Communications: Overviews
AI summaries of Tripadvisor hotel reviews downplay serious complaints, investigation finds
Travel, said users should'scroll past these summaries and look at guest reviews'. Travel, said users should'scroll past these summaries and look at guest reviews'. AI-generated overview found to gloss over allegations of sexual harassment and describes hotel being sued over hygiene as'spotless' A hotel being sued for mass food poisonings was described as "spotless" and a resort where guests complained of sexual harassment by staff was praised for "friendly" service by an AI intended to summarise millions of Tripadvisor reviews. The overviews of customer feedback downplayed serious complaints, ranging from the stench of mould to a lack of mains water, according to an investigation by the consumer campaign organisation Which? The AI-generated reviews appear on the travel website's hotel webpages to help holidaymakers decide where to book.
IPAD Inverse Prompt for and Interpretable LLM Generated Text Detector
Large Language Models (LLMs) have attained human-level fluency in text generation, which complicates the distinguishing between human-written and LLMgenerated texts. This increases the risk of misuse and highlights the need for reliable detectors. Yet, existing detectors exhibit poor robustness on out-of-distribution (OOD) data and attacked data, which is critical for real-world scenarios. Also, they struggle to provide interpretable evidence to support their decisions, thus undermining the reliability. In light of these challenges, we propose IPAD (Inverse Prompt for AIDetection), a novel framework consisting of a Prompt Inverter that identifies predicted prompts that could have generated the input text, and two Distinguishers that examine the probability that the input texts align with the predicted prompts. Empirical evaluations demonstrate that IPAD outperforms the strongest baselines by 9.05% (Average Recall) on in-distribution data, 12.93% (AUROC) on out-of-distribution data, and 5.48% (AUROC) on attacked data. IPAD also performs robustly on structured datasets. Furthermore, an interpretability assessment is conducted to illustrate that IPAD enhances the AI detection trustworthiness by allowing users to directly examine the decision-making evidence, which provides interpretable support for its state-of-the-art detection results.
GUI-Rise: Structured Reasoning and History Summarization for GUINavigation
While Multimodal Large Language Models (MLLMs) have advanced GUI navigation agents, current approaches face limitations in cross-domain generalization and effective history utilization. We present a reasoning-enhanced framework that systematically integrates structured reasoning, action prediction, and history summarization. The structured reasoning component generates coherent Chain-ofThought analyses combining progress estimation and decision reasoning, which inform both immediate action predictions and compact history summaries for future steps. Based on this framework, we train a GUI agent, GUI-Rise, through supervised fine-tuning on pseudo-labeled trajectories and reinforcement learning with Group Relative Policy Optimization (GRPO). This framework employs specialized rewards, including a history-aware objective, directly linking summary quality to subsequent action performance. Comprehensive evaluations on standard benchmarks demonstrate state-of-the-art results under identical training data conditions, with particularly strong performance in out-of-domain scenarios. These findings validate our framework's ability to maintain robust reasoning and generalization across diverse GUI navigation tasks. Code is available at https://leon022.github.io/GUI-Rise.
Effective Policy Learning for Multi-Agent Online Coordination Beyond Submodular Objectives
The first one, MA-SPL, not only can achieve the optimal (1 ce)-approximation guarantee for the MA-OC problem with submodular objectives but also can handle the unexplored α-weakly DR-submodular and (γ,β)-weakly submodular scenarios, where c is the curvature of the investigated submodular functions, α denotes the diminishing-return(DR) ratio and the tuple (γ,β) represents the submodularity ratios. Subsequently, in order to reduce the reliance on the unknown parameters α,γ,β inherent in the MA-SPLalgorithm, we further introduce the second online algorithm named MA-MPL. This MA-MPL algorithm is entirely parameter-free and simultaneously can maintain the same approximation ratio as the first MA-SPL algorithm. The core of our MA-SPL and MA-MPL algorithms is a novel continuous-relaxation technique termed as policybased continuous extension. Compared with the well-established multi-linear extension, a notable advantage of this new policy-based continuous extension is its ability to provide a lossless rounding scheme for any set function, thereby enabling us to tackle the challenging weakly submodular objectives. Finally, extensive simulations are conducted to validate the effectiveness of our proposed algorithms.
4KAgent: Agentic Any Image to 4KSuper-Resolution
We present 4KAgent, a unified agentic super-resolution generalist system designed to universally upscale any image to 4K resolution (and even higher, if applied iteratively). Our system can transform images from extremely low resolutions with severe degradations, for example, highly distorted inputs at 256 256, into crystal-clear, photorealistic 4K outputs.
Deep Continuous-Time State-Space Models for Marked Event Sequences
Marked temporal point processes (MTPPs) model sequences of events occurring at irregular time intervals, with wide-ranging applications in fields such as healthcare, finance and social networks. We propose the state-space point process (S2P2) model, a novel and performant model that leverages techniques derived for modern deep state-space models (SSMs) to overcome limitations of existing MTPP models, while simultaneously imbuing strong inductive biases for continuous-time event sequences that other discrete sequence models (i.e., RNNs, transformers) do not capture. Inspired by the classical linear Hawkes processes, we propose an architecture that interleaves stochastic jump differential equations with nonlinearities to create a highly expressive intensity-based MTPP model, without the need for restrictive parametric assumptions for the intensity. Our approach enables efficient training and inference with a parallel scan, bringing linear complexity and sublinear scaling while retaining expressivity to MTPPs. Empirically, S2P2 achieves state-of-the-art predictive likelihoods across eight real-world datasets, delivering an average improvement of 33% over the best existing approaches.
Tree of Preferences for Diversified Recommendation
Diversified recommendation has attracted increasing attention from both researchers and practitioners, which can effectively address the homogeneity of recommended items. Existing approaches predominantly aim to infer the diversity of user preferences from observed user feedback. Nonetheless, due to inherent data biases, the observed data may not fully reflect user interests, where underexplored preferences can be overwhelmed or remain unmanifested. Failing to capture these preferences can lead to suboptimal diversity in recommendations. To fill this gap, this work aims to study diversified recommendation from a data-bias perspective.
Adaptive Frontier Exploration on Graphs with Applications to Network-Based Disease Testing
We study a sequential decision-making problem on a n-node graph G where each node has an unknown label from a finite set Ω, drawn from a joint distribution P that is Markov with respect to G. At each step, selecting a node reveals its label and yields a label-dependent reward. The goal is to adaptively choose nodes to maximize expected accumulated discounted rewards. We impose a frontier exploration constraint, where actions are limited to neighbors of previously selected nodes, reflecting practical constraints in settings such as contact tracing and robotic exploration. We design a Gittins index-based policy that applies to general graphs and is provably optimal when G is a forest.