Instructional Material
Explanations of Classifiers Enhance Medical Image Segmentation via End-to-end Pre-training
Chen, Jiamin, Li, Xuhong, Xu, Yanwu, Du, Mengnan, Xiong, Haoyi
Medical image segmentation aims to identify and locate abnormal structures in medical images, such as chest radiographs, using deep neural networks. These networks require a large number of annotated images with fine-grained masks for the regions of interest, making pre-training strategies based on classification datasets essential for sample efficiency. Based on a large-scale medical image classification dataset, our work collects explanations from well-trained classifiers to generate pseudo labels of segmentation tasks. Specifically, we offer a case study on chest radiographs and train image classifiers on the CheXpert dataset to identify 14 pathological observations in radiology. We then use Integrated Gradients (IG) method to distill and boost the explanations obtained from the classifiers, generating massive diagnosis-oriented localization labels (DoLL). These DoLL-annotated images are used for pre-training the model before fine-tuning it for downstream segmentation tasks, including COVID-19 infectious areas, lungs, heart, and clavicles. Our method outperforms other baselines, showcasing significant advantages in model performance and training efficiency across various segmentation settings.
DAPT: A Dual Attention Framework for Parameter-Efficient Continual Learning of Large Language Models
Zhao, Weixiang, Wang, Shilong, Hu, Yulin, Zhao, Yanyan, Qin, Bing, Zhang, Xuanyu, Yang, Qing, Xu, Dongliang, Che, Wanxiang
The continual learning (CL) ability is vital for deploying large language models (LLMs) in the dynamic world. Based on parameter-efficient tuning (PET), existing methods devise the learning module and the selection module to handle the challenges of catastrophic forgetting (CF) and knowledge transfer (KT) in CL. The learning module allocates separate PET blocks for each continually emerged task and the selection module function to choose the correct one for the input at testing time. However, there are limitations in their deigns of both modules and they ignore the potential of aligning the two module to address CF and KT simultaneously. To this end, we propose a novel Dual Attention Framework , to align the PET learning and selection via the Dual Attentive Learning\&Selection module. Extensive Experiments on two CL benchmarks demonstrate the superiority of DAPT to resist CF and facilitate KT at the same time. Moreover, DAPT exhibits the superiority when we scale it to different model sizes (from 770M to 11B) and unseen tasks.
Fast Kernel Summation in High Dimensions via Slicing and Fourier Transforms
Kernel-based methods are heavily used in machine learning. However, they suffer from $O(N^2)$ complexity in the number $N$ of considered data points. In this paper, we propose an approximation procedure, which reduces this complexity to $O(N)$. Our approach is based on two ideas. First, we prove that any radial kernel with analytic basis function can be represented as sliced version of some one-dimensional kernel and derive an analytic formula for the one-dimensional counterpart. It turns out that the relation between one- and $d$-dimensional kernels is given by a generalized Riemann-Liouville fractional integral. Hence, we can reduce the $d$-dimensional kernel summation to a one-dimensional setting. Second, for solving these one-dimensional problems efficiently, we apply fast Fourier summations on non-equispaced data, a sorting algorithm or a combination of both. Due to its practical importance we pay special attention to the Gaussian kernel, where we show a dimension-independent error bound and represent its one-dimensional counterpart via a closed-form Fourier transform. We provide a run time comparison and error estimate of our fast kernel summations.
A Generative Adversarial Attack for Multilingual Text Classifiers
Roth, Tom, Unanue, Inigo Jauregi, Abuadbba, Alsharif, Piccardi, Massimo
Current adversarial attack algorithms, where an adversary changes a text to fool a victim model, have been repeatedly shown to be effective against text classifiers. These attacks, however, generally assume that the victim model is monolingual and cannot be used to target multilingual victim models, a significant limitation given the increased use of these models. For this reason, in this work we propose an approach to fine-tune a multilingual paraphrase model with an adversarial objective so that it becomes able to generate effective adversarial examples against multilingual classifiers. The training objective incorporates a set of pre-trained models to ensure text quality and language consistency of the generated text. In addition, all the models are suitably connected to the generator by vocabulary-mapping matrices, allowing for full end-to-end differentiability of the overall training pipeline. The experimental validation over two multilingual datasets and five languages has shown the effectiveness of the proposed approach compared to existing baselines, particularly in terms of query efficiency. We also provide a detailed analysis of the generated attacks and discuss limitations and opportunities for future research.
Human Feedback is not Gold Standard
Hosking, Tom, Blunsom, Phil, Bartolo, Max
Human feedback has become the de facto standard for evaluating the performance of Large Language Models, and is increasingly being used as a training objective. However, it is not clear which properties of a generated output this single `preference' score captures. We hypothesise that preference scores are subjective and open to undesirable biases. We critically analyse the use of human feedback for both training and evaluation, to verify whether it fully captures a range of crucial error criteria. We find that while preference scores have fairly good coverage, they under-represent important aspects like factuality. We further hypothesise that both preference scores and error annotation may be affected by confounders, and leverage instruction-tuned models to generate outputs that vary along two possible confounding dimensions: assertiveness and complexity. We find that the assertiveness of an output skews the perceived rate of factuality errors, indicating that human annotations are not a fully reliable evaluation metric or training objective. Finally, we offer preliminary evidence that using human feedback as a training objective disproportionately increases the assertiveness of model outputs. We encourage future work to carefully consider whether preference scores are well aligned with the desired objective.
We and AI free online course "Living with AI" is back โ tell your friends!
The second run of a five-week free course for anyone on AI starts on the 15th January 2023. We and AI were delighted to work with The Scottish AI Alliance designing content for their course designed to give the general public of Scotland (and beyond!) an introduction to the world of AI. "Living with AI" is a great and rare commitment to making general level AI literacy attainable to everyone to enable a greater understanding of the uses and questions posed by the range of tools and technologies, and to explore their future potential. Although creating materials was challenging due to the rapid changes and innovation, proliferating hype and platform restrictions, feedback from the first run of the course shows how worthwhile the effort was. Each week has a specific topic and the course is made up of written articles, videos from AI experts across Scotland, audio clips, reflective and activity-based exercises, quizzes and opportunities to collaborate with other learners. All content has been refreshed for 2024 and will be released at once, so learners can go at their own pace in their own time.
How does self-supervised pretraining improve robustness against noisy labels across various medical image classification datasets?
Khanal, Bidur, Bhattarai, Binod, Khanal, Bishesh, Linte, Cristian
Noisy labels can significantly impact medical image classification, particularly in deep learning, by corrupting learned features. Self-supervised pretraining, which doesn't rely on labeled data, can enhance robustness against noisy labels. However, this robustness varies based on factors like the number of classes, dataset complexity, and training size. In medical images, subtle inter-class differences and modality-specific characteristics add complexity. Previous research hasn't comprehensively explored the interplay between self-supervised learning and robustness against noisy labels in medical image classification, considering all these factors. In this study, we address three key questions: i) How does label noise impact various medical image classification datasets? ii) Which types of medical image datasets are more challenging to learn and more affected by label noise? iii) How do different self-supervised pretraining methods enhance robustness across various medical image datasets? Our results show that DermNet, among five datasets (Fetal plane, DermNet, COVID-DU-Ex, MURA, NCT-CRC-HE-100K), is the most challenging but exhibits greater robustness against noisy labels. Additionally, contrastive learning stands out among the eight self-supervised methods as the most effective approach to enhance robustness against noisy labels.
Curriculum for Crowd Counting -- Is it Worthy?
Khan, Muhammad Asif, Menouar, Hamid, Hamila, Ridha
Recent advances in deep learning techniques have achieved remarkable performance in several computer vision problems. A notably intuitive technique called Curriculum Learning (CL) has been introduced recently for training deep learning models. Surprisingly, curriculum learning achieves significantly improved results in some tasks but marginal or no improvement in others. Hence, there is still a debate about its adoption as a standard method to train supervised learning models. In this work, we investigate the impact of curriculum learning in crowd counting using the density estimation method. We performed detailed investigations by conducting 112 experiments using six different CL settings using eight different crowd models. Our experiments show that curriculum learning improves the model learning performance and shortens the convergence time.
GACE: Learning Graph-Based Cross-Page Ads Embedding For Click-Through Rate Prediction
Wang, Haowen, Du, Yuliang, Jin, Congyun, Li, Yujiao, Wang, Yingbo, Sun, Tao, Qin, Piqi, Fan, Cong
Predicting click-through rate (CTR) is the core task of many ads online recommendation systems, which helps improve user experience and increase platform revenue. In this type of recommendation system, we often encounter two main problems: the joint usage of multi-page historical advertising data and the cold start of new ads. In this paper, we proposed GACE, a graph-based cross-page ads embedding generation method. It can warm up and generate the representation embedding of cold-start and existing ads across various pages. Specifically, we carefully build linkages and a weighted undirected graph model considering semantic and page-type attributes to guide the direction of feature fusion and generation. We designed a variational auto-encoding task as pre-training module and generated embedding representations for new and old ads based on this task. The results evaluated in the public dataset AliEC from RecBole and the real-world industry dataset from Alipay show that our GACE method is significantly superior to the SOTA method. In the online A/B test, the click-through rate on three real-world pages from Alipay has increased by 3.6%, 2.13%, and 3.02%, respectively. Especially in the cold-start task, the CTR increased by 9.96%, 7.51%, and 8.97%, respectively.
Get a comprehensive ChatGPT education for just 25
ChatGPT took the world by storm in 2023, and while it hasn't exactly changed work the way some may have thought it would, it's still a useful tool to know. This four-course bundle is taught by leading online instructors Mike Wheeler (4.6/5-star instructor rating), John Elder (4.4/5-star rating), and Alex Genadinik (4.4/5-star rating). They'll give you an introduction to ChatGPT, showing you the basic applications and hacks. From there, you'll also learn how to build your own chatbots powered by ChatGPT and how to use ChatGPT to scale your business. Get familiar with ChatGPT in 2024.