Boundary representation (B-rep) of geometric models is a fundamental format in Computer-Aided Design (CAD). However, automatically generating valid and high-quality B-rep models remains challenging due to the complex interdependence between the topology and geometry of the models. Existing methods tend to prioritize geometric representation while giving insufficient attention to topological constraints, making it difficult to maintain structural validity and geometric accuracy. In this paper, we propose DTGBrepGen, a novel topology-geometry decoupled framework for B-rep generation that explicitly addresses both aspects. Our approach first generates valid topological structures through a two-stage process that independently models edge-face and edge-vertex adjacency relationships. Subsequently, we employ Transformer-based diffusion models for sequential geometry generation, progressively generating vertex coordinates, followed by edge geometries and face geometries which are represented as B-splines. Extensive experiments on diverse CAD datasets show that DTGBrepGen significantly outperforms existing methods in both topological validity and geometric accuracy, achieving higher validity rates and producing more diverse and realistic B-reps. Our code is publicly available at https://github.com/jinli99/DTGBrepGen.

With the explosive growth of video data, efficient video analysis technology has garnered widespread attention. Existing online methods train proxy neural networks upon query arrival and use these networks to scan the entire dataset, guiding the invocation of the expensive deep neural network. While index-based methods advance this process to the index-building stage, significantly reducing the time overhead of video queries. However, the data to query often presents a long-tail distribution, and different types of queries are sensitive to different parts of the distribution. Since the index-based methods cannot predict the queries, they can only provide ad-hoc proxy score generating strategies. This paper proposes a query-aware video analysis framework, QaVA, to improve query performance further. QaVA retains the time-consuming, query-independent semantic extraction process during the index-building stage and employs a tunable lightweight adapter network to accurately and quickly focus on the data parts most relevant to the query after it arrives. Meanwhile, QaVA can automatically tune the training strategy of the adapter network by analyzing the data access pattern of historical queries, thus meeting the needs of general users. Experimental results demonstrate that QaVA can significantly reduce the cost of various queries across multiple datasets, and can speed up query processing by up to$9.2\times$compared to the most advanced index-based method. Our code is available: https://github.com/InkosiZhong/QaVA.