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Model Share AI: An Integrated Toolkit for Collaborative Machine Learning Model Development, Provenance Tracking, and Deployment in Python
Machine learning (ML) has the potential to revolutionize a wide range of research areas and industries, but many ML projects never progress past the proof-of-concept stage. To address this issue, we introduce Model Share AI (AIMS), an easy-to-use MLOps platform designed to streamline collaborative model development, model provenance tracking, and model deployment, as well as a host of other functions aiming to maximize the real-world impact of ML research. AIMS features collaborative project spaces and a standardized model evaluation process that ranks model submissions based on their performance on unseen evaluation data, enabling collaborative model development and crowd-sourcing. Model performance and various model metadata are automatically captured to facilitate provenance tracking and allow users to learn from and build on previous submissions. Additionally, AIMS allows users to deploy ML models built in Scikit-Learn, TensorFlow Keras, PyTorch, and ONNX into live REST APIs and automatically generated web apps with minimal code. The ability to deploy models with minimal effort and to make them accessible to non-technical end-users through web apps has the potential to make ML research more applicable to real-world challenges.
[ "Heinrich Peters", "Michael Parrott" ]
2023-09-27 15:24:39
http://arxiv.org/abs/2309.15719v1
http://arxiv.org/pdf/2309.15719v1
2309.15719v1
Timbre-Trap: A Low-Resource Framework for Instrument-Agnostic Music Transcription
In recent years, research on music transcription has focused mainly on architecture design and instrument-specific data acquisition. With the lack of availability of diverse datasets, progress is often limited to solo-instrument tasks such as piano transcription. Several works have explored multi-instrument transcription as a means to bolster the performance of models on low-resource tasks, but these methods face the same data availability issues. We propose Timbre-Trap, a novel framework which unifies music transcription and audio reconstruction by exploiting the strong separability between pitch and timbre. We train a single U-Net to simultaneously estimate pitch salience and reconstruct complex spectral coefficients, selecting between either output during the decoding stage via a simple switch mechanism. In this way, the model learns to produce coefficients corresponding to timbre-less audio, which can be interpreted as pitch salience. We demonstrate that the framework leads to performance comparable to state-of-the-art instrument-agnostic transcription methods, while only requiring a small amount of annotated data.
[ "Frank Cwitkowitz", "Kin Wai Cheuk", "Woosung Choi", "Marco A. Martínez-Ramírez", "Keisuke Toyama", "Wei-Hsiang Liao", "Yuki Mitsufuji" ]
2023-09-27 15:19:05
http://arxiv.org/abs/2309.15717v1
http://arxiv.org/pdf/2309.15717v1
2309.15717v1
Maximum Weight Entropy
This paper deals with uncertainty quantification and out-of-distribution detection in deep learning using Bayesian and ensemble methods. It proposes a practical solution to the lack of prediction diversity observed recently for standard approaches when used out-of-distribution (Ovadia et al., 2019; Liu et al., 2021). Considering that this issue is mainly related to a lack of weight diversity, we claim that standard methods sample in "over-restricted" regions of the weight space due to the use of "over-regularization" processes, such as weight decay and zero-mean centered Gaussian priors. We propose to solve the problem by adopting the maximum entropy principle for the weight distribution, with the underlying idea to maximize the weight diversity. Under this paradigm, the epistemic uncertainty is described by the weight distribution of maximal entropy that produces neural networks "consistent" with the training observations. Considering stochastic neural networks, a practical optimization is derived to build such a distribution, defined as a trade-off between the average empirical risk and the weight distribution entropy. We develop a novel weight parameterization for the stochastic model, based on the singular value decomposition of the neural network's hidden representations, which enables a large increase of the weight entropy for a small empirical risk penalization. We provide both theoretical and numerical results to assess the efficiency of the approach. In particular, the proposed algorithm appears in the top three best methods in all configurations of an extensive out-of-distribution detection benchmark including more than thirty competitors.
[ "Antoine de Mathelin", "François Deheeger", "Mathilde Mougeot", "Nicolas Vayatis" ]
2023-09-27 14:46:10
http://arxiv.org/abs/2309.15704v1
http://arxiv.org/pdf/2309.15704v1
2309.15704v1
HyPoradise: An Open Baseline for Generative Speech Recognition with Large Language Models
Advancements in deep neural networks have allowed automatic speech recognition (ASR) systems to attain human parity on several publicly available clean speech datasets. However, even state-of-the-art ASR systems experience performance degradation when confronted with adverse conditions, as a well-trained acoustic model is sensitive to variations in the speech domain, e.g., background noise. Intuitively, humans address this issue by relying on their linguistic knowledge: the meaning of ambiguous spoken terms is usually inferred from contextual cues thereby reducing the dependency on the auditory system. Inspired by this observation, we introduce the first open-source benchmark to utilize external large language models (LLMs) for ASR error correction, where N-best decoding hypotheses provide informative elements for true transcription prediction. This approach is a paradigm shift from the traditional language model rescoring strategy that can only select one candidate hypothesis as the output transcription. The proposed benchmark contains a novel dataset, HyPoradise (HP), encompassing more than 334,000 pairs of N-best hypotheses and corresponding accurate transcriptions across prevalent speech domains. Given this dataset, we examine three types of error correction techniques based on LLMs with varying amounts of labeled hypotheses-transcription pairs, which gains a significant word error rate (WER) reduction. Experimental evidence demonstrates the proposed technique achieves a breakthrough by surpassing the upper bound of traditional re-ranking based methods. More surprisingly, LLM with reasonable prompt and its generative capability can even correct those tokens that are missing in N-best list. We make our results publicly accessible for reproducible pipelines with released pre-trained models, thus providing a new evaluation paradigm for ASR error correction with LLMs.
[ "Chen Chen", "Yuchen Hu", "Chao-Han Huck Yang", "Sabato Macro Siniscalchi", "Pin-Yu Chen", "Eng Siong Chng" ]
2023-09-27 14:44:10
http://arxiv.org/abs/2309.15701v2
http://arxiv.org/pdf/2309.15701v2
2309.15701v2
Deep Model Fusion: A Survey
Deep model fusion/merging is an emerging technique that merges the parameters or predictions of multiple deep learning models into a single one. It combines the abilities of different models to make up for the biases and errors of a single model to achieve better performance. However, deep model fusion on large-scale deep learning models (e.g., LLMs and foundation models) faces several challenges, including high computational cost, high-dimensional parameter space, interference between different heterogeneous models, etc. Although model fusion has attracted widespread attention due to its potential to solve complex real-world tasks, there is still a lack of complete and detailed survey research on this technique. Accordingly, in order to understand the model fusion method better and promote its development, we present a comprehensive survey to summarize the recent progress. Specifically, we categorize existing deep model fusion methods as four-fold: (1) "Mode connectivity", which connects the solutions in weight space via a path of non-increasing loss, in order to obtain better initialization for model fusion; (2) "Alignment" matches units between neural networks to create better conditions for fusion; (3) "Weight average", a classical model fusion method, averages the weights of multiple models to obtain more accurate results closer to the optimal solution; (4) "Ensemble learning" combines the outputs of diverse models, which is a foundational technique for improving the accuracy and robustness of the final model. In addition, we analyze the challenges faced by deep model fusion and propose possible research directions for model fusion in the future. Our review is helpful in deeply understanding the correlation between different model fusion methods and practical application methods, which can enlighten the research in the field of deep model fusion.
[ "Weishi Li", "Yong Peng", "Miao Zhang", "Liang Ding", "Han Hu", "Li Shen" ]
2023-09-27 14:40:12
http://arxiv.org/abs/2309.15698v1
http://arxiv.org/pdf/2309.15698v1
2309.15698v1
A Unified View of Differentially Private Deep Generative Modeling
The availability of rich and vast data sources has greatly advanced machine learning applications in various domains. However, data with privacy concerns comes with stringent regulations that frequently prohibited data access and data sharing. Overcoming these obstacles in compliance with privacy considerations is key for technological progress in many real-world application scenarios that involve privacy sensitive data. Differentially private (DP) data publishing provides a compelling solution, where only a sanitized form of the data is publicly released, enabling privacy-preserving downstream analysis and reproducible research in sensitive domains. In recent years, various approaches have been proposed for achieving privacy-preserving high-dimensional data generation by private training on top of deep neural networks. In this paper, we present a novel unified view that systematizes these approaches. Our view provides a joint design space for systematically deriving methods that cater to different use cases. We then discuss the strengths, limitations, and inherent correlations between different approaches, aiming to shed light on crucial aspects and inspire future research. We conclude by presenting potential paths forward for the field of DP data generation, with the aim of steering the community toward making the next important steps in advancing privacy-preserving learning.
[ "Dingfan Chen", "Raouf Kerkouche", "Mario Fritz" ]
2023-09-27 14:38:16
http://arxiv.org/abs/2309.15696v1
http://arxiv.org/pdf/2309.15696v1
2309.15696v1
Breaking NoC Anonymity using Flow Correlation Attack
Network-on-Chip (NoC) is widely used as the internal communication fabric in today's multicore System-on-Chip (SoC) designs. Security of the on-chip communication is crucial because exploiting any vulnerability in shared NoC would be a goldmine for an attacker. NoC security relies on effective countermeasures against diverse attacks. We investigate the security strength of existing anonymous routing protocols in NoC architectures. Specifically, this paper makes two important contributions. We show that the existing anonymous routing is vulnerable to machine learning (ML) based flow correlation attacks on NoCs. We propose a lightweight anonymous routing that use traffic obfuscation techniques which can defend against ML-based flow correlation attacks. Experimental studies using both real and synthetic traffic reveal that our proposed attack is successful against state-of-the-art anonymous routing in NoC architectures with a high accuracy (up to 99%) for diverse traffic patterns, while our lightweight countermeasure can defend against ML-based attacks with minor hardware and performance overhead.
[ "Hansika Weerasena", "Pan Zhixin", "Khushboo Rani", "Prabhat Mishra" ]
2023-09-27 14:32:39
http://arxiv.org/abs/2309.15687v1
http://arxiv.org/pdf/2309.15687v1
2309.15687v1
Projection based fuzzy least squares twin support vector machine for class imbalance problems
Class imbalance is a major problem in many real world classification tasks. Due to the imbalance in the number of samples, the support vector machine (SVM) classifier gets biased toward the majority class. Furthermore, these samples are often observed with a certain degree of noise. Therefore, to remove these problems we propose a novel fuzzy based approach to deal with class imbalanced as well noisy datasets. We propose two approaches to address these problems. The first approach is based on the intuitionistic fuzzy membership, termed as robust energy-based intuitionistic fuzzy least squares twin support vector machine (IF-RELSTSVM). Furthermore, we introduce the concept of hyperplane-based fuzzy membership in our second approach, where the final classifier is termed as robust energy-based fuzzy least square twin support vector machine (F-RELSTSVM). By using this technique, the membership values are based on a projection based approach, where the data points are projected on the hyperplanes. The performance of the proposed algorithms is evaluated on several benchmark and synthetic datasets. The experimental results show that the proposed IF-RELSTSVM and F-RELSTSVM models outperform the baseline algorithms. Statistical tests are performed to check the significance of the proposed algorithms. The results show the applicability of the proposed algorithms on noisy as well as imbalanced datasets.
[ "M. Tanveer", "Ritik Mishra", "Bharat Richhariya" ]
2023-09-27 14:28:48
http://arxiv.org/abs/2309.15886v1
http://arxiv.org/pdf/2309.15886v1
2309.15886v1
Joint Sampling and Optimisation for Inverse Rendering
When dealing with difficult inverse problems such as inverse rendering, using Monte Carlo estimated gradients to optimise parameters can slow down convergence due to variance. Averaging many gradient samples in each iteration reduces this variance trivially. However, for problems that require thousands of optimisation iterations, the computational cost of this approach rises quickly. We derive a theoretical framework for interleaving sampling and optimisation. We update and reuse past samples with low-variance finite-difference estimators that describe the change in the estimated gradients between each iteration. By combining proportional and finite-difference samples, we continuously reduce the variance of our novel gradient meta-estimators throughout the optimisation process. We investigate how our estimator interlinks with Adam and derive a stable combination. We implement our method for inverse path tracing and demonstrate how our estimator speeds up convergence on difficult optimisation tasks.
[ "Martin Balint", "Karol Myszkowski", "Hans-Peter Seidel", "Gurprit Singh" ]
2023-09-27 14:21:13
http://arxiv.org/abs/2309.15676v1
http://arxiv.org/pdf/2309.15676v1
2309.15676v1
Speech collage: code-switched audio generation by collaging monolingual corpora
Designing effective automatic speech recognition (ASR) systems for Code-Switching (CS) often depends on the availability of the transcribed CS resources. To address data scarcity, this paper introduces Speech Collage, a method that synthesizes CS data from monolingual corpora by splicing audio segments. We further improve the smoothness quality of audio generation using an overlap-add approach. We investigate the impact of generated data on speech recognition in two scenarios: using in-domain CS text and a zero-shot approach with synthesized CS text. Empirical results highlight up to 34.4% and 16.2% relative reductions in Mixed-Error Rate and Word-Error Rate for in-domain and zero-shot scenarios, respectively. Lastly, we demonstrate that CS augmentation bolsters the model's code-switching inclination and reduces its monolingual bias.
[ "Amir Hussein", "Dorsa Zeinali", "Ondřej Klejch", "Matthew Wiesner", "Brian Yan", "Shammur Chowdhury", "Ahmed Ali", "Shinji Watanabe", "Sanjeev Khudanpur" ]
2023-09-27 14:17:53
http://arxiv.org/abs/2309.15674v1
http://arxiv.org/pdf/2309.15674v1
2309.15674v1
MONOVAB : An Annotated Corpus for Bangla Multi-label Emotion Detection
In recent years, Sentiment Analysis (SA) and Emotion Recognition (ER) have been increasingly popular in the Bangla language, which is the seventh most spoken language throughout the entire world. However, the language is structurally complicated, which makes this field arduous to extract emotions in an accurate manner. Several distinct approaches such as the extraction of positive and negative sentiments as well as multiclass emotions, have been implemented in this field of study. Nevertheless, the extraction of multiple sentiments is an almost untouched area in this language. Which involves identifying several feelings based on a single piece of text. Therefore, this study demonstrates a thorough method for constructing an annotated corpus based on scrapped data from Facebook to bridge the gaps in this subject area to overcome the challenges. To make this annotation more fruitful, the context-based approach has been used. Bidirectional Encoder Representations from Transformers (BERT), a well-known methodology of transformers, have been shown the best results of all methods implemented. Finally, a web application has been developed to demonstrate the performance of the pre-trained top-performer model (BERT) for multi-label ER in Bangla.
[ "Sumit Kumar Banshal", "Sajal Das", "Shumaiya Akter Shammi", "Narayan Ranjan Chakraborty" ]
2023-09-27 14:10:57
http://arxiv.org/abs/2309.15670v1
http://arxiv.org/pdf/2309.15670v1
2309.15670v1
On Computational Entanglement and Its Interpretation in Adversarial Machine Learning
Adversarial examples in machine learning has emerged as a focal point of research due to their remarkable ability to deceive models with seemingly inconspicuous input perturbations, potentially resulting in severe consequences. In this study, we embark on a comprehensive exploration of adversarial machine learning models, shedding light on their intrinsic complexity and interpretability. Our investigation reveals intriguing links between machine learning model complexity and Einstein's theory of special relativity, through the concept of entanglement. More specific, we define entanglement computationally and demonstrate that distant feature samples can exhibit strong correlations, akin to entanglement in quantum realm. This revelation challenges conventional perspectives in describing the phenomenon of adversarial transferability observed in contemporary machine learning models. By drawing parallels with the relativistic effects of time dilation and length contraction during computation, we gain deeper insights into adversarial machine learning, paving the way for more robust and interpretable models in this rapidly evolving field.
[ "YenLung Lai", "Xingbo Dong", "Zhe Jin" ]
2023-09-27 14:09:15
http://arxiv.org/abs/2309.15669v2
http://arxiv.org/pdf/2309.15669v2
2309.15669v2
Genetic Algorithm-Based Dynamic Backdoor Attack on Federated Learning-Based Network Traffic Classification
Federated learning enables multiple clients to collaboratively contribute to the learning of a global model orchestrated by a central server. This learning scheme promotes clients' data privacy and requires reduced communication overheads. In an application like network traffic classification, this helps hide the network vulnerabilities and weakness points. However, federated learning is susceptible to backdoor attacks, in which adversaries inject manipulated model updates into the global model. These updates inject a salient functionality in the global model that can be launched with specific input patterns. Nonetheless, the vulnerability of network traffic classification models based on federated learning to these attacks remains unexplored. In this paper, we propose GABAttack, a novel genetic algorithm-based backdoor attack against federated learning for network traffic classification. GABAttack utilizes a genetic algorithm to optimize the values and locations of backdoor trigger patterns, ensuring a better fit with the input and the model. This input-tailored dynamic attack is promising for improved attack evasiveness while being effective. Extensive experiments conducted over real-world network datasets validate the success of the proposed GABAttack in various situations while maintaining almost invisible activity. This research serves as an alarming call for network security experts and practitioners to develop robust defense measures against such attacks.
[ "Mahmoud Nazzal", "Nura Aljaafari", "Ahmed Sawalmeh", "Abdallah Khreishah", "Muhammad Anan", "Abdulelah Algosaibi", "Mohammed Alnaeem", "Adel Aldalbahi", "Abdulaziz Alhumam", "Conrado P. Vizcarra", "Shadan Alhamed" ]
2023-09-27 14:02:02
http://arxiv.org/abs/2310.06855v1
http://arxiv.org/pdf/2310.06855v1
2310.06855v1
Federated Deep Equilibrium Learning: A Compact Shared Representation for Edge Communication Efficiency
Federated Learning (FL) is a prominent distributed learning paradigm facilitating collaboration among nodes within an edge network to co-train a global model without centralizing data. By shifting computation to the network edge, FL offers robust and responsive edge-AI solutions and enhance privacy-preservation. However, deploying deep FL models within edge environments is often hindered by communication bottlenecks, data heterogeneity, and memory limitations. To address these challenges jointly, we introduce FeDEQ, a pioneering FL framework that effectively employs deep equilibrium learning and consensus optimization to exploit a compact shared data representation across edge nodes, allowing the derivation of personalized models specific to each node. We delve into a unique model structure composed of an equilibrium layer followed by traditional neural network layers. Here, the equilibrium layer functions as a global feature representation that edge nodes can adapt to personalize their local layers. Capitalizing on FeDEQ's compactness and representation power, we present a novel distributed algorithm rooted in the alternating direction method of multipliers (ADMM) consensus optimization and theoretically establish its convergence for smooth objectives. Experiments across various benchmarks demonstrate that FeDEQ achieves performance comparable to state-of-the-art personalized methods while employing models of up to 4 times smaller in communication size and 1.5 times lower memory footprint during training.
[ "Long Tan Le", "Tuan Dung Nguyen", "Tung-Anh Nguyen", "Choong Seon Hong", "Nguyen H. Tran" ]
2023-09-27 13:48:12
http://arxiv.org/abs/2309.15659v1
http://arxiv.org/pdf/2309.15659v1
2309.15659v1
Generative Speech Recognition Error Correction with Large Language Models and Task-Activating Prompting
We explore the ability of large language models (LLMs) to act as speech recognition post-processors that perform rescoring and error correction. Our first focus is on instruction prompting to let LLMs perform these task without fine-tuning, for which we evaluate different prompting schemes, both zero- and few-shot in-context learning, and a novel task activation prompting method that combines causal instructions and demonstration to increase its context windows. Next, we show that rescoring only by in-context learning with frozen LLMs achieves results that are competitive with rescoring by domain-tuned LMs, using a pretrained first-pass recognition system and rescoring output on two out-of-domain tasks (ATIS and WSJ). By combining prompting techniques with fine-tuning we achieve error rates below the N-best oracle level, showcasing the generalization power of the LLMs.
[ "Chao-Han Huck Yang", "Yile Gu", "Yi-Chieh Liu", "Shalini Ghosh", "Ivan Bulyko", "Andreas Stolcke" ]
2023-09-27 13:36:03
http://arxiv.org/abs/2309.15649v2
http://arxiv.org/pdf/2309.15649v2
2309.15649v2
SANGEA: Scalable and Attributed Network Generation
The topic of synthetic graph generators (SGGs) has recently received much attention due to the wave of the latest breakthroughs in generative modelling. However, many state-of-the-art SGGs do not scale well with the graph size. Indeed, in the generation process, all the possible edges for a fixed number of nodes must often be considered, which scales in $\mathcal{O}(N^2)$, with $N$ being the number of nodes in the graph. For this reason, many state-of-the-art SGGs are not applicable to large graphs. In this paper, we present SANGEA, a sizeable synthetic graph generation framework which extends the applicability of any SGG to large graphs. By first splitting the large graph into communities, SANGEA trains one SGG per community, then links the community graphs back together to create a synthetic large graph. Our experiments show that the graphs generated by SANGEA have high similarity to the original graph, in terms of both topology and node feature distribution. Additionally, these generated graphs achieve high utility on downstream tasks such as link prediction. Finally, we provide a privacy assessment of the generated graphs to show that, even though they have excellent utility, they also achieve reasonable privacy scores.
[ "Valentin Lemaire", "Youssef Achenchabe", "Lucas Ody", "Houssem Eddine Souid", "Gianmarco Aversano", "Nicolas Posocco", "Sabri Skhiri" ]
2023-09-27 13:35:45
http://arxiv.org/abs/2309.15648v1
http://arxiv.org/pdf/2309.15648v1
2309.15648v1
Cold & Warm Net: Addressing Cold-Start Users in Recommender Systems
Cold-start recommendation is one of the major challenges faced by recommender systems (RS). Herein, we focus on the user cold-start problem. Recently, methods utilizing side information or meta-learning have been used to model cold-start users. However, it is difficult to deploy these methods to industrial RS. There has not been much research that pays attention to the user cold-start problem in the matching stage. In this paper, we propose Cold & Warm Net based on expert models who are responsible for modeling cold-start and warm-up users respectively. A gate network is applied to incorporate the results from two experts. Furthermore, dynamic knowledge distillation acting as a teacher selector is introduced to assist experts in better learning user representation. With comprehensive mutual information, features highly relevant to user behavior are selected for the bias net which explicitly models user behavior bias. Finally, we evaluate our Cold & Warm Net on public datasets in comparison to models commonly applied in the matching stage and it outperforms other models on all user types. The proposed model has also been deployed on an industrial short video platform and achieves a significant increase in app dwell time and user retention rate.
[ "Xiangyu Zhang", "Zongqiang Kuang", "Zehao Zhang", "Fan Huang", "Xianfeng Tan" ]
2023-09-27 13:31:43
http://arxiv.org/abs/2309.15646v1
http://arxiv.org/pdf/2309.15646v1
2309.15646v1
Why do Angular Margin Losses work well for Semi-Supervised Anomalous Sound Detection?
State-of-the-art anomalous sound detection systems often utilize angular margin losses to learn suitable representations of acoustic data using an auxiliary task, which usually is a supervised or self-supervised classification task. The underlying idea is that, in order to solve this auxiliary task, specific information about normal data needs to be captured in the learned representations and that this information is also sufficient to differentiate between normal and anomalous samples. Especially in noisy conditions, discriminative models based on angular margin losses tend to significantly outperform systems based on generative or one-class models. The goal of this work is to investigate why using angular margin losses with auxiliary tasks works well for detecting anomalous sounds. To this end, it is shown, both theoretically and experimentally, that minimizing angular margin losses also minimizes compactness loss while inherently preventing learning trivial solutions. Furthermore, multiple experiments are conducted to show that using a related classification task as an auxiliary task teaches the model to learn representations suitable for detecting anomalous sounds in noisy conditions. Among these experiments are performance evaluations, visualizing the embedding space with t-SNE and visualizing the input representations with respect to the anomaly score using randomized input sampling for explanation.
[ "Kevin Wilkinghoff", "Frank Kurth" ]
2023-09-27 13:29:38
http://arxiv.org/abs/2309.15643v1
http://arxiv.org/pdf/2309.15643v1
2309.15643v1
Efficient tensor network simulation of IBM's largest quantum processors
We show how quantum-inspired 2d tensor networks can be used to efficiently and accurately simulate the largest quantum processors from IBM, namely Eagle (127 qubits), Osprey (433 qubits) and Condor (1121 qubits). We simulate the dynamics of a complex quantum many-body system -- specifically, the kicked Ising experiment considered recently by IBM in Nature 618, p. 500-505 (2023) -- using graph-based Projected Entangled Pair States (gPEPS), which was proposed by some of us in PRB 99, 195105 (2019). Our results show that simple tensor updates are already sufficient to achieve very large unprecedented accuracy with remarkably low computational resources for this model. Apart from simulating the original experiment for 127 qubits, we also extend our results to 433 and 1121 qubits, and for evolution times around 8 times longer, thus setting a benchmark for the newest IBM quantum machines. We also report accurate simulations for infinitely-many qubits. Our results show that gPEPS are a natural tool to efficiently simulate quantum computers with an underlying lattice-based qubit connectivity, such as all quantum processors based on superconducting qubits.
[ "Siddhartha Patra", "Saeed S. Jahromi", "Sukhbinder Singh", "Roman Orus" ]
2023-09-27 13:27:01
http://arxiv.org/abs/2309.15642v2
http://arxiv.org/pdf/2309.15642v2
2309.15642v2
Hedging Properties of Algorithmic Investment Strategies using Long Short-Term Memory and Time Series models for Equity Indices
This paper proposes a novel approach to hedging portfolios of risky assets when financial markets are affected by financial turmoils. We introduce a completely novel approach to diversification activity not on the level of single assets but on the level of ensemble algorithmic investment strategies (AIS) built based on the prices of these assets. We employ four types of diverse theoretical models (LSTM - Long Short-Term Memory, ARIMA-GARCH - Autoregressive Integrated Moving Average - Generalized Autoregressive Conditional Heteroskedasticity, momentum, and contrarian) to generate price forecasts, which are then used to produce investment signals in single and complex AIS. In such a way, we are able to verify the diversification potential of different types of investment strategies consisting of various assets (energy commodities, precious metals, cryptocurrencies, or soft commodities) in hedging ensemble AIS built for equity indices (S&P 500 index). Empirical data used in this study cover the period between 2004 and 2022. Our main conclusion is that LSTM-based strategies outperform the other models and that the best diversifier for the AIS built for the S&P 500 index is the AIS built for Bitcoin. Finally, we test the LSTM model for a higher frequency of data (1 hour). We conclude that it outperforms the results obtained using daily data.
[ "Jakub Michańków", "Paweł Sakowski", "Robert Ślepaczuk" ]
2023-09-27 13:18:39
http://arxiv.org/abs/2309.15640v1
http://arxiv.org/pdf/2309.15640v1
2309.15640v1
Enhancing Sharpness-Aware Optimization Through Variance Suppression
Sharpness-aware minimization (SAM) has well documented merits in enhancing generalization of deep neural networks, even without sizable data augmentation. Embracing the geometry of the loss function, where neighborhoods of 'flat minima' heighten generalization ability, SAM seeks 'flat valleys' by minimizing the maximum loss caused by an adversary perturbing parameters within the neighborhood. Although critical to account for sharpness of the loss function, such an 'over-friendly adversary' can curtail the outmost level of generalization. The novel approach of this contribution fosters stabilization of adversaries through variance suppression (VaSSO) to avoid such friendliness. VaSSO's provable stability safeguards its numerical improvement over SAM in model-agnostic tasks, including image classification and machine translation. In addition, experiments confirm that VaSSO endows SAM with robustness against high levels of label noise.
[ "Bingcong Li", "Georgios B. Giannakis" ]
2023-09-27 13:18:23
http://arxiv.org/abs/2309.15639v2
http://arxiv.org/pdf/2309.15639v2
2309.15639v2
FRS-Nets: Fourier Parameterized Rotation and Scale Equivariant Networks for Retinal Vessel Segmentation
With translation equivariance, convolution neural networks (CNNs) have achieved great success in retinal vessel segmentation. However, some other symmetries of the vascular morphology are not characterized by CNNs, such as rotation and scale symmetries. To embed more equivariance into CNNs and achieve the accuracy requirement for retinal vessel segmentation, we construct a novel convolution operator (FRS-Conv), which is Fourier parameterized and equivariant to rotation and scaling. Specifically, we first adopt a new parameterization scheme, which enables convolutional filters to arbitrarily perform transformations with high accuracy. Secondly, we derive the formulations for the rotation and scale equivariant convolution mapping. Finally, we construct FRS-Conv following the proposed formulations and replace the traditional convolution filters in U-Net and Iter-Net with FRS-Conv (FRS-Nets). We faithfully reproduce all compared methods and conduct comprehensive experiments on three public datasets under both in-dataset and cross-dataset settings. With merely 13.9% parameters of corresponding baselines, FRS-Nets have achieved state-of-the-art performance and significantly outperform all compared methods. It demonstrates the remarkable accuracy, generalization, and clinical application potential of FRS-Nets.
[ "Zihong Sun", "Qi Xie", "Deyu Meng" ]
2023-09-27 13:14:57
http://arxiv.org/abs/2309.15638v1
http://arxiv.org/pdf/2309.15638v1
2309.15638v1
An Empirical Study of AI Generated Text Detection Tools
Since ChatGPT has emerged as a major AIGC model, providing high-quality responses across a wide range of applications (including software development and maintenance), it has attracted much interest from many individuals. ChatGPT has great promise, but there are serious problems that might arise from its misuse, especially in the realms of education and public safety. Several AIGC detectors are available, and they have all been tested on genuine text. However, more study is needed to see how effective they are for multi-domain ChatGPT material. This study aims to fill this need by creating a multi-domain dataset for testing the state-of-the-art APIs and tools for detecting artificially generated information used by universities and other research institutions. A large dataset consisting of articles, abstracts, stories, news, and product reviews was created for this study. The second step is to use the newly created dataset to put six tools through their paces. Six different artificial intelligence (AI) text identification systems, including "GPTkit," "GPTZero," "Originality," "Sapling," "Writer," and "Zylalab," have accuracy rates between 55.29 and 97.0%. Although all the tools fared well in the evaluations, originality was particularly effective across the board.
[ "Arslan Akram" ]
2023-09-27 12:44:12
http://arxiv.org/abs/2310.01423v1
http://arxiv.org/pdf/2310.01423v1
2310.01423v1
Developing automatic verbatim transcripts for international multilingual meetings: an end-to-end solution
This paper presents an end-to-end solution for the creation of fully automated conference meeting transcripts and their machine translations into various languages. This tool has been developed at the World Intellectual Property Organization (WIPO) using in-house developed speech-to-text (S2T) and machine translation (MT) components. Beyond describing data collection and fine-tuning, resulting in a highly customized and robust system, this paper describes the architecture and evolution of the technical components as well as highlights the business impact and benefits from the user side. We also point out particular challenges in the evolution and adoption of the system and how the new approach created a new product and replaced existing established workflows in conference management documentation.
[ "Akshat Dewan", "Michal Ziemski", "Henri Meylan", "Lorenzo Concina", "Bruno Pouliquen" ]
2023-09-27 12:16:15
http://arxiv.org/abs/2309.15609v1
http://arxiv.org/pdf/2309.15609v1
2309.15609v1
NoSENSE: Learned unrolled cardiac MRI reconstruction without explicit sensitivity maps
We present a novel learned image reconstruction method for accelerated cardiac MRI with multiple receiver coils based on deep convolutional neural networks (CNNs) and algorithm unrolling. In contrast to many existing learned MR image reconstruction techniques that necessitate coil-sensitivity map (CSM) estimation as a distinct network component, our proposed approach avoids explicit CSM estimation. Instead, it implicitly captures and learns to exploit the inter-coil relationships of the images. Our method consists of a series of novel learned image and k-space blocks with shared latent information and adaptation to the acquisition parameters by feature-wise modulation (FiLM), as well as coil-wise data-consistency (DC) blocks. Our method achieved PSNR values of 34.89 and 35.56 and SSIM values of 0.920 and 0.942 in the cine track and mapping track validation leaderboard of the MICCAI STACOM CMRxRecon Challenge, respectively, ranking 4th among different teams at the time of writing. Code will be made available at https://github.com/fzimmermann89/CMRxRecon
[ "Felix Frederik Zimmermann", "Andreas Kofler" ]
2023-09-27 12:15:05
http://arxiv.org/abs/2309.15608v1
http://arxiv.org/pdf/2309.15608v1
2309.15608v1
Entropic Matching for Expectation Propagation of Markov Jump Processes
This paper addresses the problem of statistical inference for latent continuous-time stochastic processes, which is often intractable, particularly for discrete state space processes described by Markov jump processes. To overcome this issue, we propose a new tractable inference scheme based on an entropic matching framework that can be embedded into the well-known expectation propagation algorithm. We demonstrate the effectiveness of our method by providing closed-form results for a simple family of approximate distributions and apply it to the general class of chemical reaction networks, which are a crucial tool for modeling in systems biology. Moreover, we derive closed form expressions for point estimation of the underlying parameters using an approximate expectation maximization procedure. We evaluate the performance of our method on various chemical reaction network instantiations, including a stochastic Lotka-Voltera example, and discuss its limitations and potential for future improvements. Our proposed approach provides a promising direction for addressing complex continuous-time Bayesian inference problems.
[ "Bastian Alt", "Heinz Koeppl" ]
2023-09-27 12:07:21
http://arxiv.org/abs/2309.15604v1
http://arxiv.org/pdf/2309.15604v1
2309.15604v1
Distill Knowledge in Multi-task Reinforcement Learning with Optimal-Transport Regularization
In multi-task reinforcement learning, it is possible to improve the data efficiency of training agents by transferring knowledge from other different but related tasks. Because the experiences from different tasks are usually biased toward the specific task goals. Traditional methods rely on Kullback-Leibler regularization to stabilize the transfer of knowledge from one task to the others. In this work, we explore the direction of replacing the Kullback-Leibler divergence with a novel Optimal transport-based regularization. By using the Sinkhorn mapping, we can approximate the Optimal transport distance between the state distribution of tasks. The distance is then used as an amortized reward to regularize the amount of sharing information. We experiment our frameworks on several grid-based navigation multi-goal to validate the effectiveness of the approach. The results show that our added Optimal transport-based rewards are able to speed up the learning process of agents and outperforms several baselines on multi-task learning.
[ "Bang Giang Le", "Viet Cuong Ta" ]
2023-09-27 12:06:34
http://arxiv.org/abs/2309.15603v1
http://arxiv.org/pdf/2309.15603v1
2309.15603v1
OceanBench: The Sea Surface Height Edition
The ocean profoundly influences human activities and plays a critical role in climate regulation. Our understanding has improved over the last decades with the advent of satellite remote sensing data, allowing us to capture essential quantities over the globe, e.g., sea surface height (SSH). However, ocean satellite data presents challenges for information extraction due to their sparsity and irregular sampling, signal complexity, and noise. Machine learning (ML) techniques have demonstrated their capabilities in dealing with large-scale, complex signals. Therefore we see an opportunity for ML models to harness the information contained in ocean satellite data. However, data representation and relevant evaluation metrics can be the defining factors when determining the success of applied ML. The processing steps from the raw observation data to a ML-ready state and from model outputs to interpretable quantities require domain expertise, which can be a significant barrier to entry for ML researchers. OceanBench is a unifying framework that provides standardized processing steps that comply with domain-expert standards. It provides plug-and-play data and pre-configured pipelines for ML researchers to benchmark their models and a transparent configurable framework for researchers to customize and extend the pipeline for their tasks. In this work, we demonstrate the OceanBench framework through a first edition dedicated to SSH interpolation challenges. We provide datasets and ML-ready benchmarking pipelines for the long-standing problem of interpolating observations from simulated ocean satellite data, multi-modal and multi-sensor fusion issues, and transfer-learning to real ocean satellite observations. The OceanBench framework is available at github.com/jejjohnson/oceanbench and the dataset registry is available at github.com/quentinf00/oceanbench-data-registry.
[ "J. Emmanuel Johnson", "Quentin Febvre", "Anastasia Gorbunova", "Sammy Metref", "Maxime Ballarotta", "Julien Le Sommer", "Ronan Fablet" ]
2023-09-27 12:00:40
http://arxiv.org/abs/2309.15599v1
http://arxiv.org/pdf/2309.15599v1
2309.15599v1
Exciton-Polariton Condensates: A Fourier Neural Operator Approach
Advancements in semiconductor fabrication over the past decade have catalyzed extensive research into all-optical devices driven by exciton-polariton condensates. Preliminary validations of such devices, including transistors, have shown encouraging results even under ambient conditions. A significant challenge still remains for large scale application however: the lack of a robust solver that can be used to simulate complex nonlinear systems which require an extended period of time to stabilize. Addressing this need, we propose the application of a machine-learning-based Fourier Neural Operator approach to find the solution to the Gross-Pitaevskii equations coupled with extra exciton rate equations. This work marks the first direct application of Neural Operators to an exciton-polariton condensate system. Our findings show that the proposed method can predict final-state solutions to a high degree of accuracy almost 1000 times faster than CUDA-based GPU solvers. Moreover, this paves the way for potential all-optical chip design workflows by integrating experimental data.
[ "Surya T. Sathujoda", "Yuan Wang", "Kanishk Gandhi" ]
2023-09-27 11:47:26
http://arxiv.org/abs/2309.15593v1
http://arxiv.org/pdf/2309.15593v1
2309.15593v1
Demographic Parity: Mitigating Biases in Real-World Data
Computer-based decision systems are widely used to automate decisions in many aspects of everyday life, which include sensitive areas like hiring, loaning and even criminal sentencing. A decision pipeline heavily relies on large volumes of historical real-world data for training its models. However, historical training data often contains gender, racial or other biases which are propagated to the trained models influencing computer-based decisions. In this work, we propose a robust methodology that guarantees the removal of unwanted biases while maximally preserving classification utility. Our approach can always achieve this in a model-independent way by deriving from real-world data the asymptotic dataset that uniquely encodes demographic parity and realism. As a proof-of-principle, we deduce from public census records such an asymptotic dataset from which synthetic samples can be generated to train well-established classifiers. Benchmarking the generalization capability of these classifiers trained on our synthetic data, we confirm the absence of any explicit or implicit bias in the computer-aided decision.
[ "Orestis Loukas", "Ho-Ryun Chung" ]
2023-09-27 11:47:05
http://arxiv.org/abs/2309.17347v1
http://arxiv.org/pdf/2309.17347v1
2309.17347v1
Jointly Training Large Autoregressive Multimodal Models
In recent years, advances in the large-scale pretraining of language and text-to-image models have revolutionized the field of machine learning. Yet, integrating these two modalities into a single, robust model capable of generating seamless multimodal outputs remains a significant challenge. To address this gap, we present the Joint Autoregressive Mixture (JAM) framework, a modular approach that systematically fuses existing text and image generation models. We also introduce a specialized, data-efficient instruction-tuning strategy, tailored for mixed-modal generation tasks. Our final instruct-tuned model demonstrates unparalleled performance in generating high-quality multimodal outputs and represents the first model explicitly designed for this purpose.
[ "Emanuele Aiello", "Lili Yu", "Yixin Nie", "Armen Aghajanyan", "Barlas Oguz" ]
2023-09-27 10:40:23
http://arxiv.org/abs/2309.15564v2
http://arxiv.org/pdf/2309.15564v2
2309.15564v2
Identifiability Matters: Revealing the Hidden Recoverable Condition in Unbiased Learning to Rank
The application of Unbiased Learning to Rank (ULTR) is widespread in modern systems for training unbiased ranking models from biased click logs. The key is to explicitly model a generation process for user behavior and fit click data based on examination hypothesis. Previous research found empirically that the true latent relevance can be recovered in most cases as long as the clicks are perfectly fitted. However, we demonstrate that this is not always achievable, resulting in a significant reduction in ranking performance. In this work, we aim to answer if or when the true relevance can be recovered from click data, which is a foundation issue for ULTR field. We first define a ranking model as identifiable if it can recover the true relevance up to a scaling transformation, which is enough for pairwise ranking objective. Then we explore an equivalent condition for identifiability that can be novely expressed as a graph connectivity test problem: if and only if a graph (namely identifiability graph, or IG) constructed on the underlying structure of the dataset is connected, we can guarantee that the relevance can be correctly recovered. When the IG is not connected, there may be bad cases leading to poor ranking performance. To address this issue, we propose two methods, namely node intervention and node merging, to modify the dataset and restore connectivity of the IG. Empirical results obtained on a simulation dataset and two LTR benchmark datasets confirm the validity of our proposed theorems and show the effectiveness of our methods in mitigating data bias when the relevance model is unidentifiable.
[ "Mouxiang Chen", "Chenghao Liu", "Zemin Liu", "Zhuo Li", "Jianling Sun" ]
2023-09-27 10:31:58
http://arxiv.org/abs/2309.15560v1
http://arxiv.org/pdf/2309.15560v1
2309.15560v1
Towards Faithful Neural Network Intrinsic Interpretation with Shapley Additive Self-Attribution
Self-interpreting neural networks have garnered significant interest in research. Existing works in this domain often (1) lack a solid theoretical foundation ensuring genuine interpretability or (2) compromise model expressiveness. In response, we formulate a generic Additive Self-Attribution (ASA) framework. Observing the absence of Shapley value in Additive Self-Attribution, we propose Shapley Additive Self-Attributing Neural Network (SASANet), with theoretical guarantees for the self-attribution value equal to the output's Shapley values. Specifically, SASANet uses a marginal contribution-based sequential schema and internal distillation-based training strategies to model meaningful outputs for any number of features, resulting in un-approximated meaningful value function. Our experimental results indicate SASANet surpasses existing self-attributing models in performance and rivals black-box models. Moreover, SASANet is shown more precise and efficient than post-hoc methods in interpreting its own predictions.
[ "Ying Sun", "Hengshu Zhu", "Hui Xiong" ]
2023-09-27 10:31:48
http://arxiv.org/abs/2309.15559v1
http://arxiv.org/pdf/2309.15559v1
2309.15559v1
Startup success prediction and VC portfolio simulation using CrunchBase data
Predicting startup success presents a formidable challenge due to the inherently volatile landscape of the entrepreneurial ecosystem. The advent of extensive databases like Crunchbase jointly with available open data enables the application of machine learning and artificial intelligence for more accurate predictive analytics. This paper focuses on startups at their Series B and Series C investment stages, aiming to predict key success milestones such as achieving an Initial Public Offering (IPO), attaining unicorn status, or executing a successful Merger and Acquisition (M\&A). We introduce novel deep learning model for predicting startup success, integrating a variety of factors such as funding metrics, founder features, industry category. A distinctive feature of our research is the use of a comprehensive backtesting algorithm designed to simulate the venture capital investment process. This simulation allows for a robust evaluation of our model's performance against historical data, providing actionable insights into its practical utility in real-world investment contexts. Evaluating our model on Crunchbase's, we achieved a 14 times capital growth and successfully identified on B round high-potential startups including Revolut, DigitalOcean, Klarna, Github and others. Our empirical findings illuminate the importance of incorporating diverse feature sets in enhancing the model's predictive accuracy. In summary, our work demonstrates the considerable promise of deep learning models and alternative unstructured data in predicting startup success and sets the stage for future advancements in this research area.
[ "Mark Potanin", "Andrey Chertok", "Konstantin Zorin", "Cyril Shtabtsovsky" ]
2023-09-27 10:22:37
http://arxiv.org/abs/2309.15552v1
http://arxiv.org/pdf/2309.15552v1
2309.15552v1
Identifying confounders in deep-learning-based model predictions using DeepRepViz
Deep Learning (DL) models are increasingly used to analyze neuroimaging data and uncover insights about the brain, brain pathologies, and psychological traits. However, extraneous `confounders' variables such as the age of the participants, sex, or imaging artifacts can bias model predictions, preventing the models from learning relevant brain-phenotype relationships. In this study, we provide a solution called the `DeepRepViz' framework that enables researchers to systematically detect confounders in their DL model predictions. The framework consists of (1) a metric that quantifies the effect of potential confounders and (2) a visualization tool that allows researchers to qualitatively inspect what the DL model is learning. By performing experiments on simulated and neuroimaging datasets, we demonstrate the benefits of using DeepRepViz in combination with DL models. For example, experiments on the neuroimaging datasets reveal that sex is a significant confounder in a DL model predicting chronic alcohol users (Con-score=0.35). Similarly, DeepRepViz identifies age as a confounder in a DL model predicting participants' performance on a cognitive task (Con-score=0.3). Overall, DeepRepViz enables researchers to systematically test for potential confounders and expose DL models that rely on extraneous information such as age, sex, or imaging artifacts.
[ "Roshan Prakash Rane", "JiHoon Kim", "Arjun Umesha", "Didem Stark", "Marc-André Schulz", "Kerstin Ritter" ]
2023-09-27 10:20:45
http://arxiv.org/abs/2309.15551v1
http://arxiv.org/pdf/2309.15551v1
2309.15551v1
From LAION-5B to LAION-EO: Filtering Billions of Images Using Anchor Datasets for Satellite Image Extraction
Large datasets, such as LAION-5B, contain a diverse distribution of images shared online. However, extraction of domain-specific subsets of large image corpora is challenging. The extraction approach based on an anchor dataset, combined with further filtering, is proposed here and demonstrated for the domain of satellite imagery. This results in the release of LAION-EO, a dataset sourced from the web containing pairs of text and satellite images in high (pixel-wise) resolution. The paper outlines the acquisition procedure as well as some of the features of the dataset.
[ "Mikolaj Czerkawski", "Alistair Francis" ]
2023-09-27 09:53:38
http://arxiv.org/abs/2309.15535v1
http://arxiv.org/pdf/2309.15535v1
2309.15535v1
Uncertainty Quantification via Neural Posterior Principal Components
Uncertainty quantification is crucial for the deployment of image restoration models in safety-critical domains, like autonomous driving and biological imaging. To date, methods for uncertainty visualization have mainly focused on per-pixel estimates. However, a heatmap of per-pixel variances is typically of little practical use, as it does not capture the strong correlations between pixels. A more natural measure of uncertainty corresponds to the variances along the principal components (PCs) of the posterior distribution. Theoretically, the PCs can be computed by applying PCA on samples generated from a conditional generative model for the input image. However, this requires generating a very large number of samples at test time, which is painfully slow with the current state-of-the-art (diffusion) models. In this work, we present a method for predicting the PCs of the posterior distribution for any input image, in a single forward pass of a neural network. Our method can either wrap around a pre-trained model that was trained to minimize the mean square error (MSE), or can be trained from scratch to output both a predicted image and the posterior PCs. We showcase our method on multiple inverse problems in imaging, including denoising, inpainting, super-resolution, and biological image-to-image translation. Our method reliably conveys instance-adaptive uncertainty directions, achieving uncertainty quantification comparable with posterior samplers while being orders of magnitude faster. Examples are available at https://eliasnehme.github.io/NPPC/
[ "Elias Nehme", "Omer Yair", "Tomer Michaeli" ]
2023-09-27 09:51:29
http://arxiv.org/abs/2309.15533v1
http://arxiv.org/pdf/2309.15533v1
2309.15533v1
Rethinking Channel Dimensions to Isolate Outliers for Low-bit Weight Quantization of Large Language Models
Large Language Models (LLMs) have recently demonstrated a remarkable success across various tasks. However, efficiently serving LLMs has been a challenge due to its large memory bottleneck, specifically in small batch inference settings (e.g. mobile devices). Weight-only quantization can be a promising approach, but sub-4 bit quantization remains a challenge due to large-magnitude activation outliers. To mitigate the undesirable outlier effect, we first propose per-IC quantization, a simple yet effective method that creates quantization groups within each input channel (IC) rather than the conventional per-output channel (OC). Our method is motivated by the observation that activation outliers affect the input dimension of the weight matrix, so similarly grouping the weights in the IC direction can isolate outliers to be within a group. We also find that activation outliers do not dictate quantization difficulty, and inherent weight sensitivities also exist. With per-IC quantization as a new outlier-friendly scheme, we then propose Adaptive Dimensions (AdaDim), a versatile quantization framework that can adapt to various weight sensitivity patterns. We demonstrate the effectiveness of AdaDim by augmenting prior methods such as Round-To-Nearest and GPTQ, showing significant improvements across various language modeling benchmarks for both base (up to +4.7% on MMLU) and instruction-tuned (up to +10% on HumanEval) LLMs.
[ "Jung Hwan Heo", "Jeonghoon Kim", "Beomseok Kwon", "Byeongwook Kim", "Se Jung Kwon", "Dongsoo Lee" ]
2023-09-27 09:48:31
http://arxiv.org/abs/2309.15531v1
http://arxiv.org/pdf/2309.15531v1
2309.15531v1
Missing-modality Enabled Multi-modal Fusion Architecture for Medical Data
Fusing multi-modal data can improve the performance of deep learning models. However, missing modalities are common for medical data due to patients' specificity, which is detrimental to the performance of multi-modal models in applications. Therefore, it is critical to adapt the models to missing modalities. This study aimed to develop an efficient multi-modal fusion architecture for medical data that was robust to missing modalities and further improved the performance on disease diagnosis.X-ray chest radiographs for the image modality, radiology reports for the text modality, and structured value data for the tabular data modality were fused in this study. Each modality pair was fused with a Transformer-based bi-modal fusion module, and the three bi-modal fusion modules were then combined into a tri-modal fusion framework. Additionally, multivariate loss functions were introduced into the training process to improve model's robustness to missing modalities in the inference process. Finally, we designed comparison and ablation experiments for validating the effectiveness of the fusion, the robustness to missing modalities and the enhancements from each key component. Experiments were conducted on MIMIC-IV, MIMIC-CXR with the 14-label disease diagnosis task. Areas under the receiver operating characteristic curve (AUROC), the area under the precision-recall curve (AUPRC) were used to evaluate models' performance. The experimental results demonstrated that our proposed multi-modal fusion architecture effectively fused three modalities and showed strong robustness to missing modalities. This method is hopeful to be scaled to more modalities to enhance the clinical practicality of the model.
[ "Muyu Wang", "Shiyu Fan", "Yichen Li", "Hui Chen" ]
2023-09-27 09:46:07
http://arxiv.org/abs/2309.15529v1
http://arxiv.org/pdf/2309.15529v1
2309.15529v1
Robust Internal Representations for Domain Generalization
This paper which is part of the New Faculty Highlights Invited Speaker Program of AAAI'23, serves as a comprehensive survey of my research in transfer learning by utilizing embedding spaces. The work reviewed in this paper specifically revolves around the inherent challenges associated with continual learning and limited availability of labeled data. By providing an overview of my past and ongoing contributions, this paper aims to present a holistic understanding of my research, paving the way for future explorations and advancements in the field. My research delves into the various settings of transfer learning, including, few-shot learning, zero-shot learning, continual learning, domain adaptation, and distributed learning. I hope this survey provides a forward-looking perspective for researchers who would like to focus on similar research directions.
[ "Mohammad Rostami" ]
2023-09-27 09:41:02
http://arxiv.org/abs/2309.15522v1
http://arxiv.org/pdf/2309.15522v1
2309.15522v1
MLOps for Scarce Image Data: A Use Case in Microscopic Image Analysis
Nowadays, Machine Learning (ML) is experiencing tremendous popularity that has never been seen before. The operationalization of ML models is governed by a set of concepts and methods referred to as Machine Learning Operations (MLOps). Nevertheless, researchers, as well as professionals, often focus more on the automation aspect and neglect the continuous deployment and monitoring aspects of MLOps. As a result, there is a lack of continuous learning through the flow of feedback from production to development, causing unexpected model deterioration over time due to concept drifts, particularly when dealing with scarce data. This work explores the complete application of MLOps in the context of scarce data analysis. The paper proposes a new holistic approach to enhance biomedical image analysis. Our method includes: a fingerprinting process that enables selecting the best models, datasets, and model development strategy relative to the image analysis task at hand; an automated model development stage; and a continuous deployment and monitoring process to ensure continuous learning. For preliminary results, we perform a proof of concept for fingerprinting in microscopic image datasets.
[ "Angelo Yamachui Sitcheu", "Nils Friederich", "Simon Baeuerle", "Oliver Neumann", "Markus Reischl", "Ralf Mikut" ]
2023-09-27 09:39:45
http://arxiv.org/abs/2309.15521v2
http://arxiv.org/pdf/2309.15521v2
2309.15521v2
SAF-Net: Self-Attention Fusion Network for Myocardial Infarction Detection using Multi-View Echocardiography
Myocardial infarction (MI) is a severe case of coronary artery disease (CAD) and ultimately, its detection is substantial to prevent progressive damage to the myocardium. In this study, we propose a novel view-fusion model named self-attention fusion network (SAF-Net) to detect MI from multi-view echocardiography recordings. The proposed framework utilizes apical 2-chamber (A2C) and apical 4-chamber (A4C) view echocardiography recordings for classification. Three reference frames are extracted from each recording of both views and deployed pre-trained deep networks to extract highly representative features. The SAF-Net model utilizes a self-attention mechanism to learn dependencies in extracted feature vectors. The proposed model is computationally efficient thanks to its compact architecture having three main parts: a feature embedding to reduce dimensionality, self-attention for view-pooling, and dense layers for the classification. Experimental evaluation is performed using the HMC-QU-TAU dataset which consists of 160 patients with A2C and A4C view echocardiography recordings. The proposed SAF-Net model achieves a high-performance level with 88.26% precision, 77.64% sensitivity, and 78.13% accuracy. The results demonstrate that the SAF-Net model achieves the most accurate MI detection over multi-view echocardiography recordings.
[ "Ilke Adalioglu", "Mete Ahishali", "Aysen Degerli", "Serkan Kiranyaz", "Moncef Gabbouj" ]
2023-09-27 09:38:03
http://arxiv.org/abs/2309.15520v1
http://arxiv.org/pdf/2309.15520v1
2309.15520v1
Enhancing Cross-Category Learning in Recommendation Systems with Multi-Layer Embedding Training
Modern DNN-based recommendation systems rely on training-derived embeddings of sparse features. Input sparsity makes obtaining high-quality embeddings for rarely-occurring categories harder as their representations are updated infrequently. We demonstrate a training-time technique to produce superior embeddings via effective cross-category learning and theoretically explain its surprising effectiveness. The scheme, termed the multi-layer embeddings training (MLET), trains embeddings using factorization of the embedding layer, with an inner dimension higher than the target embedding dimension. For inference efficiency, MLET converts the trained two-layer embedding into a single-layer one thus keeping inference-time model size unchanged. Empirical superiority of MLET is puzzling as its search space is not larger than that of the single-layer embedding. The strong dependence of MLET on the inner dimension is even more surprising. We develop a theory that explains both of these behaviors by showing that MLET creates an adaptive update mechanism modulated by the singular vectors of embeddings. When tested on multiple state-of-the-art recommendation models for click-through rate (CTR) prediction tasks, MLET consistently produces better models, especially for rare items. At constant model quality, MLET allows embedding dimension, and model size, reduction by up to 16x, and 5.8x on average, across the models.
[ "Zihao Deng", "Benjamin Ghaemmaghami", "Ashish Kumar Singh", "Benjamin Cho", "Leo Orshansky", "Mattan Erez", "Michael Orshansky" ]
2023-09-27 09:32:10
http://arxiv.org/abs/2309.15881v1
http://arxiv.org/pdf/2309.15881v1
2309.15881v1
GNN4EEG: A Benchmark and Toolkit for Electroencephalography Classification with Graph Neural Network
Electroencephalography(EEG) classification is a crucial task in neuroscience, neural engineering, and several commercial applications. Traditional EEG classification models, however, have often overlooked or inadequately leveraged the brain's topological information. Recognizing this shortfall, there has been a burgeoning interest in recent years in harnessing the potential of Graph Neural Networks (GNN) to exploit the topological information by modeling features selected from each EEG channel in a graph structure. To further facilitate research in this direction, we introduce GNN4EEG, a versatile and user-friendly toolkit for GNN-based modeling of EEG signals. GNN4EEG comprises three components: (i)A large benchmark constructed with four EEG classification tasks based on EEG data collected from 123 participants. (ii)Easy-to-use implementations on various state-of-the-art GNN-based EEG classification models, e.g., DGCNN, RGNN, etc. (iii)Implementations of comprehensive experimental settings and evaluation protocols, e.g., data splitting protocols, and cross-validation protocols. GNN4EEG is publicly released at https://github.com/Miracle-2001/GNN4EEG.
[ "Kaiyuan Zhang", "Ziyi Ye", "Qingyao Ai", "Xiaohui Xie", "Yiqun Liu" ]
2023-09-27 09:31:13
http://arxiv.org/abs/2309.15515v1
http://arxiv.org/pdf/2309.15515v1
2309.15515v1
Finite Scalar Quantization: VQ-VAE Made Simple
We propose to replace vector quantization (VQ) in the latent representation of VQ-VAEs with a simple scheme termed finite scalar quantization (FSQ), where we project the VAE representation down to a few dimensions (typically less than 10). Each dimension is quantized to a small set of fixed values, leading to an (implicit) codebook given by the product of these sets. By appropriately choosing the number of dimensions and values each dimension can take, we obtain the same codebook size as in VQ. On top of such discrete representations, we can train the same models that have been trained on VQ-VAE representations. For example, autoregressive and masked transformer models for image generation, multimodal generation, and dense prediction computer vision tasks. Concretely, we employ FSQ with MaskGIT for image generation, and with UViM for depth estimation, colorization, and panoptic segmentation. Despite the much simpler design of FSQ, we obtain competitive performance in all these tasks. We emphasize that FSQ does not suffer from codebook collapse and does not need the complex machinery employed in VQ (commitment losses, codebook reseeding, code splitting, entropy penalties, etc.) to learn expressive discrete representations.
[ "Fabian Mentzer", "David Minnen", "Eirikur Agustsson", "Michael Tschannen" ]
2023-09-27 09:13:40
http://arxiv.org/abs/2309.15505v2
http://arxiv.org/pdf/2309.15505v2
2309.15505v2
Bayesian Personalized Federated Learning with Shared and Personalized Uncertainty Representations
Bayesian personalized federated learning (BPFL) addresses challenges in existing personalized FL (PFL). BPFL aims to quantify the uncertainty and heterogeneity within and across clients towards uncertainty representations by addressing the statistical heterogeneity of client data. In PFL, some recent preliminary work proposes to decompose hidden neural representations into shared and local components and demonstrates interesting results. However, most of them do not address client uncertainty and heterogeneity in FL systems, while appropriately decoupling neural representations is challenging and often ad hoc. In this paper, we make the first attempt to introduce a general BPFL framework to decompose and jointly learn shared and personalized uncertainty representations on statistically heterogeneous client data over time. A Bayesian federated neural network BPFed instantiates BPFL by jointly learning cross-client shared uncertainty and client-specific personalized uncertainty over statistically heterogeneous and randomly participating clients. We further involve continual updating of prior distribution in BPFed to speed up the convergence and avoid catastrophic forgetting. Theoretical analysis and guarantees are provided in addition to the experimental evaluation of BPFed against the diversified baselines.
[ "Hui Chen", "Hengyu Liu", "Longbing Cao", "Tiancheng Zhang" ]
2023-09-27 08:52:08
http://arxiv.org/abs/2309.15499v2
http://arxiv.org/pdf/2309.15499v2
2309.15499v2
Explainable machine learning-based prediction model for diabetic nephropathy
The aim of this study is to analyze the effect of serum metabolites on diabetic nephropathy (DN) and predict the prevalence of DN through a machine learning approach. The dataset consists of 548 patients from April 2018 to April 2019 in Second Affiliated Hospital of Dalian Medical University (SAHDMU). We select the optimal 38 features through a Least absolute shrinkage and selection operator (LASSO) regression model and a 10-fold cross-validation. We compare four machine learning algorithms, including eXtreme Gradient Boosting (XGB), random forest, decision tree and logistic regression, by AUC-ROC curves, decision curves, calibration curves. We quantify feature importance and interaction effects in the optimal predictive model by Shapley Additive exPlanations (SHAP) method. The XGB model has the best performance to screen for DN with the highest AUC value of 0.966. The XGB model also gains more clinical net benefits than others and the fitting degree is better. In addition, there are significant interactions between serum metabolites and duration of diabetes. We develop a predictive model by XGB algorithm to screen for DN. C2, C5DC, Tyr, Ser, Met, C24, C4DC, and Cys have great contribution in the model, and can possibly be biomarkers for DN.
[ "Jing-Mei Yin", "Yang Li", "Jun-Tang Xue", "Guo-Wei Zong", "Zhong-Ze Fang", "Lang Zou" ]
2023-09-27 08:46:57
http://arxiv.org/abs/2309.16730v1
http://arxiv.org/pdf/2309.16730v1
2309.16730v1
Fast Locality Sensitive Hashing with Theoretical Guarantee
Locality-sensitive hashing (LSH) is an effective randomized technique widely used in many machine learning tasks. The cost of hashing is proportional to data dimensions, and thus often the performance bottleneck when dimensionality is high and the number of hash functions involved is large. Surprisingly, however, little work has been done to improve the efficiency of LSH computation. In this paper, we design a simple yet efficient LSH scheme, named FastLSH, under l2 norm. By combining random sampling and random projection, FastLSH reduces the time complexity from O(n) to O(m) (m<n), where n is the data dimensionality and m is the number of sampled dimensions. Moreover, FastLSH has provable LSH property, which distinguishes it from the non-LSH fast sketches. We conduct comprehensive experiments over a collection of real and synthetic datasets for the nearest neighbor search task. Experimental results demonstrate that FastLSH is on par with the state-of-the-arts in terms of answer quality, space occupation and query efficiency, while enjoying up to 80x speedup in hash function evaluation. We believe that FastLSH is a promising alternative to the classic LSH scheme.
[ "Zongyuan Tan", "Hongya Wang", "Bo Xu", "Minjie Luo", "Ming Du" ]
2023-09-27 08:21:38
http://arxiv.org/abs/2309.15479v1
http://arxiv.org/pdf/2309.15479v1
2309.15479v1
The Robust Semantic Segmentation UNCV2023 Challenge Results
This paper outlines the winning solutions employed in addressing the MUAD uncertainty quantification challenge held at ICCV 2023. The challenge was centered around semantic segmentation in urban environments, with a particular focus on natural adversarial scenarios. The report presents the results of 19 submitted entries, with numerous techniques drawing inspiration from cutting-edge uncertainty quantification methodologies presented at prominent conferences in the fields of computer vision and machine learning and journals over the past few years. Within this document, the challenge is introduced, shedding light on its purpose and objectives, which primarily revolved around enhancing the robustness of semantic segmentation in urban scenes under varying natural adversarial conditions. The report then delves into the top-performing solutions. Moreover, the document aims to provide a comprehensive overview of the diverse solutions deployed by all participants. By doing so, it seeks to offer readers a deeper insight into the array of strategies that can be leveraged to effectively handle the inherent uncertainties associated with autonomous driving and semantic segmentation, especially within urban environments.
[ "Xuanlong Yu", "Yi Zuo", "Zitao Wang", "Xiaowen Zhang", "Jiaxuan Zhao", "Yuting Yang", "Licheng Jiao", "Rui Peng", "Xinyi Wang", "Junpei Zhang", "Kexin Zhang", "Fang Liu", "Roberto Alcover-Couso", "Juan C. SanMiguel", "Marcos Escudero-Viñolo", "Hanlin Tian", "Kenta Matsui", "Tianhao Wang", "Fahmy Adan", "Zhitong Gao", "Xuming He", "Quentin Bouniot", "Hossein Moghaddam", "Shyam Nandan Rai", "Fabio Cermelli", "Carlo Masone", "Andrea Pilzer", "Elisa Ricci", "Andrei Bursuc", "Arno Solin", "Martin Trapp", "Rui Li", "Angela Yao", "Wenlong Chen", "Ivor Simpson", "Neill D. F. Campbell", "Gianni Franchi" ]
2023-09-27 08:20:03
http://arxiv.org/abs/2309.15478v1
http://arxiv.org/pdf/2309.15478v1
2309.15478v1
Enabling Resource-efficient AIoT System with Cross-level Optimization: A survey
The emerging field of artificial intelligence of things (AIoT, AI+IoT) is driven by the widespread use of intelligent infrastructures and the impressive success of deep learning (DL). With the deployment of DL on various intelligent infrastructures featuring rich sensors and weak DL computing capabilities, a diverse range of AIoT applications has become possible. However, DL models are notoriously resource-intensive. Existing research strives to realize near-/realtime inference of AIoT live data and low-cost training using AIoT datasets on resource-scare infrastructures. Accordingly, the accuracy and responsiveness of DL models are bounded by resource availability. To this end, the algorithm-system co-design that jointly optimizes the resource-friendly DL models and model-adaptive system scheduling improves the runtime resource availability and thus pushes the performance boundary set by the standalone level. Unlike previous surveys on resource-friendly DL models or hand-crafted DL compilers/frameworks with partially fine-tuned components, this survey aims to provide a broader optimization space for more free resource-performance tradeoffs. The cross-level optimization landscape involves various granularity, including the DL model, computation graph, operator, memory schedule, and hardware instructor in both on-device and distributed paradigms. Furthermore, due to the dynamic nature of AIoT context, which includes heterogeneous hardware, agnostic sensing data, varying user-specified performance demands, and resource constraints, this survey explores the context-aware inter-/intra-device controllers for automatic cross-level adaptation. Additionally, we identify some potential directions for resource-efficient AIoT systems. By consolidating problems and techniques scattered over diverse levels, we aim to help readers understand their connections and stimulate further discussions.
[ "Sicong Liu", "Bin Guo", "Cheng Fang", "Ziqi Wang", "Shiyan Luo", "Zimu Zhou", "Zhiwen Yu" ]
2023-09-27 08:04:24
http://arxiv.org/abs/2309.15467v1
http://arxiv.org/pdf/2309.15467v1
2309.15467v1
DTC: Deep Tracking Control -- A Unifying Approach to Model-Based Planning and Reinforcement-Learning for Versatile and Robust Locomotion
Legged locomotion is a complex control problem that requires both accuracy and robustness to cope with real-world challenges. Legged systems have traditionally been controlled using trajectory optimization with inverse dynamics. Such hierarchical model-based methods are appealing due to intuitive cost function tuning, accurate planning, and most importantly, the insightful understanding gained from more than one decade of extensive research. However, model mismatch and violation of assumptions are common sources of faulty operation and may hinder successful sim-to-real transfer. Simulation-based reinforcement learning, on the other hand, results in locomotion policies with unprecedented robustness and recovery skills. Yet, all learning algorithms struggle with sparse rewards emerging from environments where valid footholds are rare, such as gaps or stepping stones. In this work, we propose a hybrid control architecture that combines the advantages of both worlds to simultaneously achieve greater robustness, foot-placement accuracy, and terrain generalization. Our approach utilizes a model-based planner to roll out a reference motion during training. A deep neural network policy is trained in simulation, aiming to track the optimized footholds. We evaluate the accuracy of our locomotion pipeline on sparse terrains, where pure data-driven methods are prone to fail. Furthermore, we demonstrate superior robustness in the presence of slippery or deformable ground when compared to model-based counterparts. Finally, we show that our proposed tracking controller generalizes across different trajectory optimization methods not seen during training. In conclusion, our work unites the predictive capabilities and optimality guarantees of online planning with the inherent robustness attributed to offline learning.
[ "Fabian Jenelten", "Junzhe He", "Farbod Farshidian", "Marco Hutter" ]
2023-09-27 07:57:37
http://arxiv.org/abs/2309.15462v1
http://arxiv.org/pdf/2309.15462v1
2309.15462v1
SimPINNs: Simulation-Driven Physics-Informed Neural Networks for Enhanced Performance in Nonlinear Inverse Problems
This paper introduces a novel approach to solve inverse problems by leveraging deep learning techniques. The objective is to infer unknown parameters that govern a physical system based on observed data. We focus on scenarios where the underlying forward model demonstrates pronounced nonlinear behaviour, and where the dimensionality of the unknown parameter space is substantially smaller than that of the observations. Our proposed method builds upon physics-informed neural networks (PINNs) trained with a hybrid loss function that combines observed data with simulated data generated by a known (approximate) physical model. Experimental results on an orbit restitution problem demonstrate that our approach surpasses the performance of standard PINNs, providing improved accuracy and robustness.
[ "Sidney Besnard", "Frédéric Jurie", "Jalal M. Fadili" ]
2023-09-27 06:34:55
http://arxiv.org/abs/2309.16729v1
http://arxiv.org/pdf/2309.16729v1
2309.16729v1
Graph Neural Prompting with Large Language Models
Large Language Models (LLMs) have shown remarkable generalization capability with exceptional performance in various language modeling tasks. However, they still exhibit inherent limitations in precisely capturing and returning grounded knowledge. While existing work has explored utilizing knowledge graphs to enhance language modeling via joint training and customized model architectures, applying this to LLMs is problematic owing to their large number of parameters and high computational cost. In addition, how to leverage the pre-trained LLMs and avoid training a customized model from scratch remains an open question. In this work, we propose Graph Neural Prompting (GNP), a novel plug-and-play method to assist pre-trained LLMs in learning beneficial knowledge from KGs. GNP encompasses various designs, including a standard graph neural network encoder, a cross-modality pooling module, a domain projector, and a self-supervised link prediction objective. Extensive experiments on multiple datasets demonstrate the superiority of GNP on both commonsense and biomedical reasoning tasks across different LLM sizes and settings.
[ "Yijun Tian", "Huan Song", "Zichen Wang", "Haozhu Wang", "Ziqing Hu", "Fang Wang", "Nitesh V. Chawla", "Panpan Xu" ]
2023-09-27 06:33:29
http://arxiv.org/abs/2309.15427v1
http://arxiv.org/pdf/2309.15427v1
2309.15427v1
NeuRBF: A Neural Fields Representation with Adaptive Radial Basis Functions
We present a novel type of neural fields that uses general radial bases for signal representation. State-of-the-art neural fields typically rely on grid-based representations for storing local neural features and N-dimensional linear kernels for interpolating features at continuous query points. The spatial positions of their neural features are fixed on grid nodes and cannot well adapt to target signals. Our method instead builds upon general radial bases with flexible kernel position and shape, which have higher spatial adaptivity and can more closely fit target signals. To further improve the channel-wise capacity of radial basis functions, we propose to compose them with multi-frequency sinusoid functions. This technique extends a radial basis to multiple Fourier radial bases of different frequency bands without requiring extra parameters, facilitating the representation of details. Moreover, by marrying adaptive radial bases with grid-based ones, our hybrid combination inherits both adaptivity and interpolation smoothness. We carefully designed weighting schemes to let radial bases adapt to different types of signals effectively. Our experiments on 2D image and 3D signed distance field representation demonstrate the higher accuracy and compactness of our method than prior arts. When applied to neural radiance field reconstruction, our method achieves state-of-the-art rendering quality, with small model size and comparable training speed.
[ "Zhang Chen", "Zhong Li", "Liangchen Song", "Lele Chen", "Jingyi Yu", "Junsong Yuan", "Yi Xu" ]
2023-09-27 06:32:05
http://arxiv.org/abs/2309.15426v1
http://arxiv.org/pdf/2309.15426v1
2309.15426v1
Deep Learning in Deterministic Computational Mechanics
The rapid growth of deep learning research, including within the field of computational mechanics, has resulted in an extensive and diverse body of literature. To help researchers identify key concepts and promising methodologies within this field, we provide an overview of deep learning in deterministic computational mechanics. Five main categories are identified and explored: simulation substitution, simulation enhancement, discretizations as neural networks, generative approaches, and deep reinforcement learning. This review focuses on deep learning methods rather than applications for computational mechanics, thereby enabling researchers to explore this field more effectively. As such, the review is not necessarily aimed at researchers with extensive knowledge of deep learning -- instead, the primary audience is researchers at the verge of entering this field or those who attempt to gain an overview of deep learning in computational mechanics. The discussed concepts are, therefore, explained as simple as possible.
[ "Leon Herrmann", "Stefan Kollmannsberger" ]
2023-09-27 05:57:19
http://arxiv.org/abs/2309.15421v1
http://arxiv.org/pdf/2309.15421v1
2309.15421v1
The Triad of Failure Modes and a Possible Way Out
We present a novel objective function for cluster-based self-supervised learning (SSL) that is designed to circumvent the triad of failure modes, namely representation collapse, cluster collapse, and the problem of invariance to permutations of cluster assignments. This objective consists of three key components: (i) A generative term that penalizes representation collapse, (ii) a term that promotes invariance to data augmentations, thereby addressing the issue of label permutations and (ii) a uniformity term that penalizes cluster collapse. Additionally, our proposed objective possesses two notable advantages. Firstly, it can be interpreted from a Bayesian perspective as a lower bound on the data log-likelihood. Secondly, it enables the training of a standard backbone architecture without the need for asymmetric elements like stop gradients, momentum encoders, or specialized clustering layers. Due to its simplicity and theoretical foundation, our proposed objective is well-suited for optimization. Experiments on both toy and real world data demonstrate its effectiveness
[ "Emanuele Sansone" ]
2023-09-27 05:54:14
http://arxiv.org/abs/2309.15420v1
http://arxiv.org/pdf/2309.15420v1
2309.15420v1
Neuro-Inspired Hierarchical Multimodal Learning
Integrating and processing information from various sources or modalities are critical for obtaining a comprehensive and accurate perception of the real world. Drawing inspiration from neuroscience, we develop the Information-Theoretic Hierarchical Perception (ITHP) model, which utilizes the concept of information bottleneck. Distinct from most traditional fusion models that aim to incorporate all modalities as input, our model designates the prime modality as input, while the remaining modalities act as detectors in the information pathway. Our proposed perception model focuses on constructing an effective and compact information flow by achieving a balance between the minimization of mutual information between the latent state and the input modal state, and the maximization of mutual information between the latent states and the remaining modal states. This approach leads to compact latent state representations that retain relevant information while minimizing redundancy, thereby substantially enhancing the performance of downstream tasks. Experimental evaluations on both the MUStARD and CMU-MOSI datasets demonstrate that our model consistently distills crucial information in multimodal learning scenarios, outperforming state-of-the-art benchmarks.
[ "Xiongye Xiao", "Gengshuo Liu", "Gaurav Gupta", "Defu Cao", "Shixuan Li", "Yaxing Li", "Tianqing Fang", "Mingxi Cheng", "Paul Bogdan" ]
2023-09-27 05:50:05
http://arxiv.org/abs/2309.15877v1
http://arxiv.org/pdf/2309.15877v1
2309.15877v1
Automatic Feature Fairness in Recommendation via Adversaries
Fairness is a widely discussed topic in recommender systems, but its practical implementation faces challenges in defining sensitive features while maintaining recommendation accuracy. We propose feature fairness as the foundation to achieve equitable treatment across diverse groups defined by various feature combinations. This improves overall accuracy through balanced feature generalizability. We introduce unbiased feature learning through adversarial training, using adversarial perturbation to enhance feature representation. The adversaries improve model generalization for under-represented features. We adapt adversaries automatically based on two forms of feature biases: frequency and combination variety of feature values. This allows us to dynamically adjust perturbation strengths and adversarial training weights. Stronger perturbations are applied to feature values with fewer combination varieties to improve generalization, while higher weights for low-frequency features address training imbalances. We leverage the Adaptive Adversarial perturbation based on the widely-applied Factorization Machine (AAFM) as our backbone model. In experiments, AAFM surpasses strong baselines in both fairness and accuracy measures. AAFM excels in providing item- and user-fairness for single- and multi-feature tasks, showcasing their versatility and scalability. To maintain good accuracy, we find that adversarial perturbation must be well-managed: during training, perturbations should not overly persist and their strengths should decay.
[ "Hengchang Hu", "Yiming Cao", "Zhankui He", "Samson Tan", "Min-Yen Kan" ]
2023-09-27 05:48:05
http://arxiv.org/abs/2309.15418v1
http://arxiv.org/pdf/2309.15418v1
2309.15418v1
STAG: Enabling Low Latency and Low Staleness of GNN-based Services with Dynamic Graphs
Many emerging user-facing services adopt Graph Neural Networks (GNNs) to improve serving accuracy. When the graph used by a GNN model changes, representations (embedding) of nodes in the graph should be updated accordingly. However, the node representation update is too slow, resulting in either long response latency of user queries (the inference is performed after the update completes) or high staleness problem (the inference is performed based on stale data). Our in-depth analysis shows that the slow update is mainly due to neighbor explosion problem in graphs and duplicated computation. Based on such findings, we propose STAG, a GNN serving framework that enables low latency and low staleness of GNN-based services. It comprises a collaborative serving mechanism and an additivity-based incremental propagation strategy. With the collaborative serving mechanism, only part of node representations are updated during the update phase, and the final representations are calculated in the inference phase. It alleviates the neighbor explosion problem. The additivity-based incremental propagation strategy reuses intermediate data during the update phase, eliminating duplicated computation problem. Experimental results show that STAG accelerates the update phase by 1.3x~90.1x, and greatly reduces staleness time with a slight increase in response latency.
[ "Jiawen Wang", "Quan Chen", "Deze Zeng", "Zhuo Song", "Chen Chen", "Minyi Guo" ]
2023-09-27 05:15:02
http://arxiv.org/abs/2309.15875v1
http://arxiv.org/pdf/2309.15875v1
2309.15875v1
Revolutionizing Terrain-Precipitation Understanding through AI-driven Knowledge Discovery
Advancing our understanding of climate processes in regions characterized by intricate terrain complexity is a paramount challenge in contemporary climate science, particularly in the context of global climate change. Notably, the scarcity of observational data in these regions has imposed substantial limitations on understanding the nuanced climate dynamics therein. For the first time, utilizing cutting-edge AI-driven knowledge discovery techniques, we have uncovered explicit equations that elucidate the intricate relationship between terrain features and precipitation patterns, illuminating the previously concealed complexities governing these relationships. These equations, thus far undisclosed, exhibit remarkable accuracy compared to conventional empirical models when applied to precipitation data. Building on this foundation, we reveal a phenomenon known as the '1995 turning point,' indicating a significant shift in the terrain-precipitation relationship in approximately 1995, related to the forces of climate change. These equations have practical applications, particularly in achieving fine-scale downscaling precipitation predictions from low-resolution future climate data. This capability provides invaluable insights into the expected changes in precipitation patterns across diverse terrains under future climate scenarios.
[ "Hao Xu", "Yuntian Chen", "Zhenzhong Zeng", "Nina Li", "Jian Li", "Dongxiao Zhang" ]
2023-09-27 04:47:22
http://arxiv.org/abs/2309.15400v1
http://arxiv.org/pdf/2309.15400v1
2309.15400v1
Model-Free, Regret-Optimal Best Policy Identification in Online CMDPs
This paper considers the best policy identification (BPI) problem in online Constrained Markov Decision Processes (CMDPs). We are interested in algorithms that are model-free, have low regret, and identify an optimal policy with a high probability. Existing model-free algorithms for online CMDPs with sublinear regret and constraint violation do not provide any convergence guarantee to an optimal policy and provide only average performance guarantees when a policy is uniformly sampled at random from all previously used policies. In this paper, we develop a new algorithm, named Pruning-Refinement-Identification (PRI), based on a fundamental structural property of CMDPs proved in Koole(1988); Ross(1989), which we call limited stochasticity. The property says for a CMDP with $N$ constraints, there exists an optimal policy with at most $N$ stochastic decisions. The proposed algorithm first identifies at which step and in which state a stochastic decision has to be taken and then fine-tunes the distributions of these stochastic decisions. PRI achieves trio objectives: (i) PRI is a model-free algorithm; and (ii) it outputs a near-optimal policy with a high probability at the end of learning; and (iii) in the tabular setting, PRI guarantees $\tilde{\mathcal{O}}(\sqrt{K})$ regret and constraint violation, which significantly improves the best existing regret bound $\tilde{\mathcal{O}}(K^{\frac{4}{5}})$ under a model-free algorithm, where $K$ is the total number of episodes.
[ "Zihan Zhou", "Honghao Wei", "Lei Ying" ]
2023-09-27 04:33:09
http://arxiv.org/abs/2309.15395v3
http://arxiv.org/pdf/2309.15395v3
2309.15395v3
Neural Stochastic Differential Equations for Robust and Explainable Analysis of Electromagnetic Unintended Radiated Emissions
We present a comprehensive evaluation of the robustness and explainability of ResNet-like models in the context of Unintended Radiated Emission (URE) classification and suggest a new approach leveraging Neural Stochastic Differential Equations (SDEs) to address identified limitations. We provide an empirical demonstration of the fragility of ResNet-like models to Gaussian noise perturbations, where the model performance deteriorates sharply and its F1-score drops to near insignificance at 0.008 with a Gaussian noise of only 0.5 standard deviation. We also highlight a concerning discrepancy where the explanations provided by ResNet-like models do not reflect the inherent periodicity in the input data, a crucial attribute in URE detection from stable devices. In response to these findings, we propose a novel application of Neural SDEs to build models for URE classification that are not only robust to noise but also provide more meaningful and intuitive explanations. Neural SDE models maintain a high F1-score of 0.93 even when exposed to Gaussian noise with a standard deviation of 0.5, demonstrating superior resilience to ResNet models. Neural SDE models successfully recover the time-invariant or periodic horizontal bands from the input data, a feature that was conspicuously missing in the explanations generated by ResNet-like models. This advancement presents a small but significant step in the development of robust and interpretable models for real-world URE applications where data is inherently noisy and assurance arguments demand interpretable machine learning predictions.
[ "Sumit Kumar Jha", "Susmit Jha", "Rickard Ewetz", "Alvaro Velasquez" ]
2023-09-27 03:37:16
http://arxiv.org/abs/2309.15386v1
http://arxiv.org/pdf/2309.15386v1
2309.15386v1
ADGym: Design Choices for Deep Anomaly Detection
Deep learning (DL) techniques have recently been applied to anomaly detection (AD), yielding successful outcomes in areas such as finance, medical services, and cloud computing. However, much of the current research evaluates a deep AD algorithm holistically, failing to understand the contributions of individual design choices like loss functions and network architectures. Consequently, the importance of prerequisite steps, such as preprocessing, might be overshadowed by the spotlight on novel loss functions and architectures. In this paper, we address these oversights by posing two questions: (i) Which components (i.e., design choices) of deep AD methods are pivotal in detecting anomalies? (ii) How can we construct tailored AD algorithms for specific datasets by selecting the best design choices automatically, rather than relying on generic, pre-existing solutions? To this end, we introduce ADGym, the first platform designed for comprehensive evaluation and automatic selection of AD design elements in deep methods. Extensive experiments reveal that merely adopting existing leading methods is not ideal. Models crafted using ADGym markedly surpass current state-of-the-art techniques.
[ "Minqi Jiang", "Chaochuan Hou", "Ao Zheng", "Songqiao Han", "Hailiang Huang", "Qingsong Wen", "Xiyang Hu", "Yue Zhao" ]
2023-09-27 03:10:32
http://arxiv.org/abs/2309.15376v1
http://arxiv.org/pdf/2309.15376v1
2309.15376v1
PPG to ECG Signal Translation for Continuous Atrial Fibrillation Detection via Attention-based Deep State-Space Modeling
An electrocardiogram (ECG or EKG) is a medical test that measures the heart's electrical activity. ECGs are often used to diagnose and monitor a wide range of heart conditions, including arrhythmias, heart attacks, and heart failure. On the one hand, the conventional ECG requires clinical measurement, which restricts its deployment to medical facilities. On the other hand, single-lead ECG has become popular on wearable devices using administered procedures. An alternative to ECG is Photoplethysmography (PPG), which uses non-invasive, low-cost optical methods to measure cardiac physiology, making it a suitable option for capturing vital heart signs in daily life. As a result, it has become increasingly popular in health monitoring and is used in various clinical and commercial wearable devices. While ECG and PPG correlate strongly, the latter does not offer significant clinical diagnostic value. Here, we propose a subject-independent attention-based deep state-space model to translate PPG signals to corresponding ECG waveforms. The model is highly data-efficient by incorporating prior knowledge in terms of probabilistic graphical models. Notably, the model enables the detection of atrial fibrillation (AFib), the most common heart rhythm disorder in adults, by complementing ECG's accuracy with continuous PPG monitoring. We evaluated the model on 55 subjects from the MIMIC III database. Quantitative and qualitative experimental results demonstrate the effectiveness and efficiency of our approach.
[ "Khuong Vo", "Mostafa El-Khamy", "Yoojin Choi" ]
2023-09-27 03:07:46
http://arxiv.org/abs/2309.15375v1
http://arxiv.org/pdf/2309.15375v1
2309.15375v1
Density Estimation via Measure Transport: Outlook for Applications in the Biological Sciences
One among several advantages of measure transport methods is that they allow for a unified framework for processing and analysis of data distributed according to a wide class of probability measures. Within this context, we present results from computational studies aimed at assessing the potential of measure transport techniques, specifically, the use of triangular transport maps, as part of a workflow intended to support research in the biological sciences. Scarce data scenarios, which are common in domains such as radiation biology, are of particular interest. We find that when data is scarce, sparse transport maps are advantageous. In particular, statistics gathered from computing series of (sparse) adaptive transport maps, trained on a series of randomly chosen subsets of the set of available data samples, leads to uncovering information hidden in the data. As a result, in the radiation biology application considered here, this approach provides a tool for generating hypotheses about gene relationships and their dynamics under radiation exposure.
[ "Vanessa Lopez-Marrero", "Patrick R. Johnstone", "Gilchan Park", "Xihaier Luo" ]
2023-09-27 02:36:42
http://arxiv.org/abs/2309.15366v1
http://arxiv.org/pdf/2309.15366v1
2309.15366v1
C3Net: interatomic potential neural network for prediction of physicochemical properties in heterogenous systems
Understanding the interactions of a solute with its environment is of fundamental importance in chemistry and biology. In this work, we propose a deep neural network architecture for atom type embeddings in its molecular context and interatomic potential that follows fundamental physical laws. The architecture is applied to predict physicochemical properties in heterogeneous systems including solvation in diverse solvents, 1-octanol-water partitioning, and PAMPA with a single set of network weights. We show that our architecture is generalized well to the physicochemical properties and outperforms state-of-the-art approaches based on quantum mechanics and neural networks in the task of solvation free energy prediction. The interatomic potentials at each atom in a solute obtained from the model allow quantitative analysis of the physicochemical properties at atomic resolution consistent with chemical and physical reasoning. The software is available at https://github.com/SehanLee/C3Net.
[ "Sehan Lee", "Jaechang Lim", "Woo Youn Kim" ]
2023-09-27 00:51:24
http://arxiv.org/abs/2309.15334v1
http://arxiv.org/pdf/2309.15334v1
2309.15334v1
Exploring Learned Representations of Neural Networks with Principal Component Analysis
Understanding feature representation for deep neural networks (DNNs) remains an open question within the general field of explainable AI. We use principal component analysis (PCA) to study the performance of a k-nearest neighbors classifier (k-NN), nearest class-centers classifier (NCC), and support vector machines on the learned layer-wise representations of a ResNet-18 trained on CIFAR-10. We show that in certain layers, as little as 20% of the intermediate feature-space variance is necessary for high-accuracy classification and that across all layers, the first ~100 PCs completely determine the performance of the k-NN and NCC classifiers. We relate our findings to neural collapse and provide partial evidence for the related phenomenon of intermediate neural collapse. Our preliminary work provides three distinct yet interpretable surrogate models for feature representation with an affine linear model the best performing. We also show that leveraging several surrogate models affords us a clever method to estimate where neural collapse may initially occur within the DNN.
[ "Amit Harlev", "Andrew Engel", "Panos Stinis", "Tony Chiang" ]
2023-09-27 00:18:25
http://arxiv.org/abs/2309.15328v1
http://arxiv.org/pdf/2309.15328v1
2309.15328v1
Neural Operators for Accelerating Scientific Simulations and Design
Scientific discovery and engineering design are currently limited by the time and cost of physical experiments, selected mostly through trial-and-error and intuition that require deep domain expertise. Numerical simulations present an alternative to physical experiments but are usually infeasible for complex real-world domains due to the computational requirements of existing numerical methods. Artificial intelligence (AI) presents a potential paradigm shift by developing fast data-driven surrogate models. In particular, an AI framework, known as neural operators, presents a principled framework for learning mappings between functions defined on continuous domains, e.g., spatiotemporal processes and partial differential equations (PDE). They can extrapolate and predict solutions at new locations unseen during training, i.e., perform zero-shot super-resolution. Neural operators can augment or even replace existing simulators in many applications, such as computational fluid dynamics, weather forecasting, and material modeling, while being 4-5 orders of magnitude faster. Further, neural operators can be integrated with physics and other domain constraints enforced at finer resolutions to obtain high-fidelity solutions and good generalization. Since neural operators are differentiable, they can directly optimize parameters for inverse design and other inverse problems. We believe that neural operators present a transformative approach to simulation and design, enabling rapid research and development.
[ "Kamyar Azizzadenesheli", "Nikola Kovachki", "Zongyi Li", "Miguel Liu-Schiaffini", "Jean Kossaifi", "Anima Anandkumar" ]
2023-09-27 00:12:07
http://arxiv.org/abs/2309.15325v3
http://arxiv.org/pdf/2309.15325v3
2309.15325v3
On the Power of SVD in the Stochastic Block Model
A popular heuristic method for improving clustering results is to apply dimensionality reduction before running clustering algorithms. It has been observed that spectral-based dimensionality reduction tools, such as PCA or SVD, improve the performance of clustering algorithms in many applications. This phenomenon indicates that spectral method not only serves as a dimensionality reduction tool, but also contributes to the clustering procedure in some sense. It is an interesting question to understand the behavior of spectral steps in clustering problems. As an initial step in this direction, this paper studies the power of vanilla-SVD algorithm in the stochastic block model (SBM). We show that, in the symmetric setting, vanilla-SVD algorithm recovers all clusters correctly. This result answers an open question posed by Van Vu (Combinatorics Probability and Computing, 2018) in the symmetric setting.
[ "Xinyu Mao", "Jiapeng Zhang" ]
2023-09-27 00:04:27
http://arxiv.org/abs/2309.15322v1
http://arxiv.org/pdf/2309.15322v1
2309.15322v1
DeepROCK: Error-controlled interaction detection in deep neural networks
The complexity of deep neural networks (DNNs) makes them powerful but also makes them challenging to interpret, hindering their applicability in error-intolerant domains. Existing methods attempt to reason about the internal mechanism of DNNs by identifying feature interactions that influence prediction outcomes. However, such methods typically lack a systematic strategy to prioritize interactions while controlling confidence levels, making them difficult to apply in practice for scientific discovery and hypothesis validation. In this paper, we introduce a method, called DeepROCK, to address this limitation by using knockoffs, which are dummy variables that are designed to mimic the dependence structure of a given set of features while being conditionally independent of the response. Together with a novel DNN architecture involving a pairwise-coupling layer, DeepROCK jointly controls the false discovery rate (FDR) and maximizes statistical power. In addition, we identify a challenge in correctly controlling FDR using off-the-shelf feature interaction importance measures. DeepROCK overcomes this challenge by proposing a calibration procedure applied to existing interaction importance measures to make the FDR under control at a target level. Finally, we validate the effectiveness of DeepROCK through extensive experiments on simulated and real datasets.
[ "Winston Chen", "William Stafford Noble", "Yang Young Lu" ]
2023-09-26 23:58:19
http://arxiv.org/abs/2309.15319v1
http://arxiv.org/pdf/2309.15319v1
2309.15319v1
MAPTree: Beating "Optimal" Decision Trees with Bayesian Decision Trees
Decision trees remain one of the most popular machine learning models today, largely due to their out-of-the-box performance and interpretability. In this work, we present a Bayesian approach to decision tree induction via maximum a posteriori inference of a posterior distribution over trees. We first demonstrate a connection between maximum a posteriori inference of decision trees and AND/OR search. Using this connection, we propose an AND/OR search algorithm, dubbed MAPTree, which is able to recover the maximum a posteriori tree. Lastly, we demonstrate the empirical performance of the maximum a posteriori tree both on synthetic data and in real world settings. On 16 real world datasets, MAPTree either outperforms baselines or demonstrates comparable performance but with much smaller trees. On a synthetic dataset, MAPTree also demonstrates greater robustness to noise and better generalization than existing approaches. Finally, MAPTree recovers the maxiumum a posteriori tree faster than existing sampling approaches and, in contrast with those algorithms, is able to provide a certificate of optimality. The code for our experiments is available at https://github.com/ThrunGroup/maptree.
[ "Colin Sullivan", "Mo Tiwari", "Sebastian Thrun" ]
2023-09-26 23:43:37
http://arxiv.org/abs/2309.15312v2
http://arxiv.org/pdf/2309.15312v2
2309.15312v2
STERLING: Self-Supervised Terrain Representation Learning from Unconstrained Robot Experience
Terrain awareness, i.e., the ability to identify and distinguish different types of terrain, is a critical ability that robots must have to succeed at autonomous off-road navigation. Current approaches that provide robots with this awareness either rely on labeled data which is expensive to collect, engineered features and cost functions that may not generalize, or expert human demonstrations which may not be available. Towards endowing robots with terrain awareness without these limitations, we introduce Self-supervised TErrain Representation LearnING (STERLING), a novel approach for learning terrain representations that relies solely on easy-to-collect, unconstrained (e.g., non-expert), and unlabelled robot experience, with no additional constraints on data collection. STERLING employs a novel multi-modal self-supervision objective through non-contrastive representation learning to learn relevant terrain representations for terrain-aware navigation. Through physical robot experiments in off-road environments, we evaluate STERLING features on the task of preference-aligned visual navigation and find that STERLING features perform on par with fully supervised approaches and outperform other state-of-the-art methods with respect to preference alignment. Additionally, we perform a large-scale experiment of autonomously hiking a 3-mile long trail which STERLING completes successfully with only two manual interventions, demonstrating its robustness to real-world off-road conditions.
[ "Haresh Karnan", "Elvin Yang", "Daniel Farkash", "Garrett Warnell", "Joydeep Biswas", "Peter Stone" ]
2023-09-26 22:55:32
http://arxiv.org/abs/2309.15302v2
http://arxiv.org/pdf/2309.15302v2
2309.15302v2
Telescope: An Automated Hybrid Forecasting Approach on a Level-Playing Field
In many areas of decision-making, forecasting is an essential pillar. Consequently, many different forecasting methods have been proposed. From our experience, recently presented forecasting methods are computationally intensive, poorly automated, tailored to a particular data set, or they lack a predictable time-to-result. To this end, we introduce Telescope, a novel machine learning-based forecasting approach that automatically retrieves relevant information from a given time series and splits it into parts, handling each of them separately. In contrast to deep learning methods, our approach doesn't require parameterization or the need to train and fit a multitude of parameters. It operates with just one time series and provides forecasts within seconds without any additional setup. Our experiments show that Telescope outperforms recent methods by providing accurate and reliable forecasts while making no assumptions about the analyzed time series.
[ "André Bauer", "Mark Leznik", "Michael Stenger", "Robert Leppich", "Nikolas Herbst", "Samuel Kounev", "Ian Foster" ]
2023-09-26 22:42:25
http://arxiv.org/abs/2309.15871v1
http://arxiv.org/pdf/2309.15871v1
2309.15871v1
Beyond Log-Concavity: Theory and Algorithm for Sum-Log-Concave Optimization
This paper extends the classic theory of convex optimization to the minimization of functions that are equal to the negated logarithm of what we term as a sum-log-concave function, i.e., a sum of log-concave functions. In particular, we show that such functions are in general not convex but still satisfy generalized convexity inequalities. These inequalities unveil the key importance of a certain vector that we call the cross-gradient and that is, in general, distinct from the usual gradient. Thus, we propose the Cross Gradient Descent (XGD) algorithm moving in the opposite direction of the cross-gradient and derive a convergence analysis. As an application of our sum-log-concave framework, we introduce the so-called checkered regression method relying on a sum-log-concave function. This classifier extends (multiclass) logistic regression to non-linearly separable problems since it is capable of tessellating the feature space by using any given number of hyperplanes, creating a checkerboard-like pattern of decision regions.
[ "Mastane Achab" ]
2023-09-26 22:22:45
http://arxiv.org/abs/2309.15298v1
http://arxiv.org/pdf/2309.15298v1
2309.15298v1
Multiple Case Physics-Informed Neural Network for Biomedical Tube Flows
Fluid dynamics computations for tube-like geometries are important for biomedical evaluation of vascular and airway fluid dynamics. Physics-Informed Neural Networks (PINNs) have recently emerged as a good alternative to traditional computational fluid dynamics (CFD) methods. The vanilla PINN, however, requires much longer training time than the traditional CFD methods for each specific flow scenario and thus does not justify its mainstream use. Here, we explore the use of the multi-case PINN approach for calculating biomedical tube flows, where varied geometry cases are parameterized and pre-trained on the PINN, such that results for unseen geometries can be obtained in real time. Our objective is to identify network architecture, tube-specific, and regularization strategies that can optimize this, via experiments on a series of idealized 2D stenotic tube flows.
[ "Hong Shen Wong", "Wei Xuan Chan", "Bing Huan Li", "Choon Hwai Yap" ]
2023-09-26 22:15:49
http://arxiv.org/abs/2309.15294v2
http://arxiv.org/pdf/2309.15294v2
2309.15294v2
Maximum Diffusion Reinforcement Learning
The assumption that data are independent and identically distributed underpins all machine learning. When data are collected sequentially from agent experiences this assumption does not generally hold, as in reinforcement learning. Here, we derive a method that overcomes these limitations by exploiting the statistical mechanics of ergodic processes, which we term maximum diffusion reinforcement learning. By decorrelating agent experiences, our approach provably enables agents to learn continually in single-shot deployments regardless of how they are initialized. Moreover, we prove our approach generalizes well-known maximum entropy techniques, and show that it robustly exceeds state-of-the-art performance across popular benchmarks. Our results at the nexus of physics, learning, and control pave the way towards more transparent and reliable decision-making in reinforcement learning agents, such as locomoting robots and self-driving cars.
[ "Thomas A. Berrueta", "Allison Pinosky", "Todd D. Murphey" ]
2023-09-26 22:14:56
http://arxiv.org/abs/2309.15293v2
http://arxiv.org/pdf/2309.15293v2
2309.15293v2
Scaling Representation Learning from Ubiquitous ECG with State-Space Models
Ubiquitous sensing from wearable devices in the wild holds promise for enhancing human well-being, from diagnosing clinical conditions and measuring stress to building adaptive health promoting scaffolds. But the large volumes of data therein across heterogeneous contexts pose challenges for conventional supervised learning approaches. Representation Learning from biological signals is an emerging realm catalyzed by the recent advances in computational modeling and the abundance of publicly shared databases. The electrocardiogram (ECG) is the primary researched modality in this context, with applications in health monitoring, stress and affect estimation. Yet, most studies are limited by small-scale controlled data collection and over-parameterized architecture choices. We introduce \textbf{WildECG}, a pre-trained state-space model for representation learning from ECG signals. We train this model in a self-supervised manner with 275,000 10s ECG recordings collected in the wild and evaluate it on a range of downstream tasks. The proposed model is a robust backbone for ECG analysis, providing competitive performance on most of the tasks considered, while demonstrating efficacy in low-resource regimes. The code and pre-trained weights are shared publicly at https://github.com/klean2050/tiles_ecg_model.
[ "Kleanthis Avramidis", "Dominika Kunc", "Bartosz Perz", "Kranti Adsul", "Tiantian Feng", "Przemysław Kazienko", "Stanisław Saganowski", "Shrikanth Narayanan" ]
2023-09-26 22:08:19
http://arxiv.org/abs/2309.15292v1
http://arxiv.org/pdf/2309.15292v1
2309.15292v1
SEPT: Towards Efficient Scene Representation Learning for Motion Prediction
Motion prediction is crucial for autonomous vehicles to operate safely in complex traffic environments. Extracting effective spatiotemporal relationships among traffic elements is key to accurate forecasting. Inspired by the successful practice of pretrained large language models, this paper presents SEPT, a modeling framework that leverages self-supervised learning to develop powerful spatiotemporal understanding for complex traffic scenes. Specifically, our approach involves three masking-reconstruction modeling tasks on scene inputs including agents' trajectories and road network, pretraining the scene encoder to capture kinematics within trajectory, spatial structure of road network, and interactions among roads and agents. The pretrained encoder is then finetuned on the downstream forecasting task. Extensive experiments demonstrate that SEPT, without elaborate architectural design or manual feature engineering, achieves state-of-the-art performance on the Argoverse 1 and Argoverse 2 motion forecasting benchmarks, outperforming previous methods on all main metrics by a large margin.
[ "Zhiqian Lan", "Yuxuan Jiang", "Yao Mu", "Chen Chen", "Shengbo Eben Li", "Hang Zhao", "Keqiang Li" ]
2023-09-26 21:56:03
http://arxiv.org/abs/2309.15289v3
http://arxiv.org/pdf/2309.15289v3
2309.15289v3
Composable Coresets for Determinant Maximization: Greedy is Almost Optimal
Given a set of $n$ vectors in $\mathbb{R}^d$, the goal of the \emph{determinant maximization} problem is to pick $k$ vectors with the maximum volume. Determinant maximization is the MAP-inference task for determinantal point processes (DPP) and has recently received considerable attention for modeling diversity. As most applications for the problem use large amounts of data, this problem has been studied in the relevant \textit{composable coreset} setting. In particular, [Indyk-Mahabadi-OveisGharan-Rezaei--SODA'20, ICML'19] showed that one can get composable coresets with optimal approximation factor of $\tilde O(k)^k$ for the problem, and that a local search algorithm achieves an almost optimal approximation guarantee of $O(k)^{2k}$. In this work, we show that the widely-used Greedy algorithm also provides composable coresets with an almost optimal approximation factor of $O(k)^{3k}$, which improves over the previously known guarantee of $C^{k^2}$, and supports the prior experimental results showing the practicality of the greedy algorithm as a coreset. Our main result follows by showing a local optimality property for Greedy: swapping a single point from the greedy solution with a vector that was not picked by the greedy algorithm can increase the volume by a factor of at most $(1+\sqrt{k})$. This is tight up to the additive constant $1$. Finally, our experiments show that the local optimality of the greedy algorithm is even lower than the theoretical bound on real data sets.
[ "Siddharth Gollapudi", "Sepideh Mahabadi", "Varun Sivashankar" ]
2023-09-26 21:46:44
http://arxiv.org/abs/2309.15286v1
http://arxiv.org/pdf/2309.15286v1
2309.15286v1
A Physics Enhanced Residual Learning (PERL) Framework for Traffic State Prediction
In vehicle trajectory prediction, physics models and data-driven models are two predominant methodologies. However, each approach presents its own set of challenges: physics models fall short in predictability, while data-driven models lack interpretability. Addressing these identified shortcomings, this paper proposes a novel framework, the Physics-Enhanced Residual Learning (PERL) model. PERL integrates the strengths of physics-based and data-driven methods for traffic state prediction. PERL contains a physics model and a residual learning model. Its prediction is the sum of the physics model result and a predicted residual as a correction to it. It preserves the interpretability inherent to physics-based models and has reduced data requirements compared to data-driven methods. Experiments were conducted using a real-world vehicle trajectory dataset. We proposed a PERL model, with the Intelligent Driver Model (IDM) as its physics car-following model and Long Short-Term Memory (LSTM) as its residual learning model. We compare this PERL model with the physics car-following model, data-driven model, and other physics-informed neural network (PINN) models. The result reveals that PERL achieves better prediction with a small dataset, compared to the physics model, data-driven model, and PINN model. Second, the PERL model showed faster convergence during training, offering comparable performance with fewer training samples than the data-driven model and PINN model. Sensitivity analysis also proves comparable performance of PERL using another residual learning model and a physics car-following model.
[ "Keke Long", "Haotian Shi", "Zihao Sheng", "Xiaopeng Li", "Sikai Chen" ]
2023-09-26 21:41:45
http://arxiv.org/abs/2309.15284v1
http://arxiv.org/pdf/2309.15284v1
2309.15284v1
Out of Sight, Still in Mind: Reasoning and Planning about Unobserved Objects with Video Tracking Enabled Memory Models
Robots need to have a memory of previously observed, but currently occluded objects to work reliably in realistic environments. We investigate the problem of encoding object-oriented memory into a multi-object manipulation reasoning and planning framework. We propose DOOM and LOOM, which leverage transformer relational dynamics to encode the history of trajectories given partial-view point clouds and an object discovery and tracking engine. Our approaches can perform multiple challenging tasks including reasoning with occluded objects, novel objects appearance, and object reappearance. Throughout our extensive simulation and real-world experiments, we find that our approaches perform well in terms of different numbers of objects and different numbers of distractor actions. Furthermore, we show our approaches outperform an implicit memory baseline.
[ "Yixuan Huang", "Jialin Yuan", "Chanho Kim", "Pupul Pradhan", "Bryan Chen", "Li Fuxin", "Tucker Hermans" ]
2023-09-26 21:31:24
http://arxiv.org/abs/2309.15278v1
http://arxiv.org/pdf/2309.15278v1
2309.15278v1
Efficient Low-rank Backpropagation for Vision Transformer Adaptation
The increasing scale of vision transformers (ViT) has made the efficient fine-tuning of these large models for specific needs a significant challenge in various applications. This issue originates from the computationally demanding matrix multiplications required during the backpropagation process through linear layers in ViT. In this paper, we tackle this problem by proposing a new Low-rank BackPropagation via Walsh-Hadamard Transformation (LBP-WHT) method. Intuitively, LBP-WHT projects the gradient into a low-rank space and carries out backpropagation. This approach substantially reduces the computation needed for adapting ViT, as matrix multiplication in the low-rank space is far less resource-intensive. We conduct extensive experiments with different models (ViT, hybrid convolution-ViT model) on multiple datasets to demonstrate the effectiveness of our method. For instance, when adapting an EfficientFormer-L1 model on CIFAR100, our LBP-WHT achieves 10.4% higher accuracy than the state-of-the-art baseline, while requiring 9 MFLOPs less computation. As the first work to accelerate ViT adaptation with low-rank backpropagation, our LBP-WHT method is complementary to many prior efforts and can be combined with them for better performance.
[ "Yuedong Yang", "Hung-Yueh Chiang", "Guihong Li", "Diana Marculescu", "Radu Marculescu" ]
2023-09-26 21:27:55
http://arxiv.org/abs/2309.15275v1
http://arxiv.org/pdf/2309.15275v1
2309.15275v1
Identifying factors associated with fast visual field progression in patients with ocular hypertension based on unsupervised machine learning
Purpose: To identify ocular hypertension (OHT) subtypes with different trends of visual field (VF) progression based on unsupervised machine learning and to discover factors associated with fast VF progression. Participants: A total of 3133 eyes of 1568 ocular hypertension treatment study (OHTS) participants with at least five follow-up VF tests were included in the study. Methods: We used a latent class mixed model (LCMM) to identify OHT subtypes using standard automated perimetry (SAP) mean deviation (MD) trajectories. We characterized the subtypes based on demographic, clinical, ocular, and VF factors at the baseline. We then identified factors driving fast VF progression using generalized estimating equation (GEE) and justified findings qualitatively and quantitatively. Results: The LCMM model discovered four clusters (subtypes) of eyes with different trajectories of MD worsening. The number of eyes in clusters were 794 (25%), 1675 (54%), 531 (17%) and 133 (4%). We labelled the clusters as Improvers, Stables, Slow progressors, and Fast progressors based on their mean of MD decline, which were 0.08, -0.06, -0.21, and -0.45 dB/year, respectively. Eyes with fast VF progression had higher baseline age, intraocular pressure (IOP), pattern standard deviation (PSD) and refractive error (RE), but lower central corneal thickness (CCT). Fast progression was associated with calcium channel blockers, being male, heart disease history, diabetes history, African American race, stroke history, and migraine headaches.
[ "Xiaoqin Huang", "Asma Poursoroush", "Jian Sun", "Michael V. Boland", "Chris Johnson", "Siamak Yousefi" ]
2023-09-26 20:46:40
http://arxiv.org/abs/2309.15867v1
http://arxiv.org/pdf/2309.15867v1
2309.15867v1
STARC: A General Framework For Quantifying Differences Between Reward Functions
In order to solve a task using reinforcement learning, it is necessary to first formalise the goal of that task as a reward function. However, for many real-world tasks, it is very difficult to manually specify a reward function that never incentivises undesirable behaviour. As a result, it is increasingly popular to use reward learning algorithms, which attempt to learn a reward function from data. However, the theoretical foundations of reward learning are not yet well-developed. In particular, it is typically not known when a given reward learning algorithm with high probability will learn a reward function that is safe to optimise. This means that reward learning algorithms generally must be evaluated empirically, which is expensive, and that their failure modes are difficult to predict in advance. One of the roadblocks to deriving better theoretical guarantees is the lack of good methods for quantifying the difference between reward functions. In this paper we provide a solution to this problem, in the form of a class of pseudometrics on the space of all reward functions that we call STARC (STAndardised Reward Comparison) metrics. We show that STARC metrics induce both an upper and a lower bound on worst-case regret, which implies that our metrics are tight, and that any metric with the same properties must be bilipschitz equivalent to ours. Moreover, we also identify a number of issues with reward metrics proposed by earlier works. Finally, we evaluate our metrics empirically, to demonstrate their practical efficacy. STARC metrics can be used to make both theoretical and empirical analysis of reward learning algorithms both easier and more principled.
[ "Joar Skalse", "Lucy Farnik", "Sumeet Ramesh Motwani", "Erik Jenner", "Adam Gleave", "Alessandro Abate" ]
2023-09-26 20:31:19
http://arxiv.org/abs/2309.15257v1
http://arxiv.org/pdf/2309.15257v1
2309.15257v1
Method and Validation for Optimal Lineup Creation for Daily Fantasy Football Using Machine Learning and Linear Programming
Daily fantasy sports (DFS) are weekly or daily online contests where real-game performances of individual players are converted to fantasy points (FPTS). Users select players for their lineup to maximize their FPTS within a set player salary cap. This paper focuses on (1) the development of a method to forecast NFL player performance under uncertainty and (2) determining an optimal lineup to maximize FPTS under a set salary limit. A supervised learning neural network was created and used to project FPTS based on past player performance (2018 NFL regular season for this work) prior to the upcoming week. These projected FPTS were used in a mixed integer linear program to find the optimal lineup. The performance of resultant lineups was compared to randomly-created lineups. On average, the optimal lineups outperformed the random lineups. The generated lineups were then compared to real-world lineups from users on DraftKings. The generated lineups generally fell in approximately the 31st percentile (median). The FPTS methods and predictions presented here can be further improved using this study as a baseline comparison.
[ "Joseph M. Mahoney", "Tomasz B. Paniak" ]
2023-09-26 20:26:32
http://arxiv.org/abs/2309.15253v2
http://arxiv.org/pdf/2309.15253v2
2309.15253v2
V2X-Lead: LiDAR-based End-to-End Autonomous Driving with Vehicle-to-Everything Communication Integration
This paper presents a LiDAR-based end-to-end autonomous driving method with Vehicle-to-Everything (V2X) communication integration, termed V2X-Lead, to address the challenges of navigating unregulated urban scenarios under mixed-autonomy traffic conditions. The proposed method aims to handle imperfect partial observations by fusing the onboard LiDAR sensor and V2X communication data. A model-free and off-policy deep reinforcement learning (DRL) algorithm is employed to train the driving agent, which incorporates a carefully designed reward function and multi-task learning technique to enhance generalization across diverse driving tasks and scenarios. Experimental results demonstrate the effectiveness of the proposed approach in improving safety and efficiency in the task of traversing unsignalized intersections in mixed-autonomy traffic, and its generalizability to previously unseen scenarios, such as roundabouts. The integration of V2X communication offers a significant data source for autonomous vehicles (AVs) to perceive their surroundings beyond onboard sensors, resulting in a more accurate and comprehensive perception of the driving environment and more safe and robust driving behavior.
[ "Zhiyun Deng", "Yanjun Shi", "Weiming Shen" ]
2023-09-26 20:26:03
http://arxiv.org/abs/2309.15252v1
http://arxiv.org/pdf/2309.15252v1
2309.15252v1
SeMAnD: Self-Supervised Anomaly Detection in Multimodal Geospatial Datasets
We propose a Self-supervised Anomaly Detection technique, called SeMAnD, to detect geometric anomalies in Multimodal geospatial datasets. Geospatial data comprises of acquired and derived heterogeneous data modalities that we transform to semantically meaningful, image-like tensors to address the challenges of representation, alignment, and fusion of multimodal data. SeMAnD is comprised of (i) a simple data augmentation strategy, called RandPolyAugment, capable of generating diverse augmentations of vector geometries, and (ii) a self-supervised training objective with three components that incentivize learning representations of multimodal data that are discriminative to local changes in one modality which are not corroborated by the other modalities. Detecting local defects is crucial for geospatial anomaly detection where even small anomalies (e.g., shifted, incorrectly connected, malformed, or missing polygonal vector geometries like roads, buildings, landcover, etc.) are detrimental to the experience and safety of users of geospatial applications like mapping, routing, search, and recommendation systems. Our empirical study on test sets of different types of real-world geometric geospatial anomalies across 3 diverse geographical regions demonstrates that SeMAnD is able to detect real-world defects and outperforms domain-agnostic anomaly detection strategies by 4.8-19.7% as measured using anomaly classification AUC. We also show that model performance increases (i) up to 20.4% as the number of input modalities increase and (ii) up to 22.9% as the diversity and strength of training data augmentations increase.
[ "Daria Reshetova", "Swetava Ganguli", "C. V. Krishnakumar Iyer", "Vipul Pandey" ]
2023-09-26 20:18:31
http://arxiv.org/abs/2309.15245v1
http://arxiv.org/pdf/2309.15245v1
2309.15245v1
Homotopy Relaxation Training Algorithms for Infinite-Width Two-Layer ReLU Neural Networks
In this paper, we present a novel training approach called the Homotopy Relaxation Training Algorithm (HRTA), aimed at accelerating the training process in contrast to traditional methods. Our algorithm incorporates two key mechanisms: one involves building a homotopy activation function that seamlessly connects the linear activation function with the ReLU activation function; the other technique entails relaxing the homotopy parameter to enhance the training refinement process. We have conducted an in-depth analysis of this novel method within the context of the neural tangent kernel (NTK), revealing significantly improved convergence rates. Our experimental results, especially when considering networks with larger widths, validate the theoretical conclusions. This proposed HRTA exhibits the potential for other activation functions and deep neural networks.
[ "Yahong Yang", "Qipin Chen", "Wenrui Hao" ]
2023-09-26 20:18:09
http://arxiv.org/abs/2309.15244v1
http://arxiv.org/pdf/2309.15244v1
2309.15244v1
Learning Using Generated Privileged Information by Text-to-Image Diffusion Models
Learning Using Privileged Information is a particular type of knowledge distillation where the teacher model benefits from an additional data representation during training, called privileged information, improving the student model, which does not see the extra representation. However, privileged information is rarely available in practice. To this end, we propose a text classification framework that harnesses text-to-image diffusion models to generate artificial privileged information. The generated images and the original text samples are further used to train multimodal teacher models based on state-of-the-art transformer-based architectures. Finally, the knowledge from multimodal teachers is distilled into a text-based (unimodal) student. Hence, by employing a generative model to produce synthetic data as privileged information, we guide the training of the student model. Our framework, called Learning Using Generated Privileged Information (LUGPI), yields noticeable performance gains on four text classification data sets, demonstrating its potential in text classification without any additional cost during inference.
[ "Rafael-Edy Menadil", "Mariana-Iuliana Georgescu", "Radu Tudor Ionescu" ]
2023-09-26 20:04:48
http://arxiv.org/abs/2309.15238v1
http://arxiv.org/pdf/2309.15238v1
2309.15238v1
Cross-Validation for Training and Testing Co-occurrence Network Inference Algorithms
Microorganisms are found in almost every environment, including the soil, water, air, and inside other organisms, like animals and plants. While some microorganisms cause diseases, most of them help in biological processes such as decomposition, fermentation and nutrient cycling. A lot of research has gone into studying microbial communities in various environments and how their interactions and relationships can provide insights into various diseases. Co-occurrence network inference algorithms help us understand the complex associations of micro-organisms, especially bacteria. Existing network inference algorithms employ techniques such as correlation, regularized linear regression, and conditional dependence, which have different hyper-parameters that determine the sparsity of the network. Previous methods for evaluating the quality of the inferred network include using external data, and network consistency across sub-samples, both which have several drawbacks that limit their applicability in real microbiome composition data sets. We propose a novel cross-validation method to evaluate co-occurrence network inference algorithms, and new methods for applying existing algorithms to predict on test data. Our empirical study shows that the proposed method is useful for hyper-parameter selection (training) and comparing the quality of the inferred networks between different algorithms (testing).
[ "Daniel Agyapong", "Jeffrey Ryan Propster", "Jane Marks", "Toby Dylan Hocking" ]
2023-09-26 19:43:15
http://arxiv.org/abs/2309.15225v1
http://arxiv.org/pdf/2309.15225v1
2309.15225v1
Collaborative Watermarking for Adversarial Speech Synthesis
Advances in neural speech synthesis have brought us technology that is not only close to human naturalness, but is also capable of instant voice cloning with little data, and is highly accessible with pre-trained models available. Naturally, the potential flood of generated content raises the need for synthetic speech detection and watermarking. Recently, considerable research effort in synthetic speech detection has been related to the Automatic Speaker Verification and Spoofing Countermeasure Challenge (ASVspoof), which focuses on passive countermeasures. This paper takes a complementary view to generated speech detection: a synthesis system should make an active effort to watermark the generated speech in a way that aids detection by another machine, but remains transparent to a human listener. We propose a collaborative training scheme for synthetic speech watermarking and show that a HiFi-GAN neural vocoder collaborating with the ASVspoof 2021 baseline countermeasure models consistently improves detection performance over conventional classifier training. Furthermore, we demonstrate how collaborative training can be paired with augmentation strategies for added robustness against noise and time-stretching. Finally, listening tests demonstrate that collaborative training has little adverse effect on perceptual quality of vocoded speech.
[ "Lauri Juvela", "Xin Wang" ]
2023-09-26 19:43:14
http://arxiv.org/abs/2309.15224v1
http://arxiv.org/pdf/2309.15224v1
2309.15224v1
Low-rank Adaptation of Large Language Model Rescoring for Parameter-Efficient Speech Recognition
We propose a neural language modeling system based on low-rank adaptation (LoRA) for speech recognition output rescoring. Although pretrained language models (LMs) like BERT have shown superior performance in second-pass rescoring, the high computational cost of scaling up the pretraining stage and adapting the pretrained models to specific domains limit their practical use in rescoring. Here we present a method based on low-rank decomposition to train a rescoring BERT model and adapt it to new domains using only a fraction (0.08%) of the pretrained parameters. These inserted matrices are optimized through a discriminative training objective along with a correlation-based regularization loss. The proposed low-rank adaptation Rescore-BERT (LoRB) architecture is evaluated on LibriSpeech and internal datasets with decreased training times by factors between 5.4 and 3.6.
[ "Yu Yu", "Chao-Han Huck Yang", "Jari Kolehmainen", "Prashanth G. Shivakumar", "Yile Gu", "Sungho Ryu", "Roger Ren", "Qi Luo", "Aditya Gourav", "I-Fan Chen", "Yi-Chieh Liu", "Tuan Dinh", "Ankur Gandhe", "Denis Filimonov", "Shalini Ghosh", "Andreas Stolcke", "Ariya Rastow", "Ivan Bulyko" ]
2023-09-26 19:41:34
http://arxiv.org/abs/2309.15223v2
http://arxiv.org/pdf/2309.15223v2
2309.15223v2
Auto-grading C programming assignments with CodeBERT and Random Forest Regressor
Grading coding assignments manually is challenging due to complexity and subjectivity. However, auto-grading with deep learning simplifies the task. It objectively assesses code quality, detects errors, and assigns marks accurately, reducing the burden on instructors while ensuring efficient and fair assessment. This study provides an analysis of auto-grading of the C programming assignments using machine learning and deep learning approaches like regression, convolutional neural networks (CNN) and long short-term memory (LSTM). Using a code-based transformer word embedding model called CodeBERT, the textual code inputs were transformed into vectors, and the vectors were then fed into several models. The testing findings demonstrated the efficacy of the suggested strategy with a root mean squared error (RMSE) of 1.89. The contrast between statistical methods and deep learning techniques is discussed in the study.
[ "Roshan Vasu Muddaluru", "Sharvaani Ravikumar Thoguluva", "Shruti Prabha", "Dr. Peeta Basa Pati", "Ms. Roshni M Balakrishnan" ]
2023-09-26 19:21:09
http://arxiv.org/abs/2309.15216v1
http://arxiv.org/pdf/2309.15216v1
2309.15216v1
Balancing Computational Efficiency and Forecast Error in Machine Learning-based Time-Series Forecasting: Insights from Live Experiments on Meteorological Nowcasting
Machine learning for time-series forecasting remains a key area of research. Despite successful application of many machine learning techniques, relating computational efficiency to forecast error remains an under-explored domain. This paper addresses this topic through a series of real-time experiments to quantify the relationship between computational cost and forecast error using meteorological nowcasting as an example use-case. We employ a variety of popular regression techniques (XGBoost, FC-MLP, Transformer, and LSTM) for multi-horizon, short-term forecasting of three variables (temperature, wind speed, and cloud cover) for multiple locations. During a 5-day live experiment, 4000 data sources were streamed for training and inferencing 144 models per hour. These models were parameterized to explore forecast error for two computational cost minimization methods: a novel auto-adaptive data reduction technique (Variance Horizon) and a performance-based concept drift-detection mechanism. Forecast error of all model variations were benchmarked in real-time against a state-of-the-art numerical weather prediction model. Performance was assessed using classical and novel evaluation metrics. Results indicate that using the Variance Horizon reduced computational usage by more than 50\%, while increasing between 0-15\% in error. Meanwhile, performance-based retraining reduced computational usage by up to 90\% while \emph{also} improving forecast error by up to 10\%. Finally, the combination of both the Variance Horizon and performance-based retraining outperformed other model configurations by up to 99.7\% when considering error normalized to computational usage.
[ "Elin Törnquist", "Wagner Costa Santos", "Timothy Pogue", "Nicholas Wingle", "Robert A. Caulk" ]
2023-09-26 19:10:00
http://arxiv.org/abs/2309.15207v1
http://arxiv.org/pdf/2309.15207v1
2309.15207v1
ICML 2023 Topological Deep Learning Challenge : Design and Results
This paper presents the computational challenge on topological deep learning that was hosted within the ICML 2023 Workshop on Topology and Geometry in Machine Learning. The competition asked participants to provide open-source implementations of topological neural networks from the literature by contributing to the python packages TopoNetX (data processing) and TopoModelX (deep learning). The challenge attracted twenty-eight qualifying submissions in its two-month duration. This paper describes the design of the challenge and summarizes its main findings.
[ "Mathilde Papillon", "Mustafa Hajij", "Florian Frantzen", "Josef Hoppe", "Helen Jenne", "Johan Mathe", "Audun Myers", "Theodore Papamarkou", "Michael T. Schaub", "Ghada Zamzmi", "Tolga Birdal", "Tamal Dey", "Tim Doster", "Tegan Emerson", "Gurusankar Gopalakrishnan", "Devendra Govil", "Vincent Grande", "Aldo Guzmán-Sáenz", "Henry Kvinge", "Neal Livesay", "Jan Meisner", "Soham Mukherjee", "Shreyas N. Samaga", "Karthikeyan Natesan Ramamurthy", "Maneel Reddy Karri", "Paul Rosen", "Sophia Sanborn", "Michael Scholkemper", "Robin Walters", "Jens Agerberg", "Georg Bökman", "Sadrodin Barikbin", "Claudio Battiloro", "Gleb Bazhenov", "Guillermo Bernardez", "Aiden Brent", "Sergio Escalera", "Simone Fiorellino", "Dmitrii Gavrilev", "Mohammed Hassanin", "Paul Häusner", "Odin Hoff Gardaa", "Abdelwahed Khamis", "Manuel Lecha", "German Magai", "Tatiana Malygina", "Pavlo Melnyk", "Rubén Ballester", "Kalyan Nadimpalli", "Alexander Nikitin", "Abraham Rabinowitz", "Alessandro Salatiello", "Simone Scardapane", "Luca Scofano", "Suraj Singh", "Jens Sjölund", "Pavel Snopov", "Indro Spinelli", "Lev Telyatnikov", "Lucia Testa", "Maosheng Yang", "Yixiao Yue", "Olga Zaghen", "Ali Zia", "Nina Miolane" ]
2023-09-26 18:49:30
http://arxiv.org/abs/2309.15188v2
http://arxiv.org/pdf/2309.15188v2
2309.15188v2
Monitoring Machine Learning Models: Online Detection of Relevant Deviations
Machine learning models are essential tools in various domains, but their performance can degrade over time due to changes in data distribution or other factors. On one hand, detecting and addressing such degradations is crucial for maintaining the models' reliability. On the other hand, given enough data, any arbitrary small change of quality can be detected. As interventions, such as model re-training or replacement, can be expensive, we argue that they should only be carried out when changes exceed a given threshold. We propose a sequential monitoring scheme to detect these relevant changes. The proposed method reduces unnecessary alerts and overcomes the multiple testing problem by accounting for temporal dependence of the measured model quality. Conditions for consistency and specified asymptotic levels are provided. Empirical validation using simulated and real data demonstrates the superiority of our approach in detecting relevant changes in model quality compared to benchmark methods. Our research contributes a practical solution for distinguishing between minor fluctuations and meaningful degradations in machine learning model performance, ensuring their reliability in dynamic environments.
[ "Florian Heinrichs" ]
2023-09-26 18:46:37
http://arxiv.org/abs/2309.15187v1
http://arxiv.org/pdf/2309.15187v1
2309.15187v1
Conservative World Models
Zero-shot reinforcement learning (RL) promises to provide agents that can perform any task in an environment after an offline pre-training phase. Forward-backward (FB) representations represent remarkable progress towards this ideal, achieving 85% of the performance of task-specific agents in this setting. However, such performance is contingent on access to large and diverse datasets for pre-training, which cannot be expected for most real problems. Here, we explore how FB performance degrades when trained on small datasets that lack diversity, and mitigate it with conservatism, a well-established feature of performant offline RL algorithms. We evaluate our family of methods across various datasets, domains and tasks, reaching 150% of vanilla FB performance in aggregate. Somewhat surprisingly, conservative FB algorithms also outperform the task-specific baseline, despite lacking access to reward labels and being required to maintain policies for all tasks. Conservative FB algorithms perform no worse than FB on full datasets, and so present little downside over their predecessor. Our code is available open-source via https://enjeeneer.io/projects/conservative-world-models/.
[ "Scott Jeen", "Tom Bewley", "Jonathan M. Cullen" ]
2023-09-26 18:20:20
http://arxiv.org/abs/2309.15178v1
http://arxiv.org/pdf/2309.15178v1
2309.15178v1
Revealing the Power of Spatial-Temporal Masked Autoencoders in Multivariate Time Series Forecasting
Multivariate time series (MTS) forecasting involves predicting future time series data based on historical observations. Existing research primarily emphasizes the development of complex spatial-temporal models that capture spatial dependencies and temporal correlations among time series variables explicitly. However, recent advances have been impeded by challenges relating to data scarcity and model robustness. To address these issues, we propose Spatial-Temporal Masked Autoencoders (STMAE), an MTS forecasting framework that leverages masked autoencoders to enhance the performance of spatial-temporal baseline models. STMAE consists of two learning stages. In the pretraining stage, an encoder-decoder architecture is employed. The encoder processes the partially visible MTS data produced by a novel dual-masking strategy, including biased random walk-based spatial masking and patch-based temporal masking. Subsequently, the decoders aim to reconstruct the masked counterparts from both spatial and temporal perspectives. The pretraining stage establishes a challenging pretext task, compelling the encoder to learn robust spatial-temporal patterns. In the fine-tuning stage, the pretrained encoder is retained, and the original decoder from existing spatial-temporal models is appended for forecasting. Extensive experiments are conducted on multiple MTS benchmarks. The promising results demonstrate that integrating STMAE into various spatial-temporal models can largely enhance their MTS forecasting capability.
[ "Jiarui Sun", "Yujie Fan", "Chin-Chia Michael Yeh", "Wei Zhang", "Girish Chowdhary" ]
2023-09-26 18:05:19
http://arxiv.org/abs/2309.15169v1
http://arxiv.org/pdf/2309.15169v1
2309.15169v1
SGD Finds then Tunes Features in Two-Layer Neural Networks with near-Optimal Sample Complexity: A Case Study in the XOR problem
In this work, we consider the optimization process of minibatch stochastic gradient descent (SGD) on a 2-layer neural network with data separated by a quadratic ground truth function. We prove that with data drawn from the $d$-dimensional Boolean hypercube labeled by the quadratic ``XOR'' function $y = -x_ix_j$, it is possible to train to a population error $o(1)$ with $d \:\text{polylog}(d)$ samples. Our result considers simultaneously training both layers of the two-layer-neural network with ReLU activations via standard minibatch SGD on the logistic loss. To our knowledge, this work is the first to give a sample complexity of $\tilde{O}(d)$ for efficiently learning the XOR function on isotropic data on a standard neural network with standard training. Our main technique is showing that the network evolves in two phases: a $\textit{signal-finding}$ phase where the network is small and many of the neurons evolve independently to find features, and a $\textit{signal-heavy}$ phase, where SGD maintains and balances the features. We leverage the simultaneous training of the layers to show that it is sufficient for only a small fraction of the neurons to learn features, since those neurons will be amplified by the simultaneous growth of their second layer weights.
[ "Margalit Glasgow" ]
2023-09-26 17:57:44
http://arxiv.org/abs/2309.15111v2
http://arxiv.org/pdf/2309.15111v2
2309.15111v2
Attention Satisfies: A Constraint-Satisfaction Lens on Factual Errors of Language Models
We investigate the internal behavior of Transformer-based Large Language Models (LLMs) when they generate factually incorrect text. We propose modeling factual queries as Constraint Satisfaction Problems and use this framework to investigate how the model interacts internally with factual constraints. Specifically, we discover a strong positive relation between the model's attention to constraint tokens and the factual accuracy of its responses. In our curated suite of 11 datasets with over 40,000 prompts, we study the task of predicting factual errors with the Llama-2 family across all scales (7B, 13B, 70B). We propose SAT Probe, a method probing self-attention patterns, that can predict constraint satisfaction and factual errors, and allows early error identification. The approach and findings demonstrate how using the mechanistic understanding of factuality in LLMs can enhance reliability.
[ "Mert Yuksekgonul", "Varun Chandrasekaran", "Erik Jones", "Suriya Gunasekar", "Ranjita Naik", "Hamid Palangi", "Ece Kamar", "Besmira Nushi" ]
2023-09-26 17:48:55
http://arxiv.org/abs/2309.15098v1
http://arxiv.org/pdf/2309.15098v1
2309.15098v1