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Automatic Sensor-free Affect Detection: A Systematic Literature Review
Emotions and other affective states play a pivotal role in cognition and, consequently, the learning process. It is well-established that computer-based learning environments (CBLEs) that can detect and adapt to students' affective states can enhance learning outcomes. However, practical constraints often pose challenges to the deployment of sensor-based affect detection in CBLEs, particularly for large-scale or long-term applications. As a result, sensor-free affect detection, which exclusively relies on logs of students' interactions with CBLEs, emerges as a compelling alternative. This paper provides a comprehensive literature review on sensor-free affect detection. It delves into the most frequently identified affective states, the methodologies and techniques employed for sensor development, the defining attributes of CBLEs and data samples, as well as key research trends. Despite the field's evident maturity, demonstrated by the consistent performance of the models and the application of advanced machine learning techniques, there is ample scope for future research. Potential areas for further exploration include enhancing the performance of sensor-free detection models, amassing more samples of underrepresented emotions, and identifying additional emotions. There is also a need to refine model development practices and methods. This could involve comparing the accuracy of various data collection techniques, determining the optimal granularity of duration, establishing a shared database of action logs and emotion labels, and making the source code of these models publicly accessible. Future research should also prioritize the integration of models into CBLEs for real-time detection, the provision of meaningful interventions based on detected emotions, and a deeper understanding of the impact of emotions on learning.
[ "Felipe de Morais", "Diógines Goldoni", "Tiago Kautzmann", "Rodrigo da Silva", "Patricia A. Jaques" ]
2023-10-11 13:24:27
http://arxiv.org/abs/2310.13711v1
http://arxiv.org/pdf/2310.13711v1
2310.13711v1
Deep Learning Predicts Biomarker Status and Discovers Related Histomorphology Characteristics for Low-Grade Glioma
Biomarker detection is an indispensable part in the diagnosis and treatment of low-grade glioma (LGG). However, current LGG biomarker detection methods rely on expensive and complex molecular genetic testing, for which professionals are required to analyze the results, and intra-rater variability is often reported. To overcome these challenges, we propose an interpretable deep learning pipeline, a Multi-Biomarker Histomorphology Discoverer (Multi-Beholder) model based on the multiple instance learning (MIL) framework, to predict the status of five biomarkers in LGG using only hematoxylin and eosin-stained whole slide images and slide-level biomarker status labels. Specifically, by incorporating the one-class classification into the MIL framework, accurate instance pseudo-labeling is realized for instance-level supervision, which greatly complements the slide-level labels and improves the biomarker prediction performance. Multi-Beholder demonstrates superior prediction performance and generalizability for five LGG biomarkers (AUROC=0.6469-0.9735) in two cohorts (n=607) with diverse races and scanning protocols. Moreover, the excellent interpretability of Multi-Beholder allows for discovering the quantitative and qualitative correlations between biomarker status and histomorphology characteristics. Our pipeline not only provides a novel approach for biomarker prediction, enhancing the applicability of molecular treatments for LGG patients but also facilitates the discovery of new mechanisms in molecular functionality and LGG progression.
[ "Zijie Fang", "Yihan Liu", "Yifeng Wang", "Xiangyang Zhang", "Yang Chen", "Changjing Cai", "Yiyang Lin", "Ying Han", "Zhi Wang", "Shan Zeng", "Hong Shen", "Jun Tan", "Yongbing Zhang" ]
2023-10-11 13:05:33
http://arxiv.org/abs/2310.07464v1
http://arxiv.org/pdf/2310.07464v1
2310.07464v1
Uncovering ECG Changes during Healthy Aging using Explainable AI
Cardiovascular diseases remain the leading global cause of mortality. This necessitates a profound understanding of heart aging processes to diagnose constraints in cardiovascular fitness. Traditionally, most of such insights have been drawn from the analysis of electrocardiogram (ECG) feature changes of individuals as they age. However, these features, while informative, may potentially obscure underlying data relationships. In this paper, we employ a deep-learning model and a tree-based model to analyze ECG data from a robust dataset of healthy individuals across varying ages in both raw signals and ECG feature format. Explainable AI techniques are then used to identify ECG features or raw signal characteristics are most discriminative for distinguishing between age groups. Our analysis with tree-based classifiers reveal age-related declines in inferred breathing rates and identifies notably high SDANN values as indicative of elderly individuals, distinguishing them from younger adults. Furthermore, the deep-learning model underscores the pivotal role of the P-wave in age predictions across all age groups, suggesting potential changes in the distribution of different P-wave types with age. These findings shed new light on age-related ECG changes, offering insights that transcend traditional feature-based approaches.
[ "Gabriel Ott", "Yannik Schaubelt", "Juan Miguel Lopez Alcaraz", "Wilhelm Haverkamp", "Nils Strodthoff" ]
2023-10-11 13:05:28
http://arxiv.org/abs/2310.07463v1
http://arxiv.org/pdf/2310.07463v1
2310.07463v1
Efficient machine-learning surrogates for large-scale geological carbon and energy storage
Geological carbon and energy storage are pivotal for achieving net-zero carbon emissions and addressing climate change. However, they face uncertainties due to geological factors and operational limitations, resulting in possibilities of induced seismic events or groundwater contamination. To overcome these challenges, we propose a specialized machine-learning (ML) model to manage extensive reservoir models efficiently. While ML approaches hold promise for geological carbon storage, the substantial computational resources required for large-scale analysis are the obstacle. We've developed a method to reduce the training cost for deep neural operator models, using domain decomposition and a topology embedder to link spatio-temporal points. This approach allows accurate predictions within the model's domain, even for untrained data, enhancing ML efficiency for large-scale geological storage applications.
[ "Teeratorn Kadeethum", "Stephen J. Verzi", "Hongkyu Yoon" ]
2023-10-11 13:05:03
http://arxiv.org/abs/2310.07461v1
http://arxiv.org/pdf/2310.07461v1
2310.07461v1
ProbTS: A Unified Toolkit to Probe Deep Time-series Forecasting
Time-series forecasting serves as a linchpin in a myriad of applications, spanning various domains. With the growth of deep learning, this arena has bifurcated into two salient branches: one focuses on crafting specific neural architectures tailored for time series, and the other harnesses advanced deep generative models for probabilistic forecasting. While both branches have made significant progress, their differences across data scenarios, methodological focuses, and decoding schemes pose profound, yet unexplored, research questions. To bridge this knowledge chasm, we introduce ProbTS, a pioneering toolkit developed to synergize and compare these two distinct branches. Endowed with a unified data module, a modularized model module, and a comprehensive evaluator module, ProbTS allows us to revisit and benchmark leading methods from both branches. The scrutiny with ProbTS highlights their distinct characteristics, relative strengths and weaknesses, and areas that need further exploration. Our analyses point to new avenues for research, aiming for more effective time-series forecasting.
[ "Jiawen Zhang", "Xumeng Wen", "Shun Zheng", "Jia Li", "Jiang Bian" ]
2023-10-11 12:48:45
http://arxiv.org/abs/2310.07446v1
http://arxiv.org/pdf/2310.07446v1
2310.07446v1
A Branched Deep Convolutional Network for Forecasting the Occurrence of Hazes in Paris using Meteorological Maps with Different Characteristic Spatial Scales
A deep learning platform has been developed to forecast the occurrence of the low visibility events or hazes. It is trained by using multi-decadal daily regional maps of various meteorological and hydrological variables as input features and surface visibility observations as the targets. To better preserve the characteristic spatial information of different input features for training, two branched architectures have recently been developed for the case of Paris hazes. These new architectures have improved the performance of the network, producing reasonable scores in both validation and a blind forecasting evaluation using the data of 2021 and 2022 that have not been used in the training and validation.
[ "Chien Wang" ]
2023-10-11 12:40:07
http://arxiv.org/abs/2310.07437v2
http://arxiv.org/pdf/2310.07437v2
2310.07437v2
Generalized Mixture Model for Extreme Events Forecasting in Time Series Data
Time Series Forecasting (TSF) is a widely researched topic with broad applications in weather forecasting, traffic control, and stock price prediction. Extreme values in time series often significantly impact human and natural systems, but predicting them is challenging due to their rare occurrence. Statistical methods based on Extreme Value Theory (EVT) provide a systematic approach to modeling the distribution of extremes, particularly the Generalized Pareto (GP) distribution for modeling the distribution of exceedances beyond a threshold. To overcome the subpar performance of deep learning in dealing with heavy-tailed data, we propose a novel framework to enhance the focus on extreme events. Specifically, we propose a Deep Extreme Mixture Model with Autoencoder (DEMMA) for time series prediction. The model comprises two main modules: 1) a generalized mixture distribution based on the Hurdle model and a reparameterized GP distribution form independent of the extreme threshold, 2) an Autoencoder-based LSTM feature extractor and a quantile prediction module with a temporal attention mechanism. We demonstrate the effectiveness of our approach on multiple real-world rainfall datasets.
[ "Jincheng Wang", "Yue Gao" ]
2023-10-11 12:36:42
http://arxiv.org/abs/2310.07435v1
http://arxiv.org/pdf/2310.07435v1
2310.07435v1
HealthWalk: Promoting Health and Mobility through Sensor-Based Rollator Walker Assistance
Rollator walkers allow people with physical limitations to increase their mobility and give them the confidence and independence to participate in society for longer. However, rollator walker users often have poor posture, leading to further health problems and, in the worst case, falls. Integrating sensors into rollator walker designs can help to address this problem and results in a platform that allows several other interesting use cases. This paper briefly overviews existing systems and the current research directions and challenges in this field. We also present our early HealthWalk rollator walker prototype for data collection with older people, rheumatism, multiple sclerosis and Parkinson patients, and individuals with visual impairments.
[ "Ivanna Kramer", "Kevin Weirauch", "Sabine Bauer", "Mark Oliver Mints", "Peer Neubert" ]
2023-10-11 12:36:38
http://arxiv.org/abs/2310.07434v1
http://arxiv.org/pdf/2310.07434v1
2310.07434v1
Imitation Learning from Observation with Automatic Discount Scheduling
Humans often acquire new skills through observation and imitation. For robotic agents, learning from the plethora of unlabeled video demonstration data available on the Internet necessitates imitating the expert without access to its action, presenting a challenge known as Imitation Learning from Observations (ILfO). A common approach to tackle ILfO problems is to convert them into inverse reinforcement learning problems, utilizing a proxy reward computed from the agent's and the expert's observations. Nonetheless, we identify that tasks characterized by a progress dependency property pose significant challenges for such approaches; in these tasks, the agent needs to initially learn the expert's preceding behaviors before mastering the subsequent ones. Our investigation reveals that the main cause is that the reward signals assigned to later steps hinder the learning of initial behaviors. To address this challenge, we present a novel ILfO framework that enables the agent to master earlier behaviors before advancing to later ones. We introduce an Automatic Discount Scheduling (ADS) mechanism that adaptively alters the discount factor in reinforcement learning during the training phase, prioritizing earlier rewards initially and gradually engaging later rewards only when the earlier behaviors have been mastered. Our experiments, conducted on nine Meta-World tasks, demonstrate that our method significantly outperforms state-of-the-art methods across all tasks, including those that are unsolvable by them.
[ "Yuyang Liu", "Weijun Dong", "Yingdong Hu", "Chuan Wen", "Zhao-Heng Yin", "Chongjie Zhang", "Yang Gao" ]
2023-10-11 12:34:39
http://arxiv.org/abs/2310.07433v2
http://arxiv.org/pdf/2310.07433v2
2310.07433v2
Non-backtracking Graph Neural Networks
The celebrated message-passing updates for graph neural networks allow the representation of large-scale graphs with local and computationally tractable updates. However, the local updates suffer from backtracking, i.e., a message flows through the same edge twice and revisits the previously visited node. Since the number of message flows increases exponentially with the number of updates, the redundancy in local updates prevents the graph neural network from accurately recognizing a particular message flow for downstream tasks. In this work, we propose to resolve such a redundancy via the non-backtracking graph neural network (NBA-GNN) that updates a message without incorporating the message from the previously visited node. We further investigate how NBA-GNN alleviates the over-squashing of GNNs, and establish a connection between NBA-GNN and the impressive performance of non-backtracking updates for stochastic block model recovery. We empirically verify the effectiveness of our NBA-GNN on long-range graph benchmark and transductive node classification problems.
[ "Seonghyun Park", "Narae Ryu", "Gahee Kim", "Dongyeop Woo", "Se-Young Yun", "Sungsoo Ahn" ]
2023-10-11 12:32:13
http://arxiv.org/abs/2310.07430v1
http://arxiv.org/pdf/2310.07430v1
2310.07430v1
Quantum-Enhanced Forecasting: Leveraging Quantum Gramian Angular Field and CNNs for Stock Return Predictions
We propose a time series forecasting method named Quantum Gramian Angular Field (QGAF). This approach merges the advantages of quantum computing technology with deep learning, aiming to enhance the precision of time series classification and forecasting. We successfully transformed stock return time series data into two-dimensional images suitable for Convolutional Neural Network (CNN) training by designing specific quantum circuits. Distinct from the classical Gramian Angular Field (GAF) approach, QGAF's uniqueness lies in eliminating the need for data normalization and inverse cosine calculations, simplifying the transformation process from time series data to two-dimensional images. To validate the effectiveness of this method, we conducted experiments on datasets from three major stock markets: the China A-share market, the Hong Kong stock market, and the US stock market. Experimental results revealed that compared to the classical GAF method, the QGAF approach significantly improved time series prediction accuracy, reducing prediction errors by an average of 25% for Mean Absolute Error (MAE) and 48% for Mean Squared Error (MSE). This research confirms the potential and promising prospects of integrating quantum computing with deep learning techniques in financial time series forecasting.
[ "Zhengmeng Xu", "Hai Lin" ]
2023-10-11 12:28:52
http://arxiv.org/abs/2310.07427v2
http://arxiv.org/pdf/2310.07427v2
2310.07427v2
Revisiting Plasticity in Visual Reinforcement Learning: Data, Modules and Training Stages
Plasticity, the ability of a neural network to evolve with new data, is crucial for high-performance and sample-efficient visual reinforcement learning (VRL). Although methods like resetting and regularization can potentially mitigate plasticity loss, the influences of various components within the VRL framework on the agent's plasticity are still poorly understood. In this work, we conduct a systematic empirical exploration focusing on three primary underexplored facets and derive the following insightful conclusions: (1) data augmentation is essential in maintaining plasticity; (2) the critic's plasticity loss serves as the principal bottleneck impeding efficient training; and (3) without timely intervention to recover critic's plasticity in the early stages, its loss becomes catastrophic. These insights suggest a novel strategy to address the high replay ratio (RR) dilemma, where exacerbated plasticity loss hinders the potential improvements of sample efficiency brought by increased reuse frequency. Rather than setting a static RR for the entire training process, we propose Adaptive RR, which dynamically adjusts the RR based on the critic's plasticity level. Extensive evaluations indicate that Adaptive RR not only avoids catastrophic plasticity loss in the early stages but also benefits from more frequent reuse in later phases, resulting in superior sample efficiency.
[ "Guozheng Ma", "Lu Li", "Sen Zhang", "Zixuan Liu", "Zhen Wang", "Yixin Chen", "Li Shen", "Xueqian Wang", "Dacheng Tao" ]
2023-10-11 12:05:34
http://arxiv.org/abs/2310.07418v1
http://arxiv.org/pdf/2310.07418v1
2310.07418v1
What can knowledge graph alignment gain with Neuro-Symbolic learning approaches?
Knowledge Graphs (KG) are the backbone of many data-intensive applications since they can represent data coupled with its meaning and context. Aligning KGs across different domains and providers is necessary to afford a fuller and integrated representation. A severe limitation of current KG alignment (KGA) algorithms is that they fail to articulate logical thinking and reasoning with lexical, structural, and semantic data learning. Deep learning models are increasingly popular for KGA inspired by their good performance in other tasks, but they suffer from limitations in explainability, reasoning, and data efficiency. Hybrid neurosymbolic learning models hold the promise of integrating logical and data perspectives to produce high-quality alignments that are explainable and support validation through human-centric approaches. This paper examines the current state of the art in KGA and explores the potential for neurosymbolic integration, highlighting promising research directions for combining these fields.
[ "Pedro Giesteira Cotovio", "Ernesto Jimenez-Ruiz", "Catia Pesquita" ]
2023-10-11 12:03:19
http://arxiv.org/abs/2310.07417v1
http://arxiv.org/pdf/2310.07417v1
2310.07417v1
A Novel Voronoi-based Convolutional Neural Network Framework for Pushing Person Detection in Crowd Videos
Analyzing the microscopic dynamics of pushing behavior within crowds can offer valuable insights into crowd patterns and interactions. By identifying instances of pushing in crowd videos, a deeper understanding of when, where, and why such behavior occurs can be achieved. This knowledge is crucial to creating more effective crowd management strategies, optimizing crowd flow, and enhancing overall crowd experiences. However, manually identifying pushing behavior at the microscopic level is challenging, and the existing automatic approaches cannot detect such microscopic behavior. Thus, this article introduces a novel automatic framework for identifying pushing in videos of crowds on a microscopic level. The framework comprises two main components: i) Feature extraction and ii) Video labeling. In the feature extraction component, a new Voronoi-based method is developed for determining the local regions associated with each person in the input video. Subsequently, these regions are fed into EfficientNetV1B0 Convolutional Neural Network to extract the deep features of each person over time. In the second component, a combination of a fully connected layer with a Sigmoid activation function is employed to analyze these deep features and annotate the individuals involved in pushing within the video. The framework is trained and evaluated on a new dataset created using six real-world experiments, including their corresponding ground truths. The experimental findings indicate that the suggested framework outperforms seven baseline methods that are employed for comparative analysis purposes.
[ "Ahmed Alia", "Mohammed Maree", "Mohcine Chraibi", "Armin Seyfried" ]
2023-10-11 12:01:52
http://arxiv.org/abs/2310.07416v1
http://arxiv.org/pdf/2310.07416v1
2310.07416v1
NuTime: Numerically Multi-Scaled Embedding for Large-Scale Time Series Pretraining
Recent research on time-series self-supervised models shows great promise in learning semantic representations. However, it has been limited to small-scale datasets, e.g., thousands of temporal sequences. In this work, we make key technical contributions that are tailored to the numerical properties of time-series data and allow the model to scale to large datasets, e.g., millions of temporal sequences. We adopt the Transformer architecture by first partitioning the input into non-overlapping windows. Each window is then characterized by its normalized shape and two scalar values denoting the mean and standard deviation within each window. To embed scalar values that may possess arbitrary numerical scales to high-dimensional vectors, we propose a numerically multi-scaled embedding module enumerating all possible scales for the scalar values. The model undergoes pretraining using the proposed numerically multi-scaled embedding with a simple contrastive objective on a large-scale dataset containing over a million sequences. We study its transfer performance on a number of univariate and multivariate classification benchmarks. Our method exhibits remarkable improvement against previous representation learning approaches and establishes the new state of the art, even compared with domain-specific non-learning-based methods.
[ "Chenguo Lin", "Xumeng Wen", "Wei Cao", "Congrui Huang", "Jiang Bian", "Stephen Lin", "Zhirong Wu" ]
2023-10-11 11:38:18
http://arxiv.org/abs/2310.07402v2
http://arxiv.org/pdf/2310.07402v2
2310.07402v2
Deep Kernel and Image Quality Estimators for Optimizing Robotic Ultrasound Controller using Bayesian Optimization
Ultrasound is a commonly used medical imaging modality that requires expert sonographers to manually maneuver the ultrasound probe based on the acquired image. Autonomous Robotic Ultrasound (A-RUS) is an appealing alternative to this manual procedure in order to reduce sonographers' workload. The key challenge to A-RUS is optimizing the ultrasound image quality for the region of interest across different patients. This requires knowledge of anatomy, recognition of error sources and precise probe position, orientation and pressure. Sample efficiency is important while optimizing these parameters associated with the robotized probe controller. Bayesian Optimization (BO), a sample-efficient optimization framework, has recently been applied to optimize the 2D motion of the probe. Nevertheless, further improvements are needed to improve the sample efficiency for high-dimensional control of the probe. We aim to overcome this problem by using a neural network to learn a low-dimensional kernel in BO, termed as Deep Kernel (DK). The neural network of DK is trained using probe and image data acquired during the procedure. The two image quality estimators are proposed that use a deep convolution neural network and provide real-time feedback to the BO. We validated our framework using these two feedback functions on three urinary bladder phantoms. We obtained over 50% increase in sample efficiency for 6D control of the robotized probe. Furthermore, our results indicate that this performance enhancement in BO is independent of the specific training dataset, demonstrating inter-patient adaptability.
[ "Deepak Raina", "SH Chandrashekhara", "Richard Voyles", "Juan Wachs", "Subir Kumar Saha" ]
2023-10-11 11:20:35
http://arxiv.org/abs/2310.07392v1
http://arxiv.org/pdf/2310.07392v1
2310.07392v1
Histopathological Image Classification and Vulnerability Analysis using Federated Learning
Healthcare is one of the foremost applications of machine learning (ML). Traditionally, ML models are trained by central servers, which aggregate data from various distributed devices to forecast the results for newly generated data. This is a major concern as models can access sensitive user information, which raises privacy concerns. A federated learning (FL) approach can help address this issue: A global model sends its copy to all clients who train these copies, and the clients send the updates (weights) back to it. Over time, the global model improves and becomes more accurate. Data privacy is protected during training, as it is conducted locally on the clients' devices. However, the global model is susceptible to data poisoning. We develop a privacy-preserving FL technique for a skin cancer dataset and show that the model is prone to data poisoning attacks. Ten clients train the model, but one of them intentionally introduces flipped labels as an attack. This reduces the accuracy of the global model. As the percentage of label flipping increases, there is a noticeable decrease in accuracy. We use a stochastic gradient descent optimization algorithm to find the most optimal accuracy for the model. Although FL can protect user privacy for healthcare diagnostics, it is also vulnerable to data poisoning, which must be addressed.
[ "Sankalp Vyas", "Amar Nath Patra", "Raj Mani Shukla" ]
2023-10-11 10:55:14
http://arxiv.org/abs/2310.07380v1
http://arxiv.org/pdf/2310.07380v1
2310.07380v1
Causal Unsupervised Semantic Segmentation
Unsupervised semantic segmentation aims to achieve high-quality semantic grouping without human-labeled annotations. With the advent of self-supervised pre-training, various frameworks utilize the pre-trained features to train prediction heads for unsupervised dense prediction. However, a significant challenge in this unsupervised setup is determining the appropriate level of clustering required for segmenting concepts. To address it, we propose a novel framework, CAusal Unsupervised Semantic sEgmentation (CAUSE), which leverages insights from causal inference. Specifically, we bridge intervention-oriented approach (i.e., frontdoor adjustment) to define suitable two-step tasks for unsupervised prediction. The first step involves constructing a concept clusterbook as a mediator, which represents possible concept prototypes at different levels of granularity in a discretized form. Then, the mediator establishes an explicit link to the subsequent concept-wise self-supervised learning for pixel-level grouping. Through extensive experiments and analyses on various datasets, we corroborate the effectiveness of CAUSE and achieve state-of-the-art performance in unsupervised semantic segmentation.
[ "Junho Kim", "Byung-Kwan Lee", "Yong Man Ro" ]
2023-10-11 10:54:44
http://arxiv.org/abs/2310.07379v1
http://arxiv.org/pdf/2310.07379v1
2310.07379v1
Experimental quantum natural gradient optimization in photonics
Variational quantum algorithms (VQAs) combining the advantages of parameterized quantum circuits and classical optimizers, promise practical quantum applications in the Noisy Intermediate-Scale Quantum era. The performance of VQAs heavily depends on the optimization method. Compared with gradient-free and ordinary gradient descent methods, the quantum natural gradient (QNG), which mirrors the geometric structure of the parameter space, can achieve faster convergence and avoid local minima more easily, thereby reducing the cost of circuit executions. We utilized a fully programmable photonic chip to experimentally estimate the QNG in photonics for the first time. We obtained the dissociation curve of the He-H$^+$ cation and achieved chemical accuracy, verifying the outperformance of QNG optimization on a photonic device. Our work opens up a vista of utilizing QNG in photonics to implement practical near-term quantum applications.
[ "Yizhi Wang", "Shichuan Xue", "Yaxuan Wang", "Jiangfang Ding", "Weixu Shi", "Dongyang Wang", "Yong Liu", "Yingwen Liu", "Xiang Fu", "Guangyao Huang", "Anqi Huang", "Mingtang Deng", "Junjie Wu" ]
2023-10-11 10:41:51
http://arxiv.org/abs/2310.07371v1
http://arxiv.org/pdf/2310.07371v1
2310.07371v1
Orthogonal Random Features: Explicit Forms and Sharp Inequalities
Random features have been introduced to scale up kernel methods via randomization techniques. In particular, random Fourier features and orthogonal random features were used to approximate the popular Gaussian kernel. The former is performed by a random Gaussian matrix and leads exactly to the Gaussian kernel after averaging. In this work, we analyze the bias and the variance of the kernel approximation based on orthogonal random features which makes use of Haar orthogonal matrices. We provide explicit expressions for these quantities using normalized Bessel functions and derive sharp exponential bounds supporting the view that orthogonal random features are more informative than random Fourier features.
[ "Nizar Demni", "Hachem Kadri" ]
2023-10-11 10:40:43
http://arxiv.org/abs/2310.07370v1
http://arxiv.org/pdf/2310.07370v1
2310.07370v1
Improved Analysis of Sparse Linear Regression in Local Differential Privacy Model
In this paper, we revisit the problem of sparse linear regression in the local differential privacy (LDP) model. Existing research in the non-interactive and sequentially local models has focused on obtaining the lower bounds for the case where the underlying parameter is $1$-sparse, and extending such bounds to the more general $k$-sparse case has proven to be challenging. Moreover, it is unclear whether efficient non-interactive LDP (NLDP) algorithms exist. To address these issues, we first consider the problem in the $\epsilon$ non-interactive LDP model and provide a lower bound of $\Omega(\frac{\sqrt{dk\log d}}{\sqrt{n}\epsilon})$ on the $\ell_2$-norm estimation error for sub-Gaussian data, where $n$ is the sample size and $d$ is the dimension of the space. We propose an innovative NLDP algorithm, the very first of its kind for the problem. As a remarkable outcome, this algorithm also yields a novel and highly efficient estimator as a valuable by-product. Our algorithm achieves an upper bound of $\tilde{O}({\frac{d\sqrt{k}}{\sqrt{n}\epsilon}})$ for the estimation error when the data is sub-Gaussian, which can be further improved by a factor of $O(\sqrt{d})$ if the server has additional public but unlabeled data. For the sequentially interactive LDP model, we show a similar lower bound of $\Omega({\frac{\sqrt{dk}}{\sqrt{n}\epsilon}})$. As for the upper bound, we rectify a previous method and show that it is possible to achieve a bound of $\tilde{O}(\frac{k\sqrt{d}}{\sqrt{n}\epsilon})$. Our findings reveal fundamental differences between the non-private case, central DP model, and local DP model in the sparse linear regression problem.
[ "Liyang Zhu", "Meng Ding", "Vaneet Aggarwal", "Jinhui Xu", "Di Wang" ]
2023-10-11 10:34:52
http://arxiv.org/abs/2310.07367v1
http://arxiv.org/pdf/2310.07367v1
2310.07367v1
GraphControl: Adding Conditional Control to Universal Graph Pre-trained Models for Graph Domain Transfer Learning
Graph-structured data is ubiquitous in the world which models complex relationships between objects, enabling various Web applications. Daily influxes of unlabeled graph data on the Web offer immense potential for these applications. Graph self-supervised algorithms have achieved significant success in acquiring generic knowledge from abundant unlabeled graph data. These pre-trained models can be applied to various downstream Web applications, saving training time and improving downstream (target) performance. However, different graphs, even across seemingly similar domains, can differ significantly in terms of attribute semantics, posing difficulties, if not infeasibility, for transferring the pre-trained models to downstream tasks. Concretely speaking, for example, the additional task-specific node information in downstream tasks (specificity) is usually deliberately omitted so that the pre-trained representation (transferability) can be leveraged. The trade-off as such is termed as "transferability-specificity dilemma" in this work. To address this challenge, we introduce an innovative deployment module coined as GraphControl, motivated by ControlNet, to realize better graph domain transfer learning. Specifically, by leveraging universal structural pre-trained models and GraphControl, we align the input space across various graphs and incorporate unique characteristics of target data as conditional inputs. These conditions will be progressively integrated into the model during fine-tuning or prompt tuning through ControlNet, facilitating personalized deployment. Extensive experiments show that our method significantly enhances the adaptability of pre-trained models on target attributed datasets, achieving 1.4-3x performance gain. Furthermore, it outperforms training-from-scratch methods on target data with a comparable margin and exhibits faster convergence.
[ "Yun Zhu", "Yaoke Wang", "Haizhou Shi", "Zhenshuo Zhang", "Siliang Tang" ]
2023-10-11 10:30:49
http://arxiv.org/abs/2310.07365v2
http://arxiv.org/pdf/2310.07365v2
2310.07365v2
Diagnosing Bipolar Disorder from 3-D Structural Magnetic Resonance Images Using a Hybrid GAN-CNN Method
Bipolar Disorder (BD) is a psychiatric condition diagnosed by repetitive cycles of hypomania and depression. Since diagnosing BD relies on subjective behavioral assessments over a long period, a solid diagnosis based on objective criteria is not straightforward. The current study responded to the described obstacle by proposing a hybrid GAN-CNN model to diagnose BD from 3-D structural MRI Images (sMRI). The novelty of this study stems from diagnosing BD from sMRI samples rather than conventional datasets such as functional MRI (fMRI), electroencephalography (EEG), and behavioral symptoms while removing the data insufficiency usually encountered when dealing with sMRI samples. The impact of various augmentation ratios is also tested using 5-fold cross-validation. Based on the results, this study obtains an accuracy rate of 75.8%, a sensitivity of 60.3%, and a specificity of 82.5%, which are 3-5% higher than prior work while utilizing less than 6% sample counts. Next, it is demonstrated that a 2- D layer-based GAN generator can effectively reproduce complex 3D brain samples, a more straightforward technique than manual image processing. Lastly, the optimum augmentation threshold for the current study using 172 sMRI samples is 50%, showing the applicability of the described method for larger sMRI datasets. In conclusion, it is established that data augmentation using GAN improves the accuracy of the CNN classifier using sMRI samples, thus developing more reliable decision support systems to assist practitioners in identifying BD patients more reliably and in a shorter period
[ "Masood Hamed Saghayan", "Mohammad Hossein Zolfagharnasab", "Ali Khadem", "Farzam Matinfar", "Hassan Rashidi" ]
2023-10-11 10:17:41
http://arxiv.org/abs/2310.07359v1
http://arxiv.org/pdf/2310.07359v1
2310.07359v1
IMITATE: Clinical Prior Guided Hierarchical Vision-Language Pre-training
In the field of medical Vision-Language Pre-training (VLP), significant efforts have been devoted to deriving text and image features from both clinical reports and associated medical images. However, most existing methods may have overlooked the opportunity in leveraging the inherent hierarchical structure of clinical reports, which are generally split into `findings' for descriptive content and `impressions' for conclusive observation. Instead of utilizing this rich, structured format, current medical VLP approaches often simplify the report into either a unified entity or fragmented tokens. In this work, we propose a novel clinical prior guided VLP framework named IMITATE to learn the structure information from medical reports with hierarchical vision-language alignment. The framework derives multi-level visual features from the chest X-ray (CXR) images and separately aligns these features with the descriptive and the conclusive text encoded in the hierarchical medical report. Furthermore, a new clinical-informed contrastive loss is introduced for cross-modal learning, which accounts for clinical prior knowledge in formulating sample correlations in contrastive learning. The proposed model, IMITATE, outperforms baseline VLP methods across six different datasets, spanning five medical imaging downstream tasks. Comprehensive experimental results highlight the advantages of integrating the hierarchical structure of medical reports for vision-language alignment.
[ "Che Liu", "Sibo Cheng", "Miaojing Shi", "Anand Shah", "Wenjia Bai", "Rossella Arcucci" ]
2023-10-11 10:12:43
http://arxiv.org/abs/2310.07355v1
http://arxiv.org/pdf/2310.07355v1
2310.07355v1
Atom-Motif Contrastive Transformer for Molecular Property Prediction
Recently, Graph Transformer (GT) models have been widely used in the task of Molecular Property Prediction (MPP) due to their high reliability in characterizing the latent relationship among graph nodes (i.e., the atoms in a molecule). However, most existing GT-based methods usually explore the basic interactions between pairwise atoms, and thus they fail to consider the important interactions among critical motifs (e.g., functional groups consisted of several atoms) of molecules. As motifs in a molecule are significant patterns that are of great importance for determining molecular properties (e.g., toxicity and solubility), overlooking motif interactions inevitably hinders the effectiveness of MPP. To address this issue, we propose a novel Atom-Motif Contrastive Transformer (AMCT), which not only explores the atom-level interactions but also considers the motif-level interactions. Since the representations of atoms and motifs for a given molecule are actually two different views of the same instance, they are naturally aligned to generate the self-supervisory signals for model training. Meanwhile, the same motif can exist in different molecules, and hence we also employ the contrastive loss to maximize the representation agreement of identical motifs across different molecules. Finally, in order to clearly identify the motifs that are critical in deciding the properties of each molecule, we further construct a property-aware attention mechanism into our learning framework. Our proposed AMCT is extensively evaluated on seven popular benchmark datasets, and both quantitative and qualitative results firmly demonstrate its effectiveness when compared with the state-of-the-art methods.
[ "Wentao Yu", "Shuo Chen", "Chen Gong", "Gang Niu", "Masashi Sugiyama" ]
2023-10-11 10:03:10
http://arxiv.org/abs/2310.07351v1
http://arxiv.org/pdf/2310.07351v1
2310.07351v1
Fast-ELECTRA for Efficient Pre-training
ELECTRA pre-trains language models by detecting tokens in a sequence that have been replaced by an auxiliary model. Although ELECTRA offers a significant boost in efficiency, its potential is constrained by the training cost brought by the auxiliary model. Notably, this model, which is jointly trained with the main model, only serves to assist the training of the main model and is discarded post-training. This results in a substantial amount of training cost being expended in vain. To mitigate this issue, we propose Fast-ELECTRA, which leverages an existing language model as the auxiliary model. To construct a learning curriculum for the main model, we smooth its output distribution via temperature scaling following a descending schedule. Our approach rivals the performance of state-of-the-art ELECTRA-style pre-training methods, while significantly eliminating the computation and memory cost brought by the joint training of the auxiliary model. Our method also reduces the sensitivity to hyper-parameters and enhances the pre-training stability.
[ "Chengyu Dong", "Liyuan Liu", "Hao Cheng", "Jingbo Shang", "Jianfeng Gao", "Xiaodong Liu" ]
2023-10-11 09:55:46
http://arxiv.org/abs/2310.07347v1
http://arxiv.org/pdf/2310.07347v1
2310.07347v1
Towards Foundation Models for Learning on Tabular Data
Learning on tabular data underpins numerous real-world applications. Despite considerable efforts in developing effective learning models for tabular data, current transferable tabular models remain in their infancy, limited by either the lack of support for direct instruction following in new tasks or the neglect of acquiring foundational knowledge and capabilities from diverse tabular datasets. In this paper, we propose Tabular Foundation Models (TabFMs) to overcome these limitations. TabFMs harness the potential of generative tabular learning, employing a pre-trained large language model (LLM) as the base model and fine-tuning it using purpose-designed objectives on an extensive range of tabular datasets. This approach endows TabFMs with a profound understanding and universal capabilities essential for learning on tabular data. Our evaluations underscore TabFM's effectiveness: not only does it significantly excel in instruction-following tasks like zero-shot and in-context inference, but it also showcases performance that approaches, and in instances, even transcends, the renowned yet mysterious closed-source LLMs like GPT-4. Furthermore, when fine-tuning with scarce data, our model achieves remarkable efficiency and maintains competitive performance with abundant training data. Finally, while our results are promising, we also delve into TabFM's limitations and potential opportunities, aiming to stimulate and expedite future research on developing more potent TabFMs.
[ "Han Zhang", "Xumeng Wen", "Shun Zheng", "Wei Xu", "Jiang Bian" ]
2023-10-11 09:37:38
http://arxiv.org/abs/2310.07338v2
http://arxiv.org/pdf/2310.07338v2
2310.07338v2
Exploring Social Motion Latent Space and Human Awareness for Effective Robot Navigation in Crowded Environments
This work proposes a novel approach to social robot navigation by learning to generate robot controls from a social motion latent space. By leveraging this social motion latent space, the proposed method achieves significant improvements in social navigation metrics such as success rate, navigation time, and trajectory length while producing smoother (less jerk and angular deviations) and more anticipatory trajectories. The superiority of the proposed method is demonstrated through comparison with baseline models in various scenarios. Additionally, the concept of humans' awareness towards the robot is introduced into the social robot navigation framework, showing that incorporating human awareness leads to shorter and smoother trajectories owing to humans' ability to positively interact with the robot.
[ "Junaid Ahmed Ansari", "Satyajit Tourani", "Gourav Kumar", "Brojeshwar Bhowmick" ]
2023-10-11 09:25:24
http://arxiv.org/abs/2310.07335v1
http://arxiv.org/pdf/2310.07335v1
2310.07335v1
An Adversarial Example for Direct Logit Attribution: Memory Management in gelu-4l
We provide concrete evidence for memory management in a 4-layer transformer. Specifically, we identify clean-up behavior, in which model components consistently remove the output of preceeding components during a forward pass. Our findings suggest that the interpretability technique Direct Logit Attribution provides misleading results. We show explicit examples where this technique is inaccurate, as it does not account for clean-up behavior.
[ "James Dao", "Yeu-Tong Lau", "Can Rager", "Jett Janiak" ]
2023-10-11 09:14:40
http://arxiv.org/abs/2310.07325v2
http://arxiv.org/pdf/2310.07325v2
2310.07325v2
Multichannel consecutive data cross-extraction with 1DCNN-attention for diagnosis of power transformer
Power transformer plays a critical role in grid infrastructure, and its diagnosis is paramount for maintaining stable operation. However, the current methods for transformer diagnosis focus on discrete dissolved gas analysis, neglecting deep feature extraction of multichannel consecutive data. The unutilized sequential data contains the significant temporal information reflecting the transformer condition. In light of this, the structure of multichannel consecutive data cross-extraction (MCDC) is proposed in this article in order to comprehensively exploit the intrinsic characteristic and evaluate the states of transformer. Moreover, for the better accommodation in scenario of transformer diagnosis, one dimensional convolution neural network attention (1DCNN-attention) mechanism is introduced and offers a more efficient solution given the simplified spatial complexity. Finally, the effectiveness of MCDC and the superior generalization ability, compared with other algorithms, are validated in experiments conducted on a dataset collected from real operation cases of power transformer. Additionally, the better stability of 1DCNN-attention has also been certified.
[ "Wei Zheng", "Guogang Zhang", "Chenchen Zhao", "Qianqian Zhu" ]
2023-10-11 09:14:17
http://arxiv.org/abs/2310.07323v1
http://arxiv.org/pdf/2310.07323v1
2310.07323v1
On the Impact of Cross-Domain Data on German Language Models
Traditionally, large language models have been either trained on general web crawls or domain-specific data. However, recent successes of generative large language models, have shed light on the benefits of cross-domain datasets. To examine the significance of prioritizing data diversity over quality, we present a German dataset comprising texts from five domains, along with another dataset aimed at containing high-quality data. Through training a series of models ranging between 122M and 750M parameters on both datasets, we conduct a comprehensive benchmark on multiple downstream tasks. Our findings demonstrate that the models trained on the cross-domain dataset outperform those trained on quality data alone, leading to improvements up to $4.45\%$ over the previous state-of-the-art. The models are available at https://huggingface.co/ikim-uk-essen
[ "Amin Dada", "Aokun Chen", "Cheng Peng", "Kaleb E Smith", "Ahmad Idrissi-Yaghir", "Constantin Marc Seibold", "Jianning Li", "Lars Heiliger", "Xi Yang", "Christoph M. Friedrich", "Daniel Truhn", "Jan Egger", "Jiang Bian", "Jens Kleesiek", "Yonghui Wu" ]
2023-10-11 09:09:55
http://arxiv.org/abs/2310.07321v2
http://arxiv.org/pdf/2310.07321v2
2310.07321v2
Byzantine-Resilient Decentralized Multi-Armed Bandits
In decentralized cooperative multi-armed bandits (MAB), each agent observes a distinct stream of rewards, and seeks to exchange information with others to select a sequence of arms so as to minimize its regret. Agents in the cooperative setting can outperform a single agent running a MAB method such as Upper-Confidence Bound (UCB) independently. In this work, we study how to recover such salient behavior when an unknown fraction of the agents can be Byzantine, that is, communicate arbitrarily wrong information in the form of reward mean-estimates or confidence sets. This framework can be used to model attackers in computer networks, instigators of offensive content into recommender systems, or manipulators of financial markets. Our key contribution is the development of a fully decentralized resilient upper confidence bound (UCB) algorithm that fuses an information mixing step among agents with a truncation of inconsistent and extreme values. This truncation step enables us to establish that the performance of each normal agent is no worse than the classic single-agent UCB1 algorithm in terms of regret, and more importantly, the cumulative regret of all normal agents is strictly better than the non-cooperative case, provided that each agent has at least 3f+1 neighbors where f is the maximum possible Byzantine agents in each agent's neighborhood. Extensions to time-varying neighbor graphs, and minimax lower bounds are further established on the achievable regret. Experiments corroborate the merits of this framework in practice.
[ "Jingxuan Zhu", "Alec Koppel", "Alvaro Velasquez", "Ji Liu" ]
2023-10-11 09:09:50
http://arxiv.org/abs/2310.07320v1
http://arxiv.org/pdf/2310.07320v1
2310.07320v1
Molecule-Edit Templates for Efficient and Accurate Retrosynthesis Prediction
Retrosynthesis involves determining a sequence of reactions to synthesize complex molecules from simpler precursors. As this poses a challenge in organic chemistry, machine learning has offered solutions, particularly for predicting possible reaction substrates for a given target molecule. These solutions mainly fall into template-based and template-free categories. The former is efficient but relies on a vast set of predefined reaction patterns, while the latter, though more flexible, can be computationally intensive and less interpretable. To address these issues, we introduce METRO (Molecule-Edit Templates for RetrOsynthesis), a machine-learning model that predicts reactions using minimal templates - simplified reaction patterns capturing only essential molecular changes - reducing computational overhead and achieving state-of-the-art results on standard benchmarks.
[ "Mikołaj Sacha", "Michał Sadowski", "Piotr Kozakowski", "Ruard van Workum", "Stanisław Jastrzębski" ]
2023-10-11 09:00:02
http://arxiv.org/abs/2310.07313v1
http://arxiv.org/pdf/2310.07313v1
2310.07313v1
WiGenAI: The Symphony of Wireless and Generative AI via Diffusion Models
Innovative foundation models, such as GPT-3 and stable diffusion models, have made a paradigm shift in the realm of artificial intelligence (AI) towards generative AI-based systems. In unison, from data communication and networking perspective, AI and machine learning (AI/ML) algorithms are envisioned to be pervasively incorporated into the future generations of wireless communications systems, highlighting the need for novel AI-native solutions for the emergent communication scenarios. In this article, we outline the applications of generative AI in wireless communication systems to lay the foundations for research in this field. Diffusion-based generative models, as the new state-of-the-art paradigm of generative models, are introduced, and their applications in wireless communication systems are discussed. Two case studies are also presented to showcase how diffusion models can be exploited for the development of resilient AI-native communication systems. Specifically, we propose denoising diffusion probabilistic models (DDPM) for a wireless communication scheme with non-ideal transceivers, where 30% improvement is achieved in terms of bit error rate. As the second application, DDPMs are employed at the transmitter to shape the constellation symbols, highlighting a robust out-of-distribution performance. Finally, future directions and open issues for the development of generative AI-based wireless systems are discussed to promote future research endeavors towards wireless generative AI (WiGenAI).
[ "Mehdi Letafati", "Samad Ali", "Matti Latva-aho" ]
2023-10-11 08:57:59
http://arxiv.org/abs/2310.07312v2
http://arxiv.org/pdf/2310.07312v2
2310.07312v2
SNOiC: Soft Labeling and Noisy Mixup based Open Intent Classification Model
This paper presents a Soft Labeling and Noisy Mixup-based open intent classification model (SNOiC). Most of the previous works have used threshold-based methods to identify open intents, which are prone to overfitting and may produce biased predictions. Additionally, the need for more available data for an open intent class presents another limitation for these existing models. SNOiC combines Soft Labeling and Noisy Mixup strategies to reduce the biasing and generate pseudo-data for open intent class. The experimental results on four benchmark datasets show that the SNOiC model achieves a minimum and maximum performance of 68.72\% and 94.71\%, respectively, in identifying open intents. Moreover, compared to state-of-the-art models, the SNOiC model improves the performance of identifying open intents by 0.93\% (minimum) and 12.76\% (maximum). The model's efficacy is further established by analyzing various parameters used in the proposed model. An ablation study is also conducted, which involves creating three model variants to validate the effectiveness of the SNOiC model.
[ "Aditi Kanwar", "Aditi Seetha", "Satyendra Singh Chouhan", "Rajdeep Niyogi" ]
2023-10-11 08:40:06
http://arxiv.org/abs/2310.07306v1
http://arxiv.org/pdf/2310.07306v1
2310.07306v1
Beyond Memorization: Violating Privacy Via Inference with Large Language Models
Current privacy research on large language models (LLMs) primarily focuses on the issue of extracting memorized training data. At the same time, models' inference capabilities have increased drastically. This raises the key question of whether current LLMs could violate individuals' privacy by inferring personal attributes from text given at inference time. In this work, we present the first comprehensive study on the capabilities of pretrained LLMs to infer personal attributes from text. We construct a dataset consisting of real Reddit profiles, and show that current LLMs can infer a wide range of personal attributes (e.g., location, income, sex), achieving up to $85\%$ top-1 and $95.8\%$ top-3 accuracy at a fraction of the cost ($100\times$) and time ($240\times$) required by humans. As people increasingly interact with LLM-powered chatbots across all aspects of life, we also explore the emerging threat of privacy-invasive chatbots trying to extract personal information through seemingly benign questions. Finally, we show that common mitigations, i.e., text anonymization and model alignment, are currently ineffective at protecting user privacy against LLM inference. Our findings highlight that current LLMs can infer personal data at a previously unattainable scale. In the absence of working defenses, we advocate for a broader discussion around LLM privacy implications beyond memorization, striving for a wider privacy protection.
[ "Robin Staab", "Mark Vero", "Mislav Balunović", "Martin Vechev" ]
2023-10-11 08:32:46
http://arxiv.org/abs/2310.07298v1
http://arxiv.org/pdf/2310.07298v1
2310.07298v1
Score Regularized Policy Optimization through Diffusion Behavior
Recent developments in offline reinforcement learning have uncovered the immense potential of diffusion modeling, which excels at representing heterogeneous behavior policies. However, sampling from diffusion policies is considerably slow because it necessitates tens to hundreds of iterative inference steps for one action. To address this issue, we propose to extract an efficient deterministic inference policy from critic models and pretrained diffusion behavior models, leveraging the latter to directly regularize the policy gradient with the behavior distribution's score function during optimization. Our method enjoys powerful generative capabilities of diffusion modeling while completely circumventing the computationally intensive and time-consuming diffusion sampling scheme, both during training and evaluation. Extensive results on D4RL tasks show that our method boosts action sampling speed by more than 25 times compared with various leading diffusion-based methods in locomotion tasks, while still maintaining state-of-the-art performance.
[ "Huayu Chen", "Cheng Lu", "Zhengyi Wang", "Hang Su", "Jun Zhu" ]
2023-10-11 08:31:26
http://arxiv.org/abs/2310.07297v2
http://arxiv.org/pdf/2310.07297v2
2310.07297v2
BioT5: Enriching Cross-modal Integration in Biology with Chemical Knowledge and Natural Language Associations
Recent advancements in biological research leverage the integration of molecules, proteins, and natural language to enhance drug discovery. However, current models exhibit several limitations, such as the generation of invalid molecular SMILES, underutilization of contextual information, and equal treatment of structured and unstructured knowledge. To address these issues, we propose $\mathbf{BioT5}$, a comprehensive pre-training framework that enriches cross-modal integration in biology with chemical knowledge and natural language associations. $\mathbf{BioT5}$ utilizes SELFIES for $100%$ robust molecular representations and extracts knowledge from the surrounding context of bio-entities in unstructured biological literature. Furthermore, $\mathbf{BioT5}$ distinguishes between structured and unstructured knowledge, leading to more effective utilization of information. After fine-tuning, BioT5 shows superior performance across a wide range of tasks, demonstrating its strong capability of capturing underlying relations and properties of bio-entities. Our code is available at $\href{https://github.com/QizhiPei/BioT5}{Github}$.
[ "Qizhi Pei", "Wei Zhang", "Jinhua Zhu", "Kehan Wu", "Kaiyuan Gao", "Lijun Wu", "Yingce Xia", "Rui Yan" ]
2023-10-11 07:57:08
http://arxiv.org/abs/2310.07276v2
http://arxiv.org/pdf/2310.07276v2
2310.07276v2
Why Does Sharpness-Aware Minimization Generalize Better Than SGD?
The challenge of overfitting, in which the model memorizes the training data and fails to generalize to test data, has become increasingly significant in the training of large neural networks. To tackle this challenge, Sharpness-Aware Minimization (SAM) has emerged as a promising training method, which can improve the generalization of neural networks even in the presence of label noise. However, a deep understanding of how SAM works, especially in the setting of nonlinear neural networks and classification tasks, remains largely missing. This paper fills this gap by demonstrating why SAM generalizes better than Stochastic Gradient Descent (SGD) for a certain data model and two-layer convolutional ReLU networks. The loss landscape of our studied problem is nonsmooth, thus current explanations for the success of SAM based on the Hessian information are insufficient. Our result explains the benefits of SAM, particularly its ability to prevent noise learning in the early stages, thereby facilitating more effective learning of features. Experiments on both synthetic and real data corroborate our theory.
[ "Zixiang Chen", "Junkai Zhang", "Yiwen Kou", "Xiangning Chen", "Cho-Jui Hsieh", "Quanquan Gu" ]
2023-10-11 07:51:10
http://arxiv.org/abs/2310.07269v1
http://arxiv.org/pdf/2310.07269v1
2310.07269v1
RaftFed: A Lightweight Federated Learning Framework for Vehicular Crowd Intelligence
Vehicular crowd intelligence (VCI) is an emerging research field. Facilitated by state-of-the-art vehicular ad-hoc networks and artificial intelligence, various VCI applications come to place, e.g., collaborative sensing, positioning, and mapping. The collaborative property of VCI applications generally requires data to be shared among participants, thus forming network-wide intelligence. How to fulfill this process without compromising data privacy remains a challenging issue. Although federated learning (FL) is a promising tool to solve the problem, adapting conventional FL frameworks to VCI is nontrivial. First, the centralized model aggregation is unreliable in VCI because of the existence of stragglers with unfavorable channel conditions. Second, existing FL schemes are vulnerable to Non-IID data, which is intensified by the data heterogeneity in VCI. This paper proposes a novel federated learning framework called RaftFed to facilitate privacy-preserving VCI. The experimental results show that RaftFed performs better than baselines regarding communication overhead, model accuracy, and model convergence.
[ "Changan Yang", "Yaxing Chen", "Yao Zhang", "Helei Cui", "Zhiwen Yu", "Bin Guo", "Zheng Yan", "Zijiang Yang" ]
2023-10-11 07:50:51
http://arxiv.org/abs/2310.07268v1
http://arxiv.org/pdf/2310.07268v1
2310.07268v1
Classification of Dysarthria based on the Levels of Severity. A Systematic Review
Dysarthria is a neurological speech disorder that can significantly impact affected individuals' communication abilities and overall quality of life. The accurate and objective classification of dysarthria and the determination of its severity are crucial for effective therapeutic intervention. While traditional assessments by speech-language pathologists (SLPs) are common, they are often subjective, time-consuming, and can vary between practitioners. Emerging machine learning-based models have shown the potential to provide a more objective dysarthria assessment, enhancing diagnostic accuracy and reliability. This systematic review aims to comprehensively analyze current methodologies for classifying dysarthria based on severity levels. Specifically, this review will focus on determining the most effective set and type of features that can be used for automatic patient classification and evaluating the best AI techniques for this purpose. We will systematically review the literature on the automatic classification of dysarthria severity levels. Sources of information will include electronic databases and grey literature. Selection criteria will be established based on relevance to the research questions. Data extraction will include methodologies used, the type of features extracted for classification, and AI techniques employed. The findings of this systematic review will contribute to the current understanding of dysarthria classification, inform future research, and support the development of improved diagnostic tools. The implications of these findings could be significant in advancing patient care and improving therapeutic outcomes for individuals affected by dysarthria.
[ "Afnan Al-Ali", "Somaya Al-Maadeed", "Moutaz Saleh", "Rani Chinnappa Naidu", "Zachariah C Alex", "Prakash Ramachandran", "Rajeev Khoodeeram", "Rajesh Kumar M" ]
2023-10-11 07:40:46
http://arxiv.org/abs/2310.07264v1
http://arxiv.org/pdf/2310.07264v1
2310.07264v1
Deep ReLU networks and high-order finite element methods II: Chebyshev emulation
Expression rates and stability in Sobolev norms of deep ReLU neural networks (NNs) in terms of the number of parameters defining the NN for continuous, piecewise polynomial functions, on arbitrary, finite partitions $\mathcal{T}$ of a bounded interval $(a,b)$ are addressed. Novel constructions of ReLU NN surrogates encoding the approximated functions in terms of Chebyshev polynomial expansion coefficients are developed. Chebyshev coefficients can be computed easily from the values of the function in the Clenshaw--Curtis points using the inverse fast Fourier transform. Bounds on expression rates and stability that are superior to those of constructions based on ReLU NN emulations of monomials considered in [Opschoor, Petersen, Schwab, 2020] are obtained. All emulation bounds are explicit in terms of the (arbitrary) partition of the interval, the target emulation accuracy and the polynomial degree in each element of the partition. ReLU NN emulation error estimates are provided for various classes of functions and norms, commonly encountered in numerical analysis. In particular, we show exponential ReLU emulation rate bounds for analytic functions with point singularities and develop an interface between Chebfun approximations and constructive ReLU NN emulations.
[ "Joost A. A. Opschoor", "Christoph Schwab" ]
2023-10-11 07:38:37
http://arxiv.org/abs/2310.07261v1
http://arxiv.org/pdf/2310.07261v1
2310.07261v1
ADMEOOD: Out-of-Distribution Benchmark for Drug Property Prediction
Obtaining accurate and valid information for drug molecules is a crucial and challenging task. However, chemical knowledge and information have been accumulated over the past 100 years from various regions, laboratories, and experimental purposes. Little has been explored in terms of the out-of-distribution (OOD) problem with noise and inconsistency, which may lead to weak robustness and unsatisfied performance. This study proposes a novel benchmark ADMEOOD, a systematic OOD dataset curator and benchmark specifically designed for drug property prediction. ADMEOOD obtained 27 ADME (Absorption, Distribution, Metabolism, Excretion) drug properties from Chembl and relevant literature. Additionally, it includes two kinds of OOD data shifts: Noise Shift and Concept Conflict Drift (CCD). Noise Shift responds to the noise level by categorizing the environment into different confidence levels. On the other hand, CCD describes the data which has inconsistent label among the original data. Finally, it tested on a variety of domain generalization models, and the experimental results demonstrate the effectiveness of the proposed partition method in ADMEOOD: ADMEOOD demonstrates a significant difference performance between in-distribution and out-of-distribution data. Moreover, ERM (Empirical Risk Minimization) and other models exhibit distinct trends in performance across different domains and measurement types.
[ "Shuoying Wei", "Xinlong Wen", "Lida Zhu", "Songquan Li", "Rongbo Zhu" ]
2023-10-11 07:30:18
http://arxiv.org/abs/2310.07253v1
http://arxiv.org/pdf/2310.07253v1
2310.07253v1
A Comparative Study of Pre-trained CNNs and GRU-Based Attention for Image Caption Generation
Image captioning is a challenging task involving generating a textual description for an image using computer vision and natural language processing techniques. This paper proposes a deep neural framework for image caption generation using a GRU-based attention mechanism. Our approach employs multiple pre-trained convolutional neural networks as the encoder to extract features from the image and a GRU-based language model as the decoder to generate descriptive sentences. To improve performance, we integrate the Bahdanau attention model with the GRU decoder to enable learning to focus on specific image parts. We evaluate our approach using the MSCOCO and Flickr30k datasets and show that it achieves competitive scores compared to state-of-the-art methods. Our proposed framework can bridge the gap between computer vision and natural language and can be extended to specific domains.
[ "Rashid Khan", "Bingding Huang", "Haseeb Hassan", "Asim Zaman", "Zhongfu Ye" ]
2023-10-11 07:30:01
http://arxiv.org/abs/2310.07252v1
http://arxiv.org/pdf/2310.07252v1
2310.07252v1
Synthesizing Missing MRI Sequences from Available Modalities using Generative Adversarial Networks in BraTS Dataset
Glioblastoma is a highly aggressive and lethal form of brain cancer. Magnetic resonance imaging (MRI) plays a significant role in the diagnosis, treatment planning, and follow-up of glioblastoma patients due to its non-invasive and radiation-free nature. The International Brain Tumor Segmentation (BraTS) challenge has contributed to generating numerous AI algorithms to accurately and efficiently segment glioblastoma sub-compartments using four structural (T1, T1Gd, T2, T2-FLAIR) MRI scans. However, these four MRI sequences may not always be available. To address this issue, Generative Adversarial Networks (GANs) can be used to synthesize the missing MRI sequences. In this paper, we implement and utilize an open-source GAN approach that takes any three MRI sequences as input to generate the missing fourth structural sequence. Our proposed approach is contributed to the community-driven generally nuanced deep learning framework (GaNDLF) and demonstrates promising results in synthesizing high-quality and realistic MRI sequences, enabling clinicians to improve their diagnostic capabilities and support the application of AI methods to brain tumor MRI quantification.
[ "Ibrahim Ethem Hamamci" ]
2023-10-11 07:27:28
http://arxiv.org/abs/2310.07250v2
http://arxiv.org/pdf/2310.07250v2
2310.07250v2
Crowd Counting in Harsh Weather using Image Denoising with Pix2Pix GANs
Visual crowd counting estimates the density of the crowd using deep learning models such as convolution neural networks (CNNs). The performance of the model heavily relies on the quality of the training data that constitutes crowd images. In harsh weather such as fog, dust, and low light conditions, the inference performance may severely degrade on the noisy and blur images. In this paper, we propose the use of Pix2Pix generative adversarial network (GAN) to first denoise the crowd images prior to passing them to the counting model. A Pix2Pix network is trained using synthetic noisy images generated from original crowd images and then the pretrained generator is then used in the inference engine to estimate the crowd density in unseen, noisy crowd images. The performance is tested on JHU-Crowd dataset to validate the significance of the proposed method particularly when high reliability and accuracy are required.
[ "Muhammad Asif Khan", "Hamid Menouar", "Ridha Hamila" ]
2023-10-11 07:22:37
http://arxiv.org/abs/2310.07245v1
http://arxiv.org/pdf/2310.07245v1
2310.07245v1
Surrogate modeling for stochastic crack growth processes in structural health monitoring applications
Fatigue crack growth is one of the most common types of deterioration in metal structures with significant implications on their reliability. Recent advances in Structural Health Monitoring (SHM) have motivated the use of structural response data to predict future crack growth under uncertainty, in order to enable a transition towards predictive maintenance. Accurately representing different sources of uncertainty in stochastic crack growth (SCG) processes is a non-trivial task. The present work builds on previous research on physics-based SCG modeling under both material and load-related uncertainty. The aim here is to construct computationally efficient, probabilistic surrogate models for SCG processes that successfully encode these different sources of uncertainty. An approach inspired by latent variable modeling is employed that utilizes Gaussian Process (GP) regression models to enable the surrogates to be used to generate prior distributions for different Bayesian SHM tasks as the application of interest. Implementation is carried out in a numerical setting and model performance is assessed for two fundamental crack SHM problems; namely crack length monitoring (damage quantification) and crack growth monitoring (damage prognosis).
[ "Nicholas E. Silionis", "Konstantinos N. Anyfantis" ]
2023-10-11 07:13:16
http://arxiv.org/abs/2310.07241v1
http://arxiv.org/pdf/2310.07241v1
2310.07241v1
CacheGen: Fast Context Loading for Language Model Applications
As large language models (LLMs) take on more complex tasks, their inputs incorporate longer contexts to respond to questions that require domain knowledge or user-specific conversational histories. Yet, using long contexts poses a challenge for responsive LLM systems, as nothing can be generated until all the contexts are fetched to and processed by the LLM. Existing systems optimize only the computation delay in context processing (e.g., by caching intermediate key-value features of the text context) but often cause longer network delays in context fetching (e.g., key-value features consume orders of magnitude larger bandwidth than the text context). This paper presents CacheGen to minimize the delays in fetching and processing contexts for LLMs. CacheGen reduces the bandwidth needed for transmitting long contexts' key-value (KV) features through a novel encoder that compresses KV features into more compact bitstream representations. The encoder combines adaptive quantization with a tailored arithmetic coder, taking advantage of the KV features' distributional properties, such as locality across tokens. Furthermore, CacheGen minimizes the total delay in fetching and processing a context by using a controller that determines when to load the context as compressed KV features or raw text and picks the appropriate compression level if loaded as KV features. We test CacheGen on three models of various sizes and three datasets of different context lengths. Compared to recent methods that handle long contexts, CacheGen reduces bandwidth usage by 3.7-4.3x and the total delay in fetching and processing contexts by 2.7-3x while maintaining similar LLM performance on various tasks as loading the text contexts.
[ "Yuhan Liu", "Hanchen Li", "Kuntai Du", "Jiayi Yao", "Yihua Cheng", "Yuyang Huang", "Shan Lu", "Michael Maire", "Henry Hoffmann", "Ari Holtzman", "Ganesh Ananthanarayanan", "Junchen Jiang" ]
2023-10-11 07:08:20
http://arxiv.org/abs/2310.07240v1
http://arxiv.org/pdf/2310.07240v1
2310.07240v1
Are GATs Out of Balance?
While the expressive power and computational capabilities of graph neural networks (GNNs) have been theoretically studied, their optimization and learning dynamics, in general, remain largely unexplored. Our study undertakes the Graph Attention Network (GAT), a popular GNN architecture in which a node's neighborhood aggregation is weighted by parameterized attention coefficients. We derive a conservation law of GAT gradient flow dynamics, which explains why a high portion of parameters in GATs with standard initialization struggle to change during training. This effect is amplified in deeper GATs, which perform significantly worse than their shallow counterparts. To alleviate this problem, we devise an initialization scheme that balances the GAT network. Our approach i) allows more effective propagation of gradients and in turn enables trainability of deeper networks, and ii) attains a considerable speedup in training and convergence time in comparison to the standard initialization. Our main theorem serves as a stepping stone to studying the learning dynamics of positive homogeneous models with attention mechanisms.
[ "Nimrah Mustafa", "Aleksandar Bojchevski", "Rebekka Burkholz" ]
2023-10-11 06:53:05
http://arxiv.org/abs/2310.07235v1
http://arxiv.org/pdf/2310.07235v1
2310.07235v1
Hierarchical Decomposition of Prompt-Based Continual Learning: Rethinking Obscured Sub-optimality
Prompt-based continual learning is an emerging direction in leveraging pre-trained knowledge for downstream continual learning, and has almost reached the performance pinnacle under supervised pre-training. However, our empirical research reveals that the current strategies fall short of their full potential under the more realistic self-supervised pre-training, which is essential for handling vast quantities of unlabeled data in practice. This is largely due to the difficulty of task-specific knowledge being incorporated into instructed representations via prompt parameters and predicted by uninstructed representations at test time. To overcome the exposed sub-optimality, we conduct a theoretical analysis of the continual learning objective in the context of pre-training, and decompose it into hierarchical components: within-task prediction, task-identity inference, and task-adaptive prediction. Following these empirical and theoretical insights, we propose Hierarchical Decomposition (HiDe-)Prompt, an innovative approach that explicitly optimizes the hierarchical components with an ensemble of task-specific prompts and statistics of both uninstructed and instructed representations, further with the coordination of a contrastive regularization strategy. Our extensive experiments demonstrate the superior performance of HiDe-Prompt and its robustness to pre-training paradigms in continual learning (e.g., up to 15.01% and 9.61% lead on Split CIFAR-100 and Split ImageNet-R, respectively). Our code is available at \url{https://github.com/thu-ml/HiDe-Prompt}.
[ "Liyuan Wang", "Jingyi Xie", "Xingxing Zhang", "Mingyi Huang", "Hang Su", "Jun Zhu" ]
2023-10-11 06:51:46
http://arxiv.org/abs/2310.07234v1
http://arxiv.org/pdf/2310.07234v1
2310.07234v1
Self-supervised Pocket Pretraining via Protein Fragment-Surroundings Alignment
Pocket representations play a vital role in various biomedical applications, such as druggability estimation, ligand affinity prediction, and de novo drug design. While existing geometric features and pretrained representations have demonstrated promising results, they usually treat pockets independent of ligands, neglecting the fundamental interactions between them. However, the limited pocket-ligand complex structures available in the PDB database (less than 100 thousand non-redundant pairs) hampers large-scale pretraining endeavors for interaction modeling. To address this constraint, we propose a novel pocket pretraining approach that leverages knowledge from high-resolution atomic protein structures, assisted by highly effective pretrained small molecule representations. By segmenting protein structures into drug-like fragments and their corresponding pockets, we obtain a reasonable simulation of ligand-receptor interactions, resulting in the generation of over 5 million complexes. Subsequently, the pocket encoder is trained in a contrastive manner to align with the representation of pseudo-ligand furnished by some pretrained small molecule encoders. Our method, named ProFSA, achieves state-of-the-art performance across various tasks, including pocket druggability prediction, pocket matching, and ligand binding affinity prediction. Notably, ProFSA surpasses other pretraining methods by a substantial margin. Moreover, our work opens up a new avenue for mitigating the scarcity of protein-ligand complex data through the utilization of high-quality and diverse protein structure databases.
[ "Bowen Gao", "Yinjun Jia", "Yuanle Mo", "Yuyan Ni", "Weiying Ma", "Zhiming Ma", "Yanyan Lan" ]
2023-10-11 06:36:23
http://arxiv.org/abs/2310.07229v1
http://arxiv.org/pdf/2310.07229v1
2310.07229v1
Deep Learning for blind spectral unmixing of LULC classes with MODIS multispectral time series and ancillary data
Remotely sensed data are dominated by mixed Land Use and Land Cover (LULC) types. Spectral unmixing is a technique to extract information from mixed pixels into their constituent LULC types and corresponding abundance fractions. Traditionally, solving this task has relied on either classical methods that require prior knowledge of endmembers or machine learning methods that avoid explicit endmembers calculation, also known as blind spectral unmixing (BSU). Most BSU studies based on Deep Learning (DL) focus on one time-step hyperspectral data, yet its acquisition remains quite costly compared with multispectral data. To our knowledge, here we provide the first study on BSU of LULC classes using multispectral time series data with DL models. We further boost the performance of a Long-Short Term Memory (LSTM)-based model by incorporating geographic plus topographic (geo-topographic) and climatic ancillary information. Our experiments show that combining spectral-temporal input data together with geo-topographic and climatic information substantially improves the abundance estimation of LULC classes in mixed pixels. To carry out this study, we built a new labeled dataset of the region of Andalusia (Spain) with monthly multispectral time series of pixels for the year 2013 from MODIS at 460m resolution, for two hierarchical levels of LULC classes, named Andalusia MultiSpectral MultiTemporal Unmixing (Andalusia-MSMTU). This dataset provides, at the pixel level, a multispectral time series plus ancillary information annotated with the abundance of each LULC class inside each pixel. The dataset and code are available to the public.
[ "José Rodríguez-Ortega", "Rohaifa Khaldi", "Domingo Alcaraz-Segura", "Siham Tabik" ]
2023-10-11 06:13:50
http://arxiv.org/abs/2310.07223v1
http://arxiv.org/pdf/2310.07223v1
2310.07223v1
Using Learnable Physics for Real-Time Exercise Form Recommendations
Good posture and form are essential for safe and productive exercising. Even in gym settings, trainers may not be readily available for feedback. Rehabilitation therapies and fitness workouts can thus benefit from recommender systems that provide real-time evaluation. In this paper, we present an algorithmic pipeline that can diagnose problems in exercise techniques and offer corrective recommendations, with high sensitivity and specificity in real-time. We use MediaPipe for pose recognition, count repetitions using peak-prominence detection, and use a learnable physics simulator to track motion evolution for each exercise. A test video is diagnosed based on deviations from the prototypical learned motion using statistical learning. The system is evaluated on six full and upper body exercises. These real-time recommendations, counseled via low-cost equipment like smartphones, will allow exercisers to rectify potential mistakes making self-practice feasible while reducing the risk of workout injuries.
[ "Abhishek Jaiswal", "Gautam Chauhan", "Nisheeth Srivastava" ]
2023-10-11 06:11:11
http://arxiv.org/abs/2310.07221v1
http://arxiv.org/pdf/2310.07221v1
2310.07221v1
COPlanner: Plan to Roll Out Conservatively but to Explore Optimistically for Model-Based RL
Dyna-style model-based reinforcement learning contains two phases: model rollouts to generate sample for policy learning and real environment exploration using current policy for dynamics model learning. However, due to the complex real-world environment, it is inevitable to learn an imperfect dynamics model with model prediction error, which can further mislead policy learning and result in sub-optimal solutions. In this paper, we propose $\texttt{COPlanner}$, a planning-driven framework for model-based methods to address the inaccurately learned dynamics model problem with conservative model rollouts and optimistic environment exploration. $\texttt{COPlanner}$ leverages an uncertainty-aware policy-guided model predictive control (UP-MPC) component to plan for multi-step uncertainty estimation. This estimated uncertainty then serves as a penalty during model rollouts and as a bonus during real environment exploration respectively, to choose actions. Consequently, $\texttt{COPlanner}$ can avoid model uncertain regions through conservative model rollouts, thereby alleviating the influence of model error. Simultaneously, it explores high-reward model uncertain regions to reduce model error actively through optimistic real environment exploration. $\texttt{COPlanner}$ is a plug-and-play framework that can be applied to any dyna-style model-based methods. Experimental results on a series of proprioceptive and visual continuous control tasks demonstrate that both sample efficiency and asymptotic performance of strong model-based methods are significantly improved combined with $\texttt{COPlanner}$.
[ "Xiyao Wang", "Ruijie Zheng", "Yanchao Sun", "Ruonan Jia", "Wichayaporn Wongkamjan", "Huazhe Xu", "Furong Huang" ]
2023-10-11 06:10:07
http://arxiv.org/abs/2310.07220v1
http://arxiv.org/pdf/2310.07220v1
2310.07220v1
Improved Membership Inference Attacks Against Language Classification Models
Artificial intelligence systems are prevalent in everyday life, with use cases in retail, manufacturing, health, and many other fields. With the rise in AI adoption, associated risks have been identified, including privacy risks to the people whose data was used to train models. Assessing the privacy risks of machine learning models is crucial to enabling knowledgeable decisions on whether to use, deploy, or share a model. A common approach to privacy risk assessment is to run one or more known attacks against the model and measure their success rate. We present a novel framework for running membership inference attacks against classification models. Our framework takes advantage of the ensemble method, generating many specialized attack models for different subsets of the data. We show that this approach achieves higher accuracy than either a single attack model or an attack model per class label, both on classical and language classification tasks.
[ "Shlomit Shachor", "Natalia Razinkov", "Abigail Goldsteen" ]
2023-10-11 06:09:48
http://arxiv.org/abs/2310.07219v1
http://arxiv.org/pdf/2310.07219v1
2310.07219v1
Enhancing Neural Architecture Search with Multiple Hardware Constraints for Deep Learning Model Deployment on Tiny IoT Devices
The rapid proliferation of computing domains relying on Internet of Things (IoT) devices has created a pressing need for efficient and accurate deep-learning (DL) models that can run on low-power devices. However, traditional DL models tend to be too complex and computationally intensive for typical IoT end-nodes. To address this challenge, Neural Architecture Search (NAS) has emerged as a popular design automation technique for co-optimizing the accuracy and complexity of deep neural networks. Nevertheless, existing NAS techniques require many iterations to produce a network that adheres to specific hardware constraints, such as the maximum memory available on the hardware or the maximum latency allowed by the target application. In this work, we propose a novel approach to incorporate multiple constraints into so-called Differentiable NAS optimization methods, which allows the generation, in a single shot, of a model that respects user-defined constraints on both memory and latency in a time comparable to a single standard training. The proposed approach is evaluated on five IoT-relevant benchmarks, including the MLPerf Tiny suite and Tiny ImageNet, demonstrating that, with a single search, it is possible to reduce memory and latency by 87.4% and 54.2%, respectively (as defined by our targets), while ensuring non-inferior accuracy on state-of-the-art hand-tuned deep neural networks for TinyML.
[ "Alessio Burrello", "Matteo Risso", "Beatrice Alessandra Motetti", "Enrico Macii", "Luca Benini", "Daniele Jahier Pagliari" ]
2023-10-11 06:09:14
http://arxiv.org/abs/2310.07217v1
http://arxiv.org/pdf/2310.07217v1
2310.07217v1
Generative Modeling on Manifolds Through Mixture of Riemannian Diffusion Processes
Learning the distribution of data on Riemannian manifolds is crucial for modeling data from non-Euclidean space, which is required by many applications from diverse scientific fields. Yet, existing generative models on manifolds suffer from expensive divergence computation or rely on approximations of heat kernel. These limitations restrict their applicability to simple geometries and hinder scalability to high dimensions. In this work, we introduce the Riemannian Diffusion Mixture, a principled framework for building a generative process on manifolds as a mixture of endpoint-conditioned diffusion processes instead of relying on the denoising approach of previous diffusion models, for which the generative process is characterized by its drift guiding toward the most probable endpoint with respect to the geometry of the manifold. We further propose a simple yet efficient training objective for learning the mixture process, that is readily applicable to general manifolds. Our method outperforms previous generative models on various manifolds while scaling to high dimensions and requires a dramatically reduced number of in-training simulation steps for general manifolds.
[ "Jaehyeong Jo", "Sung Ju Hwang" ]
2023-10-11 06:04:40
http://arxiv.org/abs/2310.07216v1
http://arxiv.org/pdf/2310.07216v1
2310.07216v1
Bridging the Gap between Newton-Raphson Method and Regularized Policy Iteration
Regularization is one of the most important techniques in reinforcement learning algorithms. The well-known soft actor-critic algorithm is a special case of regularized policy iteration where the regularizer is chosen as Shannon entropy. Despite some empirical success of regularized policy iteration, its theoretical underpinnings remain unclear. This paper proves that regularized policy iteration is strictly equivalent to the standard Newton-Raphson method in the condition of smoothing out Bellman equation with strongly convex functions. This equivalence lays the foundation of a unified analysis for both global and local convergence behaviors of regularized policy iteration. We prove that regularized policy iteration has global linear convergence with the rate being $\gamma$ (discount factor). Furthermore, this algorithm converges quadratically once it enters a local region around the optimal value. We also show that a modified version of regularized policy iteration, i.e., with finite-step policy evaluation, is equivalent to inexact Newton method where the Newton iteration formula is solved with truncated iterations. We prove that the associated algorithm achieves an asymptotic linear convergence rate of $\gamma^M$ in which $M$ denotes the number of steps carried out in policy evaluation. Our results take a solid step towards a better understanding of the convergence properties of regularized policy iteration algorithms.
[ "Zeyang Li", "Chuxiong Hu", "Yunan Wang", "Guojian Zhan", "Jie Li", "Shengbo Eben Li" ]
2023-10-11 05:55:20
http://arxiv.org/abs/2310.07211v1
http://arxiv.org/pdf/2310.07211v1
2310.07211v1
Robust Safe Reinforcement Learning under Adversarial Disturbances
Safety is a primary concern when applying reinforcement learning to real-world control tasks, especially in the presence of external disturbances. However, existing safe reinforcement learning algorithms rarely account for external disturbances, limiting their applicability and robustness in practice. To address this challenge, this paper proposes a robust safe reinforcement learning framework that tackles worst-case disturbances. First, this paper presents a policy iteration scheme to solve for the robust invariant set, i.e., a subset of the safe set, where persistent safety is only possible for states within. The key idea is to establish a two-player zero-sum game by leveraging the safety value function in Hamilton-Jacobi reachability analysis, in which the protagonist (i.e., control inputs) aims to maintain safety and the adversary (i.e., external disturbances) tries to break down safety. This paper proves that the proposed policy iteration algorithm converges monotonically to the maximal robust invariant set. Second, this paper integrates the proposed policy iteration scheme into a constrained reinforcement learning algorithm that simultaneously synthesizes the robust invariant set and uses it for constrained policy optimization. This algorithm tackles both optimality and safety, i.e., learning a policy that attains high rewards while maintaining safety under worst-case disturbances. Experiments on classic control tasks show that the proposed method achieves zero constraint violation with learned worst-case adversarial disturbances, while other baseline algorithms violate the safety constraints substantially. Our proposed method also attains comparable performance as the baselines even in the absence of the adversary.
[ "Zeyang Li", "Chuxiong Hu", "Shengbo Eben Li", "Jia Cheng", "Yunan Wang" ]
2023-10-11 05:34:46
http://arxiv.org/abs/2310.07207v1
http://arxiv.org/pdf/2310.07207v1
2310.07207v1
State of the Art on Diffusion Models for Visual Computing
The field of visual computing is rapidly advancing due to the emergence of generative artificial intelligence (AI), which unlocks unprecedented capabilities for the generation, editing, and reconstruction of images, videos, and 3D scenes. In these domains, diffusion models are the generative AI architecture of choice. Within the last year alone, the literature on diffusion-based tools and applications has seen exponential growth and relevant papers are published across the computer graphics, computer vision, and AI communities with new works appearing daily on arXiv. This rapid growth of the field makes it difficult to keep up with all recent developments. The goal of this state-of-the-art report (STAR) is to introduce the basic mathematical concepts of diffusion models, implementation details and design choices of the popular Stable Diffusion model, as well as overview important aspects of these generative AI tools, including personalization, conditioning, inversion, among others. Moreover, we give a comprehensive overview of the rapidly growing literature on diffusion-based generation and editing, categorized by the type of generated medium, including 2D images, videos, 3D objects, locomotion, and 4D scenes. Finally, we discuss available datasets, metrics, open challenges, and social implications. This STAR provides an intuitive starting point to explore this exciting topic for researchers, artists, and practitioners alike.
[ "Ryan Po", "Wang Yifan", "Vladislav Golyanik", "Kfir Aberman", "Jonathan T. Barron", "Amit H. Bermano", "Eric Ryan Chan", "Tali Dekel", "Aleksander Holynski", "Angjoo Kanazawa", "C. Karen Liu", "Lingjie Liu", "Ben Mildenhall", "Matthias Nießner", "Björn Ommer", "Christian Theobalt", "Peter Wonka", "Gordon Wetzstein" ]
2023-10-11 05:32:29
http://arxiv.org/abs/2310.07204v1
http://arxiv.org/pdf/2310.07204v1
2310.07204v1
Boosting Learning for LDPC Codes to Improve the Error-Floor Performance
Low-density parity-check (LDPC) codes have been successfully commercialized in communication systems due to their strong error correction ability and simple decoding process. However, the error-floor phenomenon of LDPC codes, in which the error rate stops decreasing rapidly at a certain level, poses challenges in achieving extremely low error rates and the application of LDPC codes in scenarios demanding ultra high reliability. In this work, we propose training methods to optimize neural min-sum (NMS) decoders that are robust to the error-floor. Firstly, by leveraging the boosting learning technique of ensemble networks, we divide the decoding network into two networks and train the post network to be specialized for uncorrected codewords that failed in the first network. Secondly, to address the vanishing gradient issue in training, we introduce a block-wise training schedule that locally trains a block of weights while retraining the preceding block. Lastly, we show that assigning different weights to unsatisfied check nodes effectively lowers the error-floor with a minimal number of weights. By applying these training methods to standard LDPC codes, we achieve the best error-floor performance compared to other decoding methods. The proposed NMS decoder, optimized solely through novel training methods without additional modules, can be implemented into current LDPC decoders without incurring extra hardware costs. The source code is available at https://github.com/ghy1228/LDPC_Error_Floor.
[ "Hee-Youl Kwak", "Dae-Young Yun", "Yongjune Kim", "Sang-Hyo Kim", "Jong-Seon No" ]
2023-10-11 05:05:40
http://arxiv.org/abs/2310.07194v1
http://arxiv.org/pdf/2310.07194v1
2310.07194v1
Neural networks: deep, shallow, or in between?
We give estimates from below for the error of approximation of a compact subset from a Banach space by the outputs of feed-forward neural networks with width W, depth l and Lipschitz activation functions. We show that, modulo logarithmic factors, rates better that entropy numbers' rates are possibly attainable only for neural networks for which the depth l goes to infinity, and that there is no gain if we fix the depth and let the width W go to infinity.
[ "Guergana Petrova", "Przemyslaw Wojtaszczyk" ]
2023-10-11 04:50:28
http://arxiv.org/abs/2310.07190v1
http://arxiv.org/pdf/2310.07190v1
2310.07190v1
Kernel Cox partially linear regression: building predictive models for cancer patients' survival
Wide heterogeneity exists in cancer patients' survival, ranging from a few months to several decades. To accurately predict clinical outcomes, it is vital to build an accurate predictive model that relates patients' molecular profiles with patients' survival. With complex relationships between survival and high-dimensional molecular predictors, it is challenging to conduct non-parametric modeling and irrelevant predictors removing simultaneously. In this paper, we build a kernel Cox proportional hazards semi-parametric model and propose a novel regularized garrotized kernel machine (RegGKM) method to fit the model. We use the kernel machine method to describe the complex relationship between survival and predictors, while automatically removing irrelevant parametric and non-parametric predictors through a LASSO penalty. An efficient high-dimensional algorithm is developed for the proposed method. Comparison with other competing methods in simulation shows that the proposed method always has better predictive accuracy. We apply this method to analyze a multiple myeloma dataset and predict patients' death burden based on their gene expressions. Our results can help classify patients into groups with different death risks, facilitating treatment for better clinical outcomes.
[ "Yaohua Rong", "Sihai Dave Zhao", "Xia Zheng", "Yi Li" ]
2023-10-11 04:27:54
http://arxiv.org/abs/2310.07187v1
http://arxiv.org/pdf/2310.07187v1
2310.07187v1
NeuroInspect: Interpretable Neuron-based Debugging Framework through Class-conditional Visualizations
Despite deep learning (DL) has achieved remarkable progress in various domains, the DL models are still prone to making mistakes. This issue necessitates effective debugging tools for DL practitioners to interpret the decision-making process within the networks. However, existing debugging methods often demand extra data or adjustments to the decision process, limiting their applicability. To tackle this problem, we present NeuroInspect, an interpretable neuron-based debugging framework with three key stages: counterfactual explanations, feature visualizations, and false correlation mitigation. Our debugging framework first pinpoints neurons responsible for mistakes in the network and then visualizes features embedded in the neurons to be human-interpretable. To provide these explanations, we introduce CLIP-Illusion, a novel feature visualization method that generates images representing features conditioned on classes to examine the connection between neurons and the decision layer. We alleviate convoluted explanations of the conventional visualization approach by employing class information, thereby isolating mixed properties. This process offers more human-interpretable explanations for model errors without altering the trained network or requiring additional data. Furthermore, our framework mitigates false correlations learned from a dataset under a stochastic perspective, modifying decisions for the neurons considered as the main causes. We validate the effectiveness of our framework by addressing false correlations and improving inferences for classes with the worst performance in real-world settings. Moreover, we demonstrate that NeuroInspect helps debug the mistakes of DL models through evaluation for human understanding. The code is openly available at https://github.com/yeongjoonJu/NeuroInspect.
[ "Yeong-Joon Ju", "Ji-Hoon Park", "Seong-Whan Lee" ]
2023-10-11 04:20:32
http://arxiv.org/abs/2310.07184v2
http://arxiv.org/pdf/2310.07184v2
2310.07184v2
SAM-OCTA: Prompting Segment-Anything for OCTA Image Segmentation
In the analysis of optical coherence tomography angiography (OCTA) images, the operation of segmenting specific targets is necessary. Existing methods typically train on supervised datasets with limited samples (approximately a few hundred), which can lead to overfitting. To address this, the low-rank adaptation technique is adopted for foundation model fine-tuning and proposed corresponding prompt point generation strategies to process various segmentation tasks on OCTA datasets. This method is named SAM-OCTA and has been experimented on the publicly available OCTA-500 and ROSE datasets. This method achieves or approaches state-of-the-art segmentation performance metrics. The effect and applicability of prompt points are discussed in detail for the retinal vessel, foveal avascular zone, capillary, artery, and vein segmentation tasks. Furthermore, SAM-OCTA accomplishes local vessel segmentation and effective artery-vein segmentation, which was not well-solved in previous works. The code is available at https://github.com/ShellRedia/SAM-OCTA.
[ "Xinrun Chen", "Chengliang Wang", "Haojian Ning", "Shiying Li" ]
2023-10-11 04:14:59
http://arxiv.org/abs/2310.07183v1
http://arxiv.org/pdf/2310.07183v1
2310.07183v1
Online Speculative Decoding
Speculative decoding is a pivotal technique to accelerate the inference of large language models (LLMs) by employing a smaller draft model to predict the target model's outputs. However, its efficacy can be limited due to the low predictive accuracy of the draft model, particularly when faced with diverse text inputs and a significant capability gap between the draft and target models. We introduce online speculative decoding (OSD) to address this challenge. The main idea is to continually update (multiple) draft model(s) on observed user query data using the abundant excess computational power in an LLM serving cluster. Given that LLM inference is memory-bounded, the surplus computational power in a typical LLM serving cluster can be repurposed for online retraining of draft models, thereby making the training cost-neutral. Since the query distribution of an LLM service is relatively simple, retraining on query distribution enables the draft model to more accurately predict the target model's outputs, particularly on data originating from query distributions. As the draft model evolves online, it aligns with the query distribution in real time, mitigating distribution shifts. We develop a prototype of online speculative decoding based on online knowledge distillation and evaluate it using both synthetic and real query data on several popular LLMs. The results show a substantial increase in the token acceptance rate by 0.1 to 0.65, which translates into 1.22x to 3.06x latency reduction.
[ "Xiaoxuan Liu", "Lanxiang Hu", "Peter Bailis", "Ion Stoica", "Zhijie Deng", "Alvin Cheung", "Hao Zhang" ]
2023-10-11 04:03:42
http://arxiv.org/abs/2310.07177v2
http://arxiv.org/pdf/2310.07177v2
2310.07177v2
Generalized Neural Sorting Networks with Error-Free Differentiable Swap Functions
Sorting is a fundamental operation of all computer systems, having been a long-standing significant research topic. Beyond the problem formulation of traditional sorting algorithms, we consider sorting problems for more abstract yet expressive inputs, e.g., multi-digit images and image fragments, through a neural sorting network. To learn a mapping from a high-dimensional input to an ordinal variable, the differentiability of sorting networks needs to be guaranteed. In this paper we define a softening error by a differentiable swap function, and develop an error-free swap function that holds non-decreasing and differentiability conditions. Furthermore, a permutation-equivariant Transformer network with multi-head attention is adopted to capture dependency between given inputs and also leverage its model capacity with self-attention. Experiments on diverse sorting benchmarks show that our methods perform better than or comparable to baseline methods.
[ "Jungtaek Kim", "Jeongbeen Yoon", "Minsu Cho" ]
2023-10-11 03:47:34
http://arxiv.org/abs/2310.07174v1
http://arxiv.org/pdf/2310.07174v1
2310.07174v1
Federated Generalization via Information-Theoretic Distribution Diversification
Federated Learning (FL) has surged in prominence due to its capability of collaborative model training without direct data sharing. However, the vast disparity in local data distributions among clients, often termed the non-Independent Identically Distributed (non-IID) challenge, poses a significant hurdle to FL's generalization efficacy. The scenario becomes even more complex when not all clients participate in the training process, a common occurrence due to unstable network connections or limited computational capacities. This can greatly complicate the assessment of the trained models' generalization abilities. While a plethora of recent studies has centered on the generalization gap pertaining to unseen data from participating clients with diverse distributions, the divergence between the training distributions of participating clients and the testing distributions of non-participating ones has been largely overlooked. In response, our paper unveils an information-theoretic generalization framework for FL. Specifically, it quantifies generalization errors by evaluating the information entropy of local distributions and discerning discrepancies across these distributions. Inspired by our deduced generalization bounds, we introduce a weighted aggregation approach and a duo of client selection strategies. These innovations aim to bolster FL's generalization prowess by encompassing a more varied set of client data distributions. Our extensive empirical evaluations reaffirm the potency of our proposed methods, aligning seamlessly with our theoretical construct.
[ "Zheshun Wu", "Zenglin Xu", "Dun Zeng", "Qifan Wang" ]
2023-10-11 03:39:56
http://arxiv.org/abs/2310.07171v3
http://arxiv.org/pdf/2310.07171v3
2310.07171v3
Anchor-based Multi-view Subspace Clustering with Hierarchical Feature Descent
Multi-view clustering has attracted growing attention owing to its capabilities of aggregating information from various sources and its promising horizons in public affairs. Up till now, many advanced approaches have been proposed in recent literature. However, there are several ongoing difficulties to be tackled. One common dilemma occurs while attempting to align the features of different views. We dig out as well as deploy the dependency amongst views through hierarchical feature descent, which leads to a common latent space( STAGE 1). This latent space, for the first time of its kind, is regarded as a 'resemblance space', as it reveals certain correlations and dependencies of different views. To be exact, the one-hot encoding of a category can also be referred to as a resemblance space in its terminal phase. Moreover, due to the intrinsic fact that most of the existing multi-view clustering algorithms stem from k-means clustering and spectral clustering, this results in cubic time complexity w.r.t. the number of the objects. However, we propose Anchor-based Multi-view Subspace Clustering with Hierarchical Feature Descent(MVSC-HFD) to further reduce the computing complexity to linear time cost through a unified sampling strategy in resemblance space( STAGE 2), followed by subspace clustering to learn the representation collectively( STAGE 3). Extensive experimental results on public benchmark datasets demonstrate that our proposed model consistently outperforms the state-of-the-art techniques.
[ "Qiyuan Ou", "Siwei Wang", "Pei Zhang", "Sihang Zhou", "En Zhu" ]
2023-10-11 03:29:13
http://arxiv.org/abs/2310.07166v1
http://arxiv.org/pdf/2310.07166v1
2310.07166v1
LLark: A Multimodal Foundation Model for Music
Music has a unique and complex structure which is challenging for both expert humans and existing AI systems to understand, and presents unique challenges relative to other forms of audio. We present LLark, an instruction-tuned multimodal model for music understanding. We detail our process for dataset creation, which involves augmenting the annotations of diverse open-source music datasets and converting them to a unified instruction-tuning format. We propose a multimodal architecture for LLark, integrating a pretrained generative model for music with a pretrained language model. In evaluations on three types of tasks (music understanding, captioning, and reasoning), we show that our model matches or outperforms existing baselines in zero-shot generalization for music understanding, and that humans show a high degree of agreement with the model's responses in captioning and reasoning tasks. LLark is trained entirely from open-source music data and models, and we make our training code available along with the release of this paper. Additional results and audio examples are at https://bit.ly/llark, and our source code is available at https://github.com/spotify-research/llark .
[ "Josh Gardner", "Simon Durand", "Daniel Stoller", "Rachel M. Bittner" ]
2023-10-11 03:12:47
http://arxiv.org/abs/2310.07160v1
http://arxiv.org/pdf/2310.07160v1
2310.07160v1
No Privacy Left Outside: On the (In-)Security of TEE-Shielded DNN Partition for On-Device ML
On-device ML introduces new security challenges: DNN models become white-box accessible to device users. Based on white-box information, adversaries can conduct effective model stealing (MS) and membership inference attack (MIA). Using Trusted Execution Environments (TEEs) to shield on-device DNN models aims to downgrade (easy) white-box attacks to (harder) black-box attacks. However, one major shortcoming is the sharply increased latency (up to 50X). To accelerate TEE-shield DNN computation with GPUs, researchers proposed several model partition techniques. These solutions, referred to as TEE-Shielded DNN Partition (TSDP), partition a DNN model into two parts, offloading the privacy-insensitive part to the GPU while shielding the privacy-sensitive part within the TEE. This paper benchmarks existing TSDP solutions using both MS and MIA across a variety of DNN models, datasets, and metrics. We show important findings that existing TSDP solutions are vulnerable to privacy-stealing attacks and are not as safe as commonly believed. We also unveil the inherent difficulty in deciding optimal DNN partition configurations (i.e., the highest security with minimal utility cost) for present TSDP solutions. The experiments show that such ``sweet spot'' configurations vary across datasets and models. Based on lessons harvested from the experiments, we present TEESlice, a novel TSDP method that defends against MS and MIA during DNN inference. TEESlice follows a partition-before-training strategy, which allows for accurate separation between privacy-related weights from public weights. TEESlice delivers the same security protection as shielding the entire DNN model inside TEE (the ``upper-bound'' security guarantees) with over 10X less overhead (in both experimental and real-world environments) than prior TSDP solutions and no accuracy loss.
[ "Ziqi Zhang", "Chen Gong", "Yifeng Cai", "Yuanyuan Yuan", "Bingyan Liu", "Ding Li", "Yao Guo", "Xiangqun Chen" ]
2023-10-11 02:54:52
http://arxiv.org/abs/2310.07152v1
http://arxiv.org/pdf/2310.07152v1
2310.07152v1
QFT: Quantized Full-parameter Tuning of LLMs with Affordable Resources
Large Language Models (LLMs) have showcased remarkable impacts across a wide spectrum of natural language processing tasks. Fine-tuning these pre-trained models on downstream datasets provides further significant performance gains, but this process has been challenging due to its extraordinary resource requirements. To this end, existing efforts focus on parameter-efficient fine-tuning, which, unfortunately, fail to capitalize on the powerful potential of full-parameter fine-tuning. In this work, we propose QFT, a novel Quantized Full-parameter Tuning framework for LLMs that enables memory-efficient fine-tuning without harming performance. Our framework incorporates two novel ideas: (i) we adopt the efficient Lion optimizer, which only keeps track of the momentum and has consistent update magnitudes for each parameter, an inherent advantage for robust quantization; and (ii) we quantize all model states and store them as integer values, and present a gradient flow and parameter update scheme for the quantized weights. As a result, QFT reduces the model state memory to 21% of the standard solution while achieving comparable performance, e.g., tuning a LLaMA-7B model requires only <30GB of memory, satisfied by a single A6000 GPU.
[ "Zhikai Li", "Xiaoxuan Liu", "Banghua Zhu", "Zhen Dong", "Qingyi Gu", "Kurt Keutzer" ]
2023-10-11 02:47:40
http://arxiv.org/abs/2310.07147v1
http://arxiv.org/pdf/2310.07147v1
2310.07147v1
Imitation Learning from Purified Demonstration
Imitation learning has emerged as a promising approach for addressing sequential decision-making problems, with the assumption that expert demonstrations are optimal. However, in real-world scenarios, expert demonstrations are often imperfect, leading to challenges in effectively applying imitation learning. While existing research has focused on optimizing with imperfect demonstrations, the training typically requires a certain proportion of optimal demonstrations to guarantee performance. To tackle these problems, we propose to purify the potential perturbations in imperfect demonstrations and subsequently conduct imitation learning from purified demonstrations. Motivated by the success of diffusion models, we introduce a two-step purification via the diffusion process. In the first step, we apply a forward diffusion process to effectively smooth out the potential perturbations in imperfect demonstrations by introducing additional noise. Subsequently, a reverse generative process is utilized to recover the optimal expert demonstrations from the diffused ones. We provide theoretical evidence supporting our approach, demonstrating that total variance distance between the purified and optimal demonstration distributions can be upper-bounded. The evaluation results on MuJoCo demonstrate the effectiveness of our method from different aspects.
[ "Yunke Wang", "Minjing Dong", "Bo Du", "Chang Xu" ]
2023-10-11 02:36:52
http://arxiv.org/abs/2310.07143v1
http://arxiv.org/pdf/2310.07143v1
2310.07143v1
AE-smnsMLC: Multi-Label Classification with Semantic Matching and Negative Label Sampling for Product Attribute Value Extraction
Product attribute value extraction plays an important role for many real-world applications in e-Commerce such as product search and recommendation. Previous methods treat it as a sequence labeling task that needs more annotation for position of values in the product text. This limits their application to real-world scenario in which only attribute values are weakly-annotated for each product without their position. Moreover, these methods only use product text (i.e., product title and description) and do not consider the semantic connection between the multiple attribute values of a given product and its text, which can help attribute value extraction. In this paper, we reformulate this task as a multi-label classification task that can be applied for real-world scenario in which only annotation of attribute values is available to train models (i.e., annotation of positional information of attribute values is not available). We propose a classification model with semantic matching and negative label sampling for attribute value extraction. Semantic matching aims to capture semantic interactions between attribute values of a given product and its text. Negative label sampling aims to enhance the model's ability of distinguishing similar values belonging to the same attribute. Experimental results on three subsets of a large real-world e-Commerce dataset demonstrate the effectiveness and superiority of our proposed model.
[ "Zhongfen Deng", "Wei-Te Chen", "Lei Chen", "Philip S. Yu" ]
2023-10-11 02:22:28
http://arxiv.org/abs/2310.07137v1
http://arxiv.org/pdf/2310.07137v1
2310.07137v1
Risk Assessment and Statistical Significance in the Age of Foundation Models
We propose a distributional framework for assessing socio-technical risks of foundation models with quantified statistical significance. Our approach hinges on a new statistical relative testing based on first and second order stochastic dominance of real random variables. We show that the second order statistics in this test are linked to mean-risk models commonly used in econometrics and mathematical finance to balance risk and utility when choosing between alternatives. Using this framework, we formally develop a risk-aware approach for foundation model selection given guardrails quantified by specified metrics. Inspired by portfolio optimization and selection theory in mathematical finance, we define a \emph{metrics portfolio} for each model as a means to aggregate a collection of metrics, and perform model selection based on the stochastic dominance of these portfolios. The statistical significance of our tests is backed theoretically by an asymptotic analysis via central limit theorems instantiated in practice via a bootstrap variance estimate. We use our framework to compare various large language models regarding risks related to drifting from instructions and outputting toxic content.
[ "Apoorva Nitsure", "Youssef Mroueh", "Mattia Rigotti", "Kristjan Greenewald", "Brian Belgodere", "Mikhail Yurochkin", "Jiri Navratil", "Igor Melnyk", "Jerret Ross" ]
2023-10-11 02:08:37
http://arxiv.org/abs/2310.07132v1
http://arxiv.org/pdf/2310.07132v1
2310.07132v1
Off-Policy Evaluation for Human Feedback
Off-policy evaluation (OPE) is important for closing the gap between offline training and evaluation of reinforcement learning (RL), by estimating performance and/or rank of target (evaluation) policies using offline trajectories only. It can improve the safety and efficiency of data collection and policy testing procedures in situations where online deployments are expensive, such as healthcare. However, existing OPE methods fall short in estimating human feedback (HF) signals, as HF may be conditioned over multiple underlying factors and is only sparsely available; as opposed to the agent-defined environmental rewards (used in policy optimization), which are usually determined over parametric functions or distributions. Consequently, the nature of HF signals makes extrapolating accurate OPE estimations to be challenging. To resolve this, we introduce an OPE for HF (OPEHF) framework that revives existing OPE methods in order to accurately evaluate the HF signals. Specifically, we develop an immediate human reward (IHR) reconstruction approach, regularized by environmental knowledge distilled in a latent space that captures the underlying dynamics of state transitions as well as issuing HF signals. Our approach has been tested over two real-world experiments, adaptive in-vivo neurostimulation and intelligent tutoring, as well as in a simulation environment (visual Q&A). Results show that our approach significantly improves the performance toward estimating HF signals accurately, compared to directly applying (variants of) existing OPE methods.
[ "Qitong Gao", "Ge Gao", "Juncheng Dong", "Vahid Tarokh", "Min Chi", "Miroslav Pajic" ]
2023-10-11 01:52:42
http://arxiv.org/abs/2310.07123v2
http://arxiv.org/pdf/2310.07123v2
2310.07123v2
The Temporal Structure of Language Processing in the Human Brain Corresponds to The Layered Hierarchy of Deep Language Models
Deep Language Models (DLMs) provide a novel computational paradigm for understanding the mechanisms of natural language processing in the human brain. Unlike traditional psycholinguistic models, DLMs use layered sequences of continuous numerical vectors to represent words and context, allowing a plethora of emerging applications such as human-like text generation. In this paper we show evidence that the layered hierarchy of DLMs may be used to model the temporal dynamics of language comprehension in the brain by demonstrating a strong correlation between DLM layer depth and the time at which layers are most predictive of the human brain. Our ability to temporally resolve individual layers benefits from our use of electrocorticography (ECoG) data, which has a much higher temporal resolution than noninvasive methods like fMRI. Using ECoG, we record neural activity from participants listening to a 30-minute narrative while also feeding the same narrative to a high-performing DLM (GPT2-XL). We then extract contextual embeddings from the different layers of the DLM and use linear encoding models to predict neural activity. We first focus on the Inferior Frontal Gyrus (IFG, or Broca's area) and then extend our model to track the increasing temporal receptive window along the linguistic processing hierarchy from auditory to syntactic and semantic areas. Our results reveal a connection between human language processing and DLMs, with the DLM's layer-by-layer accumulation of contextual information mirroring the timing of neural activity in high-order language areas.
[ "Ariel Goldstein", "Eric Ham", "Mariano Schain", "Samuel Nastase", "Zaid Zada", "Avigail Dabush", "Bobbi Aubrey", "Harshvardhan Gazula", "Amir Feder", "Werner K Doyle", "Sasha Devore", "Patricia Dugan", "Daniel Friedman", "Roi Reichart", "Michael Brenner", "Avinatan Hassidim", "Orrin Devinsky", "Adeen Flinker", "Omer Levy", "Uri Hasson" ]
2023-10-11 01:03:42
http://arxiv.org/abs/2310.07106v1
http://arxiv.org/pdf/2310.07106v1
2310.07106v1
Machine Learning Methods for Background Potential Estimation in 2DEGs
In the realm of quantum-effect devices and materials, two-dimensional electron gases (2DEGs) stand as fundamental structures that promise transformative technologies. However, the presence of impurities and defects in 2DEGs poses substantial challenges, impacting carrier mobility, conductivity, and quantum coherence time. To address this, we harness the power of scanning gate microscopy (SGM) and employ three distinct machine learning techniques to estimate the background potential of 2DEGs from SGM data: image-to-image translation using generative adversarial neural networks, cellular neural network, and evolutionary search. Our findings, despite data constraints, highlight the effectiveness of an evolutionary search algorithm in this context, offering a novel approach for defect analysis. This work not only advances our understanding of 2DEGs but also underscores the potential of machine learning in probing quantum materials, with implications for quantum computing and nanoelectronics.
[ "Carlo da Cunha", "Nobuyuki Aoki", "David Ferry", "Kevin Vora", "Yu Zhang" ]
2023-10-11 00:03:07
http://arxiv.org/abs/2310.07089v1
http://arxiv.org/pdf/2310.07089v1
2310.07089v1
Investigating the Adversarial Robustness of Density Estimation Using the Probability Flow ODE
Beyond their impressive sampling capabilities, score-based diffusion models offer a powerful analysis tool in the form of unbiased density estimation of a query sample under the training data distribution. In this work, we investigate the robustness of density estimation using the probability flow (PF) neural ordinary differential equation (ODE) model against gradient-based likelihood maximization attacks and the relation to sample complexity, where the compressed size of a sample is used as a measure of its complexity. We introduce and evaluate six gradient-based log-likelihood maximization attacks, including a novel reverse integration attack. Our experimental evaluations on CIFAR-10 show that density estimation using the PF ODE is robust against high-complexity, high-likelihood attacks, and that in some cases adversarial samples are semantically meaningful, as expected from a robust estimator.
[ "Marius Arvinte", "Cory Cornelius", "Jason Martin", "Nageen Himayat" ]
2023-10-10 23:58:53
http://arxiv.org/abs/2310.07084v1
http://arxiv.org/pdf/2310.07084v1
2310.07084v1
Taking the human out of decomposition-based optimization via artificial intelligence: Part II. Learning to initialize
The repeated solution of large-scale optimization problems arises frequently in process systems engineering tasks. Decomposition-based solution methods have been widely used to reduce the corresponding computational time, yet their implementation has multiple steps that are difficult to configure. We propose a machine learning approach to learn the optimal initialization of such algorithms which minimizes the computational time. Active and supervised learning is used to learn a surrogate model that predicts the computational performance for a given initialization. We apply this approach to the initialization of Generalized Benders Decomposition for the solution of mixed integer model predictive control problems. The surrogate models are used to find the optimal number of initial cuts that should be added in the master problem. The results show that the proposed approach can lead to a significant reduction in solution time, and active learning can reduce the data required for learning.
[ "Ilias Mitrai", "Prodromos Daoutidis" ]
2023-10-10 23:49:26
http://arxiv.org/abs/2310.07082v1
http://arxiv.org/pdf/2310.07082v1
2310.07082v1
Secure Decentralized Learning with Blockchain
Federated Learning (FL) is a well-known paradigm of distributed machine learning on mobile and IoT devices, which preserves data privacy and optimizes communication efficiency. To avoid the single point of failure problem in FL, decentralized federated learning (DFL) has been proposed to use peer-to-peer communication for model aggregation, which has been considered an attractive solution for machine learning tasks on distributed personal devices. However, this process is vulnerable to attackers who share false models and data. If there exists a group of malicious clients, they might harm the performance of the model by carrying out a poisoning attack. In addition, in DFL, clients often lack the incentives to contribute their computing powers to do model training. In this paper, we proposed Blockchain-based Decentralized Federated Learning (BDFL), which leverages a blockchain for decentralized model verification and auditing. BDFL includes an auditor committee for model verification, an incentive mechanism to encourage the participation of clients, a reputation model to evaluate the trustworthiness of clients, and a protocol suite for dynamic network updates. Evaluation results show that, with the reputation mechanism, BDFL achieves fast model convergence and high accuracy on real datasets even if there exist 30\% malicious clients in the system.
[ "Xiaoxue Zhang", "Yifan Hua", "Chen Qian" ]
2023-10-10 23:45:17
http://arxiv.org/abs/2310.07079v1
http://arxiv.org/pdf/2310.07079v1
2310.07079v1
Taking the human out of decomposition-based optimization via artificial intelligence: Part I. Learning when to decompose
In this paper, we propose a graph classification approach for automatically determining whether to use a monolithic or a decomposition-based solution method. In this approach, an optimization problem is represented as a graph that captures the structural and functional coupling among the variables and constraints of the problem via an appropriate set of features. Given this representation, a graph classifier is built to determine the best solution method for a given problem. The proposed approach is used to develop a classifier that determines whether a convex Mixed Integer Nonlinear Programming problem should be solved using branch and bound or the outer approximation algorithm. Finally, it is shown how the learned classifier can be incorporated into existing mixed integer optimization solvers.
[ "Ilias Mitrai", "Prodromos Daoutidis" ]
2023-10-10 23:31:06
http://arxiv.org/abs/2310.07068v1
http://arxiv.org/pdf/2310.07068v1
2310.07068v1
Acoustic Model Fusion for End-to-end Speech Recognition
Recent advances in deep learning and automatic speech recognition (ASR) have enabled the end-to-end (E2E) ASR system and boosted the accuracy to a new level. The E2E systems implicitly model all conventional ASR components, such as the acoustic model (AM) and the language model (LM), in a single network trained on audio-text pairs. Despite this simpler system architecture, fusing a separate LM, trained exclusively on text corpora, into the E2E system has proven to be beneficial. However, the application of LM fusion presents certain drawbacks, such as its inability to address the domain mismatch issue inherent to the internal AM. Drawing inspiration from the concept of LM fusion, we propose the integration of an external AM into the E2E system to better address the domain mismatch. By implementing this novel approach, we have achieved a significant reduction in the word error rate, with an impressive drop of up to 14.3% across varied test sets. We also discovered that this AM fusion approach is particularly beneficial in enhancing named entity recognition.
[ "Zhihong Lei", "Mingbin Xu", "Shiyi Han", "Leo Liu", "Zhen Huang", "Tim Ng", "Yuanyuan Zhang", "Ernest Pusateri", "Mirko Hannemann", "Yaqiao Deng", "Man-Hung Siu" ]
2023-10-10 23:00:17
http://arxiv.org/abs/2310.07062v1
http://arxiv.org/pdf/2310.07062v1
2310.07062v1
DKEC: Domain Knowledge Enhanced Multi-Label Classification for Electronic Health Records
Multi-label text classification (MLTC) tasks in the medical domain often face long-tail label distribution, where rare classes have fewer training samples than frequent classes. Although previous works have explored different model architectures and hierarchical label structures to find important features, most of them neglect to incorporate the domain knowledge from medical guidelines. In this paper, we present DKEC, Domain Knowledge Enhanced Classifier for medical diagnosis prediction with two innovations: (1) a label-wise attention mechanism that incorporates a heterogeneous graph and domain ontologies to capture the semantic relationships between medical entities, (2) a simple yet effective group-wise training method based on similarity of labels to increase samples of rare classes. We evaluate DKEC on two real-world medical datasets: the RAA dataset, a collection of 4,417 patient care reports from emergency medical services (EMS) incidents, and a subset of 53,898 reports from the MIMIC-III dataset. Experimental results show that our method outperforms the state-of-the-art, particularly for the few-shot (tail) classes. More importantly, we study the applicability of DKEC to different language models and show that DKEC can help the smaller language models achieve comparable performance to large language models.
[ "Xueren Ge", "Ronald Dean Williams", "John A. Stankovic", "Homa Alemzadeh" ]
2023-10-10 22:53:15
http://arxiv.org/abs/2310.07059v1
http://arxiv.org/pdf/2310.07059v1
2310.07059v1
Spiral-Elliptical automated galaxy morphology classification from telescope images
The classification of galaxy morphologies is an important step in the investigation of theories of hierarchical structure formation. While human expert visual classification remains quite effective and accurate, it cannot keep up with the massive influx of data from emerging sky surveys. A variety of approaches have been proposed to classify large numbers of galaxies; these approaches include crowdsourced visual classification, and automated and computational methods, such as machine learning methods based on designed morphology statistics and deep learning. In this work, we develop two novel galaxy morphology statistics, descent average and descent variance, which can be efficiently extracted from telescope galaxy images. We further propose simplified versions of the existing image statistics concentration, asymmetry, and clumpiness, which have been widely used in the literature of galaxy morphologies. We utilize the galaxy image data from the Sloan Digital Sky Survey to demonstrate the effective performance of our proposed image statistics at accurately detecting spiral and elliptical galaxies when used as features of a random forest classifier.
[ "Matthew J. Baumstark", "Giuseppe Vinci" ]
2023-10-10 22:36:52
http://arxiv.org/abs/2310.07740v1
http://arxiv.org/pdf/2310.07740v1
2310.07740v1
FedMFS: Federated Multimodal Fusion Learning with Selective Modality Communication
Federated learning (FL) is a distributed machine learning (ML) paradigm that enables clients to collaborate without accessing, infringing upon, or leaking original user data by sharing only model parameters. In the Internet of Things (IoT), edge devices are increasingly leveraging multimodal data compositions and fusion paradigms to enhance model performance. However, in FL applications, two main challenges remain open: (i) addressing the issues caused by heterogeneous clients lacking specific modalities and (ii) devising an optimal modality upload strategy to minimize communication overhead while maximizing learning performance. In this paper, we propose Federated Multimodal Fusion learning with Selective modality communication (FedMFS), a new multimodal fusion FL methodology that can tackle the above mentioned challenges. The key idea is to utilize Shapley values to quantify each modality's contribution and modality model size to gauge communication overhead, so that each client can selectively upload the modality models to the server for aggregation. This enables FedMFS to flexibly balance performance against communication costs, depending on resource constraints and applications. Experiments on real-world multimodal datasets demonstrate the effectiveness of FedMFS, achieving comparable accuracy while reducing communication overhead by one twentieth compared to baselines.
[ "Liangqi Yuan", "Dong-Jun Han", "Vishnu Pandi Chellapandi", "Stanislaw H. Żak", "Christopher G. Brinton" ]
2023-10-10 22:23:27
http://arxiv.org/abs/2310.07048v1
http://arxiv.org/pdf/2310.07048v1
2310.07048v1
A predict-and-optimize approach to profit-driven churn prevention
In this paper, we introduce a novel predict-and-optimize method for profit-driven churn prevention. We frame the task of targeting customers for a retention campaign as a regret minimization problem. The main objective is to leverage individual customer lifetime values (CLVs) to ensure that only the most valuable customers are targeted. In contrast, many profit-driven strategies focus on churn probabilities while considering average CLVs. This often results in significant information loss due to data aggregation. Our proposed model aligns with the guidelines of Predict-and-Optimize (PnO) frameworks and can be efficiently solved using stochastic gradient descent methods. Results from 12 churn prediction datasets underscore the effectiveness of our approach, which achieves the best average performance compared to other well-established strategies in terms of average profit.
[ "Nuria Gómez-Vargas", "Sebastián Maldonado", "Carla Vairetti" ]
2023-10-10 22:21:16
http://arxiv.org/abs/2310.07047v1
http://arxiv.org/pdf/2310.07047v1
2310.07047v1
Computational Pathology at Health System Scale -- Self-Supervised Foundation Models from Three Billion Images
Recent breakthroughs in self-supervised learning have enabled the use of large unlabeled datasets to train visual foundation models that can generalize to a variety of downstream tasks. While this training paradigm is well suited for the medical domain where annotations are scarce, large-scale pre-training in the medical domain, and in particular pathology, has not been extensively studied. Previous work in self-supervised learning in pathology has leveraged smaller datasets for both pre-training and evaluating downstream performance. The aim of this project is to train the largest academic foundation model and benchmark the most prominent self-supervised learning algorithms by pre-training and evaluating downstream performance on large clinical pathology datasets. We collected the largest pathology dataset to date, consisting of over 3 billion images from over 423 thousand microscopy slides. We compared pre-training of visual transformer models using the masked autoencoder (MAE) and DINO algorithms. We evaluated performance on six clinically relevant tasks from three anatomic sites and two institutions: breast cancer detection, inflammatory bowel disease detection, breast cancer estrogen receptor prediction, lung adenocarcinoma EGFR mutation prediction, and lung cancer immunotherapy response prediction. Our results demonstrate that pre-training on pathology data is beneficial for downstream performance compared to pre-training on natural images. Additionally, the DINO algorithm achieved better generalization performance across all tasks tested. The presented results signify a phase change in computational pathology research, paving the way into a new era of more performant models based on large-scale, parallel pre-training at the billion-image scale.
[ "Gabriele Campanella", "Ricky Kwan", "Eugene Fluder", "Jennifer Zeng", "Aryeh Stock", "Brandon Veremis", "Alexandros D. Polydorides", "Cyrus Hedvat", "Adam Schoenfeld", "Chad Vanderbilt", "Patricia Kovatch", "Carlos Cordon-Cardo", "Thomas J. Fuchs" ]
2023-10-10 21:40:19
http://arxiv.org/abs/2310.07033v1
http://arxiv.org/pdf/2310.07033v1
2310.07033v1
Neural Harmonium: An Interpretable Deep Structure for Nonlinear Dynamic System Identification with Application to Audio Processing
Improving the interpretability of deep neural networks has recently gained increased attention, especially when the power of deep learning is leveraged to solve problems in physics. Interpretability helps us understand a model's ability to generalize and reveal its limitations. In this paper, we introduce a causal interpretable deep structure for modeling dynamic systems. Our proposed model makes use of the harmonic analysis by modeling the system in a time-frequency domain while maintaining high temporal and spectral resolution. Moreover, the model is built in an order recursive manner which allows for fast, robust, and exact second order optimization without the need for an explicit Hessian calculation. To circumvent the resulting high dimensionality of the building blocks of our system, a neural network is designed to identify the frequency interdependencies. The proposed model is illustrated and validated on nonlinear system identification problems as required for audio signal processing tasks. Crowd-sourced experimentation contrasting the performance of the proposed approach to other state-of-the-art solutions on an acoustic echo cancellation scenario confirms the effectiveness of our method for real-life applications.
[ "Karim Helwani", "Erfan Soltanmohammadi", "Michael M. Goodwin" ]
2023-10-10 21:32:15
http://arxiv.org/abs/2310.07032v1
http://arxiv.org/pdf/2310.07032v1
2310.07032v1
Facial Forgery-based Deepfake Detection using Fine-Grained Features
Facial forgery by deepfakes has caused major security risks and raised severe societal concerns. As a countermeasure, a number of deepfake detection methods have been proposed. Most of them model deepfake detection as a binary classification problem using a backbone convolutional neural network (CNN) architecture pretrained for the task. These CNN-based methods have demonstrated very high efficacy in deepfake detection with the Area under the Curve (AUC) as high as $0.99$. However, the performance of these methods degrades significantly when evaluated across datasets and deepfake manipulation techniques. This draws our attention towards learning more subtle, local, and discriminative features for deepfake detection. In this paper, we formulate deepfake detection as a fine-grained classification problem and propose a new fine-grained solution to it. Specifically, our method is based on learning subtle and generalizable features by effectively suppressing background noise and learning discriminative features at various scales for deepfake detection. Through extensive experimental validation, we demonstrate the superiority of our method over the published research in cross-dataset and cross-manipulation generalization of deepfake detectors for the majority of the experimental scenarios.
[ "Aakash Varma Nadimpalli", "Ajita Rattani" ]
2023-10-10 21:30:05
http://arxiv.org/abs/2310.07028v1
http://arxiv.org/pdf/2310.07028v1
2310.07028v1
Utilizing Synthetic Data for Medical Vision-Language Pre-training: Bypassing the Need for Real Images
Medical Vision-Language Pre-training (VLP) learns representations jointly from medical images and paired radiology reports. It typically requires large-scale paired image-text datasets to achieve effective pre-training for both the image encoder and text encoder. The advent of text-guided generative models raises a compelling question: Can VLP be implemented solely with synthetic images generated from genuine radiology reports, thereby mitigating the need for extensively pairing and curating image-text datasets? In this work, we scrutinize this very question by examining the feasibility and effectiveness of employing synthetic images for medical VLP. We replace real medical images with their synthetic equivalents, generated from authentic medical reports. Utilizing three state-of-the-art VLP algorithms, we exclusively train on these synthetic samples. Our empirical evaluation across three subsequent tasks, namely image classification, semantic segmentation and object detection, reveals that the performance achieved through synthetic data is on par with or even exceeds that obtained with real images. As a pioneering contribution to this domain, we introduce a large-scale synthetic medical image dataset, paired with anonymized real radiology reports. This alleviates the need of sharing medical images, which are not easy to curate and share in practice. The code and the dataset will be made publicly available upon paper acceptance.
[ "Che Liu", "Anand Shah", "Wenjia Bai", "Rossella Arcucci" ]
2023-10-10 21:29:41
http://arxiv.org/abs/2310.07027v1
http://arxiv.org/pdf/2310.07027v1
2310.07027v1
Automatic Macro Mining from Interaction Traces at Scale
Macros are building block tasks of our everyday smartphone activity (e.g., "login", or "booking a flight"). Effectively extracting macros is important for understanding mobile interaction and enabling task automation. These macros are however difficult to extract at scale as they can be comprised of multiple steps yet hidden within programmatic components of the app. In this paper, we introduce a novel approach based on Large Language Models (LLMs) to automatically extract semantically meaningful macros from both random and user-curated mobile interaction traces. The macros produced by our approach are automatically tagged with natural language descriptions and are fully executable. To examine the quality of extraction, we conduct multiple studies, including user evaluation, comparative analysis against human-curated tasks, and automatic execution of these macros. These experiments and analyses show the effectiveness of our approach and the usefulness of extracted macros in various downstream applications.
[ "Forrest Huang", "Gang Li", "Tao Li", "Yang Li" ]
2023-10-10 21:23:47
http://arxiv.org/abs/2310.07023v1
http://arxiv.org/pdf/2310.07023v1
2310.07023v1
Neural Relational Inference with Fast Modular Meta-learning
\textit{Graph neural networks} (GNNs) are effective models for many dynamical systems consisting of entities and relations. Although most GNN applications assume a single type of entity and relation, many situations involve multiple types of interactions. \textit{Relational inference} is the problem of inferring these interactions and learning the dynamics from observational data. We frame relational inference as a \textit{modular meta-learning} problem, where neural modules are trained to be composed in different ways to solve many tasks. This meta-learning framework allows us to implicitly encode time invariance and infer relations in context of one another rather than independently, which increases inference capacity. Framing inference as the inner-loop optimization of meta-learning leads to a model-based approach that is more data-efficient and capable of estimating the state of entities that we do not observe directly, but whose existence can be inferred from their effect on observed entities. To address the large search space of graph neural network compositions, we meta-learn a \textit{proposal function} that speeds up the inner-loop simulated annealing search within the modular meta-learning algorithm, providing two orders of magnitude increase in the size of problems that can be addressed.
[ "Ferran Alet", "Erica Weng", "Tomás Lozano Pérez", "Leslie Pack Kaelbling" ]
2023-10-10 21:05:13
http://arxiv.org/abs/2310.07015v1
http://arxiv.org/pdf/2310.07015v1
2310.07015v1
Answer Candidate Type Selection: Text-to-Text Language Model for Closed Book Question Answering Meets Knowledge Graphs
Pre-trained Text-to-Text Language Models (LMs), such as T5 or BART yield promising results in the Knowledge Graph Question Answering (KGQA) task. However, the capacity of the models is limited and the quality decreases for questions with less popular entities. In this paper, we present a novel approach which works on top of the pre-trained Text-to-Text QA system to address this issue. Our simple yet effective method performs filtering and re-ranking of generated candidates based on their types derived from Wikidata "instance_of" property.
[ "Mikhail Salnikov", "Maria Lysyuk", "Pavel Braslavski", "Anton Razzhigaev", "Valentin Malykh", "Alexander Panchenko" ]
2023-10-10 20:49:43
http://arxiv.org/abs/2310.07008v1
http://arxiv.org/pdf/2310.07008v1
2310.07008v1
Sound-skwatter (Did You Mean: Sound-squatter?) AI-powered Generator for Phishing Prevention
Sound-squatting is a phishing attack that tricks users into malicious resources by exploiting similarities in the pronunciation of words. Proactive defense against sound-squatting candidates is complex, and existing solutions rely on manually curated lists of homophones. We here introduce Sound-skwatter, a multi-language AI-based system that generates sound-squatting candidates for proactive defense. Sound-skwatter relies on an innovative multi-modal combination of Transformers Networks and acoustic models to learn sound similarities. We show that Sound-skwatter can automatically list known homophones and thousands of high-quality candidates. In addition, it covers cross-language sound-squatting, i.e., when the reader and the listener speak different languages, supporting any combination of languages. We apply Sound-skwatter to network-centric phishing via squatted domain names. We find ~ 10% of the generated domains exist in the wild, the vast majority unknown to protection solutions. Next, we show attacks on the PyPI package manager, where ~ 17% of the popular packages have at least one existing candidate. We believe Sound-skwatter is a crucial asset to mitigate the sound-squatting phenomenon proactively on the Internet. To increase its impact, we publish an online demo and release our models and code as open source.
[ "Rodolfo Valentim", "Idilio Drago", "Marco Mellia", "Federico Cerutti" ]
2023-10-10 20:36:39
http://arxiv.org/abs/2310.07005v1
http://arxiv.org/pdf/2310.07005v1
2310.07005v1
CarDS-Plus ECG Platform: Development and Feasibility Evaluation of a Multiplatform Artificial Intelligence Toolkit for Portable and Wearable Device Electrocardiograms
In the rapidly evolving landscape of modern healthcare, the integration of wearable & portable technology provides a unique opportunity for personalized health monitoring in the community. Devices like the Apple Watch, FitBit, and AliveCor KardiaMobile have revolutionized the acquisition and processing of intricate health data streams. Amidst the variety of data collected by these gadgets, single-lead electrocardiogram (ECG) recordings have emerged as a crucial source of information for monitoring cardiovascular health. There has been significant advances in artificial intelligence capable of interpreting these 1-lead ECGs, facilitating clinical diagnosis as well as the detection of rare cardiac disorders. This design study describes the development of an innovative multiplatform system aimed at the rapid deployment of AI-based ECG solutions for clinical investigation & care delivery. The study examines design considerations, aligning them with specific applications, develops data flows to maximize efficiency for research & clinical use. This process encompasses the reception of single-lead ECGs from diverse wearable devices, channeling this data into a centralized data lake & facilitating real-time inference through AI models for ECG interpretation. An evaluation of the platform demonstrates a mean duration from acquisition to reporting of results of 33.0 to 35.7 seconds, after a standard 30 second acquisition. There were no substantial differences in acquisition to reporting across two commercially available devices (Apple Watch and KardiaMobile). These results demonstrate the succcessful translation of design principles into a fully integrated & efficient strategy for leveraging 1-lead ECGs across platforms & interpretation by AI-ECG algorithms. Such a platform is critical to translating AI discoveries for wearable and portable ECG devices to clinical impact through rapid deployment.
[ "Sumukh Vasisht Shankar", "Evangelos K Oikonomou", "Rohan Khera" ]
2023-10-10 20:33:48
http://arxiv.org/abs/2310.07000v1
http://arxiv.org/pdf/2310.07000v1
2310.07000v1
Violation of Expectation via Metacognitive Prompting Reduces Theory of Mind Prediction Error in Large Language Models
Recent research shows that Large Language Models (LLMs) exhibit a compelling level of proficiency in Theory of Mind (ToM) tasks. This ability to impute unobservable mental states to others is vital to human social cognition and may prove equally important in principal-agent relations between individual humans and Artificial Intelligences (AIs). In this paper, we explore how a mechanism studied in developmental psychology known as Violation of Expectation (VoE) can be implemented to reduce errors in LLM prediction about users by leveraging emergent ToM affordances. And we introduce a \textit{metacognitive prompting} framework to apply VoE in the context of an AI tutor. By storing and retrieving facts derived in cases where LLM expectation about the user was violated, we find that LLMs are able to learn about users in ways that echo theories of human learning. Finally, we discuss latent hazards and augmentative opportunities associated with modeling user psychology and propose ways to mitigate risk along with possible directions for future inquiry.
[ "Courtland Leer", "Vincent Trost", "Vineeth Voruganti" ]
2023-10-10 20:05:13
http://arxiv.org/abs/2310.06983v1
http://arxiv.org/pdf/2310.06983v1
2310.06983v1
Data Distillation Can Be Like Vodka: Distilling More Times For Better Quality
Dataset distillation aims to minimize the time and memory needed for training deep networks on large datasets, by creating a small set of synthetic images that has a similar generalization performance to that of the full dataset. However, current dataset distillation techniques fall short, showing a notable performance gap when compared to training on the original data. In this work, we are the first to argue that using just one synthetic subset for distillation will not yield optimal generalization performance. This is because the training dynamics of deep networks drastically change during the training. Hence, multiple synthetic subsets are required to capture the training dynamics at different phases of training. To address this issue, we propose Progressive Dataset Distillation (PDD). PDD synthesizes multiple small sets of synthetic images, each conditioned on the previous sets, and trains the model on the cumulative union of these subsets without requiring additional training time. Our extensive experiments show that PDD can effectively improve the performance of existing dataset distillation methods by up to 4.3%. In addition, our method for the first time enable generating considerably larger synthetic datasets.
[ "Xuxi Chen", "Yu Yang", "Zhangyang Wang", "Baharan Mirzasoleiman" ]
2023-10-10 20:04:44
http://arxiv.org/abs/2310.06982v1
http://arxiv.org/pdf/2310.06982v1
2310.06982v1
Federated Quantum Machine Learning with Differential Privacy
The preservation of privacy is a critical concern in the implementation of artificial intelligence on sensitive training data. There are several techniques to preserve data privacy but quantum computations are inherently more secure due to the no-cloning theorem, resulting in a most desirable computational platform on top of the potential quantum advantages. There have been prior works in protecting data privacy by Quantum Federated Learning (QFL) and Quantum Differential Privacy (QDP) studied independently. However, to the best of our knowledge, no prior work has addressed both QFL and QDP together yet. Here, we propose to combine these privacy-preserving methods and implement them on the quantum platform, so that we can achieve comprehensive protection against data leakage (QFL) and model inversion attacks (QDP). This implementation promises more efficient and secure artificial intelligence. In this paper, we present a successful implementation of these privacy-preservation methods by performing the binary classification of the Cats vs Dogs dataset. Using our quantum-classical machine learning model, we obtained a test accuracy of over 0.98, while maintaining epsilon values less than 1.3. We show that federated differentially private training is a viable privacy preservation method for quantum machine learning on Noisy Intermediate-Scale Quantum (NISQ) devices.
[ "Rod Rofougaran", "Shinjae Yoo", "Huan-Hsin Tseng", "Samuel Yen-Chi Chen" ]
2023-10-10 19:52:37
http://arxiv.org/abs/2310.06973v1
http://arxiv.org/pdf/2310.06973v1
2310.06973v1
Flood and Echo: Algorithmic Alignment of GNNs with Distributed Computing
Graph Neural Networks are a natural fit for learning algorithms. They can directly represent tasks through an abstract but versatile graph structure and handle inputs of different sizes. This opens up the possibility for scaling and extrapolation to larger graphs, one of the most important advantages of an algorithm. However, this raises two core questions i) How can we enable nodes to gather the required information in a given graph ($\textit{information exchange}$), even if is far away and ii) How can we design an execution framework which enables this information exchange for extrapolation to larger graph sizes ($\textit{algorithmic alignment for extrapolation}$). We propose a new execution framework that is inspired by the design principles of distributed algorithms: Flood and Echo Net. It propagates messages through the entire graph in a wave like activation pattern, which naturally generalizes to larger instances. Through its sparse but parallel activations it is provably more efficient in terms of message complexity. We study the proposed model and provide both empirical evidence and theoretical insights in terms of its expressiveness, efficiency, information exchange and ability to extrapolate.
[ "Joël Mathys", "Florian Grötschla", "Kalyan Varma Nadimpalli", "Roger Wattenhofer" ]
2023-10-10 19:47:58
http://arxiv.org/abs/2310.06970v2
http://arxiv.org/pdf/2310.06970v2
2310.06970v2