South America
Quantum neural network with ensemble learning to mitigate barren plateaus and cost function concentration
Friedrich, Lucas, Maziero, Jonas
The rapid development of quantum computers promises transformative impacts across diverse fields of science and technology. Quantum neural networks (QNNs), as a forefront application, hold substantial potential. Despite the multitude of proposed models in the literature, persistent challenges, notably the vanishing gradient (VG) and cost function concentration (CFC) problems, impede their widespread success. In this study, we introduce a novel approach to quantum neural network construction, specifically addressing the issues of VG and CFC. Our methodology employs ensemble learning, advocating for the simultaneous deployment of multiple quantum circuits with a depth equal to $1$, a departure from the conventional use of a single quantum circuit with depth $L$. We assess the efficacy of our proposed model through a comparative analysis with a conventionally constructed QNN. The evaluation unfolds in the context of a classification problem, yielding valuable insights into the potential advantages of our innovative approach.
Trustful Coopetitive Infrastructures for the New Space Exploration Era
Baima, Renan Lima, Chovet, Loïck, Hartwich, Eduard, Bera, Abhishek, Sedlmeir, Johannes, Fridgen, Gilbert, Olivares-Mendez, Miguel Angel
In the new space economy, space agencies, large enterprises, and start-ups aim to launch space multi-robot systems (MRS) for various in-situ resource utilization (ISRU) purposes, such as mapping, soil evaluation, and utility provisioning. However, these stakeholders' competing economic interests may hinder effective collaboration on a centralized digital platform. To address this issue, neutral and transparent infrastructures could facilitate coordination and value exchange among heterogeneous space MRS. While related work has expressed legitimate concerns about the technical challenges associated with blockchain use in space, we argue that weighing its potential economic benefits against its drawbacks is necessary. This paper presents a novel architectural framework and a comprehensive set of requirements for integrating blockchain technology in MRS, aiming to enhance coordination and data integrity in space exploration missions. We explored distributed ledger technology (DLT) to design a non-proprietary architecture for heterogeneous MRS and validated the prototype in a simulated lunar environment. The analyses of our implementation suggest global ISRU efficiency improvements for map exploration, compared to a corresponding group of individually acting robots, and that fostering a coopetitive environment may provide additional revenue opportunities for stakeholders.
Sparse-VQ Transformer: An FFN-Free Framework with Vector Quantization for Enhanced Time Series Forecasting
Zhao, Yanjun, Zhou, Tian, Chen, Chao, Sun, Liang, Qian, Yi, Jin, Rong
Time series analysis is vital for numerous applications, and transformers have become increasingly prominent in this domain. Leading methods customize the transformer architecture from NLP and CV, utilizing a patching technique to convert continuous signals into segments. Yet, time series data are uniquely challenging due to significant distribution shifts and intrinsic noise levels. To address these two challenges,we introduce the Sparse Vector Quantized FFN-Free Transformer (Sparse-VQ). Our methodology capitalizes on a sparse vector quantization technique coupled with Reverse Instance Normalization (RevIN) to reduce noise impact and capture sufficient statistics for forecasting, serving as an alternative to the Feed-Forward layer (FFN) in the transformer architecture. Our FFN-free approach trims the parameter count, enhancing computational efficiency and reducing overfitting. Through evaluations across ten benchmark datasets, including the newly introduced CAISO dataset, Sparse-VQ surpasses leading models with a 7.84% and 4.17% decrease in MAE for univariate and multivariate time series forecasting, respectively. Moreover, it can be seamlessly integrated with existing transformer-based models to elevate their performance.
Guided Evolution with Binary Discriminators for ML Program Search
Co-Reyes, John D., Miao, Yingjie, Tucker, George, Faust, Aleksandra, Real, Esteban
How to automatically design better machine learning programs is an open problem within AutoML. While evolution has been a popular tool to search for better ML programs, using learning itself to guide the search has been less successful and less understood on harder problems but has the promise to dramatically increase the speed and final performance of the optimization process. We propose guiding evolution with a binary discriminator, trained online to distinguish which program is better given a pair of programs. The discriminator selects better programs without having to perform a costly evaluation and thus speed up the convergence of evolution. Our method can encode a wide variety of ML components including symbolic optimizers, neural architectures, RL loss functions, and symbolic regression equations with the same directed acyclic graph representation. By combining this representation with modern GNNs and an adaptive mutation strategy, we demonstrate our method can speed up evolution across a set of diverse problems including a 3.7x speedup on the symbolic search for ML optimizers and a 4x speedup for RL loss functions.
Unsupervised Discovery of Clinical Disease Signatures Using Probabilistic Independence
Lasko, Thomas A., Still, John M., Li, Thomas Z., Mota, Marco Barbero, Stead, William W., Strobl, Eric V., Landman, Bennett A., Maldonado, Fabien
Insufficiently precise diagnosis of clinical disease is likely responsible for many treatment failures, even for common conditions and treatments. With a large enough dataset, it may be possible to use unsupervised machine learning to define clinical disease patterns more precisely. We present an approach to learning these patterns by using probabilistic independence to disentangle the imprint on the medical record of causal latent sources of disease. We inferred a broad set of 2000 clinical signatures of latent sources from 9195 variables in 269,099 Electronic Health Records. The learned signatures produced better discrimination than the original variables in a lung cancer prediction task unknown to the inference algorithm, predicting 3-year malignancy in patients with no history of cancer before a solitary lung nodule was discovered. More importantly, the signatures' greater explanatory power identified pre-nodule signatures of apparently undiagnosed cancer in many of those patients.
Phonetically rich corpus construction for a low-resourced language
Amadeus, Marcellus, Castañeda, William Alberto Cruz, Lobato, Wilmer, Aquino, Niasche
Speech technologies rely on capturing a speaker's voice variability while obtaining comprehensive language information. Textual prompts and sentence selection methods have been proposed in the literature to comprise such adequate phonetic data, referred to as a phonetically rich \textit{corpus}. However, they are still insufficient for acoustic modeling, especially critical for languages with limited resources. Hence, this paper proposes a novel approach and outlines the methodological aspects required to create a \textit{corpus} with broad phonetic coverage for a low-resourced language, Brazilian Portuguese. Our methodology includes text dataset collection up to a sentence selection algorithm based on triphone distribution. Furthermore, we propose a new phonemic classification according to acoustic-articulatory speech features since the absolute number of distinct triphones, or low-probability triphones, does not guarantee an adequate representation of every possible combination. Using our algorithm, we achieve a 55.8\% higher percentage of distinct triphones -- for samples of similar size -- while the currently available phonetic-rich corpus, CETUC and TTS-Portuguese, 12.6\% and 12.3\% in comparison to a non-phonetically rich dataset.
Hidden in Plain Sight: Undetectable Adversarial Bias Attacks on Vulnerable Patient Populations
Kulkarni, Pranav, Chan, Andrew, Navarathna, Nithya, Chan, Skylar, Yi, Paul H., Parekh, Vishwa S.
The proliferation of artificial intelligence (AI) in radiology has shed light on the risk of deep learning (DL) models exacerbating clinical biases towards vulnerable patient populations. While prior literature has focused on quantifying biases exhibited by trained DL models, demographically targeted adversarial bias attacks on DL models and its implication in the clinical environment remains an underexplored field of research in medical imaging. In this work, we demonstrate that demographically targeted label poisoning attacks can introduce adversarial underdiagnosis bias in DL models and degrade performance on underrepresented groups without impacting overall model performance. Moreover, our results across multiple performance metrics and demographic groups like sex, age, and their intersectional subgroups indicate that a group's vulnerability to undetectable adversarial bias attacks is directly correlated with its representation in the model's training data.
Comprehensive Assessment of Jailbreak Attacks Against LLMs
Chu, Junjie, Liu, Yugeng, Yang, Ziqing, Shen, Xinyue, Backes, Michael, Zhang, Yang
Misuse of the Large Language Models (LLMs) has raised widespread concern. To address this issue, safeguards have been taken to ensure that LLMs align with social ethics. However, recent findings have revealed an unsettling vulnerability bypassing the safeguards of LLMs, known as jailbreak attacks. By applying techniques, such as employing role-playing scenarios, adversarial examples, or subtle subversion of safety objectives as a prompt, LLMs can produce an inappropriate or even harmful response. While researchers have studied several categories of jailbreak attacks, they have done so in isolation. To fill this gap, we present the first large-scale measurement of various jailbreak attack methods. We concentrate on 13 cutting-edge jailbreak methods from four categories, 160 questions from 16 violation categories, and six popular LLMs. Our extensive experimental results demonstrate that the optimized jailbreak prompts consistently achieve the highest attack success rates, as well as exhibit robustness across different LLMs. Some jailbreak prompt datasets, available from the Internet, can also achieve high attack success rates on many LLMs, such as ChatGLM3, GPT-3.5, and PaLM2. Despite the claims from many organizations regarding the coverage of violation categories in their policies, the attack success rates from these categories remain high, indicating the challenges of effectively aligning LLM policies and the ability to counter jailbreak attacks. We also discuss the trade-off between the attack performance and efficiency, as well as show that the transferability of the jailbreak prompts is still viable, becoming an option for black-box models. Overall, our research highlights the necessity of evaluating different jailbreak methods. We hope our study can provide insights for future research on jailbreak attacks and serve as a benchmark tool for evaluating them for practitioners.
Nonparametric Instrumental Variable Regression through Stochastic Approximate Gradients
Peixoto, Caio, Saporito, Yuri, Fonseca, Yuri
Causal inference from observational data presents unique challenges, primarily due to the potential for confounding variables that can affect both outcomes and variables of interest. The unconfoundedness assumption, crucial in this context, posits that all confounding variables are observed and properly accounted for, allowing for an unbiased estimation of causal effects. However, in many real-world scenarios, this assumption is difficult to satisfy. When this is the case, approaches that rely on instrumental variables (IVs) -- quantities that are correlated with the variable of interest (relevance condition), do not affect the outcome in any other way (exclusion condition) and are independent of the unobservable confounders -- offer a way to identify causal effects even when unobserved confounders exist. Moreover, as traditional parametric models often require assumptions about the relationship between variables that may not hold in practice, nonparametric IV (NPIV) models can adapt to the intrinsic structure of the data, allowing for a more nuanced understanding of causal relationships. There has been a recent boost of new algorithms applied to the NPIV estimation problem and its theoretical properties. The challenge is that NPIV estimation is an ill-posed inverse problem (Newey and Powell, 2003; Carrasco et al., 2007; Cavalier, 2011), and recent methods aim to incorporate developments from predictive models, e.g., deep learning, while also accounting for the particular structure of the inverse problem at hand. In this work, we present a novel framework for NPIV estimation that relies on stochastic approximate gradients, allowing it to seamlessly incorporate a variety of machine learning methods, such as those based on Reproducing Kernel Hilbert Space (RKHS) and deep learning. Moreover, we demonstrate, under minimal assumptions, finite sample guarantees for the projected populational risk for both continuous and binary responses.
Deep Learning-based Computational Job Market Analysis: A Survey on Skill Extraction and Classification from Job Postings
Senger, Elena, Zhang, Mike, van der Goot, Rob, Plank, Barbara
Recent years have brought significant advances to Natural Language Processing (NLP), which enabled fast progress in the field of computational job market analysis. Core tasks in this application domain are skill extraction and classification from job postings. Because of its quick growth and its interdisciplinary nature, there is no exhaustive assessment of this emerging field. This survey aims to fill this gap by providing a comprehensive overview of deep learning methodologies, datasets, and terminologies specific to NLP-driven skill extraction and classification. Our comprehensive cataloging of publicly available datasets addresses the lack of consolidated information on dataset creation and characteristics. Finally, the focus on terminology addresses the current lack of consistent definitions for important concepts, such as hard and soft skills, and terms relating to skill extraction and classification.