To solve the inaccuracy problem caused by the two existing methods (averageend-area method and prismoidal method) used for the calculation of roadway earthwork volume, thispaper puts forward a new concept of the 3-dim...To solve the inaccuracy problem caused by the two existing methods (averageend-area method and prismoidal method) used for the calculation of roadway earthwork volume, thispaper puts forward a new concept of the 3-dimensional algorithm that takes all the roadway geometricdesign procedures as a kind of geometrical operation between the ground model (original terrainmodel) and the roadway model (designed model) under certain constraints, and then presents acomplete 3-dimensional algorithm of roadway earthwork volume as well as its executable computerprogram. The algorithm benefits from the re-triangulation technique of constrained delaunaytriangulation (CDT), which can yield a true volume value theoretically. Through a number ofpractical testscovering varied intervals between adjacent cross sections, it is proven to possess ahigher accuracy compared with that of traditional methods. All the work involved in this paperindicates that the 3-dimensional calculation of roadway earthwork volumeis feasible, more accurateand should have further application in practice.展开更多
Three-dimensional(3D) modeling of medical images is a critical part of surgical simulation. In this paper, we focus on the magnetic resonance(MR) images denoising for brain modeling reconstruction, and exploit a pract...Three-dimensional(3D) modeling of medical images is a critical part of surgical simulation. In this paper, we focus on the magnetic resonance(MR) images denoising for brain modeling reconstruction, and exploit a practical solution. We attempt to remove the noise existing in the MR imaging signal and preserve the image characteristics. A wavelet-based adaptive curve shrinkage function is presented in spherical coordinates system. The comparative experiments show that the denoising method can preserve better image details and enhance the coefficients of contours. Using these denoised images, the brain 3D visualization is given through surface triangle mesh model, which demonstrates the effectiveness of the proposed method.展开更多
文摘To solve the inaccuracy problem caused by the two existing methods (averageend-area method and prismoidal method) used for the calculation of roadway earthwork volume, thispaper puts forward a new concept of the 3-dimensional algorithm that takes all the roadway geometricdesign procedures as a kind of geometrical operation between the ground model (original terrainmodel) and the roadway model (designed model) under certain constraints, and then presents acomplete 3-dimensional algorithm of roadway earthwork volume as well as its executable computerprogram. The algorithm benefits from the re-triangulation technique of constrained delaunaytriangulation (CDT), which can yield a true volume value theoretically. Through a number ofpractical testscovering varied intervals between adjacent cross sections, it is proven to possess ahigher accuracy compared with that of traditional methods. All the work involved in this paperindicates that the 3-dimensional calculation of roadway earthwork volumeis feasible, more accurateand should have further application in practice.
基金supported by the National Natural Science Foundation of China(No.61202169)the Tianjin Key Natural Science Foundation(No.13JCZDJC34600)+1 种基金the China Scholarship Council(CSC)Foundation(No.201308120010)the Training Plan of Tianjin University Innovation Team(No.TD12-5016)
文摘Three-dimensional(3D) modeling of medical images is a critical part of surgical simulation. In this paper, we focus on the magnetic resonance(MR) images denoising for brain modeling reconstruction, and exploit a practical solution. We attempt to remove the noise existing in the MR imaging signal and preserve the image characteristics. A wavelet-based adaptive curve shrinkage function is presented in spherical coordinates system. The comparative experiments show that the denoising method can preserve better image details and enhance the coefficients of contours. Using these denoised images, the brain 3D visualization is given through surface triangle mesh model, which demonstrates the effectiveness of the proposed method.
