Deep Learning
Finding Holes: Pathologist Level Performance Using AI for Cribriform Morphology Detection in Prostate Cancer
Szolnoky, Kelvin, Blilie, Anders, Mulliqi, Nita, Tsuzuki, Toyonori, Samaratunga, Hemamali, Titus, Matteo, Ji, Xiaoyi, Boman, Sol Erika, Gudlaugsson, Einar, Kjosavik, Svein Reidar, Asenjo, Josรฉ, Gambacorta, Marcello, Libretti, Paolo, Braun, Marcin, Kordek, Radisลaw, ลowicki, Roman, Delahunt, Brett, Iczkowski, Kenneth A., van der Kwast, Theo, van Leenders, Geert J. L. H., Leite, Katia R. M., Pan, Chin-Chen, Janssen, Emiel Adrianus Maria, Eklund, Martin, Egevad, Lars, Kartasalo, Kimmo
Background: Cribriform morphology in prostate cancer is a histological feature that indicates poor prognosis and contraindicates active surveillance. However, it remains underreported and subject to significant interobserver variability amongst pathologists. We aimed to develop and validate an AI-based system to improve cribriform pattern detection. Methods: We created a deep learning model using an EfficientNetV2-S encoder with multiple instance learning for end-to-end whole-slide classification. The model was trained on 640 digitised prostate core needle biopsies from 430 patients, collected across three cohorts. It was validated internally (261 slides from 171 patients) and externally (266 slides, 104 patients from three independent cohorts). Internal validation cohorts included laboratories or scanners from the development set, while external cohorts used completely independent instruments and laboratories. Annotations were provided by three expert uropathologists with known high concordance. Additionally, we conducted an inter-rater analysis and compared the model's performance against nine expert uropathologists on 88 slides from the internal validation cohort. Results: The model showed strong internal validation performance (AUC: 0.97, 95% CI: 0.95-0.99; Cohen's kappa: 0.81, 95% CI: 0.72-0.89) and robust external validation (AUC: 0.90, 95% CI: 0.86-0.93; Cohen's kappa: 0.55, 95% CI: 0.45-0.64). In our inter-rater analysis, the model achieved the highest average agreement (Cohen's kappa: 0.66, 95% CI: 0.57-0.74), outperforming all nine pathologists whose Cohen's kappas ranged from 0.35 to 0.62. Conclusion: Our AI model demonstrates pathologist-level performance for cribriform morphology detection in prostate cancer. This approach could enhance diagnostic reliability, standardise reporting, and improve treatment decisions for prostate cancer patients.
Joint Active RIS Configuration and User Power Control for Localization: A Neuroevolution-Based Approach
Stamatelis, George, Chen, Hui, Wymeersch, Henk, Alexandropoulos, George C.
This paper studies user localization aided by a Reconfigurable Intelligent Surface (RIS). A feedback link from the Base Station (BS) to the user is adopted to enable dynamic power control of the user pilot transmissions in the uplink. A novel multi-agent algorithm for the joint control of the RIS phase configuration and the user transmit power is presented, which is based on a hybrid approach integrating NeuroEvolution (NE) and supervised learning. The proposed scheme requires only single-bit feedback messages for the uplink power control, supports RIS elements with discrete responses, and is numerically shown to outperform fingerprinting, deep reinforcement learning baselines and backpropagation-based position estimators.
On Theoretical Interpretations of Concept-Based In-Context Learning
Tang, Huaze, Peng, Tianren, Huang, Shao-lun
In-Context Learning (ICL) has emerged as an important new paradigm in natural language processing and large language model (LLM) applications. However, the theoretical understanding of the ICL mechanism remains limited. This paper aims to investigate this issue by studying a particular ICL approach, called concept-based ICL (CB-ICL). In particular, we propose theoretical analyses on applying CB-ICL to ICL tasks, which explains why and when the CB-ICL performs well for predicting query labels in prompts with only a few demonstrations. In addition, the proposed theory quantifies the knowledge that can be leveraged by the LLMs to the prompt tasks, and leads to a similarity measure between the prompt demonstrations and the query input, which provides important insights and guidance for model pre-training and prompt engineering in ICL. Moreover, the impact of the prompt demonstration size and the dimension of the LLM embeddings in ICL are also explored based on the proposed theory. Finally, several real-data experiments are conducted to validate the practical usefulness of CB-ICL and the corresponding theory. With the great successes of large language models (LLMs), In-context learning (ICL) has emerged as a new paradigm for natural language processing (NLP) (Brown et al., 2020; Chowdhery et al., 2023; Achiam et al., 2023), where LLMs addresses the requested queries in context prompts with a few demonstrations.
Drivel-ology: Challenging LLMs with Interpreting Nonsense with Depth
Wang, Yang, Xiao, Chenghao, Hsiao, Chia-Yi, Chang, Zi Yan, Chen, Chi-Li, Loakman, Tyler, Lin, Chenghua
We introduce Drivelology, a unique linguistic phenomenon characterised as "nonsense with depth" - utterances that are syntactically coherent yet pragmatically paradoxical, emotionally loaded, or rhetorically subversive. While such expressions may resemble surface-level nonsense, they encode implicit meaning requiring contextual inference, moral reasoning, or emotional interpretation. We find that current large language models (LLMs), despite excelling at many natural language processing (NLP) tasks, consistently fail to grasp the layered semantics of Drivelological text. To investigate this, we construct a benchmark dataset of over 1,200+ meticulously curated and diverse examples across English, Mandarin, Spanish, French, Japanese, and Korean. Each example underwent careful expert review to verify its Drivelological characteristics, involving multiple rounds of discussion and adjudication to address disagreements. Using this dataset, we evaluate a range of LLMs on classification, generation, and reasoning tasks. Our results reveal clear limitations of LLMs: models often confuse Drivelology with shallow nonsense, produce incoherent justifications, or miss implied rhetorical functions altogether. These findings highlight a deep representational gap in LLMs' pragmatic understanding and challenge the assumption that statistical fluency implies cognitive comprehension. We release our dataset and code to facilitate further research in modelling linguistic depth beyond surface-level coherence.
One-Step Flow Policy Mirror Descent
Chen, Tianyi, Ma, Haitong, Li, Na, Wang, Kai, Dai, Bo
Diffusion policies have achieved great success in online reinforcement learning (RL) due to their strong expressive capacity. However, the inference of diffusion policy models relies on a slow iterative sampling process, which limits their responsiveness. To overcome this limitation, we propose Flow Policy Mirror Descent (FPMD), an online RL algorithm that enables 1-step sampling during flow policy inference. Our approach exploits a theoretical connection between the distribution variance and the discretization error of single-step sampling in straight interpolation flow matching models, and requires no extra distillation or consistency training. We present two algorithm variants based on rectified flow policy and MeanFlow policy, respectively. Extensive empirical evaluations on MuJoCo and visual DeepMind Control Suite benchmarks demonstrate that our algorithms show strong performance comparable to diffusion policy baselines while requiring orders of magnitude less computational cost during inference. Diffusion models have established themselves as the state-of-the-art paradigm in generative modeling (Ho et al., 2020; Dhariwal & Nichol, 2021), capable of synthesizing data of unparalleled quality and diversity across various modalities, including images, audio, and video. The success is rooted in a principled, thermodynamically-inspired framework that learns to reverse a gradual noising process (Sohl-Dickstein et al., 2015).
Analysis of Hyperparameter Optimization Effects on Lightweight Deep Models for Real-Time Image Classification
Rakesh, Vineet Kumar, Mazumdar, Soumya, Samanta, Tapas, Pandey, Hemendra Kumar, Das, Amitabha
Lightweight convolutional and transformer-based networks are increasingly preferred for real-time image classification, especially on resource-constrained devices. This study evaluates the impact of hyperparameter optimization on the accuracy and deployment feasibility of seven modern lightweight architectures: ConvNeXt-T, EfficientNetV2-S, MobileNetV3-L, MobileViT v2 (S/XS), RepVGG-A2, and TinyViT-21M, trained on a class-balanced subset of 90,000 images from ImageNet-1K. Under standardized training settings, this paper investigates the influence of learning rate schedules, augmentation, optimizers, and initialization on model performance. Inference benchmarks are performed using an NVIDIA L40s GPU with batch sizes ranging from 1 to 512, capturing latency and throughput in real-time conditions. This work demonstrates that controlled hyperparameter variation significantly alters convergence dynamics in lightweight CNN and transformer backbones, providing insight into stability regions and deployment feasibility in edge artificial intelligence. Our results reveal that tuning alone leads to a top-1 accuracy improvement of 1.5 to 3.5 percent over baselines, and select models (e.g., RepVGG-A2, MobileNetV3-L) deliver latency under 5 milliseconds and over 9,800 frames per second, making them ideal for edge deployment. This work provides reproducible, subset-based insights into lightweight hyperparameter tuning and its role in balancing speed and accuracy. The code and logs may be seen at: https://vineetkumarrakesh.github.io/lcnn-opt
Flows and Diffusions on the Neural Manifold
Saragih, Daniel, Cao, Deyu, Balaji, Tejas
Diffusion and flow-based generative models have achieved remarkable success in domains such as image synthesis, video generation, and natural language modeling. In this work, we extend these advances to weight space learning by leveraging recent techniques to incorporate structural priors derived from optimization dynamics. Central to our approach is modeling the trajectory induced by gradient descent as a trajectory inference problem. We unify several trajectory inference techniques towards matching a gradient flow, providing a theoretical framework for treating optimization paths as inductive bias. We further explore architectural and algorithmic choices, including reward fine-tuning by adjoint matching, the use of autoencoders for latent weight representation, conditioning on task-specific context data, and adopting informative source distributions such as Kaiming uniform. Experiments demonstrate that our method matches or surpasses baselines in generating in-distribution weights, improves initialization for downstream training, and supports fine-tuning to enhance performance. Finally, we illustrate a practical application in safety-critical systems: detecting harmful covariate shifts, where our method outperforms the closest comparable baseline.
Prompt Perturbations Reveal Human-Like Biases in Large Language Model Survey Responses
Rupprecht, Jens, Ahnert, Georg, Strohmaier, Markus
Large Language Models (LLMs) are increasingly used as proxies for human subjects in social science surveys, but their reliability and susceptibility to known human-like response biases, such as central tendency, opinion floating and primacy bias are poorly understood. This work investigates the response robustness of LLMs in normative survey contexts, we test nine LLMs on questions from the World Values Survey (WVS), applying a comprehensive set of ten perturbations to both question phrasing and answer option structure, resulting in over 167,000 simulated survey interviews. In doing so, we not only reveal LLMs' vulnerabilities to perturbations but also show that all tested models exhibit a consistent recency bias, disproportionately favoring the last-presented answer option. While larger models are generally more robust, all models remain sensitive to semantic variations like paraphrasing and to combined perturbations. This underscores the critical importance of prompt design and robustness testing when using LLMs to generate synthetic survey data.
Detecting Token-Level Hallucinations Using Variance Signals: A Reference-Free Approach
- Large Language Models (LLMs) demonstrate impressive generative abilities across a wide range of tasks but continue to suffer from hallucinations --outputs that are fluent yet factually incorrect. This paper introduces a reference-free, token-level hallucination detection framework that identifies unreliable tokens by analyzing variance in log-probabilities across multiple stochastic generations. Unlike traditional methods that depend on external references or sentence-level verification, our approach is model-agnostic, interpretable, and computationally efficient, making it suitable for both real-time and post-hoc analysis. We evaluate the proposed method on three diverse datasets--SQuAD v2 (unanswerable questions), XSum (abstractive summarization), and TriviaQA (open-domain question answering)--using autoregressive models of increasing scale: GPT-Neo 125M, Falcon 1B, and Mistral 7B. Results show that token-level variance strongly correlates with hallucination behavior, revealing clear distinctions in uncertainty across model sizes. The framework maintains accuracy even under limited sampling conditions and introduces minimal computational overhead, supporting its practicality for lightweight deployment. Overall, this work provides a scalable, reproducible, and fine-grained diagnostic tool for detecting hallucinations in LLMs, with potential extensions to multilingual and real-time generation settings. Large language models (LLMs) have transformed natural language processing, powering tasks such as summarization, dialogue generation, and open-ended question answering.
VALID-Mol: a Systematic Framework for Validated LLM-Assisted Molecular Design
Malikussaid, null, Nuha, Hilal Hudan, Kurniawan, Isman
Large Language Models demonstrate substantial promise for advancing scientific discovery, yet their deployment in disciplines demanding factual precision and specialized domain constraints presents significant challenges. Within molecular design for pharmaceutical development, these models can propose innovative molecular modifications but frequently generate chemically infeasible structures. We introduce VALID-Mol, a comprehensive framework that integrates chemical validation with LLM-driven molecular design, achieving an improvement in valid chemical structure generation from 3% to 83%. Our methodology synthesizes systematic prompt optimization, automated chemical verification, and domain-adapted fine-tuning to ensure dependable generation of synthesizable molecules with enhanced properties. Our contribution extends beyond implementation details to provide a transferable methodology for scientifically-constrained LLM applications with measurable reliability enhancements. Computational analyses indicate our framework generates promising synthesis candidates with up to 17-fold predicted improvements in target binding affinity while preserving synthetic feasibility.