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Reasonable urban commercial planning must clarify the location and scope of urban commercial districts (UCDs). However, existing studies typically detect spurious UCDs owing to the bias in a single data source while ignoring the continuity and ambiguity of commercial district boundaries. Therefore, in this study, we designed a two-stage approach for detecting UCDs. First, points of interest and population heat data were fused through hotspot and overlay analyses to detect core commercial areas. The boundaries of the UCDs were then identified by considering adjacent blocks using adjusted cosine similarity and region-growing algorithms. Finally, an experiment was conducted in Xiamen, revealing concentrated businesses on Xiamen Island and sparse businesses outside Xiamen Island. An experimental comparison with other strategies confirmed the improved modeling ability of this approach for the edge ambiguity of UCDs. This framework provides tools for urban commercial planning and helps recognize urban commercial patterns in a timely manner. [ABSTRACT FROM AUTHOR]

Filament winding is a technique that precisely places continuous fibers along a preset path on a rotating mandrel. However, traditional 2D winding paths based on the original mandrel surface ignore the effect of thickness stacking on doffing points. To physically simulate the build-up of tows on the mandrel, a novel numerical method, including the mesh-based directional projection (MDP) and normal adaptive convex helix (NACH) algorithms, is proposed. The MDP algorithm is employed to sort out tow overlaps in the thickness direction, and is 200 times more efficient than the existing algorithms, such as the backward search algorithm. Subsequently, the "cliffs" generated in the overlap removal process are smoothed by the NACH algorithm. Furthermore, the advantages of these two algorithms in terms of efficiency, reliability, and universality are discussed in detail. In summary, a method for developing a physical-based 3D path and ever-updating workpiece contour of pressure vessels is proposed, which serves as an essential reference for high-precision winding and workpiece shape optimization. [ABSTRACT FROM AUTHOR]

A novel filament winding virtual tool is proposed to develop the 3D winding paths on the workpiece contour in real-time. The semi-geodesic and constant-wall-thickness (CWT) trajectories are used to generate the centerline of the 3D path. A tow overlaps processing method and the outer-contour expanding algorithm (OEA) are developed to eliminate the tow interference. The convex helix algorithm (CHA) is proposed to smooth the cliff generated in the interference elimination. The OEA and CHA algorithms are considered due to their high computational efficiency as compared to the traditional algorithms, such as the Backward Search algorithm (BSA) and l -BFGS Algorithm. The prospective virtual tool develops a stable winding path, and experimental results have shown that the 3D path does have advantages over the traditional 2D path in terms of high preservation of the tow path and the prevention of the tow slippage. [ABSTRACT FROM AUTHOR]