LGSep 16, 2023
Improve Deep Forest with Learnable Layerwise Augmentation Policy ScheduleHongyu Zhu, Sichu Liang, Wentao Hu et al.
As a modern ensemble technique, Deep Forest (DF) employs a cascading structure to construct deep models, providing stronger representational power compared to traditional decision forests. However, its greedy multi-layer learning procedure is prone to overfitting, limiting model effectiveness and generalizability. This paper presents an optimized Deep Forest, featuring learnable, layerwise data augmentation policy schedules. Specifically, We introduce the Cut Mix for Tabular data (CMT) augmentation technique to mitigate overfitting and develop a population-based search algorithm to tailor augmentation intensity for each layer. Additionally, we propose to incorporate outputs from intermediate layers into a checkpoint ensemble for more stable performance. Experimental results show that our method sets new state-of-the-art (SOTA) benchmarks in various tabular classification tasks, outperforming shallow tree ensembles, deep forests, deep neural network, and AutoML competitors. The learned policies also transfer effectively to Deep Forest variants, underscoring its potential for enhancing non-differentiable deep learning modules in tabular signal processing.
CRApr 17
DEMUX: Boundary-Aware Multi-Scale Traffic Demixing for Multi-Tab Website FingerprintingYali Yuan, Yaosheng Liu, Qianqi Niu et al.
Website fingerprinting (WF) attacks infer the websites visited by users from encrypted traffic in anonymous networks such as Tor. Existing deep learning methods achieve high accuracy under the single-tab assumption but degrade substantially when users open multiple tabs concurrently, producing interleaved traffic that transforms WF into an implicit demixing problem. We identify three structural requirements for effective multi-tab demixing, namely signal integrity at segment boundaries, multi-scale local modeling, and relative temporal association of dispersed fragments, and show that no prior method satisfies all three simultaneously. We propose DEMUX, a designed framework that addresses these requirements through three tightly coupled components. A Boundary Preserving Aggregation Module employs overlapping window partitioning with joint packet-level and burst-level feature extraction. A Multi-Scale Parallel CNN captures heterogeneous temporal patterns via parallel branches. A two-stage Transformer encoder with Rotary Positional Embedding enables robust cross-window fragment association. The Boundary Preserving Aggregation Module additionally serves as a plug-and-play preprocessor that consistently improves existing baselines without architectural modification. Extensive experiments across closed-world, open-world, defense-augmented, dynamic-tab, and cross-configuration settings demonstrate that DEMUX achieves state-of-the-art performance. In the challenging closed-world 5-tab setting, DEMUX attains a P@5 of 0.943 and MAP@5 of 0.961, outperforming the strongest baseline by 9.2 and 6.2 percentage points respectively, confirming its strong robustness in complex multi-tab demixing scenarios.
CRJun 25, 2025
Attack Smarter: Attention-Driven Fine-Grained Webpage Fingerprinting AttacksYali Yuan, Weiyi Zou, Guang Cheng
Website Fingerprinting (WF) attacks aim to infer which websites a user is visiting by analyzing traffic patterns, thereby compromising user anonymity. Although this technique has been demonstrated to be effective in controlled experimental environments, it remains largely limited to small-scale scenarios, typically restricted to recognizing website homepages. In practical settings, however, users frequently access multiple subpages in rapid succession, often before previous content fully loads. WebPage Fingerprinting (WPF) generalizes the WF framework to large-scale environments by modeling subpages of the same site as distinct classes. These pages often share similar page elements, resulting in lower inter-class variance in traffic features. Furthermore, we consider multi-tab browsing scenarios, in which a single trace encompasses multiple categories of webpages. This leads to overlapping traffic segments, and similar features may appear in different positions within the traffic, thereby increasing the difficulty of classification. To address these challenges, we propose an attention-driven fine-grained WPF attack, named ADWPF. Specifically, during the training phase, we apply targeted augmentation to salient regions of the traffic based on attention maps, including attention cropping and attention masking. ADWPF then extracts low-dimensional features from both the original and augmented traffic and applies self-attention modules to capture the global contextual patterns of the trace. Finally, to handle the multi-tab scenario, we employ the residual attention to generate class-specific representations of webpages occurring at different temporal positions. Extensive experiments demonstrate that the proposed method consistently surpasses state-of-the-art baselines across datasets of different scales.
NIApr 2, 2020
RACE: Reinforced Cooperative Autonomous Vehicle Collision AvoidancEYali Yuan, Robert Tasik, Sripriya Srikant Adhatarao et al.
With the rapid development of autonomous driving, collision avoidance has attracted attention from both academia and industry. Many collision avoidance strategies have emerged in recent years, but the dynamic and complex nature of driving environment poses a challenge to develop robust collision avoidance algorithms. Therefore, in this paper, we propose a decentralized framework named RACE: Reinforced Cooperative Autonomous Vehicle Collision AvoidancE. Leveraging a hierarchical architecture we develop an algorithm named Co-DDPG to efficiently train autonomous vehicles. Through a security abiding channel, the autonomous vehicles distribute their driving policies. We use the relative distances obtained by the opponent sensors to build the VANET instead of locations, which ensures the vehicle's location privacy. With a leader-follower architecture and parameter distribution, RACE accelerates the learning of optimal policies and efficiently utilizes the remaining resources. We implement the RACE framework in the widely used TORCS simulator and conduct various experiments to measure the performance of RACE. Evaluations show that RACE quickly learns optimal driving policies and effectively avoids collisions. Moreover, RACE also scales smoothly with varying number of participating vehicles. We further compared RACE with existing autonomous driving systems and show that RACE outperforms them by experiencing 65% less collisions in the training process and exhibits improved performance under varying vehicle density.