Dalian University of Technology
Abstract:Attosecond streaking phase retrieval is essential for resolving electron dynamics on sub-femtosecond time scales yet traditional algorithms rely on iterative minimization and central momentum approximations that degrade accuracy for broadband pulses. In this work phase retrieval is reformulated as a supervised computer-vision problem and four neural architectures are systematically compared. A convolutional network demonstrates strong sensitivity to local streak edges but lacks global context; a vision transformer captures long-range delay-energy correlations at the expense of local inductive bias; a hybrid CNN-ViT model unites local feature extraction and full-graph attention; and a capsule network further enforces spatial pose agreement through dynamic routing. A theoretical analysis introduces local, global and positional sensitivity measures and derives surrogate error bounds that predict the strict ordering $CNN<ViT<Hybrid<Capsule$. Controlled experiments on synthetic streaking spectrograms confirm this hierarchy, with the capsule network achieving the highest retrieval fidelity. Looking forward, embedding the strong-field integral into physics-informed neural networks and exploring photonic hardware implementations promise pathways toward real-time attosecond pulse characterization under demanding experimental conditions.
Abstract:Retrieval-augmented generation (RAG) has achieved great success in information retrieval to assist large models because it builds an external knowledge database. However, it also has many problems: it consumes a lot of memory because of the huge database. When faced with massive streaming data, it is unable to update the established index database in time. To save the memory of building the database and maintain accuracy simultaneously, we proposed a new approach combining a streaming algorithm and k-means cluster with RAG. Our approach applies a streaming algorithm to update the index and reduce memory consumption. Then use the k-means algorithm to cluster documents with high similarities together, the query time will be shortened by doing this. We conducted comparative experiments on four methods, and the results show that RAG with streaming algorithm and k-means cluster performs well in accuracy and memory. For massive streaming data, we find that our method behaves better than traditional RAG