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Pengfei Kang

Publications and source records attributed to Pengfei Kang.

3 recordsLinked to original sources

AliyunConsoleAgent: Training Web Agents in Real-World Cloud Environments via Distillation and Reinforcement Learning

We present AliyunConsoleAgent, a web agent framework for automated documentation verification in real-world cloud consoles. Major cloud platforms encompass hundreds of products with rapid feature iteration, causing console UIs to frequently diverge from their corresponding documentation. Verifying that documented procedures accurately reflect the current console and can be executed end-to-end demands an estimated 4 million recurring inspections annually, yet manual coverage remains below 1%. While agent systems built on frontier proprietary models achieve high success rates, their prohibitive cost and data privacy constraints preclude large-scale deployment. We propose a two-stage training paradigm: supervised fine-tuning (SFT) on distilled frontier-model trajectories, followed by reinforcement learning using Group Relative Policy Optimization (GRPO) and a dual-channel outcome reward model in real cloud environments. To support large-scale RL training, we construct a high-determinism rollout system featuring Terraform-based resource pre-provisioning and LLM-driven on-demand provisioning, which effectively isolates environment noise from the training signal. We further introduce a rule-based reward evaluation protocol grounded in backend audit logs, providing objective, reward-hacking-resistant outcome judgment. Our model evolves from mechanical instruction following to autonomous decision-making with cloud console and product-specific understanding. Experiments on a challenging 278-task benchmark where the best frontier model achieves only 65.34% demonstrate that AliyunConsoleAgent-32B achieves a 63.52% mean success rate -- a 20.24 percentage-point improvement over the base model, narrowing the gap to the best frontier proprietary model to 1.82 pp (bootstrap 95% CI [-1.27, 7.39]) -- at 92% lower inference cost.

cs.AI

Anomalous size effects with fixed criticality in bistable flexible mechanical metamaterials

When the structure deformation is dominated by the low-energy deformation mode, the structure hardens with the increase in the size (number of units) at small sizes. This anomalous behavior will eventually disappear with the decay length of the finite structure converging to a size-independent characteristic quantity, but the specific critical point at which the anomalous behavior disappears still cannot be accurately and concisely described. Here, under two steady states of the bistable chain, we observed anomalous size effects with constant and oscillating criticality (the proportion of inhomogeneous deformation), two criticalities exactly separate the increasing and decreasing intervals of stiffness variation. They are interrelated due to the implied symmetries between the two steady states. On the other hand, they are distinguished because of the opposite superposition modes under the two steady states. Specifically, the constant criticality corresponds to the anomalous size effect achieved by the competition mechanism, while the oscillating criticality reveals an anomalous size effect achieved by the new mechanism (cancellation mechanism). In the anomalous size effect achieved by the cancellation mechanism, the singular characteristics generated by the completely cancelled deformation make it very robust. This robustness reflects in that the anomalous effect is no longer limited to linear small deformation, but it can still be observed stably in nonlinear large deformation. Our study reinterprets the anomalous size effect at a quantitative level, and the proposed cancellation mechanism expands the possible application range of this anomalous effect.

physics.app-ph

Elastic fractal higher-order topological states

Fractal is an intriguing geometry with self-similarity and non-integer dimensions, the elastic-wave topological phase based on fractal structures has not been revealed up to now. In this work, elastic-wave higher-order topological states in fractal structures are investigated. Elastic real-space quantized quadrupole moment is calculated and used to characterize the topology of elastic fractal metamaterials, and formation conditions of topological phase transitions in elastic fractal systems are revealed. The topological edge and corner states of elastic waves in fractal structures are realized theoretically and experimentally. It is found that different from the acoustic fractal system, the topological outer and inner edge states can emerge separately in elastic fractal systems, which is important for the integrated sensing and particle manipulation in microfluidics. Besides, the results show that the robustness of the topological corner states in rhombus fractal structures is obviously stronger than that in Sierpinski fractal structures, and the physical mechanism is clarified. Compared with traditional elastic-wave topological insulators based on periodic structures, the richness of topological states in elastic fractal structures is much higher (for the Sierpinski fractal structure, the number of topological states is 156, much greater than that of the periodic structure (only 28)), which is vital in integrated sensing and energy-location applications. The topological phenomena of elastic fractal systems revealed in this work, provides an unprecedented way of controlling elastic waves, enriches the topological physics of elastic systems and breaks the limitation of that relying on periodic elastic structures. The results have great application prospects in high-Q resonators, high-resolution elastic-wave energy locations, energy harvester, and high-sensitivity sensors.

physics.app-ph