art performance on both single and multi-hypothesis 3DHPE. Code is available at https://github.com/KHB1698/DRPose.
- Published
- 2024
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